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* Copyright (c) 2004, Jeroen Asselman
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*----------------------------------------------------------------------
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* This file is part of gtk-gnutella.
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* gtk-gnutella is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* gtk-gnutella is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with gtk-gnutella; if not, write to the Free Software
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*----------------------------------------------------------------------
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* Needs short description here.
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* @author Jeroen Asselman
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#include "../common.h" /* For -DUSE_DMALLOC */
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int sequencenumber = 0;
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static int header_length = 8;
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static int MTU = 1500;
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int transmit_retransmit_interval = 10; /**< seconds */
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int transmit_packet_timeout = 26; /**< seconds */
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int receive_packet_expiry = 30; /**< seconds */
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GSList *receiving_fragments_list;
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GSList *received_fragments_list;
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typedef struct fragment_s fragment_t;
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time_t initial_transmitted;
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time_t last_transmitted;
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void udp_transceiver_timer(time_t now)
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/* Fragments waiting for acknowledge > receive_packet_expiry?
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* Remove acknowledge packets.
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* Fragments waiting for acknowledge?
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* Retransmit to be acknowledged packets
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* Fragments to be send?
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* Send a few fragments. No more then udp_bandwith_out / MTU
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*** Building and sending
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* Wether the udp transceiver might be able to handle this received fragment.
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udp_transceiver_can_handle_received_fragment(char *buf, int length)
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return length > header_length &&
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buf[0] == 'G' && buf[1] == 'N' && buf[2] == 'D';
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* Put fragment in the to send list.
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udp_transceiver_put_send_fragment(fragment_t *fragment)
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/* FIXME: glist_prepend fragment */
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udp_transceiver_send_fragment(fragment_t *fragment,
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gboolean acknowledge)
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/* FIXME: Send fragment over socket. */
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/* FIXME: Add fragment to waiting_for_acknowledge list */
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* Free the fragment and all its associated memory.
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udp_transceiver_free_fragment(fragment_t *fragment)
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if (fragment->fragment != NULL)
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free(fragment->fragment);
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udp_transceiver_build_fragment(char *buffer, int length,
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gboolean acknowledge)
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fragment_t *fragment = (fragment_t *) malloc(sizeof(fragment_t));
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fragment->fragment_length = length + header_length;
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fragment->fragment = (char *) malloc(fragment->fragment_length);
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/* Build identifier */
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fragment->fragment[0] = 'G';
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fragment->fragment[1] = 'N';
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fragment->fragment[2] = 'D';
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/* Endian doesn't matter */
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fragment->fragment[4] = (sequencenumber & 0x00FF);
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fragment->fragment[5] = (sequencenumber >> 8);
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fragment->fragment[6] = partnumber;
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fragment->fragment[7] = fragments;
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memcpy(fragment->fragment + header_length, buffer, length);
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* Send a fragment to the specified address.
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udp_transceiver_send(char *buffer, int length, gboolean deflate,
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gboolean acknowledge,
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guint32 address, guint16 port)
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/* Create fragments. */
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int fragments = (int) ceil((double)length / (double) MTU);
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for (i = 0; i < fragments; i++) {
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fragment_t *fragment = udp_transceiver_build_fragment(
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buffer + offset, length - offset > MTU ? MTU : length - offset,
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sequencenumber, i, fragments, deflate, acknowledge);
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fragment->ipaddress = address;
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fragment->port = port;
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udp_transceiver_send_fragment(fragment, deflate, acknowledge);
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*** Receiving and parsing
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* Get the sequence number from a fragment.
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udp_transceiver_get_sequencenumber(fragment_t *fragment)
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return (fragment->fragment[4] << 8) + fragment->fragment[5];
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* Get the part number from a fragment.
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udp_transceiver_get_partnumber(fragment_t *fragment)
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return fragment->fragment[6];
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* Get the number of fragments from a datagram fragment.
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udp_transceiver_get_fragments(fragment_t *fragment)
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return fragment->fragment[7];
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* Gets previously received fragments from the given source with matching
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udp_transceiver_lookup_fragments_by_sequencenumber_source(
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fragment_t *fragment)
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* Puts a received datagram fragment in a to handle list.
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udp_transceiver_put_received_fragment(fragment_t *fragment)
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int fragments = udp_transceiver_get_fragments(fragment);
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int partnumber = udp_transceiver_get_partnumber(fragment);
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int sequencenumber = udp_transceiver_get_sequencenumber(fragment);
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GSList *fragment_list =
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udp_transceiver_lookup_fragments_by_sequencenumber_source(
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fragment_t *fragment_tmp;
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if (fragment_list == NULL)
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/* FIXME: Create new fragment list (array?) with size fragments */
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/* fragment_tmp = gslist_at(fragment_list, partnumber) */
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if (fragment_tmp == NULL)
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* gslist_insert_at(fragment_list, partnumber, fragment_received) */
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/* FIXME: udp_transceiver_free_fragment(fragment) */
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/* FIXME: Check if all fragments are received */
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/* All fragments received */
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* Parses a datagram and if it is a fragment it will be handed over to
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* udp_transceiver_put_received_fragment.
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udp_transceiver_put_received_datagram(char *buf, int length,
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guint32 ip, guint16 port)
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fragment_t *fragment_received;
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if (!udp_transceiver_can_handle_received_fragment(buf, length))
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fragment_received = (fragment_t *) malloc(sizeof(fragment_t));
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fragment_received->fragment = (char *) malloc(length);
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memcpy(fragment_received->fragment, buf, length);
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fragment_received->fragment_length = length;
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fragment_received->ipaddress = ip;
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fragment_received->port = port;
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udp_transceiver_put_received_fragment(fragment_received);
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* Handle receiving of data
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udp_transceiver_receive(char **buffer, int *length)
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/* FIXME: for bla in fragments_received */
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/* *length += fragment->fragment_length - header_length */
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/* vi: set ts=4 sw=4 cindent: */
added
removed
src/g2/udp_transceiver.c
