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.
21 #endif /* HAVE_MEMORY_H */
22 #if defined(STDC_HEADERS)
25 #if defined(HAVE_UNISTD_H)
28 #if defined(HAVE_STDARG_H)
36 #include "fetchmail.h"
41 /* BSD portability hack...I know, this is an ugly place to put it */
42 #if !defined(SIGCHLD) && defined(SIGCLD)
43 #define SIGCHLD SIGCLD
46 /* makes the open_sink()/close_sink() pair non-reentrant */
47 static int lmtp_responses;
49 void smtp_close(struct query *ctl, int sayquit)
50 /* close the socket to SMTP server */
52 if (ctl->smtp_socket != -1)
55 SMTP_quit(ctl->smtp_socket);
56 SockClose(ctl->smtp_socket);
57 ctl->smtp_socket = -1;
62 int smtp_open(struct query *ctl)
63 /* try to open a socket to the appropriate SMTP server for this query */
65 char *parsed_host = NULL;
67 /* maybe it's time to close the socket in order to force delivery */
68 if (NUM_NONZERO(ctl->batchlimit)) {
69 if (batchcount == ctl->batchlimit)
74 /* if no socket to any SMTP host is already set up, try to open one */
75 if (ctl->smtp_socket == -1)
78 * RFC 1123 requires that the domain name in HELO address is a
79 * "valid principal domain name" for the client host. If we're
80 * running in invisible mode, violate this with malice
81 * aforethought in order to make the Received headers and
84 * In fact this code relies on the RFC1123 requirement that the
85 * SMTP listener must accept messages even if verification of the
86 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
88 * How we compute the true mailhost name to pass to the
89 * listener doesn't affect behavior on RFC1123-violating
90 * listeners that check for name match; we're going to lose
91 * on those anyway because we can never give them a name
92 * that matches the local machine fetchmail is running on.
93 * What it will affect is the listener's logging.
96 const char *id_me = run.invisible ? ctl->server.truename : fetchmailhost;
102 * Run down the SMTP hunt list looking for a server that's up.
103 * Use both explicit hunt entries (value TRUE) and implicit
104 * (default) ones (value FALSE).
107 phase = LISTENER_WAIT;
109 set_timeout(ctl->server.timeout);
110 for (idp = ctl->smtphunt; idp; idp = idp->next)
114 char *portnum = SMTP_PORT;
116 int portnum = SMTP_PORT;
117 #endif /* INET6_ENABLE */
119 xalloca(parsed_host, char *, strlen(idp->id) + 1);
121 ctl->smtphost = idp->id; /* remember last host tried. */
122 if(ctl->smtphost[0]=='/')
123 ctl->listener = LMTP_MODE;
125 strcpy(parsed_host, idp->id);
126 if ((cp = strrchr(parsed_host, '/')))
133 #endif /* INET6_ENABLE */
136 if (ctl->smtphost[0]=='/'){
137 if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1)
140 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
141 ctl->server.plugout)) == -1)
144 /* return immediately for ODMR */
145 if (ctl->server.protocol == P_ODMR)
149 return(ctl->smtp_socket); /* success */
152 /* are we doing SMTP or LMTP? */
153 SMTP_setmode(ctl->listener);
155 /* first, probe for ESMTP */
156 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
157 SMTP_ehlo(ctl->smtp_socket, id_me,
158 ctl->server.esmtp_name, ctl->server.esmtp_password,
159 &ctl->server.esmtp_options) == SM_OK)
163 * RFC 1869 warns that some listeners hang up on a failed EHLO,
164 * so it's safest not to assume the socket will still be good.
168 /* if opening for ESMTP failed, try SMTP */
169 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
170 ctl->server.plugout)) == -1)
173 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
174 SMTP_helo(ctl->smtp_socket, id_me) == SM_OK)
184 * RFC 1123 requires that the domain name part of the
185 * RCPT TO address be "canonicalized", that is a FQDN
186 * or MX but not a CNAME. Some listeners (like exim)
187 * enforce this. Now that we have the actual hostname,
188 * compute what we should canonicalize with.
190 * make sure we do not forget to drop the /port if
193 if (ctl->listener == LMTP_MODE && !ctl->smtpaddress)
195 if (parsed_host && parsed_host[0] != 0)
196 ctl->destaddr = xstrdup(parsed_host);
198 ctl->destaddr = (ctl->smtphost && ctl->smtphost[0] != '/') ? ctl->smtphost : "localhost";
201 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : ( ctl->smtphost && ctl->smtphost[0] != '/' ? ctl->smtphost : "localhost");
203 if (outlevel >= O_DEBUG && ctl->smtp_socket != -1)
204 report(stdout, GT_("forwarding to %s\n"), ctl->smtphost);
206 return(ctl->smtp_socket);
209 static void sanitize(char *s)
210 /* replace unsafe shellchars by an _ */
212 const static char *ok_chars = " 1234567890!@%-_=+:,./abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
215 for (cp = s; *(cp += strspn(cp, ok_chars)); /* NO INCREMENT */)
219 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
220 int userclass, char *message,
221 int nerrors, char *errors[])
222 /* bounce back an error report a la RFC 1892 */
224 char daemon_name[18 + HOSTLEN] = "FETCHMAIL-DAEMON@";
225 char boundary[BUFSIZ], *bounce_to;
228 /* don't bounce in reply to undeliverable bounces */
229 if (!msg->return_path[0] || strcmp(msg->return_path, "<>") == 0)
232 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
234 SMTP_setmode(SMTP_MODE);
236 /* can't just use fetchmailhost here, it might be localhost */
237 strcat(daemon_name, host_fqdn());
239 /* we need only SMTP for this purpose */
240 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, NULL)) == -1)
243 if (SMTP_ok(sock) != SM_OK)
249 if (SMTP_helo(sock, fetchmailhost) != SM_OK
250 || SMTP_from(sock, daemon_name, (char *)NULL) != SM_OK
251 || SMTP_rcpt(sock, bounce_to) != SM_OK
252 || SMTP_data(sock) != SM_OK)
259 /* our first duty is to keep the sacred foo counters turning... */
261 snprintf(boundary, sizeof(boundary),
264 #endif /* HAVE_SNPRINTF */
265 "foo-mani-padme-hum-%d-%d-%ld",
266 (int)getpid(), (int)getppid(), time((time_t *)NULL));
268 if (outlevel >= O_VERBOSE)
269 report(stdout, GT_("SMTP: (bounce-message body)\n"));
271 /* this will usually go to sylog... */
272 report(stderr, GT_("mail from %s bounced to %s\n"),
273 daemon_name, bounce_to);
275 /* bouncemail headers */
276 SockPrintf(sock, "Return-Path: <>\r\n");
277 SockPrintf(sock, "From: %s\r\n", daemon_name);
278 SockPrintf(sock, "To: %s\r\n", bounce_to);
279 SockPrintf(sock, "MIME-Version: 1.0\r\n");
280 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
281 SockPrintf(sock, "\r\n");
283 /* RFC1892 part 1 -- human-readable message */
284 SockPrintf(sock, "--%s\r\n", boundary);
285 SockPrintf(sock,"Content-Type: text/plain\r\n");
286 SockPrintf(sock, "\r\n");
287 SockWrite(sock, message, strlen(message));
288 SockPrintf(sock, "\r\n");
289 SockPrintf(sock, "\r\n");
296 /* RFC1892 part 2 -- machine-readable responses */
297 SockPrintf(sock, "--%s\r\n", boundary);
298 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
299 SockPrintf(sock, "\r\n");
300 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fetchmailhost);
303 for (idp = msg->recipients; idp; idp = idp->next)
304 if (idp->val.status.mark == userclass)
307 /* Minimum RFC1894 compliance + Diagnostic-Code field */
308 SockPrintf(sock, "\r\n");
309 SockPrintf(sock, "Final-Recipient: rfc822; %s@%s\r\n",
310 idp->id, fetchmailhost);
311 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
312 SockPrintf(sock, "Action: failed\r\n");
315 /* one error applies to all users */
317 else if (nerrors > nusers)
319 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
323 /* errors correspond 1-1 to selected users */
324 error = errors[nusers++];
326 if (strlen(error) > 9 && isdigit(error[4])
327 && error[5] == '.' && isdigit(error[6])
328 && error[7] == '.' && isdigit(error[8]))
329 /* Enhanced status code available, use it */
330 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
332 /* Enhanced status code not available, fake one */
333 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
334 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
336 SockPrintf(sock, "\r\n");
339 /* RFC1892 part 3 -- headers of undelivered message */
340 SockPrintf(sock, "--%s\r\n", boundary);
341 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
342 SockPrintf(sock, "\r\n");
343 SockWrite(sock, msg->headers, strlen(msg->headers));
344 SockPrintf(sock, "\r\n");
345 SockPrintf(sock, "--%s--\r\n", boundary);
347 if (SMTP_eom(sock) != SM_OK || SMTP_quit(sock))
358 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
359 /* handle SMTP errors based on the content of SMTP_response */
360 /* return of PS_REFUSED deletes mail from the server; PS_TRANSIENT keeps it */
362 int smtperr = atoi(smtp_response);
365 xalloca(responses[0], char *, strlen(smtp_response)+1);
366 strcpy(responses[0], smtp_response);
370 * Don't do this! It can really mess you up if, for example, you're
371 * reporting an error with a single RCPT TO address among several;
372 * RSET discards the message body and it doesn't get sent to the
375 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
376 if (outlevel >= O_DEBUG)
377 report(stdout, GT_("Saved error is still %d\n"), smtperr);
378 #endif /* __UNUSED */
381 * Note: send_bouncemail message strings are not made subject
382 * to gettext translation because (a) they're going to be
383 * embedded in a text/plain 7bit part, and (b) they're
384 * going to be associated with listener error-response
385 * messages, which are probably in English (none of the
386 * MTAs I know about are internationalized).
388 if (str_find(&ctl->antispam, smtperr))
391 * SMTP listener explicitly refuses to deliver mail
392 * coming from this address, probably due to an
393 * anti-spam domain exclusion. Respect this. Don't
394 * try to ship the message, and don't prevent it from
395 * being deleted. There's no point in bouncing the
396 * email either since most spammers don't put their
397 * real return email address anywhere in the headers
398 * (unless the user insists with the SET SPAMBOUNCE
403 * 571 = sendmail's "unsolicited email refused"
404 * 550 = exim's new antispam response (temporary)
405 * 501 = exim's old antispam response
406 * 554 = Postfix antispam response.
413 snprintf(rejmsg, sizeof(rejmsg),
416 #endif /* HAVE_SNPRINTF */
417 "spam filter or virus scanner rejected message because:\r\n"
418 "%s\r\n", responses[0]);
420 send_bouncemail(ctl, msg, XMIT_ACCEPT,
421 rejmsg, 1, responses);
427 * Suppress error message only if the response specifically
428 * meant `excluded for policy reasons'. We *should* see
429 * an error when the return code is less specific.
432 report(stderr, GT_("%cMTP error: %s\n"),
438 case 552: /* message exceeds fixed maximum message size */
440 * Permanent no-go condition on the
441 * ESMTP server. Don't try to ship the message,
442 * and allow it to be deleted.
445 send_bouncemail(ctl, msg, XMIT_ACCEPT,
446 "This message was too large (SMTP error 552).\r\n",
450 case 553: /* invalid sending domain */
452 * These latter days 553 usually means a spammer is trying to
453 * cover his tracks. We never bouncemail on these, because
454 * (a) the return address is invalid by definition, and
455 * (b) we wouldn't want spammers to get confirmation that
456 * this address is live, anyway.
458 #ifdef __DONT_FEED_THE_SPAMMERS__
460 send_bouncemail(ctl, msg, XMIT_ACCEPT,
461 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
463 #endif /* __DONT_FEED_THE_SPAMMERS__ */
467 /* bounce non-transient errors back to the sender */
468 if (smtperr >= 500 && smtperr <= 599)
469 if (send_bouncemail(ctl, msg, XMIT_ACCEPT,
470 "General SMTP/ESMTP error.\r\n",
472 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
474 * We're going to end up here on 4xx errors, like:
476 * 451: temporarily unable to identify sender (exim)
477 * 452: temporary out-of-queue-space condition on the ESMTP server.
479 * These are temporary errors. Don't try to ship the message,
480 * and suppress deletion so it can be retried on a future
483 * Bouncemail *might* be appropriate here as a delay
484 * notification (note; if we ever add this, we must make
485 * sure the RFC1894 Action field is "delayed" rather than
486 * "failed"). But it's not really necessary because
487 * these are not actual failures, we're very likely to be
488 * able to recover on the next cycle.
490 return(PS_TRANSIENT);
494 /* these are shared by open_sink and stuffline */
497 int stuffline(struct query *ctl, char *buf)
498 /* ship a line to the given control block's output sink (SMTP server or MDA) */
503 /* The line may contain NUL characters. Find the last char to use
504 * -- the real line termination is the sequence "\n\0".
507 while ((last += strlen(last)) && (last[-1] != '\n'))
510 /* fix message lines that have only \n termination (for qmail) */
513 if (last - 1 == buf || last[-2] != '\r')
522 phase = FORWARDING_WAIT;
525 * SMTP byte-stuffing. We only do this if the protocol does *not*
526 * use .<CR><LF> as EOM. If it does, the server will already have
527 * decorated any . lines it sends back up.
531 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
536 /* writing to SMTP, leave the byte-stuffing in place */;
538 else /* if (!protocol->delimited) -- not byte-stuffed already */
541 SockWrite(ctl->smtp_socket, buf, 1); /* byte-stuff it */
543 /* leave it alone */;
547 /* we may need to strip carriage returns */
552 for (sp = tp = buf; sp < last; sp++)
560 if (ctl->mda || ctl->bsmtp)
561 n = fwrite(buf, 1, last - buf, sinkfp);
562 else if (ctl->smtp_socket != -1)
563 n = SockWrite(ctl->smtp_socket, buf, last - buf);
570 static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg,
571 int *good_addresses, int *bad_addresses)
572 /* open a BSMTP stream */
576 if (strcmp(ctl->bsmtp, "-") == 0)
579 sinkfp = fopen(ctl->bsmtp, "a");
581 /* see the ap computation under the SMTP branch */
583 "MAIL FROM: %s", (msg->return_path[0]) ? msg->return_path : user);
585 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
586 fputs(" BODY=8BITMIME", sinkfp);
587 else if (ctl->mimemsg & MSG_IS_7BIT)
588 fputs(" BODY=7BIT", sinkfp);
590 /* exim's BSMTP processor does not handle SIZE */
591 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
593 fprintf(sinkfp, "\r\n");
596 * RFC 1123 requires that the domain name part of the
597 * RCPT TO address be "canonicalized", that is a FQDN
598 * or MX but not a CNAME. Some listeners (like exim)
599 * enforce this. Now that we have the actual hostname,
600 * compute what we should canonicalize with.
602 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : "localhost";
605 for (idp = msg->recipients; idp; idp = idp->next)
606 if (idp->val.status.mark == XMIT_ACCEPT)
609 fprintf(sinkfp, "RCPT TO: %s\r\n", ctl->smtpname);
610 else if (strchr(idp->id, '@'))
612 "RCPT TO: %s\r\n", idp->id);
615 "RCPT TO: %s@%s\r\n", idp->id, ctl->destaddr);
619 fputs("DATA\r\n", sinkfp);
623 report(stderr, GT_("BSMTP file open or preamble write failed\n"));
630 /* this is experimental and will be removed if double bounces are reported */
631 #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS
634 static const char *is_quad(const char *q)
635 /* Check if the string passed in points to what could be one quad of a
636 * dotted-quad IP address. Requirements are that the string is not a
637 * NULL pointer, begins with a period (which is skipped) or a digit
638 * and ends with a period or a NULL. If these requirements are met, a
639 * pointer to the last character (the period or the NULL character) is
640 * returned; otherwise NULL.
649 for(r=q;isdigit(*r);r++)
651 if ( ((*r) && (*r != '.')) || ((r-q) < 1) || ((r-q)>3) )
653 /* Make sure quad is < 255 */
661 else if (*(q+1) == '5')
670 static int is_dottedquad(const char *hostname)
671 /* Returns a true value if the passed in string looks like an IP
672 * address in dotted-quad form, and a false value otherwise.
676 return ((hostname=is_quad(is_quad(is_quad(is_quad(hostname))))) != NULL) &&
680 static int open_smtp_sink(struct query *ctl, struct msgblk *msg,
681 int *good_addresses, int *bad_addresses)
682 /* open an SMTP stream */
686 char options[MSGBUFSIZE];
687 char addr[HOSTLEN+USERNAMELEN+1];
688 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
689 char **from_responses;
690 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
692 int force_transient_error = 0;
695 * Compute ESMTP options.
698 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
699 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
700 strcpy(options, " BODY=8BITMIME");
701 else if (ctl->mimemsg & MSG_IS_7BIT)
702 strcpy(options, " BODY=7BIT");
705 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
706 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
709 * Try to get the SMTP listener to take the Return-Path
710 * address as MAIL FROM. If it won't, fall back on the
711 * remotename and mailserver host. This won't affect replies,
712 * which use the header From address anyway; the MAIL FROM
713 * address is a place for the SMTP listener to send
714 * bouncemail. The point is to guarantee a FQDN in the MAIL
715 * FROM line -- some SMTP listeners, like smail, become
718 * RFC 1123 requires that the domain name part of the
719 * MAIL FROM address be "canonicalized", that is a
720 * FQDN or MX but not a CNAME. We'll assume the Return-Path
721 * header is already in this form here (it certainly
722 * is if rewrite is on). RFC 1123 is silent on whether
723 * a nonexistent hostname part is considered canonical.
725 * This is a potential problem if the MTAs further upstream
726 * didn't pass canonicalized From/Return-Path lines, *and* the
727 * local SMTP listener insists on them.
729 * Handle the case where an upstream MTA is setting a return
730 * path equal to "@". Ghod knows why anyone does this, but
731 * it's been reported to happen in mail from Amazon.com and
734 * Also, if the hostname is a dotted quad, wrap it in square brackets.
735 * Apparently this is required by RFC2821, section 4.1.3.
737 if (!msg->return_path[0] || (0 == strcmp(msg->return_path, "@")))
739 if (is_dottedquad(ctl->server.truename))
742 snprintf(addr, sizeof(addr),
745 #endif /* HAVE_SNPRINTF */
746 "%s@[%s]", ctl->remotename, ctl->server.truename);
751 snprintf(addr, sizeof(addr),
754 #endif /* HAVE_SNPRINTF */
755 "%s@%s", ctl->remotename, ctl->server.truename);
759 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
760 ap = msg->return_path;
761 else /* in case Return-Path existed but was local */
763 if (is_dottedquad(ctl->server.truename))
766 snprintf(addr, sizeof(addr),
769 #endif /* HAVE_SNPRINTF */
770 "%s@[%s]", msg->return_path, ctl->server.truename);
775 snprintf(addr, sizeof(addr),
778 #endif /* HAVE_SNPRINTF */
779 "%s@%s", msg->return_path, ctl->server.truename);
784 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
786 int err = handle_smtp_report(ctl, msg);
788 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
793 * Now list the recipient addressees
796 for (idp = msg->recipients; idp; idp = idp->next)
798 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
799 xalloca(from_responses, char **, sizeof(char *) * total_addresses);
800 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
801 for (idp = msg->recipients; idp; idp = idp->next)
802 if (idp->val.status.mark == XMIT_ACCEPT)
804 if (strchr(idp->id, '@'))
805 strcpy(addr, idp->id);
809 snprintf(addr, sizeof(addr), "%s", ctl->smtpname);
811 sprintf(addr, "%s", ctl->smtpname);
812 #endif /* HAVE_SNPRINTF */
816 snprintf(addr, sizeof(addr), "%s@%s", idp->id, ctl->destaddr);
818 sprintf(addr, "%s@%s", idp->id, ctl->destaddr);
819 #endif /* HAVE_SNPRINTF */
822 if (SMTP_rcpt(ctl->smtp_socket, addr) == SM_OK)
826 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
827 char errbuf[POPBUFSIZE];
828 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
829 if (handle_smtp_report(ctl, msg) == PS_TRANSIENT)
830 force_transient_error = 1;
832 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
834 snprintf(errbuf, sizeof(errbuf), "%s: %s",
835 idp->id, smtp_response);
837 strncpy(errbuf, idp->id, sizeof(errbuf));
838 strcat(errbuf, ": ");
839 strcat(errbuf, smtp_response);
840 #endif /* HAVE_SNPRINTF */
842 xalloca(from_responses[*bad_addresses],
845 strcpy(from_responses[*bad_addresses], errbuf);
846 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
849 idp->val.status.mark = XMIT_RCPTBAD;
850 if (outlevel >= O_VERBOSE)
852 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
853 ctl->listener, addr);
857 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
859 * This should not be necessary, because the SMTP listener itself
860 * should genrate a bounce for the bad address.
863 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
864 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
865 *bad_addresses, from_responses);
866 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
869 * It's tempting to do local notification only if bouncemail was
870 * insufficient -- that is, to add && total_addresses > *bad_addresses
871 * to the test here. The problem with this theory is that it would
872 * make initial diagnosis of a broken multidrop configuration very
873 * hard -- most single-recipient messages would just invisibly bounce.
875 if (!(*good_addresses))
877 if (force_transient_error) {
878 /* do not risk dataloss due to overengineered multidrop
879 * crap. If one of the recipients returned PS_TRANSIENT,
880 * we return exactly that.
882 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
883 return(PS_TRANSIENT);
885 if (!run.postmaster[0])
887 if (outlevel >= O_VERBOSE)
888 report(stderr, GT_("no address matches; no postmaster set.\n"));
889 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
892 if (strchr(run.postmaster, '@'))
893 strncpy(addr, run.postmaster, sizeof(addr));
897 snprintf(addr, sizeof(addr), "%s@%s", run.postmaster, ctl->destaddr);
899 sprintf(addr, "%s@%s", run.postmaster, ctl->destaddr);
900 #endif /* HAVE_SNPRINTF */
903 if (SMTP_rcpt(ctl->smtp_socket, addr) != SM_OK)
905 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
906 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
910 if (outlevel >= O_VERBOSE)
911 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
915 * Tell the listener we're ready to send data.
916 * Some listeners (like zmailer) may return antispam errors here.
918 if (SMTP_data(ctl->smtp_socket) != SM_OK)
920 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
921 return(handle_smtp_report(ctl, msg));
925 * We need to stash this away in order to know how many
926 * response lines to expect after the LMTP end-of-message.
928 lmtp_responses = *good_addresses;
933 static int open_mda_sink(struct query *ctl, struct msgblk *msg,
934 int *good_addresses, int *bad_addresses)
935 /* open a stream to a local MDA */
937 #ifdef HAVE_SIGACTION
938 struct sigaction sa_new;
939 #endif /* HAVE_SIGACTION */
941 int length = 0, fromlen = 0, nameslen = 0;
942 char *names = NULL, *before, *after, *from = NULL;
944 ctl->destaddr = "localhost";
946 for (idp = msg->recipients; idp; idp = idp->next)
947 if (idp->val.status.mark == XMIT_ACCEPT)
950 length = strlen(ctl->mda);
951 before = xstrdup(ctl->mda);
953 /* get user addresses for %T (or %s for backward compatibility) */
954 if (strstr(before, "%s") || strstr(before, "%T"))
957 * We go through this in order to be able to handle very
958 * long lists of users and (re)implement %s.
961 for (idp = msg->recipients; idp; idp = idp->next)
962 if ((idp->val.status.mark == XMIT_ACCEPT))
963 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
964 if ((*good_addresses == 0))
965 nameslen = strlen(run.postmaster);
967 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
968 if (*good_addresses == 0)
969 strcpy(names, run.postmaster);
973 for (idp = msg->recipients; idp; idp = idp->next)
974 if (idp->val.status.mark == XMIT_ACCEPT)
976 strcat(names, idp->id);
979 names[--nameslen] = '\0'; /* chop trailing space */
982 /* sanitize names in order to contain only harmless shell chars */
986 /* get From address for %F */
987 if (strstr(before, "%F"))
989 from = xstrdup(msg->return_path);
991 /* sanitize from in order to contain *only* harmless shell chars */
994 fromlen = strlen(from);
997 /* do we have to build an mda string? */
1002 /* find length of resulting mda string */
1004 while ((sp = strstr(sp, "%s"))) {
1005 length += nameslen - 2; /* subtract %s */
1009 while ((sp = strstr(sp, "%T"))) {
1010 length += nameslen - 2; /* subtract %T */
1014 while ((sp = strstr(sp, "%F"))) {
1015 length += fromlen - 2; /* subtract %F */
1019 after = xmalloc(length + 1);
1021 /* copy mda source string to after, while expanding %[sTF] */
1022 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
1023 if (sp[0] != '%') continue;
1025 /* need to expand? BTW, no here overflow, because in
1026 ** the worst case (end of string) sp[1] == '\0' */
1027 if (sp[1] == 's' || sp[1] == 'T') {
1030 sp++; /* position sp over [sT] */
1031 dp--; /* adjust dp */
1032 } else if (sp[1] == 'F') {
1035 sp++; /* position sp over F */
1036 dp--; /* adjust dp */
1055 if (outlevel >= O_DEBUG)
1056 report(stdout, GT_("about to deliver with: %s\n"), before);
1060 * Arrange to run with user's permissions if we're root.
1061 * This will initialize the ownership of any files the
1062 * MDA creates properly. (The seteuid call is available
1063 * under all BSDs and Linux)
1066 #endif /* HAVE_SETEUID */
1068 sinkfp = popen(before, "w");
1073 /* this will fail quietly if we didn't start as root */
1075 #endif /* HAVE_SETEUID */
1079 report(stderr, GT_("MDA open failed\n"));
1084 * We need to disable the normal SIGCHLD handling here because
1085 * sigchld_handler() would reap away the error status, returning
1086 * error status instead of 0 for successful completion.
1088 #ifndef HAVE_SIGACTION
1089 signal(SIGCHLD, SIG_DFL);
1091 memset (&sa_new, 0, sizeof sa_new);
1092 sigemptyset (&sa_new.sa_mask);
1093 sa_new.sa_handler = SIG_DFL;
1094 sigaction (SIGCHLD, &sa_new, NULL);
1095 #endif /* HAVE_SIGACTION */
1100 int open_sink(struct query *ctl, struct msgblk *msg,
1101 int *good_addresses, int *bad_addresses)
1102 /* set up sinkfp to be an input sink we can ship a message to */
1104 *bad_addresses = *good_addresses = 0;
1106 if (ctl->bsmtp) /* dump to a BSMTP batch file */
1107 return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses));
1109 * Try to forward to an SMTP or LMTP listener. If the attempt to
1110 * open a socket fails, fall through to attempt delivery via
1113 else if (!ctl->mda && smtp_open(ctl) != -1)
1114 return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses));
1117 * Awkward case. User didn't specify an MDA. Our attempt to get a
1118 * listener socket failed. Try to cope anyway -- initial configuration
1119 * may have found procmail.
1123 report(stderr, GT_("%cMTP connect to %s failed\n"),
1125 ctl->smtphost ? ctl->smtphost : "localhost");
1127 #ifndef FALLBACK_MDA
1128 /* No fallback MDA declared. Bail out. */
1132 * If user had things set up to forward offsite, no way
1133 * we want to deliver locally!
1135 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
1139 * User was delivering locally. We have a fallback MDA.
1140 * Latch it in place, logging the error, and fall through.
1141 * Set stripcr as we would if MDA had been the initial transport
1143 ctl->mda = FALLBACK_MDA;
1145 ctl->stripcr = TRUE;
1147 report(stderr, GT_("can't raise the listener; falling back to %s"),
1152 if (ctl->mda) /* must deliver through an MDA */
1153 return(open_mda_sink(ctl, msg, good_addresses, bad_addresses));
1158 void release_sink(struct query *ctl)
1159 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1161 if (ctl->bsmtp && sinkfp)
1168 sinkfp = (FILE *)NULL;
1170 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1174 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1175 /* perform end-of-message actions on the current output sink */
1181 /* close the delivery pipe, we'll reopen before next message */
1184 rc = pclose(sinkfp);
1185 sinkfp = (FILE *)NULL;
1190 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1195 GT_("MDA returned nonzero status %d\n"), rc);
1199 else if (ctl->bsmtp && sinkfp)
1203 /* implicit disk-full check here... */
1204 fputs(".\r\n", sinkfp);
1205 error = ferror(sinkfp);
1206 if (strcmp(ctl->bsmtp, "-"))
1207 if (fclose(sinkfp) == EOF) error = 1;
1211 GT_("Message termination or close of BSMTP file failed\n"));
1217 /* write message terminator */
1218 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1220 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1222 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1227 report(stderr, GT_("SMTP listener refused delivery\n"));
1228 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1234 * If this is an SMTP connection, SMTP_eom() ate the response.
1235 * But could be this is an LMTP connection, in which case we have to
1236 * interpret either (a) a single 503 response meaning there
1237 * were no successful RCPT TOs, or (b) a variable number of
1238 * responses, one for each successful RCPT TO. We need to send
1239 * bouncemail on each failed response and then return TRUE anyway,
1240 * otherwise the message will get left in the queue and resent
1241 * to people who got it the first time.
1243 if (ctl->listener == LMTP_MODE)
1245 if (lmtp_responses == 0)
1247 SMTP_ok(ctl->smtp_socket);
1250 * According to RFC2033, 503 is the only legal response
1251 * if no RCPT TO commands succeeded. No error recovery
1252 * is really possible here, as we have no idea what
1253 * insane thing the listener might be doing if it doesn't
1256 if (atoi(smtp_response) == 503)
1257 report(stderr, GT_("LMTP delivery error on EOM\n"));
1260 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1264 * It's not completely clear what to do here. We choose to
1265 * interpret delivery failure here as a transient error,
1266 * the same way SMTP delivery failure is handled. If we're
1267 * wrong, an undead message will get stuck in the queue.
1276 /* eat the RFC2033-required responses, saving errors */
1277 xalloca(responses, char **, sizeof(char *) * lmtp_responses);
1278 for (errors = i = 0; i < lmtp_responses; i++)
1280 if (SMTP_ok(ctl->smtp_socket) == SM_OK)
1281 responses[i] = (char *)NULL;
1284 xalloca(responses[errors],
1286 strlen(smtp_response)+1);
1287 strcpy(responses[errors], smtp_response);
1293 return(TRUE); /* all deliveries succeeded */
1296 * One or more deliveries failed.
1297 * If we can bounce a failures list back to the
1298 * sender, and the postmaster does not want to
1299 * deal with the bounces return TRUE, deleting the
1300 * message from the server so it won't be
1301 * re-forwarded on subsequent poll cycles.
1303 return(send_bouncemail(ctl, msg, XMIT_ACCEPT,
1304 "LSMTP partial delivery failure.\r\n",
1305 errors, responses));
1313 int open_warning_by_mail(struct query *ctl, struct msgblk *msg)
1314 /* set up output sink for a mailed warning to calling user */
1319 * Dispatching warning email is a little complicated. The problem is
1320 * that we have to deal with three distinct cases:
1322 * 1. Single-drop running from user account. Warning mail should
1323 * go to the local name for which we're collecting (coincides
1324 * with calling user).
1326 * 2. Single-drop running from root or other privileged ID, with rc
1327 * file generated on the fly (Ken Estes's weird setup...) Mail
1328 * should go to the local name for which we're collecting (does not
1329 * coincide with calling user).
1331 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1332 * member null so this message will fall through to run.postmaster.
1334 * The zero in the reallen element means we won't pass a SIZE
1335 * option to ESMTP; the message length would be more trouble than
1336 * it's worth to compute.
1338 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0};
1341 strcat(reply.return_path, ctl->smtpaddress ? ctl->smtpaddress :
1344 if (!MULTIDROP(ctl)) /* send to calling user */
1346 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1347 status = open_sink(ctl, &reply, &good, &bad);
1348 free_str_list(&reply.recipients);
1350 else /* send to postmaster */
1351 status = open_sink(ctl, &reply, &good, &bad);
1352 stuff_warning(ctl, "Date: %s", rfc822timestamp());
1356 #if defined(HAVE_STDARG_H)
1357 void stuff_warning(struct query *ctl, const char *fmt, ... )
1359 void stuff_warning(struct query *ctl, fmt, va_alist)
1361 const char *fmt; /* printf-style format */
1364 /* format and ship a warning message line by mail */
1366 char buf[POPBUFSIZE];
1370 * stuffline() requires its input to be writeable (for CR stripping),
1371 * so we needed to copy the message to a writeable buffer anyway in
1372 * case it was a string constant. We make a virtue of that necessity
1373 * here by supporting stdargs/varargs.
1375 #if defined(HAVE_STDARG_H)
1380 #ifdef HAVE_VSNPRINTF
1381 vsnprintf(buf, sizeof(buf), fmt, ap);
1383 vsprintf(buf, fmt, ap);
1387 #ifdef HAVE_SNPRINTF
1388 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1390 strcat(buf, "\r\n");
1391 #endif /* HAVE_SNPRINTF */
1393 stuffline(ctl, buf);
1396 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1397 /* sign and send mailed warnings */
1399 stuff_warning(ctl, GT_("--\r\n\t\t\t\tThe Fetchmail Daemon\r\n"));
1400 close_sink(ctl, msg, TRUE);
1403 /* sink.c ends here */