diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-07-27 17:23:30 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-07-27 17:34:35 +0200 |
| commit | 93c824172a975ed03c66649c3513f446a9ff07b2 (patch) | |
| tree | e1810ddeff1dafa277cfe9d7a623e6890ef2a3a2 /tests/py/inet/tcp.t.payload | |
| parent | be9bd9cc7288477e54bef0225321ffa72b409116 (diff) | |
netlink_linearize: incorrect netlink bytecode with binary operation and flags
nft generates incorrect bytecode when combining flag datatype and binary
operations:
# nft --debug=netlink add rule meh tcp_flags 'tcp flags & (fin | syn | rst | ack) syn'
ip
[ meta load l4proto => reg 1 ]
[ cmp eq reg 1 0x00000006 ]
[ payload load 1b @ transport header + 13 => reg 1 ]
[ bitwise reg 1 = ( reg 1 & 0x00000017 ) ^ 0x00000000 ]
[ bitwise reg 1 = ( reg 1 & 0x00000002 ) ^ 0x00000000 ]
[ cmp neq reg 1 0x00000000 ]
Note the double bitwise expression. The last two expressions are not
correct either since it should match on the syn flag, ie. 0x2.
After this patch, netlink bytecode generation looks correct:
# nft --debug=netlink add rule meh tcp_flags 'tcp flags & (fin | syn | rst | ack) syn'
ip
[ meta load l4proto => reg 1 ]
[ cmp eq reg 1 0x00000006 ]
[ payload load 1b @ transport header + 13 => reg 1 ]
[ bitwise reg 1 = ( reg 1 & 0x00000017 ) ^ 0x00000000 ]
[ cmp eq reg 1 0x00000002 ]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'tests/py/inet/tcp.t.payload')
| -rw-r--r-- | tests/py/inet/tcp.t.payload | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/tests/py/inet/tcp.t.payload b/tests/py/inet/tcp.t.payload index 7f302080..eaa7cd09 100644 --- a/tests/py/inet/tcp.t.payload +++ b/tests/py/inet/tcp.t.payload @@ -370,6 +370,22 @@ inet test-inet input [ bitwise reg 1 = ( reg 1 & 0x00000003 ) ^ 0x00000000 ] [ cmp neq reg 1 0x00000002 ] +# tcp flags & (fin | syn | rst | ack) syn +inet test-inet input + [ meta load l4proto => reg 1 ] + [ cmp eq reg 1 0x00000006 ] + [ payload load 1b @ transport header + 13 => reg 1 ] + [ bitwise reg 1 = ( reg 1 & 0x00000017 ) ^ 0x00000000 ] + [ cmp eq reg 1 0x00000002 ] + +# tcp flags & (fin | syn | rst | ack) != syn +inet test-inet input + [ meta load l4proto => reg 1 ] + [ cmp eq reg 1 0x00000006 ] + [ payload load 1b @ transport header + 13 => reg 1 ] + [ bitwise reg 1 = ( reg 1 & 0x00000017 ) ^ 0x00000000 ] + [ cmp neq reg 1 0x00000002 ] + # tcp flags & (fin | syn | rst | psh | ack | urg | ecn | cwr) == fin | syn | rst | psh | ack | urg | ecn | cwr inet test-inet input [ meta load l4proto => reg 1 ] |