epan/dissectors/packet-at-rl.c

   1 /* packet-at-rl.c
   2  * Dissector for Allied Telesis Resiliency Link Frames
   3  *
   4  * Copyright (c) 2024 by Martin Mayer <martin.mayer@m2-it-solutions.de>
   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
  13 #include "config.h"
  14 #include <epan/etypes.h>
  15 #include <epan/packet.h>
  16
  17 void proto_register_at_rl(void);
  18 void proto_reg_handoff_at_rl(void);
  19
  20 static dissector_handle_t at_rl_handle;
  21
  22 static int proto_at_rl;
  23
  24 #define AT_RL_FRAME_LEN 18
  25
  26 /* Fields */
  27 static int hf_at_rl_sequence;
  28 static int hf_at_rl_master;
  29 static int hf_at_rl_padding;
  30 static int hf_at_rl_vcsid;
  31 static int hf_at_rl_role_change;
  32
  33 static int ett_at_rl;
  34
  35 static int
  36 dissect_at_rl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
  37 {
  38
  39     /* Check if packet is destined to the Allied Telesis address (01:00:CD:FA:1B:AC) */
  40     uint8_t dst_mac[6] = {0x01, 0x00, 0xCD, 0xFA, 0x1B, 0xAC};
  41     address dst_addr = ADDRESS_INIT_NONE;
  42     set_address(&dst_addr, AT_ETHER, sizeof(dst_mac), &dst_mac);
  43
  44     if(!addresses_equal(&pinfo->dl_dst, &dst_addr))
  45         return 0;
  46
  47     col_set_str(pinfo->cinfo, COL_PROTOCOL, "AT RL");
  48     col_clear(pinfo->cinfo,COL_INFO);
  49     col_add_fstr(pinfo->cinfo, COL_INFO, "Seq: %u, VCS-ID: %u",
  50                     tvb_get_uint32(tvb, 0, ENC_BIG_ENDIAN),
  51                     tvb_get_uint16(tvb, 12, ENC_BIG_ENDIAN));
  52
  53     /* Frame has fixed length, so we can directly set tree and reported length (padding will most likely be added) */
  54     tvb_set_reported_length(tvb, AT_RL_FRAME_LEN);
  55
  56     proto_item *ti = proto_tree_add_item(tree, proto_at_rl, tvb, 0, AT_RL_FRAME_LEN, ENC_NA);
  57     proto_tree *at_rl_tree = proto_item_add_subtree(ti, ett_at_rl);
  58
  59     int offset = 0;
  60     proto_tree_add_item(at_rl_tree, hf_at_rl_sequence, tvb, offset, 4, ENC_BIG_ENDIAN);
  61     offset += 4;
  62
  63     proto_tree_add_item(at_rl_tree, hf_at_rl_master, tvb, offset, 6, ENC_NA);
  64     offset += 6;
  65
  66     proto_tree_add_item(at_rl_tree, hf_at_rl_padding, tvb, offset, 2, ENC_NA);
  67     offset += 2;
  68
  69     proto_tree_add_item(at_rl_tree, hf_at_rl_vcsid, tvb, offset, 2, ENC_BIG_ENDIAN);
  70     offset += 2;
  71
  72     proto_tree_add_item(at_rl_tree, hf_at_rl_role_change, tvb, offset, 4, ENC_TIME_SECS);
  73
  74     return AT_RL_FRAME_LEN;
  75 }
  76
  77 void
  78 proto_register_at_rl(void)
  79 {
  80     static hf_register_info hf[] = {
  81         { &hf_at_rl_sequence,
  82             { "Sequence No.", "atrl.sequence",
  83             FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
  84         },
  85         { &hf_at_rl_master,
  86             { "Active Master", "atrl.master",
  87             FT_ETHER, BASE_NONE, NULL, 0x0, NULL, HFILL }
  88         },
  89         { &hf_at_rl_padding,
  90             { "Padding", "atrl.padding",
  91             FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
  92         },
  93         { &hf_at_rl_vcsid,
  94             { "Virtual Chassis Stack ID", "atrl.vcsid",
  95             FT_UINT16, BASE_DEC_HEX, NULL, 0x0, NULL, HFILL }
  96         },
  97         { &hf_at_rl_role_change,
  98             { "Last Role Change", "atrl.role_change",
  99             FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0, NULL, HFILL }
 100         }
 101     };
 102
 103     static int *ett[] = {
 104         &ett_at_rl
 105     };
 106
 107     proto_at_rl = proto_register_protocol ("Allied Telesis Resiliency Link", "AT RL", "atrl");
 108
 109     proto_register_field_array(proto_at_rl, hf, array_length(hf));
 110     proto_register_subtree_array(ett, array_length(ett));
 111
 112     at_rl_handle = register_dissector("atrl", dissect_at_rl, proto_at_rl);
 113 }
 114
 115 void
 116 proto_reg_handoff_at_rl(void)
 117 {
 118     dissector_add_uint("ethertype", ETHERTYPE_ATRL, at_rl_handle);
 119 }
 120
 121 /*
 122  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 123  *
 124  * Local variables:
 125  * c-basic-offset: 4
 126  * tab-width: 8
 127  * indent-tabs-mode: nil
 128  * End:
 129  *
 130  * vi: set shiftwidth=4 tabstop=8 expandtab:
 131  * :indentSize=4:tabSize=8:noTabs=true:
 132  */