Add support for desegmentation of X11 messages.

Try to check whether the first request we see is an initial connection
request, and dissect it as such if so.

Get rid of the global "next_offset" variable.

Check for buffer overflows when building the summary item for a list
of keysyms.

Display BASE_DEC items in decimal, not hex.

svn path=/trunk/; revision=5173

2 files changed, 1501 insertions, 1134 deletions

diff --git a/packet-x11.c b/packet-x11.c
index 6e17e08f1a..b3bb5e816b 100644
--- a/packet-x11.c
+++ b/packet-x11.c
@@ -2,7 +2,7 @@
  * Routines for X11 dissection
  * Copyright 2000, Christophe Tronche <ch.tronche@computer.org>
  *
- * $Id: packet-x11.c,v 1.39 2002/04/15 00:10:26 guy Exp $
+ * $Id: packet-x11.c,v 1.40 2002/04/16 09:42:31 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -27,16 +27,21 @@
 
 /* TODO (in no particular order):
  *
- * - keep track of Atom creation by server to be able to display non predefined atoms
+ * - keep track of Atom creation by server to be able to display
+ *   non-predefined atoms
  * - Idem for keysym <-> keycode ???
  * - Idem for fonts 
- * - Subtree the request ids (that is x11.create-window.window and x11.change-window.window should be 
- *   distinct), and add hidden fields (so we still have x11.window).
- * - add hidden fields so we can have x11.circulate-window in addition to x11.opcode == 13
+ * - Subtree the request ids (that is x11.create-window.window and
+ *   x11.change-window.window should be  distinct), and add hidden fields
+ *   (so we still have x11.window).
+ * - add hidden fields so we can have x11.circulate-window in addition to
+ *   x11.opcode == 13 (but you could match on x11.opcode == "CirculateWindow"
+ *   now)
  * - add hidden fields so we have x11.listOfStuff.length
  * - use a faster scheme that linear list searching for the opcode.
- * - correct display of unicode chars.
- * - Not everything is homogeneous, in particular the handling of items in list is a total mess.
+ * - correct display of Unicode chars.
+ * - Not everything is homogeneous, in particular the handling of items in
+ *   list is a total mess.
  */
 
 /* By the way, I wrote a program to generate every request and test
@@ -60,6 +65,10 @@
 #include <string.h>
 #include <glib.h>
 #include <epan/packet.h>
+#include <epan/conversation.h>
+
+#include "prefs.h"
+#include "packet-frame.h"
 
 #define cVALS(x) (const value_string*)(x)
 
@@ -70,7 +79,6 @@ static int proto_x11 = -1;
 
 /* Initialize the subtree pointers */
 static gint ett_x11 = -1;
-static gint ett_x11_request = -1;
 static gint ett_x11_color_flags = -1;
 static gint ett_x11_list_of_arc = -1;
 static gint ett_x11_arc = -1;
@@ -99,18 +107,32 @@ static gint ett_x11_window_value_mask = -1;
 static gint ett_x11_configure_window_mask = -1;
 static gint ett_x11_keyboard_value_mask = -1;
 
+/* desegmentation of X11 messages */
+static gboolean x11_desegment = TRUE;
+
 static dissector_handle_t data_handle;
 
 #define TCP_PORT_X11			6000
 #define TCP_PORT_X11_2			6001
 #define TCP_PORT_X11_3			6002
 
+/*
+ * Round a length to a multiple of 4 bytes.
+ */
+#define ROUND_LENGTH(n)	((((n) + 3)/4) * 4)
+
 /************************************************************************
  ***                                                                  ***
  ***         E N U M   T A B L E S   D E F I N I T I O N S            ***
  ***                                                                  ***
  ************************************************************************/
 
+static const value_string byte_order_vals[] = {
+     { 'B', "Big-endian" },
+     { 'l', "Little-endian" },
+     { 0,   NULL }
+};
+
 static const value_string access_mode_vals[] = {
       { 0, "Disable" },
       { 1, "Enable" },
@@ -604,7 +626,6 @@ static const value_string zero_is_none_vals[] = {
  ***                                                                  ***
  ************************************************************************/
 
-static int next_offset = 0; /* Offset of the next request in the frame */    
 static gboolean little_endian = TRUE;
 
 /************************************************************************
@@ -692,8 +713,8 @@ static gboolean little_endian = TRUE;
 #define LISTofRECTANGLE(name) { listOfRectangle(tvb, offsetp, t, hf_x11_##name, (next_offset - *offsetp) / 8); }
 #define LISTofSEGMENT(name) { listOfSegment(tvb, offsetp, t, hf_x11_##name, (next_offset - *offsetp) / 8); }
 #define LISTofSTRING8(name, length) { listOfString8(tvb, offsetp, t, hf_x11_##name, hf_x11_##name##_string, (length)); }
-#define LISTofTEXTITEM8(name) { listOfTextItem(tvb, offsetp, t, hf_x11_##name, FALSE); }
-#define LISTofTEXTITEM16(name) { listOfTextItem(tvb, offsetp, t, hf_x11_##name, TRUE); }
+#define LISTofTEXTITEM8(name) { listOfTextItem(tvb, offsetp, t, hf_x11_##name, FALSE, next_offset); }
+#define LISTofTEXTITEM16(name) { listOfTextItem(tvb, offsetp, t, hf_x11_##name, TRUE, next_offset); }
 #define OPCODE()       { opcode = FIELD8(opcode); }
 #define PIXMAP(name)   { FIELD32(name); }
 #define REQUEST_LENGTH() (requestLength(tvb, offsetp, t))
@@ -852,22 +873,13 @@ static void listOfAtom(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
 {
       proto_item *ti = proto_tree_add_item(t, hf, tvb, *offsetp, length * 4, little_endian);
       proto_tree *tt = proto_item_add_subtree(ti, ett_x11_list_of_atom);
-      while(length--) {
-	    if (*offsetp + 4 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
+      while(length--)
 	    atom(tvb, offsetp, tt, hf_x11_properties_item);
-      }
 }
 
 static void listOfByte(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
     int length)
 {
-      if (*offsetp + length > next_offset) {
-	    /* List runs past end of message. */
-	    length = next_offset -  *offsetp;
-      }
       if (length <= 0) length = 1;
       proto_tree_add_item(t, hf, tvb, *offsetp, length, little_endian);
       *offsetp += length;
@@ -879,10 +891,6 @@ static void listOfCard32(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
       proto_item *ti = proto_tree_add_item(t, hf, tvb, *offsetp, length * 4, little_endian);
       proto_tree *tt = proto_item_add_subtree(ti, ett_x11_list_of_card32);
       while(length--) {
-	    if (*offsetp + 4 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    proto_tree_add_uint(tt, hf_item, tvb, *offsetp, 4, VALUE32(tvb, *offsetp));
 	    *offsetp += 4;
       }
@@ -902,10 +910,6 @@ static void listOfColorItem(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
 	    char *bp;
 	    const char *sep;
 
-	    if (*offsetp + 12 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    red = VALUE16(tvb, *offsetp + 4);
 	    green = VALUE16(tvb, *offsetp + 6);
 	    blue = VALUE16(tvb, *offsetp + 8);
@@ -977,10 +981,6 @@ static void listOfKeycode(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
 	    const char **m;
 	    int i;
 
-	    if (*offsetp + 8 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    for(i = 8, m = modifiers; i; i--, m++) {
 		u_char c = tvb_get_guint8(tvb, *offsetp);
 		*offsetp += 1;
@@ -1000,17 +1000,26 @@ static void listOfKeysyms(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
       proto_item *tti;
       proto_tree *ttt;
       int i;
-      char buffer[128];
+      char buffer[128+3+1];
+      int buflen = 128;
+      int nchars;
       char *bp;
 
       while(keycode_count--) {
-	    if (*offsetp + keysyms_per_keycode * 4 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    bp = buffer + sprintf(buffer, "keysyms:");
 	    for(i = 0; i < keysyms_per_keycode; i++) {
-		  bp += sprintf(bp, " %s", keysymString(VALUE32(tvb, *offsetp + i * 4)));
+		  nchars = snprintf(bp, buflen, " %s", keysymString(VALUE32(tvb, *offsetp + i * 4)));
+		  if (nchars == -1 || nchars > buflen) {
+			/*
+			 * Some versions of snprintf return -1 if they'd
+			 * truncate the output.
+			 */
+			strcpy(bp, "...");
+			bp += 3;
+			break;
+		  }
+		  bp += nchars;
+		  buflen -= nchars;
 	    }
 	    *bp = '\0';
 	    tti = proto_tree_add_none_format(tt, hf_item, tvb, *offsetp, keysyms_per_keycode * 4,
@@ -1034,10 +1043,6 @@ static void listOfPoint(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf, int
 	    proto_item *tti;
 	    proto_tree *ttt;
 
-	    if (*offsetp + 4 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    x = VALUE16(tvb, *offsetp);
 	    y = VALUE16(tvb, *offsetp + 2);
 
@@ -1061,10 +1066,6 @@ static void listOfRectangle(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
 	    proto_item *tti;
 	    proto_tree *ttt;
 
-	    if (*offsetp + 8 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    x = VALUE16(tvb, *offsetp);
 	    y = VALUE16(tvb, *offsetp + 2);
 	    width = VALUE16(tvb, *offsetp + 4);
@@ -1094,10 +1095,6 @@ static void listOfSegment(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
 	    proto_item *tti;
 	    proto_tree *ttt;
 
-	    if (*offsetp + 8 > next_offset) {
-		/* List runs past end of message. */
-		return;
-	    }
 	    x1 = VALUE16(tvb, *offsetp);
 	    y1 = VALUE16(tvb, *offsetp + 2);
 	    x2 = VALUE16(tvb, *offsetp + 4);
@@ -1234,7 +1231,7 @@ static void string16_with_buffer_preallocated(tvbuff_t *tvb, proto_tree *t,
 }
 
 static void listOfTextItem(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf,
-    int sizeIs16)
+    int sizeIs16, int next_offset)
 {
       int allocated = 0;
       char *s = NULL;
@@ -1316,7 +1313,9 @@ static guint32 field8(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf)
       if (hfi -> strings)
 	    enumValue = match_strval(v, cVALS(hfi -> strings));
       if (enumValue)
-	    proto_tree_add_uint_format(t, hf, tvb, *offsetp, 1, v, "%s: %u (%s)", nameAsChar, v, enumValue);
+	    proto_tree_add_uint_format(t, hf, tvb, *offsetp, 1, v,
+				       hfi -> display == BASE_DEC ? "%s: %u (%s)" : "%s: 0x%02x (%s)",
+				       nameAsChar, v, enumValue);
       else
 	    proto_tree_add_item(t, hf, tvb, *offsetp, 1, little_endian);
       *offsetp += 1;
@@ -1341,7 +1340,9 @@ static guint32 field32(tvbuff_t *tvb, int *offsetp, proto_tree *t, int hf)
       if (hfi -> strings)
 	    enumValue = match_strval(v, cVALS(hfi -> strings));
       if (enumValue)
-	    proto_tree_add_uint_format(t, hf, tvb, *offsetp, 4, v, "%s: 0x%08x (%s)", nameAsChar, v, enumValue);
+	    proto_tree_add_uint_format(t, hf, tvb, *offsetp, 4, v,
+				       hfi -> display == BASE_DEC ? "%s: %u (%s)" : "%s: 0x%08x (%s)",
+				       nameAsChar, v, enumValue);
       else
 	    proto_tree_add_uint_format(t, hf, tvb, *offsetp, 4, v, 
 				       hfi -> display == BASE_DEC ? "%s: %u" : "%s: 0x%08x",
@@ -1596,1019 +1597,46 @@ static void windowAttributes(tvbuff_t *tvb, int *offsetp, proto_tree *t)
       ENDBITMASK;
 }
 
-/************************************************************************
- ***                                                                  ***
- ***              D E C O D I N G   O N E   P A C K E T               ***
- ***                                                                  ***
- ************************************************************************/
+/*
+ * Data structure associated with a conversation; keeps track of the
+ * request for which we're expecting a reply, the frame number of
+ * the initial connection request, and the byte order of the connection.
+ *
+ * An opcode of -3 means we haven't yet seen any requests yet.
+ * An opcode of -2 means we're not expecting a reply.
+ * An opcode of -1 means means we're waiting for a reply to the initial
+ * connection request.
+ * Other values are the opcode of the request for which we're expecting
+ * a reply.
+ *
+ * XXX - assumes only one outstanding request is awaiting a reply,
+ * which should always be the case.
+ */
+#define NOTHING_SEEN		-3
+#define NOTHING_EXPECTED	-2
+#define INITIAL_CONN		-1
 
-static int dissect_x11_requests_loop(tvbuff_t *tvb, int *offsetp, proto_tree *root)
-{
-      int left = tvb_reported_length(tvb), nextLeft;
-      proto_item *ti;
-      proto_tree *t;
-      guint8 v8, v8_2;
-      guint16 v16;
-      guint32 v32;
+#define BYTE_ORDER_BE		0
+#define BYTE_ORDER_LE		1
+#define BYTE_ORDER_UNKNOWN	-1
 
-      /* The X11 data stream to the server is just a sequence of requests,
-         each of which contains a length; for now, we dissect all the
-	 requests in this frame until we run out of data in the frame.
-	 Eventually, we should handle requests that cross frame
-	 boundaries.
-
-	 Note that "in this frame" refers to everything in the frame
-	 as it appeared in the wire, not as it was captured; we want
-	 an exception to be thrown if we go past the end of the
-	 captured data in the frame without going past the end of the
-	 data in the frame. */
-      for(;;) {
-	    int length, opcode;
-	    
-	    /* fprintf(stderr, "Starting loop, left = %d, *offsetp = %d\n", left, *offsetp); */
-	    if (left < 4) {
-		/* We ran out of data - we don't have enough data in
-		   the frame to get the length of this request. */
-		break;
-	    }
-	    length = VALUE16(tvb, *offsetp + 2) * 4;
-	    /*	    fprintf(stderr, "length = %d\n", length);*/
-	    if (left < length) {
-		/* We ran out of data - we don't have enough data in
-		   the frame for the full request. */
-		break;
-	    }
-	    if (length < 4) {
-	    	/* Bogus message length? */
-		break;
-	    }
+typedef struct {
+      int	opcode;		/* opcode for which we're awaiting a reply */
+      guint32	iconn_frame;	/* frame # of initial connection request */
+      int	byte_order;	/* byte order of connection */
+} x11_conv_data_t;
 
-	    next_offset = *offsetp + length;
-	    nextLeft = left - length;
-
-	    ti = proto_tree_add_uint(root, hf_x11_request, tvb, *offsetp, length, tvb_get_guint8(tvb, *offsetp));
-	    t = proto_item_add_subtree(ti, ett_x11_request);
-
-	    OPCODE();
-
-	    switch(opcode) {
-		case 1: /* CreateWindow */
-		  CARD8(depth);
-		  REQUEST_LENGTH();
-		  WINDOW(wid);
-		  WINDOW(parent);
-		  INT16(x);
-		  INT16(y);
-		  CARD16(width);
-		  CARD16(height);
-		  CARD16(border_width);
-		  ENUM16(window_class);
-		  VISUALID(visual);
-		  windowAttributes(tvb, offsetp, t);
-		  break;
-
-		case 2: /* ChangeWindowAttributes */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  windowAttributes(tvb, offsetp, t);
-		  break;
-
-		case 3: /* GetWindowAttributes */
-		case 4: /* DestroyWindow */
-		case 5: /* DestroySubwindows */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 6: /* ChangeSaveSet */
-		  ENUM8(save_set_mode);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 7: /* ReparentWindow */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  WINDOW(parent);
-		  INT16(x);
-		  INT16(y);
-		  break;
-
-		case 8: /* MapWindow */
-		case 9: /* MapSubWindow */
-		case 10: /* UnmapWindow */
-		case 11: /* UnmapSubwindows */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 12: /* ConfigureWindow */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  BITMASK16(configure_window);
-		  UNUSED(2); 
-		  BITFIELD(INT16,  configure_window_mask, x);
-		  BITFIELD(INT16,  configure_window_mask, y);
-		  BITFIELD(CARD16, configure_window_mask, width);
-		  BITFIELD(CARD16, configure_window_mask, height);
-		  BITFIELD(CARD16, configure_window_mask, border_width);
-		  BITFIELD(WINDOW, configure_window_mask, sibling);
-		  BITFIELD(ENUM8,  configure_window_mask, stack_mode);
-		  ENDBITMASK;
-		  PAD();
-		  break;
-
-		case 13: /* CirculateWindow */
-		  ENUM8(direction);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 14: /* GetGeometry */
-		case 15: /* QueryTree */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  break;
-
-		case 16: /* InternAtom */
-		  BOOL(only_if_exists);
-		  REQUEST_LENGTH();
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 17: /* GetAtomName */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  ATOM(atom);
-		  break;
-
-		case 18: /* ChangeProperty */
-		  ENUM8(mode);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  ATOM(property);
-		  ATOM(type);
-		  CARD8(format);
-		  UNUSED(3);
-		  v32 = CARD32(data_length);
-		  LISTofBYTE(data, v32);
-		  PAD();
-		  break;
-
-		case 19: /* DeleteProperty */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  ATOM(property);
-		  break;
-
-		case 20: /* GetProperty */
-		  BOOL(delete);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  ATOM(property);
-		  ATOM(get_property_type);
-		  CARD32(long_offset);
-		  CARD32(long_length);
-		  break;
-
-		case 21: /* ListProperties */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 22: /* SetSelectionOwner */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(owner);
-		  ATOM(selection);
-		  TIMESTAMP(time);
-		  break;
-
-		case 23: /* GetSelectionOwner */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  ATOM(selection);
-		  break;
-
-		case 24: /* ConvertSelection */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(requestor);
-		  ATOM(selection);
-		  ATOM(target);
-		  ATOM(property);
-		  TIMESTAMP(time);
-		  break;
-
-		case 26: /* GrabPointer */
-		  BOOL(owner_events);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  SETofPOINTEREVENT(pointer_event_mask);
-		  ENUM8(pointer_mode);
-		  ENUM8(keyboard_mode);
-		  WINDOW(confine_to);
-		  CURSOR(cursor);
-		  TIMESTAMP(time);
-		  break;
-
-		case 27: /* UngrabPointer */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  TIMESTAMP(time);
-		  break;
-
-		case 28: /* GrabButton */
-		  BOOL(owner_events);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  SETofPOINTEREVENT(event_mask);
-		  ENUM8(pointer_mode);
-		  ENUM8(keyboard_mode);
-		  WINDOW(confine_to);
-		  CURSOR(cursor);
-		  BUTTON(button);
-		  UNUSED(1);
-		  SETofKEYMASK(modifiers);
-		  break;
-
-		case 29: /* UngrabButton */
-		  BUTTON(button);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  SETofKEYMASK(modifiers);
-		  UNUSED(2);
-		  break;
-
-		case 30: /* ChangeActivePointerGrab */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CURSOR(cursor);
-		  TIMESTAMP(time);
-		  SETofPOINTEREVENT(event_mask);
-		  UNUSED(2);
-		  break;
-
-		case 31: /* GrabKeyboard */
-		  BOOL(owner_events);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  TIMESTAMP(time);
-		  ENUM8(pointer_mode);
-		  ENUM8(keyboard_mode);
-		  UNUSED(2);
-		  break;
-
-		case 32: /* UngrabKeyboard */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  TIMESTAMP(time);
-		  break;
-
-		case 33: /* GrabKey */
-		  BOOL(owner_events);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  SETofKEYMASK(modifiers);
-		  KEYCODE(key);
-		  ENUM8(pointer_mode);
-		  ENUM8(keyboard_mode);
-		  UNUSED(3);
-		  break;
-
-		case 34: /* UngrabKey */
-		  KEYCODE(key);
-		  REQUEST_LENGTH();
-		  WINDOW(grab_window);
-		  SETofKEYMASK(modifiers);
-		  UNUSED(2);
-		  break;
-
-		case 35: /* AllowEvents */
-		  ENUM8(allow_events_mode);
-		  REQUEST_LENGTH();
-		  TIMESTAMP(time);
-		  break;
-
-		case 36: /* GrabServer */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 37: /* UngrabServer */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 38: /* QueryPointer */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 39: /* GetMotionEvents */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  TIMESTAMP(start);
-		  TIMESTAMP(stop);
-		  break;
-
-		case 40: /* TranslateCoordinates */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(src_window);
-		  WINDOW(dst_window);
-		  INT16(src_x);
-		  INT16(src_y);
-		  break;
-
-		case 41: /* WarpPointer */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(warp_pointer_src_window);
-		  WINDOW(warp_pointer_dst_window);
-		  INT16(src_x);
-		  INT16(src_y);
-		  CARD16(src_width);
-		  CARD16(src_height);
-		  INT16(dst_x);
-		  INT16(dst_y);
-		  break;
-
-		case 42: /* SetInputFocus */
-		  ENUM8(revert_to);
-		  REQUEST_LENGTH();
-		  WINDOW(focus);
-		  TIMESTAMP(time);
-		  break;
-
-		case 43: /* GetInputFocus */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 44: /* QueryKeymap */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 45: /* OpenFont */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  FONT(fid);
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 46: /* CloseFont */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  FONT(font);
-		  break;
-
-		case 47: /* QueryFont */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  FONTABLE(font);
-		  break;
-
-		case 48: /* QueryTextExtents */
-		  v8 = BOOL(odd_length);
-		  REQUEST_LENGTH();
-		  FONTABLE(font);
-		  STRING16(string16, (next_offset - *offsetp - (v8 ? 2 : 0)) / 2);
-		  PAD();
-		  break;
-
-		case 49: /* ListFonts */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CARD16(max_names);
-		  v16 = FIELD16(pattern_length);
-		  STRING8(pattern, v16);
-		  PAD();
-		  break;
-
-		case 50: /* ListFontsWithInfo */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CARD16(max_names);
-		  v16 = FIELD16(pattern_length);
-		  STRING8(pattern, v16);
-		  PAD();
-		  break;
-
-		case 51: /* SetFontPath */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  v16 = CARD16(str_number_in_path);
-		  UNUSED(2);
-		  LISTofSTRING8(path, v16);
-		  PAD();
-		  break;
-
-		case 52: /* GetFontPath */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 53: /* CreatePixmap */
-		  CARD8(depth);
-		  REQUEST_LENGTH();
-		  PIXMAP(pid);
-		  DRAWABLE(drawable);
-		  CARD16(width);
-		  CARD16(height);
-		  break;
-
-		case 54: /* FreePixmap */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  PIXMAP(pixmap);
-		  break;
-
-		case 55: /* CreateGC */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  GCONTEXT(cid);
-		  DRAWABLE(drawable);
-		  gcAttributes(tvb, offsetp, t);
-		  break;
-
-		case 56: /* ChangeGC */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  GCONTEXT(gc);
-		  gcAttributes(tvb, offsetp, t);
-		  break;
-
-		case 57: /* CopyGC */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  GCONTEXT(src_gc);
-		  GCONTEXT(dst_gc);
-		  gcMask(tvb, offsetp, t);
-		  break;
-
-		case 58: /* SetDashes */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  GCONTEXT(gc);
-		  CARD16(dash_offset);
-		  v16 = FIELD16(dashes_length);
-		  LISTofCARD8(dashes, v16);
-		  PAD();
-		  break;
-
-		case 59: /* SetClipRectangles */
-		  ENUM8(ordering);
-		  REQUEST_LENGTH();
-		  GCONTEXT(gc);
-		  INT16(clip_x_origin);
-		  INT16(clip_y_origin);
-		  LISTofRECTANGLE(rectangles);
-		  break;
-
-		case 60: /* FreeGC */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  GCONTEXT(gc);
-		  break;
-
-		case 61: /* ClearArea */
-		  BOOL(exposures);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  INT16(x);
-		  INT16(y);
-		  CARD16(width);
-		  CARD16(height);
-		  break;
-
-		case 62: /* CopyArea */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(src_drawable);
-		  DRAWABLE(dst_drawable);
-		  GCONTEXT(gc);
-		  INT16(src_x);
-		  INT16(src_y);
-		  INT16(dst_x);
-		  INT16(dst_y);
-		  CARD16(width);
-		  CARD16(height);
-		  break;
-
-		case 63: /* CopyPlane */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(src_drawable);
-		  DRAWABLE(dst_drawable);
-		  GCONTEXT(gc);
-		  INT16(src_x);
-		  INT16(src_y);
-		  INT16(dst_x);
-		  INT16(dst_y);
-		  CARD16(width);
-		  CARD16(height);
-		  CARD32(bit_plane);
-		  break;
-
-		case 64: /* PolyPoint */
-		  ENUM8(coordinate_mode);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofPOINT(points, v16 - 12);
-		  break;
-
-		case 65: /* PolyLine */
-		  ENUM8(coordinate_mode);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofPOINT(points, v16 - 12);
-		  break;
-
-		case 66: /* PolySegment */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofSEGMENT(segments);
-		  break;
-
-		case 67: /* PolyRectangle */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofRECTANGLE(rectangles);
-		  break;
-
-		case 68: /* PolyArc */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofARC(arcs);
-		  break;
-
-		case 69: /* FillPoly */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  ENUM8(shape);
-		  ENUM8(coordinate_mode);
-		  UNUSED(2);
-		  LISTofPOINT(points, v16 - 16);
-		  break;
-
-		case 70: /* PolyFillRectangle */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofRECTANGLE(rectangles);
-		  break;
-
-		case 71: /* PolyFillArc */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  LISTofARC(arcs);
-		  break;
-
-		case 72: /* PutImage */
-		  ENUM8(image_format);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  CARD16(width);
-		  CARD16(height);
-		  INT16(dst_x);
-		  INT16(dst_y);
-		  CARD8(left_pad);
-		  CARD8(depth);
-		  UNUSED(2);
-		  LISTofBYTE(data, v16 - 24);
-		  PAD();
-		  break;
-
-		case 73: /* GetImage */
-		  ENUM8(image_pixmap_format);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  INT16(x);
-		  INT16(y);
-		  CARD16(width);
-		  CARD16(height);
-		  CARD32(plane_mask);
-		  break;
-
-		case 74: /* PolyText8 */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  INT16(x);
-		  INT16(y);
-		  LISTofTEXTITEM8(items);
-		  PAD();
-		  break;
-
-		case 75: /* PolyText16 */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  INT16(x);
-		  INT16(y);
-		  LISTofTEXTITEM16(items);
-		  PAD();
-		  break;
-
-		case 76: /* ImageText8 */
-		  v8 = FIELD8(string_length);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  INT16(x);
-		  INT16(y);
-		  STRING8(string, v8);
-		  PAD();
-		  break;
-
-		case 77: /* ImageText16 */
-		  v8 = FIELD8(string_length);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  GCONTEXT(gc);
-		  INT16(x);
-		  INT16(y);
-		  STRING16(string16, v8);
-		  PAD();
-		  break;
-
-		case 78: /* CreateColormap */
-		  ENUM8(alloc);
-		  REQUEST_LENGTH();
-		  COLORMAP(mid);
-		  WINDOW(window);
-		  VISUALID(visual);
-		  break;
-
-		case 79: /* FreeColormap */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  break;
-
-		case 80: /* CopyColormapAndFree */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(mid);
-		  COLORMAP(src_cmap);
-		  break;
-
-		case 81: /* InstallColormap */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  break;
-
-		case 82: /* UninstallColormap */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  break;
-
-		case 83: /* ListInstalledColormaps */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  WINDOW(window);
-		  break;
-
-		case 84: /* AllocColor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  CARD16(red);
-		  CARD16(green);
-		  CARD16(blue);
-		  UNUSED(2);
-		  break;
-
-		case 85: /* AllocNamedColor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 86: /* AllocColorCells */
-		  BOOL(contiguous);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  CARD16(colors);
-		  CARD16(planes);
-		  break;
-
-		case 87: /* AllocColorPlanes */
-		  BOOL(contiguous);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  CARD16(colors);
-		  CARD16(reds);
-		  CARD16(greens);
-		  CARD16(blues);
-		  break;
-
-		case 88: /* FreeColors */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  CARD32(plane_mask);
-		  LISTofCARD32(pixels, v16 - 12);
-		  break;
-
-		case 89: /* StoreColors */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  LISTofCOLORITEM(color_items, v16 - 8);
-		  break;
-
-		case 90: /* StoreNamedColor */
-		  COLOR_FLAGS(color);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  CARD32(pixel);	
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 91: /* QueryColors */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  LISTofCARD32(pixels, v16 - 8);
-		  break;
-
-		case 92: /* LookupColor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  COLORMAP(cmap);
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 93: /* CreateCursor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CURSOR(cid);
-		  PIXMAP(source_pixmap);
-		  PIXMAP(mask);
-		  CARD16(fore_red);
-		  CARD16(fore_green);
-		  CARD16(fore_blue);
-		  CARD16(back_red);
-		  CARD16(back_green);
-		  CARD16(back_blue);
-		  CARD16(x);
-		  CARD16(y);
-		  break;
-
-		case 94: /* CreateGlyphCursor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CURSOR(cid);
-		  FONT(source_font);
-		  FONT(mask_font);
-		  CARD16(source_char);
-		  CARD16(mask_char);
-		  CARD16(fore_red);
-		  CARD16(fore_green);
-		  CARD16(fore_blue);
-		  CARD16(back_red);
-		  CARD16(back_green);
-		  CARD16(back_blue);
-		  break;
-
-		case 95: /* FreeCursor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CURSOR(cursor);
-		  break;
-
-		case 96: /* RecolorCursor */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CURSOR(cursor);
-		  CARD16(fore_red);
-		  CARD16(fore_green);
-		  CARD16(fore_blue);
-		  CARD16(back_red);
-		  CARD16(back_green);
-		  CARD16(back_blue);
-		  break;
-
-		case 97: /* QueryBestSize */
-		  ENUM8(class);
-		  REQUEST_LENGTH();
-		  DRAWABLE(drawable);
-		  CARD16(width);
-		  CARD16(height);
-		  break;
-
-		case 98: /* QueryExtension */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  v16 = FIELD16(name_length);
-		  UNUSED(2);
-		  STRING8(name, v16);
-		  PAD();
-		  break;
-
-		case 99: /* ListExtensions */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 100: /* ChangeKeyboardMapping */
-		  v8 = FIELD8(keycode_count);
-		  REQUEST_LENGTH();
-		  KEYCODE(first_keycode);
-		  v8_2 = FIELD8(keysyms_per_keycode);
-		  UNUSED(2);
-		  LISTofKEYSYM(keysyms, v8, v8_2);
-		  break;
-
-		case 101: /* GetKeyboardMapping */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  KEYCODE(first_keycode);
-		  FIELD8(count);
-		  UNUSED(2);
-		  break;
-
-		case 102: /* ChangeKeyboardControl */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  BITMASK32(keyboard_value);
-		  BITFIELD(INT8, keyboard_value_mask, key_click_percent);
-		  BITFIELD(INT8, keyboard_value_mask, bell_percent);
-		  BITFIELD(INT16, keyboard_value_mask, bell_pitch);
-		  BITFIELD(INT16, keyboard_value_mask, bell_duration);
-		  BITFIELD(INT16, keyboard_value_mask, led);
-		  BITFIELD(ENUM8, keyboard_value_mask, led_mode);
-		  BITFIELD(KEYCODE, keyboard_value_mask, keyboard_key);
-		  BITFIELD(ENUM8, keyboard_value_mask, auto_repeat_mode);
-		  ENDBITMASK;
-		  break;
-
-		case 103: /* GetKeyboardControl */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 104: /* Bell */
-		  INT8(percent);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 105: /* ChangePointerControl */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  INT16(acceleration_numerator);
-		  INT16(acceleration_denominator);
-		  INT16(threshold);
-		  BOOL(do_acceleration);
-		  BOOL(do_threshold);
-		  break;
-
-		case 106: /* GetPointerControl */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 107: /* SetScreenSaver */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  INT16(timeout);
-		  INT16(interval);
-		  ENUM8(prefer_blanking);
-		  ENUM8(allow_exposures);
-		  UNUSED(2);
-		  break;
-
-		case 108: /* GetScreenSaver */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 109: /* ChangeHosts */
-		  ENUM8(change_host_mode);
-		  REQUEST_LENGTH();
-		  ENUM8(family);
-		  UNUSED(1);
-		  v16 = CARD16(address_length);
-		  LISTofCARD8(address, v16);
-		  break;
-
-		case 110: /* ListHosts */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 111: /* SetAccessControl */
-		  ENUM8(access_mode);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 112: /* SetCloseDownMode */
-		  ENUM8(close_down_mode);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 113: /* KillClient */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  CARD32(resource);
-		  break;
-
-		case 114: /* RotateProperties */
-		  UNUSED(1);
-		  v16 = REQUEST_LENGTH();
-		  WINDOW(window);
-		  CARD16(property_number);
-		  INT16(delta);
-		  LISTofATOM(properties, (v16 - 12));
-		  break;
-
-		case 115: /* ForceScreenSaver */
-		  ENUM8(screen_saver_mode);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 116: /* SetPointerMapping */
-		  v8 = FIELD8(map_length);
-		  REQUEST_LENGTH();
-		  LISTofCARD8(map, v8);
-		  PAD();
-		  break;
-
-		case 117: /* GetPointerMapping */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-
-		case 118: /* SetModifierMapping */
-		  v8 = FIELD8(keycodes_per_modifier);
-		  REQUEST_LENGTH();
-		  LISTofKEYCODE(keycodes, v8);
-		  break;
-
-		case 119: /* GetModifierMapping */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-		  
-		case 127: /* NoOperation */
-		  UNUSED(1);
-		  REQUEST_LENGTH();
-		  break;
-	    }
-	    if (*offsetp < next_offset)
-		  proto_tree_add_item(t, hf_x11_undecoded, tvb, *offsetp, next_offset - *offsetp, little_endian);
-	    *offsetp = next_offset;
-	    left = nextLeft;
-      }
+static GMemChunk *x11_state_chunk = NULL;
 
-      return left;
+static void x11_init_protocol(void)
+{
+      if (x11_state_chunk != NULL)
+	    g_mem_chunk_destroy(x11_state_chunk);
+
+      x11_state_chunk = g_mem_chunk_new("x11_state_chunk",
+					sizeof (x11_conv_data_t),
+					128 * sizeof (x11_conv_data_t),
+					G_ALLOC_ONLY);
 }
 
 /************************************************************************
@@ -2617,22 +1645,6 @@ static int dissect_x11_requests_loop(tvbuff_t *tvb, int *offsetp, proto_tree *ro
  ***                                                                  ***
  ************************************************************************/
 
-static GTree *byte_ordering_cache = NULL;
-static GMemChunk *address_chunk = NULL;
-static GMemChunk *ipv4_chunk = NULL;
-static GMemChunk *ipv6_chunk = NULL;
-
-static gint compareAddresses(gconstpointer aa, gconstpointer bb)
-{
-      const address *a = (const address *)aa;
-      const address *b = (const address *)bb;
-      int c = b -> type - a -> type;
-      if (c) return c;
-      c = b -> len - a -> len;
-      if (c) return c;
-      return memcmp(b -> data, a -> data, a -> len);
-}
-
 /* If we can't guess, we return TRUE (that is little_endian), cause
    I'm developing on a Linux box :-). The (non-)guess isn't cached
    however, so we may have more luck next time. I'm quite conservative
@@ -2915,18 +1927,26 @@ static int x_endian_match(tvbuff_t *tvb, guint16 (*v16)(tvbuff_t *, gint))
 }
 
 static gboolean
-guess_byte_ordering(tvbuff_t *tvb, packet_info *pinfo)
+guess_byte_ordering(tvbuff_t *tvb, packet_info *pinfo,
+		    x11_conv_data_t *state_info)
 {
       /* With X the client gives the byte ordering for the protocol,
 	 and the port on the server tells us we're speaking X. */
 
       int le, be, decision, decisionToCache;
 
-      gboolean is_reply = (pinfo->srcport == pinfo->match_port);
-      address *addr = is_reply ? &pinfo->net_dst : &pinfo->net_src;
-      gint32 cache = GPOINTER_TO_INT(g_tree_lookup(byte_ordering_cache, addr));
-      if (cache) return cache > 0 ? TRUE : FALSE;
-      if (is_reply) return TRUE; /* We don't try to guess on a reply / event for now */
+      if (state_info->byte_order == BYTE_ORDER_BE)
+	    return FALSE;	/* known to be big-endian */
+      else if (state_info->byte_order == BYTE_ORDER_LE)
+	    return TRUE;	/* known to be little-endian */
+
+      if (pinfo->srcport == pinfo->match_port) {
+      	    /*
+      	     * This is a reply or event; we don't try to guess the
+      	     * byte order on it for now.
+      	     */
+	    return TRUE;
+      }
 
       le = x_endian_match(tvb, tvb_get_letohs);
       be = x_endian_match(tvb, tvb_get_ntohs);
@@ -2951,27 +1971,10 @@ guess_byte_ordering(tvbuff_t *tvb, packet_info *pinfo)
 
       decisionToCache = (le < 0 && be > 0) || (le > 0 && be < 0);
       if (decisionToCache) {
-	    /* We encode the decision as 1 for TRUE and -1 for FALSE
-	       to be able to distinguish between FALSE and no value in
-	       the cache when recalling the value.
-	    */
-	    int address_length;
-	    char *address_data;
-	    address *cached;
-	    if (addr -> type == AT_IPv4) {
-		  address_length = 4;
-		  address_data = g_mem_chunk_alloc(ipv4_chunk);
-	    } else if (addr -> type == AT_IPv6) {
-		  address_length = 16;
-		  address_data = g_mem_chunk_alloc(ipv6_chunk);
-	    } else {
-		  address_length = addr -> len;
-		  address_data = g_malloc(address_length);
-	    }
-	    cached = g_mem_chunk_alloc(address_chunk);
-	    memcpy(address_data, addr -> data, address_length);
-	    SET_ADDRESS(cached, addr -> type, addr -> len, address_data);
-	    g_tree_insert(byte_ordering_cache, cached, GINT_TO_POINTER(decision ? 1 : -1));
+	    /*
+	     * Remember the decision.
+	     */
+	    state_info->byte_order = decision ? BYTE_ORDER_LE : BYTE_ORDER_BE;
       }
 	    
       /*
@@ -2983,36 +1986,1386 @@ guess_byte_ordering(tvbuff_t *tvb, packet_info *pinfo)
 
 /************************************************************************
  ***                                                                  ***
- ***         I N I T I A L I Z A T I O N   A N D   M A I N            ***
+ ***              D E C O D I N G   O N E   P A C K E T               ***
  ***                                                                  ***
  ************************************************************************/
 
-static void
-dissect_x11_requests(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+/*
+ * Decode an initial connection request.
+ */
+static void dissect_x11_initial_conn(tvbuff_t *tvb, packet_info *pinfo,
+    proto_tree *tree, x11_conv_data_t *state_info)
 {
-/* Set up structures we will need to add the protocol subtree and manage it */
+      int offset = 0;
+      int *offsetp = &offset;
       proto_item *ti;
-      proto_tree *x11_tree;
-      int offset;
-      int left;
-	
-/* This field shows up as the "Info" column in the display; you should make
-   it, if possible, summarize what's in the packet, so that a user looking
-   at the list of packets can tell what type of packet it is. */
+      proto_tree *t;
+      guint16 auth_proto_name_length, auth_proto_data_length;
+      gint left;
+
+      ti = proto_tree_add_item(tree, proto_x11, tvb, 0, -1, FALSE);
+      t = proto_item_add_subtree(ti, ett_x11);
+
+      CARD8(byte_order);
+      UNUSED(1);
+      CARD16(protocol_major_version);
+      CARD16(protocol_minor_version);
+      auth_proto_name_length = CARD16(authorization_protocol_name_length);
+      auth_proto_data_length = CARD16(authorization_protocol_data_length);
+      UNUSED(2);
+      if (auth_proto_name_length != 0) {
+	    STRING8(authorization_protocol_name, auth_proto_name_length);
+	    offset = ROUND_LENGTH(offset);
+      }
+      if (auth_proto_data_length != 0) {
+	    STRING8(authorization_protocol_data, auth_proto_data_length);
+	    offset = ROUND_LENGTH(offset);
+      }
+      left = tvb_length_remaining(tvb, offset);
+      if (left)
+	    proto_tree_add_item(t, hf_x11_undecoded, tvb, offset, left, little_endian);
+
+      /*
+       * This is the initial connection request...
+       */
+      state_info->iconn_frame = pinfo->fd->num;
+
+      /*
+       * ...and we're expecting a reply to it.
+       */
+      state_info->opcode = INITIAL_CONN;
+}
+
+static void dissect_x11_request(tvbuff_t *tvb, packet_info *pinfo,
+    proto_tree *tree, const char *sep, x11_conv_data_t *state_info)
+{
+      int offset = 0;
+      int *offsetp = &offset;
+      int next_offset;
+      proto_item *ti;
+      proto_tree *t;
+      int length, opcode;
+      guint8 v8, v8_2;
+      guint16 v16;
+      guint32 v32;
+      gint left;
+
+      length = VALUE16(tvb, 2) * 4;
+
+      if (length < 4) {
+	    /* Bogus message length? */
+	    return;
+      }
+
+      next_offset = offset + length;
+
+      ti = proto_tree_add_item(tree, proto_x11, tvb, 0, -1, FALSE);
+      t = proto_item_add_subtree(ti, ett_x11);
+
+      OPCODE();
+
       if (check_col(pinfo->cinfo, COL_INFO)) 
-	    col_set_str(pinfo->cinfo, COL_INFO, "Requests");
+	  col_append_fstr(pinfo->cinfo, COL_INFO, "%s %s", sep,
+			  val_to_str(opcode, opcode_vals, "Unknown (%u)"));
+
+      /*
+       * Does this request expect a reply?
+       */
+      switch(opcode) {
+
+      case 3: /* GetWindowAttributes */
+      case 14: /* GetGeometry */
+      case 15: /* QueryTree */
+      case 16: /* InternAtom */
+      case 17: /* GetAtomName */
+      case 20: /* GetProperty */
+      case 21: /* ListProperties */
+      case 23: /* GetSelectionOwner */
+      case 26: /* GrabPointer */
+      case 31: /* GrabKeyboard */
+      case 38: /* QueryPointer */
+      case 39: /* GetMotionEvents */
+      case 40: /* TranslateCoordinates */
+      case 44: /* QueryKeymap */
+      case 47: /* QueryFont */
+      case 48: /* QueryTextExtents */
+      case 49: /* ListFonts */
+      case 73: /* GetImage */
+      case 83: /* ListInstalledColormaps */
+      case 84: /* AllocColor */
+      case 91: /* QueryColors */
+      case 92: /* LookupColor */
+      case 97: /* QueryBestSize */
+      case 98: /* QueryExtension */
+      case 99: /* ListExtensions */
+      case 101: /* GetKeyboardMapping */
+      case 103: /* GetKeyboardControl */
+      case 106: /* GetPointerControl */
+      case 108: /* GetScreenSaver */
+      case 110: /* ListHosts */
+      case 116: /* SetPointerMapping */
+      case 117: /* GetPointerMapping */
+      case 118: /* SetModifierMapping */
+      case 119: /* GetModifierMapping */
+	    /*
+	     * Those requests expect a reply.
+	     */
+	    state_info->opcode = opcode;
+	    break;
+
+      default:
+	    /*
+	     * No reply is expected from any other request.
+	     */
+	    state_info->opcode = NOTHING_EXPECTED;
+	    break;
+      }
 
-/* In the interest of speed, if "tree" is NULL, don't do any work not
-   necessary to generate protocol tree items. */
       if (!tree) return;
-      ti = proto_tree_add_item(tree, proto_x11, tvb, 0, -1, FALSE);
-      x11_tree = proto_item_add_subtree(ti, ett_x11);
 
-      offset = 0;
-      little_endian = guess_byte_ordering(tvb, pinfo);
-      left = dissect_x11_requests_loop(tvb, &offset, x11_tree);
+      switch(opcode) {
+
+      case 1: /* CreateWindow */
+	    CARD8(depth);
+	    REQUEST_LENGTH();
+	    WINDOW(wid);
+	    WINDOW(parent);
+	    INT16(x);
+	    INT16(y);
+	    CARD16(width);
+	    CARD16(height);
+	    CARD16(border_width);
+	    ENUM16(window_class);
+	    VISUALID(visual);
+	    windowAttributes(tvb, offsetp, t);
+	    break;
+
+      case 2: /* ChangeWindowAttributes */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    windowAttributes(tvb, offsetp, t);
+	    break;
+
+      case 3: /* GetWindowAttributes */
+      case 4: /* DestroyWindow */
+      case 5: /* DestroySubwindows */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 6: /* ChangeSaveSet */
+	    ENUM8(save_set_mode);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 7: /* ReparentWindow */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    WINDOW(parent);
+	    INT16(x);
+	    INT16(y);
+	    break;
+
+      case 8: /* MapWindow */
+      case 9: /* MapSubWindow */
+      case 10: /* UnmapWindow */
+      case 11: /* UnmapSubwindows */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 12: /* ConfigureWindow */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    BITMASK16(configure_window);
+	    UNUSED(2); 
+	    BITFIELD(INT16,  configure_window_mask, x);
+	    BITFIELD(INT16,  configure_window_mask, y);
+	    BITFIELD(CARD16, configure_window_mask, width);
+	    BITFIELD(CARD16, configure_window_mask, height);
+	    BITFIELD(CARD16, configure_window_mask, border_width);
+	    BITFIELD(WINDOW, configure_window_mask, sibling);
+	    BITFIELD(ENUM8,  configure_window_mask, stack_mode);
+	    ENDBITMASK;
+	    PAD();
+	    break;
+
+      case 13: /* CirculateWindow */
+	    ENUM8(direction);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 14: /* GetGeometry */
+      case 15: /* QueryTree */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    break;
+
+      case 16: /* InternAtom */
+	    BOOL(only_if_exists);
+	    REQUEST_LENGTH();
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 17: /* GetAtomName */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    ATOM(atom);
+	    break;
+
+      case 18: /* ChangeProperty */
+	    ENUM8(mode);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    ATOM(property);
+	    ATOM(type);
+	    CARD8(format);
+	    UNUSED(3);
+	    v32 = CARD32(data_length);
+	    LISTofBYTE(data, v32);
+	    PAD();
+	    break;
+
+      case 19: /* DeleteProperty */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    ATOM(property);
+	    break;
+
+      case 20: /* GetProperty */
+	    BOOL(delete);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    ATOM(property);
+	    ATOM(get_property_type);
+	    CARD32(long_offset);
+	    CARD32(long_length);
+	    break;
+
+      case 21: /* ListProperties */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 22: /* SetSelectionOwner */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(owner);
+	    ATOM(selection);
+	    TIMESTAMP(time);
+	    break;
+
+      case 23: /* GetSelectionOwner */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    ATOM(selection);
+	    break;
+
+      case 24: /* ConvertSelection */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(requestor);
+	    ATOM(selection);
+	    ATOM(target);
+	    ATOM(property);
+	    TIMESTAMP(time);
+	    break;
+
+      case 26: /* GrabPointer */
+	    BOOL(owner_events);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    SETofPOINTEREVENT(pointer_event_mask);
+	    ENUM8(pointer_mode);
+	    ENUM8(keyboard_mode);
+	    WINDOW(confine_to);
+	    CURSOR(cursor);
+	    TIMESTAMP(time);
+	    break;
+
+      case 27: /* UngrabPointer */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    TIMESTAMP(time);
+	    break;
+
+      case 28: /* GrabButton */
+	    BOOL(owner_events);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    SETofPOINTEREVENT(event_mask);
+	    ENUM8(pointer_mode);
+	    ENUM8(keyboard_mode);
+	    WINDOW(confine_to);
+	    CURSOR(cursor);
+	    BUTTON(button);
+	    UNUSED(1);
+	    SETofKEYMASK(modifiers);
+	    break;
+
+      case 29: /* UngrabButton */
+	    BUTTON(button);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    SETofKEYMASK(modifiers);
+	    UNUSED(2);
+	    break;
+
+      case 30: /* ChangeActivePointerGrab */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CURSOR(cursor);
+	    TIMESTAMP(time);
+	    SETofPOINTEREVENT(event_mask);
+	    UNUSED(2);
+	    break;
+
+      case 31: /* GrabKeyboard */
+	    BOOL(owner_events);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    TIMESTAMP(time);
+	    ENUM8(pointer_mode);
+	    ENUM8(keyboard_mode);
+	    UNUSED(2);
+	    break;
+
+      case 32: /* UngrabKeyboard */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    TIMESTAMP(time);
+	    break;
+
+      case 33: /* GrabKey */
+	    BOOL(owner_events);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    SETofKEYMASK(modifiers);
+	    KEYCODE(key);
+	    ENUM8(pointer_mode);
+	    ENUM8(keyboard_mode);
+	    UNUSED(3);
+	    break;
+
+      case 34: /* UngrabKey */
+	    KEYCODE(key);
+	    REQUEST_LENGTH();
+	    WINDOW(grab_window);
+	    SETofKEYMASK(modifiers);
+	    UNUSED(2);
+	    break;
+
+      case 35: /* AllowEvents */
+	    ENUM8(allow_events_mode);
+	    REQUEST_LENGTH();
+	    TIMESTAMP(time);
+	    break;
+
+      case 36: /* GrabServer */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 37: /* UngrabServer */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 38: /* QueryPointer */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 39: /* GetMotionEvents */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    TIMESTAMP(start);
+	    TIMESTAMP(stop);
+	    break;
+
+      case 40: /* TranslateCoordinates */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(src_window);
+	    WINDOW(dst_window);
+	    INT16(src_x);
+	    INT16(src_y);
+	    break;
+
+      case 41: /* WarpPointer */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(warp_pointer_src_window);
+	    WINDOW(warp_pointer_dst_window);
+	    INT16(src_x);
+	    INT16(src_y);
+	    CARD16(src_width);
+	    CARD16(src_height);
+	    INT16(dst_x);
+	    INT16(dst_y);
+	    break;
+
+      case 42: /* SetInputFocus */
+	    ENUM8(revert_to);
+	    REQUEST_LENGTH();
+	    WINDOW(focus);
+	    TIMESTAMP(time);
+	    break;
+
+      case 43: /* GetInputFocus */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 44: /* QueryKeymap */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 45: /* OpenFont */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    FONT(fid);
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 46: /* CloseFont */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    FONT(font);
+	    break;
+
+      case 47: /* QueryFont */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    FONTABLE(font);
+	    break;
+
+      case 48: /* QueryTextExtents */
+	    v8 = BOOL(odd_length);
+	    REQUEST_LENGTH();
+	    FONTABLE(font);
+	    STRING16(string16, (next_offset - offset - (v8 ? 2 : 0)) / 2);
+	    PAD();
+	    break;
+
+      case 49: /* ListFonts */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CARD16(max_names);
+	    v16 = FIELD16(pattern_length);
+	    STRING8(pattern, v16);
+	    PAD();
+	    break;
+
+      case 50: /* ListFontsWithInfo */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CARD16(max_names);
+	    v16 = FIELD16(pattern_length);
+	    STRING8(pattern, v16);
+	    PAD();
+	    break;
+
+      case 51: /* SetFontPath */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    v16 = CARD16(str_number_in_path);
+	    UNUSED(2);
+	    LISTofSTRING8(path, v16);
+	    PAD();
+	    break;
+
+      case 52: /* GetFontPath */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 53: /* CreatePixmap */
+	    CARD8(depth);
+	    REQUEST_LENGTH();
+	    PIXMAP(pid);
+	    DRAWABLE(drawable);
+	    CARD16(width);
+	    CARD16(height);
+	    break;
+
+      case 54: /* FreePixmap */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    PIXMAP(pixmap);
+	    break;
+
+      case 55: /* CreateGC */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    GCONTEXT(cid);
+	    DRAWABLE(drawable);
+	    gcAttributes(tvb, offsetp, t);
+	    break;
+
+      case 56: /* ChangeGC */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    GCONTEXT(gc);
+	    gcAttributes(tvb, offsetp, t);
+	    break;
+
+      case 57: /* CopyGC */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    GCONTEXT(src_gc);
+	    GCONTEXT(dst_gc);
+	    gcMask(tvb, offsetp, t);
+	    break;
+
+      case 58: /* SetDashes */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    GCONTEXT(gc);
+	    CARD16(dash_offset);
+	    v16 = FIELD16(dashes_length);
+	    LISTofCARD8(dashes, v16);
+	    PAD();
+	    break;
+
+      case 59: /* SetClipRectangles */
+	    ENUM8(ordering);
+	    REQUEST_LENGTH();
+	    GCONTEXT(gc);
+	    INT16(clip_x_origin);
+	    INT16(clip_y_origin);
+	    LISTofRECTANGLE(rectangles);
+	    break;
+
+      case 60: /* FreeGC */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    GCONTEXT(gc);
+	    break;
+
+      case 61: /* ClearArea */
+	    BOOL(exposures);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    INT16(x);
+	    INT16(y);
+	    CARD16(width);
+	    CARD16(height);
+	    break;
+
+      case 62: /* CopyArea */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(src_drawable);
+	    DRAWABLE(dst_drawable);
+	    GCONTEXT(gc);
+	    INT16(src_x);
+	    INT16(src_y);
+	    INT16(dst_x);
+	    INT16(dst_y);
+	    CARD16(width);
+	    CARD16(height);
+	    break;
+
+      case 63: /* CopyPlane */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(src_drawable);
+	    DRAWABLE(dst_drawable);
+	    GCONTEXT(gc);
+	    INT16(src_x);
+	    INT16(src_y);
+	    INT16(dst_x);
+	    INT16(dst_y);
+	    CARD16(width);
+	    CARD16(height);
+	    CARD32(bit_plane);
+	    break;
+
+      case 64: /* PolyPoint */
+	    ENUM8(coordinate_mode);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofPOINT(points, v16 - 12);
+	    break;
+
+      case 65: /* PolyLine */
+	    ENUM8(coordinate_mode);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofPOINT(points, v16 - 12);
+	    break;
+
+      case 66: /* PolySegment */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofSEGMENT(segments);
+	    break;
+
+      case 67: /* PolyRectangle */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofRECTANGLE(rectangles);
+	    break;
+
+      case 68: /* PolyArc */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofARC(arcs);
+	    break;
+
+      case 69: /* FillPoly */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    ENUM8(shape);
+	    ENUM8(coordinate_mode);
+	    UNUSED(2);
+	    LISTofPOINT(points, v16 - 16);
+	    break;
+
+      case 70: /* PolyFillRectangle */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofRECTANGLE(rectangles);
+	    break;
+
+      case 71: /* PolyFillArc */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    LISTofARC(arcs);
+	    break;
+
+      case 72: /* PutImage */
+	    ENUM8(image_format);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    CARD16(width);
+	    CARD16(height);
+	    INT16(dst_x);
+	    INT16(dst_y);
+	    CARD8(left_pad);
+	    CARD8(depth);
+	    UNUSED(2);
+	    LISTofBYTE(data, v16 - 24);
+	    PAD();
+	    break;
+
+      case 73: /* GetImage */
+	    ENUM8(image_pixmap_format);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    INT16(x);
+	    INT16(y);
+	    CARD16(width);
+	    CARD16(height);
+	    CARD32(plane_mask);
+	    break;
+
+      case 74: /* PolyText8 */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    INT16(x);
+	    INT16(y);
+	    LISTofTEXTITEM8(items);
+	    PAD();
+	    break;
+
+      case 75: /* PolyText16 */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    INT16(x);
+	    INT16(y);
+	    LISTofTEXTITEM16(items);
+	    PAD();
+	    break;
+
+      case 76: /* ImageText8 */
+	    v8 = FIELD8(string_length);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    INT16(x);
+	    INT16(y);
+	    STRING8(string, v8);
+	    PAD();
+	    break;
+
+      case 77: /* ImageText16 */
+	    v8 = FIELD8(string_length);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    GCONTEXT(gc);
+	    INT16(x);
+	    INT16(y);
+	    STRING16(string16, v8);
+	    PAD();
+	    break;
+
+      case 78: /* CreateColormap */
+	    ENUM8(alloc);
+	    REQUEST_LENGTH();
+	    COLORMAP(mid);
+	    WINDOW(window);
+	    VISUALID(visual);
+	    break;
+
+      case 79: /* FreeColormap */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    break;
+
+      case 80: /* CopyColormapAndFree */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(mid);
+	    COLORMAP(src_cmap);
+	    break;
+
+      case 81: /* InstallColormap */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    break;
+
+      case 82: /* UninstallColormap */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    break;
+
+      case 83: /* ListInstalledColormaps */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    WINDOW(window);
+	    break;
+
+      case 84: /* AllocColor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    CARD16(red);
+	    CARD16(green);
+	    CARD16(blue);
+	    UNUSED(2);
+	    break;
+
+      case 85: /* AllocNamedColor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 86: /* AllocColorCells */
+	    BOOL(contiguous);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    CARD16(colors);
+	    CARD16(planes);
+	    break;
+
+      case 87: /* AllocColorPlanes */
+	    BOOL(contiguous);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    CARD16(colors);
+	    CARD16(reds);
+	    CARD16(greens);
+	    CARD16(blues);
+	    break;
+
+      case 88: /* FreeColors */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    CARD32(plane_mask);
+	    LISTofCARD32(pixels, v16 - 12);
+	    break;
+
+      case 89: /* StoreColors */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    LISTofCOLORITEM(color_items, v16 - 8);
+	    break;
+
+      case 90: /* StoreNamedColor */
+	    COLOR_FLAGS(color);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    CARD32(pixel);	
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 91: /* QueryColors */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    LISTofCARD32(pixels, v16 - 8);
+	    break;
+
+      case 92: /* LookupColor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    COLORMAP(cmap);
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 93: /* CreateCursor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CURSOR(cid);
+	    PIXMAP(source_pixmap);
+	    PIXMAP(mask);
+	    CARD16(fore_red);
+	    CARD16(fore_green);
+	    CARD16(fore_blue);
+	    CARD16(back_red);
+	    CARD16(back_green);
+	    CARD16(back_blue);
+	    CARD16(x);
+	    CARD16(y);
+	    break;
+
+      case 94: /* CreateGlyphCursor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CURSOR(cid);
+	    FONT(source_font);
+	    FONT(mask_font);
+	    CARD16(source_char);
+	    CARD16(mask_char);
+	    CARD16(fore_red);
+	    CARD16(fore_green);
+	    CARD16(fore_blue);
+	    CARD16(back_red);
+	    CARD16(back_green);
+	    CARD16(back_blue);
+	    break;
+
+      case 95: /* FreeCursor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CURSOR(cursor);
+	    break;
+
+      case 96: /* RecolorCursor */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CURSOR(cursor);
+	    CARD16(fore_red);
+	    CARD16(fore_green);
+	    CARD16(fore_blue);
+	    CARD16(back_red);
+	    CARD16(back_green);
+	    CARD16(back_blue);
+	    break;
+
+      case 97: /* QueryBestSize */
+	    ENUM8(class);
+	    REQUEST_LENGTH();
+	    DRAWABLE(drawable);
+	    CARD16(width);
+	    CARD16(height);
+	    break;
+
+      case 98: /* QueryExtension */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    v16 = FIELD16(name_length);
+	    UNUSED(2);
+	    STRING8(name, v16);
+	    PAD();
+	    break;
+
+      case 99: /* ListExtensions */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 100: /* ChangeKeyboardMapping */
+	    v8 = FIELD8(keycode_count);
+	    REQUEST_LENGTH();
+	    KEYCODE(first_keycode);
+	    v8_2 = FIELD8(keysyms_per_keycode);
+	    UNUSED(2);
+	    LISTofKEYSYM(keysyms, v8, v8_2);
+	    break;
+
+      case 101: /* GetKeyboardMapping */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    KEYCODE(first_keycode);
+	    FIELD8(count);
+	    UNUSED(2);
+	    break;
+
+      case 102: /* ChangeKeyboardControl */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    BITMASK32(keyboard_value);
+	    BITFIELD(INT8, keyboard_value_mask, key_click_percent);
+	    BITFIELD(INT8, keyboard_value_mask, bell_percent);
+	    BITFIELD(INT16, keyboard_value_mask, bell_pitch);
+	    BITFIELD(INT16, keyboard_value_mask, bell_duration);
+	    BITFIELD(INT16, keyboard_value_mask, led);
+	    BITFIELD(ENUM8, keyboard_value_mask, led_mode);
+	    BITFIELD(KEYCODE, keyboard_value_mask, keyboard_key);
+	    BITFIELD(ENUM8, keyboard_value_mask, auto_repeat_mode);
+	    ENDBITMASK;
+	    break;
+
+      case 103: /* GetKeyboardControl */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 104: /* Bell */
+	    INT8(percent);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 105: /* ChangePointerControl */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    INT16(acceleration_numerator);
+	    INT16(acceleration_denominator);
+	    INT16(threshold);
+	    BOOL(do_acceleration);
+	    BOOL(do_threshold);
+	    break;
+
+      case 106: /* GetPointerControl */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 107: /* SetScreenSaver */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    INT16(timeout);
+	    INT16(interval);
+	    ENUM8(prefer_blanking);
+	    ENUM8(allow_exposures);
+	    UNUSED(2);
+	    break;
+
+      case 108: /* GetScreenSaver */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 109: /* ChangeHosts */
+	    ENUM8(change_host_mode);
+	    REQUEST_LENGTH();
+	    ENUM8(family);
+	    UNUSED(1);
+	    v16 = CARD16(address_length);
+	    LISTofCARD8(address, v16);
+	    break;
+
+      case 110: /* ListHosts */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 111: /* SetAccessControl */
+	    ENUM8(access_mode);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 112: /* SetCloseDownMode */
+	    ENUM8(close_down_mode);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 113: /* KillClient */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    CARD32(resource);
+	    break;
+
+      case 114: /* RotateProperties */
+	    UNUSED(1);
+	    v16 = REQUEST_LENGTH();
+	    WINDOW(window);
+	    CARD16(property_number);
+	    INT16(delta);
+	    LISTofATOM(properties, (v16 - 12));
+	    break;
+
+      case 115: /* ForceScreenSaver */
+	    ENUM8(screen_saver_mode);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 116: /* SetPointerMapping */
+	    v8 = FIELD8(map_length);
+	    REQUEST_LENGTH();
+	    LISTofCARD8(map, v8);
+	    PAD();
+	    break;
+
+      case 117: /* GetPointerMapping */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+
+      case 118: /* SetModifierMapping */
+	    v8 = FIELD8(keycodes_per_modifier);
+	    REQUEST_LENGTH();
+	    LISTofKEYCODE(keycodes, v8);
+	    break;
+
+      case 119: /* GetModifierMapping */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+	    
+      case 127: /* NoOperation */
+	    UNUSED(1);
+	    REQUEST_LENGTH();
+	    break;
+      }
+      left = tvb_length_remaining(tvb, offset);
       if (left)
-	    call_dissector(data_handle, tvb_new_subset(tvb, offset,-1, tvb_reported_length_remaining(tvb, offset)), pinfo, x11_tree);
+	    proto_tree_add_item(t, hf_x11_undecoded, tvb, offset, left, little_endian);
+}
+
+static void dissect_x11_requests(tvbuff_t *tvb, packet_info *pinfo,
+    proto_tree *tree)
+{
+      volatile int offset = 0;
+      int length_remaining;
+      guint8 opcode;
+      volatile int plen;
+      proto_item *ti;
+      proto_tree *t;
+      volatile gboolean is_initial_creq;
+      guint16 auth_proto_len, auth_data_len;
+      const char *volatile sep = NULL;
+      conversation_t *conversation;
+      x11_conv_data_t *volatile state_info;
+      int byte_order;
+      int length;
+      tvbuff_t *next_tvb;
+
+      while (tvb_reported_length_remaining(tvb, offset) != 0) {
+	    length_remaining = tvb_length_remaining(tvb, offset);
+
+	    /*
+	     * Can we do reassembly?
+	     */
+	    if (x11_desegment && pinfo->can_desegment) {
+		  /*
+		   * Yes - is the X11 request header split across
+		   * segment boundaries?
+		   */
+		  if (length_remaining < 4) {
+			/*
+			 * Yes.  Tell the TCP dissector where the data
+			 * for this message starts in the data it handed
+			 * us, and how many more bytes we need, and return.
+			 */
+			pinfo->desegment_offset = offset;
+			pinfo->desegment_len = 4 - length_remaining;
+			return;
+		  }
+	    }
+
+	    /*
+	     * Get the state for this conversation; create the conversation
+	     * if we don't have one, and create the state if we don't have
+	     * any.
+	     */
+	    conversation = find_conversation(&pinfo->src, &pinfo->dst,
+		pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
+	    if (conversation == NULL) {
+		  /*
+		   * No - create one.
+		   */
+		  conversation = conversation_new(&pinfo->src,
+			&pinfo->dst, pinfo->ptype, pinfo->srcport,
+			pinfo->destport, 0);
+	    }
+
+	    /*
+	     * Is there state attached to this conversation?
+	     */
+	    state_info = conversation_get_proto_data(conversation, proto_x11);
+	    if (state_info == NULL) {
+		  /*
+		   * No - create a state structure and attach it.
+		   */
+		  state_info = g_mem_chunk_alloc(x11_state_chunk);
+		  state_info->opcode = NOTHING_SEEN;	/* nothing seen yet */
+		  state_info->iconn_frame = 0;	/* don't know it yet */
+		  state_info->byte_order = BYTE_ORDER_UNKNOWN;	/* don't know it yet */
+		  conversation_add_proto_data(conversation, proto_x11,
+			state_info);
+	    }
+
+	    /*
+	     * Guess the byte order if we don't already know it.
+	     */
+	    little_endian = guess_byte_ordering(tvb, pinfo, state_info);
+
+	    /*
+	     * Get the opcode and length of the putative X11 request.
+	     */
+	    opcode = VALUE8(tvb, 0);
+	    plen = VALUE16(tvb, offset + 2);
+
+	    if (plen == 0) {
+		  /*
+		   * This can't be 0, as it includes the header length.
+		   * A different choice of byte order wouldn't have
+		   * helped.
+		   * Give up.
+		   */
+		  ti = proto_tree_add_item(tree, proto_x11, tvb, offset, -1, FALSE);
+		  t = proto_item_add_subtree(ti, ett_x11);
+		  proto_tree_add_text(t, tvb, offset, -1, "Bogus request length (0)");
+		  return;
+	    }
+
+	    if (state_info->iconn_frame == pinfo->fd->num ||
+		(state_info->opcode == NOTHING_SEEN &&
+	         (opcode == 'B' || opcode == 'l') &&
+	         (plen == 11 || plen == 2816))) {
+		  /*
+		   * Either
+		   *
+		   *	we saw this on the first pass and this is
+		   *    it again
+		   *
+		   * or
+		   *    we haven't already seen any requests, the first
+		   *    byte of the message is 'B' or 'l', and the 16-bit
+		   *    integer 2 bytes into the data stream is either 11
+		   *    or a byte-swapped 11.
+		   *
+		   * This means it's probably an initial connection
+		   * request, not a message.
+		   *
+		   * 'B' is decimal 66, which is the opcode for a
+		   * PolySegment request; unfortunately, 11 is a valid
+		   * length for a PolySegment request request, so we
+		   * might mis-identify that request.  (Are there any
+		   * other checks we can do?)
+		   *
+		   * 'l' is decimal 108, which is the opcode for a
+		   * GetScreenSaver request; the only valid length
+		   * for that request is 1.
+		   */
+		  is_initial_creq = TRUE;
+
+		  /*
+		   * We now know the byte order.  Override the guess.
+		   */
+		  if (state_info->byte_order == BYTE_ORDER_UNKNOWN) {
+		  	if (opcode == 'B') {
+			      /*
+			       * Big-endian.
+			       */
+			      state_info->byte_order = BYTE_ORDER_BE;
+			      little_endian = FALSE;
+			} else {
+			      /*
+			       * Little-endian.
+			       */
+			      state_info->byte_order = BYTE_ORDER_LE;
+			      little_endian = TRUE;
+			}
+		  }
+
+		  /*
+		   * Can we do reassembly?
+		   */
+		  if (x11_desegment && pinfo->can_desegment) {
+			/*
+			 * Yes - is the fixed-length portion of the
+			 * initial connection header split across
+			 * segment boundaries?
+			 */
+			if (length_remaining < 10) {
+			      /*
+			       * Yes.  Tell the TCP dissector where the
+			       * data for this message starts in the data
+			       * it handed us, and how many more bytes we
+			       * need, and return.
+			       */
+			      pinfo->desegment_offset = offset;
+			      pinfo->desegment_len = 10 - length_remaining;
+			      return;
+			}
+		  }
+
+		  /*
+		   * Get the lengths of the authorization protocol and
+		   * the authorization data.
+		   */
+		  auth_proto_len = VALUE16(tvb, offset + 6);
+		  auth_data_len = VALUE16(tvb, offset + 8);
+		  plen = 12 + ROUND_LENGTH(auth_proto_len) +
+			ROUND_LENGTH(auth_data_len);
+	    } else {
+		  /*
+		   * This is probably an ordinary request.
+		   */
+		  is_initial_creq = FALSE;
+
+		  /*
+		   * The length of a request is in 4-byte words.
+		   */
+		  plen *= 4;
+	    }
+
+	    /*
+	     * Can we do reassembly?
+	     */
+	    if (x11_desegment && pinfo->can_desegment) {
+		  /*
+		   * Yes - is the X11 request split across segment
+		   * boundaries?
+		   */
+		  if (length_remaining < plen) {
+			/*
+			 * Yes.  Tell the TCP dissector where the data
+			 * for this message starts in the data it handed
+			 * us, and how many more bytes we need, and return.
+			 */
+			pinfo->desegment_offset = offset;
+			pinfo->desegment_len = plen - length_remaining;
+			return;
+		  }
+	    }
+
+	    /*
+	     * Construct a tvbuff containing the amount of the payload
+	     * we have available.  Make its reported length the
+	     * amount of data in the X11 request.
+	     *
+	     * XXX - if reassembly isn't enabled. the subdissector
+	     * will throw a BoundsError exception, rather than a
+	     * ReportedBoundsError exception.  We really want a tvbuff
+	     * where the length is "length", the reported length is "plen",
+	     * and the "if the snapshot length were infinite" length is the
+	     * minimum of the reported length of the tvbuff handed to us
+	     * and "plen", with a new type of exception thrown if the offset
+	     * is within the reported length but beyond that third length,
+	     * with that exception getting the "Unreassembled Packet" error.
+	     */
+	    length = length_remaining;
+	    if (length > plen)
+		  length = plen;
+	    next_tvb = tvb_new_subset(tvb, offset, length, plen);
+
+	    /*
+	     * Set the column appropriately.
+	     */
+	    if (is_initial_creq) {
+		  if (check_col(pinfo->cinfo, COL_INFO)) 
+			col_set_str(pinfo->cinfo, COL_INFO, "Initial connection request");
+	    } else {
+		  if (sep == NULL) {
+			/*
+			 * We haven't set the column yet; set it.
+			 */
+			if (check_col(pinfo->cinfo, COL_INFO)) 
+			      col_add_str(pinfo->cinfo, COL_INFO, "Requests");
+
+			/*
+			 * Initialize the separator.
+			 */
+			sep = ":";
+		  }
+	    }
+
+	    /*
+	     * Dissect the X11 request.
+	     *
+	     * Catch the ReportedBoundsError exception; if this
+	     * particular message happens to get a ReportedBoundsError
+	     * exception, that doesn't mean that we should stop
+	     * dissecting X11 requests within this frame or chunk of
+	     * reassembled data.
+	     *
+	     * If it gets a BoundsError, we can stop, as there's nothing
+	     * more to see, so we just re-throw it.
+	     */
+	    TRY {
+		  if (is_initial_creq) {
+			dissect_x11_initial_conn(next_tvb, pinfo, tree,
+			    state_info);
+		  } else {
+			dissect_x11_request(next_tvb, pinfo, tree, sep,
+			    state_info);
+		  }
+	    }
+	    CATCH(BoundsError) {
+		  RETHROW;
+	    }
+	    CATCH(ReportedBoundsError) {
+		  show_reported_bounds_error(tvb, pinfo, tree);
+	    }
+	    ENDTRY;
+
+	    /*
+	     * Skip the X11 message.
+	     */
+	    offset += plen;
+
+	    sep = ",";
+      }
 }
 
 static void
@@ -3040,6 +3393,12 @@ dissect_x11_replies(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       call_dissector(data_handle,tvb, pinfo, x11_tree);
 }
 
+/************************************************************************
+ ***                                                                  ***
+ ***         I N I T I A L I Z A T I O N   A N D   M A I N            ***
+ ***                                                                  ***
+ ************************************************************************/
+
 static void
 dissect_x11(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
@@ -3071,7 +3430,6 @@ void proto_register_x11(void)
 /* Setup protocol subtree array */
       static gint *ett[] = {
 	    &ett_x11,
-	    &ett_x11_request,
 	    &ett_x11_color_flags,
 	    &ett_x11_list_of_arc,
 	    &ett_x11_arc,
@@ -3100,6 +3458,7 @@ void proto_register_x11(void)
 	    &ett_x11_configure_window_mask,
 	    &ett_x11_keyboard_value_mask,
       };
+      module_t *x11_module;
 
 /* Register the protocol name and description */
       proto_x11 = proto_register_protocol("X11", "X11", "x11");
@@ -3108,13 +3467,14 @@ void proto_register_x11(void)
       proto_register_field_array(proto_x11, hf, array_length(hf));
       proto_register_subtree_array(ett, array_length(ett));
 
-      byte_ordering_cache = g_tree_new(compareAddresses);
-      address_chunk = g_mem_chunk_new("x11 byte ordering address cache", sizeof(address), 
-				      sizeof(address) * 128, G_ALLOC_ONLY);
-      ipv4_chunk = g_mem_chunk_new("x11 byte ordering ipv4 address cache", 4, 4 * 128, G_ALLOC_ONLY);
-      ipv6_chunk = g_mem_chunk_new("x11 byte ordering ipv6 address cache", 16, 16 * 128, G_ALLOC_ONLY);
-};
+      register_init_routine(x11_init_protocol);
 
+      x11_module = prefs_register_protocol(proto_x11, NULL);
+      prefs_register_bool_preference(x11_module, "desegment",
+	    "Desegment all X11 messages spanning multiple TCP segments",
+	    "Whether the X11 dissector should desegment all messages spanning multiple TCP segments",
+	    &x11_desegment);
+}
 
 void
 proto_reg_handoff_x11(void)
diff --git a/x11-fields b/x11-fields
index 8e55fc72c1..ec40057e67 100644
--- a/x11-fields
+++ b/x11-fields
@@ -3,7 +3,7 @@
 #
 # Copyright 2000, Christophe Tronche <ch.tronche@computer.org>
 #
-# $Id: x11-fields,v 1.4 2001/04/21 08:04:43 guy Exp $
+# $Id: x11-fields,v 1.5 2002/04/16 09:42:31 guy Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@ethereal.com>
@@ -44,6 +44,10 @@ arc		NONE	NONE
 	mode	UINT8	DEC	VALS	Tell us if we're drawing an arc or a pie
 
 atom		UINT32	HEX
+authorization-protocol-name-length	UINT16	DEC
+authorization-protocol-name	STRING	HEX
+authorization-protocol-data-length	UINT16	DEC
+authorization-protocol-data	STRING	HEX
 auto-repeat-mode	UINT8	DEC	VALS
 back-blue	UINT16	DEC		Background blue value for a cursor
 back-green	UINT16	DEC		Background green value for a cursor
@@ -65,6 +69,7 @@ border-pixel	UINT32	HEX
 border-pixmap	UINT32	HEX	VALS
 border-width	UINT16	DEC
 button		UINT8	DEC	VALS
+byte-order	UINT8	HEX	VALS
 cap-style	UINT8	DEC	VALS
 change-host-mode	UINT8	DEC	VALS(insert_delete)
 cid		UINT32	HEX
@@ -328,6 +333,8 @@ properties	NONE	NONE
 
 property	UINT32	HEX
 property-number	UINT16	DEC
+protocol-major-version	UINT16	DEC
+protocol-minor-version	UINT16	DEC
 rectangle-height	UINT16	DEC
 rectangles	NONE	NONE
 rectangle	NONE	NONE