net: add new options to net.Socket and net.Server

PR-URL: #41310
Backport-PR-URL: #42298
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/http.md

@@ -2851,6 +2851,16 @@ changes:
     [`--max-http-header-size`][] for requests received by this server, i.e.
     the maximum length of request headers in bytes.
     **Default:** 16384 (16 KB).
+  * `noDelay` {boolean} If set to `true`, it disables the use of Nagle's
+    algorithm immediately after a new incoming connection is received.
+    **Default:** `false`.
+  * `keepAlive` {boolean} If set to `true`, it enables keep-alive functionality
+    on the socket immediately after a new incoming connection is received,
+    similarly on what is done in \[`socket.setKeepAlive([enable][, initialDelay])`]\[`socket.setKeepAlive(enable, initialDelay)`].
+    **Default:** `false`.
+  * `keepAliveInitialDelay` {number} If set to a positive number, it sets the
+    initial delay before the first keepalive probe is sent on an idle socket.
+    **Default:** `0`.
 
 * `requestListener` {Function}
 
@@ -3092,6 +3102,8 @@ changes:
 * `callback` {Function}
 * Returns: {http.ClientRequest}
 
+`options` in [`socket.connect()`][] are also supported.
+
 Node.js maintains several connections per server to make HTTP requests.
 This function allows one to transparently issue requests.
 

doc/api/net.md

@@ -826,6 +826,14 @@ For TCP connections, available `options` are:
   `0` indicates that both IPv4 and IPv6 addresses are allowed. **Default:** `0`.
 * `hints` {number} Optional [`dns.lookup()` hints][].
 * `lookup` {Function} Custom lookup function. **Default:** [`dns.lookup()`][].
+* `noDelay` {boolean} If set to `true`, it disables the use of Nagle's algorithm immediately
+  after the socket is established. **Default:** `false`.
+* `keepAlive` {boolean} If set to `true`, it enables keep-alive functionality on the socket
+  immediately after the connection is established, similarly on what is done in
+  [`socket.setKeepAlive([enable][, initialDelay])`][`socket.setKeepAlive(enable, initialDelay)`].
+  **Default:** `false`.
+* `keepAliveInitialDelay` {number} If set to a positive number, it sets the initial delay before
+  the first keepalive probe is sent on an idle socket.**Default:** `0`.
 
 For [IPC][] connections, available `options` are:
 
@@ -1381,8 +1389,18 @@ added: v0.5.0
     **Default:** `false`.
   * `pauseOnConnect` {boolean} Indicates whether the socket should be
     paused on incoming connections. **Default:** `false`.
+  * `noDelay` {boolean} If set to `true`, it disables the use of Nagle's algorithm immediately
+    after a new incoming connection is received. **Default:** `false`.
+  * `keepAlive` {boolean} If set to `true`, it enables keep-alive functionality on the socket
+    immediately after a new incoming connection is received, similarly on what is done in
+    [`socket.setKeepAlive([enable][, initialDelay])`][`socket.setKeepAlive(enable, initialDelay)`].
+    **Default:** `false`.
+  * `keepAliveInitialDelay` {number} If set to a positive number, it sets the initial delay before
+    the first keepalive probe is sent on an idle socket.**Default:** `0`.
+
 * `connectionListener` {Function} Automatically set as a listener for the
   [`'connection'`][] event.
+
 * Returns: {net.Server}
 
 Creates a new TCP or [IPC][] server.
@@ -1548,6 +1566,7 @@ net.isIPv6('fhqwhgads'); // returns false
 [`socket.pause()`]: #socketpause
 [`socket.resume()`]: #socketresume
 [`socket.setEncoding()`]: #socketsetencodingencoding
+[`socket.setKeepAlive(enable, initialDelay)`]: #socketsetkeepaliveenable-initialdelay
 [`socket.setTimeout()`]: #socketsettimeouttimeout-callback
 [`socket.setTimeout(timeout)`]: #socketsettimeouttimeout-callback
 [`writable.destroy()`]: stream.md#writabledestroyerror

lib/_http_server.js

@@ -380,7 +380,11 @@ function Server(options, requestListener) {
   }
 
   storeHTTPOptions.call(this, options);
-  net.Server.call(this, { allowHalfOpen: true });
+  net.Server.call(
+    this,
+    { allowHalfOpen: true, noDelay: options.noDelay,
+      keepAlive: options.keepAlive,
+      keepAliveInitialDelay: options.keepAliveInitialDelay });
 
   if (requestListener) {
     this.on('request', requestListener);

lib/net.js

@@ -279,6 +279,8 @@ function initSocketHandle(self) {
 const kBytesRead = Symbol('kBytesRead');
 const kBytesWritten = Symbol('kBytesWritten');
 const kSetNoDelay = Symbol('kSetNoDelay');
+const kSetKeepAlive = Symbol('kSetKeepAlive');
+const kSetKeepAliveInitialDelay = Symbol('kSetKeepAliveInitialDelay');
 
 function Socket(options) {
   if (!(this instanceof Socket)) return new Socket(options);
@@ -297,6 +299,15 @@ function Socket(options) {
       'is not supported'
     );
   }
+  if (typeof options?.keepAliveInitialDelay !== 'undefined') {
+    validateNumber(
+      options?.keepAliveInitialDelay, 'options.keepAliveInitialDelay'
+    );
+
+    if (options.keepAliveInitialDelay < 0) {
+      options.keepAliveInitialDelay = 0;
+    }
+  }
 
   this.connecting = false;
   // Problem with this is that users can supply their own handle, that may not
@@ -307,7 +318,6 @@ function Socket(options) {
   this[kHandle] = null;
   this._parent = null;
   this._host = null;
-  this[kSetNoDelay] = false;
   this[kLastWriteQueueSize] = 0;
   this[kTimeout] = null;
   this[kBuffer] = null;
@@ -381,6 +391,10 @@ function Socket(options) {
     this[kBufferCb] = onread.callback;
   }
 
+  this[kSetNoDelay] = Boolean(options.noDelay);
+  this[kSetKeepAlive] = Boolean(options.keepAlive);
+  this[kSetKeepAliveInitialDelay] = ~~(options.keepAliveInitialDelay / 1000);
+
   // Shut down the socket when we're finished with it.
   this.on('end', onReadableStreamEnd);
 
@@ -503,31 +517,38 @@ Socket.prototype._onTimeout = function() {
 
 
 Socket.prototype.setNoDelay = function(enable) {
+  // Backwards compatibility: assume true when `enable` is omitted
+  enable = Boolean(enable === undefined ? true : enable);
+
   if (!this._handle) {
-    this.once('connect',
-              enable ? this.setNoDelay : () => this.setNoDelay(enable));
+    this[kSetNoDelay] = enable;
     return this;
   }
 
-  // Backwards compatibility: assume true when `enable` is omitted
-  const newValue = enable === undefined ? true : !!enable;
-  if (this._handle.setNoDelay && newValue !== this[kSetNoDelay]) {
-    this[kSetNoDelay] = newValue;
-    this._handle.setNoDelay(newValue);
+  if (this._handle.setNoDelay && enable !== this[kSetNoDelay]) {
+    this[kSetNoDelay] = enable;
+    this._handle.setNoDelay(enable);
   }
 
   return this;
 };
 
 
-Socket.prototype.setKeepAlive = function(setting, msecs) {
+Socket.prototype.setKeepAlive = function(enable, initialDelayMsecs) {
+  enable = Boolean(enable);
+  const initialDelay = ~~(initialDelayMsecs / 1000);
+
   if (!this._handle) {
-    this.once('connect', () => this.setKeepAlive(setting, msecs));
+    this[kSetKeepAlive] = enable;
+    this[kSetKeepAliveInitialDelay] = initialDelay;
     return this;
   }
 
-  if (this._handle.setKeepAlive)
-    this._handle.setKeepAlive(setting, ~~(msecs / 1000));
+  if (this._handle.setKeepAlive && enable !== this[kSetKeepAlive]) {
+    this[kSetKeepAlive] = enable;
+    this[kSetKeepAliveInitialDelay] = initialDelay;
+    this._handle.setKeepAlive(enable, initialDelay);
+  }
 
   return this;
 };
@@ -1140,6 +1161,14 @@ function afterConnect(status, handle, req, readable, writable) {
     }
     self._unrefTimer();
 
+    if (self[kSetNoDelay] && self._handle.setNoDelay) {
+      self._handle.setNoDelay(true);
+    }
+
+    if (self[kSetKeepAlive] && self._handle.setKeepAlive) {
+      self._handle.setKeepAlive(true, self[kSetKeepAliveInitialDelay]);
+    }
+
     self.emit('connect');
     self.emit('ready');
 
@@ -1203,6 +1232,15 @@ function Server(options, connectionListener) {
   } else {
     throw new ERR_INVALID_ARG_TYPE('options', 'Object', options);
   }
+  if (typeof options.keepAliveInitialDelay !== 'undefined') {
+    validateNumber(
+      options.keepAliveInitialDelay, 'options.keepAliveInitialDelay'
+    );
+
+    if (options.keepAliveInitialDelay < 0) {
+      options.keepAliveInitialDelay = 0;
+    }
+  }
 
   this._connections = 0;
 
@@ -1214,6 +1252,9 @@ function Server(options, connectionListener) {
 
   this.allowHalfOpen = options.allowHalfOpen || false;
   this.pauseOnConnect = !!options.pauseOnConnect;
+  this.noDelay = Boolean(options.noDelay);
+  this.keepAlive = Boolean(options.keepAlive);
+  this.keepAliveInitialDelay = ~~(options.keepAliveInitialDelay / 1000);
 }
 ObjectSetPrototypeOf(Server.prototype, EventEmitter.prototype);
 ObjectSetPrototypeOf(Server, EventEmitter);
@@ -1565,6 +1606,14 @@ function onconnection(err, clientHandle) {
     writable: true
   });
 
+  if (self.noDelay && handle.setNoDelay) {
+    handle.setNoDelay(true);
+  }
+
+  if (self.keepAlive && self.setKeepAlive) {
+    handle.setKeepAlive(true, handle.keepAliveInitialDelay);
+  }
+
   self._connections++;
   socket.server = self;
   socket._server = self;

test/parallel/test-net-connect-keepalive.js

@@ -0,0 +1,56 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+
+const truthyValues = [true, 1, 'true', {}, []];
+const delays = [[123, 0], [456123, 456], [-123000, 0], [undefined, 0]];
+const falseyValues = [false, 0, ''];
+
+const genSetKeepAlive = (desiredEnable, desiredDelay) => (enable, delay) => {
+  assert.strictEqual(enable, desiredEnable);
+  assert.strictEqual(delay, desiredDelay);
+};
+
+for (const value of truthyValues) {
+  for (const delay of delays) {
+    const server = net.createServer();
+
+    server.listen(0, common.mustCall(function() {
+      const port = server.address().port;
+
+      const client = net.connect(
+        { port, keepAlive: value, keepAliveInitialDelay: delay[0] },
+        common.mustCall(() => client.end())
+      );
+
+      client._handle.setKeepAlive = common.mustCall(
+        genSetKeepAlive(true, delay[1])
+      );
+
+      client.on('end', common.mustCall(function() {
+        server.close();
+      }));
+    }));
+  }
+}
+
+for (const value of falseyValues) {
+  const server = net.createServer();
+
+  server.listen(0, common.mustCall(function() {
+    const port = server.address().port;
+
+    const client = net.connect(
+      { port, keepAlive: value },
+      common.mustCall(() => client.end())
+    );
+
+    client._handle.setKeepAlive = common.mustNotCall();
+
+    client.on('end', common.mustCall(function() {
+      server.close();
+    }));
+  }));
+}

test/parallel/test-net-connect-nodelay.js

@@ -0,0 +1,49 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+
+const truthyValues = [true, 1, 'true', {}, []];
+const falseyValues = [false, 0, ''];
+const genSetNoDelay = (desiredArg) => (enable) => {
+  assert.strictEqual(enable, desiredArg);
+};
+
+for (const value of truthyValues) {
+  const server = net.createServer();
+
+  server.listen(0, common.mustCall(function() {
+    const port = server.address().port;
+
+    const client = net.connect(
+      { port, noDelay: value },
+      common.mustCall(() => client.end())
+    );
+
+    client._handle.setNoDelay = common.mustCall(genSetNoDelay(true));
+
+    client.on('end', common.mustCall(function() {
+      server.close();
+    }));
+  }));
+}
+
+for (const value of falseyValues) {
+  const server = net.createServer();
+
+  server.listen(0, common.mustCall(function() {
+    const port = server.address().port;
+
+    const client = net.connect(
+      { port, noDelay: value },
+      common.mustCall(() => client.end())
+    );
+
+    client._handle.setNoDelay = common.mustNotCall();
+
+    client.on('end', common.mustCall(function() {
+      server.close();
+    }));
+  }));
+}