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 1.32 2002/10/31 07:12:23 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_CHDLC:
  86                 case WTAP_ENCAP_PPP_WITH_PHDR:
  87                         pinfo->p2p_dir = pinfo->pseudo_header->p2p.sent ?
  88                             P2P_DIR_SENT : P2P_DIR_RECV;
  89                         break;
  90
  91                 case WTAP_ENCAP_LAPB:
  92                 case WTAP_ENCAP_FRELAY:
  93                         pinfo->p2p_dir =
  94                             (pinfo->pseudo_header->x25.flags & FROM_DCE) ?
  95                             P2P_DIR_RECV : P2P_DIR_SENT;
  96                         break;
  97
  98                 case WTAP_ENCAP_ISDN:
  99                         pinfo->p2p_dir = pinfo->pseudo_header->isdn.uton ?
 100                             P2P_DIR_SENT : P2P_DIR_RECV;
 101                         break;
 102                 }
 103         }
 104
 105         if ((force_docsis_encap) && (docsis_handle)) {
 106                 /*
 107                  * XXX - setting it here makes it impossible to
 108                  * turn the "Treat all frames as DOCSIS frames"
 109                  * option off.
 110                  *
 111                  * The TCP Graph code currently uses "fd->lnk_t";
 112                  * it should eventually just get the information
 113                  * it needs from a full-blown dissection, so that
 114                  * can handle any link-layer type.
 115                  */
 116                 pinfo->fd->lnk_t = WTAP_ENCAP_DOCSIS;
 117         }
 118
 119         /* Put in frame header information. */
 120         if (tree) {
 121
 122           cap_len = tvb_length(tvb);
 123           pkt_len = tvb_reported_length(tvb);
 124
 125           ti = proto_tree_add_protocol_format(tree, proto_frame, tvb, 0, -1,
 126             "Frame %u (%u bytes on wire, %u bytes captured)", pinfo->fd->num, pkt_len, cap_len);
 127
 128           fh_tree = proto_item_add_subtree(ti, ett_frame);
 129
 130           proto_tree_add_boolean_hidden(fh_tree, hf_frame_marked, tvb, 0, 0,pinfo->fd->flags.marked);
 131
 132           ts.secs = pinfo->fd->abs_secs;
 133           ts.nsecs = pinfo->fd->abs_usecs*1000;
 134
 135           proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
 136                 0, 0, &ts);
 137
 138           ts.secs = pinfo->fd->del_secs;
 139           ts.nsecs = pinfo->fd->del_usecs*1000;
 140
 141           proto_tree_add_time(fh_tree, hf_frame_time_delta, tvb,
 142                 0, 0, &ts);
 143
 144           ts.secs = pinfo->fd->rel_secs;
 145           ts.nsecs = pinfo->fd->rel_usecs*1000;
 146
 147           proto_tree_add_time(fh_tree, hf_frame_time_relative, tvb,
 148                 0, 0, &ts);
 149
 150           proto_tree_add_uint(fh_tree, hf_frame_number, tvb,
 151                 0, 0, pinfo->fd->num);
 152
 153           proto_tree_add_uint_format(fh_tree, hf_frame_packet_len, tvb,
 154                 0, 0, pkt_len, "Packet Length: %d byte%s", pkt_len,
 155                 plurality(pkt_len, "", "s"));
 156
 157           proto_tree_add_uint_format(fh_tree, hf_frame_capture_len, tvb,
 158                 0, 0, cap_len, "Capture Length: %d byte%s", cap_len,
 159                 plurality(cap_len, "", "s"));
 160
 161           /* Check for existences of P2P pseudo header */
 162           if (pinfo->p2p_dir != P2P_DIR_UNKNOWN) {
 163                   proto_tree_add_uint(fh_tree, hf_frame_p2p_dir, tvb,
 164                                   0, 0, pinfo->p2p_dir);
 165           }
 166
 167           if (show_file_off) {
 168                   proto_tree_add_int_format(fh_tree, hf_frame_file_off, tvb,
 169                                   0, 0, pinfo->fd->file_off,
 170                                   "File Offset: %ld (0x%lx)",
 171                                   pinfo->fd->file_off, pinfo->fd->file_off);
 172           }
 173         }
 174
 175
 176         TRY {
 177                 if (!dissector_try_port(wtap_encap_dissector_table, pinfo->fd->lnk_t,
 178                                         tvb, pinfo, tree)) {
 179
 180                         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 181                                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
 182                         if (check_col(pinfo->cinfo, COL_INFO))
 183                                 col_add_fstr(pinfo->cinfo, COL_INFO, "WTAP_ENCAP = %u",
 184                                     pinfo->fd->lnk_t);
 185                         call_dissector(data_handle,tvb, pinfo, tree);
 186                 }
 187         }
 188         CATCH(BoundsError) {
 189                 if (check_col(pinfo->cinfo, COL_INFO))
 190                         col_append_str(pinfo->cinfo, COL_INFO, "[Short Frame]");
 191                 proto_tree_add_protocol_format(tree, proto_short, tvb, 0, 0,
 192                                 "[Short Frame: %s]", pinfo->current_proto);
 193         }
 194         CATCH(ReportedBoundsError) {
 195                 show_reported_bounds_error(tvb, pinfo, tree);
 196         }
 197         ENDTRY;
 198
 199         tap_queue_packet(frame_tap, pinfo, NULL);
 200 }
 201
 202 void
 203 show_reported_bounds_error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 204 {
 205         if (pinfo->fragmented) {
 206                 /*
 207                  * We were dissecting an unreassembled fragmented
 208                  * packet when the exception was thrown, so the
 209                  * problem isn't that the dissector expected
 210                  * something but it wasn't in the packet, the
 211                  * problem is that the dissector expected something
 212                  * but it wasn't in the fragment we dissected.
 213                  */
 214                 if (check_col(pinfo->cinfo, COL_INFO))
 215                         col_append_str(pinfo->cinfo, COL_INFO,
 216                             "[Unreassembled Packet]");
 217                 proto_tree_add_protocol_format(tree, proto_unreassembled,
 218                     tvb, 0, 0, "[Unreassembled Packet: %s]",
 219                     pinfo->current_proto);
 220         } else {
 221                 if (check_col(pinfo->cinfo, COL_INFO))
 222                         col_append_str(pinfo->cinfo, COL_INFO,
 223                             "[Malformed Packet]");
 224                 proto_tree_add_protocol_format(tree, proto_malformed,
 225                     tvb, 0, 0, "[Malformed Packet: %s]", pinfo->current_proto);
 226         }
 227 }
 228
 229 void
 230 proto_register_frame(void)
 231 {
 232         static hf_register_info hf[] = {
 233                 { &hf_frame_arrival_time,
 234                 { "Arrival Time",               "frame.time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0,
 235                         "", HFILL }},
 236
 237                 { &hf_frame_time_delta,
 238                 { "Time delta from previous packet",    "frame.time_delta", FT_RELATIVE_TIME, BASE_NONE, NULL,
 239                         0x0,
 240                         "", HFILL }},
 241
 242                 { &hf_frame_time_relative,
 243                 { "Time relative to first packet",      "frame.time_relative", FT_RELATIVE_TIME, BASE_NONE, NULL,
 244                         0x0,
 245                         "", HFILL }},
 246
 247                 { &hf_frame_number,
 248                 { "Frame Number",               "frame.number", FT_UINT32, BASE_DEC, NULL, 0x0,
 249                         "", HFILL }},
 250
 251                 { &hf_frame_packet_len,
 252                 { "Total Frame Length",         "frame.pkt_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 253                         "", HFILL }},
 254
 255                 { &hf_frame_capture_len,
 256                 { "Capture Frame Length",       "frame.cap_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 257                         "", HFILL }},
 258
 259                 { &hf_frame_p2p_dir,
 260                 { "Point-to-Point Direction",   "frame.p2p_dir", FT_UINT8, BASE_DEC, VALS(p2p_dirs), 0x0,
 261                         "", HFILL }},
 262
 263                 { &hf_frame_file_off,
 264                 { "File Offset",        "frame.file_off", FT_INT32, BASE_DEC, NULL, 0x0,
 265                         "", HFILL }},
 266
 267                 { &hf_frame_marked,
 268                 { "Frame is marked",    "frame.marked", FT_BOOLEAN, 8, NULL, 0x0,
 269                         "Frame is marked in the GUI", HFILL }},
 270         };
 271         static gint *ett[] = {
 272                 &ett_frame,
 273         };
 274         module_t *frame_module;
 275
 276         wtap_encap_dissector_table = register_dissector_table("wtap_encap",
 277             "Wiretap encapsulation type", FT_UINT32, BASE_DEC);
 278
 279         proto_frame = proto_register_protocol("Frame", "Frame", "frame");
 280         proto_register_field_array(proto_frame, hf, array_length(hf));
 281         proto_register_subtree_array(ett, array_length(ett));
 282         register_dissector("frame",dissect_frame,proto_frame);
 283
 284         /* You can't disable dissection of "Frame", as that would be
 285            tantamount to not doing any dissection whatsoever. */
 286         proto_set_cant_disable(proto_frame);
 287
 288         proto_short = proto_register_protocol("Short Frame", "Short frame", "short");
 289         proto_malformed = proto_register_protocol("Malformed Packet",
 290             "Malformed packet", "malformed");
 291         proto_unreassembled = proto_register_protocol(
 292             "Unreassembled Fragmented Packet",
 293             "Unreassembled fragmented packet", "unreassembled");
 294
 295         /* "Short Frame", "Malformed Packet", and "Unreassembled Fragmented
 296            Packet" aren't really protocols, they're error indications;
 297            disabling them makes no sense. */
 298         proto_set_cant_disable(proto_short);
 299         proto_set_cant_disable(proto_malformed);
 300         proto_set_cant_disable(proto_unreassembled);
 301
 302         /* Our preferences */
 303         frame_module = prefs_register_protocol(proto_frame, NULL);
 304         prefs_register_bool_preference(frame_module, "show_file_off",
 305             "Show File Offset", "Show File Offset", &show_file_off);
 306         prefs_register_bool_preference(frame_module, "force_docsis_encap",
 307             "Treat all frames as DOCSIS frames", "Treat all frames as DOCSIS Frames", &force_docsis_encap);
 308
 309         frame_tap=register_tap("frame");
 310 }
 311
 312 void
 313 proto_reg_handoff_frame(void)
 314 {
 315         data_handle = find_dissector("data");
 316         docsis_handle = find_dissector("docsis");
 317 }