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
 102         if (zclient->sock < 0)
 103                 return;
 104
 105         memset(&api, 0, sizeof(api));
 106         api.type = ZEBRA_ROUTE_NHRP;
 107         api.safi = SAFI_UNICAST;
 108         api.vrf_id = VRF_DEFAULT;
 109         api.prefix = *p;
 110
 111         switch (type) {
 112         case NHRP_CACHE_NEGATIVE:
 113                 zapi_route_set_blackhole(&api, BLACKHOLE_REJECT);
 114                 ifp = NULL;
 115                 nexthop = NULL;
 116                 break;
 117         case NHRP_CACHE_DYNAMIC:
 118         case NHRP_CACHE_NHS:
 119         case NHRP_CACHE_STATIC:
 120                 /* Regular route, so these are announced
 121                  * to other routing daemons */
 122                 break;
 123         default:
 124                 SET_FLAG(api.flags, ZEBRA_FLAG_FIB_OVERRIDE);
 125                 break;
 126         }
 127         SET_FLAG(api.flags, ZEBRA_FLAG_ALLOW_RECURSION);
 128
 129         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 130         api.nexthop_num = 1;
 131         api_nh = &api.nexthops[0];
 132         api_nh->vrf_id = VRF_DEFAULT;
 133
 134         switch (api.prefix.family) {
 135         case AF_INET:
 136                 if (nexthop) {
 137                         api_nh->gate.ipv4 = nexthop->sin.sin_addr;
 138                         api_nh->type = NEXTHOP_TYPE_IPV4;
 139                 }
 140                 if (ifp) {
 141                         api_nh->ifindex = ifp->ifindex;
 142                         if (api_nh->type == NEXTHOP_TYPE_IPV4)
 143                                 api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 144                         else
 145                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 146                 }
 147                 break;
 148         case AF_INET6:
 149                 if (nexthop) {
 150                         api_nh->gate.ipv6 = nexthop->sin6.sin6_addr;
 151                         api_nh->type = NEXTHOP_TYPE_IPV6;
 152                 }
 153                 if (ifp) {
 154                         api_nh->ifindex = ifp->ifindex;
 155                         if (api_nh->type == NEXTHOP_TYPE_IPV6)
 156                                 api_nh->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 157                         else
 158                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 159                 }
 160                 break;
 161         }
 162         if (mtu) {
 163                 SET_FLAG(api.message, ZAPI_MESSAGE_MTU);
 164                 api.mtu = mtu;
 165         }
 166
 167         if (unlikely(debug_flags & NHRP_DEBUG_ROUTE)) {
 168                 char buf[PREFIX_STRLEN];
 169
 170                 zlog_debug(
 171                         "Zebra send: route %s %pFX nexthop %s metric %u count %d dev %s",
 172                         add ? "add" : "del", &api.prefix,
 173                         nexthop ? inet_ntop(api.prefix.family, &api_nh->gate,
 174                                             buf, sizeof(buf))
 175                                 : "<onlink>",
 176                         api.metric, api.nexthop_num, ifp ? ifp->name : "none");
 177         }
 178
 179         zclient_route_send(add ? ZEBRA_ROUTE_ADD : ZEBRA_ROUTE_DELETE, zclient,
 180                            &api);
 181 }
 182
 183 int nhrp_route_read(ZAPI_CALLBACK_ARGS)
 184 {
 185         struct zapi_route api;
 186         struct zapi_nexthop *api_nh;
 187         struct interface *ifp = NULL;
 188         union sockunion nexthop_addr;
 189         char buf[PREFIX_STRLEN];
 190         int added;
 191
 192         if (zapi_route_decode(zclient->ibuf, &api) < 0)
 193                 return -1;
 194
 195         /* we completely ignore srcdest routes for now. */
 196         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 197                 return 0;
 198
 199         /* ignore our routes */
 200         if (api.type == ZEBRA_ROUTE_NHRP)
 201                 return 0;
 202
 203         sockunion_family(&nexthop_addr) = AF_UNSPEC;
 204         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
 205                 api_nh = &api.nexthops[0];
 206
 207                 nexthop_addr.sa.sa_family = api.prefix.family;
 208                 switch (nexthop_addr.sa.sa_family) {
 209                 case AF_INET:
 210                         nexthop_addr.sin.sin_addr = api_nh->gate.ipv4;
 211                         break;
 212                 case AF_INET6:
 213                         nexthop_addr.sin6.sin6_addr = api_nh->gate.ipv6;
 214                         break;
 215                 }
 216
 217                 if (api_nh->ifindex != IFINDEX_INTERNAL)
 218                         ifp = if_lookup_by_index(api_nh->ifindex, VRF_DEFAULT);
 219         }
 220
 221         added = (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
 222         debugf(NHRP_DEBUG_ROUTE, "if-route-%s: %pFX via %s dev %s",
 223                added ? "add" : "del", &api.prefix,
 224                sockunion2str(&nexthop_addr, buf, sizeof(buf)),
 225                ifp ? ifp->name : "(none)");
 226
 227         nhrp_route_update_zebra(&api.prefix, &nexthop_addr, added ? ifp : NULL);
 228         nhrp_shortcut_prefix_change(&api.prefix, !added);
 229
 230         return 0;
 231 }
 232
 233 int nhrp_route_get_nexthop(const union sockunion *addr, struct prefix *p,
 234                            union sockunion *via, struct interface **ifp)
 235 {
 236         struct route_node *rn;
 237         struct route_info *ri;
 238         struct prefix lookup;
 239         afi_t afi = family2afi(sockunion_family(addr));
 240
 241         sockunion2hostprefix(addr, &lookup);
 242
 243         rn = route_node_match(zebra_rib[afi], &lookup);
 244         if (!rn)
 245                 return 0;
 246
 247         ri = rn->info;
 248         if (ri->nhrp_ifp) {
 249                 debugf(NHRP_DEBUG_ROUTE, "lookup %pFX: nhrp_if=%s", &lookup,
 250                        ri->nhrp_ifp->name);
 251
 252                 if (via)
 253                         sockunion_family(via) = AF_UNSPEC;
 254                 if (ifp)
 255                         *ifp = ri->nhrp_ifp;
 256         } else {
 257                 debugf(NHRP_DEBUG_ROUTE, "lookup %pFX: zebra route dev %s",
 258                        &lookup, ri->ifp ? ri->ifp->name : "(none)");
 259
 260                 if (via)
 261                         *via = ri->via;
 262                 if (ifp)
 263                         *ifp = ri->ifp;
 264         }
 265         if (p)
 266                 *p = rn->p;
 267         route_unlock_node(rn);
 268         return 1;
 269 }
 270
 271 enum nhrp_route_type nhrp_route_address(struct interface *in_ifp,
 272                                         union sockunion *addr, struct prefix *p,
 273                                         struct nhrp_peer **peer)
 274 {
 275         struct interface *ifp = in_ifp;
 276         struct nhrp_interface *nifp;
 277         struct nhrp_cache *c;
 278         union sockunion via[4];
 279         uint32_t network_id = 0;
 280         afi_t afi = family2afi(sockunion_family(addr));
 281         int i;
 282
 283         if (ifp) {
 284                 nifp = ifp->info;
 285                 network_id = nifp->afi[afi].network_id;
 286
 287                 c = nhrp_cache_get(ifp, addr, 0);
 288                 if (c && c->cur.type == NHRP_CACHE_LOCAL) {
 289                         if (p)
 290                                 memset(p, 0, sizeof(*p));
 291                         return NHRP_ROUTE_LOCAL;
 292                 }
 293         }
 294
 295         for (i = 0; i < 4; i++) {
 296                 if (!nhrp_route_get_nexthop(addr, p, &via[i], &ifp))
 297                         return NHRP_ROUTE_BLACKHOLE;
 298                 if (ifp) {
 299                         /* Departing from nbma network? */
 300                         nifp = ifp->info;
 301                         if (network_id
 302                             && network_id != nifp->afi[afi].network_id)
 303                                 return NHRP_ROUTE_OFF_NBMA;
 304                 }
 305                 if (sockunion_family(&via[i]) == AF_UNSPEC)
 306                         break;
 307                 /* Resolve via node, but return the prefix of first match */
 308                 addr = &via[i];
 309                 p = NULL;
 310         }
 311
 312         if (ifp) {
 313                 c = nhrp_cache_get(ifp, addr, 0);
 314                 if (c && c->cur.type >= NHRP_CACHE_DYNAMIC) {
 315                         if (p)
 316                                 memset(p, 0, sizeof(*p));
 317                         if (c->cur.type == NHRP_CACHE_LOCAL)
 318                                 return NHRP_ROUTE_LOCAL;
 319                         if (peer)
 320                                 *peer = nhrp_peer_ref(c->cur.peer);
 321                         return NHRP_ROUTE_NBMA_NEXTHOP;
 322                 }
 323         }
 324
 325         return NHRP_ROUTE_BLACKHOLE;
 326 }
 327
 328 static void nhrp_zebra_connected(struct zclient *zclient)
 329 {
 330         zclient_send_reg_requests(zclient, VRF_DEFAULT);
 331         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP,
 332                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 333         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP6,
 334                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 335 }
 336
 337 void nhrp_zebra_init(void)
 338 {
 339         zebra_rib[AFI_IP] = route_table_init();
 340         zebra_rib[AFI_IP6] = route_table_init();
 341
 342         zclient = zclient_new(master, &zclient_options_default);
 343         zclient->zebra_connected = nhrp_zebra_connected;
 344         zclient->interface_address_add = nhrp_interface_address_add;
 345         zclient->interface_address_delete = nhrp_interface_address_delete;
 346         zclient->redistribute_route_add = nhrp_route_read;
 347         zclient->redistribute_route_del = nhrp_route_read;
 348
 349         zclient_init(zclient, ZEBRA_ROUTE_NHRP, 0, &nhrpd_privs);
 350 }
 351
 352 static void nhrp_table_node_cleanup(struct route_table *table,
 353                                     struct route_node *node)
 354 {
 355         if (!node->info)
 356                 return;
 357
 358         XFREE(MTYPE_NHRP_ROUTE, node->info);
 359 }
 360
 361 void nhrp_zebra_terminate(void)
 362 {
 363         zclient_stop(zclient);
 364         zclient_free(zclient);
 365
 366         zebra_rib[AFI_IP]->cleanup = nhrp_table_node_cleanup;
 367         zebra_rib[AFI_IP6]->cleanup = nhrp_table_node_cleanup;
 368         route_table_finish(zebra_rib[AFI_IP]);
 369         route_table_finish(zebra_rib[AFI_IP6]);
 370 }