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#include <resolv.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <sys/poll.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/nameser.h>
#include "dietfeatures.h"
extern void __dns_make_fd(void);
extern int __dns_fd;
#ifdef WANT_IPV6_DNS
extern void __dns_make_fd6(void);
extern int __dns_fd6;
#endif
extern void __dns_readstartfiles(void);
int res_query(const char *dname, int class, int type, unsigned char *answer, int anslen) {
unsigned char packet[512];
int size;
#ifndef WANT_IPV6_DNS
__dns_make_fd();
#endif
__dns_readstartfiles();
if ((size=res_mkquery(QUERY,dname,class,type,0,0,0,packet,512))<0) { h_errno=NO_RECOVERY; return -1; }
{
{
int i; /* current server */
int j; /* timeout count down */
struct pollfd duh;
struct timeval last,now;
#ifdef WANT_IPV6_DNS
int tmpfd; /* the warning gcc issues here is bogus */
#else
duh.fd=__dns_fd;
#endif
i=0;
duh.events=POLLIN;
last.tv_sec=0;
for (j=120; j>0; --j) {
gettimeofday(&now,0);
if (now.tv_sec-last.tv_sec>10) {
#ifdef WANT_IPV6_DNS
struct sockaddr* s=(struct sockaddr*)&(_res.nsaddr_list[i]);
if (s->sa_family==AF_INET6) {
__dns_make_fd6();
tmpfd=__dns_fd6;
} else {
__dns_make_fd();
tmpfd=__dns_fd;
}
duh.fd=tmpfd;
if (sendto(tmpfd,packet,size,0,s,sizeof(struct sockaddr_in6))==0)
gettimeofday(&last,0);
#else
if (sendto(__dns_fd,packet,size,0,(struct sockaddr*)&(_res.nsaddr_list[i]),sizeof(struct sockaddr))==0)
gettimeofday(&last,0);
#endif
last=now;
}
if (++i >= _res.nscount) i=0;
if (poll(&duh,1,1000) == 1) {
/* read and parse answer */
unsigned char inpkg[1500];
#ifdef WANT_IPV6_DNS
int len=read(tmpfd,inpkg,1500);
#else
int len=read(__dns_fd,inpkg,1500);
#endif
/* header, question, answer, authority, additional */
if (inpkg[0]!=packet[0] || inpkg[1]!=packet[1]) continue; /* wrong ID */
if ((inpkg[2]&0xf9) != (_res.options&RES_RECURSE?0x81:0x80)) continue; /* not answer */
if ((inpkg[3]&0x0f) != 0) { h_errno=HOST_NOT_FOUND; return -1; } /* error */
if (len>anslen) {
h_errno=NO_RECOVERY;
return -1;
}
memmove(answer,inpkg,len);
return len;
}
/*kaputt:*/
}
}
}
h_errno=NO_DATA;
return -1;
}
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