I'm trying to get the A, MX and NS A server record as follows:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <resolv.h>
#include <netdb.h>
#define N 4096
int main (int argc, char *argv[])
{
u_char nsbuf[N];
char dispbuf[N];
ns_msg msg;
ns_rr rr;
int i, l;
if (argc < 2) {
printf ("Usage: %s <domain>\n", argv[0]);
exit (1);
}
// HEADER
printf("Domain : %s\n", argv[1]);
// ------
// A RECORD
printf("A records : \n");
l = res_query(argv[1], ns_c_any, ns_t_a, nsbuf, sizeof(nsbuf));
if (l < 0)
{
perror(argv[1]);
}
ns_initparse(nsbuf, l, &msg);
l = ns_msg_count(msg, ns_s_an);
for (i = 0; i < l; i++)
{
ns_parserr(&msg, ns_s_an, 0, &rr);
ns_sprintrr(&msg, &rr, NULL, NULL, dispbuf, sizeof(dispbuf));
printf("\t%s \n", dispbuf);
}
//------------
// MX RECORD
printf("MX records : \n");
l = res_query(argv[1], ns_c_any, ns_t_mx, nsbuf, sizeof(nsbuf));
if (l < 0)
{
perror(argv[1]);
}
else
{
#ifdef USE_PQUERY
/* this will give lots of detailed info on the request and reply */
res_pquery(&_res, nsbuf, l, stdout);
#else
/* just grab the MX answer info */
ns_initparse(nsbuf, l, &msg);
l = ns_msg_count(msg, ns_s_an);
for (i = 0; i < l; i++)
{
ns_parserr(&msg, ns_s_an, i, &rr);
ns_sprintrr(&msg, &rr, NULL, NULL, dispbuf, sizeof(dispbuf));
printf ("\t%s\n", dispbuf);
}
#endif
}
// ---------
// NS RECORD
printf("NS records : \n");
l = res_query(argv[1], ns_c_any, ns_t_ns, nsbuf, sizeof(nsbuf));
if (l < 0)
{
perror(argv[1]);
}
ns_initparse(nsbuf, l, &msg);
l = ns_msg_count(msg, ns_s_an);
for (i = 0; i < l; i++)
{
ns_parserr(&msg, ns_s_an, 0, &rr);
ns_sprintrr(&msg, &rr, NULL, NULL, dispbuf, sizeof(dispbuf));
printf("\t%s \n", dispbuf);
}
// ---------
return 0;
}
On request receive a lot of the same, that is, the same A records. The same with the NS records. What am I doing wrong? Example :
Domain : mail.ru
A records :
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
mail.ru. 22S IN A 94.100.191.207
MX records :
mail.ru. 1m57s IN MX 10 mxs.mail.ru.
NS records :
mail.ru. 1m50s IN NS ns.mail.ru.
mail.ru. 1m50s IN NS ns.mail.ru.
mail.ru. 1m50s IN NS ns.mail.ru.
mail.ru. 1m50s IN NS ns.mail.ru.
mail.ru. 1m50s IN NS ns.mail.ru.
mail.ru. 1m50s IN NS ns.mail.ru.
Please help.
In this call:
ns_parserr(&msg, ns_s_an, 0, &rr);
The third argument is the index of the record you want to retrieve. So in your case it should be:
ns_parserr(&msg, ns_s_an, i, &rr);
Just tried your code with that minor fix, and it works as expected:
Domain : mail.ru
A records :
mail.ru. 5S IN A 94.100.191.248
mail.ru. 5S IN A 94.100.191.249
mail.ru. 5S IN A 94.100.191.250
mail.ru. 5S IN A 94.100.191.201
mail.ru. 5S IN A 94.100.191.202
mail.ru. 5S IN A 94.100.191.203
mail.ru. 5S IN A 94.100.191.204
mail.ru. 5S IN A 94.100.191.205
mail.ru. 5S IN A 94.100.191.206
mail.ru. 5S IN A 94.100.191.207
mail.ru. 5S IN A 94.100.191.208
mail.ru. 5S IN A 94.100.191.209
mail.ru. 5S IN A 94.100.191.210
mail.ru. 5S IN A 94.100.191.241
mail.ru. 5S IN A 94.100.191.242
mail.ru. 5S IN A 94.100.191.243
mail.ru. 5S IN A 94.100.191.244
mail.ru. 5S IN A 94.100.191.245
mail.ru. 5S IN A 94.100.191.246
mail.ru. 5S IN A 94.100.191.247
MX records :
mail.ru. 7m14s IN MX 10 mxs.mail.ru.
NS records :
mail.ru. 3m35s IN NS ns2.mail.ru.
mail.ru. 3m35s IN NS ns.mail.ru.
mail.ru. 3m35s IN NS ns4.mail.ru.
mail.ru. 3m35s IN NS ns5.mail.ru.
mail.ru. 3m35s IN NS ns1.mail.ru.
mail.ru. 3m35s IN NS ns3.mail.ru.