/* * Copyright (C) 2013 Glyptodon LLC * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "config.h" #include "client.h" #include "guac_cursor.h" #include "guac_display.h" #include "rdp.h" #include "rdp_bitmap.h" #include "rdp_cliprdr.h" #include "rdp_gdi.h" #include "rdp_glyph.h" #include "rdp_keymap.h" #include "rdp_pointer.h" #include "rdp_rail.h" #include "rdp_stream.h" #include "rdp_svc.h" #ifdef ENABLE_COMMON_SSH #include #include #include #endif #ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT #include "rdp_disp.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_FREERDP_CLIENT_CLIPRDR_H #include #else #include "compat/client-cliprdr.h" #endif #ifdef HAVE_FREERDP_CLIENT_DISP_H #include #endif #ifdef HAVE_FREERDP_EVENT_PUBSUB #include #endif #ifdef LEGACY_FREERDP #include "compat/rail.h" #else #include #endif #ifdef ENABLE_WINPR #include #else #include "compat/winpr-wtypes.h" #endif #ifdef HAVE_FREERDP_ADDIN_H #include #endif #ifdef HAVE_FREERDP_CLIENT_CHANNELS_H #include #endif #ifdef HAVE_FREERDP_VERSION_H #include #endif #include #include #include #include #include #include #include /** * Callback invoked by FreeRDP for data received along a channel. This is the * most recent version of the callback and uses a 16-bit unsigned integer for * the channel ID, as well as different type naming for the datatype of the * data itself. This function does nothing more than invoke * freerdp_channels_data() with the given arguments. The prototypes of these * functions are compatible in 1.2 and later, but not necessarily prior to * that, hence the conditional compilation of differing prototypes. * * Beware that the official purpose of these parameters is an undocumented * mystery. The meanings below are derived from looking at how the function is * used within FreeRDP. * * @param rdp_inst * The RDP client instance associated with the channel receiving the data. * * @param channelId * The integer ID of the channel that received the data. * * @param data * A buffer containing the received data. * * @param size * The number of bytes received and contained in the given buffer (the * number of bytes received within the PDU that resulted in this function * being inboked). * * @param flags * Channel control flags, as defined by the CHANNEL_PDU_HEADER in the RDP * specification. * * @param total_size * The total length of the chanel data being received, which may span * multiple PDUs (see the "length" field of CHANNEL_PDU_HEADER). * * @return * Zero if the received channel data was successfully handled, non-zero * otherwise. Note that this return value is discarded in practice. */ #if defined(FREERDP_VERSION_MAJOR) \ && (FREERDP_VERSION_MAJOR > 1 || FREERDP_VERSION_MINOR >= 2) static int __guac_receive_channel_data(freerdp* rdp_inst, UINT16 channelId, BYTE* data, int size, int flags, int total_size) { #else static int __guac_receive_channel_data(freerdp* rdp_inst, int channelId, UINT8* data, int size, int flags, int total_size) { #endif return freerdp_channels_data(rdp_inst, channelId, data, size, flags, total_size); } #ifdef HAVE_FREERDP_EVENT_PUBSUB /** * Called whenever a channel connects via the PubSub event system within * FreeRDP. * * @param context The rdpContext associated with the active RDP session. * @param e Event-specific arguments, mainly the name of the channel, and a * reference to the associated plugin loaded for that channel by * FreeRDP. */ static void guac_rdp_channel_connected(rdpContext* context, ChannelConnectedEventArgs* e) { #ifdef HAVE_RDPSETTINGS_SUPPORTDISPLAYCONTROL /* Store reference to the display update plugin once it's connected */ if (strcmp(e->name, DISP_DVC_CHANNEL_NAME) == 0) { DispClientContext* disp = (DispClientContext*) e->pInterface; guac_client* client = ((rdp_freerdp_context*) context)->client; guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; /* Init module with current display size */ guac_rdp_disp_set_size(rdp_client->disp, context, guac_rdp_get_width(context->instance), guac_rdp_get_height(context->instance)); /* Store connected channel */ guac_rdp_disp_connect(rdp_client->disp, disp); guac_client_log(client, GUAC_LOG_DEBUG, "Display update channel connected."); } #endif } #endif BOOL rdp_freerdp_pre_connect(freerdp* instance) { rdpContext* context = instance->context; guac_client* client = ((rdp_freerdp_context*) context)->client; rdpChannels* channels = context->channels; rdpBitmap* bitmap; rdpGlyph* glyph; rdpPointer* pointer; rdpPrimaryUpdate* primary; CLRCONV* clrconv; guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; #ifdef HAVE_FREERDP_REGISTER_ADDIN_PROVIDER /* Init FreeRDP add-in provider */ freerdp_register_addin_provider(freerdp_channels_load_static_addin_entry, 0); #endif #ifdef HAVE_FREERDP_EVENT_PUBSUB /* Subscribe to and handle channel connected events */ PubSub_SubscribeChannelConnected(context->pubSub, (pChannelConnectedEventHandler) guac_rdp_channel_connected); #endif #ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT /* Load virtual channel management plugin */ if (freerdp_channels_load_plugin(channels, instance->settings, "drdynvc", instance->settings)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load drdynvc plugin."); /* Init display update plugin */ rdp_client->disp = guac_rdp_disp_alloc(); guac_rdp_disp_load_plugin(instance->context); #endif /* Load clipboard plugin */ if (freerdp_channels_load_plugin(channels, instance->settings, "cliprdr", NULL)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load cliprdr plugin. Clipboard will not work."); /* If audio enabled, choose an encoder */ if (rdp_client->settings->audio_enabled) { rdp_client->audio = guac_audio_stream_alloc(client, NULL, GUAC_RDP_AUDIO_RATE, GUAC_RDP_AUDIO_CHANNELS, GUAC_RDP_AUDIO_BPS); /* Warn if no audio encoding is available */ if (rdp_client->audio == NULL) guac_client_log(client, GUAC_LOG_INFO, "No available audio encoding. Sound disabled."); } /* end if audio enabled */ /* Load filesystem if drive enabled */ if (rdp_client->settings->drive_enabled) rdp_client->filesystem = guac_rdp_fs_alloc(client, rdp_client->settings->drive_path, rdp_client->settings->create_drive_path); /* If RDPSND/RDPDR required, load them */ if (rdp_client->settings->printing_enabled || rdp_client->settings->drive_enabled || rdp_client->settings->audio_enabled) { /* Load RDPDR plugin */ if (freerdp_channels_load_plugin(channels, instance->settings, "guacdr", client)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load guacdr plugin. Drive redirection and " "printing will not work. Sound MAY not work."); /* Load RDPSND plugin */ if (freerdp_channels_load_plugin(channels, instance->settings, "guacsnd", client)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load guacsnd alongside guacdr plugin. Sound " "will not work. Drive redirection and printing MAY not " "work."); } /* Load RAIL plugin if RemoteApp in use */ if (rdp_client->settings->remote_app != NULL) { #ifdef LEGACY_FREERDP RDP_PLUGIN_DATA* plugin_data = malloc(sizeof(RDP_PLUGIN_DATA) * 2); plugin_data[0].size = sizeof(RDP_PLUGIN_DATA); plugin_data[0].data[0] = rdp_client->settings->remote_app; plugin_data[0].data[1] = rdp_client->settings->remote_app_dir; plugin_data[0].data[2] = rdp_client->settings->remote_app_args; plugin_data[0].data[3] = NULL; plugin_data[1].size = 0; /* Attempt to load rail */ if (freerdp_channels_load_plugin(channels, instance->settings, "rail", plugin_data)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load rail plugin. RemoteApp will not work."); #else /* Attempt to load rail */ if (freerdp_channels_load_plugin(channels, instance->settings, "rail", instance->settings)) guac_client_log(client, GUAC_LOG_WARNING, "Failed to load rail plugin. RemoteApp will not work."); #endif } /* Load SVC plugin instances for all static channels */ if (rdp_client->settings->svc_names != NULL) { char** current = rdp_client->settings->svc_names; do { guac_rdp_svc* svc = guac_rdp_alloc_svc(client, *current); /* Attempt to load guacsvc plugin for new static channel */ if (freerdp_channels_load_plugin(channels, instance->settings, "guacsvc", svc)) { guac_client_log(client, GUAC_LOG_WARNING, "Cannot create static channel \"%s\": failed to load guacsvc plugin.", svc->name); guac_rdp_free_svc(svc); } /* Store and log on success */ else { guac_rdp_add_svc(client, svc); guac_client_log(client, GUAC_LOG_INFO, "Created static channel \"%s\"...", svc->name); } } while (*(++current) != NULL); } /* Init color conversion structure */ clrconv = calloc(1, sizeof(CLRCONV)); clrconv->alpha = 1; clrconv->invert = 0; clrconv->rgb555 = 0; clrconv->palette = calloc(1, sizeof(rdpPalette)); ((rdp_freerdp_context*) context)->clrconv = clrconv; /* Init FreeRDP cache */ instance->context->cache = cache_new(instance->settings); /* Set up bitmap handling */ bitmap = calloc(1, sizeof(rdpBitmap)); bitmap->size = sizeof(guac_rdp_bitmap); bitmap->New = guac_rdp_bitmap_new; bitmap->Free = guac_rdp_bitmap_free; bitmap->Paint = guac_rdp_bitmap_paint; bitmap->Decompress = guac_rdp_bitmap_decompress; bitmap->SetSurface = guac_rdp_bitmap_setsurface; graphics_register_bitmap(context->graphics, bitmap); free(bitmap); /* Set up glyph handling */ glyph = calloc(1, sizeof(rdpGlyph)); glyph->size = sizeof(guac_rdp_glyph); glyph->New = guac_rdp_glyph_new; glyph->Free = guac_rdp_glyph_free; glyph->Draw = guac_rdp_glyph_draw; glyph->BeginDraw = guac_rdp_glyph_begindraw; glyph->EndDraw = guac_rdp_glyph_enddraw; graphics_register_glyph(context->graphics, glyph); free(glyph); /* Set up pointer handling */ pointer = calloc(1, sizeof(rdpPointer)); pointer->size = sizeof(guac_rdp_pointer); pointer->New = guac_rdp_pointer_new; pointer->Free = guac_rdp_pointer_free; pointer->Set = guac_rdp_pointer_set; #ifdef HAVE_RDPPOINTER_SETNULL pointer->SetNull = guac_rdp_pointer_set_null; #endif #ifdef HAVE_RDPPOINTER_SETDEFAULT pointer->SetDefault = guac_rdp_pointer_set_default; #endif graphics_register_pointer(context->graphics, pointer); free(pointer); /* Set up GDI */ instance->update->DesktopResize = guac_rdp_gdi_desktop_resize; instance->update->EndPaint = guac_rdp_gdi_end_paint; instance->update->Palette = guac_rdp_gdi_palette_update; instance->update->SetBounds = guac_rdp_gdi_set_bounds; primary = instance->update->primary; primary->DstBlt = guac_rdp_gdi_dstblt; primary->PatBlt = guac_rdp_gdi_patblt; primary->ScrBlt = guac_rdp_gdi_scrblt; primary->MemBlt = guac_rdp_gdi_memblt; primary->OpaqueRect = guac_rdp_gdi_opaquerect; pointer_cache_register_callbacks(instance->update); glyph_cache_register_callbacks(instance->update); brush_cache_register_callbacks(instance->update); bitmap_cache_register_callbacks(instance->update); offscreen_cache_register_callbacks(instance->update); palette_cache_register_callbacks(instance->update); /* Init channels (pre-connect) */ if (freerdp_channels_pre_connect(channels, instance)) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error initializing RDP client channel manager"); return FALSE; } return TRUE; } BOOL rdp_freerdp_post_connect(freerdp* instance) { rdpContext* context = instance->context; guac_client* client = ((rdp_freerdp_context*) context)->client; rdpChannels* channels = instance->context->channels; /* Init channels (post-connect) */ if (freerdp_channels_post_connect(channels, instance)) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error initializing RDP client channel manager"); return FALSE; } return TRUE; } BOOL rdp_freerdp_authenticate(freerdp* instance, char** username, char** password, char** domain) { rdpContext* context = instance->context; guac_client* client = ((rdp_freerdp_context*) context)->client; /* Warn if connection is likely to fail due to lack of credentials */ guac_client_log(client, GUAC_LOG_INFO, "Authentication requested but username or password not given"); return TRUE; } BOOL rdp_freerdp_verify_certificate(freerdp* instance, char* subject, char* issuer, char* fingerprint) { rdpContext* context = instance->context; guac_client* client = ((rdp_freerdp_context*) context)->client; guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; /* Bypass validation if ignore_certificate given */ if (rdp_client->settings->ignore_certificate) { guac_client_log(client, GUAC_LOG_INFO, "Certificate validation bypassed"); return TRUE; } guac_client_log(client, GUAC_LOG_INFO, "Certificate validation failed"); return FALSE; } void rdp_freerdp_context_new(freerdp* instance, rdpContext* context) { context->channels = freerdp_channels_new(); } void rdp_freerdp_context_free(freerdp* instance, rdpContext* context) { /* EMPTY */ } void __guac_rdp_client_load_keymap(guac_client* client, const guac_rdp_keymap* keymap) { guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; /* Get mapping */ const guac_rdp_keysym_desc* mapping = keymap->mapping; /* If parent exists, load parent first */ if (keymap->parent != NULL) __guac_rdp_client_load_keymap(client, keymap->parent); /* Log load */ guac_client_log(client, GUAC_LOG_INFO, "Loading keymap \"%s\"", keymap->name); /* Load mapping into keymap */ while (mapping->keysym != 0) { /* Copy mapping */ GUAC_RDP_KEYSYM_LOOKUP(rdp_client->keymap, mapping->keysym) = *mapping; /* Next keysym */ mapping++; } } /** * Waits for messages from the RDP server for the given number of microseconds. * * @param client The client associated with the current RDP session. * @param timeout_usecs The maximum amount of time to wait, in microseconds. * * @return * A positive value if messages are ready, zero if the specified timeout * period elapsed, or a negative value if an error occurs. */ static int rdp_guac_client_wait_for_messages(guac_client* client, int timeout_usecs) { guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; freerdp* rdp_inst = rdp_client->rdp_inst; rdpChannels* channels = rdp_inst->context->channels; int result; int index; int max_fd, fd; void* read_fds[32]; void* write_fds[32]; int read_count = 0; int write_count = 0; fd_set rfds, wfds; struct timeval timeout = { .tv_sec = 0, .tv_usec = timeout_usecs }; /* Get RDP fds */ if (!freerdp_get_fds(rdp_inst, read_fds, &read_count, write_fds, &write_count)) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to read RDP file descriptors."); return -1; } /* Get channel fds */ if (!freerdp_channels_get_fds(channels, rdp_inst, read_fds, &read_count, write_fds, &write_count)) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to read RDP channel file descriptors."); return -1; } /* Construct read fd_set */ max_fd = 0; FD_ZERO(&rfds); for (index = 0; index < read_count; index++) { fd = (int)(long) (read_fds[index]); if (fd > max_fd) max_fd = fd; FD_SET(fd, &rfds); } /* Construct write fd_set */ FD_ZERO(&wfds); for (index = 0; index < write_count; index++) { fd = (int)(long) (write_fds[index]); if (fd > max_fd) max_fd = fd; FD_SET(fd, &wfds); } /* If no file descriptors, error */ if (max_fd == 0) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "No file descriptors associated with RDP connection."); return -1; } /* Wait for all RDP file descriptors */ result = select(max_fd + 1, &rfds, &wfds, NULL, &timeout); if (result < 0) { /* If error ignorable, pretend timout occurred */ if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINPROGRESS || errno == EINTR) return 0; /* Otherwise, return as error */ guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error waiting for file descriptor."); return -1; } /* Return wait result */ return result; } void* guac_rdp_client_thread(void* data) { guac_client* client = (guac_client*) data; guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; guac_rdp_settings* settings = rdp_client->settings; /* Init random number generator */ srandom(time(NULL)); /* Create display */ rdp_client->display = guac_common_display_alloc(client, rdp_client->settings->width, rdp_client->settings->height); rdp_client->current_surface = rdp_client->display->default_surface; #ifdef HAVE_FREERDP_CHANNELS_GLOBAL_INIT freerdp_channels_global_init(); #endif /* Init client */ freerdp* rdp_inst = freerdp_new(); rdp_inst->PreConnect = rdp_freerdp_pre_connect; rdp_inst->PostConnect = rdp_freerdp_post_connect; rdp_inst->Authenticate = rdp_freerdp_authenticate; rdp_inst->VerifyCertificate = rdp_freerdp_verify_certificate; rdp_inst->ReceiveChannelData = __guac_receive_channel_data; /* Allocate FreeRDP context */ #ifdef LEGACY_FREERDP rdp_inst->context_size = sizeof(rdp_freerdp_context); #else rdp_inst->ContextSize = sizeof(rdp_freerdp_context); #endif rdp_inst->ContextNew = (pContextNew) rdp_freerdp_context_new; rdp_inst->ContextFree = (pContextFree) rdp_freerdp_context_free; freerdp_context_new(rdp_inst); ((rdp_freerdp_context*) rdp_inst->context)->client = client; /* Load keymap into client */ __guac_rdp_client_load_keymap(client, settings->server_layout); #ifdef ENABLE_COMMON_SSH guac_common_ssh_init(client); /* Connect via SSH if SFTP is enabled */ if (settings->enable_sftp) { /* Abort if username is missing */ if (settings->sftp_username == NULL) return NULL; guac_client_log(client, GUAC_LOG_DEBUG, "Connecting via SSH for SFTP filesystem access."); rdp_client->sftp_user = guac_common_ssh_create_user(settings->sftp_username); /* Import private key, if given */ if (settings->sftp_private_key != NULL) { guac_client_log(client, GUAC_LOG_DEBUG, "Authenticating with private key."); /* Abort if private key cannot be read */ if (guac_common_ssh_user_import_key(rdp_client->sftp_user, settings->sftp_private_key, settings->sftp_passphrase)) { guac_common_ssh_destroy_user(rdp_client->sftp_user); return NULL; } } /* Otherwise, use specified password */ else { guac_client_log(client, GUAC_LOG_DEBUG, "Authenticating with password."); guac_common_ssh_user_set_password(rdp_client->sftp_user, settings->sftp_password); } /* Attempt SSH connection */ rdp_client->sftp_session = guac_common_ssh_create_session(client, settings->sftp_hostname, settings->sftp_port, rdp_client->sftp_user); /* Fail if SSH connection does not succeed */ if (rdp_client->sftp_session == NULL) { /* Already aborted within guac_common_ssh_create_session() */ guac_common_ssh_destroy_user(rdp_client->sftp_user); return NULL; } /* Load and expose filesystem */ rdp_client->sftp_filesystem = guac_common_ssh_create_sftp_filesystem( rdp_client->sftp_session, "/"); /* Expose filesystem to connection owner */ guac_client_for_owner(client, guac_common_ssh_expose_sftp_filesystem, rdp_client->sftp_filesystem); /* Abort if SFTP connection fails */ if (rdp_client->sftp_filesystem == NULL) { guac_common_ssh_destroy_session(rdp_client->sftp_session); guac_common_ssh_destroy_user(rdp_client->sftp_user); return NULL; } guac_client_log(client, GUAC_LOG_DEBUG, "SFTP connection succeeded."); } #endif /* Send connection name */ guac_protocol_send_name(client->socket, settings->hostname); /* Set default pointer */ guac_common_cursor_set_pointer(rdp_client->display->cursor); /* Push desired settings to FreeRDP */ guac_rdp_push_settings(settings, rdp_inst); /* Connect to RDP server */ if (!freerdp_connect(rdp_inst)) { guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Error connecting to RDP server"); return NULL; } /* Connection complete */ rdp_client->rdp_inst = rdp_inst; rdpChannels* channels = rdp_inst->context->channels; /* Handle messages from RDP server while client is running */ while (client->state == GUAC_CLIENT_RUNNING) { #ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT /* Update remote display size */ pthread_mutex_lock(&(rdp_client->rdp_lock)); guac_rdp_disp_update_size(rdp_client->disp, rdp_inst->context); pthread_mutex_unlock(&(rdp_client->rdp_lock)); #endif /* Wait for data and construct a reasonable frame */ int wait_result = rdp_guac_client_wait_for_messages(client, 250000); guac_timestamp frame_start = guac_timestamp_current(); while (wait_result > 0) { guac_timestamp frame_end; int frame_remaining; pthread_mutex_lock(&(rdp_client->rdp_lock)); /* Check the libfreerdp fds */ if (!freerdp_check_fds(rdp_inst)) { guac_client_log(client, GUAC_LOG_DEBUG, "Error handling RDP file descriptors"); pthread_mutex_unlock(&(rdp_client->rdp_lock)); return NULL; } /* Check channel fds */ if (!freerdp_channels_check_fds(channels, rdp_inst)) { guac_client_log(client, GUAC_LOG_DEBUG, "Error handling RDP channel file descriptors"); pthread_mutex_unlock(&(rdp_client->rdp_lock)); return NULL; } /* Check for channel events */ wMessage* event = freerdp_channels_pop_event(channels); if (event) { /* Handle channel events (clipboard and RAIL) */ #ifdef LEGACY_EVENT if (event->event_class == CliprdrChannel_Class) guac_rdp_process_cliprdr_event(client, event); else if (event->event_class == RailChannel_Class) guac_rdp_process_rail_event(client, event); #else if (GetMessageClass(event->id) == CliprdrChannel_Class) guac_rdp_process_cliprdr_event(client, event); else if (GetMessageClass(event->id) == RailChannel_Class) guac_rdp_process_rail_event(client, event); #endif freerdp_event_free(event); } /* Handle RDP disconnect */ if (freerdp_shall_disconnect(rdp_inst)) { guac_client_log(client, GUAC_LOG_INFO, "RDP server closed connection"); pthread_mutex_unlock(&(rdp_client->rdp_lock)); return NULL; } pthread_mutex_unlock(&(rdp_client->rdp_lock)); /* Calculate time remaining in frame */ frame_end = guac_timestamp_current(); frame_remaining = frame_start + GUAC_RDP_FRAME_DURATION - frame_end; /* Wait again if frame remaining */ if (frame_remaining > 0) wait_result = rdp_guac_client_wait_for_messages(client, GUAC_RDP_FRAME_TIMEOUT*1000); else break; } /* If an error occurred, fail */ if (wait_result < 0) guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Connection closed."); /* End of frame */ guac_common_display_flush(rdp_client->display); guac_client_end_frame(client); guac_socket_flush(client->socket); } guac_client_log(client, GUAC_LOG_INFO, "Internal RDP client disconnected"); return NULL; }