1 files changed, 141 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c b/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c
new file mode 100644
index 000000000000..3f9ffdf71343
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "test_progs.h"
+#include "network_helpers.h"
+#include "cgroup_helpers.h"
+#include "cgroup_ancestor.skel.h"
+
+#define CGROUP_PATH "/skb_cgroup_test"
+#define TEST_NS "cgroup_ancestor_ns"
+#define NUM_CGROUP_LEVELS 4
+#define WAIT_AUTO_IP_MAX_ATTEMPT 10
+#define DST_ADDR "::1"
+#define DST_PORT 1234
+#define MAX_ASSERT_NAME 32
+
+struct test_data {
+	struct cgroup_ancestor *skel;
+	struct bpf_tc_hook qdisc;
+	struct bpf_tc_opts tc_attach;
+	struct nstoken *ns;
+};
+
+static int send_datagram(void)
+{
+	unsigned char buf[] = "some random test data";
+	struct sockaddr_in6 addr = { .sin6_family = AF_INET6,
+				     .sin6_port = htons(DST_PORT), };
+	int sock, n;
+
+	if (!ASSERT_EQ(inet_pton(AF_INET6, DST_ADDR, &addr.sin6_addr), 1,
+		       "inet_pton"))
+		return -1;
+
+	sock = socket(AF_INET6, SOCK_DGRAM, 0);
+	if (!ASSERT_OK_FD(sock, "create socket"))
+		return sock;
+
+	if (!ASSERT_OK(connect(sock, (struct sockaddr *)&addr, sizeof(addr)), "connect")) {
+		close(sock);
+		return -1;
+	}
+
+	n = sendto(sock, buf, sizeof(buf), 0, (const struct sockaddr *)&addr,
+		   sizeof(addr));
+	close(sock);
+	return ASSERT_EQ(n, sizeof(buf), "send data") ? 0 : -1;
+}
+
+static int setup_network(struct test_data *t)
+{
+	SYS(fail, "ip netns add %s", TEST_NS);
+	t->ns = open_netns(TEST_NS);
+	if (!ASSERT_OK_PTR(t->ns, "open netns"))
+		goto cleanup_ns;
+
+	SYS(close_ns, "ip link set lo up");
+
+	memset(&t->qdisc, 0, sizeof(t->qdisc));
+	t->qdisc.sz = sizeof(t->qdisc);
+	t->qdisc.attach_point = BPF_TC_EGRESS;
+	t->qdisc.ifindex = if_nametoindex("lo");
+	if (!ASSERT_NEQ(t->qdisc.ifindex, 0, "if_nametoindex"))
+		goto close_ns;
+	if (!ASSERT_OK(bpf_tc_hook_create(&t->qdisc), "qdisc add"))
+		goto close_ns;
+
+	memset(&t->tc_attach, 0, sizeof(t->tc_attach));
+	t->tc_attach.sz = sizeof(t->tc_attach);
+	t->tc_attach.prog_fd = bpf_program__fd(t->skel->progs.log_cgroup_id);
+	if (!ASSERT_OK(bpf_tc_attach(&t->qdisc, &t->tc_attach), "filter add"))
+		goto cleanup_qdisc;
+
+	return 0;
+
+cleanup_qdisc:
+	bpf_tc_hook_destroy(&t->qdisc);
+close_ns:
+	close_netns(t->ns);
+cleanup_ns:
+	SYS_NOFAIL("ip netns del %s", TEST_NS);
+fail:
+	return 1;
+}
+
+static void cleanup_network(struct test_data *t)
+{
+	bpf_tc_detach(&t->qdisc, &t->tc_attach);
+	bpf_tc_hook_destroy(&t->qdisc);
+	close_netns(t->ns);
+	SYS_NOFAIL("ip netns del %s", TEST_NS);
+}
+
+static void check_ancestors_ids(struct test_data *t)
+{
+	__u64 expected_ids[NUM_CGROUP_LEVELS];
+	char assert_name[MAX_ASSERT_NAME];
+	__u32 level;
+
+	expected_ids[0] = get_cgroup_id("/.."); /* root cgroup */
+	expected_ids[1] = get_cgroup_id("");
+	expected_ids[2] = get_cgroup_id(CGROUP_PATH);
+	expected_ids[3] = 0; /* non-existent cgroup */
+
+	for (level = 0; level < NUM_CGROUP_LEVELS; level++) {
+		snprintf(assert_name, MAX_ASSERT_NAME,
+			 "ancestor id at level %d", level);
+		ASSERT_EQ(t->skel->bss->cgroup_ids[level], expected_ids[level],
+			  assert_name);
+	}
+}
+
+void test_cgroup_ancestor(void)
+{
+	struct test_data t;
+	int cgroup_fd;
+
+	t.skel = cgroup_ancestor__open_and_load();
+	if (!ASSERT_OK_PTR(t.skel, "open and load"))
+		return;
+
+	t.skel->bss->dport = htons(DST_PORT);
+	cgroup_fd = cgroup_setup_and_join(CGROUP_PATH);
+	if (cgroup_fd < 0)
+		goto cleanup_progs;
+
+	if (setup_network(&t))
+		goto cleanup_cgroups;
+
+	if (send_datagram())
+		goto cleanup_network;
+
+	check_ancestors_ids(&t);
+
+cleanup_network:
+	cleanup_network(&t);
+cleanup_cgroups:
+	close(cgroup_fd);
+	cleanup_cgroup_environment();
+cleanup_progs:
+	cgroup_ancestor__destroy(t.skel);
+}