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I need to convert packets to byte format and decode it . How is it possible to convert packets captured using jnetpcap library to array[bytes] and vice-versa in Java?

user3823859
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1 Answers1

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PcapPacket class has the method public int transferStateAndDataTo(byte[] buffer) which will copy the contents of the packet to the byte array.
define the byte[] with size as packet.getTotalSize()

if you are looking for the payload

//opens an offline pcap file 
Pcap pcap = Pcap.openOffline(pcapIpFile, errbuf); 

//packet object
PcapPacket packet = new PcapPacket(JMemory.POINTER); 

Payload pl = new Payload();

pcap.nextEx(packet);       // retrieves the next packet from input loop thru until eof

if(packet.hasHeader(pl))  //this will check for and retrieve the payload
    pl.data()   // this will give you the data in the payload as a byte stream

for data in the different headers (ethernet/ip/tcp) there are other methods available with the implementation

jozef
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  • Thanks. But while decoding the byte array packets back to pcap packets , exception occured in IP4() protocol. Is it enough to do the conversion like this : PcapPacket packet = new PcapPacket(bytes) ? – user3823859 Dec 13 '14 at 05:30