Add recognition of SMTP error codes in bespoke messages.

[exim.git] / src / src / smtp_in.c

diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index 99ac3fb1a3f402f866aa47163ef01c2cf510e2bf..881bfff58793cebd610443338ba2b9da96f09551 100644 (file)
--- 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    *
 
 /*************************************************
 *     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:
 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
 
   final         FALSE if the last line isn't the final line
   msg           message text, possibly containing newlines
 


@@ -1775,26 +1776,36 @@ Returns:        nothing
 */
 
 void
 */
 
 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 (!final && no_multiline_responses) return;
 

+if (codelen > 3)
+  {
+  esc = code + 4;
+  esclen = codelen - 4;
+  }
+

 for (;;)
   {
   uschar *nl = Ustrchr(msg, '\n');
   if (nl == NULL)
     {
 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)
     {
     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
     {
     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++;
     }
     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.
 
 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
 
 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
 smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
 {

-int code = acl_wherecodes[where];

 BOOL drop = rc == FAIL_DROP;
 BOOL drop = rc == FAIL_DROP;

+int codelen = 3;
+int ovector[3];
+uschar *smtp_code;

 uschar *lognl;
 uschar *sender_info = US"";
 uschar *what =
 uschar *lognl;
 uschar *sender_info = US"";
 uschar *what =


@@ -1853,6 +1871,41 @@ uschar *what =
 
 if (drop) rc = FAIL;
 
 
 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
 /* 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)
       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"
         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. */
 
 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,
   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)
       {
         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
     }
   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.
   }
 
 /* Log the incident. If the connection is not forcibly to be dropped, return 0.