src/libcharon/encoding/payloads/transform_attribute.c

   1 /*
   2  * Copyright (C) 2005-2010 Martin Willi
   3  * Copyright (C) 2010 revosec AG
   4  * Copyright (C) 2005 Jan Hutter
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 #include <string.h>
  19 #include <stddef.h>
  20
  21 #include "transform_attribute.h"
  22
  23 #include <encoding/payloads/encodings.h>
  24 #include <library.h>
  25
  26 typedef struct private_transform_attribute_t private_transform_attribute_t;
  27
  28 /**
  29  * Private data of an transform_attribute_t object.
  30  */
  31 struct private_transform_attribute_t {
  32
  33         /**
  34          * Public transform_attribute_t interface.
  35          */
  36         transform_attribute_t public;
  37
  38         /**
  39          * Attribute Format Flag.
  40          *
  41          * - TRUE means value is stored in attribute_length_or_value
  42          * - FALSE means value is stored in attribute_value
  43          */
  44         bool attribute_format;
  45
  46         /**
  47          * Type of the attribute.
  48          */
  49         u_int16_t attribute_type;
  50
  51         /**
  52          * Attribute Length if attribute_format is 0, attribute Value otherwise.
  53          */
  54         u_int16_t attribute_length_or_value;
  55
  56         /**
  57          * Attribute value as chunk if attribute_format is 0 (FALSE).
  58          */
  59         chunk_t attribute_value;
  60 };
  61
  62
  63 ENUM_BEGIN(transform_attribute_type_name, ATTRIBUTE_UNDEFINED, ATTRIBUTE_UNDEFINED,
  64         "ATTRIBUTE_UNDEFINED");
  65 ENUM_NEXT(transform_attribute_type_name, KEY_LENGTH, KEY_LENGTH, ATTRIBUTE_UNDEFINED,
  66         "KEY_LENGTH");
  67 ENUM_END(transform_attribute_type_name, KEY_LENGTH);
  68
  69 /**
  70  * Encoding rules to parse or generate a Transform attribute.
  71  *
  72  * The defined offsets are the positions in a object of type
  73  * private_transform_attribute_t.
  74  */
  75 encoding_rule_t transform_attribute_encodings[] = {
  76         /* Flag defining the format of this payload */
  77         { ATTRIBUTE_FORMAT,                     offsetof(private_transform_attribute_t, attribute_format)                       },
  78         /* type of the attribute as 15 bit unsigned integer */
  79         { ATTRIBUTE_TYPE,                       offsetof(private_transform_attribute_t, attribute_type)                         },
  80         /* Length or value, depending on the attribute format flag */
  81         { ATTRIBUTE_LENGTH_OR_VALUE,offsetof(private_transform_attribute_t, attribute_length_or_value)  },
  82         /* Value of attribute if attribute format flag is zero */
  83         { ATTRIBUTE_VALUE,                      offsetof(private_transform_attribute_t, attribute_value)                        }
  84 };
  85
  86 /*
  87                           1                   2                   3
  88        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
  89       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  90       !A!       Attribute Type        !    AF=0  Attribute Length     !
  91       !F!                             !    AF=1  Attribute Value      !
  92       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93       !                   AF=0  Attribute Value                       !
  94       !                   AF=1  Not Transmitted                       !
  95       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  96 */
  97
  98 METHOD(payload_t, verify, status_t,
  99         private_transform_attribute_t *this)
 100 {
 101         return SUCCESS;
 102 }
 103
 104 METHOD(payload_t, get_encoding_rules, void,
 105         private_transform_attribute_t *this, encoding_rule_t **rules,
 106         size_t *rule_count)
 107 {
 108         *rules = transform_attribute_encodings;
 109         *rule_count = countof(transform_attribute_encodings);
 110 }
 111
 112 METHOD(payload_t, get_type, payload_type_t,
 113         private_transform_attribute_t *this)
 114 {
 115         return TRANSFORM_ATTRIBUTE;
 116 }
 117
 118 METHOD(payload_t, get_next_type, payload_type_t,
 119         private_transform_attribute_t *this)
 120 {
 121         return NO_PAYLOAD;
 122 }
 123
 124 METHOD(payload_t, set_next_type, void,
 125         private_transform_attribute_t *this, payload_type_t type)
 126 {
 127 }
 128
 129 METHOD(payload_t, get_length, size_t,
 130         private_transform_attribute_t *this)
 131 {
 132         if (this->attribute_format)
 133         {
 134                 return 4;
 135         }
 136         return this->attribute_length_or_value + 4;
 137 }
 138
 139 METHOD(transform_attribute_t, set_value_chunk, void,
 140         private_transform_attribute_t *this, chunk_t value)
 141 {
 142         chunk_free(&this->attribute_value);
 143
 144         if (value.len != 2)
 145         {
 146                 this->attribute_value = chunk_clone(value);
 147                 this->attribute_length_or_value = value.len;
 148                 this->attribute_format = FALSE;
 149         }
 150         else
 151         {
 152                 memcpy(&this->attribute_length_or_value, value.ptr, value.len);
 153         }
 154 }
 155
 156 METHOD(transform_attribute_t, set_value, void,
 157         private_transform_attribute_t *this, u_int16_t value)
 158 {
 159         chunk_free(&this->attribute_value);
 160         this->attribute_length_or_value = value;
 161         this->attribute_format = TRUE;
 162 }
 163
 164 METHOD(transform_attribute_t, get_value_chunk, chunk_t,
 165         private_transform_attribute_t *this)
 166 {
 167         if (this->attribute_format)
 168         {
 169                 return chunk_from_thing(this->attribute_length_or_value);
 170         }
 171         return this->attribute_value;
 172 }
 173
 174 METHOD(transform_attribute_t, get_value, u_int16_t,
 175         private_transform_attribute_t *this)
 176 {
 177         return this->attribute_length_or_value;
 178 }
 179
 180 METHOD(transform_attribute_t, set_attribute_type, void,
 181         private_transform_attribute_t *this, u_int16_t type)
 182 {
 183         this->attribute_type = type & 0x7FFF;
 184 }
 185
 186 METHOD(transform_attribute_t, get_attribute_type, u_int16_t,
 187         private_transform_attribute_t *this)
 188 {
 189         return this->attribute_type;
 190 }
 191
 192 METHOD(transform_attribute_t, clone_, transform_attribute_t*,
 193         private_transform_attribute_t *this)
 194 {
 195         private_transform_attribute_t *new_clone;
 196
 197         new_clone = (private_transform_attribute_t *)transform_attribute_create();
 198
 199         new_clone->attribute_format = this->attribute_format;
 200         new_clone->attribute_type = this->attribute_type;
 201         new_clone->attribute_length_or_value = this->attribute_length_or_value;
 202
 203         if (!new_clone->attribute_format)
 204         {
 205                 new_clone->attribute_value = chunk_clone(this->attribute_value);
 206         }
 207         return &new_clone->public;
 208 }
 209
 210 METHOD2(payload_t, transform_attribute_t, destroy, void,
 211         private_transform_attribute_t *this)
 212 {
 213         free(this->attribute_value.ptr);
 214         free(this);
 215 }
 216
 217 /*
 218  * Described in header.
 219  */
 220 transform_attribute_t *transform_attribute_create()
 221 {
 222         private_transform_attribute_t *this;
 223
 224         INIT(this,
 225                 .public = {
 226                         .payload_interface = {
 227                                 .verify = _verify,
 228                                 .get_encoding_rules = _get_encoding_rules,
 229                                 .get_length = _get_length,
 230                                 .get_next_type = _get_next_type,
 231                                 .set_next_type = _set_next_type,
 232                                 .get_type = _get_type,
 233                                 .destroy = _destroy,
 234                         },
 235                         .set_value_chunk = _set_value_chunk,
 236                         .set_value = _set_value,
 237                         .get_value_chunk = _get_value_chunk,
 238                         .get_value = _get_value,
 239                         .set_attribute_type = _set_attribute_type,
 240                         .get_attribute_type = _get_attribute_type,
 241                         .clone = _clone_,
 242                         .destroy = _destroy,
 243                 },
 244                 .attribute_format = TRUE,
 245         );
 246         return &this->public;
 247 }
 248
 249 /*
 250  * Described in header.
 251  */
 252 transform_attribute_t *transform_attribute_create_key_length(u_int16_t key_length)
 253 {
 254         transform_attribute_t *attribute = transform_attribute_create();
 255         attribute->set_attribute_type(attribute, KEY_LENGTH);
 256         attribute->set_value(attribute, key_length);
 257         return attribute;
 258 }