/*
 * Copyright (c) 2008 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup icmp
 *  @{
 */

/** @file
 *  ICMP module implementation.
 *  @see icmp.h
 */

#include <async.h>
#include <atomic.h>
#include <fibril.h>
#include <fibril_synch.h>
#include <stdint.h>
#include <str.h>
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <sys/time.h>
#include <sys/types.h>
#include <errno.h>
#include <err.h>

#include <net/socket_codes.h>
#include <net/ip_protocols.h>

#include <net_messages.h>
#include <net_modules.h>
#include <packet/packet_client.h>
#include <packet_remote.h>
#include <net_byteorder.h>
#include <net_checksum.h>
#include <icmp_api.h>
#include <icmp_client.h>
#include <icmp_codes.h>
#include <icmp_common.h>
#include <icmp_interface.h>
#include <il_interface.h>
#include <inet.h>
#include <ip_client.h>
#include <ip_interface.h>
#include <net_interface.h>
#include <tl_messages.h>
#include <tl_interface.h>
#include <tl_local.h>
#include <icmp_messages.h>
#include <icmp_header.h>

#include "icmp.h"
#include "icmp_module.h"

/** ICMP module name.
 */
#define NAME	"ICMP protocol"

/** Default ICMP error reporting.
 */
#define NET_DEFAULT_ICMP_ERROR_REPORTING	true

/** Default ICMP echo replying.
 */
#define NET_DEFAULT_ICMP_ECHO_REPLYING		true

/** Original datagram length in bytes transfered to the error notification message.
 */
#define ICMP_KEEP_LENGTH	8

/** Free identifier numbers pool start.
 */
#define ICMP_FREE_IDS_START	1

/** Free identifier numbers pool end.
 */
#define ICMP_FREE_IDS_END	UINT16_MAX

/** Computes the ICMP datagram checksum.
 *  @param[in,out] header The ICMP datagram header.
 *  @param[in] length The total datagram length.
 *  @returns The computed checksum.
 */
#define ICMP_CHECKSUM(header, length)		htons(ip_checksum((uint8_t *) (header), (length)))

/** An echo request datagrams pattern.
 */
#define ICMP_ECHO_TEXT					"Hello from HelenOS."

/** Computes an ICMP reply data key.
 *  @param[in] id The message identifier.
 *  @param[in] sequence The message sequence number.
 *  @returns The computed ICMP reply data key.
 */
#define ICMP_GET_REPLY_KEY(id, sequence)	(((id) << 16) | (sequence &0xFFFF))

/** Processes the received ICMP packet.
 *  Is used as an entry point from the underlying IP module.
 *  Releases the packet on error.
 *  @param device_id The device identifier. Ignored parameter.
 *  @param[in,out] packet The received packet.
 *  @param receiver The target service. Ignored parameter.
 *  @param[in] error The packet error reporting service. Prefixes the received packet.
 *  @returns EOK on success.
 *  @returns Other error codes as defined for the icmp_process_packet() function.
 */
int icmp_received_msg(device_id_t device_id, packet_t packet, services_t receiver, services_t error);

/** Processes the received ICMP packet.
 *  Notifies the destination socket application.
 *  @param[in,out] packet The received packet.
 *  @param[in] error The packet error reporting service. Prefixes the received packet.
 *  @returns EOK on success.
 *  @returns EINVAL if the packet is not valid.
 *  @returns EINVAL if the stored packet address is not the an_addr_t.
 *  @returns EINVAL if the packet does not contain any data.
 *  @returns NO_DATA if the packet content is shorter than the user datagram header.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns EADDRNOTAVAIL if the destination socket does not exist.
 *  @returns Other error codes as defined for the ip_client_process_packet() function.
 */
int icmp_process_packet(packet_t packet, services_t error);

/** Processes the client messages.
 *  Remembers the assigned identifier and sequence numbers.
 *  Runs until the client module disconnects.
 *  @param[in] callid The message identifier.
 *  @param[in] call The message parameters.
 *  @returns EOK.
 *  @see icmp_interface.h
 *  @see icmp_api.h
 */
int icmp_process_client_messages(ipc_callid_t callid, ipc_call_t call);

/** Processes the generic client messages.
 *  @param[in] call The message parameters.
 *  @returns EOK on success.
 *  @returns ENOTSUP if the message is not known.
 *  @returns Other error codes as defined for the packet_translate() function.
 *  @returns Other error codes as defined for the icmp_destination_unreachable_msg() function.
 *  @returns Other error codes as defined for the icmp_source_quench_msg() function.
 *  @returns Other error codes as defined for the icmp_time_exceeded_msg() function.
 *  @returns Other error codes as defined for the icmp_parameter_problem_msg() function.
 *  @see icmp_interface.h
 */
int icmp_process_message(ipc_call_t * call);

/** Releases the packet and returns the result.
 *  @param[in] packet The packet queue to be released.
 *  @param[in] result The result to be returned.
 *  @returns The result parameter.
 */
int icmp_release_and_return(packet_t packet, int result);

/** Requests an echo message.
 *  Sends a packet with specified parameters to the target host and waits for the reply upto the given timeout.
 *  Blocks the caller until the reply or the timeout occurs.
 *  @param[in] id The message identifier.
 *  @param[in] sequence The message sequence parameter.
 *  @param[in] size The message data length in bytes.
 *  @param[in] timeout The timeout in miliseconds.
 *  @param[in] ttl The time to live.
 *  @param[in] tos The type of service.
 *  @param[in] dont_fragment The value indicating whether the datagram must not be fragmented. Is used as a MTU discovery.
 *  @param[in] addr The target host address.
 *  @param[in] addrlen The torget host address length.
 *  @returns ICMP_ECHO on success.
 *  @returns ETIMEOUT if the reply has not arrived before the timeout.
 *  @returns ICMP type of the received error notification. 
 *  @returns EINVAL if the addrlen parameter is less or equal to zero (<=0).
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns EPARTY if there was an internal error.
 */
int icmp_echo(icmp_param_t id, icmp_param_t sequence, size_t size, mseconds_t timeout, ip_ttl_t ttl, ip_tos_t tos, int dont_fragment, const struct sockaddr * addr, socklen_t addrlen);

/** Prepares the ICMP error packet.
 *  Truncates the original packet if longer than ICMP_KEEP_LENGTH bytes.
 *  Prefixes and returns the ICMP header.
 *  @param[in,out] packet The original packet.
 *  @returns The prefixed ICMP header.
 *  @returns NULL on errors.
 */
icmp_header_ref icmp_prepare_packet(packet_t packet);

/** Sends the ICMP message.
 *  Sets the message type and code and computes the checksum.
 *  Error messages are sent only if allowed in the configuration.
 *  Releases the packet on errors.
 *  @param[in] type The message type.
 *  @param[in] code The message code.
 *  @param[in] packet The message packet to be sent.
 *  @param[in] header The ICMP header.
 *  @param[in] error The error service to be announced. Should be SERVICE_ICMP or zero (0).
 *  @param[in] ttl The time to live.
 *  @param[in] tos The type of service.
 *  @param[in] dont_fragment The value indicating whether the datagram must not be fragmented. Is used as a MTU discovery.
 *  @returns EOK on success.
 *  @returns EPERM if the error message is not allowed.
 */
int icmp_send_packet(icmp_type_t type, icmp_code_t code, packet_t packet, icmp_header_ref header, services_t error, ip_ttl_t ttl, ip_tos_t tos, int dont_fragment);

/** Tries to set the pending reply result as the received message type.
 *  If the reply data is not present, the reply timed out and the other fibril
 *  is already awake.
 *  Releases the packet.
 *  @param[in] packet The received reply message.
 *  @param[in] header The ICMP message header.
 *  @param[in] type The received reply message type.
 *  @param[in] code The received reply message code.
 *  @returns EOK.
 */
int icmp_process_echo_reply(packet_t packet, icmp_header_ref header, icmp_type_t type, icmp_code_t code);

/** Assigns a new identifier for the connection.
 *  Fills the echo data parameter with the assigned values.
 *  @param[in,out] echo_data The echo data to be bound.
 *  @returns Index of the inserted echo data.
 *  @returns EBADMEM if the echo_data parameter is NULL.
 *  @returns ENOTCONN if no free identifier have been found.
 */
int icmp_bind_free_id(icmp_echo_ref echo_data);

/** ICMP global data.
 */
icmp_globals_t	icmp_globals;

INT_MAP_IMPLEMENT(icmp_replies, icmp_reply_t);

INT_MAP_IMPLEMENT(icmp_echo_data, icmp_echo_t);

int icmp_echo_msg(int icmp_phone, size_t size, mseconds_t timeout, ip_ttl_t ttl, ip_tos_t tos, int dont_fragment, const struct sockaddr * addr, socklen_t addrlen){
	icmp_echo_ref echo_data;
	int res;

	fibril_rwlock_write_lock(&icmp_globals.lock);
	// use the phone as the echo data index
	echo_data = icmp_echo_data_find(&icmp_globals.echo_data, icmp_phone);
	if(! echo_data){
		res = ENOENT;
	}else{
		res = icmp_echo(echo_data->identifier, echo_data->sequence_number, size, timeout, ttl, tos, dont_fragment, addr, addrlen);
		if(echo_data->sequence_number < UINT16_MAX){
			++ echo_data->sequence_number;
		}else{
			echo_data->sequence_number = 0;
		}
	}
	fibril_rwlock_write_unlock(&icmp_globals.lock);
	return res;
}

int icmp_echo(icmp_param_t id, icmp_param_t sequence, size_t size, mseconds_t timeout, ip_ttl_t ttl, ip_tos_t tos, int dont_fragment, const struct sockaddr * addr, socklen_t addrlen){
	ERROR_DECLARE;

	icmp_header_ref header;
	packet_t packet;
	size_t length;
	uint8_t * data;
	icmp_reply_ref reply;
	int reply_key;
	int result;
	int index;

	if(addrlen <= 0){
		return EINVAL;
	}
	length = (size_t) addrlen;
	// TODO do not ask all the time
	ERROR_PROPAGATE(ip_packet_size_req(icmp_globals.ip_phone, -1, &icmp_globals.packet_dimension));
	packet = packet_get_4_remote(icmp_globals.net_phone, size, icmp_globals.packet_dimension.addr_len, ICMP_HEADER_SIZE + icmp_globals.packet_dimension.prefix, icmp_globals.packet_dimension.suffix);
	if(! packet){
		return ENOMEM;
	}

	// prepare the requesting packet
	// set the destination address
	if(ERROR_OCCURRED(packet_set_addr(packet, NULL, (const uint8_t *) addr, length))){
		return icmp_release_and_return(packet, ERROR_CODE);
	}
	// allocate space in the packet
	data = (uint8_t *) packet_suffix(packet, size);
	if(! data){
		return icmp_release_and_return(packet, ENOMEM);
	}
	// fill the data
	length = 0;
	while(size > length + sizeof(ICMP_ECHO_TEXT)){
		memcpy(data + length, ICMP_ECHO_TEXT, sizeof(ICMP_ECHO_TEXT));
		length += sizeof(ICMP_ECHO_TEXT);
	}
	memcpy(data + length, ICMP_ECHO_TEXT, size - length);
	// prefix the header
	header = PACKET_PREFIX(packet, icmp_header_t);
	if(! header){
		return icmp_release_and_return(packet, ENOMEM);
	}
	bzero(header, sizeof(*header));
	header->un.echo.identifier = id;
	header->un.echo.sequence_number = sequence;

	// prepare the reply structure
	reply = malloc(sizeof(*reply));
	if(! reply){
		return icmp_release_and_return(packet, ENOMEM);
	}
	fibril_mutex_initialize(&reply->mutex);
	fibril_mutex_lock(&reply->mutex);
	fibril_condvar_initialize(&reply->condvar);
	reply_key = ICMP_GET_REPLY_KEY(header->un.echo.identifier, header->un.echo.sequence_number);
	index = icmp_replies_add(&icmp_globals.replies, reply_key, reply);
	if(index < 0){
		free(reply);
		return icmp_release_and_return(packet, index);
	}

	// unlock the globals so that we can wait for the reply
	fibril_rwlock_write_unlock(&icmp_globals.lock);

	// send the request
	icmp_send_packet(ICMP_ECHO, 0, packet, header, 0, ttl, tos, dont_fragment);

	// wait for the reply
	// timeout in microseconds
	if(ERROR_OCCURRED(fibril_condvar_wait_timeout(&reply->condvar, &reply->mutex, timeout * 1000))){
		result = ERROR_CODE;
	}else{
		// read the result
		result = reply->result;
	}

	// drop the reply mutex before locking the globals again
	fibril_mutex_unlock(&reply->mutex);
	fibril_rwlock_write_lock(&icmp_globals.lock);

	// destroy the reply structure
	icmp_replies_exclude_index(&icmp_globals.replies, index);
	return result;
}

int icmp_destination_unreachable_msg(int icmp_phone, icmp_code_t code, icmp_param_t mtu, packet_t packet){
	icmp_header_ref header;

	header = icmp_prepare_packet(packet);
	if(! header){
		return icmp_release_and_return(packet, ENOMEM);
	}
	if(mtu){
		header->un.frag.mtu = mtu;
	}
	return icmp_send_packet(ICMP_DEST_UNREACH, code, packet, header, SERVICE_ICMP, 0, 0, 0);
}

int icmp_source_quench_msg(int icmp_phone, packet_t packet){
	icmp_header_ref header;

	header = icmp_prepare_packet(packet);
	if(! header){
		return icmp_release_and_return(packet, ENOMEM);
	}
	return icmp_send_packet(ICMP_SOURCE_QUENCH, 0, packet, header, SERVICE_ICMP, 0, 0, 0);
}

int icmp_time_exceeded_msg(int icmp_phone, icmp_code_t code, packet_t packet){
	icmp_header_ref header;

	header = icmp_prepare_packet(packet);
	if(! header){
		return icmp_release_and_return(packet, ENOMEM);
	}
	return icmp_send_packet(ICMP_TIME_EXCEEDED, code, packet, header, SERVICE_ICMP, 0, 0, 0);
}

int icmp_parameter_problem_msg(int icmp_phone, icmp_code_t code, icmp_param_t pointer, packet_t packet){
	icmp_header_ref header;

	header = icmp_prepare_packet(packet);
	if(! header){
		return icmp_release_and_return(packet, ENOMEM);
	}
	header->un.param.pointer = pointer;
	return icmp_send_packet(ICMP_PARAMETERPROB, code, packet, header, SERVICE_ICMP, 0, 0, 0);
}

icmp_header_ref icmp_prepare_packet(packet_t packet){
	icmp_header_ref header;
	size_t header_length;
	size_t total_length;

	total_length = packet_get_data_length(packet);
	if(total_length <= 0){
		return NULL;
	}
	header_length = ip_client_header_length(packet);
	if(header_length <= 0){
		return NULL;
	}
	// truncate if longer than 64 bits (without the IP header)
	if((total_length > header_length + ICMP_KEEP_LENGTH)
		&& (packet_trim(packet, 0, total_length - header_length - ICMP_KEEP_LENGTH) != EOK)){
		return NULL;
	}
	header = PACKET_PREFIX(packet, icmp_header_t);
	if(! header){
		return NULL;
	}
	bzero(header, sizeof(*header));
	return header;
}

int icmp_send_packet(icmp_type_t type, icmp_code_t code, packet_t packet, icmp_header_ref header, services_t error, ip_ttl_t ttl, ip_tos_t tos, int dont_fragment){
	ERROR_DECLARE;

	// do not send an error if disabled
	if(error && (! icmp_globals.error_reporting)){
		return icmp_release_and_return(packet, EPERM);
	}
	header->type = type;
	header->code = code;
	header->checksum = 0;
	header->checksum = ICMP_CHECKSUM(header, packet_get_data_length(packet));
	if(ERROR_OCCURRED(ip_client_prepare_packet(packet, IPPROTO_ICMP, ttl, tos, dont_fragment, 0))){
		return icmp_release_and_return(packet, ERROR_CODE);
	}
	return ip_send_msg(icmp_globals.ip_phone, -1, packet, SERVICE_ICMP, error);
}

int icmp_connect_module(services_t service, suseconds_t timeout){
	icmp_echo_ref echo_data;
	icmp_param_t id;
	int index;

	echo_data = (icmp_echo_ref) malloc(sizeof(*echo_data));
	if(! echo_data){
		return ENOMEM;
	}
	// assign a new identifier
	fibril_rwlock_write_lock(&icmp_globals.lock);
	index = icmp_bind_free_id(echo_data);
	if(index < 0){
		free(echo_data);
		fibril_rwlock_write_unlock(&icmp_globals.lock);
		return index;
	}else{
		id = echo_data->identifier;
		fibril_rwlock_write_unlock(&icmp_globals.lock);
		// return the echo data identifier as the ICMP phone
		return id;
	}
}

int icmp_initialize(async_client_conn_t client_connection){
	ERROR_DECLARE;

	measured_string_t names[] = {{str_dup("ICMP_ERROR_REPORTING"), 20}, {str_dup("ICMP_ECHO_REPLYING"), 18}};
	measured_string_ref configuration;
	size_t count = sizeof(names) / sizeof(measured_string_t);
	char * data;

	fibril_rwlock_initialize(&icmp_globals.lock);
	fibril_rwlock_write_lock(&icmp_globals.lock);
	icmp_replies_initialize(&icmp_globals.replies);
	icmp_echo_data_initialize(&icmp_globals.echo_data);
	icmp_globals.ip_phone = ip_bind_service(SERVICE_IP, IPPROTO_ICMP, SERVICE_ICMP, client_connection, icmp_received_msg);
	if(icmp_globals.ip_phone < 0){
		return icmp_globals.ip_phone;
	}
	ERROR_PROPAGATE(ip_packet_size_req(icmp_globals.ip_phone, -1, &icmp_globals.packet_dimension));
	icmp_globals.packet_dimension.prefix += ICMP_HEADER_SIZE;
	icmp_globals.packet_dimension.content -= ICMP_HEADER_SIZE;
	// get configuration
	icmp_globals.error_reporting = NET_DEFAULT_ICMP_ERROR_REPORTING;
	icmp_globals.echo_replying = NET_DEFAULT_ICMP_ECHO_REPLYING;
	configuration = &names[0];
	ERROR_PROPAGATE(net_get_conf_req(icmp_globals.net_phone, &configuration, count, &data));
	if(configuration){
		if(configuration[0].value){
			icmp_globals.error_reporting = (configuration[0].value[0] == 'y');
		}
		if(configuration[1].value){
			icmp_globals.echo_replying = (configuration[1].value[0] == 'y');
		}
		net_free_settings(configuration, data);
	}
	fibril_rwlock_write_unlock(&icmp_globals.lock);
	return EOK;
}

int icmp_received_msg(device_id_t device_id, packet_t packet, services_t receiver, services_t error){
	ERROR_DECLARE;

	if(ERROR_OCCURRED(icmp_process_packet(packet, error))){
		return icmp_release_and_return(packet, ERROR_CODE);
	}

	return EOK;
}

int icmp_process_packet(packet_t packet, services_t error){
	ERROR_DECLARE;

	size_t length;
	uint8_t * src;
	int addrlen;
	int result;
	void * data;
	icmp_header_ref header;
	icmp_type_t type;
	icmp_code_t code;

	if(error){
		switch(error){
			case SERVICE_ICMP:
				// process error
				result = icmp_client_process_packet(packet, &type, &code, NULL, NULL);
				if(result < 0){
					return result;
				}
				length = (size_t) result;
				// remove the error header
				ERROR_PROPAGATE(packet_trim(packet, length, 0));
				break;
			default:
				return ENOTSUP;
		}
	}
	// get rid of the ip header
	length = ip_client_header_length(packet);
	ERROR_PROPAGATE(packet_trim(packet, length, 0));

	length = packet_get_data_length(packet);
	if(length <= 0){
		return EINVAL;
	}
	if(length < ICMP_HEADER_SIZE){
		return EINVAL;
	}
	data = packet_get_data(packet);
	if(! data){
		return EINVAL;
	}
	// get icmp header
	header = (icmp_header_ref) data;
	// checksum
	if(header->checksum){
		while(ICMP_CHECKSUM(header, length) != IP_CHECKSUM_ZERO){
			// set the original message type on error notification
			// type swap observed in Qemu
			if(error){
				switch(header->type){
					case ICMP_ECHOREPLY:
						header->type = ICMP_ECHO;
						continue;
				}
			}
			return EINVAL;
		}
	}
	switch(header->type){
		case ICMP_ECHOREPLY:
			if(error){
				return icmp_process_echo_reply(packet, header, type, code);
			}else{
				return icmp_process_echo_reply(packet, header, ICMP_ECHO, 0);
			}
		case ICMP_ECHO:
			if(error){
				return icmp_process_echo_reply(packet, header, type, code);
			// do not send a reply if disabled
			}else if(icmp_globals.echo_replying){
				addrlen = packet_get_addr(packet, &src, NULL);
				if((addrlen > 0)
				// set both addresses to the source one (avoids the source address deletion before setting the destination one)
					&& (packet_set_addr(packet, src, src, (size_t) addrlen) == EOK)){
					// send the reply
					icmp_send_packet(ICMP_ECHOREPLY, 0, packet, header, 0, 0, 0, 0);
					return EOK;
				}else{
					return EINVAL;
				}
			}else{
				return EPERM;
			}
		case ICMP_DEST_UNREACH:
		case ICMP_SOURCE_QUENCH:
		case ICMP_REDIRECT:
		case ICMP_ALTERNATE_ADDR:
		case ICMP_ROUTER_ADV:
		case ICMP_ROUTER_SOL:
		case ICMP_TIME_EXCEEDED:
		case ICMP_PARAMETERPROB:
		case ICMP_CONVERSION_ERROR:
		case ICMP_REDIRECT_MOBILE:
		case ICMP_SKIP:
		case ICMP_PHOTURIS:
			ip_received_error_msg(icmp_globals.ip_phone, -1, packet, SERVICE_IP, SERVICE_ICMP);
			return EOK;
		default:
			return ENOTSUP;
	}
}

int icmp_process_echo_reply(packet_t packet, icmp_header_ref header, icmp_type_t type, icmp_code_t code){
	int reply_key;
	icmp_reply_ref reply;

	// compute the reply key
	reply_key = ICMP_GET_REPLY_KEY(header->un.echo.identifier, header->un.echo.sequence_number);
	pq_release_remote(icmp_globals.net_phone, packet_get_id(packet));
	// lock the globals
	fibril_rwlock_write_lock(&icmp_globals.lock);
	// find the pending reply
	reply = icmp_replies_find(&icmp_globals.replies, reply_key);
	if(reply){
		// set the result
		reply->result = type;
		// notify the waiting fibril
		fibril_condvar_signal(&reply->condvar);
	}
	fibril_rwlock_write_unlock(&icmp_globals.lock);
	return EOK;
}

int icmp_message_standalone(ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count){
	ERROR_DECLARE;

	packet_t packet;

	*answer_count = 0;
	switch(IPC_GET_METHOD(*call)){
		case NET_TL_RECEIVED:
			if(! ERROR_OCCURRED(packet_translate_remote(icmp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				ERROR_CODE = icmp_received_msg(IPC_GET_DEVICE(call), packet, SERVICE_ICMP, IPC_GET_ERROR(call));
			}
			return ERROR_CODE;
		case NET_ICMP_INIT:
			return icmp_process_client_messages(callid, * call);
		default:
			return icmp_process_message(call);
	}
	return ENOTSUP;
}

int icmp_process_client_messages(ipc_callid_t callid, ipc_call_t call){
	ERROR_DECLARE;

	bool keep_on_going = true;
//	fibril_rwlock_t			lock;
	ipc_call_t answer;
	int answer_count;
	size_t length;
	struct sockaddr * addr;
	ipc_callid_t data_callid;
	icmp_echo_ref echo_data;
	int res;

	/*
	 * Accept the connection
	 *  - Answer the first NET_ICMP_INIT call.
	 */
	res = EOK;
	answer_count = 0;

//	fibril_rwlock_initialize(&lock);

	echo_data = (icmp_echo_ref) malloc(sizeof(*echo_data));
	if(! echo_data){
		return ENOMEM;
	}

	// assign a new identifier
	fibril_rwlock_write_lock(&icmp_globals.lock);
	res = icmp_bind_free_id(echo_data);
	fibril_rwlock_write_unlock(&icmp_globals.lock);
	if(res < 0){
		free(echo_data);
		return res;
	}

	while(keep_on_going){

		// answer the call
		answer_call(callid, res, &answer, answer_count);

		// refresh data
		refresh_answer(&answer, &answer_count);

		// get the next call
		callid = async_get_call(&call);

		// process the call
		switch(IPC_GET_METHOD(call)){
			case IPC_M_PHONE_HUNGUP:
				keep_on_going = false;
				res = EHANGUP;
				break;
			case NET_ICMP_ECHO:
//				fibril_rwlock_write_lock(&lock);
				if(! async_data_write_receive(&data_callid, &length)){
					res = EINVAL;
				}else{
					addr = malloc(length);
					if(! addr){
						res = ENOMEM;
					}else{
						if(! ERROR_OCCURRED(async_data_write_finalize(data_callid, addr, length))){
							fibril_rwlock_write_lock(&icmp_globals.lock);
							res = icmp_echo(echo_data->identifier, echo_data->sequence_number, ICMP_GET_SIZE(call), ICMP_GET_TIMEOUT(call), ICMP_GET_TTL(call), ICMP_GET_TOS(call), ICMP_GET_DONT_FRAGMENT(call), addr, (socklen_t) length);
							fibril_rwlock_write_unlock(&icmp_globals.lock);
							free(addr);
							if(echo_data->sequence_number < UINT16_MAX){
								++ echo_data->sequence_number;
							}else{
								echo_data->sequence_number = 0;
							}
						}else{
							res = ERROR_CODE;
						}
					}
				}
//				fibril_rwlock_write_unlock(&lock);
				break;
			default:
				res = icmp_process_message(&call);
		}
	}

	// release the identifier
	fibril_rwlock_write_lock(&icmp_globals.lock);
	icmp_echo_data_exclude(&icmp_globals.echo_data, echo_data->identifier);
	fibril_rwlock_write_unlock(&icmp_globals.lock);
	return res;
}

int icmp_process_message(ipc_call_t * call){
	ERROR_DECLARE;

	packet_t packet;

	switch(IPC_GET_METHOD(*call)){
		case NET_ICMP_DEST_UNREACH:
			if(! ERROR_OCCURRED(packet_translate_remote(icmp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				ERROR_CODE = icmp_destination_unreachable_msg(0, ICMP_GET_CODE(call), ICMP_GET_MTU(call), packet);
			}
			return ERROR_CODE;
		case NET_ICMP_SOURCE_QUENCH:
			if(! ERROR_OCCURRED(packet_translate_remote(icmp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				ERROR_CODE = icmp_source_quench_msg(0, packet);
			}
			return ERROR_CODE;
		case NET_ICMP_TIME_EXCEEDED:
			if(! ERROR_OCCURRED(packet_translate_remote(icmp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				ERROR_CODE = icmp_time_exceeded_msg(0, ICMP_GET_CODE(call), packet);
			}
			return ERROR_CODE;
		case NET_ICMP_PARAMETERPROB:
			if(! ERROR_OCCURRED(packet_translate_remote(icmp_globals.net_phone, &packet, IPC_GET_PACKET(call)))){
				ERROR_CODE = icmp_parameter_problem_msg(0, ICMP_GET_CODE(call), ICMP_GET_POINTER(call), packet);
			}
			return ERROR_CODE;
		default:
			return ENOTSUP;
	}
}

int icmp_release_and_return(packet_t packet, int result){
	pq_release_remote(icmp_globals.net_phone, packet_get_id(packet));
	return result;
}

int icmp_bind_free_id(icmp_echo_ref echo_data){
	icmp_param_t index;

	if(! echo_data){
		return EBADMEM;
	}
	// from the last used one
	index = icmp_globals.last_used_id;
	do{
		++ index;
		// til the range end
		if(index >= ICMP_FREE_IDS_END){
			// start from the range beginning
			index = ICMP_FREE_IDS_START - 1;
			do{
				++ index;
				// til the last used one
				if(index >= icmp_globals.last_used_id){
					// none found
					return ENOTCONN;
				}
			}while(icmp_echo_data_find(&icmp_globals.echo_data, index) != NULL);
			// found, break immediately
			break;
		}
	}while(icmp_echo_data_find(&icmp_globals.echo_data, index) != NULL);
	echo_data->identifier = index;
	echo_data->sequence_number = 0;
	return icmp_echo_data_add(&icmp_globals.echo_data, index, echo_data);
}

/** Default thread for new connections.
 *
 *  @param[in] iid The initial message identifier.
 *  @param[in] icall The initial message call structure.
 *
 */
static void tl_client_connection(ipc_callid_t iid, ipc_call_t * icall)
{
	/*
	 * Accept the connection
	 *  - Answer the first IPC_M_CONNECT_ME_TO call.
	 */
	ipc_answer_0(iid, EOK);
	
	while(true) {
		ipc_call_t answer;
		int answer_count;
		
		/* Clear the answer structure */
		refresh_answer(&answer, &answer_count);
		
		/* Fetch the next message */
		ipc_call_t call;
		ipc_callid_t callid = async_get_call(&call);
		
		/* Process the message */
		int res = tl_module_message_standalone(callid, &call, &answer,
		    &answer_count);
		
		/* End if said to either by the message or the processing result */
		if ((IPC_GET_METHOD(call) == IPC_M_PHONE_HUNGUP) || (res == EHANGUP))
			return;
		
		/* Answer the message */
		answer_call(callid, res, &answer, answer_count);
	}
}

/** Starts the module.
 *
 *  @param argc The count of the command line arguments. Ignored parameter.
 *  @param argv The command line parameters. Ignored parameter.
 *
 *  @returns EOK on success.
 *  @returns Other error codes as defined for each specific module start function.
 *
 */
int main(int argc, char *argv[])
{
	ERROR_DECLARE;
	
	/* Start the module */
	if (ERROR_OCCURRED(tl_module_start_standalone(tl_client_connection)))
		return ERROR_CODE;
	
	return EOK;
}

/** @}
 */