[linux.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 MPTCPOPT_HMAC_LEN	20
#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[MPTCPOPT_HMAC_LEN];
		};
	};
#endif
};

#define MPTCP_SCHED_NAME_MAX	16
#define MPTCP_SUBFLOWS_MAX	8

struct mptcp_sched_data {
	bool	reinject;
	u8	subflows;
	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
};

struct mptcp_sched_ops {
	int (*get_subflow)(struct mptcp_sock *msk,
			   struct mptcp_sched_data *data);

	char			name[MPTCP_SCHED_NAME_MAX];
	struct module		*owner;
	struct list_head	list;

	void (*init)(struct mptcp_sock *msk);
	void (*release)(struct mptcp_sock *msk);
} ____cacheline_aligned_in_smp;

#ifdef CONFIG_MPTCP
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(struct tcphdr *th, __be32 *ptr, 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);
struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
					       struct sock *sk_listener,
					       bool attach_listener);

__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 struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
							     struct sock *sk_listener,
							     bool attach_listener)
{
	return NULL;
}

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

#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
#else
static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
#endif

#if !IS_ENABLED(CONFIG_MPTCP)
struct mptcp_sock { };
#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
f7657ff4	42	#define MPTCPOPT_HMAC_LEN 20
6445e17a GT	43	#define MPTCP_RM_IDS_MAX 8
	44
	45	struct mptcp_rm_list {
	46	u8 ids[MPTCP_RM_IDS_MAX];
	47	u8 nr;
	48	};
	49
30f60bae GT	50	struct mptcp_addr_info {
	51	u8 id;
	52	sa_family_t family;
	53	__be16 port;
	54	union {
	55	struct in_addr addr;
	56	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	57	struct in6_addr addr6;
	58	#endif
	59	};
	60	};
	61
eda7acdd PK	62	struct mptcp_out_options {
	63	#if IS_ENABLED(CONFIG_MPTCP)
	64	u16 suboptions;
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;
d7b26908 PA	72	union {
	73	struct {
	74	u64 sndr_key;
	75	u64 rcvr_key;
f7cc8890 DC	76	u64 data_seq;
	77	u32 subflow_seq;
	78	u16 data_len;
	79	__sum16 csum;
d7b26908 PA	80	};
	81	struct {
	82	struct mptcp_addr_info addr;
	83	u64 ahmac;
	84	};
c25aeb4e GT	85	struct {
	86	struct mptcp_ext ext_copy;
	87	u64 fail_seq;
	88	};
d7b26908 PA	89	struct {
	90	u32 nonce;
	91	u32 token;
	92	u64 thmac;
f7657ff4	93	u8 hmac[MPTCPOPT_HMAC_LEN];
d7b26908 PA	94	};
d7b26908 PA	95	};
eda7acdd PK	96	#endif
	97	};
	98
740ebe35 GT	99	#define MPTCP_SCHED_NAME_MAX 16
	100	#define MPTCP_SUBFLOWS_MAX 8
	101
	102	struct mptcp_sched_data {
	103	bool reinject;
	104	u8 subflows;
	105	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
	106	};
	107
	108	struct mptcp_sched_ops {
	109	int (get_subflow)(struct mptcp_sock msk,
	110	struct mptcp_sched_data *data);
	111
	112	char name[MPTCP_SCHED_NAME_MAX];
	113	struct module *owner;
	114	struct list_head list;
	115
	116	void (init)(struct mptcp_sock msk);
	117	void (release)(struct mptcp_sock msk);
	118	} ____cacheline_aligned_in_smp;
	119
85712484	120	#ifdef CONFIG_MPTCP
f870fa0b MM	121	void mptcp_init(void);
f870fa0b MM	122
cec37a6e PK	123	static inline bool sk_is_mptcp(const struct sock *sk)
	124	{
	125	return tcp_sk(sk)->is_mptcp;
	126	}
	127
	128	static inline bool rsk_is_mptcp(const struct request_sock *req)
	129	{
	130	return tcp_rsk(req)->is_mptcp;
	131	}
	132
90bf4513 PA	133	static inline bool rsk_drop_req(const struct request_sock *req)
	134	{
	135	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	136	}
	137
071c8ed6	138	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	139	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	140	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	141	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	142	struct mptcp_out_options *opts);
	143	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	144	unsigned int *size, unsigned int remaining,
	145	struct mptcp_out_options *opts);
6787b7e3	146	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	147
ea66758c	148	void mptcp_write_options(struct tcphdr th, __be32 ptr, struct tcp_sock *tp,
fa3fe2b1	149	struct mptcp_out_options *opts);
eda7acdd	150
61bc6e82 FW	151	void mptcp_diag_fill_info(struct mptcp_sock msk, struct mptcp_info info);
61bc6e82 FW	152
85712484 MM	153	/* move the skb extension owership, with the assumption that 'to' is
	154	* newly allocated
	155	*/
	156	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	157	struct sk_buff *from)
	158	{
	159	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	160	return;
	161
	162	if (WARN_ON_ONCE(to->active_extensions))
	163	skb_ext_put(to);
	164
	165	to->active_extensions = from->active_extensions;
	166	to->extensions = from->extensions;
	167	from->active_extensions = 0;
	168	}
	169
5a369ca6 PA	170	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	171	struct sk_buff *from)
	172	{
	173	struct mptcp_ext *from_ext;
	174
	175	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	176	if (!from_ext)
	177	return;
	178
	179	from_ext->frozen = 1;
	180	skb_ext_copy(to, from);
	181	}
	182
85712484 MM	183	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	184	const struct mptcp_ext *from_ext)
	185	{
	186	/* MPTCP always clears the ext when adding it to the skb, so
	187	* holes do not bother us here
	188	*/
	189	return !from_ext \|\|
	190	(to_ext && from_ext &&
	191	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	192	}
	193
	194	/* check if skbs can be collapsed.
	195	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	196	* mapping, or if the extension of @to is the same as @from.
	197	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	198	*/
	199	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	200	const struct sk_buff *from)
	201	{
	202	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	203	skb_ext_find(from, SKB_EXT_MPTCP));
	204	}
	205
fc518953	206	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	207	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	208	const struct sock *sk_listener,
	209	struct sk_buff *skb);
3fff8818 MB	210	struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	211	struct sock *sk_listener,
	212	bool attach_listener);
dc87efdb FW	213
	214	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	215
	216	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	217	{
	218	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	219	return mptcp_get_reset_option(skb);
	220
	221	return htonl(0u);
	222	}
85712484 MM	223	#else
85712484 MM	224
f870fa0b MM	225	static inline void mptcp_init(void)
	226	{
	227	}
	228
cec37a6e PK	229	static inline bool sk_is_mptcp(const struct sock *sk)
	230	{
	231	return false;
	232	}
	233
	234	static inline bool rsk_is_mptcp(const struct request_sock *req)
	235	{
	236	return false;
	237	}
	238
90bf4513 PA	239	static inline bool rsk_drop_req(const struct request_sock *req)
	240	{
	241	return false;
	242	}
	243
cc7972ea CP	244	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	245	unsigned int *size,
cec37a6e PK	246	struct mptcp_out_options *opts)
	247	{
	248	return false;
	249	}
	250
cec37a6e PK	251	static inline bool mptcp_synack_options(const struct request_sock *req,
	252	unsigned int *size,
	253	struct mptcp_out_options *opts)
	254	{
	255	return false;
	256	}
	257
	258	static inline bool mptcp_established_options(struct sock *sk,
	259	struct sk_buff *skb,
	260	unsigned int *size,
	261	unsigned int remaining,
	262	struct mptcp_out_options *opts)
	263	{
	264	return false;
	265	}
	266
6787b7e3	267	static inline bool mptcp_incoming_options(struct sock *sk,
77d0cab9	268	struct sk_buff *skb)
648ef4b8	269	{
6787b7e3	270	return true;
648ef4b8 MM	271	}
648ef4b8 MM	272
85712484 MM	273	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	274	const struct sk_buff *from)
	275	{
	276	}
	277
5a369ca6 PA	278	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	279	struct sk_buff *from)
	280	{
	281	}
	282
85712484 MM	283	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	284	const struct sk_buff *from)
	285	{
	286	return true;
	287	}
	288
071c8ed6	289	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	290	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	291
	292	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	293	const struct sock *sk_listener,
	294	struct sk_buff *skb)
	295	{
	296	return 0; /* TCP fallback */
	297	}
dc87efdb	298
3fff8818 MB	299	static inline struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	300	struct sock *sk_listener,
	301	bool attach_listener)
	302	{
	303	return NULL;
	304	}
	305
dc87efdb	306	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	307	#endif /* CONFIG_MPTCP */
f870fa0b MM	308
	309	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	310	int mptcpv6_init(void);
31484d56	311	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	312	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	313	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	314	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	315	#endif
f870fa0b MM	316
3bc253c2 GT	317	#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
	318	struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk);
	319	#else
	320	static inline struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk) { return NULL; }
	321	#endif
	322
f1d41f77 JO	323	#if !IS_ENABLED(CONFIG_MPTCP)
	324	struct mptcp_sock { };
	325	#endif
	326
3ee17bc7	327	#endif /* __NET_MPTCP_H */