lib/libatm/cache_key.c

   1 /*
   2  *
   3  * ===================================
   4  * HARP  |  Host ATM Research Platform
   5  * ===================================
   6  *
   7  *
   8  * This Host ATM Research Platform ("HARP") file (the "Software") is
   9  * made available by Network Computing Services, Inc. ("NetworkCS")
  10  * "AS IS".  NetworkCS does not provide maintenance, improvements or
  11  * support of any kind.
  12  *
  13  * NETWORKCS MAKES NO WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED,
  14  * INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
  15  * AND FITNESS FOR A PARTICULAR PURPOSE, AS TO ANY ELEMENT OF THE
  16  * SOFTWARE OR ANY SUPPORT PROVIDED IN CONNECTION WITH THIS SOFTWARE.
  17  * In no event shall NetworkCS be responsible for any damages, including
  18  * but not limited to consequential damages, arising from or relating to
  19  * any use of the Software or related support.
  20  *
  21  * Copyright 1994-1998 Network Computing Services, Inc.
  22  *
  23  * Copies of this Software may be made, however, the above copyright
  24  * notice must be reproduced on all copies.
  25  *
  26  * $FreeBSD: src/lib/libatm/cache_key.c,v 1.3.2.1 2001/09/28 16:52:10 dillon Exp $
  27  * $DragonFly: src/lib/libatm/cache_key.c,v 1.2 2003/06/17 04:26:41 dillon Exp $
  28  */
  29
  30 /*
  31  * User Space Library Functions
  32  * ----------------------------
  33  *
  34  * SCSP cache key computation
  35  *
  36  */
  37
  38 #include <sys/types.h>
  39 #include <sys/param.h>
  40 #include <sys/socket.h>
  41 #include <net/if.h>
  42 #include <netinet/in.h>
  43 #include <netatm/port.h>
  44 #include <netatm/atm.h>
  45 #include <netatm/atm_if.h>
  46 #include <netatm/atm_sap.h>
  47 #include <netatm/atm_sys.h>
  48 #include <netatm/atm_ioctl.h>
  49
  50 #include <md5.h>
  51 #include <string.h>
  52
  53 #include "libatm.h"
  54
  55 /*
  56  * Compute an SCSP cache key
  57  *
  58  * Arguments:
  59  *      ap      pointer to an Atm_addr with the ATM address
  60  *      ip      pointer to a struct in_addr with the IP address
  61  *      ol      the required length of the cache key
  62  *      op      pointer to receive cache key
  63  *
  64  * Returns:
  65  *      none
  66  *
  67  */
  68 void
  69 scsp_cache_key(ap, ip, ol, op)
  70         Atm_addr        *ap;
  71         struct in_addr  *ip;
  72         int             ol;
  73         char            *op;
  74 {
  75         int     i, len;
  76         char    buff[32], digest[16];
  77         MD5_CTX context;
  78
  79         /*
  80          * Initialize
  81          */
  82         UM_ZERO(buff, sizeof(buff));
  83
  84         /*
  85          * Copy the addresses into a buffer for MD5 computation
  86          */
  87         len = sizeof(struct in_addr) + ap->address_length;
  88         if (len > sizeof(buff))
  89                 len = sizeof(buff);
  90         UM_COPY(ip, buff, sizeof(struct in_addr));
  91         UM_COPY(ap->address, &buff[sizeof(struct in_addr)],
  92                         len - sizeof(struct in_addr));
  93
  94         /*
  95          * Compute the MD5 digest of the combined IP and ATM addresses
  96          */
  97         MD5Init(&context);
  98         MD5Update(&context, buff, len);
  99         MD5Final(digest, &context);
 100
 101         /*
 102          * Fold the 16-byte digest to the required length
 103          */
 104         UM_ZERO((caddr_t)op, ol);
 105         for (i = 0; i < 16; i++) {
 106                 op[i % ol] = op[i % ol] ^ digest[i];
 107         }
 108 }