added channel support

1 files changed, 239 insertions, 0 deletions

diff --git a/libxrdp/xrdp_channel.c b/libxrdp/xrdp_channel.c
new file mode 100644
index 00000000..f5ddfef3
--- /dev/null
+++ b/libxrdp/xrdp_channel.c
@@ -0,0 +1,239 @@
+/*
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   xrdp: A Remote Desktop Protocol server.
+   Copyright (C) Jay Sorg 2006
+
+   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;
+
+  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_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, breaking up the data to
+   CHANNEL_CHUNK_LENGTH as needed.  This can end up sending many packets. */
+int APP_CC
+xrdp_channel_send(struct xrdp_channel* self, struct stream* s, int channel_id)
+{
+  int length;
+  int flags;
+  int thislength;
+  int remaining;
+  char* data;
+  struct mcs_channel_item* channel;
+
+  channel = xrdp_channel_get_item(self, channel_id);
+  if (channel == 0)
+  {
+    return 1;
+  }
+  s_pop_layer(s, channel_hdr);
+  length = (int)((s->end - s->p) - 8);
+  thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
+  remaining = length - thislength;
+  flags = (remaining == 0) ?
+          CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST;
+  if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+  {
+    flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+  }
+  out_uint32_le(s, length);
+  out_uint32_le(s, flags);
+  s->end = s->p + thislength;
+  data = s->end;
+  if (xrdp_sec_send(self->sec_layer, s, channel->chanid) != 0)
+  {
+    return 1;
+  }
+  while (remaining > 0)
+  {
+    thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH);
+    remaining -= thislength;
+    flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0;
+    if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+    {
+      flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+    }
+    if (xrdp_sec_init(self->sec_layer, s) != 0)
+    {
+      return 1;
+    }
+    out_uint32_le(s, length);
+    out_uint32_le(s, flags);
+    /* this is copying a later part of the stream up to the front */
+    out_uint8a(s, data, thislength);
+    s_mark_end(s);
+    if (xrdp_sec_send(self->sec_layer, s, channel->chanid) != 0)
+    {
+      return 1;
+    }
+    data += thislength;
+  }
+  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)
+{
+  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, channel_id, size,
+                             (long)s->p, 0);
+    }
+    else
+    {
+      g_writeln("in xrdp_channel_process1, session->callback is nil");
+    }
+  }
+  else
+  {
+    g_writeln("in xrdp_channel_process1, session is nil");
+  }
+  return rv;
+}
+
+/*****************************************************************************/
+/* returns error */
+/* This is called from the secure layer to process an incomming non global
+   channel packet.  It copies the channel data to a special stream contained
+   in the channel struct(the one in xrdp_mcs->channel_list) untill the
+   whole data message is ready.
+   '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 thislength;
+  int rv;
+  int channel_id;
+  struct stream* in_s;
+  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 == 0)
+  {
+    g_writeln("xrdp_channel_process, channel not found");
+    return 1;
+  }
+  rv = 0;
+  in_uint32_le(s, length);
+  in_uint32_le(s, flags);
+  if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST))
+  {
+    rv = xrdp_channel_call_callback(self, s, channel_id);
+  }
+  else
+  {
+    if (channel->in_s == 0)
+    {
+      make_stream(channel->in_s);
+    }
+    in_s = channel->in_s;
+    if (flags & CHANNEL_FLAG_FIRST)
+    {
+      init_stream(in_s, length);
+    }
+    thislength = MIN(s->end - s->p, (in_s->data + in_s->size) - in_s->p);
+    out_uint8a(in_s, s->p, thislength);
+    if (flags & CHANNEL_FLAG_LAST)
+    {
+      in_s->end = in_s->p;
+      in_s->p = in_s->data;
+      rv = xrdp_channel_call_callback(self, in_s, channel_id);
+    }
+  }
+  return rv;
+}