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 */
87 typedef void (*smtp_handler)(long offest, long Flags);
89 typedef struct _smtp_handler_hook {
94 int EnableSMTPLog = 0;
96 HashList *SMTPCmds = NULL;
97 #define MaxSMTPCmdLen 10
99 #define RegisterSmtpCMD(First, H, Flags) \
100 registerSmtpCMD(HKEY(First), H, Flags)
101 void registerSmtpCMD(const char *First, long FLen,
105 smtp_handler_hook *h;
107 if (FLen >= MaxSMTPCmdLen)
112 h = (smtp_handler_hook*) malloc(sizeof(smtp_handler_hook));
113 memset(h, 0, sizeof(smtp_handler_hook));
117 Put(SMTPCmds, First, FLen, h, NULL);
122 * Here's where our SMTP session begins its happy day.
124 void smtp_greeting(int is_msa)
127 char message_to_spammer[1024];
129 strcpy(CC->cs_clientname, "SMTP session");
130 CC->internal_pgm = 1;
131 CC->cs_flags |= CS_STEALTH;
132 CC->session_specific_data = malloc(sizeof(citsmtp));
133 memset(SMTP, 0, sizeof(citsmtp));
135 sSMTP->is_msa = is_msa;
136 sSMTP->Cmd = NewStrBufPlain(NULL, SIZ);
137 sSMTP->helo_node = NewStrBuf();
138 sSMTP->from = NewStrBufPlain(NULL, SIZ);
139 sSMTP->recipients = NewStrBufPlain(NULL, SIZ);
140 sSMTP->OneRcpt = NewStrBufPlain(NULL, SIZ);
141 sSMTP->preferred_sender_email = NULL;
142 sSMTP->preferred_sender_name = NULL;
144 /* If this config option is set, reject connections from problem
145 * addresses immediately instead of after they execute a RCPT
147 if ( (CtdlGetConfigInt("c_rbl_at_greeting")) && (sSMTP->is_msa == 0) ) {
148 if (rbl_check(CC->cs_addr, message_to_spammer)) {
149 if (server_shutting_down)
150 cprintf("421 %s\r\n", message_to_spammer);
152 cprintf("550 %s\r\n", message_to_spammer);
153 CC->kill_me = KILLME_SPAMMER;
154 /* no need to free_recipients(valid), it's not allocated yet */
159 /* Otherwise we're either clean or we check later. */
161 if (CC->nologin==1) {
162 cprintf("451 Too many connections are already open; please try again later.\r\n");
163 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
164 /* no need to free_recipients(valid), it's not allocated yet */
168 /* Note: the FQDN *must* appear as the first thing after the 220 code.
169 * Some clients (including citmail.c) depend on it being there.
171 cprintf("220 %s ESMTP Citadel server ready.\r\n", CtdlGetConfigStr("c_fqdn"));
176 * SMTPS is just like SMTP, except it goes crypto right away.
178 void smtps_greeting(void) {
179 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
181 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; /* kill session if no crypto */
188 * SMTP MSA port requires authentication.
190 void smtp_msa_greeting(void) {
196 * LMTP is like SMTP but with some extra bonus footage added.
198 void lmtp_greeting(void) {
206 * Generic SMTP MTA greeting
208 void smtp_mta_greeting(void) {
214 * We also have an unfiltered LMTP socket that bypasses spam filters.
216 void lmtp_unfiltered_greeting(void) {
222 sSMTP->is_unfiltered = 1;
227 * Login greeting common to all auth methods
229 void smtp_auth_greeting(long offset, long Flags) {
230 cprintf("235 Hello, %s\r\n", CC->user.fullname);
231 syslog(LOG_INFO, "serv_smtp: SMTP authenticated %s", CC->user.fullname);
232 CC->internal_pgm = 0;
233 CC->cs_flags &= ~CS_STEALTH;
238 * Implement HELO and EHLO commands.
240 * which_command: 0=HELO, 1=EHLO, 2=LHLO
242 void smtp_hello(long offset, long which_command)
244 citsmtp *sSMTP = SMTP;
246 StrBufAppendBuf (sSMTP->helo_node, sSMTP->Cmd, offset);
248 if ( (which_command != LHLO) && (sSMTP->is_lmtp) ) {
249 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
253 if ( (which_command == LHLO) && (sSMTP->is_lmtp == 0) ) {
254 cprintf("500 LHLO is only allowed when running LMTP\r\n");
258 if (which_command == HELO) {
259 cprintf("250 Hello %s (%s [%s])\r\n",
260 ChrPtr(sSMTP->helo_node),
266 if (which_command == EHLO) {
267 cprintf("250-Hello %s (%s [%s])\r\n",
268 ChrPtr(sSMTP->helo_node),
274 cprintf("250-Greetings and joyous salutations.\r\n");
276 cprintf("250-HELP\r\n");
277 cprintf("250-SIZE %ld\r\n", CtdlGetConfigLong("c_maxmsglen"));
281 * Offer TLS, but only if TLS is not already active.
282 * Furthermore, only offer TLS when running on
283 * the SMTP-MSA port, not on the SMTP-MTA port, due to
284 * questionable reliability of TLS in certain sending MTA's.
286 if ( (!CC->redirect_ssl) && (sSMTP->is_msa) ) {
287 cprintf("250-STARTTLS\r\n");
289 #endif /* HAVE_OPENSSL */
291 cprintf("250-AUTH LOGIN PLAIN\r\n"
292 "250-AUTH=LOGIN PLAIN\r\n"
300 * Backend function for smtp_webcit_preferences_hack().
301 * Look at a message and determine if it's the preferences file.
303 void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
304 struct CtdlMessage *msg;
305 char **webcit_conf = (char **) userdata;
308 return; // already got it
311 msg = CtdlFetchMessage(msgnum, 1);
316 if ( !CM_IsEmpty(msg, eMsgSubject) &&
317 (!strcasecmp(msg->cm_fields[eMsgSubject], "__ WebCit Preferences __")))
319 /* This is it! Change ownership of the message text so it doesn't get freed. */
320 *webcit_conf = (char *)msg->cm_fields[eMesageText];
321 msg->cm_fields[eMesageText] = NULL;
328 * The configuration item for the user's preferred display name for outgoing email is, unfortunately,
329 * stored in the account's WebCit configuration. We have to fetch it now.
331 void smtp_webcit_preferences_hack(void) {
332 char config_roomname[ROOMNAMELEN];
333 char *webcit_conf = NULL;
334 citsmtp *sSMTP = SMTP;
336 snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CC->user.usernum, USERCONFIGROOM);
337 if (CtdlGetRoom(&CC->room, config_roomname) != 0) {
342 * Find the WebCit configuration message
345 CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
351 /* Parse the webcit configuration and attempt to do something useful with it */
352 char *str = webcit_conf;
354 char *this_line = NULL;
355 while (this_line = strtok_r(str, "\n", &saveptr), this_line != NULL) {
357 if (!strncasecmp(this_line, "defaultfrom|", 12)) {
358 sSMTP->preferred_sender_email = NewStrBufPlain(&this_line[12], -1);
360 if (!strncasecmp(this_line, "defaultname|", 12)) {
361 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
363 if ((!strncasecmp(this_line, "defaultname|", 12)) && (sSMTP->preferred_sender_name == NULL)) {
364 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
374 * Implement HELP command.
376 void smtp_help(long offset, long Flags) {
377 cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
384 void smtp_get_user(long offset)
387 citsmtp *sSMTP = SMTP;
389 StrBufDecodeBase64(sSMTP->Cmd);
391 if (CtdlLoginExistingUser(ChrPtr(sSMTP->Cmd)) == login_ok) {
392 size_t len = CtdlEncodeBase64(buf, "Password:", 9, 0);
394 if (buf[len - 1] == '\n') {
397 cprintf("334 %s\r\n", buf);
398 sSMTP->command_state = smtp_password;
401 cprintf("500 No such user.\r\n");
402 sSMTP->command_state = smtp_command;
410 void smtp_get_pass(long offset, long Flags)
412 citsmtp *sSMTP = SMTP;
415 memset(password, 0, sizeof(password));
416 StrBufDecodeBase64(sSMTP->Cmd);
417 syslog(LOG_DEBUG, "serv_smtp: trying <%s>", password);
418 if (CtdlTryPassword(SKEY(sSMTP->Cmd)) == pass_ok) {
419 smtp_auth_greeting(offset, Flags);
422 cprintf("535 Authentication failed.\r\n");
424 sSMTP->command_state = smtp_command;
429 * Back end for PLAIN auth method (either inline or multistate)
431 void smtp_try_plain(long offset, long Flags)
433 citsmtp *sSMTP = SMTP;
434 const char*decoded_authstring;
435 char ident[256] = "";
444 memset(pass, 0, sizeof(pass));
445 decoded_len = StrBufDecodeBase64(sSMTP->Cmd);
449 decoded_authstring = ChrPtr(sSMTP->Cmd);
451 len = safestrncpy(ident, decoded_authstring, sizeof ident);
453 decoded_len -= len - 1;
454 decoded_authstring += len + 1;
458 len = safestrncpy(user, decoded_authstring, sizeof user);
460 decoded_authstring += len + 1;
461 decoded_len -= len - 1;
466 plen = safestrncpy(pass, decoded_authstring, sizeof pass);
469 plen = sizeof(pass) - 1;
473 sSMTP->command_state = smtp_command;
475 if (!IsEmptyStr(ident)) {
476 result = CtdlLoginExistingUser(ident);
479 result = CtdlLoginExistingUser(user);
482 if (result == login_ok) {
483 if (CtdlTryPassword(pass, plen) == pass_ok) {
484 smtp_webcit_preferences_hack();
485 smtp_auth_greeting(offset, Flags);
489 cprintf("504 Authentication failed.\r\n");
494 * Attempt to perform authenticated SMTP
496 void smtp_auth(long offset, long Flags)
498 citsmtp *sSMTP = SMTP;
499 char username_prompt[64];
501 char encoded_authstring[1024];
504 cprintf("504 Already logged in.\r\n");
508 extract_token(method, ChrPtr(sSMTP->Cmd) + offset, 0, ' ', sizeof method);
510 if (!strncasecmp(method, "login", 5) ) {
511 if (StrLength(sSMTP->Cmd) - offset >= 7) {
515 size_t len = CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
516 if (username_prompt[len - 1] == '\n') {
517 username_prompt[len - 1] = '\0';
519 cprintf("334 %s\r\n", username_prompt);
520 sSMTP->command_state = smtp_user;
525 if (!strncasecmp(method, "plain", 5) ) {
527 if (num_tokens(ChrPtr(sSMTP->Cmd) + offset, ' ') < 2) {
529 SMTP->command_state = smtp_plain;
533 len = extract_token(encoded_authstring,
534 ChrPtr(sSMTP->Cmd) + offset,
536 sizeof encoded_authstring);
537 StrBufPlain(sSMTP->Cmd, encoded_authstring, len);
538 smtp_try_plain(0, Flags);
542 if (strncasecmp(method, "login", 5) ) {
543 cprintf("504 Unknown authentication method.\r\n");
551 * Implements the RSET (reset state) command.
552 * Currently this just zeroes out the state buffer. If pointers to data
553 * allocated with malloc() are ever placed in the state buffer, we have to
554 * be sure to free() them first!
556 * Set do_response to nonzero to output the SMTP RSET response code.
558 void smtp_rset(long offset, long do_response) {
559 citsmtp *sSMTP = SMTP;
562 * Our entire SMTP state is discarded when a RSET command is issued,
563 * but we need to preserve this one little piece of information, so
564 * we save it for later.
567 FlushStrBuf(sSMTP->Cmd);
568 FlushStrBuf(sSMTP->helo_node);
569 FlushStrBuf(sSMTP->from);
570 FlushStrBuf(sSMTP->recipients);
571 FlushStrBuf(sSMTP->OneRcpt);
573 sSMTP->command_state = 0;
574 sSMTP->number_of_recipients = 0;
575 sSMTP->delivery_mode = 0;
576 sSMTP->message_originated_locally = 0;
579 * we must remember is_lmtp & is_unfiltered.
583 * It is somewhat ambiguous whether we want to log out when a RSET
584 * command is issued. Here's the code to do it. It is commented out
585 * because some clients (such as Pine) issue RSET commands before
586 * each message, but still expect to be logged in.
588 * if (CC->logged_in) {
594 cprintf("250 Zap!\r\n");
599 * Clear out the portions of the state buffer that need to be cleared out
600 * after the DATA command finishes.
602 void smtp_data_clear(long offset, long flags)
604 citsmtp *sSMTP = SMTP;
606 FlushStrBuf(sSMTP->from);
607 FlushStrBuf(sSMTP->recipients);
608 FlushStrBuf(sSMTP->OneRcpt);
609 sSMTP->number_of_recipients = 0;
610 sSMTP->delivery_mode = 0;
611 sSMTP->message_originated_locally = 0;
615 * Implements the "MAIL FROM:" command
617 void smtp_mail(long offset, long flags) {
621 citsmtp *sSMTP = SMTP;
623 if (StrLength(sSMTP->from) > 0) {
624 cprintf("503 Only one sender permitted\r\n");
628 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "From:", 5)) {
629 cprintf("501 Syntax error\r\n");
633 StrBufAppendBuf(sSMTP->from, sSMTP->Cmd, offset);
634 StrBufTrim(sSMTP->from);
635 if (strchr(ChrPtr(sSMTP->from), '<') != NULL) {
636 StrBufStripAllBut(sSMTP->from, '<', '>');
639 /* We used to reject empty sender names, until it was brought to our
640 * attention that RFC1123 5.2.9 requires that this be allowed. So now
641 * we allow it, but replace the empty string with a fake
642 * address so we don't have to contend with the empty string causing
643 * other code to fail when it's expecting something there.
645 if (StrLength(sSMTP->from) == 0) {
646 StrBufPlain(sSMTP->from, HKEY("someone@example.com"));
649 /* If this SMTP connection is from a logged-in user, force the 'from'
650 * to be the user's Internet e-mail address as Citadel knows it.
653 StrBufPlain(sSMTP->from, CC->cs_inet_email, -1);
654 cprintf("250 Sender ok <%s>\r\n", ChrPtr(sSMTP->from));
655 sSMTP->message_originated_locally = 1;
659 else if (sSMTP->is_lmtp) {
660 /* Bypass forgery checking for LMTP */
663 /* Otherwise, make sure outsiders aren't trying to forge mail from
664 * this system (unless, of course, c_allow_spoofing is enabled)
666 else if (CtdlGetConfigInt("c_allow_spoofing") == 0) {
667 process_rfc822_addr(ChrPtr(sSMTP->from), user, node, name);
668 syslog(LOG_DEBUG, "serv_smtp: claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
669 ChrPtr(sSMTP->from), user, node, name
671 if (CtdlHostAlias(node) != hostalias_nomatch) {
672 cprintf("550 You must log in to send mail from %s\r\n", node);
673 FlushStrBuf(sSMTP->from);
674 syslog(LOG_DEBUG, "serv_smtp: rejecting unauthenticated mail from %s", node);
679 cprintf("250 Sender ok\r\n");
685 * Implements the "RCPT To:" command
687 void smtp_rcpt(long offset, long flags)
689 char message_to_spammer[SIZ];
690 struct recptypes *valid = NULL;
691 citsmtp *sSMTP = SMTP;
693 if (StrLength(sSMTP->from) == 0) {
694 cprintf("503 Need MAIL before RCPT\r\n");
698 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "To:", 3)) {
699 cprintf("501 Syntax error\r\n");
703 if ( (sSMTP->is_msa) && (!CC->logged_in) ) {
704 cprintf("550 You must log in to send mail on this port.\r\n");
705 FlushStrBuf(sSMTP->from);
708 FlushStrBuf(sSMTP->OneRcpt);
709 StrBufAppendBuf(sSMTP->OneRcpt, sSMTP->Cmd, offset + 3);
710 StrBufTrim(sSMTP->OneRcpt);
711 StrBufStripAllBut(sSMTP->OneRcpt, '<', '>');
713 if ( (StrLength(sSMTP->OneRcpt) + StrLength(sSMTP->recipients)) >= SIZ) {
714 cprintf("452 Too many recipients\r\n");
719 if ( (!CC->logged_in) /* Don't RBL authenticated users */
720 && (!sSMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
721 if (CtdlGetConfigInt("c_rbl_at_greeting") == 0) { /* Don't RBL again if we already did it */
722 if (rbl_check(CC->cs_addr, message_to_spammer)) {
723 if (server_shutting_down)
724 cprintf("421 %s\r\n", message_to_spammer);
726 cprintf("550 %s\r\n", message_to_spammer);
727 /* no need to free_recipients(valid), it's not allocated yet */
733 valid = validate_recipients(
734 ChrPtr(sSMTP->OneRcpt),
735 smtp_get_Recipients(),
736 (sSMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
738 if (valid->num_error != 0) {
739 cprintf("550 %s\r\n", valid->errormsg);
740 free_recipients(valid);
744 if (valid->num_internet > 0) {
746 if (CtdlCheckInternetMailPermission(&CC->user)==0) {
747 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
748 ChrPtr(sSMTP->OneRcpt));
749 free_recipients(valid);
755 if (valid->num_internet > 0) {
756 if ( (sSMTP->message_originated_locally == 0)
757 && (sSMTP->is_lmtp == 0) ) {
758 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(sSMTP->OneRcpt));
759 free_recipients(valid);
764 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(sSMTP->OneRcpt));
765 if (StrLength(sSMTP->recipients) > 0) {
766 StrBufAppendBufPlain(sSMTP->recipients, HKEY(","), 0);
768 StrBufAppendBuf(sSMTP->recipients, sSMTP->OneRcpt, 0);
769 sSMTP->number_of_recipients ++;
771 free_recipients(valid);
779 * Implements the DATA command
781 void smtp_data(long offset, long flags)
785 struct CtdlMessage *msg = NULL;
788 struct recptypes *valid;
791 citsmtp *sSMTP = SMTP;
793 if (StrLength(sSMTP->from) == 0) {
794 cprintf("503 Need MAIL command first.\r\n");
798 if (sSMTP->number_of_recipients < 1) {
799 cprintf("503 Need RCPT command first.\r\n");
803 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
805 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
806 defbody = NewStrBufPlain(NULL, SIZ);
808 if (defbody != NULL) {
809 if (sSMTP->is_lmtp && (CC->cs_UDSclientUID != -1)) {
812 "Received: from %s (Citadel from userid %ld)\n"
814 ChrPtr(sSMTP->helo_node),
815 (long int) CC->cs_UDSclientUID,
816 CtdlGetConfigStr("c_fqdn"),
822 "Received: from %s (%s [%s])\n"
824 ChrPtr(sSMTP->helo_node),
827 CtdlGetConfigStr("c_fqdn"),
831 body = CtdlReadMessageBodyBuf(HKEY("."), CtdlGetConfigLong("c_maxmsglen"), defbody, 1);
832 FreeStrBuf(&defbody);
834 cprintf("550 Unable to save message: internal error.\r\n");
838 syslog(LOG_DEBUG, "serv_smtp: converting message...");
839 msg = convert_internet_message_buf(&body);
841 /* If the user is locally authenticated, FORCE the From: header to
842 * show up as the real sender. Yes, this violates the RFC standard,
843 * but IT MAKES SENSE. If you prefer strict RFC adherence over
844 * common sense, you can disable this in the configuration.
846 * We also set the "message room name" ('O' field) to MAILROOM
847 * (which is Mail> on most systems) to prevent it from getting set
848 * to something ugly like "0000058008.Sent Items>" when the message
849 * is read with a Citadel client.
851 if ( (CC->logged_in) && (CtdlGetConfigInt("c_rfc822_strict_from") != CFG_SMTP_FROM_NOFILTER) ) {
854 if (!CM_IsEmpty(msg, erFc822Addr) &&
855 ((CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_CORRECT) ||
856 (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT) ) )
858 if (!IsEmptyStr(CC->cs_inet_email))
859 validemail = strcmp(CC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
861 (!IsEmptyStr(CC->cs_inet_other_emails)))
863 int num_secondary_emails = 0;
865 num_secondary_emails = num_tokens(CC->cs_inet_other_emails, '|');
866 for (i=0; i < num_secondary_emails && !validemail; ++i) {
868 extract_token(buf, CC->cs_inet_other_emails,i,'|',sizeof CC->cs_inet_other_emails);
869 validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
874 if (!validemail && (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT)) {
875 syslog(LOG_ERR, "serv_smtp: invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
876 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
880 CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
881 if (sSMTP->preferred_sender_name != NULL)
882 CM_SetField(msg, eAuthor, SKEY(sSMTP->preferred_sender_name));
884 CM_SetField(msg, eAuthor, CC->user.fullname, strlen(CC->user.fullname));
887 if (sSMTP->preferred_sender_email != NULL) {
888 CM_SetField(msg, erFc822Addr, SKEY(sSMTP->preferred_sender_email));
891 CM_SetField(msg, erFc822Addr, CC->cs_inet_email, strlen(CC->cs_inet_email));
896 /* Set the "envelope from" address */
897 CM_SetField(msg, eMessagePath, SKEY(sSMTP->from));
899 /* Set the "envelope to" address */
900 CM_SetField(msg, eenVelopeTo, SKEY(sSMTP->recipients));
902 /* Submit the message into the Citadel system. */
903 valid = validate_recipients(
904 ChrPtr(sSMTP->recipients),
905 smtp_get_Recipients(),
906 (sSMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
909 /* If there are modules that want to scan this message before final
910 * submission (such as virus checkers or spam filters), call them now
911 * and give them an opportunity to reject the message.
913 if (sSMTP->is_unfiltered) {
917 scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
920 if (scan_errors > 0) { /* We don't want this message! */
922 if (CM_IsEmpty(msg, eErrorMsg)) {
923 CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
926 StrBufPrintf(sSMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
929 else { /* Ok, we'll accept this message. */
930 msgnum = CtdlSubmitMsg(msg, valid, "");
932 StrBufPrintf(sSMTP->OneRcpt, "250 Message accepted.\r\n");
935 StrBufPrintf(sSMTP->OneRcpt, "550 Internal delivery error\r\n");
939 /* For SMTP and ESMTP, just print the result message. For LMTP, we
940 * have to print one result message for each recipient. Since there
941 * is nothing in Citadel which would cause different recipients to
942 * have different results, we can get away with just spitting out the
943 * same message once for each recipient.
945 if (sSMTP->is_lmtp) {
946 for (i=0; i<sSMTP->number_of_recipients; ++i) {
947 cputbuf(sSMTP->OneRcpt);
951 cputbuf(sSMTP->OneRcpt);
954 /* Write something to the syslog(which may or may not be where the
955 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
957 syslog((LOG_MAIL | LOG_INFO),
958 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
961 sSMTP->number_of_recipients,
964 ChrPtr(sSMTP->OneRcpt)
969 free_recipients(valid);
970 smtp_data_clear(0, 0); /* clear out the buffers now */
975 * implements the STARTTLS command
977 void smtp_starttls(long offset, long flags)
979 char ok_response[SIZ];
980 char nosup_response[SIZ];
981 char error_response[SIZ];
983 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
984 sprintf(nosup_response, "554 TLS not supported here\r\n");
985 sprintf(error_response, "554 Internal error\r\n");
986 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
992 * Main command loop for SMTP server sessions.
994 void smtp_command_loop(void) {
995 static const ConstStr AuthPlainStr = {HKEY("AUTH PLAIN")};
996 citsmtp *sSMTP = SMTP;
997 const char *pch, *pchs;
999 char CMD[MaxSMTPCmdLen + 1];
1001 if (sSMTP == NULL) {
1002 syslog(LOG_ERR, "serv_smtp: Session SMTP data is null. WTF? We will crash now.");
1007 if (CtdlClientGetLine(sSMTP->Cmd) < 1) {
1008 syslog(LOG_INFO, "SMTP: client disconnected: ending session.");
1009 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1012 syslog(LOG_DEBUG, "serv_smtp: %s", ChrPtr(sSMTP->Cmd));
1014 if (sSMTP->command_state == smtp_user) {
1015 if (!strncmp(ChrPtr(sSMTP->Cmd), AuthPlainStr.Key, AuthPlainStr.len)) {
1016 smtp_try_plain(0, 0);
1024 else if (sSMTP->command_state == smtp_password) {
1025 smtp_get_pass(0, 0);
1029 else if (sSMTP->command_state == smtp_plain) {
1030 smtp_try_plain(0, 0);
1034 pchs = pch = ChrPtr(sSMTP->Cmd);
1036 while ((*pch != '\0') &&
1038 (pch - pchs <= MaxSMTPCmdLen))
1040 CMD[i] = toupper(*pch);
1046 if ((*pch == '\0') ||
1051 if (GetHash(SMTPCmds, CMD, i, &v) &&
1054 smtp_handler_hook *h = (smtp_handler_hook*) v;
1056 if (isblank(pchs[i]))
1064 cprintf("502 I'm afraid I can't do that.\r\n");
1067 void smtp_noop(long offest, long Flags)
1069 cprintf("250 NOOP\r\n");
1072 void smtp_quit(long offest, long Flags)
1074 cprintf("221 Goodbye...\r\n");
1075 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1078 /*****************************************************************************/
1079 /* MODULE INITIALIZATION STUFF */
1080 /*****************************************************************************/
1082 * This cleanup function blows away the temporary memory used by
1085 void smtp_cleanup_function(void)
1087 citsmtp *sSMTP = SMTP;
1089 /* Don't do this stuff if this is not an SMTP session! */
1090 if (CC->h_command_function != smtp_command_loop) return;
1092 syslog(LOG_DEBUG, "Performing SMTP cleanup hook");
1094 FreeStrBuf(&sSMTP->Cmd);
1095 FreeStrBuf(&sSMTP->helo_node);
1096 FreeStrBuf(&sSMTP->from);
1097 FreeStrBuf(&sSMTP->recipients);
1098 FreeStrBuf(&sSMTP->OneRcpt);
1099 FreeStrBuf(&sSMTP->preferred_sender_email);
1100 FreeStrBuf(&sSMTP->preferred_sender_name);
1105 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1106 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1107 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1108 const char *CitadelServiceSMTP_LMTP="LMTP";
1109 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1112 CTDL_MODULE_INIT(smtp)
1115 SMTPCmds = NewHash(1, NULL);
1117 RegisterSmtpCMD("AUTH", smtp_auth, 0);
1118 RegisterSmtpCMD("DATA", smtp_data, 0);
1119 RegisterSmtpCMD("HELO", smtp_hello, HELO);
1120 RegisterSmtpCMD("EHLO", smtp_hello, EHLO);
1121 RegisterSmtpCMD("LHLO", smtp_hello, LHLO);
1122 RegisterSmtpCMD("HELP", smtp_help, 0);
1123 RegisterSmtpCMD("MAIL", smtp_mail, 0);
1124 RegisterSmtpCMD("NOOP", smtp_noop, 0);
1125 RegisterSmtpCMD("QUIT", smtp_quit, 0);
1126 RegisterSmtpCMD("RCPT", smtp_rcpt, 0);
1127 RegisterSmtpCMD("RSET", smtp_rset, 1);
1129 RegisterSmtpCMD("STARTTLS", smtp_starttls, 0);
1133 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtp_port"), /* SMTP MTA */
1138 CitadelServiceSMTP_MTA);
1141 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtps_port"), /* SMTPS MTA */
1146 CitadelServiceSMTPS_MTA);
1149 CtdlRegisterServiceHook(CtdlGetConfigInt("c_msa_port"), /* SMTP MSA */
1154 CitadelServiceSMTP_MSA);
1156 CtdlRegisterServiceHook(0, /* local LMTP */
1161 CitadelServiceSMTP_LMTP);
1163 CtdlRegisterServiceHook(0, /* local LMTP */
1164 file_lmtp_unfiltered_socket,
1165 lmtp_unfiltered_greeting,
1168 CitadelServiceSMTP_LMTP_UNF);
1170 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1173 /* return our module name for the log */