Add FileDescriptionImpl for Unix sockets.

This change involves several steps:
- Refactor the VFS1 unix socket implementation to share methods between VFS1
  and VFS2 where possible. Re-implement the rest.
- Override the default PRead, Read, PWrite, Write, Ioctl, Release methods in
  FileDescriptionDefaultImpl.
- Add functions to create and initialize a new Dentry/Inode and FileDescription
  for a Unix socket file.

Updates #1476

PiperOrigin-RevId: 304689796

1 files changed, 5 insertions, 0 deletions

diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go
index 3e90dc4ed..2f04bf882 100644
--- a/pkg/sentry/vfs/options.go
+++ b/pkg/sentry/vfs/options.go
@@ -16,6 +16,7 @@ package vfs
 
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 )
 
 // GetDentryOptions contains options to VirtualFilesystem.GetDentryAt() and
@@ -44,6 +45,10 @@ type MknodOptions struct {
 	// DevMinor are the major and minor device numbers for the created device.
 	DevMajor uint32
 	DevMinor uint32
+
+	// Endpoint is the endpoint to bind to the created file, if a socket file is
+	// being created for bind(2) on a Unix domain socket.
+	Endpoint transport.BoundEndpoint
 }
 
 // MountFlags contains flags as specified for mount(2), e.g. MS_NOEXEC.