pppoe.c

   1 /*
   2  * Fernando ALVES 2013
   3  * Add functionality "server pppoe" to l2tpns.
   4  * inspiration pppoe.c of accel-ppp
   5  * GPL licenced
   6  */
   7
   8 #include <unistd.h>
   9 #include <assert.h>
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include <stdarg.h>
  13 #include <errno.h>
  14 #include <string.h>
  15 #include <pthread.h>
  16 #include <fcntl.h>
  17 #include <sys/socket.h>
  18 #include <sys/ioctl.h>
  19 #include <net/if.h>
  20 #include <net/ethernet.h>
  21 #include <netpacket/packet.h>
  22 #include <arpa/inet.h>
  23 #include <linux/if_pppox.h>
  24 #include <linux/rtnetlink.h>
  25
  26 #include "l2tpns.h"
  27 #include "cluster.h"
  28 #include "constants.h"
  29 #include "md5.h"
  30 #include "util.h"
  31
  32 int pppoediscfd = -1;
  33 int pppoesessfd = -1;
  34
  35 static uint8_t bc_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  36
  37 /* PPPoE codes */
  38 #define CODE_PADI           0x09
  39 #define CODE_PADO           0x07
  40 #define CODE_PADR           0x19
  41 #define CODE_PADS           0x65
  42 #define CODE_PADT           0xA7
  43 #define CODE_SESS           0x00
  44
  45 /* PPPoE Tags */
  46 #define TAG_END_OF_LIST        0x0000
  47 #define TAG_SERVICE_NAME       0x0101
  48 #define TAG_AC_NAME            0x0102
  49 #define TAG_HOST_UNIQ          0x0103
  50 #define TAG_AC_COOKIE          0x0104
  51 #define TAG_VENDOR_SPECIFIC    0x0105
  52 #define TAG_RELAY_SESSION_ID   0x0110
  53 #define TAG_SERVICE_NAME_ERROR 0x0201
  54 #define TAG_AC_SYSTEM_ERROR    0x0202
  55 #define TAG_GENERIC_ERROR      0x0203
  56
  57 static char *code_pad[] = {
  58         "PADI",
  59         "PADO",
  60         "PADR",
  61         "PADS",
  62         "PADT",
  63         "SESS",
  64         NULL
  65 };
  66
  67 enum
  68 {
  69         INDEX_PADI = 0,
  70         INDEX_PADO,
  71         INDEX_PADR,
  72         INDEX_PADS,
  73         INDEX_PADT,
  74         INDEX_SESS
  75 };
  76
  77 // set up pppoe discovery socket
  78 static void init_pppoe_disc(void)
  79 {
  80         int on = 1;
  81         struct ifreq ifr;
  82         struct sockaddr_ll sa;
  83
  84         memset(&ifr, 0, sizeof(ifr));
  85         memset(&sa, 0, sizeof(sa));
  86
  87         pppoediscfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_PPP_DISC));
  88         if (pppoediscfd < 0)
  89         {
  90                 LOG(0, 0, 0, "Error pppoe: socket: %s\n", strerror(errno));
  91                 exit(1);
  92         }
  93
  94         fcntl(pppoediscfd, F_SETFD, fcntl(pppoediscfd, F_GETFD) | FD_CLOEXEC);
  95
  96         if (setsockopt(pppoediscfd, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)))
  97         {
  98                 LOG(0, 0, 0, "Error pppoe: setsockopt(SO_BROADCAST): %s\n", strerror(errno));
  99                 exit(1);
 100         }
 101
 102         assert(strlen(ifr.ifr_name) < sizeof(config->pppoe_if_to_bind) - 1);
 103         if (*config->pppoe_if_to_bind)
 104                 strncpy(ifr.ifr_name, config->pppoe_if_to_bind, IFNAMSIZ);
 105
 106         if (ioctl(pppoediscfd, SIOCGIFHWADDR, &ifr))
 107         {
 108                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFHWADDR): %s\n", strerror(errno));
 109                 exit(1);
 110         }
 111
 112         if ((ifr.ifr_hwaddr.sa_data[0] & 1) != 0)
 113         {
 114                 LOG(0, 0, 0, "Error pppoe: interface %s has not unicast address\n", config->pppoe_if_to_bind);
 115                 exit(1);
 116         }
 117
 118         memcpy(config->pppoe_hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 119
 120         if (ioctl(pppoediscfd, SIOCGIFMTU, &ifr))
 121         {
 122                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFMTU): %s\n", strerror(errno));
 123                 exit(1);
 124         }
 125
 126         if (ifr.ifr_mtu < ETH_DATA_LEN)
 127                 LOG(0, 0, 0, "Error pppoe: interface %s has MTU of %i, should be %i\n", config->pppoe_if_to_bind, ifr.ifr_mtu, ETH_DATA_LEN);
 128
 129         if (ioctl(pppoediscfd, SIOCGIFINDEX, &ifr))
 130         {
 131                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFINDEX): %s\n", strerror(errno));
 132                 exit(1);
 133         }
 134
 135         memset(&sa, 0, sizeof(sa));
 136         sa.sll_family = AF_PACKET;
 137         sa.sll_protocol = htons(ETH_P_PPP_DISC);
 138         sa.sll_ifindex = ifr.ifr_ifindex;
 139
 140         if (bind(pppoediscfd, (struct sockaddr *)&sa, sizeof(sa)))
 141         {
 142                 LOG(0, 0, 0, "Error pppoe: bind: %s\n", strerror(errno));
 143                 exit(1);
 144         }
 145
 146         if (fcntl(pppoediscfd, F_SETFL, O_NONBLOCK))
 147         {
 148                 LOG(0, 0, 0, "Error pppoe: failed to set nonblocking mode: %s\n", strerror(errno));
 149                 exit(1);
 150         }
 151
 152 }
 153
 154 // set up pppoe session socket
 155 static void init_pppoe_sess(void)
 156 {
 157         int on = 1;
 158         struct ifreq ifr;
 159         struct sockaddr_ll sa;
 160
 161         memset(&ifr, 0, sizeof(ifr));
 162         memset(&sa, 0, sizeof(sa));
 163
 164         pppoesessfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_PPP_SES));
 165         if (pppoesessfd < 0)
 166         {
 167                 LOG(0, 0, 0, "Error pppoe: socket: %s\n", strerror(errno));
 168                 exit(1);
 169         }
 170
 171         fcntl(pppoesessfd, F_SETFD, fcntl(pppoesessfd, F_GETFD) | FD_CLOEXEC);
 172
 173         if (setsockopt(pppoesessfd, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)))
 174         {
 175                 LOG(0, 0, 0, "Error pppoe: setsockopt(SO_BROADCAST): %s\n", strerror(errno));
 176                 exit(1);
 177         }
 178
 179         assert(strlen(ifr.ifr_name) < sizeof(config->pppoe_if_to_bind) - 1);
 180         if (*config->pppoe_if_to_bind)
 181                 strncpy(ifr.ifr_name, config->pppoe_if_to_bind, IFNAMSIZ);
 182
 183         if (ioctl(pppoesessfd, SIOCGIFHWADDR, &ifr))
 184         {
 185                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFHWADDR): %s\n", strerror(errno));
 186                 exit(1);
 187         }
 188
 189         if ((ifr.ifr_hwaddr.sa_data[0] & 1) != 0)
 190         {
 191                 LOG(0, 0, 0, "Error pppoe: interface %s has not unicast address\n", config->pppoe_if_to_bind);
 192                 exit(1);
 193         }
 194
 195         memcpy(config->pppoe_hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 196
 197         if (ioctl(pppoesessfd, SIOCGIFMTU, &ifr))
 198         {
 199                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFMTU): %s\n", strerror(errno));
 200                 exit(1);
 201         }
 202
 203         if (ifr.ifr_mtu < ETH_DATA_LEN)
 204                 LOG(0, 0, 0, "Error pppoe: interface %s has MTU of %i, should be %i\n", config->pppoe_if_to_bind, ifr.ifr_mtu, ETH_DATA_LEN);
 205
 206         if (ioctl(pppoesessfd, SIOCGIFINDEX, &ifr))
 207         {
 208                 LOG(0, 0, 0, "Error pppoe: ioctl(SIOCGIFINDEX): %s\n", strerror(errno));
 209                 exit(1);
 210         }
 211
 212         memset(&sa, 0, sizeof(sa));
 213         sa.sll_family = AF_PACKET;
 214         sa.sll_protocol = htons(ETH_P_PPP_SES);
 215         sa.sll_ifindex = ifr.ifr_ifindex;
 216
 217         if (bind(pppoesessfd, (struct sockaddr *)&sa, sizeof(sa)))
 218         {
 219                 LOG(0, 0, 0, "Error pppoe: bind: %s\n", strerror(errno));
 220                 exit(1);
 221         }
 222
 223         if (fcntl(pppoesessfd, F_SETFL, O_NONBLOCK))
 224         {
 225                 LOG(0, 0, 0, "Error pppoe: failed to set nonblocking mode: %s\n", strerror(errno));
 226                 exit(1);
 227         }
 228 }
 229
 230 // set up pppoe discovery/session socket
 231 void init_pppoe(void)
 232 {
 233         tunnelidt t = TUNNEL_ID_PPPOE;
 234
 235         init_pppoe_disc();
 236         init_pppoe_sess();
 237
 238         // Reserve the a pseudo tunnel for pppoe server
 239         if (t > config->cluster_highest_tunnelid)
 240                 config->cluster_highest_tunnelid = t;
 241
 242         memset(&tunnel[t], 0, sizeof(tunnel[t]));
 243         tunnel[t].state = TUNNELOPEN;
 244         STAT(tunnel_created);
 245 }
 246
 247 char * get_string_codepad(uint8_t codepad)
 248 {
 249         char * ptrch = NULL;
 250         switch(codepad)
 251         {
 252                 case CODE_PADI:
 253                 ptrch = code_pad[INDEX_PADI];
 254                 break;
 255
 256                 case CODE_PADO:
 257                 ptrch = code_pad[INDEX_PADO];
 258                 break;
 259
 260                 case CODE_PADR:
 261                 ptrch = code_pad[INDEX_PADR];
 262                 break;
 263
 264                 case CODE_PADS:
 265                 ptrch = code_pad[INDEX_PADS];
 266                 break;
 267
 268                 case CODE_PADT:
 269                 ptrch = code_pad[INDEX_PADT];
 270                 break;
 271
 272                 case CODE_SESS:
 273                 ptrch = code_pad[INDEX_SESS];
 274                 break;
 275         }
 276
 277         return ptrch;
 278 }
 279
 280 static uint8_t * setup_header(uint8_t *pack, const uint8_t *src, const uint8_t *dst, int code, uint16_t sid, uint16_t h_proto)
 281 {
 282         uint8_t * p;
 283
 284         // 14 bytes ethernet Header + 6 bytes header pppoe
 285         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 286         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 287
 288         memcpy(ethhdr->h_source, src, ETH_ALEN);
 289         memcpy(ethhdr->h_dest, dst, ETH_ALEN);
 290         ethhdr->h_proto = htons(h_proto);
 291
 292         hdr->ver = 1;
 293         hdr->type = 1;
 294         hdr->code = code;
 295         hdr->sid = htons(sid);
 296         hdr->length = 0;
 297
 298         p = (uint8_t *)(pack + ETH_HLEN + sizeof(*hdr));
 299
 300         return p;
 301 }
 302
 303 static void add_tag(uint8_t *pack, int type, const uint8_t *data, int len)
 304 {
 305         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 306         struct pppoe_tag *tag = (struct pppoe_tag *)(pack + ETH_HLEN + sizeof(*hdr) + ntohs(hdr->length));
 307
 308         tag->tag_type = htons(type);
 309         tag->tag_len = htons(len);
 310         memcpy(tag->tag_data, data, len);
 311
 312         hdr->length = htons(ntohs(hdr->length) + sizeof(*tag) + len);
 313 }
 314
 315 static void add_tag2(uint8_t *pack, const struct pppoe_tag *t)
 316 {
 317         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 318         struct pppoe_tag *tag = (struct pppoe_tag *)(pack + ETH_HLEN + sizeof(*hdr) + ntohs(hdr->length));
 319
 320         memcpy(tag, t, sizeof(*t) + ntohs(t->tag_len));
 321
 322         hdr->length = htons(ntohs(hdr->length) + sizeof(*tag) + ntohs(t->tag_len));
 323 }
 324
 325 static void pppoe_disc_send(const uint8_t *pack)
 326 {
 327         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 328         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 329         int n, s;
 330
 331         s = ETH_HLEN + sizeof(*hdr) + ntohs(hdr->length);
 332
 333         LOG(3, 0, 0, "SENT pppoe_disc: Code %s to %s\n", get_string_codepad(hdr->code), fmtMacAddr(ethhdr->h_dest));
 334         LOG_HEX(5, "pppoe_disc_send", pack, s);
 335
 336         n = write(pppoediscfd, pack, s);
 337         if (n < 0 )
 338                 LOG(0, 0, 0, "pppoe: write: %s\n", strerror(errno));
 339         else if (n != s) {
 340                 LOG(0, 0, 0, "pppoe: short write %i/%i\n", n,s);
 341         }
 342 }
 343
 344 void pppoe_sess_send(const uint8_t *pack, uint16_t l, tunnelidt t)
 345 {
 346         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 347         int n;
 348         uint16_t sizeppp;
 349         sessionidt s;
 350
 351         if (t != TUNNEL_ID_PPPOE)
 352         {
 353                 LOG(3, 0, t, "ERROR pppoe_sess_send: Tunnel %d is not a tunnel pppoe\n", t);
 354                 return;
 355         }
 356
 357         s = ntohs(hdr->sid);
 358         if (session[s].tunnel != t)
 359         {
 360                 LOG(3, s, t, "ERROR pppoe_sess_send: Session is not a session pppoe\n");
 361                 return;
 362         }
 363
 364         if (l < (ETH_HLEN + sizeof(*hdr) + 3))
 365         {
 366                 LOG(0, s, t, "ERROR pppoe_sess_send: packet too small for pppoe sent (size=%d)\n", l);
 367                 return;
 368         }
 369
 370         // recalculate the ppp frame length
 371         sizeppp = l - (ETH_HLEN + sizeof(*hdr));
 372         hdr->length = htons(sizeppp);
 373
 374         LOG_HEX(5, "pppoe_sess_send", pack, l);
 375
 376         n = write(pppoesessfd, pack, l);
 377         if (n < 0 )
 378                 LOG(0, s, t, "pppoe_sess_send: write: %s\n", strerror(errno));
 379         else if (n != l)
 380                 LOG(0, s, t, "pppoe_sess_send: short write %i/%i\n", n,l);
 381 }
 382
 383 static void pppoe_send_err(const uint8_t *addr, const struct pppoe_tag *host_uniq, const struct pppoe_tag *relay_sid, int code, int tag_type)
 384 {
 385         uint8_t pack[ETHER_MAX_LEN];
 386
 387         setup_header(pack, config->pppoe_hwaddr, addr, code, 0, ETH_P_PPP_DISC);
 388
 389         add_tag(pack, TAG_AC_NAME, (uint8_t *)config->pppoe_ac_name, strlen(config->pppoe_ac_name));
 390         add_tag(pack, tag_type, NULL, 0);
 391
 392         if (host_uniq)
 393                 add_tag2(pack, host_uniq);
 394
 395         if (relay_sid)
 396                 add_tag2(pack, relay_sid);
 397
 398         pppoe_disc_send(pack);
 399 }
 400
 401 // generate cookie
 402 static void pppoe_gen_cookie(const uint8_t *serv_hwaddr, const uint8_t *client_hwaddr, uint8_t *out)
 403 {
 404         MD5_CTX ctx;
 405
 406         MD5_Init(&ctx);
 407         MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
 408         MD5_Update(&ctx, (void *) serv_hwaddr, ETH_ALEN);
 409         MD5_Update(&ctx, (void *) client_hwaddr, ETH_ALEN);
 410         MD5_Final(out, &ctx);
 411 }
 412
 413 // check cookie
 414 static int pppoe_check_cookie(const uint8_t *serv_hwaddr, const uint8_t *client_hwaddr, uint8_t *cookie)
 415 {
 416         hasht hash;
 417
 418         pppoe_gen_cookie(serv_hwaddr, client_hwaddr, hash);
 419
 420         return memcmp(hash, cookie, 16);
 421 }
 422
 423 static void pppoe_send_PADO(const uint8_t *addr, const struct pppoe_tag *host_uniq, const struct pppoe_tag *relay_sid, const struct pppoe_tag *service_name)
 424 {
 425         uint8_t pack[ETHER_MAX_LEN];
 426         hasht hash;
 427
 428         setup_header(pack, config->pppoe_hwaddr, addr, CODE_PADO, 0, ETH_P_PPP_DISC);
 429
 430         add_tag(pack, TAG_AC_NAME, (uint8_t *)config->pppoe_ac_name, strlen(config->pppoe_ac_name));
 431
 432         if (service_name)
 433                 add_tag2(pack, service_name);
 434
 435         pppoe_gen_cookie(config->pppoe_hwaddr, addr, hash);
 436         add_tag(pack, TAG_AC_COOKIE, hash, 16);
 437
 438         if (host_uniq)
 439                 add_tag2(pack, host_uniq);
 440
 441         if (relay_sid)
 442                 add_tag2(pack, relay_sid);
 443
 444         pppoe_disc_send(pack);
 445 }
 446
 447 static void pppoe_send_PADS(uint16_t sid, const uint8_t *addr, const struct pppoe_tag *host_uniq, const struct pppoe_tag *relay_sid, const struct pppoe_tag *service_name)
 448 {
 449         uint8_t pack[ETHER_MAX_LEN];
 450
 451         setup_header(pack, config->pppoe_hwaddr, addr, CODE_PADS, sid, ETH_P_PPP_DISC);
 452
 453         add_tag(pack, TAG_AC_NAME, (uint8_t *)config->pppoe_ac_name, strlen(config->pppoe_ac_name));
 454
 455         add_tag2(pack, service_name);
 456
 457         if (host_uniq)
 458                 add_tag2(pack, host_uniq);
 459
 460         if (relay_sid)
 461                 add_tag2(pack, relay_sid);
 462
 463         pppoe_disc_send(pack);
 464 }
 465
 466 static void pppoe_send_PADT(uint16_t sid)
 467 {
 468         uint8_t pack[ETHER_MAX_LEN];
 469
 470         setup_header(pack, config->pppoe_hwaddr, session[sid].src_hwaddr, CODE_PADT, sid, ETH_P_PPP_DISC);
 471
 472         add_tag(pack, TAG_AC_NAME, (uint8_t *)config->pppoe_ac_name, strlen(config->pppoe_ac_name));
 473
 474         LOG(3, sid, session[sid].tunnel, "pppoe: Sent PADT\n");
 475
 476         pppoe_disc_send(pack);
 477 }
 478
 479 void pppoe_shutdown_session(sessionidt s)
 480 {
 481
 482         if (session[s].tunnel != TUNNEL_ID_PPPOE)
 483         {
 484                 LOG(3, s, session[s].tunnel, "ERROR pppoe_shutdown_session: Session is not a session pppoe\n");
 485                 return;
 486         }
 487
 488         pppoe_send_PADT(s);
 489 }
 490
 491 static void pppoe_recv_PADI(uint8_t *pack, int size)
 492 {
 493         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 494         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 495         struct pppoe_tag *tag;
 496         struct pppoe_tag *host_uniq_tag = NULL;
 497         struct pppoe_tag *relay_sid_tag = NULL;
 498         struct pppoe_tag *service_name_tag = NULL;
 499         int n, service_match = 0;
 500         int len;
 501
 502         if (hdr->sid)
 503                 return;
 504
 505         len = ntohs(hdr->length);
 506         for (n = 0; n < len; n += sizeof(*tag) + ntohs(tag->tag_len)) {
 507                 tag = (struct pppoe_tag *)(pack + ETH_HLEN + sizeof(*hdr) + n);
 508                 if (n + sizeof(*tag) + ntohs(tag->tag_len) > len)
 509                         return;
 510                 switch (ntohs(tag->tag_type)) {
 511                         case TAG_END_OF_LIST:
 512                                 break;
 513                         case TAG_SERVICE_NAME:
 514                                 if (*config->pppoe_service_name && tag->tag_len)
 515                                 {
 516                                         if (ntohs(tag->tag_len) != strlen(config->pppoe_service_name))
 517                                                 break;
 518                                         if (memcmp(tag->tag_data, config->pppoe_service_name, ntohs(tag->tag_len)))
 519                                                 break;
 520                                         service_match = 1;
 521                                 }
 522                                 else
 523                                 {
 524                                         service_name_tag = tag;
 525                                         service_match = 1;
 526                                 }
 527                                 break;
 528                         case TAG_HOST_UNIQ:
 529                                 host_uniq_tag = tag;
 530                                 break;
 531                         case TAG_RELAY_SESSION_ID:
 532                                 relay_sid_tag = tag;
 533                                 break;
 534                 }
 535         }
 536
 537         if (!service_match)
 538         {
 539                 LOG(3, 0, 0, "pppoe: discarding PADI packet (Service-Name mismatch)\n");
 540                 return;
 541         }
 542
 543         pppoe_send_PADO(ethhdr->h_source, host_uniq_tag, relay_sid_tag, service_name_tag);
 544 }
 545
 546 static void pppoe_recv_PADR(uint8_t *pack, int size)
 547 {
 548         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 549         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 550         struct pppoe_tag *tag;
 551         struct pppoe_tag *host_uniq_tag = NULL;
 552         struct pppoe_tag *relay_sid_tag = NULL;
 553         struct pppoe_tag *ac_cookie_tag = NULL;
 554         struct pppoe_tag *service_name_tag = NULL;
 555         int n, service_match = 0;
 556         uint16_t sid;
 557
 558         if (!memcmp(ethhdr->h_dest, bc_addr, ETH_ALEN))
 559         {
 560                 LOG(1, 0, 0, "Rcv pppoe: discard PADR (destination address is broadcast)\n");
 561                 return;
 562         }
 563
 564         if (hdr->sid)
 565         {
 566                 LOG(1, 0, 0, "Rcv pppoe: discarding PADR packet (sid is not zero)\n");
 567                 return;
 568         }
 569
 570         for (n = 0; n < ntohs(hdr->length); n += sizeof(*tag) + ntohs(tag->tag_len))
 571         {
 572                 tag = (struct pppoe_tag *)(pack + ETH_HLEN + sizeof(*hdr) + n);
 573                 switch (ntohs(tag->tag_type))
 574                 {
 575                         case TAG_END_OF_LIST:
 576                                 break;
 577                         case TAG_SERVICE_NAME:
 578                                 service_name_tag = tag;
 579                                 if (tag->tag_len == 0)
 580                                         service_match = 1;
 581                                 else if (*config->pppoe_service_name)
 582                                 {
 583                                         if (ntohs(tag->tag_len) != strlen(config->pppoe_service_name))
 584                                                 break;
 585                                         if (memcmp(tag->tag_data, config->pppoe_service_name, ntohs(tag->tag_len)))
 586                                                 break;
 587                                         service_match = 1;
 588                                 }
 589                                 else
 590                                 {
 591                                         service_match = 1;
 592                                 }
 593                                 break;
 594                         case TAG_HOST_UNIQ:
 595                                 host_uniq_tag = tag;
 596                                 break;
 597                         case TAG_AC_COOKIE:
 598                                 ac_cookie_tag = tag;
 599                                 break;
 600                         case TAG_RELAY_SESSION_ID:
 601                                 relay_sid_tag = tag;
 602                                 break;
 603                 }
 604         }
 605
 606         if (!service_match)
 607         {
 608                 LOG(3, 0, 0, "pppoe: Service-Name mismatch\n");
 609                 pppoe_send_err(ethhdr->h_source, host_uniq_tag, relay_sid_tag, CODE_PADS, TAG_SERVICE_NAME_ERROR);
 610                 return;
 611         }
 612
 613         if (!ac_cookie_tag)
 614         {
 615                 LOG(3, 0, 0, "pppoe: discard PADR packet (no AC-Cookie tag present)\n");
 616                 return;
 617         }
 618
 619         if (ntohs(ac_cookie_tag->tag_len) != 16)
 620         {
 621                 LOG(3, 0, 0, "pppoe: discard PADR packet (incorrect AC-Cookie tag length)\n");
 622                 return;
 623         }
 624
 625         if (pppoe_check_cookie(ethhdr->h_dest, ethhdr->h_source, (uint8_t *) ac_cookie_tag->tag_data))
 626         {
 627                 LOG(3, 0, 0, "pppoe: discard PADR packet (incorrect AC-Cookie)\n");
 628                 return;
 629         }
 630
 631         sid = sessionfree;
 632         sessionfree = session[sid].next;
 633         memset(&session[sid], 0, sizeof(session[0]));
 634
 635         if (sid > config->cluster_highest_sessionid)
 636                 config->cluster_highest_sessionid = sid;
 637
 638         session[sid].opened = time_now;
 639         session[sid].tunnel = TUNNEL_ID_PPPOE;
 640         session[sid].last_packet = session[sid].last_data = time_now;
 641
 642         //strncpy(session[sid].called, called, sizeof(session[sid].called) - 1);
 643         //strncpy(session[sid].calling, calling, sizeof(session[sid].calling) - 1);
 644
 645         session[sid].ppp.phase = Establish;
 646         session[sid].ppp.lcp = Starting;
 647
 648         session[sid].magic = time_now; // set magic number
 649         session[sid].mru = PPPoE_MRU; // default
 650
 651         // start LCP
 652         sess_local[sid].lcp_authtype = config->radius_authprefer;
 653         sess_local[sid].ppp_mru = MRU;
 654
 655         // Set multilink options before sending initial LCP packet
 656         sess_local[sid].mp_mrru = 1614;
 657         sess_local[sid].mp_epdis = ntohl(config->iftun_address ? config->iftun_address : my_address);
 658
 659         memcpy(session[sid].src_hwaddr, ethhdr->h_source, ETH_ALEN);
 660         pppoe_send_PADS(sid, ethhdr->h_source, host_uniq_tag, relay_sid_tag, service_name_tag);
 661
 662         sendlcp(sid, session[sid].tunnel);
 663         change_state(sid, lcp, RequestSent);
 664
 665 }
 666
 667 static void pppoe_recv_PADT(uint8_t *pack)
 668 {
 669         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 670         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 671
 672         if (!memcmp(ethhdr->h_dest, bc_addr, ETH_ALEN))
 673         {
 674                 LOG(3, 0, 0, "pppoe: discard PADT (destination address is broadcast)\n");
 675                 return;
 676         }
 677
 678         if (hdr->sid)
 679         {
 680                 if ((hdr->sid < MAXSESSION) && (session[hdr->sid].tunnel == TUNNEL_ID_PPPOE))
 681                         sessionshutdown(hdr->sid, "Client shutdown", CDN_ADMIN_DISC, 0);
 682         }
 683 }
 684
 685 // fill in a PPPOE message with a PPP frame,
 686 // returns start of PPP frame
 687 uint8_t *pppoe_makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t,
 688                                                 uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits)
 689 {
 690         uint16_t type = mtype;
 691         uint8_t *start = b;
 692         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(b + ETH_HLEN);
 693
 694         if (t != TUNNEL_ID_PPPOE)
 695                 return NULL;
 696
 697         if (size < 28) // Need more space than this!!
 698         {
 699                 LOG(0, s, t, "pppoe_makeppp buffer too small for pppoe header (size=%d)\n", size);
 700                 return NULL;
 701         }
 702
 703         // 14 bytes ethernet Header + 6 bytes header pppoe
 704         b = setup_header(b, config->pppoe_hwaddr, session[s].src_hwaddr, CODE_SESS, s, ETH_P_PPP_SES);
 705
 706         // Check whether this session is part of multilink
 707         if (bid)
 708         {
 709                 if (bundle[bid].num_of_links > 1)
 710                         type = PPPMP; // Change PPP message type to the PPPMP
 711                 else
 712                         bid = 0;
 713         }
 714
 715         *(uint16_t *) b = htons(type);
 716         b += 2;
 717         hdr->length += 2;
 718
 719         if (bid)
 720         {
 721                 // Set the sequence number and (B)egin (E)nd flags
 722                 if (session[s].mssf)
 723                 {
 724                         // Set the multilink bits
 725                         uint16_t bits_send = mp_bits;
 726                         *(uint16_t *) b = htons((bundle[bid].seq_num_t & 0x0FFF)|bits_send);
 727                         b += 2;
 728                         hdr->length += 2;
 729                 }
 730                 else
 731                 {
 732                         *(uint32_t *) b = htonl(bundle[bid].seq_num_t);
 733                         // Set the multilink bits
 734                         *b = mp_bits;
 735                         b += 4;
 736                         hdr->length += 4;
 737                 }
 738
 739                 bundle[bid].seq_num_t++;
 740
 741                 // Add the message type if this fragment has the begin bit set
 742                 if (mp_bits & MP_BEGIN)
 743                 {
 744                         //*b++ = mtype; // The next two lines are instead of this
 745                         *(uint16_t *) b = htons(mtype); // Message type
 746                         b += 2;
 747                         hdr->length += 2;
 748                 }
 749         }
 750
 751         if ((b - start) + l > size)
 752         {
 753                 LOG(0, s, t, "pppoe_makeppp would overflow buffer (size=%d, header+payload=%td)\n", size, (b - start) + l);
 754                 return NULL;
 755         }
 756
 757         // Copy the payload
 758         if (p && l)
 759         {
 760                 memcpy(b, p, l);
 761                 hdr->length += l;
 762         }
 763
 764         return b;
 765 }
 766
 767 // fill in a PPPOE message with a PPP frame,
 768 // returns start of PPP frame
 769 //(note: THIS ROUTINE WRITES TO p[-28]).
 770 uint8_t *opt_pppoe_makeppp(uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits)
 771 {
 772         uint16_t type = mtype;
 773         uint16_t hdrlen = l;
 774         uint8_t *b = p;
 775         struct pppoe_hdr *hdr;
 776
 777         if (t != TUNNEL_ID_PPPOE)
 778                 return NULL;
 779
 780         // Check whether this session is part of multilink
 781         if (bid)
 782         {
 783                 if (bundle[bid].num_of_links > 1)
 784                         type = PPPMP; // Change PPP message type to the PPPMP
 785                 else
 786                         bid = 0;
 787         }
 788
 789         if (bid)
 790         {
 791                 // Add the message type if this fragment has the begin bit set
 792                 if (mp_bits & MP_BEGIN)
 793                 {
 794                         b -= 2;
 795                         *(uint16_t *) b = htons(mtype); // Message type
 796                 }
 797
 798                 // Set the sequence number and (B)egin (E)nd flags
 799                 if (session[s].mssf)
 800                 {
 801                         // Set the multilink bits
 802                         uint16_t bits_send = mp_bits;
 803                         b -= 2;
 804                         *(uint16_t *) b = htons((bundle[bid].seq_num_t & 0x0FFF)|bits_send);
 805                 }
 806                 else
 807                 {
 808                         b -= 4;
 809                         *(uint32_t *) b = htonl(bundle[bid].seq_num_t);
 810                         // Set the multilink bits
 811                         *b = mp_bits;
 812                 }
 813
 814                 bundle[bid].seq_num_t++;
 815         }
 816
 817         b -= 2;
 818         *(uint16_t *) b = htons(type);
 819
 820         // Size ppp packet
 821         hdrlen += (p - b);
 822
 823         // 14 bytes ethernet Header + 6 bytes header pppoe
 824         b -= (ETH_HLEN + sizeof(*hdr));
 825         setup_header(b, config->pppoe_hwaddr, session[s].src_hwaddr, CODE_SESS, s, ETH_P_PPP_SES);
 826         hdr = (struct pppoe_hdr *)(b + ETH_HLEN);
 827         // Store length on header pppoe
 828         hdr->length = hdrlen;
 829
 830         return b;
 831 }
 832
 833 // pppoe discovery recv data
 834 void process_pppoe_disc(uint8_t *pack, int size)
 835 {
 836         struct ethhdr *ethhdr = (struct ethhdr *)pack;
 837         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 838
 839         LOG(3, 0, 0, "RCV pppoe_disc: Code %s from %s\n", get_string_codepad(hdr->code), fmtMacAddr(ethhdr->h_source));
 840         LOG_HEX(5, "PPPOE Disc", pack, size);
 841
 842         if (!config->cluster_iam_master)
 843         {
 844                 if (hdr->code == CODE_PADI)
 845                         return; // Discard because the PADI is received by all (PADI is a broadcast diffusion)
 846
 847                 master_forward_pppoe_packet(pack, size, hdr->code);
 848                 return;
 849         }
 850
 851         if (size < (ETH_HLEN + sizeof(*hdr)))
 852         {
 853                 LOG(1, 0, 0, "Error pppoe_disc: short packet received (%i)\n", size);
 854                 return;
 855         }
 856
 857         if (memcmp(ethhdr->h_dest, bc_addr, ETH_ALEN) && memcmp(ethhdr->h_dest, config->pppoe_hwaddr, ETH_ALEN))
 858         {
 859                 LOG(1, 0, 0, "Error pppoe_disc: h_dest != bc_addr and  h_dest != config->pppoe_hwaddr\n");
 860                 return;
 861         }
 862
 863         if (!memcmp(ethhdr->h_source, bc_addr, ETH_ALEN))
 864         {
 865                 LOG(1, 0, 0, "Error pppoe_disc: discarding packet (source address is broadcast)\n");
 866                 return;
 867         }
 868
 869         if ((ethhdr->h_source[0] & 1) != 0)
 870         {
 871                 LOG(1, 0, 0, "Error pppoe_disc: discarding packet (host address is not unicast)\n");
 872                 return;
 873         }
 874
 875         if (size < ETH_HLEN + sizeof(*hdr) + ntohs(hdr->length))
 876         {
 877                 LOG(1, 0, 0, "Error pppoe_disc: short packet received\n");
 878                 return;
 879         }
 880
 881         if (hdr->ver != 1)
 882         {
 883                 LOG(1, 0, 0, "Error pppoe_disc: discarding packet (unsupported version %i)\n", hdr->ver);
 884                 return;
 885         }
 886
 887         if (hdr->type != 1)
 888         {
 889                 LOG(1, 0, 0, "Error pppoe_disc: discarding packet (unsupported type %i)\n", hdr->type);
 890                 return;
 891         }
 892
 893         switch (hdr->code) {
 894                 case CODE_PADI:
 895                         pppoe_recv_PADI(pack, size);
 896                         break;
 897                 case CODE_PADR:
 898                         pppoe_recv_PADR(pack, size);
 899                         break;
 900                 case CODE_PADT:
 901                         pppoe_recv_PADT(pack);
 902                         break;
 903         }
 904 }
 905
 906 // Forward from pppoe to l2tp remote LNS
 907 static void pppoe_forwardto_session_rmlns(uint8_t *pack, int size, sessionidt sess, uint16_t proto)
 908 {
 909         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
 910         uint16_t lppp = ntohs(hdr->length);
 911         uint16_t ll2tp = lppp + 6;
 912         uint8_t *pppdata = (uint8_t *) hdr->tag;
 913         uint8_t *pl2tp = pppdata - 6;
 914         uint8_t *p = pl2tp;
 915         uint16_t t = 0, s = 0;
 916
 917         s = session[sess].forwardtosession;
 918         if (session[s].forwardtosession != sess)
 919         {
 920                 LOG(3, sess, session[sess].tunnel, "pppoe: Link Session (%u) broken\n", s);
 921                 return;
 922         }
 923
 924         t = session[s].tunnel;
 925         if (t >= MAXTUNNEL)
 926         {
 927                 LOG(1, s, t, "pppoe: Session with invalid tunnel ID\n");
 928                 return;
 929         }
 930
 931         if (!tunnel[t].isremotelns)
 932         {
 933                 LOG(3, sess, session[sess].tunnel, "pppoe: Link Tunnel/Session (%u/%u) broken\n", s, t);
 934                 return;
 935         }
 936
 937         // First word L2TP options (with no options)
 938         *(uint16_t *) p = htons(0x0002);
 939         p += 2;
 940         *(uint16_t *) p = htons(tunnel[t].far); // tunnel
 941         p += 2;
 942         *(uint16_t *) p = htons(session[s].far); // session
 943         p += 2;
 944
 945         if ((proto == PPPIP) || (proto == PPPMP) ||(proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0]))
 946         {
 947                 session[sess].last_packet = session[sess].last_data = time_now;
 948                 // Update STAT IN
 949                 increment_counter(&session[sess].cin, &session[sess].cin_wrap, ll2tp);
 950                 session[sess].cin_delta += ll2tp;
 951                 session[sess].pin++;
 952                 sess_local[sess].cin += ll2tp;
 953                 sess_local[sess].pin++;
 954
 955                 session[s].last_data = time_now;
 956                 // Update STAT OUT
 957                 increment_counter(&session[s].cout, &session[s].cout_wrap, ll2tp); // byte count
 958                 session[s].cout_delta += ll2tp;
 959                 session[s].pout++;
 960                 sess_local[s].cout += ll2tp;
 961                 sess_local[s].pout++;
 962         }
 963         else
 964                 session[sess].last_packet = time_now;
 965
 966         tunnelsend(pl2tp, ll2tp, t); // send it...
 967 }
 968
 969 // Forward from l2tp to pppoe
 970 // (note: THIS ROUTINE WRITES TO pack[-20]).
 971 void pppoe_forwardto_session_pppoe(uint8_t *pack, int size, sessionidt sess, uint16_t proto)
 972 {
 973         uint16_t t = 0, s = 0;
 974         uint16_t lpppoe = size - 2;
 975         uint8_t *p = pack + 2; // First word L2TP options
 976
 977         LOG(5, sess, session[sess].tunnel, "Forwarding data session to pppoe session %u\n", session[sess].forwardtosession);
 978
 979         s = session[sess].forwardtosession;
 980         t = session[s].tunnel;
 981
 982         if (*pack & 0x40)
 983         {       // length
 984                 p += 2;
 985                 lpppoe -= 2;
 986         }
 987
 988         *(uint16_t *) p = htons(tunnel[t].far); // tunnel
 989         p += 2;
 990         *(uint16_t *) p = htons(session[s].far); // session
 991         p += 2;
 992         lpppoe -= 4;
 993
 994         if (*pack & 0x08)
 995         {   // ns/nr
 996                 *(uint16_t *) p = htons(tunnel[t].ns); // sequence
 997                 p += 2;
 998                 *(uint16_t *) p = htons(tunnel[t].nr); // sequence
 999                 p += 2;
1000                 lpppoe -= 4;
1001         }
1002
1003         if (lpppoe > 2 && p[0] == 0xFF && p[1] == 0x03)
1004         {
1005                 // HDLC address header, discard in pppoe
1006                 p += 2;
1007                 lpppoe -= 2;
1008         }
1009
1010         lpppoe += (ETH_HLEN + sizeof(struct pppoe_hdr));
1011         p -= (ETH_HLEN + sizeof(struct pppoe_hdr));
1012
1013         // 14 bytes ethernet Header + 6 bytes header pppoe
1014         setup_header(p, config->pppoe_hwaddr, session[s].src_hwaddr, CODE_SESS, s, ETH_P_PPP_SES);
1015
1016         if ((proto == PPPIP) || (proto == PPPMP) ||(proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0]))
1017         {
1018                 session[sess].last_packet = session[sess].last_data = time_now;
1019                 // Update STAT IN
1020                 increment_counter(&session[sess].cin, &session[sess].cin_wrap, lpppoe);
1021                 session[sess].cin_delta += lpppoe;
1022                 session[sess].pin++;
1023                 sess_local[sess].cin += lpppoe;
1024                 sess_local[sess].pin++;
1025
1026                 session[s].last_data = time_now;
1027                 // Update STAT OUT
1028                 increment_counter(&session[s].cout, &session[s].cout_wrap, lpppoe); // byte count
1029                 session[s].cout_delta += lpppoe;
1030                 session[s].pout++;
1031                 sess_local[s].cout += lpppoe;
1032                 sess_local[s].pout++;
1033         }
1034         else
1035                 session[sess].last_packet = time_now;
1036
1037         tunnelsend(p, lpppoe, t); // send it....
1038 }
1039
1040 void process_pppoe_sess(uint8_t *pack, int size)
1041 {
1042         //struct ethhdr *ethhdr = (struct ethhdr *)pack;
1043         struct pppoe_hdr *hdr = (struct pppoe_hdr *)(pack + ETH_HLEN);
1044         uint16_t lppp = ntohs(hdr->length);
1045         uint8_t *pppdata = (uint8_t *) hdr->tag;
1046         uint16_t proto, sid, t;
1047
1048         sid = ntohs(hdr->sid);
1049         t = TUNNEL_ID_PPPOE;
1050
1051         LOG_HEX(5, "RCV PPPOE Sess", pack, size);
1052
1053         if (sid >= MAXSESSION)
1054         {
1055                 LOG(0, sid, t, "Received pppoe packet with invalid session ID\n");
1056                 STAT(tunnel_rx_errors);
1057                 return;
1058         }
1059
1060         if (session[sid].tunnel != t)
1061         {
1062                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1063
1064                 LOG(1, sid, t, "ERROR process_pppoe_sess: Session is not a session pppoe\n");
1065                 return;
1066         }
1067
1068         if (hdr->ver != 1)
1069         {
1070                 LOG(3, sid, t, "Error process_pppoe_sess: discarding packet (unsupported version %i)\n", hdr->ver);
1071                 return;
1072         }
1073
1074         if (hdr->type != 1)
1075         {
1076                 LOG(3, sid, t, "Error process_pppoe_sess: discarding packet (unsupported type %i)\n", hdr->type);
1077                 return;
1078         }
1079
1080         if (lppp > 2 && pppdata[0] == 0xFF && pppdata[1] == 0x03)
1081         {       // HDLC address header, discard
1082                 LOG(5, sid, t, "pppoe_sess: HDLC address header, discard\n");
1083                 pppdata += 2;
1084                 lppp -= 2;
1085         }
1086         if (lppp < 2)
1087         {
1088                 LOG(3, sid, t, "Error process_pppoe_sess: Short ppp length %d\n", lppp);
1089                 return;
1090         }
1091         if (*pppdata & 1)
1092         {
1093                 proto = *pppdata++;
1094                 lppp--;
1095         }
1096         else
1097         {
1098                 proto = ntohs(*(uint16_t *) pppdata);
1099                 pppdata += 2;
1100                 lppp -= 2;
1101         }
1102
1103         if (session[sid].forwardtosession)
1104         {       // Must be forwaded to a remote lns tunnel l2tp
1105                 pppoe_forwardto_session_rmlns(pack, size, sid, proto);
1106                 return;
1107         }
1108
1109         if (proto == PPPPAP)
1110         {
1111                 session[sid].last_packet = time_now;
1112                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1113                 processpap(sid, t, pppdata, lppp);
1114         }
1115         else if (proto == PPPCHAP)
1116         {
1117                 session[sid].last_packet = time_now;
1118                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1119                 processchap(sid, t, pppdata, lppp);
1120         }
1121         else if (proto == PPPLCP)
1122         {
1123                 session[sid].last_packet = time_now;
1124                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1125                 processlcp(sid, t, pppdata, lppp);
1126         }
1127         else if (proto == PPPIPCP)
1128         {
1129                 session[sid].last_packet = time_now;
1130                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1131                 processipcp(sid, t, pppdata, lppp);
1132         }
1133         else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
1134         {
1135                 session[sid].last_packet = time_now;
1136                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1137                 processipv6cp(sid, t, pppdata, lppp);
1138         }
1139         else if (proto == PPPCCP)
1140         {
1141                 session[sid].last_packet = time_now;
1142                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1143                 processccp(sid, t, pppdata, lppp);
1144         }
1145         else if (proto == PPPIP)
1146         {
1147                 session[sid].last_packet = session[sid].last_data = time_now;
1148                 if (session[sid].walled_garden && !config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1149                 processipin(sid, t, pppdata, lppp);
1150         }
1151         else if (proto == PPPMP)
1152         {
1153                 session[sid].last_packet = session[sid].last_data = time_now;
1154                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1155                 processmpin(sid, t, pppdata, lppp);
1156         }
1157         else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
1158         {
1159                 session[sid].last_packet = session[sid].last_data = time_now;
1160                 if (session[sid].walled_garden && !config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1161                 processipv6in(sid, t, pppdata, lppp);
1162         }
1163         else if (session[sid].ppp.lcp == Opened)
1164         {
1165                 session[sid].last_packet = time_now;
1166                 if (!config->cluster_iam_master) { master_forward_pppoe_packet(pack, size, hdr->code); return; }
1167                 protoreject(sid, t, pppdata, lppp, proto);
1168         }
1169         else
1170         {
1171                 LOG(3, sid, t, "process_pppoe_sess: Unknown PPP protocol 0x%04X received in LCP %s state\n",
1172                         proto, ppp_state(session[sid].ppp.lcp));
1173         }
1174 }
1175
1176 void pppoe_send_garp()
1177 {
1178         int s;
1179         struct ifreq ifr;
1180         uint8_t mac[6];
1181
1182         if (!*config->pppoe_if_to_bind)
1183                 return;
1184
1185         s = socket(PF_INET, SOCK_DGRAM, 0);
1186         if (s < 0)
1187         {
1188                 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
1189                 return;
1190         }
1191         memset(&ifr, 0, sizeof(ifr));
1192         strncpy(ifr.ifr_name, config->pppoe_if_to_bind, sizeof(ifr.ifr_name) - 1);
1193         if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
1194         {
1195                 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
1196                 close(s);
1197                 return;
1198         }
1199         memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
1200         if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
1201         {
1202                 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
1203                 close(s);
1204                 return;
1205         }
1206         close(s);
1207
1208         sendarp(ifr.ifr_ifindex, mac, config->iftun_address);
1209 }
1210
1211 // rcv pppoe data from slave
1212 void pppoe_process_forward(uint8_t *pack, int size, in_addr_t addr)
1213 {
1214         struct ethhdr *ethhdr = (struct ethhdr *)pack;
1215
1216         if (ethhdr->h_proto == htons(ETH_P_PPP_DISC))
1217                 process_pppoe_disc(pack, size);
1218         else if (ethhdr->h_proto == htons(ETH_P_PPP_SES))
1219                 process_pppoe_sess(pack, size);
1220         else
1221                 LOG(0, 0, 0, "pppoe_process_forward: I got a C_PPPOE_FORWARD from %s, but not a PPPOE data?\n", fmtaddr(addr, 0));
1222 }