1 files changed, 58 insertions, 40 deletions

diff --git a/net/netfilter/nf_nat_redirect.c b/net/netfilter/nf_nat_redirect.c
index f91579c821e9..5b37487d9d11 100644
--- a/net/netfilter/nf_nat_redirect.c
+++ b/net/netfilter/nf_nat_redirect.c
@@ -10,6 +10,7 @@
 
 #include <linux/if.h>
 #include <linux/inetdevice.h>
+#include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
@@ -24,81 +25,104 @@
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_nat_redirect.h>
 
+static unsigned int
+nf_nat_redirect(struct sk_buff *skb, const struct nf_nat_range2 *range,
+		const union nf_inet_addr *newdst)
+{
+	struct nf_nat_range2 newrange;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+
+	memset(&newrange, 0, sizeof(newrange));
+
+	newrange.flags		= range->flags | NF_NAT_RANGE_MAP_IPS;
+	newrange.min_addr	= *newdst;
+	newrange.max_addr	= *newdst;
+	newrange.min_proto	= range->min_proto;
+	newrange.max_proto	= range->max_proto;
+
+	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
+}
+
 unsigned int
-nf_nat_redirect_ipv4(struct sk_buff *skb,
-		     const struct nf_nat_ipv4_multi_range_compat *mr,
+nf_nat_redirect_ipv4(struct sk_buff *skb, const struct nf_nat_range2 *range,
 		     unsigned int hooknum)
 {
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	__be32 newdst;
-	struct nf_nat_range2 newrange;
+	union nf_inet_addr newdst = {};
 
 	WARN_ON(hooknum != NF_INET_PRE_ROUTING &&
 		hooknum != NF_INET_LOCAL_OUT);
 
-	ct = nf_ct_get(skb, &ctinfo);
-	WARN_ON(!(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));
-
 	/* Local packets: make them go to loopback */
 	if (hooknum == NF_INET_LOCAL_OUT) {
-		newdst = htonl(0x7F000001);
+		newdst.ip = htonl(INADDR_LOOPBACK);
 	} else {
 		const struct in_device *indev;
 
-		newdst = 0;
-
 		indev = __in_dev_get_rcu(skb->dev);
 		if (indev) {
 			const struct in_ifaddr *ifa;
 
 			ifa = rcu_dereference(indev->ifa_list);
 			if (ifa)
-				newdst = ifa->ifa_local;
+				newdst.ip = ifa->ifa_local;
 		}
 
-		if (!newdst)
+		if (!newdst.ip)
 			return NF_DROP;
 	}
 
-	/* Transfer from original range. */
-	memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
-	memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
-	newrange.flags	     = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
-	newrange.min_addr.ip = newdst;
-	newrange.max_addr.ip = newdst;
-	newrange.min_proto   = mr->range[0].min;
-	newrange.max_proto   = mr->range[0].max;
-
-	/* Hand modified range to generic setup. */
-	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
+	return nf_nat_redirect(skb, range, &newdst);
 }
 EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4);
 
 static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
 
+static bool nf_nat_redirect_ipv6_usable(const struct inet6_ifaddr *ifa, unsigned int scope)
+{
+	unsigned int ifa_addr_type = ipv6_addr_type(&ifa->addr);
+
+	if (ifa_addr_type & IPV6_ADDR_MAPPED)
+		return false;
+
+	if ((ifa->flags & IFA_F_TENTATIVE) && (!(ifa->flags & IFA_F_OPTIMISTIC)))
+		return false;
+
+	if (scope) {
+		unsigned int ifa_scope = ifa_addr_type & IPV6_ADDR_SCOPE_MASK;
+
+		if (!(scope & ifa_scope))
+			return false;
+	}
+
+	return true;
+}
+
 unsigned int
 nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
 		     unsigned int hooknum)
 {
-	struct nf_nat_range2 newrange;
-	struct in6_addr newdst;
-	enum ip_conntrack_info ctinfo;
-	struct nf_conn *ct;
+	union nf_inet_addr newdst = {};
 
-	ct = nf_ct_get(skb, &ctinfo);
 	if (hooknum == NF_INET_LOCAL_OUT) {
-		newdst = loopback_addr;
+		newdst.in6 = loopback_addr;
 	} else {
+		unsigned int scope = ipv6_addr_scope(&ipv6_hdr(skb)->daddr);
 		struct inet6_dev *idev;
-		struct inet6_ifaddr *ifa;
 		bool addr = false;
 
 		idev = __in6_dev_get(skb->dev);
 		if (idev != NULL) {
+			const struct inet6_ifaddr *ifa;
+
 			read_lock_bh(&idev->lock);
 			list_for_each_entry(ifa, &idev->addr_list, if_list) {
-				newdst = ifa->addr;
+				if (!nf_nat_redirect_ipv6_usable(ifa, scope))
+					continue;
+
+				newdst.in6 = ifa->addr;
 				addr = true;
 				break;
 			}
@@ -109,12 +133,6 @@ nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
 			return NF_DROP;
 	}
 
-	newrange.flags		= range->flags | NF_NAT_RANGE_MAP_IPS;
-	newrange.min_addr.in6	= newdst;
-	newrange.max_addr.in6	= newdst;
-	newrange.min_proto	= range->min_proto;
-	newrange.max_proto	= range->max_proto;
-
-	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
+	return nf_nat_redirect(skb, range, &newdst);
 }
 EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6);