net: Move mtu handling down to the protocol depended handlers
We move all mtu handling from dst_mtu() down to the protocol
layer. So each protocol can implement the mtu handling in
a different manner.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst.h b/include/net/dst.h
index 666de31..6faec1a 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -205,12 +205,7 @@
static inline u32 dst_mtu(const struct dst_entry *dst)
{
- u32 mtu = dst_metric_raw(dst, RTAX_MTU);
-
- if (!mtu)
- mtu = dst->ops->mtu(dst);
-
- return mtu;
+ return dst->ops->mtu(dst);
}
/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index db48679..94f4ec0 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -827,7 +827,9 @@
static unsigned int dn_dst_mtu(const struct dst_entry *dst)
{
- return dst->dev->mtu;
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ return mtu ? : dst->dev->mtu;
}
static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f1ac3ef..11d1b20 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1816,7 +1816,12 @@
static unsigned int ipv4_mtu(const struct dst_entry *dst)
{
- unsigned int mtu = dst->dev->mtu;
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ if (mtu)
+ return mtu;
+
+ mtu = dst->dev->mtu;
if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
const struct rtable *rt = (const struct rtable *) dst;
@@ -2757,7 +2762,9 @@
static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
{
- return dst->dev->mtu;
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ return mtu ? : dst->dev->mtu;
}
static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 76645d7..3399dd3 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -157,7 +157,9 @@
static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
{
- return dst->dev->mtu;
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ return mtu ? : dst->dev->mtu;
}
static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -1043,8 +1045,13 @@
static unsigned int ip6_mtu(const struct dst_entry *dst)
{
- unsigned int mtu = IPV6_MIN_MTU;
struct inet6_dev *idev;
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ if (mtu)
+ return mtu;
+
+ mtu = IPV6_MIN_MTU;
rcu_read_lock();
idev = __in6_dev_get(dst->dev);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index b8be51e..2118d64 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2384,7 +2384,9 @@
static unsigned int xfrm_mtu(const struct dst_entry *dst)
{
- return dst_mtu(dst->path);
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ return mtu ? : dst_mtu(dst->path);
}
static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst, const void *daddr)