/*
 * Copyright (C) 2006 Mike McCauley
 * Copyright (C) 2010-2011 Andreas Steffen
 * HSR 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 "tnc_imv_manager.h"
#include "tnc_imv.h"
#include "tnc_imv_recommendations.h"

#include <tncifimv.h>
#include <tncif_names.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#include <daemon.h>
#include <utils/debug.h>
#include <threading/rwlock.h>
#include <threading/mutex.h>
#include <collections/linked_list.h>

typedef struct private_tnc_imv_manager_t private_tnc_imv_manager_t;

/**
 * Private data of an imv_manager_t object.
 */
struct private_tnc_imv_manager_t {

	/**
	 * Public members of imv_manager_t.
	 */
	imv_manager_t public;

	/**
	 * Linked list of IMVs
	 */
	linked_list_t *imvs;

	/**
	 * Lock for IMV list
	 */
	rwlock_t *lock;

	/**
	 * Next IMV ID to be assigned
	 */
	TNC_IMVID next_imv_id;

	/**
	 * Mutex to access next IMV ID
	 */
	mutex_t *id_mutex;

	/**
	 * Policy defining how to derive final recommendation from individual ones
	 */
	recommendation_policy_t policy;
};

METHOD(imv_manager_t, add, bool,
	private_tnc_imv_manager_t *this, imv_t *imv)
{
	TNC_Version version;
	TNC_IMVID imv_id;

	this->id_mutex->lock(this->id_mutex);
	imv_id = this->next_imv_id++;
	this->id_mutex->unlock(this->id_mutex);

	imv->set_id(imv, imv_id);
	if (imv->initialize(imv_id, TNC_IFIMV_VERSION_1,
						TNC_IFIMV_VERSION_1, &version) != TNC_RESULT_SUCCESS)
	{
		DBG1(DBG_TNC, "IMV \"%s\" failed to initialize", imv->get_name(imv));
		return FALSE;
	}
	this->lock->write_lock(this->lock);
	this->imvs->insert_last(this->imvs, imv);
	this->lock->unlock(this->lock);

	if (imv->provide_bind_function(imv->get_id(imv),
								   TNC_TNCS_BindFunction) != TNC_RESULT_SUCCESS)
	{
		if (imv->terminate)
		{
			imv->terminate(imv->get_id(imv));
		}
		DBG1(DBG_TNC, "IMV \"%s\" failed to obtain bind function",
			 imv->get_name(imv));
		this->lock->write_lock(this->lock);
		this->imvs->remove_last(this->imvs, (void**)&imv);
		this->lock->unlock(this->lock);
		return FALSE;
	}
	return TRUE;
}

METHOD(imv_manager_t, remove_, imv_t*,
	private_tnc_imv_manager_t *this, TNC_IMVID id)
{
	enumerator_t *enumerator;
	imv_t *imv, *removed_imv = NULL;

	this->lock->write_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (id == imv->get_id(imv))
		{
			this->imvs->remove_at(this->imvs, enumerator);
			removed_imv = imv;
			break;
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);

	return removed_imv;
}

METHOD(imv_manager_t, load, bool,
	private_tnc_imv_manager_t *this, char *name, char *path)
{
	imv_t *imv;

	imv = tnc_imv_create(name, path);
	if (!imv)
	{
		return FALSE;
	}
	if (!add(this, imv))
	{
		imv->destroy(imv);
		return FALSE;
	}
	DBG1(DBG_TNC, "IMV %u \"%s\" loaded from '%s'", imv->get_id(imv), name, path);
	return TRUE;
}

METHOD(imv_manager_t, load_from_functions, bool,
	private_tnc_imv_manager_t *this, char *name,
	TNC_IMV_InitializePointer initialize,
	TNC_IMV_NotifyConnectionChangePointer notify_connection_change,
	TNC_IMV_ReceiveMessagePointer receive_message,
	TNC_IMV_ReceiveMessageLongPointer receive_message_long,
	TNC_IMV_SolicitRecommendationPointer solicit_recommendation,
	TNC_IMV_BatchEndingPointer batch_ending,
	TNC_IMV_TerminatePointer terminate,
	TNC_IMV_ProvideBindFunctionPointer provide_bind_function)
{
	imv_t *imv;

	imv = tnc_imv_create_from_functions(name,
										initialize,notify_connection_change,
										receive_message, receive_message_long,
										solicit_recommendation, batch_ending,
										terminate, provide_bind_function);
	if (!imv)
	{
		return FALSE;
	}
	if (!add(this, imv))
	{
		imv->destroy(imv);
		return FALSE;
	}
	DBG1(DBG_TNC, "IMV %u \"%s\" loaded", imv->get_id(imv), name);
	return TRUE;
}

METHOD(imv_manager_t, is_registered, bool,
	private_tnc_imv_manager_t *this, TNC_IMVID id)
{
	enumerator_t *enumerator;
	imv_t *imv;
	bool found = FALSE;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (imv->has_id(imv, id))
		{
			found = TRUE;
			break;
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);

	return found;
}

METHOD(imv_manager_t, reserve_id, bool,
	private_tnc_imv_manager_t *this, TNC_IMVID id, TNC_UInt32 *new_id)
{
	enumerator_t *enumerator;
	imv_t *imv;
	bool found = FALSE;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (id == imv->get_id(imv))
		{
			found = TRUE;
			this->id_mutex->lock(this->id_mutex);
			*new_id = this->next_imv_id++;
			this->id_mutex->unlock(this->id_mutex);
			imv->add_id(imv, *new_id);
			DBG2(DBG_TNC, "additional ID %u reserved for IMV with primary ID %u",
						  *new_id, id);
			break;
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);

	return found;
}

METHOD(imv_manager_t, get_recommendation_policy, recommendation_policy_t,
	private_tnc_imv_manager_t *this)
{
	return this->policy;
}

METHOD(imv_manager_t, create_recommendations, recommendations_t*,
	private_tnc_imv_manager_t *this)
{
	return tnc_imv_recommendations_create(this->imvs);
}

METHOD(imv_manager_t, enforce_recommendation, bool,
	private_tnc_imv_manager_t *this, TNC_IMV_Action_Recommendation rec,
									 TNC_IMV_Evaluation_Result eval)
{
	char *group;
	identification_t *id;
	ike_sa_t *ike_sa;
	auth_cfg_t *auth;
	bool no_access = FALSE;

	DBG1(DBG_TNC, "final recommendation is '%N' and evaluation is '%N'",
		 TNC_IMV_Action_Recommendation_names, rec,
		 TNC_IMV_Evaluation_Result_names, eval);

	switch (rec)
	{
		case TNC_IMV_ACTION_RECOMMENDATION_ALLOW:
			group = "allow";
			break;
		case TNC_IMV_ACTION_RECOMMENDATION_ISOLATE:
			group = "isolate";
			break;
		case TNC_IMV_ACTION_RECOMMENDATION_NO_ACCESS:
		case TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION:
		default:
			group = "no access";
			no_access = TRUE;
			break;
	}

	ike_sa = charon->bus->get_sa(charon->bus);
	if (!ike_sa)
	{
		DBG1(DBG_TNC, "policy enforcement point did not find IKE_SA");
		return FALSE;
	}

	id = ike_sa->get_other_id(ike_sa);
	DBG0(DBG_TNC, "policy enforced on peer '%Y' is '%s'", id, group);

	if (no_access)
	{
		return FALSE;
	}
	else
	{
		auth = ike_sa->get_auth_cfg(ike_sa, FALSE);
		id = identification_create_from_string(group);
		auth->add(auth, AUTH_RULE_GROUP, id);
		DBG1(DBG_TNC, "policy enforcement point added group membership '%s'",
			 group);
	}
	return TRUE;
}


METHOD(imv_manager_t, notify_connection_change, void,
	private_tnc_imv_manager_t *this, TNC_ConnectionID id,
									 TNC_ConnectionState state)
{
	enumerator_t *enumerator;
	imv_t *imv;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (imv->notify_connection_change)
		{
			imv->notify_connection_change(imv->get_id(imv), id, state);
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);
}

METHOD(imv_manager_t, set_message_types, TNC_Result,
	private_tnc_imv_manager_t *this, TNC_IMVID id,
									 TNC_MessageTypeList supported_types,
									 TNC_UInt32 type_count)
{
	enumerator_t *enumerator;
	imv_t *imv;
	TNC_Result result = TNC_RESULT_FATAL;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (id == imv->get_id(imv))
		{
			imv->set_message_types(imv, supported_types, type_count);
			result = TNC_RESULT_SUCCESS;
			break;
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);
	return result;
}

METHOD(imv_manager_t, set_message_types_long, TNC_Result,
	private_tnc_imv_manager_t *this, TNC_IMVID id,
									 TNC_VendorIDList supported_vids,
									 TNC_MessageSubtypeList supported_subtypes,
									 TNC_UInt32 type_count)
{
	enumerator_t *enumerator;
	imv_t *imv;
	TNC_Result result = TNC_RESULT_FATAL;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (id == imv->get_id(imv))
		{
			imv->set_message_types_long(imv, supported_vids, supported_subtypes,
										type_count);
			result = TNC_RESULT_SUCCESS;
			break;
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);
	return result;
}

METHOD(imv_manager_t, solicit_recommendation, void,
	private_tnc_imv_manager_t *this, TNC_ConnectionID id)
{
	enumerator_t *enumerator;
	imv_t *imv;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		imv->solicit_recommendation(imv->get_id(imv), id);
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);
}

METHOD(imv_manager_t, receive_message, void,
	private_tnc_imv_manager_t *this, TNC_ConnectionID connection_id,
									 bool excl,
									 TNC_BufferReference msg,
									 TNC_UInt32 msg_len,
									 TNC_VendorID msg_vid,
									 TNC_MessageSubtype msg_subtype,
									 TNC_UInt32 src_imc_id,
									 TNC_UInt32 dst_imv_id)
{
	bool type_supported = FALSE;
	TNC_MessageType	msg_type;
	TNC_UInt32 msg_flags;
	enumerator_t *enumerator;
	imv_t *imv;

	msg_type = (msg_vid << 8) | msg_subtype;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (imv->type_supported(imv, msg_vid, msg_subtype) &&
			(!excl || (excl && imv->has_id(imv, dst_imv_id))))
		{
			if (imv->receive_message_long && src_imc_id)
			{
				type_supported = TRUE;
				msg_flags = excl ? TNC_MESSAGE_FLAGS_EXCLUSIVE : 0;
				imv->receive_message_long(imv->get_id(imv), connection_id,
								msg_flags, msg, msg_len, msg_vid, msg_subtype,
								src_imc_id, dst_imv_id);

			}
			else if (imv->receive_message && msg_vid <= TNC_VENDORID_ANY &&
					 msg_subtype <= TNC_SUBTYPE_ANY)
			{
				type_supported = TRUE;
				msg_type = (msg_vid << 8) | msg_subtype;
				imv->receive_message(imv->get_id(imv), connection_id,
									 msg, msg_len, msg_type);
			}
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);

	if (!type_supported)
	{
		DBG2(DBG_TNC, "message type 0x%06x/0x%08x not supported by any IMV",
			 msg_vid, msg_subtype);
	}
}

METHOD(imv_manager_t, batch_ending, void,
	private_tnc_imv_manager_t *this, TNC_ConnectionID id)
{
	enumerator_t *enumerator;
	imv_t *imv;

	this->lock->read_lock(this->lock);
	enumerator = this->imvs->create_enumerator(this->imvs);
	while (enumerator->enumerate(enumerator, &imv))
	{
		if (imv->batch_ending)
		{
			imv->batch_ending(imv->get_id(imv), id);
		}
	}
	enumerator->destroy(enumerator);
	this->lock->unlock(this->lock);
}

METHOD(imv_manager_t, destroy, void,
	private_tnc_imv_manager_t *this)
{
	imv_t *imv;

	while (this->imvs->remove_last(this->imvs, (void**)&imv) == SUCCESS)
	{
		if (imv->terminate &&
			imv->terminate(imv->get_id(imv)) != TNC_RESULT_SUCCESS)
		{
			DBG1(DBG_TNC, "IMV \"%s\" not terminated successfully",
						   imv->get_name(imv));
		}
		imv->destroy(imv);
	}
	this->imvs->destroy(this->imvs);
	this->lock->destroy(this->lock);
	this->id_mutex->destroy(this->id_mutex);
	free(this);
}

/**
 * Described in header.
 */
imv_manager_t* tnc_imv_manager_create(void)
{
	private_tnc_imv_manager_t *this;
	recommendation_policy_t policy;

	INIT(this,
		.public = {
			.add = _add,
			.remove = _remove_, /* avoid name conflict with stdio.h */
			.load = _load,
			.load_from_functions = _load_from_functions,
			.is_registered = _is_registered,
			.reserve_id = _reserve_id,
			.get_recommendation_policy = _get_recommendation_policy,
			.create_recommendations = _create_recommendations,
			.enforce_recommendation = _enforce_recommendation,
			.notify_connection_change = _notify_connection_change,
			.set_message_types = _set_message_types,
			.set_message_types_long = _set_message_types_long,
			.solicit_recommendation = _solicit_recommendation,
			.receive_message = _receive_message,
			.batch_ending = _batch_ending,
			.destroy = _destroy,
		},
		.imvs = linked_list_create(),
		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
		.id_mutex = mutex_create(MUTEX_TYPE_DEFAULT),
		.next_imv_id = 1,
	);

	policy = enum_from_name(recommendation_policy_names,
				lib->settings->get_str(lib->settings,
					"%s.plugins.tnc-imv.recommendation_policy", "default",
					charon->name));
	this->policy = (policy != -1) ? policy : RECOMMENDATION_POLICY_DEFAULT;
	DBG1(DBG_TNC, "TNC recommendation policy is '%N'",
				   recommendation_policy_names, this->policy);

	return &this->public;
}