2 * Routines to fetch IPv4 and IPv6 addresses from a tvbuff and then mask
3 * out bits other than those covered by a prefix length
7 * Wireshark - Network traffic analyzer
8 * By Gerald Combs <gerald@wireshark.org>
9 * Copyright 1998 Gerald Combs
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
34 #include "addr_and_mask.h"
37 * These routines return the length of the address in bytes on success
38 * and -1 if the prefix length is too long.
42 ipv4_addr_and_mask(tvbuff_t *tvb, int offset, guint8 *addr, guint32 prefix_len)
49 addr_len = (prefix_len + 7) / 8;
51 tvb_memcpy(tvb, addr, offset, addr_len);
53 addr[addr_len - 1] &= ((0xff00 >> (prefix_len % 8)) & 0xff);
58 ipv6_addr_and_mask(tvbuff_t *tvb, int offset, struct e_in6_addr *addr,
66 addr_len = (prefix_len + 7) / 8;
67 memset(addr->bytes, 0, 16);
68 tvb_memcpy(tvb, addr->bytes, offset, addr_len);
70 addr->bytes[addr_len - 1] &=
71 ((0xff00 >> (prefix_len % 8)) & 0xff);