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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3 #include <network_helpers.h>
   4 #include <net/if.h>
   5 #include "empty_skb.skel.h"
   6
   7 void test_empty_skb(void)
   8 {
   9         LIBBPF_OPTS(bpf_test_run_opts, tattr);
  10         struct empty_skb *bpf_obj = NULL;
  11         struct nstoken *tok = NULL;
  12         struct bpf_program *prog;
  13         char eth_hlen_pp[15];
  14         char eth_hlen[14];
  15         int veth_ifindex;
  16         int ipip_ifindex;
  17         int err;
  18         int i;
  19
  20         struct {
  21                 const char *msg;
  22                 const void *data_in;
  23                 __u32 data_size_in;
  24                 int *ifindex;
  25                 int err;
  26                 int ret;
  27                 int lwt_egress_ret; /* expected retval at lwt/egress */
  28                 bool success_on_tc;
  29         } tests[] = {
  30                 /* Empty packets are always rejected. */
  31
  32                 {
  33                         /* BPF_PROG_RUN ETH_HLEN size check */
  34                         .msg = "veth empty ingress packet",
  35                         .data_in = NULL,
  36                         .data_size_in = 0,
  37                         .ifindex = &veth_ifindex,
  38                         .err = -EINVAL,
  39                 },
  40                 {
  41                         /* BPF_PROG_RUN ETH_HLEN size check */
  42                         .msg = "ipip empty ingress packet",
  43                         .data_in = NULL,
  44                         .data_size_in = 0,
  45                         .ifindex = &ipip_ifindex,
  46                         .err = -EINVAL,
  47                 },
  48
  49                 /* ETH_HLEN-sized packets:
  50                  * - can not be redirected at LWT_XMIT
  51                  * - can be redirected at TC to non-tunneling dest
  52                  */
  53
  54                 {
  55                         /* __bpf_redirect_common */
  56                         .msg = "veth ETH_HLEN packet ingress",
  57                         .data_in = eth_hlen,
  58                         .data_size_in = sizeof(eth_hlen),
  59                         .ifindex = &veth_ifindex,
  60                         .ret = -ERANGE,
  61                         .lwt_egress_ret = -ERANGE,
  62                         .success_on_tc = true,
  63                 },
  64                 {
  65                         /* __bpf_redirect_no_mac
  66                          *
  67                          * lwt: skb->len=0 <= skb_network_offset=0
  68                          * tc: skb->len=14 <= skb_network_offset=14
  69                          */
  70                         .msg = "ipip ETH_HLEN packet ingress",
  71                         .data_in = eth_hlen,
  72                         .data_size_in = sizeof(eth_hlen),
  73                         .ifindex = &ipip_ifindex,
  74                         .ret = -ERANGE,
  75                         .lwt_egress_ret = -ERANGE,
  76                 },
  77
  78                 /* ETH_HLEN+1-sized packet should be redirected. */
  79
  80                 {
  81                         .msg = "veth ETH_HLEN+1 packet ingress",
  82                         .data_in = eth_hlen_pp,
  83                         .data_size_in = sizeof(eth_hlen_pp),
  84                         .ifindex = &veth_ifindex,
  85                         .lwt_egress_ret = 1, /* veth_xmit NET_XMIT_DROP */
  86                 },
  87                 {
  88                         .msg = "ipip ETH_HLEN+1 packet ingress",
  89                         .data_in = eth_hlen_pp,
  90                         .data_size_in = sizeof(eth_hlen_pp),
  91                         .ifindex = &ipip_ifindex,
  92                 },
  93         };
  94
  95         SYS(out, "ip netns add empty_skb");
  96         tok = open_netns("empty_skb");
  97         SYS(out, "ip link add veth0 type veth peer veth1");
  98         SYS(out, "ip link set dev veth0 up");
  99         SYS(out, "ip link set dev veth1 up");
 100         SYS(out, "ip addr add 10.0.0.1/8 dev veth0");
 101         SYS(out, "ip addr add 10.0.0.2/8 dev veth1");
 102         veth_ifindex = if_nametoindex("veth0");
 103
 104         SYS(out, "ip link add ipip0 type ipip local 10.0.0.1 remote 10.0.0.2");
 105         SYS(out, "ip link set ipip0 up");
 106         SYS(out, "ip addr add 192.168.1.1/16 dev ipip0");
 107         ipip_ifindex = if_nametoindex("ipip0");
 108
 109         bpf_obj = empty_skb__open_and_load();
 110         if (!ASSERT_OK_PTR(bpf_obj, "open skeleton"))
 111                 goto out;
 112
 113         for (i = 0; i < ARRAY_SIZE(tests); i++) {
 114                 bpf_object__for_each_program(prog, bpf_obj->obj) {
 115                         bool at_egress = strstr(bpf_program__name(prog), "egress") != NULL;
 116                         bool at_tc = !strncmp(bpf_program__section_name(prog), "tc", 2);
 117                         int expected_ret;
 118                         char buf[128];
 119
 120                         expected_ret = at_egress && !at_tc ? tests[i].lwt_egress_ret : tests[i].ret;
 121
 122                         tattr.data_in = tests[i].data_in;
 123                         tattr.data_size_in = tests[i].data_size_in;
 124
 125                         tattr.data_size_out = 0;
 126                         bpf_obj->bss->ifindex = *tests[i].ifindex;
 127                         bpf_obj->bss->ret = 0;
 128                         err = bpf_prog_test_run_opts(bpf_program__fd(prog), &tattr);
 129                         sprintf(buf, "err: %s [%s]", tests[i].msg, bpf_program__name(prog));
 130
 131                         if (at_tc && tests[i].success_on_tc)
 132                                 ASSERT_GE(err, 0, buf);
 133                         else
 134                                 ASSERT_EQ(err, tests[i].err, buf);
 135                         sprintf(buf, "ret: %s [%s]", tests[i].msg, bpf_program__name(prog));
 136                         if (at_tc && tests[i].success_on_tc)
 137                                 ASSERT_GE(bpf_obj->bss->ret, 0, buf);
 138                         else
 139                                 ASSERT_EQ(bpf_obj->bss->ret, expected_ret, buf);
 140                 }
 141         }
 142
 143 out:
 144         if (bpf_obj)
 145                 empty_skb__destroy(bpf_obj);
 146         if (tok)
 147                 close_netns(tok);
 148         SYS_NOFAIL("ip netns del empty_skb");
 149 }