epan/dissectors/file-dlt.c

   1 /* file-dlt.c
   2  * DLT File Format.
   3  * By Dr. Lars Voelker <lars.voelker@technica-engineering.de>
   4  * Copyright 2022-2022 Dr. Lars Voelker
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  *
  12  * This dissector allows to parse DLT files.
  13  */
  14
  15  /*
  16   * Sources for specification:
  17   * https://www.autosar.org/fileadmin/standards/classic/21-11/AUTOSAR_SWS_DiagnosticLogAndTrace.pdf
  18   * https://www.autosar.org/fileadmin/standards/foundation/1-3/AUTOSAR_PRS_LogAndTraceProtocol.pdf
  19   * https://github.com/COVESA/dlt-viewer
  20   */
  21
  22 #include "config.h"
  23
  24 #include <epan/packet.h>
  25 #include <wsutil/array.h>
  26
  27 static int proto_dlt;
  28
  29 static int hf_dlt_file_magic;
  30 static int hf_dlt_file_tstamp_s;
  31 static int hf_dlt_file_tstamp_us;
  32 static int hf_dlt_file_ecuid;
  33
  34 static int hf_dlt_file_header_type;
  35 static int hf_dlt_file_message_counter;
  36 static int hf_dlt_file_length;
  37 static int hf_dlt_file_data;
  38
  39 static int ett_dlt;
  40 static int ett_dlt_item;
  41
  42 void proto_register_file_dlt(void);
  43 void proto_reg_handoff_file_dlt(void);
  44
  45 #define MAGIC_NUMBER_SIZE 4
  46 static const uint8_t dlt_file_magic[MAGIC_NUMBER_SIZE] = { 'D', 'L', 'T', 0x01 };
  47
  48 static int
  49 dissect_dlt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
  50     volatile int     offset = 0;
  51     proto_tree      *dlt_tree;
  52     proto_tree      *item_tree;
  53     proto_item      *ti;
  54     proto_item      *ti_item;
  55     uint32_t         len = 0;
  56
  57     if (tvb_captured_length(tvb) < 16 || tvb_memeql(tvb, 0, dlt_file_magic, MAGIC_NUMBER_SIZE) != 0) {
  58         /* does not start with DLT\x1, so this is not DLT it seems */
  59         return 0;
  60     }
  61
  62     ti = proto_tree_add_item(tree, proto_dlt, tvb, offset, -1, ENC_NA);
  63     dlt_tree = proto_item_add_subtree(ti, ett_dlt);
  64
  65     int tvb_length = tvb_captured_length(tvb);
  66
  67     while (offset + 20 <= tvb_length) {
  68         item_tree = proto_tree_add_subtree_format(dlt_tree, tvb, offset, -1, ett_dlt_item, &ti_item, "DLT Log Line");
  69         proto_tree_add_item(item_tree, hf_dlt_file_magic, tvb, offset, 4, ENC_ASCII | ENC_NA);
  70         offset += 4;
  71
  72         uint32_t tstamp_s = 0;
  73         proto_tree_add_item_ret_uint(item_tree, hf_dlt_file_tstamp_s, tvb, offset, 4, ENC_LITTLE_ENDIAN, &tstamp_s);
  74         offset += 4;
  75
  76         uint32_t tstamp_us = 0;
  77         proto_tree_add_item_ret_uint(item_tree, hf_dlt_file_tstamp_us, tvb, offset, 4, ENC_LITTLE_ENDIAN, &tstamp_us);
  78         offset += 4;
  79
  80         const uint8_t *ecuid;
  81         proto_tree_add_item_ret_string(item_tree, hf_dlt_file_ecuid, tvb, offset, 4, ENC_ASCII | ENC_NA, pinfo->pool, &ecuid);
  82         offset += 4;
  83
  84         proto_tree_add_item(item_tree, hf_dlt_file_header_type, tvb, offset, 1, ENC_NA);
  85         offset += 1;
  86
  87         unsigned counter = 0;
  88         proto_tree_add_item_ret_uint(item_tree, hf_dlt_file_message_counter, tvb, offset, 1, ENC_NA, &counter);
  89         offset += 1;
  90
  91         proto_tree_add_item_ret_uint(item_tree, hf_dlt_file_length, tvb, offset, 2, ENC_BIG_ENDIAN, &len);
  92         offset += 2;
  93
  94         proto_tree_add_item(item_tree, hf_dlt_file_data, tvb, offset, len - 4, ENC_NA);
  95         offset += (len - 4);
  96
  97         proto_item_set_end(ti_item, tvb, offset);
  98         proto_item_append_text(ti_item, " %3u %u.%06u ECU:%s Len:%u", counter, tstamp_s, tstamp_us, ecuid, len);
  99     }
 100
 101     return offset;
 102 }
 103
 104 static bool
 105 dissect_dlt_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) {
 106     return dissect_dlt(tvb, pinfo, tree, data) > 0;
 107 }
 108
 109 void
 110 proto_register_file_dlt(void) {
 111     static hf_register_info hf[] = {
 112         { &hf_dlt_file_magic,
 113             { "Magic", "file-dlt.magic", FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 114         { &hf_dlt_file_tstamp_s,
 115             { "Timestamp s", "file-dlt.timestamp_s", FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 116         { &hf_dlt_file_tstamp_us,
 117             { "Timestamp us", "file-dlt.timestamp_us", FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 118         { &hf_dlt_file_ecuid,
 119             { "ECU ID", "file-dlt.ecu_id", FT_STRING, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 120
 121         { &hf_dlt_file_header_type,
 122             { "Header Type", "file-dlt.header_type", FT_UINT8, BASE_HEX, NULL, 0x00, NULL, HFILL }},
 123         { &hf_dlt_file_message_counter,
 124             { "Message Counter", "file-dlt.msg_counter", FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 125         { &hf_dlt_file_length,
 126             { "Length", "file-dlt.length", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 127         { &hf_dlt_file_data,
 128             { "Data", "file-dlt.data", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 129     };
 130
 131     static int *ett[] = {
 132         &ett_dlt,
 133         &ett_dlt_item,
 134     };
 135
 136     proto_dlt = proto_register_protocol("DLT File Format", "File-DLT", "file-dlt");
 137     proto_register_field_array(proto_dlt, hf, array_length(hf));
 138     proto_register_subtree_array(ett, array_length(ett));
 139
 140     register_dissector("file-dlt", dissect_dlt, proto_dlt);
 141 }
 142
 143 void
 144 proto_reg_handoff_file_dlt(void) {
 145     heur_dissector_add("wtap_file", dissect_dlt_heur, "DLT File", "dlt_wtap", proto_dlt, HEURISTIC_ENABLE);
 146 }
 147
 148 /*
 149  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 150  *
 151  * Local variables:
 152  * c-basic-offset: 4
 153  * tab-width: 8
 154  * indent-tabs-mode: nil
 155  * End:
 156  *
 157  * vi: set shiftwidth=4 tabstop=8 expandtab:
 158  * :indentSize=4:tabSize=8:noTabs=true:
 159  */