/**
 * @file sa_config.c
 * 
 * @brief Implementation of sa_config_t.
 * 
 */

/*
 * 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.
 */

#include "sa_config.h"

#include <utils/linked_list.h>
#include <utils/allocator.h>
#include <utils/identification.h>

typedef struct private_sa_config_t private_sa_config_t;

/**
 * Private data of an sa_config_t object
 */
struct private_sa_config_t {

	/**
	 * Public part
	 */
	sa_config_t public;
	
	/**
	 * id to use to identify us
	 */
	identification_t *my_id;
	
	/**
	 * allowed id for other
	 */
	identification_t *other_id;
	
	/**
	 * authentification method to use
	 */
	auth_method_t auth_method;
	
	/**
	 * list for all proposals
	 */
	linked_list_t *proposals;
	
	/**
	 * list for traffic selectors
	 */
	linked_list_t *ts;

	/**
	 * compare two proposals for equality
	 */
	bool (*proposal_equals) (private_sa_config_t *this, child_proposal_t *first, child_proposal_t *second);
};

/**
 * implements sa_config_t.get_my_id
 */
static identification_t *get_my_id(private_sa_config_t *this)
{
	return this->my_id;
}

/**
 * implements sa_config_t.get_other_id
 */
static identification_t *get_other_id(private_sa_config_t *this)
{
	return this->other_id;
}

/**
 * implements sa_config_t.get_auth_method
 */
static auth_method_t get_auth_method(private_sa_config_t *this)
{
	return this->auth_method;
}

/**
 * implements sa_config_t.get_traffic_selectors
 */
static size_t get_traffic_selectors(private_sa_config_t *this, traffic_selector_t ***traffic_selectors)
{
	iterator_t *iterator;
	traffic_selector_t *current_ts;
	int counter = 0;
	*traffic_selectors = allocator_alloc(sizeof(traffic_selector_t*) * this->ts->get_count(this->ts));
	
	/* copy all ts from the list in an array */
	iterator = this->ts->create_iterator(this->ts, TRUE);
	while (iterator->has_next(iterator))
	{
		iterator->current(iterator, (void**)&current_ts);
		*((*traffic_selectors) + counter) = current_ts->clone(current_ts);
		counter++;
	}
	iterator->destroy(iterator);
	return counter;	
}

/**
 * implements sa_config_t.select_traffic_selectors
 */
static size_t select_traffic_selectors(private_sa_config_t *this, traffic_selector_t **supplied, size_t count, traffic_selector_t ***selected)
{
	iterator_t *iterator;
	traffic_selector_t *current_ts;
	int i, counter = 0;
	*selected = allocator_alloc(sizeof(traffic_selector_t*) * this->ts->get_count(this->ts));
	
	/* iterate over all stored proposals */
	iterator = this->ts->create_iterator(this->ts, TRUE);
	while (iterator->has_next(iterator))
	{
		iterator->current(iterator, (void**)&current_ts);
		for (i = 0; i < count; i++)
		{
			traffic_selector_t *new_ts;
			/* compare it */
			new_ts = current_ts->get_subset(current_ts, supplied[i]);
			/* match ? */
			if (new_ts)
			{
				*((*selected) + counter) = new_ts;
				counter++;
			}
		}
	}
	iterator->destroy(iterator);
	
	/* free unused space */
	*selected = allocator_realloc(*selected, sizeof(traffic_selector_t) * counter);
	return counter;	
}

/**
 * implements sa_config_t.get_proposals
 */
static size_t get_proposals(private_sa_config_t *this, u_int8_t ah_spi[4], u_int8_t esp_spi[4], child_proposal_t **proposals)
{
	iterator_t *iterator;
	child_proposal_t *current_proposal;
	int counter = 0;
	*proposals = allocator_alloc(sizeof(child_proposal_t) * this->proposals->get_count(this->proposals));
	
	/* copy all proposals from the list in an array */
	iterator = this->proposals->create_iterator(this->proposals, TRUE);
	while (iterator->has_next(iterator))
	{
		child_proposal_t *new_proposal = (*proposals) + counter;
		iterator->current(iterator, (void**)&current_proposal);
		*new_proposal = *current_proposal;
		memcpy(new_proposal->ah.spi, ah_spi, 4);
		memcpy(new_proposal->ah.spi, esp_spi, 4);
		counter++;
	}
	iterator->destroy(iterator);
	return counter;	
}

/**
 * implements sa_config_t.select_proposal
 */
static child_proposal_t *select_proposal(private_sa_config_t *this, u_int8_t ah_spi[4], u_int8_t esp_spi[4], child_proposal_t *supplied, size_t count)
{
	iterator_t *iterator;
	child_proposal_t *current_proposal, *selected_proposal;
	int i;
	
	/* iterate over all stored proposals */
	iterator = this->proposals->create_iterator(this->proposals, TRUE);
	while (iterator->has_next(iterator))
	{
		iterator->current(iterator, (void**)&current_proposal);
		/* copy and break if a proposal matches */
		for (i = 0; i < count; i++)
		{
			if (this->proposal_equals(this, &(supplied[i]), current_proposal))
			{
				selected_proposal = allocator_alloc(sizeof(child_proposal_t));
				*selected_proposal = *current_proposal;
				memcpy(selected_proposal->ah.spi, ah_spi, 4);
				memcpy(selected_proposal->ah.spi, esp_spi, 4);
				iterator->destroy(iterator);
				return selected_proposal;
			}
		}
	}
	iterator->destroy(iterator);
	return NULL;
}


/**
 * implements private_sa_config_t.proposal_equals
 */
static bool proposal_equals(private_sa_config_t *this, child_proposal_t *first, child_proposal_t *second)
{
	bool equal = FALSE;
	
	if (first->ah.is_set && second->ah.is_set)
	{
		if ((first->ah.integrity_algorithm != second->ah.integrity_algorithm) ||
			(first->ah.integrity_algorithm_key_size != second->ah.integrity_algorithm_key_size) ||
			(first->ah.diffie_hellman_group != second->ah.diffie_hellman_group) ||
			(first->ah.extended_sequence_numbers != second->ah.extended_sequence_numbers))
		{
			return FALSE;
		}
		equal = TRUE;
	}
	if (first->esp.is_set && second->esp.is_set)
	{
		if ((first->esp.encryption_algorithm != second->esp.encryption_algorithm) ||
			(first->esp.encryption_algorithm_key_size != second->esp.encryption_algorithm_key_size) ||
			(first->esp.integrity_algorithm != second->esp.integrity_algorithm) ||
			(first->esp.integrity_algorithm_key_size != second->esp.integrity_algorithm_key_size) ||
			(first->esp.diffie_hellman_group != second->esp.diffie_hellman_group) ||
			(first->esp.extended_sequence_numbers != second->esp.extended_sequence_numbers))
		{
			return FALSE;
		}
		equal = TRUE;
	}
	return equal;
}

/**
 * implements sa_config_t.add_traffic_selector
 */
static void add_traffic_selector(private_sa_config_t *this, traffic_selector_t *traffic_selector)
{
	/* clone ts, and add*/
	
	this->ts->insert_last(this->ts, (void*)traffic_selector->clone(traffic_selector));
}

/**
 * implements sa_config_t.add_proposal
 */
static void add_proposal(private_sa_config_t *this, child_proposal_t *proposal)
{
	/* clone proposal, and add*/
	child_proposal_t *new_proposal = allocator_alloc_thing(child_proposal_t);
	*new_proposal = *proposal;
	this->proposals->insert_last(this->proposals, (void*)new_proposal);
}

/**
 * Implements sa_config_t.destroy.
 */
static status_t destroy(private_sa_config_t *this)
{	
	child_proposal_t *proposal;
	traffic_selector_t *traffic_selector;
	
	
	/* delete proposals */
	while(this->proposals->get_count(this->proposals) > 0)
	{
		this->proposals->remove_last(this->proposals, (void**)&proposal);
		allocator_free(proposal);
	}
	this->proposals->destroy(this->proposals);
	
	/* delete traffic selectors */
	while(this->ts->get_count(this->ts) > 0)
	{
		this->ts->remove_last(this->ts, (void**)&traffic_selector);
		traffic_selector->destroy(traffic_selector);
	}
	this->ts->destroy(this->ts);
	
	/* delete ids */
	this->my_id->destroy(this->my_id);
	this->other_id->destroy(this->other_id);
	
	allocator_free(this);
	return SUCCESS;
}

/*
 * Described in header-file
 */
sa_config_t *sa_config_create(id_type_t my_id_type, char *my_id, id_type_t other_id_type, char *other_id, auth_method_t auth_method)
{
	private_sa_config_t *this = allocator_alloc_thing(private_sa_config_t);

	/* public functions */
	this->public.get_my_id = (identification_t*(*)(sa_config_t*))get_my_id;
	this->public.get_other_id = (identification_t*(*)(sa_config_t*))get_other_id;
	this->public.get_auth_method = (auth_method_t(*)(sa_config_t*))get_auth_method;
	this->public.get_traffic_selectors = (size_t(*)(sa_config_t*,traffic_selector_t***))get_traffic_selectors;
	this->public.select_traffic_selectors = (size_t(*)(sa_config_t*,traffic_selector_t**,size_t,traffic_selector_t***))select_traffic_selectors;
	this->public.get_proposals = (size_t(*)(sa_config_t*,u_int8_t[4],u_int8_t[4],child_proposal_t**))get_proposals;
	this->public.select_proposal = (child_proposal_t*(*)(sa_config_t*,u_int8_t[4],u_int8_t[4],child_proposal_t*,size_t))select_proposal;
	this->public.add_traffic_selector = (void(*)(sa_config_t*,traffic_selector_t*))add_traffic_selector;
	this->public.add_proposal = (void(*)(sa_config_t*,child_proposal_t*))add_proposal;
	this->public.destroy = (void(*)(sa_config_t*))destroy;

	
	/* apply init values */
	this->my_id = identification_create_from_string(my_id_type, my_id);
	if (this->my_id == NULL)
	{
		allocator_free(this);
		return NULL;	
	}
	this->other_id = identification_create_from_string(other_id_type, other_id);
	if (this->my_id == NULL)
	{
		this->other_id->destroy(this->other_id);
		allocator_free(this);
		return NULL;	
	}
	
	/* init private members*/
	this->proposal_equals = proposal_equals;
	this->proposals = linked_list_create();
	this->ts = linked_list_create();

	return (&this->public);
}