4.18-stable review patch. If anyone has any objections, please let me know.
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From: Sabrina Dubroca sd@queasysnail.net
[ Upstream commit f547fac624be53ad8b07e9ebca7654a7827ba61b ]
When commit 270972554c91 ("[IPV6]: ROUTE: Add Router Reachability Probing (RFC4191).") introduced router probing, the rt6_probe() function required that a neighbour entry existed. This neighbour entry is used to record the timestamp of the last probe via the ->updated field.
Later, commit 2152caea7196 ("ipv6: Do not depend on rt->n in rt6_probe().") removed the requirement for a neighbour entry. Neighbourless routes skip the interval check and are not rate-limited.
This patch adds rate-limiting for neighbourless routes, by recording the timestamp of the last probe in the fib6_info itself.
Fixes: 2152caea7196 ("ipv6: Do not depend on rt->n in rt6_probe().") Signed-off-by: Sabrina Dubroca sd@queasysnail.net Reviewed-by: Stefano Brivio sbrivio@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/net/ip6_fib.h | 4 ++++ net/ipv6/route.c | 12 ++++++------ 2 files changed, 10 insertions(+), 6 deletions(-)
--- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -159,6 +159,10 @@ struct fib6_info { struct rt6_info * __percpu *rt6i_pcpu; struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
+#ifdef CONFIG_IPV6_ROUTER_PREF + unsigned long last_probe; +#endif + u32 fib6_metric; u8 fib6_protocol; u8 fib6_type; --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -517,10 +517,11 @@ static void rt6_probe_deferred(struct wo
static void rt6_probe(struct fib6_info *rt) { - struct __rt6_probe_work *work; + struct __rt6_probe_work *work = NULL; const struct in6_addr *nh_gw; struct neighbour *neigh; struct net_device *dev; + struct inet6_dev *idev;
/* * Okay, this does not seem to be appropriate @@ -536,15 +537,12 @@ static void rt6_probe(struct fib6_info * nh_gw = &rt->fib6_nh.nh_gw; dev = rt->fib6_nh.nh_dev; rcu_read_lock_bh(); + idev = __in6_dev_get(dev); neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); if (neigh) { - struct inet6_dev *idev; - if (neigh->nud_state & NUD_VALID) goto out;
- idev = __in6_dev_get(dev); - work = NULL; write_lock(&neigh->lock); if (!(neigh->nud_state & NUD_VALID) && time_after(jiffies, @@ -554,11 +552,13 @@ static void rt6_probe(struct fib6_info * __neigh_set_probe_once(neigh); } write_unlock(&neigh->lock); - } else { + } else if (time_after(jiffies, rt->last_probe + + idev->cnf.rtr_probe_interval)) { work = kmalloc(sizeof(*work), GFP_ATOMIC); }
if (work) { + rt->last_probe = jiffies; INIT_WORK(&work->work, rt6_probe_deferred); work->target = *nh_gw; dev_hold(dev);