/* * driver.c -- generic driver for mail fetch method protocols * * Copyright 1997 by Eric S. Raymond * For license terms, see the file COPYING in this directory. */ /* Modified 1998 by Dominique Unruh (doesn't block any more, when message delimiter follows up directly to the headers) */ #include "config.h" #include #include #include #include #include #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 #if defined(HAVE_ALLOCA_H) #include #else #ifdef _AIX #pragma alloca #endif #endif #if defined(HAVE_SYS_ITIMER_H) #include #endif #include #include #ifndef HAVE_STRFTIME /* For ctime prototype */ #include #include #endif #ifdef HAVE_GETHOSTBYNAME #include #include "mx.h" #endif /* HAVE_GETHOSTBYNAME */ #ifdef KERBEROS_V4 #if defined (__bsdi__) #include /* order of includes matters */ #include #define krb_get_err_text(e) (krb_err_txt[e]) #else #if defined(__FreeBSD__) || defined(__linux__) #define krb_get_err_text(e) (krb_err_txt[e]) #include #include #else #include #include #endif /* ! defined (__FreeBSD__) */ #endif /* ! defined (__bsdi__) */ #include #include #endif /* KERBEROS_V4 */ #ifdef KERBEROS_V5 #include #include #endif /* KEREROS_V5 */ #include "fetchmail.h" #include "socket.h" #include "smtp.h" /* BSD portability hack...I know, this is an ugly place to put it */ #if !defined(SIGCHLD) && defined(SIGCLD) #define SIGCHLD SIGCLD #endif #if INET6 #define SMTP_PORT "smtp" /* standard SMTP service port */ #else /* INET6 */ #define SMTP_PORT 25 /* standard SMTP service port */ #endif /* INET6 */ #ifndef strstr /* glibc-2.1 declares this as a macro */ extern char *strstr(); /* needed on sysV68 R3V7.1. */ #endif /* strstr */ int fetchlimit; /* how often to tear down the server connection */ int batchcount; /* count of messages sent in current batch */ flag peek_capable; /* can we peek for better error recovery? */ int pass; /* how many times have we re-polled? */ static const struct method *protocol; static jmp_buf restart; char tag[TAGLEN]; static int tagnum; #define GENSYM (sprintf(tag, "A%04d", ++tagnum % TAGMOD), tag) static char *shroud; /* string to shroud in debug output, if non-NULL */ static int mytimeout; /* value of nonreponse timeout */ static int msglen; /* actual message length */ /* use these to track what was happening when the nonresponse timer fired */ #define GENERAL_WAIT 0 #define SERVER_WAIT 1 #define FORWARDING_WAIT 2 static phase; static void set_timeout(int timeleft) /* reset the nonresponse-timeout */ { #ifndef __EMX__ struct itimerval ntimeout; ntimeout.it_interval.tv_sec = ntimeout.it_interval.tv_usec = 0; ntimeout.it_value.tv_sec = timeleft; ntimeout.it_value.tv_usec = 0; setitimer(ITIMER_REAL, &ntimeout, (struct itimerval *)NULL); #endif } static void timeout_handler (int signal) /* handle server-timeout SIGALRM signal */ { longjmp(restart, 1); } #define XMIT_ACCEPT 1 #define XMIT_REJECT 2 #define XMIT_ANTISPAM 3 static int accept_count, reject_count; #define MX_RETRIES 3 static int is_host_alias(const char *name, struct query *ctl) /* determine whether name is a DNS alias of the hostname */ { struct hostent *he; struct mxentry *mxp, *mxrecords; struct hostdata *lead_server = ctl->server.lead_server ? ctl->server.lead_server : &ctl->server; /* * The first two checks are optimizations that will catch a good * many cases. * * (1) check against the `true name' deduced from the poll label * and the via option (if present) at the beginning of the poll cycle. * Odds are good this will either be the mailserver's FQDN or a suffix of * it with the mailserver's domain's default host name omitted. * * (2) Then check the rest of the `also known as' * cache accumulated by previous DNS checks. This cache is primed * by the aka list option. * * Any of these on a mail address is definitive. Only if the * name doesn't match any is it time to call the bind library. * If this happens odds are good we're looking at an MX name. */ if (strcasecmp(lead_server->truename, name) == 0) return(TRUE); else if (str_in_list(&lead_server->akalist, name)) return(TRUE); else if (!ctl->server.dns) return(FALSE); #ifndef HAVE_RES_SEARCH return(FALSE); #else /* * The only code that calls the BIND library is here and in the * start-of-query probe with gethostbyname(3). * * We know DNS service was up at the beginning of this poll cycle. * If it's down, our nameserver has crashed. We don't want to try * delivering the current message or anything else from this * mailbox until it's back up. */ else if ((he = gethostbyname(name)) != (struct hostent *)NULL) { if (strcasecmp(ctl->server.truename, he->h_name) == 0) goto match; else return(FALSE); } else switch (h_errno) { case HOST_NOT_FOUND: /* specified host is unknown */ case NO_ADDRESS: /* valid, but does not have an IP address */ break; case NO_RECOVERY: /* non-recoverable name server error */ case TRY_AGAIN: /* temporary error on authoritative server */ default: if (outlevel != O_SILENT) putchar('\n'); /* terminate the progress message */ error(0, 0, "nameserver failure while looking for `%s' during poll of %s.", name, ctl->server.pollname); ctl->errcount++; break; } /* * We're only here if DNS was OK but the gethostbyname() failed * with a HOST_NOT_FOUND or NO_ADDRESS error. * Search for a name match on MX records pointing to the server. */ h_errno = 0; if ((mxrecords = getmxrecords(name)) == (struct mxentry *)NULL) { switch (h_errno) { case HOST_NOT_FOUND: /* specified host is unknown */ case NO_ADDRESS: /* valid, but does not have an IP address */ return(FALSE); break; case NO_RECOVERY: /* non-recoverable name server error */ case TRY_AGAIN: /* temporary error on authoritative server */ default: error(0, -1, "nameserver failure while looking for `%s' during poll of %s.", name, ctl->server.pollname); ctl->errcount++; break; } } else { for (mxp = mxrecords; mxp->name; mxp++) if (strcasecmp(ctl->server.truename, mxp->name) == 0) goto match; return(FALSE); match:; } /* add this name to relevant server's `also known as' list */ save_str(&lead_server->akalist, -1, name); return(TRUE); #endif /* HAVE_RES_SEARCH */ } static void map_name(name, ctl, xmit_names) /* add given name to xmit_names if it matches declared localnames */ const char *name; /* name to map */ struct query *ctl; /* list of permissible aliases */ struct idlist **xmit_names; /* list of recipient names parsed out */ { const char *lname; int sl; int off = 0; lname = idpair_find(&ctl->localnames, name); if (!lname && ctl->wildcard) lname = name; if (lname != (char *)NULL) { /* * If the name of the user begins with a * qmail virtual domain prefix, remove * the prefix */ if (ctl->server.qvirtual) { sl=strlen(ctl->server.qvirtual); if (!strncasecmp(lname,ctl->server.qvirtual,sl)) off=sl; } if (outlevel == O_VERBOSE) error(0, 0, "mapped %s to local %s", name, lname+off); save_str(xmit_names, XMIT_ACCEPT, lname+off); accept_count++; } } void find_server_names(hdr, ctl, xmit_names) /* parse names out of a RFC822 header into an ID list */ const char *hdr; /* RFC822 header in question */ struct query *ctl; /* list of permissible aliases */ struct idlist **xmit_names; /* list of recipient names parsed out */ { if (hdr == (char *)NULL) return; else { char *cp; for (cp = nxtaddr(hdr); cp != NULL; cp = nxtaddr(NULL)) { char *atsign; if ((atsign = strchr(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(idp->id)); if (rhs > atsign && (rhs[-1] == '.' || rhs[-1] == '@') && strcasecmp(rhs, idp->id) == 0) { if (outlevel == O_VERBOSE) error(0, 0, "passed through %s matching %s", cp, idp->id); save_str(xmit_names, XMIT_ACCEPT, cp); accept_count++; break; } } /* if we matched a local domain, idp != NULL */ if (idp) continue; /* * 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, XMIT_REJECT, cp); reject_count++; continue; } atsign[0] = '\0'; } map_name(cp, ctl, xmit_names); } } } 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 wich 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 *ok = (char *)NULL; static char rbuf[HOSTLEN + USERNAMELEN + 4]; /* * 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 ((ok = strstr(bufp, "by ")) && isspace(ok[-1])) { char *sp, *tp; /* extract space-delimited token after "by " */ for (sp = ok + 3; isspace(*sp); sp++) continue; tp = rbuf; for (; !isspace(*sp); sp++) *tp++ = *sp; *tp = '\0'; /* * 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) && (ok = strstr(sp, "for ")) && isspace(ok[-1])) { tp = rbuf; sp = ok + 4; *tp++ = ':'; /* Here is the hack. This is to be friend */ *tp++ = ' '; /* with nxtaddr()... */ if (*sp == '<') sp++; while (*sp == '@') /* skip routes */ while (*sp && *sp++ != ':') continue; while (*sp && *sp != '>' && *sp != ';') if (!isspace(*sp)) *tp++ = *sp++; else { /* uh oh -- whitespace here can't be right! */ ok = (char *)NULL; break; } *tp++ = '\n'; *tp = '\0'; if (strlen(rbuf) <= 3) /* apparently nothing has been found */ ok = NULL; } else ok = (char *)NULL; } if (!ok) return(NULL); else { if (outlevel == O_VERBOSE) { char *lf = rbuf + strlen(rbuf)-1; *lf = '\0'; error(0, 0, "found Received address `%s'", rbuf+2); *lf = '\n'; } return(rbuf); } } static int smtp_open(struct query *ctl) /* try to open a socket to the appropriate SMTP server for this query */ { /* maybe it's time to close the socket in order to force delivery */ if (NUM_NONZERO(ctl->batchlimit) && (ctl->smtp_socket != -1) && batchcount++ == ctl->batchlimit) { close(ctl->smtp_socket); ctl->smtp_socket = -1; batchcount = 0; } /* if no socket to any SMTP host is already set up, try to open one */ if (ctl->smtp_socket == -1) { /* * RFC 1123 requires that the domain name in HELO address is a * "valid principal domain name" for the client host. If we're * running in invisible mode, violate this with malice * aforethought in order to make the Received headers and * logging look right. * * In fact this code relies on the RFC1123 requirement that the * SMTP listener must accept messages even if verification of the * HELO name fails (RFC1123 section 5.2.5, paragraph 2). * * How we compute the true mailhost name to pass to the * listener doesn't affect behavior on RFC1123- violating * listener that check for name match; we're going to lose * on those anyway because we can never give them a name * that matches the local machine fetchmail is running on. * What it will affect is the listener's logging. */ struct idlist *idp; char *id_me = use_invisible ? ctl->server.truename : fetchmailhost; errno = 0; /* * Run down the SMTP hunt list looking for a server that's up. * Use both explicit hunt entries (value TRUE) and implicit * (default) ones (value FALSE). */ for (idp = ctl->smtphunt; idp; idp = idp->next) { char *cp, *parsed_host = alloca(strlen(idp->id) + 1); #ifdef INET6 char *portnum = SMTP_PORT; #else int portnum = SMTP_PORT; #endif /* INET6 */ ctl->smtphost = idp->id; /* remember last host tried. */ strcpy(parsed_host, idp->id); if ((cp = strrchr(parsed_host, '/'))) { *cp++ = 0; #ifdef INET6 portnum = cp; #else portnum = atoi(cp); #endif /* INET6 */ } if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL)) == -1) continue; /* first, probe for ESMTP */ if (SMTP_ok(ctl->smtp_socket) == SM_OK && SMTP_ehlo(ctl->smtp_socket, id_me, &ctl->server.esmtp_options) == SM_OK) break; /* success */ /* * RFC 1869 warns that some listeners hang up on a failed EHLO, * so it's safest not to assume the socket will still be good. */ close(ctl->smtp_socket); ctl->smtp_socket = -1; /* if opening for ESMTP failed, try SMTP */ if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,NULL)) == -1) continue; if (SMTP_ok(ctl->smtp_socket) == SM_OK && SMTP_helo(ctl->smtp_socket, id_me) == SM_OK) break; /* success */ close(ctl->smtp_socket); ctl->smtp_socket = -1; } } if (outlevel >= O_VERBOSE && ctl->smtp_socket != -1) error(0, 0, "forwarding to %s", ctl->smtphost); return(ctl->smtp_socket); } /* these are shared by stuffline, readheaders and readbody */ static FILE *sinkfp; static RETSIGTYPE (*sigchld)(); static int sizeticker; static int stuffline(struct query *ctl, char *buf) /* ship a line to the given control block's output sink (SMTP server or MDA) */ { int n, oldphase; char *last; /* The line may contain NUL characters. Find the last char to use * -- the real line termination is the sequence "\n\0". */ last = buf; while ((last += strlen(last)) && (last[-1] != '\n')) last++; /* fix message lines that have only \n termination (for qmail) */ if (ctl->forcecr) { if (last - 1 == buf || last[-2] != '\r') { last[-1] = '\r'; *last++ = '\n'; *last = '\0'; } } oldphase = phase; phase = FORWARDING_WAIT; /* * SMTP byte-stuffing. We only do this if the protocol does *not* * use . as EOM. If it does, the server will already have * decorated any . lines it sends back up. */ if (*buf == '.') if (protocol->delimited) /* server has already byte-stuffed */ { if (ctl->mda) ++buf; else /* writing to SMTP, leave the byte-stuffing in place */; } else /* if (!protocol->delimited) -- not byte-stuffed already */ { if (!ctl->mda) SockWrite(ctl->smtp_socket, buf, 1); /* byte-stuff it */ else /* leave it alone */; } /* we may need to strip carriage returns */ if (ctl->stripcr) { char *sp, *tp; for (sp = tp = buf; sp < last; sp++) if (*sp != '\r') *tp++ = *sp; *tp = '\0'; last = tp; } n = 0; if (ctl->mda) n = fwrite(buf, 1, last - buf, sinkfp); else if (ctl->smtp_socket != -1) n = SockWrite(ctl->smtp_socket, buf, last - buf); phase = oldphase; return(n); } #define EMPTYLINE(s) ((s)[0] == '\r' && (s)[1] == '\n' && (s)[2] == '\0') static int readheaders(sock, fetchlen, reallen, ctl, num) /* read message headers and ship to SMTP or MDA */ int sock; /* to which the server is connected */ long fetchlen; /* length of message according to fetch response */ long reallen; /* length of message according to getsizes */ struct query *ctl; /* query control record */ int num; /* index of message */ { 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]; char return_path[HOSTLEN + USERNAMELEN + 4]; int from_offs, reply_to_offs, resent_from_offs; int app_from_offs, sender_offs, resent_sender_offs; int ctt_offs, env_offs; char *headers, *received_for, *destaddr, *rcv, *cp; int n, linelen, oldlen, ch, remaining, skipcount; struct idlist *idp, *xmit_names; flag good_addresses, bad_addresses, has_nuls; flag no_local_matches = FALSE; flag headers_ok; int olderrs; sizeticker = 0; has_nuls = headers_ok = FALSE; return_path[0] = '\0'; olderrs = ctl->errcount; /* read message headers */ headers = received_for = NULL; from_offs = reply_to_offs = resent_from_offs = app_from_offs = sender_offs = resent_sender_offs = ctt_offs = env_offs = -1; oldlen = 0; msglen = 0; skipcount = 0; for (remaining = fetchlen; remaining > 0 || protocol->delimited; remaining -= linelen) { char *line; line = xmalloc(sizeof(buf)); linelen = 0; line[0] = '\0'; do { if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1) { free(line); free(headers); return(PS_SOCKET); } linelen += n; msglen += n; /* lines may not be properly CRLF terminated; fix this for qmail */ if (ctl->forcecr) { cp = buf + strlen(buf) - 1; if (*cp == '\n' && (cp == buf || cp[-1] != '\r')) { *cp++ = '\r'; *cp++ = '\n'; *cp++ = '\0'; } } set_timeout(ctl->server.timeout); line = (char *) realloc(line, strlen(line) + strlen(buf) +1); strcat(line, buf); /* check for end of headers */ if (EMPTYLINE(line)) { headers_ok = TRUE; has_nuls = (linelen != strlen(line)); 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)) { free(line); has_nuls = (linelen != strlen(line)); goto process_headers; } } while /* we may need to grab RFC822 continuations */ ((ch = SockPeek(sock)) == ' ' || ch == '\t'); /* write the message size dots */ if ((outlevel > O_SILENT && outlevel < O_VERBOSE) && linelen > 0) { sizeticker += linelen; while (sizeticker >= SIZETICKER) { error_build("."); sizeticker -= SIZETICKER; } } /* we see an ordinary (non-header, non-message-delimiter line */ has_nuls = (linelen != strlen(line)); /* * 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 (protocol->port != 109) #endif /* POP2_ENABLE */ if (num == 1 && !strncasecmp(line, "X-IMAP:", 7)) { free(line); free(headers); return(PS_RETAINED); } /* * This code prevents fetchmail from becoming an accessory after * the fact to upstream sendmails with the `E' option on. This * can result in an escaped Unix From_ 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 From_ line in headers. These aren't RFC822 * so our conscience is clear... */ if (!strncasecmp(line, ">From ", 6)) { free(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(*cp)) cp++; if (!*cp || ctl->dropstatus) { free(line); continue; } } } if (ctl->rewrite) line = reply_hack(line, ctl->server.truename); /* * 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 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. */ if (!strncasecmp("Return-Path:", line, 12)) { strcpy(return_path, nxtaddr(line)); if (!ctl->mda) { free(line); continue; } } if (!headers) { oldlen = strlen(line); headers = xmalloc(oldlen + 1); (void) strcpy(headers, line); free(line); line = headers; } else { int newlen; newlen = oldlen + strlen(line); headers = (char *) realloc(headers, newlen + 1); if (headers == NULL) { free(line); return(PS_IOERR); } strcpy(headers + oldlen, line); free(line); line = headers + oldlen; oldlen = newlen; } if (!strncasecmp("From:", line, 5)) from_offs = (line - headers); else if (!strncasecmp("Reply-To:", line, 9)) reply_to_offs = (line - headers); else if (!strncasecmp("Resent-From:", line, 12)) resent_from_offs = (line - headers); else if (!strncasecmp("Apparently-From:", line, 16)) app_from_offs = (line - headers); else if (!strncasecmp("Sender:", line, 7)) sender_offs = (line - headers); else if (!strncasecmp("Resent_Sender:", line, 14)) resent_sender_offs = (line - headers); else if (!strncasecmp("Content-Transfer-Encoding:", line, 26)) ctt_offs = (line - headers); else if (!strncasecmp("Message-Id:", buf, 11 )) { if( ctl->server.uidl ) { char id[IDLEN+1]; /* prevent stack overflows */ buf[IDLEN+12] = 0; sscanf( buf+12, "%s", id); if( !str_find( &ctl->newsaved, num ) ) save_str(&ctl->newsaved, num, id ); } } else if (!MULTIDROP(ctl)) continue; else 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 - 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 - 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 - headers); } } else if (!received_for && !strncasecmp("Received:", line, 9)) { if (skipcount++ != ctl->server.envskip) continue; received_for = parse_received(ctl, line); } } } process_headers: /* * We want to detect this early in case there are so few headers that the * dispatch logic barfs. */ if (!headers_ok) { if (outlevel > O_SILENT) error(0,0,"message delimiter found while scanning headers"); } /* * 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 (headers == (char *)NULL) { #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "From: \r\nTo: %s@localhost\r\nSubject: Headerless mail from %s's mailbox on %s\r\n", fetchmailhost, user, ctl->remotename, ctl->server.truename); 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. */ /* * 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 wich is the most probable real sender * respectively. *** 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:") wich is less anoying. This is * true for most mailing list packages. */ if( !return_path[0] ){ char *ap = NULL; if (resent_sender_offs >= 0 && (ap = nxtaddr(headers + resent_sender_offs))); else if (sender_offs >= 0 && (ap = nxtaddr(headers + sender_offs))); else if (resent_from_offs >= 0 && (ap = nxtaddr(headers + resent_from_offs))); else if (from_offs >= 0 && (ap = nxtaddr(headers + from_offs))); else if (reply_to_offs >= 0 && (ap = nxtaddr(headers + reply_to_offs))); else if (app_from_offs >= 0 && (ap = nxtaddr(headers + app_from_offs))); if (ap) strcpy( return_path, ap ); } /* cons up a list of local recipients */ xmit_names = (struct idlist *)NULL; bad_addresses = good_addresses = accept_count = reject_count = 0; /* is this a multidrop box? */ if (MULTIDROP(ctl)) { if (env_offs > -1) /* We have the actual envelope addressee */ find_server_names(headers + env_offs, ctl, &xmit_names); 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, &xmit_names); 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" adresses. */ 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(headers+to_addrchain->offset, ctl, &xmit_names); nextptr = to_addrchain->next; free(to_addrchain); to_addrchain = nextptr; } } if (!accept_count) { no_local_matches = TRUE; save_str(&xmit_names, XMIT_ACCEPT, user); if (outlevel == O_VERBOSE) error(0, 0, "no local matches, forwarding to %s", user); } } else /* it's a single-drop box, use first localname */ save_str(&xmit_names, XMIT_ACCEPT, ctl->localnames->id); /* * 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_VERBOSE) error(0,0, "forwarding and deletion suppressed due to DNS errors"); free(headers); free_str_list(&xmit_names); return(PS_TRANSIENT); } else if (ctl->mda) /* we have a declared MDA */ { int length = 0; char *names, *before, *after; for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ACCEPT) good_addresses++; destaddr = "localhost"; length = strlen(ctl->mda) + 1; before = xstrdup(ctl->mda); /* sub user addresses for %T (or %s for backward compatibility) */ cp = (char *)NULL; if (strstr(before, "%s") || (cp = strstr(before, "%T"))) { char *sp; if (cp && cp[1] == 'T') cp[1] = 's'; /* \177 had better be out-of-band for MDA commands */ for (sp = before; *sp; sp++) if (*sp == '%' && sp[1] != 's' && sp[1] != 'T') *sp = '\177'; /* * We go through this in order to be able to handle very * long lists of users and (re)implement %s. */ for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ACCEPT) length += (strlen(idp->id) + 1); names = (char *)xmalloc(++length); names[0] = '\0'; for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ACCEPT) { strcat(names, idp->id); strcat(names, " "); } after = (char *)xmalloc(length); #ifdef SNPRINTF snprintf(after, length, before, names); #else sprintf(after, before, names); #endif /* SNPRINTF */ free(names); free(before); before = after; for (sp = before; *sp; sp++) if (*sp == '\177') *sp = '%'; } /* substitute From address for %F */ if ((cp = strstr(before, "%F"))) { char *from = return_path; char *sp; /* \177 had better be out-of-band for MDA commands */ for (sp = before; *sp; sp++) if (*sp == '%' && sp[1] != 'F') *sp = '\177'; length += strlen(from); after = (char *)xmalloc(length); cp[1] = 's'; #ifdef SNPRINTF snprintf(after, length, before, from); #else sprintf(after, before, from); #endif /* SNPRINTF */ free(before); before = after; for (sp = before; *sp; sp++) if (*sp == '\177') *sp = '%'; } if (outlevel == O_VERBOSE) error(0, 0, "about to deliver with: %s", before); #ifdef HAVE_SETEUID /* * Arrange to run with user's permissions if we're root. * This will initialize the ownership of any files the * MDA creates properly. (The seteuid call is available * under all BSDs and Linux) */ seteuid(ctl->uid); #endif /* HAVE_SETEUID */ sinkfp = popen(before, "w"); free(before); #ifdef HAVE_SETEUID /* this will fail quietly if we didn't start as root */ seteuid(0); #endif /* HAVE_SETEUID */ if (!sinkfp) { error(0, 0, "MDA open failed"); free(headers); free_str_list(&xmit_names); return(PS_IOERR); } sigchld = signal(SIGCHLD, SIG_DFL); } else { char *ap, *ctt, options[MSGBUFSIZE], addr[128]; /* build a connection to the SMTP listener */ if ((smtp_open(ctl) == -1)) { error(0, errno, "SMTP connect to %s failed", ctl->smtphost ? ctl->smtphost : "localhost"); free(headers); free_str_list(&xmit_names); return(PS_SMTP); } /* * Compute ESMTP options. It's a kluge to use nxtaddr() * here because the contents of the Content-Transfer-Encoding * headers isn't semantically an address. But it has the * desired tokenizing effect. */ options[0] = '\0'; if (ctl->server.esmtp_options & ESMTP_8BITMIME) if (ctl->pass8bits) strcpy(options, " BODY=8BITMIME"); else if ((ctt_offs >= 0) && (ctt = nxtaddr(headers + ctt_offs))) { if (!strcasecmp(ctt,"7BIT")) strcpy(options, " BODY=7BIT"); else if (!strcasecmp(ctt,"8BIT")) strcpy(options, " BODY=8BITMIME"); } if ((ctl->server.esmtp_options & ESMTP_SIZE) && reallen > 0) sprintf(options + strlen(options), " SIZE=%ld", reallen); /* * Try to get the SMTP listener to take the Return-Path * address as MAIL FROM . If it won't, fall back on the * calling-user ID. This won't affect replies, which use the * header From address anyway. * * RFC 1123 requires that the domain name part of the * MAIL FROM address be "canonicalized", that is a * FQDN or MX but not a CNAME. We'll assume the From * header is already in this form here (it certainly * is if rewrite is on). RFC 1123 is silent on whether * a nonexistent hostname part is considered canonical. * * This is a potential problem if the MTAs further upstream * didn't pass canonicalized From/Return-Path lines, *and* the * local SMTP listener insists on them. */ ap = (return_path[0]) ? return_path : user; if (SMTP_from(ctl->smtp_socket, ap, options) != SM_OK) { int smtperr = atoi(smtp_response); if (smtperr == ctl->antispam) { /* * SMTP listener explicitly refuses to deliver mail * coming from this address, probably due to an * anti-spam domain exclusion. Respect this. Don't * try to ship the message, and don't prevent it from * being deleted. Typical values. * * 571 = sendmail's "unsolicited email refused" * 501 = exim's old antispam response * 550 = exim's new antispam response (temporary) */ free(headers); free_str_list(&xmit_names); return(PS_REFUSED); } /* * Suppress error message only if the response specifically * meant `excluded for policy reasons'. We *should* see * an error when the return code is less specific. */ if (smtperr >= 400) error(0, -1, "SMTP error: %s", smtp_response); switch (smtperr) { case 452: /* insufficient system storage */ /* * Temporary out-of-queue-space condition on the * ESMTP server. Don't try to ship the message, * and suppress deletion so it can be retried on * a future retrieval cycle. */ SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */ free(headers); free_str_list(&xmit_names); return(PS_TRANSIENT); case 552: /* message exceeds fixed maximum message size */ /* * Permanent no-go condition on the * ESMTP server. Don't try to ship the message, * and allow it to be deleted. */ SMTP_rset(ctl->smtp_socket); /* required by RFC1870 */ free(headers); free_str_list(&xmit_names); return(PS_REFUSED); default: /* retry with invoking user's address */ if (SMTP_from(ctl->smtp_socket, user, options) != SM_OK) { error(0, -1, "SMTP error: %s", smtp_response); free(headers); free_str_list(&xmit_names); return(PS_SMTP); /* should never happen */ } } } /* * Now list the recipient addressees * * RFC 1123 requires that the domain name part of the * RCPT TO address be "canonicalized", that is a FQDN * or MX but not a CNAME. Some listeners (like exim) * enforce this. */ destaddr = ctl->smtpaddress ? ctl->smtpaddress : ( ctl->smtphost ? ctl->smtphost : "localhost"); for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ACCEPT) { if (strchr(idp->id, '@')) strcpy(addr, idp->id); else #ifdef HAVE_SNPRINTF snprintf(addr, sizeof(addr)-1, "%s@%s", idp->id, destaddr); #else sprintf(addr, "%s@%s", idp->id, destaddr); #endif /* HAVE_SNPRINTF */ if (SMTP_rcpt(ctl->smtp_socket, addr) == SM_OK) good_addresses++; else { bad_addresses++; idp->val.num = XMIT_ANTISPAM; error(0, 0, "SMTP listener doesn't like recipient address `%s'", addr); } } if (!good_addresses) { #ifdef HAVE_SNPRINTF snprintf(addr, sizeof(addr)-1, "%s@%s", user, destaddr); #else sprintf(addr, "%s@%s", user, destaddr); #endif /* HAVE_SNPRINTF */ if (SMTP_rcpt(ctl->smtp_socket, addr) != SM_OK) { error(0, 0, "can't even send to calling user!"); free(headers); free_str_list(&xmit_names); return(PS_SMTP); } } /* tell it we're ready to send data */ SMTP_data(ctl->smtp_socket); } n = 0; /* * Some server/sendmail combinations cause problems when our * synthetic Received line is before the From header. Cope * with this... */ if ((rcv = strstr(headers, "Received:")) == (char *)NULL) rcv = headers; if (rcv > headers) { *rcv = '\0'; n = stuffline(ctl, headers); *rcv = 'R'; } if (!use_invisible && n != -1) { /* utter any per-message Received information we need here */ sprintf(buf, "Received: from %s\n", ctl->server.truename); n = stuffline(ctl, buf); if (n != -1) { /* * We used to include ctl->remotename in this log line, * but this can be secure information that would be bad * to reveal. */ sprintf(buf, "\tby %s (fetchmail-%s %s)\n", fetchmailhost, RELEASE_ID, protocol->name); n = stuffline(ctl, buf); if (n != -1) { time_t now; buf[0] = '\t'; if (good_addresses == 0) { sprintf(buf+1, "for <%s@%s> (by default); ", user, destaddr); } else if (good_addresses == 1) { for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ACCEPT) break; /* only report first address */ if (strchr(idp->id, '@')) sprintf(buf+1, "for <%s>", idp->id); else sprintf(buf+1, "for <%s/%s>", idp->id, destaddr); sprintf(buf+strlen(buf), " (%s); ", MULTIDROP(ctl) ? "multi-drop" : "single-drop"); } else buf[1] = '\0'; time(&now); #ifdef HAVE_STRFTIME /* * Conform to RFC822. This is typically going to emit * a three-letter timezone for %Z, which is going to * be marked "obsolete syntax" in 822bis. Note that we * generate a 4-digit year here. */ strftime(buf + strlen(buf), sizeof(buf) - strlen(buf), "%a, %d %b %Y %H:%M:%S %Z\n", localtime(&now)); #else /* * This is really just a portability fallback, as the * date format ctime(3) emits is not RFC822 * conformant. */ strcat(buf, ctime(&now)); #endif /* HAVE_STRFTIME */ n = stuffline(ctl, buf); } } } if (n != -1) n = stuffline(ctl, rcv); /* ship out rest of headers */ if (n == -1) { error(0, errno, "writing RFC822 headers"); if (ctl->mda) { if (sinkfp) pclose(sinkfp); signal(SIGCHLD, sigchld); } free(headers); free_str_list(&xmit_names); return(PS_IOERR); } else if (outlevel == O_VERBOSE) fputs("#", stderr); /* 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, "no recipient addresses matched declared local names"); else { for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_REJECT) break; sprintf(errhd+strlen(errhd), "recipient address %s didn't match any local name", idp->id); } } if (has_nuls) { if (errhd[sizeof("X-Fetchmail-Warning: ")]) strcat(errhd, "; "); strcat(errhd, "message has embedded NULs"); } if (bad_addresses) { if (errhd[sizeof("X-Fetchmail-Warning: ")]) strcat(errhd, "; "); strcat(errhd, "SMTP listener rejected local recipient addresses: "); errlen = strlen(errhd); for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ANTISPAM) errlen += strlen(idp->id) + 2; errmsg = alloca(errlen+3); (void) strcpy(errmsg, errhd); for (idp = xmit_names; idp; idp = idp->next) if (idp->val.num == XMIT_ANTISPAM) { strcat(errmsg, idp->id); if (idp->next) strcat(errmsg, ", "); } } strcat(errmsg, "\n"); /* ship out the error line */ if (sinkfp) stuffline(ctl, errmsg); } /* issue the delimiter line */ cp = buf; *cp++ = '\r'; *cp++ = '\n'; *cp++ = '\0'; stuffline(ctl, buf); free(headers); free_str_list(&xmit_names); return(headers_ok ? PS_SUCCESS : PS_TRUNCATED); } static int readbody(sock, ctl, forward, len) /* read and dispose of a message body presented on sock */ struct query *ctl; /* query control record */ int sock; /* to which the server is connected */ int len; /* length of message */ flag forward; /* TRUE to forward */ { int linelen; char buf[MSGBUFSIZE+1]; /* pass through the text lines */ while (protocol->delimited || len > 0) { if ((linelen = SockRead(sock, buf, sizeof(buf)-1)) == -1) { if (ctl->mda) { if (sinkfp) pclose(sinkfp); signal(SIGCHLD, sigchld); } return(PS_SOCKET); } set_timeout(ctl->server.timeout); /* write the message size dots */ if (linelen > 0) { sizeticker += linelen; while (sizeticker >= SIZETICKER) { if (outlevel > O_SILENT) error_build("."); sizeticker -= SIZETICKER; } } len -= linelen; /* check for end of message */ if (protocol->delimited && *buf == '.') if (buf[1] == '\r' && buf[2] == '\n' && buf[3] == '\0') break; else if (buf[1] == '\n' && buf[2] == '\0') break; else msglen--; /* subtract the size of the dot escape */ msglen += linelen; /* ship out the text line */ if (forward) { int n = stuffline(ctl, buf); if (n < 0) { error(0, errno, "writing message text"); if (ctl->mda) { if (sinkfp) pclose(sinkfp); signal(SIGCHLD, sigchld); } return(PS_IOERR); } else if (outlevel == O_VERBOSE) fputc('*', stderr); } } return(PS_SUCCESS); } #ifdef KERBEROS_V4 int kerberos_auth (socket, canonical) /* authenticate to the server host using Kerberos V4 */ int socket; /* socket to server host */ #ifdef __FreeBSD__ char *canonical; /* server name */ #else const char *canonical; /* server name */ #endif { char * host_primary; KTEXT ticket; MSG_DAT msg_data; CREDENTIALS cred; Key_schedule schedule; int rem; ticket = ((KTEXT) (malloc (sizeof (KTEXT_ST)))); rem = (krb_sendauth (0L, socket, ticket, "pop", canonical, ((char *) (krb_realmofhost (canonical))), ((unsigned long) 0), (&msg_data), (&cred), (schedule), ((struct sockaddr_in *) 0), ((struct sockaddr_in *) 0), "KPOPV0.1")); free (ticket); if (rem != KSUCCESS) { error(0, -1, "kerberos error %s", (krb_get_err_text (rem))); return (PS_AUTHFAIL); } return (0); } #endif /* KERBEROS_V4 */ #ifdef KERBEROS_V5 int kerberos5_auth(socket, canonical) /* authernticate to the server host using Kerberos V5 */ int socket; /* socket to server host */ const char *canonical; /* server name */ { krb5_error_code retval; krb5_context context; krb5_ccache ccdef; krb5_principal client = NULL, server = NULL; krb5_error *err_ret = NULL; krb5_auth_context auth_context = NULL; krb5_init_context(&context); krb5_init_ets(context); krb5_auth_con_init(context, &auth_context); if (retval = krb5_cc_default(context, &ccdef)) { error(0, 0, "krb5_cc_default: %s", error_message(retval)); return(PS_ERROR); } if (retval = krb5_cc_get_principal(context, ccdef, &client)) { error(0, 0, "krb5_cc_get_principal: %s", error_message(retval)); return(PS_ERROR); } if (retval = krb5_sname_to_principal(context, canonical, "pop", KRB5_NT_UNKNOWN, &server)) { error(0, 0, "krb5_sname_to_principal: %s", error_message(retval)); return(PS_ERROR); } retval = krb5_sendauth(context, &auth_context, (krb5_pointer) &socket, "KPOPV1.0", client, server, AP_OPTS_MUTUAL_REQUIRED, NULL, /* no data to checksum */ 0, /* no creds, use ccache instead */ ccdef, &err_ret, 0, NULL); /* don't need reply */ krb5_free_principal(context, server); krb5_free_principal(context, client); krb5_auth_con_free(context, auth_context); if (retval) { if (err_ret && err_ret->text.length) { error(0, 0, "krb5_sendauth: %s [server says '%*s'] ", error_message(retval), err_ret->text.length, err_ret->text.data); krb5_free_error(context, err_ret); } else error(0, 0, "krb5_sendauth: %s", error_message(retval)); return(PS_ERROR); } return 0; } #endif /* KERBEROS_V5 */ int do_protocol(ctl, proto) /* retrieve messages from server using given protocol method table */ struct query *ctl; /* parsed options with merged-in defaults */ const struct method *proto; /* protocol method table */ { int ok, js, sock = -1; char *msg; void (*sigsave)(); #ifndef KERBEROS_V4 if (ctl->server.preauthenticate == A_KERBEROS_V4) { error(0, -1, "Kerberos V4 support not linked."); return(PS_ERROR); } #endif /* KERBEROS_V4 */ #ifndef KERBEROS_V5 if (ctl->server.preauthenticate == A_KERBEROS_V5) { error(0, -1, "Kerberos V5 support not linked."); return(PS_ERROR); } #endif /* KERBEROS_V5 */ /* lacking methods, there are some options that may fail */ if (!proto->is_old) { /* check for unsupported options */ if (ctl->flush) { error(0, 0, "Option --flush is not supported with %s", proto->name); return(PS_SYNTAX); } else if (ctl->fetchall) { error(0, 0, "Option --all is not supported with %s", proto->name); return(PS_SYNTAX); } } if (!proto->getsizes && NUM_SPECIFIED(ctl->limit)) { error(0, 0, "Option --limit is not supported with %s", proto->name); return(PS_SYNTAX); } protocol = proto; pass = 0; tagnum = 0; tag[0] = '\0'; /* nuke any tag hanging out from previous query */ ok = 0; /* set up the server-nonresponse timeout */ sigsave = signal(SIGALRM, timeout_handler); set_timeout(mytimeout = ctl->server.timeout); if ((js = setjmp(restart)) == 1) { if (phase == SERVER_WAIT) error(0, 0, "timeout after %d seconds waiting for server %s.", ctl->server.timeout, ctl->server.pollname); else if (phase == FORWARDING_WAIT) error(0, 0, "timeout after %d seconds waiting for %s.", ctl->server.timeout, ctl->mda ? "MDA" : "SMTP"); else error(0, 0, "timeout after %d seconds.", ctl->server.timeout); if (ctl->smtp_socket != -1) close(ctl->smtp_socket); if (sock != -1) close(sock); if (sinkfp) pclose(sinkfp); ok = PS_ERROR; } else { char buf [POPBUFSIZE+1], *realhost; int *msgsizes, len, num, count, new, deletions = 0; #if INET6 int fetches, dispatches; #else /* INET6 */ int port, fetches, dispatches; #endif /* INET6 */ struct idlist *idp; /* execute pre-initialization command, if any */ if (ctl->preconnect && (ok = system(ctl->preconnect))) { sprintf(buf, "pre-connection command failed with status %d", ok); error(0, 0, buf); ok = PS_SYNTAX; goto closeUp; } /* open a socket to the mail server */ #if !INET6 port = ctl->server.port ? ctl->server.port : protocol->port; #endif /* !INET6 */ realhost = ctl->server.via ? ctl->server.via : ctl->server.pollname; #if INET6 if ((sock = SockOpen(realhost, ctl->server.service ? ctl->server.service : protocol->service, ctl->server.netsec)) == -1) #else /* INET6 */ if ((sock = SockOpen(realhost, port, NULL)) == -1) #endif /* INET6 */ { #if !INET6 #ifndef EHOSTUNREACH #define EHOSTUNREACH (-1) #endif if (outlevel == O_VERBOSE || errno != EHOSTUNREACH) { error_build("fetchmail: %s connection to %s failed: ", protocol->name, ctl->server.pollname); #ifdef HAVE_RES_SEARCH if (h_errno == HOST_NOT_FOUND) error_complete(0, 0, "host is unknown"); else if (h_errno == NO_ADDRESS) error_complete(0, 0, "name is valid but has no IP address"); else if (h_errno == NO_RECOVERY) error_complete(0, 0, "unrecoverable name server error"); else if (h_errno == TRY_AGAIN) error_complete(0, 0, "temporary name server error"); else if (h_errno) error_complete(0, 0, "unknown DNS error %d", h_errno); else #endif /* HAVE_RES_SEARCH */ error_complete(0, errno, "local error"); } #endif /* INET6 */ ok = PS_SOCKET; goto closeUp; } #ifdef KERBEROS_V4 if (ctl->server.preauthenticate == A_KERBEROS_V4) { ok = kerberos_auth(sock, ctl->server.truename); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); } #endif /* KERBEROS_V4 */ #ifdef KERBEROS_V5 if (ctl->server.preauthenticate == A_KERBEROS_V5) { ok = kerberos5_auth(sock, ctl->server.truename); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); } #endif /* KERBEROS_V5 */ /* accept greeting message from mail server */ ok = (protocol->parse_response)(sock, buf); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); /* try to get authorized to fetch mail */ if (protocol->getauth) { shroud = ctl->password; ok = (protocol->getauth)(sock, ctl, buf); shroud = (char *)NULL; if (ok != 0) { if (ok == PS_LOCKBUSY) error(0, -1, "Lock-busy error on %s@%s", ctl->remotename, ctl->server.truename); else { if (ok == PS_ERROR) ok = PS_AUTHFAIL; error(0, -1, "Authorization failure on %s@%s", ctl->remotename, ctl->server.truename); } goto cleanUp; } set_timeout(ctl->server.timeout); } ctl->errcount = fetches = 0; /* now iterate over each folder selected */ for (idp = ctl->mailboxes; idp; idp = idp->next) { pass = 0; do { dispatches = 0; ++pass; if (outlevel >= O_VERBOSE) if (idp->id) error(0, 0, "selecting or re-polling folder %s", idp->id); else error(0, 0, "selecting or re-polling default folder"); /* compute # of messages and number of new messages waiting */ ok = (protocol->getrange)(sock, ctl, idp->id, &count, &new); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); /* show user how many messages we downloaded */ if (idp->id) (void) sprintf(buf, "%s at %s (folder %s)", ctl->remotename, ctl->server.truename, idp->id); else (void) sprintf(buf, "%s at %s", ctl->remotename, ctl->server.truename); if (outlevel > O_SILENT) if (count == -1) /* only used for ETRN */ error(0, 0, "Polling %s", ctl->server.truename); else if (count != 0) { if (new != -1 && (count - new) > 0) error(0, 0, "%d message%s (%d seen) for %s.", count, count > 1 ? "s" : "", count-new, buf); else error(0, 0, "%d message%s for %s.", count, count > 1 ? "s" : "", buf); } else { /* these are pointless in normal daemon mode */ if (pass == 1 && (poll_interval == 0 || outlevel == O_VERBOSE)) error(0, 0, "No mail for %s", buf); } /* very important, this is where we leave the do loop */ if (count == 0) break; if (check_only) { if (new == -1 || ctl->fetchall) new = count; ok = ((new > 0) ? PS_SUCCESS : PS_NOMAIL); goto cleanUp; } else if (count > 0) { flag force_retrieval; /* * What forces this code is that in POP3 and * IMAP2BIS you can't fetch a message without * having it marked `seen'. In IMAP4, on the * other hand, you can (peek_capable is set to * convey this). * * The result of being unable to peek is that if there's * any kind of transient error (DNS lookup failure, or * sendmail refusing delivery due to process-table limits) * the message will be marked "seen" on the server without * having been delivered. This is not a big problem if * fetchmail is running in foreground, because the user * will see a "skipped" message when it next runs and get * clued in. * * But in daemon mode this leads to the message * being silently ignored forever. This is not * acceptable. * * We compensate for this by checking the error * count from the previous pass and forcing all * messages to be considered new if it's nonzero. */ force_retrieval = !peek_capable && (ctl->errcount > 0); /* * We need the size of each message before it's * loaded in order to pass via the ESMTP SIZE * option. If the protocol has a getsizes method, * we presume this means it doesn't get reliable * sizes from message fetch responses. */ if (proto->getsizes) { int i; msgsizes = (int *)alloca(sizeof(int) * count); for (i = 0; i < count; i++) msgsizes[i] = -1; ok = (proto->getsizes)(sock, count, msgsizes); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); } /* read, forward, and delete messages */ for (num = 1; num <= count; num++) { flag toolarge = NUM_NONZERO(ctl->limit) && msgsizes && (msgsizes[num-1] > ctl->limit); flag fetch_it = !toolarge && (ctl->fetchall || force_retrieval || !(protocol->is_old && (protocol->is_old)(sock,ctl,num))); flag suppress_delete = FALSE; flag suppress_forward = FALSE; flag suppress_readbody = FALSE; flag retained = FALSE; /* * This check copes with Post Office/NT's * annoying habit of randomly prepending bogus * LIST items of length -1. Patrick Audley * tells us: LIST shows a * size of -1, RETR and TOP return "-ERR * System error - couldn't open message", and * DELE succeeds but doesn't actually delete * the message. */ if (msgsizes && msgsizes[num-1] == -1) { if (outlevel >= O_VERBOSE) error(0, 0, "Skipping message %d, length -1", num - 1); continue; } /* we may want to reject this message if it's old */ if (!fetch_it) { if (outlevel > O_SILENT) { error_build("skipping message %d", num); if (toolarge) error_build(" (oversized, %d bytes)", msgsizes[num-1]); } } else { flag wholesize = !protocol->fetch_body; /* request a message */ ok = (protocol->fetch_headers)(sock,ctl,num, &len); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); /* -1 means we didn't see a size in the response */ if (len == -1 && msgsizes) { len = msgsizes[num - 1]; wholesize = TRUE; } if (outlevel > O_SILENT) { error_build("reading message %d of %d", num,count); if (len > 0) error_build(" (%d %sbytes)", len, wholesize ? "" : "header "); if (outlevel == O_VERBOSE) error_complete(0, 0, ""); else error_build(" "); } /* later we'll test for this before closing */ sinkfp = (FILE *)NULL; /* * Read the message headers and ship them to the * output sink. */ ok = readheaders(sock, len, msgsizes[num-1], ctl, num); if (ok == PS_RETAINED) suppress_forward = retained = TRUE; else if (ok == PS_TRANSIENT) suppress_delete = suppress_forward = TRUE; else if (ok == PS_REFUSED) suppress_forward = TRUE; else if (ok == PS_TRUNCATED) suppress_readbody = TRUE; else if (ok) goto cleanUp; set_timeout(ctl->server.timeout); /* * If we're using IMAP4 or something else that * can fetch headers separately from bodies, * it's time to request the body now. This * fetch may be skipped if we got an anti-spam * or other PS_REFUSED error response during * read_headers. */ if (protocol->fetch_body && !suppress_readbody) { if (outlevel == O_VERBOSE) fputc('\n', stderr); if ((ok = (protocol->trail)(sock, ctl, num))) goto cleanUp; set_timeout(ctl->server.timeout); len = 0; if (!suppress_forward) { if ((ok=(protocol->fetch_body)(sock,ctl,num,&len))) goto cleanUp; if (outlevel > O_SILENT && !wholesize) error_build(" (%d body bytes) ", len); set_timeout(ctl->server.timeout); } } /* process the body now */ if (len > 0) { if (suppress_readbody) { /* When readheaders returns PS_TRUNCATED, the body (which has no content has already been read by readheaders, so we say readbody returned PS_SUCCESS */ ok = PS_SUCCESS; } else { ok = readbody(sock, ctl, !suppress_forward, len); } if (ok == PS_TRANSIENT) suppress_delete = suppress_forward = TRUE; else if (ok) goto cleanUp; set_timeout(ctl->server.timeout); /* tell server we got it OK and resynchronize */ if (protocol->trail) { if (outlevel == O_VERBOSE) fputc('\n', stderr); ok = (protocol->trail)(sock, ctl, num); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); } } /* count # messages forwarded on this pass */ if (!suppress_forward) dispatches++; /* * Check to see if the numbers matched? * * Yes, some servers foo this up horribly. * All IMAP servers seem to get it right, and * so does Eudora QPOP at least in 2.xx * versions. * * Microsoft Exchange gets it completely * wrong, reporting compressed rather than * actual sizes (so the actual length of * message is longer than the reported size). * Another fine example of Microsoft brain death! * * Some older POP servers, like the old UCB * POP server and the pre-QPOP QUALCOMM * versions, report a longer size in the LIST * response than actually gets shipped up. * It's unclear what is going on here, as the * QUALCOMM server (at least) seems to be * reporting the on-disk size correctly. */ if (msgsizes && msglen != msgsizes[num-1]) { if (outlevel >= O_VERBOSE) error(0, 0, "message %d was not the expected length (%d != %d)", num, msglen, msgsizes[num-1]); } /* end-of-message processing starts here */ if (ctl->mda) { int rc; /* close the delivery pipe, we'll reopen before next message */ if (sinkfp) rc = pclose(sinkfp); else rc = 0; signal(SIGCHLD, sigchld); if (rc) { error(0, -1, "MDA exited abnormally or returned nonzero status"); goto cleanUp; } } else if (!suppress_forward) { /* write message terminator */ if (SMTP_eom(ctl->smtp_socket) != SM_OK) { error(0, -1, "SMTP listener refused delivery"); ctl->errcount++; suppress_delete = TRUE; } } fetches++; } /* * At this point in flow of control, either * we've bombed on a protocol error or had * delivery refused by the SMTP server * (unlikely -- I've never seen it) or we've * seen `accepted for delivery' and the * message is shipped. It's safe to mark the * message seen and delete it on the server * now. */ /* tell the UID code we've seen this */ if (ctl->newsaved) { struct idlist *sdp; for (sdp = ctl->newsaved; sdp; sdp = sdp->next) if (sdp->val.num == num) MARK_SEEN(sdp->val.num); } /* maybe we delete this message now? */ if (retained) { if (outlevel > O_SILENT) error_complete(0, 0, " retained"); } else if (protocol->delete && !suppress_delete && (fetch_it ? !ctl->keep : ctl->flush)) { deletions++; if (outlevel > O_SILENT) error_complete(0, 0, " flushed"); ok = (protocol->delete)(sock, ctl, num); if (ok != 0) goto cleanUp; set_timeout(ctl->server.timeout); #ifdef POP3_ENABLE delete_str(&ctl->newsaved, num); #endif /* POP3_ENABLE */ } else if (outlevel > O_SILENT) error_complete(0, 0, " not flushed"); /* perhaps this as many as we're ready to handle */ if (NUM_NONZERO(ctl->fetchlimit) && ctl->fetchlimit <= fetches) goto no_error; } } } while /* * Only re-poll if we had some actual forwards, allowed * deletions and had no errors. * Otherwise it is far too easy to get into infinite loops. */ (dispatches && protocol->retry && !ctl->keep && !ctl->errcount); } no_error: set_timeout(ctl->server.timeout); ok = (protocol->logout_cmd)(sock, ctl); /* * Hmmmm...arguably this would be incorrect if we had fetches but * no dispatches (due to oversized messages, etc.) */ if (ok == 0) ok = (fetches > 0) ? PS_SUCCESS : PS_NOMAIL; set_timeout(0); close(sock); goto closeUp; cleanUp: set_timeout(ctl->server.timeout); if (ok != 0 && ok != PS_SOCKET) (protocol->logout_cmd)(sock, ctl); set_timeout(0); close(sock); } msg = (char *)NULL; /* sacrifice to -Wall */ switch (ok) { case PS_SOCKET: msg = "socket"; break; case PS_AUTHFAIL: msg = "authorization"; break; case PS_SYNTAX: msg = "missing or bad RFC822 header"; break; case PS_IOERR: msg = "MDA"; break; case PS_ERROR: msg = "client/server synchronization"; break; case PS_PROTOCOL: msg = "client/server protocol"; break; case PS_LOCKBUSY: msg = "lock busy on server"; break; case PS_SMTP: msg = "SMTP transaction"; break; case PS_DNS: msg = "DNS lookup"; break; case PS_UNDEFINED: error(0, 0, "undefined"); break; } if (ok==PS_SOCKET || ok==PS_AUTHFAIL || ok==PS_SYNTAX || ok==PS_IOERR || ok==PS_ERROR || ok==PS_PROTOCOL || ok==PS_LOCKBUSY || ok==PS_SMTP) error(0,-1, "%s error while fetching from %s", msg, ctl->server.pollname); closeUp: /* execute post-initialization command, if any */ if (ctl->postconnect && (ok = system(ctl->postconnect))) { char buf[80]; sprintf(buf, "post-connection command failed with status %d", ok); error(0, 0, buf); if (ok == PS_SUCCESS) ok = PS_SYNTAX; } signal(SIGALRM, sigsave); return(ok); } #if defined(HAVE_STDARG_H) void gen_send(int sock, const char *fmt, ... ) /* assemble command in printf(3) style and send to the server */ #else void gen_send(sock, fmt, va_alist) /* assemble command in printf(3) style and send to the server */ int sock; /* socket to which server is connected */ const char *fmt; /* printf-style format */ va_dcl #endif { char buf [MSGBUFSIZE+1]; va_list ap; if (protocol->tagged) (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), fmt, ap); #else vsprintf(buf + strlen(buf), fmt, ap); #endif va_end(ap); strcat(buf, "\r\n"); SockWrite(sock, buf, strlen(buf)); if (outlevel == O_VERBOSE) { char *cp; if (shroud && shroud[0] && (cp = strstr(buf, shroud))) { char *sp; sp = cp + strlen(shroud); *cp++ = '*'; while (*sp) *cp++ = *sp++; *cp = '\0'; } buf[strlen(buf)-2] = '\0'; error(0, 0, "%s> %s", 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; if (SockRead(sock, buf, size) == -1) { phase = oldphase; return(PS_SOCKET); } else { if (buf[strlen(buf)-1] == '\n') buf[strlen(buf)-1] = '\0'; if (buf[strlen(buf)-1] == '\r') buf[strlen(buf)-1] = '\r'; if (outlevel == O_VERBOSE) error(0, 0, "%s< %s", protocol->name, buf); phase = oldphase; return(PS_SUCCESS); } } #if defined(HAVE_STDARG_H) int gen_transact(int sock, char *fmt, ... ) /* assemble command in printf(3) style, send to server, accept a response */ #else int gen_transact(int sock, fmt, va_alist) /* assemble command in printf(3) style, send to server, accept a response */ int sock; /* socket to which server is connected */ const char *fmt; /* printf-style format */ va_dcl #endif { 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) (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), fmt, ap); #else vsprintf(buf + strlen(buf), fmt, ap); #endif va_end(ap); strcat(buf, "\r\n"); SockWrite(sock, buf, strlen(buf)); if (outlevel == O_VERBOSE) { char *cp; if (shroud && shroud[0] && (cp = strstr(buf, shroud))) { char *sp; sp = cp + strlen(shroud); *cp++ = '*'; while (*sp) *cp++ = *sp++; *cp = '\0'; } buf[strlen(buf)-1] = '\0'; error(0, 0, "%s> %s", protocol->name, buf); } /* we presume this does its own response echoing */ ok = (protocol->parse_response)(sock, buf); set_timeout(mytimeout); phase = oldphase; return(ok); } /* driver.c ends here */