One remaining difference between test_tcp_check_syncookie.sh and btf_skc_cls_ingress is a small test on the mss value embedded in the cookie generated with the eBPF helper.
Bring the corresponding test in btf_skc_cls_ingress.
Signed-off-by: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com --- tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c | 7 +++++++ tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c | 2 ++ 2 files changed, 9 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c index e0f8fe818f4230a1d5bf0118133c5a9fb50345e1..64601bafdd23e7fb13ebd496ac914660685f1efc 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c @@ -27,6 +27,8 @@ #define SERVER_ADDR_IPV4 "127.0.0.1" #define SERVER_ADDR_IPV6 "::1" #define SERVER_ADDR_DUAL "::0" +/* RFC791, 576 for minimal IPv4 datagram, minus 40 bytes of TCP header */ +#define MIN_IPV4_MSS 536
static struct netns_obj *prepare_netns(struct test_btf_skc_cls_ingress *skel) { @@ -73,6 +75,7 @@ static void reset_test(struct test_btf_skc_cls_ingress *skel) skel->bss->recv_cookie = 0; skel->bss->gen_cookie = 0; skel->bss->linum = 0; + skel->bss->mss = 0; }
static void print_err_line(struct test_btf_skc_cls_ingress *skel) @@ -184,6 +187,10 @@ static void run_test(struct test_btf_skc_cls_ingress *skel, bool gen_cookies, "syncookie properly generated"); ASSERT_EQ(skel->bss->gen_cookie, skel->bss->recv_cookie, "matching syncookies on client and server"); + ASSERT_GT(skel->bss->mss, MIN_IPV4_MSS, + "MSS in cookie min value"); + ASSERT_LT(skel->bss->mss, USHRT_MAX, + "MSS in cookie max value"); }
done: diff --git a/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c index cd528f8792ff2eb14683cbc13e8b0f3fd38329e9..3810ce98d3d54276f9a0130a887f59c79a21288e 100644 --- a/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c +++ b/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c @@ -15,6 +15,7 @@ __u16 listen_tp_sport = 0; __u16 req_sk_sport = 0; __u32 recv_cookie = 0; __u32 gen_cookie = 0; +__u32 mss = 0; __u32 linum = 0;
#define LOG() ({ if (!linum) linum = __LINE__; }) @@ -46,6 +47,7 @@ static void test_syncookie_helper(void *iphdr, int iphdr_size, LOG(); } else { gen_cookie = (__u32)mss_cookie; + mss = mss_cookie >> 32; } } else if (gen_cookie) { /* It was in cookie mode */