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 long long last_route_change_time = -1;
  41 long long nexthop_lookups_avoided = 0;
  42
  43 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
  44
  45 void pim_rpf_set_refresh_time(void)
  46 {
  47         last_route_change_time = pim_time_monotonic_usec();
  48         if (PIM_DEBUG_TRACE)
  49                 zlog_debug("%s: New last route change time: %lld",
  50                            __PRETTY_FUNCTION__, last_route_change_time);
  51 }
  52
  53 int pim_nexthop_lookup(struct pim_instance *pim, struct pim_nexthop *nexthop,
  54                        struct in_addr addr, int neighbor_needed)
  55 {
  56         struct pim_zlookup_nexthop nexthop_tab[MULTIPATH_NUM];
  57         struct pim_neighbor *nbr = NULL;
  58         int num_ifindex;
  59         struct interface *ifp = NULL;
  60         ifindex_t first_ifindex = 0;
  61         int found = 0;
  62         int i = 0;
  63
  64         if ((nexthop->last_lookup.s_addr == addr.s_addr)
  65             && (nexthop->last_lookup_time > last_route_change_time)) {
  66                 if (PIM_DEBUG_TRACE) {
  67                         char addr_str[INET_ADDRSTRLEN];
  68                         pim_inet4_dump("<addr?>", addr, addr_str,
  69                                        sizeof(addr_str));
  70                         char nexthop_str[PREFIX_STRLEN];
  71                         pim_addr_dump("<nexthop?>", &nexthop->mrib_nexthop_addr,
  72                                       nexthop_str, sizeof(nexthop_str));
  73                         zlog_debug(
  74                                 "%s: Using last lookup for %s at %lld, %lld addr%s",
  75                                 __PRETTY_FUNCTION__, addr_str,
  76                                 nexthop->last_lookup_time,
  77                                 last_route_change_time, nexthop_str);
  78                 }
  79                 nexthop_lookups_avoided++;
  80                 return 0;
  81         } else {
  82                 if (PIM_DEBUG_TRACE) {
  83                         char addr_str[INET_ADDRSTRLEN];
  84                         pim_inet4_dump("<addr?>", addr, addr_str,
  85                                        sizeof(addr_str));
  86                         zlog_debug(
  87                                 "%s: Looking up: %s, last lookup time: %lld, %lld",
  88                                 __PRETTY_FUNCTION__, addr_str,
  89                                 nexthop->last_lookup_time,
  90                                 last_route_change_time);
  91                 }
  92         }
  93
  94         memset(nexthop_tab, 0,
  95                sizeof(struct pim_zlookup_nexthop) * MULTIPATH_NUM);
  96         num_ifindex = zclient_lookup_nexthop(pim, nexthop_tab, MULTIPATH_NUM,
  97                                              addr, PIM_NEXTHOP_LOOKUP_MAX);
  98         if (num_ifindex < 1) {
  99                 char addr_str[INET_ADDRSTRLEN];
 100                 pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 101                 zlog_warn(
 102                         "%s %s: could not find nexthop ifindex for address %s",
 103                         __FILE__, __PRETTY_FUNCTION__, addr_str);
 104                 return -1;
 105         }
 106
 107         while (!found && (i < num_ifindex)) {
 108                 first_ifindex = nexthop_tab[i].ifindex;
 109
 110                 ifp = if_lookup_by_index(first_ifindex, pim->vrf_id);
 111                 if (!ifp) {
 112                         if (PIM_DEBUG_ZEBRA) {
 113                                 char addr_str[INET_ADDRSTRLEN];
 114                                 pim_inet4_dump("<addr?>", addr, addr_str,
 115                                                sizeof(addr_str));
 116                                 zlog_debug(
 117                                         "%s %s: could not find interface for ifindex %d (address %s)",
 118                                         __FILE__, __PRETTY_FUNCTION__,
 119                                         first_ifindex, addr_str);
 120                         }
 121                         i++;
 122                         continue;
 123                 }
 124
 125                 if (!ifp->info) {
 126                         if (PIM_DEBUG_ZEBRA) {
 127                                 char addr_str[INET_ADDRSTRLEN];
 128                                 pim_inet4_dump("<addr?>", addr, addr_str,
 129                                                sizeof(addr_str));
 130                                 zlog_debug(
 131                                         "%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
 132                                         __PRETTY_FUNCTION__, ifp->name,
 133                                         first_ifindex, addr_str);
 134                         }
 135                         i++;
 136                 } else if (neighbor_needed
 137                            && !pim_if_connected_to_source(ifp, addr)) {
 138                         nbr = pim_neighbor_find(
 139                                 ifp, nexthop_tab[i].nexthop_addr.u.prefix4);
 140                         if (PIM_DEBUG_PIM_TRACE_DETAIL)
 141                                 zlog_debug("ifp name: %s, pim nbr: %p",
 142                                            ifp->name, nbr);
 143                         if (!nbr && !if_is_loopback(ifp))
 144                                 i++;
 145                         else
 146                                 found = 1;
 147                 } else
 148                         found = 1;
 149         }
 150
 151         if (found) {
 152                 if (PIM_DEBUG_ZEBRA) {
 153                         char nexthop_str[PREFIX_STRLEN];
 154                         char addr_str[INET_ADDRSTRLEN];
 155                         pim_addr_dump("<nexthop?>",
 156                                       &nexthop_tab[i].nexthop_addr, nexthop_str,
 157                                       sizeof(nexthop_str));
 158                         pim_inet4_dump("<addr?>", addr, addr_str,
 159                                        sizeof(addr_str));
 160                         zlog_debug(
 161                                 "%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
 162                                 __FILE__, __PRETTY_FUNCTION__, nexthop_str,
 163                                 addr_str, ifp->name, first_ifindex,
 164                                 nexthop_tab[i].route_metric,
 165                                 nexthop_tab[i].protocol_distance);
 166                 }
 167                 /* update nextop data */
 168                 nexthop->interface = ifp;
 169                 nexthop->mrib_nexthop_addr = nexthop_tab[i].nexthop_addr;
 170                 nexthop->mrib_metric_preference =
 171                         nexthop_tab[i].protocol_distance;
 172                 nexthop->mrib_route_metric = nexthop_tab[i].route_metric;
 173                 nexthop->last_lookup = addr;
 174                 nexthop->last_lookup_time = pim_time_monotonic_usec();
 175                 nexthop->nbr = nbr;
 176                 return 0;
 177         } else
 178                 return -1;
 179 }
 180
 181 static int nexthop_mismatch(const struct pim_nexthop *nh1,
 182                             const struct pim_nexthop *nh2)
 183 {
 184         return (nh1->interface != nh2->interface)
 185                || (nh1->mrib_nexthop_addr.u.prefix4.s_addr
 186                    != nh2->mrib_nexthop_addr.u.prefix4.s_addr)
 187                || (nh1->mrib_metric_preference != nh2->mrib_metric_preference)
 188                || (nh1->mrib_route_metric != nh2->mrib_route_metric);
 189 }
 190
 191 enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
 192                                    struct pim_upstream *up, struct pim_rpf *old,
 193                                    uint8_t is_new)
 194 {
 195         struct pim_rpf *rpf = &up->rpf;
 196         struct pim_rpf saved;
 197         struct prefix nht_p;
 198         struct pim_nexthop_cache pnc;
 199         struct prefix src, grp;
 200
 201         saved.source_nexthop = rpf->source_nexthop;
 202         saved.rpf_addr = rpf->rpf_addr;
 203
 204         if (is_new && PIM_DEBUG_ZEBRA) {
 205                 char source_str[INET_ADDRSTRLEN];
 206                 pim_inet4_dump("<source?>", up->upstream_addr, source_str,
 207                                sizeof(source_str));
 208                 zlog_debug("%s: NHT Register upstream %s addr %s with Zebra.",
 209                            __PRETTY_FUNCTION__, up->sg_str, source_str);
 210         }
 211         /* Register addr with Zebra NHT */
 212         nht_p.family = AF_INET;
 213         nht_p.prefixlen = IPV4_MAX_BITLEN;
 214         nht_p.u.prefix4.s_addr = up->upstream_addr.s_addr;
 215
 216         src.family = AF_INET;
 217         src.prefixlen = IPV4_MAX_BITLEN;
 218         src.u.prefix4 = up->upstream_addr; // RP or Src address
 219         grp.family = AF_INET;
 220         grp.prefixlen = IPV4_MAX_BITLEN;
 221         grp.u.prefix4 = up->sg.grp;
 222         memset(&pnc, 0, sizeof(struct pim_nexthop_cache));
 223         if (pim_find_or_track_nexthop(pim, &nht_p, up, NULL, &pnc)) {
 224                 if (pnc.nexthop_num) {
 225                         if (!pim_ecmp_nexthop_search(
 226                                     pim, &pnc, &up->rpf.source_nexthop, &src,
 227                                     &grp,
 228                                     !PIM_UPSTREAM_FLAG_TEST_FHR(up->flags)
 229                                             && !PIM_UPSTREAM_FLAG_TEST_SRC_IGMP(
 230                                                        up->flags)))
 231                                 return PIM_RPF_FAILURE;
 232                 }
 233         } else {
 234                 if (!pim_ecmp_nexthop_lookup(
 235                             pim, &rpf->source_nexthop, up->upstream_addr, &src,
 236                             &grp, !PIM_UPSTREAM_FLAG_TEST_FHR(up->flags)
 237                                           && !PIM_UPSTREAM_FLAG_TEST_SRC_IGMP(
 238                                                      up->flags)))
 239                         return PIM_RPF_FAILURE;
 240         }
 241
 242         rpf->rpf_addr.family = AF_INET;
 243         rpf->rpf_addr.u.prefix4 = pim_rpf_find_rpf_addr(up);
 244         if (pim_rpf_addr_is_inaddr_any(rpf) && PIM_DEBUG_ZEBRA) {
 245                 /* RPF'(S,G) not found */
 246                 zlog_debug("%s %s: RPF'%s not found: won't send join upstream",
 247                            __FILE__, __PRETTY_FUNCTION__, up->sg_str);
 248                 /* warning only */
 249         }
 250
 251         /* detect change in pim_nexthop */
 252         if (nexthop_mismatch(&rpf->source_nexthop, &saved.source_nexthop)) {
 253
 254                 if (PIM_DEBUG_ZEBRA) {
 255                         char nhaddr_str[PREFIX_STRLEN];
 256                         pim_addr_dump("<addr?>",
 257                                       &rpf->source_nexthop.mrib_nexthop_addr,
 258                                       nhaddr_str, sizeof(nhaddr_str));
 259                         zlog_debug("%s %s: (S,G)=%s source nexthop now is: interface=%s address=%s pref=%d metric=%d",
 260                  __FILE__, __PRETTY_FUNCTION__,
 261                  up->sg_str,
 262                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
 263                  nhaddr_str,
 264                  rpf->source_nexthop.mrib_metric_preference,
 265                  rpf->source_nexthop.mrib_route_metric);
 266                 }
 267
 268                 pim_upstream_update_join_desired(pim, up);
 269                 pim_upstream_update_could_assert(up);
 270                 pim_upstream_update_my_assert_metric(up);
 271         }
 272
 273         /* detect change in RPF_interface(S) */
 274         if (saved.source_nexthop.interface != rpf->source_nexthop.interface) {
 275
 276                 if (PIM_DEBUG_ZEBRA) {
 277                         zlog_debug("%s %s: (S,G)=%s RPF_interface(S) changed from %s to %s",
 278                  __FILE__, __PRETTY_FUNCTION__,
 279                  up->sg_str,
 280                  saved.source_nexthop.interface ? saved.source_nexthop.interface->name : "<oldif?>",
 281                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
 282                         /* warning only */
 283                 }
 284
 285                 pim_upstream_rpf_interface_changed(
 286                         up, saved.source_nexthop.interface);
 287         }
 288
 289         /* detect change in RPF'(S,G) */
 290         if (saved.rpf_addr.u.prefix4.s_addr != rpf->rpf_addr.u.prefix4.s_addr
 291             || saved.source_nexthop
 292                                .interface != rpf->source_nexthop.interface) {
 293
 294                 /* return old rpf to caller ? */
 295                 if (old) {
 296                         old->source_nexthop = saved.source_nexthop;
 297                         old->rpf_addr = saved.rpf_addr;
 298                 }
 299                 return PIM_RPF_CHANGED;
 300         }
 301
 302         return PIM_RPF_OK;
 303 }
 304
 305 /*
 306   RFC 4601: 4.1.6.  State Summarization Macros
 307
 308      neighbor RPF'(S,G) {
 309          if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
 310               return AssertWinner(S, G, RPF_interface(S) )
 311          } else {
 312               return NBR( RPF_interface(S), MRIB.next_hop( S ) )
 313          }
 314      }
 315
 316   RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
 317   packets should be coming and to which joins should be sent on the RP
 318   tree and SPT, respectively.
 319 */
 320 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
 321 {
 322         struct pim_ifchannel *rpf_ch;
 323         struct pim_neighbor *neigh;
 324         struct in_addr rpf_addr;
 325
 326         if (!up->rpf.source_nexthop.interface) {
 327                 zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
 328                           __PRETTY_FUNCTION__, up->sg_str);
 329
 330                 rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 331                 return rpf_addr;
 332         }
 333
 334         rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface, &up->sg);
 335         if (rpf_ch) {
 336                 if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
 337                         return rpf_ch->ifassert_winner;
 338                 }
 339         }
 340
 341         /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
 342
 343         neigh = pim_if_find_neighbor(
 344                 up->rpf.source_nexthop.interface,
 345                 up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4);
 346         if (neigh)
 347                 rpf_addr = neigh->source_addr;
 348         else
 349                 rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 350
 351         return rpf_addr;
 352 }
 353
 354 int pim_rpf_addr_is_inaddr_none(struct pim_rpf *rpf)
 355 {
 356         switch (rpf->rpf_addr.family) {
 357         case AF_INET:
 358                 return rpf->rpf_addr.u.prefix4.s_addr == INADDR_NONE;
 359                 break;
 360         case AF_INET6:
 361                 zlog_warn("%s: v6 Unimplmeneted", __PRETTY_FUNCTION__);
 362                 return 1;
 363                 break;
 364         default:
 365                 return 0;
 366                 break;
 367         }
 368
 369         return 0;
 370 }
 371
 372 int pim_rpf_addr_is_inaddr_any(struct pim_rpf *rpf)
 373 {
 374         switch (rpf->rpf_addr.family) {
 375         case AF_INET:
 376                 return rpf->rpf_addr.u.prefix4.s_addr == INADDR_ANY;
 377                 break;
 378         case AF_INET6:
 379                 zlog_warn("%s: v6 Unimplmented", __PRETTY_FUNCTION__);
 380                 return 1;
 381                 break;
 382         default:
 383                 return 0;
 384                 break;
 385         }
 386
 387         return 0;
 388 }
 389
 390 int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2)
 391 {
 392         if (rpf1->source_nexthop.interface == rpf2->source_nexthop.interface)
 393                 return 1;
 394
 395         return 0;
 396 }
 397
 398 unsigned int pim_rpf_hash_key(void *arg)
 399 {
 400         struct pim_nexthop_cache *r = (struct pim_nexthop_cache *)arg;
 401
 402         return jhash_1word(r->rpf.rpf_addr.u.prefix4.s_addr, 0);
 403 }
 404
 405 int pim_rpf_equal(const void *arg1, const void *arg2)
 406 {
 407         const struct pim_nexthop_cache *r1 =
 408                 (const struct pim_nexthop_cache *)arg1;
 409         const struct pim_nexthop_cache *r2 =
 410                 (const struct pim_nexthop_cache *)arg2;
 411
 412         return prefix_same(&r1->rpf.rpf_addr, &r2->rpf.rpf_addr);
 413 }