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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3
   4 struct meta {
   5         int ifindex;
   6         __u32 cb32_0;
   7         __u8 cb8_0;
   8 };
   9
  10 static union {
  11         __u32 cb32[5];
  12         __u8 cb8[20];
  13 } cb = {
  14         .cb32[0] = 0x81828384,
  15 };
  16
  17 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
  18 {
  19         struct meta *meta = (struct meta *)data;
  20         struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
  21         int duration = 0;
  22
  23         if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
  24                   size, 72 + sizeof(*meta)))
  25                 return;
  26         if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
  27                   "meta->ifindex = %d\n", meta->ifindex))
  28                 /* spurious kfree_skb not on loopback device */
  29                 return;
  30         if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
  31                   meta->cb8_0, cb.cb8[0]))
  32                 return;
  33         if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
  34                   "cb32_0 %x != %x\n",
  35                   meta->cb32_0, cb.cb32[0]))
  36                 return;
  37         if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
  38                   "h_proto %x\n", pkt_v6->eth.h_proto))
  39                 return;
  40         if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
  41                   "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
  42                 return;
  43         if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
  44                   "tcp.doff %x\n", pkt_v6->tcp.doff))
  45                 return;
  46
  47         *(bool *)ctx = true;
  48 }
  49
  50 void test_kfree_skb(void)
  51 {
  52         struct __sk_buff skb = {};
  53         struct bpf_prog_test_run_attr tattr = {
  54                 .data_in = &pkt_v6,
  55                 .data_size_in = sizeof(pkt_v6),
  56                 .ctx_in = &skb,
  57                 .ctx_size_in = sizeof(skb),
  58         };
  59         struct bpf_prog_load_attr attr = {
  60                 .file = "./kfree_skb.o",
  61         };
  62
  63         struct bpf_link *link = NULL, *link_fentry = NULL, *link_fexit = NULL;
  64         struct bpf_map *perf_buf_map, *global_data;
  65         struct bpf_program *prog, *fentry, *fexit;
  66         struct bpf_object *obj, *obj2 = NULL;
  67         struct perf_buffer_opts pb_opts = {};
  68         struct perf_buffer *pb = NULL;
  69         int err, kfree_skb_fd;
  70         bool passed = false;
  71         __u32 duration = 0;
  72         const int zero = 0;
  73         bool test_ok[2];
  74
  75         err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
  76                             &obj, &tattr.prog_fd);
  77         if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
  78                 return;
  79
  80         err = bpf_prog_load_xattr(&attr, &obj2, &kfree_skb_fd);
  81         if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
  82                 goto close_prog;
  83
  84         prog = bpf_object__find_program_by_title(obj2, "tp_btf/kfree_skb");
  85         if (CHECK(!prog, "find_prog", "prog kfree_skb not found\n"))
  86                 goto close_prog;
  87         fentry = bpf_object__find_program_by_title(obj2, "fentry/eth_type_trans");
  88         if (CHECK(!fentry, "find_prog", "prog eth_type_trans not found\n"))
  89                 goto close_prog;
  90         fexit = bpf_object__find_program_by_title(obj2, "fexit/eth_type_trans");
  91         if (CHECK(!fexit, "find_prog", "prog eth_type_trans not found\n"))
  92                 goto close_prog;
  93
  94         global_data = bpf_object__find_map_by_name(obj2, "kfree_sk.bss");
  95         if (CHECK(!global_data, "find global data", "not found\n"))
  96                 goto close_prog;
  97
  98         link = bpf_program__attach_raw_tracepoint(prog, NULL);
  99         if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
 100                 goto close_prog;
 101         link_fentry = bpf_program__attach_trace(fentry);
 102         if (CHECK(IS_ERR(link_fentry), "attach fentry", "err %ld\n",
 103                   PTR_ERR(link_fentry)))
 104                 goto close_prog;
 105         link_fexit = bpf_program__attach_trace(fexit);
 106         if (CHECK(IS_ERR(link_fexit), "attach fexit", "err %ld\n",
 107                   PTR_ERR(link_fexit)))
 108                 goto close_prog;
 109
 110         perf_buf_map = bpf_object__find_map_by_name(obj2, "perf_buf_map");
 111         if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
 112                 goto close_prog;
 113
 114         /* set up perf buffer */
 115         pb_opts.sample_cb = on_sample;
 116         pb_opts.ctx = &passed;
 117         pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
 118         if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
 119                 goto close_prog;
 120
 121         memcpy(skb.cb, &cb, sizeof(cb));
 122         err = bpf_prog_test_run_xattr(&tattr);
 123         duration = tattr.duration;
 124         CHECK(err || tattr.retval, "ipv6",
 125               "err %d errno %d retval %d duration %d\n",
 126               err, errno, tattr.retval, duration);
 127
 128         /* read perf buffer */
 129         err = perf_buffer__poll(pb, 100);
 130         if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
 131                 goto close_prog;
 132
 133         /* make sure kfree_skb program was triggered
 134          * and it sent expected skb into ring buffer
 135          */
 136         CHECK_FAIL(!passed);
 137
 138         err = bpf_map_lookup_elem(bpf_map__fd(global_data), &zero, test_ok);
 139         if (CHECK(err, "get_result",
 140                   "failed to get output data: %d\n", err))
 141                 goto close_prog;
 142
 143         CHECK_FAIL(!test_ok[0] || !test_ok[1]);
 144 close_prog:
 145         perf_buffer__free(pb);
 146         if (!IS_ERR_OR_NULL(link))
 147                 bpf_link__destroy(link);
 148         if (!IS_ERR_OR_NULL(link_fentry))
 149                 bpf_link__destroy(link_fentry);
 150         if (!IS_ERR_OR_NULL(link_fexit))
 151                 bpf_link__destroy(link_fexit);
 152         bpf_object__close(obj);
 153         bpf_object__close(obj2);
 154 }