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 1.6 2001/09/14 07:10:05 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/frf1_2.pdf
  31  * http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm#xtocid125314
  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 #ifdef HAVE_SYS_TYPES_H
  42 # include <sys/types.h>
  43 #endif
  44
  45 #include <stdio.h>
  46 #include <glib.h>
  47 #include <string.h>
  48 #include "packet.h"
  49 #include "nlpid.h"
  50
  51 static int proto_lmi = -1;
  52 static int hf_lmi_call_ref = -1;
  53 static int hf_lmi_msg_type = -1;
  54 static int hf_lmi_inf_ele = -1;
  55 static int hf_lmi_inf_len = -1;
  56
  57 static int hf_lmi_rcd_type = -1;
  58 static int hf_lmi_send_seq = -1;
  59 static int hf_lmi_recv_seq = -1;
  60 static int hf_lmi_dlci_high = -1;
  61 static int hf_lmi_dlci_low = -1;
  62 static int hf_lmi_new = -1;
  63 static int hf_lmi_act = -1;
  64
  65 static gint ett_lmi = -1;
  66 static gint ett_lmi_ele = -1;
  67
  68 #ifdef _OLD_
  69 /*
  70  * Bits in the address field.
  71  */
  72 #define LMI_CMD         0xf000  /* LMI Command */
  73 #define LMI_SEQ         0x0fff  /* LMI Sequence number */
  74
  75 #endif
  76
  77 static const value_string msg_type_str[] = {
  78         {0x75, "Status Enquiry"},
  79         {0x7D, "Status"},
  80         { 0,       NULL }
  81         };
  82
  83 static const value_string element_type_str[] = {
  84
  85 /*** These are the ANSI values ***/
  86         {0x01, "Report"},
  87         {0x03, "Keep Alive"},
  88         {0x07, "PVC Status"},
  89
  90 /*** These are the ITU values ***/
  91         {0x51, "Report"},
  92         {0x53, "Keep Alive"},
  93         {0x07, "PVC Status"},
  94
  95         { 0,       NULL }
  96         };
  97
  98 static const value_string record_type_str[] = {
  99         {0x00, "Full Status"},
 100         {0x01, "Link Integrity Verification Only"},
 101         {0x02, "Single PVC"},
 102         { 0,       NULL }
 103         };
 104
 105 static const value_string pvc_status_new_str[] = {
 106         {0x00, "PVC already present"},
 107         {0x01, "PVC is new"},
 108         { 0,       NULL }
 109         };
 110
 111 static const value_string pvc_status_act_str[] = {
 112         {0x00, "PVC is Inactive"},
 113         {0x01, "PVC is Active"},
 114         { 0,       NULL }
 115         };
 116
 117 static void
 118 dissect_lmi_report_type(tvbuff_t *tvb, int offset, proto_tree *tree)
 119 {
 120         proto_tree_add_uint(tree, hf_lmi_rcd_type, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 121 }
 122
 123 static void
 124 dissect_lmi_link_int(tvbuff_t *tvb, int offset, proto_tree *tree)
 125 {
 126         proto_tree_add_uint(tree, hf_lmi_send_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 127         ++offset;
 128         proto_tree_add_uint(tree, hf_lmi_recv_seq, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 129
 130 }
 131
 132 static void
 133 dissect_lmi_pvc_status(tvbuff_t *tvb, int offset, proto_tree *tree)
 134 {
 135         proto_tree_add_uint(tree, hf_lmi_dlci_high, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 136         ++offset;
 137         proto_tree_add_uint(tree, hf_lmi_dlci_low, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 138         ++offset;
 139         proto_tree_add_uint(tree, hf_lmi_new, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 140         proto_tree_add_uint(tree, hf_lmi_act, tvb, offset, 1, tvb_get_guint8( tvb, offset));
 141 }
 142
 143 static void
 144 dissect_lmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 145 {
 146         proto_tree      *lmi_tree, *lmi_subtree;
 147         proto_item      *ti;
 148         int             offset = 2, len;
 149         guint8          ele_id;
 150
 151         if (check_col(pinfo->fd, COL_PROTOCOL))
 152                 col_set_str(pinfo->fd, COL_PROTOCOL, "LMI");
 153
 154         if (tree) {
 155                 ti = proto_tree_add_item(tree, proto_lmi, tvb, 0, 3, FALSE);
 156                 lmi_tree = proto_item_add_subtree(ti, ett_lmi_ele);
 157
 158                 proto_tree_add_uint(lmi_tree, hf_lmi_call_ref, tvb, 0, 1, tvb_get_guint8( tvb, 0));
 159                 proto_tree_add_uint(lmi_tree, hf_lmi_msg_type,  tvb, 1, 1,  tvb_get_guint8( tvb, 1));
 160
 161         /* Display the LMI elements */
 162                 while (tvb_reported_length_remaining(tvb, offset) > 0) {
 163                         ele_id = tvb_get_guint8( tvb, offset);
 164                         len =  tvb_get_guint8( tvb, offset + 1);
 165
 166                         ti = proto_tree_add_uint(lmi_tree, hf_lmi_inf_ele, tvb, offset, len + 2,
 167                                 tvb_get_guint8( tvb, offset));
 168
 169                         lmi_subtree = proto_item_add_subtree(ti, ett_lmi_ele);
 170
 171                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_ele, tvb, offset, 1,
 172                                 tvb_get_guint8( tvb, offset));
 173                         ++offset;
 174                         len =  tvb_get_guint8( tvb, offset);
 175                         proto_tree_add_uint(lmi_subtree, hf_lmi_inf_len, tvb, offset, 1, len);
 176                         ++offset;
 177                         if (( ele_id == 1) || (ele_id == 51))
 178                                 dissect_lmi_report_type( tvb, offset, lmi_subtree);
 179                         else if (( ele_id == 3) || (ele_id == 53))
 180                                 dissect_lmi_link_int( tvb, offset, lmi_subtree);
 181                         else if (( ele_id == 7) || (ele_id == 57))
 182                                 dissect_lmi_pvc_status( tvb, offset, lmi_subtree);
 183                         offset += len;
 184                 }
 185         }
 186         else {
 187                 lmi_tree = NULL;
 188         }
 189 }
 190
 191
 192 void
 193 proto_register_lmi(void)
 194 {
 195     static hf_register_info hf[] = {
 196         { &hf_lmi_call_ref,
 197           { "Call reference", "lmi.cmd", FT_UINT8, BASE_HEX, NULL, 0,
 198                 "Call Reference", HFILL }},
 199
 200         { &hf_lmi_msg_type,
 201           { "Message Type", "lmi.msg_type", FT_UINT8, BASE_HEX, VALS(msg_type_str), 0,
 202                 "Message Type", HFILL }},
 203
 204         { &hf_lmi_inf_ele,
 205           { "Information Element", "lmi.inf_ele", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 206                 "Information Element", HFILL }},
 207         { &hf_lmi_inf_ele,
 208           { "Type", "lmi.inf_ele_type", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
 209                 "Information Element Type", HFILL }},
 210         { &hf_lmi_inf_len,
 211           { "Length", "lmi.inf_ele_len", FT_UINT8, BASE_DEC, NULL, 0,
 212                 "Information Element Length", HFILL }},
 213
 214         { &hf_lmi_rcd_type,
 215           { "Record Type", "lmi.ele_rcd_type", FT_UINT8, BASE_DEC, VALS(record_type_str), 0,
 216                 "Record Type", HFILL }},
 217         { &hf_lmi_send_seq,
 218           { "Send Seq", "lmi.send_seq", FT_UINT8, BASE_DEC, NULL, 0,
 219                 "Send Sequence", HFILL }},
 220         { &hf_lmi_recv_seq,
 221           { "Recv Seq", "lmi.recv_seq", FT_UINT8, BASE_DEC, NULL, 0,
 222                 "Receive Sequence", HFILL }},
 223         { &hf_lmi_dlci_high,
 224           { "DLCI High", "lmi.dlci_hi", FT_UINT8, BASE_DEC, NULL, 0x3f,
 225                 "DLCI High bits", HFILL }},
 226         { &hf_lmi_dlci_low,
 227           { "DLCI Low", "lmi.dlci_low", FT_UINT8, BASE_DEC, NULL, 0x78,
 228                 "DLCI Low bits", HFILL }},
 229         { &hf_lmi_new,
 230           { "DLCI New", "lmi.dlci_new", FT_UINT8, BASE_DEC, VALS(pvc_status_new_str), 0x08,
 231                 "DLCI New Flag", HFILL }},
 232         { &hf_lmi_act,
 233           { "DLCI Active","lmi.dlci_act", FT_UINT8, BASE_DEC, VALS(pvc_status_act_str), 0x02,
 234                 "DLCI Active Flag", HFILL }},
 235     };
 236     static gint *ett[] = {
 237         &ett_lmi,
 238         &ett_lmi_ele,
 239     };
 240     proto_lmi = proto_register_protocol ("Local Management Interface", "LMI", "lmi");
 241     proto_register_field_array (proto_lmi, hf, array_length(hf));
 242     proto_register_subtree_array(ett, array_length(ett));
 243
 244 }
 245
 246 void
 247 proto_reg_handoff_lmi(void)
 248 {
 249         dissector_add("fr.ietf", NLPID_LMI, dissect_lmi, proto_lmi);
 250 }