#include "libc.h"
#include <resolv.h>
#include <string.h>
#include <time.h>

int __res_mkquery(int op, const char* dname, int class, int type, const unsigned char* data,
                  int datalen, const unsigned char* newrr, unsigned char* buf, int buflen) {
    int id, i, j;
    unsigned char q[280];
    struct timespec ts;
    size_t l = strnlen(dname, 255);
    int n;

    if (l && dname[l - 1] == '.')
        l--;
    n = 17 + l + !!l;
    if (l > 253 || buflen < n || op > 15u || class > 255u || type > 255u)
        return -1;

    /* Construct query template - ID will be filled later */
    memset(q, 0, n);
    q[2] = op * 8 + 1;
    q[5] = 1;
    memcpy((char*)q + 13, dname, l);
    for (i = 13; q[i]; i = j + 1) {
        for (j = i; q[j] && q[j] != '.'; j++)
            ;
        if (j - i - 1u > 62u)
            return -1;
        q[i - 1] = j - i;
    }
    q[i + 1] = type;
    q[i + 3] = class;

    /* Make a reasonably unpredictable id */
    clock_gettime(CLOCK_REALTIME, &ts);
    id = (ts.tv_nsec + ts.tv_nsec / 65536UL) & 0xffff;
    q[0] = id / 256;
    q[1] = id;

    memcpy(buf, q, n);
    return n;
}

weak_alias(__res_mkquery, res_mkquery);