dcc.h

   1 /********************************************************************\
   2 * BitlBee -- An IRC to other IM-networks gateway                     *
   3 *                                                                    *
   4 * Copyright 2006 Marijn Kruisselbrink and others                     *
   5 * Copyright 2007 Uli Meis <a.sporto+bee@gmail.com>                   *
   6 \********************************************************************/
   7
   8 /*
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; either version 2 of the License, or
  12   (at your option) any later version.
  13
  14   This program is distributed in the hope that it will be useful,
  15   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17   GNU General Public License for more details.
  18
  19   You should have received a copy of the GNU General Public License with
  20   the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  21   if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  22   Suite 330, Boston, MA  02111-1307  USA
  23 */
  24
  25 /*
  26  * DCC SEND
  27  *
  28  * Historically, DCC means send 1024 Bytes and wait for a 4 byte reply
  29  * acknowledging all transferred data. This is ridiculous for two reasons.  The
  30  * first being that TCP is a stream oriented protocol that doesn't care much
  31  * about your idea of a packet. The second reason being that TCP is a reliable
  32  * transfer protocol with its own sophisticated ACK mechanism, making DCCs ACK
  33  * mechanism look like a joke. For these reasons, DCCs requirements have
  34  * (hopefully) been relaxed in most implementations and this implementation
  35  * depends upon at least the following: The 1024 bytes need not be transferred
  36  * at once, i.e. packets can be smaller. A second relaxation has apparently
  37  * gotten the name "DCC SEND ahead" which basically means to not give a damn
  38  * about those DCC ACKs and just send data as you please. This behaviour is
  39  * enabled by default. Note that this also means that packets may be as large
  40  * as the maximum segment size.
  41  */
  42
  43 #ifndef _DCC_H
  44 #define _DCC_H
  45
  46 /* Send an ACK after receiving this amount of data */
  47 #define DCC_PACKET_SIZE 1024
  48
  49 /* Time in seconds that a DCC transfer can be stalled before being aborted.
  50  * By handling this here individual protocols don't have to think about this. */
  51 #define DCC_MAX_STALL 120
  52
  53 typedef struct dcc_file_transfer {
  54
  55         struct im_connection *ic;
  56
  57         /*
  58          * Depending in the status of the file transfer, this is either the socket that is
  59          * being listened on for connections, or the socket over which the file transfer is
  60          * taking place.
  61          */
  62         int fd;
  63
  64         /*
  65          * IDs returned by b_input_add for watch_ing over the above socket.
  66          */
  67         gint watch_in;   /* readable */
  68         gint watch_out;  /* writable */
  69
  70         /* the progress watcher cancels any file transfer if nothing happens within DCC_MAX_STALL */
  71         gint progress_timeout;
  72         size_t progress_bytes_last;
  73
  74         /*
  75          * The total amount of bytes that have been sent to the irc client.
  76          */
  77         size_t bytes_sent;
  78
  79         /*
  80          * Handle the wonderful sadly-not-deprecated ACKs.
  81          */
  82         guint32 acked;
  83         int acked_len;
  84
  85         /* imc's handle */
  86         file_transfer_t *ft;
  87
  88         /* if we're receiving, this is the sender's socket address */
  89         struct sockaddr_storage saddr;
  90
  91         /* set to true if the protocol has finished
  92          * (i.e. called imcb_file_finished)
  93          */
  94         int proto_finished;
  95 } dcc_file_transfer_t;
  96
  97 file_transfer_t *dccs_send_start( struct im_connection *ic, irc_user_t *iu, const char *file_name, size_t file_size );
  98 void dcc_canceled( file_transfer_t *file, char *reason );
  99 gboolean dccs_send_write( file_transfer_t *file, char *data, unsigned int data_size );
 100 file_transfer_t *dcc_request( struct im_connection *ic, char* const* ctcp );
 101 void dcc_finish( file_transfer_t *file );
 102 void dcc_close( file_transfer_t *file );
 103 gboolean dccs_recv_start( file_transfer_t *ft );
 104
 105 #endif