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 struct CitContext *CCC = CC;
231 cprintf("235 Hello, %s\r\n", CCC->user.fullname);
232 syslog(LOG_NOTICE, "SMTP authenticated %s", CCC->user.fullname);
233 CCC->internal_pgm = 0;
234 CCC->cs_flags &= ~CS_STEALTH;
239 * Implement HELO and EHLO commands.
241 * which_command: 0=HELO, 1=EHLO, 2=LHLO
243 void smtp_hello(long offset, long which_command)
245 struct CitContext *CCC = CC;
246 citsmtp *sSMTP = SMTP;
248 StrBufAppendBuf (sSMTP->helo_node, sSMTP->Cmd, offset);
250 if ( (which_command != LHLO) && (sSMTP->is_lmtp) ) {
251 cprintf("500 Only LHLO is allowed when running LMTP\r\n");
255 if ( (which_command == LHLO) && (sSMTP->is_lmtp == 0) ) {
256 cprintf("500 LHLO is only allowed when running LMTP\r\n");
260 if (which_command == HELO) {
261 cprintf("250 Hello %s (%s [%s])\r\n",
262 ChrPtr(sSMTP->helo_node),
268 if (which_command == EHLO) {
269 cprintf("250-Hello %s (%s [%s])\r\n",
270 ChrPtr(sSMTP->helo_node),
276 cprintf("250-Greetings and joyous salutations.\r\n");
278 cprintf("250-HELP\r\n");
279 cprintf("250-SIZE %ld\r\n", CtdlGetConfigLong("c_maxmsglen"));
283 * Offer TLS, but only if TLS is not already active.
284 * Furthermore, only offer TLS when running on
285 * the SMTP-MSA port, not on the SMTP-MTA port, due to
286 * questionable reliability of TLS in certain sending MTA's.
288 if ( (!CCC->redirect_ssl) && (sSMTP->is_msa) ) {
289 cprintf("250-STARTTLS\r\n");
291 #endif /* HAVE_OPENSSL */
293 cprintf("250-AUTH LOGIN PLAIN\r\n"
294 "250-AUTH=LOGIN PLAIN\r\n"
302 * Backend function for smtp_webcit_preferences_hack().
303 * Look at a message and determine if it's the preferences file.
305 void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
306 struct CtdlMessage *msg;
307 char **webcit_conf = (char **) userdata;
310 return; // already got it
313 msg = CtdlFetchMessage(msgnum, 1);
318 if ( !CM_IsEmpty(msg, eMsgSubject) &&
319 (!strcasecmp(msg->cm_fields[eMsgSubject], "__ WebCit Preferences __")))
321 /* This is it! Change ownership of the message text so it doesn't get freed. */
322 *webcit_conf = (char *)msg->cm_fields[eMesageText];
323 msg->cm_fields[eMesageText] = NULL;
330 * The configuration item for the user's preferred display name for outgoing email is, unfortunately,
331 * stored in the account's WebCit configuration. We have to fetch it now.
333 void smtp_webcit_preferences_hack(void) {
334 struct CitContext *CCC = CC;
335 char config_roomname[ROOMNAMELEN];
336 char *webcit_conf = NULL;
337 citsmtp *sSMTP = SMTP;
339 snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CCC->user.usernum, USERCONFIGROOM);
340 if (CtdlGetRoom(&CCC->room, config_roomname) != 0) {
345 * Find the WebCit configuration message
348 CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
354 /* Parse the webcit configuration and attempt to do something useful with it */
355 char *str = webcit_conf;
357 char *this_line = NULL;
358 while (this_line = strtok_r(str, "\n", &saveptr), this_line != NULL) {
360 if (!strncasecmp(this_line, "defaultfrom|", 12)) {
361 sSMTP->preferred_sender_email = NewStrBufPlain(&this_line[12], -1);
363 if (!strncasecmp(this_line, "defaultname|", 12)) {
364 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
366 if ((!strncasecmp(this_line, "defaultname|", 12)) && (sSMTP->preferred_sender_name == NULL)) {
367 sSMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
377 * Implement HELP command.
379 void smtp_help(long offset, long Flags) {
380 cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
387 void smtp_get_user(long offset)
390 citsmtp *sSMTP = SMTP;
392 StrBufDecodeBase64(sSMTP->Cmd);
394 if (CtdlLoginExistingUser(ChrPtr(sSMTP->Cmd)) == login_ok) {
395 size_t len = CtdlEncodeBase64(buf, "Password:", 9, 0);
397 if (buf[len - 1] == '\n') {
400 cprintf("334 %s\r\n", buf);
401 sSMTP->command_state = smtp_password;
404 cprintf("500 No such user.\r\n");
405 sSMTP->command_state = smtp_command;
413 void smtp_get_pass(long offset, long Flags)
415 citsmtp *sSMTP = SMTP;
418 memset(password, 0, sizeof(password));
419 StrBufDecodeBase64(sSMTP->Cmd);
420 syslog(LOG_DEBUG, "Trying <%s>", password);
421 if (CtdlTryPassword(SKEY(sSMTP->Cmd)) == pass_ok) {
422 smtp_auth_greeting(offset, Flags);
425 cprintf("535 Authentication failed.\r\n");
427 sSMTP->command_state = smtp_command;
432 * Back end for PLAIN auth method (either inline or multistate)
434 void smtp_try_plain(long offset, long Flags)
436 citsmtp *sSMTP = SMTP;
437 const char*decoded_authstring;
438 char ident[256] = "";
447 memset(pass, 0, sizeof(pass));
448 decoded_len = StrBufDecodeBase64(sSMTP->Cmd);
452 decoded_authstring = ChrPtr(sSMTP->Cmd);
454 len = safestrncpy(ident, decoded_authstring, sizeof ident);
456 decoded_len -= len - 1;
457 decoded_authstring += len + 1;
461 len = safestrncpy(user, decoded_authstring, sizeof user);
463 decoded_authstring += len + 1;
464 decoded_len -= len - 1;
469 plen = safestrncpy(pass, decoded_authstring, sizeof pass);
472 plen = sizeof(pass) - 1;
476 sSMTP->command_state = smtp_command;
478 if (!IsEmptyStr(ident)) {
479 result = CtdlLoginExistingUser(ident);
482 result = CtdlLoginExistingUser(user);
485 if (result == login_ok) {
486 if (CtdlTryPassword(pass, plen) == pass_ok) {
487 smtp_webcit_preferences_hack();
488 smtp_auth_greeting(offset, Flags);
492 cprintf("504 Authentication failed.\r\n");
497 * Attempt to perform authenticated SMTP
499 void smtp_auth(long offset, long Flags)
501 struct CitContext *CCC = CC;
502 citsmtp *sSMTP = SMTP;
503 char username_prompt[64];
505 char encoded_authstring[1024];
507 if (CCC->logged_in) {
508 cprintf("504 Already logged in.\r\n");
512 extract_token(method, ChrPtr(sSMTP->Cmd) + offset, 0, ' ', sizeof method);
514 if (!strncasecmp(method, "login", 5) ) {
515 if (StrLength(sSMTP->Cmd) - offset >= 7) {
519 size_t len = CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
520 if (username_prompt[len - 1] == '\n') {
521 username_prompt[len - 1] = '\0';
523 cprintf("334 %s\r\n", username_prompt);
524 sSMTP->command_state = smtp_user;
529 if (!strncasecmp(method, "plain", 5) ) {
531 if (num_tokens(ChrPtr(sSMTP->Cmd) + offset, ' ') < 2) {
533 SMTP->command_state = smtp_plain;
537 len = extract_token(encoded_authstring,
538 ChrPtr(sSMTP->Cmd) + offset,
540 sizeof encoded_authstring);
541 StrBufPlain(sSMTP->Cmd, encoded_authstring, len);
542 smtp_try_plain(0, Flags);
546 if (strncasecmp(method, "login", 5) ) {
547 cprintf("504 Unknown authentication method.\r\n");
555 * Implements the RSET (reset state) command.
556 * Currently this just zeroes out the state buffer. If pointers to data
557 * allocated with malloc() are ever placed in the state buffer, we have to
558 * be sure to free() them first!
560 * Set do_response to nonzero to output the SMTP RSET response code.
562 void smtp_rset(long offset, long do_response) {
563 citsmtp *sSMTP = SMTP;
566 * Our entire SMTP state is discarded when a RSET command is issued,
567 * but we need to preserve this one little piece of information, so
568 * we save it for later.
571 FlushStrBuf(sSMTP->Cmd);
572 FlushStrBuf(sSMTP->helo_node);
573 FlushStrBuf(sSMTP->from);
574 FlushStrBuf(sSMTP->recipients);
575 FlushStrBuf(sSMTP->OneRcpt);
577 sSMTP->command_state = 0;
578 sSMTP->number_of_recipients = 0;
579 sSMTP->delivery_mode = 0;
580 sSMTP->message_originated_locally = 0;
583 * we must remember is_lmtp & is_unfiltered.
587 * It is somewhat ambiguous whether we want to log out when a RSET
588 * command is issued. Here's the code to do it. It is commented out
589 * because some clients (such as Pine) issue RSET commands before
590 * each message, but still expect to be logged in.
592 * if (CC->logged_in) {
598 cprintf("250 Zap!\r\n");
603 * Clear out the portions of the state buffer that need to be cleared out
604 * after the DATA command finishes.
606 void smtp_data_clear(long offset, long flags)
608 citsmtp *sSMTP = SMTP;
610 FlushStrBuf(sSMTP->from);
611 FlushStrBuf(sSMTP->recipients);
612 FlushStrBuf(sSMTP->OneRcpt);
613 sSMTP->number_of_recipients = 0;
614 sSMTP->delivery_mode = 0;
615 sSMTP->message_originated_locally = 0;
619 * Implements the "MAIL FROM:" command
621 void smtp_mail(long offset, long flags) {
625 struct CitContext *CCC = CC;
626 citsmtp *sSMTP = SMTP;
628 if (StrLength(sSMTP->from) > 0) {
629 cprintf("503 Only one sender permitted\r\n");
633 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "From:", 5)) {
634 cprintf("501 Syntax error\r\n");
638 StrBufAppendBuf(sSMTP->from, sSMTP->Cmd, offset);
639 StrBufTrim(sSMTP->from);
640 if (strchr(ChrPtr(sSMTP->from), '<') != NULL) {
641 StrBufStripAllBut(sSMTP->from, '<', '>');
644 /* We used to reject empty sender names, until it was brought to our
645 * attention that RFC1123 5.2.9 requires that this be allowed. So now
646 * we allow it, but replace the empty string with a fake
647 * address so we don't have to contend with the empty string causing
648 * other code to fail when it's expecting something there.
650 if (StrLength(sSMTP->from) == 0) {
651 StrBufPlain(sSMTP->from, HKEY("someone@example.com"));
654 /* If this SMTP connection is from a logged-in user, force the 'from'
655 * to be the user's Internet e-mail address as Citadel knows it.
657 if (CCC->logged_in) {
658 StrBufPlain(sSMTP->from, CCC->cs_inet_email, -1);
659 cprintf("250 Sender ok <%s>\r\n", ChrPtr(sSMTP->from));
660 sSMTP->message_originated_locally = 1;
664 else if (sSMTP->is_lmtp) {
665 /* Bypass forgery checking for LMTP */
668 /* Otherwise, make sure outsiders aren't trying to forge mail from
669 * this system (unless, of course, c_allow_spoofing is enabled)
671 else if (CtdlGetConfigInt("c_allow_spoofing") == 0) {
672 process_rfc822_addr(ChrPtr(sSMTP->from), user, node, name);
673 syslog(LOG_DEBUG, "Claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
674 ChrPtr(sSMTP->from), user, node, name
676 if (CtdlHostAlias(node) != hostalias_nomatch) {
677 cprintf("550 You must log in to send mail from %s\r\n", node);
678 FlushStrBuf(sSMTP->from);
679 syslog(LOG_DEBUG, "Rejecting unauthenticated mail from %s", node);
684 cprintf("250 Sender ok\r\n");
690 * Implements the "RCPT To:" command
692 void smtp_rcpt(long offset, long flags)
694 struct CitContext *CCC = CC;
695 char message_to_spammer[SIZ];
696 recptypes *valid = NULL;
697 citsmtp *sSMTP = SMTP;
699 if (StrLength(sSMTP->from) == 0) {
700 cprintf("503 Need MAIL before RCPT\r\n");
704 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "To:", 3)) {
705 cprintf("501 Syntax error\r\n");
709 if ( (sSMTP->is_msa) && (!CCC->logged_in) ) {
710 cprintf("550 You must log in to send mail on this port.\r\n");
711 FlushStrBuf(sSMTP->from);
714 FlushStrBuf(sSMTP->OneRcpt);
715 StrBufAppendBuf(sSMTP->OneRcpt, sSMTP->Cmd, offset + 3);
716 StrBufTrim(sSMTP->OneRcpt);
717 StrBufStripAllBut(sSMTP->OneRcpt, '<', '>');
719 if ( (StrLength(sSMTP->OneRcpt) + StrLength(sSMTP->recipients)) >= SIZ) {
720 cprintf("452 Too many recipients\r\n");
725 if ( (!CCC->logged_in) /* Don't RBL authenticated users */
726 && (!sSMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
727 if (CtdlGetConfigInt("c_rbl_at_greeting") == 0) { /* Don't RBL again if we already did it */
728 if (rbl_check(CC->cs_addr, message_to_spammer)) {
729 if (server_shutting_down)
730 cprintf("421 %s\r\n", message_to_spammer);
732 cprintf("550 %s\r\n", message_to_spammer);
733 /* no need to free_recipients(valid), it's not allocated yet */
739 valid = validate_recipients(
740 ChrPtr(sSMTP->OneRcpt),
741 smtp_get_Recipients(),
742 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
744 if (valid->num_error != 0) {
745 cprintf("550 %s\r\n", valid->errormsg);
746 free_recipients(valid);
750 if (valid->num_internet > 0) {
751 if (CCC->logged_in) {
752 if (CtdlCheckInternetMailPermission(&CCC->user)==0) {
753 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
754 ChrPtr(sSMTP->OneRcpt));
755 free_recipients(valid);
761 if (valid->num_internet > 0) {
762 if ( (sSMTP->message_originated_locally == 0)
763 && (sSMTP->is_lmtp == 0) ) {
764 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(sSMTP->OneRcpt));
765 free_recipients(valid);
770 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(sSMTP->OneRcpt));
771 if (StrLength(sSMTP->recipients) > 0) {
772 StrBufAppendBufPlain(sSMTP->recipients, HKEY(","), 0);
774 StrBufAppendBuf(sSMTP->recipients, sSMTP->OneRcpt, 0);
775 sSMTP->number_of_recipients ++;
777 free_recipients(valid);
785 * Implements the DATA command
787 void smtp_data(long offset, long flags)
789 struct CitContext *CCC = CC;
792 struct CtdlMessage *msg = NULL;
798 citsmtp *sSMTP = SMTP;
800 if (StrLength(sSMTP->from) == 0) {
801 cprintf("503 Need MAIL command first.\r\n");
805 if (sSMTP->number_of_recipients < 1) {
806 cprintf("503 Need RCPT command first.\r\n");
810 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
812 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
813 defbody = NewStrBufPlain(NULL, SIZ);
815 if (defbody != NULL) {
816 if (sSMTP->is_lmtp && (CCC->cs_UDSclientUID != -1)) {
819 "Received: from %s (Citadel from userid %ld)\n"
821 ChrPtr(sSMTP->helo_node),
822 (long int) CCC->cs_UDSclientUID,
823 CtdlGetConfigStr("c_fqdn"),
829 "Received: from %s (%s [%s])\n"
831 ChrPtr(sSMTP->helo_node),
834 CtdlGetConfigStr("c_fqdn"),
838 body = CtdlReadMessageBodyBuf(HKEY("."), CtdlGetConfigLong("c_maxmsglen"), defbody, 1);
839 FreeStrBuf(&defbody);
841 cprintf("550 Unable to save message: internal error.\r\n");
845 syslog(LOG_DEBUG, "Converting message...");
846 msg = convert_internet_message_buf(&body);
848 /* If the user is locally authenticated, FORCE the From: header to
849 * show up as the real sender. Yes, this violates the RFC standard,
850 * but IT MAKES SENSE. If you prefer strict RFC adherence over
851 * common sense, you can disable this in the configuration.
853 * We also set the "message room name" ('O' field) to MAILROOM
854 * (which is Mail> on most systems) to prevent it from getting set
855 * to something ugly like "0000058008.Sent Items>" when the message
856 * is read with a Citadel client.
858 if ( (CCC->logged_in) && (CtdlGetConfigInt("c_rfc822_strict_from") != CFG_SMTP_FROM_NOFILTER) ) {
861 if (!CM_IsEmpty(msg, erFc822Addr) &&
862 ((CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_CORRECT) ||
863 (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT) ) )
865 if (!IsEmptyStr(CCC->cs_inet_email))
866 validemail = strcmp(CCC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
868 (!IsEmptyStr(CCC->cs_inet_other_emails)))
870 int num_secondary_emails = 0;
872 num_secondary_emails = num_tokens(CCC->cs_inet_other_emails, '|');
873 for (i=0; i < num_secondary_emails && !validemail; ++i) {
875 extract_token(buf, CCC->cs_inet_other_emails,i,'|',sizeof CCC->cs_inet_other_emails);
876 validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
881 if (!validemail && (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT)) {
882 syslog(LOG_ERR, "invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
883 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
887 CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
888 if (sSMTP->preferred_sender_name != NULL)
889 CM_SetField(msg, eAuthor, SKEY(sSMTP->preferred_sender_name));
891 CM_SetField(msg, eAuthor, CCC->user.fullname, strlen(CCC->user.fullname));
894 if (sSMTP->preferred_sender_email != NULL)
895 CM_SetField(msg, erFc822Addr, SKEY(sSMTP->preferred_sender_email));
897 CM_SetField(msg, erFc822Addr, CCC->cs_inet_email, strlen(CCC->cs_inet_email));
901 /* Set the "envelope from" address */
902 CM_SetField(msg, eMessagePath, SKEY(sSMTP->from));
904 /* Set the "envelope to" address */
905 CM_SetField(msg, eenVelopeTo, SKEY(sSMTP->recipients));
907 /* Submit the message into the Citadel system. */
908 valid = validate_recipients(
909 ChrPtr(sSMTP->recipients),
910 smtp_get_Recipients(),
911 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
914 /* If there are modules that want to scan this message before final
915 * submission (such as virus checkers or spam filters), call them now
916 * and give them an opportunity to reject the message.
918 if (sSMTP->is_unfiltered) {
922 scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
925 if (scan_errors > 0) { /* We don't want this message! */
927 if (CM_IsEmpty(msg, eErrorMsg)) {
928 CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
931 StrBufPrintf(sSMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
934 else { /* Ok, we'll accept this message. */
935 msgnum = CtdlSubmitMsg(msg, valid, "");
937 StrBufPrintf(sSMTP->OneRcpt, "250 Message accepted.\r\n");
940 StrBufPrintf(sSMTP->OneRcpt, "550 Internal delivery error\r\n");
944 /* For SMTP and ESMTP, just print the result message. For LMTP, we
945 * have to print one result message for each recipient. Since there
946 * is nothing in Citadel which would cause different recipients to
947 * have different results, we can get away with just spitting out the
948 * same message once for each recipient.
950 if (sSMTP->is_lmtp) {
951 for (i=0; i<sSMTP->number_of_recipients; ++i) {
952 cputbuf(sSMTP->OneRcpt);
956 cputbuf(sSMTP->OneRcpt);
959 /* Write something to the syslog(which may or may not be where the
960 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
962 syslog((LOG_MAIL | LOG_INFO),
963 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
966 sSMTP->number_of_recipients,
969 ChrPtr(sSMTP->OneRcpt)
974 free_recipients(valid);
975 smtp_data_clear(0, 0); /* clear out the buffers now */
980 * implements the STARTTLS command
982 void smtp_starttls(long offset, long flags)
984 char ok_response[SIZ];
985 char nosup_response[SIZ];
986 char error_response[SIZ];
988 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
989 sprintf(nosup_response, "554 TLS not supported here\r\n");
990 sprintf(error_response, "554 Internal error\r\n");
991 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
997 * Main command loop for SMTP server sessions.
999 void smtp_command_loop(void)
1001 static const ConstStr AuthPlainStr = {HKEY("AUTH PLAIN")};
1002 struct CitContext *CCC = CC;
1003 citsmtp *sSMTP = SMTP;
1004 const char *pch, *pchs;
1006 char CMD[MaxSMTPCmdLen + 1];
1008 if (sSMTP == NULL) {
1009 syslog(LOG_EMERG, "Session SMTP data is null. WTF? We will crash now.");
1013 time(&CCC->lastcmd);
1014 if (CtdlClientGetLine(sSMTP->Cmd) < 1) {
1015 syslog(LOG_CRIT, "SMTP: client disconnected: ending session.");
1016 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1019 syslog(LOG_DEBUG, "SMTP server: %s", ChrPtr(sSMTP->Cmd));
1021 if (sSMTP->command_state == smtp_user) {
1022 if (!strncmp(ChrPtr(sSMTP->Cmd), AuthPlainStr.Key, AuthPlainStr.len))
1023 smtp_try_plain(0, 0);
1029 else if (sSMTP->command_state == smtp_password) {
1030 smtp_get_pass(0, 0);
1034 else if (sSMTP->command_state == smtp_plain) {
1035 smtp_try_plain(0, 0);
1039 pchs = pch = ChrPtr(sSMTP->Cmd);
1041 while ((*pch != '\0') &&
1043 (pch - pchs <= MaxSMTPCmdLen))
1045 CMD[i] = toupper(*pch);
1051 if ((*pch == '\0') ||
1056 if (GetHash(SMTPCmds, CMD, i, &v) &&
1059 smtp_handler_hook *h = (smtp_handler_hook*) v;
1061 if (isblank(pchs[i]))
1069 cprintf("502 I'm afraid I can't do that.\r\n");
1072 void smtp_noop(long offest, long Flags)
1074 cprintf("250 NOOP\r\n");
1077 void smtp_quit(long offest, long Flags)
1079 cprintf("221 Goodbye...\r\n");
1080 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1083 /*****************************************************************************/
1084 /* MODULE INITIALIZATION STUFF */
1085 /*****************************************************************************/
1087 * This cleanup function blows away the temporary memory used by
1090 void smtp_cleanup_function(void)
1092 citsmtp *sSMTP = SMTP;
1093 struct CitContext *CCC = CC;
1095 /* Don't do this stuff if this is not an SMTP session! */
1096 if (CCC->h_command_function != smtp_command_loop) return;
1098 syslog(LOG_DEBUG, "Performing SMTP cleanup hook");
1100 FreeStrBuf(&sSMTP->Cmd);
1101 FreeStrBuf(&sSMTP->helo_node);
1102 FreeStrBuf(&sSMTP->from);
1103 FreeStrBuf(&sSMTP->recipients);
1104 FreeStrBuf(&sSMTP->OneRcpt);
1105 FreeStrBuf(&sSMTP->preferred_sender_email);
1106 FreeStrBuf(&sSMTP->preferred_sender_name);
1111 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1112 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1113 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1114 const char *CitadelServiceSMTP_LMTP="LMTP";
1115 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1118 CTDL_MODULE_INIT(smtp)
1122 SMTPCmds = NewHash(1, NULL);
1124 RegisterSmtpCMD("AUTH", smtp_auth, 0);
1125 RegisterSmtpCMD("DATA", smtp_data, 0);
1126 RegisterSmtpCMD("HELO", smtp_hello, HELO);
1127 RegisterSmtpCMD("EHLO", smtp_hello, EHLO);
1128 RegisterSmtpCMD("LHLO", smtp_hello, LHLO);
1129 RegisterSmtpCMD("HELP", smtp_help, 0);
1130 RegisterSmtpCMD("MAIL", smtp_mail, 0);
1131 RegisterSmtpCMD("NOOP", smtp_noop, 0);
1132 RegisterSmtpCMD("QUIT", smtp_quit, 0);
1133 RegisterSmtpCMD("RCPT", smtp_rcpt, 0);
1134 RegisterSmtpCMD("RSET", smtp_rset, 1);
1136 RegisterSmtpCMD("STARTTLS", smtp_starttls, 0);
1140 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtp_port"), /* SMTP MTA */
1145 CitadelServiceSMTP_MTA);
1148 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtps_port"), /* SMTPS MTA */
1153 CitadelServiceSMTPS_MTA);
1156 CtdlRegisterServiceHook(CtdlGetConfigInt("c_msa_port"), /* SMTP MSA */
1161 CitadelServiceSMTP_MSA);
1163 CtdlRegisterServiceHook(0, /* local LMTP */
1168 CitadelServiceSMTP_LMTP);
1170 CtdlRegisterServiceHook(0, /* local LMTP */
1171 file_lmtp_unfiltered_socket,
1172 lmtp_unfiltered_greeting,
1175 CitadelServiceSMTP_LMTP_UNF);
1177 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1180 /* return our module name for the log */