Add recognition of SMTP error codes in bespoke messages.

9 files changed, 158 insertions, 62 deletions

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.