plugins/wimax/wimax_tlv.c

   1 /* wimax_tlv.c
   2  * WiMax TLV handling functions
   3  *
   4  * Copyright (c) 2007 by Intel Corporation.
   5  *
   6  * Author: Lu Pan <lu.pan@intel.com>
   7  *
   8  * $Id$
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1999 Gerald Combs
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  27  */
  28
  29 /*************************************************************/
  30 /*   ----------------------- NOTE -------------------------  */
  31 /* There is an identical copy of this file, wimax_tlv.c, in  */
  32 /* both .../plugins/m2m and .../plugins/wimax.  If either    */
  33 /* one needs to be modified, please be sure to copy the file */
  34 /* to the sister directory and check it in there also.       */
  35 /* This prevents having to generate a complicated            */
  36 /* Makefile.nmake in .../plugins/m2m.                        */
  37 /*************************************************************/
  38
  39 #include "config.h"
  40
  41 #include "wimax_tlv.h"
  42
  43 /*************************************************************/
  44 /* init_tlv_info()                                           */
  45 /* retrive the tlv information from specified tvb and offset */
  46 /* parameter:                                                */
  47 /*   info - pointer of a tlv information data structure      */
  48 /* return:                                                   */
  49 /*   0-success                                               */
  50 /*   !=0-the invalid size of the TLV length (failed)         */
  51 /*************************************************************/
  52 gint init_tlv_info(tlv_info_t *info, tvbuff_t *tvb, gint offset)
  53 {
  54         guint tlv_len;
  55
  56         /* get TLV type */
  57         info->type = (guint8)tvb_get_guint8( tvb, offset );
  58         /* get TLV length */
  59         tlv_len = (guint)tvb_get_guint8( tvb, (offset + 1) );
  60         /* set the TLV value offset */
  61         info->value_offset = 2;
  62         /* adjust for multiple-byte TLV length */
  63         if((tlv_len & WIMAX_TLV_EXTENDED_LENGTH_MASK) != 0)
  64         {       /* multiple bytes TLV length */
  65                 info->length_type = 1;
  66                 /* get the size of the TLV length */
  67                 tlv_len = (tlv_len & WIMAX_TLV_LENGTH_MASK);
  68                 info->size_of_length = tlv_len;
  69                 /* update the TLV value offset */
  70                 info->value_offset += tlv_len;
  71                 switch (tlv_len)
  72                 {
  73                         case 0:
  74                                 info->length = 0;  /* no length */
  75                         break;
  76                         case 1:
  77                                 info->length = (gint32)tvb_get_guint8( tvb, (offset + 2) ); /* 8 bit */
  78                         break;
  79                         case 2:
  80                                 info->length = (gint32)tvb_get_ntohs( tvb, (offset + 2) ); /* 16 bit */
  81                         break;
  82                         case 3:
  83                                 info->length = (gint32)tvb_get_ntoh24( tvb, (offset + 2) ); /* 24 bit */
  84                         break;
  85                         case 4:
  86                                 info->length = (gint32)tvb_get_ntohl( tvb, (offset + 2) ); /* 32 bit */
  87                         break;
  88                         default:
  89                                 /* mark invalid tlv */
  90                                 info->valid = 0;
  91                                 /* failed, return the invalid size of the tlv length */
  92                                 return (gint)tlv_len;
  93                         break;
  94                 }
  95         }
  96         else    /* single byte length */
  97         {
  98                 info->length_type = 0;
  99                 info->size_of_length = 0;
 100                 info->length = (gint32)tlv_len;
 101         }
 102         /* mark valid tlv */
 103         info->valid = 1;
 104         /* success */
 105         return 0;
 106 }
 107
 108 /*************************************************************/
 109 /* get_tlv_type()                                            */
 110 /* get the tlv type of the specified tlv information         */
 111 /* parameter:                                                */
 112 /*   info - pointer of a tlv information data structure      */
 113 /* return:                                                   */
 114 /*   >=0 - TLV type                                           */
 115 /*   =-1 - invalid tlv info                                  */
 116 /*************************************************************/
 117 gint get_tlv_type(tlv_info_t *info)
 118 {
 119         if(info->valid)
 120                 return (gint)info->type;
 121         return -1;
 122 }
 123
 124 /**************************************************************/
 125 /* get_tlv_size_of_length()                                   */
 126 /* get the size of tlv length of the specified tlv information*/
 127 /* parameter:                                                 */
 128 /*   info - pointer of a tlv information data structure       */
 129 /* return:                                                    */
 130 /*   >=0 - the size of TLV length                              */
 131 /*   =-1 - invalid tlv info                                   */
 132 /**************************************************************/
 133 gint get_tlv_size_of_length(tlv_info_t *info)
 134 {
 135         if(info->valid)
 136                 return (gint)info->size_of_length;
 137         return -1;
 138 }
 139
 140 /*************************************************************/
 141 /* get_tlv_length()                                          */
 142 /* get the tlv length of the specified tlv information       */
 143 /* parameter:                                                */
 144 /*   info - pointer of a tlv information data structure      */
 145 /* return:                                                   */
 146 /*   >=0 - TLV length                                         */
 147 /*   =-1 - invalid tlv info                                  */
 148 /*************************************************************/
 149 gint32 get_tlv_length(tlv_info_t *info)
 150 {
 151         if(info->valid)
 152                 return (gint32)info->length;
 153         return -1;
 154 }
 155
 156 /*************************************************************/
 157 /* get_tlv_value_offset()                                    */
 158 /* get the tlv value offset of the specified tlv information */
 159 /* parameter:                                                */
 160 /*   info - pointer of a tlv information data structure      */
 161 /* return:                                                   */
 162 /*   >0 - TLV value offset in byte                           */
 163 /*   =-1 - invalid tlv info                                  */
 164 /*************************************************************/
 165 gint get_tlv_value_offset(tlv_info_t *info)
 166 {
 167         if(info->valid)
 168                 return (gint)info->value_offset;
 169         return -1;
 170 }
 171
 172 /*************************************************************/
 173 /* get_tlv_length_type()                                     */
 174 /* get the tlv length type of the specified tlv information  */
 175 /* parameter:                                                */
 176 /*   info - pointer of a tlv information data structure      */
 177 /* return:                                                   */
 178 /*   0 - single byte TLV length                              */
 179 /*   1 - multiple bytes TLV length                           */
 180 /*************************************************************/
 181 gint get_tlv_length_type(tlv_info_t *info)
 182 {
 183         if(info->valid)
 184                 return (gint)info->length_type;
 185         return -1;
 186 }