How to validate a message in pcap? - parsing

I have a requirement to expand required tree in decoded parameters of pcap file and validate a message in it.
Example:
Open "Transmission Control Protocol" as shown in screenshot and and validate for the message "This is an ACK to the segment in frame: 278".
Need to develop an automation script in Java for validating messages in pcap files . Currently am using jnetpcap lib.
Appreciate your inputs!.

You can't, without protocol analysis by yourself. A pcap file doesn't include such massages.
The message "This is an ACK to the segment in frame: 278" was generated by wireshark after TCP session analysis by itself. Even the frame number 278 was assigned by wireshark. A pcap file only contains packets' data.

Related

import ip packet via hex dump

I have a hex dump generated using gdb. I have generated the dump that wireshark can understand using "od -Ax -tx1 -v". But when I open in the wireshark tool the packet doesn't get recognized properly. I think wireshark is trying to read the ethernet frame while the buffer has data from IP header. Is there a way to indicate wireshark to parse hexdump assuming fro IP header.
Have a look at text2pcap. There are 2 basic approaches you can take:
Add a dummy Ethernet header using the -e <l3pid> option, or
Set the encapsulation type of the converted pcap file to link-layer type LINKTYPE_RAW using the -l 101 option.

Is it possible to obtain file path from IPP headers?

I writeing printing web application which simulate printer behavior. It uses IPP protocol to receive document within printing request.
I can obtain some information about print job from IPP attribute code 0x42 in IPP headers:
filename - full file path (it's my aim) in case of Notepad++ and only filename if I print document from MS Word
user name - from OS
Can I obtain full file path from IPP independent from application? May be I can achieve this with additional request?
0x42 specifies just the value type - in this case it probably represents type nameWithoutLanguage.
Filename
Short answer: There is no standard way to obtain the file path from ipp headers.
Depending on the ipp client implementation (e.g. the windows printer driver) you might be able to use some other attributes. There are various options how a driver could submit a print job.
Jobs sent via the ipp operation PRINT_JOB (0x0002)
The file is being added as stream of bytes (formatted in a specific print-job-language like postscript or pdf) . Most implementations set the job attribute job-name to the name of the original filename or filepath.
Jobs sent via the ipp operation PRINT_URI (0x0003)
This method is rarely used but would provide a URI where the printer would have to load the file or data to print from. The URI includes a path.
Username
As for the username there is a standard ipp attribute available: requesting-user-name. It is the ipp clients (e.g. windows printer driver) responsibility to set the this value. RFC 2911 Section 3.2.1.1 Print-Job-Request says:
The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by
the client as described in section 8.3.

change trace log format in emqtt message broker

I am using emqtt message broker for mqtt.
I am not a erlang developer and has zero knowledge on that.
I have used this erlang based broker, because after searching many open source broker online and suggestions from people about the advantage of erlang based server.
Now i am kind of stuck with the out put of the emqttd_cli trace command.
Its not json type and if i use a perl parser to convert to json type i am getting delayed output.
I want to know, in which file i could change the trace log output format.
I looked on the trace code of the broker and found a file src/emqttd_protocol.erl. An exported function named trace/3 has the code that you need.
Second argument of this function, named Packet, has the information of receive & send data via broker. You can fetch required data from it and format according to how you want to print.
Edit : Sample modified code added
trace(recv, Packet, ProtoState) ->
PacketHeader = Packet#mqtt_packet.header,
HostInfo = esockd_net:format(ProtoState#proto_state.peername),
%% PacketInfo = {ClientId, Username, ClientIP, ClientPort, Payload, QoS, Retain}
PacketInfo = {ProtoState#proto_state.client_id, ProtoState#proto_state.username, lists:nth(1, HostInfo), lists:nth(3, HostInfo), Packet#mqtt_packet.payload, PacketHeader#mqtt_packet_header.qos, PacketHeader#mqtt_packet_header.retain},
?LOG(info, "Data Received ~s", [PacketInfo], ProtoState);

How to send text file to printer

As i read in some fingerprint manual we can send text file to the printer. Means we can write the program in the text editor and send the whole program as a text file to the printer using the communication program using some transfer commands.
for in my host there is a file called myfile.txt in D:/ with the fallowing data
10 PRPOS 200,200
20 DIR 3
30 ALIGN 5
40 PRIMAGE “GLOBE.1”
50 PRINTFEED
RUN
How can i send this file to printer and execute the instrucations to print the image.
Please give me some code reference.
There are several ways to do this from the command line. For example:
type foo.txt > lpt1:
Or
copy foo.txt lpt1:
Or
print foo.txt
Or
notepad /p foo.txt
If you need to do it programmatically, you can execute any of those commands using the system() function or CreateProcess().
If you're on an Intermec handheld and you're connected to a Bluetooth printer, you should be able to open a serial port to COM6 and send your file over. What programming language? There should be plenty of Serial Port communication code examples out there.
My experience with Intermec PM4i label printer was a roller coaster but know I have a working app.
I tried Windows printer pipeline through generictext driver. It does work from Notepad but with few corner cases.
Printing directly from Notepad works fine until I tried QRCODE image with a very long text line. Image did not print out. Made qrcode text a short few characters and same script worked fine.
INPUT OFF
NASC 1252
BF OFF
FT "Swiss 721 Bold BT",12,0,100
PP 50,500:PT "Text line goes here"
PP 400,400:AN 7:BARSET "QRCODE",1,1,7,2,4
PB "ABC123 aabbcc....very long text goes here...I mean about 200 chars or more"
PRINTFEED
It was like Notepad cut text to a right side border and command string was broken. I made a printing preferences A3-landscape and it accepted longer text but still was not enough for all use cases.
All printers have a physical max printing width but it should not be considered in a fingerprint/directprotocol script files. After all we are not printing this text as-is but submitting commands to the printer.
My solution was to create Java application which opens a raw TCP socket to 11.22.33.44:9100 address and writes text lines, lines terminated by NL(#10). Works fine. Another helper tool I did was Delphi app.exe to read IP address from Windows printer object. I can submit label printouts "directly" from Excel application.
End users edit Excel data rows and click PRINT LABELS button
vba macro parses a fingerprint template file with ${FIELD1} find-and-replace substitutes
file is written to %wintemp%/intermec_script.txt folder
call app.exe to read IP address of user chosen printer
call java app to submit intermec_script.txt to IP:PORT socket
I should create same socket submit app in Delphi to drop javavm dependency but this solution was faster for my use case. I am more familiar with Java than my Delphi skill level.

Wireshark doesn't distinguish ACSE and MMS PDUs

I am working with Message Manufacturing Specification (MMS) in wireshark. The tool is unable to dissect the ACSE layer. It doesn't show any error but it shows the ACSE data as a part of MMS i.e., after the presentation layer, MMS is displayed. Kindly assist if there is a way for wireshark to distinguish both the layers.
Thanks.
This question is from 2012, but in 2016 Wireshark 2.2.0 is able to dissect ACSE (Association Control Service Element) in MMS PDUs. To test it, you can download MMS sample capture data from the Wireshark website and open it in Wireshark. You will see dissected ACSE such as:
ISO 8650-1 OSI Association Control Service
aarq
Padding: 7
protocol-version: 80 (version1)
aSO-context-name: 1.0.9506.1.1 (iso.0.9506.1.1)
called-AP-title: ap-title-form2 (1)
called-AE-qualifier: aso-qualifier-form2 (1)
calling-AP-title: ap-title-form2 (1)
calling-AE-qualifier: aso-qualifier-form2 (1)
user-information: 1 item

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