1#include <resolv.h> 2#include "libc.h" 3 4int __dn_expand(const unsigned char *base, const unsigned char *end, const unsigned char *src, char *dest, int space) 5{ 6 const unsigned char *p = src; 7 char *dend, *dbegin = dest; 8 int len = -1, i, j; 9 if (p==end || space <= 0) return -1; 10 dend = dest + (space > 254 ? 254 : space); 11 /* detect reference loop using an iteration counter */ 12 for (i=0; i < end-base; i+=2) { 13 /* loop invariants: p<end, dest<dend */ 14 if (*p & 0xc0) { 15 if (p+1==end) return -1; 16 j = ((p[0] & 0x3f) << 8) | p[1]; 17 if (len < 0) len = p+2-src; 18 if (j >= end-base) return -1; 19 p = base+j; 20 } else if (*p) { 21 if (dest != dbegin) *dest++ = '.'; 22 j = *p++; 23 if (j >= end-p || j >= dend-dest) return -1; 24 while (j--) *dest++ = *p++; 25 } else { 26 *dest = 0; 27 if (len < 0) len = p+1-src; 28 return len; 29 } 30 } 31 return -1; 32} 33 34weak_alias(__dn_expand, dn_expand); 35