2 * sink.c -- forwarding/delivery support for fetchmail
4 * The interface of this module (open_sink(), stuff_line(), close_sink(),
5 * release_sink()) seals off the delivery logic from the protocol machine,
6 * so the latter won't have to care whether it's shipping to an [SL]MTP
7 * listener daemon or an MDA pipe.
9 * Copyright 1998 by Eric S. Raymond
10 * For license terms, see the file COPYING in this directory.
20 #endif /* HAVE_MEMORY_H */
21 #if defined(STDC_HEADERS)
24 #if defined(HAVE_UNISTD_H)
27 #if defined(HAVE_STDARG_H)
34 /* for W* macros after pclose() */
36 #include <sys/types.h>
37 #include <sys/resource.h>
41 #include "fetchmail.h"
46 /* BSD portability hack...I know, this is an ugly place to put it */
47 #if !defined(SIGCHLD) && defined(SIGCLD)
48 #define SIGCHLD SIGCLD
51 /* makes the open_sink()/close_sink() pair non-reentrant */
52 static int lmtp_responses;
54 void smtp_close(struct query *ctl, int sayquit)
55 /* close the socket to SMTP server */
57 if (ctl->smtp_socket != -1)
60 SMTP_quit(ctl->smtp_socket);
61 SockClose(ctl->smtp_socket);
62 ctl->smtp_socket = -1;
67 int smtp_open(struct query *ctl)
68 /* try to open a socket to the appropriate SMTP server for this query */
70 char *parsed_host = NULL;
72 /* maybe it's time to close the socket in order to force delivery */
73 if (last_smtp_ok > 0 && time((time_t *)NULL) - last_smtp_ok > mytimeout)
78 if (NUM_NONZERO(ctl->batchlimit)) {
79 if (batchcount == ctl->batchlimit)
84 /* if no socket to any SMTP host is already set up, try to open one */
85 if (ctl->smtp_socket == -1)
88 * RFC 1123 requires that the domain name in HELO address is a
89 * "valid principal domain name" for the client host. If we're
90 * running in invisible mode, violate this with malice
91 * aforethought in order to make the Received headers and
94 * In fact this code relies on the RFC1123 requirement that the
95 * SMTP listener must accept messages even if verification of the
96 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
98 * How we compute the true mailhost name to pass to the
99 * listener doesn't affect behavior on RFC1123-violating
100 * listeners that check for name match; we're going to lose
101 * on those anyway because we can never give them a name
102 * that matches the local machine fetchmail is running on.
103 * What it will affect is the listener's logging.
106 const char *id_me = run.invisible ? ctl->server.truename : fetchmailhost;
107 int oldphase = phase;
112 * Run down the SMTP hunt list looking for a server that's up.
113 * Use both explicit hunt entries (value TRUE) and implicit
114 * (default) ones (value FALSE).
117 phase = LISTENER_WAIT;
119 set_timeout(ctl->server.timeout);
120 for (idp = ctl->smtphunt; idp; idp = idp->next)
124 char *portnum = SMTP_PORT;
126 int portnum = SMTP_PORT;
127 #endif /* INET6_ENABLE */
129 xalloca(parsed_host, char *, strlen(idp->id) + 1);
131 ctl->smtphost = idp->id; /* remember last host tried. */
132 if(ctl->smtphost[0]=='/')
133 ctl->listener = LMTP_MODE;
135 strcpy(parsed_host, idp->id);
136 if ((cp = strrchr(parsed_host, '/')))
143 #endif /* INET6_ENABLE */
146 if (ctl->smtphost[0]=='/'){
147 if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1)
150 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
151 ctl->server.plugout)) == -1)
154 /* return immediately for ODMR */
155 if (ctl->server.protocol == P_ODMR)
159 return(ctl->smtp_socket); /* success */
162 /* are we doing SMTP or LMTP? */
163 SMTP_setmode(ctl->listener);
165 /* first, probe for ESMTP */
166 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
167 SMTP_ehlo(ctl->smtp_socket, id_me,
168 ctl->server.esmtp_name, ctl->server.esmtp_password,
169 &ctl->server.esmtp_options) == SM_OK)
173 * RFC 1869 warns that some listeners hang up on a failed EHLO,
174 * so it's safest not to assume the socket will still be good.
178 /* if opening for ESMTP failed, try SMTP */
179 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
180 ctl->server.plugout)) == -1)
183 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
184 SMTP_helo(ctl->smtp_socket, id_me) == SM_OK)
194 * RFC 1123 requires that the domain name part of the
195 * RCPT TO address be "canonicalized", that is a FQDN
196 * or MX but not a CNAME. Some listeners (like exim)
197 * enforce this. Now that we have the actual hostname,
198 * compute what we should canonicalize with.
200 * make sure we do not forget to drop the /port if
203 if (ctl->listener == LMTP_MODE && !ctl->smtpaddress)
205 if (parsed_host && parsed_host[0] != 0)
206 ctl->destaddr = xstrdup(parsed_host);
208 ctl->destaddr = (ctl->smtphost && ctl->smtphost[0] != '/') ? ctl->smtphost : "localhost";
213 * Here we try to find a correct domain name part for the RCPT
214 * TO address. If smtpaddress is set, no need to guestimate
215 * it. Otherwise, using ctl->smtphost as a base is a good
216 * base, although we may have to strip any port appended to
217 * communicate with SMTP servers that do not listen on the
218 * SMTP port. (benj) */
219 if (ctl->smtpaddress)
220 ctl->destaddr = ctl->smtpaddress;
221 else if (ctl->smtphost && ctl->smtphost[0] != '/')
224 if ((cp = strchr (ctl->smtphost, '/')))
226 /* As an alternate port for smtphost is specified, we
227 need to strip it from domain name. */
229 xalloca(smtpname, char *, cp - ctl->smtphost + 1);
230 strncpy(smtpname, ctl->smtphost, cp - ctl->smtphost +1);
231 cp = strchr(smtpname, '/');
233 ctl->destaddr = smtpname;
236 /* No need to strip port, domain name is smtphost. */
237 ctl->destaddr = ctl->smtphost;
239 /* No smtphost is specified or it is a UNIX socket, then use
240 localhost as a domain part. */
242 ctl->destaddr = "localhost";
245 if (outlevel >= O_DEBUG && ctl->smtp_socket != -1)
246 report(stdout, GT_("forwarding to %s\n"), ctl->smtphost);
248 return(ctl->smtp_socket);
251 static void sanitize(char *s)
256 for (cp = s; (cp = strchr (cp, '\'')); cp++)
260 char *rcpt_address(struct query *ctl, const char *id,
263 static char addr[HOSTLEN+USERNAMELEN+1];
267 snprintf(addr, sizeof (addr), "%s", id);
269 sprintf(addr, "%s", id);
270 #endif /* HAVE_SNPRINTF */
272 else if (usesmtpname && ctl->smtpname)
275 snprintf(addr, sizeof (addr), "%s", ctl->smtpname);
277 sprintf(addr, "%s", ctl->smtpname);
278 #endif /* HAVE_SNPRINTF */
283 snprintf(addr, sizeof (addr), "%s@%s", id, ctl->destaddr);
285 sprintf(addr, "%s@%s", id, ctl->destaddr);
286 #endif /* HAVE_SNPRINTF */
291 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
292 int userclass, char *message,
293 int nerrors, char *errors[])
294 /* bounce back an error report a la RFC 1892 */
296 char daemon_name[15 + HOSTLEN] = "MAILER-DAEMON@";
297 char boundary[BUFSIZ], *bounce_to;
299 static char *fqdn_of_host = NULL;
300 const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@";
302 /* don't bounce in reply to undeliverable bounces */
303 if (!msg->return_path[0] ||
304 strcmp(msg->return_path, "<>") == 0 ||
305 strcasecmp(msg->return_path, md1) == 0 ||
306 strncasecmp(msg->return_path, md2, strlen(md2)) == 0)
309 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
311 SMTP_setmode(SMTP_MODE);
313 /* can't just use fetchmailhost here, it might be localhost */
314 if (fqdn_of_host == NULL)
315 fqdn_of_host = host_fqdn();
316 strcat(daemon_name, fqdn_of_host);
318 /* we need only SMTP for this purpose */
319 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, NULL)) == -1)
322 if (SMTP_ok(sock) != SM_OK)
328 if (SMTP_helo(sock, fetchmailhost) != SM_OK
329 || SMTP_from(sock, "<>", (char *)NULL) != SM_OK
330 || SMTP_rcpt(sock, bounce_to) != SM_OK
331 || SMTP_data(sock) != SM_OK)
338 /* our first duty is to keep the sacred foo counters turning... */
340 snprintf(boundary, sizeof(boundary),
343 #endif /* HAVE_SNPRINTF */
344 "foo-mani-padme-hum-%d-%d-%ld",
345 (int)getpid(), (int)getppid(), time((time_t *)NULL));
347 if (outlevel >= O_VERBOSE)
348 report(stdout, GT_("SMTP: (bounce-message body)\n"));
350 /* this will usually go to sylog... */
351 report(stderr, GT_("mail from %s bounced to %s\n"),
352 daemon_name, bounce_to);
355 /* bouncemail headers */
356 SockPrintf(sock, "Subject: Mail delivery failed: returning message to sender\r\n");
357 SockPrintf(sock, "From: Mail Delivery System <%s>\r\n", daemon_name);
358 SockPrintf(sock, "To: %s\r\n", bounce_to);
359 SockPrintf(sock, "MIME-Version: 1.0\r\n");
360 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
361 SockPrintf(sock, "\r\n");
363 /* RFC1892 part 1 -- human-readable message */
364 SockPrintf(sock, "--%s\r\n", boundary);
365 SockPrintf(sock,"Content-Type: text/plain\r\n");
366 SockPrintf(sock, "\r\n");
367 SockPrintf(sock, "This message was created automatically by mail delivery software.\r\n\r\n");
368 SockPrintf(sock, "A message that you sent could not be delivered to one or more of its\r\n");
369 SockPrintf(sock, "recipients. This is a permanent error. The following address(es) failed:\r\n");
370 SockPrintf(sock, "\r\n");
378 for (idp = msg->recipients; idp; idp = idp->next)
380 if (idp->val.status.mark == userclass)
383 SockPrintf(sock, "%s\r\n", rcpt_address (ctl, idp->id, 1));
385 if (nerrors == 1) error = errors[0];
386 else if (nerrors <= nusers)
388 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
391 else error = errors[nusers++];
393 SockPrintf(sock, " SMTP error: %s\r\n\r\n", error);
397 /* RFC1892 part 2 -- machine-readable responses */
398 SockPrintf(sock, "--%s\r\n", boundary);
399 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
400 SockPrintf(sock, "\r\n");
401 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fqdn_of_host);
404 for (idp = msg->recipients; idp; idp = idp->next)
405 if (idp->val.status.mark == userclass)
408 /* Minimum RFC1894 compliance + Diagnostic-Code field */
409 SockPrintf(sock, "\r\n");
410 SockPrintf(sock, "Final-Recipient: rfc822; %s\r\n",
411 rcpt_address (ctl, idp->id, 1));
412 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
413 SockPrintf(sock, "Action: failed\r\n");
416 /* one error applies to all users */
418 else if (nerrors <= nusers)
420 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
424 /* errors correspond 1-1 to selected users */
425 error = errors[nusers++];
427 if (strlen(error) > 9 && isdigit((unsigned char)error[4])
428 && error[5] == '.' && isdigit((unsigned char)error[6])
429 && error[7] == '.' && isdigit((unsigned char)error[8]))
430 /* Enhanced status code available, use it */
431 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
433 /* Enhanced status code not available, fake one */
434 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
435 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
437 SockPrintf(sock, "\r\n");
440 /* RFC1892 part 3 -- headers of undelivered message */
441 SockPrintf(sock, "--%s\r\n", boundary);
442 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
443 SockPrintf(sock, "\r\n");
446 SockWrite(sock, msg->headers, strlen(msg->headers));
447 SockPrintf(sock, "\r\n");
449 SockPrintf(sock, "--%s--\r\n", boundary);
451 if (SMTP_eom(sock) != SM_OK || SMTP_quit(sock))
462 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
463 /* handle SMTP errors based on the content of SMTP_response */
464 /* return of PS_REFUSED deletes mail from the server; PS_TRANSIENT keeps it */
466 int smtperr = atoi(smtp_response);
471 xalloca(responses[0], char *, strlen(smtp_response)+1);
472 strcpy(responses[0], smtp_response);
476 * Don't do this! It can really mess you up if, for example, you're
477 * reporting an error with a single RCPT TO address among several;
478 * RSET discards the message body and it doesn't get sent to the
481 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
482 if (outlevel >= O_DEBUG)
483 report(stdout, GT_("Saved error is still %d\n"), smtperr);
484 #endif /* __UNUSED */
487 * Note: send_bouncemail message strings are not made subject
488 * to gettext translation because (a) they're going to be
489 * embedded in a text/plain 7bit part, and (b) they're
490 * going to be associated with listener error-response
491 * messages, which are probably in English (none of the
492 * MTAs I know about are internationalized).
494 for( walk = ctl->antispam; walk; walk = walk->next )
495 if ( walk->val.status.num == smtperr )
501 /* if (str_find(&ctl->antispam, smtperr)) */
505 * SMTP listener explicitly refuses to deliver mail
506 * coming from this address, probably due to an
507 * anti-spam domain exclusion. Respect this. Don't
508 * try to ship the message, and don't prevent it from
509 * being deleted. There's no point in bouncing the
510 * email either since most spammers don't put their
511 * real return email address anywhere in the headers
512 * (unless the user insists with the SET SPAMBOUNCE
517 * 571 = sendmail's "unsolicited email refused"
518 * 550 = exim's new antispam response (temporary)
519 * 501 = exim's old antispam response
520 * 554 = Postfix antispam response.
527 snprintf(rejmsg, sizeof(rejmsg),
530 #endif /* HAVE_SNPRINTF */
531 "spam filter or virus scanner rejected message because:\r\n"
532 "%s\r\n", responses[0]);
534 send_bouncemail(ctl, msg, XMIT_ACCEPT,
535 rejmsg, 1, responses);
541 * Suppress error message only if the response specifically
542 * meant `excluded for policy reasons'. We *should* see
543 * an error when the return code is less specific.
546 report(stderr, GT_("%cMTP error: %s\n"),
552 case 552: /* message exceeds fixed maximum message size */
554 * Permanent no-go condition on the
555 * ESMTP server. Don't try to ship the message,
556 * and allow it to be deleted.
559 send_bouncemail(ctl, msg, XMIT_ACCEPT,
560 "This message was too large (SMTP error 552).\r\n",
564 case 553: /* invalid sending domain */
566 * These latter days 553 usually means a spammer is trying to
567 * cover his tracks. We never bouncemail on these, because
568 * (a) the return address is invalid by definition, and
569 * (b) we wouldn't want spammers to get confirmation that
570 * this address is live, anyway.
572 #ifdef __DONT_FEED_THE_SPAMMERS__
574 send_bouncemail(ctl, msg, XMIT_ACCEPT,
575 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
577 #endif /* __DONT_FEED_THE_SPAMMERS__ */
581 /* bounce non-transient errors back to the sender */
582 if (smtperr >= 500 && smtperr <= 599)
584 send_bouncemail(ctl, msg, XMIT_ACCEPT,
585 "General SMTP/ESMTP error.\r\n",
590 * We're going to end up here on 4xx errors, like:
592 * 451: temporarily unable to identify sender (exim)
593 * 452: temporary out-of-queue-space condition on the ESMTP server.
595 * These are temporary errors. Don't try to ship the message,
596 * and suppress deletion so it can be retried on a future
599 * Bouncemail *might* be appropriate here as a delay
600 * notification (note; if we ever add this, we must make
601 * sure the RFC1894 Action field is "delayed" rather than
602 * "failed"). But it's not really necessary because
603 * these are not actual failures, we're very likely to be
604 * able to recover on the next cycle.
606 return(PS_TRANSIENT);
610 static int handle_smtp_report_without_bounce(struct query *ctl, struct msgblk *msg)
611 /* handle SMTP errors based on the content of SMTP_response */
612 /* atleast one PS_TRANSIENT: do not send the bounce mail, keep the mail;
613 * no PS_TRANSIENT, atleast one PS_SUCCESS: send the bounce mail, delete the mail;
614 * no PS_TRANSIENT, no PS_SUCCESS: do not send the bounce mail, delete the mail */
616 int smtperr = atoi(smtp_response);
618 if (str_find(&ctl->antispam, smtperr))
626 report(stderr, GT_("%cMTP error: %s\n"),
632 case 552: /* message exceeds fixed maximum message size */
637 case 553: /* invalid sending domain */
638 #ifdef __DONT_FEED_THE_SPAMMERS__
641 #endif /* __DONT_FEED_THE_SPAMMERS__ */
645 /* bounce non-transient errors back to the sender */
646 if (smtperr >= 500 && smtperr <= 599)
648 return(PS_TRANSIENT);
652 /* these are shared by open_sink and stuffline */
655 int stuffline(struct query *ctl, char *buf)
656 /* ship a line to the given control block's output sink (SMTP server or MDA) */
661 /* The line may contain NUL characters. Find the last char to use
662 * -- the real line termination is the sequence "\n\0".
664 last = buf + 1; /* last[-1] must be valid! */
665 while ((last += strlen(last)) && (last[-1] != '\n'))
668 /* fix message lines that have only \n termination (for qmail) */
671 if (last - 1 == buf || last[-2] != '\r')
680 phase = FORWARDING_WAIT;
683 * SMTP byte-stuffing. We only do this if the protocol does *not*
684 * use .<CR><LF> as EOM. If it does, the server will already have
685 * decorated any . lines it sends back up.
689 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
694 /* writing to SMTP, leave the byte-stuffing in place */;
697 else /* if (!protocol->delimited) -- not byte-stuffed already */
699 if (!ctl->mda) /* byte-stuff it */
702 SockWrite(ctl->smtp_socket, buf, 1);
705 fwrite(buf, 1, 1, sinkfp);
711 /* we may need to strip carriage returns */
716 for (sp = tp = buf; sp < last; sp++)
724 if (ctl->mda || ctl->bsmtp)
725 n = fwrite(buf, last - buf, 1, sinkfp);
726 else if (ctl->smtp_socket != -1)
727 n = SockWrite(ctl->smtp_socket, buf, last - buf);
734 static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg,
735 int *good_addresses, int *bad_addresses)
736 /* open a BSMTP stream */
740 if (strcmp(ctl->bsmtp, "-") == 0)
743 sinkfp = fopen(ctl->bsmtp, "a");
745 /* see the ap computation under the SMTP branch */
747 "MAIL FROM:%s", (msg->return_path[0]) ? msg->return_path : user);
749 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
750 fputs(" BODY=8BITMIME", sinkfp);
751 else if (ctl->mimemsg & MSG_IS_7BIT)
752 fputs(" BODY=7BIT", sinkfp);
754 /* exim's BSMTP processor does not handle SIZE */
755 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
757 fprintf(sinkfp, "\r\n");
760 * RFC 1123 requires that the domain name part of the
761 * RCPT TO address be "canonicalized", that is a FQDN
762 * or MX but not a CNAME. Some listeners (like exim)
763 * enforce this. Now that we have the actual hostname,
764 * compute what we should canonicalize with.
766 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : "localhost";
769 for (idp = msg->recipients; idp; idp = idp->next)
770 if (idp->val.status.mark == XMIT_ACCEPT)
772 fprintf(sinkfp, "RCPT TO: %s\r\n",
773 rcpt_address (ctl, idp->id, 1));
777 fputs("DATA\r\n", sinkfp);
781 report(stderr, GT_("BSMTP file open or preamble write failed\n"));
788 /* this is experimental and will be removed if double bounces are reported */
789 #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS
792 static const char *is_quad(const char *q)
793 /* Check if the string passed in points to what could be one quad of a
794 * dotted-quad IP address. Requirements are that the string is not a
795 * NULL pointer, begins with a period (which is skipped) or a digit
796 * and ends with a period or a NULL. If these requirements are met, a
797 * pointer to the last character (the period or the NULL character) is
798 * returned; otherwise NULL.
807 for(r=q;isdigit((unsigned char)*r);r++)
809 if ( ((*r) && (*r != '.')) || ((r-q) < 1) || ((r-q)>3) )
811 /* Make sure quad is < 255 */
820 else if (*(q+1) == '5')
830 static int is_dottedquad(const char *hostname)
831 /* Returns a true value if the passed in string looks like an IP
832 * address in dotted-quad form, and a false value otherwise.
836 return ((hostname=is_quad(is_quad(is_quad(is_quad(hostname))))) != NULL) &&
840 static int open_smtp_sink(struct query *ctl, struct msgblk *msg,
841 int *good_addresses, int *bad_addresses)
842 /* open an SMTP stream */
846 char options[MSGBUFSIZE];
847 char addr[HOSTLEN+USERNAMELEN+1];
848 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
849 char **from_responses;
850 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
852 int force_transient_error = 0;
856 * Compute ESMTP options.
859 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
860 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
861 strcpy(options, " BODY=8BITMIME");
862 else if (ctl->mimemsg & MSG_IS_7BIT)
863 strcpy(options, " BODY=7BIT");
866 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
867 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
870 * Try to get the SMTP listener to take the Return-Path
871 * address as MAIL FROM. If it won't, fall back on the
872 * remotename and mailserver host. This won't affect replies,
873 * which use the header From address anyway; the MAIL FROM
874 * address is a place for the SMTP listener to send
875 * bouncemail. The point is to guarantee a FQDN in the MAIL
876 * FROM line -- some SMTP listeners, like smail, become
879 * RFC 1123 requires that the domain name part of the
880 * MAIL FROM address be "canonicalized", that is a
881 * FQDN or MX but not a CNAME. We'll assume the Return-Path
882 * header is already in this form here (it certainly
883 * is if rewrite is on). RFC 1123 is silent on whether
884 * a nonexistent hostname part is considered canonical.
886 * This is a potential problem if the MTAs further upstream
887 * didn't pass canonicalized From/Return-Path lines, *and* the
888 * local SMTP listener insists on them.
890 * Handle the case where an upstream MTA is setting a return
891 * path equal to "@". Ghod knows why anyone does this, but
892 * it's been reported to happen in mail from Amazon.com and
895 * Also, if the hostname is a dotted quad, wrap it in square brackets.
896 * Apparently this is required by RFC2821, section 4.1.3.
898 if (!msg->return_path[0] || (msg->return_path[0] == '@'))
900 if (is_dottedquad(ctl->server.truename))
903 snprintf(addr, sizeof(addr),
906 #endif /* HAVE_SNPRINTF */
907 "%s@[%s]", ctl->remotename, ctl->server.truename);
912 snprintf(addr, sizeof(addr),
915 #endif /* HAVE_SNPRINTF */
916 "%s@%s", ctl->remotename, ctl->server.truename);
920 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
921 ap = msg->return_path;
922 /* in case Return-Path was "<>" we want to preserve that */
923 else if (strcmp(msg->return_path,"<>") == 0)
924 ap = msg->return_path;
925 else /* in case Return-Path existed but was local */
927 if (is_dottedquad(ctl->server.truename))
930 snprintf(addr, sizeof(addr),
933 #endif /* HAVE_SNPRINTF */
934 "%s@[%s]", msg->return_path, ctl->server.truename);
939 snprintf(addr, sizeof(addr),
942 #endif /* HAVE_SNPRINTF */
943 "%s@%s", msg->return_path, ctl->server.truename);
948 if ((smtp_err = SMTP_from(ctl->smtp_socket, ap, options)) == SM_UNRECOVERABLE)
951 return(PS_TRANSIENT);
953 if (smtp_err != SM_OK)
955 int err = handle_smtp_report(ctl, msg);
957 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
962 * Now list the recipient addressees
965 for (idp = msg->recipients; idp; idp = idp->next)
967 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
968 xalloca(from_responses, char **, sizeof(char *) * total_addresses);
969 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
970 for (idp = msg->recipients; idp; idp = idp->next)
971 if (idp->val.status.mark == XMIT_ACCEPT)
974 address = rcpt_address (ctl, idp->id, 1);
975 if ((smtp_err = SMTP_rcpt(ctl->smtp_socket, address)) == SM_UNRECOVERABLE)
978 return(PS_TRANSIENT);
980 if (smtp_err == SM_OK)
984 switch (handle_smtp_report_without_bounce(ctl, msg))
987 force_transient_error = 1;
991 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
992 xalloca(from_responses[*bad_addresses],
994 strlen(smtp_response)+1);
995 strcpy(from_responses[*bad_addresses], smtp_response);
996 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
999 idp->val.status.mark = XMIT_RCPTBAD;
1000 if (outlevel >= O_VERBOSE)
1002 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
1003 ctl->listener, address);
1007 if (outlevel >= O_VERBOSE)
1009 GT_("%cMTP listener doesn't really like recipient address `%s'\n"),
1010 ctl->listener, address);
1016 if (force_transient_error) {
1017 /* do not risk dataloss due to overengineered multidrop
1018 * crap. If one of the recipients returned PS_TRANSIENT,
1019 * we return exactly that.
1021 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
1022 return(PS_TRANSIENT);
1024 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
1026 * This should not be necessary, because the SMTP listener itself
1027 * should genrate a bounce for the bad address.
1030 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
1031 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
1032 *bad_addresses, from_responses);
1033 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
1036 * It's tempting to do local notification only if bouncemail was
1037 * insufficient -- that is, to add && total_addresses > *bad_addresses
1038 * to the test here. The problem with this theory is that it would
1039 * make initial diagnosis of a broken multidrop configuration very
1040 * hard -- most single-recipient messages would just invisibly bounce.
1042 if (!(*good_addresses))
1044 if (!run.postmaster[0])
1046 if (outlevel >= O_VERBOSE)
1047 report(stderr, GT_("no address matches; no postmaster set.\n"));
1048 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
1051 if ((smtp_err = SMTP_rcpt(ctl->smtp_socket,
1052 rcpt_address (ctl, run.postmaster, 0))) == SM_UNRECOVERABLE)
1055 return(PS_TRANSIENT);
1057 if (smtp_err != SM_OK)
1059 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
1060 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
1064 if (outlevel >= O_VERBOSE)
1065 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
1069 * Tell the listener we're ready to send data.
1070 * Some listeners (like zmailer) may return antispam errors here.
1072 if ((smtp_err = SMTP_data(ctl->smtp_socket)) == SM_UNRECOVERABLE)
1075 return(PS_TRANSIENT);
1077 if (smtp_err != SM_OK)
1079 int err = handle_smtp_report(ctl, msg);
1080 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1085 * We need to stash this away in order to know how many
1086 * response lines to expect after the LMTP end-of-message.
1088 lmtp_responses = *good_addresses;
1093 static int open_mda_sink(struct query *ctl, struct msgblk *msg,
1094 int *good_addresses, int *bad_addresses)
1095 /* open a stream to a local MDA */
1099 #endif /* HAVE_SETEUID */
1101 int length = 0, fromlen = 0, nameslen = 0;
1102 char *names = NULL, *before, *after, *from = NULL;
1104 ctl->destaddr = "localhost";
1106 for (idp = msg->recipients; idp; idp = idp->next)
1107 if (idp->val.status.mark == XMIT_ACCEPT)
1108 (*good_addresses)++;
1110 length = strlen(ctl->mda);
1111 before = xstrdup(ctl->mda);
1113 /* get user addresses for %T (or %s for backward compatibility) */
1114 if (strstr(before, "%s") || strstr(before, "%T"))
1117 * We go through this in order to be able to handle very
1118 * long lists of users and (re)implement %s.
1121 for (idp = msg->recipients; idp; idp = idp->next)
1122 if ((idp->val.status.mark == XMIT_ACCEPT))
1123 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
1124 if ((*good_addresses == 0))
1125 nameslen = strlen(run.postmaster);
1127 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
1128 if (*good_addresses == 0)
1129 strcpy(names, run.postmaster);
1133 for (idp = msg->recipients; idp; idp = idp->next)
1134 if (idp->val.status.mark == XMIT_ACCEPT)
1136 strcat(names, idp->id);
1139 names[--nameslen] = '\0'; /* chop trailing space */
1145 /* get From address for %F */
1146 if (strstr(before, "%F"))
1148 from = xstrdup(msg->return_path);
1152 fromlen = strlen(from);
1155 /* do we have to build an mda string? */
1160 /* find length of resulting mda string */
1162 while ((sp = strstr(sp, "%s"))) {
1163 length += nameslen; /* subtract %s and add '' */
1167 while ((sp = strstr(sp, "%T"))) {
1168 length += nameslen; /* subtract %T and add '' */
1172 while ((sp = strstr(sp, "%F"))) {
1173 length += fromlen; /* subtract %F and add '' */
1177 after = xmalloc(length + 1);
1179 /* copy mda source string to after, while expanding %[sTF] */
1180 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
1181 if (sp[0] != '%') continue;
1183 /* need to expand? BTW, no here overflow, because in
1184 ** the worst case (end of string) sp[1] == '\0' */
1185 if (sp[1] == 's' || sp[1] == 'T') {
1190 sp++; /* position sp over [sT] */
1191 dp--; /* adjust dp */
1192 } else if (sp[1] == 'F') {
1197 sp++; /* position sp over F */
1198 dp--; /* adjust dp */
1217 if (outlevel >= O_DEBUG)
1218 report(stdout, GT_("about to deliver with: %s\n"), before);
1222 * Arrange to run with user's permissions if we're root.
1223 * This will initialize the ownership of any files the
1224 * MDA creates properly. (The seteuid call is available
1225 * under all BSDs and Linux)
1227 orig_uid = getuid();
1229 #endif /* HAVE_SETEUID */
1231 sinkfp = popen(before, "w");
1236 /* this will fail quietly if we didn't start as root */
1238 #endif /* HAVE_SETEUID */
1242 report(stderr, GT_("MDA open failed\n"));
1247 * We need to disable the normal SIGCHLD handling here because
1248 * sigchld_handler() would reap away the error status, returning
1249 * error status instead of 0 for successful completion.
1251 set_signal_handler(SIGCHLD, SIG_DFL);
1256 int open_sink(struct query *ctl, struct msgblk *msg,
1257 int *good_addresses, int *bad_addresses)
1258 /* set up sinkfp to be an input sink we can ship a message to */
1260 *bad_addresses = *good_addresses = 0;
1262 if (ctl->bsmtp) /* dump to a BSMTP batch file */
1263 return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses));
1265 * Try to forward to an SMTP or LMTP listener. If the attempt to
1266 * open a socket fails, fall through to attempt delivery via
1269 else if (!ctl->mda && smtp_open(ctl) != -1)
1270 return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses));
1273 * Awkward case. User didn't specify an MDA. Our attempt to get a
1274 * listener socket failed. Try to cope anyway -- initial configuration
1275 * may have found procmail.
1279 report(stderr, GT_("%cMTP connect to %s failed\n"),
1281 ctl->smtphost ? ctl->smtphost : "localhost");
1283 #ifndef FALLBACK_MDA
1284 /* No fallback MDA declared. Bail out. */
1288 * If user had things set up to forward offsite, no way
1289 * we want to deliver locally!
1291 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
1295 * User was delivering locally. We have a fallback MDA.
1296 * Latch it in place, logging the error, and fall through.
1297 * Set stripcr as we would if MDA had been the initial transport
1299 ctl->mda = FALLBACK_MDA;
1301 ctl->stripcr = TRUE;
1303 report(stderr, GT_("can't raise the listener; falling back to %s"),
1308 if (ctl->mda) /* must deliver through an MDA */
1309 return(open_mda_sink(ctl, msg, good_addresses, bad_addresses));
1314 void release_sink(struct query *ctl)
1315 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1317 if (ctl->bsmtp && sinkfp)
1319 if (strcmp(ctl->bsmtp, "-"))
1322 sinkfp = (FILE *)NULL;
1330 sinkfp = (FILE *)NULL;
1332 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1336 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1337 /* perform end-of-message actions on the current output sink */
1344 /* close the delivery pipe, we'll reopen before next message */
1347 rc = pclose(sinkfp);
1348 sinkfp = (FILE *)NULL;
1353 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1357 if (WIFSIGNALED(rc)) {
1359 GT_("MDA died of signal %d\n"), WTERMSIG(rc));
1360 } else if (WIFEXITED(rc)) {
1362 GT_("MDA returned nonzero status %d\n"), WEXITSTATUS(rc));
1365 GT_("Strange: MDA pclose returned %d, cannot handle at %s:%d\n"), rc, __FILE__, __LINE__);
1371 else if (ctl->bsmtp && sinkfp)
1375 /* implicit disk-full check here... */
1376 fputs(".\r\n", sinkfp);
1377 error = ferror(sinkfp);
1378 if (strcmp(ctl->bsmtp, "-"))
1380 if (fclose(sinkfp) == EOF) error = 1;
1381 sinkfp = (FILE *)NULL;
1386 GT_("Message termination or close of BSMTP file failed\n"));
1392 /* write message terminator */
1393 if ((smtp_err = SMTP_eom(ctl->smtp_socket)) == SM_UNRECOVERABLE)
1398 if (smtp_err != SM_OK)
1400 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1402 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1407 report(stderr, GT_("SMTP listener refused delivery\n"));
1408 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1414 * If this is an SMTP connection, SMTP_eom() ate the response.
1415 * But could be this is an LMTP connection, in which case we have to
1416 * interpret either (a) a single 503 response meaning there
1417 * were no successful RCPT TOs, or (b) a variable number of
1418 * responses, one for each successful RCPT TO. We need to send
1419 * bouncemail on each failed response and then return TRUE anyway,
1420 * otherwise the message will get left in the queue and resent
1421 * to people who got it the first time.
1423 if (ctl->listener == LMTP_MODE)
1425 if (lmtp_responses == 0)
1427 SMTP_ok(ctl->smtp_socket);
1430 * According to RFC2033, 503 is the only legal response
1431 * if no RCPT TO commands succeeded. No error recovery
1432 * is really possible here, as we have no idea what
1433 * insane thing the listener might be doing if it doesn't
1436 if (atoi(smtp_response) == 503)
1437 report(stderr, GT_("LMTP delivery error on EOM\n"));
1440 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1444 * It's not completely clear what to do here. We choose to
1445 * interpret delivery failure here as a transient error,
1446 * the same way SMTP delivery failure is handled. If we're
1447 * wrong, an undead message will get stuck in the queue.
1456 /* eat the RFC2033-required responses, saving errors */
1457 xalloca(responses, char **, sizeof(char *) * lmtp_responses);
1458 for (errors = i = 0; i < lmtp_responses; i++)
1460 if ((smtp_err = SMTP_ok(ctl->smtp_socket)) == SM_UNRECOVERABLE)
1465 if (smtp_err == SM_OK)
1466 responses[i] = (char *)NULL;
1469 xalloca(responses[errors],
1471 strlen(smtp_response)+1);
1472 strcpy(responses[errors], smtp_response);
1478 return(TRUE); /* all deliveries succeeded */
1481 * One or more deliveries failed.
1482 * If we can bounce a failures list back to the
1483 * sender, and the postmaster does not want to
1484 * deal with the bounces return TRUE, deleting the
1485 * message from the server so it won't be
1486 * re-forwarded on subsequent poll cycles.
1488 return(send_bouncemail(ctl, msg, XMIT_ACCEPT,
1489 "LSMTP partial delivery failure.\r\n",
1490 errors, responses));
1498 int open_warning_by_mail(struct query *ctl, struct msgblk *msg)
1499 /* set up output sink for a mailed warning to calling user */
1504 * Dispatching warning email is a little complicated. The problem is
1505 * that we have to deal with three distinct cases:
1507 * 1. Single-drop running from user account. Warning mail should
1508 * go to the local name for which we're collecting (coincides
1509 * with calling user).
1511 * 2. Single-drop running from root or other privileged ID, with rc
1512 * file generated on the fly (Ken Estes's weird setup...) Mail
1513 * should go to the local name for which we're collecting (does not
1514 * coincide with calling user).
1516 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1517 * member null so this message will fall through to run.postmaster.
1519 * The zero in the reallen element means we won't pass a SIZE
1520 * option to ESMTP; the message length would be more trouble than
1521 * it's worth to compute.
1523 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0, 0};
1526 strcat(reply.return_path, ctl->smtpaddress ? ctl->smtpaddress :
1529 if (!MULTIDROP(ctl)) /* send to calling user */
1531 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1532 status = open_sink(ctl, &reply, &good, &bad);
1533 free_str_list(&reply.recipients);
1535 else /* send to postmaster */
1536 status = open_sink(ctl, &reply, &good, &bad);
1538 stuff_warning(ctl, "Date: %s", rfc822timestamp());
1539 stuff_warning(ctl, "MIME-Version: 1.0");
1540 stuff_warning(ctl, "Content-Transfer-Encoding: 8bit");
1541 stuff_warning(ctl, "Content-Type: text/plain; charset=\"%s\"", nl_langinfo(CODESET));
1546 #if defined(HAVE_STDARG_H)
1547 void stuff_warning(struct query *ctl, const char *fmt, ... )
1549 void stuff_warning(struct query *ctl, fmt, va_alist)
1551 const char *fmt; /* printf-style format */
1554 /* format and ship a warning message line by mail */
1556 /* make huge -- i18n can bulk up error messages a lot */
1557 char buf[2*MSGBUFSIZE+4];
1561 * stuffline() requires its input to be writeable (for CR stripping),
1562 * so we needed to copy the message to a writeable buffer anyway in
1563 * case it was a string constant. We make a virtue of that necessity
1564 * here by supporting stdargs/varargs.
1566 #if defined(HAVE_STDARG_H)
1571 #ifdef HAVE_VSNPRINTF
1572 vsnprintf(buf, sizeof(buf), fmt, ap);
1574 vsprintf(buf, fmt, ap);
1578 #ifdef HAVE_SNPRINTF
1579 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1581 strcat(buf, "\r\n");
1582 #endif /* HAVE_SNPRINTF */
1584 /* guard against very long lines */
1585 buf[MSGBUFSIZE+1] = '\r';
1586 buf[MSGBUFSIZE+2] = '\n';
1587 buf[MSGBUFSIZE+3] = '\0';
1589 stuffline(ctl, buf);
1592 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1593 /* sign and send mailed warnings */
1595 stuff_warning(ctl, GT_("--\n\t\t\t\tThe Fetchmail Daemon\n"));
1596 close_sink(ctl, msg, TRUE);
1599 /* sink.c ends here */