From 509aba3b0d366b7f16a9a2eebac1156b25f5f622 Mon Sep 17 00:00:00 2001 From: FX Le Bail Date: Tue, 7 Jan 2014 14:57:27 +0100 Subject: IPv6: add the option to use anycast addresses as source addresses in echo reply This change allows to follow a recommandation of RFC4942. - Add "anycast_src_echo_reply" sysctl to control the use of anycast addresses as source addresses for ICMPv6 echo reply. This sysctl is false by default to preserve existing behavior. - Add inline check ipv6_anycast_destination(). - Use them in icmpv6_echo_reply(). Reference: RFC4942 - IPv6 Transition/Coexistence Security Considerations (http://tools.ietf.org/html/rfc4942#section-2.1.6) 2.1.6. Anycast Traffic Identification and Security [...] To avoid exposing knowledge about the internal structure of the network, it is recommended that anycast servers now take advantage of the ability to return responses with the anycast address as the source address if possible. Signed-off-by: Francois-Xavier Le Bail Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/ip6_route.h | 7 +++++++ include/net/netns/ipv6.h | 1 + 2 files changed, 8 insertions(+) (limited to 'include') diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 1fb6cddbd44..017badb1aec 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -152,6 +152,13 @@ static inline bool ipv6_unicast_destination(const struct sk_buff *skb) return rt->rt6i_flags & RTF_LOCAL; } +static inline bool ipv6_anycast_destination(const struct sk_buff *skb) +{ + struct rt6_info *rt = (struct rt6_info *) skb_dst(skb); + + return rt->rt6i_flags & RTF_ANYCAST; +} + int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); static inline int ip6_skb_dst_mtu(struct sk_buff *skb) diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 0fb2401197c..76fc7d1dbfd 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -73,6 +73,7 @@ struct netns_ipv6 { #endif atomic_t dev_addr_genid; atomic_t rt_genid; + int anycast_src_echo_reply; }; #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) -- cgit v1.2.3-70-g09d2