GODRIVER-2620 Fix hostname parsing for SRV polling. (#1112)

* GODRIVER-2620 Fix hostname parsing for SRV polling.

Co-authored-by: Preston Vasquez <24281431+prestonvasquez@users.noreply.github.com>
Co-authored-by: Kevin Albertson <kevin.albertson@10gen.com>

x/mongo/driver/topology/polling_srv_records_test.go

@@ -128,9 +128,22 @@ func TestPollingSRVRecordsSpec(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping integration test in short mode")
 	}
+	for _, uri := range []string{
+		"mongodb+srv://test1.test.build.10gen.cc/?heartbeatFrequencyMS=100",
+		// Test with user:pass as a regression test for GODRIVER-2620
+		"mongodb+srv://user:pass@test1.test.build.10gen.cc/?heartbeatFrequencyMS=100",
+	} {
+		t.Run(uri, func(t *testing.T) {
+			testPollingSRVRecordsSpec(t, uri)
+		})
+	}
+}
+
+func testPollingSRVRecordsSpec(t *testing.T, uri string) {
+	t.Helper()
 	for _, tt := range srvPollingTests {
 		t.Run(tt.name, func(t *testing.T) {
-			cs, err := connstring.ParseAndValidate("mongodb+srv://test1.test.build.10gen.cc/?heartbeatFrequencyMS=100")
+			cs, err := connstring.ParseAndValidate(uri)
 			require.NoError(t, err, "Problem parsing the uri: %v", err)
 			topo, err := New(
 				WithConnString(func(connstring.ConnString) connstring.ConnString { return cs }),

x/mongo/driver/topology/topology.go

@@ -14,6 +14,8 @@ import (
 	"context"
 	"errors"
 	"math/rand"
+	"net"
+	"net/url"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -224,7 +226,21 @@ func (t *Topology) Connect() error {
 
 	t.serversLock.Unlock()
 	if t.pollingRequired {
-		go t.pollSRVRecords()
+		uri, err := url.Parse(t.cfg.uri)
+		if err != nil {
+			return err
+		}
+		// sanity check before passing the hostname to resolver
+		if parsedHosts := strings.Split(uri.Host, ","); len(parsedHosts) != 1 {
+			return fmt.Errorf("URI with SRV must include one and only one hostname")
+		}
+		_, _, err = net.SplitHostPort(uri.Host)
+		if err == nil {
+			// we were able to successfully extract a port from the host,
+			// but should not be able to when using SRV
+			return fmt.Errorf("URI with srv must not include a port number")
+		}
+		go t.pollSRVRecords(uri.Host)
 		t.pollingwg.Add(1)
 	}
 
@@ -495,7 +511,7 @@ func (t *Topology) selectServerFromDescription(desc description.Topology,
 	return suitable, nil
 }
 
-func (t *Topology) pollSRVRecords() {
+func (t *Topology) pollSRVRecords(hosts string) {
 	defer t.pollingwg.Done()
 
 	serverConfig, _ := newServerConfig(t.cfg.serverOpts...)
@@ -512,13 +528,6 @@ func (t *Topology) pollSRVRecords() {
 		}
 	}()
 
-	// remove the scheme
-	uri := t.cfg.uri[14:]
-	hosts := uri
-	if idx := strings.IndexAny(uri, "/?@"); idx != -1 {
-		hosts = uri[:idx]
-	}
-
 	for {
 		select {
 		case <-pollTicker.C: