| 1 | 606 | jeremybenn | /**
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         | 2 |  |  |  * @file
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         | 3 |  |  |  * This is the IPv4 address tools implementation.
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         | 4 |  |  |  *
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         | 5 |  |  |  */
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         | 6 |  |  |  
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         | 7 |  |  | /*
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         | 8 |  |  |  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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         | 9 |  |  |  * All rights reserved.
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         | 10 |  |  |  *
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         | 11 |  |  |  * Redistribution and use in source and binary forms, with or without modification,
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         | 12 |  |  |  * are permitted provided that the following conditions are met:
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         | 13 |  |  |  *
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         | 14 |  |  |  * 1. Redistributions of source code must retain the above copyright notice,
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         | 15 |  |  |  *    this list of conditions and the following disclaimer.
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         | 16 |  |  |  * 2. Redistributions in binary form must reproduce the above copyright notice,
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         | 17 |  |  |  *    this list of conditions and the following disclaimer in the documentation
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         | 18 |  |  |  *    and/or other materials provided with the distribution.
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         | 19 |  |  |  * 3. The name of the author may not be used to endorse or promote products
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         | 20 |  |  |  *    derived from this software without specific prior written permission.
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         | 21 |  |  |  *
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         | 22 |  |  |  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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         | 23 |  |  |  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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         | 24 |  |  |  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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         | 25 |  |  |  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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         | 26 |  |  |  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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         | 27 |  |  |  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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         | 28 |  |  |  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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         | 29 |  |  |  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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         | 30 |  |  |  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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         | 31 |  |  |  * OF SUCH DAMAGE.
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         | 32 |  |  |  *
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         | 33 |  |  |  * This file is part of the lwIP TCP/IP stack.
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         | 34 |  |  |  *
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         | 35 |  |  |  * Author: Adam Dunkels <adam@sics.se>
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         | 36 |  |  |  *
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         | 37 |  |  |  */
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         | 38 |  |  |  
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         | 39 |  |  | #include "lwip/opt.h"
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         | 40 |  |  | #include "lwip/ip_addr.h"
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         | 41 |  |  | #include "lwip/inet.h"
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         | 42 |  |  | #include "lwip/netif.h"
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         | 43 |  |  |  
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         | 44 |  |  | #define IP_ADDR_ANY_VALUE 0x00000000UL
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         | 45 |  |  | #define IP_ADDR_BROADCAST_VALUE 0xffffffffUL
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         | 46 |  |  |  
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         | 47 |  |  | /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
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         | 48 |  |  | const struct ip_addr ip_addr_any = { IP_ADDR_ANY_VALUE };
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         | 49 |  |  | const struct ip_addr ip_addr_broadcast = { IP_ADDR_BROADCAST_VALUE };
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         | 50 |  |  |  
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         | 51 |  |  | /**
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         | 52 |  |  |  * Determine if an address is a broadcast address on a network interface
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         | 53 |  |  |  *
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         | 54 |  |  |  * @param addr address to be checked
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         | 55 |  |  |  * @param netif the network interface against which the address is checked
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         | 56 |  |  |  * @return returns non-zero if the address is a broadcast address
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         | 57 |  |  |  */
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         | 58 |  |  | u8_t ip_addr_isbroadcast(struct ip_addr *addr, struct netif *netif)
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         | 59 |  |  | {
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         | 60 |  |  |   u32_t addr2test;
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         | 61 |  |  |  
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         | 62 |  |  |   addr2test = addr->addr;
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         | 63 |  |  |   /* all ones (broadcast) or all zeroes (old skool broadcast) */
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         | 64 |  |  |   if ((~addr2test == IP_ADDR_ANY_VALUE) ||
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         | 65 |  |  |       (addr2test == IP_ADDR_ANY_VALUE))
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         | 66 |  |  |     return 1;
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         | 67 |  |  |   /* no broadcast support on this network interface? */
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         | 68 |  |  |   else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0)
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         | 69 |  |  |     /* the given address cannot be a broadcast address
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         | 70 |  |  |      * nor can we check against any broadcast addresses */
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         | 71 |  |  |     return 0;
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         | 72 |  |  |   /* address matches network interface address exactly? => no broadcast */
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         | 73 |  |  |   else if (addr2test == netif->ip_addr.addr)
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         | 74 |  |  |     return 0;
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         | 75 |  |  |   /*  on the same (sub) network... */
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         | 76 |  |  |   else if (ip_addr_netcmp(addr, &(netif->ip_addr), &(netif->netmask))
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         | 77 |  |  |          /* ...and host identifier bits are all ones? =>... */
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         | 78 |  |  |           && ((addr2test & ~netif->netmask.addr) ==
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         | 79 |  |  |            (IP_ADDR_BROADCAST_VALUE & ~netif->netmask.addr)))
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         | 80 |  |  |     /* => network broadcast address */
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         | 81 |  |  |     return 1;
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         | 82 |  |  |   else
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         | 83 |  |  |     return 0;
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         | 84 |  |  | }
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