// 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_recv_mcast_bcast_test

import (
	"flag"
	"net"
	"testing"

	"golang.org/x/sys/unix"
	"gvisor.dev/gvisor/pkg/tcpip"
	"gvisor.dev/gvisor/test/packetimpact/testbench"
)

func init() {
	testbench.RegisterFlags(flag.CommandLine)
}

func TestUDPRecvMulticastBroadcast(t *testing.T) {
	dut := testbench.NewDUT(t)
	defer dut.TearDown()
	boundFD, remotePort := dut.CreateBoundSocket(unix.SOCK_DGRAM, unix.IPPROTO_UDP, net.IPv4(0, 0, 0, 0))
	defer dut.Close(boundFD)
	conn := testbench.NewUDPIPv4(t, testbench.UDP{DstPort: &remotePort}, testbench.UDP{SrcPort: &remotePort})
	defer conn.Close()

	for _, bcastAddr := range []net.IP{
		broadcastAddr(net.ParseIP(testbench.RemoteIPv4), net.CIDRMask(testbench.IPv4PrefixLength, 32)),
		net.IPv4(255, 255, 255, 255),
		net.IPv4(224, 0, 0, 1),
	} {
		payload := testbench.GenerateRandomPayload(t, 1<<10)
		conn.SendIP(
			testbench.IPv4{DstAddr: testbench.Address(tcpip.Address(bcastAddr.To4()))},
			testbench.UDP{},
			&testbench.Payload{Bytes: payload},
		)
		t.Logf("Receiving packet sent to address: %s", bcastAddr)
		if got, want := string(dut.Recv(boundFD, int32(len(payload)), 0)), string(payload); got != want {
			t.Errorf("received payload does not match sent payload got: %s, want: %s", got, want)
		}
	}
}

func broadcastAddr(ip net.IP, mask net.IPMask) net.IP {
	ip4 := ip.To4()
	for i := range ip4 {
		ip4[i] |= ^mask[i]
	}
	return ip4
}