Add own keysym to name function

This is mainly a copy of XKeysymToString() from libX11. We've also added
a wrapper that still gives a string, even if there is no name for the
requested keysym.

This grows the binaries a bit, but not with any extreme amount so is
hopefully worth it to get better debug logging.

common/rfb/CConnection.cxx

@@ -32,6 +32,7 @@
 #include <rfb/CMsgWriter.h>
 #include <rfb/CSecurity.h>
 #include <rfb/Decoder.h>
+#include <rfb/KeysymStr.h>
 #include <rfb/Security.h>
 #include <rfb/SecurityClient.h>
 #include <rfb/CConnection.h>

common/rfb/CMakeLists.txt

@@ -24,6 +24,7 @@ add_library(rfb STATIC
   JpegCompressor.cxx
   JpegDecompressor.cxx
   KeyRemapper.cxx
+  KeysymStr.c
   LogWriter.cxx
   Logger.cxx
   Logger_file.cxx

common/rfb/KeysymStr.c

@@ -0,0 +1,108 @@
+
+/*
+
+Copyright 1990, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+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
+OPEN GROUP 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.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+
+#include "keysymdef.h"
+#include "KeysymStr.h"
+
+#define NEEDKTABLE
+#define NEEDVTABLE
+#include "ks_tables.h"
+
+static const char *_XKeysymToString(unsigned ks)
+{
+    if (!ks || (ks & ((unsigned long) ~0x1fffffff)) != 0)
+	return ((char *)NULL);
+    if (ks == XK_VoidSymbol)
+	ks = 0;
+    if (ks <= 0x1fffffff)
+    {
+	unsigned char val1 = ks >> 24;
+	unsigned char val2 = (ks >> 16) & 0xff;
+	unsigned char val3 = (ks >> 8) & 0xff;
+	unsigned char val4 = ks & 0xff;
+	int i = ks % VTABLESIZE;
+	int h = i + 1;
+	int n = VMAXHASH;
+	int idx;
+	while ((idx = hashKeysym[i]))
+	{
+	    const unsigned char *entry = &_XkeyTable[idx];
+	    if ((entry[0] == val1) && (entry[1] == val2) &&
+                (entry[2] == val3) && (entry[3] == val4))
+		return ((char *)entry + 4);
+	    if (!--n)
+		break;
+	    i += h;
+	    if (i >= VTABLESIZE)
+		i -= VTABLESIZE;
+	}
+    }
+
+    if (ks >= 0x01000100 && ks <= 0x0110ffff) {
+        unsigned val = ks & 0xffffff;
+        char *s;
+        int i;
+        if (val & 0xff0000)
+            i = 10;
+        else
+            i = 6;
+        s = malloc(i);
+        if (s == NULL)
+            return s;
+        i--;
+        s[i--] = '\0';
+        for (; i; i--){
+            unsigned char val1 = val & 0xf;
+            val >>= 4;
+            if (val1 < 10)
+                s[i] = '0'+ val1;
+            else
+                s[i] = 'A'+ val1 - 10;
+        }
+        s[i] = 'U';
+        return s;
+    }
+    return ((char *) NULL);
+}
+
+const char* KeySymName(unsigned keysym)
+{
+    const char* name;
+
+    name = _XKeysymToString(keysym);
+    if (name == NULL)
+      return "[unknown keysym]";
+
+    return name;
+}
+

common/rfb/KeysymStr.h

@@ -0,0 +1,32 @@
+/* Copyright 2021 Pierre Ossman for Cendio AB
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#ifndef __RFB_KEYSYMSTR_H__
+#define __RFB_KEYSYMSTR_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+const char* KeySymName(unsigned keysym);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

common/rfb/VNCSConnectionST.cxx

@@ -28,6 +28,7 @@
 #include <rfb/Encoder.h>
 #include <rfb/Exception.h>
 #include <rfb/KeyRemapper.h>
+#include <rfb/KeysymStr.h>
 #include <rfb/LogWriter.h>
 #include <rfb/Security.h>
 #include <rfb/ServerCore.h>
@@ -89,8 +90,8 @@ VNCSConnectionST::~VNCSConnectionST()
     keycode = pressedKeys.begin()->first;
     pressedKeys.erase(pressedKeys.begin());
 
-    vlog.debug("Releasing key 0x%x / 0x%x on client disconnect",
-               keysym, keycode);
+    vlog.debug("Releasing key 0x%04x / XK_%s (0x%04x) on client disconnect",
+               keycode, KeySymName(keysym), keysym);
     server->keyEvent(keysym, keycode, false);
   }
 
@@ -514,9 +515,11 @@ void VNCSConnectionST::keyEvent(uint32_t keysym, uint32_t keycode, bool down) {
   if (!rfb::Server::acceptKeyEvents) return;
 
   if (down)
-    vlog.debug("Key pressed: 0x%x / 0x%x", keysym, keycode);
+    vlog.debug("Key pressed: 0x%04x / XK_%s (0x%04x)",
+               keycode, KeySymName(keysym), keysym);
   else
-    vlog.debug("Key released: 0x%x / 0x%x", keysym, keycode);
+    vlog.debug("Key released: 0x%04x / XK_%s (0x%04x)",
+               keycode, KeySymName(keysym), keysym);
 
   // Avoid lock keys if we don't know the server state
   if ((server->getLEDState() == ledUnknown) &&

common/rfb/VNCServerST.cxx

@@ -58,6 +58,7 @@
 #include <rfb/ComparingUpdateTracker.h>
 #include <rfb/Exception.h>
 #include <rfb/KeyRemapper.h>
+#include <rfb/KeysymStr.h>
 #include <rfb/LogWriter.h>
 #include <rfb/Security.h>
 #include <rfb/ServerCore.h>
@@ -471,7 +472,8 @@ void VNCServerST::keyEvent(uint32_t keysym, uint32_t keycode, bool down)
     uint32_t newkey;
     newkey = keyRemapper->remapKey(keysym);
     if (newkey != keysym) {
-      slog.debug("Key remapped to 0x%x", newkey);
+      slog.debug("Key remapped to XK_%s (0x%x)",
+                 KeySymName(newkey), newkey);
       keysym = newkey;
     }
   }

unix/xserver/hw/vnc/vncInput.c

@@ -28,6 +28,9 @@
 #include "vncExtInit.h"
 #include "RFBGlue.h"
 
+/* This is a C header, so safe to include */
+#include <rfb/KeysymStr.h>
+
 #include "inputstr.h"
 #include "inpututils.h"
 #include "mi.h"
@@ -404,7 +407,8 @@ static void vncKeysymKeyboardEvent(KeySym keysym, int down)
 		 * This can happen quite often as we ignore some
 		 * key presses.
 		 */
-		LOG_DEBUG("Unexpected release of keysym 0x%x", keysym);
+		LOG_DEBUG("Unexpected release of keysym XK_%s (0x%04x)",
+                          KeySymName(keysym), keysym);
 		return;
 	}
 
@@ -466,12 +470,13 @@ static void vncKeysymKeyboardEvent(KeySym keysym, int down)
 	if (keycode == 0) {
 		keycode = vncAddKeysym(keysym, state);
 		if (keycode == 0) {
-			LOG_ERROR("Failure adding new keysym 0x%x", keysym);
+			LOG_ERROR("Failure adding new keysym XK_%s (0x%x)",
+                                  KeySymName(keysym), keysym);
 			return;
 		}
 
-		LOG_INFO("Added keysym 0x%x to keycode %d",
-		         keysym, keycode);
+		LOG_INFO("Added keysym XK_%s (0x%04x) to keycode %d",
+		         KeySymName(keysym), keysym, keycode);
 
 		/*
 		 * The state given to addKeysym() is just a hint and
@@ -480,7 +485,8 @@ static void vncKeysymKeyboardEvent(KeySym keysym, int down)
 		 */
 		keycode = vncKeysymToKeycode(keysym, state, &new_state);
 		if (keycode == 0) {
-			LOG_ERROR("Newly added keysym 0x%x cannot be generated", keysym);
+			LOG_ERROR("Newly added keysym XK_%s (0x%x) cannot be generated",
+                                  KeySymName(keysym), keysym);
 			return;
 		}
 	}
@@ -501,7 +507,8 @@ static void vncKeysymKeyboardEvent(KeySym keysym, int down)
 	    	KeyCode keycode2;
 	    	unsigned new_state2;
 
-		LOG_DEBUG("Finding alternative to keysym 0x%x to avoid fake shift for numpad", keysym);
+		LOG_DEBUG("Finding alternative to keysym XK_%s (0x%x) to avoid fake shift for numpad",
+                          KeySymName(keysym), keysym);
 
 		for (i = 0;i < sizeof(altKeysym)/sizeof(altKeysym[0]);i++) {
 			KeySym altsym;
@@ -610,7 +617,8 @@ static void vncKeysymKeyboardEvent(KeySym keysym, int down)
 		if (i == keycode)
 			continue;
 		if (pressedKeys[i] == keysym) {
-			LOG_ERROR("Keysym 0x%x generated by both keys %d and %d", keysym, i, keycode);
+			LOG_ERROR("Keysym XK_%s (0x%04x) generated by both keys %d and %d",
+                                  KeySymName(keysym), keysym, i, keycode);
 			pressedKeys[i] = NoSymbol;
 		}
 	}

vncviewer/Viewport.cxx

@@ -28,6 +28,7 @@
 #include <rfb/CMsgWriter.h>
 #include <rfb/LogWriter.h>
 #include <rfb/Exception.h>
+#include <rfb/KeysymStr.h>
 #include <rfb/ledStates.h>
 #include <rfb/util.h>
 
@@ -867,12 +868,8 @@ void Viewport::handleKeyPress(int keyCode, uint32_t keySym)
   // and send the same on release.
   downKeySym[keyCode] = keySym;
 
-#if defined(WIN32) || defined(__APPLE__)
-  vlog.debug("Key pressed: 0x%04x => 0x%04x", keyCode, keySym);
-#else
   vlog.debug("Key pressed: 0x%04x => XK_%s (0x%04x)",
-             keyCode, XKeysymToString(keySym), keySym);
-#endif
+             keyCode, KeySymName(keySym), keySym);
 
   try {
     // Fake keycode?
@@ -902,12 +899,8 @@ void Viewport::handleKeyRelease(int keyCode)
     return;
   }
 
-#if defined(WIN32) || defined(__APPLE__)
-  vlog.debug("Key released: 0x%04x => 0x%04x", keyCode, iter->second);
-#else
   vlog.debug("Key released: 0x%04x => XK_%s (0x%04x)",
-             keyCode, XKeysymToString(iter->second), iter->second);
-#endif
+             keyCode, KeySymName(iter->second), iter->second);
 
   try {
     if (keyCode > 0xff)