Annotation of embedaddon/quagga/pimd/pim_rpf.c, revision 1.1.1.1

1.1       misho       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:   $QuaggaId: $Format:%an, %ai, %h$ $
                     21: */
                     22: 
                     23: #include <zebra.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: 
                     37: static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
                     38: 
                     39: int pim_nexthop_lookup(struct pim_nexthop *nexthop,
                     40:                       struct in_addr addr)
                     41: {
                     42:   struct pim_zlookup_nexthop nexthop_tab[PIM_NEXTHOP_IFINDEX_TAB_SIZE];
                     43:   int num_ifindex;
                     44:   struct interface *ifp;
                     45:   int first_ifindex;
                     46: 
                     47:   num_ifindex = zclient_lookup_nexthop(qpim_zclient_lookup, nexthop_tab,
                     48:                                       PIM_NEXTHOP_IFINDEX_TAB_SIZE,
                     49:                                       addr, PIM_NEXTHOP_LOOKUP_MAX);
                     50:   if (num_ifindex < 1) {
                     51:     char addr_str[100];
                     52:     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
                     53:     zlog_warn("%s %s: could not find nexthop ifindex for address %s",
                     54:              __FILE__, __PRETTY_FUNCTION__,
                     55:              addr_str);
                     56:     return -1;
                     57:   }
                     58: 
                     59:   first_ifindex = nexthop_tab[0].ifindex;
                     60: 
                     61:   if (num_ifindex > 1) {
                     62:     char addr_str[100];
                     63:     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
                     64:     zlog_info("%s %s: FIXME ignoring multiple nexthop ifindex'es num_ifindex=%d for address %s (using only ifindex=%d)",
                     65:              __FILE__, __PRETTY_FUNCTION__,
                     66:              num_ifindex, addr_str, first_ifindex);
                     67:     /* debug warning only, do not return */
                     68:   }
                     69: 
                     70:   ifp = if_lookup_by_index(first_ifindex);
                     71:   if (!ifp) {
                     72:     char addr_str[100];
                     73:     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
                     74:     zlog_warn("%s %s: could not find interface for ifindex %d (address %s)",
                     75:              __FILE__, __PRETTY_FUNCTION__,
                     76:              first_ifindex, addr_str);
                     77:     return -2;
                     78:   }
                     79: 
                     80:   if (!ifp->info) {
                     81:     char addr_str[100];
                     82:     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
                     83:     zlog_warn("%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
                     84:              __PRETTY_FUNCTION__,
                     85:              ifp->name, first_ifindex, addr_str);
                     86:     /* debug warning only, do not return */
                     87:   }
                     88: 
                     89:   if (PIM_DEBUG_PIM_TRACE) {
                     90:     char nexthop_str[100];
                     91:     char addr_str[100];
                     92:     pim_inet4_dump("<nexthop?>", nexthop_tab[0].nexthop_addr, nexthop_str, sizeof(nexthop_str));
                     93:     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
                     94:     zlog_debug("%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
                     95:               __FILE__, __PRETTY_FUNCTION__,
                     96:               nexthop_str, addr_str,
                     97:               ifp->name, first_ifindex,
                     98:               nexthop_tab[0].route_metric,
                     99:               nexthop_tab[0].protocol_distance);
                    100:   }
                    101: 
                    102:   /* update nextop data */
                    103:   nexthop->interface              = ifp;
                    104:   nexthop->mrib_nexthop_addr      = nexthop_tab[0].nexthop_addr;
                    105:   nexthop->mrib_metric_preference = nexthop_tab[0].protocol_distance;
                    106:   nexthop->mrib_route_metric      = nexthop_tab[0].route_metric;
                    107: 
                    108:   return 0;
                    109: }
                    110: 
                    111: static int nexthop_mismatch(const struct pim_nexthop *nh1,
                    112:                            const struct pim_nexthop *nh2)
                    113: {
                    114:   return (nh1->interface != nh2->interface) 
                    115:     ||
                    116:     (nh1->mrib_nexthop_addr.s_addr != nh2->mrib_nexthop_addr.s_addr)
                    117:     ||
                    118:     (nh1->mrib_metric_preference != nh2->mrib_metric_preference)
                    119:     ||
                    120:     (nh1->mrib_route_metric != nh2->mrib_route_metric);
                    121: }
                    122: 
                    123: enum pim_rpf_result pim_rpf_update(struct pim_upstream *up,
                    124:                                   struct in_addr *old_rpf_addr)
                    125: {
                    126:   struct in_addr      save_rpf_addr;
                    127:   struct pim_nexthop  save_nexthop;
                    128:   struct pim_rpf     *rpf = &up->rpf;
                    129: 
                    130:   save_nexthop  = rpf->source_nexthop; /* detect change in pim_nexthop */
                    131:   save_rpf_addr = rpf->rpf_addr;       /* detect change in RPF'(S,G) */
                    132: 
                    133:   if (pim_nexthop_lookup(&rpf->source_nexthop,
                    134:                         up->source_addr)) {
                    135:     return PIM_RPF_FAILURE;
                    136:   }
                    137: 
                    138:   rpf->rpf_addr = pim_rpf_find_rpf_addr(up);
                    139:   if (PIM_INADDR_IS_ANY(rpf->rpf_addr) && PIM_DEBUG_PIM_EVENTS) {
                    140:     /* RPF'(S,G) not found */
                    141:     char src_str[100];
                    142:     char grp_str[100];
                    143:     pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
                    144:     pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
                    145:     zlog_debug("%s %s: RPF'(%s,%s) not found: won't send join upstream",
                    146:               __FILE__, __PRETTY_FUNCTION__,
                    147:               src_str, grp_str);
                    148:     /* warning only */
                    149:   }
                    150: 
                    151:   /* detect change in pim_nexthop */
                    152:   if (nexthop_mismatch(&rpf->source_nexthop, &save_nexthop)) {
                    153: 
                    154:     if (PIM_DEBUG_PIM_EVENTS) {
                    155:       char src_str[100];
                    156:       char grp_str[100];
                    157:       char nhaddr_str[100];
                    158:       pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
                    159:       pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
                    160:       pim_inet4_dump("<addr?>", rpf->source_nexthop.mrib_nexthop_addr, nhaddr_str, sizeof(nhaddr_str));
                    161:       zlog_debug("%s %s: (S,G)=(%s,%s) source nexthop now is: interface=%s address=%s pref=%d metric=%d",
                    162:                 __FILE__, __PRETTY_FUNCTION__,
                    163:                 src_str, grp_str,
                    164:                 rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
                    165:                 nhaddr_str,
                    166:                 rpf->source_nexthop.mrib_metric_preference,
                    167:                 rpf->source_nexthop.mrib_route_metric);
                    168:       /* warning only */
                    169:     }
                    170: 
                    171:     pim_upstream_update_join_desired(up);
                    172:     pim_upstream_update_could_assert(up);
                    173:     pim_upstream_update_my_assert_metric(up);
                    174:   }
                    175: 
                    176:   /* detect change in RPF_interface(S) */
                    177:   if (save_nexthop.interface != rpf->source_nexthop.interface) {
                    178: 
                    179:     if (PIM_DEBUG_PIM_EVENTS) {
                    180:       char src_str[100];
                    181:       char grp_str[100];
                    182:       pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
                    183:       pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
                    184:       zlog_debug("%s %s: (S,G)=(%s,%s) RPF_interface(S) changed from %s to %s",
                    185:                 __FILE__, __PRETTY_FUNCTION__,
                    186:                 src_str, grp_str,
                    187:                 save_nexthop.interface ? save_nexthop.interface->name : "<oldif?>",
                    188:                 rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
                    189:       /* warning only */
                    190:     }
                    191: 
                    192:     pim_upstream_rpf_interface_changed(up, save_nexthop.interface);
                    193:   }
                    194: 
                    195:   /* detect change in RPF'(S,G) */
                    196:   if (save_rpf_addr.s_addr != rpf->rpf_addr.s_addr) {
                    197: 
                    198:     /* return old rpf to caller ? */
                    199:     if (old_rpf_addr)
                    200:       *old_rpf_addr = save_rpf_addr;
                    201: 
                    202:     return PIM_RPF_CHANGED;
                    203:   }
                    204: 
                    205:   return PIM_RPF_OK;
                    206: }
                    207: 
                    208: /*
                    209:   RFC 4601: 4.1.6.  State Summarization Macros
                    210: 
                    211:      neighbor RPF'(S,G) {
                    212:          if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
                    213:               return AssertWinner(S, G, RPF_interface(S) )
                    214:          } else {
                    215:               return NBR( RPF_interface(S), MRIB.next_hop( S ) )
                    216:          }
                    217:      }
                    218: 
                    219:   RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
                    220:   packets should be coming and to which joins should be sent on the RP
                    221:   tree and SPT, respectively.
                    222: */
                    223: static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
                    224: {
                    225:   struct pim_ifchannel *rpf_ch;
                    226:   struct pim_neighbor *neigh;
                    227:   struct in_addr rpf_addr;
                    228: 
                    229:   if (!up->rpf.source_nexthop.interface) {
                    230:     char src_str[100];
                    231:     char grp_str[100];
                    232:     pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
                    233:     pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
                    234:     zlog_warn("%s: missing RPF interface for upstream (S,G)=(%s,%s)",
                    235:              __PRETTY_FUNCTION__,
                    236:              src_str, grp_str);
                    237: 
                    238:     rpf_addr.s_addr = PIM_NET_INADDR_ANY;
                    239:     return rpf_addr;
                    240:   }
                    241: 
                    242:   rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface,
                    243:                              up->source_addr, up->group_addr);
                    244:   if (rpf_ch) {
                    245:     if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
                    246:       return rpf_ch->ifassert_winner;
                    247:     }
                    248:   }
                    249: 
                    250:   /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
                    251: 
                    252:   neigh = pim_if_find_neighbor(up->rpf.source_nexthop.interface,
                    253:                               up->rpf.source_nexthop.mrib_nexthop_addr);
                    254:   if (neigh)
                    255:     rpf_addr = neigh->source_addr;
                    256:   else
                    257:     rpf_addr.s_addr = PIM_NET_INADDR_ANY;
                    258: 
                    259:   return rpf_addr;
                    260: }

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