A further widen_domains fix for a subtle but common case.

[exim.git] / src / src / routers / dnslookup.c

diff --git a/src/src/routers/dnslookup.c b/src/src/routers/dnslookup.c
index 7789d46363ab9d514f8dc2b13c195ed19397f790..aced23747489f2a6375d4ecf74e593e96e4e5d58 100644 (file)
--- a/src/src/routers/dnslookup.c
+++ b/src/src/routers/dnslookup.c
@@ -1,10 +1,10 @@
-/* $Cambridge: exim/src/src/routers/dnslookup.c,v 1.1 2004/10/07 13:10:02 ph10 Exp $ */
+/* $Cambridge: exim/src/src/routers/dnslookup.c,v 1.6 2005/09/15 16:02:07 fanf2 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2004 */
+/* Copyright (c) University of Cambridge 1995 - 2005 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 #include "../exim.h"
@@ -128,7 +128,7 @@ dnslookup_router_entry(
   router_instance *rblock,        /* data for this instantiation */
   address_item *addr,             /* address we are working on */
   struct passwd *pw,              /* passwd entry after check_local_user */
-  BOOL verify,                    /* TRUE when verifying */
+  int verify,                     /* v_none/v_recipient/v_sender/v_expn */
   address_item **addr_local,      /* add it to this if it's local */
   address_item **addr_remote,     /* add it to this if it's remote */
   address_item **addr_new,        /* put new addresses on here */
@@ -177,9 +177,22 @@ precedence over global names. For example, if the domain is "xxx.ch" it might
 be something in the "ch" toplevel domain, but it also might be xxx.ch.xyz.com.
 The choice of pre- or post-widening affects which takes precedence. If ever
 somebody comes up with some kind of requirement for pre-widening, presumably
-with some conditions under which it is done, it can be selected here. */
-
-if (ob->widen_domains != NULL)
+with some conditions under which it is done, it can be selected here.
+
+The rewrite_headers option works only when routing an address at transport
+time, because the alterations to the headers are not persistent so must be
+worked out immediately before they are used. Sender addresses are routed for
+verification purposes, but never at transport time, so any header changes that
+you might expect as a result of sender domain widening do not occur. Therefore
+we do not perform widening when verifying sender addresses; however, widening
+sender addresses is OK if we do not have to rewrite the headers. A corollary
+of this is that if the current address is not the original address, then it
+does not appear in the message header so it is also OK to widen. The
+suppression of widening for sender addresses is silent because it is the
+normal desirable behaviour. */
+
+if (ob->widen_domains != NULL &&
+    (verify != v_sender || !ob->rewrite_headers || addr->parent != NULL))
   {
   listptr = ob->widen_domains;
   widen = string_nextinlist(&listptr, &widen_sep, widen_buffer,
@@ -300,12 +313,13 @@ for (;;)
 
   if (h.mx >= 0 && h.address == NULL)
     {
+    setflag(addr, af_pass_message);   /* This is not a security risk */
     if (h.name[0] == 0)
       addr->message = US"an SRV record indicated no SMTP service";
     else
       {
       addr->message = US"all relevant MX records point to non-existent hosts";
-      if (!allow_mx_to_ip && string_is_ip_address(h.name, NULL))
+      if (!allow_mx_to_ip && string_is_ip_address(h.name, NULL) > 0)
         {
         addr->user_message =
           string_sprintf("It appears that the DNS operator for %s\n"