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#include <string.h>
#include "dns.h"
static void iopause(iopoll_fd *x,unsigned int len,struct timeval *deadline,struct timeval *stamp)
{
int millisecs;
unsigned int i;
if (TV_LESS(deadline,stamp))
millisecs = 0;
else {
if (deadline->tv_sec - stamp->tv_sec > 1000)
millisecs = 1000000;
else
millisecs = (deadline->tv_sec - stamp->tv_sec) * 1000 + (deadline->tv_usec - stamp->tv_usec) / 1000;
millisecs += 20;
}
for (i = 0;i < len;++i)
x[i].revents = 0;
iopoll(x,len,millisecs);
}
/** Resolve a DNS query.
This is the base query handler of the DNS library. It takes a domain
name and query type, sends it to all configured nameservers, and
handles reading the response packet. Callers are responsible for
parsing the desired records out of the resulting packet.
*/
int dns_resolve(struct dns_transmit *tx,const char *q,uint16 qtype)
{
struct timeval stamp;
struct timeval deadline;
ipv4addr servers[DNS_MAX_IPS];
iopoll_fd x[1];
int r;
if (dns_resolvconfip(servers) == -1) return -1;
if (dns_transmit_start(tx,servers,1,q,qtype,0) == -1) return -1;
for (;;) {
gettimeofday(&stamp,0);
deadline = stamp;
deadline.tv_sec += 120;
dns_transmit_io(tx,x,&deadline);
iopause(x,1,&deadline,&stamp);
r = dns_transmit_get(tx,x,&stamp);
if (r == -1) return -1;
if (r == 1) return 0;
}
}
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