net: exclude ipv6 loopback addresses from server.listen

lib/net.js

@@ -35,6 +35,7 @@ const {
   NumberParseInt,
   ObjectDefineProperty,
   ObjectSetPrototypeOf,
+  StringPrototypeStartsWith,
   Symbol,
   SymbolAsyncDispose,
   SymbolDispose,
@@ -2118,19 +2119,38 @@ Server.prototype.listen = function(...args) {
   throw new ERR_INVALID_ARG_VALUE('options', options);
 };
 
+function isIpv6Loopback({ address, family }) {
+  return family === 6 && StringPrototypeStartsWith(address, 'fe80::');
+}
+
+function filterOnlyValidAddress(addresses) {
+  // Return the first non IPV6 loopback address if present
+  for (const address of addresses) {
+    if (!isIpv6Loopback(address)) {
+      return address;
+    }
+  }
+
+  // Otherwise return the first address
+  return addresses[0];
+}
+
 function lookupAndListen(self, port, address, backlog,
                          exclusive, flags) {
   if (dns === undefined) dns = require('dns');
   const listeningId = self._listeningId;
-  dns.lookup(address, function doListen(err, ip, addressType) {
+
+  dns.lookup(address, { all: true }, (err, addresses) => {
     if (listeningId !== self._listeningId) {
       return;
     }
     if (err) {
       self.emit('error', err);
     } else {
-      addressType = ip ? addressType : 4;
-      listenInCluster(self, ip, port, addressType,
+      const validAddress = filterOnlyValidAddress(addresses);
+      const family = validAddress?.family || 4;
+
+      listenInCluster(self, validAddress.address, port, family,
                       backlog, undefined, exclusive, flags);
     }
   });

test/parallel/test-net-server-close-before-calling-lookup-callback.js

@@ -3,5 +3,5 @@
 const common = require('../common');
 const net = require('net');
 // Process should exit because it does not create a real TCP server.
-// Paas localhost to ensure create TCP handle asynchronously because It causes DNS resolution.
+// Pass localhost to ensure create TCP handle asynchronously because It causes DNS resolution.
 net.createServer().listen(0, 'localhost', common.mustNotCall()).close();

test/sequential/test-net-server-listen-ipv6-loopback.js

@@ -0,0 +1,77 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+const dns = require('dns');
+const { mock } = require('node:test');
+
+if (!common.hasIPv6) {
+  common.printSkipMessage('ipv6 part of test, no IPv6 support');
+  return;
+}
+
+// Test on IPv6 Server, dns.lookup throws an error
+{
+  mock.method(dns, 'lookup', (hostname, options, callback) => {
+    callback(new Error('Mocked error'));
+  });
+  const host = 'ipv6_loopback';
+
+  const server = net.createServer();
+
+  server.on('error', common.mustCall((e) => {
+    assert.strictEqual(e.message, 'Mocked error');
+  }));
+
+  server.listen(common.PORT + 2, host);
+}
+
+
+// Test on IPv6 Server, server.listen throws an error
+{
+  mock.method(dns, 'lookup', (hostname, options, callback) => {
+    if (hostname === 'ipv6_loopback') {
+      callback(null, [{ address: 'fe80::1', family: 6 }]);
+    } else {
+      dns.lookup.wrappedMethod(hostname, options, callback);
+    }
+  });
+  const host = 'ipv6_loopback';
+
+  const server = net.createServer();
+
+  server.on('error', common.mustCall((e) => {
+    assert.strictEqual(e.address, 'fe80::1');
+    assert.strictEqual(e.syscall, 'listen');
+  }));
+
+  server.listen(common.PORT + 2, host);
+}
+
+// Test on IPv6 Server, picks 127.0.0.1 between that and fe80::1
+{
+
+  mock.method(dns, 'lookup', (hostname, options, callback) => {
+    if (hostname === 'ipv6_loopback_with_double_entry') {
+      callback(null, [{ address: 'fe80::1', family: 6 },
+                      { address: '127.0.0.1', family: 4 }]);
+    } else {
+      dns.lookup.wrappedMethod(hostname, options, callback);
+    }
+  });
+
+  const host = 'ipv6_loopback_with_double_entry';
+  const family4 = 'IPv4';
+
+  const server = net.createServer();
+
+  server.on('error', common.mustNotCall());
+
+  server.listen(common.PORT + 3, host, common.mustCall(() => {
+    const address = server.address();
+    assert.strictEqual(address.address, '127.0.0.1');
+    assert.strictEqual(address.port, common.PORT + 3);
+    assert.strictEqual(address.family, family4);
+    server.close();
+  }));
+}