epan/dissectors/packet-lisp-data.c

   1 /* packet-lisp-data.c
   2  * Routines for LISP Data Message dissection
   3  * Copyright 2010, Lorand Jakab <lj@lispmon.net>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
  24  * USA.
  25  */
  26
  27 #include "config.h"
  28
  29 #include <glib.h>
  30
  31 #include <epan/packet.h>
  32 #include <epan/expert.h>
  33
  34 /* See RFC 6830 "Locator/ID Separation Protocol (LISP)" */
  35
  36 /*  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *  |N|L|E|V|I|flags|            Nonce/Map-Version                  |
  38  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *  |                 Instance ID/Locator Status Bits               |
  40  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  41  */
  42
  43 #define LISP_CONTROL_PORT       4342
  44 #define LISP_DATA_PORT          4341
  45 #define LISP_DATA_HEADER_LEN    8       /* Number of bytes in LISP data header */
  46
  47 #define LISP_DATA_FLAGS_WIDTH   8       /* Width (in bits) of the flags field */
  48 #define LISP_DATA_FLAG_N        0x80    /* Nonce present */
  49 #define LISP_DATA_FLAG_L        0x40    /* Locator-Status-Bits field enabled */
  50 #define LISP_DATA_FLAG_E        0x20    /* Echo-Nonce-Request */
  51 #define LISP_DATA_FLAG_V        0x10    /* Map-Version present */
  52 #define LISP_DATA_FLAG_I        0x08    /* Instance ID present */
  53 #define LISP_DATA_FLAG_RES      0x07    /* Reserved */
  54
  55 /* Initialize the protocol and registered fields */
  56 static int proto_lisp_data = -1;
  57 static int hf_lisp_data_flags = -1;
  58 static int hf_lisp_data_flags_nonce = -1;
  59 static int hf_lisp_data_flags_lsb = -1;
  60 static int hf_lisp_data_flags_enr = -1;
  61 static int hf_lisp_data_flags_mv = -1;
  62 static int hf_lisp_data_flags_iid = -1;
  63 static int hf_lisp_data_flags_res = -1;
  64 static int hf_lisp_data_nonce = -1;
  65 static int hf_lisp_data_mapver = -1;
  66 static int hf_lisp_data_srcmapver = -1;
  67 static int hf_lisp_data_dstmapver = -1;
  68 static int hf_lisp_data_iid = -1;
  69 static int hf_lisp_data_lsb = -1;
  70 static int hf_lisp_data_lsb8 = -1;
  71
  72 /* Initialize the subtree pointers */
  73 static gint ett_lisp_data = -1;
  74 static gint ett_lisp_data_flags = -1;
  75 static gint ett_lisp_data_mapver = -1;
  76
  77 static expert_field ei_lisp_data_flags_en_invalid = EI_INIT;
  78 static expert_field ei_lisp_data_flags_nv_invalid = EI_INIT;
  79
  80 static dissector_handle_t ipv4_handle;
  81 static dissector_handle_t ipv6_handle;
  82 static dissector_handle_t lisp_handle;
  83
  84 /* Code to actually dissect the packets */
  85 static int
  86 dissect_lisp_data(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
  87 {
  88     gint        offset = 0;
  89     guint8      flags;
  90     guint8      ip_ver;
  91     tvbuff_t   *next_tvb;
  92     proto_item *ti;
  93     proto_item *tif;
  94     proto_tree *lisp_data_tree;
  95     proto_tree *lisp_data_flags_tree;
  96
  97     /* Check if we have a LISP control packet */
  98     if (pinfo->destport == LISP_CONTROL_PORT)
  99         return call_dissector(lisp_handle, tvb, pinfo, tree);
 100
 101     /* Check that there's enough data */
 102     if (tvb_reported_length(tvb) < LISP_DATA_HEADER_LEN)
 103         return 0;
 104
 105     /* Make entries in Protocol column and Info column on summary display */
 106     col_set_str(pinfo->cinfo, COL_PROTOCOL, "LISP");
 107
 108     col_set_str(pinfo->cinfo, COL_INFO, "LISP Encapsulation Header");
 109
 110     /* create display subtree for the protocol */
 111     ti = proto_tree_add_item(tree, proto_lisp_data, tvb, 0,
 112             LISP_DATA_HEADER_LEN, ENC_NA);
 113
 114     lisp_data_tree = proto_item_add_subtree(ti, ett_lisp_data);
 115
 116     tif = proto_tree_add_item(lisp_data_tree,
 117             hf_lisp_data_flags, tvb, offset, 1, ENC_BIG_ENDIAN);
 118
 119     lisp_data_flags_tree = proto_item_add_subtree(tif, ett_lisp_data_flags);
 120
 121     proto_tree_add_item(lisp_data_flags_tree,
 122             hf_lisp_data_flags_nonce, tvb, offset, 1, ENC_BIG_ENDIAN);
 123     proto_tree_add_item(lisp_data_flags_tree,
 124             hf_lisp_data_flags_lsb, tvb, offset, 1, ENC_BIG_ENDIAN);
 125     proto_tree_add_item(lisp_data_flags_tree,
 126             hf_lisp_data_flags_enr, tvb, offset, 1, ENC_BIG_ENDIAN);
 127     proto_tree_add_item(lisp_data_flags_tree,
 128             hf_lisp_data_flags_mv, tvb, offset, 1, ENC_BIG_ENDIAN);
 129     proto_tree_add_item(lisp_data_flags_tree,
 130             hf_lisp_data_flags_iid, tvb, offset, 1, ENC_BIG_ENDIAN);
 131     proto_tree_add_item(lisp_data_flags_tree,
 132             hf_lisp_data_flags_res, tvb, offset, 1, ENC_BIG_ENDIAN);
 133
 134     flags = tvb_get_guint8(tvb, offset);
 135     offset += 1;
 136
 137     if (flags&LISP_DATA_FLAG_E && !(flags&LISP_DATA_FLAG_N)) {
 138         expert_add_info(pinfo, tif, &ei_lisp_data_flags_en_invalid);
 139     }
 140
 141     if (flags&LISP_DATA_FLAG_N) {
 142         if (flags&LISP_DATA_FLAG_V) {
 143             expert_add_info(pinfo, tif, &ei_lisp_data_flags_nv_invalid);
 144         }
 145         proto_tree_add_item(lisp_data_tree,
 146                 hf_lisp_data_nonce, tvb, offset, 3, ENC_BIG_ENDIAN);
 147     } else {
 148         if (flags&LISP_DATA_FLAG_V) {
 149             proto_item *tiv;
 150             proto_tree *lisp_data_mapver_tree;
 151
 152             tiv = proto_tree_add_item(lisp_data_tree,
 153                     hf_lisp_data_mapver, tvb, offset, 3, ENC_BIG_ENDIAN);
 154
 155             lisp_data_mapver_tree = proto_item_add_subtree(tiv, ett_lisp_data_mapver);
 156
 157             proto_tree_add_item(lisp_data_mapver_tree,
 158                     hf_lisp_data_srcmapver, tvb, offset, 3, ENC_BIG_ENDIAN);
 159             proto_tree_add_item(lisp_data_mapver_tree,
 160                     hf_lisp_data_dstmapver, tvb, offset, 3, ENC_BIG_ENDIAN);
 161         }
 162     }
 163     offset += 3;
 164
 165     if (flags&LISP_DATA_FLAG_I) {
 166         proto_tree_add_item(lisp_data_tree,
 167                 hf_lisp_data_iid, tvb, offset, 3, ENC_BIG_ENDIAN);
 168         offset += 3;
 169         if (flags&LISP_DATA_FLAG_L) {
 170             proto_tree_add_item(lisp_data_tree,
 171                     hf_lisp_data_lsb8, tvb, offset, 1, ENC_BIG_ENDIAN);
 172         }
 173         /*offset +=1;*/
 174     } else {
 175         if (flags&LISP_DATA_FLAG_L) {
 176             proto_tree_add_item(lisp_data_tree,
 177                     hf_lisp_data_lsb, tvb, offset, 4, ENC_BIG_ENDIAN);
 178             /*offset += 4;*/
 179         }
 180     }
 181
 182     /* Check if there is stuff left in the buffer, and return if not */
 183
 184     /* Determine if encapsulated packet is IPv4 or IPv6, and call dissector */
 185     next_tvb = tvb_new_subset_remaining(tvb, LISP_DATA_HEADER_LEN);
 186     ip_ver = tvb_get_bits8(next_tvb, 0, 4);
 187     switch (ip_ver) {
 188         case 4:
 189             call_dissector(ipv4_handle, next_tvb, pinfo, tree);
 190             return tvb_reported_length(tvb);
 191         case 6:
 192             call_dissector(ipv6_handle, next_tvb, pinfo, tree);
 193             return tvb_reported_length(tvb);
 194     }
 195
 196     /* Return the amount of data this dissector was able to dissect */
 197     return LISP_DATA_HEADER_LEN;
 198 }
 199
 200
 201 /* Register the protocol with Wireshark */
 202 void
 203 proto_register_lisp_data(void)
 204 {
 205     /* Setup list of header fields */
 206     static hf_register_info hf[] = {
 207         { &hf_lisp_data_flags,
 208                 { "Flags", "lisp-data.flags",
 209                 FT_UINT8, BASE_HEX, NULL, 0x0, "LISP Data Header Flags", HFILL }},
 210         { &hf_lisp_data_flags_nonce,
 211                 { "N bit (Nonce present)", "lisp-data.flags.nonce",
 212                 FT_BOOLEAN, LISP_DATA_FLAGS_WIDTH, TFS(&tfs_set_notset),
 213                 LISP_DATA_FLAG_N, NULL, HFILL }},
 214         { &hf_lisp_data_flags_lsb,
 215                 { "L bit (Locator-Status-Bits field enabled)", "lisp-data.flags.lsb",
 216                 FT_BOOLEAN, LISP_DATA_FLAGS_WIDTH, TFS(&tfs_set_notset),
 217                 LISP_DATA_FLAG_L, NULL, HFILL }},
 218         { &hf_lisp_data_flags_enr,
 219                 { "E bit (Echo-Nonce-Request)", "lisp-data.flags.enr",
 220                 FT_BOOLEAN, LISP_DATA_FLAGS_WIDTH, TFS(&tfs_set_notset),
 221                 LISP_DATA_FLAG_E, NULL, HFILL }},
 222         { &hf_lisp_data_flags_mv,
 223                 { "V bit (Map-Version present)", "lisp-data.flags.mv",
 224                 FT_BOOLEAN, LISP_DATA_FLAGS_WIDTH, TFS(&tfs_set_notset),
 225                 LISP_DATA_FLAG_V, NULL, HFILL }},
 226         { &hf_lisp_data_flags_iid,
 227                 { "I bit (Instance ID present)", "lisp-data.flags.iid",
 228                 FT_BOOLEAN, LISP_DATA_FLAGS_WIDTH, TFS(&tfs_set_notset),
 229                 LISP_DATA_FLAG_I, NULL, HFILL }},
 230         { &hf_lisp_data_flags_res,
 231                 { "Reserved", "lisp-data.flags.res",
 232                 FT_UINT8, BASE_HEX, NULL,
 233                 LISP_DATA_FLAG_RES, "Must be zero", HFILL }},
 234         { &hf_lisp_data_nonce,
 235                 { "Nonce", "lisp-data.nonce",
 236                 FT_UINT24, BASE_DEC_HEX, NULL, 0x0, NULL, HFILL }},
 237         { &hf_lisp_data_mapver,
 238                 { "Map-Version", "lisp-data.mapver",
 239                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL }},
 240         { &hf_lisp_data_srcmapver,
 241                 { "Source Map-Version", "lisp-data.srcmapver",
 242                 FT_UINT24, BASE_DEC, NULL, 0xFFF000, NULL, HFILL }},
 243         { &hf_lisp_data_dstmapver,
 244                 { "Destination Map-Version", "lisp-data.dstmapver",
 245                 FT_UINT24, BASE_DEC, NULL, 0x000FFF, NULL, HFILL }},
 246         { &hf_lisp_data_iid,
 247                 { "Instance ID", "lisp-data.iid",
 248                 FT_UINT24, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 249         { &hf_lisp_data_lsb,
 250                 { "Locator-Status-Bits", "lisp-data.lsb",
 251                 FT_UINT32, BASE_HEX, NULL, 0xFFFFFFFF, NULL, HFILL }},
 252         { &hf_lisp_data_lsb8,
 253                 { "Locator-Status-Bits", "lisp-data.lsb8",
 254                 FT_UINT8, BASE_HEX, NULL, 0xFF, NULL, HFILL }}
 255     };
 256
 257     /* Setup protocol subtree array */
 258     static gint *ett[] = {
 259         &ett_lisp_data,
 260         &ett_lisp_data_flags,
 261         &ett_lisp_data_mapver
 262     };
 263
 264     static ei_register_info ei[] = {
 265         { &ei_lisp_data_flags_en_invalid, { "lisp-data.flags.en_invalid", PI_PROTOCOL, PI_WARN, "Invalid flag combination: if E is set, N MUST be set", EXPFILL }},
 266         { &ei_lisp_data_flags_nv_invalid, { "lisp-data.flags.nv_invalid", PI_PROTOCOL, PI_WARN, "Invalid flag combination: N and V can't be set both", EXPFILL }},
 267     };
 268
 269     expert_module_t* expert_lisp_data;
 270
 271     /* Register the protocol name and description */
 272     proto_lisp_data = proto_register_protocol("Locator/ID Separation Protocol (Data)",
 273         "LISP Data", "lisp-data");
 274
 275     /* Required function calls to register the header fields and subtrees used */
 276     proto_register_field_array(proto_lisp_data, hf, array_length(hf));
 277     proto_register_subtree_array(ett, array_length(ett));
 278     expert_lisp_data = expert_register_protocol(proto_lisp_data);
 279     expert_register_field_array(expert_lisp_data, ei, array_length(ei));
 280 }
 281
 282 /* Simple form of proto_reg_handoff_lisp_data which can be used if there are
 283    no prefs-dependent registration function calls.
 284  */
 285
 286 void
 287 proto_reg_handoff_lisp_data(void)
 288 {
 289     dissector_handle_t lisp_data_handle;
 290
 291     lisp_data_handle = new_create_dissector_handle(dissect_lisp_data,
 292                              proto_lisp_data);
 293     dissector_add_uint("udp.port", LISP_DATA_PORT, lisp_data_handle);
 294     ipv4_handle = find_dissector("ip");
 295     ipv6_handle = find_dissector("ipv6");
 296     lisp_handle = find_dissector("lisp");
 297 }
 298
 299 /*
 300  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 301  *
 302  * Local variables:
 303  * c-basic-offset: 4
 304  * tab-width: 8
 305  * indent-tabs-mode: nil
 306  * End:
 307  *
 308  * vi: set shiftwidth=4 tabstop=8 expandtab:
 309  * :indentSize=4:tabSize=8:noTabs=true:
 310  */