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 1.5 2001/06/18 02:17:48 guy 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 "nlpid.h"
  51
  52 static int proto_lmi = -1;
  53 static int hf_lmi_call_ref = -1;
  54 static int hf_lmi_msg_type = -1;
  55 static int hf_lmi_inf_ele = -1;
  56 static int hf_lmi_inf_len = -1;
  57
  58 static int hf_lmi_rcd_type = -1;
  59 static int hf_lmi_send_seq = -1;
  60 static int hf_lmi_recv_seq = -1;
  61 static int hf_lmi_dlci_high = -1;
  62 static int hf_lmi_dlci_low = -1;
  63 static int hf_lmi_new = -1;
  64 static int hf_lmi_act = -1;
  65
  66 static gint ett_lmi = -1;
  67 static gint ett_lmi_ele = -1;
  68
  69 #ifdef _OLD_
  70 /*
  71  * Bits in the address field.
  72  */
  73 #define LMI_CMD         0xf000  /* LMI Command */
  74 #define LMI_SEQ         0x0fff  /* LMI Sequence number */
  75
  76 #endif
  77
  78 static const value_string msg_type_str[] = {
  79         {0x75, "Status Enquiry"},
  80         {0x7D, "Status"},
  81         { 0,       NULL }
  82         };
  83
  84 static const value_string element_type_str[] = {
  85
  86 /*** These are the ANSI values ***/
  87         {0x01, "Report"},
  88         {0x03, "Keep Alive"},
  89         {0x07, "PVC Status"},
  90
  91 /*** These are the ITU values ***/
  92         {0x51, "Report"},
  93         {0x53, "Keep Alive"},
  94         {0x07, "PVC Status"},
  95
  96         { 0,       NULL }
  97         };
  98
  99 static const value_string record_type_str[] = {
 100         {0x00, "Full Status"},
 101         {0x01, "Link Integrity Verification Only"},
 102         {0x02, "Single PVC"},
 103         { 0,       NULL }
 104         };
 105
 106 static const value_string pvc_status_new_str[] = {
 107         {0x00, "PVC already present"},
 108         {0x01, "PVC is new"},
 109         { 0,       NULL }
 110         };
 111
 112 static const value_string pvc_status_act_str[] = {
 113         {0x00, "PVC is Inactive"},
 114         {0x01, "PVC is Active"},
 115         { 0,       NULL }
 116         };
 117
 118 static void
 119 dissect_lmi_report_type(tvbuff_t *tvb, int offset, proto_tree *tree)
 120 {
 121         proto_tree_add_uint(tree, hf_lmi_rcd_type, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 122 }
 123
 124 static void
 125 dissect_lmi_link_int(tvbuff_t *tvb, int offset, proto_tree *tree)
 126 {
 127         proto_tree_add_uint(tree, hf_lmi_send_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 128         ++offset;
 129         proto_tree_add_uint(tree, hf_lmi_recv_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 130
 131 }
 132
 133 static void
 134 dissect_lmi_pvc_status(tvbuff_t *tvb, int offset, proto_tree *tree)
 135 {
 136         proto_tree_add_uint(tree, hf_lmi_dlci_high, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 137         ++offset;
 138         proto_tree_add_uint(tree, hf_lmi_dlci_low, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 139         ++offset;
 140         proto_tree_add_uint(tree, hf_lmi_new, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 141         proto_tree_add_uint(tree, hf_lmi_act, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 142 }
 143
 144 static void
 145 dissect_lmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 146 {
 147         proto_tree      *lmi_tree, *lmi_subtree;
 148         proto_item      *ti;
 149         int             offset = 2, len;
 150         guint8          ele_id;
 151
 152         if (check_col(pinfo->fd, COL_PROTOCOL))
 153                 col_set_str(pinfo->fd, COL_PROTOCOL, "LMI");
 154
 155         if (tree) {
 156                 ti = proto_tree_add_item(tree, proto_lmi, tvb, 0, 3, FALSE);
 157                 lmi_tree = proto_item_add_subtree(ti, ett_lmi_ele);
 158
 159                 proto_tree_add_uint(lmi_tree, hf_lmi_call_ref, tvb, 0, 1, tvb_get_guint8( tvb, 0));
 160                 proto_tree_add_uint(lmi_tree, hf_lmi_msg_type,  tvb, 1, 1,  tvb_get_guint8( tvb, 1));
 161
 162         /* Display the LMI elements */
 163                 while( offset < tvb_length( tvb)){
 164                         ele_id = tvb_get_guint8( tvb, offset);
 165                         len =  tvb_get_guint8( tvb, offset + 1);
 166
 167                         ti = proto_tree_add_uint(lmi_tree, hf_lmi_inf_ele, tvb, offset, len + 2,
 168                                 tvb_get_guint8( tvb, offset));
 169
 170                         lmi_subtree = proto_item_add_subtree(ti, ett_lmi_ele);
 171
 172                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_ele, tvb, offset, 1,
 173                                 tvb_get_guint8( tvb, offset));
 174                         ++offset;
 175                         len =  tvb_get_guint8( tvb, offset);
 176                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_len, tvb, offset, 1, len);
 177                         ++offset;
 178                         if (( ele_id == 1) || (ele_id == 51))
 179                                 dissect_lmi_report_type( tvb, offset, lmi_subtree);
 180                         else if (( ele_id == 3) || (ele_id == 53))
 181                                 dissect_lmi_link_int( tvb, offset, lmi_subtree);
 182                         else if (( ele_id == 7) || (ele_id == 57))
 183                                 dissect_lmi_pvc_status( tvb, offset, lmi_subtree);
 184                         offset += len;
 185                 }
 186         }
 187         else {
 188                 lmi_tree = NULL;
 189         }
 190 }
 191
 192
 193 void
 194 proto_register_lmi(void)
 195 {
 196     static hf_register_info hf[] = {
 197         { &hf_lmi_call_ref,
 198           { "Call reference", "lmi.cmd", FT_UINT8, BASE_HEX, NULL, 0,
 199                 "Call Reference", HFILL }},
 200
 201         { &hf_lmi_msg_type,
 202           { "Message Type", "lmi.msg_type", FT_UINT8, BASE_HEX, VALS(msg_type_str), 0,
 203                 "Message Type", HFILL }},
 204
 205         { &hf_lmi_inf_ele,
 206           { "Information Element", "lmi.inf_ele", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 207                 "Information Element", HFILL }},
 208         { &hf_lmi_inf_ele,
 209           { "Type", "lmi.inf_ele_type", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 210                 "Information Element Type", HFILL }},
 211         { &hf_lmi_inf_len,
 212           { "Length", "lmi.inf_ele_len", FT_UINT8, BASE_DEC, NULL, 0,
 213                 "Information Element Length", HFILL }},
 214
 215         { &hf_lmi_rcd_type,
 216           { "Record Type", "lmi.ele_rcd_type", FT_UINT8, BASE_DEC, VALS(record_type_str), 0,
 217                 "Record Type", HFILL }},
 218         { &hf_lmi_send_seq,
 219           { "Send Seq", "lmi.send_seq", FT_UINT8, BASE_DEC, NULL, 0,
 220                 "Send Sequence", HFILL }},
 221         { &hf_lmi_recv_seq,
 222           { "Recv Seq", "lmi.recv_seq", FT_UINT8, BASE_DEC, NULL, 0,
 223                 "Receive Sequence", HFILL }},
 224         { &hf_lmi_dlci_high,
 225           { "DLCI High", "lmi.dlci_hi", FT_UINT8, BASE_DEC, NULL, 0x3f,
 226                 "DLCI High bits", HFILL }},
 227         { &hf_lmi_dlci_low,
 228           { "DLCI Low", "lmi.dlci_low", FT_UINT8, BASE_DEC, NULL, 0x78,
 229                 "DLCI Low bits", HFILL }},
 230         { &hf_lmi_new,
 231           { "DLCI New", "lmi.dlci_new", FT_UINT8, BASE_DEC, VALS(pvc_status_new_str), 0x08,
 232                 "DLCI New Flag", HFILL }},
 233         { &hf_lmi_act,
 234           { "DLCI Active","lmi.dlci_act", FT_UINT8, BASE_DEC, VALS(pvc_status_act_str), 0x02,
 235                 "DLCI Active Flag", HFILL }},
 236     };
 237     static gint *ett[] = {
 238         &ett_lmi,
 239         &ett_lmi_ele,
 240     };
 241     proto_lmi = proto_register_protocol ("Local Management Interface", "LMI", "lmi");
 242     proto_register_field_array (proto_lmi, hf, array_length(hf));
 243     proto_register_subtree_array(ett, array_length(ett));
 244
 245 }
 246
 247 void
 248 proto_reg_handoff_lmi(void)
 249 {
 250         dissector_add("fr.ietf", NLPID_LMI, dissect_lmi, proto_lmi);
 251 }