/* * transact.c -- transaction primitives for the fetchmail driver loop * * Copyright 2001 by Eric S. Raymond * For license terms, see the file COPYING in this directory. * * */ #include "config.h" #include #include #include /* isspace() */ #ifdef HAVE_MEMORY_H #include #endif /* HAVE_MEMORY_H */ #if defined(STDC_HEADERS) #include #endif #if defined(HAVE_UNISTD_H) #include #endif #if defined(HAVE_STDARG_H) #include #else #include #endif #ifdef HAVE_NET_SOCKET_H #include #endif #include "md5.h" #include "i18n.h" #include "socket.h" #include "fetchmail.h" #ifndef strstr /* glibc-2.1 declares this as a macro */ extern char *strstr(const char *, const char *); /* needed on sysV68 R3V7.1. */ #endif /* strstr */ int mytimeout; /* value of nonreponse timeout */ int suppress_tags; /* emit tags? */ char shroud[PASSWORDLEN*2+3]; /* string to shroud in debug output */ struct msgblk msgblk; char tag[TAGLEN]; static int tagnum; #define GENSYM (sprintf(tag, "A%04d", ++tagnum % TAGMOD), tag) static int accept_count, reject_count; static struct method *protocol; static void map_name(const char *name, struct query *ctl, struct idlist **xmit_names) /* add given name to xmit_names if it matches declared localnames */ /* name: name to map */ /* ctl: list of permissible aliases */ /* xmit_names: list of recipient names parsed out */ { const char *lname; int off = 0; lname = idpair_find(&ctl->localnames, name+off); if (!lname && ctl->wildcard) lname = name+off; if (lname != (char *)NULL) { if (outlevel >= O_DEBUG) report(stdout, GT_("mapped %s to local %s\n"), name, lname); save_str(xmit_names, lname, XMIT_ACCEPT); accept_count++; } } static void find_server_names(const char *hdr, struct query *ctl, struct idlist **xmit_names) /* parse names out of a RFC822 header into an ID list */ /* hdr: RFC822 header in question */ /* ctl: list of permissible aliases */ /* xmit_names: list of recipient names parsed out */ { if (hdr == (char *)NULL) return; else { char *cp; for (cp = nxtaddr((const unsigned char *)hdr); cp != NULL; cp = nxtaddr(NULL)) { char *atsign; /* * Handle empty address from a To: header containing only * a comment. */ if (!*cp) continue; /* * If the name of the user begins with a qmail virtual * domain prefix, ignore the prefix. Doing this here * means qvirtual will work either with ordinary name * mapping or with a localdomains option. */ if (ctl->server.qvirtual) { int sl = strlen(ctl->server.qvirtual); if (!strncasecmp((char *)cp, ctl->server.qvirtual, sl)) cp += sl; } if ((atsign = strchr((char *)cp, '@'))) { struct idlist *idp; /* * Does a trailing segment of the hostname match something * on the localdomains list? If so, save the whole name * and keep going. */ for (idp = ctl->server.localdomains; idp; idp = idp->next) { char *rhs; rhs = atsign + (strlen(atsign) - strlen((char *)idp->id)); if (rhs > atsign && (rhs[-1] == '.' || rhs[-1] == '@') && strcasecmp(rhs, (char *)idp->id) == 0) { if (outlevel >= O_DEBUG) report(stdout, GT_("passed through %s matching %s\n"), cp, idp->id); save_str(xmit_names, (const char *)cp, XMIT_ACCEPT); accept_count++; goto nomap; } } /* if we matched a local domain, idp != NULL */ if (!idp) { /* * Check to see if the right-hand part is an alias * or MX equivalent of the mailserver. If it's * not, skip this name. If it is, we'll keep * going and try to find a mapping to a client name. */ if (!is_host_alias(atsign+1, ctl)) { save_str(xmit_names, cp, XMIT_REJECT); reject_count++; continue; } } atsign[0] = '\0'; map_name(cp, ctl, xmit_names); nomap:; } } } } /* * Return zero on a syntactically invalid address, nz on a valid one. * * This used to be strchr(a, '.'), but it turns out that lines like this * * Received: from punt-1.mail.demon.net by mailstore for markb@ordern.com * id 938765929:10:27223:2; Fri, 01 Oct 99 08:18:49 GMT * * are not uncommon. So now we just check that the following token is * not itself an email address. */ #define VALID_ADDRESS(a) !strchr(a, '@') static char *parse_received(struct query *ctl, char *bufp) /* try to extract real address from the Received line */ /* If a valid Received: line is found, we return the full address in * a buffer which can be parsed from nxtaddr(). This is to ansure that * the local domain part of the address can be passed along in * find_server_names() if it contains one. * Note: We should return a dummy header containing the address * which makes nxtaddr() behave correctly. */ { char *base, *ok = (char *)NULL; static char rbuf[HOSTLEN + USERNAMELEN + 4]; #define RBUF_WRITE(value) if (tp < rbuf+sizeof(rbuf)-1) *tp++=value /* * Try to extract the real envelope addressee. We look here * specifically for the mailserver's Received line. * Note: this will only work for sendmail, or an MTA that * shares sendmail's convention for embedding the envelope * address in the Received line. Sendmail itself only * does this when the mail has a single recipient. */ if (outlevel >= O_DEBUG) report(stdout, GT_("analyzing Received line:\n%s"), bufp); /* search for whitepace-surrounded "by" followed by valid address */ for (base = bufp; ; base = ok + 2) { if (!(ok = strstr(base, "by"))) break; else if (!isspace((unsigned char)ok[-1]) || !isspace((unsigned char)ok[2])) continue; else { char *sp, *tp; /* extract space-delimited token after "by" */ for (sp = ok + 2; isspace((unsigned char)*sp); sp++) continue; tp = rbuf; for (; !isspace((unsigned char)*sp); sp++) RBUF_WRITE(*sp); *tp = '\0'; /* look for valid address */ if (VALID_ADDRESS(rbuf)) break; else ok = sp - 1; /* arrange to skip this token */ } } if (ok) { /* * If it's a DNS name of the mail server, look for the * recipient name after a following "for". Otherwise * punt. */ if (is_host_alias(rbuf, ctl)) { if (outlevel >= O_DEBUG) report(stdout, GT_("line accepted, %s is an alias of the mailserver\n"), rbuf); } else { if (outlevel >= O_DEBUG) report(stdout, GT_("line rejected, %s is not an alias of the mailserver\n"), rbuf); return(NULL); } /* search for whitepace-surrounded "for" followed by xxxx@yyyy */ for (base = ok + 4 + strlen(rbuf); ; base = ok + 2) { if (!(ok = strstr(base, "for"))) break; else if (!isspace((unsigned char)ok[-1]) || !isspace((unsigned char)ok[3])) continue; else { char *sp, *tp; /* extract space-delimited token after "for" */ for (sp = ok + 3; isspace((unsigned char)*sp); sp++) continue; tp = rbuf; for (; !isspace((unsigned char)*sp); sp++) RBUF_WRITE(*sp); *tp = '\0'; if (strchr(rbuf, '@')) break; else ok = sp - 1; /* arrange to skip this token */ } } if (ok) { flag want_gt = FALSE; char *sp, *tp; /* char after "for" could be space or a continuation newline */ for (sp = ok + 4; isspace((unsigned char)*sp); sp++) continue; tp = rbuf; RBUF_WRITE(':'); /* Here is the hack. This is to be friends */ RBUF_WRITE(' '); /* with nxtaddr()... */ if (*sp == '<') { want_gt = TRUE; sp++; } while (*sp == '@') /* skip routes */ while (*sp && *sp++ != ':') continue; while (*sp && (want_gt ? (*sp != '>') : !isspace((unsigned char)*sp)) && *sp != ';') if (!isspace((unsigned char)*sp)) { RBUF_WRITE(*sp); sp++; } else { /* uh oh -- whitespace here can't be right! */ ok = (char *)NULL; break; } RBUF_WRITE('\n'); *tp = '\0'; if (strlen(rbuf) <= 3) /* apparently nothing has been found */ ok = NULL; } else ok = (char *)NULL; } if (!ok) { if (outlevel >= O_DEBUG) report(stdout, GT_("no Received address found\n")); return(NULL); } else { if (outlevel >= O_DEBUG) { char *lf = rbuf + strlen(rbuf)-1; *lf = '\0'; if (outlevel >= O_DEBUG) report(stdout, GT_("found Received address `%s'\n"), rbuf+2); *lf = '\n'; } return(rbuf); } } /* shared by readheaders and readbody */ static int sizeticker; #define EMPTYLINE(s) (((s)[0] == '\r' && (s)[1] == '\n' && (s)[2] == '\0') \ || ((s)[0] == '\n' && (s)[1] == '\0')) static int end_of_header (const char *s) /* accept "\r*\n" as EOH in order to be bulletproof against broken survers */ { while (s[0] == '\r') s++; return (s[0] == '\n' && s[1] == '\0'); } int readheaders(int sock, long fetchlen, long reallen, struct query *ctl, int num, flag *suppress_readbody) /* read message headers and ship to SMTP or MDA */ /* sock: to which the server is connected */ /* fetchlen: length of message according to fetch response */ /* reallen: length of message according to getsizes */ /* ctl: query control record */ /* num: index of message */ /* suppress_readbody: whether call to readbody() should be supressed */ { struct addrblk { int offset; struct addrblk *next; }; struct addrblk *to_addrchain = NULL; struct addrblk **to_chainptr = &to_addrchain; struct addrblk *resent_to_addrchain = NULL; struct addrblk **resent_to_chainptr = &resent_to_addrchain; char buf[MSGBUFSIZE+1]; int from_offs, reply_to_offs, resent_from_offs; int app_from_offs, sender_offs, resent_sender_offs; int env_offs; char *received_for, *rcv, *cp; static char *delivered_to = NULL; int n, oldlen, ch, remaining, skipcount; size_t linelen; struct idlist *idp; flag no_local_matches = FALSE; flag has_nuls; int olderrs, good_addresses, bad_addresses; int retain_mail = 0, refuse_mail = 0; flag already_has_return_path = FALSE; sizeticker = 0; has_nuls = FALSE; msgblk.return_path[0] = '\0'; olderrs = ctl->errcount; /* read message headers */ msgblk.reallen = reallen; /* * We used to free the header block unconditionally at the end of * readheaders, but it turns out that if close_sink() hits an error * condition the code for sending bouncemail will actually look * at the freed storage and coredump... */ if (msgblk.headers) free(msgblk.headers); free_str_list(&msgblk.recipients); if (delivered_to) free(delivered_to); /* initially, no message digest */ memset(ctl->digest, '\0', sizeof(ctl->digest)); msgblk.headers = received_for = delivered_to = NULL; from_offs = reply_to_offs = resent_from_offs = app_from_offs = sender_offs = resent_sender_offs = env_offs = -1; oldlen = 0; msgblk.msglen = 0; skipcount = 0; ctl->mimemsg = 0; for (remaining = fetchlen; remaining > 0 || protocol->delimited; ) { char *line, *rline; int overlong = FALSE; line = xmalloc(sizeof(buf)); linelen = 0; line[0] = '\0'; do { do { char *sp, *tp; set_timeout(mytimeout); if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1) { set_timeout(0); free(line); free(msgblk.headers); msgblk.headers = NULL; return(PS_SOCKET); } set_timeout(0); /* * Smash out any NULs, they could wreak havoc later on. * Some network stacks seem to generate these at random, * especially (according to reports) at the beginning of the * first read. NULs are illegal in RFC822 format. */ for (sp = tp = buf; sp < buf + n; sp++) if (*sp) *tp++ = *sp; *tp = '\0'; n = tp - buf; } while (n == 0); remaining -= n; linelen += n; msgblk.msglen += n; /* * Try to gracefully handle the case where the length of a * line exceeds MSGBUFSIZE. */ if (n && buf[n-1] != '\n') { overlong = TRUE; rline = (char *) realloc(line, linelen + 1); if (rline == NULL) { free (line); return(PS_IOERR); } line = rline; memcpy(line + linelen - n, buf, n); line[linelen] = '\0'; ch = ' '; /* So the next iteration starts */ continue; } /* lines may not be properly CRLF terminated; fix this for qmail */ /* we don't want to overflow the buffer here */ if (ctl->forcecr && buf[n-1]=='\n' && (n==1 || buf[n-2]!='\r')) { char * tcp; rline = (char *) realloc(line, linelen + 2); if (rline == NULL) { free (line); return(PS_IOERR); } line = rline; memcpy(line + linelen - n, buf, n - 1); tcp = line + linelen - 1; *tcp++ = '\r'; *tcp++ = '\n'; *tcp++ = '\0'; n++; linelen++; } else { rline = (char *) realloc(line, linelen + 1); if (rline == NULL) { free (line); return(PS_IOERR); } line = rline; memcpy(line + linelen - n, buf, n + 1); } /* check for end of headers */ if (end_of_header(line)) { if (linelen != strlen (line)) has_nuls = TRUE; free(line); goto process_headers; } /* * Check for end of message immediately. If one of your folders * has been mangled, the delimiter may occur directly after the * header. */ if (protocol->delimited && line[0] == '.' && EMPTYLINE(line+1)) { if (outlevel > O_SILENT) report(stdout, GT_("message delimiter found while scanning headers\n")); if (suppress_readbody) *suppress_readbody = TRUE; if (linelen != strlen (line)) has_nuls = TRUE; free(line); goto process_headers; } /* * At least one brain-dead website (netmind.com) is known to * send out robotmail that's missing the RFC822 delimiter blank * line before the body! Without this check fetchmail segfaults. * With it, we treat such messages as spam and refuse them. */ if (!refuse_mail && !isspace((unsigned char)line[0]) && !strchr(line, ':')) { if (linelen != strlen (line)) has_nuls = TRUE; if (outlevel > O_SILENT) report(stdout, GT_("incorrect header line found while scanning headers\n")); if (outlevel >= O_VERBOSE) report (stdout, GT_("line: %s"), line); refuse_mail = 1; } /* check for RFC822 continuations */ set_timeout(mytimeout); ch = SockPeek(sock); set_timeout(0); } while (ch == ' ' || ch == '\t'); /* continuation to next line? */ /* write the message size dots */ if ((outlevel > O_SILENT && outlevel < O_VERBOSE) && linelen > 0) { sizeticker += linelen; while (sizeticker >= SIZETICKER) { if (outlevel > O_SILENT && run.showdots && !run.use_syslog) { fputc('.', stdout); fflush(stdout); } sizeticker -= SIZETICKER; } } /* * Decode MIME encoded headers. We MUST do this before * looking at the Content-Type / Content-Transfer-Encoding * headers (RFC 2046). */ if ( ctl->mimedecode ) { char *tcp; UnMimeHeader(line); /* the line is now shorter. So we retrace back till we find our terminating * combination \n\0, we move backwards to make sure that we don't catch som * \n\0 stored in the decoded part of the message */ for(tcp = line + linelen - 1; tcp > line && (*tcp != 0 || tcp[-1] != '\n'); tcp--); if(tcp > line) linelen = tcp - line; } /* skip processing if we are going to retain or refuse this mail */ if (retain_mail || refuse_mail) { free(line); continue; } /* we see an ordinary (non-header, non-message-delimiter line */ if (linelen != strlen (line)) has_nuls = TRUE; /* * The University of Washington IMAP server (the reference * implementation of IMAP4 written by Mark Crispin) relies * on being able to keep base-UID information in a special * message at the head of the mailbox. This message should * neither be deleted nor forwarded. */ #ifdef POP2_ENABLE /* * We disable this check under POP2 because there's no way to * prevent deletion of the message. So at least we ought to * forward it to the user so he or she will have some clue * that things have gone awry. */ #if INET6_ENABLE if (strncmp(protocol->service, "pop2", 4)) #else /* INET6_ENABLE */ if (protocol->port != 109) #endif /* INET6_ENABLE */ #endif /* POP2_ENABLE */ if (num == 1 && !strncasecmp(line, "X-IMAP:", 7)) { free(line); retain_mail = 1; continue; } /* * This code prevents fetchmail from becoming an accessory after * the fact to upstream sendmails with the `E' option on. It also * copes with certain brain-dead POP servers (like NT's) that pass * through Unix from_ lines. * * Either of these bugs can result in a non-RFC822 line at the * beginning of the headers. If fetchmail just passes it * through, the client listener may think the message has *no* * headers (since the first) line it sees doesn't look * RFC822-conformant) and fake up a set. * * What the user would see in this case is bogus (synthesized) * headers, followed by a blank line, followed by the >From, * followed by the real headers, followed by a blank line, * followed by text. * * We forestall this lossage by tossing anything that looks * like an escaped or passed-through From_ line in headers. * These aren't RFC822 so our conscience is clear... */ if (!strncasecmp(line, ">From ", 6) || !strncasecmp(line, "From ", 5)) { free(line); continue; } /* * We remove all Delivered-To: headers. * * This is to avoid false mail loops messages when delivering * local messages to and from a Postfix/qmail mailserver. */ if (ctl->dropdelivered && !strncasecmp(line, "Delivered-To:", 13)) { if (delivered_to) free(line); else delivered_to = line; continue; } /* * If we see a Status line, it may have been inserted by an MUA * on the mail host, or it may have been inserted by the server * program after the headers in the transaction stream. This * can actually hose some new-mail notifiers such as xbuffy, * which assumes any Status line came from a *local* MDA and * therefore indicates that the message has been seen. * * Some buggy POP servers (including at least the 3.3(20) * version of the one distributed with IMAP) insert empty * Status lines in the transaction stream; we'll chuck those * unconditionally. Nonempty ones get chucked if the user * turns on the dropstatus flag. */ { char *cp; if (!strncasecmp(line, "Status:", 7)) cp = line + 7; else if (!strncasecmp(line, "X-Mozilla-Status:", 17)) cp = line + 17; else cp = NULL; if (cp) { while (*cp && isspace((unsigned char)*cp)) cp++; if (!*cp || ctl->dropstatus) { free(line); continue; } } } if (ctl->rewrite) line = reply_hack(line, ctl->server.truename, &linelen); /* * OK, this is messy. If we're forwarding by SMTP, it's the * SMTP-receiver's job (according to RFC821, page 22, section * 4.1.1) to generate a Return-Path line on final delivery. * The trouble is, we've already got one because the * mailserver's SMTP thought *it* was responsible for final * delivery. * * Stash away the contents of Return-Path (as modified by reply_hack) * for use in generating MAIL FROM later on, then prevent the header * from being saved with the others. In effect, we strip it off here. * * If the SMTP server conforms to the standards, and fetchmail gets the * envelope sender from the Return-Path, the new Return-Path should be * exactly the same as the original one. * * We do *not* want to ignore empty Return-Path headers. These should * be passed through as a way of indicating that a message should * not trigger bounces if delivery fails. What we *do* need to do is * make sure we never try to rewrite such a blank Return-Path. We * handle this with a check for <> in the rewrite logic above. * * Also, if an email has multiple Return-Path: headers, we only * read the first occurance, as some spam email has more than one * Return-Path. * */ if ((already_has_return_path==FALSE) && !strncasecmp("Return-Path:", line, 12) && (cp = nxtaddr(line))) { already_has_return_path = TRUE; if (cp[0]=='\0') /* nxtaddr() strips the brackets... */ cp="<>"; strncpy(msgblk.return_path, cp, sizeof(msgblk.return_path)); msgblk.return_path[sizeof(msgblk.return_path)-1] = '\0'; if (!ctl->mda) { free(line); continue; } } if (!msgblk.headers) { oldlen = linelen; msgblk.headers = xmalloc(oldlen + 1); (void) memcpy(msgblk.headers, line, linelen); msgblk.headers[oldlen] = '\0'; free(line); line = msgblk.headers; } else { char *newhdrs; int newlen; newlen = oldlen + linelen; newhdrs = (char *) realloc(msgblk.headers, newlen + 1); if (newhdrs == NULL) { free(line); return(PS_IOERR); } msgblk.headers = newhdrs; memcpy(msgblk.headers + oldlen, line, linelen); msgblk.headers[newlen] = '\0'; free(line); line = msgblk.headers + oldlen; oldlen = newlen; } /* find offsets of various special headers */ if (!strncasecmp("From:", line, 5)) from_offs = (line - msgblk.headers); else if (!strncasecmp("Reply-To:", line, 9)) reply_to_offs = (line - msgblk.headers); else if (!strncasecmp("Resent-From:", line, 12)) resent_from_offs = (line - msgblk.headers); else if (!strncasecmp("Apparently-From:", line, 16)) app_from_offs = (line - msgblk.headers); /* * Netscape 4.7 puts "Sender: zap" in mail headers. Perverse... * * But a literal reading of RFC822 sec. 4.4.2 supports the idea * that Sender: *doesn't* have to be a working email address. * * The definition of the Sender header in RFC822 says, in * part, "The Sender mailbox specification includes a word * sequence which must correspond to a specific agent (i.e., a * human user or a computer program) rather than a standard * address." That implies that the contents of the Sender * field don't need to be a legal email address at all So * ignore any Sender or Resent-Sender lines unless they * contain @. * * (RFC2822 says the contents of Sender must be a valid mailbox * address, which is also what RFC822 4.4.4 implies.) */ else if (!strncasecmp("Sender:", line, 7) && (strchr(line, '@') || strchr(line, '!'))) sender_offs = (line - msgblk.headers); else if (!strncasecmp("Resent-Sender:", line, 14) && (strchr(line, '@') || strchr(line, '!'))) resent_sender_offs = (line - msgblk.headers); #ifdef __UNUSED__ else if (!strncasecmp("Message-Id:", line, 11)) { if (ctl->server.uidl) { char id[IDLEN+1]; line[IDLEN+12] = 0; /* prevent stack overflow */ sscanf(line+12, "%s", id); if (!str_find( &ctl->newsaved, num)) { struct idlist *new = save_str(&ctl->newsaved,id,UID_SEEN); new->val.status.num = num; } } } #endif /* __UNUSED__ */ /* if multidrop is on, gather addressee headers */ if (MULTIDROP(ctl)) { if (!strncasecmp("To:", line, 3) || !strncasecmp("Cc:", line, 3) || !strncasecmp("Bcc:", line, 4) || !strncasecmp("Apparently-To:", line, 14)) { *to_chainptr = xmalloc(sizeof(struct addrblk)); (*to_chainptr)->offset = (line - msgblk.headers); to_chainptr = &(*to_chainptr)->next; *to_chainptr = NULL; } else if (!strncasecmp("Resent-To:", line, 10) || !strncasecmp("Resent-Cc:", line, 10) || !strncasecmp("Resent-Bcc:", line, 11)) { *resent_to_chainptr = xmalloc(sizeof(struct addrblk)); (*resent_to_chainptr)->offset = (line - msgblk.headers); resent_to_chainptr = &(*resent_to_chainptr)->next; *resent_to_chainptr = NULL; } else if (ctl->server.envelope != STRING_DISABLED) { if (ctl->server.envelope && strcasecmp(ctl->server.envelope, "Received")) { if (env_offs == -1 && !strncasecmp(ctl->server.envelope, line, strlen(ctl->server.envelope))) { if (skipcount++ < ctl->server.envskip) continue; env_offs = (line - msgblk.headers); } } else if (!received_for && !strncasecmp("Received:", line, 9)) { if (skipcount++ < ctl->server.envskip) continue; received_for = parse_received(ctl, line); } } } } process_headers: if (retain_mail) { free(msgblk.headers); msgblk.headers = NULL; return(PS_RETAINED); } if (refuse_mail) return(PS_REFUSED); /* * This is the duplicate-message killer code. * * When mail delivered to a multidrop mailbox on the server is * addressed to multiple people on the client machine, there will * be one copy left in the box for each recipient. This is not a * problem if we have the actual recipient address to dispatch on * (e.g. because we've mined it out of sendmail trace headers, or * a qmail Delivered-To line, or a declared sender envelope line). * * But if we're mining addressees out of the To/Cc/Bcc fields, and * if the mail is addressed to N people, each recipient will * get N copies. This is bad when N > 1. * * Foil this by suppressing all but one copy of a message with a * given set of headers. * * Note: This implementation only catches runs of successive * messages with the same ID, but that should be good * enough. A more general implementation would have to store * ever-growing lists of seen message-IDs; in a long-running * daemon this would turn into a memory leak even if the * implementation were perfect. * * Don't mess with this code casually. It would be way too easy * to break it in a way that blackholed mail. Better to pass * the occasional duplicate than to do that... */ if (MULTIDROP(ctl)) { MD5_CTX context; MD5Init(&context); MD5Update(&context, msgblk.headers, strlen(msgblk.headers)); MD5Final(ctl->digest, &context); if (!received_for && env_offs == -1 && !delivered_to) { /* * Hmmm...can MD5 ever yield all zeroes as a hash value? * If so there is a one in 18-quadrillion chance this * code will incorrectly nuke the first message. */ if (!memcmp(ctl->lastdigest, ctl->digest, DIGESTLEN)) return(PS_REFUSED); } memcpy(ctl->lastdigest, ctl->digest, DIGESTLEN); } /* * Hack time. If the first line of the message was blank, with no headers * (this happens occasionally due to bad gatewaying software) cons up * a set of fake headers. * * If you modify the fake header template below, be sure you don't * make either From or To address @-less, otherwise the reply_hack * logic will do bad things. */ if (msgblk.headers == (char *)NULL) { #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "From: FETCHMAIL-DAEMON\r\nTo: %s@%s\r\nSubject: Headerless mail from %s's mailbox on %s\r\n", user, fetchmailhost, ctl->remotename, ctl->server.truename); msgblk.headers = xstrdup(buf); } /* * We can now process message headers before reading the text. * In fact we have to, as this will tell us where to forward to. */ /* Check for MIME headers indicating possible 8-bit data */ ctl->mimemsg = MimeBodyType(msgblk.headers, ctl->mimedecode); #ifdef SDPS_ENABLE if (ctl->server.sdps && sdps_envfrom) { /* We have the real envelope return-path, stored out of band by * SDPS - that's more accurate than any header is going to be. */ strcpy(msgblk.return_path, sdps_envfrom); free(sdps_envfrom); } else #endif /* SDPS_ENABLE */ /* * If there is a Return-Path address on the message, this was * almost certainly the MAIL FROM address given the originating * sendmail. This is the best thing to use for logging the * message origin (it sets up the right behavior for bounces and * mailing lists). Otherwise, fall down to the next available * envelope address (which is the most probable real sender). * *** The order is important! *** * This is especially useful when receiving mailing list * messages in multidrop mode. if a local address doesn't * exist, the bounce message won't be returned blindly to the * author or to the list itself but rather to the list manager * (ex: specified by "Sender:") which is much less annoying. This * is true for most mailing list packages. */ if( !msgblk.return_path[0] ){ char *ap = NULL; if (resent_sender_offs >= 0 && (ap = nxtaddr(msgblk.headers + resent_sender_offs))); else if (sender_offs >= 0 && (ap = nxtaddr(msgblk.headers + sender_offs))); else if (resent_from_offs >= 0 && (ap = nxtaddr(msgblk.headers + resent_from_offs))); else if (from_offs >= 0 && (ap = nxtaddr(msgblk.headers + from_offs))); else if (reply_to_offs >= 0 && (ap = nxtaddr(msgblk.headers + reply_to_offs))); else if (app_from_offs >= 0 && (ap = nxtaddr(msgblk.headers + app_from_offs))); /* multi-line MAIL FROM addresses confuse SMTP terribly */ if (ap && !strchr(ap, '\n')) { strncpy(msgblk.return_path, ap, sizeof(msgblk.return_path)); msgblk.return_path[sizeof(msgblk.return_path)-1] = '\0'; } } /* cons up a list of local recipients */ msgblk.recipients = (struct idlist *)NULL; accept_count = reject_count = 0; /* is this a multidrop box? */ if (MULTIDROP(ctl)) { #ifdef SDPS_ENABLE if (ctl->server.sdps && sdps_envto) { /* We have the real envelope recipient, stored out of band by * SDPS - that's more accurate than any header is going to be. */ find_server_names(sdps_envto, ctl, &msgblk.recipients); free(sdps_envto); } else #endif /* SDPS_ENABLE */ if (env_offs > -1) /* We have the actual envelope addressee */ find_server_names(msgblk.headers + env_offs, ctl, &msgblk.recipients); else if (delivered_to && ctl->server.envelope != STRING_DISABLED && ctl->server.envelope && !strcasecmp(ctl->server.envelope, "Delivered-To")) { find_server_names(delivered_to, ctl, &msgblk.recipients); free(delivered_to); delivered_to = NULL; } else if (received_for) /* * We have the Received for addressee. * It has to be a mailserver address, or we * wouldn't have got here. * We use find_server_names() to let local * hostnames go through. */ find_server_names(received_for, ctl, &msgblk.recipients); else { /* * We haven't extracted the envelope address. * So check all the "Resent-To" header addresses if * they exist. If and only if they don't, consider * the "To" addresses. */ register struct addrblk *nextptr; if (resent_to_addrchain) { /* delete the "To" chain and substitute it * with the "Resent-To" list */ while (to_addrchain) { nextptr = to_addrchain->next; free(to_addrchain); to_addrchain = nextptr; } to_addrchain = resent_to_addrchain; resent_to_addrchain = NULL; } /* now look for remaining adresses */ while (to_addrchain) { find_server_names(msgblk.headers+to_addrchain->offset, ctl, &msgblk.recipients); nextptr = to_addrchain->next; free(to_addrchain); to_addrchain = nextptr; } } if (!accept_count) { no_local_matches = TRUE; save_str(&msgblk.recipients, run.postmaster, XMIT_ACCEPT); if (outlevel >= O_DEBUG) report(stdout, GT_("no local matches, forwarding to %s\n"), run.postmaster); } } else /* it's a single-drop box, use first localname */ save_str(&msgblk.recipients, ctl->localnames->id, XMIT_ACCEPT); /* * Time to either address the message or decide we can't deliver it yet. */ if (ctl->errcount > olderrs) /* there were DNS errors above */ { if (outlevel >= O_DEBUG) report(stdout, GT_("forwarding and deletion suppressed due to DNS errors\n")); free(msgblk.headers); msgblk.headers = NULL; free_str_list(&msgblk.recipients); return(PS_TRANSIENT); } else { /* set up stuffline() so we can deliver the message body through it */ if ((n = open_sink(ctl, &msgblk, &good_addresses, &bad_addresses)) != PS_SUCCESS) { free(msgblk.headers); msgblk.headers = NULL; free_str_list(&msgblk.recipients); return(n); } } n = 0; /* * Some server/sendmail combinations cause problems when our * synthetic Received line is before the From header. Cope * with this... */ if ((rcv = strstr(msgblk.headers, "Received:")) == (char *)NULL) rcv = msgblk.headers; /* handle ">Received:" lines too */ while (rcv > msgblk.headers && rcv[-1] != '\n') rcv--; if (rcv > msgblk.headers) { char c = *rcv; *rcv = '\0'; n = stuffline(ctl, msgblk.headers); *rcv = c; } if (!run.invisible && n != -1) { /* utter any per-message Received information we need here */ if (ctl->server.trueaddr) { #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "Received: from %s [%u.%u.%u.%u]\r\n", ctl->server.truename, (unsigned int)(unsigned char)ctl->server.trueaddr[0], (unsigned int)(unsigned char)ctl->server.trueaddr[1], (unsigned int)(unsigned char)ctl->server.trueaddr[2], (unsigned int)(unsigned char)ctl->server.trueaddr[3]); } else { #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "Received: from %s\r\n", ctl->server.truename); } n = stuffline(ctl, buf); if (n != -1) { /* * This header is technically invalid under RFC822. * POP3, IMAP, etc. are not legal mail-parameter values. */ #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "\tby %s with %s (fetchmail-%s", fetchmailhost, protocol->name, VERSION); if (ctl->tracepolls) { sprintf(buf + strlen(buf), " polling %s account %s", ctl->server.pollname, ctl->remotename); } #ifdef HAVE_SNPRINTF snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), ")\r\n"); #else strcat(buf, ")\r\n"); #endif /* HAVE_SNPRINTF */ n = stuffline(ctl, buf); if (n != -1) { buf[0] = '\t'; if (good_addresses == 0) { #ifdef HAVE_SNPRINTF snprintf(buf+1, sizeof(buf)-1, #else sprintf(buf+1, #endif /* HAVE_SNPRINTF */ "for %s (by default); ", rcpt_address (ctl, run.postmaster, 0)); } else if (good_addresses == 1) { for (idp = msgblk.recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_ACCEPT) break; /* only report first address */ #ifdef HAVE_SNPRINTF snprintf(buf+1, sizeof(buf)-1, #else sprintf(buf+1, #endif /* HAVE_SNPRINTF */ "for %s", rcpt_address (ctl, idp->id, 1)); sprintf(buf+strlen(buf), " (%s); ", MULTIDROP(ctl) ? "multi-drop" : "single-drop"); } else buf[1] = '\0'; #ifdef HAVE_SNPRINTF snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "%s\r\n", rfc822timestamp()); #else strcat(buf, rfc822timestamp()); strcat(buf, "\r\n"); #endif /* HAVE_SNPRINTF */ n = stuffline(ctl, buf); } } } if (n != -1) n = stuffline(ctl, rcv); /* ship out rest of msgblk.headers */ if (n == -1) { report(stdout, GT_("writing RFC822 msgblk.headers\n")); release_sink(ctl); free(msgblk.headers); msgblk.headers = NULL; free_str_list(&msgblk.recipients); return(PS_IOERR); } else if ((run.poll_interval == 0 || nodetach) && outlevel >= O_VERBOSE && !isafile(2)) fputs("#", stdout); /* write error notifications */ if (no_local_matches || has_nuls || bad_addresses) { int errlen = 0; char errhd[USERNAMELEN + POPBUFSIZE], *errmsg; errmsg = errhd; (void) strcpy(errhd, "X-Fetchmail-Warning: "); if (no_local_matches) { if (reject_count != 1) strcat(errhd, GT_("no recipient addresses matched declared local names")); else { for (idp = msgblk.recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_REJECT) break; #ifdef HAVE_SNPRINTF snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), #else sprintf(errhd+strlen(errhd), #endif /* HAVE_SNPRINTF */ GT_("recipient address %s didn't match any local name"), idp->id); } } if (has_nuls) { if (errhd[sizeof("X-Fetchmail-Warning: ")]) #ifdef HAVE_SNPRINTF snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), "; "); snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), #else strcat(errhd, "; "); strcat(errhd, #endif /* HAVE_SNPRINTF */ GT_("message has embedded NULs")); } if (bad_addresses) { if (errhd[sizeof("X-Fetchmail-Warning: ")]) #ifdef HAVE_SNPRINTF snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), "; "); snprintf(errhd+strlen(errhd), sizeof(errhd)-strlen(errhd), #else strcat(errhd, "; "); strcat(errhd, #endif /* HAVE_SNPRINTF */ GT_("SMTP listener rejected local recipient addresses: ")); errlen = strlen(errhd); for (idp = msgblk.recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_RCPTBAD) errlen += strlen(idp->id) + 2; xalloca(errmsg, char *, errlen+3); (void) strcpy(errmsg, errhd); for (idp = msgblk.recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_RCPTBAD) { strcat(errmsg, idp->id); if (idp->next) strcat(errmsg, ", "); } } strcat(errmsg, "\r\n"); /* ship out the error line */ stuffline(ctl, errmsg); } /* issue the delimiter line */ cp = buf; *cp++ = '\r'; *cp++ = '\n'; *cp++ = '\0'; stuffline(ctl, buf); return(PS_SUCCESS); } int readbody(int sock, struct query *ctl, flag forward, int len) /* read and dispose of a message body presented on sock */ /* ctl: query control record */ /* sock: to which the server is connected */ /* len: length of message */ /* forward: TRUE to forward */ { int linelen; unsigned char buf[MSGBUFSIZE+4]; unsigned char *inbufp = buf; flag issoftline = FALSE; /* * Pass through the text lines in the body. * * Yes, this wants to be ||, not &&. The problem is that in the most * important delimited protocol, POP3, the length is not reliable. * As usual, the problem is Microsoft brain damage; see FAQ item S2. * So, for delimited protocols we need to ignore the length here and * instead drop out of the loop with a break statement when we see * the message delimiter. */ while (protocol->delimited || len > 0) { set_timeout(mytimeout); if ((linelen = SockRead(sock, inbufp, sizeof(buf)-4-(inbufp-buf)))==-1) { set_timeout(0); release_sink(ctl); return(PS_SOCKET); } set_timeout(0); /* write the message size dots */ if (linelen > 0) { sizeticker += linelen; while (sizeticker >= SIZETICKER) { if (outlevel > O_SILENT && run.showdots && !run.use_syslog) { fputc('.', stdout); fflush(stdout); } sizeticker -= SIZETICKER; } } len -= linelen; /* check for end of message */ if (protocol->delimited && *inbufp == '.') { if (EMPTYLINE(inbufp+1)) break; else msgblk.msglen--; /* subtract the size of the dot escape */ } msgblk.msglen += linelen; if (ctl->mimedecode && (ctl->mimemsg & MSG_NEEDS_DECODE)) { issoftline = UnMimeBodyline(&inbufp, protocol->delimited, issoftline); if (issoftline && (sizeof(buf)-1-(inbufp-buf) < 200)) { /* * Soft linebreak, but less than 200 bytes left in * input buffer. Rather than doing a buffer overrun, * ignore the soft linebreak, NL-terminate data and * deliver what we have now. * (Who writes lines longer than 2K anyway?) */ *inbufp = '\n'; *(inbufp+1) = '\0'; issoftline = 0; } } /* ship out the text line */ if (forward && (!issoftline)) { int n; inbufp = buf; /* guard against very long lines */ buf[MSGBUFSIZE+1] = '\r'; buf[MSGBUFSIZE+2] = '\n'; buf[MSGBUFSIZE+3] = '\0'; n = stuffline(ctl, buf); if (n < 0) { report(stdout, GT_("writing message text\n")); release_sink(ctl); return(PS_IOERR); } else if (outlevel >= O_VERBOSE && !isafile(1)) { fputc('*', stdout); fflush(stdout); } } } return(PS_SUCCESS); } void init_transact(const struct method *proto) /* initialize state for the send and receive functions */ { tagnum = 0; tag[0] = '\0'; /* nuke any tag hanging out from previous query */ protocol = (struct method *)proto; } static void enshroud(char *buf) /* shroud a password in the given buffer */ { char *cp; if (shroud[0] && (cp = strstr(buf, shroud))) { char *sp; sp = cp + strlen(shroud); *cp++ = '*'; while (*sp) *cp++ = *sp++; *cp = '\0'; } } #if defined(HAVE_STDARG_H) void gen_send(int sock, const char *fmt, ... ) #else void gen_send(sock, fmt, va_alist) int sock; /* socket to which server is connected */ const char *fmt; /* printf-style format */ va_dcl #endif /* assemble command in printf(3) style and send to the server */ { char buf [MSGBUFSIZE+1]; va_list ap; if (protocol->tagged && !suppress_tags) (void) sprintf(buf, "%s ", GENSYM); else buf[0] = '\0'; #if defined(HAVE_STDARG_H) va_start(ap, fmt); #else va_start(ap); #endif #ifdef HAVE_VSNPRINTF vsnprintf(buf + strlen(buf), sizeof(buf)-strlen(buf), fmt, ap); #else vsprintf(buf + strlen(buf), fmt, ap); #endif va_end(ap); #ifdef HAVE_SNPRINTF snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n"); #else strcat(buf, "\r\n"); #endif /* HAVE_SNPRINTF */ SockWrite(sock, buf, strlen(buf)); if (outlevel >= O_MONITOR) { enshroud(buf); buf[strlen(buf)-2] = '\0'; report(stdout, "%s> %s\n", protocol->name, buf); } } int gen_recv(sock, buf, size) /* get one line of input from the server */ int sock; /* socket to which server is connected */ char *buf; /* buffer to receive input */ int size; /* length of buffer */ { int oldphase = phase; /* we don't have to be re-entrant */ phase = SERVER_WAIT; set_timeout(mytimeout); if (SockRead(sock, buf, size) == -1) { set_timeout(0); phase = oldphase; if(isidletimeout()) { resetidletimeout(); return(PS_IDLETIMEOUT); } else return(PS_SOCKET); } else { set_timeout(0); if (buf[strlen(buf)-1] == '\n') buf[strlen(buf)-1] = '\0'; if (buf[strlen(buf)-1] == '\r') buf[strlen(buf)-1] = '\0'; if (outlevel >= O_MONITOR) report(stdout, "%s< %s\n", protocol->name, buf); phase = oldphase; return(PS_SUCCESS); } } #if defined(HAVE_STDARG_H) int gen_transact(int sock, const char *fmt, ... ) #else int gen_transact(int sock, fmt, va_alist) int sock; /* socket to which server is connected */ const char *fmt; /* printf-style format */ va_dcl #endif /* assemble command in printf(3) style, send to server, accept a response */ { int ok; char buf [MSGBUFSIZE+1]; va_list ap; int oldphase = phase; /* we don't have to be re-entrant */ phase = SERVER_WAIT; if (protocol->tagged && !suppress_tags) (void) sprintf(buf, "%s ", GENSYM); else buf[0] = '\0'; #if defined(HAVE_STDARG_H) va_start(ap, fmt) ; #else va_start(ap); #endif #ifdef HAVE_VSNPRINTF vsnprintf(buf + strlen(buf), sizeof(buf)-strlen(buf), fmt, ap); #else vsprintf(buf + strlen(buf), fmt, ap); #endif va_end(ap); #ifdef HAVE_SNPRINTF snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n"); #else strcat(buf, "\r\n"); #endif /* HAVE_SNPRINTF */ SockWrite(sock, buf, strlen(buf)); if (outlevel >= O_MONITOR) { enshroud(buf); buf[strlen(buf)-2] = '\0'; report(stdout, "%s> %s\n", protocol->name, buf); } /* we presume this does its own response echoing */ ok = (protocol->parse_response)(sock, buf); phase = oldphase; return(ok); } /* transact.c ends here */