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  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]
Date:	Thu, 19 Jul 2007 13:08:26 +0400
From:	Evgeniy Polyakov <>
To:	vinay ravuri <>
Cc:	Stephen Hemminger <>,
Subject: Re: Socket Buffers and Memory Managment


On Wed, Jul 18, 2007 at 11:51:03PM -0700, vinay ravuri ( wrote:
> How about the following approach:
> I allocate an skb of 0 bytes and replace data element
> of skb struct (i.e. = addr_given_by_hw) when
> the h/w interrupts me with a packet.  I register for a
> destructor for this skb and when the kernel is ready
> to free the skb, I make sure that my free is invoked -
> Ofcourse this is assuming that their is a facility in
> linux socket buffers to be able to do destructors.  Is
> this approach a viable, if so, are any gottcha's?

It will not work, since kfree_skb() eventually tries to free skb->head
into kmem cache, so you will need to hack kfree_skb() not to try to
release that data at all. Likely the best zero-copy approach in your
case is to use frag_list, but be ready that your netwrok will regularily
stall - when hardware buffers are all in use and not yet freed, you will
not be able to send/receive new packets, although amount of memory will
allow that.

> -Vinay

	Evgeniy Polyakov
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists