net: do not attempt new connections when aborted

Author: ShogunPanda

lib/net.js

@@ -1663,8 +1663,11 @@ function afterConnectMultiple(context, current, status, handle, req, readable, w
   if (status !== 0) {
     ArrayPrototypePush(context.errors, createConnectionError(req, status));
 
-    // Try the next address
-    internalConnectMultiple(context, status === UV_ECANCELED);
+    // Try the next address, unless we were aborted
+    if (context.socket.connecting) {
+      internalConnectMultiple(context, status === UV_ECANCELED);
+    }
+
     return;
   }
 
@@ -1684,7 +1687,11 @@ function internalConnectMultipleTimeout(context, req, handle) {
   req.oncomplete = undefined;
   ArrayPrototypePush(context.errors, createConnectionError(req, UV_ETIMEDOUT));
   handle.close();
-  internalConnectMultiple(context);
+
+  // Try the next address, unless we were aborted
+  if (context.socket.connecting) {
+    internalConnectMultiple(context);
+  }
 }
 
 function addServerAbortSignalOption(self, options) {

test/parallel/test-net-autoselectfamily-timeout-cancelling.js

@@ -0,0 +1,100 @@
+'use strict';
+
+const common = require('../common');
+const { addresses: { INET4_IP } } = require('../common/internet');
+const { parseDNSPacket, writeDNSPacket } = require('../common/dns');
+
+const assert = require('assert');
+const dgram = require('dgram');
+const { Resolver } = require('dns');
+const { createConnection } = require('net');
+
+// Test that happy eyeballs algorithm properly handles cancellations.
+
+// Purposely set this to a low value because we want all connection but the last to fail
+const autoSelectFamilyAttemptTimeout = 15;
+
+function _lookup(resolver, hostname, options, cb) {
+  resolver.resolve(hostname, 'ANY', (err, replies) => {
+    assert.notStrictEqual(options.family, 4);
+
+    if (err) {
+      return cb(err);
+    }
+
+    const hosts = replies
+      .map((r) => ({ address: r.address, family: r.type === 'AAAA' ? 6 : 4 }))
+      .sort((a, b) => b.family - a.family);
+
+    if (options.all === true) {
+      return cb(null, hosts);
+    }
+
+    return cb(null, hosts[0].address, hosts[0].family);
+  });
+}
+
+function createDnsServer(ipv6Addrs, ipv4Addrs, cb) {
+  if (!Array.isArray(ipv6Addrs)) {
+    ipv6Addrs = [ipv6Addrs];
+  }
+
+  if (!Array.isArray(ipv4Addrs)) {
+    ipv4Addrs = [ipv4Addrs];
+  }
+
+  // Create a DNS server which replies with a AAAA and a A record for the same host
+  const socket = dgram.createSocket('udp4');
+
+  socket.on('message', common.mustCall((msg, { address, port }) => {
+    const parsed = parseDNSPacket(msg);
+    const domain = parsed.questions[0].domain;
+    assert.strictEqual(domain, 'example.org');
+
+    socket.send(writeDNSPacket({
+      id: parsed.id,
+      questions: parsed.questions,
+      answers: [
+        ...ipv6Addrs.map((address) => ({ type: 'AAAA', address, ttl: 123, domain: 'example.org' })),
+        ...ipv4Addrs.map((address) => ({ type: 'A', address, ttl: 123, domain: 'example.org' })),
+      ]
+    }), port, address);
+  }));
+
+  socket.bind(0, () => {
+    const resolver = new Resolver();
+    resolver.setServers([`127.0.0.1:${socket.address().port}`]);
+
+    cb({ dnsServer: socket, lookup: _lookup.bind(null, resolver) });
+  });
+}
+
+// Test that if a connection attempt is aborted before finishing the connection, then the process does not crash
+{
+  createDnsServer([], [INET4_IP, '127.0.0.1', INET4_IP], common.mustCall(function({ dnsServer, lookup }) {
+    const connection = createConnection({
+      host: 'example.org',
+      port: 443,
+      lookup,
+      autoSelectFamily: true,
+      autoSelectFamilyAttemptTimeout,
+    });
+
+    let destroyTimeoutSet = false;
+    connection.on('lookup', common.mustCall(() => {
+      if (destroyTimeoutSet) {
+        return;
+      }
+
+      destroyTimeoutSet = true;
+      setTimeout(() => {
+        connection.destroy();
+      }, autoSelectFamilyAttemptTimeout);
+    }, 3));
+
+    connection.on('ready', common.mustNotCall());
+    connection.on('close', common.mustCall(() => {
+      dnsServer.close();
+    }));
+  }));
+}