net.dns: Support for resolving AAAA records

[prosody.git] / net / dns.lua

diff --git a/net/dns.lua b/net/dns.lua
index f3d802919b9ae7dbeee77c8f6e7867395c117092..3f1cb4f687ffc917b53e2ca5dfadc7aba65082ca 100644 (file)
--- 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, ...)
@@ -158,31 +158,29 @@ resolver.__index = resolver;
 
 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 = function (rr)
+               local s = rr.srv;
+               return string.format('%5d %5d %5d %s', s.priority, s.weight, s.port, s.target);
+       end;
+};
 
 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
 
 
@@ -391,6 +389,14 @@ function resolver:A(rr)    -- - - - - - - - - - - - - - - - - - - - - - - -  A
        rr.a = string.format('%i.%i.%i.%i', b1, b2, b3, b4);
 end
 
+function resolver:AAAA(rr)
+       local addr = {};
+       for i = 1, rr.rdlength, 2 do
+               local b1, b2 = self:byte(2);
+               table.insert(addr, ("%02x%02x"):format(b1, b2));
+       end
+       rr.aaaa = table.concat(addr, ":");
+end
 
 function resolver:CNAME(rr)    -- - - - - - - - - - - - - - - - - - - -  CNAME
        rr.cname = self:name();
@@ -480,14 +486,8 @@ function resolver:PTR(rr)
        rr.ptr = self:name();
 end
 
-function SRV_tostring(rr)    -- - - - - - - - - - - - - - - - - - SRV_tostring
-       local s = rr.srv;
-       return string.format( '%5d %5d %5d %s', s.priority, s.weight, s.port, s.target );
-end
-
-
 function resolver:TXT(rr)    -- - - - - - - - - - - - - - - - - - - - - -  TXT
-       rr.txt = self:sub (rr.rdlength);
+       rr.txt = self:sub (self:byte());
 end
 
 
@@ -607,7 +607,11 @@ function resolver:getsocket(servernum)    -- - - - - - - - - - - - - getsocket
        local sock = self.socket[servernum];
        if sock then return sock; end
 
-       sock = socket.udp();
+       local err;
+       sock, err = socket.udp();
+       if not sock then
+               return nil, err;
+       end
        if self.socket_wrapper then sock = self.socket_wrapper(sock, self); end
        sock:settimeout(0);
        -- todo: attempt to use a random port, fallback to 0
@@ -723,7 +727,10 @@ function resolver:query(qname, qtype, qclass)    -- - - - - - - - - - -- query
                --set(self.yielded, co, qclass, qtype, qname, true);
        end
 
-       local conn = self:getsocket(o.server)
+       local conn, err = self:getsocket(o.server)
+       if not conn then
+               return nil, err;
+       end
        conn:send (o.packet)
        
        if timer and self.timeout then
@@ -735,16 +742,18 @@ function resolver:query(qname, qtype, qclass)    -- - - - - - - - - - -- query
                                        i = i + 1;
                                        self:servfail(conn);
                                        o.server = self.best_server;
-                                       conn = self:getsocket(o.server);
-                                       conn:send(o.packet);
-                                       return self.timeout;
-                               else
-                                       -- Tried everything, failed
-                                       self:cancel(qclass, qtype, qname, co, true);
+                                       conn, err = self:getsocket(o.server);
+                                       if conn then
+                                               conn:send(o.packet);
+                                               return self.timeout;
+                                       end
                                end
+                               -- Tried everything, failed
+                               self:cancel(qclass, qtype, qname, co, true);
                        end
                end)
        end
+       return true;
 end
 
 function resolver:servfail(sock)