epan/dissectors/packet-v5ef.c

   1 /* packet-v5ef.c
   2  * Routines for V5 envelope function frame disassembly
   3  * Rolf Fiedler <rolf.fiedler@innoventif.de>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25 /*
  26  * V5 bitstream over HDLC handling
  27  *
  28  * V5 references:
  29  *
  30  * ETS 300 324-1
  31  * ETS 300 347-1
  32  */
  33
  34 #include "config.h"
  35
  36 #include <glib.h>
  37
  38 #include <epan/packet.h>
  39 #include <epan/conversation.h>
  40 #include <epan/xdlc.h>
  41 #include <epan/crc16-tvb.h>
  42
  43 static int proto_v5ef = -1;
  44 static int hf_v5ef_direction = -1;
  45 static int hf_v5ef_address = -1;
  46 static int hf_v5ef_eah = -1;
  47 static int hf_v5ef_ea1 = -1;
  48 static int hf_v5ef_eal = -1;
  49 static int hf_v5ef_ea2 = -1;
  50
  51 static gint ett_v5ef = -1;
  52 static gint ett_v5ef_address = -1;
  53
  54 static dissector_handle_t v5dl_handle, lapd_handle;
  55
  56 /*
  57  * Bits in the address field.
  58  */
  59 #define V5EF_EAH                0xfc00  /* Service Access Point Identifier */
  60 #define V5EF_EAH_SHIFT          10
  61 #define V5EF_EA1                0x0100  /* First Address Extension bit */
  62 #define V5EF_EAL                0x00fe  /* Terminal Endpoint Identifier */
  63 #define V5EF_EAL_SHIFT          1
  64 #define V5EF_EA2                0x0001  /* Second Address Extension bit */
  65
  66 static const value_string v5ef_direction_vals[] = {
  67         { 0,            "AN->LE"},
  68         { 1,            "LE->AN"},
  69         { 0,            NULL }
  70 };
  71
  72 #define MAX_V5EF_PACKET_LEN 1024
  73
  74 static void
  75 dissect_v5ef(tvbuff_t*, packet_info*, proto_tree*);
  76
  77 static void
  78 dissect_v5ef(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  79 {
  80         proto_tree      *v5ef_tree, *addr_tree;
  81         proto_item      *v5ef_ti, *addr_ti;
  82         int              direction;
  83         int              v5ef_header_len;
  84         guint16          addr, eah, eal, efaddr;
  85         tvbuff_t        *next_tvb;
  86         const char      *srcname = "src";
  87         const char      *dstname = "dst";
  88
  89         col_set_str(pinfo->cinfo, COL_PROTOCOL, "V5-EF");
  90         col_clear(pinfo->cinfo, COL_INFO);
  91
  92         addr            = tvb_get_ntohs(tvb, 0);
  93         eah             = (addr & V5EF_EAH) >> V5EF_EAH_SHIFT;
  94         eal             = (addr & V5EF_EAL) >> V5EF_EAL_SHIFT;
  95         efaddr          = (eah << 7) + eal;
  96         v5ef_header_len = 2;    /* addr */
  97
  98         direction = pinfo->pseudo_header->isdn.uton;
  99         if (direction==0) {
 100                 srcname = "LE";
 101                 dstname = "AN";
 102          } else if (direction > 0) {
 103                 srcname = "AN";
 104                 dstname = "LE";
 105         }
 106         col_set_str(pinfo->cinfo, COL_RES_DL_SRC, srcname);
 107         col_set_str(pinfo->cinfo, COL_RES_DL_DST, dstname);
 108
 109         if (tree) {
 110                 proto_item *direction_ti;
 111
 112                 v5ef_ti = proto_tree_add_item(tree, proto_v5ef, tvb, 0, -1,
 113                     ENC_NA);
 114                 v5ef_tree = proto_item_add_subtree(v5ef_ti, ett_v5ef);
 115
 116                 /*
 117                  * Don't show the direction if we don't know it.
 118                  */
 119                 if (direction != P2P_DIR_UNKNOWN) {
 120                         direction_ti = proto_tree_add_uint(v5ef_tree, hf_v5ef_direction,
 121                                                            tvb, 0, 0, direction);
 122                         PROTO_ITEM_SET_GENERATED(direction_ti);
 123                 }
 124
 125                 addr_ti = proto_tree_add_uint(v5ef_tree, hf_v5ef_address, tvb,
 126                     0, 2, addr);
 127                 addr_tree = proto_item_add_subtree(addr_ti, ett_v5ef_address);
 128
 129                 proto_tree_add_uint(addr_tree, hf_v5ef_eah,  tvb, 0, 1, addr);
 130                 proto_tree_add_uint(addr_tree, hf_v5ef_ea1, tvb, 0, 1, addr);
 131                 proto_tree_add_uint(addr_tree, hf_v5ef_eal, tvb, 1, 1, addr);
 132                 proto_tree_add_uint(addr_tree, hf_v5ef_ea2, tvb, 1, 1, addr);
 133         }
 134         else {
 135                 v5ef_ti   = NULL;
 136                 v5ef_tree = NULL;
 137         }
 138
 139         if (tree)
 140                 proto_item_set_len(v5ef_ti, v5ef_header_len);
 141
 142         next_tvb = tvb_new_subset_remaining(tvb, v5ef_header_len);
 143
 144         if (efaddr>8175)
 145                 call_dissector(v5dl_handle,next_tvb, pinfo, tree);
 146         else
 147                 call_dissector(lapd_handle,next_tvb, pinfo, tree);
 148 }
 149
 150 void
 151 proto_reg_handoff_v5ef(void);
 152
 153 void
 154 proto_register_v5ef(void)
 155 {
 156         static hf_register_info hf[] = {
 157
 158         { &hf_v5ef_direction,
 159           { "Direction", "v5ef.direction", FT_UINT8, BASE_DEC, VALS(v5ef_direction_vals), 0x0,
 160                 NULL, HFILL }},
 161
 162         { &hf_v5ef_address,
 163           { "Address Field", "v5ef.address", FT_UINT16, BASE_HEX, NULL, 0x0,
 164                 "Address", HFILL }},
 165
 166         { &hf_v5ef_eah,
 167           { "EAH", "v5ef.eah", FT_UINT16, BASE_DEC, NULL, V5EF_EAH,
 168                 "Envelope Address High Part", HFILL }},
 169
 170         { &hf_v5ef_ea1,
 171           { "EA1", "v5ef.ea1", FT_UINT16, BASE_DEC, NULL, V5EF_EA1,
 172                 "First Address Extension bit", HFILL }},
 173
 174         { &hf_v5ef_eal,
 175           { "EAL", "v5ef.eal", FT_UINT16, BASE_DEC, NULL, V5EF_EAL,
 176                 "Envelope Address Low Part", HFILL }},
 177
 178         { &hf_v5ef_ea2,
 179           { "EA2", "v5ef.ea2", FT_UINT16, BASE_DEC, NULL, V5EF_EA2,
 180                 "Second Address Extension bit", HFILL }},
 181         };
 182
 183         static gint *ett[] = {
 184                 &ett_v5ef,
 185                 &ett_v5ef_address,
 186         };
 187
 188         proto_v5ef = proto_register_protocol("V5 Envelope Function (v5ef)",
 189                                          "v5ef", "v5ef");
 190         proto_register_field_array (proto_v5ef, hf, array_length(hf));
 191         proto_register_subtree_array(ett, array_length(ett));
 192
 193         register_dissector("v5ef", dissect_v5ef, proto_v5ef);
 194
 195 }
 196
 197 void
 198 proto_reg_handoff_v5ef(void)
 199 {
 200         dissector_handle_t v5ef_handle;
 201
 202         v5ef_handle = find_dissector("v5ef");
 203         dissector_add_uint("wtap_encap", WTAP_ENCAP_V5_EF, v5ef_handle);
 204
 205         lapd_handle = find_dissector("lapd");
 206         v5dl_handle = find_dissector("v5dl");
 207 }