1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __FS_CEPH_MESSENGER_H
3 #define __FS_CEPH_MESSENGER_H
4 
5 #include <linux/bvec.h>
6 #include <linux/crypto.h>
7 #include <linux/kref.h>
8 #include <linux/mutex.h>
9 #include <linux/net.h>
10 #include <linux/radix-tree.h>
11 #include <linux/uio.h>
12 #include <linux/workqueue.h>
13 #include <net/net_namespace.h>
14 
15 #include <linux/ceph/types.h>
16 #include <linux/ceph/buffer.h>
17 
18 struct ceph_msg;
19 struct ceph_connection;
20 
21 /*
22  * Ceph defines these callbacks for handling connection events.
23  */
24 struct ceph_connection_operations {
25 	struct ceph_connection *(*get)(struct ceph_connection *);
26 	void (*put)(struct ceph_connection *);
27 
28 	/* handle an incoming message. */
29 	void (*dispatch) (struct ceph_connection *con, struct ceph_msg *m);
30 
31 	/* authorize an outgoing connection */
32 	struct ceph_auth_handshake *(*get_authorizer) (
33 				struct ceph_connection *con,
34 			       int *proto, int force_new);
35 	int (*add_authorizer_challenge)(struct ceph_connection *con,
36 					void *challenge_buf,
37 					int challenge_buf_len);
38 	int (*verify_authorizer_reply) (struct ceph_connection *con);
39 	int (*invalidate_authorizer)(struct ceph_connection *con);
40 
41 	/* there was some error on the socket (disconnect, whatever) */
42 	void (*fault) (struct ceph_connection *con);
43 
44 	/* a remote host as terminated a message exchange session, and messages
45 	 * we sent (or they tried to send us) may be lost. */
46 	void (*peer_reset) (struct ceph_connection *con);
47 
48 	struct ceph_msg * (*alloc_msg) (struct ceph_connection *con,
49 					struct ceph_msg_header *hdr,
50 					int *skip);
51 
52 	void (*reencode_message) (struct ceph_msg *msg);
53 
54 	int (*sign_message) (struct ceph_msg *msg);
55 	int (*check_message_signature) (struct ceph_msg *msg);
56 
57 	/* msgr2 authentication exchange */
58 	int (*get_auth_request)(struct ceph_connection *con,
59 				void *buf, int *buf_len,
60 				void **authorizer, int *authorizer_len);
61 	int (*handle_auth_reply_more)(struct ceph_connection *con,
62 				      void *reply, int reply_len,
63 				      void *buf, int *buf_len,
64 				      void **authorizer, int *authorizer_len);
65 	int (*handle_auth_done)(struct ceph_connection *con,
66 				u64 global_id, void *reply, int reply_len,
67 				u8 *session_key, int *session_key_len,
68 				u8 *con_secret, int *con_secret_len);
69 	int (*handle_auth_bad_method)(struct ceph_connection *con,
70 				      int used_proto, int result,
71 				      const int *allowed_protos, int proto_cnt,
72 				      const int *allowed_modes, int mode_cnt);
73 };
74 
75 /* use format string %s%lld */
76 #define ENTITY_NAME(n) ceph_entity_type_name((n).type), le64_to_cpu((n).num)
77 
78 struct ceph_messenger {
79 	struct ceph_entity_inst inst;    /* my name+address */
80 	struct ceph_entity_addr my_enc_addr;
81 
82 	atomic_t stopping;
83 	possible_net_t net;
84 
85 	/*
86 	 * the global_seq counts connections i (attempt to) initiate
87 	 * in order to disambiguate certain connect race conditions.
88 	 */
89 	u32 global_seq;
90 	spinlock_t global_seq_lock;
91 };
92 
93 enum ceph_msg_data_type {
94 	CEPH_MSG_DATA_NONE,	/* message contains no data payload */
95 	CEPH_MSG_DATA_PAGES,	/* data source/destination is a page array */
96 	CEPH_MSG_DATA_PAGELIST,	/* data source/destination is a pagelist */
97 #ifdef CONFIG_BLOCK
98 	CEPH_MSG_DATA_BIO,	/* data source/destination is a bio list */
99 #endif /* CONFIG_BLOCK */
100 	CEPH_MSG_DATA_BVECS,	/* data source/destination is a bio_vec array */
101 };
102 
103 #ifdef CONFIG_BLOCK
104 
105 struct ceph_bio_iter {
106 	struct bio *bio;
107 	struct bvec_iter iter;
108 };
109 
110 #define __ceph_bio_iter_advance_step(it, n, STEP) do {			      \
111 	unsigned int __n = (n), __cur_n;				      \
112 									      \
113 	while (__n) {							      \
114 		BUG_ON(!(it)->iter.bi_size);				      \
115 		__cur_n = min((it)->iter.bi_size, __n);			      \
116 		(void)(STEP);						      \
117 		bio_advance_iter((it)->bio, &(it)->iter, __cur_n);	      \
118 		if (!(it)->iter.bi_size && (it)->bio->bi_next) {	      \
119 			dout("__ceph_bio_iter_advance_step next bio\n");      \
120 			(it)->bio = (it)->bio->bi_next;			      \
121 			(it)->iter = (it)->bio->bi_iter;		      \
122 		}							      \
123 		__n -= __cur_n;						      \
124 	}								      \
125 } while (0)
126 
127 /*
128  * Advance @it by @n bytes.
129  */
130 #define ceph_bio_iter_advance(it, n)					      \
131 	__ceph_bio_iter_advance_step(it, n, 0)
132 
133 /*
134  * Advance @it by @n bytes, executing BVEC_STEP for each bio_vec.
135  */
136 #define ceph_bio_iter_advance_step(it, n, BVEC_STEP)			      \
137 	__ceph_bio_iter_advance_step(it, n, ({				      \
138 		struct bio_vec bv;					      \
139 		struct bvec_iter __cur_iter;				      \
140 									      \
141 		__cur_iter = (it)->iter;				      \
142 		__cur_iter.bi_size = __cur_n;				      \
143 		__bio_for_each_segment(bv, (it)->bio, __cur_iter, __cur_iter) \
144 			(void)(BVEC_STEP);				      \
145 	}))
146 
147 #endif /* CONFIG_BLOCK */
148 
149 struct ceph_bvec_iter {
150 	struct bio_vec *bvecs;
151 	struct bvec_iter iter;
152 };
153 
154 #define __ceph_bvec_iter_advance_step(it, n, STEP) do {			      \
155 	BUG_ON((n) > (it)->iter.bi_size);				      \
156 	(void)(STEP);							      \
157 	bvec_iter_advance((it)->bvecs, &(it)->iter, (n));		      \
158 } while (0)
159 
160 /*
161  * Advance @it by @n bytes.
162  */
163 #define ceph_bvec_iter_advance(it, n)					      \
164 	__ceph_bvec_iter_advance_step(it, n, 0)
165 
166 /*
167  * Advance @it by @n bytes, executing BVEC_STEP for each bio_vec.
168  */
169 #define ceph_bvec_iter_advance_step(it, n, BVEC_STEP)			      \
170 	__ceph_bvec_iter_advance_step(it, n, ({				      \
171 		struct bio_vec bv;					      \
172 		struct bvec_iter __cur_iter;				      \
173 									      \
174 		__cur_iter = (it)->iter;				      \
175 		__cur_iter.bi_size = (n);				      \
176 		for_each_bvec(bv, (it)->bvecs, __cur_iter, __cur_iter)	      \
177 			(void)(BVEC_STEP);				      \
178 	}))
179 
180 #define ceph_bvec_iter_shorten(it, n) do {				      \
181 	BUG_ON((n) > (it)->iter.bi_size);				      \
182 	(it)->iter.bi_size = (n);					      \
183 } while (0)
184 
185 struct ceph_msg_data {
186 	enum ceph_msg_data_type		type;
187 	union {
188 #ifdef CONFIG_BLOCK
189 		struct {
190 			struct ceph_bio_iter	bio_pos;
191 			u32			bio_length;
192 		};
193 #endif /* CONFIG_BLOCK */
194 		struct ceph_bvec_iter	bvec_pos;
195 		struct {
196 			struct page	**pages;
197 			size_t		length;		/* total # bytes */
198 			unsigned int	alignment;	/* first page */
199 			bool		own_pages;
200 		};
201 		struct ceph_pagelist	*pagelist;
202 	};
203 };
204 
205 struct ceph_msg_data_cursor {
206 	size_t			total_resid;	/* across all data items */
207 
208 	struct ceph_msg_data	*data;		/* current data item */
209 	size_t			resid;		/* bytes not yet consumed */
210 	bool			last_piece;	/* current is last piece */
211 	bool			need_crc;	/* crc update needed */
212 	union {
213 #ifdef CONFIG_BLOCK
214 		struct ceph_bio_iter	bio_iter;
215 #endif /* CONFIG_BLOCK */
216 		struct bvec_iter	bvec_iter;
217 		struct {				/* pages */
218 			unsigned int	page_offset;	/* offset in page */
219 			unsigned short	page_index;	/* index in array */
220 			unsigned short	page_count;	/* pages in array */
221 		};
222 		struct {				/* pagelist */
223 			struct page	*page;		/* page from list */
224 			size_t		offset;		/* bytes from list */
225 		};
226 	};
227 };
228 
229 /*
230  * a single message.  it contains a header (src, dest, message type, etc.),
231  * footer (crc values, mainly), a "front" message body, and possibly a
232  * data payload (stored in some number of pages).
233  */
234 struct ceph_msg {
235 	struct ceph_msg_header hdr;	/* header */
236 	union {
237 		struct ceph_msg_footer footer;		/* footer */
238 		struct ceph_msg_footer_old old_footer;	/* old format footer */
239 	};
240 	struct kvec front;              /* unaligned blobs of message */
241 	struct ceph_buffer *middle;
242 
243 	size_t				data_length;
244 	struct ceph_msg_data		*data;
245 	int				num_data_items;
246 	int				max_data_items;
247 	struct ceph_msg_data_cursor	cursor;
248 
249 	struct ceph_connection *con;
250 	struct list_head list_head;	/* links for connection lists */
251 
252 	struct kref kref;
253 	bool more_to_follow;
254 	bool needs_out_seq;
255 	int front_alloc_len;
256 
257 	struct ceph_msgpool *pool;
258 };
259 
260 /*
261  * connection states
262  */
263 #define CEPH_CON_S_CLOSED		1
264 #define CEPH_CON_S_PREOPEN		2
265 #define CEPH_CON_S_V1_BANNER		3
266 #define CEPH_CON_S_V1_CONNECT_MSG	4
267 #define CEPH_CON_S_V2_BANNER_PREFIX	5
268 #define CEPH_CON_S_V2_BANNER_PAYLOAD	6
269 #define CEPH_CON_S_V2_HELLO		7
270 #define CEPH_CON_S_V2_AUTH		8
271 #define CEPH_CON_S_V2_AUTH_SIGNATURE	9
272 #define CEPH_CON_S_V2_SESSION_CONNECT	10
273 #define CEPH_CON_S_V2_SESSION_RECONNECT	11
274 #define CEPH_CON_S_OPEN			12
275 #define CEPH_CON_S_STANDBY		13
276 
277 /*
278  * ceph_connection flag bits
279  */
280 #define CEPH_CON_F_LOSSYTX		0  /* we can close channel or drop
281 					      messages on errors */
282 #define CEPH_CON_F_KEEPALIVE_PENDING	1  /* we need to send a keepalive */
283 #define CEPH_CON_F_WRITE_PENDING	2  /* we have data ready to send */
284 #define CEPH_CON_F_SOCK_CLOSED		3  /* socket state changed to closed */
285 #define CEPH_CON_F_BACKOFF		4  /* need to retry queuing delayed
286 					      work */
287 
288 /* ceph connection fault delay defaults, for exponential backoff */
289 #define BASE_DELAY_INTERVAL	(HZ / 4)
290 #define MAX_DELAY_INTERVAL	(15 * HZ)
291 
292 struct ceph_connection_v1_info {
293 	struct kvec out_kvec[8],         /* sending header/footer data */
294 		*out_kvec_cur;
295 	int out_kvec_left;   /* kvec's left in out_kvec */
296 	int out_skip;        /* skip this many bytes */
297 	int out_kvec_bytes;  /* total bytes left */
298 	bool out_more;       /* there is more data after the kvecs */
299 	bool out_msg_done;
300 
301 	struct ceph_auth_handshake *auth;
302 	int auth_retry;       /* true if we need a newer authorizer */
303 
304 	/* connection negotiation temps */
305 	u8 in_banner[CEPH_BANNER_MAX_LEN];
306 	struct ceph_entity_addr actual_peer_addr;
307 	struct ceph_entity_addr peer_addr_for_me;
308 	struct ceph_msg_connect out_connect;
309 	struct ceph_msg_connect_reply in_reply;
310 
311 	int in_base_pos;     /* bytes read */
312 
313 	/* message in temps */
314 	u8 in_tag;           /* protocol control byte */
315 	struct ceph_msg_header in_hdr;
316 	__le64 in_temp_ack;  /* for reading an ack */
317 
318 	/* message out temps */
319 	struct ceph_msg_header out_hdr;
320 	__le64 out_temp_ack;  /* for writing an ack */
321 	struct ceph_timespec out_temp_keepalive2;  /* for writing keepalive2
322 						      stamp */
323 
324 	u32 connect_seq;      /* identify the most recent connection
325 				 attempt for this session */
326 	u32 peer_global_seq;  /* peer's global seq for this connection */
327 };
328 
329 #define CEPH_CRC_LEN			4
330 #define CEPH_GCM_KEY_LEN		16
331 #define CEPH_GCM_IV_LEN			sizeof(struct ceph_gcm_nonce)
332 #define CEPH_GCM_BLOCK_LEN		16
333 #define CEPH_GCM_TAG_LEN		16
334 
335 #define CEPH_PREAMBLE_LEN		32
336 #define CEPH_PREAMBLE_INLINE_LEN	48
337 #define CEPH_PREAMBLE_PLAIN_LEN		CEPH_PREAMBLE_LEN
338 #define CEPH_PREAMBLE_SECURE_LEN	(CEPH_PREAMBLE_LEN +		\
339 					 CEPH_PREAMBLE_INLINE_LEN +	\
340 					 CEPH_GCM_TAG_LEN)
341 #define CEPH_EPILOGUE_PLAIN_LEN		(1 + 3 * CEPH_CRC_LEN)
342 #define CEPH_EPILOGUE_SECURE_LEN	(CEPH_GCM_BLOCK_LEN + CEPH_GCM_TAG_LEN)
343 
344 #define CEPH_FRAME_MAX_SEGMENT_COUNT	4
345 
346 struct ceph_frame_desc {
347 	int fd_tag;  /* FRAME_TAG_* */
348 	int fd_seg_cnt;
349 	int fd_lens[CEPH_FRAME_MAX_SEGMENT_COUNT];  /* logical */
350 	int fd_aligns[CEPH_FRAME_MAX_SEGMENT_COUNT];
351 };
352 
353 struct ceph_gcm_nonce {
354 	__le32 fixed;
355 	__le64 counter __packed;
356 };
357 
358 struct ceph_connection_v2_info {
359 	struct iov_iter in_iter;
360 	struct kvec in_kvecs[5];  /* recvmsg */
361 	struct bio_vec in_bvec;  /* recvmsg (in_cursor) */
362 	int in_kvec_cnt;
363 	int in_state;  /* IN_S_* */
364 
365 	struct iov_iter out_iter;
366 	struct kvec out_kvecs[8];  /* sendmsg */
367 	struct bio_vec out_bvec;  /* sendpage (out_cursor, out_zero),
368 				     sendmsg (out_enc_pages) */
369 	int out_kvec_cnt;
370 	int out_state;  /* OUT_S_* */
371 
372 	int out_zero;  /* # of zero bytes to send */
373 	bool out_iter_sendpage;  /* use sendpage if possible */
374 
375 	struct ceph_frame_desc in_desc;
376 	struct ceph_msg_data_cursor in_cursor;
377 	struct ceph_msg_data_cursor out_cursor;
378 
379 	struct crypto_shash *hmac_tfm;  /* post-auth signature */
380 	struct crypto_aead *gcm_tfm;  /* on-wire encryption */
381 	struct aead_request *gcm_req;
382 	struct crypto_wait gcm_wait;
383 	struct ceph_gcm_nonce in_gcm_nonce;
384 	struct ceph_gcm_nonce out_gcm_nonce;
385 
386 	struct page **in_enc_pages;
387 	int in_enc_page_cnt;
388 	int in_enc_resid;
389 	int in_enc_i;
390 	struct page **out_enc_pages;
391 	int out_enc_page_cnt;
392 	int out_enc_resid;
393 	int out_enc_i;
394 
395 	int con_mode;  /* CEPH_CON_MODE_* */
396 
397 	void *conn_bufs[16];
398 	int conn_buf_cnt;
399 
400 	struct kvec in_sign_kvecs[8];
401 	struct kvec out_sign_kvecs[8];
402 	int in_sign_kvec_cnt;
403 	int out_sign_kvec_cnt;
404 
405 	u64 client_cookie;
406 	u64 server_cookie;
407 	u64 global_seq;
408 	u64 connect_seq;
409 	u64 peer_global_seq;
410 
411 	u8 in_buf[CEPH_PREAMBLE_SECURE_LEN];
412 	u8 out_buf[CEPH_PREAMBLE_SECURE_LEN];
413 	struct {
414 		u8 late_status;  /* FRAME_LATE_STATUS_* */
415 		union {
416 			struct {
417 				u32 front_crc;
418 				u32 middle_crc;
419 				u32 data_crc;
420 			} __packed;
421 			u8 pad[CEPH_GCM_BLOCK_LEN - 1];
422 		};
423 	} out_epil;
424 };
425 
426 /*
427  * A single connection with another host.
428  *
429  * We maintain a queue of outgoing messages, and some session state to
430  * ensure that we can preserve the lossless, ordered delivery of
431  * messages in the case of a TCP disconnect.
432  */
433 struct ceph_connection {
434 	void *private;
435 
436 	const struct ceph_connection_operations *ops;
437 
438 	struct ceph_messenger *msgr;
439 
440 	int state;  /* CEPH_CON_S_* */
441 	atomic_t sock_state;
442 	struct socket *sock;
443 
444 	unsigned long flags;  /* CEPH_CON_F_* */
445 	const char *error_msg;  /* error message, if any */
446 
447 	struct ceph_entity_name peer_name; /* peer name */
448 	struct ceph_entity_addr peer_addr; /* peer address */
449 	u64 peer_features;
450 
451 	struct mutex mutex;
452 
453 	/* out queue */
454 	struct list_head out_queue;
455 	struct list_head out_sent;   /* sending or sent but unacked */
456 	u64 out_seq;		     /* last message queued for send */
457 
458 	u64 in_seq, in_seq_acked;  /* last message received, acked */
459 
460 	struct ceph_msg *in_msg;
461 	struct ceph_msg *out_msg;        /* sending message (== tail of
462 					    out_sent) */
463 
464 	struct page *bounce_page;
465 	u32 in_front_crc, in_middle_crc, in_data_crc;  /* calculated crc */
466 
467 	struct timespec64 last_keepalive_ack; /* keepalive2 ack stamp */
468 
469 	struct delayed_work work;	    /* send|recv work */
470 	unsigned long       delay;          /* current delay interval */
471 
472 	union {
473 		struct ceph_connection_v1_info v1;
474 		struct ceph_connection_v2_info v2;
475 	};
476 };
477 
478 extern struct page *ceph_zero_page;
479 
480 void ceph_con_flag_clear(struct ceph_connection *con, unsigned long con_flag);
481 void ceph_con_flag_set(struct ceph_connection *con, unsigned long con_flag);
482 bool ceph_con_flag_test(struct ceph_connection *con, unsigned long con_flag);
483 bool ceph_con_flag_test_and_clear(struct ceph_connection *con,
484 				  unsigned long con_flag);
485 bool ceph_con_flag_test_and_set(struct ceph_connection *con,
486 				unsigned long con_flag);
487 
488 void ceph_encode_my_addr(struct ceph_messenger *msgr);
489 
490 int ceph_tcp_connect(struct ceph_connection *con);
491 int ceph_con_close_socket(struct ceph_connection *con);
492 void ceph_con_reset_session(struct ceph_connection *con);
493 
494 u32 ceph_get_global_seq(struct ceph_messenger *msgr, u32 gt);
495 void ceph_con_discard_sent(struct ceph_connection *con, u64 ack_seq);
496 void ceph_con_discard_requeued(struct ceph_connection *con, u64 reconnect_seq);
497 
498 void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor,
499 			       struct ceph_msg *msg, size_t length);
500 struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
501 				size_t *page_offset, size_t *length,
502 				bool *last_piece);
503 void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes);
504 
505 u32 ceph_crc32c_page(u32 crc, struct page *page, unsigned int page_offset,
506 		     unsigned int length);
507 
508 bool ceph_addr_is_blank(const struct ceph_entity_addr *addr);
509 int ceph_addr_port(const struct ceph_entity_addr *addr);
510 void ceph_addr_set_port(struct ceph_entity_addr *addr, int p);
511 
512 void ceph_con_process_message(struct ceph_connection *con);
513 int ceph_con_in_msg_alloc(struct ceph_connection *con,
514 			  struct ceph_msg_header *hdr, int *skip);
515 void ceph_con_get_out_msg(struct ceph_connection *con);
516 
517 /* messenger_v1.c */
518 int ceph_con_v1_try_read(struct ceph_connection *con);
519 int ceph_con_v1_try_write(struct ceph_connection *con);
520 void ceph_con_v1_revoke(struct ceph_connection *con);
521 void ceph_con_v1_revoke_incoming(struct ceph_connection *con);
522 bool ceph_con_v1_opened(struct ceph_connection *con);
523 void ceph_con_v1_reset_session(struct ceph_connection *con);
524 void ceph_con_v1_reset_protocol(struct ceph_connection *con);
525 
526 /* messenger_v2.c */
527 int ceph_con_v2_try_read(struct ceph_connection *con);
528 int ceph_con_v2_try_write(struct ceph_connection *con);
529 void ceph_con_v2_revoke(struct ceph_connection *con);
530 void ceph_con_v2_revoke_incoming(struct ceph_connection *con);
531 bool ceph_con_v2_opened(struct ceph_connection *con);
532 void ceph_con_v2_reset_session(struct ceph_connection *con);
533 void ceph_con_v2_reset_protocol(struct ceph_connection *con);
534 
535 
536 extern const char *ceph_pr_addr(const struct ceph_entity_addr *addr);
537 
538 extern int ceph_parse_ips(const char *c, const char *end,
539 			  struct ceph_entity_addr *addr,
540 			  int max_count, int *count, char delim);
541 
542 extern int ceph_msgr_init(void);
543 extern void ceph_msgr_exit(void);
544 extern void ceph_msgr_flush(void);
545 
546 extern void ceph_messenger_init(struct ceph_messenger *msgr,
547 				struct ceph_entity_addr *myaddr);
548 extern void ceph_messenger_fini(struct ceph_messenger *msgr);
549 extern void ceph_messenger_reset_nonce(struct ceph_messenger *msgr);
550 
551 extern void ceph_con_init(struct ceph_connection *con, void *private,
552 			const struct ceph_connection_operations *ops,
553 			struct ceph_messenger *msgr);
554 extern void ceph_con_open(struct ceph_connection *con,
555 			  __u8 entity_type, __u64 entity_num,
556 			  struct ceph_entity_addr *addr);
557 extern bool ceph_con_opened(struct ceph_connection *con);
558 extern void ceph_con_close(struct ceph_connection *con);
559 extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);
560 
561 extern void ceph_msg_revoke(struct ceph_msg *msg);
562 extern void ceph_msg_revoke_incoming(struct ceph_msg *msg);
563 
564 extern void ceph_con_keepalive(struct ceph_connection *con);
565 extern bool ceph_con_keepalive_expired(struct ceph_connection *con,
566 				       unsigned long interval);
567 
568 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
569 			     size_t length, size_t alignment, bool own_pages);
570 extern void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
571 				struct ceph_pagelist *pagelist);
572 #ifdef CONFIG_BLOCK
573 void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
574 			   u32 length);
575 #endif /* CONFIG_BLOCK */
576 void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
577 			     struct ceph_bvec_iter *bvec_pos);
578 
579 struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
580 			       gfp_t flags, bool can_fail);
581 extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
582 				     bool can_fail);
583 
584 extern struct ceph_msg *ceph_msg_get(struct ceph_msg *msg);
585 extern void ceph_msg_put(struct ceph_msg *msg);
586 
587 extern void ceph_msg_dump(struct ceph_msg *msg);
588 
589 #endif
590