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
  16   along with this program; see the file COPYING; if not, write to the
  17   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18   MA 02110-1301 USA
  19 */
  20
  21 #include <zebra.h>
  22
  23 #include "if.h"
  24
  25 #include "log.h"
  26 #include "prefix.h"
  27 #include "memory.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
  38 static long long last_route_change_time = -1;
  39 long long nexthop_lookups_avoided = 0;
  40
  41 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
  42
  43 void
  44 pim_rpf_set_refresh_time (void)
  45 {
  46   last_route_change_time = pim_time_monotonic_usec();
  47   if (PIM_DEBUG_TRACE)
  48     zlog_debug ("%s: New last route change time: %lld",
  49                 __PRETTY_FUNCTION__, last_route_change_time);
  50 }
  51
  52 int pim_nexthop_lookup(struct pim_nexthop *nexthop, 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   if ((nexthop->last_lookup.s_addr == addr.s_addr) &&
  63       (nexthop->last_lookup_time > last_route_change_time))
  64     {
  65       if (PIM_DEBUG_TRACE)
  66         {
  67           char addr_str[INET_ADDRSTRLEN];
  68           pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
  69           zlog_debug ("%s: Using last lookup for %s at %lld, %lld",
  70                       __PRETTY_FUNCTION__,
  71                       addr_str,
  72                       nexthop->last_lookup_time,
  73                       last_route_change_time);
  74         }
  75       nexthop_lookups_avoided++;
  76       return 0;
  77     }
  78   else
  79     {
  80       if (PIM_DEBUG_TRACE)
  81         {
  82           char addr_str[INET_ADDRSTRLEN];
  83           pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
  84           zlog_debug ("%s: Looking up: %s, last lookup time: %lld, %lld",
  85                       __PRETTY_FUNCTION__,
  86                       addr_str,
  87                       nexthop->last_lookup_time,
  88                       last_route_change_time);
  89         }
  90     }
  91
  92   memset (nexthop_tab, 0, sizeof (struct pim_zlookup_nexthop) * MULTIPATH_NUM);
  93   num_ifindex = zclient_lookup_nexthop(nexthop_tab,
  94                                        MULTIPATH_NUM,
  95                                        addr, PIM_NEXTHOP_LOOKUP_MAX);
  96   if (num_ifindex < 1) {
  97     char addr_str[INET_ADDRSTRLEN];
  98     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
  99     zlog_warn("%s %s: could not find nexthop ifindex for address %s",
 100               __FILE__, __PRETTY_FUNCTION__,
 101               addr_str);
 102     return -1;
 103   }
 104
 105   while (!found && (i < num_ifindex))
 106     {
 107       first_ifindex = nexthop_tab[i].ifindex;
 108
 109       ifp = if_lookup_by_index(first_ifindex);
 110       if (!ifp)
 111         {
 112           if (PIM_DEBUG_ZEBRA)
 113             {
 114               char addr_str[INET_ADDRSTRLEN];
 115               pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 116               zlog_debug("%s %s: could not find interface for ifindex %d (address %s)",
 117                          __FILE__, __PRETTY_FUNCTION__,
 118                          first_ifindex, addr_str);
 119             }
 120           i++;
 121           continue;
 122         }
 123
 124       if (!ifp->info)
 125         {
 126           if (PIM_DEBUG_ZEBRA)
 127             {
 128               char addr_str[INET_ADDRSTRLEN];
 129               pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 130               zlog_debug("%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
 131                          __PRETTY_FUNCTION__,
 132                          ifp->name, first_ifindex, addr_str);
 133             }
 134           i++;
 135         }
 136       else if (neighbor_needed && !pim_if_connected_to_source (ifp, addr))
 137         {
 138           nbr = pim_neighbor_find (ifp, nexthop_tab[i].nexthop_addr.u.prefix4);
 139           if (PIM_DEBUG_PIM_TRACE_DETAIL)
 140             zlog_debug ("ifp name: %s, pim nbr: %p", ifp->name, nbr);
 141           if (!nbr && !if_is_loopback (ifp))
 142             i++;
 143           else
 144             found = 1;
 145         }
 146       else
 147         found = 1;
 148     }
 149
 150   if (found)
 151     {
 152       if (PIM_DEBUG_ZEBRA) {
 153         char nexthop_str[PREFIX_STRLEN];
 154         char addr_str[INET_ADDRSTRLEN];
 155         pim_addr_dump("<nexthop?>", &nexthop_tab[i].nexthop_addr, nexthop_str, sizeof(nexthop_str));
 156         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 157         zlog_debug("%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
 158                    __FILE__, __PRETTY_FUNCTION__,
 159                    nexthop_str, addr_str,
 160                    ifp->name, first_ifindex,
 161                    nexthop_tab[i].route_metric,
 162                    nexthop_tab[i].protocol_distance);
 163       }
 164       /* update nextop data */
 165       nexthop->interface                = ifp;
 166       nexthop->mrib_nexthop_addr        = nexthop_tab[i].nexthop_addr;
 167       nexthop->mrib_metric_preference   = nexthop_tab[i].protocol_distance;
 168       nexthop->mrib_route_metric        = nexthop_tab[i].route_metric;
 169       nexthop->last_lookup              = addr;
 170       nexthop->last_lookup_time         = pim_time_monotonic_usec();
 171       nexthop->nbr                      = nbr;
 172       return 0;
 173     }
 174   else
 175     return -1;
 176 }
 177
 178 static int nexthop_mismatch(const struct pim_nexthop *nh1,
 179                             const struct pim_nexthop *nh2)
 180 {
 181   return (nh1->interface != nh2->interface)                          ||
 182     (nh1->mrib_nexthop_addr.u.prefix4.s_addr != nh2->mrib_nexthop_addr.u.prefix4.s_addr) ||
 183     (nh1->mrib_metric_preference != nh2->mrib_metric_preference)     ||
 184     (nh1->mrib_route_metric != nh2->mrib_route_metric);
 185 }
 186
 187 enum pim_rpf_result pim_rpf_update(struct pim_upstream *up, struct pim_rpf *old)
 188 {
 189   struct pim_rpf     *rpf = &up->rpf;
 190   struct pim_rpf     saved;
 191
 192   saved.source_nexthop = rpf->source_nexthop;
 193   saved.rpf_addr = rpf->rpf_addr;
 194
 195   if (pim_nexthop_lookup(&rpf->source_nexthop,
 196                          up->upstream_addr,
 197                          !PIM_UPSTREAM_FLAG_TEST_FHR (up->flags) &&
 198                          !PIM_UPSTREAM_FLAG_TEST_SRC_IGMP (up->flags))) {
 199     return PIM_RPF_FAILURE;
 200   }
 201
 202   rpf->rpf_addr.family = AF_INET;
 203   rpf->rpf_addr.u.prefix4 = pim_rpf_find_rpf_addr(up);
 204   if (pim_rpf_addr_is_inaddr_any(rpf) && PIM_DEBUG_ZEBRA) {
 205     /* RPF'(S,G) not found */
 206     zlog_debug("%s %s: RPF'%s not found: won't send join upstream",
 207                __FILE__, __PRETTY_FUNCTION__,
 208                up->sg_str);
 209     /* warning only */
 210   }
 211
 212   /* detect change in pim_nexthop */
 213   if (nexthop_mismatch(&rpf->source_nexthop, &saved.source_nexthop)) {
 214
 215     if (PIM_DEBUG_ZEBRA) {
 216       char nhaddr_str[PREFIX_STRLEN];
 217       pim_addr_dump("<addr?>", &rpf->source_nexthop.mrib_nexthop_addr, nhaddr_str, sizeof(nhaddr_str));
 218       zlog_debug("%s %s: (S,G)=%s source nexthop now is: interface=%s address=%s pref=%d metric=%d",
 219                  __FILE__, __PRETTY_FUNCTION__,
 220                  up->sg_str,
 221                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
 222                  nhaddr_str,
 223                  rpf->source_nexthop.mrib_metric_preference,
 224                  rpf->source_nexthop.mrib_route_metric);
 225     }
 226
 227     pim_upstream_update_join_desired(up);
 228     pim_upstream_update_could_assert(up);
 229     pim_upstream_update_my_assert_metric(up);
 230   }
 231
 232   /* detect change in RPF_interface(S) */
 233   if (saved.source_nexthop.interface != rpf->source_nexthop.interface) {
 234
 235     if (PIM_DEBUG_ZEBRA) {
 236       zlog_debug("%s %s: (S,G)=%s RPF_interface(S) changed from %s to %s",
 237                  __FILE__, __PRETTY_FUNCTION__,
 238                  up->sg_str,
 239                  saved.source_nexthop.interface ? saved.source_nexthop.interface->name : "<oldif?>",
 240                  rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
 241       /* warning only */
 242     }
 243
 244     pim_upstream_rpf_interface_changed(up, saved.source_nexthop.interface);
 245   }
 246
 247   /* detect change in RPF'(S,G) */
 248   if (saved.rpf_addr.u.prefix4.s_addr != rpf->rpf_addr.u.prefix4.s_addr) {
 249
 250     /* return old rpf to caller ? */
 251     if (old)
 252       {
 253         old->source_nexthop = saved.source_nexthop;
 254         old->rpf_addr = saved.rpf_addr;
 255       }
 256     return PIM_RPF_CHANGED;
 257   }
 258
 259   return PIM_RPF_OK;
 260 }
 261
 262 /*
 263   RFC 4601: 4.1.6.  State Summarization Macros
 264
 265      neighbor RPF'(S,G) {
 266          if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
 267               return AssertWinner(S, G, RPF_interface(S) )
 268          } else {
 269               return NBR( RPF_interface(S), MRIB.next_hop( S ) )
 270          }
 271      }
 272
 273   RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
 274   packets should be coming and to which joins should be sent on the RP
 275   tree and SPT, respectively.
 276 */
 277 static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
 278 {
 279   struct pim_ifchannel *rpf_ch;
 280   struct pim_neighbor *neigh;
 281   struct in_addr rpf_addr;
 282
 283   if (!up->rpf.source_nexthop.interface) {
 284     zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
 285               __PRETTY_FUNCTION__,
 286               up->sg_str);
 287
 288     rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 289     return rpf_addr;
 290   }
 291
 292   rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface,
 293                               &up->sg);
 294   if (rpf_ch) {
 295     if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
 296       return rpf_ch->ifassert_winner;
 297     }
 298   }
 299
 300   /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
 301
 302   neigh = pim_if_find_neighbor(up->rpf.source_nexthop.interface,
 303                                up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4);
 304   if (neigh)
 305     rpf_addr = neigh->source_addr;
 306   else
 307     rpf_addr.s_addr = PIM_NET_INADDR_ANY;
 308
 309   return rpf_addr;
 310 }
 311
 312 int
 313 pim_rpf_addr_is_inaddr_none (struct pim_rpf *rpf)
 314 {
 315   switch (rpf->rpf_addr.family)
 316     {
 317     case AF_INET:
 318       return rpf->rpf_addr.u.prefix4.s_addr == INADDR_NONE;
 319       break;
 320     case AF_INET6:
 321       zlog_warn ("%s: v6 Unimplmeneted", __PRETTY_FUNCTION__);
 322       return 1;
 323       break;
 324     default:
 325       return 0;
 326       break;
 327     }
 328
 329   return 0;
 330 }
 331
 332 int
 333 pim_rpf_addr_is_inaddr_any (struct pim_rpf *rpf)
 334 {
 335   switch (rpf->rpf_addr.family)
 336     {
 337     case AF_INET:
 338       return rpf->rpf_addr.u.prefix4.s_addr == INADDR_ANY;
 339       break;
 340     case AF_INET6:
 341       zlog_warn ("%s: v6 Unimplmented", __PRETTY_FUNCTION__);
 342       return 1;
 343       break;
 344     default:
 345       return 0;
 346       break;
 347     }
 348
 349   return 0;
 350 }
 351
 352 int
 353 pim_rpf_is_same (struct pim_rpf *rpf1, struct pim_rpf *rpf2)
 354 {
 355   if (rpf1->source_nexthop.interface == rpf2->source_nexthop.interface)
 356     return 1;
 357
 358   return 0;
 359 }