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authorAlexander Duyck <aduyck@mirantis.com>2016-04-05 09:13:39 -0700
committerDavid S. Miller <davem@davemloft.net>2016-04-07 16:56:33 -0400
commita0ca153f98db8cf25298565a09e11fe9d82846ad (patch)
tree5f7773cd6e2dbf30f3af97194a8b7d04b99fd1a0 /net
parent0a1a37b6d62e6864a77a82e925217c720f91f963 (diff)
downloadlinux-sh-a0ca153f98db8cf25298565a09e11fe9d82846ad.tar.gz
GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU
This patch fixes an issue I found in which we were dropping frames if we had enabled checksums on GRE headers that were encapsulated by either FOU or GUE. Without this patch I was barely able to get 1 Gb/s of throughput. With this patch applied I am now at least getting around 6 Gb/s. The issue is due to the fact that with FOU or GUE applied we do not provide a transport offset pointing to the GRE header, nor do we offload it in software as the GRE header is completely skipped by GSO and treated like a VXLAN or GENEVE type header. As such we need to prevent the stack from generating it and also prevent GRE from generating it via any interface we create. Fixes: c3483384ee511 ("gro: Allow tunnel stacking in the case of FOU/GUE") Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c1
-rw-r--r--net/ipv4/fou.c6
-rw-r--r--net/ipv4/gre_offload.c8
-rw-r--r--net/ipv4/ip_gre.c13
4 files changed, 25 insertions, 3 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index b9bcbe77d913..77a71cd68535 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4439,6 +4439,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
NAPI_GRO_CB(skb)->flush = 0;
NAPI_GRO_CB(skb)->free = 0;
NAPI_GRO_CB(skb)->encap_mark = 0;
+ NAPI_GRO_CB(skb)->is_fou = 0;
NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
/* Setup for GRO checksum validation */
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 5a94aea280d3..a39068b4a4d9 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -203,6 +203,9 @@ static struct sk_buff **fou_gro_receive(struct sk_buff **head,
*/
NAPI_GRO_CB(skb)->encap_mark = 0;
+ /* Flag this frame as already having an outer encap header */
+ NAPI_GRO_CB(skb)->is_fou = 1;
+
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
@@ -368,6 +371,9 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
*/
NAPI_GRO_CB(skb)->encap_mark = 0;
+ /* Flag this frame as already having an outer encap header */
+ NAPI_GRO_CB(skb)->is_fou = 1;
+
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[guehdr->proto_ctype]);
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index c47539d04b88..6a5bd4317866 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -150,6 +150,14 @@ static struct sk_buff **gre_gro_receive(struct sk_buff **head,
if ((greh->flags & ~(GRE_KEY|GRE_CSUM)) != 0)
goto out;
+ /* We can only support GRE_CSUM if we can track the location of
+ * the GRE header. In the case of FOU/GUE we cannot because the
+ * outer UDP header displaces the GRE header leaving us in a state
+ * of limbo.
+ */
+ if ((greh->flags & GRE_CSUM) && NAPI_GRO_CB(skb)->is_fou)
+ goto out;
+
type = greh->protocol;
rcu_read_lock();
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 31936d387cfd..af5d1f38217f 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -862,9 +862,16 @@ static void __gre_tunnel_init(struct net_device *dev)
dev->hw_features |= GRE_FEATURES;
if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
- /* TCP offload with GRE SEQ is not supported. */
- dev->features |= NETIF_F_GSO_SOFTWARE;
- dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+ /* TCP offload with GRE SEQ is not supported, nor
+ * can we support 2 levels of outer headers requiring
+ * an update.
+ */
+ if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
+ (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
+ dev->features |= NETIF_F_GSO_SOFTWARE;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+ }
+
/* Can use a lockless transmit, unless we generate
* output sequences
*/