2 * Utility functions for the Citadel SMTP implementation
4 * Copyright (c) 1998-2020 by the citadel.org team
6 * This program is open source software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 3.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
24 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34 #include <libcitadel.h>
37 #include "citserver.h"
44 #include "internet_addressing.h"
47 #include "clientsocket.h"
48 #include "locate_host.h"
49 #include "citadel_dirs.h"
50 #include "ctdl_module.h"
51 #include "smtp_util.h"
53 const char *smtp_get_Recipients(void)
55 citsmtp *sSMTP = SMTP;
59 else return ChrPtr(sSMTP->from);
64 * smtp_do_bounce() is caled by smtp_process_one_msg() to scan a set of delivery
65 * instructions for errors and produce/deliver a "bounce" message (delivery
66 * status notification).
68 * is_final should be set to:
69 * SDB_BOUNCE_FATALS Advise the sender of all 5XX (permanent failures)
70 * SDB_BOUNCE_ALL Advise the sender that all deliveries have failed and will not be retried
71 * SDB_WARN Warn the sender about all 4XX transient delays
73 void smtp_do_bounce(const char *instr, int is_final)
86 struct CtdlMessage *bmsg = NULL;
87 struct recptypes *valid;
88 int successful_bounce = 0;
93 syslog(LOG_DEBUG, "smtp_do_bounce() called");
95 boundary = NewStrBufPlain(HKEY("=_Citadel_Multipart_"));
97 StrBufAppendPrintf(boundary, "%s_%04x%04x", CtdlGetConfigStr("c_fqdn"), getpid(), ++seq);
100 /* Start building our bounce message */
102 bmsg = (struct CtdlMessage *) malloc(sizeof(struct CtdlMessage));
103 if (bmsg == NULL) return;
104 memset(bmsg, 0, sizeof(struct CtdlMessage));
105 BounceMB = NewStrBufPlain(NULL, 1024);
107 bmsg->cm_magic = CTDLMESSAGE_MAGIC;
108 bmsg->cm_anon_type = MES_NORMAL;
109 bmsg->cm_format_type = FMT_RFC822;
110 CM_SetField(bmsg, eAuthor, HKEY("Citadel"));
111 CM_SetField(bmsg, eOriginalRoom, HKEY(MAILROOM));
112 CM_SetField(bmsg, eMsgSubject, HKEY("Delivery Status Notification (Failure)"));
113 StrBufAppendBufPlain(BounceMB, HKEY("Content-type: multipart/mixed; boundary=\""), 0);
114 StrBufAppendBuf(BounceMB, boundary, 0);
115 StrBufAppendBufPlain(BounceMB, HKEY("\"\r\n"), 0);
116 StrBufAppendBufPlain(BounceMB, HKEY("MIME-Version: 1.0\r\n"), 0);
117 StrBufAppendBufPlain(BounceMB, HKEY("X-Mailer: " CITADEL "\r\n"), 0);
118 StrBufAppendBufPlain(BounceMB, HKEY("\r\nThis is a multipart message in MIME format.\r\n\r\n"), 0);
119 StrBufAppendBufPlain(BounceMB, HKEY("--"), 0);
120 StrBufAppendBuf(BounceMB, boundary, 0);
121 StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
122 StrBufAppendBufPlain(BounceMB, HKEY("Content-type: text/plain\r\n\r\n"), 0);
124 if (is_final == SDB_BOUNCE_ALL)
126 StrBufAppendBufPlain(
128 HKEY( "A message you sent could not be delivered "
129 "to some or all of its recipients\ndue to "
130 "prolonged unavailability of its destination(s).\n"
131 "Giving up on the following addresses:\n\n"),
134 else if (is_final == SDB_BOUNCE_FATALS)
136 StrBufAppendBufPlain(
138 HKEY( "A message you sent could not be delivered "
139 "to some or all of its recipients.\n"
140 "The following addresses were undeliverable:\n\n"),
143 else if (is_final == SDB_WARN)
145 StrBufAppendBufPlain(
147 HKEY("A message you sent has not been delivered "
148 "to some or all of its recipients.\n"
149 "Citadel will continue attempting delivery for five days.\n"
150 "The following addresses were undeliverable:\n\n"),
153 else // should never get here
155 StrBufAppendBufPlain(BounceMB, HKEY("This message should never occur.\n\n"), 0);
159 * Now go through the instructions checking for stuff.
161 lines = num_tokens(instr, '\n');
162 for (i=0; i<lines; ++i) {
165 extract_token(buf, instr, i, '\n', sizeof buf);
166 extract_token(key, buf, 0, '|', sizeof key);
167 addrlen = extract_token(addr, buf, 1, '|', sizeof addr);
168 status = extract_int(buf, 2);
169 dsnlen = extract_token(dsn, buf, 3, '|', sizeof dsn);
172 syslog(LOG_DEBUG, "key=<%s> addr=<%s> status=%d dsn=<%s>", key, addr, status, dsn);
174 if (!strcasecmp(key, "bounceto")) {
175 strcpy(bounceto, addr);
178 if (!strcasecmp(key, "msgid")) {
182 if (!strcasecmp(key, "remote")) {
183 if ((is_final == SDB_BOUNCE_FATALS) && (status == 5)) bounce_this = 1;
184 if ((is_final == SDB_BOUNCE_ALL) && (status != 2)) bounce_this = 1;
185 if ((is_final == SDB_WARN) && (status == 4)) bounce_this = 1;
190 StrBufAppendBufPlain(BounceMB, addr, addrlen, 0);
191 StrBufAppendBufPlain(BounceMB, HKEY(": "), 0);
192 StrBufAppendBufPlain(BounceMB, dsn, dsnlen, 0);
193 StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
197 /* Attach the original message */
199 StrBufAppendBufPlain(BounceMB, HKEY("--"), 0);
200 StrBufAppendBuf(BounceMB, boundary, 0);
201 StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
202 StrBufAppendBufPlain(BounceMB, HKEY("Content-type: message/rfc822\r\n"), 0);
203 StrBufAppendBufPlain(BounceMB, HKEY("Content-Transfer-Encoding: 7bit\r\n"), 0);
204 StrBufAppendBufPlain(BounceMB, HKEY("Content-Disposition: inline\r\n"), 0);
205 StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
207 CC->redirect_buffer = NewStrBufPlain(NULL, SIZ);
208 CtdlOutputMsg(omsgid,
214 StrBufAppendBuf(BounceMB, CC->redirect_buffer, 0);
215 FreeStrBuf(&CC->redirect_buffer);
218 /* Close the multipart MIME scope */
219 StrBufAppendBufPlain(BounceMB, HKEY("--"), 0);
220 StrBufAppendBuf(BounceMB, boundary, 0);
221 StrBufAppendBufPlain(BounceMB, HKEY("--\r\n"), 0);
222 CM_SetAsFieldSB(bmsg, eMesageText, &BounceMB);
224 /* Deliver the bounce if there's anything worth mentioning */
225 syslog(LOG_DEBUG, "num_bounces = %d", num_bounces);
226 if (num_bounces > 0) {
228 /* First try the user who sent the message */
229 if (IsEmptyStr(bounceto)) {
230 syslog(LOG_ERR, "No bounce address specified");
233 syslog(LOG_DEBUG, "bounce to user <%s>", bounceto);
235 /* Can we deliver the bounce to the original sender? */
236 valid = validate_recipients(bounceto, smtp_get_Recipients (), 0);
238 if (valid->num_error == 0) {
239 CtdlSubmitMsg(bmsg, valid, "");
240 successful_bounce = 1;
244 /* If not, post it in the Aide> room */
245 if (successful_bounce == 0) {
246 CtdlSubmitMsg(bmsg, NULL, CtdlGetConfigStr("c_aideroom"));
249 /* Free up the memory we used */
251 free_recipients(valid);
254 FreeStrBuf(&boundary);
256 syslog(LOG_DEBUG, "Done processing bounces");
263 char *smtpcodes[][2] = {
264 { "211 - System status / system help reply" },
265 { "214", "Help message" },
266 { "220", "Domain service ready" },
267 { "221", "Domain service closing transmission channel" },
268 { "250", "Requested mail action completed and OK" },
269 { "251", "Not Local User, forward email to forward path" },
270 { "252", "Cannot Verify user, will attempt delivery later" },
271 { "253", "Pending messages for node started" },
272 { "354", "Start mail input; end with ." },
273 { "355", "Octet-offset is the transaction offset" },
274 { "421", "Domain service not available, closing transmission channel" },
275 { "432", "Domain service not available, closing transmission channel" },
276 { "450", "Requested mail action not taken: mailbox unavailable. request refused" },
277 { "451", "Requested action aborted: local error in processing Request is unable to be processed, try again" },
278 { "452", "Requested action not taken: insufficient system storage" },
279 { "453", "No mail" },
280 { "454", "TLS not available due to temporary reason. Encryption required for requested authentication mechanism" },
281 { "458", "Unable to queue messages for node" },
282 { "459", "Node not allowed: reason" },
283 { "500", "Syntax error, command unrecognized" },
284 { "501", "Syntax error in parameters or arguments" },
285 { "502", "Command not implemented" },
286 { "503", "Bad sequence of commands" },
287 { "504", "Command parameter not implemented" },
288 { "510", "Check the recipient address" },
289 { "512", "Domain can not be found. Unknown host." },
290 { "515", "Destination mailbox address invalid" },
291 { "517", "Problem with senders mail attribute, check properties" },
292 { "521", "Domain does not accept mail" },
293 { "522", "Recipient has exceeded mailbox limit" },
294 { "523", "Server limit exceeded. Message too large" },
295 { "530", "Access Denied. Authentication required" },
296 { "531", "Mail system Full" },
297 { "533", "Remote server has insufficient disk space to hold email" },
298 { "534", "Authentication mechanism is too weak. Message too big" },
299 { "535", "Multiple servers using same IP. Required Authentication" },
300 { "538", "Encryption required for requested authentication mechanism" },
301 { "540", "Email address has no DNS Server" },
302 { "541", "No response from host" },
303 { "542", "Bad Connection" },
304 { "543", "Routing server failure. No available route" },
305 { "546", "Email looping" },
306 { "547", "Delivery time-out" },
307 { "550", "Requested action not taken: mailbox unavailable or relaying denied" },
308 { "551", "User not local; please try forward path" },
309 { "552", "Requested mail action aborted: exceeded storage allocation" },
310 { "553", "Requested action not taken: mailbox name not allowed" },
311 { "554", "Transaction failed" }
316 char *smtpstatus(int code) {
319 for (i=0; i<(sizeof(smtpcodes)/sizeof(char *)/2); ++i) {
320 if (atoi(smtpcodes[i][0]) == code) {
321 return(smtpcodes[i][1]);
325 return("Unknown or other SMTP status");