int dns_main_loop()
{
struct timeval tv;
fd_set active_rfds;
int retval;
dns_request_t m;
dns_request_t *ptr, *next;
//int purge_time = config.purge_time / 60;
int purge_time = CACHE_CHECK_TIME / DNS_TICK_TIME; //(30sec) modified by CMC 8/4/2001
while( !dns_main_quit ){
/* set the one second time out */
tv.tv_sec = DNS_TICK_TIME; //modified by CMC 8/3/2001
tv.tv_usec = 0;
/* now copy the main rfds in the active one as it gets modified by select*/
active_rfds = rfds;
retval = select( FD_SETSIZE, &active_rfds, NULL, NULL, &tv );
if (retval){
/* data is now available */
dns_read_packet( dns_sock, &m );
dns_handle_request( &m );
}else{
/* select time out */
ptr = dns_request_list;
while( ptr ){
next = ptr->next;
ptr->time_pending++;
if( ptr->time_pending > DNS_TIMEOUT/DNS_TICK_TIME ){
/* CMC: ptr->time_pending= DNS_TIMEOUT ~ DNS_TIMEOUT+DNS_TICK_TIME */
debug("Request timed out\n");
/* send error back */
dns_construct_error_reply(ptr);
dns_write_packet( dns_sock, ptr->src_addr, ptr->src_port, ptr );
dns_request_list = dns_list_remove( dns_request_list, ptr );
}
ptr = next;
} /* while(ptr) */
/* purge cache */
purge_time--;
if( purge_time <= 0 ){ //modified by CMC 8/4/2001
cache_purge( config.purge_time );
//purge_time = config.purge_time / 60;
purge_time = CACHE_CHECK_TIME / DNS_TICK_TIME; //(30sec) modified by CMC 8/3/2001
}
} /* if (retval) */
}
return 0;
}
int dns_main_loop()
{
struct timeval tv;
fd_set active_rfds;
int retval;
dns_request_t m;
dns_request_t *ptr, *next;
int purge_time = config.purge_time / 60;
int next_server_index = 0;
struct in_addr in;
while( !dns_main_quit ){
/* set the one second time out */
tv.tv_sec = 1;
tv.tv_usec = 0;
/* now copy the main rfds in the active one as it gets modified by select*/
active_rfds = rfds;
retval = select( FD_SETSIZE, &active_rfds, NULL, NULL, &tv );
if (retval){
/* data is now available */
dns_read_packet( dns_sock, &m );
m.time_pending = 0;
dns_handle_request( &m );
}else{
/* select time out */
ptr = dns_request_list;
while( ptr ){
next = ptr->next;
/* Resend query to a new nameserver if response
* has not been received from the current nameserver */
ptr->time_pending++;
if( ptr->time_pending > DNS_TIMEOUT ){
debug("Request timed out\n");
/* send error back */
dns_construct_error_reply(ptr);
dns_write_packet( dns_sock, ptr->src_addr, ptr->src_port, ptr );
dns_request_list = dns_list_remove( dns_request_list, ptr );
}
if( ( ptr->time_pending % DNS_SERVER_TIMEOUT == 0) &&
( ptr->time_pending < DNS_TIMEOUT) )
{
/* Send a request to the next nameserver */
next_server_index = ptr->time_pending/DNS_SERVER_TIMEOUT;
/* If already the maximum number of supported servers have
been tried out then remove the request from the list and
send a response back */
if(next_server_index >= MAX_NAME_SERVER ||
(config.name_server[next_server_index] == NULL ))
{
/* send error back */
debug("All Servers Tried: No Response\n");
dns_construct_error_reply(ptr);
dns_write_packet( dns_sock, ptr->src_addr, ptr->src_port, ptr );
dns_request_list = dns_list_remove( dns_request_list, ptr );
debug("Sent a DNS error message to Client \n");
}
else
{
/* Create the new server IP address and relay the query untouched */
inet_aton( config.name_server[next_server_index], &in );
/*!!!*/
debug("Didn't get a response from last server\n");
debug("Sending a new request to %s\n", config.name_server[next_server_index]);
/* Send the new request to the next name server */
dns_write_packet( dns_sock, in, PORT, ptr );
}
}
ptr = next;
} /* while(ptr) */
/* purge cache */
purge_time--;
if( !purge_time ){
cache_purge( config.purge_time );
purge_time = config.purge_time / 60;
}
} /* if (retval) */
}
return 0;
}
