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  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24 /*
  25
  26
  27                         MSNIP
  28         code
  29
  30         0x23            x
  31         0x24            x
  32         0x25            x
  33
  34         MSNIP " Multicast Source Notification of Interest Protocol
  35         Defined in draft-ietf-idmr-igmp-msnip-00.txt
  36 */
  37
  38 #include "config.h"
  39
  40 #include <glib.h>
  41
  42 #include <epan/packet.h>
  43 #include <epan/to_str.h>
  44 #include "packet-igmp.h"
  45 #include "packet-msnip.h"
  46
  47
  48 static int proto_msnip = -1;
  49 static int hf_checksum = -1;
  50 static int hf_checksum_bad = -1;
  51 static int hf_type = -1;
  52 static int hf_count = -1;
  53 static int hf_holdtime = -1;
  54 static int hf_groups = -1;
  55 static int hf_maddr = -1;
  56 static int hf_mask = -1;
  57 static int hf_holdtime16 = -1;
  58 static int hf_genid = -1;
  59 static int hf_rec_type = -1;
  60
  61 static int ett_msnip = -1;
  62 static int ett_groups = -1;
  63
  64
  65 #define MSNIP_GM        0x23
  66 #define MSNIP_IS        0x24
  67 #define MSNIP_RMR       0x25
  68 static const value_string msnip_types[] = {
  69         {MSNIP_GM,      "Multicast Group Map"},
  70         {MSNIP_IS,      "Multicast Interest Solicitation"},
  71         {MSNIP_RMR,     "Multicast Receiver Membership Report"},
  72         {0,                                     NULL}
  73 };
  74
  75 #define MSNIP_RECTYPE_TRANSMIT  1
  76 #define MSNIP_RECTYPE_HOLD      2
  77 static const value_string msnip_rec_types[] = {
  78         {MSNIP_RECTYPE_TRANSMIT,        "Request to start transmitting group"},
  79         {MSNIP_RECTYPE_HOLD,            "Request to hold transmitting group"},
  80         {0,                                     NULL}
  81 };
  82
  83 static int
  84 dissect_msnip_rmr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
  85 {
  86         guint8 count;
  87
  88         /* group count */
  89         count = tvb_get_guint8(tvb, offset);
  90         proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
  91         offset += 1;
  92
  93         /* checksum */
  94         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
  95         offset += 2;
  96
  97         while (count--) {
  98                 proto_tree *tree;
  99                 proto_item *item;
 100                 guint8 rec_type;
 101                 guint32 maddr;
 102                 int old_offset = offset;
 103
 104                 item = proto_tree_add_item(parent_tree, hf_groups,
 105                                 tvb, offset, -1, ENC_NA);
 106                 tree = proto_item_add_subtree(item, ett_groups);
 107
 108                 /* record type */
 109                 rec_type = tvb_get_guint8(tvb, offset);
 110                 proto_tree_add_uint(tree, hf_rec_type, tvb, offset, 1, rec_type);
 111                 offset += 1;
 112
 113                 /* skip 3 unused bytes */
 114                 offset += 3;
 115
 116                 /* multicast group */
 117                 maddr = tvb_get_ipv4(tvb, offset);
 118                 proto_tree_add_ipv4(tree, hf_maddr, tvb, offset, 4,
 119                         maddr);
 120                 offset += 4;
 121
 122                 if (item) {
 123                         proto_item_set_text(item,"Group: %s %s",
 124                                 ip_to_str((guint8 *)&maddr),
 125                                 val_to_str(rec_type, msnip_rec_types,
 126                                         "Unknown Type:0x%02x"));
 127
 128                         proto_item_set_len(item, offset-old_offset);
 129                 }
 130         }
 131
 132         return offset;
 133 }
 134
 135 static int
 136 dissect_msnip_is(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 137 {
 138
 139         /* skip reserved byte */
 140         offset += 1;
 141
 142         /* checksum */
 143         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 144         offset += 2;
 145
 146         /* 16 bit holdtime */
 147         proto_tree_add_uint(parent_tree, hf_holdtime16, tvb, offset, 2, tvb_get_ntohs(tvb, offset));
 148         offset += 2;
 149
 150         /* Generation ID */
 151         proto_tree_add_uint(parent_tree, hf_genid, tvb, offset, 2, tvb_get_ntohs(tvb, offset));
 152         offset += 2;
 153
 154         return offset;
 155 }
 156
 157
 158 static int
 159 dissect_msnip_gm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 160 {
 161         guint8 count;
 162
 163         /* group count */
 164         count = tvb_get_guint8(tvb, offset);
 165         proto_tree_add_uint(parent_tree, hf_count, tvb, offset, 1, count);
 166         offset += 1;
 167
 168         /* checksum */
 169         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 170         offset += 2;
 171
 172         /* holdtime */
 173         proto_tree_add_uint(parent_tree, hf_holdtime, tvb, offset, 4, count);
 174         offset += 4;
 175
 176         while (count--) {
 177                 proto_tree *tree;
 178                 proto_item *item;
 179                 guint32 maddr;
 180                 guint8 masklen;
 181                 int old_offset = offset;
 182
 183                 item = proto_tree_add_item(parent_tree, hf_groups,
 184                                 tvb, offset, -1, ENC_NA);
 185                 tree = proto_item_add_subtree(item, ett_groups);
 186
 187                 /* multicast group */
 188                 maddr = tvb_get_ipv4(tvb, offset);
 189                 proto_tree_add_ipv4(tree, hf_maddr, tvb, offset, 4,
 190                         maddr);
 191                 offset += 4;
 192
 193                 /* mask length */
 194                 masklen = tvb_get_guint8(tvb, offset);
 195                 proto_tree_add_uint(tree, hf_mask, tvb,
 196                         offset, 1, masklen);
 197                 offset += 1;
 198
 199                 /* skip 3 unused bytes */
 200                 offset += 3;
 201
 202                 if (item) {
 203                         proto_item_set_text(item,"Group: %s/%d",
 204                                 ip_to_str((guint8 *)&maddr), masklen);
 205
 206                         proto_item_set_len(item, offset-old_offset);
 207                 }
 208         }
 209
 210         return offset;
 211 }
 212
 213
 214 /* This function is only called from the IGMP dissector */
 215 int
 216 dissect_msnip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 217 {
 218         proto_tree *tree;
 219         proto_item *item;
 220         guint8 type;
 221
 222         if (!proto_is_protocol_enabled(find_protocol_by_id(proto_msnip))) {
 223                 /* we are not enabled, skip entire packet to be nice
 224                    to the igmp layer. (so clicking on IGMP will display the data)
 225                  */
 226                 return offset+tvb_length_remaining(tvb, offset);
 227         }
 228
 229         item = proto_tree_add_item(parent_tree, proto_msnip, tvb, offset, -1, ENC_NA);
 230         tree = proto_item_add_subtree(item, ett_msnip);
 231
 232
 233         col_set_str(pinfo->cinfo, COL_PROTOCOL, "MSNIP");
 234         col_clear(pinfo->cinfo, COL_INFO);
 235
 236
 237         type = tvb_get_guint8(tvb, offset);
 238         col_add_str(pinfo->cinfo, COL_INFO,
 239                         val_to_str(type, msnip_types,
 240                                 "Unknown Type:0x%02x"));
 241
 242         /* type of command */
 243         proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
 244         offset += 1;
 245
 246         switch (type) {
 247         case MSNIP_GM:
 248                 offset = dissect_msnip_gm(tvb, pinfo, tree, offset);
 249                 break;
 250         case MSNIP_IS:
 251                 offset = dissect_msnip_is(tvb, pinfo, tree, offset);
 252                 break;
 253         case MSNIP_RMR:
 254                 offset = dissect_msnip_rmr(tvb, pinfo, tree, offset);
 255                 break;
 256         }
 257
 258         if (item) {
 259                 proto_item_set_len(item, offset);
 260         }
 261
 262         return offset;
 263 }
 264
 265
 266 void
 267 proto_register_msnip(void)
 268 {
 269         static hf_register_info hf[] = {
 270                 { &hf_type,
 271                         { "Type", "msnip.type", FT_UINT8, BASE_HEX,
 272                           VALS(msnip_types), 0, "MSNIP Packet Type", HFILL }},
 273
 274                 { &hf_checksum,
 275                         { "Checksum", "msnip.checksum", FT_UINT16, BASE_HEX,
 276                           NULL, 0, "MSNIP Checksum", HFILL }},
 277
 278                 { &hf_checksum_bad,
 279                         { "Bad Checksum", "msnip.checksum_bad", FT_BOOLEAN, BASE_NONE,
 280                           NULL, 0x0, "Bad MSNIP Checksum", HFILL }},
 281
 282                 { &hf_count,
 283                         { "Count", "msnip.count", FT_UINT8, BASE_DEC,
 284                           NULL, 0, "MSNIP Number of groups", HFILL }},
 285
 286                 { &hf_holdtime,
 287                         { "Holdtime", "msnip.holdtime", FT_UINT32, BASE_DEC,
 288                           NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
 289
 290                 { &hf_groups,
 291                         { "Groups", "msnip.groups", FT_NONE, BASE_NONE,
 292                           NULL, 0, "MSNIP Groups", HFILL }},
 293
 294                 { &hf_maddr,
 295                         { "Multicast group", "msnip.maddr", FT_IPv4, BASE_NONE,
 296                           NULL, 0, "MSNIP Multicast Group", HFILL }},
 297
 298                 { &hf_mask,
 299                         { "Netmask", "msnip.netmask", FT_UINT8, BASE_DEC,
 300                           NULL, 0, "MSNIP Netmask", HFILL }},
 301
 302                 { &hf_holdtime16,
 303                         { "Holdtime", "msnip.holdtime16", FT_UINT16, BASE_DEC,
 304                           NULL, 0, "MSNIP Holdtime in seconds", HFILL }},
 305
 306                 { &hf_genid,
 307                         { "Generation ID", "msnip.genid", FT_UINT16, BASE_DEC,
 308                           NULL, 0, "MSNIP Generation ID", HFILL }},
 309
 310                 { &hf_rec_type,
 311                         { "Record Type", "msnip.rec_type", FT_UINT8, BASE_DEC,
 312                           VALS(msnip_rec_types), 0, "MSNIP Record Type", HFILL }},
 313
 314         };
 315         static gint *ett[] = {
 316                 &ett_msnip,
 317                 &ett_groups,
 318         };
 319
 320         proto_msnip = proto_register_protocol("MSNIP: Multicast Source Notification of Interest Protocol",
 321             "MSNIP", "msnip");
 322         proto_register_field_array(proto_msnip, hf, array_length(hf));
 323         proto_register_subtree_array(ett, array_length(ett));
 324 }
 325