From 093d04d42fa094f6740bb188f0ad0c215ff61e2c Mon Sep 17 00:00:00 2001 From: Duan Jiong Date: Fri, 14 Dec 2012 02:59:59 +0000 Subject: [PATCH] ipv6: Change skb->data before using icmpv6_notify() to propagate redirect In function ndisc_redirect_rcv(), the skb->data points to the transport header, but function icmpv6_notify() need the skb->data points to the inner IP packet. So before using icmpv6_notify() to propagate redirect, change skb->data to point the inner IP packet that triggered the sending of the Redirect, and introduce struct rd_msg to make it easy. Signed-off-by: Duan Jiong Signed-off-by: David S. Miller --- include/net/ndisc.h | 7 +++++++ net/ipv6/ndisc.c | 17 +++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/net/ndisc.h b/include/net/ndisc.h index 7af1ea893038..23b3a7c58783 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 f2a007b7bde3..6574175795df 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1314,6 +1314,12 @@ 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: @@ -1330,6 +1336,17 @@ static void ndisc_redirect_rcv(struct sk_buff *skb) return; } + if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) + 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); }