proto/ospf/dbdes.c

   1 /*
   2  *      BIRD -- OSPF
   3  *
   4  *      (c) 1999 - 2000 Ondrej Filip <feela@network.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #include "ospf.h"
  10
  11 /**
  12  * ospf_dbdes_tx - transmit database description packet
  13  * @n: neighbor
  14  *
  15  * Sending of a database description packet is described in 10.6 of RFC 2328.
  16  * Reception of each packet is acknowledged in the sequence number of another.
  17  * When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor
  18  * does not reply, I don't create a new packet but just send the content
  19  * of the buffer.
  20  */
  21 void
  22 ospf_dbdes_tx(struct ospf_neighbor *n)
  23 {
  24   struct ospf_dbdes_packet *pkt;
  25   struct ospf_packet *op;
  26   struct ospf_iface *ifa=n->ifa;
  27   struct ospf_area *oa=ifa->oa;
  28   u16 length;
  29   struct proto *p;
  30   u16 i,j;
  31   u8 *aa,*bb;
  32
  33   if((oa->rt==NULL)||(EMPTY_LIST(oa->lsal))) originate_rt_lsa(oa);
  34     oa->origrt=0;
  35
  36
  37   p=(struct proto *)(ifa->proto);
  38
  39   switch(n->state)
  40   {
  41     case NEIGHBOR_EXSTART:              /* Send empty packets */
  42       n->myimms.bit.i=1;
  43       pkt=(struct ospf_dbdes_packet *)(ifa->ip_sk->tbuf);
  44       op=(struct ospf_packet *)pkt;
  45       fill_ospf_pkt_hdr(ifa, pkt, DBDES_P);
  46       pkt->iface_mtu=htons(ifa->iface->mtu);    /* FIXME NOT for VLINK! */
  47       pkt->options= ifa->options;
  48       pkt->imms=n->myimms;
  49       pkt->ddseq=htonl(n->dds);
  50       length=sizeof(struct ospf_dbdes_packet);
  51       op->length=htons(length);
  52       ospf_pkt_finalize(ifa, op);
  53       sk_send_to(ifa->ip_sk,length, n->ip, OSPF_PROTO);
  54       OSPF_TRACE(D_PACKETS, "DB_DES (I) sent to %I via %s.", n->ip,
  55         ifa->iface->name);
  56       break;
  57
  58     case NEIGHBOR_EXCHANGE:
  59       n->myimms.bit.i=0;
  60
  61       if(((n->myimms.bit.ms) && (n->dds==n->ddr+1)) ||
  62          ((!(n->myimms.bit.ms)) && (n->dds==n->ddr)))
  63       {
  64         snode *sn;                      /* Send next */
  65         struct ospf_lsa_header *lsa;
  66
  67         pkt=n->ldbdes;
  68         op=(struct ospf_packet *)pkt;
  69
  70         fill_ospf_pkt_hdr(ifa, pkt, DBDES_P);
  71         pkt->iface_mtu=htons(ifa->iface->mtu);
  72         pkt->options= ifa->options;
  73         pkt->ddseq=htonl(n->dds);
  74
  75         j=i=(ifa->iface->mtu-sizeof(struct ospf_dbdes_packet)-SIPH)/
  76                 sizeof(struct ospf_lsa_header); /* Number of possible lsaheaders to send */
  77         lsa=(n->ldbdes+sizeof(struct ospf_dbdes_packet));
  78
  79         if(n->myimms.bit.m)
  80         {
  81           sn=s_get(&(n->dbsi));
  82
  83           DBG("Number of LSA: %d\n", j);
  84           for(;i>0;i--)
  85           {
  86             struct top_hash_entry *en;
  87
  88             en=(struct top_hash_entry *)sn;
  89             htonlsah(&(en->lsa), lsa);
  90             DBG("Working on: %d\n", i);
  91             DBG("\tX%01x %-1I %-1I %p\n", en->lsa.type, en->lsa.id,
  92               en->lsa.rt, en->lsa_body);
  93
  94             if(sn==STAIL(n->ifa->oa->lsal))
  95             {
  96               i--;
  97               break;    /* Should set some flag? */
  98             }
  99             sn=sn->next;
 100             lsa++;
 101           }
 102
 103           if(sn==STAIL(n->ifa->oa->lsal))
 104           {
 105             DBG("Number of LSA NOT sent: %d\n", i);
 106             DBG("M bit unset.\n");
 107             n->myimms.bit.m=0;  /* Unset more bit */
 108           }
 109           else s_put(&(n->dbsi),sn);
 110         }
 111
 112         pkt->imms.byte=n->myimms.byte;
 113
 114         length=(j-i)*sizeof(struct ospf_lsa_header)+
 115                 sizeof(struct ospf_dbdes_packet);
 116         op->length=htons(length);
 117
 118         ospf_pkt_finalize(ifa, op);
 119         DBG("%s: DB_DES (M) prepared for %I.\n", p->name, n->ip);
 120       }
 121
 122     case NEIGHBOR_LOADING:
 123     case NEIGHBOR_FULL:
 124       aa=ifa->ip_sk->tbuf;
 125       bb=n->ldbdes;
 126       op=n->ldbdes;
 127       length=ntohs(op->length);
 128
 129       for(i=0; i<length; i++)
 130       {
 131         *(aa+i)=*(bb+i);        /* Copy last sent packet again */
 132       }
 133
 134       sk_send_to(ifa->ip_sk,length, n->ip, OSPF_PROTO);
 135       OSPF_TRACE(D_PACKETS, "DB_DES (M) sent to %I via %s.", n->ip,
 136         ifa->iface->name);
 137       if(! n->myimms.bit.ms)
 138       {
 139         if((n->myimms.bit.m==0) && (n->imms.bit.m==0) &&
 140           (n->state==NEIGHBOR_EXCHANGE))
 141         {
 142           ospf_neigh_sm(n, INM_EXDONE);
 143         }
 144       }
 145       break;
 146
 147     default:                            /* Ignore it */
 148       bug("Bug in dbdes sending");
 149       break;
 150   }
 151 }
 152
 153 void
 154 ospf_dbdes_reqladd(struct ospf_dbdes_packet *ps, struct proto *p,
 155   struct ospf_neighbor *n)
 156 {
 157   struct ospf_lsa_header *plsa,lsa;
 158   struct top_hash_entry *he,*sn;
 159   struct top_graph *gr;
 160   struct ospf_packet *op;
 161   int i,j;
 162
 163   gr=n->ifa->oa->gr;
 164   op=(struct ospf_packet *)ps;
 165
 166   plsa=(void *)(ps+1);
 167
 168   j=(ntohs(op->length)-sizeof(struct ospf_dbdes_packet))/
 169     sizeof( struct ospf_lsa_header);
 170
 171   for(i=0;i<j;i++)
 172   {
 173     ntohlsah(plsa+i, &lsa);
 174     if(((he=ospf_hash_find(gr,lsa.id,lsa.rt,lsa.type))==NULL)||
 175       (lsa_comp(&lsa, &(he->lsa))==1))
 176     {
 177       /* Is this condition necessary? */
 178       if(ospf_hash_find(n->lsrqh,lsa.id,lsa.rt,lsa.type)==NULL)
 179       {
 180         sn=ospf_hash_get(n->lsrqh,lsa.id,lsa.rt,lsa.type);
 181         ntohlsah(plsa+i, &(sn->lsa));
 182         s_add_tail(&(n->lsrql), SNODE sn);
 183       }
 184     }
 185   }
 186 }
 187
 188 void
 189 ospf_dbdes_rx(struct ospf_dbdes_packet *ps, struct proto *p,
 190   struct ospf_iface *ifa, u16 size)
 191 {
 192   u32 nrid, myrid;
 193   struct ospf_neighbor *n;
 194
 195   nrid=ntohl(((struct ospf_packet *)ps)->routerid);
 196
 197   myrid=p->cf->global->router_id;
 198
 199   if((n=find_neigh(ifa, nrid))==NULL)
 200   {
 201     OSPF_TRACE(D_PACKETS, "Received dbdes from unknown neigbor! %I.",
 202       nrid);
 203     return ;
 204   }
 205
 206   if(ifa->iface->mtu<size)
 207   {
 208     OSPF_TRACE(D_PACKETS, "Received dbdes larger than MTU from %I!", n->ip);
 209     return ;
 210   }
 211
 212   OSPF_TRACE(D_PACKETS, "Received dbdes from %I via %s.", n->ip,
 213     ifa->iface->name);
 214   ospf_neigh_sm(n, INM_HELLOREC);
 215
 216   switch(n->state)
 217   {
 218     case NEIGHBOR_DOWN:
 219     case NEIGHBOR_ATTEMPT:
 220     case NEIGHBOR_2WAY:
 221         return;
 222       break;
 223     case NEIGHBOR_INIT:
 224         ospf_neigh_sm(n, INM_2WAYREC);
 225         if(n->state!=NEIGHBOR_EXSTART) return;
 226     case NEIGHBOR_EXSTART:
 227         if((ps->imms.bit.m && ps->imms.bit.ms && ps->imms.bit.i)
 228           && (n->rid > myrid) &&
 229           (size == sizeof(struct ospf_dbdes_packet)))
 230         {
 231           /* I'm slave! */
 232           n->dds=ntohl(ps->ddseq);
 233           n->ddr=ntohl(ps->ddseq);
 234           n->options=ps->options;
 235           n->myimms.bit.ms=0;
 236           n->imms.byte=ps->imms.byte;
 237           OSPF_TRACE(D_PACKETS, "I'm slave to %I.", n->ip);
 238           ospf_neigh_sm(n, INM_NEGDONE);
 239           ospf_dbdes_tx(n);
 240           break;
 241         }
 242         else
 243         {
 244           if(((ps->imms.bit.i==0) && (ps->imms.bit.ms==0)) &&
 245             (n->rid < myrid) && (n->dds == ntohl(ps->ddseq)))
 246           {
 247             /* I'm master! */
 248             n->options=ps->options;
 249             n->ddr=ntohl(ps->ddseq)-1;
 250             n->imms.byte=ps->imms.byte;
 251             OSPF_TRACE(D_PACKETS, "I'm master to %I.", n->ip);
 252             ospf_neigh_sm(n, INM_NEGDONE);
 253           }
 254           else
 255           {
 256             DBG("%s: Nothing happend to %I (imms=%u)\n", p->name, n->ip,
 257               ps->imms.byte);
 258             break;
 259           }
 260         }
 261         if(ps->imms.bit.i) break;
 262     case NEIGHBOR_EXCHANGE:
 263         if((ps->imms.byte==n->imms.byte) && (ps->options==n->options) &&
 264           (ntohl(ps->ddseq)==n->ddr))
 265         {
 266           /* Duplicate packet */
 267           OSPF_TRACE(D_PACKETS, "Received duplicate dbdes from %I.", n->ip);
 268           if(n->imms.bit.ms==0)
 269           {
 270             ospf_dbdes_tx(n);
 271           }
 272           return;
 273         }
 274
 275         n->ddr=ntohl(ps->ddseq);
 276
 277         if(ps->imms.bit.ms!=n->imms.bit.ms) /* M/S bit differs */
 278         {
 279           log("SEQMIS-BIT-MS\n");
 280           ospf_neigh_sm(n, INM_SEQMIS);
 281           break;
 282         }
 283
 284         if(ps->imms.bit.i)      /* I bit is set */
 285         {
 286           log("SEQMIS-BIT-I\n");
 287           ospf_neigh_sm(n, INM_SEQMIS);
 288           break;
 289         }
 290
 291         n->imms.byte=ps->imms.byte;
 292
 293         if(ps->options!=n->options)     /* Options differs */
 294         {
 295           log("SEQMIS-OPT\n");
 296           ospf_neigh_sm(n, INM_SEQMIS);
 297           break;
 298         }
 299
 300         if(n->myimms.bit.ms)
 301         {
 302           if(ntohl(ps->ddseq)!=n->dds)          /* MASTER */
 303           {
 304             log("SEQMIS-MASTER\n");
 305             ospf_neigh_sm(n, INM_SEQMIS);
 306             break;
 307           }
 308           n->dds++;
 309           DBG("Incrementing dds\n");
 310           ospf_dbdes_reqladd(ps,p,n);
 311           if((n->myimms.bit.m==0) && (ps->imms.bit.m==0))
 312           {
 313             ospf_neigh_sm(n, INM_EXDONE);
 314           }
 315           else
 316           {
 317             ospf_dbdes_tx(n);
 318           }
 319
 320         }
 321         else
 322         {
 323           if(ntohl(ps->ddseq)!=(n->dds+1))      /* SLAVE */
 324           {
 325             log("SEQMIS-SLAVE\n");
 326             ospf_neigh_sm(n, INM_SEQMIS);
 327             break;
 328           }
 329           n->ddr=ntohl(ps->ddseq);
 330           n->dds=ntohl(ps->ddseq);
 331           ospf_dbdes_reqladd(ps,p,n);
 332           ospf_dbdes_tx(n);
 333         }
 334
 335       break;
 336     case NEIGHBOR_LOADING:
 337     case NEIGHBOR_FULL:
 338         if((ps->imms.byte==n->imms.byte) && (ps->options==n->options) &&
 339           (ntohl(ps->ddseq)==n->ddr)) /* Only duplicate are accepted */
 340         {
 341           OSPF_TRACE(D_PACKETS, "Received duplicate dbdes from %I.",n->ip);
 342           return;
 343         }
 344         else
 345         {
 346           log("SEQMIS-FULL\n");
 347           ospf_neigh_sm(n, INM_SEQMIS);
 348         }
 349       break;
 350     defaut:
 351       bug("%s: Received dbdes from %I in undefined state.", p->name, n->ip);
 352       break;
 353    }
 354 }
 355