From a10555e79913dfef6785e79001b4c1ccfc0ad957 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Wed, 22 Jan 2014 14:23:02 +0000
Subject: [PATCH] Improve hostname processing.

---
 conf/lua/hfilter.lua | 12 ++++--------
 src/lua/lua_task.c   | 16 +++++++++++++++-
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/conf/lua/hfilter.lua b/conf/lua/hfilter.lua
index 967953157..f0c4748a8 100644
--- a/conf/lua/hfilter.lua
+++ b/conf/lua/hfilter.lua
@@ -134,12 +134,10 @@ local function check_host(task, host, symbol_suffix, eq_ip, eq_host)
     end
     if eq_host then
         eq_host = string.lower(eq_host)
-    else
-        eq_host = ''
     end
 
     if check_fqdn(host) then
-        if eq_host == '' or eq_host ~= host then
+        if not eq_host or (eq_host ~= 'unknown' or eq_host ~= host) then
             task:get_resolver():resolve_a(task:get_session(), task:get_mempool(), host, check_host_cb_a)
         end
     else
@@ -169,9 +167,6 @@ local function hfilter(task)
     
     --HOSTNAME--
     local hostname = task:get_hostname()
-        if hostname and ip and hostname == '[' .. ip .. ']' then
-            hostname = false
-        end
     
     --HELO--
     local helo = task:get_helo()
@@ -218,8 +213,9 @@ local function hfilter(task)
                 break
             end
         end
-    else
-        task:insert_result('HFILTER_HOSTNAME_NOPTR', 1.00)
+        if hostname == 'unknown' then
+        	task:insert_result('HFILTER_HOSTNAME_NOPTR', 1.00)
+    	end
     end
     
     --Insert weight's for HELO or HOSTNAME
diff --git a/src/lua/lua_task.c b/src/lua/lua_task.c
index e653e25d1..6b74bade0 100644
--- a/src/lua/lua_task.c
+++ b/src/lua/lua_task.c
@@ -1070,7 +1070,21 @@ lua_task_get_hostname (lua_State *L)
 
 	if (task) {
 		if (task->hostname != NULL) {
-			lua_pushstring (L, (gchar *)task->hostname);
+			/* Check whether it looks like an IP address */
+			if (*task->hostname == '[') {
+				/*
+				 * From the milter documentation:
+				 *  If the reverse lookup fails or if none of the IP
+				 *  addresses of the resolved host name matches the
+				 *  original IP address, hostname will contain the
+				 *  message sender's IP address enclosed in square
+				 *  brackets (e.g. `[a.b.c.d]')
+				 */
+				lua_pushstring (L, "unknown");
+			}
+			else {
+				lua_pushstring (L, task->hostname);
+			}
 			return 1;
 		}
 	}
-- 
2.39.5