This patch adds the core functions to chain/unchain
GSO skbs at the frag_list pointer. This also adds
a new GSO type SKB_GSO_FRAGLIST and a is_flist
flag to napi_gro_cb which indicates that this
flow will be GROed by fraglist chaining.
Signed-off-by: Steffen Klassert <steffen.klass...@secunet.com>
---
include/linux/netdevice.h | 4 +-
include/linux/skbuff.h | 2 +
net/core/dev.c | 2 +-
net/core/skbuff.c | 106 ++++++++++++++++++++++++++++++++++++++
4 files changed, 112 insertions(+), 2 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4917cf513bd1..d037e31a1acb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2306,7 +2306,8 @@ struct napi_gro_cb {
/* Number of gro_receive callbacks this packet already went through */
u8 recursion_counter:4;
- /* 1 bit hole */
+ /* GRO is done by frag_list pointer chaining. */
+ u8 is_flist:1;
/* used to support CHECKSUM_COMPLETE for tunneling protocols */
__wsum csum;
@@ -2656,6 +2657,7 @@ struct net_device *dev_get_by_napi_id(unsigned int
napi_id);
int netdev_get_name(struct net *net, char *name, int ifindex);
int dev_restart(struct net_device *dev);
int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
+int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb);
static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
{
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c72540813ea7..3d5fd0a0eea7 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3511,6 +3511,8 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet);
bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
+struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t
features,
+ unsigned int offset);
struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
int skb_ensure_writable(struct sk_buff *skb, int write_len);
int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
diff --git a/net/core/dev.c b/net/core/dev.c
index cc0bbec0f1d7..f2a66198154d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3109,7 +3109,7 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
segs = skb_mac_gso_segment(skb, features);
- if (unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
+ if (segs != skb && unlikely(skb_needs_check(skb, tx_path) &&
!IS_ERR(segs)))
skb_warn_bad_offload(skb);
return segs;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2b40b5a9425b..3ff56677a6fb 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3638,6 +3638,112 @@ static inline skb_frag_t
skb_head_frag_to_page_desc(struct sk_buff *frag_skb)
return head_frag;
}
+struct sk_buff *skb_segment_list(struct sk_buff *skb,
+ netdev_features_t features,
+ unsigned int offset)
+{
+ struct sk_buff *list_skb = skb_shinfo(skb)->frag_list;
+ unsigned int tnl_hlen = skb_tnl_header_len(skb);
+ unsigned int delta_truesize = 0;
+ unsigned int delta_len = 0;
+ struct sk_buff *tail = NULL;
+ struct sk_buff *nskb;
+
+ skb_push(skb, -skb_network_offset(skb) + offset);
+
+ skb_shinfo(skb)->frag_list = NULL;
+
+ do {
+ nskb = list_skb;
+ list_skb = list_skb->next;
+
+ if (!tail)
+ skb->next = nskb;
+ else
+ tail->next = nskb;
+
+ tail = nskb;
+
+ delta_len += nskb->len;
+ delta_truesize += nskb->truesize;
+
+ skb_push(nskb, -skb_network_offset(nskb) + offset);
+
+ if (!secpath_exists(nskb))
+ __skb_ext_copy(nskb, skb);
+
+ memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
+
+ nskb->ip_summed = skb->ip_summed;
+ nskb->csum_valid = skb->csum_valid;
+ nskb->tstamp = skb->tstamp;
+ nskb->dev = skb->dev;
+ nskb->queue_mapping = skb->queue_mapping;
+
+ nskb->mac_len = skb->mac_len;
+ nskb->mac_header = skb->mac_header;
+ nskb->transport_header = skb->transport_header;
+ nskb->network_header = skb->network_header;
+ skb_dst_copy(nskb, skb);
+
+ skb_headers_offset_update(nskb, skb_headroom(nskb) -
skb_headroom(skb));
+ skb_copy_from_linear_data_offset(skb, -tnl_hlen,
+ nskb->data - tnl_hlen,
+ offset + tnl_hlen);
+
+ if (skb_needs_linearize(nskb, features) &&
+ __skb_linearize(nskb))
+ goto err_linearize;
+
+ } while (list_skb);
+
+ skb->truesize = skb->truesize - delta_truesize;
+ skb->data_len = skb->data_len - delta_len;
+ skb->len = skb->len - delta_len;
+
+ skb_gso_reset(skb);
+
+ skb->prev = tail;
+
+ if (skb_needs_linearize(skb, features) &&
+ __skb_linearize(skb))
+ goto err_linearize;
+
+ skb_get(skb);
+
+ return skb;
+
+err_linearize:
+ kfree_skb_list(skb->next);
+ skb->next = NULL;
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(skb_segment_list);
+
+int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
+{
+ if (unlikely(p->len + skb->len >= 65536))
+ return -E2BIG;
+
+ if (NAPI_GRO_CB(p)->last == p)
+ skb_shinfo(p)->frag_list = skb;
+ else
+ NAPI_GRO_CB(p)->last->next = skb;
+
+ skb_pull(skb, skb_gro_offset(skb));
+
+ NAPI_GRO_CB(p)->last = skb;
+ NAPI_GRO_CB(p)->count++;
+ p->data_len += skb->len;
+ p->truesize += skb->truesize;
+ p->len += skb->len;
+
+ NAPI_GRO_CB(skb)->same_flow = 1;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(skb_gro_receive_list);
+
/**
* skb_segment - Perform protocol segmentation on skb.
* @head_skb: buffer to segment
--
2.17.1
