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) 1998-2013 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"
75 #include "internet_addressing.h"
78 #include "clientsocket.h"
79 #include "locate_host.h"
80 #include "citadel_dirs.h"
81 #include "ctdl_module.h"
83 #include "smtp_util.h"
84 enum { /* Command states for login authentication */
97 typedef void (*smtp_handler)(long offest, long Flags);
99 typedef struct _smtp_handler_hook {
104 HashList *SMTPCmds = NULL;
105 #define MaxSMTPCmdLen 10
107 #define RegisterSmtpCMD(First, H, Flags) \
108 registerSmtpCMD(HKEY(First), H, Flags)
109 void registerSmtpCMD(const char *First, long FLen,
113 smtp_handler_hook *h;
115 if (FLen >= MaxSMTPCmdLen)
116 cit_panic_backtrace (0);
118 h = (smtp_handler_hook*) malloc(sizeof(smtp_handler_hook));
119 memset(h, 0, sizeof(smtp_handler_hook));
123 Put(SMTPCmds, First, FLen, h, NULL);
126 void smtp_cleanup(void)
128 DeleteHash(&SMTPCmds);
132 * Here's where our SMTP session begins its happy day.
134 void smtp_greeting(int is_msa)
137 char message_to_spammer[1024];
139 strcpy(CC->cs_clientname, "SMTP session");
140 CC->internal_pgm = 1;
141 CC->cs_flags |= CS_STEALTH;
142 CC->session_specific_data = malloc(sizeof(citsmtp));
143 memset(SMTP, 0, sizeof(citsmtp));
145 sSMTP->is_msa = is_msa;
146 sSMTP->Cmd = NewStrBufPlain(NULL, SIZ);
147 sSMTP->helo_node = NewStrBuf();
148 sSMTP->from = NewStrBufPlain(NULL, SIZ);
149 sSMTP->recipients = NewStrBufPlain(NULL, SIZ);
150 sSMTP->OneRcpt = NewStrBufPlain(NULL, SIZ);
151 sSMTP->preferred_sender_email = NULL;
152 sSMTP->preferred_sender_name = NULL;
154 /* If this config option is set, reject connections from problem
155 * addresses immediately instead of after they execute a RCPT
157 if ( (config.c_rbl_at_greeting) && (sSMTP->is_msa == 0) ) {
158 if (rbl_check(message_to_spammer)) {
159 if (server_shutting_down)
160 cprintf("421 %s\r\n", message_to_spammer);
162 cprintf("550 %s\r\n", message_to_spammer);
163 CC->kill_me = KILLME_SPAMMER;
164 /* no need to free_recipients(valid), it's not allocated yet */
169 /* Otherwise we're either clean or we check later. */
171 if (CC->nologin==1) {
172 cprintf("451 Too many connections are already open; please try again later.\r\n");
173 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
174 /* no need to free_recipients(valid), it's not allocated yet */
178 /* Note: the FQDN *must* appear as the first thing after the 220 code.
179 * Some clients (including citmail.c) depend on it being there.
181 cprintf("220 %s ESMTP Citadel server ready.\r\n", config.c_fqdn);
186 * SMTPS is just like SMTP, except it goes crypto right away.
188 void smtps_greeting(void) {
189 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
191 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; /* kill session if no crypto */
198 * SMTP MSA port requires authentication.
200 void smtp_msa_greeting(void) {
206 * LMTP is like SMTP but with some extra bonus footage added.
208 void lmtp_greeting(void) {
216 * Generic SMTP MTA greeting
218 void smtp_mta_greeting(void) {
224 * We also have an unfiltered LMTP socket that bypasses spam filters.
226 void lmtp_unfiltered_greeting(void) {
232 sSMTP->is_unfiltered = 1;
237 * Login greeting common to all auth methods
239 void smtp_auth_greeting(long offset, long Flags) {
240 cprintf("235 Hello, %s\r\n", CC->user.fullname);
241 syslog(LOG_NOTICE, "SMTP authenticated %s\n", CC->user.fullname);
242 CC->internal_pgm = 0;
243 CC->cs_flags &= ~CS_STEALTH;
248 * Implement HELO and EHLO commands.
250 * which_command: 0=HELO, 1=EHLO, 2=LHLO
252 void smtp_hello(long offset, long which_command)
254 citsmtp *sSMTP = SMTP;
256 StrBufAppendBuf (sSMTP->helo_node, sSMTP->Cmd, offset);
258 if ( (which_command != LHLO) && (sSMTP->is_lmtp) ) {
259 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
263 if ( (which_command == LHLO) && (sSMTP->is_lmtp == 0) ) {
264 cprintf("500 LHLO is only allowed when running LMTP\r\n");
268 if (which_command == HELO) {
269 cprintf("250 Hello %s (%s [%s])\r\n",
270 ChrPtr(sSMTP->helo_node),
276 if (which_command == EHLO) {
277 cprintf("250-Hello %s (%s [%s])\r\n",
278 ChrPtr(sSMTP->helo_node),
284 cprintf("250-Greetings and joyous salutations.\r\n");
286 cprintf("250-HELP\r\n");
287 cprintf("250-SIZE %ld\r\n", config.c_maxmsglen);
291 * Offer TLS, but only if TLS is not already active.
292 * Furthermore, only offer TLS when running on
293 * the SMTP-MSA port, not on the SMTP-MTA port, due to
294 * questionable reliability of TLS in certain sending MTA's.
296 if ( (!CC->redirect_ssl) && (sSMTP->is_msa) ) {
297 cprintf("250-STARTTLS\r\n");
299 #endif /* HAVE_OPENSSL */
301 cprintf("250-AUTH LOGIN PLAIN\r\n"
302 "250-AUTH=LOGIN PLAIN\r\n"
310 * Backend function for smtp_webcit_preferences_hack().
311 * Look at a message and determine if it's the preferences file.
313 void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
314 struct CtdlMessage *msg;
315 char **webcit_conf = (char **) userdata;
318 return; // already got it
321 msg = CtdlFetchMessage(msgnum, 1);
326 if ( !CM_IsEmpty(msg, eMsgSubject) &&
327 (!strcasecmp(msg->cm_fields[eMsgSubject], "__ WebCit Preferences __")))
329 /* This is it! Change ownership of the message text so it doesn't get freed. */
330 *webcit_conf = (char *)msg->cm_fields[eMesageText];
331 msg->cm_fields[eMesageText] = NULL;
338 * The configuration item for the user's preferred display name for outgoing email is, unfortunately,
339 * stored in the account's WebCit configuration. We have to fetch it now.
341 void smtp_webcit_preferences_hack(void) {
342 char config_roomname[ROOMNAMELEN];
343 char *webcit_conf = NULL;
344 citsmtp *sSMTP = SMTP;
346 snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CC->user.usernum, USERCONFIGROOM);
347 if (CtdlGetRoom(&CC->room, config_roomname) != 0) {
352 * Find the WebCit configuration message
355 CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
361 /* Parse the webcit configuration and attempt to do something useful with it */
362 char *str = webcit_conf;
364 char *this_line = NULL;
365 while (this_line = strtok_r(str, "\n", &saveptr), this_line != NULL) {
367 if (!strncasecmp(this_line, "defaultfrom|", 12)) {
368 sSMTP->preferred_sender_email = NewStrBufPlain(&this_line[12], -1);
370 if (!strncasecmp(this_line, "defaultname|", 12)) {
371 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
373 if ((!strncasecmp(this_line, "defaultname|", 12)) && (sSMTP->preferred_sender_name == NULL)) {
374 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
384 * Implement HELP command.
386 void smtp_help(long offset, long Flags) {
387 cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
394 void smtp_get_user(long offset)
398 citsmtp *sSMTP = SMTP;
400 CtdlDecodeBase64(username, ChrPtr(sSMTP->Cmd) + offset, SIZ);
401 /* syslog(LOG_DEBUG, "Trying <%s>\n", username); */
402 if (CtdlLoginExistingUser(NULL, username) == login_ok) {
403 CtdlEncodeBase64(buf, "Password:", 9, 0);
404 cprintf("334 %s\r\n", buf);
405 sSMTP->command_state = smtp_password;
408 cprintf("500 No such user.\r\n");
409 sSMTP->command_state = smtp_command;
417 void smtp_get_pass(long offset, long Flags)
419 citsmtp *sSMTP = SMTP;
423 memset(password, 0, sizeof(password));
424 len = CtdlDecodeBase64(password, ChrPtr(sSMTP->Cmd), SIZ);
425 /* syslog(LOG_DEBUG, "Trying <%s>\n", password); */
426 if (CtdlTryPassword(password, len) == pass_ok) {
427 smtp_auth_greeting(offset, Flags);
430 cprintf("535 Authentication failed.\r\n");
432 sSMTP->command_state = smtp_command;
437 * Back end for PLAIN auth method (either inline or multistate)
439 void smtp_try_plain(long offset, long Flags)
441 citsmtp *sSMTP = SMTP;
442 const char*decoded_authstring;
443 char ident[256] = "";
449 len = StrBufDecodeBase64(sSMTP->Cmd);
452 decoded_authstring = ChrPtr(sSMTP->Cmd);
454 len = safestrncpy(ident, decoded_authstring, sizeof ident);
456 decoded_authstring += len + 1;
458 len = safestrncpy(user, decoded_authstring, sizeof user);
460 decoded_authstring += len + 1;
462 len = safestrncpy(pass, decoded_authstring, sizeof pass);
464 len = sizeof(pass) - 1;
467 sSMTP->command_state = smtp_command;
469 if (!IsEmptyStr(ident)) {
470 result = CtdlLoginExistingUser(user, ident);
473 result = CtdlLoginExistingUser(NULL, user);
476 if (result == login_ok) {
477 if (CtdlTryPassword(pass, len) == pass_ok) {
478 smtp_webcit_preferences_hack();
479 smtp_auth_greeting(offset, Flags);
483 cprintf("504 Authentication failed.\r\n");
488 * Attempt to perform authenticated SMTP
490 void smtp_auth(long offset, long Flags)
492 citsmtp *sSMTP = SMTP;
493 char username_prompt[64];
495 char encoded_authstring[1024];
498 cprintf("504 Already logged in.\r\n");
502 extract_token(method, ChrPtr(sSMTP->Cmd) + offset, 0, ' ', sizeof method);
504 if (!strncasecmp(method, "login", 5) ) {
505 if (StrLength(sSMTP->Cmd) - offset >= 7) {
509 CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
510 cprintf("334 %s\r\n", username_prompt);
511 sSMTP->command_state = smtp_user;
516 if (!strncasecmp(method, "plain", 5) ) {
518 if (num_tokens(ChrPtr(sSMTP->Cmd) + offset, ' ') < 2) {
520 SMTP->command_state = smtp_plain;
524 len = extract_token(encoded_authstring,
525 ChrPtr(sSMTP->Cmd) + offset,
527 sizeof encoded_authstring);
528 StrBufPlain(sSMTP->Cmd, encoded_authstring, len);
529 smtp_try_plain(0, Flags);
533 if (strncasecmp(method, "login", 5) ) {
534 cprintf("504 Unknown authentication method.\r\n");
542 * Implements the RSET (reset state) command.
543 * Currently this just zeroes out the state buffer. If pointers to data
544 * allocated with malloc() are ever placed in the state buffer, we have to
545 * be sure to free() them first!
547 * Set do_response to nonzero to output the SMTP RSET response code.
549 void smtp_rset(long offset, long do_response) {
550 citsmtp *sSMTP = SMTP;
553 * Our entire SMTP state is discarded when a RSET command is issued,
554 * but we need to preserve this one little piece of information, so
555 * we save it for later.
558 FlushStrBuf(sSMTP->Cmd);
559 FlushStrBuf(sSMTP->helo_node);
560 FlushStrBuf(sSMTP->from);
561 FlushStrBuf(sSMTP->recipients);
562 FlushStrBuf(sSMTP->OneRcpt);
564 sSMTP->command_state = 0;
565 sSMTP->number_of_recipients = 0;
566 sSMTP->delivery_mode = 0;
567 sSMTP->message_originated_locally = 0;
570 * we must remember is_lmtp & is_unfiltered.
574 * It is somewhat ambiguous whether we want to log out when a RSET
575 * command is issued. Here's the code to do it. It is commented out
576 * because some clients (such as Pine) issue RSET commands before
577 * each message, but still expect to be logged in.
579 * if (CC->logged_in) {
585 cprintf("250 Zap!\r\n");
590 * Clear out the portions of the state buffer that need to be cleared out
591 * after the DATA command finishes.
593 void smtp_data_clear(long offset, long flags)
595 citsmtp *sSMTP = SMTP;
597 FlushStrBuf(sSMTP->from);
598 FlushStrBuf(sSMTP->recipients);
599 FlushStrBuf(sSMTP->OneRcpt);
600 sSMTP->number_of_recipients = 0;
601 sSMTP->delivery_mode = 0;
602 sSMTP->message_originated_locally = 0;
606 * Implements the "MAIL FROM:" command
608 void smtp_mail(long offset, long flags) {
612 citsmtp *sSMTP = SMTP;
614 if (StrLength(sSMTP->from) > 0) {
615 cprintf("503 Only one sender permitted\r\n");
619 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "From:", 5)) {
620 cprintf("501 Syntax error\r\n");
624 StrBufAppendBuf(sSMTP->from, sSMTP->Cmd, offset);
625 StrBufTrim(sSMTP->from);
626 if (strchr(ChrPtr(sSMTP->from), '<') != NULL) {
627 StrBufStripAllBut(sSMTP->from, '<', '>');
630 /* We used to reject empty sender names, until it was brought to our
631 * attention that RFC1123 5.2.9 requires that this be allowed. So now
632 * we allow it, but replace the empty string with a fake
633 * address so we don't have to contend with the empty string causing
634 * other code to fail when it's expecting something there.
636 if (StrLength(sSMTP->from) == 0) {
637 StrBufPlain(sSMTP->from, HKEY("someone@example.com"));
640 /* If this SMTP connection is from a logged-in user, force the 'from'
641 * to be the user's Internet e-mail address as Citadel knows it.
644 StrBufPlain(sSMTP->from, CC->cs_inet_email, -1);
645 cprintf("250 Sender ok <%s>\r\n", ChrPtr(sSMTP->from));
646 sSMTP->message_originated_locally = 1;
650 else if (sSMTP->is_lmtp) {
651 /* Bypass forgery checking for LMTP */
654 /* Otherwise, make sure outsiders aren't trying to forge mail from
655 * this system (unless, of course, c_allow_spoofing is enabled)
657 else if (config.c_allow_spoofing == 0) {
658 process_rfc822_addr(ChrPtr(sSMTP->from), user, node, name);
659 syslog(LOG_DEBUG, "Claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
660 ChrPtr(sSMTP->from), user, node, name
662 if (CtdlHostAlias(node) != hostalias_nomatch) {
663 cprintf("550 You must log in to send mail from %s\r\n", node);
664 FlushStrBuf(sSMTP->from);
665 syslog(LOG_DEBUG, "Rejecting unauthenticated mail from %s", node);
670 cprintf("250 Sender ok\r\n");
676 * Implements the "RCPT To:" command
678 void smtp_rcpt(long offset, long flags)
680 struct CitContext *CCC = CC;
681 char message_to_spammer[SIZ];
682 recptypes *valid = NULL;
683 citsmtp *sSMTP = SMTP;
685 if (StrLength(sSMTP->from) == 0) {
686 cprintf("503 Need MAIL before RCPT\r\n");
690 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "To:", 3)) {
691 cprintf("501 Syntax error\r\n");
695 if ( (sSMTP->is_msa) && (!CCC->logged_in) ) {
696 cprintf("550 You must log in to send mail on this port.\r\n");
697 FlushStrBuf(sSMTP->from);
700 FlushStrBuf(sSMTP->OneRcpt);
701 StrBufAppendBuf(sSMTP->OneRcpt, sSMTP->Cmd, offset + 3);
702 StrBufTrim(sSMTP->OneRcpt);
703 StrBufStripAllBut(sSMTP->OneRcpt, '<', '>');
705 if ( (StrLength(sSMTP->OneRcpt) + StrLength(sSMTP->recipients)) >= SIZ) {
706 cprintf("452 Too many recipients\r\n");
711 if ( (!CCC->logged_in) /* Don't RBL authenticated users */
712 && (!sSMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
713 if (config.c_rbl_at_greeting == 0) { /* Don't RBL again if we already did it */
714 if (rbl_check(message_to_spammer)) {
715 if (server_shutting_down)
716 cprintf("421 %s\r\n", message_to_spammer);
718 cprintf("550 %s\r\n", message_to_spammer);
719 /* no need to free_recipients(valid), it's not allocated yet */
725 valid = validate_recipients(
726 ChrPtr(sSMTP->OneRcpt),
727 smtp_get_Recipients(),
728 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
730 if (valid->num_error != 0) {
731 cprintf("550 %s\r\n", valid->errormsg);
732 free_recipients(valid);
736 if (valid->num_internet > 0) {
737 if (CCC->logged_in) {
738 if (CtdlCheckInternetMailPermission(&CCC->user)==0) {
739 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
740 ChrPtr(sSMTP->OneRcpt));
741 free_recipients(valid);
747 if (valid->num_internet > 0) {
748 if ( (sSMTP->message_originated_locally == 0)
749 && (sSMTP->is_lmtp == 0) ) {
750 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(sSMTP->OneRcpt));
751 free_recipients(valid);
756 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(sSMTP->OneRcpt));
757 if (StrLength(sSMTP->recipients) > 0) {
758 StrBufAppendBufPlain(sSMTP->recipients, HKEY(","), 0);
760 StrBufAppendBuf(sSMTP->recipients, sSMTP->OneRcpt, 0);
761 sSMTP->number_of_recipients ++;
763 free_recipients(valid);
771 * Implements the DATA command
773 void smtp_data(long offset, long flags)
775 struct CitContext *CCC = CC;
778 struct CtdlMessage *msg = NULL;
784 citsmtp *sSMTP = SMTP;
786 if (StrLength(sSMTP->from) == 0) {
787 cprintf("503 Need MAIL command first.\r\n");
791 if (sSMTP->number_of_recipients < 1) {
792 cprintf("503 Need RCPT command first.\r\n");
796 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
798 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
799 defbody = NewStrBufPlain(NULL, SIZ);
801 if (defbody != NULL) {
802 if (sSMTP->is_lmtp && (CCC->cs_UDSclientUID != -1)) {
805 "Received: from %s (Citadel from userid %ld)\n"
807 ChrPtr(sSMTP->helo_node),
808 (long int) CCC->cs_UDSclientUID,
815 "Received: from %s (%s [%s])\n"
817 ChrPtr(sSMTP->helo_node),
824 body = CtdlReadMessageBodyBuf(HKEY("."), config.c_maxmsglen, defbody, 1, NULL);
825 FreeStrBuf(&defbody);
827 cprintf("550 Unable to save message: internal error.\r\n");
831 syslog(LOG_DEBUG, "Converting message...\n");
832 msg = convert_internet_message_buf(&body);
834 /* If the user is locally authenticated, FORCE the From: header to
835 * show up as the real sender. Yes, this violates the RFC standard,
836 * but IT MAKES SENSE. If you prefer strict RFC adherence over
837 * common sense, you can disable this in the configuration.
839 * We also set the "message room name" ('O' field) to MAILROOM
840 * (which is Mail> on most systems) to prevent it from getting set
841 * to something ugly like "0000058008.Sent Items>" when the message
842 * is read with a Citadel client.
844 if ( (CCC->logged_in) && (config.c_rfc822_strict_from != CFG_SMTP_FROM_NOFILTER) ) {
847 if (!CM_IsEmpty(msg, erFc822Addr) &&
848 ((config.c_rfc822_strict_from == CFG_SMTP_FROM_CORRECT) ||
849 (config.c_rfc822_strict_from == CFG_SMTP_FROM_REJECT) ) )
851 if (!IsEmptyStr(CCC->cs_inet_email))
852 validemail = strcmp(CCC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
854 (!IsEmptyStr(CCC->cs_inet_other_emails)))
856 int num_secondary_emails = 0;
858 num_secondary_emails = num_tokens(CCC->cs_inet_other_emails, '|');
859 for (i=0; i < num_secondary_emails && !validemail; ++i) {
861 extract_token(buf, CCC->cs_inet_other_emails,i,'|',sizeof CCC->cs_inet_other_emails);
862 validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
867 if (!validemail && (config.c_rfc822_strict_from == CFG_SMTP_FROM_REJECT)) {
868 syslog(LOG_ERR, "invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
869 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
873 CM_SetField(msg, eNodeName, CFG_KEY(c_nodename));
874 CM_SetField(msg, eHumanNode, CFG_KEY(c_humannode));
875 CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
876 if (sSMTP->preferred_sender_name != NULL)
877 CM_SetField(msg, eAuthor, SKEY(sSMTP->preferred_sender_name));
879 CM_SetField(msg, eAuthor, CCC->user.fullname, strlen(CCC->user.fullname));
882 if (sSMTP->preferred_sender_email != NULL)
883 CM_SetField(msg, erFc822Addr, SKEY(sSMTP->preferred_sender_email));
885 CM_SetField(msg, erFc822Addr, CCC->cs_inet_email, strlen(CCC->cs_inet_email));
889 /* Set the "envelope from" address */
890 CM_SetField(msg, eMessagePath, SKEY(sSMTP->from));
892 /* Set the "envelope to" address */
893 CM_SetField(msg, eenVelopeTo, SKEY(sSMTP->recipients));
895 /* Submit the message into the Citadel system. */
896 valid = validate_recipients(
897 ChrPtr(sSMTP->recipients),
898 smtp_get_Recipients(),
899 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
902 /* If there are modules that want to scan this message before final
903 * submission (such as virus checkers or spam filters), call them now
904 * and give them an opportunity to reject the message.
906 if (sSMTP->is_unfiltered) {
910 scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
913 if (scan_errors > 0) { /* We don't want this message! */
915 if (CM_IsEmpty(msg, eErrorMsg)) {
916 CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
919 StrBufPrintf(sSMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
922 else { /* Ok, we'll accept this message. */
923 msgnum = CtdlSubmitMsg(msg, valid, "", 0);
925 StrBufPrintf(sSMTP->OneRcpt, "250 Message accepted.\r\n");
928 StrBufPrintf(sSMTP->OneRcpt, "550 Internal delivery error\r\n");
932 /* For SMTP and ESMTP, just print the result message. For LMTP, we
933 * have to print one result message for each recipient. Since there
934 * is nothing in Citadel which would cause different recipients to
935 * have different results, we can get away with just spitting out the
936 * same message once for each recipient.
938 if (sSMTP->is_lmtp) {
939 for (i=0; i<sSMTP->number_of_recipients; ++i) {
940 cputbuf(sSMTP->OneRcpt);
944 cputbuf(sSMTP->OneRcpt);
947 /* Write something to the syslog(which may or may not be where the
948 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
950 syslog((LOG_MAIL | LOG_INFO),
951 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
954 sSMTP->number_of_recipients,
957 ChrPtr(sSMTP->OneRcpt)
962 free_recipients(valid);
963 smtp_data_clear(0, 0); /* clear out the buffers now */
968 * implements the STARTTLS command
970 void smtp_starttls(long offset, long flags)
972 char ok_response[SIZ];
973 char nosup_response[SIZ];
974 char error_response[SIZ];
976 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
977 sprintf(nosup_response, "554 TLS not supported here\r\n");
978 sprintf(error_response, "554 Internal error\r\n");
979 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
985 * Main command loop for SMTP server sessions.
987 void smtp_command_loop(void)
989 struct CitContext *CCC = CC;
990 citsmtp *sSMTP = SMTP;
991 const char *pch, *pchs;
993 char CMD[MaxSMTPCmdLen + 1];
996 syslog(LOG_EMERG, "Session SMTP data is null. WTF? We will crash now.\n");
997 return cit_panic_backtrace (0);
1000 time(&CCC->lastcmd);
1001 if (CtdlClientGetLine(sSMTP->Cmd) < 1) {
1002 syslog(LOG_CRIT, "SMTP: client disconnected: ending session.\n");
1003 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1006 syslog(LOG_DEBUG, "SMTP server: %s\n", ChrPtr(sSMTP->Cmd));
1008 if (sSMTP->command_state == smtp_user) {
1013 else if (sSMTP->command_state == smtp_password) {
1014 smtp_get_pass(0, 0);
1018 else if (sSMTP->command_state == smtp_plain) {
1019 smtp_try_plain(0, 0);
1023 pchs = pch = ChrPtr(sSMTP->Cmd);
1025 while ((*pch != '\0') &&
1027 (pch - pchs <= MaxSMTPCmdLen))
1029 CMD[i] = toupper(*pch);
1035 if ((*pch == '\0') ||
1040 if (GetHash(SMTPCmds, CMD, i, &v) &&
1043 smtp_handler_hook *h = (smtp_handler_hook*) v;
1045 if (isblank(pchs[i]))
1053 cprintf("502 I'm afraid I can't do that.\r\n");
1056 void smtp_noop(long offest, long Flags)
1058 cprintf("250 NOOP\r\n");
1061 void smtp_quit(long offest, long Flags)
1063 cprintf("221 Goodbye...\r\n");
1064 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1067 /*****************************************************************************/
1068 /* MODULE INITIALIZATION STUFF */
1069 /*****************************************************************************/
1071 * This cleanup function blows away the temporary memory used by
1074 void smtp_cleanup_function(void)
1076 citsmtp *sSMTP = SMTP;
1078 /* Don't do this stuff if this is not an SMTP session! */
1079 if (CC->h_command_function != smtp_command_loop) return;
1081 syslog(LOG_DEBUG, "Performing SMTP cleanup hook\n");
1083 FreeStrBuf(&sSMTP->Cmd);
1084 FreeStrBuf(&sSMTP->helo_node);
1085 FreeStrBuf(&sSMTP->from);
1086 FreeStrBuf(&sSMTP->recipients);
1087 FreeStrBuf(&sSMTP->OneRcpt);
1088 FreeStrBuf(&sSMTP->preferred_sender_email);
1089 FreeStrBuf(&sSMTP->preferred_sender_name);
1094 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1095 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1096 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1097 const char *CitadelServiceSMTP_LMTP="LMTP";
1098 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1100 CTDL_MODULE_INIT(smtp)
1104 SMTPCmds = NewHash(1, NULL);
1106 RegisterSmtpCMD("AUTH", smtp_auth, 0);
1107 RegisterSmtpCMD("DATA", smtp_data, 0);
1108 RegisterSmtpCMD("HELO", smtp_hello, HELO);
1109 RegisterSmtpCMD("EHLO", smtp_hello, EHLO);
1110 RegisterSmtpCMD("LHLO", smtp_hello, LHLO);
1111 RegisterSmtpCMD("HELP", smtp_help, 0);
1112 RegisterSmtpCMD("MAIL", smtp_mail, 0);
1113 RegisterSmtpCMD("NOOP", smtp_noop, 0);
1114 RegisterSmtpCMD("QUIT", smtp_quit, 0);
1115 RegisterSmtpCMD("RCPT", smtp_rcpt, 0);
1116 RegisterSmtpCMD("RSET", smtp_rset, 1);
1118 RegisterSmtpCMD("STARTTLS", smtp_starttls, 0);
1122 CtdlRegisterServiceHook(config.c_smtp_port, /* SMTP MTA */
1127 CitadelServiceSMTP_MTA);
1130 CtdlRegisterServiceHook(config.c_smtps_port,
1135 CitadelServiceSMTPS_MTA);
1138 CtdlRegisterServiceHook(config.c_msa_port, /* SMTP MSA */
1143 CitadelServiceSMTP_MSA);
1145 CtdlRegisterServiceHook(0, /* local LMTP */
1150 CitadelServiceSMTP_LMTP);
1152 CtdlRegisterServiceHook(0, /* local LMTP */
1153 file_lmtp_unfiltered_socket,
1154 lmtp_unfiltered_greeting,
1157 CitadelServiceSMTP_LMTP_UNF);
1159 CtdlRegisterCleanupHook(smtp_cleanup);
1160 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1163 /* return our module name for the log */