[PATCH net-next 2/3] net: mpls fixes for GSO

Roopa Prabhu
2016-08-11T06:50:50Z

From: David Ahern <dsa@cumulusnetworks.com>

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
---
net/mpls/mpls_gso.c | 24 ++++++++++++++++--------
net/mpls/mpls_iptunnel.c | 7 +++++++
2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index 2055e57..8829ee0 100644
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -22,26 +22,28 @@
static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
+ int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
struct sk_buff *segs = ERR_PTR(-EINVAL);
+ u16 mac_offset = skb->mac_header;
netdev_features_t mpls_features;
__be16 mpls_protocol;
+ u16 mac_len = skb->mac_len;

/* Setup inner SKB. */
mpls_protocol = skb->protocol;
skb->protocol = skb->inner_protocol;

- /* Push back the mac header that skb_mac_gso_segment() has pulled.
- * It will be re-pulled by the call to skb_mac_gso_segment() below
- */
- __skb_push(skb, skb->mac_len);
+ __skb_pull(skb, tnl_hlen);
+ skb->mac_len = skb_inner_network_offset(skb);

/* Segment inner packet. */
mpls_features = skb->dev->mpls_features & features;
segs = skb_mac_gso_segment(skb, mpls_features);
-
-
- /* Restore outer protocol. */
- skb->protocol = mpls_protocol;
+ if (IS_ERR_OR_NULL(segs)) {
+ skb_gso_error_unwind(skb, mpls_protocol, tnl_hlen, mac_offset,
+ mac_len);
+ goto out;
+ }

/* Re-pull the mac header that the call to skb_mac_gso_segment()
* above pulled. It will be re-pushed after returning
@@ -49,6 +51,12 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
*/
__skb_pull(skb, skb->data - skb_mac_header(skb));

+ /* Restore outer protocol. */
+ skb->protocol = mpls_protocol;
+ for (skb = segs; skb; skb = skb->next)
+ skb->protocol = mpls_protocol;
+
+out:
return segs;
}

diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index aed872c..87e035a 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -90,8 +90,15 @@ static int mpls_xmit(struct sk_buff *skb)
if (skb_cow(skb, hh_len + new_header_size))
goto drop;

+ skb_reset_mac_header(skb);
+ skb_reset_inner_headers(skb);
+ skb->encapsulation = 1;
+
skb_push(skb, new_header_size);
+
skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+ skb_set_inner_protocol(skb, skb->protocol);

skb->dev = out_dev;
skb->protocol = htons(ETH_P_MPLS_UC);
--
1.9.1