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) 1998-2015 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 ( (CtdlGetConfigInt("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", CtdlGetConfigStr("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", CtdlGetConfigLong("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, 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)
397 citsmtp *sSMTP = SMTP;
399 StrBufDecodeBase64(sSMTP->Cmd);
401 /* syslog(LOG_DEBUG, "Trying <%s>\n", username); */
402 if (CtdlLoginExistingUser(NULL, ChrPtr(sSMTP->Cmd)) == login_ok) {
403 size_t len = CtdlEncodeBase64(buf, "Password:", 9, 0);
405 if (buf[len - 1] == '\n') {
408 cprintf("334 %s\r\n", buf);
409 sSMTP->command_state = smtp_password;
412 cprintf("500 No such user.\r\n");
413 sSMTP->command_state = smtp_command;
421 void smtp_get_pass(long offset, long Flags)
423 citsmtp *sSMTP = SMTP;
426 memset(password, 0, sizeof(password));
427 StrBufDecodeBase64(sSMTP->Cmd);
428 /* syslog(LOG_DEBUG, "Trying <%s>\n", password); */
429 if (CtdlTryPassword(SKEY(sSMTP->Cmd)) == pass_ok) {
430 smtp_auth_greeting(offset, Flags);
433 cprintf("535 Authentication failed.\r\n");
435 sSMTP->command_state = smtp_command;
440 * Back end for PLAIN auth method (either inline or multistate)
442 void smtp_try_plain(long offset, long Flags)
444 citsmtp *sSMTP = SMTP;
445 const char*decoded_authstring;
446 char ident[256] = "";
455 memset(pass, 0, sizeof(pass));
456 decoded_len = StrBufDecodeBase64(sSMTP->Cmd);
460 decoded_authstring = ChrPtr(sSMTP->Cmd);
462 len = safestrncpy(ident, decoded_authstring, sizeof ident);
464 decoded_len -= len - 1;
465 decoded_authstring += len + 1;
469 len = safestrncpy(user, decoded_authstring, sizeof user);
471 decoded_authstring += len + 1;
472 decoded_len -= len - 1;
477 plen = safestrncpy(pass, decoded_authstring, sizeof pass);
480 plen = sizeof(pass) - 1;
484 sSMTP->command_state = smtp_command;
486 if (!IsEmptyStr(ident)) {
487 result = CtdlLoginExistingUser(user, ident);
490 result = CtdlLoginExistingUser(NULL, user);
493 if (result == login_ok) {
494 if (CtdlTryPassword(pass, plen) == pass_ok) {
495 smtp_webcit_preferences_hack();
496 smtp_auth_greeting(offset, Flags);
500 cprintf("504 Authentication failed.\r\n");
505 * Attempt to perform authenticated SMTP
507 void smtp_auth(long offset, long Flags)
509 citsmtp *sSMTP = SMTP;
510 char username_prompt[64];
512 char encoded_authstring[1024];
515 cprintf("504 Already logged in.\r\n");
519 extract_token(method, ChrPtr(sSMTP->Cmd) + offset, 0, ' ', sizeof method);
521 if (!strncasecmp(method, "login", 5) ) {
522 if (StrLength(sSMTP->Cmd) - offset >= 7) {
526 size_t len = CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
527 if (username_prompt[len - 1] == '\n') {
528 username_prompt[len - 1] = '\0';
530 cprintf("334 %s\r\n", username_prompt);
531 sSMTP->command_state = smtp_user;
536 if (!strncasecmp(method, "plain", 5) ) {
538 if (num_tokens(ChrPtr(sSMTP->Cmd) + offset, ' ') < 2) {
540 SMTP->command_state = smtp_plain;
544 len = extract_token(encoded_authstring,
545 ChrPtr(sSMTP->Cmd) + offset,
547 sizeof encoded_authstring);
548 StrBufPlain(sSMTP->Cmd, encoded_authstring, len);
549 smtp_try_plain(0, Flags);
553 if (strncasecmp(method, "login", 5) ) {
554 cprintf("504 Unknown authentication method.\r\n");
562 * Implements the RSET (reset state) command.
563 * Currently this just zeroes out the state buffer. If pointers to data
564 * allocated with malloc() are ever placed in the state buffer, we have to
565 * be sure to free() them first!
567 * Set do_response to nonzero to output the SMTP RSET response code.
569 void smtp_rset(long offset, long do_response) {
570 citsmtp *sSMTP = SMTP;
573 * Our entire SMTP state is discarded when a RSET command is issued,
574 * but we need to preserve this one little piece of information, so
575 * we save it for later.
578 FlushStrBuf(sSMTP->Cmd);
579 FlushStrBuf(sSMTP->helo_node);
580 FlushStrBuf(sSMTP->from);
581 FlushStrBuf(sSMTP->recipients);
582 FlushStrBuf(sSMTP->OneRcpt);
584 sSMTP->command_state = 0;
585 sSMTP->number_of_recipients = 0;
586 sSMTP->delivery_mode = 0;
587 sSMTP->message_originated_locally = 0;
590 * we must remember is_lmtp & is_unfiltered.
594 * It is somewhat ambiguous whether we want to log out when a RSET
595 * command is issued. Here's the code to do it. It is commented out
596 * because some clients (such as Pine) issue RSET commands before
597 * each message, but still expect to be logged in.
599 * if (CC->logged_in) {
605 cprintf("250 Zap!\r\n");
610 * Clear out the portions of the state buffer that need to be cleared out
611 * after the DATA command finishes.
613 void smtp_data_clear(long offset, long flags)
615 citsmtp *sSMTP = SMTP;
617 FlushStrBuf(sSMTP->from);
618 FlushStrBuf(sSMTP->recipients);
619 FlushStrBuf(sSMTP->OneRcpt);
620 sSMTP->number_of_recipients = 0;
621 sSMTP->delivery_mode = 0;
622 sSMTP->message_originated_locally = 0;
626 * Implements the "MAIL FROM:" command
628 void smtp_mail(long offset, long flags) {
632 citsmtp *sSMTP = SMTP;
634 if (StrLength(sSMTP->from) > 0) {
635 cprintf("503 Only one sender permitted\r\n");
639 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "From:", 5)) {
640 cprintf("501 Syntax error\r\n");
644 StrBufAppendBuf(sSMTP->from, sSMTP->Cmd, offset);
645 StrBufTrim(sSMTP->from);
646 if (strchr(ChrPtr(sSMTP->from), '<') != NULL) {
647 StrBufStripAllBut(sSMTP->from, '<', '>');
650 /* We used to reject empty sender names, until it was brought to our
651 * attention that RFC1123 5.2.9 requires that this be allowed. So now
652 * we allow it, but replace the empty string with a fake
653 * address so we don't have to contend with the empty string causing
654 * other code to fail when it's expecting something there.
656 if (StrLength(sSMTP->from) == 0) {
657 StrBufPlain(sSMTP->from, HKEY("someone@example.com"));
660 /* If this SMTP connection is from a logged-in user, force the 'from'
661 * to be the user's Internet e-mail address as Citadel knows it.
664 StrBufPlain(sSMTP->from, CC->cs_inet_email, -1);
665 cprintf("250 Sender ok <%s>\r\n", ChrPtr(sSMTP->from));
666 sSMTP->message_originated_locally = 1;
670 else if (sSMTP->is_lmtp) {
671 /* Bypass forgery checking for LMTP */
674 /* Otherwise, make sure outsiders aren't trying to forge mail from
675 * this system (unless, of course, c_allow_spoofing is enabled)
677 else if (CtdlGetConfigInt("c_allow_spoofing") == 0) {
678 process_rfc822_addr(ChrPtr(sSMTP->from), user, node, name);
679 syslog(LOG_DEBUG, "Claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
680 ChrPtr(sSMTP->from), user, node, name
682 if (CtdlHostAlias(node) != hostalias_nomatch) {
683 cprintf("550 You must log in to send mail from %s\r\n", node);
684 FlushStrBuf(sSMTP->from);
685 syslog(LOG_DEBUG, "Rejecting unauthenticated mail from %s", node);
690 cprintf("250 Sender ok\r\n");
696 * Implements the "RCPT To:" command
698 void smtp_rcpt(long offset, long flags)
700 struct CitContext *CCC = CC;
701 char message_to_spammer[SIZ];
702 recptypes *valid = NULL;
703 citsmtp *sSMTP = SMTP;
705 if (StrLength(sSMTP->from) == 0) {
706 cprintf("503 Need MAIL before RCPT\r\n");
710 if (strncasecmp(ChrPtr(sSMTP->Cmd) + offset, "To:", 3)) {
711 cprintf("501 Syntax error\r\n");
715 if ( (sSMTP->is_msa) && (!CCC->logged_in) ) {
716 cprintf("550 You must log in to send mail on this port.\r\n");
717 FlushStrBuf(sSMTP->from);
720 FlushStrBuf(sSMTP->OneRcpt);
721 StrBufAppendBuf(sSMTP->OneRcpt, sSMTP->Cmd, offset + 3);
722 StrBufTrim(sSMTP->OneRcpt);
723 StrBufStripAllBut(sSMTP->OneRcpt, '<', '>');
725 if ( (StrLength(sSMTP->OneRcpt) + StrLength(sSMTP->recipients)) >= SIZ) {
726 cprintf("452 Too many recipients\r\n");
731 if ( (!CCC->logged_in) /* Don't RBL authenticated users */
732 && (!sSMTP->is_lmtp) ) { /* Don't RBL LMTP clients */
733 if (CtdlGetConfigInt("c_rbl_at_greeting") == 0) { /* Don't RBL again if we already did it */
734 if (rbl_check(message_to_spammer)) {
735 if (server_shutting_down)
736 cprintf("421 %s\r\n", message_to_spammer);
738 cprintf("550 %s\r\n", message_to_spammer);
739 /* no need to free_recipients(valid), it's not allocated yet */
745 valid = validate_recipients(
746 ChrPtr(sSMTP->OneRcpt),
747 smtp_get_Recipients(),
748 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
750 if (valid->num_error != 0) {
751 cprintf("550 %s\r\n", valid->errormsg);
752 free_recipients(valid);
756 if (valid->num_internet > 0) {
757 if (CCC->logged_in) {
758 if (CtdlCheckInternetMailPermission(&CCC->user)==0) {
759 cprintf("551 <%s> - you do not have permission to send Internet mail\r\n",
760 ChrPtr(sSMTP->OneRcpt));
761 free_recipients(valid);
767 if (valid->num_internet > 0) {
768 if ( (sSMTP->message_originated_locally == 0)
769 && (sSMTP->is_lmtp == 0) ) {
770 cprintf("551 <%s> - relaying denied\r\n", ChrPtr(sSMTP->OneRcpt));
771 free_recipients(valid);
776 cprintf("250 RCPT ok <%s>\r\n", ChrPtr(sSMTP->OneRcpt));
777 if (StrLength(sSMTP->recipients) > 0) {
778 StrBufAppendBufPlain(sSMTP->recipients, HKEY(","), 0);
780 StrBufAppendBuf(sSMTP->recipients, sSMTP->OneRcpt, 0);
781 sSMTP->number_of_recipients ++;
783 free_recipients(valid);
791 * Implements the DATA command
793 void smtp_data(long offset, long flags)
795 struct CitContext *CCC = CC;
798 struct CtdlMessage *msg = NULL;
804 citsmtp *sSMTP = SMTP;
806 if (StrLength(sSMTP->from) == 0) {
807 cprintf("503 Need MAIL command first.\r\n");
811 if (sSMTP->number_of_recipients < 1) {
812 cprintf("503 Need RCPT command first.\r\n");
816 cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
818 datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
819 defbody = NewStrBufPlain(NULL, SIZ);
821 if (defbody != NULL) {
822 if (sSMTP->is_lmtp && (CCC->cs_UDSclientUID != -1)) {
825 "Received: from %s (Citadel from userid %ld)\n"
827 ChrPtr(sSMTP->helo_node),
828 (long int) CCC->cs_UDSclientUID,
829 CtdlGetConfigStr("c_fqdn"),
835 "Received: from %s (%s [%s])\n"
837 ChrPtr(sSMTP->helo_node),
840 CtdlGetConfigStr("c_fqdn"),
844 body = CtdlReadMessageBodyBuf(HKEY("."), CtdlGetConfigLong("c_maxmsglen"), defbody, 1, NULL);
845 FreeStrBuf(&defbody);
847 cprintf("550 Unable to save message: internal error.\r\n");
851 syslog(LOG_DEBUG, "Converting message...\n");
852 msg = convert_internet_message_buf(&body);
854 /* If the user is locally authenticated, FORCE the From: header to
855 * show up as the real sender. Yes, this violates the RFC standard,
856 * but IT MAKES SENSE. If you prefer strict RFC adherence over
857 * common sense, you can disable this in the configuration.
859 * We also set the "message room name" ('O' field) to MAILROOM
860 * (which is Mail> on most systems) to prevent it from getting set
861 * to something ugly like "0000058008.Sent Items>" when the message
862 * is read with a Citadel client.
864 if ( (CCC->logged_in) && (CtdlGetConfigInt("c_rfc822_strict_from") != CFG_SMTP_FROM_NOFILTER) ) {
867 if (!CM_IsEmpty(msg, erFc822Addr) &&
868 ((CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_CORRECT) ||
869 (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT) ) )
871 if (!IsEmptyStr(CCC->cs_inet_email))
872 validemail = strcmp(CCC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
874 (!IsEmptyStr(CCC->cs_inet_other_emails)))
876 int num_secondary_emails = 0;
878 num_secondary_emails = num_tokens(CCC->cs_inet_other_emails, '|');
879 for (i=0; i < num_secondary_emails && !validemail; ++i) {
881 extract_token(buf, CCC->cs_inet_other_emails,i,'|',sizeof CCC->cs_inet_other_emails);
882 validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
887 if (!validemail && (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT)) {
888 syslog(LOG_ERR, "invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
889 cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
893 CM_SetField(msg, eNodeName, CtdlGetConfigStr("c_nodename"), strlen(CtdlGetConfigStr("c_nodename")));
894 CM_SetField(msg, eHumanNode, CtdlGetConfigStr("c_humannode"), strlen(CtdlGetConfigStr("c_humannode")));
895 CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
896 if (sSMTP->preferred_sender_name != NULL)
897 CM_SetField(msg, eAuthor, SKEY(sSMTP->preferred_sender_name));
899 CM_SetField(msg, eAuthor, CCC->user.fullname, strlen(CCC->user.fullname));
902 if (sSMTP->preferred_sender_email != NULL)
903 CM_SetField(msg, erFc822Addr, SKEY(sSMTP->preferred_sender_email));
905 CM_SetField(msg, erFc822Addr, CCC->cs_inet_email, strlen(CCC->cs_inet_email));
909 /* Set the "envelope from" address */
910 CM_SetField(msg, eMessagePath, SKEY(sSMTP->from));
912 /* Set the "envelope to" address */
913 CM_SetField(msg, eenVelopeTo, SKEY(sSMTP->recipients));
915 /* Submit the message into the Citadel system. */
916 valid = validate_recipients(
917 ChrPtr(sSMTP->recipients),
918 smtp_get_Recipients(),
919 (sSMTP->is_lmtp)? POST_LMTP: (CCC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
922 /* If there are modules that want to scan this message before final
923 * submission (such as virus checkers or spam filters), call them now
924 * and give them an opportunity to reject the message.
926 if (sSMTP->is_unfiltered) {
930 scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
933 if (scan_errors > 0) { /* We don't want this message! */
935 if (CM_IsEmpty(msg, eErrorMsg)) {
936 CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
939 StrBufPrintf(sSMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
942 else { /* Ok, we'll accept this message. */
943 msgnum = CtdlSubmitMsg(msg, valid, "", 0);
945 StrBufPrintf(sSMTP->OneRcpt, "250 Message accepted.\r\n");
948 StrBufPrintf(sSMTP->OneRcpt, "550 Internal delivery error\r\n");
952 /* For SMTP and ESMTP, just print the result message. For LMTP, we
953 * have to print one result message for each recipient. Since there
954 * is nothing in Citadel which would cause different recipients to
955 * have different results, we can get away with just spitting out the
956 * same message once for each recipient.
958 if (sSMTP->is_lmtp) {
959 for (i=0; i<sSMTP->number_of_recipients; ++i) {
960 cputbuf(sSMTP->OneRcpt);
964 cputbuf(sSMTP->OneRcpt);
967 /* Write something to the syslog(which may or may not be where the
968 * rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
970 syslog((LOG_MAIL | LOG_INFO),
971 "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
974 sSMTP->number_of_recipients,
977 ChrPtr(sSMTP->OneRcpt)
982 free_recipients(valid);
983 smtp_data_clear(0, 0); /* clear out the buffers now */
988 * implements the STARTTLS command
990 void smtp_starttls(long offset, long flags)
992 char ok_response[SIZ];
993 char nosup_response[SIZ];
994 char error_response[SIZ];
996 sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
997 sprintf(nosup_response, "554 TLS not supported here\r\n");
998 sprintf(error_response, "554 Internal error\r\n");
999 CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
1005 * Main command loop for SMTP server sessions.
1007 void smtp_command_loop(void)
1009 static const ConstStr AuthPlainStr = {HKEY("AUTH PLAIN")};
1010 struct CitContext *CCC = CC;
1011 citsmtp *sSMTP = SMTP;
1012 const char *pch, *pchs;
1014 char CMD[MaxSMTPCmdLen + 1];
1016 if (sSMTP == NULL) {
1017 syslog(LOG_EMERG, "Session SMTP data is null. WTF? We will crash now.\n");
1018 return cit_panic_backtrace (0);
1021 time(&CCC->lastcmd);
1022 if (CtdlClientGetLine(sSMTP->Cmd) < 1) {
1023 syslog(LOG_CRIT, "SMTP: client disconnected: ending session.\n");
1024 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1027 syslog(LOG_DEBUG, "SMTP server: %s\n", ChrPtr(sSMTP->Cmd));
1029 if (sSMTP->command_state == smtp_user) {
1030 if (!strncmp(ChrPtr(sSMTP->Cmd), AuthPlainStr.Key, AuthPlainStr.len))
1031 smtp_try_plain(0, 0);
1037 else if (sSMTP->command_state == smtp_password) {
1038 smtp_get_pass(0, 0);
1042 else if (sSMTP->command_state == smtp_plain) {
1043 smtp_try_plain(0, 0);
1047 pchs = pch = ChrPtr(sSMTP->Cmd);
1049 while ((*pch != '\0') &&
1051 (pch - pchs <= MaxSMTPCmdLen))
1053 CMD[i] = toupper(*pch);
1059 if ((*pch == '\0') ||
1064 if (GetHash(SMTPCmds, CMD, i, &v) &&
1067 smtp_handler_hook *h = (smtp_handler_hook*) v;
1069 if (isblank(pchs[i]))
1077 cprintf("502 I'm afraid I can't do that.\r\n");
1080 void smtp_noop(long offest, long Flags)
1082 cprintf("250 NOOP\r\n");
1085 void smtp_quit(long offest, long Flags)
1087 cprintf("221 Goodbye...\r\n");
1088 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1091 /*****************************************************************************/
1092 /* MODULE INITIALIZATION STUFF */
1093 /*****************************************************************************/
1095 * This cleanup function blows away the temporary memory used by
1098 void smtp_cleanup_function(void)
1100 citsmtp *sSMTP = SMTP;
1102 /* Don't do this stuff if this is not an SMTP session! */
1103 if (CC->h_command_function != smtp_command_loop) return;
1105 syslog(LOG_DEBUG, "Performing SMTP cleanup hook\n");
1107 FreeStrBuf(&sSMTP->Cmd);
1108 FreeStrBuf(&sSMTP->helo_node);
1109 FreeStrBuf(&sSMTP->from);
1110 FreeStrBuf(&sSMTP->recipients);
1111 FreeStrBuf(&sSMTP->OneRcpt);
1112 FreeStrBuf(&sSMTP->preferred_sender_email);
1113 FreeStrBuf(&sSMTP->preferred_sender_name);
1118 const char *CitadelServiceSMTP_MTA="SMTP-MTA";
1119 const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
1120 const char *CitadelServiceSMTP_MSA="SMTP-MSA";
1121 const char *CitadelServiceSMTP_LMTP="LMTP";
1122 const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
1124 CTDL_MODULE_INIT(smtp)
1128 SMTPCmds = NewHash(1, NULL);
1130 RegisterSmtpCMD("AUTH", smtp_auth, 0);
1131 RegisterSmtpCMD("DATA", smtp_data, 0);
1132 RegisterSmtpCMD("HELO", smtp_hello, HELO);
1133 RegisterSmtpCMD("EHLO", smtp_hello, EHLO);
1134 RegisterSmtpCMD("LHLO", smtp_hello, LHLO);
1135 RegisterSmtpCMD("HELP", smtp_help, 0);
1136 RegisterSmtpCMD("MAIL", smtp_mail, 0);
1137 RegisterSmtpCMD("NOOP", smtp_noop, 0);
1138 RegisterSmtpCMD("QUIT", smtp_quit, 0);
1139 RegisterSmtpCMD("RCPT", smtp_rcpt, 0);
1140 RegisterSmtpCMD("RSET", smtp_rset, 1);
1142 RegisterSmtpCMD("STARTTLS", smtp_starttls, 0);
1146 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtp_port"), /* SMTP MTA */
1151 CitadelServiceSMTP_MTA);
1154 CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtps_port"), /* SMTPS MTA */
1159 CitadelServiceSMTPS_MTA);
1162 CtdlRegisterServiceHook(CtdlGetConfigInt("c_msa_port"), /* SMTP MSA */
1167 CitadelServiceSMTP_MSA);
1169 CtdlRegisterServiceHook(0, /* local LMTP */
1174 CitadelServiceSMTP_LMTP);
1176 CtdlRegisterServiceHook(0, /* local LMTP */
1177 file_lmtp_unfiltered_socket,
1178 lmtp_unfiltered_greeting,
1181 CitadelServiceSMTP_LMTP_UNF);
1183 CtdlRegisterCleanupHook(smtp_cleanup);
1184 CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
1187 /* return our module name for the log */