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  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #include "config.h"
  13
  14 #include <epan/packet.h>
  15 #include <epan/prefs.h>
  16 #include <epan/etypes.h>
  17
  18 void proto_register_llt(void);
  19 void proto_reg_handoff_llt(void);
  20
  21 static dissector_handle_t llt_handle;
  22
  23 static const value_string message_type_vs[] = {
  24         { 0x0a, "heartbeat" },
  25         { 0, NULL}
  26 };
  27
  28 /* Variables for our preferences */
  29 static unsigned preference_alternate_ethertype = 0x0;
  30
  31 /* Initialize the protocol and registered fields */
  32 static int proto_llt;
  33
  34 static int hf_llt_cluster_num;
  35 static int hf_llt_node_id;
  36 static int hf_llt_message_type;
  37 static int hf_llt_sequence_num;
  38 static int hf_llt_message_time;
  39 static int hf_llt_dst_node_id;
  40 static int hf_llt_src_node_id;
  41
  42 /* Initialize the subtree pointers */
  43 static int ett_llt;
  44
  45 /* Code to actually dissect the packets */
  46 static int
  47 dissect_llt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  48 {
  49         /* Set up structures needed to add the protocol subtree and manage it */
  50         proto_item *ti;
  51         proto_tree *llt_tree;
  52         uint8_t message_type;
  53         uint16_t magic;
  54
  55         /* Make entries in Protocol column and Info column on summary display */
  56         col_set_str(pinfo->cinfo, COL_PROTOCOL, "LLT");
  57
  58         magic = tvb_get_uint16(tvb, 0, ENC_BIG_ENDIAN);
  59         if(magic == 0x0602){ /* v2 ? */
  60
  61                 ti = proto_tree_add_item(tree, proto_llt, tvb, 0, -1, ENC_NA);
  62                 llt_tree = proto_item_add_subtree(ti, ett_llt);
  63
  64                 proto_tree_add_item(llt_tree, hf_llt_cluster_num, tvb, 2, 2, ENC_LITTLE_ENDIAN);
  65                 proto_tree_add_item(llt_tree, hf_llt_dst_node_id, tvb, 6, 1, ENC_LITTLE_ENDIAN);
  66                 proto_tree_add_item(llt_tree, hf_llt_src_node_id, tvb, 8, 1, ENC_LITTLE_ENDIAN);
  67
  68         } else {
  69                 message_type = tvb_get_uint8(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         return tvb_captured_length(tvb);
  83 }
  84
  85 /* Register the protocol with Wireshark */
  86 void
  87 proto_register_llt(void)
  88 {
  89         module_t *llt_module;
  90
  91         static hf_register_info hf[] = {
  92
  93                 { &hf_llt_cluster_num,  { "Cluster number", "llt.cluster_num",
  94                                           FT_UINT16, BASE_DEC, NULL, 0,
  95                                           "Cluster number that this node belongs to", HFILL } },
  96
  97                 { &hf_llt_message_type, { "Message type", "llt.message_type",
  98                                           FT_UINT8, BASE_HEX, VALS(message_type_vs), 0,
  99                                           "Type of LLT message contained in this frame", HFILL } },
 100
 101                 { &hf_llt_node_id,      { "Node ID", "llt.node_id",
 102                                           FT_UINT8, BASE_DEC, NULL, 0,
 103                                           "Number identifying this node within the cluster", HFILL } },
 104
 105                 { &hf_llt_sequence_num, { "Sequence number", "llt.sequence_num",
 106                                           FT_UINT32, BASE_DEC, NULL, 0,
 107                                           "Sequence number of this frame", HFILL } },
 108
 109                 { &hf_llt_message_time, { "Message time", "llt.message_time",
 110                                           FT_UINT32, BASE_DEC, NULL, 0,
 111                                           "Number of ticks since this node was last rebooted", HFILL } },
 112
 113                 { &hf_llt_dst_node_id,  { "Destination Node ID", "llt.dst.node_id",
 114                                           FT_UINT8, BASE_DEC, NULL, 0,
 115                                           "Number identifying destination node within the cluster", HFILL } },
 116
 117                 { &hf_llt_src_node_id,  { "Source Node ID", "llt.src.node_id",
 118                                           FT_UINT8, BASE_DEC, NULL, 0,
 119                                           "Number identifying source node within the cluster", HFILL } },
 120
 121         };
 122
 123         /* Setup protocol subtree array */
 124         static int *ett[] = {
 125                 &ett_llt,
 126         };
 127
 128         /* Register the protocol name and description */
 129         proto_llt = proto_register_protocol("Veritas Low Latency Transport (LLT)", "LLT", "llt");
 130
 131         /* Required function calls to register the header fields and subtrees used */
 132         proto_register_field_array(proto_llt, hf, array_length(hf));
 133         proto_register_subtree_array(ett, array_length(ett));
 134
 135         /* Register preferences module */
 136         llt_module = prefs_register_protocol(proto_llt, proto_reg_handoff_llt);
 137
 138         /* Register our preferences */
 139         prefs_register_uint_preference(llt_module, "alternate_ethertype", "Alternate ethertype value (in hex)",
 140                                        "Dissect this ethertype as LLT traffic in addition to the default, 0xCAFE.",
 141                                        16, &preference_alternate_ethertype); /* A base-16 (hexadecimal) value */
 142
 143         /* Register our dissector */
 144         llt_handle = register_dissector("llt", dissect_llt, proto_llt);
 145 }
 146
 147
 148 void
 149 proto_reg_handoff_llt(void)
 150 {
 151         static bool initialized = false;
 152         static unsigned preference_alternate_ethertype_last;
 153
 154         if (!initialized) {
 155                 dissector_add_uint("ethertype", ETHERTYPE_LLT, llt_handle);
 156                 initialized = true;
 157         } else {
 158                 if (preference_alternate_ethertype_last != 0x0) {
 159                         dissector_delete_uint("ethertype", preference_alternate_ethertype_last, llt_handle);
 160                 }
 161         }
 162
 163         /* Save the setting to see if it has changed later */
 164         preference_alternate_ethertype_last = preference_alternate_ethertype;
 165
 166         if (preference_alternate_ethertype != 0x0) {
 167                 /* Register the new ethertype setting */
 168                 dissector_add_uint("ethertype", preference_alternate_ethertype, llt_handle);
 169         }
 170 }
 171
 172 /*
 173  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 174  *
 175  * Local variables:
 176  * c-basic-offset: 8
 177  * tab-width: 8
 178  * indent-tabs-mode: t
 179  * End:
 180  *
 181  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 182  * :indentSize=8:tabSize=8:noTabs=false:
 183  */