[linux-block.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>

struct seq_file;

/* MPTCP sk_buff extension data */
struct mptcp_ext {
	union {
		u64	data_ack;
		u32	data_ack32;
	};
	u64		data_seq;
	u32		subflow_seq;
	u16		data_len;
	__sum16		csum;
	u8		use_map:1,
			dsn64:1,
			data_fin:1,
			use_ack:1,
			ack64:1,
			mpc_map:1,
			frozen:1,
			reset_transient:1;
	u8		reset_reason:4;
};

#define MPTCP_RM_IDS_MAX	8

struct mptcp_rm_list {
	u8 ids[MPTCP_RM_IDS_MAX];
	u8 nr;
};

struct mptcp_addr_info {
	u8			id;
	sa_family_t		family;
	__be16			port;
	union {
		struct in_addr	addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		struct in6_addr	addr6;
#endif
	};
};

struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
	u16 suboptions;
	u64 sndr_key;
	u64 rcvr_key;
	u64 ahmac;
	struct mptcp_addr_info addr;
	struct mptcp_rm_list rm_list;
	u8 join_id;
	u8 backup;
	u8 reset_reason:4;
	u8 reset_transient:1;
	u32 nonce;
	u64 thmac;
	u32 token;
	u8 hmac[20];
	struct mptcp_ext ext_copy;
#endif
};

#ifdef CONFIG_MPTCP
extern struct request_sock_ops mptcp_subflow_request_sock_ops;

void mptcp_init(void);

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return tcp_sk(sk)->is_mptcp;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
}

void mptcp_space(const struct sock *ssk, int *space, int *full_space);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
		       unsigned int *size, struct mptcp_out_options *opts);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
			  struct mptcp_out_options *opts);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
			       unsigned int *size, unsigned int remaining,
			       struct mptcp_out_options *opts);
void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);

void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
			 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 void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
	struct mptcp_ext *from_ext;

	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	if (!from_ext)
		return;

	from_ext->frozen = 1;
	skb_ext_copy(to, from);
}

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));
}

void mptcp_seq_show(struct seq_file *seq);
int mptcp_subflow_init_cookie_req(struct request_sock *req,
				  const struct sock *sk_listener,
				  struct sk_buff *skb);

__be32 mptcp_get_reset_option(const struct sk_buff *skb);

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
{
	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
		return mptcp_get_reset_option(skb);

	return htonl(0u);
}
#else

static inline void mptcp_init(void)
{
}

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return false;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return false;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return false;
}

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

static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
				     unsigned int *size,
				     struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_synack_options(const struct request_sock *req,
					unsigned int *size,
					struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_established_options(struct sock *sk,
					     struct sk_buff *skb,
					     unsigned int *size,
					     unsigned int remaining,
					     struct mptcp_out_options *opts)
{
	return false;
}

static inline void mptcp_incoming_options(struct sock *sk,
					  struct sk_buff *skb)
{
}

static inline void mptcp_skb_ext_move(struct sk_buff *to,
				      const struct sk_buff *from)
{
}

static inline void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
}

static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
					  const struct sk_buff *from)
{
	return true;
}

static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
static inline void mptcp_seq_show(struct seq_file *seq) { }

static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
						const struct sock *sk_listener,
						struct sk_buff *skb)
{
	return 0; /* TCP fallback */
}

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return htonl(0u); }
#endif /* CONFIG_MPTCP */

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#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>
3ee17bc7 MM	14
fc518953 FW	15	struct seq_file;
fc518953 FW	16
3ee17bc7 MM	17	/* MPTCP sk_buff extension data */
3ee17bc7 MM	18	struct mptcp_ext {
a0c1d0ea CP	19	union {
	20	u64 data_ack;
	21	u32 data_ack32;
	22	};
3ee17bc7 MM	23	u64 data_seq;
	24	u32 subflow_seq;
	25	u16 data_len;
d0cc2987	26	__sum16 csum;
3ee17bc7 MM	27	u8 use_map:1,
	28	dsn64:1,
	29	data_fin:1,
	30	use_ack:1,
	31	ack64:1,
cc7972ea	32	mpc_map:1,
5a369ca6	33	frozen:1,
dc87efdb FW	34	reset_transient:1;
dc87efdb FW	35	u8 reset_reason:4;
3ee17bc7 MM	36	};
3ee17bc7 MM	37
6445e17a GT	38	#define MPTCP_RM_IDS_MAX 8
	39
	40	struct mptcp_rm_list {
	41	u8 ids[MPTCP_RM_IDS_MAX];
	42	u8 nr;
	43	};
	44
30f60bae GT	45	struct mptcp_addr_info {
	46	u8 id;
	47	sa_family_t family;
	48	__be16 port;
	49	union {
	50	struct in_addr addr;
	51	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	52	struct in6_addr addr6;
	53	#endif
	54	};
	55	};
	56
eda7acdd PK	57	struct mptcp_out_options {
	58	#if IS_ENABLED(CONFIG_MPTCP)
	59	u16 suboptions;
	60	u64 sndr_key;
	61	u64 rcvr_key;
3df523ab	62	u64 ahmac;
30f60bae	63	struct mptcp_addr_info addr;
6445e17a	64	struct mptcp_rm_list rm_list;
f296234c PK	65	u8 join_id;
f296234c PK	66	u8 backup;
dc87efdb FW	67	u8 reset_reason:4;
dc87efdb FW	68	u8 reset_transient:1;
f296234c PK	69	u32 nonce;
f296234c PK	70	u64 thmac;
ec3edaa7 PK	71	u32 token;
ec3edaa7 PK	72	u8 hmac[20];
6d0060f6	73	struct mptcp_ext ext_copy;
eda7acdd PK	74	#endif
	75	};
	76
85712484	77	#ifdef CONFIG_MPTCP
08b8d080	78	extern struct request_sock_ops mptcp_subflow_request_sock_ops;
85712484	79
f870fa0b MM	80	void mptcp_init(void);
f870fa0b MM	81
cec37a6e PK	82	static inline bool sk_is_mptcp(const struct sock *sk)
	83	{
	84	return tcp_sk(sk)->is_mptcp;
	85	}
	86
	87	static inline bool rsk_is_mptcp(const struct request_sock *req)
	88	{
	89	return tcp_rsk(req)->is_mptcp;
	90	}
	91
90bf4513 PA	92	static inline bool rsk_drop_req(const struct request_sock *req)
	93	{
	94	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	95	}
	96
071c8ed6	97	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	98	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	99	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	100	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	101	struct mptcp_out_options *opts);
	102	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	103	unsigned int *size, unsigned int remaining,
	104	struct mptcp_out_options *opts);
77d0cab9	105	void mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	106
fa3fe2b1 FW	107	void mptcp_write_options(__be32 ptr, const struct tcp_sock tp,
fa3fe2b1 FW	108	struct mptcp_out_options *opts);
eda7acdd	109
85712484 MM	110	/* move the skb extension owership, with the assumption that 'to' is
	111	* newly allocated
	112	*/
	113	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	114	struct sk_buff *from)
	115	{
	116	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	117	return;
	118
	119	if (WARN_ON_ONCE(to->active_extensions))
	120	skb_ext_put(to);
	121
	122	to->active_extensions = from->active_extensions;
	123	to->extensions = from->extensions;
	124	from->active_extensions = 0;
	125	}
	126
5a369ca6 PA	127	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	128	struct sk_buff *from)
	129	{
	130	struct mptcp_ext *from_ext;
	131
	132	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	133	if (!from_ext)
	134	return;
	135
	136	from_ext->frozen = 1;
	137	skb_ext_copy(to, from);
	138	}
	139
85712484 MM	140	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	141	const struct mptcp_ext *from_ext)
	142	{
	143	/* MPTCP always clears the ext when adding it to the skb, so
	144	* holes do not bother us here
	145	*/
	146	return !from_ext \|\|
	147	(to_ext && from_ext &&
	148	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	149	}
	150
	151	/* check if skbs can be collapsed.
	152	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	153	* mapping, or if the extension of @to is the same as @from.
	154	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	155	*/
	156	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	157	const struct sk_buff *from)
	158	{
	159	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	160	skb_ext_find(from, SKB_EXT_MPTCP));
	161	}
	162
fc518953	163	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	164	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	165	const struct sock *sk_listener,
	166	struct sk_buff *skb);
dc87efdb FW	167
	168	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	169
	170	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	171	{
	172	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	173	return mptcp_get_reset_option(skb);
	174
	175	return htonl(0u);
	176	}
85712484 MM	177	#else
85712484 MM	178
f870fa0b MM	179	static inline void mptcp_init(void)
	180	{
	181	}
	182
cec37a6e PK	183	static inline bool sk_is_mptcp(const struct sock *sk)
	184	{
	185	return false;
	186	}
	187
	188	static inline bool rsk_is_mptcp(const struct request_sock *req)
	189	{
	190	return false;
	191	}
	192
90bf4513 PA	193	static inline bool rsk_drop_req(const struct request_sock *req)
	194	{
	195	return false;
	196	}
	197
cc7972ea CP	198	static inline void mptcp_parse_option(const struct sk_buff *skb,
cc7972ea CP	199	const unsigned char *ptr, int opsize,
eda7acdd PK	200	struct tcp_options_received *opt_rx)
	201	{
	202	}
	203
cc7972ea CP	204	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	205	unsigned int *size,
cec37a6e PK	206	struct mptcp_out_options *opts)
	207	{
	208	return false;
	209	}
	210
cec37a6e PK	211	static inline bool mptcp_synack_options(const struct request_sock *req,
	212	unsigned int *size,
	213	struct mptcp_out_options *opts)
	214	{
	215	return false;
	216	}
	217
	218	static inline bool mptcp_established_options(struct sock *sk,
	219	struct sk_buff *skb,
	220	unsigned int *size,
	221	unsigned int remaining,
	222	struct mptcp_out_options *opts)
	223	{
	224	return false;
	225	}
	226
648ef4b8	227	static inline void mptcp_incoming_options(struct sock *sk,
77d0cab9	228	struct sk_buff *skb)
648ef4b8 MM	229	{
	230	}
	231
85712484 MM	232	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	233	const struct sk_buff *from)
	234	{
	235	}
	236
5a369ca6 PA	237	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	238	struct sk_buff *from)
	239	{
	240	}
	241
85712484 MM	242	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	243	const struct sk_buff *from)
	244	{
	245	return true;
	246	}
	247
071c8ed6	248	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	249	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	250
	251	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	252	const struct sock *sk_listener,
	253	struct sk_buff *skb)
	254	{
	255	return 0; /* TCP fallback */
	256	}
dc87efdb FW	257
dc87efdb FW	258	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	259	#endif /* CONFIG_MPTCP */
f870fa0b MM	260
	261	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	262	int mptcpv6_init(void);
31484d56	263	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	264	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	265	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	266	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	267	#endif
f870fa0b MM	268
3ee17bc7	269	#endif /* __NET_MPTCP_H */