[lisa] Implement lisafs protocol methods in VFS2 gofer client and fsgofer.

Introduces RPC methods in lisafs. Makes that gofer client use lisafs RPCs
instead of p9 when lisafs is enabled.

Implements the handlers for those methods in fsgofer.

Fixes #5465

PiperOrigin-RevId: 398080310

1 files changed, 27 insertions, 18 deletions

diff --git a/pkg/sentry/fsimpl/gofer/socket.go b/pkg/sentry/fsimpl/gofer/socket.go
index fe15f8583..86ab70453 100644
--- a/pkg/sentry/fsimpl/gofer/socket.go
+++ b/pkg/sentry/fsimpl/gofer/socket.go
@@ -59,11 +59,6 @@ func sockTypeToP9(t linux.SockType) (p9.ConnectFlags, bool) {
 
 // BidirectionalConnect implements ConnectableEndpoint.BidirectionalConnect.
 func (e *endpoint) BidirectionalConnect(ctx context.Context, ce transport.ConnectingEndpoint, returnConnect func(transport.Receiver, transport.ConnectedEndpoint)) *syserr.Error {
-	cf, ok := sockTypeToP9(ce.Type())
-	if !ok {
-		return syserr.ErrConnectionRefused
-	}
-
 	// No lock ordering required as only the ConnectingEndpoint has a mutex.
 	ce.Lock()
 
@@ -77,7 +72,7 @@ func (e *endpoint) BidirectionalConnect(ctx context.Context, ce transport.Connec
 		return syserr.ErrInvalidEndpointState
 	}
 
-	c, err := e.newConnectedEndpoint(ctx, cf, ce.WaiterQueue())
+	c, err := e.newConnectedEndpoint(ctx, ce.Type(), ce.WaiterQueue())
 	if err != nil {
 		ce.Unlock()
 		return err
@@ -95,7 +90,7 @@ func (e *endpoint) BidirectionalConnect(ctx context.Context, ce transport.Connec
 // UnidirectionalConnect implements
 // transport.BoundEndpoint.UnidirectionalConnect.
 func (e *endpoint) UnidirectionalConnect(ctx context.Context) (transport.ConnectedEndpoint, *syserr.Error) {
-	c, err := e.newConnectedEndpoint(ctx, p9.DgramSocket, &waiter.Queue{})
+	c, err := e.newConnectedEndpoint(ctx, linux.SOCK_DGRAM, &waiter.Queue{})
 	if err != nil {
 		return nil, err
 	}
@@ -111,25 +106,39 @@ func (e *endpoint) UnidirectionalConnect(ctx context.Context) (transport.Connect
 	return c, nil
 }
 
-func (e *endpoint) newConnectedEndpoint(ctx context.Context, flags p9.ConnectFlags, queue *waiter.Queue) (*host.SCMConnectedEndpoint, *syserr.Error) {
-	hostFile, err := e.dentry.file.connect(ctx, flags)
-	if err != nil {
+func (e *endpoint) newConnectedEndpoint(ctx context.Context, sockType linux.SockType, queue *waiter.Queue) (*host.SCMConnectedEndpoint, *syserr.Error) {
+	if e.dentry.fs.opts.lisaEnabled {
+		hostSockFD, err := e.dentry.controlFDLisa.Connect(ctx, sockType)
+		if err != nil {
+			return nil, syserr.ErrConnectionRefused
+		}
+
+		c, serr := host.NewSCMEndpoint(ctx, hostSockFD, queue, e.path)
+		if serr != nil {
+			unix.Close(hostSockFD)
+			log.Warningf("Gofer returned invalid host socket for BidirectionalConnect; file %+v sockType %d: %v", e.dentry.file, sockType, serr)
+			return nil, serr
+		}
+		return c, nil
+	}
+
+	flags, ok := sockTypeToP9(sockType)
+	if !ok {
 		return nil, syserr.ErrConnectionRefused
 	}
-	// Dup the fd so that the new endpoint can manage its lifetime.
-	hostFD, err := unix.Dup(hostFile.FD())
+	hostFile, err := e.dentry.file.connect(ctx, flags)
 	if err != nil {
-		log.Warningf("Could not dup host socket fd %d: %v", hostFile.FD(), err)
-		return nil, syserr.FromError(err)
+		return nil, syserr.ErrConnectionRefused
 	}
-	// After duplicating, we no longer need hostFile.
-	hostFile.Close()
 
-	c, serr := host.NewSCMEndpoint(ctx, hostFD, queue, e.path)
+	c, serr := host.NewSCMEndpoint(ctx, hostFile.FD(), queue, e.path)
 	if serr != nil {
-		log.Warningf("Gofer returned invalid host socket for BidirectionalConnect; file %+v flags %+v: %v", e.dentry.file, flags, serr)
+		hostFile.Close()
+		log.Warningf("Gofer returned invalid host socket for BidirectionalConnect; file %+v sockType %d: %v", e.dentry.file, sockType, serr)
 		return nil, serr
 	}
+	// Ownership has been transferred to c.
+	hostFile.Release()
 	return c, nil
 }