[PATCH bpf-next v4 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>
---
 .../testing/selftests/bpf/prog_tests/tc_bpf.c | 204 ++++++++++++++++++
 .../testing/selftests/bpf/progs/test_tc_bpf.c |  12 ++
 2 files changed, 216 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/tc_bpf.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_tc_bpf.c

diff --git a/tools/testing/selftests/bpf/prog_tests/tc_bpf.c b/tools/testing/selftests/bpf/prog_tests/tc_bpf.c
new file mode 100644
index 000000000000..47505b92e50a
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/tc_bpf.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+#include <linux/pkt_cls.h>
+
+#include "test_tc_bpf.skel.h"
+
+#define LO_IFINDEX 1
+
+static const __u32 tcm_parent[2] = {
+	[BPF_TC_INGRESS] = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS),
+	[BPF_TC_EGRESS] = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS),
+};
+
+static int test_tc_internal(struct bpf_tc_ctx *ctx, int fd,
+			    enum bpf_tc_attach_point parent)
+{
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 10);
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	int ret;
+
+	ret = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+	if (!ASSERT_EQ(ret, 0, "bpf_obj_get_info_by_fd"))
+		return ret;
+
+	ret = bpf_tc_attach(ctx, fd, &opts);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach"))
+		return ret;
+
+	if (!ASSERT_EQ(opts.handle, 1, "handle set") ||
+	    !ASSERT_EQ(opts.priority, 10, "priority set") ||
+	    !ASSERT_EQ(opts.parent, tcm_parent[parent], "parent set") ||
+	    !ASSERT_NEQ(opts.prog_id, 0, "prog_id set"))
+		goto end;
+
+	opts.prog_id = 0;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_query"))
+		goto end;
+
+	if (!ASSERT_NEQ(opts.prog_id, 0, "prog_id set") ||
+	    !ASSERT_EQ(info.id, opts.prog_id, "prog_id matching"))
+		goto end;
+
+	/* Atomic replace */
+	opts.replace = true;
+	opts.parent = opts.prog_id = 0;
+	ret = bpf_tc_attach(ctx, fd, &opts);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_attach replace mode"))
+		return ret;
+	opts.replace = false;
+
+end:
+	opts.prog_id = 0;
+	ret = bpf_tc_detach(ctx, &opts);
+	ASSERT_EQ(ret, 0, "bpf_tc_detach");
+	return ret;
+}
+
+int test_tc_invalid(struct bpf_tc_ctx *ctx, int fd)
+{
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 10,
+			    .parent = tcm_parent[BPF_TC_INGRESS]);
+	struct bpf_tc_ctx *inv_ctx;
+	int ret, saved_errno;
+
+	inv_ctx = bpf_tc_ctx_init(0, BPF_TC_INGRESS, NULL);
+	saved_errno = errno;
+	if (!ASSERT_EQ(inv_ctx, NULL, "bpf_tc_ctx_init invalid ifindex = 0"))
+		return -EINVAL;
+
+	ASSERT_EQ(saved_errno, EINVAL, "errno");
+
+	inv_ctx = bpf_tc_ctx_init(LO_IFINDEX, 0xdeadc0de, NULL);
+	saved_errno = errno;
+	if (!ASSERT_EQ(inv_ctx, NULL,
+		       "bpf_tc_ctx_init invalid parent >= _BPF_TC_PARENT_MAX"))
+		return -EINVAL;
+
+	ASSERT_EQ(saved_errno, EINVAL, "errno");
+
+	ret = bpf_tc_ctx_destroy(NULL);
+	if (!ASSERT_EQ(ret, 0, "bpf_tc_ctx_destroy ctx = NULL"))
+		return -EINVAL;
+
+	ret = bpf_tc_detach(NULL, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid ctx = NULL"))
+		return -EINVAL;
+
+	ret = bpf_tc_detach(ctx, NULL);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid opts = NULL"))
+		return -EINVAL;
+
+	ret = bpf_tc_query(NULL, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid ctx = NULL"))
+		return -EINVAL;
+
+	ret = bpf_tc_query(ctx, NULL);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid opts = NULL"))
+		return -EINVAL;
+
+	opts.replace = true;
+	ret = bpf_tc_detach(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid replace set"))
+		return -EINVAL;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid replace set"))
+		return -EINVAL;
+	opts.replace = false;
+
+	opts.prog_id = 42;
+	ret = bpf_tc_detach(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid prog_id set"))
+		return -EINVAL;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid prog_id set"))
+		return -EINVAL;
+	opts.prog_id = 0;
+
+	opts.handle = 0;
+	ret = bpf_tc_detach(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid handle unset"))
+		return -EINVAL;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid handle unset"))
+		return -EINVAL;
+	opts.handle = 1;
+
+	opts.priority = 0;
+	ret = bpf_tc_detach(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid priority unset"))
+		return -EINVAL;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid priority unset"))
+		return -EINVAL;
+	opts.priority = 10;
+
+	opts.parent = 0;
+	ret = bpf_tc_detach(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_detach invalid parent unset"))
+		return -EINVAL;
+	ret = bpf_tc_query(ctx, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_query invalid parent unset"))
+		return -EINVAL;
+
+	ret = bpf_tc_attach(NULL, fd, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_attach invalid ctx = NULL"))
+		return -EINVAL;
+
+	ret = bpf_tc_attach(ctx, -1, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_attach invalid fd < 0"))
+		return -EINVAL;
+
+	ret = bpf_tc_attach(ctx, fd, NULL);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_attach invalid opts = NULL"))
+		return -EINVAL;
+
+	opts.prog_id = 42;
+	ret = bpf_tc_attach(ctx, fd, &opts);
+	if (!ASSERT_EQ(ret, -EINVAL, "bpf_tc_attach invalid prog_id set"))
+		return -EINVAL;
+	opts.prog_id = 0;
+
+	return 0;
+}
+
+void test_tc_bpf(void)
+{
+	struct bpf_tc_ctx *ctx_ing = NULL, *ctx_eg = NULL;
+	struct test_tc_bpf *skel = NULL;
+	int cls_fd, ret;
+
+	skel = test_tc_bpf__open_and_load();
+	if (!ASSERT_NEQ(skel, NULL, "test_tc_bpf skeleton"))
+		goto end;
+
+	cls_fd = bpf_program__fd(skel->progs.cls);
+
+	ctx_ing = bpf_tc_ctx_init(LO_IFINDEX, BPF_TC_INGRESS, NULL);
+	if (!ASSERT_NEQ(ctx_ing, NULL, "bpf_tc_ctx_init(BPF_TC_INGRESS)"))
+		goto end;
+
+	ctx_eg = bpf_tc_ctx_init(LO_IFINDEX, BPF_TC_EGRESS, NULL);
+	if (!ASSERT_NEQ(ctx_eg, NULL, "bpf_tc_ctx_init(BPF_TC_EGRESS)"))
+		goto end;
+
+	ret = test_tc_internal(ctx_ing, cls_fd, BPF_TC_INGRESS);
+	if (!ASSERT_EQ(ret, 0, "test_tc_internal ingress"))
+		goto end;
+
+	ret = test_tc_internal(ctx_eg, cls_fd, BPF_TC_EGRESS);
+	if (!ASSERT_EQ(ret, 0, "test_tc_internal egress"))
+		goto end;
+
+	ret = test_tc_invalid(ctx_ing, cls_fd);
+	if (!ASSERT_EQ(ret, 0, "test_tc_invalid"))
+		goto end;
+
+end:
+	bpf_tc_ctx_destroy(ctx_eg);
+	bpf_tc_ctx_destroy(ctx_ing);
+	test_tc_bpf__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_tc_bpf.c b/tools/testing/selftests/bpf/progs/test_tc_bpf.c
new file mode 100644
index 000000000000..18a3a7ed924a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_tc_bpf.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