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>
This commit is contained in:
Hou Tao 2022-08-10 16:05:37 +08:00 committed by Alexei Starovoitov
parent 5836d81e4b
commit 939a1a946d
2 changed files with 38 additions and 4 deletions

View File

@ -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:

View File

@ -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;
}