1 files changed, 61 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/udp_limit.c b/tools/testing/selftests/bpf/progs/udp_limit.c
new file mode 100644
index 000000000000..165e3c2dd9a3
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/udp_limit.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <sys/socket.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+int invocations = 0, in_use = 0;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+	__type(key, int);
+	__type(value, int);
+} sk_map SEC(".maps");
+
+SEC("cgroup/sock_create")
+int sock(struct bpf_sock *ctx)
+{
+	int *sk_storage;
+	__u32 key;
+
+	if (ctx->type != SOCK_DGRAM)
+		return 1;
+
+	sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0,
+					BPF_SK_STORAGE_GET_F_CREATE);
+	if (!sk_storage)
+		return 0;
+	*sk_storage = 0xdeadbeef;
+
+	__sync_fetch_and_add(&invocations, 1);
+
+	if (in_use > 0) {
+		/* BPF_CGROUP_INET_SOCK_RELEASE is _not_ called
+		 * when we return an error from the BPF
+		 * program!
+		 */
+		return 0;
+	}
+
+	__sync_fetch_and_add(&in_use, 1);
+	return 1;
+}
+
+SEC("cgroup/sock_release")
+int sock_release(struct bpf_sock *ctx)
+{
+	int *sk_storage;
+	__u32 key;
+
+	if (ctx->type != SOCK_DGRAM)
+		return 1;
+
+	sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0, 0);
+	if (!sk_storage || *sk_storage != 0xdeadbeef)
+		return 0;
+
+	__sync_fetch_and_add(&invocations, 1);
+	__sync_fetch_and_add(&in_use, -1);
+	return 1;
+}