netns xfrm: per-netns NETLINK_XFRM socket

Stub senders to init_net's one temporarily.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/xfrm.h

@@ -39,6 +39,8 @@ struct netns_xfrm {
 	struct xfrm_policy_hash	policy_bydst[XFRM_POLICY_MAX * 2];
 	unsigned int		policy_count[XFRM_POLICY_MAX * 2];
 	struct work_struct	policy_hash_work;
+
+	struct sock		*nlsk;
 };
 
 #endif

include/net/xfrm.h

@@ -48,7 +48,6 @@ DECLARE_SNMP_STAT(struct linux_xfrm_mib, xfrm_statistics);
 #define XFRM_INC_STATS_USER(field)
 #endif
 
-extern struct sock *xfrm_nl;
 extern u32 sysctl_xfrm_aevent_etime;
 extern u32 sysctl_xfrm_aevent_rseqth;
 extern int sysctl_xfrm_larval_drop;
@@ -1516,18 +1515,20 @@ static inline int xfrm_policy_id2dir(u32 index)
 	return index & 7;
 }
 
-static inline int xfrm_aevent_is_on(void)
+#ifdef CONFIG_XFRM
+static inline int xfrm_aevent_is_on(struct net *net)
 {
 	struct sock *nlsk;
 	int ret = 0;
 
 	rcu_read_lock();
-	nlsk = rcu_dereference(xfrm_nl);
+	nlsk = rcu_dereference(net->xfrm.nlsk);
 	if (nlsk)
 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
 	rcu_read_unlock();
 	return ret;
 }
+#endif
 
 static inline int xfrm_alg_len(struct xfrm_algo *alg)
 {

net/xfrm/xfrm_output.c

@@ -41,6 +41,7 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 {
 	struct dst_entry *dst = skb->dst;
 	struct xfrm_state *x = dst->xfrm;
+	struct net *net = xs_net(x);
 
 	if (err <= 0)
 		goto resume;
@@ -74,7 +75,7 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 				err = -EOVERFLOW;
 				goto error;
 			}
-			if (xfrm_aevent_is_on())
+			if (xfrm_aevent_is_on(net))
 				xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
 		}
 

net/xfrm/xfrm_state.c

@@ -24,9 +24,6 @@
 
 #include "xfrm_hash.h"
 
-struct sock *xfrm_nl;
-EXPORT_SYMBOL(xfrm_nl);
-
 u32 sysctl_xfrm_aevent_etime __read_mostly = XFRM_AE_ETIME;
 EXPORT_SYMBOL(sysctl_xfrm_aevent_etime);
 
@@ -1659,7 +1656,7 @@ static void xfrm_replay_timer_handler(unsigned long data)
 	spin_lock(&x->lock);
 
 	if (x->km.state == XFRM_STATE_VALID) {
-		if (xfrm_aevent_is_on())
+		if (xfrm_aevent_is_on(xs_net(x)))
 			xfrm_replay_notify(x, XFRM_REPLAY_TIMEOUT);
 		else
 			x->xflags |= XFRM_TIME_DEFER;
@@ -1715,7 +1712,7 @@ void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
 		x->replay.bitmap |= (1U << diff);
 	}
 
-	if (xfrm_aevent_is_on())
+	if (xfrm_aevent_is_on(xs_net(x)))
 		xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
 }