void process_lsr(void *packet,u_int32_t from,u_int32_t to,unsigned int size,struct ospf_interface *oiface) {
struct ospf_lsr *lsr;
struct ospf_lsa *lsa;
struct ospf_neighbor *nbr;
struct replay_nlist *tmp_item=NULL;
//find the neighbor who sent the packet
nbr=find_neighbor_by_ip(from);
// if nbr found
if(nbr) {
// if the found nbr is not on the interface that we received the packet from then ignore this packet
if(nbr->ospf_if != oiface) {
nbr = NULL;
}
}
// make sure packet exists, valid nbr found, and packet size is correct for LSR
if(packet && (size>=(sizeof(struct ospfhdr)+sizeof(struct ospf_lsr))) && nbr) {
// get the LSR portion of the packet
lsr = (struct ospf_lsr *)(packet+sizeof(struct ospfhdr));
// find the lsa the nbr is asking for
lsa = find_lsa(lsr->advert_rtr,lsr->lsa_id,ntohl(lsr->lsa_type));
// if lsa found and the nbr is supposed to be sending LSRs
if(lsa&&(nbr->state>=OSPF_NBRSTATE_EXSTART)) {
// create a one item nlist with lsa as the object and the lsa id as key
tmp_item = add_to_nlist(tmp_item,(void *)lsa,(unsigned long long)(lsa->header->id.s_addr));
// send the lsu
send_lsu(nbr,tmp_item,OSPF_LSU_NOTRETX);
// remove the nlist items (but not the lsa objects)
remove_all_from_nlist(tmp_item);
}
}
}
/*---------------------------------------------------------------------
* Method: pwospf_run_thread
*
* Main thread of pwospf subsystem.
*
*---------------------------------------------------------------------*/
static
void* pwospf_run_thread(void* arg)
{
struct sr_instance* sr = (struct sr_instance*)arg;
while(1)
{
/* -- PWOSPF subsystem functionality should start here! -- */
int i;
for(i = 0; i < OSPF_DEFAULT_LSUINT; i += OSPF_DEFAULT_HELLOINT)
{
send_HELLO(sr);
sleep(OSPF_DEFAULT_HELLOINT);
}
/*Send LSU updates*/
check_top_invalid(sr); /*Check for expired topo entries*/
send_lsu(sr);
}
} /* -- run_ospf_thread -- */
void process_lsu(void *packet,u_int32_t from,u_int32_t to,unsigned int size,struct ospf_interface *oiface) {
struct ospf_lsa *lsa;
struct lsa_header *lsahdr,*new_hdr,*need_hdr;
struct ospf_neighbor *nbr,*tmp_nbr;
struct replay_nlist *updated=NULL;
struct replay_list *tmp_item,*tmp_item2;
long long lsa_ptr=0;
int ignore=0,send=0,changed_need_list=0;
struct timeval now,orig;
struct ospf_interface *tmp_if;
// find the nbr who sent the packet and make sure their iface matches the packet iface
nbr=find_neighbor_by_ip(from);
if(nbr) {
if(nbr->ospf_if != oiface) {
nbr = NULL;
}
}
gettimeofday(&now,NULL);
// if nbr, interface and packet are valid
if(nbr&&oiface&&packet) {
//ignore packet if from nbr who's < exstart
if(nbr->state>=OSPF_NBRSTATE_EXSTART) {
//start with the first lsa hdr in the LSU
lsa_ptr = (long long)packet + sizeof(struct ospfhdr) + sizeof(struct ospf_lsu);
// while we haven't reached the end of the packet
while(lsa_ptr<((long long)packet+size)) {
// get the current lsa hdr
lsahdr = (struct lsa_header *)lsa_ptr;
// increment the lsahdr's age by the transmit delay
lsahdr->ls_age = htons(ntohs(lsahdr->ls_age) + (u_int16_t)(ospf0->transmit_delay));
// find an existing lsa for this hdr if one exists
lsa = find_lsa(lsahdr->adv_router.s_addr,lsahdr->id.s_addr,lsahdr->type);
// get the time the lsa was originated
orig.tv_sec = now.tv_sec - lsahdr->ls_age;
// if lsa was found and lsa in lsdb is within margin of lsa recieved in lsu then ignore it
if(lsa) {
if((lsa->tv_orig.tv_sec+REPLAY_LSA_AGE_MARGIN)>orig.tv_sec) {
ignore = 1;
// else remove the old lsa
} else {
//ensure proper removal out of any lists?
remove_lsa(lsa);
}
}
// if we're not ignoring the current lsu packet's lsa hdr then add it to the lsdb
if(!ignore) {
// malloc the new lsa
new_hdr = malloc(ntohs(lsahdr->length));
memset(new_hdr,0,ntohs(lsahdr->length));
// copy the packet's current lsa into the new system lsa
memcpy(new_hdr,lsahdr,ntohs(lsahdr->length));
// add this lsa to the lsdb
lsa = add_lsa(new_hdr);
// if LSA recording is on for this interface, then write the lsa to disk
if(oiface->iface->record) {
fwrite(new_hdr,ntohs(new_hdr->length),1,oiface->iface->record);
}
// if successfully added then add the new lsa to the updated list
if(lsa) {
updated = add_to_nlist(updated,(void *)lsa,new_hdr->id.s_addr);
}
// find the new hdr in the need list and remove it if found
tmp_item = nbr->lsa_need_list;
while(tmp_item) {
need_hdr = (struct lsa_header *)(tmp_item->object);
if(need_hdr) {
if((need_hdr->adv_router.s_addr==new_hdr->adv_router.s_addr)&&(need_hdr->id.s_addr==new_hdr->id.s_addr)&&(need_hdr->type==new_hdr->type)) {
changed_need_list = 1;
nbr->lsa_need_list = remove_from_list(nbr->lsa_need_list,tmp_item);
tmp_item = NULL;
}
}
if(tmp_item) {
tmp_item = tmp_item->next;
}
}
}
// move to next lsa
lsa_ptr = lsa_ptr + ntohs(lsahdr->length);
}
// ack the recieved lsu
send_lsack(nbr,updated);
if(changed_need_list) {
// remove the LSR retransmit
find_and_remove_event((void *)nbr,OSPF_EVENT_LSR_RETX);
// if anything is still needed then send a new, updated lsr
// otherwise move the nbr to FULL
if(nbr->lsa_need_list) {
send_lsr(nbr);
} else {
nbr->state = OSPF_NBRSTATE_FULL;
}
}
// for each active ospf interface
tmp_item = ospf0->iflist;
while(tmp_item) {
tmp_if = (struct ospf_interface *)(tmp_item->object);
if(tmp_if) {
// for each nbr in this iface
tmp_item2 = tmp_if->nbrlist;
send = 0;
while(tmp_item2) {
// get the current nbr from the list item
tmp_nbr = (struct ospf_neighbor *)(tmp_item2->object);
// if the nbr exists and is not the nbr who sent the lsu
if(tmp_nbr && (tmp_nbr != nbr)) {
// if the nbr is at a state to recieve LSAs
if(tmp_nbr->state>=OSPF_NBRSTATE_EXSTART) {
// then set the send flag
send = 1;
tmp_item2=NULL;
}
}
// move to the next nbr
if(tmp_item2) {
tmp_item2 = tmp_item2->next;
}
}
}
// if a valid target for the lsu was found on this iface then send it
if(send) {
send_lsu(tmp_nbr,updated,OSPF_LSU_NOTRETX);
}
tmp_item = tmp_item->next;
}
remove_all_from_nlist(updated);
}
}
}
