commit f623ab9875cad2d129f708e95021d3a252930000 Author: Ondrej Zajicek Date: Tue Jun 11 12:12:11 2013 +0200 Implements OSPF stub router option (RFC 3137). Also fixes OSPFv3 routing table calculcation w.r.t. errata 2078 to RFC 5340. diff --git a/doc/bird.sgml b/doc/bird.sgml index 18f3601..0681bd5 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -1904,6 +1904,7 @@ on nonbroadcast networks. protocol ospf <name> { rfc1583compat <switch>; + stub router <switch>; tick <num>; ecmp <switch> [limit <num>]; area <id> { @@ -1983,6 +1984,15 @@ protocol ospf <name> { url="ftp://ftp.rfc-editor.org/in-notes/rfc1583.txt">. Default value is no. + stub router switch + This option configures the router to be a stub router, i.e., + a router that participates in the OSPF topology but does not + allow transit traffic. In OSPFv2, this is implemented by + advertising maximum metric for outgoing links, as suggested + by RFC 3137. + In OSPFv3, the stub router behavior is announced by clearing + the R-bit in the router LSA. Default value is no. + tick num The routing table calculation and clean-up of areas' databases is not performed when a single link state diff --git a/proto/ospf/config.Y b/proto/ospf/config.Y index 2cc0b96..ba050d8 100644 --- a/proto/ospf/config.Y +++ b/proto/ospf/config.Y @@ -158,6 +158,7 @@ ospf_proto: ospf_proto_item: proto_item | RFC1583COMPAT bool { OSPF_CFG->rfc1583 = $2; } + | STUB ROUTER bool { OSPF_CFG->stub_router = $3; } | ECMP bool { OSPF_CFG->ecmp = $2 ? DEFAULT_ECMP_LIMIT : 0; } | ECMP bool LIMIT expr { OSPF_CFG->ecmp = $2 ? $4 : 0; if ($4 < 0) cf_error("ECMP limit cannot be negative"); } | TICK expr { OSPF_CFG->tick = $2; if($2<=0) cf_error("Tick must be greater than zero"); } diff --git a/proto/ospf/ospf.c b/proto/ospf/ospf.c index a3b6b2e..2fa8720 100644 --- a/proto/ospf/ospf.c +++ b/proto/ospf/ospf.c @@ -167,7 +167,7 @@ ospf_area_add(struct proto_ospf *po, struct ospf_area_config *ac, int reconf) #ifdef OSPFv2 oa->options = ac->type; #else /* OSPFv3 */ - oa->options = OPT_R | ac->type | OPT_V6; + oa->options = ac->type | OPT_V6 | (po->stub_router ? 0 : OPT_R); #endif /* @@ -234,6 +234,7 @@ ospf_start(struct proto *p) po->router_id = proto_get_router_id(p->cf); po->last_vlink_id = 0x80000000; po->rfc1583 = c->rfc1583; + po->stub_router = c->stub_router; po->ebit = 0; po->ecmp = c->ecmp; po->tick = c->tick; @@ -690,7 +691,7 @@ ospf_area_reconfigure(struct ospf_area *oa, struct ospf_area_config *nac) #ifdef OSPFv2 oa->options = nac->type; #else /* OSPFv3 */ - oa->options = OPT_R | nac->type | OPT_V6; + oa->options = nac->type | OPT_V6 | (oa->po->stub_router ? 0 : OPT_R); #endif if (oa_is_nssa(oa) && (oa->po->areano > 1)) oa->po->ebit = 1; @@ -738,6 +739,7 @@ ospf_reconfigure(struct proto *p, struct proto_config *c) if (old->abr != new->abr) return 0; + po->stub_router = new->stub_router; po->ecmp = new->ecmp; po->tick = new->tick; po->disp_timer->recurrent = po->tick; @@ -831,6 +833,7 @@ ospf_sh(struct proto *p) cli_msg(-1014, "%s:", p->name); cli_msg(-1014, "RFC1583 compatibility: %s", (po->rfc1583 ? "enable" : "disabled")); + cli_msg(-1014, "Stub router: %s", (po->stub_router ? "Yes" : "No")); cli_msg(-1014, "RT scheduler tick: %d", po->tick); cli_msg(-1014, "Number of areas: %u", po->areano); cli_msg(-1014, "Number of LSAs in DB:\t%u", po->gr->hash_entries); diff --git a/proto/ospf/ospf.h b/proto/ospf/ospf.h index d924e65..7608225 100644 --- a/proto/ospf/ospf.h +++ b/proto/ospf/ospf.h @@ -83,6 +83,7 @@ struct ospf_config struct proto_config c; unsigned tick; byte rfc1583; + byte stub_router; byte abr; int ecmp; list area_list; /* list of struct ospf_area_config */ @@ -771,6 +772,7 @@ struct proto_ospf int areano; /* Number of area I belong to */ struct fib rtf; /* Routing table */ byte rfc1583; /* RFC1583 compatibility */ + byte stub_router; /* Do not forward transit traffic */ byte ebit; /* Did I originate any ext lsa? */ byte ecmp; /* Maximal number of nexthops in ECMP route, or 0 */ struct ospf_area *backbone; /* If exists */ diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c index 4b8de4b..f509b89 100644 --- a/proto/ospf/rt.c +++ b/proto/ospf/rt.c @@ -501,6 +501,10 @@ ospf_rt_spfa(struct ospf_area *oa) #ifdef OSPFv2 ospf_rt_spfa_rtlinks(oa, act, act); #else /* OSPFv3 */ + /* Errata 2078 to RFC 5340 4.8.1 - skip links from non-routing nodes */ + if ((act != oa->rt) && !(rt->options & OPT_R)) + break; + for (tmp = ospf_hash_find_rt_first(po->gr, act->domain, act->lsa.rt); tmp; tmp = ospf_hash_find_rt_next(tmp)) ospf_rt_spfa_rtlinks(oa, act, tmp); @@ -1839,7 +1843,7 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par, if (en->lsa.type == LSA_T_RT) { struct ospf_lsa_rt *rt = en->lsa_body; - if (!(rt->options & OPT_V6) || !(rt->options & OPT_R)) + if (!(rt->options & OPT_V6)) return; } #endif diff --git a/proto/ospf/topology.c b/proto/ospf/topology.c index 5f4d1d5..5d93c0e 100644 --- a/proto/ospf/topology.c +++ b/proto/ospf/topology.c @@ -233,6 +233,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 *length) WALK_LIST(ifa, po->iface_list) { int net_lsa = 0; + u32 link_cost = po->stub_router ? 0xffff : ifa->cost; if ((ifa->type == OSPF_IT_VLINK) && (ifa->voa == oa) && (!EMPTY_LIST(ifa->neigh_list))) @@ -268,8 +269,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 *length) * this address as a next-hop. */ ln->data = ipa_to_u32(ifa->addr->ip); - - ln->metric = ifa->cost; + ln->metric = link_cost; ln->padding = 0; i++; } @@ -283,7 +283,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 *length) ln->type = LSART_NET; ln->id = ipa_to_u32(ifa->drip); ln->data = ipa_to_u32(ifa->addr->ip); - ln->metric = ifa->cost; + ln->metric = link_cost; ln->padding = 0; i++; net_lsa = 1; @@ -298,7 +298,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 *length) ln->type = LSART_VLNK; ln->id = neigh->rid; ln->data = ipa_to_u32(ifa->addr->ip); - ln->metric = ifa->cost; + ln->metric = link_cost; ln->padding = 0; i++; }