1 files changed, 336 insertions, 0 deletions
diff --git a/pkg/sentry/socket/socket.go b/pkg/sentry/socket/socket.go
new file mode 100644
index 000000000..9393acd28
--- /dev/null
+++ b/pkg/sentry/socket/socket.go
@@ -0,0 +1,336 @@
+// 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 socket provides the interfaces that need to be provided by socket
+// implementations and providers, as well as per family demultiplexing of socket
+// creation.
+package socket
+
+import (
+	"fmt"
+	"sync/atomic"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/device"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs"
+	ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+	"gvisor.googlesource.com/gvisor/pkg/syserr"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip"
+)
+
+// ControlMessages represents the union of unix control messages and tcpip
+// control messages.
+type ControlMessages struct {
+	Unix transport.ControlMessages
+	IP   tcpip.ControlMessages
+}
+
+// Socket is the interface containing socket syscalls used by the syscall layer
+// to redirect them to the appropriate implementation.
+type Socket interface {
+	fs.FileOperations
+
+	// Connect implements the connect(2) linux syscall.
+	Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error
+
+	// Accept implements the accept4(2) linux syscall.
+	// Returns fd, real peer address length and error. Real peer address
+	// length is only set if len(peer) > 0.
+	Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (kdefs.FD, interface{}, uint32, *syserr.Error)
+
+	// Bind implements the bind(2) linux syscall.
+	Bind(t *kernel.Task, sockaddr []byte) *syserr.Error
+
+	// Listen implements the listen(2) linux syscall.
+	Listen(t *kernel.Task, backlog int) *syserr.Error
+
+	// Shutdown implements the shutdown(2) linux syscall.
+	Shutdown(t *kernel.Task, how int) *syserr.Error
+
+	// GetSockOpt implements the getsockopt(2) linux syscall.
+	GetSockOpt(t *kernel.Task, level int, name int, outLen int) (interface{}, *syserr.Error)
+
+	// SetSockOpt implements the setsockopt(2) linux syscall.
+	SetSockOpt(t *kernel.Task, level int, name int, opt []byte) *syserr.Error
+
+	// GetSockName implements the getsockname(2) linux syscall.
+	//
+	// addrLen is the address length to be returned to the application, not
+	// necessarily the actual length of the address.
+	GetSockName(t *kernel.Task) (addr interface{}, addrLen uint32, err *syserr.Error)
+
+	// GetPeerName implements the getpeername(2) linux syscall.
+	//
+	// addrLen is the address length to be returned to the application, not
+	// necessarily the actual length of the address.
+	GetPeerName(t *kernel.Task) (addr interface{}, addrLen uint32, err *syserr.Error)
+
+	// RecvMsg implements the recvmsg(2) linux syscall.
+	//
+	// senderAddrLen is the address length to be returned to the application,
+	// not necessarily the actual length of the address.
+	//
+	// flags control how RecvMsg should be completed. msgFlags indicate how
+	// the RecvMsg call was completed. Note that control message truncation
+	// may still be required even if the MSG_CTRUNC bit is not set in
+	// msgFlags. In that case, the caller should set MSG_CTRUNC appropriately.
+	//
+	// If err != nil, the recv was not successful.
+	RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (n int, msgFlags int, senderAddr interface{}, senderAddrLen uint32, controlMessages ControlMessages, err *syserr.Error)
+
+	// SendMsg implements the sendmsg(2) linux syscall. SendMsg does not take
+	// ownership of the ControlMessage on error.
+	//
+	// If n > 0, err will either be nil or an error from t.Block.
+	SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages ControlMessages) (n int, err *syserr.Error)
+
+	// SetRecvTimeout sets the timeout (in ns) for recv operations. Zero means
+	// no timeout, and negative means DONTWAIT.
+	SetRecvTimeout(nanoseconds int64)
+
+	// RecvTimeout gets the current timeout (in ns) for recv operations. Zero
+	// means no timeout, and negative means DONTWAIT.
+	RecvTimeout() int64
+
+	// SetSendTimeout sets the timeout (in ns) for send operations. Zero means
+	// no timeout, and negative means DONTWAIT.
+	SetSendTimeout(nanoseconds int64)
+
+	// SendTimeout gets the current timeout (in ns) for send operations. Zero
+	// means no timeout, and negative means DONTWAIT.
+	SendTimeout() int64
+}
+
+// Provider is the interface implemented by providers of sockets for specific
+// address families (e.g., AF_INET).
+type Provider interface {
+	// Socket creates a new socket.
+	//
+	// If a nil Socket _and_ a nil error is returned, it means that the
+	// protocol is not supported. A non-nil error should only be returned
+	// if the protocol is supported, but an error occurs during creation.
+	Socket(t *kernel.Task, stype transport.SockType, protocol int) (*fs.File, *syserr.Error)
+
+	// Pair creates a pair of connected sockets.
+	//
+	// See Socket for error information.
+	Pair(t *kernel.Task, stype transport.SockType, protocol int) (*fs.File, *fs.File, *syserr.Error)
+}
+
+// families holds a map of all known address families and their providers.
+var families = make(map[int][]Provider)
+
+// RegisterProvider registers the provider of a given address family so that
+// sockets of that type can be created via socket() and/or socketpair()
+// syscalls.
+func RegisterProvider(family int, provider Provider) {
+	families[family] = append(families[family], provider)
+}
+
+// New creates a new socket with the given family, type and protocol.
+func New(t *kernel.Task, family int, stype transport.SockType, protocol int) (*fs.File, *syserr.Error) {
+	for _, p := range families[family] {
+		s, err := p.Socket(t, stype, protocol)
+		if err != nil {
+			return nil, err
+		}
+		if s != nil {
+			t.Kernel().RecordSocket(s, family)
+			return s, nil
+		}
+	}
+
+	return nil, syserr.ErrAddressFamilyNotSupported
+}
+
+// Pair creates a new connected socket pair with the given family, type and
+// protocol.
+func Pair(t *kernel.Task, family int, stype transport.SockType, protocol int) (*fs.File, *fs.File, *syserr.Error) {
+	providers, ok := families[family]
+	if !ok {
+		return nil, nil, syserr.ErrAddressFamilyNotSupported
+	}
+
+	for _, p := range providers {
+		s1, s2, err := p.Pair(t, stype, protocol)
+		if err != nil {
+			return nil, nil, err
+		}
+		if s1 != nil && s2 != nil {
+			k := t.Kernel()
+			k.RecordSocket(s1, family)
+			k.RecordSocket(s2, family)
+			return s1, s2, nil
+		}
+	}
+
+	return nil, nil, syserr.ErrSocketNotSupported
+}
+
+// NewDirent returns a sockfs fs.Dirent that resides on device d.
+func NewDirent(ctx context.Context, d *device.Device) *fs.Dirent {
+	ino := d.NextIno()
+	iops := &fsutil.SimpleFileInode{
+		InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, fs.FileOwnerFromContext(ctx), fs.FilePermissions{
+			User: fs.PermMask{Read: true, Write: true},
+		}, linux.SOCKFS_MAGIC),
+	}
+	inode := fs.NewInode(iops, fs.NewPseudoMountSource(), fs.StableAttr{
+		Type:      fs.Socket,
+		DeviceID:  d.DeviceID(),
+		InodeID:   ino,
+		BlockSize: usermem.PageSize,
+	})
+
+	// Dirent name matches net/socket.c:sockfs_dname.
+	return fs.NewDirent(inode, fmt.Sprintf("socket:[%d]", ino))
+}
+
+// SendReceiveTimeout stores timeouts for send and receive calls.
+//
+// It is meant to be embedded into Socket implementations to help satisfy the
+// interface.
+//
+// Care must be taken when copying SendReceiveTimeout as it contains atomic
+// variables.
+//
+// +stateify savable
+type SendReceiveTimeout struct {
+	// send is length of the send timeout in nanoseconds.
+	//
+	// send must be accessed atomically.
+	send int64
+
+	// recv is length of the receive timeout in nanoseconds.
+	//
+	// recv must be accessed atomically.
+	recv int64
+}
+
+// SetRecvTimeout implements Socket.SetRecvTimeout.
+func (to *SendReceiveTimeout) SetRecvTimeout(nanoseconds int64) {
+	atomic.StoreInt64(&to.recv, nanoseconds)
+}
+
+// RecvTimeout implements Socket.RecvTimeout.
+func (to *SendReceiveTimeout) RecvTimeout() int64 {
+	return atomic.LoadInt64(&to.recv)
+}
+
+// SetSendTimeout implements Socket.SetSendTimeout.
+func (to *SendReceiveTimeout) SetSendTimeout(nanoseconds int64) {
+	atomic.StoreInt64(&to.send, nanoseconds)
+}
+
+// SendTimeout implements Socket.SendTimeout.
+func (to *SendReceiveTimeout) SendTimeout() int64 {
+	return atomic.LoadInt64(&to.send)
+}
+
+// GetSockOptEmitUnimplementedEvent emits unimplemented event if name is valid.
+// It contains names that are valid for GetSockOpt when level is SOL_SOCKET.
+func GetSockOptEmitUnimplementedEvent(t *kernel.Task, name int) {
+	switch name {
+	case linux.SO_ACCEPTCONN,
+		linux.SO_BPF_EXTENSIONS,
+		linux.SO_COOKIE,
+		linux.SO_DOMAIN,
+		linux.SO_ERROR,
+		linux.SO_GET_FILTER,
+		linux.SO_INCOMING_NAPI_ID,
+		linux.SO_MEMINFO,
+		linux.SO_PEERCRED,
+		linux.SO_PEERGROUPS,
+		linux.SO_PEERNAME,
+		linux.SO_PEERSEC,
+		linux.SO_PROTOCOL,
+		linux.SO_SNDLOWAT,
+		linux.SO_TYPE:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	default:
+		emitUnimplementedEvent(t, name)
+	}
+}
+
+// SetSockOptEmitUnimplementedEvent emits unimplemented event if name is valid.
+// It contains names that are valid for SetSockOpt when level is SOL_SOCKET.
+func SetSockOptEmitUnimplementedEvent(t *kernel.Task, name int) {
+	switch name {
+	case linux.SO_ATTACH_BPF,
+		linux.SO_ATTACH_FILTER,
+		linux.SO_ATTACH_REUSEPORT_CBPF,
+		linux.SO_ATTACH_REUSEPORT_EBPF,
+		linux.SO_CNX_ADVICE,
+		linux.SO_DETACH_FILTER,
+		linux.SO_RCVBUFFORCE,
+		linux.SO_SNDBUFFORCE:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+
+	default:
+		emitUnimplementedEvent(t, name)
+	}
+}
+
+// emitUnimplementedEvent emits unimplemented event if name is valid. It
+// contains names that are common between Get and SetSocketOpt when level is
+// SOL_SOCKET.
+func emitUnimplementedEvent(t *kernel.Task, name int) {
+	switch name {
+	case linux.SO_BINDTODEVICE,
+		linux.SO_BROADCAST,
+		linux.SO_BSDCOMPAT,
+		linux.SO_BUSY_POLL,
+		linux.SO_DEBUG,
+		linux.SO_DONTROUTE,
+		linux.SO_INCOMING_CPU,
+		linux.SO_KEEPALIVE,
+		linux.SO_LINGER,
+		linux.SO_LOCK_FILTER,
+		linux.SO_MARK,
+		linux.SO_MAX_PACING_RATE,
+		linux.SO_NOFCS,
+		linux.SO_NO_CHECK,
+		linux.SO_OOBINLINE,
+		linux.SO_PASSCRED,
+		linux.SO_PASSSEC,
+		linux.SO_PEEK_OFF,
+		linux.SO_PRIORITY,
+		linux.SO_RCVBUF,
+		linux.SO_RCVLOWAT,
+		linux.SO_RCVTIMEO,
+		linux.SO_REUSEADDR,
+		linux.SO_REUSEPORT,
+		linux.SO_RXQ_OVFL,
+		linux.SO_SELECT_ERR_QUEUE,
+		linux.SO_SNDBUF,
+		linux.SO_SNDTIMEO,
+		linux.SO_TIMESTAMP,
+		linux.SO_TIMESTAMPING,
+		linux.SO_TIMESTAMPNS,
+		linux.SO_TXTIME,
+		linux.SO_WIFI_STATUS,
+		linux.SO_ZEROCOPY:
+
+		t.Kernel().EmitUnimplementedEvent(t)
+	}
+}