1 /* $Cambridge: exim/src/src/smtp_in.c,v 1.60 2007/08/22 10:10:23 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2007 */
8 /* See the file NOTICE for conditions of use and distribution. */
10 /* Functions for handling an incoming SMTP call. */
16 /* Initialize for TCP wrappers if so configured. It appears that the macro
17 HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
18 including that header, and restore its value afterwards. */
20 #ifdef USE_TCP_WRAPPERS
23 #define EXIM_HAVE_IPV6
29 #define HAVE_IPV6 TRUE
32 int allow_severity = LOG_INFO;
33 int deny_severity = LOG_NOTICE;
37 /* Size of buffer for reading SMTP commands. We used to use 512, as defined
38 by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39 commands that accept arguments, and this in particular applies to AUTH, where
40 the data can be quite long. */
42 #define smtp_cmd_buffer_size 2048
44 /* Size of buffer for reading SMTP incoming packets */
46 #define in_buffer_size 8192
48 /* Structure for SMTP command list */
55 short int is_mail_cmd;
58 /* Codes for identifying commands. We order them so that those that come first
59 are those for which synchronization is always required. Checking this can help
63 /* These commands are required to be synchronized, i.e. to be the last in a
64 block of commands when pipelining. */
66 HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */
67 VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
68 ETRN_CMD, /* This by analogy with TURN from the RFC */
69 STARTTLS_CMD, /* Required by the STARTTLS RFC */
71 /* This is a dummy to identify the non-sync commands when pipelining */
73 NON_SYNC_CMD_PIPELINING,
75 /* These commands need not be synchronized when pipelining */
77 MAIL_CMD, RCPT_CMD, RSET_CMD,
79 /* This is a dummy to identify the non-sync commands when not pipelining */
81 NON_SYNC_CMD_NON_PIPELINING,
83 /* I have been unable to find a statement about the use of pipelining
84 with AUTH, so to be on the safe side it is here, though I kind of feel
85 it should be up there with the synchronized commands. */
89 /* I'm not sure about these, but I don't think they matter. */
93 /* These are specials that don't correspond to actual commands */
95 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
96 TOO_MANY_NONMAIL_CMD };
99 /* This is a convenience macro for adding the identity of an SMTP command
100 to the circular buffer that holds a list of the last n received. */
103 smtp_connection_had[smtp_ch_index++] = n; \
104 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
107 /*************************************************
108 * Local static variables *
109 *************************************************/
111 static auth_instance *authenticated_by;
112 static BOOL auth_advertised;
114 static BOOL tls_advertised;
117 static BOOL helo_required = FALSE;
118 static BOOL helo_verify = FALSE;
119 static BOOL helo_seen;
120 static BOOL helo_accept_junk;
121 static BOOL count_nonmail;
122 static BOOL pipelining_advertised;
123 static BOOL rcpt_smtp_response_same;
124 static BOOL rcpt_in_progress;
125 static int nonmail_command_count;
126 static BOOL smtp_exit_function_called = 0;
127 static int synprot_error_count;
128 static int unknown_command_count;
129 static int sync_cmd_limit;
130 static int smtp_write_error = 0;
132 static uschar *rcpt_smtp_response;
133 static uschar *smtp_data_buffer;
134 static uschar *smtp_cmd_data;
136 /* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
137 final fields of all except AUTH are forced TRUE at the start of a new message
138 setup, to allow one of each between messages that is not counted as a nonmail
139 command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
140 allow a new EHLO after starting up TLS.
142 AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
143 counted. However, the flag is changed when AUTH is received, so that multiple
144 failing AUTHs will eventually hit the limit. After a successful AUTH, another
145 AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
146 forced TRUE, to allow for the re-authentication that can happen at that point.
148 QUIT is also "falsely" labelled as a mail command so that it doesn't up the
149 count of non-mail commands and possibly provoke an error. */
151 static smtp_cmd_list cmd_list[] = {
152 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
153 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
154 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
155 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
157 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
160 /* If you change anything above here, also fix the definitions below. */
162 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
163 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
164 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
165 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
166 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
167 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
168 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
169 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
170 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
173 static smtp_cmd_list *cmd_list_end =
174 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
176 #define CMD_LIST_RSET 0
177 #define CMD_LIST_HELO 1
178 #define CMD_LIST_EHLO 2
179 #define CMD_LIST_AUTH 3
180 #define CMD_LIST_STARTTLS 4
182 /* This list of names is used for performing the smtp_no_mail logging action.
183 It must be kept in step with the SCH_xxx enumerations. */
185 static uschar *smtp_names[] =
187 US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO",
188 US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS",
191 static uschar *protocols[] = {
192 US"local-smtp", /* HELO */
193 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
194 US"local-esmtp", /* EHLO */
195 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
196 US"local-esmtpa", /* EHLO->AUTH */
197 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
202 #define pcrpted 1 /* added to pextend or pnormal */
203 #define pauthed 2 /* added to pextend */
204 #define pnlocal 6 /* offset to remove "local" */
206 /* When reading SMTP from a remote host, we have to use our own versions of the
207 C input-reading functions, in order to be able to flush the SMTP output only
208 when about to read more data from the socket. This is the only way to get
209 optimal performance when the client is using pipelining. Flushing for every
210 command causes a separate packet and reply packet each time; saving all the
211 responses up (when pipelining) combines them into one packet and one response.
213 For simplicity, these functions are used for *all* SMTP input, not only when
214 receiving over a socket. However, after setting up a secure socket (SSL), input
215 is read via the OpenSSL library, and another set of functions is used instead
218 These functions are set in the receive_getc etc. variables and called with the
219 same interface as the C functions. However, since there can only ever be
220 one incoming SMTP call, we just use a single buffer and flags. There is no need
221 to implement a complicated private FILE-like structure.*/
223 static uschar *smtp_inbuffer;
224 static uschar *smtp_inptr;
225 static uschar *smtp_inend;
226 static int smtp_had_eof;
227 static int smtp_had_error;
230 /*************************************************
231 * SMTP version of getc() *
232 *************************************************/
234 /* This gets the next byte from the SMTP input buffer. If the buffer is empty,
235 it flushes the output, and refills the buffer, with a timeout. The signal
236 handler is set appropriately by the calling function. This function is not used
237 after a connection has negotated itself into an TLS/SSL state.
240 Returns: the next character or EOF
246 if (smtp_inptr >= smtp_inend)
250 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
251 rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
256 /* Must put the error text in fixed store, because this might be during
257 header reading, where it releases unused store above the header. */
260 smtp_had_error = save_errno;
261 smtp_read_error = string_copy_malloc(
262 string_sprintf(" (error: %s)", strerror(save_errno)));
264 else smtp_had_eof = 1;
267 smtp_inend = smtp_inbuffer + rc;
268 smtp_inptr = smtp_inbuffer;
270 return *smtp_inptr++;
275 /*************************************************
276 * SMTP version of ungetc() *
277 *************************************************/
279 /* Puts a character back in the input buffer. Only ever
285 Returns: the character
291 *(--smtp_inptr) = ch;
298 /*************************************************
299 * SMTP version of feof() *
300 *************************************************/
302 /* Tests for a previous EOF
305 Returns: non-zero if the eof flag is set
317 /*************************************************
318 * SMTP version of ferror() *
319 *************************************************/
321 /* Tests for a previous read error, and returns with errno
322 restored to what it was when the error was detected.
325 Returns: non-zero if the error flag is set
331 errno = smtp_had_error;
332 return smtp_had_error;
337 /*************************************************
338 * Test for characters in the SMTP buffer *
339 *************************************************/
341 /* Used at the end of a message
350 return smtp_inptr < smtp_inend;
355 /*************************************************
356 * Write formatted string to SMTP channel *
357 *************************************************/
359 /* This is a separate function so that we don't have to repeat everything for
360 TLS support or debugging. It is global so that the daemon and the
361 authentication functions can use it. It does not return any error indication,
362 because major problems such as dropped connections won't show up till an output
363 flush for non-TLS connections. The smtp_fflush() function is available for
364 checking that: for convenience, TLS output errors are remembered here so that
365 they are also picked up later by smtp_fflush().
369 ... optional arguments
375 smtp_printf(char *format, ...)
382 va_start(ap, format);
383 (void) string_vformat(big_buffer, big_buffer_size, format, ap);
385 end = big_buffer + Ustrlen(big_buffer);
386 while ((cr = Ustrchr(big_buffer, '\r')) != NULL) /* lose CRs */
387 memmove(cr, cr + 1, (end--) - cr);
388 debug_printf("SMTP>> %s", big_buffer);
391 va_start(ap, format);
392 if (!string_vformat(big_buffer, big_buffer_size, format, ap))
394 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
395 smtp_closedown(US"Unexpected error");
396 exim_exit(EXIT_FAILURE);
400 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
401 have had the same. Note: this code is also present in smtp_respond(). It would
402 be tidier to have it only in one place, but when it was added, it was easier to
403 do it that way, so as not to have to mess with the code for the RCPT command,
404 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
406 if (rcpt_in_progress)
408 if (rcpt_smtp_response == NULL)
409 rcpt_smtp_response = string_copy(big_buffer);
410 else if (rcpt_smtp_response_same &&
411 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
412 rcpt_smtp_response_same = FALSE;
413 rcpt_in_progress = FALSE;
416 /* Now write the string */
421 if (tls_write(big_buffer, Ustrlen(big_buffer)) < 0) smtp_write_error = -1;
426 if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
431 /*************************************************
432 * Flush SMTP out and check for error *
433 *************************************************/
435 /* This function isn't currently used within Exim (it detects errors when it
436 tries to read the next SMTP input), but is available for use in local_scan().
437 For non-TLS connections, it flushes the output and checks for errors. For
438 TLS-connections, it checks for a previously-detected TLS write error.
441 Returns: 0 for no error; -1 after an error
447 if (tls_active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
448 return smtp_write_error;
453 /*************************************************
454 * SMTP command read timeout *
455 *************************************************/
457 /* Signal handler for timing out incoming SMTP commands. This attempts to
460 Argument: signal number (SIGALRM)
465 command_timeout_handler(int sig)
467 sig = sig; /* Keep picky compilers happy */
468 log_write(L_lost_incoming_connection,
469 LOG_MAIN, "SMTP command timeout on%s connection from %s",
470 (tls_active >= 0)? " TLS" : "",
471 host_and_ident(FALSE));
472 if (smtp_batched_input)
473 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
474 smtp_notquit_exit(US"command-timeout", US"421",
475 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
476 exim_exit(EXIT_FAILURE);
481 /*************************************************
483 *************************************************/
485 /* Signal handler for handling SIGTERM. Again, try to finish tidily.
487 Argument: signal number (SIGTERM)
492 command_sigterm_handler(int sig)
494 sig = sig; /* Keep picky compilers happy */
495 log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
496 if (smtp_batched_input)
497 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
498 smtp_notquit_exit(US"signal-exit", US"421",
499 US"%s: Service not available - closing connection", smtp_active_hostname);
500 exim_exit(EXIT_FAILURE);
506 /*************************************************
507 * Read one command line *
508 *************************************************/
510 /* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
511 There are sites that don't do this, and in any case internal SMTP probably
512 should check only for LF. Consequently, we check here for LF only. The line
513 ends up with [CR]LF removed from its end. If we get an overlong line, treat as
514 an unknown command. The command is read into the global smtp_cmd_buffer so that
515 it is available via $smtp_command.
517 The character reading routine sets up a timeout for each block actually read
518 from the input (which may contain more than one command). We set up a special
519 signal handler that closes down the session on a timeout. Control does not
523 check_sync if TRUE, check synchronization rules if global option is TRUE
525 Returns: a code identifying the command (enumerated above)
529 smtp_read_command(BOOL check_sync)
534 BOOL hadnull = FALSE;
536 os_non_restarting_signal(SIGALRM, command_timeout_handler);
538 while ((c = (receive_getc)()) != '\n' && c != EOF)
540 if (ptr >= smtp_cmd_buffer_size)
542 os_non_restarting_signal(SIGALRM, sigalrm_handler);
550 smtp_cmd_buffer[ptr++] = c;
553 receive_linecount++; /* For BSMTP errors */
554 os_non_restarting_signal(SIGALRM, sigalrm_handler);
556 /* If hit end of file, return pseudo EOF command. Whether we have a
557 part-line already read doesn't matter, since this is an error state. */
559 if (c == EOF) return EOF_CMD;
561 /* Remove any CR and white space at the end of the line, and terminate the
564 while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
565 smtp_cmd_buffer[ptr] = 0;
567 DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
569 /* NULLs are not allowed in SMTP commands */
571 if (hadnull) return BADCHAR_CMD;
573 /* Scan command list and return identity, having set the data pointer
574 to the start of the actual data characters. Check for SMTP synchronization
577 for (p = cmd_list; p < cmd_list_end; p++)
579 if (strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 &&
580 (smtp_cmd_buffer[p->len-1] == ':' || /* "mail from:" or "rcpt to:" */
581 smtp_cmd_buffer[p->len] == 0 ||
582 smtp_cmd_buffer[p->len] == ' '))
584 if (smtp_inptr < smtp_inend && /* Outstanding input */
585 p->cmd < sync_cmd_limit && /* Command should sync */
586 check_sync && /* Local flag set */
587 smtp_enforce_sync && /* Global flag set */
588 sender_host_address != NULL && /* Not local input */
589 !sender_host_notsocket) /* Really is a socket */
592 /* The variables $smtp_command and $smtp_command_argument point into the
593 unmodified input buffer. A copy of the latter is taken for actual
594 processing, so that it can be chopped up into separate parts if necessary,
595 for example, when processing a MAIL command options such as SIZE that can
596 follow the sender address. */
598 smtp_cmd_argument = smtp_cmd_buffer + p->len;
599 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
600 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
601 smtp_cmd_data = smtp_data_buffer;
603 /* Count non-mail commands from those hosts that are controlled in this
604 way. The default is all hosts. We don't waste effort checking the list
605 until we get a non-mail command, but then cache the result to save checking
606 again. If there's a DEFER while checking the host, assume it's in the list.
608 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
609 start of each incoming message by fiddling with the value in the table. */
613 if (count_nonmail == TRUE_UNSET) count_nonmail =
614 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
615 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
616 return TOO_MANY_NONMAIL_CMD;
619 /* If there is data for a command that does not expect it, generate the
622 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
626 /* Enforce synchronization for unknown commands */
628 if (smtp_inptr < smtp_inend && /* Outstanding input */
629 check_sync && /* Local flag set */
630 smtp_enforce_sync && /* Global flag set */
631 sender_host_address != NULL && /* Not local input */
632 !sender_host_notsocket) /* Really is a socket */
640 /*************************************************
641 * Recheck synchronization *
642 *************************************************/
644 /* Synchronization checks can never be perfect because a packet may be on its
645 way but not arrived when the check is done. Such checks can in any case only be
646 done when TLS is not in use. Normally, the checks happen when commands are
647 read: Exim ensures that there is no more input in the input buffer. In normal
648 cases, the response to the command will be fast, and there is no further check.
650 However, for some commands an ACL is run, and that can include delays. In those
651 cases, it is useful to do another check on the input just before sending the
652 response. This also applies at the start of a connection. This function does
653 that check by means of the select() function, as long as the facility is not
654 disabled or inappropriate. A failure of select() is ignored.
656 When there is unwanted input, we read it so that it appears in the log of the
660 Returns: TRUE if all is well; FALSE if there is input pending
668 struct timeval tzero;
670 if (!smtp_enforce_sync || sender_host_address == NULL ||
671 sender_host_notsocket || tls_active >= 0)
674 fd = fileno(smtp_in);
679 rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
681 if (rc <= 0) return TRUE; /* Not ready to read */
683 if (rc < 0) return TRUE; /* End of file or error */
686 rc = smtp_inend - smtp_inptr;
687 if (rc > 150) rc = 150;
694 /*************************************************
695 * Forced closedown of call *
696 *************************************************/
698 /* This function is called from log.c when Exim is dying because of a serious
699 disaster, and also from some other places. If an incoming non-batched SMTP
700 channel is open, it swallows the rest of the incoming message if in the DATA
701 phase, sends the reply string, and gives an error to all subsequent commands
702 except QUIT. The existence of an SMTP call is detected by the non-NULLness of
706 message SMTP reply string to send, excluding the code
712 smtp_closedown(uschar *message)
714 if (smtp_in == NULL || smtp_batched_input) return;
715 receive_swallow_smtp();
716 smtp_printf("421 %s\r\n", message);
720 switch(smtp_read_command(FALSE))
726 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
731 smtp_printf("250 Reset OK\r\n");
735 smtp_printf("421 %s\r\n", message);
744 /*************************************************
745 * Set up connection info for logging *
746 *************************************************/
748 /* This function is called when logging information about an SMTP connection.
749 It sets up appropriate source information, depending on the type of connection.
750 If sender_fullhost is NULL, we are at a very early stage of the connection;
751 just use the IP address.
754 Returns: a string describing the connection
758 smtp_get_connection_info(void)
760 uschar *hostname = (sender_fullhost == NULL)?
761 sender_host_address : sender_fullhost;
764 return string_sprintf("SMTP connection from %s", hostname);
766 if (sender_host_unknown || sender_host_notsocket)
767 return string_sprintf("SMTP connection from %s", sender_ident);
770 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
772 if ((log_extra_selector & LX_incoming_interface) != 0 &&
773 interface_address != NULL)
774 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
775 interface_address, interface_port);
777 return string_sprintf("SMTP connection from %s", hostname);
782 /*************************************************
783 * Log lack of MAIL if so configured *
784 *************************************************/
786 /* This function is called when an SMTP session ends. If the log selector
787 smtp_no_mail is set, write a log line giving some details of what has happened
795 smtp_log_no_mail(void)
800 if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0)
806 if (sender_host_authenticated != NULL)
808 s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated);
809 if (authenticated_id != NULL)
810 s = string_append(s, &size, &ptr, 2, US":", authenticated_id);
814 if ((log_extra_selector & LX_tls_cipher) != 0 && tls_cipher != NULL)
815 s = string_append(s, &size, &ptr, 2, US" X=", tls_cipher);
816 if ((log_extra_selector & LX_tls_certificate_verified) != 0 &&
818 s = string_append(s, &size, &ptr, 2, US" CV=",
819 tls_certificate_verified? "yes":"no");
820 if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_peerdn != NULL)
821 s = string_append(s, &size, &ptr, 3, US" DN=\"", tls_peerdn, US"\"");
824 sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)?
825 US" C=..." : US" C=";
826 for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
828 if (smtp_connection_had[i] != SCH_NONE)
830 s = string_append(s, &size, &ptr, 2, sep,
831 smtp_names[smtp_connection_had[i]]);
836 for (i = 0; i < smtp_ch_index; i++)
838 s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]);
842 if (s != NULL) s[ptr] = 0; else s = US"";
843 log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s",
844 host_and_ident(FALSE),
845 readconf_printtime(time(NULL) - smtp_connection_start), s);
850 /*************************************************
851 * Check HELO line and set sender_helo_name *
852 *************************************************/
854 /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
855 the domain name of the sending host, or an ip literal in square brackets. The
856 arrgument is placed in sender_helo_name, which is in malloc store, because it
857 must persist over multiple incoming messages. If helo_accept_junk is set, this
858 host is permitted to send any old junk (needed for some broken hosts).
859 Otherwise, helo_allow_chars can be used for rogue characters in general
860 (typically people want to let in underscores).
863 s the data portion of the line (already past any white space)
865 Returns: TRUE or FALSE
869 check_helo(uschar *s)
872 uschar *end = s + Ustrlen(s);
873 BOOL yield = helo_accept_junk;
875 /* Discard any previous helo name */
877 if (sender_helo_name != NULL)
879 store_free(sender_helo_name);
880 sender_helo_name = NULL;
883 /* Skip tests if junk is permitted. */
887 /* Allow the new standard form for IPv6 address literals, namely,
888 [IPv6:....], and because someone is bound to use it, allow an equivalent
889 IPv4 form. Allow plain addresses as well. */
896 if (strncmpic(s, US"[IPv6:", 6) == 0)
897 yield = (string_is_ip_address(s+6, NULL) == 6);
898 else if (strncmpic(s, US"[IPv4:", 6) == 0)
899 yield = (string_is_ip_address(s+6, NULL) == 4);
901 yield = (string_is_ip_address(s+1, NULL) != 0);
906 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
907 that have been configured (usually underscore - sigh). */
914 if (!isalnum(*s) && *s != '.' && *s != '-' &&
915 Ustrchr(helo_allow_chars, *s) == NULL)
925 /* Save argument if OK */
927 if (yield) sender_helo_name = string_copy_malloc(start);
935 /*************************************************
936 * Extract SMTP command option *
937 *************************************************/
939 /* This function picks the next option setting off the end of smtp_cmd_data. It
940 is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
941 things that can appear there.
944 name point this at the name
945 value point this at the data string
947 Returns: TRUE if found an option
951 extract_option(uschar **name, uschar **value)
954 uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
955 while (isspace(*v)) v--;
958 while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--;
959 if (*v != '=') return FALSE;
962 while(isalpha(n[-1])) n--;
964 if (n[-1] != ' ') return FALSE;
977 /*************************************************
978 * Reset for new message *
979 *************************************************/
981 /* This function is called whenever the SMTP session is reset from
982 within either of the setup functions.
984 Argument: the stacking pool storage reset point
989 smtp_reset(void *reset_point)
991 store_reset(reset_point);
992 recipients_list = NULL;
993 rcpt_count = rcpt_defer_count = rcpt_fail_count =
994 raw_recipients_count = recipients_count = recipients_list_max = 0;
995 message_linecount = 0;
997 acl_added_headers = NULL;
998 queue_only_policy = FALSE;
999 rcpt_smtp_response = NULL;
1000 rcpt_smtp_response_same = TRUE;
1001 rcpt_in_progress = FALSE;
1002 deliver_freeze = FALSE; /* Can be set by ACL */
1003 freeze_tell = freeze_tell_config; /* Can be set by ACL */
1004 fake_response = OK; /* Can be set by ACL */
1005 #ifdef WITH_CONTENT_SCAN
1006 no_mbox_unspool = FALSE; /* Can be set by ACL */
1008 submission_mode = FALSE; /* Can be set by ACL */
1009 suppress_local_fixups = FALSE; /* Can be set by ACL */
1010 active_local_from_check = local_from_check; /* Can be set by ACL */
1011 active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
1012 sender_address = NULL;
1013 submission_name = NULL; /* Can be set by ACL */
1014 raw_sender = NULL; /* After SMTP rewrite, before qualifying */
1015 sender_address_unrewritten = NULL; /* Set only after verify rewrite */
1016 sender_verified_list = NULL; /* No senders verified */
1017 memset(sender_address_cache, 0, sizeof(sender_address_cache));
1018 memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
1019 authenticated_sender = NULL;
1020 #ifdef EXPERIMENTAL_BRIGHTMAIL
1022 bmi_verdicts = NULL;
1024 #ifdef EXPERIMENTAL_DOMAINKEYS
1027 #ifdef EXPERIMENTAL_SPF
1028 spf_header_comment = NULL;
1029 spf_received = NULL;
1031 spf_smtp_comment = NULL;
1033 body_linecount = body_zerocount = 0;
1035 sender_rate = sender_rate_limit = sender_rate_period = NULL;
1036 ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
1037 /* Note that ratelimiters_conn persists across resets. */
1039 /* Reset message ACL variables */
1043 /* The message body variables use malloc store. They may be set if this is
1044 not the first message in an SMTP session and the previous message caused them
1045 to be referenced in an ACL. */
1047 if (message_body != NULL)
1049 store_free(message_body);
1050 message_body = NULL;
1053 if (message_body_end != NULL)
1055 store_free(message_body_end);
1056 message_body_end = NULL;
1059 /* Warning log messages are also saved in malloc store. They are saved to avoid
1060 repetition in the same message, but it seems right to repeat them for different
1063 while (acl_warn_logged != NULL)
1065 string_item *this = acl_warn_logged;
1066 acl_warn_logged = acl_warn_logged->next;
1075 /*************************************************
1076 * Initialize for incoming batched SMTP message *
1077 *************************************************/
1079 /* This function is called from smtp_setup_msg() in the case when
1080 smtp_batched_input is true. This happens when -bS is used to pass a whole batch
1081 of messages in one file with SMTP commands between them. All errors must be
1082 reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
1083 relevant. After an error on a sender, or an invalid recipient, the remainder
1084 of the message is skipped. The value of received_protocol is already set.
1087 Returns: > 0 message successfully started (reached DATA)
1088 = 0 QUIT read or end of file reached
1089 < 0 should not occur
1093 smtp_setup_batch_msg(void)
1096 void *reset_point = store_get(0);
1098 /* Save the line count at the start of each transaction - single commands
1099 like HELO and RSET count as whole transactions. */
1101 bsmtp_transaction_linecount = receive_linecount;
1103 if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
1105 smtp_reset(reset_point); /* Reset for start of message */
1107 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
1108 value. The values are 2 larger than the required yield of the function. */
1113 uschar *recipient = NULL;
1114 int start, end, sender_domain, recipient_domain;
1116 switch(smtp_read_command(FALSE))
1118 /* The HELO/EHLO commands set sender_address_helo if they have
1119 valid data; otherwise they are ignored, except that they do
1120 a reset of the state. */
1125 check_helo(smtp_cmd_data);
1129 smtp_reset(reset_point);
1130 bsmtp_transaction_linecount = receive_linecount;
1134 /* The MAIL FROM command requires an address as an operand. All we
1135 do here is to parse it for syntactic correctness. The form "<>" is
1136 a special case which converts into an empty string. The start/end
1137 pointers in the original are not used further for this address, as
1138 it is the canonical extracted address which is all that is kept. */
1141 if (sender_address != NULL)
1142 /* The function moan_smtp_batch() does not return. */
1143 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
1145 if (smtp_cmd_data[0] == 0)
1146 /* The function moan_smtp_batch() does not return. */
1147 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
1149 /* Reset to start of message */
1151 smtp_reset(reset_point);
1153 /* Apply SMTP rewrite */
1155 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
1156 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
1157 US"", global_rewrite_rules) : smtp_cmd_data;
1159 /* Extract the address; the TRUE flag allows <> as valid */
1162 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
1165 if (raw_sender == NULL)
1166 /* The function moan_smtp_batch() does not return. */
1167 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
1169 sender_address = string_copy(raw_sender);
1171 /* Qualify unqualified sender addresses if permitted to do so. */
1173 if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@')
1175 if (allow_unqualified_sender)
1177 sender_address = rewrite_address_qualify(sender_address, FALSE);
1178 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
1179 "and rewritten\n", raw_sender);
1181 /* The function moan_smtp_batch() does not return. */
1182 else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
1188 /* The RCPT TO command requires an address as an operand. All we do
1189 here is to parse it for syntactic correctness. There may be any number
1190 of RCPT TO commands, specifying multiple senders. We build them all into
1191 a data structure that is in argc/argv format. The start/end values
1192 given by parse_extract_address are not used, as we keep only the
1193 extracted address. */
1196 if (sender_address == NULL)
1197 /* The function moan_smtp_batch() does not return. */
1198 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
1200 if (smtp_cmd_data[0] == 0)
1201 /* The function moan_smtp_batch() does not return. */
1202 moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
1204 /* Check maximum number allowed */
1206 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
1207 /* The function moan_smtp_batch() does not return. */
1208 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
1209 recipients_max_reject? "552": "452");
1211 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
1212 recipient address */
1214 recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
1215 rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
1216 global_rewrite_rules) : smtp_cmd_data;
1218 /* rfc821_domains = TRUE; << no longer needed */
1219 recipient = parse_extract_address(recipient, &errmess, &start, &end,
1220 &recipient_domain, FALSE);
1221 /* rfc821_domains = FALSE; << no longer needed */
1223 if (recipient == NULL)
1224 /* The function moan_smtp_batch() does not return. */
1225 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
1227 /* If the recipient address is unqualified, qualify it if permitted. Then
1228 add it to the list of recipients. */
1230 if (recipient_domain == 0)
1232 if (allow_unqualified_recipient)
1234 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
1236 recipient = rewrite_address_qualify(recipient, TRUE);
1238 /* The function moan_smtp_batch() does not return. */
1239 else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain "
1242 receive_add_recipient(recipient, -1);
1246 /* The DATA command is legal only if it follows successful MAIL FROM
1247 and RCPT TO commands. This function is complete when a valid DATA
1248 command is encountered. */
1251 if (sender_address == NULL || recipients_count <= 0)
1253 /* The function moan_smtp_batch() does not return. */
1254 if (sender_address == NULL)
1255 moan_smtp_batch(smtp_cmd_buffer,
1256 "503 MAIL FROM:<sender> command must precede DATA");
1258 moan_smtp_batch(smtp_cmd_buffer,
1259 "503 RCPT TO:<recipient> must precede DATA");
1263 done = 3; /* DATA successfully achieved */
1264 message_ended = END_NOTENDED; /* Indicate in middle of message */
1269 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
1276 bsmtp_transaction_linecount = receive_linecount;
1287 /* The function moan_smtp_batch() does not return. */
1288 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
1293 /* The function moan_smtp_batch() does not return. */
1294 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
1299 /* The function moan_smtp_batch() does not return. */
1300 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
1305 return done - 2; /* Convert yield values */
1311 /*************************************************
1312 * Start an SMTP session *
1313 *************************************************/
1315 /* This function is called at the start of an SMTP session. Thereafter,
1316 smtp_setup_msg() is called to initiate each separate message. This
1317 function does host-specific testing, and outputs the banner line.
1320 Returns: FALSE if the session can not continue; something has
1321 gone wrong, or the connection to the host is blocked
1325 smtp_start_session(void)
1329 uschar *user_msg, *log_msg;
1333 smtp_connection_start = time(NULL);
1334 for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
1335 smtp_connection_had[smtp_ch_index] = SCH_NONE;
1338 /* Default values for certain variables */
1340 helo_seen = esmtp = helo_accept_junk = FALSE;
1341 smtp_mailcmd_count = 0;
1342 count_nonmail = TRUE_UNSET;
1343 synprot_error_count = unknown_command_count = nonmail_command_count = 0;
1344 smtp_delay_mail = smtp_rlm_base;
1345 auth_advertised = FALSE;
1346 pipelining_advertised = FALSE;
1347 pipelining_enable = TRUE;
1348 sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
1349 smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
1351 memset(sender_host_cache, 0, sizeof(sender_host_cache));
1353 /* If receiving by -bs from a trusted user, or testing with -bh, we allow
1354 authentication settings from -oMaa to remain in force. */
1356 if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL;
1357 authenticated_by = NULL;
1360 tls_cipher = tls_peerdn = NULL;
1361 tls_advertised = FALSE;
1364 /* Reset ACL connection variables */
1368 /* Allow for trailing 0 in the command and data buffers. */
1370 smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2);
1371 if (smtp_cmd_buffer == NULL)
1372 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1373 "malloc() failed for SMTP command buffer");
1374 smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1;
1376 /* For batched input, the protocol setting can be overridden from the
1377 command line by a trusted caller. */
1379 if (smtp_batched_input)
1381 if (received_protocol == NULL) received_protocol = US"local-bsmtp";
1384 /* For non-batched SMTP input, the protocol setting is forced here. It will be
1385 reset later if any of EHLO/AUTH/STARTTLS are received. */
1389 protocols[pnormal] + ((sender_host_address != NULL)? pnlocal : 0);
1391 /* Set up the buffer for inputting using direct read() calls, and arrange to
1392 call the local functions instead of the standard C ones. */
1394 smtp_inbuffer = (uschar *)malloc(in_buffer_size);
1395 if (smtp_inbuffer == NULL)
1396 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
1397 receive_getc = smtp_getc;
1398 receive_ungetc = smtp_ungetc;
1399 receive_feof = smtp_feof;
1400 receive_ferror = smtp_ferror;
1401 receive_smtp_buffered = smtp_buffered;
1402 smtp_inptr = smtp_inend = smtp_inbuffer;
1403 smtp_had_eof = smtp_had_error = 0;
1405 /* Set up the message size limit; this may be host-specific */
1407 thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
1408 if (expand_string_message != NULL)
1410 if (thismessage_size_limit == -1)
1411 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
1412 "%s", expand_string_message);
1414 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
1415 "%s", expand_string_message);
1416 smtp_closedown(US"Temporary local problem - please try later");
1420 /* When a message is input locally via the -bs or -bS options, sender_host_
1421 unknown is set unless -oMa was used to force an IP address, in which case it
1422 is checked like a real remote connection. When -bs is used from inetd, this
1423 flag is not set, causing the sending host to be checked. The code that deals
1424 with IP source routing (if configured) is never required for -bs or -bS and
1425 the flag sender_host_notsocket is used to suppress it.
1427 If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
1428 reserve for certain hosts and/or networks. */
1430 if (!sender_host_unknown)
1433 BOOL reserved_host = FALSE;
1435 /* Look up IP options (source routing info) on the socket if this is not an
1436 -oMa "host", and if any are found, log them and drop the connection.
1438 Linux (and others now, see below) is different to everyone else, so there
1439 has to be some conditional compilation here. Versions of Linux before 2.1.15
1440 used a structure whose name was "options". Somebody finally realized that
1441 this name was silly, and it got changed to "ip_options". I use the
1442 newer name here, but there is a fudge in the script that sets up os.h
1443 to define a macro in older Linux systems.
1445 Sigh. Linux is a fast-moving target. Another generation of Linux uses
1446 glibc 2, which has chosen ip_opts for the structure name. This is now
1447 really a glibc thing rather than a Linux thing, so the condition name
1448 has been changed to reflect this. It is relevant also to GNU/Hurd.
1450 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
1451 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
1452 a special macro defined in the os.h file.
1454 Some DGUX versions on older hardware appear not to support IP options at
1455 all, so there is now a general macro which can be set to cut out this
1458 How to do this properly in IPv6 is not yet known. */
1460 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
1462 #ifdef GLIBC_IP_OPTIONS
1463 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
1468 #elif defined DARWIN_IP_OPTIONS
1474 if (!host_checking && !sender_host_notsocket)
1477 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
1478 struct ip_options *ipopt = store_get(optlen);
1480 struct ip_opts ipoptblock;
1481 struct ip_opts *ipopt = &ipoptblock;
1482 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
1484 struct ipoption ipoptblock;
1485 struct ipoption *ipopt = &ipoptblock;
1486 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
1489 /* Occasional genuine failures of getsockopt() have been seen - for
1490 example, "reset by peer". Therefore, just log and give up on this
1491 call, unless the error is ENOPROTOOPT. This error is given by systems
1492 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
1493 of writing. So for that error, carry on - we just can't do an IP options
1496 DEBUG(D_receive) debug_printf("checking for IP options\n");
1498 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt),
1501 if (errno != ENOPROTOOPT)
1503 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
1504 host_and_ident(FALSE), strerror(errno));
1505 smtp_printf("451 SMTP service not available\r\n");
1510 /* Deal with any IP options that are set. On the systems I have looked at,
1511 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
1512 more logging data than will fit in big_buffer. Nevertheless, after somebody
1513 questioned this code, I've added in some paranoid checking. */
1515 else if (optlen > 0)
1517 uschar *p = big_buffer;
1518 uschar *pend = big_buffer + big_buffer_size;
1519 uschar *opt, *adptr;
1521 struct in_addr addr;
1524 uschar *optstart = (uschar *)(ipopt->__data);
1526 uschar *optstart = (uschar *)(ipopt->ip_opts);
1528 uschar *optstart = (uschar *)(ipopt->ipopt_list);
1531 DEBUG(D_receive) debug_printf("IP options exist\n");
1533 Ustrcpy(p, "IP options on incoming call:");
1536 for (opt = optstart; opt != NULL &&
1537 opt < (uschar *)(ipopt) + optlen;)
1551 if (!string_format(p, pend-p, " %s [@%s",
1552 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
1554 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
1556 inet_ntoa(ipopt->ip_dst)))
1558 inet_ntoa(ipopt->ipopt_dst)))
1566 optcount = (opt[1] - 3) / sizeof(struct in_addr);
1568 while (optcount-- > 0)
1570 memcpy(&addr, adptr, sizeof(addr));
1571 if (!string_format(p, pend - p - 1, "%s%s",
1572 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
1578 adptr += sizeof(struct in_addr);
1587 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
1590 for (i = 0; i < opt[1]; i++)
1592 sprintf(CS p, "%2.2x ", opt[i]);
1603 log_write(0, LOG_MAIN, "%s", big_buffer);
1605 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
1607 log_write(0, LOG_MAIN|LOG_REJECT,
1608 "connection from %s refused (IP options)", host_and_ident(FALSE));
1610 smtp_printf("554 SMTP service not available\r\n");
1614 /* Length of options = 0 => there are no options */
1616 else DEBUG(D_receive) debug_printf("no IP options found\n");
1618 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
1620 /* Set keep-alive in socket options. The option is on by default. This
1621 setting is an attempt to get rid of some hanging connections that stick in
1622 read() when the remote end (usually a dialup) goes away. */
1624 if (smtp_accept_keepalive && !sender_host_notsocket)
1625 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
1627 /* If the current host matches host_lookup, set the name by doing a
1628 reverse lookup. On failure, sender_host_name will be NULL and
1629 host_lookup_failed will be TRUE. This may or may not be serious - optional
1632 if (verify_check_host(&host_lookup) == OK)
1634 (void)host_name_lookup();
1635 host_build_sender_fullhost();
1638 /* Delay this until we have the full name, if it is looked up. */
1640 set_process_info("handling incoming connection from %s",
1641 host_and_ident(FALSE));
1643 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
1644 smtps port for use with older style SSL MTAs. */
1647 if (tls_on_connect &&
1648 tls_server_start(tls_require_ciphers,
1649 gnutls_require_mac, gnutls_require_kx, gnutls_require_proto) != OK)
1653 /* Test for explicit connection rejection */
1655 if (verify_check_host(&host_reject_connection) == OK)
1657 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
1658 "from %s (host_reject_connection)", host_and_ident(FALSE));
1659 smtp_printf("554 SMTP service not available\r\n");
1663 /* Test with TCP Wrappers if so configured. There is a problem in that
1664 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
1665 such as disks dying. In these cases, it is desirable to reject with a 4xx
1666 error instead of a 5xx error. There isn't a "right" way to detect such
1667 problems. The following kludge is used: errno is zeroed before calling
1668 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
1669 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
1672 #ifdef USE_TCP_WRAPPERS
1674 if (!hosts_ctl("exim",
1675 (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name,
1676 (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address,
1677 (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident))
1679 if (errno == 0 || errno == ENOENT)
1681 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
1682 log_write(L_connection_reject,
1683 LOG_MAIN|LOG_REJECT, "refused connection from %s "
1684 "(tcp wrappers)", host_and_ident(FALSE));
1685 smtp_printf("554 SMTP service not available\r\n");
1689 int save_errno = errno;
1690 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
1691 "errno value %d\n", save_errno);
1692 log_write(L_connection_reject,
1693 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
1694 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
1695 smtp_printf("451 Temporary local problem - please try later\r\n");
1701 /* Check for reserved slots. The value of smtp_accept_count has already been
1702 incremented to include this process. */
1704 if (smtp_accept_max > 0 &&
1705 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
1707 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
1709 log_write(L_connection_reject,
1710 LOG_MAIN, "temporarily refused connection from %s: not in "
1711 "reserve list: connected=%d max=%d reserve=%d%s",
1712 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
1713 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
1714 smtp_printf("421 %s: Too many concurrent SMTP connections; "
1715 "please try again later\r\n", smtp_active_hostname);
1718 reserved_host = TRUE;
1721 /* If a load level above which only messages from reserved hosts are
1722 accepted is set, check the load. For incoming calls via the daemon, the
1723 check is done in the superior process if there are no reserved hosts, to
1724 save a fork. In all cases, the load average will already be available
1725 in a global variable at this point. */
1727 if (smtp_load_reserve >= 0 &&
1728 load_average > smtp_load_reserve &&
1730 verify_check_host(&smtp_reserve_hosts) != OK)
1732 log_write(L_connection_reject,
1733 LOG_MAIN, "temporarily refused connection from %s: not in "
1734 "reserve list and load average = %.2f", host_and_ident(FALSE),
1735 (double)load_average/1000.0);
1736 smtp_printf("421 %s: Too much load; please try again later\r\n",
1737 smtp_active_hostname);
1741 /* Determine whether unqualified senders or recipients are permitted
1742 for this host. Unfortunately, we have to do this every time, in order to
1743 set the flags so that they can be inspected when considering qualifying
1744 addresses in the headers. For a site that permits no qualification, this
1745 won't take long, however. */
1747 allow_unqualified_sender =
1748 verify_check_host(&sender_unqualified_hosts) == OK;
1750 allow_unqualified_recipient =
1751 verify_check_host(&recipient_unqualified_hosts) == OK;
1753 /* Determine whether HELO/EHLO is required for this host. The requirement
1754 can be hard or soft. */
1756 helo_required = verify_check_host(&helo_verify_hosts) == OK;
1758 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
1760 /* Determine whether this hosts is permitted to send syntactic junk
1761 after a HELO or EHLO command. */
1763 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
1766 /* For batch SMTP input we are now done. */
1768 if (smtp_batched_input) return TRUE;
1770 /* Run the ACL if it exists */
1773 if (acl_smtp_connect != NULL)
1776 rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
1780 (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
1785 /* Output the initial message for a two-way SMTP connection. It may contain
1786 newlines, which then cause a multi-line response to be given. */
1788 code = US"220"; /* Default status code */
1789 esc = US""; /* Default extended status code */
1790 esclen = 0; /* Length of esc */
1792 if (user_msg == NULL)
1794 s = expand_string(smtp_banner);
1796 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
1797 "failed: %s", smtp_banner, expand_string_message);
1803 smtp_message_code(&code, &codelen, &s, NULL);
1807 esclen = codelen - 4;
1811 /* Remove any terminating newlines; might as well remove trailing space too */
1814 while (p > s && isspace(p[-1])) p--;
1817 /* It seems that CC:Mail is braindead, and assumes that the greeting message
1818 is all contained in a single IP packet. The original code wrote out the
1819 greeting using several calls to fprint/fputc, and on busy servers this could
1820 cause it to be split over more than one packet - which caused CC:Mail to fall
1821 over when it got the second part of the greeting after sending its first
1822 command. Sigh. To try to avoid this, build the complete greeting message
1823 first, and output it in one fell swoop. This gives a better chance of it
1824 ending up as a single packet. */
1826 ss = store_get(size);
1830 do /* At least once, in case we have an empty string */
1833 uschar *linebreak = Ustrchr(p, '\n');
1834 ss = string_cat(ss, &size, &ptr, code, 3);
1835 if (linebreak == NULL)
1838 ss = string_cat(ss, &size, &ptr, US" ", 1);
1842 len = linebreak - p;
1843 ss = string_cat(ss, &size, &ptr, US"-", 1);
1845 ss = string_cat(ss, &size, &ptr, esc, esclen);
1846 ss = string_cat(ss, &size, &ptr, p, len);
1847 ss = string_cat(ss, &size, &ptr, US"\r\n", 2);
1849 if (linebreak != NULL) p++;
1853 ss[ptr] = 0; /* string_cat leaves room for this */
1855 /* Before we write the banner, check that there is no input pending, unless
1856 this synchronisation check is disabled. */
1860 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
1861 "synchronization error (input sent without waiting for greeting): "
1862 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
1863 string_printing(smtp_inptr));
1864 smtp_printf("554 SMTP synchronization error\r\n");
1868 /* Now output the banner */
1870 smtp_printf("%s", ss);
1878 /*************************************************
1879 * Handle SMTP syntax and protocol errors *
1880 *************************************************/
1882 /* Write to the log for SMTP syntax errors in incoming commands, if configured
1883 to do so. Then transmit the error response. The return value depends on the
1884 number of syntax and protocol errors in this SMTP session.
1887 type error type, given as a log flag bit
1888 code response code; <= 0 means don't send a response
1889 data data to reflect in the response (can be NULL)
1890 errmess the error message
1892 Returns: -1 limit of syntax/protocol errors NOT exceeded
1893 +1 limit of syntax/protocol errors IS exceeded
1895 These values fit in with the values of the "done" variable in the main
1896 processing loop in smtp_setup_msg(). */
1899 synprot_error(int type, int code, uschar *data, uschar *errmess)
1903 log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
1904 (type == L_smtp_syntax_error)? "syntax" : "protocol",
1905 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
1907 if (++synprot_error_count > smtp_max_synprot_errors)
1910 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
1911 "syntax or protocol errors (last command was \"%s\")",
1912 host_and_ident(FALSE), smtp_cmd_buffer);
1917 smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ',
1918 (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess);
1920 smtp_printf("%d Too many syntax or protocol errors\r\n", code);
1929 /*************************************************
1930 * Log incomplete transactions *
1931 *************************************************/
1933 /* This function is called after a transaction has been aborted by RSET, QUIT,
1934 connection drops or other errors. It logs the envelope information received
1935 so far in order to preserve address verification attempts.
1937 Argument: string to indicate what aborted the transaction
1942 incomplete_transaction_log(uschar *what)
1944 if (sender_address == NULL || /* No transaction in progress */
1945 (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */
1948 /* Build list of recipients for logging */
1950 if (recipients_count > 0)
1953 raw_recipients = store_get(recipients_count * sizeof(uschar *));
1954 for (i = 0; i < recipients_count; i++)
1955 raw_recipients[i] = recipients_list[i].address;
1956 raw_recipients_count = recipients_count;
1959 log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
1960 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
1966 /*************************************************
1967 * Send SMTP response, possibly multiline *
1968 *************************************************/
1970 /* There are, it seems, broken clients out there that cannot handle multiline
1971 responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
1972 output nothing for non-final calls, and only the first line for anything else.
1975 code SMTP code, may involve extended status codes
1976 codelen length of smtp code; if > 4 there's an ESC
1977 final FALSE if the last line isn't the final line
1978 msg message text, possibly containing newlines
1984 smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
1989 if (!final && no_multiline_responses) return;
1994 esclen = codelen - 4;
1997 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
1998 have had the same. Note: this code is also present in smtp_printf(). It would
1999 be tidier to have it only in one place, but when it was added, it was easier to
2000 do it that way, so as not to have to mess with the code for the RCPT command,
2001 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
2003 if (rcpt_in_progress)
2005 if (rcpt_smtp_response == NULL)
2006 rcpt_smtp_response = string_copy(msg);
2007 else if (rcpt_smtp_response_same &&
2008 Ustrcmp(rcpt_smtp_response, msg) != 0)
2009 rcpt_smtp_response_same = FALSE;
2010 rcpt_in_progress = FALSE;
2013 /* Not output the message, splitting it up into multiple lines if necessary. */
2017 uschar *nl = Ustrchr(msg, '\n');
2020 smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg);
2023 else if (nl[1] == 0 || no_multiline_responses)
2025 smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc,
2026 (int)(nl - msg), msg);
2031 smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg);
2033 while (isspace(*msg)) msg++;
2041 /*************************************************
2042 * Parse user SMTP message *
2043 *************************************************/
2045 /* This function allows for user messages overriding the response code details
2046 by providing a suitable response code string at the start of the message
2047 user_msg. Check the message for starting with a response code and optionally an
2048 extended status code. If found, check that the first digit is valid, and if so,
2049 change the code pointer and length to use the replacement. An invalid code
2050 causes a panic log; in this case, if the log messages is the same as the user
2051 message, we must also adjust the value of the log message to show the code that
2052 is actually going to be used (the original one).
2054 This function is global because it is called from receive.c as well as within
2057 Note that the code length returned includes the terminating whitespace
2058 character, which is always included in the regex match.
2061 code SMTP code, may involve extended status codes
2062 codelen length of smtp code; if > 4 there's an ESC
2064 log_msg optional log message, to be adjusted with the new SMTP code
2070 smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg)
2075 if (msg == NULL || *msg == NULL) return;
2077 n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
2078 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int));
2081 if ((*msg)[0] != (*code)[0])
2083 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
2084 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
2085 if (log_msg != NULL && *log_msg == *msg)
2086 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
2091 *codelen = ovector[1]; /* Includes final space */
2093 *msg += ovector[1]; /* Chop the code off the message */
2100 /*************************************************
2101 * Handle an ACL failure *
2102 *************************************************/
2104 /* This function is called when acl_check() fails. As well as calls from within
2105 this module, it is called from receive.c for an ACL after DATA. It sorts out
2106 logging the incident, and sets up the error response. A message containing
2107 newlines is turned into a multiline SMTP response, but for logging, only the
2110 There's a table of default permanent failure response codes to use in
2111 globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
2112 defaults disabled in Exim. However, discussion in connection with RFC 821bis
2113 (aka RFC 2821) has concluded that the response should be 252 in the disabled
2114 state, because there are broken clients that try VRFY before RCPT. A 5xx
2115 response should be given only when the address is positively known to be
2116 undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH,
2119 From Exim 4.63, it is possible to override the response code details by
2120 providing a suitable response code string at the start of the message provided
2121 in user_msg. The code's first digit is checked for validity.
2124 where where the ACL was called from
2126 user_msg a message that can be included in an SMTP response
2127 log_msg a message for logging
2129 Returns: 0 in most cases
2130 2 if the failure code was FAIL_DROP, in which case the
2131 SMTP connection should be dropped (this value fits with the
2132 "done" variable in smtp_setup_msg() below)
2136 smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
2138 BOOL drop = rc == FAIL_DROP;
2142 uschar *sender_info = US"";
2144 #ifdef WITH_CONTENT_SCAN
2145 (where == ACL_WHERE_MIME)? US"during MIME ACL checks" :
2147 (where == ACL_WHERE_PREDATA)? US"DATA" :
2148 (where == ACL_WHERE_DATA)? US"after DATA" :
2149 (smtp_cmd_data == NULL)?
2150 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) :
2151 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data);
2153 if (drop) rc = FAIL;
2155 /* Set the default SMTP code, and allow a user message to change it. */
2157 smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where];
2158 smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg);
2160 /* We used to have sender_address here; however, there was a bug that was not
2161 updating sender_address after a rewrite during a verify. When this bug was
2162 fixed, sender_address at this point became the rewritten address. I'm not sure
2163 this is what should be logged, so I've changed to logging the unrewritten
2164 address to retain backward compatibility. */
2166 #ifndef WITH_CONTENT_SCAN
2167 if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
2169 if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
2172 sender_info = string_sprintf("F=<%s> ", (sender_address_unrewritten != NULL)?
2173 sender_address_unrewritten : sender_address);
2176 /* If there's been a sender verification failure with a specific message, and
2177 we have not sent a response about it yet, do so now, as a preliminary line for
2178 failures, but not defers. However, always log it for defer, and log it for fail
2179 unless the sender_verify_fail log selector has been turned off. */
2181 if (sender_verified_failed != NULL &&
2182 !testflag(sender_verified_failed, af_sverify_told))
2184 BOOL save_rcpt_in_progress = rcpt_in_progress;
2185 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
2187 setflag(sender_verified_failed, af_sverify_told);
2189 if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0)
2190 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
2191 host_and_ident(TRUE),
2192 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
2193 sender_verified_failed->address,
2194 (sender_verified_failed->message == NULL)? US"" :
2195 string_sprintf(": %s", sender_verified_failed->message));
2197 if (rc == FAIL && sender_verified_failed->user_message != NULL)
2198 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
2199 testflag(sender_verified_failed, af_verify_pmfail)?
2200 "Postmaster verification failed while checking <%s>\n%s\n"
2201 "Several RFCs state that you are required to have a postmaster\n"
2202 "mailbox for each mail domain. This host does not accept mail\n"
2203 "from domains whose servers reject the postmaster address."
2205 testflag(sender_verified_failed, af_verify_nsfail)?
2206 "Callback setup failed while verifying <%s>\n%s\n"
2207 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
2208 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
2209 "RFC requirements, and stops you from receiving standard bounce\n"
2210 "messages. This host does not accept mail from domains whose servers\n"
2213 "Verification failed for <%s>\n%s",
2214 sender_verified_failed->address,
2215 sender_verified_failed->user_message));
2217 rcpt_in_progress = save_rcpt_in_progress;
2220 /* Sort out text for logging */
2222 log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg);
2223 lognl = Ustrchr(log_msg, '\n');
2224 if (lognl != NULL) *lognl = 0;
2226 /* Send permanent failure response to the command, but the code used isn't
2227 always a 5xx one - see comments at the start of this function. If the original
2228 rc was FAIL_DROP we drop the connection and yield 2. */
2230 if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)?
2231 US"Administrative prohibition" : user_msg);
2233 /* Send temporary failure response to the command. Don't give any details,
2234 unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
2235 verb, and for a header verify when smtp_return_error_details is set.
2237 This conditional logic is all somewhat of a mess because of the odd
2238 interactions between temp_details and return_error_details. One day it should
2239 be re-implemented in a tidier fashion. */
2243 if (acl_temp_details && user_msg != NULL)
2245 if (smtp_return_error_details &&
2246 sender_verified_failed != NULL &&
2247 sender_verified_failed->message != NULL)
2249 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
2251 smtp_respond(smtp_code, codelen, TRUE, user_msg);
2254 smtp_respond(smtp_code, codelen, TRUE,
2255 US"Temporary local problem - please try later");
2258 /* Log the incident to the logs that are specified by log_reject_target
2259 (default main, reject). This can be empty to suppress logging of rejections. If
2260 the connection is not forcibly to be dropped, return 0. Otherwise, log why it
2261 is closing if required and return 2. */
2263 if (log_reject_target != 0)
2264 log_write(0, log_reject_target, "%s %s%srejected %s%s",
2265 host_and_ident(TRUE),
2266 sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg);
2268 if (!drop) return 0;
2270 log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
2271 smtp_get_connection_info());
2273 /* Run the not-quit ACL, but without any custom messages. This should not be a
2274 problem, because we get here only if some other ACL has issued "drop", and
2275 in that case, *its* custom messages will have been used above. */
2277 smtp_notquit_exit(US"acl-drop", NULL, NULL);
2284 /*************************************************
2285 * Handle SMTP exit when QUIT is not given *
2286 *************************************************/
2288 /* This function provides a logging/statistics hook for when an SMTP connection
2289 is dropped on the floor or the other end goes away. It's a global function
2290 because it's called from receive.c as well as this module. As well as running
2291 the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
2292 response, either with a custom message from the ACL, or using a default. There
2293 is one case, however, when no message is output - after "drop". In that case,
2294 the ACL that obeyed "drop" has already supplied the custom message, and NULL is
2295 passed to this function.
2297 In case things go wrong while processing this function, causing an error that
2298 may re-enter this funtion, there is a recursion check.
2301 reason What $smtp_notquit_reason will be set to in the ACL;
2302 if NULL, the ACL is not run
2303 code The error code to return as part of the response
2304 defaultrespond The default message if there's no user_msg
2310 smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
2313 uschar *user_msg = NULL;
2314 uschar *log_msg = NULL;
2316 /* Check for recursive acll */
2318 if (smtp_exit_function_called)
2320 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
2324 smtp_exit_function_called = TRUE;
2326 /* Call the not-QUIT ACL, if there is one, unless no reason is given. */
2328 if (acl_smtp_notquit != NULL && reason != NULL)
2330 smtp_notquit_reason = reason;
2331 rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
2334 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
2338 /* Write an SMTP response if we are expected to give one. As the default
2339 responses are all internal, they should always fit in the buffer, but code a
2340 warning, just in case. Note that string_vformat() still leaves a complete
2341 string, even if it is incomplete. */
2343 if (code != NULL && defaultrespond != NULL)
2345 if (user_msg == NULL)
2349 va_start(ap, defaultrespond);
2350 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
2351 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
2352 smtp_printf("%s %s\r\n", code, buffer);
2356 smtp_respond(code, 3, TRUE, user_msg);
2364 /*************************************************
2365 * Verify HELO argument *
2366 *************************************************/
2368 /* This function is called if helo_verify_hosts or helo_try_verify_hosts is
2369 matched. It is also called from ACL processing if verify = helo is used and
2370 verification was not previously tried (i.e. helo_try_verify_hosts was not
2371 matched). The result of its processing is to set helo_verified and
2372 helo_verify_failed. These variables should both be FALSE for this function to
2375 Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
2376 for IPv6 ::ffff: literals.
2379 Returns: TRUE if testing was completed;
2380 FALSE on a temporary failure
2384 smtp_verify_helo(void)
2388 HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
2391 if (sender_helo_name == NULL)
2393 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
2396 /* Deal with the case of -bs without an IP address */
2398 else if (sender_host_address == NULL)
2400 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
2401 helo_verified = TRUE;
2404 /* Deal with the more common case when there is a sending IP address */
2406 else if (sender_helo_name[0] == '[')
2408 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
2409 Ustrlen(sender_host_address)) == 0;
2414 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
2415 helo_verified = Ustrncmp(sender_helo_name + 1,
2416 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
2421 { if (helo_verified) debug_printf("matched host address\n"); }
2424 /* Do a reverse lookup if one hasn't already given a positive or negative
2425 response. If that fails, or the name doesn't match, try checking with a forward
2430 if (sender_host_name == NULL && !host_lookup_failed)
2431 yield = host_name_lookup() != DEFER;
2433 /* If a host name is known, check it and all its aliases. */
2435 if (sender_host_name != NULL)
2437 helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0;
2441 HDEBUG(D_receive) debug_printf("matched host name\n");
2445 uschar **aliases = sender_host_aliases;
2446 while (*aliases != NULL)
2448 helo_verified = strcmpic(*aliases++, sender_helo_name) == 0;
2449 if (helo_verified) break;
2454 debug_printf("matched alias %s\n", *(--aliases));
2459 /* Final attempt: try a forward lookup of the helo name */
2465 h.name = sender_helo_name;
2469 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
2471 rc = host_find_byname(&h, NULL, 0, NULL, TRUE);
2472 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2477 if (Ustrcmp(hh->address, sender_host_address) == 0)
2479 helo_verified = TRUE;
2481 debug_printf("IP address for %s matches calling address\n",
2491 if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
2498 /*************************************************
2499 * Send user response message *
2500 *************************************************/
2502 /* This function is passed a default response code and a user message. It calls
2503 smtp_message_code() to check and possibly modify the response code, and then
2504 calls smtp_respond() to transmit the response. I put this into a function
2505 just to avoid a lot of repetition.
2508 code the response code
2509 user_msg the user message
2515 smtp_user_msg(uschar *code, uschar *user_msg)
2518 smtp_message_code(&code, &len, &user_msg, NULL);
2519 smtp_respond(code, len, TRUE, user_msg);
2525 /*************************************************
2526 * Initialize for SMTP incoming message *
2527 *************************************************/
2529 /* This function conducts the initial dialogue at the start of an incoming SMTP
2530 message, and builds a list of recipients. However, if the incoming message
2531 is part of a batch (-bS option) a separate function is called since it would
2532 be messy having tests splattered about all over this function. This function
2533 therefore handles the case where interaction is occurring. The input and output
2534 files are set up in smtp_in and smtp_out.
2536 The global recipients_list is set to point to a vector of recipient_item
2537 blocks, whose number is given by recipients_count. This is extended by the
2538 receive_add_recipient() function. The global variable sender_address is set to
2539 the sender's address. The yield is +1 if a message has been successfully
2540 started, 0 if a QUIT command was encountered or the connection was refused from
2541 the particular host, or -1 if the connection was lost.
2545 Returns: > 0 message successfully started (reached DATA)
2546 = 0 QUIT read or end of file reached or call refused
2551 smtp_setup_msg(void)
2554 BOOL toomany = FALSE;
2555 BOOL discarded = FALSE;
2556 BOOL last_was_rej_mail = FALSE;
2557 BOOL last_was_rcpt = FALSE;
2558 void *reset_point = store_get(0);
2560 DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
2562 /* Reset for start of new message. We allow one RSET not to be counted as a
2563 nonmail command, for those MTAs that insist on sending it between every
2564 message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
2565 TLS between messages (an Exim client may do this if it has messages queued up
2566 for the host). Note: we do NOT reset AUTH at this point. */
2568 smtp_reset(reset_point);
2569 message_ended = END_NOTSTARTED;
2571 cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
2572 cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
2573 cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
2575 cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
2578 /* Set the local signal handler for SIGTERM - it tries to end off tidily */
2580 os_non_restarting_signal(SIGTERM, command_sigterm_handler);
2582 /* Batched SMTP is handled in a different function. */
2584 if (smtp_batched_input) return smtp_setup_batch_msg();
2586 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2587 value. The values are 2 larger than the required yield of the function. */
2592 uschar *etrn_command;
2593 uschar *etrn_serialize_key;
2595 uschar *log_msg, *smtp_code;
2596 uschar *user_msg = NULL;
2597 uschar *recipient = NULL;
2598 uschar *hello = NULL;
2599 uschar *set_id = NULL;
2601 BOOL was_rej_mail = FALSE;
2602 BOOL was_rcpt = FALSE;
2603 void (*oldsignal)(int);
2605 int start, end, sender_domain, recipient_domain;
2610 switch(smtp_read_command(TRUE))
2612 /* The AUTH command is not permitted to occur inside a transaction, and may
2613 occur successfully only once per connection. Actually, that isn't quite
2614 true. When TLS is started, all previous information about a connection must
2615 be discarded, so a new AUTH is permitted at that time.
2617 AUTH may only be used when it has been advertised. However, it seems that
2618 there are clients that send AUTH when it hasn't been advertised, some of
2619 them even doing this after HELO. And there are MTAs that accept this. Sigh.
2620 So there's a get-out that allows this to happen.
2622 AUTH is initially labelled as a "nonmail command" so that one occurrence
2623 doesn't get counted. We change the label here so that multiple failing
2624 AUTHS will eventually hit the nonmail threshold. */
2628 authentication_failed = TRUE;
2629 cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
2631 if (!auth_advertised && !allow_auth_unadvertised)
2633 done = synprot_error(L_smtp_protocol_error, 503, NULL,
2634 US"AUTH command used when not advertised");
2637 if (sender_host_authenticated != NULL)
2639 done = synprot_error(L_smtp_protocol_error, 503, NULL,
2640 US"already authenticated");
2643 if (sender_address != NULL)
2645 done = synprot_error(L_smtp_protocol_error, 503, NULL,
2646 US"not permitted in mail transaction");
2652 if (acl_smtp_auth != NULL)
2654 rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg);
2657 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
2662 /* Find the name of the requested authentication mechanism. */
2665 while ((c = *smtp_cmd_data) != 0 && !isspace(c))
2667 if (!isalnum(c) && c != '-' && c != '_')
2669 done = synprot_error(L_smtp_syntax_error, 501, NULL,
2670 US"invalid character in authentication mechanism name");
2676 /* If not at the end of the line, we must be at white space. Terminate the
2677 name and move the pointer on to any data that may be present. */
2679 if (*smtp_cmd_data != 0)
2681 *smtp_cmd_data++ = 0;
2682 while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
2685 /* Search for an authentication mechanism which is configured for use
2686 as a server and which has been advertised (unless, sigh, allow_auth_
2687 unadvertised is set). */
2689 for (au = auths; au != NULL; au = au->next)
2691 if (strcmpic(s, au->public_name) == 0 && au->server &&
2692 (au->advertised || allow_auth_unadvertised)) break;
2697 done = synprot_error(L_smtp_protocol_error, 504, NULL,
2698 string_sprintf("%s authentication mechanism not supported", s));
2702 /* Run the checking code, passing the remainder of the command line as
2703 data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
2704 it as the only set numerical variable. The authenticator may set $auth<n>
2705 and also set other numeric variables. The $auth<n> variables are preferred
2706 nowadays; the numerical variables remain for backwards compatibility.
2708 Afterwards, have a go at expanding the set_id string, even if
2709 authentication failed - for bad passwords it can be useful to log the
2710 userid. On success, require set_id to expand and exist, and put it in
2711 authenticated_id. Save this in permanent store, as the working store gets
2712 reset at HELO, RSET, etc. */
2714 for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
2716 expand_nlength[0] = 0; /* $0 contains nothing */
2718 c = (au->info->servercode)(au, smtp_cmd_data);
2719 if (au->set_id != NULL) set_id = expand_string(au->set_id);
2720 expand_nmax = -1; /* Reset numeric variables */
2721 for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
2723 /* The value of authenticated_id is stored in the spool file and printed in
2724 log lines. It must not contain binary zeros or newline characters. In
2725 normal use, it never will, but when playing around or testing, this error
2726 can (did) happen. To guard against this, ensure that the id contains only
2727 printing characters. */
2729 if (set_id != NULL) set_id = string_printing(set_id);
2731 /* For the non-OK cases, set up additional logging data if set_id
2736 if (set_id != NULL && *set_id != 0)
2737 set_id = string_sprintf(" (set_id=%s)", set_id);
2741 /* Switch on the result */
2746 if (au->set_id == NULL || set_id != NULL) /* Complete success */
2748 if (set_id != NULL) authenticated_id = string_copy_malloc(set_id);
2749 sender_host_authenticated = au->name;
2750 authentication_failed = FALSE;
2752 protocols[pextend + pauthed + ((tls_active >= 0)? pcrpted:0)] +
2753 ((sender_host_address != NULL)? pnlocal : 0);
2754 s = ss = US"235 Authentication succeeded";
2755 authenticated_by = au;
2759 /* Authentication succeeded, but we failed to expand the set_id string.
2760 Treat this as a temporary error. */
2762 auth_defer_msg = expand_string_message;
2766 s = string_sprintf("435 Unable to authenticate at present%s",
2767 auth_defer_user_msg);
2768 ss = string_sprintf("435 Unable to authenticate at present%s: %s",
2769 set_id, auth_defer_msg);
2773 s = ss = US"501 Invalid base64 data";
2777 s = ss = US"501 Authentication cancelled";
2781 s = ss = US"553 Initial data not expected";
2785 s = US"535 Incorrect authentication data";
2786 ss = string_sprintf("535 Incorrect authentication data%s", set_id);
2790 s = US"435 Internal error";
2791 ss = string_sprintf("435 Internal error%s: return %d from authentication "
2792 "check", set_id, c);
2796 smtp_printf("%s\r\n", s);
2798 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
2799 au->name, host_and_ident(FALSE), ss);
2801 break; /* AUTH_CMD */
2803 /* The HELO/EHLO commands are permitted to appear in the middle of a
2804 session as well as at the beginning. They have the effect of a reset in
2805 addition to their other functions. Their absence at the start cannot be
2806 taken to be an error.
2810 If the EHLO command is not acceptable to the SMTP server, 501, 500,
2811 or 502 failure replies MUST be returned as appropriate. The SMTP
2812 server MUST stay in the same state after transmitting these replies
2813 that it was in before the EHLO was received.
2815 Therefore, we do not do the reset until after checking the command for
2816 acceptability. This change was made for Exim release 4.11. Previously
2817 it did the reset first. */
2830 HELO_EHLO: /* Common code for HELO and EHLO */
2831 cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
2832 cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
2834 /* Reject the HELO if its argument was invalid or non-existent. A
2835 successful check causes the argument to be saved in malloc store. */
2837 if (!check_helo(smtp_cmd_data))
2839 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello);
2841 log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
2842 "invalid argument(s): %s", hello, host_and_ident(FALSE),
2843 (*smtp_cmd_argument == 0)? US"(no argument given)" :
2844 string_printing(smtp_cmd_argument));
2846 if (++synprot_error_count > smtp_max_synprot_errors)
2848 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2849 "syntax or protocol errors (last command was \"%s\")",
2850 host_and_ident(FALSE), smtp_cmd_buffer);
2857 /* If sender_host_unknown is true, we have got here via the -bs interface,
2858 not called from inetd. Otherwise, we are running an IP connection and the
2859 host address will be set. If the helo name is the primary name of this
2860 host and we haven't done a reverse lookup, force one now. If helo_required
2861 is set, ensure that the HELO name matches the actual host. If helo_verify
2862 is set, do the same check, but softly. */
2864 if (!sender_host_unknown)
2866 BOOL old_helo_verified = helo_verified;
2867 uschar *p = smtp_cmd_data;
2869 while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
2872 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
2873 because otherwise the log can be confusing. */
2875 if (sender_host_name == NULL &&
2876 (deliver_domain = sender_helo_name, /* set $domain */
2877 match_isinlist(sender_helo_name, &helo_lookup_domains, 0,
2878 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK)
2879 (void)host_name_lookup();
2881 /* Rebuild the fullhost info to include the HELO name (and the real name
2882 if it was looked up.) */
2884 host_build_sender_fullhost(); /* Rebuild */
2885 set_process_info("handling%s incoming connection from %s",
2886 (tls_active >= 0)? " TLS" : "", host_and_ident(FALSE));
2888 /* Verify if configured. This doesn't give much security, but it does
2889 make some people happy to be able to do it. If helo_required is set,
2890 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
2891 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
2892 now obsolescent, since the verification can now be requested selectively
2895 helo_verified = helo_verify_failed = FALSE;
2896 if (helo_required || helo_verify)
2898 BOOL tempfail = !smtp_verify_helo();
2903 smtp_printf("%d %s argument does not match calling host\r\n",
2904 tempfail? 451 : 550, hello);
2905 log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
2906 tempfail? "temporarily " : "",
2907 hello, sender_helo_name, host_and_ident(FALSE));
2908 helo_verified = old_helo_verified;
2909 break; /* End of HELO/EHLO processing */
2911 HDEBUG(D_all) debug_printf("%s verification failed but host is in "
2912 "helo_try_verify_hosts\n", hello);
2917 #ifdef EXPERIMENTAL_SPF
2918 /* set up SPF context */
2919 spf_init(sender_helo_name, sender_host_address);
2922 /* Apply an ACL check if one is defined; afterwards, recheck
2923 synchronization in case the client started sending in a delay. */
2925 if (acl_smtp_helo != NULL)
2927 rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg);
2930 done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
2931 sender_helo_name = NULL;
2932 host_build_sender_fullhost(); /* Rebuild */
2935 else if (!check_sync()) goto SYNC_FAILURE;
2938 /* Generate an OK reply. The default string includes the ident if present,
2939 and also the IP address if present. Reflecting back the ident is intended
2940 as a deterrent to mail forgers. For maximum efficiency, and also because
2941 some broken systems expect each response to be in a single packet, arrange
2942 that the entire reply is sent in one write(). */
2944 auth_advertised = FALSE;
2945 pipelining_advertised = FALSE;
2947 tls_advertised = FALSE;
2950 smtp_code = US"250 "; /* Default response code plus space*/
2951 if (user_msg == NULL)
2953 s = string_sprintf("%.3s %s Hello %s%s%s",
2955 smtp_active_hostname,
2956 (sender_ident == NULL)? US"" : sender_ident,
2957 (sender_ident == NULL)? US"" : US" at ",
2958 (sender_host_name == NULL)? sender_helo_name : sender_host_name);
2963 if (sender_host_address != NULL)
2965 s = string_cat(s, &size, &ptr, US" [", 2);
2966 s = string_cat(s, &size, &ptr, sender_host_address,
2967 Ustrlen(sender_host_address));
2968 s = string_cat(s, &size, &ptr, US"]", 1);
2972 /* A user-supplied EHLO greeting may not contain more than one line. Note
2973 that the code returned by smtp_message_code() includes the terminating
2974 whitespace character. */
2980 smtp_message_code(&smtp_code, &codelen, &user_msg, NULL);
2981 s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
2982 if ((ss = strpbrk(CS s, "\r\n")) != NULL)
2984 log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
2985 "newlines: message truncated: %s", string_printing(s));
2992 s = string_cat(s, &size, &ptr, US"\r\n", 2);
2994 /* If we received EHLO, we must create a multiline response which includes
2995 the functions supported. */
3001 /* I'm not entirely happy with this, as an MTA is supposed to check
3002 that it has enough room to accept a message of maximum size before
3003 it sends this. However, there seems little point in not sending it.
3004 The actual size check happens later at MAIL FROM time. By postponing it
3005 till then, VRFY and EXPN can be used after EHLO when space is short. */
3007 if (thismessage_size_limit > 0)
3009 sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code,
3010 thismessage_size_limit);
3011 s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer));
3015 s = string_cat(s, &size, &ptr, smtp_code, 3);
3016 s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7);
3019 /* Exim does not do protocol conversion or data conversion. It is 8-bit
3020 clean; if it has an 8-bit character in its hand, it just sends it. It
3021 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
3022 However, some users want this option simply in order to stop MUAs
3023 mangling messages that contain top-bit-set characters. It is therefore
3024 provided as an option. */
3026 if (accept_8bitmime)
3028 s = string_cat(s, &size, &ptr, smtp_code, 3);
3029 s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11);
3032 /* Advertise ETRN if there's an ACL checking whether a host is
3033 permitted to issue it; a check is made when any host actually tries. */
3035 if (acl_smtp_etrn != NULL)
3037 s = string_cat(s, &size, &ptr, smtp_code, 3);
3038 s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7);
3041 /* Advertise EXPN if there's an ACL checking whether a host is
3042 permitted to issue it; a check is made when any host actually tries. */
3044 if (acl_smtp_expn != NULL)
3046 s = string_cat(s, &size, &ptr, smtp_code, 3);
3047 s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7);
3050 /* Exim is quite happy with pipelining, so let the other end know that
3051 it is safe to use it, unless advertising is disabled. */
3053 if (pipelining_enable &&
3054 verify_check_host(&pipelining_advertise_hosts) == OK)
3056 s = string_cat(s, &size, &ptr, smtp_code, 3);
3057 s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13);
3058 sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
3059 pipelining_advertised = TRUE;
3062 /* If any server authentication mechanisms are configured, advertise
3063 them if the current host is in auth_advertise_hosts. The problem with
3064 advertising always is that some clients then require users to
3065 authenticate (and aren't configurable otherwise) even though it may not
3066 be necessary (e.g. if the host is in host_accept_relay).
3068 RFC 2222 states that SASL mechanism names contain only upper case
3069 letters, so output the names in upper case, though we actually recognize
3070 them in either case in the AUTH command. */
3074 if (verify_check_host(&auth_advertise_hosts) == OK)
3078 for (au = auths; au != NULL; au = au->next)
3080 if (au->server && (au->advertise_condition == NULL ||
3081 expand_check_condition(au->advertise_condition, au->name,
3082 US"authenticator")))
3087 s = string_cat(s, &size, &ptr, smtp_code, 3);
3088 s = string_cat(s, &size, &ptr, US"-AUTH", 5);
3090 auth_advertised = TRUE;
3093 s = string_cat(s, &size, &ptr, US" ", 1);
3094 s = string_cat(s, &size, &ptr, au->public_name,
3095 Ustrlen(au->public_name));
3096 while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]);
3097 au->advertised = TRUE;
3099 else au->advertised = FALSE;
3101 if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2);
3105 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
3106 if it has been included in the binary, and the host matches
3107 tls_advertise_hosts. We must *not* advertise if we are already in a
3108 secure connection. */
3111 if (tls_active < 0 &&
3112 verify_check_host(&tls_advertise_hosts) != FAIL)
3114 s = string_cat(s, &size, &ptr, smtp_code, 3);
3115 s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11);
3116 tls_advertised = TRUE;
3120 /* Finish off the multiline reply with one that is always available. */
3122 s = string_cat(s, &size, &ptr, smtp_code, 3);
3123 s = string_cat(s, &size, &ptr, US" HELP\r\n", 7);
3126 /* Terminate the string (for debug), write it, and note that HELO/EHLO
3132 if (tls_active >= 0) (void)tls_write(s, ptr); else
3135 (void)fwrite(s, 1, ptr, smtp_out);
3139 while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */
3140 memmove(cr, cr + 1, (ptr--) - (cr - s));
3141 debug_printf("SMTP>> %s", s);
3145 /* Reset the protocol and the state, abandoning any previous message. */
3147 received_protocol = (esmtp?
3149 ((sender_host_authenticated != NULL)? pauthed : 0) +
3150 ((tls_active >= 0)? pcrpted : 0)]
3152 protocols[pnormal + ((tls_active >= 0)? pcrpted : 0)])
3154 ((sender_host_address != NULL)? pnlocal : 0);
3156 smtp_reset(reset_point);
3158 break; /* HELO/EHLO */
3161 /* The MAIL command requires an address as an operand. All we do
3162 here is to parse it for syntactic correctness. The form "<>" is
3163 a special case which converts into an empty string. The start/end
3164 pointers in the original are not used further for this address, as
3165 it is the canonical extracted address which is all that is kept. */
3169 smtp_mailcmd_count++; /* Count for limit and ratelimit */
3170 was_rej_mail = TRUE; /* Reset if accepted */
3172 if (helo_required && !helo_seen)
3174 smtp_printf("503 HELO or EHLO required\r\n");
3175 log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no "
3176 "HELO/EHLO given", host_and_ident(FALSE));
3180 if (sender_address != NULL)
3182 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3183 US"sender already given");
3187 if (smtp_cmd_data[0] == 0)
3189 done = synprot_error(L_smtp_protocol_error, 501, NULL,
3190 US"MAIL must have an address operand");
3194 /* Check to see if the limit for messages per connection would be
3195 exceeded by accepting further messages. */
3197 if (smtp_accept_max_per_connection > 0 &&
3198 smtp_mailcmd_count > smtp_accept_max_per_connection)
3200 smtp_printf("421 too many messages in this connection\r\n");
3201 log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many "
3202 "messages in one connection", host_and_ident(TRUE));
3206 /* Reset for start of message - even if this is going to fail, we
3207 obviously need to throw away any previous data. */
3209 smtp_reset(reset_point);
3211 sender_data = recipient_data = NULL;
3213 /* Loop, checking for ESMTP additions to the MAIL FROM command. */
3217 uschar *name, *value, *end;
3218 unsigned long int size;
3220 if (!extract_option(&name, &value)) break;
3222 /* Handle SIZE= by reading the value. We don't do the check till later,
3223 in order to be able to log the sender address on failure. */
3225 if (strcmpic(name, US"SIZE") == 0 &&
3226 ((size = Ustrtoul(value, &end, 10)), *end == 0))
3228 if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX)
3230 message_size = (int)size;
3233 /* If this session was initiated with EHLO and accept_8bitmime is set,
3234 Exim will have indicated that it supports the BODY=8BITMIME option. In
3235 fact, it does not support this according to the RFCs, in that it does not
3236 take any special action for forwarding messages containing 8-bit
3237 characters. That is why accept_8bitmime is not the default setting, but
3238 some sites want the action that is provided. We recognize both "8BITMIME"
3239 and "7BIT" as body types, but take no action. */
3241 else if (accept_8bitmime && strcmpic(name, US"BODY") == 0 &&
3242 (strcmpic(value, US"8BITMIME") == 0 ||
3243 strcmpic(value, US"7BIT") == 0)) {}
3245 /* Handle the AUTH extension. If the value given is not "<>" and either
3246 the ACL says "yes" or there is no ACL but the sending host is
3247 authenticated, we set it up as the authenticated sender. However, if the
3248 authenticator set a condition to be tested, we ignore AUTH on MAIL unless
3249 the condition is met. The value of AUTH is an xtext, which means that +,
3250 = and cntrl chars are coded in hex; however "<>" is unaffected by this
3253 else if (strcmpic(name, US"AUTH") == 0)
3255 if (Ustrcmp(value, "<>") != 0)
3260 if (auth_xtextdecode(value, &authenticated_sender) < 0)
3262 /* Put back terminator overrides for error message */
3265 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3266 US"invalid data for AUTH");
3270 if (acl_smtp_mailauth == NULL)
3272 ignore_msg = US"client not authenticated";
3273 rc = (sender_host_authenticated != NULL)? OK : FAIL;
3277 ignore_msg = US"rejected by ACL";
3278 rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth,
3279 &user_msg, &log_msg);
3285 if (authenticated_by == NULL ||
3286 authenticated_by->mail_auth_condition == NULL ||
3287 expand_check_condition(authenticated_by->mail_auth_condition,
3288 authenticated_by->name, US"authenticator"))
3289 break; /* Accept the AUTH */
3291 ignore_msg = US"server_mail_auth_condition failed";
3292 if (authenticated_id != NULL)
3293 ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"",
3294 ignore_msg, authenticated_id);
3299 authenticated_sender = NULL;
3300 log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)",
3301 value, host_and_ident(TRUE), ignore_msg);
3304 /* Should only get DEFER or ERROR here. Put back terminator
3305 overrides for error message */
3310 (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg,
3317 /* Unknown option. Stick back the terminator characters and break
3318 the loop. An error for a malformed address will occur. */
3328 /* If we have passed the threshold for rate limiting, apply the current
3329 delay, and update it for next time, provided this is a limited host. */
3331 if (smtp_mailcmd_count > smtp_rlm_threshold &&
3332 verify_check_host(&smtp_ratelimit_hosts) == OK)
3334 DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n",
3335 smtp_delay_mail/1000.0);
3336 millisleep((int)smtp_delay_mail);
3337 smtp_delay_mail *= smtp_rlm_factor;
3338 if (smtp_delay_mail > (double)smtp_rlm_limit)
3339 smtp_delay_mail = (double)smtp_rlm_limit;
3342 /* Now extract the address, first applying any SMTP-time rewriting. The
3343 TRUE flag allows "<>" as a sender address. */
3345 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
3346 rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
3347 global_rewrite_rules) : smtp_cmd_data;
3349 /* rfc821_domains = TRUE; << no longer needed */
3351 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
3353 /* rfc821_domains = FALSE; << no longer needed */
3355 if (raw_sender == NULL)
3357 done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
3361 sender_address = raw_sender;
3363 /* If there is a configured size limit for mail, check that this message
3364 doesn't exceed it. The check is postponed to this point so that the sender
3367 if (thismessage_size_limit > 0 && message_size > thismessage_size_limit)
3369 smtp_printf("552 Message size exceeds maximum permitted\r\n");
3370 log_write(L_size_reject,
3371 LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: "
3372 "message too big: size%s=%d max=%d",
3374 host_and_ident(TRUE),
3375 (message_size == INT_MAX)? ">" : "",
3377 thismessage_size_limit);
3378 sender_address = NULL;
3382 /* Check there is enough space on the disk unless configured not to.
3383 When smtp_check_spool_space is set, the check is for thismessage_size_limit
3384 plus the current message - i.e. we accept the message only if it won't
3385 reduce the space below the threshold. Add 5000 to the size to allow for
3386 overheads such as the Received: line and storing of recipients, etc.
3387 By putting the check here, even when SIZE is not given, it allow VRFY
3388 and EXPN etc. to be used when space is short. */
3390 if (!receive_check_fs(
3391 (smtp_check_spool_space && message_size >= 0)?
3392 message_size + 5000 : 0))
3394 smtp_printf("452 Space shortage, please try later\r\n");
3395 sender_address = NULL;
3399 /* If sender_address is unqualified, reject it, unless this is a locally
3400 generated message, or the sending host or net is permitted to send
3401 unqualified addresses - typically local machines behaving as MUAs -
3402 in which case just qualify the address. The flag is set above at the start
3403 of the SMTP connection. */
3405 if (sender_domain == 0 && sender_address[0] != 0)
3407 if (allow_unqualified_sender)
3409 sender_domain = Ustrlen(sender_address) + 1;
3410 sender_address = rewrite_address_qualify(sender_address, FALSE);
3411 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
3416 smtp_printf("501 %s: sender address must contain a domain\r\n",
3418 log_write(L_smtp_syntax_error,
3419 LOG_MAIN|LOG_REJECT,
3420 "unqualified sender rejected: <%s> %s%s",
3422 host_and_ident(TRUE),
3424 sender_address = NULL;
3429 /* Apply an ACL check if one is defined, before responding. Afterwards,
3430 when pipelining is not advertised, do another sync check in case the ACL
3431 delayed and the client started sending in the meantime. */
3433 if (acl_smtp_mail == NULL) rc = OK; else
3435 rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
3436 if (rc == OK && !pipelining_advertised && !check_sync())
3440 if (rc == OK || rc == DISCARD)
3442 if (user_msg == NULL) smtp_printf("250 OK\r\n");
3443 else smtp_user_msg(US"250", user_msg);
3444 smtp_delay_rcpt = smtp_rlr_base;
3445 recipients_discarded = (rc == DISCARD);
3446 was_rej_mail = FALSE;
3450 done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg);
3451 sender_address = NULL;
3456 /* The RCPT command requires an address as an operand. There may be any
3457 number of RCPT commands, specifying multiple recipients. We build them all
3458 into a data structure. The start/end values given by parse_extract_address
3459 are not used, as we keep only the extracted address. */
3464 was_rcpt = rcpt_in_progress = TRUE;
3466 /* There must be a sender address; if the sender was rejected and
3467 pipelining was advertised, we assume the client was pipelining, and do not
3468 count this as a protocol error. Reset was_rej_mail so that further RCPTs
3469 get the same treatment. */
3471 if (sender_address == NULL)
3473 if (pipelining_advertised && last_was_rej_mail)
3475 smtp_printf("503 sender not yet given\r\n");
3476 was_rej_mail = TRUE;
3480 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3481 US"sender not yet given");
3482 was_rcpt = FALSE; /* Not a valid RCPT */
3488 /* Check for an operand */
3490 if (smtp_cmd_data[0] == 0)
3492 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3493 US"RCPT must have an address operand");
3498 /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
3499 as a recipient address */
3501 recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
3502 rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
3503 global_rewrite_rules) : smtp_cmd_data;
3505 /* rfc821_domains = TRUE; << no longer needed */
3506 recipient = parse_extract_address(recipient, &errmess, &start, &end,
3507 &recipient_domain, FALSE);
3508 /* rfc821_domains = FALSE; << no longer needed */
3510 if (recipient == NULL)
3512 done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
3517 /* If the recipient address is unqualified, reject it, unless this is a
3518 locally generated message. However, unqualified addresses are permitted
3519 from a configured list of hosts and nets - typically when behaving as
3520 MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
3521 really. The flag is set at the start of the SMTP connection.
3523 RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
3524 assumed this meant "reserved local part", but the revision of RFC 821 and
3525 friends now makes it absolutely clear that it means *mailbox*. Consequently
3526 we must always qualify this address, regardless. */
3528 if (recipient_domain == 0)
3530 if (allow_unqualified_recipient ||
3531 strcmpic(recipient, US"postmaster") == 0)
3533 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
3535 recipient_domain = Ustrlen(recipient) + 1;
3536 recipient = rewrite_address_qualify(recipient, TRUE);
3541 smtp_printf("501 %s: recipient address must contain a domain\r\n",
3543 log_write(L_smtp_syntax_error,
3544 LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: "
3545 "<%s> %s%s", recipient, host_and_ident(TRUE),
3551 /* Check maximum allowed */
3553 if (rcpt_count > recipients_max && recipients_max > 0)
3555 if (recipients_max_reject)
3558 smtp_printf("552 too many recipients\r\n");
3560 log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message "
3561 "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE));
3566 smtp_printf("452 too many recipients\r\n");
3568 log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess "
3569 "temporarily rejected: sender=<%s> %s", sender_address,
3570 host_and_ident(TRUE));
3577 /* If we have passed the threshold for rate limiting, apply the current
3578 delay, and update it for next time, provided this is a limited host. */
3580 if (rcpt_count > smtp_rlr_threshold &&
3581 verify_check_host(&smtp_ratelimit_hosts) == OK)
3583 DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n",
3584 smtp_delay_rcpt/1000.0);
3585 millisleep((int)smtp_delay_rcpt);
3586 smtp_delay_rcpt *= smtp_rlr_factor;
3587 if (smtp_delay_rcpt > (double)smtp_rlr_limit)
3588 smtp_delay_rcpt = (double)smtp_rlr_limit;
3591 /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
3592 for them. Otherwise, check the access control list for this recipient. As
3593 there may be a delay in this, re-check for a synchronization error
3594 afterwards, unless pipelining was advertised. */
3596 if (recipients_discarded) rc = DISCARD; else
3598 rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
3600 if (rc == OK && !pipelining_advertised && !check_sync())
3604 /* The ACL was happy */
3608 if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
3609 else smtp_user_msg(US"250", user_msg);
3610 receive_add_recipient(recipient, -1);
3613 /* The recipient was discarded */
3615 else if (rc == DISCARD)
3617 if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
3618 else smtp_user_msg(US"250", user_msg);
3621 log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> rejected RCPT %s: "
3622 "discarded by %s ACL%s%s", host_and_ident(TRUE),
3623 (sender_address_unrewritten != NULL)?
3624 sender_address_unrewritten : sender_address,
3625 smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT",
3626 (log_msg == NULL)? US"" : US": ",
3627 (log_msg == NULL)? US"" : log_msg);
3630 /* Either the ACL failed the address, or it was deferred. */
3634 if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++;
3635 done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg);
3640 /* The DATA command is legal only if it follows successful MAIL FROM
3641 and RCPT TO commands. However, if pipelining is advertised, a bad DATA is
3642 not counted as a protocol error if it follows RCPT (which must have been
3643 rejected if there are no recipients.) This function is complete when a
3644 valid DATA command is encountered.
3646 Note concerning the code used: RFC 2821 says this:
3648 - If there was no MAIL, or no RCPT, command, or all such commands
3649 were rejected, the server MAY return a "command out of sequence"
3650 (503) or "no valid recipients" (554) reply in response to the
3653 The example in the pipelining RFC 2920 uses 554, but I use 503 here
3654 because it is the same whether pipelining is in use or not.
3656 If all the RCPT commands that precede DATA provoked the same error message
3657 (often indicating some kind of system error), it is helpful to include it
3658 with the DATA rejection (an idea suggested by Tony Finch). */
3662 if (!discarded && recipients_count <= 0)
3664 if (rcpt_smtp_response_same && rcpt_smtp_response != NULL)
3666 uschar *code = US"503";
3667 int len = Ustrlen(rcpt_smtp_response);
3668 smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with "
3670 /* Responses from smtp_printf() will have \r\n on the end */
3671 if (len > 2 && rcpt_smtp_response[len-2] == '\r')
3672 rcpt_smtp_response[len-2] = 0;
3673 smtp_respond(code, 3, FALSE, rcpt_smtp_response);
3675 if (pipelining_advertised && last_was_rcpt)
3676 smtp_printf("503 Valid RCPT command must precede DATA\r\n");
3678 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3679 US"valid RCPT command must precede DATA");
3683 if (toomany && recipients_max_reject)
3685 sender_address = NULL; /* This will allow a new MAIL without RSET */
3686 sender_address_unrewritten = NULL;
3687 smtp_printf("554 Too many recipients\r\n");
3691 /* If there is an ACL, re-check the synchronization afterwards, since the
3692 ACL may have delayed. */
3694 if (acl_smtp_predata == NULL) rc = OK; else
3696 enable_dollar_recipients = TRUE;
3697 rc = acl_check(ACL_WHERE_PREDATA, NULL, acl_smtp_predata, &user_msg,
3699 enable_dollar_recipients = FALSE;
3700 if (rc == OK && !check_sync()) goto SYNC_FAILURE;
3705 if (user_msg == NULL)
3706 smtp_printf("354 Enter message, ending with \".\" on a line by itself\r\n");
3707 else smtp_user_msg(US"354", user_msg);
3709 message_ended = END_NOTENDED; /* Indicate in middle of data */
3712 /* Either the ACL failed the address, or it was deferred. */
3715 done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
3721 rc = acl_check(ACL_WHERE_VRFY, NULL, acl_smtp_vrfy, &user_msg, &log_msg);
3723 done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg);
3729 /* rfc821_domains = TRUE; << no longer needed */
3730 address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end,
3731 &recipient_domain, FALSE);
3732 /* rfc821_domains = FALSE; << no longer needed */
3734 if (address == NULL)
3735 s = string_sprintf("501 %s", errmess);
3738 address_item *addr = deliver_make_addr(address, FALSE);
3739 switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1,
3740 -1, -1, NULL, NULL, NULL))
3743 s = string_sprintf("250 <%s> is deliverable", address);
3747 s = (addr->user_message != NULL)?
3748 string_sprintf("451 <%s> %s", address, addr->user_message) :
3749 string_sprintf("451 Cannot resolve <%s> at this time", address);
3753 s = (addr->user_message != NULL)?
3754 string_sprintf("550 <%s> %s", address, addr->user_message) :
3755 string_sprintf("550 <%s> is not deliverable", address);
3756 log_write(0, LOG_MAIN, "VRFY failed for %s %s",
3757 smtp_cmd_argument, host_and_ident(TRUE));
3762 smtp_printf("%s\r\n", s);
3769 rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg);
3771 done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg);
3774 BOOL save_log_testing_mode = log_testing_mode;
3775 address_test_mode = log_testing_mode = TRUE;
3776 (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE),
3777 smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1,
3779 address_test_mode = FALSE;
3780 log_testing_mode = save_log_testing_mode; /* true for -bh */
3789 if (!tls_advertised)
3791 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3792 US"STARTTLS command used when not advertised");
3796 /* Apply an ACL check if one is defined */
3798 if (acl_smtp_starttls != NULL)
3800 rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, &user_msg,
3804 done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg);
3809 /* RFC 2487 is not clear on when this command may be sent, though it
3810 does state that all information previously obtained from the client
3811 must be discarded if a TLS session is started. It seems reasonble to
3812 do an implied RSET when STARTTLS is received. */
3814 incomplete_transaction_log(US"STARTTLS");
3815 smtp_reset(reset_point);
3817 cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE;
3819 /* Attempt to start up a TLS session, and if successful, discard all
3820 knowledge that was obtained previously. At least, that's what the RFC says,
3821 and that's what happens by default. However, in order to work round YAEB,
3822 there is an option to remember the esmtp state. Sigh.
3824 We must allow for an extra EHLO command and an extra AUTH command after
3825 STARTTLS that don't add to the nonmail command count. */
3827 if ((rc = tls_server_start(tls_require_ciphers, gnutls_require_mac,
3828 gnutls_require_kx, gnutls_require_proto)) == OK)
3830 if (!tls_remember_esmtp)
3831 helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE;
3832 cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
3833 cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE;
3834 if (sender_helo_name != NULL)
3836 store_free(sender_helo_name);
3837 sender_helo_name = NULL;
3838 host_build_sender_fullhost(); /* Rebuild */
3839 set_process_info("handling incoming TLS connection from %s",
3840 host_and_ident(FALSE));
3842 received_protocol = (esmtp?
3843 protocols[pextend + pcrpted +
3844 ((sender_host_authenticated != NULL)? pauthed : 0)]
3846 protocols[pnormal + pcrpted])
3848 ((sender_host_address != NULL)? pnlocal : 0);
3850 sender_host_authenticated = NULL;
3851 authenticated_id = NULL;
3852 sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
3853 DEBUG(D_tls) debug_printf("TLS active\n");
3854 break; /* Successful STARTTLS */
3857 /* Some local configuration problem was discovered before actually trying
3858 to do a TLS handshake; give a temporary error. */
3860 else if (rc == DEFER)
3862 smtp_printf("454 TLS currently unavailable\r\n");
3866 /* Hard failure. Reject everything except QUIT or closed connection. One
3867 cause for failure is a nested STARTTLS, in which case tls_active remains
3868 set, but we must still reject all incoming commands. */
3870 DEBUG(D_tls) debug_printf("TLS failed to start\n");
3873 switch(smtp_read_command(FALSE))
3876 log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF",
3877 smtp_get_connection_info());
3878 smtp_notquit_exit(US"tls-failed", NULL, NULL);
3882 /* It is perhaps arguable as to which exit ACL should be called here,
3883 but as it is probably a situtation that almost never arises, it
3884 probably doesn't matter. We choose to call the real QUIT ACL, which in
3885 some sense is perhaps "right". */
3889 if (acl_smtp_quit != NULL)
3891 rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg,
3894 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
3897 if (user_msg == NULL)
3898 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
3900 smtp_respond(US"221", 3, TRUE, user_msg);
3901 log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
3902 smtp_get_connection_info());
3907 smtp_printf("554 Security failure\r\n");
3916 /* The ACL for QUIT is provided for gathering statistical information or
3917 similar; it does not affect the response code, but it can supply a custom
3922 incomplete_transaction_log(US"QUIT");
3923 if (acl_smtp_quit != NULL)
3925 rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg);
3927 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
3930 if (user_msg == NULL)
3931 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
3933 smtp_respond(US"221", 3, TRUE, user_msg);
3940 log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
3941 smtp_get_connection_info());
3947 incomplete_transaction_log(US"RSET");
3948 smtp_reset(reset_point);
3950 smtp_printf("250 Reset OK\r\n");
3951 cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
3957 smtp_printf("250 OK\r\n");
3961 /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually
3962 used, a check will be done for permitted hosts. Show STARTTLS only if not
3963 already in a TLS session and if it would be advertised in the EHLO
3968 smtp_printf("214-Commands supported:\r\n");
3972 Ustrcat(buffer, " AUTH");
3974 if (tls_active < 0 &&
3975 verify_check_host(&tls_advertise_hosts) != FAIL)
3976 Ustrcat(buffer, " STARTTLS");
3978 Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA");
3979 Ustrcat(buffer, " NOOP QUIT RSET HELP");
3980 if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN");
3981 if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN");
3982 if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY");
3983 smtp_printf("214%s\r\n", buffer);
3989 incomplete_transaction_log(US"connection lost");
3990 smtp_notquit_exit(US"connection-lost", US"421",
3991 US"%s lost input connection", smtp_active_hostname);
3993 /* Don't log by default unless in the middle of a message, as some mailers
3994 just drop the call rather than sending QUIT, and it clutters up the logs.
3997 if (sender_address != NULL || recipients_count > 0)
3998 log_write(L_lost_incoming_connection,
4000 "unexpected %s while reading SMTP command from %s%s",
4001 sender_host_unknown? "EOF" : "disconnection",
4002 host_and_ident(FALSE), smtp_read_error);
4004 else log_write(L_smtp_connection, LOG_MAIN, "%s lost%s",
4005 smtp_get_connection_info(), smtp_read_error);
4013 if (sender_address != NULL)
4015 done = synprot_error(L_smtp_protocol_error, 503, NULL,
4016 US"ETRN is not permitted inside a transaction");
4020 log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument,
4021 host_and_ident(FALSE));
4023 rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, &user_msg, &log_msg);
4026 done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg);
4030 /* Compute the serialization key for this command. */
4032 etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data);
4034 /* If a command has been specified for running as a result of ETRN, we
4035 permit any argument to ETRN. If not, only the # standard form is permitted,
4036 since that is strictly the only kind of ETRN that can be implemented
4037 according to the RFC. */
4039 if (smtp_etrn_command != NULL)
4043 etrn_command = smtp_etrn_command;
4044 deliver_domain = smtp_cmd_data;
4045 rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL,
4046 US"ETRN processing", &error);
4047 deliver_domain = NULL;
4050 log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s",
4052 smtp_printf("458 Internal failure\r\n");
4057 /* Else set up to call Exim with the -R option. */
4061 if (*smtp_cmd_data++ != '#')
4063 done = synprot_error(L_smtp_syntax_error, 501, NULL,
4064 US"argument must begin with #");
4067 etrn_command = US"exim -R";
4068 argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R",
4072 /* If we are host-testing, don't actually do anything. */
4078 debug_printf("ETRN command is: %s\n", etrn_command);
4079 debug_printf("ETRN command execution skipped\n");
4081 if (user_msg == NULL) smtp_printf("250 OK\r\n");
4082 else smtp_user_msg(US"250", user_msg);
4087 /* If ETRN queue runs are to be serialized, check the database to
4088 ensure one isn't already running. */
4090 if (smtp_etrn_serialize && !enq_start(etrn_serialize_key))
4092 smtp_printf("458 Already processing %s\r\n", smtp_cmd_data);
4096 /* Fork a child process and run the command. We don't want to have to
4097 wait for the process at any point, so set SIGCHLD to SIG_IGN before
4098 forking. It should be set that way anyway for external incoming SMTP,
4099 but we save and restore to be tidy. If serialization is required, we
4100 actually run the command in yet another process, so we can wait for it
4101 to complete and then remove the serialization lock. */
4103 oldsignal = signal(SIGCHLD, SIG_IGN);
4105 if ((pid = fork()) == 0)
4107 smtp_input = FALSE; /* This process is not associated with the */
4108 (void)fclose(smtp_in); /* SMTP call any more. */
4109 (void)fclose(smtp_out);
4111 signal(SIGCHLD, SIG_DFL); /* Want to catch child */
4113 /* If not serializing, do the exec right away. Otherwise, fork down
4114 into another process. */
4116 if (!smtp_etrn_serialize || (pid = fork()) == 0)
4118 DEBUG(D_exec) debug_print_argv(argv);
4119 exim_nullstd(); /* Ensure std{in,out,err} exist */
4120 execv(CS argv[0], (char *const *)argv);
4121 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s",
4122 etrn_command, strerror(errno));
4123 _exit(EXIT_FAILURE); /* paranoia */
4126 /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
4127 is, we are in the first subprocess, after forking again. All we can do
4128 for a failing fork is to log it. Otherwise, wait for the 2nd process to
4129 complete, before removing the serialization. */
4132 log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN "
4133 "failed: %s", strerror(errno));
4137 DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n",
4139 (void)wait(&status);
4140 DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n",
4144 enq_end(etrn_serialize_key);
4145 _exit(EXIT_SUCCESS);
4148 /* Back in the top level SMTP process. Check that we started a subprocess
4149 and restore the signal state. */
4153 log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s",
4155 smtp_printf("458 Unable to fork process\r\n");
4156 if (smtp_etrn_serialize) enq_end(etrn_serialize_key);
4160 if (user_msg == NULL) smtp_printf("250 OK\r\n");
4161 else smtp_user_msg(US"250", user_msg);
4164 signal(SIGCHLD, oldsignal);
4169 done = synprot_error(L_smtp_syntax_error, 501, NULL,
4170 US"unexpected argument data");
4174 /* This currently happens only for NULLs, but could be extended. */
4177 done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */
4178 US"NULL character(s) present (shown as '?')");
4179 smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n");
4185 if (smtp_inend >= smtp_inbuffer + in_buffer_size)
4186 smtp_inend = smtp_inbuffer + in_buffer_size - 1;
4187 c = smtp_inend - smtp_inptr;
4188 if (c > 150) c = 150;
4190 incomplete_transaction_log(US"sync failure");
4191 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
4192 "(next input sent too soon: pipelining was%s advertised): "
4193 "rejected \"%s\" %s next input=\"%s\"",
4194 pipelining_advertised? "" : " not",
4195 smtp_cmd_buffer, host_and_ident(TRUE),
4196 string_printing(smtp_inptr));
4197 smtp_notquit_exit(US"synchronization-error", US"554",
4198 US"SMTP synchronization error");
4199 done = 1; /* Pretend eof - drops connection */
4203 case TOO_MANY_NONMAIL_CMD:
4204 s = smtp_cmd_buffer;
4205 while (*s != 0 && !isspace(*s)) s++;
4206 incomplete_transaction_log(US"too many non-mail commands");
4207 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
4208 "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE),
4209 s - smtp_cmd_buffer, smtp_cmd_buffer);
4210 smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands");
4211 done = 1; /* Pretend eof - drops connection */
4216 if (unknown_command_count++ >= smtp_max_unknown_commands)
4218 log_write(L_smtp_syntax_error, LOG_MAIN,
4219 "SMTP syntax error in \"%s\" %s %s",
4220 string_printing(smtp_cmd_buffer), host_and_ident(TRUE),
4221 US"unrecognized command");
4222 incomplete_transaction_log(US"unrecognized command");
4223 smtp_notquit_exit(US"bad-commands", US"500",
4224 US"Too many unrecognized commands");
4226 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
4227 "unrecognized commands (last was \"%s\")", host_and_ident(FALSE),
4231 done = synprot_error(L_smtp_syntax_error, 500, NULL,
4232 US"unrecognized command");
4236 /* This label is used by goto's inside loops that want to break out to
4237 the end of the command-processing loop. */
4240 last_was_rej_mail = was_rej_mail; /* Remember some last commands for */
4241 last_was_rcpt = was_rcpt; /* protocol error handling */
4245 return done - 2; /* Convert yield values */
4248 /* End of smtp_in.c */
git://git.exim.org / exim.git / blob