@@ -3337,7 +3337,8 @@ struct skb_gso_cb {
int encap_level;
__u16 csum_start;
};
-#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
+#define SKB_SGO_CB_OFFSET 32
+#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
{
@@ -2512,6 +2512,8 @@ static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
*
* It may return NULL if the skb requires no segmentation. This is
* only possible when GSO is used for verifying header integrity.
+ *
+ * Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
*/
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
netdev_features_t features, bool tx_path)
@@ -2526,6 +2528,9 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
return ERR_PTR(err);
}
+ BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
+ sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
+
SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
SKB_GSO_CB(skb)->encap_level = 0;
@@ -240,6 +240,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb,
* from host network stack.
*/
features = netif_skb_features(skb);
+ BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
if (IS_ERR_OR_NULL(segs)) {
kfree_skb(skb);
@@ -336,12 +336,10 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
unsigned short gso_type = skb_shinfo(skb)->gso_type;
struct sw_flow_key later_key;
struct sk_buff *segs, *nskb;
- struct ovs_skb_cb ovs_cb;
int err;
- ovs_cb = *OVS_CB(skb);
+ BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_SGO_CB_OFFSET);
segs = __skb_gso_segment(skb, NETIF_F_SG, false);
- *OVS_CB(skb) = ovs_cb;
if (IS_ERR(segs))
return PTR_ERR(segs);
if (segs == NULL)
@@ -359,7 +357,6 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
/* Queue all of the segments. */
skb = segs;
do {
- *OVS_CB(skb) = ovs_cb;
if (gso_type & SKB_GSO_UDP && skb != segs)
key = &later_key;
@@ -165,6 +165,8 @@ static int xfrm_output_gso(struct sock *sk, struct sk_buff *skb)
{
struct sk_buff *segs;
+ BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
+ BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
segs = skb_gso_segment(skb, 0);
kfree_skb(skb);
if (IS_ERR(segs))