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bird/proto/ospf/topology.c
Ondrej Filip 035f6acbfe Patch from Andreas Steinmetz <ast@domdv.de>
2004-06-01 13:12:10 +00:00

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/*
* BIRD -- OSPF Topological Database
*
* (c) 1999 Martin Mares <mj@ucw.cz>
* (c) 1999 - 2000 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "nest/bird.h"
#include "lib/string.h"
#include "ospf.h"
#define HASH_DEF_ORDER 6
#define HASH_HI_MARK *4
#define HASH_HI_STEP 2
#define HASH_HI_MAX 16
#define HASH_LO_MARK /5
#define HASH_LO_STEP 2
#define HASH_LO_MIN 8
void *
originate_rt_lsa_body(struct ospf_area *oa, u16 *length, struct proto_ospf *p)
{
struct ospf_iface *ifa;
int j=0,k=0,v=0;
u16 i=0;
struct ospf_lsa_rt *rt;
struct ospf_lsa_rt_link *ln;
struct ospf_neighbor *neigh;
struct top_hash_entry *old;
struct proto_ospf *po=(struct proto_ospf *)p;
DBG("%s: Originating RT_lsa body for area \"%I\".\n", po->proto.name,
oa->areaid);
WALK_LIST (ifa, p->iface_list)
{
if((ifa->an==oa->areaid) && (ifa->state!=OSPF_IS_DOWN))
{
i++;
if(ifa->type==OSPF_IT_VLINK) v=1;
}
}
rt=mb_allocz(p->proto.pool, sizeof(struct ospf_lsa_rt)+
i*sizeof(struct ospf_lsa_rt_link));
if(p->areano>1) rt->veb.bit.b=1;
if((p->ebit)&&(!oa->stub)) rt->veb.bit.e=1;
rt->veb.bit.v=v;
ln=(struct ospf_lsa_rt_link *)(rt+1);
WALK_LIST (ifa, p->iface_list)
{
if((ifa->an!=oa->areaid) || (ifa->state==OSPF_IS_DOWN)) continue;
if(ifa->state==OSPF_IS_LOOP)
{
ln->type=3;
ln->id=ipa_to_u32(ifa->iface->addr->ip);
ln->data=0xffffffff;
ln->metric=0;
ln->notos=0;
}
else
{
switch(ifa->type)
{
case OSPF_IT_PTP: /* rfc2328 - pg126 */
neigh=(struct ospf_neighbor *)HEAD(ifa->neigh_list);
if((!EMPTY_LIST(ifa->neigh_list)) && (neigh->state==NEIGHBOR_FULL))
{
ln->type=LSART_PTP;
ln->id=neigh->rid;
ln->metric=ifa->cost;
ln->notos=0;
if(ifa->iface->flags && IA_UNNUMBERED)
{
ln->data=ifa->iface->index;
}
else
{
ln->id=ipa_to_u32(ifa->iface->addr->ip);
}
}
else
{
if(ifa->state==OSPF_IS_PTP)
{
ln->type=LSART_STUB;
ln->id=ln->id=ipa_to_u32(ifa->iface->addr->opposite);
ln->metric=ifa->cost;
ln->notos=0;
ln->data=0xffffffff;
}
else
{
i--; /* No link added */
}
}
break;
case OSPF_IT_BCAST:
case OSPF_IT_NBMA:
if(ifa->state==OSPF_IS_WAITING)
{
ln->type=LSART_STUB;
ln->id=ipa_to_u32(ifa->iface->addr->prefix);
ln->data=ipa_to_u32(ipa_mkmask(ifa->iface->addr->pxlen));
ln->metric=ifa->cost;
ln->notos=0;
}
else
{
j=0,k=0;
WALK_LIST(neigh, ifa->neigh_list)
{
if((neigh->rid==ifa->drid) &&
(neigh->state==NEIGHBOR_FULL)) k=1;
if(neigh->state==NEIGHBOR_FULL) j=1;
}
if(((ifa->state==OSPF_IS_DR) && (j==1)) || (k==1))
{
ln->type=LSART_NET;
ln->id=ipa_to_u32(ifa->drip);
ln->data=ipa_to_u32(ifa->iface->addr->ip);
ln->metric=ifa->cost;
ln->notos=0;
}
else
{
ln->type=LSART_STUB;
ln->id=ipa_to_u32(ifa->iface->addr->prefix);
ln->data=ipa_to_u32(ipa_mkmask(ifa->iface->addr->pxlen));
ln->metric=ifa->cost;
ln->notos=0;
}
}
break;
case OSPF_IT_VLINK: /* FIXME Add virtual links! */
i--;
break;
}
}
if(ifa->type==OSPF_IT_VLINK) v=1;
ln=(ln+1);
}
rt->links=i;
*length=i*sizeof(struct ospf_lsa_rt_link)+sizeof(struct ospf_lsa_rt)+
sizeof(struct ospf_lsa_header);
return rt;
}
void
addifa_rtlsa(struct ospf_iface *ifa)
{
struct ospf_area *oa;
struct proto_ospf *po=ifa->proto;
struct proto *p=&po->proto;
WALK_LIST(NODE oa,po->area_list)
{
if(oa->areaid==ifa->an) break;
}
if(EMPTY_LIST(po->area_list) || (oa->areaid!=ifa->an)) /* New area */
{
bug("Cannot add any area to accepted Interface");
}
else ifa->oa=oa;
}
/**
* originate_rt_lsa - build new instance of router LSA
* @oa: ospf_area which is LSA built to
*
* It builds router LSA walking through all OSPF interfaces in
* specified OSPF area. This function is mostly called from
* area_disp(). Builds new LSA, increases sequence number (if old
* instance exists) and sets age of LSA to zero.
*/
void
originate_rt_lsa(struct ospf_area *oa)
{
struct ospf_lsa_header lsa;
struct proto_ospf *po=oa->po;
struct proto *p=&po->proto;
u32 rtid=po->proto.cf->global->router_id;
struct top_hash_entry *en;
void *body;
if((oa->rt)&&((oa->rt->inst_t+MINLSINTERVAL))>now) return;
/*
* Tick is probably set to very low value. We cannot
* originate new LSA before MINLSINTERVAL. We will
* try to do it next tick.
*/
OSPF_TRACE(D_EVENTS, "Originating RT_lsa for area \"%I\".",oa->areaid);
lsa.age=0;
lsa.id=rtid;
lsa.type=LSA_T_RT;
lsa.rt=rtid;
lsa.options=0;
if(oa->rt==NULL)
{
lsa.sn=LSA_INITSEQNO;
}
else
{
lsa.sn=oa->rt->lsa.sn+1;
}
body=originate_rt_lsa_body(oa, &lsa.length, po);
lsasum_calculate(&lsa,body,po);
en=lsa_install_new(&lsa, body, oa);
oa->rt=en;
flood_lsa(NULL,NULL,&oa->rt->lsa,po,NULL,oa,1);
schedule_rtcalc(oa);
oa->origrt=0;
}
void *
originate_net_lsa_body(struct ospf_iface *ifa, u16 *length,
struct proto_ospf *po)
{
u16 i=1;
struct ospf_neighbor *n;
u32 *body;
struct ospf_lsa_net *net;
net=mb_alloc(po->proto.pool,sizeof(u32)*(ifa->fadj+1)+
sizeof(struct ospf_lsa_net));
net->netmask=ipa_mkmask(ifa->iface->addr->pxlen);
body=(u32 *)(net+1);
i=1;
*body=po->proto.cf->global->router_id;
WALK_LIST(n,ifa->neigh_list)
{
if(n->state==NEIGHBOR_FULL)
{
*(body+i)=n->rid;
i++;
}
}
*length=i*sizeof(u32)+sizeof(struct ospf_lsa_header)+
sizeof(struct ospf_lsa_net);
return net;
}
/**
* originate_net_lsa - originates of deletes network LSA
* @ifa: interface which is LSA originated for
*
* Interface counts number of adjacent neighbors. If this number is
* lower than one or interface is not in state %OSPF_IS_DR it deletes
* and premature ages instance of network LSA for specified interface.
* In other case, new instance of network LSA is originated.
*/
void
originate_net_lsa(struct ospf_iface *ifa)
{
struct proto_ospf *po=ifa->proto;
struct ospf_lsa_header lsa;
u32 rtid=po->proto.cf->global->router_id;
struct top_hash_entry *en;
struct proto *p=&po->proto;
void *body;
if(ifa->nlsa&&((ifa->nlsa->inst_t+MINLSINTERVAL)>now)) return;
/*
* It's too early to originate new network LSA. We will
* try to do it next tick
*/
if((ifa->state!=OSPF_IS_DR)||(ifa->fadj==0))
{
if(ifa->nlsa==NULL) return;
OSPF_TRACE(D_EVENTS, "Deleting Net lsa for iface \"%s\".",
ifa->iface->name);
ifa->nlsa->lsa.sn+=1;
ifa->nlsa->lsa.age=LSA_MAXAGE;
flood_lsa(NULL,NULL,&ifa->nlsa->lsa,po,NULL,ifa->oa,0);
s_rem_node(SNODE ifa->nlsa);
if(ifa->nlsa->lsa_body!=NULL) mb_free(ifa->nlsa->lsa_body);
ifa->nlsa->lsa_body=NULL;
ospf_hash_delete(ifa->oa->gr, ifa->nlsa);
schedule_rtcalc(ifa->oa);
ifa->nlsa=NULL;
return ;
}
OSPF_TRACE(D_EVENTS, "Originating Net lsa for iface \"%s\".",
ifa->iface->name);
lsa.age=0;
lsa.id=ipa_to_u32(ifa->iface->addr->ip);
lsa.type=LSA_T_NET;
lsa.rt=rtid;
lsa.options=0;
if(ifa->nlsa==NULL)
{
lsa.sn=LSA_INITSEQNO;
}
else
{
lsa.sn=ifa->nlsa->lsa.sn+1;
}
body=originate_net_lsa_body(ifa, &lsa.length, po);
lsasum_calculate(&lsa,body,po);
ifa->nlsa=lsa_install_new(&lsa, body, ifa->oa);
flood_lsa(NULL,NULL,&ifa->nlsa->lsa,po,NULL,ifa->oa,1);
ifa->orignet=0;
}
static void *
originate_ext_lsa_body(net *n, rte *e, struct proto_ospf *po, struct ea_list *attrs)
{
struct proto *p=&po->proto;
struct ospf_lsa_ext *ext;
struct ospf_lsa_ext_tos *et;
neighbor *nn;
u32 m1 = ea_get_int(attrs, EA_OSPF_METRIC1, LSINFINITY);
u32 m2 = ea_get_int(attrs, EA_OSPF_METRIC2, 10000);
u32 tag = ea_get_int(attrs, EA_OSPF_TAG, 0);
int inas=0;
ext=mb_alloc(p->pool,sizeof(struct ospf_lsa_ext)+
sizeof(struct ospf_lsa_ext_tos));
ext->netmask=ipa_mkmask(n->n.pxlen);
et=(struct ospf_lsa_ext_tos *)(ext+1);
if(m1!=LSINFINITY)
{
et->etos=0;
et->metric=m1;
}
else
{
et->etos=0x80;
et->metric=m2;
}
et->padding=0;
et->tag=tag;
if(ipa_compare(e->attrs->gw,ipa_from_u32(0))!=0)
{
if(find_iface((struct proto_ospf *)p, e->attrs->iface)!=NULL) inas=1;
}
if(!inas) et->fwaddr= ipa_from_u32(0);
else et->fwaddr=e->attrs->gw;
return ext;
}
/**
* max_ext_lsa - calculate the maximum amount of external networks
* possible for the given prefix length.
* @pxlen: network prefix length
*
* This is a fix for the previous static use of MAXNETS which did
* only work correct if MAXNETS < possible IPs for given prefix.
* This solution is kind of a hack as there can now only be one
* route for /32 type entries but this is better than the crashes
* I did experience whith close together /32 routes originating
* on different hosts.
*/
int
max_ext_lsa(unsigned pxlen)
{
int i;
for(i=1;pxlen<BITS_PER_IP_ADDRESS;pxlen++,i<<=1)
if(i>=MAXNETS)
return MAXNETS;
return i;
}
/**
* originate_ext_lsa - new route received from nest and filters
* @n: network prefix and mask
* @e: rte
* @po: current instance of OSPF
* @attrs: list of extended attributes
*
* If I receive a message that new route is installed, I try to originate an
* external LSA. The LSA header of such LSA does not contain information about
* prefix length, so if I have to originate multiple LSAs for route with
* different prefixes I try to increment prefix id to find a "free" one.
*
* The function also sets flag ebit. If it's the first time, the new router lsa
* origination is necessary.
*/
void
originate_ext_lsa(net *n, rte *e, struct proto_ospf *po, struct ea_list *attrs)
{
struct ospf_lsa_header lsa;
u32 rtid=po->proto.cf->global->router_id;
struct top_hash_entry *en=NULL;
void *body=NULL;
struct proto *p=&po->proto;
struct ospf_area *oa;
struct ospf_lsa_ext *ext1,*ext2;
int i;
int max;
OSPF_TRACE(D_EVENTS, "Originating Ext lsa for %I/%d.", n->n.prefix,
n->n.pxlen);
lsa.age=0;
lsa.id=ipa_to_u32(n->n.prefix);
lsa.type=LSA_T_EXT;
lsa.rt=rtid;
lsa.sn=LSA_INITSEQNO;
body=originate_ext_lsa_body(n, e, po, attrs);
lsa.length=sizeof(struct ospf_lsa_ext)+sizeof(struct ospf_lsa_ext_tos)+
sizeof(struct ospf_lsa_header);
ext1=body;
max=max_ext_lsa(n->n.pxlen);
oa=HEAD(po->area_list);
for(i=0;i<max;i++)
{
if((en=ospf_hash_find_header(oa->gr, &lsa))!=NULL)
{
ext2=en->lsa_body;
if(ipa_compare(ext1->netmask,ext2->netmask)!=0) lsa.id++;
else break;
}
else break;
}
if(i==max)
{
log("%s: got more routes for one /%d network then %d, ignoring",p->name,
n->n.pxlen,max);
mb_free(body);
return;
}
lsasum_calculate(&lsa,body,po);
WALK_LIST(oa, po->area_list)
{
en=lsa_install_new(&lsa, body, oa);
flood_lsa(NULL,NULL,&en->lsa,po,NULL,oa,1);
body=originate_ext_lsa_body(n, e, po, attrs);
}
mb_free(body);
if(po->ebit==0)
{
po->ebit=1;
WALK_LIST(oa, po->area_list)
{
schedule_rt_lsa(oa);
}
}
}
static void
ospf_top_ht_alloc(struct top_graph *f)
{
f->hash_size = 1 << f->hash_order;
f->hash_mask = f->hash_size - 1;
if (f->hash_order > HASH_HI_MAX - HASH_HI_STEP)
f->hash_entries_max = ~0;
else
f->hash_entries_max = f->hash_size HASH_HI_MARK;
if (f->hash_order < HASH_LO_MIN + HASH_LO_STEP)
f->hash_entries_min = 0;
else
f->hash_entries_min = f->hash_size HASH_LO_MARK;
DBG("Allocating OSPF hash of order %d: %d hash_entries, %d low, %d high\n",
f->hash_order, f->hash_size, f->hash_entries_min, f->hash_entries_max);
f->hash_table = mb_alloc(f->pool, f->hash_size * sizeof(struct top_hash_entry *));
bzero(f->hash_table, f->hash_size * sizeof(struct top_hash_entry *));
}
static inline void
ospf_top_ht_free(struct top_hash_entry **h)
{
mb_free(h);
}
static inline u32
ospf_top_hash_u32(u32 a)
{
/* Shamelessly stolen from IP address hashing in ipv4.h */
a ^= a >> 16;
a ^= a << 10;
return a;
}
static inline unsigned
ospf_top_hash(struct top_graph *f, u32 lsaid, u32 rtrid, u32 type)
{
#if 1 /* Dirty patch to make rt table calculation work. */
return (ospf_top_hash_u32(lsaid) + ospf_top_hash_u32((type==LSA_T_NET) ? lsaid : rtrid) + type) & f->hash_mask;
#else
return (ospf_top_hash_u32(lsaid) + ospf_top_hash_u32(rtrid) + type) & f->hash_mask;
#endif
}
/**
* ospf_top_new - allocated new topology database
* @p: current instance of OSPF
*
* This dynamically hashed structure is often used for keeping LSAs. Mainly
* its used in @ospf_area structure.
*/
struct top_graph *
ospf_top_new(pool *pool, struct proto_ospf *p)
{
struct top_graph *f;
f = mb_allocz(pool, sizeof(struct top_graph));
f->pool = pool;
f->hash_slab = sl_new(f->pool, sizeof(struct top_hash_entry));
f->hash_order = HASH_DEF_ORDER;
ospf_top_ht_alloc(f);
f->hash_entries = 0;
f->hash_entries_min = 0;
return f;
}
void
ospf_top_free(struct top_graph *f)
{
rfree(f->hash_slab);
ospf_top_ht_free(f->hash_table);
mb_free(f);
}
static void
ospf_top_rehash(struct top_graph *f, int step)
{
unsigned int oldn, oldh;
struct top_hash_entry **n, **oldt, **newt, *e, *x;
oldn = f->hash_size;
oldt = f->hash_table;
DBG("Re-hashing topology hash from order %d to %d\n", f->hash_order, f->hash_order+step);
f->hash_order += step;
ospf_top_ht_alloc(f);
newt = f->hash_table;
for(oldh=0; oldh < oldn; oldh++)
{
e = oldt[oldh];
while (e)
{
x = e->next;
n = newt + ospf_top_hash(f, e->lsa.id, e->lsa.rt, e->lsa.type);
e->next = *n;
*n = e;
e = x;
}
}
ospf_top_ht_free(oldt);
}
struct top_hash_entry *
ospf_hash_find_header(struct top_graph *f, struct ospf_lsa_header *h)
{
return ospf_hash_find(f,h->id,h->rt,h->type);
}
struct top_hash_entry *
ospf_hash_get_header(struct top_graph *f, struct ospf_lsa_header *h)
{
return ospf_hash_get(f,h->id,h->rt,h->type);
}
struct top_hash_entry *
ospf_hash_find(struct top_graph *f, u32 lsa, u32 rtr, u32 type)
{
struct top_hash_entry *e = f->hash_table[ospf_top_hash(f, lsa, rtr, type)];
#if 1 /* Dirty patch to make rt table calculation work. */
if(type==LSA_T_NET)
{
while (e && (e->lsa.id != lsa || e->lsa.type != LSA_T_NET ))
e = e->next;
}
else
{
while (e && (e->lsa.id != lsa || e->lsa.type != type || e->lsa.rt != rtr))
e = e->next;
}
#else
while (e && (e->lsa.id != lsa || e->lsa.rt != rtr || e->lsa.type != type))
e = e->next;
#endif
return e;
}
struct top_hash_entry *
ospf_hash_get(struct top_graph *f, u32 lsa, u32 rtr, u32 type)
{
struct top_hash_entry **ee = f->hash_table + ospf_top_hash(f, lsa, rtr, type);
struct top_hash_entry *e = *ee;
while (e && (e->lsa.id != lsa || e->lsa.rt != rtr || e->lsa.type != type))
e = e->next;
if (e)
return e;
e = sl_alloc(f->hash_slab);
e->lsa.id = lsa;
e->lsa.rt = rtr;
e->lsa.type = type;
e->lsa_body = NULL;
e->nhi=NULL;
e->next=*ee; /* MJ you forgot this :-) */
*ee=e;
if (f->hash_entries++ > f->hash_entries_max)
ospf_top_rehash(f, HASH_HI_STEP);
return e;
}
void
ospf_hash_delete(struct top_graph *f, struct top_hash_entry *e)
{
unsigned int h = ospf_top_hash(f, e->lsa.id, e->lsa.rt, e->lsa.type);
struct top_hash_entry **ee = f->hash_table + h;
while (*ee)
{
if (*ee == e)
{
*ee = e->next;
sl_free(f->hash_slab, e);
if (f->hash_entries-- < f->hash_entries_min)
ospf_top_rehash(f, -HASH_LO_STEP);
return;
}
ee = &((*ee)->next);
}
bug("ospf_hash_delete() called for invalid node");
}
void
ospf_top_dump(struct top_graph *f, struct proto *p)
{
unsigned int i;
OSPF_TRACE(D_EVENTS, "Hash entries: %d", f->hash_entries);
for(i=0; i<f->hash_size; i++)
{
struct top_hash_entry *e = f->hash_table[i];
while (e)
{
OSPF_TRACE(D_EVENTS, "\t%1x %-1I %-1I %4u 0x%08x",
e->lsa.type, e->lsa.id,
e->lsa.rt, e->lsa.age, e->lsa.sn);
e = e->next;
}
}
}
/* This is very inefficient, please don't call it often */
/* I should also test for every LSA if it's in some link state
* retransmission list for every neighbor. I will not test it.
* It could happen that I'll receive some strange ls ack's.
*/
int
can_flush_lsa(struct ospf_area *oa)
{
struct ospf_iface *ifa;
struct ospf_neighbor *n;
struct proto_ospf *po=oa->po;
WALK_LIST(ifa, iface_list)
{
if(ifa->oa==oa)
{
WALK_LIST(n, ifa->neigh_list)
{
if((n->state==NEIGHBOR_EXCHANGE)||(n->state==NEIGHBOR_LOADING))
{
return 0;
}
}
}
}
return 1;
}
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