cloudflared-mirror/ingress/origin_icmp_proxy_test.go

328 lines
7.7 KiB
Go

package ingress
import (
"context"
"fmt"
"net"
"net/netip"
"strings"
"sync"
"testing"
"github.com/google/gopacket/layers"
"github.com/rs/zerolog"
"github.com/stretchr/testify/require"
"golang.org/x/net/icmp"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"github.com/cloudflare/cloudflared/packet"
)
var (
noopLogger = zerolog.Nop()
localhostIP = netip.MustParseAddr("127.0.0.1")
localhostIPv6 = netip.MustParseAddr("::1")
)
// TestICMPProxyEcho makes sure we can send ICMP echo via the Request method and receives response via the
// ListenResponse method
//
// Note: if this test fails on your device under Linux, then most likely you need to make sure that your user
// is allowed in ping_group_range. See the following gist for how to do that:
// https://github.com/ValentinBELYN/icmplib/blob/main/docs/6-use-icmplib-without-privileges.md
func TestICMPRouterEcho(t *testing.T) {
testICMPRouterEcho(t, true)
testICMPRouterEcho(t, false)
}
func testICMPRouterEcho(t *testing.T, sendIPv4 bool) {
const (
echoID = 36571
endSeq = 20
)
router, err := NewICMPRouter(&noopLogger)
require.NoError(t, err)
proxyDone := make(chan struct{})
ctx, cancel := context.WithCancel(context.Background())
go func() {
router.Serve(ctx)
close(proxyDone)
}()
responder := echoFlowResponder{
decoder: packet.NewICMPDecoder(),
respChan: make(chan []byte, 1),
}
protocol := layers.IPProtocolICMPv6
if sendIPv4 {
protocol = layers.IPProtocolICMPv4
}
localIPs := getLocalIPs(t, sendIPv4)
ips := make([]*packet.IP, len(localIPs))
for i, localIP := range localIPs {
ips[i] = &packet.IP{
Src: localIP,
Dst: localIP,
Protocol: protocol,
TTL: packet.DefaultTTL,
}
}
var icmpType icmp.Type = ipv6.ICMPTypeEchoRequest
if sendIPv4 {
icmpType = ipv4.ICMPTypeEcho
}
for seq := 0; seq < endSeq; seq++ {
for i, ip := range ips {
pk := packet.ICMP{
IP: ip,
Message: &icmp.Message{
Type: icmpType,
Code: 0,
Body: &icmp.Echo{
ID: echoID + i,
Seq: seq,
Data: []byte(fmt.Sprintf("icmp echo seq %d", seq)),
},
},
}
require.NoError(t, router.Request(&pk, &responder))
responder.validate(t, &pk)
}
}
cancel()
<-proxyDone
}
// TestConcurrentRequests makes sure icmpRouter can send concurrent requests to the same destination with different
// echo ID. This simulates concurrent ping to the same destination.
func TestConcurrentRequestsToSameDst(t *testing.T) {
const (
concurrentPings = 5
endSeq = 5
)
router, err := NewICMPRouter(&noopLogger)
require.NoError(t, err)
proxyDone := make(chan struct{})
ctx, cancel := context.WithCancel(context.Background())
go func() {
router.Serve(ctx)
close(proxyDone)
}()
var wg sync.WaitGroup
// icmpv4 and icmpv6 each has concurrentPings
wg.Add(concurrentPings * 2)
for i := 0; i < concurrentPings; i++ {
echoID := 38451 + i
go func() {
defer wg.Done()
responder := echoFlowResponder{
decoder: packet.NewICMPDecoder(),
respChan: make(chan []byte, 1),
}
for seq := 0; seq < endSeq; seq++ {
pk := &packet.ICMP{
IP: &packet.IP{
Src: localhostIP,
Dst: localhostIP,
Protocol: layers.IPProtocolICMPv4,
TTL: packet.DefaultTTL,
},
Message: &icmp.Message{
Type: ipv4.ICMPTypeEcho,
Code: 0,
Body: &icmp.Echo{
ID: echoID,
Seq: seq,
Data: []byte(fmt.Sprintf("icmpv4 echo id %d, seq %d", echoID, seq)),
},
},
}
require.NoError(t, router.Request(pk, &responder))
responder.validate(t, pk)
}
}()
go func() {
defer wg.Done()
responder := echoFlowResponder{
decoder: packet.NewICMPDecoder(),
respChan: make(chan []byte, 1),
}
for seq := 0; seq < endSeq; seq++ {
pk := &packet.ICMP{
IP: &packet.IP{
Src: localhostIPv6,
Dst: localhostIPv6,
Protocol: layers.IPProtocolICMPv6,
TTL: packet.DefaultTTL,
},
Message: &icmp.Message{
Type: ipv6.ICMPTypeEchoRequest,
Code: 0,
Body: &icmp.Echo{
ID: echoID,
Seq: seq,
Data: []byte(fmt.Sprintf("icmpv6 echo id %d, seq %d", echoID, seq)),
},
},
}
require.NoError(t, router.Request(pk, &responder))
responder.validate(t, pk)
}
}()
}
wg.Wait()
cancel()
<-proxyDone
}
// TestICMPProxyRejectNotEcho makes sure it rejects messages other than echo
func TestICMPRouterRejectNotEcho(t *testing.T) {
msgs := []icmp.Message{
{
Type: ipv4.ICMPTypeDestinationUnreachable,
Code: 1,
Body: &icmp.DstUnreach{
Data: []byte("original packet"),
},
},
{
Type: ipv4.ICMPTypeTimeExceeded,
Code: 1,
Body: &icmp.TimeExceeded{
Data: []byte("original packet"),
},
},
{
Type: ipv4.ICMPType(2),
Code: 0,
Body: &icmp.PacketTooBig{
MTU: 1280,
Data: []byte("original packet"),
},
},
}
testICMPRouterRejectNotEcho(t, localhostIP, msgs)
msgsV6 := []icmp.Message{
{
Type: ipv6.ICMPTypeDestinationUnreachable,
Code: 3,
Body: &icmp.DstUnreach{
Data: []byte("original packet"),
},
},
{
Type: ipv6.ICMPTypeTimeExceeded,
Code: 0,
Body: &icmp.TimeExceeded{
Data: []byte("original packet"),
},
},
{
Type: ipv6.ICMPTypePacketTooBig,
Code: 0,
Body: &icmp.PacketTooBig{
MTU: 1280,
Data: []byte("original packet"),
},
},
}
testICMPRouterRejectNotEcho(t, localhostIPv6, msgsV6)
}
func testICMPRouterRejectNotEcho(t *testing.T, srcDstIP netip.Addr, msgs []icmp.Message) {
router, err := NewICMPRouter(&noopLogger)
require.NoError(t, err)
responder := echoFlowResponder{
decoder: packet.NewICMPDecoder(),
respChan: make(chan []byte),
}
protocol := layers.IPProtocolICMPv4
if srcDstIP.Is6() {
protocol = layers.IPProtocolICMPv6
}
for _, m := range msgs {
pk := packet.ICMP{
IP: &packet.IP{
Src: srcDstIP,
Dst: srcDstIP,
Protocol: protocol,
TTL: packet.DefaultTTL,
},
Message: &m,
}
require.Error(t, router.Request(&pk, &responder))
}
}
type echoFlowResponder struct {
decoder *packet.ICMPDecoder
respChan chan []byte
}
func (efr *echoFlowResponder) SendPacket(dst netip.Addr, pk packet.RawPacket) error {
copiedPacket := make([]byte, len(pk.Data))
copy(copiedPacket, pk.Data)
efr.respChan <- copiedPacket
return nil
}
func (efr *echoFlowResponder) Close() error {
close(efr.respChan)
return nil
}
func (efr *echoFlowResponder) validate(t *testing.T, echoReq *packet.ICMP) {
pk := <-efr.respChan
decoded, err := efr.decoder.Decode(packet.RawPacket{Data: pk})
require.NoError(t, err)
require.Equal(t, decoded.Src, echoReq.Dst)
require.Equal(t, decoded.Dst, echoReq.Src)
require.Equal(t, echoReq.Protocol, decoded.Protocol)
if echoReq.Type == ipv4.ICMPTypeEcho {
require.Equal(t, ipv4.ICMPTypeEchoReply, decoded.Type)
} else {
require.Equal(t, ipv6.ICMPTypeEchoReply, decoded.Type)
}
require.Equal(t, 0, decoded.Code)
if echoReq.Type == ipv4.ICMPTypeEcho {
require.NotZero(t, decoded.Checksum)
} else {
// For ICMPv6, the kernel will compute the checksum during transmission unless pseudo header is not nil
require.Zero(t, decoded.Checksum)
}
require.Equal(t, echoReq.Body, decoded.Body)
}
func getLocalIPs(t *testing.T, ipv4 bool) []netip.Addr {
interfaces, err := net.Interfaces()
require.NoError(t, err)
localIPs := []netip.Addr{}
for _, i := range interfaces {
// Skip TUN devices
if strings.Contains(i.Name, "tun") {
continue
}
addrs, err := i.Addrs()
require.NoError(t, err)
for _, addr := range addrs {
if ipnet, ok := addr.(*net.IPNet); ok && (ipnet.IP.IsPrivate() || ipnet.IP.IsLoopback()) {
if (ipv4 && ipnet.IP.To4() != nil) || (!ipv4 && ipnet.IP.To4() == nil) {
localIPs = append(localIPs, netip.MustParseAddr(ipnet.IP.String()))
}
}
}
}
return localIPs
}