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bird/proto/ospf/neighbor.c

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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"
char *ospf_ns[]={"down", "attempt", "init", "2way", "exstart", "exchange",
"loading", "full"};
const char *ospf_inm[]={ "hello received", "neighbor start", "2-way received",
"negotiation done", "exstart done", "bad ls request", "load done",
"adjacency ok?", "sequence mismatch", "1-way received", "kill neighbor",
"inactivity timer", "line down" };
void
neigh_chstate(struct ospf_neighbor *n, u8 state)
{
struct ospf_iface *ifa;
struct proto *p;
u8 oldstate;
oldstate=n->state;
if(oldstate!=state)
{
ifa=n->ifa;
n->state=state;
if(oldstate==NEIGHBOR_FULL) /* Decrease number of adjacencies */
{
ifa->fadj--;
n->state=state;
originate_rt_lsa(ifa->oa,ifa->oa->po);
originate_net_lsa(ifa,ifa->oa->po);
}
p=(struct proto *)(ifa->proto);
debug("%s: Neighbor %I changes state from \"%s\" to \"%s\".\n",
p->name, n->ip, ospf_ns[oldstate], ospf_ns[state]);
if(state==NEIGHBOR_FULL) /* Increase number of adjacencies */
{
ifa->fadj++;
originate_rt_lsa(n->ifa->oa,n->ifa->oa->po);
originate_net_lsa(ifa,ifa->oa->po);
}
if(oldstate>=NEIGHBOR_EXSTART && state<NEIGHBOR_EXSTART)
{
tm_stop(n->rxmt_timer);
/* Stop RXMT timers */
}
if(state==NEIGHBOR_EXSTART)
{
if(n->adj==0) /* First time adjacency */
{
n->dds=random_u32();
}
n->dds++;
n->myimms.byte=0;
n->myimms.bit.ms=1;
n->myimms.bit.m=1;
n->myimms.bit.i=1;
tm_start(n->rxmt_timer,1); /* Or some other number ? */
}
if(state<NEIGHBOR_EXCHANGE) tm_stop(n->lsrr_timer);
}
}
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;
}
void
ospf_neigh_sm(struct ospf_neighbor *n, int event)
/* Interface state machine */
{
struct proto *p=(struct proto *)(n->ifa->proto);
struct proto_ospf *po=n->ifa->proto;
DBG("%s: Neighbor state machine for neighbor %I, event \"%s\".\n",
p->name, n->rid, ospf_inm[event]);
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_2WAY)
{
/* Can In build adjacency? */
neigh_chstate(n,NEIGHBOR_2WAY);
if(can_do_adj(n))
{
neigh_chstate(n,NEIGHBOR_EXSTART);
}
ospf_int_sm(n->ifa, ISM_NEICH);
}
break;
case INM_NEGDONE:
if(n->state==NEIGHBOR_EXSTART)
{
neigh_chstate(n,NEIGHBOR_EXCHANGE);
s_init_list(&(n->lsrql));
n->lsrqh=ospf_top_new(n->ifa->proto);
s_init_list(&(n->lsrtl));
n->lsrth=ospf_top_new(n->ifa->proto);
s_init(&(n->dbsi), &(n->ifa->oa->lsal));
s_init(&(n->lsrqi), &(n->lsrql));
s_init(&(n->lsrti), &(n->lsrtl));
tm_start(n->lsrr_timer,n->ifa->rxmtint);
tm_start(n->ackd_timer,n->ifa->rxmtint/2);
}
else die("NEGDONE and I'm not in EXSTART?\n");
break;
case INM_EXDONE:
neigh_chstate(n,NEIGHBOR_LOADING);
break;
case INM_LOADDONE:
neigh_chstate(n,NEIGHBOR_FULL);
break;
case INM_ADJOK:
switch(n->state)
{
case NEIGHBOR_2WAY:
/* Can In build adjacency? */
if(can_do_adj(n))
{
neigh_chstate(n,NEIGHBOR_EXSTART);
}
break;
default:
if(n->state>=NEIGHBOR_EXSTART)
if(!can_do_adj(n))
{
neigh_chstate(n,NEIGHBOR_2WAY);
}
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);
}
break;
case INM_KILLNBR:
case INM_LLDOWN:
case INM_INACTTIM:
neigh_chstate(n,NEIGHBOR_DOWN);
ospf_int_sm(n->ifa, ISM_NEICH);
break;
case INM_1WAYREC:
if(n->state>=NEIGHBOR_2WAY)
{
neigh_chstate(n,NEIGHBOR_DOWN);
ospf_int_sm(n->ifa, ISM_NEICH);
}
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,*tmp;
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;
if((tmp=find_neigh(ifa,ndrid))==NULL) die("Error i BDR election.\n");
ifa->drip=tmp->ip;
ifa->bdrid=nbdrid;
if((tmp=find_neigh(ifa,nbdrid))==NULL) die("Error i BDR election.\n");
ifa->bdrip=tmp->ip;
DBG("%s: DR=%I, BDR=%I\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;
}
struct ospf_neighbor *
find_neigh_noifa(struct proto_ospf *po, u32 rid)
{
struct ospf_neighbor *n;
struct ospf_iface *ifa;
WALK_LIST (ifa, po->iface_list)
if((n=find_neigh(ifa, rid))!=NULL)
return n;
return NULL;
}
struct ospf_area *
ospf_find_area(struct proto_ospf *po, u32 aid)
{
struct ospf_area *oa;
WALK_LIST(NODE oa,po->area_list)
if(((struct ospf_area *)oa)->areaid==aid) return oa;
return NULL;
}
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