s2smanager: Compatibility with domains which use CNAMEs

diff --git a/core/s2smanager.lua b/core/s2smanager.lua
index b42662f3671108f01db9ce2cf94e37e923874337..4113ae608a661e8bab0c88fee8677d5fa45d191d 100644 (file)
--- a/core/s2smanager.lua
+++ b/core/s2smanager.lua
@@ -37,7 +37,7 @@ local sha256_hash = require "util.hashes".sha256;
 
 local dialback_secret = uuid_gen();
 
-local adns = require "net.adns";
+local adns, dns = require "net.adns", require "net.dns";
 
 local dns_timeout = config.get("*", "core", "dns_timeout") or 60;
 
@@ -240,6 +240,16 @@ function try_connect(host_session, connect_host, connect_port)
        handle = adns.lookup(function (reply)
                handle = nil;
                host_session.connecting = nil;
+               
+               -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
+               if not (reply and reply[1] and reply[1].a) then
+                       reply = dns.peek(connect_host, "CNAME", "IN");
+                       while reply and reply[1] and not reply[1].a and reply[1].cname do
+                               reply = dns.peek(reply[1].cname, "A", "IN") or dns.peek(reply[1].cname, "CNAME", "IN");
+                       end
+               end
+               -- end of CNAME resolving
+               
                if reply and reply[1] and reply[1].a then
                        log("debug", "DNS reply for %s gives us %s", connect_host, reply[1].a);
                        return make_connect(host_session, reply[1].a, connect_port);