packet-frame.c

   1 /* packet-frame.c
   2  *
   3  * Top-most dissector. Decides dissector based on Wiretap Encapsulation Type.
   4  *
   5  * $Id: packet-frame.c,v 1.10 2001/11/01 04:00:56 gram Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@zing.org>
   9  * Copyright 2000 Gerald Combs
  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
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <glib.h>
  32 #include "packet.h"
  33 #include "timestamp.h"
  34 #include "tvbuff.h"
  35 #include "packet-frame.h"
  36 #include "prefs.h"
  37
  38 static int proto_frame = -1;
  39 static int hf_frame_arrival_time = -1;
  40 static int hf_frame_time_delta = -1;
  41 static int hf_frame_time_relative = -1;
  42 static int hf_frame_number = -1;
  43 static int hf_frame_packet_len = -1;
  44 static int hf_frame_capture_len = -1;
  45 static int hf_frame_p2p_dir = -1;
  46 static int hf_frame_file_off = -1;
  47 static int proto_short = -1;
  48 int proto_malformed = -1;
  49
  50 static gint ett_frame = -1;
  51
  52 /* Preferences */
  53 static gboolean show_file_off = FALSE;
  54
  55 static const value_string p2p_dirs[] = {
  56         { P2P_DIR_SENT, "Sent" },
  57         { P2P_DIR_RECV, "Received" },
  58         { 0, NULL }
  59 };
  60
  61 static dissector_table_t wtap_encap_dissector_table;
  62
  63 void
  64 dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  65 {
  66         proto_tree      *fh_tree;
  67         proto_item      *ti;
  68         nstime_t        ts;
  69         int             cap_len, pkt_len;
  70
  71         pinfo->current_proto = "Frame";
  72
  73         if (pinfo->fd->lnk_t == WTAP_ENCAP_LAPD ||
  74                         pinfo->fd->lnk_t == WTAP_ENCAP_PPP_WITH_PHDR) {
  75
  76                 pinfo->p2p_dir = pinfo->pseudo_header->p2p.sent ? P2P_DIR_SENT : P2P_DIR_RECV;
  77         }
  78
  79         /* Put in frame header information. */
  80         if (tree) {
  81
  82           cap_len = tvb_length(tvb);
  83           pkt_len = tvb_reported_length(tvb);
  84
  85           ti = proto_tree_add_protocol_format(tree, proto_frame, tvb, 0, tvb_length(tvb),
  86             "Frame %u (%u on wire, %u captured)", pinfo->fd->num, pkt_len, cap_len);
  87
  88           fh_tree = proto_item_add_subtree(ti, ett_frame);
  89
  90           ts.secs = pinfo->fd->abs_secs;
  91           ts.nsecs = pinfo->fd->abs_usecs*1000;
  92
  93           proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
  94                 0, 0, &ts);
  95
  96           ts.secs = pinfo->fd->del_secs;
  97           ts.nsecs = pinfo->fd->del_usecs*1000;
  98
  99           proto_tree_add_time(fh_tree, hf_frame_time_delta, tvb,
 100                 0, 0, &ts);
 101
 102           ts.secs = pinfo->fd->rel_secs;
 103           ts.nsecs = pinfo->fd->rel_usecs*1000;
 104
 105           proto_tree_add_time(fh_tree, hf_frame_time_relative, tvb,
 106                 0, 0, &ts);
 107
 108           proto_tree_add_uint(fh_tree, hf_frame_number, tvb,
 109                 0, 0, pinfo->fd->num);
 110
 111           proto_tree_add_uint_format(fh_tree, hf_frame_packet_len, tvb,
 112                 0, 0, pkt_len, "Packet Length: %d byte%s", pkt_len,
 113                 plurality(pkt_len, "", "s"));
 114
 115           proto_tree_add_uint_format(fh_tree, hf_frame_capture_len, tvb,
 116                 0, 0, cap_len, "Capture Length: %d byte%s", cap_len,
 117                 plurality(cap_len, "", "s"));
 118
 119           /* Check for existences of P2P pseudo header */
 120           if (pinfo->p2p_dir != P2P_DIR_UNKNOWN) {
 121                   proto_tree_add_uint(fh_tree, hf_frame_p2p_dir, tvb,
 122                                   0, 0, pinfo->p2p_dir);
 123           }
 124
 125       if (show_file_off) {
 126         proto_tree_add_int_format(fh_tree, hf_frame_file_off, tvb,
 127             0, 0, pinfo->fd->file_off, "File Offset: %ld (0x%lx)",
 128             pinfo->fd->file_off, pinfo->fd->file_off);
 129       }
 130         }
 131
 132
 133         TRY {
 134                 if (!dissector_try_port(wtap_encap_dissector_table, pinfo->fd->lnk_t,
 135                                         tvb, pinfo, tree)) {
 136
 137                         if (check_col(pinfo->fd, COL_PROTOCOL))
 138                                 col_set_str(pinfo->fd, COL_PROTOCOL, "UNKNOWN");
 139                         if (check_col(pinfo->fd, COL_INFO))
 140                                 col_add_fstr(pinfo->fd, COL_INFO, "WTAP_ENCAP = 0x%x", pinfo->fd->lnk_t);
 141                         dissect_data(tvb, 0, pinfo, tree);
 142                 }
 143         }
 144         CATCH(BoundsError) {
 145                 if (check_col(pinfo->fd, COL_INFO))
 146                         col_append_str(pinfo->fd, COL_INFO, "[Short Frame]");
 147                 proto_tree_add_protocol_format(tree, proto_short, tvb, 0, 0,
 148                                 "[Short Frame: %s]", pinfo->current_proto );
 149         }
 150         CATCH(ReportedBoundsError) {
 151                 if (check_col(pinfo->fd, COL_INFO))
 152                         col_append_str(pinfo->fd, COL_INFO, "[Malformed Frame]");
 153                 proto_tree_add_protocol_format(tree, proto_malformed, tvb, 0, 0,
 154                                 "[Malformed Frame: %s]", pinfo->current_proto );
 155         }
 156         ENDTRY;
 157 }
 158
 159 void
 160 proto_register_frame(void)
 161 {
 162         static hf_register_info hf[] = {
 163                 { &hf_frame_arrival_time,
 164                 { "Arrival Time",               "frame.time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0,
 165                         "", HFILL }},
 166
 167                 { &hf_frame_time_delta,
 168                 { "Time delta from previous packet",    "frame.time_delta", FT_RELATIVE_TIME, BASE_NONE, NULL,
 169                         0x0,
 170                         "", HFILL }},
 171
 172                 { &hf_frame_time_relative,
 173                 { "Time relative to first packet",      "frame.time_relative", FT_RELATIVE_TIME, BASE_NONE, NULL,
 174                         0x0,
 175                         "", HFILL }},
 176
 177                 { &hf_frame_number,
 178                 { "Frame Number",               "frame.number", FT_UINT32, BASE_DEC, NULL, 0x0,
 179                         "", HFILL }},
 180
 181                 { &hf_frame_packet_len,
 182                 { "Total Frame Length",         "frame.pkt_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 183                         "", HFILL }},
 184
 185                 { &hf_frame_capture_len,
 186                 { "Capture Frame Length",       "frame.cap_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 187                         "", HFILL }},
 188
 189                 { &hf_frame_p2p_dir,
 190                 { "Point-to-Point Direction",   "frame.p2p_dir", FT_UINT8, BASE_DEC, VALS(p2p_dirs), 0x0,
 191                         "", HFILL }},
 192
 193                 { &hf_frame_file_off,
 194                 { "File Offset",        "frame.file_off", FT_INT32, BASE_DEC, NULL, 0x0,
 195                         "", HFILL }},
 196
 197         };
 198         static gint *ett[] = {
 199                 &ett_frame,
 200         };
 201     module_t *frame_module;
 202
 203         wtap_encap_dissector_table = register_dissector_table("wtap_encap");
 204
 205         proto_frame = proto_register_protocol("Frame", "Frame", "frame");
 206         proto_register_field_array(proto_frame, hf, array_length(hf));
 207         proto_register_subtree_array(ett, array_length(ett));
 208         register_dissector("frame",dissect_frame,proto_frame);
 209
 210         /* You can't disable dissection of "Frame", as that would be
 211            tantamount to not doing any dissection whatsoever. */
 212         proto_set_cant_disable(proto_frame);
 213
 214         proto_short = proto_register_protocol("Short Frame", "Short frame", "short");
 215         proto_malformed = proto_register_protocol("Malformed Frame",
 216             "Malformed frame", "malformed");
 217
 218         /* "Short Frame" and "Malformed Frame" aren't really protocols,
 219            they're error indications; disabling them makes no sense. */
 220         proto_set_cant_disable(proto_short);
 221         proto_set_cant_disable(proto_malformed);
 222
 223     /* Our preferences */
 224     frame_module = prefs_register_protocol(proto_frame, NULL);
 225     prefs_register_bool_preference(frame_module, "show_file_off",
 226         "Show File Offset", "Show File Offset", &show_file_off);
 227 }