nhrpd/nhrp_route.c

   1 /* NHRP routing 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 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #include "nhrpd.h"
  15 #include "table.h"
  16 #include "memory.h"
  17 #include "stream.h"
  18 #include "log.h"
  19 #include "zclient.h"
  20
  21 DEFINE_MTYPE_STATIC(NHRPD, NHRP_ROUTE, "NHRP routing entry")
  22
  23 static struct zclient *zclient;
  24 static struct route_table *zebra_rib[AFI_MAX];
  25
  26 struct route_info {
  27         union sockunion via;
  28         struct interface *ifp;
  29         struct interface *nhrp_ifp;
  30 };
  31
  32 static struct route_node *nhrp_route_update_get(const struct prefix *p,
  33                                                 int create)
  34 {
  35         struct route_node *rn;
  36         afi_t afi = family2afi(PREFIX_FAMILY(p));
  37
  38         if (!zebra_rib[afi])
  39                 return NULL;
  40
  41         if (create) {
  42                 rn = route_node_get(zebra_rib[afi], p);
  43                 if (!rn->info) {
  44                         rn->info = XCALLOC(MTYPE_NHRP_ROUTE,
  45                                            sizeof(struct route_info));
  46                         route_lock_node(rn);
  47                 }
  48                 return rn;
  49         } else {
  50                 return route_node_lookup(zebra_rib[afi], p);
  51         }
  52 }
  53
  54 static void nhrp_route_update_put(struct route_node *rn)
  55 {
  56         struct route_info *ri = rn->info;
  57
  58         if (!ri->ifp && !ri->nhrp_ifp
  59             && sockunion_is_null(&ri->via)) {
  60                 XFREE(MTYPE_NHRP_ROUTE, rn->info);
  61                 route_unlock_node(rn);
  62         }
  63         route_unlock_node(rn);
  64 }
  65
  66 static void nhrp_route_update_zebra(const struct prefix *p,
  67                                     union sockunion *nexthop,
  68                                     struct interface *ifp)
  69 {
  70         struct route_node *rn;
  71         struct route_info *ri;
  72
  73         rn = nhrp_route_update_get(p, !sockunion_is_null(nexthop) || ifp);
  74         if (rn) {
  75                 ri = rn->info;
  76                 ri->via = *nexthop;
  77                 ri->ifp = ifp;
  78                 nhrp_route_update_put(rn);
  79         }
  80 }
  81
  82 void nhrp_route_update_nhrp(const struct prefix *p, struct interface *ifp)
  83 {
  84         struct route_node *rn;
  85         struct route_info *ri;
  86
  87         rn = nhrp_route_update_get(p, ifp != NULL);
  88         if (rn) {
  89                 ri = rn->info;
  90                 ri->nhrp_ifp = ifp;
  91                 nhrp_route_update_put(rn);
  92         }
  93 }
  94
  95 void nhrp_route_announce(int add, enum nhrp_cache_type type,
  96                          const struct prefix *p, struct interface *ifp,
  97                          const union sockunion *nexthop, uint32_t mtu)
  98 {
  99         struct zapi_route api;
 100         struct zapi_nexthop *api_nh;
 101         union sockunion *nexthop_ref = (union sockunion *)nexthop;
 102
 103         if (zclient->sock < 0)
 104                 return;
 105
 106         memset(&api, 0, sizeof(api));
 107         api.type = ZEBRA_ROUTE_NHRP;
 108         api.safi = SAFI_UNICAST;
 109         api.vrf_id = VRF_DEFAULT;
 110         api.prefix = *p;
 111
 112         switch (type) {
 113         case NHRP_CACHE_NEGATIVE:
 114                 zapi_route_set_blackhole(&api, BLACKHOLE_REJECT);
 115                 ifp = NULL;
 116                 nexthop = NULL;
 117                 break;
 118         case NHRP_CACHE_DYNAMIC:
 119         case NHRP_CACHE_NHS:
 120         case NHRP_CACHE_STATIC:
 121                 /* Regular route, so these are announced
 122                  * to other routing daemons */
 123                 break;
 124         default:
 125                 SET_FLAG(api.flags, ZEBRA_FLAG_FIB_OVERRIDE);
 126                 break;
 127         }
 128         SET_FLAG(api.flags, ZEBRA_FLAG_ALLOW_RECURSION);
 129
 130         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 131         api.nexthop_num = 1;
 132         api_nh = &api.nexthops[0];
 133         api_nh->vrf_id = VRF_DEFAULT;
 134
 135         switch (api.prefix.family) {
 136         case AF_INET:
 137                 if (api.prefix.prefixlen == IPV4_MAX_BITLEN &&
 138                     nexthop_ref &&
 139                     memcmp(&nexthop_ref->sin.sin_addr, &api.prefix.u.prefix4,
 140                            sizeof(struct in_addr)) == 0) {
 141                         nexthop_ref = NULL;
 142                 }
 143                 if (nexthop_ref) {
 144                         api_nh->gate.ipv4 = nexthop_ref->sin.sin_addr;
 145                         api_nh->type = NEXTHOP_TYPE_IPV4;
 146                 }
 147                 if (ifp) {
 148                         api_nh->ifindex = ifp->ifindex;
 149                         if (api_nh->type == NEXTHOP_TYPE_IPV4)
 150                                 api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 151                         else
 152                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 153                 }
 154                 break;
 155         case AF_INET6:
 156                 if (api.prefix.prefixlen == IPV6_MAX_BITLEN &&
 157                     nexthop_ref &&
 158                     memcmp(&nexthop_ref->sin6.sin6_addr, &api.prefix.u.prefix6,
 159                            sizeof(struct in6_addr)) == 0) {
 160                         nexthop_ref = NULL;
 161                 }
 162                 if (nexthop_ref) {
 163                         api_nh->gate.ipv6 = nexthop_ref->sin6.sin6_addr;
 164                         api_nh->type = NEXTHOP_TYPE_IPV6;
 165                 }
 166                 if (ifp) {
 167                         api_nh->ifindex = ifp->ifindex;
 168                         if (api_nh->type == NEXTHOP_TYPE_IPV6)
 169                                 api_nh->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 170                         else
 171                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 172                 }
 173                 break;
 174         }
 175         if (mtu) {
 176                 SET_FLAG(api.message, ZAPI_MESSAGE_MTU);
 177                 api.mtu = mtu;
 178         }
 179
 180         if (unlikely(debug_flags & NHRP_DEBUG_ROUTE)) {
 181                 char buf[PREFIX_STRLEN];
 182
 183                 zlog_debug(
 184                         "Zebra send: route %s %pFX nexthop %s metric %u count %d dev %s",
 185                         add ? "add" : "del", &api.prefix,
 186                         nexthop_ref ? inet_ntop(api.prefix.family,
 187                                                 &api_nh->gate,
 188                                                 buf, sizeof(buf))
 189                                 : "<onlink>",
 190                         api.metric, api.nexthop_num, ifp ? ifp->name : "none");
 191         }
 192
 193         zclient_route_send(add ? ZEBRA_ROUTE_ADD : ZEBRA_ROUTE_DELETE, zclient,
 194                            &api);
 195 }
 196
 197 int nhrp_route_read(ZAPI_CALLBACK_ARGS)
 198 {
 199         struct zapi_route api;
 200         struct zapi_nexthop *api_nh;
 201         struct interface *ifp = NULL;
 202         union sockunion nexthop_addr;
 203         char buf[PREFIX_STRLEN];
 204         int added;
 205
 206         if (zapi_route_decode(zclient->ibuf, &api) < 0)
 207                 return -1;
 208
 209         /* we completely ignore srcdest routes for now. */
 210         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 211                 return 0;
 212
 213         /* ignore our routes */
 214         if (api.type == ZEBRA_ROUTE_NHRP)
 215                 return 0;
 216
 217         sockunion_family(&nexthop_addr) = AF_UNSPEC;
 218         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
 219                 api_nh = &api.nexthops[0];
 220
 221                 nexthop_addr.sa.sa_family = api.prefix.family;
 222                 switch (nexthop_addr.sa.sa_family) {
 223                 case AF_INET:
 224                         nexthop_addr.sin.sin_addr = api_nh->gate.ipv4;
 225                         break;
 226                 case AF_INET6:
 227                         nexthop_addr.sin6.sin6_addr = api_nh->gate.ipv6;
 228                         break;
 229                 }
 230
 231                 if (api_nh->ifindex != IFINDEX_INTERNAL)
 232                         ifp = if_lookup_by_index(api_nh->ifindex, VRF_DEFAULT);
 233         }
 234
 235         added = (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
 236         debugf(NHRP_DEBUG_ROUTE, "if-route-%s: %pFX via %s dev %s",
 237                added ? "add" : "del", &api.prefix,
 238                sockunion2str(&nexthop_addr, buf, sizeof(buf)),
 239                ifp ? ifp->name : "(none)");
 240
 241         nhrp_route_update_zebra(&api.prefix, &nexthop_addr, added ? ifp : NULL);
 242         nhrp_shortcut_prefix_change(&api.prefix, !added);
 243
 244         return 0;
 245 }
 246
 247 int nhrp_route_get_nexthop(const union sockunion *addr, struct prefix *p,
 248                            union sockunion *via, struct interface **ifp)
 249 {
 250         struct route_node *rn;
 251         struct route_info *ri;
 252         struct prefix lookup;
 253         afi_t afi = family2afi(sockunion_family(addr));
 254
 255         sockunion2hostprefix(addr, &lookup);
 256
 257         rn = route_node_match(zebra_rib[afi], &lookup);
 258         if (!rn)
 259                 return 0;
 260
 261         ri = rn->info;
 262         if (ri->nhrp_ifp) {
 263                 debugf(NHRP_DEBUG_ROUTE, "lookup %pFX: nhrp_if=%s", &lookup,
 264                        ri->nhrp_ifp->name);
 265
 266                 if (via)
 267                         sockunion_family(via) = AF_UNSPEC;
 268                 if (ifp)
 269                         *ifp = ri->nhrp_ifp;
 270         } else {
 271                 debugf(NHRP_DEBUG_ROUTE, "lookup %pFX: zebra route dev %s",
 272                        &lookup, ri->ifp ? ri->ifp->name : "(none)");
 273
 274                 if (via)
 275                         *via = ri->via;
 276                 if (ifp)
 277                         *ifp = ri->ifp;
 278         }
 279         if (p)
 280                 *p = rn->p;
 281         route_unlock_node(rn);
 282         return 1;
 283 }
 284
 285 enum nhrp_route_type nhrp_route_address(struct interface *in_ifp,
 286                                         union sockunion *addr, struct prefix *p,
 287                                         struct nhrp_peer **peer)
 288 {
 289         struct interface *ifp = in_ifp;
 290         struct nhrp_interface *nifp;
 291         struct nhrp_cache *c;
 292         union sockunion via[4];
 293         uint32_t network_id = 0;
 294         afi_t afi = family2afi(sockunion_family(addr));
 295         int i;
 296
 297         if (ifp) {
 298                 nifp = ifp->info;
 299                 network_id = nifp->afi[afi].network_id;
 300
 301                 c = nhrp_cache_get(ifp, addr, 0);
 302                 if (c && c->cur.type == NHRP_CACHE_LOCAL) {
 303                         if (p)
 304                                 memset(p, 0, sizeof(*p));
 305                         return NHRP_ROUTE_LOCAL;
 306                 }
 307         }
 308
 309         for (i = 0; i < 4; i++) {
 310                 if (!nhrp_route_get_nexthop(addr, p, &via[i], &ifp))
 311                         return NHRP_ROUTE_BLACKHOLE;
 312                 if (ifp) {
 313                         /* Departing from nbma network? */
 314                         nifp = ifp->info;
 315                         if (network_id
 316                             && network_id != nifp->afi[afi].network_id)
 317                                 return NHRP_ROUTE_OFF_NBMA;
 318                 }
 319                 if (sockunion_family(&via[i]) == AF_UNSPEC)
 320                         break;
 321                 /* Resolve via node, but return the prefix of first match */
 322                 addr = &via[i];
 323                 p = NULL;
 324         }
 325
 326         if (ifp) {
 327                 c = nhrp_cache_get(ifp, addr, 0);
 328                 if (c && c->cur.type >= NHRP_CACHE_DYNAMIC) {
 329                         if (p)
 330                                 memset(p, 0, sizeof(*p));
 331                         if (c->cur.type == NHRP_CACHE_LOCAL)
 332                                 return NHRP_ROUTE_LOCAL;
 333                         if (peer)
 334                                 *peer = nhrp_peer_ref(c->cur.peer);
 335                         return NHRP_ROUTE_NBMA_NEXTHOP;
 336                 }
 337         }
 338
 339         return NHRP_ROUTE_BLACKHOLE;
 340 }
 341
 342 static void nhrp_zebra_connected(struct zclient *zclient)
 343 {
 344         zclient_send_reg_requests(zclient, VRF_DEFAULT);
 345         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP,
 346                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 347         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP6,
 348                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 349 }
 350
 351 void nhrp_zebra_init(void)
 352 {
 353         zebra_rib[AFI_IP] = route_table_init();
 354         zebra_rib[AFI_IP6] = route_table_init();
 355
 356         zclient = zclient_new(master, &zclient_options_default);
 357         zclient->zebra_connected = nhrp_zebra_connected;
 358         zclient->interface_address_add = nhrp_interface_address_add;
 359         zclient->interface_address_delete = nhrp_interface_address_delete;
 360         zclient->redistribute_route_add = nhrp_route_read;
 361         zclient->redistribute_route_del = nhrp_route_read;
 362
 363         zclient_init(zclient, ZEBRA_ROUTE_NHRP, 0, &nhrpd_privs);
 364 }
 365
 366 static void nhrp_table_node_cleanup(struct route_table *table,
 367                                     struct route_node *node)
 368 {
 369         if (!node->info)
 370                 return;
 371
 372         XFREE(MTYPE_NHRP_ROUTE, node->info);
 373 }
 374
 375 void nhrp_zebra_terminate(void)
 376 {
 377         zclient_stop(zclient);
 378         zclient_free(zclient);
 379
 380         zebra_rib[AFI_IP]->cleanup = nhrp_table_node_cleanup;
 381         zebra_rib[AFI_IP6]->cleanup = nhrp_table_node_cleanup;
 382         route_table_finish(zebra_rib[AFI_IP]);
 383         route_table_finish(zebra_rib[AFI_IP6]);
 384 }