epan/dissectors/packet-bofl.c

   1 /* packet-bofl.c
   2  * Routines for Wellfleet BOFL dissection
   3  * Wellfleet -> Baynetworks -> Nortel -> Avaya -> Extremenetworks
   4  * Protocol is now called Simple Loop Protection Protocol (SLPP)
   5  * Author: Endoh Akira (endoh@netmarks.co.jp)
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@unicom.net>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-or-later
  12  *
  13  * The following information was copied from
  14  * http://web.archive.org/web/20150608035209/http://www.protocols.com/pbook/bridge.htm#WellfleetBOFL
  15  *
  16  * The Wellfleet Breath of Life (BOFL) protocol is used as a line sensing
  17  * protocol on:
  18  *
  19  * - Ethernet LANs to detect transmitter jams.
  20  * - Synchronous lines running WFLT STD protocols to determine if the line
  21  *   is up.
  22  * - Dial backup PPP lines.
  23  *
  24  * The frame format of Wellfleet BOFL is shown following the Ethernet header
  25  * in the following illustration:
  26  *
  27  *  Destination   Source    8102    PDU   Sequence   Padding
  28  *       6           6        2      4       4       n bytes
  29  */
  30
  31 /* From the above link:
  32  *
  33  * Wellfleet BOFL
  34  *
  35  * The Wellfleet Breath of Life (BOFL) protocol is used as a line sensing protocol on:
  36  *
  37  * Ethernet LANs to detect transmitter jams.
  38  * Synchronous lines running WFLT STD protocols to determine if the line is up.
  39  * Dial backup PPP lines.
  40  * The frame format of Wellfleet BOFL is shown following the Ethernet header in the following illustration:
  41  *
  42  * Destination | Source |8102 | PDU | Sequence | Padding
  43  *  6          |  6     | 2   |  4  |  4       | n bytes
  44  * <-------------------------->
  45  *       Ethernet Header
  46  *
  47  * 8102
  48  * EtherType (0x8102 for Wellfleet BOFL frames).
  49  *
  50  * PDU
  51  * PDU field normally equals 0x01010000, but may equal 0x01011111 in some new releases on synchronous links.
  52  *
  53  * Sequence
  54  * 4-byte sequence field is an incremental counter.
  55  *
  56  * Padding
  57  * Padding to fill out the frame to 64 bytes.
  58  */
  59
  60 #include "config.h"
  61
  62 #include <epan/packet.h>
  63
  64 #define ETHER_TYPE_SLPP 0x8102
  65 #define BOFL_MIN_LEN    8
  66
  67 void proto_register_bofl(void);
  68 void proto_reg_handoff_bofl(void);
  69
  70 static dissector_handle_t bofl_handle;
  71
  72 /* Initialize the protocol and registered fields */
  73 static int proto_bofl;
  74 static int hf_bofl_pdu;
  75 static int hf_bofl_sequence;
  76 static int hf_bofl_padding;
  77
  78 /* Initialize the subtree pointers */
  79 static int ett_bofl;
  80
  81 /* Code to actually dissect the packets */
  82 static int
  83 dissect_bofl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  84 {
  85     proto_item  *ti;
  86     proto_tree  *bofl_tree;
  87     int         len;
  88     uint32_t    pdu, sequence;
  89
  90     col_set_str(pinfo->cinfo, COL_PROTOCOL, "BOFL");
  91
  92     col_clear(pinfo->cinfo, COL_INFO);
  93
  94     ti = proto_tree_add_item(tree, proto_bofl, tvb, 0, -1, ENC_NA);
  95     bofl_tree = proto_item_add_subtree(ti, ett_bofl);
  96
  97     pdu = tvb_get_ntohl(tvb, 0);
  98     col_add_fstr(pinfo->cinfo, COL_INFO,
  99         "PDU: 0x%08x", pdu);
 100     proto_tree_add_uint(bofl_tree, hf_bofl_pdu, tvb, 0, 4, pdu);
 101
 102     sequence = tvb_get_ntohl(tvb, 4);
 103
 104     col_append_fstr(pinfo->cinfo, COL_INFO,
 105         " Sequence: %u", sequence);
 106
 107     proto_tree_add_uint(bofl_tree, hf_bofl_sequence, tvb, 4, 4, sequence);
 108
 109     len = tvb_reported_length_remaining(tvb, 8);
 110     if (len > 0)
 111         proto_tree_add_item(bofl_tree, hf_bofl_padding, tvb, 8, -1, ENC_NA);
 112
 113     return tvb_captured_length(tvb);
 114 }
 115
 116
 117 void
 118 proto_register_bofl(void)
 119 {
 120     static hf_register_info hf[] = {
 121         { &hf_bofl_pdu,
 122           { "PDU", "bofl.pdu",
 123             FT_UINT32, BASE_HEX, NULL, 0,
 124             "PDU; normally equals 0x01010000 or 0x01011111", HFILL }
 125         },
 126         { &hf_bofl_sequence,
 127           { "Sequence", "bofl.sequence",
 128             FT_UINT32, BASE_DEC, NULL, 0,
 129             "incremental counter", HFILL }
 130         },
 131         { &hf_bofl_padding,
 132           { "Padding", "bofl.padding",
 133             FT_BYTES, BASE_NONE, NULL, 0,
 134             NULL, HFILL }
 135         }
 136     };
 137
 138     static int *ett[] = {
 139         &ett_bofl,
 140     };
 141
 142     proto_bofl = proto_register_protocol("Wellfleet Breath of Life",
 143                                          "BOFL", "bofl");
 144     proto_register_field_array(proto_bofl, hf, array_length(hf));
 145     proto_register_subtree_array(ett, array_length(ett));
 146
 147     bofl_handle = register_dissector("bofl", dissect_bofl, proto_bofl);
 148 }
 149
 150
 151 void
 152 proto_reg_handoff_bofl(void)
 153 {
 154     dissector_add_uint("ethertype", ETHER_TYPE_SLPP, bofl_handle);
 155 }
 156
 157 /*
 158  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 159  *
 160  * Local variables:
 161  * c-basic-offset: 4
 162  * tab-width: 8
 163  * indent-tabs-mode: nil
 164  * End:
 165  *
 166  * vi: set shiftwidth=4 tabstop=8 expandtab:
 167  * :indentSize=4:tabSize=8:noTabs=true:
 168  */