[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,
			csum_reqd:1;
};

#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;
	struct mptcp_rm_list rm_list;
	u8 join_id;
	u8 backup;
	u8 reset_reason:4,
	   reset_transient:1,
	   csum_reqd:1,
	   allow_join_id0:1;
	union {
		struct {
			u64 sndr_key;
			u64 rcvr_key;
		};
		struct {
			struct mptcp_addr_info addr;
			u64 ahmac;
		};
		struct mptcp_ext ext_copy;
		struct {
			u32 nonce;
			u32 token;
			u64 thmac;
			u8 hmac[20];
		};
	};
#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);
bool 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 bool mptcp_incoming_options(struct sock *sk,
					  struct sk_buff *skb)
{
	return true;
}

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	34	reset_transient:1;
208e8f66 GT	35	u8 reset_reason:4,
208e8f66 GT	36	csum_reqd:1;
3ee17bc7 MM	37	};
3ee17bc7 MM	38
6445e17a GT	39	#define MPTCP_RM_IDS_MAX 8
	40
	41	struct mptcp_rm_list {
	42	u8 ids[MPTCP_RM_IDS_MAX];
	43	u8 nr;
	44	};
	45
30f60bae GT	46	struct mptcp_addr_info {
	47	u8 id;
	48	sa_family_t family;
	49	__be16 port;
	50	union {
	51	struct in_addr addr;
	52	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	53	struct in6_addr addr6;
	54	#endif
	55	};
	56	};
	57
eda7acdd PK	58	struct mptcp_out_options {
	59	#if IS_ENABLED(CONFIG_MPTCP)
	60	u16 suboptions;
6445e17a	61	struct mptcp_rm_list rm_list;
f296234c PK	62	u8 join_id;
f296234c PK	63	u8 backup;
06fe1719 GT	64	u8 reset_reason:4,
06fe1719 GT	65	reset_transient:1,
bab6b88e GT	66	csum_reqd:1,
bab6b88e GT	67	allow_join_id0:1;
d7b26908 PA	68	union {
	69	struct {
	70	u64 sndr_key;
	71	u64 rcvr_key;
	72	};
	73	struct {
	74	struct mptcp_addr_info addr;
	75	u64 ahmac;
	76	};
	77	struct mptcp_ext ext_copy;
	78	struct {
	79	u32 nonce;
	80	u32 token;
	81	u64 thmac;
	82	u8 hmac[20];
	83	};
	84	};
eda7acdd PK	85	#endif
	86	};
	87
85712484	88	#ifdef CONFIG_MPTCP
08b8d080	89	extern struct request_sock_ops mptcp_subflow_request_sock_ops;
85712484	90
f870fa0b MM	91	void mptcp_init(void);
f870fa0b MM	92
cec37a6e PK	93	static inline bool sk_is_mptcp(const struct sock *sk)
	94	{
	95	return tcp_sk(sk)->is_mptcp;
	96	}
	97
	98	static inline bool rsk_is_mptcp(const struct request_sock *req)
	99	{
	100	return tcp_rsk(req)->is_mptcp;
	101	}
	102
90bf4513 PA	103	static inline bool rsk_drop_req(const struct request_sock *req)
	104	{
	105	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	106	}
	107
071c8ed6	108	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	109	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	110	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	111	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	112	struct mptcp_out_options *opts);
	113	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	114	unsigned int *size, unsigned int remaining,
	115	struct mptcp_out_options *opts);
6787b7e3	116	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	117
fa3fe2b1 FW	118	void mptcp_write_options(__be32 ptr, const struct tcp_sock tp,
fa3fe2b1 FW	119	struct mptcp_out_options *opts);
eda7acdd	120
85712484 MM	121	/* move the skb extension owership, with the assumption that 'to' is
	122	* newly allocated
	123	*/
	124	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	125	struct sk_buff *from)
	126	{
	127	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	128	return;
	129
	130	if (WARN_ON_ONCE(to->active_extensions))
	131	skb_ext_put(to);
	132
	133	to->active_extensions = from->active_extensions;
	134	to->extensions = from->extensions;
	135	from->active_extensions = 0;
	136	}
	137
5a369ca6 PA	138	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	139	struct sk_buff *from)
	140	{
	141	struct mptcp_ext *from_ext;
	142
	143	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	144	if (!from_ext)
	145	return;
	146
	147	from_ext->frozen = 1;
	148	skb_ext_copy(to, from);
	149	}
	150
85712484 MM	151	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	152	const struct mptcp_ext *from_ext)
	153	{
	154	/* MPTCP always clears the ext when adding it to the skb, so
	155	* holes do not bother us here
	156	*/
	157	return !from_ext \|\|
	158	(to_ext && from_ext &&
	159	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	160	}
	161
	162	/* check if skbs can be collapsed.
	163	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	164	* mapping, or if the extension of @to is the same as @from.
	165	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	166	*/
	167	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	168	const struct sk_buff *from)
	169	{
	170	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	171	skb_ext_find(from, SKB_EXT_MPTCP));
	172	}
	173
fc518953	174	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	175	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	176	const struct sock *sk_listener,
	177	struct sk_buff *skb);
dc87efdb FW	178
	179	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	180
	181	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	182	{
	183	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	184	return mptcp_get_reset_option(skb);
	185
	186	return htonl(0u);
	187	}
85712484 MM	188	#else
85712484 MM	189
f870fa0b MM	190	static inline void mptcp_init(void)
	191	{
	192	}
	193
cec37a6e PK	194	static inline bool sk_is_mptcp(const struct sock *sk)
	195	{
	196	return false;
	197	}
	198
	199	static inline bool rsk_is_mptcp(const struct request_sock *req)
	200	{
	201	return false;
	202	}
	203
90bf4513 PA	204	static inline bool rsk_drop_req(const struct request_sock *req)
	205	{
	206	return false;
	207	}
	208
cc7972ea CP	209	static inline void mptcp_parse_option(const struct sk_buff *skb,
cc7972ea CP	210	const unsigned char *ptr, int opsize,
eda7acdd PK	211	struct tcp_options_received *opt_rx)
	212	{
	213	}
	214
cc7972ea CP	215	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	216	unsigned int *size,
cec37a6e PK	217	struct mptcp_out_options *opts)
	218	{
	219	return false;
	220	}
	221
cec37a6e PK	222	static inline bool mptcp_synack_options(const struct request_sock *req,
	223	unsigned int *size,
	224	struct mptcp_out_options *opts)
	225	{
	226	return false;
	227	}
	228
	229	static inline bool mptcp_established_options(struct sock *sk,
	230	struct sk_buff *skb,
	231	unsigned int *size,
	232	unsigned int remaining,
	233	struct mptcp_out_options *opts)
	234	{
	235	return false;
	236	}
	237
6787b7e3	238	static inline bool mptcp_incoming_options(struct sock *sk,
77d0cab9	239	struct sk_buff *skb)
648ef4b8	240	{
6787b7e3	241	return true;
648ef4b8 MM	242	}
648ef4b8 MM	243
85712484 MM	244	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	245	const struct sk_buff *from)
	246	{
	247	}
	248
5a369ca6 PA	249	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	250	struct sk_buff *from)
	251	{
	252	}
	253
85712484 MM	254	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	255	const struct sk_buff *from)
	256	{
	257	return true;
	258	}
	259
071c8ed6	260	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	261	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	262
	263	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	264	const struct sock *sk_listener,
	265	struct sk_buff *skb)
	266	{
	267	return 0; /* TCP fallback */
	268	}
dc87efdb FW	269
dc87efdb FW	270	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	271	#endif /* CONFIG_MPTCP */
f870fa0b MM	272
	273	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	274	int mptcpv6_init(void);
31484d56	275	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	276	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	277	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	278	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	279	#endif
f870fa0b MM	280
3ee17bc7	281	#endif /* __NET_MPTCP_H */