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-or-later
   9  */
  10
  11 /* This module provides Protocol Column Info tap for tshark */
  12
  13 #include "config.h"
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18
  19 #include "epan/epan_dissect.h"
  20 #include "epan/column-utils.h"
  21 #include <epan/tap.h>
  22 #include <epan/stat_tap_ui.h>
  23
  24 #include <wsutil/cmdarg_err.h>
  25
  26 void register_tap_listener_protocolinfo(void);
  27
  28 typedef struct _pci_t {
  29         char *filter;
  30         int hf_index;
  31 } pci_t;
  32
  33
  34 static tap_packet_status
  35 protocolinfo_packet(void *prs, packet_info *pinfo, epan_dissect_t *edt, const void *dummy _U_, tap_flags_t flags _U_)
  36 {
  37         pci_t *rs = (pci_t *)prs;
  38         GPtrArray *gp;
  39         unsigned i;
  40         char *str;
  41
  42         /*
  43          * XXX - there needs to be a way for "protocolinfo_init()" to
  44          * find out whether the columns are being generated and, if not,
  45          * to report an error and exit, as the whole point of this tap
  46          * is to modify the columns, and if the columns aren't being
  47          * displayed, that makes this tap somewhat pointless.
  48          *
  49          * To prevent a crash, we check whether INFO column is writable
  50          * and, if not, we report that error and exit.
  51          *
  52          * XXX - report the error and just return TAP_PACKET_FAILED?
  53          */
  54         if (!col_get_writable(pinfo->cinfo, COL_INFO)) {
  55                 cmdarg_err("the proto,colinfo tap doesn't work if the INFO column isn't being printed.");
  56                 exit(1);
  57         }
  58         gp = proto_get_finfo_ptr_array(edt->tree, rs->hf_index);
  59         if (!gp) {
  60                 return TAP_PACKET_DONT_REDRAW;
  61         }
  62
  63         for (i=0; i<gp->len; i++) {
  64                 str = (char *)proto_construct_match_selected_string((field_info *)gp->pdata[i], NULL);
  65                 if (str) {
  66                         col_append_fstr(pinfo->cinfo, COL_INFO, "  %s", str);
  67                         wmem_free(NULL, str);
  68                 }
  69         }
  70         return TAP_PACKET_DONT_REDRAW;
  71 }
  72
  73
  74
  75 static void
  76 protocolinfo_init(const char *opt_arg, void *userdata _U_)
  77 {
  78         pci_t *rs;
  79         const char *field = NULL;
  80         const char *filter = NULL;
  81         header_field_info *hfi;
  82         GString *error_string;
  83
  84         if (!strncmp("proto,colinfo,", opt_arg, 14)) {
  85                 filter = opt_arg+14;
  86                 field = strchr(filter, ',');
  87                 if (field) {
  88                         field += 1;  /* skip the ',' */
  89                 }
  90         }
  91         if (!field) {
  92                 cmdarg_err("invalid \"-z proto,colinfo,<filter>,<field>\" argument");
  93                 exit(1);
  94         }
  95
  96         hfi = proto_registrar_get_byname(field);
  97         if (!hfi) {
  98                 cmdarg_err("Field \"%s\" doesn't exist.", field);
  99                 exit(1);
 100         }
 101
 102         rs = g_new(pci_t, 1);
 103         rs->hf_index = hfi->id;
 104         if ((field-filter) > 1) {
 105                 rs->filter = (char *)g_malloc(field-filter);
 106                 (void) g_strlcpy(rs->filter, filter, (field-filter));
 107         } else {
 108                 rs->filter = NULL;
 109         }
 110
 111         error_string = register_tap_listener("frame", rs, rs->filter, TL_REQUIRES_PROTO_TREE, NULL, protocolinfo_packet, NULL, NULL);
 112         if (error_string) {
 113                 /* error, we failed to attach to the tap. complain and clean up */
 114                 cmdarg_err("Couldn't register proto,colinfo tap: %s",
 115                     error_string->str);
 116                 g_string_free(error_string, TRUE);
 117                 g_free(rs->filter);
 118                 g_free(rs);
 119
 120                 exit(1);
 121         }
 122 }
 123
 124 static stat_tap_ui protocolinfo_ui = {
 125         REGISTER_STAT_GROUP_GENERIC,
 126         NULL,
 127         "proto,colinfo",
 128         protocolinfo_init,
 129         0,
 130         NULL
 131 };
 132
 133 void
 134 register_tap_listener_protocolinfo(void)
 135 {
 136         register_stat_tap_ui(&protocolinfo_ui, NULL);
 137 }
 138
 139 /*
 140  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 141  *
 142  * Local variables:
 143  * c-basic-offset: 8
 144  * tab-width: 8
 145  * indent-tabs-mode: t
 146  * End:
 147  *
 148  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 149  * :indentSize=8:tabSize=8:noTabs=false:
 150  */