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-rw-r--r--net/ipv4/fib_frontend.c12
-rw-r--r--net/ipv4/fib_semantics.c50
-rw-r--r--net/ipv4/route.c7
-rw-r--r--net/ipv4/udp.c2
4 files changed, 63 insertions, 8 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 038f511c73fa..0f1beceb47d5 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1291,7 +1291,8 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct netdev_notifier_changeupper_info *info;
+ struct netdev_notifier_changeupper_info *upper_info = ptr;
+ struct netdev_notifier_info_ext *info_ext = ptr;
struct in_device *in_dev;
struct net *net = dev_net(dev);
unsigned int flags;
@@ -1326,16 +1327,19 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
fib_sync_up(dev, RTNH_F_LINKDOWN);
else
fib_sync_down_dev(dev, event, false);
- /* fall through */
+ rt_cache_flush(net);
+ break;
case NETDEV_CHANGEMTU:
+ fib_sync_mtu(dev, info_ext->ext.mtu);
rt_cache_flush(net);
break;
case NETDEV_CHANGEUPPER:
- info = ptr;
+ upper_info = ptr;
/* flush all routes if dev is linked to or unlinked from
* an L3 master device (e.g., VRF)
*/
- if (info->upper_dev && netif_is_l3_master(info->upper_dev))
+ if (upper_info->upper_dev &&
+ netif_is_l3_master(upper_info->upper_dev))
fib_disable_ip(dev, NETDEV_DOWN, true);
break;
}
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f8c7ec8171a8..b5c3937ca6ec 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1457,6 +1457,56 @@ static int call_fib_nh_notifiers(struct fib_nh *fib_nh,
return NOTIFY_DONE;
}
+/* Update the PMTU of exceptions when:
+ * - the new MTU of the first hop becomes smaller than the PMTU
+ * - the old MTU was the same as the PMTU, and it limited discovery of
+ * larger MTUs on the path. With that limit raised, we can now
+ * discover larger MTUs
+ * A special case is locked exceptions, for which the PMTU is smaller
+ * than the minimal accepted PMTU:
+ * - if the new MTU is greater than the PMTU, don't make any change
+ * - otherwise, unlock and set PMTU
+ */
+static void nh_update_mtu(struct fib_nh *nh, u32 new, u32 orig)
+{
+ struct fnhe_hash_bucket *bucket;
+ int i;
+
+ bucket = rcu_dereference_protected(nh->nh_exceptions, 1);
+ if (!bucket)
+ return;
+
+ for (i = 0; i < FNHE_HASH_SIZE; i++) {
+ struct fib_nh_exception *fnhe;
+
+ for (fnhe = rcu_dereference_protected(bucket[i].chain, 1);
+ fnhe;
+ fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) {
+ if (fnhe->fnhe_mtu_locked) {
+ if (new <= fnhe->fnhe_pmtu) {
+ fnhe->fnhe_pmtu = new;
+ fnhe->fnhe_mtu_locked = false;
+ }
+ } else if (new < fnhe->fnhe_pmtu ||
+ orig == fnhe->fnhe_pmtu) {
+ fnhe->fnhe_pmtu = new;
+ }
+ }
+ }
+}
+
+void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
+{
+ unsigned int hash = fib_devindex_hashfn(dev->ifindex);
+ struct hlist_head *head = &fib_info_devhash[hash];
+ struct fib_nh *nh;
+
+ hlist_for_each_entry(nh, head, nh_hash) {
+ if (nh->nh_dev == dev)
+ nh_update_mtu(nh, dev->mtu, orig_mtu);
+ }
+}
+
/* Event force Flags Description
* NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
* NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f71d2395c428..c0a9d26c06ce 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1001,21 +1001,22 @@ out: kfree_skb(skb);
static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
{
struct dst_entry *dst = &rt->dst;
+ u32 old_mtu = ipv4_mtu(dst);
struct fib_result res;
bool lock = false;
if (ip_mtu_locked(dst))
return;
- if (ipv4_mtu(dst) < mtu)
+ if (old_mtu < mtu)
return;
if (mtu < ip_rt_min_pmtu) {
lock = true;
- mtu = ip_rt_min_pmtu;
+ mtu = min(old_mtu, ip_rt_min_pmtu);
}
- if (rt->rt_pmtu == mtu &&
+ if (rt->rt_pmtu == mtu && !lock &&
time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
return;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1bec2203d558..cf8252d05a01 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1627,7 +1627,7 @@ busy_check:
*err = error;
return NULL;
}
-EXPORT_SYMBOL_GPL(__skb_recv_udp);
+EXPORT_SYMBOL(__skb_recv_udp);
/*
* This should be easy, if there is something there we