xref: /linux/net/mptcp/protocol.h (revision ec8a42e7343234802b9054874fe01810880289ce)
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 
10 #include <linux/random.h>
11 #include <net/tcp.h>
12 #include <net/inet_connection_sock.h>
13 #include <uapi/linux/mptcp.h>
14 
15 #define MPTCP_SUPPORTED_VERSION	1
16 
17 /* MPTCP option bits */
18 #define OPTION_MPTCP_MPC_SYN	BIT(0)
19 #define OPTION_MPTCP_MPC_SYNACK	BIT(1)
20 #define OPTION_MPTCP_MPC_ACK	BIT(2)
21 #define OPTION_MPTCP_MPJ_SYN	BIT(3)
22 #define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
23 #define OPTION_MPTCP_MPJ_ACK	BIT(5)
24 #define OPTION_MPTCP_ADD_ADDR	BIT(6)
25 #define OPTION_MPTCP_ADD_ADDR6	BIT(7)
26 #define OPTION_MPTCP_RM_ADDR	BIT(8)
27 #define OPTION_MPTCP_FASTCLOSE	BIT(9)
28 #define OPTION_MPTCP_PRIO	BIT(10)
29 
30 /* MPTCP option subtypes */
31 #define MPTCPOPT_MP_CAPABLE	0
32 #define MPTCPOPT_MP_JOIN	1
33 #define MPTCPOPT_DSS		2
34 #define MPTCPOPT_ADD_ADDR	3
35 #define MPTCPOPT_RM_ADDR	4
36 #define MPTCPOPT_MP_PRIO	5
37 #define MPTCPOPT_MP_FAIL	6
38 #define MPTCPOPT_MP_FASTCLOSE	7
39 
40 /* MPTCP suboption lengths */
41 #define TCPOLEN_MPTCP_MPC_SYN		4
42 #define TCPOLEN_MPTCP_MPC_SYNACK	12
43 #define TCPOLEN_MPTCP_MPC_ACK		20
44 #define TCPOLEN_MPTCP_MPC_ACK_DATA	22
45 #define TCPOLEN_MPTCP_MPJ_SYN		12
46 #define TCPOLEN_MPTCP_MPJ_SYNACK	16
47 #define TCPOLEN_MPTCP_MPJ_ACK		24
48 #define TCPOLEN_MPTCP_DSS_BASE		4
49 #define TCPOLEN_MPTCP_DSS_ACK32		4
50 #define TCPOLEN_MPTCP_DSS_ACK64		8
51 #define TCPOLEN_MPTCP_DSS_MAP32		10
52 #define TCPOLEN_MPTCP_DSS_MAP64		14
53 #define TCPOLEN_MPTCP_DSS_CHECKSUM	2
54 #define TCPOLEN_MPTCP_ADD_ADDR		16
55 #define TCPOLEN_MPTCP_ADD_ADDR_PORT	20
56 #define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
57 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	12
58 #define TCPOLEN_MPTCP_ADD_ADDR6		28
59 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT	32
60 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
61 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	24
62 #define TCPOLEN_MPTCP_PORT_LEN		4
63 #define TCPOLEN_MPTCP_RM_ADDR_BASE	4
64 #define TCPOLEN_MPTCP_PRIO		3
65 #define TCPOLEN_MPTCP_PRIO_ALIGN	4
66 #define TCPOLEN_MPTCP_FASTCLOSE		12
67 
68 /* MPTCP MP_JOIN flags */
69 #define MPTCPOPT_BACKUP		BIT(0)
70 #define MPTCPOPT_HMAC_LEN	20
71 #define MPTCPOPT_THMAC_LEN	8
72 
73 /* MPTCP MP_CAPABLE flags */
74 #define MPTCP_VERSION_MASK	(0x0F)
75 #define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
76 #define MPTCP_CAP_EXTENSIBILITY	BIT(6)
77 #define MPTCP_CAP_HMAC_SHA256	BIT(0)
78 #define MPTCP_CAP_FLAG_MASK	(0x3F)
79 
80 /* MPTCP DSS flags */
81 #define MPTCP_DSS_DATA_FIN	BIT(4)
82 #define MPTCP_DSS_DSN64		BIT(3)
83 #define MPTCP_DSS_HAS_MAP	BIT(2)
84 #define MPTCP_DSS_ACK64		BIT(1)
85 #define MPTCP_DSS_HAS_ACK	BIT(0)
86 #define MPTCP_DSS_FLAG_MASK	(0x1F)
87 
88 /* MPTCP ADD_ADDR flags */
89 #define MPTCP_ADDR_ECHO		BIT(0)
90 #define MPTCP_ADDR_IPVERSION_4	4
91 #define MPTCP_ADDR_IPVERSION_6	6
92 
93 /* MPTCP MP_PRIO flags */
94 #define MPTCP_PRIO_BKUP		BIT(0)
95 
96 /* MPTCP socket flags */
97 #define MPTCP_DATA_READY	0
98 #define MPTCP_NOSPACE		1
99 #define MPTCP_WORK_RTX		2
100 #define MPTCP_WORK_EOF		3
101 #define MPTCP_FALLBACK_DONE	4
102 #define MPTCP_WORK_CLOSE_SUBFLOW 5
103 #define MPTCP_PUSH_PENDING	6
104 #define MPTCP_CLEAN_UNA		7
105 
106 static inline bool before64(__u64 seq1, __u64 seq2)
107 {
108 	return (__s64)(seq1 - seq2) < 0;
109 }
110 
111 #define after64(seq2, seq1)	before64(seq1, seq2)
112 
113 struct mptcp_options_received {
114 	u64	sndr_key;
115 	u64	rcvr_key;
116 	u64	data_ack;
117 	u64	data_seq;
118 	u32	subflow_seq;
119 	u16	data_len;
120 	u16	mp_capable : 1,
121 		mp_join : 1,
122 		fastclose : 1,
123 		dss : 1,
124 		add_addr : 1,
125 		rm_addr : 1,
126 		mp_prio : 1,
127 		family : 4,
128 		echo : 1,
129 		backup : 1;
130 	u32	token;
131 	u32	nonce;
132 	u64	thmac;
133 	u8	hmac[MPTCPOPT_HMAC_LEN];
134 	u8	join_id;
135 	u8	use_map:1,
136 		dsn64:1,
137 		data_fin:1,
138 		use_ack:1,
139 		ack64:1,
140 		mpc_map:1,
141 		__unused:2;
142 	u8	addr_id;
143 	u8	rm_id;
144 	union {
145 		struct in_addr	addr;
146 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
147 		struct in6_addr	addr6;
148 #endif
149 	};
150 	u64	ahmac;
151 	u16	port;
152 };
153 
154 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
155 {
156 	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
157 		     ((nib & 0xF) << 8) | field);
158 }
159 
160 struct mptcp_addr_info {
161 	sa_family_t		family;
162 	__be16			port;
163 	u8			id;
164 	u8			flags;
165 	int			ifindex;
166 	union {
167 		struct in_addr addr;
168 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
169 		struct in6_addr addr6;
170 #endif
171 	};
172 };
173 
174 enum mptcp_pm_status {
175 	MPTCP_PM_ADD_ADDR_RECEIVED,
176 	MPTCP_PM_ADD_ADDR_SEND_ACK,
177 	MPTCP_PM_RM_ADDR_RECEIVED,
178 	MPTCP_PM_ESTABLISHED,
179 	MPTCP_PM_ALREADY_ESTABLISHED,	/* persistent status, set after ESTABLISHED event */
180 	MPTCP_PM_SUBFLOW_ESTABLISHED,
181 };
182 
183 enum mptcp_addr_signal_status {
184 	MPTCP_ADD_ADDR_SIGNAL,
185 	MPTCP_ADD_ADDR_ECHO,
186 	MPTCP_ADD_ADDR_IPV6,
187 	MPTCP_ADD_ADDR_PORT,
188 	MPTCP_RM_ADDR_SIGNAL,
189 };
190 
191 struct mptcp_pm_data {
192 	struct mptcp_addr_info local;
193 	struct mptcp_addr_info remote;
194 	struct list_head anno_list;
195 
196 	spinlock_t	lock;		/*protects the whole PM data */
197 
198 	u8		addr_signal;
199 	bool		server_side;
200 	bool		work_pending;
201 	bool		accept_addr;
202 	bool		accept_subflow;
203 	u8		add_addr_signaled;
204 	u8		add_addr_accepted;
205 	u8		local_addr_used;
206 	u8		subflows;
207 	u8		status;
208 	u8		rm_id;
209 };
210 
211 struct mptcp_data_frag {
212 	struct list_head list;
213 	u64 data_seq;
214 	u16 data_len;
215 	u16 offset;
216 	u16 overhead;
217 	u16 already_sent;
218 	struct page *page;
219 };
220 
221 /* MPTCP connection sock */
222 struct mptcp_sock {
223 	/* inet_connection_sock must be the first member */
224 	struct inet_connection_sock sk;
225 	u64		local_key;
226 	u64		remote_key;
227 	u64		write_seq;
228 	u64		snd_nxt;
229 	u64		ack_seq;
230 	u64		rcv_wnd_sent;
231 	u64		rcv_data_fin_seq;
232 	int		wmem_reserved;
233 	struct sock	*last_snd;
234 	int		snd_burst;
235 	int		old_wspace;
236 	u64		snd_una;
237 	u64		wnd_end;
238 	unsigned long	timer_ival;
239 	u32		token;
240 	int		rmem_pending;
241 	int		rmem_released;
242 	unsigned long	flags;
243 	bool		can_ack;
244 	bool		fully_established;
245 	bool		rcv_data_fin;
246 	bool		snd_data_fin_enable;
247 	bool		rcv_fastclose;
248 	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */
249 	spinlock_t	join_list_lock;
250 	struct sock	*ack_hint;
251 	struct work_struct work;
252 	struct sk_buff  *ooo_last_skb;
253 	struct rb_root  out_of_order_queue;
254 	struct sk_buff_head receive_queue;
255 	struct sk_buff_head skb_tx_cache;	/* this is wmem accounted */
256 	int		tx_pending_data;
257 	int		size_goal_cache;
258 	struct list_head conn_list;
259 	struct list_head rtx_queue;
260 	struct mptcp_data_frag *first_pending;
261 	struct list_head join_list;
262 	struct socket	*subflow; /* outgoing connect/listener/!mp_capable */
263 	struct sock	*first;
264 	struct mptcp_pm_data	pm;
265 	struct {
266 		u32	space;	/* bytes copied in last measurement window */
267 		u32	copied; /* bytes copied in this measurement window */
268 		u64	time;	/* start time of measurement window */
269 		u64	rtt_us; /* last maximum rtt of subflows */
270 	} rcvq_space;
271 };
272 
273 #define mptcp_lock_sock(___sk, cb) do {					\
274 	struct sock *__sk = (___sk); /* silence macro reuse warning */	\
275 	might_sleep();							\
276 	spin_lock_bh(&__sk->sk_lock.slock);				\
277 	if (__sk->sk_lock.owned)					\
278 		__lock_sock(__sk);					\
279 	cb;								\
280 	__sk->sk_lock.owned = 1;					\
281 	spin_unlock(&__sk->sk_lock.slock);				\
282 	mutex_acquire(&__sk->sk_lock.dep_map, 0, 0, _RET_IP_);		\
283 	local_bh_enable();						\
284 } while (0)
285 
286 #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
287 #define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
288 
289 #define mptcp_for_each_subflow(__msk, __subflow)			\
290 	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
291 
292 static inline void msk_owned_by_me(const struct mptcp_sock *msk)
293 {
294 	sock_owned_by_me((const struct sock *)msk);
295 }
296 
297 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
298 {
299 	return (struct mptcp_sock *)sk;
300 }
301 
302 static inline int __mptcp_space(const struct sock *sk)
303 {
304 	return tcp_space(sk) + READ_ONCE(mptcp_sk(sk)->rmem_pending);
305 }
306 
307 static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
308 {
309 	const struct mptcp_sock *msk = mptcp_sk(sk);
310 
311 	return READ_ONCE(msk->first_pending);
312 }
313 
314 static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
315 {
316 	struct mptcp_sock *msk = mptcp_sk(sk);
317 	struct mptcp_data_frag *cur;
318 
319 	cur = msk->first_pending;
320 	return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
321 						     list_next_entry(cur, list);
322 }
323 
324 static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
325 {
326 	struct mptcp_sock *msk = mptcp_sk(sk);
327 
328 	if (!msk->first_pending)
329 		return NULL;
330 
331 	if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
332 		return NULL;
333 
334 	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
335 }
336 
337 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
338 {
339 	struct mptcp_sock *msk = mptcp_sk(sk);
340 
341 	if (!before64(msk->snd_nxt, READ_ONCE(msk->snd_una)))
342 		return NULL;
343 
344 	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
345 }
346 
347 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
348 {
349 	struct mptcp_sock *msk = mptcp_sk(sk);
350 
351 	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
352 }
353 
354 struct mptcp_subflow_request_sock {
355 	struct	tcp_request_sock sk;
356 	u16	mp_capable : 1,
357 		mp_join : 1,
358 		backup : 1;
359 	u8	local_id;
360 	u8	remote_id;
361 	u64	local_key;
362 	u64	idsn;
363 	u32	token;
364 	u32	ssn_offset;
365 	u64	thmac;
366 	u32	local_nonce;
367 	u32	remote_nonce;
368 	struct mptcp_sock	*msk;
369 	struct hlist_nulls_node token_node;
370 };
371 
372 static inline struct mptcp_subflow_request_sock *
373 mptcp_subflow_rsk(const struct request_sock *rsk)
374 {
375 	return (struct mptcp_subflow_request_sock *)rsk;
376 }
377 
378 enum mptcp_data_avail {
379 	MPTCP_SUBFLOW_NODATA,
380 	MPTCP_SUBFLOW_DATA_AVAIL,
381 	MPTCP_SUBFLOW_OOO_DATA
382 };
383 
384 struct mptcp_delegated_action {
385 	struct napi_struct napi;
386 	struct list_head head;
387 };
388 
389 DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
390 
391 #define MPTCP_DELEGATE_SEND		0
392 
393 /* MPTCP subflow context */
394 struct mptcp_subflow_context {
395 	struct	list_head node;/* conn_list of subflows */
396 	u64	local_key;
397 	u64	remote_key;
398 	u64	idsn;
399 	u64	map_seq;
400 	u32	snd_isn;
401 	u32	token;
402 	u32	rel_write_seq;
403 	u32	map_subflow_seq;
404 	u32	ssn_offset;
405 	u32	map_data_len;
406 	u32	request_mptcp : 1,  /* send MP_CAPABLE */
407 		request_join : 1,   /* send MP_JOIN */
408 		request_bkup : 1,
409 		mp_capable : 1,	    /* remote is MPTCP capable */
410 		mp_join : 1,	    /* remote is JOINing */
411 		fully_established : 1,	    /* path validated */
412 		pm_notified : 1,    /* PM hook called for established status */
413 		conn_finished : 1,
414 		map_valid : 1,
415 		mpc_map : 1,
416 		backup : 1,
417 		send_mp_prio : 1,
418 		rx_eof : 1,
419 		can_ack : 1,        /* only after processing the remote a key */
420 		disposable : 1;	    /* ctx can be free at ulp release time */
421 	enum mptcp_data_avail data_avail;
422 	u32	remote_nonce;
423 	u64	thmac;
424 	u32	local_nonce;
425 	u32	remote_token;
426 	u8	hmac[MPTCPOPT_HMAC_LEN];
427 	u8	local_id;
428 	u8	remote_id;
429 
430 	long	delegated_status;
431 	struct	list_head delegated_node;   /* link into delegated_action, protected by local BH */
432 
433 	struct	sock *tcp_sock;	    /* tcp sk backpointer */
434 	struct	sock *conn;	    /* parent mptcp_sock */
435 	const	struct inet_connection_sock_af_ops *icsk_af_ops;
436 	void	(*tcp_data_ready)(struct sock *sk);
437 	void	(*tcp_state_change)(struct sock *sk);
438 	void	(*tcp_write_space)(struct sock *sk);
439 
440 	struct	rcu_head rcu;
441 };
442 
443 static inline struct mptcp_subflow_context *
444 mptcp_subflow_ctx(const struct sock *sk)
445 {
446 	struct inet_connection_sock *icsk = inet_csk(sk);
447 
448 	/* Use RCU on icsk_ulp_data only for sock diag code */
449 	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
450 }
451 
452 static inline struct sock *
453 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
454 {
455 	return subflow->tcp_sock;
456 }
457 
458 static inline u64
459 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
460 {
461 	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
462 		      subflow->ssn_offset -
463 		      subflow->map_subflow_seq;
464 }
465 
466 static inline u64
467 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
468 {
469 	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
470 }
471 
472 static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
473 					     struct mptcp_subflow_context *subflow)
474 {
475 	sock_hold(mptcp_subflow_tcp_sock(subflow));
476 	spin_lock_bh(&msk->join_list_lock);
477 	list_add_tail(&subflow->node, &msk->join_list);
478 	spin_unlock_bh(&msk->join_list_lock);
479 }
480 
481 void mptcp_subflow_process_delegated(struct sock *ssk);
482 
483 static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow)
484 {
485 	struct mptcp_delegated_action *delegated;
486 	bool schedule;
487 
488 	/* The implied barrier pairs with mptcp_subflow_delegated_done(), and
489 	 * ensures the below list check sees list updates done prior to status
490 	 * bit changes
491 	 */
492 	if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) {
493 		/* still on delegated list from previous scheduling */
494 		if (!list_empty(&subflow->delegated_node))
495 			return;
496 
497 		/* the caller held the subflow bh socket lock */
498 		lockdep_assert_in_softirq();
499 
500 		delegated = this_cpu_ptr(&mptcp_delegated_actions);
501 		schedule = list_empty(&delegated->head);
502 		list_add_tail(&subflow->delegated_node, &delegated->head);
503 		sock_hold(mptcp_subflow_tcp_sock(subflow));
504 		if (schedule)
505 			napi_schedule(&delegated->napi);
506 	}
507 }
508 
509 static inline struct mptcp_subflow_context *
510 mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
511 {
512 	struct mptcp_subflow_context *ret;
513 
514 	if (list_empty(&delegated->head))
515 		return NULL;
516 
517 	ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
518 	list_del_init(&ret->delegated_node);
519 	return ret;
520 }
521 
522 static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
523 {
524 	return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
525 }
526 
527 static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow)
528 {
529 	/* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
530 	 * touching the status bit
531 	 */
532 	smp_wmb();
533 	clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
534 }
535 
536 int mptcp_is_enabled(struct net *net);
537 unsigned int mptcp_get_add_addr_timeout(struct net *net);
538 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
539 				     struct mptcp_options_received *mp_opt);
540 bool mptcp_subflow_data_available(struct sock *sk);
541 void __init mptcp_subflow_init(void);
542 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
543 void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
544 		     struct mptcp_subflow_context *subflow);
545 void mptcp_subflow_reset(struct sock *ssk);
546 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
547 struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
548 
549 /* called with sk socket lock held */
550 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
551 			    const struct mptcp_addr_info *remote);
552 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
553 void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
554 			 struct sockaddr_storage *addr,
555 			 unsigned short family);
556 
557 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
558 					      struct mptcp_subflow_context *ctx)
559 {
560 	sk->sk_data_ready = ctx->tcp_data_ready;
561 	sk->sk_state_change = ctx->tcp_state_change;
562 	sk->sk_write_space = ctx->tcp_write_space;
563 
564 	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
565 }
566 
567 void __init mptcp_proto_init(void);
568 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
569 int __init mptcp_proto_v6_init(void);
570 #endif
571 
572 struct sock *mptcp_sk_clone(const struct sock *sk,
573 			    const struct mptcp_options_received *mp_opt,
574 			    struct request_sock *req);
575 void mptcp_get_options(const struct sk_buff *skb,
576 		       struct mptcp_options_received *mp_opt);
577 
578 void mptcp_finish_connect(struct sock *sk);
579 static inline bool mptcp_is_fully_established(struct sock *sk)
580 {
581 	return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
582 	       READ_ONCE(mptcp_sk(sk)->fully_established);
583 }
584 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
585 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
586 bool mptcp_finish_join(struct sock *sk);
587 bool mptcp_schedule_work(struct sock *sk);
588 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
589 void __mptcp_data_acked(struct sock *sk);
590 void mptcp_subflow_eof(struct sock *sk);
591 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
592 void __mptcp_flush_join_list(struct mptcp_sock *msk);
593 static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
594 {
595 	return READ_ONCE(msk->snd_data_fin_enable) &&
596 	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
597 }
598 
599 static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
600 {
601 	if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
602 		return false;
603 
604 	WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
605 	return true;
606 }
607 
608 static inline void mptcp_write_space(struct sock *sk)
609 {
610 	if (sk_stream_is_writeable(sk)) {
611 		/* pairs with memory barrier in mptcp_poll */
612 		smp_mb();
613 		if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
614 			sk_stream_write_space(sk);
615 	}
616 }
617 
618 void mptcp_destroy_common(struct mptcp_sock *msk);
619 
620 void __init mptcp_token_init(void);
621 static inline void mptcp_token_init_request(struct request_sock *req)
622 {
623 	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
624 }
625 
626 int mptcp_token_new_request(struct request_sock *req);
627 void mptcp_token_destroy_request(struct request_sock *req);
628 int mptcp_token_new_connect(struct sock *sk);
629 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
630 			struct mptcp_sock *msk);
631 bool mptcp_token_exists(u32 token);
632 struct mptcp_sock *mptcp_token_get_sock(u32 token);
633 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
634 					 long *s_num);
635 void mptcp_token_destroy(struct mptcp_sock *msk);
636 
637 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
638 
639 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
640 
641 void __init mptcp_pm_init(void);
642 void mptcp_pm_data_init(struct mptcp_sock *msk);
643 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
644 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
645 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
646 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
647 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
648 				  struct mptcp_subflow_context *subflow);
649 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
650 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
651 				const struct mptcp_addr_info *addr);
652 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
653 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
654 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
655 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
656 				 struct mptcp_addr_info *addr,
657 				 u8 bkup);
658 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
659 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
660 struct mptcp_pm_add_entry *
661 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
662 		       struct mptcp_addr_info *addr);
663 
664 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
665 			   const struct mptcp_addr_info *addr,
666 			   bool echo, bool port);
667 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
668 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id);
669 
670 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
671 		 const struct sock *ssk, gfp_t gfp);
672 void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp_addr_info *info);
673 void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
674 
675 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
676 {
677 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
678 }
679 
680 static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
681 {
682 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
683 }
684 
685 static inline bool mptcp_pm_should_add_signal_ipv6(struct mptcp_sock *msk)
686 {
687 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_IPV6);
688 }
689 
690 static inline bool mptcp_pm_should_add_signal_port(struct mptcp_sock *msk)
691 {
692 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_PORT);
693 }
694 
695 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
696 {
697 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
698 }
699 
700 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
701 {
702 	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
703 
704 	if (family == AF_INET6)
705 		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
706 	if (!echo)
707 		len += MPTCPOPT_THMAC_LEN;
708 	if (port)
709 		len += TCPOLEN_MPTCP_PORT_LEN;
710 
711 	return len;
712 }
713 
714 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
715 			      struct mptcp_addr_info *saddr, bool *echo, bool *port);
716 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
717 			     u8 *rm_id);
718 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
719 
720 void __init mptcp_pm_nl_init(void);
721 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
722 void mptcp_pm_nl_work(struct mptcp_sock *msk);
723 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
724 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
725 unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk);
726 unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk);
727 unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
728 
729 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
730 {
731 	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
732 }
733 
734 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
735 
736 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
737 {
738 	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
739 }
740 
741 static inline bool mptcp_check_fallback(const struct sock *sk)
742 {
743 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
744 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
745 
746 	return __mptcp_check_fallback(msk);
747 }
748 
749 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
750 {
751 	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
752 		pr_debug("TCP fallback already done (msk=%p)", msk);
753 		return;
754 	}
755 	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
756 }
757 
758 static inline void mptcp_do_fallback(struct sock *sk)
759 {
760 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
761 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
762 
763 	__mptcp_do_fallback(msk);
764 }
765 
766 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
767 
768 static inline bool subflow_simultaneous_connect(struct sock *sk)
769 {
770 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
771 	struct sock *parent = subflow->conn;
772 
773 	return sk->sk_state == TCP_ESTABLISHED &&
774 	       !mptcp_sk(parent)->pm.server_side &&
775 	       !subflow->conn_finished;
776 }
777 
778 #ifdef CONFIG_SYN_COOKIES
779 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
780 				       struct sk_buff *skb);
781 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
782 					struct sk_buff *skb);
783 void __init mptcp_join_cookie_init(void);
784 #else
785 static inline void
786 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
787 				  struct sk_buff *skb) {}
788 static inline bool
789 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
790 				   struct sk_buff *skb)
791 {
792 	return false;
793 }
794 
795 static inline void mptcp_join_cookie_init(void) {}
796 #endif
797 
798 #endif /* __MPTCP_PROTOCOL_H */
799