client: use "localhost:port" as authority if target is ":port"

clientconn.go

@@ -259,6 +259,8 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 		cc.authority = cc.dopts.authority
 	} else if strings.HasPrefix(cc.target, "unix:") {
 		cc.authority = "localhost"
+	} else if strings.HasPrefix(cc.parsedTarget.Endpoint, ":") {
+		cc.authority = "localhost" + cc.parsedTarget.Endpoint
 	} else {
 		// Use endpoint from "scheme://authority/endpoint" as the default
 		// authority for ClientConn.

test/authority_test.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -33,44 +34,48 @@ import (
 	testpb "google.golang.org/grpc/test/grpc_testing"
 )
 
+func authorityChecker(expectedAuthority *string) func(context.Context, *testpb.Empty) (*testpb.Empty, error) {
+	return func(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
+		md, ok := metadata.FromIncomingContext(ctx)
+		if !ok {
+			return nil, status.Error(codes.InvalidArgument, "failed to parse metadata")
+		}
+		auths, ok := md[":authority"]
+		if !ok {
+			return nil, status.Error(codes.InvalidArgument, "no authority header")
+		}
+		if len(auths) != 1 {
+			return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("no authority header, auths = %v", auths))
+		}
+		if auths[0] != *expectedAuthority {
+			return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("invalid authority header %v, expected %v", auths[0], *expectedAuthority))
+		}
+		return &testpb.Empty{}, nil
+	}
+}
+
 func runUnixTest(t *testing.T, address, target, expectedAuthority string, dialer func(context.Context, string) (net.Conn, error)) {
 	if err := os.RemoveAll(address); err != nil {
 		t.Fatalf("Error removing socket file %v: %v\n", address, err)
 	}
-	us := &stubServer{
-		emptyCall: func(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
-			md, ok := metadata.FromIncomingContext(ctx)
-			if !ok {
-				return nil, status.Error(codes.InvalidArgument, "failed to parse metadata")
-			}
-			auths, ok := md[":authority"]
-			if !ok {
-				return nil, status.Error(codes.InvalidArgument, "no authority header")
-			}
-			if len(auths) < 1 {
-				return nil, status.Error(codes.InvalidArgument, "no authority header")
-			}
-			if auths[0] != expectedAuthority {
-				return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("invalid authority header %v, expected %v", auths[0], expectedAuthority))
-			}
-			return &testpb.Empty{}, nil
-		},
-		network: "unix",
-		address: address,
-		target:  target,
+	ss := &stubServer{
+		emptyCall: authorityChecker(&expectedAuthority),
+		network:   "unix",
+		address:   address,
+		target:    target,
 	}
 	opts := []grpc.DialOption{}
 	if dialer != nil {
 		opts = append(opts, grpc.WithContextDialer(dialer))
 	}
-	if err := us.Start(nil, opts...); err != nil {
+	if err := ss.Start(nil, opts...); err != nil {
 		t.Fatalf("Error starting endpoint server: %v", err)
 		return
 	}
-	defer us.Stop()
-	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer ss.Stop()
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
-	_, err := us.client.EmptyCall(ctx, &testpb.Empty{})
+	_, err := ss.client.EmptyCall(ctx, &testpb.Empty{})
 	if err != nil {
 		t.Errorf("us.client.EmptyCall(_, _) = _, %v; want _, nil", err)
 	}
@@ -147,3 +152,36 @@ func (s) TestUnixCustomDialer(t *testing.T) {
 		})
 	}
 }
+
+func (s) TestColonPortAuthority(t *testing.T) {
+	expectedAuthority := ""
+	ss := &stubServer{
+		emptyCall: authorityChecker(&expectedAuthority),
+		network:   "tcp",
+	}
+	if err := ss.Start(nil); err != nil {
+		t.Fatalf("Error starting endpoint server: %v", err)
+		return
+	}
+	defer ss.Stop()
+	s := strings.Split(ss.address, ":")
+	if len(s) != 2 {
+		t.Fatalf("No port in address: %v", ss.address)
+		return
+	}
+	expectedAuthority = "localhost:" + s[1]
+	// ss.Start dials, but not the ":[port]" target that is being tested here.
+	// Dial again, with ":[port]" as the target.
+	cc, err := grpc.Dial(":"+s[1], grpc.WithInsecure())
+	if err != nil {
+		t.Fatalf("grpc.Dial(%q) = %v", ss.target, err)
+		return
+	}
+	defer cc.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	_, err = testpb.NewTestServiceClient(cc).EmptyCall(ctx, &testpb.Empty{})
+	if err != nil {
+		t.Errorf("us.client.EmptyCall(_, _) = _, %v; want _, nil", err)
+	}
+}