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Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c54
1 files changed, 52 insertions, 2 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 844a9ef60dbd..a0fcc47fee73 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -912,6 +912,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
struct dst_entry *dst = &rt->dst;
struct fib_result res;
+ if (dst_metric_locked(dst, RTAX_MTU))
+ return;
+
if (dst->dev->mtu < mtu)
return;
@@ -962,7 +965,7 @@ void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
}
EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
-void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
{
const struct iphdr *iph = (const struct iphdr *) skb->data;
struct flowi4 fl4;
@@ -975,6 +978,53 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
ip_rt_put(rt);
}
}
+
+void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+{
+ const struct iphdr *iph = (const struct iphdr *) skb->data;
+ struct flowi4 fl4;
+ struct rtable *rt;
+ struct dst_entry *dst;
+ bool new = false;
+
+ bh_lock_sock(sk);
+ rt = (struct rtable *) __sk_dst_get(sk);
+
+ if (sock_owned_by_user(sk) || !rt) {
+ __ipv4_sk_update_pmtu(skb, sk, mtu);
+ goto out;
+ }
+
+ __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+
+ if (!__sk_dst_check(sk, 0)) {
+ rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+ if (IS_ERR(rt))
+ goto out;
+
+ new = true;
+ }
+
+ __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
+
+ dst = dst_check(&rt->dst, 0);
+ if (!dst) {
+ if (new)
+ dst_release(&rt->dst);
+
+ rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+ if (IS_ERR(rt))
+ goto out;
+
+ new = true;
+ }
+
+ if (new)
+ __sk_dst_set(sk, &rt->dst);
+
+out:
+ bh_unlock_sock(sk);
+}
EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
void ipv4_redirect(struct sk_buff *skb, struct net *net,
@@ -1120,7 +1170,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
if (!mtu || time_after_eq(jiffies, rt->dst.expires))
mtu = dst_metric_raw(dst, RTAX_MTU);
- if (mtu && rt_is_output_route(rt))
+ if (mtu)
return mtu;
mtu = dst->dev->mtu;