bpf: Add tests for bpf_sk_storage to bpf_tcp_ca

This patch adds test to exercise the bpf_sk_storage_get()
and bpf_sk_storage_delete() helper from the bpf_dctcp.c.

The setup and check on the sk_storage is done immediately
before and after the connect().

This patch also takes this chance to move the pthread_create()
after the connect() has been done.  That will remove the need of
the "wait_thread" label.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200320152107.2169904-1-kafai@fb.com

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
index 8482bbc..9a8f47f 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
@@ -11,6 +11,7 @@
 static const unsigned int total_bytes = 10 * 1024 * 1024;
 static const struct timeval timeo_sec = { .tv_sec = 10 };
 static const size_t timeo_optlen = sizeof(timeo_sec);
+static int expected_stg = 0xeB9F;
 static int stop, duration;
 
 static int settimeo(int fd)
@@ -88,7 +89,7 @@ done:
        return NULL;
 }
 
-static void do_test(const char *tcp_ca)
+static void do_test(const char *tcp_ca, const struct bpf_map *sk_stg_map)
 {
        struct sockaddr_in6 sa6 = {};
        ssize_t nr_recv = 0, bytes = 0;
@@ -126,14 +127,34 @@ static void do_test(const char *tcp_ca)
        err = listen(lfd, 1);
        if (CHECK(err == -1, "listen", "errno:%d\n", errno))
                goto done;
-       err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
-       if (CHECK(err != 0, "pthread_create", "err:%d\n", err))
-               goto done;
+
+       if (sk_stg_map) {
+               err = bpf_map_update_elem(bpf_map__fd(sk_stg_map), &fd,
+                                         &expected_stg, BPF_NOEXIST);
+               if (CHECK(err, "bpf_map_update_elem(sk_stg_map)",
+                         "err:%d errno:%d\n", err, errno))
+                       goto done;
+       }
 
        /* connect to server */
        err = connect(fd, (struct sockaddr *)&sa6, addrlen);
        if (CHECK(err == -1, "connect", "errno:%d\n", errno))
-               goto wait_thread;
+               goto done;
+
+       if (sk_stg_map) {
+               int tmp_stg;
+
+               err = bpf_map_lookup_elem(bpf_map__fd(sk_stg_map), &fd,
+                                         &tmp_stg);
+               if (CHECK(!err || errno != ENOENT,
+                         "bpf_map_lookup_elem(sk_stg_map)",
+                         "err:%d errno:%d\n", err, errno))
+                       goto done;
+       }
+
+       err = pthread_create(&srv_thread, NULL, server, (void *)(long)lfd);
+       if (CHECK(err != 0, "pthread_create", "err:%d errno:%d\n", err, errno))
+               goto done;
 
        /* recv total_bytes */
        while (bytes < total_bytes && !READ_ONCE(stop)) {
@@ -149,7 +170,6 @@ static void do_test(const char *tcp_ca)
        CHECK(bytes != total_bytes, "recv", "%zd != %u nr_recv:%zd errno:%d\n",
              bytes, total_bytes, nr_recv, errno);
 
-wait_thread:
        WRITE_ONCE(stop, 1);
        pthread_join(srv_thread, &thread_ret);
        CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
@@ -175,7 +195,7 @@ static void test_cubic(void)
                return;
        }
 
-       do_test("bpf_cubic");
+       do_test("bpf_cubic", NULL);
 
        bpf_link__destroy(link);
        bpf_cubic__destroy(cubic_skel);
@@ -197,7 +217,10 @@ static void test_dctcp(void)
                return;
        }
 
-       do_test("bpf_dctcp");
+       do_test("bpf_dctcp", dctcp_skel->maps.sk_stg_map);
+       CHECK(dctcp_skel->bss->stg_result != expected_stg,
+             "Unexpected stg_result", "stg_result (%x) != expected_stg (%x)\n",
+             dctcp_skel->bss->stg_result, expected_stg);
 
        bpf_link__destroy(link);
        bpf_dctcp__destroy(dctcp_skel);

diff --git a/tools/testing/selftests/bpf/progs/bpf_dctcp.c b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
index 127ea76..3fb4260 100644 (file)
--- a/tools/testing/selftests/bpf/progs/bpf_dctcp.c
+++ b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
@@ -6,6 +6,7 @@
  * the kernel BPF logic.
  */
 
+#include <stddef.h>
 #include <linux/bpf.h>
 #include <linux/types.h>
 #include <bpf/bpf_helpers.h>
@@ -14,6 +15,15 @@
 
 char _license[] SEC("license") = "GPL";
 
+int stg_result = 0;
+
+struct {
+       __uint(type, BPF_MAP_TYPE_SK_STORAGE);
+       __uint(map_flags, BPF_F_NO_PREALLOC);
+       __type(key, int);
+       __type(value, int);
+} sk_stg_map SEC(".maps");
+
 #define DCTCP_MAX_ALPHA        1024U
 
 struct dctcp {
@@ -43,12 +53,18 @@ void BPF_PROG(dctcp_init, struct sock *sk)
 {
        const struct tcp_sock *tp = tcp_sk(sk);
        struct dctcp *ca = inet_csk_ca(sk);
+       int *stg;
 
        ca->prior_rcv_nxt = tp->rcv_nxt;
        ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA);
        ca->loss_cwnd = 0;
        ca->ce_state = 0;
 
+       stg = bpf_sk_storage_get(&sk_stg_map, (void *)tp, NULL, 0);
+       if (stg) {
+               stg_result = *stg;
+               bpf_sk_storage_delete(&sk_stg_map, (void *)tp);
+       }
        dctcp_reset(tp, ca);
 }