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 static void sanitize(char *s)
195 /* replace unsafe shellchars by an _ */
197 const static char *ok_chars = " 1234567890!@%-_=+:,./abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
200 for (cp = s; *(cp += strspn(cp, ok_chars)); /* NO INCREMENT */)
204 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
205 int userclass, char *message,
206 int nerrors, char *errors[])
207 /* bounce back an error report a la RFC 1892 */
209 char daemon_name[18 + HOSTLEN] = "FETCHMAIL-DAEMON@";
210 char boundary[BUFSIZ], *bounce_to;
213 /* don't bounce in reply to undeliverable bounces */
214 if (!msg->return_path[0] || strcmp(msg->return_path, "<>") == 0)
217 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
219 SMTP_setmode(SMTP_MODE);
221 /* can't just use fetchmailhost here, it might be localhost */
222 strcat(daemon_name, host_fqdn());
224 /* we need only SMTP for this purpose */
225 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, NULL)) == -1
226 || SMTP_ok(sock) != SM_OK
227 || SMTP_helo(sock, fetchmailhost) != SM_OK
228 || SMTP_from(sock, daemon_name, (char *)NULL) != SM_OK
229 || SMTP_rcpt(sock, bounce_to) != SM_OK
230 || SMTP_data(sock) != SM_OK)
233 /* our first duty is to keep the sacred foo counters turning... */
235 snprintf(boundary, sizeof(boundary),
238 #endif /* HAVE_SNPRINTF */
239 "foo-mani-padme-hum-%d-%d-%ld",
240 (int)getpid(), (int)getppid(), time((time_t *)NULL));
242 if (outlevel >= O_VERBOSE)
243 report(stdout, GT_("SMTP: (bounce-message body)\n"));
245 /* this will usually go to sylog... */
246 report(stderr, GT_("mail from %s bounced to %s\n"),
247 daemon_name, bounce_to);
249 /* bouncemail headers */
250 SockPrintf(sock, "Return-Path: <>\r\n");
251 SockPrintf(sock, "From: %s\r\n", daemon_name);
252 SockPrintf(sock, "To: %s\r\n", bounce_to);
253 SockPrintf(sock, "MIME-Version: 1.0\r\n");
254 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
255 SockPrintf(sock, "\r\n");
257 /* RFC1892 part 1 -- human-readable message */
258 SockPrintf(sock, "--%s\r\n", boundary);
259 SockPrintf(sock,"Content-Type: text/plain\r\n");
260 SockPrintf(sock, "\r\n");
261 SockWrite(sock, message, strlen(message));
262 SockPrintf(sock, "\r\n");
263 SockPrintf(sock, "\r\n");
270 /* RFC1892 part 2 -- machine-readable responses */
271 SockPrintf(sock, "--%s\r\n", boundary);
272 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
273 SockPrintf(sock, "\r\n");
274 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fetchmailhost);
277 for (idp = msg->recipients; idp; idp = idp->next)
278 if (idp->val.status.mark == userclass)
281 /* Minimum RFC1894 compliance + Diagnostic-Code field */
282 SockPrintf(sock, "\r\n");
283 SockPrintf(sock, "Final-Recipient: rfc822; %s@%s\r\n",
284 idp->id, fetchmailhost);
285 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
286 SockPrintf(sock, "Action: failed\r\n");
289 /* one error applies to all users */
291 else if (nerrors > nusers)
293 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
297 /* errors correspond 1-1 to selected users */
298 error = errors[nusers++];
300 if (strlen(error) > 9 && isdigit(error[4])
301 && error[5] == '.' && isdigit(error[6])
302 && error[7] == '.' && isdigit(error[8]))
303 /* Enhanced status code available, use it */
304 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
306 /* Enhanced status code not available, fake one */
307 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
308 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
310 SockPrintf(sock, "\r\n");
313 /* RFC1892 part 3 -- headers of undelivered message */
314 SockPrintf(sock, "--%s\r\n", boundary);
315 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
316 SockPrintf(sock, "\r\n");
317 SockWrite(sock, msg->headers, strlen(msg->headers));
318 SockPrintf(sock, "\r\n");
319 SockPrintf(sock, "--%s--\r\n", boundary);
321 if (SMTP_eom(sock) != SM_OK || SMTP_quit(sock))
329 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
330 /* handle SMTP errors based on the content of SMTP_response */
331 /* return of PS_REFUSED deletes mail from the server; PS_TRANSIENT keeps it */
333 int smtperr = atoi(smtp_response);
336 xalloca(responses[0], char *, strlen(smtp_response)+1);
337 strcpy(responses[0], smtp_response);
341 * Don't do this! It can really mess you up if, for example, you're
342 * reporting an error with a single RCPT TO address among several;
343 * RSET discards the message body and it doesn't get sent to the
346 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
347 if (outlevel >= O_DEBUG)
348 report(stdout, GT_("Saved error is still %d\n"), smtperr);
349 #endif /* __UNUSED */
352 * Note: send_bouncemail message strings are not made subject
353 * to gettext translation because (a) they're going to be
354 * embedded in a text/plain 7bit part, and (b) they're
355 * going to be associated with listener error-response
356 * messages, which are probably in English (none of the
357 * MTAs I know about are internationalized).
359 if (str_find(&ctl->antispam, smtperr))
362 * SMTP listener explicitly refuses to deliver mail
363 * coming from this address, probably due to an
364 * anti-spam domain exclusion. Respect this. Don't
365 * try to ship the message, and don't prevent it from
366 * being deleted. There's no point in bouncing the
367 * email either since most spammers don't put their
368 * real return email address anywhere in the headers
369 * (unless the user insists with the SET SPAMBOUNCE
374 * 571 = sendmail's "unsolicited email refused"
375 * 550 = exim's new antispam response (temporary)
376 * 501 = exim's old antispam response
377 * 554 = Postfix antispam response.
381 send_bouncemail(ctl, msg, XMIT_ACCEPT,
382 "Our spam filter rejected this transaction.\r\n",
388 * Suppress error message only if the response specifically
389 * meant `excluded for policy reasons'. We *should* see
390 * an error when the return code is less specific.
393 report(stderr, GT_("%cMTP error: %s\n"),
399 case 552: /* message exceeds fixed maximum message size */
401 * Permanent no-go condition on the
402 * ESMTP server. Don't try to ship the message,
403 * and allow it to be deleted.
405 send_bouncemail(ctl, msg, XMIT_ACCEPT,
406 "This message was too large (SMTP error 552).\r\n",
408 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
410 case 553: /* invalid sending domain */
412 * These latter days 553 usually means a spammer is trying to
413 * cover his tracks. We never bouncemail on these, because
414 * (a) the return address is invalid by definition, and
415 * (b) we wouldn't want spammers to get confirmation that
416 * this address is live, anyway.
418 send_bouncemail(ctl, msg, XMIT_ACCEPT,
419 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
424 /* bounce non-transient errors back to the sender */
425 if (smtperr >= 500 && smtperr <= 599)
426 if (send_bouncemail(ctl, msg, XMIT_ACCEPT,
427 "General SMTP/ESMTP error.\r\n",
429 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
431 * We're going to end up here on 4xx errors, like:
433 * 451: temporarily unable to identify sender (exim)
434 * 452: temporary out-of-queue-space condition on the ESMTP server.
436 * These are temporary errors. Don't try to ship the message,
437 * and suppress deletion so it can be retried on a future
440 * Bouncemail *might* be appropriate here as a delay
441 * notification (note; if we ever add this, we must make
442 * sure the RFC1894 Action field is "delayed" rather thwn
443 * "failed"). But it's not really necessary because
444 * these are not actual failures, we're very likely to be
445 * able to recover on the next cycle.
447 return(PS_TRANSIENT);
451 /* these are shared by open_sink and stuffline */
454 int stuffline(struct query *ctl, char *buf)
455 /* ship a line to the given control block's output sink (SMTP server or MDA) */
460 /* The line may contain NUL characters. Find the last char to use
461 * -- the real line termination is the sequence "\n\0".
464 while ((last += strlen(last)) && (last[-1] != '\n'))
467 /* fix message lines that have only \n termination (for qmail) */
470 if (last - 1 == buf || last[-2] != '\r')
479 phase = FORWARDING_WAIT;
482 * SMTP byte-stuffing. We only do this if the protocol does *not*
483 * use .<CR><LF> as EOM. If it does, the server will already have
484 * decorated any . lines it sends back up.
488 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
493 /* writing to SMTP, leave the byte-stuffing in place */;
495 else /* if (!protocol->delimited) -- not byte-stuffed already */
498 SockWrite(ctl->smtp_socket, buf, 1); /* byte-stuff it */
500 /* leave it alone */;
504 /* we may need to strip carriage returns */
509 for (sp = tp = buf; sp < last; sp++)
517 if (ctl->mda || ctl->bsmtp)
518 n = fwrite(buf, 1, last - buf, sinkfp);
519 else if (ctl->smtp_socket != -1)
520 n = SockWrite(ctl->smtp_socket, buf, last - buf);
527 static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg,
528 int *good_addresses, int *bad_addresses)
529 /* open a BSMTP stream */
533 if (strcmp(ctl->bsmtp, "-") == 0)
536 sinkfp = fopen(ctl->bsmtp, "a");
538 /* see the ap computation under the SMTP branch */
540 "MAIL FROM: %s", (msg->return_path[0]) ? msg->return_path : user);
542 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
543 fputs(" BODY=8BITMIME", sinkfp);
544 else if (ctl->mimemsg & MSG_IS_7BIT)
545 fputs(" BODY=7BIT", sinkfp);
547 /* exim's BSMTP processor does not handle SIZE */
548 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
550 fprintf(sinkfp, "\r\n");
553 * RFC 1123 requires that the domain name part of the
554 * RCPT TO address be "canonicalized", that is a FQDN
555 * or MX but not a CNAME. Some listeners (like exim)
556 * enforce this. Now that we have the actual hostname,
557 * compute what we should canonicalize with.
559 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : "localhost";
562 for (idp = msg->recipients; idp; idp = idp->next)
563 if (idp->val.status.mark == XMIT_ACCEPT)
566 fprintf(sinkfp, "RCPT TO: %s\r\n", ctl->smtpname);
567 else if (strchr(idp->id, '@'))
569 "RCPT TO: %s\r\n", idp->id);
572 "RCPT TO: %s@%s\r\n", idp->id, ctl->destaddr);
576 fputs("DATA\r\n", sinkfp);
580 report(stderr, GT_("BSMTP file open or preamble write failed\n"));
587 /* this is experimental and will be removed if double bounces are reported */
588 #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS
590 static int open_smtp_sink(struct query *ctl, struct msgblk *msg,
591 int *good_addresses, int *bad_addresses)
592 /* open an SMTP stream */
596 char options[MSGBUFSIZE];
597 char addr[HOSTLEN+USERNAMELEN+1];
598 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
599 char **from_responses;
600 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
604 * Compute ESMTP options.
607 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
608 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
609 strcpy(options, " BODY=8BITMIME");
610 else if (ctl->mimemsg & MSG_IS_7BIT)
611 strcpy(options, " BODY=7BIT");
614 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
615 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
618 * Try to get the SMTP listener to take the Return-Path
619 * address as MAIL FROM. If it won't, fall back on the
620 * remotename and mailserver host. This won't affect replies,
621 * which use the header From address anyway; the MAIL FROM
622 * address is a place for the SMTP listener to send
623 * bouncemail. The point is to guarantee a FQDN in the MAIL
624 * FROM line -- some SMTP listeners, like smail, become
627 * RFC 1123 requires that the domain name part of the
628 * MAIL FROM address be "canonicalized", that is a
629 * FQDN or MX but not a CNAME. We'll assume the Return-Path
630 * header is already in this form here (it certainly
631 * is if rewrite is on). RFC 1123 is silent on whether
632 * a nonexistent hostname part is considered canonical.
634 * This is a potential problem if the MTAs further upstream
635 * didn't pass canonicalized From/Return-Path lines, *and* the
636 * local SMTP listener insists on them.
638 * Handle the case where an upstream MTA is setting a return
639 * path equal to "@". Ghod knows why anyone does this, but
640 * it's been reported to happen in mail from Amazon.com and
643 if (!msg->return_path[0] || (0 == strcmp(msg->return_path, "@")))
646 snprintf(addr, sizeof(addr),
649 #endif /* HAVE_SNPRINTF */
650 "%s@%s", ctl->remotename, ctl->server.truename);
653 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
654 ap = msg->return_path;
655 else /* in case Return-Path existed but was local */
658 snprintf(addr, sizeof(addr),
661 #endif /* HAVE_SNPRINTF */
662 "%s@%s", msg->return_path, ctl->server.truename);
666 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
668 int err = handle_smtp_report(ctl, msg);
670 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
675 * Now list the recipient addressees
678 for (idp = msg->recipients; idp; idp = idp->next)
680 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
681 xalloca(from_responses, char **, sizeof(char *) * total_addresses);
682 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
683 for (idp = msg->recipients; idp; idp = idp->next)
684 if (idp->val.status.mark == XMIT_ACCEPT)
686 if (strchr(idp->id, '@'))
687 strcpy(addr, idp->id);
691 snprintf(addr, sizeof(addr)-1, "%s", ctl->smtpname);
693 sprintf(addr, "%s", ctl->smtpname);
694 #endif /* HAVE_SNPRINTF */
698 snprintf(addr, sizeof(addr)-1, "%s@%s", idp->id, ctl->destaddr);
700 sprintf(addr, "%s@%s", idp->id, ctl->destaddr);
701 #endif /* HAVE_SNPRINTF */
704 if (SMTP_rcpt(ctl->smtp_socket, addr) == SM_OK)
708 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
709 char errbuf[POPBUFSIZE];
710 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
711 handle_smtp_report(ctl, msg);
713 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
715 snprintf(errbuf, sizeof(errbuf), "%s: %s",
716 idp->id, smtp_response);
718 strncpy(errbuf, idp->id, sizeof(errbuf));
719 strcat(errbuf, ": ");
720 strcat(errbuf, smtp_response);
721 #endif /* HAVE_SNPRINTF */
723 xalloca(from_responses[*bad_addresses],
726 strcpy(from_responses[*bad_addresses], errbuf);
727 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
730 idp->val.status.mark = XMIT_RCPTBAD;
731 if (outlevel >= O_VERBOSE)
733 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
734 ctl->listener, addr);
738 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
740 * This should not be necessary, because the SMTP listener itself
741 * should genrate a bounce for the bad address.
744 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
745 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
746 *bad_addresses, from_responses);
747 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
750 * It's tempting to do local notification only if bouncemail was
751 * insufficient -- that is, to add && total_addresses > *bad_addresses
752 * to the test here. The problem with this theory is that it would
753 * make initial diagnosis of a broken multidrop configuration very
754 * hard -- most single-recipient messages would just invisibly bounce.
756 if (!(*good_addresses))
758 if (!run.postmaster[0])
760 if (outlevel >= O_VERBOSE)
761 report(stderr, GT_("no address matches; no postmaster set.\n"));
762 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
765 if (strchr(run.postmaster, '@'))
766 strncpy(addr, run.postmaster, sizeof(addr));
770 snprintf(addr, sizeof(addr)-1, "%s@%s", run.postmaster, ctl->destaddr);
772 sprintf(addr, "%s@%s", run.postmaster, ctl->destaddr);
773 #endif /* HAVE_SNPRINTF */
776 if (SMTP_rcpt(ctl->smtp_socket, addr) != SM_OK)
778 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
779 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
783 if (outlevel >= O_VERBOSE)
784 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
788 * Tell the listener we're ready to send data.
789 * Some listeners (like zmailer) may return antispam errors here.
791 if (SMTP_data(ctl->smtp_socket) != SM_OK)
793 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
794 return(handle_smtp_report(ctl, msg));
800 static int open_mda_sink(struct query *ctl, struct msgblk *msg,
801 int *good_addresses, int *bad_addresses)
802 /* open a stream to a local MDA */
804 #ifdef HAVE_SIGACTION
805 struct sigaction sa_new;
806 #endif /* HAVE_SIGACTION */
808 int length = 0, fromlen = 0, nameslen = 0;
809 char *names = NULL, *before, *after, *from = NULL;
811 ctl->destaddr = "localhost";
813 for (idp = msg->recipients; idp; idp = idp->next)
814 if (idp->val.status.mark == XMIT_ACCEPT)
817 length = strlen(ctl->mda);
818 before = xstrdup(ctl->mda);
820 /* get user addresses for %T (or %s for backward compatibility) */
821 if (strstr(before, "%s") || strstr(before, "%T"))
824 * We go through this in order to be able to handle very
825 * long lists of users and (re)implement %s.
828 for (idp = msg->recipients; idp; idp = idp->next)
829 if ((idp->val.status.mark == XMIT_ACCEPT))
830 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
831 if ((*good_addresses == 0))
832 nameslen = strlen(run.postmaster);
834 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
835 if (*good_addresses == 0)
836 strcpy(names, run.postmaster);
840 for (idp = msg->recipients; idp; idp = idp->next)
841 if (idp->val.status.mark == XMIT_ACCEPT)
843 strcat(names, idp->id);
846 names[--nameslen] = '\0'; /* chop trailing space */
849 /* sanitize names in order to contain only harmless shell chars */
853 /* get From address for %F */
854 if (strstr(before, "%F"))
856 from = xstrdup(msg->return_path);
858 /* sanitize from in order to contain *only* harmless shell chars */
861 fromlen = strlen(from);
864 /* do we have to build an mda string? */
869 /* find length of resulting mda string */
871 while ((sp = strstr(sp, "%s"))) {
872 length += nameslen - 2; /* subtract %s */
876 while ((sp = strstr(sp, "%T"))) {
877 length += nameslen - 2; /* subtract %T */
881 while ((sp = strstr(sp, "%F"))) {
882 length += fromlen - 2; /* subtract %F */
886 after = xmalloc(length + 1);
888 /* copy mda source string to after, while expanding %[sTF] */
889 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
890 if (sp[0] != '%') continue;
892 /* need to expand? BTW, no here overflow, because in
893 ** the worst case (end of string) sp[1] == '\0' */
894 if (sp[1] == 's' || sp[1] == 'T') {
897 sp++; /* position sp over [sT] */
898 dp--; /* adjust dp */
899 } else if (sp[1] == 'F') {
902 sp++; /* position sp over F */
903 dp--; /* adjust dp */
922 if (outlevel >= O_DEBUG)
923 report(stdout, GT_("about to deliver with: %s\n"), before);
927 * Arrange to run with user's permissions if we're root.
928 * This will initialize the ownership of any files the
929 * MDA creates properly. (The seteuid call is available
930 * under all BSDs and Linux)
933 #endif /* HAVE_SETEUID */
935 sinkfp = popen(before, "w");
940 /* this will fail quietly if we didn't start as root */
942 #endif /* HAVE_SETEUID */
946 report(stderr, GT_("MDA open failed\n"));
951 * We need to disable the normal SIGCHLD handling here because
952 * sigchld_handler() would reap away the error status, returning
953 * error status instead of 0 for successful completion.
955 #ifndef HAVE_SIGACTION
956 signal(SIGCHLD, SIG_DFL);
958 memset (&sa_new, 0, sizeof sa_new);
959 sigemptyset (&sa_new.sa_mask);
960 sa_new.sa_handler = SIG_DFL;
961 sigaction (SIGCHLD, &sa_new, NULL);
962 #endif /* HAVE_SIGACTION */
967 int open_sink(struct query *ctl, struct msgblk *msg,
968 int *good_addresses, int *bad_addresses)
969 /* set up sinkfp to be an input sink we can ship a message to */
971 *bad_addresses = *good_addresses = 0;
973 if (ctl->bsmtp) /* dump to a BSMTP batch file */
974 return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses));
976 * Try to forward to an SMTP or LMTP listener. If the attempt to
977 * open a socket fails, fall through to attempt delivery via
980 else if (!ctl->mda && smtp_open(ctl) != -1)
981 return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses));
984 * Awkward case. User didn't specify an MDA. Our attempt to get a
985 * listener socket failed. Try to cope anyway -- initial configuration
986 * may have found procmail.
990 report(stderr, GT_("%cMTP connect to %s failed\n"),
992 ctl->smtphost ? ctl->smtphost : "localhost");
995 /* No fallback MDA declared. Bail out. */
999 * If user had things set up to forward offsite, no way
1000 * we want to deliver locally!
1002 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
1006 * User was delivering locally. We have a fallback MDA.
1007 * Latch it in place, logging the error, and fall through.
1009 ctl->mda = FALLBACK_MDA;
1011 report(stderr, GT_("can't raise the listener; falling back to %s"),
1016 if (ctl->mda) /* must deliver through an MDA */
1017 return(open_mda_sink(ctl, msg, good_addresses, bad_addresses));
1020 * We need to stash this away in order to know how many
1021 * response lines to expect after the LMTP end-of-message.
1023 lmtp_responses = *good_addresses;
1028 void release_sink(struct query *ctl)
1029 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1031 if (ctl->bsmtp && sinkfp)
1038 sinkfp = (FILE *)NULL;
1040 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1044 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1045 /* perform end-of-message actions on the current output sink */
1051 /* close the delivery pipe, we'll reopen before next message */
1054 rc = pclose(sinkfp);
1055 sinkfp = (FILE *)NULL;
1060 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1065 GT_("MDA returned nonzero status %d\n"), rc);
1069 else if (ctl->bsmtp && sinkfp)
1073 /* implicit disk-full check here... */
1074 fputs(".\r\n", sinkfp);
1075 error = ferror(sinkfp);
1076 if (strcmp(ctl->bsmtp, "-"))
1077 if (fclose(sinkfp) == EOF) error = 1;
1081 GT_("Message termination or close of BSMTP file failed\n"));
1087 /* write message terminator */
1088 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1090 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1092 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1097 report(stderr, GT_("SMTP listener refused delivery\n"));
1098 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1104 * If this is an SMTP connection, SMTP_eom() ate the response.
1105 * But could be this is an LMTP connection, in which case we have to
1106 * interpret either (a) a single 503 response meaning there
1107 * were no successful RCPT TOs, or (b) a variable number of
1108 * responses, one for each successful RCPT TO. We need to send
1109 * bouncemail on each failed response and then return TRUE anyway,
1110 * otherwise the message will get left in the queue and resent
1111 * to people who got it the first time.
1113 if (ctl->listener == LMTP_MODE)
1115 if (lmtp_responses == 0)
1117 SMTP_ok(ctl->smtp_socket);
1120 * According to RFC2033, 503 is the only legal response
1121 * if no RCPT TO commands succeeded. No error recovery
1122 * is really possible here, as we have no idea what
1123 * insane thing the listener might be doing if it doesn't
1126 if (atoi(smtp_response) == 503)
1127 report(stderr, GT_("LMTP delivery error on EOM\n"));
1130 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1134 * It's not completely clear what to do here. We choose to
1135 * interpret delivery failure here as a transient error,
1136 * the same way SMTP delivery failure is handled. If we're
1137 * wrong, an undead message will get stuck in the queue.
1146 /* eat the RFC2033-required responses, saving errors */
1147 xalloca(responses, char **, sizeof(char *) * lmtp_responses);
1148 for (errors = i = 0; i < lmtp_responses; i++)
1150 if (SMTP_ok(ctl->smtp_socket) == SM_OK)
1151 responses[i] = (char *)NULL;
1154 xalloca(responses[errors],
1156 strlen(smtp_response)+1);
1157 strcpy(responses[errors], smtp_response);
1163 return(TRUE); /* all deliveries succeeded */
1166 * One or more deliveries failed.
1167 * If we can bounce a failures list back to the
1168 * sender, and the postmaster does not want to
1169 * deal with the bounces return TRUE, deleting the
1170 * message from the server so it won't be
1171 * re-forwarded on subsequent poll cycles.
1173 return(send_bouncemail(ctl, msg, XMIT_ACCEPT,
1174 "LSMTP partial delivery failure.\r\n",
1175 errors, responses));
1183 int open_warning_by_mail(struct query *ctl, struct msgblk *msg)
1184 /* set up output sink for a mailed warning to calling user */
1189 * Dispatching warning email is a little complicated. The problem is
1190 * that we have to deal with three distinct cases:
1192 * 1. Single-drop running from user account. Warning mail should
1193 * go to the local name for which we're collecting (coincides
1194 * with calling user).
1196 * 2. Single-drop running from root or other privileged ID, with rc
1197 * file generated on the fly (Ken Estes's weird setup...) Mail
1198 * should go to the local name for which we're collecting (does not
1199 * coincide with calling user).
1201 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1202 * member null so this message will fall through to run.postmaster.
1204 * The zero in the reallen element means we won't pass a SIZE
1205 * option to ESMTP; the message length would be more trouble than
1206 * it's worth to compute.
1208 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0};
1211 strcat(reply.return_path, fetchmailhost);
1213 if (!MULTIDROP(ctl)) /* send to calling user */
1215 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1216 status = open_sink(ctl, &reply, &good, &bad);
1217 free_str_list(&reply.recipients);
1219 else /* send to postmaster */
1220 status = open_sink(ctl, &reply, &good, &bad);
1221 stuff_warning(ctl, "Date: %s", rfc822timestamp());
1225 #if defined(HAVE_STDARG_H)
1226 void stuff_warning(struct query *ctl, const char *fmt, ... )
1228 void stuff_warning(struct query *ctl, fmt, va_alist)
1230 const char *fmt; /* printf-style format */
1233 /* format and ship a warning message line by mail */
1235 char buf[POPBUFSIZE];
1239 * stuffline() requires its input to be writeable (for CR stripping),
1240 * so we needed to copy the message to a writeable buffer anyway in
1241 * case it was a string constant. We make a virtue of that necessity
1242 * here by supporting stdargs/varargs.
1244 #if defined(HAVE_STDARG_H)
1249 #ifdef HAVE_VSNPRINTF
1250 vsnprintf(buf, sizeof(buf), fmt, ap);
1252 vsprintf(buf, fmt, ap);
1256 #ifdef HAVE_SNPRINTF
1257 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1259 strcat(buf, "\r\n");
1260 #endif /* HAVE_SNPRINTF */
1262 stuffline(ctl, buf);
1265 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1266 /* sign and send mailed warnings */
1268 stuff_warning(ctl, GT_("--\r\n\t\t\t\tThe Fetchmail Daemon\r\n"));
1269 close_sink(ctl, msg, TRUE);
1272 /* sink.c ends here */