[net-next,v2,3/4] net: Support GRO/GSO fraglist chaining.
diff mbox series

Message ID 20200124082218.2572-4-steffen.klassert@secunet.com
State Changes Requested
Delegated to: David Miller
Headers show
Series
  • Support fraglist GRO/GSO
Related show

Commit Message

Steffen Klassert Jan. 24, 2020, 8:22 a.m. UTC
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.klassert@secunet.com>
---
 include/linux/netdevice.h |  4 +-
 include/linux/skbuff.h    |  2 +
 net/core/dev.c            |  2 +-
 net/core/skbuff.c         | 91 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 97 insertions(+), 2 deletions(-)

Comments

Willem de Bruijn Jan. 24, 2020, 9:17 p.m. UTC | #1
On Fri, Jan 24, 2020 at 3:23 AM Steffen Klassert
<steffen.klassert@secunet.com> wrote:
>
> 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.klassert@secunet.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>

Patch
diff mbox series

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f8c2d1227433..4c4264c3d5fd 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2322,7 +2322,8 @@  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;
@@ -2690,6 +2691,7 @@  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 5ac5cb1befef..af78046a32b2 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3530,6 +3530,8 @@  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 0dcabd3753d9..07518ed17c2b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3249,7 +3249,7 @@  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 48a7029529c9..864cb9e9622f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3639,6 +3639,97 @@  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);
+
+		 __copy_skb_header(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