From: Steffen Klassert <steffen.klassert@secunet.com>
To: David Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
Steffen Klassert <steffen.klassert@secunet.com>,
<netdev@vger.kernel.org>
Subject: [PATCH 01/13] skbuff: Introduce skb_to_sgvec_nomark to map skb without mark new end
Date: Mon, 24 Feb 2014 10:59:49 +0100 [thread overview]
Message-ID: <1393236001-2445-2-git-send-email-steffen.klassert@secunet.com> (raw)
In-Reply-To: <1393236001-2445-1-git-send-email-steffen.klassert@secunet.com>
From: Fan Du <fan.du@windriver.com>
As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given sglist
without mark the sg which contain last skb data as the end. So the caller can
mannipulate sg list as will when padding new data after the first call without
calling sg_unmark_end to expend sg list.
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
include/linux/skbuff.h | 2 ++
net/core/skbuff.c | 26 ++++++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f589c9a..c574bf3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -691,6 +691,8 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
unsigned int headroom);
struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
int newtailroom, gfp_t priority);
+int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
+ int offset, int len);
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
int len);
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 5976ef0..f28c379 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3281,6 +3281,32 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
return elt;
}
+/* As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given
+ * sglist without mark the sg which contain last skb data as the end.
+ * So the caller can mannipulate sg list as will when padding new data after
+ * the first call without calling sg_unmark_end to expend sg list.
+ *
+ * Scenario to use skb_to_sgvec_nomark:
+ * 1. sg_init_table
+ * 2. skb_to_sgvec_nomark(payload1)
+ * 3. skb_to_sgvec_nomark(payload2)
+ *
+ * This is equivalent to:
+ * 1. sg_init_table
+ * 2. skb_to_sgvec(payload1)
+ * 3. sg_unmark_end
+ * 4. skb_to_sgvec(payload2)
+ *
+ * When mapping mutilple payload conditionally, skb_to_sgvec_nomark
+ * is more preferable.
+ */
+int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
+ int offset, int len)
+{
+ return __skb_to_sgvec(skb, sg, offset, len);
+}
+EXPORT_SYMBOL_GPL(skb_to_sgvec_nomark);
+
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
{
int nsg = __skb_to_sgvec(skb, sg, offset, len);
--
1.7.9.5
next prev parent reply other threads:[~2014-02-24 10:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-24 9:59 pull request (net-next): ipsec-next 2014-02-24 Steffen Klassert
2014-02-24 9:59 ` Steffen Klassert [this message]
2014-02-24 9:59 ` [PATCH 02/13] {IPv4,xfrm} Add ESN support for AH egress part Steffen Klassert
2014-02-24 9:59 ` [PATCH 03/13] {IPv4,xfrm} Add ESN support for AH ingress part Steffen Klassert
2014-02-24 9:59 ` [PATCH 04/13] {IPv6,xfrm} Add ESN support for AH egress part Steffen Klassert
2014-02-24 9:59 ` [PATCH 05/13] {IPv6,xfrm} Add ESN support for AH ingress part Steffen Klassert
2014-02-24 9:59 ` [PATCH 06/13] xfrm: Don't prohibit AH from using ESN feature Steffen Klassert
2014-02-24 9:59 ` [PATCH 07/13] flowcache: Make flow cache name space aware Steffen Klassert
2014-02-24 9:59 ` [PATCH 08/13] flowcache: Bring net/core/flow.c under IPsec maintain scope Steffen Klassert
2014-02-24 9:59 ` [PATCH 09/13] xfrm: avoid creating temporary SA when there are no listeners Steffen Klassert
2014-02-24 9:59 ` [PATCH 10/13] ipsec: add support of limited SA dump Steffen Klassert
2014-02-24 9:59 ` [PATCH 11/13] xfrm: Remove caching of xfrm_policy_sk_bundles Steffen Klassert
2014-02-24 10:00 ` [PATCH 12/13] pfkey: fix SADB_X_EXT_FILTER length check Steffen Klassert
2014-02-24 10:00 ` [PATCH 13/13] xfrm: Cleanup error handling of xfrm_state_clone Steffen Klassert
2014-02-24 23:17 ` pull request (net-next): ipsec-next 2014-02-24 David Miller
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