modules/s_dns: Simplify/breakdown callback stack related.

ircd/net.cc

@@ -2909,7 +2909,7 @@ ircd::net::dns::resolve(const hostport &hp,
                         const opts &op,
                         callback_ipport_one cb)
 {
-	using prototype = void (const hostport &, const opts &, callback_ipport_one);
+	using prototype = void (const hostport &, opts, callback_ipport_one);
 
 	static mods::import<prototype> function
 	{
@@ -2926,7 +2926,7 @@ ircd::net::dns::resolve(const hostport &hp,
                         const opts &op,
                         callback_SRV_one cb)
 {
-	using prototype = void (const hostport &, const opts &, callback_SRV_one);
+	using prototype = void (const hostport &, opts, callback_SRV_one);
 
 	static mods::import<prototype> function
 	{
@@ -2943,7 +2943,7 @@ ircd::net::dns::resolve(const hostport &hp,
                         const opts &op,
                         callback_A_one cb)
 {
-	using prototype = void (const hostport &, const opts &, callback_A_one);
+	using prototype = void (const hostport &, opts, callback_A_one);
 
 	static mods::import<prototype> function
 	{

modules/s_dns.cc

@@ -29,60 +29,58 @@ IRCD_MODULE
 /// intermediate results.
 void
 ircd::net::dns::_resolve_ipport(const hostport &hp,
-                                const opts &opts,
+                                opts opts,
                                 callback_ipport_one callback)
 {
-	//TODO: ip6
+	auto handler
-	auto calluser{[callback(std::move(callback))]
-	(std::exception_ptr eptr, const hostport &hp, const uint32_t &ip)
 	{
-		if(eptr)
+		std::bind(&handle_ipport__A, std::move(callback), ph::_1, ph::_2, ph::_3)
-			return callback(std::move(eptr), hp, {});
-
-		if(!ip)
-		{
-			static const net::not_found no_record
-			{
-				"Host has no A record"
 	};
 
-			return callback(std::make_exception_ptr(no_record), hp, {});
-		}
-
-		const ipport ipport{ip, port(hp)};
-		callback(std::move(eptr), hp, ipport);
-	}};
-
 	if(!hp.service)
-		return _resolve__A(hp, opts, [calluser(std::move(calluser))]
+		return _resolve__A(hp, opts, std::move(handler));
-		(std::exception_ptr eptr, const hostport &hp, const rfc1035::record::A &record)
-		{
-			calluser(std::move(eptr), hp, record.ip4);
-		});
 
-	auto srv_opts{opts};
+	opts.nxdomain_exceptions = false;
-	srv_opts.nxdomain_exceptions = false;
+	_resolve__SRV(hp, opts, [opts(opts), handler(std::move(handler))]
-	_resolve__SRV(hp, srv_opts, [opts(opts), calluser(std::move(calluser))]
 	(std::exception_ptr eptr, hostport hp, const rfc1035::record::SRV &record)
 	mutable
 	{
 		if(eptr)
-			return calluser(std::move(eptr), hp, 0);
-
-		if(record.port != 0)
-			hp.port = record.port;
-
-		hp.host = record.tgt?: unmake_SRV_key(hp.host);
-		opts.qtype = 0;
-
-		_resolve__A(hp, opts, [calluser(std::move(calluser))]
-		(std::exception_ptr eptr, const hostport &hp, const rfc1035::record::A &record)
 		{
-			calluser(std::move(eptr), hp, record.ip4);
+			static const rfc1035::record::A empty;
-		});
+			return handler(std::move(eptr), hp, empty);
+		}
+
+		opts.qtype = 0;
+		opts.nxdomain_exceptions = true;
+		hp.host = record.tgt?: unmake_SRV_key(hp.host);
+		hp.port = record.port? record.port : hp.port;
+		_resolve__A(hp, opts, std::move(handler));
 	});
 }
 
+void
+ircd::net::dns::handle_ipport__A(callback_ipport_one callback,
+                                 std::exception_ptr eptr,
+                                 const hostport &hp,
+                                 const rfc1035::record::A &record)
+{
+	static const ircd::net::not_found no_record
+	{
+		"Host has no A record"
+	};
+
+	if(!eptr && !record.ip4)
+		eptr = std::make_exception_ptr(no_record);
+
+	const ipport ipport
+	{
+		record.ip4, port(hp)
+	};
+
+	callback(std::move(eptr), hp, ipport);
+}
+
 /// Convenience callback with a single SRV record which was selected from
 /// the vector with stochastic respect for weighting and priority.
 void
@@ -106,8 +104,19 @@ ircd::net::dns::_resolve__SRV(const hostport &hp,
 	if(!opts.qtype)
 		opts.qtype = qtype;
 
-	_resolve__(hp, opts, [callback(std::move(callback))]
+	auto handler
-	(std::exception_ptr eptr, const hostport &hp, const vector_view<const rfc1035::record *> rrs)
+	{
+		std::bind(&handle__SRV, std::move(callback), ph::_1, ph::_2, ph::_3)
+	};
+
+	_resolve__(hp, opts, std::move(handler));
+}
+
+void
+ircd::net::dns::handle__SRV(callback_SRV_one callback,
+                            std::exception_ptr eptr,
+                            const hostport &hp,
+                            const records &rrs)
 {
 	static const rfc1035::record::SRV empty;
 
@@ -126,7 +135,6 @@ ircd::net::dns::_resolve__SRV(const hostport &hp,
 	}
 
 	return callback(std::move(eptr), hp, empty);
-	});
 }
 
 /// Convenience callback with a single A record which was selected from
@@ -152,8 +160,19 @@ ircd::net::dns::_resolve__A(const hostport &hp,
 	if(!opts.qtype)
 		opts.qtype = qtype;
 
-	_resolve__(hp, opts, [callback(std::move(callback))]
+	auto handler
-	(std::exception_ptr eptr, const hostport &hp, const vector_view<const rfc1035::record *> &rrs)
+	{
+		std::bind(&handle__A, std::move(callback), ph::_1, ph::_2, ph::_3)
+	};
+
+	_resolve__(hp, opts, std::move(handler));
+}
+
+void
+ircd::net::dns::handle__A(callback_A_one callback,
+                          std::exception_ptr eptr,
+                          const hostport &hp,
+                          const records &rrs)
 {
 	static const rfc1035::record::A empty;
 
@@ -172,7 +191,6 @@ ircd::net::dns::_resolve__A(const hostport &hp,
 	}
 
 	return callback(std::move(eptr), hp, empty);
-	});
 }
 
 /// Fundamental callback with a vector of abstract resource records.

modules/s_dns.h

@@ -16,10 +16,14 @@ namespace ircd::net::dns
 	// Maximum number of records we present in result vector to any closure
 	constexpr const size_t MAX_COUNT {64};
 
+	static void handle__A(callback_A_one, std::exception_ptr, const hostport &, const records &);
+	static void handle__SRV(callback_SRV_one, std::exception_ptr, const hostport &, const records &);
+	static void handle_ipport__A(callback_ipport_one, std::exception_ptr, const hostport &, const rfc1035::record::A &);
+
 	extern "C" void _resolve__(const hostport &, const opts &, callback);
 	extern "C" void _resolve__A(const hostport &, opts, callback_A_one);
 	extern "C" void _resolve__SRV(const hostport &, opts, callback_SRV_one);
-	extern "C" void _resolve_ipport(const hostport &, const opts &, callback_ipport_one);
+	extern "C" void _resolve_ipport(const hostport &, opts, callback_ipport_one);
 }
 
 //