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// Copyright 2019 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 ipv6
import (
"strings"
"testing"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
)
// setupStackAndEndpoint creates a stack with a single NIC with a link-local
// address llladdr and an IPv6 endpoint to a remote with link-local address
// rlladdr
func setupStackAndEndpoint(t *testing.T, llladdr, rlladdr tcpip.Address) (*stack.Stack, stack.NetworkEndpoint) {
t.Helper()
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocol{NewProtocol()},
TransportProtocols: []stack.TransportProtocol{icmp.NewProtocol6()},
})
if err := s.CreateNIC(1, &stubLinkEndpoint{}); err != nil {
t.Fatalf("CreateNIC(_) = %s", err)
}
if err := s.AddAddress(1, ProtocolNumber, llladdr); err != nil {
t.Fatalf("AddAddress(_, %d, %s) = %s", ProtocolNumber, llladdr, err)
}
{
subnet, err := tcpip.NewSubnet(rlladdr, tcpip.AddressMask(strings.Repeat("\xff", len(rlladdr))))
if err != nil {
t.Fatal(err)
}
s.SetRouteTable(
[]tcpip.Route{{
Destination: subnet,
NIC: 1,
}},
)
}
netProto := s.NetworkProtocolInstance(ProtocolNumber)
if netProto == nil {
t.Fatalf("cannot find protocol instance for network protocol %d", ProtocolNumber)
}
ep, err := netProto.NewEndpoint(0, tcpip.AddressWithPrefix{rlladdr, netProto.DefaultPrefixLen()}, &stubLinkAddressCache{}, &stubDispatcher{}, nil)
if err != nil {
t.Fatalf("NewEndpoint(_) = _, %s, want = _, nil", err)
}
return s, ep
}
// TestHopLimitValidation is a test that makes sure that NDP packets are only
// received if their IP header's hop limit is set to 255.
func TestHopLimitValidation(t *testing.T) {
setup := func(t *testing.T) (*stack.Stack, stack.NetworkEndpoint, stack.Route) {
t.Helper()
// Create a stack with the assigned link-local address lladdr0
// and an endpoint to lladdr1.
s, ep := setupStackAndEndpoint(t, lladdr0, lladdr1)
r, err := s.FindRoute(1, lladdr0, lladdr1, ProtocolNumber, false /* multicastLoop */)
if err != nil {
t.Fatalf("FindRoute(_) = _, %s, want = _, nil", err)
}
return s, ep, r
}
handleIPv6Payload := func(hdr buffer.Prependable, hopLimit uint8, ep stack.NetworkEndpoint, r *stack.Route) {
payloadLength := hdr.UsedLength()
ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
ip.Encode(&header.IPv6Fields{
PayloadLength: uint16(payloadLength),
NextHeader: uint8(header.ICMPv6ProtocolNumber),
HopLimit: hopLimit,
SrcAddr: r.LocalAddress,
DstAddr: r.RemoteAddress,
})
ep.HandlePacket(r, hdr.View().ToVectorisedView())
}
types := []struct {
name string
typ header.ICMPv6Type
size int
statCounter func(tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter
}{
{"RouterSolicit", header.ICMPv6RouterSolicit, header.ICMPv6MinimumSize, func(stats tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter {
return stats.RouterSolicit
}},
{"RouterAdvert", header.ICMPv6RouterAdvert, header.ICMPv6MinimumSize, func(stats tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter {
return stats.RouterAdvert
}},
{"NeighborSolicit", header.ICMPv6NeighborSolicit, header.ICMPv6NeighborSolicitMinimumSize, func(stats tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter {
return stats.NeighborSolicit
}},
{"NeighborAdvert", header.ICMPv6NeighborAdvert, header.ICMPv6NeighborAdvertSize, func(stats tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter {
return stats.NeighborAdvert
}},
{"RedirectMsg", header.ICMPv6RedirectMsg, header.ICMPv6MinimumSize, func(stats tcpip.ICMPv6ReceivedPacketStats) *tcpip.StatCounter {
return stats.RedirectMsg
}},
}
for _, typ := range types {
t.Run(typ.name, func(t *testing.T) {
s, ep, r := setup(t)
defer r.Release()
stats := s.Stats().ICMP.V6PacketsReceived
invalid := stats.Invalid
typStat := typ.statCounter(stats)
hdr := buffer.NewPrependable(header.IPv6MinimumSize + typ.size)
pkt := header.ICMPv6(hdr.Prepend(typ.size))
pkt.SetType(typ.typ)
pkt.SetChecksum(header.ICMPv6Checksum(pkt, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{}))
// Invalid count should initially be 0.
if got := invalid.Value(); got != 0 {
t.Fatalf("got invalid = %d, want = 0", got)
}
// Should not have received any ICMPv6 packets with
// type = typ.typ.
if got := typStat.Value(); got != 0 {
t.Fatalf("got %s = %d, want = 0", typ.name, got)
}
// Receive the NDP packet with an invalid hop limit
// value.
handleIPv6Payload(hdr, ndpHopLimit-1, ep, &r)
// Invalid count should have increased.
if got := invalid.Value(); got != 1 {
t.Fatalf("got invalid = %d, want = 1", got)
}
// Rx count of NDP packet of type typ.typ should not
// have increased.
if got := typStat.Value(); got != 0 {
t.Fatalf("got %s = %d, want = 0", typ.name, got)
}
// Receive the NDP packet with a valid hop limit value.
handleIPv6Payload(hdr, ndpHopLimit, ep, &r)
// Rx count of NDP packet of type typ.typ should have
// increased.
if got := typStat.Value(); got != 1 {
t.Fatalf("got %s = %d, want = 1", typ.name, got)
}
// Invalid count should not have increased again.
if got := invalid.Value(); got != 1 {
t.Fatalf("got invalid = %d, want = 1", got)
}
})
}
}
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