libvncserver: continuous updates

Author: Volodymyr Samokhatko

CMakeLists.txt

@@ -388,6 +388,7 @@ set(LIBVNCSERVER_SOURCES
     ${LIBVNCSERVER_DIR}/ultra.c
     ${LIBVNCSERVER_DIR}/scale.c
     ${CRYPTO_SOURCES}
+    ${LIBVNCSERVER_DIR}/flowcontrol.c
     ${LIBVNCSERVER_DIR}/rfbtimers.c
 )
 

include/rfb/rfb.h

@@ -41,7 +41,9 @@ extern "C"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <rfb/rfblist.h>
 #include <rfb/rfbproto.h>
+#include <rfb/rfbtimers.h>
 
 #if defined(ANDROID) || defined(LIBVNCSERVER_HAVE_ANDROID)
 #include <arpa/inet.h>
@@ -372,9 +374,18 @@ typedef struct _rfbScreenInfo
 #ifdef LIBVNCSERVER_HAVE_LIBZ
     rfbSetXCutTextUTF8ProcPtr setXCutTextUTF8;
 #endif
+    rfbBool rfbCongestionControl;
 } rfbScreenInfo, *rfbScreenInfoPtr;
 
 
+typedef struct {
+  struct timeval tv;
+  unsigned pos, extra;
+  char congested;
+  struct rfb_list entry;
+} rfbRTTInfo;
+
+
 /**
  * rfbTranslateFnType is the type of translation functions.
  */
@@ -707,6 +718,34 @@ typedef struct _rfbClientRec {
     int tightPngDstDataLen;
 #endif
 #endif
+
+    /* flow control extensions */
+
+    rfbBool enableCU;                 /**< client supports Continuous Updates */
+    rfbBool enableFence;              /**< client supports fence extension */
+
+    rfbBool continuousUpdates;
+    sraRegionPtr cuRegion;
+
+    rfbTimersPtr timers;
+
+    rfbBool pendingSyncFence, syncFence;
+    uint32_t fenceFlags;
+    unsigned fenceDataLen;
+    char fenceData[64];
+
+    unsigned lastPosition, extraBuffer;
+    struct timeval lastUpdate, lastSent;
+    unsigned baseRTT, congWindow;
+    rfbBool inSlowStart;
+    int sockOffset;
+    struct rfb_list pings;
+    rfbTimerPtr congestionTimer;
+    rfbRTTInfo lastPong;
+    struct timeval lastPongArrival;
+    int measurements;
+    struct timeval lastAdjustment;
+    unsigned minRTT, minCongestedRTT;
 } rfbClientRec, *rfbClientPtr;
 
 /**
@@ -755,9 +794,12 @@ extern int rfbMaxClientWait;
 
 extern void rfbInitSockets(rfbScreenInfoPtr rfbScreen);
 extern void rfbShutdownSockets(rfbScreenInfoPtr rfbScreen);
+extern void rfbCorkSock(int sock);
+extern void rfbUncorkSock(int sock);
 extern void rfbDisconnectUDPSock(rfbScreenInfoPtr rfbScreen);
 extern void rfbCloseClient(rfbClientPtr cl);
 extern int rfbReadExact(rfbClientPtr cl, char *buf, int len);
+extern int rfbSkipExact(rfbClientPtr cl, int len);
 extern int rfbReadExactTimeout(rfbClientPtr cl, char *buf, int len,int timeout);
 extern int rfbPeekExactTimeout(rfbClientPtr cl, char *buf, int len,int timeout);
 extern int rfbWriteExact(rfbClientPtr cl, const char *buf, int len);

include/rfb/rfbproto.h

@@ -431,13 +431,20 @@ typedef struct {
 /* Modif cs@2005 */
 /* PalmVNC 1.4 & 2.0 SetScale Factor message */
 #define rfbPalmVNCSetScaleFactor 0xF
+#define rfbEnableContinuousUpdates 150
+#define rfbEndOfContinuousUpdates 150
 /* Xvp message - bidirectional */
 #define rfbXvp 250
 /* SetDesktopSize client -> server message */
 #define rfbSetDesktopSize 251
 #define rfbQemuEvent 255
 
 
+/*-----------------------------------------------------------------------------
+ * server -> client and client -> server
+ */
+
+#define rfbFence 248
 
 
 /*****************************************************************************
@@ -528,6 +535,9 @@ typedef struct {
 #define rfbEncodingQualityLevel8   0xFFFFFFE8
 #define rfbEncodingQualityLevel9   0xFFFFFFE9
 
+#define rfbEncodingContinuousUpdates    0xFFFFFEC7
+#define rfbEncodingFence                0xFFFFFEC8
+
 #define rfbEncodingQemuExtendedKeyEvent 0xFFFFFEFE /* -258 */
 #define rfbEncodingExtendedClipboard 0xC0A1E5CE
 
@@ -538,6 +548,37 @@ typedef struct {
 #define rfbEncodingServerIdentity     0xFFFE0003
 
 
+/*****************************************************************************
+ *
+ * Message definitions (server -> client and client -> server)
+ *
+ *****************************************************************************/
+
+/*-----------------------------------------------------------------------------
+ * Fence
+ */
+
+/* flags */
+#define rfbFenceFlagBlockBefore 1
+#define rfbFenceFlagBlockAfter 2
+#define rfbFenceFlagSyncNext 4
+#define rfbFenceFlagRequest 0x80000000
+#define rfbFenceFlagsSupported (rfbFenceFlagBlockBefore | \
+                                rfbFenceFlagBlockAfter | \
+                                rfbFenceFlagSyncNext | \
+                                rfbFenceFlagRequest)
+
+typedef struct _rfbFenceMsg {
+    uint8_t type;                 /* always rfbFence */
+    uint8_t pad[3];
+    uint32_t flags;
+    uint8_t length;
+    /* Followed by char data[length] */
+} rfbFenceMsg;
+
+#define sz_rfbFenceMsg 9
+
+
 /*****************************************************************************
  *
  * Server -> client message definitions
@@ -1267,6 +1308,7 @@ typedef union {
 	rfbTextChatMsg tc;
 	rfbXvpMsg xvp;
 	rfbExtDesktopSizeMsg eds;
+    rfbFenceMsg f;
 } rfbServerToClientMsg;
 
 
@@ -1523,6 +1565,22 @@ typedef struct _rfbSetSWMsg {
 #define sz_rfbSetSWMsg 6
 
 
+/*-----------------------------------------------------------------------------
+ * EnableContinuousUpdates
+ */
+
+typedef struct _rfbEnableContinuousUpdatesMsg {
+    uint8_t type;                 /* always rfbEnableContinuousUpdates */
+    uint8_t enable;
+    uint16_t x;
+    uint16_t y;
+    uint16_t w;
+    uint16_t h;
+} rfbEnableContinuousUpdatesMsg;
+
+#define sz_rfbEnableContinuousUpdatesMsg 10
+
+
 
 /*-----------------------------------------------------------------------------
  * Union of all client->server messages.
@@ -1545,6 +1603,8 @@ typedef union {
 	rfbTextChatMsg tc;
 	rfbXvpMsg xvp;
 	rfbSetDesktopSizeMsg sdm;
+    rfbEnableContinuousUpdatesMsg ecu;
+    rfbFenceMsg f;
 } rfbClientToServerMsg;
 
 /* 

include/rfb/threading.h

@@ -77,6 +77,7 @@
 #endif
 #elif defined(LIBVNCSERVER_HAVE_WIN32THREADS)
 #include <process.h>
+#include <windows.h>
 #define LOCK(mutex)                   EnterCriticalSection(&(mutex))
 #define UNLOCK(mutex)                 LeaveCriticalSection(&(mutex))
 #define MUTEX(mutex)                  CRITICAL_SECTION (mutex)

src/libvncserver/cargs.c

@@ -43,6 +43,8 @@ rfbUsage(void)
                                                              "new non-shared\n"
                     "                       connection comes in (refuse new connection "
                                                                 "instead)\n");
+    fprintf(stderr, "-noflowcontrol         when continuous updates are enabled, send updates\n"
+                    "                       whether or not the viewer is ready to receive them\n");
 #ifdef LIBVNCSERVER_WITH_WEBSOCKETS
     fprintf(stderr, "-sslkeyfile path       set path to private key file for encrypted WebSockets connections\n");
     fprintf(stderr, "-sslcertfile path      set path to certificate file for encrypted WebSockets connections\n");
@@ -158,6 +160,8 @@ rfbProcessArguments(rfbScreenInfoPtr rfbScreen,int* argc, char *argv[])
             rfbScreen->neverShared = TRUE;
         } else if (strcmp(argv[i], "-dontdisconnect") == 0) {
             rfbScreen->dontDisconnect = TRUE;
+        } else if (strcmp(argv[i], "-noflowcontrol") == 0) {
+           rfbScreen->rfbCongestionControl = FALSE;
         } else if (strcmp(argv[i], "-httpdir") == 0) {  /* -httpdir directory-path */
             if (i + 1 >= *argc) {
 		rfbUsage();