samples/bpf/xdp_redirect_map_user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
   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 <stdbool.h>
  12 #include <string.h>
  13 #include <net/if.h>
  14 #include <unistd.h>
  15 #include <libgen.h>
  16 #include <sys/resource.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/types.h>
  19 #include <sys/socket.h>
  20 #include <netinet/in.h>
  21
  22 #include "bpf_util.h"
  23 #include <bpf/bpf.h>
  24 #include <bpf/libbpf.h>
  25
  26 static int ifindex_in;
  27 static int ifindex_out;
  28 static bool ifindex_out_xdp_dummy_attached = true;
  29 static bool xdp_devmap_attached;
  30 static __u32 prog_id;
  31 static __u32 dummy_prog_id;
  32
  33 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
  34 static int rxcnt_map_fd;
  35
  36 static void int_exit(int sig)
  37 {
  38         __u32 curr_prog_id = 0;
  39
  40         if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
  41                 printf("bpf_get_link_xdp_id failed\n");
  42                 exit(1);
  43         }
  44         if (prog_id == curr_prog_id)
  45                 bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
  46         else if (!curr_prog_id)
  47                 printf("couldn't find a prog id on iface IN\n");
  48         else
  49                 printf("program on iface IN changed, not removing\n");
  50
  51         if (ifindex_out_xdp_dummy_attached) {
  52                 curr_prog_id = 0;
  53                 if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
  54                                         xdp_flags)) {
  55                         printf("bpf_get_link_xdp_id failed\n");
  56                         exit(1);
  57                 }
  58                 if (dummy_prog_id == curr_prog_id)
  59                         bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
  60                 else if (!curr_prog_id)
  61                         printf("couldn't find a prog id on iface OUT\n");
  62                 else
  63                         printf("program on iface OUT changed, not removing\n");
  64         }
  65         exit(0);
  66 }
  67
  68 static void poll_stats(int interval, int ifindex)
  69 {
  70         unsigned int nr_cpus = bpf_num_possible_cpus();
  71         __u64 values[nr_cpus], prev[nr_cpus];
  72
  73         memset(prev, 0, sizeof(prev));
  74
  75         while (1) {
  76                 __u64 sum = 0;
  77                 __u32 key = 0;
  78                 int i;
  79
  80                 sleep(interval);
  81                 assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
  82                 for (i = 0; i < nr_cpus; i++)
  83                         sum += (values[i] - prev[i]);
  84                 if (sum)
  85                         printf("ifindex %i: %10llu pkt/s\n",
  86                                ifindex, sum / interval);
  87                 memcpy(prev, values, sizeof(values));
  88         }
  89 }
  90
  91 static int get_mac_addr(unsigned int ifindex_out, void *mac_addr)
  92 {
  93         char ifname[IF_NAMESIZE];
  94         struct ifreq ifr;
  95         int fd, ret = -1;
  96
  97         fd = socket(AF_INET, SOCK_DGRAM, 0);
  98         if (fd < 0)
  99                 return ret;
 100
 101         if (!if_indextoname(ifindex_out, ifname))
 102                 goto err_out;
 103
 104         strcpy(ifr.ifr_name, ifname);
 105
 106         if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
 107                 goto err_out;
 108
 109         memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
 110         ret = 0;
 111
 112 err_out:
 113         close(fd);
 114         return ret;
 115 }
 116
 117 static void usage(const char *prog)
 118 {
 119         fprintf(stderr,
 120                 "usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
 121                 "OPTS:\n"
 122                 "    -S    use skb-mode\n"
 123                 "    -N    enforce native mode\n"
 124                 "    -F    force loading prog\n"
 125                 "    -X    load xdp program on egress\n",
 126                 prog);
 127 }
 128
 129 int main(int argc, char **argv)
 130 {
 131         struct bpf_prog_load_attr prog_load_attr = {
 132                 .prog_type      = BPF_PROG_TYPE_UNSPEC,
 133         };
 134         struct bpf_program *prog, *dummy_prog, *devmap_prog;
 135         int prog_fd, dummy_prog_fd, devmap_prog_fd = 0;
 136         int tx_port_map_fd, tx_mac_map_fd;
 137         struct bpf_devmap_val devmap_val;
 138         struct bpf_prog_info info = {};
 139         __u32 info_len = sizeof(info);
 140         const char *optstr = "FSNX";
 141         struct bpf_object *obj;
 142         int ret, opt, key = 0;
 143         char filename[256];
 144
 145         while ((opt = getopt(argc, argv, optstr)) != -1) {
 146                 switch (opt) {
 147                 case 'S':
 148                         xdp_flags |= XDP_FLAGS_SKB_MODE;
 149                         break;
 150                 case 'N':
 151                         /* default, set below */
 152                         break;
 153                 case 'F':
 154                         xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
 155                         break;
 156                 case 'X':
 157                         xdp_devmap_attached = true;
 158                         break;
 159                 default:
 160                         usage(basename(argv[0]));
 161                         return 1;
 162                 }
 163         }
 164
 165         if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) {
 166                 xdp_flags |= XDP_FLAGS_DRV_MODE;
 167         } else if (xdp_devmap_attached) {
 168                 printf("Load xdp program on egress with SKB mode not supported yet\n");
 169                 return 1;
 170         }
 171
 172         if (optind == argc) {
 173                 printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
 174                 return 1;
 175         }
 176
 177         ifindex_in = if_nametoindex(argv[optind]);
 178         if (!ifindex_in)
 179                 ifindex_in = strtoul(argv[optind], NULL, 0);
 180
 181         ifindex_out = if_nametoindex(argv[optind + 1]);
 182         if (!ifindex_out)
 183                 ifindex_out = strtoul(argv[optind + 1], NULL, 0);
 184
 185         printf("input: %d output: %d\n", ifindex_in, ifindex_out);
 186
 187         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 188         prog_load_attr.file = filename;
 189
 190         if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 191                 return 1;
 192
 193         if (xdp_flags & XDP_FLAGS_SKB_MODE) {
 194                 prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_general");
 195                 tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_general");
 196         } else {
 197                 prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_native");
 198                 tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_native");
 199         }
 200         dummy_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_dummy_prog");
 201         if (!prog || dummy_prog < 0 || tx_port_map_fd < 0) {
 202                 printf("finding prog/dummy_prog/tx_port_map in obj file failed\n");
 203                 goto out;
 204         }
 205         prog_fd = bpf_program__fd(prog);
 206         dummy_prog_fd = bpf_program__fd(dummy_prog);
 207         if (prog_fd < 0 || dummy_prog_fd < 0 || tx_port_map_fd < 0) {
 208                 printf("bpf_prog_load_xattr: %s\n", strerror(errno));
 209                 return 1;
 210         }
 211
 212         tx_mac_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_mac");
 213         rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
 214         if (tx_mac_map_fd < 0 || rxcnt_map_fd < 0) {
 215                 printf("bpf_object__find_map_fd_by_name failed\n");
 216                 return 1;
 217         }
 218
 219         if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
 220                 printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
 221                 return 1;
 222         }
 223
 224         ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
 225         if (ret) {
 226                 printf("can't get prog info - %s\n", strerror(errno));
 227                 return ret;
 228         }
 229         prog_id = info.id;
 230
 231         /* Loading dummy XDP prog on out-device */
 232         if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
 233                             (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
 234                 printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
 235                 ifindex_out_xdp_dummy_attached = false;
 236         }
 237
 238         memset(&info, 0, sizeof(info));
 239         ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
 240         if (ret) {
 241                 printf("can't get prog info - %s\n", strerror(errno));
 242                 return ret;
 243         }
 244         dummy_prog_id = info.id;
 245
 246         /* Load 2nd xdp prog on egress. */
 247         if (xdp_devmap_attached) {
 248                 unsigned char mac_addr[6];
 249
 250                 devmap_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_egress");
 251                 if (!devmap_prog) {
 252                         printf("finding devmap_prog in obj file failed\n");
 253                         goto out;
 254                 }
 255                 devmap_prog_fd = bpf_program__fd(devmap_prog);
 256                 if (devmap_prog_fd < 0) {
 257                         printf("finding devmap_prog fd failed\n");
 258                         goto out;
 259                 }
 260
 261                 if (get_mac_addr(ifindex_out, mac_addr) < 0) {
 262                         printf("get interface %d mac failed\n", ifindex_out);
 263                         goto out;
 264                 }
 265
 266                 ret = bpf_map_update_elem(tx_mac_map_fd, &key, mac_addr, 0);
 267                 if (ret) {
 268                         perror("bpf_update_elem tx_mac_map_fd");
 269                         goto out;
 270                 }
 271         }
 272
 273         signal(SIGINT, int_exit);
 274         signal(SIGTERM, int_exit);
 275
 276         devmap_val.ifindex = ifindex_out;
 277         devmap_val.bpf_prog.fd = devmap_prog_fd;
 278         ret = bpf_map_update_elem(tx_port_map_fd, &key, &devmap_val, 0);
 279         if (ret) {
 280                 perror("bpf_update_elem");
 281                 goto out;
 282         }
 283
 284         poll_stats(2, ifindex_out);
 285
 286 out:
 287         return 0;
 288 }