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-rw-r--r--proto/ospf/rt.c115
1 files changed, 82 insertions, 33 deletions
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index f57925c3..b289d767 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -10,9 +10,7 @@
#include "ospf.h"
-static void add_cand(list * l, struct top_hash_entry *en,
- struct top_hash_entry *par, u32 dist,
- struct ospf_area *oa, int i);
+static void add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry *par, u32 dist, int i, uint lif, uint nif);
static void rt_sync(struct ospf_proto *p);
@@ -509,7 +507,7 @@ spfa_process_rt(struct ospf_proto *p, struct ospf_area *oa, struct top_hash_entr
break;
}
- add_cand(&oa->cand, tmp, act, act->dist + rtl.metric, oa, i);
+ add_cand(oa, tmp, act, act->dist + rtl.metric, i, rtl.lif, rtl.nif);
}
}
@@ -532,7 +530,7 @@ spfa_process_net(struct ospf_proto *p, struct ospf_area *oa, struct top_hash_ent
for (i = 0; i < cnt; i++)
{
tmp = ospf_hash_find_rt(p->gr, oa->areaid, ln->routers[i]);
- add_cand(&oa->cand, tmp, act, act->dist, oa, -1);
+ add_cand(oa, tmp, act, act->dist, -1, 0, 0);
}
}
@@ -651,7 +649,8 @@ ospf_rt_spfa(struct ospf_area *oa)
}
static int
-link_back(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry *par)
+link_back(struct ospf_area *oa, struct top_hash_entry *en,
+ struct top_hash_entry *par, uint lif, uint nif)
{
struct ospf_proto *p = oa->po;
struct ospf_lsa_rt_walk rtl;
@@ -689,6 +688,10 @@ link_back(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
tmp = ospf_hash_find_net(p->gr, oa->areaid, rtl.id, rtl.nif);
if (tmp == par)
{
+ /*
+ * Note that there may be multiple matching Rt-fields if router 'en'
+ * have multiple interfaces to net 'par'. Perhaps we should do ECMP.
+ */
if (ospf_is_v2(p))
en->lb = ipa_from_u32(rtl.data);
else
@@ -700,7 +703,13 @@ link_back(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
case LSART_VLNK:
case LSART_PTP:
- /* Not necessary the same link, see RFC 2328 [23] */
+ /*
+ * For OSPFv2, not necessary the same link, see RFC 2328 [23].
+ * For OSPFv3, we verify that by comparing nif and lif fields.
+ */
+ if (ospf_is_v3(p) && ((rtl.lif != nif) || (rtl.nif != lif)))
+ break;
+
tmp = ospf_hash_find_rt(p->gr, oa->areaid, rtl.id);
if (tmp == par)
return 1;
@@ -1679,13 +1688,27 @@ inherit_nexthops(struct nexthop *pn)
return pn && (ipa_nonzero(pn->gw) || !pn->iface);
}
+static inline ip_addr
+link_lsa_lladdr(struct ospf_proto *p, struct top_hash_entry *en)
+{
+ struct ospf_lsa_link *link_lsa = en->lsa_body;
+ ip6_addr ll = link_lsa->lladdr;
+
+ if (ip6_zero(ll))
+ return IPA_NONE;
+
+ return ospf_is_ip4(p) ? ipa_from_ip4(ospf3_6to4(ll)) : ipa_from_ip6(ll);
+}
+
static struct nexthop *
calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
- struct top_hash_entry *par, int pos)
+ struct top_hash_entry *par, int pos, uint lif, uint nif)
{
struct ospf_proto *p = oa->po;
struct nexthop *pn = par->nhs;
- struct ospf_iface *ifa;
+ struct top_hash_entry *link = NULL;
+ struct ospf_iface *ifa = NULL;
+ ip_addr nh = IPA_NONE;
u32 rid = en->lsa.rt;
/* 16.1.1. The next hop calculation */
@@ -1710,6 +1733,9 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
if (!ifa)
return NULL;
+ if (ospf_is_v3(p) && (ifa->iface_id != lif))
+ log(L_WARN "%s: Inconsistent interface ID %u/%u", p->p.name, ifa->iface_id, lif);
+
return new_nexthop(p, IPA_NONE, ifa->iface, ifa->ecmp_weight);
}
@@ -1720,14 +1746,44 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
if (!ifa)
return NULL;
+ if (ospf_is_v3(p) && (ifa->iface_id != lif))
+ log(L_WARN "%s: Inconsistent interface ID %u/%u", p->p.name, ifa->iface_id, lif);
+
if (ifa->type == OSPF_IT_VLINK)
return new_nexthop(p, IPA_NONE, NULL, 0);
- struct ospf_neighbor *m = find_neigh(ifa, rid);
- if (!m || (m->state != NEIGHBOR_FULL))
- return NULL;
+ /* FIXME: On physical PtP links we may skip next-hop altogether */
+
+ if (ospf_is_v2(p) || ospf_is_ip6(p))
+ {
+ /*
+ * In this case, next-hop is a source address from neighbor's packets.
+ * That is necessary for OSPFv2 and practical for OSPFv3 (as it works even
+ * if neighbor uses LinkLSASuppression), but does not work with OSPFv3-AF
+ * on IPv4 topology, where src is IPv6 but next-hop should be IPv4.
+ */
+ struct ospf_neighbor *m = find_neigh(ifa, rid);
+ if (!m || (m->state != NEIGHBOR_FULL))
+ return NULL;
+
+ nh = m->ip;
+ }
+ else
+ {
+ /*
+ * Next-hop is taken from lladdr field of Link-LSA, based on Neighbor
+ * Iface ID (nif) field in our Router-LSA, which is just nbr->iface_id.
+ */
+ link = ospf_hash_find(p->gr, ifa->iface_id, nif, rid, LSA_T_LINK);
+ if (!link)
+ return NULL;
+
+ nh = link_lsa_lladdr(p, link);
+ if (ipa_zero(nh))
+ return NULL;
+ }
- return new_nexthop(p, m->ip, ifa->iface, ifa->ecmp_weight);
+ return new_nexthop(p, nh, ifa->iface, ifa->ecmp_weight);
}
/* The third case - bcast or nbma neighbor */
@@ -1754,21 +1810,14 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
* Next-hop is taken from lladdr field of Link-LSA, en->lb_id
* is computed in link_back().
*/
- struct top_hash_entry *lhe;
- lhe = ospf_hash_find(p->gr, pn->iface->index, en->lb_id, rid, LSA_T_LINK);
-
- if (!lhe)
+ link = ospf_hash_find(p->gr, pn->iface->index, en->lb_id, rid, LSA_T_LINK);
+ if (!link)
return NULL;
- struct ospf_lsa_link *llsa = lhe->lsa_body;
-
- if (ip6_zero(llsa->lladdr))
+ nh = link_lsa_lladdr(p, link);
+ if (ipa_zero(nh))
return NULL;
- ip_addr nh = ospf_is_ip4(p) ?
- ipa_from_ip4(ospf3_6to4(llsa->lladdr)) :
- ipa_from_ip6(llsa->lladdr);
-
return new_nexthop(p, nh, pn->iface, pn->weight);
}
}
@@ -1782,8 +1831,8 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
/* Add LSA into list of candidates in Dijkstra's algorithm */
static void
-add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
- u32 dist, struct ospf_area *oa, int pos)
+add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry *par,
+ u32 dist, int pos, uint lif, uint nif)
{
struct ospf_proto *p = oa->po;
node *prev, *n;
@@ -1813,10 +1862,10 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
return;
/* We should check whether there is a reverse link from en to par, */
- if (!link_back(oa, en, par))
+ if (!link_back(oa, en, par, lif, nif))
return;
- struct nexthop *nhs = calc_next_hop(oa, en, par, pos);
+ struct nexthop *nhs = calc_next_hop(oa, en, par, pos, lif, nif);
if (!nhs)
{
log(L_WARN "%s: Cannot find next hop for LSA (Type: %04x, Id: %R, Rt: %R)",
@@ -1873,20 +1922,20 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
prev = NULL;
- if (EMPTY_LIST(*l))
+ if (EMPTY_LIST(oa->cand))
{
- add_head(l, &en->cn);
+ add_head(&oa->cand, &en->cn);
}
else
{
- WALK_LIST(n, *l)
+ WALK_LIST(n, oa->cand)
{
act = SKIP_BACK(struct top_hash_entry, cn, n);
if ((act->dist > dist) ||
((act->dist == dist) && (act->lsa_type == LSA_T_RT)))
{
if (prev == NULL)
- add_head(l, &en->cn);
+ add_head(&oa->cand, &en->cn);
else
insert_node(&en->cn, prev);
added = 1;
@@ -1897,7 +1946,7 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
if (!added)
{
- add_tail(l, &en->cn);
+ add_tail(&oa->cand, &en->cn);
}
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 18:08:20 +0000