local socket = require "socket";
local timer = require "util.timer";
+local new_ip = require "util.ip".new_ip;
local _, windows = pcall(require, "util.windows");
local is_windows = (_ and windows) or os.getenv("WINDIR");
local default_timeout = 15;
-------------------------------------------------- module dns
-module('dns')
-local dns = _M;
+local _ENV = nil;
+local dns = {};
-- dns type & class codes ------------------------------ dns type & class codes
local function prune(rrs, time, soft) -- - - - - - - - - - - - - - - prune
time = time or socket.gettime();
- for i,rr in pairs(rrs) do
+ for i,rr in ipairs(rrs) do
if rr.tod then
-- rr.tod = rr.tod - 50 -- accelerated decripitude
rr.ttl = math.floor(rr.tod - time);
if rr.ttl <= 0 then
+ rrs[rr[rr.type:lower()]] = nil;
table.remove(rrs, i);
return prune(rrs, time, soft); -- Re-iterate
end
elseif soft == 'soft' then -- What is this? I forget!
assert(rr.ttl == 0);
- rrs[i] = nil;
+ rrs[rr[rr.type:lower()]] = nil;
+ table.remove(rrs, i);
end
end
end
local rrs_metatable = {}; -- - - - - - - - - - - - - - - - - - rrs_metatable
function rrs_metatable.__tostring(rrs)
local t = {};
- for i,rr in pairs(rrs) do
+ for i,rr in ipairs(rrs) do
append(t, tostring(rr)..'\n');
end
return table.concat(t);
end
-function resolver:new() -- - - - - - - - - - - - - - - - - - - - - resolver
- local r = { active = {}, cache = {}, unsorted = {} };
- setmetatable(r, resolver);
- setmetatable(r.cache, cache_metatable);
- setmetatable(r.unsorted, { __mode = 'kv' });
- return r;
-end
-
-
-- packet layer -------------------------------------------------- packet layer
function dns.random(...) -- - - - - - - - - - - - - - - - - - - dns.random
- math.randomseed(math.floor(10000*socket.gettime()) % 0x100000000);
+ math.randomseed(math.floor(10000*socket.gettime()) % 0x80000000);
dns.random = math.random;
return dns.random(...);
end
if resolv_conf then
for line in resolv_conf:lines() do
line = line:gsub("#.*$", "")
- :match('^%s*nameserver%s+(.*)%s*$');
+ :match('^%s*nameserver%s+([%x:%.]*)%s*$');
if line then
- line:gsub("%f[%d.](%d+%.%d+%.%d+%.%d+)%f[^%d.]", function (address)
- self:addnameserver(address)
- end);
+ local ip = new_ip(line);
+ if ip then
+ self:addnameserver(ip.addr);
+ end
end
end
end
local sock = self.socket[servernum];
if sock then return sock; end
- local err;
- sock, err = socket.udp();
+ local ok, err;
+ local peer = self.server[servernum];
+ if peer:find(":") then
+ sock, err = socket.udp6();
+ else
+ sock, err = socket.udp();
+ end
if sock and self.socket_wrapper then sock, err = self.socket_wrapper(sock, self); end
if not sock then
return nil, err;
end
sock:settimeout(0);
-- todo: attempt to use a random port, fallback to 0
- sock:setsockname('*', 0);
- sock:setpeername(self.server[servernum], 53);
self.socket[servernum] = sock;
self.socketset[sock] = servernum;
+ -- set{sock,peer}name can fail, eg because of local routing table
+ -- if so, try the next server
+ ok, err = sock:setsockname('*', 0);
+ if not ok then return self:servfail(sock, err); end
+ ok, err = sock:setpeername(peer, 53);
+ if not ok then return self:servfail(sock, err); end
return sock;
end
self.cache = self.cache or setmetatable({}, cache_metatable);
local rrs = get(self.cache, qclass, type, qname) or
set(self.cache, qclass, type, qname, setmetatable({}, rrs_metatable));
- append(rrs, rr);
+ if not rrs[rr[qtype:lower()]] then
+ rrs[rr[qtype:lower()]] = true;
+ append(rrs, rr);
+ end
if type == 'MX' then self.unsorted[rrs] = true; end
end
end
-function resolver:peek (qname, qtype, qclass) -- - - - - - - - - - - - peek
+function resolver:peek (qname, qtype, qclass, n) -- - - - - - - - - - - - peek
qname, qtype, qclass = standardize(qname, qtype, qclass);
local rrs = get(self.cache, qclass, qtype, qname);
- if not rrs then return nil; end
+ if not rrs then
+ if n then if n <= 0 then return end else n = 3 end
+ rrs = get(self.cache, qclass, "CNAME", qname);
+ if not (rrs and rrs[1]) then return end
+ return self:peek(rrs[1].cname, qtype, qclass, n - 1);
+ end
if prune(rrs, socket.gettime()) and qtype == '*' or not next(rrs) then
set(self.cache, qclass, qtype, qname, nil);
return nil;
end
- if self.unsorted[rrs] then table.sort (rrs, comp_mx); end
+ if self.unsorted[rrs] then table.sort (rrs, comp_mx); self.unsorted[rrs] = nil; end
return rrs;
end
return nil, err;
end
conn:send (o.packet)
-
+
if timer and self.timeout then
local num_servers = #self.server;
local i = 1;
return true;
end
-function resolver:servfail(sock)
+function resolver:servfail(sock, err)
-- Resend all queries for this server
local num = self.socketset[sock]
-- Socket is dead now
- self:voidsocket(sock);
+ sock = self:voidsocket(sock);
-- Find all requests to the down server, and retry on the next server
self.time = socket.gettime();
--print('timeout');
queries[question] = nil;
else
- local _a = self:getsocket(o.server);
- if _a then _a:send(o.packet); end
+ sock, err = self:getsocket(o.server);
+ if sock then sock:send(o.packet); end
end
end
end
self.best_server = 1;
end
end
+ return sock, err;
end
function resolver:settimeout(seconds)
-- retire the query
local queries = self.active[response.header.id];
queries[response.question.raw] = nil;
-
+
if not next(queries) then self.active[response.header.id] = nil; end
if not next(self.active) then self:closeall(); end
set(self.wanted, q.class, q.type, q.name, nil);
end
end
-
+
end
end
end
function dns.resolver () -- - - - - - - - - - - - - - - - - - - - - resolver
- -- this function seems to be redundant with resolver.new ()
-
local r = { active = {}, cache = {}, unsorted = {}, wanted = {}, best_server = 1 };
setmetatable (r, resolver);
setmetatable (r.cache, cache_metatable);