Mercurial > prosody-hg

comparison net/dns.lua @ 11200:bf8f2da84007

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Merge 0.11->trunk
author Kim Alvefur <zash@zash.se>
date Thu, 05 Nov 2020 22:31:25 +0100
parents 540f1bc5f082
children 05c250fa335a
comparison
equal deleted inserted replaced
11199:6c7c50a4de32 11200:bf8f2da84007
11 -- reference: http://tools.ietf.org/html/rfc1035 11 -- reference: http://tools.ietf.org/html/rfc1035
12 -- reference: http://tools.ietf.org/html/rfc1876 (LOC) 12 -- reference: http://tools.ietf.org/html/rfc1876 (LOC)
13 13
14 14
15 local socket = require "socket"; 15 local socket = require "socket";
16 local timer = require "util.timer"; 16 local have_timer, timer = pcall(require, "util.timer");
17 local new_ip = require "util.ip".new_ip; 17 local new_ip = require "util.ip".new_ip;
18 local have_util_net, util_net = pcall(require, "util.net"); 18 local have_util_net, util_net = pcall(require, "util.net");
19
20 local log = require "util.logger".init("dns");
19 21
20 local _, windows = pcall(require, "util.windows"); 22 local _, windows = pcall(require, "util.windows");
21 local is_windows = (_ and windows) or os.getenv("WINDIR"); 23 local is_windows = (_ and windows) or os.getenv("WINDIR");
22 24
23 local coroutine, io, math, string, table = 25 local coroutine, io, math, string, table =
67 end 69 end
68 end; 70 end;
69 }; 71 };
70 local get, set = ztact.get, ztact.set; 72 local get, set = ztact.get, ztact.set;
71 73
72 local default_timeout = 15; 74 local default_timeout = 5;
75 local default_jitter = 1;
76 local default_retry_jitter = 2;
73 77
74 -------------------------------------------------- module dns 78 -------------------------------------------------- module dns
75 local _ENV = nil; 79 local _ENV = nil;
76 -- luacheck: std none 80 -- luacheck: std none
77 local dns = {}; 81 local dns = {};
662 666
663 667
664 -- socket layer -------------------------------------------------- socket layer 668 -- socket layer -------------------------------------------------- socket layer
665 669
666 670
667 resolver.delays = { 1, 3 }; 671 resolver.delays = { 1, 2, 3, 5 };
668 672
673 resolver.jitter = have_timer and default_jitter or nil;
674 resolver.retry_jitter = have_timer and default_retry_jitter or nil;
669 675
670 function resolver:addnameserver(address) -- - - - - - - - - - addnameserver 676 function resolver:addnameserver(address) -- - - - - - - - - - addnameserver
671 self.server = self.server or {}; 677 self.server = self.server or {};
672 append(self.server, address); 678 append(self.server, address);
673 end 679 end
851 --print ('query id', id, qclass, qtype, qname) 857 --print ('query id', id, qclass, qtype, qname)
852 local o = { 858 local o = {
853 packet = header..question, 859 packet = header..question,
854 server = self.best_server, 860 server = self.best_server,
855 delay = 1, 861 delay = 1,
856 retry = socket.gettime() + self.delays[1] 862 retry = socket.gettime() + self.delays[1];
863 qclass = qclass;
864 qtype = qtype;
865 qname = qname;
857 }; 866 };
858 867
859 -- remember the query 868 -- remember the query
860 self.active[id] = self.active[id] or {}; 869 self.active[id] = self.active[id] or {};
861 self.active[id][question] = o; 870 self.active[id][question] = o;
862 871
863 local conn, err = self:getsocket(o.server) 872 local conn, err = self:getsocket(o.server)
864 if not conn then 873 if not conn then
865 return nil, err; 874 return nil, err;
866 end 875 end
867 conn:send (o.packet) 876 if self.jitter then
877 timer.add_task(math.random()*self.jitter, function ()
878 conn:send(o.packet);
879 end);
880 else
881 conn:send(o.packet);
882 end
868 883
869 -- remember which coroutine wants the answer 884 -- remember which coroutine wants the answer
870 if co then 885 if co then
871 set(self.wanted, qclass, qtype, qname, co, true); 886 set(self.wanted, qclass, qtype, qname, co, true);
872 end 887 end
873 888
874 if timer and self.timeout then 889 if have_timer and self.timeout then
875 local num_servers = #self.server; 890 local num_servers = #self.server;
876 local i = 1; 891 local i = 1;
877 timer.add_task(self.timeout, function () 892 timer.add_task(self.timeout, function ()
878 if get(self.wanted, qclass, qtype, qname, co) then 893 if get(self.wanted, qclass, qtype, qname, co) then
879 if i < num_servers then 894 log("debug", "DNS request timeout %d/%d", i, num_servers)
880 i = i + 1; 895 i = i + 1;
881 self:servfail(conn); 896 self:servfail(self.socket[o.server]);
882 o.server = self.best_server; 897 -- end
883 conn, err = self:getsocket(o.server); 898 end
884 if conn then 899 -- Still outstanding? (i.e. retried)
885 conn:send(o.packet); 900 if get(self.wanted, qclass, qtype, qname, co) then
886 return self.timeout; 901 return self.timeout; -- Then wait
887 end
888 end
889 -- Tried everything, failed
890 self:cancel(qclass, qtype, qname);
891 end 902 end
892 end) 903 end)
893 end 904 end
894 return true; 905 return true;
895 end 906 end
902 -- Socket is dead now 913 -- Socket is dead now
903 sock = self:voidsocket(sock); 914 sock = self:voidsocket(sock);
904 915
905 -- Find all requests to the down server, and retry on the next server 916 -- Find all requests to the down server, and retry on the next server
906 self.time = socket.gettime(); 917 self.time = socket.gettime();
918 log("debug", "servfail %d (of %d)", num, #self.server);
907 for id,queries in pairs(self.active) do 919 for id,queries in pairs(self.active) do
908 for question,o in pairs(queries) do 920 for question,o in pairs(queries) do
909 if o.server == num then -- This request was to the broken server 921 if o.server == num then -- This request was to the broken server
910 o.server = o.server + 1 -- Use next server 922 o.server = o.server + 1 -- Use next server
911 if o.server > #self.server then 923 if o.server > #self.server then
912 o.server = 1; 924 o.server = 1;
913 end 925 end
914 926
915 o.retries = (o.retries or 0) + 1; 927 o.retries = (o.retries or 0) + 1;
916 if o.retries >= #self.server then 928 local retried;
917 --print('timeout'); 929 if o.retries < #self.server then
930 sock, err = self:getsocket(o.server);
931 if sock then
932 retried = true;
933 if self.retry_jitter then
934 local delay = self.delays[((o.retries-1)%#self.delays)+1] + (math.random()*self.retry_jitter);
935 log("debug", "retry %d in %0.2fs", o.retries, delay);
936 timer.add_task(delay, function ()
937 sock:send(o.packet);
938 end);
939 else
940 log("debug", "retry %d (immediate)", o.retries);
941 sock:send(o.packet);
942 end
943 end
944 end
945 if not retried then
946 log("debug", 'tried all servers, giving up');
947 self:cancel(o.qclass, o.qtype, o.qname);
918 queries[question] = nil; 948 queries[question] = nil;
919 else
920 sock, err = self:getsocket(o.server);
921 if sock then sock:send(o.packet); end
922 end 949 end
923 end 950 end
924 end 951 end
925 if next(queries) == nil then 952 if next(queries) == nil then
926 self.active[id] = nil; 953 self.active[id] = nil;
1162 return r; 1189 return r;
1163 end 1190 end
1164 1191
1165 local _resolver = dns.resolver(); 1192 local _resolver = dns.resolver();
1166 dns._resolver = _resolver; 1193 dns._resolver = _resolver;
1194 _resolver.jitter, _resolver.retry_jitter = false, false;
1167 1195
1168 function dns.lookup(...) -- - - - - - - - - - - - - - - - - - - - - lookup 1196 function dns.lookup(...) -- - - - - - - - - - - - - - - - - - - - - lookup
1169 return _resolver:lookup(...); 1197 return _resolver:lookup(...);
1170 end 1198 end
1171 1199