From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: Re: [PATCH] ipv6: fix the bug when propagating Redirect Message Date: Tue, 11 Dec 2012 14:45:14 +0100 Message-ID: <20121211134514.GE18940@secunet.com> References: <5086B721.1090905@gmail.com> <20121024045410.GF27385@secunet.com> <50C72DEC.1000008@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, netdev@vger.kernel.org To: Duan Jiong Return-path: Received: from a.mx.secunet.com ([195.81.216.161]:34698 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752867Ab2LKNpV (ORCPT ); Tue, 11 Dec 2012 08:45:21 -0500 Content-Disposition: inline In-Reply-To: <50C72DEC.1000008@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Dec 11, 2012 at 08:58:20PM +0800, Duan Jiong wrote: > > Just like you said, i try to use ndisc_parse_options() to instead > of the loop, but i find the skb->data can't be changed in function > ndisc_parse_options() due to lack of arguments. So i think it is > better to continue to use the loop. How do you think this? > You can change the data pointer after ndisc_parse_options(). Something like the (untested) patch below should do it. include/net/ndisc.h | 7 +++++++ net/ipv6/ndisc.c | 20 ++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/net/ndisc.h b/include/net/ndisc.h index 980d263..c17bccd 100644 --- a/include/net/ndisc.h +++ b/include/net/ndisc.h @@ -78,6 +78,13 @@ struct ra_msg { __be32 retrans_timer; }; +struct rd_msg { + struct icmp6hdr icmph; + struct in6_addr target; + struct in6_addr dest; + __u8 opt[0]; +}; + struct nd_opt_hdr { __u8 nd_opt_type; __u8 nd_opt_len; diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 2edce30..9afd23f 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1333,6 +1333,12 @@ out: static void ndisc_redirect_rcv(struct sk_buff *skb) { + u8 *hdr; + struct ndisc_options ndopts; + struct rd_msg *msg = (struct rd_msg *) skb_transport_header(skb); + u32 ndoptlen = skb->tail - (skb->transport_header + + offsetof(struct rd_msg, opt)); + #ifdef CONFIG_IPV6_NDISC_NODETYPE switch (skb->ndisc_nodetype) { case NDISC_NODETYPE_HOST: @@ -1349,6 +1355,20 @@ static void ndisc_redirect_rcv(struct sk_buff *skb) return; } + if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { + ND_PRINTK(2, warn, "Redirect: invalid ND options\n"); + return; + } + + if (!ndopts.nd_opts_rh) + return; + + hdr = (u8 *) ndopts.nd_opts_rh; + hdr += 8; + + if (!pskb_pull(skb, hdr - skb_transport_header(skb))) + return; + icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); } -- 1.7.9.5