netns xfrm: add struct xfrm_state::xs_net

To avoid unnecessary complications with passing netns around.

* set once, very early after allocating
* once set, never changes

For a while create every xfrm_state in init_net.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/xfrm.h

@@ -130,6 +130,9 @@ struct xfrm_state_walk {
 /* Full description of state of transformer. */
 struct xfrm_state
 {
+#ifdef CONFIG_NET_NS
+	struct net		*xs_net;
+#endif
 	union {
 		struct hlist_node	gclist;
 		struct hlist_node	bydst;
@@ -223,6 +226,11 @@ struct xfrm_state
 	void			*data;
 };
 
+static inline struct net *xs_net(struct xfrm_state *x)
+{
+	return read_pnet(&x->xs_net);
+}
+
 /* xflags - make enum if more show up */
 #define XFRM_TIME_DEFER	1
 
@@ -1296,7 +1304,7 @@ extern void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto);
 extern int xfrm_state_walk(struct xfrm_state_walk *walk,
 			   int (*func)(struct xfrm_state *, int, void*), void *);
 extern void xfrm_state_walk_done(struct xfrm_state_walk *walk);
-extern struct xfrm_state *xfrm_state_alloc(void);
+extern struct xfrm_state *xfrm_state_alloc(struct net *net);
 extern struct xfrm_state *xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr, 
 					  struct flowi *fl, struct xfrm_tmpl *tmpl,
 					  struct xfrm_policy *pol, int *err,

net/ipv4/ipcomp.c

@@ -49,7 +49,7 @@ static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
 {
 	struct xfrm_state *t;
 
-	t = xfrm_state_alloc();
+	t = xfrm_state_alloc(&init_net);
 	if (t == NULL)
 		goto out;
 

net/ipv6/ipcomp6.c

@@ -76,7 +76,7 @@ static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
 {
 	struct xfrm_state *t = NULL;
 
-	t = xfrm_state_alloc();
+	t = xfrm_state_alloc(&init_net);
 	if (!t)
 		goto out;
 

net/key/af_key.c

@@ -1122,7 +1122,7 @@ static struct xfrm_state * pfkey_msg2xfrm_state(struct sadb_msg *hdr,
 	     (key->sadb_key_bits+7) / 8 > key->sadb_key_len * sizeof(uint64_t)))
 		return ERR_PTR(-EINVAL);
 
-	x = xfrm_state_alloc();
+	x = xfrm_state_alloc(&init_net);
 	if (x == NULL)
 		return ERR_PTR(-ENOBUFS);
 

net/xfrm/xfrm_state.c

@@ -504,13 +504,14 @@ static void xfrm_timer_handler(unsigned long data)
 
 static void xfrm_replay_timer_handler(unsigned long data);
 
-struct xfrm_state *xfrm_state_alloc(void)
+struct xfrm_state *xfrm_state_alloc(struct net *net)
 {
 	struct xfrm_state *x;
 
 	x = kzalloc(sizeof(struct xfrm_state), GFP_ATOMIC);
 
 	if (x) {
+		write_pnet(&x->xs_net, net);
 		atomic_set(&x->refcnt, 1);
 		atomic_set(&x->tunnel_users, 0);
 		INIT_LIST_HEAD(&x->km.all);
@@ -835,7 +836,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
 			error = -EEXIST;
 			goto out;
 		}
-		x = xfrm_state_alloc();
+		x = xfrm_state_alloc(&init_net);
 		if (x == NULL) {
 			error = -ENOMEM;
 			goto out;
@@ -1017,7 +1018,7 @@ static struct xfrm_state *__find_acq_core(unsigned short family, u8 mode, u32 re
 	if (!create)
 		return NULL;
 
-	x = xfrm_state_alloc();
+	x = xfrm_state_alloc(&init_net);
 	if (likely(x)) {
 		switch (family) {
 		case AF_INET:
@@ -1125,7 +1126,7 @@ EXPORT_SYMBOL(xfrm_state_add);
 static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig, int *errp)
 {
 	int err = -ENOMEM;
-	struct xfrm_state *x = xfrm_state_alloc();
+	struct xfrm_state *x = xfrm_state_alloc(&init_net);
 	if (!x)
 		goto error;
 

net/xfrm/xfrm_user.c

@@ -320,7 +320,7 @@ static struct xfrm_state *xfrm_state_construct(struct xfrm_usersa_info *p,
 					       struct nlattr **attrs,
 					       int *errp)
 {
-	struct xfrm_state *x = xfrm_state_alloc();
+	struct xfrm_state *x = xfrm_state_alloc(&init_net);
 	int err = -ENOMEM;
 
 	if (!x)
@@ -1663,7 +1663,7 @@ static int xfrm_add_acquire(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct nlattr *rt = attrs[XFRMA_TMPL];
 
 	struct xfrm_user_acquire *ua = nlmsg_data(nlh);
-	struct xfrm_state *x = xfrm_state_alloc();
+	struct xfrm_state *x = xfrm_state_alloc(&init_net);
 	int err = -ENOMEM;
 
 	if (!x)