[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 mptcp_info;
struct mptcp_sock;
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,
			infinite_map: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;
			u64 data_seq;
			u32 subflow_seq;
			u16 data_len;
			__sum16 csum;
		};
		struct {
			struct mptcp_addr_info addr;
			u64 ahmac;
		};
		struct {
			struct mptcp_ext ext_copy;
			u64 fail_seq;
		};
		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);

void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);

/* 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 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
61bc6e82 FW	15	struct mptcp_info;
61bc6e82 FW	16	struct mptcp_sock;
fc518953 FW	17	struct seq_file;
fc518953 FW	18
3ee17bc7 MM	19	/* MPTCP sk_buff extension data */
3ee17bc7 MM	20	struct mptcp_ext {
a0c1d0ea CP	21	union {
	22	u64 data_ack;
	23	u32 data_ack32;
	24	};
3ee17bc7 MM	25	u64 data_seq;
	26	u32 subflow_seq;
	27	u16 data_len;
d0cc2987	28	__sum16 csum;
3ee17bc7 MM	29	u8 use_map:1,
	30	dsn64:1,
	31	data_fin:1,
	32	use_ack:1,
	33	ack64:1,
cc7972ea	34	mpc_map:1,
5a369ca6	35	frozen:1,
dc87efdb	36	reset_transient:1;
208e8f66	37	u8 reset_reason:4,
1e39e5a3 GT	38	csum_reqd:1,
1e39e5a3 GT	39	infinite_map:1;
3ee17bc7 MM	40	};
3ee17bc7 MM	41
6445e17a GT	42	#define MPTCP_RM_IDS_MAX 8
	43
	44	struct mptcp_rm_list {
	45	u8 ids[MPTCP_RM_IDS_MAX];
	46	u8 nr;
	47	};
	48
30f60bae GT	49	struct mptcp_addr_info {
	50	u8 id;
	51	sa_family_t family;
	52	__be16 port;
	53	union {
	54	struct in_addr addr;
	55	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	56	struct in6_addr addr6;
	57	#endif
	58	};
	59	};
	60
eda7acdd PK	61	struct mptcp_out_options {
	62	#if IS_ENABLED(CONFIG_MPTCP)
	63	u16 suboptions;
6445e17a	64	struct mptcp_rm_list rm_list;
f296234c PK	65	u8 join_id;
f296234c PK	66	u8 backup;
06fe1719 GT	67	u8 reset_reason:4,
06fe1719 GT	68	reset_transient:1,
bab6b88e GT	69	csum_reqd:1,
bab6b88e GT	70	allow_join_id0:1;
d7b26908 PA	71	union {
	72	struct {
	73	u64 sndr_key;
	74	u64 rcvr_key;
f7cc8890 DC	75	u64 data_seq;
	76	u32 subflow_seq;
	77	u16 data_len;
	78	__sum16 csum;
d7b26908 PA	79	};
	80	struct {
	81	struct mptcp_addr_info addr;
	82	u64 ahmac;
	83	};
c25aeb4e GT	84	struct {
	85	struct mptcp_ext ext_copy;
	86	u64 fail_seq;
	87	};
d7b26908 PA	88	struct {
	89	u32 nonce;
	90	u32 token;
	91	u64 thmac;
	92	u8 hmac[20];
	93	};
	94	};
eda7acdd PK	95	#endif
	96	};
	97
85712484	98	#ifdef CONFIG_MPTCP
08b8d080	99	extern struct request_sock_ops mptcp_subflow_request_sock_ops;
85712484	100
f870fa0b MM	101	void mptcp_init(void);
f870fa0b MM	102
cec37a6e PK	103	static inline bool sk_is_mptcp(const struct sock *sk)
	104	{
	105	return tcp_sk(sk)->is_mptcp;
	106	}
	107
	108	static inline bool rsk_is_mptcp(const struct request_sock *req)
	109	{
	110	return tcp_rsk(req)->is_mptcp;
	111	}
	112
90bf4513 PA	113	static inline bool rsk_drop_req(const struct request_sock *req)
	114	{
	115	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	116	}
	117
071c8ed6	118	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	119	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	120	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	121	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	122	struct mptcp_out_options *opts);
	123	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	124	unsigned int *size, unsigned int remaining,
	125	struct mptcp_out_options *opts);
6787b7e3	126	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	127
fa3fe2b1 FW	128	void mptcp_write_options(__be32 ptr, const struct tcp_sock tp,
fa3fe2b1 FW	129	struct mptcp_out_options *opts);
eda7acdd	130
61bc6e82 FW	131	void mptcp_diag_fill_info(struct mptcp_sock msk, struct mptcp_info info);
61bc6e82 FW	132
85712484 MM	133	/* move the skb extension owership, with the assumption that 'to' is
	134	* newly allocated
	135	*/
	136	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	137	struct sk_buff *from)
	138	{
	139	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	140	return;
	141
	142	if (WARN_ON_ONCE(to->active_extensions))
	143	skb_ext_put(to);
	144
	145	to->active_extensions = from->active_extensions;
	146	to->extensions = from->extensions;
	147	from->active_extensions = 0;
	148	}
	149
5a369ca6 PA	150	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	151	struct sk_buff *from)
	152	{
	153	struct mptcp_ext *from_ext;
	154
	155	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	156	if (!from_ext)
	157	return;
	158
	159	from_ext->frozen = 1;
	160	skb_ext_copy(to, from);
	161	}
	162
85712484 MM	163	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	164	const struct mptcp_ext *from_ext)
	165	{
	166	/* MPTCP always clears the ext when adding it to the skb, so
	167	* holes do not bother us here
	168	*/
	169	return !from_ext \|\|
	170	(to_ext && from_ext &&
	171	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	172	}
	173
	174	/* check if skbs can be collapsed.
	175	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	176	* mapping, or if the extension of @to is the same as @from.
	177	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	178	*/
	179	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	180	const struct sk_buff *from)
	181	{
	182	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	183	skb_ext_find(from, SKB_EXT_MPTCP));
	184	}
	185
fc518953	186	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	187	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	188	const struct sock *sk_listener,
	189	struct sk_buff *skb);
dc87efdb FW	190
	191	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	192
	193	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	194	{
	195	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	196	return mptcp_get_reset_option(skb);
	197
	198	return htonl(0u);
	199	}
85712484 MM	200	#else
85712484 MM	201
f870fa0b MM	202	static inline void mptcp_init(void)
	203	{
	204	}
	205
cec37a6e PK	206	static inline bool sk_is_mptcp(const struct sock *sk)
	207	{
	208	return false;
	209	}
	210
	211	static inline bool rsk_is_mptcp(const struct request_sock *req)
	212	{
	213	return false;
	214	}
	215
90bf4513 PA	216	static inline bool rsk_drop_req(const struct request_sock *req)
	217	{
	218	return false;
	219	}
	220
cc7972ea CP	221	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	222	unsigned int *size,
cec37a6e PK	223	struct mptcp_out_options *opts)
	224	{
	225	return false;
	226	}
	227
cec37a6e PK	228	static inline bool mptcp_synack_options(const struct request_sock *req,
	229	unsigned int *size,
	230	struct mptcp_out_options *opts)
	231	{
	232	return false;
	233	}
	234
	235	static inline bool mptcp_established_options(struct sock *sk,
	236	struct sk_buff *skb,
	237	unsigned int *size,
	238	unsigned int remaining,
	239	struct mptcp_out_options *opts)
	240	{
	241	return false;
	242	}
	243
6787b7e3	244	static inline bool mptcp_incoming_options(struct sock *sk,
77d0cab9	245	struct sk_buff *skb)
648ef4b8	246	{
6787b7e3	247	return true;
648ef4b8 MM	248	}
648ef4b8 MM	249
85712484 MM	250	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	251	const struct sk_buff *from)
	252	{
	253	}
	254
5a369ca6 PA	255	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	256	struct sk_buff *from)
	257	{
	258	}
	259
85712484 MM	260	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	261	const struct sk_buff *from)
	262	{
	263	return true;
	264	}
	265
071c8ed6	266	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	267	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	268
	269	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	270	const struct sock *sk_listener,
	271	struct sk_buff *skb)
	272	{
	273	return 0; /* TCP fallback */
	274	}
dc87efdb FW	275
dc87efdb FW	276	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	277	#endif /* CONFIG_MPTCP */
f870fa0b MM	278
	279	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	280	int mptcpv6_init(void);
31484d56	281	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	282	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	283	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	284	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	285	#endif
f870fa0b MM	286
3ee17bc7	287	#endif /* __NET_MPTCP_H */