netdev - Re: [PATCH] sctp: keep fragmentation point aligned to word size

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] [day] [month] [year] [list]

Message-ID: <20160318231104.GD3387@mrl.redhat.com>
Date:	Fri, 18 Mar 2016 20:11:04 -0300
From:	Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
To:	netdev@...r.kernel.org
Cc:	Neil Horman <nhorman@...driver.com>,
	Vlad Yasevich <vyasevich@...il.com>, linux-sctp@...r.kernel.org
Subject: Re: [PATCH] sctp: keep fragmentation point aligned to word size

On Fri, Mar 18, 2016 at 06:39:17PM -0300, Marcelo Ricardo Leitner wrote:
> If the user supply a different fragmentation point or if there is a
> network header that cause it to not be aligned, force it to be aligned.
> 
> Fragmentation point at a value that is not aligned is not optimal.  It
> causes extra padding to be used and has just no pros.
> 
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
> ---
>  include/net/sctp/sctp.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> index 835aa2ed987092634a4242314e9eabb51d1e4e35..f27d38113c7926783a9bf2863e14e963ed0ad5d6 100644
> --- a/include/net/sctp/sctp.h
> +++ b/include/net/sctp/sctp.h
> @@ -426,7 +426,7 @@ static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
>  	if (asoc->user_frag)
>  		frag = min_t(int, frag, asoc->user_frag);
>  
> -	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
> +	frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN) & ~3;

Will submit a v2 with a helper for this & ~3 thing