Merge branch 'mpls_multipath'

Roopa Prabhu says:

====================
mpls: multipath support

This patch adds support for MPLS multipath routes.

Includes following changes to support multipath:
- splits struct mpls_route into 'struct mpls_route + struct mpls_nh'.

- struct mpls_nh represents a mpls nexthop label forwarding entry

- Adds support to parse/fill RTA_MULTIPATH netlink attribute for
multipath routes similar to ipv4/v6 fib

- In the process of restructuring, this patch also consistently changes all
labels to u8

$ip -f mpls route add 100 nexthop as 200 via inet 10.1.1.2 dev swp1 \
		nexthop as 700 via inet 10.1.1.6 dev swp2 \
		nexthop as 800 via inet 40.1.1.2 dev swp3

$ip  -f mpls route show
100
	nexthop as to 200 via inet 10.1.1.2  dev swp1
	nexthop as to 700 via inet 10.1.1.6  dev swp2
	nexthop as to 800 via inet 40.1.1.2  dev swp3
====================
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/mpls_iptunnel.h

@@ -18,7 +18,7 @@
 
 struct mpls_iptunnel_encap {
 	u32	label[MAX_NEW_LABELS];
-	u32	labels;
+	u8	labels;
 };
 
 static inline struct mpls_iptunnel_encap *mpls_lwtunnel_encap(struct lwtunnel_state *lwtstate)

net/mpls/internal.h

@@ -21,6 +21,54 @@ struct mpls_dev {
 
 struct sk_buff;
 
+#define LABEL_NOT_SPECIFIED (1 << 20)
+#define MAX_NEW_LABELS 2
+
+/* This maximum ha length copied from the definition of struct neighbour */
+#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
+
+enum mpls_payload_type {
+	MPT_UNSPEC, /* IPv4 or IPv6 */
+	MPT_IPV4 = 4,
+	MPT_IPV6 = 6,
+
+	/* Other types not implemented:
+	 *  - Pseudo-wire with or without control word (RFC4385)
+	 *  - GAL (RFC5586)
+	 */
+};
+
+struct mpls_nh { /* next hop label forwarding entry */
+	struct net_device __rcu *nh_dev;
+	u32			nh_label[MAX_NEW_LABELS];
+	u8			nh_labels;
+	u8			nh_via_alen;
+	u8			nh_via_table;
+	u8			nh_via[MAX_VIA_ALEN];
+};
+
+struct mpls_route { /* next hop label forwarding entry */
+	struct rcu_head		rt_rcu;
+	u8			rt_protocol;
+	u8			rt_payload_type;
+	int			rt_nhn;
+	struct mpls_nh		rt_nh[0];
+};
+
+#define for_nexthops(rt) {						\
+	int nhsel; struct mpls_nh *nh;			\
+	for (nhsel = 0, nh = (rt)->rt_nh;				\
+	     nhsel < (rt)->rt_nhn;					\
+	     nh++, nhsel++)
+
+#define change_nexthops(rt) {						\
+	int nhsel; struct mpls_nh *nh;				\
+	for (nhsel = 0,	nh = (struct mpls_nh *)((rt)->rt_nh);	\
+	     nhsel < (rt)->rt_nhn;					\
+	     nh++, nhsel++)
+
+#define endfor_nexthops(rt) }
+
 static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
 {
 	return (struct mpls_shim_hdr *)skb_network_header(skb);
@@ -52,8 +100,10 @@ static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *
 
 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 		   const u32 label[]);
-int nla_get_labels(const struct nlattr *nla, u32 max_labels, u32 *labels,
+int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
 		   u32 label[]);
+int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
+		u8 via[]);
 bool mpls_output_possible(const struct net_device *dev);
 unsigned int mpls_dev_mtu(const struct net_device *dev);
 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);