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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Multipath TCP
*
* Copyright (c) 2017 - 2019, Intel Corporation.
*/
#ifndef __NET_MPTCP_H
#define __NET_MPTCP_H
#include <linux/skbuff.h>
#include <linux/types.h>
/* MPTCP sk_buff extension data */
struct mptcp_ext {
u64 data_ack;
u64 data_seq;
u32 subflow_seq;
u16 data_len;
u8 use_map:1,
dsn64:1,
data_fin:1,
use_ack:1,
ack64:1,
__unused:3;
/* one byte hole */
};
#ifdef CONFIG_MPTCP
/* move the skb extension owership, with the assumption that 'to' is
* newly allocated
*/
static inline void mptcp_skb_ext_move(struct sk_buff *to,
struct sk_buff *from)
{
if (!skb_ext_exist(from, SKB_EXT_MPTCP))
return;
if (WARN_ON_ONCE(to->active_extensions))
skb_ext_put(to);
to->active_extensions = from->active_extensions;
to->extensions = from->extensions;
from->active_extensions = 0;
}
static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
const struct mptcp_ext *from_ext)
{
/* MPTCP always clears the ext when adding it to the skb, so
* holes do not bother us here
*/
return !from_ext ||
(to_ext && from_ext &&
!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
}
/* check if skbs can be collapsed.
* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
* mapping, or if the extension of @to is the same as @from.
* Collapsing is not possible if @to lacks an extension, but @from carries one.
*/
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
skb_ext_find(from, SKB_EXT_MPTCP));
}
#else
static inline void mptcp_skb_ext_move(struct sk_buff *to,
const struct sk_buff *from)
{
}
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return true;
}
#endif /* CONFIG_MPTCP */
#endif /* __NET_MPTCP_H */
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