[PATCH 05/38] Fix ip{,6}_route_me_harder() in netns

[PATCH 05/38] Fix ip{,6}_route_me_harder() in netns

[adobriyan]

ip_route_me_harder() is called on output codepaths:
1) IPVS: honestly, not sure, looks like it can be called during forwarding
2) IPv4 REJECT: refreshing comment re skb->dst is valid and assigment of
   skb->dst right before call :^)
3) NAT: called in LOCAL_OUT hook
4) iptable_mangle: LOCAL_OUT hook
5) nf_ip_reroute(): LOCAL_OUT hook (no clue about queueing packets to luserspace)

ip6_route_me_harder() is also called in output codepaths:
1) ip6table_mangle: LOCAL_OUT hook
2) nf_ip6_reroute: LOCAL_OUT hook (ditto)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 net/ipv4/netfilter.c |    7 ++++---
 net/ipv6/netfilter.c |    3 +--
 2 files changed, 5 insertions(+), 5 deletions(-)

--- 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 (addr_type == RTN_UNSPEC)
 		addr_type = type;
 
@@ -33,7 +34,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
 		fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
 		fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
 		fl.mark = skb->mark;
-		if (ip_route_output_key(&init_net, &rt, &fl) != 0)
+		if (ip_route_output_key(net, &rt, &fl) != 0)
 			return -1;
 
 		/* Drop old route. */
@@ -43,7 +44,7 @@ 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;
--- 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) &&
-- 
1.5.6.3

Re: [PATCH 05/38] Fix ip{,6}_route_me_harder() in netns

[Patrick McHardy]

adobriyan@gmail.com wrote:
> ip_route_me_harder() is called on output codepaths:
> 1) IPVS: honestly, not sure, looks like it can be called during forwarding
> 2) IPv4 REJECT: refreshing comment re skb->dst is valid and assigment of
>    skb->dst right before call :^)
> 3) NAT: called in LOCAL_OUT hook
> 4) iptable_mangle: LOCAL_OUT hook
> 5) nf_ip_reroute(): LOCAL_OUT hook (no clue about queueing packets to luserspace)
> 
> ip6_route_me_harder() is also called in output codepaths:
> 1) ip6table_mangle: LOCAL_OUT hook
> 2) nf_ip6_reroute: LOCAL_OUT hook (ditto)

This changelog doesn't give much clue what the patch is doing
or even what the problem is. It also doesn't seem that you're
very convinced of its correctness.

Please resend with a proper changelog. If you have any questions
about the contexts in which this function is called, just ask.