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) 1998-2021 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>
50 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <arpa/inet.h>
53 #include <libcitadel.h>
56 #include "citserver.h"
64 #include "internet_addressing.h"
67 #include "clientsocket.h"
68 #include "locate_host.h"
69 #include "citadel_dirs.h"
70 #include "ctdl_module.h"
72 #include "smtp_util.h"
74 enum { /* Command states for login authentication */
89 * Here's where our SMTP session begins its happy day.
91 void smtp_greeting(int is_msa) {
92 char message_to_spammer[1024];
94 strcpy(CC->cs_clientname, "SMTP session");
96 CC->cs_flags |= CS_STEALTH;
97 CC->session_specific_data = malloc(sizeof(struct citsmtp));
98 memset(SMTP, 0, sizeof(struct citsmtp));
99 SMTP->is_msa = is_msa;
100 SMTP->Cmd = NewStrBufPlain(NULL, SIZ);
101 SMTP->helo_node = NewStrBuf();
102 SMTP->from = NewStrBufPlain(NULL, SIZ);
103 SMTP->recipients = NewStrBufPlain(NULL, SIZ);
104 SMTP->OneRcpt = NewStrBufPlain(NULL, SIZ);
105 SMTP->preferred_sender_email = NULL;
106 SMTP->preferred_sender_name = NULL;
108 /* If this config option is set, reject connections from problem
109 * addresses immediately instead of after they execute a RCPT
111 if ( (CtdlGetConfigInt("c_rbl_at_greeting")) && (SMTP->is_msa == 0) ) {
112 if (rbl_check(CC->cs_addr, message_to_spammer)) {
113 if (server_shutting_down)
114 cprintf("421 %s\r\n", message_to_spammer);
116 cprintf("550 %s\r\n", message_to_spammer);
117 CC->kill_me = KILLME_SPAMMER;
118 /* no need to free_recipients(valid), it's not allocated yet */
123 /* Otherwise we're either clean or we check later. */
125 if (CC->nologin==1) {
126 cprintf("451 Too many connections are already open; please try again later.\r\n");
127 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
128 /* no need to free_recipients(valid), it's not allocated yet */
132 /* Note: the FQDN *must* appear as the first thing after the 220 code.
133 * Some clients (including citmail.c) depend on it being there.
135 cprintf("220 %s ESMTP Citadel server ready.\r\n", CtdlGetConfigStr("c_fqdn"));
140 * SMTPS is just like SMTP, except it goes crypto right away.
142 void smtps_greeting(void) {
143 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
145 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; /* kill session if no crypto */
152 * SMTP MSA port requires authentication.
154 void smtp_msa_greeting(void) {
160 * LMTP is like SMTP but with some extra bonus footage added.
162 void lmtp_greeting(void) {
170 * Generic SMTP MTA greeting
172 void smtp_mta_greeting(void) {
178 * We also have an unfiltered LMTP socket that bypasses spam filters.
180 void lmtp_unfiltered_greeting(void) {
183 SMTP->is_unfiltered = 1;
188 * Login greeting common to all auth methods
190 void smtp_auth_greeting(void) {
191 cprintf("235 Hello, %s\r\n", CC->user.fullname);
192 syslog(LOG_INFO, "serv_smtp: SMTP authenticated %s", CC->user.fullname);
193 CC->internal_pgm = 0;
194 CC->cs_flags &= ~CS_STEALTH;
199 * Implement HELO and EHLO commands.
201 * which_command: 0=HELO, 1=EHLO, 2=LHLO
203 void smtp_hello(int which_command) {
205 if (StrLength(SMTP->Cmd) >= 6) {
206 StrBufAppendBuf(SMTP->helo_node, SMTP->Cmd, 5);
209 if ( (which_command != LHLO) && (SMTP->is_lmtp) ) {
210 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
214 if ( (which_command == LHLO) && (SMTP->is_lmtp == 0) ) {
215 cprintf("500 LHLO is only allowed when running LMTP\r\n");
219 if (which_command == HELO) {
220 cprintf("250 Hello %s (%s [%s])\r\n",
221 ChrPtr(SMTP->helo_node),
227 if (which_command == EHLO) {
228 cprintf("250-Hello %s (%s [%s])\r\n",
229 ChrPtr(SMTP->helo_node),
235 cprintf("250-Greetings and joyous salutations.\r\n");
237 cprintf("250-HELP\r\n");
238 cprintf("250-SIZE %ld\r\n", CtdlGetConfigLong("c_maxmsglen"));
242 * Offer TLS, but only if TLS is not already active.
243 * Furthermore, only offer TLS when running on
244 * the SMTP-MSA port, not on the SMTP-MTA port, due to
245 * questionable reliability of TLS in certain sending MTA's.
247 if ( (!CC->redirect_ssl) && (SMTP->is_msa) ) {
248 cprintf("250-STARTTLS\r\n");
250 #endif /* HAVE_OPENSSL */
252 cprintf("250-AUTH LOGIN PLAIN\r\n"
253 "250-AUTH=LOGIN PLAIN\r\n"
261 * Backend function for smtp_webcit_preferences_hack().
262 * Look at a message and determine if it's the preferences file.
264 void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
265 struct CtdlMessage *msg;
266 char **webcit_conf = (char **) userdata;
269 return; // already got it
272 msg = CtdlFetchMessage(msgnum, 1);
277 if ( !CM_IsEmpty(msg, eMsgSubject) && (!strcasecmp(msg->cm_fields[eMsgSubject], "__ WebCit Preferences __"))) {
278 /* This is it! Change ownership of the message text so it doesn't get freed. */
279 *webcit_conf = (char *)msg->cm_fields[eMesageText];
280 msg->cm_fields[eMesageText] = NULL;
287 * The configuration item for the user's preferred display name for outgoing email is, unfortunately,
288 * stored in the account's WebCit configuration. We have to fetch it now.
290 void smtp_webcit_preferences_hack(void) {
291 char config_roomname[ROOMNAMELEN];
292 char *webcit_conf = NULL;
294 snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CC->user.usernum, USERCONFIGROOM);
295 if (CtdlGetRoom(&CC->room, config_roomname) != 0) {
300 * Find the WebCit configuration message
303 CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
309 /* Parse the webcit configuration and attempt to do something useful with it */
310 char *str = webcit_conf;
312 char *this_line = NULL;
313 while (this_line = strtok_r(str, "\n", &saveptr), this_line != NULL) {
315 if (!strncasecmp(this_line, "defaultfrom|", 12)) {
316 SMTP->preferred_sender_email = NewStrBufPlain(&this_line[12], -1);
318 if (!strncasecmp(this_line, "defaultname|", 12)) {
319 SMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
321 if ((!strncasecmp(this_line, "defaultname|", 12)) && (SMTP->preferred_sender_name == NULL)) {
322 SMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
331 * Implement HELP command.
333 void smtp_help(void) {
334 cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
341 void smtp_get_user(int offset) {
344 StrBuf *UserName = NewStrBufDup(SMTP->Cmd);
345 StrBufCutLeft(UserName, offset);
346 StrBufDecodeBase64(UserName);
348 if (CtdlLoginExistingUser(ChrPtr(UserName)) == login_ok) {
349 size_t len = CtdlEncodeBase64(buf, "Password:", 9, 0);
351 if (buf[len - 1] == '\n') {
354 cprintf("334 %s\r\n", buf);
355 SMTP->command_state = smtp_password;
358 cprintf("500 No such user.\r\n");
359 SMTP->command_state = smtp_command;
361 FreeStrBuf(&UserName);
368 void smtp_get_pass(void)
372 memset(password, 0, sizeof(password));
373 StrBufDecodeBase64(SMTP->Cmd);
374 syslog(LOG_DEBUG, "serv_smtp: trying <%s>", password);
375 if (CtdlTryPassword(SKEY(SMTP->Cmd)) == pass_ok) {
376 smtp_auth_greeting();
379 cprintf("535 Authentication failed.\r\n");
381 SMTP->command_state = smtp_command;
386 * Back end for PLAIN auth method (either inline or multistate)
388 void smtp_try_plain(void) {
389 const char*decoded_authstring;
390 char ident[256] = "";
399 memset(pass, 0, sizeof(pass));
400 decoded_len = StrBufDecodeBase64(SMTP->Cmd);
402 if (decoded_len > 0) {
403 decoded_authstring = ChrPtr(SMTP->Cmd);
405 len = safestrncpy(ident, decoded_authstring, sizeof ident);
407 decoded_len -= len - 1;
408 decoded_authstring += len + 1;
410 if (decoded_len > 0) {
411 len = safestrncpy(user, decoded_authstring, sizeof user);
413 decoded_authstring += len + 1;
414 decoded_len -= len - 1;
417 if (decoded_len > 0) {
418 plen = safestrncpy(pass, decoded_authstring, sizeof pass);
421 plen = sizeof(pass) - 1;
425 SMTP->command_state = smtp_command;
427 if (!IsEmptyStr(ident)) {
428 result = CtdlLoginExistingUser(ident);
431 result = CtdlLoginExistingUser(user);
434 if (result == login_ok) {
435 if (CtdlTryPassword(pass, plen) == pass_ok) {
436 smtp_webcit_preferences_hack();
437 smtp_auth_greeting();
441 cprintf("504 Authentication failed.\r\n");
446 * Attempt to perform authenticated SMTP
448 void smtp_auth(void) {
449 char username_prompt[64];
451 char encoded_authstring[1024];
454 cprintf("504 Already logged in.\r\n");
458 if (StrLength(SMTP->Cmd) < 6) {
459 cprintf("501 Syntax error\r\n");
463 extract_token(method, ChrPtr(SMTP->Cmd) + 5, 0, ' ', sizeof method);
465 if (!strncasecmp(method, "login", 5) ) {
466 if (StrLength(SMTP->Cmd) >= 12) {
467 syslog(LOG_DEBUG, "serv_smtp: username <%s> supplied inline", ChrPtr(SMTP->Cmd)+11);
471 size_t len = CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
472 if (username_prompt[len - 1] == '\n') {
473 username_prompt[len - 1] = '\0';
475 cprintf("334 %s\r\n", username_prompt);
476 SMTP->command_state = smtp_user;
481 if (!strncasecmp(method, "plain", 5) ) {
483 if (num_tokens(ChrPtr(SMTP->Cmd) + 5, ' ') < 2) {
485 SMTP->command_state = smtp_plain;
489 len = extract_token(encoded_authstring,
490 ChrPtr(SMTP->Cmd) + 5,
492 sizeof encoded_authstring);
493 StrBufPlain(SMTP->Cmd, encoded_authstring, len);
498 cprintf("504 Unknown authentication method.\r\n");
504 * Implements the RSET (reset state) command.
505 * Currently this just zeroes out the state buffer. If pointers to data
506 * allocated with malloc() are ever placed in the state buffer, we have to
507 * be sure to free() them first!
509 * Set do_response to nonzero to output the SMTP RSET response code.
511 void smtp_rset(int do_response) {
513 * Our entire SMTP state is discarded when a RSET command is issued,
514 * but we need to preserve this one little piece of information, so
515 * we save it for later.
518 FlushStrBuf(SMTP->Cmd);
519 FlushStrBuf(SMTP->helo_node);
520 FlushStrBuf(SMTP->from);
521 FlushStrBuf(SMTP->recipients);
522 FlushStrBuf(SMTP->OneRcpt);
524 SMTP->command_state = 0;
525 SMTP->number_of_recipients = 0;
526 SMTP->delivery_mode = 0;
527 SMTP->message_originated_locally = 0;
530 * we must remember is_lmtp & is_unfiltered.
534 * It is somewhat ambiguous whether we want to log out when a RSET
535 * command is issued. Here's the code to do it. It is commented out
536 * because some clients (such as Pine) issue RSET commands before
537 * each message, but still expect to be logged in.
539 * if (CC->logged_in) {
545 cprintf("250 Zap!\r\n");
551 * Clear out the portions of the state buffer that need to be cleared out
552 * after the DATA command finishes.
554 void smtp_data_clear(void) {
555 FlushStrBuf(SMTP->from);
556 FlushStrBuf(SMTP->recipients);
557 FlushStrBuf(SMTP->OneRcpt);
558 SMTP->number_of_recipients = 0;
559 SMTP->delivery_mode = 0;
560 SMTP->message_originated_locally = 0;
565 * Implements the "MAIL FROM:" command
567 void smtp_mail(void) {
572 if (StrLength(SMTP->from) > 0) {
573 cprintf("503 Only one sender permitted\r\n");
577 if (StrLength(SMTP->Cmd) < 6) {
578 cprintf("501 Syntax error\r\n");
582 if (strncasecmp(ChrPtr(SMTP->Cmd) + 5, "From:", 5)) {
583 cprintf("501 Syntax error\r\n");
587 StrBufAppendBuf(SMTP->from, SMTP->Cmd, 5);
588 StrBufTrim(SMTP->from);
589 if (strchr(ChrPtr(SMTP->from), '<') != NULL) {
590 StrBufStripAllBut(SMTP->from, '<', '>');
593 /* We used to reject empty sender names, until it was brought to our
594 * attention that RFC1123 5.2.9 requires that this be allowed. So now
595 * we allow it, but replace the empty string with a fake
596 * address so we don't have to contend with the empty string causing
597 * other code to fail when it's expecting something there.
599 if (StrLength(SMTP->from) == 0) {
600 StrBufPlain(SMTP->from, HKEY("someone@example.com"));
603 /* If this SMTP connection is from a logged-in user, force the 'from'
604 * to be the user's Internet e-mail address as Citadel knows it.
607 StrBufPlain(SMTP->from, CC->cs_inet_email, -1);
608 cprintf("250 Sender ok <%s>\r\n", ChrPtr(SMTP->from));
609 SMTP->message_originated_locally = 1;
613 else if (SMTP->is_lmtp) {
614 /* Bypass forgery checking for LMTP */
617 /* Otherwise, make sure outsiders aren't trying to forge mail from
618 * this system (unless, of course, c_allow_spoofing is enabled)
620 else if (CtdlGetConfigInt("c_allow_spoofing") == 0) {
621 process_rfc822_addr(ChrPtr(SMTP->from), user, node, name);
622 syslog(LOG_DEBUG, "serv_smtp: claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
623 ChrPtr(SMTP->from), user, node, name
625 if (CtdlHostAlias(node) != hostalias_nomatch) {
626 cprintf("550 You must log in to send mail from %s\r\n", node);
627 FlushStrBuf(SMTP->from);
628 syslog(LOG_DEBUG, "serv_smtp: rejecting unauthenticated mail from %s", node);
633 cprintf("250 Sender ok\r\n");
638 * Implements the "RCPT To:" command
640 void smtp_rcpt(void) {
641 char message_to_spammer[SIZ];
642 struct recptypes *valid = NULL;
644 if (StrLength(SMTP->from) == 0) {
645 cprintf("503 Need MAIL before RCPT\r\n");
649 if (StrLength(SMTP->Cmd) < 6) {
650 cprintf("501 Syntax error\r\n");
654 if (strncasecmp(ChrPtr(SMTP->Cmd) + 5, "To:", 3)) {
655 cprintf("501 Syntax error\r\n");
659 if ( (SMTP->is_msa) && (!CC->logged_in) ) {
660 cprintf("550 You must log in to send mail on this port.\r\n");
661 FlushStrBuf(SMTP->from);
665 FlushStrBuf(SMTP->OneRcpt);
666 StrBufAppendBuf(SMTP->OneRcpt, SMTP->Cmd, 8);
667 StrBufTrim(SMTP->OneRcpt);
668 StrBufStripAllBut(SMTP->OneRcpt, '<', '>');
670 if ( (StrLength(SMTP->OneRcpt) + StrLength(SMTP->recipients)) >= SIZ) {
671 cprintf("452 Too many recipients\r\n");
676 if ( (!CC->logged_in) /* Don't RBL authenticated users */
677 && (!SMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
678 if (CtdlGetConfigInt("c_rbl_at_greeting") == 0) { /* Don't RBL again if we already did it */
679 if (rbl_check(CC->cs_addr, message_to_spammer)) {
680 if (server_shutting_down)
681 cprintf("421 %s\r\n", message_to_spammer);
683 cprintf("550 %s\r\n", message_to_spammer);
684 /* no need to free_recipients(valid), it's not allocated yet */
690 valid = validate_recipients(
691 ChrPtr(SMTP->OneRcpt),
692 smtp_get_Recipients(),
693 (SMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
695 if (valid->num_error != 0) {
696 cprintf("550 %s\r\n", valid->errormsg);
697 free_recipients(valid);
701 if (valid->num_internet > 0) {
703 if (CtdlCheckInternetMailPermission(&CC->user)==0) {
704 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
705 ChrPtr(SMTP->OneRcpt));
706 free_recipients(valid);
712 if (valid->num_internet > 0) {
713 if ( (SMTP->message_originated_locally == 0)
714 && (SMTP->is_lmtp == 0) ) {
715 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(SMTP->OneRcpt));
716 free_recipients(valid);
721 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(SMTP->OneRcpt));
722 if (StrLength(SMTP->recipients) > 0) {
723 StrBufAppendBufPlain(SMTP->recipients, HKEY(","), 0);
725 StrBufAppendBuf(SMTP->recipients, SMTP->OneRcpt, 0);
726 SMTP->number_of_recipients ++;
728 free_recipients(valid);
734 * Implements the DATA command
736 void smtp_data(void) {
739 struct CtdlMessage *msg = NULL;
742 struct recptypes *valid;
746 if (StrLength(SMTP->from) == 0) {
747 cprintf("503 Need MAIL command first.\r\n");
751 if (SMTP->number_of_recipients < 1) {
752 cprintf("503 Need RCPT command first.\r\n");
756 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
758 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
759 defbody = NewStrBufPlain(NULL, SIZ);
761 if (defbody != NULL) {
762 if (SMTP->is_lmtp && (CC->cs_UDSclientUID != -1)) {
765 "Received: from %s (Citadel from userid %ld)\n"
767 ChrPtr(SMTP->helo_node),
768 (long int) CC->cs_UDSclientUID,
769 CtdlGetConfigStr("c_fqdn"),
775 "Received: from %s (%s [%s])\n"
777 ChrPtr(SMTP->helo_node),
780 CtdlGetConfigStr("c_fqdn"),
784 body = CtdlReadMessageBodyBuf(HKEY("."), CtdlGetConfigLong("c_maxmsglen"), defbody, 1);
785 FreeStrBuf(&defbody);
787 cprintf("550 Unable to save message: internal error.\r\n");
791 syslog(LOG_DEBUG, "serv_smtp: converting message...");
792 msg = convert_internet_message_buf(&body);
794 /* If the user is locally authenticated, FORCE the From: header to
795 * show up as the real sender. Yes, this violates the RFC standard,
796 * but IT MAKES SENSE. If you prefer strict RFC adherence over
797 * common sense, you can disable this in the configuration.
799 * We also set the "message room name" ('O' field) to MAILROOM
800 * (which is Mail> on most systems) to prevent it from getting set
801 * to something ugly like "0000058008.Sent Items>" when the message
802 * is read with a Citadel client.
804 if ( (CC->logged_in) && (CtdlGetConfigInt("c_rfc822_strict_from") != CFG_SMTP_FROM_NOFILTER) ) {
807 if (!CM_IsEmpty(msg, erFc822Addr) &&
808 ((CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_CORRECT) ||
809 (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT) ) )
811 if (!IsEmptyStr(CC->cs_inet_email))
812 validemail = strcmp(CC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
814 (!IsEmptyStr(CC->cs_inet_other_emails)))
816 int num_secondary_emails = 0;
818 num_secondary_emails = num_tokens(CC->cs_inet_other_emails, '|');
819 for (i=0; i < num_secondary_emails && !validemail; ++i) {
821 extract_token(buf, CC->cs_inet_other_emails,i,'|',sizeof CC->cs_inet_other_emails);
822 validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
827 if (!validemail && (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT)) {
828 syslog(LOG_ERR, "serv_smtp: invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
829 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
833 CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
834 if (SMTP->preferred_sender_name != NULL)
835 CM_SetField(msg, eAuthor, SKEY(SMTP->preferred_sender_name));
837 CM_SetField(msg, eAuthor, CC->user.fullname, strlen(CC->user.fullname));
840 if (SMTP->preferred_sender_email != NULL) {
841 CM_SetField(msg, erFc822Addr, SKEY(SMTP->preferred_sender_email));
844 CM_SetField(msg, erFc822Addr, CC->cs_inet_email, strlen(CC->cs_inet_email));
849 /* Set the "envelope from" address */
850 CM_SetField(msg, eMessagePath, SKEY(SMTP->from));
852 /* Set the "envelope to" address */
853 CM_SetField(msg, eenVelopeTo, SKEY(SMTP->recipients));
855 /* Submit the message into the Citadel system. */
856 valid = validate_recipients(
857 ChrPtr(SMTP->recipients),
858 smtp_get_Recipients(),
859 (SMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
862 /* If there are modules that want to scan this message before final
863 * submission (such as virus checkers or spam filters), call them now
864 * and give them an opportunity to reject the message.
866 if (SMTP->is_unfiltered) {
870 scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
873 if (scan_errors > 0) { /* We don't want this message! */
875 if (CM_IsEmpty(msg, eErrorMsg)) {
876 CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
879 StrBufPrintf(SMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
882 else { /* Ok, we'll accept this message. */
883 msgnum = CtdlSubmitMsg(msg, valid, "");
885 StrBufPrintf(SMTP->OneRcpt, "250 Message accepted.\r\n");
888 StrBufPrintf(SMTP->OneRcpt, "550 Internal delivery error\r\n");
892 /* For SMTP and ESMTP, just print the result message. For LMTP, we
893 * have to print one result message for each recipient. Since there
894 * is nothing in Citadel which would cause different recipients to
895 * have different results, we can get away with just spitting out the
896 * same message once for each recipient.
899 for (i=0; i<SMTP->number_of_recipients; ++i) {
900 cputbuf(SMTP->OneRcpt);
904 cputbuf(SMTP->OneRcpt);
907 /* Write something to the syslog(which may or may not be where the
908 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
910 syslog((LOG_MAIL | LOG_INFO),
911 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
914 SMTP->number_of_recipients,
917 ChrPtr(SMTP->OneRcpt)
922 free_recipients(valid);
923 smtp_data_clear(); /* clear out the buffers now */
928 * Implements the STARTTLS command
930 void smtp_starttls(void) {
931 char ok_response[SIZ];
932 char nosup_response[SIZ];
933 char error_response[SIZ];
935 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
936 sprintf(nosup_response, "554 TLS not supported here\r\n");
937 sprintf(error_response, "554 Internal error\r\n");
938 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
944 * Implements the NOOP (NO OPeration) command
946 void smtp_noop(void) {
947 cprintf("250 NOOP\r\n");
952 * Implements the QUIT command
954 void smtp_quit(void) {
955 cprintf("221 Goodbye...\r\n");
956 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
961 * Main command loop for SMTP server sessions.
963 void smtp_command_loop(void) {
964 static const ConstStr AuthPlainStr = {HKEY("AUTH PLAIN")};
967 syslog(LOG_ERR, "serv_smtp: Session SMTP data is null. WTF? We will crash now.");
972 if (CtdlClientGetLine(SMTP->Cmd) < 1) {
973 syslog(LOG_INFO, "SMTP: client disconnected: ending session.");
974 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
978 if (SMTP->command_state == smtp_user) {
979 if (!strncmp(ChrPtr(SMTP->Cmd), AuthPlainStr.Key, AuthPlainStr.len)) {
988 else if (SMTP->command_state == smtp_password) {
993 else if (SMTP->command_state == smtp_plain) {
998 syslog(LOG_DEBUG, "serv_smtp: client sent command <%s>", ChrPtr(SMTP->Cmd));
1000 if (!strncasecmp(ChrPtr(SMTP->Cmd), "NOOP", 4)) {
1005 if (!strncasecmp(ChrPtr(SMTP->Cmd), "QUIT", 4)) {
1010 if (!strncasecmp(ChrPtr(SMTP->Cmd), "HELO", 4)) {
1015 if (!strncasecmp(ChrPtr(SMTP->Cmd), "EHLO", 4)) {
1020 if (!strncasecmp(ChrPtr(SMTP->Cmd), "LHLO", 4)) {
1025 if (!strncasecmp(ChrPtr(SMTP->Cmd), "RSET", 4)) {
1030 if (!strncasecmp(ChrPtr(SMTP->Cmd), "AUTH", 4)) {
1035 if (!strncasecmp(ChrPtr(SMTP->Cmd), "DATA", 4)) {
1040 if (!strncasecmp(ChrPtr(SMTP->Cmd), "HELP", 4)) {
1045 if (!strncasecmp(ChrPtr(SMTP->Cmd), "MAIL", 4)) {
1050 if (!strncasecmp(ChrPtr(SMTP->Cmd), "RCPT", 4)) {
1055 if (!strncasecmp(ChrPtr(SMTP->Cmd), "STARTTLS", 8)) {
1061 cprintf("502 I'm afraid I can't do that.\r\n");
1065 /*****************************************************************************/
1066 /* MODULE INITIALIZATION STUFF */
1067 /*****************************************************************************/
1069 * This cleanup function blows away the temporary memory used by
1072 void smtp_cleanup_function(void)
1074 /* Don't do this stuff if this is not an SMTP session! */
1075 if (CC->h_command_function != smtp_command_loop) return;
1077 syslog(LOG_DEBUG, "Performing SMTP cleanup hook");
1079 FreeStrBuf(&SMTP->Cmd);
1080 FreeStrBuf(&SMTP->helo_node);
1081 FreeStrBuf(&SMTP->from);
1082 FreeStrBuf(&SMTP->recipients);
1083 FreeStrBuf(&SMTP->OneRcpt);
1084 FreeStrBuf(&SMTP->preferred_sender_email);
1085 FreeStrBuf(&SMTP->preferred_sender_name);
1090 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1091 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1092 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1093 const char *CitadelServiceSMTP_LMTP="LMTP";
1094 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1097 CTDL_MODULE_INIT(smtp)
1100 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtp_port"), /* SMTP MTA */
1105 CitadelServiceSMTP_MTA);
1108 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtps_port"), /* SMTPS MTA */
1113 CitadelServiceSMTPS_MTA);
1116 CtdlRegisterServiceHook(CtdlGetConfigInt("c_msa_port"), /* SMTP MSA */
1121 CitadelServiceSMTP_MSA);
1123 CtdlRegisterServiceHook(0, /* local LMTP */
1128 CitadelServiceSMTP_LMTP);
1130 CtdlRegisterServiceHook(0, /* local LMTP */
1131 file_lmtp_unfiltered_socket,
1132 lmtp_unfiltered_greeting,
1135 CitadelServiceSMTP_LMTP_UNF);
1137 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1140 /* return our module name for the log */