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

["khushbu thakkar" <thakkar.khushbu@xxxxxxxxx>]

Hi Jaap,

 

After a long R&D i could fix the problem of crashing. And the reason was too silly. The protocol handle was not maintained i.e "static" was missing in "proto_reg_handoff_ipt_spy" for dissector handle.

 

Anyways one new thing i could observed with Wireshark version 0.99.7 is that it does not show(was showing in Wireshark version 0.99.6) the name of the protocol (IPTWP in my case(UDP based)) in Protocol Column and Info column  but its shows UDP. It shows the dissection of IPTWP properly but not the Packet list pane.

 

Could u please guide me what specifically needs to be changed implementationally or some configuration,if its missing. I have attached the screenshot for the same issue which shows the middle pane properly but packet list pane wrongly.

 

Please look on to the issue.

 

Thank You,

Reply Soon.

Khushbu

 

On 12/22/07, khushbu thakkar <thakkar.khushbu@xxxxxxxxx> wrote:

Hi Jaap,

 

   I tried with your suggestion but still the tool crash with the same sequence. But when i tried applying the same preference code to packet-udp.c and tried to build wireshark, then it worked fine on Applying the preference from udp. So i doubt that the problem is there while Registering the Preference with Plugin, it works fine with \epan\dissectors.

 

Would you please guide what else can be done. Actually my requirement is to read external .xml file path/location to decode some part within my plugin packet. So how can that file path/location can be read. At present i m setting an enviornment variable and reading it but i m searching if some setting could be  given in Wireshark itself to read the file path/location.

 

Reply soon,

Thank You,

Khushbu

 

 

On 12/17/07, Jaap Keuter <jaap.keuter@xxxxxxxxx > wrote:

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
>      >
>
>     _______________________________________________
>     Wireshark-dev mailing list
>     Wireshark-dev@xxxxxxxxxxxxx <mailto: Wireshark-dev@xxxxxxxxxxxxx>
>     http://www.wireshark.org/mailman/listinfo/wireshark-dev
>
>
>
> ------------------------------------------------------------------------
>
>
> /* 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);
>       */
>
>
> }
>
>

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