2 * transact.c -- transaction primitives for the fetchmail driver loop
4 * Copyright 2001 by Eric S. Raymond
5 * For license terms, see the file COPYING in this directory.
14 #endif /* HAVE_MEMORY_H */
15 #if defined(STDC_HEADERS)
18 #if defined(HAVE_UNISTD_H)
21 #if defined(HAVE_STDARG_H)
29 #ifdef HAVE_NET_SOCKET_H
30 #include <net/socket.h>
32 #include <sys/socket.h>
38 #include "fetchmail.h"
40 #define _FIX_INT_MIN(x) ((x) < INT_MIN ? INT_MIN : (x))
41 #define _FIX_INT_MAX(x) ((x) > INT_MAX ? INT_MAX : (x))
42 #define CAST_TO_INT(x) ((int)(_FIX_INT_MIN(_FIX_INT_MAX(x))))
43 #define UCAST_TO_INT(x) ((int)(_FIX_INT_MAX(x)))
45 /* global variables: please reinitialize them explicitly for proper
46 * working in daemon mode */
48 /* session variables initialized in init_transact() */
49 int suppress_tags = FALSE; /* emit tags? */
52 #define GENSYM (sprintf(tag, "A%04d", ++tagnum % TAGMOD), tag)
53 static const struct method *protocol;
54 char shroud[PASSWORDLEN*2+3]; /* string to shroud in debug output */
56 /* session variables initialized in do_session() */
57 int mytimeout; /* value of nonreponse timeout */
59 /* mail variables initialized in readheaders() */
61 static int accept_count, reject_count;
63 /** add given address to xmit_names if it exactly matches a full address
64 * \returns nonzero if matched */
65 static int map_address(const char *addr, struct query *ctl, struct idlist **xmit_names)
69 lname = idpair_find(&ctl->localnames, addr);
71 if (outlevel >= O_DEBUG)
72 report(stdout, GT_("mapped address %s to local %s\n"), addr, lname);
73 save_str(xmit_names, lname, XMIT_ACCEPT);
79 /** add given name to xmit_names if it matches declared localnames */
80 static void map_name(const char *name, struct query *ctl, struct idlist **xmit_names)
81 /* name: name to map */
82 /* ctl: list of permissible aliases */
83 /* xmit_names: list of recipient names parsed out */
87 lname = idpair_find(&ctl->localnames, name);
88 if (!lname && ctl->wildcard)
91 if (lname != (char *)NULL)
93 if (outlevel >= O_DEBUG)
94 report(stdout, GT_("mapped %s to local %s\n"), name, lname);
95 save_str(xmit_names, lname, XMIT_ACCEPT);
100 static void find_server_names(const char *hdr,
102 struct idlist **xmit_names)
103 /* parse names out of a RFC822 header into an ID list */
104 /* hdr: RFC822 header in question */
105 /* ctl: list of permissible aliases */
106 /* xmit_names: list of recipient names parsed out */
108 if (hdr == (char *)NULL)
114 for (cp = nxtaddr(hdr); cp != NULL; cp = nxtaddr(NULL))
119 * Handle empty address from a To: header containing only
126 * If the name of the user begins with a qmail virtual
127 * domain prefix, ignore the prefix. Doing this here
128 * means qvirtual will work either with ordinary name
129 * mapping or with a localdomains option.
131 if (ctl->server.qvirtual)
133 int sl = strlen(ctl->server.qvirtual);
135 if (!strncasecmp((char *)cp, ctl->server.qvirtual, sl))
139 if ((atsign = strchr((char *)cp, '@'))) {
142 /* try to match full address first, this takes
143 * precedence over localdomains and alias mappings */
144 if (map_address(cp, ctl, xmit_names))
148 * Does a trailing segment of the hostname match something
149 * on the localdomains list? If so, save the whole name
152 for (idp = ctl->server.localdomains; idp; idp = idp->next) {
155 rhs = atsign + (strlen(atsign) - strlen(idp->id));
157 (rhs[-1] == '.' || rhs[-1] == '@') &&
158 strcasecmp(rhs, idp->id) == 0)
160 if (outlevel >= O_DEBUG)
161 report(stdout, GT_("passed through %s matching %s\n"),
163 save_str(xmit_names, (const char *)cp, XMIT_ACCEPT);
169 /* if we matched a local domain, idp != NULL */
173 * Check to see if the right-hand part is an alias
174 * or MX equivalent of the mailserver. If it's
175 * not, skip this name. If it is, we'll keep
176 * going and try to find a mapping to a client name.
178 if (!is_host_alias(atsign+1, ctl, &ai0))
180 save_str(xmit_names, cp, XMIT_REJECT);
186 map_name(cp, ctl, xmit_names);
194 * Return zero on a syntactically invalid address, nz on a valid one.
196 * This used to be strchr(a, '.'), but it turns out that lines like this
198 * Received: from punt-1.mail.demon.net by mailstore for markb@ordern.com
199 * id 938765929:10:27223:2; Fri, 01 Oct 99 08:18:49 GMT
201 * are not uncommon. So now we just check that the following token is
202 * not itself an email address.
204 #define VALID_ADDRESS(a) !strchr(a, '@')
206 static char *parse_received(struct query *ctl, char *bufp)
207 /* try to extract real address from the Received line */
208 /* If a valid Received: line is found, we return the full address in
209 * a buffer which can be parsed from nxtaddr(). This is to ansure that
210 * the local domain part of the address can be passed along in
211 * find_server_names() if it contains one.
212 * Note: We should return a dummy header containing the address
213 * which makes nxtaddr() behave correctly.
216 char *base, *ok = (char *)NULL;
217 static char rbuf[HOSTLEN + USERNAMELEN + 4];
218 struct addrinfo *ai0;
220 #define RBUF_WRITE(value) if (tp < rbuf+sizeof(rbuf)-1) *tp++=value
223 * Try to extract the real envelope addressee. We look here
224 * specifically for the mailserver's Received line.
225 * Note: this will only work for sendmail, or an MTA that
226 * shares sendmail's convention for embedding the envelope
227 * address in the Received line. Sendmail itself only
228 * does this when the mail has a single recipient.
230 if (outlevel >= O_DEBUG)
231 report(stdout, GT_("analyzing Received line:\n%s"), bufp);
233 /* search for whitepace-surrounded "by" followed by valid address */
234 for (base = bufp; ; base = ok + 2)
236 if (!(ok = strstr(base, "by")))
238 else if (!isspace((unsigned char)ok[-1]) || !isspace((unsigned char)ok[2]))
244 /* extract space-delimited token after "by" */
245 for (sp = ok + 2; isspace((unsigned char)*sp); sp++)
248 for (; *sp && !isspace((unsigned char)*sp); sp++)
252 /* look for valid address */
253 if (VALID_ADDRESS(rbuf))
256 ok = sp - 1; /* arrange to skip this token */
262 * If it's a DNS name of the mail server, look for the
263 * recipient name after a following "for". Otherwise
266 if (is_host_alias(rbuf, ctl, &ai0))
268 if (outlevel >= O_DEBUG)
270 GT_("line accepted, %s is an alias of the mailserver\n"), rbuf);
274 if (outlevel >= O_DEBUG)
276 GT_("line rejected, %s is not an alias of the mailserver\n"),
281 /* search for whitepace-surrounded "for" followed by xxxx@yyyy */
282 for (base = ok + 4 + strlen(rbuf); ; base = ok + 2)
284 if (!(ok = strstr(base, "for")))
286 else if (!isspace((unsigned char)ok[-1]) || !isspace((unsigned char)ok[3]))
292 /* extract space-delimited token after "for" */
293 for (sp = ok + 3; isspace((unsigned char)*sp); sp++)
296 for (; !isspace((unsigned char)*sp); sp++)
300 if (strchr(rbuf, '@'))
303 ok = sp - 1; /* arrange to skip this token */
308 flag want_gt = FALSE;
311 /* char after "for" could be space or a continuation newline */
312 for (sp = ok + 4; isspace((unsigned char)*sp); sp++)
315 RBUF_WRITE(':'); /* Here is the hack. This is to be friends */
316 RBUF_WRITE(' '); /* with nxtaddr()... */
322 while (*sp == '@') /* skip routes */
323 while (*sp && *sp++ != ':')
326 && (want_gt ? (*sp != '>') : !isspace((unsigned char)*sp))
328 if (!isspace((unsigned char)*sp))
335 /* uh oh -- whitespace here can't be right! */
341 if (strlen(rbuf) <= 3) /* apparently nothing has been found */
349 if (outlevel >= O_DEBUG)
350 report(stdout, GT_("no Received address found\n"));
355 if (outlevel >= O_DEBUG) {
356 char *lf = rbuf + strlen(rbuf)-1;
358 if (outlevel >= O_DEBUG)
359 report(stdout, GT_("found Received address `%s'\n"), rbuf+2);
366 /* shared by readheaders and readbody */
367 static int sizeticker;
369 /** Print ticker based on a amount of data transferred of \a bytes.
370 * Increments \a *tickervar by \a bytes, and if it exceeds
371 * \a SIZETICKER, print a dot and reduce *tickervar by \a SIZETICKER. */
372 static void print_ticker(int *tickervar, int bytes)
375 while (*tickervar >= SIZETICKER)
382 *tickervar -= SIZETICKER;
386 #define EMPTYLINE(s) (((s)[0] == '\r' && (s)[1] == '\n' && (s)[2] == '\0') \
387 || ((s)[0] == '\n' && (s)[1] == '\0'))
389 static int end_of_header (const char *s)
390 /* accept "\r*\n" as EOH in order to be bulletproof against broken survers */
394 return (s[0] == '\n' && s[1] == '\0');
397 int readheaders(int sock,
402 flag *suppress_readbody)
403 /* read message headers and ship to SMTP or MDA */
404 /* sock: to which the server is connected */
405 /* fetchlen: length of message according to fetch response */
406 /* reallen: length of message according to getsizes */
407 /* ctl: query control record */
408 /* num: index of message */
409 /* suppress_readbody: whether call to readbody() should be supressed */
414 struct addrblk *next;
416 struct addrblk *to_addrchain = NULL;
417 struct addrblk **to_chainptr = &to_addrchain;
418 struct addrblk *resent_to_addrchain = NULL;
419 struct addrblk **resent_to_chainptr = &resent_to_addrchain;
421 char buf[MSGBUFSIZE+1];
422 int from_offs, reply_to_offs, resent_from_offs;
423 int app_from_offs, sender_offs, resent_sender_offs;
425 char *received_for, *rcv, *cp;
426 static char *delivered_to = NULL;
427 int n, oldlen, ch, remaining, skipcount;
429 int delivered_to_count;
431 flag no_local_matches = FALSE;
433 int olderrs, good_addresses, bad_addresses;
434 int retain_mail = 0, refuse_mail = 0;
435 flag already_has_return_path = FALSE;
439 msgblk.return_path[0] = '\0';
440 olderrs = ctl->errcount;
442 /* read message headers */
443 msgblk.reallen = reallen;
446 * We used to free the header block unconditionally at the end of
447 * readheaders, but it turns out that if close_sink() hits an error
448 * condition the code for sending bouncemail will actually look
449 * at the freed storage and coredump...
451 xfree(msgblk.headers);
452 free_str_list(&msgblk.recipients);
455 /* initially, no message digest */
456 memset(ctl->digest, '\0', sizeof(ctl->digest));
459 from_offs = reply_to_offs = resent_from_offs = app_from_offs =
460 sender_offs = resent_sender_offs = env_offs = -1;
464 delivered_to_count = 0;
467 for (remaining = fetchlen; remaining > 0 || protocol->delimited; )
471 line = (char *)xmalloc(sizeof(buf));
478 set_timeout(mytimeout);
479 if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1) {
487 * Smash out any NULs, they could wreak havoc later on.
488 * Some network stacks seem to generate these at random,
489 * especially (according to reports) at the beginning of the
490 * first read. NULs are illegal in RFC822 format.
492 for (sp = tp = buf; sp < buf + n; sp++)
505 * Try to gracefully handle the case where the length of a
506 * line exceeds MSGBUFSIZE.
508 if (n && buf[n-1] != '\n')
510 rline = (char *) realloc(line, linelen + 1);
517 memcpy(line + linelen - n, buf, n);
518 line[linelen] = '\0';
519 ch = ' '; /* So the next iteration starts */
523 /* lines may not be properly CRLF terminated; fix this for qmail */
524 /* we don't want to overflow the buffer here */
525 if (ctl->forcecr && buf[n-1]=='\n' && (n==1 || buf[n-2]!='\r'))
528 rline = (char *) realloc(line, linelen + 2);
535 memcpy(line + linelen - n, buf, n - 1);
536 tcp = line + linelen - 1;
540 /* n++; - not used later on */
545 rline = (char *) realloc(line, linelen + 1);
552 memcpy(line + linelen - n, buf, n + 1);
555 /* check for end of headers */
556 if (end_of_header(line))
559 if (linelen != strlen (line))
562 goto process_headers;
566 * Check for end of message immediately. If one of your folders
567 * has been mangled, the delimiter may occur directly after the
570 if (protocol->delimited && line[0] == '.' && EMPTYLINE(line+1))
572 if (suppress_readbody)
573 *suppress_readbody = TRUE;
574 goto eoh; /* above */
578 * At least one brain-dead website (netmind.com) is known to
579 * send out robotmail that's missing the RFC822 delimiter blank
580 * line before the body! Without this check fetchmail segfaults.
581 * With it, we treat such messages as spam and refuse them.
583 * Frederic Marchal reported in February 2006 that hotmail
584 * or something improperly wrapped a very long TO header
585 * (wrapped without inserting whitespace in the continuation
586 * line) and found that this code thus refused a message
587 * that should have been delivered.
589 * XXX FIXME: we should probably wrap the message up as
590 * message/rfc822 attachment and forward to postmaster (Rob
594 && !ctl->server.badheader == BHACCEPT
595 && !isspace((unsigned char)line[0])
596 && !strchr(line, ':'))
598 if (linelen != strlen (line))
600 if (outlevel > O_SILENT)
602 GT_("incorrect header line found - see manpage for bad-header option\n"));
603 if (outlevel >= O_VERBOSE)
604 report (stdout, GT_("line: %s"), line);
608 /* check for RFC822 continuations */
609 set_timeout(mytimeout);
613 (ch == ' ' || ch == '\t'); /* continuation to next line? */
615 /* write the message size dots */
616 if ((outlevel > O_SILENT && outlevel < O_VERBOSE) && linelen > 0)
618 print_ticker(&sizeticker, linelen);
622 * Decode MIME encoded headers. We MUST do this before
623 * looking at the Content-Type / Content-Transfer-Encoding
624 * headers (RFC 2046).
626 if ( ctl->mimedecode )
630 /* the line is now shorter. So we retrace back till we find
631 * our terminating combination \n\0, we move backwards to
632 * make sure that we don't catch some \n\0 stored in the
633 * decoded part of the message */
634 for (tcp = line + linelen - 1; tcp > line && (*tcp != 0 || tcp[-1] != '\n'); tcp--) { }
635 if (tcp > line) linelen = tcp - line;
639 /* skip processing if we are going to retain or refuse this mail */
640 if (retain_mail || refuse_mail)
646 /* we see an ordinary (non-header, non-message-delimiter) line */
647 if (linelen != strlen (line))
651 * The University of Washington IMAP server (the reference
652 * implementation of IMAP4 written by Mark Crispin) relies
653 * on being able to keep base-UID information in a special
654 * message at the head of the mailbox. This message should
655 * neither be deleted nor forwarded.
657 * An example for such a message is (keep this in so people
658 * find it when looking where the special code is to handle the
661 * From MAILER-DAEMON Wed Nov 23 11:38:42 2005
662 * Date: 23 Nov 2005 11:38:42 +0100
663 * From: Mail System Internal Data <MAILER-DAEMON@mail.example.org>
664 * Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA
665 * Message-ID: <1132742322@mail.example.org>
666 * X-IMAP: 1132742306 0000000001
669 * This text is part of the internal format of your mail folder, and is not
670 * a real message. It is created automatically by the mail system software.
671 * If deleted, important folder data will be lost, and it will be re-created
672 * with the data reset to initial values.
674 * This message is only visible if a POP3 server that is unaware
675 * of these UWIMAP messages is used besides UWIMAP or PINE.
677 * We will just check if the first message in the mailbox has an
682 * We disable this check under POP2 because there's no way to
683 * prevent deletion of the message. So at least we ought to
684 * forward it to the user so he or she will have some clue
685 * that things have gone awry.
687 if (servport("pop2") != servport(protocol->service))
688 #endif /* POP2_ENABLE */
689 if (num == 1 && !strncasecmp(line, "X-IMAP:", 7)) {
696 * This code prevents fetchmail from becoming an accessory after
697 * the fact to upstream sendmails with the `E' option on. It also
698 * copes with certain brain-dead POP servers (like NT's) that pass
699 * through Unix from_ lines.
701 * Either of these bugs can result in a non-RFC822 line at the
702 * beginning of the headers. If fetchmail just passes it
703 * through, the client listener may think the message has *no*
704 * headers (since the first) line it sees doesn't look
705 * RFC822-conformant) and fake up a set.
707 * What the user would see in this case is bogus (synthesized)
708 * headers, followed by a blank line, followed by the >From,
709 * followed by the real headers, followed by a blank line,
712 * We forestall this lossage by tossing anything that looks
713 * like an escaped or passed-through From_ line in headers.
714 * These aren't RFC822 so our conscience is clear...
716 if (!strncasecmp(line, ">From ", 6) || !strncasecmp(line, "From ", 5))
723 * We remove all Delivered-To: headers if dropdelivered is set
724 * - special care must be taken if Delivered-To: is also used
725 * as envelope at the same time.
727 * This is to avoid false mail loops errors when delivering
728 * local messages to and from a Postfix or qmail mailserver.
730 if (ctl->dropdelivered && !strncasecmp(line, "Delivered-To:", 13))
733 ctl->server.envelope == STRING_DISABLED ||
734 !ctl->server.envelope ||
735 strcasecmp(ctl->server.envelope, "Delivered-To") ||
736 delivered_to_count != ctl->server.envskip)
740 delivered_to_count++;
745 * If we see a Status line, it may have been inserted by an MUA
746 * on the mail host, or it may have been inserted by the server
747 * program after the headers in the transaction stream. This
748 * can actually hose some new-mail notifiers such as xbuffy,
749 * which assumes any Status line came from a *local* MDA and
750 * therefore indicates that the message has been seen.
752 * Some buggy POP servers (including at least the 3.3(20)
753 * version of the one distributed with IMAP) insert empty
754 * Status lines in the transaction stream; we'll chuck those
755 * unconditionally. Nonempty ones get chucked if the user
756 * turns on the dropstatus flag.
761 if (!strncasecmp(line, "Status:", 7))
763 else if (!strncasecmp(line, "X-Mozilla-Status:", 17))
768 while (*tcp && isspace((unsigned char)*tcp)) tcp++;
769 if (!*tcp || ctl->dropstatus)
778 line = reply_hack(line, ctl->server.truename, &linelen);
781 * OK, this is messy. If we're forwarding by SMTP, it's the
782 * SMTP-receiver's job (according to RFC821, page 22, section
783 * 4.1.1) to generate a Return-Path line on final delivery.
784 * The trouble is, we've already got one because the
785 * mailserver's SMTP thought *it* was responsible for final
788 * Stash away the contents of Return-Path (as modified by reply_hack)
789 * for use in generating MAIL FROM later on, then prevent the header
790 * from being saved with the others. In effect, we strip it off here.
792 * If the SMTP server conforms to the standards, and fetchmail gets the
793 * envelope sender from the Return-Path, the new Return-Path should be
794 * exactly the same as the original one.
796 * We do *not* want to ignore empty Return-Path headers. These should
797 * be passed through as a way of indicating that a message should
798 * not trigger bounces if delivery fails. What we *do* need to do is
799 * make sure we never try to rewrite such a blank Return-Path. We
800 * handle this with a check for <> in the rewrite logic above.
802 * Also, if an email has multiple Return-Path: headers, we only
803 * read the first occurance, as some spam email has more than one
807 if ((already_has_return_path==FALSE) && !strncasecmp("Return-Path:", line, 12) && (cp = nxtaddr(line)))
809 char nulladdr[] = "<>";
810 already_has_return_path = TRUE;
811 if (cp[0]=='\0') /* nxtaddr() strips the brackets... */
813 strncpy(msgblk.return_path, cp, sizeof(msgblk.return_path));
814 msgblk.return_path[sizeof(msgblk.return_path)-1] = '\0';
824 msgblk.headers = (char *)xmalloc(oldlen + 1);
825 (void) memcpy(msgblk.headers, line, linelen);
826 msgblk.headers[oldlen] = '\0';
828 line = msgblk.headers;
835 newlen = oldlen + linelen;
836 newhdrs = (char *) realloc(msgblk.headers, newlen + 1);
837 if (newhdrs == NULL) {
841 msgblk.headers = newhdrs;
842 memcpy(msgblk.headers + oldlen, line, linelen);
843 msgblk.headers[newlen] = '\0';
845 line = msgblk.headers + oldlen;
849 /* find offsets of various special headers */
850 if (!strncasecmp("From:", line, 5))
851 from_offs = (line - msgblk.headers);
852 else if (!strncasecmp("Reply-To:", line, 9))
853 reply_to_offs = (line - msgblk.headers);
854 else if (!strncasecmp("Resent-From:", line, 12))
855 resent_from_offs = (line - msgblk.headers);
856 else if (!strncasecmp("Apparently-From:", line, 16))
857 app_from_offs = (line - msgblk.headers);
859 * Netscape 4.7 puts "Sender: zap" in mail headers. Perverse...
861 * But a literal reading of RFC822 sec. 4.4.2 supports the idea
862 * that Sender: *doesn't* have to be a working email address.
864 * The definition of the Sender header in RFC822 says, in
865 * part, "The Sender mailbox specification includes a word
866 * sequence which must correspond to a specific agent (i.e., a
867 * human user or a computer program) rather than a standard
868 * address." That implies that the contents of the Sender
869 * field don't need to be a legal email address at all So
870 * ignore any Sender or Resent-Sender lines unless they
873 * (RFC2822 says the contents of Sender must be a valid mailbox
874 * address, which is also what RFC822 4.4.4 implies.)
876 else if (!strncasecmp("Sender:", line, 7) && (strchr(line, '@') || strchr(line, '!')))
877 sender_offs = (line - msgblk.headers);
878 else if (!strncasecmp("Resent-Sender:", line, 14) && (strchr(line, '@') || strchr(line, '!')))
879 resent_sender_offs = (line - msgblk.headers);
882 else if (!strncasecmp("Message-Id:", line, 11))
884 if (ctl->server.uidl)
888 line[IDLEN+12] = 0; /* prevent stack overflow */
889 sscanf(line+12, "%s", id);
890 if (!str_find( &ctl->newsaved, num))
892 struct idlist *newl = save_str(&ctl->newsaved,id,UID_SEEN);
893 newl->val.status.num = num;
897 #endif /* __UNUSED__ */
899 /* if multidrop is on, gather addressee headers */
902 if (!strncasecmp("To:", line, 3)
903 || !strncasecmp("Cc:", line, 3)
904 || !strncasecmp("Bcc:", line, 4)
905 || !strncasecmp("Apparently-To:", line, 14))
907 *to_chainptr = (struct addrblk *)xmalloc(sizeof(struct addrblk));
908 (*to_chainptr)->offset = (line - msgblk.headers);
909 to_chainptr = &(*to_chainptr)->next;
913 else if (!strncasecmp("Resent-To:", line, 10)
914 || !strncasecmp("Resent-Cc:", line, 10)
915 || !strncasecmp("Resent-Bcc:", line, 11))
917 *resent_to_chainptr = (struct addrblk *)xmalloc(sizeof(struct addrblk));
918 (*resent_to_chainptr)->offset = (line - msgblk.headers);
919 resent_to_chainptr = &(*resent_to_chainptr)->next;
920 *resent_to_chainptr = NULL;
923 else if (ctl->server.envelope != STRING_DISABLED)
925 if (ctl->server.envelope
926 && strcasecmp(ctl->server.envelope, "Received"))
928 if (env_offs == -1 && !strncasecmp(ctl->server.envelope,
930 strlen(ctl->server.envelope)))
932 if (skipcount++ < ctl->server.envskip)
934 env_offs = (line - msgblk.headers);
937 else if (!received_for && !strncasecmp("Received:", line, 9))
939 if (skipcount++ < ctl->server.envskip)
941 received_for = parse_received(ctl, line);
956 * This is the duplicate-message killer code.
958 * When mail delivered to a multidrop mailbox on the server is
959 * addressed to multiple people on the client machine, there will
960 * be one copy left in the box for each recipient. This is not a
961 * problem if we have the actual recipient address to dispatch on
962 * (e.g. because we've mined it out of sendmail trace headers, or
963 * a qmail Delivered-To line, or a declared sender envelope line).
965 * But if we're mining addressees out of the To/Cc/Bcc fields, and
966 * if the mail is addressed to N people, each recipient will
967 * get N copies. This is bad when N > 1.
969 * Foil this by suppressing all but one copy of a message with a
970 * given set of headers.
972 * Note: This implementation only catches runs of successive
973 * messages with the same ID, but that should be good
974 * enough. A more general implementation would have to store
975 * ever-growing lists of seen message-IDs; in a long-running
976 * daemon this would turn into a memory leak even if the
977 * implementation were perfect.
979 * Don't mess with this code casually. It would be way too easy
980 * to break it in a way that blackholed mail. Better to pass
981 * the occasional duplicate than to do that...
984 * The real fix however is to insist on Delivered-To: or similar
985 * headers and require that one copy per recipient be dropped.
986 * Everything else breaks sooner or later.
988 if (MULTIDROP(ctl) && msgblk.headers)
993 MD5Update(&context, (unsigned char *)msgblk.headers, strlen(msgblk.headers));
994 MD5Final(ctl->digest, &context);
996 if (!received_for && env_offs == -1 && !delivered_to)
999 * Hmmm...can MD5 ever yield all zeroes as a hash value?
1000 * If so there is a one in 18-quadrillion chance this
1001 * code will incorrectly nuke the first message.
1003 if (!memcmp(ctl->lastdigest, ctl->digest, DIGESTLEN))
1006 memcpy(ctl->lastdigest, ctl->digest, DIGESTLEN);
1010 * Hack time. If the first line of the message was blank, with no headers
1011 * (this happens occasionally due to bad gatewaying software) cons up
1012 * a set of fake headers.
1014 * If you modify the fake header template below, be sure you don't
1015 * make either From or To address @-less, otherwise the reply_hack
1016 * logic will do bad things.
1018 if (msgblk.headers == (char *)NULL)
1020 snprintf(buf, sizeof(buf),
1021 "From: FETCHMAIL-DAEMON\r\n"
1023 "Subject: Headerless mail from %s's mailbox on %s\r\n",
1024 user, fetchmailhost, ctl->remotename, ctl->server.truename);
1025 msgblk.headers = xstrdup(buf);
1029 * We can now process message headers before reading the text.
1030 * In fact we have to, as this will tell us where to forward to.
1033 /* Check for MIME headers indicating possible 8-bit data */
1034 ctl->mimemsg = MimeBodyType(msgblk.headers, ctl->mimedecode);
1037 if (ctl->server.sdps && sdps_envfrom)
1039 /* We have the real envelope return-path, stored out of band by
1040 * SDPS - that's more accurate than any header is going to be.
1042 strlcpy(msgblk.return_path, sdps_envfrom, sizeof(msgblk.return_path));
1045 #endif /* SDPS_ENABLE */
1047 * If there is a Return-Path address on the message, this was
1048 * almost certainly the MAIL FROM address given the originating
1049 * sendmail. This is the best thing to use for logging the
1050 * message origin (it sets up the right behavior for bounces and
1051 * mailing lists). Otherwise, fall down to the next available
1052 * envelope address (which is the most probable real sender).
1053 * *** The order is important! ***
1054 * This is especially useful when receiving mailing list
1055 * messages in multidrop mode. if a local address doesn't
1056 * exist, the bounce message won't be returned blindly to the
1057 * author or to the list itself but rather to the list manager
1058 * (ex: specified by "Sender:") which is much less annoying. This
1059 * is true for most mailing list packages.
1061 if( !msgblk.return_path[0] ){
1063 if (resent_sender_offs >= 0 && (ap = nxtaddr(msgblk.headers + resent_sender_offs)));
1064 else if (sender_offs >= 0 && (ap = nxtaddr(msgblk.headers + sender_offs)));
1065 else if (resent_from_offs >= 0 && (ap = nxtaddr(msgblk.headers + resent_from_offs)));
1066 else if (from_offs >= 0 && (ap = nxtaddr(msgblk.headers + from_offs)));
1067 else if (reply_to_offs >= 0 && (ap = nxtaddr(msgblk.headers + reply_to_offs)));
1068 else if (app_from_offs >= 0 && (ap = nxtaddr(msgblk.headers + app_from_offs))) {}
1069 /* multi-line MAIL FROM addresses confuse SMTP terribly */
1070 if (ap && !strchr(ap, '\n')) {
1071 strncpy(msgblk.return_path, ap, sizeof(msgblk.return_path));
1072 msgblk.return_path[sizeof(msgblk.return_path)-1] = '\0';
1076 /* cons up a list of local recipients */
1077 msgblk.recipients = (struct idlist *)NULL;
1078 accept_count = reject_count = 0;
1079 /* is this a multidrop box? */
1083 if (ctl->server.sdps && sdps_envto)
1085 /* We have the real envelope recipient, stored out of band by
1086 * SDPS - that's more accurate than any header is going to be.
1088 find_server_names(sdps_envto, ctl, &msgblk.recipients);
1091 #endif /* SDPS_ENABLE */
1092 if (env_offs > -1) { /* We have the actual envelope addressee */
1093 if (outlevel >= O_DEBUG) {
1094 const char *tmps = msgblk.headers + env_offs;
1095 size_t l = strcspn(tmps, "\r\n");
1096 report(stdout, GT_("Parsing envelope \"%s\" names \"%-.*s\"\n"), ctl->server.envelope, UCAST_TO_INT(l), tmps);
1098 find_server_names(msgblk.headers + env_offs, ctl, &msgblk.recipients);
1100 else if (delivered_to && ctl->server.envelope != STRING_DISABLED &&
1101 ctl->server.envelope && !strcasecmp(ctl->server.envelope, "Delivered-To"))
1103 if (outlevel >= O_DEBUG) {
1104 const char *tmps = delivered_to + 2 + strlen(ctl->server.envelope);
1105 size_t l = strcspn(tmps, "\r\n");
1106 report(stdout, GT_("Parsing envelope \"%s\" names \"%-.*s\"\n"), ctl->server.envelope, UCAST_TO_INT(l), tmps);
1108 find_server_names(delivered_to, ctl, &msgblk.recipients);
1109 xfree(delivered_to);
1110 } else if (received_for) {
1112 * We have the Received for addressee.
1113 * It has to be a mailserver address, or we
1114 * wouldn't have got here.
1115 * We use find_server_names() to let local
1116 * hostnames go through.
1118 if (outlevel >= O_DEBUG) {
1119 const char *tmps = received_for + 2;
1120 size_t l = strcspn(tmps, "\r\n");
1121 report(stdout, GT_("Parsing Received names \"%-.*s\"\n"), UCAST_TO_INT(l), tmps);
1123 find_server_names(received_for, ctl, &msgblk.recipients);
1126 * We haven't extracted the envelope address.
1127 * So check all the "Resent-To" header addresses if
1128 * they exist. If and only if they don't, consider
1129 * the "To" addresses.
1131 register struct addrblk *nextptr;
1132 if (outlevel >= O_DEBUG)
1133 report(stdout, GT_("No envelope recipient found, resorting to header guessing.\n"));
1134 if (resent_to_addrchain) {
1135 /* delete the "To" chain and substitute it
1136 * with the "Resent-To" list
1138 while (to_addrchain) {
1139 nextptr = to_addrchain->next;
1141 to_addrchain = nextptr;
1143 to_addrchain = resent_to_addrchain;
1144 resent_to_addrchain = NULL;
1146 /* now look for remaining adresses */
1147 while (to_addrchain) {
1148 if (outlevel >= O_DEBUG) {
1149 const char *tmps = msgblk.headers+to_addrchain->offset;
1150 size_t l = strcspn(tmps, "\r\n");
1151 report(stdout, GT_("Guessing from header \"%-.*s\".\n"), UCAST_TO_INT(l), tmps);
1154 find_server_names(msgblk.headers+to_addrchain->offset, ctl, &msgblk.recipients);
1155 nextptr = to_addrchain->next;
1157 to_addrchain = nextptr;
1162 no_local_matches = TRUE;
1163 save_str(&msgblk.recipients, run.postmaster, XMIT_ACCEPT);
1164 if (outlevel >= O_DEBUG)
1166 GT_("no local matches, forwarding to %s\n"),
1170 else /* it's a single-drop box, use first localname */
1171 save_str(&msgblk.recipients, ctl->localnames->id, XMIT_ACCEPT);
1175 * Time to either address the message or decide we can't deliver it yet.
1177 if (ctl->errcount > olderrs) /* there were DNS errors above */
1179 if (outlevel >= O_DEBUG)
1181 GT_("forwarding and deletion suppressed due to DNS errors\n"));
1182 return(PS_TRANSIENT);
1186 /* set up stuffline() so we can deliver the message body through it */
1187 if ((n = open_sink(ctl, &msgblk,
1188 &good_addresses, &bad_addresses)) != PS_SUCCESS)
1196 * Some server/sendmail combinations cause problems when our
1197 * synthetic Received line is before the From header. Cope
1200 if ((rcv = strstr(msgblk.headers, "Received:")) == (char *)NULL)
1201 rcv = msgblk.headers;
1202 /* handle ">Received:" lines too */
1203 while (rcv > msgblk.headers && rcv[-1] != '\n')
1205 if (rcv > msgblk.headers)
1210 n = stuffline(ctl, msgblk.headers);
1213 if (!run.invisible && n != -1)
1215 /* utter any per-message Received information we need here */
1216 if (ctl->server.trueaddr) {
1220 e = getnameinfo(ctl->server.trueaddr, ctl->server.trueaddr_len,
1221 saddr, sizeof(saddr), NULL, 0,
1224 snprintf(saddr, sizeof(saddr), "(%-.*s)", (int)(sizeof(saddr) - 3), gai_strerror(e));
1225 snprintf(buf, sizeof(buf),
1226 "Received: from %s [%s]\r\n",
1227 ctl->server.truename, saddr);
1229 snprintf(buf, sizeof(buf),
1230 "Received: from %s\r\n", ctl->server.truename);
1232 n = stuffline(ctl, buf);
1236 * We SHOULD (RFC-2821 sec. 4.4/p. 53) make sure to only use
1237 * IANA registered protocol names here.
1239 snprintf(buf, sizeof(buf),
1240 "\tby %s with %s (fetchmail-%s",
1244 if (ctl->server.tracepolls)
1246 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
1247 " polling %s account %s",
1248 ctl->server.pollname,
1251 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
1255 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), ")\r\n");
1256 n = stuffline(ctl, buf);
1260 if (good_addresses == 0)
1262 snprintf(buf+1, sizeof(buf)-1, "for <%s> (by default); ",
1263 rcpt_address (ctl, run.postmaster, 0));
1265 else if (good_addresses == 1)
1267 for (idp = msgblk.recipients; idp; idp = idp->next)
1268 if (idp->val.status.mark == XMIT_ACCEPT)
1269 break; /* only report first address */
1271 snprintf(buf+1, sizeof(buf)-1,
1272 "for <%s>", rcpt_address (ctl, idp->id, 1));
1273 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf)-1,
1275 MULTIDROP(ctl) ? "multi-drop" : "single-drop");
1280 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "%s\r\n",
1282 n = stuffline(ctl, buf);
1288 n = stuffline(ctl, rcv); /* ship out rest of msgblk.headers */
1292 report(stdout, GT_("writing RFC822 msgblk.headers\n"));
1297 if (want_progress())
1300 /* write error notifications */
1301 if (no_local_matches || has_nuls || bad_addresses)
1304 char errhd[USERNAMELEN + POPBUFSIZE], *errmsg;
1307 strlcpy(errhd, "X-Fetchmail-Warning: ", sizeof(errhd));
1308 if (no_local_matches)
1310 if (reject_count != 1)
1311 strlcat(errhd, GT_("no recipient addresses matched declared local names"), sizeof(errhd));
1314 for (idp = msgblk.recipients; idp; idp = idp->next)
1315 if (idp->val.status.mark == XMIT_REJECT)
1317 snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd),
1318 GT_("recipient address %s didn't match any local name"), idp->id);
1324 if (errhd[sizeof("X-Fetchmail-Warning: ")])
1325 snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), "; ");
1326 snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd),
1327 GT_("message has embedded NULs"));
1332 if (errhd[sizeof("X-Fetchmail-Warning: ")])
1333 snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), "; ");
1334 snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd),
1335 GT_("SMTP listener rejected local recipient addresses: "));
1336 errlen = strlen(errhd);
1337 for (idp = msgblk.recipients; idp; idp = idp->next)
1338 if (idp->val.status.mark == XMIT_RCPTBAD)
1339 errlen += strlen(idp->id) + 2;
1341 errmsg = (char *)xmalloc(errlen + 3);
1342 strcpy(errmsg, errhd);
1343 for (idp = msgblk.recipients; idp; idp = idp->next)
1344 if (idp->val.status.mark == XMIT_RCPTBAD)
1346 strcat(errmsg, idp->id);
1348 strcat(errmsg, ", ");
1353 strcat(errmsg, "\r\n");
1355 /* ship out the error line */
1356 stuffline(ctl, errmsg);
1358 if (errmsg != errhd)
1362 /* issue the delimiter line */
1367 n = stuffline(ctl, buf);
1369 if ((size_t)n == strlen(buf))
1375 int readbody(int sock, struct query *ctl, flag forward, int len)
1376 /* read and dispose of a message body presented on sock */
1377 /* ctl: query control record */
1378 /* sock: to which the server is connected */
1379 /* len: length of message */
1380 /* forward: TRUE to forward */
1383 char buf[MSGBUFSIZE+4];
1385 flag issoftline = FALSE;
1388 * Pass through the text lines in the body.
1390 * Yes, this wants to be ||, not &&. The problem is that in the most
1391 * important delimited protocol, POP3, the length is not reliable.
1392 * As usual, the problem is Microsoft brain damage; see FAQ item S2.
1393 * So, for delimited protocols we need to ignore the length here and
1394 * instead drop out of the loop with a break statement when we see
1395 * the message delimiter.
1397 while (protocol->delimited || len > 0)
1399 set_timeout(mytimeout);
1400 /* XXX FIXME: for undelimited protocols that ship the size, such
1401 * as IMAP, we might want to use the count of remaining characters
1402 * instead of the buffer size -- not for fetchmail 6.3.X though */
1403 if ((linelen = SockRead(sock, inbufp, sizeof(buf)-4-(inbufp-buf)))==-1)
1411 /* write the message size dots */
1414 print_ticker(&sizeticker, linelen);
1417 /* Mike Jones, Manchester University, 2006:
1418 * "To fix IMAP MIME Messages in which fetchmail adds the remainder of
1419 * the IMAP packet including the ')' character (part of the IMAP)
1420 * Protocol causing the addition of an extra MIME boundary locally."
1422 * However, we shouldn't do this for delimited protocols:
1423 * many POP3 servers (Microsoft, qmail) goof up message sizes
1424 * so we might end truncating messages prematurely.
1426 if (!protocol->delimited && linelen > len) {
1432 /* check for end of message */
1433 if (protocol->delimited && *inbufp == '.')
1435 if (EMPTYLINE(inbufp+1))
1438 msgblk.msglen--; /* subtract the size of the dot escape */
1441 msgblk.msglen += linelen;
1443 if (ctl->mimedecode && (ctl->mimemsg & MSG_NEEDS_DECODE)) {
1444 issoftline = UnMimeBodyline(&inbufp, protocol->delimited, issoftline);
1445 if (issoftline && (sizeof(buf)-1-(inbufp-buf) < 200))
1448 * Soft linebreak, but less than 200 bytes left in
1449 * input buffer. Rather than doing a buffer overrun,
1450 * ignore the soft linebreak, NL-terminate data and
1451 * deliver what we have now.
1452 * (Who writes lines longer than 2K anyway?)
1454 *inbufp = '\n'; *(inbufp+1) = '\0';
1459 /* ship out the text line */
1460 if (forward && (!issoftline))
1465 /* guard against very long lines */
1466 buf[MSGBUFSIZE+1] = '\r';
1467 buf[MSGBUFSIZE+2] = '\n';
1468 buf[MSGBUFSIZE+3] = '\0';
1470 n = stuffline(ctl, buf);
1474 report(stdout, GT_("error writing message text\n"));
1478 else if (want_progress())
1489 void init_transact(const struct method *proto)
1490 /* initialize state for the send and receive functions */
1492 suppress_tags = FALSE;
1494 tag[0] = '\0'; /* nuke any tag hanging out from previous query */
1499 static void enshroud(char *buf)
1500 /* shroud a password in the given buffer */
1504 if (shroud[0] && (cp = strstr(buf, shroud)))
1508 sp = cp + strlen(shroud);
1516 #if defined(HAVE_STDARG_H)
1517 void gen_send(int sock, const char *fmt, ... )
1519 void gen_send(sock, fmt, va_alist)
1520 int sock; /* socket to which server is connected */
1521 const char *fmt; /* printf-style format */
1524 /* assemble command in printf(3) style and send to the server */
1526 char buf [MSGBUFSIZE+1];
1529 if (protocol->tagged && !suppress_tags)
1530 snprintf(buf, sizeof(buf) - 2, "%s ", GENSYM);
1534 #if defined(HAVE_STDARG_H)
1539 vsnprintf(buf + strlen(buf), sizeof(buf)-2-strlen(buf), fmt, ap);
1542 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1543 SockWrite(sock, buf, strlen(buf));
1545 if (outlevel >= O_MONITOR)
1548 buf[strlen(buf)-2] = '\0';
1549 report(stdout, "%s> %s\n", protocol->name, buf);
1553 /** get one line of input from the server */
1554 int gen_recv(int sock /** socket to which server is connected */,
1555 char *buf /* buffer to receive input */,
1556 int size /* length of buffer */)
1559 int oldphase = phase; /* we don't have to be re-entrant */
1561 phase = SERVER_WAIT;
1562 set_timeout(mytimeout);
1563 if (SockRead(sock, buf, size) == -1)
1567 if(is_idletimeout())
1570 return(PS_IDLETIMEOUT);
1579 if (n > 0 && buf[n-1] == '\n')
1581 if (n > 0 && buf[n-1] == '\r')
1583 if (outlevel >= O_MONITOR)
1584 report(stdout, "%s< %s\n", protocol->name, buf);
1591 * gen_recv_split() splits the response from a server which is too
1592 * long to fit into the buffer into multiple lines. If the prefix is
1593 * set as "MY FEATURES" and the response from the server is too long
1594 * to fit in the buffer, as in:
1596 * "MY FEATURES ABC DEF GHI JKLMNOPQRS TU VWX YZ"
1598 * Repeated calls to gen_recv_split() may return:
1600 * "MY FEATURES ABC DEF GHI"
1601 * "MY FEATURES JKLMNOPQRS"
1602 * "MY FEATURES TU VWX YZ"
1604 * A response not beginning with the prefix "MY FEATURES" will not be
1608 * - Declare a variable of type struct RecvSplit
1609 * - Call gen_recv_split_init() once
1610 * - Call gen_recv_split() in a loop, preferably with the same buffer
1611 * size as the "buf" array in struct RecvSplit
1614 /* If this happens, the calling site needs to be adjusted to set
1615 * a shorter prefix, or the prefix capacity needs to be raised in
1616 * struct RecvSplit. */
1617 __attribute__((noreturn))
1618 static void overrun(const char *f, size_t l)
1620 report(stderr, GT_("Buffer too small. This is a bug in the caller of %s:%lu.\n"), f, (unsigned long)l);
1624 void gen_recv_split_init (const char *prefix, struct RecvSplit *rs)
1626 if (strlcpy(rs->prefix, prefix, sizeof(rs->prefix)) > sizeof(rs->prefix))
1627 overrun(__FILE__, __LINE__);
1632 /** Function to split replies at blanks, and duplicate prefix.
1633 * gen_recv_split_init() must be called before this can be used. */
1634 int gen_recv_split(int sock /** socket to which server is connected */,
1635 char *buf /** buffer to receive input */,
1636 int size /** length of buffer, must be the same for all calls */,
1637 struct RecvSplit *rs /** cached information across calls */)
1640 int foundnewline = 0;
1642 int oldphase = phase; /* we don't have to be re-entrant */
1646 /* if this is not our first call, prepare the buffer */
1650 * if this condition is not met, we lose data
1651 * because the cached data does not fit into the buffer.
1652 * this cannot happen if size is the same throughout all calls.
1654 assert(strlen(rs->prefix) + strlen(rs->buf) + 1 <= (size_t)size);
1656 if ((strlcpy(buf, rs->prefix, size) >= (size_t)size)
1657 || (strlcat(buf, rs->buf, size) >= (size_t)size)) {
1658 overrun(__FILE__, __LINE__);
1662 /* clear the cache for the next call */
1667 if ((size_t)size > n) {
1670 phase = SERVER_WAIT;
1671 set_timeout(mytimeout);
1672 rr = SockRead(sock, buf + n, size - n);
1680 if (n > 0 && buf[n-1] == '\n')
1685 if (n > 0 && buf[n-1] == '\r')
1688 if (foundnewline /* we have found a complete line */
1689 || strncasecmp(buf, rs->prefix, strlen(rs->prefix)) /* mismatch in prefix */
1690 || !(p = strrchr(buf, ' ')) /* no space found in response */
1691 || p < buf + strlen(rs->prefix)) /* space is at the wrong location */
1693 if (outlevel >= O_MONITOR)
1694 report(stdout, "%s< %s\n", protocol->name, buf);
1698 /* we are ready to cache some information now. */
1700 if (strlcpy(rs->buf, p, sizeof(rs->buf)) >= sizeof(rs->buf)) {
1701 overrun(__FILE__, __LINE__);
1703 *p = '\0'; /* chop off what we've cached */
1704 if (outlevel >= O_MONITOR)
1705 report(stdout, "%s< %s\n", protocol->name, buf);
1706 if (outlevel >= O_DEBUG)
1707 report(stdout, "%s< %s%s...\n", protocol->name, rs->prefix, rs->buf);
1711 #if defined(HAVE_STDARG_H)
1712 int gen_transact(int sock, const char *fmt, ... )
1714 int gen_transact(int sock, fmt, va_alist)
1715 int sock; /* socket to which server is connected */
1716 const char *fmt; /* printf-style format */
1719 /* assemble command in printf(3) style, send to server, accept a response */
1722 char buf [MSGBUFSIZE+1];
1724 int oldphase = phase; /* we don't have to be re-entrant */
1726 phase = SERVER_WAIT;
1728 if (protocol->tagged && !suppress_tags)
1729 snprintf(buf, sizeof(buf) - 2, "%s ", GENSYM);
1733 #if defined(HAVE_STDARG_H)
1738 vsnprintf(buf + strlen(buf), sizeof(buf)-2-strlen(buf), fmt, ap);
1741 snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n");
1742 ok = SockWrite(sock, buf, strlen(buf));
1743 if (ok == -1 || (size_t)ok != strlen(buf)) {
1744 /* short write, bail out */
1748 if (outlevel >= O_MONITOR)
1751 buf[strlen(buf)-2] = '\0';
1752 report(stdout, "%s> %s\n", protocol->name, buf);
1755 /* we presume this does its own response echoing */
1756 ok = (protocol->parse_response)(sock, buf);
1762 /* transact.c ends here */