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;
}
根据请求收到很多相同的，即相同的 A 记录。与 NS 记录相同。我究竟做错了什么？ 示例:
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。
最佳答案
在这个调用中:
ns_parserr(&msg, ns_s_an, 0, &rr);
第三个参数是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);
刚刚尝试了您的代码并进行了较小的修复，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.
关于c - 如何查询服务器并获取 MX、A、NS 记录，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15476717/