diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c index 1ab095bcacd8..d8803dfa8d32 100644 --- a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c +++ b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c @@ -19,10 +19,29 @@ struct bpf_map_def SEC("maps") results = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(__u32), - .value_size = sizeof(__u64), - .max_entries = 1, + .value_size = sizeof(__u32), + .max_entries = 3, }; +static __always_inline __s64 gen_syncookie(void *data_end, struct bpf_sock *sk, + void *iph, __u32 ip_size, + struct tcphdr *tcph) +{ + __u32 thlen = tcph->doff * 4; + + if (tcph->syn && !tcph->ack) { + // packet should only have an MSS option + if (thlen != 24) + return 0; + + if ((void *)tcph + thlen > data_end) + return 0; + + return bpf_tcp_gen_syncookie(sk, iph, ip_size, tcph, thlen); + } + return 0; +} + static __always_inline void check_syncookie(void *ctx, void *data, void *data_end) { @@ -33,8 +52,10 @@ static __always_inline void check_syncookie(void *ctx, void *data, struct ipv6hdr *ipv6h; struct tcphdr *tcph; int ret; + __u32 key_mss = 2; + __u32 key_gen = 1; __u32 key = 0; - __u64 value = 1; + __s64 seq_mss; ethh = data; if (ethh + 1 > data_end) @@ -66,6 +87,9 @@ static __always_inline void check_syncookie(void *ctx, void *data, if (sk->state != BPF_TCP_LISTEN) goto release; + seq_mss = gen_syncookie(data_end, sk, ipv4h, sizeof(*ipv4h), + tcph); + ret = bpf_tcp_check_syncookie(sk, ipv4h, sizeof(*ipv4h), tcph, sizeof(*tcph)); break; @@ -95,6 +119,9 @@ static __always_inline void check_syncookie(void *ctx, void *data, if (sk->state != BPF_TCP_LISTEN) goto release; + seq_mss = gen_syncookie(data_end, sk, ipv6h, sizeof(*ipv6h), + tcph); + ret = bpf_tcp_check_syncookie(sk, ipv6h, sizeof(*ipv6h), tcph, sizeof(*tcph)); break; @@ -103,8 +130,19 @@ static __always_inline void check_syncookie(void *ctx, void *data, return; } - if (ret == 0) - bpf_map_update_elem(&results, &key, &value, 0); + if (seq_mss > 0) { + __u32 cookie = (__u32)seq_mss; + __u32 mss = seq_mss >> 32; + + bpf_map_update_elem(&results, &key_gen, &cookie, 0); + bpf_map_update_elem(&results, &key_mss, &mss, 0); + } + + if (ret == 0) { + __u32 cookie = bpf_ntohl(tcph->ack_seq) - 1; + + bpf_map_update_elem(&results, &key, &cookie, 0); + } release: bpf_sk_release(sk); |