On Tue, Oct 19, 2021 at 05:46:55PM +0300, Maxim Mikityanskiy wrote:

This commit adds a sample for the new BPF helpers: bpf_ct_lookup_tcp,
bpf_tcp_raw_gen_syncookie and bpf_tcp_raw_check_syncookie.

samples/bpf/syncookie_kern.c is a BPF program that generates SYN cookies
on allowed TCP ports and sends SYNACKs to clients, accelerating synproxy
iptables module.

samples/bpf/syncookie_user.c is a userspace control application that
allows to configure the following options in runtime: list of allowed
ports, MSS, window scale, TTL.

samples/bpf/syncookie_test.sh is a script that demonstrates the setup of
synproxy with XDP acceleration.

Signed-off-by: Maxim Mikityanskiy <redacted>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
---
 samples/bpf/.gitignore        |   1 +
 samples/bpf/Makefile          |   3 +
 samples/bpf/syncookie_kern.c  | 591 ++++++++++++++++++++++++++++++++++
 samples/bpf/syncookie_test.sh |  55 ++++
 samples/bpf/syncookie_user.c  | 388 ++++++++++++++++++++++
 5 files changed, 1038 insertions(+)
 create mode 100644 samples/bpf/syncookie_kern.c
 create mode 100755 samples/bpf/syncookie_test.sh
 create mode 100644 samples/bpf/syncookie_user.c

Tests should be in selftests/bpf.
Samples are for samples only.

+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB

Isn't it deprecated?
LICENSES/deprecated/Linux-OpenIB

+	// Don't combine additions to avoid 32-bit overflow.

c++ style comment?
did you run checkpatch?