epan/dissectors/packet-rgmp.c

   1 /* packet-rgmp.c
   2  * Routines for IGMP/RGMP packet disassembly
   3  * Copyright 2006 Jaap Keuter
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 /*
  13  Based on RFC3488
  14
  15  This is a setup for RGMP dissection, a simple protocol bolted on IGMP.
  16  */
  17
  18 #include "config.h"
  19
  20 #include <epan/packet.h>
  21 #include <epan/expert.h>
  22 #include "packet-igmp.h"
  23
  24 void proto_register_rgmp(void);
  25 void proto_reg_handoff_rgmp(void);
  26
  27 static int proto_rgmp;
  28 static int hf_type;
  29 static int hf_reserved;
  30 static int hf_checksum;
  31 static int hf_checksum_status;
  32 static int hf_maddr;
  33
  34 static int ett_rgmp;
  35
  36 static expert_field ei_checksum;
  37
  38 static dissector_handle_t rgmp_handle;
  39
  40 #define MC_RGMP 0xe0000019
  41
  42 static const value_string rgmp_types[] = {
  43     {IGMP_RGMP_LEAVE, "Leave"},
  44     {IGMP_RGMP_JOIN,  "Join"},
  45     {IGMP_RGMP_BYE,   "Bye"},
  46     {IGMP_RGMP_HELLO, "Hello"},
  47     {0, NULL}
  48 };
  49
  50 /* This function is only called from the IGMP dissector */
  51 static int
  52 dissect_rgmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void* data _U_)
  53 {
  54     proto_tree *tree;
  55     proto_item *item;
  56     uint8_t type;
  57     int offset = 0;
  58     uint32_t dst = g_htonl(MC_RGMP);
  59
  60     /* Shouldn't be destined for us */
  61     if ((pinfo->dst.type != AT_IPv4) || memcmp(pinfo->dst.data, &dst, 4))
  62         return 0;
  63
  64     col_set_str(pinfo->cinfo, COL_PROTOCOL, "RGMP");
  65     col_clear(pinfo->cinfo, COL_INFO);
  66
  67     item = proto_tree_add_item(parent_tree, proto_rgmp, tvb, offset, -1, ENC_NA);
  68     tree = proto_item_add_subtree(item, ett_rgmp);
  69
  70     type = tvb_get_uint8(tvb, offset);
  71     col_add_str(pinfo->cinfo, COL_INFO,
  72                 val_to_str(type, rgmp_types, "Unknown Type: 0x%02x"));
  73     proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
  74     offset += 1;
  75
  76     /* reserved */
  77     proto_tree_add_item(tree, hf_reserved, tvb, offset, 1, ENC_NA);
  78     offset += 1;
  79
  80     igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
  81     offset += 2;
  82
  83     proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
  84     offset += 4;
  85
  86     return offset;
  87 }
  88
  89
  90 void
  91 proto_register_rgmp(void)
  92 {
  93     static hf_register_info hf[] = {
  94         { &hf_type,
  95           { "Type", "rgmp.type", FT_UINT8, BASE_HEX,
  96             VALS(rgmp_types), 0, "RGMP Packet Type", HFILL }
  97         },
  98
  99         { &hf_reserved,
 100           { "Reserved", "rgmp.reserved", FT_UINT8, BASE_HEX,
 101             NULL, 0, "RGMP Reserved", HFILL }
 102         },
 103
 104         { &hf_checksum,
 105           { "Checksum", "rgmp.checksum", FT_UINT16, BASE_HEX,
 106             NULL, 0, NULL, HFILL }
 107         },
 108
 109         { &hf_checksum_status,
 110           { "Checksum Status", "rgmp.checksum.status", FT_UINT8, BASE_NONE,
 111             VALS(proto_checksum_vals), 0x0, NULL, HFILL }
 112         },
 113
 114         { &hf_maddr,
 115           { "Multicast group address", "rgmp.maddr", FT_IPv4, BASE_NONE,
 116             NULL, 0, NULL, HFILL }
 117         }
 118     };
 119
 120     static int *ett[] = {
 121         &ett_rgmp
 122     };
 123
 124     static ei_register_info ei[] = {
 125         { &ei_checksum, { "rgmp.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
 126     };
 127
 128     expert_module_t* expert_rgmp;
 129
 130     proto_rgmp = proto_register_protocol("Router-port Group Management Protocol", "RGMP", "rgmp");
 131     proto_register_field_array(proto_rgmp, hf, array_length(hf));
 132     proto_register_subtree_array(ett, array_length(ett));
 133     expert_rgmp = expert_register_protocol(proto_rgmp);
 134     expert_register_field_array(expert_rgmp, ei, array_length(ei));
 135
 136     rgmp_handle = register_dissector("rgmp", dissect_rgmp, proto_rgmp);
 137 }
 138
 139 void
 140 proto_reg_handoff_rgmp(void)
 141 {
 142     dissector_add_uint("igmp.type", IGMP_RGMP_HELLO, rgmp_handle);
 143     dissector_add_uint("igmp.type", IGMP_RGMP_BYE, rgmp_handle);
 144     dissector_add_uint("igmp.type", IGMP_RGMP_JOIN, rgmp_handle);
 145     dissector_add_uint("igmp.type", IGMP_RGMP_LEAVE, rgmp_handle);
 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  */