summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/net/ip.h12
-rw-r--r--include/net/ip6_route.h16
-rw-r--r--net/ipv4/route.c3
3 files changed, 22 insertions, 9 deletions
diff --git a/include/net/ip.h b/include/net/ip.h
index e20874059f82..d9683bef8684 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -31,6 +31,7 @@
#include <net/flow.h>
#include <net/flow_dissector.h>
#include <net/netns/hash.h>
+#include <net/lwtunnel.h>
#define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
#define IPV4_MIN_MTU 68 /* RFC 791 */
@@ -445,22 +446,25 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
/* 'forwarding = true' case should always honour route mtu */
mtu = dst_metric_raw(dst, RTAX_MTU);
- if (mtu)
- return mtu;
+ if (!mtu)
+ mtu = min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
- return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
+ return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
}
static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
const struct sk_buff *skb)
{
+ unsigned int mtu;
+
if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
}
- return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
+ mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
+ return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
}
struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index f51a118bfce8..f14149df5a65 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -265,11 +265,18 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
{
+ int mtu;
+
struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
inet6_sk(skb->sk) : NULL;
- return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
- skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
+ if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) {
+ mtu = READ_ONCE(skb_dst(skb)->dev->mtu);
+ mtu -= lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
+ } else
+ mtu = dst_mtu(skb_dst(skb));
+
+ return mtu;
}
static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
@@ -317,7 +324,7 @@ static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
if (dst_metric_locked(dst, RTAX_MTU)) {
mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
- return mtu;
+ goto out;
}
mtu = IPV6_MIN_MTU;
@@ -327,7 +334,8 @@ static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
mtu = idev->cnf.mtu6;
rcu_read_unlock();
- return mtu;
+out:
+ return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
}
u32 ip6_mtu_from_fib6(const struct fib6_result *res,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6a36ac98476f..78d1e5afc452 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1306,7 +1306,7 @@ INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
- return mtu;
+ goto out;
mtu = READ_ONCE(dst->dev->mtu);
@@ -1315,6 +1315,7 @@ INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
mtu = 576;
}
+out:
mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
return mtu - lwtunnel_headroom(dst->lwtstate, mtu);