netns xfrm: pass netns with KM notifications

SA and SPD flush are executed with NULL SA and SPD respectively, for
these cases pass netns explicitly from userspace socket.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/xfrm.h

@@ -256,6 +256,7 @@ struct km_event
 	u32	seq;
 	u32	pid;
 	u32	event;
+	struct net *net;
 };
 
 struct net_device;

net/key/af_key.c

@@ -1739,6 +1739,7 @@ static int pfkey_flush(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hd
 	c.seq = hdr->sadb_msg_seq;
 	c.pid = hdr->sadb_msg_pid;
 	c.event = XFRM_MSG_FLUSHSA;
+	c.net = &init_net;
 	km_state_notify(NULL, &c);
 
 	return 0;
@@ -2693,6 +2694,7 @@ static int pfkey_spdflush(struct sock *sk, struct sk_buff *skb, struct sadb_msg
 	c.event = XFRM_MSG_FLUSHPOLICY;
 	c.pid = hdr->sadb_msg_pid;
 	c.seq = hdr->sadb_msg_seq;
+	c.net = &init_net;
 	km_policy_notify(NULL, 0, &c);
 
 	return 0;

net/xfrm/xfrm_user.c

@@ -1418,6 +1418,7 @@ static int xfrm_flush_sa(struct sk_buff *skb, struct nlmsghdr *nlh,
 	c.event = nlh->nlmsg_type;
 	c.seq = nlh->nlmsg_seq;
 	c.pid = nlh->nlmsg_pid;
+	c.net = net;
 	km_state_notify(NULL, &c);
 
 	return 0;
@@ -1569,6 +1570,7 @@ static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 	c.event = nlh->nlmsg_type;
 	c.seq = nlh->nlmsg_seq;
 	c.pid = nlh->nlmsg_pid;
+	c.net = net;
 	km_policy_notify(NULL, 0, &c);
 	return 0;
 }
@@ -2084,7 +2086,7 @@ static int xfrm_aevent_state_notify(struct xfrm_state *x, struct km_event *c)
 
 static int xfrm_notify_sa_flush(struct km_event *c)
 {
-	struct net *net = &init_net;
+	struct net *net = c->net;
 	struct xfrm_usersa_flush *p;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
@@ -2446,7 +2448,7 @@ static int xfrm_notify_policy(struct xfrm_policy *xp, int dir, struct km_event *
 
 static int xfrm_notify_policy_flush(struct km_event *c)
 {
-	struct net *net = &init_net;
+	struct net *net = c->net;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;