tools/testing/selftests/bpf/prog_tests/skb_ctx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3
   4 void test_skb_ctx(void)
   5 {
   6         struct __sk_buff skb = {
   7                 .cb[0] = 1,
   8                 .cb[1] = 2,
   9                 .cb[2] = 3,
  10                 .cb[3] = 4,
  11                 .cb[4] = 5,
  12                 .priority = 6,
  13         };
  14         struct bpf_prog_test_run_attr tattr = {
  15                 .data_in = &pkt_v4,
  16                 .data_size_in = sizeof(pkt_v4),
  17                 .ctx_in = &skb,
  18                 .ctx_size_in = sizeof(skb),
  19                 .ctx_out = &skb,
  20                 .ctx_size_out = sizeof(skb),
  21         };
  22         struct bpf_object *obj;
  23         int err;
  24         int i;
  25
  26         err = bpf_prog_load("./test_skb_ctx.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
  27                             &tattr.prog_fd);
  28         if (CHECK_ATTR(err, "load", "err %d errno %d\n", err, errno))
  29                 return;
  30
  31         /* ctx_in != NULL, ctx_size_in == 0 */
  32
  33         tattr.ctx_size_in = 0;
  34         err = bpf_prog_test_run_xattr(&tattr);
  35         CHECK_ATTR(err == 0, "ctx_size_in", "err %d errno %d\n", err, errno);
  36         tattr.ctx_size_in = sizeof(skb);
  37
  38         /* ctx_out != NULL, ctx_size_out == 0 */
  39
  40         tattr.ctx_size_out = 0;
  41         err = bpf_prog_test_run_xattr(&tattr);
  42         CHECK_ATTR(err == 0, "ctx_size_out", "err %d errno %d\n", err, errno);
  43         tattr.ctx_size_out = sizeof(skb);
  44
  45         /* non-zero [len, tc_index] fields should be rejected*/
  46
  47         skb.len = 1;
  48         err = bpf_prog_test_run_xattr(&tattr);
  49         CHECK_ATTR(err == 0, "len", "err %d errno %d\n", err, errno);
  50         skb.len = 0;
  51
  52         skb.tc_index = 1;
  53         err = bpf_prog_test_run_xattr(&tattr);
  54         CHECK_ATTR(err == 0, "tc_index", "err %d errno %d\n", err, errno);
  55         skb.tc_index = 0;
  56
  57         /* non-zero [hash, sk] fields should be rejected */
  58
  59         skb.hash = 1;
  60         err = bpf_prog_test_run_xattr(&tattr);
  61         CHECK_ATTR(err == 0, "hash", "err %d errno %d\n", err, errno);
  62         skb.hash = 0;
  63
  64         skb.sk = (struct bpf_sock *)1;
  65         err = bpf_prog_test_run_xattr(&tattr);
  66         CHECK_ATTR(err == 0, "sk", "err %d errno %d\n", err, errno);
  67         skb.sk = 0;
  68
  69         err = bpf_prog_test_run_xattr(&tattr);
  70         CHECK_ATTR(err != 0 || tattr.retval,
  71                    "run",
  72                    "err %d errno %d retval %d\n",
  73                    err, errno, tattr.retval);
  74
  75         CHECK_ATTR(tattr.ctx_size_out != sizeof(skb),
  76                    "ctx_size_out",
  77                    "incorrect output size, want %lu have %u\n",
  78                    sizeof(skb), tattr.ctx_size_out);
  79
  80         for (i = 0; i < 5; i++)
  81                 CHECK_ATTR(skb.cb[i] != i + 2,
  82                            "ctx_out_cb",
  83                            "skb->cb[i] == %d, expected %d\n",
  84                            skb.cb[i], i + 2);
  85         CHECK_ATTR(skb.priority != 7,
  86                    "ctx_out_priority",
  87                    "skb->priority == %d, expected %d\n",
  88                    skb.priority, 7);
  89 }