[mirror_ubuntu-jammy-kernel.git] / include / net / mptcp.h

/* 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/tcp.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 */
};

struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
	u16 suboptions;
	u64 sndr_key;
	u64 rcvr_key;
#endif
};

#ifdef CONFIG_MPTCP

void mptcp_init(void);

void mptcp_parse_option(const unsigned char *ptr, int opsize,
			struct tcp_options_received *opt_rx);
void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts);

/* 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_init(void)
{
}

static inline void mptcp_parse_option(const unsigned char *ptr, int opsize,
				      struct tcp_options_received *opt_rx)
{
}

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 */

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void)
{
	return 0;
}
#endif

#endif /* __NET_MPTCP_H */
Commit	Line	Data
3ee17bc7 MM	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* Multipath TCP
	4	*
	5	* Copyright (c) 2017 - 2019, Intel Corporation.
	6	*/
	7
	8	#ifndef __NET_MPTCP_H
	9	#define __NET_MPTCP_H
	10
85712484	11	#include <linux/skbuff.h>
eda7acdd	12	#include <linux/tcp.h>
3ee17bc7 MM	13	#include <linux/types.h>
	14
	15	/* MPTCP sk_buff extension data */
	16	struct mptcp_ext {
	17	u64 data_ack;
	18	u64 data_seq;
	19	u32 subflow_seq;
	20	u16 data_len;
	21	u8 use_map:1,
	22	dsn64:1,
	23	data_fin:1,
	24	use_ack:1,
	25	ack64:1,
	26	__unused:3;
	27	/* one byte hole */
	28	};
	29
eda7acdd PK	30	struct mptcp_out_options {
	31	#if IS_ENABLED(CONFIG_MPTCP)
	32	u16 suboptions;
	33	u64 sndr_key;
	34	u64 rcvr_key;
	35	#endif
	36	};
	37
85712484 MM	38	#ifdef CONFIG_MPTCP
85712484 MM	39
f870fa0b MM	40	void mptcp_init(void);
f870fa0b MM	41
eda7acdd PK	42	void mptcp_parse_option(const unsigned char *ptr, int opsize,
	43	struct tcp_options_received *opt_rx);
	44	void mptcp_write_options(__be32 ptr, struct mptcp_out_options opts);
	45
85712484 MM	46	/* move the skb extension owership, with the assumption that 'to' is
	47	* newly allocated
	48	*/
	49	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	50	struct sk_buff *from)
	51	{
	52	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	53	return;
	54
	55	if (WARN_ON_ONCE(to->active_extensions))
	56	skb_ext_put(to);
	57
	58	to->active_extensions = from->active_extensions;
	59	to->extensions = from->extensions;
	60	from->active_extensions = 0;
	61	}
	62
	63	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	64	const struct mptcp_ext *from_ext)
	65	{
	66	/* MPTCP always clears the ext when adding it to the skb, so
	67	* holes do not bother us here
	68	*/
	69	return !from_ext \|\|
	70	(to_ext && from_ext &&
	71	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	72	}
	73
	74	/* check if skbs can be collapsed.
	75	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	76	* mapping, or if the extension of @to is the same as @from.
	77	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	78	*/
	79	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	80	const struct sk_buff *from)
	81	{
	82	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	83	skb_ext_find(from, SKB_EXT_MPTCP));
	84	}
	85
	86	#else
	87
f870fa0b MM	88	static inline void mptcp_init(void)
	89	{
	90	}
	91
eda7acdd PK	92	static inline void mptcp_parse_option(const unsigned char *ptr, int opsize,
	93	struct tcp_options_received *opt_rx)
	94	{
	95	}
	96
85712484 MM	97	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	98	const struct sk_buff *from)
	99	{
	100	}
	101
	102	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	103	const struct sk_buff *from)
	104	{
	105	return true;
	106	}
	107
	108	#endif /* CONFIG_MPTCP */
f870fa0b MM	109
	110	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	111	int mptcpv6_init(void);
	112	#elif IS_ENABLED(CONFIG_IPV6)
	113	static inline int mptcpv6_init(void)
	114	{
	115	return 0;
	116	}
	117	#endif
	118
3ee17bc7	119	#endif /* __NET_MPTCP_H */