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linuxippacket

How to captuare an IP packet, change its content and resend it on Linux?

My question is:

How to captuare an incoming IP packet from a network interface, change its content and resend it from another network interface?

Solution

  • The choice is yours, there is no preference (and hence no "normal").

    • using libnetfilter_queue to deliver to userspace and do extensive modification there.
    • or an xtables module, also works (since it's called by NF anyway). Allows for sufficient fine-grained configuration with help from userspace.
    • nfhook module, if you must. All configuration you must implement yourself.
    • well and finally, if you like things that hurt, you might as well implement your own virtual NIC driver.