epan/dissectors/packet-msnip.c

   1 /* packet-msnip.c   2001 Ronnie Sahlberg <See AUTHORS for email>
   2  * Routines for IGMP/MSNIP packet disassembly
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998 Gerald Combs
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10 /*
  11
  12
  13                         MSNIP
  14         code
  15
  16         0x23            x
  17         0x24            x
  18         0x25            x
  19
  20         MSNIP " Multicast Source Notification of Interest Protocol
  21         Defined in draft-ietf-idmr-igmp-msnip-00.txt
  22 */
  23
  24 #include "config.h"
  25
  26 #include <epan/packet.h>
  27 #include <epan/expert.h>
  28 #include <epan/to_str.h>
  29 #include "packet-igmp.h"
  30
  31 void proto_register_msnip(void);
  32 void proto_reg_handoff_msnip(void);
  33
  34 static dissector_handle_t msnip_handle;
  35
  36 static int proto_msnip;
  37 static int hf_checksum;
  38 static int hf_checksum_status;
  39 static int hf_type;
  40 static int hf_count;
  41 static int hf_holdtime;
  42 static int hf_groups;
  43 static int hf_maddr;
  44 static int hf_mask;
  45 static int hf_holdtime16;
  46 static int hf_genid;
  47 static int hf_rec_type;
  48
  49 static int ett_msnip;
  50 static int ett_groups;
  51
  52 static expert_field ei_checksum;
  53
  54 #define MC_ALL_IGMPV3_ROUTERS   0xe0000016
  55
  56 #define MSNIP_GM        0x23
  57 #define MSNIP_IS        0x24
  58 #define MSNIP_RMR       0x25
  59 static const value_string msnip_types[] = {
  60         {MSNIP_GM,      "Multicast Group Map"},
  61         {MSNIP_IS,      "Multicast Interest Solicitation"},
  62         {MSNIP_RMR,     "Multicast Receiver Membership Report"},
  63         {0,                                     NULL}
  64 };
  65
  66 #define MSNIP_RECTYPE_TRANSMIT  1
  67 #define MSNIP_RECTYPE_HOLD      2
  68 static const value_string msnip_rec_types[] = {
  69         {MSNIP_RECTYPE_TRANSMIT,        "Request to start transmitting group"},
  70         {MSNIP_RECTYPE_HOLD,            "Request to hold transmitting group"},
  71         {0,                                     NULL}
  72 };
  73
  74 static int
  75 dissect_msnip_rmr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
  76 {
  77         uint8_t count;
  78
  79         /* group count */
  80         count = tvb_get_uint8(tvb, offset);
  81         proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
  82         offset += 1;
  83
  84         /* checksum */
  85         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
  86         offset += 2;
  87
  88         while (count--) {
  89                 proto_tree *tree;
  90                 proto_item *item;
  91                 uint8_t rec_type;
  92                 int old_offset = offset;
  93
  94                 item = proto_tree_add_item(parent_tree, hf_groups,
  95                                 tvb, offset, -1, ENC_NA);
  96                 tree = proto_item_add_subtree(item, ett_groups);
  97
  98                 /* record type */
  99                 rec_type = tvb_get_uint8(tvb, offset);
 100                 proto_tree_add_uint(tree, hf_rec_type, tvb, offset, 1, rec_type);
 101                 offset += 1;
 102
 103                 /* skip 3 unused bytes */
 104                 offset += 3;
 105
 106                 /* multicast group */
 107                 proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
 108                 offset += 4;
 109
 110                 if (item) {
 111                         proto_item_set_text(item,"Group: %s %s",
 112                                 tvb_ip_to_str(pinfo->pool, tvb, offset-4),
 113                                 val_to_str(rec_type, msnip_rec_types,
 114                                         "Unknown Type:0x%02x"));
 115
 116                         proto_item_set_len(item, offset-old_offset);
 117                 }
 118         }
 119
 120         return offset;
 121 }
 122
 123 static int
 124 dissect_msnip_is(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 125 {
 126
 127         /* skip reserved byte */
 128         offset += 1;
 129
 130         /* checksum */
 131         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
 132         offset += 2;
 133
 134         /* 16 bit holdtime */
 135         proto_tree_add_item(parent_tree, hf_holdtime16, tvb, offset, 2, ENC_BIG_ENDIAN);
 136         offset += 2;
 137
 138         /* Generation ID */
 139         proto_tree_add_item(parent_tree, hf_genid, tvb, offset, 2, ENC_BIG_ENDIAN);
 140         offset += 2;
 141
 142         return offset;
 143 }
 144
 145
 146 static int
 147 dissect_msnip_gm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 148 {
 149         uint8_t count;
 150
 151         /* group count */
 152         count = tvb_get_uint8(tvb, offset);
 153         proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
 154         offset += 1;
 155
 156         /* checksum */
 157         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_status, &ei_checksum, pinfo, 0);
 158         offset += 2;
 159
 160         /* holdtime */
 161         proto_tree_add_uint(parent_tree, hf_holdtime, tvb, offset, 4, count);
 162         offset += 4;
 163
 164         while (count--) {
 165                 proto_tree *tree;
 166                 proto_item *item;
 167                 uint8_t masklen;
 168                 int old_offset = offset;
 169
 170                 item = proto_tree_add_item(parent_tree, hf_groups,
 171                                 tvb, offset, -1, ENC_NA);
 172                 tree = proto_item_add_subtree(item, ett_groups);
 173
 174                 /* multicast group */
 175                 proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, ENC_BIG_ENDIAN);
 176                 offset += 4;
 177
 178                 /* mask length */
 179                 masklen = tvb_get_uint8(tvb, offset);
 180                 proto_tree_add_uint(tree, hf_mask, tvb,
 181                         offset, 1, masklen);
 182                 offset += 1;
 183
 184                 /* skip 3 unused bytes */
 185                 offset += 3;
 186
 187                 if (item) {
 188                         proto_item_set_text(item,"Group: %s/%d",
 189                                 tvb_ip_to_str(pinfo->pool, tvb, offset - 8), masklen);
 190
 191                         proto_item_set_len(item, offset-old_offset);
 192                 }
 193         }
 194
 195         return offset;
 196 }
 197
 198
 199 /* This function is only called from the IGMP dissector */
 200 static int
 201 dissect_msnip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void* data _U_)
 202 {
 203         proto_tree *tree;
 204         proto_item *item;
 205         uint8_t type;
 206         int offset = 0;
 207         uint32_t dst = g_htonl(MC_ALL_IGMPV3_ROUTERS);
 208
 209         /* Shouldn't be destined for us */
 210         if ((pinfo->dst.type != AT_IPv4) || memcmp(pinfo->dst.data, &dst, 4))
 211                 return 0;
 212
 213         col_set_str(pinfo->cinfo, COL_PROTOCOL, "MSNIP");
 214         col_clear(pinfo->cinfo, COL_INFO);
 215
 216         item = proto_tree_add_item(parent_tree, proto_msnip, tvb, offset, -1, ENC_NA);
 217         tree = proto_item_add_subtree(item, ett_msnip);
 218
 219         type = tvb_get_uint8(tvb, offset);
 220         col_add_str(pinfo->cinfo, COL_INFO,
 221                         val_to_str(type, msnip_types,
 222                                 "Unknown Type:0x%02x"));
 223
 224         /* type of command */
 225         proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
 226         offset += 1;
 227
 228         switch (type) {
 229         case MSNIP_GM:
 230                 offset = dissect_msnip_gm(tvb, pinfo, tree, offset);
 231                 break;
 232         case MSNIP_IS:
 233                 offset = dissect_msnip_is(tvb, pinfo, tree, offset);
 234                 break;
 235         case MSNIP_RMR:
 236                 offset = dissect_msnip_rmr(tvb, pinfo, tree, offset);
 237                 break;
 238         }
 239
 240         if (item) {
 241                 proto_item_set_len(item, offset);
 242         }
 243
 244         return offset;
 245 }
 246
 247
 248 void
 249 proto_register_msnip(void)
 250 {
 251         static hf_register_info hf[] = {
 252                 { &hf_type,
 253                         { "Type", "msnip.type", FT_UINT8, BASE_HEX,
 254                           VALS(msnip_types), 0, "MSNIP Packet Type", HFILL }},
 255
 256                 { &hf_checksum,
 257                         { "Checksum", "msnip.checksum", FT_UINT16, BASE_HEX,
 258                           NULL, 0, "MSNIP Checksum", HFILL }},
 259
 260                 { &hf_checksum_status,
 261                         { "Checksum Status", "msnip.checksum.status", FT_UINT8, BASE_NONE,
 262                           VALS(proto_checksum_vals), 0x0, NULL, HFILL }},
 263
 264                 { &hf_count,
 265                         { "Count", "msnip.count", FT_UINT8, BASE_DEC,
 266                           NULL, 0, "MSNIP Number of groups", HFILL }},
 267
 268                 { &hf_holdtime,
 269                         { "Holdtime", "msnip.holdtime", FT_UINT32, BASE_DEC,
 270                           NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
 271
 272                 { &hf_groups,
 273                         { "Groups", "msnip.groups", FT_NONE, BASE_NONE,
 274                           NULL, 0, "MSNIP Groups", HFILL }},
 275
 276                 { &hf_maddr,
 277                         { "Multicast group", "msnip.maddr", FT_IPv4, BASE_NONE,
 278                           NULL, 0, "MSNIP Multicast Group", HFILL }},
 279
 280                 { &hf_mask,
 281                         { "Netmask", "msnip.netmask", FT_UINT8, BASE_DEC,
 282                           NULL, 0, "MSNIP Netmask", HFILL }},
 283
 284                 { &hf_holdtime16,
 285                         { "Holdtime", "msnip.holdtime16", FT_UINT16, BASE_DEC,
 286                           NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
 287
 288                 { &hf_genid,
 289                         { "Generation ID", "msnip.genid", FT_UINT16, BASE_DEC,
 290                           NULL, 0, "MSNIP Generation ID", HFILL }},
 291
 292                 { &hf_rec_type,
 293                         { "Record Type", "msnip.rec_type", FT_UINT8, BASE_DEC,
 294                           VALS(msnip_rec_types), 0, "MSNIP Record Type", HFILL }},
 295
 296         };
 297         static int *ett[] = {
 298                 &ett_msnip,
 299                 &ett_groups,
 300         };
 301
 302         static ei_register_info ei[] = {
 303                 { &ei_checksum, { "msnip.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
 304         };
 305
 306         expert_module_t* expert_msnip;
 307
 308         proto_msnip = proto_register_protocol("MSNIP: Multicast Source Notification of Interest Protocol", "MSNIP", "msnip");
 309         proto_register_field_array(proto_msnip, hf, array_length(hf));
 310         proto_register_subtree_array(ett, array_length(ett));
 311         expert_msnip = expert_register_protocol(proto_msnip);
 312         expert_register_field_array(expert_msnip, ei, array_length(ei));
 313
 314         msnip_handle = register_dissector("msnip", dissect_msnip, proto_msnip);
 315 }
 316
 317 void
 318 proto_reg_handoff_msnip(void)
 319 {
 320         dissector_add_uint("igmp.type", IGMP_TYPE_0x23, msnip_handle);
 321         dissector_add_uint("igmp.type", IGMP_TYPE_0x24, msnip_handle);
 322         dissector_add_uint("igmp.type", IGMP_TYPE_0x25, msnip_handle);
 323 }
 324
 325 /*
 326  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 327  *
 328  * Local variables:
 329  * c-basic-offset: 8
 330  * tab-width: 8
 331  * indent-tabs-mode: t
 332  * End:
 333  *
 334  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 335  * :indentSize=8:tabSize=8:noTabs=false:
 336  */