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## Omission in earlier rate-limit...

  Forum: The Linux Kernel Hackers' Guide
  Re: Can you block or ignore ICMP packets?
  Re: ICMP send rate limit / ignoring (Jukka Santala)
  Keywords: ICMP ping Internet echo flood
  Date: Thu, 15 May 1997 22:44:33 GMT
  From: Jukka Santala <e75644@uwasa.fi>

    Oops, what a mistake. I missed the fact that icmp_send()
    isn't actually used for replying to ICMP_ECHO_REQUEST's etc.
    so no matter how you change the table in question, none
    of the replies are going to be limited... so what you need
    to do is add a call to the check in question to icmp_reply()
    as well, which is something that can already be called real
    kernel hacking. Here's how I'm doing it; however...
    1) I haven't yet rebooted with this code... wish me luck ;)
    2) Am I missing something? ping -f and ping -l get mostly ignored
    Here's the bit of code, in icmp_reply() right at the beginning (after local varable definitions) :
      #ifndef CONFIG_NO_ICMP_LIMIT
              if(!xrlim_allow(icmp_param->icmph.type, skb->nh.iph->saddr))
                     return;
      #endif
    I'll let you know how my tests with the thing proceed ;)
    (Sorry for bad formatting, I managed to break my PPP thingy playing around with filedescriptors, it seems, and this remote lynx doesn't quite handle text-fields properly, it seems... :P)

Messages

1. Patch worked... by Jukka Santala