2 * sink.c -- forwarding/delivery support for fetchmail
4 * The interface of this module (open_sink(), stuff_line(), close_sink(),
5 * release_sink()) seals off the delivery logic from the protocol machine,
6 * so the latter won't have to care whether it's shipping to an [SL]MTP
7 * listener daemon or an MDA pipe.
9 * Copyright 1998 by Eric S. Raymond
10 * For license terms, see the file COPYING in this directory.
20 #endif /* HAVE_MEMORY_H */
23 #if defined(HAVE_STDARG_H)
31 #include "fetchmail.h"
33 /* for W* macros after pclose() */
35 #include <sys/types.h>
36 #include <sys/resource.h>
43 /* BSD portability hack...I know, this is an ugly place to put it */
44 #if !defined(SIGCHLD) && defined(SIGCLD)
45 #define SIGCHLD SIGCLD
48 /* makes the open_sink()/close_sink() pair non-reentrant */
49 static int lmtp_responses;
51 void smtp_close(struct query *ctl, int sayquit)
52 /* close the socket to SMTP server */
54 if (ctl->smtp_socket != -1)
57 SMTP_quit(ctl->smtp_socket, ctl->smtphostmode);
58 SockClose(ctl->smtp_socket);
59 ctl->smtp_socket = -1;
64 static void smtp_rset(struct query *ctl)
65 /* reset the mail transaction */
67 if (SMTP_rset(ctl->smtp_socket, ctl->smtphostmode) == SM_UNRECOVERABLE)
69 /* close the bad connection. fetchmail will reconnect for the
75 int smtp_setup(struct query *ctl)
76 /* try to open a socket to the appropriate SMTP server for this query */
78 /* maybe it's time to close the socket in order to force delivery */
79 if (last_smtp_ok > 0 && time((time_t *)NULL) - last_smtp_ok > mytimeout)
84 if (NUM_NONZERO(ctl->batchlimit)) {
85 if (batchcount == ctl->batchlimit)
90 /* if no socket to any SMTP host is already set up, try to open one */
91 if (ctl->smtp_socket == -1)
94 * RFC 1123 requires that the domain name in HELO address is a
95 * "valid principal domain name" for the client host. If we're
96 * running in invisible mode, violate this with malice
97 * aforethought in order to make the Received headers and
100 * In fact this code relies on the RFC1123 requirement that the
101 * SMTP listener must accept messages even if verification of the
102 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
104 * How we compute the true mailhost name to pass to the
105 * listener doesn't affect behavior on RFC1123-violating
106 * listeners that check for name match; we're going to lose
107 * on those anyway because we can never give them a name
108 * that matches the local machine fetchmail is running on.
109 * What it will affect is the listener's logging.
112 const char *id_me = run.invisible ? ctl->server.truename : fetchmailhost;
114 char *parsed_host = NULL;
119 * Run down the SMTP hunt list looking for a server that's up.
120 * Use both explicit hunt entries (value TRUE) and implicit
121 * (default) ones (value FALSE).
124 phase = LISTENER_WAIT;
126 set_timeout(ctl->server.timeout);
127 for (idp = ctl->smtphunt; idp; idp = idp->next)
130 const char *portnum = SMTP_PORT;
132 ctl->smtphost = idp->id; /* remember last host tried. */
133 if (ctl->smtphost[0]=='/')
135 ctl->smtphostmode = LMTP_MODE;
137 if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1)
142 ctl->smtphostmode = ctl->listener;
143 parsed_host = xstrdup(idp->id);
144 if ((cp = strrchr(parsed_host, '/')))
150 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,
151 ctl->server.plugout, &ai1)) == -1)
158 /* return immediately for ODMR */
159 if (ctl->server.protocol == P_ODMR)
164 return(ctl->smtp_socket); /* success */
167 /* first, probe for ESMTP */
168 if (SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_STARTSMTP) == SM_OK &&
169 SMTP_ehlo(ctl->smtp_socket, ctl->smtphostmode, id_me,
170 ctl->server.esmtp_name, ctl->server.esmtp_password,
171 &ctl->server.esmtp_options) == SM_OK)
175 * RFC 1869 warns that some listeners hang up on a failed EHLO,
176 * so it's safest not to assume the socket will still be good.
180 /* if opening for ESMTP failed, try SMTP */
181 if (ctl->smtphost[0]=='/')
183 if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1)
188 if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,
189 ctl->server.plugout, &ai1)) == -1)
196 if (SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_STARTSMTP) == SM_OK &&
197 SMTP_helo(ctl->smtp_socket, ctl->smtphostmode, id_me) == SM_OK)
206 * RFC 1123 requires that the domain name part of the
207 * RCPT TO address be "canonicalized", that is a FQDN
208 * or MX but not a CNAME. Some listeners (like exim)
209 * enforce this. Now that we have the actual hostname,
210 * compute what we should canonicalize with.
212 xfree(ctl->destaddr);
213 if (ctl->smtpaddress)
214 ctl->destaddr = xstrdup(ctl->smtpaddress);
215 /* parsed_host is smtphost without the /port */
216 else if (parsed_host && parsed_host[0] != 0)
217 ctl->destaddr = xstrdup(parsed_host);
218 /* No smtphost is specified or it is a UNIX socket, then use
219 localhost as a domain part. */
221 ctl->destaddr = xstrdup("localhost");
224 /* end if (ctl->smtp_socket == -1) */
226 if (outlevel >= O_DEBUG && ctl->smtp_socket != -1)
227 report(stdout, GT_("forwarding to %s\n"), ctl->smtphost);
229 return(ctl->smtp_socket);
232 static void sanitize(char *s)
237 for (cp = s; (cp = strchr (cp, '\'')); cp++)
241 char *rcpt_address(struct query *ctl, const char *id,
244 static char addr[HOSTLEN+USERNAMELEN+1];
247 snprintf(addr, sizeof (addr), "%s", id);
249 else if (usesmtpname && ctl->smtpname)
251 snprintf(addr, sizeof (addr), "%s", ctl->smtpname);
255 snprintf(addr, sizeof (addr), "%s@%s", id, ctl->destaddr);
260 static int send_bouncemail(struct query *ctl, struct msgblk *msg,
261 int userclass, const char *message /* should have \r\n at the end */,
262 int nerrors, char *errors[])
263 /* bounce back an error report a la RFC 1892 */
265 char daemon_name[15 + HOSTLEN] = "MAILER-DAEMON@";
266 char boundary[BUFSIZ];
267 const char *bounce_to;
269 static char *fqdn_of_host = NULL;
270 const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@";
272 /* don't bounce in reply to undeliverable bounces */
273 if (!msg || !msg->return_path[0] ||
274 strcmp(msg->return_path, "<>") == 0 ||
275 strcasecmp(msg->return_path, md1) == 0 ||
276 strncasecmp(msg->return_path, md2, strlen(md2)) == 0)
279 bounce_to = (run.bouncemail ? msg->return_path : run.postmaster);
281 /* can't just use fetchmailhost here, it might be localhost */
282 if (fqdn_of_host == NULL)
283 fqdn_of_host = host_fqdn(0); /* can't afford to bail out and
285 strlcat(daemon_name, fqdn_of_host, sizeof(daemon_name));
287 /* we need only SMTP for this purpose */
288 /* XXX FIXME: hardcoding localhost is nonsense if smtphost can be
290 if ((sock = SockOpen("localhost", SMTP_PORT, NULL, &ai1)) == -1)
293 if (SMTP_ok(sock, SMTP_MODE, TIMEOUT_STARTSMTP) != SM_OK)
299 if (SMTP_helo(sock, SMTP_MODE, fetchmailhost) != SM_OK
300 || SMTP_from(sock, SMTP_MODE, "<>", (char *)NULL) != SM_OK
301 || SMTP_rcpt(sock, SMTP_MODE, bounce_to) != SM_OK
302 || SMTP_data(sock, SMTP_MODE) != SM_OK)
304 SMTP_quit(sock, SMTP_MODE);
309 /* our first duty is to keep the sacred foo counters turning... */
310 snprintf(boundary, sizeof(boundary), "foo-mani-padme-hum-%ld-%ld-%ld",
311 (long)getpid(), (long)getppid(), (long)time(NULL));
313 if (outlevel >= O_VERBOSE)
314 report(stdout, GT_("SMTP: (bounce-message body)\n"));
316 /* this will usually go to sylog... */
317 report(stderr, GT_("mail from %s bounced to %s\n"),
318 daemon_name, bounce_to);
321 /* bouncemail headers */
322 SockPrintf(sock, "Subject: Mail delivery failed: returning message to sender\r\n");
323 SockPrintf(sock, "From: Mail Delivery System <%s>\r\n", daemon_name);
324 SockPrintf(sock, "To: %s\r\n", bounce_to);
325 SockPrintf(sock, "MIME-Version: 1.0\r\n");
326 SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary);
327 SockPrintf(sock, "\r\n");
329 /* RFC1892 part 1 -- human-readable message */
330 SockPrintf(sock, "--%s\r\n", boundary);
331 SockPrintf(sock,"Content-Type: text/plain\r\n");
332 SockPrintf(sock, "\r\n");
333 SockPrintf(sock, "This message was created automatically by mail delivery software.\r\n");
334 SockPrintf(sock, "\r\n");
335 SockPrintf(sock, "A message that you sent could not be delivered to one or more of its\r\n");
336 SockPrintf(sock, "recipients. This is a permanent error.\r\n");
337 SockPrintf(sock, "\r\n");
338 SockPrintf(sock, "Reason: %s", message);
339 SockPrintf(sock, "\r\n");
340 SockPrintf(sock, "The following address(es) failed:\r\n");
348 for (idp = msg->recipients; idp; idp = idp->next)
350 if (idp->val.status.mark == userclass)
353 SockPrintf(sock, "%s\r\n", rcpt_address (ctl, idp->id, 1));
355 if (nerrors == 1) error = errors[0];
356 else if (nerrors <= nusers)
358 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
361 else error = errors[nusers++];
363 SockPrintf(sock, " SMTP error: %s\r\n\r\n", error);
367 /* RFC1892 part 2 -- machine-readable responses */
368 SockPrintf(sock, "--%s\r\n", boundary);
369 SockPrintf(sock,"Content-Type: message/delivery-status\r\n");
370 SockPrintf(sock, "\r\n");
371 SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fqdn_of_host);
374 for (idp = msg->recipients; idp; idp = idp->next)
375 if (idp->val.status.mark == userclass)
378 /* Minimum RFC1894 compliance + Diagnostic-Code field */
379 SockPrintf(sock, "\r\n");
380 SockPrintf(sock, "Final-Recipient: rfc822; %s\r\n",
381 rcpt_address (ctl, idp->id, 1));
382 SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp());
383 SockPrintf(sock, "Action: failed\r\n");
386 /* one error applies to all users */
388 else if (nerrors <= nusers)
390 SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n");
394 /* errors correspond 1-1 to selected users */
395 error = errors[nusers++];
397 if (strlen(error) > 9 && isdigit((unsigned char)error[4])
398 && error[5] == '.' && isdigit((unsigned char)error[6])
399 && error[7] == '.' && isdigit((unsigned char)error[8]))
400 /* Enhanced status code available, use it */
401 SockPrintf(sock, "Status: %5.5s\r\n", &(error[4]));
403 /* Enhanced status code not available, fake one */
404 SockPrintf(sock, "Status: %c.0.0\r\n", error[0]);
405 SockPrintf(sock, "Diagnostic-Code: %s\r\n", error);
407 SockPrintf(sock, "\r\n");
410 /* RFC1892 part 3 -- headers of undelivered message */
411 SockPrintf(sock, "--%s\r\n", boundary);
412 SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n");
413 SockPrintf(sock, "\r\n");
416 SockWrite(sock, msg->headers, strlen(msg->headers));
417 SockPrintf(sock, "\r\n");
419 SockPrintf(sock, "--%s--\r\n", boundary);
421 if (SMTP_eom(sock, SMTP_MODE) != SM_OK
422 || SMTP_quit(sock, SMTP_MODE) != SM_OK)
433 static int handle_smtp_report(struct query *ctl, struct msgblk *msg)
434 /* handle SMTP errors based on the content of SMTP_response */
435 /* returns either PS_REFUSED (to delete message from the server),
436 * or PS_TRANSIENT (keeps the message on the server) */
438 int smtperr = atoi(smtp_response);
441 responses[0] = xstrdup(smtp_response);
445 * Don't do this! It can really mess you up if, for example, you're
446 * reporting an error with a single RCPT TO address among several;
447 * RSET discards the message body and it doesn't get sent to the
450 smtp_rset(ctl); /* stay on the safe side */
451 if (outlevel >= O_DEBUG)
452 report(stdout, GT_("Saved error is still %d\n"), smtperr);
453 #endif /* __UNUSED */
456 * Note: send_bouncemail message strings are not made subject
457 * to gettext translation because (a) they're going to be
458 * embedded in a text/plain 7bit part, and (b) they're
459 * going to be associated with listener error-response
460 * messages, which are probably in English (none of the
461 * MTAs I know about are internationalized).
463 if (str_find(&ctl->antispam, smtperr))
466 * SMTP listener explicitly refuses to deliver mail
467 * coming from this address, probably due to an
468 * anti-spam domain exclusion. Respect this. Don't
469 * try to ship the message, and don't prevent it from
470 * being deleted. There's no point in bouncing the
471 * email either since most spammers don't put their
472 * real return email address anywhere in the headers
473 * (unless the user insists with the SET SPAMBOUNCE
478 * 571 = sendmail's "unsolicited email refused"
479 * 550 = exim's new antispam response (temporary)
480 * 501 = exim's old antispam response
481 * 554 = Postfix antispam response.
487 snprintf(rejmsg, sizeof(rejmsg),
488 "spam filter or virus scanner rejected message because:\r\n"
489 "%s\r\n", responses[0]);
491 send_bouncemail(ctl, msg, XMIT_ACCEPT,
492 rejmsg, 1, responses);
499 * Suppress error message only if the response specifically
500 * meant `excluded for policy reasons'. We *should* see
501 * an error when the return code is less specific.
504 report(stderr, GT_("%cMTP error: %s\n"),
510 case 552: /* message exceeds fixed maximum message size */
512 * Permanent no-go condition on the
513 * ESMTP server. Don't try to ship the message,
514 * and allow it to be deleted.
517 send_bouncemail(ctl, msg, XMIT_ACCEPT,
518 "This message was too large (SMTP error 552).\r\n",
523 case 553: /* invalid sending domain */
525 * These latter days 553 usually means a spammer is trying to
526 * cover his tracks. We never bouncemail on these, because
527 * (a) the return address is invalid by definition, and
528 * (b) we wouldn't want spammers to get confirmation that
529 * this address is live, anyway.
531 #ifdef __DONT_FEED_THE_SPAMMERS__
533 send_bouncemail(ctl, msg, XMIT_ACCEPT,
534 "Invalid address in MAIL FROM (SMTP error 553).\r\n",
536 #endif /* __DONT_FEED_THE_SPAMMERS__ */
540 case 530: /* must issue STARTTLS error */
542 * Some SMTP servers insist on encrypted communication
543 * Let's set PS_TRANSIENT, otherwise all messages to be sent
544 * over such server would be blackholed - see RFC 3207.
546 if (outlevel > O_SILENT)
547 report_complete(stdout,
548 GT_("SMTP server requires STARTTLS, keeping message.\n"));
550 return(PS_TRANSIENT);
553 /* bounce non-transient errors back to the sender */
554 if (smtperr >= 500 && smtperr <= 599)
557 send_bouncemail(ctl, msg, XMIT_ACCEPT,
558 "General SMTP/ESMTP error.\r\n",
564 * We're going to end up here on 4xx errors, like:
566 * 451: temporarily unable to identify sender (exim)
567 * 452: temporary out-of-queue-space condition on the ESMTP server.
569 * These are temporary errors. Don't try to ship the message,
570 * and suppress deletion so it can be retried on a future
573 * Bouncemail *might* be appropriate here as a delay
574 * notification (note; if we ever add this, we must make
575 * sure the RFC1894 Action field is "delayed" rather than
576 * "failed"). But it's not really necessary because
577 * these are not actual failures, we're very likely to be
578 * able to recover on the next cycle.
581 return(PS_TRANSIENT);
585 static int handle_smtp_report_without_bounce(struct query *ctl, struct msgblk *msg)
586 /* handle SMTP errors based on the content of SMTP_response */
587 /* atleast one PS_TRANSIENT: do not send the bounce mail, keep the mail;
588 * no PS_TRANSIENT, atleast one PS_SUCCESS: send the bounce mail, delete the mail;
589 * no PS_TRANSIENT, no PS_SUCCESS: do not send the bounce mail, delete the mail */
591 int smtperr = atoi(smtp_response);
595 if (str_find(&ctl->antispam, smtperr))
603 report(stderr, GT_("%cMTP error: %s\n"),
609 case 552: /* message exceeds fixed maximum message size */
614 case 553: /* invalid sending domain */
615 #ifdef __DONT_FEED_THE_SPAMMERS__
618 #endif /* __DONT_FEED_THE_SPAMMERS__ */
622 /* bounce non-transient errors back to the sender */
623 if (smtperr >= 500 && smtperr <= 599)
625 return(PS_TRANSIENT);
629 /* these are shared by open_sink and stuffline */
632 int stuffline(struct query *ctl, char *buf)
633 /* ship a line to the given control block's output sink (SMTP server or MDA) */
641 /* The line may contain NUL characters. Find the last char to use
642 * -- the real line termination is the sequence "\n\0".
644 last = buf + 1; /* last[-1] must be valid! */
645 while ((last += strlen(last)) && (last[-1] != '\n'))
648 /* fix message lines that have only \n termination (for qmail) */
651 if (last - 1 == buf || last[-2] != '\r')
660 phase = FORWARDING_WAIT;
663 * SMTP byte-stuffing. We only do this if the protocol does *not*
664 * use .<CR><LF> as EOM. If it does, the server will already have
665 * decorated any . lines it sends back up.
669 if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */
672 /* writing to MDA, undo byte-stuffing */
675 /* writing to SMTP, leave the byte-stuffing in place */;
678 else /* if (!protocol->delimited) -- not byte-stuffed already */
683 n = SockWrite(ctl->smtp_socket, buf, 1);
685 n = fwrite(buf, 1, 1, sinkfp);
686 if (ferror(sinkfp)) n = -1;
694 /* we may need to strip carriage returns */
699 for (sp = tp = buf; sp < last; sp++)
707 if (ctl->mda || ctl->bsmtp) {
708 n = fwrite(buf, 1, last - buf, sinkfp);
709 if (ferror(sinkfp)) n = -1;
710 } else if (ctl->smtp_socket != -1)
711 n = SockWrite(ctl->smtp_socket, buf, last - buf);
718 static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg,
719 int *good_addresses, int *bad_addresses)
720 /* open a BSMTP stream */
725 if (strcmp(ctl->bsmtp, "-") == 0)
728 sinkfp = fopen(ctl->bsmtp, "a");
730 if (!sinkfp || ferror(sinkfp)) {
731 report(stderr, GT_("BSMTP file open failed: %s\n"),
736 /* see the ap computation under the SMTP branch */
737 need_anglebrs = (msg->return_path[0] != '<');
740 need_anglebrs ? "<" : "",
741 (msg->return_path[0]) ? msg->return_path : user,
742 need_anglebrs ? ">" : "");
744 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
745 fputs(" BODY=8BITMIME", sinkfp);
746 else if (ctl->mimemsg & MSG_IS_7BIT)
747 fputs(" BODY=7BIT", sinkfp);
749 /* exim's BSMTP processor does not handle SIZE */
750 /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */
752 fprintf(sinkfp, "\r\n");
755 * RFC 1123 requires that the domain name part of the
756 * RCPT TO address be "canonicalized", that is a FQDN
757 * or MX but not a CNAME. Some listeners (like exim)
758 * enforce this. Now that we have the actual hostname,
759 * compute what we should canonicalize with.
761 xfree(ctl->destaddr);
762 ctl->destaddr = xstrdup(ctl->smtpaddress ? ctl->smtpaddress : "localhost");
765 for (idp = msg->recipients; idp; idp = idp->next)
766 if (idp->val.status.mark == XMIT_ACCEPT)
768 fprintf(sinkfp, "RCPT TO:<%s>\r\n",
769 rcpt_address (ctl, idp->id, 1));
773 fputs("DATA\r\n", sinkfp);
775 if (fflush(sinkfp) || ferror(sinkfp))
777 report(stderr, GT_("BSMTP preamble write failed: %s.\n"), strerror(errno));
784 /* this is experimental and will be removed if double bounces are reported */
785 #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS
788 static const char *is_quad(const char *q)
789 /* Check if the string passed in points to what could be one quad of a
790 * dotted-quad IP address. Requirements are that the string is not a
791 * NULL pointer, begins with a period (which is skipped) or a digit
792 * and ends with a period or a NULL. If these requirements are met, a
793 * pointer to the last character (the period or the NULL character) is
794 * returned; otherwise NULL.
803 for(r=q;isdigit((unsigned char)*r);r++)
805 if ( ((*r) && (*r != '.')) || ((r-q) < 1) || ((r-q)>3) )
807 /* Make sure quad is < 255 */
816 else if (*(q+1) == '5')
826 static int is_dottedquad(const char *hostname)
827 /* Returns a true value if the passed in string looks like an IP
828 * address in dotted-quad form, and a false value otherwise.
832 return ((hostname=is_quad(is_quad(is_quad(is_quad(hostname))))) != NULL) &&
836 static int open_smtp_sink(struct query *ctl, struct msgblk *msg,
837 int *good_addresses, int *bad_addresses /* this must be signed, to prevent endless loop in from_addresses */)
838 /* open an SMTP stream */
842 char options[MSGBUFSIZE];
843 char addr[HOSTLEN+USERNAMELEN+1];
844 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
845 char **from_responses;
846 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
848 int force_transient_error = 0;
852 * Compute ESMTP options.
855 if (ctl->server.esmtp_options & ESMTP_8BITMIME) {
856 if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT))
857 strcpy(options, " BODY=8BITMIME");
858 else if (ctl->mimemsg & MSG_IS_7BIT)
859 strcpy(options, " BODY=7BIT");
862 if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0)
863 sprintf(options + strlen(options), " SIZE=%d", msg->reallen);
866 * Try to get the SMTP listener to take the Return-Path
867 * address as MAIL FROM. If it won't, fall back on the
868 * remotename and mailserver host. This won't affect replies,
869 * which use the header From address anyway; the MAIL FROM
870 * address is a place for the SMTP listener to send
871 * bouncemail. The point is to guarantee a FQDN in the MAIL
872 * FROM line -- some SMTP listeners, like smail, become
875 * RFC 1123 requires that the domain name part of the
876 * MAIL FROM address be "canonicalized", that is a
877 * FQDN or MX but not a CNAME. We'll assume the Return-Path
878 * header is already in this form here (it certainly
879 * is if rewrite is on). RFC 1123 is silent on whether
880 * a nonexistent hostname part is considered canonical.
882 * This is a potential problem if the MTAs further upstream
883 * didn't pass canonicalized From/Return-Path lines, *and* the
884 * local SMTP listener insists on them.
886 * Handle the case where an upstream MTA is setting a return
887 * path equal to "@". Ghod knows why anyone does this, but
888 * it's been reported to happen in mail from Amazon.com and
891 * Also, if the hostname is a dotted quad, wrap it in square brackets.
892 * Apparently this is required by RFC2821, section 4.1.3.
894 if (!msg->return_path[0] || (msg->return_path[0] == '@'))
896 if (strchr(ctl->remotename,'@') || strchr(ctl->remotename,'!'))
898 snprintf(addr, sizeof(addr), "%s", ctl->remotename);
900 else if (is_dottedquad(ctl->server.truename))
902 snprintf(addr, sizeof(addr), "%s@[%s]", ctl->remotename,
903 ctl->server.truename);
907 snprintf(addr, sizeof(addr),
908 "%s@%s", ctl->remotename, ctl->server.truename);
912 else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
913 ap = msg->return_path;
914 /* in case Return-Path was "<>" we want to preserve that */
915 else if (strcmp(msg->return_path,"<>") == 0)
916 ap = msg->return_path;
917 else /* in case Return-Path existed but was local */
919 if (is_dottedquad(ctl->server.truename))
921 snprintf(addr, sizeof(addr), "%s@[%s]", msg->return_path,
922 ctl->server.truename);
926 snprintf(addr, sizeof(addr), "%s@%s",
927 msg->return_path, ctl->server.truename);
932 if ((smtp_err = SMTP_from(ctl->smtp_socket, ctl->smtphostmode,
933 ap, options)) == SM_UNRECOVERABLE)
936 return(PS_TRANSIENT);
938 if (smtp_err != SM_OK)
940 int err = handle_smtp_report(ctl, msg); /* map to PS_TRANSIENT or PS_REFUSED */
942 smtp_rset(ctl); /* stay on the safe side */
947 * Now list the recipient addressees
950 for (idp = msg->recipients; idp; idp = idp->next)
952 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
953 from_responses = (char **)xmalloc(sizeof(char *) * total_addresses);
954 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
955 for (idp = msg->recipients; idp; idp = idp->next)
956 if (idp->val.status.mark == XMIT_ACCEPT)
959 address = rcpt_address (ctl, idp->id, 1);
960 if ((smtp_err = SMTP_rcpt(ctl->smtp_socket, ctl->smtphostmode,
961 address)) == SM_UNRECOVERABLE)
965 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
966 while (*bad_addresses)
967 free(from_responses[--*bad_addresses]);
968 free(from_responses);
969 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
970 return(PS_TRANSIENT);
972 if (smtp_err == SM_OK)
976 switch (handle_smtp_report_without_bounce(ctl, msg))
979 force_transient_error = 1;
983 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
984 from_responses[*bad_addresses] = xstrdup(smtp_response);
985 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
988 idp->val.status.mark = XMIT_RCPTBAD;
989 if (outlevel >= O_VERBOSE)
991 GT_("%cMTP listener doesn't like recipient address `%s'\n"),
992 ctl->smtphostmode, address);
996 if (outlevel >= O_VERBOSE)
998 GT_("%cMTP listener doesn't really like recipient address `%s'\n"),
999 ctl->smtphostmode, address);
1005 if (force_transient_error) {
1006 /* do not risk dataloss due to overengineered multidrop
1007 * crap. If one of the recipients returned PS_TRANSIENT,
1008 * we return exactly that.
1010 smtp_rset(ctl); /* required by RFC1870 */
1013 #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS
1015 * This should not be necessary, because the SMTP listener itself
1016 * should generate a bounce for the bad address.
1018 * XXX FIXME 2006-01-19: is this comment true? I don't think
1019 * it is, because the SMTP listener isn't required to accept bogus
1020 * messages. There appears to be general SMTP<->MDA and
1021 * responsibility confusion.
1024 send_bouncemail(ctl, msg, XMIT_RCPTBAD,
1025 "Some addresses were rejected by the MDA fetchmail forwards to.\r\n",
1026 *bad_addresses, from_responses);
1027 while (*bad_addresses)
1028 free(from_responses[--*bad_addresses]);
1029 free(from_responses);
1030 #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */
1033 * It's tempting to do local notification only if bouncemail was
1034 * insufficient -- that is, to add && total_addresses > *bad_addresses
1035 * to the test here. The problem with this theory is that it would
1036 * make initial diagnosis of a broken multidrop configuration very
1037 * hard -- most single-recipient messages would just invisibly bounce.
1039 if (!(*good_addresses))
1041 if (!run.postmaster[0])
1043 if (outlevel >= O_VERBOSE)
1044 report(stderr, GT_("no address matches; no postmaster set.\n"));
1045 smtp_rset(ctl); /* required by RFC1870 */
1048 if ((smtp_err = SMTP_rcpt(ctl->smtp_socket, ctl->smtphostmode,
1049 rcpt_address (ctl, run.postmaster, 0))) == SM_UNRECOVERABLE)
1052 return(PS_TRANSIENT);
1054 if (smtp_err != SM_OK)
1056 report(stderr, GT_("can't even send to %s!\n"), run.postmaster);
1057 smtp_rset(ctl); /* required by RFC1870 */
1061 if (outlevel >= O_VERBOSE)
1062 report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster);
1066 * Tell the listener we're ready to send data.
1067 * Some listeners (like zmailer) may return antispam errors here.
1069 if ((smtp_err = SMTP_data(ctl->smtp_socket, ctl->smtphostmode))
1070 == SM_UNRECOVERABLE)
1073 return(PS_TRANSIENT);
1075 if (smtp_err != SM_OK)
1077 int err = handle_smtp_report(ctl, msg);
1078 smtp_rset(ctl); /* stay on the safe side */
1083 * We need to stash this away in order to know how many
1084 * response lines to expect after the LMTP end-of-message.
1086 lmtp_responses = *good_addresses;
1091 static int open_mda_sink(struct query *ctl, struct msgblk *msg,
1092 int *good_addresses, int *bad_addresses)
1093 /* open a stream to a local MDA */
1097 #endif /* HAVE_SETEUID */
1099 int length = 0, fromlen = 0, nameslen = 0;
1100 char *names = NULL, *before, *after, *from = NULL;
1102 (void)bad_addresses;
1103 xfree(ctl->destaddr);
1104 ctl->destaddr = xstrdup("localhost");
1106 for (idp = msg->recipients; idp; idp = idp->next)
1107 if (idp->val.status.mark == XMIT_ACCEPT)
1108 (*good_addresses)++;
1110 length = strlen(ctl->mda);
1111 before = xstrdup(ctl->mda);
1113 /* get user addresses for %T (or %s for backward compatibility) */
1114 if (strstr(before, "%s") || strstr(before, "%T"))
1117 * We go through this in order to be able to handle very
1118 * long lists of users and (re)implement %s.
1121 for (idp = msg->recipients; idp; idp = idp->next)
1122 if ((idp->val.status.mark == XMIT_ACCEPT))
1123 nameslen += (strlen(idp->id) + 1); /* string + ' ' */
1124 if ((*good_addresses == 0))
1125 nameslen = strlen(run.postmaster);
1127 names = (char *)xmalloc(nameslen + 1); /* account for '\0' */
1128 if (*good_addresses == 0)
1129 strcpy(names, run.postmaster);
1133 for (idp = msg->recipients; idp; idp = idp->next)
1134 if (idp->val.status.mark == XMIT_ACCEPT)
1136 strcat(names, idp->id);
1139 names[--nameslen] = '\0'; /* chop trailing space */
1145 /* get From address for %F */
1146 if (strstr(before, "%F"))
1148 from = xstrdup(msg->return_path);
1152 fromlen = strlen(from);
1155 /* do we have to build an mda string? */
1160 /* find length of resulting mda string */
1162 while ((sp = strstr(sp, "%s"))) {
1163 length += nameslen; /* subtract %s and add '' */
1167 while ((sp = strstr(sp, "%T"))) {
1168 length += nameslen; /* subtract %T and add '' */
1172 while ((sp = strstr(sp, "%F"))) {
1173 length += fromlen; /* subtract %F and add '' */
1177 after = (char *)xmalloc(length + 1);
1179 /* copy mda source string to after, while expanding %[sTF] */
1180 for (dp = after, sp = before; (*dp = *sp); dp++, sp++) {
1181 if (sp[0] != '%') continue;
1183 /* need to expand? BTW, no here overflow, because in
1184 ** the worst case (end of string) sp[1] == '\0' */
1185 if (sp[1] == 's' || sp[1] == 'T') {
1190 sp++; /* position sp over [sT] */
1191 dp--; /* adjust dp */
1192 } else if (sp[1] == 'F') {
1197 sp++; /* position sp over F */
1198 dp--; /* adjust dp */
1217 if (outlevel >= O_DEBUG)
1218 report(stdout, GT_("about to deliver with: %s\n"), before);
1222 * Arrange to run with user's permissions if we're root.
1223 * This will initialize the ownership of any files the
1224 * MDA creates properly. (The seteuid call is available
1225 * under all BSDs and Linux)
1227 orig_uid = getuid();
1228 if (seteuid(ctl->uid)) {
1229 report(stderr, GT_("Cannot switch effective user id to %ld: %s\n"), (long)ctl->uid, strerror(errno));
1232 #endif /* HAVE_SETEUID */
1234 sinkfp = popen(before, "w");
1239 /* this will fail quietly if we didn't start as root */
1240 if (seteuid(orig_uid)) {
1241 report(stderr, GT_("Cannot switch effective user id back to original %ld: %s\n"), (long)orig_uid, strerror(errno));
1244 #endif /* HAVE_SETEUID */
1248 report(stderr, GT_("MDA open failed\n"));
1253 * We need to disable the normal SIGCHLD handling here because
1254 * sigchld_handler() would reap away the error status, returning
1255 * error status instead of 0 for successful completion.
1257 set_signal_handler(SIGCHLD, SIG_DFL);
1262 int open_sink(struct query *ctl, struct msgblk *msg,
1263 int *good_addresses, int *bad_addresses)
1264 /* set up sinkfp to be an input sink we can ship a message to */
1266 *bad_addresses = *good_addresses = 0;
1268 if (want_progress() && outlevel >= O_VERBOSE && !ctl->mda && !ctl->bsmtp) puts("");
1270 if (ctl->bsmtp) /* dump to a BSMTP batch file */
1271 return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses));
1273 * Try to forward to an SMTP or LMTP listener. If the attempt to
1274 * open a socket fails, fall through to attempt delivery via
1277 else if (!ctl->mda && smtp_setup(ctl) != -1)
1278 return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses));
1281 * Awkward case. User didn't specify an MDA. Our attempt to get a
1282 * listener socket failed. Try to cope anyway -- initial configuration
1283 * may have found procmail.
1287 report(stderr, GT_("%cMTP connect to %s failed\n"),
1289 ctl->smtphost ? ctl->smtphost : "localhost");
1291 #ifndef FALLBACK_MDA
1292 /* No fallback MDA declared. Bail out. */
1296 * If user had things set up to forward offsite, no way
1297 * we want to deliver locally!
1299 if (ctl->smtphost && strcmp(ctl->smtphost, "localhost"))
1303 * User was delivering locally. We have a fallback MDA.
1304 * Latch it in place, logging the error, and fall through.
1305 * Set stripcr as we would if MDA had been the initial transport
1307 ctl->mda = FALLBACK_MDA;
1309 ctl->stripcr = TRUE;
1311 report(stderr, GT_("can't raise the listener; falling back to %s"),
1316 if (ctl->mda) /* must deliver through an MDA */
1317 return(open_mda_sink(ctl, msg, good_addresses, bad_addresses));
1322 void release_sink(struct query *ctl)
1323 /* release the per-message output sink, whether it's a pipe or SMTP socket */
1325 if (ctl->bsmtp && sinkfp)
1327 if (strcmp(ctl->bsmtp, "-"))
1330 sinkfp = (FILE *)NULL;
1338 sinkfp = (FILE *)NULL;
1340 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1344 int close_sink(struct query *ctl, struct msgblk *msg, flag forward)
1345 /* perform end-of-message actions on the current output sink */
1349 if (want_progress() && outlevel >= O_VERBOSE && !ctl->mda && !ctl->bsmtp) puts("");
1351 if (ctl->bsmtp && sinkfp) {
1354 /* implicit disk-full check here... */
1355 fputs(".\r\n", sinkfp);
1356 error = ferror(sinkfp);
1358 if (strcmp(ctl->bsmtp, "-"))
1360 if (fclose(sinkfp) == EOF) {
1364 sinkfp = (FILE *)NULL;
1369 GT_("Message termination or close of BSMTP file failed: %s\n"), strerror(oerrno));
1372 } else if (ctl->mda) {
1373 int rc = 0, e = 0, e2 = 0, err = 0;
1375 /* close the delivery pipe, we'll reopen before next message */
1379 err = 1, e2 = errno;
1380 if ((fflush(sinkfp)))
1381 err = 1, e2 = errno;
1384 rc = pclose(sinkfp);
1386 sinkfp = (FILE *)NULL;
1389 deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */
1394 report(stderr, GT_("Error writing to MDA: %s\n"), strerror(e2));
1395 } else if (WIFSIGNALED(rc)) {
1397 GT_("MDA died of signal %d\n"), WTERMSIG(rc));
1398 } else if (WIFEXITED(rc)) {
1400 GT_("MDA returned nonzero status %d\n"), WEXITSTATUS(rc));
1403 GT_("Strange: MDA pclose returned %d and errno %d/%s, cannot handle at %s:%d\n"),
1404 rc, e, strerror(e), __FILE__, __LINE__);
1412 /* write message terminator */
1413 if ((smtp_err = SMTP_eom(ctl->smtp_socket, ctl->smtphostmode))
1414 == SM_UNRECOVERABLE)
1419 if (smtp_err != SM_OK)
1421 if (handle_smtp_report(ctl, msg) != PS_REFUSED)
1423 smtp_rset(ctl); /* stay on the safe side */
1428 report(stderr, GT_("SMTP listener refused delivery\n"));
1429 smtp_rset(ctl); /* stay on the safe side */
1435 * If this is an SMTP connection, SMTP_eom() ate the response.
1436 * But could be this is an LMTP connection, in which case we have to
1437 * interpret either (a) a single 503 response meaning there
1438 * were no successful RCPT TOs, or (b) a variable number of
1439 * responses, one for each successful RCPT TO. We need to send
1440 * bouncemail on each failed response and then return TRUE anyway,
1441 * otherwise the message will get left in the queue and resent
1442 * to people who got it the first time.
1444 if (ctl->smtphostmode == LMTP_MODE)
1446 if (lmtp_responses == 0)
1448 SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_EOM);
1451 * According to RFC2033, 503 is the only legal response
1452 * if no RCPT TO commands succeeded. No error recovery
1453 * is really possible here, as we have no idea what
1454 * insane thing the listener might be doing if it doesn't
1457 if (atoi(smtp_response) == 503)
1458 report(stderr, GT_("LMTP delivery error on EOM\n"));
1461 GT_("Unexpected non-503 response to LMTP EOM: %s\n"),
1465 * It's not completely clear what to do here. We choose to
1466 * interpret delivery failure here as a transient error,
1467 * the same way SMTP delivery failure is handled. If we're
1468 * wrong, an undead message will get stuck in the queue.
1474 int i, errors, rc = FALSE;
1477 /* eat the RFC2033-required responses, saving errors */
1478 responses = (char **)xmalloc(sizeof(char *) * lmtp_responses);
1479 for (errors = i = 0; i < lmtp_responses; i++)
1481 if ((smtp_err = SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_EOM))
1482 == SM_UNRECOVERABLE)
1487 if (smtp_err != SM_OK)
1489 responses[errors] = xstrdup(smtp_response);
1495 rc = TRUE; /* all deliveries succeeded */
1498 * One or more deliveries failed.
1499 * If we can bounce a failures list back to the
1500 * sender, and the postmaster does not want to
1501 * deal with the bounces return TRUE, deleting the
1502 * message from the server so it won't be
1503 * re-forwarded on subsequent poll cycles.
1505 rc = send_bouncemail(ctl, msg, XMIT_ACCEPT,
1506 "LMTP partial delivery failure.\r\n",
1510 for (i = 0; i < errors; i++)
1521 int open_warning_by_mail(struct query *ctl)
1522 /* set up output sink for a mailed warning to calling user */
1527 * Dispatching warning email is a little complicated. The problem is
1528 * that we have to deal with three distinct cases:
1530 * 1. Single-drop running from user account. Warning mail should
1531 * go to the local name for which we're collecting (coincides
1532 * with calling user).
1534 * 2. Single-drop running from root or other privileged ID, with rc
1535 * file generated on the fly (Ken Estes's weird setup...) Mail
1536 * should go to the local name for which we're collecting (does not
1537 * coincide with calling user).
1539 * 3. Multidrop. Mail must go to postmaster. We leave the recipients
1540 * member null so this message will fall through to run.postmaster.
1542 * The zero in the reallen element means we won't pass a SIZE
1543 * option to ESMTP; the message length would be more trouble than
1544 * it's worth to compute.
1546 struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0, 0};
1549 strlcat(reply.return_path, ctl->smtpaddress ? ctl->smtpaddress :
1550 fetchmailhost, sizeof(reply.return_path));
1552 if (!MULTIDROP(ctl)) /* send to calling user */
1554 save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT);
1555 status = open_sink(ctl, &reply, &good, &bad);
1556 free_str_list(&reply.recipients);
1558 else /* send to postmaster */
1559 status = open_sink(ctl, &reply, &good, &bad);
1561 stuff_warning(NULL, ctl, "From: FETCHMAIL-DAEMON@%s",
1562 ctl->smtpaddress ? ctl->smtpaddress : fetchmailhost);
1563 stuff_warning(NULL, ctl, "Date: %s", rfc822timestamp());
1564 stuff_warning(NULL, ctl, "MIME-Version: 1.0");
1565 stuff_warning(NULL, ctl, "Content-Transfer-Encoding: 8bit");
1566 stuff_warning(NULL, ctl, "Content-Type: text/plain; charset=\"%s\"", iana_charset);
1571 /* format and ship a warning message line by mail */
1572 /* if rfc2047charset is non-NULL, encode the line (that is assumed to be
1573 * a header line) as per RFC-2047 using rfc2047charset as the character
1575 #if defined(HAVE_STDARG_H)
1576 void stuff_warning(const char *rfc2047charset, struct query *ctl, const char *fmt, ... )
1578 void stuff_warning(rfc2047charset, ctl, fmt, va_alist)
1579 const char *charset;
1581 const char *fmt; /* printf-style format */
1585 /* make huge -- i18n can bulk up error messages a lot */
1586 char buf[2*MSGBUFSIZE+4];
1590 * stuffline() requires its input to be writeable (for CR stripping),
1591 * so we needed to copy the message to a writeable buffer anyway in
1592 * case it was a string constant. We make a virtue of that necessity
1593 * here by supporting stdargs/varargs.
1595 #if defined(HAVE_STDARG_H)
1600 vsnprintf(buf, sizeof(buf) - 2, fmt, ap);
1603 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1605 /* guard against very long lines */
1606 buf[MSGBUFSIZE+1] = '\r';
1607 buf[MSGBUFSIZE+2] = '\n';
1608 buf[MSGBUFSIZE+3] = '\0';
1610 stuffline(ctl, rfc2047charset != NULL ? rfc2047e(buf, rfc2047charset) : buf);
1613 void close_warning_by_mail(struct query *ctl, struct msgblk *msg)
1614 /* sign and send mailed warnings */
1616 stuff_warning(NULL, ctl, GT_("-- \nThe Fetchmail Daemon"));
1617 close_sink(ctl, msg, TRUE);
1620 /* sink.c ends here */