Introduce generic protocol extension method. Deprecate

the processCustomClientMessage() method.

ChangeLog

+2005-09-27  Rohit Kumar <rokumar@novell.com>
+	* libvncserver/{cargs,sockets,main,rfbserver}.c,
+	  rfb/rfb.h: Provide a generic means to extend the RFB
+	  protocol: rfbRegisterProtocolExtension(extension). This
+	  deprecates the current (very limited) option to override
+	  rfbScreenInfoPtr->processCustomClientMessage(client).
+
 2005-09-26  Rohit Kumar <rokumar@novell.com>
 	* libvncserver/{auth,main,rfbserver}.c, rfb/{rfb,rfbproto}.h:
 	  support VNC protocol version 3.7. This allows to add security

libvncserver/cargs.c

@@ -19,6 +19,8 @@ extern int rfbStringToAddr(char *str, in_addr_t *iface);
 void
 rfbUsage(void)
 {
+    rfbProtocolExtension* extension;
+
     fprintf(stderr, "-rfbport port          TCP port for RFB protocol\n");
     fprintf(stderr, "-rfbwait time          max time in ms to wait for RFB client\n");
     fprintf(stderr, "-rfbauth passwd-file   use authentication on RFB protocol\n"
@@ -40,6 +42,11 @@ rfbUsage(void)
     fprintf(stderr, "-progressive height    enable progressive updating for slow links\n");
     fprintf(stderr, "-listen ipaddr         listen for connections only on network interface with\n");
     fprintf(stderr, "                       addr ipaddr. '-listen localhost' and hostname work too.\n");
+
+    for(extension=rfbGetExtensionIterator();extension;extension=extension->next)
+	if(extension->usage)
+		extension->usage();
+    rfbReleaseExtensionIterator();
 }
 
 /* purges COUNT arguments from ARGV at POSITION and decrements ARGC.
@@ -138,10 +145,22 @@ rfbProcessArguments(rfbScreenInfoPtr rfbScreen,int* argc, char *argv[])
                 return FALSE;
             }
         } else {
+	    rfbProtocolExtension* extension;
+	    int handled=0;
+
+	    for(extension=rfbGetExtensionIterator();handled==0 && extension;
+			extension=extension->next)
+		if(extension->processArgument)
+			handled = extension->processArgument(argv + i);
+	    rfbReleaseExtensionIterator();
+
+	    if(handled==0) {
 		i++;
 		i1=i;
 		continue;
 	    }
+	    i+=handled-1;
+	}
 	/* we just remove the processed arguments from the list */
 	rfbPurgeArguments(argc,&i1,i-i1+1,argv);
 	i=i1;

libvncserver/main.c

@@ -40,6 +40,7 @@
 
 #ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
 static MUTEX(logMutex);
+static MUTEX(extMutex);
 #endif
 
 static int rfbEnableLogging=1;
@@ -50,6 +51,43 @@ char rfbEndianTest = 0;
 char rfbEndianTest = -1;
 #endif
 
+/*
+ * Protocol extensions
+ */
+
+static rfbProtocolExtension* rfbExtensionHead = NULL;
+
+void
+rfbRegisterProtocolExtension(rfbProtocolExtension* extension)
+{
+	rfbProtocolExtension* last;
+
+	LOCK(extMutex);
+	last = extension;
+
+	while(last->next)
+		last = last->next;
+
+	last->next = rfbExtensionHead;
+	rfbExtensionHead = extension;
+	UNLOCK(extMutex);
+}
+
+rfbProtocolExtension* rfbGetExtensionIterator()
+{
+	LOCK(extMutex);
+	return rfbExtensionHead;
+}
+
+void rfbReleaseExtensionIterator()
+{
+	UNLOCK(extMutex);
+}
+
+/*
+ * Logging
+ */
+
 void rfbLogEnable(int enabled) {
   rfbEnableLogging=enabled;
 }

libvncserver/rfbserver.c

@@ -3,6 +3,7 @@
  */
 
 /*
+ *  Copyright (C) 2005 Rohit Kumar, Johannes E. Schindelin
  *  Copyright (C) 2002 RealVNC Ltd.
  *  OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
  *  Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.  
@@ -347,6 +348,8 @@ rfbNewTCPOrUDPClient(rfbScreenInfoPtr rfbScreen,
 
       cl->progressiveSliceY = 0;
 
+      cl->extensions = NULL;
+
       sprintf(pv,rfbProtocolVersionFormat,rfbProtocolMajorVersion,
 	      rfbProtocolMinorVersion);
 
@@ -603,6 +606,7 @@ rfbProcessClientInitMessage(rfbClientPtr cl)
     int len, n;
     rfbClientIteratorPtr iterator;
     rfbClientPtr otherCl;
+    rfbProtocolExtension* extension;
 
     if ((n = rfbReadExact(cl, (char *)&ci,sz_rfbClientInitMsg)) <= 0) {
         if (n == 0)
@@ -613,7 +617,7 @@ rfbProcessClientInitMessage(rfbClientPtr cl)
         return;
     }
 
-    memset(buf,0,256);
+    memset(buf,0,sizeof(buf));
 
     si->framebufferWidth = Swap16IfLE(cl->screen->width);
     si->framebufferHeight = Swap16IfLE(cl->screen->height);
@@ -632,6 +636,19 @@ rfbProcessClientInitMessage(rfbClientPtr cl)
         return;
     }
 
+    for(extension=rfbGetExtensionIterator();extension;extension=extension->next)
+	if(extension->init) {
+	    void* data;
+	    if(extension->init(cl, &data)) {
+		rfbExtensionData* extensionData=calloc(sizeof(rfbExtensionData),1);
+		extensionData->extension=extension;
+		extensionData->data=data;
+		extensionData->next=cl->extensions;
+		cl->extensions=extensionData;
+	    }
+	}
+    rfbReleaseExtensionIterator();
+
     cl->state = RFB_NORMAL;
 
     if (!cl->reverseConnection &&
@@ -1046,16 +1063,28 @@ rfbProcessClientNormalMessage(rfbClientPtr cl)
 
 
     default:
+	{
+	    rfbExtensionData* extension;
 
-	if(cl->screen->processCustomClientMessage(cl,msg.type))
+	    for(extension=cl->extensions; extension; extension=extension->next)
+		if(extension->extension->handleMessage &&
+			extension->extension->handleMessage(cl, extension->data, msg))
 		    return;
 
+	    if(cl->screen->processCustomClientMessage(cl,msg.type)) {
+		rfbLog("Warning: this program uses processCustomClientMessage, "
+			"which is deprecated.\n"
+			"Please use rfbRegisterProtocolExtension instead.\n");
+		return;
+	    }
+
 	    rfbLog("rfbProcessClientNormalMessage: unknown message type %d\n",
 		    msg.type);
 	    rfbLog(" ... closing connection\n");
 	    rfbCloseClient(cl);
 	    return;
 	}
+    }
 }
 
 

libvncserver/sockets.c

@@ -19,6 +19,7 @@
  */
 
 /*
+ *  Copyright (C) 2005 Rohit Kumar, Johannes E. Schindelin
  *  OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
  *  Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.  
  *  All Rights Reserved.
@@ -344,6 +345,12 @@ rfbDisconnectUDPSock(rfbScreenInfoPtr rfbScreen)
 void
 rfbCloseClient(rfbClientPtr cl)
 {
+    rfbExtensionData* extension;
+
+    for(extension=cl->extensions; extension; extension=extension->next)
+	if(extension->extension->close)
+	    extension->extension->close(cl, extension->data);
+
     LOCK(cl->updateMutex);
 #ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
     if (cl->sock != -1)

rfb/rfb.h

@@ -145,7 +145,7 @@ typedef struct {
 } rfbColourMap;
 
 /*
- *  Security handling (RFB protocol version 3.7
+ * Security handling (RFB protocol version 3.7)
  */
 
 typedef struct _rfbSecurity {
@@ -154,6 +154,29 @@ typedef struct _rfbSecurity {
 	struct _rfbSecurity* next;
 } rfbSecurityHandler;
 
+/*
+ * Protocol extension handling.
+ */
+
+typedef struct _rfbProtocolExtension {
+	/* returns TRUE if extension should be activated */
+	rfbBool (*init)(struct _rfbClientRec* client, void** data);
+	/* returns TRUE if message was handled */
+	rfbBool (*handleMessage)(struct _rfbClientRec* client,
+				void* data,
+				rfbClientToServerMsg message);
+	void (*close)(struct _rfbClientRec* client, void* data);
+	void (*usage)(void);
+	/* processArguments returns the number of handled arguments */
+	int (*processArgument)(char *argv[]);
+	struct _rfbProtocolExtension* next;
+} rfbProtocolExtension;
+
+typedef struct _rfbExtensionData {
+	rfbProtocolExtension* extension;
+	void* data;
+	struct _rfbExtensionData* next;
+} rfbExtensionData;
 
 /*
  * Per-screen (framebuffer) structure.  There can be as many as you wish,
@@ -481,6 +504,8 @@ typedef struct _rfbClientRec {
     /* if progressive updating is on, this variable holds the current
      * y coordinate of the progressive slice. */
     int progressiveSliceY;
+
+    rfbExtensionData* extensions;
 } rfbClientRec, *rfbClientPtr;
 
 /*
@@ -760,6 +785,10 @@ void rfbMarkRectAsModified(rfbScreenInfoPtr rfbScreen,int x1,int y1,int x2,int y
 void rfbMarkRegionAsModified(rfbScreenInfoPtr rfbScreen,sraRegionPtr modRegion);
 void rfbDoNothingWithClient(rfbClientPtr cl);
 enum rfbNewClientAction defaultNewClientHook(rfbClientPtr cl);
+void rfbRegisterProtocolExtension(rfbProtocolExtension* extension);
+struct _rfbProtocolExtension* rfbGetExtensionIterator();
+void rfbReleaseExtensionIterator();
+rfbBool rfbEnableExtension(rfbClientPtr cl, rfbProtocolExtension* extension);
 
 /* to check against plain passwords */
 rfbBool rfbCheckPasswordByList(rfbClientPtr cl,const char* response,int len);