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[obnox/wireshark/wip.git] / 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 <epan/strutil.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 INFO column is writable
67          * and, if not, we report that error and exit.
68          */
69         if (!check_col(pinfo->cinfo, COL_INFO)) {
70                 fprintf(stderr, "tshark: the proto,colinfo tap doesn't work if the INFO column isn'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                 str=proto_construct_match_selected_string(gp->pdata[i], NULL);
80                 if(str){
81                         col_append_fstr(pinfo->cinfo, COL_INFO, "  %s",str);
82                 }
83         }
84         return 0;
85 }
86
87
88
89 static void
90 protocolinfo_init(const char *optarg, void* userdata _U_)
91 {
92         pci_t *rs;
93         const char *field=NULL;
94         const char *filter=NULL;
95         header_field_info *hfi;
96         GString *error_string;
97
98         if(!strncmp("proto,colinfo,",optarg,14)){
99                 filter=optarg+14;
100                 field=strchr(filter,',');
101                 if(field){
102                         field+=1;  /* skip the ',' */
103                 }
104         }
105         if(!field){
106                 fprintf(stderr, "tshark: invalid \"-z proto,colinfo,<filter>,<field>\" argument\n");
107                 exit(1);
108         }
109
110         hfi=proto_registrar_get_byname(field);
111         if(!hfi){
112                 fprintf(stderr, "tshark: Field \"%s\" doesn't exist.\n", field);
113                 exit(1);
114         }
115
116         rs=g_malloc(sizeof(pci_t));
117         rs->hf_index=hfi->id;
118         if((field-filter)>1){
119                 rs->filter=g_malloc(field-filter);
120                 g_strlcpy(rs->filter,filter,(field-filter));
121         } else {
122                 rs->filter=NULL;
123         }
124
125         error_string=register_tap_listener("frame", rs, rs->filter, TL_REQUIRES_PROTO_TREE, 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                 g_free(rs->filter);
132                 g_free(rs);
133
134                 exit(1);
135         }
136 }
137
138
139 void
140 register_tap_listener_protocolinfo(void)
141 {
142         register_stat_cmd_arg("proto,colinfo,", protocolinfo_init,NULL);
143 }
144