From 7102e136b439b6e92317b484192f1357b1e1121a Mon Sep 17 00:00:00 2001
From: Philip Hazel <ph10@hermes.cam.ac.uk>
Date: Tue, 21 Dec 2004 12:21:46 +0000
Subject: [PATCH] Check dnsdb PTR key for IP address before playing the
 reversing game.

---
 doc/doc-txt/ChangeLog   |  7 ++++++-
 doc/doc-txt/NewStuff    |  6 +++++-
 src/src/lookups/dnsdb.c | 10 ++++++----
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 021b61bcc..2b75b4656 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.52 2004/12/21 12:00:59 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.53 2004/12/21 12:21:46 ph10 Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
@@ -234,6 +234,11 @@ Exim version 4.50
       But simultaneously result of request was absolutely normal ldap result,
       so I produce this patch..."
 
+55. Some experimental protocols are using DNS PTR records for new purposes. The
+    keys for these records are domain names, not reversed IP addresses. The
+    dnsdb lookup now tests whether it's key is an IP address. If not, it leaves
+    it alone. Component reversal etc. now happens only for IP addresses.
+
 
 Exim version 4.43
 -----------------
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 3109ea96f..11d7b3cc3 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.21 2004/12/20 15:24:27 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.22 2004/12/21 12:21:46 ph10 Exp $
 
 New Features in Exim
 --------------------
@@ -234,6 +234,10 @@ Version 4.50
 19. The Exiscan patch is now merged into the main source. See src/EDITME for
     parameters for the build.
 
+20. If the key for a dnsdb lookup is not an IP address, it is used verbatim,
+    without component reversal and without the addition of in-addr.arpa or
+    ip6.arpa.
+
 
 Version 4.43
 ------------
diff --git a/src/src/lookups/dnsdb.c b/src/src/lookups/dnsdb.c
index 9cd8612b1..756247d35 100644
--- a/src/src/lookups/dnsdb.c
+++ b/src/src/lookups/dnsdb.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/lookups/dnsdb.c,v 1.6 2004/12/20 15:24:28 ph10 Exp $ */
+/* $Cambridge: exim/src/src/lookups/dnsdb.c,v 1.7 2004/12/21 12:21:46 ph10 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -231,10 +231,12 @@ while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
   int searchtype = (type == T_ZNS)? T_NS :          /* record type we want */
                    (type == T_MXH)? T_MX : type; 
 
-  /* If the type is PTR, we have to construct the relevant magic lookup
-  key. This code is now in a separate function. */
+  /* If the type is PTR, we have to construct the relevant magic lookup key if
+  the original is an IP address (some experimental protocols are using PTR
+  records for different purposes where the key string is a host name). This
+  code for doing the reversal is now in a separate function. */
   
-  if (type == T_PTR)
+  if (type == T_PTR && string_is_ip_address(domain, NULL)) 
     {
     dns_build_reverse(domain, rbuffer);
     domain = rbuffer;
-- 
2.25.1