From be7a010d6fa33dca9327ad8e91844278dfd1e712 Mon Sep 17 00:00:00 2001 From: Duan Jiong Date: Thu, 15 May 2014 15:56:14 +0800 Subject: ipv6: update Destination Cache entries when gateway turn into host RFC 4861 states in 7.2.5: The IsRouter flag in the cache entry MUST be set based on the Router flag in the received advertisement. In those cases where the IsRouter flag changes from TRUE to FALSE as a result of this update, the node MUST remove that router from the Default Router List and update the Destination Cache entries for all destinations using that neighbor as a router as specified in Section 7.3.3. This is needed to detect when a node that is used as a router stops forwarding packets due to being configured as a host. Currently, when dealing with NA Message which IsRouter flag changes from TRUE to FALSE, the kernel only removes router from the Default Router List, and don't update the Destination Cache entries. Now in order to update those Destination Cache entries, i introduce function rt6_clean_tohost(). Signed-off-by: Duan Jiong Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/route.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'net/ipv6/route.c') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 004fffb..58c449a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2234,6 +2234,27 @@ void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) fib6_clean_all(net, fib6_remove_prefsrc, &adni); } +#define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY) +#define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE) + +/* Remove routers and update dst entries when gateway turn into host. */ +static int fib6_clean_tohost(struct rt6_info *rt, void *arg) +{ + struct in6_addr *gateway = (struct in6_addr *)arg; + + if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) || + ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) && + ipv6_addr_equal(gateway, &rt->rt6i_gateway)) { + return -1; + } + return 0; +} + +void rt6_clean_tohost(struct net *net, struct in6_addr *gateway) +{ + fib6_clean_all(net, fib6_clean_tohost, gateway); +} + struct arg_dev_net { struct net_device *dev; struct net *net; -- cgit v1.1