1 files changed, 39 insertions, 26 deletions

diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go
index 56ed63e21..b07e8d67b 100644
--- a/pkg/sentry/socket/unix/unix.go
+++ b/pkg/sentry/socket/unix/unix.go
@@ -17,6 +17,7 @@
 package unix
 
 import (
+	"fmt"
 	"strings"
 	"syscall"
 
@@ -55,22 +56,22 @@ type SocketOperations struct {
 	refs.AtomicRefCount
 	socket.SendReceiveTimeout
 
-	ep       transport.Endpoint
-	isPacket bool
+	ep    transport.Endpoint
+	stype linux.SockType
 }
 
 // New creates a new unix socket.
-func New(ctx context.Context, endpoint transport.Endpoint, isPacket bool) *fs.File {
+func New(ctx context.Context, endpoint transport.Endpoint, stype linux.SockType) *fs.File {
 	dirent := socket.NewDirent(ctx, unixSocketDevice)
 	defer dirent.DecRef()
-	return NewWithDirent(ctx, dirent, endpoint, isPacket, fs.FileFlags{Read: true, Write: true})
+	return NewWithDirent(ctx, dirent, endpoint, stype, fs.FileFlags{Read: true, Write: true})
 }
 
 // NewWithDirent creates a new unix socket using an existing dirent.
-func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, isPacket bool, flags fs.FileFlags) *fs.File {
+func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, stype linux.SockType, flags fs.FileFlags) *fs.File {
 	return fs.NewFile(ctx, d, flags, &SocketOperations{
-		ep:       ep,
-		isPacket: isPacket,
+		ep:    ep,
+		stype: stype,
 	})
 }
 
@@ -88,6 +89,18 @@ func (s *SocketOperations) Release() {
 	s.DecRef()
 }
 
+func (s *SocketOperations) isPacket() bool {
+	switch s.stype {
+	case linux.SOCK_DGRAM, linux.SOCK_SEQPACKET:
+		return true
+	case linux.SOCK_STREAM:
+		return false
+	default:
+		// We shouldn't have allowed any other socket types during creation.
+		panic(fmt.Sprintf("Invalid socket type %d", s.stype))
+	}
+}
+
 // Endpoint extracts the transport.Endpoint.
 func (s *SocketOperations) Endpoint() transport.Endpoint {
 	return s.ep
@@ -193,7 +206,7 @@ func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int,
 		}
 	}
 
-	ns := New(t, ep, s.isPacket)
+	ns := New(t, ep, s.stype)
 	defer ns.DecRef()
 
 	if flags&linux.SOCK_NONBLOCK != 0 {
@@ -221,7 +234,7 @@ func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int,
 		return 0, nil, 0, syserr.FromError(e)
 	}
 
-	t.Kernel().RecordSocket(ns, linux.AF_UNIX)
+	t.Kernel().RecordSocket(ns)
 
 	return fd, addr, addrLen, nil
 }
@@ -487,6 +500,7 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 	peek := flags&linux.MSG_PEEK != 0
 	dontWait := flags&linux.MSG_DONTWAIT != 0
 	waitAll := flags&linux.MSG_WAITALL != 0
+	isPacket := s.isPacket()
 
 	// Calculate the number of FDs for which we have space and if we are
 	// requesting credentials.
@@ -528,8 +542,8 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 			msgFlags |= linux.MSG_CTRUNC
 		}
 
-		if err != nil || dontWait || !waitAll || s.isPacket || n >= dst.NumBytes() {
-			if s.isPacket && n < int64(r.MsgSize) {
+		if err != nil || dontWait || !waitAll || isPacket || n >= dst.NumBytes() {
+			if isPacket && n < int64(r.MsgSize) {
 				msgFlags |= linux.MSG_TRUNC
 			}
 
@@ -570,11 +584,11 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 				total += n
 			}
 
-			if err != nil || !waitAll || s.isPacket || n >= dst.NumBytes() {
+			if err != nil || !waitAll || isPacket || n >= dst.NumBytes() {
 				if total > 0 {
 					err = nil
 				}
-				if s.isPacket && n < int64(r.MsgSize) {
+				if isPacket && n < int64(r.MsgSize) {
 					msgFlags |= linux.MSG_TRUNC
 				}
 				return int(total), msgFlags, from, fromLen, socket.ControlMessages{Unix: r.Control}, syserr.FromError(err)
@@ -601,6 +615,12 @@ func (s *SocketOperations) State() uint32 {
 	return s.ep.State()
 }
 
+// Type implements socket.Socket.Type.
+func (s *SocketOperations) Type() (family int, skType linux.SockType, protocol int) {
+	// Unix domain sockets always have a protocol of 0.
+	return linux.AF_UNIX, s.stype, 0
+}
+
 // provider is a unix domain socket provider.
 type provider struct{}
 
@@ -613,21 +633,16 @@ func (*provider) Socket(t *kernel.Task, stype linux.SockType, protocol int) (*fs
 
 	// Create the endpoint and socket.
 	var ep transport.Endpoint
-	var isPacket bool
 	switch stype {
 	case linux.SOCK_DGRAM:
-		isPacket = true
 		ep = transport.NewConnectionless()
-	case linux.SOCK_SEQPACKET:
-		isPacket = true
-		fallthrough
-	case linux.SOCK_STREAM:
+	case linux.SOCK_SEQPACKET, linux.SOCK_STREAM:
 		ep = transport.NewConnectioned(stype, t.Kernel())
 	default:
 		return nil, syserr.ErrInvalidArgument
 	}
 
-	return New(t, ep, isPacket), nil
+	return New(t, ep, stype), nil
 }
 
 // Pair creates a new pair of AF_UNIX connected sockets.
@@ -637,19 +652,17 @@ func (*provider) Pair(t *kernel.Task, stype linux.SockType, protocol int) (*fs.F
 		return nil, nil, syserr.ErrProtocolNotSupported
 	}
 
-	var isPacket bool
 	switch stype {
-	case linux.SOCK_STREAM:
-	case linux.SOCK_DGRAM, linux.SOCK_SEQPACKET:
-		isPacket = true
+	case linux.SOCK_STREAM, linux.SOCK_DGRAM, linux.SOCK_SEQPACKET:
+		// Ok
 	default:
 		return nil, nil, syserr.ErrInvalidArgument
 	}
 
 	// Create the endpoints and sockets.
 	ep1, ep2 := transport.NewPair(stype, t.Kernel())
-	s1 := New(t, ep1, isPacket)
-	s2 := New(t, ep2, isPacket)
+	s1 := New(t, ep1, stype)
+	s2 := New(t, ep2, stype)
 
 	return s1, s2, nil
 }