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 1.36 2003/03/03 23:29:57 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 2000 Gerald Combs
  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
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32 #include <epan/timestamp.h>
  33 #include <epan/tvbuff.h>
  34 #include "packet-frame.h"
  35 #include "prefs.h"
  36 #include "tap.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 hf_frame_marked = -1;
  48
  49 static int proto_short = -1;
  50 int proto_malformed = -1;
  51 static int proto_unreassembled = -1;
  52
  53 static gint ett_frame = -1;
  54
  55 static int frame_tap = -1;
  56
  57 static dissector_handle_t data_handle;
  58 static dissector_handle_t docsis_handle;
  59
  60 /* Preferences */
  61 static gboolean show_file_off = FALSE;
  62 static gboolean force_docsis_encap;
  63
  64 static const value_string p2p_dirs[] = {
  65         { P2P_DIR_SENT, "Sent" },
  66         { P2P_DIR_RECV, "Received" },
  67         { 0, NULL }
  68 };
  69
  70 static dissector_table_t wtap_encap_dissector_table;
  71
  72 static void
  73 dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  74 {
  75         proto_tree      *fh_tree;
  76         proto_item      *ti;
  77         nstime_t        ts;
  78         int             cap_len, pkt_len;
  79
  80         pinfo->current_proto = "Frame";
  81
  82         if (pinfo->pseudo_header != NULL) {
  83                 switch (pinfo->fd->lnk_t) {
  84
  85                 case WTAP_ENCAP_WFLEET_HDLC:
  86                 case WTAP_ENCAP_CHDLC:
  87                 case WTAP_ENCAP_PPP_WITH_PHDR:
  88                 case WTAP_ENCAP_SDLC:
  89                         pinfo->p2p_dir = pinfo->pseudo_header->p2p.sent ?
  90                             P2P_DIR_SENT : P2P_DIR_RECV;
  91                         break;
  92
  93                 case WTAP_ENCAP_LAPB:
  94                 case WTAP_ENCAP_FRELAY_WITH_PHDR:
  95                         pinfo->p2p_dir =
  96                             (pinfo->pseudo_header->x25.flags & FROM_DCE) ?
  97                             P2P_DIR_RECV : P2P_DIR_SENT;
  98                         break;
  99
 100                 case WTAP_ENCAP_ISDN:
 101                         pinfo->p2p_dir = pinfo->pseudo_header->isdn.uton ?
 102                             P2P_DIR_SENT : P2P_DIR_RECV;
 103                         break;
 104                 }
 105         }
 106
 107         if ((force_docsis_encap) && (docsis_handle)) {
 108                 /*
 109                  * XXX - setting it here makes it impossible to
 110                  * turn the "Treat all frames as DOCSIS frames"
 111                  * option off.
 112                  *
 113                  * The TCP Graph code currently uses "fd->lnk_t";
 114                  * it should eventually just get the information
 115                  * it needs from a full-blown dissection, so that
 116                  * can handle any link-layer type.
 117                  */
 118                 pinfo->fd->lnk_t = WTAP_ENCAP_DOCSIS;
 119         }
 120
 121         /* Put in frame header information. */
 122         if (tree) {
 123
 124           cap_len = tvb_length(tvb);
 125           pkt_len = tvb_reported_length(tvb);
 126
 127           ti = proto_tree_add_protocol_format(tree, proto_frame, tvb, 0, -1,
 128             "Frame %u (%u bytes on wire, %u bytes captured)", pinfo->fd->num, pkt_len, cap_len);
 129
 130           fh_tree = proto_item_add_subtree(ti, ett_frame);
 131
 132           proto_tree_add_boolean_hidden(fh_tree, hf_frame_marked, tvb, 0, 0,pinfo->fd->flags.marked);
 133
 134           ts.secs = pinfo->fd->abs_secs;
 135           ts.nsecs = pinfo->fd->abs_usecs*1000;
 136
 137           proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
 138                 0, 0, &ts);
 139
 140           ts.secs = pinfo->fd->del_secs;
 141           ts.nsecs = pinfo->fd->del_usecs*1000;
 142
 143           proto_tree_add_time(fh_tree, hf_frame_time_delta, tvb,
 144                 0, 0, &ts);
 145
 146           ts.secs = pinfo->fd->rel_secs;
 147           ts.nsecs = pinfo->fd->rel_usecs*1000;
 148
 149           proto_tree_add_time(fh_tree, hf_frame_time_relative, tvb,
 150                 0, 0, &ts);
 151
 152           proto_tree_add_uint(fh_tree, hf_frame_number, tvb,
 153                 0, 0, pinfo->fd->num);
 154
 155           proto_tree_add_uint_format(fh_tree, hf_frame_packet_len, tvb,
 156                 0, 0, pkt_len, "Packet Length: %d byte%s", pkt_len,
 157                 plurality(pkt_len, "", "s"));
 158
 159           proto_tree_add_uint_format(fh_tree, hf_frame_capture_len, tvb,
 160                 0, 0, cap_len, "Capture Length: %d byte%s", cap_len,
 161                 plurality(cap_len, "", "s"));
 162
 163           /* Check for existences of P2P pseudo header */
 164           if (pinfo->p2p_dir != P2P_DIR_UNKNOWN) {
 165                   proto_tree_add_uint(fh_tree, hf_frame_p2p_dir, tvb,
 166                                   0, 0, pinfo->p2p_dir);
 167           }
 168
 169           if (show_file_off) {
 170                   proto_tree_add_int_format(fh_tree, hf_frame_file_off, tvb,
 171                                   0, 0, pinfo->fd->file_off,
 172                                   "File Offset: %ld (0x%lx)",
 173                                   pinfo->fd->file_off, pinfo->fd->file_off);
 174           }
 175         }
 176
 177
 178         TRY {
 179                 if (!dissector_try_port(wtap_encap_dissector_table, pinfo->fd->lnk_t,
 180                                         tvb, pinfo, tree)) {
 181
 182                         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 183                                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
 184                         if (check_col(pinfo->cinfo, COL_INFO))
 185                                 col_add_fstr(pinfo->cinfo, COL_INFO, "WTAP_ENCAP = %u",
 186                                     pinfo->fd->lnk_t);
 187                         call_dissector(data_handle,tvb, pinfo, tree);
 188                 }
 189         }
 190         CATCH(BoundsError) {
 191                 if (check_col(pinfo->cinfo, COL_INFO))
 192                         col_append_str(pinfo->cinfo, COL_INFO, "[Short Frame]");
 193                 proto_tree_add_protocol_format(tree, proto_short, tvb, 0, 0,
 194                                 "[Short Frame: %s]", pinfo->current_proto);
 195         }
 196         CATCH(ReportedBoundsError) {
 197                 show_reported_bounds_error(tvb, pinfo, tree);
 198         }
 199         ENDTRY;
 200
 201         tap_queue_packet(frame_tap, pinfo, NULL);
 202 }
 203
 204 void
 205 show_reported_bounds_error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 206 {
 207         if (pinfo->fragmented) {
 208                 /*
 209                  * We were dissecting an unreassembled fragmented
 210                  * packet when the exception was thrown, so the
 211                  * problem isn't that the dissector expected
 212                  * something but it wasn't in the packet, the
 213                  * problem is that the dissector expected something
 214                  * but it wasn't in the fragment we dissected.
 215                  */
 216                 if (check_col(pinfo->cinfo, COL_INFO))
 217                         col_append_fstr(pinfo->cinfo, COL_INFO,
 218                             "[Unreassembled Packet%s]",
 219                             pinfo->noreassembly_reason);
 220                 proto_tree_add_protocol_format(tree, proto_unreassembled,
 221                     tvb, 0, 0, "[Unreassembled Packet%s: %s]",
 222                     pinfo->noreassembly_reason, pinfo->current_proto);
 223         } else {
 224                 if (check_col(pinfo->cinfo, COL_INFO))
 225                         col_append_str(pinfo->cinfo, COL_INFO,
 226                             "[Malformed Packet]");
 227                 proto_tree_add_protocol_format(tree, proto_malformed,
 228                     tvb, 0, 0, "[Malformed Packet: %s]", pinfo->current_proto);
 229         }
 230 }
 231
 232 void
 233 proto_register_frame(void)
 234 {
 235         static hf_register_info hf[] = {
 236                 { &hf_frame_arrival_time,
 237                 { "Arrival Time",               "frame.time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0,
 238                         "", HFILL }},
 239
 240                 { &hf_frame_time_delta,
 241                 { "Time delta from previous packet",    "frame.time_delta", FT_RELATIVE_TIME, BASE_NONE, NULL,
 242                         0x0,
 243                         "", HFILL }},
 244
 245                 { &hf_frame_time_relative,
 246                 { "Time relative to first packet",      "frame.time_relative", FT_RELATIVE_TIME, BASE_NONE, NULL,
 247                         0x0,
 248                         "", HFILL }},
 249
 250                 { &hf_frame_number,
 251                 { "Frame Number",               "frame.number", FT_UINT32, BASE_DEC, NULL, 0x0,
 252                         "", HFILL }},
 253
 254                 { &hf_frame_packet_len,
 255                 { "Total Frame Length",         "frame.pkt_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 256                         "", HFILL }},
 257
 258                 { &hf_frame_capture_len,
 259                 { "Capture Frame Length",       "frame.cap_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 260                         "", HFILL }},
 261
 262                 { &hf_frame_p2p_dir,
 263                 { "Point-to-Point Direction",   "frame.p2p_dir", FT_UINT8, BASE_DEC, VALS(p2p_dirs), 0x0,
 264                         "", HFILL }},
 265
 266                 { &hf_frame_file_off,
 267                 { "File Offset",        "frame.file_off", FT_INT32, BASE_DEC, NULL, 0x0,
 268                         "", HFILL }},
 269
 270                 { &hf_frame_marked,
 271                 { "Frame is marked",    "frame.marked", FT_BOOLEAN, 8, NULL, 0x0,
 272                         "Frame is marked in the GUI", HFILL }},
 273         };
 274         static gint *ett[] = {
 275                 &ett_frame,
 276         };
 277         module_t *frame_module;
 278
 279         wtap_encap_dissector_table = register_dissector_table("wtap_encap",
 280             "Wiretap encapsulation type", FT_UINT32, BASE_DEC);
 281
 282         proto_frame = proto_register_protocol("Frame", "Frame", "frame");
 283         proto_register_field_array(proto_frame, hf, array_length(hf));
 284         proto_register_subtree_array(ett, array_length(ett));
 285         register_dissector("frame",dissect_frame,proto_frame);
 286
 287         /* You can't disable dissection of "Frame", as that would be
 288            tantamount to not doing any dissection whatsoever. */
 289         proto_set_cant_disable(proto_frame);
 290
 291         proto_short = proto_register_protocol("Short Frame", "Short frame", "short");
 292         proto_malformed = proto_register_protocol("Malformed Packet",
 293             "Malformed packet", "malformed");
 294         proto_unreassembled = proto_register_protocol(
 295             "Unreassembled Fragmented Packet",
 296             "Unreassembled fragmented packet", "unreassembled");
 297
 298         /* "Short Frame", "Malformed Packet", and "Unreassembled Fragmented
 299            Packet" aren't really protocols, they're error indications;
 300            disabling them makes no sense. */
 301         proto_set_cant_disable(proto_short);
 302         proto_set_cant_disable(proto_malformed);
 303         proto_set_cant_disable(proto_unreassembled);
 304
 305         /* Our preferences */
 306         frame_module = prefs_register_protocol(proto_frame, NULL);
 307         prefs_register_bool_preference(frame_module, "show_file_off",
 308             "Show File Offset", "Show File Offset", &show_file_off);
 309         prefs_register_bool_preference(frame_module, "force_docsis_encap",
 310             "Treat all frames as DOCSIS frames", "Treat all frames as DOCSIS Frames", &force_docsis_encap);
 311
 312         frame_tap=register_tap("frame");
 313 }
 314
 315 void
 316 proto_reg_handoff_frame(void)
 317 {
 318         data_handle = find_dissector("data");
 319         docsis_handle = find_dissector("docsis");
 320 }