From 1de9243bbfc451962ab716a3f7a7fda26d91c359 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 18:32:17 -0700
Subject: [PATCH 01/16] ipv4: Pull icmp socket delivery out into a helper
 function.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/icmp.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 4a049449305f..18e39d1895d4 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -634,18 +634,31 @@ out:;
 EXPORT_SYMBOL(icmp_send);
 
 
+static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
+{
+	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	const struct net_protocol *ipprot;
+	int protocol = iph->protocol;
+
+	raw_icmp_error(skb, protocol, info);
+
+	rcu_read_lock();
+	ipprot = rcu_dereference(inet_protos[protocol]);
+	if (ipprot && ipprot->err_handler)
+		ipprot->err_handler(skb, info);
+	rcu_read_unlock();
+}
+
 /*
  *	Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
  */
 
 static void icmp_unreach(struct sk_buff *skb)
 {
-	const struct net_protocol *ipprot;
 	const struct iphdr *iph;
 	struct icmphdr *icmph;
 	struct net *net;
 	u32 info = 0;
-	int protocol;
 
 	net = dev_net(skb_dst(skb)->dev);
 
@@ -726,19 +739,7 @@ static void icmp_unreach(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
 		goto out;
 
-	iph = (const struct iphdr *)skb->data;
-	protocol = iph->protocol;
-
-	/*
-	 *	Deliver ICMP message to raw sockets. Pretty useless feature?
-	 */
-	raw_icmp_error(skb, protocol, info);
-
-	rcu_read_lock();
-	ipprot = rcu_dereference(inet_protos[protocol]);
-	if (ipprot && ipprot->err_handler)
-		ipprot->err_handler(skb, info);
-	rcu_read_unlock();
+	icmp_socket_deliver(skb, info);
 
 out:
 	return;

From d3351b75a7169337877fe6f6f2c019154b6ec1ea Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 18:35:12 -0700
Subject: [PATCH 02/16] ipv4: Deliver ICMP redirects to sockets too.

And thus, we can remove the ping_err() hack.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/icmp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 18e39d1895d4..588514627aa7 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -782,13 +782,7 @@ static void icmp_redirect(struct sk_buff *skb)
 		break;
 	}
 
-	/* Ping wants to see redirects.
-         * Let's pretend they are errors of sorts... */
-	if (iph->protocol == IPPROTO_ICMP &&
-	    iph->ihl >= 5 &&
-	    pskb_may_pull(skb, (iph->ihl<<2)+8)) {
-		ping_err(skb, icmp_hdr(skb)->un.gateway);
-	}
+	icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
 
 out:
 	return;

From d0da720f9f16a5023cc084bed8968702400f6e0f Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 20:27:54 -0700
Subject: [PATCH 03/16] ipv4: Pull redirect instantiation out into a helper
 function.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/route.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 95bfa1ba5b28..a4de87f44c30 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1271,6 +1271,26 @@ static void rt_del(unsigned int hash, struct rtable *rt)
 	spin_unlock_bh(rt_hash_lock_addr(hash));
 }
 
+static void ip_do_redirect(struct rtable *rt, __be32 old_gw, __be32 new_gw)
+{
+	struct neighbour *n;
+
+	if (rt->rt_gateway != old_gw)
+		return;
+
+	n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
+	if (n) {
+		if (!(n->nud_state & NUD_VALID)) {
+			neigh_event_send(n, NULL);
+		} else {
+			rt->rt_gateway = new_gw;
+			rt->rt_flags |= RTCF_REDIRECTED;
+			call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
+		}
+		neigh_release(n);
+	}
+}
+
 /* called in rcu_read_lock() section */
 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 		    __be32 saddr, struct net_device *dev)
@@ -1311,8 +1331,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 			rthp = &rt_hash_table[hash].chain;
 
 			while ((rt = rcu_dereference(*rthp)) != NULL) {
-				struct neighbour *n;
-
 				rthp = &rt->dst.rt_next;
 
 				if (rt->rt_key_dst != daddr ||
@@ -1322,21 +1340,10 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 				    rt_is_expired(rt) ||
 				    !net_eq(dev_net(rt->dst.dev), net) ||
 				    rt->dst.error ||
-				    rt->dst.dev != dev ||
-				    rt->rt_gateway != old_gw)
+				    rt->dst.dev != dev)
 					continue;
 
-				n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
-				if (n) {
-					if (!(n->nud_state & NUD_VALID)) {
-						neigh_event_send(n, NULL);
-					} else {
-						rt->rt_gateway = new_gw;
-						rt->rt_flags |= RTCF_REDIRECTED;
-						call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
-					}
-					neigh_release(n);
-				}
+				ip_do_redirect(rt, old_gw, new_gw);
 			}
 		}
 	}

From 94206125c4aac32e43c25bfe1b827e7ab993b7dc Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 20:38:08 -0700
Subject: [PATCH 04/16] ipv4: Rearrange arguments to ip_rt_redirect()

Pass in the SKB rather than just the IP addresses, so that policy
and other aspects can reside in ip_rt_redirect() rather then
icmp_redirect().

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/route.h |  3 +--
 net/ipv4/icmp.c     | 38 +++++++-------------------------------
 net/ipv4/route.c    | 23 +++++++++++++++++++----
 3 files changed, 27 insertions(+), 37 deletions(-)

diff --git a/include/net/route.h b/include/net/route.h
index 52362368af09..b1402787aecb 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -108,8 +108,7 @@ extern struct ip_rt_acct __percpu *ip_rt_acct;
 
 struct in_device;
 extern int		ip_rt_init(void);
-extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
-				       __be32 src, struct net_device *dev);
+extern void		ip_rt_redirect(struct sk_buff *skb, __be32 new_gw);
 extern void		rt_cache_flush(struct net *net, int how);
 extern void		rt_cache_flush_batch(struct net *net);
 extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 588514627aa7..70a793559bb5 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -755,40 +755,16 @@ static void icmp_unreach(struct sk_buff *skb)
 
 static void icmp_redirect(struct sk_buff *skb)
 {
-	const struct iphdr *iph;
-
-	if (skb->len < sizeof(struct iphdr))
-		goto out_err;
-
-	/*
-	 *	Get the copied header of the packet that caused the redirect
-	 */
-	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
-		goto out;
-
-	iph = (const struct iphdr *)skb->data;
-
-	switch (icmp_hdr(skb)->code & 7) {
-	case ICMP_REDIR_NET:
-	case ICMP_REDIR_NETTOS:
-		/*
-		 * As per RFC recommendations now handle it as a host redirect.
-		 */
-	case ICMP_REDIR_HOST:
-	case ICMP_REDIR_HOSTTOS:
-		ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr,
-			       icmp_hdr(skb)->un.gateway,
-			       iph->saddr, skb->dev);
-		break;
+	if (skb->len < sizeof(struct iphdr)) {
+		ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS);
+		return;
 	}
 
-	icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		return;
 
-out:
-	return;
-out_err:
-	ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS);
-	goto out;
+	ip_rt_redirect(skb, icmp_hdr(skb)->un.gateway);
+	icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
 }
 
 /*
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index a4de87f44c30..f8921b448c39 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1292,18 +1292,33 @@ static void ip_do_redirect(struct rtable *rt, __be32 old_gw, __be32 new_gw)
 }
 
 /* called in rcu_read_lock() section */
-void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
-		    __be32 saddr, struct net_device *dev)
+void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
 {
-	int s, i;
+	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	__be32 old_gw = ip_hdr(skb)->saddr;
+	__be32 daddr = iph->daddr;
+	__be32 saddr = iph->saddr;
+	struct net_device *dev = skb->dev;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
-	__be32 skeys[2] = { saddr, 0 };
 	int    ikeys[2] = { dev->ifindex, 0 };
+	__be32 skeys[2] = { saddr, 0 };
 	struct net *net;
+	int s, i;
 
 	if (!in_dev)
 		return;
 
+	switch (icmp_hdr(skb)->code & 7) {
+	case ICMP_REDIR_NET:
+	case ICMP_REDIR_NETTOS:
+	case ICMP_REDIR_HOST:
+	case ICMP_REDIR_HOSTTOS:
+		break;
+
+	default:
+		return;
+	}
+
 	net = dev_net(dev);
 	if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
 	    ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||

From e47a185b31dd2acd424fac7dc0efb96fc5b31a33 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 20:55:47 -0700
Subject: [PATCH 05/16] ipv4: Generalize ip_do_redirect() and hook into new
 dst_ops->redirect.

All of the redirect acceptance policy is now contained within.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/dst_ops.h |  1 +
 net/ipv4/route.c      | 94 +++++++++++++++++++++++++------------------
 2 files changed, 55 insertions(+), 40 deletions(-)

diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h
index 4badc86e45d1..085931fa7ce0 100644
--- a/include/net/dst_ops.h
+++ b/include/net/dst_ops.h
@@ -25,6 +25,7 @@ struct dst_ops {
 	struct dst_entry *	(*negative_advice)(struct dst_entry *);
 	void			(*link_failure)(struct sk_buff *);
 	void			(*update_pmtu)(struct dst_entry *dst, u32 mtu);
+	void			(*redirect)(struct dst_entry *dst, struct sk_buff *skb);
 	int			(*local_out)(struct sk_buff *skb);
 	struct neighbour *	(*neigh_lookup)(const struct dst_entry *dst,
 						struct sk_buff *skb,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f8921b448c39..f3d25656ddb0 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -149,6 +149,7 @@ static void		 ipv4_dst_destroy(struct dst_entry *dst);
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 static void		 ipv4_link_failure(struct sk_buff *skb);
 static void		 ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
+static void		 ip_do_redirect(struct dst_entry *dst, struct sk_buff *skb);
 static int rt_garbage_collect(struct dst_ops *ops);
 
 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
@@ -179,6 +180,7 @@ static struct dst_ops ipv4_dst_ops = {
 	.negative_advice =	ipv4_negative_advice,
 	.link_failure =		ipv4_link_failure,
 	.update_pmtu =		ip_rt_update_pmtu,
+	.redirect =		ip_do_redirect,
 	.local_out =		__ip_local_out,
 	.neigh_lookup =		ipv4_neigh_lookup,
 };
@@ -1271,42 +1273,18 @@ static void rt_del(unsigned int hash, struct rtable *rt)
 	spin_unlock_bh(rt_hash_lock_addr(hash));
 }
 
-static void ip_do_redirect(struct rtable *rt, __be32 old_gw, __be32 new_gw)
-{
-	struct neighbour *n;
-
-	if (rt->rt_gateway != old_gw)
-		return;
-
-	n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
-	if (n) {
-		if (!(n->nud_state & NUD_VALID)) {
-			neigh_event_send(n, NULL);
-		} else {
-			rt->rt_gateway = new_gw;
-			rt->rt_flags |= RTCF_REDIRECTED;
-			call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
-		}
-		neigh_release(n);
-	}
-}
-
-/* called in rcu_read_lock() section */
-void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
+static void ip_do_redirect(struct dst_entry *dst, struct sk_buff *skb)
 {
 	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	__be32 new_gw = icmp_hdr(skb)->un.gateway;
 	__be32 old_gw = ip_hdr(skb)->saddr;
+	struct net_device *dev = skb->dev;
 	__be32 daddr = iph->daddr;
 	__be32 saddr = iph->saddr;
-	struct net_device *dev = skb->dev;
-	struct in_device *in_dev = __in_dev_get_rcu(dev);
-	int    ikeys[2] = { dev->ifindex, 0 };
-	__be32 skeys[2] = { saddr, 0 };
+	struct in_device *in_dev;
+	struct neighbour *n;
+	struct rtable *rt;
 	struct net *net;
-	int s, i;
-
-	if (!in_dev)
-		return;
 
 	switch (icmp_hdr(skb)->code & 7) {
 	case ICMP_REDIR_NET:
@@ -1319,6 +1297,14 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
 		return;
 	}
 
+	rt = (struct rtable *) dst;
+	if (rt->rt_gateway != old_gw)
+		return;
+
+	in_dev = __in_dev_get_rcu(dev);
+	if (!in_dev)
+		return;
+
 	net = dev_net(dev);
 	if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
 	    ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
@@ -1335,6 +1321,43 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
 			goto reject_redirect;
 	}
 
+	n = ipv4_neigh_lookup(dst, NULL, &new_gw);
+	if (n) {
+		if (!(n->nud_state & NUD_VALID)) {
+			neigh_event_send(n, NULL);
+		} else {
+			rt->rt_gateway = new_gw;
+			rt->rt_flags |= RTCF_REDIRECTED;
+			call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
+		}
+		neigh_release(n);
+	}
+	return;
+
+reject_redirect:
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+	if (IN_DEV_LOG_MARTIANS(in_dev))
+		net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
+				     "  Advised path = %pI4 -> %pI4\n",
+				     &old_gw, dev->name, &new_gw,
+				     &saddr, &daddr);
+#endif
+	;
+}
+
+/* called in rcu_read_lock() section */
+void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
+{
+	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	__be32 daddr = iph->daddr;
+	__be32 saddr = iph->saddr;
+	struct net_device *dev = skb->dev;
+	int    ikeys[2] = { dev->ifindex, 0 };
+	__be32 skeys[2] = { saddr, 0 };
+	struct net *net;
+	int s, i;
+
+	net = dev_net(dev);
 	for (s = 0; s < 2; s++) {
 		for (i = 0; i < 2; i++) {
 			unsigned int hash;
@@ -1358,21 +1381,12 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
 				    rt->dst.dev != dev)
 					continue;
 
-				ip_do_redirect(rt, old_gw, new_gw);
+				ip_do_redirect(&rt->dst, skb);
 			}
 		}
 	}
 	return;
 
-reject_redirect:
-#ifdef CONFIG_IP_ROUTE_VERBOSE
-	if (IN_DEV_LOG_MARTIANS(in_dev))
-		net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
-				     "  Advised path = %pI4 -> %pI4\n",
-				     &old_gw, dev->name, &new_gw,
-				     &saddr, &daddr);
-#endif
-	;
 }
 
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)

From b42597e2f36e2043756aa7462faddf630962f061 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 21:25:45 -0700
Subject: [PATCH 06/16] ipv4: Add ipv4_redirect() and ipv4_sk_redirect() helper
 functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/route.h |  3 +++
 net/ipv4/route.c    | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/net/route.h b/include/net/route.h
index b1402787aecb..6ab93eeb8660 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -180,6 +180,9 @@ static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 s
 extern void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
 			     int oif, u32 mark, u8 protocol, int flow_flags);
 extern void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
+extern void ipv4_redirect(struct sk_buff *skb, struct net *net,
+			  int oif, u32 mark, u8 protocol, int flow_flags);
+extern void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
 extern void ip_rt_send_redirect(struct sk_buff *skb);
 
 extern unsigned int		inet_addr_type(struct net *net, __be32 addr);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f3d25656ddb0..aabece6b729a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1590,6 +1590,34 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 }
 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
 
+void ipv4_redirect(struct sk_buff *skb, struct net *net,
+		   int oif, u32 mark, u8 protocol, int flow_flags)
+{
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
+	struct flowi4 fl4;
+	struct rtable *rt;
+
+	flowi4_init_output(&fl4, oif, mark, RT_TOS(iph->tos), RT_SCOPE_UNIVERSE,
+			   protocol, flow_flags, iph->daddr, iph->saddr, 0, 0);
+	rt = __ip_route_output_key(net, &fl4);
+	if (!IS_ERR(rt)) {
+		ip_do_redirect(&rt->dst, skb);
+		ip_rt_put(rt);
+	}
+}
+EXPORT_SYMBOL_GPL(ipv4_redirect);
+
+void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+
+	return ipv4_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
+			     sk->sk_mark,
+			     inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
+			     inet_sk_flowi_flags(sk));
+}
+EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
+
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 {
 	struct rtable *rt = (struct rtable *) dst;

From 55be7a9c6074f749d617a7fc1914c9a23505438c Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 21:27:49 -0700
Subject: [PATCH 07/16] ipv4: Add redirect support to all protocol icmp error
 handlers.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/dccp/ipv4.c         | 11 +++++++++++
 net/ipv4/ah4.c          | 18 +++++++++++++-----
 net/ipv4/esp4.c         | 18 +++++++++++++-----
 net/ipv4/ip_gre.c       |  9 ++++++++-
 net/ipv4/ipcomp.c       | 18 +++++++++++++-----
 net/ipv4/ipip.c         |  9 +++++++++
 net/ipv4/ping.c         |  1 +
 net/ipv4/raw.c          |  2 ++
 net/ipv4/tcp_ipv4.c     | 11 +++++++++++
 net/ipv4/udp.c          |  3 +++
 net/ipv4/xfrm4_policy.c | 10 ++++++++++
 net/sctp/input.c        | 16 ++++++++++++++++
 12 files changed, 110 insertions(+), 16 deletions(-)

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 3eb76b5f221a..8f41a3190858 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -195,6 +195,14 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
 	} /* else let the usual retransmit timer handle it */
 }
 
+static void dccp_do_redirect(struct sk_buff *skb, struct sock *sk)
+{
+	struct dst_entry *dst = __sk_dst_check(sk, 0);
+
+	if (dst && dst->ops->redirect)
+		dst->ops->redirect(dst, skb);
+}
+
 /*
  * This routine is called by the ICMP module when it gets some sort of error
  * condition. If err < 0 then the socket should be closed and the error
@@ -259,6 +267,9 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
 	}
 
 	switch (type) {
+	case ICMP_REDIRECT:
+		dccp_do_redirect(skb, sk);
+		goto out;
 	case ICMP_SOURCE_QUENCH:
 		/* Just silently ignore these. */
 		goto out;
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 916d5ecaf6c6..a0d8392491c3 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -398,17 +398,25 @@ static void ah4_err(struct sk_buff *skb, u32 info)
 	struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
 	struct xfrm_state *x;
 
-	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+	switch (icmp_hdr(skb)->type) {
+	case ICMP_DEST_UNREACH:
+		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+			return;
+	case ICMP_REDIRECT:
+		break;
+	default:
 		return;
+	}
 
 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 			      ah->spi, IPPROTO_AH, AF_INET);
 	if (!x)
 		return;
-	pr_debug("pmtu discovery on SA AH/%08x/%08x\n",
-		 ntohl(ah->spi), ntohl(iph->daddr));
-	ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
+
+	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
+	else
+		ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 7b95b49a36ce..b61e9deb7c7e 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -484,17 +484,25 @@ static void esp4_err(struct sk_buff *skb, u32 info)
 	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
 	struct xfrm_state *x;
 
-	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+	switch (icmp_hdr(skb)->type) {
+	case ICMP_DEST_UNREACH:
+		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+			return;
+	case ICMP_REDIRECT:
+		break;
+	default:
 		return;
+	}
 
 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 			      esph->spi, IPPROTO_ESP, AF_INET);
 	if (!x)
 		return;
-	NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
-		 ntohl(esph->spi), ntohl(iph->daddr));
-	ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
+
+	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
+	else
+		ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 594cec35ac4d..0c3123566d76 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -528,6 +528,9 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
 		if (code != ICMP_EXC_TTL)
 			return;
 		break;
+
+	case ICMP_REDIRECT:
+		break;
 	}
 
 	rcu_read_lock();
@@ -543,7 +546,11 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
 				 t->parms.link, 0, IPPROTO_GRE, 0);
 		goto out;
 	}
-
+	if (type == ICMP_REDIRECT) {
+		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
+			      IPPROTO_GRE, 0);
+		goto out;
+	}
 	if (t->parms.iph.daddr == 0 ||
 	    ipv4_is_multicast(t->parms.iph.daddr))
 		goto out;
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index b91375482d84..d3ab47e19a89 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -31,18 +31,26 @@ static void ipcomp4_err(struct sk_buff *skb, u32 info)
 	struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
 	struct xfrm_state *x;
 
-	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+	switch (icmp_hdr(skb)->type) {
+	case ICMP_DEST_UNREACH:
+		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+			return;
+	case ICMP_REDIRECT:
+		break;
+	default:
 		return;
+	}
 
 	spi = htonl(ntohs(ipch->cpi));
 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 			      spi, IPPROTO_COMP, AF_INET);
 	if (!x)
 		return;
-	NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n",
-		 spi, &iph->daddr);
-	ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
+
+	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
+	else
+		ipv4_redirect(skb, net, 0, 0, IPPROTO_COMP, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 715338a1b205..c2d0e6d8baaf 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -360,6 +360,8 @@ static int ipip_err(struct sk_buff *skb, u32 info)
 		if (code != ICMP_EXC_TTL)
 			return 0;
 		break;
+	case ICMP_REDIRECT:
+		break;
 	}
 
 	err = -ENOENT;
@@ -376,6 +378,13 @@ static int ipip_err(struct sk_buff *skb, u32 info)
 		goto out;
 	}
 
+	if (type == ICMP_REDIRECT) {
+		ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
+			      IPPROTO_IPIP, 0);
+		err = 0;
+		goto out;
+	}
+
 	if (t->parms.iph.daddr == 0)
 		goto out;
 
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 340fcf29a966..6232d476f37e 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -387,6 +387,7 @@ void ping_err(struct sk_buff *skb, u32 info)
 		break;
 	case ICMP_REDIRECT:
 		/* See ICMP_SOURCE_QUENCH */
+		ipv4_sk_redirect(skb, sk);
 		err = EREMOTEIO;
 		break;
 	}
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 659ddfb10947..ff0f071969ea 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -218,6 +218,8 @@ static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
 
 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
 		ipv4_sk_update_pmtu(skb, sk, info);
+	else if (type == ICMP_REDIRECT)
+		ipv4_sk_redirect(skb, sk);
 
 	/* Report error on raw socket, if:
 	   1. User requested ip_recverr.
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 01545a3fc0f2..087a8488843f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -321,6 +321,14 @@ static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu)
 	} /* else let the usual retransmit timer handle it */
 }
 
+static void do_redirect(struct sk_buff *skb, struct sock *sk)
+{
+	struct dst_entry *dst = __sk_dst_check(sk, 0);
+
+	if (dst && dst->ops->redirect)
+		dst->ops->redirect(dst, skb);
+}
+
 /*
  * This routine is called by the ICMP module when it gets some
  * sort of error condition.  If err < 0 then the socket should
@@ -394,6 +402,9 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
 	}
 
 	switch (type) {
+	case ICMP_REDIRECT:
+		do_redirect(icmp_skb, sk);
+		goto out;
 	case ICMP_SOURCE_QUENCH:
 		/* Just silently ignore these. */
 		goto out;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ee37d47d472e..b4c3582a991f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -630,6 +630,9 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
 			err = icmp_err_convert[code].errno;
 		}
 		break;
+	case ICMP_REDIRECT:
+		ipv4_sk_redirect(skb, sk);
+		break;
 	}
 
 	/*
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 87d3fcc302d4..258ebd7b268b 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -202,6 +202,15 @@ static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
 	path->ops->update_pmtu(path, mtu);
 }
 
+static void xfrm4_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+	struct dst_entry *path = xdst->route;
+
+	if (path->ops->redirect)
+		path->ops->redirect(path, skb);
+}
+
 static void xfrm4_dst_destroy(struct dst_entry *dst)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
@@ -225,6 +234,7 @@ static struct dst_ops xfrm4_dst_ops = {
 	.protocol =		cpu_to_be16(ETH_P_IP),
 	.gc =			xfrm4_garbage_collect,
 	.update_pmtu =		xfrm4_update_pmtu,
+	.redirect =		xfrm4_redirect,
 	.cow_metrics =		dst_cow_metrics_generic,
 	.destroy =		xfrm4_dst_destroy,
 	.ifdown =		xfrm4_dst_ifdown,
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 80564fe03024..9fb4247f9a99 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -423,6 +423,18 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
 	sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
 }
 
+static void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
+			       struct sk_buff *skb)
+{
+	struct dst_entry *dst;
+
+	if (!t)
+		return;
+	dst = sctp_transport_dst_check(t);
+	if (dst && dst->ops->redirect)
+		dst->ops->redirect(dst, skb);
+}
+
 /*
  * SCTP Implementer's Guide, 2.37 ICMP handling procedures
  *
@@ -628,6 +640,10 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info)
 
 		err = EHOSTUNREACH;
 		break;
+	case ICMP_REDIRECT:
+		sctp_icmp_redirect(sk, transport, skb);
+		err = 0;
+		break;
 	default:
 		goto out_unlock;
 	}

From 1f42539d257af671d56d4bdbcf13aef31abff6ef Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 21:30:08 -0700
Subject: [PATCH 08/16] ipv4: Kill ip_rt_redirect().

No longer needed, as the protocol handlers now all properly
propagate the redirect back into the routing code.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/route.h |  1 -
 net/ipv4/icmp.c     |  1 -
 net/ipv4/route.c    | 44 --------------------------------------------
 3 files changed, 46 deletions(-)

diff --git a/include/net/route.h b/include/net/route.h
index 6ab93eeb8660..ace3cb442519 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -108,7 +108,6 @@ extern struct ip_rt_acct __percpu *ip_rt_acct;
 
 struct in_device;
 extern int		ip_rt_init(void);
-extern void		ip_rt_redirect(struct sk_buff *skb, __be32 new_gw);
 extern void		rt_cache_flush(struct net *net, int how);
 extern void		rt_cache_flush_batch(struct net *net);
 extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 70a793559bb5..d01aeb4d492e 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -763,7 +763,6 @@ static void icmp_redirect(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 		return;
 
-	ip_rt_redirect(skb, icmp_hdr(skb)->un.gateway);
 	icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
 }
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index aabece6b729a..e98207dcd088 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1345,50 +1345,6 @@ static void ip_do_redirect(struct dst_entry *dst, struct sk_buff *skb)
 	;
 }
 
-/* called in rcu_read_lock() section */
-void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw)
-{
-	const struct iphdr *iph = (const struct iphdr *) skb->data;
-	__be32 daddr = iph->daddr;
-	__be32 saddr = iph->saddr;
-	struct net_device *dev = skb->dev;
-	int    ikeys[2] = { dev->ifindex, 0 };
-	__be32 skeys[2] = { saddr, 0 };
-	struct net *net;
-	int s, i;
-
-	net = dev_net(dev);
-	for (s = 0; s < 2; s++) {
-		for (i = 0; i < 2; i++) {
-			unsigned int hash;
-			struct rtable __rcu **rthp;
-			struct rtable *rt;
-
-			hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
-
-			rthp = &rt_hash_table[hash].chain;
-
-			while ((rt = rcu_dereference(*rthp)) != NULL) {
-				rthp = &rt->dst.rt_next;
-
-				if (rt->rt_key_dst != daddr ||
-				    rt->rt_key_src != skeys[s] ||
-				    rt->rt_oif != ikeys[i] ||
-				    rt_is_input_route(rt) ||
-				    rt_is_expired(rt) ||
-				    !net_eq(dev_net(rt->dst.dev), net) ||
-				    rt->dst.error ||
-				    rt->dst.dev != dev)
-					continue;
-
-				ip_do_redirect(&rt->dst, skb);
-			}
-		}
-	}
-	return;
-
-}
-
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 {
 	struct rtable *rt = (struct rtable *)dst;

From 30f2a5f379d0b4b4e733df138a49e054ebf75ff8 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 23:26:46 -0700
Subject: [PATCH 09/16] ipv6: Export ndisc option parsing from ndisc.c

This is going to be used internally by the rt6 redirect code.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/ndisc.h | 50 +++++++++++++++++++++++++++++++++++++++++++++
 net/ipv6/ndisc.c    | 47 ++----------------------------------------
 2 files changed, 52 insertions(+), 45 deletions(-)

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index c02b6ad3f6c5..96a3b5c03e37 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -47,6 +47,8 @@ enum {
 #include <linux/icmpv6.h>
 #include <linux/in6.h>
 #include <linux/types.h>
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
 
 #include <net/neighbour.h>
 
@@ -80,6 +82,54 @@ struct nd_opt_hdr {
 	__u8		nd_opt_len;
 } __packed;
 
+/* ND options */
+struct ndisc_options {
+	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
+#ifdef CONFIG_IPV6_ROUTE_INFO
+	struct nd_opt_hdr *nd_opts_ri;
+	struct nd_opt_hdr *nd_opts_ri_end;
+#endif
+	struct nd_opt_hdr *nd_useropts;
+	struct nd_opt_hdr *nd_useropts_end;
+};
+
+#define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
+#define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
+#define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
+#define nd_opts_pi_end		nd_opt_array[__ND_OPT_PREFIX_INFO_END]
+#define nd_opts_rh		nd_opt_array[ND_OPT_REDIRECT_HDR]
+#define nd_opts_mtu		nd_opt_array[ND_OPT_MTU]
+
+#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
+
+extern struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
+						 struct ndisc_options *ndopts);
+
+/*
+ * Return the padding between the option length and the start of the
+ * link addr.  Currently only IP-over-InfiniBand needs this, although
+ * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
+ * also need a pad of 2.
+ */
+static int ndisc_addr_option_pad(unsigned short type)
+{
+	switch (type) {
+	case ARPHRD_INFINIBAND: return 2;
+	default:                return 0;
+	}
+}
+
+static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
+				      struct net_device *dev)
+{
+	u8 *lladdr = (u8 *)(p + 1);
+	int lladdrlen = p->nd_opt_len << 3;
+	int prepad = ndisc_addr_option_pad(dev->type);
+	if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
+		return NULL;
+	return lladdr + prepad;
+}
+
 static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
 {
 	const u32 *p32 = pkey;
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 0fddd571400d..a3189baa9f4f 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -143,40 +143,8 @@ struct neigh_table nd_tbl = {
 	.gc_thresh3 =	1024,
 };
 
-/* ND options */
-struct ndisc_options {
-	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
-#ifdef CONFIG_IPV6_ROUTE_INFO
-	struct nd_opt_hdr *nd_opts_ri;
-	struct nd_opt_hdr *nd_opts_ri_end;
-#endif
-	struct nd_opt_hdr *nd_useropts;
-	struct nd_opt_hdr *nd_useropts_end;
-};
-
-#define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
-#define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
-#define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
-#define nd_opts_pi_end		nd_opt_array[__ND_OPT_PREFIX_INFO_END]
-#define nd_opts_rh		nd_opt_array[ND_OPT_REDIRECT_HDR]
-#define nd_opts_mtu		nd_opt_array[ND_OPT_MTU]
-
 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 
-/*
- * Return the padding between the option length and the start of the
- * link addr.  Currently only IP-over-InfiniBand needs this, although
- * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
- * also need a pad of 2.
- */
-static int ndisc_addr_option_pad(unsigned short type)
-{
-	switch (type) {
-	case ARPHRD_INFINIBAND: return 2;
-	default:                return 0;
-	}
-}
-
 static inline int ndisc_opt_addr_space(struct net_device *dev)
 {
 	return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
@@ -233,8 +201,8 @@ static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 	return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
 }
 
-static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
-						 struct ndisc_options *ndopts)
+struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
+					  struct ndisc_options *ndopts)
 {
 	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 
@@ -297,17 +265,6 @@ static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 	return ndopts;
 }
 
-static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
-				      struct net_device *dev)
-{
-	u8 *lladdr = (u8 *)(p + 1);
-	int lladdrlen = p->nd_opt_len << 3;
-	int prepad = ndisc_addr_option_pad(dev->type);
-	if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
-		return NULL;
-	return lladdr + prepad;
-}
-
 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 {
 	switch (dev->type) {

From e8599ff4b1d6b0d61e1074ae4ba9fca8dd0c41d0 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 11 Jul 2012 23:43:53 -0700
Subject: [PATCH 10/16] ipv6: Move bulk of redirect handling into
 rt6_redirect().

This sets things up so that we can have the protocol error handlers
call down into the ipv6 route code for redirects just as ipv4 already
does.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/ip6_route.h |  7 +---
 net/ipv6/ndisc.c        | 72 +--------------------------------------
 net/ipv6/route.c        | 75 ++++++++++++++++++++++++++++++++++++++---
 3 files changed, 72 insertions(+), 82 deletions(-)

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 58cb3fc34879..5cedbd7688c6 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -133,12 +133,7 @@ extern int			rt6_route_rcv(struct net_device *dev,
 					      u8 *opt, int len,
 					      const struct in6_addr *gwaddr);
 
-extern void			rt6_redirect(const struct in6_addr *dest,
-					     const struct in6_addr *src,
-					     const struct in6_addr *saddr,
-					     struct neighbour *neigh,
-					     u8 *lladdr,
-					     int on_link);
+extern void			rt6_redirect(struct sk_buff *skb);
 
 extern void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 			    int oif, u32 mark);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index a3189baa9f4f..b8d53e186a78 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -143,8 +143,6 @@ struct neigh_table nd_tbl = {
 	.gc_thresh3 =	1024,
 };
 
-#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
-
 static inline int ndisc_opt_addr_space(struct net_device *dev)
 {
 	return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
@@ -1336,16 +1334,6 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 
 static void ndisc_redirect_rcv(struct sk_buff *skb)
 {
-	struct inet6_dev *in6_dev;
-	struct icmp6hdr *icmph;
-	const struct in6_addr *dest;
-	const struct in6_addr *target;	/* new first hop to destination */
-	struct neighbour *neigh;
-	int on_link = 0;
-	struct ndisc_options ndopts;
-	int optlen;
-	u8 *lladdr = NULL;
-
 #ifdef CONFIG_IPV6_NDISC_NODETYPE
 	switch (skb->ndisc_nodetype) {
 	case NDISC_NODETYPE_HOST:
@@ -1362,65 +1350,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
 		return;
 	}
 
-	optlen = skb->tail - skb->transport_header;
-	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
-
-	if (optlen < 0) {
-		ND_PRINTK(2, warn, "Redirect: packet too short\n");
-		return;
-	}
-
-	icmph = icmp6_hdr(skb);
-	target = (const struct in6_addr *) (icmph + 1);
-	dest = target + 1;
-
-	if (ipv6_addr_is_multicast(dest)) {
-		ND_PRINTK(2, warn,
-			  "Redirect: destination address is multicast\n");
-		return;
-	}
-
-	if (ipv6_addr_equal(dest, target)) {
-		on_link = 1;
-	} else if (ipv6_addr_type(target) !=
-		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
-		ND_PRINTK(2, warn,
-			  "Redirect: target address is not link-local unicast\n");
-		return;
-	}
-
-	in6_dev = __in6_dev_get(skb->dev);
-	if (!in6_dev)
-		return;
-	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
-		return;
-
-	/* RFC2461 8.1:
-	 *	The IP source address of the Redirect MUST be the same as the current
-	 *	first-hop router for the specified ICMP Destination Address.
-	 */
-
-	if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
-		ND_PRINTK(2, warn, "Redirect: invalid ND options\n");
-		return;
-	}
-	if (ndopts.nd_opts_tgt_lladdr) {
-		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
-					     skb->dev);
-		if (!lladdr) {
-			ND_PRINTK(2, warn,
-				  "Redirect: invalid link-layer address length\n");
-			return;
-		}
-	}
-
-	neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
-	if (neigh) {
-		rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
-			     &ipv6_hdr(skb)->saddr, neigh, lladdr,
-			     on_link);
-		neigh_release(neigh);
-	}
+	rt6_redirect(skb);
 }
 
 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 563f12c1c99c..73cf3f78aaa8 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1690,14 +1690,78 @@ static struct rt6_info *ip6_route_redirect(const struct in6_addr *dest,
 						   flags, __ip6_route_redirect);
 }
 
-void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src,
-		  const struct in6_addr *saddr,
-		  struct neighbour *neigh, u8 *lladdr, int on_link)
+void rt6_redirect(struct sk_buff *skb)
 {
-	struct rt6_info *rt, *nrt = NULL;
+	struct net *net = dev_net(skb->dev);
 	struct netevent_redirect netevent;
-	struct net *net = dev_net(neigh->dev);
+	struct rt6_info *rt, *nrt = NULL;
+	const struct in6_addr *target;
 	struct neighbour *old_neigh;
+	const struct in6_addr *dest;
+	const struct in6_addr *src;
+	const struct in6_addr *saddr;
+	struct ndisc_options ndopts;
+	struct inet6_dev *in6_dev;
+	struct neighbour *neigh;
+	struct icmp6hdr *icmph;
+	int on_link, optlen;
+	u8 *lladdr = NULL;
+
+	optlen = skb->tail - skb->transport_header;
+	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
+
+	if (optlen < 0) {
+		net_dbg_ratelimited("rt6_redirect: packet too short\n");
+		return;
+	}
+
+	icmph = icmp6_hdr(skb);
+	target = (const struct in6_addr *) (icmph + 1);
+	dest = target + 1;
+
+	if (ipv6_addr_is_multicast(dest)) {
+		net_dbg_ratelimited("rt6_redirect: destination address is multicast\n");
+		return;
+	}
+
+	if (ipv6_addr_equal(dest, target)) {
+		on_link = 1;
+	} else if (ipv6_addr_type(target) !=
+		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
+		net_dbg_ratelimited("rt6_redirect: target address is not link-local unicast\n");
+		return;
+	}
+
+	in6_dev = __in6_dev_get(skb->dev);
+	if (!in6_dev)
+		return;
+	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
+		return;
+
+	/* RFC2461 8.1:
+	 *	The IP source address of the Redirect MUST be the same as the current
+	 *	first-hop router for the specified ICMP Destination Address.
+	 */
+
+	if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
+		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
+		return;
+	}
+	if (ndopts.nd_opts_tgt_lladdr) {
+		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
+					     skb->dev);
+		if (!lladdr) {
+			net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
+			return;
+		}
+	}
+
+	neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
+	if (!neigh)
+		return;
+
+	src = &ipv6_hdr(skb)->daddr;
+	saddr = &ipv6_hdr(skb)->saddr;
 
 	rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
 
@@ -1756,6 +1820,7 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src,
 	}
 
 out:
+	neigh_release(neigh);
 	dst_release(&rt->dst);
 }
 

From 6e157b6ac61aa7758ccd643d4aafdf3cc17b9f04 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:05:02 -0700
Subject: [PATCH 11/16] ipv6: Pull main logic of rt6_redirect() into
 rt6_do_redirect().

Hook it into dst_ops->redirect as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv6/route.c | 80 +++++++++++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 31 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 73cf3f78aaa8..545b1526c143 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -79,6 +79,7 @@ static int		ip6_pkt_discard(struct sk_buff *skb);
 static int		ip6_pkt_discard_out(struct sk_buff *skb);
 static void		ip6_link_failure(struct sk_buff *skb);
 static void		ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
+static void		rt6_do_redirect(struct dst_entry *dst, struct sk_buff *skb);
 
 #ifdef CONFIG_IPV6_ROUTE_INFO
 static struct rt6_info *rt6_add_route_info(struct net *net,
@@ -174,6 +175,7 @@ static struct dst_ops ip6_dst_ops_template = {
 	.negative_advice	=	ip6_negative_advice,
 	.link_failure		=	ip6_link_failure,
 	.update_pmtu		=	ip6_rt_update_pmtu,
+	.redirect		=	rt6_do_redirect,
 	.local_out		=	__ip6_local_out,
 	.neigh_lookup		=	ip6_neigh_lookup,
 };
@@ -1690,28 +1692,26 @@ static struct rt6_info *ip6_route_redirect(const struct in6_addr *dest,
 						   flags, __ip6_route_redirect);
 }
 
-void rt6_redirect(struct sk_buff *skb)
+static void rt6_do_redirect(struct dst_entry *dst, struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
 	struct netevent_redirect netevent;
 	struct rt6_info *rt, *nrt = NULL;
 	const struct in6_addr *target;
-	struct neighbour *old_neigh;
-	const struct in6_addr *dest;
-	const struct in6_addr *src;
-	const struct in6_addr *saddr;
 	struct ndisc_options ndopts;
+	const struct in6_addr *dest;
+	struct neighbour *old_neigh;
 	struct inet6_dev *in6_dev;
 	struct neighbour *neigh;
 	struct icmp6hdr *icmph;
-	int on_link, optlen;
-	u8 *lladdr = NULL;
+	int optlen, on_link;
+	u8 *lladdr;
 
 	optlen = skb->tail - skb->transport_header;
 	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
 
 	if (optlen < 0) {
-		net_dbg_ratelimited("rt6_redirect: packet too short\n");
+		net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
 		return;
 	}
 
@@ -1720,15 +1720,16 @@ void rt6_redirect(struct sk_buff *skb)
 	dest = target + 1;
 
 	if (ipv6_addr_is_multicast(dest)) {
-		net_dbg_ratelimited("rt6_redirect: destination address is multicast\n");
+		net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
 		return;
 	}
 
+	on_link = 0;
 	if (ipv6_addr_equal(dest, target)) {
 		on_link = 1;
 	} else if (ipv6_addr_type(target) !=
 		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
-		net_dbg_ratelimited("rt6_redirect: target address is not link-local unicast\n");
+		net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
 		return;
 	}
 
@@ -1747,6 +1748,8 @@ void rt6_redirect(struct sk_buff *skb)
 		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
 		return;
 	}
+
+	lladdr = NULL;
 	if (ndopts.nd_opts_tgt_lladdr) {
 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
 					     skb->dev);
@@ -1756,19 +1759,26 @@ void rt6_redirect(struct sk_buff *skb)
 		}
 	}
 
+	rt = (struct rt6_info *) dst;
+	if (rt == net->ipv6.ip6_null_entry) {
+		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
+		return;
+	}
+
+	/* Redirect received -> path was valid.
+	 * Look, redirects are sent only in response to data packets,
+	 * so that this nexthop apparently is reachable. --ANK
+	 */
+	dst_confirm(&rt->dst);
+
 	neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
 	if (!neigh)
 		return;
 
-	src = &ipv6_hdr(skb)->daddr;
-	saddr = &ipv6_hdr(skb)->saddr;
-
-	rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
-
-	if (rt == net->ipv6.ip6_null_entry) {
-		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
+	/* Duplicate redirect: silently ignore. */
+	old_neigh = rt->n;
+	if (neigh == old_neigh)
 		goto out;
-	}
 
 	/*
 	 *	We have finally decided to accept it.
@@ -1781,18 +1791,6 @@ void rt6_redirect(struct sk_buff *skb)
 				     NEIGH_UPDATE_F_ISROUTER))
 		     );
 
-	/*
-	 * Redirect received -> path was valid.
-	 * Look, redirects are sent only in response to data packets,
-	 * so that this nexthop apparently is reachable. --ANK
-	 */
-	dst_confirm(&rt->dst);
-
-	/* Duplicate redirect: silently ignore. */
-	old_neigh = rt->n;
-	if (neigh == old_neigh)
-		goto out;
-
 	nrt = ip6_rt_copy(rt, dest);
 	if (!nrt)
 		goto out;
@@ -1815,12 +1813,32 @@ void rt6_redirect(struct sk_buff *skb)
 	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
 
 	if (rt->rt6i_flags & RTF_CACHE) {
+		rt = (struct rt6_info *) dst_clone(&rt->dst);
 		ip6_del_rt(rt);
-		return;
 	}
 
 out:
 	neigh_release(neigh);
+}
+
+void rt6_redirect(struct sk_buff *skb)
+{
+	const struct in6_addr *target;
+	const struct in6_addr *dest;
+	const struct in6_addr *src;
+	const struct in6_addr *saddr;
+	struct icmp6hdr *icmph;
+	struct rt6_info *rt;
+
+	icmph = icmp6_hdr(skb);
+	target = (const struct in6_addr *) (icmph + 1);
+	dest = target + 1;
+
+	src = &ipv6_hdr(skb)->daddr;
+	saddr = &ipv6_hdr(skb)->saddr;
+
+	rt = ip6_route_redirect(dest, src, saddr, skb->dev);
+	rt6_do_redirect(&rt->dst, skb);
 	dst_release(&rt->dst);
 }
 

From 3a5ad2ee5e2c5030d8a303d06f9148a2f893a369 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:08:07 -0700
Subject: [PATCH 12/16] ipv6: Add ip6_redirect() and ip6_sk_redirect() helper
 functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/ip6_route.h |  2 ++
 net/ipv6/route.c        | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 5cedbd7688c6..693940565d8a 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -139,6 +139,8 @@ extern void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 			    int oif, u32 mark);
 extern void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk,
 			       __be32 mtu);
+extern void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark);
+extern void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 
 struct netlink_callback;
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 545b1526c143..f52cf83bb1e0 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1114,6 +1114,33 @@ void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
 }
 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
 
+void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
+{
+	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
+	struct dst_entry *dst;
+	struct flowi6 fl6;
+
+	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_oif = oif;
+	fl6.flowi6_mark = mark;
+	fl6.flowi6_flags = 0;
+	fl6.daddr = iph->daddr;
+	fl6.saddr = iph->saddr;
+	fl6.flowlabel = (*(__be32 *) iph) & IPV6_FLOWINFO_MASK;
+
+	dst = ip6_route_output(net, NULL, &fl6);
+	if (!dst->error)
+		rt6_do_redirect(dst, skb);
+	dst_release(dst);
+}
+EXPORT_SYMBOL_GPL(ip6_redirect);
+
+void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
+{
+	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_redirect);
+
 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
 {
 	struct net_device *dev = dst->dev;

From ec18d9a2691d69cd14b48f9b919fddcef28b7f5c Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:25:15 -0700
Subject: [PATCH 13/16] ipv6: Add redirect support to all protocol icmp error
 handlers.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/sctp/sctp.h |  2 ++
 net/dccp/ipv6.c         |  7 +++++++
 net/ipv6/ah6.c          | 10 ++++++----
 net/ipv6/esp6.c         | 11 +++++++----
 net/ipv6/ip6_tunnel.c   |  7 +++++++
 net/ipv6/ipcomp6.c      | 11 +++++++----
 net/ipv6/raw.c          |  2 ++
 net/ipv6/sit.c          |  8 ++++++++
 net/ipv6/tcp_ipv6.c     |  7 +++++++
 net/ipv6/udp.c          |  2 ++
 net/ipv6/xfrm6_policy.c |  9 +++++++++
 net/sctp/input.c        |  4 ++--
 net/sctp/ipv6.c         |  3 +++
 13 files changed, 69 insertions(+), 14 deletions(-)

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index a2ef81466b00..1f2735dba753 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -162,6 +162,8 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *,
 void sctp_err_finish(struct sock *, struct sctp_association *);
 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 			   struct sctp_transport *t, __u32 pmtu);
+void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
+			struct sk_buff *);
 void sctp_icmp_proto_unreachable(struct sock *sk,
 				 struct sctp_association *asoc,
 				 struct sctp_transport *t);
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 02162cfa5048..b4d7d28ce6d2 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -130,6 +130,13 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	np = inet6_sk(sk);
 
+	if (type == NDISC_REDIRECT) {
+		struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
+
+		if (dst && dst->ops->redirect)
+			dst->ops->redirect(dst, skb);
+	}
+
 	if (type == ICMPV6_PKT_TOOBIG) {
 		struct dst_entry *dst = NULL;
 
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 49d4d26bda88..7e6139508ee7 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -613,16 +613,18 @@ static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	struct xfrm_state *x;
 
 	if (type != ICMPV6_DEST_UNREACH &&
-	    type != ICMPV6_PKT_TOOBIG)
+	    type != ICMPV6_PKT_TOOBIG &&
+	    type != NDISC_REDIRECT)
 		return;
 
 	x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
 	if (!x)
 		return;
 
-	NETDEBUG(KERN_DEBUG "pmtu discovery on SA AH/%08x/%pI6\n",
-		 ntohl(ah->spi), &iph->daddr);
-	ip6_update_pmtu(skb, net, info, 0, 0);
+	if (type == NDISC_REDIRECT)
+		ip6_redirect(skb, net, 0, 0);
+	else
+		ip6_update_pmtu(skb, net, info, 0, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 89a615ba84f8..6dc7fd353ef5 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -434,16 +434,19 @@ static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	struct xfrm_state *x;
 
 	if (type != ICMPV6_DEST_UNREACH &&
-	    type != ICMPV6_PKT_TOOBIG)
+	    type != ICMPV6_PKT_TOOBIG &&
+	    type != NDISC_REDIRECT)
 		return;
 
 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 			      esph->spi, IPPROTO_ESP, AF_INET6);
 	if (!x)
 		return;
-	pr_debug("pmtu discovery on SA ESP/%08x/%pI6\n",
-		 ntohl(esph->spi), &iph->daddr);
-	ip6_update_pmtu(skb, net, info, 0, 0);
+
+	if (type == NDISC_REDIRECT)
+		ip6_redirect(skb, net, 0, 0);
+	else
+		ip6_update_pmtu(skb, net, info, 0, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 6af3fcfdcbbd..0b5b60ec6f4a 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -550,6 +550,9 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		rel_type = ICMP_DEST_UNREACH;
 		rel_code = ICMP_FRAG_NEEDED;
 		break;
+	case NDISC_REDIRECT:
+		rel_type = ICMP_REDIRECT;
+		rel_code = ICMP_REDIR_HOST;
 	default:
 		return 0;
 	}
@@ -608,6 +611,10 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info);
 	}
+	if (rel_type == ICMP_REDIRECT) {
+		if (skb_dst(skb2)->ops->redirect)
+			skb_dst(skb2)->ops->redirect(skb_dst(skb2), skb2);
+	}
 
 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 
diff --git a/net/ipv6/ipcomp6.c b/net/ipv6/ipcomp6.c
index 92832385a8ef..7af5aee75d98 100644
--- a/net/ipv6/ipcomp6.c
+++ b/net/ipv6/ipcomp6.c
@@ -64,7 +64,9 @@ static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		(struct ip_comp_hdr *)(skb->data + offset);
 	struct xfrm_state *x;
 
-	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
+	if (type != ICMPV6_DEST_UNREACH &&
+	    type != ICMPV6_PKT_TOOBIG &&
+	    type != NDISC_REDIRECT)
 		return;
 
 	spi = htonl(ntohs(ipcomph->cpi));
@@ -73,9 +75,10 @@ static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	if (!x)
 		return;
 
-	pr_debug("pmtu discovery on SA IPCOMP/%08x/%pI6\n",
-		 spi, &iph->daddr);
-	ip6_update_pmtu(skb, net, info, 0, 0);
+	if (type == NDISC_REDIRECT)
+		ip6_redirect(skb, net, 0, 0);
+	else
+		ip6_update_pmtu(skb, net, info, 0, 0);
 	xfrm_state_put(x);
 }
 
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index b5c1dcb27737..ef0579d5bca6 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -332,6 +332,8 @@ static void rawv6_err(struct sock *sk, struct sk_buff *skb,
 		ip6_sk_update_pmtu(skb, sk, info);
 		harderr = (np->pmtudisc == IPV6_PMTUDISC_DO);
 	}
+	if (type == NDISC_REDIRECT)
+		ip6_sk_redirect(skb, sk);
 	if (np->recverr) {
 		u8 *payload = skb->data;
 		if (!inet->hdrincl)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 49aea94c9be3..fbf1622fdeef 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -539,6 +539,8 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
 		if (code != ICMP_EXC_TTL)
 			return 0;
 		break;
+	case ICMP_REDIRECT:
+		break;
 	}
 
 	err = -ENOENT;
@@ -557,6 +559,12 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
 		err = 0;
 		goto out;
 	}
+	if (type == ICMP_REDIRECT) {
+		ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
+			      IPPROTO_IPV6, 0);
+		err = 0;
+		goto out;
+	}
 
 	if (t->parms.iph.daddr == 0)
 		goto out;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 70458a9cd837..7249e4bb9b8a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -363,6 +363,13 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	np = inet6_sk(sk);
 
+	if (type == NDISC_REDIRECT) {
+		struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
+
+		if (dst && dst->ops->redirect)
+			dst->ops->redirect(dst,skb);
+	}
+
 	if (type == ICMPV6_PKT_TOOBIG) {
 		struct dst_entry *dst;
 
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 1ecd10249488..99d0077b56b8 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -483,6 +483,8 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	if (type == ICMPV6_PKT_TOOBIG)
 		ip6_sk_update_pmtu(skb, sk, info);
+	if (type == NDISC_REDIRECT)
+		ip6_sk_redirect(skb, sk);
 
 	np = inet6_sk(sk);
 
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index bb02038b822b..f5a9cb8257b9 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -215,6 +215,14 @@ static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
 	path->ops->update_pmtu(path, mtu);
 }
 
+static void xfrm6_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+	struct dst_entry *path = xdst->route;
+
+	path->ops->redirect(path, skb);
+}
+
 static void xfrm6_dst_destroy(struct dst_entry *dst)
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
@@ -261,6 +269,7 @@ static struct dst_ops xfrm6_dst_ops = {
 	.protocol =		cpu_to_be16(ETH_P_IPV6),
 	.gc =			xfrm6_garbage_collect,
 	.update_pmtu =		xfrm6_update_pmtu,
+	.redirect =		xfrm6_redirect,
 	.cow_metrics =		dst_cow_metrics_generic,
 	.destroy =		xfrm6_dst_destroy,
 	.ifdown =		xfrm6_dst_ifdown,
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 9fb4247f9a99..5943b7d77ddb 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -423,8 +423,8 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
 	sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
 }
 
-static void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
-			       struct sk_buff *skb)
+void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
+			struct sk_buff *skb)
 {
 	struct dst_entry *dst;
 
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 91f479121c55..ed7139ea7978 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -185,6 +185,9 @@ SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 			goto out_unlock;
 		}
 		break;
+	case NDISC_REDIRECT:
+		sctp_icmp_redirect(sk, transport, skb);
+		break;
 	default:
 		break;
 	}

From b94f1c0904da9b8bf031667afc48080ba7c3e8c9 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:33:37 -0700
Subject: [PATCH 14/16] ipv6: Use icmpv6_notify() to propagate redirect,
 instead of rt6_redirect().

And delete rt6_redirect(), since it is no longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/ip6_route.h |   2 -
 include/net/ipv6.h      |   2 +
 net/ipv6/icmp.c         |   2 +-
 net/ipv6/ndisc.c        |   2 +-
 net/ipv6/route.c        | 107 ----------------------------------------
 5 files changed, 4 insertions(+), 111 deletions(-)

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 693940565d8a..b6b6f7d6f3c0 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -133,8 +133,6 @@ extern int			rt6_route_rcv(struct net_device *dev,
 					      u8 *opt, int len,
 					      const struct in6_addr *gwaddr);
 
-extern void			rt6_redirect(struct sk_buff *skb);
-
 extern void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 			    int oif, u32 mark);
 extern void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk,
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index d4261d4d6c47..f695f39e8926 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -251,6 +251,8 @@ static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 		atomic_dec(&fl->users);
 }
 
+extern void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
+
 extern int 			ip6_ra_control(struct sock *sk, int sel);
 
 extern int			ipv6_parse_hopopts(struct sk_buff *skb);
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index a113f7d7e938..24d69dbca4d6 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -598,7 +598,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	icmpv6_xmit_unlock(sk);
 }
 
-static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
+void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 {
 	const struct inet6_protocol *ipprot;
 	int inner_offset;
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index b8d53e186a78..ff36194a71aa 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1350,7 +1350,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
 		return;
 	}
 
-	rt6_redirect(skb);
+	icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
 }
 
 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f52cf83bb1e0..7296af144d6c 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1633,92 +1633,6 @@ static int ip6_route_del(struct fib6_config *cfg)
 	return err;
 }
 
-/*
- *	Handle redirects
- */
-struct ip6rd_flowi {
-	struct flowi6 fl6;
-	struct in6_addr gateway;
-};
-
-static struct rt6_info *__ip6_route_redirect(struct net *net,
-					     struct fib6_table *table,
-					     struct flowi6 *fl6,
-					     int flags)
-{
-	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
-	struct rt6_info *rt;
-	struct fib6_node *fn;
-
-	/*
-	 * Get the "current" route for this destination and
-	 * check if the redirect has come from approriate router.
-	 *
-	 * RFC 2461 specifies that redirects should only be
-	 * accepted if they come from the nexthop to the target.
-	 * Due to the way the routes are chosen, this notion
-	 * is a bit fuzzy and one might need to check all possible
-	 * routes.
-	 */
-
-	read_lock_bh(&table->tb6_lock);
-	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
-restart:
-	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
-		/*
-		 * Current route is on-link; redirect is always invalid.
-		 *
-		 * Seems, previous statement is not true. It could
-		 * be node, which looks for us as on-link (f.e. proxy ndisc)
-		 * But then router serving it might decide, that we should
-		 * know truth 8)8) --ANK (980726).
-		 */
-		if (rt6_check_expired(rt))
-			continue;
-		if (!(rt->rt6i_flags & RTF_GATEWAY))
-			continue;
-		if (fl6->flowi6_oif != rt->dst.dev->ifindex)
-			continue;
-		if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
-			continue;
-		break;
-	}
-
-	if (!rt)
-		rt = net->ipv6.ip6_null_entry;
-	BACKTRACK(net, &fl6->saddr);
-out:
-	dst_hold(&rt->dst);
-
-	read_unlock_bh(&table->tb6_lock);
-
-	return rt;
-};
-
-static struct rt6_info *ip6_route_redirect(const struct in6_addr *dest,
-					   const struct in6_addr *src,
-					   const struct in6_addr *gateway,
-					   struct net_device *dev)
-{
-	int flags = RT6_LOOKUP_F_HAS_SADDR;
-	struct net *net = dev_net(dev);
-	struct ip6rd_flowi rdfl = {
-		.fl6 = {
-			.flowi6_oif = dev->ifindex,
-			.daddr = *dest,
-			.saddr = *src,
-		},
-	};
-
-	rdfl.gateway = *gateway;
-
-	if (rt6_need_strict(dest))
-		flags |= RT6_LOOKUP_F_IFACE;
-
-	return (struct rt6_info *)fib6_rule_lookup(net, &rdfl.fl6,
-						   flags, __ip6_route_redirect);
-}
-
 static void rt6_do_redirect(struct dst_entry *dst, struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
@@ -1848,27 +1762,6 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sk_buff *skb)
 	neigh_release(neigh);
 }
 
-void rt6_redirect(struct sk_buff *skb)
-{
-	const struct in6_addr *target;
-	const struct in6_addr *dest;
-	const struct in6_addr *src;
-	const struct in6_addr *saddr;
-	struct icmp6hdr *icmph;
-	struct rt6_info *rt;
-
-	icmph = icmp6_hdr(skb);
-	target = (const struct in6_addr *) (icmph + 1);
-	dest = target + 1;
-
-	src = &ipv6_hdr(skb)->daddr;
-	saddr = &ipv6_hdr(skb)->saddr;
-
-	rt = ip6_route_redirect(dest, src, saddr, skb->dev);
-	rt6_do_redirect(&rt->dst, skb);
-	dst_release(&rt->dst);
-}
-
 /*
  *	Misc support functions
  */

From b587ee3ba21f58b7770a132e6bca5c6658ac5095 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:39:24 -0700
Subject: [PATCH 15/16] net: Add dummy dst_ops->redirect method where needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/bridge/br_netfilter.c | 5 +++++
 net/decnet/dn_route.c     | 6 ++++++
 net/ipv4/route.c          | 5 +++++
 net/ipv6/route.c          | 5 +++++
 4 files changed, 21 insertions(+)

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index b98d3d78ca7f..81f76c402cf2 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -115,6 +115,10 @@ static void fake_update_pmtu(struct dst_entry *dst, u32 mtu)
 {
 }
 
+static void fake_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+}
+
 static u32 *fake_cow_metrics(struct dst_entry *dst, unsigned long old)
 {
 	return NULL;
@@ -136,6 +140,7 @@ static struct dst_ops fake_dst_ops = {
 	.family =		AF_INET,
 	.protocol =		cpu_to_be16(ETH_P_IP),
 	.update_pmtu =		fake_update_pmtu,
+	.redirect =		fake_redirect,
 	.cow_metrics =		fake_cow_metrics,
 	.neigh_lookup =		fake_neigh_lookup,
 	.mtu =			fake_mtu,
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index b5594cc73ee1..e9c4e2e864c6 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -118,6 +118,7 @@ static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 static void dn_dst_link_failure(struct sk_buff *);
 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
+static void dn_dst_redirect(struct dst_entry *dst, struct sk_buff *skb);
 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 					     struct sk_buff *skb,
 					     const void *daddr);
@@ -145,6 +146,7 @@ static struct dst_ops dn_dst_ops = {
 	.negative_advice =	dn_dst_negative_advice,
 	.link_failure =		dn_dst_link_failure,
 	.update_pmtu =		dn_dst_update_pmtu,
+	.redirect =		dn_dst_redirect,
 	.neigh_lookup =		dn_dst_neigh_lookup,
 };
 
@@ -292,6 +294,10 @@ static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
 	}
 }
 
+static void dn_dst_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+}
+
 /*
  * When a route has been marked obsolete. (e.g. routing cache flush)
  */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e98207dcd088..23bbe29b3bba 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2591,6 +2591,10 @@ static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
 {
 }
 
+static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+}
+
 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
 					  unsigned long old)
 {
@@ -2605,6 +2609,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = {
 	.mtu			=	ipv4_blackhole_mtu,
 	.default_advmss		=	ipv4_default_advmss,
 	.update_pmtu		=	ipv4_rt_blackhole_update_pmtu,
+	.redirect		=	ipv4_rt_blackhole_redirect,
 	.cow_metrics		=	ipv4_rt_blackhole_cow_metrics,
 	.neigh_lookup		=	ipv4_neigh_lookup,
 };
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 7296af144d6c..3151aabff5fd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -191,6 +191,10 @@ static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
 {
 }
 
+static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+}
+
 static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst,
 					 unsigned long old)
 {
@@ -205,6 +209,7 @@ static struct dst_ops ip6_dst_blackhole_ops = {
 	.mtu			=	ip6_blackhole_mtu,
 	.default_advmss		=	ip6_default_advmss,
 	.update_pmtu		=	ip6_rt_blackhole_update_pmtu,
+	.redirect		=	ip6_rt_blackhole_redirect,
 	.cow_metrics		=	ip6_rt_blackhole_cow_metrics,
 	.neigh_lookup		=	ip6_neigh_lookup,
 };

From 1ed5c48f231cd00eac0b3d2350ac61e3c825063e Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 12 Jul 2012 00:41:25 -0700
Subject: [PATCH 16/16] net: Remove checks for dst_ops->redirect being NULL.

No longer necessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/dccp/ipv4.c         | 2 +-
 net/dccp/ipv6.c         | 2 +-
 net/ipv4/tcp_ipv4.c     | 2 +-
 net/ipv4/xfrm4_policy.c | 3 +--
 net/ipv6/ip6_tunnel.c   | 6 ++----
 net/ipv6/tcp_ipv6.c     | 2 +-
 net/sctp/input.c        | 2 +-
 7 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 8f41a3190858..129ed8f74138 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -199,7 +199,7 @@ static void dccp_do_redirect(struct sk_buff *skb, struct sock *sk)
 {
 	struct dst_entry *dst = __sk_dst_check(sk, 0);
 
-	if (dst && dst->ops->redirect)
+	if (dst)
 		dst->ops->redirect(dst, skb);
 }
 
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index b4d7d28ce6d2..090c0800ce03 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -133,7 +133,7 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	if (type == NDISC_REDIRECT) {
 		struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 
-		if (dst && dst->ops->redirect)
+		if (dst)
 			dst->ops->redirect(dst, skb);
 	}
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 087a8488843f..7a0062cb4ed0 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -325,7 +325,7 @@ static void do_redirect(struct sk_buff *skb, struct sock *sk)
 {
 	struct dst_entry *dst = __sk_dst_check(sk, 0);
 
-	if (dst && dst->ops->redirect)
+	if (dst)
 		dst->ops->redirect(dst, skb);
 }
 
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 258ebd7b268b..737131cef375 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -207,8 +207,7 @@ static void xfrm4_redirect(struct dst_entry *dst, struct sk_buff *skb)
 	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 	struct dst_entry *path = xdst->route;
 
-	if (path->ops->redirect)
-		path->ops->redirect(path, skb);
+	path->ops->redirect(path, skb);
 }
 
 static void xfrm4_dst_destroy(struct dst_entry *dst)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 0b5b60ec6f4a..61d106597296 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -611,10 +611,8 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info);
 	}
-	if (rel_type == ICMP_REDIRECT) {
-		if (skb_dst(skb2)->ops->redirect)
-			skb_dst(skb2)->ops->redirect(skb_dst(skb2), skb2);
-	}
+	if (rel_type == ICMP_REDIRECT)
+		skb_dst(skb2)->ops->redirect(skb_dst(skb2), skb2);
 
 	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7249e4bb9b8a..3071f377145c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -366,7 +366,7 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	if (type == NDISC_REDIRECT) {
 		struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 
-		if (dst && dst->ops->redirect)
+		if (dst)
 			dst->ops->redirect(dst,skb);
 	}
 
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 5943b7d77ddb..f050d45faa98 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -431,7 +431,7 @@ void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
 	if (!t)
 		return;
 	dst = sctp_transport_dst_check(t);
-	if (dst && dst->ops->redirect)
+	if (dst)
 		dst->ops->redirect(dst, skb);
 }