[PATCH 3.13.y-ckt 57/57] net: gso: use feature flag argument in all protocol gso handlers

[Kamal Mostafa]

3.13.11-ckt27 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Florian Westphal <fw@xxxxxxxxx>

[ Upstream commit 1e16aa3ddf863c6b9f37eddf52503230a62dedb3 ]

skb_gso_segment() has a 'features' argument representing offload features
available to the output path.

A few handlers, e.g. GRE, instead re-fetch the features of skb->dev and use
those instead of the provided ones when handing encapsulation/tunnels.

Depending on dev->hw_enc_features of the output device skb_gso_segment() can
then return NULL even when the caller has disabled all GSO feature bits,
as segmentation of inner header thinks device will take care of segmentation.

This e.g. affects the tbf scheduler, which will silently drop GRE-encap GSO skbs
that did not fit the remaining token quota as the segmentation does not work
when device supports corresponding hw offload capabilities.

Cc: Pravin B Shelar <pshelar@xxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[jay.vosburgh: backported to 3.14. ]
Signed-off-by: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 net/ipv4/af_inet.c     | 2 +-
 net/ipv4/gre_offload.c | 2 +-
 net/ipv4/udp.c         | 2 +-
 net/ipv6/ip6_offload.c | 2 +-
 net/mpls/mpls_gso.c    | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 7d2d135..7dd59a8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1294,7 +1294,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 
 	encap = SKB_GSO_CB(skb)->encap_level > 0;
 	if (encap)
-		features = skb->dev->hw_enc_features & netif_skb_features(skb);
+		features &= skb->dev->hw_enc_features;
 	SKB_GSO_CB(skb)->encap_level += ihl;
 
 	skb_reset_transport_header(skb);
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 2cd02f3..f70d768 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -72,7 +72,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
 	skb->mac_len = skb_inner_network_offset(skb);
 
 	/* segment inner packet. */
-	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
+	enc_features = skb->dev->hw_enc_features & features;
 	segs = skb_mac_gso_segment(skb, enc_features);
 	if (!segs || IS_ERR(segs)) {
 		skb_gso_error_unwind(skb, protocol, ghl, mac_offset, mac_len);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 78899fa..4e9921b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2517,7 +2517,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
 	skb->protocol = htons(ETH_P_TEB);
 
 	/* segment inner packet. */
-	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
+	enc_features = skb->dev->hw_enc_features & features;
 	segs = skb_mac_gso_segment(skb, enc_features);
 	if (!segs || IS_ERR(segs)) {
 		skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 6762299..3a70036 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -112,7 +112,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 
 	encap = SKB_GSO_CB(skb)->encap_level > 0;
 	if (encap)
-		features = skb->dev->hw_enc_features & netif_skb_features(skb);
+		features &= skb->dev->hw_enc_features;
 	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
 
 	ipv6h = ipv6_hdr(skb);
diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index 851cd88..0c970cb 100644
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -47,7 +47,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
 	__skb_push(skb, skb->mac_len);
 
 	/* Segment inner packet. */
-	mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
+	mpls_features = skb->dev->mpls_features & features;
 	segs = skb_mac_gso_segment(skb, mpls_features);
 
 
-- 
1.9.1

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