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bird/proto/ospf/lsalib.c
Ondrej Filip 7f6b3cf247 Typo in comment.
2000-05-17 00:28:11 +00:00

402 lines
8.7 KiB
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/*
* BIRD -- OSPF
*
* (c) 1999-2000 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "ospf.h"
/* FIXME Go on */
void
flush_lsa(struct top_hash_entry *en, struct ospf_area *oa)
{
s_rem_node(SNODE en);
ospf_hash_delete(oa->gr,en);
}
void
ospf_age(struct top_hash_entry *en, bird_clock_t delta, int flush,
struct ospf_area *oa)
{
struct proto *p=&oa->po->proto;
if(en->lsa.age==LSA_MAXAGE)
{
if(flush) flush_lsa(en,oa);
return;
}
if((en->lsa.rt==p->cf->global->router_id)&&(en->lsa.age>LSREFRESHTIME))
{
/* FIXME Reflood again my self originated LSA */
}
if((en->lsa.age+=delta)>LSA_MAXAGE)
{
if(flush) flush_lsa(en,oa);
else en->lsa.age=LSA_MAXAGE;
return;
}
}
void
htonlsah(struct ospf_lsa_header *h, struct ospf_lsa_header *n)
{
n->age=htons(h->age);
n->options=h->options;
n->type=h->type;
n->id=htonl(h->id);
n->rt=htonl(h->rt);
n->sn=htonl(h->sn);
n->checksum=htons(h->checksum);
n->length=htons(h->length);
};
void
ntohlsah(struct ospf_lsa_header *n, struct ospf_lsa_header *h)
{
h->age=ntohs(n->age);
h->options=n->options;
h->type=n->type;
h->id=ntohl(n->id);
h->rt=ntohl(n->rt);
h->sn=ntohl(n->sn);
h->checksum=ntohs(n->checksum);
h->length=ntohs(n->length);
};
void
htonlsab(void *h, void *n, u8 type, u16 len)
{
unsigned int i;
switch(type)
{
case LSA_T_RT:
{
struct ospf_lsa_rt *hrt, *nrt;
struct ospf_lsa_rt_link *hrtl,*nrtl;
u16 links;
nrt=n;
hrt=h;
links=hrt->links;
nrt->VEB=hrt->VEB;
nrt->padding=0;
nrt->links=htons(hrt->links);
nrtl=(struct ospf_lsa_rt_link *)(nrt+1);
hrtl=(struct ospf_lsa_rt_link *)(hrt+1);
for(i=0;i<links;i++)
{
(nrtl+i)->id=htonl((hrtl+i)->id);
(nrtl+i)->data=htonl((hrtl+i)->data);
(nrtl+i)->type=(hrtl+i)->type;
(nrtl+i)->notos=(hrtl+i)->notos;
(nrtl+i)->metric=htons((hrtl+i)->metric);
}
break;
}
case LSA_T_NET:
{
u32 *hid,*nid;
nid=n;
hid=h;
for(i=0;i<(len/sizeof(u32));i++)
{
*(nid+i)=htonl(*(hid+i));
}
break;
}
case LSA_T_SUM_NET:
case LSA_T_SUM_RT:
{
struct ospf_lsa_summ *hs, *ns;
struct ospf_lsa_summ_net *hn, *nn;
hs=h;
ns=n;
ns->netmask=ipa_hton(hs->netmask);
hn=(struct ospf_lsa_summ_net *)(hs+1);
nn=(struct ospf_lsa_summ_net *)(ns+1);
for(i=0;i<((len-sizeof(struct ospf_lsa_summ))/
sizeof(struct ospf_lsa_summ_net));i++)
{
(nn+i)->tos=(hn+i)->tos;
(nn+i)->metric=htons((hn+i)->metric);
(nn+i)->padding=0;
}
break;
}
case LSA_T_EXT:
{
struct ospf_lsa_ext *he, *ne;
struct ospf_lsa_ext_tos *ht, *nt;
he=h;
ne=n;
ne->netmask=ipa_hton(he->netmask);
ht=(struct ospf_lsa_ext_tos *)(he+1);
nt=(struct ospf_lsa_ext_tos *)(ne+1);
for(i=0;i<((len-sizeof(struct ospf_lsa_ext))/
sizeof(struct ospf_lsa_ext_tos));i++)
{
(nt+i)->etos=(ht+i)->etos;
(nt+i)->padding=0;
(nt+i)->metric=htons((ht+i)->metric);
(nt+i)->fwaddr=(ht+i)->fwaddr;
ipa_hton((nt+i)->fwaddr);
(nt+i)->tag=htonl((ht+i)->tag);
}
break;
}
default: die("(hton): Unknown LSA\n");
}
};
void
ntohlsab(void *n, void *h, u8 type, u16 len)
{
unsigned int i;
switch(type)
{
case LSA_T_RT:
{
struct ospf_lsa_rt *hrt, *nrt;
struct ospf_lsa_rt_link *hrtl,*nrtl;
u16 links;
nrt=n;
hrt=h;
hrt->VEB=nrt->VEB;
hrt->padding=0;
links=hrt->links=ntohs(nrt->links);
nrtl=(struct ospf_lsa_rt_link *)(nrt+1);
hrtl=(struct ospf_lsa_rt_link *)(hrt+1);
for(i=0;i<links;i++)
{
(hrtl+i)->id=ntohl((nrtl+i)->id);
(hrtl+i)->data=ntohl((nrtl+i)->data);
(hrtl+i)->type=(nrtl+i)->type;
(hrtl+i)->notos=(nrtl+i)->notos;
(hrtl+i)->metric=ntohs((nrtl+i)->metric);
}
break;
}
case LSA_T_NET:
{
u32 *hid,*nid;
hid=h;
nid=n;
for(i=0;i<(len/sizeof(u32));i++)
{
*(hid+i)=ntohl(*(nid+i));
}
break;
}
case LSA_T_SUM_NET:
case LSA_T_SUM_RT:
{
struct ospf_lsa_summ *hs, *ns;
struct ospf_lsa_summ_net *hn, *nn;
hs=h;
ns=n;
hs->netmask=ipa_ntoh(ns->netmask);
hn=(struct ospf_lsa_summ_net *)(hs+1);
nn=(struct ospf_lsa_summ_net *)(ns+1);
for(i=0;i<((len-sizeof(struct ospf_lsa_summ))/
sizeof(struct ospf_lsa_summ_net));i++)
{
(hn+i)->tos=(nn+i)->tos;
(hn+i)->metric=ntohs((nn+i)->metric);
(hn+i)->padding=0;
}
break;
}
case LSA_T_EXT:
{
struct ospf_lsa_ext *he, *ne;
struct ospf_lsa_ext_tos *ht, *nt;
he=h;
ne=n;
he->netmask=ipa_ntoh(ne->netmask);
ht=(struct ospf_lsa_ext_tos *)(he+1);
nt=(struct ospf_lsa_ext_tos *)(ne+1);
for(i=0;i<((len-sizeof(struct ospf_lsa_ext))/
sizeof(struct ospf_lsa_ext_tos));i++)
{
(ht+i)->etos=(nt+i)->etos;
(ht+i)->padding=0;
(ht+i)->metric=ntohs((nt+i)->metric);
(ht+i)->fwaddr=(nt+i)->fwaddr;
ipa_ntoh((ht+i)->fwaddr);
(ht+i)->tag=ntohl((nt+i)->tag);
}
break;
}
default: die("(ntoh): Unknown LSA\n");
}
};
#define MODX 4102 /* larges signed value without overflow */
/* Fletcher Checksum -- Refer to RFC1008. */
#define MODX 4102
#define LSA_CHECKSUM_OFFSET 15
/* FIXME This is VERY uneficient, I have huge endianity problems */
void
lsasum_calculate(struct ospf_lsa_header *h,void *body,struct proto_ospf *po)
{
u16 length;
length=h->length;
htonlsah(h,h);
htonlsab(body,body,h->type,length-sizeof(struct ospf_lsa_header));
(void)lsasum_check(h,body,po);
ntohlsah(h,h);
ntohlsab(body,body,h->type,length-sizeof(struct ospf_lsa_header));
}
/*
* Note, that this function expects that LSA is in big endianity
* It also returns value in big endian
*/
u16
lsasum_check(struct ospf_lsa_header *h,void *body,struct proto_ospf *po)
{
u8 *sp, *ep, *p, *q, *b;
int c0 = 0, c1 = 0;
int x, y;
u16 length,chsum;
b=body;
sp = (char *) &h->options;
length=ntohs(h->length)-2;
h->checksum = 0;
for (ep = sp + length; sp < ep; sp = q)
{ /* Actually MODX is very large, do we need the for-cyclus? */
q = sp + MODX;
if (q > ep) q = ep;
for (p = sp; p < q; p++)
{
/*
* I count with bytes from header and than from body
* but if there is no body, it's appended to header
* (probably checksum in update receiving) and I go on
* after header
*/
if((b==NULL) || (p<(u8 *)(h+1)))
{
c0 += *p;
}
else
{
c0 += *(b+(p-sp)-sizeof(struct ospf_lsa_header)+2);
}
c1 += c0;
}
c0 %= 255;
c1 %= 255;
}
x = ((length - LSA_CHECKSUM_OFFSET) * c0 - c1) % 255;
if (x <= 0) x += 255;
y = 510 - c0 - x;
if (y > 255) y -= 255;
chsum= x + (y << 8);
h->checksum = chsum;
return chsum;
}
int
lsa_comp(struct ospf_lsa_header *l1, struct ospf_lsa_header *l2)
/* Return codes from point of view of l1 */
{
if(l1->sn<l2->sn) return CMP_NEWER;
if(l1->sn==l2->sn)
{
if(l1->checksum=!l2->checksum)
return l1->checksum<l2->checksum ? CMP_OLDER : CMP_NEWER;
if(l1->age==LSA_MAXAGE) return CMP_NEWER;
if(l2->age==LSA_MAXAGE) return CMP_OLDER;
if(abs(l1->age-l2->age)>LSA_MAXAGEDIFF)
return l1->age<l2->age ? CMP_NEWER : CMP_OLDER;
}
return CMP_SAME;
}
/* LSA can be temporarrily, but body must be mb_alloced. */
struct top_hash_entry *
lsa_install_new(struct ospf_lsa_header *lsa, void *body, struct ospf_area *oa,
struct proto *p)
{
int change=0;
unsigned i;
struct top_hash_entry *en;
if((en=ospf_hash_find_header(oa->gr,lsa))==NULL)
{
en=ospf_hash_get_header(oa->gr,lsa);
change=1;
}
else
{
if((en->lsa.length!=lsa->length)||(en->lsa.options!=lsa->options)||
((en->lsa.age==LSA_MAXAGE)||(lsa->age==LSA_MAXAGE))) change=1;
else
{
u8 *k=en->lsa_body,*l=body;
for(i=0;i<(lsa->length-sizeof(struct ospf_lsa_header));i++)
{
if(*(k+i)!=*(l+i))
{
change=1;
break;
}
}
}
if(change) s_rem_node(SNODE en);
}
if(change)
{
s_add_tail(&oa->lsal, SNODE en);
en->inst_t=now;
if(en->lsa_body!=NULL) mb_free(en->lsa_body);
en->lsa_body=body;
memcpy(&en->lsa,lsa,sizeof(struct ospf_lsa_header));
/* FIXME decide if route calculation must be done and how */
if(oa->rt!=NULL)
{
DBG("Starting routing table calculation.\n");
ospf_rt_spfa(oa);
}
}
return en;
}
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