samples/bpf/xdp_router_ipv4_user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (C) 2017 Cavium, Inc.
   3  */
   4 #include <linux/bpf.h>
   5 #include <linux/netlink.h>
   6 #include <linux/rtnetlink.h>
   7 #include <assert.h>
   8 #include <errno.h>
   9 #include <signal.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/socket.h>
  14 #include <unistd.h>
  15 #include <bpf/bpf.h>
  16 #include <arpa/inet.h>
  17 #include <fcntl.h>
  18 #include <poll.h>
  19 #include <net/if.h>
  20 #include <netdb.h>
  21 #include <sys/ioctl.h>
  22 #include <sys/syscall.h>
  23 #include "bpf_util.h"
  24 #include "bpf/libbpf.h"
  25 #include <sys/resource.h>
  26 #include <libgen.h>
  27
  28 int sock, sock_arp, flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
  29 static int total_ifindex;
  30 static int *ifindex_list;
  31 static __u32 *prog_id_list;
  32 char buf[8192];
  33 static int lpm_map_fd;
  34 static int rxcnt_map_fd;
  35 static int arp_table_map_fd;
  36 static int exact_match_map_fd;
  37 static int tx_port_map_fd;
  38
  39 static int get_route_table(int rtm_family);
  40 static void int_exit(int sig)
  41 {
  42         __u32 prog_id = 0;
  43         int i = 0;
  44
  45         for (i = 0; i < total_ifindex; i++) {
  46                 if (bpf_get_link_xdp_id(ifindex_list[i], &prog_id, flags)) {
  47                         printf("bpf_get_link_xdp_id on iface %d failed\n",
  48                                ifindex_list[i]);
  49                         exit(1);
  50                 }
  51                 if (prog_id_list[i] == prog_id)
  52                         bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
  53                 else if (!prog_id)
  54                         printf("couldn't find a prog id on iface %d\n",
  55                                ifindex_list[i]);
  56                 else
  57                         printf("program on iface %d changed, not removing\n",
  58                                ifindex_list[i]);
  59                 prog_id = 0;
  60         }
  61         exit(0);
  62 }
  63
  64 static void close_and_exit(int sig)
  65 {
  66         close(sock);
  67         close(sock_arp);
  68
  69         int_exit(0);
  70 }
  71
  72 /* Get the mac address of the interface given interface name */
  73 static __be64 getmac(char *iface)
  74 {
  75         struct ifreq ifr;
  76         __be64 mac = 0;
  77         int fd, i;
  78
  79         fd = socket(AF_INET, SOCK_DGRAM, 0);
  80         ifr.ifr_addr.sa_family = AF_INET;
  81         strncpy(ifr.ifr_name, iface, IFNAMSIZ - 1);
  82         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
  83                 printf("ioctl failed leaving....\n");
  84                 return -1;
  85         }
  86         for (i = 0; i < 6 ; i++)
  87                 *((__u8 *)&mac + i) = (__u8)ifr.ifr_hwaddr.sa_data[i];
  88         close(fd);
  89         return mac;
  90 }
  91
  92 static int recv_msg(struct sockaddr_nl sock_addr, int sock)
  93 {
  94         struct nlmsghdr *nh;
  95         int len, nll = 0;
  96         char *buf_ptr;
  97
  98         buf_ptr = buf;
  99         while (1) {
 100                 len = recv(sock, buf_ptr, sizeof(buf) - nll, 0);
 101                 if (len < 0)
 102                         return len;
 103
 104                 nh = (struct nlmsghdr *)buf_ptr;
 105
 106                 if (nh->nlmsg_type == NLMSG_DONE)
 107                         break;
 108                 buf_ptr += len;
 109                 nll += len;
 110                 if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH)
 111                         break;
 112
 113                 if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE)
 114                         break;
 115         }
 116         return nll;
 117 }
 118
 119 /* Function to parse the route entry returned by netlink
 120  * Updates the route entry related map entries
 121  */
 122 static void read_route(struct nlmsghdr *nh, int nll)
 123 {
 124         char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
 125         struct bpf_lpm_trie_key *prefix_key;
 126         struct rtattr *rt_attr;
 127         struct rtmsg *rt_msg;
 128         int rtm_family;
 129         int rtl;
 130         int i;
 131         struct route_table {
 132                 int  dst_len, iface, metric;
 133                 char *iface_name;
 134                 __be32 dst, gw;
 135                 __be64 mac;
 136         } route;
 137         struct arp_table {
 138                 __be64 mac;
 139                 __be32 dst;
 140         };
 141
 142         struct direct_map {
 143                 struct arp_table arp;
 144                 int ifindex;
 145                 __be64 mac;
 146         } direct_entry;
 147
 148         if (nh->nlmsg_type == RTM_DELROUTE)
 149                 printf("DELETING Route entry\n");
 150         else if (nh->nlmsg_type == RTM_GETROUTE)
 151                 printf("READING Route entry\n");
 152         else if (nh->nlmsg_type == RTM_NEWROUTE)
 153                 printf("NEW Route entry\n");
 154         else
 155                 printf("%d\n", nh->nlmsg_type);
 156
 157         memset(&route, 0, sizeof(route));
 158         printf("Destination\t\tGateway\t\tGenmask\t\tMetric\t\tIface\n");
 159         for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
 160                 rt_msg = (struct rtmsg *)NLMSG_DATA(nh);
 161                 rtm_family = rt_msg->rtm_family;
 162                 if (rtm_family == AF_INET)
 163                         if (rt_msg->rtm_table != RT_TABLE_MAIN)
 164                                 continue;
 165                 rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
 166                 rtl = RTM_PAYLOAD(nh);
 167
 168                 for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
 169                         switch (rt_attr->rta_type) {
 170                         case NDA_DST:
 171                                 sprintf(dsts, "%u",
 172                                         (*((__be32 *)RTA_DATA(rt_attr))));
 173                                 break;
 174                         case RTA_GATEWAY:
 175                                 sprintf(gws, "%u",
 176                                         *((__be32 *)RTA_DATA(rt_attr)));
 177                                 break;
 178                         case RTA_OIF:
 179                                 sprintf(ifs, "%u",
 180                                         *((int *)RTA_DATA(rt_attr)));
 181                                 break;
 182                         case RTA_METRICS:
 183                                 sprintf(metrics, "%u",
 184                                         *((int *)RTA_DATA(rt_attr)));
 185                         default:
 186                                 break;
 187                         }
 188                 }
 189                 sprintf(dsts_len, "%d", rt_msg->rtm_dst_len);
 190                 route.dst = atoi(dsts);
 191                 route.dst_len = atoi(dsts_len);
 192                 route.gw = atoi(gws);
 193                 route.iface = atoi(ifs);
 194                 route.metric = atoi(metrics);
 195                 route.iface_name = alloca(sizeof(char *) * IFNAMSIZ);
 196                 route.iface_name = if_indextoname(route.iface, route.iface_name);
 197                 route.mac = getmac(route.iface_name);
 198                 if (route.mac == -1)
 199                         int_exit(0);
 200                 assert(bpf_map_update_elem(tx_port_map_fd,
 201                                            &route.iface, &route.iface, 0) == 0);
 202                 if (rtm_family == AF_INET) {
 203                         struct trie_value {
 204                                 __u8 prefix[4];
 205                                 __be64 value;
 206                                 int ifindex;
 207                                 int metric;
 208                                 __be32 gw;
 209                         } *prefix_value;
 210
 211                         prefix_key = alloca(sizeof(*prefix_key) + 3);
 212                         prefix_value = alloca(sizeof(*prefix_value));
 213
 214                         prefix_key->prefixlen = 32;
 215                         prefix_key->prefixlen = route.dst_len;
 216                         direct_entry.mac = route.mac & 0xffffffffffff;
 217                         direct_entry.ifindex = route.iface;
 218                         direct_entry.arp.mac = 0;
 219                         direct_entry.arp.dst = 0;
 220                         if (route.dst_len == 32) {
 221                                 if (nh->nlmsg_type == RTM_DELROUTE) {
 222                                         assert(bpf_map_delete_elem(exact_match_map_fd,
 223                                                                    &route.dst) == 0);
 224                                 } else {
 225                                         if (bpf_map_lookup_elem(arp_table_map_fd,
 226                                                                 &route.dst,
 227                                                                 &direct_entry.arp.mac) == 0)
 228                                                 direct_entry.arp.dst = route.dst;
 229                                         assert(bpf_map_update_elem(exact_match_map_fd,
 230                                                                    &route.dst,
 231                                                                    &direct_entry, 0) == 0);
 232                                 }
 233                         }
 234                         for (i = 0; i < 4; i++)
 235                                 prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
 236
 237                         printf("%3d.%d.%d.%d\t\t%3x\t\t%d\t\t%d\t\t%s\n",
 238                                (int)prefix_key->data[0],
 239                                (int)prefix_key->data[1],
 240                                (int)prefix_key->data[2],
 241                                (int)prefix_key->data[3],
 242                                route.gw, route.dst_len,
 243                                route.metric,
 244                                route.iface_name);
 245                         if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
 246                                                 prefix_value) < 0) {
 247                                 for (i = 0; i < 4; i++)
 248                                         prefix_value->prefix[i] = prefix_key->data[i];
 249                                 prefix_value->value = route.mac & 0xffffffffffff;
 250                                 prefix_value->ifindex = route.iface;
 251                                 prefix_value->gw = route.gw;
 252                                 prefix_value->metric = route.metric;
 253
 254                                 assert(bpf_map_update_elem(lpm_map_fd,
 255                                                            prefix_key,
 256                                                            prefix_value, 0
 257                                                            ) == 0);
 258                         } else {
 259                                 if (nh->nlmsg_type == RTM_DELROUTE) {
 260                                         printf("deleting entry\n");
 261                                         printf("prefix key=%d.%d.%d.%d/%d",
 262                                                prefix_key->data[0],
 263                                                prefix_key->data[1],
 264                                                prefix_key->data[2],
 265                                                prefix_key->data[3],
 266                                                prefix_key->prefixlen);
 267                                         assert(bpf_map_delete_elem(lpm_map_fd,
 268                                                                    prefix_key
 269                                                                    ) == 0);
 270                                         /* Rereading the route table to check if
 271                                          * there is an entry with the same
 272                                          * prefix but a different metric as the
 273                                          * deleted enty.
 274                                          */
 275                                         get_route_table(AF_INET);
 276                                 } else if (prefix_key->data[0] ==
 277                                            prefix_value->prefix[0] &&
 278                                            prefix_key->data[1] ==
 279                                            prefix_value->prefix[1] &&
 280                                            prefix_key->data[2] ==
 281                                            prefix_value->prefix[2] &&
 282                                            prefix_key->data[3] ==
 283                                            prefix_value->prefix[3] &&
 284                                            route.metric >= prefix_value->metric) {
 285                                         continue;
 286                                 } else {
 287                                         for (i = 0; i < 4; i++)
 288                                                 prefix_value->prefix[i] =
 289                                                         prefix_key->data[i];
 290                                         prefix_value->value =
 291                                                 route.mac & 0xffffffffffff;
 292                                         prefix_value->ifindex = route.iface;
 293                                         prefix_value->gw = route.gw;
 294                                         prefix_value->metric = route.metric;
 295                                         assert(bpf_map_update_elem(lpm_map_fd,
 296                                                                    prefix_key,
 297                                                                    prefix_value,
 298                                                                    0) == 0);
 299                                 }
 300                         }
 301                 }
 302                 memset(&route, 0, sizeof(route));
 303                 memset(dsts, 0, sizeof(dsts));
 304                 memset(dsts_len, 0, sizeof(dsts_len));
 305                 memset(gws, 0, sizeof(gws));
 306                 memset(ifs, 0, sizeof(ifs));
 307                 memset(&route, 0, sizeof(route));
 308         }
 309 }
 310
 311 /* Function to read the existing route table  when the process is launched*/
 312 static int get_route_table(int rtm_family)
 313 {
 314         struct sockaddr_nl sa;
 315         struct nlmsghdr *nh;
 316         int sock, seq = 0;
 317         struct msghdr msg;
 318         struct iovec iov;
 319         int ret = 0;
 320         int nll;
 321
 322         struct {
 323                 struct nlmsghdr nl;
 324                 struct rtmsg rt;
 325                 char buf[8192];
 326         } req;
 327
 328         sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 329         if (sock < 0) {
 330                 printf("open netlink socket: %s\n", strerror(errno));
 331                 return -1;
 332         }
 333         memset(&sa, 0, sizeof(sa));
 334         sa.nl_family = AF_NETLINK;
 335         if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
 336                 printf("bind to netlink: %s\n", strerror(errno));
 337                 ret = -1;
 338                 goto cleanup;
 339         }
 340         memset(&req, 0, sizeof(req));
 341         req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 342         req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
 343         req.nl.nlmsg_type = RTM_GETROUTE;
 344
 345         req.rt.rtm_family = rtm_family;
 346         req.rt.rtm_table = RT_TABLE_MAIN;
 347         req.nl.nlmsg_pid = 0;
 348         req.nl.nlmsg_seq = ++seq;
 349         memset(&msg, 0, sizeof(msg));
 350         iov.iov_base = (void *)&req.nl;
 351         iov.iov_len = req.nl.nlmsg_len;
 352         msg.msg_iov = &iov;
 353         msg.msg_iovlen = 1;
 354         ret = sendmsg(sock, &msg, 0);
 355         if (ret < 0) {
 356                 printf("send to netlink: %s\n", strerror(errno));
 357                 ret = -1;
 358                 goto cleanup;
 359         }
 360         memset(buf, 0, sizeof(buf));
 361         nll = recv_msg(sa, sock);
 362         if (nll < 0) {
 363                 printf("recv from netlink: %s\n", strerror(nll));
 364                 ret = -1;
 365                 goto cleanup;
 366         }
 367         nh = (struct nlmsghdr *)buf;
 368         read_route(nh, nll);
 369 cleanup:
 370         close(sock);
 371         return ret;
 372 }
 373
 374 /* Function to parse the arp entry returned by netlink
 375  * Updates the arp entry related map entries
 376  */
 377 static void read_arp(struct nlmsghdr *nh, int nll)
 378 {
 379         struct rtattr *rt_attr;
 380         char dsts[24], mac[24];
 381         struct ndmsg *rt_msg;
 382         int rtl, ndm_family;
 383
 384         struct arp_table {
 385                 __be64 mac;
 386                 __be32 dst;
 387         } arp_entry;
 388         struct direct_map {
 389                 struct arp_table arp;
 390                 int ifindex;
 391                 __be64 mac;
 392         } direct_entry;
 393
 394         if (nh->nlmsg_type == RTM_GETNEIGH)
 395                 printf("READING arp entry\n");
 396         printf("Address\tHwAddress\n");
 397         for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
 398                 rt_msg = (struct ndmsg *)NLMSG_DATA(nh);
 399                 rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
 400                 ndm_family = rt_msg->ndm_family;
 401                 rtl = RTM_PAYLOAD(nh);
 402                 for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
 403                         switch (rt_attr->rta_type) {
 404                         case NDA_DST:
 405                                 sprintf(dsts, "%u",
 406                                         *((__be32 *)RTA_DATA(rt_attr)));
 407                                 break;
 408                         case NDA_LLADDR:
 409                                 sprintf(mac, "%lld",
 410                                         *((__be64 *)RTA_DATA(rt_attr)));
 411                                 break;
 412                         default:
 413                                 break;
 414                         }
 415                 }
 416                 arp_entry.dst = atoi(dsts);
 417                 arp_entry.mac = atol(mac);
 418                 printf("%x\t\t%llx\n", arp_entry.dst, arp_entry.mac);
 419                 if (ndm_family == AF_INET) {
 420                         if (bpf_map_lookup_elem(exact_match_map_fd,
 421                                                 &arp_entry.dst,
 422                                                 &direct_entry) == 0) {
 423                                 if (nh->nlmsg_type == RTM_DELNEIGH) {
 424                                         direct_entry.arp.dst = 0;
 425                                         direct_entry.arp.mac = 0;
 426                                 } else if (nh->nlmsg_type == RTM_NEWNEIGH) {
 427                                         direct_entry.arp.dst = arp_entry.dst;
 428                                         direct_entry.arp.mac = arp_entry.mac;
 429                                 }
 430                                 assert(bpf_map_update_elem(exact_match_map_fd,
 431                                                            &arp_entry.dst,
 432                                                            &direct_entry, 0
 433                                                            ) == 0);
 434                                 memset(&direct_entry, 0, sizeof(direct_entry));
 435                         }
 436                         if (nh->nlmsg_type == RTM_DELNEIGH) {
 437                                 assert(bpf_map_delete_elem(arp_table_map_fd,
 438                                                            &arp_entry.dst) == 0);
 439                         } else if (nh->nlmsg_type == RTM_NEWNEIGH) {
 440                                 assert(bpf_map_update_elem(arp_table_map_fd,
 441                                                            &arp_entry.dst,
 442                                                            &arp_entry.mac, 0
 443                                                            ) == 0);
 444                         }
 445                 }
 446                 memset(&arp_entry, 0, sizeof(arp_entry));
 447                 memset(dsts, 0, sizeof(dsts));
 448         }
 449 }
 450
 451 /* Function to read the existing arp table  when the process is launched*/
 452 static int get_arp_table(int rtm_family)
 453 {
 454         struct sockaddr_nl sa;
 455         struct nlmsghdr *nh;
 456         int sock, seq = 0;
 457         struct msghdr msg;
 458         struct iovec iov;
 459         int ret = 0;
 460         int nll;
 461         struct {
 462                 struct nlmsghdr nl;
 463                 struct ndmsg rt;
 464                 char buf[8192];
 465         } req;
 466
 467         sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 468         if (sock < 0) {
 469                 printf("open netlink socket: %s\n", strerror(errno));
 470                 return -1;
 471         }
 472         memset(&sa, 0, sizeof(sa));
 473         sa.nl_family = AF_NETLINK;
 474         if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
 475                 printf("bind to netlink: %s\n", strerror(errno));
 476                 ret = -1;
 477                 goto cleanup;
 478         }
 479         memset(&req, 0, sizeof(req));
 480         req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 481         req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
 482         req.nl.nlmsg_type = RTM_GETNEIGH;
 483         req.rt.ndm_state = NUD_REACHABLE;
 484         req.rt.ndm_family = rtm_family;
 485         req.nl.nlmsg_pid = 0;
 486         req.nl.nlmsg_seq = ++seq;
 487         memset(&msg, 0, sizeof(msg));
 488         iov.iov_base = (void *)&req.nl;
 489         iov.iov_len = req.nl.nlmsg_len;
 490         msg.msg_iov = &iov;
 491         msg.msg_iovlen = 1;
 492         ret = sendmsg(sock, &msg, 0);
 493         if (ret < 0) {
 494                 printf("send to netlink: %s\n", strerror(errno));
 495                 ret = -1;
 496                 goto cleanup;
 497         }
 498         memset(buf, 0, sizeof(buf));
 499         nll = recv_msg(sa, sock);
 500         if (nll < 0) {
 501                 printf("recv from netlink: %s\n", strerror(nll));
 502                 ret = -1;
 503                 goto cleanup;
 504         }
 505         nh = (struct nlmsghdr *)buf;
 506         read_arp(nh, nll);
 507 cleanup:
 508         close(sock);
 509         return ret;
 510 }
 511
 512 /* Function to keep track and update changes in route and arp table
 513  * Give regular statistics of packets forwarded
 514  */
 515 static int monitor_route(void)
 516 {
 517         unsigned int nr_cpus = bpf_num_possible_cpus();
 518         const unsigned int nr_keys = 256;
 519         struct pollfd fds_route, fds_arp;
 520         __u64 prev[nr_keys][nr_cpus];
 521         struct sockaddr_nl la, lr;
 522         __u64 values[nr_cpus];
 523         struct nlmsghdr *nh;
 524         int nll, ret = 0;
 525         int interval = 5;
 526         __u32 key;
 527         int i;
 528
 529         sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 530         if (sock < 0) {
 531                 printf("open netlink socket: %s\n", strerror(errno));
 532                 return -1;
 533         }
 534
 535         fcntl(sock, F_SETFL, O_NONBLOCK);
 536         memset(&lr, 0, sizeof(lr));
 537         lr.nl_family = AF_NETLINK;
 538         lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
 539         if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {
 540                 printf("bind to netlink: %s\n", strerror(errno));
 541                 ret = -1;
 542                 goto cleanup;
 543         }
 544         fds_route.fd = sock;
 545         fds_route.events = POLL_IN;
 546
 547         sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 548         if (sock_arp < 0) {
 549                 printf("open netlink socket: %s\n", strerror(errno));
 550                 return -1;
 551         }
 552
 553         fcntl(sock_arp, F_SETFL, O_NONBLOCK);
 554         memset(&la, 0, sizeof(la));
 555         la.nl_family = AF_NETLINK;
 556         la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;
 557         if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) {
 558                 printf("bind to netlink: %s\n", strerror(errno));
 559                 ret = -1;
 560                 goto cleanup;
 561         }
 562         fds_arp.fd = sock_arp;
 563         fds_arp.events = POLL_IN;
 564
 565         memset(prev, 0, sizeof(prev));
 566         do {
 567                 signal(SIGINT, close_and_exit);
 568                 signal(SIGTERM, close_and_exit);
 569
 570                 sleep(interval);
 571                 for (key = 0; key < nr_keys; key++) {
 572                         __u64 sum = 0;
 573
 574                         assert(bpf_map_lookup_elem(rxcnt_map_fd,
 575                                                    &key, values) == 0);
 576                         for (i = 0; i < nr_cpus; i++)
 577                                 sum += (values[i] - prev[key][i]);
 578                         if (sum)
 579                                 printf("proto %u: %10llu pkt/s\n",
 580                                        key, sum / interval);
 581                         memcpy(prev[key], values, sizeof(values));
 582                 }
 583
 584                 memset(buf, 0, sizeof(buf));
 585                 if (poll(&fds_route, 1, 3) == POLL_IN) {
 586                         nll = recv_msg(lr, sock);
 587                         if (nll < 0) {
 588                                 printf("recv from netlink: %s\n", strerror(nll));
 589                                 ret = -1;
 590                                 goto cleanup;
 591                         }
 592
 593                         nh = (struct nlmsghdr *)buf;
 594                         printf("Routing table updated.\n");
 595                         read_route(nh, nll);
 596                 }
 597                 memset(buf, 0, sizeof(buf));
 598                 if (poll(&fds_arp, 1, 3) == POLL_IN) {
 599                         nll = recv_msg(la, sock_arp);
 600                         if (nll < 0) {
 601                                 printf("recv from netlink: %s\n", strerror(nll));
 602                                 ret = -1;
 603                                 goto cleanup;
 604                         }
 605
 606                         nh = (struct nlmsghdr *)buf;
 607                         read_arp(nh, nll);
 608                 }
 609
 610         } while (1);
 611 cleanup:
 612         close(sock);
 613         return ret;
 614 }
 615
 616 static void usage(const char *prog)
 617 {
 618         fprintf(stderr,
 619                 "%s: %s [OPTS] interface name list\n\n"
 620                 "OPTS:\n"
 621                 "    -S    use skb-mode\n"
 622                 "    -F    force loading prog\n",
 623                 __func__, prog);
 624 }
 625
 626 int main(int ac, char **argv)
 627 {
 628         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 629         struct bpf_prog_load_attr prog_load_attr = {
 630                 .prog_type      = BPF_PROG_TYPE_XDP,
 631         };
 632         struct bpf_prog_info info = {};
 633         __u32 info_len = sizeof(info);
 634         const char *optstr = "SF";
 635         struct bpf_object *obj;
 636         char filename[256];
 637         char **ifname_list;
 638         int prog_fd, opt;
 639         int err, i = 1;
 640
 641         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 642         prog_load_attr.file = filename;
 643
 644         total_ifindex = ac - 1;
 645         ifname_list = (argv + 1);
 646
 647         while ((opt = getopt(ac, argv, optstr)) != -1) {
 648                 switch (opt) {
 649                 case 'S':
 650                         flags |= XDP_FLAGS_SKB_MODE;
 651                         total_ifindex--;
 652                         ifname_list++;
 653                         break;
 654                 case 'F':
 655                         flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
 656                         total_ifindex--;
 657                         ifname_list++;
 658                         break;
 659                 default:
 660                         usage(basename(argv[0]));
 661                         return 1;
 662                 }
 663         }
 664
 665         if (optind == ac) {
 666                 usage(basename(argv[0]));
 667                 return 1;
 668         }
 669
 670         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
 671                 perror("setrlimit(RLIMIT_MEMLOCK)");
 672                 return 1;
 673         }
 674
 675         if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 676                 return 1;
 677
 678         printf("\n**************loading bpf file*********************\n\n\n");
 679         if (!prog_fd) {
 680                 printf("bpf_prog_load_xattr: %s\n", strerror(errno));
 681                 return 1;
 682         }
 683
 684         lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map");
 685         rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
 686         arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table");
 687         exact_match_map_fd = bpf_object__find_map_fd_by_name(obj,
 688                                                              "exact_match");
 689         tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
 690         if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 ||
 691             exact_match_map_fd < 0 || tx_port_map_fd < 0) {
 692                 printf("bpf_object__find_map_fd_by_name failed\n");
 693                 return 1;
 694         }
 695
 696         ifindex_list = (int *)calloc(total_ifindex, sizeof(int *));
 697         for (i = 0; i < total_ifindex; i++) {
 698                 ifindex_list[i] = if_nametoindex(ifname_list[i]);
 699                 if (!ifindex_list[i]) {
 700                         printf("Couldn't translate interface name: %s",
 701                                strerror(errno));
 702                         return 1;
 703                 }
 704         }
 705         prog_id_list = (__u32 *)calloc(total_ifindex, sizeof(__u32 *));
 706         for (i = 0; i < total_ifindex; i++) {
 707                 if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) {
 708                         printf("link set xdp fd failed\n");
 709                         int recovery_index = i;
 710
 711                         for (i = 0; i < recovery_index; i++)
 712                                 bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
 713
 714                         return 1;
 715                 }
 716                 err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
 717                 if (err) {
 718                         printf("can't get prog info - %s\n", strerror(errno));
 719                         return err;
 720                 }
 721                 prog_id_list[i] = info.id;
 722                 memset(&info, 0, sizeof(info));
 723                 printf("Attached to %d\n", ifindex_list[i]);
 724         }
 725         signal(SIGINT, int_exit);
 726         signal(SIGTERM, int_exit);
 727
 728         printf("*******************ROUTE TABLE*************************\n\n\n");
 729         get_route_table(AF_INET);
 730         printf("*******************ARP TABLE***************************\n\n\n");
 731         get_arp_table(AF_INET);
 732         if (monitor_route() < 0) {
 733                 printf("Error in receiving route update");
 734                 return 1;
 735         }
 736
 737         return 0;
 738 }