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 int smtp_open(struct query *ctl)
50 /* try to open a socket to the appropriate SMTP server for this query */
52 char *parsed_host = NULL;
54 /* maybe it's time to close the socket in order to force delivery */
55 if (NUM_NONZERO(ctl->batchlimit) && (ctl->smtp_socket != -1) && ++batchcount == ctl->batchlimit)
57 SockClose(ctl->smtp_socket);
58 ctl->smtp_socket = -1;
62 /* if no socket to any SMTP host is already set up, try to open one */
63 if (ctl->smtp_socket == -1)
66 * RFC 1123 requires that the domain name in HELO address is a
67 * "valid principal domain name" for the client host. If we're
68 * running in invisible mode, violate this with malice
69 * aforethought in order to make the Received headers and
72 * In fact this code relies on the RFC1123 requirement that the
73 * SMTP listener must accept messages even if verification of the
74 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
76 * How we compute the true mailhost name to pass to the
77 * listener doesn't affect behavior on RFC1123-violating
78 * listeners that check for name match; we're going to lose
79 * on those anyway because we can never give them a name
80 * that matches the local machine fetchmail is running on.
81 * What it will affect is the listener's logging.
84 const char *id_me = run.invisible ? ctl->server.truename : fetchmailhost;
90 * Run down the SMTP hunt list looking for a server that's up.
91 * Use both explicit hunt entries (value TRUE) and implicit
92 * (default) ones (value FALSE).
95 phase = LISTENER_WAIT;
97 set_timeout(ctl->server.timeout);
98 for (idp = ctl->smtphunt; idp; idp = idp->next)
102 char *portnum = SMTP_PORT;
104 int portnum = SMTP_PORT;
105 #endif /* INET6_ENABLE */
107 xalloca(parsed_host, char *, strlen(idp->id) + 1);
109 ctl->smtphost = idp->id; /* remember last host tried. */
110 if(ctl->smtphost[0]=='/')
111 ctl->listener = LMTP_MODE;
113 strcpy(parsed_host, idp->id);
114 if ((cp = strrchr(parsed_host, '/')))
121 #endif /* INET6_ENABLE */
124 if (ctl->smtphost[0]=='/'){
125 if((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1)
128 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
129 ctl->server.plugout)) == -1)
132 /* return immediately for ODMR */
133 if (ctl->server.protocol == P_ODMR)
134 return(ctl->smtp_socket); /* success */
136 /* are we doing SMTP or LMTP? */
137 SMTP_setmode(ctl->listener);
139 /* first, probe for ESMTP */
140 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
141 SMTP_ehlo(ctl->smtp_socket, id_me,
142 &ctl->server.esmtp_options) == SM_OK)
146 * RFC 1869 warns that some listeners hang up on a failed EHLO,
147 * so it's safest not to assume the socket will still be good.
149 SockClose(ctl->smtp_socket);
150 ctl->smtp_socket = -1;
152 /* if opening for ESMTP failed, try SMTP */
153 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
154 ctl->server.plugout)) == -1)
157 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
158 SMTP_helo(ctl->smtp_socket, id_me) == SM_OK)
161 SockClose(ctl->smtp_socket);
162 ctl->smtp_socket = -1;
169 * RFC 1123 requires that the domain name part of the
170 * RCPT TO address be "canonicalized", that is a FQDN
171 * or MX but not a CNAME. Some listeners (like exim)
172 * enforce this. Now that we have the actual hostname,
173 * compute what we should canonicalize with.
175 * make sure we do not forget to drop the /port if
178 if (ctl->listener == LMTP_MODE && !ctl->smtpaddress)
180 if (parsed_host && parsed_host[0] != 0)
181 ctl->destaddr = xstrdup(parsed_host);
183 ctl->destaddr = (ctl->smtphost && ctl->smtphost[0] != '/') ? ctl->smtphost : "localhost";
186 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : ( ctl->smtphost && ctl->smtphost[0] != '/' ? ctl->smtphost : "localhost");
188 if (outlevel >= O_DEBUG && ctl->smtp_socket != -1)
189 report(stdout, GT_("forwarding to %s\n"), ctl->smtphost);
191 return(ctl->smtp_socket);
194 /* these are shared by open_sink and stuffline */
195 #ifndef HAVE_SIGACTION
196 static RETSIGTYPE (*sigchld)(int);
198 static struct sigaction sa_old;
199 #endif /* HAVE_SIGACTION */
202 int stuffline(struct query *ctl, char *buf)
203 /* ship a line to the given control block's output sink (SMTP server or MDA) */
208 /* The line may contain NUL characters. Find the last char to use
209 * -- the real line termination is the sequence "\n\0".
212 while ((last += strlen(last)) && (last[-1] != '\n'))
215 /* fix message lines that have only \n termination (for qmail) */
218 if (last - 1 == buf || last[-2] != '\r')
227 phase = FORWARDING_WAIT;
230 * SMTP byte-stuffing. We only do this if the protocol does *not*
231 * use .<CR><LF> as EOM. If it does, the server will already have
232 * decorated any . lines it sends back up.
236 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
241 /* writing to SMTP, leave the byte-stuffing in place */;
243 else /* if (!protocol->delimited) -- not byte-stuffed already */
246 SockWrite(ctl->smtp_socket, buf, 1); /* byte-stuff it */
248 /* leave it alone */;
252 /* we may need to strip carriage returns */
257 for (sp = tp = buf; sp < last; sp++)
265 if (ctl->mda || ctl->bsmtp)
266 n = fwrite(buf, 1, last - buf, sinkfp);
267 else if (ctl->smtp_socket != -1)
268 n = SockWrite(ctl->smtp_socket, buf, last - buf);
275 static void sanitize(char *s)
276 /* replace unsafe shellchars by an _ */
278 const static char *ok_chars = " 1234567890!@%-_=+:,./abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
281 for (cp = s; *(cp += strspn(cp, ok_chars)); /* NO INCREMENT */)
285 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
286 int userclass, char *message,
287 int nerrors, char *errors[])
288 /* bounce back an error report a la RFC 1892 */
290 char daemon_name[18 + HOSTLEN] = "FETCHMAIL-DAEMON@";
291 char boundary[BUFSIZ], *bounce_to;
294 /* don't bounce in reply to undeliverable bounces */
295 if (!msg->return_path[0] || strcmp(msg->return_path, "<>") == 0)
298 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
300 SMTP_setmode(SMTP_MODE);
302 /* can't just use fetchmailhost here, it might be localhost */
303 strcat(daemon_name, host_fqdn());
305 /* we need only SMTP for this purpose */
306 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, NULL)) == -1
307 || SMTP_ok(sock) != SM_OK
308 || SMTP_helo(sock, fetchmailhost) != SM_OK
309 || SMTP_from(sock, daemon_name, (char *)NULL) != SM_OK
310 || SMTP_rcpt(sock, bounce_to) != SM_OK
311 || SMTP_data(sock) != SM_OK)
314 /* our first duty is to keep the sacred foo counters turning... */
316 snprintf(boundary, sizeof(boundary),
319 #endif /* HAVE_SNPRINTF */
320 "foo-mani-padme-hum-%d-%d-%ld",
321 (int)getpid(), (int)getppid(), time((time_t *)NULL));
323 if (outlevel >= O_VERBOSE)
324 report(stdout, GT_("SMTP: (bounce-message body)\n"));
326 /* this will usually go to sylog... */
327 report(stderr, GT_("mail from %s bounced to %s\n"),
328 daemon_name, bounce_to);
330 /* bouncemail headers */
331 SockPrintf(sock, "Return-Path: <>\r\n");
332 SockPrintf(sock, "From: %s\r\n", daemon_name);
333 SockPrintf(sock, "To: %s\r\n", bounce_to);
334 SockPrintf(sock, "MIME-Version: 1.0\r\n");
335 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
336 SockPrintf(sock, "\r\n");
338 /* RFC1892 part 1 -- human-readable message */
339 SockPrintf(sock, "--%s\r\n", boundary);
340 SockPrintf(sock,"Content-Type: text/plain\r\n");
341 SockPrintf(sock, "\r\n");
342 SockWrite(sock, message, strlen(message));
343 SockPrintf(sock, "\r\n");
344 SockPrintf(sock, "\r\n");
351 /* RFC1892 part 2 -- machine-readable responses */
352 SockPrintf(sock, "--%s\r\n", boundary);
353 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
354 SockPrintf(sock, "\r\n");
355 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fetchmailhost);
358 for (idp = msg->recipients; idp; idp = idp->next)
359 if (idp->val.status.mark == userclass)
362 /* Minimum RFC1894 compliance + Diagnostic-Code field */
363 SockPrintf(sock, "\r\n");
364 SockPrintf(sock, "Final-Recipient: rfc822; %s@%s\r\n",
365 idp->id, fetchmailhost);
366 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
367 SockPrintf(sock, "Action: failed\r\n");
370 /* one error applies to all users */
372 else if (nerrors > nusers)
374 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
378 /* errors correspond 1-1 to selected users */
379 error = errors[nusers++];
381 if (strlen(error) > 9 && isdigit(error[4])
382 && error[5] == '.' && isdigit(error[6])
383 && error[7] == '.' && isdigit(error[8]))
384 /* Enhanced status code available, use it */
385 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
387 /* Enhanced status code not available, fake one */
388 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
389 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
391 SockPrintf(sock, "\r\n");
394 /* RFC1892 part 3 -- headers of undelivered message */
395 SockPrintf(sock, "--%s\r\n", boundary);
396 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
397 SockPrintf(sock, "\r\n");
398 SockWrite(sock, msg->headers, strlen(msg->headers));
399 SockPrintf(sock, "\r\n");
400 SockPrintf(sock, "--%s--\r\n", boundary);
402 if (SMTP_eom(sock) != SM_OK || SMTP_quit(sock))
410 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
411 /* handle SMTP errors based on the content of SMTP_response */
412 /* return of PS_REFUSED deletes mail from the server; PS_TRANSIENT keeps it */
414 int smtperr = atoi(smtp_response);
417 xalloca(responses[0], char *, strlen(smtp_response)+1);
418 strcpy(responses[0], smtp_response);
422 * Don't do this! It can really mess you up if, for example, you're
423 * reporting an error with a single RCPT TO address among several;
424 * RSET discards the message body and it doesn't get sent to the
427 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
428 if (outlevel >= O_DEBUG)
429 report(stdout, GT_("Saved error is still %d\n"), smtperr);
430 #endif /* __UNUSED */
433 * Note: send_bouncemail message strings are not made subject
434 * to gettext translation because (a) they're going to be
435 * embedded in a text/plain 7bit part, and (b) they're
436 * going to be associated with listener error-response
437 * messages, which are probably in English (none of the
438 * MTAs I know about are internationalized).
440 if (str_find(&ctl->antispam, smtperr))
443 * SMTP listener explicitly refuses to deliver mail
444 * coming from this address, probably due to an
445 * anti-spam domain exclusion. Respect this. Don't
446 * try to ship the message, and don't prevent it from
447 * being deleted. There's no point in bouncing the
448 * email either since most spammers don't put their
449 * real return email address anywhere in the headers
450 * (unless the user insists with the SET SPAMBOUNCE
455 * 571 = sendmail's "unsolicited email refused"
456 * 550 = exim's new antispam response (temporary)
457 * 501 = exim's old antispam response
458 * 554 = Postfix antispam response.
462 send_bouncemail(ctl, msg, XMIT_ACCEPT,
463 "Our spam filter rejected this transaction.\r\n",
469 * Suppress error message only if the response specifically
470 * meant `excluded for policy reasons'. We *should* see
471 * an error when the return code is less specific.
474 report(stderr, GT_("%cMTP error: %s\n"),
480 case 552: /* message exceeds fixed maximum message size */
482 * Permanent no-go condition on the
483 * ESMTP server. Don't try to ship the message,
484 * and allow it to be deleted.
486 send_bouncemail(ctl, msg, XMIT_ACCEPT,
487 "This message was too large (SMTP error 552).\r\n",
489 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
491 case 553: /* invalid sending domain */
493 * These latter days 553 usually means a spammer is trying to
494 * cover his tracks. We never bouncemail on these, because
495 * (a) the return address is invalid by definition, and
496 * (b) we wouldn't want spammers to get confirmation that
497 * this address is live, anyway.
499 send_bouncemail(ctl, msg, XMIT_ACCEPT,
500 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
505 /* bounce non-transient errors back to the sender */
506 if (smtperr >= 500 && smtperr <= 599)
507 if (send_bouncemail(ctl, msg, XMIT_ACCEPT,
508 "General SMTP/ESMTP error.\r\n",
510 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
512 * We're going to end up here on 4xx errors, like:
514 * 451: temporarily unable to identify sender (exim)
515 * 452: temporary out-of-queue-space condition on the ESMTP server.
517 * These are temporary errors. Don't try to ship the message,
518 * and suppress deletion so it can be retried on a future
521 * Bouncemail *might* be appropriate here as a delay
522 * notification (note; if we ever add this, we must make
523 * sure the RFC1894 Action field is "delayed" rather thwn
524 * "failed"). But it's not really necessary because
525 * these are not actual failures, we're very likely to be
526 * able to recover on the next cycle.
528 return(PS_TRANSIENT);
532 int open_sink(struct query *ctl, struct msgblk *msg,
533 int *good_addresses, int *bad_addresses)
534 /* set up sinkfp to be an input sink we can ship a message to */
537 #ifdef HAVE_SIGACTION
538 struct sigaction sa_new;
539 #endif /* HAVE_SIGACTION */
541 *bad_addresses = *good_addresses = 0;
543 if (ctl->bsmtp) /* dump to a BSMTP batch file */
545 if (strcmp(ctl->bsmtp, "-") == 0)
548 sinkfp = fopen(ctl->bsmtp, "a");
550 /* see the ap computation under the SMTP branch */
552 "MAIL FROM: %s", (msg->return_path[0]) ? msg->return_path : user);
554 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
555 fputs(" BODY=8BITMIME", sinkfp);
556 else if (ctl->mimemsg & MSG_IS_7BIT)
557 fputs(" BODY=7BIT", sinkfp);
559 /* exim's BSMTP processor does not handle SIZE */
560 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
562 fprintf(sinkfp, "\r\n");
565 * RFC 1123 requires that the domain name part of the
566 * RCPT TO address be "canonicalized", that is a FQDN
567 * or MX but not a CNAME. Some listeners (like exim)
568 * enforce this. Now that we have the actual hostname,
569 * compute what we should canonicalize with.
571 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : "localhost";
574 for (idp = msg->recipients; idp; idp = idp->next)
575 if (idp->val.status.mark == XMIT_ACCEPT)
578 fprintf(sinkfp, "RCPT TO: %s\r\n", ctl->smtpname);
579 else if (strchr(idp->id, '@'))
581 "RCPT TO: %s\r\n", idp->id);
584 "RCPT TO: %s@%s\r\n", idp->id, ctl->destaddr);
588 fputs("DATA\r\n", sinkfp);
592 report(stderr, GT_("BSMTP file open or preamble write failed\n"));
598 * Try to forward to an SMTP or LMTP listener. If the attempt to
599 * open a socket fails, fall through to attempt delivery via
602 else if (!ctl->mda && smtp_open(ctl) != -1)
605 char options[MSGBUFSIZE];
606 char addr[HOSTLEN+USERNAMELEN+1];
607 #ifdef EXPLICIT_BOUNCE
608 char **from_responses;
609 #endif /* EXPLICIT_BOUNCE */
613 * Compute ESMTP options.
616 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
617 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
618 strcpy(options, " BODY=8BITMIME");
619 else if (ctl->mimemsg & MSG_IS_7BIT)
620 strcpy(options, " BODY=7BIT");
623 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
624 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
627 * Try to get the SMTP listener to take the Return-Path
628 * address as MAIL FROM. If it won't, fall back on the
629 * remotename and mailserver host. This won't affect replies,
630 * which use the header From address anyway; the MAIL FROM
631 * address is a place for the SMTP listener to send
632 * bouncemail. The point is to guarantee a FQDN in the MAIL
633 * FROM line -- some SMTP listeners, like smail, become
636 * RFC 1123 requires that the domain name part of the
637 * MAIL FROM address be "canonicalized", that is a
638 * FQDN or MX but not a CNAME. We'll assume the Return-Path
639 * header is already in this form here (it certainly
640 * is if rewrite is on). RFC 1123 is silent on whether
641 * a nonexistent hostname part is considered canonical.
643 * This is a potential problem if the MTAs further upstream
644 * didn't pass canonicalized From/Return-Path lines, *and* the
645 * local SMTP listener insists on them.
647 * Handle the case where an upstream MTA is setting a return
648 * path equal to "@". Ghod knows why anyone does this, but
649 * it's been reported to happen in mail from Amazon.com and
652 if (!msg->return_path[0] || (0 == strcmp(msg->return_path, "@")))
655 snprintf(addr, sizeof(addr),
658 #endif /* HAVE_SNPRINTF */
659 "%s@%s", ctl->remotename, ctl->server.truename);
662 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
663 ap = msg->return_path;
664 else /* in case Return-Path existed but was local */
667 snprintf(addr, sizeof(addr),
670 #endif /* HAVE_SNPRINTF */
671 "%s@%s", msg->return_path, ctl->server.truename);
675 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
677 int err = handle_smtp_report(ctl, msg);
679 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
684 * Now list the recipient addressees
687 for (idp = msg->recipients; idp; idp = idp->next)
689 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
690 xalloca(from_responses, char **, sizeof(char *) * total_addresses);
691 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
692 for (idp = msg->recipients; idp; idp = idp->next)
693 if (idp->val.status.mark == XMIT_ACCEPT)
695 if (strchr(idp->id, '@'))
696 strcpy(addr, idp->id);
700 snprintf(addr, sizeof(addr)-1, "%s", ctl->smtpname);
702 sprintf(addr, "%s", ctl->smtpname);
703 #endif /* HAVE_SNPRINTF */
707 snprintf(addr, sizeof(addr)-1, "%s@%s", idp->id, ctl->destaddr);
709 sprintf(addr, "%s@%s", idp->id, ctl->destaddr);
710 #endif /* HAVE_SNPRINTF */
713 if (SMTP_rcpt(ctl->smtp_socket, addr) == SM_OK)
717 handle_smtp_report(ctl, msg);
719 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
721 snprintf(errbuf, sizeof(errbuf), "%s: %s",
722 idp->id, smtp_response);
724 strncpy(errbuf, idp->id, sizeof(errbuf));
725 strcat(errbuf, ": ");
726 strcat(errbuf, smtp_response);
727 #endif /* HAVE_SNPRINTF */
729 xalloca(from_responses[*bad_addresses],
732 strcpy(from_responses[*bad_addresses], errbuf);
733 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
736 idp->val.status.mark = XMIT_RCPTBAD;
737 if (outlevel >= O_VERBOSE)
739 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
740 ctl->listener, addr);
744 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
746 * This should not be necessary, because the SMTP listener itself
747 * should genrate a bounce for the bad address.
750 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
751 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
752 *bad_addresses, from_responses);
753 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
756 * It's tempting to do local notification only if bouncemail was
757 * insufficient -- that is, to add && total_addresses > *bad_addresses
758 * to the test here. The problem with this theory is that it would
759 * make initial diagnosis of a broken multidrop configuration very
760 * hard -- most single-recipient messages would just invisibly bounce.
762 if (!(*good_addresses))
764 if (!run.postmaster[0])
766 if (outlevel >= O_VERBOSE)
767 report(stderr, GT_("no address matches; no postmaster set.\n"));
768 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
771 if (strchr(run.postmaster, '@'))
772 strncpy(addr, run.postmaster, sizeof(addr));
776 snprintf(addr, sizeof(addr)-1, "%s@%s", run.postmaster, ctl->destaddr);
778 sprintf(addr, "%s@%s", run.postmaster, ctl->destaddr);
779 #endif /* HAVE_SNPRINTF */
782 if (SMTP_rcpt(ctl->smtp_socket, addr) != SM_OK)
784 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
785 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
789 if (outlevel >= O_VERBOSE)
790 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
794 * Tell the listener we're ready to send data.
795 * Some listeners (like zmailer) may return antispam errors here.
797 if (SMTP_data(ctl->smtp_socket) != SM_OK)
799 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
800 return(handle_smtp_report(ctl, msg));
805 * Awkward case. User didn't specify an MDA. Our attempt to get a
806 * listener socket failed. Try to cope anyway -- initial configuration
807 * may have found procmail.
811 report(stderr, GT_("%cMTP connect to %s failed\n"),
813 ctl->smtphost ? ctl->smtphost : "localhost");
816 /* No fallback MDA declared. Bail out. */
820 * If user had things set up to forward offsite, no way
821 * we want to deliver locally!
823 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
827 * User was delivering locally. We have a fallback MDA.
828 * Latch it in place, logging the error, and fall through.
830 ctl->mda = FALLBACK_MDA;
832 report(stderr, GT_("can't raise the listener; falling back to %s"),
837 if (ctl->mda) /* must deliver through an MDA */
839 int length = 0, fromlen = 0, nameslen = 0;
840 char *names = NULL, *before, *after, *from = NULL;
842 ctl->destaddr = "localhost";
844 for (idp = msg->recipients; idp; idp = idp->next)
845 if (idp->val.status.mark == XMIT_ACCEPT)
848 length = strlen(ctl->mda);
849 before = xstrdup(ctl->mda);
851 /* get user addresses for %T (or %s for backward compatibility) */
852 if (strstr(before, "%s") || strstr(before, "%T"))
855 * We go through this in order to be able to handle very
856 * long lists of users and (re)implement %s.
859 for (idp = msg->recipients; idp; idp = idp->next)
860 if ((idp->val.status.mark == XMIT_ACCEPT))
861 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
862 if ((*good_addresses == 0))
863 nameslen = strlen(run.postmaster);
865 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
866 if (*good_addresses == 0)
867 strcpy(names, run.postmaster);
871 for (idp = msg->recipients; idp; idp = idp->next)
872 if (idp->val.status.mark == XMIT_ACCEPT)
874 strcat(names, idp->id);
877 names[--nameslen] = '\0'; /* chop trailing space */
880 /* sanitize names in order to contain only harmless shell chars */
884 /* get From address for %F */
885 if (strstr(before, "%F"))
887 from = xstrdup(msg->return_path);
889 /* sanitize from in order to contain *only* harmless shell chars */
892 fromlen = strlen(from);
895 /* do we have to build an mda string? */
900 /* find length of resulting mda string */
902 while ((sp = strstr(sp, "%s"))) {
903 length += nameslen - 2; /* subtract %s */
907 while ((sp = strstr(sp, "%T"))) {
908 length += nameslen - 2; /* subtract %T */
912 while ((sp = strstr(sp, "%F"))) {
913 length += fromlen - 2; /* subtract %F */
917 after = xmalloc(length + 1);
919 /* copy mda source string to after, while expanding %[sTF] */
920 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
921 if (sp[0] != '%') continue;
923 /* need to expand? BTW, no here overflow, because in
924 ** the worst case (end of string) sp[1] == '\0' */
925 if (sp[1] == 's' || sp[1] == 'T') {
928 sp++; /* position sp over [sT] */
929 dp--; /* adjust dp */
930 } else if (sp[1] == 'F') {
933 sp++; /* position sp over F */
934 dp--; /* adjust dp */
953 if (outlevel >= O_DEBUG)
954 report(stdout, GT_("about to deliver with: %s\n"), before);
958 * Arrange to run with user's permissions if we're root.
959 * This will initialize the ownership of any files the
960 * MDA creates properly. (The seteuid call is available
961 * under all BSDs and Linux)
964 #endif /* HAVE_SETEUID */
966 sinkfp = popen(before, "w");
971 /* this will fail quietly if we didn't start as root */
973 #endif /* HAVE_SETEUID */
977 report(stderr, GT_("MDA open failed\n"));
982 * We need to disable the normal SIGCHLD handling here because
983 * sigchld_handler() would reap away the error status, returning
984 * error status instead of 0 for successful completion.
986 #ifndef HAVE_SIGACTION
987 sigchld = signal(SIGCHLD, SIG_DFL);
989 memset (&sa_new, 0, sizeof sa_new);
990 sigemptyset (&sa_new.sa_mask);
991 sa_new.sa_handler = SIG_DFL;
992 sigaction (SIGCHLD, &sa_new, NULL);
993 #endif /* HAVE_SIGACTION */
997 * We need to stash this away in order to know how many
998 * response lines to expect after the LMTP end-of-message.
1000 lmtp_responses = *good_addresses;
1005 void release_sink(struct query *ctl)
1006 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1008 if (ctl->bsmtp && sinkfp)
1015 sinkfp = (FILE *)NULL;
1017 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1021 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1022 /* perform end-of-message actions on the current output sink */
1028 /* close the delivery pipe, we'll reopen before next message */
1031 rc = pclose(sinkfp);
1032 sinkfp = (FILE *)NULL;
1037 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1042 GT_("MDA returned nonzero status %d\n"), rc);
1046 else if (ctl->bsmtp && sinkfp)
1050 /* implicit disk-full check here... */
1051 fputs(".\r\n", sinkfp);
1052 error = ferror(sinkfp);
1053 if (strcmp(ctl->bsmtp, "-"))
1054 if (fclose(sinkfp) == EOF) error = 1;
1058 GT_("Message termination or close of BSMTP file failed\n"));
1064 /* write message terminator */
1065 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1067 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1069 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1074 report(stderr, GT_("SMTP listener refused delivery\n"));
1075 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1081 * If this is an SMTP connection, SMTP_eom() ate the response.
1082 * But could be this is an LMTP connection, in which case we have to
1083 * interpret either (a) a single 503 response meaning there
1084 * were no successful RCPT TOs, or (b) a variable number of
1085 * responses, one for each successful RCPT TO. We need to send
1086 * bouncemail on each failed response and then return TRUE anyway,
1087 * otherwise the message will get left in the queue and resent
1088 * to people who got it the first time.
1090 if (ctl->listener == LMTP_MODE)
1092 if (lmtp_responses == 0)
1094 SMTP_ok(ctl->smtp_socket);
1097 * According to RFC2033, 503 is the only legal response
1098 * if no RCPT TO commands succeeded. No error recovery
1099 * is really possible here, as we have no idea what
1100 * insane thing the listener might be doing if it doesn't
1103 if (atoi(smtp_response) == 503)
1104 report(stderr, GT_("LMTP delivery error on EOM\n"));
1107 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1111 * It's not completely clear what to do here. We choose to
1112 * interpret delivery failure here as a transient error,
1113 * the same way SMTP delivery failure is handled. If we're
1114 * wrong, an undead message will get stuck in the queue.
1123 /* eat the RFC2033-required responses, saving errors */
1124 xalloca(responses, char **, sizeof(char *) * lmtp_responses);
1125 for (errors = i = 0; i < lmtp_responses; i++)
1127 if (SMTP_ok(ctl->smtp_socket) == SM_OK)
1128 responses[i] = (char *)NULL;
1131 xalloca(responses[errors],
1133 strlen(smtp_response)+1);
1134 strcpy(responses[errors], smtp_response);
1140 return(TRUE); /* all deliveries succeeded */
1143 * One or more deliveries failed.
1144 * If we can bounce a failures list back to the
1145 * sender, and the postmaster does not want to
1146 * deal with the bounces return TRUE, deleting the
1147 * message from the server so it won't be
1148 * re-forwarded on subsequent poll cycles.
1150 return(send_bouncemail(ctl, msg, XMIT_ACCEPT,
1151 "LSMTP partial delivery failure.\r\n",
1152 errors, responses));
1160 int open_warning_by_mail(struct query *ctl, struct msgblk *msg)
1161 /* set up output sink for a mailed warning to calling user */
1166 * Dispatching warning email is a little complicated. The problem is
1167 * that we have to deal with three distinct cases:
1169 * 1. Single-drop running from user account. Warning mail should
1170 * go to the local name for which we're collecting (coincides
1171 * with calling user).
1173 * 2. Single-drop running from root or other privileged ID, with rc
1174 * file generated on the fly (Ken Estes's weird setup...) Mail
1175 * should go to the local name for which we're collecting (does not
1176 * coincide with calling user).
1178 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1179 * member null so this message will fall through to run.postmaster.
1181 * The zero in the reallen element means we won't pass a SIZE
1182 * option to ESMTP; the message length would be more trouble than
1183 * it's worth to compute.
1185 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0};
1188 strcat(reply.return_path, fetchmailhost);
1190 if (!MULTIDROP(ctl)) /* send to calling user */
1192 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1193 status = open_sink(ctl, &reply, &good, &bad);
1194 free_str_list(&reply.recipients);
1196 else /* send to postmaster */
1197 status = open_sink(ctl, &reply, &good, &bad);
1198 stuff_warning(ctl, "Date: %s", rfc822timestamp());
1202 #if defined(HAVE_STDARG_H)
1203 void stuff_warning(struct query *ctl, const char *fmt, ... )
1205 void stuff_warning(struct query *ctl, fmt, va_alist)
1207 const char *fmt; /* printf-style format */
1210 /* format and ship a warning message line by mail */
1212 char buf[POPBUFSIZE];
1216 * stuffline() requires its input to be writeable (for CR stripping),
1217 * so we needed to copy the message to a writeable buffer anyway in
1218 * case it was a string constant. We make a virtue of that necessity
1219 * here by supporting stdargs/varargs.
1221 #if defined(HAVE_STDARG_H)
1226 #ifdef HAVE_VSNPRINTF
1227 vsnprintf(buf, sizeof(buf), fmt, ap);
1229 vsprintf(buf, fmt, ap);
1233 #ifdef HAVE_SNPRINTF
1234 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1236 strcat(buf, "\r\n");
1237 #endif /* HAVE_SNPRINTF */
1239 stuffline(ctl, buf);
1242 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1243 /* sign and send mailed warnings */
1245 stuff_warning(ctl, GT_("--\r\n\t\t\t\tThe Fetchmail Daemon\r\n"));
1246 close_sink(ctl, msg, TRUE);
1249 /* sink.c ends here */