Move dissectors to epan/dissectors directory.

Also move ncp222.py, x11-fields, process-x11-fields.pl,
make-reg-dotc, and make-reg-dotc.py.

Adjust #include lines in files that include packet-*.h
files.

svn path=/trunk/; revision=11410

1 files changed, 928 insertions, 0 deletions

diff --git a/epan/dissectors/packet-isis-hello.c b/epan/dissectors/packet-isis-hello.c
new file mode 100644
index 0000000000..f7518d5bfa
--- /dev/null
+++ b/epan/dissectors/packet-isis-hello.c
@@ -0,0 +1,928 @@
+/* packet-isis-hello.c
+ * Routines for decoding isis hello packets and their CLVs
+ *
+ * $Id$
+ * Stuart Stanley <stuarts@mxmail.net>
+ *
+ * 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 "packet-osi.h"
+#include "packet-isis.h"
+#include "packet-isis-clv.h"
+#include "packet-isis-hello.h"
+#include "epan/resolv.h"
+
+/* hello packets */
+static int hf_isis_hello_circuit_reserved = -1;
+static int hf_isis_hello_source_id = -1;
+static int hf_isis_hello_holding_timer = -1;
+static int hf_isis_hello_pdu_length = -1;
+static int hf_isis_hello_priority_reserved = -1;
+static int hf_isis_hello_lan_id = -1;
+static int hf_isis_hello_local_circuit_id = -1;
+static int hf_isis_hello_clv_ipv4_int_addr = -1;
+static int hf_isis_hello_clv_ipv6_int_addr = -1;
+static int hf_isis_hello_clv_ptp_adj = -1;
+static int hf_isis_hello_clv_mt = -1;
+
+static gint ett_isis_hello = -1;
+static gint ett_isis_hello_clv_area_addr = -1;
+static gint ett_isis_hello_clv_is_neighbors = -1;
+static gint ett_isis_hello_clv_padding = -1;
+static gint ett_isis_hello_clv_unknown = -1;
+static gint ett_isis_hello_clv_nlpid = -1;
+static gint ett_isis_hello_clv_authentication = -1;
+static gint ett_isis_hello_clv_ip_authentication = -1;
+static gint ett_isis_hello_clv_ipv4_int_addr = -1;
+static gint ett_isis_hello_clv_ipv6_int_addr = -1;
+static gint ett_isis_hello_clv_ptp_adj = -1;
+static gint ett_isis_hello_clv_mt = -1;
+static gint ett_isis_hello_clv_restart = -1;
+static gint ett_isis_hello_clv_checksum = -1;
+
+static const value_string isis_hello_circuit_type_vals[] = {
+	{ ISIS_HELLO_TYPE_RESERVED,	"Reserved 0 (discard PDU)"},
+	{ ISIS_HELLO_TYPE_LEVEL_1,	"Level 1 only"},
+	{ ISIS_HELLO_TYPE_LEVEL_2,	"Level 2 only"},
+	{ ISIS_HELLO_TYPE_LEVEL_12,	"Level 1 and 2"},
+	{ 0,		NULL} };
+
+/*
+ * Predclare dissectors for use in clv dissection.
+ */
+static void dissect_hello_padding_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_is_neighbors_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_ptp_adj_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_area_address_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_authentication_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_ip_authentication_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_checksum_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_ipv6_int_addr_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_ip_int_addr_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_mt_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_nlpid_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+static void dissect_hello_restart_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length, int length);
+
+
+static const isis_clv_handle_t clv_l1_hello_opts[] = {
+	{
+		ISIS_CLV_AREA_ADDRESS,
+		"Area address(es)",
+		&ett_isis_hello_clv_area_addr,
+		dissect_hello_area_address_clv
+	},
+	{
+		ISIS_CLV_IS_NEIGHBORS,
+		"IS Neighbor(s)",
+		&ett_isis_hello_clv_is_neighbors,
+		dissect_hello_is_neighbors_clv
+	},
+	{
+		ISIS_CLV_PADDING,
+		"Padding",
+		&ett_isis_hello_clv_padding,
+		dissect_hello_padding_clv
+	},
+	{
+		ISIS_CLV_PROTOCOLS_SUPPORTED,
+		"Protocols Supported",
+		&ett_isis_hello_clv_nlpid,
+		dissect_hello_nlpid_clv
+	},
+	{
+		ISIS_CLV_IP_ADDR,
+		"IP Interface address(es)",
+		&ett_isis_hello_clv_ipv4_int_addr,
+		dissect_hello_ip_int_addr_clv
+	},
+	{
+		ISIS_CLV_IP6_ADDR,
+		"IPv6 Interface address(es)",
+		&ett_isis_hello_clv_ipv6_int_addr,
+		dissect_hello_ipv6_int_addr_clv
+	},
+	{
+		ISIS_CLV_RESTART,
+		"Restart Signaling",
+		&ett_isis_hello_clv_restart,
+		dissect_hello_restart_clv
+	},
+	{
+		ISIS_CLV_AUTHENTICATION,
+		"Authentication",
+		&ett_isis_hello_clv_authentication,
+		dissect_hello_authentication_clv
+	},
+	{
+		ISIS_CLV_IP_AUTHENTICATION,
+		"IP Authentication",
+		&ett_isis_hello_clv_ip_authentication,
+		dissect_hello_ip_authentication_clv
+	},
+	{
+		ISIS_CLV_MT_SUPPORTED,
+		"Multi Topology",
+		&ett_isis_hello_clv_mt,
+		dissect_hello_mt_clv
+	},
+	{
+		ISIS_CLV_CHECKSUM,
+		"Checksum",
+		&ett_isis_hello_clv_checksum,
+		dissect_hello_checksum_clv
+	},
+	{
+		0,
+		"",
+		NULL,
+		NULL
+	}
+};
+
+static const isis_clv_handle_t clv_l2_hello_opts[] = {
+	{
+		ISIS_CLV_AREA_ADDRESS,
+		"Area address(es)",
+		&ett_isis_hello_clv_area_addr,
+		dissect_hello_area_address_clv
+	},
+	{
+		ISIS_CLV_IS_NEIGHBORS,
+		"IS Neighbor(s)",
+		&ett_isis_hello_clv_is_neighbors,
+		dissect_hello_is_neighbors_clv
+	},
+	{
+		ISIS_CLV_PADDING,
+		"Padding",
+		&ett_isis_hello_clv_padding,
+		dissect_hello_padding_clv
+	},
+	{
+		ISIS_CLV_PROTOCOLS_SUPPORTED,
+		"Protocols Supported",
+		&ett_isis_hello_clv_nlpid,
+		dissect_hello_nlpid_clv
+	},
+	{
+		ISIS_CLV_IP_ADDR,
+		"IP Interface address(es)",
+		&ett_isis_hello_clv_ipv4_int_addr,
+		dissect_hello_ip_int_addr_clv
+	},
+	{
+		ISIS_CLV_IP6_ADDR,
+		"IPv6 Interface address(es)",
+		&ett_isis_hello_clv_ipv6_int_addr,
+		dissect_hello_ipv6_int_addr_clv
+	},
+	{
+		ISIS_CLV_AUTHENTICATION,
+		"Authentication",
+		&ett_isis_hello_clv_authentication,
+		dissect_hello_authentication_clv
+	},
+	{
+		ISIS_CLV_IP_AUTHENTICATION,
+		"IP Authentication",
+		&ett_isis_hello_clv_ip_authentication,
+		dissect_hello_ip_authentication_clv
+	},
+	{
+		ISIS_CLV_RESTART,
+		"Restart Signaling",
+		&ett_isis_hello_clv_restart,
+		dissect_hello_restart_clv
+	},
+	{
+		ISIS_CLV_MT_SUPPORTED,
+		"Multi Topology",
+		&ett_isis_hello_clv_mt,
+		dissect_hello_mt_clv
+	},
+	{
+		ISIS_CLV_CHECKSUM,
+		"Checksum",
+		&ett_isis_hello_clv_checksum,
+		dissect_hello_checksum_clv
+	},
+	{
+		0,
+		"",
+		NULL,
+		NULL
+	}
+};
+
+static const isis_clv_handle_t clv_ptp_hello_opts[] = {
+	{
+		ISIS_CLV_AREA_ADDRESS,
+		"Area address(es)",
+		&ett_isis_hello_clv_area_addr,
+		dissect_hello_area_address_clv
+	},
+	{
+		ISIS_CLV_PADDING,
+		"Padding",
+		&ett_isis_hello_clv_padding,
+		dissect_hello_padding_clv
+	},
+	{
+		ISIS_CLV_PROTOCOLS_SUPPORTED,
+		"Protocols Supported",
+		&ett_isis_hello_clv_nlpid,
+		dissect_hello_nlpid_clv
+	},
+	{
+		ISIS_CLV_IP_ADDR,
+		"IP Interface address(es)",
+		&ett_isis_hello_clv_ipv4_int_addr,
+		dissect_hello_ip_int_addr_clv
+	},
+	{
+		ISIS_CLV_IP6_ADDR,
+		"IPv6 Interface address(es)",
+		&ett_isis_hello_clv_ipv6_int_addr,
+		dissect_hello_ipv6_int_addr_clv
+	},
+	{
+		ISIS_CLV_AUTHENTICATION,
+		"Authentication",
+		&ett_isis_hello_clv_authentication,
+		dissect_hello_authentication_clv
+	},
+	{
+		ISIS_CLV_IP_AUTHENTICATION,
+		"IP Authentication",
+		&ett_isis_hello_clv_ip_authentication,
+		dissect_hello_ip_authentication_clv
+	},
+	{
+		ISIS_CLV_RESTART,
+		"Restart Option",
+		&ett_isis_hello_clv_restart,
+		dissect_hello_restart_clv
+	},
+	{
+		ISIS_CLV_PTP_ADJ_STATE,
+		"Point-to-point Adjacency State",
+		&ett_isis_hello_clv_ptp_adj,
+		dissect_hello_ptp_adj_clv
+	},
+	{
+		ISIS_CLV_MT_SUPPORTED,
+		"Multi Topology",
+		&ett_isis_hello_clv_mt,
+		dissect_hello_mt_clv
+	},
+	{
+		ISIS_CLV_CHECKSUM,
+		"Checksum",
+		&ett_isis_hello_clv_checksum,
+		dissect_hello_checksum_clv
+	},
+	{
+		0,
+		"",
+		NULL,
+		NULL
+	}
+};
+
+
+/*
+ * Name: dissect_hello_restart_clv()
+ *
+ * Description:
+ *	Decode for a restart clv - only found in IIHs
+ *      hence no call in the common clv dissector
+ *
+ */
+
+static void
+dissect_hello_restart_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	int restart_options;
+
+	if (length != 3) {
+	    isis_dissect_unknown(tvb, tree, offset,
+				 "malformed TLV (%d vs 3)",
+				 length, 3 );
+	    return;
+	}
+
+	restart_options = tvb_get_guint8(tvb, offset);
+
+	proto_tree_add_text ( tree, tvb, offset, 1,
+			      "Restart Request bit %s, "
+			      "Restart Acknowledgement bit %s",
+			      ISIS_MASK_RESTART_RR(restart_options) ? "set" : "clear",
+			      ISIS_MASK_RESTART_RA(restart_options) ? "set" : "clear");
+	proto_tree_add_text ( tree, tvb, offset+1, 2,
+			      "Remaining holding time: %us",
+			      tvb_get_ntohs(tvb, offset+1) );
+}
+
+/*
+ * Name: dissect_hello_nlpid_clv()
+ *
+ * Description:
+ *	Decode for a hello packets NLPID clv.  Calls into the
+ *	clv common one.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_nlpid_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_nlpid_clv(tvb, tree, offset, length);
+}
+
+/*
+ * Name: dissect_hello_mt_clv()
+ *
+ * Description:
+ *	Decode for a hello packets Multi Topology clv.  Calls into the
+ *	clv common one.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+
+static void
+dissect_hello_mt_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_mt_clv(tvb, tree, offset, length,
+		hf_isis_hello_clv_mt );
+}
+
+/*
+ * Name: dissect_hello_ip_int_addr_clv()
+ *
+ * Description:
+ *	Decode for a hello packets ip interface addr clv.  Calls into the
+ *	clv common one.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_ip_int_addr_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_ip_int_clv(tvb, tree, offset, length,
+		hf_isis_hello_clv_ipv4_int_addr );
+}
+
+/*
+ * Name: dissect_hello_ipv6_int_addr_clv()
+ *
+ * Description:
+ *	Decode for a hello packets ipv6 interface addr clv.  Calls into the
+ *	clv common one.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_ipv6_int_addr_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_ipv6_int_clv(tvb, tree, offset, length,
+		hf_isis_hello_clv_ipv6_int_addr );
+}
+
+/*
+ * Name: dissect_hello_authentication_clv()
+ *
+ * Description:
+ *	Decode for a hello packets authenticaion clv.
+ *      Calls into the CLV common one. 
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_authentication_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_authentication_clv(tvb, tree, offset, length);
+}
+
+/*
+ * Name: dissect_hello_ip_authentication_clv()
+ *
+ * Description:
+ *	Decode for a hello packets IP authenticaion clv.
+ *      Calls into the CLV common one. 
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_ip_authentication_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_ip_authentication_clv(tvb, tree, offset, length);
+}
+
+/*
+ * Name: dissect_hello_checksum_clv()
+ *
+ * Description:
+ *      dump and verify the optional checksum in TLV 12
+ *
+ * Input:
+ *      tvbuff_t * : tvbuffer for packet data
+ *      proto_tree * : protocol display tree to fill out.  May be NULL
+ *      int : offset into packet data where we are.
+ *      int : length of clv we are decoding
+ *
+ * Output:
+ *      void, but we will add to proto tree if !NULL.
+ */
+
+static void
+dissect_hello_checksum_clv(tvbuff_t *tvb,
+        proto_tree *tree, int offset, int id_length _U_, int length) {
+
+	guint16 pdu_length,checksum, cacl_checksum=0;
+
+	if (tree) {
+                if ( length != 2 ) {
+                        proto_tree_add_text ( tree, tvb, offset, length,
+                                              "incorrect checksum length (%u), should be (2)", length );
+                        return;
+                }
+
+    		checksum = tvb_get_ntohs(tvb, offset);    		
+
+                /* the check_and_get_checksum() function needs to know how big
+                 * the packet is. we can either pass through the pdu-len through several layers
+                 * of dissectors and wrappers or extract the PDU length field from the PDU specific header
+                 * which is offseted 17 bytes in IIHs (relative to the beginning of the IS-IS packet) */
+
+    		pdu_length = tvb_get_ntohs(tvb, 17);   
+
+                /* unlike the LSP checksum verification which starts at an offset of 12 we start at offset 0*/
+		switch (check_and_get_checksum(tvb, 0, pdu_length, checksum, offset, &cacl_checksum))
+		{
+
+        		case NO_CKSUM :
+                                proto_tree_add_text ( tree, tvb, offset, length,
+                                                      "Checksum: 0x%04x (unused)", checksum);
+       	 		break;
+        		case DATA_MISSING :
+          			isis_dissect_unknown(tvb, tree, offset,
+                                                     "packet length %d went beyond packet",
+                                                     tvb_length_remaining(tvb, 0));
+        		break;
+        		case CKSUM_NOT_OK :
+                                proto_tree_add_text ( tree, tvb, offset, length,
+                                                      "Checksum: 0x%04x (incorrect, should be 0x%04x)",
+                                                      checksum,
+                                                      cacl_checksum);
+        		break;
+	        	case CKSUM_OK :
+                                proto_tree_add_text ( tree, tvb, offset, length,
+                                                      "Checksum: 0x%04x (correct)", checksum);
+        		break;
+        		default :
+          			g_message("'check_and_get_checksum' returned an invalid value");
+    		}
+	}
+}
+
+
+
+/*
+ * Name: dissect_hello_area_address_clv()
+ *
+ * Description:
+ *	Decode for a hello packets area address clv.
+ *      Calls into the CLV common one.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void, will modify proto_tree if not null.
+ */
+static void
+dissect_hello_area_address_clv(tvbuff_t *tvb,
+	proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	isis_dissect_area_address_clv(tvb, tree, offset, length);
+}
+
+
+
+static void
+dissect_hello_ptp_adj_clv(tvbuff_t *tvb,
+		proto_tree *tree, int offset, int id_length _U_, int length)
+{
+	static const value_string adj_state_vals[] = {
+	    { 0, "Up" },
+	    { 1, "Initializing" },
+	    { 2, "Down" },
+	    { 0, NULL }
+	};
+	guint8 adj_state;
+	char *adj_state_str;
+
+	adj_state = tvb_get_guint8(tvb, offset);
+	adj_state_str = val_to_str(adj_state, adj_state_vals, "Unknown (%u)");
+	switch(length) {
+	  case 1:
+	    proto_tree_add_text ( tree, tvb, offset, 1,
+				  "Adjacency State: %s", adj_state_str );
+	    break;
+	  case 5:
+	    proto_tree_add_text ( tree, tvb, offset, 1,
+                                  "Adjacency State: %s", adj_state_str );
+	    proto_tree_add_text ( tree, tvb, offset+1, 4,
+                                  "Extended Local circuit ID: 0x%08x", tvb_get_ntohl(tvb, offset+1) );
+	    break;
+	  case 11:
+            proto_tree_add_text ( tree, tvb, offset, 1,
+                                  "Adjacency State: %s", adj_state_str );
+            proto_tree_add_text ( tree, tvb, offset+1, 4,
+                                  "Extended Local circuit ID: 0x%08x", tvb_get_ntohl(tvb, offset+1) );
+            proto_tree_add_text ( tree, tvb, offset+5, 6,
+                                  "Neighbor SystemID: %s", print_system_id( tvb_get_ptr(tvb, offset+5, 6), 6 ) );
+	    break;
+	  case 15:
+	    proto_tree_add_text ( tree, tvb, offset, 1,
+                                  "Adjacency State: %s", adj_state_str );
+            proto_tree_add_text ( tree, tvb, offset+1, 4,
+                                  "Extended Local circuit ID: 0x%08x", tvb_get_ntohl(tvb, offset+1) );
+            proto_tree_add_text ( tree, tvb, offset+5, 6,
+                                  "Neighbor SystemID: %s", print_system_id( tvb_get_ptr(tvb, offset+5, 6), 6 ) );
+            proto_tree_add_text ( tree, tvb, offset+11, 4,
+                                  "Neighbor Extended Local circuit ID: 0x%08x", tvb_get_ntohl(tvb, offset+11) );
+	    break;
+	  default:
+	    isis_dissect_unknown(tvb, tree, offset,
+				 "malformed TLV (%d vs 1,5,11,15)", length );
+	    return;
+	}
+}
+
+/*
+ * Name: isis_dissect_is_neighbors_clv()
+ *
+ * Description:
+ *	Take apart a IS neighbor packet.  A neighbor is n 6 byte packets.
+ *	(they tend to be an 802.3 MAC address, but its not required).
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : protocol display tree to fill out.  May be NULL
+ *	int : offset into packet data where we are.
+ *	int : length of IDs in packet.
+ *	int : length of clv we are decoding
+ *
+ * Output:
+ *	void, but we will add to proto tree if !NULL.
+ */
+static void
+dissect_hello_is_neighbors_clv(tvbuff_t *tvb, proto_tree *tree, int offset,
+	int id_length _U_, int length)
+{
+	while ( length > 0 ) {
+		if (length<6) {
+			isis_dissect_unknown(tvb, tree, offset,
+				"short is neighbor (%d vs 6)", length );
+			return;
+		}
+		/*
+		 * Lets turn the area address into "standard" 0000.0000.etc
+		 * format string.
+		 */
+		if ( tree ) {
+			proto_tree_add_text ( tree, tvb, offset, 6,
+				"IS Neighbor: %s", get_ether_name( tvb_get_ptr(tvb, offset, 6)) );
+		}
+		offset += 6;
+		length -= 6;
+	}
+}
+
+/*
+ * Name: dissect_hello_padding_clv()
+ *
+ * Description:
+ *	Decode for a hello packet's padding clv.  Padding does nothing,
+ *	so we just return.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : proto tree to build on (may be null)
+ *	int : current offset into packet data
+ *	int : length of IDs in packet.
+ *	int : length of this clv
+ *
+ * Output:
+ *	void
+ */
+static void
+dissect_hello_padding_clv(tvbuff_t *tvb _U_, proto_tree *tree _U_, int offset _U_,
+	int id_length _U_, int length _U_)
+{
+	/* nothing to do here! */
+}
+
+
+/*
+ * Name: isis_dissect_isis_hello()
+ *
+ * Description:
+ *	This procedure rips apart the various types of ISIS hellos.  L1H and
+ *	L2H's are identical for the most part, while the PTP hello has
+ *	a shorter header.
+ *
+ * Input:
+ *	tvbuff_t * : tvbuffer for packet data
+ *	proto_tree * : protocol display tree to add to.  May be NULL.
+ *	int offset : our offset into packet data.
+ *	int : hello type, a la packet-isis.h ISIS_TYPE_* values
+ *	int : header length of packet.
+ *	int : length of IDs in packet.
+ *
+ * Output:
+ *	void, will modify proto_tree if not NULL.
+ */
+void
+isis_dissect_isis_hello(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset,
+	int hello_type, int header_length, int id_length)
+{
+	proto_item	*ti;
+	proto_tree	*hello_tree = NULL;
+	int 		len;
+	guint8		octet;
+	const guint8	*source_id;
+	guint16		pdu_length;
+	const guint8	*lan_id;
+
+	if (tree) {
+		ti = proto_tree_add_text(tree, tvb, offset, -1, "ISIS HELLO");
+		hello_tree = proto_item_add_subtree(ti, ett_isis_hello);
+		octet = tvb_get_guint8(tvb, offset);
+		proto_tree_add_uint_format(hello_tree,
+			hf_isis_hello_circuit_reserved,
+			tvb, offset, 1, octet,
+			"Circuit type              : %s, reserved(0x%02x == 0)",
+				val_to_str(octet&ISIS_HELLO_CTYPE_MASK,
+					isis_hello_circuit_type_vals,
+					"Unknown (0x%x)"),
+				octet&ISIS_HELLO_CT_RESERVED_MASK
+			);
+	}
+	offset += 1;
+
+	if (tree) {
+		source_id = tvb_get_ptr(tvb, offset, id_length);
+		proto_tree_add_bytes_format(hello_tree, hf_isis_hello_source_id, tvb,
+			            offset, id_length, source_id,
+			            "System-ID {Sender of PDU} : %s", 
+			            print_system_id( source_id, id_length ) );
+	}
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_append_fstr(pinfo->cinfo, COL_INFO, ", System-ID: %s",
+			print_system_id( tvb_get_ptr(tvb, offset, id_length), id_length ) );
+	}
+	offset += id_length;
+
+	if (tree) {
+		proto_tree_add_item(hello_tree, hf_isis_hello_holding_timer, tvb,
+			            offset, 2, FALSE);
+	}
+	offset += 2;
+
+	pdu_length = tvb_get_ntohs(tvb, offset);
+	if (tree) {
+		proto_tree_add_uint(hello_tree, hf_isis_hello_pdu_length, tvb,
+			            offset, 2, pdu_length);
+	}
+	offset += 2;
+
+	if (hello_type == ISIS_TYPE_PTP_HELLO) {
+		if (tree) {
+			proto_tree_add_item(hello_tree, hf_isis_hello_local_circuit_id, tvb,
+				         offset, 1, FALSE );
+		}
+		offset += 1;
+	} else {
+		if (tree) {
+			octet = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint_format(hello_tree, hf_isis_hello_priority_reserved, tvb,
+				    offset, 1, octet,
+				    "Priority                  : %d, reserved(0x%02x == 0)",
+					octet&ISIS_HELLO_PRIORITY_MASK,
+					octet&ISIS_HELLO_P_RESERVED_MASK );
+		}
+		offset += 1;
+
+		if (tree) {
+			lan_id = tvb_get_ptr(tvb, offset, id_length+1);
+			proto_tree_add_bytes_format(hello_tree, hf_isis_hello_lan_id, tvb,
+				     offset, id_length + 1, lan_id,
+					 "System-ID {Designated IS} : %s",
+					      print_system_id( lan_id, id_length + 1 ) );
+		}
+		offset += id_length + 1;
+	}
+
+	len = pdu_length;
+	len -= header_length;
+	if (len < 0) {
+		isis_dissect_unknown(tvb, tree, offset,
+			"Packet header length %d went beyond packet",
+			header_length );
+		return;
+	}
+	/*
+	 * Now, we need to decode our CLVs.  We need to pass in
+	 * our list of valid ones!
+	 */
+	if (hello_type == ISIS_TYPE_L1_HELLO){
+		isis_dissect_clvs(tvb, hello_tree, offset,
+			clv_l1_hello_opts, len, id_length,
+			ett_isis_hello_clv_unknown);
+	} else if (hello_type == ISIS_TYPE_L2_HELLO) {
+		isis_dissect_clvs(tvb, hello_tree, offset,
+			clv_l2_hello_opts, len, id_length,
+			ett_isis_hello_clv_unknown);
+	} else {
+		isis_dissect_clvs(tvb, hello_tree, offset,
+			clv_ptp_hello_opts, len, id_length,
+			ett_isis_hello_clv_unknown);
+	}
+}
+
+/*
+ * Name: isis_register_hello()
+ *
+ * Description:
+ *	Register our protocol sub-sets with protocol manager.
+ *
+ * Input:
+ *	int : protocol index for the ISIS protocol
+ *
+ * Output:
+ *	void
+ */
+void
+isis_register_hello(int proto_isis) {
+	static hf_register_info hf[] = {
+		{ &hf_isis_hello_circuit_reserved,
+		{ "Circuit type              ", "isis.hello.circuit_type",
+			FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_source_id,
+		{ "SystemID{ Sender of PDU } ", "isis.hello.source_id",
+			FT_BYTES, BASE_HEX, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_holding_timer,
+		{ "Holding timer             ", "isis.hello.holding_timer",
+			FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_pdu_length,
+		{ "PDU length                ", "isis.hello.pdu_length",
+			FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_priority_reserved,
+		 { "Priority                 ", "isis.hello.priority",
+			FT_UINT8, BASE_DEC, NULL, ISIS_HELLO_P_RESERVED_MASK, "", HFILL }},
+
+		{ &hf_isis_hello_lan_id,
+		{ "SystemID{ Designated IS } ", "isis.hello.lan_id",
+			FT_BYTES, BASE_DEC, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_local_circuit_id,
+		{ "Local circuit ID          ", "isis.hello.local_circuit_id",
+			FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_clv_ipv4_int_addr,
+		{ "IPv4 interface address    ", "isis.hello.clv_ipv4_int_addr",
+			FT_IPv4, BASE_NONE, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_clv_ipv6_int_addr,
+		{ "IPv6 interface address    ", "isis.hello.clv_ipv6_int_addr",
+			FT_IPv6, BASE_NONE, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_clv_ptp_adj,
+		{ "Point-to-point Adjacency  ", "isis.hello.clv_ptp_adj",
+			FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }},
+
+		{ &hf_isis_hello_clv_mt,
+		{ "MT-ID                     ", "isis.hello.clv_mt",
+			FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL }},
+	};
+	static gint *ett[] = {
+		&ett_isis_hello,
+		&ett_isis_hello_clv_area_addr,
+		&ett_isis_hello_clv_is_neighbors,
+		&ett_isis_hello_clv_padding,
+		&ett_isis_hello_clv_unknown,
+		&ett_isis_hello_clv_nlpid,
+		&ett_isis_hello_clv_authentication,
+		&ett_isis_hello_clv_ip_authentication,
+		&ett_isis_hello_clv_ipv4_int_addr,
+		&ett_isis_hello_clv_ipv6_int_addr,
+		&ett_isis_hello_clv_ptp_adj,
+		&ett_isis_hello_clv_mt,
+		&ett_isis_hello_clv_restart,
+		&ett_isis_hello_clv_checksum
+	};
+
+	proto_register_field_array(proto_isis, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}