diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index d708b66e55cd..85e3455cea25 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -629,8 +629,7 @@ struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst, int headroom, bool reply); -static inline void ip_tunnel_adj_headroom(struct net_device *dev, - unsigned int headroom) +static inline unsigned int ip_tunnel_limit_headroom(unsigned int headroom) { /* we must cap headroom to some upperlimit, else pskb_expand_head * will overflow header offsets in skb_headers_offset_update(). @@ -640,6 +639,14 @@ static inline void ip_tunnel_adj_headroom(struct net_device *dev, if (headroom > max_allowed) headroom = max_allowed; + return headroom; +} + +static inline void ip_tunnel_adj_headroom(struct net_device *dev, + unsigned int headroom) +{ + headroom = ip_tunnel_limit_headroom(headroom); + if (headroom > READ_ONCE(dev->needed_headroom)) WRITE_ONCE(dev->needed_headroom, headroom); } diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 9d114bd575f9..5b1f180485d4 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -317,7 +317,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev) mtu = min(tdev->mtu, IP_MAX_MTU); } - dev->needed_headroom = t_hlen + hlen; + dev->needed_headroom = ip_tunnel_limit_headroom(t_hlen + hlen); mtu -= t_hlen + (dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0); if (mtu < IPV4_MIN_MTU) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 70c171091020..200d0ba1a40e 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -1137,8 +1137,11 @@ static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu, return; if (rt->dst.dev) { - dev->needed_headroom = rt->dst.dev->hard_header_len + - t_hlen; + unsigned int headroom; + + headroom = rt->dst.dev->hard_header_len + t_hlen; + headroom = ip_tunnel_limit_headroom(headroom); + dev->needed_headroom = headroom; if (set_mtu) { int mtu = rt->dst.dev->mtu - t_hlen; diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 6a1b901ecc9b..cc96bb8b706e 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1514,8 +1514,11 @@ static void ip6_tnl_link_config(struct ip6_tnl *t) tdev = __dev_get_by_index(t->net, p->link); if (tdev) { - dev->needed_headroom = tdev->hard_header_len + - tdev->needed_headroom + t_hlen; + unsigned int headroom; + + headroom = tdev->hard_header_len + tdev->needed_headroom; + headroom += t_hlen; + dev->needed_headroom = ip_tunnel_limit_headroom(headroom); mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU); mtu = mtu - t_hlen; diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index a38b24fb8384..19b7fa8d1a2a 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1131,7 +1131,7 @@ static void ipip6_tunnel_bind_dev(struct net_device *dev) WRITE_ONCE(dev->mtu, mtu); hlen = tdev->hard_header_len + tdev->needed_headroom; } - dev->needed_headroom = t_hlen + hlen; + dev->needed_headroom = ip_tunnel_limit_headroom(t_hlen + hlen); } static void ipip6_tunnel_update(struct ip_tunnel *t,