epan/dissectors/packet-ieee802a.c

   1 /* packet-ieee802a.c
   2  * Routines for IEEE 802a
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24
  25 #include "config.h"
  26
  27 #include <glib.h>
  28 #include <epan/packet.h>
  29 #include <epan/addr_resolv.h>
  30 #include <epan/strutil.h>
  31 #include <epan/etypes.h>
  32
  33 #include "packet-ieee802a.h"
  34
  35 static int proto_ieee802a = -1;
  36 static int hf_ieee802a_oui = -1;
  37 static int hf_ieee802a_pid = -1;
  38
  39 static gint ett_ieee802a = -1;
  40
  41 static dissector_handle_t data_handle;
  42
  43 /*
  44  * Hash table for translating OUIs to a dissector table/field info pair;
  45  * the dissector table maps PID values to dissectors, and the field
  46  * corresponds to the PID for that OUI.
  47  */
  48 typedef struct {
  49         dissector_table_t table;
  50         hf_register_info *field_info;
  51 } oui_info_t;
  52
  53 static GHashTable *oui_info_table = NULL;
  54
  55 /*
  56  * Add an entry for a new OUI.
  57  */
  58 void
  59 ieee802a_add_oui(guint32 oui, const char *table_name, const char *table_ui_name,
  60     hf_register_info *hf_item)
  61 {
  62         oui_info_t *new_info;
  63
  64         new_info = (oui_info_t *)g_malloc(sizeof (oui_info_t));
  65         new_info->table = register_dissector_table(table_name,
  66             table_ui_name, FT_UINT16, BASE_HEX);
  67         new_info->field_info = hf_item;
  68
  69         /*
  70          * Create the hash table for OUI information, if it doesn't
  71          * already exist.
  72          */
  73         if (oui_info_table == NULL) {
  74                 oui_info_table = g_hash_table_new(g_direct_hash,
  75                     g_direct_equal);
  76         }
  77         g_hash_table_insert(oui_info_table, GUINT_TO_POINTER(oui), new_info);
  78 }
  79
  80 static void
  81 dissect_ieee802a(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  82 {
  83         proto_tree      *ieee802a_tree = NULL;
  84         proto_item      *ti;
  85         tvbuff_t        *next_tvb;
  86         const gchar     *manuf;
  87         guint8          oui[3];
  88         guint32         oui32;
  89         guint16         pid;
  90         oui_info_t      *oui_info;
  91         dissector_table_t subdissector_table;
  92         int             hf;
  93
  94         col_set_str(pinfo->cinfo, COL_PROTOCOL, "IEEE802a");
  95         col_clear(pinfo->cinfo, COL_INFO);
  96
  97         if (tree) {
  98                 ti = proto_tree_add_item(tree, proto_ieee802a, tvb, 0, 5, ENC_NA);
  99                 ieee802a_tree = proto_item_add_subtree(ti, ett_ieee802a);
 100         }
 101
 102         tvb_memcpy(tvb, oui, 0, 3);
 103         oui32 = oui[0] << 16 | oui[1] << 8 | oui[2];
 104         manuf = get_manuf_name_if_known(oui);
 105         pid = tvb_get_ntohs(tvb, 3);
 106
 107         col_add_fstr(pinfo->cinfo, COL_INFO, "OUI %s (%s), PID 0x%04X",
 108             bytes_to_str_punct(oui, 3, ':'),
 109             manuf ? manuf : "Unknown", pid);
 110
 111         proto_tree_add_uint_format_value(ieee802a_tree, hf_ieee802a_oui,
 112             tvb, 0, 3, oui32, "%s (%s)",
 113             bytes_to_str_punct(oui, 3, ':'), manuf ? manuf : "Unknown");
 114
 115         /*
 116          * Do we have information for this OUI?
 117          */
 118         if (oui_info_table != NULL &&
 119             (oui_info = (oui_info_t *)g_hash_table_lookup(oui_info_table,
 120               GUINT_TO_POINTER(oui32))) != NULL) {
 121                 /*
 122                  * Yes - use it.
 123                  */
 124                 hf = *oui_info->field_info->p_id;
 125                 subdissector_table = oui_info->table;
 126         } else {
 127                 /*
 128                  * No, use hf_ieee802a_pid for the PID and just dissect
 129                  * the payload as data.
 130                  */
 131                 hf = hf_ieee802a_pid;
 132                 subdissector_table = NULL;
 133         }
 134         if (tree)
 135                 proto_tree_add_uint(ieee802a_tree, hf, tvb, 3, 2, pid);
 136         next_tvb = tvb_new_subset_remaining(tvb, 5);
 137         if (subdissector_table != NULL) {
 138                 /* do lookup with the subdissector table */
 139                 if (dissector_try_uint(subdissector_table, pid, next_tvb,
 140                     pinfo, tree))
 141                         return;
 142         }
 143         call_dissector(data_handle, next_tvb, pinfo, tree);
 144 }
 145
 146 void
 147 proto_register_ieee802a(void)
 148 {
 149         static hf_register_info hf[] = {
 150                 { &hf_ieee802a_oui,
 151                 { "Organization Code",  "ieee802a.oui", FT_UINT24, BASE_HEX,
 152                         NULL, 0x0, NULL, HFILL }},
 153
 154                 { &hf_ieee802a_pid,
 155                 { "Protocol ID", "ieee802a.pid", FT_UINT16, BASE_HEX,
 156                         NULL, 0x0, NULL, HFILL }}
 157         };
 158         static gint *ett[] = {
 159                 &ett_ieee802a,
 160         };
 161
 162         proto_ieee802a = proto_register_protocol("IEEE802a OUI Extended Ethertype", "IEEE802a", "ieee802a");
 163         proto_register_field_array(proto_ieee802a, hf, array_length(hf));
 164         proto_register_subtree_array(ett, array_length(ett));
 165 }
 166
 167 static void
 168 register_hf(gpointer key _U_, gpointer value, gpointer user_data _U_)
 169 {
 170         oui_info_t *info = (oui_info_t *)value;
 171
 172         proto_register_field_array(proto_ieee802a, info->field_info, 1);
 173 }
 174
 175 void
 176 proto_reg_handoff_ieee802a(void)
 177 {
 178         dissector_handle_t ieee802a_handle;
 179
 180         data_handle = find_dissector("data");
 181
 182         ieee802a_handle = create_dissector_handle(dissect_ieee802a,
 183             proto_ieee802a);
 184         dissector_add_uint("ethertype", ETHERTYPE_IEEE802_OUI_EXTENDED,
 185             ieee802a_handle);
 186
 187         /*
 188          * Register all the fields for PIDs for various OUIs.
 189          */
 190         if (oui_info_table != NULL)
 191                 g_hash_table_foreach(oui_info_table, register_hf, NULL);
 192 }