ip_size 27 tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c void *iph, __u32 ip_size, ip_size 40 tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c return bpf_tcp_gen_syncookie(sk, iph, ip_size, tcph, thlen);