source: mainline/uspace/srv/net/tl/icmp/icmp.c@ 12d7710

/*
 * 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 "../../err.h"
#include "../../messages.h"
#include "../../modules.h"

#include "../../structures/packet/packet_client.h"

#include "../../include/byteorder.h"
#include "../../include/checksum.h"
#include "../../include/icmp_api.h"
#include "../../include/icmp_client.h"
#include "../../include/icmp_codes.h"
#include "../../include/icmp_common.h"
#include "../../include/icmp_interface.h"
#include "../../include/il_interface.h"
#include "../../include/inet.h"
#include "../../include/ip_client.h"
#include "../../include/ip_interface.h"
#include "../../include/ip_protocols.h"
#include "../../include/net_interface.h"
#include "../../include/socket_codes.h"
#include "../../include/socket_errno.h"

#include "../../tl/tl_messages.h"

#include "icmp.h"
#include "icmp_header.h"
#include "icmp_messages.h"
#include "icmp_module.h"

/** 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       MAX_UINT16

/** 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 < MAX_UINT16){
                        ++ 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(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(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(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(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 < MAX_UINT16){
                                                                ++ 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(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(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(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(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(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);
}

/** @}
 */