[PATCH bpf-next 2/2] selftests/bpf: Add test for xdp_md context with LIVE_FRAMES in BPF_PROG_TEST_RUN

[KaFai Wan <kafai.wan@linux.dev>]

Add a test case uses xdp_md as context parameter for BPF_PROG_TEST_RUN
with LIVE_FRAMES flag. The test ensures that potential user-memory-access
vulnerabilities are properly prevented.

Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
---
 .../bpf/prog_tests/xdp_context_test_run.c     | 19 +++++++++++++++++++
 .../bpf/progs/test_xdp_context_test_run.c     |  6 ++++++
 2 files changed, 25 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c b/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
index ee94c281888a..0276daaae45c 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
@@ -45,6 +45,7 @@ void test_xdp_context_error(int prog_fd, struct bpf_test_run_opts opts,
 void test_xdp_context_test_run(void)
 {
 	struct test_xdp_context_test_run *skel = NULL;
+	char data_xdp[sizeof(pkt_v4) + XDP_PACKET_HEADROOM];
 	char data[sizeof(pkt_v4) + sizeof(__u32)];
 	char bad_ctx[sizeof(struct xdp_md) + 1];
 	struct xdp_md ctx_in, ctx_out;
@@ -55,6 +56,12 @@ void test_xdp_context_test_run(void)
 			    .ctx_size_out = sizeof(ctx_out),
 			    .repeat = 1,
 		);
+	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts_xdp,
+			    .data_in = &data_xdp,
+			    .data_size_in = sizeof(data_xdp),
+			    .flags = BPF_F_TEST_XDP_LIVE_FRAMES,
+			    .repeat = 1,
+		);
 	int err, prog_fd;
 
 	skel = test_xdp_context_test_run__open_and_load();
@@ -70,6 +77,18 @@ void test_xdp_context_test_run(void)
 	ASSERT_EQ(errno, E2BIG, "extradata-errno");
 	ASSERT_ERR(err, "bpf_prog_test_run(extradata)");
 
+	memset(&ctx_in, 0, sizeof(ctx_in));
+	ctx_in.data_meta = 0;
+	ctx_in.data = 0xf4;
+	ctx_in.data_end = sizeof(data_xdp);
+	opts_xdp.ctx_in = &ctx_in;
+	opts_xdp.ctx_size_in = sizeof(ctx_in);
+	*(__u32 *)(data_xdp + 0) = 0x28d6a0b5;
+	*(__u32 *)(data_xdp + 4) = 0xf273eea3;
+	*(struct ipv4_packet *)(data_xdp + ctx_in.data) = pkt_v4;
+	err = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.xdp_pass), &opts_xdp);
+	ASSERT_OK(err, "bpf_prog_test_run(valid meta)");
+
 	*(__u32 *)data = XDP_PASS;
 	*(struct ipv4_packet *)(data + sizeof(__u32)) = pkt_v4;
 	opts.ctx_in = &ctx_in;
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_context_test_run.c b/tools/testing/selftests/bpf/progs/test_xdp_context_test_run.c
index d7b88cd05afd..2166928d4680 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_context_test_run.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_context_test_run.c
@@ -17,4 +17,10 @@ int xdp_context(struct xdp_md *xdp)
 	return ret;
 }
 
+SEC("xdp")
+int xdp_pass(struct xdp_md *xdp)
+{
+	return XDP_PASS;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.43.0