[lkml]   [2003]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subjectkernel: ipt_hook: happy cracking.
So I look in my syslogs, and I find a lot of:

Nov 6 14:36:37 turing-police kernel: ipt_hook: happy cracking.

messages. A quick grep finds it's ipv4/netfilter/iptable_filter.c:

/* root is playing with raw sockets. */
if ((*pskb)->len < sizeof(struct iphdr)
|| (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
if (net_ratelimit())
printk("ipt_hook: happy cracking.\n");
return NF_ACCEPT;

The only problem is that root wasn't doing any playing at the time. The real
culprit was an iptables filter with '-j REJECT'. (Yes, usually a '-j DROP' is
my preference, but I get SYN packets from some places on our net where sending
an RST is more polite than waiting for retransmits).

I admit not being positively clear on how this manages to trigger, as
I'm not sure who's supposed to set the ->len field on the new pskb
allocated by ipt_REJECT.c:send_reset() (AFAICT, ->ihl should be OK
after skb_copy_bits() gets called).

Hardly 'cracking' - but after yesterday's CVS scare, I had to double
check this code was in 2.4.18 too before my pulse came down.. :)

[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2005-03-22 13:58    [W:0.031 / U:0.192 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site