[PATCH bpf-next v3 3/3] libbpf: add selftests for TC-BPF API

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

This adds some basic tests for the low level bpf_tc_* API.

Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 .../selftests/bpf/prog_tests/test_tc_bpf.c    | 169 ++++++++++++++++++
 .../selftests/bpf/progs/test_tc_bpf_kern.c    |  12 ++
 2 files changed, 181 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c

diff --git a/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c b/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
new file mode 100644
index 000000000000..563a3944553c
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <linux/err.h>
+#include <linux/limits.h>
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <test_progs.h>
+#include <linux/if_ether.h>
+
+#define LO_IFINDEX 1
+
+static int test_tc_internal(int fd, __u32 parent_id)
+{
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 10,
+			    .class_id = TC_H_MAKE(1UL << 16, 1));
+	struct bpf_tc_attach_id id = {};
+	struct bpf_tc_info info = {};
+	int ret;
+
+	ret = bpf_tc_attach(fd, LO_IFINDEX, parent_id, &opts, &id);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach"))
+		return ret;
+
+	ret = bpf_tc_get_info(LO_IFINDEX, parent_id, &id, &info);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_get_info"))
+		goto end;
+
+	if (!ASSERT_EQ(info.id.handle, id.handle, "handle mismatch") ||
+	    !ASSERT_EQ(info.id.priority, id.priority, "priority mismatch") ||
+	    !ASSERT_EQ(info.id.handle, 1, "handle incorrect") ||
+	    !ASSERT_EQ(info.chain_index, 0, "chain_index incorrect") ||
+	    !ASSERT_EQ(info.id.priority, 10, "priority incorrect") ||
+	    !ASSERT_EQ(info.class_id, TC_H_MAKE(1UL << 16, 1),
+		       "class_id incorrect") ||
+	    !ASSERT_EQ(info.protocol, ETH_P_ALL, "protocol incorrect"))
+		goto end;
+
+	opts.replace = true;
+	ret = bpf_tc_attach(fd, LO_IFINDEX, parent_id, &opts, &id);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach in replace mode"))
+		return ret;
+
+	/* Demonstrate changing attributes */
+	opts.class_id = TC_H_MAKE(1UL << 16, 2);
+
+	ret = bpf_tc_attach(fd, LO_IFINDEX, parent_id, &opts, &id);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc attach in replace mode"))
+		goto end;
+
+	ret = bpf_tc_get_info(LO_IFINDEX, parent_id, &id, &info);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_get_info"))
+		goto end;
+
+	if (!ASSERT_EQ(info.class_id, TC_H_MAKE(1UL << 16, 2),
+		       "class_id incorrect after replace"))
+		goto end;
+	if (!ASSERT_EQ(info.bpf_flags & TCA_BPF_FLAG_ACT_DIRECT, 1,
+		       "direct action mode not set"))
+		goto end;
+
+end:
+	ret = bpf_tc_detach(LO_IFINDEX, parent_id, &id);
+	ASSERT_EQ(ret, 0, "detach failed");
+	return ret;
+}
+
+int test_tc_info(int fd)
+{
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 10,
+			    .class_id = TC_H_MAKE(1UL << 16, 1));
+	struct bpf_tc_attach_id id = {}, old;
+	struct bpf_tc_info info = {};
+	int ret;
+
+	ret = bpf_tc_attach(fd, LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &opts, &id);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach"))
+		return ret;
+	old = id;
+
+	ret = bpf_tc_get_info(LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &id, &info);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_get_info"))
+		goto end_old;
+
+	if (!ASSERT_EQ(info.id.handle, id.handle, "handle mismatch") ||
+	    !ASSERT_EQ(info.id.priority, id.priority, "priority mismatch") ||
+	    !ASSERT_EQ(info.id.handle, 1, "handle incorrect") ||
+	    !ASSERT_EQ(info.chain_index, 0, "chain_index incorrect") ||
+	    !ASSERT_EQ(info.id.priority, 10, "priority incorrect") ||
+	    !ASSERT_EQ(info.class_id, TC_H_MAKE(1UL << 16, 1),
+		       "class_id incorrect") ||
+	    !ASSERT_EQ(info.protocol, ETH_P_ALL, "protocol incorrect"))
+		goto end_old;
+
+	/* choose a priority */
+	opts.priority = 0;
+	ret = bpf_tc_attach(fd, LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &opts, &id);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach"))
+		goto end_old;
+
+	ret = bpf_tc_get_info(LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &id, &info);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_get_info"))
+		goto end;
+
+	if (!ASSERT_NEQ(id.priority, old.priority, "filter priority mismatch"))
+		goto end;
+	if (!ASSERT_EQ(info.id.priority, id.priority, "priority mismatch"))
+		goto end;
+
+end:
+	ret = bpf_tc_detach(LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &id);
+	ASSERT_EQ(ret, 0, "detach failed");
+end_old:
+	ret = bpf_tc_detach(LO_IFINDEX, BPF_TC_CLSACT_INGRESS, &old);
+	ASSERT_EQ(ret, 0, "detach failed");
+	return ret;
+}
+
+void test_test_tc_bpf(void)
+{
+	const char *file = "./test_tc_bpf_kern.o";
+	struct bpf_program *clsp;
+	struct bpf_object *obj;
+	int cls_fd, ret;
+
+	obj = bpf_object__open(file);
+	if (!ASSERT_OK_PTR(obj, "bpf_object__open"))
+		return;
+
+	clsp = bpf_object__find_program_by_title(obj, "classifier");
+	if (!ASSERT_OK_PTR(clsp, "bpf_object__find_program_by_title"))
+		goto end;
+
+	ret = bpf_object__load(obj);
+	if (!ASSERT_EQ(ret, 0, "bpf_object__load"))
+		goto end;
+
+	cls_fd = bpf_program__fd(clsp);
+
+	system("tc qdisc del dev lo clsact");
+
+	ret = test_tc_internal(cls_fd, BPF_TC_CLSACT_INGRESS);
+	if (!ASSERT_EQ(ret, 0, "test_tc_internal INGRESS"))
+		goto end;
+
+	if (!ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
+		       "clsact qdisc delete failed"))
+		goto end;
+
+	ret = test_tc_info(cls_fd);
+	if (!ASSERT_EQ(ret, 0, "test_tc_info"))
+		goto end;
+
+	if (!ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
+		       "clsact qdisc delete failed"))
+		goto end;
+
+	ret = test_tc_internal(cls_fd, BPF_TC_CLSACT_EGRESS);
+	if (!ASSERT_EQ(ret, 0, "test_tc_internal EGRESS"))
+		goto end;
+
+	ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
+		  "clsact qdisc delete failed");
+
+end:
+	bpf_object__close(obj);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c b/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c
new file mode 100644
index 000000000000..18a3a7ed924a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+/* Dummy prog to test TC-BPF API */
+
+SEC("classifier")
+int cls(struct __sk_buff *skb)
+{
+	return 0;
+}
-- 
2.30.2