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Wireshark-dev: Re: [Wireshark-dev] crash with Preference in Plugin

From: Jaap Keuter <jaap.keuter@xxxxxxxxx>
Date: Mon, 17 Dec 2007 08:22:43 +0100
Hi,

Loose the ipt_config_preferencefile variable, just go with gbl_iptConfigDictionary. See packet-cigi.c where global_host_ip is handled similarly.

Thanx,
Jaap

khushbu thakkar wrote:
Hi Jaap,

           Thanx for the response. Attached is the part of plugin code.
Reply Soon,
Thank You,
Khushbu
On 12/15/07, *Jaap Keuter* <jaap.keuter@xxxxxxxxx <mailto:jaap.keuter@xxxxxxxxx>> wrote:

    Hi,

    If you could post at least your proto_register and proto_handoff code we
    might be able to get some insight.

    Thanx,
    Jaap

    khushbu thakkar wrote:
     > Hello,
     >
     >          I am not actually new to Wireshark, i have build the
    plugin in
     > Wireshark which has to be decoded on the top of UDP. I m using
    this on
     > Window XP SP1 . I have build Wireshark with GTK+ 2.10.12 and
    Wireshark
     > Version is 0.99.6.
     >
     >         The problem with me is *Wireshark Crash* when the
    "*Preference*"
     > of the my *plugin * is set. Whenever the preference value changes
    from
     > the initialized value and if we try to capture or load the
    recorded file
     > having packets of my plugin protocol it crashes. And one more
    thing is
     > if i disable the preference code n use the xxx.dll then it works
    fine
     > i.e. problem is due to preference code.
     >
     >           I m using the Standard code format for registering the
     > Preference as in Readme.developer. So anybody could please guide me
     > where should the problem actually be. Thank You in advance for
    the help.
     >
     > Reply Soon,
     > Best Regards,
     > Khushbu
     >

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------------------------------------------------------------------------


/* Global sample preference ("controls" display of numbers) */
static const char *gbl_iptConfigDictionary = NULL;
static char *ipt_config_preferencefile	   = NULL;

/* Register the protocol with Wireshark */
/* this format is require because a script is used to build the C function
   that calls all the protocol registration.
*/
void proto_register_ipt_spy(void)
{ module_t *ipt_spy_module;
/* Setup list of header fields  See Section 1.6.1 for details*/
	static hf_register_info hf[] = {
		{ &hf_ipt_spy_timestamp,
			{ "Time Stamp (microseconds)",           "iptwp.timestamp",
FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL }
		},
		{ &hf_ipt_spy_protocolversion,
			{ "Protocol Version",           "iptwp.protocolversion",
FT_UINT32, BASE_HEX, VALS(ipt_spy_protocol_ver_vals) , 0x0, "", HFILL }
		},
			.
			.
			.
			.
	/* Setup protocol subtree array */
	static gint *ett[] = {
		&ett_ipt_spy,
		&ett_ipt_spy_dscpfield,
		&ett_ipt_spy_app_data,
		&ett_ipt_spy_nestd_app_data,
		&ett_ipt_spy_app_data_booleanfield,
		&ett_ipt_spy_multiple_app_data,
		&ett_ipt_spy_app_data_fcs,
	};

	ipt_config_preferencefile = g_strdup("");
	gbl_iptConfigDictionary = g_strdup(ipt_config_preferencefile);

/* Register the protocol name and description */
	proto_ipt_spy = proto_register_protocol("IP Train Wire Protocol", "IPTWP", "iptwp");

	register_dissector("IPTWP", dissect_ipt_spy, proto_ipt_spy); /*By Cisco*/

/* Required function calls to register the header fields and subtrees used */
	proto_register_field_array(proto_ipt_spy, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett)); /* Register preferences module (See Section 2.6 for more on preferences) */ ipt_spy_module = prefs_register_protocol(proto_ipt_spy, proto_reg_handoff_ipt_spy);

/* Register a sample preference */
	prefs_register_string_preference(ipt_spy_module, "iptfile",
				    "IPT configuration file",
				    "IPT configuration file",
				    &gbl_iptConfigDictionary);

}


/* If this dissector uses sub-dissector registration add a registration routine.
This exact format is required because a script is used to find these routines and create the code that calls these routines. This function is also called by preferences whenever "Apply" is pressed (see prefs_register_protocol above) so it should accommodate being called more than once.
*/
void proto_reg_handoff_ipt_spy(void)
{
        static gboolean inited = FALSE;
		dissector_handle_t ipt_spy_handle;

		//g_free(ipt_config_pref);
		// current_asn1 = g_strdup(asn1_filename);
		//ipt_config_pref = g_strdup(gbl_iptConfigDictionary);
if(!inited ) {
			ipt_spy_handle = create_dissector_handle(dissect_ipt_spy, proto_ipt_spy);
			inited = TRUE;
		}
		else
		{
			dissector_delete("udp.port", ipt_spy_UDP_MD_PORT, ipt_spy_handle);
			dissector_delete("udp.port", ipt_spy_UDP_PD_PORT, ipt_spy_handle);
		}

		ipt_config_preferencefile = gbl_iptConfigDictionary;
		
		dissector_add("udp.port", ipt_spy_UDP_MD_PORT, ipt_spy_handle);
dissector_add("udp.port", ipt_spy_UDP_PD_PORT, ipt_spy_handle); /* If you perform registration functions which are dependant upon
          prefs the you should de-register everything which was associated
          with the previous settings and re-register using the new prefs settings
          here. In general this means you need to keep track of what value the
          preference had at the time you registered using a local static in this
          function. ie.
          static int currentPort = -1;
          if( -1 != currentPort ) {
              dissector_delete( "tcp.port", currentPort, ipt_spy_handle);
          }
          currentPort = gPortPref;
          dissector_add("tcp.port", currentPort, ipt_spy_handle);
      */
}