1#include <string.h>
 2#include "lookup.h"
 3
 4int __dns_parse(const unsigned char *r, int rlen, int (*callback)(void *, int, const void *, int, const void *, int), void *ctx)
 5{
 6	int qdcount, ancount;
 7	const unsigned char *p;
 8	int len;
 9
10	if (rlen<12) return -1;
11	if ((r[3]&15)) return 0;
12	p = r+12;
13	qdcount = r[4]*256 + r[5];
14	ancount = r[6]*256 + r[7];
15	while (qdcount--) {
16		while (p-r < rlen && *p-1U < 127) p++;
17		if (p>r+rlen-6)
18			return -1;
19		p += 5 + !!*p;
20	}
21	while (ancount--) {
22		while (p-r < rlen && *p-1U < 127) p++;
23		if (p>r+rlen-12)
24			return -1;
25		p += 1 + !!*p;
26		len = p[8]*256 + p[9];
27		if (len+10 > r+rlen-p) return -1;
28		if (callback(ctx, p[1], p+10, len, r, rlen) < 0) return -1;
29		p += 10 + len;
30	}
31	return 0;
32}