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 <s...@queasysnail.net>
Reviewed-by: Stefano Brivio <sbri...@redhat.com>
---
include/net/ip6_fib.h | 4 ++++
net/ipv6/route.c | 12 ++++++------
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 3d4930528db0..2d31e22babd8 100644
--- 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;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index a366c05a239d..abcb5ae77319 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -520,10 +520,11 @@ static void rt6_probe_deferred(struct work_struct *w)
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
@@ -539,15 +540,12 @@ static void rt6_probe(struct fib6_info *rt)
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,
@@ -557,11 +555,13 @@ static void rt6_probe(struct fib6_info *rt)
__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);
--
2.19.1
