selftests/bpf: Verify socket storage in cgroup/sock_{create, release}

Augment udp_limit test to set and verify socket storage value.
That should be enough to exercise the changes from the previous
patch.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200729003104.1280813-2-sdf@google.com

diff --git a/tools/testing/selftests/bpf/progs/udp_limit.c b/tools/testing/selftests/bpf/progs/udp_limit.c
index 8429b22525a7961883240c89b64694c21039db3e..165e3c2dd9a3d3604b64163c75ce471983a0ae80 100644 (file)
--- a/tools/testing/selftests/bpf/progs/udp_limit.c
+++ b/tools/testing/selftests/bpf/progs/udp_limit.c
@@ -6,14 +6,28 @@
 
 int invocations = 0, in_use = 0;
 
+struct {
+       __uint(type, BPF_MAP_TYPE_SK_STORAGE);
+       __uint(map_flags, BPF_F_NO_PREALLOC);
+       __type(key, int);
+       __type(value, int);
+} sk_map SEC(".maps");
+
 SEC("cgroup/sock_create")
 int sock(struct bpf_sock *ctx)
 {
+       int *sk_storage;
        __u32 key;
 
        if (ctx->type != SOCK_DGRAM)
                return 1;
 
+       sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0,
+                                       BPF_SK_STORAGE_GET_F_CREATE);
+       if (!sk_storage)
+               return 0;
+       *sk_storage = 0xdeadbeef;
+
        __sync_fetch_and_add(&invocations, 1);
 
        if (in_use > 0) {
@@ -31,11 +45,16 @@ int sock(struct bpf_sock *ctx)
 SEC("cgroup/sock_release")
 int sock_release(struct bpf_sock *ctx)
 {
+       int *sk_storage;
        __u32 key;
 
        if (ctx->type != SOCK_DGRAM)
                return 1;
 
+       sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0, 0);
+       if (!sk_storage || *sk_storage != 0xdeadbeef)
+               return 0;
+
        __sync_fetch_and_add(&invocations, 1);
        __sync_fetch_and_add(&in_use, -1);
        return 1;