@ -5,6 +5,7 @@ package checksum
import (
"encoding/binary"
"math/rand/v2"
"net/netip"
"testing"
@ -94,7 +95,7 @@ func TestHeaderChecksumsV4(t *testing.T) {
}
func TestNatChecksumsV6UDP ( t * testing . T ) {
a1 , a2 := netip . MustParseAddr ( "a::1" ) , netip . MustParseAddr ( "b::1" )
a1 , a2 := randV6Addr ( ) , randV6Addr ( )
// Make a fake UDP packet with 32 bytes of zeros as the datagram payload.
b := header . IPv6 ( make ( [ ] byte , header . IPv6MinimumSize + header . UDPMinimumSize + 32 ) )
@ -124,25 +125,43 @@ func TestNatChecksumsV6UDP(t *testing.T) {
}
// Parse the packet.
var p packet . Parsed
var p , p2 packet . Parsed
p . Decode ( b )
t . Log ( p . String ( ) )
// Update the source address of the packet to be the same as the dest.
UpdateSrcAddr ( & p , a2 )
p2 . Decode ( p . Buffer ( ) )
if p2 . Src . Addr ( ) != a2 {
t . Fatalf ( "got %v, want %v" , p2 . Src , a2 )
}
if ! udp . IsChecksumValid ( tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , checksum . Checksum ( b . Payload ( ) [ header . UDPMinimumSize : ] , 0 ) ) {
t . Fatal ( "incorrect checksum after updating source address" )
}
// Update the dest address of the packet to be the original source address.
UpdateDstAddr ( & p , a1 )
p2 . Decode ( p . Buffer ( ) )
if p2 . Dst . Addr ( ) != a1 {
t . Fatalf ( "got %v, want %v" , p2 . Dst , a1 )
}
if ! udp . IsChecksumValid ( tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , tcpip . AddrFrom16Slice ( a1 . AsSlice ( ) ) , checksum . Checksum ( b . Payload ( ) [ header . UDPMinimumSize : ] , 0 ) ) {
t . Fatal ( "incorrect checksum after updating destination address" )
}
}
func randV6Addr ( ) netip . Addr {
a1 , a2 := rand . Int64 ( ) , rand . Int64 ( )
return netip . AddrFrom16 ( [ 16 ] byte {
byte ( a1 >> 56 ) , byte ( a1 >> 48 ) , byte ( a1 >> 40 ) , byte ( a1 >> 32 ) ,
byte ( a1 >> 24 ) , byte ( a1 >> 16 ) , byte ( a1 >> 8 ) , byte ( a1 ) ,
byte ( a2 >> 56 ) , byte ( a2 >> 48 ) , byte ( a2 >> 40 ) , byte ( a2 >> 32 ) ,
byte ( a2 >> 24 ) , byte ( a2 >> 16 ) , byte ( a2 >> 8 ) , byte ( a2 ) ,
} )
}
func TestNatChecksumsV6TCP ( t * testing . T ) {
a1 , a2 := netip . MustParseAddr ( "a::1" ) , netip . MustParseAddr ( "b::1" )
a1 , a2 := randV6Addr ( ) , randV6Addr ( )
// Make a fake TCP packet with no payload.
b := header . IPv6 ( make ( [ ] byte , header . IPv6MinimumSize + header . TCPMinimumSize ) )
@ -178,18 +197,26 @@ func TestNatChecksumsV6TCP(t *testing.T) {
}
// Parse the packet.
var p packet . Parsed
var p , p2 packet . Parsed
p . Decode ( b )
t . Log ( p . String ( ) )
// Update the source address of the packet to be the same as the dest.
UpdateSrcAddr ( & p , a2 )
p2 . Decode ( p . Buffer ( ) )
if p2 . Src . Addr ( ) != a2 {
t . Fatalf ( "got %v, want %v" , p2 . Src , a2 )
}
if ! tcp . IsChecksumValid ( tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , 0 , 0 ) {
t . Fatal ( "incorrect checksum after updating source address" )
}
// Update the dest address of the packet to be the original source address.
UpdateDstAddr ( & p , a1 )
p2 . Decode ( p . Buffer ( ) )
if p2 . Dst . Addr ( ) != a1 {
t . Fatalf ( "got %v, want %v" , p2 . Dst , a1 )
}
if ! tcp . IsChecksumValid ( tcpip . AddrFrom16Slice ( a2 . AsSlice ( ) ) , tcpip . AddrFrom16Slice ( a1 . AsSlice ( ) ) , 0 , 0 ) {
t . Fatal ( "incorrect checksum after updating destination address" )
}