epan/dissectors/packet-snaeth.c

   1 /* packet-snaeth.c
   2  * Routines for SNA-over-Ethernet (Ethernet type 80d5)
   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/etypes.h>
  30
  31 /*
  32  * See
  33  *
  34  * http://www.cisco.com/univercd/cc/td/doc/product/software/ssr90/rpc_r/18059.pdf
  35  */
  36
  37 static int proto_snaeth = -1;
  38 static int hf_snaeth_len = -1;
  39
  40 static gint ett_snaeth = -1;
  41
  42 static dissector_handle_t llc_handle;
  43
  44 static void
  45 dissect_snaeth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  46 {
  47         proto_tree      *snaeth_tree;
  48         proto_item      *snaeth_ti;
  49         guint16         len;
  50         tvbuff_t        *next_tvb;
  51
  52         col_set_str(pinfo->cinfo, COL_PROTOCOL, "SNAETH");
  53         col_set_str(pinfo->cinfo, COL_INFO, "SNA over Ethernet");
  54
  55         /* length */
  56         len = tvb_get_ntohs(tvb, 0);
  57
  58         if (tree) {
  59                 snaeth_ti = proto_tree_add_item(tree, proto_snaeth, tvb, 0, 3,
  60                     ENC_NA);
  61                 snaeth_tree = proto_item_add_subtree(snaeth_ti, ett_snaeth);
  62                 proto_tree_add_uint(snaeth_tree, hf_snaeth_len, tvb, 0, 2, len);
  63                 proto_tree_add_text(snaeth_tree, tvb, 2, 1, "Padding");
  64         }
  65
  66         /*
  67          * Adjust the length of this tvbuff to include only the SNA-over-
  68          * Ethernet header and data.
  69          */
  70         set_actual_length(tvb, 3 + len);
  71
  72         /*
  73          * Rest of packet starts with an 802.2 LLC header.
  74          */
  75         next_tvb = tvb_new_subset_remaining(tvb, 3);
  76         call_dissector(llc_handle, next_tvb, pinfo, tree);
  77 }
  78
  79 void
  80 proto_register_snaeth(void)
  81 {
  82         static hf_register_info hf[] = {
  83                 { &hf_snaeth_len,
  84                 { "Length",     "snaeth.len", FT_UINT16, BASE_DEC, NULL, 0x0,
  85                         "Length of LLC payload", HFILL }},
  86         };
  87         static gint *ett[] = {
  88                 &ett_snaeth,
  89         };
  90
  91         proto_snaeth = proto_register_protocol("SNA-over-Ethernet",
  92             "SNAETH", "snaeth");
  93         proto_register_field_array(proto_snaeth, hf, array_length(hf));
  94         proto_register_subtree_array(ett, array_length(ett));
  95 }
  96
  97 void
  98 proto_reg_handoff_snaeth(void)
  99 {
 100         dissector_handle_t snaeth_handle;
 101
 102         /*
 103          * Get handle for the LLC dissector.
 104          */
 105         llc_handle = find_dissector("llc");
 106
 107         snaeth_handle = create_dissector_handle(dissect_snaeth, proto_snaeth);
 108         dissector_add_uint("ethertype", ETHERTYPE_SNA, snaeth_handle);
 109 }