/*
 * Copyright (C) 2015 Tobias Brunner
 * Copyright (C) 2005-2006 Martin Willi
 * Copyright (C) 2005 Jan Hutter
 *
 * Copyright (C) secunet Security Networks AG
 *
 * 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 "unknown_payload.h"

typedef struct private_unknown_payload_t private_unknown_payload_t;

/**
 * Private data of an unknown_payload_t object.
 */
struct private_unknown_payload_t {

	/**
	 * Public unknown_payload_t interface.
	 */
	unknown_payload_t public;

	/**
	 * Type of this payload
	 */
	payload_type_t type;

	/**
	 * Next payload type.
	 */
	uint8_t next_payload;

	/**
	 * Critical flag.
	 */
	bool critical;

	/**
	 * Reserved bits
	 */
	bool reserved[7];

	/**
	 * Length of this payload.
	 */
	uint16_t payload_length;

	/**
	 * The contained data.
	 */
	chunk_t data;
};

/**
 * Encoding rules to parse an payload which is not further specified.
 *
 * The defined offsets are the positions in a object of type
 * private_unknown_payload_t.
 *
 */
static encoding_rule_t encodings[] = {
	/* 1 Byte next payload type, stored in the field next_payload */
	{ U_INT_8,			offsetof(private_unknown_payload_t, next_payload)	},
	/* the critical bit */
	{ FLAG,				offsetof(private_unknown_payload_t, critical)		},
	/* 7 Bit reserved bits */
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[0])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[1])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[2])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[3])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[4])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[5])	},
	{ RESERVED_BIT,		offsetof(private_unknown_payload_t, reserved[6])	},
	/* Length of the whole payload*/
	{ PAYLOAD_LENGTH,	offsetof(private_unknown_payload_t, payload_length)	},
	/* some unknown data bytes, length is defined in PAYLOAD_LENGTH */
	{ CHUNK_DATA,		offsetof(private_unknown_payload_t, data)			},
};

/*
                           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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ! Next Payload  !C!  RESERVED   !         Payload Length        !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       !                                                               !
       ~                       Data of any type                        ~
       !                                                               !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/

METHOD(payload_t, verify, status_t,
	private_unknown_payload_t *this)
{
	return SUCCESS;
}

METHOD(payload_t, get_encoding_rules, int,
	private_unknown_payload_t *this, encoding_rule_t **rules)
{
	*rules = encodings;
	return countof(encodings);
}

METHOD(payload_t, get_header_length, int,
	private_unknown_payload_t *this)
{
	return 4;
}

METHOD(payload_t, get_payload_type, payload_type_t,
	private_unknown_payload_t *this)
{
	return PL_UNKNOWN;
}

METHOD(unknown_payload_t, get_type, payload_type_t,
	private_unknown_payload_t *this)
{
	return this->type;
}

METHOD(payload_t, get_next_type, payload_type_t,
	private_unknown_payload_t *this)
{
	return this->next_payload;
}

METHOD(payload_t, set_next_type, void,
	private_unknown_payload_t *this,payload_type_t type)
{
	this->next_payload = type;
}

METHOD(payload_t, get_length, size_t,
	private_unknown_payload_t *this)
{
	return this->payload_length;
}

METHOD(unknown_payload_t, is_critical, bool,
	private_unknown_payload_t *this)
{
	return this->critical;
}

METHOD(unknown_payload_t, get_data, chunk_t,
	private_unknown_payload_t *this)
{
	return this->data;
}

METHOD2(payload_t, unknown_payload_t, destroy, void,
	private_unknown_payload_t *this)
{
	free(this->data.ptr);
	free(this);
}

/*
 * Described in header
 */
unknown_payload_t *unknown_payload_create(payload_type_t type)
{
	private_unknown_payload_t *this;

	INIT(this,
		.public = {
			.payload_interface = {
				.verify = _verify,
				.get_encoding_rules = _get_encoding_rules,
				.get_header_length = _get_header_length,
				.get_length = _get_length,
				.get_next_type = _get_next_type,
				.set_next_type = _set_next_type,
				.get_type = _get_payload_type,
				.destroy = _destroy,
			},
			.is_critical = _is_critical,
			.get_type = _get_type,
			.get_data = _get_data,
			.destroy = _destroy,
		},
		.next_payload = PL_NONE,
		.payload_length = get_header_length(this),
		.type = type,
	);

	return &this->public;
}


/*
 * Described in header
 */
unknown_payload_t *unknown_payload_create_data(payload_type_t type,
											   bool critical, chunk_t data)
{
	private_unknown_payload_t *this;

	this = (private_unknown_payload_t*)unknown_payload_create(type);
	this->data = data;
	this->critical = critical;
	this->payload_length = get_header_length(this) + data.len;

	return &this->public;
}
