diff options
author | Dean Deng <deandeng@google.com> | 2020-04-03 14:07:42 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-04-03 14:08:54 -0700 |
commit | 5818663ebe26857845685702d99db41c7aa2cf3d (patch) | |
tree | 36337a4b8c1cd0577f29dfacd0fcfdac84c85aee /pkg | |
parent | a94309628ebbc2e6c4997890f1b966fa7a16be20 (diff) |
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
Diffstat (limited to 'pkg')
-rw-r--r-- | pkg/sentry/fsimpl/sockfs/BUILD | 1 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/sockfs/sockfs.go | 29 | ||||
-rw-r--r-- | pkg/sentry/kernel/BUILD | 1 | ||||
-rw-r--r-- | pkg/sentry/socket/netstack/netstack.go | 8 | ||||
-rw-r--r-- | pkg/sentry/socket/unix/BUILD | 4 | ||||
-rw-r--r-- | pkg/sentry/socket/unix/unix.go | 89 | ||||
-rw-r--r-- | pkg/sentry/socket/unix/unix_vfs2.go | 348 | ||||
-rw-r--r-- | pkg/sentry/vfs/options.go | 5 |
8 files changed, 456 insertions, 29 deletions
diff --git a/pkg/sentry/fsimpl/sockfs/BUILD b/pkg/sentry/fsimpl/sockfs/BUILD index 790d50e65..52084ddb5 100644 --- a/pkg/sentry/fsimpl/sockfs/BUILD +++ b/pkg/sentry/fsimpl/sockfs/BUILD @@ -7,6 +7,7 @@ go_library( srcs = ["sockfs.go"], visibility = ["//pkg/sentry:internal"], deps = [ + "//pkg/abi/linux", "//pkg/context", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel/auth", diff --git a/pkg/sentry/fsimpl/sockfs/sockfs.go b/pkg/sentry/fsimpl/sockfs/sockfs.go index c13511de2..3f7ad1d65 100644 --- a/pkg/sentry/fsimpl/sockfs/sockfs.go +++ b/pkg/sentry/fsimpl/sockfs/sockfs.go @@ -16,6 +16,7 @@ package sockfs import ( + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" @@ -60,6 +61,10 @@ type filesystem struct { } // 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. type inode struct { kernfs.InodeNotDirectory kernfs.InodeNotSymlink @@ -71,3 +76,27 @@ type inode struct { func (i *inode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { return nil, syserror.ENXIO } + +// InitSocket initializes a socket FileDescription, with a corresponding +// Dentry in mnt. +// +// fd should be the FileDescription associated with socketImpl, i.e. its first +// field. mnt should be the global socket mount, Kernel.socketMount. +func InitSocket(socketImpl vfs.FileDescriptionImpl, fd *vfs.FileDescription, mnt *vfs.Mount, creds *auth.Credentials) error { + fsimpl := mnt.Filesystem().Impl() + fs := fsimpl.(*kernfs.Filesystem) + + // File mode matches net/socket.c:sock_alloc. + filemode := linux.FileMode(linux.S_IFSOCK | 0600) + i := &inode{} + i.Init(creds, fs.NextIno(), filemode) + + d := &kernfs.Dentry{} + d.Init(i) + + opts := &vfs.FileDescriptionOptions{UseDentryMetadata: true} + if err := fd.Init(socketImpl, linux.O_RDWR, mnt, d.VFSDentry(), opts); err != nil { + return err + } + return nil +} diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index bb7e3cbc3..e0ff58d8c 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -169,6 +169,7 @@ go_library( "//pkg/sentry/fs/lock", "//pkg/sentry/fs/timerfd", "//pkg/sentry/fsbridge", + "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/fsimpl/sockfs", "//pkg/sentry/hostcpu", "//pkg/sentry/inet", diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 06a5b53bc..5d0085462 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -940,7 +940,7 @@ func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr us // GetSockOpt can be used to implement the linux syscall getsockopt(2) for // sockets backed by a commonEndpoint. -func GetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, level, name, outLen int) (interface{}, *syserr.Error) { +func GetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, family int, skType linux.SockType, level, name, outLen int) (interface{}, *syserr.Error) { switch level { case linux.SOL_SOCKET: return getSockOptSocket(t, s, ep, family, skType, name, outLen) @@ -966,7 +966,7 @@ func GetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, } // getSockOptSocket implements GetSockOpt when level is SOL_SOCKET. -func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, name, outLen int) (interface{}, *syserr.Error) { +func getSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, family int, skType linux.SockType, name, outLen int) (interface{}, *syserr.Error) { // TODO(b/124056281): Stop rejecting short optLen values in getsockopt. switch name { case linux.SO_ERROR: @@ -1541,7 +1541,7 @@ func (s *SocketOperations) SetSockOpt(t *kernel.Task, level int, name int, optVa // SetSockOpt can be used to implement the linux syscall setsockopt(2) for // sockets backed by a commonEndpoint. -func SetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, level int, name int, optVal []byte) *syserr.Error { +func SetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, level int, name int, optVal []byte) *syserr.Error { switch level { case linux.SOL_SOCKET: return setSockOptSocket(t, s, ep, name, optVal) @@ -1568,7 +1568,7 @@ func SetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, level int, n } // setSockOptSocket implements SetSockOpt when level is SOL_SOCKET. -func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name int, optVal []byte) *syserr.Error { +func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name int, optVal []byte) *syserr.Error { switch name { case linux.SO_SNDBUF: if len(optVal) < sizeOfInt32 { diff --git a/pkg/sentry/socket/unix/BUILD b/pkg/sentry/socket/unix/BUILD index 08743deba..de2cc4bdf 100644 --- a/pkg/sentry/socket/unix/BUILD +++ b/pkg/sentry/socket/unix/BUILD @@ -8,23 +8,27 @@ go_library( "device.go", "io.go", "unix.go", + "unix_vfs2.go", ], visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/fspath", "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/device", "//pkg/sentry/fs", "//pkg/sentry/fs/fsutil", + "//pkg/sentry/fsimpl/sockfs", "//pkg/sentry/kernel", "//pkg/sentry/kernel/time", "//pkg/sentry/socket", "//pkg/sentry/socket/control", "//pkg/sentry/socket/netstack", "//pkg/sentry/socket/unix/transport", + "//pkg/sentry/vfs", "//pkg/syserr", "//pkg/syserror", "//pkg/tcpip", diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go index 4d30aa714..7c64f30fa 100644 --- a/pkg/sentry/socket/unix/unix.go +++ b/pkg/sentry/socket/unix/unix.go @@ -23,6 +23,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -33,6 +34,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/socket/control" "gvisor.dev/gvisor/pkg/sentry/socket/netstack" "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" + "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/tcpip" @@ -52,11 +54,8 @@ type SocketOperations struct { fsutil.FileNoSplice `state:"nosave"` fsutil.FileNoopFlush `state:"nosave"` fsutil.FileUseInodeUnstableAttr `state:"nosave"` - refs.AtomicRefCount - socket.SendReceiveTimeout - ep transport.Endpoint - stype linux.SockType + socketOpsCommon } // New creates a new unix socket. @@ -75,16 +74,29 @@ func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, sty } s := SocketOperations{ - ep: ep, - stype: stype, + socketOpsCommon: socketOpsCommon{ + ep: ep, + stype: stype, + }, } s.EnableLeakCheck("unix.SocketOperations") return fs.NewFile(ctx, d, flags, &s) } +// socketOpsCommon contains the socket operations common to VFS1 and VFS2. +// +// +stateify savable +type socketOpsCommon struct { + refs.AtomicRefCount + socket.SendReceiveTimeout + + ep transport.Endpoint + stype linux.SockType +} + // DecRef implements RefCounter.DecRef. -func (s *SocketOperations) DecRef() { +func (s *socketOpsCommon) DecRef() { s.DecRefWithDestructor(func() { s.ep.Close() }) @@ -97,7 +109,7 @@ func (s *SocketOperations) Release() { s.DecRef() } -func (s *SocketOperations) isPacket() bool { +func (s *socketOpsCommon) isPacket() bool { switch s.stype { case linux.SOCK_DGRAM, linux.SOCK_SEQPACKET: return true @@ -110,7 +122,7 @@ func (s *SocketOperations) isPacket() bool { } // Endpoint extracts the transport.Endpoint. -func (s *SocketOperations) Endpoint() transport.Endpoint { +func (s *socketOpsCommon) Endpoint() transport.Endpoint { return s.ep } @@ -143,7 +155,7 @@ func extractPath(sockaddr []byte) (string, *syserr.Error) { // GetPeerName implements the linux syscall getpeername(2) for sockets backed by // a transport.Endpoint. -func (s *SocketOperations) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) { +func (s *socketOpsCommon) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) { addr, err := s.ep.GetRemoteAddress() if err != nil { return nil, 0, syserr.TranslateNetstackError(err) @@ -155,7 +167,7 @@ func (s *SocketOperations) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, // GetSockName implements the linux syscall getsockname(2) for sockets backed by // a transport.Endpoint. -func (s *SocketOperations) GetSockName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) { +func (s *socketOpsCommon) GetSockName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error) { addr, err := s.ep.GetLocalAddress() if err != nil { return nil, 0, syserr.TranslateNetstackError(err) @@ -178,7 +190,7 @@ func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr us // Listen implements the linux syscall listen(2) for sockets backed by // a transport.Endpoint. -func (s *SocketOperations) Listen(t *kernel.Task, backlog int) *syserr.Error { +func (s *socketOpsCommon) Listen(t *kernel.Task, backlog int) *syserr.Error { return s.ep.Listen(backlog) } @@ -310,6 +322,8 @@ func (s *SocketOperations) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error { } // Create the socket. + // + // TODO(gvisor.dev/issue/2324): Correctly set file permissions. childDir, err := d.Bind(t, t.FSContext().RootDirectory(), name, bep, fs.FilePermissions{User: fs.PermMask{Read: true}}) if err != nil { return syserr.ErrPortInUse @@ -345,6 +359,31 @@ func extractEndpoint(t *kernel.Task, sockaddr []byte) (transport.BoundEndpoint, return ep, nil } + if kernel.VFS2Enabled { + p := fspath.Parse(path) + root := t.FSContext().RootDirectoryVFS2() + start := root + relPath := !p.Absolute + if relPath { + start = t.FSContext().WorkingDirectoryVFS2() + } + pop := vfs.PathOperation{ + Root: root, + Start: start, + Path: p, + FollowFinalSymlink: true, + } + ep, e := t.Kernel().VFS().BoundEndpointAt(t, t.Credentials(), &pop) + root.DecRef() + if relPath { + start.DecRef() + } + if e != nil { + return nil, syserr.FromError(e) + } + return ep, nil + } + // Find the node in the filesystem. root := t.FSContext().RootDirectory() cwd := t.FSContext().WorkingDirectory() @@ -363,12 +402,11 @@ func extractEndpoint(t *kernel.Task, sockaddr []byte) (transport.BoundEndpoint, // No socket! return nil, syserr.ErrConnectionRefused } - return ep, nil } // Connect implements the linux syscall connect(2) for unix sockets. -func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error { +func (s *socketOpsCommon) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error { ep, err := extractEndpoint(t, sockaddr) if err != nil { return err @@ -379,7 +417,7 @@ func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking boo return s.ep.Connect(t, ep) } -// Writev implements fs.FileOperations.Write. +// Write implements fs.FileOperations.Write. func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) { t := kernel.TaskFromContext(ctx) ctrl := control.New(t, s.ep, nil) @@ -399,7 +437,7 @@ func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IO // SendMsg implements the linux syscall sendmsg(2) for unix sockets backed by // a transport.Endpoint. -func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) { +func (s *socketOpsCommon) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) { w := EndpointWriter{ Ctx: t, Endpoint: s.ep, @@ -453,27 +491,27 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to [] } // Passcred implements transport.Credentialer.Passcred. -func (s *SocketOperations) Passcred() bool { +func (s *socketOpsCommon) Passcred() bool { return s.ep.Passcred() } // ConnectedPasscred implements transport.Credentialer.ConnectedPasscred. -func (s *SocketOperations) ConnectedPasscred() bool { +func (s *socketOpsCommon) ConnectedPasscred() bool { return s.ep.ConnectedPasscred() } // Readiness implements waiter.Waitable.Readiness. -func (s *SocketOperations) Readiness(mask waiter.EventMask) waiter.EventMask { +func (s *socketOpsCommon) Readiness(mask waiter.EventMask) waiter.EventMask { return s.ep.Readiness(mask) } // EventRegister implements waiter.Waitable.EventRegister. -func (s *SocketOperations) EventRegister(e *waiter.Entry, mask waiter.EventMask) { +func (s *socketOpsCommon) EventRegister(e *waiter.Entry, mask waiter.EventMask) { s.ep.EventRegister(e, mask) } // EventUnregister implements waiter.Waitable.EventUnregister. -func (s *SocketOperations) EventUnregister(e *waiter.Entry) { +func (s *socketOpsCommon) EventUnregister(e *waiter.Entry) { s.ep.EventUnregister(e) } @@ -485,7 +523,7 @@ func (s *SocketOperations) SetSockOpt(t *kernel.Task, level int, name int, optVa // Shutdown implements the linux syscall shutdown(2) for sockets backed by // a transport.Endpoint. -func (s *SocketOperations) Shutdown(t *kernel.Task, how int) *syserr.Error { +func (s *socketOpsCommon) Shutdown(t *kernel.Task, how int) *syserr.Error { f, err := netstack.ConvertShutdown(how) if err != nil { return err @@ -511,7 +549,7 @@ func (s *SocketOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS // RecvMsg implements the linux syscall recvmsg(2) for sockets backed by // a transport.Endpoint. -func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (n int, msgFlags int, senderAddr linux.SockAddr, senderAddrLen uint32, controlMessages socket.ControlMessages, err *syserr.Error) { +func (s *socketOpsCommon) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (n int, msgFlags int, senderAddr linux.SockAddr, senderAddrLen uint32, controlMessages socket.ControlMessages, err *syserr.Error) { trunc := flags&linux.MSG_TRUNC != 0 peek := flags&linux.MSG_PEEK != 0 dontWait := flags&linux.MSG_DONTWAIT != 0 @@ -648,12 +686,12 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags } // State implements socket.Socket.State. -func (s *SocketOperations) State() uint32 { +func (s *socketOpsCommon) State() uint32 { return s.ep.State() } // Type implements socket.Socket.Type. -func (s *SocketOperations) Type() (family int, skType linux.SockType, protocol int) { +func (s *socketOpsCommon) Type() (family int, skType linux.SockType, protocol int) { // Unix domain sockets always have a protocol of 0. return linux.AF_UNIX, s.stype, 0 } @@ -706,4 +744,5 @@ func (*provider) Pair(t *kernel.Task, stype linux.SockType, protocol int) (*fs.F func init() { socket.RegisterProvider(linux.AF_UNIX, &provider{}) + socket.RegisterProviderVFS2(linux.AF_UNIX, &providerVFS2{}) } diff --git a/pkg/sentry/socket/unix/unix_vfs2.go b/pkg/sentry/socket/unix/unix_vfs2.go new file mode 100644 index 000000000..ca1388e2c --- /dev/null +++ b/pkg/sentry/socket/unix/unix_vfs2.go @@ -0,0 +1,348 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package unix + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/socket/control" + "gvisor.dev/gvisor/pkg/sentry/socket/netstack" + "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserr" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/pkg/waiter" +) + +// SocketVFS2 implements socket.SocketVFS2 (and by extension, +// vfs.FileDescriptionImpl) for Unix sockets. +type SocketVFS2 struct { + vfsfd vfs.FileDescription + vfs.FileDescriptionDefaultImpl + vfs.DentryMetadataFileDescriptionImpl + + socketOpsCommon +} + +// NewVFS2File creates and returns a new vfs.FileDescription for a unix socket. +func NewVFS2File(t *kernel.Task, ep transport.Endpoint, stype linux.SockType) (*vfs.FileDescription, *syserr.Error) { + sock := NewFDImpl(ep, stype) + vfsfd := &sock.vfsfd + if err := sockfs.InitSocket(sock, vfsfd, t.Kernel().SocketMount(), t.Credentials()); err != nil { + return nil, syserr.FromError(err) + } + return vfsfd, nil +} + +// NewFDImpl creates and returns a new SocketVFS2. +func NewFDImpl(ep transport.Endpoint, stype linux.SockType) *SocketVFS2 { + // You can create AF_UNIX, SOCK_RAW sockets. They're the same as + // SOCK_DGRAM and don't require CAP_NET_RAW. + if stype == linux.SOCK_RAW { + stype = linux.SOCK_DGRAM + } + + return &SocketVFS2{ + socketOpsCommon: socketOpsCommon{ + ep: ep, + stype: stype, + }, + } +} + +// GetSockOpt implements the linux syscall getsockopt(2) for sockets backed by +// a transport.Endpoint. +func (s *SocketVFS2) GetSockOpt(t *kernel.Task, level int, name int, outPtr usermem.Addr, outLen int) (interface{}, *syserr.Error) { + return netstack.GetSockOpt(t, s, s.ep, linux.AF_UNIX, s.ep.Type(), level, name, outLen) +} + +// blockingAccept implements a blocking version of accept(2), that is, if no +// connections are ready to be accept, it will block until one becomes ready. +func (s *SocketVFS2) blockingAccept(t *kernel.Task) (transport.Endpoint, *syserr.Error) { + // Register for notifications. + e, ch := waiter.NewChannelEntry(nil) + s.socketOpsCommon.EventRegister(&e, waiter.EventIn) + defer s.socketOpsCommon.EventUnregister(&e) + + // Try to accept the connection; if it fails, then wait until we get a + // notification. + for { + if ep, err := s.ep.Accept(); err != syserr.ErrWouldBlock { + return ep, err + } + + if err := t.Block(ch); err != nil { + return nil, syserr.FromError(err) + } + } +} + +// Accept implements the linux syscall accept(2) for sockets backed by +// a transport.Endpoint. +func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error) { + // Issue the accept request to get the new endpoint. + ep, err := s.ep.Accept() + if err != nil { + if err != syserr.ErrWouldBlock || !blocking { + return 0, nil, 0, err + } + + var err *syserr.Error + ep, err = s.blockingAccept(t) + if err != nil { + return 0, nil, 0, err + } + } + + // We expect this to be a FileDescription here. + ns, err := NewVFS2File(t, ep, s.stype) + if err != nil { + return 0, nil, 0, err + } + defer ns.DecRef() + + if flags&linux.SOCK_NONBLOCK != 0 { + ns.SetStatusFlags(t, t.Credentials(), linux.SOCK_NONBLOCK) + } + + var addr linux.SockAddr + var addrLen uint32 + if peerRequested { + // Get address of the peer. + var err *syserr.Error + addr, addrLen, err = ns.Impl().(*SocketVFS2).GetPeerName(t) + if err != nil { + return 0, nil, 0, err + } + } + + fd, e := t.NewFDFromVFS2(0, ns, kernel.FDFlags{ + CloseOnExec: flags&linux.SOCK_CLOEXEC != 0, + }) + if e != nil { + return 0, nil, 0, syserr.FromError(e) + } + + // TODO: add vfs2 sockets to global table. + return fd, addr, addrLen, nil +} + +// Bind implements the linux syscall bind(2) for unix sockets. +func (s *SocketVFS2) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error { + p, e := extractPath(sockaddr) + if e != nil { + return e + } + + bep, ok := s.ep.(transport.BoundEndpoint) + if !ok { + // This socket can't be bound. + return syserr.ErrInvalidArgument + } + + return s.ep.Bind(tcpip.FullAddress{Addr: tcpip.Address(p)}, func() *syserr.Error { + // Is it abstract? + if p[0] == 0 { + if t.IsNetworkNamespaced() { + return syserr.ErrInvalidEndpointState + } + if err := t.AbstractSockets().Bind(p[1:], bep, s); err != nil { + // syserr.ErrPortInUse corresponds to EADDRINUSE. + return syserr.ErrPortInUse + } + } else { + path := fspath.Parse(p) + root := t.FSContext().RootDirectoryVFS2() + defer root.DecRef() + start := root + relPath := !path.Absolute + if relPath { + start = t.FSContext().WorkingDirectoryVFS2() + defer start.DecRef() + } + pop := vfs.PathOperation{ + Root: root, + Start: start, + Path: path, + } + err := t.Kernel().VFS().MknodAt(t, t.Credentials(), &pop, &vfs.MknodOptions{ + // TODO(gvisor.dev/issue/2324): The file permissions should be taken + // from s and t.FSContext().Umask() (see net/unix/af_unix.c:unix_bind), + // but VFS1 just always uses 0400. Resolve this inconsistency. + Mode: linux.S_IFSOCK | 0400, + Endpoint: bep, + }) + if err == syserror.EEXIST { + return syserr.ErrAddressInUse + } + return syserr.FromError(err) + } + + return nil + }) +} + +// Ioctl implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) { + return netstack.Ioctl(ctx, s.ep, uio, args) +} + +// PRead implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + return 0, syserror.ESPIPE +} + +// Read implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + // All flags other than RWF_NOWAIT should be ignored. + // TODO(gvisor.dev/issue/1476): Support RWF_NOWAIT. + if opts.Flags != 0 { + return 0, syserror.EOPNOTSUPP + } + + if dst.NumBytes() == 0 { + return 0, nil + } + return dst.CopyOutFrom(ctx, &EndpointReader{ + Ctx: ctx, + Endpoint: s.ep, + NumRights: 0, + Peek: false, + From: nil, + }) +} + +// PWrite implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { + return 0, syserror.ESPIPE +} + +// Write implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { + // All flags other than RWF_NOWAIT should be ignored. + // TODO(gvisor.dev/issue/1476): Support RWF_NOWAIT. + if opts.Flags != 0 { + return 0, syserror.EOPNOTSUPP + } + + t := kernel.TaskFromContext(ctx) + ctrl := control.New(t, s.ep, nil) + + if src.NumBytes() == 0 { + nInt, err := s.ep.SendMsg(ctx, [][]byte{}, ctrl, nil) + return int64(nInt), err.ToError() + } + + return src.CopyInTo(ctx, &EndpointWriter{ + Ctx: ctx, + Endpoint: s.ep, + Control: ctrl, + To: nil, + }) +} + +// Release implements vfs.FileDescriptionImpl. +func (s *SocketVFS2) Release() { + // Release only decrements a reference on s because s may be referenced in + // the abstract socket namespace. + s.DecRef() +} + +// Readiness implements waiter.Waitable.Readiness. +func (s *SocketVFS2) Readiness(mask waiter.EventMask) waiter.EventMask { + return s.socketOpsCommon.Readiness(mask) +} + +// EventRegister implements waiter.Waitable.EventRegister. +func (s *SocketVFS2) EventRegister(e *waiter.Entry, mask waiter.EventMask) { + s.socketOpsCommon.EventRegister(e, mask) +} + +// EventUnregister implements waiter.Waitable.EventUnregister. +func (s *SocketVFS2) EventUnregister(e *waiter.Entry) { + s.socketOpsCommon.EventUnregister(e) +} + +// SetSockOpt implements the linux syscall setsockopt(2) for sockets backed by +// a transport.Endpoint. +func (s *SocketVFS2) SetSockOpt(t *kernel.Task, level int, name int, optVal []byte) *syserr.Error { + return netstack.SetSockOpt(t, s, s.ep, level, name, optVal) +} + +// providerVFS2 is a unix domain socket provider for VFS2. +type providerVFS2 struct{} + +func (*providerVFS2) Socket(t *kernel.Task, stype linux.SockType, protocol int) (*vfs.FileDescription, *syserr.Error) { + // Check arguments. + if protocol != 0 && protocol != linux.AF_UNIX /* PF_UNIX */ { + return nil, syserr.ErrProtocolNotSupported + } + + // Create the endpoint and socket. + var ep transport.Endpoint + switch stype { + case linux.SOCK_DGRAM, linux.SOCK_RAW: + ep = transport.NewConnectionless(t) + case linux.SOCK_SEQPACKET, linux.SOCK_STREAM: + ep = transport.NewConnectioned(t, stype, t.Kernel()) + default: + return nil, syserr.ErrInvalidArgument + } + + f, err := NewVFS2File(t, ep, stype) + if err != nil { + ep.Close() + return nil, err + } + return f, nil +} + +// Pair creates a new pair of AF_UNIX connected sockets. +func (*providerVFS2) Pair(t *kernel.Task, stype linux.SockType, protocol int) (*vfs.FileDescription, *vfs.FileDescription, *syserr.Error) { + // Check arguments. + if protocol != 0 && protocol != linux.AF_UNIX /* PF_UNIX */ { + return nil, nil, syserr.ErrProtocolNotSupported + } + + switch stype { + case linux.SOCK_STREAM, linux.SOCK_DGRAM, linux.SOCK_SEQPACKET, linux.SOCK_RAW: + // Ok + default: + return nil, nil, syserr.ErrInvalidArgument + } + + // Create the endpoints and sockets. + ep1, ep2 := transport.NewPair(t, stype, t.Kernel()) + s1, err := NewVFS2File(t, ep1, stype) + if err != nil { + ep1.Close() + ep2.Close() + return nil, nil, err + } + s2, err := NewVFS2File(t, ep2, stype) + if err != nil { + s1.DecRef() + ep2.Close() + return nil, nil, err + } + + return s1, s2, nil +} 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. |