packet-lmi.c

   1 /* packet-lmi.c
   2  * Routines for Frame Relay Local Management Interface (LMI) disassembly
   3  * Copyright 2001, Jeffrey C. Foster <jfoste@woodward.com>
   4  *
   5  * $Id: packet-lmi.c,v 1.15 2003/10/17 23:44:06 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998
  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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  24  *
  25  * ToDo:
  26  *
  27  * References:
  28  *
  29  * http://www.techfest.com/networking/wan/frrel.htm
  30  * http://www.frforum.com/5000/Approved/FRF.1.2/frf1_2.pdf
  31  * http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm#xtocid18
  32  * http://www.net.aapt.com.au/techref/lmimess.htm
  33  * http://www.raleigh.ibm.com:80/cgi-bin/bookmgr/BOOKS/EZ305800/1.2.4.4
  34  */
  35
  36
  37 #ifdef HAVE_CONFIG_H
  38 # include "config.h"
  39 #endif
  40
  41 #include <stdio.h>
  42 #include <glib.h>
  43 #include <string.h>
  44 #include <epan/packet.h>
  45 #include "nlpid.h"
  46
  47 static int proto_lmi = -1;
  48 static int hf_lmi_call_ref = -1;
  49 static int hf_lmi_msg_type = -1;
  50 static int hf_lmi_inf_ele = -1;
  51 static int hf_lmi_inf_len = -1;
  52
  53 static int hf_lmi_rcd_type = -1;
  54 static int hf_lmi_send_seq = -1;
  55 static int hf_lmi_recv_seq = -1;
  56 static int hf_lmi_dlci_high = -1;
  57 static int hf_lmi_dlci_low = -1;
  58 static int hf_lmi_new = -1;
  59 static int hf_lmi_act = -1;
  60
  61 static gint ett_lmi = -1;
  62 static gint ett_lmi_ele = -1;
  63
  64 #ifdef _OLD_
  65 /*
  66  * Bits in the address field.
  67  */
  68 #define LMI_CMD         0xf000  /* LMI Command */
  69 #define LMI_SEQ         0x0fff  /* LMI Sequence number */
  70
  71 #endif
  72
  73 static const value_string msg_type_str[] = {
  74         {0x75, "Status Enquiry"},
  75         {0x7D, "Status"},
  76         { 0,       NULL }
  77         };
  78
  79 static const value_string element_type_str[] = {
  80
  81 /*** These are the ANSI values ***/
  82         {0x01, "Report"},
  83         {0x03, "Keep Alive"},
  84         {0x07, "PVC Status"},
  85
  86 /*** These are the ITU values ***/
  87         {0x51, "Report"},
  88         {0x53, "Keep Alive"},
  89         {0x07, "PVC Status"},
  90
  91         { 0,       NULL }
  92         };
  93
  94 static const value_string record_type_str[] = {
  95         {0x00, "Full Status"},
  96         {0x01, "Link Integrity Verification Only"},
  97         {0x02, "Single PVC"},
  98         { 0,       NULL }
  99         };
 100
 101 static const value_string pvc_status_new_str[] = {
 102         {0x00, "PVC already present"},
 103         {0x01, "PVC is new"},
 104         { 0,       NULL }
 105         };
 106
 107 static const value_string pvc_status_act_str[] = {
 108         {0x00, "PVC is Inactive"},
 109         {0x01, "PVC is Active"},
 110         { 0,       NULL }
 111         };
 112
 113 static void
 114 dissect_lmi_report_type(tvbuff_t *tvb, int offset, proto_tree *tree)
 115 {
 116         proto_tree_add_uint(tree, hf_lmi_rcd_type, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 117 }
 118
 119 static void
 120 dissect_lmi_link_int(tvbuff_t *tvb, int offset, proto_tree *tree)
 121 {
 122         proto_tree_add_uint(tree, hf_lmi_send_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 123         ++offset;
 124         proto_tree_add_uint(tree, hf_lmi_recv_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 125
 126 }
 127
 128 static void
 129 dissect_lmi_pvc_status(tvbuff_t *tvb, int offset, proto_tree *tree)
 130 {
 131         proto_tree_add_uint(tree, hf_lmi_dlci_high, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 132         ++offset;
 133         proto_tree_add_uint(tree, hf_lmi_dlci_low, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 134         ++offset;
 135         proto_tree_add_uint(tree, hf_lmi_new, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 136         proto_tree_add_uint(tree, hf_lmi_act, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 137 }
 138
 139 static void
 140 dissect_lmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 141 {
 142         proto_tree      *lmi_tree = NULL, *lmi_subtree;
 143         proto_item      *ti;
 144         int             offset = 2, len;
 145         guint8          msg_type;
 146         guint8          ele_id;
 147
 148         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 149                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "LMI");
 150         if (check_col(pinfo->cinfo, COL_INFO))
 151                 col_clear(pinfo->cinfo, COL_INFO);
 152
 153         if (tree) {
 154                 ti = proto_tree_add_item(tree, proto_lmi, tvb, 0, 3, FALSE);
 155                 lmi_tree = proto_item_add_subtree(ti, ett_lmi_ele);
 156
 157                 proto_tree_add_item(lmi_tree, hf_lmi_call_ref, tvb, 0, 1, FALSE);
 158         }
 159         msg_type = tvb_get_guint8( tvb, 1);
 160         if (check_col(pinfo->cinfo, COL_INFO)) {
 161                 col_add_str(pinfo->cinfo, COL_INFO,
 162                     val_to_str(msg_type, msg_type_str, "Unknown message type (0x%02x)"));
 163         }
 164         if (tree) {
 165                 proto_tree_add_uint(lmi_tree, hf_lmi_msg_type, tvb, 1, 1, msg_type);
 166
 167         /* Display the LMI elements */
 168                 while (tvb_reported_length_remaining(tvb, offset) > 0) {
 169                         ele_id = tvb_get_guint8( tvb, offset);
 170                         len =  tvb_get_guint8( tvb, offset + 1);
 171
 172                         ti = proto_tree_add_text(lmi_tree, tvb, offset, len + 2,
 173                                 "Information Element: %s",
 174                                 val_to_str(ele_id, element_type_str, "Unknown (%u)"));
 175
 176                         lmi_subtree = proto_item_add_subtree(ti, ett_lmi_ele);
 177
 178                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_ele, tvb, offset, 1,
 179                                 ele_id);
 180                         ++offset;
 181                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_len, tvb, offset, 1, len);
 182                         ++offset;
 183                         if (( ele_id == 1) || (ele_id == 51))
 184                                 dissect_lmi_report_type( tvb, offset, lmi_subtree);
 185                         else if (( ele_id == 3) || (ele_id == 53))
 186                                 dissect_lmi_link_int( tvb, offset, lmi_subtree);
 187                         else if (( ele_id == 7) || (ele_id == 57))
 188                                 dissect_lmi_pvc_status( tvb, offset, lmi_subtree);
 189                         offset += len;
 190                 }
 191         }
 192         else {
 193                 lmi_tree = NULL;
 194         }
 195 }
 196
 197
 198 void
 199 proto_register_lmi(void)
 200 {
 201     static hf_register_info hf[] = {
 202         { &hf_lmi_call_ref,
 203           { "Call reference", "lmi.cmd", FT_UINT8, BASE_HEX, NULL, 0,
 204                 "Call Reference", HFILL }},
 205
 206         { &hf_lmi_msg_type,
 207           { "Message Type", "lmi.msg_type", FT_UINT8, BASE_HEX, VALS(msg_type_str), 0,
 208                 "Message Type", HFILL }},
 209
 210         { &hf_lmi_inf_ele,
 211           { "Type", "lmi.inf_ele_type", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 212                 "Information Element Type", HFILL }},
 213         { &hf_lmi_inf_len,
 214           { "Length", "lmi.inf_ele_len", FT_UINT8, BASE_DEC, NULL, 0,
 215                 "Information Element Length", HFILL }},
 216
 217         { &hf_lmi_rcd_type,
 218           { "Record Type", "lmi.ele_rcd_type", FT_UINT8, BASE_DEC, VALS(record_type_str), 0,
 219                 "Record Type", HFILL }},
 220         { &hf_lmi_send_seq,
 221           { "Send Seq", "lmi.send_seq", FT_UINT8, BASE_DEC, NULL, 0,
 222                 "Send Sequence", HFILL }},
 223         { &hf_lmi_recv_seq,
 224           { "Recv Seq", "lmi.recv_seq", FT_UINT8, BASE_DEC, NULL, 0,
 225                 "Receive Sequence", HFILL }},
 226         { &hf_lmi_dlci_high,
 227           { "DLCI High", "lmi.dlci_hi", FT_UINT8, BASE_DEC, NULL, 0x3f,
 228                 "DLCI High bits", HFILL }},
 229         { &hf_lmi_dlci_low,
 230           { "DLCI Low", "lmi.dlci_low", FT_UINT8, BASE_DEC, NULL, 0x78,
 231                 "DLCI Low bits", HFILL }},
 232         { &hf_lmi_new,
 233           { "DLCI New", "lmi.dlci_new", FT_UINT8, BASE_DEC, VALS(pvc_status_new_str), 0x08,
 234                 "DLCI New Flag", HFILL }},
 235         { &hf_lmi_act,
 236           { "DLCI Active","lmi.dlci_act", FT_UINT8, BASE_DEC, VALS(pvc_status_act_str), 0x02,
 237                 "DLCI Active Flag", HFILL }},
 238     };
 239     static gint *ett[] = {
 240         &ett_lmi,
 241         &ett_lmi_ele,
 242     };
 243     proto_lmi = proto_register_protocol ("Local Management Interface", "LMI", "lmi");
 244     proto_register_field_array (proto_lmi, hf, array_length(hf));
 245     proto_register_subtree_array(ett, array_length(ett));
 246
 247 }
 248
 249 void
 250 proto_reg_handoff_lmi(void)
 251 {
 252         dissector_handle_t lmi_handle;
 253
 254         lmi_handle = create_dissector_handle(dissect_lmi, proto_lmi);
 255         dissector_add("fr.ietf", NLPID_LMI, lmi_handle);
 256 }