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 1.1 2001/03/23 19:22:02 jfoster Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@zing.org>
   9  * Copyright 1998
  10  *
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  *
  26  * ToDo:
  27  *
  28  * References:
  29  *
  30  * http://www.techfest.com/networking/wan/frrel.htm
  31  * http://www.frforum.com/5000/frf1_2.pdf
  32  * http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm#xtocid125314
  33  * http://www.net.aapt.com.au/techref/lmimess.htm
  34  * http://www.raleigh.ibm.com:80/cgi-bin/bookmgr/BOOKS/EZ305800/1.2.4.4
  35  */
  36
  37
  38 #ifdef HAVE_CONFIG_H
  39 # include "config.h"
  40 #endif
  41
  42 #ifdef HAVE_SYS_TYPES_H
  43 # include <sys/types.h>
  44 #endif
  45
  46 #include <stdio.h>
  47 #include <glib.h>
  48 #include <string.h>
  49 #include "packet.h"
  50 #include "packet-osi.h"
  51
  52
  53 static int proto_lmi = -1;
  54 static int hf_lmi_call_ref = -1;
  55 static int hf_lmi_msg_type = -1;
  56 static int hf_lmi_inf_ele = -1;
  57 static int hf_lmi_inf_len = -1;
  58
  59 static int hf_lmi_rcd_type = -1;
  60 static int hf_lmi_send_seq = -1;
  61 static int hf_lmi_recv_seq = -1;
  62 static int hf_lmi_dlci_high = -1;
  63 static int hf_lmi_dlci_low = -1;
  64 static int hf_lmi_new = -1;
  65 static int hf_lmi_act = -1;
  66
  67 static gint ett_lmi = -1;
  68 static gint ett_lmi_ele = -1;
  69
  70 #define NLPID_LMI 0x09          /* NLPID value for LMI */
  71
  72 #ifdef _OLD_
  73 /*
  74  * Bits in the address field.
  75  */
  76 #define LMI_CMD         0xf000  /* LMI Command */
  77 #define LMI_SEQ         0x0fff  /* LMI Sequence number */
  78
  79 #endif
  80
  81 static const value_string msg_type_str[] = {
  82         {0x75, "Status Enquiry"},
  83         {0x7D, "Status"},
  84         { 0,       NULL }
  85         };
  86
  87 static const value_string element_type_str[] = {
  88
  89 /*** These are the ANSI values ***/
  90         {0x01, "Report"},
  91         {0x03, "Keep Alive"},
  92         {0x07, "PVC Status"},
  93
  94 /*** These are the ITU values ***/
  95         {0x51, "Report"},
  96         {0x53, "Keep Alive"},
  97         {0x07, "PVC Status"},
  98
  99         { 0,       NULL }
 100         };
 101
 102 static const value_string record_type_str[] = {
 103         {0x00, "Full Status"},
 104         {0x01, "Link Integrity Verification Only"},
 105         {0x02, "Single PVC"},
 106         { 0,       NULL }
 107         };
 108
 109 static const value_string pvc_status_new_str[] = {
 110         {0x00, "PVC already present"},
 111         {0x01, "PVC is new"},
 112         { 0,       NULL }
 113         };
 114
 115 static const value_string pvc_status_act_str[] = {
 116         {0x00, "PVC is Inactive"},
 117         {0x01, "PVC is Acive"},
 118         { 0,       NULL }
 119         };
 120
 121 static void
 122 dissect_lmi_report_type(tvbuff_t *tvb, int offset, proto_tree *tree)
 123 {
 124         proto_tree_add_uint(tree, hf_lmi_rcd_type, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 125 }
 126
 127 static void
 128 dissect_lmi_link_int(tvbuff_t *tvb, int offset, proto_tree *tree)
 129 {
 130         proto_tree_add_uint(tree, hf_lmi_send_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 131         ++offset;
 132         proto_tree_add_uint(tree, hf_lmi_recv_seq, tvb, offset, 0, tvb_get_guint8( tvb, offset));
 133
 134 }
 135
 136 static void
 137 dissect_lmi_pvc_status(tvbuff_t *tvb, int offset, proto_tree *tree)
 138 {
 139         proto_tree_add_uint(tree, hf_lmi_dlci_high, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 140         ++offset;
 141         proto_tree_add_uint(tree, hf_lmi_dlci_low, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 142         ++offset;
 143         proto_tree_add_uint(tree, hf_lmi_new, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 144         proto_tree_add_uint(tree, hf_lmi_act, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 145 }
 146
 147 static void
 148 dissect_lmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 149 {
 150         proto_tree      *lmi_tree, *lmi_subtree;
 151         proto_item      *ti;
 152         int             offset = 2, len;
 153         guint8          ele_id;
 154
 155         if (check_col(pinfo->fd, COL_PROTOCOL))
 156                 col_set_str(pinfo->fd, COL_PROTOCOL, "LMI");
 157
 158         if (tree) {
 159                 ti = proto_tree_add_item(tree, proto_lmi, tvb, 0, 3, FALSE);
 160                 lmi_tree = proto_item_add_subtree(ti, ett_lmi_ele);
 161
 162                 proto_tree_add_uint(lmi_tree, hf_lmi_call_ref, tvb, 0, 1, tvb_get_guint8( tvb, 0));
 163                 proto_tree_add_uint(lmi_tree, hf_lmi_msg_type,  tvb, 1, 1,  tvb_get_guint8( tvb, 1));
 164
 165         /* Display the LMI elements */
 166                 while( offset < tvb_length( tvb)){
 167                         ele_id = tvb_get_guint8( tvb, offset);
 168                         len =  tvb_get_guint8( tvb, offset + 1);
 169
 170                         ti = proto_tree_add_uint(lmi_tree, hf_lmi_inf_ele, tvb, offset, len + 2,
 171                                 tvb_get_guint8( tvb, offset));
 172
 173                         lmi_subtree = proto_item_add_subtree(ti, ett_lmi_ele);
 174
 175                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_ele, tvb, offset, 1,
 176                                 tvb_get_guint8( tvb, offset));
 177                         ++offset;
 178                         len =  tvb_get_guint8( tvb, offset);
 179                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_len, tvb, offset, 1, len);
 180                         ++offset;
 181                         if (( ele_id == 1) || (ele_id == 51))
 182                                 dissect_lmi_report_type( tvb, offset, lmi_subtree);
 183                         else if (( ele_id == 3) || (ele_id == 53))
 184                                 dissect_lmi_link_int( tvb, offset, lmi_subtree);
 185                         else if (( ele_id == 7) || (ele_id == 57))
 186                                 dissect_lmi_pvc_status( tvb, offset, lmi_subtree);
 187                         offset += len;
 188                 }
 189         }
 190         else {
 191                 lmi_tree = NULL;
 192         }
 193 }
 194
 195
 196 void
 197 proto_register_lmi(void)
 198 {
 199     static hf_register_info hf[] = {
 200         { &hf_lmi_call_ref,
 201           { "Call reference", "lmi.cmd", FT_UINT8, BASE_HEX, NULL, 0,
 202                 "Call Reference" }},
 203
 204         { &hf_lmi_msg_type,
 205           { "Message Type", "lmi.msg_type", FT_UINT8, BASE_HEX, VALS(msg_type_str), 0,
 206                 "Message Type" }},
 207
 208         { &hf_lmi_inf_ele,
 209           { "Information Element", "lmi.inf_ele", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 210                 "Information Element" }},
 211         { &hf_lmi_inf_ele,
 212           { "Type", "lmi.inf_ele_type", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 213                 "Information Element Type" }},
 214         { &hf_lmi_inf_len,
 215           { "Length", "lmi.inf_ele_len", FT_UINT8, BASE_DEC, NULL, 0,
 216                 "Information Element Length" }},
 217
 218         { &hf_lmi_rcd_type,
 219           { "Record Type", "lmi.ele_rcd_type", FT_UINT8, BASE_DEC, VALS(record_type_str), 0,
 220                 "Record Type" }},
 221         { &hf_lmi_send_seq,
 222           { "Send Seq", "lmi.send_seq", FT_UINT8, BASE_DEC, NULL, 0,
 223                 "Send Sequence" }},
 224         { &hf_lmi_recv_seq,
 225           { "Recv Seq", "lmi.recv_seq", FT_UINT8, BASE_DEC, NULL, 0,
 226                 "Receive Sequence" }},
 227         { &hf_lmi_dlci_high,
 228           { "DLCI High", "lmi.dlci_hi", FT_UINT8, BASE_DEC, NULL, 0x3f,
 229                 "DLCI High bits" }},
 230         { &hf_lmi_dlci_low,
 231           { "DLCI Low", "lmi.dlci_low", FT_UINT8, BASE_DEC, NULL, 0x78,
 232                 "DLCI Low bits" }},
 233         { &hf_lmi_new,
 234           { "DLCI New", "lmi.dlci_new", FT_UINT8, BASE_DEC, VALS(pvc_status_new_str), 0x08,
 235                 "DLCI New Flag" }},
 236         { &hf_lmi_act,
 237           { "DLCI Active","lmi.dlci_act", FT_UINT8, BASE_DEC, VALS(pvc_status_act_str), 0x02,
 238                 "DLCI Active Flag" }},
 239     };
 240     static gint *ett[] = {
 241         &ett_lmi,
 242         &ett_lmi_ele,
 243     };
 244     proto_lmi = proto_register_protocol ("Local Management Interface", "LMI", "lmi");
 245     proto_register_field_array (proto_lmi, hf, array_length(hf));
 246     proto_register_subtree_array(ett, array_length(ett));
 247
 248 }
 249
 250 void
 251 proto_reg_handoff_lmi(void)
 252 {
 253         dissector_add("fr.ietf", NLPID_LMI, dissect_lmi, proto_lmi);
 254 }