pcapdj

pcapdj - dispatch pcap filesNetwork captures often result in very large files. Therefore, tools like tcpdump or dumpcap offer features of file rotation either after a fixed size or a fixed amount of time.When these files are analyzed focusing on stateful protocols such as TCP, TCP sessions could have been established in one pcap file and continue in the next pcap files. When these TCP sessions have to be properly reassembled, then either the TCP reassembly tool has to support multiple pcap files as input or the pcap files have to merged in a single file using for instance a tool such as editcap. However, in this case, very large files are the results, that were tried to be avoided with the file rotation.PCAPDJ processes a list of pcap files and write each individual packet in a named pipe. A second process reads these individual packets and does some processing. A third process, does some cleanup operations and controls pcapdj.Each pcap file that is processed by pcapdj must be authorized by a third process. When a pcap file is not acknowledged the file descriptor to the named pipe is not closed and hence the other program processing pcap data does not end and keeps its internal states. Before a next file is authorized, other tasks could be done, such as removing duplicated files or already processed pcap files in order to free disk space.