strongswan/Source/charon/payloads/ike_header.c

158 lines
4.4 KiB
C

/**
* @file ike_header.c
*
* @brief Declaration of the class ike_header_t.
*
* An object of this type represents an ike header and is used to
* generate and parse ike headers.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, Martin Willi
* 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.
*/
/* offsetof macro */
#include <stddef.h>
#include "ike_header.h"
#include "encodings.h"
#include "../utils/allocator.h"
/**
* Encoding rules to parse or generate a IKEv2-Header
*
* The defined offsets are the positions in a object of type
* ike_header_t.
*
*/
encoding_rule_t ike_header_encodings[] = {
/* 8 Byte SPI, stored in the field initiator_spi */
{ U_INT_64, offsetof(ike_header_t, initiator_spi) },
/* 8 Byte SPI, stored in the field responder_spi */
{ U_INT_64, offsetof(ike_header_t, responder_spi) },
/* 1 Byte next payload type, stored in the field next_payload */
{ U_INT_8, offsetof(ike_header_t, next_payload) },
/* 4 Bit major version, stored in the field maj_version */
{ U_INT_4, offsetof(ike_header_t, maj_version) },
/* 4 Bit minor version, stored in the field min_version */
{ U_INT_4, offsetof(ike_header_t, min_version) },
/* 8 Bit for the exchange type */
{ U_INT_8, offsetof(ike_header_t, exchange_type) },
/* 2 Bit reserved bits, nowhere stored */
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
/* 3 Bit flags, stored in the fields response, version and initiator */
{ FLAG, offsetof(ike_header_t, flags.response) },
{ FLAG, offsetof(ike_header_t, flags.version) },
{ FLAG, offsetof(ike_header_t, flags.initiator) },
/* 3 Bit reserved bits, nowhere stored */
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
/* 4 Byte message id, stored in the field message_id */
{ U_INT_32, offsetof(ike_header_t, message_id) },
/* 4 Byte length fied, stored in the field length */
{ HEADER_LENGTH, offsetof(ike_header_t, length) }
};
/**
* Implements payload_t's and ike_header_t's destroy function.
* See #payload_s.destroy or ike_header_s.destroy for description.
*/
static status_t destroy(ike_header_t *this)
{
allocator_free(this);
return SUCCESS;
}
/**
* Implements payload_t's get_encoding_rules function.
* See #payload_s.get_encoding_rules for description.
*/
static status_t get_encoding_rules(payload_t *this, encoding_rule_t **rules, size_t *rule_count)
{
*rules = ike_header_encodings;
*rule_count = sizeof(ike_header_encodings) / sizeof(encoding_rule_t);
return SUCCESS;
}
/**
* Implements payload_t's get_type function.
* See #payload_s.get_type for description.
*/
static payload_type_t get_type(payload_t *this)
{
return HEADER;
}
/**
* Implements payload_t's get_next_type function.
* See #payload_s.get_next_type for description.
*/
static payload_type_t get_next_type(payload_t *this)
{
return (((ike_header_t*)this)->next_payload);
}
/**
* Implements payload_t's get_length function.
* See #payload_s.get_length for description.
*/
static size_t get_length(payload_t *this)
{
return IKE_HEADER_LENGTH;
}
/*
* Described in header
*/
ike_header_t *ike_header_create()
{
ike_header_t *this = allocator_alloc_thing(ike_header_t);
if (this == NULL)
{
return NULL;
}
this->payload_interface.get_encoding_rules = get_encoding_rules;
this->payload_interface.get_length = get_length;
this->payload_interface.get_next_type = get_next_type;
this->payload_interface.get_type = get_type;
this->payload_interface.destroy = (status_t (*) (payload_t *))destroy;
this->destroy = destroy;
/* set default values of the fields */
this->initiator_spi = 0;
this->responder_spi = 0;
this->next_payload = 0;
this->maj_version = IKE_MAJOR_VERSION;
this->min_version = IKE_MINOR_VERSION;
this->exchange_type = NOT_SET;
this->flags.initiator = TRUE;
this->flags.version = HIGHER_VERSION_SUPPORTED_FLAG;
this->flags.response = FALSE;
this->message_id = 0;
this->length = IKE_HEADER_LENGTH;
return this;
}