Add CCP support to xrdp

This allows sesexec to send a reason for a connection close
request to xrdp.

xrdp is also updated to support server initiated disconnection sequences
from [MS-RDPBCGR] 1.3.1.4, along with reporting a reason to the client
for the disconnection.

libxrdp/libxrdp.c

@@ -73,9 +73,46 @@ libxrdp_exit(struct xrdp_session *session)
 
 /******************************************************************************/
 int EXPORT_CC
-libxrdp_disconnect(struct xrdp_session *session)
+libxrdp_disconnect(struct xrdp_session *session, int errinfo)
 {
-    return xrdp_rdp_disconnect((struct xrdp_rdp *)session->rdp);
+    int rv = 0;
+    struct trans *trans = NULL;
+    struct xrdp_rdp *rdp = NULL;
+    int early_capability_flags = 0;
+
+    if (session != NULL)
+    {
+        trans = session->trans;
+        rdp = (struct xrdp_rdp *)session->rdp;
+        if (session->client_info != NULL)
+        {
+            early_capability_flags =
+                session->client_info->mcs_early_capability_flags;
+        }
+    }
+
+    if (trans != NULL && trans->status == TRANS_STATUS_UP &&
+            trans->sck >= 0 && rdp != NULL)
+    {
+        /* Only send the error info PDU if the client has
+         * indicated it can receive it */
+        if ((early_capability_flags & RNS_UD_CS_SUPPORT_ERRINFO_PDU) != 0)
+        {
+            rv = xrdp_rdp_send_set_error(rdp, errinfo);
+        }
+
+        if (rv == 0)
+        {
+            rv = xrdp_rdp_send_deactivate(rdp);
+        }
+
+        if (rv == 0)
+        {
+            rv = xrdp_rdp_disconnect(rdp);
+        }
+    }
+
+    return rv;
 }
 
 /******************************************************************************/

libxrdp/libxrdp.h

@@ -456,6 +456,18 @@ xrdp_rdp_send_deactivate(struct xrdp_rdp *self);
 int
 xrdp_rdp_send_session_info(struct xrdp_rdp *self, const char *data,
                            int data_bytes);
+/**
+ * Send a [MS-RDPBCGR] TS_SET_ERROR_INFO_PDU message
+ * @param self xrdp_rdp struct
+ * @param reason errinfo code ([MS-RDPBCGR] 2.2.5.1.1)
+ * @return != 0 for error
+
+ * The caller is responsible for checking the client supports
+ * reception of this message (see 2.2.5.1)
+ */
+int
+xrdp_rdp_send_set_error(struct xrdp_rdp *self, int reason);
+
 /**
  * Request output suppress or resume
  *

libxrdp/libxrdpinc.h

@@ -104,8 +104,18 @@ struct xrdp_session *
 libxrdp_init(tbus id, struct trans *trans, const char *xrdp_ini);
 int
 libxrdp_exit(struct xrdp_session *session);
+/**
+ * Sends a disconnect sequence from the server ([MS-RDPBCGR] 1.3.1.4.x)
+ * @param session xrdp session
+ * @param errinfo Reason ([MS-RDPBCGR] 2.2.5.1.1)
+ * @return != 0 for an error
+ *
+ * After this call, the rdp channel is closed and cannot be re-used. This
+ * routine can be called more than once, but only the first call is
+ * effective.
+ */
 int
-libxrdp_disconnect(struct xrdp_session *session);
+libxrdp_disconnect(struct xrdp_session *session, int errinfo);
 int
 libxrdp_process_incoming(struct xrdp_session *session);
 int EXPORT_CC

libxrdp/xrdp_rdp.c

@@ -1364,11 +1364,9 @@ xrdp_rdp_send_disconnect_query_response(struct xrdp_rdp *self)
     return 0;
 }
 
-#if 0 /* not used */
 /*****************************************************************************/
-/* Send a [MS-RDPBCGR] TS_SET_ERROR_INFO_PDU message */
-static int
-xrdp_rdp_send_disconnect_reason(struct xrdp_rdp *self, int reason)
+int
+xrdp_rdp_send_set_error(struct xrdp_rdp *self, int reason)
 {
     struct stream *s;
 
@@ -1378,7 +1376,7 @@ xrdp_rdp_send_disconnect_reason(struct xrdp_rdp *self, int reason)
     if (xrdp_rdp_init_data(self, s) != 0)
     {
         LOG(LOG_LEVEL_ERROR,
-            "xrdp_rdp_send_disconnect_reason: xrdp_rdp_init_data failed");
+            "xrdp_rdp_send_set_error_pdu: xrdp_rdp_init_data failed");
         free_stream(s);
         return 1;
     }
@@ -1399,7 +1397,6 @@ xrdp_rdp_send_disconnect_reason(struct xrdp_rdp *self, int reason)
     free_stream(s);
     return 0;
 }
-#endif
 
 /*****************************************************************************/
 /* Process a [MS-RDPRFX] TS_FRAME_ACKNOWLEDGE_PDU message */