Apply the fix for widen_domains to qualify_single and search_parents

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

diff --git a/src/src/routers/dnslookup.c b/src/src/routers/dnslookup.c
index 1eb2154126fb5775fe6da446868f2935cd267a12..9a9fba15a4329eb11e703276239d8d57ce96f6e0 100644 (file)
--- a/src/src/routers/dnslookup.c
+++ b/src/src/routers/dnslookup.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/routers/dnslookup.c,v 1.2 2005/01/04 10:00:44 ph10 Exp $ */
+/* $Cambridge: exim/src/src/routers/dnslookup.c,v 1.7 2005/09/19 09:41:37 fanf2 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -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,
@@ -240,10 +253,14 @@ for (;;)
 
   /* Unfortunately, we cannot set the mx_only option in advance, because the
   DNS lookup may extend an unqualified name. Therefore, we must do the test
-  subsequently. */
+  subsequently. We use the same logic as that for widen_domains above to avoid
+  requesting a header rewrite that cannot work. */
 
-  if (ob->qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
-  if (ob->search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
+  if (verify != v_sender || !ob->rewrite_headers || addr->parent != NULL)
+    {
+    if (ob->qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
+    if (ob->search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
+    }
 
   rc = host_find_bydns(&h, rblock->ignore_target_hosts, flags, srv_service,
     ob->srv_fail_domains, ob->mx_fail_domains, &fully_qualified_name, &removed);
@@ -300,12 +317,13 @@ 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"