From d90eedf7257d1601e9a1ad77345f06cf9b28b308 Mon Sep 17 00:00:00 2001
From: Matthew Wild <mwild1@gmail.com>
Date: Tue, 14 Dec 2010 18:29:40 +0000
Subject: [PATCH] net.dns: Clean up tostring() of returned records, as a result
 PTR records can now be tostring()'d

---
 net/dns.lua | 39 +++++++++++++++++----------------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/net/dns.lua b/net/dns.lua
index f3d80291..23a453aa 100644
--- a/net/dns.lua
+++ b/net/dns.lua
@@ -21,8 +21,8 @@ local is_windows = (_ and windows) or os.getenv("WINDIR");
 local coroutine, io, math, string, table =
       coroutine, io, math, string, table;
 
-local ipairs, next, pairs, print, setmetatable, tostring, assert, error, unpack, select =
-      ipairs, next, pairs, print, setmetatable, tostring, assert, error, unpack, select;
+local ipairs, next, pairs, print, setmetatable, tostring, assert, error, unpack, select, type=
+      ipairs, next, pairs, print, setmetatable, tostring, assert, error, unpack, select, type;
 
 local ztact = { -- public domain 20080404 lua@ztact.com
 	get = function(parent, ...)
@@ -160,29 +160,24 @@ resolver.timeout = default_timeout;
 
 local SRV_tostring;
 
+local function default_rr_tostring(rr)
+	local rr_val = rr.type and rr[rr.type:lower()];
+	if type(rr_val) ~= "string" then
+		return "<UNKNOWN RDATA TYPE>";
+	end
+	return rr_val;
+end
+
+local special_tostrings = {
+	LOC = resolver.LOC_tostring;
+	MX = function (rr) return string.format('%2i %s', rr.pref, rr.mx); end;
+	SRV = SRV_tostring;
+};
 
 local rr_metatable = {};   -- - - - - - - - - - - - - - - - - - -  rr_metatable
 function rr_metatable.__tostring(rr)
-	local s0 = string.format('%2s %-5s %6i %-28s', rr.class, rr.type, rr.ttl, rr.name);
-	local s1 = '';
-	if rr.type == 'A' then
-		s1 = ' '..rr.a;
-	elseif rr.type == 'MX' then
-		s1 = string.format(' %2i %s', rr.pref, rr.mx);
-	elseif rr.type == 'CNAME' then
-		s1 = ' '..rr.cname;
-	elseif rr.type == 'LOC' then
-		s1 = ' '..resolver.LOC_tostring(rr);
-	elseif rr.type == 'NS' then
-		s1 = ' '..rr.ns;
-	elseif rr.type == 'SRV' then
-		s1 = ' '..SRV_tostring(rr);
-	elseif rr.type == 'TXT' then
-		s1 = ' '..rr.txt;
-	else
-		s1 = ' <UNKNOWN RDATA TYPE>';
-	end
-	return s0..s1;
+	local rr_string = (special_tostrings[rr.type] or default_rr_tostring)(rr);
+	return string.format('%2s %-5s %6i %-28s %s', rr.class, rr.type, rr.ttl, rr.name, rr_string);
 end
 
 
-- 
2.30.2