fix(ext/net): enable EDNS0 for Deno.resolveDns

ext/net/ops.rs

@@ -646,7 +646,7 @@ where
     cancel_rid,
   } = args;
 
-  let (config, opts) = if let Some(name_server) =
+  let (config, mut opts) = if let Some(name_server) =
     options.as_ref().and_then(|o| o.name_server.as_ref())
   {
     let group = NameServerConfigGroup::from_ips_clear(
@@ -662,6 +662,8 @@ where
     system_conf::read_system_conf()?
   };
 
+  opts.edns0 = true;
+
   {
     let mut s = state.borrow_mut();
     let perm = s.borrow_mut::<NP>();

tests/registry/npm/dns2/registry.json

@@ -0,0 +1,72 @@
+{
+  "name": "dns2",
+  "description": "A DNS Server and Client Implementation in Pure JavaScript with no dependencies.",
+  "dist-tags": {
+    "latest": "2.1.0"
+  },
+  "versions": {
+    "2.1.0": {
+      "name": "dns2",
+      "version": "2.1.0",
+      "description": "A DNS Server and Client Implementation in Pure JavaScript with no dependencies.",
+      "main": "index.js",
+      "scripts": {
+        "test": "node test",
+        "lint": "eslint .",
+        "example-server-udp": "node example/server/udp.js",
+        "example-server-tcp": "node example/server/tcp.js",
+        "example-server-doh": "node example/server/doh.js",
+        "example-client-doh": "node example/client/doh.js",
+        "example-client-udp": "node example/client/udp.js",
+        "example-client-tcp": "node example/client/tcp.js",
+        "example-client-google": "node example/client/google.js",
+        "example-client-udp-subnet": "node example/client/udp-subnet.js"
+      },
+      "author": {
+        "name": "Liu Song",
+        "email": "[email protected]"
+      },
+      "license": "MIT",
+      "repository": {
+        "type": "git",
+        "url": "git+https://github.com/song940/node-dns.git"
+      },
+      "bugs": {
+        "url": "https://github.com/song940/node-dns/issues"
+      },
+      "devDependencies": {
+        "eslint": "^7.28.0",
+        "eslint-config-semistandard": "^15.0.1",
+        "eslint-plugin-node": "^11.1.0",
+        "eslint-plugin-promise": "^4.2.1"
+      },
+      "gitHead": "28fd77405b98081ac1efb41d0c800e827c1cf6ff",
+      "_id": "[email protected]",
+      "_nodeVersion": "19.3.0",
+      "_npmVersion": "9.2.0",
+      "dist": {
+        "integrity": "sha512-m27K11aQalRbmUs7RLaz6aPyceLjAoqjPRNTdE7qUouQpl+PC8Bi67O+i9SuJUPbQC8dxFrczAxfmTPuTKHNkw==",
+        "shasum": "15b07567befb2b914aedbb55a9ea0862c63c3d73",
+        "tarball": "http://localhost:4260/dns2/dns2-2.1.0.tgz",
+        "fileCount": 37,
+        "unpackedSize": 75538
+      },
+      "directories": {},
+      "_hasShrinkwrap": false
+    }
+  },
+  "homepage": "https://github.com/song940/node-dns#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/song940/node-dns.git"
+  },
+  "author": {
+    "name": "Liu Song",
+    "email": "[email protected]"
+  },
+  "bugs": {
+    "url": "https://github.com/song940/node-dns/issues"
+  },
+  "license": "MIT",
+  "readmeFilename": "README.md"
+}

tests/specs/run/resolve_dns_edns0/__test__.jsonc

@@ -0,0 +1,9 @@
+{
+  "tests": {
+    "resolve_dns": {
+      "args": "test --allow-net=127.0.0.1 test.ts",
+      "output": "test.out",
+      "exitCode": 0
+    }
+  }
+}

tests/specs/run/resolve_dns_edns0/test.out

@@ -0,0 +1,6 @@
+[WILDCARD]
+running 1 test from ./test.ts
+EDNS0 enabled ... ok ([WILDCARD]s)
+
+ok | 1 passed | 0 failed ([WILDCARD]s)
+

tests/specs/run/resolve_dns_edns0/test.ts

@@ -0,0 +1,36 @@
+// Copyright 2018-2025 the Deno authors. MIT license.
+import dns2 from "npm:[email protected]";
+
+Deno.test("EDNS0 enabled", async () => {
+  // With EDNS0 enabled, Deno.resolveDns can handle 44 A records.
+  const NUM_RECORD = 44;
+  const { Packet } = dns2;
+  const server = dns2.createServer({
+    udp: true,
+    // deno-lint-ignore no-explicit-any
+    handle(request: any, send: any) {
+      const response = Packet.createResponseFromRequest(request);
+      const { name } = request.questions[0];
+      for (const i of [...Array(NUM_RECORD).keys()]) {
+        response.answers.push({
+          name,
+          type: Packet.TYPE.A,
+          class: Packet.CLASS.IN,
+          ttl: 300,
+          address: "1.2.3." + i,
+        });
+      }
+      send(response);
+    },
+  });
+  const { udp: { port } } = await server.listen({
+    udp: { port: 0, address: "127.0.0.1", type: "udp4" },
+  });
+  const addr = await Deno.resolveDns("example.com", "A", {
+    nameServer: { ipAddr: "127.0.0.1", port },
+  });
+  if (addr.length !== NUM_RECORD) {
+    throw new Error(`Expected ${NUM_RECORD} records, got ${addr.length}`);
+  }
+  await server.close();
+});