samples/bpf/xdp_tx_iptunnel_user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2016 Facebook
   3  */
   4 #include <linux/bpf.h>
   5 #include <linux/if_link.h>
   6 #include <assert.h>
   7 #include <errno.h>
   8 #include <signal.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <net/if.h>
  13 #include <sys/resource.h>
  14 #include <arpa/inet.h>
  15 #include <netinet/ether.h>
  16 #include <unistd.h>
  17 #include <time.h>
  18 #include <bpf/libbpf.h>
  19 #include <bpf/bpf.h>
  20 #include "bpf_util.h"
  21 #include "xdp_tx_iptunnel_common.h"
  22
  23 #define STATS_INTERVAL_S 2U
  24
  25 static int ifindex = -1;
  26 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
  27 static int rxcnt_map_fd;
  28 static __u32 prog_id;
  29
  30 static void int_exit(int sig)
  31 {
  32         __u32 curr_prog_id = 0;
  33
  34         if (ifindex > -1) {
  35                 if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
  36                         printf("bpf_get_link_xdp_id failed\n");
  37                         exit(1);
  38                 }
  39                 if (prog_id == curr_prog_id)
  40                         bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
  41                 else if (!curr_prog_id)
  42                         printf("couldn't find a prog id on a given iface\n");
  43                 else
  44                         printf("program on interface changed, not removing\n");
  45         }
  46         exit(0);
  47 }
  48
  49 /* simple per-protocol drop counter
  50  */
  51 static void poll_stats(unsigned int kill_after_s)
  52 {
  53         const unsigned int nr_protos = 256;
  54         unsigned int nr_cpus = bpf_num_possible_cpus();
  55         time_t started_at = time(NULL);
  56         __u64 values[nr_cpus], prev[nr_protos][nr_cpus];
  57         __u32 proto;
  58         int i;
  59
  60         memset(prev, 0, sizeof(prev));
  61
  62         while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
  63                 sleep(STATS_INTERVAL_S);
  64
  65                 for (proto = 0; proto < nr_protos; proto++) {
  66                         __u64 sum = 0;
  67
  68                         assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
  69                                                    values) == 0);
  70                         for (i = 0; i < nr_cpus; i++)
  71                                 sum += (values[i] - prev[proto][i]);
  72
  73                         if (sum)
  74                                 printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
  75                                        proto, sum, sum / STATS_INTERVAL_S);
  76                         memcpy(prev[proto], values, sizeof(values));
  77                 }
  78         }
  79 }
  80
  81 static void usage(const char *cmd)
  82 {
  83         printf("Start a XDP prog which encapsulates incoming packets\n"
  84                "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
  85                "is used to select packets to encapsulate\n\n");
  86         printf("Usage: %s [...]\n", cmd);
  87         printf("    -i <ifname|ifindex> Interface\n");
  88         printf("    -a <vip-service-address> IPv4 or IPv6\n");
  89         printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
  90         printf("    -s <source-ip> Used in the IPTunnel header\n");
  91         printf("    -d <dest-ip> Used in the IPTunnel header\n");
  92         printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
  93         printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
  94         printf("    -P <IP-Protocol> Default is TCP\n");
  95         printf("    -S use skb-mode\n");
  96         printf("    -N enforce native mode\n");
  97         printf("    -F Force loading the XDP prog\n");
  98         printf("    -h Display this help\n");
  99 }
 100
 101 static int parse_ipstr(const char *ipstr, unsigned int *addr)
 102 {
 103         if (inet_pton(AF_INET6, ipstr, addr) == 1) {
 104                 return AF_INET6;
 105         } else if (inet_pton(AF_INET, ipstr, addr) == 1) {
 106                 addr[1] = addr[2] = addr[3] = 0;
 107                 return AF_INET;
 108         }
 109
 110         fprintf(stderr, "%s is an invalid IP\n", ipstr);
 111         return AF_UNSPEC;
 112 }
 113
 114 static int parse_ports(const char *port_str, int *min_port, int *max_port)
 115 {
 116         char *end;
 117         long tmp_min_port;
 118         long tmp_max_port;
 119
 120         tmp_min_port = strtol(optarg, &end, 10);
 121         if (tmp_min_port < 1 || tmp_min_port > 65535) {
 122                 fprintf(stderr, "Invalid port(s):%s\n", optarg);
 123                 return 1;
 124         }
 125
 126         if (*end == '-') {
 127                 end++;
 128                 tmp_max_port = strtol(end, NULL, 10);
 129                 if (tmp_max_port < 1 || tmp_max_port > 65535) {
 130                         fprintf(stderr, "Invalid port(s):%s\n", optarg);
 131                         return 1;
 132                 }
 133         } else {
 134                 tmp_max_port = tmp_min_port;
 135         }
 136
 137         if (tmp_min_port > tmp_max_port) {
 138                 fprintf(stderr, "Invalid port(s):%s\n", optarg);
 139                 return 1;
 140         }
 141
 142         if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
 143                 fprintf(stderr, "Port range (%s) is larger than %u\n",
 144                         port_str, MAX_IPTNL_ENTRIES);
 145                 return 1;
 146         }
 147         *min_port = tmp_min_port;
 148         *max_port = tmp_max_port;
 149
 150         return 0;
 151 }
 152
 153 int main(int argc, char **argv)
 154 {
 155         struct bpf_prog_load_attr prog_load_attr = {
 156                 .prog_type      = BPF_PROG_TYPE_XDP,
 157         };
 158         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 159         int min_port = 0, max_port = 0, vip2tnl_map_fd;
 160         const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
 161         unsigned char opt_flags[256] = {};
 162         struct bpf_prog_info info = {};
 163         __u32 info_len = sizeof(info);
 164         unsigned int kill_after_s = 0;
 165         struct iptnl_info tnl = {};
 166         struct bpf_object *obj;
 167         struct vip vip = {};
 168         char filename[256];
 169         int opt, prog_fd;
 170         int i, err;
 171
 172         tnl.family = AF_UNSPEC;
 173         vip.protocol = IPPROTO_TCP;
 174
 175         for (i = 0; i < strlen(optstr); i++)
 176                 if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
 177                         opt_flags[(unsigned char)optstr[i]] = 1;
 178
 179         while ((opt = getopt(argc, argv, optstr)) != -1) {
 180                 unsigned short family;
 181                 unsigned int *v6;
 182
 183                 switch (opt) {
 184                 case 'i':
 185                         ifindex = if_nametoindex(optarg);
 186                         if (!ifindex)
 187                                 ifindex = atoi(optarg);
 188                         break;
 189                 case 'a':
 190                         vip.family = parse_ipstr(optarg, vip.daddr.v6);
 191                         if (vip.family == AF_UNSPEC)
 192                                 return 1;
 193                         break;
 194                 case 'p':
 195                         if (parse_ports(optarg, &min_port, &max_port))
 196                                 return 1;
 197                         break;
 198                 case 'P':
 199                         vip.protocol = atoi(optarg);
 200                         break;
 201                 case 's':
 202                 case 'd':
 203                         if (opt == 's')
 204                                 v6 = tnl.saddr.v6;
 205                         else
 206                                 v6 = tnl.daddr.v6;
 207
 208                         family = parse_ipstr(optarg, v6);
 209                         if (family == AF_UNSPEC)
 210                                 return 1;
 211                         if (tnl.family == AF_UNSPEC) {
 212                                 tnl.family = family;
 213                         } else if (tnl.family != family) {
 214                                 fprintf(stderr,
 215                                         "The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
 216                                 return 1;
 217                         }
 218                         break;
 219                 case 'm':
 220                         if (!ether_aton_r(optarg,
 221                                           (struct ether_addr *)tnl.dmac)) {
 222                                 fprintf(stderr, "Invalid mac address:%s\n",
 223                                         optarg);
 224                                 return 1;
 225                         }
 226                         break;
 227                 case 'T':
 228                         kill_after_s = atoi(optarg);
 229                         break;
 230                 case 'S':
 231                         xdp_flags |= XDP_FLAGS_SKB_MODE;
 232                         break;
 233                 case 'N':
 234                         /* default, set below */
 235                         break;
 236                 case 'F':
 237                         xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
 238                         break;
 239                 default:
 240                         usage(argv[0]);
 241                         return 1;
 242                 }
 243                 opt_flags[opt] = 0;
 244         }
 245
 246         if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
 247                 xdp_flags |= XDP_FLAGS_DRV_MODE;
 248
 249         for (i = 0; i < strlen(optstr); i++) {
 250                 if (opt_flags[(unsigned int)optstr[i]]) {
 251                         fprintf(stderr, "Missing argument -%c\n", optstr[i]);
 252                         usage(argv[0]);
 253                         return 1;
 254                 }
 255         }
 256
 257         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
 258                 perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
 259                 return 1;
 260         }
 261
 262         if (!ifindex) {
 263                 fprintf(stderr, "Invalid ifname\n");
 264                 return 1;
 265         }
 266
 267         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 268         prog_load_attr.file = filename;
 269
 270         if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 271                 return 1;
 272
 273         if (!prog_fd) {
 274                 printf("bpf_prog_load_xattr: %s\n", strerror(errno));
 275                 return 1;
 276         }
 277
 278         rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
 279         vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
 280         if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
 281                 printf("bpf_object__find_map_fd_by_name failed\n");
 282                 return 1;
 283         }
 284
 285         signal(SIGINT, int_exit);
 286         signal(SIGTERM, int_exit);
 287
 288         while (min_port <= max_port) {
 289                 vip.dport = htons(min_port++);
 290                 if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
 291                                         BPF_NOEXIST)) {
 292                         perror("bpf_map_update_elem(&vip2tnl)");
 293                         return 1;
 294                 }
 295         }
 296
 297         if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
 298                 printf("link set xdp fd failed\n");
 299                 return 1;
 300         }
 301
 302         err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
 303         if (err) {
 304                 printf("can't get prog info - %s\n", strerror(errno));
 305                 return err;
 306         }
 307         prog_id = info.id;
 308
 309         poll_stats(kill_after_s);
 310
 311         bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
 312
 313         return 0;
 314 }