From: YOSHIFUJI Hideaki Date: Tue, 21 Mar 2006 01:04:53 +0000 (-0800) Subject: [IPV6]: ROUTE: Add support for Router Preference (RFC4191). X-Git-Tag: v2.6.17-rc1~1175^2~214 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebacaaa0fdf4402cdf4c8e569f54af36b6f0aa2d;p=linux-2.6 [IPV6]: ROUTE: Add support for Router Preference (RFC4191). Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h index 0cf6c8b12c..c771a7db98 100644 --- a/include/linux/icmpv6.h +++ b/include/linux/icmpv6.h @@ -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 " #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 diff --git a/include/linux/ipv6_route.h b/include/linux/ipv6_route.h index d7c41d1d70..f4b085c916 100644 --- a/include/linux/ipv6_route.h +++ b/include/linux/ipv6_route.h @@ -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; diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 01acca06d6..50161322b8 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -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); diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index f925f206d8..c456ead8a4 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -38,6 +38,17 @@ config IPV6_PRIVACY See 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 diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 3b56be8523..966ab6b302 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -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) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 6a068e7f81..a7030fed1a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -251,8 +251,11 @@ static int rt6_score_route(struct rt6_info *rt, int oif, int m = rt6_check_dev(rt, oif); if (!m && (strict & RT6_SELECT_F_IFACE)) return -1; +#ifdef CONFIG_IPV6_ROUTER_PREF + m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2; +#endif if (rt6_check_neigh(rt)) - m |= 4; + m |= 16; else if (strict & RT6_SELECT_F_REACHABLE) return -1; return m; @@ -1256,7 +1259,8 @@ struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *d } struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr, - struct net_device *dev) + struct net_device *dev, + unsigned int pref) { struct in6_rtmsg rtmsg; @@ -1264,7 +1268,8 @@ struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr, rtmsg.rtmsg_type = RTMSG_NEWROUTE; ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr); rtmsg.rtmsg_metric = 1024; - rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES; + rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES | + RTF_PREF(pref); rtmsg.rtmsg_ifindex = dev->ifindex;