Source/charon/encoding/payloads/transform_attribute.c

   1 /**
   2  * @file transform_attribute.c
   3  *
   4  * @brief Implementation of transform_attribute_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 /* offsetof macro */
  24 #include <stddef.h>
  25
  26 #include "transform_attribute.h"
  27
  28 #include <encoding/payloads/encodings.h>
  29 #include <types.h>
  30 #include <utils/allocator.h>
  31
  32 typedef struct private_transform_attribute_t private_transform_attribute_t;
  33
  34 /**
  35  * Private data of an transform_attribute_t object.
  36  *
  37  */
  38 struct private_transform_attribute_t {
  39         /**
  40          * Public transform_attribute_t interface.
  41          */
  42         transform_attribute_t public;
  43
  44         /**
  45          * Attribute Format Flag.
  46          *
  47          * - TRUE means value is stored in attribute_length_or_value
  48          * - FALSE means value is stored in attribute_value
  49          */
  50         bool attribute_format;
  51
  52         /**
  53          * Type of the attribute.
  54          */
  55         u_int16_t attribute_type;
  56
  57         /**
  58          * Attribute Length if attribute_format is 0, attribute Value otherwise.
  59          */
  60         u_int16_t attribute_length_or_value;
  61
  62         /**
  63          * Attribute value as chunk if attribute_format is 0 (FALSE).
  64          */
  65         chunk_t attribute_value;
  66 };
  67
  68 /**
  69  * String mappings for transform_attribute_type_t.
  70  */
  71 mapping_t transform_attribute_type_m[] = {
  72         {ATTRIBUTE_UNDEFINED, "ATTRIBUTE_UNDEFINED"},
  73         {KEY_LENGTH, "KEY_LENGTH"},
  74         {MAPPING_END, NULL}
  75 };
  76
  77 /**
  78  * Encoding rules to parse or generate a Transform attribute.
  79  *
  80  * The defined offsets are the positions in a object of type
  81  * private_transform_attribute_t.
  82  *
  83  */
  84 encoding_rule_t transform_attribute_encodings[] = {
  85         /* Flag defining the format of this payload */
  86         { ATTRIBUTE_FORMAT,                     offsetof(private_transform_attribute_t, attribute_format)                       },
  87         /* type of the attribute as 15 bit unsigned integer */
  88         { ATTRIBUTE_TYPE,                       offsetof(private_transform_attribute_t, attribute_type)                         },
  89         /* Length or value, depending on the attribute format flag */
  90         { ATTRIBUTE_LENGTH_OR_VALUE,    offsetof(private_transform_attribute_t, attribute_length_or_value)      },
  91         /* Value of attribute if attribute format flag is zero */
  92         { ATTRIBUTE_VALUE,                      offsetof(private_transform_attribute_t, attribute_value)                        }
  93 };
  94
  95 /*
  96                           1                   2                   3
  97        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  98       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  99       !A!       Attribute Type        !    AF=0  Attribute Length     !
 100       !F!                             !    AF=1  Attribute Value      !
 101       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 102       !                   AF=0  Attribute Value                       !
 103       !                   AF=1  Not Transmitted                       !
 104       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 105 */
 106
 107 /**
 108  * Implementation of payload_t.verify.
 109  */
 110 static status_t verify(private_transform_attribute_t *this)
 111 {
 112         if (this->attribute_type != KEY_LENGTH)
 113         {
 114                 return FAILED;
 115         }
 116
 117         return SUCCESS;
 118 }
 119
 120 /**
 121  * Implementation of payload_t.get_encoding_rules.
 122  */
 123 static void get_encoding_rules(private_transform_attribute_t *this, encoding_rule_t **rules, size_t *rule_count)
 124 {
 125         *rules = transform_attribute_encodings;
 126         *rule_count = sizeof(transform_attribute_encodings) / sizeof(encoding_rule_t);
 127 }
 128
 129 /**
 130  * Implementation of payload_t.get_type.
 131  */
 132 static payload_type_t get_type(private_transform_attribute_t *this)
 133 {
 134         return TRANSFORM_ATTRIBUTE;
 135 }
 136
 137 /**
 138  * Implementation of payload_t.get_next_type.
 139  */
 140 static payload_type_t get_next_type(private_transform_attribute_t *this)
 141 {
 142         return (NO_PAYLOAD);
 143 }
 144
 145 /**
 146  * Implementation of payload_t.set_next_type.
 147  */
 148 static void set_next_type(private_transform_attribute_t *this,payload_type_t type)
 149 {
 150 }
 151
 152 /**
 153  * Implementation of transform_attribute_t.get_length.
 154  */
 155 static size_t get_length(private_transform_attribute_t *this)
 156 {
 157         if (this->attribute_format == TRUE)
 158         {
 159                 /*Attribute size is only 4 byte */
 160                 return 4;
 161         }
 162         return (this->attribute_length_or_value + 4);
 163 }
 164
 165 /**
 166  * Implementation of transform_attribute_t.set_value_chunk.
 167  */
 168 static void set_value_chunk(private_transform_attribute_t *this, chunk_t value)
 169 {
 170         if (this->attribute_value.ptr != NULL)
 171         {
 172                 /* free existing value */
 173                 allocator_free(this->attribute_value.ptr);
 174                 this->attribute_value.ptr = NULL;
 175                 this->attribute_value.len = 0;
 176
 177         }
 178
 179         if (value.len > 2)
 180         {
 181                 this->attribute_value.ptr = allocator_clone_bytes(value.ptr,value.len);
 182                 this->attribute_value.len = value.len;
 183                 this->attribute_length_or_value = value.len;
 184                 /* attribute has not a fixed length */
 185                 this->attribute_format = FALSE;
 186         }
 187         else
 188         {
 189                 memcpy(&(this->attribute_length_or_value),value.ptr,value.len);
 190         }
 191 }
 192
 193 /**
 194  * Implementation of transform_attribute_t.set_value.
 195  */
 196 static void set_value(private_transform_attribute_t *this, u_int16_t value)
 197 {
 198         if (this->attribute_value.ptr != NULL)
 199         {
 200                 /* free existing value */
 201                 allocator_free(this->attribute_value.ptr);
 202                 this->attribute_value.ptr = NULL;
 203                 this->attribute_value.len = 0;
 204
 205         }
 206         this->attribute_length_or_value = value;
 207 }
 208
 209 /**
 210  * Implementation of transform_attribute_t.get_value_chunk.
 211  */
 212 static chunk_t get_value_chunk (private_transform_attribute_t *this)
 213 {
 214         chunk_t value;
 215
 216         if (this->attribute_format == FALSE)
 217         {
 218                 value.ptr = this->attribute_value.ptr;
 219                 value.len = this->attribute_value.len;
 220         }
 221         else
 222         {
 223                 value.ptr = (void *) &(this->attribute_length_or_value);
 224                 value.len = 2;
 225         }
 226
 227         return value;
 228 }
 229
 230 /**
 231  * Implementation of transform_attribute_t.get_value.
 232  */
 233 static u_int16_t get_value (private_transform_attribute_t *this)
 234 {
 235         return this->attribute_length_or_value;
 236 }
 237
 238
 239 /**
 240  * Implementation of transform_attribute_t.set_attribute_type.
 241  */
 242 static void set_attribute_type (private_transform_attribute_t *this, u_int16_t type)
 243 {
 244         this->attribute_type = type & 0x7FFF;
 245 }
 246
 247 /**
 248  * Implementation of transform_attribute_t.get_attribute_type.
 249  */
 250 static u_int16_t get_attribute_type (private_transform_attribute_t *this)
 251 {
 252         return this->attribute_type;
 253 }
 254
 255 /**
 256  * Implementation of transform_attribute_t.clone.
 257  */
 258 static transform_attribute_t * clone(private_transform_attribute_t *this)
 259 {
 260         private_transform_attribute_t *new_clone;
 261
 262         new_clone = (private_transform_attribute_t *) transform_attribute_create();
 263
 264         new_clone->attribute_format = this->attribute_format;
 265         new_clone->attribute_type = this->attribute_type;
 266         new_clone->attribute_length_or_value = this->attribute_length_or_value;
 267
 268         if (!new_clone->attribute_format)
 269         {
 270                 new_clone->attribute_value.ptr = allocator_clone_bytes(this->attribute_value.ptr,this->attribute_value.len);
 271                 new_clone->attribute_value.len = this->attribute_value.len;
 272         }
 273
 274         return (transform_attribute_t *) new_clone;
 275 }
 276
 277 /**
 278  * Implementation of transform_attribute_t.destroy and payload_t.destroy.
 279  */
 280 static void destroy(private_transform_attribute_t *this)
 281 {
 282         if (this->attribute_value.ptr != NULL)
 283         {
 284                 allocator_free(this->attribute_value.ptr);
 285         }
 286         allocator_free(this);
 287 }
 288
 289 /*
 290  * Described in header.
 291  */
 292 transform_attribute_t *transform_attribute_create()
 293 {
 294         private_transform_attribute_t *this = allocator_alloc_thing(private_transform_attribute_t);
 295
 296         /* payload interface */
 297         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 298         this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 299         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 300         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 301         this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
 302         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 303         this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
 304
 305         /* public functions */
 306         this->public.set_value_chunk = (void (*) (transform_attribute_t *,chunk_t)) set_value_chunk;
 307         this->public.set_value = (void (*) (transform_attribute_t *,u_int16_t)) set_value;
 308         this->public.get_value_chunk = (chunk_t (*) (transform_attribute_t *)) get_value_chunk;
 309         this->public.get_value = (u_int16_t (*) (transform_attribute_t *)) get_value;
 310         this->public.set_attribute_type = (void (*) (transform_attribute_t *,u_int16_t type)) set_attribute_type;
 311         this->public.get_attribute_type = (u_int16_t (*) (transform_attribute_t *)) get_attribute_type;
 312         this->public.clone = (transform_attribute_t * (*) (transform_attribute_t *)) clone;
 313         this->public.destroy = (void (*) (transform_attribute_t *)) destroy;
 314
 315         /* set default values of the fields */
 316         this->attribute_format = TRUE;
 317         this->attribute_type = 0;
 318         this->attribute_length_or_value = 0;
 319         this->attribute_value.ptr = NULL;
 320         this->attribute_value.len = 0;
 321
 322         return (&(this->public));
 323 }
 324