netdev - Re: [PATCH net] tcp: zero retrans_stamp if all retrans were acked

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]

Date:	Tue, 4 Nov 2014 13:51:31 -0500
From:	Neal Cardwell <ncardwell@...gle.com>
To:	Marcelo Ricardo Leitner <mleitner@...hat.com>
Cc:	Netdev <netdev@...r.kernel.org>, Yuchung Cheng <ycheng@...gle.com>,
	Eric Dumazet <edumazet@...gle.com>
Subject: Re: [PATCH net] tcp: zero retrans_stamp if all retrans were acked

On Tue, Nov 4, 2014 at 9:18 AM, Marcelo Ricardo Leitner
<mleitner@...hat.com> wrote:
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index a12b455928e52211efdc6b471ef54de6218f5df0..65686efeaaf3c36706390d3bfd260fd1fb942b7f 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -2410,6 +2410,8 @@ static bool tcp_try_undo_recovery(struct sock *sk)
>                  * is ACKed. For Reno it is MUST to prevent false
>                  * fast retransmits (RFC2582). SACK TCP is safe. */
>                 tcp_moderate_cwnd(tp);
> +               if (!tcp_any_retrans_done(sk))
> +                       tp->retrans_stamp = 0;

I ran into a compilation error with this, since tcp_any_retrans_done()
is defined below this spot in the file.

I'd recommend moving the tcp_any_retrans_done() code and its preceding
block comment to just above the spot in tcp_input.c that says "/* Undo
procedures. */". That way it compiles.

In the meantime, Yuchung put together a nice packetdrill test case for
this, so I'll run it on that version of the patch.

neal
--
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