gre: Support GRE over IPv6

GRE over IPv6 implementation.

Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_arp.h b/include/linux/if_arp.h
index f0e69c6..9adcc29 100644
--- a/include/linux/if_arp.h
+++ b/include/linux/if_arp.h
@@ -92,6 +92,7 @@
 #define ARPHRD_PHONET	820		/* PhoNet media type		*/
 #define ARPHRD_PHONET_PIPE 821		/* PhoNet pipe header		*/
 #define ARPHRD_CAIF	822		/* CAIF media type		*/
+#define ARPHRD_IP6GRE	823		/* GRE over IPv6		*/
 
 #define ARPHRD_VOID	  0xFFFF	/* Void type, nothing is known */
 #define ARPHRD_NONE	  0xFFFE	/* zero header length */
diff --git a/include/linux/if_tunnel.h b/include/linux/if_tunnel.h
index 5efff60..8c5035ac 100644
--- a/include/linux/if_tunnel.h
+++ b/include/linux/if_tunnel.h
@@ -75,6 +75,9 @@
 	IFLA_GRE_TTL,
 	IFLA_GRE_TOS,
 	IFLA_GRE_PMTUDISC,
+	IFLA_GRE_ENCAP_LIMIT,
+	IFLA_GRE_FLOWINFO,
+	IFLA_GRE_FLAGS,
 	__IFLA_GRE_MAX,
 };
 
diff --git a/include/linux/ip6_tunnel.h b/include/linux/ip6_tunnel.h
index bf22b03..48af63c 100644
--- a/include/linux/ip6_tunnel.h
+++ b/include/linux/ip6_tunnel.h
@@ -31,4 +31,21 @@
 	struct in6_addr raddr;	/* remote tunnel end-point address */
 };
 
+struct ip6_tnl_parm2 {
+	char name[IFNAMSIZ];	/* name of tunnel device */
+	int link;		/* ifindex of underlying L2 interface */
+	__u8 proto;		/* tunnel protocol */
+	__u8 encap_limit;	/* encapsulation limit for tunnel */
+	__u8 hop_limit;		/* hop limit for tunnel */
+	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
+	__u32 flags;		/* tunnel flags */
+	struct in6_addr laddr;	/* local tunnel end-point address */
+	struct in6_addr raddr;	/* remote tunnel end-point address */
+
+	__be16			i_flags;
+	__be16			o_flags;
+	__be32			i_key;
+	__be32			o_key;
+};
+
 #endif
diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
index 358fb86..e03047f 100644
--- a/include/net/ip6_tunnel.h
+++ b/include/net/ip6_tunnel.h
@@ -5,6 +5,8 @@
 #include <linux/netdevice.h>
 #include <linux/ip6_tunnel.h>
 
+#define IP6TUNNEL_ERR_TIMEO (30*HZ)
+
 /* capable of sending packets */
 #define IP6_TNL_F_CAP_XMIT 0x10000
 /* capable of receiving packets */
@@ -12,15 +14,40 @@
 /* determine capability on a per-packet basis */
 #define IP6_TNL_F_CAP_PER_PACKET 0x40000
 
-/* IPv6 tunnel */
+struct __ip6_tnl_parm {
+	char name[IFNAMSIZ];	/* name of tunnel device */
+	int link;		/* ifindex of underlying L2 interface */
+	__u8 proto;		/* tunnel protocol */
+	__u8 encap_limit;	/* encapsulation limit for tunnel */
+	__u8 hop_limit;		/* hop limit for tunnel */
+	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
+	__u32 flags;		/* tunnel flags */
+	struct in6_addr laddr;	/* local tunnel end-point address */
+	struct in6_addr raddr;	/* remote tunnel end-point address */
 
+	__be16			i_flags;
+	__be16			o_flags;
+	__be32			i_key;
+	__be32			o_key;
+};
+
+/* IPv6 tunnel */
 struct ip6_tnl {
 	struct ip6_tnl __rcu *next;	/* next tunnel in list */
 	struct net_device *dev;	/* virtual device associated with tunnel */
-	struct ip6_tnl_parm parms;	/* tunnel configuration parameters */
+	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */
 	struct flowi fl;	/* flowi template for xmit */
 	struct dst_entry *dst_cache;    /* cached dst */
 	u32 dst_cookie;
+
+	int err_count;
+	unsigned long err_time;
+
+	/* These fields used only by GRE */
+	__u32 i_seqno;	/* The last seen seqno	*/
+	__u32 o_seqno;	/* The last output seqno */
+	int hlen;       /* Precalculated GRE header length */
+	int mlink;
 };
 
 /* Tunnel encapsulation limit destination sub-option */
@@ -31,4 +58,14 @@
 	__u8 encap_limit;	/* tunnel encapsulation limit   */
 } __packed;
 
+struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t);
+void ip6_tnl_dst_reset(struct ip6_tnl *t);
+void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst);
+int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
+		const struct in6_addr *raddr);
+int ip6_tnl_xmit_ctl(struct ip6_tnl *t);
+__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);
+__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,
+			     const struct in6_addr *raddr);
+
 #endif
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 01c34b3..6d01fb0 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -34,6 +34,7 @@
 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */
 #define NEXTHDR_ROUTING		43	/* Routing header. */
 #define NEXTHDR_FRAGMENT	44	/* Fragmentation/reassembly header. */
+#define NEXTHDR_GRE		47	/* GRE header. */
 #define NEXTHDR_ESP		50	/* Encapsulating security payload. */
 #define NEXTHDR_AUTH		51	/* Authentication header. */
 #define NEXTHDR_ICMP		58	/* ICMP for IPv6. */