1#include <resolv.h>
 2#include <string.h>
 3#include <time.h>
 4
 5int __res_mkquery(int op, const char *dname, int class, int type,
 6	const unsigned char *data, int datalen,
 7	const unsigned char *newrr, unsigned char *buf, int buflen)
 8{
 9	int id, i, j;
10	unsigned char q[280];
11	struct timespec ts;
12	size_t l = strnlen(dname, 255);
13	int n;
14
15	if (l && dname[l-1]=='.') l--;
16	if (l && dname[l-1]=='.') return -1;
17	n = 17+l+!!l;
18	if (l>253 || buflen<n || op>15u || class>255u || type>255u)
19		return -1;
20
21	/* Construct query template - ID will be filled later */
22	memset(q, 0, n);
23	q[2] = op*8 + 1;
24	q[3] = 32; /* AD */
25	q[5] = 1;
26	memcpy((char *)q+13, dname, l);
27	for (i=13; q[i]; i=j+1) {
28		for (j=i; q[j] && q[j] != '.'; j++);
29		if (j-i-1u > 62u) return -1;
30		q[i-1] = j-i;
31	}
32	q[i+1] = type;
33	q[i+3] = class;
34
35	/* Make a reasonably unpredictable id */
36	clock_gettime(CLOCK_REALTIME, &ts);
37	id = ts.tv_nsec + ts.tv_nsec/65536UL & 0xffff;
38	q[0] = id/256;
39	q[1] = id;
40
41	memcpy(buf, q, n);
42	return n;
43}
44
45weak_alias(__res_mkquery, res_mkquery);