tap-protocolinfo.c

   1 /* tap-protocolinfo.c
   2  * protohierstat   2002 Ronnie Sahlberg
   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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  23  */
  24
  25 /* This module provides Protocol Column Info tap for tshark */
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <stdio.h>
  32
  33 #ifdef HAVE_SYS_TYPES_H
  34 # include <sys/types.h>
  35 #endif
  36
  37 #include <string.h>
  38 #include "epan/epan_dissect.h"
  39 #include "epan/column-utils.h"
  40 #include "epan/proto.h"
  41 #include <epan/tap.h>
  42 #include <epan/stat_cmd_args.h>
  43 #include "register.h"
  44
  45 typedef struct _pci_t {
  46         char *filter;
  47         int hf_index;
  48 } pci_t;
  49
  50
  51 static int
  52 protocolinfo_packet(void *prs, packet_info *pinfo, epan_dissect_t *edt, const void *dummy _U_)
  53 {
  54         pci_t *rs=prs;
  55         GPtrArray *gp;
  56         guint i;
  57         char *str;
  58
  59         /*
  60          * XXX - there needs to be a way for "protocolinfo_init()" to
  61          * find out whether the columns are being generated and, if not,
  62          * to report an error and exit, as the whole point of this tap
  63          * is to modify the columns, and if the columns aren't being
  64          * displayed, that makes this tap somewhat pointless.
  65          *
  66          * To prevent a crash, we check whether pinfo->cinfo is null
  67          * and, if so, we report that error and exit.
  68          */
  69         if (pinfo->cinfo == NULL) {
  70                 fprintf(stderr, "tshark: the proto,colinfo tap doesn't work if the columns aren't being printed.\n");
  71                 exit(1);
  72         }
  73         gp=proto_get_finfo_ptr_array(edt->tree, rs->hf_index);
  74         if(!gp){
  75                 return 0;
  76         }
  77
  78         for(i=0;i<gp->len;i++){
  79                 if(proto_construct_match_selected_string(gp->pdata[i], NULL, &str)){
  80                         col_append_fstr(pinfo->cinfo, COL_INFO, "  %s",str);
  81                 }
  82         }
  83         return 0;
  84 }
  85
  86
  87
  88 static void
  89 protocolinfo_init(const char *optarg, void* userdata _U_)
  90 {
  91         pci_t *rs;
  92         const char *field=NULL;
  93         const char *filter=NULL;
  94         header_field_info *hfi;
  95         GString *error_string;
  96
  97         if(!strncmp("proto,colinfo,",optarg,14)){
  98                 filter=optarg+14;
  99                 field=strchr(filter,',');
 100                 if(field){
 101                         field+=1;  /* skip the ',' */
 102                 }
 103         }
 104         if(!field){
 105                 fprintf(stderr, "tshark: invalid \"-z proto,colinfo,<filter>,<field>\" argument\n");
 106                 exit(1);
 107         }
 108
 109         hfi=proto_registrar_get_byname(field);
 110         if(!hfi){
 111                 fprintf(stderr, "tshark: Field \"%s\" doesn't exist.\n", field);
 112                 exit(1);
 113         }
 114
 115         rs=g_malloc(sizeof(pci_t));
 116         rs->hf_index=hfi->id;
 117         if((field-filter)>1){
 118                 rs->filter=g_malloc(field-filter);
 119                 strncpy(rs->filter,filter,(field-filter)-1);
 120                 rs->filter[(field-filter)-1]=0;
 121         } else {
 122                 rs->filter=NULL;
 123         }
 124
 125         error_string=register_tap_listener("frame", rs, rs->filter, NULL, protocolinfo_packet, NULL);
 126         if(error_string){
 127                 /* error, we failed to attach to the tap. complain and clean up */
 128                 fprintf(stderr, "tshark: Couldn't register proto,colinfo tap: %s\n",
 129                     error_string->str);
 130                 g_string_free(error_string, TRUE);
 131                 if(rs->filter){
 132                         g_free(rs->filter);
 133                 }
 134                 g_free(rs);
 135
 136                 exit(1);
 137         }
 138 }
 139
 140
 141 void
 142 register_tap_listener_protocolinfo(void)
 143 {
 144         register_stat_cmd_arg("proto,colinfo,", protocolinfo_init,NULL);
 145 }
 146