epan/dissectors/packet-ripng.c

   1 /* packet-ripng.c
   2  * Routines for RIPng disassembly
   3  * (c) Copyright Jun-ichiro itojun Hagino <itojun@itojun.org>
   4  * derived from packet-rip.c
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * Enhance RIPng by Alexis La Goutte
  11  *
  12  * SPDX-License-Identifier: GPL-2.0-or-later
  13  *
  14  * References:
  15  * RFC2080: RIPng for IPv6
  16  */
  17
  18 #include "config.h"
  19
  20 #include <epan/packet.h>
  21 #include <epan/to_str.h>
  22
  23 void proto_register_ripng(void);
  24 void proto_reg_handoff_ripng(void);
  25
  26 static dissector_handle_t ripng_handle;
  27
  28 static int proto_ripng;
  29 static int hf_ripng_cmd;
  30 static int hf_ripng_version;
  31 static int hf_ripng_reserved;
  32
  33 static int hf_ripng_rte;
  34 static int hf_ripng_rte_ipv6_prefix;
  35 static int hf_ripng_rte_route_tag;
  36 static int hf_ripng_rte_prefix_length;
  37 static int hf_ripng_rte_metric;
  38
  39 static int ett_ripng;
  40 static int ett_ripng_rte;
  41
  42 #define UDP_PORT_RIPNG  521
  43
  44 #define RIP6_REQUEST    1
  45 #define RIP6_RESPONSE   2
  46
  47 static const value_string cmdvals[] = {
  48     { RIP6_REQUEST,  "Request" },
  49     { RIP6_RESPONSE, "Response" },
  50     { 0, NULL },
  51 };
  52
  53 static int
  54 dissect_ripng(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
  55     int offset = 0;
  56     proto_tree *ripng_tree = NULL, *rte_tree = NULL;
  57     proto_item *ti, *rte_ti;
  58
  59     col_set_str(pinfo->cinfo, COL_PROTOCOL, "RIPng");
  60     col_add_fstr(pinfo->cinfo, COL_INFO," Command %s, Version %u",
  61                  val_to_str(tvb_get_uint8(tvb, offset), cmdvals, "Unknown (%u)"),
  62                  tvb_get_uint8(tvb, offset +1));
  63
  64     if (tree) {
  65         ti = proto_tree_add_item(tree, proto_ripng, tvb, offset, -1, ENC_NA);
  66         ripng_tree = proto_item_add_subtree(ti, ett_ripng);
  67
  68         /* Command */
  69         proto_tree_add_item(ripng_tree, hf_ripng_cmd, tvb, offset, 1, ENC_BIG_ENDIAN);
  70         offset += 1;
  71
  72         /* Version */
  73         proto_tree_add_item(ripng_tree, hf_ripng_version, tvb, offset, 1, ENC_BIG_ENDIAN);
  74         offset += 1;
  75
  76         /* Reserved */
  77         proto_tree_add_item(ripng_tree, hf_ripng_reserved, tvb, offset, 2, ENC_NA);
  78         offset += 2;
  79
  80         /* Route Table Entry */
  81         while (tvb_reported_length_remaining(tvb, offset) > 0) {
  82
  83             rte_ti = proto_tree_add_item(ripng_tree, hf_ripng_rte, tvb, offset, 16 + 2 + 1 + 1, ENC_NA);
  84             rte_tree = proto_item_add_subtree(rte_ti, ett_ripng_rte);
  85
  86             /* IPv6 Prefix */
  87             proto_tree_add_item(rte_tree, hf_ripng_rte_ipv6_prefix, tvb, offset, 16, ENC_NA);
  88             proto_item_append_text(rte_ti, ": IPv6 Prefix: %s", tvb_ip6_to_str(pinfo->pool, tvb, offset));
  89             offset += 16;
  90
  91             /* Route Tag */
  92             proto_tree_add_item(rte_tree, hf_ripng_rte_route_tag, tvb, offset, 2, ENC_BIG_ENDIAN);
  93             offset += 2;
  94
  95             /* Prefix Length */
  96             proto_tree_add_item(rte_tree, hf_ripng_rte_prefix_length, tvb, offset, 1, ENC_BIG_ENDIAN);
  97             proto_item_append_text(rte_ti, "/%u", tvb_get_uint8(tvb, offset));
  98             offset += 1;
  99
 100             /* Metric */
 101             proto_tree_add_item(rte_tree, hf_ripng_rte_metric, tvb, offset, 1, ENC_BIG_ENDIAN);
 102             proto_item_append_text(rte_ti, " Metric: %u", tvb_get_uint8(tvb, offset));
 103             offset += 1;
 104         }
 105     }
 106     return tvb_captured_length(tvb);
 107 }
 108
 109 void
 110 proto_register_ripng(void)
 111 {
 112     static hf_register_info hf[] = {
 113         { &hf_ripng_cmd,
 114           { "Command",          "ripng.cmd",
 115             FT_UINT8, BASE_DEC, VALS(cmdvals), 0x0,
 116             "Used to specify the purpose of this message", HFILL }},
 117         { &hf_ripng_version,
 118           { "Version",          "ripng.version",
 119             FT_UINT8, BASE_DEC, NULL, 0x0,
 120             "Version of RIPng", HFILL }},
 121         { &hf_ripng_reserved,
 122           { "Reserved",         "ripng.reserved",
 123             FT_BYTES, BASE_NONE, NULL, 0x0,
 124             "Must be Zero", HFILL }},
 125         { &hf_ripng_rte,
 126           { "Route Table Entry",                "ripng.rte",
 127             FT_NONE, BASE_NONE, NULL, 0x0,
 128             NULL, HFILL }},
 129         { &hf_ripng_rte_ipv6_prefix,
 130           { "IPv6 Prefix",              "ripng.rte.ipv6_prefix",
 131             FT_IPv6, BASE_NONE, NULL, 0x0,
 132             "Destination", HFILL }},
 133         { &hf_ripng_rte_route_tag,
 134           { "Route Tag",                "ripng.rte.route_tag",
 135             FT_UINT16, BASE_HEX, NULL, 0x0,
 136             "Provides a method of separating internal RIPng routes (routes for networks within the RIPng routing domain) from external RIPng routes, which may have been imported from an EGP or another IGP", HFILL }},
 137
 138         { &hf_ripng_rte_prefix_length,
 139           { "Prefix Length",            "ripng.rte.prefix_length",
 140             FT_UINT8, BASE_DEC, NULL, 0x0,
 141             "The length in bits of the significant part of the prefix starting from the left of the prefix", HFILL }},
 142
 143         { &hf_ripng_rte_metric,
 144           { "Metric",           "ripng.rte.metric",
 145             FT_UINT8, BASE_DEC, NULL, 0x0,
 146             "The current metric for the destination; the value 16 (infinity) indicates that the destination is not reachable", HFILL }},
 147     };
 148
 149     static int *ett[] = {
 150         &ett_ripng,
 151         &ett_ripng_rte,
 152     };
 153
 154     proto_ripng = proto_register_protocol("RIPng", "RIPng", "ripng");
 155     proto_register_field_array(proto_ripng, hf, array_length(hf));
 156     proto_register_subtree_array(ett, array_length(ett));
 157
 158     ripng_handle = register_dissector("ripng", dissect_ripng, proto_ripng);
 159 }
 160
 161 void
 162 proto_reg_handoff_ripng(void)
 163 {
 164     dissector_add_uint_with_preference("udp.port", UDP_PORT_RIPNG, ripng_handle);
 165 }
 166
 167 /*
 168  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 169  *
 170  * Local variables:
 171  * c-basic-offset: 4
 172  * tab-width: 8
 173  * indent-tabs-mode: nil
 174  * End:
 175  *
 176  * vi: set shiftwidth=4 tabstop=8 expandtab:
 177  * :indentSize=4:tabSize=8:noTabs=true:
 178  */