@ -21,6 +21,11 @@ import (
"tailscale.com/util/must"
)
const (
ethType4 = layers . EthernetTypeIPv4
ethType6 = layers . EthernetTypeIPv6
)
// TestPacketSideEffects tests that upon receiving certain
// packets, other packets and/or log statements are generated.
func TestPacketSideEffects ( t * testing . T ) {
@ -36,7 +41,7 @@ func TestPacketSideEffects(t *testing.T) {
} {
{
netName : "basic" ,
setup : newTwoNodesSameNetwork Server ,
setup : newTwoNodesSameNetwork ,
tests : [ ] netTest {
{
name : "drop-rando-ethertype" ,
@ -63,6 +68,37 @@ func TestPacketSideEffects(t *testing.T) {
pktSubstr ( "Unable to decode EthernetType 4660" ) ,
) ,
} ,
{
name : "dns-request-v4" ,
pkt : mkDNSReq ( 4 ) ,
check : all (
numPkts ( 1 ) ,
pktSubstr ( "Data=[52, 52, 0, 3] IP=52.52.0.3" ) ,
) ,
} ,
{
name : "dns-request-v6" ,
pkt : mkDNSReq ( 6 ) ,
check : all (
numPkts ( 1 ) ,
pktSubstr ( " IP=2052::3 " ) ,
) ,
} ,
} ,
} ,
{
netName : "v4" ,
setup : newTwoNodesSameV4Network ,
tests : [ ] netTest {
{
name : "no-v6-reply-on-v4-only" ,
pkt : mkIPv6RouterSolicit ( nodeMac ( 1 ) , nodeLANIP6 ( 1 ) ) ,
check : all (
numPkts ( 0 ) ,
logSubstr ( "dropping IPv6 packet on v4-only network" ) ,
) ,
} ,
// TODO(bradfitz): DHCP request + response
} ,
} ,
{
@ -170,16 +206,7 @@ func mkIPv6RouterSolicit(srcMAC MAC, srcIP netip.Addr) []byte {
} } ,
}
icmp . SetNetworkLayerForChecksum ( ip )
return mkEth ( macAllRouters , srcMAC , layers . EthernetTypeIPv6 , mkPacket ( ip , icmp , ra ) )
}
func mkPacket ( layers ... gopacket . SerializableLayer ) [ ] byte {
buf := gopacket . NewSerializeBuffer ( )
opts := gopacket . SerializeOptions { FixLengths : true , ComputeChecksums : true }
if err := gopacket . SerializeLayers ( buf , opts , layers ... ) ; err != nil {
panic ( fmt . Sprintf ( "serializing packet: %v" , err ) )
}
return buf . Bytes ( )
return mkEth ( macAllRouters , srcMAC , ethType6 , mkPacket ( ip , icmp , ra ) )
}
func mkAllNodesPing ( srcMAC MAC , srcIP netip . Addr ) [ ] byte {
@ -194,7 +221,68 @@ func mkAllNodesPing(srcMAC MAC, srcIP netip.Addr) []byte {
TypeCode : layers . CreateICMPv6TypeCode ( layers . ICMPv6TypeEchoRequest , 0 ) ,
}
icmp . SetNetworkLayerForChecksum ( ip )
return mkEth ( macAllNodes , srcMAC , layers . EthernetTypeIPv6 , mkPacket ( ip , icmp ) )
return mkEth ( macAllNodes , srcMAC , ethType6 , mkPacket ( ip , icmp ) )
}
// mkDNSReq makes a DNS request to "control.tailscale" using the source IPs as
// defined in this test file.
//
// ipVer must be 4 or 6:
// If 4, it makes an A record request.
// If 6, it makes a AAAA record request.
//
// (Yes, this is technically unrelated (you can request A records over IPv6 or
// AAAA records over IPv4), but for test coverage reasons, assume that the ipVer
// of 6 means to also request an AAAA record.)
func mkDNSReq ( ipVer int ) [ ] byte {
eth := & layers . Ethernet {
SrcMAC : nodeMac ( 1 ) . HWAddr ( ) ,
DstMAC : routerMac ( 1 ) . HWAddr ( ) ,
EthernetType : layers . EthernetTypeIPv4 ,
}
if ipVer == 6 {
eth . EthernetType = layers . EthernetTypeIPv6
}
var ip serializableNetworkLayer
switch ipVer {
case 4 :
ip = & layers . IPv4 {
Version : 4 ,
Protocol : layers . IPProtocolUDP ,
SrcIP : net . ParseIP ( "192.168.0.101" ) ,
TTL : 64 ,
DstIP : FakeDNSIPv4 ( ) . AsSlice ( ) ,
}
case 6 :
ip = & layers . IPv6 {
Version : 6 ,
HopLimit : 64 ,
NextHeader : layers . IPProtocolUDP ,
SrcIP : net . ParseIP ( "2000:52::1" ) ,
DstIP : FakeDNSIPv6 ( ) . AsSlice ( ) ,
}
default :
panic ( "bad ipVer" )
}
udp := & layers . UDP {
SrcPort : 12345 ,
DstPort : 53 ,
}
udp . SetNetworkLayerForChecksum ( ip )
dns := & layers . DNS {
ID : 789 ,
Questions : [ ] layers . DNSQuestion { {
Name : [ ] byte ( "control.tailscale" ) ,
Type : layers . DNSTypeA ,
Class : layers . DNSClassIN ,
} } ,
}
if ipVer == 6 {
dns . Questions [ 0 ] . Type = layers . DNSTypeAAAA
}
return mkPacket ( eth , ip , udp , dns )
}
// sideEffects gathers side effects as a result of sending a packet and tests
@ -269,7 +357,15 @@ func numPkts(want int) func(*sideEffects) error {
}
}
func newTwoNodesSameNetworkServer ( ) ( * Server , error ) {
func newTwoNodesSameNetwork ( ) ( * Server , error ) {
var c Config
nw := c . AddNetwork ( "192.168.0.1/24" , "2052::1/64" )
c . AddNode ( nw )
c . AddNode ( nw )
return New ( & c )
}
func newTwoNodesSameV4Network ( ) ( * Server , error ) {
var c Config
nw := c . AddNetwork ( "192.168.0.1/24" )
c . AddNode ( nw )
@ -286,7 +382,7 @@ func TestProtocolQEMU(t *testing.T) {
if runtime . GOOS == "windows" {
t . Skipf ( "skipping on %s" , runtime . GOOS )
}
s := must . Get ( newTwoNodesSameNetwork Server ( ) )
s := must . Get ( newTwoNodesSameNetwork ( ) )
defer s . Close ( )
s . SetLoggerForTest ( t . Logf )
@ -329,7 +425,7 @@ func TestProtocolUnixDgram(t *testing.T) {
if runtime . GOOS == "windows" {
t . Skipf ( "skipping on %s" , runtime . GOOS )
}
s := must . Get ( newTwoNodesSameNetwork Server ( ) )
s := must . Get ( newTwoNodesSameNetwork ( ) )
defer s . Close ( )
s . SetLoggerForTest ( t . Logf )