epan/dissectors/packet-mime-encap.c

   1 /* packet-mime-encap.c
   2  *
   3  * $Id$
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  */
  23
  24 #include "config.h"
  25
  26 #include <glib.h>
  27 #include <epan/packet.h>
  28
  29 #include "tvbuff-int.h"
  30
  31 static int proto_mime_encap = -1;
  32
  33 static heur_dissector_list_t heur_subdissector_list;
  34 static dissector_handle_t data_handle;
  35
  36 static tvbuff_t *file_tvbs;
  37 static tvbuff_t *whole_tvb;
  38
  39 static void
  40 mime_encap_init(void)
  41 {
  42         if (file_tvbs) {
  43                 tvb_free_chain(file_tvbs);
  44                 file_tvbs = NULL;
  45                 whole_tvb = NULL;
  46         }
  47 }
  48
  49 static void
  50 dissect_mime_encap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  51 {
  52         proto_item* item;
  53         guint len;
  54
  55         /* XXX, COL_INFO */
  56
  57         col_set_str(pinfo->cinfo, COL_PROTOCOL, "MIME_FILE");
  58         item = proto_tree_add_item(tree, proto_mime_encap, tvb, 0, -1, ENC_NA);
  59
  60         /* frames with nsec >= 1000000000 means errors :) */
  61         if (pinfo->fd->abs_ts.nsecs >= 1000000000) {
  62                 proto_item_append_text(item, " (Error)");
  63                 /* return; */ /* dissect what we have */
  64         }
  65
  66         len = tvb_length(tvb);
  67         if (!pinfo->fd->flags.visited) {
  68                 if (len) {
  69                         tvbuff_t *cloned_tvb = tvb_clone(tvb);
  70
  71                         if (!file_tvbs) {
  72                                 file_tvbs = cloned_tvb;
  73                                 whole_tvb = tvb_new_composite();
  74                         } else
  75                                 tvb_add_to_chain(file_tvbs, cloned_tvb);
  76
  77                         tvb_composite_append(whole_tvb, cloned_tvb);
  78                 } else
  79                         tvb_composite_finalize(whole_tvb);
  80         }
  81
  82         /* End of file? */
  83         if (!len && whole_tvb) {
  84                 /*
  85                  * Here we're doing some trick.
  86                  *
  87                  * We don't want to call dissectors with composite tvb, cause dissectors can create subsets or real data child
  88                  * on it, which would append to whole_tvb chain and would be freed only in mime_encap_init.
  89                  *
  90                  * So we create some tvb which pass all calls to whole_tvb, but chain with tvb (which is freed in dissection cleanup)
  91                  */
  92                 tvbuff_t *tmp_tvb = tvb_new_chain(tvb, whole_tvb);
  93
  94                 proto_item_append_text(item, " (Final)");
  95
  96                 add_new_data_source(pinfo, tmp_tvb, "Whole file");
  97
  98                 if (!dissector_try_heuristic(heur_subdissector_list, tmp_tvb, pinfo, tree, NULL)) {
  99                         proto_item_append_text(item, " (Unhandled)");
 100                         call_dissector(data_handle, tmp_tvb, pinfo, tree);
 101                 }
 102         }
 103 }
 104
 105 void
 106 proto_register_mime_encap(void)
 107 {
 108         proto_mime_encap = proto_register_protocol("MIME file", "MIME_FILE", "mime_dlt");
 109
 110         register_dissector("mime_dlt", dissect_mime_encap, proto_mime_encap);
 111         register_init_routine(mime_encap_init);
 112         register_heur_dissector_list("wtap_file", &heur_subdissector_list);
 113 }
 114
 115 void
 116 proto_reg_handoff_mime_encap(void)
 117 {
 118         dissector_handle_t mime_encap_handle;
 119
 120         data_handle = find_dissector("data");
 121         mime_encap_handle = find_dissector("mime_dlt");
 122         dissector_add_uint("wtap_encap", WTAP_ENCAP_MIME, mime_encap_handle);
 123 }