Merge branch 'geneve-vxlan-mtu'
Stefano Brivio says:
====================
geneve, vxlan: Don't set exceptions if skb->len < mtu
This series fixes the exception abuse described in 2/2, and 1/2
is just a preparatory change to make 2/2 less ugly.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 6acb6b5..493cd38 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -830,12 +830,8 @@
if (IS_ERR(rt))
return PTR_ERR(rt);
- if (skb_dst(skb)) {
- int mtu = dst_mtu(&rt->dst) - GENEVE_IPV4_HLEN -
- info->options_len;
-
- skb_dst_update_pmtu(skb, mtu);
- }
+ skb_tunnel_check_pmtu(skb, &rt->dst,
+ GENEVE_IPV4_HLEN + info->options_len);
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
if (geneve->collect_md) {
@@ -876,11 +872,7 @@
if (IS_ERR(dst))
return PTR_ERR(dst);
- if (skb_dst(skb)) {
- int mtu = dst_mtu(dst) - GENEVE_IPV6_HLEN - info->options_len;
-
- skb_dst_update_pmtu(skb, mtu);
- }
+ skb_tunnel_check_pmtu(skb, dst, GENEVE_IPV6_HLEN + info->options_len);
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
if (geneve->collect_md) {
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 2b8da2b..27bd586 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2194,11 +2194,7 @@
}
ndst = &rt->dst;
- if (skb_dst(skb)) {
- int mtu = dst_mtu(ndst) - VXLAN_HEADROOM;
-
- skb_dst_update_pmtu(skb, mtu);
- }
+ skb_tunnel_check_pmtu(skb, ndst, VXLAN_HEADROOM);
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
@@ -2235,11 +2231,7 @@
goto out_unlock;
}
- if (skb_dst(skb)) {
- int mtu = dst_mtu(ndst) - VXLAN6_HEADROOM;
-
- skb_dst_update_pmtu(skb, mtu);
- }
+ skb_tunnel_check_pmtu(skb, ndst, VXLAN6_HEADROOM);
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
ttl = ttl ? : ip6_dst_hoplimit(ndst);
diff --git a/include/net/dst.h b/include/net/dst.h
index 7f735e7..6cf0870 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -527,4 +527,14 @@
dst->ops->update_pmtu(dst, NULL, skb, mtu);
}
+static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
+ struct dst_entry *encap_dst,
+ int headroom)
+{
+ u32 encap_mtu = dst_mtu(encap_dst);
+
+ if (skb->len > encap_mtu - headroom)
+ skb_dst_update_pmtu(skb, encap_mtu - headroom);
+}
+
#endif /* _NET_DST_H */
