From a5bd321b2f16ff323e3e268d59606e89b747a901 Mon Sep 17 00:00:00 2001 From: Philip Hazel Date: Thu, 13 Jul 2006 13:53:32 +0000 Subject: Add recognition of SMTP error codes in bespoke messages. --- src/README.UPDATING | 18 ++++++++- src/src/exim.c | 9 ++++- src/src/functions.h | 4 +- src/src/globals.c | 35 +++++++++--------- src/src/globals.h | 5 ++- src/src/receive.c | 22 +++++------ src/src/routers/redirect.c | 32 ++++++++++++---- src/src/routers/redirect.h | 3 +- src/src/smtp_in.c | 92 ++++++++++++++++++++++++++++++++++++---------- 9 files changed, 158 insertions(+), 62 deletions(-) (limited to 'src') diff --git a/src/README.UPDATING b/src/README.UPDATING index 05f89f40e..e4975ba6a 100644 --- a/src/README.UPDATING +++ b/src/README.UPDATING @@ -1,4 +1,4 @@ -$Cambridge: exim/src/README.UPDATING,v 1.11 2006/02/20 16:31:49 ph10 Exp $ +$Cambridge: exim/src/README.UPDATING,v 1.12 2006/07/13 13:53:33 ph10 Exp $ This document contains detailed information about incompatibilities that might be encountered when upgrading from one release of Exim to another. The @@ -28,6 +28,22 @@ The rest of this document contains information about changes in 4.xx releases that might affect a running system. +Exim version 4.63 +----------------- + +When an SMTP error message is specified in a "message" modifier in an ACL, or +in a :fail: or :defer: message in a redirect router, Exim now checks the start +of the message for an SMTP error code. This consists of three digits followed +by a space, optionally followed by an extended code of the form n.n.n, also +followed by a space. If this is the case and the very first digit is the same +as the default error code, the code from the message is used instead. If the +very first digit is incorrect, a panic error is logged, and the default code is +used. This is an incompatible change, but it is not expected to affect many (if +any) configurations. It is possible to suppress the use of the supplied code in +a redirect router by setting the smtp_error_code option false. In this case, +any SMTP code is quietly ignored. + + Exim version 4.61 ----------------- diff --git a/src/src/exim.c b/src/src/exim.c index a40ded77e..3ac7d8313 100644 --- a/src/src/exim.c +++ b/src/src/exim.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/exim.c,v 1.40 2006/06/28 16:00:24 ph10 Exp $ */ +/* $Cambridge: exim/src/src/exim.c,v 1.41 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -1492,6 +1492,13 @@ using mac_ismsgid, which uses this. */ regex_ismsgid = regex_must_compile(US"^(?:[^\\W_]{6}-){2}[^\\W_]{2}$", FALSE, TRUE); +/* Precompile the regular expression that is used for matching an SMTP error +code, possibly extended, at the start of an error message. */ + +regex_smtp_code = + regex_must_compile(US"^\\d\\d\\d\\s(?:\\d\\.\\d\\d?\\d?\\.\\d\\d?\\d?\\s)?", + FALSE, TRUE); + /* If the program is called as "mailq" treat it as equivalent to "exim -bp"; this seems to be a generally accepted convention, since one finds symbolic links called "mailq" in standard OS configurations. */ diff --git a/src/src/functions.h b/src/src/functions.h index 2728d79f1..32b3d2d24 100644 --- a/src/src/functions.h +++ b/src/src/functions.h @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/functions.h,v 1.24 2006/03/08 11:13:07 ph10 Exp $ */ +/* $Cambridge: exim/src/src/functions.h,v 1.25 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -266,7 +266,7 @@ extern BOOL smtp_get_port(uschar *, address_item *, int *, uschar *); extern int smtp_getc(void); extern int smtp_handle_acl_fail(int, int, uschar *, uschar *); extern BOOL smtp_read_response(smtp_inblock *, uschar *, int, int, int); -extern void smtp_respond(int, BOOL, uschar *); +extern void smtp_respond(uschar *, int, BOOL, uschar *); extern void smtp_send_prohibition_message(int, uschar *); extern int smtp_setup_msg(void); extern BOOL smtp_start_session(void); diff --git a/src/src/globals.c b/src/src/globals.c index 4455f384e..2a6aba592 100644 --- a/src/src/globals.c +++ b/src/src/globals.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/globals.c,v 1.54 2006/06/28 16:00:24 ph10 Exp $ */ +/* $Cambridge: exim/src/src/globals.c,v 1.55 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -211,22 +211,22 @@ uschar *acl_wherenames[] = { US"RCPT", US"VRFY" }; -int acl_wherecodes[] = { 550, /* RCPT */ - 550, /* MAIL */ - 550, /* PREDATA */ - 550, /* MIME */ - 550, /* DATA */ - 0, /* not SMTP; not relevant */ - 503, /* AUTH */ - 550, /* connect */ - 458, /* ETRN */ - 550, /* EXPN */ - 550, /* HELO/EHLO */ - 0, /* MAILAUTH; not relevant */ - 0, /* not SMTP; not relevant */ - 0, /* QUIT; not relevant */ - 550, /* STARTTLS */ - 252 /* VRFY */ +uschar *acl_wherecodes[] = { US"550", /* RCPT */ + US"550", /* MAIL */ + US"550", /* PREDATA */ + US"550", /* MIME */ + US"550", /* DATA */ + US"0", /* not SMTP; not relevant */ + US"503", /* AUTH */ + US"550", /* connect */ + US"458", /* ETRN */ + US"550", /* EXPN */ + US"550", /* HELO/EHLO */ + US"0", /* MAILAUTH; not relevant */ + US"0", /* not SMTP; not relevant */ + US"0", /* QUIT; not relevant */ + US"550", /* STARTTLS */ + US"252" /* VRFY */ }; BOOL active_local_from_check = FALSE; @@ -866,6 +866,7 @@ const pcre *regex_From = NULL; const pcre *regex_IGNOREQUOTA = NULL; const pcre *regex_PIPELINING = NULL; const pcre *regex_SIZE = NULL; +const pcre *regex_smtp_code = NULL; const pcre *regex_ismsgid = NULL; #ifdef WITH_CONTENT_SCAN uschar *regex_match_string = NULL; diff --git a/src/src/globals.h b/src/src/globals.h index 53272ceef..a235869c1 100644 --- a/src/src/globals.h +++ b/src/src/globals.h @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/globals.h,v 1.38 2006/06/28 16:00:24 ph10 Exp $ */ +/* $Cambridge: exim/src/src/globals.h,v 1.39 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -131,7 +131,7 @@ extern BOOL acl_temp_details; /* TRUE to give details for 4xx error */ extern uschar *acl_var[ACL_CVARS+ACL_MVARS]; /* User ACL variables */ extern uschar *acl_verify_message; /* User message for verify failure */ extern string_item *acl_warn_logged; /* Logged lines */ -extern int acl_wherecodes[]; /* Response codes for ACL fails */ +extern uschar *acl_wherecodes[]; /* Response codes for ACL fails */ extern uschar *acl_wherenames[]; /* Names for messages */ extern BOOL active_local_from_check;/* For adding Sender: (switchable) */ extern BOOL active_local_sender_retain; /* For keeping Sender: (switchable) */ @@ -556,6 +556,7 @@ extern const pcre *regex_From; /* For recognizing "From_" lines */ extern const pcre *regex_IGNOREQUOTA; /* For recognizing IGNOREQUOTA (LMTP) */ extern const pcre *regex_PIPELINING; /* For recognizing PIPELINING */ extern const pcre *regex_SIZE; /* For recognizing SIZE settings */ +extern const pcre *regex_smtp_code; /* For recognizing SMTP codes */ extern const pcre *regex_ismsgid; /* Compiled r.e. for message it */ #ifdef WITH_CONTENT_SCAN extern uschar *regex_match_string; /* regex that matched a line (regex ACL condition) */ diff --git a/src/src/receive.c b/src/src/receive.c index f711e9ca8..3f430f1aa 100644 --- a/src/src/receive.c +++ b/src/src/receive.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/receive.c,v 1.27 2006/03/06 16:05:12 ph10 Exp $ */ +/* $Cambridge: exim/src/src/receive.c,v 1.28 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -1067,7 +1067,7 @@ if (mbox_file == NULL) { "acl_smtp_mime: error while creating mbox spool file, message temporarily rejected."); Uunlink(spool_name); unspool_mbox(); - smtp_respond(451, TRUE, US"temporary local problem"); + smtp_respond(US"451", 3, TRUE, US"temporary local problem"); message_id[0] = 0; /* Indicate no message accepted */ *smtp_reply_ptr = US""; /* Indicate reply already sent */ return FALSE; /* Indicate skip to end of receive function */ @@ -3110,9 +3110,9 @@ else { uschar *istemp = US""; uschar *s = NULL; + uschar *smtp_code; int size = 0; int sptr = 0; - int code; errmsg = local_scan_data; @@ -3129,7 +3129,7 @@ else /* Fall through */ case LOCAL_SCAN_REJECT: - code = 550; + smtp_code = US"550"; if (errmsg == NULL) errmsg = US"Administrative prohibition"; break; @@ -3139,7 +3139,7 @@ else case LOCAL_SCAN_TEMPREJECT: TEMPREJECT: - code = 451; + smtp_code = US"451"; if (errmsg == NULL) errmsg = US"Temporary local problem"; istemp = US"temporarily "; break; @@ -3157,14 +3157,14 @@ else { if (!smtp_batched_input) { - smtp_respond(code, TRUE, errmsg); + smtp_respond(smtp_code, 3, TRUE, errmsg); message_id[0] = 0; /* Indicate no message accepted */ smtp_reply = US""; /* Indicate reply already sent */ goto TIDYUP; /* Skip to end of function */ } else { - moan_smtp_batch(NULL, "%d %s", code, errmsg); + moan_smtp_batch(NULL, "%s %s", smtp_code, errmsg); /* Does not return */ } } @@ -3483,8 +3483,8 @@ if (smtp_input) if (smtp_reply == NULL) { if (fake_response != OK) - smtp_respond(fake_response == DEFER ? 450 : 550, - TRUE, fake_response_text); + smtp_respond((fake_response == DEFER)? US"450" : US"550", 3, TRUE, + fake_response_text); else smtp_printf("250 OK id=%s\r\n", message_id); if (host_checking) @@ -3494,8 +3494,8 @@ if (smtp_input) else if (smtp_reply[0] != 0) { if (fake_response != OK && (smtp_reply[0] == '2')) - smtp_respond(fake_response == DEFER ? 450 : 550, - TRUE, fake_response_text); + smtp_respond((fake_response == DEFER)? US"450" : US"550", 3, TRUE, + fake_response_text); else smtp_printf("%.1024s\r\n", smtp_reply); } diff --git a/src/src/routers/redirect.c b/src/src/routers/redirect.c index d94240ebc..2a9d5e3b2 100644 --- a/src/src/routers/redirect.c +++ b/src/src/routers/redirect.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/routers/redirect.c,v 1.16 2006/06/27 14:34:26 ph10 Exp $ */ +/* $Cambridge: exim/src/src/routers/redirect.c,v 1.17 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -71,6 +71,8 @@ optionlist redirect_router_options[] = { (void *)offsetof(redirect_router_options_block, forbid_pipe) }, { "forbid_sieve_filter",opt_bit | (RDON_SIEVE_FILTER << 16), (void *)offsetof(redirect_router_options_block, bit_options) }, + { "forbid_smtp_code", opt_bool, + (void *)offsetof(redirect_router_options_block, forbid_smtp_code) }, { "hide_child_in_errmsg", opt_bool, (void *)offsetof(redirect_router_options_block, hide_child_in_errmsg) }, { "ignore_eacces", opt_bit | (RDON_EACCES << 16), @@ -169,6 +171,7 @@ redirect_router_options_block redirect_router_option_defaults = { FALSE, /* forbid_file */ FALSE, /* forbid_filter_reply */ FALSE, /* forbid_pipe */ + FALSE, /* forbid_smtp_code */ FALSE, /* hide_child_in_errmsg */ FALSE, /* one_time */ FALSE, /* qualify_preserve_domain */ @@ -711,26 +714,39 @@ switch (frc) break; /* FF_DEFER and FF_FAIL can arise only as a result of explicit commands - (:fail: in an alias file or "fail" in a filter). If a configured message was - supplied, allow it to be included in an SMTP response after verifying. */ + (:defer: or :fail: in an alias file or "fail" in a filter). If a configured + message was supplied, allow it to be included in an SMTP response after + verifying. Remove any SMTP code if it is not allowed. */ case FF_DEFER: - if (addr->message == NULL) addr->message = US"forced defer"; - else addr->user_message = addr->message; - return DEFER; + yield = DEFER; + goto SORT_MESSAGE; case FF_FAIL: if ((xrc = sort_errors_and_headers(rblock, addr, verify, &addr_prop)) != OK) return xrc; add_generated(rblock, addr_new, addr, generated, &addr_prop, &ugid, pw); + yield = FAIL; + + SORT_MESSAGE: if (addr->message == NULL) - addr->message = US"forced rejection"; + addr->message = (yield == FAIL)? US"forced rejection" : US"forced defer"; else { + int ovector[3]; + if (ob->forbid_smtp_code && + pcre_exec(regex_smtp_code, NULL, CS addr->message, + Ustrlen(addr->message), 0, PCRE_EOPT, + ovector, sizeof(ovector)/sizeof(int)) >= 0) + { + DEBUG(D_route) debug_printf("SMTP code at start of error message " + "is ignored because forbid_smtp_code is set\n"); + addr->message += ovector[1]; + } addr->user_message = addr->message; setflag(addr, af_pass_message); } - return FAIL; + return yield; /* As in the case of a system filter, a freeze does not happen after a manual thaw. In case deliveries were set up by the filter, we set the child count diff --git a/src/src/routers/redirect.h b/src/src/routers/redirect.h index 996f0b003..6825430fd 100644 --- a/src/src/routers/redirect.h +++ b/src/src/routers/redirect.h @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/routers/redirect.h,v 1.7 2006/02/07 11:19:02 ph10 Exp $ */ +/* $Cambridge: exim/src/src/routers/redirect.h,v 1.8 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -51,6 +51,7 @@ typedef struct { BOOL forbid_file; BOOL forbid_filter_reply; BOOL forbid_pipe; + BOOL forbid_smtp_code; BOOL hide_child_in_errmsg; BOOL one_time; BOOL qualify_preserve_domain; diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c index 99ac3fb1a..881bfff58 100644 --- a/src/src/smtp_in.c +++ b/src/src/smtp_in.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/smtp_in.c,v 1.38 2006/04/19 10:58:21 ph10 Exp $ */ +/* $Cambridge: exim/src/src/smtp_in.c,v 1.39 2006/07/13 13:53:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -1767,7 +1767,8 @@ responses. If no_multiline_responses is TRUE (it can be set from an ACL), we output nothing for non-final calls, and only the first line for anything else. Arguments: - code SMTP code + code SMTP code, may involve extended status codes + codelen length of smtp code; uf > 3 there's an ESC final FALSE if the last line isn't the final line msg message text, possibly containing newlines @@ -1775,26 +1776,36 @@ Returns: nothing */ void -smtp_respond(int code, BOOL final, uschar *msg) +smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg) { +int esclen = 0; +uschar *esc = US""; + if (!final && no_multiline_responses) return; +if (codelen > 3) + { + esc = code + 4; + esclen = codelen - 4; + } + for (;;) { uschar *nl = Ustrchr(msg, '\n'); if (nl == NULL) { - smtp_printf("%d%c%s\r\n", code, final? ' ':'-', msg); + smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg); return; } else if (nl[1] == 0 || no_multiline_responses) { - smtp_printf("%d%c%.*s\r\n", code, final? ' ':'-', (int)(nl - msg), msg); + smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc, + (int)(nl - msg), msg); return; } else { - smtp_printf("%d-%.*s\r\n", code, (int)(nl - msg), msg); + smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg); msg = nl + 1; while (isspace(*msg)) msg++; } @@ -1814,13 +1825,18 @@ logging the incident, and sets up the error response. A message containing newlines is turned into a multiline SMTP response, but for logging, only the first line is used. -There's a table of the response codes to use in globals.c, along with the table -of names. VFRY is special. Despite RFC1123 it defaults disabled in Exim. -However, discussion in connection with RFC 821bis (aka RFC 2821) has concluded -that the response should be 252 in the disabled state, because there are broken -clients that try VRFY before RCPT. A 5xx response should be given only when the -address is positively known to be undeliverable. Sigh. Also, for ETRN, 458 is -given on refusal, and for AUTH, 503. +There's a table of default permanent failure response codes to use in +globals.c, along with the table of names. VFRY is special. Despite RFC1123 it +defaults disabled in Exim. However, discussion in connection with RFC 821bis +(aka RFC 2821) has concluded that the response should be 252 in the disabled +state, because there are broken clients that try VRFY before RCPT. A 5xx +response should be given only when the address is positively known to be +undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH, +503. + +From Exim 4.63, it is possible to override the response code details by +providing a suitable response code string at the start of the message provided +in user_msg. The code's first digit is checked for validity. Arguments: where where the ACL was called from @@ -1837,8 +1853,10 @@ Returns: 0 in most cases int smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg) { -int code = acl_wherecodes[where]; BOOL drop = rc == FAIL_DROP; +int codelen = 3; +int ovector[3]; +uschar *smtp_code; uschar *lognl; uschar *sender_info = US""; uschar *what = @@ -1853,6 +1871,41 @@ uschar *what = if (drop) rc = FAIL; +/* Set the default SMTP code */ + +smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where]; + +/* Check a user message for starting with a response code and optionally an +extended status code. If found, check that the first digit is valid, and if so, +use it instead of the default code. */ + +if (user_msg != NULL) + { + int n = pcre_exec(regex_smtp_code, NULL, CS user_msg, Ustrlen(user_msg), 0, + PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int)); + if (n >= 0) + { + if (user_msg[0] != smtp_code[0]) + { + log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with " + "incorrect digit (expected %c) in \"%s\"", smtp_code[0], user_msg); + + /* If log_msg == user_msg (the default set in acl.c if no log message is + specified, we must adjust the log message to show the code that is + actually going to be used. */ + + if (log_msg == user_msg) + log_msg = string_sprintf("%s %s", smtp_code, log_msg + ovector[1]); + } + else + { + smtp_code = user_msg; + codelen = ovector[1]; /* Includes final space */ + } + user_msg += ovector[1]; /* Chop the code off the message */ + } + } + /* We used to have sender_address here; however, there was a bug that was not updating sender_address after a rewrite during a verify. When this bug was fixed, sender_address at this point became the rewritten address. I'm not sure @@ -1888,7 +1941,7 @@ if (sender_verified_failed != NULL && string_sprintf(": %s", sender_verified_failed->message)); if (rc == FAIL && sender_verified_failed->user_message != NULL) - smtp_respond(code, FALSE, string_sprintf( + smtp_respond(smtp_code, codelen, FALSE, string_sprintf( testflag(sender_verified_failed, af_verify_pmfail)? "Postmaster verification failed while checking <%s>\n%s\n" "Several RFCs state that you are required to have a postmaster\n" @@ -1918,7 +1971,7 @@ if (lognl != NULL) *lognl = 0; always a 5xx one - see comments at the start of this function. If the original rc was FAIL_DROP we drop the connection and yield 2. */ -if (rc == FAIL) smtp_respond(code, TRUE, (user_msg == NULL)? +if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)? US"Administrative prohibition" : user_msg); /* Send temporary failure response to the command. Don't give any details, @@ -1937,12 +1990,13 @@ else sender_verified_failed != NULL && sender_verified_failed->message != NULL) { - smtp_respond(451, FALSE, sender_verified_failed->message); + smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message); } - smtp_respond(451, TRUE, user_msg); + smtp_respond(smtp_code, codelen, TRUE, user_msg); } else - smtp_printf("451 Temporary local problem - please try later\r\n"); + smtp_respond(smtp_code, codelen, TRUE, + US"Temporary local problem - please try later"); } /* Log the incident. If the connection is not forcibly to be dropped, return 0. -- cgit v1.2.3