Re: [PATCH bpf-next 6/6] selftests: bpf: test sockmap update from BPF

On 8/19/20 2:24 AM, Lorenz Bauer wrote:

Add a test which copies a socket from a sockmap into another sockmap or sockhash. This excercises bpf_map_update_elem support from BPF context. Compare the socket cookies from source and destination to ensure that the copy succeeded.

Signed-off-by: Lorenz Bauer lmb@cloudflare.com

.../selftests/bpf/prog_tests/sockmap_basic.c | 76 +++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_copy.c | 48 ++++++++++++ 2 files changed, 124 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 96e7b7f84c65..d30cabc00e9e 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -4,6 +4,7 @@ #include "test_progs.h" #include "test_skmsg_load_helpers.skel.h" +#include "test_sockmap_copy.skel.h" #define TCP_REPAIR 19 /* TCP sock is under repair right now */ @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type) test_skmsg_load_helpers__destroy(skel); } +static void test_sockmap_copy(enum bpf_map_type map_type) +{

• struct bpf_prog_test_run_attr attr;
• struct test_sockmap_copy *skel;
• __u64 src_cookie, dst_cookie;
• int err, prog, s, src, dst;
• const __u32 zero = 0;
• char dummy[14] = {0};
• s = connected_socket_v4();

Maybe change variable name to "sk" for better clarity?

• if (CHECK_FAIL(s == -1))

• return;
  

• skel = test_sockmap_copy__open_and_load();
• if (CHECK_FAIL(!skel)) {

• close(s);
  

• perror("test_sockmap_copy__open_and_load");
  

• return;
  

• }

Could you use CHECK instead of CHECK_FAIL? With CHECK, you can print additional information without perror.

• prog = bpf_program__fd(skel->progs.copy_sock_map);
• src = bpf_map__fd(skel->maps.src);
• if (map_type == BPF_MAP_TYPE_SOCKMAP)

• dst = bpf_map__fd(skel->maps.dst_sock_map);
  

• else

• dst = bpf_map__fd(skel->maps.dst_sock_hash);
  

• err = bpf_map_update_elem(src, &zero, &s, BPF_NOEXIST);

The map defined in bpf program is __u64 and here "s" is int. Any potential issues?

• if (CHECK_FAIL(err)) {

• perror("bpf_map_update");
  

• goto out;
  

• }
• err = bpf_map_lookup_elem(src, &zero, &src_cookie);
• if (CHECK_FAIL(err)) {

• perror("bpf_map_lookup_elem(src)");
  

• goto out;
  

• }
• attr = (struct bpf_prog_test_run_attr){

• .prog_fd = prog,
  

• .repeat = 1,
  

• .data_in = dummy,
  

• .data_size_in = sizeof(dummy),
  

• };
• err = bpf_prog_test_run_xattr(&attr);
• if (err) {

You can use CHECK macro here.

• test__fail();
  

• perror("bpf_prog_test_run");
  

• goto out;
  

• } else if (!attr.retval) {

• PRINT_FAIL("bpf_prog_test_run: program returned %u\n",
  

• 	   attr.retval);
  

• goto out;
  

• }
• err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);
• if (CHECK_FAIL(err)) {

• perror("bpf_map_lookup_elem(dst)");
  

• goto out;
  

• }
• if (dst_cookie != src_cookie)

• PRINT_FAIL("cookie %llu != %llu\n", dst_cookie, src_cookie);
  

Just replace the whole if statement with a CHECK macro.

+out:

• close(s);
• test_sockmap_copy__destroy(skel);

+}

• void test_sockmap_basic(void) { if (test__start_subtest("sockmap create_update_free"))

@@ -111,4 +183,8 @@ void test_sockmap_basic(void) test_skmsg_helpers(BPF_MAP_TYPE_SOCKMAP); if (test__start_subtest("sockhash sk_msg load helpers")) test_skmsg_helpers(BPF_MAP_TYPE_SOCKHASH);

• if (test__start_subtest("sockmap copy"))

• test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP);
  

• if (test__start_subtest("sockhash copy"))

• test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH);
  

  }

diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_copy.c b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c new file mode 100644 index 000000000000..9d0c9f28cab2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Cloudflare +#include "vmlinux.h" +#include <bpf/bpf_helpers.h>

+struct {

• __uint(type, BPF_MAP_TYPE_SOCKMAP);
• __uint(max_entries, 1);
• __type(key, __u32);
• __type(value, __u64);

+} src SEC(".maps");

+struct {

• __uint(type, BPF_MAP_TYPE_SOCKMAP);
• __uint(max_entries, 1);
• __type(key, __u32);
• __type(value, __u64);

+} dst_sock_map SEC(".maps");

+struct {

• __uint(type, BPF_MAP_TYPE_SOCKHASH);
• __uint(max_entries, 1);
• __type(key, __u32);
• __type(value, __u64);

+} dst_sock_hash SEC(".maps");

+SEC("classifier/copy_sock_map") +int copy_sock_map(void *ctx) +{

• struct bpf_sock *sk;
• bool failed = false;
• __u32 key = 0;
• sk = bpf_map_lookup_elem(&src, &key);
• if (!sk)

• return SK_DROP;
  

• if (bpf_map_update_elem(&dst_sock_map, &key, sk, 0))

• failed = true;
  

• if (bpf_map_update_elem(&dst_sock_hash, &key, sk, 0))

• failed = true;
  

• bpf_sk_release(sk);
• return failed ? SK_DROP : SK_PASS;

+}

+char _license[] SEC("license") = "GPL";