xfrm: export verify_userspi_info for pkfey and netlink interface

In order to check against valid IPcomp spi range, export verify_userspi_info
for both pfkey and netlink interface.

Signed-off-by: Fan Du <[e-mail]>
Signed-off-by: Steffen Klassert <[e-mail]>

include/net/xfrm.h

···
 				     u32 id, int delete, int *err);
 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info);
 u32 xfrm_get_acqseq(void);
+int verify_spi_info(u8 proto, u32 min, u32 max);
 int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
 struct xfrm_state *xfrm_find_acq(struct net *net, const struct xfrm_mark *mark,
 				 u8 mode, u32 reqid, u8 proto,

net/key/af_key.c

···
 		max_spi = range->sadb_spirange_max;
 	}
 
+	err = verify_spi_info(x->id.proto, min_spi, max_spi);
+	if (err) {
+		xfrm_state_put(x);
+		return err;
+	}
+
 	err = xfrm_alloc_spi(x, min_spi, max_spi);
 	resp_skb = err ? ERR_PTR(err) : pfkey_xfrm_state2msg(x);
 

net/xfrm/xfrm_state.c

···
 }
 EXPORT_SYMBOL(xfrm_get_acqseq);
 
+int verify_spi_info(u8 proto, u32 min, u32 max)
+{
+	switch (proto) {
+	case IPPROTO_AH:
+	case IPPROTO_ESP:
+		break;
+
+	case IPPROTO_COMP:
+		/* IPCOMP spi is 16-bits. */
+		if (max >= 0x10000)
+			return -EINVAL;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (min > max)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(verify_spi_info);
+
 int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 {
 	struct net *net = xs_net(x);

net/xfrm/xfrm_user.c

···
 	return err;
 }
 
-static int verify_userspi_info(struct xfrm_userspi_info *p)
-{
-	switch (p->info.id.proto) {
-	case IPPROTO_AH:
-	case IPPROTO_ESP:
-		break;
-
-	case IPPROTO_COMP:
-		/* IPCOMP spi is 16-bits. */
-		if (p->max >= 0x10000)
-			return -EINVAL;
-		break;
-
-	default:
-		return -EINVAL;
-	}
-
-	if (p->min > p->max)
-		return -EINVAL;
-
-	return 0;
-}
-
 static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh,
 		struct nlattr **attrs)
 {
···
 	struct xfrm_mark m;
 
 	p = nlmsg_data(nlh);
-	err = verify_userspi_info(p);
+	err = verify_spi_info(p->info.id.proto, p->min, p->max);
 	if (err)
 		goto out_noput;