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, int create)
  29 {
  30         struct route_node *rn;
  31         afi_t afi = family2afi(PREFIX_FAMILY(p));
  32
  33         if (!zebra_rib[afi])
  34                 return NULL;
  35
  36         if (create) {
  37                 rn = route_node_get(zebra_rib[afi], p);
  38                 if (!rn->info) {
  39                         rn->info = XCALLOC(MTYPE_NHRP_ROUTE, sizeof(struct route_info));
  40                         route_lock_node(rn);
  41                 }
  42                 return rn;
  43         } else {
  44                 return route_node_lookup(zebra_rib[afi], p);
  45         }
  46 }
  47
  48 static void nhrp_route_update_put(struct route_node *rn)
  49 {
  50         struct route_info *ri = rn->info;
  51
  52         if (!ri->ifp && !ri->nhrp_ifp && sockunion_family(&ri->via) == AF_UNSPEC) {
  53                 XFREE(MTYPE_NHRP_ROUTE, rn->info);
  54                 rn->info = NULL;
  55                 route_unlock_node(rn);
  56         }
  57         route_unlock_node(rn);
  58 }
  59
  60 static void nhrp_route_update_zebra(const struct prefix *p, union sockunion *nexthop, struct interface *ifp)
  61 {
  62         struct route_node *rn;
  63         struct route_info *ri;
  64
  65         rn = nhrp_route_update_get(p, (sockunion_family(nexthop) != AF_UNSPEC) || ifp);
  66         if (rn) {
  67                 ri = rn->info;
  68                 ri->via = *nexthop;
  69                 ri->ifp = ifp;
  70                 nhrp_route_update_put(rn);
  71         }
  72 }
  73
  74 void nhrp_route_update_nhrp(const struct prefix *p, struct interface *ifp)
  75 {
  76         struct route_node *rn;
  77         struct route_info *ri;
  78
  79         rn = nhrp_route_update_get(p, ifp != NULL);
  80         if (rn) {
  81                 ri = rn->info;
  82                 ri->nhrp_ifp = ifp;
  83                 nhrp_route_update_put(rn);
  84         }
  85 }
  86
  87 void nhrp_route_announce(int add, enum nhrp_cache_type type, const struct prefix *p, struct interface *ifp, const union sockunion *nexthop, uint32_t mtu)
  88 {
  89         struct zapi_route api;
  90         struct zapi_nexthop *api_nh;
  91
  92         if (zclient->sock < 0)
  93                 return;
  94
  95         memset(&api, 0, sizeof(api));
  96         api.type = ZEBRA_ROUTE_NHRP;
  97         api.safi = SAFI_UNICAST;
  98         api.prefix = *p;
  99
 100         switch (type) {
 101         case NHRP_CACHE_NEGATIVE:
 102                 SET_FLAG(api.flags, ZEBRA_FLAG_REJECT);
 103                 break;
 104         case NHRP_CACHE_DYNAMIC:
 105         case NHRP_CACHE_NHS:
 106         case NHRP_CACHE_STATIC:
 107                 /* Regular route, so these are announced
 108                  * to other routing daemons */
 109                 break;
 110         default:
 111                 SET_FLAG(api.flags, ZEBRA_FLAG_FIB_OVERRIDE);
 112                 break;
 113         }
 114         SET_FLAG(api.flags, ZEBRA_FLAG_INTERNAL);
 115
 116         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 117         api.nexthop_num = 1;
 118         api_nh = &api.nexthops[0];
 119
 120         switch (api.prefix.family) {
 121         case AF_INET:
 122                 if (nexthop) {
 123                         api_nh->gate.ipv4 = nexthop->sin.sin_addr;
 124                         api_nh->type = NEXTHOP_TYPE_IPV4;
 125                 }
 126                 if (ifp) {
 127                         api_nh->ifindex = ifp->ifindex;
 128                         if (api_nh->type == NEXTHOP_TYPE_IPV4)
 129                                 api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 130                         else
 131                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 132                 }
 133                 break;
 134         case AF_INET6:
 135                 if (nexthop) {
 136                         api_nh->gate.ipv6 = nexthop->sin6.sin6_addr;
 137                         api_nh->type = NEXTHOP_TYPE_IPV6;
 138                 }
 139                 if (ifp) {
 140                         api_nh->ifindex = ifp->ifindex;
 141                         if (api_nh->type == NEXTHOP_TYPE_IPV6)
 142                                 api_nh->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 143                         else
 144                                 api_nh->type = NEXTHOP_TYPE_IFINDEX;
 145                 }
 146                 break;
 147         }
 148         if (mtu) {
 149                 SET_FLAG(api.message, ZAPI_MESSAGE_MTU);
 150                 api.mtu = mtu;
 151         }
 152
 153         if (unlikely(debug_flags & NHRP_DEBUG_ROUTE)) {
 154                 char buf[2][PREFIX_STRLEN];
 155
 156                 prefix2str(&api.prefix, buf[0], sizeof(buf[0]));
 157                 zlog_debug("Zebra send: route %s %s nexthop %s metric %u"
 158                         " count %d dev %s",
 159                         add ? "add" : "del", buf[0],
 160                         nexthop ? inet_ntop(api.prefix.family, &api_nh->gate, buf[1], sizeof(buf[1])) : "<onlink>",
 161                         api.metric, api.nexthop_num, ifp->name);
 162         }
 163
 164         zclient_route_send(add ? ZEBRA_ROUTE_ADD : ZEBRA_ROUTE_DELETE, zclient,
 165                            &api);
 166 }
 167
 168 int nhrp_route_read(int cmd, struct zclient *zclient, zebra_size_t length, vrf_id_t vrf_id)
 169 {
 170         struct zapi_route api;
 171         struct zapi_nexthop *api_nh;
 172         struct interface *ifp = NULL;
 173         union sockunion nexthop_addr;
 174         char buf[2][PREFIX_STRLEN];
 175         int added;
 176
 177         if (zapi_route_decode(zclient->ibuf, &api) < 0)
 178                 return -1;
 179
 180         /* we completely ignore srcdest routes for now. */
 181         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 182                 return 0;
 183
 184         sockunion_family(&nexthop_addr) = AF_UNSPEC;
 185         if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
 186                 api_nh = &api.nexthops[0];
 187
 188                 nexthop_addr.sa.sa_family = api.prefix.family;
 189                 switch (nexthop_addr.sa.sa_family) {
 190                 case AF_INET:
 191                         nexthop_addr.sin.sin_addr = api_nh->gate.ipv4;
 192                         break;
 193                 case AF_INET6:
 194                         nexthop_addr.sin6.sin6_addr = api_nh->gate.ipv6;
 195                         break;
 196                 }
 197
 198                 if (api_nh->ifindex != IFINDEX_INTERNAL)
 199                         ifp = if_lookup_by_index(api_nh->ifindex, VRF_DEFAULT);
 200         }
 201
 202         added = (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
 203         debugf(NHRP_DEBUG_ROUTE, "if-route-%s: %s via %s dev %s",
 204                 added ? "add" : "del",
 205                 prefix2str(&api.prefix, buf[0], sizeof buf[0]),
 206                 sockunion2str(&nexthop_addr, buf[1], sizeof buf[1]),
 207                 ifp ? ifp->name : "(none)");
 208
 209         nhrp_route_update_zebra(&api.prefix, &nexthop_addr, ifp);
 210         nhrp_shortcut_prefix_change(&api.prefix, !added);
 211
 212         return 0;
 213 }
 214
 215 int nhrp_route_get_nexthop(const union sockunion *addr, struct prefix *p, union sockunion *via, struct interface **ifp)
 216 {
 217         struct route_node *rn;
 218         struct route_info *ri;
 219         struct prefix lookup;
 220         afi_t afi = family2afi(sockunion_family(addr));
 221         char buf[PREFIX_STRLEN];
 222
 223         sockunion2hostprefix(addr, &lookup);
 224
 225         rn = route_node_match(zebra_rib[afi], &lookup);
 226         if (!rn) return 0;
 227
 228         ri = rn->info;
 229         if (ri->nhrp_ifp) {
 230                 debugf(NHRP_DEBUG_ROUTE, "lookup %s: nhrp_if=%s",
 231                         prefix2str(&lookup, buf, sizeof buf),
 232                         ri->nhrp_ifp->name);
 233
 234                 if (via) sockunion_family(via) = AF_UNSPEC;
 235                 if (ifp) *ifp = ri->nhrp_ifp;
 236         } else {
 237                 debugf(NHRP_DEBUG_ROUTE, "lookup %s: zebra route dev %s",
 238                         prefix2str(&lookup, buf, sizeof buf),
 239                         ri->ifp ? ri->ifp->name : "(none)");
 240
 241                 if (via) *via = ri->via;
 242                 if (ifp) *ifp = ri->ifp;
 243         }
 244         if (p) *p = rn->p;
 245         route_unlock_node(rn);
 246         return 1;
 247 }
 248
 249 enum nhrp_route_type nhrp_route_address(struct interface *in_ifp, union sockunion *addr, struct prefix *p, struct nhrp_peer **peer)
 250 {
 251         struct interface *ifp = in_ifp;
 252         struct nhrp_interface *nifp;
 253         struct nhrp_cache *c;
 254         union sockunion via[4];
 255         uint32_t network_id = 0;
 256         afi_t afi = family2afi(sockunion_family(addr));
 257         int i;
 258
 259         if (ifp) {
 260                 nifp = ifp->info;
 261                 network_id = nifp->afi[afi].network_id;
 262
 263                 c = nhrp_cache_get(ifp, addr, 0);
 264                 if (c && c->cur.type == NHRP_CACHE_LOCAL) {
 265                         if (p) memset(p, 0, sizeof(*p));
 266                         return NHRP_ROUTE_LOCAL;
 267                 }
 268         }
 269
 270         for (i = 0; i < 4; i++) {
 271                 if (!nhrp_route_get_nexthop(addr, p, &via[i], &ifp))
 272                         return NHRP_ROUTE_BLACKHOLE;
 273                 if (ifp) {
 274                         /* Departing from nbma network? */
 275                         nifp = ifp->info;
 276                         if (network_id && network_id != nifp->afi[afi].network_id)
 277                                 return NHRP_ROUTE_OFF_NBMA;
 278                 }
 279                 if (sockunion_family(&via[i]) == AF_UNSPEC)
 280                         break;
 281                 /* Resolve via node, but return the prefix of first match */
 282                 addr = &via[i];
 283                 p = NULL;
 284         }
 285
 286         if (ifp) {
 287                 c = nhrp_cache_get(ifp, addr, 0);
 288                 if (c && c->cur.type >= NHRP_CACHE_DYNAMIC) {
 289                         if (p) memset(p, 0, sizeof(*p));
 290                         if (c->cur.type == NHRP_CACHE_LOCAL)
 291                                 return NHRP_ROUTE_LOCAL;
 292                         if (peer) *peer = nhrp_peer_ref(c->cur.peer);
 293                         return NHRP_ROUTE_NBMA_NEXTHOP;
 294                 }
 295         }
 296
 297         return NHRP_ROUTE_BLACKHOLE;
 298 }
 299
 300 static void
 301 nhrp_zebra_connected (struct zclient *zclient)
 302 {
 303         zclient_send_reg_requests(zclient, VRF_DEFAULT);
 304         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP,
 305             ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 306         zebra_redistribute_send(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP6,
 307             ZEBRA_ROUTE_ALL, 0, VRF_DEFAULT);
 308 }
 309
 310 void nhrp_zebra_init(void)
 311 {
 312         zebra_rib[AFI_IP] = route_table_init();
 313         zebra_rib[AFI_IP6] = route_table_init();
 314
 315         zclient = zclient_new(master);
 316         zclient->zebra_connected = nhrp_zebra_connected;
 317         zclient->interface_add = nhrp_interface_add;
 318         zclient->interface_delete = nhrp_interface_delete;
 319         zclient->interface_up = nhrp_interface_up;
 320         zclient->interface_down = nhrp_interface_down;
 321         zclient->interface_address_add = nhrp_interface_address_add;
 322         zclient->interface_address_delete = nhrp_interface_address_delete;
 323         zclient->redistribute_route_add = nhrp_route_read;
 324         zclient->redistribute_route_del = nhrp_route_read;
 325
 326         zclient_init(zclient, ZEBRA_ROUTE_NHRP, 0);
 327 }
 328
 329 void nhrp_zebra_terminate(void)
 330 {
 331         zclient_stop(zclient);
 332         zclient_free(zclient);
 333         route_table_finish(zebra_rib[AFI_IP]);
 334         route_table_finish(zebra_rib[AFI_IP6]);
 335 }