xrdp/libxrdp/xrdp_channel.c
2020-12-23 09:59:21 +09:00

868 lines
23 KiB
C

/**
* 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
*/
#if defined(HAVE_CONFIG_H)
#include <config_ac.h>
#endif
#include "libxrdp.h"
#include "string_calls.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
#define CMD_DVC_OPEN_CHANNEL 0x10
#define CMD_DVC_DATA_FIRST 0x20
#define CMD_DVC_DATA 0x30
#define CMD_DVC_CLOSE_CHANNEL 0x40
#define CMD_DVC_CAPABILITY 0x50
#define XRDP_DRDYNVC_STATUS_CLOSED 0
#define XRDP_DRDYNVC_STATUS_OPEN_SENT 1
#define XRDP_DRDYNVC_STATUS_OPEN 2
#define XRDP_DRDYNVC_STATUS_CLOSE_SENT 3
/*****************************************************************************/
/* returns pointer or nil on error */
static struct mcs_channel_item *
xrdp_channel_get_item(struct xrdp_channel *self, int channel_id)
{
struct mcs_channel_item *channel;
if (self->mcs_layer->channel_list == NULL)
{
LOG(LOG_LEVEL_ERROR, "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 *
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;
self->drdynvc_channel_id = -1;
return self;
}
/*****************************************************************************/
/* returns error */
void
xrdp_channel_delete(struct xrdp_channel *self)
{
if (self == 0)
{
return;
}
free_stream(self->s);
g_memset(self, 0, sizeof(struct xrdp_channel));
g_free(self);
}
/*****************************************************************************/
/* returns error */
int
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
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)
{
LOG(LOG_LEVEL_ERROR, "xrdp_channel_send - no such channel");
return 1;
}
if (channel->disabled)
{
LOG(LOG_LEVEL_WARNING, "xrdp_channel_send, channel disabled");
return 0; /* not an error */
}
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)
{
LOG(LOG_LEVEL_ERROR, "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
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
{
LOG(LOG_LEVEL_TRACE, "in xrdp_channel_call_callback, session->callback is nil");
}
}
else
{
LOG(LOG_LEVEL_TRACE, "in xrdp_channel_call_callback, session is nil");
}
return rv;
}
/*****************************************************************************/
static int
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;
}
/*****************************************************************************/
static int
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)
{
if (!s_check_rem(s, 1))
{
return 1;
}
in_uint8(s, chan_id);
}
else if (cbChId == 1)
{
if (!s_check_rem(s, 2))
{
return 1;
}
in_uint16_le(s, chan_id);
}
else
{
if (!s_check_rem(s, 4))
{
return 1;
}
in_uint32_le(s, chan_id);
}
*chan_id_p = chan_id;
return 0;
}
/*****************************************************************************/
static int
drdynvc_process_capability_response(struct xrdp_channel *self,
int cmd, struct stream *s)
{
struct xrdp_session *session;
int cap_version;
int rv;
/* skip padding */
in_uint8s(s, 1);
/* read client's version */
in_uint16_le(s, cap_version);
if ((cap_version != 2) && (cap_version != 3))
{
LOG(LOG_LEVEL_ERROR, "drdynvc_process_capability_response: incompatible DVC "
"version %d detected", cap_version);
return 1;
}
LOG(LOG_LEVEL_INFO, "drdynvc_process_capability_response: DVC version %d selected",
cap_version);
self->drdynvc_state = 1;
session = self->sec_layer->rdp_layer->session;
rv = session->callback(session->id, 0x5558, 0, 0, 0, 0);
return rv;
}
/*****************************************************************************/
static int
drdynvc_process_open_channel_response(struct xrdp_channel *self,
int cmd, struct stream *s)
{
struct xrdp_session *session;
int creation_status;
uint32_t chan_id;
struct xrdp_drdynvc *drdynvc;
if (drdynvc_get_chan_id(s, cmd, &chan_id) != 0)
{
return 1;
}
if (!s_check_rem(s, 4))
{
return 1;
}
in_uint32_le(s, creation_status);
LOG_DEVEL(LOG_LEVEL_TRACE, "drdynvc_process_open_channel_response: chan_id 0x%x "
"creation_status %d", chan_id, creation_status);
session = self->sec_layer->rdp_layer->session;
if (chan_id > 255)
{
return 1;
}
drdynvc = self->drdynvcs + chan_id;
if (creation_status == 0)
{
drdynvc->status = XRDP_DRDYNVC_STATUS_OPEN;
}
else
{
drdynvc->status = XRDP_DRDYNVC_STATUS_CLOSED;
}
if (drdynvc->open_response != NULL)
{
return drdynvc->open_response(session->id, chan_id, creation_status);
}
return 0;
}
/*****************************************************************************/
static int
drdynvc_process_close_channel_response(struct xrdp_channel *self,
int cmd, struct stream *s)
{
struct xrdp_session *session;
uint32_t chan_id;
struct xrdp_drdynvc *drdynvc;
if (drdynvc_get_chan_id(s, cmd, &chan_id) != 0)
{
return 1;
}
LOG_DEVEL(LOG_LEVEL_TRACE, "drdynvc_process_close_channel_response: chan_id 0x%x", chan_id);
session = self->sec_layer->rdp_layer->session;
if (chan_id > 255)
{
return 1;
}
drdynvc = self->drdynvcs + chan_id;
drdynvc->status = XRDP_DRDYNVC_STATUS_CLOSED;
if (drdynvc->close_response != NULL)
{
return drdynvc->close_response(session->id, chan_id);
}
return 0;
}
/*****************************************************************************/
static int
drdynvc_process_data_first(struct xrdp_channel *self,
int cmd, struct stream *s)
{
struct xrdp_session *session;
uint32_t chan_id;
int len;
int bytes;
int total_bytes;
struct xrdp_drdynvc *drdynvc;
if (drdynvc_get_chan_id(s, cmd, &chan_id) != 0)
{
return 1;
}
len = (cmd >> 2) & 0x03;
if (len == 0)
{
if (!s_check_rem(s, 1))
{
return 1;
}
in_uint8(s, total_bytes);
}
else if (len == 1)
{
if (!s_check_rem(s, 2))
{
return 1;
}
in_uint16_le(s, total_bytes);
}
else
{
if (!s_check_rem(s, 4))
{
return 1;
}
in_uint32_le(s, total_bytes);
}
bytes = (int) (s->end - s->p);
LOG_DEVEL(LOG_LEVEL_TRACE, "drdynvc_process_data_first: bytes %d total_bytes %d", bytes, total_bytes);
session = self->sec_layer->rdp_layer->session;
if (chan_id > 255)
{
return 1;
}
drdynvc = self->drdynvcs + chan_id;
if (drdynvc->data_first != NULL)
{
return drdynvc->data_first(session->id, chan_id, s->p,
bytes, total_bytes);
}
return 0;
}
/*****************************************************************************/
static int
drdynvc_process_data(struct xrdp_channel *self,
int cmd, struct stream *s)
{
struct xrdp_session *session;
uint32_t chan_id;
int bytes;
struct xrdp_drdynvc *drdynvc;
if (drdynvc_get_chan_id(s, cmd, &chan_id) != 0)
{
return 1;
}
bytes = (int) (s->end - s->p);
LOG_DEVEL(LOG_LEVEL_TRACE, "drdynvc_process_data: bytes %d", bytes);
session = self->sec_layer->rdp_layer->session;
if (chan_id > 255)
{
return 1;
}
drdynvc = self->drdynvcs + chan_id;
if (drdynvc->data != NULL)
{
return drdynvc->data(session->id, chan_id, s->p, bytes);
}
return 0;
}
/*****************************************************************************/
static int
xrdp_channel_process_drdynvc(struct xrdp_channel *self,
struct mcs_channel_item *channel,
struct stream *s)
{
int total_length;
int length;
int flags;
int cmd;
int rv;
struct stream *ls;
if (!s_check_rem(s, 8))
{
return 1;
}
in_uint32_le(s, total_length);
in_uint32_le(s, flags);
LOG_DEVEL(LOG_LEVEL_TRACE, "xrdp_channel_process_drdynvc: total_length %d flags 0x%8.8x",
total_length, flags);
ls = NULL;
switch (flags & 3)
{
case 0:
length = (int) (s->end - s->p);
if (!s_check_rem_out(self->s, length))
{
return 1;
}
out_uint8a(self->s, s->p, length);
in_uint8s(s, length);
return 0;
case 1:
free_stream(self->s);
make_stream(self->s);
init_stream(self->s, total_length);
length = (int) (s->end - s->p);
if (!s_check_rem_out(self->s, length))
{
return 1;
}
out_uint8a(self->s, s->p, length);
in_uint8s(s, length);
return 0;
case 2:
length = (int) (s->end - s->p);
if (!s_check_rem_out(self->s, length))
{
return 1;
}
out_uint8a(self->s, s->p, length);
in_uint8s(s, length);
ls = self->s;
break;
case 3:
ls = s;
break;
default:
LOG(LOG_LEVEL_ERROR, "xrdp_channel_process_drdynvc: error");
return 1;
}
if (ls == NULL)
{
return 1;
}
in_uint8(ls, cmd); /* read command */
LOG_DEVEL(LOG_LEVEL_TRACE, "xrdp_channel_process_drdynvc: cmd 0x%x", cmd);
rv = 1;
switch (cmd & 0xf0)
{
case CMD_DVC_CAPABILITY:
rv = drdynvc_process_capability_response(self, cmd, s);
break;
case CMD_DVC_OPEN_CHANNEL:
rv = drdynvc_process_open_channel_response(self, cmd, s);
break;
case CMD_DVC_CLOSE_CHANNEL:
rv = drdynvc_process_close_channel_response(self, cmd, s);
break;
case CMD_DVC_DATA_FIRST:
rv = drdynvc_process_data_first(self, cmd, s);
break;
case CMD_DVC_DATA:
rv = drdynvc_process_data(self, cmd, s);
break;
default:
LOG_DEVEL(LOG_LEVEL_TRACE, "xrdp_channel_process_drdynvc: got unknown "
"command 0x%x", cmd);
break;
}
LOG_DEVEL(LOG_LEVEL_TRACE, "xrdp_channel_process_drdynvc: rv %d", rv);
return rv;
}
/*****************************************************************************/
/* returns error */
/* This is called from the secure layer to process an incoming non global
channel packet.
'chanid' passed in here is the mcs channel id so it MCS_GLOBAL_CHANNEL
plus something. */
int
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)
{
LOG(LOG_LEVEL_ERROR, "xrdp_channel_process, channel not found");
return 1;
}
if (channel->disabled)
{
LOG(LOG_LEVEL_WARNING, "xrdp_channel_process, channel disabled");
return 0; /* not an error */
}
if (channel_id == self->drdynvc_channel_id)
{
return xrdp_channel_process_drdynvc(self, channel, s);
}
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;
}
/*****************************************************************************/
/* drdynvc */
static int
xrdp_channel_drdynvc_send_capability_request(struct xrdp_channel *self)
{
struct stream *s;
int flags;
int total_data_len;
int channel_id;
char *phold;
/* setup stream */
make_stream(s);
init_stream(s, 8192);
if (xrdp_channel_init(self, s) != 0)
{
free_stream(s);
return 1;
}
phold = s->p;
out_uint8(s, 0x50); /* insert cmd */
out_uint8(s, 0x00); /* insert padding */
out_uint16_le(s, 2); /* 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 */
s_mark_end(s);
/* send command to client */
total_data_len = (int) (s->end - phold);
flags = CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST;
channel_id = self->drdynvc_channel_id;
if (xrdp_channel_send(self, s, channel_id, total_data_len, flags) != 0)
{
free_stream(s);
return 1;
}
free_stream(s);
return 0;
}
/*****************************************************************************/
int
xrdp_channel_drdynvc_start(struct xrdp_channel *self)
{
int index;
int count;
struct mcs_channel_item *ci;
struct mcs_channel_item *dci;
LOG_DEVEL(LOG_LEVEL_TRACE, "xrdp_channel_drdynvc_start:");
dci = NULL;
count = self->mcs_layer->channel_list->count;
for (index = 0; index < count; index++)
{
ci = (struct mcs_channel_item *)
list_get_item(self->mcs_layer->channel_list, index);
if (ci != NULL)
{
if (g_strcasecmp(ci->name, "drdynvc") == 0)
{
dci = ci;
}
}
}
if (dci != NULL)
{
self->drdynvc_channel_id = (dci->chanid - MCS_GLOBAL_CHANNEL) - 1;
xrdp_channel_drdynvc_send_capability_request(self);
}
return 0;
}
/*****************************************************************************/
int
xrdp_channel_drdynvc_open(struct xrdp_channel *self, const char *name,
int flags, struct xrdp_drdynvc_procs *procs,
int *chan_id)
{
struct stream *s;
int ChId;
int cbChId;
int chan_pri;
int static_channel_id;
int name_length;
int total_data_len;
int static_flags;
char *cmd_ptr;
make_stream(s);
init_stream(s, 8192);
if (xrdp_channel_init(self, s) != 0)
{
free_stream(s);
return 1;
}
cmd_ptr = s->p;
out_uint8(s, 0);
ChId = 1;
while (self->drdynvcs[ChId].status != XRDP_DRDYNVC_STATUS_CLOSED)
{
ChId++;
if (ChId > 255)
{
free_stream(s);
return 1;
}
}
cbChId = drdynvc_insert_uint_124(s, ChId);
name_length = g_strlen(name);
out_uint8a(s, name, name_length + 1);
chan_pri = 0;
cmd_ptr[0] = CMD_DVC_OPEN_CHANNEL | ((chan_pri << 2) & 0x0c) | cbChId;
static_channel_id = self->drdynvc_channel_id;
static_flags = CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST;
s_mark_end(s);
total_data_len = (int) (s->end - cmd_ptr);
if (xrdp_channel_send(self, s, static_channel_id, total_data_len,
static_flags) != 0)
{
free_stream(s);
return 1;
}
free_stream(s);
*chan_id = ChId;
self->drdynvcs[ChId].open_response = procs->open_response;
self->drdynvcs[ChId].close_response = procs->close_response;
self->drdynvcs[ChId].data_first = procs->data_first;
self->drdynvcs[ChId].data = procs->data;
self->drdynvcs[ChId].status = XRDP_DRDYNVC_STATUS_OPEN_SENT;
return 0;
}
/*****************************************************************************/
int
xrdp_channel_drdynvc_close(struct xrdp_channel *self, int chan_id)
{
struct stream *s;
int ChId;
int cbChId;
int static_channel_id;
int total_data_len;
int static_flags;
char *cmd_ptr;
if ((chan_id < 0) || (chan_id > 255))
{
return 1;
}
if ((self->drdynvcs[chan_id].status != XRDP_DRDYNVC_STATUS_OPEN) &&
(self->drdynvcs[chan_id].status != XRDP_DRDYNVC_STATUS_OPEN_SENT))
{
/* not open */
return 1;
}
make_stream(s);
init_stream(s, 8192);
if (xrdp_channel_init(self, s) != 0)
{
free_stream(s);
return 1;
}
cmd_ptr = s->p;
out_uint8(s, 0);
ChId = chan_id;
cbChId = drdynvc_insert_uint_124(s, ChId);
cmd_ptr[0] = CMD_DVC_CLOSE_CHANNEL | cbChId;
static_channel_id = self->drdynvc_channel_id;
static_flags = CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST;
s_mark_end(s);
total_data_len = (int) (s->end - cmd_ptr);
if (xrdp_channel_send(self, s, static_channel_id, total_data_len,
static_flags) != 0)
{
free_stream(s);
return 1;
}
free_stream(s);
self->drdynvcs[ChId].status = XRDP_DRDYNVC_STATUS_CLOSE_SENT;
return 0;
}
/*****************************************************************************/
int
xrdp_channel_drdynvc_data_first(struct xrdp_channel *self, int chan_id,
const char *data, int data_bytes,
int total_data_bytes)
{
struct stream *s;
int ChId;
int cbChId;
int cbTotalDataSize;
int static_channel_id;
int total_data_len;
int static_flags;
char *cmd_ptr;
if ((chan_id < 0) || (chan_id > 255))
{
return 1;
}
if (self->drdynvcs[chan_id].status != XRDP_DRDYNVC_STATUS_OPEN)
{
return 1;
}
if (data_bytes > 1590)
{
return 1;
}
make_stream(s);
init_stream(s, 8192);
if (xrdp_channel_init(self, s) != 0)
{
free_stream(s);
return 1;
}
cmd_ptr = s->p;
out_uint8(s, 0);
ChId = chan_id;
cbChId = drdynvc_insert_uint_124(s, ChId);
cbTotalDataSize = drdynvc_insert_uint_124(s, total_data_bytes);
out_uint8p(s, data, data_bytes);
cmd_ptr[0] = CMD_DVC_DATA_FIRST | (cbTotalDataSize << 2) | cbChId;
static_channel_id = self->drdynvc_channel_id;
static_flags = CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST;
s_mark_end(s);
total_data_len = (int) (s->end - cmd_ptr);
if (xrdp_channel_send(self, s, static_channel_id, total_data_len,
static_flags) != 0)
{
free_stream(s);
return 1;
}
free_stream(s);
return 0;
}
/*****************************************************************************/
int
xrdp_channel_drdynvc_data(struct xrdp_channel *self, int chan_id,
const char *data, int data_bytes)
{
struct stream *s;
int ChId;
int cbChId;
int static_channel_id;
int total_data_len;
int static_flags;
char *cmd_ptr;
if ((chan_id < 0) || (chan_id > 255))
{
return 1;
}
if (self->drdynvcs[chan_id].status != XRDP_DRDYNVC_STATUS_OPEN)
{
return 1;
}
if (data_bytes > 1590)
{
return 1;
}
make_stream(s);
init_stream(s, 8192);
if (xrdp_channel_init(self, s) != 0)
{
free_stream(s);
return 1;
}
cmd_ptr = s->p;
out_uint8(s, 0);
ChId = chan_id;
cbChId = drdynvc_insert_uint_124(s, ChId);
out_uint8p(s, data, data_bytes);
cmd_ptr[0] = CMD_DVC_DATA | cbChId;
static_channel_id = self->drdynvc_channel_id;
static_flags = CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST;
s_mark_end(s);
total_data_len = (int) (s->end - cmd_ptr);
if (xrdp_channel_send(self, s, static_channel_id, total_data_len,
static_flags) != 0)
{
free_stream(s);
return 1;
}
free_stream(s);
return 0;
}