From f69f1ba9092d40510c3b5cf44ac28d0133d2751f Mon Sep 17 00:00:00 2001 From: Hou Tao <houtao1@huawei.com> Date: Wed, 10 Aug 2022 16:05:37 +0800 Subject: [PATCH] selftests/bpf: Add write tests for sk local storage map iterator Add test to validate the overwrite of sock local storage map value in map iterator and another one to ensure out-of-bound value writing is rejected. Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220810080538.1845898-9-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> --- .../selftests/bpf/prog_tests/bpf_iter.c | 20 +++++++++++++++-- .../bpf/progs/bpf_iter_bpf_sk_storage_map.c | 22 +++++++++++++++++-- 2 files changed, 38 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index b690c9e9d3463..1571a6586b3b1 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -1076,7 +1076,7 @@ static void test_bpf_sk_stoarge_map_iter_fd(void) if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_sk_storage_map__open_and_load")) return; - do_read_map_iter_fd(&skel->skeleton, skel->progs.dump_bpf_sk_storage_map, + do_read_map_iter_fd(&skel->skeleton, skel->progs.rw_bpf_sk_storage_map, skel->maps.sk_stg_map); bpf_iter_bpf_sk_storage_map__destroy(skel); @@ -1117,7 +1117,15 @@ static void test_bpf_sk_storage_map(void) linfo.map.map_fd = map_fd; opts.link_info = &linfo; opts.link_info_len = sizeof(linfo); - link = bpf_program__attach_iter(skel->progs.dump_bpf_sk_storage_map, &opts); + link = bpf_program__attach_iter(skel->progs.oob_write_bpf_sk_storage_map, &opts); + err = libbpf_get_error(link); + if (!ASSERT_EQ(err, -EACCES, "attach_oob_write_iter")) { + if (!err) + bpf_link__destroy(link); + goto out; + } + + link = bpf_program__attach_iter(skel->progs.rw_bpf_sk_storage_map, &opts); if (!ASSERT_OK_PTR(link, "attach_iter")) goto out; @@ -1125,6 +1133,7 @@ static void test_bpf_sk_storage_map(void) if (!ASSERT_GE(iter_fd, 0, "create_iter")) goto free_link; + skel->bss->to_add_val = time(NULL); /* do some tests */ while ((len = read(iter_fd, buf, sizeof(buf))) > 0) ; @@ -1138,6 +1147,13 @@ static void test_bpf_sk_storage_map(void) if (!ASSERT_EQ(skel->bss->val_sum, expected_val, "val_sum")) goto close_iter; + for (i = 0; i < num_sockets; i++) { + err = bpf_map_lookup_elem(map_fd, &sock_fd[i], &val); + if (!ASSERT_OK(err, "map_lookup") || + !ASSERT_EQ(val, i + 1 + skel->bss->to_add_val, "check_map_value")) + break; + } + close_iter: close(iter_fd); free_link: diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_map.c b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_map.c index 6b70ccaba301f..c7b8e006b171a 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_map.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_map.c @@ -16,19 +16,37 @@ struct { __u32 val_sum = 0; __u32 ipv6_sk_count = 0; +__u32 to_add_val = 0; SEC("iter/bpf_sk_storage_map") -int dump_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx) +int rw_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx) { struct sock *sk = ctx->sk; __u32 *val = ctx->value; - if (sk == (void *)0 || val == (void *)0) + if (sk == NULL || val == NULL) return 0; if (sk->sk_family == AF_INET6) ipv6_sk_count++; val_sum += *val; + + *val += to_add_val; + + return 0; +} + +SEC("iter/bpf_sk_storage_map") +int oob_write_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx) +{ + struct sock *sk = ctx->sk; + __u32 *val = ctx->value; + + if (sk == NULL || val == NULL) + return 0; + + *(val + 1) = 0xdeadbeef; + return 0; } -- 2.39.5