strongSwan

/*

 * Copyright (C) 2005-2009 Martin Willi

 * Copyright (C) 2005 Jan Hutter

 * Hochschule fuer Technik Rapperswil

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2 of the License, or (at your

 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * for more details.

 */

#include <stddef.h>

#include "configuration_attribute.h"

#include <encoding/payloads/encodings.h>

#include <library.h>

#include <daemon.h>

typedef struct private_configuration_attribute_t private_configuration_attribute_t;

/**

 * Private data of an configuration_attribute_t object.

 *

 */

struct private_configuration_attribute_t {

    /**

     * Public configuration_attribute_t interface.

     */

    configuration_attribute_t public;

    /**

     * Type of the attribute.

     */

    u_int16_t type;

    /**

     * Length of the attribute.

     */

    u_int16_t length;

    /**

     * Attribute value as chunk.

     */

    chunk_t value;

};

/**

 * Encoding rules to parse or generate a configuration attribute.

 *

 * The defined offsets are the positions in a object of type

 * private_configuration_attribute_t.

 */

encoding_rule_t configuration_attribute_encodings[] = {

    { RESERVED_BIT,                        0                                                    },

    /* type of the attribute as 15 bit unsigned integer */

    { ATTRIBUTE_TYPE,                    offsetof(private_configuration_attribute_t, type)    },

    /* Length of attribute value */

    { CONFIGURATION_ATTRIBUTE_LENGTH,    offsetof(private_configuration_attribute_t, length)    },

    /* Value of attribute if attribute format flag is zero */

    { CONFIGURATION_ATTRIBUTE_VALUE,    offsetof(private_configuration_attribute_t, value)    }

};

/*

                           1                   2                   3

       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

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      !R|         Attribute Type      !            Length             |

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      |                                                               |

      ~                             Value                             ~

      |                                                               |

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

*/

/**

 * Implementation of payload_t.verify.

 */

static status_t verify(private_configuration_attribute_t *this)

{

    bool failed = FALSE;

    if (this->length != this->value.len)

    {

        DBG1(DBG_ENC, "invalid attribute length");

        return FAILED;

    }

    switch (this->type)

    {

         case INTERNAL_IP4_ADDRESS:

         case INTERNAL_IP4_NETMASK:

         case INTERNAL_IP4_DNS:

         case INTERNAL_IP4_NBNS:

         case INTERNAL_ADDRESS_EXPIRY:

         case INTERNAL_IP4_DHCP:

            if (this->length != 0 && this->length != 4)

            {

                failed = TRUE;

            }

            break;

         case INTERNAL_IP4_SUBNET:

            if (this->length != 0 && this->length != 8)

            {

                failed = TRUE;

            }

            break;

         case INTERNAL_IP6_ADDRESS:

         case INTERNAL_IP6_SUBNET:

            if (this->length != 0 && this->length != 17)

            {

                failed = TRUE;

            }

            break;

         case INTERNAL_IP6_DNS:

         case INTERNAL_IP6_NBNS:

         case INTERNAL_IP6_DHCP:

            if (this->length != 0 && this->length != 16)

            {

                failed = TRUE;

            }

            break;

         case SUPPORTED_ATTRIBUTES:

            if (this->length % 2)

            {

                failed = TRUE;

            }

            break;

         case APPLICATION_VERSION:

            /* any length acceptable */

            break;

         default:

            DBG1(DBG_ENC, "unknown attribute type %N",

                 configuration_attribute_type_names, this->type);

            break;

    }

    if (failed)

    {

        DBG1(DBG_ENC, "invalid attribute length %d for %N",

             this->length, configuration_attribute_type_names, this->type);

        return FAILED;

    }

    return SUCCESS;

}

/**

 * Implementation of payload_t.get_encoding_rules.

 */

static void get_encoding_rules(private_configuration_attribute_t *this,

                               encoding_rule_t **rules, size_t *rule_count)

{

    *rules = configuration_attribute_encodings;

    *rule_count = sizeof(configuration_attribute_encodings) / sizeof(encoding_rule_t);

}

/**

 * Implementation of payload_t.get_type.

 */

static payload_type_t get_type(private_configuration_attribute_t *this)

{

    return CONFIGURATION_ATTRIBUTE;

}

/**

 * Implementation of payload_t.get_next_type.

 */

static payload_type_t get_next_type(private_configuration_attribute_t *this)

{

    return NO_PAYLOAD;

}

/**

 * Implementation of payload_t.set_next_type.

 */

static void set_next_type(private_configuration_attribute_t *this,

                          payload_type_t type)

{

}

/**

 * Implementation of configuration_attribute_t.get_length.

 */

static size_t get_length(private_configuration_attribute_t *this)

{

    return this->value.len + CONFIGURATION_ATTRIBUTE_HEADER_LENGTH;

}

/**

 * Implementation of configuration_attribute_t.get_type.

 */

static configuration_attribute_type_t get_configuration_attribute_type(

                                    private_configuration_attribute_t *this)

{

    return this->type;

}

/**

 * Implementation of configuration_attribute_t.get_value.

 */

static chunk_t get_value(private_configuration_attribute_t *this)

{

    return this->value;

}

/**

 * Implementation of configuration_attribute_t.destroy and payload_t.destroy.

 */

static void destroy(private_configuration_attribute_t *this)

{

    free(this->value.ptr);

    free(this);

}

/*

 * Described in header.

 */

configuration_attribute_t *configuration_attribute_create()

{

    private_configuration_attribute_t *this;

    this = malloc_thing(private_configuration_attribute_t);

    this->public.payload_interface.verify = (status_t(*)(payload_t *))verify;

    this->public.payload_interface.get_encoding_rules = (void(*)(payload_t *, encoding_rule_t **, size_t *) )get_encoding_rules;

    this->public.payload_interface.get_length = (size_t(*)(payload_t *))get_length;

    this->public.payload_interface.get_next_type = (payload_type_t(*)(payload_t *))get_next_type;

    this->public.payload_interface.set_next_type = (void(*)(payload_t *,payload_type_t))set_next_type;

    this->public.payload_interface.get_type = (payload_type_t(*)(payload_t *))get_type;

    this->public.payload_interface.destroy = (void(*)(payload_t*))destroy;

    this->public.get_value = (chunk_t(*)(configuration_attribute_t *))get_value;

    this->public.get_type = (configuration_attribute_type_t(*)(configuration_attribute_t *))get_configuration_attribute_type;

    this->public.destroy = (void (*)(configuration_attribute_t*))destroy;

    this->type = 0;

    this->value = chunk_empty;

    this->length = 0;

    return &this->public;

}

/*

 * Described in header.

 */

configuration_attribute_t *configuration_attribute_create_value(

                            configuration_attribute_type_t type, chunk_t value)

{

    private_configuration_attribute_t *this;

    this = (private_configuration_attribute_t*)configuration_attribute_create();

    this->type = ((u_int16_t)type) & 0x7FFF;

    this->value = chunk_clone(value);

    this->length = value.len;

    return &this->public;

}