Source/charon/payloads/transform_attribute.c

   1 /**
   2  * @file transform_attribute.c
   3  *
   4  * @brief Declaration of the class transform_attribute_t.
   5  *
   6  * An object of this type represents an IKEv2 TRANSFORM attribute.
   7  *
   8  */
   9
  10 /*
  11  * Copyright (C) 2005 Jan Hutter, Martin Willi
  12  * Hochschule fuer Technik Rapperswil
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the
  16  * Free Software Foundation; either version 2 of the License, or (at your
  17  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  18  *
  19  * This program is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  21  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  22  * for more details.
  23  */
  24
  25 /* offsetof macro */
  26 #include <stddef.h>
  27
  28 #include "transform_attribute.h"
  29
  30 #include "encodings.h"
  31 #include "../types.h"
  32 #include "../utils/allocator.h"
  33
  34 /**
  35  * Private data of an transform_attribute_t Object
  36  *
  37  */
  38 typedef struct private_transform_attribute_s private_transform_attribute_t;
  39
  40 struct private_transform_attribute_s {
  41         /**
  42          * public transform_attribute_t interface
  43          */
  44         transform_attribute_t public;
  45
  46         /**
  47          * Attribute Format Flag
  48          *
  49          * - TRUE means value is stored in attribute_length_or_value
  50          * - FALSE means value is stored in attribute_value
  51          */
  52         bool attribute_format;
  53
  54         /**
  55          * Type of the attribute
  56          */
  57         u_int16_t attribute_type;
  58
  59         /**
  60          * Attribute Length if attribute_format is 0, attribute Value otherwise
  61          */
  62         u_int16_t attribute_length_or_value;
  63
  64         /**
  65          * Attribute value as chunk if attribute_format is 0 (FALSE)
  66          */
  67         chunk_t attribute_value;
  68 };
  69
  70
  71
  72 /**
  73  * string mappings for transform_attribute_type_t
  74  */
  75 mapping_t transform_attribute_type_m[] = {
  76         {ATTRIBUTE_UNDEFINED, "ATTRIBUTE_UNDEFINED"},
  77         {KEY_LENGTH, "KEY_LENGTH"},
  78         {MAPPING_END, NULL}
  79 };
  80
  81 /**
  82  * Encoding rules to parse or generate a Transform attribute
  83  *
  84  * The defined offsets are the positions in a object of type
  85  * private_transform_attribute_t.
  86  *
  87  */
  88 encoding_rule_t transform_attribute_encodings[] = {
  89         /* Flag defining the format of this payload */
  90         { ATTRIBUTE_FORMAT,                     offsetof(private_transform_attribute_t, attribute_format)                       },
  91         /* type of the attribute as 15 bit unsigned integer */
  92         { ATTRIBUTE_TYPE,                       offsetof(private_transform_attribute_t, attribute_type)                         },
  93         /* Length or value, depending on the attribute format flag */
  94         { ATTRIBUTE_LENGTH_OR_VALUE,    offsetof(private_transform_attribute_t, attribute_length_or_value)      },
  95         /* Value of attribute if attribute format flag is zero */
  96         { ATTRIBUTE_VALUE,                      offsetof(private_transform_attribute_t, attribute_value)                        }
  97 };
  98
  99 /*
 100                           1                   2                   3
 101        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
 102       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 103       !A!       Attribute Type        !    AF=0  Attribute Length     !
 104       !F!                             !    AF=1  Attribute Value      !
 105       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106       !                   AF=0  Attribute Value                       !
 107       !                   AF=1  Not Transmitted                       !
 108       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 109 */
 110
 111 /**
 112  * Implements payload_t's verify function.
 113  * See #payload_s.verify for description.
 114  */
 115 static status_t verify(private_transform_attribute_t *this)
 116 {
 117         if (this->attribute_type != KEY_LENGTH)
 118         {
 119                 return FAILED;
 120         }
 121
 122         return SUCCESS;
 123 }
 124
 125 /**
 126  * Implements payload_t's and transform_attribute_t's destroy function.
 127  * See #payload_s.destroy or transform_attribute_s.destroy for description.
 128  */
 129 static status_t destroy(private_transform_attribute_t *this)
 130 {
 131         if (this->attribute_value.ptr != NULL)
 132         {
 133                 allocator_free(this->attribute_value.ptr);
 134         }
 135         allocator_free(this);
 136
 137         return SUCCESS;
 138 }
 139
 140 /**
 141  * Implements payload_t's get_encoding_rules function.
 142  * See #payload_s.get_encoding_rules for description.
 143  */
 144 static status_t get_encoding_rules(private_transform_attribute_t *this, encoding_rule_t **rules, size_t *rule_count)
 145 {
 146         *rules = transform_attribute_encodings;
 147         *rule_count = sizeof(transform_attribute_encodings) / sizeof(encoding_rule_t);
 148
 149         return SUCCESS;
 150 }
 151
 152 /**
 153  * Implements payload_t's get_type function.
 154  * See #payload_s.get_type for description.
 155  */
 156 static payload_type_t get_type(private_transform_attribute_t *this)
 157 {
 158         return TRANSFORM_ATTRIBUTE;
 159 }
 160
 161 /**
 162  * Implements payload_t's get_next_type function.
 163  * See #payload_s.get_next_type for description.
 164  */
 165 static payload_type_t get_next_type(private_transform_attribute_t *this)
 166 {
 167         return (NO_PAYLOAD);
 168 }
 169
 170 /**
 171  * Implements payload_t's set_next_type function.
 172  * See #payload_s.set_next_type for description.
 173  */
 174 static status_t set_next_type(private_transform_attribute_t *this,payload_type_t type)
 175 {
 176         return SUCCESS;
 177 }
 178
 179 /**
 180  * Implements payload_t's get_length function.
 181  * See #payload_s.get_length for description.
 182  */
 183 static size_t get_length(private_transform_attribute_t *this)
 184 {
 185         if (this->attribute_format == TRUE)
 186         {
 187                 /*Attribute size is only 4 byte */
 188                 return 4;
 189         }
 190         return (this->attribute_length_or_value + 4);
 191 }
 192 /**
 193  * Implements transform_attribute_t's set_value function.
 194  * See #transform_attribute_s.set_value for description.
 195  */
 196 static status_t set_value_chunk(private_transform_attribute_t *this, chunk_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
 207         if (value.len > 2)
 208         {
 209                 this->attribute_value.ptr = allocator_clone_bytes(value.ptr,value.len);
 210                 if (this->attribute_value.ptr == NULL)
 211                 {
 212                         return OUT_OF_RES;
 213                 }
 214                 this->attribute_value.len = value.len;
 215                 this->attribute_length_or_value = value.len;
 216                 /* attribute has not a fixed length */
 217                 this->attribute_format = FALSE;
 218         }
 219         else
 220         {
 221                 memcpy(&(this->attribute_length_or_value),value.ptr,value.len);
 222         }
 223         return SUCCESS;
 224 }
 225
 226 /**
 227  * Implements transform_attribute_t's set_value function.
 228  * See #transform_attribute_s.set_value for description.
 229  */
 230 static status_t set_value(private_transform_attribute_t *this, u_int16_t value)
 231 {
 232         if (this->attribute_value.ptr != NULL)
 233         {
 234                 /* free existing value */
 235                 allocator_free(this->attribute_value.ptr);
 236                 this->attribute_value.ptr = NULL;
 237                 this->attribute_value.len = 0;
 238
 239         }
 240         this->attribute_length_or_value = value;
 241         return SUCCESS;
 242 }
 243
 244 /**
 245  * Implements transform_attribute_t's get_value_chunk function.
 246  * See #transform_attribute_s.get_value_chunk for description.
 247  */
 248 static chunk_t get_value_chunk (private_transform_attribute_t *this)
 249 {
 250         chunk_t value;
 251
 252         if (this->attribute_format == FALSE)
 253         {
 254                 value.ptr = this->attribute_value.ptr;
 255                 value.len = this->attribute_value.len;
 256         }
 257         else
 258         {
 259                 value.ptr = (void *) &(this->attribute_length_or_value);
 260                 value.len = 2;
 261         }
 262
 263         return value;
 264 }
 265
 266 /**
 267  * Implements transform_attribute_t's get_value function.
 268  * See #transform_attribute_s.get_value for description.
 269  */
 270 static u_int16_t get_value (private_transform_attribute_t *this)
 271 {
 272         return this->attribute_length_or_value;
 273 }
 274
 275
 276 /**
 277  * Implements transform_attribute_t's set_attribute_type function.
 278  * See #transform_attribute_s.set_attribute_type for description.
 279  */
 280 static status_t set_attribute_type (private_transform_attribute_t *this, u_int16_t type)
 281 {
 282         this->attribute_type = type & 0x7FFF;
 283         return SUCCESS;
 284 }
 285
 286 /**
 287  * Implements transform_attribute_t's get_attribute_type function.
 288  * See #transform_attribute_s.get_attribute_type for description.
 289  */
 290 static u_int16_t get_attribute_type (private_transform_attribute_t *this)
 291 {
 292         return this->attribute_type;
 293 }
 294
 295 /*
 296  * Described in header
 297  */
 298 transform_attribute_t *transform_attribute_create()
 299 {
 300         private_transform_attribute_t *this = allocator_alloc_thing(private_transform_attribute_t);
 301         if (this == NULL)
 302         {
 303                 return NULL;
 304         }
 305
 306         /* payload interface */
 307         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 308         this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 309         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 310         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 311         this->public.payload_interface.set_next_type = (status_t (*) (payload_t *,payload_type_t)) set_next_type;
 312         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 313         this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
 314
 315         /* public functions */
 316         this->public.set_value_chunk = (status_t (*) (transform_attribute_t *,chunk_t)) set_value_chunk;
 317         this->public.set_value = (status_t (*) (transform_attribute_t *,u_int16_t)) set_value;
 318         this->public.get_value_chunk = (chunk_t (*) (transform_attribute_t *)) get_value_chunk;
 319         this->public.get_value = (u_int16_t (*) (transform_attribute_t *)) get_value;
 320         this->public.set_attribute_type = (status_t (*) (transform_attribute_t *,u_int16_t type)) set_attribute_type;
 321         this->public.get_attribute_type = (u_int16_t (*) (transform_attribute_t *)) get_attribute_type;
 322         this->public.destroy = (status_t (*) (transform_attribute_t *)) destroy;
 323
 324         /* set default values of the fields */
 325         this->attribute_format = TRUE;
 326         this->attribute_type = 0;
 327         this->attribute_length_or_value = 0;
 328         this->attribute_value.ptr = NULL;
 329         this->attribute_value.len = 0;
 330
 331         return (&(this->public));
 332 }
 333