Thread (31 messages) 31 messages, 6 authors, 2021-12-30

[PATCH v20 bpf-next 21/23] bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest

From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2021-12-10 19:16:51
Also in: bpf
Subsystem: bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest, xdp (express data path) · Maintainers: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend

Introduce kernel selftest for new bpf_xdp_{load,store}_bytes helpers.
and bpf_xdp_pointer/bpf_xdp_copy_buf utility routines.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 .../bpf/prog_tests/xdp_adjust_frags.c         | 103 ++++++++++++++++++
 .../bpf/progs/test_xdp_update_frags.c         |  42 +++++++
 2 files changed, 145 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
new file mode 100644
index 000000000000..4b0d04fb1041
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <network_helpers.h>
+
+void test_xdp_update_frags(void)
+{
+	const char *file = "./test_xdp_update_frags.o";
+	__u32 duration, retval, size;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int err, prog_fd;
+	__u32 *offset;
+	__u8 *buf;
+
+	obj = bpf_object__open(file);
+	if (libbpf_get_error(obj))
+		return;
+
+	prog = bpf_object__next_program(obj, NULL);
+	if (bpf_object__load(obj))
+		return;
+
+	prog_fd = bpf_program__fd(prog);
+
+	buf = malloc(128);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		goto out;
+
+	memset(buf, 0, 128);
+	offset = (__u32 *)buf;
+	*offset = 16;
+	buf[*offset] = 0xaa;		/* marker at offset 16 (head) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 31 (head) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 128,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[16,31]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS || buf[16] != 0xbb || buf[31] != 0xbb,
+	      "128b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	free(buf);
+
+	buf = malloc(9000);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		goto out;
+
+	memset(buf, 0, 9000);
+	offset = (__u32 *)buf;
+	*offset = 5000;
+	buf[*offset] = 0xaa;		/* marker at offset 5000 (frag0) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 5015 (frag0) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[5000,5015]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS ||
+	      buf[5000] != 0xbb || buf[5015] != 0xbb,
+	      "9000b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	memset(buf, 0, 9000);
+	offset = (__u32 *)buf;
+	*offset = 3510;
+	buf[*offset] = 0xaa;		/* marker at offset 3510 (head) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 3525 (frag0) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[3510,3525]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS ||
+	      buf[3510] != 0xbb || buf[3525] != 0xbb,
+	      "9000b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	memset(buf, 0, 9000);
+	offset = (__u32 *)buf;
+	*offset = 7606;
+	buf[*offset] = 0xaa;		/* marker at offset 7606 (frag0) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 7621 (frag1) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[7606,7621]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS ||
+	      buf[7606] != 0xbb || buf[7621] != 0xbb,
+	      "9000b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	free(buf);
+out:
+	bpf_object__close(obj);
+}
+
+void test_xdp_adjust_frags(void)
+{
+	if (test__start_subtest("xdp_adjust_frags"))
+		test_xdp_update_frags();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
new file mode 100644
index 000000000000..5801f05219db
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <bpf/bpf_helpers.h>
+
+int _version SEC("version") = 1;
+
+SEC("xdp_mb/xdp_adjust_frags")
+int _xdp_adjust_frags(struct xdp_md *xdp)
+{
+	__u8 *data_end = (void *)(long)xdp->data_end;
+	__u8 *data = (void *)(long)xdp->data;
+	__u8 val[16] = {};
+	__u32 offset;
+	int err;
+
+	if (data + sizeof(__u32) > data_end)
+		return XDP_DROP;
+
+	offset = *(__u32 *)data;
+	err = bpf_xdp_load_bytes(xdp, offset, val, sizeof(val));
+	if (err < 0)
+		return XDP_DROP;
+
+	if (val[0] != 0xaa || val[15] != 0xaa) /* marker */
+		return XDP_DROP;
+
+	val[0] = 0xbb; /* update the marker */
+	val[15] = 0xbb;
+	err = bpf_xdp_store_bytes(xdp, offset, val, sizeof(val));
+	if (err < 0)
+		return XDP_DROP;
+
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.33.1
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