[PATCH net-next v2 33/33] selftests/bpf: xdp_adjust_tail add grow tail tests

Jesper Dangaard Brouer
2020-04-30T11:23:23Z

Extend BPF selftest xdp_adjust_tail with grow tail tests, which is added
as subtest's. The first grow test stays in same form as original shrink
test. The second grow test use the newer bpf_prog_test_run_xattr() calls,
and does extra checking of data contents.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
.../selftests/bpf/prog_tests/xdp_adjust_tail.c | 116 +++++++++++++++++++-
.../bpf/progs/test_xdp_adjust_tail_grow.c | 33 ++++++
2 files changed, 144 insertions(+), 5 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
index d258f979d5ef..1498627af6e8 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
@@ -4,10 +4,10 @@
void test_xdp_adjust_tail_shrink(void)
{
const char *file = "./test_xdp_adjust_tail_shrink.o";
+ __u32 duration, retval, size, expect_sz;
struct bpf_object *obj;
- char buf[128];
- __u32 duration, retval, size;
int err, prog_fd;
+ char buf[128];

err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
if (CHECK_FAIL(err))
@@ -20,15 +20,121 @@ void test_xdp_adjust_tail_shrink(void)
"ipv4", "err %d errno %d retval %d size %d\n",
err, errno, retval, size);

+ expect_sz = sizeof(pkt_v6) - 20; /* Test shrink with 20 bytes */
err = bpf_prog_test_run(prog_fd, 1, &pkt_v6, sizeof(pkt_v6),
buf, &size, &retval, &duration);
- CHECK(err || retval != XDP_TX || size != 54,
- "ipv6", "err %d errno %d retval %d size %d\n",
+ CHECK(err || retval != XDP_TX || size != expect_sz,
+ "ipv6", "err %d errno %d retval %d size %d expect-size %d\n",
+ err, errno, retval, size, expect_sz);
+ bpf_object__close(obj);
+}
+
+void test_xdp_adjust_tail_grow(void)
+{
+ const char *file = "./test_xdp_adjust_tail_grow.o";
+ struct bpf_object *obj;
+ char buf[4096]; /* avoid segfault: large buf to hold grow results */
+ __u32 duration, retval, size, expect_sz;
+ int err, prog_fd;
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
+ buf, &size, &retval, &duration);
+ CHECK(err || retval != XDP_DROP,
+ "ipv4", "err %d errno %d retval %d size %d\n",
err, errno, retval, size);
+
+ expect_sz = sizeof(pkt_v6) + 40; /* Test grow with 40 bytes */
+ err = bpf_prog_test_run(prog_fd, 1, &pkt_v6, sizeof(pkt_v6) /* 74 */,
+ buf, &size, &retval, &duration);
+ CHECK(err || retval != XDP_TX || size != expect_sz,
+ "ipv6", "err %d errno %d retval %d size %d expect-size %d\n",
+ err, errno, retval, size, expect_sz);
+
+ bpf_object__close(obj);
+}
+
+void test_xdp_adjust_tail_grow2(void)
+{
+ const char *file = "./test_xdp_adjust_tail_grow.o";
+ char buf[4096]; /* avoid segfault: large buf to hold grow results */
+ int tailroom = 320; /* SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) */;
+ struct bpf_object *obj;
+ int err, cnt, i;
+ int max_grow;
+
+ struct bpf_prog_test_run_attr tattr = {
+ .repeat = 1,
+ .data_in = &buf,
+ .data_out = &buf,
+ .data_size_in = 0, /* Per test */
+ .data_size_out = 0, /* Per test */
+ };
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &tattr.prog_fd);
+ if (CHECK_ATTR(err, "load", "err %d errno %d\n", err, errno))
+ return;
+
+ /* Test case-64 */
+ memset(buf, 1, sizeof(buf));
+ tattr.data_size_in = 64; /* Determine test case via pkt size */
+ tattr.data_size_out = 128; /* Limit copy_size */
+ /* Kernel side alloc packet memory area that is zero init */
+ err = bpf_prog_test_run_xattr(&tattr);
+
+ CHECK_ATTR(errno != ENOSPC /* Due limit copy_size in bpf_test_finish */
+ || tattr.retval != XDP_TX
+ || tattr.data_size_out != 192, /* Expected grow size */
+ "case-64",
+ "err %d errno %d retval %d size %d\n",
+ err, errno, tattr.retval, tattr.data_size_out);
+
+ /* Extra checks for data contents */
+ CHECK_ATTR(tattr.data_size_out != 192
+ || buf[0] != 1 || buf[63] != 1 /* 0-63 memset to 1 */
+ || buf[64] != 0 || buf[127] != 0 /* 64-127 memset to 0 */
+ || buf[128] != 1 || buf[191] != 1, /*128-191 memset to 1 */
+ "case-64-data",
+ "err %d errno %d retval %d size %d\n",
+ err, errno, tattr.retval, tattr.data_size_out);
+
+ /* Test case-128 */
+ memset(buf, 2, sizeof(buf));
+ tattr.data_size_in = 128; /* Determine test case via pkt size */
+ tattr.data_size_out = sizeof(buf); /* Copy everything */
+ err = bpf_prog_test_run_xattr(&tattr);
+
+ max_grow = 4096 - XDP_PACKET_HEADROOM - tailroom; /* 3520 */
+ CHECK_ATTR(err
+ || tattr.retval != XDP_TX
+ || tattr.data_size_out != max_grow, /* Expect max grow size */
+ "case-128",
+ "err %d errno %d retval %d size %d expect-size %d\n",
+ err, errno, tattr.retval, tattr.data_size_out, max_grow);
+
+ /* Extra checks for data contents: Count grow size, will contain zeros */
+ for (i = 0, cnt = 0; i < sizeof(buf); i++) {
+ if (buf[i] == 0)
+ cnt++;
+ }
+ CHECK_ATTR((cnt != (max_grow - tattr.data_size_in)) /* Grow increase */
+ || tattr.data_size_out != max_grow, /* Total grow size */
+ "case-128-data",
+ "err %d errno %d retval %d size %d grow-size %d\n",
+ err, errno, tattr.retval, tattr.data_size_out, cnt);
+
bpf_object__close(obj);
}

void test_xdp_adjust_tail(void)
{
- test_xdp_adjust_tail_shrink();
+ if (test__start_subtest("xdp_adjust_tail_shrink"))
+ test_xdp_adjust_tail_shrink();
+ if (test__start_subtest("xdp_adjust_tail_grow"))
+ test_xdp_adjust_tail_grow();
+ if (test__start_subtest("xdp_adjust_tail_grow2"))
+ test_xdp_adjust_tail_grow2();
}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
new file mode 100644
index 000000000000..3d66599eee2e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("xdp_adjust_tail_grow")
+int _xdp_adjust_tail_grow(struct xdp_md *xdp)
+{
+ void *data_end = (void *)(long)xdp->data_end;
+ void *data = (void *)(long)xdp->data;
+ unsigned int data_len;
+ int offset = 0;
+
+ /* Data length determine test case */
+ data_len = data_end - data;
+
+ if (data_len == 54) { /* sizeof(pkt_v4) */
+ offset = 4096; /* test too large offset */
+ } else if (data_len == 74) { /* sizeof(pkt_v6) */
+ offset = 40;
+ } else if (data_len == 64) {
+ offset = 128;
+ } else if (data_len == 128) {
+ offset = 4096 - 256 - 320 - data_len; /* Max tail grow 3520 */
+ } else {
+ return XDP_ABORTED; /* No matching test */
+ }
+
+ if (bpf_xdp_adjust_tail(xdp, offset))
+ return XDP_DROP;
+ return XDP_TX;
+}
+
+char _license[] SEC("license") = "GPL";