netdev - Re: i386 vs x86_64 struct tpacket

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

Message-ID: <52B4B52C.3030903@aimvalley.nl>
Date:	Fri, 20 Dec 2013 22:22:52 +0100
From:	Norbert van Bolhuis <nvbolhuis@...valley.nl>
To:	Daniel Borkmann <dborkman@...hat.com>
CC:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: i386 vs x86_64 struct tpacket_hdr layout

On 12/20/13 19:45, Daniel Borkmann wrote:
> On 12/20/2013 07:38 PM, David Miller wrote:
>> From: Norbert van Bolhuis <nvbolhuis@...valley.nl>
>> Date: Fri, 20 Dec 2013 14:30:06 +0100
>>
>>>
>>> I'm compiling my 32bit application with -m32 on a x86_64
>>> system/kernel.
>>>
>>> Things aren't working because for my application tp_len is at offset 4
>>> but for the kernel it is at offset 8.
>>>
>>> struct tpacket_hdr {
>>> unsigned long tp_status;
>>> unsigned int tp_len;
>>> unsigned int tp_snaplen;
>>> unsigned short tp_mac;
>>> unsigned short tp_net;
>>> unsigned int tp_sec;
>>> unsigned int tp_usec;
>>> };
>>>
>>> How is this suppose to work ?
>>
>> This is why you should use tpacket layout v2 or v3, rather than v1,
>> they fix these issues.
>
> Norbert, please also read Documentation/networking/packet_mmap.txt
>
> Thanks !


Ah... thanks guys, now I see. struct tpacket2_hdr has fixed layout. I will use v2 (or v3).

I could not find this info in [linux-3.6.8/]Documentation/networking/packet_mmap.txt
though.

---
Norbert.





--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html