/* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * 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 "opt.h"#include "lwip/ip_addr.h"#include "lwip/inet.h"#include "lwip/netif.h"/* 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 checked * @param netif the network interface against which the address is checked * @return returns non-zero if the address is a broadcast address * */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? */  else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0)    /* the given address cannot be a broadcast address     * nor can we check against any broadcast addresses */    return 0;  /* address matches network interface address exactly? => no broadcast */  else if (addr->addr == netif->ip_addr.addr)    return 0;  /*  on the same (sub) network... */  else if (ip_addr_netcmp(addr, &(netif->ip_addr), &(netif->netmask))         /* ...and host identifier bits are all ones? =>... */          && ((addr->addr & ~netif->netmask.addr) ==           (ip_addr_broadcast.addr & ~netif->netmask.addr)))    /* => network broadcast address */    return 1;  else    return 0;}