xref: /linux/net/mptcp/protocol.h (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
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 #include <net/genetlink.h>
15 #include <net/rstreason.h>
16 
17 #define MPTCP_SUPPORTED_VERSION	1
18 
19 /* MPTCP option bits */
20 #define OPTION_MPTCP_MPC_SYN	BIT(0)
21 #define OPTION_MPTCP_MPC_SYNACK	BIT(1)
22 #define OPTION_MPTCP_MPC_ACK	BIT(2)
23 #define OPTION_MPTCP_MPJ_SYN	BIT(3)
24 #define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
25 #define OPTION_MPTCP_MPJ_ACK	BIT(5)
26 #define OPTION_MPTCP_ADD_ADDR	BIT(6)
27 #define OPTION_MPTCP_RM_ADDR	BIT(7)
28 #define OPTION_MPTCP_FASTCLOSE	BIT(8)
29 #define OPTION_MPTCP_PRIO	BIT(9)
30 #define OPTION_MPTCP_RST	BIT(10)
31 #define OPTION_MPTCP_DSS	BIT(11)
32 #define OPTION_MPTCP_FAIL	BIT(12)
33 
34 #define OPTION_MPTCP_CSUMREQD	BIT(13)
35 
36 #define OPTIONS_MPTCP_MPC	(OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
37 				 OPTION_MPTCP_MPC_ACK)
38 #define OPTIONS_MPTCP_MPJ	(OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
39 				 OPTION_MPTCP_MPJ_ACK)
40 
41 /* MPTCP option subtypes */
42 #define MPTCPOPT_MP_CAPABLE	0
43 #define MPTCPOPT_MP_JOIN	1
44 #define MPTCPOPT_DSS		2
45 #define MPTCPOPT_ADD_ADDR	3
46 #define MPTCPOPT_RM_ADDR	4
47 #define MPTCPOPT_MP_PRIO	5
48 #define MPTCPOPT_MP_FAIL	6
49 #define MPTCPOPT_MP_FASTCLOSE	7
50 #define MPTCPOPT_RST		8
51 
52 /* MPTCP suboption lengths */
53 #define TCPOLEN_MPTCP_MPC_SYN		4
54 #define TCPOLEN_MPTCP_MPC_SYNACK	12
55 #define TCPOLEN_MPTCP_MPC_ACK		20
56 #define TCPOLEN_MPTCP_MPC_ACK_DATA	22
57 #define TCPOLEN_MPTCP_MPJ_SYN		12
58 #define TCPOLEN_MPTCP_MPJ_SYNACK	16
59 #define TCPOLEN_MPTCP_MPJ_ACK		24
60 #define TCPOLEN_MPTCP_DSS_BASE		4
61 #define TCPOLEN_MPTCP_DSS_ACK32		4
62 #define TCPOLEN_MPTCP_DSS_ACK64		8
63 #define TCPOLEN_MPTCP_DSS_MAP32		10
64 #define TCPOLEN_MPTCP_DSS_MAP64		14
65 #define TCPOLEN_MPTCP_DSS_CHECKSUM	2
66 #define TCPOLEN_MPTCP_ADD_ADDR		16
67 #define TCPOLEN_MPTCP_ADD_ADDR_PORT	18
68 #define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
69 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	10
70 #define TCPOLEN_MPTCP_ADD_ADDR6		28
71 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT	30
72 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
73 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	22
74 #define TCPOLEN_MPTCP_PORT_LEN		2
75 #define TCPOLEN_MPTCP_PORT_ALIGN	2
76 #define TCPOLEN_MPTCP_RM_ADDR_BASE	3
77 #define TCPOLEN_MPTCP_PRIO		3
78 #define TCPOLEN_MPTCP_PRIO_ALIGN	4
79 #define TCPOLEN_MPTCP_FASTCLOSE		12
80 #define TCPOLEN_MPTCP_RST		4
81 #define TCPOLEN_MPTCP_FAIL		12
82 
83 #define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM	(TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
84 
85 /* MPTCP MP_JOIN flags */
86 #define MPTCPOPT_BACKUP		BIT(0)
87 #define MPTCPOPT_THMAC_LEN	8
88 
89 /* MPTCP MP_CAPABLE flags */
90 #define MPTCP_VERSION_MASK	(0x0F)
91 #define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
92 #define MPTCP_CAP_EXTENSIBILITY	BIT(6)
93 #define MPTCP_CAP_DENY_JOIN_ID0	BIT(5)
94 #define MPTCP_CAP_HMAC_SHA256	BIT(0)
95 #define MPTCP_CAP_FLAG_MASK	(0x1F)
96 
97 /* MPTCP DSS flags */
98 #define MPTCP_DSS_DATA_FIN	BIT(4)
99 #define MPTCP_DSS_DSN64		BIT(3)
100 #define MPTCP_DSS_HAS_MAP	BIT(2)
101 #define MPTCP_DSS_ACK64		BIT(1)
102 #define MPTCP_DSS_HAS_ACK	BIT(0)
103 #define MPTCP_DSS_FLAG_MASK	(0x1F)
104 
105 /* MPTCP ADD_ADDR flags */
106 #define MPTCP_ADDR_ECHO		BIT(0)
107 
108 /* MPTCP MP_PRIO flags */
109 #define MPTCP_PRIO_BKUP		BIT(0)
110 
111 /* MPTCP TCPRST flags */
112 #define MPTCP_RST_TRANSIENT	BIT(0)
113 
114 /* MPTCP socket atomic flags */
115 #define MPTCP_WORK_RTX		1
116 #define MPTCP_FALLBACK_DONE	2
117 #define MPTCP_WORK_CLOSE_SUBFLOW 3
118 
119 /* MPTCP socket release cb flags */
120 #define MPTCP_PUSH_PENDING	1
121 #define MPTCP_CLEAN_UNA		2
122 #define MPTCP_ERROR_REPORT	3
123 #define MPTCP_RETRANSMIT	4
124 #define MPTCP_FLUSH_JOIN_LIST	5
125 #define MPTCP_SYNC_STATE	6
126 #define MPTCP_SYNC_SNDBUF	7
127 #define MPTCP_DEQUEUE		8
128 
129 struct mptcp_skb_cb {
130 	u64 map_seq;
131 	u64 end_seq;
132 	u32 offset;
133 	u8  has_rxtstamp;
134 	u8  cant_coalesce;
135 };
136 
137 #define MPTCP_SKB_CB(__skb)	((struct mptcp_skb_cb *)&((__skb)->cb[0]))
138 
before64(__u64 seq1,__u64 seq2)139 static inline bool before64(__u64 seq1, __u64 seq2)
140 {
141 	return (__s64)(seq1 - seq2) < 0;
142 }
143 
144 #define after64(seq2, seq1)	before64(seq1, seq2)
145 
146 struct mptcp_options_received {
147 	u64	sndr_key;
148 	u64	rcvr_key;
149 	u64	data_ack;
150 	u64	data_seq;
151 	u32	subflow_seq;
152 	u16	data_len;
153 	__sum16	csum;
154 	struct_group(status,
155 		u16 suboptions;
156 		u16 use_map:1,
157 		    dsn64:1,
158 		    data_fin:1,
159 		    use_ack:1,
160 		    ack64:1,
161 		    mpc_map:1,
162 		    reset_reason:4,
163 		    reset_transient:1,
164 		    echo:1,
165 		    backup:1,
166 		    deny_join_id0:1,
167 		    __unused:2;
168 	);
169 	u8	join_id;
170 	u32	token;
171 	u32	nonce;
172 	u64	thmac;
173 	u8	hmac[MPTCPOPT_HMAC_LEN];
174 	struct mptcp_addr_info addr;
175 	struct mptcp_rm_list rm_list;
176 	u64	ahmac;
177 	u64	fail_seq;
178 };
179 
mptcp_option(u8 subopt,u8 len,u8 nib,u8 field)180 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
181 {
182 	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
183 		     ((nib & 0xF) << 8) | field);
184 }
185 
186 enum mptcp_pm_status {
187 	MPTCP_PM_ADD_ADDR_RECEIVED,
188 	MPTCP_PM_ADD_ADDR_SEND_ACK,
189 	MPTCP_PM_RM_ADDR_RECEIVED,
190 	MPTCP_PM_ESTABLISHED,
191 	MPTCP_PM_SUBFLOW_ESTABLISHED,
192 	MPTCP_PM_ALREADY_ESTABLISHED,	/* persistent status, set after ESTABLISHED event */
193 	MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
194 					 * accounted int id_avail_bitmap
195 					 */
196 };
197 
198 enum mptcp_pm_type {
199 	MPTCP_PM_TYPE_KERNEL = 0,
200 	MPTCP_PM_TYPE_USERSPACE,
201 
202 	__MPTCP_PM_TYPE_NR,
203 	__MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
204 };
205 
206 /* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
207 #define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
208 
209 enum mptcp_addr_signal_status {
210 	MPTCP_ADD_ADDR_SIGNAL,
211 	MPTCP_ADD_ADDR_ECHO,
212 	MPTCP_RM_ADDR_SIGNAL,
213 };
214 
215 /* max value of mptcp_addr_info.id */
216 #define MPTCP_PM_MAX_ADDR_ID		U8_MAX
217 
218 struct mptcp_pm_data {
219 	struct mptcp_addr_info local;
220 	struct mptcp_addr_info remote;
221 	struct list_head anno_list;
222 	struct list_head userspace_pm_local_addr_list;
223 
224 	spinlock_t	lock;		/*protects the whole PM data */
225 
226 	struct_group(reset,
227 
228 	u8		addr_signal;
229 	bool		server_side;
230 	bool		work_pending;
231 	bool		accept_addr;
232 	bool		accept_subflow;
233 	bool		remote_deny_join_id0;
234 	u8		add_addr_signaled;
235 	u8		add_addr_accepted;
236 	u8		local_addr_used;
237 	u8		pm_type;
238 	u8		subflows;
239 	u8		status;
240 
241 	);
242 
243 	DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
244 	struct mptcp_rm_list rm_list_tx;
245 	struct mptcp_rm_list rm_list_rx;
246 };
247 
248 struct mptcp_pm_local {
249 	struct mptcp_addr_info	addr;
250 	u8			flags;
251 	int			ifindex;
252 };
253 
254 struct mptcp_pm_addr_entry {
255 	struct list_head	list;
256 	struct mptcp_addr_info	addr;
257 	u8			flags;
258 	int			ifindex;
259 	struct socket		*lsk;
260 };
261 
262 struct mptcp_data_frag {
263 	struct list_head list;
264 	u64 data_seq;
265 	u16 data_len;
266 	u16 offset;
267 	u16 overhead;
268 	u16 already_sent;
269 	struct page *page;
270 };
271 
272 /* MPTCP connection sock */
273 struct mptcp_sock {
274 	/* inet_connection_sock must be the first member */
275 	struct inet_connection_sock sk;
276 	u64		local_key;		/* protected by the first subflow socket lock
277 						 * lockless access read
278 						 */
279 	u64		remote_key;		/* same as above */
280 	u64		write_seq;
281 	u64		bytes_sent;
282 	u64		snd_nxt;
283 	u64		bytes_received;
284 	u64		ack_seq;
285 	atomic64_t	rcv_wnd_sent;
286 	u64		rcv_data_fin_seq;
287 	u64		bytes_retrans;
288 	u64		bytes_consumed;
289 	int		snd_burst;
290 	int		old_wspace;
291 	u64		recovery_snd_nxt;	/* in recovery mode accept up to this seq;
292 						 * recovery related fields are under data_lock
293 						 * protection
294 						 */
295 	u64		bytes_acked;
296 	u64		snd_una;
297 	u64		wnd_end;
298 	u32		last_data_sent;
299 	u32		last_data_recv;
300 	u32		last_ack_recv;
301 	unsigned long	timer_ival;
302 	u32		token;
303 	unsigned long	flags;
304 	unsigned long	cb_flags;
305 	bool		recovery;		/* closing subflow write queue reinjected */
306 	bool		can_ack;
307 	bool		fully_established;
308 	bool		rcv_data_fin;
309 	bool		snd_data_fin_enable;
310 	bool		rcv_fastclose;
311 	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */
312 	bool		csum_enabled;
313 	bool		allow_infinite_fallback;
314 	u8		pending_state; /* A subflow asked to set this sk_state,
315 					* protected by the msk data lock
316 					*/
317 	u8		mpc_endpoint_id;
318 	u8		recvmsg_inq:1,
319 			cork:1,
320 			nodelay:1,
321 			fastopening:1,
322 			in_accept_queue:1,
323 			free_first:1,
324 			rcvspace_init:1;
325 	u32		notsent_lowat;
326 	int		keepalive_cnt;
327 	int		keepalive_idle;
328 	int		keepalive_intvl;
329 	int		maxseg;
330 	struct work_struct work;
331 	struct sk_buff  *ooo_last_skb;
332 	struct rb_root  out_of_order_queue;
333 	struct list_head conn_list;
334 	struct list_head rtx_queue;
335 	struct mptcp_data_frag *first_pending;
336 	struct list_head join_list;
337 	struct sock	*first; /* The mptcp ops can safely dereference, using suitable
338 				 * ONCE annotation, the subflow outside the socket
339 				 * lock as such sock is freed after close().
340 				 */
341 	struct mptcp_pm_data	pm;
342 	struct mptcp_sched_ops	*sched;
343 	struct {
344 		u32	space;	/* bytes copied in last measurement window */
345 		u32	copied; /* bytes copied in this measurement window */
346 		u64	time;	/* start time of measurement window */
347 		u64	rtt_us; /* last maximum rtt of subflows */
348 	} rcvq_space;
349 	u8		scaling_ratio;
350 	bool		allow_subflows;
351 
352 	u32		subflow_id;
353 	u32		setsockopt_seq;
354 	char		ca_name[TCP_CA_NAME_MAX];
355 
356 	spinlock_t	fallback_lock;	/* protects fallback,
357 					 * allow_infinite_fallback and
358 					 * allow_join
359 					 */
360 };
361 
362 #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
363 #define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
364 
365 #define mptcp_for_each_subflow(__msk, __subflow)			\
366 	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
367 #define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp)			\
368 	list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
369 #define mptcp_next_subflow(__msk, __subflow)				\
370 	list_next_entry_circular(__subflow, &((__msk)->conn_list), node)
371 
372 extern struct genl_family mptcp_genl_family;
373 
msk_owned_by_me(const struct mptcp_sock * msk)374 static inline void msk_owned_by_me(const struct mptcp_sock *msk)
375 {
376 	sock_owned_by_me((const struct sock *)msk);
377 }
378 
379 #ifdef CONFIG_DEBUG_NET
380 /* MPTCP-specific: we might (indirectly) call this helper with the wrong sk */
381 #undef tcp_sk
382 #define tcp_sk(ptr) ({								\
383 	typeof(ptr) _ptr = (ptr);						\
384 	WARN_ON(_ptr->sk_protocol != IPPROTO_TCP);				\
385 	container_of_const(_ptr, struct tcp_sock, inet_conn.icsk_inet.sk);	\
386 })
387 #define mptcp_sk(ptr) ({						\
388 	typeof(ptr) _ptr = (ptr);					\
389 	WARN_ON(_ptr->sk_protocol != IPPROTO_MPTCP);			\
390 	container_of_const(_ptr, struct mptcp_sock, sk.icsk_inet.sk);	\
391 })
392 
393 #else /* !CONFIG_DEBUG_NET */
394 #define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk)
395 #endif
396 
mptcp_win_from_space(const struct sock * sk,int space)397 static inline int mptcp_win_from_space(const struct sock *sk, int space)
398 {
399 	return __tcp_win_from_space(mptcp_sk(sk)->scaling_ratio, space);
400 }
401 
mptcp_space_from_win(const struct sock * sk,int win)402 static inline int mptcp_space_from_win(const struct sock *sk, int win)
403 {
404 	return __tcp_space_from_win(mptcp_sk(sk)->scaling_ratio, win);
405 }
406 
__mptcp_space(const struct sock * sk)407 static inline int __mptcp_space(const struct sock *sk)
408 {
409 	return mptcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) -
410 				    sk_rmem_alloc_get(sk));
411 }
412 
mptcp_send_head(const struct sock * sk)413 static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
414 {
415 	const struct mptcp_sock *msk = mptcp_sk(sk);
416 
417 	return READ_ONCE(msk->first_pending);
418 }
419 
mptcp_send_next(struct sock * sk)420 static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
421 {
422 	struct mptcp_sock *msk = mptcp_sk(sk);
423 	struct mptcp_data_frag *cur;
424 
425 	cur = msk->first_pending;
426 	return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
427 						     list_next_entry(cur, list);
428 }
429 
mptcp_pending_tail(const struct sock * sk)430 static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
431 {
432 	const struct mptcp_sock *msk = mptcp_sk(sk);
433 
434 	if (!msk->first_pending)
435 		return NULL;
436 
437 	if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
438 		return NULL;
439 
440 	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
441 }
442 
mptcp_rtx_head(struct sock * sk)443 static inline struct mptcp_data_frag *mptcp_rtx_head(struct sock *sk)
444 {
445 	struct mptcp_sock *msk = mptcp_sk(sk);
446 
447 	if (msk->snd_una == msk->snd_nxt)
448 		return NULL;
449 
450 	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
451 }
452 
453 struct csum_pseudo_header {
454 	__be64 data_seq;
455 	__be32 subflow_seq;
456 	__be16 data_len;
457 	__sum16 csum;
458 };
459 
460 struct mptcp_subflow_request_sock {
461 	struct	tcp_request_sock sk;
462 	u16	mp_capable : 1,
463 		mp_join : 1,
464 		backup : 1,
465 		request_bkup : 1,
466 		csum_reqd : 1,
467 		allow_join_id0 : 1;
468 	u8	local_id;
469 	u8	remote_id;
470 	u64	local_key;
471 	u64	idsn;
472 	u32	token;
473 	u32	ssn_offset;
474 	u64	thmac;
475 	u32	local_nonce;
476 	u32	remote_nonce;
477 	struct mptcp_sock	*msk;
478 	struct hlist_nulls_node token_node;
479 };
480 
481 static inline struct mptcp_subflow_request_sock *
mptcp_subflow_rsk(const struct request_sock * rsk)482 mptcp_subflow_rsk(const struct request_sock *rsk)
483 {
484 	return (struct mptcp_subflow_request_sock *)rsk;
485 }
486 
487 struct mptcp_delegated_action {
488 	struct napi_struct napi;
489 	local_lock_t bh_lock;
490 	struct list_head head;
491 };
492 
493 DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
494 
495 #define MPTCP_DELEGATE_SCHEDULED	0
496 #define MPTCP_DELEGATE_SEND		1
497 #define MPTCP_DELEGATE_ACK		2
498 #define MPTCP_DELEGATE_SNDBUF		3
499 
500 #define MPTCP_DELEGATE_ACTIONS_MASK	(~BIT(MPTCP_DELEGATE_SCHEDULED))
501 /* MPTCP subflow context */
502 struct mptcp_subflow_context {
503 	struct	list_head node;/* conn_list of subflows */
504 
505 	struct_group(reset,
506 
507 	unsigned long avg_pacing_rate; /* protected by msk socket lock */
508 	u64	local_key;
509 	u64	remote_key;
510 	u64	idsn;
511 	u64	map_seq;
512 	u32	snd_isn;
513 	u32	token;
514 	u32	rel_write_seq;
515 	u32	map_subflow_seq;
516 	u32	ssn_offset;
517 	u32	map_data_len;
518 	__wsum	map_data_csum;
519 	u32	map_csum_len;
520 	u32	request_mptcp : 1,  /* send MP_CAPABLE */
521 		request_join : 1,   /* send MP_JOIN */
522 		request_bkup : 1,
523 		mp_capable : 1,	    /* remote is MPTCP capable */
524 		mp_join : 1,	    /* remote is JOINing */
525 		pm_notified : 1,    /* PM hook called for established status */
526 		conn_finished : 1,
527 		map_valid : 1,
528 		map_csum_reqd : 1,
529 		map_data_fin : 1,
530 		mpc_map : 1,
531 		backup : 1,
532 		send_mp_prio : 1,
533 		send_mp_fail : 1,
534 		send_fastclose : 1,
535 		send_infinite_map : 1,
536 		remote_key_valid : 1,        /* received the peer key from */
537 		disposable : 1,	    /* ctx can be free at ulp release time */
538 		stale : 1,	    /* unable to snd/rcv data, do not use for xmit */
539 		valid_csum_seen : 1,        /* at least one csum validated */
540 		is_mptfo : 1,	    /* subflow is doing TFO */
541 		close_event_done : 1,       /* has done the post-closed part */
542 		mpc_drop : 1,	    /* the MPC option has been dropped in a rtx */
543 		__unused : 9;
544 	bool	data_avail;
545 	bool	scheduled;
546 	bool	pm_listener;	    /* a listener managed by the kernel PM? */
547 	bool	fully_established;  /* path validated */
548 	u32	remote_nonce;
549 	u64	thmac;
550 	u32	local_nonce;
551 	u32	remote_token;
552 	union {
553 		u8	hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */
554 		u64	iasn;	    /* initial ack sequence number, MPC subflows only */
555 	};
556 	s16	local_id;	    /* if negative not initialized yet */
557 	u8	remote_id;
558 	u8	reset_seen:1;
559 	u8	reset_transient:1;
560 	u8	reset_reason:4;
561 	u8	stale_count;
562 
563 	u32	subflow_id;
564 
565 	long	delegated_status;
566 	unsigned long	fail_tout;
567 
568 	);
569 
570 	struct	list_head delegated_node;   /* link into delegated_action, protected by local BH */
571 
572 	u32	setsockopt_seq;
573 	u32	stale_rcv_tstamp;
574 	int     cached_sndbuf;	    /* sndbuf size when last synced with the msk sndbuf,
575 				     * protected by the msk socket lock
576 				     */
577 
578 	struct	sock *tcp_sock;	    /* tcp sk backpointer */
579 	struct	sock *conn;	    /* parent mptcp_sock */
580 	const	struct inet_connection_sock_af_ops *icsk_af_ops;
581 	void	(*tcp_state_change)(struct sock *sk);
582 	void	(*tcp_error_report)(struct sock *sk);
583 
584 	struct	rcu_head rcu;
585 };
586 
587 static inline struct mptcp_subflow_context *
mptcp_subflow_ctx(const struct sock * sk)588 mptcp_subflow_ctx(const struct sock *sk)
589 {
590 	const struct inet_connection_sock *icsk = inet_csk(sk);
591 
592 	/* Use RCU on icsk_ulp_data only for sock diag code */
593 	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
594 }
595 
596 static inline struct sock *
mptcp_subflow_tcp_sock(const struct mptcp_subflow_context * subflow)597 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
598 {
599 	return subflow->tcp_sock;
600 }
601 
602 static inline void
mptcp_subflow_ctx_reset(struct mptcp_subflow_context * subflow)603 mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
604 {
605 	memset(&subflow->reset, 0, sizeof(subflow->reset));
606 	subflow->request_mptcp = 1;
607 	WRITE_ONCE(subflow->local_id, -1);
608 }
609 
610 /* Convert reset reasons in MPTCP to enum sk_rst_reason type */
611 static inline enum sk_rst_reason
sk_rst_convert_mptcp_reason(u32 reason)612 sk_rst_convert_mptcp_reason(u32 reason)
613 {
614 	switch (reason) {
615 	case MPTCP_RST_EUNSPEC:
616 		return SK_RST_REASON_MPTCP_RST_EUNSPEC;
617 	case MPTCP_RST_EMPTCP:
618 		return SK_RST_REASON_MPTCP_RST_EMPTCP;
619 	case MPTCP_RST_ERESOURCE:
620 		return SK_RST_REASON_MPTCP_RST_ERESOURCE;
621 	case MPTCP_RST_EPROHIBIT:
622 		return SK_RST_REASON_MPTCP_RST_EPROHIBIT;
623 	case MPTCP_RST_EWQ2BIG:
624 		return SK_RST_REASON_MPTCP_RST_EWQ2BIG;
625 	case MPTCP_RST_EBADPERF:
626 		return SK_RST_REASON_MPTCP_RST_EBADPERF;
627 	case MPTCP_RST_EMIDDLEBOX:
628 		return SK_RST_REASON_MPTCP_RST_EMIDDLEBOX;
629 	default:
630 		/* It should not happen, or else errors may occur
631 		 * in MPTCP layer
632 		 */
633 		return SK_RST_REASON_ERROR;
634 	}
635 }
636 
637 static inline void
mptcp_send_active_reset_reason(struct sock * sk)638 mptcp_send_active_reset_reason(struct sock *sk)
639 {
640 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
641 	enum sk_rst_reason reason;
642 
643 	reason = sk_rst_convert_mptcp_reason(subflow->reset_reason);
644 	tcp_send_active_reset(sk, GFP_ATOMIC, reason);
645 }
646 
647 static inline u64
mptcp_subflow_get_map_offset(const struct mptcp_subflow_context * subflow)648 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
649 {
650 	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
651 		      subflow->ssn_offset -
652 		      subflow->map_subflow_seq;
653 }
654 
655 static inline u64
mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context * subflow)656 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
657 {
658 	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
659 }
660 
661 void mptcp_subflow_process_delegated(struct sock *ssk, long actions);
662 
mptcp_subflow_delegate(struct mptcp_subflow_context * subflow,int action)663 static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
664 {
665 	long old, set_bits = BIT(MPTCP_DELEGATE_SCHEDULED) | BIT(action);
666 	struct mptcp_delegated_action *delegated;
667 	bool schedule;
668 
669 	/* the caller held the subflow bh socket lock */
670 	lockdep_assert_in_softirq();
671 
672 	/* The implied barrier pairs with tcp_release_cb_override()
673 	 * mptcp_napi_poll(), and ensures the below list check sees list
674 	 * updates done prior to delegated status bits changes
675 	 */
676 	old = set_mask_bits(&subflow->delegated_status, 0, set_bits);
677 	if (!(old & BIT(MPTCP_DELEGATE_SCHEDULED))) {
678 		if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node)))
679 			return;
680 
681 		local_lock_nested_bh(&mptcp_delegated_actions.bh_lock);
682 		delegated = this_cpu_ptr(&mptcp_delegated_actions);
683 		schedule = list_empty(&delegated->head);
684 		list_add_tail(&subflow->delegated_node, &delegated->head);
685 		local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
686 		sock_hold(mptcp_subflow_tcp_sock(subflow));
687 		if (schedule)
688 			napi_schedule(&delegated->napi);
689 	}
690 }
691 
692 static inline struct mptcp_subflow_context *
mptcp_subflow_delegated_next(struct mptcp_delegated_action * delegated)693 mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
694 {
695 	struct mptcp_subflow_context *ret;
696 
697 	local_lock_nested_bh(&mptcp_delegated_actions.bh_lock);
698 	if (list_empty(&delegated->head)) {
699 		local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
700 		return NULL;
701 	}
702 
703 	ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
704 	list_del_init(&ret->delegated_node);
705 	local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
706 	return ret;
707 }
708 
709 int mptcp_is_enabled(const struct net *net);
710 unsigned int mptcp_get_add_addr_timeout(const struct net *net);
711 int mptcp_is_checksum_enabled(const struct net *net);
712 int mptcp_allow_join_id0(const struct net *net);
713 unsigned int mptcp_stale_loss_cnt(const struct net *net);
714 unsigned int mptcp_close_timeout(const struct sock *sk);
715 int mptcp_get_pm_type(const struct net *net);
716 const char *mptcp_get_path_manager(const struct net *net);
717 const char *mptcp_get_scheduler(const struct net *net);
718 
719 void mptcp_active_disable(struct sock *sk);
720 bool mptcp_active_should_disable(struct sock *ssk);
721 void mptcp_active_enable(struct sock *sk);
722 
723 void mptcp_get_available_schedulers(char *buf, size_t maxlen);
724 void __mptcp_subflow_fully_established(struct mptcp_sock *msk,
725 				       struct mptcp_subflow_context *subflow,
726 				       const struct mptcp_options_received *mp_opt);
727 bool __mptcp_retransmit_pending_data(struct sock *sk);
728 void mptcp_check_and_set_pending(struct sock *sk);
729 void __mptcp_push_pending(struct sock *sk, unsigned int flags);
730 bool mptcp_subflow_data_available(struct sock *sk);
731 void __init mptcp_subflow_init(void);
732 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
733 void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
734 		     struct mptcp_subflow_context *subflow);
735 void __mptcp_subflow_send_ack(struct sock *ssk);
736 void mptcp_subflow_reset(struct sock *ssk);
737 void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
738 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
739 struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
740 bool __mptcp_close(struct sock *sk, long timeout);
741 void mptcp_cancel_work(struct sock *sk);
742 void __mptcp_unaccepted_force_close(struct sock *sk);
743 void mptcp_set_state(struct sock *sk, int state);
744 
745 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
746 			   const struct mptcp_addr_info *b, bool use_port);
747 void mptcp_local_address(const struct sock_common *skc,
748 			 struct mptcp_addr_info *addr);
749 void mptcp_remote_address(const struct sock_common *skc,
750 			  struct mptcp_addr_info *addr);
751 
752 /* called with sk socket lock held */
753 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_pm_local *local,
754 			    const struct mptcp_addr_info *remote);
755 int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
756 				struct socket **new_sock);
757 void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
758 			 struct sockaddr_storage *addr,
759 			 unsigned short family);
760 struct mptcp_sched_ops *mptcp_sched_find(const char *name);
761 int mptcp_validate_scheduler(struct mptcp_sched_ops *sched);
762 int mptcp_register_scheduler(struct mptcp_sched_ops *sched);
763 void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched);
764 void mptcp_sched_init(void);
765 int mptcp_init_sched(struct mptcp_sock *msk,
766 		     struct mptcp_sched_ops *sched);
767 void mptcp_release_sched(struct mptcp_sock *msk);
768 void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
769 				 bool scheduled);
770 struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
771 struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
772 int mptcp_sched_get_send(struct mptcp_sock *msk);
773 int mptcp_sched_get_retrans(struct mptcp_sock *msk);
774 
mptcp_data_avail(const struct mptcp_sock * msk)775 static inline u64 mptcp_data_avail(const struct mptcp_sock *msk)
776 {
777 	return READ_ONCE(msk->bytes_received) - READ_ONCE(msk->bytes_consumed);
778 }
779 
mptcp_epollin_ready(const struct sock * sk)780 static inline bool mptcp_epollin_ready(const struct sock *sk)
781 {
782 	u64 data_avail = mptcp_data_avail(mptcp_sk(sk));
783 
784 	if (!data_avail)
785 		return false;
786 
787 	/* mptcp doesn't have to deal with small skbs in the receive queue,
788 	 * as it can always coalesce them
789 	 */
790 	return (data_avail >= sk->sk_rcvlowat) ||
791 	       (mem_cgroup_sockets_enabled && sk->sk_memcg &&
792 		mem_cgroup_under_socket_pressure(sk->sk_memcg)) ||
793 	       READ_ONCE(tcp_memory_pressure);
794 }
795 
796 int mptcp_set_rcvlowat(struct sock *sk, int val);
797 
__tcp_can_send(const struct sock * ssk)798 static inline bool __tcp_can_send(const struct sock *ssk)
799 {
800 	/* only send if our side has not closed yet */
801 	return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
802 }
803 
__mptcp_subflow_active(struct mptcp_subflow_context * subflow)804 static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
805 {
806 	/* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
807 	if (subflow->request_join && !READ_ONCE(subflow->fully_established))
808 		return false;
809 
810 	return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
811 }
812 
813 void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
814 
815 bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
816 
817 void mptcp_subflow_drop_ctx(struct sock *ssk);
818 
mptcp_subflow_tcp_fallback(struct sock * sk,struct mptcp_subflow_context * ctx)819 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
820 					      struct mptcp_subflow_context *ctx)
821 {
822 	sk->sk_data_ready = sock_def_readable;
823 	sk->sk_state_change = ctx->tcp_state_change;
824 	sk->sk_write_space = sk_stream_write_space;
825 	sk->sk_error_report = ctx->tcp_error_report;
826 
827 	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
828 }
829 
830 void __init mptcp_proto_init(void);
831 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
832 int __init mptcp_proto_v6_init(void);
833 #endif
834 
835 struct sock *mptcp_sk_clone_init(const struct sock *sk,
836 				 const struct mptcp_options_received *mp_opt,
837 				 struct sock *ssk,
838 				 struct request_sock *req);
839 void mptcp_get_options(const struct sk_buff *skb,
840 		       struct mptcp_options_received *mp_opt);
841 
842 void mptcp_finish_connect(struct sock *sk);
843 void __mptcp_sync_state(struct sock *sk, int state);
844 void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout);
845 
mptcp_stop_tout_timer(struct sock * sk)846 static inline void mptcp_stop_tout_timer(struct sock *sk)
847 {
848 	if (!inet_csk(sk)->icsk_mtup.probe_timestamp)
849 		return;
850 
851 	sk_stop_timer(sk, &sk->sk_timer);
852 	inet_csk(sk)->icsk_mtup.probe_timestamp = 0;
853 }
854 
mptcp_set_close_tout(struct sock * sk,unsigned long tout)855 static inline void mptcp_set_close_tout(struct sock *sk, unsigned long tout)
856 {
857 	/* avoid 0 timestamp, as that means no close timeout */
858 	inet_csk(sk)->icsk_mtup.probe_timestamp = tout ? : 1;
859 }
860 
mptcp_start_tout_timer(struct sock * sk)861 static inline void mptcp_start_tout_timer(struct sock *sk)
862 {
863 	mptcp_set_close_tout(sk, tcp_jiffies32);
864 	mptcp_reset_tout_timer(mptcp_sk(sk), 0);
865 }
866 
mptcp_is_fully_established(struct sock * sk)867 static inline bool mptcp_is_fully_established(struct sock *sk)
868 {
869 	return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
870 	       READ_ONCE(mptcp_sk(sk)->fully_established);
871 }
872 
873 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
874 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
875 bool mptcp_finish_join(struct sock *sk);
876 bool mptcp_schedule_work(struct sock *sk);
877 int mptcp_setsockopt(struct sock *sk, int level, int optname,
878 		     sockptr_t optval, unsigned int optlen);
879 int mptcp_getsockopt(struct sock *sk, int level, int optname,
880 		     char __user *optval, int __user *option);
881 
882 u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
mptcp_expand_seq(u64 old_seq,u64 cur_seq,bool use_64bit)883 static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
884 {
885 	if (use_64bit)
886 		return cur_seq;
887 
888 	return __mptcp_expand_seq(old_seq, cur_seq);
889 }
890 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
891 void __mptcp_data_acked(struct sock *sk);
892 void __mptcp_error_report(struct sock *sk);
893 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
mptcp_data_fin_enabled(const struct mptcp_sock * msk)894 static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
895 {
896 	return READ_ONCE(msk->snd_data_fin_enable) &&
897 	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
898 }
899 
mptcp_notsent_lowat(const struct sock * sk)900 static inline u32 mptcp_notsent_lowat(const struct sock *sk)
901 {
902 	struct net *net = sock_net(sk);
903 	u32 val;
904 
905 	val = READ_ONCE(mptcp_sk(sk)->notsent_lowat);
906 	return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat);
907 }
908 
mptcp_stream_memory_free(const struct sock * sk,int wake)909 static inline bool mptcp_stream_memory_free(const struct sock *sk, int wake)
910 {
911 	const struct mptcp_sock *msk = mptcp_sk(sk);
912 	u32 notsent_bytes;
913 
914 	notsent_bytes = READ_ONCE(msk->write_seq) - READ_ONCE(msk->snd_nxt);
915 	return (notsent_bytes << wake) < mptcp_notsent_lowat(sk);
916 }
917 
__mptcp_stream_is_writeable(const struct sock * sk,int wake)918 static inline bool __mptcp_stream_is_writeable(const struct sock *sk, int wake)
919 {
920 	return mptcp_stream_memory_free(sk, wake) &&
921 	       __sk_stream_is_writeable(sk, wake);
922 }
923 
mptcp_write_space(struct sock * sk)924 static inline void mptcp_write_space(struct sock *sk)
925 {
926 	/* pairs with memory barrier in mptcp_poll */
927 	smp_mb();
928 	if (mptcp_stream_memory_free(sk, 1))
929 		sk_stream_write_space(sk);
930 }
931 
__mptcp_sync_sndbuf(struct sock * sk)932 static inline void __mptcp_sync_sndbuf(struct sock *sk)
933 {
934 	struct mptcp_subflow_context *subflow;
935 	int ssk_sndbuf, new_sndbuf;
936 
937 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
938 		return;
939 
940 	new_sndbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[0]);
941 	mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
942 		ssk_sndbuf =  READ_ONCE(mptcp_subflow_tcp_sock(subflow)->sk_sndbuf);
943 
944 		subflow->cached_sndbuf = ssk_sndbuf;
945 		new_sndbuf += ssk_sndbuf;
946 	}
947 
948 	/* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */
949 	WRITE_ONCE(sk->sk_sndbuf, new_sndbuf);
950 	mptcp_write_space(sk);
951 }
952 
953 /* The called held both the msk socket and the subflow socket locks,
954  * possibly under BH
955  */
__mptcp_propagate_sndbuf(struct sock * sk,struct sock * ssk)956 static inline void __mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
957 {
958 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
959 
960 	if (READ_ONCE(ssk->sk_sndbuf) != subflow->cached_sndbuf)
961 		__mptcp_sync_sndbuf(sk);
962 }
963 
964 /* the caller held only the subflow socket lock, either in process or
965  * BH context. Additionally this can be called under the msk data lock,
966  * so we can't acquire such lock here: let the delegate action acquires
967  * the needed locks in suitable order.
968  */
mptcp_propagate_sndbuf(struct sock * sk,struct sock * ssk)969 static inline void mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
970 {
971 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
972 
973 	if (likely(READ_ONCE(ssk->sk_sndbuf) == subflow->cached_sndbuf))
974 		return;
975 
976 	local_bh_disable();
977 	mptcp_subflow_delegate(subflow, MPTCP_DELEGATE_SNDBUF);
978 	local_bh_enable();
979 }
980 
981 void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
982 
983 #define MPTCP_TOKEN_MAX_RETRIES	4
984 
985 void __init mptcp_token_init(void);
mptcp_token_init_request(struct request_sock * req)986 static inline void mptcp_token_init_request(struct request_sock *req)
987 {
988 	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
989 }
990 
991 int mptcp_token_new_request(struct request_sock *req);
992 void mptcp_token_destroy_request(struct request_sock *req);
993 int mptcp_token_new_connect(struct sock *ssk);
994 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
995 			struct mptcp_sock *msk);
996 bool mptcp_token_exists(u32 token);
997 struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
998 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
999 					 long *s_num);
1000 void mptcp_token_destroy(struct mptcp_sock *msk);
1001 
1002 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
1003 
1004 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
1005 __sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
1006 
1007 void __init mptcp_pm_init(void);
1008 void mptcp_pm_data_init(struct mptcp_sock *msk);
1009 void mptcp_pm_data_reset(struct mptcp_sock *msk);
1010 void mptcp_pm_destroy(struct mptcp_sock *msk);
1011 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1012 			struct mptcp_addr_info *addr);
1013 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1014 			 bool require_family,
1015 			 struct mptcp_pm_addr_entry *entry);
1016 bool mptcp_pm_addr_families_match(const struct sock *sk,
1017 				  const struct mptcp_addr_info *loc,
1018 				  const struct mptcp_addr_info *rem);
1019 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
1020 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
1021 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk);
1022 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
1023 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
1024 void mptcp_pm_subflow_established(struct mptcp_sock *msk);
1025 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
1026 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
1027 				 const struct mptcp_subflow_context *subflow);
1028 void mptcp_pm_add_addr_received(const struct sock *ssk,
1029 				const struct mptcp_addr_info *addr);
1030 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
1031 			      const struct mptcp_addr_info *addr);
1032 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
1033 void mptcp_pm_send_ack(struct mptcp_sock *msk,
1034 		       struct mptcp_subflow_context *subflow,
1035 		       bool prio, bool backup);
1036 void mptcp_pm_addr_send_ack(struct mptcp_sock *msk);
1037 void mptcp_pm_nl_rm_addr(struct mptcp_sock *msk, u8 rm_id);
1038 void mptcp_pm_rm_subflow(struct mptcp_sock *msk,
1039 			 const struct mptcp_rm_list *rm_list);
1040 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
1041 			       const struct mptcp_rm_list *rm_list);
1042 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
1043 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
1044 int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
1045 			      struct mptcp_addr_info *addr,
1046 			      struct mptcp_addr_info *rem,
1047 			      u8 bkup);
1048 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
1049 			      const struct mptcp_addr_info *addr);
1050 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
1051 struct mptcp_pm_add_entry *
1052 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
1053 		       const struct mptcp_addr_info *addr, bool check_id);
1054 bool mptcp_lookup_subflow_by_saddr(const struct list_head *list,
1055 				   const struct mptcp_addr_info *saddr);
1056 bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
1057 				     const struct mptcp_addr_info *addr);
1058 int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
1059 			  struct genl_info *info);
1060 int mptcp_userspace_pm_set_flags(struct mptcp_pm_addr_entry *local,
1061 				 struct genl_info *info);
1062 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
1063 			   const struct mptcp_addr_info *addr,
1064 			   bool echo);
1065 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
1066 void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
1067 				struct mptcp_pm_addr_entry *entry);
1068 
1069 /* the default path manager, used in mptcp_pm_unregister */
1070 extern struct mptcp_pm_ops mptcp_pm_kernel;
1071 
1072 struct mptcp_pm_ops *mptcp_pm_find(const char *name);
1073 int mptcp_pm_register(struct mptcp_pm_ops *pm_ops);
1074 void mptcp_pm_unregister(struct mptcp_pm_ops *pm_ops);
1075 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops);
1076 void mptcp_pm_get_available(char *buf, size_t maxlen);
1077 
1078 void mptcp_userspace_pm_free_local_addr_list(struct mptcp_sock *msk);
1079 
1080 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
1081 		 const struct sock *ssk, gfp_t gfp);
1082 void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
1083 void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
1084 void mptcp_event_pm_listener(const struct sock *ssk,
1085 			     enum mptcp_event_type event);
1086 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
1087 
1088 void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow,
1089 					      struct request_sock *req);
1090 int mptcp_pm_genl_fill_addr(struct sk_buff *msg,
1091 			    struct netlink_callback *cb,
1092 			    struct mptcp_pm_addr_entry *entry);
1093 
mptcp_pm_should_add_signal(struct mptcp_sock * msk)1094 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
1095 {
1096 	return READ_ONCE(msk->pm.addr_signal) &
1097 		(BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
1098 }
1099 
mptcp_pm_should_add_signal_addr(struct mptcp_sock * msk)1100 static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
1101 {
1102 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
1103 }
1104 
mptcp_pm_should_add_signal_echo(struct mptcp_sock * msk)1105 static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
1106 {
1107 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
1108 }
1109 
mptcp_pm_should_rm_signal(struct mptcp_sock * msk)1110 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
1111 {
1112 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
1113 }
1114 
mptcp_pm_is_userspace(const struct mptcp_sock * msk)1115 static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
1116 {
1117 	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
1118 }
1119 
mptcp_pm_is_kernel(const struct mptcp_sock * msk)1120 static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
1121 {
1122 	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
1123 }
1124 
mptcp_add_addr_len(int family,bool echo,bool port)1125 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
1126 {
1127 	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
1128 
1129 	if (family == AF_INET6)
1130 		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
1131 	if (!echo)
1132 		len += MPTCPOPT_THMAC_LEN;
1133 	/* account for 2 trailing 'nop' options */
1134 	if (port)
1135 		len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
1136 
1137 	return len;
1138 }
1139 
mptcp_rm_addr_len(const struct mptcp_rm_list * rm_list)1140 static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
1141 {
1142 	if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
1143 		return -EINVAL;
1144 
1145 	return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
1146 }
1147 
1148 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
1149 			      unsigned int opt_size, unsigned int remaining,
1150 			      struct mptcp_addr_info *addr, bool *echo,
1151 			      bool *drop_other_suboptions);
1152 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
1153 			     struct mptcp_rm_list *rm_list);
1154 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
1155 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
1156 			     struct mptcp_pm_addr_entry *skc);
1157 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
1158 				    struct mptcp_pm_addr_entry *skc);
1159 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
1160 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1161 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1162 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
1163 			  struct netlink_callback *cb);
1164 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
1165 				 struct netlink_callback *cb);
1166 int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
1167 			 struct genl_info *info);
1168 int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
1169 				struct genl_info *info);
1170 
subflow_get_local_id(const struct mptcp_subflow_context * subflow)1171 static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)
1172 {
1173 	int local_id = READ_ONCE(subflow->local_id);
1174 
1175 	if (local_id < 0)
1176 		return 0;
1177 	return local_id;
1178 }
1179 
1180 void __init mptcp_pm_kernel_register(void);
1181 void __init mptcp_pm_userspace_register(void);
1182 void __init mptcp_pm_nl_init(void);
1183 void mptcp_pm_worker(struct mptcp_sock *msk);
1184 void __mptcp_pm_kernel_worker(struct mptcp_sock *msk);
1185 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
1186 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
1187 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
1188 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
1189 
1190 /* called under PM lock */
__mptcp_pm_close_subflow(struct mptcp_sock * msk)1191 static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
1192 {
1193 	if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
1194 		WRITE_ONCE(msk->pm.accept_subflow, true);
1195 }
1196 
mptcp_pm_close_subflow(struct mptcp_sock * msk)1197 static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
1198 {
1199 	spin_lock_bh(&msk->pm.lock);
1200 	__mptcp_pm_close_subflow(msk);
1201 	spin_unlock_bh(&msk->pm.lock);
1202 }
1203 
1204 void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
1205 
mptcp_get_ext(const struct sk_buff * skb)1206 static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
1207 {
1208 	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
1209 }
1210 
1211 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
1212 
__mptcp_check_fallback(const struct mptcp_sock * msk)1213 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
1214 {
1215 	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
1216 }
1217 
mptcp_check_fallback(const struct sock * sk)1218 static inline bool mptcp_check_fallback(const struct sock *sk)
1219 {
1220 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1221 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
1222 
1223 	return __mptcp_check_fallback(msk);
1224 }
1225 
__mptcp_has_initial_subflow(const struct mptcp_sock * msk)1226 static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
1227 {
1228 	struct sock *ssk = READ_ONCE(msk->first);
1229 
1230 	return ssk && ((1 << inet_sk_state_load(ssk)) &
1231 		       (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1232 			TCPF_SYN_RECV | TCPF_LISTEN));
1233 }
1234 
1235 bool __mptcp_try_fallback(struct mptcp_sock *msk, int fb_mib);
1236 
mptcp_try_fallback(struct sock * ssk,int fb_mib)1237 static inline bool mptcp_try_fallback(struct sock *ssk, int fb_mib)
1238 {
1239 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
1240 	struct sock *sk = subflow->conn;
1241 	struct mptcp_sock *msk;
1242 
1243 	msk = mptcp_sk(sk);
1244 	if (!__mptcp_try_fallback(msk, fb_mib))
1245 		return false;
1246 	if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
1247 		gfp_t saved_allocation = ssk->sk_allocation;
1248 
1249 		/* we are in a atomic (BH) scope, override ssk default for data
1250 		 * fin allocation
1251 		 */
1252 		ssk->sk_allocation = GFP_ATOMIC;
1253 		ssk->sk_shutdown |= SEND_SHUTDOWN;
1254 		tcp_shutdown(ssk, SEND_SHUTDOWN);
1255 		ssk->sk_allocation = saved_allocation;
1256 	}
1257 	return true;
1258 }
1259 
mptcp_early_fallback(struct mptcp_sock * msk,struct mptcp_subflow_context * subflow,int fb_mib)1260 static inline void mptcp_early_fallback(struct mptcp_sock *msk,
1261 					struct mptcp_subflow_context *subflow,
1262 					int fb_mib)
1263 {
1264 	subflow->request_mptcp = 0;
1265 	WARN_ON_ONCE(!__mptcp_try_fallback(msk, fb_mib));
1266 }
1267 
mptcp_check_infinite_map(struct sk_buff * skb)1268 static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
1269 {
1270 	struct mptcp_ext *mpext;
1271 
1272 	mpext = skb ? mptcp_get_ext(skb) : NULL;
1273 	if (mpext && mpext->infinite_map)
1274 		return true;
1275 
1276 	return false;
1277 }
1278 
is_active_ssk(struct mptcp_subflow_context * subflow)1279 static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
1280 {
1281 	return (subflow->request_mptcp || subflow->request_join);
1282 }
1283 
subflow_simultaneous_connect(struct sock * sk)1284 static inline bool subflow_simultaneous_connect(struct sock *sk)
1285 {
1286 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1287 
1288 	return (1 << sk->sk_state) &
1289 	       (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING) &&
1290 	       is_active_ssk(subflow) &&
1291 	       !subflow->conn_finished;
1292 }
1293 
1294 #ifdef CONFIG_SYN_COOKIES
1295 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1296 				       struct sk_buff *skb);
1297 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1298 					struct sk_buff *skb);
1299 void __init mptcp_join_cookie_init(void);
1300 #else
1301 static inline void
subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock * subflow_req,struct sk_buff * skb)1302 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1303 				  struct sk_buff *skb) {}
1304 static inline bool
mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock * subflow_req,struct sk_buff * skb)1305 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1306 				   struct sk_buff *skb)
1307 {
1308 	return false;
1309 }
1310 
mptcp_join_cookie_init(void)1311 static inline void mptcp_join_cookie_init(void) {}
1312 #endif
1313 
1314 #endif /* __MPTCP_PROTOCOL_H */
1315