LAT dissector.

Only 15 years later:

	https://www.wireshark.org/lists/ethereal-dev/200010/msg00070.html

as I clean up stuff I've had lying around for a while.

LAT spec found at bitsavers.org; further work can use that.

Change-Id: I486e4ab1ffb74d6e0b323202514cc352d63e9eef
Reviewed-on: https://code.wireshark.org/review/13118
Reviewed-by: Guy Harris <guy@alum.mit.edu>

3 files changed, 516 insertions, 0 deletions

diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index 34beb39e91..c9ec673f7c 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -922,6 +922,7 @@ set(DISSECTOR_SRC
 	dissectors/packet-lapdm.c
 	dissectors/packet-laplink.c
 	dissectors/packet-lapsat.c
+	dissectors/packet-lat.c
 	dissectors/packet-lbm.c
 	dissectors/packet-lbmc.c
 	dissectors/packet-lbmpdm.c
diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 22dc3f2c6b..5932e163da 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -843,6 +843,7 @@ DISSECTOR_SRC = \
 	packet-lapdm.c		\
 	packet-laplink.c	\
 	packet-lapsat.c		\
+	packet-lat.c		\
 	packet-lbm.c		\
 	packet-lbmc.c		\
 	packet-lbmpdm.c		\
diff --git a/epan/dissectors/packet-lat.c b/epan/dissectors/packet-lat.c
new file mode 100644
index 0000000000..90f9c3bf54
--- /dev/null
+++ b/epan/dissectors/packet-lat.c
@@ -0,0 +1,514 @@
+/* packet-lat.c
+ * Routines for the disassembly of DEC's LAT protocol
+ *
+ * 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.
+ */
+ 
+#include "config.h"
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <glib.h>
+#include <epan/packet.h>
+#include "etypes.h"
+
+/*
+ * Information on LAT taken from the Linux "latd" at
+ *
+ *	https://sourceforge.net/projects/linux-decnet/
+ *
+ * See also
+ *
+ *	http://www.bitsavers.org/pdf/dec/ethernet/lat/AA-NL26A-TE_LAT_Specification_Jun89.pdf
+ */
+
+static int proto_lat = -1;
+static int hf_lat_cmd = -1;
+static int hf_lat_num_slots = -1;
+static int hf_lat_remote_connid = -1;
+static int hf_lat_local_connid = -1;
+static int hf_lat_seq_number = -1;
+static int hf_lat_ack_number = -1;
+static int hf_lat_slotcmd_local_session = -1;
+static int hf_lat_slotcmd_remote_session = -1;
+static int hf_lat_slotcmd_length = -1;
+static int hf_lat_slotcmd_command = -1;
+static int hf_lat_circuit_timer = -1;
+static int hf_lat_hiver = -1;
+static int hf_lat_lover = -1;
+static int hf_lat_latver = -1;
+static int hf_lat_latver_minor = -1;
+static int hf_lat_incarnation = -1;
+static int hf_lat_change_flags = -1;
+static int hf_lat_mtu = -1;
+static int hf_lat_multicast_timer = -1;
+static int hf_lat_node_status = -1;
+static int hf_lat_group_length = -1;
+static int hf_lat_groups = -1;
+static int hf_lat_nodename = -1;
+static int hf_lat_greeting = -1;
+static int hf_lat_num_services = -1;
+static int hf_lat_service_rating = -1;
+static int hf_lat_service_name = -1;
+static int hf_lat_service_ident = -1;
+static int hf_lat_unknown_command_data = -1;
+
+static gint ett_lat = -1;
+
+static dissector_handle_t data_handle;
+
+/* LAT commands. */
+#define LAT_CCMD_SREPLY		0x00 /* From Host */
+#define LAT_CCMD_SDATA		0x01 /* From Host: Response required */
+#define LAT_CCMD_SESSION	0x02 /* To Host */
+#define LAT_CCMD_CONNECT	0x06
+#define LAT_CCMD_CONREF		0x08 /* Connection Refused (I think) */
+#define LAT_CCMD_CONACK		0x04
+#define LAT_CCMD_DISCON		0x0A
+#define LAT_CCMD_SERVICE	0x28
+#define LAT_CCMD_ENQUIRE	0x38
+#define LAT_CCMD_ENQREPLY	0x3C
+
+static const value_string command_vals[] = {
+	{ LAT_CCMD_SREPLY,   "Session reply" },
+	{ LAT_CCMD_SDATA,    "Session data" },
+	{ LAT_CCMD_SESSION,  "Session" },
+	{ LAT_CCMD_CONNECT,  "Connect" },
+	{ LAT_CCMD_CONREF,   "Connection refused" },
+	{ LAT_CCMD_CONACK,   "Connection ACK" },
+	{ LAT_CCMD_DISCON,   "Disconnect" },
+	{ LAT_CCMD_SERVICE,  "Service" },
+	{ LAT_CCMD_ENQUIRE,  "Enquire" },
+	{ LAT_CCMD_ENQREPLY, "Enquire reply" },
+	{ 0,                 NULL },
+};
+
+static void dissect_lat_sreply(tvbuff_t *tvb, int offset, proto_tree *tree);
+
+static void dissect_lat_service(tvbuff_t *tvb, int offset, proto_tree *tree);
+
+static int dissect_lat_string(tvbuff_t *tvb, int offset, int hf,
+    proto_tree *tree);
+
+static guint dissect_lat_header(tvbuff_t *tvb, int offset, proto_tree *tree);
+
+static void dissect_lat_slots(tvbuff_t *tvb, int offset, guint num_slots,
+    proto_tree *tree);
+
+static int
+dissect_lat(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+	int offset = 0;
+	proto_item *ti; 
+	proto_tree *lat_tree = NULL;
+	guint8 command;
+
+	col_add_str(pinfo->cinfo, COL_PROTOCOL, "LAT");
+	col_clear(pinfo->cinfo, COL_INFO);
+
+	command = tvb_get_guint8(tvb, offset);
+
+	col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
+	    val_to_str(command, command_vals, "Unknown command (%02x)"));
+
+	if (tree) {
+		ti = proto_tree_add_item(tree, proto_lat, tvb, offset, -1,
+		    ENC_NA);
+		lat_tree = proto_item_add_subtree(ti, ett_lat);
+
+		/* LAT header */
+		proto_tree_add_uint(lat_tree, hf_lat_cmd, tvb, offset, 1,
+		    command);
+		offset += 1;
+
+		switch (command) {
+
+		case LAT_CCMD_SREPLY:
+			dissect_lat_sreply(tvb, offset, lat_tree);
+			break;
+
+#if 0
+		case LAT_CCMD_SDATA:
+			dissect_lat_header(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_SESSION:
+			dissect_lat_header(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_CONNECT:
+			dissect_lat_connect(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_CONREF:
+			dissect_lat_conref(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_CONACK:
+			dissect_lat_conack(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_DISCON:
+			dissect_lat_discon(tvb, offset, lat_tree);
+			break;
+#endif
+
+		case LAT_CCMD_SERVICE:
+			dissect_lat_service(tvb, offset, lat_tree);
+			break;
+
+#if 0
+		case LAT_CCMD_ENQUIRE:
+			dissect_lat_enquire(tvb, offset, lat_tree);
+			break;
+
+		case LAT_CCMD_ENQREPLY:
+			dissect_lat_enqreply(tvb, offset, lat_tree);
+			break;
+#endif
+
+		default:
+			proto_tree_add_item(lat_tree, hf_lat_unknown_command_data,
+			    tvb, offset, -1, ENC_NA);
+			break;
+		}
+
+	}
+	return tvb_captured_length(tvb);
+}
+
+static void
+dissect_lat_sreply(tvbuff_t *tvb, int offset, proto_tree *tree)
+{
+	guint8 num_slots;
+
+	num_slots = dissect_lat_header(tvb, offset, tree);
+	offset += 1 + 2 + 2 + 1 + 1;
+	dissect_lat_slots(tvb, offset, num_slots, tree);
+}
+
+static const value_string node_status_vals[] = {
+	{ 2, "Accepting connections" },
+	{ 3, "Not accepting connections" },
+	{ 0, NULL },
+};
+
+static void
+dissect_lat_service(tvbuff_t *tvb, int offset, proto_tree *tree)
+{
+	guint8 timer;
+	guint8 group_length;
+	guint8 num_services;
+	int i;
+
+	timer = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint_format(tree, hf_lat_circuit_timer, tvb,
+	    offset, 1, timer, "Circuit timer: %u milliseconds", timer*10);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_hiver, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_lover, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_latver, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_latver_minor, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_incarnation, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_change_flags, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_mtu, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+	offset += 2;
+
+	timer = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint_format(tree, hf_lat_multicast_timer, tvb,
+	    offset, 1, timer, "Multicast timer: %u seconds", timer);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_node_status, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	group_length = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint(tree, hf_lat_group_length, tvb, offset, 1,
+	    group_length);
+	offset += 1;
+
+	/* XXX - what are these? */
+	proto_tree_add_item(tree, hf_lat_groups, tvb, offset, group_length, ENC_NA);
+	offset += group_length;
+
+	offset = dissect_lat_string(tvb, offset, hf_lat_nodename, tree);
+
+	offset = dissect_lat_string(tvb, offset, hf_lat_greeting, tree);
+
+	num_services = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint(tree, hf_lat_num_services, tvb, offset, 1,
+	    num_services);
+	offset += 1;
+
+	for (i = 0; i < num_services; i++) {
+		proto_tree_add_item(tree, hf_lat_service_rating, tvb,
+		    offset, 1, ENC_LITTLE_ENDIAN);
+		offset += 1;
+		offset = dissect_lat_string(tvb, offset, hf_lat_service_name,
+		    tree);
+		offset = dissect_lat_string(tvb, offset, hf_lat_service_ident,
+		    tree);
+	}
+}
+
+static int
+dissect_lat_string(tvbuff_t *tvb, int offset, int hf, proto_tree *tree)
+{
+	proto_item *ti;
+
+	ti = proto_tree_add_item(tree, hf, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	return offset + proto_item_get_len(ti);
+}
+
+static guint
+dissect_lat_header(tvbuff_t *tvb, int offset, proto_tree *tree)
+{
+	guint8 num_slots;
+
+	num_slots = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint(tree, hf_lat_num_slots, tvb, offset, 1,
+	    num_slots);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_remote_connid, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+	offset += 2;
+
+	proto_tree_add_item(tree, hf_lat_local_connid, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+	offset += 2;
+
+	proto_tree_add_item(tree, hf_lat_seq_number, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	proto_tree_add_item(tree, hf_lat_ack_number, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+	offset += 1;
+
+	return num_slots;
+}
+
+static void
+dissect_lat_slots(tvbuff_t *tvb, int offset, guint num_slots,
+    proto_tree *tree)
+{
+	guint i;
+
+	for (i = 0; i < num_slots; i++) {
+		proto_tree_add_item(tree, hf_lat_slotcmd_local_session,
+		    tvb, offset, 1, ENC_LITTLE_ENDIAN);
+		offset += 1;
+
+		proto_tree_add_item(tree, hf_lat_slotcmd_remote_session,
+		    tvb, offset, 1, ENC_LITTLE_ENDIAN);
+		offset += 1;
+
+		proto_tree_add_item(tree, hf_lat_slotcmd_length, tvb,
+		    offset, 1, ENC_LITTLE_ENDIAN);
+		offset += 1;
+
+		proto_tree_add_item(tree, hf_lat_slotcmd_command, tvb,
+		    offset, 1, ENC_LITTLE_ENDIAN);
+		offset += 1;
+	}
+}
+
+void
+proto_register_lat(void)
+{
+	static hf_register_info hf[] = {
+	    { &hf_lat_cmd,
+		{ "Command", "lat.command", FT_UINT8, BASE_HEX,
+		  VALS(command_vals), 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_num_slots,
+		{ "Number of slots", "lat.num_slots", FT_UINT8, BASE_DEC,
+		  NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_remote_connid,
+		{ "Remote connection ID", "lat.remote_connid", FT_UINT16,
+		  BASE_HEX, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_local_connid,
+		{ "Local connection ID", "lat.local_connid", FT_UINT16,
+		  BASE_HEX, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_seq_number,
+		{ "Sequence number", "lat.seq_number", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_ack_number,
+		{ "Ack number", "lat.ack_number", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_slotcmd_local_session,
+		{ "Local session", "lat.slotcmd.local_session", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_slotcmd_remote_session,
+		{ "Remote session", "lat.slotcmd.remote_session", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_slotcmd_length,
+		{ "Length", "lat.slotcmd.length", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_slotcmd_command,
+		{ "Command", "lat.slotcmd.command", FT_UINT8,
+		  BASE_HEX, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_circuit_timer,
+		{ "Circuit timer", "lat.circuit_timer", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_hiver,
+		{ "Highest protocol version acceptable", "lat.hiver", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_lover,
+		{ "Lowest protocol version acceptable", "lat.lover", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_latver,
+		{ "LAT version number", "lat.latver", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_latver_minor,
+		{ "LAT minor version number (?)", "lat.latver_minor", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_incarnation,
+		{ "Message incarnation (?)", "lat.incarnation", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_change_flags,
+		{ "Change flags (?)", "lat.change_flags", FT_UINT8,
+		  BASE_HEX, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_mtu,
+		{ "MTU", "lat.mtu", FT_UINT16,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_multicast_timer,
+		{ "Multicast timer", "lat.multicast_timer", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_node_status,
+		{ "Node status", "lat.node_status", FT_UINT8,
+		  BASE_DEC, VALS(node_status_vals), 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_group_length,
+		{ "Group length", "lat.group_length", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_groups,
+		{ "Groups", "lat.groups", FT_BYTES,
+		  BASE_NONE, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_nodename,
+		{ "Node name", "lat.nodename", FT_UINT_STRING,
+		  0, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_greeting,
+		{ "Greeting", "lat.greeting", FT_UINT_STRING,
+		  0, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_num_services,
+		{ "Number of services", "lat.num_services", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_service_rating,
+		{ "Rating", "lat.service_rating", FT_UINT8,
+		  BASE_DEC, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_service_name,
+		{ "Service name", "lat.service.name", FT_UINT_STRING,
+		  0, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_service_ident,
+		{ "Service identification", "lat.service.ident", FT_UINT_STRING,
+		  0, NULL, 0x0,
+		  NULL, HFILL}},
+
+	    { &hf_lat_unknown_command_data,
+		{ "Unknown command data", "lat.unknown_command_data", FT_BYTES,
+		  0, NULL, 0x0,
+		  NULL, HFILL}},
+        };
+	static gint *ett[] = {
+		&ett_lat,
+	};
+
+	proto_lat = proto_register_protocol("Local Area Transport",
+	    "LAT", "lat");
+	proto_register_field_array(proto_lat, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_lat(void)
+{
+	dissector_handle_t lat_handle;
+
+        data_handle = find_dissector("data");
+        lat_handle = create_dissector_handle(dissect_lat, proto_lat);
+	dissector_add_uint("ethertype", ETHERTYPE_LAT, lat_handle);
+}