Wait for capabilities message from Xorg

This commit adds a stage into the Xorg connection status to wait for
the capabilities message from the Xorg server. This allows us to move
the xorgxrdp version check to xrdp from the X server for better
reporting to the user.

xup/xup.c

@@ -146,6 +146,72 @@ lib_data_in(struct trans *trans)
  return 0;
 }
 
+/******************************************************************************/
+/*
+ * Wait for module caps message from Xorg module
+ *
+ * This routine waits for the Xorg module to send a caps message.
+ *
+ * We use this to check the caps are compatible with us before we
+ * go for a fuull-on connect
+ */
+static int
+wait_for_module_caps_message(struct mod *mod)
+{
+ int robjs_count;
+ intptr_t robjs[10];
+
+ mod->caps_processing_status = E_CAPS_NOT_PROCESSED;
+
+ while (mod->caps_processing_status == E_CAPS_NOT_PROCESSED)
+ {
+ robjs_count = 0;
+ if (trans_get_wait_objs(mod->trans, robjs, &robjs_count) != 0)
+ {
+ LOG(LOG_LEVEL_ERROR, "Xorg module has dropped connection");
+ return 1;
+ }
+
+ // We don't need a big timeout here, as all the module has to do is
+ // turn around the version message.
+ int status = g_obj_wait(robjs, robjs_count, 0, 0, 3 * 1000);
+
+ if (status < 0)
+ {
+ LOG(LOG_LEVEL_ERROR, "No response from Xorg module before timeout");
+ return 1;
+ }
+
+ (void)trans_check_wait_objs(mod->trans);
+ }
+
+ return (mod->caps_processing_status == E_CAPS_OK) ? 0 : 1;
+}
+
+/******************************************************************************/
+/* return error */
+static int
+lib_send_client_info(struct mod *mod)
+{
+ struct stream *s;
+ int len;
+
+ LOG_DEVEL(LOG_LEVEL_TRACE, "lib_send_client_info:");
+ make_stream(s);
+ init_stream(s, 8192);
+ s_push_layer(s, iso_hdr, 4);
+ out_uint16_le(s, 104);
+ g_memcpy(s->p, &(mod->client_info), sizeof(mod->client_info));
+ s->p += sizeof(mod->client_info);
+ s_mark_end(s);
+ len = (int)(s->end - s->data);
+ s_pop_layer(s, iso_hdr);
+ out_uint32_le(s, len);
+ lib_send_copy(mod, s);
+ free_stream(s);
+ return 0;
+}
+
 /******************************************************************************/
 /* return error */
 static int
@@ -220,31 +286,47 @@ lib_mod_connect(struct mod *mod)
  free_stream(s);
  return 1;
  }
+
+ // Set the transport up
  mod->trans->si = mod->si;
  mod->trans->my_source = XRDP_SOURCE_MOD;
  mod->trans->is_term = mod->server_is_term;
+ mod->trans->trans_data_in = lib_data_in;
+ mod->trans->header_size = 8;
+ mod->trans->callback_data = mod;
+ mod->trans->no_stream_init_on_data_in = 1;
+ mod->trans->extra_flags = 1;
 
  /* Give the X server a bit of time to start */
- if (trans_connect(mod->trans, mod->ip, con_port, 30 * 1000) == 0)
+ error = trans_connect(mod->trans, mod->ip, con_port, 30 * 1000);
+ if (error == 0)
  {
  LOG_DEVEL(LOG_LEVEL_INFO, "lib_mod_connect: connected to Xserver "
  "(Xorg) sck %lld",
  (long long) (mod->trans->sck));
+ if (socket_mode == TRANS_MODE_UNIX)
+ {
+ lib_mod_log_peer(mod);
+ }
  }
  else
  {
  mod->server_msg(mod, "connection problem, giving up", 0);
- error = 1;
  }
 
- if (error == 0 && socket_mode == TRANS_MODE_UNIX)
+ if (error == 0)
  {
- lib_mod_log_peer(mod);
+ error = send_server_version_message(mod, s);
  }
 
  if (error == 0)
  {
- error = send_server_version_message(mod, s);
+ error = wait_for_module_caps_message(mod);
+ }
+
+ if (error == 0)
+ {
+ error = lib_send_client_info(mod);
  }
 
  if (error == 0)
@@ -259,21 +341,14 @@ lib_mod_connect(struct mod *mod)
  {
  trans_delete(mod->trans);
  mod->trans = 0;
- mod->server_msg(mod, "some problem", 0);
- return 1;
+ mod->server_msg(mod, "Error connecting to Xorg - check log", 0);
  }
  else
  {
  mod->server_msg(mod, "connected ok", 0);
- mod->trans->trans_data_in = lib_data_in;
- mod->trans->header_size = 8;
- mod->trans->callback_data = mod;
- mod->trans->no_stream_init_on_data_in = 1;
- mod->trans->extra_flags = 1;
  }
-
  LOG_DEVEL(LOG_LEVEL_TRACE, "out lib_mod_connect");
- return 0;
+ return error;
 }
 
 /******************************************************************************/
@@ -1708,30 +1783,6 @@ lib_mod_process_orders(struct mod *mod, int type, struct stream *s)
  return rv;
 }
 
-/******************************************************************************/
-/* return error */
-static int
-lib_send_client_info(struct mod *mod)
-{
- struct stream *s;
- int len;
-
- LOG_DEVEL(LOG_LEVEL_TRACE, "lib_send_client_info:");
- make_stream(s);
- init_stream(s, 8192);
- s_push_layer(s, iso_hdr, 4);
- out_uint16_le(s, 104);
- g_memcpy(s->p, &(mod->client_info), sizeof(mod->client_info));
- s->p += sizeof(mod->client_info);
- s_mark_end(s);
- len = (int)(s->end - s->data);
- s_pop_layer(s, iso_hdr);
- out_uint32_le(s, len);
- lib_send_copy(mod, s);
- free_stream(s);
- return 0;
-}
-
 /******************************************************************************/
 /* return error */
 static int
@@ -1743,6 +1794,7 @@ lib_mod_process_message(struct mod *mod, struct stream *s)
  int len;
  int type;
  char *phold;
+ int version;
 
  int width;
  int height;
@@ -1769,6 +1821,7 @@ lib_mod_process_message(struct mod *mod, struct stream *s)
  }
  else if (type == 2) /* caps */
  {
+ mod->caps_processing_status = E_CAPS_OK; /* Assume all OK */
  LOG_DEVEL(LOG_LEVEL_TRACE,
  "lib_mod_process_message: type 2 len %d", len);
  for (index = 0; index < num_orders; index++)
@@ -1779,6 +1832,20 @@ lib_mod_process_message(struct mod *mod, struct stream *s)
 
  switch (type)
  {
+ case 100:
+ in_uint32_le(s, version);
+ if (version != CLIENT_INFO_CURRENT_VERSION)
+ {
+ LOG(LOG_LEVEL_ERROR,
+ "Xorg module has version %d, expected %d",
+ version, CLIENT_INFO_CURRENT_VERSION);
+ mod->server_msg(mod,
+ "Xorg module has wrong version number",
+ 0);
+ mod->caps_processing_status = E_CAPS_NOT_OK;
+ }
+ break;
+
  default:
  LOG_DEVEL(LOG_LEVEL_TRACE,
  "lib_mod_process_message: unknown"
@@ -1788,7 +1855,6 @@ lib_mod_process_message(struct mod *mod, struct stream *s)
  }
  s->p = phold + len;
  }
- lib_send_client_info(mod);
  }
  else if (type == 3) /* order list with len after type */
  {

xup/xup.h

@@ -21,6 +21,17 @@
 #ifndef XUP_H
 #define XUP_H
 
+/**
+ * Enum for the states used to process a
+ * capabilities message from the Xorg module
+ */
+enum caps_processing_status
+{
+ E_CAPS_NOT_PROCESSED, ///< Capabilities mesage from module not processed
+ E_CAPS_OK, ///< Capabilities are OK
+ E_CAPS_NOT_OK ///< Capabilities are not OK
+};
+
 /* include other h files */
 #include "arch.h"
 #include "parse.h"
@@ -202,6 +213,7 @@ struct mod
  char *screen_shmem_pixels;
  struct trans *trans;
  char keycode_set[32];
+ enum caps_processing_status caps_processing_status;
 };
 
 #endif // XUP_H