feat(server/client): add windows pipe, pipe peer credentials support

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

client/client.go

@@ -3,6 +3,7 @@ package client
 import (
 	"context"
 	"fmt"
+	"net/url"
 	"strings"
 
 	"google.golang.org/grpc"
@@ -19,7 +20,7 @@ type Client interface {
 }
 
 func New(opts ...Option) (Client, error) {
-	c := &client{opts: &options{}}
+	c := &client{opts: &options{dialOptions: []grpc.DialOption{grpc.WithContextDialer(dial)}}}
 	for _, o := range opts {
 		o(c.opts)
 	}
@@ -78,3 +79,32 @@ func (c *client) Invoke(ctx context.Context, method string, args interface{}, re
 func (c *client) NewStream(ctx context.Context, desc *grpc.StreamDesc, method string, opts ...grpc.CallOption) (grpc.ClientStream, error) {
 	return c.cc.NewStream(ctx, desc, method, opts...)
 }
+
+func parseDialTarget(target string) (string, string) {
+	net := "tcp"
+	m1 := strings.Index(target, ":")
+	m2 := strings.Index(target, ":/")
+	// handle unix:addr which will fail with url.Parse
+	if m1 >= 0 && m2 < 0 {
+		if n := target[0:m1]; n == "unix" {
+			return n, target[m1+1:]
+		}
+	}
+	if strings.HasPrefix(target, `\\.\pipe\`) {
+		net = "pipe"
+		return net, target
+	}
+	if m2 >= 0 {
+		t, err := url.Parse(target)
+		if err != nil {
+			return net, target
+		}
+		scheme := t.Scheme
+		addr := t.Host
+		if scheme == "unix" {
+			addr += t.Path
+		}
+		return scheme, addr
+	}
+	return net, target
+}

client/client_test.go

@@ -0,0 +1,26 @@
+package client
+
+import (
+	"testing"
+)
+
+func TestParseDialTarget(t *testing.T) {
+	tests := []struct {
+		input        string
+		expectedNet  string
+		expectedAddr string
+	}{
+		{"tcp://localhost:50051", "tcp", "localhost:50051"},
+		{"localhost:50051", "tcp", "localhost:50051"},
+		{"unix:///tmp/socket", "unix", "/tmp/socket"},
+		{"unix://C:/path/to/socket", "unix", "C:/path/to/socket"},
+		{"unix:path/to/socket", "unix", "path/to/socket"},
+		{`\\.\pipe\example`, "pipe", `\\.\pipe\example`},
+	}
+	for _, test := range tests {
+		net, addr := parseDialTarget(test.input)
+		if net != test.expectedNet || addr != test.expectedAddr {
+			t.Errorf("parseDialTarget(%q) = (%q, %q); want (%q, %q)", test.input, net, addr, test.expectedNet, test.expectedAddr)
+		}
+	}
+}

client/dialer.go

@@ -0,0 +1,12 @@
+//go:build !windows
+package client
+
+import (
+	"context"
+	"net"
+)
+
+func dial(ctx context.Context, addr string) (net.Conn, error) {
+	network, address := parseDialTarget(addr)
+	return (&net.Dialer{}).DialContext(ctx, network, address)
+}

client/dialer_windows.go

@@ -0,0 +1,18 @@
+//go:build windows
+
+package client
+
+import (
+	"context"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+)
+
+func dial(ctx context.Context, addr string) (net.Conn, error) {
+	network, address := parseDialTarget(addr)
+	if network == "pipe" {
+		return winio.DialPipeContext(ctx, address)
+	}
+	return (&net.Dialer{}).DialContext(ctx, network, address)
+}

creds/peercreds/peercreds.go

@@ -2,15 +2,36 @@ package peercreds
 
 import (
 	"context"
+	"crypto/tls"
 	"errors"
 	"net"
 
+	"github.com/soheilhy/cmux"
 	"github.com/tailscale/peercred"
 	"google.golang.org/grpc/credentials"
 )
 
+var ErrUnsupportedConnType = peercred.ErrUnsupportedConnType
+
 var _ credentials.TransportCredentials = (*peerCreds)(nil)
 
+// Creds are the peer credentials.
+type Creds struct {
+	pid int
+	uid string
+}
+
+func (c *Creds) PID() (pid int, ok bool) {
+	return c.pid, c.pid != 0
+}
+
+// UserID returns the userid (or Windows SID) that owns the other side
+// of the connection, if known. (ok is false if not known)
+// The returned string is suitable to passing to os/user.LookupId.
+func (c *Creds) UserID() (uid string, ok bool) {
+	return c.uid, c.uid != ""
+}
+
 var common = credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}
 
 func New() credentials.TransportCredentials {
@@ -27,12 +48,12 @@ type peerCreds struct {
 // AuthInfo we’ll attach to the gRPC peer
 type AuthInfo struct {
 	credentials.CommonAuthInfo
-	Creds *peercred.Creds
+	Creds Creds
 }
 
 func (AuthInfo) AuthType() string { return "peercred" }
 
-func (t *peerCreds) ClientHandshake(_ context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+func (t *peerCreds) ClientHandshake(ctx context.Context, authority string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
 	return t.handshakeConn(conn)
 }
 
@@ -54,15 +75,30 @@ func (t *peerCreds) OverrideServerName(name string) error {
 }
 
 func (t *peerCreds) handshakeConn(conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
-	if conn.RemoteAddr().Network() != "unix" {
-		return nil, nil, errors.New("peercred only works with unix domain sockets")
+	if conn.RemoteAddr().Network() != "unix" && conn.RemoteAddr().Network() != "pipe" {
+		return nil, nil, errors.New("peercred only works with unix domain sockets or Windows named pipes")
 	}
-	creds, err := peercred.Get(conn)
+	inner := conn
+unwrap:
+	for {
+		switch c := inner.(type) {
+		case *cmux.MuxConn:
+			inner = c.Conn
+		case *tls.Conn:
+			inner = c.NetConn()
+		default:
+			break unwrap
+		}
+	}
+	creds, err := Get(inner)
 	if err != nil {
 		if errors.Is(err, peercred.ErrNotImplemented) {
 			return nil, nil, errors.New("peercred not implemented on this OS")
 		}
 		return nil, nil, err
 	}
-	return conn, AuthInfo{Creds: creds, CommonAuthInfo: common}, nil
+	var c Creds
+	c.uid, _ = creds.UserID()
+	c.pid, _ = creds.PID()
+	return conn, AuthInfo{Creds: c, CommonAuthInfo: common}, nil
 }

creds/peercreds/peercreds_unix.go

@@ -0,0 +1,20 @@
+//go:build !windows
+
+package peercreds
+
+import (
+	"net"
+
+	"github.com/tailscale/peercred"
+)
+
+func Get(conn net.Conn) (*Creds, error) {
+	creds, err := peercred.Get(conn)
+	if err != nil {
+		return nil, err
+	}
+	var c Creds
+	c.uid, _ = creds.UserID()
+	c.pid, _ = creds.PID()
+	return &c, nil
+}

creds/peercreds/peercreds_windows.go

@@ -0,0 +1,134 @@
+//go:build windows
+
+package peercreds
+
+import (
+	"fmt"
+	"net"
+	"reflect"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+// Get returns peer creds for the client connected to this server-side pipe
+// connection. The conn must be a net.Conn returned from go-winio's ListenPipe.
+func Get(conn net.Conn) (*Creds, error) {
+	if conn == nil {
+		return nil, ErrUnsupportedConnType
+	}
+
+	h, err := winioPipeHandle(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get client PID for this pipe instance.
+	var pid uint32
+	if err := windows.GetNamedPipeClientProcessId(h, &pid); err != nil {
+		return nil, fmt.Errorf("GetNamedPipeClientProcessId: %w", err)
+	}
+	if pid == 0 {
+		return nil, fmt.Errorf("GetNamedPipeClientProcessId returned pid=0")
+	}
+
+	// Open the client process with query rights.
+	const processQueryLimitedInfo = windows.PROCESS_QUERY_LIMITED_INFORMATION
+	ph, err := windows.OpenProcess(processQueryLimitedInfo, false, pid)
+	if err != nil {
+		return nil, fmt.Errorf("OpenProcess(%d): %w", pid, err)
+	}
+	defer windows.CloseHandle(ph)
+
+	// Open the process token.
+	var token windows.Token
+	if err := windows.OpenProcessToken(ph, windows.TOKEN_QUERY, &token); err != nil {
+		return nil, fmt.Errorf("OpenProcessToken: %w", err)
+	}
+	defer token.Close()
+
+	// Get the token's user SID.
+	tu, err := token.GetTokenUser()
+	if err != nil {
+		return nil, fmt.Errorf("GetTokenUser: %w", err)
+	}
+
+	return &Creds{
+		uid: tu.User.Sid.String(),
+		pid: int(pid),
+	}, nil
+}
+
+// winioPipeHandle digs the underlying syscall HANDLE out of a go-winio
+// pipe connection using reflect + unsafe. This depends on the current
+// internal layout of github.com/Microsoft/go-winio:
+//
+//	type win32Pipe struct {
+//	    *win32File
+//	    path string
+//	}
+//
+//	type win32MessageBytePipe struct {
+//	    win32Pipe
+//	    writeClosed bool
+//	    readEOF     bool
+//	}
+//
+//	type win32File struct {
+//	    handle syscall.Handle
+//	    ...
+//	}
+//
+// See pipe.go + file.go in go-winio. :contentReference[oaicite:1]{index=1}
+func winioPipeHandle(conn net.Conn) (windows.Handle, error) {
+	v := reflect.ValueOf(conn)
+	if !v.IsValid() {
+		return 0, ErrUnsupportedConnType
+	}
+
+	// Peel off interface & pointer layers: net.Conn is an interface and the
+	// concrete type is *win32Pipe or *win32MessageBytePipe.
+	for v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return 0, ErrUnsupportedConnType
+		}
+		v = v.Elem()
+	}
+
+	if v.Kind() != reflect.Struct {
+		return 0, ErrUnsupportedConnType
+	}
+
+	var wfField reflect.Value
+
+	// Case 1: *win32Pipe { *win32File; path string }
+	if f := v.FieldByName("win32File"); f.IsValid() && f.Kind() == reflect.Ptr {
+		wfField = f
+	} else if v.NumField() > 0 {
+		// Case 2: *win32MessageBytePipe { win32Pipe; ... }
+		embedded := v.Field(0)
+		if embedded.IsValid() && embedded.Kind() == reflect.Struct {
+			if f2 := embedded.FieldByName("win32File"); f2.IsValid() && f2.Kind() == reflect.Ptr {
+				wfField = f2
+			}
+		}
+	}
+
+	if !wfField.IsValid() || wfField.IsNil() {
+		return 0, ErrUnsupportedConnType
+	}
+
+	// wfField is a *win32File. Its first field is "handle syscall.Handle".
+	// We only need the first field, so we define a 1-field header type with
+	// compatible layout and reinterpret the pointer.
+	type win32FileHeader struct {
+		Handle windows.Handle // same underlying type as syscall.Handle
+	}
+
+	ptr := unsafe.Pointer(wfField.Pointer())
+	h := (*win32FileHeader)(ptr).Handle
+	if h == 0 {
+		return 0, fmt.Errorf("winio pipe handle is 0")
+	}
+	return h, nil
+}

example/example.go

@@ -7,6 +7,8 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"os"
+	"runtime"
 	"strings"
 	"time"
 
@@ -51,7 +53,12 @@ func run(ctx context.Context, opts ...service.Option) {
 	)
 	defer p.Shutdown(ctx)
 
-	address := "0.0.0.0:9991"
+	// address := "0.0.0.0:9991"
+	address := "unix:///tmp/example.sock"
+	if runtime.GOOS == "windows" {
+		address = `\\.\pipe\example`
+	}
+	defer os.Remove("/tmp/example.sock")
 
 	var svc service.Service
 	opts = append(opts,
@@ -96,7 +103,7 @@ func run(ctx context.Context, opts ...service.Option) {
 	copts := []client.Option{
 		// client.WithName(name),
 		// client.WithVersion(version),
-		client.WithAddress("localhost:9991"),
+		client.WithAddress(address),
 		// client.WithRegistry(mdns.NewRegistry()),
 		client.WithSecure(secure),
 		client.WithInterceptors(tracing.NewClientInterceptors()),

example/go.mod

@@ -32,6 +32,7 @@ require (
 
 require (
 	cloud.google.com/go/compute/metadata v0.6.0 // indirect
+	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bombsimon/logrusr/v4 v4.1.0 // indirect
 	github.com/bufbuild/protocompile v0.14.1 // indirect
@@ -63,6 +64,7 @@ require (
 	github.com/sirupsen/logrus v1.9.3 // indirect
 	github.com/soheilhy/cmux v0.1.5 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/tailscale/peercred v0.0.0-20250107143737-35a0c7bd7edc // indirect
 	github.com/tmc/grpc-websocket-proxy v0.0.0-20220101234140-673ab2c3ae75 // indirect
 	github.com/traefik/grpc-web v0.16.0 // indirect
 	github.com/uptrace/opentelemetry-go-extra/otellogrus v0.3.2 // indirect

example/go.sum

@@ -35,6 +35,8 @@ cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
+github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@@ -326,6 +328,8 @@ github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o
 github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tailscale/peercred v0.0.0-20250107143737-35a0c7bd7edc h1:24heQPtnFR+yfntqhI3oAu9i27nEojcQ4NuBQOo5ZFA=
+github.com/tailscale/peercred v0.0.0-20250107143737-35a0c7bd7edc/go.mod h1:f93CXfllFsO9ZQVq+Zocb1Gp4G5Fz0b0rXHLOzt/Djc=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20220101234140-673ab2c3ae75 h1:6fotK7otjonDflCTK0BCfls4SPy3NcCVb5dqqmbRknE=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20220101234140-673ab2c3ae75/go.mod h1:KO6IkyS8Y3j8OdNO85qEYBsRPuteD+YciPomcXdrMnk=
 github.com/traefik/grpc-web v0.16.0 h1:eeUWZaFg6ZU0I9dWOYE2D5qkNzRBmXzzuRlxdltascY=

example/server.go

@@ -7,6 +7,7 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/peer"
 
 	"go.linka.cloud/grpc-tookit/example/pb"
 	"go.linka.cloud/grpc-toolkit/interceptors/iface"
@@ -30,6 +31,11 @@ func (g *GreeterHandler) SayHello(ctx context.Context, req *pb.HelloRequest) (*p
 	span := trace.SpanFromContext(ctx)
 	span.SetAttributes(attribute.String("name", req.Name))
 	logger.C(ctx).Infof("replying to %s", req.Name)
+	if p, ok := peer.FromContext(ctx); ok {
+		logger.C(ctx).Infof("peer auth info: %+v", p.AuthInfo)
+	} else {
+		logger.C(ctx).Infof("no peer info")
+	}
 	return &pb.HelloReply{Message: hello(req.Name)}, nil
 }
 

example/service.go

@@ -27,15 +27,12 @@ func newService(ctx context.Context, opts ...service.Option) (service.Service, e
 	log := logger.C(ctx)
 	metrics := metrics2.NewInterceptors(metrics2.WithExemplarFromContext(metrics2.DefaultExemplarFromCtx))
 
-	address := "0.0.0.0:9991"
-
 	var svc service.Service
 	opts = append(opts,
 		service.WithContext(ctx),
-		service.WithAddress(address),
 		// service.WithRegistry(mdns.NewRegistry()),
 		service.WithReflection(true),
-		service.WithoutCmux(),
+		// service.WithoutCmux(),
 		service.WithGateway(pb.RegisterGreeterHandler),
 		service.WithGatewayPrefix("/rest"),
 		service.WithGRPCWeb(true),

go.mod

@@ -5,6 +5,7 @@ go 1.23.0
 toolchain go1.24.3
 
 require (
+	github.com/Microsoft/go-winio v0.6.2
 	github.com/alta/protopatch v0.5.3
 	github.com/bombsimon/logrusr/v4 v4.0.0
 	github.com/caitlinelfring/go-env-default v1.1.0
@@ -56,6 +57,7 @@ require (
 	go.uber.org/multierr v1.7.0
 	golang.org/x/net v0.40.0
 	golang.org/x/sync v0.14.0
+	golang.org/x/sys v0.33.0
 	google.golang.org/genproto/googleapis/api v0.0.0-20250519155744-55703ea1f237
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250519155744-55703ea1f237
 	google.golang.org/grpc v1.72.1
@@ -96,7 +98,6 @@ require (
 	go.opentelemetry.io/proto/otlp v1.6.0 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
 	golang.org/x/mod v0.21.0 // indirect
-	golang.org/x/sys v0.33.0 // indirect
 	golang.org/x/text v0.25.0 // indirect
 	golang.org/x/tools v0.26.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -53,6 +53,8 @@ dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/DataDog/datadog-go v3.2.0+incompatible/go.mod h1:LButxg5PwREeZtORoXG3tL4fMGNddJ+vMq1mwgfaqoQ=
+github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
+github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=

service/listen.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package service
+
+import (
+	"net"
+)
+
+func listen(network, address string) (net.Listener, error) {
+	return net.Listen(network, address)
+}

service/listen_windows.go

@@ -0,0 +1,14 @@
+package service
+
+import (
+	"net"
+
+	"github.com/Microsoft/go-winio"
+)
+
+func listen(network, address string) (net.Listener, error) {
+	if network == "pipe" {
+		return winio.ListenPipe(address, nil)
+	}
+	return net.Listen(network, address)
+}

service/service.go

@@ -139,7 +139,7 @@ func newService(opts ...Option) (*service, error) {
 		grpc.StreamInterceptor(si),
 		grpc.UnaryInterceptor(ui),
 	}
-	if _, ok := s.opts.lis.(*net.UnixListener); ok || strings.HasPrefix(s.opts.address, "unix://") {
+	if _, ok := s.opts.lis.(*net.UnixListener); ok || strings.HasPrefix(s.opts.address, "unix://") || strings.HasPrefix(s.opts.address, `\\.\pipe\`) {
 		gopts = append(gopts, grpc.Creds(peercreds.New()))
 	}
 	s.server = grpc.NewServer(append(gopts, s.opts.serverOpts...)...)
@@ -179,9 +179,12 @@ func (s *service) start() (*errgroup.Group, error) {
 		network = "unix"
 		s.opts.address = strings.TrimPrefix(s.opts.address, "unix://")
 	}
+	if strings.HasPrefix(s.opts.address, `\\.\pipe\`) {
+		network = "pipe"
+	}
 
 	if s.opts.lis == nil {
-		lis, err := net.Listen(network, s.opts.address)
+		lis, err := listen(network, s.opts.address)
 		if err != nil {
 			return nil, err
 		}