ws_pipe: don't check for negative number using DWORD.

[metze/wireshark/wip.git] / epan / addr_and_mask.c

diff --git a/epan/addr_and_mask.c b/epan/addr_and_mask.c
index 3dd2941034f57b82149030c7de6d204b87a6b52b..84c4b69e8144bb843ca0ed6431795e1d0ddf9987 100644 (file)
--- a/epan/addr_and_mask.c
+++ b/epan/addr_and_mask.c
@@ -2,44 +2,50 @@
  * Routines to fetch IPv4 and IPv6 addresses from a tvbuff and then mask
  * out bits other than those covered by a prefix length
  *
- * $Id$
- *
- * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@ethereal.com>
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
  * Copyright 1998 Gerald Combs
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "tvbuff.h"
+#include "ipv6.h"
 #include "addr_and_mask.h"
 
+guint32
+ip_get_subnet_mask(const guint32 mask_length)
+{
+       static const guint32 masks[33] = {
+               0x00000000,
+               0x80000000, 0xc0000000, 0xe0000000, 0xf0000000,
+               0xf8000000, 0xfc000000, 0xfe000000, 0xff000000,
+               0xff800000, 0xffc00000, 0xffe00000, 0xfff00000,
+               0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000,
+               0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000,
+               0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00,
+               0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0,
+               0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff,
+       };
+
+       g_assert(mask_length <= 32);
+
+       return masks[mask_length];
+}
+
 /*
  * These routines return the length of the address in bytes on success
  * and -1 if the prefix length is too long.
  */
 
 int
-ipv4_addr_and_mask(tvbuff_t *tvb, int offset, guint8 *addr, guint32 prefix_len)
+tvb_get_ipv4_addr_with_prefix_len(tvbuff_t *tvb, int offset, guint8 *addr,
+    guint32 prefix_len)
 {
        guint32 addr_len;
 
@@ -55,7 +61,7 @@ ipv4_addr_and_mask(tvbuff_t *tvb, int offset, guint8 *addr, guint32 prefix_len)
 }
 
 int
-ipv6_addr_and_mask(tvbuff_t *tvb, int offset, struct e_in6_addr *addr,
+tvb_get_ipv6_addr_with_prefix_len(tvbuff_t *tvb, int offset, ws_in6_addr *addr,
     guint32 prefix_len)
 {
        guint32 addr_len;
@@ -64,12 +70,25 @@ ipv6_addr_and_mask(tvbuff_t *tvb, int offset, struct e_in6_addr *addr,
                return -1;
 
        addr_len = (prefix_len + 7) / 8;
-       memset(addr->u6_addr.u6_addr8, 0, 16);
-       tvb_memcpy(tvb, addr->u6_addr.u6_addr8, offset, addr_len);
+       memset(addr->bytes, 0, 16);
+       tvb_memcpy(tvb, addr->bytes, offset, addr_len);
        if (prefix_len % 8) {
-               addr->u6_addr.u6_addr8[addr_len - 1] &=
+               addr->bytes[addr_len - 1] &=
                    ((0xff00 >> (prefix_len % 8)) & 0xff);
        }
 
        return addr_len;
 }
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */