dgram: implement socket.bind({ fd })

dgram: Implement binding an existing `fd`. Allow pass a `fd` property
to `socket.bind()` in dgram.
src: Add `UDPWrap::Open`

PR-URL: https://github.com/nodejs/node/pull/21745
Fixes: https://github.com/nodejs/node/issues/14961
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/test/parallel/test-dgram-create-socket-handle-fd.js b/test/parallel/test-dgram-create-socket-handle-fd.js
new file mode 100644
index 0000000000..ff507b6ec5
--- /dev/null
+++ b/test/parallel/test-dgram-create-socket-handle-fd.js
@@ -0,0 +1,42 @@
+'use strict';
+const common = require('../common');
+if (common.isWindows)
+  common.skip('Does not support binding fd on Windows');
+
+const assert = require('assert');
+const dgram = require('dgram');
+const { UDP } = process.binding('udp_wrap');
+const { TCP, constants } = process.binding('tcp_wrap');
+const _createSocketHandle = dgram._createSocketHandle;
+
+// Return a negative number if the "existing fd" is invalid.
+{
+  const err = _createSocketHandle(common.localhostIPv4, 0, 'udp4', 42);
+  assert(err < 0);
+}
+
+// Return a negative number if the type of fd is not "UDP".
+{
+  // Create a handle with fd.
+  const rawHandle = new UDP();
+  const err = rawHandle.bind(common.localhostIPv4, 0, 0);
+  assert(err >= 0, String(err));
+  assert.notStrictEqual(rawHandle.fd, -1);
+
+  const handle = _createSocketHandle(null, 0, 'udp4', rawHandle.fd);
+  assert(handle instanceof UDP);
+  assert.strictEqual(typeof handle.fd, 'number');
+  assert(handle.fd > 0);
+}
+
+// Create a bound handle.
+{
+  const rawHandle = new TCP(constants.SOCKET);
+  const err = rawHandle.listen();
+  assert(err >= 0, String(err));
+  assert.notStrictEqual(rawHandle.fd, -1);
+
+  const handle = _createSocketHandle(null, 0, 'udp4', rawHandle.fd);
+  assert(handle < 0);
+  rawHandle.close();
+}