Update vfs2 socket TODOs.

Three updates:
- Mark all vfs2 socket syscalls as supported.
- Use the same dev number and ino number generator for all types of sockets,
  unlike in VFS1.
- Do not use host fd for hostinet metadata.

Fixes #1476, #1478, #1484, 1485, #2017.

PiperOrigin-RevId: 309994579

pkg/sentry/fsimpl/sockfs/sockfs.go

@@ -53,9 +53,7 @@ func NewFilesystem(vfsObj *vfs.VirtualFilesystem) *vfs.Filesystem {
 
 // inode implements kernfs.Inode.
 //
-// TODO(gvisor.dev/issue/1476): Add device numbers to this inode (which are
-// not included in InodeAttrs) to store the numbers of the appropriate
-// socket device. Override InodeAttrs.Stat() accordingly.
+// TODO(gvisor.dev/issue/1193): Device numbers.
 type inode struct {
 	kernfs.InodeNotDirectory
 	kernfs.InodeNotSymlink
@@ -69,11 +67,6 @@ func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr
 }
 
 // NewDentry constructs and returns a sockfs dentry.
-//
-// TODO(gvisor.dev/issue/1476): Currently, we are using
-// sockfs.filesystem.NextIno() to get inode numbers. We should use
-// device-specific numbers, so that we are not using the same generator for
-// netstack, unix, etc.
 func NewDentry(creds *auth.Credentials, ino uint64) *vfs.Dentry {
 	// File mode matches net/socket.c:sock_alloc.
 	filemode := linux.FileMode(linux.S_IFSOCK | 0600)

pkg/sentry/socket/hostinet/socket_vfs2.go

@@ -36,8 +36,11 @@ import (
 type socketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
-	// TODO(gvisor.dev/issue/1484): VFS1 stores internal metadata for hostinet.
-	// We should perhaps rely on the host, much like in hostfs.
+
+	// We store metadata for hostinet sockets internally. Technically, we should
+	// access metadata (e.g. through stat, chmod) on the host for correctness,
+	// but this is not very useful for inet socket fds, which do not belong to a
+	// concrete file anyway.
 	vfs.DentryMetadataFileDescriptionImpl
 
 	socketOpsCommon

pkg/sentry/socket/netstack/netstack_vfs2.go

@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs"
 	"gvisor.dev/gvisor/pkg/sentry/inet"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/socket"
 	"gvisor.dev/gvisor/pkg/sentry/socket/netfilter"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserr"
@@ -41,6 +42,8 @@ type SocketVFS2 struct {
 	socketOpsCommon
 }
 
+var _ = socket.SocketVFS2(&SocketVFS2{})
+
 // NewVFS2 creates a new endpoint socket.
 func NewVFS2(t *kernel.Task, family int, skType linux.SockType, protocol int, queue *waiter.Queue, endpoint tcpip.Endpoint) (*vfs.FileDescription, *syserr.Error) {
 	if skType == linux.SOCK_STREAM {

pkg/sentry/socket/unix/unix_vfs2.go

@@ -22,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/socket"
 	"gvisor.dev/gvisor/pkg/sentry/socket/control"
 	"gvisor.dev/gvisor/pkg/sentry/socket/netstack"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
@@ -43,6 +44,8 @@ type SocketVFS2 struct {
 	socketOpsCommon
 }
 
+var _ = socket.SocketVFS2(&SocketVFS2{})
+
 // NewSockfsFile creates a new socket file in the global sockfs mount and
 // returns a corresponding file description.
 func NewSockfsFile(t *kernel.Task, ep transport.Endpoint, stype linux.SockType) (*vfs.FileDescription, *syserr.Error) {

pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go

@@ -44,22 +44,21 @@ func Override(table map[uintptr]kernel.Syscall) {
 	table[32] = syscalls.Supported("dup", Dup)
 	table[33] = syscalls.Supported("dup2", Dup2)
 	delete(table, 40) // sendfile
-	// TODO(gvisor.dev/issue/1485): Port all socket variants to VFS2.
-	table[41] = syscalls.PartiallySupported("socket", Socket, "In process of porting socket syscalls to VFS2.", nil)
-	table[42] = syscalls.PartiallySupported("connect", Connect, "In process of porting socket syscalls to VFS2.", nil)
-	table[43] = syscalls.PartiallySupported("accept", Accept, "In process of porting socket syscalls to VFS2.", nil)
-	table[44] = syscalls.PartiallySupported("sendto", SendTo, "In process of porting socket syscalls to VFS2.", nil)
-	table[45] = syscalls.PartiallySupported("recvfrom", RecvFrom, "In process of porting socket syscalls to VFS2.", nil)
-	table[46] = syscalls.PartiallySupported("sendmsg", SendMsg, "In process of porting socket syscalls to VFS2.", nil)
-	table[47] = syscalls.PartiallySupported("recvmsg", RecvMsg, "In process of porting socket syscalls to VFS2.", nil)
-	table[48] = syscalls.PartiallySupported("shutdown", Shutdown, "In process of porting socket syscalls to VFS2.", nil)
-	table[49] = syscalls.PartiallySupported("bind", Bind, "In process of porting socket syscalls to VFS2.", nil)
-	table[50] = syscalls.PartiallySupported("listen", Listen, "In process of porting socket syscalls to VFS2.", nil)
-	table[51] = syscalls.PartiallySupported("getsockname", GetSockName, "In process of porting socket syscalls to VFS2.", nil)
-	table[52] = syscalls.PartiallySupported("getpeername", GetPeerName, "In process of porting socket syscalls to VFS2.", nil)
-	table[53] = syscalls.PartiallySupported("socketpair", SocketPair, "In process of porting socket syscalls to VFS2.", nil)
-	table[54] = syscalls.PartiallySupported("setsockopt", SetSockOpt, "In process of porting socket syscalls to VFS2.", nil)
-	table[55] = syscalls.PartiallySupported("getsockopt", GetSockOpt, "In process of porting socket syscalls to VFS2.", nil)
+	table[41] = syscalls.Supported("socket", Socket)
+	table[42] = syscalls.Supported("connect", Connect)
+	table[43] = syscalls.Supported("accept", Accept)
+	table[44] = syscalls.Supported("sendto", SendTo)
+	table[45] = syscalls.Supported("recvfrom", RecvFrom)
+	table[46] = syscalls.Supported("sendmsg", SendMsg)
+	table[47] = syscalls.Supported("recvmsg", RecvMsg)
+	table[48] = syscalls.Supported("shutdown", Shutdown)
+	table[49] = syscalls.Supported("bind", Bind)
+	table[50] = syscalls.Supported("listen", Listen)
+	table[51] = syscalls.Supported("getsockname", GetSockName)
+	table[52] = syscalls.Supported("getpeername", GetPeerName)
+	table[53] = syscalls.Supported("socketpair", SocketPair)
+	table[54] = syscalls.Supported("setsockopt", SetSockOpt)
+	table[55] = syscalls.Supported("getsockopt", GetSockOpt)
 	table[59] = syscalls.Supported("execve", Execve)
 	table[72] = syscalls.Supported("fcntl", Fcntl)
 	delete(table, 73) // flock
@@ -145,8 +144,7 @@ func Override(table map[uintptr]kernel.Syscall) {
 	delete(table, 285) // fallocate
 	table[286] = syscalls.Supported("timerfd_settime", TimerfdSettime)
 	table[287] = syscalls.Supported("timerfd_gettime", TimerfdGettime)
-	// TODO(gvisor.dev/issue/1485): Port all socket variants to VFS2.
-	table[288] = syscalls.PartiallySupported("accept4", Accept4, "In process of porting socket syscalls to VFS2.", nil)
+	table[288] = syscalls.Supported("accept4", Accept4)
 	delete(table, 289) // signalfd4
 	table[290] = syscalls.Supported("eventfd2", Eventfd2)
 	table[291] = syscalls.Supported("epoll_create1", EpollCreate1)
@@ -155,11 +153,9 @@ func Override(table map[uintptr]kernel.Syscall) {
 	delete(table, 294) // inotify_init1
 	table[295] = syscalls.Supported("preadv", Preadv)
 	table[296] = syscalls.Supported("pwritev", Pwritev)
-	// TODO(gvisor.dev/issue/1485): Port all socket variants to VFS2.
-	table[299] = syscalls.PartiallySupported("recvmmsg", RecvMMsg, "In process of porting socket syscalls to VFS2.", nil)
+	table[299] = syscalls.Supported("recvmmsg", RecvMMsg)
 	table[306] = syscalls.Supported("syncfs", Syncfs)
-	// TODO(gvisor.dev/issue/1485): Port all socket variants to VFS2.
-	table[307] = syscalls.PartiallySupported("sendmmsg", SendMMsg, "In process of porting socket syscalls to VFS2.", nil)
+	table[307] = syscalls.Supported("sendmmsg", SendMMsg)
 	table[316] = syscalls.Supported("renameat2", Renameat2)
 	delete(table, 319) // memfd_create
 	table[322] = syscalls.Supported("execveat", Execveat)