Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 88 insertions, 0 deletions

diff --git a/pkg/sentry/socket/unix/io.go b/pkg/sentry/socket/unix/io.go
new file mode 100644
index 000000000..0ca2e35d0
--- /dev/null
+++ b/pkg/sentry/socket/unix/io.go
@@ -0,0 +1,88 @@
+// Copyright 2018 Google Inc.
+//
+// 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.googlesource.com/gvisor/pkg/sentry/safemem"
+	"gvisor.googlesource.com/gvisor/pkg/syserr"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip/transport/unix"
+)
+
+// EndpointWriter implements safemem.Writer that writes to a unix.Endpoint.
+//
+// EndpointWriter is not thread-safe.
+type EndpointWriter struct {
+	// Endpoint is the unix.Endpoint to write to.
+	Endpoint unix.Endpoint
+
+	// Control is the control messages to send.
+	Control unix.ControlMessages
+
+	// To is the endpoint to send to. May be nil.
+	To unix.BoundEndpoint
+}
+
+// WriteFromBlocks implements safemem.Writer.WriteFromBlocks.
+func (w *EndpointWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) {
+	return safemem.FromVecWriterFunc{func(bufs [][]byte) (int64, error) {
+		n, err := w.Endpoint.SendMsg(bufs, w.Control, w.To)
+		if err != nil {
+			return int64(n), syserr.TranslateNetstackError(err).ToError()
+		}
+		return int64(n), nil
+	}}.WriteFromBlocks(srcs)
+}
+
+// EndpointReader implements safemem.Reader that reads from a unix.Endpoint.
+//
+// EndpointReader is not thread-safe.
+type EndpointReader struct {
+	// Endpoint is the unix.Endpoint to read from.
+	Endpoint unix.Endpoint
+
+	// Creds indicates if credential control messages are requested.
+	Creds bool
+
+	// NumRights is the number of SCM_RIGHTS FDs requested.
+	NumRights uintptr
+
+	// Peek indicates that the data should not be consumed from the
+	// endpoint.
+	Peek bool
+
+	// MsgSize is the size of the message that was read from. For stream
+	// sockets, it is the amount read.
+	MsgSize uintptr
+
+	// From, if not nil, will be set with the address read from.
+	From *tcpip.FullAddress
+
+	// Control contains the received control messages.
+	Control unix.ControlMessages
+}
+
+// ReadToBlocks implements safemem.Reader.ReadToBlocks.
+func (r *EndpointReader) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
+	return safemem.FromVecReaderFunc{func(bufs [][]byte) (int64, error) {
+		n, ms, c, err := r.Endpoint.RecvMsg(bufs, r.Creds, r.NumRights, r.Peek, r.From)
+		r.Control = c
+		r.MsgSize = ms
+		if err != nil {
+			return int64(n), syserr.TranslateNetstackError(err).ToError()
+		}
+		return int64(n), nil
+	}}.ReadToBlocks(dsts)
+}