diff options
Diffstat (limited to 'include/net/ip.h')
| -rw-r--r-- | include/net/ip.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/net/ip.h b/include/net/ip.h index 04ebe7bf54c6..d61c26ab4ee8 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -439,12 +439,18 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, bool forwarding) { struct net *net = dev_net(dst->dev); + unsigned int mtu; if (net->ipv4.sysctl_ip_fwd_use_pmtu || ip_mtu_locked(dst) || !forwarding) return dst_mtu(dst); + /* 'forwarding = true' case should always honour route mtu */ + mtu = dst_metric_raw(dst, RTAX_MTU); + if (mtu) + return mtu; + return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU); } |