[NETFILTER]: ip_tables: per-netns FILTER/MANGLE/RAW tables for real

Commit 9335f047fe61587ec82ff12fbb1220bcfdd32006 aka
"[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW"
added per-netns _view_ of iptables rules. They were shown to user, but
ignored by filtering code. Now that it's possible to at least ping loopback,
per-netns tables can affect filtering decisions.

netns is taken in case of
	PRE_ROUTING, LOCAL_IN -- from in device,
	POST_ROUTING, LOCAL_OUT -- from out device,
	FORWARD -- from in device which should be equal to out device's netns.
		   This code is relatively new, so BUG_ON was plugged.

Wrappers were added to a) keep code the same from CONFIG_NET_NS=n users
(overwhelming majority), b) consolidate code in one place -- similar
changes will be done in ipv6 and arp netfilter code.

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

1 files changed, 53 insertions, 1 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 89e6c72ad295..66bc52060fd6 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -6,11 +6,13 @@
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/net.h>
+#include <linux/netdevice.h>
 #include <linux/if.h>
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <linux/wait.h>
 #include <linux/list.h>
+#include <net/net_namespace.h>
 #endif
 #include <linux/compiler.h>
 
@@ -76,7 +78,6 @@ extern void netfilter_init(void);
 #define NF_MAX_HOOKS 8
 
 struct sk_buff;
-struct net_device;
 
 typedef unsigned int nf_hookfn(unsigned int hooknum,
                                struct sk_buff *skb,
@@ -320,5 +321,56 @@ extern void (*nf_ct_destroy)(struct nf_conntrack *);
 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
 #endif
 
+static inline struct net *nf_pre_routing_net(const struct net_device *in,
+                                             const struct net_device *out)
+{
+#ifdef CONFIG_NET_NS
+        return in->nd_net;
+#else
+        return &init_net;
+#endif
+}
+
+static inline struct net *nf_local_in_net(const struct net_device *in,
+                                          const struct net_device *out)
+{
+#ifdef CONFIG_NET_NS
+        return in->nd_net;
+#else
+        return &init_net;
+#endif
+}
+
+static inline struct net *nf_forward_net(const struct net_device *in,
+                                         const struct net_device *out)
+{
+#ifdef CONFIG_NET_NS
+        BUG_ON(in->nd_net != out->nd_net);
+        return in->nd_net;
+#else
+        return &init_net;
+#endif
+}
+
+static inline struct net *nf_local_out_net(const struct net_device *in,
+                                           const struct net_device *out)
+{
+#ifdef CONFIG_NET_NS
+        return out->nd_net;
+#else
+        return &init_net;
+#endif
+}
+
+static inline struct net *nf_post_routing_net(const struct net_device *in,
+                                              const struct net_device *out)
+{
+#ifdef CONFIG_NET_NS
+        return out->nd_net;
+#else
+        return &init_net;
+#endif
+}
+
 #endif /*__KERNEL__*/
 #endif /*__LINUX_NETFILTER_H*/