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bird/proto/ospf/rt.c
Ondrej Zajicek 353729f513 Temporary OSPF commit - socket changes.
2010-02-11 10:23:35 +01:00

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/*
* BIRD -- OSPF
*
* (c) 2000--2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#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);
static int calc_next_hop(struct ospf_area *oa,
struct top_hash_entry *en,
struct top_hash_entry *par);
static void ospf_ext_spf(struct proto_ospf *po);
static void rt_sync(struct proto_ospf *po);
/* In ospf_area->rtr we store paths to routers, but we use RID (and not IP address)
as index, so we need to encapsulate RID to IP address */
#ifdef OSPFv2
#define ipa_from_rid(x) _MI(x)
#else /* OSPFv3 */
#define ipa_from_rid(x) _MI(0,0,0,x)
#endif
static void
fill_ri(orta * orta)
{
orta->type = RTS_DUMMY;
orta->options = 0;
orta->oa = NULL;
orta->metric1 = LSINFINITY;
orta->metric2 = LSINFINITY;
orta->nh = IPA_NONE;
orta->ifa = NULL;
orta->ar = NULL;
orta->tag = 0;
orta->rid = 0;
}
void
ospf_rt_initort(struct fib_node *fn)
{
ort *ri = (ort *) fn;
fill_ri(&ri->n);
memcpy(&ri->o, &ri->n, sizeof(orta));
ri->efn = NULL;
}
/* If new is better return 1 */
/*
* This is hard to understand:
* If rfc1583 is set to 1, it work likes normal route_better()
* But if it is set to 0, it prunes number of AS boundary
* routes before it starts the router decision
*/
static int
ri_better(struct proto_ospf *po, orta * new, ort *nefn, orta * old, ort *oefn, int rfc1583)
{
int newtype = new->type;
int oldtype = old->type;
if (old->type == RTS_DUMMY)
return 1;
if (old->metric1 == LSINFINITY)
return 1;
if (!rfc1583)
{
if ((new->type < RTS_OSPF_EXT1) && (new->oa->areaid == 0)) newtype = RTS_OSPF_IA;
if ((old->type < RTS_OSPF_EXT1) && (old->oa->areaid == 0)) oldtype = RTS_OSPF_IA;
}
if (newtype < oldtype)
return 1;
if (newtype > oldtype)
return 0;
/* Same type */
if (new->type == RTS_OSPF_EXT2)
{
if (new->metric2 < old->metric2) return 1;
if (new->metric2 > old->metric2) return 0;
}
if (((new->type == RTS_OSPF_EXT2) || (new->type == RTS_OSPF_EXT1)) && (!po->rfc1583))
{
newtype = nefn->n.type;
oldtype = oefn->n.type;
if (nefn->n.oa->areaid == 0) newtype = RTS_OSPF_IA;
if (oefn->n.oa->areaid == 0) oldtype = RTS_OSPF_IA;
if (newtype < oldtype) return 1;
if (newtype > oldtype) return 0;
}
if (new->metric1 < old->metric1)
return 1;
if (new->metric1 > old->metric1)
return 0;
if (new->oa->areaid > old->oa->areaid) return 1; /* Larger AREAID is preffered */
return 0; /* Old is shorter or same */
}
static void
ri_install(struct proto_ospf *po, ip_addr prefix, int pxlen, int dest,
orta * new, ort * ipath)
{
struct ospf_area *oa = new->oa;
ort *old;
if (dest == ORT_NET)
{
struct area_net *anet;
old = (ort *) fib_get(&po->rtf, &prefix, pxlen);
if (ri_better(po, new, ipath, &old->n, old->efn, 1))
{
memcpy(&old->n, new, sizeof(orta));
old->efn = ipath;
if ((new->type == RTS_OSPF) && (anet = (struct area_net *)fib_route(&oa->net_fib, prefix, pxlen)))
{
anet->active = 1;
if (new->metric1 > anet->metric) anet->metric = new->metric1;
}
}
}
else
{
old = (ort *) fib_get(&oa->rtr, &prefix, pxlen);
if (ri_better(po, new, ipath, &old->n, old->efn, 1))
{
memcpy(&old->n, new, sizeof(orta));
old->efn = ipath;
}
}
}
static void
add_network(struct ospf_area *oa, ip_addr px, int pxlen, int metric, struct top_hash_entry *en)
{
orta nf;
nf.type = RTS_OSPF;
nf.options = 0;
nf.metric1 = metric;
nf.metric2 = LSINFINITY;
nf.tag = 0;
nf.oa = oa;
nf.ar = en;
nf.nh = en->nh;
nf.ifa = en->nhi;
nf.rid = en->lsa.rt;
/* FIXME check nf.ifa on stubs */
ri_install(oa->po, px, pxlen, ORT_NET, &nf, NULL);
}
#ifdef OSPFv3
static void
process_prefixes(struct ospf_area *oa)
{
struct proto_ospf *po = oa->po;
struct proto *p = &po->proto;
struct top_hash_entry *en, *src;
struct ospf_lsa_prefix *px;
ip_addr pxa;
int pxlen;
u8 pxopts;
u16 metric;
u32 *buf;
int i;
WALK_SLIST(en, po->lsal)
{
if (en->lsa.type != LSA_T_PREFIX)
continue;
if (en->domain != oa->areaid)
continue;
if (en->lsa.age == LSA_MAXAGE)
continue;
px = en->lsa_body;
/* For router prefix-LSA, we would like to find the first router-LSA */
if (px->ref_type == LSA_T_RT)
src = ospf_hash_find_rt(po->gr, oa->areaid, px->ref_rt);
else
src = ospf_hash_find(po->gr, oa->areaid, px->ref_id, px->ref_rt, px->ref_type);
if (!src)
continue;
if (src->lsa.age == LSA_MAXAGE)
continue;
if ((src->lsa.type != LSA_T_RT) && (src->lsa.type != LSA_T_NET))
continue;
buf = px->rest;
for (i = 0; i < px->pxcount; i++)
{
buf = lsa_get_ipv6_prefix(buf, &pxa, &pxlen, &pxopts, &metric);
if (pxopts & OPT_PX_NU)
continue;
add_network(oa, pxa, pxlen, src->dist + metric, src);
}
}
}
#endif
static void
ospf_rt_spfa_rtlinks(struct ospf_area *oa, struct top_hash_entry *act, struct top_hash_entry *en)
{
struct proto *p = &oa->po->proto;
struct proto_ospf *po = oa->po;
orta nf;
u32 i;
struct ospf_lsa_rt *rt = en->lsa_body;
struct ospf_lsa_rt_link *rr = (struct ospf_lsa_rt_link *) (rt + 1);
for (i = 0; i < lsa_rt_count(&en->lsa); i++)
{
struct ospf_lsa_rt_link *rtl = rr + i;
struct top_hash_entry *tmp = NULL;
DBG(" Working on link: %R (type: %u) ", rtl->id, rtl->type);
switch (rtl->type)
{
#ifdef OSPFv2
case LSART_STUB:
/*
* This violates rfc2328! But it is mostly harmless.
*/
DBG("\n");
nf.type = RTS_OSPF;
nf.options = 0;
nf.metric1 = act->dist + rtl->metric;
nf.metric2 = LSINFINITY;
nf.tag = 0;
nf.oa = oa;
nf.ar = act;
nf.nh = act->nh;
nf.ifa = act->nhi;
nf.rid = act->lsa.rt;
if (act == oa->rt)
{
struct ospf_iface *iff;
WALK_LIST(iff, po->iface_list) /* Try to find corresponding interface */
{
// FIXME this is broken
if (iff->iface && (iff->type != OSPF_IT_VLINK) &&
(rtl->id == (ipa_to_u32(ipa_mkmask(iff->addr->pxlen))
& ipa_to_u32(iff->addr->prefix)))) /* No VLINK and IP must match */
{
nf.ifa = iff;
break;
}
}
}
if (!nf.ifa)
continue;
ri_install(po, ipa_from_u32(rtl->id),
ipa_mklen(ipa_from_u32(rtl->data)), ORT_NET, &nf, NULL);
break;
#endif
case LSART_NET:
#ifdef OSPFv2
/* In OSPFv2, rtl->id is IP addres of DR, Router ID is not known */
tmp = ospf_hash_find_net(po->gr, oa->areaid, rtl->id);
#else /* OSPFv3 */
tmp = ospf_hash_find(po->gr, oa->areaid, rtl->nif, rtl->id, LSA_T_NET);
#endif
if (tmp == NULL)
DBG("Not found!\n");
else
DBG("Found. :-)\n");
break;
case LSART_VLNK:
case LSART_PTP:
tmp = ospf_hash_find_rt(po->gr, oa->areaid, rtl->id);
DBG("PTP found.\n");
break;
default:
log("Unknown link type in router lsa. (rid = %R)", act->lsa.id);
break;
}
if (tmp)
DBG("Going to add cand, Mydist: %u, Req: %u\n",
tmp->dist, act->dist + rtl->metric);
add_cand(&oa->cand, tmp, act, act->dist + rtl->metric, oa);
}
}
/* 16.1 calculating shortest paths for an area */
static void
ospf_rt_spfa(struct ospf_area *oa)
{
struct proto *p = &oa->po->proto;
struct proto_ospf *po = oa->po;
struct ospf_lsa_rt *rt;
struct ospf_lsa_net *ln;
struct ospf_iface *iface;
struct top_hash_entry *act, *tmp;
u32 i, *rts;
orta nf;
node *n;
if (oa->rt == NULL)
return;
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for area %R", oa->areaid);
if (oa->rt->dist != LSINFINITY)
bug("Aging was not processed.");
/* 16.1. (1) */
init_list(&oa->cand); /* Empty list of candidates */
oa->trcap = 0;
DBG("LSA db prepared, adding me into candidate list.\n");
oa->rt->dist = 0;
oa->rt->color = CANDIDATE;
add_head(&oa->cand, &oa->rt->cn);
DBG("RT LSA: rt: %R, id: %R, type: %u\n",
oa->rt->lsa.rt, oa->rt->lsa.id, oa->rt->lsa.type);
while (!EMPTY_LIST(oa->cand))
{
n = HEAD(oa->cand);
act = SKIP_BACK(struct top_hash_entry, cn, n);
rem_node(n);
DBG("Working on LSA: rt: %R, id: %R, type: %u\n",
act->lsa.rt, act->lsa.id, act->lsa.type);
act->color = INSPF;
switch (act->lsa.type)
{
case LSA_T_RT:
rt = (struct ospf_lsa_rt *) act->lsa_body;
if (rt->options & OPT_RT_V)
oa->trcap = 1;
/* In OSPFv2, just ASBRs and ABRs are needed to add to oa->rtr table */
// ((rt->options & OPT_RT_V) || (rt->options & OPT_RT_E))
nf.type = RTS_OSPF;
nf.options = rt->options;
nf.metric1 = act->dist;
nf.metric2 = LSINFINITY;
nf.tag = 0;
nf.oa = oa;
nf.ar = act;
nf.nh = act->nh;
nf.ifa = act->nhi;
nf.rid = act->lsa.rt;
ri_install(po, ipa_from_rid(act->lsa.rt), MAX_PREFIX_LENGTH, ORT_ROUTER, &nf, NULL);
#ifdef OSPFv2
ospf_rt_spfa_rtlinks(oa, act, act);
#else /* OSPFv3 */
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);
#endif
break;
case LSA_T_NET:
ln = act->lsa_body;
#ifdef OSPFv2
add_network(oa, ipa_and(ipa_from_u32(act->lsa.id), ln->netmask),
ipa_mklen(ln->netmask), act->dist, act);
#endif
rts = (u32 *) (ln + 1);
for (i = 0; i < lsa_net_count(&act->lsa); i++)
{
DBG(" Working on router %R ", rts[i]);
tmp = ospf_hash_find_rt(po->gr, oa->areaid, rts[i]);
if (tmp != NULL)
DBG("Found :-)\n");
else
DBG("Not found!\n");
add_cand(&oa->cand, tmp, act, act->dist, oa);
}
break;
}
}
#ifdef OSPFv3
process_prefixes(oa);
#endif
/* Find new/lost VLINK peers */
WALK_LIST(iface, po->iface_list)
{
if ((iface->type == OSPF_IT_VLINK) && (iface->voa == oa))
{
if ((tmp = ospf_hash_find_rt(po->gr, oa->areaid, iface->vid)) &&
(!ipa_equal(tmp->lb, IPA_NONE)))
{
if ((iface->state != OSPF_IS_PTP) || (iface->iface != tmp->nhi->iface) || (!ipa_equal(iface->vip, tmp->lb)))
{
OSPF_TRACE(D_EVENTS, "Vlink peer %R found", tmp->lsa.id);
ospf_iface_sm(iface, ISM_DOWN);
iface->iface = tmp->nhi->iface;
iface->addr = iface->iface->addr;
iface->vip = tmp->lb;
ospf_iface_sm(iface, ISM_UP);
}
}
else
{
if (iface->state > OSPF_IS_DOWN)
{
OSPF_TRACE(D_EVENTS, "Vlink peer %R lost", iface->vid);
ospf_iface_sm(iface, ISM_DOWN);
}
}
}
}
}
static int
link_back(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry *par)
{
u32 i, *rts;
struct ospf_lsa_net *ln;
struct ospf_lsa_rt *rt;
struct ospf_lsa_rt_link *rtl, *rr;
struct top_hash_entry *tmp;
struct proto_ospf *po = oa->po;
if (!en || !par) return 0;
// FIXME lb should be properly set for vlinks */
en->lb = IPA_NONE;
switch (en->lsa.type)
{
case LSA_T_RT:
rt = (struct ospf_lsa_rt *) en->lsa_body;
rr = (struct ospf_lsa_rt_link *) (rt + 1);
for (i = 0; i < lsa_rt_count(&en->lsa); i++)
{
rtl = (rr + i);
switch (rtl->type)
{
case LSART_STUB:
break;
case LSART_NET:
#ifdef OSPFv2
/* In OSPFv2, rtl->id is IP addres of DR, Router ID is not known */
tmp = ospf_hash_find_net(po->gr, oa->areaid, rtl->id);
#else /* OSPFv3 */
tmp = ospf_hash_find(po->gr, oa->areaid, rtl->nif, rtl->id, LSA_T_NET);
#endif
if (tmp == par)
{
#ifdef OSPFv2
en->lb = ipa_from_u32(rtl->data);
#endif
return 1;
}
break;
case LSART_VLNK:
case LSART_PTP:
tmp = ospf_hash_find_rt(po->gr, oa->areaid, rtl->id);
if (tmp == par)
return 1;
break;
default:
log(L_WARN "Unknown link type in router lsa. (rid = %R)", en->lsa.rt);
break;
}
}
break;
case LSA_T_NET:
ln = en->lsa_body;
rts = (u32 *) (ln + 1);
for (i = 0; i < lsa_net_count(&en->lsa); i++)
{
tmp = ospf_hash_find_rt(po->gr, oa->areaid, rts[i]);
if (tmp == par)
return 1;
}
break;
default:
bug("Unknown lsa type %x.", en->lsa.type);
}
return 0;
}
/* 16.3 examining summary-LSAs in transit areas */
static void
ospf_rt_sum_tr(struct ospf_area *oa)
{
struct proto *p = &oa->po->proto;
struct proto_ospf *po = oa->po;
struct ospf_area *bb = po->backbone;
ip_addr ip, abrip;
struct top_hash_entry *en;
u32 dst_rid, metric, options;
int pxlen = -1, type = -1;
ort *re = NULL, *abr;
orta nf;
if (!bb) return;
WALK_SLIST(en, po->lsal)
{
if ((en->lsa.type != LSA_T_SUM_RT) && (en->lsa.type != LSA_T_SUM_NET))
continue;
if (en->domain != oa->areaid)
continue;
/* 16.3 (1a) */
if (en->lsa.age == LSA_MAXAGE)
continue;
// if (en->dist == LSINFINITY)
// continue;
/* 16.3 (2) */
if (en->lsa.rt == po->router_id)
continue;
if (en->lsa.type == LSA_T_SUM_NET)
{
#ifdef OSPFv2
struct ospf_lsa_sum *ls = en->lsa_body;
pxlen = ipa_mklen(ls->netmask);
ip = ipa_and(ipa_from_u32(en->lsa.id), ls->netmask);
#else /* OSPFv3 */
u8 pxopts;
u16 rest;
struct ospf_lsa_sum_net *ls = en->lsa_body;
lsa_get_ipv6_prefix(ls->prefix, &ip, &pxlen, &pxopts, &rest);
if (pxopts & OPT_PX_NU)
continue;
#endif
metric = ls->metric & METRIC_MASK;
options = 0;
type = ORT_NET;
re = fib_find(&po->rtf, &ip, pxlen);
}
else if (en->lsa.type == LSA_T_SUM_RT)
{
#ifdef OSPFv2
struct ospf_lsa_sum *ls = en->lsa_body;
dst_rid = en->lsa.id;
options = 0;
#else /* OSPFv3 */
struct ospf_lsa_sum_rt *ls = en->lsa_body;
dst_rid = ls->drid;
options = ls->options & OPTIONS_MASK;
#endif
ip = ipa_from_rid(dst_rid);
pxlen = MAX_PREFIX_LENGTH;
metric = ls->metric & METRIC_MASK;
options |= ORTA_ASBR;
type = ORT_ROUTER;
re = fib_find(&bb->rtr, &ip, pxlen);
}
/* 16.3 (1b) */
if (metric == LSINFINITY)
continue;
/* 16.3 (3) */
if (!re || !re->n.type) continue;
if (re->n.oa->areaid != 0) continue;
if ((re->n.type != RTS_OSPF) && (re->n.type != RTS_OSPF_IA)) continue;
/* 16.3. (4) */
abrip = ipa_from_rid(en->lsa.rt);
abr = fib_find(&oa->rtr, &abrip, MAX_PREFIX_LENGTH);
if (!abr || !abr->n.type) continue;
nf.type = re->n.type;
nf.options = options;
nf.metric1 = abr->n.metric1 + metric;
nf.metric2 = LSINFINITY;
nf.tag = 0;
nf.oa = oa;
nf.ar = abr->n.ar;
nf.nh = abr->n.nh;
nf.ifa = abr->n.ifa;
nf.rid = en->lsa.rt; /* ABR ID */
ri_install(po, ip, pxlen, type, &nf, NULL);
}
}
/* 16.2 calculating inter-area routes */
static void
ospf_rt_sum(struct ospf_area *oa)
{
struct proto_ospf *po = oa->po;
struct proto *p = &po->proto;
struct top_hash_entry *en;
ip_addr ip, abrip; /* abrIP is actually ID */
u32 dst_rid, metric, options;
struct area_net *anet;
orta nf;
ort *abr;
int pxlen = -1, type = -1;
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for inter-area (area %R)", oa->areaid);
WALK_SLIST(en, po->lsal)
{
if ((en->lsa.type != LSA_T_SUM_RT) && (en->lsa.type != LSA_T_SUM_NET))
continue;
if (en->domain != oa->areaid)
continue;
/* Page 169 (1) */
if (en->lsa.age == LSA_MAXAGE)
continue;
/* Page 169 (2) */
if (en->lsa.rt == po->router_id)
continue;
if (en->lsa.type == LSA_T_SUM_NET)
{
struct ospf_area *oaa;
int skip = 0;
#ifdef OSPFv2
struct ospf_lsa_sum *ls = en->lsa_body;
pxlen = ipa_mklen(ls->netmask);
ip = ipa_and(ipa_from_u32(en->lsa.id), ls->netmask);
#else /* OSPFv3 */
u8 pxopts;
u16 rest;
struct ospf_lsa_sum_net *ls = en->lsa_body;
lsa_get_ipv6_prefix(ls->prefix, &ip, &pxlen, &pxopts, &rest);
if (pxopts & OPT_PX_NU)
continue;
#endif
metric = ls->metric & METRIC_MASK;
options = 0;
type = ORT_NET;
/* Page 169 (3) */
WALK_LIST(oaa, po->area_list)
{
if ((anet = fib_find(&oaa->net_fib, &ip, pxlen)) && anet->active)
{
skip = 1;
break;
}
}
if (skip) continue;
}
else
{
#ifdef OSPFv2
struct ospf_lsa_sum *ls = en->lsa_body;
dst_rid = en->lsa.id;
options = 0;
#else /* OSPFv3 */
struct ospf_lsa_sum_rt *ls = en->lsa_body;
dst_rid = ls->drid;
options = ls->options & OPTIONS_MASK;
#endif
ip = ipa_from_rid(dst_rid);
pxlen = MAX_PREFIX_LENGTH;
metric = ls->metric & METRIC_MASK;
options |= ORTA_ASBR;
type = ORT_ROUTER;
}
/* Page 169 (1) */
if (metric == LSINFINITY)
continue;
/* Page 169 (4) */
abrip = ipa_from_rid(en->lsa.rt);
abr = (ort *) fib_find(&oa->rtr, &abrip, MAX_PREFIX_LENGTH);
if (!abr || !abr->n.type) continue;
if (abr->n.metric1 == LSINFINITY) continue;
if (!(abr->n.options & ORTA_ABR)) continue;
nf.type = RTS_OSPF_IA;
nf.options = options;
nf.metric1 = abr->n.metric1 + metric;
nf.metric2 = LSINFINITY;
nf.tag = 0;
nf.oa = oa;
nf.ar = abr->n.ar;
nf.nh = abr->n.nh;
nf.ifa = abr->n.ifa;
nf.rid = en->lsa.rt; /* ABR ID */
ri_install(po, ip, pxlen, type, &nf, NULL);
}
}
/**
* ospf_rt_spf - calculate internal routes
* @po: OSPF protocol
*
* Calculation of internal paths in an area is described in 16.1 of RFC 2328.
* It's based on Dijkstra's shortest path tree algorithms.
* This function is invoked from ospf_disp().
*/
void
ospf_rt_spf(struct proto_ospf *po)
{
struct proto *p = &po->proto;
struct ospf_area *oa;
ort *ri;
struct area_net *anet;
if (po->areano == 0) return;
po->cleanup = 1;
OSPF_TRACE(D_EVENTS, "Starting routing table calculation");
/* 16. (1) - Invalidate old routing table */
FIB_WALK(&po->rtf, nftmp)
{
ri = (ort *) nftmp;
memcpy(&ri->o, &ri->n, sizeof(orta)); /* Backup old data */
fill_ri(&ri->n);
}
FIB_WALK_END;
WALK_LIST(oa, po->area_list)
{
FIB_WALK(&oa->rtr, nftmp)
{
ri = (ort *) nftmp;
memcpy(&ri->o, &ri->n, sizeof(orta)); /* Backup old data */
fill_ri(&ri->n);
}
FIB_WALK_END;
FIB_WALK(&oa->net_fib, nftmp)
{
anet = (struct area_net *) nftmp;
anet->active = 0;
anet->metric = 1;
}
FIB_WALK_END;
/* 16. (2) */
ospf_rt_spfa(oa);
}
/* 16. (3) */
if ((po->areano == 1) || (!po->backbone))
{
ospf_rt_sum(HEAD(po->area_list));
}
else
{
ospf_rt_sum(po->backbone);
}
/* 16. (4) */
WALK_LIST(oa, po->area_list)
{
if (oa->trcap && (oa->areaid != 0))
{
ospf_rt_sum_tr(oa);
break;
}
}
/* 16. (5) */
ospf_ext_spf(po);
rt_sync(po);
po->calcrt = 0;
}
/**
* ospf_ext_spf - calculate external paths
* @po: protocol
*
* After routing table for any area is calculated, calculation of external
* path is invoked. This process is described in 16.4 of RFC 2328.
* Inter- and Intra-area paths are always prefered over externals.
*/
static void
ospf_ext_spf(struct proto_ospf *po)
{
ort *nf1, *nf2, *nfh;
orta nfa;
struct top_hash_entry *en;
struct proto *p = &po->proto;
struct ospf_lsa_ext *le;
int pxlen, ebit, rt_fwaddr_valid;
ip_addr ip, nh, rtid, rt_fwaddr;
struct ospf_iface *nhi = NULL;
u32 br_metric, rt_metric, rt_tag;
neighbor *nn;
struct ospf_area *atmp;
OSPF_TRACE(D_EVENTS, "Starting routing table calculation for ext routes");
WALK_SLIST(en, po->lsal)
{
/* 16.4. (1) */
if (en->lsa.type != LSA_T_EXT)
continue;
if (en->lsa.age == LSA_MAXAGE)
continue;
/* 16.4. (2) */
if (en->lsa.rt == po->router_id)
continue;
DBG("%s: Working on LSA. ID: %R, RT: %R, Type: %u\n",
p->name, en->lsa.id, en->lsa.rt, en->lsa.type);
le = en->lsa_body;
rt_metric = le->metric & METRIC_MASK;
ebit = le->metric & LSA_EXT_EBIT;
if (rt_metric == LSINFINITY)
continue;
#ifdef OSPFv2
ip = ipa_and(ipa_from_u32(en->lsa.id), le->netmask);
pxlen = ipa_mklen(le->netmask);
rt_fwaddr = le->fwaddr;
rt_fwaddr_valid = !ipa_equal(rt_fwaddr, IPA_NONE);
rt_tag = le->tag;
#else /* OSPFv3 */
u8 pxopts;
u16 rest;
u32 *buf = le->rest;
buf = lsa_get_ipv6_prefix(buf, &ip, &pxlen, &pxopts, &rest);
if (pxopts & OPT_PX_NU)
continue;
rt_fwaddr_valid = le->metric & LSA_EXT_FBIT;
if (rt_fwaddr_valid)
buf = lsa_get_ipv6_addr(buf, &rt_fwaddr);
else
rt_fwaddr = IPA_NONE;
if (le->metric & LSA_EXT_TBIT)
rt_tag = *buf++;
else
rt_tag = 0;
#endif
if (pxlen < 0)
{
log(L_WARN "%s: Invalid mask in LSA (Type: %04x, Id: %R, Rt: %R)",
p->name, en->lsa.type, en->lsa.id, en->lsa.rt);
continue;
}
nhi = NULL;
nh = IPA_NONE;
/* 16.4. (3) */
rtid = ipa_from_rid(en->lsa.rt);
nf1 = NULL;
WALK_LIST(atmp, po->area_list)
{
nfh = fib_find(&atmp->rtr, &rtid, MAX_PREFIX_LENGTH);
if (!nfh || !nfh->n.type) continue;
if (nf1 == NULL) nf1 = nfh;
else if (ri_better(po, &nfh->n, NULL, &nf1->n, NULL, po->rfc1583)) nf1 = nfh;
}
if (!nf1)
continue; /* No AS boundary router found */
if (nf1->n.metric1 == LSINFINITY)
continue; /* distance is INF */
if (!(nf1->n.options & ORTA_ASBR))
continue; /* It is not ASBR */
if (!rt_fwaddr_valid)
{
nh = nf1->n.nh;
nhi = nf1->n.ifa;
nfh = nf1;
br_metric = nf1->n.metric1;
}
else
{
nf2 = fib_route(&po->rtf, rt_fwaddr, MAX_PREFIX_LENGTH);
if (!nf2)
{
DBG("Cannot find network route (GW=%I)\n", rt_fwaddr);
continue;
}
if ((nn = neigh_find(p, &rt_fwaddr, 0)) != NULL)
{
nh = rt_fwaddr;
nhi = ospf_iface_find(po, nn->iface);
}
else
{
nh = nf2->n.nh;
nhi = nf2->n.ifa;
}
br_metric = nf2->n.metric1;
if (br_metric == LSINFINITY)
continue; /* distance is INF */
}
if (ebit)
{
nfa.type = RTS_OSPF_EXT2;
nfa.metric1 = br_metric;
nfa.metric2 = rt_metric;
}
else
{
nfa.type = RTS_OSPF_EXT1;
nfa.metric1 = br_metric + rt_metric;
nfa.metric2 = LSINFINITY;
}
nfa.options = 0;
nfa.tag = rt_tag;
nfa.oa = (po->backbone == NULL) ? HEAD(po->area_list) : po->backbone;
nfa.ar = nf1->n.ar;
nfa.nh = nh;
nfa.ifa = nhi;
nfa.rid = en->lsa.rt;
ri_install(po, ip, pxlen, ORT_NET, &nfa, nfh);
}
}
/* 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)
{
node *prev, *n;
int added = 0;
struct top_hash_entry *act;
/* 16.1. (2b) */
if (en == NULL)
return;
if (en->lsa.age == LSA_MAXAGE)
return;
#ifdef OSPFv3
if (en->lsa.type == LSA_T_RT)
{
struct ospf_lsa_rt *rt = en->lsa_body;
if (!(rt->options & OPT_V6) || !(rt->options & OPT_R))
return;
}
#endif
/* 16.1. (2c) */
if (en->color == INSPF)
return;
/* 16.1. (2d) */
if (dist >= en->dist)
return;
/*
* FIXME The line above (=) is not a bug, but we don't support multiple
* next hops. I'll start as soon as nest will
*/
/* We should check whether there is a reverse link from en to par, */
if (!link_back(oa, en, par))
return;
if (!calc_next_hop(oa, en, par))
{
log(L_WARN "Cannot find next hop for LSA (Type: %04x, Id: %R, Rt: %R)",
en->lsa.type, en->lsa.id, en->lsa.rt);
return;
}
DBG(" Adding candidate: rt: %R, id: %R, type: %u\n",
en->lsa.rt, en->lsa.id, en->lsa.type);
if (en->color == CANDIDATE)
{ /* We found a shorter path */
rem_node(&en->cn);
}
en->dist = dist;
en->color = CANDIDATE;
prev = NULL;
if (EMPTY_LIST(*l))
{
add_head(l, &en->cn);
}
else
{
WALK_LIST(n, *l)
{
act = SKIP_BACK(struct top_hash_entry, cn, n);
if ((act->dist > dist) ||
((act->dist == dist) && (act->lsa.type == LSA_T_NET)))
/* FIXME - shouldn't be here LSA_T_RT ??? */
{
if (prev == NULL)
add_head(l, &en->cn);
else
insert_node(&en->cn, prev);
added = 1;
break;
}
prev = n;
}
if (!added)
{
add_tail(l, &en->cn);
}
}
}
static inline int
match_dr(struct ospf_iface *ifa, struct top_hash_entry *en)
{
#ifdef OSPFv2
return (ifa->drid == en->lsa.rt) && (ipa_to_u32(ifa->drip) == en->lsa.id);
#else /* OSPFv3 */
return (ifa->drid == en->lsa.rt) && (ifa->dr_iface_id == en->lsa.id);
#endif
}
static int
calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
struct top_hash_entry *par)
{
struct ospf_neighbor *neigh;
struct proto *p = &oa->po->proto;
struct proto_ospf *po = oa->po;
struct ospf_iface *ifa;
/* 16.1.1. The next hop calculation */
DBG(" Next hop called.\n");
if (ipa_equal(par->nh, IPA_NONE))
{
DBG(" Next hop calculating for id: %R rt: %R type: %u\n",
en->lsa.id, en->lsa.rt, en->lsa.type);
/*
* There are three cases:
* 1) en is a local network (and par is root)
* 2) en is a ptp or ptmp neighbor (and par is root)
* 3) en is a bcast or nbma neighbor (and par is local network)
*/
/* The first case - local network */
if ((en->lsa.type == LSA_T_NET) && (par == oa->rt))
{
WALK_LIST(ifa, po->iface_list)
if (match_dr(ifa, en))
{
en->nh = IPA_NONE;
en->nhi = ifa;
return 1;
}
return 0;
}
/*
* Remaining cases - local neighbours.
* There are two problems with this code:
* 1) we use IP address from HELLO packet
* and not the one from LSA (router or link).
* This may break NBMA networks
* 2) we use find_neigh_noifa() and does not
* take into account associated iface.
* This breaks neighbors connected by more links.
*/
if ((en->lsa.type == LSA_T_RT) &&
((par == oa->rt) || (par->lsa.type == LSA_T_NET)))
{
if ((neigh = find_neigh_noifa(po, en->lsa.rt)) != NULL)
{
en->nh = neigh->ip;
en->nhi = neigh->ifa;
return 1;
}
return 0;
}
/* Probably bug or some race condition, we log it */
log(L_ERR "Unexpected case in next hop calculation");
return 0;
}
en->nh = par->nh;
en->nhi = par->nhi;
return 1;
}
static void
rt_sync(struct proto_ospf *po)
{
struct proto *p = &po->proto;
struct fib_iterator fit;
struct fib *fib = &po->rtf;
ort *nf;
struct ospf_area *oa, *oaa;
struct area_net *anet;
int flush;
/* This is used for forced reload of routes */
int reload = (po->calcrt == 2);
OSPF_TRACE(D_EVENTS, "Starting routing table synchronisation");
DBG("Now syncing my rt table with nest's\n");
FIB_ITERATE_INIT(&fit, fib);
again1:
FIB_ITERATE_START(fib, &fit, nftmp)
{
nf = (ort *) nftmp;
check_sum_lsa(po, nf, ORT_NET);
if (reload || memcmp(&nf->n, &nf->o, sizeof(orta)))
{ /* Some difference */
net *ne;
rta a0;
rte *e;
bzero(&a0, sizeof(a0));
a0.proto = p;
a0.source = nf->n.type;
a0.scope = SCOPE_UNIVERSE;
a0.cast = RTC_UNICAST;
a0.dest = RTD_ROUTER;
a0.flags = 0;
a0.aflags = 0;
a0.iface = NULL;
if (nf->n.ifa) a0.iface = nf->n.ifa->iface;
a0.gw = nf->n.nh;
if (ipa_nonzero(nf->n.nh) && (!neigh_find2(p, &nf->n.nh, nf->n.ifa->iface, 0)))
{
int found = 0;
struct ospf_iface *ifa;
struct top_hash_entry *en;
OSPF_TRACE(D_EVENTS, "Trying to find correct next hop %I/%d via %I", nf->fn.prefix, nf->fn.pxlen, nf->n.nh);
WALK_LIST(ifa, po->iface_list)
{
if ((ifa->type == OSPF_IT_VLINK) && ipa_equal(ifa->vip, nf->n.nh))
{
if ((en = ospf_hash_find_rt(po->gr, ifa->voa->areaid, ifa->vid))
&& (!ipa_equal(en->nh, IPA_NONE)))
{
a0.gw = en->nh;
found = 1;
}
break;
}
}
if (!found) nf->n.metric1 = LSINFINITY; /* Delete it */
}
if (ipa_equal(nf->n.nh, IPA_NONE)) a0.dest = RTD_DEVICE;
if (!a0.iface) /* Still no match? Can this really happen? */
nf->n.metric1 = LSINFINITY;
ne = net_get(p->table, nf->fn.prefix, nf->fn.pxlen);
if (nf->n.metric1 < LSINFINITY)
{
e = rte_get_temp(&a0);
e->u.ospf.metric1 = nf->n.metric1;
e->u.ospf.metric2 = nf->n.metric2;
e->u.ospf.tag = nf->n.tag;
e->u.ospf.router_id = nf->n.rid;
e->pflags = 0;
e->net = ne;
e->pref = p->preference;
DBG("Mod rte type %d - %I/%d via %I on iface %s, met %d\n",
a0.source, nf->fn.prefix, nf->fn.pxlen, a0.gw, a0.iface ? a0.iface->name : "(none)", nf->n.metric1);
rte_update(p->table, ne, p, p, e);
}
else
{
rte_update(p->table, ne, p, p, NULL);
FIB_ITERATE_PUT(&fit, nftmp);
fib_delete(fib, nftmp);
goto again1;
}
}
}
FIB_ITERATE_END(nftmp);
WALK_LIST(oa, po->area_list)
{
FIB_ITERATE_INIT(&fit, &oa->rtr);
again2:
FIB_ITERATE_START(&oa->rtr, &fit, nftmp)
{
nf = (ort *) nftmp;
if (memcmp(&nf->n, &nf->o, sizeof(orta)))
{ /* Some difference */
check_sum_lsa(po, nf, ORT_ROUTER);
if (nf->n.metric1 >= LSINFINITY)
{
FIB_ITERATE_PUT(&fit, nftmp);
fib_delete(&oa->rtr, nftmp);
goto again2;
}
}
}
FIB_ITERATE_END(nftmp);
/* Check condensed summary LSAs */
FIB_WALK(&oa->net_fib, nftmp)
{
flush = 1;
anet = (struct area_net *) nftmp;
if ((!anet->hidden) && anet->active)
flush = 0;
WALK_LIST(oaa, po->area_list)
{
int fl = flush;
if (oaa == oa) continue;
if ((oa == po->backbone) && oaa->trcap) fl = 1;
if (oaa->stub) fl = 1;
if (fl) flush_sum_lsa(oaa, &anet->fn, ORT_NET);
else originate_sum_lsa(oaa, &anet->fn, ORT_NET, anet->metric, 0);
}
}
FIB_WALK_END;
/* Check default summary LSA for stub areas
* just for router connected to backbone */
if (po->backbone)
{
struct fib_node fnn;
fnn.prefix = IPA_NONE;
fnn.pxlen = 0;
if (oa->stub) originate_sum_lsa(oa, &fnn, ORT_NET, oa->stub, 0);
else flush_sum_lsa(oa, &fnn, ORT_NET);
}
}
}
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