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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3 #include <network_helpers.h>
   4
   5 struct meta {
   6         int ifindex;
   7         __u32 cb32_0;
   8         __u8 cb8_0;
   9 };
  10
  11 static union {
  12         __u32 cb32[5];
  13         __u8 cb8[20];
  14 } cb = {
  15         .cb32[0] = 0x81828384,
  16 };
  17
  18 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
  19 {
  20         struct meta *meta = (struct meta *)data;
  21         struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
  22         int duration = 0;
  23
  24         if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
  25                   size, 72 + sizeof(*meta)))
  26                 return;
  27         if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
  28                   "meta->ifindex = %d\n", meta->ifindex))
  29                 /* spurious kfree_skb not on loopback device */
  30                 return;
  31         if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
  32                   meta->cb8_0, cb.cb8[0]))
  33                 return;
  34         if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
  35                   "cb32_0 %x != %x\n",
  36                   meta->cb32_0, cb.cb32[0]))
  37                 return;
  38         if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
  39                   "h_proto %x\n", pkt_v6->eth.h_proto))
  40                 return;
  41         if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
  42                   "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
  43                 return;
  44         if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
  45                   "tcp.doff %x\n", pkt_v6->tcp.doff))
  46                 return;
  47
  48         *(bool *)ctx = true;
  49 }
  50
  51 void test_kfree_skb(void)
  52 {
  53         struct __sk_buff skb = {};
  54         struct bpf_prog_test_run_attr tattr = {
  55                 .data_in = &pkt_v6,
  56                 .data_size_in = sizeof(pkt_v6),
  57                 .ctx_in = &skb,
  58                 .ctx_size_in = sizeof(skb),
  59         };
  60         struct bpf_prog_load_attr attr = {
  61                 .file = "./kfree_skb.o",
  62         };
  63
  64         struct bpf_link *link = NULL, *link_fentry = NULL, *link_fexit = NULL;
  65         struct bpf_map *perf_buf_map, *global_data;
  66         struct bpf_program *prog, *fentry, *fexit;
  67         struct bpf_object *obj, *obj2 = NULL;
  68         struct perf_buffer_opts pb_opts = {};
  69         struct perf_buffer *pb = NULL;
  70         int err, kfree_skb_fd;
  71         bool passed = false;
  72         __u32 duration = 0;
  73         const int zero = 0;
  74         bool test_ok[2];
  75
  76         err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
  77                             &obj, &tattr.prog_fd);
  78         if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
  79                 return;
  80
  81         err = bpf_prog_load_xattr(&attr, &obj2, &kfree_skb_fd);
  82         if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
  83                 goto close_prog;
  84
  85         prog = bpf_object__find_program_by_title(obj2, "tp_btf/kfree_skb");
  86         if (CHECK(!prog, "find_prog", "prog kfree_skb not found\n"))
  87                 goto close_prog;
  88         fentry = bpf_object__find_program_by_title(obj2, "fentry/eth_type_trans");
  89         if (CHECK(!fentry, "find_prog", "prog eth_type_trans not found\n"))
  90                 goto close_prog;
  91         fexit = bpf_object__find_program_by_title(obj2, "fexit/eth_type_trans");
  92         if (CHECK(!fexit, "find_prog", "prog eth_type_trans not found\n"))
  93                 goto close_prog;
  94
  95         global_data = bpf_object__find_map_by_name(obj2, "kfree_sk.bss");
  96         if (CHECK(!global_data, "find global data", "not found\n"))
  97                 goto close_prog;
  98
  99         link = bpf_program__attach_raw_tracepoint(prog, NULL);
 100         if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
 101                 goto close_prog;
 102         link_fentry = bpf_program__attach_trace(fentry);
 103         if (CHECK(IS_ERR(link_fentry), "attach fentry", "err %ld\n",
 104                   PTR_ERR(link_fentry)))
 105                 goto close_prog;
 106         link_fexit = bpf_program__attach_trace(fexit);
 107         if (CHECK(IS_ERR(link_fexit), "attach fexit", "err %ld\n",
 108                   PTR_ERR(link_fexit)))
 109                 goto close_prog;
 110
 111         perf_buf_map = bpf_object__find_map_by_name(obj2, "perf_buf_map");
 112         if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
 113                 goto close_prog;
 114
 115         /* set up perf buffer */
 116         pb_opts.sample_cb = on_sample;
 117         pb_opts.ctx = &passed;
 118         pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
 119         if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
 120                 goto close_prog;
 121
 122         memcpy(skb.cb, &cb, sizeof(cb));
 123         err = bpf_prog_test_run_xattr(&tattr);
 124         duration = tattr.duration;
 125         CHECK(err || tattr.retval, "ipv6",
 126               "err %d errno %d retval %d duration %d\n",
 127               err, errno, tattr.retval, duration);
 128
 129         /* read perf buffer */
 130         err = perf_buffer__poll(pb, 100);
 131         if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
 132                 goto close_prog;
 133
 134         /* make sure kfree_skb program was triggered
 135          * and it sent expected skb into ring buffer
 136          */
 137         ASSERT_TRUE(passed, "passed");
 138
 139         err = bpf_map_lookup_elem(bpf_map__fd(global_data), &zero, test_ok);
 140         if (CHECK(err, "get_result",
 141                   "failed to get output data: %d\n", err))
 142                 goto close_prog;
 143
 144         CHECK_FAIL(!test_ok[0] || !test_ok[1]);
 145 close_prog:
 146         perf_buffer__free(pb);
 147         if (!IS_ERR_OR_NULL(link))
 148                 bpf_link__destroy(link);
 149         if (!IS_ERR_OR_NULL(link_fentry))
 150                 bpf_link__destroy(link_fentry);
 151         if (!IS_ERR_OR_NULL(link_fexit))
 152                 bpf_link__destroy(link_fexit);
 153         bpf_object__close(obj);
 154         bpf_object__close(obj2);
 155 }