epan/dissectors/packet-user_encap.c

   1 /* packet-user_encap.c
   2  * Allow users to specify the dissectors for USERn DLTs
   3  * Luis E. Garcia Ontanon <luis.ontanon@gmail.com>
   4  *
   5  * $Id$
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998
  10  *
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  *  of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <glib.h>
  32 #include <epan/packet.h>
  33 #include <epan/prefs.h>
  34 #include <epan/report_err.h>
  35
  36 #include <epan/dissectors/packet-sscop.h>
  37
  38 typedef void (*encap_dissector_t)(tvbuff_t*,packet_info*,proto_tree*,dissector_handle_t);
  39
  40 typedef struct _user_encap_t {
  41         gchar* name;
  42         gchar* abbr;
  43         gchar* long_name;
  44
  45         gchar* payload;
  46         gchar* header;
  47         gchar* trailer;
  48         guint header_size;
  49         guint trailer_size;
  50
  51         int hfid;
  52
  53         gint encap;
  54
  55         encap_dissector_t encap_dissector;
  56         dissector_t dissector;
  57
  58         module_t* module;
  59
  60         dissector_handle_t handle;
  61         dissector_handle_t payload_handle;
  62         dissector_handle_t header_handle;
  63         dissector_handle_t trailer_handle;
  64 } user_encap_t;
  65
  66 static const enum_val_t encap_types[] = {
  67         { "None", "No encpsulation", 0 },
  68         { "SSCOP" , "SSCOP", 1 },
  69         { NULL, NULL, 0 }
  70 };
  71
  72 static const encap_dissector_t encap_dissectors[] = {
  73         NULL,
  74         dissect_sscop_and_payload
  75 };
  76
  77 static void dissect_user(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree,guint id);
  78
  79 static void dissect_user0(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,0); }
  80 static void dissect_user1(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,1); }
  81 static void dissect_user2(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,2); }
  82 static void dissect_user3(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,3); }
  83 static void dissect_user4(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,4); }
  84 static void dissect_user5(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,5); }
  85 static void dissect_user6(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,6); }
  86 static void dissect_user7(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,7); }
  87 static void dissect_user8(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,8); }
  88 static void dissect_user9(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,9); }
  89 static void dissect_user10(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,10); }
  90 static void dissect_user11(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,11); }
  91 static void dissect_user12(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,12); }
  92 static void dissect_user13(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,13); }
  93 static void dissect_user14(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,14); }
  94 static void dissect_user15(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree) { dissect_user(tvb,pinfo,tree,15); }
  95
  96 user_encap_t encaps[] = {
  97         {"USER0","user0","DLT_USER00","","","",0,0,-1,0,NULL,dissect_user0,NULL,NULL,NULL,NULL,NULL},
  98         {"USER1","user1","DLT_USER01","","","",0,0,-1,0,NULL,dissect_user1,NULL,NULL,NULL,NULL,NULL},
  99         {"USER2","user2","DLT_USER02","","","",0,0,-1,0,NULL,dissect_user2,NULL,NULL,NULL,NULL,NULL},
 100         {"USER3","user3","DLT_USER03","","","",0,0,-1,0,NULL,dissect_user3,NULL,NULL,NULL,NULL,NULL},
 101         {"USER4","user4","DLT_USER04","","","",0,0,-1,0,NULL,dissect_user4,NULL,NULL,NULL,NULL,NULL},
 102         {"USER5","user5","DLT_USER05","","","",0,0,-1,0,NULL,dissect_user5,NULL,NULL,NULL,NULL,NULL},
 103         {"USER6","user6","DLT_USER06","","","",0,0,-1,0,NULL,dissect_user6,NULL,NULL,NULL,NULL,NULL},
 104         {"USER7","user7","DLT_USER07","","","",0,0,-1,0,NULL,dissect_user7,NULL,NULL,NULL,NULL,NULL},
 105         {"USER8","user8","DLT_USER08","","","",0,0,-1,0,NULL,dissect_user8,NULL,NULL,NULL,NULL,NULL},
 106         {"USER9","user9","DLT_USER09","","","",0,0,-1,0,NULL,dissect_user9,NULL,NULL,NULL,NULL,NULL},
 107         {"USER10","user10","DLT_USER10","","","",0,0,-1,0,NULL,dissect_user10,NULL,NULL,NULL,NULL,NULL},
 108         {"USER11","user11","DLT_USER11","","","",0,0,-1,0,NULL,dissect_user11,NULL,NULL,NULL,NULL,NULL},
 109         {"USER12","user12","DLT_USER12","","","",0,0,-1,0,NULL,dissect_user12,NULL,NULL,NULL,NULL,NULL},
 110         {"USER13","user13","DLT_USER13","","","",0,0,-1,0,NULL,dissect_user13,NULL,NULL,NULL,NULL,NULL},
 111         {"USER14","user14","DLT_USER14","","","",0,0,-1,0,NULL,dissect_user14,NULL,NULL,NULL,NULL,NULL},
 112         {"USER15","user15","DLT_USER15","","","",0,0,-1,0,NULL,dissect_user15,NULL,NULL,NULL,NULL,NULL},
 113 };
 114
 115 static void dissect_user(tvbuff_t* tvb,packet_info* pinfo,proto_tree* tree,guint id) {
 116         user_encap_t* encap = &(encaps[id]);
 117         tvbuff_t* payload_tvb;
 118         int offset = 0;
 119         int len = tvb_reported_length(tvb) - (encap->header_size + encap->trailer_size);
 120
 121         if (encap->encap_dissector) {
 122                 encap->encap_dissector(tvb,pinfo,tree,encap->payload_handle);
 123                 return;
 124         }
 125
 126         if (encap->header_size) {
 127                 tvbuff_t* hdr_tvb = tvb_new_subset(tvb, 0, encap->header_size, encap->header_size);
 128                 call_dissector(encap->header_handle, hdr_tvb, pinfo, tree);
 129                 offset = encap->header_size;
 130         }
 131
 132         payload_tvb = tvb_new_subset(tvb, encap->header_size, len, len);
 133         call_dissector(encap->payload_handle, payload_tvb, pinfo, tree);
 134
 135         if (encap->trailer_size) {
 136                 tvbuff_t* trailer_tvb = tvb_new_subset(tvb, encap->header_size + len, encap->trailer_size, encap->trailer_size);
 137                 call_dissector(encap->trailer_handle, trailer_tvb, pinfo, tree);
 138                 offset = encap->trailer_size;
 139         }
 140 }
 141
 142 void proto_reg_handoff_user_encap(void)
 143 {
 144         int i;
 145         static dissector_handle_t data_handle;
 146
 147         data_handle = find_dissector("data");
 148
 149         for (i = 0; i < 16; i++) {
 150                 encaps[i].handle =  find_dissector(encaps[i].abbr);
 151                 dissector_add("wtap_encap", WTAP_ENCAP_USER0 + i, encaps[i].handle);
 152
 153                 if(*(encaps[i].payload) != '\0') {
 154                         encaps[i].payload_handle = find_dissector(encaps[i].payload);
 155
 156                         if (encaps[i].payload_handle == NULL) {
 157                                 encaps[i].payload_handle = data_handle;
 158                                 report_failure("%s: No such proto: %s",encaps[i].long_name,encaps[i].payload);
 159                         }
 160                 } else {
 161                         encaps[i].payload_handle = data_handle;
 162                 }
 163
 164                 if(*(encaps[i].header) != '\0') {
 165                         encaps[i].header_handle = find_dissector(encaps[i].header);
 166
 167                         if (encaps[i].header_handle == NULL) {
 168                                 encaps[i].header_handle = data_handle;
 169                                 report_failure("%s: No such proto: %s",encaps[i].long_name,encaps[i].header);
 170                         }
 171                 } else {
 172                         encaps[i].header_handle = data_handle;
 173                 }
 174
 175                 if(*(encaps[i].trailer) != '\0') {
 176                         encaps[i].trailer_handle = find_dissector(encaps[i].trailer);
 177
 178                         if (encaps[i].trailer_handle == NULL) {
 179                                 encaps[i].trailer_handle = data_handle;
 180                                 report_failure("%s: No such proto: %s",encaps[i].long_name,encaps[i].trailer);
 181                         }
 182                 } else {
 183                         encaps[i].trailer_handle = data_handle;
 184                 }
 185
 186                 encaps[i].encap_dissector = encap_dissectors[encaps[i].encap];
 187         }
 188 }
 189
 190 void proto_register_user_encap(void)
 191 {
 192         int i;
 193
 194         for (i = 0; i < 16; i++) {
 195                 encaps[i].hfid = proto_register_protocol(encaps[i].name, encaps[i].long_name, encaps[i].abbr);
 196                 encaps[i].module = prefs_register_protocol(encaps[i].hfid, proto_reg_handoff_user_encap);
 197
 198                 prefs_register_string_preference(encaps[i].module, "payload","Payload", "Payload", &encaps[i].payload);
 199                 prefs_register_enum_preference(encaps[i].module, "encap","Encapsulation", "The encapsulation used", &encaps[i].encap, encap_types, FALSE);
 200                 prefs_register_uint_preference(encaps[i].module, "header_size","Header Size", "The size (in bytes) of the Header (0 if none)", 10, &encaps[i].header_size);
 201                 prefs_register_uint_preference(encaps[i].module, "trailer_size","Trailer Size", "The size (in bytes) of the Trailer (0 if none)", 10, &encaps[i].trailer_size);
 202                 prefs_register_string_preference(encaps[i].module, "header_proto","Header Protocol", "Header Protocol (used only when ecapsulation is not given)", &encaps[i].header);
 203                 prefs_register_string_preference(encaps[i].module, "trailer_proto","Trailer Protocol", "Trailer Protocol (used only when ecapsulation is not given)", &encaps[i].trailer);
 204
 205                 register_dissector(encaps[i].abbr, encaps[i].dissector, encaps[i].hfid);
 206         }
 207 }