mirror of
https://gitlab.nic.cz/labs/bird.git
synced 2024-12-22 17:51:53 +00:00
372 lines
8.1 KiB
C
372 lines
8.1 KiB
C
/*
|
|
* 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"
|
|
|
|
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=htonl((ht+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=ntohl((nt+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);
|
|
|
|
(void)lsasum_check(h,body,po);
|
|
|
|
ntohlsah(h,h);
|
|
ntohlsab(body,body,h->type,length);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|
|
/* FIXME delete routes to stub networks! */
|
|
}
|
|
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;
|
|
en->lsa.length=lsa->length;
|
|
memcpy(&en->lsa,lsa,sizeof(struct ospf_lsa_header));
|
|
/* FIXME decide if route calcualtion must be done and how */
|
|
if(oa->rt!=NULL)
|
|
{
|
|
DBG("Starting routing table calculation.\n");
|
|
ospf_rt_spfa(oa, p);
|
|
}
|
|
}
|
|
|
|
return en;
|
|
}
|