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https://gitlab.labs.nic.cz/labs/bird.git
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345 lines
7.3 KiB
C
345 lines
7.3 KiB
C
/*
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* BIRD -- OSPF
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*
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* (c) 1999 Ondrej Filip <feela@network.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#include "ospf.h"
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void
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neigh_chstate(struct ospf_neighbor *n, u8 state)
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{
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struct ospf_iface *ifa;
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struct proto *p;
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if(n->state!=state)
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{
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ifa=n->ifa;
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p=(struct proto *)(ifa->proto);
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debug("%s: Neigbor '%u' changes state from %u to %u.\n", p->name, n->rid,
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n->state, state);
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n->state=state;
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}
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}
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struct ospf_neighbor *
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electbdr(list nl)
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{
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struct ospf_neighbor *neigh,*n1,*n2;
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n1=NULL;
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n2=NULL;
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WALK_LIST (neigh, nl) /* First try those decl. themselves */
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{
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if(neigh->state>=NEIGHBOR_2WAY) /* Higher than 2WAY */
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if(neigh->priority>0) /* Eligible */
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if(neigh->rid!=neigh->dr) /* And not declaring itself DR */
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{
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if(neigh->rid==neigh->bdr) /* Declaring BDR */
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{
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if(n1!=NULL)
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{
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if(neigh->priority>n1->priority) n1=neigh;
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else if(neigh->priority==n1->priority)
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if(neigh->rid>n1->rid) n1=neigh;
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}
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else
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{
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n1=neigh;
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}
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}
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else /* And NOT declaring BDR */
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{
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if(n2!=NULL)
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{
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if(neigh->priority>n2->priority) n2=neigh;
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else if(neigh->priority==n2->priority)
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if(neigh->rid>n2->rid) n2=neigh;
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}
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else
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{
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n2=neigh;
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}
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}
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}
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}
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if(n1==NULL) n1=n2;
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return(n1);
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}
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struct ospf_neighbor *
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electdr(list nl)
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{
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struct ospf_neighbor *neigh,*n;
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n=NULL;
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WALK_LIST (neigh, nl) /* And now DR */
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{
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if(neigh->state>=NEIGHBOR_2WAY) /* Higher than 2WAY */
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if(neigh->priority>0) /* Eligible */
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if(neigh->rid==neigh->dr) /* And declaring itself DR */
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{
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if(n!=NULL)
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{
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if(neigh->priority>n->priority) n=neigh;
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else if(neigh->priority==n->priority)
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if(neigh->rid>n->rid) n=neigh;
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}
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else
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{
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n=neigh;
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}
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}
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}
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return(n);
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}
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int
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can_do_adj(struct ospf_neighbor *n)
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{
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struct ospf_iface *ifa;
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struct proto *p;
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int i;
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ifa=n->ifa;
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p=(struct proto *)(ifa->proto);
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i=0;
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switch(ifa->type)
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{
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case OSPF_IT_PTP:
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case OSPF_IT_VLINK:
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i=1;
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break;
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case OSPF_IT_BCAST:
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case OSPF_IT_NBMA:
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switch(ifa->state)
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{
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case OSPF_IS_DOWN:
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die("%s: Iface %s in down state?", p->name, ifa->iface->name);
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break;
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case OSPF_IS_WAITING:
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DBG("%s: Neighbor? on iface %s\n",p->name, ifa->iface->name);
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break;
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case OSPF_IS_DROTHER:
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if(((n->rid==ifa->drid) || (n->rid==ifa->bdrid))
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&& (n->state==NEIGHBOR_2WAY)) i=1;
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break;
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case OSPF_IS_PTP:
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case OSPF_IS_BACKUP:
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case OSPF_IS_DR:
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if(n->state==NEIGHBOR_2WAY) i=1;
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break;
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default:
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die("%s: Iface %s in unknown state?",p->name, ifa->iface->name);
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break;
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}
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break;
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default:
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die("%s: Iface %s is unknown type?",p->name, ifa->iface->name);
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break;
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}
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DBG("%s: Iface %s can_do_adj=%d\n",p->name, ifa->iface->name,i);
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return i;
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}
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/* Try to build neighbor adjacency (if does not exists) */
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void
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tryadj(struct ospf_neighbor *n, struct proto *p)
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{
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DBG("%s: Going to build adjacency.\n", p->name);
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neigh_chstate(n,NEIGHBOR_EXSTART);
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if(n->adj==0) /* First time adjacency */
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{
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n->dds=random_u32();
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}
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n->dds++;
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n->myimms=(DBDES_MS | DBDES_M | DBDES_I );
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tm_start(n->ifa->rxmt_timer,1); /* Or some other number ? */
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}
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void
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ospf_neigh_sm(struct ospf_neighbor *n, int event)
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/* Interface state machine */
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{
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struct proto *p;
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p=(struct proto *)(n->ifa->proto);
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switch(event)
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{
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case INM_START:
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neigh_chstate(n,NEIGHBOR_ATTEMPT);
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/* FIXME No NBMA now */
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break;
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case INM_HELLOREC:
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switch(n->state)
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{
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case NEIGHBOR_ATTEMPT:
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case NEIGHBOR_DOWN:
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neigh_chstate(n,NEIGHBOR_INIT);
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default:
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restart_inactim(n);
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break;
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}
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break;
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case INM_2WAYREC:
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if(n->state==NEIGHBOR_INIT)
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{
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/* Can In build adjacency? */
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neigh_chstate(n,NEIGHBOR_2WAY);
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if(can_do_adj(n))
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{
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neigh_chstate(n,NEIGHBOR_EXSTART);
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tryadj(n,p);
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}
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}
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break;
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case INM_NEGDONE:
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if(n->state==NEIGHBOR_EXSTART)
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{
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neigh_chstate(n,NEIGHBOR_EXCHANGE);
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/* FIXME Go on... */
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}
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break;
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case INM_EXDONE:
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break;
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case INM_LOADDONE:
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break;
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case INM_ADJOK:
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switch(n->state)
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{
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case NEIGHBOR_2WAY:
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/* Can In build adjacency? */
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if(can_do_adj(n))
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{
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neigh_chstate(n,NEIGHBOR_EXSTART);
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tryadj(n,p);
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}
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break;
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default:
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if(n->state>=NEIGHBOR_EXSTART)
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if(!can_do_adj(n))
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{
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neigh_chstate(n,NEIGHBOR_2WAY);
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/* FIXME Stop timers, kill database... */
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}
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break;
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}
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break;
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case INM_SEQMIS:
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case INM_BADLSREQ:
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debug("%s: Bad LS req!\n", p->name);
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if(n->state>=NEIGHBOR_EXCHANGE)
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{
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neigh_chstate(n,NEIGHBOR_EXSTART);
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/* Go on....*/
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}
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break;
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case INM_KILLNBR:
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case INM_LLDOWN:
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case INM_INACTTIM:
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neigh_chstate(n,NEIGHBOR_DOWN);
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break;
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case INM_1WAYREC:
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if(n->state>=NEIGHBOR_2WAY)
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{
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neigh_chstate(n,NEIGHBOR_DOWN);
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}
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break;
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default:
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die("%s: INM - Unknown event?",p->name);
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break;
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}
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}
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void
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bdr_election(struct ospf_iface *ifa, struct proto *p)
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{
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struct ospf_neighbor *neigh,*ndr,*nbdr,me;
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u32 myid, ndrid, nbdrid;
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int doadj;
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p=(struct proto *)(ifa->proto);
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DBG("%s: (B)DR election.\n",p->name);
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myid=p->cf->global->router_id;
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me.state=NEIGHBOR_2WAY;
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me.rid=myid;
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me.priority=ifa->priority;
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me.dr=ifa->drid;
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me.bdr=ifa->bdrid;
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add_tail(&ifa->neigh_list, NODE &me);
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nbdr=electbdr(ifa->neigh_list);
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ndr=electdr(ifa->neigh_list);
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if(ndr==NULL) ndr=nbdr;
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if(((ifa->drid==myid) && (ndr->rid!=myid))
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|| ((ifa->drid!=myid) && (ndr->rid==myid))
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|| ((ifa->bdrid==myid) && (nbdr->rid!=myid))
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|| ((ifa->bdrid!=myid) && (nbdr->rid==myid)))
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{
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if(ndr==NULL) ifa->drid=me.dr=0;
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else ifa->drid=me.dr=ndr->rid;
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if(nbdr==NULL) ifa->bdrid=me.bdr=0;
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else ifa->bdrid=me.bdr=nbdr->rid;
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nbdr=electbdr(ifa->neigh_list);
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ndr=electdr(ifa->neigh_list);
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}
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if(ndr==NULL) ifa->drid=0;
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if(ndr==NULL) ndrid=0;
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else ndrid=ndr->rid;
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if(nbdr==NULL) nbdrid=0;
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else nbdrid=nbdr->rid;
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doadj=0;
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if((ifa->drid!=ndrid) || (ifa->bdrid!=nbdrid)) doadj=1;
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ifa->drid=ndrid;
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ifa->bdrid=nbdrid;
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DBG("%s: DR=%u, BDR=%u\n",p->name, ifa->drid, ifa->bdrid);
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if(myid==ifa->drid) iface_chstate(ifa, OSPF_IS_DR);
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else
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{
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if(myid==ifa->bdrid) iface_chstate(ifa, OSPF_IS_BACKUP);
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else iface_chstate(ifa, OSPF_IS_DROTHER);
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}
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rem_node(NODE &me);
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if(doadj)
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{
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WALK_LIST (neigh, ifa->neigh_list)
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{
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ospf_neigh_sm(neigh, INM_ADJOK);
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}
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}
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}
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struct ospf_neighbor *
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find_neigh(struct ospf_iface *ifa, u32 rid)
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{
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struct ospf_neighbor *n;
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WALK_LIST (n, ifa->neigh_list)
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if(n->rid == rid)
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return n;
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return NULL;
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}
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