Wireshark mailing list archives

Re: How to extract a string


From: "Anders Broman" <a.broman () telia com>
Date: Fri, 4 Dec 2009 07:37:26 +0100

Hi,

From the picture below it looks like you are reading the length from offset

0x43 the bytes would then be; starting with the high lighted 0x06 which is
high lighted by

By proto_add_item with length 1.

06 05 44 72 61 6d 61 65 6e 67 00

Loc_name length would then be 0x0605 as you are reading two octets with
tvb_get_ntohs()

Then you are adding the “string”  0x05 44 .. as offset is just moved one
byte with a length of

0x0605 with proto_add_item probably causing a “malformed packets” as you are
trying to read

outside of the tvb.

 

Best regards

Anders

 

 

  _____  

Från: wireshark-dev-bounces () wireshark org
[mailto:wireshark-dev-bounces () wireshark org] För Rach, Darshan
Skickat: den 4 december 2009 04:58
Till: wireshark-dev () wireshark org
Ämne: [Wireshark-dev] How to extract a string

 

Hi,

 

How to extract a string from packet (of Hex values)?

I know the string length.

 



 

I tried doing the following. But I am still not able to find it.

 

guint16 loc_name_length =0;

 

/*Location Name Length*/

proto_tree_add_item(oqtp_tree, hf_loc_name_length, tvb, packet_field_offset,
1, FALSE);

loc_name_length = tvb_get_ntohs(tvb, packet_field_offset);

packet_field_offset += 1;

 

/*Location Name*/

proto_tree_add_item(oqtp_tree, hf_loc_name, tvb,
packet_field_offset,loc_name_length ,FALSE);

packet_field_offset = packet_field_offset + loc_name_length + 1;

 

Any help on this would be appreciated.

 

Regards,

Darshan

 

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