From 5d87d8865f8771c00b84717d40f27f8f93dda7ca Mon Sep 17 00:00:00 2001 From: Ian Gudger Date: Mon, 10 Dec 2018 17:55:45 -0800 Subject: Implement MSG_WAITALL MSG_WAITALL requests that recv family calls do not perform short reads. It only has an effect for SOCK_STREAM sockets, other types ignore it. PiperOrigin-RevId: 224918540 Change-Id: Id97fbf972f1f7cbd4e08eec0138f8cbdf1c94fe7 --- pkg/sentry/socket/unix/unix.go | 51 +++++++++++++++++++++++++++++++----------- 1 file changed, 38 insertions(+), 13 deletions(-) (limited to 'pkg/sentry/socket/unix') diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go index 4379486cf..11cad411d 100644 --- a/pkg/sentry/socket/unix/unix.go +++ b/pkg/sentry/socket/unix/unix.go @@ -53,19 +53,21 @@ type SocketOperations struct { fsutil.NoopFlush `state:"nosave"` fsutil.NoMMap `state:"nosave"` ep transport.Endpoint + isPacket bool } // New creates a new unix socket. -func New(ctx context.Context, endpoint transport.Endpoint) *fs.File { +func New(ctx context.Context, endpoint transport.Endpoint, isPacket bool) *fs.File { dirent := socket.NewDirent(ctx, unixSocketDevice) defer dirent.DecRef() - return NewWithDirent(ctx, dirent, endpoint, fs.FileFlags{Read: true, Write: true}) + return NewWithDirent(ctx, dirent, endpoint, isPacket, fs.FileFlags{Read: true, Write: true}) } // NewWithDirent creates a new unix socket using an existing dirent. -func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, flags fs.FileFlags) *fs.File { +func NewWithDirent(ctx context.Context, d *fs.Dirent, ep transport.Endpoint, isPacket bool, flags fs.FileFlags) *fs.File { return fs.NewFile(ctx, d, flags, &SocketOperations{ - ep: ep, + ep: ep, + isPacket: isPacket, }) } @@ -188,7 +190,7 @@ func (s *SocketOperations) Accept(t *kernel.Task, peerRequested bool, flags int, } } - ns := New(t, ep) + ns := New(t, ep, s.isPacket) defer ns.DecRef() if flags&linux.SOCK_NONBLOCK != 0 { @@ -471,6 +473,8 @@ func (s *SocketOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (n int, senderAddr interface{}, 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 + waitAll := flags&linux.MSG_WAITALL != 0 // Calculate the number of FDs for which we have space and if we are // requesting credentials. @@ -497,7 +501,8 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags if senderRequested { r.From = &tcpip.FullAddress{} } - if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock || flags&linux.MSG_DONTWAIT != 0 { + var total int64 + if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock || dontWait { var from interface{} var fromLen uint32 if r.From != nil { @@ -506,7 +511,13 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags if trunc { n = int64(r.MsgSize) } - return int(n), from, fromLen, socket.ControlMessages{Unix: r.Control}, syserr.FromError(err) + if err != nil || dontWait || !waitAll || s.isPacket || n >= dst.NumBytes() { + return int(n), from, fromLen, socket.ControlMessages{Unix: r.Control}, syserr.FromError(err) + } + + // Don't overwrite any data we received. + dst = dst.DropFirst64(n) + total += n } // We'll have to block. Register for notification and keep trying to @@ -525,7 +536,13 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags if trunc { n = int64(r.MsgSize) } - return int(n), from, fromLen, socket.ControlMessages{Unix: r.Control}, syserr.FromError(err) + total += n + if err != nil || !waitAll || s.isPacket || n >= dst.NumBytes() { + return int(total), from, fromLen, socket.ControlMessages{Unix: r.Control}, syserr.FromError(err) + } + + // Don't overwrite any data we received. + dst = dst.DropFirst64(n) } if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil { @@ -549,16 +566,21 @@ func (*provider) Socket(t *kernel.Task, stype transport.SockType, protocol int) // Create the endpoint and socket. var ep transport.Endpoint + var isPacket bool switch stype { case linux.SOCK_DGRAM: + isPacket = true ep = transport.NewConnectionless() - case linux.SOCK_STREAM, linux.SOCK_SEQPACKET: + case linux.SOCK_SEQPACKET: + isPacket = true + fallthrough + case linux.SOCK_STREAM: ep = transport.NewConnectioned(stype, t.Kernel()) default: return nil, syserr.ErrInvalidArgument } - return New(t, ep), nil + return New(t, ep, isPacket), nil } // Pair creates a new pair of AF_UNIX connected sockets. @@ -568,16 +590,19 @@ func (*provider) Pair(t *kernel.Task, stype transport.SockType, protocol int) (* return nil, nil, syserr.ErrInvalidArgument } + var isPacket bool switch stype { - case linux.SOCK_STREAM, linux.SOCK_DGRAM, linux.SOCK_SEQPACKET: + case linux.SOCK_STREAM: + case linux.SOCK_DGRAM, linux.SOCK_SEQPACKET: + isPacket = true default: return nil, nil, syserr.ErrInvalidArgument } // Create the endpoints and sockets. ep1, ep2 := transport.NewPair(stype, t.Kernel()) - s1 := New(t, ep1) - s2 := New(t, ep2) + s1 := New(t, ep1, isPacket) + s2 := New(t, ep2, isPacket) return s1, s2, nil } -- cgit v1.2.3