From 0ee0f47c26b2f909ec95d7d8fed8119e288c4dd3 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Mon, 23 Dec 2019 15:28:15 +0200 Subject: [PATCH] ipv6: Notify multipath route if should be offloaded In a similar fashion to previous patches, only notify the new multipath route if it is the first route in the node or if it was appended to such route. The type of the notification (replace vs. append) is determined based on the number of routes added ('nhn') and the number of sibling routes. If the two do not match, then an append notification should be sent. Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index b59940416cb5..c0809f52f9ef 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5017,6 +5017,32 @@ static void ip6_route_mpath_notify(struct fib6_info *rt, inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); } +static bool ip6_route_mpath_should_notify(const struct fib6_info *rt) +{ + bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); + bool should_notify = false; + struct fib6_info *leaf; + struct fib6_node *fn; + + rcu_read_lock(); + fn = rcu_dereference(rt->fib6_node); + if (!fn) + goto out; + + leaf = rcu_dereference(fn->leaf); + if (!leaf) + goto out; + + if (rt == leaf || + (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric && + rt6_qualify_for_ecmp(leaf))) + should_notify = true; +out: + rcu_read_unlock(); + + return should_notify; +} + static int ip6_route_multipath_add(struct fib6_config *cfg, struct netlink_ext_ack *extack) { @@ -5147,6 +5173,28 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, nhn++; } + /* An in-kernel notification should only be sent in case the new + * multipath route is added as the first route in the node, or if + * it was appended to it. We pass 'rt_notif' since it is the first + * sibling and might allow us to skip some checks in the replace case. + */ + if (ip6_route_mpath_should_notify(rt_notif)) { + enum fib_event_type fib_event; + + if (rt_notif->fib6_nsiblings != nhn - 1) + fib_event = FIB_EVENT_ENTRY_APPEND; + else + fib_event = FIB_EVENT_ENTRY_REPLACE_TMP; + + err = call_fib6_multipath_entry_notifiers(info->nl_net, + fib_event, rt_notif, + nhn - 1, extack); + if (err) { + /* Delete all the siblings that were just added */ + err_nh = NULL; + goto add_errout; + } + } event_type = replace ? FIB_EVENT_ENTRY_REPLACE : FIB_EVENT_ENTRY_ADD; err = call_fib6_multipath_entry_notifiers(info->nl_net, event_type, rt_notif, nhn - 1, extack);