From 1f56a01f4ed1bbb36ff2a97f75a6e6231d790cff Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 28 Apr 2015 13:03:03 -0700 Subject: [PATCH] ipv6: Consider RTF_CACHE when searching the fib6 tree It is a prep work for the later bug-fix patch which will stop /128 route from disappearing after pmtu update. The later bug-fix patch will allow a /128 route and its RTF_CACHE clone both exist at the same fib6_node. To do this, we need to prepare the existing fib6 tree search to expect RTF_CACHE for /128 route. Note that the fn->leaf is sorted by rt6i_metric. Hence, RTF_CACHE (if there is any) is always at the front. This property leads to the following: 1. When doing ip6_route_del(), it should honor the RTF_CACHE flag which the caller is used to ask for deleting clone or non-clone. The rtm_to_fib6_config() should also check the RTM_F_CLONED and then set RTF_CACHE accordingly so that: - 'ip -6 r del...' will make ip6_route_del() to delete a route and all its clones. Note that its clones is flushed by fib6_del() - 'ip -6 r flush table cache' will make ip6_route_del() to only delete clone(s). 2. Exclude RTF_CACHE from addrconf_get_prefix_route() which should not configure on a cloned route. 3. No change is need for rt6_device_match() since it currently could return a RTF_CACHE clone route, so the later bug-fix patch will not affect it. Signed-off-by: Martin KaFai Lau Reviewed-by: Hannes Frederic Sowa Cc: Steffen Klassert Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 2 ++ net/ipv6/route.c | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 37b70e82bff8..21c2c818df3b 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2121,6 +2121,8 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx, fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0); if (!fn) goto out; + + noflags |= RTF_CACHE; for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { if (rt->dst.dev->ifindex != dev->ifindex) continue; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 5c48293ff062..4774f13cbf90 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1785,6 +1785,9 @@ static int ip6_route_del(struct fib6_config *cfg) if (fn) { for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { + if ((rt->rt6i_flags & RTF_CACHE) && + !(cfg->fc_flags & RTF_CACHE)) + continue; if (cfg->fc_ifindex && (!rt->dst.dev || rt->dst.dev->ifindex != cfg->fc_ifindex)) @@ -2433,6 +2436,9 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, if (rtm->rtm_type == RTN_LOCAL) cfg->fc_flags |= RTF_LOCAL; + if (rtm->rtm_flags & RTM_F_CLONED) + cfg->fc_flags |= RTF_CACHE; + cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; cfg->fc_nlinfo.nlh = nlh; cfg->fc_nlinfo.nl_net = sock_net(skb->sk);