[linux-2.6-block.git] / net / mptcp / protocol.h

/* SPDX-License-Identifier: GPL-2.0 */
/* Multipath TCP
 *
 * Copyright (c) 2017 - 2019, Intel Corporation.
 */

#ifndef __MPTCP_PROTOCOL_H
#define __MPTCP_PROTOCOL_H

#include <linux/random.h>
#include <net/tcp.h>
#include <net/inet_connection_sock.h>

#define MPTCP_SUPPORTED_VERSION	1

/* MPTCP option bits */
#define OPTION_MPTCP_MPC_SYN	BIT(0)
#define OPTION_MPTCP_MPC_SYNACK	BIT(1)
#define OPTION_MPTCP_MPC_ACK	BIT(2)
#define OPTION_MPTCP_MPJ_SYN	BIT(3)
#define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
#define OPTION_MPTCP_MPJ_ACK	BIT(5)
#define OPTION_MPTCP_ADD_ADDR	BIT(6)
#define OPTION_MPTCP_ADD_ADDR6	BIT(7)
#define OPTION_MPTCP_RM_ADDR	BIT(8)

/* MPTCP option subtypes */
#define MPTCPOPT_MP_CAPABLE	0
#define MPTCPOPT_MP_JOIN	1
#define MPTCPOPT_DSS		2
#define MPTCPOPT_ADD_ADDR	3
#define MPTCPOPT_RM_ADDR	4
#define MPTCPOPT_MP_PRIO	5
#define MPTCPOPT_MP_FAIL	6
#define MPTCPOPT_MP_FASTCLOSE	7

/* MPTCP suboption lengths */
#define TCPOLEN_MPTCP_MPC_SYN		4
#define TCPOLEN_MPTCP_MPC_SYNACK	12
#define TCPOLEN_MPTCP_MPC_ACK		20
#define TCPOLEN_MPTCP_MPC_ACK_DATA	22
#define TCPOLEN_MPTCP_MPJ_SYN		12
#define TCPOLEN_MPTCP_MPJ_SYNACK	16
#define TCPOLEN_MPTCP_MPJ_ACK		24
#define TCPOLEN_MPTCP_DSS_BASE		4
#define TCPOLEN_MPTCP_DSS_ACK32		4
#define TCPOLEN_MPTCP_DSS_ACK64		8
#define TCPOLEN_MPTCP_DSS_MAP32		10
#define TCPOLEN_MPTCP_DSS_MAP64		14
#define TCPOLEN_MPTCP_DSS_CHECKSUM	2
#define TCPOLEN_MPTCP_ADD_ADDR		16
#define TCPOLEN_MPTCP_ADD_ADDR_PORT	18
#define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	10
#define TCPOLEN_MPTCP_ADD_ADDR6		28
#define TCPOLEN_MPTCP_ADD_ADDR6_PORT	30
#define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	22
#define TCPOLEN_MPTCP_PORT_LEN		2
#define TCPOLEN_MPTCP_RM_ADDR_BASE	4

/* MPTCP MP_JOIN flags */
#define MPTCPOPT_BACKUP		BIT(0)
#define MPTCPOPT_HMAC_LEN	20
#define MPTCPOPT_THMAC_LEN	8

/* MPTCP MP_CAPABLE flags */
#define MPTCP_VERSION_MASK	(0x0F)
#define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
#define MPTCP_CAP_EXTENSIBILITY	BIT(6)
#define MPTCP_CAP_HMAC_SHA256	BIT(0)
#define MPTCP_CAP_FLAG_MASK	(0x3F)

/* MPTCP DSS flags */
#define MPTCP_DSS_DATA_FIN	BIT(4)
#define MPTCP_DSS_DSN64		BIT(3)
#define MPTCP_DSS_HAS_MAP	BIT(2)
#define MPTCP_DSS_ACK64		BIT(1)
#define MPTCP_DSS_HAS_ACK	BIT(0)
#define MPTCP_DSS_FLAG_MASK	(0x1F)

/* MPTCP ADD_ADDR flags */
#define MPTCP_ADDR_ECHO		BIT(0)
#define MPTCP_ADDR_IPVERSION_4	4
#define MPTCP_ADDR_IPVERSION_6	6

/* MPTCP socket flags */
#define MPTCP_DATA_READY	0
#define MPTCP_SEND_SPACE	1
#define MPTCP_WORK_RTX		2
#define MPTCP_WORK_EOF		3
#define MPTCP_FALLBACK_DONE	4

struct mptcp_options_received {
	u64	sndr_key;
	u64	rcvr_key;
	u64	data_ack;
	u64	data_seq;
	u32	subflow_seq;
	u16	data_len;
	u16	mp_capable : 1,
		mp_join : 1,
		dss : 1,
		add_addr : 1,
		rm_addr : 1,
		family : 4,
		echo : 1,
		backup : 1;
	u32	token;
	u32	nonce;
	u64	thmac;
	u8	hmac[20];
	u8	join_id;
	u8	use_map:1,
		dsn64:1,
		data_fin:1,
		use_ack:1,
		ack64:1,
		mpc_map:1,
		__unused:2;
	u8	addr_id;
	u8	rm_id;
	union {
		struct in_addr	addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		struct in6_addr	addr6;
#endif
	};
	u64	ahmac;
	u16	port;
};

static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
{
	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
		     ((nib & 0xF) << 8) | field);
}

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

enum mptcp_pm_status {
	MPTCP_PM_ADD_ADDR_RECEIVED,
	MPTCP_PM_ESTABLISHED,
	MPTCP_PM_SUBFLOW_ESTABLISHED,
};

struct mptcp_pm_data {
	struct mptcp_addr_info local;
	struct mptcp_addr_info remote;

	spinlock_t	lock;		/*protects the whole PM data */

	bool		addr_signal;
	bool		server_side;
	bool		work_pending;
	bool		accept_addr;
	bool		accept_subflow;
	u8		add_addr_signaled;
	u8		add_addr_accepted;
	u8		local_addr_used;
	u8		subflows;
	u8		add_addr_signal_max;
	u8		add_addr_accept_max;
	u8		local_addr_max;
	u8		subflows_max;
	u8		status;

	struct		work_struct work;
};

struct mptcp_data_frag {
	struct list_head list;
	u64 data_seq;
	int data_len;
	int offset;
	int overhead;
	struct page *page;
};

/* MPTCP connection sock */
struct mptcp_sock {
	/* inet_connection_sock must be the first member */
	struct inet_connection_sock sk;
	u64		local_key;
	u64		remote_key;
	u64		write_seq;
	u64		ack_seq;
	atomic64_t	snd_una;
	unsigned long	timer_ival;
	u32		token;
	unsigned long	flags;
	bool		can_ack;
	spinlock_t	join_list_lock;
	struct work_struct work;
	struct list_head conn_list;
	struct list_head rtx_queue;
	struct list_head join_list;
	struct skb_ext	*cached_ext;	/* for the next sendmsg */
	struct socket	*subflow; /* outgoing connect/listener/!mp_capable */
	struct sock	*first;
	struct mptcp_pm_data	pm;
};

#define mptcp_for_each_subflow(__msk, __subflow)			\
	list_for_each_entry(__subflow, &((__msk)->conn_list), node)

static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
{
	return (struct mptcp_sock *)sk;
}

static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
{
	struct mptcp_sock *msk = mptcp_sk(sk);

	if (list_empty(&msk->rtx_queue))
		return NULL;

	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
}

static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
{
	struct mptcp_sock *msk = mptcp_sk(sk);

	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
}

struct mptcp_subflow_request_sock {
	struct	tcp_request_sock sk;
	u16	mp_capable : 1,
		mp_join : 1,
		backup : 1;
	u8	local_id;
	u8	remote_id;
	u64	local_key;
	u64	idsn;
	u32	token;
	u32	ssn_offset;
	u64	thmac;
	u32	local_nonce;
	u32	remote_nonce;
	struct mptcp_sock	*msk;
	struct hlist_nulls_node token_node;
};

static inline struct mptcp_subflow_request_sock *
mptcp_subflow_rsk(const struct request_sock *rsk)
{
	return (struct mptcp_subflow_request_sock *)rsk;
}

/* MPTCP subflow context */
struct mptcp_subflow_context {
	struct	list_head node;/* conn_list of subflows */
	u64	local_key;
	u64	remote_key;
	u64	idsn;
	u64	map_seq;
	u32	snd_isn;
	u32	token;
	u32	rel_write_seq;
	u32	map_subflow_seq;
	u32	ssn_offset;
	u32	map_data_len;
	u32	request_mptcp : 1,  /* send MP_CAPABLE */
		request_join : 1,   /* send MP_JOIN */
		request_bkup : 1,
		mp_capable : 1,	    /* remote is MPTCP capable */
		mp_join : 1,	    /* remote is JOINing */
		fully_established : 1,	    /* path validated */
		pm_notified : 1,    /* PM hook called for established status */
		conn_finished : 1,
		map_valid : 1,
		mpc_map : 1,
		backup : 1,
		data_avail : 1,
		rx_eof : 1,
		data_fin_tx_enable : 1,
		use_64bit_ack : 1, /* Set when we received a 64-bit DSN */
		can_ack : 1;	    /* only after processing the remote a key */
	u64	data_fin_tx_seq;
	u32	remote_nonce;
	u64	thmac;
	u32	local_nonce;
	u32	remote_token;
	u8	hmac[MPTCPOPT_HMAC_LEN];
	u8	local_id;
	u8	remote_id;

	struct	sock *tcp_sock;	    /* tcp sk backpointer */
	struct	sock *conn;	    /* parent mptcp_sock */
	const	struct inet_connection_sock_af_ops *icsk_af_ops;
	void	(*tcp_data_ready)(struct sock *sk);
	void	(*tcp_state_change)(struct sock *sk);
	void	(*tcp_write_space)(struct sock *sk);

	struct	rcu_head rcu;
};

static inline struct mptcp_subflow_context *
mptcp_subflow_ctx(const struct sock *sk)
{
	struct inet_connection_sock *icsk = inet_csk(sk);

	/* Use RCU on icsk_ulp_data only for sock diag code */
	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
}

static inline struct sock *
mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
{
	return subflow->tcp_sock;
}

static inline u64
mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
{
	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
		      subflow->ssn_offset -
		      subflow->map_subflow_seq;
}

static inline u64
mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
{
	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
}

int mptcp_is_enabled(struct net *net);
bool mptcp_subflow_data_available(struct sock *sk);
void __init mptcp_subflow_init(void);

/* called with sk socket lock held */
int __mptcp_subflow_connect(struct sock *sk, int ifindex,
			    const struct mptcp_addr_info *loc,
			    const struct mptcp_addr_info *remote);
int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);

static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
					      struct mptcp_subflow_context *ctx)
{
	sk->sk_data_ready = ctx->tcp_data_ready;
	sk->sk_state_change = ctx->tcp_state_change;
	sk->sk_write_space = ctx->tcp_write_space;

	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
}

void __init mptcp_proto_init(void);
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int __init mptcp_proto_v6_init(void);
#endif

struct sock *mptcp_sk_clone(const struct sock *sk,
			    const struct mptcp_options_received *mp_opt,
			    struct request_sock *req);
void mptcp_get_options(const struct sk_buff *skb,
		       struct mptcp_options_received *mp_opt);

void mptcp_finish_connect(struct sock *sk);
void mptcp_data_ready(struct sock *sk, struct sock *ssk);
bool mptcp_finish_join(struct sock *sk);
void mptcp_data_acked(struct sock *sk);
void mptcp_subflow_eof(struct sock *sk);

void __init mptcp_token_init(void);
static inline void mptcp_token_init_request(struct request_sock *req)
{
	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
}

int mptcp_token_new_request(struct request_sock *req);
void mptcp_token_destroy_request(struct request_sock *req);
int mptcp_token_new_connect(struct sock *sk);
void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
			struct mptcp_sock *msk);
struct mptcp_sock *mptcp_token_get_sock(u32 token);
void mptcp_token_destroy(struct mptcp_sock *msk);

void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
{
	/* we might consider a faster version that computes the key as a
	 * hash of some information available in the MPTCP socket. Use
	 * random data at the moment, as it's probably the safest option
	 * in case multiple sockets are opened in different namespaces at
	 * the same time.
	 */
	get_random_bytes(key, sizeof(u64));
	mptcp_crypto_key_sha(*key, token, idsn);
}

void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);

void __init mptcp_pm_init(void);
void mptcp_pm_data_init(struct mptcp_sock *msk);
void mptcp_pm_close(struct mptcp_sock *msk);
void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
void mptcp_pm_fully_established(struct mptcp_sock *msk);
bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
void mptcp_pm_connection_closed(struct mptcp_sock *msk);
void mptcp_pm_subflow_established(struct mptcp_sock *msk,
				  struct mptcp_subflow_context *subflow);
void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
				const struct mptcp_addr_info *addr);

int mptcp_pm_announce_addr(struct mptcp_sock *msk,
			   const struct mptcp_addr_info *addr);
int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);

static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)
{
	return READ_ONCE(msk->pm.addr_signal);
}

static inline unsigned int mptcp_add_addr_len(int family)
{
	if (family == AF_INET)
		return TCPOLEN_MPTCP_ADD_ADDR;
	return TCPOLEN_MPTCP_ADD_ADDR6;
}

bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
			  struct mptcp_addr_info *saddr);
int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);

void __init mptcp_pm_nl_init(void);
void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);

static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
{
	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
}

static inline bool before64(__u64 seq1, __u64 seq2)
{
	return (__s64)(seq1 - seq2) < 0;
}

#define after64(seq2, seq1)	before64(seq1, seq2)

void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);

static inline bool __mptcp_check_fallback(struct mptcp_sock *msk)
{
	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
}

static inline bool mptcp_check_fallback(struct sock *sk)
{
	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	return __mptcp_check_fallback(msk);
}

static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
{
	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
		pr_debug("TCP fallback already done (msk=%p)", msk);
		return;
	}
	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
}

static inline void mptcp_do_fallback(struct sock *sk)
{
	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	__mptcp_do_fallback(msk);
}

#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)

#endif /* __MPTCP_PROTOCOL_H */
Commit	Line	Data
f870fa0b MM	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* Multipath TCP
	3	*
	4	* Copyright (c) 2017 - 2019, Intel Corporation.
	5	*/
	6
	7	#ifndef __MPTCP_PROTOCOL_H
	8	#define __MPTCP_PROTOCOL_H
	9
79c0949e PK	10	#include <linux/random.h>
	11	#include <net/tcp.h>
	12	#include <net/inet_connection_sock.h>
	13
cc7972ea	14	#define MPTCP_SUPPORTED_VERSION 1
eda7acdd PK	15
	16	/* MPTCP option bits */
	17	#define OPTION_MPTCP_MPC_SYN BIT(0)
	18	#define OPTION_MPTCP_MPC_SYNACK BIT(1)
	19	#define OPTION_MPTCP_MPC_ACK BIT(2)
f296234c PK	20	#define OPTION_MPTCP_MPJ_SYN BIT(3)
	21	#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
	22	#define OPTION_MPTCP_MPJ_ACK BIT(5)
3df523ab PK	23	#define OPTION_MPTCP_ADD_ADDR BIT(6)
	24	#define OPTION_MPTCP_ADD_ADDR6 BIT(7)
	25	#define OPTION_MPTCP_RM_ADDR BIT(8)
eda7acdd PK	26
	27	/* MPTCP option subtypes */
	28	#define MPTCPOPT_MP_CAPABLE 0
	29	#define MPTCPOPT_MP_JOIN 1
	30	#define MPTCPOPT_DSS 2
	31	#define MPTCPOPT_ADD_ADDR 3
	32	#define MPTCPOPT_RM_ADDR 4
	33	#define MPTCPOPT_MP_PRIO 5
	34	#define MPTCPOPT_MP_FAIL 6
	35	#define MPTCPOPT_MP_FASTCLOSE 7
	36
	37	/* MPTCP suboption lengths */
cc7972ea	38	#define TCPOLEN_MPTCP_MPC_SYN 4
eda7acdd PK	39	#define TCPOLEN_MPTCP_MPC_SYNACK 12
eda7acdd PK	40	#define TCPOLEN_MPTCP_MPC_ACK 20
cc7972ea	41	#define TCPOLEN_MPTCP_MPC_ACK_DATA 22
f296234c PK	42	#define TCPOLEN_MPTCP_MPJ_SYN 12
	43	#define TCPOLEN_MPTCP_MPJ_SYNACK 16
	44	#define TCPOLEN_MPTCP_MPJ_ACK 24
6d0060f6	45	#define TCPOLEN_MPTCP_DSS_BASE 4
648ef4b8	46	#define TCPOLEN_MPTCP_DSS_ACK32 4
6d0060f6	47	#define TCPOLEN_MPTCP_DSS_ACK64 8
648ef4b8	48	#define TCPOLEN_MPTCP_DSS_MAP32 10
6d0060f6 MM	49	#define TCPOLEN_MPTCP_DSS_MAP64 14
6d0060f6 MM	50	#define TCPOLEN_MPTCP_DSS_CHECKSUM 2
3df523ab PK	51	#define TCPOLEN_MPTCP_ADD_ADDR 16
	52	#define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
	53	#define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
	54	#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
	55	#define TCPOLEN_MPTCP_ADD_ADDR6 28
	56	#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
	57	#define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
	58	#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
	59	#define TCPOLEN_MPTCP_PORT_LEN 2
	60	#define TCPOLEN_MPTCP_RM_ADDR_BASE 4
eda7acdd	61
ec3edaa7	62	/* MPTCP MP_JOIN flags */
f296234c PK	63	#define MPTCPOPT_BACKUP BIT(0)
f296234c PK	64	#define MPTCPOPT_HMAC_LEN 20
ec3edaa7	65	#define MPTCPOPT_THMAC_LEN 8
f296234c	66
eda7acdd PK	67	/* MPTCP MP_CAPABLE flags */
	68	#define MPTCP_VERSION_MASK (0x0F)
	69	#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
	70	#define MPTCP_CAP_EXTENSIBILITY BIT(6)
65492c5a	71	#define MPTCP_CAP_HMAC_SHA256 BIT(0)
eda7acdd PK	72	#define MPTCP_CAP_FLAG_MASK (0x3F)
eda7acdd PK	73
6d0060f6 MM	74	/* MPTCP DSS flags */
	75	#define MPTCP_DSS_DATA_FIN BIT(4)
	76	#define MPTCP_DSS_DSN64 BIT(3)
	77	#define MPTCP_DSS_HAS_MAP BIT(2)
	78	#define MPTCP_DSS_ACK64 BIT(1)
	79	#define MPTCP_DSS_HAS_ACK BIT(0)
648ef4b8 MM	80	#define MPTCP_DSS_FLAG_MASK (0x1F)
648ef4b8 MM	81
3df523ab PK	82	/* MPTCP ADD_ADDR flags */
3df523ab PK	83	#define MPTCP_ADDR_ECHO BIT(0)
3df523ab PK	84	#define MPTCP_ADDR_IPVERSION_4 4
	85	#define MPTCP_ADDR_IPVERSION_6 6
	86
648ef4b8	87	/* MPTCP socket flags */
d99bfed5 FW	88	#define MPTCP_DATA_READY 0
d99bfed5 FW	89	#define MPTCP_SEND_SPACE 1
3b1d6210	90	#define MPTCP_WORK_RTX 2
59832e24	91	#define MPTCP_WORK_EOF 3
e1ff9e82	92	#define MPTCP_FALLBACK_DONE 4
6d0060f6	93
cfde141e PA	94	struct mptcp_options_received {
	95	u64 sndr_key;
	96	u64 rcvr_key;
	97	u64 data_ack;
	98	u64 data_seq;
	99	u32 subflow_seq;
	100	u16 data_len;
	101	u16 mp_capable : 1,
	102	mp_join : 1,
	103	dss : 1,
	104	add_addr : 1,
	105	rm_addr : 1,
	106	family : 4,
	107	echo : 1,
	108	backup : 1;
	109	u32 token;
	110	u32 nonce;
	111	u64 thmac;
	112	u8 hmac[20];
	113	u8 join_id;
	114	u8 use_map:1,
	115	dsn64:1,
	116	data_fin:1,
	117	use_ack:1,
	118	ack64:1,
	119	mpc_map:1,
	120	__unused:2;
	121	u8 addr_id;
	122	u8 rm_id;
	123	union {
	124	struct in_addr addr;
	125	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	126	struct in6_addr addr6;
	127	#endif
	128	};
	129	u64 ahmac;
	130	u16 port;
	131	};
	132
3df523ab PK	133	static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
	134	{
	135	return htonl((TCPOPT_MPTCP << 24) \| (len << 16) \| (subopt << 12) \|
	136	((nib & 0xF) << 8) \| field);
	137	}
	138
1b1c7a0e PK	139	struct mptcp_addr_info {
	140	sa_family_t family;
	141	__be16 port;
	142	u8 id;
	143	union {
	144	struct in_addr addr;
	145	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	146	struct in6_addr addr6;
	147	#endif
	148	};
	149	};
	150
	151	enum mptcp_pm_status {
	152	MPTCP_PM_ADD_ADDR_RECEIVED,
	153	MPTCP_PM_ESTABLISHED,
	154	MPTCP_PM_SUBFLOW_ESTABLISHED,
	155	};
	156
	157	struct mptcp_pm_data {
	158	struct mptcp_addr_info local;
	159	struct mptcp_addr_info remote;
	160
	161	spinlock_t lock; /protects the whole PM data /
	162
	163	bool addr_signal;
	164	bool server_side;
	165	bool work_pending;
	166	bool accept_addr;
	167	bool accept_subflow;
	168	u8 add_addr_signaled;
	169	u8 add_addr_accepted;
	170	u8 local_addr_used;
	171	u8 subflows;
	172	u8 add_addr_signal_max;
	173	u8 add_addr_accept_max;
	174	u8 local_addr_max;
	175	u8 subflows_max;
	176	u8 status;
	177
	178	struct work_struct work;
	179	};
	180
18b683bf PA	181	struct mptcp_data_frag {
	182	struct list_head list;
	183	u64 data_seq;
	184	int data_len;
	185	int offset;
	186	int overhead;
	187	struct page *page;
	188	};
	189
f870fa0b MM	190	/* MPTCP connection sock */
	191	struct mptcp_sock {
	192	/* inet_connection_sock must be the first member */
	193	struct inet_connection_sock sk;
cec37a6e PK	194	u64 local_key;
cec37a6e PK	195	u64 remote_key;
6d0060f6 MM	196	u64 write_seq;
6d0060f6 MM	197	u64 ack_seq;
cc9d2566	198	atomic64_t snd_una;
b51f9b80	199	unsigned long timer_ival;
79c0949e	200	u32 token;
648ef4b8	201	unsigned long flags;
d22f4988	202	bool can_ack;
ec3edaa7	203	spinlock_t join_list_lock;
80992017	204	struct work_struct work;
cec37a6e	205	struct list_head conn_list;
18b683bf	206	struct list_head rtx_queue;
ec3edaa7	207	struct list_head join_list;
6d0060f6	208	struct skb_ext cached_ext; / for the next sendmsg */
f870fa0b	209	struct socket subflow; / outgoing connect/listener/!mp_capable */
8ab183de	210	struct sock *first;
1b1c7a0e	211	struct mptcp_pm_data pm;
f870fa0b MM	212	};
f870fa0b MM	213
cec37a6e PK	214	#define mptcp_for_each_subflow(__msk, __subflow) \
	215	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
	216
f870fa0b MM	217	static inline struct mptcp_sock mptcp_sk(const struct sock sk)
	218	{
	219	return (struct mptcp_sock *)sk;
	220	}
	221
18b683bf PA	222	static inline struct mptcp_data_frag mptcp_rtx_tail(const struct sock sk)
	223	{
	224	struct mptcp_sock *msk = mptcp_sk(sk);
	225
	226	if (list_empty(&msk->rtx_queue))
	227	return NULL;
	228
	229	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
	230	}
	231
7948f6cc FW	232	static inline struct mptcp_data_frag mptcp_rtx_head(const struct sock sk)
	233	{
	234	struct mptcp_sock *msk = mptcp_sk(sk);
	235
a386bc5b	236	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
7948f6cc FW	237	}
7948f6cc FW	238
cec37a6e PK	239	struct mptcp_subflow_request_sock {
cec37a6e PK	240	struct tcp_request_sock sk;
d22f4988	241	u16 mp_capable : 1,
cec37a6e	242	mp_join : 1,
fca5c82c	243	backup : 1;
1b1c7a0e	244	u8 local_id;
f296234c	245	u8 remote_id;
cec37a6e	246	u64 local_key;
79c0949e PK	247	u64 idsn;
79c0949e PK	248	u32 token;
648ef4b8	249	u32 ssn_offset;
f296234c PK	250	u64 thmac;
	251	u32 local_nonce;
	252	u32 remote_nonce;
8fd4de12	253	struct mptcp_sock *msk;
2c5ebd00	254	struct hlist_nulls_node token_node;
cec37a6e PK	255	};
	256
	257	static inline struct mptcp_subflow_request_sock *
	258	mptcp_subflow_rsk(const struct request_sock *rsk)
	259	{
	260	return (struct mptcp_subflow_request_sock *)rsk;
	261	}
	262
2303f994 PK	263	/* MPTCP subflow context */
2303f994 PK	264	struct mptcp_subflow_context {
cec37a6e PK	265	struct list_head node;/* conn_list of subflows */
	266	u64 local_key;
	267	u64 remote_key;
79c0949e	268	u64 idsn;
648ef4b8	269	u64 map_seq;
cc7972ea	270	u32 snd_isn;
79c0949e	271	u32 token;
6d0060f6	272	u32 rel_write_seq;
648ef4b8 MM	273	u32 map_subflow_seq;
	274	u32 ssn_offset;
	275	u32 map_data_len;
cec37a6e	276	u32 request_mptcp : 1, /* send MP_CAPABLE */
ec3edaa7 PK	277	request_join : 1, /* send MP_JOIN */
ec3edaa7 PK	278	request_bkup : 1,
cec37a6e	279	mp_capable : 1, /* remote is MPTCP capable */
f296234c	280	mp_join : 1, /* remote is JOINing */
0be534f5	281	fully_established : 1, /* path validated */
f296234c	282	pm_notified : 1, /* PM hook called for established status */
648ef4b8 MM	283	conn_finished : 1,
648ef4b8 MM	284	map_valid : 1,
d22f4988	285	mpc_map : 1,
f296234c	286	backup : 1,
648ef4b8	287	data_avail : 1,
d22f4988	288	rx_eof : 1,
76c42a29	289	data_fin_tx_enable : 1,
a0c1d0ea	290	use_64bit_ack : 1, /* Set when we received a 64-bit DSN */
d22f4988	291	can_ack : 1; /* only after processing the remote a key */
76c42a29	292	u64 data_fin_tx_seq;
f296234c PK	293	u32 remote_nonce;
	294	u64 thmac;
	295	u32 local_nonce;
ec3edaa7 PK	296	u32 remote_token;
ec3edaa7 PK	297	u8 hmac[MPTCPOPT_HMAC_LEN];
f296234c PK	298	u8 local_id;
f296234c PK	299	u8 remote_id;
648ef4b8	300
2303f994 PK	301	struct sock tcp_sock; / tcp sk backpointer */
2303f994 PK	302	struct sock conn; / parent mptcp_sock */
cec37a6e	303	const struct inet_connection_sock_af_ops *icsk_af_ops;
648ef4b8 MM	304	void (tcp_data_ready)(struct sock sk);
	305	void (tcp_state_change)(struct sock sk);
	306	void (tcp_write_space)(struct sock sk);
	307
2303f994 PK	308	struct rcu_head rcu;
	309	};
	310
	311	static inline struct mptcp_subflow_context *
	312	mptcp_subflow_ctx(const struct sock *sk)
	313	{
	314	struct inet_connection_sock *icsk = inet_csk(sk);
	315
	316	/* Use RCU on icsk_ulp_data only for sock diag code */
	317	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
	318	}
	319
	320	static inline struct sock *
	321	mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
	322	{
	323	return subflow->tcp_sock;
	324	}
	325
648ef4b8 MM	326	static inline u64
	327	mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
	328	{
	329	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
	330	subflow->ssn_offset -
	331	subflow->map_subflow_seq;
	332	}
	333
	334	static inline u64
	335	mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
	336	{
	337	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
	338	}
	339
	340	int mptcp_is_enabled(struct net *net);
	341	bool mptcp_subflow_data_available(struct sock *sk);
d39dceca	342	void __init mptcp_subflow_init(void);
ec3edaa7 PK	343
	344	/* called with sk socket lock held */
	345	int __mptcp_subflow_connect(struct sock *sk, int ifindex,
	346	const struct mptcp_addr_info *loc,
	347	const struct mptcp_addr_info *remote);
2303f994 PK	348	int mptcp_subflow_create_socket(struct sock sk, struct socket *new_sock);
2303f994 PK	349
648ef4b8 MM	350	static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
	351	struct mptcp_subflow_context *ctx)
	352	{
	353	sk->sk_data_ready = ctx->tcp_data_ready;
	354	sk->sk_state_change = ctx->tcp_state_change;
	355	sk->sk_write_space = ctx->tcp_write_space;
	356
	357	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
	358	}
	359
d39dceca	360	void __init mptcp_proto_init(void);
784325e9	361	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
d39dceca	362	int __init mptcp_proto_v6_init(void);
784325e9	363	#endif
648ef4b8	364
fca5c82c	365	struct sock mptcp_sk_clone(const struct sock sk,
cfde141e	366	const struct mptcp_options_received *mp_opt,
fca5c82c	367	struct request_sock *req);
cec37a6e	368	void mptcp_get_options(const struct sk_buff *skb,
cfde141e	369	struct mptcp_options_received *mp_opt);
cec37a6e PK	370
cec37a6e PK	371	void mptcp_finish_connect(struct sock *sk);
2e52213c	372	void mptcp_data_ready(struct sock sk, struct sock ssk);
f296234c	373	bool mptcp_finish_join(struct sock *sk);
b51f9b80	374	void mptcp_data_acked(struct sock *sk);
59832e24	375	void mptcp_subflow_eof(struct sock *sk);
cec37a6e	376
2c5ebd00 PA	377	void __init mptcp_token_init(void);
	378	static inline void mptcp_token_init_request(struct request_sock *req)
	379	{
	380	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
	381	}
	382
79c0949e	383	int mptcp_token_new_request(struct request_sock *req);
2c5ebd00	384	void mptcp_token_destroy_request(struct request_sock *req);
79c0949e	385	int mptcp_token_new_connect(struct sock *sk);
2c5ebd00 PA	386	void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
2c5ebd00 PA	387	struct mptcp_sock *msk);
f296234c	388	struct mptcp_sock *mptcp_token_get_sock(u32 token);
2c5ebd00	389	void mptcp_token_destroy(struct mptcp_sock *msk);
79c0949e PK	390
	391	void mptcp_crypto_key_sha(u64 key, u32 token, u64 idsn);
	392	static inline void mptcp_crypto_key_gen_sha(u64 key, u32 token, u64 *idsn)
	393	{
	394	/* we might consider a faster version that computes the key as a
	395	* hash of some information available in the MPTCP socket. Use
	396	* random data at the moment, as it's probably the safest option
	397	* in case multiple sockets are opened in different namespaces at
	398	* the same time.
	399	*/
	400	get_random_bytes(key, sizeof(u64));
	401	mptcp_crypto_key_sha(*key, token, idsn);
	402	}
	403
3df523ab	404	void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 msg, int len, void hmac);
79c0949e	405
d39dceca	406	void __init mptcp_pm_init(void);
1b1c7a0e	407	void mptcp_pm_data_init(struct mptcp_sock *msk);
926bdeab	408	void mptcp_pm_close(struct mptcp_sock *msk);
1b1c7a0e PK	409	void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
	410	void mptcp_pm_fully_established(struct mptcp_sock *msk);
	411	bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
	412	void mptcp_pm_connection_closed(struct mptcp_sock *msk);
	413	void mptcp_pm_subflow_established(struct mptcp_sock *msk,
	414	struct mptcp_subflow_context *subflow);
	415	void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
	416	void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
	417	const struct mptcp_addr_info *addr);
	418
	419	int mptcp_pm_announce_addr(struct mptcp_sock *msk,
	420	const struct mptcp_addr_info *addr);
	421	int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
	422	int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
	423
	424	static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)
	425	{
	426	return READ_ONCE(msk->pm.addr_signal);
	427	}
	428
	429	static inline unsigned int mptcp_add_addr_len(int family)
	430	{
	431	if (family == AF_INET)
	432	return TCPOLEN_MPTCP_ADD_ADDR;
	433	return TCPOLEN_MPTCP_ADD_ADDR6;
	434	}
	435
	436	bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
	437	struct mptcp_addr_info *saddr);
	438	int mptcp_pm_get_local_id(struct mptcp_sock msk, struct sock_common skc);
	439
d39dceca	440	void __init mptcp_pm_nl_init(void);
01cacb00 PA	441	void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
	442	void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
	443	void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
	444	void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
	445	int mptcp_pm_nl_get_local_id(struct mptcp_sock msk, struct sock_common skc);
	446
6d0060f6 MM	447	static inline struct mptcp_ext mptcp_get_ext(struct sk_buff skb)
	448	{
	449	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
	450	}
	451
648ef4b8 MM	452	static inline bool before64(__u64 seq1, __u64 seq2)
	453	{
	454	return (__s64)(seq1 - seq2) < 0;
	455	}
	456
	457	#define after64(seq2, seq1) before64(seq1, seq2)
	458
5147dfb5 DC	459	void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
5147dfb5 DC	460
e1ff9e82 DC	461	static inline bool __mptcp_check_fallback(struct mptcp_sock *msk)
	462	{
	463	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
	464	}
	465
	466	static inline bool mptcp_check_fallback(struct sock *sk)
	467	{
	468	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
	469	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
	470
	471	return __mptcp_check_fallback(msk);
	472	}
	473
	474	static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
	475	{
	476	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
	477	pr_debug("TCP fallback already done (msk=%p)", msk);
	478	return;
	479	}
	480	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
	481	}
	482
	483	static inline void mptcp_do_fallback(struct sock *sk)
	484	{
	485	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
	486	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
	487
	488	__mptcp_do_fallback(msk);
	489	}
	490
	491	#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
	492
f870fa0b	493	#endif /* __MPTCP_PROTOCOL_H */