epan/dissectors/packet-etherip.c

   1 /*
   2  * Copyright (c) 2003 Markus Friedl.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  *
  24  * $Id$
  25  */
  26 #include "config.h"
  27
  28 #include <glib.h>
  29 #include <epan/packet.h>
  30 #include <epan/ipproto.h>
  31 #include <epan/expert.h>
  32
  33 void proto_register_etherip(void);
  34 void proto_reg_handoff_etherip(void);
  35
  36 static int proto_etherip = -1;
  37 static int hf_etherip_ver = -1;
  38 static int hf_etherip_reserved = -1;
  39
  40 static gint ett_etherip = -1;
  41
  42 static expert_field ei_etherip_ver_3 = EI_INIT;
  43 static expert_field ei_etherip_reserved_0 = EI_INIT;
  44
  45 static dissector_handle_t eth_withoutfcs_handle;
  46
  47
  48 /*
  49  * RFC 3378: EtherIP: Tunneling Ethernet Frames in IP Datagrams
  50  *
  51  *      Bits 0-3:  Protocol version
  52  *      Bits 4-15: Reserved for future use
  53  */
  54
  55 #define ETHERIP_VERS_MASK    0xF000
  56 #define ETHERIP_RESERVE_MASK 0x0FFF
  57
  58
  59 static void
  60 dissect_etherip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  61 {
  62   tvbuff_t *next_tvb;
  63   proto_tree *etherip_tree;
  64   proto_item *ti;
  65   guint16 field, version;
  66
  67   col_set_str(pinfo->cinfo, COL_PROTOCOL, "ETHERIP");
  68
  69   field = tvb_get_ntohs(tvb, 0);
  70   version = (field & ETHERIP_VERS_MASK) >> 12;
  71
  72   if (tree) {
  73     ti = proto_tree_add_protocol_format(tree, proto_etherip, tvb, 0,
  74              2,
  75              "EtherIP, Version %d",
  76              version
  77              );
  78     etherip_tree = proto_item_add_subtree(ti, ett_etherip);
  79
  80     ti = proto_tree_add_item(etherip_tree, hf_etherip_ver, tvb,
  81              0, 2, ENC_BIG_ENDIAN);
  82     if (version != 3) {
  83       expert_add_info(pinfo, ti, &ei_etherip_ver_3);
  84     }
  85
  86     ti = proto_tree_add_item(etherip_tree, hf_etherip_reserved, tvb,
  87              0, 2, ENC_BIG_ENDIAN);
  88     if ((field & ETHERIP_RESERVE_MASK) != 0) {
  89       expert_add_info(pinfo, ti, &ei_etherip_reserved_0);
  90     }
  91   }
  92
  93   /* Set the tvbuff for the payload after the header */
  94   next_tvb = tvb_new_subset_remaining(tvb, 2);
  95
  96   call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree);
  97 }
  98
  99 void
 100 proto_register_etherip(void)
 101 {
 102   static hf_register_info hf_etherip[] = {
 103     { &hf_etherip_ver,
 104       { "Version", "etherip.ver", FT_UINT16, BASE_DEC, NULL, ETHERIP_VERS_MASK,
 105         NULL, HFILL }},
 106     { &hf_etherip_reserved,
 107       { "Reserved", "etherip.reserved", FT_UINT16, BASE_HEX, NULL, ETHERIP_RESERVE_MASK,
 108         "Reserved (must be 0)", HFILL }},
 109   };
 110
 111   static gint *ett[] = {
 112     &ett_etherip,
 113   };
 114
 115   static ei_register_info ei[] = {
 116      { &ei_etherip_ver_3, { "etherip.ver.not3", PI_PROTOCOL, PI_WARN, "Version must be 3", EXPFILL }},
 117      { &ei_etherip_reserved_0, { "etherip.reserved.not0", PI_PROTOCOL, PI_WARN, "Reserved field must be 0", EXPFILL }},
 118   };
 119
 120   expert_module_t* expert_etherip;
 121
 122   proto_etherip = proto_register_protocol("Ethernet over IP",
 123                                           "ETHERIP", "etherip");
 124   proto_register_field_array(proto_etherip, hf_etherip, array_length(hf_etherip));
 125   proto_register_subtree_array(ett, array_length(ett));
 126   expert_etherip = expert_register_protocol(proto_etherip);
 127   expert_register_field_array(expert_etherip, ei, array_length(ei));
 128
 129   register_dissector("etherip", dissect_etherip, proto_etherip);
 130 }
 131
 132 void
 133 proto_reg_handoff_etherip(void)
 134 {
 135   dissector_handle_t etherip_handle;
 136
 137   eth_withoutfcs_handle = find_dissector("eth_withoutfcs");
 138   etherip_handle = find_dissector("etherip");
 139   dissector_add_uint("ip.proto", IP_PROTO_ETHERIP, etherip_handle);
 140 }