base/applications/tsclient/rdesktop/channels.c

   1 /* -*- c-basic-offset: 8 -*-
   2    rdesktop: A Remote Desktop Protocol client.
   3    Protocol services - Virtual channels
   4    Copyright (C) Erik Forsberg <forsberg@cendio.se> 2003
   5    Copyright (C) Matthew Chapman 2003-2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "rdesktop.h"
  23
  24 // FIXME: header mess
  25 #if 0
  26 #define CHANNEL_CHUNK_LENGTH            1600
  27 #define CHANNEL_FLAG_FIRST              0x01
  28 #define CHANNEL_FLAG_LAST               0x02
  29 #define CHANNEL_FLAG_SHOW_PROTOCOL      0x10
  30 #endif
  31
  32 /* FIXME: We should use the information in TAG_SRV_CHANNELS to map RDP5
  33    channels to MCS channels.
  34
  35    The format of TAG_SRV_CHANNELS seems to be
  36
  37    global_channel_no (uint16le)
  38    number_of_other_channels (uint16le)
  39    ..followed by uint16les for the other channels.
  40 */
  41
  42 VCHANNEL *
  43 channel_register(RDPCLIENT * This, char *name, uint32 flags, void (*callback) (RDPCLIENT *, STREAM))
  44 {
  45         VCHANNEL *channel;
  46
  47         if (!This->use_rdp5)
  48                 return NULL;
  49
  50         if (This->num_channels >= MAX_CHANNELS)
  51         {
  52                 error("Channel table full, increase MAX_CHANNELS\n");
  53                 return NULL;
  54         }
  55
  56         channel = &This->channels[This->num_channels];
  57         channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + This->num_channels;
  58         strncpy(channel->name, name, 8);
  59         channel->flags = flags;
  60         channel->process = callback;
  61         This->num_channels++;
  62         return channel;
  63 }
  64
  65 STREAM
  66 channel_init(RDPCLIENT * This, VCHANNEL * channel, uint32 length)
  67 {
  68         STREAM s;
  69
  70         s = sec_init(This, This->encryption ? SEC_ENCRYPT : 0, length + 8);
  71         s_push_layer(s, channel_hdr, 8);
  72         return s;
  73 }
  74
  75 void
  76 channel_send(RDPCLIENT * This, STREAM s, VCHANNEL * channel)
  77 {
  78         uint32 length, flags;
  79         uint32 thislength, remaining;
  80         uint8 *data;
  81
  82         /* first fragment sent in-place */
  83         s_pop_layer(s, channel_hdr);
  84         length = s->end - s->p - sizeof(CHANNEL_PDU_HEADER);
  85
  86         DEBUG_CHANNEL(("channel_send, length = %d\n", length));
  87
  88         thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
  89 /* Note: In the original clipboard implementation, this number was
  90    1592, not 1600. However, I don't remember the reason and 1600 seems
  91    to work so.. This applies only to *this* length, not the length of
  92    continuation or ending packets. */
  93         remaining = length - thislength;
  94         flags = (remaining == 0) ? CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST;
  95         if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
  96                 flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
  97
  98         out_uint32_le(s, length);
  99         out_uint32_le(s, flags);
 100         data = s->end = s->p + thislength;
 101         DEBUG_CHANNEL(("Sending %d bytes with FLAG_FIRST\n", thislength));
 102         sec_send_to_channel(This, s, This->encryption ? SEC_ENCRYPT : 0, channel->mcs_id);
 103
 104         /* subsequent segments copied (otherwise would have to generate headers backwards) */
 105         while (remaining > 0)
 106         {
 107                 thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH);
 108                 remaining -= thislength;
 109                 flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0;
 110                 if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
 111                         flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
 112
 113                 DEBUG_CHANNEL(("Sending %d bytes with flags %d\n", thislength, flags));
 114
 115                 s = sec_init(This, This->encryption ? SEC_ENCRYPT : 0, thislength + 8);
 116                 out_uint32_le(s, length);
 117                 out_uint32_le(s, flags);
 118                 out_uint8p(s, data, thislength);
 119                 s_mark_end(s);
 120                 sec_send_to_channel(This, s, This->encryption ? SEC_ENCRYPT : 0, channel->mcs_id);
 121
 122                 data += thislength;
 123         }
 124 }
 125
 126 void
 127 channel_process(RDPCLIENT * This, STREAM s, uint16 mcs_channel)
 128 {
 129         uint32 length, flags;
 130         uint32 thislength;
 131         VCHANNEL *channel = NULL;
 132         unsigned int i;
 133         STREAM in;
 134
 135         for (i = 0; i < This->num_channels; i++)
 136         {
 137                 channel = &This->channels[i];
 138                 if (channel->mcs_id == mcs_channel)
 139                         break;
 140         }
 141
 142         if (i >= This->num_channels)
 143                 return;
 144
 145         in_uint32_le(s, length);
 146         in_uint32_le(s, flags);
 147         if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST))
 148         {
 149                 /* single fragment - pass straight up */
 150                 channel->process(This, s);
 151         }
 152         else
 153         {
 154                 /* add fragment to defragmentation buffer */
 155                 in = &channel->in;
 156                 if (flags & CHANNEL_FLAG_FIRST)
 157                 {
 158                         if (length > in->size)
 159                         {
 160                                 in->data = (uint8 *) xrealloc(in->data, length);
 161                                 in->size = length;
 162                         }
 163                         in->p = in->data;
 164                 }
 165
 166                 thislength = MIN(s->end - s->p, in->data + in->size - in->p);
 167                 memcpy(in->p, s->p, thislength);
 168                 in->p += thislength;
 169
 170                 if (flags & CHANNEL_FLAG_LAST)
 171                 {
 172                         in->end = in->p;
 173                         in->p = in->data;
 174                         channel->process(This, in);
 175                 }
 176         }
 177 }