Add notes to relevant tests.

These were out-of-band notes that can help provide additional context
and simplify automated imports.

PiperOrigin-RevId: 293525915

3 files changed, 31 insertions, 2 deletions

diff --git a/pkg/sentry/socket/hostinet/BUILD b/pkg/sentry/socket/hostinet/BUILD
index 5a07d5d0e..023bad156 100644
--- a/pkg/sentry/socket/hostinet/BUILD
+++ b/pkg/sentry/socket/hostinet/BUILD
@@ -10,6 +10,7 @@ go_library(
         "save_restore.go",
         "socket.go",
         "socket_unsafe.go",
+        "sockopt_impl.go",
         "stack.go",
     ],
     visibility = ["//pkg/sentry:internal"],
diff --git a/pkg/sentry/socket/hostinet/socket.go b/pkg/sentry/socket/hostinet/socket.go
index 34f63986f..de76388ac 100644
--- a/pkg/sentry/socket/hostinet/socket.go
+++ b/pkg/sentry/socket/hostinet/socket.go
@@ -285,7 +285,7 @@ func (s *socketOperations) GetSockOpt(t *kernel.Task, level int, name int, outPt
 	}
 
 	// Whitelist options and constrain option length.
-	var optlen int
+	optlen := getSockOptLen(t, level, name)
 	switch level {
 	case linux.SOL_IP:
 		switch name {
@@ -330,7 +330,7 @@ func (s *socketOperations) GetSockOpt(t *kernel.Task, level int, name int, outPt
 // SetSockOpt implements socket.Socket.SetSockOpt.
 func (s *socketOperations) SetSockOpt(t *kernel.Task, level int, name int, opt []byte) *syserr.Error {
 	// Whitelist options and constrain option length.
-	var optlen int
+	optlen := setSockOptLen(t, level, name)
 	switch level {
 	case linux.SOL_IP:
 		switch name {
@@ -353,6 +353,7 @@ func (s *socketOperations) SetSockOpt(t *kernel.Task, level int, name int, opt [
 			optlen = sizeofInt32
 		}
 	}
+
 	if optlen == 0 {
 		// Pretend to accept socket options we don't understand. This seems
 		// dangerous, but it's what netstack does...
diff --git a/pkg/sentry/socket/hostinet/sockopt_impl.go b/pkg/sentry/socket/hostinet/sockopt_impl.go
new file mode 100644
index 000000000..8a783712e
--- /dev/null
+++ b/pkg/sentry/socket/hostinet/sockopt_impl.go
@@ -0,0 +1,27 @@
+// Copyright 2020 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 hostinet
+
+import (
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+)
+
+func getSockOptLen(t *kernel.Task, level, name int) int {
+	return 0 // No custom options.
+}
+
+func setSockOptLen(t *kernel.Task, level, name int) int {
+	return 0 // No custom options.
+}