| 1 | #include <resolv.h> |
| 2 | |
| 3 | int __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 | |
| 33 | weak_alias(__dn_expand, dn_expand); |