[PATCH v3 bpf-next 3/3] selftests/bpf: add selftest for get_netns_id helper

[Lingpeng Chen <forrest0579@xxxxxxxxx>]

adding selftest for new bpf helper function get_netns_id

Signed-off-by: Lingpeng Chen <forrest0579@xxxxxxxxx>
---
 .../selftests/bpf/progs/test_tcpbpf_kern.c    | 11 +++++
 .../testing/selftests/bpf/test_tcpbpf_user.c  | 46 ++++++++++++++++++-
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
index 1f1966e86e9f..d7d851ddd2cc 100644
--- a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
@@ -28,6 +28,13 @@ struct {
 	__type(value, int);
 } sockopt_results SEC(".maps");
 
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} netns_number SEC(".maps");
+
 static inline void update_event_map(int event)
 {
 	__u32 key = 0;
@@ -61,6 +68,7 @@ int bpf_testcb(struct bpf_sock_ops *skops)
 	int rv = -1;
 	int v = 0;
 	int op;
+	__u64 netns_id;
 
 	op = (int) skops->op;
 
@@ -144,6 +152,9 @@ int bpf_testcb(struct bpf_sock_ops *skops)
 		__u32 key = 0;
 
 		bpf_map_update_elem(&sockopt_results, &key, &v, BPF_ANY);
+
+		netns_id = bpf_get_netns_id(skops);
+		bpf_map_update_elem(&netns_number, &key, &netns_id, BPF_ANY);
 		break;
 	default:
 		rv = -1;
diff --git a/tools/testing/selftests/bpf/test_tcpbpf_user.c b/tools/testing/selftests/bpf/test_tcpbpf_user.c
index 3ae127620463..fef2f4d77ecc 100644
--- a/tools/testing/selftests/bpf/test_tcpbpf_user.c
+++ b/tools/testing/selftests/bpf/test_tcpbpf_user.c
@@ -76,6 +76,41 @@ int verify_sockopt_result(int sock_map_fd)
 	return ret;
 }
 
+int verify_netns(__u64 netns_id)
+{
+	char buf1[40];
+	char buf2[40];
+	int ret = 0;
+	ssize_t len = 0;
+
+	len = readlink("/proc/self/ns/net", buf1, 39);
+	sprintf(buf2, "net:[%llu]", netns_id);
+
+	if (len <= 0) {
+		printf("FAILED: readlink /proc/self/ns/net");
+		return ret;
+	}
+
+	if (strncmp(buf1, buf2, len)) {
+		printf("FAILED: netns don't match");
+		ret = 1;
+	}
+	return ret;
+}
+
+int verify_netns_result(int netns_map_fd)
+{
+	__u32 key = 0;
+	__u64 res = 0;
+	int ret = 0;
+	int rv;
+
+	rv = bpf_map_lookup_elem(netns_map_fd, &key, &res);
+	EXPECT_EQ(0, rv, "d");
+
+	return verify_netns(res);
+}
+
 static int bpf_find_map(const char *test, struct bpf_object *obj,
 			const char *name)
 {
@@ -92,7 +127,7 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
 int main(int argc, char **argv)
 {
 	const char *file = "test_tcpbpf_kern.o";
-	int prog_fd, map_fd, sock_map_fd;
+	int prog_fd, map_fd, sock_map_fd, netns_map_fd;
 	struct tcpbpf_globals g = {0};
 	const char *cg_path = "/foo";
 	int error = EXIT_FAILURE;
@@ -137,6 +172,10 @@ int main(int argc, char **argv)
 	if (sock_map_fd < 0)
 		goto err;
 
+	netns_map_fd = bpf_find_map(__func__, obj, "netns_number");
+	if (netns_map_fd < 0)
+		goto err;
+
 retry_lookup:
 	rv = bpf_map_lookup_elem(map_fd, &key, &g);
 	if (rv != 0) {
@@ -161,6 +200,11 @@ int main(int argc, char **argv)
 		goto err;
 	}
 
+	if (verify_netns_result(netns_map_fd)) {
+		printf("FAILED: Wrong netns stats\n");
+		goto err;
+	}
+
 	printf("PASSED!\n");
 	error = 0;
 err:
-- 
2.20.1