FreeRTOS/Common/ethernet/lwIP_132/src/core/ipv4/ip_addr.c

   1 /**
   2  * @file
   3  * This is the IPv4 address tools implementation.
   4  *
   5  */
   6
   7 /*
   8  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification,
  12  * are permitted provided that the following conditions are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright notice,
  15  *    this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright notice,
  17  *    this list of conditions and the following disclaimer in the documentation
  18  *    and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  31  * OF SUCH DAMAGE.
  32  *
  33  * This file is part of the lwIP TCP/IP stack.
  34  *
  35  * Author: Adam Dunkels <adam@sics.se>
  36  *
  37  */
  38
  39 #include "lwip/opt.h"
  40 #include "lwip/ip_addr.h"
  41 #include "lwip/inet.h"
  42 #include "lwip/netif.h"
  43
  44 #define IP_ADDR_ANY_VALUE 0x00000000UL
  45 #define IP_ADDR_BROADCAST_VALUE 0xffffffffUL
  46
  47 /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
  48 const struct ip_addr ip_addr_any = { IP_ADDR_ANY_VALUE };
  49 const struct ip_addr ip_addr_broadcast = { IP_ADDR_BROADCAST_VALUE };
  50
  51 /**
  52  * Determine if an address is a broadcast address on a network interface
  53  *
  54  * @param addr address to be checked
  55  * @param netif the network interface against which the address is checked
  56  * @return returns non-zero if the address is a broadcast address
  57  */
  58 u8_t ip_addr_isbroadcast(struct ip_addr *addr, struct netif *netif)
  59 {
  60   u32_t addr2test;
  61
  62   addr2test = addr->addr;
  63   /* all ones (broadcast) or all zeroes (old skool broadcast) */
  64   if ((~addr2test == IP_ADDR_ANY_VALUE) ||
  65       (addr2test == IP_ADDR_ANY_VALUE))
  66     return 1;
  67   /* no broadcast support on this network interface? */
  68   else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0)
  69     /* the given address cannot be a broadcast address
  70      * nor can we check against any broadcast addresses */
  71     return 0;
  72   /* address matches network interface address exactly? => no broadcast */
  73   else if (addr2test == netif->ip_addr.addr)
  74     return 0;
  75   /*  on the same (sub) network... */
  76   else if (ip_addr_netcmp(addr, &(netif->ip_addr), &(netif->netmask))
  77          /* ...and host identifier bits are all ones? =>... */
  78           && ((addr2test & ~netif->netmask.addr) ==
  79            (IP_ADDR_BROADCAST_VALUE & ~netif->netmask.addr)))
  80     /* => network broadcast address */
  81     return 1;
  82   else
  83     return 0;
  84 }