nhrpd/nhrp_peer.c

   1 /* NHRP peer functions
   2  * Copyright (c) 2014-2015 Timo Teräs
   3  *
   4  * This file is free software: you may copy, redistribute and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <netinet/if_ether.h>
  11
  12 #include "zebra.h"
  13 #include "memory.h"
  14 #include "thread.h"
  15 #include "hash.h"
  16
  17 #include "nhrpd.h"
  18 #include "nhrp_protocol.h"
  19 #include "os.h"
  20
  21 DEFINE_MTYPE_STATIC(NHRPD, NHRP_PEER, "NHRP peer entry")
  22
  23 struct ipv6hdr {
  24         uint8_t priority_version;
  25         uint8_t flow_lbl[3];
  26         uint16_t payload_len;
  27         uint8_t nexthdr;
  28         uint8_t hop_limit;
  29         struct in6_addr saddr;
  30         struct in6_addr daddr;
  31 };
  32
  33 static void nhrp_packet_debug(struct zbuf *zb, const char *dir);
  34
  35 static void nhrp_peer_check_delete(struct nhrp_peer *p)
  36 {
  37         struct nhrp_interface *nifp = p->ifp->info;
  38
  39         if (p->ref || notifier_active(&p->notifier_list))
  40                 return;
  41
  42         THREAD_OFF(p->t_fallback);
  43         hash_release(nifp->peer_hash, p);
  44         nhrp_interface_notify_del(p->ifp, &p->ifp_notifier);
  45         nhrp_vc_notify_del(p->vc, &p->vc_notifier);
  46         XFREE(MTYPE_NHRP_PEER, p);
  47 }
  48
  49 static int nhrp_peer_notify_up(struct thread *t)
  50 {
  51         struct nhrp_peer *p = THREAD_ARG(t);
  52         struct nhrp_vc *vc = p->vc;
  53         struct interface *ifp = p->ifp;
  54         struct nhrp_interface *nifp = ifp->info;
  55
  56         p->t_fallback = NULL;
  57         if (nifp->enabled && (!nifp->ipsec_profile || vc->ipsec)) {
  58                 p->online = 1;
  59                 nhrp_peer_ref(p);
  60                 notifier_call(&p->notifier_list, NOTIFY_PEER_UP);
  61                 nhrp_peer_unref(p);
  62         }
  63
  64         return 0;
  65 }
  66
  67 static void __nhrp_peer_check(struct nhrp_peer *p)
  68 {
  69         struct nhrp_vc *vc = p->vc;
  70         struct interface *ifp = p->ifp;
  71         struct nhrp_interface *nifp = ifp->info;
  72         unsigned online;
  73
  74         online = nifp->enabled && (!nifp->ipsec_profile || vc->ipsec);
  75         if (p->online != online) {
  76                 THREAD_OFF(p->t_fallback);
  77                 if (online && notifier_active(&p->notifier_list)) {
  78                         /* If we requested the IPsec connection, delay
  79                          * the up notification a bit to allow things
  80                          * settle down. This allows IKE to install
  81                          * SPDs and SAs. */
  82                         thread_add_timer_msec(master, nhrp_peer_notify_up, p,
  83                                               50, &p->t_fallback);
  84                 } else {
  85                         nhrp_peer_ref(p);
  86                         p->online = online;
  87                         if (online) {
  88                                 notifier_call(&p->notifier_list, NOTIFY_PEER_UP);
  89                         } else {
  90                                 p->requested = p->fallback_requested = 0;
  91                                 notifier_call(&p->notifier_list, NOTIFY_PEER_DOWN);
  92                         }
  93                         nhrp_peer_unref(p);
  94                 }
  95         }
  96 }
  97
  98 static void nhrp_peer_vc_notify(struct notifier_block *n, unsigned long cmd)
  99 {
 100         struct nhrp_peer *p = container_of(n, struct nhrp_peer, vc_notifier);
 101
 102         switch (cmd) {
 103         case NOTIFY_VC_IPSEC_CHANGED:
 104                 __nhrp_peer_check(p);
 105                 break;
 106         case NOTIFY_VC_IPSEC_UPDATE_NBMA:
 107                 nhrp_peer_ref(p);
 108                 notifier_call(&p->notifier_list, NOTIFY_PEER_NBMA_CHANGING);
 109                 nhrp_peer_unref(p);
 110                 break;
 111         }
 112 }
 113
 114 static void nhrp_peer_ifp_notify(struct notifier_block *n, unsigned long cmd)
 115 {
 116         struct nhrp_peer *p = container_of(n, struct nhrp_peer, ifp_notifier);
 117         struct nhrp_interface *nifp;
 118         struct nhrp_vc *vc;
 119
 120         nhrp_peer_ref(p);
 121         switch (cmd) {
 122         case NOTIFY_INTERFACE_UP:
 123         case NOTIFY_INTERFACE_DOWN:
 124                 __nhrp_peer_check(p);
 125                 break;
 126         case NOTIFY_INTERFACE_NBMA_CHANGED:
 127                 /* Source NBMA changed, rebind to new VC */
 128                 nifp = p->ifp->info;
 129                 vc = nhrp_vc_get(&nifp->nbma, &p->vc->remote.nbma, 1);
 130                 if (vc && p->vc != vc) {
 131                         nhrp_vc_notify_del(p->vc, &p->vc_notifier);
 132                         p->vc = vc;
 133                         nhrp_vc_notify_add(p->vc, &p->vc_notifier, nhrp_peer_vc_notify);
 134                         __nhrp_peer_check(p);
 135                 }
 136                 /* Fall-through to post config update */
 137         case NOTIFY_INTERFACE_ADDRESS_CHANGED:
 138                 notifier_call(&p->notifier_list, NOTIFY_PEER_IFCONFIG_CHANGED);
 139                 break;
 140         case NOTIFY_INTERFACE_MTU_CHANGED:
 141                 notifier_call(&p->notifier_list, NOTIFY_PEER_MTU_CHANGED);
 142                 break;
 143         }
 144         nhrp_peer_unref(p);
 145 }
 146
 147 static unsigned int nhrp_peer_key(void *peer_data)
 148 {
 149         struct nhrp_peer *p = peer_data;
 150         return sockunion_hash(&p->vc->remote.nbma);
 151 }
 152
 153 static int nhrp_peer_cmp(const void *cache_data, const void *key_data)
 154 {
 155         const struct nhrp_peer *a = cache_data;
 156         const struct nhrp_peer *b = key_data;
 157         return a->ifp == b->ifp && a->vc == b->vc;
 158 }
 159
 160 static void *nhrp_peer_create(void *data)
 161 {
 162         struct nhrp_peer *p, *key = data;
 163
 164         p = XMALLOC(MTYPE_NHRP_PEER, sizeof(*p));
 165         if (p) {
 166                 *p = (struct nhrp_peer) {
 167                         .ref = 0,
 168                         .ifp = key->ifp,
 169                         .vc = key->vc,
 170                         .notifier_list = NOTIFIER_LIST_INITIALIZER(&p->notifier_list),
 171                 };
 172                 nhrp_vc_notify_add(p->vc, &p->vc_notifier, nhrp_peer_vc_notify);
 173                 nhrp_interface_notify_add(p->ifp, &p->ifp_notifier, nhrp_peer_ifp_notify);
 174         }
 175         return p;
 176 }
 177
 178 struct nhrp_peer *nhrp_peer_get(struct interface *ifp, const union sockunion *remote_nbma)
 179 {
 180         struct nhrp_interface *nifp = ifp->info;
 181         struct nhrp_peer key, *p;
 182         struct nhrp_vc *vc;
 183
 184         if (!nifp->peer_hash) {
 185                 nifp->peer_hash = hash_create(nhrp_peer_key, nhrp_peer_cmp);
 186                 if (!nifp->peer_hash) return NULL;
 187         }
 188
 189         vc = nhrp_vc_get(&nifp->nbma, remote_nbma, 1);
 190         if (!vc) return NULL;
 191
 192         key.ifp = ifp;
 193         key.vc = vc;
 194
 195         p = hash_get(nifp->peer_hash, &key, nhrp_peer_create);
 196         nhrp_peer_ref(p);
 197         if (p->ref == 1) __nhrp_peer_check(p);
 198
 199         return p;
 200 }
 201
 202 struct nhrp_peer *nhrp_peer_ref(struct nhrp_peer *p)
 203 {
 204         if (p) p->ref++;
 205         return p;
 206 }
 207
 208 void nhrp_peer_unref(struct nhrp_peer *p)
 209 {
 210         if (p) {
 211                 p->ref--;
 212                 nhrp_peer_check_delete(p);
 213         }
 214 }
 215
 216 static int nhrp_peer_request_timeout(struct thread *t)
 217 {
 218         struct nhrp_peer *p = THREAD_ARG(t);
 219         struct nhrp_vc *vc = p->vc;
 220         struct interface *ifp = p->ifp;
 221         struct nhrp_interface *nifp = ifp->info;
 222
 223         p->t_fallback = NULL;
 224
 225         if (p->online)
 226                 return 0;
 227
 228         if (nifp->ipsec_fallback_profile && !p->prio && !p->fallback_requested) {
 229                 p->fallback_requested = 1;
 230                 vici_request_vc(nifp->ipsec_fallback_profile,
 231                                 &vc->local.nbma, &vc->remote.nbma, p->prio);
 232                 thread_add_timer(master, nhrp_peer_request_timeout, p, 30,
 233                                  &p->t_fallback);
 234         } else {
 235                 p->requested = p->fallback_requested = 0;
 236         }
 237
 238         return 0;
 239 }
 240
 241 int nhrp_peer_check(struct nhrp_peer *p, int establish)
 242 {
 243         struct nhrp_vc *vc = p->vc;
 244         struct interface *ifp = p->ifp;
 245         struct nhrp_interface *nifp = ifp->info;
 246
 247         if (p->online)
 248                 return 1;
 249         if (!establish)
 250                 return 0;
 251         if (p->requested)
 252                 return 0;
 253         if (!nifp->ipsec_profile)
 254                 return 0;
 255         if (sockunion_family(&vc->local.nbma) == AF_UNSPEC)
 256                 return 0;
 257
 258         p->prio = establish > 1;
 259         p->requested = 1;
 260         vici_request_vc(nifp->ipsec_profile, &vc->local.nbma, &vc->remote.nbma, p->prio);
 261         thread_add_timer(master, nhrp_peer_request_timeout, p,
 262                          (nifp->ipsec_fallback_profile && !p->prio) ? 15 : 30,
 263                          &p->t_fallback);
 264
 265         return 0;
 266 }
 267
 268 void nhrp_peer_notify_add(struct nhrp_peer *p, struct notifier_block *n, notifier_fn_t fn)
 269 {
 270         notifier_add(n, &p->notifier_list, fn);
 271 }
 272
 273 void nhrp_peer_notify_del(struct nhrp_peer *p, struct notifier_block *n)
 274 {
 275         notifier_del(n);
 276         nhrp_peer_check_delete(p);
 277 }
 278
 279 void nhrp_peer_send(struct nhrp_peer *p, struct zbuf *zb)
 280 {
 281         char buf[2][256];
 282
 283         nhrp_packet_debug(zb, "Send");
 284
 285         if (!p->online)
 286                 return;
 287
 288         debugf(NHRP_DEBUG_KERNEL, "PACKET: Send %s -> %s",
 289                 sockunion2str(&p->vc->local.nbma, buf[0], sizeof buf[0]),
 290                 sockunion2str(&p->vc->remote.nbma, buf[1], sizeof buf[1]));
 291
 292         os_sendmsg(zb->head, zbuf_used(zb),
 293                 p->ifp->ifindex,
 294                 sockunion_get_addr(&p->vc->remote.nbma),
 295                 sockunion_get_addrlen(&p->vc->remote.nbma));
 296         zbuf_reset(zb);
 297 }
 298
 299 static void nhrp_handle_resolution_req(struct nhrp_packet_parser *p)
 300 {
 301         struct zbuf *zb, payload;
 302         struct nhrp_packet_header *hdr;
 303         struct nhrp_cie_header *cie;
 304         struct nhrp_extension_header *ext;
 305         struct nhrp_interface *nifp;
 306         struct nhrp_peer *peer;
 307
 308         if (!(p->if_ad->flags & NHRP_IFF_SHORTCUT)) {
 309                 debugf(NHRP_DEBUG_COMMON, "Shortcuts disabled");
 310                 /* FIXME: Send error indication? */
 311                 return;
 312         }
 313
 314         if (p->if_ad->network_id &&
 315             p->route_type == NHRP_ROUTE_OFF_NBMA &&
 316             p->route_prefix.prefixlen < 8) {
 317                 debugf(NHRP_DEBUG_COMMON, "Shortcut to more generic than /8 dropped");
 318                 return;
 319         }
 320
 321         debugf(NHRP_DEBUG_COMMON, "Parsing and replying to Resolution Req");
 322
 323         if (nhrp_route_address(p->ifp, &p->src_proto, NULL, &peer) != NHRP_ROUTE_NBMA_NEXTHOP)
 324                 return;
 325
 326 #if 0
 327         /* FIXME: Update requestors binding if CIE specifies holding time */
 328         nhrp_cache_update_binding(
 329                         NHRP_CACHE_CACHED, &p->src_proto,
 330                         nhrp_peer_get(p->ifp, &p->src_nbma),
 331                         htons(cie->holding_time));
 332 #endif
 333
 334         nifp = peer->ifp->info;
 335
 336         /* Create reply */
 337         zb = zbuf_alloc(1500);
 338         hdr = nhrp_packet_push(zb, NHRP_PACKET_RESOLUTION_REPLY, &p->src_nbma, &p->src_proto, &p->dst_proto);
 339
 340         /* Copied information from request */
 341         hdr->flags = p->hdr->flags & htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER|NHRP_FLAG_RESOLUTION_SOURCE_STABLE);
 342         hdr->flags |= htons(NHRP_FLAG_RESOLUTION_DESTINATION_STABLE | NHRP_FLAG_RESOLUTION_AUTHORATIVE);
 343         hdr->u.request_id = p->hdr->u.request_id;
 344
 345         /* CIE payload */
 346         cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nbma, &p->if_ad->addr);
 347         cie->holding_time = htons(p->if_ad->holdtime);
 348         cie->mtu = htons(p->if_ad->mtu);
 349         if (p->if_ad->network_id && p->route_type == NHRP_ROUTE_OFF_NBMA)
 350                 cie->prefix_length = p->route_prefix.prefixlen;
 351         else
 352                 cie->prefix_length = 8 * sockunion_get_addrlen(&p->if_ad->addr);
 353
 354         /* Handle extensions */
 355         while ((ext = nhrp_ext_pull(&p->extensions, &payload)) != NULL) {
 356                 switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
 357                 case NHRP_EXTENSION_NAT_ADDRESS:
 358                         if (sockunion_family(&nifp->nat_nbma) == AF_UNSPEC)
 359                                 break;
 360                         ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
 361                         if (!ext) goto err;
 362                         cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nat_nbma, &p->if_ad->addr);
 363                         if (!cie) goto err;
 364                         nhrp_ext_complete(zb, ext);
 365                         break;
 366                 default:
 367                         if (nhrp_ext_reply(zb, hdr, p->ifp, ext, &payload) < 0)
 368                                 goto err;
 369                         break;
 370                 }
 371         }
 372
 373         nhrp_packet_complete(zb, hdr);
 374         nhrp_peer_send(peer, zb);
 375 err:
 376         nhrp_peer_unref(peer);
 377         zbuf_free(zb);
 378 }
 379
 380 static void nhrp_handle_registration_request(struct nhrp_packet_parser *p)
 381 {
 382         struct interface *ifp = p->ifp;
 383         struct zbuf *zb, payload;
 384         struct nhrp_packet_header *hdr;
 385         struct nhrp_cie_header *cie;
 386         struct nhrp_extension_header *ext;
 387         struct nhrp_cache *c;
 388         union sockunion cie_nbma, cie_proto, *proto_addr, *nbma_addr, *nbma_natoa;
 389         int holdtime, prefix_len, hostprefix_len, natted = 0;
 390         size_t paylen;
 391         void *pay;
 392
 393         debugf(NHRP_DEBUG_COMMON, "Parsing and replying to Registration Req");
 394         hostprefix_len = 8 * sockunion_get_addrlen(&p->if_ad->addr);
 395
 396         if (!sockunion_same(&p->src_nbma, &p->peer->vc->remote.nbma))
 397                 natted = 1;
 398
 399         /* Create reply */
 400         zb = zbuf_alloc(1500);
 401         hdr = nhrp_packet_push(zb, NHRP_PACKET_REGISTRATION_REPLY,
 402                 &p->src_nbma, &p->src_proto, &p->if_ad->addr);
 403
 404         /* Copied information from request */
 405         hdr->flags = p->hdr->flags & htons(NHRP_FLAG_REGISTRATION_UNIQUE | NHRP_FLAG_REGISTRATION_NAT);
 406         hdr->u.request_id = p->hdr->u.request_id;
 407
 408         /* Copy payload CIEs */
 409         paylen = zbuf_used(&p->payload);
 410         pay = zbuf_pushn(zb, paylen);
 411         if (!pay) goto err;
 412         memcpy(pay, zbuf_pulln(&p->payload, paylen), paylen);
 413         zbuf_init(&payload, pay, paylen, paylen);
 414
 415         while ((cie = nhrp_cie_pull(&payload, hdr, &cie_nbma, &cie_proto)) != NULL) {
 416                 prefix_len = cie->prefix_length;
 417                 if (prefix_len == 0 || prefix_len >= hostprefix_len)
 418                         prefix_len = hostprefix_len;
 419
 420                 if (prefix_len != hostprefix_len && !(p->hdr->flags & htons(NHRP_FLAG_REGISTRATION_UNIQUE))) {
 421                         cie->code = NHRP_CODE_BINDING_NON_UNIQUE;
 422                         continue;
 423                 }
 424
 425                 /* We currently support only unique prefix registrations */
 426                 if (prefix_len != hostprefix_len) {
 427                         cie->code = NHRP_CODE_ADMINISTRATIVELY_PROHIBITED;
 428                         continue;
 429                 }
 430
 431                 proto_addr = (sockunion_family(&cie_proto) == AF_UNSPEC) ? &p->src_proto : &cie_proto;
 432                 nbma_addr = (sockunion_family(&cie_nbma) == AF_UNSPEC) ? &p->src_nbma : &cie_nbma;
 433                 nbma_natoa = NULL;
 434                 if (natted) {
 435                         nbma_natoa = nbma_addr;
 436                 }
 437
 438                 holdtime = htons(cie->holding_time);
 439                 if (!holdtime) holdtime = p->if_ad->holdtime;
 440
 441                 c = nhrp_cache_get(ifp, proto_addr, 1);
 442                 if (!c) {
 443                         cie->code = NHRP_CODE_INSUFFICIENT_RESOURCES;
 444                         continue;
 445                 }
 446
 447                 if (!nhrp_cache_update_binding(c, NHRP_CACHE_DYNAMIC, holdtime, nhrp_peer_ref(p->peer), htons(cie->mtu), nbma_natoa)) {
 448                         cie->code = NHRP_CODE_ADMINISTRATIVELY_PROHIBITED;
 449                         continue;
 450                 }
 451
 452                 cie->code = NHRP_CODE_SUCCESS;
 453         }
 454
 455         /* Handle extensions */
 456         while ((ext = nhrp_ext_pull(&p->extensions, &payload)) != NULL) {
 457                 switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
 458                 case NHRP_EXTENSION_NAT_ADDRESS:
 459                         ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
 460                         if (!ext) goto err;
 461                         zbuf_copy(zb, &payload, zbuf_used(&payload));
 462                         if (natted) {
 463                                 nhrp_cie_push(zb, NHRP_CODE_SUCCESS,
 464                                         &p->peer->vc->remote.nbma,
 465                                         &p->src_proto);
 466                         }
 467                         nhrp_ext_complete(zb, ext);
 468                         break;
 469                 default:
 470                         if (nhrp_ext_reply(zb, hdr, ifp, ext, &payload) < 0)
 471                                 goto err;
 472                         break;
 473                 }
 474         }
 475
 476         nhrp_packet_complete(zb, hdr);
 477         nhrp_peer_send(p->peer, zb);
 478 err:
 479         zbuf_free(zb);
 480 }
 481
 482 static int parse_ether_packet(struct zbuf *zb, uint16_t protocol_type, union sockunion *src, union sockunion *dst)
 483 {
 484         switch (protocol_type) {
 485         case ETH_P_IP: {
 486                         struct iphdr *iph = zbuf_pull(zb, struct iphdr);
 487                         if (iph) {
 488                                 if (src) sockunion_set(src, AF_INET, (uint8_t*) &iph->saddr, sizeof(iph->saddr));
 489                                 if (dst) sockunion_set(dst, AF_INET, (uint8_t*) &iph->daddr, sizeof(iph->daddr));
 490                         }
 491                 }
 492                 break;
 493         case ETH_P_IPV6: {
 494                         struct ipv6hdr *iph = zbuf_pull(zb, struct ipv6hdr);
 495                         if (iph) {
 496                                 if (src) sockunion_set(src, AF_INET6, (uint8_t*) &iph->saddr, sizeof(iph->saddr));
 497                                 if (dst) sockunion_set(dst, AF_INET6, (uint8_t*) &iph->daddr, sizeof(iph->daddr));
 498                         }
 499                 }
 500                 break;
 501         default:
 502                 return 0;
 503         }
 504         return 1;
 505 }
 506
 507 void nhrp_peer_send_indication(struct interface *ifp, uint16_t protocol_type, struct zbuf *pkt)
 508 {
 509         union sockunion dst;
 510         struct zbuf *zb, payload;
 511         struct nhrp_interface *nifp = ifp->info;
 512         struct nhrp_afi_data *if_ad;
 513         struct nhrp_packet_header *hdr;
 514         struct nhrp_peer *p;
 515         char buf[2][SU_ADDRSTRLEN];
 516
 517         if (!nifp->enabled) return;
 518
 519         payload = *pkt;
 520         if (!parse_ether_packet(&payload, protocol_type, &dst, NULL))
 521                 return;
 522
 523         if (nhrp_route_address(ifp, &dst, NULL, &p) != NHRP_ROUTE_NBMA_NEXTHOP)
 524                 return;
 525
 526         if_ad = &nifp->afi[family2afi(sockunion_family(&dst))];
 527         if (!(if_ad->flags & NHRP_IFF_REDIRECT)) {
 528                 debugf(NHRP_DEBUG_COMMON, "Send Traffic Indication to %s about packet to %s ignored",
 529                         sockunion2str(&p->vc->remote.nbma, buf[0], sizeof buf[0]),
 530                         sockunion2str(&dst, buf[1], sizeof buf[1]));
 531                 return;
 532         }
 533
 534         debugf(NHRP_DEBUG_COMMON, "Send Traffic Indication to %s (online=%d) about packet to %s",
 535                 sockunion2str(&p->vc->remote.nbma, buf[0], sizeof buf[0]),
 536                 p->online,
 537                 sockunion2str(&dst, buf[1], sizeof buf[1]));
 538
 539         /* Create reply */
 540         zb = zbuf_alloc(1500);
 541         hdr = nhrp_packet_push(zb, NHRP_PACKET_TRAFFIC_INDICATION, &nifp->nbma, &if_ad->addr, &dst);
 542         hdr->hop_count = 0;
 543
 544         /* Payload is the packet causing indication */
 545         zbuf_copy(zb, pkt, zbuf_used(pkt));
 546         nhrp_packet_complete(zb, hdr);
 547         nhrp_peer_send(p, zb);
 548         nhrp_peer_unref(p);
 549         zbuf_free(zb);
 550 }
 551
 552 static void nhrp_handle_error_ind(struct nhrp_packet_parser *pp)
 553 {
 554         struct zbuf origmsg = pp->payload;
 555         struct nhrp_packet_header *hdr;
 556         struct nhrp_reqid *reqid;
 557         union sockunion src_nbma, src_proto, dst_proto;
 558         char buf[2][SU_ADDRSTRLEN];
 559
 560         hdr = nhrp_packet_pull(&origmsg, &src_nbma, &src_proto, &dst_proto);
 561         if (!hdr) return;
 562
 563         debugf(NHRP_DEBUG_COMMON, "Error Indication from %s about packet to %s ignored",
 564                 sockunion2str(&pp->src_proto, buf[0], sizeof buf[0]),
 565                 sockunion2str(&dst_proto, buf[1], sizeof buf[1]));
 566
 567         reqid = nhrp_reqid_lookup(&nhrp_packet_reqid, htonl(hdr->u.request_id));
 568         if (reqid)
 569                 reqid->cb(reqid, pp);
 570 }
 571
 572 static void nhrp_handle_traffic_ind(struct nhrp_packet_parser *p)
 573 {
 574         union sockunion dst;
 575         char buf[2][SU_ADDRSTRLEN];
 576
 577         if (!parse_ether_packet(&p->payload, htons(p->hdr->protocol_type), NULL, &dst))
 578                 return;
 579
 580         debugf(NHRP_DEBUG_COMMON, "Traffic Indication from %s about packet to %s: %s",
 581                 sockunion2str(&p->src_proto, buf[0], sizeof buf[0]),
 582                 sockunion2str(&dst, buf[1], sizeof buf[1]),
 583                 (p->if_ad->flags & NHRP_IFF_SHORTCUT) ? "trying shortcut" : "ignored");
 584
 585         if (p->if_ad->flags & NHRP_IFF_SHORTCUT)
 586                 nhrp_shortcut_initiate(&dst);
 587 }
 588
 589 enum packet_type_t {
 590         PACKET_UNKNOWN = 0,
 591         PACKET_REQUEST,
 592         PACKET_REPLY,
 593         PACKET_INDICATION,
 594 };
 595
 596 static struct {
 597         enum packet_type_t type;
 598         const char *name;
 599         void (*handler)(struct nhrp_packet_parser *);
 600 } packet_types[] = {
 601         [NHRP_PACKET_RESOLUTION_REQUEST] = {
 602                 .type = PACKET_REQUEST,
 603                 .name = "Resolution-Request",
 604                 .handler = nhrp_handle_resolution_req,
 605         },
 606         [NHRP_PACKET_RESOLUTION_REPLY] = {
 607                 .type = PACKET_REPLY,
 608                 .name = "Resolution-Reply",
 609         },
 610         [NHRP_PACKET_REGISTRATION_REQUEST] = {
 611                 .type = PACKET_REQUEST,
 612                 .name = "Registration-Request",
 613                 .handler = nhrp_handle_registration_request,
 614         },
 615         [NHRP_PACKET_REGISTRATION_REPLY] = {
 616                 .type = PACKET_REPLY,
 617                 .name = "Registration-Reply",
 618         },
 619         [NHRP_PACKET_PURGE_REQUEST] = {
 620                 .type = PACKET_REQUEST,
 621                 .name = "Purge-Request",
 622         },
 623         [NHRP_PACKET_PURGE_REPLY] = {
 624                 .type = PACKET_REPLY,
 625                 .name = "Purge-Reply",
 626         },
 627         [NHRP_PACKET_ERROR_INDICATION] = {
 628                 .type = PACKET_INDICATION,
 629                 .name = "Error-Indication",
 630                 .handler = nhrp_handle_error_ind,
 631         },
 632         [NHRP_PACKET_TRAFFIC_INDICATION] = {
 633                 .type = PACKET_INDICATION,
 634                 .name = "Traffic-Indication",
 635                 .handler = nhrp_handle_traffic_ind,
 636         }
 637 };
 638
 639 static void nhrp_peer_forward(struct nhrp_peer *p, struct nhrp_packet_parser *pp)
 640 {
 641         struct zbuf *zb, extpl;
 642         struct nhrp_packet_header *hdr;
 643         struct nhrp_extension_header *ext, *dst;
 644         struct nhrp_cie_header *cie;
 645         struct nhrp_interface *nifp = pp->ifp->info;
 646         struct nhrp_afi_data *if_ad = pp->if_ad;
 647         union sockunion cie_nbma, cie_protocol;
 648         uint16_t type, len;
 649
 650         if (pp->hdr->hop_count == 0)
 651                 return;
 652
 653         /* Create forward packet - copy header */
 654         zb = zbuf_alloc(1500);
 655         hdr = nhrp_packet_push(zb, pp->hdr->type, &pp->src_nbma, &pp->src_proto, &pp->dst_proto);
 656         hdr->flags = pp->hdr->flags;
 657         hdr->hop_count = pp->hdr->hop_count - 1;
 658         hdr->u.request_id = pp->hdr->u.request_id;
 659
 660         /* Copy payload */
 661         zbuf_copy(zb, &pp->payload, zbuf_used(&pp->payload));
 662
 663         /* Copy extensions */
 664         while ((ext = nhrp_ext_pull(&pp->extensions, &extpl)) != NULL) {
 665                 type = htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY;
 666                 len = htons(ext->length);
 667
 668                 if (type == NHRP_EXTENSION_END)
 669                         break;
 670
 671                 dst = nhrp_ext_push(zb, hdr, htons(ext->type));
 672                 if (!dst) goto err;
 673
 674                 switch (type) {
 675                 case NHRP_EXTENSION_FORWARD_TRANSIT_NHS:
 676                 case NHRP_EXTENSION_REVERSE_TRANSIT_NHS:
 677                         zbuf_put(zb, extpl.head, len);
 678                         if ((type == NHRP_EXTENSION_REVERSE_TRANSIT_NHS) ==
 679                             (packet_types[hdr->type].type == PACKET_REPLY)) {
 680                                 /* Check NHS list for forwarding loop */
 681                                 while ((cie = nhrp_cie_pull(&extpl, pp->hdr, &cie_nbma, &cie_protocol)) != NULL) {
 682                                         if (sockunion_same(&p->vc->remote.nbma, &cie_nbma))
 683                                                 goto err;
 684                                 }
 685                                 /* Append our selves to the list */
 686                                 cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nbma, &if_ad->addr);
 687                                 if (!cie) goto err;
 688                                 cie->holding_time = htons(if_ad->holdtime);
 689                         }
 690                         break;
 691                 default:
 692                         if (htons(ext->type) & NHRP_EXTENSION_FLAG_COMPULSORY)
 693                                 /* FIXME: RFC says to just copy, but not
 694                                  * append our selves to the transit NHS list */
 695                                 goto err;
 696                 case NHRP_EXTENSION_RESPONDER_ADDRESS:
 697                         /* Supported compulsory extensions, and any
 698                          * non-compulsory that is not explicitly handled,
 699                          * should be just copied. */
 700                         zbuf_copy(zb, &extpl, len);
 701                         break;
 702                 }
 703                 nhrp_ext_complete(zb, dst);
 704         }
 705
 706         nhrp_packet_complete(zb, hdr);
 707         nhrp_peer_send(p, zb);
 708         zbuf_free(zb);
 709         return;
 710 err:
 711         nhrp_packet_debug(pp->pkt, "FWD-FAIL");
 712         zbuf_free(zb);
 713 }
 714
 715 static void nhrp_packet_debug(struct zbuf *zb, const char *dir)
 716 {
 717         char buf[2][SU_ADDRSTRLEN];
 718         union sockunion src_nbma, src_proto, dst_proto;
 719         struct nhrp_packet_header *hdr;
 720         struct zbuf zhdr;
 721         int reply;
 722
 723         if (likely(!(debug_flags & NHRP_DEBUG_COMMON)))
 724                 return;
 725
 726         zbuf_init(&zhdr, zb->buf, zb->tail-zb->buf, zb->tail-zb->buf);
 727         hdr = nhrp_packet_pull(&zhdr, &src_nbma, &src_proto, &dst_proto);
 728
 729         sockunion2str(&src_proto, buf[0], sizeof buf[0]);
 730         sockunion2str(&dst_proto, buf[1], sizeof buf[1]);
 731
 732         reply = packet_types[hdr->type].type == PACKET_REPLY;
 733         debugf(NHRP_DEBUG_COMMON, "%s %s(%d) %s -> %s",
 734                 dir,
 735                 packet_types[hdr->type].name ? : "Unknown",
 736                 hdr->type,
 737                 reply ? buf[1] : buf[0],
 738                 reply ? buf[0] : buf[1]);
 739 }
 740
 741 static int proto2afi(uint16_t proto)
 742 {
 743         switch (proto) {
 744         case ETH_P_IP: return AFI_IP;
 745         case ETH_P_IPV6: return AFI_IP6;
 746         }
 747         return AF_UNSPEC;
 748 }
 749
 750 struct nhrp_route_info {
 751         int local;
 752         struct interface *ifp;
 753         struct nhrp_vc *vc;
 754 };
 755
 756 void nhrp_peer_recv(struct nhrp_peer *p, struct zbuf *zb)
 757 {
 758         char buf[2][SU_ADDRSTRLEN];
 759         struct nhrp_packet_header *hdr;
 760         struct nhrp_vc *vc = p->vc;
 761         struct interface *ifp = p->ifp;
 762         struct nhrp_interface *nifp = ifp->info;
 763         struct nhrp_packet_parser pp;
 764         struct nhrp_peer *peer = NULL;
 765         struct nhrp_reqid *reqid;
 766         const char *info = NULL;
 767         union sockunion *target_addr;
 768         unsigned paylen, extoff, extlen, realsize;
 769         afi_t nbma_afi, proto_afi;
 770
 771         debugf(NHRP_DEBUG_KERNEL, "PACKET: Recv %s -> %s",
 772                 sockunion2str(&vc->remote.nbma, buf[0], sizeof buf[0]),
 773                 sockunion2str(&vc->local.nbma, buf[1], sizeof buf[1]));
 774
 775         if (!p->online) {
 776                 info = "peer not online";
 777                 goto drop;
 778         }
 779
 780         if (nhrp_packet_calculate_checksum(zb->head, zbuf_used(zb)) != 0) {
 781                 info = "bad checksum";
 782                 goto drop;
 783         }
 784
 785         realsize = zbuf_used(zb);
 786         hdr = nhrp_packet_pull(zb, &pp.src_nbma, &pp.src_proto, &pp.dst_proto);
 787         if (!hdr) {
 788                 info = "corrupt header";
 789                 goto drop;
 790         }
 791
 792         pp.ifp = ifp;
 793         pp.pkt = zb;
 794         pp.hdr = hdr;
 795         pp.peer = p;
 796
 797         nbma_afi = htons(hdr->afnum);
 798         proto_afi = proto2afi(htons(hdr->protocol_type));
 799         if (hdr->type > ZEBRA_NUM_OF(packet_types) ||
 800             hdr->version != NHRP_VERSION_RFC2332 ||
 801             nbma_afi >= AFI_MAX || proto_afi == AF_UNSPEC ||
 802             packet_types[hdr->type].type == PACKET_UNKNOWN ||
 803             htons(hdr->packet_size) > realsize) {
 804                 zlog_info("From %s: error: packet type %d, version %d, AFI %d, proto %x, size %d (real size %d)",
 805                            sockunion2str(&vc->remote.nbma, buf[0], sizeof buf[0]),
 806                            (int) hdr->type, (int) hdr->version,
 807                            (int) nbma_afi, (int) htons(hdr->protocol_type),
 808                            (int) htons(hdr->packet_size), (int) realsize);
 809                 goto drop;
 810         }
 811         pp.if_ad = &((struct nhrp_interface *)ifp->info)->afi[proto_afi];
 812
 813         extoff = htons(hdr->extension_offset);
 814         if (extoff) {
 815                 if (extoff >= realsize) {
 816                         info = "extoff larger than packet";
 817                         goto drop;
 818                 }
 819                 paylen = extoff - (zb->head - zb->buf);
 820         } else {
 821                 paylen = zbuf_used(zb);
 822         }
 823         zbuf_init(&pp.payload, zbuf_pulln(zb, paylen), paylen, paylen);
 824         extlen = zbuf_used(zb);
 825         zbuf_init(&pp.extensions, zbuf_pulln(zb, extlen), extlen, extlen);
 826
 827         if (!nifp->afi[proto_afi].network_id) {
 828                 info = "nhrp not enabled";
 829                 goto drop;
 830         }
 831
 832         nhrp_packet_debug(zb, "Recv");
 833
 834         /* FIXME: Check authentication here. This extension needs to be
 835          * pre-handled. */
 836
 837         /* Figure out if this is local */
 838         target_addr = (packet_types[hdr->type].type == PACKET_REPLY) ? &pp.src_proto : &pp.dst_proto;
 839
 840         if (sockunion_same(&pp.src_proto, &pp.dst_proto))
 841                 pp.route_type = NHRP_ROUTE_LOCAL;
 842         else
 843                 pp.route_type = nhrp_route_address(pp.ifp, target_addr, &pp.route_prefix, &peer);
 844
 845         switch (pp.route_type) {
 846         case NHRP_ROUTE_LOCAL:
 847                 nhrp_packet_debug(zb, "!LOCAL");
 848                 if (packet_types[hdr->type].type == PACKET_REPLY) {
 849                         reqid = nhrp_reqid_lookup(&nhrp_packet_reqid, htonl(hdr->u.request_id));
 850                         if (reqid) {
 851                                 reqid->cb(reqid, &pp);
 852                                 break;
 853                         } else {
 854                                 nhrp_packet_debug(zb, "!UNKNOWN-REQID");
 855                                 /* FIXME: send error-indication */
 856                         }
 857                 }
 858         case NHRP_ROUTE_OFF_NBMA:
 859                 if (packet_types[hdr->type].handler) {
 860                         packet_types[hdr->type].handler(&pp);
 861                         break;
 862                 }
 863                 break;
 864         case NHRP_ROUTE_NBMA_NEXTHOP:
 865                 nhrp_peer_forward(peer, &pp);
 866                 break;
 867         case NHRP_ROUTE_BLACKHOLE:
 868                 break;
 869         }
 870
 871 drop:
 872         if (info) {
 873                 zlog_info("From %s: error: %s",
 874                           sockunion2str(&vc->remote.nbma, buf[0], sizeof buf[0]),
 875                           info);
 876         }
 877         if (peer) nhrp_peer_unref(peer);
 878         zbuf_free(zb);
 879 }