2 * This module is an SMTP and ESMTP server for the Citadel system.
3 * It is compliant with all of the following:
5 * RFC 821 - Simple Mail Transfer Protocol
6 * RFC 876 - Survey of SMTP Implementations
7 * RFC 1047 - Duplicate messages and SMTP
8 * RFC 1652 - 8 bit MIME
9 * RFC 1869 - Extended Simple Mail Transfer Protocol
10 * RFC 1870 - SMTP Service Extension for Message Size Declaration
11 * RFC 2033 - Local Mail Transfer Protocol
12 * RFC 2197 - SMTP Service Extension for Command Pipelining
13 * RFC 2476 - Message Submission
14 * RFC 2487 - SMTP Service Extension for Secure SMTP over TLS
15 * RFC 2554 - SMTP Service Extension for Authentication
16 * RFC 2821 - Simple Mail Transfer Protocol
17 * RFC 2822 - Internet Message Format
18 * RFC 2920 - SMTP Service Extension for Command Pipelining
20 * The VRFY and EXPN commands have been removed from this implementation
21 * because nobody uses these commands anymore, except for spammers.
23 * Copyright (c) 1998-2012 by the citadel.org team
25 * This program is open source software; you can redistribute it and/or modify
26 * it under the terms of the GNU General Public License version 3.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
43 #include <sys/types.h>
46 #if TIME_WITH_SYS_TIME
47 # include <sys/time.h>
51 # include <sys/time.h>
61 #include <sys/socket.h>
62 #include <netinet/in.h>
63 #include <arpa/inet.h>
64 #include <libcitadel.h>
67 #include "citserver.h"
74 #include "internet_addressing.h"
77 #include "clientsocket.h"
78 #include "locate_host.h"
79 #include "citadel_dirs.h"
80 #include "ctdl_module.h"
82 #include "smtp_util.h"
83 enum { /* Command states for login authentication */
96 typedef void (*smtp_handler)(long offest, long Flags);
98 typedef struct _smtp_handler_hook {
103 HashList *SMTPCmds = NULL;
104 #define MaxSMTPCmdLen 10
106 #define RegisterSmtpCMD(First, H, Flags) \
107 registerSmtpCMD(HKEY(First), H, Flags)
108 void registerSmtpCMD(const char *First, long FLen,
112 smtp_handler_hook *h;
114 if (FLen >= MaxSMTPCmdLen)
115 cit_panic_backtrace (0);
117 h = (smtp_handler_hook*) malloc(sizeof(smtp_handler_hook));
118 memset(h, 0, sizeof(smtp_handler_hook));
122 Put(SMTPCmds, First, FLen, h, NULL);
125 void smtp_cleanup(void)
127 DeleteHash(&SMTPCmds);
131 * Here's where our SMTP session begins its happy day.
133 void smtp_greeting(int is_msa)
136 char message_to_spammer[1024];
138 strcpy(CC->cs_clientname, "SMTP session");
139 CC->internal_pgm = 1;
140 CC->cs_flags |= CS_STEALTH;
141 CC->session_specific_data = malloc(sizeof(citsmtp));
142 memset(SMTP, 0, sizeof(citsmtp));
144 sSMTP->is_msa = is_msa;
145 sSMTP->Cmd = NewStrBufPlain(NULL, SIZ);
146 sSMTP->helo_node = NewStrBuf();
147 sSMTP->from = NewStrBufPlain(NULL, SIZ);
148 sSMTP->recipients = NewStrBufPlain(NULL, SIZ);
149 sSMTP->OneRcpt = NewStrBufPlain(NULL, SIZ);
151 /* If this config option is set, reject connections from problem
152 * addresses immediately instead of after they execute a RCPT
154 if ( (config.c_rbl_at_greeting) && (sSMTP->is_msa == 0) ) {
155 if (rbl_check(message_to_spammer)) {
156 if (server_shutting_down)
157 cprintf("421 %s\r\n", message_to_spammer);
159 cprintf("550 %s\r\n", message_to_spammer);
160 CC->kill_me = KILLME_SPAMMER;
161 /* no need to free_recipients(valid), it's not allocated yet */
166 /* Otherwise we're either clean or we check later. */
168 if (CC->nologin==1) {
169 cprintf("451 Too many connections are already open; please try again later.\r\n");
170 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
171 /* no need to free_recipients(valid), it's not allocated yet */
175 /* Note: the FQDN *must* appear as the first thing after the 220 code.
176 * Some clients (including citmail.c) depend on it being there.
178 cprintf("220 %s ESMTP Citadel server ready.\r\n", config.c_fqdn);
183 * SMTPS is just like SMTP, except it goes crypto right away.
185 void smtps_greeting(void) {
186 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
188 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; /* kill session if no crypto */
195 * SMTP MSA port requires authentication.
197 void smtp_msa_greeting(void) {
203 * LMTP is like SMTP but with some extra bonus footage added.
205 void lmtp_greeting(void) {
213 * Generic SMTP MTA greeting
215 void smtp_mta_greeting(void) {
221 * We also have an unfiltered LMTP socket that bypasses spam filters.
223 void lmtp_unfiltered_greeting(void) {
229 sSMTP->is_unfiltered = 1;
234 * Login greeting common to all auth methods
236 void smtp_auth_greeting(long offset, long Flags) {
237 cprintf("235 Hello, %s\r\n", CC->user.fullname);
238 syslog(LOG_NOTICE, "SMTP authenticated %s\n", CC->user.fullname);
239 CC->internal_pgm = 0;
240 CC->cs_flags &= ~CS_STEALTH;
245 * Implement HELO and EHLO commands.
247 * which_command: 0=HELO, 1=EHLO, 2=LHLO
249 void smtp_hello(long offset, long which_command)
251 citsmtp *sSMTP = SMTP;
253 StrBufAppendBuf (sSMTP->helo_node, sSMTP->Cmd, offset);
255 if ( (which_command != LHLO) && (sSMTP->is_lmtp) ) {
256 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
260 if ( (which_command == LHLO) && (sSMTP->is_lmtp == 0) ) {
261 cprintf("500 LHLO is only allowed when running LMTP\r\n");
265 if (which_command == HELO) {
266 cprintf("250 Hello %s (%s [%s])\r\n",
267 ChrPtr(sSMTP->helo_node),
273 if (which_command == EHLO) {
274 cprintf("250-Hello %s (%s [%s])\r\n",
275 ChrPtr(sSMTP->helo_node),
281 cprintf("250-Greetings and joyous salutations.\r\n");
283 cprintf("250-HELP\r\n");
284 cprintf("250-SIZE %ld\r\n", config.c_maxmsglen);
288 * Offer TLS, but only if TLS is not already active.
289 * Furthermore, only offer TLS when running on
290 * the SMTP-MSA port, not on the SMTP-MTA port, due to
291 * questionable reliability of TLS in certain sending MTA's.
293 if ( (!CC->redirect_ssl) && (sSMTP->is_msa) ) {
294 cprintf("250-STARTTLS\r\n");
296 #endif /* HAVE_OPENSSL */
298 cprintf("250-AUTH LOGIN PLAIN\r\n"
299 "250-AUTH=LOGIN PLAIN\r\n"
307 * Backend function for smtp_webcit_preferences_hack().
308 * Look at a message and determine if it's the preferences file.
310 void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
311 struct CtdlMessage *msg;
312 char **webcit_conf = (char **) userdata;
315 return; // already got it
318 msg = CtdlFetchMessage(msgnum, 1);
323 if ( (msg->cm_fields['U']) && (!strcasecmp(msg->cm_fields['U'], "__ WebCit Preferences __")) ) {
324 /* This is it! Change ownership of the message text so it doesn't get freed. */
325 *webcit_conf = (char *)msg->cm_fields['M'];
326 msg->cm_fields['M'] = NULL;
328 CtdlFreeMessage(msg);
333 * The configuration item for the user's preferred display name for outgoing email is, unfortunately,
334 * stored in the account's WebCit configuration. We have to fetch it now.
336 void smtp_webcit_preferences_hack(void) {
337 char config_roomname[ROOMNAMELEN];
338 char *webcit_conf = NULL;
340 snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CC->user.usernum, USERCONFIGROOM);
341 if (CtdlGetRoom(&CC->room, config_roomname) != 0) {
346 * Find the WebCit configuration message
349 CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
355 /* FIXME : now do something with this data */
364 * Implement HELP command.
366 void smtp_help(long offset, long Flags) {
367 cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
374 void smtp_get_user(long offset)
378 citsmtp *sSMTP = SMTP;
380 CtdlDecodeBase64(username, ChrPtr(sSMTP->Cmd) + offset, SIZ);
381 /* syslog(LOG_DEBUG, "Trying <%s>\n", username); */
382 if (CtdlLoginExistingUser(NULL, username) == login_ok) {
383 CtdlEncodeBase64(buf, "Password:", 9, 0);
384 cprintf("334 %s\r\n", buf);
385 sSMTP->command_state = smtp_password;
388 cprintf("500 No such user.\r\n");
389 sSMTP->command_state = smtp_command;
397 void smtp_get_pass(long offset, long Flags)
399 citsmtp *sSMTP = SMTP;
403 memset(password, 0, sizeof(password));
404 len = CtdlDecodeBase64(password, ChrPtr(sSMTP->Cmd), SIZ);
405 /* syslog(LOG_DEBUG, "Trying <%s>\n", password); */
406 if (CtdlTryPassword(password, len) == pass_ok) {
407 smtp_auth_greeting(offset, Flags);
410 cprintf("535 Authentication failed.\r\n");
412 sSMTP->command_state = smtp_command;
417 * Back end for PLAIN auth method (either inline or multistate)
419 void smtp_try_plain(long offset, long Flags)
421 citsmtp *sSMTP = SMTP;
422 char decoded_authstring[1024];
429 CtdlDecodeBase64(decoded_authstring, ChrPtr(sSMTP->Cmd), StrLength(sSMTP->Cmd));
430 safestrncpy(ident, decoded_authstring, sizeof ident);
431 safestrncpy(user, &decoded_authstring[strlen(ident) + 1], sizeof user);
432 len = safestrncpy(pass, &decoded_authstring[strlen(ident) + strlen(user) + 2], sizeof pass);
434 len = sizeof(pass) - 1;
436 sSMTP->command_state = smtp_command;
438 if (!IsEmptyStr(ident)) {
439 result = CtdlLoginExistingUser(user, ident);
442 result = CtdlLoginExistingUser(NULL, user);
445 if (result == login_ok) {
446 if (CtdlTryPassword(pass, len) == pass_ok) {
447 //// smtp_webcit_preferences_hack();
448 smtp_auth_greeting(offset, Flags);
452 cprintf("504 Authentication failed.\r\n");
457 * Attempt to perform authenticated SMTP
459 void smtp_auth(long offset, long Flags)
461 citsmtp *sSMTP = SMTP;
462 char username_prompt[64];
464 char encoded_authstring[1024];
467 cprintf("504 Already logged in.\r\n");
471 extract_token(method, ChrPtr(sSMTP->Cmd) + offset, 0, ' ', sizeof method);
473 if (!strncasecmp(method, "login", 5) ) {
474 if (StrLength(sSMTP->Cmd) - offset >= 7) {
478 CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
479 cprintf("334 %s\r\n", username_prompt);
480 sSMTP->command_state = smtp_user;
485 if (!strncasecmp(method, "plain", 5) ) {
487 if (num_tokens(ChrPtr(sSMTP->Cmd) + offset, ' ') < 2) {
489 SMTP->command_state = smtp_plain;
493 len = extract_token(encoded_authstring,
494 ChrPtr(sSMTP->Cmd) + offset,
496 sizeof encoded_authstring);
497 StrBufPlain(sSMTP->Cmd, encoded_authstring, len);
498 smtp_try_plain(0, Flags);
502 if (strncasecmp(method, "login", 5) ) {
503 cprintf("504 Unknown authentication method.\r\n");
511 * Implements the RSET (reset state) command.
512 * Currently this just zeroes out the state buffer. If pointers to data
513 * allocated with malloc() are ever placed in the state buffer, we have to
514 * be sure to free() them first!
516 * Set do_response to nonzero to output the SMTP RSET response code.
518 void smtp_rset(long offset, long do_response) {
519 citsmtp *sSMTP = SMTP;
522 * Our entire SMTP state is discarded when a RSET command is issued,
523 * but we need to preserve this one little piece of information, so
524 * we save it for later.
527 FlushStrBuf(sSMTP->Cmd);
528 FlushStrBuf(sSMTP->helo_node);
529 FlushStrBuf(sSMTP->from);
530 FlushStrBuf(sSMTP->recipients);
531 FlushStrBuf(sSMTP->OneRcpt);
533 sSMTP->command_state = 0;
534 sSMTP->number_of_recipients = 0;
535 sSMTP->delivery_mode = 0;
536 sSMTP->message_originated_locally = 0;
539 * we must remember is_lmtp & is_unfiltered.
543 * It is somewhat ambiguous whether we want to log out when a RSET
544 * command is issued. Here's the code to do it. It is commented out
545 * because some clients (such as Pine) issue RSET commands before
546 * each message, but still expect to be logged in.
548 * if (CC->logged_in) {
554 cprintf("250 Zap!\r\n");
559 * Clear out the portions of the state buffer that need to be cleared out
560 * after the DATA command finishes.
562 void smtp_data_clear(long offset, long flags)
564 citsmtp *sSMTP = SMTP;
566 FlushStrBuf(sSMTP->from);
567 FlushStrBuf(sSMTP->recipients);
568 FlushStrBuf(sSMTP->OneRcpt);
569 sSMTP->number_of_recipients = 0;
570 sSMTP->delivery_mode = 0;
571 sSMTP->message_originated_locally = 0;
575 * Implements the "MAIL FROM:" command
577 void smtp_mail(long offset, long flags) {
581 citsmtp *sSMTP = SMTP;
583 if (StrLength(sSMTP->from) > 0) {
584 cprintf("503 Only one sender permitted\r\n");
588 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "From:", 5)) {
589 cprintf("501 Syntax error\r\n");
593 StrBufAppendBuf(sSMTP->from, sSMTP->Cmd, offset);
594 StrBufTrim(sSMTP->from);
595 if (strchr(ChrPtr(sSMTP->from), '<') != NULL) {
596 StrBufStripAllBut(sSMTP->from, '<', '>');
599 /* We used to reject empty sender names, until it was brought to our
600 * attention that RFC1123 5.2.9 requires that this be allowed. So now
601 * we allow it, but replace the empty string with a fake
602 * address so we don't have to contend with the empty string causing
603 * other code to fail when it's expecting something there.
605 if (StrLength(sSMTP->from)) {
606 StrBufPlain(sSMTP->from, HKEY("someone@example.com"));
609 /* If this SMTP connection is from a logged-in user, force the 'from'
610 * to be the user's Internet e-mail address as Citadel knows it.
613 StrBufPlain(sSMTP->from, CC->cs_inet_email, -1);
614 cprintf("250 Sender ok <%s>\r\n", ChrPtr(sSMTP->from));
615 sSMTP->message_originated_locally = 1;
619 else if (sSMTP->is_lmtp) {
620 /* Bypass forgery checking for LMTP */
623 /* Otherwise, make sure outsiders aren't trying to forge mail from
624 * this system (unless, of course, c_allow_spoofing is enabled)
626 else if (config.c_allow_spoofing == 0) {
627 process_rfc822_addr(ChrPtr(sSMTP->from), user, node, name);
628 syslog(LOG_DEBUG, "Claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
629 ChrPtr(sSMTP->from), user, node, name
631 if (CtdlHostAlias(node) != hostalias_nomatch) {
632 cprintf("550 You must log in to send mail from %s\r\n", node);
633 FlushStrBuf(sSMTP->from);
634 syslog(LOG_DEBUG, "Rejecting unauthenticated mail from %s", node);
639 cprintf("250 Sender ok\r\n");
645 * Implements the "RCPT To:" command
647 void smtp_rcpt(long offset, long flags)
649 struct CitContext *CCC = CC;
650 char message_to_spammer[SIZ];
651 struct recptypes *valid = NULL;
652 citsmtp *sSMTP = SMTP;
654 if (StrLength(sSMTP->from) == 0) {
655 cprintf("503 Need MAIL before RCPT\r\n");
659 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "To:", 3)) {
660 cprintf("501 Syntax error\r\n");
664 if ( (sSMTP->is_msa) && (!CCC->logged_in) ) {
665 cprintf("550 You must log in to send mail on this port.\r\n");
666 FlushStrBuf(sSMTP->from);
669 FlushStrBuf(sSMTP->OneRcpt);
670 StrBufAppendBuf(sSMTP->OneRcpt, sSMTP->Cmd, offset + 3);
671 StrBufTrim(sSMTP->OneRcpt);
672 StrBufStripAllBut(sSMTP->OneRcpt, '<', '>');
674 if ( (StrLength(sSMTP->OneRcpt) + StrLength(sSMTP->recipients)) >= SIZ) {
675 cprintf("452 Too many recipients\r\n");
680 if ( (!CCC->logged_in) /* Don't RBL authenticated users */
681 && (!sSMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
682 if (config.c_rbl_at_greeting == 0) { /* Don't RBL again if we already did it */
683 if (rbl_check(message_to_spammer)) {
684 if (server_shutting_down)
685 cprintf("421 %s\r\n", message_to_spammer);
687 cprintf("550 %s\r\n", message_to_spammer);
688 /* no need to free_recipients(valid), it's not allocated yet */
694 valid = validate_recipients(
695 ChrPtr(sSMTP->OneRcpt),
696 smtp_get_Recipients(),
697 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
699 if (valid->num_error != 0) {
700 cprintf("550 %s\r\n", valid->errormsg);
701 free_recipients(valid);
705 if (valid->num_internet > 0) {
706 if (CCC->logged_in) {
707 if (CtdlCheckInternetMailPermission(&CCC->user)==0) {
708 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
709 ChrPtr(sSMTP->OneRcpt));
710 free_recipients(valid);
716 if (valid->num_internet > 0) {
717 if ( (sSMTP->message_originated_locally == 0)
718 && (sSMTP->is_lmtp == 0) ) {
719 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(sSMTP->OneRcpt));
720 free_recipients(valid);
725 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(sSMTP->OneRcpt));
726 if (StrLength(sSMTP->recipients) > 0) {
727 StrBufAppendBufPlain(sSMTP->recipients, HKEY(","), 0);
729 StrBufAppendBuf(sSMTP->recipients, sSMTP->OneRcpt, 0);
730 sSMTP->number_of_recipients ++;
732 free_recipients(valid);
740 * Implements the DATA command
742 void smtp_data(long offset, long flags)
744 struct CitContext *CCC = CC;
747 struct CtdlMessage *msg = NULL;
750 struct recptypes *valid;
753 citsmtp *sSMTP = SMTP;
755 if (StrLength(sSMTP->from) == 0) {
756 cprintf("503 Need MAIL command first.\r\n");
760 if (sSMTP->number_of_recipients < 1) {
761 cprintf("503 Need RCPT command first.\r\n");
765 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
767 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
768 defbody = NewStrBufPlain(NULL, SIZ);
770 if (defbody != NULL) {
771 if (sSMTP->is_lmtp && (CCC->cs_UDSclientUID != -1)) {
774 "Received: from %s (Citadel from userid %ld)\n"
776 ChrPtr(sSMTP->helo_node),
777 (long int) CCC->cs_UDSclientUID,
784 "Received: from %s (%s [%s])\n"
786 ChrPtr(sSMTP->helo_node),
793 body = CtdlReadMessageBodyBuf(HKEY("."), config.c_maxmsglen, defbody, 1, NULL);
794 FreeStrBuf(&defbody);
796 cprintf("550 Unable to save message: internal error.\r\n");
800 syslog(LOG_DEBUG, "Converting message...\n");
801 msg = convert_internet_message_buf(&body);
803 /* If the user is locally authenticated, FORCE the From: header to
804 * show up as the real sender. Yes, this violates the RFC standard,
805 * but IT MAKES SENSE. If you prefer strict RFC adherence over
806 * common sense, you can disable this in the configuration.
808 * We also set the "message room name" ('O' field) to MAILROOM
809 * (which is Mail> on most systems) to prevent it from getting set
810 * to something ugly like "0000058008.Sent Items>" when the message
811 * is read with a Citadel client.
813 if ( (CCC->logged_in) && (config.c_rfc822_strict_from != CFG_SMTP_FROM_NOFILTER) ) {
816 if (!IsEmptyStr(msg->cm_fields['F']) &&
817 ((config.c_rfc822_strict_from == CFG_SMTP_FROM_CORRECT) ||
818 (config.c_rfc822_strict_from == CFG_SMTP_FROM_REJECT) ) )
820 if (!IsEmptyStr(CCC->cs_inet_email))
821 validemail = strcmp(CCC->cs_inet_email, msg->cm_fields['F']) == 0;
823 (!IsEmptyStr(CCC->cs_inet_other_emails)))
825 int num_secondary_emails = 0;
827 num_secondary_emails = num_tokens(CCC->cs_inet_other_emails, '|');
828 for (i=0; i < num_secondary_emails && !validemail; ++i) {
830 extract_token(buf, CCC->cs_inet_other_emails,i,'|',sizeof CCC->cs_inet_other_emails);
831 validemail = strcmp(buf, msg->cm_fields['F']) == 0;
836 if (!validemail && (config.c_rfc822_strict_from == CFG_SMTP_FROM_REJECT)) {
837 syslog(LOG_ERR, "invalid sender '%s' - rejecting this message", msg->cm_fields['F']);
838 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields['F']);
842 if (msg->cm_fields['A'] != NULL) free(msg->cm_fields['A']);
843 if (msg->cm_fields['N'] != NULL) free(msg->cm_fields['N']);
844 if (msg->cm_fields['H'] != NULL) free(msg->cm_fields['H']);
845 if (msg->cm_fields['O'] != NULL) free(msg->cm_fields['O']);
846 msg->cm_fields['A'] = strdup(CCC->user.fullname);
847 msg->cm_fields['N'] = strdup(config.c_nodename);
848 msg->cm_fields['H'] = strdup(config.c_humannode);
849 msg->cm_fields['O'] = strdup(MAILROOM);
852 if (msg->cm_fields['F'] != NULL) free(msg->cm_fields['F']);
853 msg->cm_fields['F'] = strdup(CCC->cs_inet_email);
857 /* Set the "envelope from" address */
858 if (msg->cm_fields['P'] != NULL) {
859 free(msg->cm_fields['P']);
861 msg->cm_fields['P'] = strdup(ChrPtr(sSMTP->from));
863 /* Set the "envelope to" address */
864 if (msg->cm_fields['V'] != NULL) {
865 free(msg->cm_fields['V']);
867 msg->cm_fields['V'] = strdup(ChrPtr(sSMTP->recipients));
869 /* Submit the message into the Citadel system. */
870 valid = validate_recipients(
871 ChrPtr(sSMTP->recipients),
872 smtp_get_Recipients(),
873 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
876 /* If there are modules that want to scan this message before final
877 * submission (such as virus checkers or spam filters), call them now
878 * and give them an opportunity to reject the message.
880 if (sSMTP->is_unfiltered) {
884 scan_errors = PerformMessageHooks(msg, EVT_SMTPSCAN);
887 if (scan_errors > 0) { /* We don't want this message! */
889 if (msg->cm_fields['0'] == NULL) {
890 msg->cm_fields['0'] = strdup("Message rejected by filter");
893 StrBufPrintf(sSMTP->OneRcpt, "550 %s\r\n", msg->cm_fields['0']);
896 else { /* Ok, we'll accept this message. */
897 msgnum = CtdlSubmitMsg(msg, valid, "", 0);
899 StrBufPrintf(sSMTP->OneRcpt, "250 Message accepted.\r\n");
902 StrBufPrintf(sSMTP->OneRcpt, "550 Internal delivery error\r\n");
906 /* For SMTP and ESMTP, just print the result message. For LMTP, we
907 * have to print one result message for each recipient. Since there
908 * is nothing in Citadel which would cause different recipients to
909 * have different results, we can get away with just spitting out the
910 * same message once for each recipient.
912 if (sSMTP->is_lmtp) {
913 for (i=0; i<sSMTP->number_of_recipients; ++i) {
914 cputbuf(sSMTP->OneRcpt);
918 cputbuf(sSMTP->OneRcpt);
921 /* Write something to the syslog(which may or may not be where the
922 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
924 syslog((LOG_MAIL | LOG_INFO),
925 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
928 sSMTP->number_of_recipients,
931 ChrPtr(sSMTP->OneRcpt)
935 CtdlFreeMessage(msg);
936 free_recipients(valid);
937 smtp_data_clear(0, 0); /* clear out the buffers now */
942 * implements the STARTTLS command
944 void smtp_starttls(long offset, long flags)
946 char ok_response[SIZ];
947 char nosup_response[SIZ];
948 char error_response[SIZ];
950 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
951 sprintf(nosup_response, "554 TLS not supported here\r\n");
952 sprintf(error_response, "554 Internal error\r\n");
953 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
959 * Main command loop for SMTP server sessions.
961 void smtp_command_loop(void)
963 struct CitContext *CCC = CC;
964 citsmtp *sSMTP = SMTP;
965 const char *pch, *pchs;
967 char CMD[MaxSMTPCmdLen + 1];
970 syslog(LOG_EMERG, "Session SMTP data is null. WTF? We will crash now.\n");
971 return cit_panic_backtrace (0);
975 if (CtdlClientGetLine(sSMTP->Cmd) < 1) {
976 syslog(LOG_CRIT, "SMTP: client disconnected: ending session.\n");
977 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
980 syslog(LOG_DEBUG, "SMTP server: %s\n", ChrPtr(sSMTP->Cmd));
982 if (sSMTP->command_state == smtp_user) {
986 else if (sSMTP->command_state == smtp_password) {
990 else if (sSMTP->command_state == smtp_plain) {
991 smtp_try_plain(0, 0);
994 pchs = pch = ChrPtr(sSMTP->Cmd);
996 while ((*pch != '\0') &&
998 (pch - pchs <= MaxSMTPCmdLen))
1000 CMD[i] = toupper(*pch);
1006 if ((*pch == '\0') ||
1011 if (GetHash(SMTPCmds, CMD, i, &v) &&
1014 smtp_handler_hook *h = (smtp_handler_hook*) v;
1016 if (isblank(pchs[i]))
1024 cprintf("502 I'm afraid I can't do that.\r\n");
1027 void smtp_noop(long offest, long Flags)
1029 cprintf("250 NOOP\r\n");
1032 void smtp_quit(long offest, long Flags)
1034 cprintf("221 Goodbye...\r\n");
1035 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1038 /*****************************************************************************/
1039 /* MODULE INITIALIZATION STUFF */
1040 /*****************************************************************************/
1042 * This cleanup function blows away the temporary memory used by
1045 void smtp_cleanup_function(void)
1047 citsmtp *sSMTP = SMTP;
1049 /* Don't do this stuff if this is not an SMTP session! */
1050 if (CC->h_command_function != smtp_command_loop) return;
1052 syslog(LOG_DEBUG, "Performing SMTP cleanup hook\n");
1054 FreeStrBuf(&sSMTP->Cmd);
1055 FreeStrBuf(&sSMTP->helo_node);
1056 FreeStrBuf(&sSMTP->from);
1057 FreeStrBuf(&sSMTP->recipients);
1058 FreeStrBuf(&sSMTP->OneRcpt);
1063 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1064 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1065 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1066 const char *CitadelServiceSMTP_LMTP="LMTP";
1067 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1069 CTDL_MODULE_INIT(smtp)
1073 SMTPCmds = NewHash(1, NULL);
1075 RegisterSmtpCMD("AUTH", smtp_auth, 0);
1076 RegisterSmtpCMD("DATA", smtp_data, 0);
1077 RegisterSmtpCMD("HELO", smtp_hello, HELO);
1078 RegisterSmtpCMD("EHLO", smtp_hello, EHLO);
1079 RegisterSmtpCMD("LHLO", smtp_hello, LHLO);
1080 RegisterSmtpCMD("HELP", smtp_help, 0);
1081 RegisterSmtpCMD("MAIL", smtp_mail, 0);
1082 RegisterSmtpCMD("NOOP", smtp_noop, 0);
1083 RegisterSmtpCMD("QUIT", smtp_quit, 0);
1084 RegisterSmtpCMD("RCPT", smtp_rcpt, 0);
1085 RegisterSmtpCMD("RSET", smtp_rset, 1);
1087 RegisterSmtpCMD("STARTTLS", smtp_starttls, 0);
1091 CtdlRegisterServiceHook(config.c_smtp_port, /* SMTP MTA */
1096 CitadelServiceSMTP_MTA);
1099 CtdlRegisterServiceHook(config.c_smtps_port,
1104 CitadelServiceSMTPS_MTA);
1107 CtdlRegisterServiceHook(config.c_msa_port, /* SMTP MSA */
1112 CitadelServiceSMTP_MSA);
1114 CtdlRegisterServiceHook(0, /* local LMTP */
1119 CitadelServiceSMTP_LMTP);
1121 CtdlRegisterServiceHook(0, /* local LMTP */
1122 file_lmtp_unfiltered_socket,
1123 lmtp_unfiltered_greeting,
1126 CitadelServiceSMTP_LMTP_UNF);
1128 CtdlRegisterCleanupHook(smtp_cleanup);
1129 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1132 /* return our module name for the log */