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 #include "nhrpd.h"
  11 #include "table.h"
  12 #include "memory.h"
  13 #include "stream.h"
  14 #include "log.h"
  15 #include "zclient.h"
  16
  17 DEFINE_MTYPE_STATIC(NHRPD, NHRP_ROUTE, "NHRP routing entry")
  18
  19 static struct zclient *zclient;
  20 static struct route_table *zebra_rib[AFI_MAX];
  21
  22 struct route_info {
  23         union sockunion via;
  24         struct interface *ifp;
  25         struct interface *nhrp_ifp;
  26 };
  27
  28 static struct route_node *nhrp_route_update_get(const struct prefix *p,
  29                                                 int create)
  30 {
  31         struct route_node *rn;
  32         afi_t afi = family2afi(PREFIX_FAMILY(p));
  33
  34         if (!zebra_rib[afi])
  35                 return NULL;
  36
  37         if (create) {
  38                 rn = route_node_get(zebra_rib[afi], p);
  39                 if (!rn->info) {
  40                         rn->info = XCALLOC(MTYPE_NHRP_ROUTE,
  41                                            sizeof(struct route_info));
  42                         route_lock_node(rn);
  43                 }
  44                 return rn;
  45         } else {
  46                 return route_node_lookup(zebra_rib[afi], p);
  47         }
  48 }
  49
  50 static void nhrp_route_update_put(struct route_node *rn)
  51 {
  52         struct route_info *ri = rn->info;
  53
  54         if (!ri->ifp && !ri->nhrp_ifp
  55             && sockunion_family(&ri->via) == AF_UNSPEC) {
  56                 XFREE(MTYPE_NHRP_ROUTE, rn->info);
  57                 rn->info = NULL;
  58                 route_unlock_node(rn);
  59         }
  60         route_unlock_node(rn);
  61 }
  62
  63 static void nhrp_route_update_zebra(const struct prefix *p,
  64                                     union sockunion *nexthop,
  65                                     struct interface *ifp)
  66 {
  67         struct route_node *rn;
  68         struct route_info *ri;
  69
  70         rn = nhrp_route_update_get(
  71                 p, (sockunion_family(nexthop) != AF_UNSPEC) || ifp);
  72         if (rn) {
  73                 ri = rn->info;
  74                 ri->via = *nexthop;
  75                 ri->ifp = ifp;
  76                 nhrp_route_update_put(rn);
  77         }
  78 }
  79
  80 void nhrp_route_update_nhrp(const struct prefix *p, struct interface *ifp)
  81 {
  82         struct route_node *rn;
  83         struct route_info *ri;
  84
  85         rn = nhrp_route_update_get(p, ifp != NULL);
  86         if (rn) {
  87                 ri = rn->info;
  88                 ri->nhrp_ifp = ifp;
  89                 nhrp_route_update_put(rn);
  90         }
  91 }
  92
  93 void nhrp_route_announce(int add, enum nhrp_cache_type type,
  94                          const struct prefix *p, struct interface *ifp,
  95                          const union sockunion *nexthop, uint32_t mtu)
  96 {
  97         struct zapi_route api;
  98         struct zapi_nexthop *api_nh;
  99
 100         if (zclient->sock < 0)
 101                 return;
 102
 103         memset(&api, 0, sizeof(api));
 104         api.type = ZEBRA_ROUTE_NHRP;
 105         api.safi = SAFI_UNICAST;
 106         api.vrf_id = VRF_DEFAULT;
 107         api.prefix = *p;
 108
 109         switch (type) {
 110         case NHRP_CACHE_NEGATIVE:
 111                 zapi_route_set_blackhole(&api, BLACKHOLE_REJECT);
 112                 ifp = NULL;
 113                 nexthop = NULL;
 114                 break;
 115         case NHRP_CACHE_DYNAMIC:
 116         case NHRP_CACHE_NHS:
 117         case NHRP_CACHE_STATIC:
 118                 /* Regular route, so these are announced
 119                  * to other routing daemons */
 120                 break;
 121         default:
 122                 SET_FLAG(api.flags, ZEBRA_FLAG_FIB_OVERRIDE);
 123                 break;
 124         }
 125         SET_FLAG(api.flags, ZEBRA_FLAG_ALLOW_RECURSION);
 126
 127         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 128         api.nexthop_num = 1;
 129         api_nh = &api.nexthops[0];
 130         api_nh->vrf_id = VRF_DEFAULT;
 131
 132         switch (api.prefix.family) {
 133         case AF_INET:
 134                 if (nexthop) {
 135                         api_nh->gate.ipv4 = nexthop->sin.sin_addr;
 136                         api_nh->type = NEXTHOP_TYPE_IPV4;
 137                 }
 138                 if (ifp) {
 139                         api_nh->ifindex = ifp->ifindex;
 140                         if (api_nh->type == NEXTHOP_TYPE_IPV4)
 141                                 api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 142                         else
 143                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 144                 }
 145                 break;
 146         case AF_INET6:
 147                 if (nexthop) {
 148                         api_nh->gate.ipv6 = nexthop->sin6.sin6_addr;
 149                         api_nh->type = NEXTHOP_TYPE_IPV6;
 150                 }
 151                 if (ifp) {
 152                         api_nh->ifindex = ifp->ifindex;
 153                         if (api_nh->type == NEXTHOP_TYPE_IPV6)
 154                                 api_nh->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 155                         else
 156                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 157                 }
 158                 break;
 159         }
 160         if (mtu) {
 161                 SET_FLAG(api.message, ZAPI_MESSAGE_MTU);
 162                 api.mtu = mtu;
 163         }
 164
 165         if (unlikely(debug_flags & NHRP_DEBUG_ROUTE)) {
 166                 char buf[2][PREFIX_STRLEN];
 167
 168                 prefix2str(&api.prefix, buf[0], sizeof(buf[0]));
 169                 zlog_debug(
 170                         "Zebra send: route %s %s nexthop %s metric %u"
 171                         " count %d dev %s",
 172                         add ? "add" : "del", buf[0],
 173                         nexthop ? inet_ntop(api.prefix.family, &api_nh->gate,
 174                                             buf[1], sizeof(buf[1]))
 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(int cmd, struct zclient *zclient, zebra_size_t length,
 184                     vrf_id_t vrf_id)
 185 {
 186         struct zapi_route api;
 187         struct zapi_nexthop *api_nh;
 188         struct interface *ifp = NULL;
 189         union sockunion nexthop_addr;
 190         char buf[2][PREFIX_STRLEN];
 191         int added;
 192
 193         if (zapi_route_decode(zclient->ibuf, &api) < 0)
 194                 return -1;
 195
 196         /* we completely ignore srcdest routes for now. */
 197         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 198                 return 0;
 199
 200         sockunion_family(&nexthop_addr) = AF_UNSPEC;
 201         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
 202                 api_nh = &api.nexthops[0];
 203
 204                 nexthop_addr.sa.sa_family = api.prefix.family;
 205                 switch (nexthop_addr.sa.sa_family) {
 206                 case AF_INET:
 207                         nexthop_addr.sin.sin_addr = api_nh->gate.ipv4;
 208                         break;
 209                 case AF_INET6:
 210                         nexthop_addr.sin6.sin6_addr = api_nh->gate.ipv6;
 211                         break;
 212                 }
 213
 214                 if (api_nh->ifindex != IFINDEX_INTERNAL)
 215                         ifp = if_lookup_by_index(api_nh->ifindex, VRF_DEFAULT);
 216         }
 217
 218         added = (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
 219         debugf(NHRP_DEBUG_ROUTE, "if-route-%s: %s via %s dev %s",
 220                added ? "add" : "del",
 221                prefix2str(&api.prefix, buf[0], sizeof buf[0]),
 222                sockunion2str(&nexthop_addr, buf[1], sizeof buf[1]),
 223                ifp ? ifp->name : "(none)");
 224
 225         nhrp_route_update_zebra(&api.prefix, &nexthop_addr, ifp);
 226         nhrp_shortcut_prefix_change(&api.prefix, !added);
 227
 228         return 0;
 229 }
 230
 231 int nhrp_route_get_nexthop(const union sockunion *addr, struct prefix *p,
 232                            union sockunion *via, struct interface **ifp)
 233 {
 234         struct route_node *rn;
 235         struct route_info *ri;
 236         struct prefix lookup;
 237         afi_t afi = family2afi(sockunion_family(addr));
 238         char buf[PREFIX_STRLEN];
 239
 240         sockunion2hostprefix(addr, &lookup);
 241
 242         rn = route_node_match(zebra_rib[afi], &lookup);
 243         if (!rn)
 244                 return 0;
 245
 246         ri = rn->info;
 247         if (ri->nhrp_ifp) {
 248                 debugf(NHRP_DEBUG_ROUTE, "lookup %s: nhrp_if=%s",
 249                        prefix2str(&lookup, buf, sizeof buf),
 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 %s: zebra route dev %s",
 258                        prefix2str(&lookup, buf, sizeof buf),
 259                        ri->ifp ? ri->ifp->name : "(none)");
 260
 261                 if (via)
 262                         *via = ri->via;
 263                 if (ifp)
 264                         *ifp = ri->ifp;
 265         }
 266         if (p)
 267                 *p = rn->p;
 268         route_unlock_node(rn);
 269         return 1;
 270 }
 271
 272 enum nhrp_route_type nhrp_route_address(struct interface *in_ifp,
 273                                         union sockunion *addr, struct prefix *p,
 274                                         struct nhrp_peer **peer)
 275 {
 276         struct interface *ifp = in_ifp;
 277         struct nhrp_interface *nifp;
 278         struct nhrp_cache *c;
 279         union sockunion via[4];
 280         uint32_t network_id = 0;
 281         afi_t afi = family2afi(sockunion_family(addr));
 282         int i;
 283
 284         if (ifp) {
 285                 nifp = ifp->info;
 286                 network_id = nifp->afi[afi].network_id;
 287
 288                 c = nhrp_cache_get(ifp, addr, 0);
 289                 if (c && c->cur.type == NHRP_CACHE_LOCAL) {
 290                         if (p)
 291                                 memset(p, 0, sizeof(*p));
 292                         return NHRP_ROUTE_LOCAL;
 293                 }
 294         }
 295
 296         for (i = 0; i < 4; i++) {
 297                 if (!nhrp_route_get_nexthop(addr, p, &via[i], &ifp))
 298                         return NHRP_ROUTE_BLACKHOLE;
 299                 if (ifp) {
 300                         /* Departing from nbma network? */
 301                         nifp = ifp->info;
 302                         if (network_id
 303                             && network_id != nifp->afi[afi].network_id)
 304                                 return NHRP_ROUTE_OFF_NBMA;
 305                 }
 306                 if (sockunion_family(&via[i]) == AF_UNSPEC)
 307                         break;
 308                 /* Resolve via node, but return the prefix of first match */
 309                 addr = &via[i];
 310                 p = NULL;
 311         }
 312
 313         if (ifp) {
 314                 c = nhrp_cache_get(ifp, addr, 0);
 315                 if (c && c->cur.type >= NHRP_CACHE_DYNAMIC) {
 316                         if (p)
 317                                 memset(p, 0, sizeof(*p));
 318                         if (c->cur.type == NHRP_CACHE_LOCAL)
 319                                 return NHRP_ROUTE_LOCAL;
 320                         if (peer)
 321                                 *peer = nhrp_peer_ref(c->cur.peer);
 322                         return NHRP_ROUTE_NBMA_NEXTHOP;
 323                 }
 324         }
 325
 326         return NHRP_ROUTE_BLACKHOLE;
 327 }
 328
 329 static void nhrp_zebra_connected(struct zclient *zclient)
 330 {
 331         zclient_send_reg_requests(zclient, VRF_DEFAULT);
 332         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP,
 333                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 334         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP6,
 335                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 336 }
 337
 338 void nhrp_zebra_init(void)
 339 {
 340         zebra_rib[AFI_IP] = route_table_init();
 341         zebra_rib[AFI_IP6] = route_table_init();
 342
 343         zclient = zclient_new_notify(master, &zclient_options_default);
 344         zclient->zebra_connected = nhrp_zebra_connected;
 345         zclient->interface_add = nhrp_interface_add;
 346         zclient->interface_delete = nhrp_interface_delete;
 347         zclient->interface_up = nhrp_interface_up;
 348         zclient->interface_down = nhrp_interface_down;
 349         zclient->interface_address_add = nhrp_interface_address_add;
 350         zclient->interface_address_delete = nhrp_interface_address_delete;
 351         zclient->redistribute_route_add = nhrp_route_read;
 352         zclient->redistribute_route_del = nhrp_route_read;
 353
 354         zclient_init(zclient, ZEBRA_ROUTE_NHRP, 0, &nhrpd_privs);
 355 }
 356
 357 void nhrp_zebra_terminate(void)
 358 {
 359         zclient_stop(zclient);
 360         zclient_free(zclient);
 361         route_table_finish(zebra_rib[AFI_IP]);
 362         route_table_finish(zebra_rib[AFI_IP6]);
 363 }