diff options
Diffstat (limited to 'proto/ospf/neighbor.c')
| -rw-r--r-- | proto/ospf/neighbor.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/proto/ospf/neighbor.c b/proto/ospf/neighbor.c new file mode 100644 index 0000000..e4277f7 --- /dev/null +++ b/proto/ospf/neighbor.c @@ -0,0 +1,344 @@ +/* + * 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; +} + |