fetchmail - [fork] set imap idle timeout to 600s, some servers don't follow rfc recommendations

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Diffstat (limited to 'po')

0 files changed, 0 insertions, 0 deletions

/* * sink.c -- forwarding/delivery support for fetchmail * * The interface of this module (open_sink(), stuff_line(), close_sink(), * release_sink()) seals off the delivery logic from the protocol machine, * so the latter won't have to care whether it's shipping to an [SL]MTP * listener daemon or an MDA pipe. * * Copyright 1998 by Eric S. Raymond * For license terms, see the file COPYING in this directory. */ #include "config.h" #include <stdio.h> #include <errno.h> #include <string.h> #include <signal.h> #ifdef HAVE_MEMORY_H #include <memory.h> #endif /* HAVE_MEMORY_H */ #if defined(STDC_HEADERS) #include <stdlib.h> #endif #if defined(HAVE_UNISTD_H) #include <unistd.h> #endif #if defined(HAVE_STDARG_H) #include <stdarg.h> #else #include <varargs.h> #endif #include <ctype.h> #include <langinfo.h> #include "fetchmail.h" /* for W* macros after pclose() */ #define _USE_BSD #include <sys/types.h> #include <sys/resource.h> #include <sys/wait.h> #include "socket.h" #include "smtp.h" #include "i18n.h" /* BSD portability hack...I know, this is an ugly place to put it */ #if !defined(SIGCHLD) && defined(SIGCLD) #define SIGCHLD SIGCLD #endif /* makes the open_sink()/close_sink() pair non-reentrant */ static int lmtp_responses; void smtp_close(struct query *ctl, int sayquit) /* close the socket to SMTP server */ { if (ctl->smtp_socket != -1) { if (sayquit) SMTP_quit(ctl->smtp_socket, ctl->smtphostmode); SockClose(ctl->smtp_socket); ctl->smtp_socket = -1; } batchcount = 0; } static void smtp_rset(struct query *ctl) /* reset the mail transaction */ { if (SMTP_rset(ctl->smtp_socket, ctl->smtphostmode) == SM_UNRECOVERABLE) { /* close the bad connection. fetchmail will reconnect for the * next mail */ smtp_close(ctl, 0); } } 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 (last_smtp_ok > 0 && time((time_t *)NULL) - last_smtp_ok > mytimeout) { smtp_close(ctl, 1); last_smtp_ok = 0; } if (NUM_NONZERO(ctl->batchlimit)) { if (batchcount == ctl->batchlimit) smtp_close(ctl, 1); batchcount++; } /* 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 * listeners 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; const char *id_me = run.invisible ? ctl->server.truename : fetchmailhost; int oldphase = phase; char *parsed_host = NULL; 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). */ oldphase = phase; phase = LISTENER_WAIT; set_timeout(ctl->server.timeout); for (idp = ctl->smtphunt; idp; idp = idp->next) { char *cp; char *portnum = SMTP_PORT; ctl->smtphost = idp->id; /* remember last host tried. */ if (ctl->smtphost[0]=='/') { ctl->smtphostmode = LMTP_MODE; xfree(parsed_host); if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1) continue; } else { ctl->smtphostmode = ctl->listener; parsed_host = xstrdup(idp->id); if ((cp = strrchr(parsed_host, '/'))) { *cp++ = 0; if (cp[0]) portnum = cp; } if ((ctl->smtp_socket = SockOpen(parsed_host,portnum, ctl->server.plugout, &ai1)) == -1) { xfree(parsed_host); continue; } } /* return immediately for ODMR */ if (ctl->server.protocol == P_ODMR) { set_timeout(0); phase = oldphase; xfree(parsed_host); return(ctl->smtp_socket); /* success */ } /* first, probe for ESMTP */ if (SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_STARTSMTP) == SM_OK && SMTP_ehlo(ctl->smtp_socket, ctl->smtphostmode, id_me, ctl->server.esmtp_name, ctl->server.esmtp_password, &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. */ smtp_close(ctl, 0); /* if opening for ESMTP failed, try SMTP */ if (ctl->smtphost[0]=='/') { if ((ctl->smtp_socket = UnixOpen(ctl->smtphost))==-1) continue; } else { if ((ctl->smtp_socket = SockOpen(parsed_host,portnum, ctl->server.plugout, &ai1)) == -1) { xfree(parsed_host); continue; } } if (SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_STARTSMTP) == SM_OK && SMTP_helo(ctl->smtp_socket, ctl->smtphostmode, id_me) == SM_OK) break; /* success */ smtp_close(ctl, 0); } set_timeout(0); phase = oldphase; /* * 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. Now that we have the actual hostname, * compute what we should canonicalize with. */ xfree(ctl->destaddr); if (ctl->smtpaddress) ctl->destaddr = xstrdup(ctl->smtpaddress); /* parsed_host is smtphost without the /port */ else if (parsed_host && parsed_host[0] != 0) ctl->destaddr = xstrdup(parsed_host); /* No smtphost is specified or it is a UNIX socket, then use localhost as a domain part. */ else ctl->destaddr = xstrdup("localhost"); xfree(parsed_host); } /* end if (ctl->smtp_socket == -1) */ if (outlevel >= O_DEBUG && ctl->smtp_socket != -1) report(stdout, GT_("forwarding to %s\n"), ctl->smtphost); return(ctl->smtp_socket); } static void sanitize(char *s) /* replace ' by _ */ { char *cp; for (cp = s; (cp = strchr (cp, '\'')); cp++) *cp = '_'; } char *rcpt_address(struct query *ctl, const char *id, int usesmtpname) { static char addr[HOSTLEN+USERNAMELEN+1]; if (strchr(id, '@')) { snprintf(addr, sizeof (addr), "%s", id); } else if (usesmtpname && ctl->smtpname) { snprintf(addr, sizeof (addr), "%s", ctl->smtpname); } else { snprintf(addr, sizeof (addr), "%s@%s", id, ctl->destaddr); } return addr; } static int send_bouncemail(struct query *ctl, struct msgblk *msg, int userclass, char *message /* should have \r\n at the end */, int nerrors, char *errors[]) /* bounce back an error report a la RFC 1892 */ { char daemon_name[15 + HOSTLEN] = "MAILER-DAEMON@"; char boundary[BUFSIZ], *bounce_to; int sock; static char *fqdn_of_host = NULL; const char *md1 = "MAILER-DAEMON", *md2 = "MAILER-DAEMON@"; /* don't bounce in reply to undeliverable bounces */ if (!msg || !msg->return_path[0] || strcmp(msg->return_path, "<>") == 0 || strcasecmp(msg->return_path, md1) == 0 || strncasecmp(msg->return_path, md2, strlen(md2)) == 0) return(TRUE); bounce_to = (run.bouncemail ? msg->return_path : run.postmaster); /* can't just use fetchmailhost here, it might be localhost */ if (fqdn_of_host == NULL) fqdn_of_host = host_fqdn(0); /* can't afford to bail out and lose the NDN here */ strlcat(daemon_name, fqdn_of_host, sizeof(daemon_name)); /* we need only SMTP for this purpose */ /* XXX FIXME: hardcoding localhost is nonsense if smtphost can be * configured */ if ((sock = SockOpen("localhost", SMTP_PORT, NULL, &ai1)) == -1) return(FALSE); if (SMTP_ok(sock, SMTP_MODE, TIMEOUT_STARTSMTP) != SM_OK) { SockClose(sock); return FALSE; } if (SMTP_helo(sock, SMTP_MODE, fetchmailhost) != SM_OK || SMTP_from(sock, SMTP_MODE, "<>", (char *)NULL) != SM_OK || SMTP_rcpt(sock, SMTP_MODE, bounce_to) != SM_OK || SMTP_data(sock, SMTP_MODE) != SM_OK) { SMTP_quit(sock, SMTP_MODE); SockClose(sock); return(FALSE); } /* our first duty is to keep the sacred foo counters turning... */ snprintf(boundary, sizeof(boundary), "foo-mani-padme-hum-%ld-%ld-%ld", (long)getpid(), (long)getppid(), (long)time(NULL)); if (outlevel >= O_VERBOSE) report(stdout, GT_("SMTP: (bounce-message body)\n")); else /* this will usually go to sylog... */ report(stderr, GT_("mail from %s bounced to %s\n"), daemon_name, bounce_to); /* bouncemail headers */ SockPrintf(sock, "Subject: Mail delivery failed: returning message to sender\r\n"); SockPrintf(sock, "From: Mail Delivery System <%s>\r\n", daemon_name); SockPrintf(sock, "To: %s\r\n", bounce_to); SockPrintf(sock, "MIME-Version: 1.0\r\n"); SockPrintf(sock, "Content-Type: multipart/report; report-type=delivery-status;\r\n\tboundary=\"%s\"\r\n", boundary); SockPrintf(sock, "\r\n"); /* RFC1892 part 1 -- human-readable message */ SockPrintf(sock, "--%s\r\n", boundary); SockPrintf(sock,"Content-Type: text/plain\r\n"); SockPrintf(sock, "\r\n"); SockPrintf(sock, "This message was created automatically by mail delivery software.\r\n"); SockPrintf(sock, "\r\n"); SockPrintf(sock, "A message that you sent could not be delivered to one or more of its\r\n"); SockPrintf(sock, "recipients. This is a permanent error.\r\n"); SockPrintf(sock, "\r\n"); SockPrintf(sock, "Reason: %s", message); SockPrintf(sock, "\r\n"); SockPrintf(sock, "The following address(es) failed:\r\n"); if (nerrors) { struct idlist *idp; int nusers; nusers = 0; for (idp = msg->recipients; idp; idp = idp->next) { if (idp->val.status.mark == userclass) { char *error; SockPrintf(sock, "%s\r\n", rcpt_address (ctl, idp->id, 1)); if (nerrors == 1) error = errors[0]; else if (nerrors <= nusers) { SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n"); break; } else error = errors[nusers++]; SockPrintf(sock, " SMTP error: %s\r\n\r\n", error); } } /* RFC1892 part 2 -- machine-readable responses */ SockPrintf(sock, "--%s\r\n", boundary); SockPrintf(sock,"Content-Type: message/delivery-status\r\n"); SockPrintf(sock, "\r\n"); SockPrintf(sock, "Reporting-MTA: dns; %s\r\n", fqdn_of_host); nusers = 0; for (idp = msg->recipients; idp; idp = idp->next) if (idp->val.status.mark == userclass) { char *error; /* Minimum RFC1894 compliance + Diagnostic-Code field */ SockPrintf(sock, "\r\n"); SockPrintf(sock, "Final-Recipient: rfc822; %s\r\n", rcpt_address (ctl, idp->id, 1)); SockPrintf(sock, "Last-Attempt-Date: %s\r\n", rfc822timestamp()); SockPrintf(sock, "Action: failed\r\n"); if (nerrors == 1) /* one error applies to all users */ error = errors[0]; else if (nerrors <= nusers) { SockPrintf(sock, "Internal error: SMTP error count doesn't match number of recipients.\r\n"); break; } else /* errors correspond 1-1 to selected users */ error = errors[nusers++]; if (strlen(error) > 9 && isdigit((unsigned char)error[4]) && error[5] == '.' && isdigit((unsigned char)error[6]) && error[7] == '.' && isdigit((unsigned char)error[8])) /* Enhanced status code available, use it */ SockPrintf(sock, "Status: %5.5s\r\n", &(error[4])); else /* Enhanced status code not available, fake one */ SockPrintf(sock, "Status: %c.0.0\r\n", error[0]); SockPrintf(sock, "Diagnostic-Code: %s\r\n", error); } SockPrintf(sock, "\r\n"); } /* RFC1892 part 3 -- headers of undelivered message */ SockPrintf(sock, "--%s\r\n", boundary); SockPrintf(sock, "Content-Type: text/rfc822-headers\r\n"); SockPrintf(sock, "\r\n"); if (msg->headers) { SockWrite(sock, msg->headers, strlen(msg->headers)); SockPrintf(sock, "\r\n"); } SockPrintf(sock, "--%s--\r\n", boundary); if (SMTP_eom(sock, SMTP_MODE) != SM_OK || SMTP_quit(sock, SMTP_MODE) != SM_OK) { SockClose(sock); return(FALSE); } SockClose(sock); return(TRUE); } static int handle_smtp_report(struct query *ctl, struct msgblk *msg) /* handle SMTP errors based on the content of SMTP_response */ /* returns either PS_REFUSED (to delete message from the server), * or PS_TRANSIENT (keeps the message on the server) */ { int smtperr = atoi(smtp_response); char *responses[1]; struct idlist *walk; int found = 0; responses[0] = xstrdup(smtp_response); #ifdef __UNUSED__ /* * Don't do this! It can really mess you up if, for example, you're * reporting an error with a single RCPT TO address among several; * RSET discards the message body and it doesn't get sent to the * valid recipients. */ smtp_rset(ctl); /* stay on the safe side */ if (outlevel >= O_DEBUG) report(stdout, GT_("Saved error is still %d\n"), smtperr); #endif /* __UNUSED */ /* * Note: send_bouncemail message strings are not made subject * to gettext translation because (a) they're going to be * embedded in a text/plain 7bit part, and (b) they're * going to be associated with listener error-response * messages, which are probably in English (none of the * MTAs I know about are internationalized). */ for( walk = ctl->antispam; walk; walk = walk->next ) if ( walk->val.status.num == smtperr ) { found=1; break; } /* if (str_find(&ctl->antispam, smtperr)) */ if ( found ) { /* * 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. There's no point in bouncing the * email either since most spammers don't put their * real return email address anywhere in the headers * (unless the user insists with the SET SPAMBOUNCE * config option). * * Default values: * * 571 = sendmail's "unsolicited email refused" * 550 = exim's new antispam response (temporary) * 501 = exim's old antispam response * 554 = Postfix antispam response. * */ if (run.spambounce) { char rejmsg[160]; snprintf(rejmsg, sizeof(rejmsg), "spam filter or virus scanner rejected message because:\r\n" "%s\r\n", responses[0]); send_bouncemail(ctl, msg, XMIT_ACCEPT, rejmsg, 1, responses); } free(responses[0]); 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) report(stderr, GT_("%cMTP error: %s\n"), ctl->smtphostmode, responses[0]); switch (smtperr) { 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. */ if (run.bouncemail) send_bouncemail(ctl, msg, XMIT_ACCEPT, "This message was too large (SMTP error 552).\r\n", 1, responses); free(responses[0]); return(PS_REFUSED); case 553: /* invalid sending domain */ /* * These latter days 553 usually means a spammer is trying to * cover his tracks. We never bouncemail on these, because * (a) the return address is invalid by definition, and * (b) we wouldn't want spammers to get confirmation that * this address is live, anyway. */ #ifdef __DONT_FEED_THE_SPAMMERS__ if (run.bouncemail) send_bouncemail(ctl, msg, XMIT_ACCEPT, "Invalid address in MAIL FROM (SMTP error 553).\r\n", 1, responses); #endif /* __DONT_FEED_THE_SPAMMERS__ */ free(responses[0]); return(PS_REFUSED); case 530: /* must issue STARTTLS error */ /* * Some SMTP servers insist on encrypted communication * Let's set PS_TRANSIENT, otherwise all messages to be sent * over such server would be blackholed - see RFC 3207. */ if (outlevel > O_SILENT) report_complete(stdout, GT_("SMTP server requires STARTTLS, keeping message.\n")); free(responses[0]); return(PS_TRANSIENT); default: /* bounce non-transient errors back to the sender */ if (smtperr >= 500 && smtperr <= 599) { if (run.bouncemail) send_bouncemail(ctl, msg, XMIT_ACCEPT, "General SMTP/ESMTP error.\r\n", 1, responses); free(responses[0]); return(PS_REFUSED); } /* * We're going to end up here on 4xx errors, like: * * 451: temporarily unable to identify sender (exim) * 452: temporary out-of-queue-space condition on the ESMTP server. * * These are temporary errors. Don't try to ship the message, * and suppress deletion so it can be retried on a future * retrieval cycle. * * Bouncemail *might* be appropriate here as a delay * notification (note; if we ever add this, we must make * sure the RFC1894 Action field is "delayed" rather than * "failed"). But it's not really necessary because * these are not actual failures, we're very likely to be * able to recover on the next cycle. */ free(responses[0]); return(PS_TRANSIENT); } } static int handle_smtp_report_without_bounce(struct query *ctl, struct msgblk *msg) /* handle SMTP errors based on the content of SMTP_response */ /* atleast one PS_TRANSIENT: do not send the bounce mail, keep the mail; * no PS_TRANSIENT, atleast one PS_SUCCESS: send the bounce mail, delete the mail; * no PS_TRANSIENT, no PS_SUCCESS: do not send the bounce mail, delete the mail */ { int smtperr = atoi(smtp_response); (void)msg; if (str_find(&ctl->antispam, smtperr)) { if (run.spambounce) return(PS_SUCCESS); return(PS_REFUSED); } if (smtperr >= 400) report(stderr, GT_("%cMTP error: %s\n"), ctl->smtphostmode, smtp_response); switch (smtperr) { case 552: /* message exceeds fixed maximum message size */ if (run.bouncemail) return(PS_SUCCESS); return(PS_REFUSED); case 553: /* invalid sending domain */ #ifdef __DONT_FEED_THE_SPAMMERS__ if (run.bouncemail) return(PS_SUCCESS); #endif /* __DONT_FEED_THE_SPAMMERS__ */ return(PS_REFUSED); default: /* bounce non-transient errors back to the sender */ if (smtperr >= 500 && smtperr <= 599) return(PS_SUCCESS); return(PS_TRANSIENT); } } /* these are shared by open_sink and stuffline */ static FILE *sinkfp; 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 + 1; /* last[-1] must be valid! */ 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 .<CR><LF> as EOM. If it does, the server will already have * decorated any . lines it sends back up. */ if (*buf == '.') { if (ctl->server.base_protocol->delimited) /* server has already byte-stuffed */ { if (ctl->mda) { /* writing to MDA, undo byte-stuffing */ ++buf; } else { /* writing to SMTP, leave the byte-stuffing in place */; } } else /* if (!protocol->delimited) -- not byte-stuffed already */ { /* byte-stuff it */ if (!ctl->mda) { if (!ctl->bsmtp) { n = SockWrite(ctl->smtp_socket, buf, 1); } else { n = fwrite(buf, 1, 1, sinkfp); if (ferror(sinkfp)) n = -1; } if (n < 0) return n; } } } /* 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 || ctl->bsmtp) { n = fwrite(buf, 1, last - buf, sinkfp); if (ferror(sinkfp)) n = -1; } else if (ctl->smtp_socket != -1) n = SockWrite(ctl->smtp_socket, buf, last - buf); phase = oldphase; return(n); } static int open_bsmtp_sink(struct query *ctl, struct msgblk *msg, int *good_addresses, int *bad_addresses) /* open a BSMTP stream */ { struct idlist *idp; int need_anglebrs; if (strcmp(ctl->bsmtp, "-") == 0) sinkfp = stdout; else sinkfp = fopen(ctl->bsmtp, "a"); if (!sinkfp || ferror(sinkfp)) { report(stderr, GT_("BSMTP file open failed: %s\n"), strerror(errno)); return(PS_BSMTP); } /* see the ap computation under the SMTP branch */ need_anglebrs = (msg->return_path[0] != '<'); fprintf(sinkfp, "MAIL FROM:%s%s%s", need_anglebrs ? "<" : "", (msg->return_path[0]) ? msg->return_path : user, need_anglebrs ? ">" : ""); if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT)) fputs(" BODY=8BITMIME", sinkfp); else if (ctl->mimemsg & MSG_IS_7BIT) fputs(" BODY=7BIT", sinkfp); /* exim's BSMTP processor does not handle SIZE */ /* fprintf(sinkfp, " SIZE=%d", msg->reallen); */ fprintf(sinkfp, "\r\n"); /* * 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. Now that we have the actual hostname, * compute what we should canonicalize with. */ xfree(ctl->destaddr); ctl->destaddr = xstrdup(ctl->smtpaddress ? ctl->smtpaddress : "localhost"); *bad_addresses = 0; for (idp = msg->recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_ACCEPT) { fprintf(sinkfp, "RCPT TO:<%s>\r\n", rcpt_address (ctl, idp->id, 1)); (*good_addresses)++; } fputs("DATA\r\n", sinkfp); if (fflush(sinkfp) || ferror(sinkfp)) { report(stderr, GT_("BSMTP preamble write failed.\n")); return(PS_BSMTP); } return(PS_SUCCESS); } /* this is experimental and will be removed if double bounces are reported */ #define EXPLICIT_BOUNCE_ON_BAD_ADDRESS static const char *is_quad(const char *q) /* Check if the string passed in points to what could be one quad of a * dotted-quad IP address. Requirements are that the string is not a * NULL pointer, begins with a period (which is skipped) or a digit * and ends with a period or a NULL. If these requirements are met, a * pointer to the last character (the period or the NULL character) is * returned; otherwise NULL. */ { const char *r; if (!q || !*q) return NULL; if (*q == '.') q++; for(r=q;isdigit((unsigned char)*r);r++) ; if ( ((*r) && (*r != '.')) || ((r-q) < 1) || ((r-q)>3) ) return NULL; /* Make sure quad is < 255 */ if ( (r-q) == 3) { if (*q > '2') return NULL; else if (*q == '2') { if (*(q+1) > '5') return NULL; else if (*(q+1) == '5') { if (*(q+2) > '5') return NULL; } } } return r; } static int is_dottedquad(const char *hostname) /* Returns a true value if the passed in string looks like an IP * address in dotted-quad form, and a false value otherwise. */ { return ((hostname=is_quad(is_quad(is_quad(is_quad(hostname))))) != NULL) && (*hostname == '\0'); } static int open_smtp_sink(struct query *ctl, struct msgblk *msg, int *good_addresses, int *bad_addresses /* this must be signed, to prevent endless loop in from_addresses */) /* open an SMTP stream */ { const char *ap; struct idlist *idp; char options[MSGBUFSIZE]; char addr[HOSTLEN+USERNAMELEN+1]; #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS char **from_responses; #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */ int total_addresses; int force_transient_error = 0; int smtp_err; /* * Compute ESMTP options. */ options[0] = '\0'; if (ctl->server.esmtp_options & ESMTP_8BITMIME) { if (ctl->pass8bits || (ctl->mimemsg & MSG_IS_8BIT)) strcpy(options, " BODY=8BITMIME"); else if (ctl->mimemsg & MSG_IS_7BIT) strcpy(options, " BODY=7BIT"); } if ((ctl->server.esmtp_options & ESMTP_SIZE) && msg->reallen > 0) sprintf(options + strlen(options), " SIZE=%d", msg->reallen); /* * Try to get the SMTP listener to take the Return-Path * address as MAIL FROM. If it won't, fall back on the * remotename and mailserver host. This won't affect replies, * which use the header From address anyway; the MAIL FROM * address is a place for the SMTP listener to send * bouncemail. The point is to guarantee a FQDN in the MAIL * FROM line -- some SMTP listeners, like smail, become * unhappy otherwise. * * 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 Return-Path * 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. * * Handle the case where an upstream MTA is setting a return * path equal to "@". Ghod knows why anyone does this, but * it's been reported to happen in mail from Amazon.com and * Motorola. * * Also, if the hostname is a dotted quad, wrap it in square brackets. * Apparently this is required by RFC2821, section 4.1.3. */ if (!msg->return_path[0] || (msg->return_path[0] == '@')) { if (strchr(ctl->remotename,'@') || strchr(ctl->remotename,'!')) { snprintf(addr, sizeof(addr), "%s", ctl->remotename); } else if (is_dottedquad(ctl->server.truename)) { snprintf(addr, sizeof(addr), "%s@[%s]", ctl->remotename, ctl->server.truename); } else { snprintf(addr, sizeof(addr), "%s@%s", ctl->remotename, ctl->server.truename); } ap = addr; } else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!')) ap = msg->return_path; /* in case Return-Path was "<>" we want to preserve that */ else if (strcmp(msg->return_path,"<>") == 0) ap = msg->return_path; else /* in case Return-Path existed but was local */ { if (is_dottedquad(ctl->server.truename)) { snprintf(addr, sizeof(addr), "%s@[%s]", msg->return_path, ctl->server.truename); } else { snprintf(addr, sizeof(addr), "%s@%s", msg->return_path, ctl->server.truename); } ap = addr; } if ((smtp_err = SMTP_from(ctl->smtp_socket, ctl->smtphostmode, ap, options)) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); return(PS_TRANSIENT); } if (smtp_err != SM_OK) { int err = handle_smtp_report(ctl, msg); /* map to PS_TRANSIENT or PS_REFUSED */ smtp_rset(ctl); /* stay on the safe side */ return(err); } /* * Now list the recipient addressees */ total_addresses = 0; for (idp = msg->recipients; idp; idp = idp->next) total_addresses++; #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS from_responses = (char **)xmalloc(sizeof(char *) * total_addresses); #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */ for (idp = msg->recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_ACCEPT) { const char *address; address = rcpt_address (ctl, idp->id, 1); if ((smtp_err = SMTP_rcpt(ctl->smtp_socket, ctl->smtphostmode, address)) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); transient: #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS while (*bad_addresses) free(from_responses[--*bad_addresses]); free(from_responses); #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */ return(PS_TRANSIENT); } if (smtp_err == SM_OK) (*good_addresses)++; else { switch (handle_smtp_report_without_bounce(ctl, msg)) { case PS_TRANSIENT: force_transient_error = 1; break; case PS_SUCCESS: #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS from_responses[*bad_addresses] = xstrdup(smtp_response); #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */ (*bad_addresses)++; idp->val.status.mark = XMIT_RCPTBAD; if (outlevel >= O_VERBOSE) report(stderr, GT_("%cMTP listener doesn't like recipient address `%s'\n"), ctl->smtphostmode, address); break; case PS_REFUSED: if (outlevel >= O_VERBOSE) report(stderr, GT_("%cMTP listener doesn't really like recipient address `%s'\n"), ctl->smtphostmode, address); break; } } } if (force_transient_error) { /* do not risk dataloss due to overengineered multidrop * crap. If one of the recipients returned PS_TRANSIENT, * we return exactly that. */ smtp_rset(ctl); /* required by RFC1870 */ goto transient; } #ifdef EXPLICIT_BOUNCE_ON_BAD_ADDRESS /* * This should not be necessary, because the SMTP listener itself * should generate a bounce for the bad address. * * XXX FIXME 2006-01-19: is this comment true? I don't think * it is, because the SMTP listener isn't required to accept bogus * messages. There appears to be general SMTP<->MDA and * responsibility confusion. */ if (*bad_addresses) send_bouncemail(ctl, msg, XMIT_RCPTBAD, "Some addresses were rejected by the MDA fetchmail forwards to.\r\n", *bad_addresses, from_responses); while (*bad_addresses) free(from_responses[--*bad_addresses]); free(from_responses); #endif /* EXPLICIT_BOUNCE_ON_BAD_ADDRESS */ /* * It's tempting to do local notification only if bouncemail was * insufficient -- that is, to add && total_addresses > *bad_addresses * to the test here. The problem with this theory is that it would * make initial diagnosis of a broken multidrop configuration very * hard -- most single-recipient messages would just invisibly bounce. */ if (!(*good_addresses)) { if (!run.postmaster[0]) { if (outlevel >= O_VERBOSE) report(stderr, GT_("no address matches; no postmaster set.\n")); smtp_rset(ctl); /* required by RFC1870 */ return(PS_REFUSED); } if ((smtp_err = SMTP_rcpt(ctl->smtp_socket, ctl->smtphostmode, rcpt_address (ctl, run.postmaster, 0))) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); return(PS_TRANSIENT); } if (smtp_err != SM_OK) { report(stderr, GT_("can't even send to %s!\n"), run.postmaster); smtp_rset(ctl); /* required by RFC1870 */ return(PS_REFUSED); } if (outlevel >= O_VERBOSE) report(stderr, GT_("no address matches; forwarding to %s.\n"), run.postmaster); } /* * Tell the listener we're ready to send data. * Some listeners (like zmailer) may return antispam errors here. */ if ((smtp_err = SMTP_data(ctl->smtp_socket, ctl->smtphostmode)) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); return(PS_TRANSIENT); } if (smtp_err != SM_OK) { int err = handle_smtp_report(ctl, msg); smtp_rset(ctl); /* stay on the safe side */ return(err); } /* * We need to stash this away in order to know how many * response lines to expect after the LMTP end-of-message. */ lmtp_responses = *good_addresses; return(PS_SUCCESS); } static int open_mda_sink(struct query *ctl, struct msgblk *msg, int *good_addresses, int *bad_addresses) /* open a stream to a local MDA */ { #ifdef HAVE_SETEUID uid_t orig_uid; #endif /* HAVE_SETEUID */ struct idlist *idp; int length = 0, fromlen = 0, nameslen = 0; char *names = NULL, *before, *after, *from = NULL; (void)bad_addresses; xfree(ctl->destaddr); ctl->destaddr = xstrdup("localhost"); for (idp = msg->recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_ACCEPT) (*good_addresses)++; length = strlen(ctl->mda); before = xstrdup(ctl->mda); /* get user addresses for %T (or %s for backward compatibility) */ if (strstr(before, "%s") || strstr(before, "%T")) { /* * We go through this in order to be able to handle very * long lists of users and (re)implement %s. */ nameslen = 0; for (idp = msg->recipients; idp; idp = idp->next) if ((idp->val.status.mark == XMIT_ACCEPT)) nameslen += (strlen(idp->id) + 1); /* string + ' ' */ if ((*good_addresses == 0)) nameslen = strlen(run.postmaster); names = (char *)xmalloc(nameslen + 1); /* account for '\0' */ if (*good_addresses == 0) strcpy(names, run.postmaster); else { names[0] = '\0'; for (idp = msg->recipients; idp; idp = idp->next) if (idp->val.status.mark == XMIT_ACCEPT) { strcat(names, idp->id); strcat(names, " "); } names[--nameslen] = '\0'; /* chop trailing space */ } sanitize(names); } /* get From address for %F */ if (strstr(before, "%F")) { from = xstrdup(msg->return_path); sanitize(from); fromlen = strlen(from); } /* do we have to build an mda string? */ if (names || from) { char *sp, *dp; /* find length of resulting mda string */ sp = before; while ((sp = strstr(sp, "%s"))) { length += nameslen; /* subtract %s and add '' */ sp += 2; } sp = before; while ((sp = strstr(sp, "%T"))) { length += nameslen; /* subtract %T and add '' */ sp += 2; } sp = before; while ((sp = strstr(sp, "%F"))) { length += fromlen; /* subtract %F and add '' */ sp += 2; } after = (char *)xmalloc(length + 1); /* copy mda source string to after, while expanding %[sTF] */ for (dp = after, sp = before; (*dp = *sp); dp++, sp++) { if (sp[0] != '%') continue; /* need to expand? BTW, no here overflow, because in ** the worst case (end of string) sp[1] == '\0' */ if (sp[1] == 's' || sp[1] == 'T') { *dp++ = '\''; strcpy(dp, names); dp += nameslen; *dp++ = '\''; sp++; /* position sp over [sT] */ dp--; /* adjust dp */ } else if (sp[1] == 'F') { *dp++ = '\''; strcpy(dp, from); dp += fromlen; *dp++ = '\''; sp++; /* position sp over F */ dp--; /* adjust dp */ } } if (names) { free(names); names = NULL; } if (from) { free(from); from = NULL; } free(before); before = after; } if (outlevel >= O_DEBUG) report(stdout, GT_("about to deliver with: %s\n"), 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) */ orig_uid = getuid(); seteuid(ctl->uid); #endif /* HAVE_SETEUID */ sinkfp = popen(before, "w"); free(before); before = NULL; #ifdef HAVE_SETEUID /* this will fail quietly if we didn't start as root */ seteuid(orig_uid); #endif /* HAVE_SETEUID */ if (!sinkfp) { report(stderr, GT_("MDA open failed\n")); return(PS_IOERR); } /* * We need to disable the normal SIGCHLD handling here because * sigchld_handler() would reap away the error status, returning * error status instead of 0 for successful completion. */ set_signal_handler(SIGCHLD, SIG_DFL); return(PS_SUCCESS); } int open_sink(struct query *ctl, struct msgblk *msg, int *good_addresses, int *bad_addresses) /* set up sinkfp to be an input sink we can ship a message to */ { *bad_addresses = *good_addresses = 0; if (ctl->bsmtp) /* dump to a BSMTP batch file */ return(open_bsmtp_sink(ctl, msg, good_addresses, bad_addresses)); /* * Try to forward to an SMTP or LMTP listener. If the attempt to * open a socket fails, fall through to attempt delivery via * local MDA. */ else if (!ctl->mda && smtp_open(ctl) != -1) return(open_smtp_sink(ctl, msg, good_addresses, bad_addresses)); /* * Awkward case. User didn't specify an MDA. Our attempt to get a * listener socket failed. Try to cope anyway -- initial configuration * may have found procmail. */ else if (!ctl->mda) { report(stderr, GT_("%cMTP connect to %s failed\n"), ctl->smtphostmode, ctl->smtphost ? ctl->smtphost : "localhost"); #ifndef FALLBACK_MDA /* No fallback MDA declared. Bail out. */ return(PS_SMTP); #else /* * If user had things set up to forward offsite, no way * we want to deliver locally! */ if (ctl->smtphost && strcmp(ctl->smtphost, "localhost")) return(PS_SMTP); /* * User was delivering locally. We have a fallback MDA. * Latch it in place, logging the error, and fall through. * Set stripcr as we would if MDA had been the initial transport */ ctl->mda = FALLBACK_MDA; if (!ctl->forcecr) ctl->stripcr = TRUE; report(stderr, GT_("can't raise the listener; falling back to %s"), FALLBACK_MDA); #endif } if (ctl->mda) /* must deliver through an MDA */ return(open_mda_sink(ctl, msg, good_addresses, bad_addresses)); return(PS_SUCCESS); } void release_sink(struct query *ctl) /* release the per-message output sink, whether it's a pipe or SMTP socket */ { if (ctl->bsmtp && sinkfp) { if (strcmp(ctl->bsmtp, "-")) { fclose(sinkfp); sinkfp = (FILE *)NULL; } } else if (ctl->mda) { if (sinkfp) { pclose(sinkfp); sinkfp = (FILE *)NULL; } deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */ } } int close_sink(struct query *ctl, struct msgblk *msg, flag forward) /* perform end-of-message actions on the current output sink */ { int smtp_err; if (ctl->mda) { int rc = 0, e = 0, e2 = 0, err = 0; /* close the delivery pipe, we'll reopen before next message */ if (sinkfp) { if (ferror(sinkfp)) err = 1, e2 = errno; if ((fflush(sinkfp))) err = 1, e2 = errno; errno = 0; rc = pclose(sinkfp); e = errno; sinkfp = (FILE *)NULL; } else rc = e = 0; deal_with_sigchld(); /* Restore SIGCHLD handling to reap zombies */ if (rc || err) { if (err) { report(stderr, GT_("Error writing to MDA: %s\n"), strerror(e2)); } else if (WIFSIGNALED(rc)) { report(stderr, GT_("MDA died of signal %d\n"), WTERMSIG(rc)); } else if (WIFEXITED(rc)) { report(stderr, GT_("MDA returned nonzero status %d\n"), WEXITSTATUS(rc)); } else { report(stderr, GT_("Strange: MDA pclose returned %d and errno %d/%s, cannot handle at %s:%d\n"), rc, e, strerror(e), __FILE__, __LINE__); } return(FALSE); } } else if (ctl->bsmtp && sinkfp) { int error; /* implicit disk-full check here... */ fputs(".\r\n", sinkfp); error = ferror(sinkfp); if (strcmp(ctl->bsmtp, "-")) { if (fclose(sinkfp) == EOF) error = 1; sinkfp = (FILE *)NULL; } if (error) { report(stderr, GT_("Message termination or close of BSMTP file failed\n")); return(FALSE); } } else if (forward) { /* write message terminator */ if ((smtp_err = SMTP_eom(ctl->smtp_socket, ctl->smtphostmode)) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); return(FALSE); } if (smtp_err != SM_OK) { if (handle_smtp_report(ctl, msg) != PS_REFUSED) { smtp_rset(ctl); /* stay on the safe side */ return(FALSE); } else { report(stderr, GT_("SMTP listener refused delivery\n")); smtp_rset(ctl); /* stay on the safe side */ return(TRUE); } } /* * If this is an SMTP connection, SMTP_eom() ate the response. * But could be this is an LMTP connection, in which case we have to * interpret either (a) a single 503 response meaning there * were no successful RCPT TOs, or (b) a variable number of * responses, one for each successful RCPT TO. We need to send * bouncemail on each failed response and then return TRUE anyway, * otherwise the message will get left in the queue and resent * to people who got it the first time. */ if (ctl->smtphostmode == LMTP_MODE) { if (lmtp_responses == 0) { SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_EOM); /* * According to RFC2033, 503 is the only legal response * if no RCPT TO commands succeeded. No error recovery * is really possible here, as we have no idea what * insane thing the listener might be doing if it doesn't * comply. */ if (atoi(smtp_response) == 503) report(stderr, GT_("LMTP delivery error on EOM\n")); else report(stderr, GT_("Unexpected non-503 response to LMTP EOM: %s\n"), smtp_response); /* * It's not completely clear what to do here. We choose to * interpret delivery failure here as a transient error, * the same way SMTP delivery failure is handled. If we're * wrong, an undead message will get stuck in the queue. */ return(FALSE); } else { int i, errors, rc = FALSE; char **responses; /* eat the RFC2033-required responses, saving errors */ responses = (char **)xmalloc(sizeof(char *) * lmtp_responses); for (errors = i = 0; i < lmtp_responses; i++) { if ((smtp_err = SMTP_ok(ctl->smtp_socket, ctl->smtphostmode, TIMEOUT_EOM)) == SM_UNRECOVERABLE) { smtp_close(ctl, 0); goto unrecov; } if (smtp_err != SM_OK) { responses[errors] = xstrdup(smtp_response); errors++; } } if (errors == 0) rc = TRUE; /* all deliveries succeeded */ else /* * One or more deliveries failed. * If we can bounce a failures list back to the * sender, and the postmaster does not want to * deal with the bounces return TRUE, deleting the * message from the server so it won't be * re-forwarded on subsequent poll cycles. */ rc = send_bouncemail(ctl, msg, XMIT_ACCEPT, "LMTP partial delivery failure.\r\n", errors, responses); unrecov: for (i = 0; i < errors; i++) free(responses[i]); free(responses); return rc; } } } return(TRUE); } int open_warning_by_mail(struct query *ctl) /* set up output sink for a mailed warning to calling user */ { int good, bad; /* * Dispatching warning email is a little complicated. The problem is * that we have to deal with three distinct cases: * * 1. Single-drop running from user account. Warning mail should * go to the local name for which we're collecting (coincides * with calling user). * * 2. Single-drop running from root or other privileged ID, with rc * file generated on the fly (Ken Estes's weird setup...) Mail * should go to the local name for which we're collecting (does not * coincide with calling user). * * 3. Multidrop. Mail must go to postmaster. We leave the recipients * member null so this message will fall through to run.postmaster. * * The zero in the reallen element means we won't pass a SIZE * option to ESMTP; the message length would be more trouble than * it's worth to compute. */ struct msgblk reply = {NULL, NULL, "FETCHMAIL-DAEMON@", 0, 0}; int status; strlcat(reply.return_path, ctl->smtpaddress ? ctl->smtpaddress : fetchmailhost, sizeof(reply.return_path)); if (!MULTIDROP(ctl)) /* send to calling user */ { save_str(&reply.recipients, ctl->localnames->id, XMIT_ACCEPT); status = open_sink(ctl, &reply, &good, &bad); free_str_list(&reply.recipients); } else /* send to postmaster */ status = open_sink(ctl, &reply, &good, &bad); if (status == 0) { stuff_warning(NULL, ctl, "From: FETCHMAIL-DAEMON@%s", ctl->smtpaddress ? ctl->smtpaddress : fetchmailhost); stuff_warning(NULL, ctl, "Date: %s", rfc822timestamp()); stuff_warning(NULL, ctl, "MIME-Version: 1.0"); stuff_warning(NULL, ctl, "Content-Transfer-Encoding: 8bit"); stuff_warning(NULL, ctl, "Content-Type: text/plain; charset=\"%s\"", iana_charset); } return(status); } /* format and ship a warning message line by mail */ /* if rfc2047charset is non-NULL, encode the line (that is assumed to be * a header line) as per RFC-2047 using rfc2047charset as the character * set field */ #if defined(HAVE_STDARG_H) void stuff_warning(const char *rfc2047charset, struct query *ctl, const char *fmt, ... ) #else void stuff_warning(rfc2047charset, ctl, fmt, va_alist) const char *charset; struct query *ctl; const char *fmt; /* printf-style format */ va_dcl #endif { /* make huge -- i18n can bulk up error messages a lot */ char buf[2*MSGBUFSIZE+4]; va_list ap; /* * stuffline() requires its input to be writeable (for CR stripping), * so we needed to copy the message to a writeable buffer anyway in * case it was a string constant. We make a virtue of that necessity * here by supporting stdargs/varargs. */ #if defined(HAVE_STDARG_H) va_start(ap, fmt) ; #else va_start(ap); #endif vsnprintf(buf, sizeof(buf) - 2, fmt, ap); va_end(ap); snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "\r\n"); /* guard against very long lines */ buf[MSGBUFSIZE+1] = '\r'; buf[MSGBUFSIZE+2] = '\n'; buf[MSGBUFSIZE+3] = '\0'; stuffline(ctl, rfc2047charset != NULL ? rfc2047e(buf, rfc2047charset) : buf); } void close_warning_by_mail(struct query *ctl, struct msgblk *msg) /* sign and send mailed warnings */ { stuff_warning(NULL, ctl, GT_("-- \nThe Fetchmail Daemon")); close_sink(ctl, msg, TRUE); } /* sink.c ends here */


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