From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753478AbcCGTfL (ORCPT ); Mon, 7 Mar 2016 14:35:11 -0500 Received: from prod-mail-xrelay06.akamai.com ([96.6.114.98]:48374 "EHLO prod-mail-xrelay06.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753402AbcCGTfC (ORCPT ); Mon, 7 Mar 2016 14:35:02 -0500 X-Greylist: delayed 476 seconds by postgrey-1.27 at vger.kernel.org; Mon, 07 Mar 2016 14:35:01 EST Subject: Re: [PATCH] udp6: fix UDP/IPv6 encap resubmit path To: Bill Sommerfeld , "David S. Miller" References: <1457131641-79311-1-git-send-email-wsommerfeld@google.com> Cc: Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Benjamin LaHaise , Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Josh Hunt Message-ID: <56DDD604.2080109@akamai.com> Date: Mon, 7 Mar 2016 13:27:00 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <1457131641-79311-1-git-send-email-wsommerfeld@google.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/04/2016 04:47 PM, Bill Sommerfeld wrote: > IPv4 interprets a negative return value from a protocol handler as a > request to redispatch to a new protocol. In contrast, IPv6 interprets a > negative value as an error, and interprets a positive value as a request > for redispatch. > > UDP for IPv6 was unaware of this difference. Change __udp6_lib_rcv() to > return a positive value for redispatch. Note that the socket's > encap_rcv hook still needs to return a negative value to request > dispatch, and in the case of IPv6 packets, adjust IP6CB(skb)->nhoff to > identify the byte containing the next protocol. > > Signed-off-by: Bill Sommerfeld > --- > net/ipv6/udp.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c > index 0711f8f..fd25e44 100644 > --- a/net/ipv6/udp.c > +++ b/net/ipv6/udp.c > @@ -922,11 +922,9 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, > ret = udpv6_queue_rcv_skb(sk, skb); > sock_put(sk); > > - /* a return value > 0 means to resubmit the input, but > - * it wants the return to be -protocol, or 0 > - */ > + /* a return value > 0 means to resubmit the input */ > if (ret > 0) > - return -ret; > + return ret; > > return 0; > } > This looks good to me. Thanks Bill! Josh