X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/17c761988f30054827a9951761d93ffeeaad0cb7..3f77bd134b64c532748b83c3931df07058268b5e:/src/src/smtp_in.c diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c index 5d241d960..70e4b95df 100644 --- a/src/src/smtp_in.c +++ b/src/src/smtp_in.c @@ -2,13 +2,16 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2009 */ +/* Copyright (c) The Exim Maintainers 2020 - 2023 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ /* See the file NOTICE for conditions of use and distribution. */ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* Functions for handling an incoming SMTP call. */ #include "exim.h" +#include /* Initialize for TCP wrappers if so configured. It appears that the macro @@ -36,18 +39,18 @@ uschar *tcp_wrappers_name; /* Size of buffer for reading SMTP commands. We used to use 512, as defined by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP commands that accept arguments, and this in particular applies to AUTH, where -the data can be quite long. More recently this value was 2048 in Exim; +the data can be quite long. More recently this value was 2048 in Exim; however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients -such as Thunderbird will send an AUTH with an initial-response for GSSAPI. -The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and +such as Thunderbird will send an AUTH with an initial-response for GSSAPI. +The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and we need room to handle large base64-encoded AUTHs for GSSAPI. */ -#define smtp_cmd_buffer_size 16384 +#define SMTP_CMD_BUFFER_SIZE 16384 /* Size of buffer for reading SMTP incoming packets */ -#define in_buffer_size 8192 +#define IN_BUFFER_SIZE 8192 /* Structure for SMTP command list */ @@ -71,6 +74,10 @@ enum { VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */ ETRN_CMD, /* This by analogy with TURN from the RFC */ STARTTLS_CMD, /* Required by the STARTTLS RFC */ + TLS_AUTH_CMD, /* auto-command at start of SSL */ +#ifdef EXPERIMENTAL_XCLIENT + XCLIENT_CMD, /* per xlexkiro implementation */ +#endif /* This is a dummy to identify the non-sync commands when pipelining */ @@ -84,6 +91,19 @@ enum { NON_SYNC_CMD_NON_PIPELINING, + /* RFC3030 section 2: "After all MAIL and RCPT responses are collected and + processed the message is sent using a series of BDAT commands" + implies that BDAT should be synchronized. However, we see Google, at least, + sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for + processing of the RCPT response(s). We shall do the same, and not require + synch for BDAT. Worse, as the chunk may (very likely will) follow the + command-header in the same packet we cannot do the usual "is there any + follow-on data after the command line" even for non-pipeline mode. + So we'll need an explicit check after reading the expected chunk amount + when non-pipe, before sending the ACK. */ + + BDAT_CMD, + /* I have been unable to find a statement about the use of pipelining with AUTH, so to be on the safe side it is here, though I kind of feel it should be up there with the synchronized commands. */ @@ -94,6 +114,10 @@ enum { QUIT_CMD, HELP_CMD, +#ifdef SUPPORT_PROXY + PROXY_FAIL_IGNORE_CMD, +#endif + /* These are specials that don't correspond to actual commands */ EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD, @@ -112,22 +136,35 @@ to the circular buffer that holds a list of the last n received. */ * Local static variables * *************************************************/ -static auth_instance *authenticated_by; -static BOOL auth_advertised; -#ifdef SUPPORT_TLS -static BOOL tls_advertised; +static struct { + BOOL auth_advertised :1; +#ifndef DISABLE_TLS + BOOL tls_advertised :1; +#endif + BOOL dsn_advertised :1; + BOOL esmtp :1; + BOOL helo_verify_required :1; + BOOL helo_verify :1; + BOOL helo_seen :1; + BOOL helo_accept_junk :1; +#ifndef DISABLE_PIPE_CONNECT + BOOL pipe_connect_acceptable :1; +#endif + BOOL rcpt_smtp_response_same :1; + BOOL rcpt_in_progress :1; + BOOL smtp_exit_function_called :1; +#ifdef SUPPORT_I18N + BOOL smtputf8_advertised :1; #endif -static BOOL esmtp; -static BOOL helo_required = FALSE; -static BOOL helo_verify = FALSE; -static BOOL helo_seen; -static BOOL helo_accept_junk; -static BOOL count_nonmail; -static BOOL pipelining_advertised; -static BOOL rcpt_smtp_response_same; -static BOOL rcpt_in_progress; +} fl = { + .helo_verify_required = FALSE, + .helo_verify = FALSE, + .smtp_exit_function_called = FALSE, +}; + +static auth_instance *authenticated_by; +static int count_nonmail; static int nonmail_command_count; -static BOOL smtp_exit_function_called = 0; static int synprot_error_count; static int unknown_command_count; static int sync_cmd_limit; @@ -150,22 +187,44 @@ AUTH is already forbidden. After a TLS session is started, AUTH's flag is again forced TRUE, to allow for the re-authentication that can happen at that point. QUIT is also "falsely" labelled as a mail command so that it doesn't up the -count of non-mail commands and possibly provoke an error. */ +count of non-mail commands and possibly provoke an error. -static smtp_cmd_list cmd_list[] = { - { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */ - { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE }, - { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE }, - { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE }, - #ifdef SUPPORT_TLS - { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE }, - #endif +tls_auth is a pseudo-command, never expected in input. It is activated +on TLS startup and looks for a tls authenticator. */ + +enum { + CL_RSET = 0, + CL_HELO, + CL_EHLO, + CL_AUTH, +#ifndef DISABLE_TLS + CL_STLS, + CL_TLAU, +#endif +#ifdef EXPERIMENTAL_XCLIENT + CL_XCLI, +#endif +}; -/* If you change anything above here, also fix the definitions below. */ +static smtp_cmd_list cmd_list[] = { + /* name len cmd has_arg is_mail_cmd */ + + [CL_RSET] = { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */ + [CL_HELO] = { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE }, + [CL_EHLO] = { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE }, + [CL_AUTH] = { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE }, +#ifndef DISABLE_TLS + [CL_STLS] = { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE }, + [CL_TLAU] = { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE }, +#endif +#ifdef EXPERIMENTAL_XCLIENT + [CL_XCLI] = { "xclient", sizeof("xclient")-1, XCLIENT_CMD, TRUE, FALSE }, +#endif { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE }, { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE }, { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE }, + { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE }, { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE }, { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE }, { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE }, @@ -174,25 +233,32 @@ static smtp_cmd_list cmd_list[] = { { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE } }; -static smtp_cmd_list *cmd_list_end = - cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list); - -#define CMD_LIST_RSET 0 -#define CMD_LIST_HELO 1 -#define CMD_LIST_EHLO 2 -#define CMD_LIST_AUTH 3 -#define CMD_LIST_STARTTLS 4 +/* This list of names is used for performing the smtp_no_mail logging action. */ -/* This list of names is used for performing the smtp_no_mail logging action. -It must be kept in step with the SCH_xxx enumerations. */ - -static uschar *smtp_names[] = +uschar * smtp_names[] = { - US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO", - US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS", - US"VRFY" }; + [SCH_NONE] = US"NONE", + [SCH_AUTH] = US"AUTH", + [SCH_DATA] = US"DATA", + [SCH_BDAT] = US"BDAT", + [SCH_EHLO] = US"EHLO", + [SCH_ETRN] = US"ETRN", + [SCH_EXPN] = US"EXPN", + [SCH_HELO] = US"HELO", + [SCH_HELP] = US"HELP", + [SCH_MAIL] = US"MAIL", + [SCH_NOOP] = US"NOOP", + [SCH_QUIT] = US"QUIT", + [SCH_RCPT] = US"RCPT", + [SCH_RSET] = US"RSET", + [SCH_STARTTLS] = US"STARTTLS", + [SCH_VRFY] = US"VRFY", +#ifdef EXPERIMENTAL_XCLIENT + [SCH_XCLIENT] = US"XCLIENT", +#endif + }; -static uschar *protocols[] = { +static uschar *protocols_local[] = { US"local-smtp", /* HELO */ US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */ US"local-esmtp", /* EHLO */ @@ -200,12 +266,53 @@ static uschar *protocols[] = { US"local-esmtpa", /* EHLO->AUTH */ US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */ }; +static uschar *protocols[] = { + US"smtp", /* HELO */ + US"smtps", /* The rare case EHLO->STARTTLS->HELO */ + US"esmtp", /* EHLO */ + US"esmtps", /* EHLO->STARTTLS->EHLO */ + US"esmtpa", /* EHLO->AUTH */ + US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */ + }; #define pnormal 0 #define pextend 2 #define pcrpted 1 /* added to pextend or pnormal */ #define pauthed 2 /* added to pextend */ -#define pnlocal 6 /* offset to remove "local" */ + +/* Sanity check and validate optional args to MAIL FROM: envelope */ +enum { + ENV_MAIL_OPT_NULL, + ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH, +#ifndef DISABLE_PRDR + ENV_MAIL_OPT_PRDR, +#endif + ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID, +#ifdef SUPPORT_I18N + ENV_MAIL_OPT_UTF8, +#endif + }; +typedef struct { + uschar * name; /* option requested during MAIL cmd */ + int value; /* enum type */ + BOOL need_value; /* TRUE requires value (name=value pair format) + FALSE is a singleton */ + } env_mail_type_t; +static env_mail_type_t env_mail_type_list[] = { + { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE }, + { US"BODY", ENV_MAIL_OPT_BODY, TRUE }, + { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE }, +#ifndef DISABLE_PRDR + { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE }, +#endif + { US"RET", ENV_MAIL_OPT_RET, TRUE }, + { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE }, +#ifdef SUPPORT_I18N + { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */ +#endif + /* keep this the last entry */ + { US"NULL", ENV_MAIL_OPT_NULL, FALSE }, + }; /* When reading SMTP from a remote host, we have to use our own versions of the C input-reading functions, in order to be able to flush the SMTP output only @@ -231,60 +338,235 @@ static int smtp_had_eof; static int smtp_had_error; +/* forward declarations */ +static int smtp_read_command(BOOL check_sync, unsigned buffer_lim); +static int synprot_error(int type, int code, uschar *data, uschar *errmess); +static void smtp_quit_handler(uschar **, uschar **); +static void smtp_rset_handler(void); + /************************************************* -* SMTP version of getc() * +* Log incomplete transactions * *************************************************/ -/* This gets the next byte from the SMTP input buffer. If the buffer is empty, -it flushes the output, and refills the buffer, with a timeout. The signal -handler is set appropriately by the calling function. This function is not used -after a connection has negotated itself into an TLS/SSL state. +/* This function is called after a transaction has been aborted by RSET, QUIT, +connection drops or other errors. It logs the envelope information received +so far in order to preserve address verification attempts. -Arguments: none -Returns: the next character or EOF +Argument: string to indicate what aborted the transaction +Returns: nothing */ -int -smtp_getc(void) +static void +incomplete_transaction_log(uschar * what) +{ +if (!sender_address /* No transaction in progress */ + || !LOGGING(smtp_incomplete_transaction)) + return; + +/* Build list of recipients for logging */ + +if (recipients_count > 0) + { + raw_recipients = store_get(recipients_count * sizeof(uschar *), GET_UNTAINTED); + for (int i = 0; i < recipients_count; i++) + raw_recipients[i] = recipients_list[i].address; + raw_recipients_count = recipients_count; + } + +log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS, + "%s incomplete transaction (%s)", host_and_ident(TRUE), what); +} + + + +static void +log_close_event(const uschar * reason) +{ +log_write(L_smtp_connection, LOG_MAIN, "%s D=%s closed %s", + smtp_get_connection_info(), string_timesince(&smtp_connection_start), reason); +} + + +void +smtp_command_timeout_exit(void) +{ +log_write(L_lost_incoming_connection, + LOG_MAIN, "SMTP command timeout on%s connection from %s D=%s", + tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE), + string_timesince(&smtp_connection_start)); +if (smtp_batched_input) + moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */ +smtp_notquit_exit(US"command-timeout", US"421", + US"%s: SMTP command timeout - closing connection", + smtp_active_hostname); +exim_exit(EXIT_FAILURE); +} + +void +smtp_command_sigterm_exit(void) +{ +log_close_event(US"after SIGTERM"); +if (smtp_batched_input) + moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */ +smtp_notquit_exit(US"signal-exit", US"421", + US"%s: Service not available - closing connection", smtp_active_hostname); +exim_exit(EXIT_FAILURE); +} + +void +smtp_data_timeout_exit(void) +{ +log_write(L_lost_incoming_connection, LOG_MAIN, + "SMTP data timeout (message abandoned) on connection from %s F=<%s> D=%s", + sender_fullhost ? sender_fullhost : US"local process", sender_address, + string_timesince(&smtp_connection_start)); +receive_bomb_out(US"data-timeout", US"SMTP incoming data timeout"); +/* Does not return */ +} + +void +smtp_data_sigint_exit(void) +{ +log_close_event(had_data_sigint == SIGTERM ? US"SIGTERM":US"SIGINT"); +receive_bomb_out(US"signal-exit", + US"Service not available - SIGTERM or SIGINT received"); +/* Does not return */ +} + + +/******************************************************************************/ +/* SMTP input buffer handling. Most of these are similar to stdio routines. */ + +static void +smtp_buf_init(void) +{ +/* Set up the buffer for inputting using direct read() calls, and arrange to +call the local functions instead of the standard C ones. Place a NUL at the +end of the buffer to safety-stop C-string reads from it. */ + +if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE))) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); +smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0'; + +smtp_inptr = smtp_inend = smtp_inbuffer; +smtp_had_eof = smtp_had_error = 0; +} + + + +/* Refill the buffer, and notify DKIM verification code. +Return false for error or EOF. +*/ + +static BOOL +smtp_refill(unsigned lim) { -if (smtp_inptr >= smtp_inend) +int rc, save_errno; + +if (!smtp_out) return FALSE; +fflush(smtp_out); +if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); + +/* Limit amount read, so non-message data is not fed to DKIM. +Take care to not touch the safety NUL at the end of the buffer. */ + +rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim)); +save_errno = errno; +if (smtp_receive_timeout > 0) ALARM_CLR(0); +if (rc <= 0) { - int rc, save_errno; - fflush(smtp_out); - if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); - rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size); - save_errno = errno; - alarm(0); - if (rc <= 0) + /* Must put the error text in fixed store, because this might be during + header reading, where it releases unused store above the header. */ + if (rc < 0) { - /* Must put the error text in fixed store, because this might be during - header reading, where it releases unused store above the header. */ - if (rc < 0) - { - smtp_had_error = save_errno; - smtp_read_error = string_copy_malloc( - string_sprintf(" (error: %s)", strerror(save_errno))); - } - else smtp_had_eof = 1; - return EOF; + if (had_command_timeout) /* set by signal handler */ + smtp_command_timeout_exit(); /* does not return */ + if (had_command_sigterm) + smtp_command_sigterm_exit(); + if (had_data_timeout) + smtp_data_timeout_exit(); + if (had_data_sigint) + smtp_data_sigint_exit(); + + smtp_had_error = save_errno; + smtp_read_error = string_copy_perm( + string_sprintf(" (error: %s)", strerror(save_errno)), FALSE); } + else + smtp_had_eof = 1; + return FALSE; + } #ifndef DISABLE_DKIM - dkim_exim_verify_feed(smtp_inbuffer, rc); +dkim_exim_verify_feed(smtp_inbuffer, rc); #endif - smtp_inend = smtp_inbuffer + rc; - smtp_inptr = smtp_inbuffer; - } +smtp_inend = smtp_inbuffer + rc; +smtp_inptr = smtp_inbuffer; +return TRUE; +} + + +/* Check if there is buffered data */ + +BOOL +smtp_hasc(void) +{ +return smtp_inptr < smtp_inend; +} + +/* SMTP version of getc() + +This gets the next byte from the SMTP input buffer. If the buffer is empty, +it flushes the output, and refills the buffer, with a timeout. The signal +handler is set appropriately by the calling function. This function is not used +after a connection has negotiated itself into an TLS/SSL state. + +Arguments: lim Maximum amount to read/buffer +Returns: the next character or EOF +*/ + +int +smtp_getc(unsigned lim) +{ +if (!smtp_hasc() && !smtp_refill(lim)) return EOF; return *smtp_inptr++; } +/* Get many bytes, refilling buffer if needed */ + +uschar * +smtp_getbuf(unsigned * len) +{ +unsigned size; +uschar * buf; + +if (!smtp_hasc() && !smtp_refill(*len)) + { *len = 0; return NULL; } + +if ((size = smtp_inend - smtp_inptr) > *len) size = *len; +buf = smtp_inptr; +smtp_inptr += size; +*len = size; +return buf; +} + +/* Copy buffered data to the dkim feed. +Called, unless TLS, just before starting to read message headers. */ +void +smtp_get_cache(unsigned lim) +{ +#ifndef DISABLE_DKIM +int n = smtp_inend - smtp_inptr; +if (n > lim) + n = lim; +if (n > 0) + dkim_exim_verify_feed(smtp_inptr, n); +#endif +} -/************************************************* -* SMTP version of ungetc() * -*************************************************/ -/* Puts a character back in the input buffer. Only ever -called once. +/* SMTP version of ungetc() +Puts a character back in the input buffer. Only ever called once. Arguments: ch the character @@ -295,18 +577,16 @@ Returns: the character int smtp_ungetc(int ch) { -*(--smtp_inptr) = ch; +if (smtp_inptr <= smtp_inbuffer) /* NB: NOT smtp_hasc() ! */ + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "buffer underflow in smtp_ungetc"); + +*--smtp_inptr = ch; return ch; } - - -/************************************************* -* SMTP version of feof() * -*************************************************/ - -/* Tests for a previous EOF +/* SMTP version of feof() +Tests for a previous EOF Arguments: none Returns: non-zero if the eof flag is set @@ -319,13 +599,8 @@ return smtp_had_eof; } - - -/************************************************* -* SMTP version of ferror() * -*************************************************/ - -/* Tests for a previous read error, and returns with errno +/* SMTP version of ferror() +Tests for a previous read error, and returns with errno restored to what it was when the error was detected. Arguments: none @@ -340,123 +615,426 @@ return smtp_had_error; } +/* Check if a getc will block or not */ -/************************************************* -* Test for characters in the SMTP buffer * -*************************************************/ +static BOOL +smtp_could_getc(void) +{ +int fd, rc; +fd_set fds; +struct timeval tzero = {.tv_sec = 0, .tv_usec = 0}; -/* Used at the end of a message +if (smtp_inptr < smtp_inend) + return TRUE; -Arguments: none -Returns: TRUE/FALSE -*/ +fd = fileno(smtp_in); +FD_ZERO(&fds); +FD_SET(fd, &fds); +rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); -BOOL -smtp_buffered(void) -{ -return smtp_inptr < smtp_inend; -} +if (rc <= 0) return FALSE; /* Not ready to read */ +rc = smtp_getc(GETC_BUFFER_UNLIMITED); +if (rc < 0) return FALSE; /* End of file or error */ +smtp_ungetc(rc); +return TRUE; +} +/******************************************************************************/ /************************************************* -* Write formatted string to SMTP channel * +* Recheck synchronization * *************************************************/ -/* This is a separate function so that we don't have to repeat everything for -TLS support or debugging. It is global so that the daemon and the -authentication functions can use it. It does not return any error indication, -because major problems such as dropped connections won't show up till an output -flush for non-TLS connections. The smtp_fflush() function is available for -checking that: for convenience, TLS output errors are remembered here so that -they are also picked up later by smtp_fflush(). +/* Synchronization checks can never be perfect because a packet may be on its +way but not arrived when the check is done. Normally, the checks happen when +commands are read: Exim ensures that there is no more input in the input buffer. +In normal cases, the response to the command will be fast, and there is no +further check. -Arguments: - format format string - ... optional arguments +However, for some commands an ACL is run, and that can include delays. In those +cases, it is useful to do another check on the input just before sending the +response. This also applies at the start of a connection. This function does +that check by means of the select() function, as long as the facility is not +disabled or inappropriate. A failure of select() is ignored. -Returns: nothing +When there is unwanted input, we read it so that it appears in the log of the +error. + +Arguments: none +Returns: TRUE if all is well; FALSE if there is input pending */ -void -smtp_printf(const char *format, ...) +static BOOL +wouldblock_reading(void) { -va_list ap; +#ifndef DISABLE_TLS +if (tls_in.active.sock >= 0) + return !tls_could_getc(); +#endif -va_start(ap, format); -smtp_vprintf(format, ap); -va_end(ap); +return !smtp_could_getc(); } -/* This is split off so that verify.c:respond_printf() can, in effect, call -smtp_printf(), bearing in mind that in C a vararg function can't directly -call another vararg function, only a function which accepts a va_list. */ - -void -smtp_vprintf(const char *format, va_list ap) +static BOOL +check_sync(void) { -BOOL yield; +if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket) + return TRUE; -yield = string_vformat(big_buffer, big_buffer_size, format, ap); +return wouldblock_reading(); +} -DEBUG(D_receive) - { - void *reset_point = store_get(0); - uschar *msg_copy, *cr, *end; - msg_copy = string_copy(big_buffer); - end = msg_copy + Ustrlen(msg_copy); - while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */ - memmove(cr, cr + 1, (end--) - cr); - debug_printf("SMTP>> %s", msg_copy); - store_reset(reset_point); - } -if (!yield) - { - log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()"); - smtp_closedown(US"Unexpected error"); - exim_exit(EXIT_FAILURE); - } +/******************************************************************************/ +/* Variants of the smtp_* input handling functions for use in CHUNKING mode */ -/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs -have had the same. Note: this code is also present in smtp_respond(). It would -be tidier to have it only in one place, but when it was added, it was easier to -do it that way, so as not to have to mess with the code for the RCPT command, -which sometimes uses smtp_printf() and sometimes smtp_respond(). */ +/* Forward declarations */ +static inline void bdat_push_receive_functions(void); +static inline void bdat_pop_receive_functions(void); -if (rcpt_in_progress) - { - if (rcpt_smtp_response == NULL) - rcpt_smtp_response = string_copy(big_buffer); - else if (rcpt_smtp_response_same && - Ustrcmp(rcpt_smtp_response, big_buffer) != 0) - rcpt_smtp_response_same = FALSE; - rcpt_in_progress = FALSE; - } -/* Now write the string */ +/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the +previous BDAT chunk and getting new ones when we run out. Uses the +underlying smtp_getc or tls_getc both for that and for getting the +(buffered) data byte. EOD signals (an expected) no further data. +ERR signals a protocol error, and EOF a closed input stream. + +Called from read_bdat_smtp() in receive.c for the message body, but also +by the headers read loop in receive_msg(); manipulates chunking_state +to handle the BDAT command/response. +Placed here due to the correlation with the above smtp_getc(), which it wraps, +and also by the need to do smtp command/response handling. + +Arguments: lim (ignored) +Returns: the next character or ERR, EOD or EOF +*/ + +int +bdat_getc(unsigned lim) +{ +uschar * user_msg = NULL; +uschar * log_msg; -#ifdef SUPPORT_TLS -if (tls_active >= 0) +for(;;) { - if (tls_write(big_buffer, Ustrlen(big_buffer)) < 0) smtp_write_error = -1; - } -else +#ifndef DISABLE_DKIM + unsigned dkim_save; #endif -if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1; -} + if (chunking_data_left > 0) + return lwr_receive_getc(chunking_data_left--); + bdat_pop_receive_functions(); +#ifndef DISABLE_DKIM + dkim_save = dkim_collect_input; + dkim_collect_input = 0; +#endif + /* Unless PIPELINING was offered, there should be no next command + until after we ack that chunk */ -/************************************************* + if (!f.smtp_in_pipelining_advertised && !check_sync()) + { + unsigned n = smtp_inend - smtp_inptr; + if (n > 32) n = 32; + + incomplete_transaction_log(US"sync failure"); + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error " + "(next input sent too soon: pipelining was not advertised): " + "rejected \"%s\" %s next input=\"%s\"%s", + smtp_cmd_buffer, host_and_ident(TRUE), + string_printing(string_copyn(smtp_inptr, n)), + smtp_inend - smtp_inptr > n ? "..." : ""); + (void) synprot_error(L_smtp_protocol_error, 554, NULL, + US"SMTP synchronization error"); + goto repeat_until_rset; + } + + /* If not the last, ack the received chunk. The last response is delayed + until after the data ACL decides on it */ + + if (chunking_state == CHUNKING_LAST) + { +#ifndef DISABLE_DKIM + dkim_collect_input = dkim_save; + dkim_exim_verify_feed(NULL, 0); /* notify EOD */ + dkim_collect_input = 0; +#endif + return EOD; + } + + smtp_printf("250 %u byte chunk received\r\n", SP_NO_MORE, chunking_datasize); + chunking_state = CHUNKING_OFFERED; + DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state); + + /* Expect another BDAT cmd from input. RFC 3030 says nothing about + QUIT, RSET or NOOP but handling them seems obvious */ + +next_cmd: + switch(smtp_read_command(TRUE, 1)) + { + default: + (void) synprot_error(L_smtp_protocol_error, 503, NULL, + US"only BDAT permissible after non-LAST BDAT"); + + repeat_until_rset: + switch(smtp_read_command(TRUE, 1)) + { + case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */ + case EOF_CMD: return EOF; + case RSET_CMD: smtp_rset_handler(); return ERR; + default: if (synprot_error(L_smtp_protocol_error, 503, NULL, + US"only RSET accepted now") > 0) + return EOF; + goto repeat_until_rset; + } + + case QUIT_CMD: + smtp_quit_handler(&user_msg, &log_msg); + /*FALLTHROUGH*/ + case EOF_CMD: + return EOF; + + case RSET_CMD: + smtp_rset_handler(); + return ERR; + + case NOOP_CMD: + HAD(SCH_NOOP); + smtp_printf("250 OK\r\n", SP_NO_MORE); + goto next_cmd; + + case BDAT_CMD: + { + int n; + + if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1) + { + (void) synprot_error(L_smtp_protocol_error, 501, NULL, + US"missing size for BDAT command"); + return ERR; + } + chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0 + ? CHUNKING_LAST : CHUNKING_ACTIVE; + chunking_data_left = chunking_datasize; + DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n", + (int)chunking_state, chunking_data_left); + + if (chunking_datasize == 0) + if (chunking_state == CHUNKING_LAST) + return EOD; + else + { + (void) synprot_error(L_smtp_protocol_error, 504, NULL, + US"zero size for BDAT command"); + goto repeat_until_rset; + } + + bdat_push_receive_functions(); +#ifndef DISABLE_DKIM + dkim_collect_input = dkim_save; +#endif + break; /* to top of main loop */ + } + } + } +} + +BOOL +bdat_hasc(void) +{ +if (chunking_data_left > 0) + return lwr_receive_hasc(); +return TRUE; +} + +uschar * +bdat_getbuf(unsigned * len) +{ +uschar * buf; + +if (chunking_data_left <= 0) + { *len = 0; return NULL; } + +if (*len > chunking_data_left) *len = chunking_data_left; +buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */ +chunking_data_left -= *len; +return buf; +} + +void +bdat_flush_data(void) +{ +while (chunking_data_left) + { + unsigned n = chunking_data_left; + if (!bdat_getbuf(&n)) break; + } + +bdat_pop_receive_functions(); +chunking_state = CHUNKING_OFFERED; +DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state); +} + + +static inline void +bdat_push_receive_functions(void) +{ +/* push the current receive_* function on the "stack", and +replace them by bdat_getc(), which in turn will use the lwr_receive_* +functions to do the dirty work. */ +if (!lwr_receive_getc) + { + lwr_receive_getc = receive_getc; + lwr_receive_getbuf = receive_getbuf; + lwr_receive_hasc = receive_hasc; + lwr_receive_ungetc = receive_ungetc; + } +else + { + DEBUG(D_receive) debug_printf("chunking double-push receive functions\n"); + } + +receive_getc = bdat_getc; +receive_getbuf = bdat_getbuf; +receive_hasc = bdat_hasc; +receive_ungetc = bdat_ungetc; +} + +static inline void +bdat_pop_receive_functions(void) +{ +if (!lwr_receive_getc) + { + DEBUG(D_receive) debug_printf("chunking double-pop receive functions\n"); + return; + } +receive_getc = lwr_receive_getc; +receive_getbuf = lwr_receive_getbuf; +receive_hasc = lwr_receive_hasc; +receive_ungetc = lwr_receive_ungetc; + +lwr_receive_getc = NULL; +lwr_receive_getbuf = NULL; +lwr_receive_hasc = NULL; +lwr_receive_ungetc = NULL; +} + +int +bdat_ungetc(int ch) +{ +chunking_data_left++; +bdat_push_receive_functions(); /* we're not done yet, calling push is safe, because it checks the state before pushing anything */ +return lwr_receive_ungetc(ch); +} + + + +/******************************************************************************/ + +/************************************************* +* Write formatted string to SMTP channel * +*************************************************/ + +/* This is a separate function so that we don't have to repeat everything for +TLS support or debugging. It is global so that the daemon and the +authentication functions can use it. It does not return any error indication, +because major problems such as dropped connections won't show up till an output +flush for non-TLS connections. The smtp_fflush() function is available for +checking that: for convenience, TLS output errors are remembered here so that +they are also picked up later by smtp_fflush(). + +This function is exposed to the local_scan API; do not change the signature. + +Arguments: + format format string + more further data expected + ... optional arguments + +Returns: nothing +*/ + +void +smtp_printf(const char *format, BOOL more, ...) +{ +va_list ap; + +va_start(ap, more); +smtp_vprintf(format, more, ap); +va_end(ap); +} + +/* This is split off so that verify.c:respond_printf() can, in effect, call +smtp_printf(), bearing in mind that in C a vararg function can't directly +call another vararg function, only a function which accepts a va_list. + +This function is exposed to the local_scan API; do not change the signature. +*/ +/*XXX consider passing caller-info in, for string_vformat-onward */ + +void +smtp_vprintf(const char *format, BOOL more, va_list ap) +{ +gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; +BOOL yield; + +/* Use taint-unchecked routines for writing into big_buffer, trusting +that we'll never expand it. */ + +yield = !! string_vformat(&gs, SVFMT_TAINT_NOCHK, format, ap); +string_from_gstring(&gs); + +DEBUG(D_receive) for (const uschar * t, * s = gs.s; + s && (t = Ustrchr(s, '\r')); + s = t + 2) /* \r\n */ + debug_printf("%s %.*s\n", + s == gs.s ? "SMTP>>" : " ", + (int)(t - s), s); + +if (!yield) + { + log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()"); + smtp_closedown(US"Unexpected error"); + exim_exit(EXIT_FAILURE); + } + +/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs +have had the same. Note: this code is also present in smtp_respond(). It would +be tidier to have it only in one place, but when it was added, it was easier to +do it that way, so as not to have to mess with the code for the RCPT command, +which sometimes uses smtp_printf() and sometimes smtp_respond(). */ + +if (fl.rcpt_in_progress) + { + if (!rcpt_smtp_response) + rcpt_smtp_response = string_copy(big_buffer); + else if (fl.rcpt_smtp_response_same && + Ustrcmp(rcpt_smtp_response, big_buffer) != 0) + fl.rcpt_smtp_response_same = FALSE; + fl.rcpt_in_progress = FALSE; + } + +/* Now write the string */ + +if ( +#ifndef DISABLE_TLS + tls_in.active.sock >= 0 ? (tls_write(NULL, gs.s, gs.ptr, more) < 0) : +#endif + (fwrite(gs.s, gs.ptr, 1, smtp_out) == 0) + ) + smtp_write_error = -1; +} + + + +/************************************************* * Flush SMTP out and check for error * *************************************************/ /* This function isn't currently used within Exim (it detects errors when it tries to read the next SMTP input), but is available for use in local_scan(). -For non-TLS connections, it flushes the output and checks for errors. For -TLS-connections, it checks for a previously-detected TLS write error. +It flushes the output and checks for errors. Arguments: none Returns: 0 for no error; -1 after an error @@ -465,12 +1043,50 @@ Returns: 0 for no error; -1 after an error int smtp_fflush(void) { -if (tls_active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1; +if (tls_in.active.sock < 0 && fflush(smtp_out) != 0) smtp_write_error = -1; + +if ( +#ifndef DISABLE_TLS + tls_in.active.sock >= 0 ? (tls_write(NULL, NULL, 0, FALSE) < 0) : +#endif + (fflush(smtp_out) != 0) + ) + smtp_write_error = -1; + return smtp_write_error; } +/* If there's input waiting (and we're doing pipelineing) then we can pipeline +a reponse with the one following. */ + +static BOOL +pipeline_response(void) +{ +if ( !smtp_enforce_sync || !sender_host_address + || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised) + return FALSE; + +if (wouldblock_reading()) return FALSE; +f.smtp_in_pipelining_used = TRUE; +return TRUE; +} + + +#ifndef DISABLE_PIPE_CONNECT +static BOOL +pipeline_connect_sends(void) +{ +if (!sender_host_address || f.sender_host_notsocket || !fl.pipe_connect_acceptable) + return FALSE; + +if (wouldblock_reading()) return FALSE; +f.smtp_in_early_pipe_used = TRUE; +return TRUE; +} +#endif + /************************************************* * SMTP command read timeout * *************************************************/ @@ -485,16 +1101,7 @@ Returns: nothing static void command_timeout_handler(int sig) { -sig = sig; /* Keep picky compilers happy */ -log_write(L_lost_incoming_connection, - LOG_MAIN, "SMTP command timeout on%s connection from %s", - (tls_active >= 0)? " TLS" : "", - host_and_ident(FALSE)); -if (smtp_batched_input) - moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */ -smtp_notquit_exit(US"command-timeout", US"421", - US"%s: SMTP command timeout - closing connection", smtp_active_hostname); -exim_exit(EXIT_FAILURE); +had_command_timeout = sig; } @@ -512,13 +1119,7 @@ Returns: nothing static void command_sigterm_handler(int sig) { -sig = sig; /* Keep picky compilers happy */ -log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info()); -if (smtp_batched_input) - moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */ -smtp_notquit_exit(US"signal-exit", US"421", - US"%s: Service not available - closing connection", smtp_active_hostname); -exim_exit(EXIT_FAILURE); +had_command_sigterm = sig; } @@ -541,24 +1142,25 @@ signal handler that closes down the session on a timeout. Control does not return when it runs. Arguments: - check_sync if TRUE, check synchronization rules if global option is TRUE + check_sync if TRUE, check synchronization rules if global option is TRUE + buffer_lim maximum to buffer in lower layer Returns: a code identifying the command (enumerated above) */ static int -smtp_read_command(BOOL check_sync) +smtp_read_command(BOOL check_sync, unsigned buffer_lim) { int c; int ptr = 0; -smtp_cmd_list *p; BOOL hadnull = FALSE; +had_command_timeout = 0; os_non_restarting_signal(SIGALRM, command_timeout_handler); -while ((c = (receive_getc)()) != '\n' && c != EOF) +while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF) { - if (ptr >= smtp_cmd_buffer_size) + if (ptr >= SMTP_CMD_BUFFER_SIZE) { os_non_restarting_signal(SIGALRM, sigalrm_handler); return OTHER_CMD; @@ -595,19 +1197,27 @@ if (hadnull) return BADCHAR_CMD; to the start of the actual data characters. Check for SMTP synchronization if required. */ -for (p = cmd_list; p < cmd_list_end; p++) +for (smtp_cmd_list * p = cmd_list; p < cmd_list + nelem(cmd_list); p++) { - if (strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 && - (smtp_cmd_buffer[p->len-1] == ':' || /* "mail from:" or "rcpt to:" */ - smtp_cmd_buffer[p->len] == 0 || - smtp_cmd_buffer[p->len] == ' ')) +#ifdef SUPPORT_PROXY + /* Only allow QUIT command if Proxy Protocol parsing failed */ + if (proxy_session && f.proxy_session_failed && p->cmd != QUIT_CMD) + continue; +#endif + if ( p->len + && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 + && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */ + || smtp_cmd_buffer[p->len] == 0 + || smtp_cmd_buffer[p->len] == ' ' + ) ) { - if (smtp_inptr < smtp_inend && /* Outstanding input */ - p->cmd < sync_cmd_limit && /* Command should sync */ - check_sync && /* Local flag set */ - smtp_enforce_sync && /* Global flag set */ - sender_host_address != NULL && /* Not local input */ - !sender_host_notsocket) /* Really is a socket */ + if ( smtp_inptr < smtp_inend /* Outstanding input */ + && p->cmd < sync_cmd_limit /* Command should sync */ + && check_sync /* Local flag set */ + && smtp_enforce_sync /* Global flag set */ + && sender_host_address != NULL /* Not local input */ + && !f.sender_host_notsocket /* Really is a socket */ + ) return BADSYN_CMD; /* The variables $smtp_command and $smtp_command_argument point into the @@ -617,7 +1227,7 @@ for (p = cmd_list; p < cmd_list_end; p++) follow the sender address. */ smtp_cmd_argument = smtp_cmd_buffer + p->len; - while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++; + Uskip_whitespace(&smtp_cmd_argument); Ustrcpy(smtp_data_buffer, smtp_cmd_argument); smtp_cmd_data = smtp_data_buffer; @@ -644,13 +1254,20 @@ for (p = cmd_list; p < cmd_list_end; p++) } } +#ifdef SUPPORT_PROXY +/* Only allow QUIT command if Proxy Protocol parsing failed */ +if (proxy_session && f.proxy_session_failed) + return PROXY_FAIL_IGNORE_CMD; +#endif + /* Enforce synchronization for unknown commands */ -if (smtp_inptr < smtp_inend && /* Outstanding input */ - check_sync && /* Local flag set */ - smtp_enforce_sync && /* Global flag set */ - sender_host_address != NULL && /* Not local input */ - !sender_host_notsocket) /* Really is a socket */ +if ( smtp_inptr < smtp_inend /* Outstanding input */ + && check_sync /* Local flag set */ + && smtp_enforce_sync /* Global flag set */ + && sender_host_address /* Not local input */ + && !f.sender_host_notsocket /* Really is a socket */ + ) return BADSYN_CMD; return OTHER_CMD; @@ -658,59 +1275,6 @@ return OTHER_CMD; -/************************************************* -* Recheck synchronization * -*************************************************/ - -/* Synchronization checks can never be perfect because a packet may be on its -way but not arrived when the check is done. Such checks can in any case only be -done when TLS is not in use. Normally, the checks happen when commands are -read: Exim ensures that there is no more input in the input buffer. In normal -cases, the response to the command will be fast, and there is no further check. - -However, for some commands an ACL is run, and that can include delays. In those -cases, it is useful to do another check on the input just before sending the -response. This also applies at the start of a connection. This function does -that check by means of the select() function, as long as the facility is not -disabled or inappropriate. A failure of select() is ignored. - -When there is unwanted input, we read it so that it appears in the log of the -error. - -Arguments: none -Returns: TRUE if all is well; FALSE if there is input pending -*/ - -static BOOL -check_sync(void) -{ -int fd, rc; -fd_set fds; -struct timeval tzero; - -if (!smtp_enforce_sync || sender_host_address == NULL || - sender_host_notsocket || tls_active >= 0) - return TRUE; - -fd = fileno(smtp_in); -FD_ZERO(&fds); -FD_SET(fd, &fds); -tzero.tv_sec = 0; -tzero.tv_usec = 0; -rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); - -if (rc <= 0) return TRUE; /* Not ready to read */ -rc = smtp_getc(); -if (rc < 0) return TRUE; /* End of file or error */ - -smtp_ungetc(rc); -rc = smtp_inend - smtp_inptr; -if (rc > 150) rc = 150; -smtp_inptr[rc] = 0; -return FALSE; -} - - /************************************************* * Forced closedown of call * @@ -730,32 +1294,30 @@ Returns: nothing */ void -smtp_closedown(uschar *message) +smtp_closedown(uschar * message) { -if (smtp_in == NULL || smtp_batched_input) return; +if (!smtp_in || smtp_batched_input) return; receive_swallow_smtp(); -smtp_printf("421 %s\r\n", message); +smtp_printf("421 %s\r\n", SP_NO_MORE, message); -for (;;) +for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED)) { - switch(smtp_read_command(FALSE)) - { - case EOF_CMD: + case EOF_CMD: return; - case QUIT_CMD: - smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); + case QUIT_CMD: + f.smtp_in_quit = TRUE; + smtp_printf("221 %s closing connection\r\n", SP_NO_MORE, smtp_active_hostname); mac_smtp_fflush(); return; - case RSET_CMD: - smtp_printf("250 Reset OK\r\n"); + case RSET_CMD: + smtp_printf("250 Reset OK\r\n", SP_NO_MORE); break; - default: - smtp_printf("421 %s\r\n", message); + default: + smtp_printf("421 %s\r\n", SP_NO_MORE, message); break; - } } } @@ -778,26 +1340,82 @@ Returns: a string describing the connection uschar * smtp_get_connection_info(void) { -uschar *hostname = (sender_fullhost == NULL)? - sender_host_address : sender_fullhost; +const uschar * hostname = sender_fullhost + ? sender_fullhost : sender_host_address; +gstring * g = string_catn(NULL, US"SMTP connection", 15); + +if (LOGGING(connection_id)) + g = string_fmt_append(g, " Ci=%lu", connection_id); +g = string_catn(g, US" from ", 6); if (host_checking) - return string_sprintf("SMTP connection from %s", hostname); + g = string_cat(g, hostname); + +else if (f.sender_host_unknown || f.sender_host_notsocket) + g = string_cat(g, sender_ident ? sender_ident : US"NULL"); + +else if (f.is_inetd) + g = string_append(g, 2, hostname, US" (via inetd)"); + +else if (LOGGING(incoming_interface) && interface_address) + g = string_fmt_append(g, "%s I=[%s]:%d", hostname, interface_address, interface_port); + +else + g = string_cat(g, hostname); + +gstring_release_unused(g); +return string_from_gstring(g); +} + -if (sender_host_unknown || sender_host_notsocket) - return string_sprintf("SMTP connection from %s", sender_ident); -if (is_inetd) - return string_sprintf("SMTP connection from %s (via inetd)", hostname); +#ifndef DISABLE_TLS +/* Append TLS-related information to a log line -if ((log_extra_selector & LX_incoming_interface) != 0 && - interface_address != NULL) - return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname, - interface_address, interface_port); +Arguments: + g String under construction: allocated string to extend, or NULL -return string_sprintf("SMTP connection from %s", hostname); +Returns: Allocated string or NULL +*/ +static gstring * +s_tlslog(gstring * g) +{ +if (LOGGING(tls_cipher) && tls_in.cipher) + { + g = string_append(g, 2, US" X=", tls_in.cipher); +#ifndef DISABLE_TLS_RESUME + if (LOGGING(tls_resumption) && tls_in.resumption & RESUME_USED) + g = string_catn(g, US"*", 1); +#endif + } +if (LOGGING(tls_certificate_verified) && tls_in.cipher) + g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no"); +if (LOGGING(tls_peerdn) && tls_in.peerdn) + g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\""); +if (LOGGING(tls_sni) && tls_in.sni) + g = string_append(g, 2, US" SNI=", string_printing2(tls_in.sni, SP_TAB|SP_SPACE)); +return g; } +#endif + + + +static gstring * +s_connhad_log(gstring * g) +{ +const uschar * sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE + ? US" C=..." : US" C="; +for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++) + if (smtp_connection_had[i] != SCH_NONE) + { + g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]); + sep = US","; + } +for (int i = 0; i < smtp_ch_index; i++, sep = US",") + g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]); +return g; +} /************************************************* @@ -815,70 +1433,61 @@ Returns: nothing void smtp_log_no_mail(void) { -int size, ptr, i; -uschar *s, *sep; +uschar * s; +gstring * g = NULL; -if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0) +if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail)) return; -s = NULL; -size = ptr = 0; - -if (sender_host_authenticated != NULL) +if (sender_host_authenticated) { - s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated); - if (authenticated_id != NULL) - s = string_append(s, &size, &ptr, 2, US":", authenticated_id); + g = string_append(g, 2, US" A=", sender_host_authenticated); + if (authenticated_id) g = string_append(g, 2, US":", authenticated_id); } -#ifdef SUPPORT_TLS -if ((log_extra_selector & LX_tls_cipher) != 0 && tls_cipher != NULL) - s = string_append(s, &size, &ptr, 2, US" X=", tls_cipher); -if ((log_extra_selector & LX_tls_certificate_verified) != 0 && - tls_cipher != NULL) - s = string_append(s, &size, &ptr, 2, US" CV=", - tls_certificate_verified? "yes":"no"); -if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_peerdn != NULL) - s = string_append(s, &size, &ptr, 3, US" DN=\"", - string_printing(tls_peerdn), US"\""); -if ((log_extra_selector & LX_tls_sni) != 0 && tls_sni != NULL) - s = string_append(s, &size, &ptr, 3, US" SNI=\"", - string_printing(tls_sni), US"\""); +#ifndef DISABLE_TLS +g = s_tlslog(g); #endif -sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)? - US" C=..." : US" C="; -for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++) - { - if (smtp_connection_had[i] != SCH_NONE) - { - s = string_append(s, &size, &ptr, 2, sep, - smtp_names[smtp_connection_had[i]]); - sep = US","; - } - } +g = s_connhad_log(g); -for (i = 0; i < smtp_ch_index; i++) - { - s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]); - sep = US","; - } +if (!(s = string_from_gstring(g))) s = US""; -if (s != NULL) s[ptr] = 0; else s = US""; -log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s", - host_and_ident(FALSE), - readconf_printtime(time(NULL) - smtp_connection_start), s); +log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s", + f.tcp_in_fastopen ? f.tcp_in_fastopen_data ? US"TFO* " : US"TFO " : US"", + host_and_ident(FALSE), string_timesince(&smtp_connection_start), s); } +/* Return list of recent smtp commands */ -/************************************************* -* Check HELO line and set sender_helo_name * -*************************************************/ +uschar * +smtp_cmd_hist(void) +{ +gstring * list = NULL; +uschar * s; + +for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++) + if (smtp_connection_had[i] != SCH_NONE) + list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]); + +for (int i = 0; i < smtp_ch_index; i++) + list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]); + +s = string_from_gstring(list); +return s ? s : US""; +} + + + + +/************************************************* +* Check HELO line and set sender_helo_name * +*************************************************/ /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be the domain name of the sending host, or an ip literal in square brackets. The -arrgument is placed in sender_helo_name, which is in malloc store, because it +argument is placed in sender_helo_name, which is in malloc store, because it must persist over multiple incoming messages. If helo_accept_junk is set, this host is permitted to send any old junk (needed for some broken hosts). Otherwise, helo_allow_chars can be used for rogue characters in general @@ -895,20 +1504,16 @@ check_helo(uschar *s) { uschar *start = s; uschar *end = s + Ustrlen(s); -BOOL yield = helo_accept_junk; +BOOL yield = fl.helo_accept_junk; /* Discard any previous helo name */ -if (sender_helo_name != NULL) - { - store_free(sender_helo_name); - sender_helo_name = NULL; - } +sender_helo_name = NULL; /* Skip tests if junk is permitted. */ if (!yield) - { + /* Allow the new standard form for IPv6 address literals, namely, [IPv6:....], and because someone is bound to use it, allow an equivalent IPv4 form. Allow plain addresses as well. */ @@ -931,25 +1536,18 @@ if (!yield) /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars that have been configured (usually underscore - sigh). */ - else if (*s != 0) - { - yield = TRUE; - while (*s != 0) - { + else if (*s) + for (yield = TRUE; *s; s++) if (!isalnum(*s) && *s != '.' && *s != '-' && Ustrchr(helo_allow_chars, *s) == NULL) { yield = FALSE; break; } - s++; - } - } - } /* Save argument if OK */ -if (yield) sender_helo_name = string_copy_malloc(start); +if (yield) sender_helo_name = string_copy_perm(start, TRUE); return yield; } @@ -976,22 +1574,38 @@ static BOOL extract_option(uschar **name, uschar **value) { uschar *n; -uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1; -while (isspace(*v)) v--; +uschar *v; +if (Ustrlen(smtp_cmd_data) <= 0) return FALSE; +v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1; +while (v > smtp_cmd_data && isspace(*v)) v--; v[1] = 0; -while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--; -if (*v != '=') return FALSE; +while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) + { + /* Take care to not stop at a space embedded in a quoted local-part */ + if (*v == '"') + { + do v--; while (v > smtp_cmd_data && *v != '"'); + if (v <= smtp_cmd_data) return FALSE; + } + v--; + } +if (v <= smtp_cmd_data) return FALSE; n = v; -while(isalpha(n[-1])) n--; - -/* RFC says SP, but TAB seen in wild and other major MTAs accept it */ -if (!isspace(n[-1])) return FALSE; - -n[-1] = 0; -*name = n; +if (*v == '=') + { + while (n > smtp_cmd_data && isalpha(n[-1])) n--; + /* RFC says SP, but TAB seen in wild and other major MTAs accept it */ + if (n <= smtp_cmd_data || !isspace(n[-1])) return FALSE; + n[-1] = 0; + } +else + { + n++; + } *v++ = 0; +*name = n; *value = v; return TRUE; } @@ -1005,61 +1619,95 @@ return TRUE; *************************************************/ /* This function is called whenever the SMTP session is reset from -within either of the setup functions. +within either of the setup functions; also from the daemon loop. Argument: the stacking pool storage reset point Returns: nothing */ -static void +void * smtp_reset(void *reset_point) { -store_reset(reset_point); recipients_list = NULL; rcpt_count = rcpt_defer_count = rcpt_fail_count = raw_recipients_count = recipients_count = recipients_list_max = 0; message_linecount = 0; message_size = -1; +message_body = message_body_end = NULL; acl_added_headers = NULL; -queue_only_policy = FALSE; +acl_removed_headers = NULL; +f.queue_only_policy = FALSE; rcpt_smtp_response = NULL; -rcpt_smtp_response_same = TRUE; -rcpt_in_progress = FALSE; -deliver_freeze = FALSE; /* Can be set by ACL */ -freeze_tell = freeze_tell_config; /* Can be set by ACL */ -fake_response = OK; /* Can be set by ACL */ +fl.rcpt_smtp_response_same = TRUE; +fl.rcpt_in_progress = FALSE; +f.deliver_freeze = FALSE; /* Can be set by ACL */ +freeze_tell = freeze_tell_config; /* Can be set by ACL */ +fake_response = OK; /* Can be set by ACL */ #ifdef WITH_CONTENT_SCAN -no_mbox_unspool = FALSE; /* Can be set by ACL */ +f.no_mbox_unspool = FALSE; /* Can be set by ACL */ #endif -submission_mode = FALSE; /* Can be set by ACL */ -suppress_local_fixups = FALSE; /* Can be set by ACL */ -active_local_from_check = local_from_check; /* Can be set by ACL */ -active_local_sender_retain = local_sender_retain; /* Can be set by ACL */ -sender_address = NULL; -submission_name = NULL; /* Can be set by ACL */ +f.submission_mode = FALSE; /* Can be set by ACL */ +f.suppress_local_fixups = f.suppress_local_fixups_default; /* Can be set by ACL */ +f.active_local_from_check = local_from_check; /* Can be set by ACL */ +f.active_local_sender_retain = local_sender_retain; /* Can be set by ACL */ +sending_ip_address = NULL; +return_path = sender_address = NULL; +deliver_localpart_data = deliver_domain_data = +recipient_data = sender_data = NULL; /* Can be set by ACL */ +recipient_verify_failure = NULL; +deliver_localpart_parent = deliver_localpart_orig = NULL; +deliver_domain_parent = deliver_domain_orig = NULL; +callout_address = NULL; +submission_name = NULL; /* Can be set by ACL */ raw_sender = NULL; /* After SMTP rewrite, before qualifying */ sender_address_unrewritten = NULL; /* Set only after verify rewrite */ sender_verified_list = NULL; /* No senders verified */ memset(sender_address_cache, 0, sizeof(sender_address_cache)); memset(sender_domain_cache, 0, sizeof(sender_domain_cache)); + authenticated_sender = NULL; #ifdef EXPERIMENTAL_BRIGHTMAIL bmi_run = 0; bmi_verdicts = NULL; #endif +dnslist_domain = dnslist_matched = NULL; +#ifdef SUPPORT_SPF +spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL; +spf_result_guessed = FALSE; +#endif #ifndef DISABLE_DKIM -dkim_signers = NULL; -dkim_disable_verify = FALSE; -dkim_collect_input = FALSE; +dkim_cur_signer = dkim_signers = +dkim_signing_domain = dkim_signing_selector = dkim_signatures = NULL; +dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL; +f.dkim_disable_verify = FALSE; +dkim_collect_input = 0; +dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL; +dkim_key_length = 0; +#endif +#ifdef SUPPORT_DMARC +f.dmarc_has_been_checked = f.dmarc_disable_verify = f.dmarc_enable_forensic = FALSE; +dmarc_domain_policy = dmarc_status = dmarc_status_text = +dmarc_used_domain = NULL; +#endif +#ifdef EXPERIMENTAL_ARC +arc_state = arc_state_reason = NULL; +arc_received_instance = 0; #endif -#ifdef EXPERIMENTAL_SPF -spf_header_comment = NULL; -spf_received = NULL; -spf_result = NULL; -spf_smtp_comment = NULL; +dsn_ret = 0; +dsn_envid = NULL; +deliver_host = deliver_host_address = NULL; /* Can be set by ACL */ +#ifndef DISABLE_PRDR +prdr_requested = FALSE; +#endif +#ifdef SUPPORT_I18N +message_smtputf8 = FALSE; +#endif +#ifdef WITH_CONTENT_SCAN +regex_vars_clear(); #endif body_linecount = body_zerocount = 0; +lookup_value = NULL; /* Can be set by ACL */ sender_rate = sender_rate_limit = sender_rate_period = NULL; ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */ /* Note that ratelimiters_conn persists across resets. */ @@ -1068,32 +1716,22 @@ ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */ acl_var_m = NULL; -/* The message body variables use malloc store. They may be set if this is -not the first message in an SMTP session and the previous message caused them -to be referenced in an ACL. */ - -if (message_body != NULL) - { - store_free(message_body); - message_body = NULL; - } - -if (message_body_end != NULL) - { - store_free(message_body_end); - message_body_end = NULL; - } - -/* Warning log messages are also saved in malloc store. They are saved to avoid +/* Warning log messages are saved in malloc store. They are saved to avoid repetition in the same message, but it seems right to repeat them for different messages. */ -while (acl_warn_logged != NULL) +while (acl_warn_logged) { string_item *this = acl_warn_logged; acl_warn_logged = acl_warn_logged->next; store_free(this); } + +message_tidyup(); +store_reset(reset_point); + +message_start(); +return store_mark(); } @@ -1121,7 +1759,7 @@ static int smtp_setup_batch_msg(void) { int done = 0; -void *reset_point = store_get(0); +rmark reset_point = store_mark(); /* Save the line count at the start of each transaction - single commands like HELO and RSET count as whole transactions. */ @@ -1130,7 +1768,8 @@ bsmtp_transaction_linecount = receive_linecount; if ((receive_feof)()) return 0; /* Treat EOF as QUIT */ -smtp_reset(reset_point); /* Reset for start of message */ +cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg"); +reset_point = smtp_reset(reset_point); /* Reset for start of message */ /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE value. The values are 2 larger than the required yield of the function. */ @@ -1141,7 +1780,7 @@ while (done <= 0) uschar *recipient = NULL; int start, end, sender_domain, recipient_domain; - switch(smtp_read_command(FALSE)) + switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED)) { /* The HELO/EHLO commands set sender_address_helo if they have valid data; otherwise they are ignored, except that they do @@ -1150,14 +1789,14 @@ while (done <= 0) case HELO_CMD: case EHLO_CMD: - check_helo(smtp_cmd_data); - /* Fall through */ + check_helo(smtp_cmd_data); + /* Fall through */ case RSET_CMD: - smtp_reset(reset_point); - bsmtp_transaction_linecount = receive_linecount; - break; - + cancel_cutthrough_connection(TRUE, US"RSET received"); + reset_point = smtp_reset(reset_point); + bsmtp_transaction_linecount = receive_linecount; + break; /* The MAIL FROM command requires an address as an operand. All we do here is to parse it for syntactic correctness. The form "<>" is @@ -1166,51 +1805,56 @@ while (done <= 0) it is the canonical extracted address which is all that is kept. */ case MAIL_CMD: - if (sender_address != NULL) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given"); - - if (smtp_cmd_data[0] == 0) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand"); - - /* Reset to start of message */ - - smtp_reset(reset_point); - - /* Apply SMTP rewrite */ - - raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? - rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE, - US"", global_rewrite_rules) : smtp_cmd_data; - - /* Extract the address; the TRUE flag allows <> as valid */ - - raw_sender = - parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, - TRUE); - - if (raw_sender == NULL) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); - - sender_address = string_copy(raw_sender); - - /* Qualify unqualified sender addresses if permitted to do so. */ - - if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@') - { - if (allow_unqualified_sender) - { - sender_address = rewrite_address_qualify(sender_address, FALSE); - DEBUG(D_receive) debug_printf("unqualified address %s accepted " - "and rewritten\n", raw_sender); - } - /* The function moan_smtp_batch() does not return. */ - else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain " - "a domain"); - } - break; + smtp_mailcmd_count++; /* Count for no-mail log */ + if (sender_address) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given"); + + if (smtp_cmd_data[0] == 0) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand"); + + /* Reset to start of message */ + + cancel_cutthrough_connection(TRUE, US"MAIL received"); + reset_point = smtp_reset(reset_point); + + /* Apply SMTP rewrite */ + + raw_sender = rewrite_existflags & rewrite_smtp + /* deconst ok as smtp_cmd_data was not const */ + ? US rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, + FALSE, US"", global_rewrite_rules) + : smtp_cmd_data; + + /* Extract the address; the TRUE flag allows <> as valid */ + + raw_sender = + parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, + TRUE); + + if (!raw_sender) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); + + sender_address = string_copy(raw_sender); + + /* Qualify unqualified sender addresses if permitted to do so. */ + + if ( !sender_domain + && sender_address[0] != 0 && sender_address[0] != '@') + if (f.allow_unqualified_sender) + { + /* deconst ok as sender_address was not const */ + sender_address = US rewrite_address_qualify(sender_address, FALSE); + DEBUG(D_receive) debug_printf("unqualified address %s accepted " + "and rewritten\n", raw_sender); + } + /* The function moan_smtp_batch() does not return. */ + else + moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain " + "a domain"); + break; /* The RCPT TO command requires an address as an operand. All we do @@ -1221,54 +1865,57 @@ while (done <= 0) extracted address. */ case RCPT_CMD: - if (sender_address == NULL) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given"); + if (!sender_address) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given"); + + if (smtp_cmd_data[0] == 0) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, + "501 RCPT TO must have an address operand"); + + /* Check maximum number allowed */ + + if ( recipients_max_expanded > 0 + && recipients_count + 1 > recipients_max_expanded) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients", + recipients_max_reject ? "552": "452"); + + /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a + recipient address */ + + recipient = rewrite_existflags & rewrite_smtp + /* deconst ok as smtp_cmd_data was not const */ + ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + global_rewrite_rules) + : smtp_cmd_data; + + recipient = parse_extract_address(recipient, &errmess, &start, &end, + &recipient_domain, FALSE); + + if (!recipient) + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); + + /* If the recipient address is unqualified, qualify it if permitted. Then + add it to the list of recipients. */ + + if (!recipient_domain) + if (f.allow_unqualified_recipient) + { + DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", + recipient); + /* deconst ok as recipient was not const */ + recipient = US rewrite_address_qualify(recipient, TRUE); + } + /* The function moan_smtp_batch() does not return. */ + else + moan_smtp_batch(smtp_cmd_buffer, + "501 recipient address must contain a domain"); - if (smtp_cmd_data[0] == 0) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand"); - - /* Check maximum number allowed */ - - if (recipients_max > 0 && recipients_count + 1 > recipients_max) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients", - recipients_max_reject? "552": "452"); - - /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a - recipient address */ - - recipient = ((rewrite_existflags & rewrite_smtp) != 0)? - rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", - global_rewrite_rules) : smtp_cmd_data; - - /* rfc821_domains = TRUE; << no longer needed */ - recipient = parse_extract_address(recipient, &errmess, &start, &end, - &recipient_domain, FALSE); - /* rfc821_domains = FALSE; << no longer needed */ - - if (recipient == NULL) - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); - - /* If the recipient address is unqualified, qualify it if permitted. Then - add it to the list of recipients. */ - - if (recipient_domain == 0) - { - if (allow_unqualified_recipient) - { - DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", - recipient); - recipient = rewrite_address_qualify(recipient, TRUE); - } - /* The function moan_smtp_batch() does not return. */ - else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain " - "a domain"); - } - receive_add_recipient(recipient, -1); - break; + receive_add_recipient(recipient, -1); + break; /* The DATA command is legal only if it follows successful MAIL FROM @@ -1276,22 +1923,20 @@ while (done <= 0) command is encountered. */ case DATA_CMD: - if (sender_address == NULL || recipients_count <= 0) - { - /* The function moan_smtp_batch() does not return. */ - if (sender_address == NULL) - moan_smtp_batch(smtp_cmd_buffer, - "503 MAIL FROM: command must precede DATA"); + if (!sender_address || recipients_count <= 0) + /* The function moan_smtp_batch() does not return. */ + if (!sender_address) + moan_smtp_batch(smtp_cmd_buffer, + "503 MAIL FROM: command must precede DATA"); + else + moan_smtp_batch(smtp_cmd_buffer, + "503 RCPT TO: must precede DATA"); else - moan_smtp_batch(smtp_cmd_buffer, - "503 RCPT TO: must precede DATA"); - } - else - { - done = 3; /* DATA successfully achieved */ - message_ended = END_NOTENDED; /* Indicate in middle of message */ - } - break; + { + done = 3; /* DATA successfully achieved */ + message_ended = END_NOTENDED; /* Indicate in middle of message */ + } + break; /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */ @@ -1301,32 +1946,36 @@ while (done <= 0) case HELP_CMD: case NOOP_CMD: case ETRN_CMD: - bsmtp_transaction_linecount = receive_linecount; - break; +#ifdef EXPERIMENTAL_WELLKNOWN + case WELLKNOWN_CMD: +#endif + bsmtp_transaction_linecount = receive_linecount; + break; - case EOF_CMD: case QUIT_CMD: - done = 2; - break; + f.smtp_in_quit = TRUE; + case EOF_CMD: + done = 2; + break; case BADARG_CMD: - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data"); - break; + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data"); + break; case BADCHAR_CMD: - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command"); - break; + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command"); + break; default: - /* The function moan_smtp_batch() does not return. */ - moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized"); - break; + /* The function moan_smtp_batch() does not return. */ + moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized"); + break; } } @@ -1336,6 +1985,92 @@ return done - 2; /* Convert yield values */ +#ifndef DISABLE_TLS +static BOOL +smtp_log_tls_fail(const uschar * errstr) +{ +const uschar * conn_info = smtp_get_connection_info(); + +if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5; +/* I'd like to get separated H= here, but too hard for now */ + +log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr); +return FALSE; +} +#endif + + + + +#ifdef TCP_FASTOPEN +static void +tfo_in_check(void) +{ +# ifdef __FreeBSD__ +int is_fastopen; +socklen_t len = sizeof(is_fastopen); + +/* The tinfo TCPOPT_FAST_OPEN bit seems unreliable, and we don't see state +TCP_SYN_RCV (as of 12.1) so no idea about data-use. */ + +if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_FASTOPEN, &is_fastopen, &len) == 0) + { + if (is_fastopen) + { + DEBUG(D_receive) + debug_printf("TFO mode connection (TCP_FASTOPEN getsockopt)\n"); + f.tcp_in_fastopen = TRUE; + } + } +else DEBUG(D_receive) + debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno)); + +# elif defined(TCP_INFO) +struct tcp_info tinfo; +socklen_t len = sizeof(tinfo); + +if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0) +# ifdef TCPI_OPT_SYN_DATA /* FreeBSD 11,12 do not seem to have this yet */ + if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) + { + DEBUG(D_receive) + debug_printf("TFO mode connection (ACKd data-on-SYN)\n"); + f.tcp_in_fastopen_data = f.tcp_in_fastopen = TRUE; + } + else +# endif + if (tinfo.tcpi_state == TCP_SYN_RECV) /* Not seen on FreeBSD 12.1 */ + { + DEBUG(D_receive) + debug_printf("TFO mode connection (state TCP_SYN_RECV)\n"); + f.tcp_in_fastopen = TRUE; + } +else DEBUG(D_receive) + debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno)); +# endif +} +#endif + + +static void +log_connect_tls_drop(const uschar * what, const uschar * log_msg) +{ +if (log_reject_target) + { + gstring * g = s_tlslog(NULL); + uschar * tls = string_from_gstring(g); + + log_write(L_connection_reject, + log_reject_target, "%s%s%s dropped by %s%s%s", + LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"", + host_and_ident(TRUE), + tls ? tls : US"", + what, + log_msg ? US": " : US"", log_msg); + } +} + + /************************************************* * Start an SMTP session * *************************************************/ @@ -1352,62 +2087,66 @@ Returns: FALSE if the session can not continue; something has BOOL smtp_start_session(void) { -int size = 256; -int ptr, esclen; +int esclen; uschar *user_msg, *log_msg; uschar *code, *esc; -uschar *p, *s, *ss; +uschar *p, *s; +gstring * ss; -smtp_connection_start = time(NULL); +gettimeofday(&smtp_connection_start, NULL); for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++) smtp_connection_had[smtp_ch_index] = SCH_NONE; smtp_ch_index = 0; /* Default values for certain variables */ -helo_seen = esmtp = helo_accept_junk = FALSE; +fl.helo_seen = fl.esmtp = fl.helo_accept_junk = FALSE; smtp_mailcmd_count = 0; count_nonmail = TRUE_UNSET; synprot_error_count = unknown_command_count = nonmail_command_count = 0; smtp_delay_mail = smtp_rlm_base; -auth_advertised = FALSE; -pipelining_advertised = FALSE; -pipelining_enable = TRUE; +fl.auth_advertised = FALSE; +f.smtp_in_pipelining_advertised = f.smtp_in_pipelining_used = FALSE; +f.pipelining_enable = TRUE; sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; -smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */ - -memset(sender_host_cache, 0, sizeof(sender_host_cache)); +fl.smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */ /* If receiving by -bs from a trusted user, or testing with -bh, we allow authentication settings from -oMaa to remain in force. */ -if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL; +if (!host_checking && !f.sender_host_notsocket) + sender_host_auth_pubname = sender_host_authenticated = NULL; authenticated_by = NULL; -#ifdef SUPPORT_TLS -tls_cipher = tls_peerdn = NULL; -tls_advertised = FALSE; +#ifndef DISABLE_TLS +tls_in.ver = tls_in.cipher = tls_in.peerdn = NULL; +tls_in.ourcert = tls_in.peercert = NULL; +tls_in.sni = NULL; +tls_in.ocsp = OCSP_NOT_REQ; +fl.tls_advertised = FALSE; +#endif +fl.dsn_advertised = FALSE; +#ifdef SUPPORT_I18N +fl.smtputf8_advertised = FALSE; #endif /* Reset ACL connection variables */ acl_var_c = NULL; -/* Allow for trailing 0 in the command and data buffers. */ +/* Allow for trailing 0 in the command and data buffers. Tainted. */ + +smtp_cmd_buffer = store_get_perm(2*SMTP_CMD_BUFFER_SIZE + 2, GET_TAINTED); -smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2); -if (smtp_cmd_buffer == NULL) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, - "malloc() failed for SMTP command buffer"); smtp_cmd_buffer[0] = 0; -smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1; +smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1; /* For batched input, the protocol setting can be overridden from the command line by a trusted caller. */ if (smtp_batched_input) { - if (received_protocol == NULL) received_protocol = US"local-bsmtp"; + if (!received_protocol) received_protocol = US"local-bsmtp"; } /* For non-batched SMTP input, the protocol setting is forced here. It will be @@ -1415,26 +2154,30 @@ reset later if any of EHLO/AUTH/STARTTLS are received. */ else received_protocol = - protocols[pnormal] + ((sender_host_address != NULL)? pnlocal : 0); + (sender_host_address ? protocols : protocols_local) [pnormal]; /* Set up the buffer for inputting using direct read() calls, and arrange to call the local functions instead of the standard C ones. */ -smtp_inbuffer = (uschar *)malloc(in_buffer_size); -if (smtp_inbuffer == NULL) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); +smtp_buf_init(); + receive_getc = smtp_getc; +receive_getbuf = smtp_getbuf; +receive_get_cache = smtp_get_cache; +receive_hasc = smtp_hasc; receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; -receive_smtp_buffered = smtp_buffered; -smtp_inptr = smtp_inend = smtp_inbuffer; -smtp_had_eof = smtp_had_error = 0; +lwr_receive_getc = NULL; +lwr_receive_getbuf = NULL; +lwr_receive_hasc = NULL; +lwr_receive_ungetc = NULL; /* Set up the message size limit; this may be host-specific */ +GET_OPTION("message_size_limit"); thismessage_size_limit = expand_string_integer(message_size_limit, TRUE); -if (expand_string_message != NULL) +if (expand_string_message) { if (thismessage_size_limit == -1) log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: " @@ -1456,7 +2199,7 @@ the flag sender_host_notsocket is used to suppress it. If smtp_accept_max and smtp_accept_reserve are set, keep some connections in reserve for certain hosts and/or networks. */ -if (!sender_host_unknown) +if (!f.sender_host_unknown) { int rc; BOOL reserved_host = FALSE; @@ -1486,34 +2229,34 @@ if (!sender_host_unknown) How to do this properly in IPv6 is not yet known. */ - #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS) - - #ifdef GLIBC_IP_OPTIONS - #if (!defined __GLIBC__) || (__GLIBC__ < 2) - #define OPTSTYLE 1 - #else - #define OPTSTYLE 2 - #endif - #elif defined DARWIN_IP_OPTIONS - #define OPTSTYLE 2 - #else - #define OPTSTYLE 3 - #endif - - if (!host_checking && !sender_host_notsocket) +#if !HAVE_IPV6 && !defined(NO_IP_OPTIONS) + +# ifdef GLIBC_IP_OPTIONS +# if (!defined __GLIBC__) || (__GLIBC__ < 2) +# define OPTSTYLE 1 +# else +# define OPTSTYLE 2 +# endif +# elif defined DARWIN_IP_OPTIONS +# define OPTSTYLE 2 +# else +# define OPTSTYLE 3 +# endif + + if (!host_checking && !f.sender_host_notsocket) { - #if OPTSTYLE == 1 +# if OPTSTYLE == 1 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN; - struct ip_options *ipopt = store_get(optlen); - #elif OPTSTYLE == 2 + struct ip_options *ipopt = store_get(optlen, GET_UNTAINTED); +# elif OPTSTYLE == 2 struct ip_opts ipoptblock; struct ip_opts *ipopt = &ipoptblock; EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); - #else +# else struct ipoption ipoptblock; struct ipoption *ipopt = &ipoptblock; EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); - #endif +# endif /* Occasional genuine failures of getsockopt() have been seen - for example, "reset by peer". Therefore, just log and give up on this @@ -1524,14 +2267,14 @@ if (!sender_host_unknown) DEBUG(D_receive) debug_printf("checking for IP options\n"); - if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt), + if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt), &optlen) < 0) { if (errno != ENOPROTOOPT) { log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s", host_and_ident(FALSE), strerror(errno)); - smtp_printf("451 SMTP service not available\r\n"); + smtp_printf("451 SMTP service not available\r\n", SP_NO_MORE); return FALSE; } } @@ -1543,90 +2286,89 @@ if (!sender_host_unknown) else if (optlen > 0) { - uschar *p = big_buffer; - uschar *pend = big_buffer + big_buffer_size; - uschar *opt, *adptr; + uschar * p = big_buffer; + uschar * pend = big_buffer + big_buffer_size; + uschar * adptr; int optcount; struct in_addr addr; - #if OPTSTYLE == 1 - uschar *optstart = (uschar *)(ipopt->__data); - #elif OPTSTYLE == 2 - uschar *optstart = (uschar *)(ipopt->ip_opts); - #else - uschar *optstart = (uschar *)(ipopt->ipopt_list); - #endif +# if OPTSTYLE == 1 + uschar * optstart = US (ipopt->__data); +# elif OPTSTYLE == 2 + uschar * optstart = US (ipopt->ip_opts); +# else + uschar * optstart = US (ipopt->ipopt_list); +# endif DEBUG(D_receive) debug_printf("IP options exist\n"); Ustrcpy(p, "IP options on incoming call:"); p += Ustrlen(p); - for (opt = optstart; opt != NULL && - opt < (uschar *)(ipopt) + optlen;) - { + for (uschar * opt = optstart; opt && opt < US (ipopt) + optlen; ) switch (*opt) { case IPOPT_EOL: - opt = NULL; - break; + opt = NULL; + break; case IPOPT_NOP: - opt++; - break; + opt++; + break; case IPOPT_SSRR: case IPOPT_LSRR: - if (!string_format(p, pend-p, " %s [@%s", - (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", - #if OPTSTYLE == 1 - inet_ntoa(*((struct in_addr *)(&(ipopt->faddr)))))) - #elif OPTSTYLE == 2 - inet_ntoa(ipopt->ip_dst))) - #else - inet_ntoa(ipopt->ipopt_dst))) - #endif - { - opt = NULL; - break; - } - - p += Ustrlen(p); - optcount = (opt[1] - 3) / sizeof(struct in_addr); - adptr = opt + 3; - while (optcount-- > 0) - { - memcpy(&addr, adptr, sizeof(addr)); - if (!string_format(p, pend - p - 1, "%s%s", - (optcount == 0)? ":" : "@", inet_ntoa(addr))) - { - opt = NULL; - break; - } - p += Ustrlen(p); - adptr += sizeof(struct in_addr); - } - *p++ = ']'; - opt += opt[1]; - break; + if (! +# if OPTSTYLE == 1 + string_format(p, pend-p, " %s [@%s", + (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", + inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))) +# elif OPTSTYLE == 2 + string_format(p, pend-p, " %s [@%s", + (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", + inet_ntoa(ipopt->ip_dst)) +# else + string_format(p, pend-p, " %s [@%s", + (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", + inet_ntoa(ipopt->ipopt_dst)) +# endif + ) + { + opt = NULL; + break; + } + + p += Ustrlen(p); + optcount = (opt[1] - 3) / sizeof(struct in_addr); + adptr = opt + 3; + while (optcount-- > 0) + { + memcpy(&addr, adptr, sizeof(addr)); + if (!string_format(p, pend - p - 1, "%s%s", + (optcount == 0)? ":" : "@", inet_ntoa(addr))) + { + opt = NULL; + break; + } + p += Ustrlen(p); + adptr += sizeof(struct in_addr); + } + *p++ = ']'; + opt += opt[1]; + break; default: - { - int i; - if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; } - Ustrcat(p, "[ "); - p += 2; - for (i = 0; i < opt[1]; i++) - { - sprintf(CS p, "%2.2x ", opt[i]); - p += 3; - } - *p++ = ']'; - } - opt += opt[1]; - break; + { + if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; } + Ustrcat(p, "[ "); + p += 2; + for (int i = 0; i < opt[1]; i++) + p += sprintf(CS p, "%2.2x ", opt[i]); + *p++ = ']'; + } + opt += opt[1]; + break; } - } *p = 0; log_write(0, LOG_MAIN, "%s", big_buffer); @@ -1636,7 +2378,7 @@ if (!sender_host_unknown) log_write(0, LOG_MAIN|LOG_REJECT, "connection from %s refused (IP options)", host_and_ident(FALSE)); - smtp_printf("554 SMTP service not available\r\n"); + smtp_printf("554 SMTP service not available\r\n", SP_NO_MORE); return FALSE; } @@ -1644,13 +2386,13 @@ if (!sender_host_unknown) else DEBUG(D_receive) debug_printf("no IP options found\n"); } - #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */ +#endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */ /* Set keep-alive in socket options. The option is on by default. This setting is an attempt to get rid of some hanging connections that stick in read() when the remote end (usually a dialup) goes away. */ - if (smtp_accept_keepalive && !sender_host_notsocket) + if (smtp_accept_keepalive && !f.sender_host_notsocket) ip_keepalive(fileno(smtp_out), sender_host_address, FALSE); /* If the current host matches host_lookup, set the name by doing a @@ -1669,14 +2411,18 @@ if (!sender_host_unknown) set_process_info("handling incoming connection from %s", host_and_ident(FALSE)); - /* Start up TLS if tls_on_connect is set. This is for supporting the legacy - smtps port for use with older style SSL MTAs. */ + /* Expand smtp_receive_timeout, if needed */ - #ifdef SUPPORT_TLS - if (tls_on_connect && - tls_server_start(tls_require_ciphers) != OK) - return FALSE; - #endif + if (smtp_receive_timeout_s) + { + uschar * exp; + if ( !(exp = expand_string(smtp_receive_timeout_s)) + || !(*exp) + || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0 + ) + log_write(0, LOG_MAIN|LOG_PANIC, + "bad value for smtp_receive_timeout: '%s'", exp ? exp : US""); + } /* Test for explicit connection rejection */ @@ -1684,7 +2430,10 @@ if (!sender_host_unknown) { log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection " "from %s (host_reject_connection)", host_and_ident(FALSE)); - smtp_printf("554 SMTP service not available\r\n"); +#ifndef DISABLE_TLS + if (!tls_in.on_connect) +#endif + smtp_printf("554 SMTP service not available\r\n", SP_NO_MORE); return FALSE; } @@ -1697,19 +2446,17 @@ if (!sender_host_unknown) value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does not exist). */ - #ifdef USE_TCP_WRAPPERS +#ifdef USE_TCP_WRAPPERS errno = 0; - tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name); - if (tcp_wrappers_name == NULL) - { + if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name))) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" " "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name), expand_string_message); - } + if (!hosts_ctl(tcp_wrappers_name, - (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name, - (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address, - (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident)) + sender_host_name ? CS sender_host_name : STRING_UNKNOWN, + sender_host_address ? CS sender_host_address : STRING_UNKNOWN, + sender_ident ? CS sender_ident : STRING_UNKNOWN)) { if (errno == 0 || errno == ENOENT) { @@ -1717,7 +2464,7 @@ if (!sender_host_unknown) log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection from %s " "(tcp wrappers)", host_and_ident(FALSE)); - smtp_printf("554 SMTP service not available\r\n"); + smtp_printf("554 SMTP service not available\r\n", SP_NO_MORE); } else { @@ -1727,11 +2474,11 @@ if (!sender_host_unknown) log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s " "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno); - smtp_printf("451 Temporary local problem - please try later\r\n"); + smtp_printf("451 Temporary local problem - please try later\r\n", SP_NO_MORE); } return FALSE; } - #endif +#endif /* Check for reserved slots. The value of smtp_accept_count has already been incremented to include this process. */ @@ -1747,7 +2494,7 @@ if (!sender_host_unknown) host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max, smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : ""); smtp_printf("421 %s: Too many concurrent SMTP connections; " - "please try again later\r\n", smtp_active_hostname); + "please try again later\r\n", SP_NO_MORE, smtp_active_hostname); return FALSE; } reserved_host = TRUE; @@ -1768,7 +2515,7 @@ if (!sender_host_unknown) LOG_MAIN, "temporarily refused connection from %s: not in " "reserve list and load average = %.2f", host_and_ident(FALSE), (double)load_average/1000.0); - smtp_printf("421 %s: Too much load; please try again later\r\n", + smtp_printf("421 %s: Too much load; please try again later\r\n", SP_NO_MORE, smtp_active_hostname); return FALSE; } @@ -1779,44 +2526,82 @@ if (!sender_host_unknown) addresses in the headers. For a site that permits no qualification, this won't take long, however. */ - allow_unqualified_sender = + f.allow_unqualified_sender = verify_check_host(&sender_unqualified_hosts) == OK; - allow_unqualified_recipient = + f.allow_unqualified_recipient = verify_check_host(&recipient_unqualified_hosts) == OK; /* Determine whether HELO/EHLO is required for this host. The requirement can be hard or soft. */ - helo_required = verify_check_host(&helo_verify_hosts) == OK; - if (!helo_required) - helo_verify = verify_check_host(&helo_try_verify_hosts) == OK; + fl.helo_verify_required = verify_check_host(&helo_verify_hosts) == OK; + if (!fl.helo_verify_required) + fl.helo_verify = verify_check_host(&helo_try_verify_hosts) == OK; /* Determine whether this hosts is permitted to send syntactic junk after a HELO or EHLO command. */ - helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK; + fl.helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK; } +/* Expand recipients_max, if needed */ + { + uschar * rme = expand_string(recipients_max); + recipients_max_expanded = atoi(CCS rme); + } /* For batch SMTP input we are now done. */ if (smtp_batched_input) return TRUE; -/* Run the ACL if it exists */ +#if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS) || defined(EXPERIMETAL_XCLIENT) +proxy_session = FALSE; +#endif + +#ifdef SUPPORT_PROXY +/* If valid Proxy Protocol source is connecting, set up session. +Failure will not allow any SMTP function other than QUIT. */ + +f.proxy_session_failed = FALSE; +if (proxy_protocol_host()) + { + os_non_restarting_signal(SIGALRM, command_timeout_handler); + proxy_protocol_setup(); + } +#endif + +/* Run the connect ACL if it exists */ user_msg = NULL; -if (acl_smtp_connect != NULL) +GET_OPTION("acl_smtp_connect"); +if (acl_smtp_connect) { int rc; - rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg, - &log_msg); - if (rc != OK) + if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg, + &log_msg)) != OK) { - (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg); +#ifndef DISABLE_TLS + if (tls_in.on_connect) + log_connect_tls_drop(US"'connect' ACL", log_msg); + else +#endif + (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg); return FALSE; } } +/* Start up TLS if tls_on_connect is set. This is for supporting the legacy +smtps port for use with older style SSL MTAs. */ + +#ifndef DISABLE_TLS +if (tls_in.on_connect) + { + if (tls_server_start(&user_msg) != OK) + return smtp_log_tls_fail(user_msg); + cmd_list[CL_TLAU].is_mail_cmd = TRUE; + } +#endif + /* Output the initial message for a two-way SMTP connection. It may contain newlines, which then cause a multi-line response to be given. */ @@ -1824,30 +2609,38 @@ code = US"220"; /* Default status code */ esc = US""; /* Default extended status code */ esclen = 0; /* Length of esc */ -if (user_msg == NULL) - { - s = expand_string(smtp_banner); - if (s == NULL) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) " - "failed: %s", smtp_banner, expand_string_message); - } -else +if (user_msg) { int codelen = 3; s = user_msg; - smtp_message_code(&code, &codelen, &s, NULL); + smtp_message_code(&code, &codelen, &s, NULL, TRUE); if (codelen > 4) { esc = code + 4; esclen = codelen - 4; } } +else + { + GET_OPTION("smtp_banner"); + if (!(s = expand_string(smtp_banner))) + { + log_write(0, f.expand_string_forcedfail ? LOG_MAIN : LOG_MAIN|LOG_PANIC_DIE, + "Expansion of \"%s\" (smtp_banner) failed: %s", + smtp_banner, expand_string_message); + /* for force-fail */ + #ifndef DISABLE_TLS + if (tls_in.on_connect) tls_close(NULL, TLS_SHUTDOWN_WAIT); + #endif + return FALSE; + } + } /* Remove any terminating newlines; might as well remove trailing space too */ p = s + Ustrlen(s); while (p > s && isspace(p[-1])) p--; -*p = 0; +s = string_copyn(s, p-s); /* It seems that CC:Mail is braindead, and assumes that the greeting message is all contained in a single IP packet. The original code wrote out the @@ -1858,51 +2651,76 @@ command. Sigh. To try to avoid this, build the complete greeting message first, and output it in one fell swoop. This gives a better chance of it ending up as a single packet. */ -ss = store_get(size); -ptr = 0; +ss = string_get(256); p = s; do /* At least once, in case we have an empty string */ { int len; uschar *linebreak = Ustrchr(p, '\n'); - ss = string_cat(ss, &size, &ptr, code, 3); - if (linebreak == NULL) + ss = string_catn(ss, code, 3); + if (!linebreak) { len = Ustrlen(p); - ss = string_cat(ss, &size, &ptr, US" ", 1); + ss = string_catn(ss, US" ", 1); } else { len = linebreak - p; - ss = string_cat(ss, &size, &ptr, US"-", 1); + ss = string_catn(ss, US"-", 1); } - ss = string_cat(ss, &size, &ptr, esc, esclen); - ss = string_cat(ss, &size, &ptr, p, len); - ss = string_cat(ss, &size, &ptr, US"\r\n", 2); + ss = string_catn(ss, esc, esclen); + ss = string_catn(ss, p, len); + ss = string_catn(ss, US"\r\n", 2); p += len; - if (linebreak != NULL) p++; + if (linebreak) p++; } -while (*p != 0); - -ss[ptr] = 0; /* string_cat leaves room for this */ +while (*p); /* Before we write the banner, check that there is no input pending, unless this synchronisation check is disabled. */ +#ifndef DISABLE_PIPE_CONNECT +fl.pipe_connect_acceptable = + sender_host_address && verify_check_host(&pipe_connect_advertise_hosts) == OK; + if (!check_sync()) - { - log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol " - "synchronization error (input sent without waiting for greeting): " - "rejected connection from %s input=\"%s\"", host_and_ident(TRUE), - string_printing(smtp_inptr)); - smtp_printf("554 SMTP synchronization error\r\n"); - return FALSE; - } + if (fl.pipe_connect_acceptable) + f.smtp_in_early_pipe_used = TRUE; + else +#else +if (!check_sync()) +#endif + { + unsigned n = smtp_inend - smtp_inptr; + if (n > 128) n = 128; + + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol " + "synchronization error (input sent without waiting for greeting): " + "rejected connection from %s input=\"%s\"", host_and_ident(TRUE), + string_printing(string_copyn(smtp_inptr, n))); + smtp_printf("554 SMTP synchronization error\r\n", SP_NO_MORE); + return FALSE; + } /* Now output the banner */ +/*XXX the ehlo-resp code does its own tls/nontls bit. Maybe subroutine that? */ + +smtp_printf("%Y", +#ifndef DISABLE_PIPE_CONNECT + fl.pipe_connect_acceptable && pipeline_connect_sends(), +#else + SP_NO_MORE, +#endif + ss); + +/* Attempt to see if we sent the banner before the last ACK of the 3-way +handshake arrived. If so we must have managed a TFO. */ + +#ifdef TCP_FASTOPEN +if (sender_host_address && !f.sender_host_notsocket) tfo_in_check(); +#endif -smtp_printf("%s", ss); return TRUE; } @@ -1936,23 +2754,25 @@ synprot_error(int type, int code, uschar *data, uschar *errmess) int yield = -1; log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s", - (type == L_smtp_syntax_error)? "syntax" : "protocol", + type == L_smtp_syntax_error ? "syntax" : "protocol", string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess); if (++synprot_error_count > smtp_max_synprot_errors) { yield = 1; log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " - "syntax or protocol errors (last command was \"%s\")", - host_and_ident(FALSE), smtp_cmd_buffer); + "syntax or protocol errors (last command was \"%s\", %Y)", + host_and_ident(FALSE), string_printing(smtp_cmd_buffer), + s_connhad_log(NULL) + ); } if (code > 0) { - smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ', - (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess); + smtp_printf("%d%c%s%s%s\r\n", SP_NO_MORE, code, yield == 1 ? '-' : ' ', + data ? data : US"", data ? US": " : US"", errmess); if (yield == 1) - smtp_printf("%d Too many syntax or protocol errors\r\n", code); + smtp_printf("%d Too many syntax or protocol errors\r\n", SP_NO_MORE, code); } return yield; @@ -1962,66 +2782,29 @@ return yield; /************************************************* -* Log incomplete transactions * +* Send SMTP response, possibly multiline * *************************************************/ -/* This function is called after a transaction has been aborted by RSET, QUIT, -connection drops or other errors. It logs the envelope information received -so far in order to preserve address verification attempts. +/* There are, it seems, broken clients out there that cannot handle multiline +responses. If no_multiline_responses is TRUE (it can be set from an ACL), we +output nothing for non-final calls, and only the first line for anything else. -Argument: string to indicate what aborted the transaction -Returns: nothing -*/ - -static void -incomplete_transaction_log(uschar *what) -{ -if (sender_address == NULL || /* No transaction in progress */ - (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */ - ) return; - -/* Build list of recipients for logging */ - -if (recipients_count > 0) - { - int i; - raw_recipients = store_get(recipients_count * sizeof(uschar *)); - for (i = 0; i < recipients_count; i++) - raw_recipients[i] = recipients_list[i].address; - raw_recipients_count = recipients_count; - } - -log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS, - "%s incomplete transaction (%s)", host_and_ident(TRUE), what); -} - - - - -/************************************************* -* Send SMTP response, possibly multiline * -*************************************************/ - -/* There are, it seems, broken clients out there that cannot handle multiline -responses. If no_multiline_responses is TRUE (it can be set from an ACL), we -output nothing for non-final calls, and only the first line for anything else. - -Arguments: - code SMTP code, may involve extended status codes - codelen length of smtp code; if > 4 there's an ESC - final FALSE if the last line isn't the final line - msg message text, possibly containing newlines - -Returns: nothing +Arguments: + code SMTP code, may involve extended status codes + codelen length of smtp code; if > 4 there's an ESC + final FALSE if the last line isn't the final line + msg message text, possibly containing newlines + +Returns: nothing */ void -smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg) +smtp_respond(uschar * code, int codelen, BOOL final, uschar * msg) { int esclen = 0; uschar *esc = US""; -if (!final && no_multiline_responses) return; +if (!final && f.no_multiline_responses) return; if (codelen > 4) { @@ -2035,37 +2818,39 @@ be tidier to have it only in one place, but when it was added, it was easier to do it that way, so as not to have to mess with the code for the RCPT command, which sometimes uses smtp_printf() and sometimes smtp_respond(). */ -if (rcpt_in_progress) +if (fl.rcpt_in_progress) { - if (rcpt_smtp_response == NULL) + if (!rcpt_smtp_response) rcpt_smtp_response = string_copy(msg); - else if (rcpt_smtp_response_same && + else if (fl.rcpt_smtp_response_same && Ustrcmp(rcpt_smtp_response, msg) != 0) - rcpt_smtp_response_same = FALSE; - rcpt_in_progress = FALSE; + fl.rcpt_smtp_response_same = FALSE; + fl.rcpt_in_progress = FALSE; } -/* Not output the message, splitting it up into multiple lines if necessary. */ +/* Now output the message, splitting it up into multiple lines if necessary. +We only handle pipelining these responses as far as nonfinal/final groups, +not the whole MAIL/RCPT/DATA response set. */ for (;;) { uschar *nl = Ustrchr(msg, '\n'); - if (nl == NULL) + if (!nl) { - smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg); + smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg); return; } - else if (nl[1] == 0 || no_multiline_responses) + else if (nl[1] == 0 || f.no_multiline_responses) { - smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc, + smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc, (int)(nl - msg), msg); return; } else { - smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg); + smtp_printf("%.3s-%.*s%.*s\r\n", SP_MORE, code, esclen, esc, (int)(nl - msg), msg); msg = nl + 1; - while (isspace(*msg)) msg++; + Uskip_whitespace(&msg); } } } @@ -2097,35 +2882,35 @@ Arguments: codelen length of smtp code; if > 4 there's an ESC msg message text log_msg optional log message, to be adjusted with the new SMTP code + check_valid if true, verify the response code Returns: nothing */ void -smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg) +smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg, + BOOL check_valid) { -int n; -int ovector[3]; +uschar * match; +int len; -if (msg == NULL || *msg == NULL) return; - -n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0, - PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int)); -if (n < 0) return; +if (!msg || !*msg || !regex_match(regex_smtp_code, *msg, -1, &match)) + return; -if ((*msg)[0] != (*code)[0]) +len = Ustrlen(match); +if (check_valid && (*msg)[0] != (*code)[0]) { log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with " "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg); - if (log_msg != NULL && *log_msg == *msg) - *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]); + if (log_msg && *log_msg == *msg) + *log_msg = string_sprintf("%s %s", *code, *log_msg + len); } else { *code = *msg; - *codelen = ovector[1]; /* Includes final space */ + *codelen = len; /* Includes final space */ } -*msg += ovector[1]; /* Chop the code off the message */ +*msg += len; /* Chop the code off the message */ return; } @@ -2138,7 +2923,7 @@ return; /* This function is called when acl_check() fails. As well as calls from within this module, it is called from receive.c for an ACL after DATA. It sorts out -logging the incident, and sets up the error response. A message containing +logging the incident, and sends the error response. A message containing newlines is turned into a multiline SMTP response, but for logging, only the first line is used. @@ -2148,18 +2933,19 @@ defaults disabled in Exim. However, discussion in connection with RFC 821bis (aka RFC 2821) has concluded that the response should be 252 in the disabled state, because there are broken clients that try VRFY before RCPT. A 5xx response should be given only when the address is positively known to be -undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH, -503. +undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides +no explicit code, but if there is one we let it know best. +Also, for ETRN, 458 is given on refusal, and for AUTH, 503. From Exim 4.63, it is possible to override the response code details by providing a suitable response code string at the start of the message provided in user_msg. The code's first digit is checked for validity. Arguments: - where where the ACL was called from - rc the failure code - user_msg a message that can be included in an SMTP response - log_msg a message for logging + where where the ACL was called from + rc the failure code + user_msg a message that can be included in an SMTP response + log_msg a message for logging Returns: 0 in most cases 2 if the failure code was FAIL_DROP, in which case the @@ -2168,29 +2954,22 @@ Returns: 0 in most cases */ int -smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg) +smtp_handle_acl_fail(int where, int rc, uschar * user_msg, uschar * log_msg) { BOOL drop = rc == FAIL_DROP; int codelen = 3; uschar *smtp_code; uschar *lognl; uschar *sender_info = US""; -uschar *what = -#ifdef WITH_CONTENT_SCAN - (where == ACL_WHERE_MIME)? US"during MIME ACL checks" : -#endif - (where == ACL_WHERE_PREDATA)? US"DATA" : - (where == ACL_WHERE_DATA)? US"after DATA" : - (smtp_cmd_data == NULL)? - string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) : - string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data); +uschar *what; if (drop) rc = FAIL; /* Set the default SMTP code, and allow a user message to change it. */ -smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where]; -smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg); +smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451"; +smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg, + where != ACL_WHERE_VRFY); /* We used to have sender_address here; however, there was a bug that was not updating sender_address after a rewrite during a verify. When this bug was @@ -2198,19 +2977,45 @@ fixed, sender_address at this point became the rewritten address. I'm not sure this is what should be logged, so I've changed to logging the unrewritten address to retain backward compatibility. */ -#ifndef WITH_CONTENT_SCAN -if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA) -#else -if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME) +switch (where) + { +#ifdef WITH_CONTENT_SCAN + case ACL_WHERE_MIME: what = US"during MIME ACL checks"; break; +#endif + case ACL_WHERE_PREDATA: what = US"DATA"; break; + case ACL_WHERE_DATA: what = US"after DATA"; break; +#ifndef DISABLE_PRDR + case ACL_WHERE_PRDR: what = US"after DATA PRDR"; break; #endif + default: + { + uschar * place = smtp_cmd_data ? smtp_cmd_data : US"in \"connect\" ACL"; + int lim = 100; + + if (where == ACL_WHERE_AUTH) /* avoid logging auth creds */ + { + uschar * s = smtp_cmd_data; + Uskip_nonwhite(&s); + lim = s - smtp_cmd_data; /* atop after method */ + } + what = string_sprintf("%s %.*s", acl_wherenames[where], lim, place); + } + } +switch (where) { - sender_info = string_sprintf("F=<%s>%s%s%s%s ", - sender_address_unrewritten ? sender_address_unrewritten : sender_address, - sender_host_authenticated ? US" A=" : US"", - sender_host_authenticated ? sender_host_authenticated : US"", - sender_host_authenticated && authenticated_id ? US":" : US"", - sender_host_authenticated && authenticated_id ? authenticated_id : US"" - ); + case ACL_WHERE_RCPT: + case ACL_WHERE_DATA: +#ifdef WITH_CONTENT_SCAN + case ACL_WHERE_MIME: +#endif + sender_info = string_sprintf("F=<%s>%s%s%s%s ", + sender_address_unrewritten ? sender_address_unrewritten : sender_address, + sender_host_authenticated ? US" A=" : US"", + sender_host_authenticated ? sender_host_authenticated : US"", + sender_host_authenticated && authenticated_id ? US":" : US"", + sender_host_authenticated && authenticated_id ? authenticated_id : US"" + ); + break; } /* If there's been a sender verification failure with a specific message, and @@ -2218,15 +3023,15 @@ we have not sent a response about it yet, do so now, as a preliminary line for failures, but not defers. However, always log it for defer, and log it for fail unless the sender_verify_fail log selector has been turned off. */ -if (sender_verified_failed != NULL && +if (sender_verified_failed && !testflag(sender_verified_failed, af_sverify_told)) { - BOOL save_rcpt_in_progress = rcpt_in_progress; - rcpt_in_progress = FALSE; /* So as not to treat these as the error */ + BOOL save_rcpt_in_progress = fl.rcpt_in_progress; + fl.rcpt_in_progress = FALSE; /* So as not to treat these as the error */ setflag(sender_verified_failed, af_sverify_told); - if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0) + if (rc != FAIL || LOGGING(sender_verify_fail)) log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s", host_and_ident(TRUE), ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail", @@ -2234,8 +3039,8 @@ if (sender_verified_failed != NULL && (sender_verified_failed->message == NULL)? US"" : string_sprintf(": %s", sender_verified_failed->message)); - if (rc == FAIL && sender_verified_failed->user_message != NULL) - smtp_respond(smtp_code, codelen, FALSE, string_sprintf( + if (rc == FAIL && sender_verified_failed->user_message) + smtp_respond(smtp_code, codelen, SR_NOT_FINAL, string_sprintf( testflag(sender_verified_failed, af_verify_pmfail)? "Postmaster verification failed while checking <%s>\n%s\n" "Several RFCs state that you are required to have a postmaster\n" @@ -2254,21 +3059,21 @@ if (sender_verified_failed != NULL && sender_verified_failed->address, sender_verified_failed->user_message)); - rcpt_in_progress = save_rcpt_in_progress; + fl.rcpt_in_progress = save_rcpt_in_progress; } /* Sort out text for logging */ -log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg); -lognl = Ustrchr(log_msg, '\n'); -if (lognl != NULL) *lognl = 0; +log_msg = log_msg ? string_sprintf(": %s", log_msg) : US""; +if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0; /* Send permanent failure response to the command, but the code used isn't always a 5xx one - see comments at the start of this function. If the original rc was FAIL_DROP we drop the connection and yield 2. */ -if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)? - US"Administrative prohibition" : user_msg); +if (rc == FAIL) + smtp_respond(smtp_code, codelen, SR_FINAL, + user_msg ? user_msg : US"Administrative prohibition"); /* Send temporary failure response to the command. Don't give any details, unless acl_temp_details is set. This is TRUE for a callout defer, a "defer" @@ -2279,42 +3084,66 @@ interactions between temp_details and return_error_details. One day it should be re-implemented in a tidier fashion. */ else - { - if (acl_temp_details && user_msg != NULL) + if (f.acl_temp_details && user_msg) { - if (smtp_return_error_details && - sender_verified_failed != NULL && - sender_verified_failed->message != NULL) - { - smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message); - } - smtp_respond(smtp_code, codelen, TRUE, user_msg); + if ( smtp_return_error_details + && sender_verified_failed + && sender_verified_failed->message + ) + smtp_respond(smtp_code, codelen, SR_NOT_FINAL, sender_verified_failed->message); + + smtp_respond(smtp_code, codelen, SR_FINAL, user_msg); } else - smtp_respond(smtp_code, codelen, TRUE, + smtp_respond(smtp_code, codelen, SR_FINAL, US"Temporary local problem - please try later"); - } /* Log the incident to the logs that are specified by log_reject_target (default main, reject). This can be empty to suppress logging of rejections. If the connection is not forcibly to be dropped, return 0. Otherwise, log why it is closing if required and return 2. */ -if (log_reject_target != 0) - log_write(0, log_reject_target, "%s %s%srejected %s%s", +if (log_reject_target) + { +#ifndef DISABLE_TLS + gstring * g = s_tlslog(NULL); + uschar * tls = string_from_gstring(g); + if (!tls) tls = US""; +#else + uschar * tls = US""; +#endif + log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0, + log_reject_target, "%s%s%s %s%srejected %s%s", + LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"", host_and_ident(TRUE), - sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg); + tls, + sender_info, + rc == FAIL ? US"" : US"temporarily ", + what, log_msg); + } if (!drop) return 0; -log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL", - smtp_get_connection_info()); +log_close_event(US"by DROP in ACL"); /* Run the not-quit ACL, but without any custom messages. This should not be a problem, because we get here only if some other ACL has issued "drop", and in that case, *its* custom messages will have been used above. */ smtp_notquit_exit(US"acl-drop", NULL, NULL); + +/* An overenthusiastic fail2ban/iptables implimentation has been seen to result +in the TCP conn staying open, and retrying, despite this process exiting. A +malicious client could possibly do the same, tying up server netowrking +resources. Close the socket explicitly to try to avoid that (there's a note in +the Linux socket(7) manpage, SO_LINGER para, to the effect that exim() without +close() results in the socket always lingering). */ + +(void) poll_one_fd(fileno(smtp_in), POLLIN, 200); +DEBUG(D_any) debug_printf_indent("SMTP(close)>>\n"); +(void) fclose(smtp_in); +(void) fclose(smtp_out); + return 2; } @@ -2335,7 +3164,7 @@ the ACL that obeyed "drop" has already supplied the custom message, and NULL is passed to this function. In case things go wrong while processing this function, causing an error that -may re-enter this funtion, there is a recursion check. +may re-enter this function, there is a recursion check. Arguments: reason What $smtp_notquit_reason will be set to in the ACL; @@ -2353,47 +3182,48 @@ int rc; uschar *user_msg = NULL; uschar *log_msg = NULL; -/* Check for recursive acll */ +/* Check for recursive call */ -if (smtp_exit_function_called) +if (fl.smtp_exit_function_called) { log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)", reason); return; } -smtp_exit_function_called = TRUE; +fl.smtp_exit_function_called = TRUE; /* Call the not-QUIT ACL, if there is one, unless no reason is given. */ -if (acl_smtp_notquit != NULL && reason != NULL) +GET_OPTION("acl_smtp_notquit"); +if (acl_smtp_notquit && reason) { smtp_notquit_reason = reason; - rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg, - &log_msg); - if (rc == ERROR) + if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg, + &log_msg)) == ERROR) log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s", log_msg); } +/* If the connection was dropped, we certainly are no longer talking TLS */ +tls_in.active.sock = -1; + /* Write an SMTP response if we are expected to give one. As the default -responses are all internal, they should always fit in the buffer, but code a -warning, just in case. Note that string_vformat() still leaves a complete -string, even if it is incomplete. */ +responses are all internal, they should be reasonable size. */ -if (code != NULL && defaultrespond != NULL) +if (code && defaultrespond) { - if (user_msg == NULL) + if (user_msg) + smtp_respond(code, 3, SR_FINAL, user_msg); + else { - uschar buffer[128]; + gstring * g; va_list ap; + va_start(ap, defaultrespond); - if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap)) - log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()"); - smtp_printf("%s %s\r\n", code, buffer); + g = string_vformat(NULL, SVFMT_EXTEND|SVFMT_REBUFFER, CS defaultrespond, ap); va_end(ap); + smtp_printf("%s %Y\r\n", SP_NO_MORE, code, g); } - else - smtp_respond(code, 3, TRUE, user_msg); mac_smtp_fflush(); } } @@ -2438,27 +3268,27 @@ if (sender_helo_name == NULL) else if (sender_host_address == NULL) { HDEBUG(D_receive) debug_printf("no client IP address: assume success\n"); - helo_verified = TRUE; + f.helo_verified = TRUE; } /* Deal with the more common case when there is a sending IP address */ else if (sender_helo_name[0] == '[') { - helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address, + f.helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address, Ustrlen(sender_host_address)) == 0; - #if HAVE_IPV6 - if (!helo_verified) +#if HAVE_IPV6 + if (!f.helo_verified) { if (strncmpic(sender_host_address, US"::ffff:", 7) == 0) - helo_verified = Ustrncmp(sender_helo_name + 1, + f.helo_verified = Ustrncmp(sender_helo_name + 1, sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0; } - #endif +#endif HDEBUG(D_receive) - { if (helo_verified) debug_printf("matched host address\n"); } + { if (f.helo_verified) debug_printf("matched host address\n"); } } /* Do a reverse lookup if one hasn't already given a positive or negative @@ -2472,63 +3302,56 @@ else /* If a host name is known, check it and all its aliases. */ - if (sender_host_name != NULL) - { - helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0; - - if (helo_verified) + if (sender_host_name) + if ((f.helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0)) { + sender_helo_dnssec = sender_host_dnssec; HDEBUG(D_receive) debug_printf("matched host name\n"); } else { uschar **aliases = sender_host_aliases; - while (*aliases != NULL) - { - helo_verified = strcmpic(*aliases++, sender_helo_name) == 0; - if (helo_verified) break; - } - HDEBUG(D_receive) - { - if (helo_verified) + while (*aliases) + if ((f.helo_verified = strcmpic(*aliases++, sender_helo_name) == 0)) + { + sender_helo_dnssec = sender_host_dnssec; + break; + } + + HDEBUG(D_receive) if (f.helo_verified) debug_printf("matched alias %s\n", *(--aliases)); - } } - } /* Final attempt: try a forward lookup of the helo name */ - if (!helo_verified) + if (!f.helo_verified) { int rc; - host_item h; - h.name = sender_helo_name; - h.address = NULL; - h.mx = MX_NONE; - h.next = NULL; + host_item h = + {.name = sender_helo_name, .address = NULL, .mx = MX_NONE, .next = NULL}; + dnssec_domains d = + {.request = US"*", .require = US""}; + HDEBUG(D_receive) debug_printf("getting IP address for %s\n", sender_helo_name); - rc = host_find_byname(&h, NULL, 0, NULL, TRUE); + rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A | HOST_FIND_BY_AAAA, + NULL, NULL, NULL, &d, NULL, NULL); if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) - { - host_item *hh = &h; - while (hh != NULL) - { + for (host_item * hh = &h; hh; hh = hh->next) if (Ustrcmp(hh->address, sender_host_address) == 0) { - helo_verified = TRUE; + f.helo_verified = TRUE; + if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE; HDEBUG(D_receive) - debug_printf("IP address for %s matches calling address\n", - sender_helo_name); + debug_printf("IP address for %s matches calling address\n" + "Forward DNS security status: %sverified\n", + sender_helo_name, sender_helo_dnssec ? "" : "un"); break; } - hh = hh->next; - } - } } } -if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */ +if (!f.helo_verified) f.helo_verify_failed = TRUE; /* We've tried ... */ return yield; } @@ -2555,12 +3378,216 @@ static void smtp_user_msg(uschar *code, uschar *user_msg) { int len = 3; -smtp_message_code(&code, &len, &user_msg, NULL); -smtp_respond(code, len, TRUE, user_msg); +smtp_message_code(&code, &len, &user_msg, NULL, TRUE); +smtp_respond(code, len, SR_FINAL, user_msg); +} + + + +static int +smtp_in_auth(auth_instance *au, uschar ** smtp_resp, uschar ** errmsg) +{ +const uschar *set_id = NULL; +int rc; + +/* Set up globals for error messages */ + +authenticator_name = au->name; +driver_srcfile = au->srcfile; +driver_srcline = au->srcline; + +/* Run the checking code, passing the remainder of the command line as +data. Initials the $auth variables as empty. Initialize $0 empty and set +it as the only set numerical variable. The authenticator may set $auth +and also set other numeric variables. The $auth variables are preferred +nowadays; the numerical variables remain for backwards compatibility. + +Afterwards, have a go at expanding the set_id string, even if +authentication failed - for bad passwords it can be useful to log the +userid. On success, require set_id to expand and exist, and put it in +authenticated_id. Save this in permanent store, as the working store gets +reset at HELO, RSET, etc. */ + +for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; +expand_nmax = 0; +expand_nlength[0] = 0; /* $0 contains nothing */ + +rc = (au->info->servercode)(au, smtp_cmd_data); +if (au->set_id) set_id = expand_string(au->set_id); +expand_nmax = -1; /* Reset numeric variables */ +for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth */ +driver_srcfile = authenticator_name = NULL; driver_srcline = 0; + +/* The value of authenticated_id is stored in the spool file and printed in +log lines. It must not contain binary zeros or newline characters. In +normal use, it never will, but when playing around or testing, this error +can (did) happen. To guard against this, ensure that the id contains only +printing characters. */ + +if (set_id) set_id = string_printing(set_id); + +/* For the non-OK cases, set up additional logging data if set_id +is not empty. */ + +if (rc != OK) + set_id = set_id && *set_id + ? string_sprintf(" (set_id=%s)", set_id) : US""; + +/* Switch on the result */ + +switch(rc) + { + case OK: + if (!au->set_id || set_id) /* Complete success */ + { + if (set_id) authenticated_id = string_copy_perm(set_id, TRUE); + sender_host_authenticated = au->name; + sender_host_auth_pubname = au->public_name; + authentication_failed = FALSE; + authenticated_fail_id = NULL; /* Impossible to already be set? */ + + received_protocol = + (sender_host_address ? protocols : protocols_local) + [pextend + pauthed + (tls_in.active.sock >= 0 ? pcrpted:0)]; + *smtp_resp = *errmsg = US"235 Authentication succeeded"; + authenticated_by = au; + break; + } + + /* Authentication succeeded, but we failed to expand the set_id string. + Treat this as a temporary error. */ + + auth_defer_msg = expand_string_message; + /* Fall through */ + + case DEFER: + if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE); + *smtp_resp = string_sprintf("435 Unable to authenticate at present%s", + auth_defer_user_msg); + *errmsg = string_sprintf("435 Unable to authenticate at present%s: %s", + set_id, auth_defer_msg); + break; + + case BAD64: + *smtp_resp = *errmsg = US"501 Invalid base64 data"; + break; + + case CANCELLED: + *smtp_resp = *errmsg = US"501 Authentication cancelled"; + break; + + case UNEXPECTED: + *smtp_resp = *errmsg = US"553 Initial data not expected"; + break; + + case FAIL: + if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE); + *smtp_resp = US"535 Incorrect authentication data"; + *errmsg = string_sprintf("535 Incorrect authentication data%s", set_id); + break; + + default: + if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE); + *smtp_resp = US"435 Internal error"; + *errmsg = string_sprintf("435 Internal error%s: return %d from authentication " + "check", set_id, rc); + break; + } + +return rc; +} + + + + + +static int +qualify_recipient(uschar ** recipient, uschar * smtp_cmd_data, uschar * tag) +{ +int rd; +if (f.allow_unqualified_recipient || strcmpic(*recipient, US"postmaster") == 0) + { + DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", + *recipient); + rd = Ustrlen(recipient) + 1; + /* deconst ok as *recipient was not const */ + *recipient = US rewrite_address_qualify(*recipient, TRUE); + return rd; + } +smtp_printf("501 %s: recipient address must contain a domain\r\n", SP_NO_MORE, + smtp_cmd_data); +log_write(L_smtp_syntax_error, + LOG_MAIN|LOG_REJECT, "unqualified %s rejected: <%s> %s%s", + tag, *recipient, host_and_ident(TRUE), host_lookup_msg); +return 0; +} + + + + +static void +smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp) +{ +HAD(SCH_QUIT); +f.smtp_in_quit = TRUE; +incomplete_transaction_log(US"QUIT"); +GET_OPTION("acl_smtp_quit"); +if ( acl_smtp_quit + && acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp) + == ERROR) + log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", + *log_msgp); + +#ifdef EXIM_TCP_CORK +(void) setsockopt(fileno(smtp_out), IPPROTO_TCP, EXIM_TCP_CORK, US &on, sizeof(on)); +#endif + +if (*user_msgp) + smtp_respond(US"221", 3, SR_FINAL, *user_msgp); +else + smtp_printf("221 %s closing connection\r\n", SP_NO_MORE, smtp_active_hostname); + +#ifdef SERVERSIDE_CLOSE_NOWAIT +# ifndef DISABLE_TLS +tls_close(NULL, TLS_SHUTDOWN_NOWAIT); +# endif + +log_close_event(US"by QUIT"); +#else + +# ifndef DISABLE_TLS +tls_close(NULL, TLS_SHUTDOWN_WAIT); +# endif + +log_close_event(US"by QUIT"); + +/* Pause, hoping client will FIN first so that they get the TIME_WAIT. +The socket should become readble (though with no data) */ + +(void) poll_one_fd(fileno(smtp_in), POLLIN, 200); +#endif /*!SERVERSIDE_CLOSE_NOWAIT*/ } +static void +smtp_rset_handler(void) +{ +HAD(SCH_RSET); +incomplete_transaction_log(US"RSET"); +smtp_printf("250 Reset OK\r\n", SP_NO_MORE); +cmd_list[CL_RSET].is_mail_cmd = FALSE; +if (chunking_state > CHUNKING_OFFERED) + chunking_state = CHUNKING_OFFERED; +} + +static int +expand_mailmax(const uschar * s) +{ +if (!(s = expand_cstring(s))) + log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand smtp_accept_max_per_connection"); +return *s ? Uatoi(s) : 0; +} /************************************************* * Initialize for SMTP incoming message * @@ -2595,7 +3622,7 @@ BOOL toomany = FALSE; BOOL discarded = FALSE; BOOL last_was_rej_mail = FALSE; BOOL last_was_rcpt = FALSE; -void *reset_point = store_get(0); +rmark reset_point = store_mark(); DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n"); @@ -2605,30 +3632,47 @@ message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of TLS between messages (an Exim client may do this if it has messages queued up for the host). Note: we do NOT reset AUTH at this point. */ -smtp_reset(reset_point); +reset_point = smtp_reset(reset_point); message_ended = END_NOTSTARTED; -cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE; -cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE; -cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; -#ifdef SUPPORT_TLS -cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE; +chunking_state = f.chunking_offered ? CHUNKING_OFFERED : CHUNKING_NOT_OFFERED; + +cmd_list[CL_RSET].is_mail_cmd = TRUE; +cmd_list[CL_HELO].is_mail_cmd = TRUE; +cmd_list[CL_EHLO].is_mail_cmd = TRUE; +#ifndef DISABLE_TLS +cmd_list[CL_STLS].is_mail_cmd = TRUE; #endif +if (lwr_receive_getc != NULL) + { + /* This should have already happened, but if we've gotten confused, + force a reset here. */ + DEBUG(D_receive) debug_printf("WARNING: smtp_setup_msg had to restore receive functions to lowers\n"); + bdat_pop_receive_functions(); + } + /* Set the local signal handler for SIGTERM - it tries to end off tidily */ +had_command_sigterm = 0; os_non_restarting_signal(SIGTERM, command_sigterm_handler); /* Batched SMTP is handled in a different function. */ if (smtp_batched_input) return smtp_setup_batch_msg(); +#ifdef TCP_QUICKACK +if (smtp_in) /* Avoid pure-ACKs while in cmd pingpong phase */ + (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK, + US &off, sizeof(off)); +#endif + /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE value. The values are 2 larger than the required yield of the function. */ while (done <= 0) { - uschar **argv; + const uschar **argv; uschar *etrn_command; uschar *etrn_serialize_key; uschar *errmess; @@ -2636,18 +3680,69 @@ while (done <= 0) uschar *user_msg = NULL; uschar *recipient = NULL; uschar *hello = NULL; - uschar *set_id = NULL; uschar *s, *ss; BOOL was_rej_mail = FALSE; BOOL was_rcpt = FALSE; void (*oldsignal)(int); pid_t pid; int start, end, sender_domain, recipient_domain; - int ptr, size, rc; - int c, i; - auth_instance *au; + int rc; + int c; + uschar *orcpt = NULL; + int dsn_flags; + gstring * g; + +#ifdef AUTH_TLS + /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */ + if ( tls_in.active.sock >= 0 + && tls_in.peercert + && tls_in.certificate_verified + && cmd_list[CL_TLAU].is_mail_cmd + ) + { + cmd_list[CL_TLAU].is_mail_cmd = FALSE; + + for (auth_instance * au = auths; au; au = au->next) + if (strcmpic(US"tls", au->driver_name) == 0) + { + GET_OPTION("acl_smtp_auth"); + if ( acl_smtp_auth + && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, + &user_msg, &log_msg)) != OK + ) + done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg); + else + { + smtp_cmd_data = NULL; + + if (smtp_in_auth(au, &s, &ss) == OK) + { DEBUG(D_auth) debug_printf("tls auth succeeded\n"); } + else + { + DEBUG(D_auth) debug_printf("tls auth not succeeded\n"); +#ifndef DISABLE_EVENT + { + uschar * save_name = sender_host_authenticated, * logmsg; + sender_host_authenticated = au->name; + if ((logmsg = event_raise(event_action, US"auth:fail", s, NULL))) + log_write(0, LOG_MAIN, "%s", logmsg); + sender_host_authenticated = save_name; + } +#endif + } + } + break; + } + } +#endif - switch(smtp_read_command(TRUE)) + switch(smtp_read_command( +#ifndef DISABLE_PIPE_CONNECT + !fl.pipe_connect_acceptable, +#else + TRUE, +#endif + GETC_BUFFER_UNLIMITED)) { /* The AUTH command is not permitted to occur inside a transaction, and may occur successfully only once per connection. Actually, that isn't quite @@ -2664,1017 +3759,1273 @@ while (done <= 0) AUTHS will eventually hit the nonmail threshold. */ case AUTH_CMD: - HAD(SCH_AUTH); - authentication_failed = TRUE; - cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE; - - if (!auth_advertised && !allow_auth_unadvertised) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"AUTH command used when not advertised"); - break; - } - if (sender_host_authenticated != NULL) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"already authenticated"); - break; - } - if (sender_address != NULL) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"not permitted in mail transaction"); - break; - } + HAD(SCH_AUTH); + authentication_failed = TRUE; + cmd_list[CL_AUTH].is_mail_cmd = FALSE; + + if (!fl.auth_advertised && !f.allow_auth_unadvertised) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"AUTH command used when not advertised"); + break; + } + if (sender_host_authenticated) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"already authenticated"); + break; + } + if (sender_address) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"not permitted in mail transaction"); + break; + } + + /* Check the ACL */ + + GET_OPTION("acl_smtp_auth"); + if ( acl_smtp_auth + && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, + &user_msg, &log_msg)) != OK + ) + { + done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg); + break; + } + + /* Find the name of the requested authentication mechanism. */ + + s = smtp_cmd_data; + for (; (c = *smtp_cmd_data) && !isspace(c); smtp_cmd_data++) + if (!isalnum(c) && c != '-' && c != '_') + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"invalid character in authentication mechanism name"); + goto COMMAND_LOOP; + } + + /* If not at the end of the line, we must be at white space. Terminate the + name and move the pointer on to any data that may be present. */ + + if (*smtp_cmd_data) + { + *smtp_cmd_data++ = '\0'; + Uskip_whitespace(&smtp_cmd_data); + } + + /* Search for an authentication mechanism which is configured for use + as a server and which has been advertised (unless, sigh, allow_auth_ + unadvertised is set). */ + + { + auth_instance * au; + uschar * smtp_resp, * errmsg; + + for (au = auths; au; au = au->next) + if (strcmpic(s, au->public_name) == 0 && au->server && + (au->advertised || f.allow_auth_unadvertised)) + break; + + if (au) + { + int rc = smtp_in_auth(au, &smtp_resp, &errmsg); + + smtp_printf("%s\r\n", SP_NO_MORE, smtp_resp); + if (rc != OK) + { + uschar * logmsg = NULL; +#ifndef DISABLE_EVENT + {uschar * save_name = sender_host_authenticated; + sender_host_authenticated = au->name; + logmsg = event_raise(event_action, US"auth:fail", smtp_resp, NULL); + sender_host_authenticated = save_name; + } +#endif + if (logmsg) + log_write(0, LOG_MAIN|LOG_REJECT, "%s", logmsg); + else + log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s", + au->name, host_and_ident(FALSE), errmsg); + } + } + else + done = synprot_error(L_smtp_protocol_error, 504, NULL, + string_sprintf("%s authentication mechanism not supported", s)); + } + + break; /* AUTH_CMD */ - /* Check the ACL */ + /* The HELO/EHLO commands are permitted to appear in the middle of a + session as well as at the beginning. They have the effect of a reset in + addition to their other functions. Their absence at the start cannot be + taken to be an error. - if (acl_smtp_auth != NULL) - { - rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg); - if (rc != OK) - { - done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg); - break; - } - } + RFC 2821 says: - /* Find the name of the requested authentication mechanism. */ + If the EHLO command is not acceptable to the SMTP server, 501, 500, + or 502 failure replies MUST be returned as appropriate. The SMTP + server MUST stay in the same state after transmitting these replies + that it was in before the EHLO was received. - s = smtp_cmd_data; - while ((c = *smtp_cmd_data) != 0 && !isspace(c)) - { - if (!isalnum(c) && c != '-' && c != '_') - { - done = synprot_error(L_smtp_syntax_error, 501, NULL, - US"invalid character in authentication mechanism name"); - goto COMMAND_LOOP; - } - smtp_cmd_data++; - } + Therefore, we do not do the reset until after checking the command for + acceptability. This change was made for Exim release 4.11. Previously + it did the reset first. */ - /* If not at the end of the line, we must be at white space. Terminate the - name and move the pointer on to any data that may be present. */ + case HELO_CMD: + HAD(SCH_HELO); + hello = US"HELO"; + fl.esmtp = FALSE; + goto HELO_EHLO; - if (*smtp_cmd_data != 0) - { - *smtp_cmd_data++ = 0; - while (isspace(*smtp_cmd_data)) smtp_cmd_data++; - } + case EHLO_CMD: + HAD(SCH_EHLO); + hello = US"EHLO"; + fl.esmtp = TRUE; - /* Search for an authentication mechanism which is configured for use - as a server and which has been advertised (unless, sigh, allow_auth_ - unadvertised is set). */ + HELO_EHLO: /* Common code for HELO and EHLO */ + cmd_list[CL_HELO].is_mail_cmd = FALSE; + cmd_list[CL_EHLO].is_mail_cmd = FALSE; + + /* Reject the HELO if its argument was invalid or non-existent. A + successful check causes the argument to be saved in malloc store. */ + + if (!check_helo(smtp_cmd_data)) + { + smtp_printf("501 Syntactically invalid %s argument(s)\r\n", SP_NO_MORE, hello); + + log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically " + "invalid argument(s): %s", hello, host_and_ident(FALSE), + *smtp_cmd_argument == 0 ? US"(no argument given)" : + string_printing(smtp_cmd_argument)); + + if (++synprot_error_count > smtp_max_synprot_errors) + { + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " + "syntax or protocol errors (last command was \"%s\", %Y)", + host_and_ident(FALSE), string_printing(smtp_cmd_buffer), + s_connhad_log(NULL) + ); + done = 1; + } + + break; + } + + /* If sender_host_unknown is true, we have got here via the -bs interface, + not called from inetd. Otherwise, we are running an IP connection and the + host address will be set. If the helo name is the primary name of this + host and we haven't done a reverse lookup, force one now. If helo_verify_required + is set, ensure that the HELO name matches the actual host. If helo_verify + is set, do the same check, but softly. */ + + if (!f.sender_host_unknown) + { + BOOL old_helo_verified = f.helo_verified; + uschar * p = smtp_cmd_data; + + while (*p && !isspace(*p)) { *p = tolower(*p); p++; } + *p = '\0'; + + /* Force a reverse lookup if HELO quoted something in helo_lookup_domains + because otherwise the log can be confusing. */ + + if ( !sender_host_name + && match_isinlist(sender_helo_name, CUSS &helo_lookup_domains, 0, + &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK) + (void)host_name_lookup(); + + /* Rebuild the fullhost info to include the HELO name (and the real name + if it was looked up.) */ + + host_build_sender_fullhost(); /* Rebuild */ + set_process_info("handling%s incoming connection from %s", + tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE)); + + /* Verify if configured. This doesn't give much security, but it does + make some people happy to be able to do it. If helo_verify_required is set, + (host matches helo_verify_hosts) failure forces rejection. If helo_verify + is set (host matches helo_try_verify_hosts), it does not. This is perhaps + now obsolescent, since the verification can now be requested selectively + at ACL time. */ + + f.helo_verified = f.helo_verify_failed = sender_helo_dnssec = FALSE; + if (fl.helo_verify_required || fl.helo_verify) + { + BOOL tempfail = !smtp_verify_helo(); + if (!f.helo_verified) + { + if (fl.helo_verify_required) + { + smtp_printf("%d %s argument does not match calling host\r\n", SP_NO_MORE, + tempfail? 451 : 550, hello); + log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s", + tempfail? "temporarily " : "", + hello, sender_helo_name, host_and_ident(FALSE)); + f.helo_verified = old_helo_verified; + break; /* End of HELO/EHLO processing */ + } + HDEBUG(D_all) debug_printf("%s verification failed but host is in " + "helo_try_verify_hosts\n", hello); + } + } + } + +#ifdef SUPPORT_SPF + /* set up SPF context */ + spf_conn_init(sender_helo_name, sender_host_address); +#endif - for (au = auths; au != NULL; au = au->next) - { - if (strcmpic(s, au->public_name) == 0 && au->server && - (au->advertised || allow_auth_unadvertised)) break; - } + /* Apply an ACL check if one is defined; afterwards, recheck + synchronization in case the client started sending in a delay. */ + + GET_OPTION("acl_smtp_helo"); + if (acl_smtp_helo) + if ((rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, + &user_msg, &log_msg)) != OK) + { + done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg); + sender_helo_name = NULL; + host_build_sender_fullhost(); /* Rebuild */ + break; + } +#ifndef DISABLE_PIPE_CONNECT + else if (!fl.pipe_connect_acceptable && !check_sync()) +#else + else if (!check_sync()) +#endif + goto SYNC_FAILURE; + + /* Generate an OK reply. The default string includes the ident if present, + and also the IP address if present. Reflecting back the ident is intended + as a deterrent to mail forgers. For maximum efficiency, and also because + some broken systems expect each response to be in a single packet, arrange + that the entire reply is sent in one write(). */ + + fl.auth_advertised = FALSE; + f.smtp_in_pipelining_advertised = FALSE; +#ifndef DISABLE_TLS + fl.tls_advertised = FALSE; +#endif + fl.dsn_advertised = FALSE; +#ifdef SUPPORT_I18N + fl.smtputf8_advertised = FALSE; +#endif - if (au == NULL) - { - done = synprot_error(L_smtp_protocol_error, 504, NULL, - string_sprintf("%s authentication mechanism not supported", s)); - break; - } + /* Expand the per-connection message count limit option */ + smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection); + + smtp_code = US"250 "; /* Default response code plus space*/ + if (!user_msg) + { + /* sender_host_name below will be tainted, so save on copy when we hit it */ + g = string_get_tainted(24, GET_TAINTED); + g = string_fmt_append(g, "%.3s %s Hello %s%s%s", + smtp_code, + smtp_active_hostname, + sender_ident ? sender_ident : US"", + sender_ident ? US" at " : US"", + sender_host_name ? sender_host_name : sender_helo_name); + + if (sender_host_address) + g = string_fmt_append(g, " [%s]", sender_host_address); + } + + /* A user-supplied EHLO greeting may not contain more than one line. Note + that the code returned by smtp_message_code() includes the terminating + whitespace character. */ - /* Run the checking code, passing the remainder of the command line as - data. Initials the $auth variables as empty. Initialize $0 empty and set - it as the only set numerical variable. The authenticator may set $auth - and also set other numeric variables. The $auth variables are preferred - nowadays; the numerical variables remain for backwards compatibility. + else + { + char * ss; + int codelen = 4; + smtp_message_code(&smtp_code, &codelen, &user_msg, NULL, TRUE); + s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg); + if ((ss = strpbrk(CS s, "\r\n")) != NULL) + { + log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain " + "newlines: message truncated: %s", string_printing(s)); + *ss = 0; + } + g = string_cat(NULL, s); + } + + g = string_catn(g, US"\r\n", 2); + + /* If we received EHLO, we must create a multiline response which includes + the functions supported. */ + + if (fl.esmtp) + { + g->s[3] = '-'; /* overwrite the space after the SMTP response code */ + + /* I'm not entirely happy with this, as an MTA is supposed to check + that it has enough room to accept a message of maximum size before + it sends this. However, there seems little point in not sending it. + The actual size check happens later at MAIL FROM time. By postponing it + till then, VRFY and EXPN can be used after EHLO when space is short. */ + + if (thismessage_size_limit > 0) + g = string_fmt_append(g, "%.3s-SIZE %d\r\n", smtp_code, + thismessage_size_limit); + else + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-SIZE\r\n", 7); + } + +#ifndef DISABLE_ESMTP_LIMITS + if ( (smtp_mailcmd_max > 0 || recipients_max_expanded > 0) + && verify_check_host(&limits_advertise_hosts) == OK) + { + g = string_fmt_append(g, "%.3s-LIMITS", smtp_code); + if (smtp_mailcmd_max > 0) + g = string_fmt_append(g, " MAILMAX=%d", smtp_mailcmd_max); + if (recipients_max_expanded > 0) + g = string_fmt_append(g, " RCPTMAX=%d", recipients_max_expanded); + g = string_catn(g, US"\r\n", 2); + } +#endif - Afterwards, have a go at expanding the set_id string, even if - authentication failed - for bad passwords it can be useful to log the - userid. On success, require set_id to expand and exist, and put it in - authenticated_id. Save this in permanent store, as the working store gets - reset at HELO, RSET, etc. */ + /* Exim does not do protocol conversion or data conversion. It is 8-bit + clean; if it has an 8-bit character in its hand, it just sends it. It + cannot therefore specify 8BITMIME and remain consistent with the RFCs. + However, some users want this option simply in order to stop MUAs + mangling messages that contain top-bit-set characters. It is therefore + provided as an option. */ + + if (accept_8bitmime) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-8BITMIME\r\n", 11); + } + + /* Advertise DSN support if configured to do so. */ + if (verify_check_host(&dsn_advertise_hosts) != FAIL) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-DSN\r\n", 6); + fl.dsn_advertised = TRUE; + } + + /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is + permitted to issue them; a check is made when any host actually tries. */ + + GET_OPTION("acl_smtp_etrn"); + if (acl_smtp_etrn) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-ETRN\r\n", 7); + } + GET_OPTION("acl_smtp_vrfy"); + if (acl_smtp_vrfy) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-VRFY\r\n", 7); + } + GET_OPTION("acl_smtp_expn"); + if (acl_smtp_expn) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-EXPN\r\n", 7); + } + + /* Exim is quite happy with pipelining, so let the other end know that + it is safe to use it, unless advertising is disabled. */ + + if ( f.pipelining_enable + && verify_check_host(&pipelining_advertise_hosts) == OK) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-PIPELINING\r\n", 13); + sync_cmd_limit = NON_SYNC_CMD_PIPELINING; + f.smtp_in_pipelining_advertised = TRUE; + +#ifndef DISABLE_PIPE_CONNECT + if (fl.pipe_connect_acceptable) + { + f.smtp_in_early_pipe_advertised = TRUE; + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-" EARLY_PIPE_FEATURE_NAME "\r\n", EARLY_PIPE_FEATURE_LEN+3); + } +#endif + } - for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; - expand_nmax = 0; - expand_nlength[0] = 0; /* $0 contains nothing */ - c = (au->info->servercode)(au, smtp_cmd_data); - if (au->set_id != NULL) set_id = expand_string(au->set_id); - expand_nmax = -1; /* Reset numeric variables */ - for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth */ + /* If any server authentication mechanisms are configured, advertise + them if the current host is in auth_advertise_hosts. The problem with + advertising always is that some clients then require users to + authenticate (and aren't configurable otherwise) even though it may not + be necessary (e.g. if the host is in host_accept_relay). - /* The value of authenticated_id is stored in the spool file and printed in - log lines. It must not contain binary zeros or newline characters. In - normal use, it never will, but when playing around or testing, this error - can (did) happen. To guard against this, ensure that the id contains only - printing characters. */ + RFC 2222 states that SASL mechanism names contain only upper case + letters, so output the names in upper case, though we actually recognize + them in either case in the AUTH command. */ - if (set_id != NULL) set_id = string_printing(set_id); + if ( auths +#ifdef AUTH_TLS + && !sender_host_authenticated +#endif + && verify_check_host(&auth_advertise_hosts) == OK + ) + { + BOOL first = TRUE; + for (auth_instance * au = auths; au; au = au->next) + { + au->advertised = FALSE; + if (au->server) + { + DEBUG(D_auth+D_expand) debug_printf_indent( + "Evaluating advertise_condition for %s %s athenticator\n", + au->name, au->public_name); + if ( !au->advertise_condition + || expand_check_condition(au->advertise_condition, au->name, + US"authenticator") + ) + { + int saveptr; + if (first) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-AUTH", 5); + first = FALSE; + fl.auth_advertised = TRUE; + } + saveptr = gstring_length(g); + g = string_catn(g, US" ", 1); + g = string_cat(g, au->public_name); + while (++saveptr < g->ptr) g->s[saveptr] = toupper(g->s[saveptr]); + au->advertised = TRUE; + } + } + } + + if (!first) g = string_catn(g, US"\r\n", 2); + } + + /* RFC 3030 CHUNKING */ + + if (verify_check_host(&chunking_advertise_hosts) != FAIL) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-CHUNKING\r\n", 11); + f.chunking_offered = TRUE; + chunking_state = CHUNKING_OFFERED; + } + + /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer) + if it has been included in the binary, and the host matches + tls_advertise_hosts. We must *not* advertise if we are already in a + secure connection. */ + +#ifndef DISABLE_TLS + if (tls_in.active.sock < 0 && + verify_check_host(&tls_advertise_hosts) != FAIL) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-STARTTLS\r\n", 11); + fl.tls_advertised = TRUE; + } +#endif +#ifdef EXPERIMENTAL_XCLIENT + if (proxy_session || verify_check_host(&hosts_xclient) != FAIL) + { + g = string_catn(g, smtp_code, 3); + g = xclient_smtp_advertise_str(g); + } +#endif +#ifndef DISABLE_PRDR + /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */ + if (prdr_enable) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-PRDR\r\n", 7); + } +#endif - /* For the non-OK cases, set up additional logging data if set_id - is not empty. */ +#ifdef SUPPORT_I18N + if ( accept_8bitmime + && verify_check_host(&smtputf8_advertise_hosts) != FAIL) + { + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US"-SMTPUTF8\r\n", 11); + fl.smtputf8_advertised = TRUE; + } +#endif - if (c != OK) + /* Finish off the multiline reply with one that is always available. */ + + g = string_catn(g, smtp_code, 3); + g = string_catn(g, US" HELP\r\n", 7); + } + + /* Terminate the string (for debug), write it, and note that HELO/EHLO + has been seen. */ + + { + uschar * ehlo_resp; + int len = len_string_from_gstring(g, &ehlo_resp); +#ifndef DISABLE_TLS + if (tls_in.active.sock >= 0) + (void) tls_write(NULL, ehlo_resp, len, +# ifndef DISABLE_PIPE_CONNECT + fl.pipe_connect_acceptable && pipeline_connect_sends()); +# else + FALSE); +# endif + else +#endif + (void) fwrite(ehlo_resp, 1, len, smtp_out); + + DEBUG(D_receive) for (const uschar * t, * s = ehlo_resp; + s && (t = Ustrchr(s, '\r')); + s = t + 2) /* \r\n */ + debug_printf("%s %.*s\n", + s == g->s ? "SMTP>>" : " ", + (int)(t - s), s); + fl.helo_seen = TRUE; + } + + /* Reset the protocol and the state, abandoning any previous message. */ + received_protocol = + (sender_host_address ? protocols : protocols_local) + [ (fl.esmtp + ? pextend + (sender_host_authenticated ? pauthed : 0) + : pnormal) + + (tls_in.active.sock >= 0 ? pcrpted : 0) + ]; + cancel_cutthrough_connection(TRUE, US"sent EHLO response"); + reset_point = smtp_reset(reset_point); + toomany = FALSE; + break; /* HELO/EHLO */ + +#ifdef EXPERIMENTAL_XCLIENT + case XCLIENT_CMD: { - if (set_id != NULL && *set_id != 0) - set_id = string_sprintf(" (set_id=%s)", set_id); - else set_id = US""; + BOOL fatal = fl.helo_seen; + uschar * errmsg; + int resp; + + HAD(SCH_XCLIENT); + smtp_mailcmd_count++; + + if ((errmsg = xclient_smtp_command(smtp_cmd_data, &resp, &fatal))) + if (fatal) + done = synprot_error(L_smtp_syntax_error, resp, NULL, errmsg); + else + { + smtp_printf("%d %s\r\n", SP_NO_MORE, resp, errmsg); + log_write(0, LOG_MAIN|LOG_REJECT, "rejected XCLIENT from %s: %s", + host_and_ident(FALSE), errmsg); + } + else + { + fl.helo_seen = FALSE; /* Require another EHLO */ + smtp_code = string_sprintf("%d", resp); + + /*XXX unclear in spec. if this needs to be an ESMTP banner, + nor whether we get the original client's HELO after (or a proxy fake). + We require that we do; the following HELO/EHLO handling will set + sender_helo_name as normal. */ + + smtp_printf("%s XCLIENT success\r\n", SP_NO_MORE, smtp_code); + } + break; /* XCLIENT */ } +#endif - /* Switch on the result */ - - switch(c) - { - case OK: - if (au->set_id == NULL || set_id != NULL) /* Complete success */ - { - if (set_id != NULL) authenticated_id = string_copy_malloc(set_id); - sender_host_authenticated = au->name; - authentication_failed = FALSE; - received_protocol = - protocols[pextend + pauthed + ((tls_active >= 0)? pcrpted:0)] + - ((sender_host_address != NULL)? pnlocal : 0); - s = ss = US"235 Authentication succeeded"; - authenticated_by = au; - break; - } - /* Authentication succeeded, but we failed to expand the set_id string. - Treat this as a temporary error. */ + /* The MAIL command requires an address as an operand. All we do + here is to parse it for syntactic correctness. The form "<>" is + a special case which converts into an empty string. The start/end + pointers in the original are not used further for this address, as + it is the canonical extracted address which is all that is kept. */ - auth_defer_msg = expand_string_message; - /* Fall through */ + case MAIL_CMD: + HAD(SCH_MAIL); + smtp_mailcmd_count++; /* Count for limit and ratelimit */ + message_start(); + was_rej_mail = TRUE; /* Reset if accepted */ + env_mail_type_t * mail_args; /* Sanity check & validate args */ + + if (!fl.helo_seen) + if ( fl.helo_verify_required + || verify_check_host(&hosts_require_helo) == OK) + { + smtp_printf("503 HELO or EHLO required\r\n", SP_NO_MORE); + log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no " + "HELO/EHLO given", host_and_ident(FALSE)); + break; + } + else if (smtp_mailcmd_max < 0) + smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection); + + if (sender_address) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"sender already given"); + break; + } + + if (!*smtp_cmd_data) + { + done = synprot_error(L_smtp_protocol_error, 501, NULL, + US"MAIL must have an address operand"); + break; + } + + /* Check to see if the limit for messages per connection would be + exceeded by accepting further messages. */ + + if (smtp_mailcmd_max > 0 && smtp_mailcmd_count > smtp_mailcmd_max) + { + smtp_printf("421 too many messages in this connection\r\n", SP_NO_MORE); + log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many " + "messages in one connection", host_and_ident(TRUE)); + break; + } + + /* Reset for start of message - even if this is going to fail, we + obviously need to throw away any previous data. */ + + cancel_cutthrough_connection(TRUE, US"MAIL received"); + reset_point = smtp_reset(reset_point); + toomany = FALSE; + sender_data = recipient_data = NULL; + + /* Loop, checking for ESMTP additions to the MAIL FROM command. */ + + if (fl.esmtp) for(;;) + { + uschar *name, *value, *end; + unsigned long int size; + BOOL arg_error = FALSE; + + if (!extract_option(&name, &value)) break; + + for (mail_args = env_mail_type_list; + mail_args->value != ENV_MAIL_OPT_NULL; + mail_args++ + ) + if (strcmpic(name, mail_args->name) == 0) + break; + if (mail_args->need_value && strcmpic(value, US"") == 0) + break; + + switch(mail_args->value) + { + /* Handle SIZE= by reading the value. We don't do the check till later, + in order to be able to log the sender address on failure. */ + case ENV_MAIL_OPT_SIZE: + if (((size = Ustrtoul(value, &end, 10)), *end == 0)) + { + if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX) + size = INT_MAX; + message_size = (int)size; + } + else + arg_error = TRUE; + break; + + /* If this session was initiated with EHLO and accept_8bitmime is set, + Exim will have indicated that it supports the BODY=8BITMIME option. In + fact, it does not support this according to the RFCs, in that it does not + take any special action for forwarding messages containing 8-bit + characters. That is why accept_8bitmime is not the default setting, but + some sites want the action that is provided. We recognize both "8BITMIME" + and "7BIT" as body types, but take no action. */ + case ENV_MAIL_OPT_BODY: + if (accept_8bitmime) { + if (strcmpic(value, US"8BITMIME") == 0) + body_8bitmime = 8; + else if (strcmpic(value, US"7BIT") == 0) + body_8bitmime = 7; + else + { + body_8bitmime = 0; + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"invalid data for BODY"); + goto COMMAND_LOOP; + } + DEBUG(D_receive) debug_printf("8BITMIME: %d\n", body_8bitmime); + break; + } + arg_error = TRUE; + break; + + /* Handle the two DSN options, but only if configured to do so (which + will have caused "DSN" to be given in the EHLO response). The code itself + is included only if configured in at build time. */ + + case ENV_MAIL_OPT_RET: + if (fl.dsn_advertised) + { + /* Check if RET has already been set */ + if (dsn_ret > 0) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"RET can be specified once only"); + goto COMMAND_LOOP; + } + dsn_ret = strcmpic(value, US"HDRS") == 0 + ? dsn_ret_hdrs + : strcmpic(value, US"FULL") == 0 + ? dsn_ret_full + : 0; + DEBUG(D_receive) debug_printf("DSN_RET: %d\n", dsn_ret); + /* Check for invalid invalid value, and exit with error */ + if (dsn_ret == 0) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"Value for RET is invalid"); + goto COMMAND_LOOP; + } + } + break; + case ENV_MAIL_OPT_ENVID: + if (fl.dsn_advertised) + { + /* Check if the dsn envid has been already set */ + if (dsn_envid) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"ENVID can be specified once only"); + goto COMMAND_LOOP; + } + dsn_envid = string_copy(value); + DEBUG(D_receive) debug_printf("DSN_ENVID: %s\n", dsn_envid); + } + break; + + /* Handle the AUTH extension. If the value given is not "<>" and either + the ACL says "yes" or there is no ACL but the sending host is + authenticated, we set it up as the authenticated sender. However, if the + authenticator set a condition to be tested, we ignore AUTH on MAIL unless + the condition is met. The value of AUTH is an xtext, which means that +, + = and cntrl chars are coded in hex; however "<>" is unaffected by this + coding. */ + case ENV_MAIL_OPT_AUTH: + if (Ustrcmp(value, "<>") != 0) + { + int rc; + uschar *ignore_msg; + + if (auth_xtextdecode(value, &authenticated_sender) < 0) + { + /* Put back terminator overrides for error message */ + value[-1] = '='; + name[-1] = ' '; + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"invalid data for AUTH"); + goto COMMAND_LOOP; + } + GET_OPTION("acl_smtp_mailauth"); + if (!acl_smtp_mailauth) + { + ignore_msg = US"client not authenticated"; + rc = sender_host_authenticated ? OK : FAIL; + } + else + { + ignore_msg = US"rejected by ACL"; + rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth, + &user_msg, &log_msg); + } + + switch (rc) + { + case OK: + if (authenticated_by == NULL || + authenticated_by->mail_auth_condition == NULL || + expand_check_condition(authenticated_by->mail_auth_condition, + authenticated_by->name, US"authenticator")) + break; /* Accept the AUTH */ + + ignore_msg = US"server_mail_auth_condition failed"; + if (authenticated_id != NULL) + ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"", + ignore_msg, authenticated_id); + + /* Fall through */ + + case FAIL: + authenticated_sender = NULL; + log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)", + value, host_and_ident(TRUE), ignore_msg); + break; + + /* Should only get DEFER or ERROR here. Put back terminator + overrides for error message */ + + default: + value[-1] = '='; + name[-1] = ' '; + (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg, + log_msg); + goto COMMAND_LOOP; + } + } + break; + +#ifndef DISABLE_PRDR + case ENV_MAIL_OPT_PRDR: + if (prdr_enable) + prdr_requested = TRUE; + break; +#endif - case DEFER: - s = string_sprintf("435 Unable to authenticate at present%s", - auth_defer_user_msg); - ss = string_sprintf("435 Unable to authenticate at present%s: %s", - set_id, auth_defer_msg); - break; +#ifdef SUPPORT_I18N + case ENV_MAIL_OPT_UTF8: + if (!fl.smtputf8_advertised) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"SMTPUTF8 used when not advertised"); + goto COMMAND_LOOP; + } + + DEBUG(D_receive) debug_printf("smtputf8 requested\n"); + message_smtputf8 = allow_utf8_domains = TRUE; + if (Ustrncmp(received_protocol, US"utf8", 4) != 0) + { + int old_pool = store_pool; + store_pool = POOL_PERM; + received_protocol = string_sprintf("utf8%s", received_protocol); + store_pool = old_pool; + } + break; +#endif - case BAD64: - s = ss = US"501 Invalid base64 data"; + /* No valid option. Stick back the terminator characters and break + the loop. Do the name-terminator second as extract_option sets + value==name when it found no equal-sign. + An error for a malformed address will occur. */ + case ENV_MAIL_OPT_NULL: + value[-1] = '='; + name[-1] = ' '; + arg_error = TRUE; + break; + + default: assert(0); + } + /* Break out of for loop if switch() had bad argument or + when start of the email address is reached */ + if (arg_error) break; + } + + /* If we have passed the threshold for rate limiting, apply the current + delay, and update it for next time, provided this is a limited host. */ + + if (smtp_mailcmd_count > smtp_rlm_threshold && + verify_check_host(&smtp_ratelimit_hosts) == OK) + { + DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n", + smtp_delay_mail/1000.0); + millisleep((int)smtp_delay_mail); + smtp_delay_mail *= smtp_rlm_factor; + if (smtp_delay_mail > (double)smtp_rlm_limit) + smtp_delay_mail = (double)smtp_rlm_limit; + } + + /* Now extract the address, first applying any SMTP-time rewriting. The + TRUE flag allows "<>" as a sender address. */ + + raw_sender = rewrite_existflags & rewrite_smtp + /* deconst ok as smtp_cmd_data was not const */ + ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + global_rewrite_rules) + : smtp_cmd_data; + + raw_sender = + parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, + TRUE); + + if (!raw_sender) + { + done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); + break; + } + + sender_address = raw_sender; + + /* If there is a configured size limit for mail, check that this message + doesn't exceed it. The check is postponed to this point so that the sender + can be logged. */ + + if (thismessage_size_limit > 0 && message_size > thismessage_size_limit) + { + smtp_printf("552 Message size exceeds maximum permitted\r\n", SP_NO_MORE); + log_write(L_size_reject, + LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: " + "message too big: size%s=%d max=%d", + sender_address, + host_and_ident(TRUE), + (message_size == INT_MAX)? ">" : "", + message_size, + thismessage_size_limit); + sender_address = NULL; + break; + } + + /* Check there is enough space on the disk unless configured not to. + When smtp_check_spool_space is set, the check is for thismessage_size_limit + plus the current message - i.e. we accept the message only if it won't + reduce the space below the threshold. Add 5000 to the size to allow for + overheads such as the Received: line and storing of recipients, etc. + By putting the check here, even when SIZE is not given, it allow VRFY + and EXPN etc. to be used when space is short. */ + + if (!receive_check_fs( + smtp_check_spool_space && message_size >= 0 + ? message_size + 5000 : 0)) + { + smtp_printf("452 Space shortage, please try later\r\n", SP_NO_MORE); + sender_address = NULL; + break; + } + + /* If sender_address is unqualified, reject it, unless this is a locally + generated message, or the sending host or net is permitted to send + unqualified addresses - typically local machines behaving as MUAs - + in which case just qualify the address. The flag is set above at the start + of the SMTP connection. */ + + if (!sender_domain && *sender_address) + if (f.allow_unqualified_sender) + { + sender_domain = Ustrlen(sender_address) + 1; + /* deconst ok as sender_address was not const */ + sender_address = US rewrite_address_qualify(sender_address, FALSE); + DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", + raw_sender); + } + else + { + smtp_printf("501 %s: sender address must contain a domain\r\n", SP_NO_MORE, + smtp_cmd_data); + log_write(L_smtp_syntax_error, + LOG_MAIN|LOG_REJECT, + "unqualified sender rejected: <%s> %s%s", + raw_sender, + host_and_ident(TRUE), + host_lookup_msg); + sender_address = NULL; + break; + } + + /* Apply an ACL check if one is defined, before responding. Afterwards, + when pipelining is not advertised, do another sync check in case the ACL + delayed and the client started sending in the meantime. */ + + GET_OPTION("acl_smtp_mail"); + if (acl_smtp_mail) + { + rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg); + if (rc == OK && !f.smtp_in_pipelining_advertised && !check_sync()) + goto SYNC_FAILURE; + } + else + rc = OK; + + if (rc == OK || rc == DISCARD) + { + BOOL more = pipeline_response(); + + if (!user_msg) + smtp_printf("%s%s%s", more, US"250 OK", + #ifndef DISABLE_PRDR + prdr_requested ? US", PRDR Requested" : US"", + #else + US"", + #endif + US"\r\n"); + else + { + #ifndef DISABLE_PRDR + if (prdr_requested) + user_msg = string_sprintf("%s%s", user_msg, US", PRDR Requested"); + #endif + smtp_user_msg(US"250", user_msg); + } + smtp_delay_rcpt = smtp_rlr_base; + f.recipients_discarded = (rc == DISCARD); + was_rej_mail = FALSE; + } + else + { + done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg); + sender_address = NULL; + } break; - case CANCELLED: - s = ss = US"501 Authentication cancelled"; - break; - case UNEXPECTED: - s = ss = US"553 Initial data not expected"; - break; + /* The RCPT command requires an address as an operand. There may be any + number of RCPT commands, specifying multiple recipients. We build them all + into a data structure. The start/end values given by parse_extract_address + are not used, as we keep only the extracted address. */ - case FAIL: - s = US"535 Incorrect authentication data"; - ss = string_sprintf("535 Incorrect authentication data%s", set_id); - break; + case RCPT_CMD: + HAD(SCH_RCPT); + /* We got really to many recipients. A check against configured + limits is done later */ + if (rcpt_count < 0 || rcpt_count >= INT_MAX/2) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Too many recipients: %d", rcpt_count); + rcpt_count++; + was_rcpt = fl.rcpt_in_progress = TRUE; + + /* There must be a sender address; if the sender was rejected and + pipelining was advertised, we assume the client was pipelining, and do not + count this as a protocol error. Reset was_rej_mail so that further RCPTs + get the same treatment. */ + + if (!sender_address) + { + if (f.smtp_in_pipelining_advertised && last_was_rej_mail) + { + smtp_printf("503 sender not yet given\r\n", SP_NO_MORE); + was_rej_mail = TRUE; + } + else + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"sender not yet given"); + was_rcpt = FALSE; /* Not a valid RCPT */ + } + rcpt_fail_count++; + break; + } + + /* Check for an operand */ + + if (!smtp_cmd_data[0]) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"RCPT must have an address operand"); + rcpt_fail_count++; + break; + } + + /* Set the DSN flags orcpt and dsn_flags from the session*/ + orcpt = NULL; + dsn_flags = 0; + + if (fl.esmtp) for(;;) + { + uschar *name, *value; + + if (!extract_option(&name, &value)) + break; + + if (fl.dsn_advertised && strcmpic(name, US"ORCPT") == 0) + { + /* Check whether orcpt has been already set */ + if (orcpt) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"ORCPT can be specified once only"); + goto COMMAND_LOOP; + } + orcpt = string_copy(value); + DEBUG(D_receive) debug_printf("DSN orcpt: %s\n", orcpt); + } + + else if (fl.dsn_advertised && strcmpic(name, US"NOTIFY") == 0) + { + /* Check if the notify flags have been already set */ + if (dsn_flags > 0) + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"NOTIFY can be specified once only"); + goto COMMAND_LOOP; + } + if (strcmpic(value, US"NEVER") == 0) + dsn_flags |= rf_notify_never; + else + { + uschar *p = value; + while (*p != 0) + { + uschar *pp = p; + while (*pp != 0 && *pp != ',') pp++; + if (*pp == ',') *pp++ = 0; + if (strcmpic(p, US"SUCCESS") == 0) + { + DEBUG(D_receive) debug_printf("DSN: Setting notify success\n"); + dsn_flags |= rf_notify_success; + } + else if (strcmpic(p, US"FAILURE") == 0) + { + DEBUG(D_receive) debug_printf("DSN: Setting notify failure\n"); + dsn_flags |= rf_notify_failure; + } + else if (strcmpic(p, US"DELAY") == 0) + { + DEBUG(D_receive) debug_printf("DSN: Setting notify delay\n"); + dsn_flags |= rf_notify_delay; + } + else + { + /* Catch any strange values */ + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"Invalid value for NOTIFY parameter"); + goto COMMAND_LOOP; + } + p = pp; + } + DEBUG(D_receive) debug_printf("DSN Flags: %x\n", dsn_flags); + } + } + + /* Unknown option. Stick back the terminator characters and break + the loop. An error for a malformed address will occur. */ + + else + { + DEBUG(D_receive) debug_printf("Invalid RCPT option: %s : %s\n", name, value); + name[-1] = ' '; + value[-1] = '='; + break; + } + } + + /* Apply SMTP rewriting then extract the working address. Don't allow "<>" + as a recipient address */ + + recipient = rewrite_existflags & rewrite_smtp + /* deconst ok as smtp_cmd_data was not const */ + ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + global_rewrite_rules) + : smtp_cmd_data; + + if (!(recipient = parse_extract_address(recipient, &errmess, &start, &end, + &recipient_domain, FALSE))) + { + done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); + rcpt_fail_count++; + break; + } + + /* If the recipient address is unqualified, reject it, unless this is a + locally generated message. However, unqualified addresses are permitted + from a configured list of hosts and nets - typically when behaving as + MUAs rather than MTAs. Sad that SMTP is used for both types of traffic, + really. The flag is set at the start of the SMTP connection. + + RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always + assumed this meant "reserved local part", but the revision of RFC 821 and + friends now makes it absolutely clear that it means *mailbox*. Consequently + we must always qualify this address, regardless. */ + + if (!recipient_domain) + if (!(recipient_domain = qualify_recipient(&recipient, smtp_cmd_data, + US"recipient"))) + { + rcpt_fail_count++; + break; + } + + /* Check maximum allowed */ + + if ( rcpt_count+1 < 0 + || rcpt_count > recipients_max_expanded && recipients_max_expanded > 0) + { + if (recipients_max_reject) + { + rcpt_fail_count++; + smtp_printf("552 too many recipients\r\n", SP_NO_MORE); + if (!toomany) + log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message " + "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE)); + } + else + { + rcpt_defer_count++; + smtp_printf("452 too many recipients\r\n", SP_NO_MORE); + if (!toomany) + log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess " + "temporarily rejected: sender=<%s> %s", sender_address, + host_and_ident(TRUE)); + } + + toomany = TRUE; + break; + } + + /* If we have passed the threshold for rate limiting, apply the current + delay, and update it for next time, provided this is a limited host. */ + + if (rcpt_count > smtp_rlr_threshold && + verify_check_host(&smtp_ratelimit_hosts) == OK) + { + DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n", + smtp_delay_rcpt/1000.0); + millisleep((int)smtp_delay_rcpt); + smtp_delay_rcpt *= smtp_rlr_factor; + if (smtp_delay_rcpt > (double)smtp_rlr_limit) + smtp_delay_rcpt = (double)smtp_rlr_limit; + } + + /* If the MAIL ACL discarded all the recipients, we bypass ACL checking + for them. Otherwise, check the access control list for this recipient. As + there may be a delay in this, re-check for a synchronization error + afterwards, unless pipelining was advertised. */ + + if (f.recipients_discarded) + rc = DISCARD; + else + { + GET_OPTION("acl_smtp_rcpt"); + if ( (rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg, + &log_msg)) == OK + && !f.smtp_in_pipelining_advertised && !check_sync()) + goto SYNC_FAILURE; + } + + /* The ACL was happy */ + + if (rc == OK) + { + BOOL more = pipeline_response(); + + if (user_msg) + smtp_user_msg(US"250", user_msg); + else + smtp_printf("250 Accepted\r\n", more); + receive_add_recipient(recipient, -1); + + /* Set the dsn flags in the recipients_list */ + recipients_list[recipients_count-1].orcpt = orcpt; + recipients_list[recipients_count-1].dsn_flags = dsn_flags; + + /* DEBUG(D_receive) debug_printf("DSN: orcpt: %s flags: %d\n", + recipients_list[recipients_count-1].orcpt, + recipients_list[recipients_count-1].dsn_flags); */ + } + + /* The recipient was discarded */ + + else if (rc == DISCARD) + { + if (user_msg) + smtp_user_msg(US"250", user_msg); + else + smtp_printf("250 Accepted\r\n", SP_NO_MORE); + rcpt_fail_count++; + discarded = TRUE; + log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> RCPT %s: " + "discarded by %s ACL%s%s", host_and_ident(TRUE), + sender_address_unrewritten ? sender_address_unrewritten : sender_address, + smtp_cmd_argument, f.recipients_discarded ? "MAIL" : "RCPT", + log_msg ? US": " : US"", log_msg ? log_msg : US""); + } + + /* Either the ACL failed the address, or it was deferred. */ - default: - s = US"435 Internal error"; - ss = string_sprintf("435 Internal error%s: return %d from authentication " - "check", set_id, c); + else + { + if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++; + done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg); + } break; - } - - smtp_printf("%s\r\n", s); - if (c != OK) - log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s", - au->name, host_and_ident(FALSE), ss); - - break; /* AUTH_CMD */ - - /* The HELO/EHLO commands are permitted to appear in the middle of a - session as well as at the beginning. They have the effect of a reset in - addition to their other functions. Their absence at the start cannot be - taken to be an error. - - RFC 2821 says: - - If the EHLO command is not acceptable to the SMTP server, 501, 500, - or 502 failure replies MUST be returned as appropriate. The SMTP - server MUST stay in the same state after transmitting these replies - that it was in before the EHLO was received. - - Therefore, we do not do the reset until after checking the command for - acceptability. This change was made for Exim release 4.11. Previously - it did the reset first. */ - - case HELO_CMD: - HAD(SCH_HELO); - hello = US"HELO"; - esmtp = FALSE; - goto HELO_EHLO; - - case EHLO_CMD: - HAD(SCH_EHLO); - hello = US"EHLO"; - esmtp = TRUE; - - HELO_EHLO: /* Common code for HELO and EHLO */ - cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE; - cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE; - - /* Reject the HELO if its argument was invalid or non-existent. A - successful check causes the argument to be saved in malloc store. */ - - if (!check_helo(smtp_cmd_data)) - { - smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello); - - log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically " - "invalid argument(s): %s", hello, host_and_ident(FALSE), - (*smtp_cmd_argument == 0)? US"(no argument given)" : - string_printing(smtp_cmd_argument)); - - if (++synprot_error_count > smtp_max_synprot_errors) - { - log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " - "syntax or protocol errors (last command was \"%s\")", - host_and_ident(FALSE), smtp_cmd_buffer); - done = 1; - } - - break; - } - - /* If sender_host_unknown is true, we have got here via the -bs interface, - not called from inetd. Otherwise, we are running an IP connection and the - host address will be set. If the helo name is the primary name of this - host and we haven't done a reverse lookup, force one now. If helo_required - is set, ensure that the HELO name matches the actual host. If helo_verify - is set, do the same check, but softly. */ - - if (!sender_host_unknown) - { - BOOL old_helo_verified = helo_verified; - uschar *p = smtp_cmd_data; - - while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; } - *p = 0; - - /* Force a reverse lookup if HELO quoted something in helo_lookup_domains - because otherwise the log can be confusing. */ - - if (sender_host_name == NULL && - (deliver_domain = sender_helo_name, /* set $domain */ - match_isinlist(sender_helo_name, &helo_lookup_domains, 0, - &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK) - (void)host_name_lookup(); - - /* Rebuild the fullhost info to include the HELO name (and the real name - if it was looked up.) */ - - host_build_sender_fullhost(); /* Rebuild */ - set_process_info("handling%s incoming connection from %s", - (tls_active >= 0)? " TLS" : "", host_and_ident(FALSE)); - - /* Verify if configured. This doesn't give much security, but it does - make some people happy to be able to do it. If helo_required is set, - (host matches helo_verify_hosts) failure forces rejection. If helo_verify - is set (host matches helo_try_verify_hosts), it does not. This is perhaps - now obsolescent, since the verification can now be requested selectively - at ACL time. */ - - helo_verified = helo_verify_failed = FALSE; - if (helo_required || helo_verify) - { - BOOL tempfail = !smtp_verify_helo(); - if (!helo_verified) - { - if (helo_required) - { - smtp_printf("%d %s argument does not match calling host\r\n", - tempfail? 451 : 550, hello); - log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s", - tempfail? "temporarily " : "", - hello, sender_helo_name, host_and_ident(FALSE)); - helo_verified = old_helo_verified; - break; /* End of HELO/EHLO processing */ - } - HDEBUG(D_all) debug_printf("%s verification failed but host is in " - "helo_try_verify_hosts\n", hello); - } - } - } - -#ifdef EXPERIMENTAL_SPF - /* set up SPF context */ - spf_init(sender_helo_name, sender_host_address); -#endif - - /* Apply an ACL check if one is defined; afterwards, recheck - synchronization in case the client started sending in a delay. */ - - if (acl_smtp_helo != NULL) - { - rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg); - if (rc != OK) - { - done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg); - sender_helo_name = NULL; - host_build_sender_fullhost(); /* Rebuild */ - break; - } - else if (!check_sync()) goto SYNC_FAILURE; - } - - /* Generate an OK reply. The default string includes the ident if present, - and also the IP address if present. Reflecting back the ident is intended - as a deterrent to mail forgers. For maximum efficiency, and also because - some broken systems expect each response to be in a single packet, arrange - that the entire reply is sent in one write(). */ - - auth_advertised = FALSE; - pipelining_advertised = FALSE; - #ifdef SUPPORT_TLS - tls_advertised = FALSE; - #endif - - smtp_code = US"250 "; /* Default response code plus space*/ - if (user_msg == NULL) - { - s = string_sprintf("%.3s %s Hello %s%s%s", - smtp_code, - smtp_active_hostname, - (sender_ident == NULL)? US"" : sender_ident, - (sender_ident == NULL)? US"" : US" at ", - (sender_host_name == NULL)? sender_helo_name : sender_host_name); - - ptr = Ustrlen(s); - size = ptr + 1; - - if (sender_host_address != NULL) - { - s = string_cat(s, &size, &ptr, US" [", 2); - s = string_cat(s, &size, &ptr, sender_host_address, - Ustrlen(sender_host_address)); - s = string_cat(s, &size, &ptr, US"]", 1); - } - } - - /* A user-supplied EHLO greeting may not contain more than one line. Note - that the code returned by smtp_message_code() includes the terminating - whitespace character. */ - - else - { - char *ss; - int codelen = 4; - smtp_message_code(&smtp_code, &codelen, &user_msg, NULL); - s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg); - if ((ss = strpbrk(CS s, "\r\n")) != NULL) - { - log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain " - "newlines: message truncated: %s", string_printing(s)); - *ss = 0; - } - ptr = Ustrlen(s); - size = ptr + 1; - } - - s = string_cat(s, &size, &ptr, US"\r\n", 2); - - /* If we received EHLO, we must create a multiline response which includes - the functions supported. */ - - if (esmtp) - { - s[3] = '-'; - - /* I'm not entirely happy with this, as an MTA is supposed to check - that it has enough room to accept a message of maximum size before - it sends this. However, there seems little point in not sending it. - The actual size check happens later at MAIL FROM time. By postponing it - till then, VRFY and EXPN can be used after EHLO when space is short. */ - - if (thismessage_size_limit > 0) - { - sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code, - thismessage_size_limit); - s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer)); - } - else - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7); - } - - /* Exim does not do protocol conversion or data conversion. It is 8-bit - clean; if it has an 8-bit character in its hand, it just sends it. It - cannot therefore specify 8BITMIME and remain consistent with the RFCs. - However, some users want this option simply in order to stop MUAs - mangling messages that contain top-bit-set characters. It is therefore - provided as an option. */ - - if (accept_8bitmime) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11); - } - - /* Advertise ETRN if there's an ACL checking whether a host is - permitted to issue it; a check is made when any host actually tries. */ - - if (acl_smtp_etrn != NULL) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7); - } - - /* Advertise EXPN if there's an ACL checking whether a host is - permitted to issue it; a check is made when any host actually tries. */ - - if (acl_smtp_expn != NULL) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7); - } - - /* Exim is quite happy with pipelining, so let the other end know that - it is safe to use it, unless advertising is disabled. */ - - if (pipelining_enable && - verify_check_host(&pipelining_advertise_hosts) == OK) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13); - sync_cmd_limit = NON_SYNC_CMD_PIPELINING; - pipelining_advertised = TRUE; - } - - /* If any server authentication mechanisms are configured, advertise - them if the current host is in auth_advertise_hosts. The problem with - advertising always is that some clients then require users to - authenticate (and aren't configurable otherwise) even though it may not - be necessary (e.g. if the host is in host_accept_relay). - - RFC 2222 states that SASL mechanism names contain only upper case - letters, so output the names in upper case, though we actually recognize - them in either case in the AUTH command. */ - - if (auths != NULL) - { - if (verify_check_host(&auth_advertise_hosts) == OK) - { - auth_instance *au; - BOOL first = TRUE; - for (au = auths; au != NULL; au = au->next) - { - if (au->server && (au->advertise_condition == NULL || - expand_check_condition(au->advertise_condition, au->name, - US"authenticator"))) - { - int saveptr; - if (first) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-AUTH", 5); - first = FALSE; - auth_advertised = TRUE; - } - saveptr = ptr; - s = string_cat(s, &size, &ptr, US" ", 1); - s = string_cat(s, &size, &ptr, au->public_name, - Ustrlen(au->public_name)); - while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]); - au->advertised = TRUE; - } - else au->advertised = FALSE; - } - if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2); - } - } - - /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer) - if it has been included in the binary, and the host matches - tls_advertise_hosts. We must *not* advertise if we are already in a - secure connection. */ - - #ifdef SUPPORT_TLS - if (tls_active < 0 && - verify_check_host(&tls_advertise_hosts) != FAIL) - { - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11); - tls_advertised = TRUE; - } - #endif - - /* Finish off the multiline reply with one that is always available. */ - - s = string_cat(s, &size, &ptr, smtp_code, 3); - s = string_cat(s, &size, &ptr, US" HELP\r\n", 7); - } - - /* Terminate the string (for debug), write it, and note that HELO/EHLO - has been seen. */ - - s[ptr] = 0; - - #ifdef SUPPORT_TLS - if (tls_active >= 0) (void)tls_write(s, ptr); else - #endif - - (void)fwrite(s, 1, ptr, smtp_out); - DEBUG(D_receive) - { - uschar *cr; - while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */ - memmove(cr, cr + 1, (ptr--) - (cr - s)); - debug_printf("SMTP>> %s", s); - } - helo_seen = TRUE; - - /* Reset the protocol and the state, abandoning any previous message. */ - - received_protocol = (esmtp? - protocols[pextend + - ((sender_host_authenticated != NULL)? pauthed : 0) + - ((tls_active >= 0)? pcrpted : 0)] - : - protocols[pnormal + ((tls_active >= 0)? pcrpted : 0)]) - + - ((sender_host_address != NULL)? pnlocal : 0); - - smtp_reset(reset_point); - toomany = FALSE; - break; /* HELO/EHLO */ - - - /* The MAIL command requires an address as an operand. All we do - here is to parse it for syntactic correctness. The form "<>" is - a special case which converts into an empty string. The start/end - pointers in the original are not used further for this address, as - it is the canonical extracted address which is all that is kept. */ - - case MAIL_CMD: - HAD(SCH_MAIL); - smtp_mailcmd_count++; /* Count for limit and ratelimit */ - was_rej_mail = TRUE; /* Reset if accepted */ - - if (helo_required && !helo_seen) - { - smtp_printf("503 HELO or EHLO required\r\n"); - log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no " - "HELO/EHLO given", host_and_ident(FALSE)); - break; - } - - if (sender_address != NULL) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"sender already given"); - break; - } - - if (smtp_cmd_data[0] == 0) - { - done = synprot_error(L_smtp_protocol_error, 501, NULL, - US"MAIL must have an address operand"); - break; - } - - /* Check to see if the limit for messages per connection would be - exceeded by accepting further messages. */ - - if (smtp_accept_max_per_connection > 0 && - smtp_mailcmd_count > smtp_accept_max_per_connection) - { - smtp_printf("421 too many messages in this connection\r\n"); - log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many " - "messages in one connection", host_and_ident(TRUE)); - break; - } - - /* Reset for start of message - even if this is going to fail, we - obviously need to throw away any previous data. */ - - smtp_reset(reset_point); - toomany = FALSE; - sender_data = recipient_data = NULL; - - /* Loop, checking for ESMTP additions to the MAIL FROM command. */ - - if (esmtp) for(;;) - { - uschar *name, *value, *end; - unsigned long int size; - - if (!extract_option(&name, &value)) break; - - /* Handle SIZE= by reading the value. We don't do the check till later, - in order to be able to log the sender address on failure. */ - - if (strcmpic(name, US"SIZE") == 0 && - ((size = Ustrtoul(value, &end, 10)), *end == 0)) - { - if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX) - size = INT_MAX; - message_size = (int)size; - } - - /* If this session was initiated with EHLO and accept_8bitmime is set, - Exim will have indicated that it supports the BODY=8BITMIME option. In - fact, it does not support this according to the RFCs, in that it does not - take any special action for forwarding messages containing 8-bit - characters. That is why accept_8bitmime is not the default setting, but - some sites want the action that is provided. We recognize both "8BITMIME" - and "7BIT" as body types, but take no action. */ - - else if (accept_8bitmime && strcmpic(name, US"BODY") == 0 && - (strcmpic(value, US"8BITMIME") == 0 || - strcmpic(value, US"7BIT") == 0)) {} - - /* Handle the AUTH extension. If the value given is not "<>" and either - the ACL says "yes" or there is no ACL but the sending host is - authenticated, we set it up as the authenticated sender. However, if the - authenticator set a condition to be tested, we ignore AUTH on MAIL unless - the condition is met. The value of AUTH is an xtext, which means that +, - = and cntrl chars are coded in hex; however "<>" is unaffected by this - coding. */ - - else if (strcmpic(name, US"AUTH") == 0) - { - if (Ustrcmp(value, "<>") != 0) - { - int rc; - uschar *ignore_msg; - - if (auth_xtextdecode(value, &authenticated_sender) < 0) - { - /* Put back terminator overrides for error message */ - name[-1] = ' '; - value[-1] = '='; - done = synprot_error(L_smtp_syntax_error, 501, NULL, - US"invalid data for AUTH"); - goto COMMAND_LOOP; - } - - if (acl_smtp_mailauth == NULL) - { - ignore_msg = US"client not authenticated"; - rc = (sender_host_authenticated != NULL)? OK : FAIL; - } - else - { - ignore_msg = US"rejected by ACL"; - rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth, - &user_msg, &log_msg); - } - - switch (rc) - { - case OK: - if (authenticated_by == NULL || - authenticated_by->mail_auth_condition == NULL || - expand_check_condition(authenticated_by->mail_auth_condition, - authenticated_by->name, US"authenticator")) - break; /* Accept the AUTH */ - - ignore_msg = US"server_mail_auth_condition failed"; - if (authenticated_id != NULL) - ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"", - ignore_msg, authenticated_id); - - /* Fall through */ - - case FAIL: - authenticated_sender = NULL; - log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)", - value, host_and_ident(TRUE), ignore_msg); - break; - - /* Should only get DEFER or ERROR here. Put back terminator - overrides for error message */ - - default: - name[-1] = ' '; - value[-1] = '='; - (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg, - log_msg); - goto COMMAND_LOOP; - } - } - } - - /* Unknown option. Stick back the terminator characters and break - the loop. An error for a malformed address will occur. */ - - else - { - name[-1] = ' '; - value[-1] = '='; - break; - } - } - - /* If we have passed the threshold for rate limiting, apply the current - delay, and update it for next time, provided this is a limited host. */ - - if (smtp_mailcmd_count > smtp_rlm_threshold && - verify_check_host(&smtp_ratelimit_hosts) == OK) - { - DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n", - smtp_delay_mail/1000.0); - millisleep((int)smtp_delay_mail); - smtp_delay_mail *= smtp_rlm_factor; - if (smtp_delay_mail > (double)smtp_rlm_limit) - smtp_delay_mail = (double)smtp_rlm_limit; - } - - /* Now extract the address, first applying any SMTP-time rewriting. The - TRUE flag allows "<>" as a sender address. */ - - raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? - rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", - global_rewrite_rules) : smtp_cmd_data; - - /* rfc821_domains = TRUE; << no longer needed */ - raw_sender = - parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, - TRUE); - /* rfc821_domains = FALSE; << no longer needed */ - - if (raw_sender == NULL) - { - done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); - break; - } - - sender_address = raw_sender; - - /* If there is a configured size limit for mail, check that this message - doesn't exceed it. The check is postponed to this point so that the sender - can be logged. */ - - if (thismessage_size_limit > 0 && message_size > thismessage_size_limit) - { - smtp_printf("552 Message size exceeds maximum permitted\r\n"); - log_write(L_size_reject, - LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: " - "message too big: size%s=%d max=%d", - sender_address, - host_and_ident(TRUE), - (message_size == INT_MAX)? ">" : "", - message_size, - thismessage_size_limit); - sender_address = NULL; - break; - } - - /* Check there is enough space on the disk unless configured not to. - When smtp_check_spool_space is set, the check is for thismessage_size_limit - plus the current message - i.e. we accept the message only if it won't - reduce the space below the threshold. Add 5000 to the size to allow for - overheads such as the Received: line and storing of recipients, etc. - By putting the check here, even when SIZE is not given, it allow VRFY - and EXPN etc. to be used when space is short. */ - - if (!receive_check_fs( - (smtp_check_spool_space && message_size >= 0)? - message_size + 5000 : 0)) - { - smtp_printf("452 Space shortage, please try later\r\n"); - sender_address = NULL; - break; - } - - /* If sender_address is unqualified, reject it, unless this is a locally - generated message, or the sending host or net is permitted to send - unqualified addresses - typically local machines behaving as MUAs - - in which case just qualify the address. The flag is set above at the start - of the SMTP connection. */ - - if (sender_domain == 0 && sender_address[0] != 0) - { - if (allow_unqualified_sender) - { - sender_domain = Ustrlen(sender_address) + 1; - sender_address = rewrite_address_qualify(sender_address, FALSE); - DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", - raw_sender); - } - else - { - smtp_printf("501 %s: sender address must contain a domain\r\n", - smtp_cmd_data); - log_write(L_smtp_syntax_error, - LOG_MAIN|LOG_REJECT, - "unqualified sender rejected: <%s> %s%s", - raw_sender, - host_and_ident(TRUE), - host_lookup_msg); - sender_address = NULL; - break; - } - } - - /* Apply an ACL check if one is defined, before responding. Afterwards, - when pipelining is not advertised, do another sync check in case the ACL - delayed and the client started sending in the meantime. */ - - if (acl_smtp_mail == NULL) rc = OK; else - { - rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg); - if (rc == OK && !pipelining_advertised && !check_sync()) - goto SYNC_FAILURE; - } - - if (rc == OK || rc == DISCARD) - { - if (user_msg == NULL) smtp_printf("250 OK\r\n"); - else smtp_user_msg(US"250", user_msg); - smtp_delay_rcpt = smtp_rlr_base; - recipients_discarded = (rc == DISCARD); - was_rej_mail = FALSE; - } - else - { - done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg); - sender_address = NULL; - } - break; - - - /* The RCPT command requires an address as an operand. There may be any - number of RCPT commands, specifying multiple recipients. We build them all - into a data structure. The start/end values given by parse_extract_address - are not used, as we keep only the extracted address. */ - - case RCPT_CMD: - HAD(SCH_RCPT); - rcpt_count++; - was_rcpt = rcpt_in_progress = TRUE; - - /* There must be a sender address; if the sender was rejected and - pipelining was advertised, we assume the client was pipelining, and do not - count this as a protocol error. Reset was_rej_mail so that further RCPTs - get the same treatment. */ - - if (sender_address == NULL) - { - if (pipelining_advertised && last_was_rej_mail) - { - smtp_printf("503 sender not yet given\r\n"); - was_rej_mail = TRUE; - } - else - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"sender not yet given"); - was_rcpt = FALSE; /* Not a valid RCPT */ - } - rcpt_fail_count++; - break; - } - - /* Check for an operand */ - - if (smtp_cmd_data[0] == 0) - { - done = synprot_error(L_smtp_syntax_error, 501, NULL, - US"RCPT must have an address operand"); - rcpt_fail_count++; - break; - } - - /* Apply SMTP rewriting then extract the working address. Don't allow "<>" - as a recipient address */ - - recipient = ((rewrite_existflags & rewrite_smtp) != 0)? - rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", - global_rewrite_rules) : smtp_cmd_data; - - /* rfc821_domains = TRUE; << no longer needed */ - recipient = parse_extract_address(recipient, &errmess, &start, &end, - &recipient_domain, FALSE); - /* rfc821_domains = FALSE; << no longer needed */ - - if (recipient == NULL) - { - done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); - rcpt_fail_count++; - break; - } - - /* If the recipient address is unqualified, reject it, unless this is a - locally generated message. However, unqualified addresses are permitted - from a configured list of hosts and nets - typically when behaving as - MUAs rather than MTAs. Sad that SMTP is used for both types of traffic, - really. The flag is set at the start of the SMTP connection. - - RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always - assumed this meant "reserved local part", but the revision of RFC 821 and - friends now makes it absolutely clear that it means *mailbox*. Consequently - we must always qualify this address, regardless. */ - - if (recipient_domain == 0) - { - if (allow_unqualified_recipient || - strcmpic(recipient, US"postmaster") == 0) - { - DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", - recipient); - recipient_domain = Ustrlen(recipient) + 1; - recipient = rewrite_address_qualify(recipient, TRUE); - } - else - { - rcpt_fail_count++; - smtp_printf("501 %s: recipient address must contain a domain\r\n", - smtp_cmd_data); - log_write(L_smtp_syntax_error, - LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: " - "<%s> %s%s", recipient, host_and_ident(TRUE), - host_lookup_msg); - break; - } - } - - /* Check maximum allowed */ - - if (rcpt_count > recipients_max && recipients_max > 0) - { - if (recipients_max_reject) - { - rcpt_fail_count++; - smtp_printf("552 too many recipients\r\n"); - if (!toomany) - log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message " - "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE)); - } - else - { - rcpt_defer_count++; - smtp_printf("452 too many recipients\r\n"); - if (!toomany) - log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess " - "temporarily rejected: sender=<%s> %s", sender_address, - host_and_ident(TRUE)); - } - - toomany = TRUE; - break; - } - - /* If we have passed the threshold for rate limiting, apply the current - delay, and update it for next time, provided this is a limited host. */ - - if (rcpt_count > smtp_rlr_threshold && - verify_check_host(&smtp_ratelimit_hosts) == OK) - { - DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n", - smtp_delay_rcpt/1000.0); - millisleep((int)smtp_delay_rcpt); - smtp_delay_rcpt *= smtp_rlr_factor; - if (smtp_delay_rcpt > (double)smtp_rlr_limit) - smtp_delay_rcpt = (double)smtp_rlr_limit; - } - - /* If the MAIL ACL discarded all the recipients, we bypass ACL checking - for them. Otherwise, check the access control list for this recipient. As - there may be a delay in this, re-check for a synchronization error - afterwards, unless pipelining was advertised. */ - - if (recipients_discarded) rc = DISCARD; else - { - rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg, - &log_msg); - if (rc == OK && !pipelining_advertised && !check_sync()) - goto SYNC_FAILURE; - } - - /* The ACL was happy */ - - if (rc == OK) - { - if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); - else smtp_user_msg(US"250", user_msg); - receive_add_recipient(recipient, -1); - } - - /* The recipient was discarded */ - - else if (rc == DISCARD) - { - if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); - else smtp_user_msg(US"250", user_msg); - rcpt_fail_count++; - discarded = TRUE; - log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> rejected RCPT %s: " - "discarded by %s ACL%s%s", host_and_ident(TRUE), - (sender_address_unrewritten != NULL)? - sender_address_unrewritten : sender_address, - smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT", - (log_msg == NULL)? US"" : US": ", - (log_msg == NULL)? US"" : log_msg); - } - - /* Either the ACL failed the address, or it was deferred. */ - - else - { - if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++; - done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg); - } - break; /* The DATA command is legal only if it follows successful MAIL FROM @@ -3697,284 +5048,366 @@ while (done <= 0) (often indicating some kind of system error), it is helpful to include it with the DATA rejection (an idea suggested by Tony Finch). */ - case DATA_CMD: - HAD(SCH_DATA); - if (!discarded && recipients_count <= 0) + case BDAT_CMD: { - if (rcpt_smtp_response_same && rcpt_smtp_response != NULL) - { - uschar *code = US"503"; - int len = Ustrlen(rcpt_smtp_response); - smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with " - "this error:"); - /* Responses from smtp_printf() will have \r\n on the end */ - if (len > 2 && rcpt_smtp_response[len-2] == '\r') - rcpt_smtp_response[len-2] = 0; - smtp_respond(code, 3, FALSE, rcpt_smtp_response); - } - if (pipelining_advertised && last_was_rcpt) - smtp_printf("503 Valid RCPT command must precede DATA\r\n"); - else - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"valid RCPT command must precede DATA"); - break; + int n; + + HAD(SCH_BDAT); + if (chunking_state != CHUNKING_OFFERED) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"BDAT command used when CHUNKING not advertised"); + break; + } + + /* grab size, endmarker */ + + if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1) + { + done = synprot_error(L_smtp_protocol_error, 501, NULL, + US"missing size for BDAT command"); + break; + } + chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0 + ? CHUNKING_LAST : CHUNKING_ACTIVE; + chunking_data_left = chunking_datasize; + DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n", + (int)chunking_state, chunking_data_left); + + f.bdat_readers_wanted = TRUE; /* FIXME: redundant vs chunking_state? */ + f.dot_ends = FALSE; + + goto DATA_BDAT; } - if (toomany && recipients_max_reject) - { - sender_address = NULL; /* This will allow a new MAIL without RSET */ - sender_address_unrewritten = NULL; - smtp_printf("554 Too many recipients\r\n"); - break; - } - - /* If there is an ACL, re-check the synchronization afterwards, since the - ACL may have delayed. */ - - if (acl_smtp_predata == NULL) rc = OK; else - { - enable_dollar_recipients = TRUE; - rc = acl_check(ACL_WHERE_PREDATA, NULL, acl_smtp_predata, &user_msg, - &log_msg); - enable_dollar_recipients = FALSE; - if (rc == OK && !check_sync()) goto SYNC_FAILURE; - } + case DATA_CMD: + HAD(SCH_DATA); + f.dot_ends = TRUE; + f.bdat_readers_wanted = FALSE; - if (rc == OK) - { - if (user_msg == NULL) - smtp_printf("354 Enter message, ending with \".\" on a line by itself\r\n"); - else smtp_user_msg(US"354", user_msg); + DATA_BDAT: /* Common code for DATA and BDAT */ +#ifndef DISABLE_PIPE_CONNECT + fl.pipe_connect_acceptable = FALSE; +#endif + if (!discarded && recipients_count <= 0) + { + if (fl.rcpt_smtp_response_same && rcpt_smtp_response) + { + uschar *code = US"503"; + int len = Ustrlen(rcpt_smtp_response); + smtp_respond(code, 3, SR_NOT_FINAL, US"All RCPT commands were rejected with " + "this error:"); + /* Responses from smtp_printf() will have \r\n on the end */ + if (len > 2 && rcpt_smtp_response[len-2] == '\r') + rcpt_smtp_response[len-2] = 0; + smtp_respond(code, 3, SR_NOT_FINAL, rcpt_smtp_response); + } + if (f.smtp_in_pipelining_advertised && last_was_rcpt) + smtp_printf("503 Valid RCPT command must precede %s\r\n", SP_NO_MORE, + smtp_names[smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)]]); + else + done = synprot_error(L_smtp_protocol_error, 503, NULL, + smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)] == SCH_DATA + ? US"valid RCPT command must precede DATA" + : US"valid RCPT command must precede BDAT"); + + if (chunking_state > CHUNKING_OFFERED) + { + bdat_push_receive_functions(); + bdat_flush_data(); + } + break; + } + + if (toomany && recipients_max_reject) + { + sender_address = NULL; /* This will allow a new MAIL without RSET */ + sender_address_unrewritten = NULL; + smtp_printf("554 Too many recipients\r\n", SP_NO_MORE); + + if (chunking_state > CHUNKING_OFFERED) + { + bdat_push_receive_functions(); + bdat_flush_data(); + } + break; + } + + if (chunking_state > CHUNKING_OFFERED) + rc = OK; /* There is no predata ACL or go-ahead output for BDAT */ + else + { + /* If there is a predata-ACL, re-check the synchronization afterwards, + since the ACL may have delayed. To handle cutthrough delivery enforce a + dummy call to get the DATA command sent. */ + + GET_OPTION("acl_smtp_predata"); + if (!acl_smtp_predata && cutthrough.cctx.sock < 0) + rc = OK; + else + { + uschar * acl = acl_smtp_predata ? acl_smtp_predata : US"accept"; + f.enable_dollar_recipients = TRUE; + rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg, + &log_msg); + f.enable_dollar_recipients = FALSE; + if (rc == OK && !check_sync()) + goto SYNC_FAILURE; + + if (rc != OK) + { /* Either the ACL failed the address, or it was deferred. */ + done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg); + break; + } + } + + if (user_msg) + smtp_user_msg(US"354", user_msg); + else + smtp_printf( + "354 Enter message, ending with \".\" on a line by itself\r\n", SP_NO_MORE); + } + + if (f.bdat_readers_wanted) + bdat_push_receive_functions(); + +#ifdef TCP_QUICKACK + if (smtp_in) /* all ACKs needed to ramp window up for bulk data */ + (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK, + US &on, sizeof(on)); +#endif done = 3; message_ended = END_NOTENDED; /* Indicate in middle of data */ - } - /* Either the ACL failed the address, or it was deferred. */ - - else - done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg); - break; + break; case VRFY_CMD: - HAD(SCH_VRFY); - rc = acl_check(ACL_WHERE_VRFY, NULL, acl_smtp_vrfy, &user_msg, &log_msg); - if (rc != OK) - done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg); - else { - uschar *address; - uschar *s = NULL; - - /* rfc821_domains = TRUE; << no longer needed */ - address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end, - &recipient_domain, FALSE); - /* rfc821_domains = FALSE; << no longer needed */ - - if (address == NULL) - s = string_sprintf("501 %s", errmess); + uschar * address; + + HAD(SCH_VRFY); + + if (!(address = parse_extract_address(smtp_cmd_data, &errmess, + &start, &end, &recipient_domain, FALSE))) + { + smtp_printf("501 %s\r\n", SP_NO_MORE, errmess); + break; + } + + if (!recipient_domain) + if (!(recipient_domain = qualify_recipient(&address, smtp_cmd_data, + US"verify"))) + break; + + GET_OPTION("acl_smtp_vrfy"); + if ((rc = acl_check(ACL_WHERE_VRFY, address, acl_smtp_vrfy, + &user_msg, &log_msg)) != OK) + done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg); else - { - address_item *addr = deliver_make_addr(address, FALSE); - switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1, - -1, -1, NULL, NULL, NULL)) - { - case OK: - s = string_sprintf("250 <%s> is deliverable", address); - break; - - case DEFER: - s = (addr->user_message != NULL)? - string_sprintf("451 <%s> %s", address, addr->user_message) : - string_sprintf("451 Cannot resolve <%s> at this time", address); - break; - - case FAIL: - s = (addr->user_message != NULL)? - string_sprintf("550 <%s> %s", address, addr->user_message) : - string_sprintf("550 <%s> is not deliverable", address); - log_write(0, LOG_MAIN, "VRFY failed for %s %s", - smtp_cmd_argument, host_and_ident(TRUE)); - break; - } - } - - smtp_printf("%s\r\n", s); - } - break; - - - case EXPN_CMD: - HAD(SCH_EXPN); - rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg); - if (rc != OK) - done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg); - else - { - BOOL save_log_testing_mode = log_testing_mode; - address_test_mode = log_testing_mode = TRUE; - (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE), - smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1, - NULL, NULL, NULL); - address_test_mode = FALSE; - log_testing_mode = save_log_testing_mode; /* true for -bh */ - } - break; - - - #ifdef SUPPORT_TLS - - case STARTTLS_CMD: - HAD(SCH_STARTTLS); - if (!tls_advertised) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"STARTTLS command used when not advertised"); + { + uschar * s = NULL; + address_item * addr = deliver_make_addr(address, FALSE); + + switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1, + -1, -1, NULL, NULL, NULL)) + { + case OK: + s = string_sprintf("250 <%s> is deliverable", address); + break; + + case DEFER: + s = (addr->user_message != NULL)? + string_sprintf("451 <%s> %s", address, addr->user_message) : + string_sprintf("451 Cannot resolve <%s> at this time", address); + break; + + case FAIL: + s = (addr->user_message != NULL)? + string_sprintf("550 <%s> %s", address, addr->user_message) : + string_sprintf("550 <%s> is not deliverable", address); + log_write(0, LOG_MAIN, "VRFY failed for %s %s", + smtp_cmd_argument, host_and_ident(TRUE)); + break; + } + + smtp_printf("%s\r\n", SP_NO_MORE, s); + } break; } - /* Apply an ACL check if one is defined */ - if (acl_smtp_starttls != NULL) - { - rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, &user_msg, - &log_msg); + case EXPN_CMD: + HAD(SCH_EXPN); + GET_OPTION("acl_smtp_expn"); + rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg); if (rc != OK) - { - done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg); - break; - } - } - - /* RFC 2487 is not clear on when this command may be sent, though it - does state that all information previously obtained from the client - must be discarded if a TLS session is started. It seems reasonble to - do an implied RSET when STARTTLS is received. */ - - incomplete_transaction_log(US"STARTTLS"); - smtp_reset(reset_point); - toomany = FALSE; - cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE; - - /* There's an attack where more data is read in past the STARTTLS command - before TLS is negotiated, then assumed to be part of the secure session - when used afterwards; we use segregated input buffers, so are not - vulnerable, but we want to note when it happens and, for sheer paranoia, - ensure that the buffer is "wiped". - Pipelining sync checks will normally have protected us too, unless disabled - by configuration. */ - - if (receive_smtp_buffered()) - { - DEBUG(D_any) - debug_printf("Non-empty input buffer after STARTTLS; naive attack?"); - if (tls_active < 0) - smtp_inend = smtp_inptr = smtp_inbuffer; - /* and if TLS is already active, tls_server_start() should fail */ - } - - /* There is nothing we value in the input buffer and if TLS is succesfully - negotiated, we won't use this buffer again; if TLS fails, we'll just read - fresh content into it. The buffer contains arbitrary content from an - untrusted remote source; eg: NOOP \r\nSTARTTLS\r\n - It seems safest to just wipe away the content rather than leave it as a - target to jump to. */ - - memset(smtp_inbuffer, 0, in_buffer_size); - - /* Attempt to start up a TLS session, and if successful, discard all - knowledge that was obtained previously. At least, that's what the RFC says, - and that's what happens by default. However, in order to work round YAEB, - there is an option to remember the esmtp state. Sigh. - - We must allow for an extra EHLO command and an extra AUTH command after - STARTTLS that don't add to the nonmail command count. */ - - if ((rc = tls_server_start(tls_require_ciphers)) == OK) - { - if (!tls_remember_esmtp) - helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE; - cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; - cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE; - if (sender_helo_name != NULL) - { - store_free(sender_helo_name); - sender_helo_name = NULL; - host_build_sender_fullhost(); /* Rebuild */ - set_process_info("handling incoming TLS connection from %s", - host_and_ident(FALSE)); - } - received_protocol = (esmtp? - protocols[pextend + pcrpted + - ((sender_host_authenticated != NULL)? pauthed : 0)] - : - protocols[pnormal + pcrpted]) - + - ((sender_host_address != NULL)? pnlocal : 0); - - sender_host_authenticated = NULL; - authenticated_id = NULL; - sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; - DEBUG(D_tls) debug_printf("TLS active\n"); - break; /* Successful STARTTLS */ - } - - /* Some local configuration problem was discovered before actually trying - to do a TLS handshake; give a temporary error. */ - - else if (rc == DEFER) - { - smtp_printf("454 TLS currently unavailable\r\n"); + done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg); + else + { + BOOL save_log_testing_mode = f.log_testing_mode; + f.address_test_mode = f.log_testing_mode = TRUE; + (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE), + smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1, + NULL, NULL, NULL); + f.address_test_mode = FALSE; + f.log_testing_mode = save_log_testing_mode; /* true for -bh */ + } break; - } - - /* Hard failure. Reject everything except QUIT or closed connection. One - cause for failure is a nested STARTTLS, in which case tls_active remains - set, but we must still reject all incoming commands. */ - DEBUG(D_tls) debug_printf("TLS failed to start\n"); - while (done <= 0) - { - switch(smtp_read_command(FALSE)) - { - case EOF_CMD: - log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF", - smtp_get_connection_info()); - smtp_notquit_exit(US"tls-failed", NULL, NULL); - done = 2; - break; - /* It is perhaps arguable as to which exit ACL should be called here, - but as it is probably a situtation that almost never arises, it - probably doesn't matter. We choose to call the real QUIT ACL, which in - some sense is perhaps "right". */ + #ifndef DISABLE_TLS - case QUIT_CMD: - user_msg = NULL; - if (acl_smtp_quit != NULL) - { - rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, - &log_msg); - if (rc == ERROR) - log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", - log_msg); - } - if (user_msg == NULL) - smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); - else - smtp_respond(US"221", 3, TRUE, user_msg); - log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", - smtp_get_connection_info()); - done = 2; - break; - - default: - smtp_printf("554 Security failure\r\n"); - break; - } - } - tls_close(TRUE); - break; + case STARTTLS_CMD: + HAD(SCH_STARTTLS); + if (!fl.tls_advertised) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"STARTTLS command used when not advertised"); + break; + } + + /* Apply an ACL check if one is defined */ + + GET_OPTION("acl_smtp_starttls"); + if ( acl_smtp_starttls + && (rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, + &user_msg, &log_msg)) != OK + ) + { + done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg); + break; + } + + /* RFC 2487 is not clear on when this command may be sent, though it + does state that all information previously obtained from the client + must be discarded if a TLS session is started. It seems reasonable to + do an implied RSET when STARTTLS is received. */ + + incomplete_transaction_log(US"STARTTLS"); + cancel_cutthrough_connection(TRUE, US"STARTTLS received"); + reset_point = smtp_reset(reset_point); + toomany = FALSE; + cmd_list[CL_STLS].is_mail_cmd = FALSE; + + /* There's an attack where more data is read in past the STARTTLS command + before TLS is negotiated, then assumed to be part of the secure session + when used afterwards; we use segregated input buffers, so are not + vulnerable, but we want to note when it happens and, for sheer paranoia, + ensure that the buffer is "wiped". + Pipelining sync checks will normally have protected us too, unless disabled + by configuration. */ + + if (receive_hasc()) + { + DEBUG(D_any) + debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n"); + if (tls_in.active.sock < 0) + smtp_inend = smtp_inptr = smtp_inbuffer; + /* and if TLS is already active, tls_server_start() should fail */ + } + + /* There is nothing we value in the input buffer and if TLS is successfully + negotiated, we won't use this buffer again; if TLS fails, we'll just read + fresh content into it. The buffer contains arbitrary content from an + untrusted remote source; eg: NOOP \r\nSTARTTLS\r\n + It seems safest to just wipe away the content rather than leave it as a + target to jump to. */ + + memset(smtp_inbuffer, 0, IN_BUFFER_SIZE); + + /* Attempt to start up a TLS session, and if successful, discard all + knowledge that was obtained previously. At least, that's what the RFC says, + and that's what happens by default. However, in order to work round YAEB, + there is an option to remember the esmtp state. Sigh. + + We must allow for an extra EHLO command and an extra AUTH command after + STARTTLS that don't add to the nonmail command count. */ + + s = NULL; + if ((rc = tls_server_start(&s)) == OK) + { + if (!tls_remember_esmtp) + fl.helo_seen = fl.esmtp = fl.auth_advertised = f.smtp_in_pipelining_advertised = FALSE; + cmd_list[CL_EHLO].is_mail_cmd = TRUE; + cmd_list[CL_AUTH].is_mail_cmd = TRUE; + cmd_list[CL_TLAU].is_mail_cmd = TRUE; + if (sender_helo_name) + { + sender_helo_name = NULL; + host_build_sender_fullhost(); /* Rebuild */ + set_process_info("handling incoming TLS connection from %s", + host_and_ident(FALSE)); + } + received_protocol = + (sender_host_address ? protocols : protocols_local) + [ (fl.esmtp + ? pextend + (sender_host_authenticated ? pauthed : 0) + : pnormal) + + (tls_in.active.sock >= 0 ? pcrpted : 0) + ]; + + sender_host_auth_pubname = sender_host_authenticated = NULL; + authenticated_id = NULL; + sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; + DEBUG(D_tls) debug_printf("TLS active\n"); + break; /* Successful STARTTLS */ + } + else + (void) smtp_log_tls_fail(s); + + /* Some local configuration problem was discovered before actually trying + to do a TLS handshake; give a temporary error. */ + + if (rc == DEFER) + { + smtp_printf("454 TLS currently unavailable\r\n", SP_NO_MORE); + break; + } + + /* Hard failure. Reject everything except QUIT or closed connection. One + cause for failure is a nested STARTTLS, in which case tls_in.active remains + set, but we must still reject all incoming commands. Another is a handshake + failure - and there may some encrypted data still in the pipe to us, which we + see as garbage commands. */ + + DEBUG(D_tls) debug_printf("TLS failed to start\n"); + while (done <= 0) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED)) + { + case EOF_CMD: + log_close_event(US"by EOF"); + smtp_notquit_exit(US"tls-failed", NULL, NULL); + done = 2; + break; + + /* It is perhaps arguable as to which exit ACL should be called here, + but as it is probably a situation that almost never arises, it + probably doesn't matter. We choose to call the real QUIT ACL, which in + some sense is perhaps "right". */ + + case QUIT_CMD: + f.smtp_in_quit = TRUE; + user_msg = NULL; + GET_OPTION("acl_smtp_quit"); + if ( acl_smtp_quit + && ((rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, + &log_msg)) == ERROR)) + log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", + log_msg); + if (user_msg) + smtp_respond(US"221", 3, SR_FINAL, user_msg); + else + smtp_printf("221 %s closing connection\r\n", SP_NO_MORE, smtp_active_hostname); + log_close_event(US"by QUIT"); + done = 2; + break; + + default: + smtp_printf("554 Security failure\r\n", SP_NO_MORE); + break; + } + tls_close(NULL, TLS_SHUTDOWN_NOWAIT); + break; #endif @@ -3983,44 +5416,23 @@ while (done <= 0) message. */ case QUIT_CMD: - HAD(SCH_QUIT); - incomplete_transaction_log(US"QUIT"); - if (acl_smtp_quit != NULL) - { - rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg); - if (rc == ERROR) - log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", - log_msg); - } - if (user_msg == NULL) - smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); - else - smtp_respond(US"221", 3, TRUE, user_msg); - - #ifdef SUPPORT_TLS - tls_close(TRUE); - #endif - - done = 2; - log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", - smtp_get_connection_info()); - break; + smtp_quit_handler(&user_msg, &log_msg); + done = 2; + break; case RSET_CMD: - HAD(SCH_RSET); - incomplete_transaction_log(US"RSET"); - smtp_reset(reset_point); - toomany = FALSE; - smtp_printf("250 Reset OK\r\n"); - cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE; - break; + smtp_rset_handler(); + cancel_cutthrough_connection(TRUE, US"RSET received"); + reset_point = smtp_reset(reset_point); + toomany = FALSE; + break; case NOOP_CMD: - HAD(SCH_NOOP); - smtp_printf("250 OK\r\n"); - break; + HAD(SCH_NOOP); + smtp_printf("250 OK\r\n", SP_NO_MORE); + break; /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually @@ -4029,273 +5441,296 @@ while (done <= 0) response. */ case HELP_CMD: - HAD(SCH_HELP); - smtp_printf("214-Commands supported:\r\n"); - { - uschar buffer[256]; - buffer[0] = 0; - Ustrcat(buffer, " AUTH"); - #ifdef SUPPORT_TLS - if (tls_active < 0 && - verify_check_host(&tls_advertise_hosts) != FAIL) - Ustrcat(buffer, " STARTTLS"); - #endif - Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA"); - Ustrcat(buffer, " NOOP QUIT RSET HELP"); - if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN"); - if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN"); - if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY"); - smtp_printf("214%s\r\n", buffer); - } - break; - - - case EOF_CMD: - incomplete_transaction_log(US"connection lost"); - smtp_notquit_exit(US"connection-lost", US"421", - US"%s lost input connection", smtp_active_hostname); - - /* Don't log by default unless in the middle of a message, as some mailers - just drop the call rather than sending QUIT, and it clutters up the logs. - */ - - if (sender_address != NULL || recipients_count > 0) - log_write(L_lost_incoming_connection, - LOG_MAIN, - "unexpected %s while reading SMTP command from %s%s", - sender_host_unknown? "EOF" : "disconnection", - host_and_ident(FALSE), smtp_read_error); - - else log_write(L_smtp_connection, LOG_MAIN, "%s lost%s", - smtp_get_connection_info(), smtp_read_error); - - done = 1; - break; - - - case ETRN_CMD: - HAD(SCH_ETRN); - if (sender_address != NULL) - { - done = synprot_error(L_smtp_protocol_error, 503, NULL, - US"ETRN is not permitted inside a transaction"); - break; - } - - log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument, - host_and_ident(FALSE)); - - rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, &user_msg, &log_msg); - if (rc != OK) - { - done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg); - break; - } - - /* Compute the serialization key for this command. */ - - etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data); - - /* If a command has been specified for running as a result of ETRN, we - permit any argument to ETRN. If not, only the # standard form is permitted, - since that is strictly the only kind of ETRN that can be implemented - according to the RFC. */ - - if (smtp_etrn_command != NULL) - { - uschar *error; - BOOL rc; - etrn_command = smtp_etrn_command; - deliver_domain = smtp_cmd_data; - rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL, - US"ETRN processing", &error); - deliver_domain = NULL; - if (!rc) - { - log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s", - error); - smtp_printf("458 Internal failure\r\n"); - break; - } - } - - /* Else set up to call Exim with the -R option. */ - - else - { - if (*smtp_cmd_data++ != '#') - { - done = synprot_error(L_smtp_syntax_error, 501, NULL, - US"argument must begin with #"); - break; - } - etrn_command = US"exim -R"; - argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R", - smtp_cmd_data); - } - - /* If we are host-testing, don't actually do anything. */ - - if (host_checking) - { - HDEBUG(D_any) - { - debug_printf("ETRN command is: %s\n", etrn_command); - debug_printf("ETRN command execution skipped\n"); - } - if (user_msg == NULL) smtp_printf("250 OK\r\n"); - else smtp_user_msg(US"250", user_msg); + HAD(SCH_HELP); + smtp_printf("214-Commands supported:\r\n214", SP_MORE); + smtp_printf(" AUTH", SP_MORE); +#ifndef DISABLE_TLS + if (tls_in.active.sock < 0 && + verify_check_host(&tls_advertise_hosts) != FAIL) + smtp_printf(" STARTTLS", SP_MORE); +#endif + smtp_printf(" HELO EHLO MAIL RCPT DATA BDAT", SP_MORE); + smtp_printf(" NOOP QUIT RSET HELP", SP_MORE); + if (acl_smtp_etrn) smtp_printf(" ETRN", SP_MORE); + if (acl_smtp_expn) smtp_printf(" EXPN", SP_MORE); + if (acl_smtp_vrfy) smtp_printf(" VRFY", SP_MORE); +#ifdef EXPERIMENTAL_XCLIENT + if (proxy_session || verify_check_host(&hosts_xclient) != FAIL) + smtp_printf(" XCLIENT", SP_MORE); +#endif + smtp_printf("\r\n", SP_NO_MORE); break; - } - /* If ETRN queue runs are to be serialized, check the database to - ensure one isn't already running. */ + case EOF_CMD: + incomplete_transaction_log(US"connection lost"); + smtp_notquit_exit(US"connection-lost", US"421", + US"%s lost input connection", smtp_active_hostname); + + /* Don't log by default unless in the middle of a message, as some mailers + just drop the call rather than sending QUIT, and it clutters up the logs. + */ + + if (sender_address || recipients_count > 0) + log_write(L_lost_incoming_connection, LOG_MAIN, + "unexpected %s while reading SMTP command from %s%s%s D=%s", + f.sender_host_unknown ? "EOF" : "disconnection", + f.tcp_in_fastopen_logged + ? US"" + : f.tcp_in_fastopen + ? f.tcp_in_fastopen_data ? US"TFO* " : US"TFO " + : US"", + host_and_ident(FALSE), smtp_read_error, + string_timesince(&smtp_connection_start) + ); - if (smtp_etrn_serialize && !enq_start(etrn_serialize_key)) - { - smtp_printf("458 Already processing %s\r\n", smtp_cmd_data); + else + log_write(L_smtp_connection, LOG_MAIN, "%s %slost%s D=%s", + smtp_get_connection_info(), + f.tcp_in_fastopen && !f.tcp_in_fastopen_logged ? US"TFO " : US"", + smtp_read_error, + string_timesince(&smtp_connection_start) + ); + + done = 1; break; - } - - /* Fork a child process and run the command. We don't want to have to - wait for the process at any point, so set SIGCHLD to SIG_IGN before - forking. It should be set that way anyway for external incoming SMTP, - but we save and restore to be tidy. If serialization is required, we - actually run the command in yet another process, so we can wait for it - to complete and then remove the serialization lock. */ - - oldsignal = signal(SIGCHLD, SIG_IGN); - - if ((pid = fork()) == 0) - { - smtp_input = FALSE; /* This process is not associated with the */ - (void)fclose(smtp_in); /* SMTP call any more. */ - (void)fclose(smtp_out); - signal(SIGCHLD, SIG_DFL); /* Want to catch child */ - /* If not serializing, do the exec right away. Otherwise, fork down - into another process. */ - - if (!smtp_etrn_serialize || (pid = fork()) == 0) - { - DEBUG(D_exec) debug_print_argv(argv); - exim_nullstd(); /* Ensure std{in,out,err} exist */ - execv(CS argv[0], (char *const *)argv); - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s", - etrn_command, strerror(errno)); - _exit(EXIT_FAILURE); /* paranoia */ - } + case ETRN_CMD: + HAD(SCH_ETRN); + if (sender_address) + { + done = synprot_error(L_smtp_protocol_error, 503, NULL, + US"ETRN is not permitted inside a transaction"); + break; + } + + log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument, + host_and_ident(FALSE)); + + GET_OPTION("acl_smtp_etrn"); + if ((rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, + &user_msg, &log_msg)) != OK) + { + done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg); + break; + } + + /* Compute the serialization key for this command. */ + + etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data); + + /* If a command has been specified for running as a result of ETRN, we + permit any argument to ETRN. If not, only the # standard form is permitted, + since that is strictly the only kind of ETRN that can be implemented + according to the RFC. */ + + GET_OPTION("smtp_etrn_command"); + if (smtp_etrn_command) + { + uschar *error; + BOOL rc; + etrn_command = smtp_etrn_command; + deliver_domain = smtp_cmd_data; + rc = transport_set_up_command(&argv, smtp_etrn_command, TSUC_EXPAND_ARGS, 0, NULL, + US"ETRN processing", &error); + deliver_domain = NULL; + if (!rc) + { + log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s", + error); + smtp_printf("458 Internal failure\r\n", SP_NO_MORE); + break; + } + } + + /* Else set up to call Exim with the -R option. */ - /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That - is, we are in the first subprocess, after forking again. All we can do - for a failing fork is to log it. Otherwise, wait for the 2nd process to - complete, before removing the serialization. */ + else + { + if (*smtp_cmd_data++ != '#') + { + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"argument must begin with #"); + break; + } + etrn_command = US"exim -R"; + argv = CUSS child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, + *queue_name ? 4 : 2, + US"-R", smtp_cmd_data, + US"-MCG", queue_name); + } + + /* If we are host-testing, don't actually do anything. */ + + if (host_checking) + { + HDEBUG(D_any) + { + debug_printf("ETRN command is: %s\n", etrn_command); + debug_printf("ETRN command execution skipped\n"); + } + if (user_msg == NULL) smtp_printf("250 OK\r\n", SP_NO_MORE); + else smtp_user_msg(US"250", user_msg); + break; + } + + + /* If ETRN queue runs are to be serialized, check the database to + ensure one isn't already running. */ + + if (smtp_etrn_serialize && !enq_start(etrn_serialize_key, 1)) + { + smtp_printf("458 Already processing %s\r\n", SP_NO_MORE, smtp_cmd_data); + break; + } + + /* Fork a child process and run the command. We don't want to have to + wait for the process at any point, so set SIGCHLD to SIG_IGN before + forking. It should be set that way anyway for external incoming SMTP, + but we save and restore to be tidy. If serialization is required, we + actually run the command in yet another process, so we can wait for it + to complete and then remove the serialization lock. */ + + oldsignal = signal(SIGCHLD, SIG_IGN); + + if ((pid = exim_fork(US"etrn-command")) == 0) + { + smtp_input = FALSE; /* This process is not associated with the */ + (void)fclose(smtp_in); /* SMTP call any more. */ + (void)fclose(smtp_out); + + signal(SIGCHLD, SIG_DFL); /* Want to catch child */ + + /* If not serializing, do the exec right away. Otherwise, fork down + into another process. */ + + if ( !smtp_etrn_serialize + || (pid = exim_fork(US"etrn-serialised-command")) == 0) + { + DEBUG(D_exec) debug_print_argv(argv); + exim_nullstd(); /* Ensure std{in,out,err} exist */ + /* argv[0] should be untainted, from child_exec_exim() */ + execv(CS argv[0], (char *const *)argv); + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s", + etrn_command, strerror(errno)); + _exit(EXIT_FAILURE); /* paranoia */ + } + + /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That + is, we are in the first subprocess, after forking again. All we can do + for a failing fork is to log it. Otherwise, wait for the 2nd process to + complete, before removing the serialization. */ + + if (pid < 0) + log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN " + "failed: %s", strerror(errno)); + else + { + int status; + DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n", + (int)pid); + (void)wait(&status); + DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n", + (int)pid); + } + + enq_end(etrn_serialize_key); + exim_underbar_exit(EXIT_SUCCESS); + } + + /* Back in the top level SMTP process. Check that we started a subprocess + and restore the signal state. */ if (pid < 0) - log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN " - "failed: %s", strerror(errno)); + { + log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s", + strerror(errno)); + smtp_printf("458 Unable to fork process\r\n", SP_NO_MORE); + if (smtp_etrn_serialize) enq_end(etrn_serialize_key); + } else - { - int status; - DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n", - (int)pid); - (void)wait(&status); - DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n", - (int)pid); - } - - enq_end(etrn_serialize_key); - _exit(EXIT_SUCCESS); - } - - /* Back in the top level SMTP process. Check that we started a subprocess - and restore the signal state. */ - - if (pid < 0) - { - log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s", - strerror(errno)); - smtp_printf("458 Unable to fork process\r\n"); - if (smtp_etrn_serialize) enq_end(etrn_serialize_key); - } - else - { - if (user_msg == NULL) smtp_printf("250 OK\r\n"); - else smtp_user_msg(US"250", user_msg); - } + if (!user_msg) + smtp_printf("250 OK\r\n", SP_NO_MORE); + else + smtp_user_msg(US"250", user_msg); - signal(SIGCHLD, oldsignal); - break; + signal(SIGCHLD, oldsignal); + break; case BADARG_CMD: - done = synprot_error(L_smtp_syntax_error, 501, NULL, - US"unexpected argument data"); - break; + done = synprot_error(L_smtp_syntax_error, 501, NULL, + US"unexpected argument data"); + break; /* This currently happens only for NULLs, but could be extended. */ case BADCHAR_CMD: - done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */ - US"NULL character(s) present (shown as '?')"); - smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n"); - break; + done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */ + US"NUL character(s) present (shown as '?')"); + smtp_printf("501 NUL characters are not allowed in SMTP commands\r\n", + SP_NO_MORE); + break; case BADSYN_CMD: SYNC_FAILURE: - if (smtp_inend >= smtp_inbuffer + in_buffer_size) - smtp_inend = smtp_inbuffer + in_buffer_size - 1; - c = smtp_inend - smtp_inptr; - if (c > 150) c = 150; - smtp_inptr[c] = 0; - incomplete_transaction_log(US"sync failure"); - log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error " - "(next input sent too soon: pipelining was%s advertised): " - "rejected \"%s\" %s next input=\"%s\"", - pipelining_advertised? "" : " not", - smtp_cmd_buffer, host_and_ident(TRUE), - string_printing(smtp_inptr)); - smtp_notquit_exit(US"synchronization-error", US"554", - US"SMTP synchronization error"); - done = 1; /* Pretend eof - drops connection */ - break; + { + unsigned nchars = 150; + uschar * buf = receive_getbuf(&nchars); /* destructive read */ + buf[nchars] = '\0'; + incomplete_transaction_log(US"sync failure"); + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error " + "(next input sent too soon: pipelining was%s advertised): " + "rejected \"%s\" %s next input=\"%s\" (%u bytes)", + f.smtp_in_pipelining_advertised ? "" : " not", + smtp_cmd_buffer, host_and_ident(TRUE), + string_printing(buf), nchars); + smtp_notquit_exit(US"synchronization-error", US"554", + US"SMTP synchronization error"); + done = 1; /* Pretend eof - drops connection */ + break; + } case TOO_MANY_NONMAIL_CMD: - s = smtp_cmd_buffer; - while (*s != 0 && !isspace(*s)) s++; - incomplete_transaction_log(US"too many non-mail commands"); - log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " - "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE), - s - smtp_cmd_buffer, smtp_cmd_buffer); - smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands"); - done = 1; /* Pretend eof - drops connection */ - break; + s = smtp_cmd_buffer; + Uskip_nonwhite(&s); + incomplete_transaction_log(US"too many non-mail commands"); + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " + "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE), + (int)(s - smtp_cmd_buffer), smtp_cmd_buffer); + smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands"); + done = 1; /* Pretend eof - drops connection */ + break; +#ifdef SUPPORT_PROXY + case PROXY_FAIL_IGNORE_CMD: + smtp_printf("503 Command refused, required Proxy negotiation failed\r\n", SP_NO_MORE); + break; +#endif default: - if (unknown_command_count++ >= smtp_max_unknown_commands) - { - log_write(L_smtp_syntax_error, LOG_MAIN, - "SMTP syntax error in \"%s\" %s %s", - string_printing(smtp_cmd_buffer), host_and_ident(TRUE), - US"unrecognized command"); - incomplete_transaction_log(US"unrecognized command"); - smtp_notquit_exit(US"bad-commands", US"500", - US"Too many unrecognized commands"); - done = 2; - log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " - "unrecognized commands (last was \"%s\")", host_and_ident(FALSE), - smtp_cmd_buffer); - } - else - done = synprot_error(L_smtp_syntax_error, 500, NULL, - US"unrecognized command"); - break; + if (unknown_command_count++ >= smtp_max_unknown_commands) + { + log_write(L_smtp_syntax_error, LOG_MAIN, + "SMTP syntax error in \"%s\" %s %s", + string_printing(smtp_cmd_buffer), host_and_ident(TRUE), + US"unrecognized command"); + incomplete_transaction_log(US"unrecognized command"); + smtp_notquit_exit(US"bad-commands", US"500", + US"Too many unrecognized commands"); + done = 2; + log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " + "unrecognized commands (last was \"%s\")", host_and_ident(FALSE), + string_printing(smtp_cmd_buffer)); + } + else + done = synprot_error(L_smtp_syntax_error, 500, NULL, + US"unrecognized command"); + break; } /* This label is used by goto's inside loops that want to break out to @@ -4304,10 +5739,37 @@ while (done <= 0) COMMAND_LOOP: last_was_rej_mail = was_rej_mail; /* Remember some last commands for */ last_was_rcpt = was_rcpt; /* protocol error handling */ - continue; } return done - 2; /* Convert yield values */ } + + +gstring * +authres_smtpauth(gstring * g) +{ +if (!sender_host_authenticated) + return g; + +g = string_append(g, 2, US";\n\tauth=pass (", sender_host_auth_pubname); + +if (Ustrcmp(sender_host_auth_pubname, "tls") == 0) + g = authenticated_id + ? string_append(g, 2, US") x509.auth=", authenticated_id) + : string_cat(g, US") reason=x509.auth"); +else + g = authenticated_id + ? string_append(g, 2, US") smtp.auth=", authenticated_id) + : string_cat(g, US", no id saved)"); + +if (authenticated_sender) + g = string_append(g, 2, US" smtp.mailfrom=", authenticated_sender); +return g; +} + + + +/* vi: aw ai sw=2 +*/ /* End of smtp_in.c */