From mboxrd@z Thu Jan  1 00:00:00 1970
From: chetan loke <loke.chetan@gmail.com>
Subject: Re: [af-packet 1/2] Enhance af-packet to provide (near zero)lossless
 packet capture functionality.
Date: Wed, 8 Jun 2011 18:10:02 -0400
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To: Eric Dumazet <eric.dumazet@gmail.com>
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On Wed, Jun 8, 2011 at 12:35 AM, Eric Dumazet <eric.dumazet@gmail.com> =
wrote:
> Le mardi 07 juin 2011 =C3=A0 23:13 -0400, Chetan Loke a =C3=A9crit :
>>
>> +struct tpacket3_hdr {
>> + =C2=A0 =C2=A0 __u32 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_status;
>> + =C2=A0 =C2=A0 __u32 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_len;
>> + =C2=A0 =C2=A0 __u32 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_snaplen;
>> + =C2=A0 =C2=A0 __u16 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_mac;
>> + =C2=A0 =C2=A0 __u16 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_net;
>
>> + =C2=A0 =C2=A0 __u32 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_sec;
>> + =C2=A0 =C2=A0 __u32 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_nsec;
>> + =C2=A0 =C2=A0 __u16 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 tp_vlan_tci=
;
>
> missing "__u16 tp_padding;" here
>
> check :
>
> http://git2.kernel.org/?p=3Dlinux/kernel/git/davem/net-2.6.git;a=3Dco=
mmit;h=3D13fcb7bd322164c67926ffe272846d4860196dc6


Eric, thanks for pointing that. I will add the padding. But just out
of curiosity, how is the information being leaked in tpacket_rcv()?

If someone is capturing packets then they have access to all the data
anyways. Also, tpacket_rcv doesn't memset the frame-element to 'zero'
before calling
skb_copy_bits(). And we would never want to memset anyways.

thnx
Chetan Loke