plugins/epan/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  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1999 Gerald Combs
  11  *
  12  * SPDX-License-Identifier: GPL-2.0-or-later
  13  */
  14
  15 #include "config.h"
  16
  17 #include "wimax_tlv.h"
  18
  19 /**************************************************************/
  20 /* init_tlv_info()                                            */
  21 /* retrieve the tlv information from specified tvb and offset */
  22 /* parameter:                                                 */
  23 /*   info - pointer of a tlv information data structure       */
  24 /* return:                                                    */
  25 /*   0-success                                                */
  26 /*   !=0-the invalid size of the TLV length (failed)          */
  27 /**************************************************************/
  28 int init_tlv_info(tlv_info_t *info, tvbuff_t *tvb, int offset)
  29 {
  30         unsigned tlv_len;
  31
  32         /* get TLV type */
  33         info->type = (uint8_t)tvb_get_uint8( tvb, offset );
  34         /* get TLV length */
  35         tlv_len = (unsigned)tvb_get_uint8( tvb, (offset + 1) );
  36         /* set the TLV value offset */
  37         info->value_offset = 2;
  38         /* adjust for multiple-byte TLV length */
  39         if((tlv_len & WIMAX_TLV_EXTENDED_LENGTH_MASK) != 0)
  40         {       /* multiple bytes TLV length */
  41                 info->length_type = 1;
  42                 /* get the size of the TLV length */
  43                 tlv_len = (tlv_len & WIMAX_TLV_LENGTH_MASK);
  44                 info->size_of_length = tlv_len;
  45                 /* update the TLV value offset */
  46                 info->value_offset += tlv_len;
  47                 switch (tlv_len)
  48                 {
  49                         case 0:
  50                                 info->length = 0;  /* no length */
  51                         break;
  52                         case 1:
  53                                 info->length = (int32_t)tvb_get_uint8( tvb, (offset + 2) ); /* 8 bit */
  54                         break;
  55                         case 2:
  56                                 info->length = (int32_t)tvb_get_ntohs( tvb, (offset + 2) ); /* 16 bit */
  57                         break;
  58                         case 3:
  59                                 info->length = (int32_t)tvb_get_ntoh24( tvb, (offset + 2) ); /* 24 bit */
  60                         break;
  61                         case 4:
  62                                 info->length = (int32_t)tvb_get_ntohl( tvb, (offset + 2) ); /* 32 bit */
  63                         break;
  64                         default:
  65                                 /* mark invalid tlv */
  66                                 info->valid = 0;
  67                                 /* failed, return the invalid size of the tlv length */
  68                                 return (int)tlv_len;
  69                         break;
  70                 }
  71         }
  72         else    /* single byte length */
  73         {
  74                 info->length_type = 0;
  75                 info->size_of_length = 0;
  76                 info->length = (int32_t)tlv_len;
  77         }
  78         /* mark valid tlv */
  79         info->valid = 1;
  80         /* success */
  81         return 0;
  82 }
  83
  84 /*************************************************************/
  85 /* get_tlv_type()                                            */
  86 /* get the tlv type of the specified tlv information         */
  87 /* parameter:                                                */
  88 /*   info - pointer of a tlv information data structure      */
  89 /* return:                                                   */
  90 /*   >=0 - TLV type                                           */
  91 /*   =-1 - invalid tlv info                                  */
  92 /*************************************************************/
  93 int get_tlv_type(tlv_info_t *info)
  94 {
  95         if(info->valid)
  96                 return (int)info->type;
  97         return -1;
  98 }
  99
 100 /**************************************************************/
 101 /* get_tlv_size_of_length()                                   */
 102 /* get the size of tlv length of the specified tlv information*/
 103 /* parameter:                                                 */
 104 /*   info - pointer of a tlv information data structure       */
 105 /* return:                                                    */
 106 /*   >=0 - the size of TLV length                              */
 107 /*   =-1 - invalid tlv info                                   */
 108 /**************************************************************/
 109 int get_tlv_size_of_length(tlv_info_t *info)
 110 {
 111         if(info->valid)
 112                 return (int)info->size_of_length;
 113         return -1;
 114 }
 115
 116 /*************************************************************/
 117 /* get_tlv_length()                                          */
 118 /* get the tlv length of the specified tlv information       */
 119 /* parameter:                                                */
 120 /*   info - pointer of a tlv information data structure      */
 121 /* return:                                                   */
 122 /*   >=0 - TLV length                                         */
 123 /*   =-1 - invalid tlv info                                  */
 124 /*************************************************************/
 125 int32_t get_tlv_length(tlv_info_t *info)
 126 {
 127         if(info->valid)
 128                 return (int32_t)info->length;
 129         return -1;
 130 }
 131
 132 /*************************************************************/
 133 /* get_tlv_value_offset()                                    */
 134 /* get the tlv value offset of the specified tlv information */
 135 /* parameter:                                                */
 136 /*   info - pointer of a tlv information data structure      */
 137 /* return:                                                   */
 138 /*   >0 - TLV value offset in byte                           */
 139 /*   =-1 - invalid tlv info                                  */
 140 /*************************************************************/
 141 int get_tlv_value_offset(tlv_info_t *info)
 142 {
 143         if(info->valid)
 144                 return (int)info->value_offset;
 145         return -1;
 146 }
 147
 148 /*************************************************************/
 149 /* get_tlv_length_type()                                     */
 150 /* get the tlv length type of the specified tlv information  */
 151 /* parameter:                                                */
 152 /*   info - pointer of a tlv information data structure      */
 153 /* return:                                                   */
 154 /*   0 - single byte TLV length                              */
 155 /*   1 - multiple bytes TLV length                           */
 156 /*************************************************************/
 157 int get_tlv_length_type(tlv_info_t *info)
 158 {
 159         if(info->valid)
 160                 return (int)info->length_type;
 161         return -1;
 162 }
 163
 164 /*
 165  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 166  *
 167  * Local variables:
 168  * c-basic-offset: 8
 169  * tab-width: 8
 170  * indent-tabs-mode: t
 171  * End:
 172  *
 173  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 174  * :indentSize=8:tabSize=8:noTabs=false:
 175  */