Work on lsupdates continues. Some checksum cleanup.

This commit is contained in:
Ondrej Filip 2000-04-02 20:41:33 +00:00
parent db9fb72769
commit 394acced11
5 changed files with 78 additions and 41 deletions

View file

@ -189,11 +189,10 @@ ospf_dbdes_reqladd(struct ospf_dbdes_packet *ps, struct proto *p,
for(i=0;i<j;i++)
{
ntohlsah(plsa+i, &lsa);
/* FIXME Test Checksum */
if(((he=ospf_hash_find(gr,lsa.id,lsa.rt,lsa.type))==NULL)||
(lsa_comp(&lsa, &(he->lsa))==1))
{
/* Is this confition necessary? */
/* Is this condition necessary? */
if(ospf_hash_find(n->lsrqh,lsa.id,lsa.rt,lsa.type)==NULL)
{
sn=ospf_hash_get(n->lsrqh,lsa.id,lsa.rt,lsa.type);

View file

@ -230,40 +230,60 @@ ntohlsab(void *n, void *h, u8 type, u16 len)
#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;
u16 length,chsum;
h->checksum = 0;
b=body;
length = h->length-2;
sp = (char *) &h->options;
htonlsah(h,h);
htonlsab(b,b,h->type,length+2);
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;
if (q > ep) q = ep;
for (p = sp; p < q; p++)
{
if(p<(u8 *)(h+1))
/*
* 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;
/*DBG("XXXXXX: %u\t%u\n", p-sp, *p);*/
}
else
{
c0 += *(b+(p-sp)-sizeof(struct ospf_lsa_header)+2);
/*DBG("YYYYYY: %u\t%u\n", p-sp,*(b+(p-sp)-sizeof(struct ospf_lsa_header)+2));*/
}
c1 += c0;
}
c0 %= 255;
@ -271,21 +291,18 @@ lsasum_calculate(struct ospf_lsa_header *h,void *body,struct proto_ospf *po)
}
x = ((length - LSA_CHECKSUM_OFFSET) * c0 - c1) % 255;
if (x <= 0)
x += 255;
if (x <= 0) x += 255;
y = 510 - c0 - x;
if (y > 255)
y -= 255;
if (y > 255) y -= 255;
h->checksum = x + (y << 8);
ntohlsah(h,h);
ntohlsab(b,b,h->type,length+2);
chsum= x + (y << 8);
h->checksum = chsum;
return chsum;
}
int
lsa_comp(struct ospf_lsa_header *l1, struct ospf_lsa_header *l2)
/* Return codes form view of l1 */
/* Return codes from point of view of l1 */
{
if(l1->sn<l2->sn) return CMP_NEWER;
if(l1->sn==l2->sn)

View file

@ -16,6 +16,8 @@ void htonlsab(void *h, void *n, u8 type, u16 len);
void ntohlsab(void *n, void *h, u8 type, u16 len);
void lsasum_calculate(struct ospf_lsa_header *header, void *body,
struct proto_ospf *p);
u16 lsasum_check(struct ospf_lsa_header *h,void *body,struct proto_ospf *po);
#define CMP_NEWER 1
#define CMP_SAME 0
#define CMP_OLDER -1

View file

@ -83,10 +83,10 @@ void
ospf_lsupd_rx(struct ospf_lsupd_packet *ps, struct proto *p,
struct ospf_iface *ifa, u16 size)
{
u32 nrid, myrid;
u32 area,nrid,myrid;
struct ospf_neighbor *n;
struct ospf_lsreq_header *lsh;
int length;
struct ospf_lsa_header *lsa;
u16 length;
u8 i;
nrid=ntohl(ps->ospf_packet.routerid);
@ -99,6 +99,24 @@ ospf_lsupd_rx(struct ospf_lsupd_packet *ps, struct proto *p,
nrid);
return ;
}
/* FIXME Go on! */
if(n->state<NEIGHBOR_EXCHANGE)
{
debug("%s: Received lsupd in lesser state than EXCHANGE from (%u)\n",
p->name);
return;
}
lsa=(struct ospf_lsa_header *)(ps+1);
area=htonl(ps->ospf_packet.areaid);
for(i=0;i<ntohl(ps->lsano);i++)
{
if(lsa->checksum==lsasum_check(lsa,NULL,(struct proto_ospf *)p))
{
DBG("Processing update Type: %u ID: %u RT: %u\n",lsa->type,
ntohl(lsa->id), ntohl(lsa->rt));
/* FIXME Go on */
}
lsa=(struct ospf_lsa_header *)(((u8 *)lsa)+ntohs(lsa->length));
}
}

View file

@ -145,6 +145,7 @@ ospf_rx_hook(sock *sk, int size)
break;
case LSUPD:
DBG("%s: Link state update received.\n", p->name);
ospf_lsupd_rx((struct ospf_lsupd_packet *)ps, p, ifa, size);
break;
case LSACK:
DBG("%s: Link state ack received.\n", p->name);