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