Commit 95cb5745 authored by Dmitry Popov's avatar Dmitry Popov Committed by David S. Miller
Browse files

ip_tunnel(ipv4): fix tunnels with "local any remote $remote_ip" 



Ipv4 tunnels created with "local any remote $ip" didn't work properly since
7d442fab (ipv4: Cache dst in tunnels). 99% of packets sent via those tunnels
had src addr = 0.0.0.0. That was because only dst_entry was cached, although
fl4.saddr has to be cached too. Every time ip_tunnel_xmit used cached dst_entry
(tunnel_rtable_get returned non-NULL), fl4.saddr was initialized with
tnl_params->saddr (= 0 in our case), and wasn't changed until iptunnel_xmit().

This patch adds saddr to ip_tunnel->dst_cache, fixing this issue.

Reported-by: default avatarSergey Popov <pinkbyte@gentoo.org>
Signed-off-by: default avatarDmitry Popov <ixaphire@qrator.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dabf24d1

include/net/ip_tunnels.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ struct ip_tunnel_prl_entry { 


struct ip_tunnel_dst {

	struct dst_entry __rcu 		*dst;

	__be32				 saddr;

};



struct ip_tunnel {

net/ipv4/ip_tunnel.c

+18 −11
Original line number Diff line number Diff line
@@ -69,23 +69,25 @@ static unsigned int ip_tunnel_hash(__be32 key, __be32 remote) 
}



static void __tunnel_dst_set(struct ip_tunnel_dst *idst,

			     struct dst_entry *dst)

			     struct dst_entry *dst, __be32 saddr)

{

	struct dst_entry *old_dst;



	dst_clone(dst);

	old_dst = xchg((__force struct dst_entry **)&idst->dst, dst);

	dst_release(old_dst);

	idst->saddr = saddr;

}



static void tunnel_dst_set(struct ip_tunnel *t, struct dst_entry *dst)

static void tunnel_dst_set(struct ip_tunnel *t,

			   struct dst_entry *dst, __be32 saddr)

{

	__tunnel_dst_set(this_cpu_ptr(t->dst_cache), dst);

	__tunnel_dst_set(this_cpu_ptr(t->dst_cache), dst, saddr);

}



static void tunnel_dst_reset(struct ip_tunnel *t)

{

	tunnel_dst_set(t, NULL);

	tunnel_dst_set(t, NULL, 0);

}



void ip_tunnel_dst_reset_all(struct ip_tunnel *t)
@@ -93,20 +95,25 @@ void ip_tunnel_dst_reset_all(struct ip_tunnel *t) 
	int i;



	for_each_possible_cpu(i)

		__tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL);

		__tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL, 0);

}

EXPORT_SYMBOL(ip_tunnel_dst_reset_all);



static struct rtable *tunnel_rtable_get(struct ip_tunnel *t, u32 cookie)

static struct rtable *tunnel_rtable_get(struct ip_tunnel *t,

					u32 cookie, __be32 *saddr)

{

	struct ip_tunnel_dst *idst;

	struct dst_entry *dst;



	rcu_read_lock();

	dst = rcu_dereference(this_cpu_ptr(t->dst_cache)->dst);

	idst = this_cpu_ptr(t->dst_cache);

	dst = rcu_dereference(idst->dst);

	if (dst && !atomic_inc_not_zero(&dst->__refcnt))

		dst = NULL;

	if (dst) {

		if (dst->obsolete && dst->ops->check(dst, cookie) == NULL) {

		if (!dst->obsolete || dst->ops->check(dst, cookie)) {

			*saddr = idst->saddr;

		} else {

			tunnel_dst_reset(t);

			dst_release(dst);

			dst = NULL;
@@ -367,7 +374,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev) 


		if (!IS_ERR(rt)) {

			tdev = rt->dst.dev;

			tunnel_dst_set(tunnel, &rt->dst);

			tunnel_dst_set(tunnel, &rt->dst, fl4.saddr);

			ip_rt_put(rt);

		}

		if (dev->type != ARPHRD_ETHER)
@@ -610,7 +617,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 
	init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,

			 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);



	rt = connected ? tunnel_rtable_get(tunnel, 0) : NULL;

	rt = connected ? tunnel_rtable_get(tunnel, 0, &fl4.saddr) : NULL;



	if (!rt) {

		rt = ip_route_output_key(tunnel->net, &fl4);
@@ -620,7 +627,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 
			goto tx_error;

		}

		if (connected)

			tunnel_dst_set(tunnel, &rt->dst);

			tunnel_dst_set(tunnel, &rt->dst, fl4.saddr);

	}



	if (rt->dst.dev == dev) {

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