diff options
| -rw-r--r-- | net/adns.lua | 16 | ||||
| -rw-r--r-- | net/dns.lua | 61 |
2 files changed, 67 insertions, 10 deletions
diff --git a/net/adns.lua b/net/adns.lua index 7ee54da3..9438bf45 100644 --- a/net/adns.lua +++ b/net/adns.lua @@ -11,6 +11,7 @@ local dns = require "net.dns"; local log = require "util.logger".init("adns"); +local t_insert, t_remove = table.insert, table.remove; local coroutine, tostring, pcall = coroutine, tostring, pcall; module "adns" @@ -41,13 +42,20 @@ function cancel(handle, call_handler) end end -function new_async_socket(sock) - local newconn = {}; +function new_async_socket(sock, resolver) + local newconn, peername = {}, "<unknown>"; local listener = {}; function listener.incoming(conn, data) dns.feed(sock, data); end - function listener.disconnect() + function listener.disconnect(conn, err) + log("warn", "DNS socket for %s disconnected: %s", peername, err); + local servers = resolver.server; + if resolver.socketset[newconn.handler] == resolver.best_server and resolver.best_server == #servers then + log("error", "Exhausted all %d configured DNS servers, next lookup will try %s again", #servers, servers[1]); + end + + resolver:servfail(conn); -- Let the magic commence end newconn.handler, newconn._socket = server.wrapclient(sock, "dns", 53, listener); if not newconn.handler then @@ -58,7 +66,7 @@ function new_async_socket(sock) end newconn.handler.settimeout = function () end newconn.handler.setsockname = function (_, ...) return sock:setsockname(...); end - newconn.handler.setpeername = function (_, ...) local ret = sock:setpeername(...); _.setsend(sock.send); return ret; end + newconn.handler.setpeername = function (_, ...) peername = (...); local ret = sock:setpeername(...); _.setsend(sock.send); return ret; end newconn.handler.connect = function (_, ...) return sock:connect(...) end newconn.handler.send = function (_, data) _.write(data); return _.sendbuffer(); end return newconn.handler; diff --git a/net/dns.lua b/net/dns.lua index 592471bb..ff07d26e 100644 --- a/net/dns.lua +++ b/net/dns.lua @@ -488,7 +488,7 @@ function resolver:decode (packet, force) -- - - - - - - - - - - - - - decode -- socket layer -------------------------------------------------- socket layer -resolver.delays = { 1, 3, 11, 45 } +resolver.delays = { 1, 3 } function resolver:addnameserver (address) -- - - - - - - - - - addnameserver @@ -529,16 +529,25 @@ function resolver:getsocket (servernum) -- - - - - - - - - - - - - getsocket if sock then return sock end sock = socket.udp () - if self.socket_wrapper then sock = self.socket_wrapper (sock) 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 sock:setsockname ('*', 0) sock:setpeername (self.server[servernum], 53) self.socket[servernum] = sock - self.socketset[sock] = sock + self.socketset[sock] = servernum return sock end +function resolver:voidsocket (sock) + if self.socket[sock] then + self.socketset[self.socket[sock]] = nil + self.socket[sock] = nil + elseif self.socketset[sock] then + self.socket[self.socketset[sock]] = nil + self.socketset[sock] = nil + end +end function resolver:socket_wrapper_set (func) -- - - - - - - socket_wrapper_set self.socket_wrapper = func @@ -612,10 +621,9 @@ function resolver:query (qname, qtype, qclass) -- - - - - - - - - - -- query local header, id = encodeHeader () --print ('query id', id, qclass, qtype, qname) local o = { packet = header..question, - server = 1, + server = self.best_server, delay = 1, retry = socket.gettime () + self.delays[1] } - self:getsocket (o.server):send (o.packet) -- remember the query self.active[id] = self.active[id] or {} @@ -627,9 +635,49 @@ function resolver:query (qname, qtype, qclass) -- - - - - - - - - - -- query set (self.wanted, qclass, qtype, qname, co, true) --set (self.yielded, co, qclass, qtype, qname, true) end + + self:getsocket (o.server):send (o.packet) + end +function resolver:servfail(sock) + -- Resend all queries for this server + + local num = self.socketset[sock] + + -- Socket is dead now + self:voidsocket(sock); + + -- Find all requests to the down server, and retry on the next server + self.time = socket.gettime () + for id,queries in pairs (self.active) do + for question,o in pairs (queries) do + if o.server == num then -- This request was to the broken server + o.server = o.server + 1 -- Use next server + if o.server > #self.server then + o.server = 1 + end + o.retries = (o.retries or 0) + 1; + if o.retries >= #self.server then + --print ('timeout') + queries[question] = nil + else + local _a = self:getsocket(o.server); + if _a then _a:send (o.packet) end + end + end + end + end + + if num == self.best_server then + self.best_server = self.best_server + 1 + if self.best_server > #self.server then + -- Exhausted all servers, try first again + self.best_server = 1 + end + end +end function resolver:receive (rset) -- - - - - - - - - - - - - - - - - receive @@ -832,7 +880,8 @@ function dns.resolver () -- - - - - - - - - - - - - - - - - - - - - resolver -- this function seems to be redundant with resolver.new () - local r = { active = {}, cache = {}, unsorted = {}, wanted = {}, yielded = {} } + local r = { active = {}, cache = {}, unsorted = {}, wanted = {}, yielded = {}, + best_server = 1 } setmetatable (r, resolver) setmetatable (r.cache, cache_metatable) setmetatable (r.unsorted, { __mode = 'kv' }) |