[PATCH bpf-next 2/7] selftests/bpf: Add bpf_program__attach_netfilter helper test

Daniel Xu
2023-06-26T23:02:40Z

Call bpf_program__attach_netfilter() with different
protocol/hook/priority combinations.

Test fails if supposedly-illegal attachments work
(e.g., bogus protocol family, illegal priority and so on)
or if a should-work attachment fails.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
---
.../bpf/prog_tests/netfilter_basic.c | 78 +++++++++++++++++++
.../bpf/progs/test_netfilter_link_attach.c | 14 ++++
2 files changed, 92 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/netfilter_basic.c
create mode 100644 tools/testing/selftests/bpf/progs/test_netfilter_link_attach.c

diff --git a/tools/testing/selftests/bpf/prog_tests/netfilter_basic.c b/tools/testing/selftests/bpf/prog_tests/netfilter_basic.c
new file mode 100644
index 000000000000..357353fee19d
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/netfilter_basic.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <netinet/in.h>
+#include <linux/netfilter.h>
+
+#include "test_progs.h"
+#include "test_netfilter_link_attach.skel.h"
+
+struct nf_hook_options {
+ __u32 pf;
+ __u32 hooknum;
+ __s32 priority;
+ __u32 flags;
+
+ bool expect_success;
+};
+
+struct nf_hook_options nf_hook_attach_tests[] = {
+ { },
+ { .pf = NFPROTO_NUMPROTO, },
+ { .pf = NFPROTO_IPV4, .hooknum = 42, },
+ { .pf = NFPROTO_IPV4, .priority = INT_MIN },
+ { .pf = NFPROTO_IPV4, .priority = INT_MAX },
+ { .pf = NFPROTO_IPV4, .flags = UINT_MAX },
+
+ { .pf = NFPROTO_INET, .priority = 1, },
+
+ { .pf = NFPROTO_IPV4, .priority = -10000, .expect_success = true },
+ { .pf = NFPROTO_IPV6, .priority = 10001, .expect_success = true },
+};
+
+void test_netfilter_basic(void)
+{
+ struct test_netfilter_link_attach *skel;
+ LIBBPF_OPTS(bpf_netfilter_opts, opts);
+ struct bpf_program *prog;
+ int i;
+
+ skel = test_netfilter_link_attach__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "test_netfilter_link_attach__open_and_load"))
+ goto out;
+
+ prog = skel->progs.nf_link_attach_test;
+
+ for (i = 0; i < ARRAY_SIZE(nf_hook_attach_tests); i++) {
+ struct bpf_link *link;
+
+#define X(opts, m, i) opts.m = nf_hook_attach_tests[(i)].m
+ X(opts, pf, i);
+ X(opts, hooknum, i);
+ X(opts, priority, i);
+ X(opts, flags, i);
+#undef X
+ link = bpf_program__attach_netfilter(prog, &opts);
+ if (nf_hook_attach_tests[i].expect_success) {
+ struct bpf_link *link2;
+
+ if (!ASSERT_OK_PTR(link, "program attach successful"))
+ continue;
+
+ link2 = bpf_program__attach_netfilter(prog, &opts);
+ ASSERT_ERR_PTR(link2, "attach program with same pf/hook/priority");
+
+ if (!ASSERT_OK(bpf_link__destroy(link), "link destroy"))
+ break;
+
+ link2 = bpf_program__attach_netfilter(prog, &opts);
+ if (!ASSERT_OK_PTR(link2, "program reattach successful"))
+ continue;
+ if (!ASSERT_OK(bpf_link__destroy(link2), "link destroy"))
+ break;
+ } else {
+ ASSERT_ERR_PTR(link, "program load failure");
+ }
+ }
+out:
+ test_netfilter_link_attach__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_netfilter_link_attach.c b/tools/testing/selftests/bpf/progs/test_netfilter_link_attach.c
new file mode 100644
index 000000000000..03a475160abe
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_netfilter_link_attach.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+#define NF_ACCEPT 1
+
+SEC("netfilter")
+int nf_link_attach_test(struct bpf_nf_ctx *ctx)
+{
+ return NF_ACCEPT;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.40.1