net: add ability to reset a tcp socket

make it possible to forcibly rest a tcp socket:

* add a new method `Socket.prototype.resetAndDestroy`

* add a new flag `resetAndClosing` to make `_destroy` calls
the `reset` instead of close while destroying a Socket.

* add new methods `TCPWrap::Reset` to be a wrap of `uv_tcp_close_reset`

* change `HandleWrap::state_` from private to protected.
This is essential for keeping the same behaviour between
`TCPWrap::Reset` and `HandleWrap::Close`

Fixes: nodejs#27428

doc/api/net.md

@@ -1089,6 +1089,20 @@ added: v0.5.10
 
 The numeric representation of the remote port. For example, `80` or `21`.
 
+### `socket.resetAndDestroy()`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* Returns: {net.Socket}
+
+Close the TCP connection by sending an RST packet and destroy the stream.
+If this TCP socket is in connecting status, it will send an RST packet and destroy this TCP socket once it is connected.
+Otherwise, it will call `socket.destroy` this socket with an `ERR_SOCKET_CLOSED` Error.
+If this is not a TCP socket (for example, a pipe), calling this method will immediately throw an `ERR_INVALID_HANDLE_TYPE` Error.
+See [`writable.destroy()`][] for further details.
+
 ### `socket.resume()`
 
 * Returns: {net.Socket} The socket itself.

lib/net.js

@@ -642,12 +642,17 @@ Socket.prototype.end = function(data, encoding, callback) {
 };
 
 Socket.prototype.resetAndDestroy = function() {
-  if (!(this._handle instanceof TCP))
-    throw new ERR_INVALID_HANDLE_TYPE();
   if (this._handle) {
-    debug('reset');
-    this.resetAndClosing = true;
-    return this.destroy();
+    if (!(this._handle instanceof TCP))
+      throw new ERR_INVALID_HANDLE_TYPE();
+    if (this.connecting) {
+      debug('reset wait for connection');
+      this.once('connect', () => this._reset());
+    } else {
+      this._reset();
+    }
+  } else {
+    this.destroy(new ERR_SOCKET_CLOSED());
   }
   return this;
 };
@@ -722,12 +727,13 @@ Socket.prototype._destroy = function(exception, cb) {
     this[kBytesWritten] = this._handle.bytesWritten;
 
     if (this.resetAndClosing) {
+      this.resetAndClosing = false;
       const err = this._handle.reset(() => {
         debug('emit close');
         this.emit('close', isException);
       });
       if (err)
-        throw errnoException(err, 'reset');
+        this.emit('error', errnoException(err, 'reset'));
     } else {
       this._handle.close(() => {
         debug('emit close');
@@ -752,6 +758,12 @@ Socket.prototype._destroy = function(exception, cb) {
   }
 };
 
+Socket.prototype._reset = function() {
+  debug('reset connection');
+  this.resetAndClosing = true;
+  return this.destroy();
+};
+
 Socket.prototype._getpeername = function() {
   if (!this._handle || !this._handle.getpeername) {
     return this._peername || {};

test/parallel/test-net-connect-reset-after-destroy.js

@@ -0,0 +1,29 @@
+'use strict';
+const common = require('../common');
+const net = require('net');
+const assert = require('assert');
+
+const server = net.createServer();
+server.listen(0, common.mustCall(function() {
+  const port = server.address().port;
+  const conn = net.createConnection(port);
+  server.on('connection', (socket) => {
+    socket.on('error', common.expectsError({
+      code: 'ECONNRESET',
+      message: 'read ECONNRESET',
+      name: 'Error'
+    }));
+  });
+
+  conn.on('connect', common.mustCall(function() {
+    assert.strictEqual(conn, conn.resetAndDestroy().destroy());
+    conn.on('error', common.mustNotCall());
+
+    conn.write(Buffer.from('fzfzfzfzfz'), common.expectsError({
+      code: 'ERR_STREAM_DESTROYED',
+      message: 'Cannot call write after a stream was destroyed',
+      name: 'Error'
+    }));
+    server.close();
+  }));
+}));

test/parallel/test-net-connect-reset-before-connected.js

@@ -0,0 +1,13 @@
+'use strict';
+const common = require('../common');
+const net = require('net');
+
+const server = net.createServer();
+server.listen(0);
+const port = server.address().port;
+const socket = net.connect(port, common.localhostIPv4, common.mustNotCall());
+socket.on('error', common.mustNotCall());
+server.close();
+socket.resetAndDestroy();
+// `reset` waiting socket connected to sent the RST packet
+socket.destroy();

test/parallel/test-net-connect-reset-until-connected.js

@@ -0,0 +1,20 @@
+'use strict';
+
+const common = require('../common');
+const net = require('net');
+
+const server = net.createServer();
+server.listen(0, common.mustCall(function() {
+  const port = server.address().port;
+  const conn = net.createConnection(port);
+  conn.on('close', common.mustCall());
+  server.on('connection', (socket) => {
+    socket.on('error', common.expectsError({
+      code: 'ECONNRESET',
+      message: 'read ECONNRESET',
+      name: 'Error'
+    }));
+    server.close();
+  });
+  conn.resetAndDestroy();
+}));

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

@@ -0,0 +1,13 @@
+'use strict';
+const common = require('../common');
+const net = require('net');
+
+const socket = new net.Socket();
+socket.resetAndDestroy();
+// Emit error if socket is not connecting/connected
+socket.on('error', common.mustCall(
+  common.expectsError({
+    code: 'ERR_SOCKET_CLOSED',
+    name: 'Error'
+  }))
+);

test/parallel/test-net-server-reset.js

@@ -0,0 +1,36 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+
+const sockets = [];
+
+const server = net.createServer(function(c) {
+  c.on('close', common.mustCall());
+
+  sockets.push(c);
+
+  if (sockets.length === 2) {
+    assert.strictEqual(server.close(), server);
+    sockets.forEach((c) => c.resetAndDestroy());
+  }
+});
+
+server.on('close', common.mustCall());
+
+assert.strictEqual(server, server.listen(0, () => {
+  net.createConnection(server.address().port)
+    .on('error', common.mustCall(
+      common.expectsError({
+        code: 'ECONNRESET',
+        name: 'Error'
+      }))
+    );
+  net.createConnection(server.address().port)
+    .on('error', common.mustCall(
+      common.expectsError({
+        code: 'ECONNRESET',
+        name: 'Error'
+      }))
+    );
+}));

test/parallel/test-net-socket-reset-send.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const common = require('../common');
+const net = require('net');
+const assert = require('assert');
+
+const server = net.createServer();
+server.listen(0, common.mustCall(() => {
+  const port = server.address().port;
+  const conn = net.createConnection(port);
+  server.on('connection', (socket) => {
+    socket.on('error', common.expectsError({
+      code: 'ECONNRESET',
+      message: 'read ECONNRESET',
+      name: 'Error'
+    }));
+  });
+
+  conn.on('connect', common.mustCall(() => {
+    assert.strictEqual(conn, conn.resetAndDestroy().destroy());
+    conn.on('error', common.mustNotCall());
+
+    conn.write(Buffer.from('fzfzfzfzfz'), common.expectsError({
+      code: 'ERR_STREAM_DESTROYED',
+      message: 'Cannot call write after a stream was destroyed',
+      name: 'Error'
+    }));
+    server.close();
+  }));
+}));

test/parallel/test-net-socket-reset-twice.js

@@ -0,0 +1,15 @@
+'use strict';
+const common = require('../common');
+const net = require('net');
+
+const server = net.createServer();
+server.listen(0);
+const port = server.address().port;
+const conn = net.createConnection(port);
+
+conn.on('error', common.mustCall(() => {
+  conn.resetAndDestroy();
+}));
+
+conn.on('close', common.mustCall());
+server.close();