epan/dissectors/packet-symantec.c

   1 /* packet-symantec.c
   2  * Routines for dissection of packets from the Axent Raptor firewall/
   3  * Symantec Enterprise Firewall/Symantec Gateway Security appliance
   4  * v2/Symantec Gateway Security appliance v3.
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29
  30 #include <epan/packet.h>
  31
  32 #include <epan/etypes.h>
  33
  34 static dissector_table_t ethertype_dissector_table;
  35
  36 /* protocols and header fields */
  37 static int proto_symantec = -1;
  38 static int hf_symantec_if = -1;
  39 static int hf_symantec_etype = -1;
  40
  41 static gint ett_symantec = -1;
  42
  43 static void
  44 dissect_symantec(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  45 {
  46         proto_item *ti;
  47         proto_tree *symantec_tree = NULL;
  48         guint16 etypev2, etypev3;
  49         tvbuff_t *next_tvb;
  50
  51         /*
  52          * Symantec records come in two variants:
  53          *
  54          * The older variant, dating from Axent days and continuing until
  55          * the SGS v2.0.1 code level, is 44 bytes long.
  56          * The first 4 bytes are the IPv4 address of the interface that
  57          * captured the data, followed by 2 bytes of 0, then an Ethernet
  58          * type, followed by 36 bytes of 0.
  59          *
  60          * The newer variant, introduced either in SGS v3.0 or v3.0.1
  61          * (possibly in concert with VLAN support), is 56 bytes long.
  62          * The first 4 bytes are the IPv4 address of the interface that
  63          * captured the data, followed by 6 bytes of 0, then an Ethernet
  64          * type, followed by 44 bytes of 0.
  65          *
  66          * Unfortunately, there is no flag to distiguish between the two
  67          * flavours.  The only indication of which flavour you have is the
  68          * offset of the ETHERTYPE field.  Fortunately, Symantec didn't
  69          * use ETHERTYPE_UNK as a valid value.
  70          */
  71
  72         etypev2 = tvb_get_ntohs(tvb, 6);
  73         etypev3 = tvb_get_ntohs(tvb, 10);
  74
  75         /* a valid packet can't be both v2 and v3 or neither v2 nor v3, */
  76         if ((etypev2 == 0) == (etypev3 == 0))
  77                 return;
  78
  79         col_set_str(pinfo->cinfo, COL_PROTOCOL, "Symantec");
  80
  81         if (etypev3 == 0) {     /* SEF and SGS v2 processing */
  82                 col_set_str(pinfo->cinfo, COL_INFO, "Symantec Enterprise Firewall");
  83                 if (tree) {
  84                         ti = proto_tree_add_protocol_format(tree, proto_symantec, tvb,
  85                                 0, 44, "Symantec firewall");
  86                         symantec_tree = proto_item_add_subtree(ti, ett_symantec);
  87                 }
  88                 if (tree) {
  89                         proto_tree_add_item(symantec_tree, hf_symantec_if, tvb,
  90                                 0, 4, ENC_BIG_ENDIAN);
  91                         proto_tree_add_uint(symantec_tree, hf_symantec_etype, tvb,
  92                                 6, 2, etypev2);
  93                 }
  94                 next_tvb = tvb_new_subset_remaining(tvb, 44);
  95                 dissector_try_uint(ethertype_dissector_table, etypev2, next_tvb, pinfo,
  96                         tree);
  97         }
  98
  99         if (etypev2 == 0) {     /* SGS v3 processing */
 100                 col_set_str(pinfo->cinfo, COL_INFO, "Symantec SGS v3");
 101                 if (tree) {
 102                         ti = proto_tree_add_protocol_format(tree, proto_symantec, tvb,
 103                                 0, 56, "Symantec SGSv3");
 104                         symantec_tree = proto_item_add_subtree(ti, ett_symantec);
 105                 }
 106                 if (tree) {
 107                         proto_tree_add_item(symantec_tree, hf_symantec_if, tvb,
 108                                 0, 4, ENC_BIG_ENDIAN);
 109                         proto_tree_add_uint(symantec_tree, hf_symantec_etype, tvb,
 110                                 10, 2, etypev3);
 111                 }
 112                 /*
 113                  * Dissection of VLAN information will have to wait until
 114                  * availability of a capture file from an SGSv3 box using VLAN
 115                  * tagging.
 116                  */
 117                 next_tvb = tvb_new_subset_remaining(tvb, 56);
 118                 dissector_try_uint(ethertype_dissector_table, etypev3, next_tvb, pinfo,
 119                         tree);
 120         }
 121 }
 122
 123 void
 124 proto_register_symantec(void)
 125 {
 126         static hf_register_info hf[] = {
 127                 { &hf_symantec_if,
 128                     { "Interface", "symantec.if", FT_IPv4,  BASE_NONE, NULL, 0x0,
 129                         NULL, HFILL }},
 130                 { &hf_symantec_etype,
 131                     { "Type",    "symantec.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
 132                         NULL, HFILL }},
 133         };
 134         static gint *ett[] = {
 135                 &ett_symantec,
 136         };
 137
 138         proto_symantec = proto_register_protocol("Symantec Enterprise Firewall",
 139             "Symantec", "symantec");
 140         proto_register_field_array(proto_symantec, hf, array_length(hf));
 141         proto_register_subtree_array(ett, array_length(ett));
 142 }
 143
 144 void
 145 proto_reg_handoff_symantec(void)
 146 {
 147         dissector_handle_t symantec_handle;
 148
 149         ethertype_dissector_table = find_dissector_table("ethertype");
 150
 151         symantec_handle = create_dissector_handle(dissect_symantec,
 152             proto_symantec);
 153         dissector_add_uint("wtap_encap", WTAP_ENCAP_SYMANTEC, symantec_handle);
 154 }