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 1.43 2004/01/03 18:40:07 sharpe 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 int proto_frame = -1;
  39 int hf_frame_arrival_time = -1;
  40 static int hf_frame_time_delta = -1;
  41 static int hf_frame_time_relative = -1;
  42 int hf_frame_number = -1;
  43 int hf_frame_packet_len = -1;
  44 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 static int hf_frame_ref_time = -1;
  49
  50 static int proto_short = -1;
  51 int proto_malformed = -1;
  52 static int proto_unreassembled = -1;
  53
  54 static gint ett_frame = -1;
  55
  56 static int frame_tap = -1;
  57
  58 static dissector_handle_t data_handle;
  59 static dissector_handle_t docsis_handle;
  60
  61 /* Preferences */
  62 static gboolean show_file_off = FALSE;
  63 static gboolean force_docsis_encap;
  64
  65 static const value_string p2p_dirs[] = {
  66         { P2P_DIR_SENT, "Sent" },
  67         { P2P_DIR_RECV, "Received" },
  68         { 0, NULL }
  69 };
  70
  71 static dissector_table_t wtap_encap_dissector_table;
  72
  73 static void
  74 dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  75 {
  76         proto_tree      *fh_tree;
  77         proto_item      *ti;
  78         nstime_t        ts;
  79         int             cap_len, pkt_len;
  80
  81         pinfo->current_proto = "Frame";
  82
  83         if (pinfo->pseudo_header != NULL) {
  84                 switch (pinfo->fd->lnk_t) {
  85
  86                 case WTAP_ENCAP_WFLEET_HDLC:
  87                 case WTAP_ENCAP_CHDLC_WITH_PHDR:
  88                 case WTAP_ENCAP_PPP_WITH_PHDR:
  89                 case WTAP_ENCAP_SDLC:
  90                         pinfo->p2p_dir = pinfo->pseudo_header->p2p.sent ?
  91                             P2P_DIR_SENT : P2P_DIR_RECV;
  92                         break;
  93
  94                 case WTAP_ENCAP_LAPB:
  95                 case WTAP_ENCAP_FRELAY_WITH_PHDR:
  96                         pinfo->p2p_dir =
  97                             (pinfo->pseudo_header->x25.flags & FROM_DCE) ?
  98                             P2P_DIR_RECV : P2P_DIR_SENT;
  99                         break;
 100
 101                 case WTAP_ENCAP_ISDN:
 102                         pinfo->p2p_dir = pinfo->pseudo_header->isdn.uton ?
 103                             P2P_DIR_SENT : P2P_DIR_RECV;
 104                         break;
 105                 }
 106         }
 107
 108         if ((force_docsis_encap) && (docsis_handle)) {
 109                 /*
 110                  * XXX - setting it here makes it impossible to
 111                  * turn the "Treat all frames as DOCSIS frames"
 112                  * option off.
 113                  *
 114                  * The TCP Graph code currently uses "fd->lnk_t";
 115                  * it should eventually just get the information
 116                  * it needs from a full-blown dissection, so that
 117                  * can handle any link-layer type.
 118                  */
 119                 pinfo->fd->lnk_t = WTAP_ENCAP_DOCSIS;
 120         }
 121
 122         /* Put in frame header information. */
 123         if (tree) {
 124
 125           cap_len = tvb_length(tvb);
 126           pkt_len = tvb_reported_length(tvb);
 127
 128           ti = proto_tree_add_protocol_format(tree, proto_frame, tvb, 0, -1,
 129             "Frame %u (%u bytes on wire, %u bytes captured)", pinfo->fd->num, pkt_len, cap_len);
 130
 131           fh_tree = proto_item_add_subtree(ti, ett_frame);
 132
 133           proto_tree_add_boolean_hidden(fh_tree, hf_frame_marked, tvb, 0, 0,pinfo->fd->flags.marked);
 134
 135           if(pinfo->fd->flags.ref_time){
 136                 proto_tree_add_item(fh_tree, hf_frame_ref_time, tvb, 0, 0, FALSE);
 137           }
 138
 139           ts.secs = pinfo->fd->abs_secs;
 140           ts.nsecs = pinfo->fd->abs_usecs*1000;
 141
 142           proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
 143                 0, 0, &ts);
 144
 145           ts.secs = pinfo->fd->del_secs;
 146           ts.nsecs = pinfo->fd->del_usecs*1000;
 147
 148           proto_tree_add_time(fh_tree, hf_frame_time_delta, tvb,
 149                 0, 0, &ts);
 150
 151           ts.secs = pinfo->fd->rel_secs;
 152           ts.nsecs = pinfo->fd->rel_usecs*1000;
 153
 154           proto_tree_add_time(fh_tree, hf_frame_time_relative, tvb,
 155                 0, 0, &ts);
 156
 157           proto_tree_add_uint(fh_tree, hf_frame_number, tvb,
 158                 0, 0, pinfo->fd->num);
 159
 160           proto_tree_add_uint_format(fh_tree, hf_frame_packet_len, tvb,
 161                 0, 0, pkt_len, "Packet Length: %d byte%s", pkt_len,
 162                 plurality(pkt_len, "", "s"));
 163
 164           proto_tree_add_uint_format(fh_tree, hf_frame_capture_len, tvb,
 165                 0, 0, cap_len, "Capture Length: %d byte%s", cap_len,
 166                 plurality(cap_len, "", "s"));
 167
 168           /* Check for existences of P2P pseudo header */
 169           if (pinfo->p2p_dir != P2P_DIR_UNKNOWN) {
 170                   proto_tree_add_uint(fh_tree, hf_frame_p2p_dir, tvb,
 171                                   0, 0, pinfo->p2p_dir);
 172           }
 173
 174           if (show_file_off) {
 175                   proto_tree_add_int_format(fh_tree, hf_frame_file_off, tvb,
 176                                   0, 0, pinfo->fd->file_off,
 177                                   "File Offset: %ld (0x%lx)",
 178                                   pinfo->fd->file_off, pinfo->fd->file_off);
 179           }
 180         }
 181
 182
 183         TRY {
 184                 if (!dissector_try_port(wtap_encap_dissector_table, pinfo->fd->lnk_t,
 185                                         tvb, pinfo, tree)) {
 186
 187                         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 188                                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
 189                         if (check_col(pinfo->cinfo, COL_INFO))
 190                                 col_add_fstr(pinfo->cinfo, COL_INFO, "WTAP_ENCAP = %u",
 191                                     pinfo->fd->lnk_t);
 192                         call_dissector(data_handle,tvb, pinfo, tree);
 193                 }
 194         }
 195         CATCH_ALL {
 196                 show_exception(tvb, pinfo, tree, EXCEPT_CODE);
 197         }
 198         ENDTRY;
 199
 200         tap_queue_packet(frame_tap, pinfo, NULL);
 201 }
 202
 203 void
 204 show_exception(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 205     unsigned long exception)
 206 {
 207         switch (exception) {
 208
 209         case BoundsError:
 210                 if (check_col(pinfo->cinfo, COL_INFO))
 211                         col_append_str(pinfo->cinfo, COL_INFO, "[Short Frame]");
 212                 proto_tree_add_protocol_format(tree, proto_short, tvb, 0, 0,
 213                                 "[Short Frame: %s]", pinfo->current_proto);
 214                 break;
 215
 216         case ReportedBoundsError:
 217                 show_reported_bounds_error(tvb, pinfo, tree);
 218                 break;
 219         }
 220 }
 221
 222 void
 223 show_reported_bounds_error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 224 {
 225         if (pinfo->fragmented) {
 226                 /*
 227                  * We were dissecting an unreassembled fragmented
 228                  * packet when the exception was thrown, so the
 229                  * problem isn't that the dissector expected
 230                  * something but it wasn't in the packet, the
 231                  * problem is that the dissector expected something
 232                  * but it wasn't in the fragment we dissected.
 233                  */
 234                 if (check_col(pinfo->cinfo, COL_INFO))
 235                         col_append_fstr(pinfo->cinfo, COL_INFO,
 236                             "[Unreassembled Packet%s]",
 237                             pinfo->noreassembly_reason);
 238                 proto_tree_add_protocol_format(tree, proto_unreassembled,
 239                     tvb, 0, 0, "[Unreassembled Packet%s: %s]",
 240                     pinfo->noreassembly_reason, pinfo->current_proto);
 241         } else {
 242                 if (check_col(pinfo->cinfo, COL_INFO))
 243                         col_append_str(pinfo->cinfo, COL_INFO,
 244                             "[Malformed Packet]");
 245                 proto_tree_add_protocol_format(tree, proto_malformed,
 246                     tvb, 0, 0, "[Malformed Packet: %s]", pinfo->current_proto);
 247         }
 248 }
 249
 250 void
 251 proto_register_frame(void)
 252 {
 253         static hf_register_info hf[] = {
 254                 { &hf_frame_arrival_time,
 255                 { "Arrival Time",               "frame.time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0,
 256                         "Absolute time when this frame was captured", HFILL }},
 257
 258                 { &hf_frame_time_delta,
 259                 { "Time delta from previous packet",    "frame.time_delta", FT_RELATIVE_TIME, BASE_NONE, NULL,
 260                         0x0,
 261                         "Time delta since previous diplayed frame", HFILL }},
 262
 263                 { &hf_frame_time_relative,
 264                 { "Time since reference or first frame",        "frame.time_relative", FT_RELATIVE_TIME, BASE_NONE, NULL,
 265                         0x0,
 266                         "Time relative reference or first frame", HFILL }},
 267
 268                 { &hf_frame_number,
 269                 { "Frame Number",               "frame.number", FT_UINT32, BASE_DEC, NULL, 0x0,
 270                         "", HFILL }},
 271
 272                 { &hf_frame_packet_len,
 273                 { "Total Frame Length",         "frame.pkt_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 274                         "", HFILL }},
 275
 276                 { &hf_frame_capture_len,
 277                 { "Capture Frame Length",       "frame.cap_len", FT_UINT32, BASE_DEC, NULL, 0x0,
 278                         "", HFILL }},
 279
 280                 { &hf_frame_p2p_dir,
 281                 { "Point-to-Point Direction",   "frame.p2p_dir", FT_UINT8, BASE_DEC, VALS(p2p_dirs), 0x0,
 282                         "", HFILL }},
 283
 284                 { &hf_frame_file_off,
 285                 { "File Offset",        "frame.file_off", FT_INT32, BASE_DEC, NULL, 0x0,
 286                         "", HFILL }},
 287
 288                 { &hf_frame_marked,
 289                 { "Frame is marked",    "frame.marked", FT_BOOLEAN, 8, NULL, 0x0,
 290                         "Frame is marked in the GUI", HFILL }},
 291
 292                 { &hf_frame_ref_time,
 293                 { "This is a Ref Time frame",   "frame.ref_time", FT_NONE, 0, NULL, 0x0,
 294                         "This frame is a Reference Time frame", HFILL }},
 295         };
 296         static gint *ett[] = {
 297                 &ett_frame,
 298         };
 299         module_t *frame_module;
 300
 301         wtap_encap_dissector_table = register_dissector_table("wtap_encap",
 302             "Wiretap encapsulation type", FT_UINT32, BASE_DEC);
 303
 304         proto_frame = proto_register_protocol("Frame", "Frame", "frame");
 305         proto_register_field_array(proto_frame, hf, array_length(hf));
 306         proto_register_subtree_array(ett, array_length(ett));
 307         register_dissector("frame",dissect_frame,proto_frame);
 308
 309         /* You can't disable dissection of "Frame", as that would be
 310            tantamount to not doing any dissection whatsoever. */
 311         proto_set_cant_toggle(proto_frame);
 312
 313         proto_short = proto_register_protocol("Short Frame", "Short frame", "short");
 314         proto_malformed = proto_register_protocol("Malformed Packet",
 315             "Malformed packet", "malformed");
 316         proto_unreassembled = proto_register_protocol(
 317             "Unreassembled Fragmented Packet",
 318             "Unreassembled fragmented packet", "unreassembled");
 319
 320         /* "Short Frame", "Malformed Packet", and "Unreassembled Fragmented
 321            Packet" aren't really protocols, they're error indications;
 322            disabling them makes no sense. */
 323         proto_set_cant_toggle(proto_short);
 324         proto_set_cant_toggle(proto_malformed);
 325         proto_set_cant_toggle(proto_unreassembled);
 326
 327         /* Our preferences */
 328         frame_module = prefs_register_protocol(proto_frame, NULL);
 329         prefs_register_bool_preference(frame_module, "show_file_off",
 330             "Show File Offset", "Show File Offset", &show_file_off);
 331         prefs_register_bool_preference(frame_module, "force_docsis_encap",
 332             "Treat all frames as DOCSIS frames", "Treat all frames as DOCSIS Frames", &force_docsis_encap);
 333
 334         frame_tap=register_tap("frame");
 335 }
 336
 337 void
 338 proto_reg_handoff_frame(void)
 339 {
 340         data_handle = find_dissector("data");
 341         docsis_handle = find_dissector("docsis");
 342 }