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); diff --git a/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh b/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh index d48e51716d19..9b3617d770a5 100755 --- a/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh +++ b/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh @@ -37,6 +37,9 @@ setup() ns1_exec ip link set lo up ns1_exec sysctl -w net.ipv4.tcp_syncookies=2 + ns1_exec sysctl -w net.ipv4.tcp_window_scaling=0 + ns1_exec sysctl -w net.ipv4.tcp_timestamps=0 + ns1_exec sysctl -w net.ipv4.tcp_sack=0 wait_for_ip 127.0.0.1 wait_for_ip ::1 diff --git a/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c b/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c index 87829c86c746..b9e991d43155 100644 --- a/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c +++ b/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c @@ -2,6 +2,7 @@ // Copyright (c) 2018 Facebook // Copyright (c) 2019 Cloudflare +#include #include #include #include @@ -77,7 +78,7 @@ out: return fd; } -static int get_map_fd_by_prog_id(int prog_id) +static int get_map_fd_by_prog_id(int prog_id, bool *xdp) { struct bpf_prog_info info = {}; __u32 info_len = sizeof(info); @@ -104,6 +105,8 @@ static int get_map_fd_by_prog_id(int prog_id) goto err; } + *xdp = info.type == BPF_PROG_TYPE_XDP; + map_fd = bpf_map_get_fd_by_id(map_ids[0]); if (map_fd < 0) log_err("Failed to get fd by map id %d", map_ids[0]); @@ -113,18 +116,32 @@ err: return map_fd; } -static int run_test(int server_fd, int results_fd) +static int run_test(int server_fd, int results_fd, bool xdp) { int client = -1, srv_client = -1; int ret = 0; __u32 key = 0; - __u64 value = 0; + __u32 key_gen = 1; + __u32 key_mss = 2; + __u32 value = 0; + __u32 value_gen = 0; + __u32 value_mss = 0; if (bpf_map_update_elem(results_fd, &key, &value, 0) < 0) { log_err("Can't clear results"); goto err; } + if (bpf_map_update_elem(results_fd, &key_gen, &value_gen, 0) < 0) { + log_err("Can't clear results"); + goto err; + } + + if (bpf_map_update_elem(results_fd, &key_mss, &value_mss, 0) < 0) { + log_err("Can't clear results"); + goto err; + } + client = connect_to_server(server_fd); if (client == -1) goto err; @@ -140,8 +157,35 @@ static int run_test(int server_fd, int results_fd) goto err; } - if (value != 1) { - log_err("Didn't match syncookie: %llu", value); + if (value == 0) { + log_err("Didn't match syncookie: %u", value); + goto err; + } + + if (bpf_map_lookup_elem(results_fd, &key_gen, &value_gen) < 0) { + log_err("Can't lookup result"); + goto err; + } + + if (xdp && value_gen == 0) { + // SYN packets do not get passed through generic XDP, skip the + // rest of the test. + printf("Skipping XDP cookie check\n"); + goto out; + } + + if (bpf_map_lookup_elem(results_fd, &key_mss, &value_mss) < 0) { + log_err("Can't lookup result"); + goto err; + } + + if (value != value_gen) { + log_err("BPF generated cookie does not match kernel one"); + goto err; + } + + if (value_mss < 536 || value_mss > USHRT_MAX) { + log_err("Unexpected MSS retrieved"); goto err; } @@ -163,13 +207,14 @@ int main(int argc, char **argv) int server_v6 = -1; int results = -1; int err = 0; + bool xdp; if (argc < 2) { fprintf(stderr, "Usage: %s prog_id\n", argv[0]); exit(1); } - results = get_map_fd_by_prog_id(atoi(argv[1])); + results = get_map_fd_by_prog_id(atoi(argv[1]), &xdp); if (results < 0) { log_err("Can't get map"); goto err; @@ -194,10 +239,10 @@ int main(int argc, char **argv) if (server_v6 == -1) goto err; - if (run_test(server, results)) + if (run_test(server, results, xdp)) goto err; - if (run_test(server_v6, results)) + if (run_test(server_v6, results, xdp)) goto err; printf("ok\n");