Annotation of embedaddon/quagga/bgpd/bgp_advertise.c, revision 1.1.1.1

1.1       misho       1: /* BGP advertisement and adjacency
                      2:    Copyright (C) 1996, 97, 98, 99, 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 "memory.h"
                     25: #include "prefix.h"
                     26: #include "hash.h"
                     27: #include "thread.h"
                     28: 
                     29: #include "bgpd/bgpd.h"
                     30: #include "bgpd/bgp_table.h"
                     31: #include "bgpd/bgp_route.h"
                     32: #include "bgpd/bgp_advertise.h"
                     33: #include "bgpd/bgp_attr.h"
                     34: #include "bgpd/bgp_aspath.h"
                     35: #include "bgpd/bgp_packet.h"
                     36: #include "bgpd/bgp_fsm.h"
                     37: #include "bgpd/bgp_mplsvpn.h"
                     38: 
                     39: /* BGP advertise attribute is used for pack same attribute update into
                     40:    one packet.  To do that we maintain attribute hash in struct
                     41:    peer.  */
                     42: static struct bgp_advertise_attr *
                     43: baa_new (void)
                     44: {
                     45:   return (struct bgp_advertise_attr *)
                     46:     XCALLOC (MTYPE_BGP_ADVERTISE_ATTR, sizeof (struct bgp_advertise_attr));
                     47: }
                     48: 
                     49: static void
                     50: baa_free (struct bgp_advertise_attr *baa)
                     51: {
                     52:   XFREE (MTYPE_BGP_ADVERTISE_ATTR, baa);
                     53: }
                     54: 
                     55: static void *
                     56: baa_hash_alloc (void *p)
                     57: {
                     58:   struct bgp_advertise_attr * ref = (struct bgp_advertise_attr *) p;
                     59:   struct bgp_advertise_attr *baa;
                     60: 
                     61:   baa = baa_new ();
                     62:   baa->attr = ref->attr;
                     63:   return baa;
                     64: }
                     65: 
                     66: static unsigned int
                     67: baa_hash_key (void *p)
                     68: {
                     69:   struct bgp_advertise_attr * baa = (struct bgp_advertise_attr *) p;
                     70: 
                     71:   return attrhash_key_make (baa->attr);
                     72: }
                     73: 
                     74: static int
                     75: baa_hash_cmp (const void *p1, const void *p2)
                     76: {
                     77:   const struct bgp_advertise_attr * baa1 = p1;
                     78:   const struct bgp_advertise_attr * baa2 = p2;
                     79: 
                     80:   return attrhash_cmp (baa1->attr, baa2->attr);
                     81: }
                     82: 
                     83: /* BGP update and withdraw information is stored in BGP advertise
                     84:    structure.  This structure is referred from BGP adjacency
                     85:    information.  */
                     86: static struct bgp_advertise *
                     87: bgp_advertise_new (void)
                     88: {
                     89:   return (struct bgp_advertise *) 
                     90:     XCALLOC (MTYPE_BGP_ADVERTISE, sizeof (struct bgp_advertise));
                     91: }
                     92: 
                     93: static void
                     94: bgp_advertise_free (struct bgp_advertise *adv)
                     95: {
                     96:   if (adv->binfo)
                     97:     bgp_info_unlock (adv->binfo); /* bgp_advertise bgp_info reference */
                     98:   XFREE (MTYPE_BGP_ADVERTISE, adv);
                     99: }
                    100: 
                    101: static void
                    102: bgp_advertise_add (struct bgp_advertise_attr *baa,
                    103:                   struct bgp_advertise *adv)
                    104: {
                    105:   adv->next = baa->adv;
                    106:   if (baa->adv)
                    107:     baa->adv->prev = adv;
                    108:   baa->adv = adv;
                    109: }
                    110: 
                    111: static void
                    112: bgp_advertise_delete (struct bgp_advertise_attr *baa,
                    113:                      struct bgp_advertise *adv)
                    114: {
                    115:   if (adv->next)
                    116:     adv->next->prev = adv->prev;
                    117:   if (adv->prev)
                    118:     adv->prev->next = adv->next;
                    119:   else
                    120:     baa->adv = adv->next;
                    121: }
                    122: 
                    123: static struct bgp_advertise_attr *
                    124: bgp_advertise_intern (struct hash *hash, struct attr *attr)
                    125: {
                    126:   struct bgp_advertise_attr ref;
                    127:   struct bgp_advertise_attr *baa;
                    128: 
                    129:   ref.attr = bgp_attr_intern (attr);
                    130:   baa = (struct bgp_advertise_attr *) hash_get (hash, &ref, baa_hash_alloc);
                    131:   baa->refcnt++;
                    132: 
                    133:   return baa;
                    134: }
                    135: 
                    136: static void
                    137: bgp_advertise_unintern (struct hash *hash, struct bgp_advertise_attr *baa)
                    138: {
                    139:   if (baa->refcnt)
                    140:     baa->refcnt--;
                    141: 
                    142:   if (baa->refcnt && baa->attr)
                    143:     bgp_attr_unintern (&baa->attr);
                    144:   else
                    145:     {
                    146:       if (baa->attr)
                    147:        {
                    148:          hash_release (hash, baa);
                    149:          bgp_attr_unintern (&baa->attr);
                    150:        }
                    151:       baa_free (baa);
                    152:     }
                    153: }
                    154: 
                    155: /* BGP adjacency keeps minimal advertisement information.  */
                    156: static void
                    157: bgp_adj_out_free (struct bgp_adj_out *adj)
                    158: {
                    159:   peer_unlock (adj->peer); /* adj_out peer reference */
                    160:   XFREE (MTYPE_BGP_ADJ_OUT, adj);
                    161: }
                    162: 
                    163: int
                    164: bgp_adj_out_lookup (struct peer *peer, struct prefix *p,
                    165:                    afi_t afi, safi_t safi, struct bgp_node *rn)
                    166: {
                    167:   struct bgp_adj_out *adj;
                    168: 
                    169:   for (adj = rn->adj_out; adj; adj = adj->next)
                    170:     if (adj->peer == peer)
                    171:       break;
                    172: 
                    173:   if (! adj)
                    174:     return 0;
                    175: 
                    176:   return (adj->adv 
                    177:          ? (adj->adv->baa ? 1 : 0)
                    178:          : (adj->attr ? 1 : 0));
                    179: }
                    180: 
                    181: struct bgp_advertise *
                    182: bgp_advertise_clean (struct peer *peer, struct bgp_adj_out *adj,
                    183:                     afi_t afi, safi_t safi)
                    184: {
                    185:   struct bgp_advertise *adv;
                    186:   struct bgp_advertise_attr *baa;
                    187:   struct bgp_advertise *next;
                    188: 
                    189:   adv = adj->adv;
                    190:   baa = adv->baa;
                    191:   next = NULL;
                    192: 
                    193:   if (baa)
                    194:     {
                    195:       /* Unlink myself from advertise attribute FIFO.  */
                    196:       bgp_advertise_delete (baa, adv);
                    197: 
                    198:       /* Fetch next advertise candidate. */
                    199:       next = baa->adv;
                    200: 
                    201:       /* Unintern BGP advertise attribute.  */
                    202:       bgp_advertise_unintern (peer->hash[afi][safi], baa);
                    203:     }
                    204: 
                    205:   /* Unlink myself from advertisement FIFO.  */
                    206:   FIFO_DEL (adv);
                    207: 
                    208:   /* Free memory.  */
                    209:   bgp_advertise_free (adj->adv);
                    210:   adj->adv = NULL;
                    211: 
                    212:   return next;
                    213: }
                    214: 
                    215: void
                    216: bgp_adj_out_set (struct bgp_node *rn, struct peer *peer, struct prefix *p,
                    217:                 struct attr *attr, afi_t afi, safi_t safi,
                    218:                 struct bgp_info *binfo)
                    219: {
                    220:   struct bgp_adj_out *adj = NULL;
                    221:   struct bgp_advertise *adv;
                    222: 
                    223:   if (DISABLE_BGP_ANNOUNCE)
                    224:     return;
                    225: 
                    226:   /* Look for adjacency information. */
                    227:   if (rn)
                    228:     {
                    229:       for (adj = rn->adj_out; adj; adj = adj->next)
                    230:        if (adj->peer == peer)
                    231:          break;
                    232:     }
                    233: 
                    234:   if (! adj)
                    235:     {
                    236:       adj = XCALLOC (MTYPE_BGP_ADJ_OUT, sizeof (struct bgp_adj_out));
                    237:       adj->peer = peer_lock (peer); /* adj_out peer reference */
                    238:       
                    239:       if (rn)
                    240:         {
                    241:           BGP_ADJ_OUT_ADD (rn, adj);
                    242:           bgp_lock_node (rn);
                    243:         }
                    244:     }
                    245: 
                    246:   if (adj->adv)
                    247:     bgp_advertise_clean (peer, adj, afi, safi);
                    248:   
                    249:   adj->adv = bgp_advertise_new ();
                    250: 
                    251:   adv = adj->adv;
                    252:   adv->rn = rn;
                    253:   
                    254:   assert (adv->binfo == NULL);
                    255:   adv->binfo = bgp_info_lock (binfo); /* bgp_info adj_out reference */
                    256:   
                    257:   if (attr)
                    258:     adv->baa = bgp_advertise_intern (peer->hash[afi][safi], attr);
                    259:   else
                    260:     adv->baa = baa_new ();
                    261:   adv->adj = adj;
                    262: 
                    263:   /* Add new advertisement to advertisement attribute list. */
                    264:   bgp_advertise_add (adv->baa, adv);
                    265: 
                    266:   FIFO_ADD (&peer->sync[afi][safi]->update, &adv->fifo);
                    267: }
                    268: 
                    269: void
                    270: bgp_adj_out_unset (struct bgp_node *rn, struct peer *peer, struct prefix *p, 
                    271:                   afi_t afi, safi_t safi)
                    272: {
                    273:   struct bgp_adj_out *adj;
                    274:   struct bgp_advertise *adv;
                    275: 
                    276:   if (DISABLE_BGP_ANNOUNCE)
                    277:     return;
                    278: 
                    279:   /* Lookup existing adjacency, if it is not there return immediately.  */
                    280:   for (adj = rn->adj_out; adj; adj = adj->next)
                    281:     if (adj->peer == peer)
                    282:       break;
                    283: 
                    284:   if (! adj)
                    285:     return;
                    286: 
                    287:   /* Clearn up previous advertisement.  */
                    288:   if (adj->adv)
                    289:     bgp_advertise_clean (peer, adj, afi, safi);
                    290: 
                    291:   if (adj->attr)
                    292:     {
                    293:       /* We need advertisement structure.  */
                    294:       adj->adv = bgp_advertise_new ();
                    295:       adv = adj->adv;
                    296:       adv->rn = rn;
                    297:       adv->adj = adj;
                    298: 
                    299:       /* Add to synchronization entry for withdraw announcement.  */
                    300:       FIFO_ADD (&peer->sync[afi][safi]->withdraw, &adv->fifo);
                    301: 
                    302:       /* Schedule packet write. */
                    303:       BGP_WRITE_ON (peer->t_write, bgp_write, peer->fd);
                    304:     }
                    305:   else
                    306:     {
                    307:       /* Remove myself from adjacency. */
                    308:       BGP_ADJ_OUT_DEL (rn, adj);
                    309:       
                    310:       /* Free allocated information.  */
                    311:       bgp_adj_out_free (adj);
                    312: 
                    313:       bgp_unlock_node (rn);
                    314:     }
                    315: }
                    316: 
                    317: void
                    318: bgp_adj_out_remove (struct bgp_node *rn, struct bgp_adj_out *adj, 
                    319:                    struct peer *peer, afi_t afi, safi_t safi)
                    320: {
                    321:   if (adj->attr)
                    322:     bgp_attr_unintern (&adj->attr);
                    323: 
                    324:   if (adj->adv)
                    325:     bgp_advertise_clean (peer, adj, afi, safi);
                    326: 
                    327:   BGP_ADJ_OUT_DEL (rn, adj);
                    328:   bgp_adj_out_free (adj);
                    329: }
                    330: 
                    331: void
                    332: bgp_adj_in_set (struct bgp_node *rn, struct peer *peer, struct attr *attr)
                    333: {
                    334:   struct bgp_adj_in *adj;
                    335: 
                    336:   for (adj = rn->adj_in; adj; adj = adj->next)
                    337:     {
                    338:       if (adj->peer == peer)
                    339:        {
                    340:          if (adj->attr != attr)
                    341:            {
                    342:              bgp_attr_unintern (&adj->attr);
                    343:              adj->attr = bgp_attr_intern (attr);
                    344:            }
                    345:          return;
                    346:        }
                    347:     }
                    348:   adj = XCALLOC (MTYPE_BGP_ADJ_IN, sizeof (struct bgp_adj_in));
                    349:   adj->peer = peer_lock (peer); /* adj_in peer reference */
                    350:   adj->attr = bgp_attr_intern (attr);
                    351:   BGP_ADJ_IN_ADD (rn, adj);
                    352:   bgp_lock_node (rn);
                    353: }
                    354: 
                    355: void
                    356: bgp_adj_in_remove (struct bgp_node *rn, struct bgp_adj_in *bai)
                    357: {
                    358:   bgp_attr_unintern (&bai->attr);
                    359:   BGP_ADJ_IN_DEL (rn, bai);
                    360:   peer_unlock (bai->peer); /* adj_in peer reference */
                    361:   XFREE (MTYPE_BGP_ADJ_IN, bai);
                    362: }
                    363: 
                    364: void
                    365: bgp_adj_in_unset (struct bgp_node *rn, struct peer *peer)
                    366: {
                    367:   struct bgp_adj_in *adj;
                    368: 
                    369:   for (adj = rn->adj_in; adj; adj = adj->next)
                    370:     if (adj->peer == peer)
                    371:       break;
                    372: 
                    373:   if (! adj)
                    374:     return;
                    375: 
                    376:   bgp_adj_in_remove (rn, adj);
                    377:   bgp_unlock_node (rn);
                    378: }
                    379: 
                    380: void
                    381: bgp_sync_init (struct peer *peer)
                    382: {
                    383:   afi_t afi;
                    384:   safi_t safi;
                    385:   struct bgp_synchronize *sync;
                    386: 
                    387:   for (afi = AFI_IP; afi < AFI_MAX; afi++)
                    388:     for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
                    389:       {
                    390:        sync = XCALLOC (MTYPE_BGP_SYNCHRONISE, 
                    391:                        sizeof (struct bgp_synchronize));
                    392:        FIFO_INIT (&sync->update);
                    393:        FIFO_INIT (&sync->withdraw);
                    394:        FIFO_INIT (&sync->withdraw_low);
                    395:        peer->sync[afi][safi] = sync;
                    396:        peer->hash[afi][safi] = hash_create (baa_hash_key, baa_hash_cmp);
                    397:       }
                    398: }
                    399: 
                    400: void
                    401: bgp_sync_delete (struct peer *peer)
                    402: {
                    403:   afi_t afi;
                    404:   safi_t safi;
                    405: 
                    406:   for (afi = AFI_IP; afi < AFI_MAX; afi++)
                    407:     for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++)
                    408:       {
                    409:        if (peer->sync[afi][safi])
                    410:          XFREE (MTYPE_BGP_SYNCHRONISE, peer->sync[afi][safi]);
                    411:        peer->sync[afi][safi] = NULL;
                    412:        
                    413:        if (peer->hash[afi][safi])
                    414:          hash_free (peer->hash[afi][safi]);
                    415:        peer->hash[afi][safi] = NULL;
                    416:       }
                    417: }

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