feat(NODE-6289): allow valid srv hostnames with less than 3 parts

src/utils.ts

@@ -1165,16 +1165,13 @@ export function checkParentDomainMatch(address: string, srvHost: string): void {
   // Add leading dot back to string so
   //   an srvHostDomain = '.trusted.site'
   //   will not satisfy an addressDomain that endsWith '.fake-trusted.site'
-  const addressDomain = srvIsLessThanThreeParts
-    ? normalizedAddress
-    : `.${normalizedAddress.replace(allCharacterBeforeFirstDot, '')}`;
-  const srvHostDomain = srvIsLessThanThreeParts
+  const addressDomain = `.${normalizedAddress.replace(allCharacterBeforeFirstDot, '')}`;
+  let srvHostDomain = srvIsLessThanThreeParts
     ? normalizedSrvHost
     : `.${normalizedSrvHost.replace(allCharacterBeforeFirstDot, '')}`;
 
-  if (!addressDomain.endsWith(srvHostDomain)) {
-    // TODO(NODE-3484): Replace with MongoConnectionStringError
-    throw new MongoAPIError('Server record does not share hostname with parent URI');
+  if (!srvHostDomain.startsWith('.')) {
+    srvHostDomain = '.' + srvHostDomain;
   }
   if (
     srvIsLessThanThreeParts &&
@@ -1183,6 +1180,10 @@ export function checkParentDomainMatch(address: string, srvHost: string): void {
     // TODO(NODE-3484): Replace with MongoConnectionStringError
     throw new MongoAPIError('Server record does not have least one more domain than parent URI');
   }
+  if (!addressDomain.endsWith(srvHostDomain)) {
+    // TODO(NODE-3484): Replace with MongoConnectionStringError
+    throw new MongoAPIError('Server record does not share hostname with parent URI');
+  }
 }
 
 interface RequestOptions {

test/integration/initial-dns-seedlist-discovery/initial_dns_seedlist_discovery.prose.test.ts

@@ -6,14 +6,16 @@ import { MongoAPIError, Server, ServerDescription, Topology } from '../../mongod
 import { topologyWithPlaceholderClient } from '../../tools/utils';
 
 describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
-  context('1) When running validation on an SRV string before DNS resolution', function () {
+  context('1. When running validation on an SRV string before DNS resolution', function () {
+    let client;
+
     beforeEach(async function () {
       // this fn stubs DNS resolution to always pass - so we are only checking pre-DNS validation
 
       sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
         return [
           {
-            name: 'resolved.mongodb.localhost',
+            name: 'resolved.mongo.localhost',
             port: 27017,
             weight: 0,
             priority: 0
@@ -36,23 +38,22 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
 
     afterEach(async function () {
       sinon.restore();
+      client.close();
     });
 
     it('does not error on an SRV because it has one domain level', async function () {
-      const client = await this.configuration.newClient('mongodb+srv://localhost', {});
-      client.connect();
-      client.close();
+      client = await this.configuration.newClient('mongodb+srv://localhost', {});
+      await client.connect();
     });
 
     it('does not error on an SRV because it has two domain levels', async function () {
-      const client = await this.configuration.newClient('mongodb+srv://mongodb.localhost', {});
-      client.connect();
-      client.close();
+      client = await this.configuration.newClient('mongodb+srv://mongo.localhost', {});
+      await client.connect();
     });
   });
 
   context(
-    '2) When given a host from DNS resolution that does NOT end with the original SRVs domain name',
+    '2. When given a host from DNS resolution that does NOT end with the original SRVs domain name',
     function () {
       beforeEach(async function () {
         sinon.stub(dns.promises, 'resolveTxt').callsFake(async () => {
@@ -68,7 +69,7 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
         sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
           return [
             {
-              name: 'localhost.mongodb', // this string contains the SRV but does not end with it
+              name: 'localhost.mongodb',
               port: 27017,
               weight: 0,
               priority: 0
@@ -87,15 +88,15 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
         sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
           return [
             {
-              name: 'evil.localhost', // this string only ends with part of the domain, not all of it!
+              name: 'test_1.evil.local', // this string only ends with part of the domain, not all of it!
               port: 27017,
               weight: 0,
               priority: 0
             }
           ];
         });
         const err = await this.configuration
-          .newClient('mongodb+srv://mongodb.localhost', {})
+          .newClient('mongodb+srv://mongo.local', {})
           .connect()
           .catch(e => e);
         expect(err).to.be.instanceOf(MongoAPIError);
@@ -106,7 +107,7 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
         sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
           return [
             {
-              name: 'blogs.evil.co.uk',
+              name: 'blogs.evil.com',
               port: 27017,
               weight: 0,
               priority: 0
@@ -124,7 +125,7 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
   );
 
   context(
-    '3) When given a host from DNS resolution that is identical to the original SRVs hostname',
+    '3. When given a host from DNS resolution that is identical to the original SRVs hostname',
     function () {
       beforeEach(async function () {
         sinon.stub(dns.promises, 'resolveTxt').callsFake(async () => {
@@ -161,15 +162,15 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
         sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
           return [
             {
-              name: 'mongodb.localhost',
+              name: 'mongo.local',
               port: 27017,
               weight: 0,
               priority: 0
             }
           ];
         });
         const err = await this.configuration
-          .newClient('mongodb+srv://mongodb.localhost', {})
+          .newClient('mongodb+srv://mongo.local', {})
           .connect()
           .catch(e => e);
         expect(err).to.be.instanceOf(MongoAPIError);
@@ -179,4 +180,76 @@ describe('Initial DNS Seedlist Discovery (Prose Tests)', () => {
       });
     }
   );
+
+  context(
+    '4. When given a returned address that does NOT share the domain name of the SRV record because its missing a `.`',
+    function () {
+      beforeEach(async function () {
+        sinon.stub(dns.promises, 'resolveTxt').callsFake(async () => {
+          throw { code: 'ENODATA' };
+        });
+      });
+
+      afterEach(async function () {
+        sinon.restore();
+      });
+
+      it('an SRV with one domain level causes a runtime error', async function () {
+        sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
+          return [
+            {
+              name: 'test_1.cluster_1localhost',
+              port: 27017,
+              weight: 0,
+              priority: 0
+            }
+          ];
+        });
+        const err = await this.configuration
+          .newClient('mongodb+srv://localhost', {})
+          .connect()
+          .catch(e => e);
+        expect(err).to.be.instanceOf(MongoAPIError);
+        expect(err.message).to.equal('Server record does not share hostname with parent URI');
+      });
+
+      it('an SRV with two domain levels causes a runtime error', async function () {
+        sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
+          return [
+            {
+              name: 'test_1.my_hostmongo.local',
+              port: 27017,
+              weight: 0,
+              priority: 0
+            }
+          ];
+        });
+        const err = await this.configuration
+          .newClient('mongodb+srv://mongo.local', {})
+          .connect()
+          .catch(e => e);
+        expect(err).to.be.instanceOf(MongoAPIError);
+        expect(err.message).to.equal('Server record does not share hostname with parent URI');
+      });
+
+      it('an SRV with three domain levels causes a runtime error', async function () {
+        sinon.stub(dns.promises, 'resolveSrv').callsFake(async () => {
+          return [
+            {
+              name: 'cluster.testmongodb.com',
+              port: 27017,
+              weight: 0,
+              priority: 0
+            }
+          ];
+        });
+        const err = await this.configuration
+          .newClient('mongodb+srv://blogs.mongodb.com', {})
+          .connect()
+          .catch(e => e);
+        expect(err).to.be.instanceOf(MongoAPIError);
+        expect(err.message).to.equal('Server record does not share hostname with parent URI');
+      });
+    }
+  );
 });