xrdp/sesman/chansrv/drdynvc.c

528 lines
13 KiB
C

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Laxmikant Rashinkar 2012 LK.Rashinkar@gmail.com
*
* 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.
*/
#include "drdynvc.h"
extern int g_drdynvc_chan_id; /* in chansrv.c */
int g_drdynvc_inited = 0;
static int APP_CC drdynvc_send_capability_request(uint16_t version);
static int APP_CC drdynvc_process_capability_response(struct stream* s, unsigned char cmd);
static int APP_CC drdynvc_process_open_channel_response(struct stream *s, unsigned char cmd);
static int APP_CC drdynvc_process_close_channel_response(struct stream *s, unsigned char cmd);
static int APP_CC drdynvc_process_data_first(struct stream* s, unsigned char cmd);
static int APP_CC drdynvc_process_data(struct stream* s, unsigned char cmd);
static int APP_CC drdynvc_insert_uint_124(struct stream *s, uint32_t val);
static int APP_CC drdynvc_get_chan_id(struct stream *s, char cmd, uint32_t *chan_id_p);
/**
* bring up dynamic virtual channel
*
* @return 0 on success, -1 on response
******************************************************************************/
int APP_CC
drdynvc_init(void)
{
/* bring up X11 */
xcommon_init();
/* let client know what version of DVC we support */
drdynvc_send_capability_request(2);
return 0;
}
/**
* let DVC Manager on client end know what version of protocol we support
* client will respond with version that it supports
*
* @return 0 on success, -1 on response
******************************************************************************/
static int APP_CC
drdynvc_send_capability_request(uint16_t version)
{
struct stream *s;
int bytes_in_stream;
/* setup stream */
make_stream(s);
init_stream(s, MAX_PDU_SIZE);
out_uint8(s, 0x50); /* insert cmd */
out_uint8(s, 0x00); /* insert padding */
out_uint16_le(s, version); /* insert version */
/* channel priority unused for now */
out_uint16_le(s, 0x0000); /* priority charge 0 */
out_uint16_le(s, 0x0000); /* priority charge 1 */
out_uint16_le(s, 0x0000); /* priority charge 2 */
out_uint16_le(s, 0x0000); /* priority charge 3 */
/* send command to client */
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
free_stream(s);
return 0;
}
/**
* process capability response received from DVC manager at client end
*
* @param s stream containing client response
*
* @return 0 on success, -1 on failure
******************************************************************************/
static int APP_CC
drdynvc_process_capability_response(struct stream *s, unsigned char cmd)
{
int cap_version;
/* skip padding */
in_uint8s(s, 1);
/* read client's version */
in_uint16_le(s, cap_version);
if ((cap_version != 2) && (cap_version != 3))
{
LOG(0, ("drdynvc_process_capability_response: incompatible DVC "
"version %d detected", cap_version));
return -1;
}
LOG(0, ("drdynvc_process_capability_response: DVC version %d selected",
cap_version));
g_drdynvc_inited = 1;
return 0;
}
/**
* create a new dynamic virtual channel
*
* @pram channel_id channel id number
* @pram channel_name name of channel
*
* @return 0 on success, -1 on failure
******************************************************************************/
int APP_CC
drdynvc_send_open_channel_request(int chan_pri, unsigned int chan_id,
char *chan_name)
{
struct stream *s;
int bytes_in_stream;
int cbChId;
int name_length;
if ((chan_name == NULL) || (strlen(chan_name) == 0))
{
LOG(0, ("drdynvc_send_open_channel_request: bad channel name specified"));
return -1;
}
make_stream(s);
init_stream(s, MAX_PDU_SIZE);
name_length = strlen(chan_name);
/* dummy command for now */
out_uint8(s, 0);
/* insert channel id */
cbChId = drdynvc_insert_uint_124(s, chan_id);
/* insert channel name */
out_uint8a(s, chan_name, name_length + 1);
/* insert command */
s->data[0] = CMD_DVC_OPEN_CHANNEL | ((chan_pri << 2) & 0x0c) | cbChId;
/* send command */
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
free_stream(s);
return 0;
}
static int APP_CC
drdynvc_process_open_channel_response(struct stream *s, unsigned char cmd)
{
struct xrdp_api_data *adp;
uint32_t chan_id;
int creation_status;
drdynvc_get_chan_id(s, cmd, &chan_id);
in_uint32_le(s, creation_status);
/* LK_TODO now do something using useful! */
if (creation_status < 0)
{
// TODO
}
else
{
/* get struct xrdp_api_data containing this channel id */
if ((adp = struct_from_dvc_chan_id(chan_id)) == NULL)
{
LOG(0, ("drdynvc_process_open_channel_response: error : "
"could not find xrdp_api_data containing chan_id %d", chan_id));
return -1;
}
adp->is_connected = 1;
}
return 0;
}
int APP_CC
drdynvc_send_close_channel_request(unsigned int chan_id)
{
struct stream *s;
int bytes_in_stream;
int cbChId;
make_stream(s);
init_stream(s, MAX_PDU_SIZE);
/* insert dummy cmd for now */
out_uint8(s, 0);
/* insert channel id */
cbChId = drdynvc_insert_uint_124(s, chan_id);
/* insert command */
s->data[0] = CMD_DVC_CLOSE_CHANNEL | cbChId;
/* send command */
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
free_stream(s);
return 0;
}
static int APP_CC
drdynvc_process_close_channel_response(struct stream *s, unsigned char cmd)
{
uint32_t chan_id;
drdynvc_get_chan_id(s, cmd, &chan_id);
/* LK_TODO now do something using useful! */
return 0;
}
/*
* send data to client
*
* @param chan_id the virtual channel to write to
* @param data data to write
* @param data_size number of bytes to write
*
* @return 0 on success, -1 on failure
******************************************************************************/
int APP_CC drdynvc_write_data(uint32_t chan_id, char *data, int data_size)
{
struct stream *s;
char *saved_ptr;
int cbChId;
int Len;
int bytes_in_stream;
int frag_size;
if (data == NULL)
{
LOG(0, ("drdynvc_write_data: data is NULL\n"));
return -1;
}
if (data_size <= 0)
{
return 0;
}
make_stream(s);
init_stream(s, MAX_PDU_SIZE);
/* this is a dummy write */
out_uint8(s, 0);
/* insert channel id */
cbChId = drdynvc_insert_uint_124(s, chan_id);
/* will data fit into one pkt? */
bytes_in_stream = stream_length_before_p(s);
if ((bytes_in_stream + data_size) <= MAX_PDU_SIZE)
{
/* yes it will - insert data */
out_uint8p(s, data, data_size);
/* insert command */
s->data[0] = CMD_DVC_DATA | cbChId;
/* write data to client */
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
free_stream(s);
return 0;
}
/* no it won't - fragment it */
saved_ptr = s->p;
/* let client know how much data to expect */
Len = drdynvc_insert_uint_124(s, data_size);
/* insert data into first fragment */
frag_size = MAX_PDU_SIZE - stream_length_before_p(s);
out_uint8p(s, data, frag_size);
/* insert command */
s->data[0] = CMD_DVC_DATA_FIRST | Len << 2 | cbChId;
/* write first fragment to client */
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
data_size -= frag_size;
data += frag_size;
s->data[0] = CMD_DVC_DATA | cbChId;
s->p = saved_ptr;
/* now send rest of the data using CMD_DVC_DATA */
while (data_size > 0)
{
frag_size = MAX_PDU_SIZE - stream_length_before_p(s);
if (frag_size > data_size)
{
frag_size = data_size;
}
out_uint8p(s, data, frag_size);
bytes_in_stream = stream_length_before_p(s);
send_channel_data(g_drdynvc_chan_id, s->data, bytes_in_stream);
data_size -= frag_size;
data += frag_size;
s->p = saved_ptr;
}
free_stream(s);
return 0;
}
static int APP_CC
drdynvc_process_data_first(struct stream *s, unsigned char cmd)
{
struct xrdp_api_data *adp;
struct stream *ls;
uint32_t chan_id;
int bytes_in_stream;
int Len;
drdynvc_get_chan_id(s, cmd, &chan_id);
Len = (cmd >> 2) & 0x03;
/* skip data_len */
if (Len == 0)
{
in_uint8s(s, 1);
}
else if (Len == 1)
{
in_uint8s(s, 2);
}
else
{
in_uint8s(s, 4);
}
bytes_in_stream = stream_length_after_p(s);
/* get struct xrdp_api_data containing this channel id */
if ((adp = struct_from_dvc_chan_id(chan_id)) == NULL)
{
LOG(0, ("drdynvc_process_data_first: error : "
"could not find xrdp_api_data containing chan_id %d", chan_id));
return -1;
}
ls = trans_get_out_s(adp->transp, MAX_PDU_SIZE);
out_uint8p(ls, s->p, bytes_in_stream);
s_mark_end(ls);
trans_force_write(adp->transp);
return 0;
}
static int APP_CC
drdynvc_process_data(struct stream *s, unsigned char cmd)
{
struct xrdp_api_data *adp;
struct stream *ls;
uint32_t chan_id;
int bytes_in_stream;
drdynvc_get_chan_id(s, cmd, &chan_id);
bytes_in_stream = stream_length_after_p(s);
/* get struct xrdp_api_data containing this channel id */
if ((adp = struct_from_dvc_chan_id(chan_id)) == NULL)
{
LOG(0, ("drdynvc_process_data: error : "
"could not find xrdp_api_data containing chan_id %d", chan_id));
return -1;
}
ls = trans_get_out_s(adp->transp, MAX_PDU_SIZE);
out_uint8p(ls, s->p, bytes_in_stream);
s_mark_end(ls);
trans_force_write(adp->transp);
return 0;
}
/**
* process incoming data on a dynamic virtual channel
*
* @pram s stream containing the incoming data
* @pram chan_id LK_TODO
* @pram chan_flags LK_TODO
* @pram length LK_TODO
* @pram total_length LK_TODO
*
* @return 0 on success, -1 on failure
******************************************************************************/
int APP_CC
drdynvc_data_in(struct stream *s, int chan_id, int chan_flags, int length,
int total_length)
{
unsigned char cmd;
in_uint8(s, cmd); /* read command */
switch (cmd & 0xf0)
{
case CMD_DVC_CAPABILITY:
drdynvc_process_capability_response(s, cmd);
break;
case CMD_DVC_OPEN_CHANNEL:
drdynvc_process_open_channel_response(s, cmd);
break;
case CMD_DVC_CLOSE_CHANNEL:
drdynvc_process_close_channel_response(s, cmd);
break;
case CMD_DVC_DATA_FIRST:
drdynvc_process_data_first(s, cmd);
break;
case CMD_DVC_DATA:
drdynvc_process_data(s, cmd);
break;
default:
LOG(0, ("drdynvc_data_in: got unknown command 0x%x", cmd));
break;
}
return 0;
}
/*
* insert a byte, short or 32bit value into specified stream
*
* @param s stream used for insertion
* @param val value to insert
*
* @return 0 for byte insertions
* @return 1 for short insertion
* @return 2 for uint32_t insertions
******************************************************************************/
static int APP_CC
drdynvc_insert_uint_124(struct stream *s, uint32_t val)
{
int ret_val;
if (val <= 0xff)
{
out_uint8(s, val);
ret_val = 0;
}
else if (val <= 0xffff)
{
out_uint16_le(s, val);
ret_val = 1;
}
else
{
out_uint32_le(s, val);
ret_val = 2;
}
return ret_val;
}
/*
* extract channel id from stream
*
* @param s stream containing channel id
* @param cmd first byte in stream
* @param chan_id return channel id here
******************************************************************************/
static int APP_CC
drdynvc_get_chan_id(struct stream *s, char cmd, uint32_t *chan_id_p)
{
int cbChId;
int chan_id;
cbChId = cmd & 0x03;
if (cbChId == 0)
{
in_uint8(s, chan_id);
}
else if (cbChId == 1)
{
in_uint16_le(s, chan_id);
}
else
{
in_uint32_le(s, chan_id);
}
*chan_id_p = chan_id;
return 0;
}