ui/cli/tap-protocolinfo.c

   1 /* tap-protocolinfo.c
   2  * protohierstat   2002 Ronnie Sahlberg
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998 Gerald Combs
   7  *
   8  * SPDX-License-Identifier: GPL-2.0+*/
   9
  10 /* This module provides Protocol Column Info tap for tshark */
  11
  12 #include "config.h"
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17
  18 #include "epan/epan_dissect.h"
  19 #include "epan/column-utils.h"
  20 #include <epan/tap.h>
  21 #include <epan/stat_tap_ui.h>
  22
  23 void register_tap_listener_protocolinfo(void);
  24
  25 typedef struct _pci_t {
  26         char *filter;
  27         int hf_index;
  28 } pci_t;
  29
  30
  31 static int
  32 protocolinfo_packet(void *prs, packet_info *pinfo, epan_dissect_t *edt, const void *dummy _U_)
  33 {
  34         pci_t *rs = (pci_t *)prs;
  35         GPtrArray *gp;
  36         guint i;
  37         char *str;
  38
  39         /*
  40          * XXX - there needs to be a way for "protocolinfo_init()" to
  41          * find out whether the columns are being generated and, if not,
  42          * to report an error and exit, as the whole point of this tap
  43          * is to modify the columns, and if the columns aren't being
  44          * displayed, that makes this tap somewhat pointless.
  45          *
  46          * To prevent a crash, we check whether INFO column is writable
  47          * and, if not, we report that error and exit.
  48          */
  49         if (!col_get_writable(pinfo->cinfo, COL_INFO)) {
  50                 fprintf(stderr, "tshark: the proto,colinfo tap doesn't work if the INFO column isn't being printed.\n");
  51                 exit(1);
  52         }
  53         gp = proto_get_finfo_ptr_array(edt->tree, rs->hf_index);
  54         if (!gp) {
  55                 return 0;
  56         }
  57
  58         for (i=0; i<gp->len; i++) {
  59                 str = (char *)proto_construct_match_selected_string((field_info *)gp->pdata[i], NULL);
  60                 if (str) {
  61                         col_append_fstr(pinfo->cinfo, COL_INFO, "  %s", str);
  62                         wmem_free(NULL, str);
  63                 }
  64         }
  65         return 0;
  66 }
  67
  68
  69
  70 static void
  71 protocolinfo_init(const char *opt_arg, void *userdata _U_)
  72 {
  73         pci_t *rs;
  74         const char *field = NULL;
  75         const char *filter = NULL;
  76         header_field_info *hfi;
  77         GString *error_string;
  78
  79         if (!strncmp("proto,colinfo,", opt_arg, 14)) {
  80                 filter = opt_arg+14;
  81                 field = strchr(filter, ',');
  82                 if (field) {
  83                         field += 1;  /* skip the ',' */
  84                 }
  85         }
  86         if (!field) {
  87                 fprintf(stderr, "tshark: invalid \"-z proto,colinfo,<filter>,<field>\" argument\n");
  88                 exit(1);
  89         }
  90
  91         hfi = proto_registrar_get_byname(field);
  92         if (!hfi) {
  93                 fprintf(stderr, "tshark: Field \"%s\" doesn't exist.\n", field);
  94                 exit(1);
  95         }
  96
  97         rs = g_new(pci_t, 1);
  98         rs->hf_index = hfi->id;
  99         if ((field-filter) > 1) {
 100                 rs->filter = (char *)g_malloc(field-filter);
 101                 g_strlcpy(rs->filter, filter, (field-filter));
 102         } else {
 103                 rs->filter = NULL;
 104         }
 105
 106         error_string = register_tap_listener("frame", rs, rs->filter, TL_REQUIRES_PROTO_TREE, NULL, protocolinfo_packet, NULL);
 107         if (error_string) {
 108                 /* error, we failed to attach to the tap. complain and clean up */
 109                 fprintf(stderr, "tshark: Couldn't register proto,colinfo tap: %s\n",
 110                     error_string->str);
 111                 g_string_free(error_string, TRUE);
 112                 g_free(rs->filter);
 113                 g_free(rs);
 114
 115                 exit(1);
 116         }
 117 }
 118
 119 static stat_tap_ui protocolinfo_ui = {
 120         REGISTER_STAT_GROUP_GENERIC,
 121         NULL,
 122         "proto,colinfo",
 123         protocolinfo_init,
 124         0,
 125         NULL
 126 };
 127
 128 void
 129 register_tap_listener_protocolinfo(void)
 130 {
 131         register_stat_tap_ui(&protocolinfo_ui, NULL);
 132 }
 133
 134 /*
 135  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 136  *
 137  * Local variables:
 138  * c-basic-offset: 8
 139  * tab-width: 8
 140  * indent-tabs-mode: t
 141  * End:
 142  *
 143  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 144  * :indentSize=8:tabSize=8:noTabs=false:
 145  */