Store more information in the kernel socket table.

Store enough information in the kernel socket table to distinguish
between different types of sockets. Previously we were only storing
the socket family, but this isn't enough to classify sockets. For
example, TCPv4 and UDPv4 sockets are both AF_INET, and ICMP sockets
are SOCK_DGRAM sockets with a particular protocol.

Instead of creating more sub-tables, flatten the socket table and
provide a filtering mechanism based on the socket entry.

Also generate and store a socket entry index ("sl" in linux) which
allows us to output entries in a stable order from procfs.

PiperOrigin-RevId: 252495895

1 files changed, 13 insertions, 3 deletions

diff --git a/pkg/sentry/socket/rpcinet/socket.go b/pkg/sentry/socket/rpcinet/socket.go
index 2d5b5b58f..c22ff1ff0 100644
--- a/pkg/sentry/socket/rpcinet/socket.go
+++ b/pkg/sentry/socket/rpcinet/socket.go
@@ -53,7 +53,10 @@ type socketOperations struct {
 	fsutil.FileUseInodeUnstableAttr `state:"nosave"`
 	socket.SendReceiveTimeout
 
-	family   int    // Read-only.
+	family   int            // Read-only.
+	stype    linux.SockType // Read-only.
+	protocol int            // Read-only.
+
 	fd       uint32 // must be O_NONBLOCK
 	wq       *waiter.Queue
 	rpcConn  *conn.RPCConnection
@@ -86,6 +89,8 @@ func newSocketFile(ctx context.Context, stack *Stack, family int, skType linux.S
 	defer dirent.DecRef()
 	return fs.NewFile(ctx, dirent, fs.FileFlags{Read: true, Write: true}, &socketOperations{
 		family:   family,
+		stype:    skType,
+		protocol: protocol,
 		wq:       &wq,
 		fd:       fd,
 		rpcConn:  stack.rpcConn,
@@ -332,7 +337,7 @@ func (s *socketOperations) Accept(t *kernel.Task, peerRequested bool, flags int,
 	if err != nil {
 		return 0, nil, 0, syserr.FromError(err)
 	}
-	t.Kernel().RecordSocket(file, s.family)
+	t.Kernel().RecordSocket(file)
 
 	if peerRequested {
 		return fd, payload.Address.Address, payload.Address.Length, nil
@@ -835,6 +840,11 @@ func (s *socketOperations) State() uint32 {
 	return 0
 }
 
+// Type implements socket.Socket.Type.
+func (s *socketOperations) Type() (family int, skType linux.SockType, protocol int) {
+	return s.family, s.stype, s.protocol
+}
+
 type socketProvider struct {
 	family int
 }
@@ -876,7 +886,7 @@ func (p *socketProvider) Socket(t *kernel.Task, stypeflags linux.SockType, proto
 		return nil, nil
 	}
 
-	return newSocketFile(t, s, p.family, stype, 0)
+	return newSocketFile(t, s, p.family, stype, protocol)
 }
 
 // Pair implements socket.Provider.Pair.