Stub out SO_OOBINLINE.

We don't explicitly support out-of-band data and treat it like normal in-band
data. This is equilivent to SO_OOBINLINE being enabled, so always report that
it is enabled.

PiperOrigin-RevId: 226572742
Change-Id: I4c30ccb83265e76c30dea631cbf86822e6ee1c1b

pkg/sentry/socket/epsocket/epsocket.go

@@ -678,6 +678,18 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
 
 		return int32(v), nil
 
+	case linux.SO_OOBINLINE:
+		if outLen < sizeOfInt32 {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		var v tcpip.OutOfBandInlineOption
+		if err := ep.GetSockOpt(&v); err != nil {
+			return nil, syserr.TranslateNetstackError(err)
+		}
+
+		return int32(v), nil
+
 	default:
 		socket.GetSockOptEmitUnimplementedEvent(t, name)
 	}

pkg/tcpip/tcpip.go

@@ -497,6 +497,10 @@ type AddMembershipOption MembershipOption
 // the given interface address.
 type RemoveMembershipOption MembershipOption
 
+// OutOfBandInlineOption is used by SetSockOpt/GetSockOpt to specify whether
+// TCP out-of-band data is delivered along with the normal in-band data.
+type OutOfBandInlineOption int
+
 // Route is a row in the routing table. It specifies through which NIC (and
 // gateway) sets of packets should be routed. A row is considered viable if the
 // masked target address matches the destination adddress in the row.

pkg/tcpip/transport/tcp/endpoint.go

@@ -940,6 +940,11 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 		e.keepalive.Unlock()
 		return nil
 
+	case *tcpip.OutOfBandInlineOption:
+		// We don't currently support disabling this option.
+		*o = 1
+		return nil
+
 	default:
 		return tcpip.ErrUnknownProtocolOption
 	}

test/syscalls/linux/socket_ip_tcp_generic.cc

@@ -522,5 +522,21 @@ TEST_P(TCPSocketPairTest, SetTCPKeepintvlToMax) {
   EXPECT_EQ(get, MAX_TCP_KEEPINTVL);
 }
 
+TEST_P(TCPSocketPairTest, SetOOBInline) {
+  auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
+
+  EXPECT_THAT(setsockopt(sockets->first_fd(), SOL_SOCKET, SO_OOBINLINE,
+                         &kSockOptOn, sizeof(kSockOptOn)),
+              SyscallSucceeds());
+
+  int get = -1;
+  socklen_t get_len = sizeof(get);
+  EXPECT_THAT(
+      getsockopt(sockets->first_fd(), SOL_SOCKET, SO_OOBINLINE, &get, &get_len),
+      SyscallSucceedsWithValue(0));
+  EXPECT_EQ(get_len, sizeof(get));
+  EXPECT_EQ(get, kSockOptOn);
+}
+
 }  // namespace testing
 }  // namespace gvisor