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

Ipv4 tunnels created with "local any remote $ip" didn't work properly since
7d442fab0 (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: Sergey Popov <pinkbyte@gentoo.org>
Signed-off-by: Dmitry Popov <ixaphire@qrator.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index a4daf9eb856285a2b7c831ee04d4e75a39957142..8dd8cab88b873cda0d8de9c936fefc0850ef0703 100644 (file)
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -40,6 +40,7 @@ struct ip_tunnel_prl_entry {
 
 struct ip_tunnel_dst {
        struct dst_entry __rcu          *dst;
+       __be32                           saddr;
 };
 
 struct ip_tunnel {

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 6f9de61dce5f9585625443af1d372ddb931adf03..45920d928341576ea243a67b78cf7abe5b1d5537 100644 (file)
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -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) {