summaryrefslogtreecommitdiffstats
path: root/proto/ospf/neighbor.c
diff options
context:
space:
mode:
Diffstat (limited to 'proto/ospf/neighbor.c')
-rw-r--r--proto/ospf/neighbor.c344
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;
+}
+