Legacy Pcap parsing & writing

A modified version of courvoif/pcap-file that supports only the old legacy pcap file format (.pcap extension).

The PCAP format is very simple. see here for a description of its structure. This crate provides some abstractions over it for reading and writing, including streaming variants. It is also non-async.

This crate has no external dependencies (apart from std). It has also no unsafe code.

All abstractions use the standard library Read and Write traits.

Examples

Reading data the easy way:

    use legacy_pcap_file::PcapReader;

    // Let's assume this is some pcap data. It can also be a file.
    // Anything implementing `Read`.
    let some_buffer = vec![];
    let pcap_reader = PcapReader::new(&some_buffer).unwrap();

    // Packets can be iterated on.
    for res in pcap_reader {
        // For each packet we get a result, since there are a few errors that
        // can pop up:
        // * The data source can be exhausted mid packet.
        // * The packet header length may be shorter than actual data length. 
        let pkt = res.unwrap();
        // Use the packet.
        ...
    }

Reading data while reusing the packet buffer. (This is a bit of a hack).

    use legacy_pcap_file::PcapReader;

    // Let's assume this is some pcap data. It can also be a file.
    // Anything implementing `Read`.
    let some_buffer = vec![];
    let pcap_reader = PcapReader::new(&some_buffer).unwrap();

    // Define some backing data for the packets payload.
    let mut backing_data = vec![]; 
    // Iterate manually.
    while let Some(Ok(pkt)) = pcap_reader.next_with(backing_data) {
        // here you can use the packet, clone it, etc..
        ...
        // reuse the data.
        backing_data = pkt.data;
    }

Writing data:

    use legacy_pcap_file::{PcapHeader, PcapPacket, PcapFileWriter};

    // Let's say you have a pcap header defined
    let header: PcapHeader = ...
    // and some supply of packets
    let packets: Vec<PcapPacket> = ...
    // They can be written like so
    let path = Path::from("/some/file/path");
    let mut pcap_file_writer = PcapFileWriter::new_with_header(&path, header).unwrap();
    for packet in packets {
        // Some errors that can occur:
        // * The backing storage maybe error in some way (IO error).
        // * The packets are not well formed (mostly declared payload length 
        //   does not match real length).
        pcap_file_writer.write_packet(&packet).unwrap();
    }
    pcap_file_writer.close().unwrap();

License

Licensed under MIT/Apache-2.0 license.