[Patch bpf-next v8 16/16] selftests/bpf: add a test case for loading BPF_SK_SKB_VERDICT

[Cong Wang]

From: Cong Wang <cong.w...@bytedance.com>

This adds a test case to ensure BPF_SK_SKB_VERDICT and
BPF_SK_STREAM_VERDICT will never be attached at the same time.

Cc: John Fastabend <john.fastab...@gmail.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Jakub Sitnicki <ja...@cloudflare.com>
Cc: Lorenz Bauer <l...@cloudflare.com>
Signed-off-by: Cong Wang <cong.w...@bytedance.com>
---
 .../selftests/bpf/prog_tests/sockmap_basic.c  | 40 +++++++++++++++++++
 .../progs/test_sockmap_skb_verdict_attach.c   | 18 +++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 
tools/testing/selftests/bpf/progs/test_sockmap_skb_verdict_attach.c

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c 
b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index b8b48cac2ac3..ab77596b64e3 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -7,6 +7,7 @@
 #include "test_skmsg_load_helpers.skel.h"
 #include "test_sockmap_update.skel.h"
 #include "test_sockmap_invalid_update.skel.h"
+#include "test_sockmap_skb_verdict_attach.skel.h"
 #include "bpf_iter_sockmap.skel.h"
 
 #define TCP_REPAIR             19      /* TCP sock is under repair right now */
@@ -281,6 +282,39 @@ static void test_sockmap_copy(enum bpf_map_type map_type)
        bpf_iter_sockmap__destroy(skel);
 }
 
+static void test_sockmap_skb_verdict_attach(enum bpf_attach_type first,
+                                           enum bpf_attach_type second)
+{
+       struct test_sockmap_skb_verdict_attach *skel;
+       int err, map, verdict;
+
+       skel = test_sockmap_skb_verdict_attach__open_and_load();
+       if (CHECK_FAIL(!skel)) {
+               perror("test_sockmap_skb_verdict_attach__open_and_load");
+               return;
+       }
+
+       verdict = bpf_program__fd(skel->progs.prog_skb_verdict);
+       map = bpf_map__fd(skel->maps.sock_map);
+
+       err = bpf_prog_attach(verdict, map, first, 0);
+       if (CHECK_FAIL(err)) {
+               perror("bpf_prog_attach");
+               goto out;
+       }
+
+       err = bpf_prog_attach(verdict, map, second, 0);
+       assert(err == -1 && errno == EBUSY);
+
+       err = bpf_prog_detach2(verdict, map, first);
+       if (CHECK_FAIL(err)) {
+               perror("bpf_prog_detach2");
+               goto out;
+       }
+out:
+       test_sockmap_skb_verdict_attach__destroy(skel);
+}
+
 void test_sockmap_basic(void)
 {
        if (test__start_subtest("sockmap create_update_free"))
@@ -301,4 +335,10 @@ void test_sockmap_basic(void)
                test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP);
        if (test__start_subtest("sockhash copy"))
                test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH);
+       if (test__start_subtest("sockmap skb_verdict attach")) {
+               test_sockmap_skb_verdict_attach(BPF_SK_SKB_VERDICT,
+                                               BPF_SK_SKB_STREAM_VERDICT);
+               test_sockmap_skb_verdict_attach(BPF_SK_SKB_STREAM_VERDICT,
+                                               BPF_SK_SKB_VERDICT);
+       }
 }
diff --git 
a/tools/testing/selftests/bpf/progs/test_sockmap_skb_verdict_attach.c 
b/tools/testing/selftests/bpf/progs/test_sockmap_skb_verdict_attach.c
new file mode 100644
index 000000000000..2d31f66e4f23
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_sockmap_skb_verdict_attach.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+struct {
+       __uint(type, BPF_MAP_TYPE_SOCKMAP);
+       __uint(max_entries, 2);
+       __type(key, __u32);
+       __type(value, __u64);
+} sock_map SEC(".maps");
+
+SEC("sk_skb/skb_verdict")
+int prog_skb_verdict(struct __sk_buff *skb)
+{
+       return SK_DROP;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.25.1