2 * driver.c -- generic driver for mail fetch method protocols
4 * Copyright 1997 by Eric S. Raymond
5 * For license terms, see the file COPYING in this directory.
14 #if defined(STDC_HEADERS)
17 #if defined(HAVE_UNISTD_H)
20 #if defined(HAVE_STDARG_H)
25 #if defined(HAVE_ALLOCA_H)
28 #if defined(HAVE_SYS_ITIMER_H)
29 #include <sys/itimer.h>
34 #ifdef HAVE_GETHOSTBYNAME
37 #endif /* HAVE_GETHOSTBYNAME */
46 #include <netinet/in.h>
48 #endif /* KERBEROS_V4 */
50 #include "fetchmail.h"
54 /* BSD portability hack...I know, this is an ugly place to put it */
55 #if !defined(SIGCHLD) && defined(SIGCLD)
56 #define SIGCHLD SIGCLD
59 #define SMTP_PORT 25 /* standard SMTP service port */
61 extern char *strstr(); /* needed on sysV68 R3V7.1. */
63 int fetchlimit; /* how often to tear down the server connection */
64 int batchcount; /* count of messages sent in current batch */
65 bool peek_capable; /* can we peek for better error recovery? */
67 static const struct method *protocol;
68 static jmp_buf restart;
72 #define GENSYM (sprintf(tag, "a%04d", ++tagnum), tag)
74 static char *shroud; /* string to shroud in debug output, if non-NULL */
75 static int mytimeout; /* value of nonreponse timeout */
77 static void set_timeout(int timeleft)
78 /* reset the nonresponse-timeout */
80 struct itimerval ntimeout;
82 ntimeout.it_interval.tv_sec = ntimeout.it_interval.tv_usec = 0;
83 ntimeout.it_value.tv_sec = timeleft;
84 ntimeout.it_value.tv_usec = 0;
85 setitimer(ITIMER_REAL, &ntimeout, (struct itimerval *)NULL);
88 static void timeout_handler (int signal)
89 /* handle server-timeout SIGALRM signal */
96 #define XMIT_ANTISPAM 3
97 static int accept_count, reject_count;
99 #ifdef HAVE_RES_SEARCH
102 static int is_host_alias(const char *name, struct query *ctl)
103 /* determine whether name is a DNS alias of the hostname */
106 struct mxentry *mxp, *mxrecords;
109 * The first two checks are optimizations that will catch a good
110 * many cases. (1) check against the hostname the user
111 * specified. Odds are good this will either be the mailserver's
112 * FQDN or a suffix of it with the mailserver's domain's default
113 * host name omitted. Then check the rest of the `also known as'
114 * cache accumulated by previous DNS checks. This cache is primed
115 * by the aka list option.
117 * (2) check against the mailserver's FQDN, in case
118 * it's not the same as the declared hostname.
120 * Either of these on a mail address is definitive. Only if the
121 * name doesn't match either is it time to call the bind library.
122 * If this happens odds are good we're looking at an MX name.
124 if (str_in_list(&ctl->server.lead_server->names, name))
126 else if (strcmp(name, ctl->server.canonical_name) == 0)
128 else if (!ctl->server.dns)
132 * We know DNS service was up at the beginning of this poll cycle.
133 * If it's down, our nameserver has crashed. We don't want to try
134 * delivering the current message or anything else from this
135 * mailbox until it's back up.
137 else if ((he = gethostbyname(name)) != (struct hostent *)NULL)
139 if (strcmp(ctl->server.canonical_name, he->h_name) == 0)
147 case HOST_NOT_FOUND: /* specified host is unknown */
148 case NO_ADDRESS: /* valid, but does not have an IP address */
151 case NO_RECOVERY: /* non-recoverable name server error */
152 case TRY_AGAIN: /* temporary error on authoritative server */
154 if (outlevel != O_SILENT)
155 putchar('\n'); /* terminate the progress message */
157 "nameserver failure while looking for `%s' during poll of %s.",
158 name, ctl->server.names->id);
164 * We're only here if DNS was OK but the gethostbyname() failed
165 * with a HOST_NOT_FOUND or NO_ADDRESS error.
166 * Search for a name match on MX records pointing to the server.
169 if ((mxrecords = getmxrecords(name)) == (struct mxentry *)NULL)
173 case HOST_NOT_FOUND: /* specified host is unknown */
174 case NO_ADDRESS: /* valid, but does not have an IP address */
178 case NO_RECOVERY: /* non-recoverable name server error */
179 case TRY_AGAIN: /* temporary error on authoritative server */
182 "nameserver failure while looking for `%s' during poll of %s.",
183 name, ctl->server.names->id);
190 for (mxp = mxrecords; mxp->name; mxp++)
191 if (strcmp(ctl->server.canonical_name, mxp->name) == 0)
197 /* add this name to relevant server's `also known as' list */
198 save_str(&ctl->server.lead_server->names, -1, name);
202 static void map_name(name, ctl, xmit_names)
203 /* add given name to xmit_names if it matches declared localnames */
204 const char *name; /* name to map */
205 struct query *ctl; /* list of permissible aliases */
206 struct idlist **xmit_names; /* list of recipient names parsed out */
210 lname = idpair_find(&ctl->localnames, name);
211 if (!lname && ctl->wildcard)
214 if (lname != (char *)NULL)
216 if (outlevel == O_VERBOSE)
217 error(0, 0, "mapped %s to local %s", name, lname);
218 save_str(xmit_names, XMIT_ACCEPT, lname);
223 void find_server_names(hdr, ctl, xmit_names)
224 /* parse names out of a RFC822 header into an ID list */
225 const char *hdr; /* RFC822 header in question */
226 struct query *ctl; /* list of permissible aliases */
227 struct idlist **xmit_names; /* list of recipient names parsed out */
229 if (hdr == (char *)NULL)
235 if ((cp = nxtaddr(hdr)) != (char *)NULL)
239 if ((atsign = strchr(cp, '@')))
244 * Does a trailing segment of the hostname match something
245 * on the localdomains list? If so, save the whole name
248 for (idp = ctl->server.localdomains; idp; idp = idp->next)
252 rhs = atsign + (strlen(atsign) - strlen(idp->id));
253 if ((rhs[-1] == '.' || rhs[-1] == '@')
254 && strcasecmp(rhs, idp->id) == 0)
256 if (outlevel == O_VERBOSE)
257 error(0, 0, "passed through %s matching %s",
259 save_str(xmit_names, XMIT_ACCEPT, cp);
266 * Check to see if the right-hand part is an alias
267 * or MX equivalent of the mailserver. If it's
268 * not, skip this name. If it is, we'll keep
269 * going and try to find a mapping to a client name.
271 if (!is_host_alias(atsign+1, ctl))
273 save_str(xmit_names, XMIT_REJECT, cp);
280 map_name(cp, ctl, xmit_names);
282 ((cp = nxtaddr((char *)NULL)) != (char *)NULL);
286 char *parse_received(struct query *ctl, char *bufp)
287 /* try to extract real addressee from the Received line */
290 static char rbuf[HOSTLEN + USERNAMELEN + 4];
293 * Try to extract the real envelope addressee. We look here
294 * specifically for the mailserver's Received line.
295 * Note: this will only work for sendmail, or an MTA that
296 * shares sendmail's convention for embedding the envelope
297 * address in the Received line. Sendmail itself only
298 * does this when the mail has a single recipient.
300 if ((ok = strstr(bufp, "by ")) == (char *)NULL)
306 /* extract space-delimited token after "by " */
307 for (sp = ok + 3; isspace(*sp); sp++)
310 for (; !isspace(*sp); sp++)
315 * If it's a DNS name of the mail server, look for the
316 * recipient name after a following "for". Otherwise
319 if (is_host_alias(rbuf, ctl))
320 ok = strstr(sp, "for ");
333 while (*sp && *sp != '>' && *sp != '@' && *sp != ';')
338 /* uh oh -- whitespace here can't be right! */
349 if (outlevel == O_VERBOSE)
350 error(0, 0, "found Received address `%s'", rbuf);
354 #endif /* HAVE_RES_SEARCH */
356 int smtp_open(struct query *ctl)
357 /* try to open a socket to the appropriate SMTP server for this query */
361 /* maybe it's time to close the socket in order to force delivery */
362 if (ctl->batchlimit > 0 && (ctl->smtp_socket != -1) && batchcount++ == ctl->batchlimit)
364 close(ctl->smtp_socket);
365 ctl->smtp_socket = -1;
369 /* run down the SMTP hunt list looking for a server that's up */
370 for (idp = ctl->smtphunt; idp; idp = idp->next)
373 * RFC 1123 requires that the domain name in HELO address is a
374 * "valid principal domain name" for the client host. We
375 * violate this with malice aforethought in order to make the
376 * Received headers and logging look right.
378 * In fact this code relies on the RFC1123 requirement that the
379 * SMTP listener must accept messages even if verification of the
380 * HELO name fails (RFC1123 section 5.2.5, paragraph 2).
383 /* if no socket to this host is already set up, try to open ESMTP */
384 if (ctl->smtp_socket == -1)
386 if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
388 else if (SMTP_ok(ctl->smtp_socket) != SM_OK
389 || SMTP_ehlo(ctl->smtp_socket,
390 ctl->server.names->id,
391 &ctl->server.esmtp_options) != SM_OK)
394 * RFC 1869 warns that some listeners hang up on a failed EHLO,
395 * so it's safest not to assume the socket will still be good.
397 close(ctl->smtp_socket);
398 ctl->smtp_socket = -1;
402 ctl->smtphost = idp->id;
407 /* if opening for ESMTP failed, try SMTP */
408 if (ctl->smtp_socket == -1)
410 if ((ctl->smtp_socket = SockOpen(idp->id,SMTP_PORT)) == -1)
412 else if (SMTP_ok(ctl->smtp_socket) != SM_OK
413 || SMTP_helo(ctl->smtp_socket, ctl->server.names->id) != SM_OK)
415 close(ctl->smtp_socket);
416 ctl->smtp_socket = -1;
420 ctl->smtphost = idp->id;
426 return(ctl->smtp_socket);
429 /* these are shared by readheaders and readbody */
431 static RETSIGTYPE (*sigchld)();
432 static int sizeticker;
434 static int readheaders(sock, len, ctl, realname)
435 /* read message headers and ship to SMTP or MDA */
436 int sock; /* to which the server is connected */
437 long len; /* length of message */
438 struct query *ctl; /* query control record */
439 char *realname; /* real name of host */
441 char buf[MSGBUFSIZE+1], return_path[MSGBUFSIZE+1];
442 int from_offs, ctt_offs, env_offs, addressoffs[128], next_address;
443 char *headers, *received_for;
444 int n, linelen, oldlen, ch, remaining;
446 struct idlist *idp, *xmit_names;
447 bool good_addresses, bad_addresses, has_nuls;
448 #ifdef HAVE_RES_SEARCH
449 bool no_local_matches = FALSE;
450 #endif /* HAVE_RES_SEARCH */
453 next_address = sizeticker = 0;
455 return_path[0] = '\0';
456 olderrs = ctl->errcount;
458 /* read message headers */
459 headers = received_for = NULL;
460 from_offs = ctt_offs = env_offs = -1;
462 for (remaining = len; remaining > 0; remaining -= linelen)
466 line = xmalloc(sizeof(buf));
470 if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1)
474 /* lines may not be properly CRLF terminated; fix this for qmail */
477 cp = buf + strlen(buf) - 1;
478 if (*cp == '\n' && (cp == buf || cp[-1] != '\r'))
486 set_timeout(ctl->server.timeout);
487 /* leave extra room for reply_hack to play with */
488 line = (char *) realloc(line, strlen(line) + strlen(buf) + HOSTLEN + 1);
490 if (line[0] == '\r' && line[1] == '\n')
493 /* we may need to grab RFC822 continuations */
494 ((ch = SockPeek(sock)) == ' ' || ch == '\t');
496 /* write the message size dots */
497 if ((outlevel > O_SILENT && outlevel < O_VERBOSE) && linelen > 0)
499 sizeticker += linelen;
500 while (sizeticker >= SIZETICKER)
503 sizeticker -= SIZETICKER;
507 if (linelen != strlen(line))
510 /* check for end of headers; don't save terminating line */
511 if (line[0] == '\r' && line[1] == '\n')
518 * This code prevents fetchmail from becoming an accessory after
519 * the fact to upstream sendmails with the `E' option on. This
520 * can result in an escaped Unix From_ line at the beginning of
521 * the headers. If fetchmail just passes it through, the client
522 * listener may think the message has *no* headers (since the first)
523 * line it sees doesn't look RFC822-conformant) and fake up a set.
525 * What the user would see in this case is bogus (synthesized)
526 * headers, followed by a blank line, followed by the >From,
527 * followed by the real headers, followed by a blank line,
530 * We forestall this lossage by tossing anything that looks
531 * like an escaped From_ line in headers. These aren't RFC822
532 * so our conscience is clear...
534 if (!strncasecmp(line, ">From ", 6))
541 * OK, this is messy. If we're forwarding by SMTP, it's the
542 * SMTP-receiver's job (according to RFC821, page 22, section
543 * 4.1.1) to generate a Return-Path line on final delivery.
544 * The trouble is, we've already got one because the
545 * mailserver's SMTP thought *it* was responsible for final
548 * Stash away the contents of Return-Path for use in generating
549 * MAIL FROM later on, then prevent the header from being saved
550 * with the others. In effect, we strip it off here.
552 * If the SMTP server conforms to the standards, and fetchmail gets the
553 * envelope sender from the Return-Path, the new Return-Path should be
554 * exactly the same as the original one.
556 if (!ctl->mda && !strncasecmp("Return-Path:", line, 12))
558 strcpy(return_path, nxtaddr(line));
564 reply_hack(line, realname);
568 oldlen = strlen(line);
569 headers = xmalloc(oldlen + 1);
570 (void) strcpy(headers, line);
578 newlen = oldlen + strlen(line);
579 headers = (char *) realloc(headers, newlen + 1);
582 strcpy(headers + oldlen, line);
584 line = headers + oldlen;
588 if (from_offs == -1 && !strncasecmp("From:", line, 5))
589 from_offs = (line - headers);
590 else if (from_offs == -1 && !strncasecmp("Resent-From:", line, 12))
591 from_offs = (line - headers);
592 else if (from_offs == -1 && !strncasecmp("Apparently-From:", line, 16))
593 from_offs = (line - headers);
595 else if (ctl->server.envelope != STRING_DISABLED && env_offs == -1
596 && !strncasecmp(ctl->server.envelope,
598 strlen(ctl->server.envelope)))
599 env_offs = (line - headers);
601 else if (!strncasecmp("To:", line, 3))
603 if (next_address >= sizeof(addressoffs)/sizeof(addressoffs[0]))
604 error(PS_UNDEFINED, errno, "too many destination headers");
605 addressoffs[next_address++] = (line - headers);
608 else if (!strncasecmp("Cc:", line, 3))
610 if (next_address >= sizeof(addressoffs)/sizeof(addressoffs[0]))
611 error(PS_UNDEFINED, errno, "too many destination headers");
612 addressoffs[next_address++] = (line - headers);
615 else if (!strncasecmp("Bcc:", line, 4))
617 if (next_address >= sizeof(addressoffs)/sizeof(addressoffs[0]))
618 error(PS_UNDEFINED, errno, "too many destination headers");
619 addressoffs[next_address++] = (line - headers);
622 else if (!strncasecmp("Content-Transfer-Encoding:", line, 26))
623 ctt_offs = (line - headers);
625 #ifdef HAVE_RES_SEARCH
626 else if (ctl->server.envelope != STRING_DISABLED && MULTIDROP(ctl) && !received_for && !strncasecmp("Received:", line, 9))
627 received_for = parse_received(ctl, line);
628 #endif /* HAVE_RES_SEARCH */
632 * Hack time. If the first line of the message was blank, with no headers
633 * (this happens occasionally due to bad gatewaying software) cons up
634 * a set of fake headers.
636 * If you modify the fake header template below, be sure you don't
637 * make either From or To address @-less, otherwise the reply_hack
638 * logic will do bad things.
640 if (headers == (char *)NULL)
643 "From: <FETCHMAIL-DAEMON@%s>\r\nTo: %s@localhost\r\nSubject: Headerless mail from %s's mailbox on %s\r\n",
644 fetchmailhost, user, ctl->remotename, realname);
645 headers = xstrdup(buf);
649 * We can now process message headers before reading the text.
650 * In fact we have to, as this will tell us where to forward to.
653 /* cons up a list of local recipients */
654 xmit_names = (struct idlist *)NULL;
655 bad_addresses = good_addresses = accept_count = reject_count = 0;
656 #ifdef HAVE_RES_SEARCH
657 /* is this a multidrop box? */
660 if (env_offs > -1) /* We have the actual envelope addressee */
661 find_server_names(headers + env_offs, ctl, &xmit_names);
662 else if (received_for)
664 * We have the Received for addressee.
665 * It has to be a mailserver address, or we
666 * wouldn't have got here.
668 map_name(received_for, ctl, &xmit_names);
674 * We haven't extracted the envelope address.
675 * So check all the header addresses.
677 for (i = 0; i < next_address; i++)
678 find_server_names(headers + addressoffs[i], ctl, &xmit_names);
682 no_local_matches = TRUE;
683 save_str(&xmit_names, XMIT_ACCEPT, user);
684 if (outlevel == O_VERBOSE)
686 "no local matches, forwarding to %s",
690 else /* it's a single-drop box, use first localname */
691 #endif /* HAVE_RES_SEARCH */
692 save_str(&xmit_names, XMIT_ACCEPT, ctl->localnames->id);
696 * Time to either address the message or decide we can't deliver it yet.
698 if (ctl->errcount > olderrs) /* there were DNS errors above */
700 if (outlevel == O_VERBOSE)
701 error(0,0, "forwarding and deletion suppressed due to DNS errors");
703 return(PS_TRANSIENT);
705 else if (ctl->mda) /* we have a declared MDA */
711 * We go through this in order to be able to handle very
712 * long lists of users and (re)implement %s.
714 for (idp = xmit_names; idp; idp = idp->next)
715 if (idp->val.num == XMIT_ACCEPT)
716 length += (strlen(idp->id) + 1);
717 names = (char *)alloca(length);
719 for (idp = xmit_names; idp; idp = idp->next)
720 if (idp->val.num == XMIT_ACCEPT)
722 strcat(names, idp->id);
725 cmd = (char *)alloca(strlen(ctl->mda) + length);
726 sprintf(cmd, ctl->mda, names);
727 if (outlevel == O_VERBOSE)
728 error(0, 0, "about to deliver with: %s", cmd);
732 * Arrange to run with user's permissions if we're root.
733 * This will initialize the ownership of any files the
734 * MDA creates properly. (The seteuid call is available
735 * under all BSDs and Linux)
738 #endif /* HAVE_SETEUID */
740 sinkfp = popen(cmd, "w");
743 /* this will fail quietly if we didn't start as root */
745 #endif /* HAVE_SETEUID */
749 error(0, -1, "MDA open failed");
753 sigchld = signal(SIGCHLD, SIG_DFL);
757 char *ap, *ctt, options[MSGBUFSIZE];
759 /* build a connection to the SMTP listener */
760 if ((smtp_open(ctl) == -1))
762 free_str_list(&xmit_names);
763 error(0, -1, "SMTP connect to %s failed",
764 ctl->smtphost ? ctl->smtphost : "localhost");
769 * Compute ESMTP options. It's a kluge to use nxtaddr()
770 * here because the contents of the Content-Transfer-Encoding
771 * headers isn't semantically an address. But it has the
772 * desired tokenizing effect.
775 if ((ctl->server.esmtp_options & ESMTP_8BITMIME)
777 && (ctt = nxtaddr(headers + ctt_offs)))
778 if (!strcasecmp(ctt,"7BIT"))
779 sprintf(options, " BODY=7BIT");
780 else if (!strcasecmp(ctt,"8BIT"))
781 sprintf(options, " BODY=8BITMIME");
782 if ((ctl->server.esmtp_options & ESMTP_SIZE))
783 sprintf(options + strlen(options), " SIZE=%ld", len);
786 * If there is a Return-Path address on the message, this was
787 * almost certainly the MAIL FROM address given the originating
788 * sendmail. This is the best thing to use for logging the
789 * message origin (it sets up the right behavior for bounces and
790 * mailing lists). Otherwise, take the From address.
792 * Try to get the SMTP listener to take the Return-Path or
793 * From address as MAIL FROM . If it won't, fall back on the
794 * calling-user ID. This won't affect replies, which use the
795 * header From address anyway.
797 * RFC 1123 requires that the domain name part of the
798 * MAIL FROM address be "canonicalized", that is a
799 * FQDN or MX but not a CNAME. We'll assume the From
800 * header is already in this form here (it certainly
801 * is if rewrite is on). RFC 1123 is silent on whether
802 * a nonexistent hostname part is considered canonical.
804 * This is a potential problem if the MTAs further upstream
805 * didn't pass canonicalized From/Return-Path lines, *and* the
806 * local SMTP listener insists on them.
811 else if (from_offs == -1 || !(ap = nxtaddr(headers + from_offs)))
813 if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK)
815 int smtperr = atoi(smtp_response);
818 * Suppress error message only if the response specifically
819 * means `excluded for policy reasons'. We *should* see
820 * an error when the return code is less specific.
822 if (smtperr >= 400 && smtperr != 571)
823 error(0, -1, "SMTP error: %s", smtp_response);
827 case 571: /* sendmail's "unsolicited email refused" */
828 case 501: /* exim's old antispam response */
829 case 550: /* exim's new antispam response (temporary) */
831 * SMTP listener explicitly refuses to deliver
832 * mail coming from this address, probably due
833 * to an anti-spam domain exclusion. Respect
834 * this. Don't try to ship the message, and
835 * don't prevent it from being deleted.
840 case 452: /* insufficient system storage */
842 * Temporary out-of-queue-space condition on the
843 * ESMTP server. Don't try to ship the message,
844 * and suppress deletion so it can be retried on
845 * a future retrieval cycle.
847 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
849 return(PS_TRANSIENT);
851 case 552: /* message exceeds fixed maximum message size */
853 * Permanent no-go condition on the
854 * ESMTP server. Don't try to ship the message,
855 * and allow it to be deleted.
857 SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */
861 default: /* retry with invoking user's address */
862 if (SMTP_from(ctl->smtp_socket, user, options) != SM_OK)
864 error(0, -1, "SMTP error: %s", smtp_response);
866 return(PS_SMTP); /* should never happen */
872 * Now list the recipient addressees
874 * RFC 1123 requires that the domain name part of the
875 * RCPT TO address be "canonicalized", that is a FQDN
876 * or MX but not a CNAME. RFC1123 doesn't say whether
877 * the FQDN part can be null (as it frequently will be
878 * here), but it's hard to see how this could cause a
881 for (idp = xmit_names; idp; idp = idp->next)
882 if (idp->val.num == XMIT_ACCEPT)
883 if (SMTP_rcpt(ctl->smtp_socket, idp->id) == SM_OK)
888 idp->val.num = XMIT_ANTISPAM;
890 "SMTP listener doesn't like recipient address `%s'", idp->id);
892 if (!good_addresses && SMTP_rcpt(ctl->smtp_socket, user) != SM_OK)
895 "can't even send to calling user!");
900 /* tell it we're ready to send data */
901 SMTP_data(ctl->smtp_socket);
904 /* we may need to strip carriage returns */
909 for (sp = tp = headers; *sp; sp++)
916 /* write all the headers */
918 if (ctl->mda && sinkfp)
919 n = fwrite(headers, 1, strlen(headers), sinkfp);
920 else if (ctl->smtp_socket != -1)
921 n = SockWrite(ctl->smtp_socket, headers, strlen(headers));
926 error(0, errno, "writing RFC822 headers");
930 signal(SIGCHLD, sigchld);
934 else if (outlevel == O_VERBOSE)
937 /* write error notifications */
938 #ifdef HAVE_RES_SEARCH
939 if (no_local_matches || has_nuls || bad_addresses)
941 if (has_nuls || bad_addresses)
942 #endif /* HAVE_RES_SEARCH */
945 char errhd[USERNAMELEN + POPBUFSIZE], *errmsg;
948 (void) strcpy(errhd, "X-Fetchmail-Warning: ");
949 #ifdef HAVE_RES_SEARCH
950 if (no_local_matches)
952 if (reject_count != 1)
953 strcat(errhd, "no recipient addresses matched declared local names");
956 for (idp = xmit_names; idp; idp = idp->next)
957 if (idp->val.num == XMIT_REJECT)
959 sprintf(errhd+strlen(errhd), "recipient address %s didn't match any local name", idp->id);
962 #endif /* HAVE_RES_SEARCH */
966 if (errhd[sizeof("X-Fetchmail-Warning: ")])
968 strcat(errhd, "message has embedded NULs");
973 if (errhd[sizeof("X-Fetchmail-Warning: ")])
975 strcat(errhd, "SMTP listener rejected local recipient addresses: ");
976 errlen = strlen(errhd);
977 for (idp = xmit_names; idp; idp = idp->next)
978 if (idp->val.num == XMIT_ANTISPAM)
979 errlen += strlen(idp->id) + 2;
981 errmsg = alloca(errlen+3);
982 (void) strcpy(errmsg, errhd);
983 for (idp = xmit_names; idp; idp = idp->next)
984 if (idp->val.num == XMIT_ANTISPAM)
986 strcat(errmsg, idp->id);
988 strcat(errmsg, ", ");
993 if (ctl->mda && !ctl->forcecr)
994 strcat(errmsg, "\n");
996 strcat(errmsg, "\r\n");
998 /* we may need to strip carriage returns */
1003 for (sp = tp = errmsg; *sp; sp++)
1009 /* ship out the error line */
1013 fwrite(errmsg, sizeof(char), strlen(errmsg), sinkfp);
1015 SockWrite(ctl->smtp_socket, errmsg, strlen(errmsg));
1019 free_str_list(&xmit_names);
1021 /* issue the delimiter line */
1022 if (sinkfp && ctl->mda)
1023 fputc('\n', sinkfp);
1024 else if (ctl->smtp_socket != -1)
1027 SockWrite(ctl->smtp_socket, "\n", 1);
1029 SockWrite(ctl->smtp_socket, "\r\n", 2);
1035 static int readbody(sock, ctl, forward, len, delimited)
1036 /* read and dispose of a message body presented on sock */
1037 struct query *ctl; /* query control record */
1038 int sock; /* to which the server is connected */
1039 int len; /* length of message */
1040 bool forward; /* TRUE to forward */
1041 bool delimited; /* does the protocol use a message delimiter? */
1044 char buf[MSGBUFSIZE+1], *cp;
1046 /* pass through the text lines */
1047 while (delimited || len > 0)
1049 if ((linelen = SockRead(sock, buf, sizeof(buf)-1)) == -1)
1051 set_timeout(ctl->server.timeout);
1053 /* write the message size dots */
1056 sizeticker += linelen;
1057 while (sizeticker >= SIZETICKER)
1059 if (outlevel > O_SILENT)
1061 sizeticker -= SIZETICKER;
1066 /* fix messages that have only \n line-termination (for qmail) */
1069 cp = buf + strlen(buf) - 1;
1070 if (*cp == '\n' && (cp == buf || cp[-1] != '\r'))
1078 /* check for end of message */
1079 if (delimited && *buf == '.')
1080 if (buf[1] == '\r' && buf[2] == '\n')
1083 /* ship out the text line */
1089 * SMTP byte-stuffing. We only do this if the protocol does *not*
1090 * use .<CR><LF> as EOM. If it does, the server will already have
1091 * decorated any . lines it sends back up.
1093 if (!delimited && *buf == '.')
1094 if (sinkfp && ctl->mda)
1096 else if (ctl->smtp_socket != -1)
1097 SockWrite(ctl->smtp_socket, buf, 1);
1099 /* we may need to strip carriage returns */
1104 for (sp = tp = buf; *sp; sp++)
1112 n = fwrite(buf, 1, strlen(buf), sinkfp);
1113 else if (ctl->smtp_socket != -1)
1114 n = SockWrite(ctl->smtp_socket, buf, strlen(buf));
1118 error(0, errno, "writing message text");
1122 signal(SIGCHLD, sigchld);
1126 else if (outlevel == O_VERBOSE)
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 */
1174 int ok, js, pst, sock = -1;
1175 char *msg, *cp, realname[HOSTLEN];
1179 if (ctl->server.preauthenticate == 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);
1226 if (ctl->smtp_socket != -1)
1227 close(ctl->smtp_socket);
1234 char buf [POPBUFSIZE+1], *sp;
1235 int *msgsizes, len, num, count, new, deletions = 0;
1239 /* execute pre-initialization command, if any */
1240 if (ctl->preconnect && (ok = system(ctl->preconnect)))
1242 sprintf(buf, "pre-connection command failed with status %d", ok);
1248 /* open a socket to the mail server */
1249 port = ctl->server.port ? ctl->server.port : protocol->port;
1250 if ((sock = SockOpen(ctl->server.names->id, port)) == -1)
1252 #ifndef EHOSTUNREACH
1253 #define EHOSTUNREACH (-1)
1255 if (outlevel == O_VERBOSE || errno != EHOSTUNREACH)
1256 error(0, errno, "connecting to host");
1262 if (ctl->server.preauthenticate == A_KERBEROS_V4)
1264 ok = kerberos_auth(sock, ctl->server.canonical_name);
1267 set_timeout(ctl->server.timeout);
1269 #endif /* KERBEROS_V4 */
1271 /* accept greeting message from mail server */
1272 ok = (protocol->parse_response)(sock, buf);
1275 set_timeout(ctl->server.timeout);
1278 * Try to parse the host's actual name out of the greeting
1279 * message. We do this so that the progress messages will
1280 * make sense even if the connection is indirected through
1281 * ssh. *Do* use this for hacking reply headers, but *don't*
1282 * use it for error logging, as the names in the log should
1283 * correlate directly back to rc file entries.
1285 * This assumes that the first space-delimited token found
1286 * that contains at least two dots (with the characters on
1287 * each side of the dot alphanumeric to exclude version
1288 * numbers) is the hostname. The hostname candidate may not
1289 * contain @ -- if it does it's probably a mailserver
1290 * maintainer's name. If no such token is found, fall back on
1291 * the .fetchmailrc id.
1294 sp = (char *)NULL; /* sacrifice to -Wall */
1295 for (cp = buf; *cp; cp++)
1299 case 0: /* skip to end of current token */
1304 case 1: /* look for blank-delimited token */
1312 case 2: /* look for first dot */
1315 else if (*cp == ' ')
1317 else if (*cp == '.' && isalpha(cp[1]) && isalpha(cp[-1]))
1321 case 3: /* look for second dot */
1324 else if (*cp == ' ')
1326 else if (*cp == '.' && isalpha(cp[1]) && isalpha(cp[-1]))
1330 case 4: /* look for trailing space */
1333 else if (*cp == ' ')
1344 char *tp = realname;
1351 strcpy(realname, ctl->server.names->id);
1353 /* try to get authorized to fetch mail */
1354 if (protocol->getauth)
1356 shroud = ctl->password;
1357 ok = (protocol->getauth)(sock, ctl, buf);
1358 shroud = (char *)NULL;
1363 error(0, -1, "Authorization failure on %s@%s",
1368 set_timeout(ctl->server.timeout);
1371 ctl->errcount = fetches = 0;
1373 /* now iterate over each folder selected */
1374 for (idp = ctl->mailboxes; idp; idp = idp->next)
1376 if (outlevel >= O_VERBOSE)
1378 error(0, 0, "selecting folder %s");
1380 error(0, 0, "selecting default folder");
1382 /* compute number of messages and number of new messages waiting */
1383 ok = (protocol->getrange)(sock, ctl, idp->id, &count, &new);
1386 set_timeout(ctl->server.timeout);
1388 /* show user how many messages we downloaded */
1390 (void) sprintf(buf, "%s@%s:%s",
1391 ctl->remotename, realname, idp->id);
1393 (void) sprintf(buf, "%s@%s", ctl->remotename, realname);
1394 if (outlevel > O_SILENT)
1395 if (count == -1) /* only used for ETRN */
1396 error(0, 0, "Polling %s", buf);
1397 else if (count == 0)
1398 error(0, 0, "No mail at %s", buf);
1401 if (new != -1 && (count - new) > 0)
1402 error(0, 0, "%d message%s (%d seen) at %s.",
1403 count, count > 1 ? "s" : "", count-new, buf);
1405 error(0, 0, "%d message%s at %s.",
1406 count, count > 1 ? "s" : "", buf);
1411 if (new == -1 || ctl->fetchall)
1413 ok = ((new > 0) ? PS_SUCCESS : PS_NOMAIL);
1418 bool force_retrieval;
1421 * What forces this code is that in POP3 and IMAP2BIS you can't
1422 * fetch a message without having it marked `seen'. In IMAP4,
1423 * on the other hand, you can (peek_capable is set to convey
1426 * The result of being unable to peek is that if there's
1427 * any kind of transient error (DNS lookup failure, or
1428 * sendmail refusing delivery due to process-table limits)
1429 * the message will be marked "seen" on the server without
1430 * having been delivered. This is not a big problem if
1431 * fetchmail is running in foreground, because the user
1432 * will see a "skipped" message when it next runs and get
1435 * But in daemon mode this leads to the message being silently
1436 * ignored forever. This is not acceptable.
1438 * We compensate for this by checking the error count from the
1439 * previous pass and forcing all messages to be considered new
1442 force_retrieval = !peek_capable && (ctl->errcount > 0);
1445 * We may need to get sizes in order to check message
1446 * limits. Or it may be forced because the fetch methods
1447 * don't return reliable sizes.
1449 msgsizes = (int *)NULL;
1450 if (proto->getsizes && (proto->force_getsizes || ctl->limit > 0))
1452 msgsizes = (int *)alloca(sizeof(int) * count);
1454 ok = (proto->getsizes)(sock, count, msgsizes);
1457 set_timeout(ctl->server.timeout);
1460 /* read, forward, and delete messages */
1461 for (num = 1; num <= count; num++)
1463 bool toolarge = (ctl->limit > 0)
1464 && msgsizes && (msgsizes[num-1] > ctl->limit);
1465 bool fetch_it = !toolarge
1466 && (ctl->fetchall || force_retrieval || !(protocol->is_old && (protocol->is_old)(sock,ctl,num)));
1467 bool suppress_delete = FALSE;
1468 bool suppress_forward = FALSE;
1470 /* we may want to reject this message if it's old */
1473 if (outlevel > O_SILENT)
1475 error_build("skipping message %d", num);
1477 error_build(" (oversized, %d bytes)", msgsizes[num-1]);
1482 /* request a message */
1483 ok = (protocol->fetch_headers)(sock, ctl, num, &len);
1486 set_timeout(ctl->server.timeout);
1488 if (outlevel > O_SILENT)
1490 bool wholesize = !protocol->fetch_body;
1492 error_build("reading message %d", num);
1494 /* -1 means we didn't see a size in the response */
1495 if (len == -1 && msgsizes)
1497 len = msgsizes[num - 1];
1502 error_build(" (%d %sbytes)",
1503 len, wholesize ? "" : "header ");
1504 if (outlevel == O_VERBOSE)
1505 error_complete(0, 0, "");
1511 * Read the message headers and ship them to the
1514 ok = readheaders(sock, len, ctl, realname);
1515 if (ok == PS_TRANSIENT)
1516 suppress_delete = TRUE;
1517 else if (ok == PS_REFUSED)
1518 suppress_forward = TRUE;
1521 set_timeout(ctl->server.timeout);
1524 * If we're using IMAP4 or something else that
1525 * can fetch headers separately from bodies,
1526 * it's time to request the body now. This
1527 * fetch may be skipped if we got an anti-spam
1528 * or other PS_REFUSED error response during
1531 if (protocol->fetch_body)
1533 if ((ok = (protocol->trail)(sock, ctl, num)))
1535 set_timeout(ctl->server.timeout);
1537 if (!suppress_forward)
1539 if ((ok=(protocol->fetch_body)(sock,ctl,num,&len)))
1541 if (outlevel > O_SILENT && !msgsizes)
1542 error_build(" (%d body bytes) ", len);
1543 set_timeout(ctl->server.timeout);
1547 /* process the body now */
1554 protocol->delimited);
1555 if (ok == PS_TRANSIENT)
1556 suppress_delete = TRUE;
1559 set_timeout(ctl->server.timeout);
1561 /* tell server we got it OK and resynchronize */
1562 if (protocol->trail)
1564 ok = (protocol->trail)(sock, ctl, num);
1567 set_timeout(ctl->server.timeout);
1571 /* end-of-message processing starts here */
1572 if (outlevel == O_VERBOSE)
1573 fputc('\n', stderr);
1579 /* close the delivery pipe, we'll reopen before next message */
1580 rc = pclose(sinkfp);
1581 signal(SIGCHLD, sigchld);
1584 error(0, -1, "MDA exited abnormally or returned nonzero status");
1588 else if (!suppress_forward)
1590 /* write message terminator */
1591 if (SMTP_eom(ctl->smtp_socket) != SM_OK)
1593 error(0, -1, "SMTP listener refused delivery");
1595 suppress_delete = TRUE;
1603 * At this point in flow of control, either we've bombed
1604 * on a protocol error or had delivery refused by the SMTP
1605 * server (unlikely -- I've never seen it) or we've seen
1606 * `accepted for delivery' and the message is shipped.
1607 * It's safe to mark the message seen and delete it on the
1611 /* maybe we delete this message now? */
1612 if (protocol->delete
1614 && (fetch_it ? !ctl->keep : ctl->flush))
1617 if (outlevel > O_SILENT)
1618 error_complete(0, 0, " flushed");
1619 ok = (protocol->delete)(sock, ctl, num);
1622 set_timeout(ctl->server.timeout);
1623 delete_str(&ctl->newsaved, num);
1625 else if (outlevel > O_SILENT)
1626 error_complete(0, 0, " not flushed");
1628 /* perhaps this as many as we're ready to handle */
1629 if (ctl->fetchlimit > 0 && ctl->fetchlimit <= fetches)
1636 set_timeout(ctl->server.timeout);
1637 ok = gen_transact(sock, protocol->exit_cmd);
1639 ok = (fetches > 0) ? PS_SUCCESS : PS_NOMAIL;
1645 set_timeout(ctl->server.timeout);
1646 if (ok != 0 && ok != PS_SOCKET)
1647 gen_transact(sock, protocol->exit_cmd);
1652 msg = (char *)NULL; /* sacrifice to -Wall */
1659 msg = "authorization";
1662 msg = "missing or bad RFC822 header";
1668 msg = "client/server synchronization";
1671 msg = "client/server protocol";
1674 msg = "SMTP transaction";
1677 error(0, 0, "undefined");
1680 if (ok==PS_SOCKET || ok==PS_AUTHFAIL || ok==PS_SYNTAX || ok==PS_IOERR
1681 || ok==PS_ERROR || ok==PS_PROTOCOL || ok==PS_SMTP)
1682 error(0, -1, "%s error while fetching from %s", msg, ctl->server.names->id);
1685 signal(SIGALRM, sigsave);
1689 #if defined(HAVE_STDARG_H)
1690 void gen_send(int sock, char *fmt, ... )
1691 /* assemble command in printf(3) style and send to the server */
1693 void gen_send(sock, fmt, va_alist)
1694 /* assemble command in printf(3) style and send to the server */
1695 int sock; /* socket to which server is connected */
1696 const char *fmt; /* printf-style format */
1700 char buf [POPBUFSIZE+1];
1703 if (protocol->tagged)
1704 (void) sprintf(buf, "%s ", GENSYM);
1708 #if defined(HAVE_STDARG_H)
1713 vsprintf(buf + strlen(buf), fmt, ap);
1716 strcat(buf, "\r\n");
1717 SockWrite(sock, buf, strlen(buf));
1719 if (outlevel == O_VERBOSE)
1723 if (shroud && shroud[0] && (cp = strstr(buf, shroud)))
1727 sp = cp + strlen(shroud);
1733 buf[strlen(buf)-2] = '\0';
1734 error(0, 0, "%s> %s", protocol->name, buf);
1738 int gen_recv(sock, buf, size)
1739 /* get one line of input from the server */
1740 int sock; /* socket to which server is connected */
1741 char *buf; /* buffer to receive input */
1742 int size; /* length of buffer */
1744 if (SockRead(sock, buf, size) == -1)
1748 if (buf[strlen(buf)-1] == '\n')
1749 buf[strlen(buf)-1] = '\0';
1750 if (buf[strlen(buf)-1] == '\r')
1751 buf[strlen(buf)-1] = '\r';
1752 if (outlevel == O_VERBOSE)
1753 error(0, 0, "%s< %s", protocol->name, buf);
1758 #if defined(HAVE_STDARG_H)
1759 int gen_transact(int sock, char *fmt, ... )
1760 /* assemble command in printf(3) style, send to server, accept a response */
1762 int gen_transact(int sock, fmt, va_alist)
1763 /* assemble command in printf(3) style, send to server, accept a response */
1764 int sock; /* socket to which server is connected */
1765 const char *fmt; /* printf-style format */
1770 char buf [POPBUFSIZE+1];
1773 if (protocol->tagged)
1774 (void) sprintf(buf, "%s ", GENSYM);
1778 #if defined(HAVE_STDARG_H)
1783 vsprintf(buf + strlen(buf), fmt, ap);
1786 strcat(buf, "\r\n");
1787 SockWrite(sock, buf, strlen(buf));
1789 if (outlevel == O_VERBOSE)
1793 if (shroud && shroud[0] && (cp = strstr(buf, shroud)))
1797 sp = cp + strlen(shroud);
1803 buf[strlen(buf)-1] = '\0';
1804 error(0, 0, "%s> %s", protocol->name, buf);
1807 /* we presume this does its own response echoing */
1808 ok = (protocol->parse_response)(sock, buf);
1809 set_timeout(mytimeout);
1814 /* driver.c ends here */