lwip/src/core/ipv4/ip_addr.c

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/*
* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
#include "lwip/ip_addr.h"
#include "lwip/inet.h"
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#include "lwip/netif.h"
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/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
const struct ip_addr ip_addr_any = { 0x00000000UL };
const struct ip_addr ip_addr_broadcast = { 0xffffffffUL };
/* Determine if an address is a broadcast address on a network interface
*
* @param addr address to be checkedk
* @param netif the network interface against which the address is checked
* @return returns non-zero if the address is a broadcast address
*
* @intern work in progress - meant to replace ip_addr.h macro
* as it does not support non-broadcast interfaces.
* see lwip-devel mailing list on 18-2-2004
*/
u8_t ip_addr_isbroadcast(struct ip_addr *addr, struct netif *netif)
{
/* all ones (broadcast) or all zeroes (old skool broadcast) */
if ((addr->addr == ip_addr_broadcast.addr) ||
(addr->addr == ip_addr_any.addr))
return 1;
/* no broadcast support on this network interface
* we cannot proceed matching against broadcast addresses */
else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0)
return 0;
/* address matches network interface address exactly? => no broadcast */
else if (addr->addr == netif->ip_addr.addr)
return 0;
/* host identifier bits are all ones? => network broadcast address */
else if ((addr->addr & ~netif->netmask.addr) ==
(ip_addr_broadcast.addr & ~netif->netmask.addr))
return 1;
else
return 0;
}