2 * driver.c -- generic driver for mail fetch method protocols
4 * Copyright 1996 by Eric S. Raymond
6 * For license terms, see the file COPYING in this directory.
15 #if defined(STDC_HEADERS)
18 #if defined(HAVE_UNISTD_H)
21 #if defined(HAVE_STDARG_H)
26 #if defined(HAVE_ALLOCA_H)
29 #if defined(HAVE_SYS_ITIMER_H)
30 #include <sys/itimer.h>
35 #ifdef HAVE_GETHOSTBYNAME
38 #endif /* HAVE_GETHOSTBYNAME */
47 #include <netinet/in.h>
49 #endif /* KERBEROS_V4 */
51 #include "fetchmail.h"
55 /* BSD portability hack...I know, this is an ugly place to put it */
56 #if !defined(SIGCHLD) && defined(SIGCLD)
57 #define SIGCHLD SIGCLD
60 #define SMTP_PORT 25 /* standard SMTP service port */
62 extern char *strstr(); /* needed on sysV68 R3V7.1. */
64 int fetchlimit; /* how often to tear down the server connection */
65 int batchcount; /* count of messages sent in current batch */
66 int peek_capable; /* can we peek for better error recovery? */
68 static const struct method *protocol;
69 static jmp_buf restart;
73 #define GENSYM (sprintf(tag, "a%04d", ++tagnum), tag)
75 static char *shroud; /* string to shroud in debug output, if non-NULL */
76 static int mytimeout; /* value of nonreponse timeout */
78 static void set_timeout(int timeleft)
79 /* reset the nonresponse-timeout */
81 struct itimerval ntimeout;
83 ntimeout.it_interval.tv_sec = ntimeout.it_interval.tv_usec = 0;
84 ntimeout.it_value.tv_sec = timeleft;
85 ntimeout.it_value.tv_usec = 0;
86 setitimer(ITIMER_REAL, &ntimeout, (struct itimerval *)NULL);
89 static void timeout_handler (int signal)
90 /* handle server-timeout SIGALRM signal */
97 #define XMIT_ANTISPAM 3
98 static int accept_count, reject_count;
100 #ifdef HAVE_RES_SEARCH
103 static int is_host_alias(const char *name, struct query *ctl)
104 /* determine whether name is a DNS alias of the hostname */
107 struct mxentry *mxp, *mxrecords;
110 * The first two checks are optimizations that will catch a good
111 * many cases. (1) check against the hostname the user
112 * specified. Odds are good this will either be the mailserver's
113 * FQDN or a suffix of it with the mailserver's domain's default
114 * host name omitted. Then check the rest of the `also known as'
115 * cache accumulated by previous DNS checks. This cache is primed
116 * by the aka list option.
118 * (2) check against the mailserver's FQDN, in case
119 * it's not the same as the declared hostname.
121 * Either of these on a mail address is definitive. Only if the
122 * name doesn't match either is it time to call the bind library.
123 * If this happens odds are good we're looking at an MX name.
125 if (str_in_list(&ctl->server.lead_server->names, name))
127 else if (strcmp(name, ctl->server.canonical_name) == 0)
129 else if (!ctl->server.dns)
133 * We know DNS service was up at the beginning of this poll cycle.
134 * If it's down, our nameserver has crashed. We don't want to try
135 * delivering the current message or anything else from this
136 * mailbox until it's back up.
138 else if ((he = gethostbyname(name)) != (struct hostent *)NULL)
140 if (strcmp(ctl->server.canonical_name, he->h_name) == 0)
148 case HOST_NOT_FOUND: /* specified host is unknown */
149 case NO_ADDRESS: /* valid, but does not have an IP address */
152 case NO_RECOVERY: /* non-recoverable name server error */
153 case TRY_AGAIN: /* temporary error on authoritative server */
155 if (outlevel != O_SILENT)
156 putchar('\n'); /* terminate the progress message */
158 "nameserver failure while looking for `%s' during poll of %s.",
159 name, ctl->server.names->id);
165 * We're only here if DNS was OK but the gethostbyname() failed
166 * with a HOST_NOT_FOUND or NO_ADDRESS error.
167 * Search for a name match on MX records pointing to the server.
170 if ((mxrecords = getmxrecords(name)) == (struct mxentry *)NULL)
174 case HOST_NOT_FOUND: /* specified host is unknown */
175 case NO_ADDRESS: /* valid, but does not have an IP address */
179 case NO_RECOVERY: /* non-recoverable name server error */
180 case TRY_AGAIN: /* temporary error on authoritative server */
183 "nameserver failure while looking for `%s' during poll of %s.",
184 name, ctl->server.names->id);
191 for (mxp = mxrecords; mxp->name; mxp++)
192 if (strcmp(ctl->server.canonical_name, mxp->name) == 0)
198 /* add this name to relevant server's `also known as' list */
199 save_str(&ctl->server.lead_server->names, -1, name);
203 static void map_name(name, ctl, xmit_names)
204 /* add given name to xmit_names if it matches declared localnames */
205 const char *name; /* name to map */
206 struct query *ctl; /* list of permissible aliases */
207 struct idlist **xmit_names; /* list of recipient names parsed out */
211 lname = idpair_find(&ctl->localnames, name);
212 if (!lname && ctl->wildcard)
215 if (lname != (char *)NULL)
217 if (outlevel == O_VERBOSE)
218 error(0, 0, "mapped %s to local %s", name, lname);
219 save_str(xmit_names, XMIT_ACCEPT, lname);
224 void find_server_names(hdr, ctl, xmit_names)
225 /* parse names out of a RFC822 header into an ID list */
226 const char *hdr; /* RFC822 header in question */
227 struct query *ctl; /* list of permissible aliases */
228 struct idlist **xmit_names; /* list of recipient names parsed out */
230 if (hdr == (char *)NULL)
236 if ((cp = nxtaddr(hdr)) != (char *)NULL)
240 if ((atsign = strchr(cp, '@')))
245 * Does a trailing segment of the hostname match something
246 * on the localdomains list? If so, save the whole name
249 for (idp = ctl->server.localdomains; idp; idp = idp->next)
253 rhs = atsign + (strlen(atsign) - strlen(idp->id));
254 if ((rhs[-1] == '.' || rhs[-1] == '@')
255 && strcasecmp(rhs, idp->id) == 0)
257 if (outlevel == O_VERBOSE)
258 error(0, 0, "passed through %s matching %s",
260 save_str(xmit_names, XMIT_ACCEPT, cp);
267 * Check to see if the right-hand part is an alias
268 * or MX equivalent of the mailserver. If it's
269 * not, skip this name. If it is, we'll keep
270 * going and try to find a mapping to a client name.
272 if (!is_host_alias(atsign+1, ctl))
274 save_str(xmit_names, XMIT_REJECT, cp);
281 map_name(cp, ctl, xmit_names);
283 ((cp = nxtaddr((char *)NULL)) != (char *)NULL);
287 char *parse_received(struct query *ctl, char *bufp)
288 /* try to extract real addressee from the Received line */
291 static char rbuf[HOSTLEN + USERNAMELEN + 4];
294 * Try to extract the real envelope addressee. We look here
295 * specifically for the mailserver's Received line.
296 * Note: this will only work for sendmail, or an MTA that
297 * shares sendmail's convention for embedding the envelope
298 * address in the Received line. Sendmail itself only
299 * does this when the mail has a single recipient.
301 if ((ok = strstr(bufp, "by ")) == (char *)NULL)
307 /* extract space-delimited token after "by " */
308 for (sp = ok + 3; isspace(*sp); sp++)
311 for (; !isspace(*sp); sp++)
316 * If it's a DNS name of the mail server, look for the
317 * recipient name after a following "for". Otherwise
320 if (is_host_alias(rbuf, ctl))
321 ok = strstr(sp, "for ");
334 while (*sp && *sp != '>' && *sp != '@' && *sp != ';')
339 /* uh oh -- whitespace here can't be right! */
350 if (outlevel == O_VERBOSE)
351 error(0, 0, "found Received address `%s'", rbuf);
355 #endif /* HAVE_RES_SEARCH */
357 int smtp_open(struct query *ctl)
358 /* try to open a socket to the appropriate SMTP server for this query */
362 /* maybe it's time to close the socket in order to force delivery */
363 if (ctl->batchlimit && (ctl->smtp_socket != -1) && batchcount++ == ctl->batchlimit)
365 close(ctl->smtp_socket);
366 ctl->smtp_socket = -1;
370 /* run down the SMTP hunt list looking for a server that's up */
371 for (idp = ctl->smtphunt; idp; idp = idp->next)
374 * RFC 1123 requires that the domain name in HELO address is a
375 * "valid principal domain name" for the client host. We
376 * violate this with malice aforethought in order to make the
377 * Received headers and logging look right.
379 * In fact this code relies on the RFC1123 requirement that the
380 * SMTP listener must accept messages even if verification of the
381 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
384 /* if no socket to this host is already set up, try to open ESMTP */
385 if (ctl->smtp_socket == -1)
387 if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
389 else if (SMTP_ok(ctl->smtp_socket) != SM_OK
390 || SMTP_ehlo(ctl->smtp_socket,
391 ctl->server.names->id,
392 &ctl->server.esmtp_options) != SM_OK)
395 * RFC 1869 warns that some listeners hang up on a failed EHLO,
396 * so it's safest not to assume the socket will still be good.
398 close(ctl->smtp_socket);
399 ctl->smtp_socket = -1;
403 ctl->smtphost = idp->id;
408 /* if opening for ESMTP failed, try SMTP */
409 if (ctl->smtp_socket == -1)
411 if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
413 else if (SMTP_ok(ctl->smtp_socket) != SM_OK
414 || SMTP_helo(ctl->smtp_socket, ctl->server.names->id) != SM_OK)
416 close(ctl->smtp_socket);
417 ctl->smtp_socket = -1;
421 ctl->smtphost = idp->id;
427 return(ctl->smtp_socket);
430 static int gen_readmsg(sock, len, delimited, ctl, realname)
431 /* read message content and ship to SMTP or MDA */
432 int sock; /* to which the server is connected */
433 long len; /* length of message */
434 int delimited; /* does the protocol use a message delimiter? */
435 struct query *ctl; /* query control record */
436 char *realname; /* real name of host */
438 char buf [MSGBUFSIZE+1];
439 int from_offs, to_offs, cc_offs, bcc_offs, ctt_offs, env_offs;
440 char *headers, *received_for, *return_path;
441 int n, linelen, oldlen, ch, sizeticker, delete_ok, remaining;
443 RETSIGTYPE (*sigchld)();
444 #ifdef HAVE_GETHOSTBYNAME
445 char rbuf[HOSTLEN + USERNAMELEN + 4];
446 #endif /* HAVE_GETHOSTBYNAME */
448 struct idlist *idp, *xmit_names;
449 int good_addresses, bad_addresses, has_nuls;
450 #ifdef HAVE_RES_SEARCH
451 int no_local_matches = FALSE;
452 #endif /* HAVE_RES_SEARCH */
459 olderrs = ctl->errcount;
461 /* read message headers */
462 headers = received_for = return_path = NULL;
463 from_offs = to_offs = cc_offs = bcc_offs = ctt_offs = env_offs = -1;
469 line = xmalloc(sizeof(buf));
473 if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1)
477 /* lines may not be properly CRLF terminated; fix this for qmail */
480 cp = buf + strlen(buf) - 1;
481 if (cp > buf && *cp == '\n' && cp[-1] != '\r')
489 set_timeout(ctl->server.timeout);
490 /* leave extra room for reply_hack to play with */
491 line = (char *) realloc(line, strlen(line) + strlen(buf) + HOSTLEN + 1);
493 if (line[0] == '\r' && line[1] == '\n')
496 /* we may need to grab RFC822 continuations */
497 ((ch = SockPeek(sock)) == ' ' || ch == '\t');
499 /* write the message size dots */
500 if ((outlevel > O_SILENT && outlevel < O_VERBOSE) && linelen > 0)
502 sizeticker += linelen;
503 while (sizeticker >= SIZETICKER)
506 sizeticker -= SIZETICKER;
510 if (linelen != strlen(line))
513 remaining -= linelen;
515 /* check for end of headers; don't save terminating line */
516 if (line[0] == '\r' && line[1] == '\n')
524 * OK, this is messy. If we're forwarding by SMTP, it's the
525 * SMTP-receiver's job (according to RFC821, page 22, section
526 * 4.1.1) to generate a Return-Path line on final delivery.
527 * The trouble is, we've already got one because the
528 * mailserver's SMTP thought *it* was responsible for final
531 * Stash away the contents of Return-Path for use in generating
532 * MAIL FROM later on, then prevent the header from being saved
533 * with the others. In effect, we strip it off here.
535 * If the SMTP server conforms to the standards, and fetchmail gets the
536 * envelope sender from the Return-Path, the new Return-Path should be
537 * exactly the same as the original one.
539 if (!ctl->mda && !strncasecmp("Return-Path:", line, 12))
541 return_path = xstrdup(nxtaddr(line));
546 reply_hack(line, realname);
550 oldlen = strlen(line);
551 headers = xmalloc(oldlen + 1);
552 (void) strcpy(headers, line);
560 newlen = oldlen + strlen(line);
561 headers = (char *) realloc(headers, newlen + 1);
564 strcpy(headers + oldlen, line);
566 line = headers + oldlen;
570 if (from_offs == -1 && !strncasecmp("From:", line, 5))
571 from_offs = (line - headers);
572 else if (from_offs == -1 && !strncasecmp("Resent-From:", line, 12))
573 from_offs = (line - headers);
574 else if (from_offs == -1 && !strncasecmp("Apparently-From:", line, 16))
575 from_offs = (line - headers);
577 else if (!strncasecmp("To:", line, 3))
578 to_offs = (line - headers);
580 else if (ctl->server.envelope != STRING_DISABLED && env_offs == -1
581 && !strncasecmp(ctl->server.envelope,
583 strlen(ctl->server.envelope)))
584 env_offs = (line - headers);
586 else if (!strncasecmp("Cc:", line, 3))
587 cc_offs = (line - headers);
589 else if (!strncasecmp("Bcc:", line, 4))
590 bcc_offs = (line - headers);
592 else if (!strncasecmp("Content-Transfer-Encoding:", line, 26))
593 ctt_offs = (line - headers);
595 #ifdef HAVE_RES_SEARCH
596 else if (ctl->server.envelope != STRING_DISABLED && MULTIDROP(ctl) && !received_for && !strncasecmp("Received:", line, 9))
597 received_for = parse_received(ctl, line);
598 #endif /* HAVE_RES_SEARCH */
602 * Hack time. If the first line of the message was blank, with no headers
603 * (this happens occasionally due to bad gatewaying software) cons up
604 * a set of fake headers.
606 * If you modify the fake header template below, be sure you don't
607 * make either From or To address @-less, otherwise the reply_hack
608 * logic will do bad things.
610 if (headers == (char *)NULL)
613 "From: <FETCHMAIL-DAEMON@%s>\r\nTo: %s@localhost\r\nSubject: Headerless mail from %s's mailbox on %s\r\n",
614 fetchmailhost, user, ctl->remotename, realname);
615 headers = xstrdup(buf);
619 * We can now process message headers before reading the text.
620 * In fact we have to, as this will tell us where to forward to.
623 /* cons up a list of local recipients */
624 xmit_names = (struct idlist *)NULL;
625 bad_addresses = good_addresses = accept_count = reject_count = 0;
626 #ifdef HAVE_RES_SEARCH
627 /* is this a multidrop box? */
630 if (env_offs > -1) /* We have the actual envelope addressee */
631 find_server_names(headers + env_offs, ctl, &xmit_names);
632 else if (received_for)
634 * We have the Received for addressee.
635 * It has to be a mailserver address, or we
636 * wouldn't have got here.
638 map_name(received_for, ctl, &xmit_names);
642 * We haven't extracted the envelope address.
643 * So check all the header addresses.
646 find_server_names(headers + to_offs, ctl, &xmit_names);
648 find_server_names(headers + cc_offs, ctl, &xmit_names);
650 find_server_names(headers + bcc_offs, ctl, &xmit_names);
654 no_local_matches = TRUE;
655 save_str(&xmit_names, XMIT_ACCEPT, user);
656 if (outlevel == O_VERBOSE)
658 "no local matches, forwarding to %s",
662 else /* it's a single-drop box, use first localname */
663 #endif /* HAVE_RES_SEARCH */
664 save_str(&xmit_names, XMIT_ACCEPT, ctl->localnames->id);
668 * Time to either address the message or decide we can't deliver it yet.
670 if (ctl->errcount > olderrs) /* there were DNS errors above */
673 sinkfp = (FILE *)NULL;
674 if (outlevel == O_VERBOSE)
675 error(0,0, "forwarding and deletion suppressed due to DNS errors");
677 else if (ctl->mda) /* we have a declared MDA */
683 * We go through this in order to be able to handle very
684 * long lists of users and (re)implement %s.
686 for (idp = xmit_names; idp; idp = idp->next)
687 if (idp->val.num == XMIT_ACCEPT)
688 length += (strlen(idp->id) + 1);
689 names = (char *)alloca(length);
691 for (idp = xmit_names; idp; idp = idp->next)
692 if (idp->val.num == XMIT_ACCEPT)
694 strcat(names, idp->id);
697 cmd = (char *)alloca(strlen(ctl->mda) + length);
698 sprintf(cmd, ctl->mda, names);
699 if (outlevel == O_VERBOSE)
700 error(0, 0, "about to deliver with: %s", cmd);
704 * Arrange to run with user's permissions if we're root.
705 * This will initialize the ownership of any files the
706 * MDA creates properly. (The seteuid call is available
707 * under all BSDs and Linux)
710 #endif /* HAVE_SETEUID */
712 sinkfp = popen(cmd, "w");
715 /* this will fail quietly if we didn't start as root */
717 #endif /* HAVE_SETEUID */
721 error(0, -1, "MDA open failed");
725 sigchld = signal(SIGCHLD, SIG_DFL);
729 char *ap, *ctt, options[MSGBUFSIZE];
732 /* build a connection to the SMTP listener */
733 if (!ctl->mda && (smtp_open(ctl) == -1))
735 free_str_list(&xmit_names);
736 error(0, -1, "SMTP connect to %s failed",
737 ctl->smtphost ? ctl->smtphost : "localhost");
744 * Compute ESMTP options. It's a kluge to use nxtaddr()
745 * here because the contents of the Content-Transfer-Encoding
746 * headers isn't semantically an address. But it has the
747 * desired tokenizing effect.
750 if ((ctl->server.esmtp_options & ESMTP_8BITMIME)
752 && (ctt = nxtaddr(headers + ctt_offs)))
753 if (!strcasecmp(ctt,"7BIT"))
754 sprintf(options, " BODY=7BIT", ctt);
755 else if (!strcasecmp(ctt,"8BIT"))
756 sprintf(options, " BODY=8BITMIME", ctt);
757 if ((ctl->server.esmtp_options & ESMTP_SIZE) && !delimited)
758 sprintf(options + strlen(options), " SIZE=%d", len);
761 * If there is a Return-Path address on the message, this was
762 * almost certainly the MAIL FROM address given the originating
763 * sendmail. This is the best thing to use for logging the
764 * message origin (it sets up the right behavior for bounces and
765 * mailing lists). Otherwise, take the From address.
767 * Try to get the SMTP listener to take the Return-Path or
768 * From address as MAIL FROM . If it won't, fall back on the
769 * calling-user ID. This won't affect replies, which use the
770 * header From address anyway.
772 * RFC 1123 requires that the domain name part of the
773 * MAIL FROM address be "canonicalized", that is a
774 * FQDN or MX but not a CNAME. We'll assume the From
775 * header is already in this form here (it certainly
776 * is if rewrite is on). RFC 1123 is silent on whether
777 * a nonexistent hostname part is considered canonical.
779 * This is a potential problem if the MTAs further upstream
780 * didn't pass canonicalized From/Return-Path lines, *and* the
781 * local SMTP listener insists on them.
786 else if (from_offs == -1 || !(ap = nxtaddr(headers + from_offs)))
788 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
790 int smtperr = atoi(smtp_response);
793 error(0, -1, "SMTP error: %s", smtp_response);
796 * There's one problem with this flow of control;
797 * there's no way to avoid reading the whole message
798 * off the server, even if the MAIL FROM response
799 * tells us that it's just to be discarded. We could
800 * fix this under IMAP by reading headers first, then
801 * trying to issue the MAIL FROM, and *then* reading
802 * the body...but POP3 can't do this.
807 case 571: /* unsolicited email refused */
809 * SMTP listener explicitly refuses to deliver
810 * mail coming from this address, probably due
811 * to an anti-spam domain exclusion. Respect
812 * this. Don't try to ship the message, and
813 * don't prevent it from being deleted.
815 sinkfp = (FILE *)NULL;
818 case 452: /* insufficient system storage */
820 * Temporary out-of-queue-space condition on the
821 * ESMTP server. Don't try to ship the message,
822 * and suppress deletion so it can be retried on
823 * a future retrieval cycle.
826 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
829 case 552: /* message exceeds fixed maximum message size */
831 * Permanent no-go condition on the
832 * ESMTP server. Don't try to ship the message,
833 * and allow it to be deleted.
835 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
838 default: /* retry with invoking user's address */
839 if (SMTP_from(ctl->smtp_socket, user, options) != SM_OK)
841 error(0, -1, "SMTP error: %s", smtp_response);
844 return(PS_SMTP); /* should never happen */
850 * Now list the recipient addressees
852 * RFC 1123 requires that the domain name part of the
853 * RCPT TO address be "canonicalized", that is a FQDN
854 * or MX but not a CNAME. RFC1123 doesn't say whether
855 * the FQDN part can be null (as it frequently will be
856 * here), but it's hard to see how this could cause a
859 for (idp = xmit_names; idp; idp = idp->next)
860 if (idp->val.num == XMIT_ACCEPT)
861 if (SMTP_rcpt(ctl->smtp_socket, idp->id) == SM_OK)
866 idp->val.num = XMIT_ANTISPAM;
868 "SMTP listener doesn't like recipient address `%s'", idp->id);
870 if (!good_addresses && SMTP_rcpt(ctl->smtp_socket, user) != SM_OK)
873 "can't even send to calling user!");
879 /* tell it we're ready to send data */
880 SMTP_data(ctl->smtp_socket);
887 /* we may need to strip carriage returns */
892 for (sp = tp = headers; *sp; sp++)
899 /* write all the headers */
901 if (ctl->mda && sinkfp)
902 n = fwrite(headers, 1, strlen(headers), sinkfp);
903 else if (ctl->smtp_socket != -1)
904 n = SockWrite(ctl->smtp_socket, headers, strlen(headers));
910 error(0, errno, "writing RFC822 headers");
914 signal(SIGCHLD, sigchld);
918 else if (outlevel == O_VERBOSE)
923 /* write error notifications */
924 #ifdef HAVE_RES_SEARCH
925 if (no_local_matches || has_nuls || bad_addresses)
927 if (has_nuls || bad_addresses)
928 #endif /* HAVE_RES_SEARCH */
931 char errhd[USERNAMELEN + POPBUFSIZE], *errmsg;
934 (void) strcpy(errhd, "X-Fetchmail-Warning: ");
935 #ifdef HAVE_RES_SEARCH
936 if (no_local_matches)
938 if (reject_count != 1)
939 strcat(errhd, "no recipient addresses matched declared local names");
942 for (idp = xmit_names; idp; idp = idp->next)
943 if (idp->val.num == XMIT_REJECT)
945 sprintf(errhd+strlen(errhd), "recipient address %s didn't match any local name", idp->id);
948 #endif /* HAVE_RES_SEARCH */
952 if (errhd[sizeof("X-Fetchmail-Warning: ")])
954 strcat(errhd, "message has embedded NULs");
959 if (errhd[sizeof("X-Fetchmail-Warning: ")])
961 strcat(errhd, "SMTP listener rejected local recipient addresses: ");
962 errlen = strlen(errhd);
963 for (idp = xmit_names; idp; idp = idp->next)
964 if (idp->val.num == XMIT_ANTISPAM)
965 errlen += strlen(idp->id) + 2;
967 errmsg = alloca(errlen+3);
968 (void) strcpy(errmsg, errhd);
969 for (idp = xmit_names; idp; idp = idp->next)
970 if (idp->val.num == XMIT_ANTISPAM)
972 strcat(errmsg, idp->id);
974 strcat(errmsg, ", ");
979 if (ctl->mda && !ctl->forcecr)
980 strcat(errmsg, "\n");
982 strcat(errmsg, "\r\n");
984 /* we may need to strip carriage returns */
989 for (sp = tp = errmsg; *sp; sp++)
995 /* ship out the error line */
999 fwrite(errmsg, sizeof(char), strlen(errmsg), sinkfp);
1001 SockWrite(ctl->smtp_socket, errmsg, strlen(errmsg));
1005 free_str_list(&xmit_names);
1007 /* issue the delimiter line */
1008 if (sinkfp && ctl->mda)
1009 fputc('\n', sinkfp);
1010 else if (ctl->smtp_socket != -1)
1013 SockWrite(ctl->smtp_socket, "\n", 1);
1015 SockWrite(ctl->smtp_socket, "\r\n", 2);
1019 * Body processing starts here
1022 /* pass through the text lines */
1023 while (delimited || remaining > 0)
1025 if ((linelen = SockRead(sock, buf, sizeof(buf)-1)) == -1)
1027 set_timeout(ctl->server.timeout);
1029 /* write the message size dots */
1032 sizeticker += linelen;
1033 while (sizeticker >= SIZETICKER)
1035 if (outlevel > O_SILENT)
1037 sizeticker -= SIZETICKER;
1040 remaining -= linelen;
1042 /* fix messages that have only \n line-termination (for qmail) */
1045 cp = buf + strlen(buf) - 1;
1046 if (cp > buf && *cp == '\n' && cp[-1] != '\r')
1054 /* check for end of message */
1055 if (delimited && *buf == '.')
1056 if (buf[1] == '\r' && buf[2] == '\n')
1059 /* ship out the text line */
1061 /* SMTP byte-stuffing */
1063 if (sinkfp && ctl->mda)
1065 else if (ctl->smtp_socket != -1)
1066 SockWrite(ctl->smtp_socket, buf, 1);
1068 /* we may need to strip carriage returns */
1073 for (sp = tp = buf; *sp; sp++)
1079 /* ship the text line */
1081 if (sinkfp && ctl->mda)
1082 n = fwrite(buf, 1, strlen(buf), sinkfp);
1083 else if (ctl->smtp_socket != -1)
1084 n = SockWrite(ctl->smtp_socket, buf, strlen(buf));
1088 error(0, errno, "writing message text");
1092 signal(SIGCHLD, sigchld);
1096 else if (outlevel == O_VERBOSE)
1101 * End-of-message processing starts here
1104 if (outlevel == O_VERBOSE)
1105 fputc('\n', stderr);
1111 /* close the delivery pipe, we'll reopen before next message */
1112 rc = pclose(sinkfp);
1113 signal(SIGCHLD, sigchld);
1116 error(0, -1, "MDA exited abnormally or returned nonzero status");
1120 else if (ctl->smtp_socket != -1)
1122 /* write message terminator */
1123 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1125 error(0, -1, "SMTP listener refused delivery");
1127 return(PS_TRANSIENT);
1131 return(delete_ok ? PS_SUCCESS : PS_TRANSIENT);
1136 kerberos_auth (socket, canonical)
1137 /* authenticate to the server host using Kerberos V4 */
1138 int socket; /* socket to server host */
1139 const char *canonical; /* server name */
1141 char * host_primary;
1145 Key_schedule schedule;
1148 ticket = ((KTEXT) (malloc (sizeof (KTEXT_ST))));
1149 rem = (krb_sendauth (0L, socket, ticket, "pop",
1151 ((char *) (krb_realmofhost (canonical))),
1152 ((unsigned long) 0),
1156 ((struct sockaddr_in *) 0),
1157 ((struct sockaddr_in *) 0),
1160 if (rem != KSUCCESS)
1162 error(0, -1, "kerberos error %s", (krb_get_err_text (rem)));
1167 #endif /* KERBEROS_V4 */
1169 int do_protocol(ctl, proto)
1170 /* retrieve messages from server using given protocol method table */
1171 struct query *ctl; /* parsed options with merged-in defaults */
1172 const struct method *proto; /* protocol method table */
1175 char *msg, *sp, *cp, realname[HOSTLEN];
1179 if (ctl->server.authenticate == A_KERBEROS_V4)
1181 error(0, -1, "Kerberos V4 support not linked.");
1184 #endif /* KERBEROS_V4 */
1186 /* lacking methods, there are some options that may fail */
1189 /* check for unsupported options */
1192 "Option --flush is not supported with %s",
1196 else if (ctl->fetchall) {
1198 "Option --all is not supported with %s",
1203 if (!proto->getsizes && ctl->limit)
1206 "Option --limit is not supported with %s",
1213 tag[0] = '\0'; /* nuke any tag hanging out from previous query */
1215 error_init(poll_interval == 0 && !logfile);
1217 /* set up the server-nonresponse timeout */
1218 sigsave = signal(SIGALRM, timeout_handler);
1219 set_timeout(mytimeout = ctl->server.timeout);
1221 if ((js = setjmp(restart)) == 1)
1224 "timeout after %d seconds waiting for %s.",
1225 ctl->server.timeout, ctl->server.names->id);
1230 char buf [POPBUFSIZE+1];
1231 int *msgsizes, len, num, count, new, deletions = 0;
1234 /* execute pre-initialization command, if any */
1235 if (ctl->preconnect && (ok = system(ctl->preconnect)))
1237 sprintf(buf, "pre-connection command failed with status %d", ok);
1243 /* open a socket to the mail server */
1244 port = ctl->server.port ? ctl->server.port : protocol->port;
1245 if ((sock = SockOpen(ctl->server.names->id, port)) == -1)
1247 #ifndef EHOSTUNREACH
1248 #define EHOSTUNREACH (-1)
1250 if (outlevel == O_VERBOSE || errno != EHOSTUNREACH)
1251 error(0, errno, "connecting to host");
1257 if (ctl->server.authenticate == A_KERBEROS_V4)
1259 ok = kerberos_auth(sock, ctl->server.canonical_name);
1262 set_timeout(ctl->server.timeout);
1264 #endif /* KERBEROS_V4 */
1266 /* accept greeting message from mail server */
1267 ok = (protocol->parse_response)(sock, buf);
1270 set_timeout(ctl->server.timeout);
1273 * Try to parse the host's actual name out of the greeting
1274 * message. We do this so that the progress messages will
1275 * make sense even if the connection is indirected through
1276 * ssh. *Do* use this for hacking reply headers, but *don't*
1277 * use it for error logging, as the names in the log should
1278 * correlate directly back to rc file entries.
1280 * This assumes that the first space-delimited token found
1281 * that contains at least two dots (with the characters on
1282 * each side of the dot alphanumeric to exclude version
1283 * numbers) is the hostname. The hostname candidate may not
1284 * contain @ -- if it does it's probably a mailserver
1285 * maintainer's name. If no such token is found, fall back on
1286 * the .fetchmailrc id.
1289 for (cp = buf; *cp; cp++)
1293 case 0: /* skip to end of current token */
1298 case 1: /* look for blank-delimited token */
1306 case 2: /* look for first dot */
1309 else if (*cp == ' ')
1311 else if (*cp == '.' && isalpha(cp[1]) && isalpha(cp[-1]))
1315 case 3: /* look for second dot */
1318 else if (*cp == ' ')
1320 else if (*cp == '.' && isalpha(cp[1]) && isalpha(cp[-1]))
1324 case 4: /* look for trailing space */
1327 else if (*cp == ' ')
1338 char *tp = realname;
1345 strcpy(realname, ctl->server.names->id);
1347 /* try to get authorized to fetch mail */
1348 if (protocol->getauth)
1350 shroud = ctl->password;
1351 ok = (protocol->getauth)(sock, ctl, buf);
1352 shroud = (char *)NULL;
1357 error(0, -1, "Authorization failure on %s@%s",
1362 set_timeout(ctl->server.timeout);
1365 /* compute number of messages and number of new messages waiting */
1366 ok = (protocol->getrange)(sock, ctl, &count, &new);
1369 set_timeout(ctl->server.timeout);
1371 /* show user how many messages we downloaded */
1372 if (outlevel > O_SILENT)
1373 if (count == -1) /* only used for ETRN */
1374 error(0, 0, "Polling %s@%s",
1377 else if (count == 0)
1378 error(0, 0, "No mail at %s@%s",
1383 if (new != -1 && (count - new) > 0)
1384 error(0, 0, "%d message%s (%d seen) at %s@%s.",
1385 count, count > 1 ? "s" : "", count-new,
1389 error(0, 0, "%d message%s at %s@%s.",
1390 count, count > 1 ? "s" : "",
1395 /* we may need to get sizes in order to check message limits */
1396 msgsizes = (int *)NULL;
1397 if (!ctl->fetchall && proto->getsizes && ctl->limit)
1399 msgsizes = (int *)alloca(sizeof(int) * count);
1401 ok = (proto->getsizes)(sock, count, msgsizes);
1404 set_timeout(ctl->server.timeout);
1409 if (new == -1 || ctl->fetchall)
1411 ok = ((new > 0) ? PS_SUCCESS : PS_NOMAIL);
1416 int force_retrieval, fetches;
1419 * What forces this code is that in POP3 and IMAP2BIS you can't
1420 * fetch a message without having it marked `seen'. In IMAP4,
1421 * on the other hand, you can (peek_capable is set to convey
1424 * The result of being unable to peek is that if there's
1425 * any kind of transient error (DNS lookup failure, or
1426 * sendmail refusing delivery due to process-table limits)
1427 * the message will be marked "seen" on the server without
1428 * having been delivered. This is not a big problem if
1429 * fetchmail is running in foreground, because the user
1430 * will see a "skipped" message when it next runs and get
1433 * But in daemon mode this leads to the message being silently
1434 * ignored forever. This is not acceptable.
1436 * We compensate for this by checking the error count from the
1437 * previous pass and forcing all messages to be considered new
1440 force_retrieval = !peek_capable && (ctl->errcount > 0);
1442 ctl->errcount = fetches = 0;
1444 /* read, forward, and delete messages */
1445 for (num = 1; num <= count; num++)
1447 int toolarge = msgsizes && (msgsizes[num-1] > ctl->limit);
1448 int fetch_it = ctl->fetchall ||
1449 (!toolarge && (force_retrieval || !(protocol->is_old && (protocol->is_old)(sock,ctl,num))));
1450 int suppress_delete = FALSE;
1452 /* we may want to reject this message if it's old */
1455 if (outlevel > O_SILENT)
1457 error_build("skipping message %d", num);
1459 error_build(" (oversized, %d bytes)", msgsizes[num-1]);
1464 /* request a message */
1465 ok = (protocol->fetch)(sock, ctl, num, &len);
1468 set_timeout(ctl->server.timeout);
1470 if (outlevel > O_SILENT)
1472 error_build("reading message %d", num);
1474 error_build(" (%d bytes)", len);
1475 if (outlevel == O_VERBOSE)
1476 error_complete(0, 0, "");
1481 /* read the message and ship it to the output sink */
1482 ok = gen_readmsg(sock,
1484 protocol->delimited,
1487 if (ok == PS_TRANSIENT)
1488 suppress_delete = TRUE;
1491 set_timeout(ctl->server.timeout);
1493 /* tell the server we got it OK and resynchronize */
1494 if (protocol->trail)
1496 ok = (protocol->trail)(sock, ctl, num);
1499 set_timeout(ctl->server.timeout);
1506 * At this point in flow of control, either we've bombed
1507 * on a protocol error or had delivery refused by the SMTP
1508 * server (unlikely -- I've never seen it) or we've seen
1509 * `accepted for delivery' and the message is shipped.
1510 * It's safe to mark the message seen and delete it on the
1514 /* maybe we delete this message now? */
1515 if (protocol->delete
1517 && (fetch_it ? !ctl->keep : ctl->flush))
1520 if (outlevel > O_SILENT)
1521 error_complete(0, 0, " flushed");
1522 ok = (protocol->delete)(sock, ctl, num);
1525 set_timeout(ctl->server.timeout);
1526 delete_str(&ctl->newsaved, num);
1528 else if (outlevel > O_SILENT)
1529 error_complete(0, 0, " not flushed");
1531 /* perhaps this as many as we're ready to handle */
1532 if (ctl->fetchlimit && ctl->fetchlimit <= fetches)
1536 ok = gen_transact(sock, protocol->exit_cmd);
1538 ok = (fetches > 0) ? PS_SUCCESS : PS_NOMAIL;
1544 ok = gen_transact(sock, protocol->exit_cmd);
1553 set_timeout(ctl->server.timeout);
1554 if (ok != 0 && ok != PS_SOCKET)
1555 gen_transact(sock, protocol->exit_cmd);
1566 msg = "authorization";
1569 msg = "missing or bad RFC822 header";
1575 msg = "client/server synchronization";
1578 msg = "client/server protocol";
1581 msg = "SMTP transaction";
1584 error(0, 0, "undefined");
1587 if (ok==PS_SOCKET || ok==PS_AUTHFAIL || ok==PS_SYNTAX || ok==PS_IOERR
1588 || ok==PS_ERROR || ok==PS_PROTOCOL || ok==PS_SMTP)
1589 error(0, -1, "%s error while fetching from %s", msg, ctl->server.names->id);
1592 signal(SIGALRM, sigsave);
1596 #if defined(HAVE_STDARG_H)
1597 void gen_send(int sock, char *fmt, ... )
1598 /* assemble command in printf(3) style and send to the server */
1600 void gen_send(sock, fmt, va_alist)
1601 /* assemble command in printf(3) style and send to the server */
1602 int sock; /* socket to which server is connected */
1603 const char *fmt; /* printf-style format */
1607 char buf [POPBUFSIZE+1];
1610 if (protocol->tagged)
1611 (void) sprintf(buf, "%s ", GENSYM);
1615 #if defined(HAVE_STDARG_H)
1620 vsprintf(buf + strlen(buf), fmt, ap);
1623 strcat(buf, "\r\n");
1624 SockWrite(sock, buf, strlen(buf));
1626 if (outlevel == O_VERBOSE)
1630 if (shroud && shroud[0] && (cp = strstr(buf, shroud)))
1634 sp = cp + strlen(shroud);
1640 buf[strlen(buf)-2] = '\0';
1641 error(0, 0, "%s> %s", protocol->name, buf);
1645 int gen_recv(sock, buf, size)
1646 /* get one line of input from the server */
1647 int sock; /* socket to which server is connected */
1648 char *buf; /* buffer to receive input */
1649 int size; /* length of buffer */
1651 if (SockRead(sock, buf, size) == -1)
1655 if (buf[strlen(buf)-1] == '\n')
1656 buf[strlen(buf)-1] = '\0';
1657 if (buf[strlen(buf)-1] == '\r')
1658 buf[strlen(buf)-1] = '\r';
1659 if (outlevel == O_VERBOSE)
1660 error(0, 0, "%s< %s", protocol->name, buf);
1665 #if defined(HAVE_STDARG_H)
1666 int gen_transact(int sock, char *fmt, ... )
1667 /* assemble command in printf(3) style, send to server, accept a response */
1669 int gen_transact(int sock, fmt, va_alist)
1670 /* assemble command in printf(3) style, send to server, accept a response */
1671 int sock; /* socket to which server is connected */
1672 const char *fmt; /* printf-style format */
1677 char buf [POPBUFSIZE+1];
1680 if (protocol->tagged)
1681 (void) sprintf(buf, "%s ", GENSYM);
1685 #if defined(HAVE_STDARG_H)
1690 vsprintf(buf + strlen(buf), fmt, ap);
1693 strcat(buf, "\r\n");
1694 SockWrite(sock, buf, strlen(buf));
1696 if (outlevel == O_VERBOSE)
1700 if (shroud && shroud[0] && (cp = strstr(buf, shroud)))
1704 sp = cp + strlen(shroud);
1710 buf[strlen(buf)-1] = '\0';
1711 error(0, 0, "%s> %s", protocol->name, buf);
1714 /* we presume this does its own response echoing */
1715 ok = (protocol->parse_response)(sock, buf);
1716 set_timeout(mytimeout);
1721 /* driver.c ends here */