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SubjectRe: Ping with a 65510 bytes pack
I'd say there is a 99% chance that the user was jusr trying to crash you.
There is no other reason why someone would send out a 65510 byte packet :>

-Rob

On Sun, 20 Oct 1996, Jon Lewis wrote:

> This slightly modified version of Alan Cox's ping patch has been tested on
> my SMP test box. Without it, I can crash it from a Win95 box, and then
> softdog (I assume) reboots it. With the patch, Win95 doesn't seem able to
> crash it. I'm now running this patch on 5 other systems.
>
> Is there anything other than someone trying to crash my box that would
> trigger the printk I added? One of our servers just logged this:
>
> Oversized packet received from 205.229.51.6
>
> That's one of our dialup user IP addresses. Are my own users trying to
> crash me, or is it just a Windows IP bug? If there's no explanation other
> than someone trying to crash our mail server, I'd like to terminate that
> account.
>
> --- ip_fragment.c.orig Wed Aug 7 07:00:08 1996
> +++ ip_fragment.c Sat Oct 19 20:33:42 1996
> @@ -47,6 +47,8 @@
>
> atomic_t ip_frag_mem = 0; /* Memory used for fragments */
>
> +char *in_ntoa(unsigned long in);
> +
> /*
> * Memory Tracking Functions
> */
> @@ -366,7 +368,7 @@
> {
> NETDEBUG(printk("Invalid fragment list: Fragment over size.\n"));
> ip_free(qp);
> - frag_kfree_skb(skb,FREE_WRITE);
> + kfree_skb(skb,FREE_WRITE);
> ip_statistics.IpReasmFails++;
> return NULL;
> }
> @@ -466,6 +468,19 @@
> return NULL;
> }
> }
> +
> + /*
> + * Attempt to construct an oversize packet.
> + */
> +
> + if(ntohs(iph->tot_len)+(int)offset>65535)
> + {
> + skb->sk = NULL;
> + printk("Oversized packet received from %s\n",in_ntoa(qp->iph->saddr));
> + frag_kfree_skb(skb, FREE_READ);
> + ip_statistics.IpReasmFails++;
> + return NULL;
> + }
>
> /*
> * Determine the position of this fragment.
>
>
>
> ------------------------------------------------------------------
> Jon Lewis <jlewis@fdt.net> | Unsolicited commercial e-mail will
> Network Administrator | be proof-read for $199/hr.
> ________Finger jlewis@inorganic5.fdt.net for PGP public key_______
>
>
>


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