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/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2006-2013
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* channel layer
*/
#include "libxrdp.h"
/* todo, move these to constants.h */
//#define CHANNEL_CHUNK_LENGTH 1600 /* todo, why is this so small? */
#define CHANNEL_CHUNK_LENGTH 8192
#define CHANNEL_FLAG_FIRST 0x01
#define CHANNEL_FLAG_LAST 0x02
#define CHANNEL_FLAG_SHOW_PROTOCOL 0x10
/*****************************************************************************/
/* returns pointer or nil on error */
static struct mcs_channel_item *APP_CC
xrdp_channel_get_item(struct xrdp_channel *self, int channel_id)
{
struct mcs_channel_item *channel;
if (self->mcs_layer->channel_list == NULL)
{
g_writeln("xrdp_channel_get_item - No channel initialized");
return NULL ;
}
channel = (struct mcs_channel_item *)
list_get_item(self->mcs_layer->channel_list, channel_id);
return channel;
}
/*****************************************************************************/
struct xrdp_channel *APP_CC
xrdp_channel_create(struct xrdp_sec *owner, struct xrdp_mcs *mcs_layer)
{
struct xrdp_channel *self;
self = (struct xrdp_channel *)g_malloc(sizeof(struct xrdp_channel), 1);
self->sec_layer = owner;
self->mcs_layer = mcs_layer;
return self;
}
/*****************************************************************************/
/* returns error */
void APP_CC
xrdp_channel_delete(struct xrdp_channel *self)
{
if (self == 0)
{
return;
}
g_memset(self, 0, sizeof(struct xrdp_channel));
g_free(self);
}
/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_channel_init(struct xrdp_channel *self, struct stream *s)
{
if (xrdp_sec_init(self->sec_layer, s) != 0)
{
return 1;
}
s_push_layer(s, channel_hdr, 8);
return 0;
}
/*****************************************************************************/
/* returns error */
/* This sends data out to the secure layer. */
int APP_CC
xrdp_channel_send(struct xrdp_channel *self, struct stream *s, int channel_id,
int total_data_len, int flags)
{
struct mcs_channel_item *channel;
channel = xrdp_channel_get_item(self, channel_id);
if (channel == NULL)
{
g_writeln("xrdp_channel_send - no such channel");
return 1;
}
s_pop_layer(s, channel_hdr);
out_uint32_le(s, total_data_len);
/*
* According to 2.2.1.3.4.1 Channel Definition Structure (CHANNEL_DEF):
* CHANNEL_OPTION_SHOW_PROTOCOL 0x00200000
* The value of this flag MUST be ignored by the server. The
* visibility of the Channel PDU Header (section 2.2.6.1.1) is
* determined by the CHANNEL_FLAG_SHOW_PROTOCOL
* (0x00000010) flag as defined in the flags field (section
* 2.2.6.1.1).
*
* That's flag makes MSTSC crash when using RAIL channel.
*/
// if (channel->flags & XR_CHANNEL_OPTION_SHOW_PROTOCOL)
// {
// flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
// }
out_uint32_le(s, flags);
if (xrdp_sec_send(self->sec_layer, s, channel->chanid) != 0)
{
g_writeln("xrdp_channel_send - failure sending data");
return 1;
}
return 0;
}
/*****************************************************************************/
/* returns error */
/* this will inform the callback, whatever it is that some channel data is
ready. the default for this is a call to xrdp_wm.c. */
static int APP_CC
xrdp_channel_call_callback(struct xrdp_channel *self, struct stream *s,
int channel_id,
int total_data_len, int flags)
{
struct xrdp_session *session;
int rv;
int size;
rv = 0;
session = self->sec_layer->rdp_layer->session;
if (session != 0)
{
if (session->callback != 0)
{
size = (int)(s->end - s->p);
/* in xrdp_wm.c */
rv = session->callback(session->id, 0x5555,
MAKELONG(channel_id, flags),
size, (tbus)(s->p), total_data_len);
}
else
{
g_writeln("in xrdp_channel_call_callback, session->callback is nil");
}
}
else
{
g_writeln("in xrdp_channel_call_callback, session is nil");
}
return rv;
}
/*****************************************************************************/
/* returns error */
/* This is called from the secure layer to process an incomming non global
channel packet.
'chanid' passed in here is the mcs channel id so it MCS_GLOBAL_CHANNEL
plus something. */
int APP_CC
xrdp_channel_process(struct xrdp_channel *self, struct stream *s,
int chanid)
{
int length;
int flags;
int rv;
int channel_id;
struct mcs_channel_item *channel;
/* this assumes that the channels are in order of chanid(mcs channel id)
but they should be, see xrdp_sec_process_mcs_data_channels
the first channel should be MCS_GLOBAL_CHANNEL + 1, second
one should be MCS_GLOBAL_CHANNEL + 2, and so on */
channel_id = (chanid - MCS_GLOBAL_CHANNEL) - 1;
channel = xrdp_channel_get_item(self, channel_id);
if (channel == NULL)
{
g_writeln("xrdp_channel_process, channel not found");
return 1;
}
rv = 0;
in_uint32_le(s, length);
in_uint32_le(s, flags);
rv = xrdp_channel_call_callback(self, s, channel_id, length, flags);
return rv;
}
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