Merge pull request #615 from speidy/channels_fixes

Channels improvements

common/xrdp_client_info.h

@@ -65,7 +65,7 @@ struct xrdp_client_info
   int rdp_compression;
   int rdp_autologin;
   int crypt_level; /* 1, 2, 3 = low, medium, high */
-  int channel_code; /* 0 = no channels 1 = channels */
+  int channels_allowed; /* 0 = no channels 1 = channels */
   int sound_code; /* 1 = leave sound at server */
   int is_mce;
   int rdp5_performanceflags;

libxrdp/libxrdp.c

@@ -1242,7 +1242,7 @@ libxrdp_send_to_channel(struct xrdp_session *session, int channel_id,
 
     if (xrdp_channel_send(chan, s, channel_id, total_data_len, flags) != 0)
     {
-        g_writeln("Debug - data NOT sent to channel");
+        g_writeln("libxrdp_send_to_channel: error, server channel data NOT sent to client channel");
         free_stream(s);
         return 1;
     }

libxrdp/xrdp_rdp.c

@@ -105,8 +105,8 @@ xrdp_rdp_read_config(struct xrdp_client_info *client_info)
         }
         else if (g_strcasecmp(item, "allow_channels") == 0)
         {
-            client_info->channel_code = g_text2bool(value);
-            if (client_info->channel_code == 0)
+            client_info->channels_allowed = g_text2bool(value);
+            if (client_info->channels_allowed == 0)
             {
                 log_message(LOG_LEVEL_DEBUG,"Info - All channels are disabled");
             }

libxrdp/xrdp_sec.c

@@ -1829,12 +1829,12 @@ xrdp_sec_process_mcs_data_channels(struct xrdp_sec *self, struct stream *s)
     client_info = &(self->rdp_layer->client_info);
 
 
-    DEBUG(("processing channels, channel_code is %d", client_info->channel_code));
+    DEBUG(("processing channels, channels_allowed is %d", client_info->channels_allowed));
 
     /* this is an option set in xrdp.ini */
-    if (client_info->channel_code != 1) /* are channels on? */
+    if (client_info->channels_allowed != 1) /* are channels on? */
     {
-        g_writeln("Processing channel data from client - The channel is off");
+        g_writeln("xrdp_sec_process_mcs_data_channels: all channels are disabled by configuration");
         return 0;
     }
 
@@ -1862,6 +1862,12 @@ xrdp_sec_process_mcs_data_channels(struct xrdp_sec *self, struct stream *s)
             return 1;
         }
         in_uint8a(s, channel_item->name, 8);
+        if (g_strlen(channel_item->name) == 0)
+        {
+            log_message(LOG_LEVEL_WARNING, "xrdp_sec_process_mcs_data_channels: got an empty channel name, ignoring it");
+            g_free(channel_item);
+            continue;
+        }
         in_uint32_le(s, channel_item->flags);
         channel_item->chanid = MCS_GLOBAL_CHANNEL + (index + 1);
         list_add_item(self->mcs_layer->channel_list, (tintptr) channel_item);

xrdp/xrdp_mm.c

@@ -740,8 +740,11 @@ xrdp_mm_trans_process_channel_data(struct xrdp_mm *self, struct trans *trans)
 
     if (rv == 0)
     {
-        rv = libxrdp_send_to_channel(self->wm->session, chan_id, s->p, size, total_size,
-                                     chan_flags);
+        if (is_channel_allowed(self->wm, chan_id))
+        {
+            rv = libxrdp_send_to_channel(self->wm->session, chan_id, s->p, size, total_size,
+                                         chan_flags);
+        }
     }
 
     return rv;