tunnels: Don't apply GRO to multiple layers of encapsulation.
When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.
No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.
UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.
Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross <jesse@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 9659233..0fefba6 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1380,6 +1380,19 @@
return pp;
}
+static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
+ struct sk_buff *skb)
+{
+ if (NAPI_GRO_CB(skb)->encap_mark) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+
+ NAPI_GRO_CB(skb)->encap_mark = 1;
+
+ return inet_gro_receive(head, skb);
+}
+
#define SECONDS_PER_DAY 86400
/* inet_current_timestamp - Return IP network timestamp
@@ -1682,7 +1695,7 @@
static const struct net_offload ipip_offload = {
.callbacks = {
.gso_segment = inet_gso_segment,
- .gro_receive = inet_gro_receive,
+ .gro_receive = ipip_gro_receive,
.gro_complete = ipip_gro_complete,
},
};
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 540866d..dd03161 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -126,6 +126,11 @@
struct packet_offload *ptype;
__be16 type;
+ if (NAPI_GRO_CB(skb)->encap_mark)
+ goto out;
+
+ NAPI_GRO_CB(skb)->encap_mark = 1;
+
off = skb_gro_offset(skb);
hlen = off + sizeof(*greh);
greh = skb_gro_header_fast(skb, off);
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 8a3405a..8007f73 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -311,14 +311,14 @@
unsigned int off = skb_gro_offset(skb);
int flush = 1;
- if (NAPI_GRO_CB(skb)->udp_mark ||
+ if (NAPI_GRO_CB(skb)->encap_mark ||
(skb->ip_summed != CHECKSUM_PARTIAL &&
NAPI_GRO_CB(skb)->csum_cnt == 0 &&
!NAPI_GRO_CB(skb)->csum_valid))
goto out;
- /* mark that this skb passed once through the udp gro layer */
- NAPI_GRO_CB(skb)->udp_mark = 1;
+ /* mark that this skb passed once through the tunnel gro layer */
+ NAPI_GRO_CB(skb)->encap_mark = 1;
rcu_read_lock();
uo_priv = rcu_dereference(udp_offload_base);