1#include <resolv.h>
 2
 3int __dn_expand(const unsigned char *base, const unsigned char *end, const unsigned char *src, char *dest, int space)
 4{
 5	const unsigned char *p = src;
 6	char *dend, *dbegin = dest;
 7	int len = -1, i, j;
 8	if (p==end || space <= 0) return -1;
 9	dend = dest + (space > 254 ? 254 : space);
10	/* detect reference loop using an iteration counter */
11	for (i=0; i < end-base; i+=2) {
12		/* loop invariants: p<end, dest<dend */
13		if (*p & 0xc0) {
14			if (p+1==end) return -1;
15			j = ((p[0] & 0x3f) << 8) | p[1];
16			if (len < 0) len = p+2-src;
17			if (j >= end-base) return -1;
18			p = base+j;
19		} else if (*p) {
20			if (dest != dbegin) *dest++ = '.';
21			j = *p++;
22			if (j >= end-p || j >= dend-dest) return -1;
23			while (j--) *dest++ = *p++;
24		} else {
25			*dest = 0;
26			if (len < 0) len = p+1-src;
27			return len;
28		}
29	}
30	return -1;
31}
32
33weak_alias(__dn_expand, dn_expand);