samples/bpf/xdp_tx_iptunnel_user.c

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