[IPV6] SIT: Add PRL management for ISATAP.

This patch updates the Linux the Intra-Site Automatic Tunnel Addressing
Protocol (ISATAP) implementation. It places the ISATAP potential router
list (PRL) in the kernel and adds three new private ioctls for PRL
management.

[Add several changes of structure name, constant names etc. - yoshfuji]

Signed-off-by: Fred L. Templin <fred.l.templin@boeing.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

include/linux/if_tunnel.h

@@ -7,6 +7,9 @@
 #define SIOCADDTUNNEL   (SIOCDEVPRIVATE + 1)
 #define SIOCDELTUNNEL   (SIOCDEVPRIVATE + 2)
 #define SIOCCHGTUNNEL   (SIOCDEVPRIVATE + 3)
+#define SIOCADDPRL      (SIOCDEVPRIVATE + 5)
+#define SIOCDELPRL      (SIOCDEVPRIVATE + 6)
+#define SIOCCHGPRL      (SIOCDEVPRIVATE + 7)
 
 #define GRE_CSUM	__constant_htons(0x8000)
 #define GRE_ROUTING	__constant_htons(0x4000)
@@ -17,9 +20,6 @@
 #define GRE_FLAGS	__constant_htons(0x00F8)
 #define GRE_VERSION	__constant_htons(0x0007)
 
-/* i_flags values for SIT mode */
-#define	SIT_ISATAP	0x0001
-
 struct ip_tunnel_parm
 {
 	char			name[IFNAMSIZ];
@@ -31,4 +31,16 @@ struct ip_tunnel_parm
 	struct iphdr		iph;
 };
 
+/* SIT-mode i_flags */
+#define	SIT_ISATAP	0x0001
+
+struct ip_tunnel_prl {
+	__be32			addr;
+	__u16			flags;
+	__u16			__reserved;
+};
+
+/* PRL flags */
+#define	PRL_DEFAULT		0x0001
+
 #endif /* _IF_TUNNEL_H_ */

include/linux/skbuff.h

@@ -313,7 +313,8 @@ struct sk_buff {
 	__u16			tc_verd;	/* traffic control verdict */
 #endif
 #endif
-	/* 2 byte hole */
+	__u8			ndisc_nodetype:2;
+	/* 14 bit hole */
 
 #ifdef CONFIG_NET_DMA
 	dma_cookie_t		dma_cookie;