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Diffstat (limited to 'net/ipv6/route.c')
-rw-r--r--net/ipv6/route.c76
1 files changed, 45 insertions, 31 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9dcfadddd800..b0d5c64e1978 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -128,7 +128,7 @@ struct uncached_list {
static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
-static void rt6_uncached_list_add(struct rt6_info *rt)
+void rt6_uncached_list_add(struct rt6_info *rt)
{
struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
@@ -139,7 +139,7 @@ static void rt6_uncached_list_add(struct rt6_info *rt)
spin_unlock_bh(&ul->lock);
}
-static void rt6_uncached_list_del(struct rt6_info *rt)
+void rt6_uncached_list_del(struct rt6_info *rt)
{
if (!list_empty(&rt->rt6i_uncached)) {
struct uncached_list *ul = rt->rt6i_uncached_list;
@@ -1509,7 +1509,30 @@ static void rt6_exceptions_remove_prefsrc(struct rt6_info *rt)
}
}
-static void rt6_exceptions_update_pmtu(struct rt6_info *rt, int mtu)
+static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
+ struct rt6_info *rt, int mtu)
+{
+ /* If the new MTU is lower than the route PMTU, this new MTU will be the
+ * lowest MTU in the path: always allow updating the route PMTU to
+ * reflect PMTU decreases.
+ *
+ * If the new MTU is higher, and the route PMTU is equal to the local
+ * MTU, this means the old MTU is the lowest in the path, so allow
+ * updating it: if other nodes now have lower MTUs, PMTU discovery will
+ * handle this.
+ */
+
+ if (dst_mtu(&rt->dst) >= mtu)
+ return true;
+
+ if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
+ return true;
+
+ return false;
+}
+
+static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
+ struct rt6_info *rt, int mtu)
{
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
@@ -1518,20 +1541,22 @@ static void rt6_exceptions_update_pmtu(struct rt6_info *rt, int mtu)
bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
lockdep_is_held(&rt6_exception_lock));
- if (bucket) {
- for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
- hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
- struct rt6_info *entry = rt6_ex->rt6i;
- /* For RTF_CACHE with rt6i_pmtu == 0
- * (i.e. a redirected route),
- * the metrics of its rt->dst.from has already
- * been updated.
- */
- if (entry->rt6i_pmtu && entry->rt6i_pmtu > mtu)
- entry->rt6i_pmtu = mtu;
- }
- bucket++;
+ if (!bucket)
+ return;
+
+ for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
+ hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
+ struct rt6_info *entry = rt6_ex->rt6i;
+
+ /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
+ * route), the metrics of its rt->dst.from have already
+ * been updated.
+ */
+ if (entry->rt6i_pmtu &&
+ rt6_mtu_change_route_allowed(idev, entry, mtu))
+ entry->rt6i_pmtu = mtu;
}
+ bucket++;
}
}
@@ -3809,25 +3834,13 @@ static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
Since RFC 1981 doesn't include administrative MTU increase
update PMTU increase is a MUST. (i.e. jumbo frame)
*/
- /*
- If new MTU is less than route PMTU, this new MTU will be the
- lowest MTU in the path, update the route PMTU to reflect PMTU
- decreases; if new MTU is greater than route PMTU, and the
- old MTU is the lowest MTU in the path, update the route PMTU
- to reflect the increase. In this case if the other nodes' MTU
- also have the lowest MTU, TOO BIG MESSAGE will be lead to
- PMTU discovery.
- */
if (rt->dst.dev == arg->dev &&
- dst_metric_raw(&rt->dst, RTAX_MTU) &&
!dst_metric_locked(&rt->dst, RTAX_MTU)) {
spin_lock_bh(&rt6_exception_lock);
- if (dst_mtu(&rt->dst) >= arg->mtu ||
- (dst_mtu(&rt->dst) < arg->mtu &&
- dst_mtu(&rt->dst) == idev->cnf.mtu6)) {
+ if (dst_metric_raw(&rt->dst, RTAX_MTU) &&
+ rt6_mtu_change_route_allowed(idev, rt, arg->mtu))
dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
- }
- rt6_exceptions_update_pmtu(rt, arg->mtu);
+ rt6_exceptions_update_pmtu(idev, rt, arg->mtu);
spin_unlock_bh(&rt6_exception_lock);
}
return 0;
@@ -4099,6 +4112,7 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
r_cfg.fc_encap_type = nla_get_u16(nla);
}
+ r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
rt = ip6_route_info_create(&r_cfg, extack);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);