iof-bird-daemon / proto / ospf / rt.c @ 62e64905
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/*
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* BIRD -- OSPF
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*
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* (c) 2000--2004 Ondrej Filip <feela@network.cz>
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* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
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* (c) 2009--2014 CZ.NIC z.s.p.o.
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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|
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#include "ospf.h" |
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|
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static void add_cand(list * l, struct top_hash_entry *en, |
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struct top_hash_entry *par, u32 dist,
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struct ospf_area *oa, int i); |
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static void rt_sync(struct ospf_proto *p); |
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static inline void reset_ri(ort *ort) |
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{
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bzero(&ort->n, sizeof(orta));
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} |
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static inline int |
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nh_is_vlink(struct nexthop *nhs)
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{
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return !nhs->iface;
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} |
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|
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static inline int |
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unresolved_vlink(ort *ort) |
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{
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return ort->n.nhs && nh_is_vlink(ort->n.nhs);
|
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} |
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|
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static inline struct nexthop * |
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new_nexthop(struct ospf_proto *p, ip_addr gw, struct iface *iface, byte weight) |
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{
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struct nexthop *nh = lp_allocz(p->nhpool, sizeof(struct nexthop)); |
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nh->gw = gw; |
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nh->iface = iface; |
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nh->weight = weight; |
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return nh;
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} |
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|
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/* Returns true if there are device nexthops in n */
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static inline int |
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has_device_nexthops(const struct nexthop *n) |
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{
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for (; n; n = n->next)
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if (ipa_zero(n->gw))
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return 1; |
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|
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return 0; |
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} |
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|
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/* Replace device nexthops with nexthops to gw */
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static struct nexthop * |
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fix_device_nexthops(struct ospf_proto *p, const struct nexthop *n, ip_addr gw) |
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{
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struct nexthop *root1 = NULL; |
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struct nexthop *root2 = NULL; |
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struct nexthop **nn1 = &root1;
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struct nexthop **nn2 = &root2;
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if (!p->ecmp)
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return new_nexthop(p, gw, n->iface, n->weight);
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|
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/* This is a bit tricky. We cannot just copy the list and update n->gw,
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because the list should stay sorted, so we create two lists, one with new
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gateways and one with old ones, and then merge them. */
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for (; n; n = n->next)
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{
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struct nexthop *nn = new_nexthop(p, ipa_zero(n->gw) ? gw : n->gw, n->iface, n->weight);
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if (ipa_zero(n->gw))
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{
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*nn1 = nn; |
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nn1 = &(nn->next); |
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} |
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else
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{
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*nn2 = nn; |
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nn2 = &(nn->next); |
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} |
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} |
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return nexthop_merge(root1, root2, 1, 1, p->ecmp, p->nhpool); |
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} |
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|
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/* Whether the ASBR or the forward address destination is preferred
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in AS external route selection according to 16.4.1. */
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static inline int |
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epath_preferred(const orta *ep)
|
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{
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return (ep->type == RTS_OSPF) && (ep->oa->areaid != 0); |
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} |
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|
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/* Whether the ext route has ASBR/next_hop marked as preferred. */
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static inline int |
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orta_pref(const orta *nf)
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{
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return !!(nf->options & ORTA_PREF);
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} |
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|
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/* Classify orta entries according to RFC 3101 2.5 (6e) priorities:
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Type-7 LSA with P-bit, Type-5 LSA, Type-7 LSA without P-bit */
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static int |
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orta_prio(const orta *nf)
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{
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/* RFC 3103 2.5 (6e) priorities */
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u32 opts = nf->options & (ORTA_NSSA | ORTA_PROP); |
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/* A Type-7 LSA with the P-bit set */
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if (opts == (ORTA_NSSA | ORTA_PROP))
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return 2; |
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/* A Type-5 LSA */
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if (opts == 0) |
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return 1; |
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return 0; |
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} |
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|
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/* Whether the route is better according to RFC 3101 2.5 (6e):
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Prioritize Type-7 LSA with P-bit, then Type-5 LSA, then higher router ID */
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static int |
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orta_prefer_lsa(const orta *new, const orta *old) |
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{
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int pn = orta_prio(new);
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int po = orta_prio(old);
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return (pn > po) || ((pn == po) && (new->en->lsa.rt > old->en->lsa.rt));
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} |
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|
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/*
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* Compare an existing routing table entry with a new one. Applicable for
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* intra-area routes, inter-area routes and router entries. Returns integer
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* <, = or > than 0 if the new orta is less, equal or more preferred than
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* the old orta.
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*/
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static int |
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orta_compare(const struct ospf_proto *p, const orta *new, const orta *old) |
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{
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int r;
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if (old->type == RTS_DUMMY)
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return 1; |
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|
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/* Prefer intra-area to inter-area to externals */
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r = ((int) old->type) - ((int) new->type); |
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if (r) return r; |
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|
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/* Prefer lowest type 1 metric */
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r = ((int) old->metric1) - ((int) new->metric1); |
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if (r) return r; |
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|
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/* Rest is BIRD-specific */
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|
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/* Area-wide routes should not mix next-hops from different areas.
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This generally should not happen unless there is some misconfiguration. */
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if (new->oa->areaid != old->oa->areaid)
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return (new->oa->areaid > old->oa->areaid) ? 1 : -1; |
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|
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/* Prefer routes for configured stubnets (!nhs) to regular routes to dummy
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vlink nexthops. We intentionally return -1 if both are stubnets or vlinks. */
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if (!old->nhs)
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return -1; |
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if (!new->nhs)
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return 1; |
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if (nh_is_vlink(new->nhs))
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return -1; |
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if (nh_is_vlink(old->nhs))
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return 1; |
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|
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if (p->ecmp)
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return 0; |
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|
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/* Prefer routes with higher Router ID, just to be more deterministic */
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if (new->rid > old->rid)
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return 1; |
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return -1; |
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} |
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|
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/*
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* Compare ASBR routing table entry with a new one, used for precompute ASBRs
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* for AS external route selection (RFC 2328 16.4 (3)), Returns integer < or >
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* than 0 if the new ASBR is less or more preferred than the old ASBR.
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*/
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static int |
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orta_compare_asbr(const struct ospf_proto *p, const orta *new, const orta *old) |
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{
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int r;
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if (old->type == RTS_DUMMY)
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return 1; |
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if (!p->rfc1583)
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{
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r = epath_preferred(new) - epath_preferred(old); |
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if (r) return r; |
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} |
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r = ((int) old->metric1) - ((int) new->metric1); |
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if (r) return r; |
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/* Larger area ID is preferred */
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if (new->oa->areaid > old->oa->areaid)
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return 1; |
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/* There is just one ASBR of that RID per area, so tie is not possible */
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return -1; |
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} |
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|
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/*
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* Compare a routing table entry with a new one, for AS external routes
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* (RFC 2328 16.4) and NSSA routes (RFC 3103 2.5), Returns integer <, = or >
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* than 0 if the new orta is less, equal or more preferred than the old orta.
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*/
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static int |
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orta_compare_ext(const struct ospf_proto *p, const orta *new, const orta *old) |
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{
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int r;
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|
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if (old->type == RTS_DUMMY)
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return 1; |
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|
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/* 16.4 (6a) - prefer routes with lower type */
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r = ((int) old->type) - ((int) new->type); |
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if (r) return r; |
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|
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/* 16.4 (6b) - prefer routes with lower type 2 metric */
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if (new->type == RTS_OSPF_EXT2)
|
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{
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r = ((int) old->metric2) - ((int) new->metric2); |
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if (r) return r; |
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} |
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|
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/* 16.4 (6c) - if not RFC1583, prefer routes with preferred ASBR/next_hop */
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if (!p->rfc1583)
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{
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r = orta_pref(new) - orta_pref(old); |
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if (r) return r; |
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} |
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|
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/* 16.4 (6d) - prefer routes with lower type 1 metric */
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r = ((int) old->metric1) - ((int) new->metric1); |
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if (r) return r; |
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|
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if (p->ecmp && p->merge_external)
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return 0; |
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|
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/*
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* RFC 3101 2.5 (6e) - prioritize Type-7 LSA with P-bit, then Type-5 LSA, then
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* LSA with higher router ID. Although this should apply just to functionally
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* equivalent LSAs (i.e. ones with the same non-zero forwarding address), we
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* use it also to disambiguate otherwise equally preferred nexthops.
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*/
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if (orta_prefer_lsa(new, old))
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return 1; |
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return -1; |
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} |
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|
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|
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static inline void |
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ort_replace(ort *o, const orta *new)
|
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{
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memcpy(&o->n, new, sizeof(orta));
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} |
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|
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static void |
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ort_merge(struct ospf_proto *p, ort *o, const orta *new) |
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{
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orta *old = &o->n; |
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|
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if (old->nhs != new->nhs)
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{
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old->nhs = nexthop_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse, |
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p->ecmp, p->nhpool); |
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old->nhs_reuse = 1;
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} |
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|
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if (old->rid < new->rid)
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old->rid = new->rid; |
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} |
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|
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static void |
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ort_merge_ext(struct ospf_proto *p, ort *o, const orta *new) |
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{
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orta *old = &o->n; |
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if (old->nhs != new->nhs)
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{
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old->nhs = nexthop_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse, |
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p->ecmp, p->nhpool); |
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old->nhs_reuse = 1;
|
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} |
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|
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if (old->tag != new->tag)
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old->tag = 0;
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|
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/*
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* Even with multipath, we store only one LSA in orta.en for the purpose of
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* NSSA/ext translation. Therefore, we apply procedures from RFC 3101 2.5 (6e)
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* to all chosen LSAs for given network, not just to functionally equivalent
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* ones (i.e. ones with the same non-zero forwarding address).
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*/
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if (orta_prefer_lsa(new, old))
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{
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old->options = new->options; |
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old->rid = new->rid; |
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old->oa = new->oa; |
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old->en = new->en; |
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} |
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} |
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|
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|
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|
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static inline void |
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ri_install_net(struct ospf_proto *p, net_addr *net, const orta *new) |
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{
|
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ort *old = fib_get(&p->rtf, net); |
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int cmp = orta_compare(p, new, &old->n);
|
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|
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if (cmp > 0) |
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ort_replace(old, new); |
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else if (cmp == 0) |
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ort_merge(p, old, new); |
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} |
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|
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static inline void |
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ri_install_rt(struct ospf_area *oa, u32 rid, const orta *new) |
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{
|
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net_addr_ip4 nrid = net_from_rid(rid); |
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ort *old = fib_get(&oa->rtr, (net_addr *) &nrid); |
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int cmp = orta_compare(oa->po, new, &old->n);
|
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|
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if (cmp > 0) |
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ort_replace(old, new); |
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else if (cmp == 0) |
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ort_merge(oa->po, old, new); |
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} |
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|
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static inline void |
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ri_install_asbr(struct ospf_proto *p, u32 rid, const orta *new) |
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{
|
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net_addr_ip4 nrid = net_from_rid(rid); |
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ort *old = fib_get(&p->backbone->rtr, (net_addr *) &nrid); |
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|
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if (orta_compare_asbr(p, new, &old->n) > 0) |
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ort_replace(old, new); |
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} |
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|
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static inline void |
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ri_install_ext(struct ospf_proto *p, net_addr *net, const orta *new) |
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{
|
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ort *old = fib_get(&p->rtf, net); |
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int cmp = orta_compare_ext(p, new, &old->n);
|
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|
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if (cmp > 0) |
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ort_replace(old, new); |
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else if (cmp == 0) |
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ort_merge_ext(p, old, new); |
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} |
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|
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static inline struct ospf_iface * |
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rt_pos_to_ifa(struct ospf_area *oa, int pos) |
| 375 |
{
|
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struct ospf_iface *ifa;
|
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|
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WALK_LIST(ifa, oa->po->iface_list) |
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if (ifa->oa == oa && pos >= ifa->rt_pos_beg && pos < ifa->rt_pos_end)
|
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return ifa;
|
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|
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return NULL; |
| 383 |
} |
| 384 |
|
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static inline struct ospf_iface * |
| 386 |
px_pos_to_ifa(struct ospf_area *oa, int pos) |
| 387 |
{
|
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struct ospf_iface *ifa;
|
| 389 |
|
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WALK_LIST(ifa, oa->po->iface_list) |
| 391 |
if (ifa->oa == oa && pos >= ifa->px_pos_beg && pos < ifa->px_pos_end)
|
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return ifa;
|
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|
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return NULL; |
| 395 |
} |
| 396 |
|
| 397 |
|
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static void |
| 399 |
add_network(struct ospf_area *oa, net_addr *net, int metric, struct top_hash_entry *en, int pos) |
| 400 |
{
|
| 401 |
struct ospf_proto *p = oa->po;
|
| 402 |
|
| 403 |
orta nf = {
|
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.type = RTS_OSPF, |
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.options = 0,
|
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.metric1 = metric, |
| 407 |
.metric2 = LSINFINITY, |
| 408 |
.tag = 0,
|
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.rid = en->lsa.rt, |
| 410 |
.oa = oa, |
| 411 |
.nhs = en->nhs |
| 412 |
}; |
| 413 |
|
| 414 |
if (!ospf_valid_prefix(net))
|
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{
|
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log(L_WARN "%s: Invalid prefix in LSA (Type: %04x, Id: %R, Rt: %R)",
|
| 417 |
p->p.name, en->lsa_type, en->lsa.id, en->lsa.rt); |
| 418 |
return;
|
| 419 |
} |
| 420 |
|
| 421 |
if (en == oa->rt)
|
| 422 |
{
|
| 423 |
/*
|
| 424 |
* Local stub networks does not have proper iface in en->nhi
|
| 425 |
* (because they all have common top_hash_entry en).
|
| 426 |
* We have to find iface responsible for that stub network.
|
| 427 |
* Configured stubnets does not have any iface. They will
|
| 428 |
* be removed in rt_sync().
|
| 429 |
*/
|
| 430 |
|
| 431 |
struct ospf_iface *ifa;
|
| 432 |
ifa = ospf_is_v2(p) ? rt_pos_to_ifa(oa, pos) : px_pos_to_ifa(oa, pos); |
| 433 |
nf.nhs = ifa ? new_nexthop(p, IPA_NONE, ifa->iface, ifa->ecmp_weight) : NULL;
|
| 434 |
} |
| 435 |
|
| 436 |
ri_install_net(p, net, &nf); |
| 437 |
} |
| 438 |
|
| 439 |
|
| 440 |
|
| 441 |
static inline void |
| 442 |
spfa_process_rt(struct ospf_proto *p, struct ospf_area *oa, struct top_hash_entry *act) |
| 443 |
{
|
| 444 |
struct ospf_lsa_rt *rt = act->lsa_body;
|
| 445 |
struct ospf_lsa_rt_walk rtl;
|
| 446 |
struct top_hash_entry *tmp;
|
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int i;
|
| 448 |
|
| 449 |
if (rt->options & OPT_RT_V)
|
| 450 |
oa->trcap = 1;
|
| 451 |
|
| 452 |
/*
|
| 453 |
* In OSPFv3, all routers are added to per-area routing
|
| 454 |
* tables. But we use it just for ASBRs and ABRs. For the
|
| 455 |
* purpose of the last step in SPF - prefix-LSA processing in
|
| 456 |
* spfa_process_prefixes(), we use information stored in LSA db.
|
| 457 |
*/
|
| 458 |
if (((rt->options & OPT_RT_E) || (rt->options & OPT_RT_B))
|
| 459 |
&& (act->lsa.rt != p->router_id)) |
| 460 |
{
|
| 461 |
orta nf = {
|
| 462 |
.type = RTS_OSPF, |
| 463 |
.options = rt->options, |
| 464 |
.metric1 = act->dist, |
| 465 |
.metric2 = LSINFINITY, |
| 466 |
.tag = 0,
|
| 467 |
.rid = act->lsa.rt, |
| 468 |
.oa = oa, |
| 469 |
.nhs = act->nhs |
| 470 |
}; |
| 471 |
ri_install_rt(oa, act->lsa.rt, &nf); |
| 472 |
} |
| 473 |
|
| 474 |
/* Errata 2078 to RFC 5340 4.8.1 - skip links from non-routing nodes */
|
| 475 |
if (ospf_is_v3(p) && (act != oa->rt) && !(rt->options & OPT_R))
|
| 476 |
return;
|
| 477 |
|
| 478 |
/* Now process Rt links */
|
| 479 |
for (lsa_walk_rt_init(p, act, &rtl), i = 0; lsa_walk_rt(&rtl); i++) |
| 480 |
{
|
| 481 |
tmp = NULL;
|
| 482 |
|
| 483 |
switch (rtl.type)
|
| 484 |
{
|
| 485 |
case LSART_STUB:
|
| 486 |
|
| 487 |
/* Should not happen, LSART_STUB is not defined in OSPFv3 */
|
| 488 |
if (ospf_is_v3(p))
|
| 489 |
break;
|
| 490 |
|
| 491 |
/*
|
| 492 |
* RFC 2328 in 16.1. (2a) says to handle stub networks in an
|
| 493 |
* second phase after the SPF for an area is calculated. We get
|
| 494 |
* the same result by handing them here because add_network()
|
| 495 |
* will keep the best (not the first) found route.
|
| 496 |
*/
|
| 497 |
net_addr_ip4 net = |
| 498 |
NET_ADDR_IP4(ip4_from_u32(rtl.id & rtl.data), u32_masklen(rtl.data)); |
| 499 |
|
| 500 |
add_network(oa, (net_addr *) &net, act->dist + rtl.metric, act, i); |
| 501 |
break;
|
| 502 |
|
| 503 |
case LSART_NET:
|
| 504 |
tmp = ospf_hash_find_net(p->gr, oa->areaid, rtl.id, rtl.nif); |
| 505 |
break;
|
| 506 |
|
| 507 |
case LSART_VLNK:
|
| 508 |
case LSART_PTP:
|
| 509 |
tmp = ospf_hash_find_rt(p->gr, oa->areaid, rtl.id); |
| 510 |
break;
|
| 511 |
} |
| 512 |
|
| 513 |
add_cand(&oa->cand, tmp, act, act->dist + rtl.metric, oa, i); |
| 514 |
} |
| 515 |
} |
| 516 |
|
| 517 |
static inline void |
| 518 |
spfa_process_net(struct ospf_proto *p, struct ospf_area *oa, struct top_hash_entry *act) |
| 519 |
{
|
| 520 |
struct ospf_lsa_net *ln = act->lsa_body;
|
| 521 |
struct top_hash_entry *tmp;
|
| 522 |
int i, cnt;
|
| 523 |
|
| 524 |
if (ospf_is_v2(p))
|
| 525 |
{
|
| 526 |
net_addr_ip4 net = |
| 527 |
NET_ADDR_IP4(ip4_from_u32(act->lsa.id & ln->optx), u32_masklen(ln->optx)); |
| 528 |
|
| 529 |
add_network(oa, (net_addr *) &net, act->dist, act, -1);
|
| 530 |
} |
| 531 |
|
| 532 |
cnt = lsa_net_count(&act->lsa); |
| 533 |
for (i = 0; i < cnt; i++) |
| 534 |
{
|
| 535 |
tmp = ospf_hash_find_rt(p->gr, oa->areaid, ln->routers[i]); |
| 536 |
add_cand(&oa->cand, tmp, act, act->dist, oa, -1);
|
| 537 |
} |
| 538 |
} |
| 539 |
|
| 540 |
static inline void |
| 541 |
spfa_process_prefixes(struct ospf_proto *p, struct ospf_area *oa) |
| 542 |
{
|
| 543 |
struct top_hash_entry *en, *src;
|
| 544 |
struct ospf_lsa_prefix *px;
|
| 545 |
u32 *buf; |
| 546 |
int i;
|
| 547 |
|
| 548 |
WALK_SLIST(en, p->lsal) |
| 549 |
{
|
| 550 |
if (en->lsa_type != LSA_T_PREFIX)
|
| 551 |
continue;
|
| 552 |
|
| 553 |
if (en->domain != oa->areaid)
|
| 554 |
continue;
|
| 555 |
|
| 556 |
if (en->lsa.age == LSA_MAXAGE)
|
| 557 |
continue;
|
| 558 |
|
| 559 |
px = en->lsa_body; |
| 560 |
|
| 561 |
/* For router prefix-LSA, we would like to find the first router-LSA */
|
| 562 |
if (px->ref_type == LSA_T_RT)
|
| 563 |
src = ospf_hash_find_rt(p->gr, oa->areaid, px->ref_rt); |
| 564 |
else
|
| 565 |
src = ospf_hash_find(p->gr, oa->areaid, px->ref_id, px->ref_rt, px->ref_type); |
| 566 |
|
| 567 |
if (!src)
|
| 568 |
continue;
|
| 569 |
|
| 570 |
/* Reachable in SPF */
|
| 571 |
if (src->color != INSPF)
|
| 572 |
continue;
|
| 573 |
|
| 574 |
if ((src->lsa_type != LSA_T_RT) && (src->lsa_type != LSA_T_NET))
|
| 575 |
continue;
|
| 576 |
|
| 577 |
buf = px->rest; |
| 578 |
for (i = 0; i < px->pxcount; i++) |
| 579 |
{
|
| 580 |
net_addr_ip6 net; |
| 581 |
u8 pxopts; |
| 582 |
u16 metric; |
| 583 |
|
| 584 |
buf = ospf_get_ipv6_prefix(buf, (net_addr *) &net, &pxopts, &metric); |
| 585 |
|
| 586 |
if (pxopts & OPT_PX_NU)
|
| 587 |
continue;
|
| 588 |
|
| 589 |
/* Store the first global address to use it later as a vlink endpoint */
|
| 590 |
if ((pxopts & OPT_PX_LA) && ipa_zero(src->lb))
|
| 591 |
src->lb = ipa_from_ip6(net.prefix); |
| 592 |
|
| 593 |
add_network(oa, (net_addr *) &net, src->dist + metric, src, i); |
| 594 |
} |
| 595 |
} |
| 596 |
} |
| 597 |
|
| 598 |
/* RFC 2328 16.1. calculating shortest paths for an area */
|
| 599 |
static void |
| 600 |
ospf_rt_spfa(struct ospf_area *oa)
|
| 601 |
{
|
| 602 |
struct ospf_proto *p = oa->po;
|
| 603 |
struct top_hash_entry *act;
|
| 604 |
node *n; |
| 605 |
|
| 606 |
if (oa->rt == NULL) |
| 607 |
return;
|
| 608 |
if (oa->rt->lsa.age == LSA_MAXAGE)
|
| 609 |
return;
|
| 610 |
|
| 611 |
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for area %R", oa->areaid);
|
| 612 |
|
| 613 |
/* 16.1. (1) */
|
| 614 |
init_list(&oa->cand); /* Empty list of candidates */
|
| 615 |
oa->trcap = 0;
|
| 616 |
|
| 617 |
DBG("LSA db prepared, adding me into candidate list.\n");
|
| 618 |
|
| 619 |
oa->rt->dist = 0;
|
| 620 |
oa->rt->color = CANDIDATE; |
| 621 |
add_head(&oa->cand, &oa->rt->cn); |
| 622 |
DBG("RT LSA: rt: %R, id: %R, type: %u\n",
|
| 623 |
oa->rt->lsa.rt, oa->rt->lsa.id, oa->rt->lsa_type); |
| 624 |
|
| 625 |
while (!EMPTY_LIST(oa->cand))
|
| 626 |
{
|
| 627 |
n = HEAD(oa->cand); |
| 628 |
act = SKIP_BACK(struct top_hash_entry, cn, n);
|
| 629 |
rem_node(n); |
| 630 |
|
| 631 |
DBG("Working on LSA: rt: %R, id: %R, type: %u\n",
|
| 632 |
act->lsa.rt, act->lsa.id, act->lsa_type); |
| 633 |
|
| 634 |
act->color = INSPF; |
| 635 |
switch (act->lsa_type)
|
| 636 |
{
|
| 637 |
case LSA_T_RT:
|
| 638 |
spfa_process_rt(p, oa, act); |
| 639 |
break;
|
| 640 |
|
| 641 |
case LSA_T_NET:
|
| 642 |
spfa_process_net(p, oa, act); |
| 643 |
break;
|
| 644 |
|
| 645 |
default:
|
| 646 |
log(L_WARN "%s: Unknown LSA type in SPF: %d", p->p.name, act->lsa_type);
|
| 647 |
} |
| 648 |
} |
| 649 |
|
| 650 |
if (ospf_is_v3(p))
|
| 651 |
spfa_process_prefixes(p, oa); |
| 652 |
} |
| 653 |
|
| 654 |
static int |
| 655 |
link_back(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry *par) |
| 656 |
{
|
| 657 |
struct ospf_proto *p = oa->po;
|
| 658 |
struct ospf_lsa_rt_walk rtl;
|
| 659 |
struct top_hash_entry *tmp;
|
| 660 |
struct ospf_lsa_net *ln;
|
| 661 |
u32 i, cnt; |
| 662 |
|
| 663 |
if (!en || !par) return 0; |
| 664 |
|
| 665 |
/* We should check whether there is a link back from en to par,
|
| 666 |
this is used in SPF calc (RFC 2328 16.1. (2b)). According to RFC 2328
|
| 667 |
note 23, we don't have to find the same link that is used for par
|
| 668 |
to en, any link is enough. This we do for ptp links. For net-rt
|
| 669 |
links, we have to find the same link to compute proper lb/lb_id,
|
| 670 |
which may be later used as the next hop. */
|
| 671 |
|
| 672 |
/* In OSPFv2, en->lb is set here. In OSPFv3, en->lb is just cleared here,
|
| 673 |
it is set in process_prefixes() to any global address in the area */
|
| 674 |
|
| 675 |
en->lb = IPA_NONE; |
| 676 |
en->lb_id = 0;
|
| 677 |
|
| 678 |
switch (en->lsa_type)
|
| 679 |
{
|
| 680 |
case LSA_T_RT:
|
| 681 |
lsa_walk_rt_init(p, en, &rtl); |
| 682 |
while (lsa_walk_rt(&rtl))
|
| 683 |
{
|
| 684 |
switch (rtl.type)
|
| 685 |
{
|
| 686 |
case LSART_STUB:
|
| 687 |
break;
|
| 688 |
|
| 689 |
case LSART_NET:
|
| 690 |
tmp = ospf_hash_find_net(p->gr, oa->areaid, rtl.id, rtl.nif); |
| 691 |
if (tmp == par)
|
| 692 |
{
|
| 693 |
if (ospf_is_v2(p))
|
| 694 |
en->lb = ipa_from_u32(rtl.data); |
| 695 |
else
|
| 696 |
en->lb_id = rtl.lif; |
| 697 |
|
| 698 |
return 1; |
| 699 |
} |
| 700 |
break;
|
| 701 |
|
| 702 |
case LSART_VLNK:
|
| 703 |
case LSART_PTP:
|
| 704 |
/* Not necessary the same link, see RFC 2328 [23] */
|
| 705 |
tmp = ospf_hash_find_rt(p->gr, oa->areaid, rtl.id); |
| 706 |
if (tmp == par)
|
| 707 |
return 1; |
| 708 |
break;
|
| 709 |
} |
| 710 |
} |
| 711 |
break;
|
| 712 |
|
| 713 |
case LSA_T_NET:
|
| 714 |
ln = en->lsa_body; |
| 715 |
cnt = lsa_net_count(&en->lsa); |
| 716 |
for (i = 0; i < cnt; i++) |
| 717 |
{
|
| 718 |
tmp = ospf_hash_find_rt(p->gr, oa->areaid, ln->routers[i]); |
| 719 |
if (tmp == par)
|
| 720 |
return 1; |
| 721 |
} |
| 722 |
break;
|
| 723 |
|
| 724 |
default:
|
| 725 |
log(L_WARN "%s: Unknown LSA type in SPF: %d", p->p.name, en->lsa_type);
|
| 726 |
} |
| 727 |
return 0; |
| 728 |
} |
| 729 |
|
| 730 |
|
| 731 |
/* RFC 2328 16.2. calculating inter-area routes */
|
| 732 |
static void |
| 733 |
ospf_rt_sum(struct ospf_area *oa)
|
| 734 |
{
|
| 735 |
struct ospf_proto *p = oa->po;
|
| 736 |
struct top_hash_entry *en;
|
| 737 |
net_addr net; |
| 738 |
u32 dst_rid, metric, options; |
| 739 |
ort *abr; |
| 740 |
int type;
|
| 741 |
u8 pxopts; |
| 742 |
|
| 743 |
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for inter-area (area %R)", oa->areaid);
|
| 744 |
|
| 745 |
WALK_SLIST(en, p->lsal) |
| 746 |
{
|
| 747 |
if ((en->lsa_type != LSA_T_SUM_RT) && (en->lsa_type != LSA_T_SUM_NET))
|
| 748 |
continue;
|
| 749 |
|
| 750 |
if (en->domain != oa->areaid)
|
| 751 |
continue;
|
| 752 |
|
| 753 |
/* 16.2. (1a) */
|
| 754 |
if (en->lsa.age == LSA_MAXAGE)
|
| 755 |
continue;
|
| 756 |
|
| 757 |
/* 16.2. (2) */
|
| 758 |
if (en->lsa.rt == p->router_id)
|
| 759 |
continue;
|
| 760 |
|
| 761 |
/* 16.2. (3) is handled later in ospf_rt_abr() by resetting such rt entry */
|
| 762 |
|
| 763 |
if (en->lsa_type == LSA_T_SUM_NET)
|
| 764 |
{
|
| 765 |
lsa_parse_sum_net(en, ospf_is_v2(p), &net, &pxopts, &metric); |
| 766 |
|
| 767 |
if (!ospf_valid_prefix(&net))
|
| 768 |
{
|
| 769 |
log(L_WARN "%s: Invalid prefix in LSA (Type: %04x, Id: %R, Rt: %R)",
|
| 770 |
p->p.name, en->lsa_type, en->lsa.id, en->lsa.rt); |
| 771 |
continue;
|
| 772 |
} |
| 773 |
|
| 774 |
if (pxopts & OPT_PX_NU)
|
| 775 |
continue;
|
| 776 |
|
| 777 |
options = 0;
|
| 778 |
type = ORT_NET; |
| 779 |
} |
| 780 |
else /* LSA_T_SUM_RT */ |
| 781 |
{
|
| 782 |
lsa_parse_sum_rt(en, ospf_is_v2(p), &dst_rid, &metric, &options); |
| 783 |
|
| 784 |
/* We don't want local router in ASBR routing table */
|
| 785 |
if (dst_rid == p->router_id)
|
| 786 |
continue;
|
| 787 |
|
| 788 |
options |= ORTA_ASBR; |
| 789 |
type = ORT_ROUTER; |
| 790 |
} |
| 791 |
|
| 792 |
/* 16.2. (1b) */
|
| 793 |
if (metric == LSINFINITY)
|
| 794 |
continue;
|
| 795 |
|
| 796 |
/* 16.2. (4) */
|
| 797 |
net_addr_ip4 nrid = net_from_rid(en->lsa.rt); |
| 798 |
abr = fib_find(&oa->rtr, (net_addr *) &nrid); |
| 799 |
if (!abr || !abr->n.type)
|
| 800 |
continue;
|
| 801 |
|
| 802 |
if (!(abr->n.options & ORTA_ABR))
|
| 803 |
continue;
|
| 804 |
|
| 805 |
/* This check is not mentioned in RFC 2328 */
|
| 806 |
if (abr->n.type != RTS_OSPF)
|
| 807 |
continue;
|
| 808 |
|
| 809 |
/* 16.2. (5) */
|
| 810 |
orta nf = {
|
| 811 |
.type = RTS_OSPF_IA, |
| 812 |
.options = options, |
| 813 |
.metric1 = abr->n.metric1 + metric, |
| 814 |
.metric2 = LSINFINITY, |
| 815 |
.tag = 0,
|
| 816 |
.rid = en->lsa.rt, /* ABR ID */
|
| 817 |
.oa = oa, |
| 818 |
.nhs = abr->n.nhs |
| 819 |
}; |
| 820 |
|
| 821 |
if (type == ORT_NET)
|
| 822 |
ri_install_net(p, &net, &nf); |
| 823 |
else
|
| 824 |
ri_install_rt(oa, dst_rid, &nf); |
| 825 |
} |
| 826 |
} |
| 827 |
|
| 828 |
/* RFC 2328 16.3. examining summary-LSAs in transit areas */
|
| 829 |
static void |
| 830 |
ospf_rt_sum_tr(struct ospf_area *oa)
|
| 831 |
{
|
| 832 |
struct ospf_proto *p = oa->po;
|
| 833 |
struct ospf_area *bb = p->backbone;
|
| 834 |
struct top_hash_entry *en;
|
| 835 |
ort *re, *abr; |
| 836 |
u32 metric; |
| 837 |
|
| 838 |
if (!bb)
|
| 839 |
return;
|
| 840 |
|
| 841 |
WALK_SLIST(en, p->lsal) |
| 842 |
{
|
| 843 |
if ((en->lsa_type != LSA_T_SUM_RT) && (en->lsa_type != LSA_T_SUM_NET))
|
| 844 |
continue;
|
| 845 |
|
| 846 |
if (en->domain != oa->areaid)
|
| 847 |
continue;
|
| 848 |
|
| 849 |
/* 16.3 (1a) */
|
| 850 |
if (en->lsa.age == LSA_MAXAGE)
|
| 851 |
continue;
|
| 852 |
|
| 853 |
/* 16.3 (2) */
|
| 854 |
if (en->lsa.rt == p->router_id)
|
| 855 |
continue;
|
| 856 |
|
| 857 |
if (en->lsa_type == LSA_T_SUM_NET)
|
| 858 |
{
|
| 859 |
net_addr net; |
| 860 |
u8 pxopts; |
| 861 |
|
| 862 |
lsa_parse_sum_net(en, ospf_is_v2(p), &net, &pxopts, &metric); |
| 863 |
|
| 864 |
if (!ospf_valid_prefix(&net))
|
| 865 |
{
|
| 866 |
log(L_WARN "%s: Invalid prefix in LSA (Type: %04x, Id: %R, Rt: %R)",
|
| 867 |
p->p.name, en->lsa_type, en->lsa.id, en->lsa.rt); |
| 868 |
continue;
|
| 869 |
} |
| 870 |
|
| 871 |
if (pxopts & OPT_PX_NU)
|
| 872 |
continue;
|
| 873 |
|
| 874 |
re = fib_find(&p->rtf, &net); |
| 875 |
} |
| 876 |
else // en->lsa_type == LSA_T_SUM_RT |
| 877 |
{
|
| 878 |
u32 dst_rid, options; |
| 879 |
|
| 880 |
lsa_parse_sum_rt(en, ospf_is_v2(p), &dst_rid, &metric, &options); |
| 881 |
|
| 882 |
net_addr_ip4 nrid = net_from_rid(dst_rid); |
| 883 |
re = fib_find(&bb->rtr, (net_addr *) &nrid); |
| 884 |
} |
| 885 |
|
| 886 |
/* 16.3 (1b) */
|
| 887 |
if (metric == LSINFINITY)
|
| 888 |
continue;
|
| 889 |
|
| 890 |
/* 16.3 (3) */
|
| 891 |
if (!re || !re->n.type)
|
| 892 |
continue;
|
| 893 |
|
| 894 |
if (re->n.oa->areaid != 0) |
| 895 |
continue;
|
| 896 |
|
| 897 |
if ((re->n.type != RTS_OSPF) && (re->n.type != RTS_OSPF_IA))
|
| 898 |
continue;
|
| 899 |
|
| 900 |
/* 16.3. (4) */
|
| 901 |
net_addr_ip4 nrid = net_from_rid(en->lsa.rt); |
| 902 |
abr = fib_find(&oa->rtr, (net_addr *) &nrid); |
| 903 |
if (!abr || !abr->n.type)
|
| 904 |
continue;
|
| 905 |
|
| 906 |
metric = abr->n.metric1 + metric; /* IAC */
|
| 907 |
|
| 908 |
/* 16.3. (5) */
|
| 909 |
if ((metric < re->n.metric1) ||
|
| 910 |
((metric == re->n.metric1) && unresolved_vlink(re))) |
| 911 |
{
|
| 912 |
/* We want to replace the next-hop even if the metric is equal
|
| 913 |
to replace a virtual next-hop through vlink with a real one.
|
| 914 |
Proper ECMP would merge nexthops here, but we do not do that.
|
| 915 |
We restrict nexthops to fit one area to simplify check
|
| 916 |
12.4.3 p4 in decide_sum_lsa() */
|
| 917 |
|
| 918 |
re->n.metric1 = metric; |
| 919 |
re->n.voa = oa; |
| 920 |
re->n.nhs = abr->n.nhs; |
| 921 |
} |
| 922 |
} |
| 923 |
} |
| 924 |
|
| 925 |
/* Decide about originating or flushing summary LSAs for condensed area networks */
|
| 926 |
static int |
| 927 |
decide_anet_lsa(struct ospf_area *oa, struct area_net *anet, struct ospf_area *anet_oa) |
| 928 |
{
|
| 929 |
/* 12.4.3.1. - for stub/NSSA areas, originating summary routes is configurable */
|
| 930 |
if (!oa_is_ext(oa) && !oa->ac->summary)
|
| 931 |
return 0; |
| 932 |
|
| 933 |
if (oa == anet_oa)
|
| 934 |
return 0; |
| 935 |
|
| 936 |
/* Do not condense routing info when exporting from backbone to the transit area */
|
| 937 |
if ((anet_oa == oa->po->backbone) && oa->trcap)
|
| 938 |
return 0; |
| 939 |
|
| 940 |
return (anet->active && !anet->hidden);
|
| 941 |
} |
| 942 |
|
| 943 |
/* Decide about originating or flushing summary LSAs (12.4.3) */
|
| 944 |
static int |
| 945 |
decide_sum_lsa(struct ospf_area *oa, ort *nf, int dest) |
| 946 |
{
|
| 947 |
/* 12.4.3.1. - for stub/NSSA areas, originating summary routes is configurable */
|
| 948 |
if (!oa_is_ext(oa) && !oa->ac->summary)
|
| 949 |
return 0; |
| 950 |
|
| 951 |
/* Invalid field - no route */
|
| 952 |
if (!nf->n.type)
|
| 953 |
return 0; |
| 954 |
|
| 955 |
/* 12.4.3 p2 */
|
| 956 |
if (nf->n.type > RTS_OSPF_IA)
|
| 957 |
return 0; |
| 958 |
|
| 959 |
/* 12.4.3 p3 */
|
| 960 |
if ((nf->n.oa->areaid == oa->areaid))
|
| 961 |
return 0; |
| 962 |
|
| 963 |
/* 12.4.3 p4 */
|
| 964 |
if (nf->n.voa && (nf->n.voa->areaid == oa->areaid))
|
| 965 |
return 0; |
| 966 |
|
| 967 |
/* 12.4.3 p5 */
|
| 968 |
if (nf->n.metric1 >= LSINFINITY)
|
| 969 |
return 0; |
| 970 |
|
| 971 |
/* 12.4.3 p6 - AS boundary router */
|
| 972 |
if (dest == ORT_ROUTER)
|
| 973 |
{
|
| 974 |
/* We call decide_sum_lsa() on preferred ASBR entries, no need for 16.4. (3) */
|
| 975 |
/* 12.4.3 p1 */
|
| 976 |
return oa_is_ext(oa) && (nf->n.options & ORTA_ASBR);
|
| 977 |
} |
| 978 |
|
| 979 |
/* 12.4.3 p7 - inter-area route */
|
| 980 |
if (nf->n.type == RTS_OSPF_IA)
|
| 981 |
{
|
| 982 |
/* Inter-area routes are not repropagated into the backbone */
|
| 983 |
return (oa != oa->po->backbone);
|
| 984 |
} |
| 985 |
|
| 986 |
/* 12.4.3 p8 - intra-area route */
|
| 987 |
|
| 988 |
/* Do not condense routing info when exporting from backbone to the transit area */
|
| 989 |
if ((nf->n.oa == oa->po->backbone) && oa->trcap)
|
| 990 |
return 1; |
| 991 |
|
| 992 |
struct area_net *anet = (struct area_net *) |
| 993 |
fib_route(&nf->n.oa->net_fib, nf->fn.addr); |
| 994 |
|
| 995 |
/* Condensed area network found */
|
| 996 |
if (anet)
|
| 997 |
return 0; |
| 998 |
|
| 999 |
return 1; |
| 1000 |
} |
| 1001 |
|
| 1002 |
/* RFC 2328 16.7. p1 - originate or flush summary LSAs */
|
| 1003 |
static inline void |
| 1004 |
check_sum_net_lsa(struct ospf_proto *p, ort *nf)
|
| 1005 |
{
|
| 1006 |
struct area_net *anet = NULL; |
| 1007 |
struct ospf_area *anet_oa = NULL; |
| 1008 |
|
| 1009 |
if (nf->area_net)
|
| 1010 |
{
|
| 1011 |
/* It is a default route for stub areas, handled entirely in ospf_rt_abr() */
|
| 1012 |
if (nf->fn.addr->pxlen == 0) |
| 1013 |
return;
|
| 1014 |
|
| 1015 |
/* Find that area network */
|
| 1016 |
WALK_LIST(anet_oa, p->area_list) |
| 1017 |
{
|
| 1018 |
anet = fib_find(&anet_oa->net_fib, nf->fn.addr); |
| 1019 |
if (anet)
|
| 1020 |
break;
|
| 1021 |
} |
| 1022 |
} |
| 1023 |
|
| 1024 |
struct ospf_area *oa;
|
| 1025 |
WALK_LIST(oa, p->area_list) |
| 1026 |
{
|
| 1027 |
if (anet && decide_anet_lsa(oa, anet, anet_oa))
|
| 1028 |
ospf_originate_sum_net_lsa(p, oa, nf, anet->metric); |
| 1029 |
else if (decide_sum_lsa(oa, nf, ORT_NET)) |
| 1030 |
ospf_originate_sum_net_lsa(p, oa, nf, nf->n.metric1); |
| 1031 |
} |
| 1032 |
} |
| 1033 |
|
| 1034 |
static inline void |
| 1035 |
check_sum_rt_lsa(struct ospf_proto *p, ort *nf)
|
| 1036 |
{
|
| 1037 |
u32 rid = rid_from_net(nf->fn.addr); |
| 1038 |
|
| 1039 |
struct ospf_area *oa;
|
| 1040 |
WALK_LIST(oa, p->area_list) |
| 1041 |
if (decide_sum_lsa(oa, nf, ORT_ROUTER))
|
| 1042 |
ospf_originate_sum_rt_lsa(p, oa, rid, nf->n.metric1, nf->n.options); |
| 1043 |
} |
| 1044 |
|
| 1045 |
static inline int |
| 1046 |
decide_nssa_lsa(struct ospf_proto *p, ort *nf, struct ospf_lsa_ext_local *rt) |
| 1047 |
{
|
| 1048 |
struct ospf_area *oa = nf->n.oa;
|
| 1049 |
struct top_hash_entry *en = nf->n.en;
|
| 1050 |
|
| 1051 |
if (!rt_is_nssa(nf) || !oa->translate)
|
| 1052 |
return 0; |
| 1053 |
|
| 1054 |
/* Condensed area network found */
|
| 1055 |
if (fib_route(&oa->enet_fib, nf->fn.addr))
|
| 1056 |
return 0; |
| 1057 |
|
| 1058 |
if (!en || (en->lsa_type != LSA_T_NSSA))
|
| 1059 |
return 0; |
| 1060 |
|
| 1061 |
/* We do not store needed data in struct orta, we have to parse the LSA */
|
| 1062 |
lsa_parse_ext(en, ospf_is_v2(p), rt); |
| 1063 |
|
| 1064 |
if (rt->pxopts & OPT_PX_NU)
|
| 1065 |
return 0; |
| 1066 |
|
| 1067 |
if (!rt->propagate || ipa_zero(rt->fwaddr))
|
| 1068 |
return 0; |
| 1069 |
|
| 1070 |
return 1; |
| 1071 |
} |
| 1072 |
|
| 1073 |
/* RFC 3103 3.2 - translating Type-7 LSAs into Type-5 LSAs */
|
| 1074 |
static inline void |
| 1075 |
check_nssa_lsa(struct ospf_proto *p, ort *nf)
|
| 1076 |
{
|
| 1077 |
struct area_net *anet = NULL; |
| 1078 |
struct ospf_area *oa = NULL; |
| 1079 |
struct ospf_lsa_ext_local rt;
|
| 1080 |
|
| 1081 |
/* Do not translate LSA if there is already the external LSA from route export */
|
| 1082 |
if (nf->external_rte)
|
| 1083 |
return;
|
| 1084 |
|
| 1085 |
if (nf->area_net)
|
| 1086 |
{
|
| 1087 |
/* Find that area network */
|
| 1088 |
WALK_LIST(oa, p->area_list) |
| 1089 |
{
|
| 1090 |
anet = fib_find(&oa->enet_fib, nf->fn.addr); |
| 1091 |
if (anet)
|
| 1092 |
break;
|
| 1093 |
} |
| 1094 |
} |
| 1095 |
|
| 1096 |
/* RFC 3103 3.2 (3) - originate the aggregated address range */
|
| 1097 |
if (anet && anet->active && !anet->hidden && oa->translate)
|
| 1098 |
ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, anet->metric,
|
| 1099 |
(anet->metric & LSA_EXT3_EBIT), IPA_NONE, anet->tag, 0);
|
| 1100 |
|
| 1101 |
/* RFC 3103 3.2 (2) - originate the same network */
|
| 1102 |
else if (decide_nssa_lsa(p, nf, &rt)) |
| 1103 |
ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, rt.metric, rt.ebit, rt.fwaddr, rt.tag, 0); |
| 1104 |
} |
| 1105 |
|
| 1106 |
/* RFC 2328 16.7. p2 - find new/lost vlink endpoints */
|
| 1107 |
static void |
| 1108 |
ospf_check_vlinks(struct ospf_proto *p)
|
| 1109 |
{
|
| 1110 |
struct ospf_iface *ifa;
|
| 1111 |
WALK_LIST(ifa, p->iface_list) |
| 1112 |
{
|
| 1113 |
if (ifa->type == OSPF_IT_VLINK)
|
| 1114 |
{
|
| 1115 |
struct top_hash_entry *tmp;
|
| 1116 |
tmp = ospf_hash_find_rt(p->gr, ifa->voa->areaid, ifa->vid); |
| 1117 |
|
| 1118 |
if (tmp && (tmp->color == INSPF) && ipa_nonzero(tmp->lb) && tmp->nhs)
|
| 1119 |
{
|
| 1120 |
struct ospf_iface *nhi = ospf_iface_find(p, tmp->nhs->iface);
|
| 1121 |
|
| 1122 |
if ((ifa->state != OSPF_IS_PTP)
|
| 1123 |
|| (ifa->vifa != nhi) |
| 1124 |
|| !ipa_equal(ifa->vip, tmp->lb)) |
| 1125 |
{
|
| 1126 |
OSPF_TRACE(D_EVENTS, "Vlink peer %R found", ifa->vid);
|
| 1127 |
ospf_iface_sm(ifa, ISM_DOWN); |
| 1128 |
ifa->vifa = nhi; |
| 1129 |
ifa->addr = nhi->addr; |
| 1130 |
ifa->cost = tmp->dist; |
| 1131 |
ifa->vip = tmp->lb; |
| 1132 |
ospf_iface_sm(ifa, ISM_UP); |
| 1133 |
} |
| 1134 |
else if ((ifa->state == OSPF_IS_PTP) && (ifa->cost != tmp->dist)) |
| 1135 |
{
|
| 1136 |
ifa->cost = tmp->dist; |
| 1137 |
|
| 1138 |
/* RFC 2328 12.4 Event 8 - vlink state change */
|
| 1139 |
ospf_notify_rt_lsa(ifa->oa); |
| 1140 |
} |
| 1141 |
} |
| 1142 |
else
|
| 1143 |
{
|
| 1144 |
if (ifa->state > OSPF_IS_DOWN)
|
| 1145 |
{
|
| 1146 |
OSPF_TRACE(D_EVENTS, "Vlink peer %R lost", ifa->vid);
|
| 1147 |
ospf_iface_sm(ifa, ISM_DOWN); |
| 1148 |
} |
| 1149 |
} |
| 1150 |
} |
| 1151 |
} |
| 1152 |
} |
| 1153 |
|
| 1154 |
|
| 1155 |
/* Miscellaneous route processing that needs to be done by ABRs */
|
| 1156 |
static void |
| 1157 |
ospf_rt_abr1(struct ospf_proto *p)
|
| 1158 |
{
|
| 1159 |
struct area_net *anet;
|
| 1160 |
ort *default_nf; |
| 1161 |
net_addr default_net; |
| 1162 |
|
| 1163 |
/* RFC 2328 G.3 - incomplete resolution of virtual next hops - routers */
|
| 1164 |
FIB_WALK(&p->backbone->rtr, ort, nf) |
| 1165 |
{
|
| 1166 |
if (nf->n.type && unresolved_vlink(nf))
|
| 1167 |
reset_ri(nf); |
| 1168 |
} |
| 1169 |
FIB_WALK_END; |
| 1170 |
|
| 1171 |
|
| 1172 |
FIB_WALK(&p->rtf, ort, nf) |
| 1173 |
{
|
| 1174 |
/* RFC 2328 G.3 - incomplete resolution of virtual next hops - networks */
|
| 1175 |
if (nf->n.type && unresolved_vlink(nf))
|
| 1176 |
reset_ri(nf); |
| 1177 |
|
| 1178 |
|
| 1179 |
/* Compute condensed area networks */
|
| 1180 |
if (nf->n.type == RTS_OSPF)
|
| 1181 |
{
|
| 1182 |
anet = (struct area_net *) fib_route(&nf->n.oa->net_fib, nf->fn.addr);
|
| 1183 |
if (anet)
|
| 1184 |
{
|
| 1185 |
if (!anet->active)
|
| 1186 |
{
|
| 1187 |
anet->active = 1;
|
| 1188 |
|
| 1189 |
/* Get a RT entry and mark it to know that it is an area network */
|
| 1190 |
ort *nfi = fib_get(&p->rtf, anet->fn.addr); |
| 1191 |
nfi->area_net = 1;
|
| 1192 |
|
| 1193 |
/* 16.2. (3) */
|
| 1194 |
if (nfi->n.type == RTS_OSPF_IA)
|
| 1195 |
reset_ri(nfi); |
| 1196 |
} |
| 1197 |
|
| 1198 |
if (anet->metric < nf->n.metric1)
|
| 1199 |
anet->metric = nf->n.metric1; |
| 1200 |
} |
| 1201 |
} |
| 1202 |
} |
| 1203 |
FIB_WALK_END; |
| 1204 |
|
| 1205 |
|
| 1206 |
if (ospf_is_v2(p))
|
| 1207 |
net_fill_ip4(&default_net, IP4_NONE, 0);
|
| 1208 |
else
|
| 1209 |
net_fill_ip6(&default_net, IP6_NONE, 0);
|
| 1210 |
|
| 1211 |
default_nf = fib_get(&p->rtf, &default_net); |
| 1212 |
default_nf->area_net = 1;
|
| 1213 |
|
| 1214 |
struct ospf_area *oa;
|
| 1215 |
WALK_LIST(oa, p->area_list) |
| 1216 |
{
|
| 1217 |
|
| 1218 |
/* 12.4.3.1. - originate or flush default route for stub/NSSA areas */
|
| 1219 |
if (oa_is_stub(oa) || (oa_is_nssa(oa) && !oa->ac->summary))
|
| 1220 |
ospf_originate_sum_net_lsa(p, oa, default_nf, oa->ac->default_cost); |
| 1221 |
|
| 1222 |
/*
|
| 1223 |
* Originate type-7 default route for NSSA areas
|
| 1224 |
*
|
| 1225 |
* Because type-7 default LSAs are originated by ABRs, they do not
|
| 1226 |
* collide with other type-7 LSAs (as ABRs generate type-5 LSAs
|
| 1227 |
* for both external route export or external-NSSA translation),
|
| 1228 |
* so we use 0 for the src arg.
|
| 1229 |
*/
|
| 1230 |
|
| 1231 |
if (oa_is_nssa(oa) && oa->ac->default_nssa)
|
| 1232 |
ospf_originate_ext_lsa(p, oa, default_nf, LSA_M_RTCALC, oa->ac->default_cost, |
| 1233 |
(oa->ac->default_cost & LSA_EXT3_EBIT), IPA_NONE, 0, 0); |
| 1234 |
|
| 1235 |
/* RFC 2328 16.4. (3) - precompute preferred ASBR entries */
|
| 1236 |
if (oa_is_ext(oa))
|
| 1237 |
{
|
| 1238 |
FIB_WALK(&oa->rtr, ort, nf) |
| 1239 |
{
|
| 1240 |
if (nf->n.options & ORTA_ASBR)
|
| 1241 |
ri_install_asbr(p, rid_from_net(nf->fn.addr), &nf->n); |
| 1242 |
} |
| 1243 |
FIB_WALK_END; |
| 1244 |
} |
| 1245 |
} |
| 1246 |
|
| 1247 |
|
| 1248 |
/* Originate or flush ASBR summary LSAs */
|
| 1249 |
FIB_WALK(&p->backbone->rtr, ort, nf) |
| 1250 |
{
|
| 1251 |
check_sum_rt_lsa(p, nf); |
| 1252 |
} |
| 1253 |
FIB_WALK_END; |
| 1254 |
|
| 1255 |
|
| 1256 |
/* RFC 2328 16.7. p2 - find new/lost vlink endpoints */
|
| 1257 |
ospf_check_vlinks(p); |
| 1258 |
} |
| 1259 |
|
| 1260 |
|
| 1261 |
static void |
| 1262 |
translator_timer_hook(timer *timer) |
| 1263 |
{
|
| 1264 |
struct ospf_area *oa = timer->data;
|
| 1265 |
|
| 1266 |
if (oa->translate != TRANS_WAIT)
|
| 1267 |
return;
|
| 1268 |
|
| 1269 |
oa->translate = TRANS_OFF; |
| 1270 |
ospf_schedule_rtcalc(oa->po); |
| 1271 |
} |
| 1272 |
|
| 1273 |
static void |
| 1274 |
ospf_rt_abr2(struct ospf_proto *p)
|
| 1275 |
{
|
| 1276 |
struct ospf_area *oa;
|
| 1277 |
struct top_hash_entry *en;
|
| 1278 |
|
| 1279 |
/* RFC 3103 3.1 - type-7 translator election */
|
| 1280 |
struct ospf_area *bb = p->backbone;
|
| 1281 |
WALK_LIST(oa, p->area_list) |
| 1282 |
if (oa_is_nssa(oa))
|
| 1283 |
{
|
| 1284 |
int translate = 1; |
| 1285 |
|
| 1286 |
if (oa->ac->translator)
|
| 1287 |
goto decided;
|
| 1288 |
|
| 1289 |
FIB_WALK(&oa->rtr, ort, nf) |
| 1290 |
{
|
| 1291 |
if (!nf->n.type || !(nf->n.options & ORTA_ABR))
|
| 1292 |
continue;
|
| 1293 |
|
| 1294 |
ort *nf2 = fib_find(&bb->rtr, nf->fn.addr); |
| 1295 |
if (!nf2 || !nf2->n.type || !(nf2->n.options & ORTA_ABR))
|
| 1296 |
continue;
|
| 1297 |
|
| 1298 |
en = ospf_hash_find_rt(p->gr, oa->areaid, nf->n.rid); |
| 1299 |
if (!en || (en->color != INSPF))
|
| 1300 |
continue;
|
| 1301 |
|
| 1302 |
struct ospf_lsa_rt *rt = en->lsa_body;
|
| 1303 |
/* There is better candidate - Nt-bit or higher Router ID */
|
| 1304 |
if ((rt->options & OPT_RT_NT) || (p->router_id < nf->n.rid))
|
| 1305 |
{
|
| 1306 |
translate = 0;
|
| 1307 |
goto decided;
|
| 1308 |
} |
| 1309 |
} |
| 1310 |
FIB_WALK_END; |
| 1311 |
|
| 1312 |
decided:
|
| 1313 |
if (translate && (oa->translate != TRANS_ON))
|
| 1314 |
{
|
| 1315 |
if (oa->translate == TRANS_WAIT)
|
| 1316 |
tm_stop(oa->translator_timer); |
| 1317 |
|
| 1318 |
oa->translate = TRANS_ON; |
| 1319 |
} |
| 1320 |
|
| 1321 |
if (!translate && (oa->translate == TRANS_ON))
|
| 1322 |
{
|
| 1323 |
if (oa->translator_timer == NULL) |
| 1324 |
oa->translator_timer = tm_new_set(p->p.pool, translator_timer_hook, oa, 0, 0); |
| 1325 |
|
| 1326 |
/* Schedule the end of translation */
|
| 1327 |
tm_start(oa->translator_timer, oa->ac->transint); |
| 1328 |
oa->translate = TRANS_WAIT; |
| 1329 |
} |
| 1330 |
} |
| 1331 |
|
| 1332 |
|
| 1333 |
/* Compute condensed external networks */
|
| 1334 |
FIB_WALK(&p->rtf, ort, nf) |
| 1335 |
{
|
| 1336 |
if (rt_is_nssa(nf) && (nf->n.options & ORTA_PROP))
|
| 1337 |
{
|
| 1338 |
struct area_net *anet = fib_route(&nf->n.oa->enet_fib, nf->fn.addr);
|
| 1339 |
|
| 1340 |
if (anet)
|
| 1341 |
{
|
| 1342 |
if (!anet->active)
|
| 1343 |
{
|
| 1344 |
anet->active = 1;
|
| 1345 |
|
| 1346 |
/* Get a RT entry and mark it to know that it is an area network */
|
| 1347 |
ort *nf2 = fib_get(&p->rtf, anet->fn.addr); |
| 1348 |
nf2->area_net = 1;
|
| 1349 |
} |
| 1350 |
|
| 1351 |
u32 metric = (nf->n.type == RTS_OSPF_EXT1) ? |
| 1352 |
nf->n.metric1 : ((nf->n.metric2 + 1) | LSA_EXT3_EBIT);
|
| 1353 |
|
| 1354 |
if (anet->metric < metric)
|
| 1355 |
anet->metric = metric; |
| 1356 |
} |
| 1357 |
} |
| 1358 |
} |
| 1359 |
FIB_WALK_END; |
| 1360 |
|
| 1361 |
|
| 1362 |
FIB_WALK(&p->rtf, ort, nf) |
| 1363 |
{
|
| 1364 |
check_sum_net_lsa(p, nf); |
| 1365 |
check_nssa_lsa(p, nf); |
| 1366 |
} |
| 1367 |
FIB_WALK_END; |
| 1368 |
} |
| 1369 |
|
| 1370 |
|
| 1371 |
/* Like fib_route(), but ignores dummy rt entries */
|
| 1372 |
static void * |
| 1373 |
ospf_fib_route_ip4(struct fib *f, ip4_addr a, int len) |
| 1374 |
{
|
| 1375 |
net_addr_ip4 net = NET_ADDR_IP4(a, len); |
| 1376 |
ort *nf; |
| 1377 |
|
| 1378 |
loop:
|
| 1379 |
nf = fib_find(f, (net_addr *) &net); |
| 1380 |
if (nf && nf->n.type)
|
| 1381 |
return nf;
|
| 1382 |
|
| 1383 |
if (net.pxlen > 0) |
| 1384 |
{
|
| 1385 |
net.pxlen--; |
| 1386 |
ip4_clrbit(&net.prefix, net.pxlen); |
| 1387 |
goto loop;
|
| 1388 |
} |
| 1389 |
|
| 1390 |
return NULL; |
| 1391 |
} |
| 1392 |
|
| 1393 |
static void * |
| 1394 |
ospf_fib_route_ip6(struct fib *f, ip6_addr a, int len) |
| 1395 |
{
|
| 1396 |
net_addr_ip6 net = NET_ADDR_IP6(a, len); |
| 1397 |
ort *nf; |
| 1398 |
|
| 1399 |
loop:
|
| 1400 |
nf = fib_find(f, (net_addr *) &net); |
| 1401 |
if (nf && nf->n.type)
|
| 1402 |
return nf;
|
| 1403 |
|
| 1404 |
if (net.pxlen > 0) |
| 1405 |
{
|
| 1406 |
net.pxlen--; |
| 1407 |
ip6_clrbit(&net.prefix, net.pxlen); |
| 1408 |
goto loop;
|
| 1409 |
} |
| 1410 |
|
| 1411 |
return NULL; |
| 1412 |
} |
| 1413 |
|
| 1414 |
static void * |
| 1415 |
ospf_fib_route(struct fib *f, ip_addr a)
|
| 1416 |
{
|
| 1417 |
if (f->addr_type == NET_IP4)
|
| 1418 |
return ospf_fib_route_ip4(f, ipa_to_ip4(a), IP4_MAX_PREFIX_LENGTH);
|
| 1419 |
else
|
| 1420 |
return ospf_fib_route_ip6(f, ipa_to_ip6(a), IP6_MAX_PREFIX_LENGTH);
|
| 1421 |
} |
| 1422 |
|
| 1423 |
|
| 1424 |
/* RFC 2328 16.4. calculating external routes */
|
| 1425 |
static void |
| 1426 |
ospf_ext_spf(struct ospf_proto *p)
|
| 1427 |
{
|
| 1428 |
struct top_hash_entry *en;
|
| 1429 |
struct ospf_lsa_ext_local rt;
|
| 1430 |
ort *nf1, *nf2; |
| 1431 |
orta nfa = {};
|
| 1432 |
u32 br_metric; |
| 1433 |
struct ospf_area *atmp;
|
| 1434 |
|
| 1435 |
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for ext routes");
|
| 1436 |
|
| 1437 |
WALK_SLIST(en, p->lsal) |
| 1438 |
{
|
| 1439 |
/* 16.4. (1) */
|
| 1440 |
if ((en->lsa_type != LSA_T_EXT) && (en->lsa_type != LSA_T_NSSA))
|
| 1441 |
continue;
|
| 1442 |
|
| 1443 |
if (en->lsa.age == LSA_MAXAGE)
|
| 1444 |
continue;
|
| 1445 |
|
| 1446 |
/* 16.4. (2) */
|
| 1447 |
if (en->lsa.rt == p->router_id)
|
| 1448 |
continue;
|
| 1449 |
|
| 1450 |
DBG("%s: Working on LSA. ID: %R, RT: %R, Type: %u\n",
|
| 1451 |
p->p.name, en->lsa.id, en->lsa.rt, en->lsa_type); |
| 1452 |
|
| 1453 |
lsa_parse_ext(en, ospf_is_v2(p), &rt); |
| 1454 |
|
| 1455 |
if (!ospf_valid_prefix(&rt.net))
|
| 1456 |
{
|
| 1457 |
log(L_WARN "%s: Invalid prefix in LSA (Type: %04x, Id: %R, Rt: %R)",
|
| 1458 |
p->p.name, en->lsa_type, en->lsa.id, en->lsa.rt); |
| 1459 |
continue;
|
| 1460 |
} |
| 1461 |
|
| 1462 |
if (rt.metric == LSINFINITY)
|
| 1463 |
continue;
|
| 1464 |
|
| 1465 |
if (rt.pxopts & OPT_PX_NU)
|
| 1466 |
continue;
|
| 1467 |
|
| 1468 |
/* 16.4. (3) */
|
| 1469 |
/* If there are more areas, we already precomputed preferred ASBR
|
| 1470 |
entries in ospf_rt_abr1() and stored them in the backbone
|
| 1471 |
table. For NSSA, we examine the area to which the LSA is assigned */
|
| 1472 |
if (en->lsa_type == LSA_T_EXT)
|
| 1473 |
atmp = ospf_main_area(p); |
| 1474 |
else /* NSSA */ |
| 1475 |
atmp = ospf_find_area(p, en->domain); |
| 1476 |
|
| 1477 |
if (!atmp)
|
| 1478 |
continue; /* Should not happen */ |
| 1479 |
|
| 1480 |
net_addr_ip4 nrid = net_from_rid(en->lsa.rt); |
| 1481 |
nf1 = fib_find(&atmp->rtr, (net_addr *) &nrid); |
| 1482 |
|
| 1483 |
if (!nf1 || !nf1->n.type)
|
| 1484 |
continue; /* No AS boundary router found */ |
| 1485 |
|
| 1486 |
if (!(nf1->n.options & ORTA_ASBR))
|
| 1487 |
continue; /* It is not ASBR */ |
| 1488 |
|
| 1489 |
/* 16.4. (3) NSSA - special rule for default routes */
|
| 1490 |
/* ABR should use default only if P-bit is set and summaries are active */
|
| 1491 |
if ((en->lsa_type == LSA_T_NSSA) && (rt.net.pxlen == 0) && |
| 1492 |
(p->areano > 1) && !(rt.propagate && atmp->ac->summary))
|
| 1493 |
continue;
|
| 1494 |
|
| 1495 |
if (!rt.fbit)
|
| 1496 |
{
|
| 1497 |
nf2 = nf1; |
| 1498 |
nfa.nhs = nf1->n.nhs; |
| 1499 |
br_metric = nf1->n.metric1; |
| 1500 |
} |
| 1501 |
else
|
| 1502 |
{
|
| 1503 |
nf2 = ospf_fib_route(&p->rtf, rt.fwaddr); |
| 1504 |
if (!nf2)
|
| 1505 |
continue;
|
| 1506 |
|
| 1507 |
if (en->lsa_type == LSA_T_EXT)
|
| 1508 |
{
|
| 1509 |
/* For ext routes, we accept intra-area or inter-area routes */
|
| 1510 |
if ((nf2->n.type != RTS_OSPF) && (nf2->n.type != RTS_OSPF_IA))
|
| 1511 |
continue;
|
| 1512 |
} |
| 1513 |
else /* NSSA */ |
| 1514 |
{
|
| 1515 |
/* For NSSA routes, we accept just intra-area in the same area */
|
| 1516 |
if ((nf2->n.type != RTS_OSPF) || (nf2->n.oa != atmp))
|
| 1517 |
continue;
|
| 1518 |
} |
| 1519 |
|
| 1520 |
/* Next-hop is a part of a configured stubnet */
|
| 1521 |
if (!nf2->n.nhs)
|
| 1522 |
continue;
|
| 1523 |
|
| 1524 |
nfa.nhs = nf2->n.nhs; |
| 1525 |
br_metric = nf2->n.metric1; |
| 1526 |
|
| 1527 |
/* Replace device nexthops with nexthops to forwarding address from LSA */
|
| 1528 |
if (has_device_nexthops(nfa.nhs))
|
| 1529 |
{
|
| 1530 |
nfa.nhs = fix_device_nexthops(p, nfa.nhs, rt.fwaddr); |
| 1531 |
nfa.nhs_reuse = 1;
|
| 1532 |
} |
| 1533 |
} |
| 1534 |
|
| 1535 |
if (rt.ebit)
|
| 1536 |
{
|
| 1537 |
nfa.type = RTS_OSPF_EXT2; |
| 1538 |
nfa.metric1 = br_metric; |
| 1539 |
nfa.metric2 = rt.metric; |
| 1540 |
} |
| 1541 |
else
|
| 1542 |
{
|
| 1543 |
nfa.type = RTS_OSPF_EXT1; |
| 1544 |
nfa.metric1 = br_metric + rt.metric; |
| 1545 |
nfa.metric2 = LSINFINITY; |
| 1546 |
} |
| 1547 |
|
| 1548 |
/* Mark the LSA as reachable */
|
| 1549 |
en->color = INSPF; |
| 1550 |
|
| 1551 |
/* Whether the route is preferred in route selection according to 16.4.1 */
|
| 1552 |
nfa.options = epath_preferred(&nf2->n) ? ORTA_PREF : 0;
|
| 1553 |
if (en->lsa_type == LSA_T_NSSA)
|
| 1554 |
{
|
| 1555 |
nfa.options |= ORTA_NSSA; |
| 1556 |
if (rt.propagate)
|
| 1557 |
nfa.options |= ORTA_PROP; |
| 1558 |
} |
| 1559 |
|
| 1560 |
nfa.tag = rt.tag; |
| 1561 |
nfa.rid = en->lsa.rt; |
| 1562 |
nfa.oa = atmp; /* undefined in RFC 2328 */
|
| 1563 |
nfa.en = en; /* store LSA for later (NSSA processing) */
|
| 1564 |
|
| 1565 |
ri_install_ext(p, &rt.net, &nfa); |
| 1566 |
} |
| 1567 |
} |
| 1568 |
|
| 1569 |
/* Cleanup of routing tables and data */
|
| 1570 |
void
|
| 1571 |
ospf_rt_reset(struct ospf_proto *p)
|
| 1572 |
{
|
| 1573 |
struct ospf_area *oa;
|
| 1574 |
struct top_hash_entry *en;
|
| 1575 |
|
| 1576 |
/* Reset old routing table */
|
| 1577 |
FIB_WALK(&p->rtf, ort, ri) |
| 1578 |
{
|
| 1579 |
ri->area_net = 0;
|
| 1580 |
reset_ri(ri); |
| 1581 |
} |
| 1582 |
FIB_WALK_END; |
| 1583 |
|
| 1584 |
/* Reset SPF data in LSA db */
|
| 1585 |
WALK_SLIST(en, p->lsal) |
| 1586 |
{
|
| 1587 |
en->color = OUTSPF; |
| 1588 |
en->dist = LSINFINITY; |
| 1589 |
en->nhs = NULL;
|
| 1590 |
en->lb = IPA_NONE; |
| 1591 |
|
| 1592 |
if (en->mode == LSA_M_RTCALC)
|
| 1593 |
en->mode = LSA_M_STALE; |
| 1594 |
} |
| 1595 |
|
| 1596 |
WALK_LIST(oa, p->area_list) |
| 1597 |
{
|
| 1598 |
/* Reset ASBR routing tables */
|
| 1599 |
FIB_WALK(&oa->rtr, ort, ri) |
| 1600 |
{
|
| 1601 |
reset_ri(ri); |
| 1602 |
} |
| 1603 |
FIB_WALK_END; |
| 1604 |
|
| 1605 |
/* Reset condensed area networks */
|
| 1606 |
if (p->areano > 1) |
| 1607 |
{
|
| 1608 |
FIB_WALK(&oa->net_fib, struct area_net, anet)
|
| 1609 |
{
|
| 1610 |
anet->active = 0;
|
| 1611 |
anet->metric = 0;
|
| 1612 |
} |
| 1613 |
FIB_WALK_END; |
| 1614 |
|
| 1615 |
FIB_WALK(&oa->enet_fib, struct area_net, anet)
|
| 1616 |
{
|
| 1617 |
anet->active = 0;
|
| 1618 |
anet->metric = 0;
|
| 1619 |
} |
| 1620 |
FIB_WALK_END; |
| 1621 |
} |
| 1622 |
} |
| 1623 |
} |
| 1624 |
|
| 1625 |
/**
|
| 1626 |
* ospf_rt_spf - calculate internal routes
|
| 1627 |
* @p: OSPF protocol instance
|
| 1628 |
*
|
| 1629 |
* Calculation of internal paths in an area is described in 16.1 of RFC 2328.
|
| 1630 |
* It's based on Dijkstra's shortest path tree algorithms.
|
| 1631 |
* This function is invoked from ospf_disp().
|
| 1632 |
*/
|
| 1633 |
void
|
| 1634 |
ospf_rt_spf(struct ospf_proto *p)
|
| 1635 |
{
|
| 1636 |
struct ospf_area *oa;
|
| 1637 |
|
| 1638 |
if (p->areano == 0) |
| 1639 |
return;
|
| 1640 |
|
| 1641 |
OSPF_TRACE(D_EVENTS, "Starting routing table calculation");
|
| 1642 |
|
| 1643 |
/* 16. (1) */
|
| 1644 |
ospf_rt_reset(p); |
| 1645 |
|
| 1646 |
/* 16. (2) */
|
| 1647 |
WALK_LIST(oa, p->area_list) |
| 1648 |
ospf_rt_spfa(oa); |
| 1649 |
|
| 1650 |
/* 16. (3) */
|
| 1651 |
ospf_rt_sum(ospf_main_area(p)); |
| 1652 |
|
| 1653 |
/* 16. (4) */
|
| 1654 |
WALK_LIST(oa, p->area_list) |
| 1655 |
if (oa->trcap && (oa->areaid != 0)) |
| 1656 |
ospf_rt_sum_tr(oa); |
| 1657 |
|
| 1658 |
if (p->areano > 1) |
| 1659 |
ospf_rt_abr1(p); |
| 1660 |
|
| 1661 |
/* 16. (5) */
|
| 1662 |
ospf_ext_spf(p); |
| 1663 |
|
| 1664 |
if (p->areano > 1) |
| 1665 |
ospf_rt_abr2(p); |
| 1666 |
|
| 1667 |
rt_sync(p); |
| 1668 |
lp_flush(p->nhpool); |
| 1669 |
|
| 1670 |
p->calcrt = 0;
|
| 1671 |
} |
| 1672 |
|
| 1673 |
|
| 1674 |
static inline int |
| 1675 |
inherit_nexthops(struct nexthop *pn)
|
| 1676 |
{
|
| 1677 |
/* Proper nexthops (with defined GW) or dummy vlink nexthops (without iface) */
|
| 1678 |
return pn && (ipa_nonzero(pn->gw) || !pn->iface);
|
| 1679 |
} |
| 1680 |
|
| 1681 |
static struct nexthop * |
| 1682 |
calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en, |
| 1683 |
struct top_hash_entry *par, int pos) |
| 1684 |
{
|
| 1685 |
struct ospf_proto *p = oa->po;
|
| 1686 |
struct nexthop *pn = par->nhs;
|
| 1687 |
struct ospf_iface *ifa;
|
| 1688 |
u32 rid = en->lsa.rt; |
| 1689 |
|
| 1690 |
/* 16.1.1. The next hop calculation */
|
| 1691 |
DBG(" Next hop calculating for id: %R rt: %R type: %u\n",
|
| 1692 |
en->lsa.id, en->lsa.rt, en->lsa_type); |
| 1693 |
|
| 1694 |
/* Usually, we inherit parent nexthops */
|
| 1695 |
if (inherit_nexthops(pn))
|
| 1696 |
return pn;
|
| 1697 |
|
| 1698 |
/*
|
| 1699 |
* There are three cases:
|
| 1700 |
* 1) en is a local network (and par is root)
|
| 1701 |
* 2) en is a ptp or ptmp neighbor (and par is root)
|
| 1702 |
* 3) en is a bcast or nbma neighbor (and par is local network)
|
| 1703 |
*/
|
| 1704 |
|
| 1705 |
/* The first case - local network */
|
| 1706 |
if ((en->lsa_type == LSA_T_NET) && (par == oa->rt))
|
| 1707 |
{
|
| 1708 |
ifa = rt_pos_to_ifa(oa, pos); |
| 1709 |
if (!ifa)
|
| 1710 |
return NULL; |
| 1711 |
|
| 1712 |
return new_nexthop(p, IPA_NONE, ifa->iface, ifa->ecmp_weight);
|
| 1713 |
} |
| 1714 |
|
| 1715 |
/* The second case - ptp or ptmp neighbor */
|
| 1716 |
if ((en->lsa_type == LSA_T_RT) && (par == oa->rt))
|
| 1717 |
{
|
| 1718 |
ifa = rt_pos_to_ifa(oa, pos); |
| 1719 |
if (!ifa)
|
| 1720 |
return NULL; |
| 1721 |
|
| 1722 |
if (ifa->type == OSPF_IT_VLINK)
|
| 1723 |
return new_nexthop(p, IPA_NONE, NULL, 0); |
| 1724 |
|
| 1725 |
struct ospf_neighbor *m = find_neigh(ifa, rid);
|
| 1726 |
if (!m || (m->state != NEIGHBOR_FULL))
|
| 1727 |
return NULL; |
| 1728 |
|
| 1729 |
return new_nexthop(p, m->ip, ifa->iface, ifa->ecmp_weight);
|
| 1730 |
} |
| 1731 |
|
| 1732 |
/* The third case - bcast or nbma neighbor */
|
| 1733 |
if ((en->lsa_type == LSA_T_RT) && (par->lsa_type == LSA_T_NET))
|
| 1734 |
{
|
| 1735 |
/* par->nhi should be defined from parent's calc_next_hop() */
|
| 1736 |
if (!pn)
|
| 1737 |
goto bad;
|
| 1738 |
|
| 1739 |
if (ospf_is_v2(p))
|
| 1740 |
{
|
| 1741 |
/*
|
| 1742 |
* In this case, next-hop is the same as link-back, which is
|
| 1743 |
* already computed in link_back().
|
| 1744 |
*/
|
| 1745 |
if (ipa_zero(en->lb))
|
| 1746 |
goto bad;
|
| 1747 |
|
| 1748 |
return new_nexthop(p, en->lb, pn->iface, pn->weight);
|
| 1749 |
} |
| 1750 |
else /* OSPFv3 */ |
| 1751 |
{
|
| 1752 |
/*
|
| 1753 |
* Next-hop is taken from lladdr field of Link-LSA, en->lb_id
|
| 1754 |
* is computed in link_back().
|
| 1755 |
*/
|
| 1756 |
struct top_hash_entry *lhe;
|
| 1757 |
lhe = ospf_hash_find(p->gr, pn->iface->index, en->lb_id, rid, LSA_T_LINK); |
| 1758 |
|
| 1759 |
if (!lhe)
|
| 1760 |
return NULL; |
| 1761 |
|
| 1762 |
struct ospf_lsa_link *llsa = lhe->lsa_body;
|
| 1763 |
|
| 1764 |
if (ip6_zero(llsa->lladdr))
|
| 1765 |
return NULL; |
| 1766 |
|
| 1767 |
return new_nexthop(p, ipa_from_ip6(llsa->lladdr), pn->iface, pn->weight);
|
| 1768 |
} |
| 1769 |
} |
| 1770 |
|
| 1771 |
bad:
|
| 1772 |
/* Probably bug or some race condition, we log it */
|
| 1773 |
log(L_ERR "%s: Unexpected case in next hop calculation", p->p.name);
|
| 1774 |
return NULL; |
| 1775 |
} |
| 1776 |
|
| 1777 |
|
| 1778 |
/* Add LSA into list of candidates in Dijkstra's algorithm */
|
| 1779 |
static void |
| 1780 |
add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par, |
| 1781 |
u32 dist, struct ospf_area *oa, int pos) |
| 1782 |
{
|
| 1783 |
struct ospf_proto *p = oa->po;
|
| 1784 |
node *prev, *n; |
| 1785 |
int added = 0; |
| 1786 |
struct top_hash_entry *act;
|
| 1787 |
|
| 1788 |
/* 16.1. (2b) */
|
| 1789 |
if (en == NULL) |
| 1790 |
return;
|
| 1791 |
if (en->lsa.age == LSA_MAXAGE)
|
| 1792 |
return;
|
| 1793 |
|
| 1794 |
if (ospf_is_v3(p) && (en->lsa_type == LSA_T_RT))
|
| 1795 |
{
|
| 1796 |
/* In OSPFv3, check V6 flag */
|
| 1797 |
struct ospf_lsa_rt *rt = en->lsa_body;
|
| 1798 |
if (!(rt->options & OPT_V6))
|
| 1799 |
return;
|
| 1800 |
} |
| 1801 |
|
| 1802 |
/* 16.1. (2c) */
|
| 1803 |
if (en->color == INSPF)
|
| 1804 |
return;
|
| 1805 |
|
| 1806 |
/* 16.1. (2d), also checks that dist < LSINFINITY */
|
| 1807 |
if (dist > en->dist)
|
| 1808 |
return;
|
| 1809 |
|
| 1810 |
/* We should check whether there is a reverse link from en to par, */
|
| 1811 |
if (!link_back(oa, en, par))
|
| 1812 |
return;
|
| 1813 |
|
| 1814 |
struct nexthop *nhs = calc_next_hop(oa, en, par, pos);
|
| 1815 |
if (!nhs)
|
| 1816 |
{
|
| 1817 |
log(L_WARN "%s: Cannot find next hop for LSA (Type: %04x, Id: %R, Rt: %R)",
|
| 1818 |
p->p.name, en->lsa_type, en->lsa.id, en->lsa.rt); |
| 1819 |
return;
|
| 1820 |
} |
| 1821 |
|
| 1822 |
/* If en->dist > 0, we know that en->color == CANDIDATE and en->nhs is defined. */
|
| 1823 |
if ((dist == en->dist) && !nh_is_vlink(en->nhs))
|
| 1824 |
{
|
| 1825 |
/*
|
| 1826 |
* For multipath, we should merge nexthops. We merge regular nexthops only.
|
| 1827 |
* Dummy vlink nexthops are less preferred and handled as a special case.
|
| 1828 |
*
|
| 1829 |
* During merging, new nexthops (nhs) can be reused if they are not
|
| 1830 |
* inherited from the parent (i.e. they are allocated in calc_next_hop()).
|
| 1831 |
* Current nexthops (en->nhs) can be reused if they weren't inherited in
|
| 1832 |
* previous steps (that is stored in nhs_reuse, i.e. created by merging or
|
| 1833 |
* allocated in calc_next_hop()).
|
| 1834 |
*
|
| 1835 |
* Generally, a node first inherits shared nexthops from its parent and
|
| 1836 |
* later possibly gets reusable (private) copy during merging. This is more
|
| 1837 |
* or less same for both top_hash_entry nodes and orta nodes.
|
| 1838 |
*
|
| 1839 |
* Note that when a child inherits a private nexthop from its parent, it
|
| 1840 |
* should make the nexthop shared for both parent and child, while we only
|
| 1841 |
* update nhs_reuse for the child node. This makes nhs_reuse field for the
|
| 1842 |
* parent technically incorrect, but it is not a problem as parent's nhs
|
| 1843 |
* will not be modified (and nhs_reuse examined) afterwards.
|
| 1844 |
*/
|
| 1845 |
|
| 1846 |
/* Keep old ones */
|
| 1847 |
if (!p->ecmp || nh_is_vlink(nhs) || (nhs == en->nhs))
|
| 1848 |
return;
|
| 1849 |
|
| 1850 |
/* Merge old and new */
|
| 1851 |
int new_reuse = (par->nhs != nhs);
|
| 1852 |
en->nhs = nexthop_merge(en->nhs, nhs, en->nhs_reuse, new_reuse, p->ecmp, p->nhpool); |
| 1853 |
en->nhs_reuse = 1;
|
| 1854 |
return;
|
| 1855 |
} |
| 1856 |
|
| 1857 |
DBG(" Adding candidate: rt: %R, id: %R, type: %u\n",
|
| 1858 |
en->lsa.rt, en->lsa.id, en->lsa_type); |
| 1859 |
|
| 1860 |
if (en->color == CANDIDATE)
|
| 1861 |
{ /* We found a shorter path */
|
| 1862 |
rem_node(&en->cn); |
| 1863 |
} |
| 1864 |
en->nhs = nhs; |
| 1865 |
en->dist = dist; |
| 1866 |
en->color = CANDIDATE; |
| 1867 |
en->nhs_reuse = (par->nhs != nhs); |
| 1868 |
|
| 1869 |
prev = NULL;
|
| 1870 |
|
| 1871 |
if (EMPTY_LIST(*l))
|
| 1872 |
{
|
| 1873 |
add_head(l, &en->cn); |
| 1874 |
} |
| 1875 |
else
|
| 1876 |
{
|
| 1877 |
WALK_LIST(n, *l) |
| 1878 |
{
|
| 1879 |
act = SKIP_BACK(struct top_hash_entry, cn, n);
|
| 1880 |
if ((act->dist > dist) ||
|
| 1881 |
((act->dist == dist) && (act->lsa_type == LSA_T_RT))) |
| 1882 |
{
|
| 1883 |
if (prev == NULL) |
| 1884 |
add_head(l, &en->cn); |
| 1885 |
else
|
| 1886 |
insert_node(&en->cn, prev); |
| 1887 |
added = 1;
|
| 1888 |
break;
|
| 1889 |
} |
| 1890 |
prev = n; |
| 1891 |
} |
| 1892 |
|
| 1893 |
if (!added)
|
| 1894 |
{
|
| 1895 |
add_tail(l, &en->cn); |
| 1896 |
} |
| 1897 |
} |
| 1898 |
} |
| 1899 |
|
| 1900 |
static inline int |
| 1901 |
ort_changed(ort *nf, rta *nr) |
| 1902 |
{
|
| 1903 |
rta *or = nf->old_rta; |
| 1904 |
return !or ||
|
| 1905 |
(nf->n.metric1 != nf->old_metric1) || (nf->n.metric2 != nf->old_metric2) || |
| 1906 |
(nf->n.tag != nf->old_tag) || (nf->n.rid != nf->old_rid) || |
| 1907 |
(nr->source != or->source) || (nr->dest != or->dest) || |
| 1908 |
!nexthop_same(&(nr->nh), &(or->nh)); |
| 1909 |
} |
| 1910 |
|
| 1911 |
static void |
| 1912 |
rt_sync(struct ospf_proto *p)
|
| 1913 |
{
|
| 1914 |
struct top_hash_entry *en;
|
| 1915 |
struct fib_iterator fit;
|
| 1916 |
struct fib *fib = &p->rtf;
|
| 1917 |
struct ospf_area *oa;
|
| 1918 |
|
| 1919 |
/* This is used for forced reload of routes */
|
| 1920 |
int reload = (p->calcrt == 2); |
| 1921 |
|
| 1922 |
OSPF_TRACE(D_EVENTS, "Starting routing table synchronization");
|
| 1923 |
|
| 1924 |
DBG("Now syncing my rt table with nest's\n");
|
| 1925 |
FIB_ITERATE_INIT(&fit, fib); |
| 1926 |
again1:
|
| 1927 |
FIB_ITERATE_START(fib, &fit, ort, nf) |
| 1928 |
{
|
| 1929 |
/* Sanity check of next-hop addresses, failure should not happen */
|
| 1930 |
if (nf->n.type)
|
| 1931 |
{
|
| 1932 |
struct nexthop *nh;
|
| 1933 |
for (nh = nf->n.nhs; nh; nh = nh->next)
|
| 1934 |
if (ipa_nonzero(nh->gw))
|
| 1935 |
{
|
| 1936 |
neighbor *ng = neigh_find2(&p->p, &nh->gw, nh->iface, 0);
|
| 1937 |
if (!ng || (ng->scope == SCOPE_HOST))
|
| 1938 |
{ reset_ri(nf); break; }
|
| 1939 |
} |
| 1940 |
} |
| 1941 |
|
| 1942 |
/* Remove configured stubnets */
|
| 1943 |
if (!nf->n.nhs)
|
| 1944 |
reset_ri(nf); |
| 1945 |
|
| 1946 |
if (nf->n.type) /* Add the route */ |
| 1947 |
{
|
| 1948 |
rta a0 = {
|
| 1949 |
.src = p->p.main_source, |
| 1950 |
.source = nf->n.type, |
| 1951 |
.scope = SCOPE_UNIVERSE, |
| 1952 |
.dest = RTD_UNICAST, |
| 1953 |
.nh = *(nf->n.nhs), |
| 1954 |
}; |
| 1955 |
|
| 1956 |
if (reload || ort_changed(nf, &a0))
|
| 1957 |
{
|
| 1958 |
rta *a = rta_lookup(&a0); |
| 1959 |
rte *e = rte_get_temp(a); |
| 1960 |
|
| 1961 |
rta_free(nf->old_rta); |
| 1962 |
nf->old_rta = rta_clone(a); |
| 1963 |
e->u.ospf.metric1 = nf->old_metric1 = nf->n.metric1; |
| 1964 |
e->u.ospf.metric2 = nf->old_metric2 = nf->n.metric2; |
| 1965 |
e->u.ospf.tag = nf->old_tag = nf->n.tag; |
| 1966 |
e->u.ospf.router_id = nf->old_rid = nf->n.rid; |
| 1967 |
e->pflags = 0;
|
| 1968 |
|
| 1969 |
DBG("Mod rte type %d - %N via %I on iface %s, met %d\n",
|
| 1970 |
a0.source, nf->fn.addr, a0.gw, a0.iface ? a0.iface->name : "(none)", nf->n.metric1);
|
| 1971 |
rte_update(&p->p, nf->fn.addr, e); |
| 1972 |
} |
| 1973 |
} |
| 1974 |
else if (nf->old_rta) |
| 1975 |
{
|
| 1976 |
/* Remove the route */
|
| 1977 |
rta_free(nf->old_rta); |
| 1978 |
nf->old_rta = NULL;
|
| 1979 |
|
| 1980 |
rte_update(&p->p, nf->fn.addr, NULL);
|
| 1981 |
} |
| 1982 |
|
| 1983 |
/* Remove unused rt entry, some special entries are persistent */
|
| 1984 |
if (!nf->n.type && !nf->external_rte && !nf->area_net)
|
| 1985 |
{
|
| 1986 |
if (nf->lsa_id)
|
| 1987 |
idm_free(&p->idm, nf->lsa_id); |
| 1988 |
|
| 1989 |
FIB_ITERATE_PUT(&fit); |
| 1990 |
fib_delete(fib, nf); |
| 1991 |
goto again1;
|
| 1992 |
} |
| 1993 |
} |
| 1994 |
FIB_ITERATE_END; |
| 1995 |
|
| 1996 |
|
| 1997 |
WALK_LIST(oa, p->area_list) |
| 1998 |
{
|
| 1999 |
/* Cleanup ASBR hash tables */
|
| 2000 |
FIB_ITERATE_INIT(&fit, &oa->rtr); |
| 2001 |
again2:
|
| 2002 |
FIB_ITERATE_START(&oa->rtr, &fit, ort, nf) |
| 2003 |
{
|
| 2004 |
if (!nf->n.type)
|
| 2005 |
{
|
| 2006 |
FIB_ITERATE_PUT(&fit); |
| 2007 |
fib_delete(&oa->rtr, nf); |
| 2008 |
goto again2;
|
| 2009 |
} |
| 2010 |
} |
| 2011 |
FIB_ITERATE_END; |
| 2012 |
} |
| 2013 |
|
| 2014 |
/* Cleanup stale LSAs */
|
| 2015 |
WALK_SLIST(en, p->lsal) |
| 2016 |
if (en->mode == LSA_M_STALE)
|
| 2017 |
ospf_flush_lsa(p, en); |
| 2018 |
} |