I used pcap4j to manipulate pcap files in java. Unfortunately, pcap4j can fix all checksums except frame check sequence(FCS). I want to send pcaps using tcpreplay. I am looking for a tool, library or package that can resolve FCS of every packet in a pcap file.
I expected pcap4j, tcpreplay or network card interface solve my problem at first, but i'm disappointed from them at all.
I couldn't find any tool after many search for this simple purpose, all I could do was using PureJavaCrc32 to calculate Ethernet FCS. But I'm not happy with this solution. because I guess it's not enough to just calculate Ethernet FCS, I think there is differences in FCS calculation between Ethernet and other layer 2 protocols which I like to support. I hoped I could use tshark because it is calculating FCS in wireshark, even I tried to review wireshark code see if I could make a tool for this purpose or not, but it was too complicated. So any advise?
I am looking for a tool, library or package that can resolve FCS of every packet in a pcap file.
If you're trying to replay a capture file, you probably do not need to fix the FCS. Normally, when a packet is transmitted, the network adapter computes a correct FCS and adds that to the packet; the host computer doesn't provide an FCS to the adapter, even if you're using a program such as tcpreplay to do raw packet injection.
(Note also that not all capture files have layer 2 FCS values. Most of them don't, because either: