clinuxtcpraw-sockets

Is there an option or command that I can used to disable/unload/ or stop the tcp/IP stack in linux. Need it to implement user space tcp in server app


I am working a C program that is uses sockets to implement tcp networking in a server application that I am working on. I was wondering is it possible to disable the tcp/ip stack of the kernel so my system do not interfere with incoming connection sync requests and IP packets.

Or I must compile kernel to disable it please tell if this is the case.

On this question How to create a custom packet in c?

it says

Also note that if you are trying to send raw tcp/udp packets, one problem you will have is disabling the network stack automatically processing the reply (either by treating it as addressed to an existing IP address or attempting to forward it).

If thats the case then how can it be possible.

Or is there any tool or program in Linux that can be used to achieve this like this comment Disable TCP/IP Stack from user-space

There is of course the counterintuitive approach of using additional networking functionality to disable normal networking functionality: netfilter. There are a few iptables matches/targets which might prove beneficial to you (e.g., the “owner” match that may deny or accept based on PID or UID). This still means the functionality is in the kernel, it just limits it.

if someone knows from right above then how can this be done are there any commands?


Solution

  • Well, you could compile yourself a kernel without networking :)

    A couple of options

    1. Check out the DPDK project (https://www.linuxjournal.com/content/userspace-networking-dpdk). DPDK passes the Physical NIC to User space via UIO driver to igb_uio|uio_pci_generic|vfio-pci. Thus eliminates Kernel Stack.
    2. Use XDP supported NIC with either Zero-Copy or Driver-mode. with eBPF running one can push the received packets directly to User space bypassing the kernel stack.

    Unless this is a homework project, remember: don't invent, reuse.

    [EDIT-based on comment] Userspace TCP-IP stack have custom sock-API to read/write into the socket. So with either LD_PRELOAD or source file change, one can use the same application.