/* * BIRD -- OSPF * * (c) 2000 Ondrej Filip <feela@network.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #include "ospf.h" void init_infib(struct fib_node *fn) { struct infib *f=(struct infib *)fn; f->metric=LSINFINITY; f->oldmetric=LSINFINITY; f->en=NULL; f->olden=NULL; } void init_efib(struct fib_node *fn) { struct extfib *f=(struct extfib *)fn; f->metric=LSINFINITY; f->metric2=LSINFINITY; f->nh=ipa_from_u32(0); f->nhi=NULL; f->oldmetric=LSINFINITY; f->oldmetric2=LSINFINITY; f->oldnh=ipa_from_u32(0); } /** * ospf_rt_spfa - calculate internal routes * @oa: OSPF area * * Calculation of internal paths in area is described in 16.1 of RFC 2328. * It's based on Dijkstra shortest path tree algorithmus. * RFC recommends to add ASBR routers into routing table. I don't do this * and latter parts of routing table calculation looks directly into LSA * Database. This function is invoked from area_disp(). */ void ospf_rt_spfa(struct ospf_area *oa) { struct top_hash_entry *en; u32 i,*rts; struct ospf_lsa_rt *rt; struct ospf_lsa_rt_link *rtl,*rr; struct fib *in=&oa->infib; struct infib *nf; struct fib_iterator fit; int age=0,flush=0; struct proto *p=&oa->po->proto; struct proto_ospf *po=oa->po; ip_addr ip; struct ospf_lsa_net *ln; OSPF_TRACE(D_EVENTS, "Starting routing table calculation for area %I", oa->areaid); if(oa->rt==NULL) return; FIB_WALK(in,nftmp) { nf=(struct infib *)nftmp; nf->metric=LSINFINITY; nf->en=NULL; } FIB_WALK_END; init_list(&oa->cand); /* Empty list of candidates */ oa->trcap=0; DBG("LSA db prepared, adding me into candidate list.\n"); oa->rt->dist=0; oa->rt->color=CANDIDATE; add_head(&oa->cand, &oa->rt->cn); DBG("RT LSA: rt: %I, id: %I, type: %u\n",oa->rt->lsa.rt, oa->rt->lsa.id,oa->rt->lsa.type); while(!EMPTY_LIST(oa->cand)) { struct top_hash_entry *act,*tmp; node *n; u16 met; n=HEAD(oa->cand); act=SKIP_BACK(struct top_hash_entry, cn, n); rem_node(n); DBG("Working on LSA: rt: %I, id: %I, type: %u\n",act->lsa.rt, act->lsa.id,act->lsa.type); act->color=INSPF; switch(act->lsa.type) { case LSA_T_RT: rt=(struct ospf_lsa_rt *)act->lsa_body; if(rt->veb.bit.v) oa->trcap=1; rr=(struct ospf_lsa_rt_link *)(rt+1); DBG(" Number of links: %u\n",rt->links); for(i=0;i<rt->links;i++) { tmp=NULL; rtl=(rr+i); DBG(" Working on link: %I (type: %u) ",rtl->id,rtl->type); switch(rtl->type) { case LSART_STUB: /* This violates rfc2328! but I hope it's also correct. */ DBG("\n"); ip=ipa_from_u32(rtl->id); nf=fib_get(in,&ip, ipa_mklen(ipa_from_u32(rtl->data))); if(nf->metric>(met=act->dist+rtl->metric)) { DBG(" Adding stub route....\n"); if(oa->rt==act) break; if(act->nhi==NULL) break; nf->metric=met; nf->en=act; DBG(" Adding stub route: %I\n",ip); DBG(" Next hop=%I\n",nf->en->nh); } else DBG(" NOT adding stub route: %I\n",ip); break; case LSART_VLNK: DBG("Ignoring\n"); continue; break; case LSART_NET: tmp=ospf_hash_find(oa->gr,rtl->id,rtl->id,LSA_T_NET); if(tmp==NULL) DBG("Not found!\n"); else DBG("Found. :-)\n"); break; case LSART_PTP: tmp=ospf_hash_find(oa->gr,rtl->id,rtl->id,LSA_T_RT); DBG("PTP found.\n"); break; default: log("Unknown link type in router lsa."); break; } if(tmp) DBG("Going to add cand, Mydist: %u, Req: %u\n", tmp->dist, act->dist+rtl->metric); add_cand(&oa->cand,tmp,act,act->dist+rtl->metric,oa); } break; case LSA_T_NET: ln=act->lsa_body; ip=ipa_and(ipa_from_u32(act->lsa.id),ln->netmask); nf=fib_get(in,&ip, ipa_mklen(ln->netmask)); if(nf->metric>act->dist) { nf->metric=act->dist; nf->en=act; DBG(" Adding into routing table\n"); } rts=(u32 *)(ln+1); for(i=0;i<(act->lsa.length-sizeof(struct ospf_lsa_header)- sizeof(struct ospf_lsa_net))/sizeof(u32);i++) { DBG(" Working on router %I ", *(rts+i)); tmp=ospf_hash_find(oa->gr, *(rts+i), *(rts+i), LSA_T_RT); if(tmp!=NULL) DBG("Found :-)\n"); else DBG("Not found!\n"); add_cand(&oa->cand,tmp,act,act->dist,oa); } break; } } /* Now sync our fib with nest's */ DBG("Now syncing my rt table with nest's\n"); FIB_ITERATE_INIT(&fit,in); again: FIB_ITERATE_START(in,&fit,nftmp) { nf=(struct infib *)nftmp; if(nf->metric==LSINFINITY) { net *ne; struct top_hash_entry *en=nf->en; ln=en->lsa_body; ne=net_get(p->table, nf->fn.prefix, nf->fn.pxlen); if((en!=NULL)&&(en->nhi!=NULL)) DBG("Deleting rt entry %I\n (P: %x, GW: %I, Iface: %s)\n", nf->fn.prefix, en, en->nh,en->nhi->name); rte_update(p->table, ne, p, NULL); /* Now delete my fib */ FIB_ITERATE_PUT(&fit, nftmp); fib_delete(in, nftmp); goto again; } else { /* Update routing table */ if(nf->en->nhi==NULL) { struct top_hash_entry *en=nf->en; struct ospf_neighbor *neigh; neighbor *nn; if((neigh=find_neigh_noifa(po,en->lsa.rt))==NULL) { goto skip; } nn=neigh_find(p,&neigh->ip,0); DBG(" Next hop calculated: %I\n", nn->addr); en->nh=nn->addr; en->nhi=nn->iface; } if((nf->en!=nf->olden)||(nf->metric!=nf->oldmetric)) { net *ne; rta a0; rte *e; struct top_hash_entry *en=nf->en; ln=en->lsa_body; bzero(&a0, sizeof(a0)); a0.proto=p; a0.source=RTS_OSPF; a0.scope=SCOPE_UNIVERSE; a0.cast=RTC_UNICAST; if(ipa_to_u32(en->nh)==0) a0.dest=RTD_DEVICE; else a0.dest=RTD_ROUTER; a0.flags=0; a0.aflags=0; a0.iface=en->nhi; a0.gw=en->nh; ne=net_get(p->table, nf->fn.prefix, nf->fn.pxlen); e=rte_get_temp(&a0); e->u.ospf.metric1=nf->metric; e->u.ospf.metric2=LSINFINITY; e->u.ospf.tag=0; e->pflags = 0; e->net=ne; e->pref = p->preference; DBG("Modifying rt entry %I\n (GW: %I, Iface: %s)\n", nf->fn.prefix,en->nh,en->nhi->name); rte_update(p->table, ne, p, e); nf->olden=nf->en; nf->oldmetric=nf->metric; } } } skip: FIB_ITERATE_END(nftmp); ospf_ext_spfa(po); } /** * ospf_ext_spfa - calculate external paths * @po: protocol * * After routing table for any area is calculated, calculation of external * path is invoked. This process is described in 16.6 of RFC 2328. * Inter- and Intra-area paths are always prefered over externals. */ void ospf_ext_spfa(struct proto_ospf *po) /* FIXME looking into inter-area */ { struct top_hash_entry *en,*etmp,*absr; struct fib *ef=&po->efib; struct extfib *nf; struct infib *inf; struct fib_iterator fit; struct ospf_area *oa=NULL,*atmp,*absroa; struct proto *p=&po->proto; struct ospf_lsa_ext *le; struct ospf_lsa_ext_tos *lt; struct ospf_lsa_rt *rt; int mlen; ip_addr ip,nnh; struct iface *nnhi=NULL; u16 met,met2; u32 tag; neighbor *nn; OSPF_TRACE(D_EVENTS,"Starting routing table calculation for ext routes"); FIB_WALK(ef,nftmp) { nf=(struct extfib *)nftmp; nf->metric=LSINFINITY; nf->metric2=LSINFINITY; } FIB_WALK_END; WALK_LIST(oa,po->area_list) { if(!oa->stub) break; } if(oa==NULL) return; WALK_SLIST(en,oa->lsal) { if(en->lsa.type!=LSA_T_EXT) continue; if(en->lsa.age==LSA_MAXAGE) continue; if(en->lsa.rt==p->cf->global->router_id) continue; le=en->lsa_body; lt=(struct ospf_lsa_ext_tos *)(le+1); DBG("%s: Working on LSA. ID: %I, RT: %I, Type: %u, Mask %I\n", p->name,en->lsa.id,en->lsa.rt,en->lsa.type,le->netmask); if(lt->metric==LSINFINITY) continue; ip=ipa_and(ipa_from_u32(en->lsa.id),le->netmask); mlen=ipa_mklen(le->netmask); if((mlen<0)||(mlen>32)) { log("%s: Invalid mask in LSA. ID: %I, RT: %I, Type: %u, Mask %I", p->name,en->lsa.id,en->lsa.rt,en->lsa.type,le->netmask); continue; } nf=NULL; WALK_LIST(atmp,po->area_list) { if((nf=fib_find(&atmp->infib,&ip, mlen))!=NULL) break; } if(nf!=NULL) continue; /* Some intra area path exists */ absr=NULL; absroa=NULL; nnhi=NULL; nnh=IPA_NONE; met=0;met2=0;tag=0; WALK_LIST(atmp,po->area_list) /* * Find shortest path * to advertising router */ { if((etmp=ospf_hash_find(atmp->gr,en->lsa.rt,en->lsa.rt,LSA_T_RT))!=NULL) { if((absr==NULL) || (absr->dist>etmp->dist) || ((etmp->dist==absr->dist) && (absroa->areaid<atmp->areaid))) { absr=etmp; absroa=atmp; break; } } } if((absr==NULL)||(absr->dist==LSINFINITY)|| (((struct ospf_lsa_rt *)(absr->lsa_body))->veb.bit.e==0)) { DBG("ASBR is null or its dist=INF\n"); continue; } if(ipa_compare(lt->fwaddr,ipa_from_u32(0))==0) { if(lt->etos>0) /* FW address == 0 */ { met=absr->dist; met2=lt->metric; } else { met=absr->dist+lt->metric; met2=LSINFINITY; } tag=lt->tag; } else /* FW address !=0 */ { inf=NULL; WALK_LIST(atmp,po->area_list) { if((inf=fib_route(&atmp->infib,lt->fwaddr,32))!=NULL) { break; } } if(inf==NULL) { DBG("Cannot find network route (GW=%I)\n",lt->fwaddr); continue; } if(lt->etos>0) { met=inf->metric; met2=lt->metric; } else { met=inf->metric+lt->metric; met2=LSINFINITY; } tag=lt->tag; if((nn=neigh_find(p,<->fwaddr,0))!=NULL) { nnh=lt->fwaddr; nnhi=nn->iface; } else { nnh=inf->en->nh; nnhi=inf->en->nhi; } } nf=fib_get(ef,&ip, mlen); if((nf->metric==LSINFINITY) || /* nf is new */ ((met<nf->metric)&&(nf->metric2==met2)) || /* both E1 or E2 * with same metric */ ((met2<nf->metric2)&&(nf->metric2!=LSINFINITY)) || /* E2 smaller and * 1st is not E1 */ ((nf->metric2!=LSINFINITY)&&(met2==LSINFINITY))) /* 2nd is E1 and * 1st is E2 */ { if(nf->metric!=LSINFINITY) OSPF_TRACE(D_EVENTS, "Rewritting %I/%d met=%d, met2=%d, nmet=%d, nmet2=%d", ip, mlen, nf->metric, nf->metric2, met, met2); nf->metric=met; nf->metric2=met2; nf->tag=tag; if(nnhi!=NULL) { nf->nh=nnh; nf->nhi=nnhi; } else { if(ipa_compare(absr->nh,ipa_from_u32(0))==0) { struct ospf_neighbor *neigh; if((neigh=find_neigh_noifa(po,absr->lsa.rt))==NULL) { DBG("Cannot find neighbor\n"); continue; } nn=neigh_find(p,&neigh->ip,0); DBG(" Next hop calculated: %I\n", nn->addr); nf->nh=nn->addr; nf->nhi=nn->iface; } else { nf->nh=absr->nh; nf->nhi=absr->nhi; } } } } DBG("Now syncing my rt table with nest's\n"); FIB_ITERATE_INIT(&fit,ef); noch: FIB_ITERATE_START(ef,&fit,nftmp) { nf=(struct extfib *)nftmp; if(nf->metric==LSINFINITY) { net *ne; ne=net_get(p->table, nf->fn.prefix, nf->fn.pxlen); DBG("Deleting rt entry %I\n (IP: %I, GW: %I)\n", nf->fn.prefix,ip,nf->nh); rte_update(p->table, ne, p, NULL); /* Now delete my fib */ FIB_ITERATE_PUT(&fit, nftmp); fib_delete(ef, nftmp); goto noch; } else if((nf->metric!=nf->oldmetric)||(nf->metric2!=nf->oldmetric2)|| (!ipa_equal(nf->nh,nf->oldnh))||(nf->tag!=nf->oldtag)) { net *ne; rta a0; rte *e; bzero(&a0, sizeof(a0)); a0.proto=p; a0.source=RTS_OSPF_EXT; a0.scope=SCOPE_UNIVERSE; a0.cast=RTC_UNICAST; a0.dest=RTD_ROUTER; a0.flags=0; a0.aflags=0; a0.iface=nf->nhi; a0.gw=nf->nh; ne=net_get(p->table, nf->fn.prefix, nf->fn.pxlen); e=rte_get_temp(&a0); e->u.ospf.metric1=nf->metric; e->u.ospf.metric2=nf->metric2; e->u.ospf.tag=nf->tag; e->pflags = 0; e->net=ne; e->pref = p->preference; DBG("Modifying rt entry %I\n (IP: %I, GW: %I)\n", nf->fn.prefix,ip,nf->nh); rte_update(p->table, ne, p, e); nf->oldmetric=nf->metric; nf->oldmetric2=nf->metric2; nf->oldnh=nf->nh; nf->oldtag=nf->tag; } } let: FIB_ITERATE_END(nftmp); } /* Add LSA into list of candidates in Dijkstra alogithm */ void add_cand(list *l, struct top_hash_entry *en, struct top_hash_entry *par, u16 dist, struct ospf_area *oa) { node *prev,*n; int flag=0,added=0; struct top_hash_entry *act; struct proto *p=&oa->po->proto; if(en==NULL) return; if(en->lsa.age==LSA_MAXAGE) return; /* FIXME Does it have link back? Test it! */ if(en->color==INSPF) return; if(dist>=en->dist) return; /* * FIXME The line above is not a bug, but we don't support * multiple next hops. I'll start as soon as nest will */ DBG(" Adding candidate: rt: %I, id: %I, type: %u\n",en->lsa.rt,en->lsa.id,en->lsa.type); en->nhi=NULL; calc_next_hop(en, par, oa); if(en->color==CANDIDATE) /* We found a shorter path */ { rem_node(&en->cn); } en->dist=dist; en->color=CANDIDATE; prev=NULL; if(EMPTY_LIST(*l)) { add_head(l,&en->cn); } else { WALK_LIST(n,*l) { act=SKIP_BACK(struct top_hash_entry, cn, n); if((act->dist>dist)|| ((act->dist==dist)&&(act->lsa.type==LSA_T_NET))) { if(prev==NULL) add_head(l,&en->cn); else insert_node(&en->cn,prev); added=1; break; } prev=n; } if(!added) { add_tail(l,&en->cn); } } /* FIXME Some VLINK stuff should be here */ } void calc_next_hop(struct top_hash_entry *en, struct top_hash_entry *par, struct ospf_area *oa) { struct ospf_neighbor *neigh; struct proto *p=&oa->po->proto; struct proto_ospf *po=oa->po; struct ospf_iface *ifa; u32 myrid=p->cf->global->router_id; DBG(" Next hop called.\n"); if(ipa_to_u32(par->nh)==0) { neighbor *nn; DBG(" Next hop calculating for id: %I rt: %I type: %u\n", en->lsa.id,en->lsa.rt,en->lsa.type); /* xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx */ if(par==oa->rt) { if(en->lsa.type==LSA_T_NET) { if(en->lsa.rt==myrid) { WALK_LIST(ifa,po->iface_list) if(ipa_compare(ifa->iface->addr->ip,ipa_from_u32(en->lsa.id))==0) { en->nhi=ifa->iface; return; } bug("I didn't find interface for my self originated LSA!\n"); } else { ip_addr ip=ipa_from_u32(en->lsa.id); nn=neigh_find(p,&ip,0); if(nn) en->nhi=nn->iface; return; } } else { if((neigh=find_neigh_noifa(po,en->lsa.rt))==NULL) return; en->nhi=neigh->ifa->iface; return; } } if(par->lsa.type==LSA_T_NET) { if(en->lsa.type==LSA_T_NET) bug("Parent for net is net?"); if((en->nhi=par->nhi)==NULL) bug("Did not find next hop interface for INSPF lsa!"); return; } else /* Parent is some RT neighbor */ { /* FIXME: I should probably hold ospf_iface in top_hash_entry */ neigh=NULL; WALK_LIST(ifa,po->iface_list) { if(ifa->iface==par->nhi) { if((neigh=find_neigh(ifa,par->lsa.rt))==NULL) return; break; } } if(neigh==NULL) bug("I cannot find my neighbor."); nn=neigh_find(p,&neigh->ip,0); if(nn) { en->nhi=nn->iface; en->nh=neigh->ip; } return; } } en->nh=par->nh; en->nhi=par->nhi; DBG(" Next hop calculated: %I.\n", en->nh); }