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_family(&ri->via) == AF_UNSPEC) {
  60                 XFREE(MTYPE_NHRP_ROUTE, rn->info);
  61                 rn->info = NULL;
  62                 route_unlock_node(rn);
  63         }
  64         route_unlock_node(rn);
  65 }
  66
  67 static void nhrp_route_update_zebra(const struct prefix *p,
  68                                     union sockunion *nexthop,
  69                                     struct interface *ifp)
  70 {
  71         struct route_node *rn;
  72         struct route_info *ri;
  73
  74         rn = nhrp_route_update_get(
  75                 p, (sockunion_family(nexthop) != AF_UNSPEC) || ifp);
  76         if (rn) {
  77                 ri = rn->info;
  78                 ri->via = *nexthop;
  79                 ri->ifp = ifp;
  80                 nhrp_route_update_put(rn);
  81         }
  82 }
  83
  84 void nhrp_route_update_nhrp(const struct prefix *p, struct interface *ifp)
  85 {
  86         struct route_node *rn;
  87         struct route_info *ri;
  88
  89         rn = nhrp_route_update_get(p, ifp != NULL);
  90         if (rn) {
  91                 ri = rn->info;
  92                 ri->nhrp_ifp = ifp;
  93                 nhrp_route_update_put(rn);
  94         }
  95 }
  96
  97 void nhrp_route_announce(int add, enum nhrp_cache_type type,
  98                          const struct prefix *p, struct interface *ifp,
  99                          const union sockunion *nexthop, uint32_t mtu)
 100 {
 101         struct zapi_route api;
 102         struct zapi_nexthop *api_nh;
 103
 104         if (zclient->sock < 0)
 105                 return;
 106
 107         memset(&api, 0, sizeof(api));
 108         api.type = ZEBRA_ROUTE_NHRP;
 109         api.safi = SAFI_UNICAST;
 110         api.vrf_id = VRF_DEFAULT;
 111         api.prefix = *p;
 112
 113         switch (type) {
 114         case NHRP_CACHE_NEGATIVE:
 115                 zapi_route_set_blackhole(&api, BLACKHOLE_REJECT);
 116                 ifp = NULL;
 117                 nexthop = NULL;
 118                 break;
 119         case NHRP_CACHE_DYNAMIC:
 120         case NHRP_CACHE_NHS:
 121         case NHRP_CACHE_STATIC:
 122                 /* Regular route, so these are announced
 123                  * to other routing daemons */
 124                 break;
 125         default:
 126                 SET_FLAG(api.flags, ZEBRA_FLAG_FIB_OVERRIDE);
 127                 break;
 128         }
 129         SET_FLAG(api.flags, ZEBRA_FLAG_ALLOW_RECURSION);
 130
 131         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 132         api.nexthop_num = 1;
 133         api_nh = &api.nexthops[0];
 134         api_nh->vrf_id = VRF_DEFAULT;
 135
 136         switch (api.prefix.family) {
 137         case AF_INET:
 138                 if (nexthop) {
 139                         api_nh->gate.ipv4 = nexthop->sin.sin_addr;
 140                         api_nh->type = NEXTHOP_TYPE_IPV4;
 141                 }
 142                 if (ifp) {
 143                         api_nh->ifindex = ifp->ifindex;
 144                         if (api_nh->type == NEXTHOP_TYPE_IPV4)
 145                                 api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 146                         else
 147                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 148                 }
 149                 break;
 150         case AF_INET6:
 151                 if (nexthop) {
 152                         api_nh->gate.ipv6 = nexthop->sin6.sin6_addr;
 153                         api_nh->type = NEXTHOP_TYPE_IPV6;
 154                 }
 155                 if (ifp) {
 156                         api_nh->ifindex = ifp->ifindex;
 157                         if (api_nh->type == NEXTHOP_TYPE_IPV6)
 158                                 api_nh->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 159                         else
 160                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 161                 }
 162                 break;
 163         }
 164         if (mtu) {
 165                 SET_FLAG(api.message, ZAPI_MESSAGE_MTU);
 166                 api.mtu = mtu;
 167         }
 168
 169         if (unlikely(debug_flags & NHRP_DEBUG_ROUTE)) {
 170                 char buf[2][PREFIX_STRLEN];
 171
 172                 prefix2str(&api.prefix, buf[0], sizeof(buf[0]));
 173                 zlog_debug(
 174                         "Zebra send: route %s %s nexthop %s metric %u"
 175                         " count %d dev %s",
 176                         add ? "add" : "del", buf[0],
 177                         nexthop ? inet_ntop(api.prefix.family, &api_nh->gate,
 178                                             buf[1], sizeof(buf[1]))
 179                                 : "<onlink>",
 180                         api.metric, api.nexthop_num, ifp ? ifp->name : "none");
 181         }
 182
 183         zclient_route_send(add ? ZEBRA_ROUTE_ADD : ZEBRA_ROUTE_DELETE, zclient,
 184                            &api);
 185 }
 186
 187 int nhrp_route_read(int cmd, struct zclient *zclient, zebra_size_t length,
 188                     vrf_id_t vrf_id)
 189 {
 190         struct zapi_route api;
 191         struct zapi_nexthop *api_nh;
 192         struct interface *ifp = NULL;
 193         union sockunion nexthop_addr;
 194         char buf[2][PREFIX_STRLEN];
 195         int added;
 196
 197         if (zapi_route_decode(zclient->ibuf, &api) < 0)
 198                 return -1;
 199
 200         /* we completely ignore srcdest routes for now. */
 201         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 202                 return 0;
 203
 204         sockunion_family(&nexthop_addr) = AF_UNSPEC;
 205         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
 206                 api_nh = &api.nexthops[0];
 207
 208                 nexthop_addr.sa.sa_family = api.prefix.family;
 209                 switch (nexthop_addr.sa.sa_family) {
 210                 case AF_INET:
 211                         nexthop_addr.sin.sin_addr = api_nh->gate.ipv4;
 212                         break;
 213                 case AF_INET6:
 214                         nexthop_addr.sin6.sin6_addr = api_nh->gate.ipv6;
 215                         break;
 216                 }
 217
 218                 if (api_nh->ifindex != IFINDEX_INTERNAL)
 219                         ifp = if_lookup_by_index(api_nh->ifindex, VRF_DEFAULT);
 220         }
 221
 222         added = (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
 223         debugf(NHRP_DEBUG_ROUTE, "if-route-%s: %s via %s dev %s",
 224                added ? "add" : "del",
 225                prefix2str(&api.prefix, buf[0], sizeof buf[0]),
 226                sockunion2str(&nexthop_addr, buf[1], sizeof buf[1]),
 227                ifp ? ifp->name : "(none)");
 228
 229         nhrp_route_update_zebra(&api.prefix, &nexthop_addr, ifp);
 230         nhrp_shortcut_prefix_change(&api.prefix, !added);
 231
 232         return 0;
 233 }
 234
 235 int nhrp_route_get_nexthop(const union sockunion *addr, struct prefix *p,
 236                            union sockunion *via, struct interface **ifp)
 237 {
 238         struct route_node *rn;
 239         struct route_info *ri;
 240         struct prefix lookup;
 241         afi_t afi = family2afi(sockunion_family(addr));
 242         char buf[PREFIX_STRLEN];
 243
 244         sockunion2hostprefix(addr, &lookup);
 245
 246         rn = route_node_match(zebra_rib[afi], &lookup);
 247         if (!rn)
 248                 return 0;
 249
 250         ri = rn->info;
 251         if (ri->nhrp_ifp) {
 252                 debugf(NHRP_DEBUG_ROUTE, "lookup %s: nhrp_if=%s",
 253                        prefix2str(&lookup, buf, sizeof buf),
 254                        ri->nhrp_ifp->name);
 255
 256                 if (via)
 257                         sockunion_family(via) = AF_UNSPEC;
 258                 if (ifp)
 259                         *ifp = ri->nhrp_ifp;
 260         } else {
 261                 debugf(NHRP_DEBUG_ROUTE, "lookup %s: zebra route dev %s",
 262                        prefix2str(&lookup, buf, sizeof buf),
 263                        ri->ifp ? ri->ifp->name : "(none)");
 264
 265                 if (via)
 266                         *via = ri->via;
 267                 if (ifp)
 268                         *ifp = ri->ifp;
 269         }
 270         if (p)
 271                 *p = rn->p;
 272         route_unlock_node(rn);
 273         return 1;
 274 }
 275
 276 enum nhrp_route_type nhrp_route_address(struct interface *in_ifp,
 277                                         union sockunion *addr, struct prefix *p,
 278                                         struct nhrp_peer **peer)
 279 {
 280         struct interface *ifp = in_ifp;
 281         struct nhrp_interface *nifp;
 282         struct nhrp_cache *c;
 283         union sockunion via[4];
 284         uint32_t network_id = 0;
 285         afi_t afi = family2afi(sockunion_family(addr));
 286         int i;
 287
 288         if (ifp) {
 289                 nifp = ifp->info;
 290                 network_id = nifp->afi[afi].network_id;
 291
 292                 c = nhrp_cache_get(ifp, addr, 0);
 293                 if (c && c->cur.type == NHRP_CACHE_LOCAL) {
 294                         if (p)
 295                                 memset(p, 0, sizeof(*p));
 296                         return NHRP_ROUTE_LOCAL;
 297                 }
 298         }
 299
 300         for (i = 0; i < 4; i++) {
 301                 if (!nhrp_route_get_nexthop(addr, p, &via[i], &ifp))
 302                         return NHRP_ROUTE_BLACKHOLE;
 303                 if (ifp) {
 304                         /* Departing from nbma network? */
 305                         nifp = ifp->info;
 306                         if (network_id
 307                             && network_id != nifp->afi[afi].network_id)
 308                                 return NHRP_ROUTE_OFF_NBMA;
 309                 }
 310                 if (sockunion_family(&via[i]) == AF_UNSPEC)
 311                         break;
 312                 /* Resolve via node, but return the prefix of first match */
 313                 addr = &via[i];
 314                 p = NULL;
 315         }
 316
 317         if (ifp) {
 318                 c = nhrp_cache_get(ifp, addr, 0);
 319                 if (c && c->cur.type >= NHRP_CACHE_DYNAMIC) {
 320                         if (p)
 321                                 memset(p, 0, sizeof(*p));
 322                         if (c->cur.type == NHRP_CACHE_LOCAL)
 323                                 return NHRP_ROUTE_LOCAL;
 324                         if (peer)
 325                                 *peer = nhrp_peer_ref(c->cur.peer);
 326                         return NHRP_ROUTE_NBMA_NEXTHOP;
 327                 }
 328         }
 329
 330         return NHRP_ROUTE_BLACKHOLE;
 331 }
 332
 333 static void nhrp_zebra_connected(struct zclient *zclient)
 334 {
 335         zclient_send_reg_requests(zclient, VRF_DEFAULT);
 336         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP,
 337                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 338         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP6,
 339                                 ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 340 }
 341
 342 void nhrp_zebra_init(void)
 343 {
 344         zebra_rib[AFI_IP] = route_table_init();
 345         zebra_rib[AFI_IP6] = route_table_init();
 346
 347         zclient = zclient_new(master, &zclient_options_default);
 348         zclient->zebra_connected = nhrp_zebra_connected;
 349         zclient->interface_add = nhrp_interface_add;
 350         zclient->interface_delete = nhrp_interface_delete;
 351         zclient->interface_up = nhrp_interface_up;
 352         zclient->interface_down = nhrp_interface_down;
 353         zclient->interface_address_add = nhrp_interface_address_add;
 354         zclient->interface_address_delete = nhrp_interface_address_delete;
 355         zclient->redistribute_route_add = nhrp_route_read;
 356         zclient->redistribute_route_del = nhrp_route_read;
 357
 358         zclient_init(zclient, ZEBRA_ROUTE_NHRP, 0, &nhrpd_privs);
 359 }
 360
 361 void nhrp_zebra_terminate(void)
 362 {
 363         zclient_stop(zclient);
 364         zclient_free(zclient);
 365         route_table_finish(zebra_rib[AFI_IP]);
 366         route_table_finish(zebra_rib[AFI_IP6]);
 367 }