4

我正在尝试获取 A、MX 和 NS A 服务器记录，如下所示：

#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 收到很多相同的，即相同的 A 记录。NS 记录也是如此。我究竟做错了什么？例子 ：

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.

请帮忙。

4

2 回答 2

5

在本次通话中：

  ns_parserr(&msg, ns_s_an, 0, &rr);

第三个参数是您要检索的记录的索引。所以在你的情况下应该是：

  ns_parserr(&msg, ns_s_an, i, &rr);

刚刚用那个小修复尝试了你的代码，它按预期工作：

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.
于 2013-03-18T12:28:58.410 回答
0

使用 Ubuntu 20.04 及更高版本，

 res_query(argv[1], ns_c_any, ns_t_mx, nsbuf, sizeof(nsbuf));

失败。请用 ns_c_in 替换 ns_c_any

 res_query(argv[1], ns_c_in, ns_t_mx, nsbuf, sizeof(nsbuf));
于 2021-08-22T20:26:58.517 回答