void
lsa_generate_checksum(struct ospf_lsa_header *lsa, const u8 *body)
{
struct fletcher16_context ctx;
struct ospf_lsa_header hdr;
u16 len = lsa->length;
/*
* lsa and body are in the host order, we need to compute Fletcher-16 checksum
* for data in the network order. We also skip the initial age field.
*/
lsa_hton_hdr(lsa, &hdr);
hdr.checksum = 0;
fletcher16_init(&ctx);
fletcher16_update(&ctx, (u8 *) &hdr + 2, sizeof(struct ospf_lsa_header) - 2);
fletcher16_update_n32(&ctx, body, len - sizeof(struct ospf_lsa_header));
lsa->checksum = fletcher16_final(&ctx, len, OFFSETOF(struct ospf_lsa_header, checksum));
}
/* FIXME This is VERY uneficient, I have huge endianity problems */
void
lsasum_calculate(struct ospf_lsa_header *h, void *body)
{
u16 length = h->length;
// log(L_WARN "Checksum %R %R %d start (len %d)", h->id, h->rt, h->type, length);
lsa_hton_hdr(h, h);
lsa_hton_body1(body, length - sizeof(struct ospf_lsa_header));
/*
char buf[1024];
memcpy(buf, h, sizeof(struct ospf_lsa_header));
memcpy(buf + sizeof(struct ospf_lsa_header), body, length - sizeof(struct ospf_lsa_header));
buf_dump("CALC", buf, length);
*/
(void) lsasum_check(h, body, 1);
// log(L_WARN "Checksum result %4x", h->checksum);
lsa_ntoh_hdr(h, h);
lsa_ntoh_body1(body, length - sizeof(struct ospf_lsa_header));
}
static void
ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_packet *pkt;
uint length;
u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;
/* Update DBDES buffer */
if (n->ldd_bsize != ifa->tx_length)
{
mb_free(n->ldd_buffer);
n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
n->ldd_bsize = ifa->tx_length;
}
pkt = n->ldd_buffer;
ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
if (ospf_is_v2(p))
{
struct ospf_dbdes2_packet *ps = (void *) pkt;
ps->iface_mtu = htons(iface_mtu);
ps->options = ifa->oa->options;
ps->imms = 0; /* Will be set later */
ps->ddseq = htonl(n->dds);
length = sizeof(struct ospf_dbdes2_packet);
}
else /* OSPFv3 */
{
struct ospf_dbdes3_packet *ps = (void *) pkt;
ps->options = htonl(ifa->oa->options);
ps->iface_mtu = htons(iface_mtu);
ps->padding = 0;
ps->imms = 0; /* Will be set later */
ps->ddseq = htonl(n->dds);
length = sizeof(struct ospf_dbdes3_packet);
}
/* Prepare DBDES body */
if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M))
{
struct ospf_lsa_header *lsas;
struct top_hash_entry *en;
uint i = 0, lsa_max;
ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
en = (void *) s_get(&(n->dbsi));
while (i < lsa_max)
{
if (!SNODE_VALID(en))
{
n->myimms &= ~DBDES_M; /* Unset More bit */
break;
}
if ((en->lsa.age < LSA_MAXAGE) &&
lsa_flooding_allowed(en->lsa_type, en->domain, ifa))
{
lsa_hton_hdr(&(en->lsa), lsas + i);
i++;
}
en = SNODE_NEXT(en);
}
s_put(&(n->dbsi), SNODE en);
length += i * sizeof(struct ospf_lsa_header);
}
if (ospf_is_v2(p))
((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
else
((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;
pkt->length = htons(length);
}