sbin/dhclient/inet.c

   1 /*      $OpenBSD: inet.c,v 1.7 2004/05/04 21:48:16 deraadt Exp $        */
   2 /*      $DragonFly: src/sbin/dhclient/inet.c,v 1.1 2008/08/30 16:07:58 hasso Exp $      */
   3
   4 /*
   5  * Subroutines to manipulate internet addresses in a safely portable
   6  * way...
   7  */
   8
   9 /*
  10  * Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  *
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of The Internet Software Consortium nor the names
  22  *    of its contributors may be used to endorse or promote products derived
  23  *    from this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  26  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  27  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  28  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  29  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  30  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  31  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  32  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  33  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  34  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  35  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  36  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  * This software has been written for the Internet Software Consortium
  40  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  41  * Enterprises.  To learn more about the Internet Software Consortium,
  42  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  43  * Enterprises, see ``http://www.vix.com''.
  44  */
  45
  46 #include "dhcpd.h"
  47
  48 /*
  49  * Return just the network number of an internet address...
  50  */
  51 struct iaddr
  52 subnet_number(struct iaddr addr, struct iaddr mask)
  53 {
  54         struct iaddr rv;
  55         int i;
  56
  57         rv.len = 0;
  58
  59         /* Both addresses must have the same length... */
  60         if (addr.len != mask.len)
  61                 return (rv);
  62
  63         rv.len = addr.len;
  64         for (i = 0; i < rv.len; i++)
  65                 rv.iabuf[i] = addr.iabuf[i] & mask.iabuf[i];
  66         return (rv);
  67 }
  68
  69 /*
  70  * Given a subnet number and netmask, return the address on that subnet
  71  * for which the host portion of the address is all ones (the standard
  72  * broadcast address).
  73  */
  74 struct iaddr
  75 broadcast_addr(struct iaddr subnet, struct iaddr mask)
  76 {
  77         struct iaddr rv;
  78         int i;
  79
  80         if (subnet.len != mask.len) {
  81                 rv.len = 0;
  82                 return (rv);
  83         }
  84
  85         for (i = 0; i < subnet.len; i++)
  86                 rv.iabuf[i] = subnet.iabuf[i] | (~mask.iabuf[i] & 255);
  87         rv.len = subnet.len;
  88
  89         return (rv);
  90 }
  91
  92 int
  93 addr_eq(struct iaddr addr1, struct iaddr addr2)
  94 {
  95         if (addr1.len != addr2.len)
  96                 return (0);
  97         return (memcmp(addr1.iabuf, addr2.iabuf, addr1.len) == 0);
  98 }
  99
 100 char *
 101 piaddr(struct iaddr addr)
 102 {
 103         static char pbuf[32];
 104         struct in_addr a;
 105         char *s;
 106
 107         memcpy(&a, &(addr.iabuf), sizeof(struct in_addr));
 108
 109         if (addr.len == 0)
 110                 strlcpy(pbuf, "<null address>", sizeof(pbuf));
 111         else {
 112                 s = inet_ntoa(a);
 113                 if (s != NULL)
 114                         strlcpy(pbuf, s, sizeof(pbuf));
 115                 else
 116                         strlcpy(pbuf, "<invalid address>", sizeof(pbuf));
 117         }
 118         return (pbuf);
 119 }