1 files changed, 91 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
new file mode 100644
index 000000000..33f950e2d
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <network_helpers.h>
+
+void test_skb_ctx(void)
+{
+	struct __sk_buff skb = {
+		.cb[0] = 1,
+		.cb[1] = 2,
+		.cb[2] = 3,
+		.cb[3] = 4,
+		.cb[4] = 5,
+		.priority = 6,
+		.ingress_ifindex = 11,
+		.ifindex = 1,
+		.tstamp = 7,
+		.wire_len = 100,
+		.gso_segs = 8,
+		.mark = 9,
+		.gso_size = 10,
+		.hwtstamp = 11,
+	};
+	LIBBPF_OPTS(bpf_test_run_opts, tattr,
+		.data_in = &pkt_v4,
+		.data_size_in = sizeof(pkt_v4),
+		.ctx_in = &skb,
+		.ctx_size_in = sizeof(skb),
+		.ctx_out = &skb,
+		.ctx_size_out = sizeof(skb),
+	);
+	struct bpf_object *obj;
+	int err, prog_fd, i;
+
+	err = bpf_prog_test_load("./test_skb_ctx.bpf.o", BPF_PROG_TYPE_SCHED_CLS,
+				 &obj, &prog_fd);
+	if (!ASSERT_OK(err, "load"))
+		return;
+
+	/* ctx_in != NULL, ctx_size_in == 0 */
+
+	tattr.ctx_size_in = 0;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "ctx_size_in");
+	tattr.ctx_size_in = sizeof(skb);
+
+	/* ctx_out != NULL, ctx_size_out == 0 */
+
+	tattr.ctx_size_out = 0;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "ctx_size_out");
+	tattr.ctx_size_out = sizeof(skb);
+
+	/* non-zero [len, tc_index] fields should be rejected*/
+
+	skb.len = 1;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "len");
+	skb.len = 0;
+
+	skb.tc_index = 1;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "tc_index");
+	skb.tc_index = 0;
+
+	/* non-zero [hash, sk] fields should be rejected */
+
+	skb.hash = 1;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "hash");
+	skb.hash = 0;
+
+	skb.sk = (struct bpf_sock *)1;
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_NEQ(err, 0, "sk");
+	skb.sk = 0;
+
+	err = bpf_prog_test_run_opts(prog_fd, &tattr);
+	ASSERT_OK(err, "test_run");
+	ASSERT_OK(tattr.retval, "test_run retval");
+	ASSERT_EQ(tattr.ctx_size_out, sizeof(skb), "ctx_size_out");
+
+	for (i = 0; i < 5; i++)
+		ASSERT_EQ(skb.cb[i], i + 2, "ctx_out_cb");
+	ASSERT_EQ(skb.priority, 7, "ctx_out_priority");
+	ASSERT_EQ(skb.ifindex, 1, "ctx_out_ifindex");
+	ASSERT_EQ(skb.ingress_ifindex, 11, "ctx_out_ingress_ifindex");
+	ASSERT_EQ(skb.tstamp, 8, "ctx_out_tstamp");
+	ASSERT_EQ(skb.mark, 10, "ctx_out_mark");
+
+	bpf_object__close(obj);
+}