X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/9f84d5d5eb8d2f15f9bef6d4d662a4dc5f17219c..ef2e5890df09193717f9d345ffaaa406e2d8aae7:/src/src/smtp_in.c diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c index 2bb15b698..a48fac605 100644 --- a/src/src/smtp_in.c +++ b/src/src/smtp_in.c @@ -3,7 +3,7 @@ *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2018 */ -/* Copyright (c) The Exim Maintainers 2020 */ +/* Copyright (c) The Exim Maintainers 2020 - 2021 */ /* See the file NOTICE for conditions of use and distribution. */ /* Functions for handling an incoming SMTP call. */ @@ -139,7 +139,7 @@ static struct { #endif BOOL dsn_advertised :1; BOOL esmtp :1; - BOOL helo_required :1; + BOOL helo_verify_required :1; BOOL helo_verify :1; BOOL helo_seen :1; BOOL helo_accept_junk :1; @@ -153,7 +153,7 @@ static struct { BOOL smtputf8_advertised :1; #endif } fl = { - .helo_required = FALSE, + .helo_verify_required = FALSE, .helo_verify = FALSE, .smtp_exit_function_called = FALSE, }; @@ -319,96 +319,6 @@ 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); -/************************************************* -* Recheck synchronization * -*************************************************/ - -/* 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. - -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 -wouldblock_reading(void) -{ -int fd, rc; -fd_set fds; -struct timeval tzero = {.tv_sec = 0, .tv_usec = 0}; - -#ifndef DISABLE_TLS -if (tls_in.active.sock >= 0) - return !tls_could_read(); -#endif - -if (smtp_inptr < smtp_inend) - return FALSE; - -fd = fileno(smtp_in); -FD_ZERO(&fds); -FD_SET(fd, &fds); -rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); - -if (rc <= 0) return TRUE; /* Not ready to read */ -rc = smtp_getc(GETC_BUFFER_UNLIMITED); -if (rc < 0) return TRUE; /* End of file or error */ - -smtp_ungetc(rc); -return FALSE; -} - -static BOOL -check_sync(void) -{ -if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket) - return TRUE; - -return wouldblock_reading(); -} - - -/* 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 - /************************************************* * Log incomplete transactions * *************************************************/ @@ -491,6 +401,25 @@ receive_bomb_out(US"signal-exit", } +/******************************************************************************/ +/* 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. @@ -500,6 +429,7 @@ static BOOL smtp_refill(unsigned lim) { int rc, save_errno; + if (!smtp_out) return FALSE; fflush(smtp_out); if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); @@ -541,11 +471,18 @@ smtp_inptr = smtp_inbuffer; return TRUE; } -/************************************************* -* SMTP version of getc() * -*************************************************/ -/* This gets the next byte from the SMTP input buffer. If the buffer is empty, +/* 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. @@ -557,21 +494,20 @@ Returns: the next character or EOF int smtp_getc(unsigned lim) { -if (smtp_inptr >= smtp_inend) - if (!smtp_refill(lim)) - return EOF; +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_inptr >= smtp_inend) - if (!smtp_refill(*len)) - { *len = 0; return NULL; } +if (!smtp_hasc() && !smtp_refill(*len)) + { *len = 0; return NULL; } if ((size = smtp_inend - smtp_inptr) > *len) size = *len; buf = smtp_inptr; @@ -580,19 +516,151 @@ smtp_inptr += size; return buf; } +/* Copy buffered data to the dkim feed. +Called, unless TLS, just before starting to read message headers. */ + void -smtp_get_cache(void) +smtp_get_cache(unsigned lim) { #ifndef DISABLE_DKIM int n = smtp_inend - smtp_inptr; -if (chunking_state == CHUNKING_LAST && chunking_data_left < n) - n = chunking_data_left; +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. + +Arguments: + ch the character + +Returns: the character +*/ + +int +smtp_ungetc(int 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 + +Arguments: none +Returns: non-zero if the eof flag is set +*/ + +int +smtp_feof(void) +{ +return smtp_had_eof; +} + + +/* 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 +Returns: non-zero if the error flag is set +*/ + +int +smtp_ferror(void) +{ +errno = smtp_had_error; +return smtp_had_error; +} + + +/* Check if a getc will block or not */ + +static BOOL +smtp_could_getc(void) +{ +int fd, rc; +fd_set fds; +struct timeval tzero = {.tv_sec = 0, .tv_usec = 0}; + +if (smtp_inptr < smtp_inend) + return TRUE; + +fd = fileno(smtp_in); +FD_ZERO(&fds); +FD_SET(fd, &fds); +rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); + +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; +} + + +/******************************************************************************/ +/************************************************* +* Recheck synchronization * +*************************************************/ + +/* 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. + +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 +wouldblock_reading(void) +{ +#ifndef DISABLE_TLS +if (tls_in.active.sock >= 0) + return !tls_could_getc(); +#endif + +return !smtp_could_getc(); +} + +static BOOL +check_sync(void) +{ +if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket) + return TRUE; + +return wouldblock_reading(); +} + + +/******************************************************************************/ +/* Variants of the smtp_* input handling functions for use in CHUNKING mode */ + +/* Forward declarations */ +static inline void bdat_push_receive_functions(void); +static inline void bdat_pop_receive_functions(void); + + /* 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 @@ -624,9 +692,7 @@ for(;;) if (chunking_data_left > 0) return lwr_receive_getc(chunking_data_left--); - receive_getc = lwr_receive_getc; - receive_getbuf = lwr_receive_getbuf; - receive_ungetc = lwr_receive_ungetc; + bdat_pop_receive_functions(); #ifndef DISABLE_DKIM dkim_save = dkim_collect_input; dkim_collect_input = 0; @@ -658,7 +724,9 @@ for(;;) 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; } @@ -730,9 +798,7 @@ next_cmd: goto repeat_until_rset; } - receive_getc = bdat_getc; - receive_getbuf = bdat_getbuf; /* r~getbuf is never actually used */ - receive_ungetc = bdat_ungetc; + bdat_push_receive_functions(); #ifndef DISABLE_DKIM dkim_collect_input = dkim_save; #endif @@ -742,6 +808,14 @@ next_cmd: } } +BOOL +bdat_hasc(void) +{ +if (chunking_data_left > 0) + return lwr_receive_hasc(); +return TRUE; +} + uschar * bdat_getbuf(unsigned * len) { @@ -765,9 +839,7 @@ while (chunking_data_left) if (!bdat_getbuf(&n)) break; } -receive_getc = lwr_receive_getc; -receive_getbuf = lwr_receive_getbuf; -receive_ungetc = lwr_receive_ungetc; +bdat_pop_receive_functions(); if (chunking_state != CHUNKING_LAST) { @@ -777,94 +849,60 @@ if (chunking_state != CHUNKING_LAST) } +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; +} -/************************************************* -* SMTP version of ungetc() * -*************************************************/ - -/* Puts a character back in the input buffer. Only ever -called once. - -Arguments: - ch the character - -Returns: the character -*/ - -int -smtp_ungetc(int ch) +static inline void +bdat_pop_receive_functions(void) { -*--smtp_inptr = ch; -return ch; -} +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); } -/************************************************* -* SMTP version of feof() * -*************************************************/ - -/* Tests for a previous EOF - -Arguments: none -Returns: non-zero if the eof flag is set -*/ - -int -smtp_feof(void) -{ -return smtp_had_eof; -} - - - - -/************************************************* -* 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 -Returns: non-zero if the error flag is set -*/ - -int -smtp_ferror(void) -{ -errno = smtp_had_error; -return smtp_had_error; -} - - - -/************************************************* -* Test for characters in the SMTP buffer * -*************************************************/ - -/* Used at the end of a message - -Arguments: none -Returns: TRUE/FALSE -*/ - -BOOL -smtp_buffered(void) -{ -return smtp_inptr < smtp_inend; -} - - +/******************************************************************************/ /************************************************* * Write formatted string to SMTP channel * @@ -994,6 +1032,35 @@ 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 * *************************************************/ @@ -1615,12 +1682,13 @@ for (smtp_cmd_list * p = cmd_list; p < cmd_list_end; p++) || 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 */ - !f.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 @@ -1669,7 +1737,8 @@ 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 */ + && !f.sender_host_notsocket /* Really is a socket */ + ) return BADSYN_CMD; return OTHER_CMD; @@ -1967,29 +2036,35 @@ 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)) { /* Take care to not stop at a space embedded in a quoted local-part */ - - if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1); + 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; if (*v == '=') { - while(isalpha(n[-1])) n--; + while (n > smtp_cmd_data && isalpha(n[-1])) n--; /* RFC says SP, but TAB seen in wild and other major MTAs accept it */ - if (!isspace(n[-1])) return FALSE; + if (n <= smtp_cmd_data || !isspace(n[-1])) return FALSE; n[-1] = 0; } else { n++; - if (v == smtp_cmd_data) return FALSE; } *v++ = 0; *name = n; @@ -2205,9 +2280,11 @@ while (done <= 0) /* 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; + 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 */ @@ -2227,7 +2304,8 @@ while (done <= 0) && sender_address[0] != 0 && sender_address[0] != '@') if (f.allow_unqualified_sender) { - sender_address = rewrite_address_qualify(sender_address, FALSE); + /* 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); } @@ -2266,7 +2344,8 @@ while (done <= 0) recipient address */ recipient = rewrite_existflags & rewrite_smtp - ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + /* 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; @@ -2285,7 +2364,8 @@ while (done <= 0) { DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", recipient); - recipient = rewrite_address_qualify(recipient, TRUE); + /* deconst ok as recipient was not const */ + recipient = US rewrite_address_qualify(recipient, TRUE); } /* The function moan_smtp_batch() does not return. */ else @@ -2362,9 +2442,9 @@ return done - 2; /* Convert yield values */ #ifndef DISABLE_TLS static BOOL -smtp_log_tls_fail(uschar * errstr) +smtp_log_tls_fail(const uschar * errstr) { -uschar * conn_info = smtp_get_connection_info(); +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 */ @@ -2513,22 +2593,21 @@ else (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. Place a NUL at the -end of the buffer to safety-stop C-string reads from it. */ +call the local functions instead of the standard C ones. */ -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_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 */ @@ -2882,8 +2961,8 @@ if (!f.sender_host_unknown) /* Determine whether HELO/EHLO is required for this host. The requirement can be hard or soft. */ - fl.helo_required = verify_check_host(&helo_verify_hosts) == OK; - if (!fl.helo_required) + 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 @@ -2961,7 +3040,7 @@ else 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 @@ -3141,7 +3220,7 @@ which sometimes uses smtp_printf() and sometimes smtp_respond(). */ if (fl.rcpt_in_progress) { - if (rcpt_smtp_response == NULL) + if (!rcpt_smtp_response) rcpt_smtp_response = string_copy(msg); else if (fl.rcpt_smtp_response_same && Ustrcmp(rcpt_smtp_response, msg) != 0) @@ -3156,7 +3235,7 @@ 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", !final, code, final ? ' ':'-', esclen, esc, msg); return; @@ -3212,27 +3291,26 @@ void smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg, BOOL check_valid) { -int n; -int ovector[3]; - -if (!msg || !*msg) return; +uschar * match; +int len; -if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0, - PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return; +if (!msg || !*msg || !regex_match(regex_smtp_code, *msg, -1, &match)) + return; +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; } @@ -3812,7 +3890,8 @@ 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; - *recipient = rewrite_address_qualify(*recipient, TRUE); + /* 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", FALSE, @@ -3866,16 +3945,8 @@ log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", /* Pause, hoping client will FIN first so that they get the TIME_WAIT. The socket should become readble (though with no data) */ - { - int fd = fileno(smtp_in); - fd_set fds; - struct timeval t_limit = {.tv_sec = 0, .tv_usec = 200*1000}; - - FD_ZERO(&fds); - FD_SET(fd, &fds); - (void) select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &t_limit); - } -#endif /*!DAEMON_CLOSE_NOWAIT*/ +(void) poll_one_fd(fileno(smtp_in), POLLIN, 200); +#endif /*!SERVERSIDE_CLOSE_NOWAIT*/ } @@ -3926,7 +3997,6 @@ int smtp_setup_msg(void) { int done = 0; -int mailmax = -1; BOOL toomany = FALSE; BOOL discarded = FALSE; BOOL last_was_rej_mail = FALSE; @@ -3953,6 +4023,14 @@ cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; cmd_list[CMD_LIST_STARTTLS].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; @@ -4188,7 +4266,7 @@ while (done <= 0) /* 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 + 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. */ @@ -4216,19 +4294,19 @@ while (done <= 0) 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_required is set, + 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_required || fl.helo_verify) + if (fl.helo_verify_required || fl.helo_verify) { BOOL tempfail = !smtp_verify_helo(); if (!f.helo_verified) { - if (fl.helo_required) + if (fl.helo_verify_required) { smtp_printf("%d %s argument does not match calling host\r\n", FALSE, tempfail? 451 : 550, hello); @@ -4285,7 +4363,7 @@ while (done <= 0) #endif /* Expand the per-connection message count limit option */ - mailmax = expand_mailmax(smtp_accept_max_per_connection); + smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection); smtp_code = US"250 "; /* Default response code plus space*/ if (!user_msg) @@ -4346,6 +4424,19 @@ while (done <= 0) g = string_catn(g, US"-SIZE\r\n", 7); } +#ifdef EXPERIMENTAL_ESMTP_LIMITS + if ( (smtp_mailcmd_max > 0 || recipients_max) + && 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) + g = string_fmt_append(g, " RCPTMAX=%d", recipients_max); + g = string_catn(g, US"\r\n", 2); + } +#endif + /* 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. @@ -4563,15 +4654,16 @@ while (done <= 0) env_mail_type_t * mail_args; /* Sanity check & validate args */ if (!fl.helo_seen) - if (fl.helo_required) + if ( fl.helo_verify_required + || verify_check_host(&hosts_require_helo) == OK) { smtp_printf("503 HELO or EHLO required\r\n", FALSE); log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no " "HELO/EHLO given", host_and_ident(FALSE)); break; } - else if (mailmax < 0) - mailmax = expand_mailmax(smtp_accept_max_per_connection); + else if (smtp_mailcmd_max < 0) + smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection); if (sender_address) { @@ -4590,7 +4682,7 @@ while (done <= 0) /* Check to see if the limit for messages per connection would be exceeded by accepting further messages. */ - if (mailmax > 0 && smtp_mailcmd_count > mailmax) + if (smtp_mailcmd_max > 0 && smtp_mailcmd_count > smtp_mailcmd_max) { smtp_printf("421 too many messages in this connection\r\n", FALSE); log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many " @@ -4842,7 +4934,8 @@ while (done <= 0) TRUE flag allows "<>" as a sender address. */ raw_sender = rewrite_existflags & rewrite_smtp - ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + /* 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; @@ -4904,7 +4997,8 @@ while (done <= 0) if (f.allow_unqualified_sender) { sender_domain = Ustrlen(sender_address) + 1; - sender_address = rewrite_address_qualify(sender_address, FALSE); + /* 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); } @@ -4974,6 +5068,10 @@ while (done <= 0) 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; @@ -5096,7 +5194,8 @@ while (done <= 0) as a recipient address */ recipient = rewrite_existflags & rewrite_smtp - ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", + /* 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; @@ -5129,7 +5228,7 @@ while (done <= 0) /* Check maximum allowed */ - if (rcpt_count > recipients_max && recipients_max > 0) + if (rcpt_count+1 < 0 || rcpt_count > recipients_max && recipients_max > 0) { if (recipients_max_reject) { @@ -5274,16 +5373,7 @@ while (done <= 0) DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n", (int)chunking_state, chunking_data_left); - /* 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. */ - lwr_receive_getc = receive_getc; - lwr_receive_getbuf = receive_getbuf; - lwr_receive_ungetc = receive_ungetc; - - receive_getc = bdat_getc; - receive_ungetc = bdat_ungetc; - + f.bdat_readers_wanted = TRUE; /* FIXME: redundant vs chunking_state? */ f.dot_ends = FALSE; goto DATA_BDAT; @@ -5292,6 +5382,7 @@ while (done <= 0) case DATA_CMD: HAD(SCH_DATA); f.dot_ends = TRUE; + f.bdat_readers_wanted = FALSE; DATA_BDAT: /* Common code for DATA and BDAT */ #ifndef DISABLE_PIPE_CONNECT @@ -5320,7 +5411,10 @@ while (done <= 0) : US"valid RCPT command must precede BDAT"); if (chunking_state > CHUNKING_OFFERED) + { + bdat_push_receive_functions(); bdat_flush_data(); + } break; } @@ -5329,6 +5423,12 @@ while (done <= 0) sender_address = NULL; /* This will allow a new MAIL without RSET */ sender_address_unrewritten = NULL; smtp_printf("554 Too many recipients\r\n", FALSE); + + if (chunking_state > CHUNKING_OFFERED) + { + bdat_push_receive_functions(); + bdat_flush_data(); + } break; } @@ -5366,6 +5466,9 @@ while (done <= 0) "354 Enter message, ending with \".\" on a line by itself\r\n", FALSE); } + 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, @@ -5490,7 +5593,7 @@ while (done <= 0) Pipelining sync checks will normally have protected us too, unless disabled by configuration. */ - if (receive_smtp_buffered()) + if (receive_hasc()) { DEBUG(D_any) debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n");