bgpd/bgp_nexthop.c

   1 /* BGP nexthop scan
   2    Copyright (C) 2000 Kunihiro Ishiguro
   3
   4 This file is part of GNU Zebra.
   5
   6 GNU Zebra is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GNU Zebra is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #include <zebra.h>
  22
  23 #include "command.h"
  24 #include "thread.h"
  25 #include "prefix.h"
  26 #include "zclient.h"
  27 #include "stream.h"
  28 #include "network.h"
  29 #include "log.h"
  30 #include "memory.h"
  31
  32 #include "bgpd/bgpd.h"
  33 #include "bgpd/bgp_table.h"
  34 #include "bgpd/bgp_route.h"
  35 #include "bgpd/bgp_attr.h"
  36 #include "bgpd/bgp_nexthop.h"
  37 #include "bgpd/bgp_debug.h"
  38 #include "bgpd/bgp_damp.h"
  39 #include "zebra/rib.h"
  40 #include "zebra/zserv.h"        /* For ZEBRA_SERV_PATH. */
  41
  42 struct bgp_nexthop_cache *zlookup_query (struct in_addr);
  43 #ifdef HAVE_IPV6
  44 struct bgp_nexthop_cache *zlookup_query_ipv6 (struct in6_addr *);
  45 #endif /* HAVE_IPV6 */
  46 \f
  47 /* Only one BGP scan thread are activated at the same time. */
  48 static struct thread *bgp_scan_thread = NULL;
  49
  50 /* BGP import thread */
  51 static struct thread *bgp_import_thread = NULL;
  52
  53 /* BGP scan interval. */
  54 static int bgp_scan_interval;
  55
  56 /* BGP import interval. */
  57 static int bgp_import_interval;
  58
  59 /* Route table for next-hop lookup cache. */
  60 static struct bgp_table *bgp_nexthop_cache_table[AFI_MAX];
  61 static struct bgp_table *cache1_table[AFI_MAX];
  62 static struct bgp_table *cache2_table[AFI_MAX];
  63
  64 /* Route table for connected route. */
  65 static struct bgp_table *bgp_connected_table[AFI_MAX];
  66
  67 /* BGP nexthop lookup query client. */
  68 static struct zclient *zlookup = NULL;
  69 \f
  70 /* Add nexthop to the end of the list.  */
  71 static void
  72 bnc_nexthop_add (struct bgp_nexthop_cache *bnc, struct nexthop *nexthop)
  73 {
  74   struct nexthop *last;
  75
  76   for (last = bnc->nexthop; last && last->next; last = last->next)
  77     ;
  78   if (last)
  79     last->next = nexthop;
  80   else
  81     bnc->nexthop = nexthop;
  82   nexthop->prev = last;
  83 }
  84
  85 static void
  86 bnc_nexthop_free (struct bgp_nexthop_cache *bnc)
  87 {
  88   struct nexthop *nexthop;
  89   struct nexthop *next = NULL;
  90
  91   for (nexthop = bnc->nexthop; nexthop; nexthop = next)
  92     {
  93       next = nexthop->next;
  94       XFREE (MTYPE_NEXTHOP, nexthop);
  95     }
  96 }
  97
  98 static struct bgp_nexthop_cache *
  99 bnc_new ()
 100 {
 101   struct bgp_nexthop_cache *new;
 102
 103   new = XMALLOC (MTYPE_BGP_NEXTHOP_CACHE, sizeof (struct bgp_nexthop_cache));
 104   memset (new, 0, sizeof (struct bgp_nexthop_cache));
 105   return new;
 106 }
 107
 108 static void
 109 bnc_free (struct bgp_nexthop_cache *bnc)
 110 {
 111   bnc_nexthop_free (bnc);
 112   XFREE (MTYPE_BGP_NEXTHOP_CACHE, bnc);
 113 }
 114 \f
 115 static int
 116 bgp_nexthop_same (struct nexthop *next1, struct nexthop *next2)
 117 {
 118   if (next1->type != next2->type)
 119     return 0;
 120
 121   switch (next1->type)
 122     {
 123     case ZEBRA_NEXTHOP_IPV4:
 124       if (! IPV4_ADDR_SAME (&next1->gate.ipv4, &next2->gate.ipv4))
 125         return 0;
 126       break;
 127     case ZEBRA_NEXTHOP_IFINDEX:
 128     case ZEBRA_NEXTHOP_IFNAME:
 129       if (next1->ifindex != next2->ifindex)
 130         return 0;
 131       break;
 132 #ifdef HAVE_IPV6
 133     case ZEBRA_NEXTHOP_IPV6:
 134       if (! IPV6_ADDR_SAME (&next1->gate.ipv6, &next2->gate.ipv6))
 135         return 0;
 136       break;
 137     case ZEBRA_NEXTHOP_IPV6_IFINDEX:
 138     case ZEBRA_NEXTHOP_IPV6_IFNAME:
 139       if (! IPV6_ADDR_SAME (&next1->gate.ipv6, &next2->gate.ipv6))
 140         return 0;
 141       if (next1->ifindex != next2->ifindex)
 142         return 0;
 143       break;
 144 #endif /* HAVE_IPV6 */
 145     default:
 146       /* do nothing */
 147       break;
 148     }
 149   return 1;
 150 }
 151
 152 static int
 153 bgp_nexthop_cache_changed (struct bgp_nexthop_cache *bnc1,
 154                            struct bgp_nexthop_cache *bnc2)
 155 {
 156   int i;
 157   struct nexthop *next1, *next2;
 158
 159   if (bnc1->nexthop_num != bnc2->nexthop_num)
 160     return 1;
 161
 162   next1 = bnc1->nexthop;
 163   next2 = bnc2->nexthop;
 164
 165   for (i = 0; i < bnc1->nexthop_num; i++)
 166     {
 167       if (! bgp_nexthop_same (next1, next2))
 168         return 1;
 169
 170       next1 = next1->next;
 171       next2 = next2->next;
 172     }
 173   return 0;
 174 }
 175
 176 /* If nexthop exists on connected network return 1. */
 177 int
 178 bgp_nexthop_check_ebgp (afi_t afi, struct attr *attr)
 179 {
 180   struct bgp_node *rn;
 181
 182   /* If zebra is not enabled return */
 183   if (zlookup->sock < 0)
 184     return 1;
 185
 186   /* Lookup the address is onlink or not. */
 187   if (afi == AFI_IP)
 188     {
 189       rn = bgp_node_match_ipv4 (bgp_connected_table[AFI_IP], &attr->nexthop);
 190       if (rn)
 191         {
 192           bgp_unlock_node (rn);
 193           return 1;
 194         }
 195     }
 196 #ifdef HAVE_IPV6
 197   else if (afi == AFI_IP6)
 198     {
 199       if (attr->mp_nexthop_len == 32)
 200         return 1;
 201       else if (attr->mp_nexthop_len == 16)
 202         {
 203           if (IN6_IS_ADDR_LINKLOCAL (&attr->mp_nexthop_global))
 204             return 1;
 205
 206           rn = bgp_node_match_ipv6 (bgp_connected_table[AFI_IP6],
 207                                       &attr->mp_nexthop_global);
 208           if (rn)
 209             {
 210               bgp_unlock_node (rn);
 211               return 1;
 212             }
 213         }
 214     }
 215 #endif /* HAVE_IPV6 */
 216   return 0;
 217 }
 218
 219 #ifdef HAVE_IPV6
 220 /* Check specified next-hop is reachable or not. */
 221 static int
 222 bgp_nexthop_lookup_ipv6 (struct peer *peer, struct bgp_info *ri, int *changed,
 223                          int *metricchanged)
 224 {
 225   struct bgp_node *rn;
 226   struct prefix p;
 227   struct bgp_nexthop_cache *bnc;
 228   struct attr *attr;
 229
 230   /* If lookup is not enabled, return valid. */
 231   if (zlookup->sock < 0)
 232     {
 233       ri->igpmetric = 0;
 234       return 1;
 235     }
 236
 237   /* Only check IPv6 global address only nexthop. */
 238   attr = ri->attr;
 239
 240   if (attr->mp_nexthop_len != 16
 241       || IN6_IS_ADDR_LINKLOCAL (&attr->mp_nexthop_global))
 242     return 1;
 243
 244   memset (&p, 0, sizeof (struct prefix));
 245   p.family = AF_INET6;
 246   p.prefixlen = IPV6_MAX_BITLEN;
 247   p.u.prefix6 = attr->mp_nexthop_global;
 248
 249   /* IBGP or ebgp-multihop */
 250   rn = bgp_node_get (bgp_nexthop_cache_table[AFI_IP6], &p);
 251
 252   if (rn->info)
 253     {
 254       bnc = rn->info;
 255       bgp_unlock_node (rn);
 256     }
 257   else
 258     {
 259       bnc = zlookup_query_ipv6 (&attr->mp_nexthop_global);
 260       if (bnc)
 261         {
 262           struct bgp_table *old;
 263           struct bgp_node *oldrn;
 264           struct bgp_nexthop_cache *oldbnc;
 265
 266           if (changed)
 267             {
 268               if (bgp_nexthop_cache_table[AFI_IP6] == cache1_table[AFI_IP6])
 269                 old = cache2_table[AFI_IP6];
 270               else
 271                 old = cache1_table[AFI_IP6];
 272
 273               oldrn = bgp_node_lookup (old, &p);
 274               if (oldrn)
 275                 {
 276                   oldbnc = oldrn->info;
 277
 278                   bnc->changed = bgp_nexthop_cache_changed (bnc, oldbnc);
 279
 280                   if (bnc->metric != oldbnc->metric)
 281                     bnc->metricchanged = 1;
 282                 }
 283             }
 284         }
 285       else
 286         {
 287           bnc = bnc_new ();
 288           bnc->valid = 0;
 289         }
 290       rn->info = bnc;
 291     }
 292
 293   if (changed)
 294     *changed = bnc->changed;
 295
 296   if (metricchanged)
 297     *metricchanged = bnc->metricchanged;
 298
 299   if (bnc->valid)
 300     ri->igpmetric = bnc->metric;
 301   else
 302     ri->igpmetric = 0;
 303
 304   return bnc->valid;
 305 }
 306 #endif /* HAVE_IPV6 */
 307
 308 /* Check specified next-hop is reachable or not. */
 309 int
 310 bgp_nexthop_lookup (afi_t afi, struct peer *peer, struct bgp_info *ri,
 311                     int *changed, int *metricchanged)
 312 {
 313   struct bgp_node *rn;
 314   struct prefix p;
 315   struct bgp_nexthop_cache *bnc;
 316   struct in_addr addr;
 317
 318   /* If lookup is not enabled, return valid. */
 319   if (zlookup->sock < 0)
 320     {
 321       ri->igpmetric = 0;
 322       return 1;
 323     }
 324
 325 #ifdef HAVE_IPV6
 326   if (afi == AFI_IP6)
 327     return bgp_nexthop_lookup_ipv6 (peer, ri, changed, metricchanged);
 328 #endif /* HAVE_IPV6 */
 329
 330   addr = ri->attr->nexthop;
 331
 332   memset (&p, 0, sizeof (struct prefix));
 333   p.family = AF_INET;
 334   p.prefixlen = IPV4_MAX_BITLEN;
 335   p.u.prefix4 = addr;
 336
 337   /* IBGP or ebgp-multihop */
 338   rn = bgp_node_get (bgp_nexthop_cache_table[AFI_IP], &p);
 339
 340   if (rn->info)
 341     {
 342       bnc = rn->info;
 343       bgp_unlock_node (rn);
 344     }
 345   else
 346     {
 347       bnc = zlookup_query (addr);
 348       if (bnc)
 349         {
 350           struct bgp_table *old;
 351           struct bgp_node *oldrn;
 352           struct bgp_nexthop_cache *oldbnc;
 353
 354           if (changed)
 355             {
 356               if (bgp_nexthop_cache_table[AFI_IP] == cache1_table[AFI_IP])
 357                 old = cache2_table[AFI_IP];
 358               else
 359                 old = cache1_table[AFI_IP];
 360
 361               oldrn = bgp_node_lookup (old, &p);
 362               if (oldrn)
 363                 {
 364                   oldbnc = oldrn->info;
 365
 366                   bnc->changed = bgp_nexthop_cache_changed (bnc, oldbnc);
 367
 368                   if (bnc->metric != oldbnc->metric)
 369                     bnc->metricchanged = 1;
 370                 }
 371             }
 372         }
 373       else
 374         {
 375           bnc = bnc_new ();
 376           bnc->valid = 0;
 377         }
 378       rn->info = bnc;
 379     }
 380
 381   if (changed)
 382     *changed = bnc->changed;
 383
 384   if (metricchanged)
 385     *metricchanged = bnc->metricchanged;
 386
 387   if (bnc->valid)
 388     ri->igpmetric = bnc->metric;
 389   else
 390     ri->igpmetric = 0;
 391
 392   return bnc->valid;
 393 }
 394
 395 /* Reset and free all BGP nexthop cache. */
 396 static void
 397 bgp_nexthop_cache_reset (struct bgp_table *table)
 398 {
 399   struct bgp_node *rn;
 400   struct bgp_nexthop_cache *bnc;
 401
 402   for (rn = bgp_table_top (table); rn; rn = bgp_route_next (rn))
 403     if ((bnc = rn->info) != NULL)
 404       {
 405         bnc_free (bnc);
 406         rn->info = NULL;
 407         bgp_unlock_node (rn);
 408       }
 409 }
 410
 411 static void
 412 bgp_scan (afi_t afi, safi_t safi)
 413 {
 414   struct bgp_node *rn;
 415   struct bgp *bgp;
 416   struct bgp_info *bi;
 417   struct bgp_info *next;
 418   struct peer *peer;
 419   struct listnode *node, *nnode;
 420   int valid;
 421   int current;
 422   int changed;
 423   int metricchanged;
 424
 425   /* Change cache. */
 426   if (bgp_nexthop_cache_table[afi] == cache1_table[afi])
 427     bgp_nexthop_cache_table[afi] = cache2_table[afi];
 428   else
 429     bgp_nexthop_cache_table[afi] = cache1_table[afi];
 430
 431   /* Get default bgp. */
 432   bgp = bgp_get_default ();
 433   if (bgp == NULL)
 434     return;
 435
 436   /* Maximum prefix check */
 437   for (ALL_LIST_ELEMENTS (bgp->peer, node, nnode, peer))
 438     {
 439       if (peer->status != Established)
 440         continue;
 441
 442       if (peer->afc[afi][SAFI_UNICAST])
 443         bgp_maximum_prefix_overflow (peer, afi, SAFI_UNICAST, 1);
 444       if (peer->afc[afi][SAFI_MULTICAST])
 445         bgp_maximum_prefix_overflow (peer, afi, SAFI_MULTICAST, 1);
 446       if (peer->afc[afi][SAFI_MPLS_VPN])
 447         bgp_maximum_prefix_overflow (peer, afi, SAFI_MPLS_VPN, 1);
 448     }
 449
 450   for (rn = bgp_table_top (bgp->rib[afi][SAFI_UNICAST]); rn;
 451        rn = bgp_route_next (rn))
 452     {
 453       for (bi = rn->info; bi; bi = next)
 454         {
 455           next = bi->next;
 456
 457           if (bi->type == ZEBRA_ROUTE_BGP && bi->sub_type == BGP_ROUTE_NORMAL)
 458             {
 459               changed = 0;
 460               metricchanged = 0;
 461
 462               if (peer_sort (bi->peer) == BGP_PEER_EBGP && bi->peer->ttl == 1)
 463                 valid = bgp_nexthop_check_ebgp (afi, bi->attr);
 464               else
 465                 valid = bgp_nexthop_lookup (afi, bi->peer, bi,
 466                                             &changed, &metricchanged);
 467
 468               current = CHECK_FLAG (bi->flags, BGP_INFO_VALID) ? 1 : 0;
 469
 470               if (changed)
 471                 SET_FLAG (bi->flags, BGP_INFO_IGP_CHANGED);
 472               else
 473                 UNSET_FLAG (bi->flags, BGP_INFO_IGP_CHANGED);
 474
 475               if (valid != current)
 476                 {
 477                   if (CHECK_FLAG (bi->flags, BGP_INFO_VALID))
 478                     {
 479                       bgp_aggregate_decrement (bgp, &rn->p, bi,
 480                                                afi, SAFI_UNICAST);
 481                       bgp_info_unset_flag (rn, bi, BGP_INFO_VALID);
 482                     }
 483                   else
 484                     {
 485                       bgp_info_set_flag (rn, bi, BGP_INFO_VALID);
 486                       bgp_aggregate_increment (bgp, &rn->p, bi,
 487                                                afi, SAFI_UNICAST);
 488                     }
 489                 }
 490
 491               if (CHECK_FLAG (bgp->af_flags[afi][SAFI_UNICAST],
 492                   BGP_CONFIG_DAMPENING)
 493                   &&  bi->damp_info )
 494                 if (bgp_damp_scan (bi, afi, SAFI_UNICAST))
 495                   bgp_aggregate_increment (bgp, &rn->p, bi,
 496                                            afi, SAFI_UNICAST);
 497             }
 498         }
 499       bgp_process (bgp, rn, afi, SAFI_UNICAST);
 500     }
 501
 502   /* Flash old cache. */
 503   if (bgp_nexthop_cache_table[afi] == cache1_table[afi])
 504     bgp_nexthop_cache_reset (cache2_table[afi]);
 505   else
 506     bgp_nexthop_cache_reset (cache1_table[afi]);
 507
 508   if (BGP_DEBUG (events, EVENTS))
 509     {
 510       if (afi == AFI_IP)
 511         zlog_debug ("scanning IPv4 Unicast routing tables");
 512       else if (afi == AFI_IP6)
 513         zlog_debug ("scanning IPv6 Unicast routing tables");
 514     }
 515 }
 516
 517 /* BGP scan thread.  This thread check nexthop reachability. */
 518 static int
 519 bgp_scan_timer (struct thread *t)
 520 {
 521   bgp_scan_thread =
 522     thread_add_timer (master, bgp_scan_timer, NULL, bgp_scan_interval);
 523
 524   if (BGP_DEBUG (events, EVENTS))
 525     zlog_debug ("Performing BGP general scanning");
 526
 527   bgp_scan (AFI_IP, SAFI_UNICAST);
 528
 529 #ifdef HAVE_IPV6
 530   bgp_scan (AFI_IP6, SAFI_UNICAST);
 531 #endif /* HAVE_IPV6 */
 532
 533   return 0;
 534 }
 535 \f
 536 struct bgp_connected_ref
 537 {
 538   unsigned int refcnt;
 539 };
 540
 541 void
 542 bgp_connected_add (struct connected *ifc)
 543 {
 544   struct prefix p;
 545   struct prefix *addr;
 546   struct interface *ifp;
 547   struct bgp_node *rn;
 548   struct bgp_connected_ref *bc;
 549
 550   ifp = ifc->ifp;
 551
 552   if (! ifp)
 553     return;
 554
 555   if (if_is_loopback (ifp))
 556     return;
 557
 558   addr = ifc->address;
 559
 560   if (addr->family == AF_INET)
 561     {
 562       PREFIX_COPY_IPV4(&p, CONNECTED_PREFIX(ifc));
 563       apply_mask_ipv4 ((struct prefix_ipv4 *) &p);
 564
 565       if (prefix_ipv4_any ((struct prefix_ipv4 *) &p))
 566         return;
 567
 568       rn = bgp_node_get (bgp_connected_table[AFI_IP], (struct prefix *) &p);
 569       if (rn->info)
 570         {
 571           bc = rn->info;
 572           bc->refcnt++;
 573         }
 574       else
 575         {
 576           bc = XMALLOC (0, sizeof (struct bgp_connected_ref));
 577           memset (bc, 0, sizeof (struct bgp_connected_ref));
 578           bc->refcnt = 1;
 579           rn->info = bc;
 580         }
 581     }
 582 #ifdef HAVE_IPV6
 583   else if (addr->family == AF_INET6)
 584     {
 585       PREFIX_COPY_IPV6(&p, CONNECTED_PREFIX(ifc));
 586       apply_mask_ipv6 ((struct prefix_ipv6 *) &p);
 587
 588       if (IN6_IS_ADDR_UNSPECIFIED (&p.u.prefix6))
 589         return;
 590
 591       if (IN6_IS_ADDR_LINKLOCAL (&p.u.prefix6))
 592         return;
 593
 594       rn = bgp_node_get (bgp_connected_table[AFI_IP6], (struct prefix *) &p);
 595       if (rn->info)
 596         {
 597           bc = rn->info;
 598           bc->refcnt++;
 599         }
 600       else
 601         {
 602           bc = XMALLOC (0, sizeof (struct bgp_connected_ref));
 603           memset (bc, 0, sizeof (struct bgp_connected_ref));
 604           bc->refcnt = 1;
 605           rn->info = bc;
 606         }
 607     }
 608 #endif /* HAVE_IPV6 */
 609 }
 610
 611 void
 612 bgp_connected_delete (struct connected *ifc)
 613 {
 614   struct prefix p;
 615   struct prefix *addr;
 616   struct interface *ifp;
 617   struct bgp_node *rn;
 618   struct bgp_connected_ref *bc;
 619
 620   ifp = ifc->ifp;
 621
 622   if (if_is_loopback (ifp))
 623     return;
 624
 625   addr = ifc->address;
 626
 627   if (addr->family == AF_INET)
 628     {
 629       PREFIX_COPY_IPV4(&p, CONNECTED_PREFIX(ifc));
 630       apply_mask_ipv4 ((struct prefix_ipv4 *) &p);
 631
 632       if (prefix_ipv4_any ((struct prefix_ipv4 *) &p))
 633         return;
 634
 635       rn = bgp_node_lookup (bgp_connected_table[AFI_IP], &p);
 636       if (! rn)
 637         return;
 638
 639       bc = rn->info;
 640       bc->refcnt--;
 641       if (bc->refcnt == 0)
 642         {
 643           XFREE (0, bc);
 644           rn->info = NULL;
 645         }
 646       bgp_unlock_node (rn);
 647       bgp_unlock_node (rn);
 648     }
 649 #ifdef HAVE_IPV6
 650   else if (addr->family == AF_INET6)
 651     {
 652       PREFIX_COPY_IPV6(&p, CONNECTED_PREFIX(ifc));
 653       apply_mask_ipv6 ((struct prefix_ipv6 *) &p);
 654
 655       if (IN6_IS_ADDR_UNSPECIFIED (&p.u.prefix6))
 656         return;
 657
 658       if (IN6_IS_ADDR_LINKLOCAL (&p.u.prefix6))
 659         return;
 660
 661       rn = bgp_node_lookup (bgp_connected_table[AFI_IP6], (struct prefix *) &p);
 662       if (! rn)
 663         return;
 664
 665       bc = rn->info;
 666       bc->refcnt--;
 667       if (bc->refcnt == 0)
 668         {
 669           XFREE (0, bc);
 670           rn->info = NULL;
 671         }
 672       bgp_unlock_node (rn);
 673       bgp_unlock_node (rn);
 674     }
 675 #endif /* HAVE_IPV6 */
 676 }
 677
 678 int
 679 bgp_nexthop_self (afi_t afi, struct attr *attr)
 680 {
 681   struct listnode *node;
 682   struct listnode *node2;
 683   struct interface *ifp;
 684   struct connected *ifc;
 685   struct prefix *p;
 686
 687   for (ALL_LIST_ELEMENTS_RO (iflist, node, ifp))
 688     {
 689       for (ALL_LIST_ELEMENTS_RO (ifp->connected, node2, ifc))
 690         {
 691           p = ifc->address;
 692
 693           if (p && p->family == AF_INET
 694               && IPV4_ADDR_SAME (&p->u.prefix4, &attr->nexthop))
 695             return 1;
 696         }
 697     }
 698   return 0;
 699 }
 700 \f
 701 static struct bgp_nexthop_cache *
 702 zlookup_read ()
 703 {
 704   struct stream *s;
 705   uint16_t length;
 706   u_char marker;
 707   u_char version;
 708   uint16_t command;
 709   int nbytes;
 710   struct in_addr raddr;
 711   uint32_t metric;
 712   int i;
 713   u_char nexthop_num;
 714   struct nexthop *nexthop;
 715   struct bgp_nexthop_cache *bnc;
 716
 717   s = zlookup->ibuf;
 718   stream_reset (s);
 719
 720   nbytes = stream_read (s, zlookup->sock, 2);
 721   length = stream_getw (s);
 722
 723   nbytes = stream_read (s, zlookup->sock, length - 2);
 724   marker = stream_getc (s);
 725   version = stream_getc (s);
 726
 727   if (version != ZSERV_VERSION || marker != ZEBRA_HEADER_MARKER)
 728     {
 729       zlog_err("%s: socket %d version mismatch, marker %d, version %d",
 730                __func__, zlookup->sock, marker, version);
 731       return NULL;
 732     }
 733
 734   command = stream_getw (s);
 735
 736   raddr.s_addr = stream_get_ipv4 (s);
 737   metric = stream_getl (s);
 738   nexthop_num = stream_getc (s);
 739
 740   if (nexthop_num)
 741     {
 742       bnc = bnc_new ();
 743       bnc->valid = 1;
 744       bnc->metric = metric;
 745       bnc->nexthop_num = nexthop_num;
 746
 747       for (i = 0; i < nexthop_num; i++)
 748         {
 749           nexthop = XMALLOC (MTYPE_NEXTHOP, sizeof (struct nexthop));
 750           memset (nexthop, 0, sizeof (struct nexthop));
 751           nexthop->type = stream_getc (s);
 752           switch (nexthop->type)
 753             {
 754             case ZEBRA_NEXTHOP_IPV4:
 755               nexthop->gate.ipv4.s_addr = stream_get_ipv4 (s);
 756               break;
 757             case ZEBRA_NEXTHOP_IFINDEX:
 758             case ZEBRA_NEXTHOP_IFNAME:
 759               nexthop->ifindex = stream_getl (s);
 760               break;
 761             default:
 762               /* do nothing */
 763               break;
 764             }
 765           bnc_nexthop_add (bnc, nexthop);
 766         }
 767     }
 768   else
 769     return NULL;
 770
 771   return bnc;
 772 }
 773
 774 struct bgp_nexthop_cache *
 775 zlookup_query (struct in_addr addr)
 776 {
 777   int ret;
 778   struct stream *s;
 779
 780   /* Check socket. */
 781   if (zlookup->sock < 0)
 782     return NULL;
 783
 784   s = zlookup->obuf;
 785   stream_reset (s);
 786   zclient_create_header (s, ZEBRA_IPV4_NEXTHOP_LOOKUP);
 787   stream_put_in_addr (s, &addr);
 788
 789   stream_putw_at (s, 0, stream_get_endp (s));
 790
 791   ret = writen (zlookup->sock, s->data, stream_get_endp (s));
 792   if (ret < 0)
 793     {
 794       zlog_err ("can't write to zlookup->sock");
 795       close (zlookup->sock);
 796       zlookup->sock = -1;
 797       return NULL;
 798     }
 799   if (ret == 0)
 800     {
 801       zlog_err ("zlookup->sock connection closed");
 802       close (zlookup->sock);
 803       zlookup->sock = -1;
 804       return NULL;
 805     }
 806
 807   return zlookup_read ();
 808 }
 809
 810 #ifdef HAVE_IPV6
 811 static struct bgp_nexthop_cache *
 812 zlookup_read_ipv6 ()
 813 {
 814   struct stream *s;
 815   uint16_t length;
 816   u_char version, marker;
 817   uint16_t  command;
 818   int nbytes;
 819   struct in6_addr raddr;
 820   uint32_t metric;
 821   int i;
 822   u_char nexthop_num;
 823   struct nexthop *nexthop;
 824   struct bgp_nexthop_cache *bnc;
 825
 826   s = zlookup->ibuf;
 827   stream_reset (s);
 828
 829   nbytes = stream_read (s, zlookup->sock, 2);
 830   length = stream_getw (s);
 831
 832   nbytes = stream_read (s, zlookup->sock, length - 2);
 833   marker = stream_getc (s);
 834   version = stream_getc (s);
 835
 836   if (version != ZSERV_VERSION || marker != ZEBRA_HEADER_MARKER)
 837     {
 838       zlog_err("%s: socket %d version mismatch, marker %d, version %d",
 839                __func__, zlookup->sock, marker, version);
 840       return NULL;
 841     }
 842
 843   command = stream_getw (s);
 844
 845   stream_get (&raddr, s, 16);
 846
 847   metric = stream_getl (s);
 848   nexthop_num = stream_getc (s);
 849
 850   if (nexthop_num)
 851     {
 852       bnc = bnc_new ();
 853       bnc->valid = 1;
 854       bnc->metric = metric;
 855       bnc->nexthop_num = nexthop_num;
 856
 857       for (i = 0; i < nexthop_num; i++)
 858         {
 859           nexthop = XMALLOC (MTYPE_NEXTHOP, sizeof (struct nexthop));
 860           memset (nexthop, 0, sizeof (struct nexthop));
 861           nexthop->type = stream_getc (s);
 862           switch (nexthop->type)
 863             {
 864             case ZEBRA_NEXTHOP_IPV6:
 865               stream_get (&nexthop->gate.ipv6, s, 16);
 866               break;
 867             case ZEBRA_NEXTHOP_IPV6_IFINDEX:
 868             case ZEBRA_NEXTHOP_IPV6_IFNAME:
 869               stream_get (&nexthop->gate.ipv6, s, 16);
 870               nexthop->ifindex = stream_getl (s);
 871               break;
 872             case ZEBRA_NEXTHOP_IFINDEX:
 873             case ZEBRA_NEXTHOP_IFNAME:
 874               nexthop->ifindex = stream_getl (s);
 875               break;
 876             default:
 877               /* do nothing */
 878               break;
 879             }
 880           bnc_nexthop_add (bnc, nexthop);
 881         }
 882     }
 883   else
 884     return NULL;
 885
 886   return bnc;
 887 }
 888
 889 struct bgp_nexthop_cache *
 890 zlookup_query_ipv6 (struct in6_addr *addr)
 891 {
 892   int ret;
 893   struct stream *s;
 894
 895   /* Check socket. */
 896   if (zlookup->sock < 0)
 897     return NULL;
 898
 899   s = zlookup->obuf;
 900   stream_reset (s);
 901   zclient_create_header (s, ZEBRA_IPV6_NEXTHOP_LOOKUP);
 902   stream_put (s, addr, 16);
 903   stream_putw_at (s, 0, stream_get_endp (s));
 904
 905   ret = writen (zlookup->sock, s->data, stream_get_endp (s));
 906   if (ret < 0)
 907     {
 908       zlog_err ("can't write to zlookup->sock");
 909       close (zlookup->sock);
 910       zlookup->sock = -1;
 911       return NULL;
 912     }
 913   if (ret == 0)
 914     {
 915       zlog_err ("zlookup->sock connection closed");
 916       close (zlookup->sock);
 917       zlookup->sock = -1;
 918       return NULL;
 919     }
 920
 921   return zlookup_read_ipv6 ();
 922 }
 923 #endif /* HAVE_IPV6 */
 924
 925 static int
 926 bgp_import_check (struct prefix *p, u_int32_t *igpmetric,
 927                   struct in_addr *igpnexthop)
 928 {
 929   struct stream *s;
 930   int ret;
 931   u_int16_t length, command;
 932   u_char version, marker;
 933   int nbytes;
 934   struct in_addr addr;
 935   struct in_addr nexthop;
 936   u_int32_t metric = 0;
 937   u_char nexthop_num;
 938   u_char nexthop_type;
 939
 940   /* If lookup connection is not available return valid. */
 941   if (zlookup->sock < 0)
 942     {
 943       if (igpmetric)
 944         *igpmetric = 0;
 945       return 1;
 946     }
 947
 948   /* Send query to the lookup connection */
 949   s = zlookup->obuf;
 950   stream_reset (s);
 951   zclient_create_header (s, ZEBRA_IPV4_IMPORT_LOOKUP);
 952
 953   stream_putc (s, p->prefixlen);
 954   stream_put_in_addr (s, &p->u.prefix4);
 955
 956   stream_putw_at (s, 0, stream_get_endp (s));
 957
 958   /* Write the packet. */
 959   ret = writen (zlookup->sock, s->data, stream_get_endp (s));
 960
 961   if (ret < 0)
 962     {
 963       zlog_err ("can't write to zlookup->sock");
 964       close (zlookup->sock);
 965       zlookup->sock = -1;
 966       return 1;
 967     }
 968   if (ret == 0)
 969     {
 970       zlog_err ("zlookup->sock connection closed");
 971       close (zlookup->sock);
 972       zlookup->sock = -1;
 973       return 1;
 974     }
 975
 976   /* Get result. */
 977   stream_reset (s);
 978
 979   /* Fetch length. */
 980   nbytes = stream_read (s, zlookup->sock, 2);
 981   length = stream_getw (s);
 982
 983   /* Fetch whole data. */
 984   nbytes = stream_read (s, zlookup->sock, length - 2);
 985   marker = stream_getc (s);
 986   version = stream_getc (s);
 987
 988   if (version != ZSERV_VERSION || marker != ZEBRA_HEADER_MARKER)
 989     {
 990       zlog_err("%s: socket %d version mismatch, marker %d, version %d",
 991                __func__, zlookup->sock, marker, version);
 992       return 0;
 993     }
 994
 995   command = stream_getw (s);
 996
 997   addr.s_addr = stream_get_ipv4 (s);
 998   metric = stream_getl (s);
 999   nexthop_num = stream_getc (s);
1000
1001   /* Set IGP metric value. */
1002   if (igpmetric)
1003     *igpmetric = metric;
1004
1005   /* If there is nexthop then this is active route. */
1006   if (nexthop_num)
1007     {
1008       nexthop.s_addr = 0;
1009       nexthop_type = stream_getc (s);
1010       if (nexthop_type == ZEBRA_NEXTHOP_IPV4)
1011         {
1012           nexthop.s_addr = stream_get_ipv4 (s);
1013           if (igpnexthop)
1014             *igpnexthop = nexthop;
1015         }
1016       else
1017         *igpnexthop = nexthop;
1018
1019       return 1;
1020     }
1021   else
1022     return 0;
1023 }
1024
1025 /* Scan all configured BGP route then check the route exists in IGP or
1026    not. */
1027 static int
1028 bgp_import (struct thread *t)
1029 {
1030   struct bgp *bgp;
1031   struct bgp_node *rn;
1032   struct bgp_static *bgp_static;
1033   struct listnode *node, *nnode;
1034   int valid;
1035   u_int32_t metric;
1036   struct in_addr nexthop;
1037   afi_t afi;
1038   safi_t safi;
1039
1040   bgp_import_thread =
1041     thread_add_timer (master, bgp_import, NULL, bgp_import_interval);
1042
1043   if (BGP_DEBUG (events, EVENTS))
1044     zlog_debug ("Import timer expired.");
1045
1046   for (ALL_LIST_ELEMENTS (bm->bgp, node, nnode, bgp))
1047     {
1048       for (afi = AFI_IP; afi < AFI_MAX; afi++)
1049         for (safi = SAFI_UNICAST; safi < SAFI_MPLS_VPN; safi++)
1050           for (rn = bgp_table_top (bgp->route[afi][safi]); rn;
1051                rn = bgp_route_next (rn))
1052             if ((bgp_static = rn->info) != NULL)
1053               {
1054                 if (bgp_static->backdoor)
1055                   continue;
1056
1057                 valid = bgp_static->valid;
1058                 metric = bgp_static->igpmetric;
1059                 nexthop = bgp_static->igpnexthop;
1060
1061                 if (bgp_flag_check (bgp, BGP_FLAG_IMPORT_CHECK)
1062                     && afi == AFI_IP && safi == SAFI_UNICAST)
1063                   bgp_static->valid = bgp_import_check (&rn->p, &bgp_static->igpmetric,
1064                                                         &bgp_static->igpnexthop);
1065                 else
1066                   {
1067                     bgp_static->valid = 1;
1068                     bgp_static->igpmetric = 0;
1069                     bgp_static->igpnexthop.s_addr = 0;
1070                   }
1071
1072                 if (bgp_static->valid != valid)
1073                   {
1074                     if (bgp_static->valid)
1075                       bgp_static_update (bgp, &rn->p, bgp_static, afi, safi);
1076                     else
1077                       bgp_static_withdraw (bgp, &rn->p, afi, safi);
1078                   }
1079                 else if (bgp_static->valid)
1080                   {
1081                     if (bgp_static->igpmetric != metric
1082                         || bgp_static->igpnexthop.s_addr != nexthop.s_addr
1083                         || bgp_static->rmap.name)
1084                       bgp_static_update (bgp, &rn->p, bgp_static, afi, safi);
1085                   }
1086               }
1087     }
1088   return 0;
1089 }
1090
1091 /* Connect to zebra for nexthop lookup. */
1092 static int
1093 zlookup_connect (struct thread *t)
1094 {
1095   struct zclient *zlookup;
1096
1097   zlookup = THREAD_ARG (t);
1098   zlookup->t_connect = NULL;
1099
1100   if (zlookup->sock != -1)
1101     return 0;
1102
1103 #ifdef HAVE_TCP_ZEBRA
1104   zlookup->sock = zclient_socket ();
1105 #else
1106   zlookup->sock = zclient_socket_un (ZEBRA_SERV_PATH);
1107 #endif /* HAVE_TCP_ZEBRA */
1108   if (zlookup->sock < 0)
1109     return -1;
1110
1111   return 0;
1112 }
1113
1114 /* Check specified multiaccess next-hop. */
1115 int
1116 bgp_multiaccess_check_v4 (struct in_addr nexthop, char *peer)
1117 {
1118   struct bgp_node *rn1;
1119   struct bgp_node *rn2;
1120   struct prefix p1;
1121   struct prefix p2;
1122   struct in_addr addr;
1123   int ret;
1124
1125   ret = inet_aton (peer, &addr);
1126   if (! ret)
1127     return 0;
1128
1129   memset (&p1, 0, sizeof (struct prefix));
1130   p1.family = AF_INET;
1131   p1.prefixlen = IPV4_MAX_BITLEN;
1132   p1.u.prefix4 = nexthop;
1133   memset (&p2, 0, sizeof (struct prefix));
1134   p2.family = AF_INET;
1135   p2.prefixlen = IPV4_MAX_BITLEN;
1136   p2.u.prefix4 = addr;
1137
1138   /* If bgp scan is not enabled, return invalid. */
1139   if (zlookup->sock < 0)
1140     return 0;
1141
1142   rn1 = bgp_node_match (bgp_connected_table[AFI_IP], &p1);
1143   if (! rn1)
1144     return 0;
1145
1146   rn2 = bgp_node_match (bgp_connected_table[AFI_IP], &p2);
1147   if (! rn2)
1148     return 0;
1149
1150   if (rn1 == rn2)
1151     return 1;
1152
1153   return 0;
1154 }
1155 \f
1156 DEFUN (bgp_scan_time,
1157        bgp_scan_time_cmd,
1158        "bgp scan-time <5-60>",
1159        "BGP specific commands\n"
1160        "Configure background scanner interval\n"
1161        "Scanner interval (seconds)\n")
1162 {
1163   bgp_scan_interval = atoi (argv[0]);
1164
1165   if (bgp_scan_thread)
1166     {
1167       thread_cancel (bgp_scan_thread);
1168       bgp_scan_thread =
1169         thread_add_timer (master, bgp_scan_timer, NULL, bgp_scan_interval);
1170     }
1171
1172   return CMD_SUCCESS;
1173 }
1174
1175 DEFUN (no_bgp_scan_time,
1176        no_bgp_scan_time_cmd,
1177        "no bgp scan-time",
1178        NO_STR
1179        "BGP specific commands\n"
1180        "Configure background scanner interval\n")
1181 {
1182   bgp_scan_interval = BGP_SCAN_INTERVAL_DEFAULT;
1183
1184   if (bgp_scan_thread)
1185     {
1186       thread_cancel (bgp_scan_thread);
1187       bgp_scan_thread =
1188         thread_add_timer (master, bgp_scan_timer, NULL, bgp_scan_interval);
1189     }
1190
1191   return CMD_SUCCESS;
1192 }
1193
1194 ALIAS (no_bgp_scan_time,
1195        no_bgp_scan_time_val_cmd,
1196        "no bgp scan-time <5-60>",
1197        NO_STR
1198        "BGP specific commands\n"
1199        "Configure background scanner interval\n"
1200        "Scanner interval (seconds)\n")
1201
1202 DEFUN (show_ip_bgp_scan,
1203        show_ip_bgp_scan_cmd,
1204        "show ip bgp scan",
1205        SHOW_STR
1206        IP_STR
1207        BGP_STR
1208        "BGP scan status\n")
1209 {
1210   struct bgp_node *rn;
1211   struct bgp_nexthop_cache *bnc;
1212
1213   if (bgp_scan_thread)
1214     vty_out (vty, "BGP scan is running%s", VTY_NEWLINE);
1215   else
1216     vty_out (vty, "BGP scan is not running%s", VTY_NEWLINE);
1217   vty_out (vty, "BGP scan interval is %d%s", bgp_scan_interval, VTY_NEWLINE);
1218
1219   vty_out (vty, "Current BGP nexthop cache:%s", VTY_NEWLINE);
1220   for (rn = bgp_table_top (bgp_nexthop_cache_table[AFI_IP]); rn; rn = bgp_route_next (rn))
1221     if ((bnc = rn->info) != NULL)
1222       {
1223         if (bnc->valid)
1224           vty_out (vty, " %s valid [IGP metric %d]%s",
1225                    inet_ntoa (rn->p.u.prefix4), bnc->metric, VTY_NEWLINE);
1226         else
1227           vty_out (vty, " %s invalid%s",
1228                    inet_ntoa (rn->p.u.prefix4), VTY_NEWLINE);
1229       }
1230
1231 #ifdef HAVE_IPV6
1232   {
1233     char buf[BUFSIZ];
1234     for (rn = bgp_table_top (bgp_nexthop_cache_table[AFI_IP6]);
1235          rn;
1236          rn = bgp_route_next (rn))
1237       if ((bnc = rn->info) != NULL)
1238         {
1239           if (bnc->valid)
1240             vty_out (vty, " %s valid [IGP metric %d]%s",
1241                      inet_ntop (AF_INET6, &rn->p.u.prefix6, buf, BUFSIZ),
1242                      bnc->metric, VTY_NEWLINE);
1243           else
1244             vty_out (vty, " %s invalid%s",
1245                      inet_ntop (AF_INET6, &rn->p.u.prefix6, buf, BUFSIZ),
1246                      VTY_NEWLINE);
1247         }
1248   }
1249 #endif /* HAVE_IPV6 */
1250
1251   vty_out (vty, "BGP connected route:%s", VTY_NEWLINE);
1252   for (rn = bgp_table_top (bgp_connected_table[AFI_IP]);
1253        rn;
1254        rn = bgp_route_next (rn))
1255     if (rn->info != NULL)
1256       vty_out (vty, " %s/%d%s", inet_ntoa (rn->p.u.prefix4), rn->p.prefixlen,
1257                VTY_NEWLINE);
1258
1259 #ifdef HAVE_IPV6
1260   {
1261     char buf[BUFSIZ];
1262
1263     for (rn = bgp_table_top (bgp_connected_table[AFI_IP6]);
1264          rn;
1265          rn = bgp_route_next (rn))
1266       if (rn->info != NULL)
1267         vty_out (vty, " %s/%d%s",
1268                  inet_ntop (AF_INET6, &rn->p.u.prefix6, buf, BUFSIZ),
1269                  rn->p.prefixlen,
1270                  VTY_NEWLINE);
1271   }
1272 #endif /* HAVE_IPV6 */
1273
1274   return CMD_SUCCESS;
1275 }
1276
1277 int
1278 bgp_config_write_scan_time (struct vty *vty)
1279 {
1280   if (bgp_scan_interval != BGP_SCAN_INTERVAL_DEFAULT)
1281     vty_out (vty, " bgp scan-time %d%s", bgp_scan_interval, VTY_NEWLINE);
1282   return CMD_SUCCESS;
1283 }
1284
1285 void
1286 bgp_scan_init ()
1287 {
1288   zlookup = zclient_new ();
1289   zlookup->sock = -1;
1290   zlookup->ibuf = stream_new (ZEBRA_MAX_PACKET_SIZ);
1291   zlookup->obuf = stream_new (ZEBRA_MAX_PACKET_SIZ);
1292   zlookup->t_connect = thread_add_event (master, zlookup_connect, zlookup, 0);
1293
1294   bgp_scan_interval = BGP_SCAN_INTERVAL_DEFAULT;
1295   bgp_import_interval = BGP_IMPORT_INTERVAL_DEFAULT;
1296
1297   cache1_table[AFI_IP] = bgp_table_init (AFI_IP, SAFI_UNICAST);
1298   cache2_table[AFI_IP] = bgp_table_init (AFI_IP, SAFI_UNICAST);
1299   bgp_nexthop_cache_table[AFI_IP] = cache1_table[AFI_IP];
1300
1301   bgp_connected_table[AFI_IP] = bgp_table_init (AFI_IP, SAFI_UNICAST);
1302
1303 #ifdef HAVE_IPV6
1304   cache1_table[AFI_IP6] = bgp_table_init (AFI_IP6, SAFI_UNICAST);
1305   cache2_table[AFI_IP6] = bgp_table_init (AFI_IP6, SAFI_UNICAST);
1306   bgp_nexthop_cache_table[AFI_IP6] = cache1_table[AFI_IP6];
1307   bgp_connected_table[AFI_IP6] = bgp_table_init (AFI_IP6, SAFI_UNICAST);
1308 #endif /* HAVE_IPV6 */
1309
1310   /* Make BGP scan thread. */
1311   bgp_scan_thread = thread_add_timer (master, bgp_scan_timer,
1312                                       NULL, bgp_scan_interval);
1313   /* Make BGP import there. */
1314   bgp_import_thread = thread_add_timer (master, bgp_import, NULL, 0);
1315
1316   install_element (BGP_NODE, &bgp_scan_time_cmd);
1317   install_element (BGP_NODE, &no_bgp_scan_time_cmd);
1318   install_element (BGP_NODE, &no_bgp_scan_time_val_cmd);
1319   install_element (VIEW_NODE, &show_ip_bgp_scan_cmd);
1320   install_element (ENABLE_NODE, &show_ip_bgp_scan_cmd);
1321 }