aboutsummaryrefslogtreecommitdiffstats
path: root/net/resolvers
diff options
context:
space:
mode:
Diffstat (limited to 'net/resolvers')
-rw-r--r--net/resolvers/basic.lua71
-rw-r--r--net/resolvers/manual.lua25
-rw-r--r--net/resolvers/service.lua70
3 files changed, 166 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;
+};
diff --git a/net/resolvers/manual.lua b/net/resolvers/manual.lua
new file mode 100644
index 00000000..c0d4e5d5
--- /dev/null
+++ b/net/resolvers/manual.lua
@@ -0,0 +1,25 @@
+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 == 0 then
+ cb(nil);
+ return;
+ end
+ local next_target = table.remove(self.targets, 1);
+ cb(unpack(next_target, 1, 4));
+end
+
+local function new(targets, conn_type, extra)
+ return setmetatable({
+ conn_type = conn_type;
+ extra = extra;
+ targets = targets or {};
+ }, resolver_mt);
+end
+
+return {
+ new = new;
+};
diff --git a/net/resolvers/service.lua b/net/resolvers/service.lua
new file mode 100644
index 00000000..b5a2d821
--- /dev/null
+++ b/net/resolvers/service.lua
@@ -0,0 +1,70 @@
+local adns = require "net.adns";
+local basic = require "net.resolvers.basic";
+
+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);
+ self.resolver = basic.new(unpack(next_target, 1, 4));
+ self.resolver:next(function (...)
+ if ... == nil then
+ self:next(cb);
+ else
+ cb(...);
+ end
+ end);
+ return;
+ end
+
+ local targets = {};
+ local function ready()
+ self.targets = targets;
+ self:next(cb);
+ end
+
+ -- Resolve DNS to target list
+ local dns_resolver = adns.resolver();
+ dns_resolver:lookup(function (answer)
+ if answer then
+ if #answer == 0 then
+ if self.extra and self.extra.default_port then
+ table.insert(targets, { self.hostname, self.extra.default_port, self.conn_type, self.extra });
+ end
+ ready();
+ return;
+ end
+
+ if #answer == 1 and answer[1].srv.target == "." then -- No service here
+ ready();
+ return;
+ end
+
+ table.sort(answer, function (a, b) return a.srv.priority < b.srv.priority end);
+ for _, record in ipairs(answer) do
+ table.insert(targets, { record.srv.target, record.srv.port, self.conn_type, self.extra });
+ end
+ end
+ ready();
+ end, "_" .. self.service .. "._" .. self.conn_type .. "." .. self.hostname, "SRV", "IN");
+end
+
+local function new(hostname, service, conn_type, extra)
+ return setmetatable({
+ hostname = hostname;
+ service = service;
+ conn_type = conn_type or "tcp";
+ extra = extra;
+ }, resolver_mt);
+end
+
+return {
+ new = new;
+};