From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH v2 net-next] sock: Reset dst when changing sk_mark via setsockopt Date: Wed, 7 Nov 2018 21:59:02 -0800 Message-ID: <7c92b652-3c55-c051-e25e-bbc79944796c@gmail.com> References: <20181108045552.GA24562@konacove.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: David Barmann , netdev@vger.kernel.org Return-path: Received: from mail-pg1-f193.google.com ([209.85.215.193]:39901 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725724AbeKHPcy (ORCPT ); Thu, 8 Nov 2018 10:32:54 -0500 Received: by mail-pg1-f193.google.com with SMTP id r9-v6so8388080pgv.6 for ; Wed, 07 Nov 2018 21:59:05 -0800 (PST) In-Reply-To: <20181108045552.GA24562@konacove.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 11/07/2018 08:55 PM, David Barmann wrote: > When setting the SO_MARK socket option, the dst needs to be reset so > that a new route lookup is performed. > > This fixes the case where an application wants to change routing by > setting a new sk_mark. If this is done after some packets have already > been sent, the dst is cached and has no effect. > > Signed-off-by: David Barmann > --- > net/core/sock.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/core/sock.c b/net/core/sock.c > index 7b304e454a38..c74b10be86cb 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -952,10 +952,12 @@ int sock_setsockopt(struct socket *sock, int level, int optname, > clear_bit(SOCK_PASSSEC, &sock->flags); > break; > case SO_MARK: > - if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) > + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) { > ret = -EPERM; > - else > + } else { > sk->sk_mark = val; > + sk_dst_reset(sk); There is no need to force a sk_dst_reset(sk) if sk_mark was not changed. I already gave you this feedback, please do not ignore it. Thanks.