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  1. /*
  2.  * Copyright (c) 2008 Lukas Mejdrech
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup udp
  30.  *  @{
  31.  */
  32.  
  33. /** @file
  34.  *  UDP module implementation.
  35.  *  @see udp.h
  36.  */
  37.  
  38. #include <async.h>
  39. #include <fibril_sync.h>
  40. #include <malloc.h>
  41.  
  42. #include <ipc/ipc.h>
  43. #include <ipc/services.h>
  44.  
  45. #include "../../err.h"
  46. #include "../../messages.h"
  47. #include "../../modules.h"
  48.  
  49. #include "../../structures/dynamic_fifo.h"
  50. #include "../../structures/packet/packet_client.h"
  51.  
  52. #include "../../include/crc.h"
  53. #include "../../include/in.h"
  54. #include "../../include/in6.h"
  55. #include "../../include/inet.h"
  56. #include "../../include/ip_client.h"
  57. #include "../../include/ip_interface.h"
  58. #include "../../include/ip_protocols.h"
  59. #include "../../include/icmp_client.h"
  60. #include "../../include/icmp_interface.h"
  61. #include "../../include/net_interface.h"
  62. #include "../../include/socket_codes.h"
  63. #include "../../include/socket_errno.h"
  64.  
  65. #include "../../socket/socket_core.h"
  66. #include "../../socket/socket_messages.h"
  67.  
  68. #include "../tl_common.h"
  69. #include "../tl_messages.h"
  70.  
  71. #include "udp.h"
  72. #include "udp_header.h"
  73. #include "udp_module.h"
  74.  
  75. /** Default UDP checksum computing.
  76.  */
  77. #define NET_DEFAULT_UDP_CHECKSUM_COMPUTING  true
  78.  
  79. /** Maximum UDP fragment size.
  80.  */
  81. #define MAX_UDP_FRAGMENT_SIZE   65535
  82.  
  83. /** Free ports pool start.
  84.  */
  85. #define UDP_FREE_PORTS_START    1025
  86.  
  87. /** Free ports pool end.
  88.  */
  89. #define UDP_FREE_PORTS_END      65535
  90.  
  91. /** Processes the received UDP packet queue.
  92.  *  Is used as an entry point from the underlying IP module.
  93.  *  Notifies the destination socket application.
  94.  *  Releases the packet on error or send an ICMP error notification..
  95.  *  @param device_id The device identifier. Ignored parameter.
  96.  *  @param packet The received packet queue. Input/output parameter.
  97.  *  @param receiver The target service. Ignored parameter.
  98.  *  @param error The packet error reporting service. Prefixes the received packet. Input parameter.
  99.  *  @returns EOK on success.
  100.  *  @returns EINVAL if the packet is not valid.
  101.  *  @returns EINVAL if the stored packet address is not the an_addr_t.
  102.  *  @returns EINVAL if the packet does not contain any data.
  103.  *  @returns NO_DATA if the packet content is shorter than the user datagram header.
  104.  *  @returns ENOMEM if there is not enough memory left.
  105.  *  @returns EADDRNOTAVAIL if the destination socket does not exist.
  106.  *  @returns Other error codes as defined for the ip_client_process_packet() function.
  107.  */
  108. int udp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error );
  109.  
  110. /** Releases the packet and returns the result.
  111.  *  @param packet The packet queue to be released. Input parameter.
  112.  *  @param result The result to be returned. Input parameter.
  113.  *  @return The result parameter.
  114.  */
  115. int udp_release_and_return( packet_t packet, int result );
  116.  
  117. /** @name Socket messages processing functions
  118.  */
  119. /*@{*/
  120.  
  121. /** Processes the socket client messages.
  122.  *  Runs until the client module disconnects.
  123.  *  @param callid The message identifier. Input parameter.
  124.  *  @param call The message parameters. Input parameter.
  125.  *  @returns EOK on success.
  126.  *  @see socket.h
  127.  */
  128. int udp_process_client_messages( ipc_callid_t callid, ipc_call_t call );
  129.  
  130. /** Sends data from the socket to the remote address.
  131.  *  Binds the socket to a free port if not already connected/bound.
  132.  *  Handles the NET_SOCKET_SENDTO message.
  133.  *  Supports AF_INET and AF_INET6 address families.
  134.  *  @param local_sockets The application local sockets. Input/output parameter.
  135.  *  @param socket_id Socket identifier. Input parameter.
  136.  *  @param addr The destination address. Input parameter.
  137.  *  @param addrlen The address length. Input parameter.
  138.  *  @param fragments The number of data fragments. Input parameter.
  139.  *  @param data_fragment_size The data fragment size in bytes. Input parameter.
  140.  *  @param flags Various send flags. Input parameter.
  141.  *  @returns EOK on success.
  142.  *  @returns EAFNOTSUPPORT if the address family is not supported.
  143.  *  @returns ENOTSOCK if the socket is not found.
  144.  *  @returns EINVAL if the address is invalid.
  145.  *  @returns ENOTCONN if the sending socket is not and cannot be bound.
  146.  *  @returns ENOMEM if there is not enough memory left.
  147.  *  @returns Other error codes as defined for the socket_read_packet_data() function.
  148.  *  @returns Other error codes as defined for the ip_client_prepare_packet() function.
  149.  *  @returns Other error codes as defined for the ip_send_msg() function.
  150.  */
  151. int udp_sendto_message( socket_cores_ref local_sockets, int socket_id, const struct sockaddr * addr, socklen_t addrlen, int fragments, size_t data_fragment_size, int flags );
  152.  
  153. /** Receives data to the socket.
  154.  *  Handles the NET_SOCKET_RECVFROM message.
  155.  *  Replies the source address as well.
  156.  *  @param local_sockets The application local sockets. Input parameter.
  157.  *  @param socket_id Socket identifier. Input parameter.
  158.  *  @param flags Various receive flags. Input parameter.
  159.  *  @param addrlen The source address length. Output parameter.
  160.  *  @returns The number of bytes received.
  161.  *  @returns ENOTSOCK if the socket is not found.
  162.  *  @returns NO_DATA if there are no received packets or data.
  163.  *  @returns ENOMEM if there is not enough memory left.
  164.  *  @returns EINVAL if the received address is not an IP address.
  165.  *  @returns Other error codes as defined for the packet_translate() function.
  166.  *  @returns Other error codes as defined for the data_reply() function.
  167.  */
  168. int udp_recvfrom_message( socket_cores_ref local_sockets, int socket_id, int flags, size_t * addrlen );
  169.  
  170. /*@}*/
  171.  
  172. /** UDP global data.
  173.  */
  174. udp_globals_t   udp_globals;
  175.  
  176. int udp_initialize( async_client_conn_t client_connection ){
  177.     ERROR_DECLARE;
  178.  
  179.     measured_string_t   names[] = {{ "UDP_CHECKSUM_COMPUTING", 22 }};
  180.     measured_string_ref configuration;
  181.     size_t              count = sizeof( names ) / sizeof( measured_string_t );
  182.     char *              data;
  183.  
  184.     fibril_rwlock_initialize( & udp_globals.lock );
  185.     fibril_rwlock_write_lock( & udp_globals.lock );
  186.     udp_globals.icmp_phone = icmp_connect_module( SERVICE_ICMP );
  187.     if( udp_globals.icmp_phone < 0 ){
  188.         return udp_globals.icmp_phone;
  189.     }
  190.     udp_globals.ip_phone = ip_bind_service( SERVICE_IP, IPPROTO_UDP, SERVICE_UDP, client_connection, udp_received_msg );
  191.     if( udp_globals.ip_phone < 0 ){
  192.         return udp_globals.ip_phone;
  193.     }
  194.     ERROR_PROPAGATE( ip_packet_size_req( udp_globals.ip_phone, -1, & udp_globals.packet_dimension.addr_len, & udp_globals.packet_dimension.prefix, & udp_globals.packet_dimension.content, & udp_globals.packet_dimension.suffix ));
  195.     ERROR_PROPAGATE( socket_ports_initialize( & udp_globals.sockets ));
  196.     udp_globals.packet_dimension.prefix += sizeof( udp_header_t );
  197.     udp_globals.packet_dimension.content -= sizeof( udp_header_t );
  198.     udp_globals.last_used_port = UDP_FREE_PORTS_START - 1;
  199.     // get configuration
  200.     udp_globals.checksum_computing = NET_DEFAULT_UDP_CHECKSUM_COMPUTING;
  201.     configuration = & names[ 0 ];
  202.     ERROR_PROPAGATE( net_get_conf_req( udp_globals.net_phone, & configuration, count, & data ));
  203.     if( configuration ){
  204.         if( configuration[ 0 ].value ){
  205.             udp_globals.checksum_computing = ( configuration[ 0 ].value[ 0 ] == 'y' );
  206.         }
  207.         net_free_settings( configuration, data );
  208.     }
  209.     fibril_rwlock_write_unlock( & udp_globals.lock );
  210.     return EOK;
  211. }
  212.  
  213. int udp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error ){
  214.     ERROR_DECLARE;
  215.  
  216.     size_t          length;
  217.     size_t          offset;
  218.     int             result;
  219.     uint8_t *       data;
  220.     udp_header_ref  header;
  221.     socket_core_ref *   socket;
  222.     packet_t        next_packet;
  223.     size_t          total_length;
  224.     uint32_t        checksum;
  225.     int             fragments;
  226.     packet_t        tmp_packet;
  227.     icmp_type_t     type;
  228.     icmp_code_t     code;
  229.     ip_pseudo_header_ref    ip_header;
  230.     struct sockaddr *       src;
  231.     struct sockaddr *       dest;
  232.  
  233.     if( error ){
  234.         switch( error ){
  235.             case SERVICE_ICMP:
  236.                 // process error
  237.                 // TODO remove debug dump
  238.                 // length = icmp_client_header_length( packet );
  239.                 result = icmp_client_process_packet( packet, & type, & code, NULL, NULL );
  240.                 if( result < 0 ){
  241.                     return udp_release_and_return( packet, result );
  242.                 }
  243.                 printf( "ICMP error %d (%d) in packet %d\n", type, code, packet_get_id( packet ) );
  244.                 length = ( size_t ) result;
  245.                 if( ERROR_OCCURRED( packet_trim( packet, length, 0 ))){
  246.                     return udp_release_and_return( packet, ERROR_CODE );
  247.                 }
  248.                 break;
  249.             default:
  250.                 return udp_release_and_return( packet, ENOTSUP );
  251.         }
  252.     }
  253.     // TODO process received ipopts?
  254.     result = ip_client_process_packet( packet, NULL, NULL, NULL, NULL, NULL );
  255.     if( result < 0 ){
  256.         return udp_release_and_return( packet, result );
  257.     }
  258.     offset = ( size_t ) result;
  259.  
  260.     length = packet_get_data_length( packet );
  261.     if( length <= 0 ){
  262.         return udp_release_and_return( packet, EINVAL );
  263.     }
  264.     if( length < sizeof( udp_header_t ) + offset ){
  265.         return udp_release_and_return( packet, NO_DATA );
  266.     }
  267.     data = packet_get_data( packet );
  268.     if( ! data ){
  269.         return udp_release_and_return( packet, NO_DATA );
  270.     }
  271.     // get udp header
  272.     header = ( udp_header_ref )( data + offset );
  273.     // find the destination socket
  274.     socket = socket_ports_find( & udp_globals.sockets, ntohs( header->destination_port ));
  275.     if( ! socket ){
  276.         tl_send_icmp_port_unreachable( udp_globals.net_phone, udp_globals.icmp_phone, packet, error );
  277.         return EADDRNOTAVAIL;
  278.     }
  279.     // trim after successful processing to be able to send an ICMP error message!
  280.     ERROR_PROPAGATE( packet_trim( packet, offset, 0 ));
  281.     // count the received packet fragments
  282.     next_packet = packet;
  283.     fragments = 0;
  284.     total_length = ntohs( header->total_length );
  285.     // compute header checksum if set
  286.     if( header->checksum && ( ! error )){
  287.         result = packet_get_addr( packet, ( uint8_t ** ) & src, ( uint8_t ** ) & dest );
  288.         if( result <= 0 ){
  289.             return udp_release_and_return( packet, result );
  290.         }
  291.         if( ERROR_OCCURRED( ip_client_get_pseudo_header( IPPROTO_UDP, src, result, dest, result, total_length, & ip_header, & length ))){
  292.             return udp_release_and_return( packet, ERROR_CODE );
  293.         }else{
  294.             checksum = compute_checksum( 0, ip_header, length );
  295.             // the udp header checksum will be added with the first fragment later
  296.             free( ip_header );
  297.         }
  298.     }else{
  299.         header->checksum = 0;
  300.         checksum = 0;
  301.     }
  302.     do{
  303.         ++ fragments;
  304.         length = packet_get_data_length( next_packet );
  305.         if( length <= 0 ){
  306.             return udp_release_and_return( packet, NO_DATA );
  307.         }
  308.         if( total_length < length ){
  309.             if( ERROR_OCCURRED( packet_trim( next_packet, 0, length - total_length ))){
  310.                 return udp_release_and_return( packet, ERROR_CODE );
  311.             }
  312.             // add partial checksum if set
  313.             if( header->checksum ){
  314.                 checksum = compute_checksum( checksum, packet_get_data( packet ), packet_get_data_length( packet ));
  315.             }
  316.             // relese the rest of the packet fragments
  317.             tmp_packet = pq_next( next_packet );
  318.             while( tmp_packet ){
  319.                 next_packet = pq_detach( tmp_packet );
  320.                 pq_release( udp_globals.net_phone, packet_get_id( tmp_packet ));
  321.                 tmp_packet = next_packet;
  322.             }
  323.             // exit the loop
  324.             break;
  325.         }
  326.         total_length -= length;
  327.         // add partial checksum if set
  328.         if( header->checksum ){
  329.             checksum = compute_checksum( checksum, packet_get_data( packet ), packet_get_data_length( packet ));
  330.         }
  331.     }while(( next_packet = pq_next( next_packet )) && ( total_length > 0 ));
  332.     // check checksum
  333.     if( header->checksum ){
  334.         if( flip_checksum( compact_checksum( checksum ))){
  335.             // TODO checksum error ICMP?
  336.             // TODO remove debug dump
  337.             printf("udp check failed %x => %x\n", header->checksum, flip_checksum( compact_checksum( checksum )));
  338.             return udp_release_and_return( packet, EINVAL );
  339.         }
  340.     }
  341.     // queue the received packet
  342.     if( ERROR_OCCURRED( dyn_fifo_push( &( ** socket ).received, packet_get_id( packet ), SOCKET_MAX_RECEIVED_SIZE ))){
  343.         return udp_release_and_return( packet, ERROR_CODE );
  344.     }
  345.  
  346.     // notify the destination socket
  347.     async_msg_5(( ** socket ).phone, NET_SOCKET_RECEIVED, ( ipcarg_t ) ( ** socket ).socket_id, 0, 0, 0, ( ipcarg_t ) fragments );
  348.     return EOK;
  349. }
  350.  
  351. int udp_message( ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count ){
  352.     ERROR_DECLARE;
  353.  
  354.     packet_t    packet;
  355.  
  356.     * answer_count = 0;
  357.     switch( IPC_GET_METHOD( * call )){
  358.         case NET_TL_RECEIVED:
  359.             fibril_rwlock_read_lock( & udp_globals.lock );
  360.             if( ! ERROR_OCCURRED( packet_translate( udp_globals.net_phone, & packet, IPC_GET_PACKET( call )))){
  361.                 ERROR_CODE = udp_received_msg( IPC_GET_DEVICE( call ), packet, SERVICE_UDP, IPC_GET_ERROR( call ));
  362.             }
  363.             fibril_rwlock_read_unlock( & udp_globals.lock );
  364.             return ERROR_CODE;
  365.         case IPC_M_CONNECT_TO_ME:
  366.             return udp_process_client_messages( callid, * call );
  367.     }
  368.     return ENOTSUP;
  369. }
  370.  
  371. int udp_process_client_messages( ipc_callid_t callid, ipc_call_t call ){
  372.     int                     res;
  373.     bool                    keep_on_going = true;
  374.     socket_cores_t          local_sockets;
  375.     int                     app_phone = IPC_GET_PHONE( & call );
  376.     struct sockaddr *       addr;
  377.     size_t                  addrlen;
  378. //  fibril_rwlock_t         lock;
  379.     ipc_call_t              answer;
  380.     int                     answer_count;
  381.  
  382.     /*
  383.      * Accept the connection
  384.      *  - Answer the first IPC_M_CONNECT_ME_TO call.
  385.      */
  386.     ipc_answer_0( callid, EOK );
  387.  
  388.     // The client connection is only in one fibril and therefore no additional locks are needed.
  389.  
  390.     socket_cores_initialize( & local_sockets );
  391. //  fibril_rwlock_initialize( & lock );
  392.  
  393.     while( keep_on_going ){
  394.         // refresh data
  395.         refresh_answer( & answer, & answer_count );
  396.  
  397.         callid = async_get_call( & call );
  398. //      printf( "message %d\n", IPC_GET_METHOD( * call ));
  399.  
  400.         switch( IPC_GET_METHOD( call )){
  401.             case IPC_M_PHONE_HUNGUP:
  402.                 keep_on_going = false;
  403.                 res = EOK;
  404.                 break;
  405.             case NET_SOCKET:
  406. //              fibril_rwlock_write_lock( & lock );
  407.                 res = socket_create( & local_sockets, app_phone, NULL, SOCKET_SET_SOCKET_ID( answer ));
  408. //              fibril_rwlock_write_unlock( & lock );
  409.                 * SOCKET_SET_DATA_FRAGMENT_SIZE( answer ) = MAX_UDP_FRAGMENT_SIZE;
  410.                 * SOCKET_SET_HEADER_SIZE( answer ) = sizeof( udp_header_t );
  411.                 answer_count = 3;
  412.                 break;
  413.             case NET_SOCKET_BIND:
  414.                 res = data_receive(( void ** ) & addr, & addrlen );
  415.                 if( res == EOK ){
  416. //                  fibril_rwlock_write_lock( & lock );
  417.                     fibril_rwlock_write_lock( & udp_globals.lock );
  418.                     res = socket_bind( & local_sockets, & udp_globals.sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen, UDP_FREE_PORTS_START, UDP_FREE_PORTS_END, udp_globals.last_used_port );
  419.                     fibril_rwlock_write_unlock( & udp_globals.lock );
  420. //                  fibril_rwlock_write_unlock( & lock );
  421.                     free( addr );
  422.                 }
  423.                 break;
  424.             case NET_SOCKET_SENDTO:
  425.                 res = data_receive(( void ** ) & addr, & addrlen );
  426.                 if( res == EOK ){
  427. //                  fibril_rwlock_read_lock( & lock );
  428.                     fibril_rwlock_read_lock( & udp_globals.lock );
  429.                     res = udp_sendto_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen, SOCKET_GET_DATA_FRAGMENTS( call ), SOCKET_GET_DATA_FRAGMENT_SIZE( call ), SOCKET_GET_FLAGS( call ));
  430.                     fibril_rwlock_read_unlock( & udp_globals.lock );
  431. //                  fibril_rwlock_read_unlock( & lock );
  432.                     free( addr );
  433.                 }
  434.                 break;
  435.             case NET_SOCKET_RECVFROM:
  436. //              fibril_rwlock_read_lock( & lock );
  437.                 fibril_rwlock_read_lock( & udp_globals.lock );
  438.                 res = udp_recvfrom_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_FLAGS( call ), & addrlen );
  439.                 fibril_rwlock_read_unlock( & udp_globals.lock );
  440. //              fibril_rwlock_read_unlock( & lock );
  441.                 if( res > 0 ){
  442.                     * SOCKET_SET_READ_DATA_LENGTH( answer ) = res;
  443.                     * SOCKET_SET_ADDRESS_LENGTH( answer ) = addrlen;
  444.                     answer_count = 2;
  445.                     res = EOK;
  446.                 }
  447.                 break;
  448.             case NET_SOCKET_CLOSE:
  449. //              fibril_rwlock_write_lock( & lock );
  450.                 fibril_rwlock_write_lock( & udp_globals.lock );
  451.                 res = socket_destroy( udp_globals.net_phone, SOCKET_GET_SOCKET_ID( call ), & local_sockets, & udp_globals.sockets );
  452.                 fibril_rwlock_write_unlock( & udp_globals.lock );
  453. //              fibril_rwlock_write_unlock( & lock );
  454.                 break;
  455.             case NET_SOCKET_GETSOCKOPT:
  456.             case NET_SOCKET_SETSOCKOPT:
  457.             default:
  458.                 res = ENOTSUP;
  459.                 break;
  460.         }
  461.  
  462. //      printf( "res = %d\n", res );
  463.  
  464.         answer_call( callid, res, & answer, answer_count );
  465.     }
  466.  
  467.     // TODO call socket_destroy() on all bound!
  468.     socket_cores_destroy( & local_sockets );
  469.  
  470.     return EOK;
  471. }
  472.  
  473. int udp_sendto_message( socket_cores_ref local_sockets, int socket_id, const struct sockaddr * addr, socklen_t addrlen, int fragments, size_t data_fragment_size, int flags ){
  474.     ERROR_DECLARE;
  475.  
  476.     socket_core_ref         socket;
  477.     packet_t                packet;
  478.     packet_t                next_packet;
  479.     udp_header_ref          header;
  480.     int                     index;
  481.     size_t                  total_length;
  482.     int                     result;
  483.     uint16_t                dest_port;
  484.     uint32_t                checksum;
  485.     ip_pseudo_header_ref    ip_header;
  486.     size_t                  headerlen;
  487.     device_id_t             device_id;
  488.  
  489.     ERROR_PROPAGATE( tl_get_address_port( addr, addrlen, & dest_port ));
  490.  
  491.     socket = socket_cores_find( local_sockets, socket_id );
  492.     if( ! socket ) return ENOTSOCK;
  493.  
  494.     // bind the socket to a random free port if not bound
  495.     while( socket->port <= 0 ){
  496.         // try to find a free port
  497.         fibril_rwlock_read_unlock( & udp_globals.lock );
  498.         fibril_rwlock_write_lock( & udp_globals.lock );
  499.         if( socket->port <= 0 ){
  500.             ERROR_PROPAGATE( socket_bind_free_port( & udp_globals.sockets, socket, UDP_FREE_PORTS_START, UDP_FREE_PORTS_END, udp_globals.last_used_port ));
  501.             // set the next port as the search starting port number
  502.             udp_globals.last_used_port = socket->port;
  503.         }
  504.         fibril_rwlock_write_unlock( & udp_globals.lock );
  505.         fibril_rwlock_read_lock( & udp_globals.lock );
  506.     }
  507.  
  508.     // TODO do not ask all the time
  509.     ERROR_PROPAGATE( ip_packet_size_req( udp_globals.ip_phone, -1, & udp_globals.packet_dimension.addr_len, & udp_globals.packet_dimension.prefix, & udp_globals.packet_dimension.content, & udp_globals.packet_dimension.suffix ));
  510.  
  511.     // read the first packet fragment
  512.     result = tl_socket_read_packet_data( udp_globals.net_phone, & packet, sizeof( udp_header_t ), & udp_globals.packet_dimension, addr, addrlen );
  513.     if( result < 0 ) return result;
  514.     total_length = ( size_t ) result;
  515.     if( udp_globals.checksum_computing ){
  516.         checksum = compute_checksum( 0, packet_get_data( packet ), packet_get_data_length( packet ));
  517.     }else{
  518.         checksum = 0;
  519.     }
  520.     // prefix the udp header
  521.     header = PACKET_PREFIX( packet, udp_header_t );
  522.     if( ! header ){
  523.         return udp_release_and_return( packet, ENOMEM );
  524.     }
  525.     bzero( header, sizeof( * header ));
  526.     // read the rest of the packet fragments
  527.     for( index = 1; index < fragments; ++ index ){
  528.         result = tl_socket_read_packet_data( udp_globals.net_phone, & next_packet, 0, & udp_globals.packet_dimension, addr, addrlen );
  529.         if( result < 0 ){
  530.             return udp_release_and_return( packet, result );
  531.         }
  532.         packet = pq_add( packet, next_packet, index, 0 );
  533.         total_length += ( size_t ) result;
  534.         if( udp_globals.checksum_computing ){
  535.             checksum = compute_checksum( checksum, packet_get_data( next_packet ), packet_get_data_length( next_packet ));
  536.         }
  537.     }
  538.     // set the udp header
  539.     header->source_port = htons( socket->port );
  540.     header->destination_port = htons( dest_port );
  541.     header->total_length = htons( total_length + sizeof( udp_header_t ));
  542.     header->checksum = 0;
  543.     if( udp_globals.checksum_computing ){
  544.         if( ERROR_OCCURRED( ip_get_route_req( udp_globals.ip_phone, IPPROTO_UDP, addr, addrlen, & device_id, & ip_header, & headerlen ))){
  545.             return udp_release_and_return( packet, ERROR_CODE );
  546.         }
  547.         if( ERROR_OCCURRED( ip_client_set_pseudo_header_data_length( ip_header, headerlen, total_length + sizeof( udp_header_t )))){
  548.             free( ip_header );
  549.             return udp_release_and_return( packet, ERROR_CODE );
  550.         }
  551. /*//        TODO remove debug dump:
  552.         uint8_t *   data;
  553.         data = ip_header;
  554.         printf( "ip_header:\tlength\t= %d\n\tdata\t= %.2hhX %.2hhX %.2hhX %.2hhX:%.2hhX %.2hhX %.2hhX %.2hhX:%.2hhX %.2hhX %.2hhX %.2hhX\n", headerlen, data[ 0 ], data[ 1 ], data[ 2 ], data[ 3 ], data[ 4 ], data[ 5 ], data[ 6 ], data[ 7 ], data[ 8 ], data[ 9 ], data[ 10 ], data[ 11 ] );
  555. */      checksum = compute_checksum( checksum, ip_header, headerlen );
  556.         checksum = compute_checksum( checksum, ( uint8_t * ) header, sizeof( * header ));
  557.         header->checksum = htons( flip_checksum( compact_checksum( checksum )));
  558.         free( ip_header );
  559.     }else{
  560.         device_id = -1;
  561.     }
  562.     // prepare the first packet fragment
  563.     if( ERROR_OCCURRED( ip_client_prepare_packet( packet, IPPROTO_UDP, 0, 0, 0, 0 ))){
  564.         return udp_release_and_return( packet, ERROR_CODE );
  565.     }
  566.     // send the packet
  567.     return ip_send_msg( udp_globals.ip_phone, device_id, packet, SERVICE_UDP, 0 );
  568. }
  569.  
  570. int udp_recvfrom_message( socket_cores_ref local_sockets, int socket_id, int flags, size_t * addrlen ){
  571.     ERROR_DECLARE;
  572.  
  573.     socket_core_ref socket;
  574.     int             packet_id;
  575.     packet_t        packet;
  576.     udp_header_ref  header;
  577.     struct sockaddr *   addr;
  578.     size_t          length;
  579.     packet_t        next_packet;
  580.     uint8_t *       data;
  581.     size_t          fragments;
  582.     size_t *        lengths;
  583.     size_t          index;
  584.     int             result;
  585.  
  586.     // find the socket
  587.     socket = socket_cores_find( local_sockets, socket_id );
  588.     if( ! socket ) return ENOTSOCK;
  589.     // get the next received packet
  590.     packet_id = dyn_fifo_value( & socket->received );
  591.     if( packet_id < 0 ) return NO_DATA;
  592.     ERROR_PROPAGATE( packet_translate( udp_globals.net_phone, & packet, packet_id ));
  593.     // get udp header
  594.     data = packet_get_data( packet );
  595.     if( ! data ){
  596.         pq_release( udp_globals.net_phone, packet_id );
  597.         return NO_DATA;
  598.     }
  599.     header = ( udp_header_ref ) data;
  600.  
  601.     // set the source address port
  602.     result = packet_get_addr( packet, ( uint8_t ** ) & addr, NULL );
  603.     if( ERROR_OCCURRED( tl_set_address_port( addr, result, ntohs( header->source_port )))){
  604.         pq_release( udp_globals.net_phone, packet_id );
  605.         return ERROR_CODE;
  606.     }
  607.     * addrlen = ( size_t ) result;
  608.     // send the source address
  609.     ERROR_PROPAGATE( data_reply( addr, * addrlen ));
  610.  
  611.     next_packet = pq_next( packet );
  612.     if( ! next_packet ){
  613.         // write all if only one fragment
  614.         ERROR_PROPAGATE( data_reply( data + sizeof( udp_header_t ), packet_get_data_length( packet ) - sizeof( udp_header_t )));
  615.         // store the total length
  616.         length = packet_get_data_length( packet ) - sizeof( udp_header_t );
  617.     }else{
  618.         // count the packet fragments
  619.         fragments = 1;
  620.         next_packet = pq_next( packet );
  621.         while(( next_packet = pq_next( next_packet ))){
  622.             ++ fragments;
  623.         }
  624.         // compute and store the fragment lengths
  625.         lengths = ( size_t * ) malloc( sizeof( size_t ) * fragments + sizeof( size_t ));
  626.         if( ! lengths ) return ENOMEM;
  627.         lengths[ 0 ] = packet_get_data_length( packet ) - sizeof( udp_header_t );
  628.         lengths[ fragments ] = lengths[ 0 ];
  629.         next_packet = pq_next( packet );
  630.         for( index = 1; index < fragments; ++ index ){
  631.             lengths[ index ] = packet_get_data_length( next_packet );
  632.             lengths[ fragments ] += lengths[ index ];
  633.             next_packet = pq_next( packet );
  634.         }while( next_packet );
  635.         // write the fragment lengths
  636.         ERROR_PROPAGATE( data_reply( lengths, sizeof( int ) * ( fragments + 1 )));
  637.         // write the first fragment
  638.         ERROR_PROPAGATE( data_reply( data + sizeof( udp_header_t ), lengths[ 0 ] ));
  639.         next_packet = pq_next( packet );
  640.         // write the rest of the fragments
  641.         for( index = 1; index < fragments; ++ index ){
  642.             ERROR_PROPAGATE( data_reply( packet_get_data( next_packet ), lengths[ index ] ));
  643.             next_packet = pq_next( packet );
  644.         }while( next_packet );
  645.         // store the total length
  646.         length = lengths[ fragments ];
  647.         free( lengths );
  648.     }
  649.     // release the packet
  650.     dyn_fifo_pop( & socket->received );
  651.     pq_release( udp_globals.net_phone, packet_get_id( packet ));
  652.     // return the total length
  653.     return ( int ) length;
  654. }
  655.  
  656. int udp_release_and_return( packet_t packet, int result ){
  657.     pq_release( udp_globals.net_phone, packet_get_id( packet ));
  658.     return result;
  659. }
  660.  
  661. /** @}
  662.  */
  663.