Move the xDLC helper routines into epan.

svn path=/trunk/; revision=12127

11 files changed, 532 insertions, 11 deletions

diff --git a/epan/Makefile.common b/epan/Makefile.common
index 18c558024b..994de14fdf 100644
--- a/epan/Makefile.common
+++ b/epan/Makefile.common
@@ -58,7 +58,8 @@ LIBETHEREAL_SRC = 		\
 	timestamp.c		\
 	to_str.c		\
 	tvbuff.c		\
-	value_string.c
+	value_string.c		\
+	xdlc.c
 
 LIBETHEREAL_INCLUDES = 		\
 	addr_and_mask.h		\
@@ -106,7 +107,8 @@ LIBETHEREAL_INCLUDES = 		\
 	timestamp.h    		\
 	to_str.h		\
 	tvbuff.h		\
-	value_string.h
+	value_string.h		\
+	xdlc.h
 
 # dissector helpers (needed from the dissectors, but not a dissector itself)
 DISSECTOR_SUPPORT_SRC =	\
@@ -121,6 +123,5 @@ DISSECTOR_SUPPORT_SRC =	\
 	../req_resp_hdrs.c	\
 	../t35.c	\
 	../tap.c	\
-	../xdlc.c	\
 	../xmlstub.c
 
diff --git a/epan/dissectors/packet-fr.c b/epan/dissectors/packet-fr.c
index 619c1bb1e1..a8c8f0eec6 100644
--- a/epan/dissectors/packet-fr.c
+++ b/epan/dissectors/packet-fr.c
@@ -48,7 +48,7 @@
 #include <epan/prefs.h>
 #include "packet-llc.h"
 #include "packet-chdlc.h"
-#include "xdlc.h"
+#include <epan/xdlc.h>
 #include "etypes.h"
 #include "oui.h"
 #include "nlpid.h"
diff --git a/epan/dissectors/packet-hpext.c b/epan/dissectors/packet-hpext.c
index 3a14dbb9c3..8a461e028b 100644
--- a/epan/dissectors/packet-hpext.c
+++ b/epan/dissectors/packet-hpext.c
@@ -29,7 +29,7 @@
 
 #include <glib.h>
 #include <epan/packet.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 #include "etypes.h"
 #include "llcsaps.h"
 #include "packet-hpext.h"
diff --git a/epan/dissectors/packet-lapb.c b/epan/dissectors/packet-lapb.c
index 0b010e5073..b208b75525 100644
--- a/epan/dissectors/packet-lapb.c
+++ b/epan/dissectors/packet-lapb.c
@@ -31,7 +31,7 @@
 #include <glib.h>
 #include <string.h>
 #include <epan/packet.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 
 static int proto_lapb = -1;
 static int hf_lapb_address = -1;
diff --git a/epan/dissectors/packet-lapd.c b/epan/dissectors/packet-lapd.c
index d766047ef8..328f5d273f 100644
--- a/epan/dissectors/packet-lapd.c
+++ b/epan/dissectors/packet-lapd.c
@@ -31,7 +31,7 @@
 #include <glib.h>
 #include <string.h>
 #include <epan/packet.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 
 #include "lapd_sapi.h"
 
diff --git a/epan/dissectors/packet-llc.c b/epan/dissectors/packet-llc.c
index 6d488c446d..e7f1b21a2e 100644
--- a/epan/dissectors/packet-llc.c
+++ b/epan/dissectors/packet-llc.c
@@ -30,7 +30,7 @@
 #include <glib.h>
 #include <epan/packet.h>
 #include "oui.h"
-#include "xdlc.h"
+#include <epan/xdlc.h>
 #include "etypes.h"
 #include "llcsaps.h"
 #include "bridged_pids.h"
diff --git a/epan/dissectors/packet-sdlc.c b/epan/dissectors/packet-sdlc.c
index 12a6e2c140..79b6848b71 100644
--- a/epan/dissectors/packet-sdlc.c
+++ b/epan/dissectors/packet-sdlc.c
@@ -30,7 +30,7 @@
 #include <glib.h>
 #include <string.h>
 #include <epan/packet.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 
 /*
  * See
diff --git a/epan/dissectors/packet-v120.c b/epan/dissectors/packet-v120.c
index b47668fc2a..571355c710 100644
--- a/epan/dissectors/packet-v120.c
+++ b/epan/dissectors/packet-v120.c
@@ -31,7 +31,7 @@
 #include <glib.h>
 #include <string.h>
 #include <epan/packet.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 
 static int proto_v120 = -1;
 static int hf_v120_address = -1;
diff --git a/epan/plugins.c b/epan/plugins.c
index aaf852dfeb..1e9f9c9575 100644
--- a/epan/plugins.c
+++ b/epan/plugins.c
@@ -72,7 +72,7 @@
 #include <epan/dissectors/packet-ber.h>
 #include <epan/dissectors/packet-rtp.h>
 #include <epan/dissectors/packet-rtcp.h>
-#include "xdlc.h"
+#include <epan/xdlc.h>
 #include <epan/crc16.h>
 #include "report_err.h"
 #include "plugins/plugin_table.h"
diff --git a/epan/xdlc.c b/epan/xdlc.c
new file mode 100644
index 0000000000..1cef001f9c
--- /dev/null
+++ b/epan/xdlc.c
@@ -0,0 +1,380 @@
+/* xdlc.c
+ * Routines for use by various SDLC-derived protocols, such as HDLC
+ * and its derivatives LAPB, IEEE 802.2 LLC, etc..
+ *
+ * $Id$
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program 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 program 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 program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#include <glib.h>
+#include <epan/packet.h>
+#include <epan/xdlc.h>
+
+const value_string ftype_vals[] = {
+    { XDLC_I, "Information frame" },
+    { XDLC_S, "Supervisory frame" },
+    { XDLC_U, "Unnumbered frame" },
+    { 0,      NULL }
+};
+
+const value_string stype_vals[] = {
+    { XDLC_RR>>2,   "Receiver ready" },
+    { XDLC_RNR>>2,  "Receiver not ready" },
+    { XDLC_REJ>>2,  "Reject" },
+    { XDLC_SREJ>>2, "Selective reject" },
+    { 0,            NULL }
+};
+
+static const value_string modifier_short_vals_cmd[] = {
+    { XDLC_UI,    "UI" },
+    { XDLC_UP,    "UP" },
+    { XDLC_DISC,  "DISC" },
+    { XDLC_UA,    "UA" },
+    { XDLC_SNRM,  "SNRM" },
+    { XDLC_SNRME, "SNRME" },
+    { XDLC_TEST,  "TEST" },
+    { XDLC_SIM,   "SIM" },
+    { XDLC_FRMR,  "FRMR" },
+    { XDLC_CFGR,  "CFGR" },
+    { XDLC_SARM,  "SARM" },
+    { XDLC_SABM,  "SABM" },
+    { XDLC_SARME, "SARME" },
+    { XDLC_SABME, "SABME" },
+    { XDLC_RESET, "RESET" },
+    { XDLC_XID,   "XID" },
+    { XDLC_SNRME, "SNRME" },
+    { XDLC_BCN,   "BCN" },
+    { 0,          NULL }
+};
+
+const value_string modifier_vals_cmd[] = {
+    { XDLC_UI>>2,    "Unnumbered Information" },
+    { XDLC_UP>>2,    "Unnumbered Poll" },
+    { XDLC_DISC>>2,  "Disconnect" },
+    { XDLC_UA>>2,    "Unnumbered Acknowledge" },
+    { XDLC_SNRM>>2,  "Set Normal Response Mode" },
+    { XDLC_TEST>>2,  "Test" },
+    { XDLC_SIM>>2,   "Set Initialization Mode" },
+    { XDLC_FRMR>>2,  "Frame reject" },
+    { XDLC_CFGR>>2,  "Configure" },
+    { XDLC_SARM>>2,  "Set Asynchronous Response Mode" },
+    { XDLC_SABM>>2,  "Set Asynchronous Balanced Mode" },
+    { XDLC_SARME>>2, "Set Asynchronous Response Mode Extended" },
+    { XDLC_SABME>>2, "Set Asynchronous Balanced Mode Extended" },
+    { XDLC_RESET>>2, "Reset" },
+    { XDLC_XID>>2,   "Exchange identification" },
+    { XDLC_SNRME>>2, "Set Normal Response Mode Extended" },
+    { XDLC_BCN>>2,   "Beacon" },
+    { 0,             NULL }
+};
+
+static const value_string modifier_short_vals_resp[] = {
+    { XDLC_UI,    "UI" },
+    { XDLC_UP,    "UP" },
+    { XDLC_RD,    "RD" },
+    { XDLC_UA,    "UA" },
+    { XDLC_SNRM,  "SNRM" },
+    { XDLC_TEST,  "TEST" },
+    { XDLC_RIM,   "RIM" },
+    { XDLC_FRMR,  "FRMR" },
+    { XDLC_CFGR,  "CFGR" },
+    { XDLC_DM,    "DM" },
+    { XDLC_SABM,  "SABM" },
+    { XDLC_SARME, "SARME" },
+    { XDLC_SABME, "SABME" },
+    { XDLC_RESET, "RESET" },
+    { XDLC_XID,   "XID" },
+    { XDLC_SNRME, "SNRME" },
+    { XDLC_BCN,   "BCN" },
+    { 0,          NULL }
+};
+
+const value_string modifier_vals_resp[] = {
+    { XDLC_UI>>2,    "Unnumbered Information" },
+    { XDLC_UP>>2,    "Unnumbered Poll" },
+    { XDLC_RD>>2,    "Request Disconnect" },
+    { XDLC_UA>>2,    "Unnumbered Acknowledge" },
+    { XDLC_SNRM>>2,  "Set Normal Response Mode" },
+    { XDLC_TEST>>2,  "Test" },
+    { XDLC_RIM>>2,   "Request Initialization Mode" },
+    { XDLC_FRMR>>2,  "Frame reject" },
+    { XDLC_CFGR>>2,  "Configure" },
+    { XDLC_DM>>2,    "Disconnected mode" },
+    { XDLC_SABM>>2,  "Set Asynchronous Balanced Mode" },
+    { XDLC_SARME>>2, "Set Asynchronous Response Mode Extended" },
+    { XDLC_SABME>>2, "Set Asynchronous Balanced Mode Extended" },
+    { XDLC_RESET>>2, "Reset" },
+    { XDLC_XID>>2,   "Exchange identification" },
+    { XDLC_SNRME>>2, "Set Normal Response Mode Extended" },
+    { XDLC_BCN>>2,   "Beacon" },
+    { 0,             NULL }
+};
+
+int
+get_xdlc_control(const guchar *pd, int offset, int is_extended)
+{
+    guint16 control;
+
+    switch (pd[offset] & 0x03) {
+
+    case XDLC_S:
+    default:
+        /*
+	 * Supervisory or Information frame.
+	 */
+	if (is_extended)
+		control = pletohs(&pd[offset]);
+	else
+		control = pd[offset];
+	break;
+
+    case XDLC_U:
+	/*
+	 * Unnumbered frame.
+	 *
+	 * XXX - is this two octets, with a P/F bit, in HDLC extended
+	 * operation?  It's one octet in LLC, even though the control
+	 * field of I and S frames is a 2-byte extended-operation field
+	 * in LLC.  Given that there are no sequence numbers in the
+	 * control field of a U frame, there doesn't appear to be any
+	 * need for it to be 2 bytes in extended operation.
+	 */
+	control = pd[offset];
+	break;
+    }
+    return control;
+}
+
+int
+dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
+  proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
+  const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
+  const value_string *u_modifier_short_vals_cmd,
+  const value_string *u_modifier_short_vals_resp, int is_response,
+  int is_extended, int append_info)
+{
+    guint16 control;
+    int control_len;
+    const xdlc_cf_items *cf_items;
+    char *control_format;
+    guint16 poll_final;
+    char info[80];
+    proto_tree *tc, *control_tree;
+    gchar *frame_type = NULL;
+    gchar *modifier;
+
+    switch (tvb_get_guint8(tvb, offset) & 0x03) {
+
+    case XDLC_S:
+	if (is_extended) {
+	    control = tvb_get_letohs(tvb, offset);
+	    control_len = 2;
+	    cf_items = cf_items_ext;
+	    control_format = "Control field: %s (0x%04X)";
+	} else {
+	    control = tvb_get_guint8(tvb, offset);
+	    control_len = 1;
+	    cf_items = cf_items_nonext;
+	    control_format = "Control field: %s (0x%02X)";
+	}
+        /*
+	 * Supervisory frame.
+	 */
+	switch (control & XDLC_S_FTYPE_MASK) {
+	case XDLC_RR:
+	    frame_type = "RR";
+	    break;
+
+	case XDLC_RNR:
+	    frame_type = "RNR";
+	    break;
+
+	case XDLC_REJ:
+	    frame_type = "REJ";
+	    break;
+
+	case XDLC_SREJ:
+	    frame_type = "SREJ";
+	    break;
+	}
+	if (is_extended) {
+	    poll_final = (control & XDLC_P_F_EXT);
+	    sprintf(info, "S%s, func=%s, N(R)=%u",
+		 	(poll_final ?
+		 	    (is_response ? " F" : " P") :
+		 	    ""),
+			frame_type,
+			(control & XDLC_N_R_EXT_MASK) >> XDLC_N_R_EXT_SHIFT);
+	} else {
+	    poll_final = (control & XDLC_P_F);
+	    sprintf(info, "S%s, func=%s, N(R)=%u",
+		 	(poll_final ?
+		 	    (is_response ? " F" : " P") :
+		 	    ""),
+		 	frame_type,
+			(control & XDLC_N_R_MASK) >> XDLC_N_R_SHIFT);
+	}
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+	    if (append_info) {
+	    	col_append_str(pinfo->cinfo, COL_INFO, ", ");
+		col_append_str(pinfo->cinfo, COL_INFO, info);
+	    } else
+		col_add_str(pinfo->cinfo, COL_INFO, info);
+	}
+	if (xdlc_tree) {
+	    tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control, tvb,
+		offset, control_len, control, control_format, info, control);
+	    control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_r,
+		tvb, offset, control_len, control);
+	    if (poll_final) {
+		proto_tree_add_boolean(control_tree,
+			(is_response ? *cf_items->hf_xdlc_f :
+				       *cf_items->hf_xdlc_p),
+			tvb, offset, control_len, control);
+	    }
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_s_ftype,
+		tvb, offset, control_len, control);
+	    /* This will always say it's a supervisory frame */
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_s_u,
+		tvb, offset, control_len, control);
+	}
+	break;
+
+    case XDLC_U:
+	/*
+	 * Unnumbered frame.
+	 *
+	 * XXX - is this two octets, with a P/F bit, in HDLC extended
+	 * operation?  It's one octet in LLC, even though the control
+	 * field of I and S frames is a 2-byte extended-operation field
+	 * in LLC.  Given that there are no sequence numbers in the
+	 * control field of a U frame, there doesn't appear to be any
+	 * need for it to be 2 bytes in extended operation.
+	 */
+	if (u_modifier_short_vals_cmd == NULL)
+		u_modifier_short_vals_cmd = modifier_short_vals_cmd;
+	if (u_modifier_short_vals_resp == NULL)
+		u_modifier_short_vals_resp = modifier_short_vals_resp;
+	control = tvb_get_guint8(tvb, offset);
+	control_len = 1;
+	cf_items = cf_items_nonext;
+	control_format = "Control field: %s (0x%02X)";
+	if (is_response) {
+		modifier = match_strval(control & XDLC_U_MODIFIER_MASK,
+			u_modifier_short_vals_resp);
+	} else {
+		modifier = match_strval(control & XDLC_U_MODIFIER_MASK,
+			u_modifier_short_vals_cmd);
+	}
+	if (modifier == NULL)
+		modifier = "Unknown";
+	poll_final = (control & XDLC_P_F);
+	sprintf(info, "U%s, func=%s",
+		(poll_final ?
+		    (is_response ? " F" : " P") :
+		    ""),
+		modifier);
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+	    if (append_info) {
+	    	col_append_str(pinfo->cinfo, COL_INFO, ", ");
+		col_append_str(pinfo->cinfo, COL_INFO, info);
+	    } else
+		col_add_str(pinfo->cinfo, COL_INFO, info);
+	}
+	if (xdlc_tree) {
+	    tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control,	tvb,
+		offset, control_len, control, control_format, info, control);
+	    control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
+	    if (poll_final) {
+		proto_tree_add_boolean(control_tree,
+			(is_response ? *cf_items->hf_xdlc_f:
+				       *cf_items->hf_xdlc_p),
+			tvb, offset, control_len, control);
+	    }
+	    proto_tree_add_uint(control_tree,
+		(is_response ? *cf_items->hf_xdlc_u_modifier_resp :
+			       *cf_items->hf_xdlc_u_modifier_cmd),
+	    	tvb, offset, control_len, control);
+	    /* This will always say it's an unnumbered frame */
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_s_u,
+		tvb, offset, control_len, control);
+	}
+	break;
+
+    default:
+	/*
+	 * Information frame.
+	 */
+	if (is_extended) {
+	    control = tvb_get_letohs(tvb, offset);
+	    control_len = 2;
+	    cf_items = cf_items_ext;
+	    control_format = "Control field: %s (0x%04X)";
+	    poll_final = (control & XDLC_P_F_EXT);
+	    sprintf(info, "I%s, N(R)=%u, N(S)=%u",
+			((control & XDLC_P_F_EXT) ? " P" : ""),
+			(control & XDLC_N_R_EXT_MASK) >> XDLC_N_R_EXT_SHIFT,
+			(control & XDLC_N_S_EXT_MASK) >> XDLC_N_S_EXT_SHIFT);
+	} else {
+	    control = tvb_get_guint8(tvb, offset);
+	    control_len = 1;
+	    cf_items = cf_items_nonext;
+	    control_format = "Control field: %s (0x%02X)";
+	    poll_final = (control & XDLC_P_F);
+	    sprintf(info, "I%s, N(R)=%u, N(S)=%u",
+			((control & XDLC_P_F) ? " P" : ""),
+			(control & XDLC_N_R_MASK) >> XDLC_N_R_SHIFT,
+			(control & XDLC_N_S_MASK) >> XDLC_N_S_SHIFT);
+	}
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+	    if (append_info) {
+	    	col_append_str(pinfo->cinfo, COL_INFO, ", ");
+		col_append_str(pinfo->cinfo, COL_INFO, info);
+	    } else
+		col_add_str(pinfo->cinfo, COL_INFO, info);
+	}
+	if (xdlc_tree) {
+	    tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control, tvb,
+		offset, control_len, control, control_format, info, control);
+	    control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_r,
+		tvb, offset, control_len, control);
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_s,
+		tvb, offset, control_len, control);
+	    if (poll_final) {
+		proto_tree_add_boolean(control_tree, *cf_items->hf_xdlc_p,
+		    	tvb, offset, control_len, control);
+	    }
+	    /* This will always say it's an information frame */
+	    proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_i,
+		tvb, offset, control_len, control);
+	}
+	break;
+    }
+    return control;
+}
diff --git a/epan/xdlc.h b/epan/xdlc.h
new file mode 100644
index 0000000000..fc924ef6ee
--- /dev/null
+++ b/epan/xdlc.h
@@ -0,0 +1,140 @@
+/* xdlc.h
+ * Define *DLC frame types, and routine to dissect the control field of
+ * a *DLC frame.
+ *
+ * $Id$
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program 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 program 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 program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __XDLC_H__
+#define __XDLC_H__
+
+/*
+ * Low-order bits of first (extended) or only (basic) octet of control
+ * field, specifying the frame type.
+ */
+#define XDLC_I_MASK		0x01	/* Mask to test for I or not I */
+#define XDLC_I			0x00	/* Information frames */
+#define XDLC_S_U_MASK		0x03	/* Mask to test for S or U */
+#define XDLC_S			0x01	/* Supervisory frames */
+#define XDLC_U			0x03	/* Unnumbered frames */
+
+/*
+ * N(S) and N(R) fields, in basic and extended operation.
+ */
+#define XDLC_N_R_MASK		0xE0	/* basic */
+#define XDLC_N_R_SHIFT		5
+#define XDLC_N_R_EXT_MASK	0xFE00	/* extended */
+#define XDLC_N_R_EXT_SHIFT	9
+#define XDLC_N_S_MASK		0x0E	/* basic */
+#define XDLC_N_S_SHIFT		1
+#define XDLC_N_S_EXT_MASK	0x00FE	/* extended */
+#define XDLC_N_S_EXT_SHIFT	1
+
+/*
+ * Poll/Final bit, in basic and extended operation.
+ */
+#define XDLC_P_F	0x10	/* basic */
+#define XDLC_P_F_EXT	0x0100	/* extended */
+
+/*
+ * S-format frame types.
+ */
+#define XDLC_S_FTYPE_MASK	0x0C
+#define XDLC_RR			0x00	/* Receiver ready */
+#define XDLC_RNR		0x04	/* Receiver not ready */
+#define XDLC_REJ		0x08	/* Reject */
+#define XDLC_SREJ		0x0C	/* Selective reject */
+
+/*
+ * U-format modifiers.
+ */
+#define XDLC_U_MODIFIER_MASK	0xEC
+#define XDLC_UI		0x00	/* Unnumbered Information */
+#define XDLC_UP		0x20	/* Unnumbered Poll */
+#define XDLC_DISC	0x40	/* Disconnect (command) */
+#define XDLC_RD		0x40	/* Request Disconnect (response) */
+#define XDLC_UA		0x60	/* Unnumbered Acknowledge */
+#define XDLC_SNRM	0x80	/* Set Normal Response Mode */
+#define XDLC_TEST	0xE0	/* Test */
+#define XDLC_SIM	0x04	/* Set Initialization Mode (command) */
+#define XDLC_RIM	0x04	/* Request Initialization Mode (response) */
+#define XDLC_FRMR	0x84	/* Frame reject */
+#define XDLC_CFGR	0xC4	/* Configure */
+#define XDLC_SARM	0x0C	/* Set Asynchronous Response Mode (command) */
+#define XDLC_DM		0x0C	/* Disconnected mode (response) */
+#define XDLC_SABM	0x2C	/* Set Asynchronous Balanced Mode */
+#define XDLC_SARME	0x4C	/* Set Asynchronous Response Mode Extended */
+#define XDLC_SABME	0x6C	/* Set Asynchronous Balanced Mode Extended */
+#define XDLC_RESET	0x8C	/* Reset */
+#define XDLC_XID	0xAC	/* Exchange identification */
+#define XDLC_SNRME	0xCC	/* Set Normal Response Mode Extended */
+#define XDLC_BCN	0xEC	/* Beacon */
+
+/*
+ * This macro takes the control field of an xDLC frame, as returned by
+ * "get_xdlc_control()" or "dissect_xdlc_control()", and evaluates to
+ * TRUE if the frame is an "information" frame and FALSE if it isn't.
+ * Note that frames other than information frames can have data in them,
+ * e.g. TEST frames.
+ */
+#define XDLC_IS_INFORMATION(control) \
+	(((control) & XDLC_I_MASK) == XDLC_I || (control) == (XDLC_UI|XDLC_U))
+
+/*
+ * This macro takes the control field of an xDLC frame, and a flag saying
+ * whether we're doing basic or extended operation, and evaluates to
+ * the length of that field (if it's an Unnumbered frame, or we're not
+ * in extended mode, it's 1 byte long, otherwise it's 2 bytes long).
+ */
+#define XDLC_CONTROL_LEN(control, is_extended) \
+	((((control) & XDLC_S_U_MASK) == XDLC_U || !(is_extended)) ? 1 : 2)
+
+/*
+ * Structure containing pointers to hf_ values for various subfields of
+ * the control field.
+ */
+typedef struct {
+	int	*hf_xdlc_n_r;
+	int	*hf_xdlc_n_s;
+	int	*hf_xdlc_p;
+	int	*hf_xdlc_f;
+	int	*hf_xdlc_s_ftype;
+	int	*hf_xdlc_u_modifier_cmd;
+	int	*hf_xdlc_u_modifier_resp;
+	int	*hf_xdlc_ftype_i;
+	int	*hf_xdlc_ftype_s_u;
+} xdlc_cf_items;
+
+extern const value_string ftype_vals[];
+extern const value_string stype_vals[];
+extern const value_string modifier_vals_cmd[];
+extern const value_string modifier_vals_resp[];
+
+extern int get_xdlc_control(const guchar *pd, int offset, int extended);
+
+extern int dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
+  proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
+  const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
+  const value_string *u_modifier_short_vals_cmd,
+  const value_string *u_modifier_short_vals_resp, int is_response,
+  int is_extended, int append_info);
+
+#endif