pimd/pim_rpf.c

   1 /*
   2  * PIM for Quagga
   3  * Copyright (C) 2008  Everton da Silva Marques
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; see the file COPYING; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <zebra.h>
  21
  22 #include "if.h"
  23
  24 #include "log.h"
  25 #include "prefix.h"
  26 #include "memory.h"
  27 #include "jhash.h"
  28
  29 #include "pimd.h"
  30 #include "pim_rpf.h"
  31 #include "pim_pim.h"
  32 #include "pim_str.h"
  33 #include "pim_iface.h"
  34 #include "pim_zlookup.h"
  35 #include "pim_ifchannel.h"
  36 #include "pim_time.h"
  37 #include "pim_nht.h"
  38 #include "pim_oil.h"
  39
  40 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
  41
  42 void pim_rpf_set_refresh_time(struct pim_instance *pim)
  43 {
  44         pim->last_route_change_time = pim_time_monotonic_usec();
  45         if (PIM_DEBUG_PIM_TRACE)
  46                 zlog_debug("%s: vrf(%s) New last route change time: %" PRId64,
  47                            __PRETTY_FUNCTION__, pim->vrf->name,
  48                            pim->last_route_change_time);
  49 }
  50
  51 bool pim_nexthop_lookup(struct pim_instance *pim, struct pim_nexthop *nexthop,
  52                         struct in_addr addr, int neighbor_needed)
  53 {
  54         struct pim_zlookup_nexthop nexthop_tab[MULTIPATH_NUM];
  55         struct pim_neighbor *nbr = NULL;
  56         int num_ifindex;
  57         struct interface *ifp = NULL;
  58         ifindex_t first_ifindex = 0;
  59         int found = 0;
  60         int i = 0;
  61
  62         /*
  63          * We should not attempt to lookup a
  64          * 255.255.255.255 address, since
  65          * it will never work
  66          */
  67         if (addr.s_addr == INADDR_NONE)
  68                 return false;
  69
  70         if ((nexthop->last_lookup.s_addr == addr.s_addr)
  71             && (nexthop->last_lookup_time > pim->last_route_change_time)) {
  72                 if (PIM_DEBUG_PIM_NHT) {
  73                         char addr_str[INET_ADDRSTRLEN];
  74                         pim_inet4_dump("<addr?>", addr, addr_str,
  75                                        sizeof(addr_str));
  76                         char nexthop_str[PREFIX_STRLEN];
  77                         pim_addr_dump("<nexthop?>", &nexthop->mrib_nexthop_addr,
  78                                       nexthop_str, sizeof(nexthop_str));
  79                         zlog_debug(
  80                                 "%s: Using last lookup for %s at %lld, %" PRId64 " addr %s",
  81                                 __PRETTY_FUNCTION__, addr_str,
  82                                 nexthop->last_lookup_time,
  83                                 pim->last_route_change_time, nexthop_str);
  84                 }
  85                 pim->nexthop_lookups_avoided++;
  86                 return true;
  87         } else {
  88                 if (PIM_DEBUG_PIM_NHT) {
  89                         char addr_str[INET_ADDRSTRLEN];
  90                         pim_inet4_dump("<addr?>", addr, addr_str,
  91                                        sizeof(addr_str));
  92                         zlog_debug(
  93                                 "%s: Looking up: %s, last lookup time: %lld, %" PRId64,
  94                                 __PRETTY_FUNCTION__, addr_str,
  95                                 nexthop->last_lookup_time,
  96                                 pim->last_route_change_time);
  97                 }
  98         }
  99
 100         memset(nexthop_tab, 0,
 101                sizeof(struct pim_zlookup_nexthop) * MULTIPATH_NUM);
 102         num_ifindex = zclient_lookup_nexthop(pim, nexthop_tab, MULTIPATH_NUM,
 103                                              addr, PIM_NEXTHOP_LOOKUP_MAX);
 104         if (num_ifindex < 1) {
 105                 char addr_str[INET_ADDRSTRLEN];
 106                 pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 107                 zlog_warn(
 108                         "%s %s: could not find nexthop ifindex for address %s",
 109                         __FILE__, __PRETTY_FUNCTION__, addr_str);
 110                 return false;
 111         }
 112
 113         while (!found && (i < num_ifindex)) {
 114                 first_ifindex = nexthop_tab[i].ifindex;
 115
 116                 ifp = if_lookup_by_index(first_ifindex, pim->vrf_id);
 117                 if (!ifp) {
 118                         if (PIM_DEBUG_ZEBRA) {
 119                                 char addr_str[INET_ADDRSTRLEN];
 120                                 pim_inet4_dump("<addr?>", addr, addr_str,
 121                                                sizeof(addr_str));
 122                                 zlog_debug(
 123                                         "%s %s: could not find interface for ifindex %d (address %s)",
 124                                         __FILE__, __PRETTY_FUNCTION__,
 125                                         first_ifindex, addr_str);
 126                         }
 127                         i++;
 128                         continue;
 129                 }
 130
 131                 if (!ifp->info) {
 132                         if (PIM_DEBUG_ZEBRA) {
 133                                 char addr_str[INET_ADDRSTRLEN];
 134                                 pim_inet4_dump("<addr?>", addr, addr_str,
 135                                                sizeof(addr_str));
 136                                 zlog_debug(
 137                                         "%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
 138                                         __PRETTY_FUNCTION__, ifp->name,
 139                                         first_ifindex, addr_str);
 140                         }
 141                         i++;
 142                 } else if (neighbor_needed
 143                            && !pim_if_connected_to_source(ifp, addr)) {
 144                         nbr = pim_neighbor_find(
 145                                 ifp, nexthop_tab[i].nexthop_addr.u.prefix4);
 146                         if (PIM_DEBUG_PIM_TRACE_DETAIL)
 147                                 zlog_debug("ifp name: %s, pim nbr: %p",
 148                                            ifp->name, nbr);
 149                         if (!nbr && !if_is_loopback(ifp))
 150                                 i++;
 151                         else
 152                                 found = 1;
 153                 } else
 154                         found = 1;
 155         }
 156
 157         if (found) {
 158                 if (PIM_DEBUG_ZEBRA) {
 159                         char nexthop_str[PREFIX_STRLEN];
 160                         char addr_str[INET_ADDRSTRLEN];
 161                         pim_addr_dump("<nexthop?>",
 162                                       &nexthop_tab[i].nexthop_addr, nexthop_str,
 163                                       sizeof(nexthop_str));
 164                         pim_inet4_dump("<addr?>", addr, addr_str,
 165                                        sizeof(addr_str));
 166                         zlog_debug(
 167                                 "%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
 168                                 __FILE__, __PRETTY_FUNCTION__, nexthop_str,
 169                                 addr_str, ifp->name, first_ifindex,
 170                                 nexthop_tab[i].route_metric,
 171                                 nexthop_tab[i].protocol_distance);
 172                 }
 173                 /* update nexthop data */
 174                 nexthop->interface = ifp;
 175                 nexthop->mrib_nexthop_addr = nexthop_tab[i].nexthop_addr;
 176                 nexthop->mrib_metric_preference =
 177                         nexthop_tab[i].protocol_distance;
 178                 nexthop->mrib_route_metric = nexthop_tab[i].route_metric;
 179                 nexthop->last_lookup = addr;
 180                 nexthop->last_lookup_time = pim_time_monotonic_usec();
 181                 nexthop->nbr = nbr;
 182                 return true;
 183         } else
 184                 return false;
 185 }
 186
 187 static int nexthop_mismatch(const struct pim_nexthop *nh1,
 188                             const struct pim_nexthop *nh2)
 189 {
 190         return (nh1->interface != nh2->interface)
 191                || (nh1->mrib_nexthop_addr.u.prefix4.s_addr
 192                    != nh2->mrib_nexthop_addr.u.prefix4.s_addr)
 193                || (nh1->mrib_metric_preference != nh2->mrib_metric_preference)
 194                || (nh1->mrib_route_metric != nh2->mrib_route_metric);
 195 }
 196
 197 enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
 198                                    struct pim_upstream *up, struct pim_rpf *old)
 199 {
 200         struct pim_rpf *rpf = &up->rpf;
 201         struct pim_rpf saved;
 202         struct prefix nht_p;
 203         struct prefix src, grp;
 204         bool neigh_needed = true;
 205
 206         if (PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(up->flags))
 207                 return PIM_RPF_OK;
 208
 209         if (up->upstream_addr.s_addr == INADDR_ANY) {
 210                 zlog_debug("%s: RP is not configured yet for %s",
 211                         __PRETTY_FUNCTION__, up->sg_str);
 212                 return PIM_RPF_OK;
 213         }
 214
 215         saved.source_nexthop = rpf->source_nexthop;
 216         saved.rpf_addr = rpf->rpf_addr;
 217
 218         nht_p.family = AF_INET;
 219         nht_p.prefixlen = IPV4_MAX_BITLEN;
 220         nht_p.u.prefix4.s_addr = up->upstream_addr.s_addr;
 221
 222         src.family = AF_INET;
 223         src.prefixlen = IPV4_MAX_BITLEN;
 224         src.u.prefix4 = up->upstream_addr; // RP or Src address
 225         grp.family = AF_INET;
 226         grp.prefixlen = IPV4_MAX_BITLEN;
 227         grp.u.prefix4 = up->sg.grp;
 228
 229         if ((up->sg.src.s_addr == INADDR_ANY && I_am_RP(pim, up->sg.grp)) ||
 230             PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
 231                 neigh_needed = false;
 232         pim_find_or_track_nexthop(pim, &nht_p, up, NULL, false, NULL);
 233         if (!pim_ecmp_nexthop_lookup(pim, &rpf->source_nexthop, &src, &grp,
 234                                      neigh_needed))
 235                 return PIM_RPF_FAILURE;
 236
 237         rpf->rpf_addr.family = AF_INET;
 238         rpf->rpf_addr.u.prefix4 = pim_rpf_find_rpf_addr(up);
 239         if (pim_rpf_addr_is_inaddr_any(rpf) && PIM_DEBUG_ZEBRA) {
 240                 /* RPF'(S,G) not found */
 241                 zlog_debug("%s %s: RPF'%s not found: won't send join upstream",
 242                            __FILE__, __PRETTY_FUNCTION__, up->sg_str);
 243                 /* warning only */
 244         }
 245
 246         /* detect change in pim_nexthop */
 247         if (nexthop_mismatch(&rpf->source_nexthop, &saved.source_nexthop)) {
 248
 249                 if (PIM_DEBUG_ZEBRA) {
 250                         char nhaddr_str[PREFIX_STRLEN];
 251                         pim_addr_dump("<addr?>",
 252                                       &rpf->source_nexthop.mrib_nexthop_addr,
 253                                       nhaddr_str, sizeof(nhaddr_str));
 254                         zlog_debug("%s %s: (S,G)=%s source nexthop now is: interface=%s address=%s pref=%d metric=%d",
 255                  __FILE__, __PRETTY_FUNCTION__,
 256                  up->sg_str,
 257                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
 258                  nhaddr_str,
 259                  rpf->source_nexthop.mrib_metric_preference,
 260                  rpf->source_nexthop.mrib_route_metric);
 261                 }
 262
 263                 pim_upstream_update_join_desired(pim, up);
 264                 pim_upstream_update_could_assert(up);
 265                 pim_upstream_update_my_assert_metric(up);
 266         }
 267
 268         /* detect change in RPF_interface(S) */
 269         if (saved.source_nexthop.interface != rpf->source_nexthop.interface) {
 270
 271                 if (PIM_DEBUG_ZEBRA) {
 272                         zlog_debug("%s %s: (S,G)=%s RPF_interface(S) changed from %s to %s",
 273                  __FILE__, __PRETTY_FUNCTION__,
 274                  up->sg_str,
 275                  saved.source_nexthop.interface ? saved.source_nexthop.interface->name : "<oldif?>",
 276                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
 277                         /* warning only */
 278                 }
 279
 280                 pim_upstream_rpf_interface_changed(
 281                         up, saved.source_nexthop.interface);
 282         }
 283
 284         /* detect change in RPF'(S,G) */
 285         if (saved.rpf_addr.u.prefix4.s_addr != rpf->rpf_addr.u.prefix4.s_addr
 286             || saved.source_nexthop
 287                                .interface != rpf->source_nexthop.interface) {
 288
 289                 /* return old rpf to caller ? */
 290                 if (old) {
 291                         old->source_nexthop = saved.source_nexthop;
 292                         old->rpf_addr = saved.rpf_addr;
 293                 }
 294                 return PIM_RPF_CHANGED;
 295         }
 296
 297         return PIM_RPF_OK;
 298 }
 299
 300 /*
 301  * In the case of RP deletion and RP unreachablity,
 302  * uninstall the mroute in the kernel and clear the
 303  * rpf information in the pim upstream and pim channel
 304  * oil data structure.
 305  */
 306 void pim_upstream_rpf_clear(struct pim_instance *pim,
 307                             struct pim_upstream *up)
 308 {
 309         if (up->rpf.source_nexthop.interface) {
 310                 if (up->channel_oil)
 311                         pim_channel_oil_change_iif(pim, up->channel_oil,
 312                                                    MAXVIFS,
 313                                                    __PRETTY_FUNCTION__);
 314
 315                 pim_upstream_switch(pim, up, PIM_UPSTREAM_NOTJOINED);
 316                 up->rpf.source_nexthop.interface = NULL;
 317                 up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4.s_addr =
 318                         PIM_NET_INADDR_ANY;
 319                 up->rpf.source_nexthop.mrib_metric_preference =
 320                         router->infinite_assert_metric.metric_preference;
 321                 up->rpf.source_nexthop.mrib_route_metric =
 322                         router->infinite_assert_metric.route_metric;
 323                 up->rpf.rpf_addr.u.prefix4.s_addr = PIM_NET_INADDR_ANY;
 324         }
 325 }
 326
 327 /*
 328   RFC 4601: 4.1.6.  State Summarization Macros
 329
 330      neighbor RPF'(S,G) {
 331          if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
 332               return AssertWinner(S, G, RPF_interface(S) )
 333          } else {
 334               return NBR( RPF_interface(S), MRIB.next_hop( S ) )
 335          }
 336      }
 337
 338   RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
 339   packets should be coming and to which joins should be sent on the RP
 340   tree and SPT, respectively.
 341 */
 342 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
 343 {
 344         struct pim_ifchannel *rpf_ch;
 345         struct pim_neighbor *neigh;
 346         struct in_addr rpf_addr;
 347
 348         if (!up->rpf.source_nexthop.interface) {
 349                 zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
 350                           __PRETTY_FUNCTION__, up->sg_str);
 351
 352                 rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 353                 return rpf_addr;
 354         }
 355
 356         rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface, &up->sg);
 357         if (rpf_ch) {
 358                 if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
 359                         return rpf_ch->ifassert_winner;
 360                 }
 361         }
 362
 363         /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
 364
 365         neigh = pim_if_find_neighbor(
 366                 up->rpf.source_nexthop.interface,
 367                 up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4);
 368         if (neigh)
 369                 rpf_addr = neigh->source_addr;
 370         else
 371                 rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 372
 373         return rpf_addr;
 374 }
 375
 376 int pim_rpf_addr_is_inaddr_none(struct pim_rpf *rpf)
 377 {
 378         switch (rpf->rpf_addr.family) {
 379         case AF_INET:
 380                 return rpf->rpf_addr.u.prefix4.s_addr == INADDR_NONE;
 381                 break;
 382         case AF_INET6:
 383                 zlog_warn("%s: v6 Unimplmeneted", __PRETTY_FUNCTION__);
 384                 return 1;
 385                 break;
 386         default:
 387                 return 0;
 388                 break;
 389         }
 390
 391         return 0;
 392 }
 393
 394 int pim_rpf_addr_is_inaddr_any(struct pim_rpf *rpf)
 395 {
 396         switch (rpf->rpf_addr.family) {
 397         case AF_INET:
 398                 return rpf->rpf_addr.u.prefix4.s_addr == INADDR_ANY;
 399                 break;
 400         case AF_INET6:
 401                 zlog_warn("%s: v6 Unimplmented", __PRETTY_FUNCTION__);
 402                 return 1;
 403                 break;
 404         default:
 405                 return 0;
 406                 break;
 407         }
 408
 409         return 0;
 410 }
 411
 412 int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2)
 413 {
 414         if (rpf1->source_nexthop.interface == rpf2->source_nexthop.interface)
 415                 return 1;
 416
 417         return 0;
 418 }
 419
 420 unsigned int pim_rpf_hash_key(const void *arg)
 421 {
 422         const struct pim_nexthop_cache *r = arg;
 423
 424         return jhash_1word(r->rpf.rpf_addr.u.prefix4.s_addr, 0);
 425 }
 426
 427 bool pim_rpf_equal(const void *arg1, const void *arg2)
 428 {
 429         const struct pim_nexthop_cache *r1 =
 430                 (const struct pim_nexthop_cache *)arg1;
 431         const struct pim_nexthop_cache *r2 =
 432                 (const struct pim_nexthop_cache *)arg2;
 433
 434         return prefix_same(&r1->rpf.rpf_addr, &r2->rpf.rpf_addr);
 435 }