This ensures that buffers retrieved from dynptr_data are allowed to be
passed in to helpers that take mem, like bpf_strncmp
Signed-off-by: Daniel Rosenberg <[email protected]>
---
.../testing/selftests/bpf/prog_tests/dynptr.c | 1 +
.../selftests/bpf/progs/dynptr_success.c | 21 +++++++++++++++++++
2 files changed, 22 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index 13d4b9ab16e7..7cfac53c0d58 100644
--- a/tools/testing/selftests/bpf/prog_tests/dynptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -27,6 +27,7 @@ static struct {
{"test_dynptr_is_rdonly", SETUP_SKB_PROG},
{"test_dynptr_clone", SETUP_SKB_PROG},
{"test_dynptr_skb_no_buff", SETUP_SKB_PROG},
+ {"test_dynptr_skb_strcmp", SETUP_SKB_PROG},
};
static void verify_success(const char *prog_name, enum test_setup_type setup_type)
diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c
index d299ef3b4d1f..0c053976f8f9 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -522,3 +522,24 @@ int test_dynptr_skb_no_buff(struct __sk_buff *skb)
return !!data;
}
+
+SEC("?cgroup_skb/egress")
+int test_dynptr_skb_strcmp(struct __sk_buff *skb)
+{
+ struct bpf_dynptr ptr;
+ char *data;
+
+ if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
+ err = 1;
+ return 1;
+ }
+
+ /* This may return NULL. SKB may require a buffer */
+ data = bpf_dynptr_slice(&ptr, 0, NULL, 10);
+ if (data) {
+ bpf_strncmp(data, 10, "foo");
+ return 1;
+ }
+
+ return 1;
+}
--
2.40.1.521.gf1e218fcd8-goog