netfilter: netns: fix {ip,6}_route_me_harder() in netns

Take netns from skb->dst->dev. It should be safe because, they are called
from LOCAL_OUT hook where dst is valid (though, I'm not exactly sure about
IPVS and queueing packets to userspace).

[Patrick: its safe everywhere since they already expect skb->dst to be set]

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 5 insertions, 4 deletions

diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 01671ad51ed3..6efdb70b3eb2 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -12,6 +12,7 @@
 /* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
 int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
 {
+        struct net *net = dev_net(skb->dst->dev);
         const struct iphdr *iph = ip_hdr(skb);
         struct rtable *rt;
         struct flowi fl = {};
@@ -19,7 +20,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
         unsigned int hh_len;
         unsigned int type;
 
-        type = inet_addr_type(&init_net, iph->saddr);
+        type = inet_addr_type(net, iph->saddr);
         if (skb->sk && inet_sk(skb->sk)->transparent)
                 type = RTN_LOCAL;
         if (addr_type == RTN_UNSPEC)
@@ -36,7 +37,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
                 fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
                 fl.mark = skb->mark;
                 fl.flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0;
-                if (ip_route_output_key(&init_net, &rt, &fl) != 0)
+                if (ip_route_output_key(net, &rt, &fl) != 0)
                         return -1;
 
                 /* Drop old route. */
@@ -46,7 +47,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
                 /* non-local src, find valid iif to satisfy
                  * rp-filter when calling ip_route_input. */
                 fl.nl_u.ip4_u.daddr = iph->saddr;
-                if (ip_route_output_key(&init_net, &rt, &fl) != 0)
+                if (ip_route_output_key(net, &rt, &fl) != 0)
                         return -1;
 
                 odst = skb->dst;
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 8c6c5e71f210..4cb4844a3220 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -23,7 +23,7 @@ int ip6_route_me_harder(struct sk_buff *skb)
                     .saddr = iph->saddr, } },
         };
 
-        dst = ip6_route_output(&init_net, skb->sk, &fl);
+        dst = ip6_route_output(dev_net(skb->dst->dev), skb->sk, &fl);
 
 #ifdef CONFIG_XFRM
         if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&