tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <stddef.h>
   3 #include <string.h>
   4 #include <netinet/in.h>
   5 #include <linux/bpf.h>
   6 #include <linux/if_ether.h>
   7 #include <linux/if_packet.h>
   8 #include <linux/ip.h>
   9 #include <linux/ipv6.h>
  10 #include <linux/types.h>
  11 #include <linux/socket.h>
  12 #include <linux/tcp.h>
  13 #include <bpf/bpf_helpers.h>
  14 #include <bpf/bpf_endian.h>
  15 #include "test_tcpbpf.h"
  16
  17 struct {
  18         __uint(type, BPF_MAP_TYPE_ARRAY);
  19         __uint(max_entries, 4);
  20         __type(key, __u32);
  21         __type(value, struct tcpbpf_globals);
  22 } global_map SEC(".maps");
  23
  24 struct {
  25         __uint(type, BPF_MAP_TYPE_ARRAY);
  26         __uint(max_entries, 2);
  27         __type(key, __u32);
  28         __type(value, int);
  29 } sockopt_results SEC(".maps");
  30
  31 static inline void update_event_map(int event)
  32 {
  33         __u32 key = 0;
  34         struct tcpbpf_globals g, *gp;
  35
  36         gp = bpf_map_lookup_elem(&global_map, &key);
  37         if (gp == NULL) {
  38                 struct tcpbpf_globals g = {0};
  39
  40                 g.event_map |= (1 << event);
  41                 bpf_map_update_elem(&global_map, &key, &g,
  42                             BPF_ANY);
  43         } else {
  44                 g = *gp;
  45                 g.event_map |= (1 << event);
  46                 bpf_map_update_elem(&global_map, &key, &g,
  47                             BPF_ANY);
  48         }
  49 }
  50
  51 int _version SEC("version") = 1;
  52
  53 SEC("sockops")
  54 int bpf_testcb(struct bpf_sock_ops *skops)
  55 {
  56         char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
  57         struct bpf_sock_ops *reuse = skops;
  58         struct tcphdr *thdr;
  59         int good_call_rv = 0;
  60         int bad_call_rv = 0;
  61         int save_syn = 1;
  62         int rv = -1;
  63         int v = 0;
  64         int op;
  65
  66         /* Test reading fields in bpf_sock_ops using single register */
  67         asm volatile (
  68                 "%[reuse] = *(u32 *)(%[reuse] +96)"
  69                 : [reuse] "+r"(reuse)
  70                 :);
  71
  72         asm volatile (
  73                 "%[op] = *(u32 *)(%[skops] +96)"
  74                 : [op] "+r"(op)
  75                 : [skops] "r"(skops)
  76                 :);
  77
  78         asm volatile (
  79                 "r9 = %[skops];\n"
  80                 "r8 = *(u32 *)(r9 +164);\n"
  81                 "*(u32 *)(r9 +164) = r8;\n"
  82                 :: [skops] "r"(skops)
  83                 : "r9", "r8");
  84
  85         asm volatile (
  86                 "r1 = %[skops];\n"
  87                 "r1 = *(u64 *)(r1 +184);\n"
  88                 "if r1 == 0 goto +1;\n"
  89                 "r1 = *(u32 *)(r1 +4);\n"
  90                 :: [skops] "r"(skops):"r1");
  91
  92         asm volatile (
  93                 "r9 = %[skops];\n"
  94                 "r9 = *(u64 *)(r9 +184);\n"
  95                 "if r9 == 0 goto +1;\n"
  96                 "r9 = *(u32 *)(r9 +4);\n"
  97                 :: [skops] "r"(skops):"r9");
  98
  99         asm volatile (
 100                 "r1 = %[skops];\n"
 101                 "r2 = *(u64 *)(r1 +184);\n"
 102                 "if r2 == 0 goto +1;\n"
 103                 "r2 = *(u32 *)(r2 +4);\n"
 104                 :: [skops] "r"(skops):"r1", "r2");
 105
 106         op = (int) skops->op;
 107
 108         update_event_map(op);
 109
 110         switch (op) {
 111         case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
 112                 /* Test failure to set largest cb flag (assumes not defined) */
 113                 bad_call_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
 114                 /* Set callback */
 115                 good_call_rv = bpf_sock_ops_cb_flags_set(skops,
 116                                                  BPF_SOCK_OPS_STATE_CB_FLAG);
 117                 /* Update results */
 118                 {
 119                         __u32 key = 0;
 120                         struct tcpbpf_globals g, *gp;
 121
 122                         gp = bpf_map_lookup_elem(&global_map, &key);
 123                         if (!gp)
 124                                 break;
 125                         g = *gp;
 126                         g.bad_cb_test_rv = bad_call_rv;
 127                         g.good_cb_test_rv = good_call_rv;
 128                         bpf_map_update_elem(&global_map, &key, &g,
 129                                             BPF_ANY);
 130                 }
 131                 break;
 132         case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
 133                 skops->sk_txhash = 0x12345f;
 134                 v = 0xff;
 135                 rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v,
 136                                     sizeof(v));
 137                 if (skops->family == AF_INET6) {
 138                         v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN,
 139                                            header, (sizeof(struct ipv6hdr) +
 140                                                     sizeof(struct tcphdr)));
 141                         if (!v) {
 142                                 int offset = sizeof(struct ipv6hdr);
 143
 144                                 thdr = (struct tcphdr *)(header + offset);
 145                                 v = thdr->syn;
 146                                 __u32 key = 1;
 147
 148                                 bpf_map_update_elem(&sockopt_results, &key, &v,
 149                                                     BPF_ANY);
 150                         }
 151                 }
 152                 break;
 153         case BPF_SOCK_OPS_RTO_CB:
 154                 break;
 155         case BPF_SOCK_OPS_RETRANS_CB:
 156                 break;
 157         case BPF_SOCK_OPS_STATE_CB:
 158                 if (skops->args[1] == BPF_TCP_CLOSE) {
 159                         __u32 key = 0;
 160                         struct tcpbpf_globals g, *gp;
 161
 162                         gp = bpf_map_lookup_elem(&global_map, &key);
 163                         if (!gp)
 164                                 break;
 165                         g = *gp;
 166                         if (skops->args[0] == BPF_TCP_LISTEN) {
 167                                 g.num_listen++;
 168                         } else {
 169                                 g.total_retrans = skops->total_retrans;
 170                                 g.data_segs_in = skops->data_segs_in;
 171                                 g.data_segs_out = skops->data_segs_out;
 172                                 g.bytes_received = skops->bytes_received;
 173                                 g.bytes_acked = skops->bytes_acked;
 174                         }
 175                         g.num_close_events++;
 176                         bpf_map_update_elem(&global_map, &key, &g,
 177                                             BPF_ANY);
 178                 }
 179                 break;
 180         case BPF_SOCK_OPS_TCP_LISTEN_CB:
 181                 bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG);
 182                 v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
 183                                    &save_syn, sizeof(save_syn));
 184                 /* Update global map w/ result of setsock opt */
 185                 __u32 key = 0;
 186
 187                 bpf_map_update_elem(&sockopt_results, &key, &v, BPF_ANY);
 188                 break;
 189         default:
 190                 rv = -1;
 191         }
 192         skops->reply = rv;
 193         return 1;
 194 }
 195 char _license[] SEC("license") = "GPL";