src/libcharon/encoding/payloads/configuration_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 <stddef.h>
  19
  20 #include "configuration_attribute.h"
  21
  22 #include <encoding/payloads/encodings.h>
  23 #include <library.h>
  24 #include <daemon.h>
  25
  26 typedef struct private_configuration_attribute_t private_configuration_attribute_t;
  27
  28 /**
  29  * Private data of an configuration_attribute_t object.
  30  */
  31 struct private_configuration_attribute_t {
  32
  33         /**
  34          * Public configuration_attribute_t interface.
  35          */
  36         configuration_attribute_t public;
  37
  38         /**
  39          * Reserved bit
  40          */
  41         bool reserved;
  42
  43         /**
  44          * Type of the attribute.
  45          */
  46         u_int16_t type;
  47
  48         /**
  49          * Length of the attribute.
  50          */
  51         u_int16_t length;
  52
  53         /**
  54          * Attribute value as chunk.
  55          */
  56         chunk_t value;
  57 };
  58
  59 /**
  60  * Encoding rules to parse or generate a configuration attribute.
  61  *
  62  * The defined offsets are the positions in a object of type
  63  * private_configuration_attribute_t.
  64  */
  65 encoding_rule_t configuration_attribute_encodings[] = {
  66         /* 1 reserved bit */
  67         { RESERVED_BIT,                                         offsetof(private_configuration_attribute_t, reserved)},
  68         /* type of the attribute as 15 bit unsigned integer */
  69         { ATTRIBUTE_TYPE,                                       offsetof(private_configuration_attribute_t, type)       },
  70         /* Length of attribute value */
  71         { CONFIGURATION_ATTRIBUTE_LENGTH,       offsetof(private_configuration_attribute_t, length)     },
  72         /* Value of attribute if attribute format flag is zero */
  73         { CONFIGURATION_ATTRIBUTE_VALUE,        offsetof(private_configuration_attribute_t, value)      }
  74 };
  75
  76 /*
  77                            1                   2                   3
  78        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
  79       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  80       !R|         Attribute Type      !            Length             |
  81       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  82       |                                                               |
  83       ~                             Value                             ~
  84       |                                                               |
  85       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86 */
  87
  88 METHOD(payload_t, verify, status_t,
  89         private_configuration_attribute_t *this)
  90 {
  91         bool failed = FALSE;
  92
  93         if (this->length != this->value.len)
  94         {
  95                 DBG1(DBG_ENC, "invalid attribute length");
  96                 return FAILED;
  97         }
  98
  99         switch (this->type)
 100         {
 101                  case INTERNAL_IP4_ADDRESS:
 102                  case INTERNAL_IP4_NETMASK:
 103                  case INTERNAL_IP4_DNS:
 104                  case INTERNAL_IP4_NBNS:
 105                  case INTERNAL_ADDRESS_EXPIRY:
 106                  case INTERNAL_IP4_DHCP:
 107                         if (this->length != 0 && this->length != 4)
 108                         {
 109                                 failed = TRUE;
 110                         }
 111                         break;
 112                  case INTERNAL_IP4_SUBNET:
 113                         if (this->length != 0 && this->length != 8)
 114                         {
 115                                 failed = TRUE;
 116                         }
 117                         break;
 118                  case INTERNAL_IP6_ADDRESS:
 119                  case INTERNAL_IP6_SUBNET:
 120                         if (this->length != 0 && this->length != 17)
 121                         {
 122                                 failed = TRUE;
 123                         }
 124                         break;
 125                  case INTERNAL_IP6_DNS:
 126                  case INTERNAL_IP6_NBNS:
 127                  case INTERNAL_IP6_DHCP:
 128                         if (this->length != 0 && this->length != 16)
 129                         {
 130                                 failed = TRUE;
 131                         }
 132                         break;
 133                  case SUPPORTED_ATTRIBUTES:
 134                         if (this->length % 2)
 135                         {
 136                                 failed = TRUE;
 137                         }
 138                         break;
 139                  case APPLICATION_VERSION:
 140                         /* any length acceptable */
 141                         break;
 142                  default:
 143                         DBG1(DBG_ENC, "unknown attribute type %N",
 144                                  configuration_attribute_type_names, this->type);
 145                         break;
 146         }
 147
 148         if (failed)
 149         {
 150                 DBG1(DBG_ENC, "invalid attribute length %d for %N",
 151                          this->length, configuration_attribute_type_names, this->type);
 152                 return FAILED;
 153         }
 154         return SUCCESS;
 155 }
 156
 157 METHOD(payload_t, get_encoding_rules, void,
 158         private_configuration_attribute_t *this, encoding_rule_t **rules,
 159         size_t *rule_count)
 160 {
 161         *rules = configuration_attribute_encodings;
 162         *rule_count = countof(configuration_attribute_encodings);
 163 }
 164
 165 METHOD(payload_t, get_type, payload_type_t,
 166         private_configuration_attribute_t *this)
 167 {
 168         return CONFIGURATION_ATTRIBUTE;
 169 }
 170
 171 METHOD(payload_t, get_next_type, payload_type_t,
 172         private_configuration_attribute_t *this)
 173 {
 174         return NO_PAYLOAD;
 175 }
 176
 177 METHOD(payload_t, set_next_type, void,
 178         private_configuration_attribute_t *this, payload_type_t type)
 179 {
 180 }
 181
 182 METHOD(payload_t, get_length, size_t,
 183         private_configuration_attribute_t *this)
 184 {
 185         return this->value.len + CONFIGURATION_ATTRIBUTE_HEADER_LENGTH;
 186 }
 187
 188 METHOD(configuration_attribute_t, get_cattr_type, configuration_attribute_type_t,
 189         private_configuration_attribute_t *this)
 190 {
 191         return this->type;
 192 }
 193
 194 METHOD(configuration_attribute_t, get_value, chunk_t,
 195         private_configuration_attribute_t *this)
 196 {
 197         return this->value;
 198 }
 199
 200 METHOD2(payload_t, configuration_attribute_t, destroy, void,
 201         private_configuration_attribute_t *this)
 202 {
 203         free(this->value.ptr);
 204         free(this);
 205 }
 206
 207 /*
 208  * Described in header.
 209  */
 210 configuration_attribute_t *configuration_attribute_create()
 211 {
 212         private_configuration_attribute_t *this;
 213
 214         INIT(this,
 215                 .public = {
 216                         .payload_interface = {
 217                                 .verify = _verify,
 218                                 .get_encoding_rules = _get_encoding_rules,
 219                                 .get_length = _get_length,
 220                                 .get_next_type = _get_next_type,
 221                                 .set_next_type = _set_next_type,
 222                                 .get_type = _get_type,
 223                                 .destroy = _destroy,
 224                         },
 225                         .get_value = _get_value,
 226                         .get_type = _get_cattr_type,
 227                         .destroy = _destroy,
 228                 },
 229         );
 230         return &this->public;
 231 }
 232
 233 /*
 234  * Described in header.
 235  */
 236 configuration_attribute_t *configuration_attribute_create_value(
 237                                                         configuration_attribute_type_t type, chunk_t value)
 238 {
 239         private_configuration_attribute_t *this;
 240
 241         this = (private_configuration_attribute_t*)configuration_attribute_create();
 242         this->type = ((u_int16_t)type) & 0x7FFF;
 243         this->value = chunk_clone(value);
 244         this->length = value.len;
 245
 246         return &this->public;
 247 }
 248