Commit ebacaaa0 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki Committed by David S. Miller
Browse files

[IPV6]: ROUTE: Add support for Router Preference (RFC4191). 



Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8238dd06

include/linux/icmpv6.h

+9 −2
Original line number Diff line number Diff line
@@ -40,14 +40,16 @@ struct icmp6hdr { 
                struct icmpv6_nd_ra {

			__u8		hop_limit;

#if defined(__LITTLE_ENDIAN_BITFIELD)

			__u8		reserved:6,

			__u8		reserved:4,

					router_pref:2,

					other:1,

					managed:1;



#elif defined(__BIG_ENDIAN_BITFIELD)

			__u8		managed:1,

					other:1,

					reserved:6;

					router_pref:2,

					reserved:4;

#else

#error	"Please fix <asm/byteorder.h>"

#endif
@@ -70,8 +72,13 @@ struct icmp6hdr { 
#define icmp6_addrconf_managed	icmp6_dataun.u_nd_ra.managed

#define icmp6_addrconf_other	icmp6_dataun.u_nd_ra.other

#define icmp6_rt_lifetime	icmp6_dataun.u_nd_ra.rt_lifetime

#define icmp6_router_pref	icmp6_dataun.u_nd_ra.router_pref

};



#define ICMPV6_ROUTER_PREF_LOW		0x3

#define ICMPV6_ROUTER_PREF_MEDIUM	0x0

#define ICMPV6_ROUTER_PREF_HIGH		0x1

#define ICMPV6_ROUTER_PREF_INVALID	0x2



#define ICMPV6_DEST_UNREACH		1

#define ICMPV6_PKT_TOOBIG		2

include/linux/ipv6_route.h

+8 −0
Original line number Diff line number Diff line
@@ -27,8 +27,16 @@ 
#define RTF_FLOW	0x02000000	/* flow significant route	*/

#define RTF_POLICY	0x04000000	/* policy route			*/



#define RTF_PREF(pref)	((pref) << 27)

#define RTF_PREF_MASK	0x18000000



#define RTF_LOCAL	0x80000000



#ifdef __KERNEL__

#define IPV6_EXTRACT_PREF(flag)	(((flag) & RTF_PREF_MASK) >> 27)

#define IPV6_DECODE_PREF(pref)	((pref) ^ 2)	/* 1:low,2:med,3:high */

#endif



struct in6_rtmsg {

	struct in6_addr		rtmsg_dst;

	struct in6_addr		rtmsg_src;

include/net/ip6_route.h

+2 −1
Original line number Diff line number Diff line
@@ -87,7 +87,8 @@ extern struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 
extern struct rt6_info *	rt6_get_dflt_router(struct in6_addr *addr,

						    struct net_device *dev);

extern struct rt6_info *	rt6_add_dflt_router(struct in6_addr *gwaddr,

						    struct net_device *dev);

						    struct net_device *dev,

						    unsigned int pref);



extern void			rt6_purge_dflt_routers(void);

net/ipv6/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -38,6 +38,17 @@ config IPV6_PRIVACY 


	  See <file:Documentation/networking/ip-sysctl.txt> for details.



config IPV6_ROUTER_PREF

	bool "IPv6: Router Preference (RFC 4191) support"

	depends on IPV6

	---help---

	  Router Preference is an optional extension to the Router

	  Advertisement message to improve the ability of hosts

	  to pick more appropriate router, especially when the hosts

	  is placed in a multi-homed network.



	  If unsure, say N.



config INET6_AH

	tristate "IPv6: AH transformation"

	depends on IPV6

net/ipv6/ndisc.c

+11 −1
Original line number Diff line number Diff line
@@ -1023,6 +1023,7 @@ static void ndisc_router_discovery(struct sk_buff *skb) 
	int lifetime;

	struct ndisc_options ndopts;

	int optlen;

	unsigned int pref = 0;



	__u8 * opt = (__u8 *)(ra_msg + 1);
@@ -1086,6 +1087,13 @@ static void ndisc_router_discovery(struct sk_buff *skb) 


	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);



#ifdef CONFIG_IPV6_ROUTER_PREF

	pref = ra_msg->icmph.icmp6_router_pref;

	/* 10b is handled as if it were 00b (medium) */

	if (pref == ICMPV6_ROUTER_PREF_INVALID)

		pref = ICMPV6_ROUTER_PREF_MEDIUM;

#endif



	rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);



	if (rt)
@@ -1101,7 +1109,7 @@ static void ndisc_router_discovery(struct sk_buff *skb) 
		ND_PRINTK3(KERN_DEBUG

			   "ICMPv6 RA: adding default router.\n");



		rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);

		rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev, pref);

		if (rt == NULL) {

			ND_PRINTK0(KERN_ERR

				   "ICMPv6 RA: %s() failed to add default route.\n",
@@ -1120,6 +1128,8 @@ static void ndisc_router_discovery(struct sk_buff *skb) 
			return;

		}

		neigh->flags |= NTF_ROUTER;

	} else if (rt) {

		rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);

	}



	if (rt)