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// Copyright 2018 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 arp_test
import (
"strconv"
"testing"
"time"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
"gvisor.dev/gvisor/pkg/tcpip/link/sniffer"
"gvisor.dev/gvisor/pkg/tcpip/network/arp"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
)
const (
stackLinkAddr = tcpip.LinkAddress("\x0a\x0a\x0b\x0b\x0c\x0c")
stackAddr1 = tcpip.Address("\x0a\x00\x00\x01")
stackAddr2 = tcpip.Address("\x0a\x00\x00\x02")
stackAddrBad = tcpip.Address("\x0a\x00\x00\x03")
)
type testContext struct {
t *testing.T
linkEP *channel.Endpoint
s *stack.Stack
}
func newTestContext(t *testing.T) *testContext {
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), arp.NewProtocol()},
TransportProtocols: []stack.TransportProtocol{icmp.NewProtocol4()},
})
const defaultMTU = 65536
ep := channel.New(256, defaultMTU, stackLinkAddr)
wep := stack.LinkEndpoint(ep)
if testing.Verbose() {
wep = sniffer.New(ep)
}
if err := s.CreateNIC(1, wep); err != nil {
t.Fatalf("CreateNIC failed: %v", err)
}
if err := s.AddAddress(1, ipv4.ProtocolNumber, stackAddr1); err != nil {
t.Fatalf("AddAddress for ipv4 failed: %v", err)
}
if err := s.AddAddress(1, ipv4.ProtocolNumber, stackAddr2); err != nil {
t.Fatalf("AddAddress for ipv4 failed: %v", err)
}
if err := s.AddAddress(1, arp.ProtocolNumber, arp.ProtocolAddress); err != nil {
t.Fatalf("AddAddress for arp failed: %v", err)
}
s.SetRouteTable([]tcpip.Route{{
Destination: header.IPv4EmptySubnet,
NIC: 1,
}})
return &testContext{
t: t,
s: s,
linkEP: ep,
}
}
func (c *testContext) cleanup() {
close(c.linkEP.C)
}
func TestDirectRequest(t *testing.T) {
c := newTestContext(t)
defer c.cleanup()
const senderMAC = "\x01\x02\x03\x04\x05\x06"
const senderIPv4 = "\x0a\x00\x00\x02"
v := make(buffer.View, header.ARPSize)
h := header.ARP(v)
h.SetIPv4OverEthernet()
h.SetOp(header.ARPRequest)
copy(h.HardwareAddressSender(), senderMAC)
copy(h.ProtocolAddressSender(), senderIPv4)
inject := func(addr tcpip.Address) {
copy(h.ProtocolAddressTarget(), addr)
c.linkEP.InjectInbound(arp.ProtocolNumber, tcpip.PacketBuffer{
Data: v.ToVectorisedView(),
})
}
for i, address := range []tcpip.Address{stackAddr1, stackAddr2} {
t.Run(strconv.Itoa(i), func(t *testing.T) {
inject(address)
pi := <-c.linkEP.C
if pi.Proto != arp.ProtocolNumber {
t.Fatalf("expected ARP response, got network protocol number %d", pi.Proto)
}
rep := header.ARP(pi.Pkt.Header.View())
if !rep.IsValid() {
t.Fatalf("invalid ARP response pi.Pkt.Header.UsedLength()=%d", pi.Pkt.Header.UsedLength())
}
if got, want := tcpip.LinkAddress(rep.HardwareAddressSender()), stackLinkAddr; got != want {
t.Errorf("got HardwareAddressSender = %s, want = %s", got, want)
}
if got, want := tcpip.Address(rep.ProtocolAddressSender()), tcpip.Address(h.ProtocolAddressTarget()); got != want {
t.Errorf("got ProtocolAddressSender = %s, want = %s", got, want)
}
if got, want := tcpip.LinkAddress(rep.HardwareAddressTarget()), tcpip.LinkAddress(h.HardwareAddressSender()); got != want {
t.Errorf("got HardwareAddressTarget = %s, want = %s", got, want)
}
if got, want := tcpip.Address(rep.ProtocolAddressTarget()), tcpip.Address(h.ProtocolAddressSender()); got != want {
t.Errorf("got ProtocolAddressTarget = %s, want = %s", got, want)
}
})
}
inject(stackAddrBad)
select {
case pkt := <-c.linkEP.C:
t.Errorf("stackAddrBad: unexpected packet sent, Proto=%v", pkt.Proto)
case <-time.After(100 * time.Millisecond):
// Sleep tests are gross, but this will only potentially flake
// if there's a bug. If there is no bug this will reliably
// succeed.
}
}
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