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)
146 return(ctl->smtp_socket); /* success */
148 /* are we doing SMTP or LMTP? */
149 SMTP_setmode(ctl->listener);
151 /* first, probe for ESMTP */
152 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
153 SMTP_ehlo(ctl->smtp_socket, id_me,
154 &ctl->server.esmtp_options) == SM_OK)
158 * RFC 1869 warns that some listeners hang up on a failed EHLO,
159 * so it's safest not to assume the socket will still be good.
163 /* if opening for ESMTP failed, try SMTP */
164 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL,
165 ctl->server.plugout)) == -1)
168 if (SMTP_ok(ctl->smtp_socket) == SM_OK &&
169 SMTP_helo(ctl->smtp_socket, id_me) == SM_OK)
179 * RFC 1123 requires that the domain name part of the
180 * RCPT TO address be "canonicalized", that is a FQDN
181 * or MX but not a CNAME. Some listeners (like exim)
182 * enforce this. Now that we have the actual hostname,
183 * compute what we should canonicalize with.
185 * make sure we do not forget to drop the /port if
188 if (ctl->listener == LMTP_MODE && !ctl->smtpaddress)
190 if (parsed_host && parsed_host[0] != 0)
191 ctl->destaddr = xstrdup(parsed_host);
193 ctl->destaddr = (ctl->smtphost && ctl->smtphost[0] != '/') ? ctl->smtphost : "localhost";
196 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : ( ctl->smtphost && ctl->smtphost[0] != '/' ? ctl->smtphost : "localhost");
198 if (outlevel >= O_DEBUG && ctl->smtp_socket != -1)
199 report(stdout, GT_("forwarding to %s\n"), ctl->smtphost);
201 return(ctl->smtp_socket);
204 static void sanitize(char *s)
205 /* replace unsafe shellchars by an _ */
207 const static char *ok_chars = " 1234567890!@%-_=+:,./abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
210 for (cp = s; *(cp += strspn(cp, ok_chars)); /* NO INCREMENT */)
214 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
215 int userclass, char *message,
216 int nerrors, char *errors[])
217 /* bounce back an error report a la RFC 1892 */
219 char daemon_name[18 + HOSTLEN] = "FETCHMAIL-DAEMON@";
220 char boundary[BUFSIZ], *bounce_to;
223 /* don't bounce in reply to undeliverable bounces */
224 if (!msg->return_path[0] || strcmp(msg->return_path, "<>") == 0)
227 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
229 SMTP_setmode(SMTP_MODE);
231 /* can't just use fetchmailhost here, it might be localhost */
232 strcat(daemon_name, host_fqdn());
234 /* we need only SMTP for this purpose */
235 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, NULL)) == -1
236 || SMTP_ok(sock) != SM_OK
237 || SMTP_helo(sock, fetchmailhost) != SM_OK
238 || SMTP_from(sock, daemon_name, (char *)NULL) != SM_OK
239 || SMTP_rcpt(sock, bounce_to) != SM_OK
240 || SMTP_data(sock) != SM_OK)
243 /* our first duty is to keep the sacred foo counters turning... */
245 snprintf(boundary, sizeof(boundary),
248 #endif /* HAVE_SNPRINTF */
249 "foo-mani-padme-hum-%d-%d-%ld",
250 (int)getpid(), (int)getppid(), time((time_t *)NULL));
252 if (outlevel >= O_VERBOSE)
253 report(stdout, GT_("SMTP: (bounce-message body)\n"));
255 /* this will usually go to sylog... */
256 report(stderr, GT_("mail from %s bounced to %s\n"),
257 daemon_name, bounce_to);
259 /* bouncemail headers */
260 SockPrintf(sock, "Return-Path: <>\r\n");
261 SockPrintf(sock, "From: %s\r\n", daemon_name);
262 SockPrintf(sock, "To: %s\r\n", bounce_to);
263 SockPrintf(sock, "MIME-Version: 1.0\r\n");
264 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
265 SockPrintf(sock, "\r\n");
267 /* RFC1892 part 1 -- human-readable message */
268 SockPrintf(sock, "--%s\r\n", boundary);
269 SockPrintf(sock,"Content-Type: text/plain\r\n");
270 SockPrintf(sock, "\r\n");
271 SockWrite(sock, message, strlen(message));
272 SockPrintf(sock, "\r\n");
273 SockPrintf(sock, "\r\n");
280 /* RFC1892 part 2 -- machine-readable responses */
281 SockPrintf(sock, "--%s\r\n", boundary);
282 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
283 SockPrintf(sock, "\r\n");
284 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fetchmailhost);
287 for (idp = msg->recipients; idp; idp = idp->next)
288 if (idp->val.status.mark == userclass)
291 /* Minimum RFC1894 compliance + Diagnostic-Code field */
292 SockPrintf(sock, "\r\n");
293 SockPrintf(sock, "Final-Recipient: rfc822; %s@%s\r\n",
294 idp->id, fetchmailhost);
295 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
296 SockPrintf(sock, "Action: failed\r\n");
299 /* one error applies to all users */
301 else if (nerrors > nusers)
303 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
307 /* errors correspond 1-1 to selected users */
308 error = errors[nusers++];
310 if (strlen(error) > 9 && isdigit(error[4])
311 && error[5] == '.' && isdigit(error[6])
312 && error[7] == '.' && isdigit(error[8]))
313 /* Enhanced status code available, use it */
314 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
316 /* Enhanced status code not available, fake one */
317 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
318 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
320 SockPrintf(sock, "\r\n");
323 /* RFC1892 part 3 -- headers of undelivered message */
324 SockPrintf(sock, "--%s\r\n", boundary);
325 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
326 SockPrintf(sock, "\r\n");
327 SockWrite(sock, msg->headers, strlen(msg->headers));
328 SockPrintf(sock, "\r\n");
329 SockPrintf(sock, "--%s--\r\n", boundary);
331 if (SMTP_eom(sock) != SM_OK || SMTP_quit(sock))
339 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
340 /* handle SMTP errors based on the content of SMTP_response */
341 /* return of PS_REFUSED deletes mail from the server; PS_TRANSIENT keeps it */
343 int smtperr = atoi(smtp_response);
346 xalloca(responses[0], char *, strlen(smtp_response)+1);
347 strcpy(responses[0], smtp_response);
351 * Don't do this! It can really mess you up if, for example, you're
352 * reporting an error with a single RCPT TO address among several;
353 * RSET discards the message body and it doesn't get sent to the
356 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
357 if (outlevel >= O_DEBUG)
358 report(stdout, GT_("Saved error is still %d\n"), smtperr);
359 #endif /* __UNUSED */
362 * Note: send_bouncemail message strings are not made subject
363 * to gettext translation because (a) they're going to be
364 * embedded in a text/plain 7bit part, and (b) they're
365 * going to be associated with listener error-response
366 * messages, which are probably in English (none of the
367 * MTAs I know about are internationalized).
369 if (str_find(&ctl->antispam, smtperr))
372 * SMTP listener explicitly refuses to deliver mail
373 * coming from this address, probably due to an
374 * anti-spam domain exclusion. Respect this. Don't
375 * try to ship the message, and don't prevent it from
376 * being deleted. There's no point in bouncing the
377 * email either since most spammers don't put their
378 * real return email address anywhere in the headers
379 * (unless the user insists with the SET SPAMBOUNCE
384 * 571 = sendmail's "unsolicited email refused"
385 * 550 = exim's new antispam response (temporary)
386 * 501 = exim's old antispam response
387 * 554 = Postfix antispam response.
391 send_bouncemail(ctl, msg, XMIT_ACCEPT,
392 "Our spam filter rejected this transaction.\r\n",
398 * Suppress error message only if the response specifically
399 * meant `excluded for policy reasons'. We *should* see
400 * an error when the return code is less specific.
403 report(stderr, GT_("%cMTP error: %s\n"),
409 case 552: /* message exceeds fixed maximum message size */
411 * Permanent no-go condition on the
412 * ESMTP server. Don't try to ship the message,
413 * and allow it to be deleted.
416 send_bouncemail(ctl, msg, XMIT_ACCEPT,
417 "This message was too large (SMTP error 552).\r\n",
421 case 553: /* invalid sending domain */
423 * These latter days 553 usually means a spammer is trying to
424 * cover his tracks. We never bouncemail on these, because
425 * (a) the return address is invalid by definition, and
426 * (b) we wouldn't want spammers to get confirmation that
427 * this address is live, anyway.
429 #ifdef __DONT_FEED_THE_SPAMMERS__
431 send_bouncemail(ctl, msg, XMIT_ACCEPT,
432 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
434 #endif /* __DONT_FEED_THE_SPAMMERS__ */
438 /* bounce non-transient errors back to the sender */
439 if (smtperr >= 500 && smtperr <= 599)
440 if (send_bouncemail(ctl, msg, XMIT_ACCEPT,
441 "General SMTP/ESMTP error.\r\n",
443 return(run.bouncemail ? PS_REFUSED : PS_TRANSIENT);
445 * We're going to end up here on 4xx errors, like:
447 * 451: temporarily unable to identify sender (exim)
448 * 452: temporary out-of-queue-space condition on the ESMTP server.
450 * These are temporary errors. Don't try to ship the message,
451 * and suppress deletion so it can be retried on a future
454 * Bouncemail *might* be appropriate here as a delay
455 * notification (note; if we ever add this, we must make
456 * sure the RFC1894 Action field is "delayed" rather than
457 * "failed"). But it's not really necessary because
458 * these are not actual failures, we're very likely to be
459 * able to recover on the next cycle.
461 return(PS_TRANSIENT);
465 /* these are shared by open_sink and stuffline */
468 int stuffline(struct query *ctl, char *buf)
469 /* ship a line to the given control block's output sink (SMTP server or MDA) */
474 /* The line may contain NUL characters. Find the last char to use
475 * -- the real line termination is the sequence "\n\0".
478 while ((last += strlen(last)) && (last[-1] != '\n'))
481 /* fix message lines that have only \n termination (for qmail) */
484 if (last - 1 == buf || last[-2] != '\r')
493 phase = FORWARDING_WAIT;
496 * SMTP byte-stuffing. We only do this if the protocol does *not*
497 * use .<CR><LF> as EOM. If it does, the server will already have
498 * decorated any . lines it sends back up.
502 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
507 /* writing to SMTP, leave the byte-stuffing in place */;
509 else /* if (!protocol->delimited) -- not byte-stuffed already */
512 SockWrite(ctl->smtp_socket, buf, 1); /* byte-stuff it */
514 /* leave it alone */;
518 /* we may need to strip carriage returns */
523 for (sp = tp = buf; sp < last; sp++)
531 if (ctl->mda || ctl->bsmtp)
532 n = fwrite(buf, 1, last - buf, sinkfp);
533 else if (ctl->smtp_socket != -1)
534 n = SockWrite(ctl->smtp_socket, buf, last - buf);
541 static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg,
542 int *good_addresses, int *bad_addresses)
543 /* open a BSMTP stream */
547 if (strcmp(ctl->bsmtp, "-") == 0)
550 sinkfp = fopen(ctl->bsmtp, "a");
552 /* see the ap computation under the SMTP branch */
554 "MAIL FROM: %s", (msg->return_path[0]) ? msg->return_path : user);
556 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
557 fputs(" BODY=8BITMIME", sinkfp);
558 else if (ctl->mimemsg & MSG_IS_7BIT)
559 fputs(" BODY=7BIT", sinkfp);
561 /* exim's BSMTP processor does not handle SIZE */
562 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
564 fprintf(sinkfp, "\r\n");
567 * RFC 1123 requires that the domain name part of the
568 * RCPT TO address be "canonicalized", that is a FQDN
569 * or MX but not a CNAME. Some listeners (like exim)
570 * enforce this. Now that we have the actual hostname,
571 * compute what we should canonicalize with.
573 ctl->destaddr = ctl->smtpaddress ? ctl->smtpaddress : "localhost";
576 for (idp = msg->recipients; idp; idp = idp->next)
577 if (idp->val.status.mark == XMIT_ACCEPT)
580 fprintf(sinkfp, "RCPT TO: %s\r\n", ctl->smtpname);
581 else if (strchr(idp->id, '@'))
583 "RCPT TO: %s\r\n", idp->id);
586 "RCPT TO: %s@%s\r\n", idp->id, ctl->destaddr);
590 fputs("DATA\r\n", sinkfp);
594 report(stderr, GT_("BSMTP file open or preamble write failed\n"));
601 /* this is experimental and will be removed if double bounces are reported */
602 #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS
604 static int open_smtp_sink(struct query *ctl, struct msgblk *msg,
605 int *good_addresses, int *bad_addresses)
606 /* open an SMTP stream */
610 char options[MSGBUFSIZE];
611 char addr[HOSTLEN+USERNAMELEN+1];
612 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
613 char **from_responses;
614 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
618 * Compute ESMTP options.
621 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
622 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
623 strcpy(options, " BODY=8BITMIME");
624 else if (ctl->mimemsg & MSG_IS_7BIT)
625 strcpy(options, " BODY=7BIT");
628 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
629 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
632 * Try to get the SMTP listener to take the Return-Path
633 * address as MAIL FROM. If it won't, fall back on the
634 * remotename and mailserver host. This won't affect replies,
635 * which use the header From address anyway; the MAIL FROM
636 * address is a place for the SMTP listener to send
637 * bouncemail. The point is to guarantee a FQDN in the MAIL
638 * FROM line -- some SMTP listeners, like smail, become
641 * RFC 1123 requires that the domain name part of the
642 * MAIL FROM address be "canonicalized", that is a
643 * FQDN or MX but not a CNAME. We'll assume the Return-Path
644 * header is already in this form here (it certainly
645 * is if rewrite is on). RFC 1123 is silent on whether
646 * a nonexistent hostname part is considered canonical.
648 * This is a potential problem if the MTAs further upstream
649 * didn't pass canonicalized From/Return-Path lines, *and* the
650 * local SMTP listener insists on them.
652 * Handle the case where an upstream MTA is setting a return
653 * path equal to "@". Ghod knows why anyone does this, but
654 * it's been reported to happen in mail from Amazon.com and
657 if (!msg->return_path[0] || (0 == strcmp(msg->return_path, "@")))
660 snprintf(addr, sizeof(addr),
663 #endif /* HAVE_SNPRINTF */
664 "%s@%s", ctl->remotename, ctl->server.truename);
667 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
668 ap = msg->return_path;
669 else /* in case Return-Path existed but was local */
672 snprintf(addr, sizeof(addr),
675 #endif /* HAVE_SNPRINTF */
676 "%s@%s", msg->return_path, ctl->server.truename);
680 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
682 int err = handle_smtp_report(ctl, msg);
684 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
689 * Now list the recipient addressees
692 for (idp = msg->recipients; idp; idp = idp->next)
694 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
695 xalloca(from_responses, char **, sizeof(char *) * total_addresses);
696 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
697 for (idp = msg->recipients; idp; idp = idp->next)
698 if (idp->val.status.mark == XMIT_ACCEPT)
700 if (strchr(idp->id, '@'))
701 strcpy(addr, idp->id);
705 snprintf(addr, sizeof(addr)-1, "%s", ctl->smtpname);
707 sprintf(addr, "%s", ctl->smtpname);
708 #endif /* HAVE_SNPRINTF */
712 snprintf(addr, sizeof(addr)-1, "%s@%s", idp->id, ctl->destaddr);
714 sprintf(addr, "%s@%s", idp->id, ctl->destaddr);
715 #endif /* HAVE_SNPRINTF */
718 if (SMTP_rcpt(ctl->smtp_socket, addr) == SM_OK)
722 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
723 char errbuf[POPBUFSIZE];
724 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
725 handle_smtp_report(ctl, msg);
727 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
729 snprintf(errbuf, sizeof(errbuf), "%s: %s",
730 idp->id, smtp_response);
732 strncpy(errbuf, idp->id, sizeof(errbuf));
733 strcat(errbuf, ": ");
734 strcat(errbuf, smtp_response);
735 #endif /* HAVE_SNPRINTF */
737 xalloca(from_responses[*bad_addresses],
740 strcpy(from_responses[*bad_addresses], errbuf);
741 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
744 idp->val.status.mark = XMIT_RCPTBAD;
745 if (outlevel >= O_VERBOSE)
747 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
748 ctl->listener, addr);
752 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
754 * This should not be necessary, because the SMTP listener itself
755 * should genrate a bounce for the bad address.
758 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
759 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
760 *bad_addresses, from_responses);
761 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
764 * It's tempting to do local notification only if bouncemail was
765 * insufficient -- that is, to add && total_addresses > *bad_addresses
766 * to the test here. The problem with this theory is that it would
767 * make initial diagnosis of a broken multidrop configuration very
768 * hard -- most single-recipient messages would just invisibly bounce.
770 if (!(*good_addresses))
772 if (!run.postmaster[0])
774 if (outlevel >= O_VERBOSE)
775 report(stderr, GT_("no address matches; no postmaster set.\n"));
776 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
779 if (strchr(run.postmaster, '@'))
780 strncpy(addr, run.postmaster, sizeof(addr));
784 snprintf(addr, sizeof(addr)-1, "%s@%s", run.postmaster, ctl->destaddr);
786 sprintf(addr, "%s@%s", run.postmaster, ctl->destaddr);
787 #endif /* HAVE_SNPRINTF */
790 if (SMTP_rcpt(ctl->smtp_socket, addr) != SM_OK)
792 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
793 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
797 if (outlevel >= O_VERBOSE)
798 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
802 * Tell the listener we're ready to send data.
803 * Some listeners (like zmailer) may return antispam errors here.
805 if (SMTP_data(ctl->smtp_socket) != SM_OK)
807 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
808 return(handle_smtp_report(ctl, msg));
812 * We need to stash this away in order to know how many
813 * response lines to expect after the LMTP end-of-message.
815 lmtp_responses = *good_addresses;
820 static int open_mda_sink(struct query *ctl, struct msgblk *msg,
821 int *good_addresses, int *bad_addresses)
822 /* open a stream to a local MDA */
824 #ifdef HAVE_SIGACTION
825 struct sigaction sa_new;
826 #endif /* HAVE_SIGACTION */
828 int length = 0, fromlen = 0, nameslen = 0;
829 char *names = NULL, *before, *after, *from = NULL;
831 ctl->destaddr = "localhost";
833 for (idp = msg->recipients; idp; idp = idp->next)
834 if (idp->val.status.mark == XMIT_ACCEPT)
837 length = strlen(ctl->mda);
838 before = xstrdup(ctl->mda);
840 /* get user addresses for %T (or %s for backward compatibility) */
841 if (strstr(before, "%s") || strstr(before, "%T"))
844 * We go through this in order to be able to handle very
845 * long lists of users and (re)implement %s.
848 for (idp = msg->recipients; idp; idp = idp->next)
849 if ((idp->val.status.mark == XMIT_ACCEPT))
850 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
851 if ((*good_addresses == 0))
852 nameslen = strlen(run.postmaster);
854 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
855 if (*good_addresses == 0)
856 strcpy(names, run.postmaster);
860 for (idp = msg->recipients; idp; idp = idp->next)
861 if (idp->val.status.mark == XMIT_ACCEPT)
863 strcat(names, idp->id);
866 names[--nameslen] = '\0'; /* chop trailing space */
869 /* sanitize names in order to contain only harmless shell chars */
873 /* get From address for %F */
874 if (strstr(before, "%F"))
876 from = xstrdup(msg->return_path);
878 /* sanitize from in order to contain *only* harmless shell chars */
881 fromlen = strlen(from);
884 /* do we have to build an mda string? */
889 /* find length of resulting mda string */
891 while ((sp = strstr(sp, "%s"))) {
892 length += nameslen - 2; /* subtract %s */
896 while ((sp = strstr(sp, "%T"))) {
897 length += nameslen - 2; /* subtract %T */
901 while ((sp = strstr(sp, "%F"))) {
902 length += fromlen - 2; /* subtract %F */
906 after = xmalloc(length + 1);
908 /* copy mda source string to after, while expanding %[sTF] */
909 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
910 if (sp[0] != '%') continue;
912 /* need to expand? BTW, no here overflow, because in
913 ** the worst case (end of string) sp[1] == '\0' */
914 if (sp[1] == 's' || sp[1] == 'T') {
917 sp++; /* position sp over [sT] */
918 dp--; /* adjust dp */
919 } else if (sp[1] == 'F') {
922 sp++; /* position sp over F */
923 dp--; /* adjust dp */
942 if (outlevel >= O_DEBUG)
943 report(stdout, GT_("about to deliver with: %s\n"), before);
947 * Arrange to run with user's permissions if we're root.
948 * This will initialize the ownership of any files the
949 * MDA creates properly. (The seteuid call is available
950 * under all BSDs and Linux)
953 #endif /* HAVE_SETEUID */
955 sinkfp = popen(before, "w");
960 /* this will fail quietly if we didn't start as root */
962 #endif /* HAVE_SETEUID */
966 report(stderr, GT_("MDA open failed\n"));
971 * We need to disable the normal SIGCHLD handling here because
972 * sigchld_handler() would reap away the error status, returning
973 * error status instead of 0 for successful completion.
975 #ifndef HAVE_SIGACTION
976 signal(SIGCHLD, SIG_DFL);
978 memset (&sa_new, 0, sizeof sa_new);
979 sigemptyset (&sa_new.sa_mask);
980 sa_new.sa_handler = SIG_DFL;
981 sigaction (SIGCHLD, &sa_new, NULL);
982 #endif /* HAVE_SIGACTION */
987 int open_sink(struct query *ctl, struct msgblk *msg,
988 int *good_addresses, int *bad_addresses)
989 /* set up sinkfp to be an input sink we can ship a message to */
991 *bad_addresses = *good_addresses = 0;
993 if (ctl->bsmtp) /* dump to a BSMTP batch file */
994 return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses));
996 * Try to forward to an SMTP or LMTP listener. If the attempt to
997 * open a socket fails, fall through to attempt delivery via
1000 else if (!ctl->mda && smtp_open(ctl) != -1)
1001 return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses));
1004 * Awkward case. User didn't specify an MDA. Our attempt to get a
1005 * listener socket failed. Try to cope anyway -- initial configuration
1006 * may have found procmail.
1010 report(stderr, GT_("%cMTP connect to %s failed\n"),
1012 ctl->smtphost ? ctl->smtphost : "localhost");
1014 #ifndef FALLBACK_MDA
1015 /* No fallback MDA declared. Bail out. */
1019 * If user had things set up to forward offsite, no way
1020 * we want to deliver locally!
1022 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
1026 * User was delivering locally. We have a fallback MDA.
1027 * Latch it in place, logging the error, and fall through.
1029 ctl->mda = FALLBACK_MDA;
1031 report(stderr, GT_("can't raise the listener; falling back to %s"),
1036 if (ctl->mda) /* must deliver through an MDA */
1037 return(open_mda_sink(ctl, msg, good_addresses, bad_addresses));
1042 void release_sink(struct query *ctl)
1043 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1045 if (ctl->bsmtp && sinkfp)
1052 sinkfp = (FILE *)NULL;
1054 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1058 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1059 /* perform end-of-message actions on the current output sink */
1065 /* close the delivery pipe, we'll reopen before next message */
1068 rc = pclose(sinkfp);
1069 sinkfp = (FILE *)NULL;
1074 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1079 GT_("MDA returned nonzero status %d\n"), rc);
1083 else if (ctl->bsmtp && sinkfp)
1087 /* implicit disk-full check here... */
1088 fputs(".\r\n", sinkfp);
1089 error = ferror(sinkfp);
1090 if (strcmp(ctl->bsmtp, "-"))
1091 if (fclose(sinkfp) == EOF) error = 1;
1095 GT_("Message termination or close of BSMTP file failed\n"));
1101 /* write message terminator */
1102 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1104 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1106 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1111 report(stderr, GT_("SMTP listener refused delivery\n"));
1112 SMTP_rset(ctl->smtp_socket); /* stay on the safe side */
1118 * If this is an SMTP connection, SMTP_eom() ate the response.
1119 * But could be this is an LMTP connection, in which case we have to
1120 * interpret either (a) a single 503 response meaning there
1121 * were no successful RCPT TOs, or (b) a variable number of
1122 * responses, one for each successful RCPT TO. We need to send
1123 * bouncemail on each failed response and then return TRUE anyway,
1124 * otherwise the message will get left in the queue and resent
1125 * to people who got it the first time.
1127 if (ctl->listener == LMTP_MODE)
1129 if (lmtp_responses == 0)
1131 SMTP_ok(ctl->smtp_socket);
1134 * According to RFC2033, 503 is the only legal response
1135 * if no RCPT TO commands succeeded. No error recovery
1136 * is really possible here, as we have no idea what
1137 * insane thing the listener might be doing if it doesn't
1140 if (atoi(smtp_response) == 503)
1141 report(stderr, GT_("LMTP delivery error on EOM\n"));
1144 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1148 * It's not completely clear what to do here. We choose to
1149 * interpret delivery failure here as a transient error,
1150 * the same way SMTP delivery failure is handled. If we're
1151 * wrong, an undead message will get stuck in the queue.
1160 /* eat the RFC2033-required responses, saving errors */
1161 xalloca(responses, char **, sizeof(char *) * lmtp_responses);
1162 for (errors = i = 0; i < lmtp_responses; i++)
1164 if (SMTP_ok(ctl->smtp_socket) == SM_OK)
1165 responses[i] = (char *)NULL;
1168 xalloca(responses[errors],
1170 strlen(smtp_response)+1);
1171 strcpy(responses[errors], smtp_response);
1177 return(TRUE); /* all deliveries succeeded */
1180 * One or more deliveries failed.
1181 * If we can bounce a failures list back to the
1182 * sender, and the postmaster does not want to
1183 * deal with the bounces return TRUE, deleting the
1184 * message from the server so it won't be
1185 * re-forwarded on subsequent poll cycles.
1187 return(send_bouncemail(ctl, msg, XMIT_ACCEPT,
1188 "LSMTP partial delivery failure.\r\n",
1189 errors, responses));
1197 int open_warning_by_mail(struct query *ctl, struct msgblk *msg)
1198 /* set up output sink for a mailed warning to calling user */
1203 * Dispatching warning email is a little complicated. The problem is
1204 * that we have to deal with three distinct cases:
1206 * 1. Single-drop running from user account. Warning mail should
1207 * go to the local name for which we're collecting (coincides
1208 * with calling user).
1210 * 2. Single-drop running from root or other privileged ID, with rc
1211 * file generated on the fly (Ken Estes's weird setup...) Mail
1212 * should go to the local name for which we're collecting (does not
1213 * coincide with calling user).
1215 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1216 * member null so this message will fall through to run.postmaster.
1218 * The zero in the reallen element means we won't pass a SIZE
1219 * option to ESMTP; the message length would be more trouble than
1220 * it's worth to compute.
1222 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0};
1225 strcat(reply.return_path, fetchmailhost);
1227 if (!MULTIDROP(ctl)) /* send to calling user */
1229 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1230 status = open_sink(ctl, &reply, &good, &bad);
1231 free_str_list(&reply.recipients);
1233 else /* send to postmaster */
1234 status = open_sink(ctl, &reply, &good, &bad);
1235 stuff_warning(ctl, "Date: %s", rfc822timestamp());
1239 #if defined(HAVE_STDARG_H)
1240 void stuff_warning(struct query *ctl, const char *fmt, ... )
1242 void stuff_warning(struct query *ctl, fmt, va_alist)
1244 const char *fmt; /* printf-style format */
1247 /* format and ship a warning message line by mail */
1249 char buf[POPBUFSIZE];
1253 * stuffline() requires its input to be writeable (for CR stripping),
1254 * so we needed to copy the message to a writeable buffer anyway in
1255 * case it was a string constant. We make a virtue of that necessity
1256 * here by supporting stdargs/varargs.
1258 #if defined(HAVE_STDARG_H)
1263 #ifdef HAVE_VSNPRINTF
1264 vsnprintf(buf, sizeof(buf), fmt, ap);
1266 vsprintf(buf, fmt, ap);
1270 #ifdef HAVE_SNPRINTF
1271 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1273 strcat(buf, "\r\n");
1274 #endif /* HAVE_SNPRINTF */
1276 stuffline(ctl, buf);
1279 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1280 /* sign and send mailed warnings */
1282 stuff_warning(ctl, GT_("--\r\n\t\t\t\tThe Fetchmail Daemon\r\n"));
1283 close_sink(ctl, msg, TRUE);
1286 /* sink.c ends here */