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authorStefano Brivio <sbrivio@redhat.com>2018-10-12 23:53:59 +0200
committerDavid S. Miller <davem@davemloft.net>2018-10-17 21:51:13 -0700
commit6b4f92af3d59e882d3ba04c44a815266890d188f (patch)
tree8446305611f6d7e76b1470f1ca91f8bdb822b7bf
parentgeneve, vxlan: Don't check skb_dst() twice (diff)
downloadlinux-dev-6b4f92af3d59e882d3ba04c44a815266890d188f.tar.xz
linux-dev-6b4f92af3d59e882d3ba04c44a815266890d188f.zip
geneve, vxlan: Don't set exceptions if skb->len < mtu
We shouldn't abuse exceptions: if the destination MTU is already higher than what we're transmitting, no exception should be created. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/geneve.c7
-rw-r--r--drivers/net/vxlan.c4
-rw-r--r--include/net/dst.h10
3 files changed, 15 insertions, 6 deletions
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 61c4bfbeb41c..493cd382b8aa 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -830,8 +830,8 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
if (IS_ERR(rt))
return PTR_ERR(rt);
- skb_dst_update_pmtu(skb, dst_mtu(&rt->dst) -
- GENEVE_IPV4_HLEN - info->options_len);
+ 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) {
@@ -872,8 +872,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
if (IS_ERR(dst))
return PTR_ERR(dst);
- skb_dst_update_pmtu(skb, dst_mtu(dst) -
- GENEVE_IPV6_HLEN - info->options_len);
+ 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 22e0ce592e07..27bd586b94b0 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2194,7 +2194,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
}
ndst = &rt->dst;
- skb_dst_update_pmtu(skb, dst_mtu(ndst) - VXLAN_HEADROOM);
+ skb_tunnel_check_pmtu(skb, ndst, VXLAN_HEADROOM);
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
@@ -2231,7 +2231,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
goto out_unlock;
}
- skb_dst_update_pmtu(skb, dst_mtu(ndst) - VXLAN6_HEADROOM);
+ 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 7f735e76ca73..6cf0870414c7 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -527,4 +527,14 @@ static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
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 */