Multicast bindings (#57)

Co-authored-by: jthomas <jthomas-dev@protonmail.com>

README.md

@@ -96,7 +96,8 @@ Creates a new socket instance.
 Available `options`:
 ```js
 {
-  ipv6Only: false
+  ipv6Only: false,
+  reuseAddress: false
 }
 ```
 

binding.c

@@ -912,6 +912,39 @@ udx_napi_socket_set_ttl (napi_env env, napi_callback_info info) {
   return NULL;
 }
 
+napi_value
+udx_napi_socket_set_membership (napi_env env, napi_callback_info info) {
+  napi_value argv[4];
+  size_t argc = 4;
+
+  napi_get_cb_info(env, info, &argc, argv, NULL, NULL);
+
+  udx_socket_t *socket;
+  size_t socket_len;
+  napi_get_buffer_info(env, argv[0], (void **) &socket, &socket_len);
+
+  char mcast_addr[INET6_ADDRSTRLEN];
+  size_t mcast_addr_len;
+  napi_get_value_string_utf8(env, argv[1], mcast_addr, INET6_ADDRSTRLEN, &mcast_addr_len);
+
+  char iface_addr[INET6_ADDRSTRLEN];
+  size_t iface_addr_len;
+  napi_get_value_string_utf8(env, argv[2], iface_addr, INET6_ADDRSTRLEN, &iface_addr_len);
+
+  char *iface_param = iface_addr_len > 0 ? iface_addr : NULL;
+
+  bool join; // true for join, false for leave
+  napi_get_value_bool(env, argv[3], &join);
+
+  int err = udx_socket_set_membership(socket, mcast_addr, iface_param, join ? UV_JOIN_GROUP : UV_LEAVE_GROUP);
+  if (err < 0) {
+    napi_throw_error(env, uv_err_name(err), uv_strerror(err));
+    return NULL;
+  }
+
+  return NULL;
+}
+
 napi_value
 udx_napi_socket_get_recv_buffer_size (napi_env env, napi_callback_info info) {
   napi_value argv[1];
@@ -1776,6 +1809,10 @@ napi_macros_init (napi_env env, napi_value exports) {
   napi_create_uint32(env, UV_UDP_IPV6ONLY, &UV_UDP_IPV6ONLY_uint32);
   napi_set_named_property(env, exports, "UV_UDP_IPV6ONLY", UV_UDP_IPV6ONLY_uint32);
 
+  napi_value UV_UDP_REUSEADDR_uint32;
+  napi_create_uint32(env, UV_UDP_REUSEADDR, &UV_UDP_REUSEADDR_uint32);
+  napi_set_named_property(env, exports, "UV_UDP_REUSEADDR", UV_UDP_REUSEADDR_uint32);
+
   napi_value inflight_offsetof;
   napi_create_uint32(env, offsetof(udx_stream_t, inflight), &inflight_offsetof);
   napi_set_named_property(env, exports, "offsetof_udx_stream_t_inflight", inflight_offsetof);
@@ -1920,6 +1957,10 @@ napi_macros_init (napi_env env, napi_value exports) {
   napi_create_function(env, NULL, 0, udx_napi_socket_set_send_buffer_size, NULL, &udx_napi_socket_set_send_buffer_size_fn);
   napi_set_named_property(env, exports, "udx_napi_socket_set_send_buffer_size", udx_napi_socket_set_send_buffer_size_fn);
 
+  napi_value udx_napi_socket_set_membership_fn;
+  napi_create_function(env, NULL, 0, udx_napi_socket_set_membership, NULL, &udx_napi_socket_set_membership_fn);
+  napi_set_named_property(env, exports, "udx_napi_socket_set_membership", udx_napi_socket_set_membership_fn);
+
   napi_value udx_napi_socket_send_ttl_fn;
   napi_create_function(env, NULL, 0, udx_napi_socket_send_ttl, NULL, &udx_napi_socket_send_ttl_fn);
   napi_set_named_property(env, exports, "udx_napi_socket_send_ttl", udx_napi_socket_send_ttl_fn);

lib/socket.js

@@ -14,6 +14,7 @@ module.exports = class UDXSocket extends events.EventEmitter {
     this._host = null
     this._family = 0
     this._ipv6Only = opts.ipv6Only === true
+    this._reuseAddress = opts.reuseAddress === true
     this._port = 0
     this._reqs = []
     this._free = []
@@ -75,6 +76,7 @@ module.exports = class UDXSocket extends events.EventEmitter {
       streams: this.streams.size,
       address: this.address(),
       ipv6Only: this._ipv6Only,
+      reuseAddress: this._reuseAddress,
       idle: this.idle,
       busy: this.busy
     }
@@ -161,6 +163,7 @@ module.exports = class UDXSocket extends events.EventEmitter {
 
     let flags = 0
     if (this._ipv6Only) flags |= binding.UV_UDP_IPV6ONLY
+    if (this._reuseAddress) flags |= binding.UV_UDP_REUSEADDR
 
     let family
 
@@ -240,6 +243,16 @@ module.exports = class UDXSocket extends events.EventEmitter {
     return binding.udx_napi_socket_set_send_buffer_size(this._handle, size)
   }
 
+  addMembership (group, ifaceAddress = '') {
+    if (!this._inited) throw new Error('Socket not active')
+    return binding.udx_napi_socket_set_membership(this._handle, group, ifaceAddress, true)
+  }
+
+  dropMembership (group, ifaceAddress = '') {
+    if (!this._inited) throw new Error('Socket not active')
+    return binding.udx_napi_socket_set_membership(this._handle, group, ifaceAddress, false)
+  }
+
   async send (buffer, port, host, ttl) {
     if (this.closing) return false
 

test/socket.js

@@ -74,6 +74,44 @@ test('simple message ipv6', async function (t) {
   await a.send(b4a.from('hello'), a.address().port, '::1')
 })
 
+test('simple multicast message ipv4', async function (t) {
+  t.plan(3)
+  const u = new UDX()
+  const a = createSocket(t, u, { reuseAddress: true })
+
+  a.on('message', function (message, { host, family, port }) {
+    t.alike(message, b4a.from('hello'))
+    t.is(family, 4)
+    t.is(port, a.address().port)
+    a.dropMembership('239.1.1.1')
+    a.close()
+  })
+
+  a.bind(0, '0.0.0.0')
+  a.addMembership('239.1.1.1')
+
+  await (a.send(b4a.from('hello'), a.address().port, '239.1.1.1'))
+})
+
+test.skip('simple multicast message ipv6', async function (t) {
+  t.plan(3)
+  const u = new UDX()
+  const a = createSocket(t, u, { reuseAddress: true })
+
+  a.on('message', function (message, { host, family, port }) {
+    t.alike(message, b4a.from('hello'))
+    t.is(family, 6)
+    t.is(port, a.address().port)
+    a.dropMembership('ff12::f')
+    a.close()
+  })
+
+  a.bind(0, '::')
+  a.addMembership('ff12::f')
+
+  await (a.send(b4a.from('hello'), a.address().port, 'ff12::f'))
+})
+
 test('empty message', async function (t) {
   t.plan(1)