Wireshark · Wireshark-dev: Re: [Wireshark-dev] PFCP Trace information issue in WS 3.0.0 rc1

[Pascal Quantin <pascal@xxxxxxxxxxxxx>]

Hi Varun,

Le ven. 22 févr. 2019 à 17:09, Varun Goyal <varun.goyal@xxxxxxxxx> a écrit :

 HI ,

I have seen the code of WS of version 3.0.0 rc1 and found that WS is not able to decode the IE Trace information correctly.

Observation :

1. Trace info has parameter 

    uint32_t Traceid:24, 

    uint32_t spare;

WS does not decoded the spare value .

static void

  dissect_pfcp_trace_information(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree

  *tree, proto_item *item _U_, guint16 length _U_, guint8 message_type _U_, pfcp_

  session_args_t *args _U_){

/* 8 to 10   Trace ID */

      proto_tree_add_item(tree, hf_pfcp_trace_information_trace_id, tvb, offset, 3

  , ENC_BIG_ENDIAN);

      offset += 3;    ========offset+=4 should be there.

}

According to 3GPP 29.244, there is no 4th byte being a spare value between the Trace ID and Length of Trigger Events fields. The code seems correct.

2. IP_address 

proto_tree_add_item(tree, hf_pfcp_trace_information_ipaddress, tvb, offset, 

  length_ipaddress, ENC_NA);

      offset += length_ipaddress; Here also , offset += wrong value it should be fixed with length_ipaddress*sizeof(uint8_t)

Given that the size of a uint8_t is 1 byte, I'm not sure what you are trying to achieve here.  Again the existing code seems correct.

Best regards,

Pascal.