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-rw-r--r--net/resolvers/basic.lua71
1 files changed, 71 insertions, 0 deletions
diff --git a/net/resolvers/basic.lua b/net/resolvers/basic.lua
new file mode 100644
index 00000000..9a3c9952
--- /dev/null
+++ b/net/resolvers/basic.lua
@@ -0,0 +1,71 @@
+local adns = require "net.adns";
+local inet_pton = require "util.net".pton;
+
+local methods = {};
+local resolver_mt = { __index = methods };
+
+-- Find the next target to connect to, and
+-- pass it to cb()
+function methods:next(cb)
+ if self.targets then
+ if #self.targets == 0 then
+ cb(nil);
+ return;
+ end
+ local next_target = table.remove(self.targets, 1);
+ cb(unpack(next_target, 1, 4));
+ return;
+ end
+
+ local targets = {};
+ local n = 2;
+ local function ready()
+ n = n - 1;
+ if n > 0 then return; end
+ self.targets = targets;
+ self:next(cb);
+ end
+
+ local is_ip = inet_pton(self.hostname);
+ if is_ip then
+ if #is_ip == 16 then
+ cb(self.conn_type.."6", self.hostname, self.port, self.extra);
+ elseif #is_ip == 4 then
+ cb(self.conn_type.."4", self.hostname, self.port, self.extra);
+ end
+ return;
+ end
+
+ -- Resolve DNS to target list
+ local dns_resolver = adns.resolver();
+ dns_resolver:lookup(function (answer)
+ if answer then
+ for _, record in ipairs(answer) do
+ table.insert(targets, { self.conn_type.."4", record.a, self.port, self.extra });
+ end
+ end
+ ready();
+ end, self.hostname, "A", "IN");
+
+ dns_resolver:lookup(function (answer)
+ if answer then
+ for _, record in ipairs(answer) do
+ table.insert(targets, { self.conn_type.."6", record.aaaa, self.port, self.extra });
+ end
+ end
+ ready();
+ end, self.hostname, "AAAA", "IN");
+end
+
+local function new(hostname, port, conn_type, extra)
+ return setmetatable({
+ hostname = hostname;
+ port = port;
+ conn_type = conn_type or "tcp";
+ extra = extra;
+ }, resolver_mt);
+end
+
+return {
+ new = new;
+};