epan/dissectors/packet-slowprotocols.c

   1 /* packet-slowprotocols.c
   2  * Routines for EtherType (0x8809) Slow Protocols disassembly.
   3  * IEEE Std 802.3, Annex 57A
   4  *
   5  * Copyright 2002 Steve Housley <steve_housley@3com.com>
   6  * Copyright 2005 Dominique Bastien <dbastien@accedian.com>
   7  * Copyright 2009 Artem Tamazov <artem.tamazov@telllabs.com>
   8  * Copyright 2010 Roberto Morro <roberto.morro[AT]tilab.com>
   9  * Copyright 2014 Philip Rosenberg-Watt <p.rosenberg-watt[at]cablelabs.com.>
  10  *
  11  * Wireshark - Network traffic analyzer
  12  * By Gerald Combs <gerald@wireshark.org>
  13  * Copyright 1998 Gerald Combs
  14  *
  15  * SPDX-License-Identifier: GPL-2.0-or-later
  16  */
  17
  18 #include "config.h"
  19
  20 #include <epan/packet.h>
  21 #include <epan/etypes.h>
  22 #include <epan/slow_protocol_subtypes.h>
  23
  24 /* General declarations */
  25 void proto_register_slow_protocols(void);
  26 void proto_reg_handoff_slow_protocols(void);
  27
  28 static dissector_handle_t slow_protocols_handle;
  29
  30 static dissector_table_t slow_protocols_dissector_table;
  31
  32 static const value_string subtype_vals[] = {
  33     { LACP_SUBTYPE   , "LACP" },
  34     { MARKER_SUBTYPE , "Marker Protocol" },
  35     { OAM_SUBTYPE    , "OAM" },
  36     { OSSP_SUBTYPE   , "Organization Specific Slow Protocol" },
  37     { 0, NULL }
  38 };
  39
  40 /* Initialise the protocol and registered fields */
  41 static int proto_slow;
  42
  43 static int hf_slow_subtype;
  44
  45 /* Initialise the subtree pointers */
  46
  47 static int ett_slow;
  48
  49 /*
  50  * Name: dissect_slow_protocols
  51  *
  52  * Description:
  53  *    This function is used to dissect the slow protocols defined in IEEE802.3
  54  *    CSMA/CD. The current slow protocols subtypes are define in Annex 57A of
  55  *    the 802.3 document. In case of an unsupported slow protocol, we only
  56  *    fill the protocol and info columns.
  57  *
  58  * Input Arguments:
  59  *    tvb:   buffer associated with the rcv packet (see tvbuff.h).
  60  *    pinfo: structure associated with the rcv packet (see packet_info.h).
  61  *    tree:  the protocol tree associated with the rcv packet (see proto.h).
  62  *
  63  * Return Values:
  64  *    None
  65  */
  66 static int
  67 dissect_slow_protocols(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  68 {
  69     uint8_t     subtype;
  70     proto_tree *pdu_tree;
  71     proto_item *pdu_item;
  72     tvbuff_t   *next_tvb;
  73
  74     col_set_str(pinfo->cinfo, COL_PROTOCOL, "Slow Protocols");
  75     subtype = tvb_get_uint8(tvb, 0);
  76     col_add_fstr(pinfo->cinfo, COL_INFO, "Subtype = %u", subtype);
  77
  78     if (tree)
  79     {
  80         pdu_item = proto_tree_add_item(tree, proto_slow, tvb, 0, 1, ENC_NA);
  81         pdu_tree = proto_item_add_subtree(pdu_item, ett_slow);
  82
  83         /* Subtype */
  84         proto_tree_add_item(pdu_tree, hf_slow_subtype, tvb, 0, 1, ENC_BIG_ENDIAN);
  85     }
  86
  87     next_tvb = tvb_new_subset_remaining(tvb, 1);
  88     if (!dissector_try_uint_with_data(slow_protocols_dissector_table, subtype,
  89                                 next_tvb, pinfo, tree, true, NULL))
  90         call_data_dissector(next_tvb, pinfo, tree);
  91     set_actual_length(tvb, tvb_captured_length(next_tvb) + 1);
  92
  93     return tvb_captured_length(tvb);
  94 }
  95
  96
  97 /* Register the protocol with Wireshark */
  98 void
  99 proto_register_slow_protocols(void)
 100 {
 101 /* Setup list of header fields */
 102
 103     static hf_register_info hf[] = {
 104         { &hf_slow_subtype,
 105           { "Slow Protocols subtype",    "slow.subtype",
 106             FT_UINT8,    BASE_HEX,    VALS(subtype_vals),    0x0,
 107             NULL, HFILL }},
 108     };
 109
 110     /* Setup protocol subtree array */
 111
 112     static int *ett[] = {
 113         &ett_slow,
 114     };
 115
 116
 117     /* Register the protocol name and description */
 118
 119     proto_slow = proto_register_protocol("802.3 Slow protocols", "Slow Protocols", "slow");
 120
 121     /* Required function calls to register the header fields and subtrees used */
 122
 123     proto_register_field_array(proto_slow, hf, array_length(hf));
 124     proto_register_subtree_array(ett, array_length(ett));
 125
 126     /* Register the dissector handle */
 127     slow_protocols_handle = register_dissector("slow", dissect_slow_protocols, proto_slow);
 128
 129     /* subdissector code */
 130     slow_protocols_dissector_table = register_dissector_table("slow.subtype",
 131                                                               "Slow protocol subtype",
 132                                                                proto_slow, FT_UINT8, BASE_DEC);
 133 }
 134
 135 void
 136 proto_reg_handoff_slow_protocols(void)
 137 {
 138     dissector_add_uint("ethertype", ETHERTYPE_SLOW_PROTOCOLS, slow_protocols_handle);
 139 }
 140
 141 /*
 142  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 143  *
 144  * Local variables:
 145  * c-basic-offset: 4
 146  * tab-width: 8
 147  * indent-tabs-mode: nil
 148  * End:
 149  *
 150  * vi: set shiftwidth=4 tabstop=8 expandtab:
 151  * :indentSize=4:tabSize=8:noTabs=true:
 152  */