epan/dissectors/packet-llt.c

   1 /* packet-llt.c
   2  * Routines for Veritas Low Latency Transport (LLT) dissection
   3  * Copyright 2006, Stephen Fisher (see AUTHORS file)
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29
  30 #include <epan/packet.h>
  31 #include <epan/prefs.h>
  32 #include <epan/etypes.h>
  33
  34 static const value_string message_type_vs[] = {
  35   { 0x0a, "heartbeat" },
  36   { 0, NULL}
  37 };
  38
  39 /* Forward declaration we need below */
  40 void proto_reg_handoff_llt(void);
  41
  42 /* Variables for our preferences */
  43 static guint preference_alternate_ethertype = 0x0;
  44
  45 /* Initialize the protocol and registered fields */
  46 static int proto_llt = -1;
  47
  48 static int hf_llt_cluster_num = -1;
  49 static int hf_llt_node_id = -1;
  50 static int hf_llt_message_type = -1;
  51 static int hf_llt_sequence_num = -1;
  52 static int hf_llt_message_time = -1;
  53
  54 /* Initialize the subtree pointers */
  55 static gint ett_llt = -1;
  56
  57 /* Code to actually dissect the packets */
  58 static void
  59 dissect_llt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  60 {
  61         /* Set up structures needed to add the protocol subtree and manage it */
  62         proto_item *ti;
  63         proto_tree *llt_tree;
  64         guint8 message_type;
  65
  66         /* Make entries in Protocol column and Info column on summary display */
  67         col_set_str(pinfo->cinfo, COL_PROTOCOL, "LLT");
  68
  69         message_type = tvb_get_guint8(tvb, 3);
  70
  71         col_add_fstr(pinfo->cinfo, COL_INFO, "Message type: %s", val_to_str(message_type, message_type_vs, "Unknown (0x%02x)"));
  72
  73         ti = proto_tree_add_item(tree, proto_llt, tvb, 0, -1, ENC_NA);
  74         llt_tree = proto_item_add_subtree(ti, ett_llt);
  75
  76         proto_tree_add_item(llt_tree, hf_llt_cluster_num, tvb, 2, 1, ENC_BIG_ENDIAN);
  77         proto_tree_add_item(llt_tree, hf_llt_message_type, tvb, 3, 1, ENC_BIG_ENDIAN);
  78         proto_tree_add_item(llt_tree, hf_llt_node_id, tvb, 7, 1, ENC_BIG_ENDIAN);
  79         proto_tree_add_item(llt_tree, hf_llt_sequence_num, tvb, 24, 4, ENC_BIG_ENDIAN);
  80         proto_tree_add_item(llt_tree, hf_llt_message_time, tvb, 40, 4, ENC_BIG_ENDIAN);
  81
  82 }
  83
  84 /* Register the protocol with Wireshark */
  85 void
  86 proto_register_llt(void)
  87 {
  88         module_t *llt_module;
  89
  90         static hf_register_info hf[] = {
  91
  92                 { &hf_llt_cluster_num,  { "Cluster number", "llt.cluster_num",
  93                                           FT_UINT8, BASE_DEC, NULL, 0,
  94                                           "Cluster number that this node belongs to", HFILL } },
  95
  96                 { &hf_llt_message_type, { "Message type", "llt.message_type",
  97                                           FT_UINT8, BASE_HEX, VALS(message_type_vs), 0,
  98                                           "Type of LLT message contained in this frame", HFILL } },
  99
 100                 { &hf_llt_node_id,      { "Node ID", "llt.node_id",
 101                                           FT_UINT8, BASE_DEC, NULL, 0,
 102                                           "Number identifying this node within the cluster", HFILL } },
 103
 104                 { &hf_llt_sequence_num, { "Sequence number", "llt.sequence_num",
 105                                           FT_UINT32, BASE_DEC, NULL, 0,
 106                                           "Sequence number of this frame", HFILL } },
 107
 108                 { &hf_llt_message_time, { "Message time", "llt.message_time",
 109                                           FT_UINT32, BASE_DEC, NULL, 0,
 110                                           "Number of ticks since this node was last rebooted", HFILL } }
 111         };
 112
 113         /* Setup protocol subtree array */
 114         static gint *ett[] = {
 115                 &ett_llt,
 116         };
 117
 118         /* Register the protocol name and description */
 119         proto_llt = proto_register_protocol("Veritas Low Latency Transport (LLT)", "LLT", "llt");
 120
 121         /* Required function calls to register the header fields and subtrees used */
 122         proto_register_field_array(proto_llt, hf, array_length(hf));
 123         proto_register_subtree_array(ett, array_length(ett));
 124
 125         /* Register preferences module */
 126         llt_module = prefs_register_protocol(proto_llt, proto_reg_handoff_llt);
 127
 128         /* Register our preferences */
 129         prefs_register_uint_preference(llt_module, "alternate_ethertype", "Alternate ethertype value (in hex)",
 130                                        "Dissect this ethertype as LLT traffic in addition to the default, 0xCAFE.",
 131                                        16, &preference_alternate_ethertype); /* A base-16 (hexadecimal) value */
 132
 133 }
 134
 135
 136 void
 137 proto_reg_handoff_llt(void)
 138 {
 139         static gboolean initialized = FALSE;
 140         static dissector_handle_t llt_handle;
 141         static guint preference_alternate_ethertype_last;
 142
 143         if (!initialized) {
 144                 llt_handle = create_dissector_handle(dissect_llt, proto_llt);
 145                 dissector_add_uint("ethertype", ETHERTYPE_LLT, llt_handle);
 146                 initialized = TRUE;
 147         } else {
 148                 if (preference_alternate_ethertype_last != 0x0) {
 149                         dissector_delete_uint("ethertype", preference_alternate_ethertype_last, llt_handle);
 150                 }
 151         }
 152
 153         /* Save the setting to see if it has changed later */
 154         preference_alternate_ethertype_last = preference_alternate_ethertype;
 155
 156         if (preference_alternate_ethertype != 0x0) {
 157                 /* Register the new ethertype setting */
 158                 dissector_add_uint("ethertype", preference_alternate_ethertype, llt_handle);
 159         }
 160 }