[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>

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;
	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,
	   reset_transient:1,
	   csum_reqd:1,
	   allow_join_id0:1;
	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);
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;
	61	u64 sndr_key;
	62	u64 rcvr_key;
3df523ab	63	u64 ahmac;
30f60bae	64	struct mptcp_addr_info addr;
6445e17a	65	struct mptcp_rm_list rm_list;
f296234c PK	66	u8 join_id;
f296234c PK	67	u8 backup;
06fe1719 GT	68	u8 reset_reason:4,
06fe1719 GT	69	reset_transient:1,
bab6b88e GT	70	csum_reqd:1,
bab6b88e GT	71	allow_join_id0:1;
f296234c PK	72	u32 nonce;
f296234c PK	73	u64 thmac;
ec3edaa7 PK	74	u32 token;
ec3edaa7 PK	75	u8 hmac[20];
6d0060f6	76	struct mptcp_ext ext_copy;
eda7acdd PK	77	#endif
	78	};
	79
85712484	80	#ifdef CONFIG_MPTCP
08b8d080	81	extern struct request_sock_ops mptcp_subflow_request_sock_ops;
85712484	82
f870fa0b MM	83	void mptcp_init(void);
f870fa0b MM	84
cec37a6e PK	85	static inline bool sk_is_mptcp(const struct sock *sk)
	86	{
	87	return tcp_sk(sk)->is_mptcp;
	88	}
	89
	90	static inline bool rsk_is_mptcp(const struct request_sock *req)
	91	{
	92	return tcp_rsk(req)->is_mptcp;
	93	}
	94
90bf4513 PA	95	static inline bool rsk_drop_req(const struct request_sock *req)
	96	{
	97	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	98	}
	99
071c8ed6	100	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	101	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	102	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	103	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	104	struct mptcp_out_options *opts);
	105	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	106	unsigned int *size, unsigned int remaining,
	107	struct mptcp_out_options *opts);
6787b7e3	108	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	109
fa3fe2b1 FW	110	void mptcp_write_options(__be32 ptr, const struct tcp_sock tp,
fa3fe2b1 FW	111	struct mptcp_out_options *opts);
eda7acdd	112
85712484 MM	113	/* move the skb extension owership, with the assumption that 'to' is
	114	* newly allocated
	115	*/
	116	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	117	struct sk_buff *from)
	118	{
	119	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	120	return;
	121
	122	if (WARN_ON_ONCE(to->active_extensions))
	123	skb_ext_put(to);
	124
	125	to->active_extensions = from->active_extensions;
	126	to->extensions = from->extensions;
	127	from->active_extensions = 0;
	128	}
	129
5a369ca6 PA	130	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	131	struct sk_buff *from)
	132	{
	133	struct mptcp_ext *from_ext;
	134
	135	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	136	if (!from_ext)
	137	return;
	138
	139	from_ext->frozen = 1;
	140	skb_ext_copy(to, from);
	141	}
	142
85712484 MM	143	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	144	const struct mptcp_ext *from_ext)
	145	{
	146	/* MPTCP always clears the ext when adding it to the skb, so
	147	* holes do not bother us here
	148	*/
	149	return !from_ext \|\|
	150	(to_ext && from_ext &&
	151	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	152	}
	153
	154	/* check if skbs can be collapsed.
	155	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	156	* mapping, or if the extension of @to is the same as @from.
	157	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	158	*/
	159	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	160	const struct sk_buff *from)
	161	{
	162	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	163	skb_ext_find(from, SKB_EXT_MPTCP));
	164	}
	165
fc518953	166	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	167	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	168	const struct sock *sk_listener,
	169	struct sk_buff *skb);
dc87efdb FW	170
	171	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	172
	173	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	174	{
	175	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	176	return mptcp_get_reset_option(skb);
	177
	178	return htonl(0u);
	179	}
85712484 MM	180	#else
85712484 MM	181
f870fa0b MM	182	static inline void mptcp_init(void)
	183	{
	184	}
	185
cec37a6e PK	186	static inline bool sk_is_mptcp(const struct sock *sk)
	187	{
	188	return false;
	189	}
	190
	191	static inline bool rsk_is_mptcp(const struct request_sock *req)
	192	{
	193	return false;
	194	}
	195
90bf4513 PA	196	static inline bool rsk_drop_req(const struct request_sock *req)
	197	{
	198	return false;
	199	}
	200
cc7972ea CP	201	static inline void mptcp_parse_option(const struct sk_buff *skb,
cc7972ea CP	202	const unsigned char *ptr, int opsize,
eda7acdd PK	203	struct tcp_options_received *opt_rx)
	204	{
	205	}
	206
cc7972ea CP	207	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	208	unsigned int *size,
cec37a6e PK	209	struct mptcp_out_options *opts)
	210	{
	211	return false;
	212	}
	213
cec37a6e PK	214	static inline bool mptcp_synack_options(const struct request_sock *req,
	215	unsigned int *size,
	216	struct mptcp_out_options *opts)
	217	{
	218	return false;
	219	}
	220
	221	static inline bool mptcp_established_options(struct sock *sk,
	222	struct sk_buff *skb,
	223	unsigned int *size,
	224	unsigned int remaining,
	225	struct mptcp_out_options *opts)
	226	{
	227	return false;
	228	}
	229
6787b7e3	230	static inline bool mptcp_incoming_options(struct sock *sk,
77d0cab9	231	struct sk_buff *skb)
648ef4b8	232	{
6787b7e3	233	return true;
648ef4b8 MM	234	}
648ef4b8 MM	235
85712484 MM	236	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	237	const struct sk_buff *from)
	238	{
	239	}
	240
5a369ca6 PA	241	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	242	struct sk_buff *from)
	243	{
	244	}
	245
85712484 MM	246	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	247	const struct sk_buff *from)
	248	{
	249	return true;
	250	}
	251
071c8ed6	252	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	253	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	254
	255	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	256	const struct sock *sk_listener,
	257	struct sk_buff *skb)
	258	{
	259	return 0; /* TCP fallback */
	260	}
dc87efdb FW	261
dc87efdb FW	262	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	263	#endif /* CONFIG_MPTCP */
f870fa0b MM	264
	265	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	266	int mptcpv6_init(void);
31484d56	267	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	268	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	269	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	270	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	271	#endif
f870fa0b MM	272
3ee17bc7	273	#endif /* __NET_MPTCP_H */