From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [PATCH] sit: correct IP protocol used in ipip6_err Date: Thu, 16 Jun 2016 17:10:11 +0900 Message-ID: <20160616081009.GA32730@vergenet.net> References: <1466064379-32355-1-git-send-email-simon.horman@netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: "David S. Miller" Return-path: Received: from mail-pa0-f51.google.com ([209.85.220.51]:32957 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750757AbcFPIKV (ORCPT ); Thu, 16 Jun 2016 04:10:21 -0400 Received: by mail-pa0-f51.google.com with SMTP id b13so15986117pat.0 for ; Thu, 16 Jun 2016 01:10:20 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1466064379-32355-1-git-send-email-simon.horman@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jun 16, 2016 at 05:06:19PM +0900, Simon Horman wrote: > Since 32b8a8e59c9c ("sit: add IPv4 over IPv4 support") > ipip6_err() may be called for packets whose IP protocol is > IPPROTO_IPIP as well as those whose IP protocol is IPPROTO_IPV6. > > In the case of IPPROTO_IPIP packets the correct protocol value is not > passed to ipv4_update_pmtu() or ipv4_redirect(). > > This patch resolves this problem by using the IP protocol of the packet > rather than a hard-coded value. This appears to be consistent > with the usage of the protocol of a packet by icmp_socket_deliver() > the caller of ipip6_err(). > > I was able to exercise the redirect case by using a setup where an ICMP > redirect was received for the destination of the encapsulated packet. > However, it appears that although incorrect the protocol field is not used > in this case and thus no problem manifests. On inspection it does not > appear that a problem will manifest in the fragmentation needed/update pmtu > case either. > > In short I believe this is a cosmetic fix. None the less, the use of > IPPROTO_IPV6 seems wrong and confusing. > > Reviewed-by: Dinan Gunawardena > Signed-off-by: Simon Horman Apologies for not making this more obvious, this is a "net-next" patch. > --- > net/ipv6/sit.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c > index d9f2bd6ef72d..f4356bb13f4b 100644 > --- a/net/ipv6/sit.c > +++ b/net/ipv6/sit.c > @@ -560,13 +560,13 @@ static int ipip6_err(struct sk_buff *skb, u32 info) > > if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { > ipv4_update_pmtu(skb, dev_net(skb->dev), info, > - t->parms.link, 0, IPPROTO_IPV6, 0); > + t->parms.link, 0, iph->protocol, 0); > err = 0; > goto out; > } > if (type == ICMP_REDIRECT) { > ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, > - IPPROTO_IPV6, 0); > + iph->protocol, 0); > err = 0; > goto out; > } > -- > 2.1.4 >