packet-ethertype.c

   1 /* ethertype.c
   2  * Routines for calling the right protocol for the ethertype.
   3  *
   4  * $Id: packet-ethertype.c,v 1.9 2000/11/18 10:38:24 guy Exp $
   5  *
   6  * Gilbert Ramirez <gram@xiexie.org>
   7  *
   8  * Ethereal - Network traffic analyzer
   9  * By Gerald Combs <gerald@zing.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  26  */
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #ifdef HAVE_SYS_TYPES_H
  33 # include <sys/types.h>
  34 #endif
  35
  36 #include <glib.h>
  37 #include "packet.h"
  38 #include "packet-ip.h"
  39 #include "packet-ipx.h"
  40 #include "packet-vlan.h"
  41 #include "packet-vines.h"
  42 #include "etypes.h"
  43
  44 static dissector_table_t ethertype_dissector_table;
  45
  46 const value_string etype_vals[] = {
  47     {ETHERTYPE_IP,              "IP"                            },
  48     {ETHERTYPE_IPv6,            "IPv6"                          },
  49     {ETHERTYPE_X25L3,           "X.25 Layer 3"                  },
  50     {ETHERTYPE_ARP,             "ARP"                           },
  51     {ETHERTYPE_REVARP,          "RARP"                          },
  52     {ETHERTYPE_DEC_LB,          "DEC LanBridge"                 },
  53     {ETHERTYPE_ATALK,           "Appletalk"                     },
  54     {ETHERTYPE_AARP,            "AARP"                          },
  55     {ETHERTYPE_IPX,             "Netware IPX/SPX"               },
  56     {ETHERTYPE_VINES,           "Vines"                         },
  57     {ETHERTYPE_TRAIN,           "Netmon Train"                  },
  58     {ETHERTYPE_LOOP,            "Loopback"                      }, /* Ethernet Loopback */
  59     {ETHERTYPE_PPPOED,          "PPPoE Discovery"               },
  60     {ETHERTYPE_PPPOES,          "PPPoE Session"                 },
  61     {ETHERTYPE_VLAN,            "802.1Q Virtual LAN"            },
  62     {ETHERTYPE_MPLS,            "MPLS label switched packet"    },
  63     {ETHERTYPE_MPLS_MULTI,      "MPLS multicast label switched packet" },
  64     {ETHERTYPE_3C_NBP_DGRAM,    "3Com NBP Datagram"             },
  65     {ETHERTYPE_DEC,             "DEC proto"                     },
  66     {ETHERTYPE_DNA_DL,          "DEC DNA Dump/Load"             },
  67     {ETHERTYPE_DNA_RC,          "DEC DNA Remote Console"        },
  68     {ETHERTYPE_DNA_RT,          "DEC DNA Routing"               },
  69     {ETHERTYPE_LAT,             "DEC LAT"                       },
  70     {ETHERTYPE_DEC_DIAG,        "DEC Diagnostics"               },
  71     {ETHERTYPE_DEC_CUST,        "DEC Customer use"              },
  72     {ETHERTYPE_DEC_SCA,         "DEC LAVC/SCA"                  },
  73     {0,                         NULL                            } };
  74
  75 void
  76 capture_ethertype(guint16 etype, int offset,
  77                 const u_char *pd, packet_counts *ld)
  78 {
  79   switch (etype) {
  80     case ETHERTYPE_IP:
  81       capture_ip(pd, offset, ld);
  82       break;
  83     case ETHERTYPE_IPX:
  84       capture_ipx(pd, offset, ld);
  85       break;
  86     case ETHERTYPE_VLAN:
  87       capture_vlan(pd, offset, ld);
  88       break;
  89     case ETHERTYPE_VINES:
  90       capture_vines(pd, offset, ld);
  91       break;
  92     default:
  93       ld->other++;
  94       break;
  95   }
  96 }
  97
  98 guint
  99 ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype, packet_info *pinfo,
 100                 proto_tree *tree, proto_tree *fh_tree, int item_id)
 101 {
 102         char            *description;
 103         tvbuff_t        *next_tvb;
 104
 105         /* Add to proto_tree */
 106         if (tree) {
 107                 proto_tree_add_uint(fh_tree, item_id, tvb, offset_after_etype - 2, 2, etype);
 108         }
 109
 110         /* Tvbuff for the payload after the Ethernet type. */
 111         next_tvb = tvb_new_subset(tvb, offset_after_etype, -1, -1);
 112
 113         /* Look for sub-dissector */
 114         if (!dissector_try_port(ethertype_dissector_table, etype,
 115             next_tvb, pinfo, tree)) {
 116                 /* No sub-dissector found.
 117                    Label rest of packet as "Data" */
 118                 dissect_data(next_tvb, 0, pinfo, tree);
 119
 120                 /* Label protocol */
 121                 switch(etype) {
 122
 123                 case ETHERTYPE_LOOP:
 124                         if (check_col(pinfo->fd, COL_PROTOCOL)) {
 125                                 col_add_fstr(pinfo->fd, COL_PROTOCOL, "LOOP");
 126                         }
 127                         break;
 128                 default:
 129                         if (check_col(pinfo->fd, COL_PROTOCOL)) {
 130                                 col_add_fstr(pinfo->fd, COL_PROTOCOL, "0x%04x", etype);
 131                         }
 132                         break;
 133                 }
 134                 if (check_col(pinfo->fd, COL_INFO)) {
 135                         description = match_strval(etype, etype_vals);
 136                         if (description) {
 137                                 col_add_fstr(pinfo->fd, COL_INFO, "%s", description);
 138                         }
 139                 }
 140         }
 141
 142         /* Return the length of that tvbuff; the subdissector may have
 143            reduced the length to a value specified by a length field
 144            in its header, meaning what remains is padding. */
 145         return tvb_reported_length(next_tvb);
 146 }
 147
 148
 149 void
 150 proto_register_ethertype(void)
 151 {
 152         /* subdissector code */
 153         ethertype_dissector_table = register_dissector_table("ethertype");
 154 }