linux-kernel - Problem With LOCAL IN HOOK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <4c348ac20703060327t44450331la1be820bc146d308@mail.gmail.com>
Date:	Tue, 6 Mar 2007 16:57:11 +0530
From:	"Kanhu Rauta" <choiskanhu@...il.com>
To:	linux-net@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Problem With LOCAL IN HOOK

Hi list,

I am writing a simple loadable module which will a register a function
in NF_IP_LOCAL_IN hook .But observed  different behavior in 2.4 and
2.6 kernel.

a> in 2.4 kernel, my function gets the assembled packet (in case of
fragmentation).

static struct nf_hook_ops test_forwarder
= { { NULL, NULL }, callback_forwarder, PF_INET, NF_IP_LOCAL_IN,
NF_IP_PRI_FILTER };

This is working fine .i got the assembled packet in function
callback_forwarder(in case of fragmentation).

b> in 2.6 kernel, my function gets the un-assembled packets (in case
of fragmentation).

static struct nf_hook_ops test_forwarder = {
  .hook     = callback_forwarder,
  .owner    = THIS_MODULE,
  .pf       = PF_INET,
  .hooknum  = NF_IP_LOCAL_IN,
  .priority = NF_IP_PRI_FILTER, };

This is not working, because i got the unassembled packet here. though
udp length shows 1508.but i am getting only 1400 bytes of valid data,
rest 108 bytes are something garbage.that i cross check with ethereal.
(I prints in a for loop like skb-data+20 to skb->data[1528])

I am not able to understand the behavior and struggled to resolve this
issue for last 1 week .

Can anybody help me on this regard ?

Regards,
kanhu
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/