Test UDP packets with mcast source addr are discarded

PiperOrigin-RevId: 321790802

test/packetimpact/tests/BUILD

@@ -26,6 +26,17 @@ packetimpact_go_test(
     ],
 )
 
+packetimpact_go_test(
+    name = "udp_discard_mcast_source_addr",
+    srcs = ["udp_discard_mcast_source_addr_test.go"],
+    deps = [
+        "//pkg/tcpip",
+        "//pkg/tcpip/header",
+        "//test/packetimpact/testbench",
+        "@org_golang_x_sys//unix:go_default_library",
+    ],
+)
+
 packetimpact_go_test(
     name = "udp_recv_mcast_bcast",
     srcs = ["udp_recv_mcast_bcast_test.go"],

test/packetimpact/tests/udp_discard_mcast_source_addr_test.go

@@ -0,0 +1,92 @@
+// 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 udp_discard_mcast_source_addr_test
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"net"
+	"syscall"
+	"testing"
+
+	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/test/packetimpact/testbench"
+)
+
+var oneSecond = unix.Timeval{Sec: 1, Usec: 0}
+
+func init() {
+	testbench.RegisterFlags(flag.CommandLine)
+}
+
+func TestDiscardsUDPPacketsWithMcastSourceAddressV4(t *testing.T) {
+	dut := testbench.NewDUT(t)
+	defer dut.TearDown()
+	remoteFD, remotePort := dut.CreateBoundSocket(unix.SOCK_DGRAM, unix.IPPROTO_UDP, net.ParseIP(testbench.RemoteIPv4))
+	defer dut.Close(remoteFD)
+	dut.SetSockOptTimeval(remoteFD, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &oneSecond)
+	conn := testbench.NewUDPIPv4(t, testbench.UDP{DstPort: &remotePort}, testbench.UDP{SrcPort: &remotePort})
+	defer conn.Close()
+
+	for _, mcastAddr := range []net.IP{
+		net.IPv4allsys,
+		net.IPv4allrouter,
+		net.IPv4(224, 0, 1, 42),
+		net.IPv4(232, 1, 2, 3),
+	} {
+		t.Run(fmt.Sprintf("srcaddr=%s", mcastAddr), func(t *testing.T) {
+			conn.SendIP(
+				testbench.IPv4{SrcAddr: testbench.Address(tcpip.Address(mcastAddr.To4()))},
+				testbench.UDP{},
+			)
+
+			ret, payload, errno := dut.RecvWithErrno(context.Background(), remoteFD, 100, 0)
+			if errno != syscall.EAGAIN || errno != syscall.EWOULDBLOCK {
+				t.Errorf("Recv got unexpected result, ret=%d, payload=%q, errno=%s", ret, payload, errno)
+			}
+		})
+	}
+}
+
+func TestDiscardsUDPPacketsWithMcastSourceAddressV6(t *testing.T) {
+	dut := testbench.NewDUT(t)
+	defer dut.TearDown()
+	remoteFD, remotePort := dut.CreateBoundSocket(unix.SOCK_DGRAM, unix.IPPROTO_UDP, net.ParseIP(testbench.RemoteIPv6))
+	defer dut.Close(remoteFD)
+	dut.SetSockOptTimeval(remoteFD, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &oneSecond)
+	conn := testbench.NewUDPIPv6(t, testbench.UDP{DstPort: &remotePort}, testbench.UDP{SrcPort: &remotePort})
+	defer conn.Close()
+
+	for _, mcastAddr := range []net.IP{
+		net.IPv6interfacelocalallnodes,
+		net.IPv6linklocalallnodes,
+		net.IPv6linklocalallrouters,
+		net.ParseIP("fe01::42"),
+		net.ParseIP("fe02::4242"),
+	} {
+		t.Run(fmt.Sprintf("srcaddr=%s", mcastAddr), func(t *testing.T) {
+			conn.SendIPv6(
+				testbench.IPv6{SrcAddr: testbench.Address(tcpip.Address(mcastAddr.To16()))},
+				testbench.UDP{},
+			)
+			ret, payload, errno := dut.RecvWithErrno(context.Background(), remoteFD, 100, 0)
+			if errno != syscall.EAGAIN || errno != syscall.EWOULDBLOCK {
+				t.Errorf("Recv got unexpected result, ret=%d, payload=%q, errno=%s", ret, payload, errno)
+			}
+		})
+	}
+}