xref: /openbmc/linux/net/mptcp/protocol.h (revision dfe94d40)
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 
14 #define MPTCP_SUPPORTED_VERSION	1
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)
20 #define OPTION_MPTCP_MPJ_SYN	BIT(3)
21 #define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
22 #define OPTION_MPTCP_MPJ_ACK	BIT(5)
23 #define OPTION_MPTCP_ADD_ADDR	BIT(6)
24 #define OPTION_MPTCP_ADD_ADDR6	BIT(7)
25 #define OPTION_MPTCP_RM_ADDR	BIT(8)
26 #define OPTION_MPTCP_FASTCLOSE	BIT(9)
27 
28 /* MPTCP option subtypes */
29 #define MPTCPOPT_MP_CAPABLE	0
30 #define MPTCPOPT_MP_JOIN	1
31 #define MPTCPOPT_DSS		2
32 #define MPTCPOPT_ADD_ADDR	3
33 #define MPTCPOPT_RM_ADDR	4
34 #define MPTCPOPT_MP_PRIO	5
35 #define MPTCPOPT_MP_FAIL	6
36 #define MPTCPOPT_MP_FASTCLOSE	7
37 
38 /* MPTCP suboption lengths */
39 #define TCPOLEN_MPTCP_MPC_SYN		4
40 #define TCPOLEN_MPTCP_MPC_SYNACK	12
41 #define TCPOLEN_MPTCP_MPC_ACK		20
42 #define TCPOLEN_MPTCP_MPC_ACK_DATA	22
43 #define TCPOLEN_MPTCP_MPJ_SYN		12
44 #define TCPOLEN_MPTCP_MPJ_SYNACK	16
45 #define TCPOLEN_MPTCP_MPJ_ACK		24
46 #define TCPOLEN_MPTCP_DSS_BASE		4
47 #define TCPOLEN_MPTCP_DSS_ACK32		4
48 #define TCPOLEN_MPTCP_DSS_ACK64		8
49 #define TCPOLEN_MPTCP_DSS_MAP32		10
50 #define TCPOLEN_MPTCP_DSS_MAP64		14
51 #define TCPOLEN_MPTCP_DSS_CHECKSUM	2
52 #define TCPOLEN_MPTCP_ADD_ADDR		16
53 #define TCPOLEN_MPTCP_ADD_ADDR_PORT	20
54 #define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
55 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	12
56 #define TCPOLEN_MPTCP_ADD_ADDR6		28
57 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT	32
58 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
59 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	24
60 #define TCPOLEN_MPTCP_PORT_LEN		4
61 #define TCPOLEN_MPTCP_RM_ADDR_BASE	4
62 #define TCPOLEN_MPTCP_FASTCLOSE		12
63 
64 /* MPTCP MP_JOIN flags */
65 #define MPTCPOPT_BACKUP		BIT(0)
66 #define MPTCPOPT_HMAC_LEN	20
67 #define MPTCPOPT_THMAC_LEN	8
68 
69 /* MPTCP MP_CAPABLE flags */
70 #define MPTCP_VERSION_MASK	(0x0F)
71 #define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
72 #define MPTCP_CAP_EXTENSIBILITY	BIT(6)
73 #define MPTCP_CAP_HMAC_SHA256	BIT(0)
74 #define MPTCP_CAP_FLAG_MASK	(0x3F)
75 
76 /* MPTCP DSS flags */
77 #define MPTCP_DSS_DATA_FIN	BIT(4)
78 #define MPTCP_DSS_DSN64		BIT(3)
79 #define MPTCP_DSS_HAS_MAP	BIT(2)
80 #define MPTCP_DSS_ACK64		BIT(1)
81 #define MPTCP_DSS_HAS_ACK	BIT(0)
82 #define MPTCP_DSS_FLAG_MASK	(0x1F)
83 
84 /* MPTCP ADD_ADDR flags */
85 #define MPTCP_ADDR_ECHO		BIT(0)
86 #define MPTCP_ADDR_IPVERSION_4	4
87 #define MPTCP_ADDR_IPVERSION_6	6
88 
89 /* MPTCP socket flags */
90 #define MPTCP_DATA_READY	0
91 #define MPTCP_NOSPACE		1
92 #define MPTCP_WORK_RTX		2
93 #define MPTCP_WORK_EOF		3
94 #define MPTCP_FALLBACK_DONE	4
95 #define MPTCP_WORK_CLOSE_SUBFLOW 5
96 #define MPTCP_PUSH_PENDING	6
97 #define MPTCP_CLEAN_UNA		7
98 
99 static inline bool before64(__u64 seq1, __u64 seq2)
100 {
101 	return (__s64)(seq1 - seq2) < 0;
102 }
103 
104 #define after64(seq2, seq1)	before64(seq1, seq2)
105 
106 struct mptcp_options_received {
107 	u64	sndr_key;
108 	u64	rcvr_key;
109 	u64	data_ack;
110 	u64	data_seq;
111 	u32	subflow_seq;
112 	u16	data_len;
113 	u16	mp_capable : 1,
114 		mp_join : 1,
115 		fastclose : 1,
116 		dss : 1,
117 		add_addr : 1,
118 		rm_addr : 1,
119 		family : 4,
120 		echo : 1,
121 		backup : 1;
122 	u32	token;
123 	u32	nonce;
124 	u64	thmac;
125 	u8	hmac[MPTCPOPT_HMAC_LEN];
126 	u8	join_id;
127 	u8	use_map:1,
128 		dsn64:1,
129 		data_fin:1,
130 		use_ack:1,
131 		ack64:1,
132 		mpc_map:1,
133 		__unused:2;
134 	u8	addr_id;
135 	u8	rm_id;
136 	union {
137 		struct in_addr	addr;
138 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
139 		struct in6_addr	addr6;
140 #endif
141 	};
142 	u64	ahmac;
143 	u16	port;
144 };
145 
146 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
147 {
148 	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
149 		     ((nib & 0xF) << 8) | field);
150 }
151 
152 struct mptcp_addr_info {
153 	sa_family_t		family;
154 	__be16			port;
155 	u8			id;
156 	u8			flags;
157 	int			ifindex;
158 	union {
159 		struct in_addr addr;
160 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
161 		struct in6_addr addr6;
162 #endif
163 	};
164 };
165 
166 enum mptcp_pm_status {
167 	MPTCP_PM_ADD_ADDR_RECEIVED,
168 	MPTCP_PM_ADD_ADDR_SEND_ACK,
169 	MPTCP_PM_RM_ADDR_RECEIVED,
170 	MPTCP_PM_ESTABLISHED,
171 	MPTCP_PM_ALREADY_ESTABLISHED,	/* persistent status, set after ESTABLISHED event */
172 	MPTCP_PM_SUBFLOW_ESTABLISHED,
173 };
174 
175 enum mptcp_addr_signal_status {
176 	MPTCP_ADD_ADDR_SIGNAL,
177 	MPTCP_ADD_ADDR_ECHO,
178 	MPTCP_ADD_ADDR_IPV6,
179 	MPTCP_ADD_ADDR_PORT,
180 	MPTCP_RM_ADDR_SIGNAL,
181 };
182 
183 struct mptcp_pm_data {
184 	struct mptcp_addr_info local;
185 	struct mptcp_addr_info remote;
186 	struct list_head anno_list;
187 
188 	spinlock_t	lock;		/*protects the whole PM data */
189 
190 	u8		addr_signal;
191 	bool		server_side;
192 	bool		work_pending;
193 	bool		accept_addr;
194 	bool		accept_subflow;
195 	u8		add_addr_signaled;
196 	u8		add_addr_accepted;
197 	u8		local_addr_used;
198 	u8		subflows;
199 	u8		add_addr_signal_max;
200 	u8		add_addr_accept_max;
201 	u8		local_addr_max;
202 	u8		subflows_max;
203 	u8		status;
204 	u8		rm_id;
205 };
206 
207 struct mptcp_data_frag {
208 	struct list_head list;
209 	u64 data_seq;
210 	u16 data_len;
211 	u16 offset;
212 	u16 overhead;
213 	u16 already_sent;
214 	struct page *page;
215 };
216 
217 /* MPTCP connection sock */
218 struct mptcp_sock {
219 	/* inet_connection_sock must be the first member */
220 	struct inet_connection_sock sk;
221 	u64		local_key;
222 	u64		remote_key;
223 	u64		write_seq;
224 	u64		snd_nxt;
225 	u64		ack_seq;
226 	u64		rcv_wnd_sent;
227 	u64		rcv_data_fin_seq;
228 	int		wmem_reserved;
229 	struct sock	*last_snd;
230 	int		snd_burst;
231 	int		old_wspace;
232 	u64		snd_una;
233 	u64		wnd_end;
234 	unsigned long	timer_ival;
235 	u32		token;
236 	int		rmem_pending;
237 	int		rmem_released;
238 	unsigned long	flags;
239 	bool		can_ack;
240 	bool		fully_established;
241 	bool		rcv_data_fin;
242 	bool		snd_data_fin_enable;
243 	bool		rcv_fastclose;
244 	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */
245 	spinlock_t	join_list_lock;
246 	struct sock	*ack_hint;
247 	struct work_struct work;
248 	struct sk_buff  *ooo_last_skb;
249 	struct rb_root  out_of_order_queue;
250 	struct sk_buff_head receive_queue;
251 	struct sk_buff_head skb_tx_cache;	/* this is wmem accounted */
252 	int		tx_pending_data;
253 	int		size_goal_cache;
254 	struct list_head conn_list;
255 	struct list_head rtx_queue;
256 	struct mptcp_data_frag *first_pending;
257 	struct list_head join_list;
258 	struct socket	*subflow; /* outgoing connect/listener/!mp_capable */
259 	struct sock	*first;
260 	struct mptcp_pm_data	pm;
261 	struct {
262 		u32	space;	/* bytes copied in last measurement window */
263 		u32	copied; /* bytes copied in this measurement window */
264 		u64	time;	/* start time of measurement window */
265 		u64	rtt_us; /* last maximum rtt of subflows */
266 	} rcvq_space;
267 };
268 
269 #define mptcp_lock_sock(___sk, cb) do {					\
270 	struct sock *__sk = (___sk); /* silence macro reuse warning */	\
271 	might_sleep();							\
272 	spin_lock_bh(&__sk->sk_lock.slock);				\
273 	if (__sk->sk_lock.owned)					\
274 		__lock_sock(__sk);					\
275 	cb;								\
276 	__sk->sk_lock.owned = 1;					\
277 	spin_unlock(&__sk->sk_lock.slock);				\
278 	mutex_acquire(&__sk->sk_lock.dep_map, 0, 0, _RET_IP_);		\
279 	local_bh_enable();						\
280 } while (0)
281 
282 #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
283 #define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
284 
285 #define mptcp_for_each_subflow(__msk, __subflow)			\
286 	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
287 
288 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
289 {
290 	return (struct mptcp_sock *)sk;
291 }
292 
293 static inline int __mptcp_space(const struct sock *sk)
294 {
295 	return tcp_space(sk) + READ_ONCE(mptcp_sk(sk)->rmem_pending);
296 }
297 
298 static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
299 {
300 	const struct mptcp_sock *msk = mptcp_sk(sk);
301 
302 	return READ_ONCE(msk->first_pending);
303 }
304 
305 static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
306 {
307 	struct mptcp_sock *msk = mptcp_sk(sk);
308 	struct mptcp_data_frag *cur;
309 
310 	cur = msk->first_pending;
311 	return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
312 						     list_next_entry(cur, list);
313 }
314 
315 static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
316 {
317 	struct mptcp_sock *msk = mptcp_sk(sk);
318 
319 	if (!msk->first_pending)
320 		return NULL;
321 
322 	if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
323 		return NULL;
324 
325 	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
326 }
327 
328 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
329 {
330 	struct mptcp_sock *msk = mptcp_sk(sk);
331 
332 	if (!before64(msk->snd_nxt, READ_ONCE(msk->snd_una)))
333 		return NULL;
334 
335 	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
336 }
337 
338 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
339 {
340 	struct mptcp_sock *msk = mptcp_sk(sk);
341 
342 	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
343 }
344 
345 struct mptcp_subflow_request_sock {
346 	struct	tcp_request_sock sk;
347 	u16	mp_capable : 1,
348 		mp_join : 1,
349 		backup : 1;
350 	u8	local_id;
351 	u8	remote_id;
352 	u64	local_key;
353 	u64	idsn;
354 	u32	token;
355 	u32	ssn_offset;
356 	u64	thmac;
357 	u32	local_nonce;
358 	u32	remote_nonce;
359 	struct mptcp_sock	*msk;
360 	struct hlist_nulls_node token_node;
361 };
362 
363 static inline struct mptcp_subflow_request_sock *
364 mptcp_subflow_rsk(const struct request_sock *rsk)
365 {
366 	return (struct mptcp_subflow_request_sock *)rsk;
367 }
368 
369 enum mptcp_data_avail {
370 	MPTCP_SUBFLOW_NODATA,
371 	MPTCP_SUBFLOW_DATA_AVAIL,
372 	MPTCP_SUBFLOW_OOO_DATA
373 };
374 
375 /* MPTCP subflow context */
376 struct mptcp_subflow_context {
377 	struct	list_head node;/* conn_list of subflows */
378 	u64	local_key;
379 	u64	remote_key;
380 	u64	idsn;
381 	u64	map_seq;
382 	u32	snd_isn;
383 	u32	token;
384 	u32	rel_write_seq;
385 	u32	map_subflow_seq;
386 	u32	ssn_offset;
387 	u32	map_data_len;
388 	u32	request_mptcp : 1,  /* send MP_CAPABLE */
389 		request_join : 1,   /* send MP_JOIN */
390 		request_bkup : 1,
391 		mp_capable : 1,	    /* remote is MPTCP capable */
392 		mp_join : 1,	    /* remote is JOINing */
393 		fully_established : 1,	    /* path validated */
394 		pm_notified : 1,    /* PM hook called for established status */
395 		conn_finished : 1,
396 		map_valid : 1,
397 		mpc_map : 1,
398 		backup : 1,
399 		rx_eof : 1,
400 		can_ack : 1,        /* only after processing the remote a key */
401 		disposable : 1;	    /* ctx can be free at ulp release time */
402 	enum mptcp_data_avail data_avail;
403 	u32	remote_nonce;
404 	u64	thmac;
405 	u32	local_nonce;
406 	u32	remote_token;
407 	u8	hmac[MPTCPOPT_HMAC_LEN];
408 	u8	local_id;
409 	u8	remote_id;
410 
411 	struct	sock *tcp_sock;	    /* tcp sk backpointer */
412 	struct	sock *conn;	    /* parent mptcp_sock */
413 	const	struct inet_connection_sock_af_ops *icsk_af_ops;
414 	void	(*tcp_data_ready)(struct sock *sk);
415 	void	(*tcp_state_change)(struct sock *sk);
416 	void	(*tcp_write_space)(struct sock *sk);
417 
418 	struct	rcu_head rcu;
419 };
420 
421 static inline struct mptcp_subflow_context *
422 mptcp_subflow_ctx(const struct sock *sk)
423 {
424 	struct inet_connection_sock *icsk = inet_csk(sk);
425 
426 	/* Use RCU on icsk_ulp_data only for sock diag code */
427 	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
428 }
429 
430 static inline struct sock *
431 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
432 {
433 	return subflow->tcp_sock;
434 }
435 
436 static inline u64
437 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
438 {
439 	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
440 		      subflow->ssn_offset -
441 		      subflow->map_subflow_seq;
442 }
443 
444 static inline u64
445 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
446 {
447 	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
448 }
449 
450 static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
451 					     struct mptcp_subflow_context *subflow)
452 {
453 	sock_hold(mptcp_subflow_tcp_sock(subflow));
454 	spin_lock_bh(&msk->join_list_lock);
455 	list_add_tail(&subflow->node, &msk->join_list);
456 	spin_unlock_bh(&msk->join_list_lock);
457 }
458 
459 int mptcp_is_enabled(struct net *net);
460 unsigned int mptcp_get_add_addr_timeout(struct net *net);
461 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
462 				     struct mptcp_options_received *mp_opt);
463 bool mptcp_subflow_data_available(struct sock *sk);
464 void __init mptcp_subflow_init(void);
465 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
466 void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
467 		       struct mptcp_subflow_context *subflow);
468 void mptcp_subflow_reset(struct sock *ssk);
469 
470 /* called with sk socket lock held */
471 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
472 			    const struct mptcp_addr_info *remote);
473 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
474 
475 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
476 					      struct mptcp_subflow_context *ctx)
477 {
478 	sk->sk_data_ready = ctx->tcp_data_ready;
479 	sk->sk_state_change = ctx->tcp_state_change;
480 	sk->sk_write_space = ctx->tcp_write_space;
481 
482 	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
483 }
484 
485 void __init mptcp_proto_init(void);
486 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
487 int __init mptcp_proto_v6_init(void);
488 #endif
489 
490 struct sock *mptcp_sk_clone(const struct sock *sk,
491 			    const struct mptcp_options_received *mp_opt,
492 			    struct request_sock *req);
493 void mptcp_get_options(const struct sk_buff *skb,
494 		       struct mptcp_options_received *mp_opt);
495 
496 void mptcp_finish_connect(struct sock *sk);
497 static inline bool mptcp_is_fully_established(struct sock *sk)
498 {
499 	return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
500 	       READ_ONCE(mptcp_sk(sk)->fully_established);
501 }
502 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
503 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
504 bool mptcp_finish_join(struct sock *sk);
505 bool mptcp_schedule_work(struct sock *sk);
506 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
507 void __mptcp_data_acked(struct sock *sk);
508 void mptcp_subflow_eof(struct sock *sk);
509 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
510 void __mptcp_flush_join_list(struct mptcp_sock *msk);
511 static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
512 {
513 	return READ_ONCE(msk->snd_data_fin_enable) &&
514 	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
515 }
516 
517 void mptcp_destroy_common(struct mptcp_sock *msk);
518 
519 void __init mptcp_token_init(void);
520 static inline void mptcp_token_init_request(struct request_sock *req)
521 {
522 	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
523 }
524 
525 int mptcp_token_new_request(struct request_sock *req);
526 void mptcp_token_destroy_request(struct request_sock *req);
527 int mptcp_token_new_connect(struct sock *sk);
528 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
529 			struct mptcp_sock *msk);
530 bool mptcp_token_exists(u32 token);
531 struct mptcp_sock *mptcp_token_get_sock(u32 token);
532 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
533 					 long *s_num);
534 void mptcp_token_destroy(struct mptcp_sock *msk);
535 
536 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
537 
538 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
539 
540 void __init mptcp_pm_init(void);
541 void mptcp_pm_data_init(struct mptcp_sock *msk);
542 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
543 void mptcp_pm_fully_established(struct mptcp_sock *msk);
544 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
545 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
546 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
547 				  struct mptcp_subflow_context *subflow);
548 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
549 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
550 				const struct mptcp_addr_info *addr);
551 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
552 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
553 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
554 struct mptcp_pm_add_entry *
555 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
556 		       struct mptcp_addr_info *addr);
557 
558 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
559 			   const struct mptcp_addr_info *addr,
560 			   bool echo, bool port);
561 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
562 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id);
563 
564 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
565 {
566 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
567 }
568 
569 static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
570 {
571 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
572 }
573 
574 static inline bool mptcp_pm_should_add_signal_ipv6(struct mptcp_sock *msk)
575 {
576 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_IPV6);
577 }
578 
579 static inline bool mptcp_pm_should_add_signal_port(struct mptcp_sock *msk)
580 {
581 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_PORT);
582 }
583 
584 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
585 {
586 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
587 }
588 
589 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
590 {
591 	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
592 
593 	if (family == AF_INET6)
594 		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
595 	if (!echo)
596 		len += MPTCPOPT_THMAC_LEN;
597 	if (port)
598 		len += TCPOLEN_MPTCP_PORT_LEN;
599 
600 	return len;
601 }
602 
603 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
604 			      struct mptcp_addr_info *saddr, bool *echo, bool *port);
605 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
606 			     u8 *rm_id);
607 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
608 
609 void __init mptcp_pm_nl_init(void);
610 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
611 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
612 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
613 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
614 void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk);
615 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
616 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
617 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
618 
619 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
620 {
621 	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
622 }
623 
624 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
625 
626 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
627 {
628 	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
629 }
630 
631 static inline bool mptcp_check_fallback(const struct sock *sk)
632 {
633 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
634 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
635 
636 	return __mptcp_check_fallback(msk);
637 }
638 
639 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
640 {
641 	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
642 		pr_debug("TCP fallback already done (msk=%p)", msk);
643 		return;
644 	}
645 	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
646 }
647 
648 static inline void mptcp_do_fallback(struct sock *sk)
649 {
650 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
651 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
652 
653 	__mptcp_do_fallback(msk);
654 }
655 
656 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
657 
658 static inline bool subflow_simultaneous_connect(struct sock *sk)
659 {
660 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
661 	struct sock *parent = subflow->conn;
662 
663 	return sk->sk_state == TCP_ESTABLISHED &&
664 	       !mptcp_sk(parent)->pm.server_side &&
665 	       !subflow->conn_finished;
666 }
667 
668 #ifdef CONFIG_SYN_COOKIES
669 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
670 				       struct sk_buff *skb);
671 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
672 					struct sk_buff *skb);
673 void __init mptcp_join_cookie_init(void);
674 #else
675 static inline void
676 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
677 				  struct sk_buff *skb) {}
678 static inline bool
679 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
680 				   struct sk_buff *skb)
681 {
682 	return false;
683 }
684 
685 static inline void mptcp_join_cookie_init(void) {}
686 #endif
687 
688 #endif /* __MPTCP_PROTOCOL_H */
689