quic: refactor and improve ipv6Only

Ignore `ipv6Only: true` when binding to `'udp4'` (this differs from
dgram which will still attempt to apply the flag and will fail during
bind). Improve the test so that it should work consistently.

Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: #33935
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

doc/api/quic.md

@@ -261,8 +261,11 @@ added: REPLACEME
       to an IP address.
     * `port` {number} The local port to bind to.
     * `type` {string} Either `'udp4'` or `'upd6'` to use either IPv4 or IPv6,
-      respectively.
-    * `ipv6Only` {boolean}
+      respectively. **Default**: `'udp4'`.
+    * `ipv6Only` {boolean} If `type` is `'udp6'`, then setting `ipv6Only` to
+      `true` will disable dual-stack support on the UDP binding -- that is,
+      binding to address `'::'` will not make `'0.0.0.0'` be bound. The option
+      is ignored if `type` is `'udp4'`. **Default**: `false`.
   * `lookup` {Function} A custom DNS lookup function. Default `dns.lookup()`.
   * `maxConnections` {number} The maximum number of total active inbound
     connections.
@@ -1387,8 +1390,11 @@ added: REPLACEME
     to an IP address.
   * `port` {number} The local port to bind to.
   * `type` {string} Either `'udp4'` or `'upd6'` to use either IPv4 or IPv6,
-    respectively.
-  * `ipv6Only` {boolean}
+    respectively. **Default**: `'udp4'`.
+  * `ipv6Only` {boolean} If `type` is `'udp6'`, then setting `ipv6Only` to
+    `true` will disable dual-stack support on the UDP binding -- that is,
+    binding to address `'::'` will not make `'0.0.0.0'` be bound. The option
+    is ignored if `type` is `'udp4'`. **Default**: `false`.
 * Returns: {QuicEndpoint}
 
 Creates and adds a new `QuicEndpoint` to the `QuicSocket` instance.
@@ -1519,7 +1525,10 @@ added: REPLACEME
     `SSL_OP_CIPHER_SERVER_PREFERENCE` to be set in `secureOptions`, see
     [OpenSSL Options][] for more information.
   * `idleTimeout` {number}
-  * `ipv6Only` {boolean}
+  * `ipv6Only` {boolean} If `type` is `'udp6'`, then setting `ipv6Only` to
+    `true` will disable dual-stack support on the UDP binding -- that is,
+    binding to address `'::'` will not make `'0.0.0.0'` be bound. The option
+    is ignored if `type` is `'udp4'`. **Default**: `false`.
   * `key` {string|string[]|Buffer|Buffer[]|Object[]} Private keys in PEM format.
     PEM allows the option of private keys being encrypted. Encrypted keys will
     be decrypted with `options.passphrase`. Multiple keys using different
@@ -1578,7 +1587,7 @@ added: REPLACEME
     `QuicClientSession` object.
   * `type`: {string} Identifies the type of UDP socket. The value must either
     be `'udp4'`, indicating UDP over IPv4, or `'udp6'`, indicating UDP over
-    IPv6. Defaults to `'udp4'`.
+    IPv6. **Default**: `'udp4'`.
 
 Create a new `QuicClientSession`. This function can be called multiple times
 to create sessions associated with different endpoints on the same

lib/internal/quic/core.js

@@ -667,6 +667,7 @@ class QuicEndpoint {
     this.#lookup = lookup || (type === AF_INET6 ? lookup6 : lookup4);
     this.#port = port;
     this.#reuseAddr = !!reuseAddr;
+    this.#type = type;
     this.#udpSocket = dgram.createSocket(type === AF_INET6 ? 'udp6' : 'udp4');
 
     // kUDPHandleForTesting is only used in the Node.js test suite to
@@ -688,7 +689,7 @@ class QuicEndpoint {
     const obj = {
       address: this.address,
       fd: this.#fd,
-      type: this.#type
+      type: this.#type === AF_INET6 ? 'udp6' : 'udp4'
     };
     return `QuicEndpoint ${util.format(obj)}`;
   }
@@ -726,9 +727,10 @@ class QuicEndpoint {
       // what conditions does this happen?
       return;
     }
+
     const flags =
       (this.#reuseAddr ? UV_UDP_REUSEADDR : 0) |
-      (this.#ipv6Only ? UV_UDP_IPV6ONLY : 0);
+      (this.#type === AF_INET6 && this.#ipv6Only ? UV_UDP_IPV6ONLY : 0);
 
     const ret = udpHandle.bind(ip, this.#port, flags);
     if (ret) {

test/parallel/test-quic-ipv6only.js

@@ -16,26 +16,24 @@ const { once } = require('events');
 
 const kALPN = 'zzz';
 
-// Setting `type` to `udp4` while setting `ipv6Only` to `true` is possible
-// and it will throw an error.
-{
+// Setting `type` to `udp4` while setting `ipv6Only` to `true` is possible.
+// The ipv6Only setting will be ignored.
+async function ipv4() {
   const server = createQuicSocket({
     endpoint: {
       type: 'udp4',
       ipv6Only: true
-    } });
-
-  server.on('error', common.mustCall((err) => {
-    assert.strictEqual(err.code, 'EINVAL');
-    assert.strictEqual(err.message, 'bind EINVAL 0.0.0.0');
-  }));
-
+    }
+  });
+  server.on('error', common.mustNotCall());
   server.listen({ key, cert, ca, alpn: kALPN });
+  await once(server, 'ready');
+  server.close();
 }
 
-// Connecting ipv6 server by "127.0.0.1" should work when `ipv6Only`
-// is set to `false`.
-(async () => {
+// Connecting to ipv6 server using "127.0.0.1" should work when
+// `ipv6Only` is set to `false`.
+async function ipv6() {
   const server = createQuicSocket({
     endpoint: {
       type: 'udp6',
@@ -54,6 +52,7 @@ const kALPN = 'zzz';
   const session = client.connect({
     address: common.localhostIPv4,
     port: server.endpoints[0].address.port,
+    ipv6Only: true,
   });
 
   await once(session, 'secure');
@@ -70,11 +69,11 @@ const kALPN = 'zzz';
     once(client, 'close'),
     once(server, 'close')
   ]);
-})().then(common.mustCall());
+}
 
 // When the `ipv6Only` set to `true`, a client cann't connect to it
 // through "127.0.0.1".
-(async () => {
+async function ipv6Only() {
   const server = createQuicSocket({
     endpoint: {
       type: 'udp6',
@@ -87,10 +86,13 @@ const kALPN = 'zzz';
 
   await once(server, 'ready');
 
+  // This will attempt to connect to the ipv4 localhost address
+  // but should fail as the connection idle timeout expires.
   const session = client.connect({
     address: common.localhostIPv4,
     port: server.endpoints[0].address.port,
     idleTimeout: common.platformTimeout(1),
+    ipv6Only: true,
   });
 
   session.on('secure', common.mustNotCall());
@@ -104,11 +106,11 @@ const kALPN = 'zzz';
     once(client, 'close'),
     once(server, 'close')
   ]);
-})();
+}
 
 // Creating the QuicSession fails when connect type does not match the
 // the connect IP address...
-(async () => {
+async function mismatch() {
   const server = createQuicSocket({ endpoint: { type: 'udp6' } });
   const client = createQuicSocket({ client: { key, cert, ca, alpn: kALPN } });
 
@@ -137,4 +139,10 @@ const kALPN = 'zzz';
     once(client, 'close'),
     once(server, 'close')
   ]);
-})().then(common.mustCall());
+}
+
+ipv4()
+  .then(ipv6)
+  .then(ipv6Only)
+  .then(mismatch)
+  .then(common.mustCall());