Add a few selftests which allows cgroup prog top-down ordering.
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/cgroup_topdown.c | 128 ++++++++++++++++++
.../selftests/bpf/progs/cgroup_topdown.c | 41 ++++++
2 files changed, 169 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/cgroup_topdown.c
create mode 100644 tools/testing/selftests/bpf/progs/cgroup_topdown.c
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_topdown.c b/tools/testing/selftests/bpf/prog_tests/cgroup_topdown.c
new file mode 100644
index 000000000000..61e89ab7f6fd
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_topdown.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
+#include <test_progs.h>
+#include "cgroup_helpers.h"
+#include "cgroup_topdown.skel.h"
+
+static int run_getsockopt_test(int cg_parent, int cg_child, int sock_fd, bool all_topdown)
+{
+ LIBBPF_OPTS(bpf_prog_attach_opts, opts);
+ enum bpf_attach_type prog_c_atype, prog_c2_atype, prog_p_atype, prog_p2_atype;
+ int prog_c_fd, prog_c2_fd, prog_p_fd, prog_p2_fd;
+ struct cgroup_topdown *skel = NULL;
+ struct bpf_program *prog;
+ __u8 *result, buf;
+ socklen_t optlen;
+ int err = 0;
+
+ skel = cgroup_topdown__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "cgroup_topdown__open_and_load"))
+ return 0;
+
+ buf = 0x00;
+ err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
+ if (!ASSERT_OK(err, "setsockopt"))
+ goto close_skel;
+
+ opts.flags = BPF_F_ALLOW_MULTI;
+ if (all_topdown)
+ opts.flags |= BPF_F_PRIO_TOPDOWN;
+ prog = skel->progs.child;
+ prog_c_fd = bpf_program__fd(prog);
+ prog_c_atype = bpf_program__expected_attach_type(prog);
+ err = bpf_prog_attach_opts(prog_c_fd, cg_child, prog_c_atype, &opts);
+ if (!ASSERT_OK(err, "bpf_prog_attach_opts-child"))
+ goto close_skel;
+
+ opts.flags = BPF_F_ALLOW_MULTI | BPF_F_PRIO_TOPDOWN;
+ prog = skel->progs.child_2;
+ prog_c2_fd = bpf_program__fd(prog);
+ prog_c2_atype = bpf_program__expected_attach_type(prog);
+ err = bpf_prog_attach_opts(prog_c2_fd, cg_child, prog_c2_atype, &opts);
+ if (!ASSERT_OK(err, "bpf_prog_attach_opts-child_2"))
+ goto detach_child;
+
+ optlen = 1;
+ err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
+ if (!ASSERT_OK(err, "getsockopt"))
+ goto detach_child_2;
+
+ result = skel->bss->result;
+ if (all_topdown)
+ ASSERT_TRUE(result[0] == 1 && result[1] == 2, "child only");
+ else
+ ASSERT_TRUE(result[0] == 2 && result[1] == 1, "child only");
+
+ skel->bss->idx = 0;
+ memset(result, 0, 4);
+
+ opts.flags = BPF_F_ALLOW_MULTI;
+ if (all_topdown)
+ opts.flags |= BPF_F_PRIO_TOPDOWN;
+ prog = skel->progs.parent;
+ prog_p_fd = bpf_program__fd(prog);
+ prog_p_atype = bpf_program__expected_attach_type(prog);
+ err = bpf_prog_attach_opts(prog_p_fd, cg_parent, prog_p_atype, &opts);
+ if (!ASSERT_OK(err, "bpf_prog_attach_opts-parent"))
+ goto detach_child_2;
+
+ opts.flags = BPF_F_ALLOW_MULTI | BPF_F_PRIO_TOPDOWN;
+ prog = skel->progs.parent_2;
+ prog_p2_fd = bpf_program__fd(prog);
+ prog_p2_atype = bpf_program__expected_attach_type(prog);
+ err = bpf_prog_attach_opts(prog_p2_fd, cg_parent, prog_p2_atype, &opts);
+ if (!ASSERT_OK(err, "bpf_prog_attach_opts-parent_2"))
+ goto detach_parent;
+
+ err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
+ if (!ASSERT_OK(err, "getsockopt"))
+ goto detach_parent_2;
+
+ if (all_topdown)
+ ASSERT_TRUE(result[0] == 3 && result[1] == 4 && result[2] == 1 && result[3] == 2,
+ "parent and child");
+ else
+ ASSERT_TRUE(result[0] == 4 && result[1] == 2 && result[2] == 1 && result[3] == 3,
+ "parent and child");
+
+detach_parent_2:
+ ASSERT_OK(bpf_prog_detach2(prog_p2_fd, cg_parent, prog_p2_atype),
+ "bpf_prog_detach2-parent_2");
+detach_parent:
+ ASSERT_OK(bpf_prog_detach2(prog_p_fd, cg_parent, prog_p_atype),
+ "bpf_prog_detach2-parent");
+detach_child_2:
+ ASSERT_OK(bpf_prog_detach2(prog_c2_fd, cg_child, prog_c2_atype),
+ "bpf_prog_detach2-child_2");
+detach_child:
+ ASSERT_OK(bpf_prog_detach2(prog_c_fd, cg_child, prog_c_atype),
+ "bpf_prog_detach2-child");
+close_skel:
+ cgroup_topdown__destroy(skel);
+ return err;
+}
+
+void test_cgroup_topdown(void)
+{
+ int cg_parent = -1, cg_child = -1, sock_fd = -1;
+
+ cg_parent = test__join_cgroup("/parent");
+ if (!ASSERT_GE(cg_parent, 0, "join_cgroup /parent"))
+ goto out;
+
+ cg_child = test__join_cgroup("/parent/child");
+ if (!ASSERT_GE(cg_child, 0, "join_cgroup /parent/child"))
+ goto out;
+
+ sock_fd = socket(AF_INET, SOCK_STREAM, 0);
+ if (!ASSERT_GE(sock_fd, 0, "socket"))
+ goto out;
+
+ ASSERT_OK(run_getsockopt_test(cg_parent, cg_child, sock_fd, false), "getsockopt_test_1");
+ ASSERT_OK(run_getsockopt_test(cg_parent, cg_child, sock_fd, true), "getsockopt_test_2");
+
+out:
+ close(sock_fd);
+ close(cg_child);
+ close(cg_parent);
+}
diff --git a/tools/testing/selftests/bpf/progs/cgroup_topdown.c b/tools/testing/selftests/bpf/progs/cgroup_topdown.c
new file mode 100644
index 000000000000..4ef6202baa0a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/cgroup_topdown.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+unsigned int idx;
+__u8 result[4];
+
+SEC("cgroup/getsockopt")
+int child(struct bpf_sockopt *ctx)
+{
+ if (idx < 4)
+ result[idx++] = 1;
+ return 1;
+}
+
+SEC("cgroup/getsockopt")
+int child_2(struct bpf_sockopt *ctx)
+{
+ if (idx < 4)
+ result[idx++] = 2;
+ return 1;
+}
+
+SEC("cgroup/getsockopt")
+int parent(struct bpf_sockopt *ctx)
+{
+ if (idx < 4)
+ result[idx++] = 3;
+ return 1;
+}
+
+SEC("cgroup/getsockopt")
+int parent_2(struct bpf_sockopt *ctx)
+{
+ if (idx < 4)
+ result[idx++] = 4;
+ return 1;
+}
--
2.43.5
