xref: /openbmc/linux/net/ceph/messenger.c (revision 83268fa6)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3 
4 #include <linux/crc32c.h>
5 #include <linux/ctype.h>
6 #include <linux/highmem.h>
7 #include <linux/inet.h>
8 #include <linux/kthread.h>
9 #include <linux/net.h>
10 #include <linux/nsproxy.h>
11 #include <linux/sched/mm.h>
12 #include <linux/slab.h>
13 #include <linux/socket.h>
14 #include <linux/string.h>
15 #ifdef	CONFIG_BLOCK
16 #include <linux/bio.h>
17 #endif	/* CONFIG_BLOCK */
18 #include <linux/dns_resolver.h>
19 #include <net/tcp.h>
20 
21 #include <linux/ceph/ceph_features.h>
22 #include <linux/ceph/libceph.h>
23 #include <linux/ceph/messenger.h>
24 #include <linux/ceph/decode.h>
25 #include <linux/ceph/pagelist.h>
26 #include <linux/export.h>
27 
28 /*
29  * Ceph uses the messenger to exchange ceph_msg messages with other
30  * hosts in the system.  The messenger provides ordered and reliable
31  * delivery.  We tolerate TCP disconnects by reconnecting (with
32  * exponential backoff) in the case of a fault (disconnection, bad
33  * crc, protocol error).  Acks allow sent messages to be discarded by
34  * the sender.
35  */
36 
37 /*
38  * We track the state of the socket on a given connection using
39  * values defined below.  The transition to a new socket state is
40  * handled by a function which verifies we aren't coming from an
41  * unexpected state.
42  *
43  *      --------
44  *      | NEW* |  transient initial state
45  *      --------
46  *          | con_sock_state_init()
47  *          v
48  *      ----------
49  *      | CLOSED |  initialized, but no socket (and no
50  *      ----------  TCP connection)
51  *       ^      \
52  *       |       \ con_sock_state_connecting()
53  *       |        ----------------------
54  *       |                              \
55  *       + con_sock_state_closed()       \
56  *       |+---------------------------    \
57  *       | \                          \    \
58  *       |  -----------                \    \
59  *       |  | CLOSING |  socket event;  \    \
60  *       |  -----------  await close     \    \
61  *       |       ^                        \   |
62  *       |       |                         \  |
63  *       |       + con_sock_state_closing() \ |
64  *       |      / \                         | |
65  *       |     /   ---------------          | |
66  *       |    /                   \         v v
67  *       |   /                    --------------
68  *       |  /    -----------------| CONNECTING |  socket created, TCP
69  *       |  |   /                 --------------  connect initiated
70  *       |  |   | con_sock_state_connected()
71  *       |  |   v
72  *      -------------
73  *      | CONNECTED |  TCP connection established
74  *      -------------
75  *
76  * State values for ceph_connection->sock_state; NEW is assumed to be 0.
77  */
78 
79 #define CON_SOCK_STATE_NEW		0	/* -> CLOSED */
80 #define CON_SOCK_STATE_CLOSED		1	/* -> CONNECTING */
81 #define CON_SOCK_STATE_CONNECTING	2	/* -> CONNECTED or -> CLOSING */
82 #define CON_SOCK_STATE_CONNECTED	3	/* -> CLOSING or -> CLOSED */
83 #define CON_SOCK_STATE_CLOSING		4	/* -> CLOSED */
84 
85 /*
86  * connection states
87  */
88 #define CON_STATE_CLOSED        1  /* -> PREOPEN */
89 #define CON_STATE_PREOPEN       2  /* -> CONNECTING, CLOSED */
90 #define CON_STATE_CONNECTING    3  /* -> NEGOTIATING, CLOSED */
91 #define CON_STATE_NEGOTIATING   4  /* -> OPEN, CLOSED */
92 #define CON_STATE_OPEN          5  /* -> STANDBY, CLOSED */
93 #define CON_STATE_STANDBY       6  /* -> PREOPEN, CLOSED */
94 
95 /*
96  * ceph_connection flag bits
97  */
98 #define CON_FLAG_LOSSYTX           0  /* we can close channel or drop
99 				       * messages on errors */
100 #define CON_FLAG_KEEPALIVE_PENDING 1  /* we need to send a keepalive */
101 #define CON_FLAG_WRITE_PENDING	   2  /* we have data ready to send */
102 #define CON_FLAG_SOCK_CLOSED	   3  /* socket state changed to closed */
103 #define CON_FLAG_BACKOFF           4  /* need to retry queuing delayed work */
104 
105 static bool con_flag_valid(unsigned long con_flag)
106 {
107 	switch (con_flag) {
108 	case CON_FLAG_LOSSYTX:
109 	case CON_FLAG_KEEPALIVE_PENDING:
110 	case CON_FLAG_WRITE_PENDING:
111 	case CON_FLAG_SOCK_CLOSED:
112 	case CON_FLAG_BACKOFF:
113 		return true;
114 	default:
115 		return false;
116 	}
117 }
118 
119 static void con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
120 {
121 	BUG_ON(!con_flag_valid(con_flag));
122 
123 	clear_bit(con_flag, &con->flags);
124 }
125 
126 static void con_flag_set(struct ceph_connection *con, unsigned long con_flag)
127 {
128 	BUG_ON(!con_flag_valid(con_flag));
129 
130 	set_bit(con_flag, &con->flags);
131 }
132 
133 static bool con_flag_test(struct ceph_connection *con, unsigned long con_flag)
134 {
135 	BUG_ON(!con_flag_valid(con_flag));
136 
137 	return test_bit(con_flag, &con->flags);
138 }
139 
140 static bool con_flag_test_and_clear(struct ceph_connection *con,
141 					unsigned long con_flag)
142 {
143 	BUG_ON(!con_flag_valid(con_flag));
144 
145 	return test_and_clear_bit(con_flag, &con->flags);
146 }
147 
148 static bool con_flag_test_and_set(struct ceph_connection *con,
149 					unsigned long con_flag)
150 {
151 	BUG_ON(!con_flag_valid(con_flag));
152 
153 	return test_and_set_bit(con_flag, &con->flags);
154 }
155 
156 /* Slab caches for frequently-allocated structures */
157 
158 static struct kmem_cache	*ceph_msg_cache;
159 
160 /* static tag bytes (protocol control messages) */
161 static char tag_msg = CEPH_MSGR_TAG_MSG;
162 static char tag_ack = CEPH_MSGR_TAG_ACK;
163 static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
164 static char tag_keepalive2 = CEPH_MSGR_TAG_KEEPALIVE2;
165 
166 #ifdef CONFIG_LOCKDEP
167 static struct lock_class_key socket_class;
168 #endif
169 
170 static void queue_con(struct ceph_connection *con);
171 static void cancel_con(struct ceph_connection *con);
172 static void ceph_con_workfn(struct work_struct *);
173 static void con_fault(struct ceph_connection *con);
174 
175 /*
176  * Nicely render a sockaddr as a string.  An array of formatted
177  * strings is used, to approximate reentrancy.
178  */
179 #define ADDR_STR_COUNT_LOG	5	/* log2(# address strings in array) */
180 #define ADDR_STR_COUNT		(1 << ADDR_STR_COUNT_LOG)
181 #define ADDR_STR_COUNT_MASK	(ADDR_STR_COUNT - 1)
182 #define MAX_ADDR_STR_LEN	64	/* 54 is enough */
183 
184 static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN];
185 static atomic_t addr_str_seq = ATOMIC_INIT(0);
186 
187 static struct page *zero_page;		/* used in certain error cases */
188 
189 const char *ceph_pr_addr(const struct sockaddr_storage *ss)
190 {
191 	int i;
192 	char *s;
193 	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
194 	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
195 
196 	i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
197 	s = addr_str[i];
198 
199 	switch (ss->ss_family) {
200 	case AF_INET:
201 		snprintf(s, MAX_ADDR_STR_LEN, "%pI4:%hu", &in4->sin_addr,
202 			 ntohs(in4->sin_port));
203 		break;
204 
205 	case AF_INET6:
206 		snprintf(s, MAX_ADDR_STR_LEN, "[%pI6c]:%hu", &in6->sin6_addr,
207 			 ntohs(in6->sin6_port));
208 		break;
209 
210 	default:
211 		snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
212 			 ss->ss_family);
213 	}
214 
215 	return s;
216 }
217 EXPORT_SYMBOL(ceph_pr_addr);
218 
219 static void encode_my_addr(struct ceph_messenger *msgr)
220 {
221 	memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
222 	ceph_encode_addr(&msgr->my_enc_addr);
223 }
224 
225 /*
226  * work queue for all reading and writing to/from the socket.
227  */
228 static struct workqueue_struct *ceph_msgr_wq;
229 
230 static int ceph_msgr_slab_init(void)
231 {
232 	BUG_ON(ceph_msg_cache);
233 	ceph_msg_cache = KMEM_CACHE(ceph_msg, 0);
234 	if (!ceph_msg_cache)
235 		return -ENOMEM;
236 
237 	return 0;
238 }
239 
240 static void ceph_msgr_slab_exit(void)
241 {
242 	BUG_ON(!ceph_msg_cache);
243 	kmem_cache_destroy(ceph_msg_cache);
244 	ceph_msg_cache = NULL;
245 }
246 
247 static void _ceph_msgr_exit(void)
248 {
249 	if (ceph_msgr_wq) {
250 		destroy_workqueue(ceph_msgr_wq);
251 		ceph_msgr_wq = NULL;
252 	}
253 
254 	BUG_ON(zero_page == NULL);
255 	put_page(zero_page);
256 	zero_page = NULL;
257 
258 	ceph_msgr_slab_exit();
259 }
260 
261 int __init ceph_msgr_init(void)
262 {
263 	if (ceph_msgr_slab_init())
264 		return -ENOMEM;
265 
266 	BUG_ON(zero_page != NULL);
267 	zero_page = ZERO_PAGE(0);
268 	get_page(zero_page);
269 
270 	/*
271 	 * The number of active work items is limited by the number of
272 	 * connections, so leave @max_active at default.
273 	 */
274 	ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
275 	if (ceph_msgr_wq)
276 		return 0;
277 
278 	pr_err("msgr_init failed to create workqueue\n");
279 	_ceph_msgr_exit();
280 
281 	return -ENOMEM;
282 }
283 
284 void ceph_msgr_exit(void)
285 {
286 	BUG_ON(ceph_msgr_wq == NULL);
287 
288 	_ceph_msgr_exit();
289 }
290 
291 void ceph_msgr_flush(void)
292 {
293 	flush_workqueue(ceph_msgr_wq);
294 }
295 EXPORT_SYMBOL(ceph_msgr_flush);
296 
297 /* Connection socket state transition functions */
298 
299 static void con_sock_state_init(struct ceph_connection *con)
300 {
301 	int old_state;
302 
303 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
304 	if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
305 		printk("%s: unexpected old state %d\n", __func__, old_state);
306 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
307 	     CON_SOCK_STATE_CLOSED);
308 }
309 
310 static void con_sock_state_connecting(struct ceph_connection *con)
311 {
312 	int old_state;
313 
314 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
315 	if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
316 		printk("%s: unexpected old state %d\n", __func__, old_state);
317 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
318 	     CON_SOCK_STATE_CONNECTING);
319 }
320 
321 static void con_sock_state_connected(struct ceph_connection *con)
322 {
323 	int old_state;
324 
325 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
326 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
327 		printk("%s: unexpected old state %d\n", __func__, old_state);
328 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
329 	     CON_SOCK_STATE_CONNECTED);
330 }
331 
332 static void con_sock_state_closing(struct ceph_connection *con)
333 {
334 	int old_state;
335 
336 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
337 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
338 			old_state != CON_SOCK_STATE_CONNECTED &&
339 			old_state != CON_SOCK_STATE_CLOSING))
340 		printk("%s: unexpected old state %d\n", __func__, old_state);
341 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
342 	     CON_SOCK_STATE_CLOSING);
343 }
344 
345 static void con_sock_state_closed(struct ceph_connection *con)
346 {
347 	int old_state;
348 
349 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
350 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
351 		    old_state != CON_SOCK_STATE_CLOSING &&
352 		    old_state != CON_SOCK_STATE_CONNECTING &&
353 		    old_state != CON_SOCK_STATE_CLOSED))
354 		printk("%s: unexpected old state %d\n", __func__, old_state);
355 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
356 	     CON_SOCK_STATE_CLOSED);
357 }
358 
359 /*
360  * socket callback functions
361  */
362 
363 /* data available on socket, or listen socket received a connect */
364 static void ceph_sock_data_ready(struct sock *sk)
365 {
366 	struct ceph_connection *con = sk->sk_user_data;
367 	if (atomic_read(&con->msgr->stopping)) {
368 		return;
369 	}
370 
371 	if (sk->sk_state != TCP_CLOSE_WAIT) {
372 		dout("%s on %p state = %lu, queueing work\n", __func__,
373 		     con, con->state);
374 		queue_con(con);
375 	}
376 }
377 
378 /* socket has buffer space for writing */
379 static void ceph_sock_write_space(struct sock *sk)
380 {
381 	struct ceph_connection *con = sk->sk_user_data;
382 
383 	/* only queue to workqueue if there is data we want to write,
384 	 * and there is sufficient space in the socket buffer to accept
385 	 * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
386 	 * doesn't get called again until try_write() fills the socket
387 	 * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
388 	 * and net/core/stream.c:sk_stream_write_space().
389 	 */
390 	if (con_flag_test(con, CON_FLAG_WRITE_PENDING)) {
391 		if (sk_stream_is_writeable(sk)) {
392 			dout("%s %p queueing write work\n", __func__, con);
393 			clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
394 			queue_con(con);
395 		}
396 	} else {
397 		dout("%s %p nothing to write\n", __func__, con);
398 	}
399 }
400 
401 /* socket's state has changed */
402 static void ceph_sock_state_change(struct sock *sk)
403 {
404 	struct ceph_connection *con = sk->sk_user_data;
405 
406 	dout("%s %p state = %lu sk_state = %u\n", __func__,
407 	     con, con->state, sk->sk_state);
408 
409 	switch (sk->sk_state) {
410 	case TCP_CLOSE:
411 		dout("%s TCP_CLOSE\n", __func__);
412 		/* fall through */
413 	case TCP_CLOSE_WAIT:
414 		dout("%s TCP_CLOSE_WAIT\n", __func__);
415 		con_sock_state_closing(con);
416 		con_flag_set(con, CON_FLAG_SOCK_CLOSED);
417 		queue_con(con);
418 		break;
419 	case TCP_ESTABLISHED:
420 		dout("%s TCP_ESTABLISHED\n", __func__);
421 		con_sock_state_connected(con);
422 		queue_con(con);
423 		break;
424 	default:	/* Everything else is uninteresting */
425 		break;
426 	}
427 }
428 
429 /*
430  * set up socket callbacks
431  */
432 static void set_sock_callbacks(struct socket *sock,
433 			       struct ceph_connection *con)
434 {
435 	struct sock *sk = sock->sk;
436 	sk->sk_user_data = con;
437 	sk->sk_data_ready = ceph_sock_data_ready;
438 	sk->sk_write_space = ceph_sock_write_space;
439 	sk->sk_state_change = ceph_sock_state_change;
440 }
441 
442 
443 /*
444  * socket helpers
445  */
446 
447 /*
448  * initiate connection to a remote socket.
449  */
450 static int ceph_tcp_connect(struct ceph_connection *con)
451 {
452 	struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
453 	struct socket *sock;
454 	unsigned int noio_flag;
455 	int ret;
456 
457 	BUG_ON(con->sock);
458 
459 	/* sock_create_kern() allocates with GFP_KERNEL */
460 	noio_flag = memalloc_noio_save();
461 	ret = sock_create_kern(read_pnet(&con->msgr->net), paddr->ss_family,
462 			       SOCK_STREAM, IPPROTO_TCP, &sock);
463 	memalloc_noio_restore(noio_flag);
464 	if (ret)
465 		return ret;
466 	sock->sk->sk_allocation = GFP_NOFS;
467 
468 #ifdef CONFIG_LOCKDEP
469 	lockdep_set_class(&sock->sk->sk_lock, &socket_class);
470 #endif
471 
472 	set_sock_callbacks(sock, con);
473 
474 	dout("connect %s\n", ceph_pr_addr(&con->peer_addr.in_addr));
475 
476 	con_sock_state_connecting(con);
477 	ret = sock->ops->connect(sock, (struct sockaddr *)paddr, sizeof(*paddr),
478 				 O_NONBLOCK);
479 	if (ret == -EINPROGRESS) {
480 		dout("connect %s EINPROGRESS sk_state = %u\n",
481 		     ceph_pr_addr(&con->peer_addr.in_addr),
482 		     sock->sk->sk_state);
483 	} else if (ret < 0) {
484 		pr_err("connect %s error %d\n",
485 		       ceph_pr_addr(&con->peer_addr.in_addr), ret);
486 		sock_release(sock);
487 		return ret;
488 	}
489 
490 	if (ceph_test_opt(from_msgr(con->msgr), TCP_NODELAY)) {
491 		int optval = 1;
492 
493 		ret = kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
494 					(char *)&optval, sizeof(optval));
495 		if (ret)
496 			pr_err("kernel_setsockopt(TCP_NODELAY) failed: %d",
497 			       ret);
498 	}
499 
500 	con->sock = sock;
501 	return 0;
502 }
503 
504 /*
505  * If @buf is NULL, discard up to @len bytes.
506  */
507 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
508 {
509 	struct kvec iov = {buf, len};
510 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
511 	int r;
512 
513 	if (!buf)
514 		msg.msg_flags |= MSG_TRUNC;
515 
516 	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, len);
517 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
518 	if (r == -EAGAIN)
519 		r = 0;
520 	return r;
521 }
522 
523 static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
524 		     int page_offset, size_t length)
525 {
526 	struct bio_vec bvec = {
527 		.bv_page = page,
528 		.bv_offset = page_offset,
529 		.bv_len = length
530 	};
531 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
532 	int r;
533 
534 	BUG_ON(page_offset + length > PAGE_SIZE);
535 	iov_iter_bvec(&msg.msg_iter, READ, &bvec, 1, length);
536 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
537 	if (r == -EAGAIN)
538 		r = 0;
539 	return r;
540 }
541 
542 /*
543  * write something.  @more is true if caller will be sending more data
544  * shortly.
545  */
546 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
547 		     size_t kvlen, size_t len, int more)
548 {
549 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
550 	int r;
551 
552 	if (more)
553 		msg.msg_flags |= MSG_MORE;
554 	else
555 		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
556 
557 	r = kernel_sendmsg(sock, &msg, iov, kvlen, len);
558 	if (r == -EAGAIN)
559 		r = 0;
560 	return r;
561 }
562 
563 static int __ceph_tcp_sendpage(struct socket *sock, struct page *page,
564 		     int offset, size_t size, bool more)
565 {
566 	int flags = MSG_DONTWAIT | MSG_NOSIGNAL | (more ? MSG_MORE : MSG_EOR);
567 	int ret;
568 
569 	ret = kernel_sendpage(sock, page, offset, size, flags);
570 	if (ret == -EAGAIN)
571 		ret = 0;
572 
573 	return ret;
574 }
575 
576 static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
577 		     int offset, size_t size, bool more)
578 {
579 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
580 	struct bio_vec bvec;
581 	int ret;
582 
583 	/* sendpage cannot properly handle pages with page_count == 0,
584 	 * we need to fallback to sendmsg if that's the case */
585 	if (page_count(page) >= 1)
586 		return __ceph_tcp_sendpage(sock, page, offset, size, more);
587 
588 	bvec.bv_page = page;
589 	bvec.bv_offset = offset;
590 	bvec.bv_len = size;
591 
592 	if (more)
593 		msg.msg_flags |= MSG_MORE;
594 	else
595 		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
596 
597 	iov_iter_bvec(&msg.msg_iter, WRITE, &bvec, 1, size);
598 	ret = sock_sendmsg(sock, &msg);
599 	if (ret == -EAGAIN)
600 		ret = 0;
601 
602 	return ret;
603 }
604 
605 /*
606  * Shutdown/close the socket for the given connection.
607  */
608 static int con_close_socket(struct ceph_connection *con)
609 {
610 	int rc = 0;
611 
612 	dout("con_close_socket on %p sock %p\n", con, con->sock);
613 	if (con->sock) {
614 		rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
615 		sock_release(con->sock);
616 		con->sock = NULL;
617 	}
618 
619 	/*
620 	 * Forcibly clear the SOCK_CLOSED flag.  It gets set
621 	 * independent of the connection mutex, and we could have
622 	 * received a socket close event before we had the chance to
623 	 * shut the socket down.
624 	 */
625 	con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
626 
627 	con_sock_state_closed(con);
628 	return rc;
629 }
630 
631 /*
632  * Reset a connection.  Discard all incoming and outgoing messages
633  * and clear *_seq state.
634  */
635 static void ceph_msg_remove(struct ceph_msg *msg)
636 {
637 	list_del_init(&msg->list_head);
638 
639 	ceph_msg_put(msg);
640 }
641 static void ceph_msg_remove_list(struct list_head *head)
642 {
643 	while (!list_empty(head)) {
644 		struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
645 							list_head);
646 		ceph_msg_remove(msg);
647 	}
648 }
649 
650 static void reset_connection(struct ceph_connection *con)
651 {
652 	/* reset connection, out_queue, msg_ and connect_seq */
653 	/* discard existing out_queue and msg_seq */
654 	dout("reset_connection %p\n", con);
655 	ceph_msg_remove_list(&con->out_queue);
656 	ceph_msg_remove_list(&con->out_sent);
657 
658 	if (con->in_msg) {
659 		BUG_ON(con->in_msg->con != con);
660 		ceph_msg_put(con->in_msg);
661 		con->in_msg = NULL;
662 	}
663 
664 	con->connect_seq = 0;
665 	con->out_seq = 0;
666 	if (con->out_msg) {
667 		BUG_ON(con->out_msg->con != con);
668 		ceph_msg_put(con->out_msg);
669 		con->out_msg = NULL;
670 	}
671 	con->in_seq = 0;
672 	con->in_seq_acked = 0;
673 
674 	con->out_skip = 0;
675 }
676 
677 /*
678  * mark a peer down.  drop any open connections.
679  */
680 void ceph_con_close(struct ceph_connection *con)
681 {
682 	mutex_lock(&con->mutex);
683 	dout("con_close %p peer %s\n", con,
684 	     ceph_pr_addr(&con->peer_addr.in_addr));
685 	con->state = CON_STATE_CLOSED;
686 
687 	con_flag_clear(con, CON_FLAG_LOSSYTX);	/* so we retry next connect */
688 	con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
689 	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
690 	con_flag_clear(con, CON_FLAG_BACKOFF);
691 
692 	reset_connection(con);
693 	con->peer_global_seq = 0;
694 	cancel_con(con);
695 	con_close_socket(con);
696 	mutex_unlock(&con->mutex);
697 }
698 EXPORT_SYMBOL(ceph_con_close);
699 
700 /*
701  * Reopen a closed connection, with a new peer address.
702  */
703 void ceph_con_open(struct ceph_connection *con,
704 		   __u8 entity_type, __u64 entity_num,
705 		   struct ceph_entity_addr *addr)
706 {
707 	mutex_lock(&con->mutex);
708 	dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
709 
710 	WARN_ON(con->state != CON_STATE_CLOSED);
711 	con->state = CON_STATE_PREOPEN;
712 
713 	con->peer_name.type = (__u8) entity_type;
714 	con->peer_name.num = cpu_to_le64(entity_num);
715 
716 	memcpy(&con->peer_addr, addr, sizeof(*addr));
717 	con->delay = 0;      /* reset backoff memory */
718 	mutex_unlock(&con->mutex);
719 	queue_con(con);
720 }
721 EXPORT_SYMBOL(ceph_con_open);
722 
723 /*
724  * return true if this connection ever successfully opened
725  */
726 bool ceph_con_opened(struct ceph_connection *con)
727 {
728 	return con->connect_seq > 0;
729 }
730 
731 /*
732  * initialize a new connection.
733  */
734 void ceph_con_init(struct ceph_connection *con, void *private,
735 	const struct ceph_connection_operations *ops,
736 	struct ceph_messenger *msgr)
737 {
738 	dout("con_init %p\n", con);
739 	memset(con, 0, sizeof(*con));
740 	con->private = private;
741 	con->ops = ops;
742 	con->msgr = msgr;
743 
744 	con_sock_state_init(con);
745 
746 	mutex_init(&con->mutex);
747 	INIT_LIST_HEAD(&con->out_queue);
748 	INIT_LIST_HEAD(&con->out_sent);
749 	INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
750 
751 	con->state = CON_STATE_CLOSED;
752 }
753 EXPORT_SYMBOL(ceph_con_init);
754 
755 
756 /*
757  * We maintain a global counter to order connection attempts.  Get
758  * a unique seq greater than @gt.
759  */
760 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
761 {
762 	u32 ret;
763 
764 	spin_lock(&msgr->global_seq_lock);
765 	if (msgr->global_seq < gt)
766 		msgr->global_seq = gt;
767 	ret = ++msgr->global_seq;
768 	spin_unlock(&msgr->global_seq_lock);
769 	return ret;
770 }
771 
772 static void con_out_kvec_reset(struct ceph_connection *con)
773 {
774 	BUG_ON(con->out_skip);
775 
776 	con->out_kvec_left = 0;
777 	con->out_kvec_bytes = 0;
778 	con->out_kvec_cur = &con->out_kvec[0];
779 }
780 
781 static void con_out_kvec_add(struct ceph_connection *con,
782 				size_t size, void *data)
783 {
784 	int index = con->out_kvec_left;
785 
786 	BUG_ON(con->out_skip);
787 	BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
788 
789 	con->out_kvec[index].iov_len = size;
790 	con->out_kvec[index].iov_base = data;
791 	con->out_kvec_left++;
792 	con->out_kvec_bytes += size;
793 }
794 
795 /*
796  * Chop off a kvec from the end.  Return residual number of bytes for
797  * that kvec, i.e. how many bytes would have been written if the kvec
798  * hadn't been nuked.
799  */
800 static int con_out_kvec_skip(struct ceph_connection *con)
801 {
802 	int off = con->out_kvec_cur - con->out_kvec;
803 	int skip = 0;
804 
805 	if (con->out_kvec_bytes > 0) {
806 		skip = con->out_kvec[off + con->out_kvec_left - 1].iov_len;
807 		BUG_ON(con->out_kvec_bytes < skip);
808 		BUG_ON(!con->out_kvec_left);
809 		con->out_kvec_bytes -= skip;
810 		con->out_kvec_left--;
811 	}
812 
813 	return skip;
814 }
815 
816 #ifdef CONFIG_BLOCK
817 
818 /*
819  * For a bio data item, a piece is whatever remains of the next
820  * entry in the current bio iovec, or the first entry in the next
821  * bio in the list.
822  */
823 static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
824 					size_t length)
825 {
826 	struct ceph_msg_data *data = cursor->data;
827 	struct ceph_bio_iter *it = &cursor->bio_iter;
828 
829 	cursor->resid = min_t(size_t, length, data->bio_length);
830 	*it = data->bio_pos;
831 	if (cursor->resid < it->iter.bi_size)
832 		it->iter.bi_size = cursor->resid;
833 
834 	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
835 	cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
836 }
837 
838 static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
839 						size_t *page_offset,
840 						size_t *length)
841 {
842 	struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
843 					   cursor->bio_iter.iter);
844 
845 	*page_offset = bv.bv_offset;
846 	*length = bv.bv_len;
847 	return bv.bv_page;
848 }
849 
850 static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
851 					size_t bytes)
852 {
853 	struct ceph_bio_iter *it = &cursor->bio_iter;
854 
855 	BUG_ON(bytes > cursor->resid);
856 	BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
857 	cursor->resid -= bytes;
858 	bio_advance_iter(it->bio, &it->iter, bytes);
859 
860 	if (!cursor->resid) {
861 		BUG_ON(!cursor->last_piece);
862 		return false;   /* no more data */
863 	}
864 
865 	if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done))
866 		return false;	/* more bytes to process in this segment */
867 
868 	if (!it->iter.bi_size) {
869 		it->bio = it->bio->bi_next;
870 		it->iter = it->bio->bi_iter;
871 		if (cursor->resid < it->iter.bi_size)
872 			it->iter.bi_size = cursor->resid;
873 	}
874 
875 	BUG_ON(cursor->last_piece);
876 	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
877 	cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
878 	return true;
879 }
880 #endif /* CONFIG_BLOCK */
881 
882 static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
883 					size_t length)
884 {
885 	struct ceph_msg_data *data = cursor->data;
886 	struct bio_vec *bvecs = data->bvec_pos.bvecs;
887 
888 	cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
889 	cursor->bvec_iter = data->bvec_pos.iter;
890 	cursor->bvec_iter.bi_size = cursor->resid;
891 
892 	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
893 	cursor->last_piece =
894 	    cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
895 }
896 
897 static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
898 						size_t *page_offset,
899 						size_t *length)
900 {
901 	struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
902 					   cursor->bvec_iter);
903 
904 	*page_offset = bv.bv_offset;
905 	*length = bv.bv_len;
906 	return bv.bv_page;
907 }
908 
909 static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
910 					size_t bytes)
911 {
912 	struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
913 
914 	BUG_ON(bytes > cursor->resid);
915 	BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
916 	cursor->resid -= bytes;
917 	bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
918 
919 	if (!cursor->resid) {
920 		BUG_ON(!cursor->last_piece);
921 		return false;   /* no more data */
922 	}
923 
924 	if (!bytes || cursor->bvec_iter.bi_bvec_done)
925 		return false;	/* more bytes to process in this segment */
926 
927 	BUG_ON(cursor->last_piece);
928 	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
929 	cursor->last_piece =
930 	    cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
931 	return true;
932 }
933 
934 /*
935  * For a page array, a piece comes from the first page in the array
936  * that has not already been fully consumed.
937  */
938 static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
939 					size_t length)
940 {
941 	struct ceph_msg_data *data = cursor->data;
942 	int page_count;
943 
944 	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
945 
946 	BUG_ON(!data->pages);
947 	BUG_ON(!data->length);
948 
949 	cursor->resid = min(length, data->length);
950 	page_count = calc_pages_for(data->alignment, (u64)data->length);
951 	cursor->page_offset = data->alignment & ~PAGE_MASK;
952 	cursor->page_index = 0;
953 	BUG_ON(page_count > (int)USHRT_MAX);
954 	cursor->page_count = (unsigned short)page_count;
955 	BUG_ON(length > SIZE_MAX - cursor->page_offset);
956 	cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
957 }
958 
959 static struct page *
960 ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
961 					size_t *page_offset, size_t *length)
962 {
963 	struct ceph_msg_data *data = cursor->data;
964 
965 	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
966 
967 	BUG_ON(cursor->page_index >= cursor->page_count);
968 	BUG_ON(cursor->page_offset >= PAGE_SIZE);
969 
970 	*page_offset = cursor->page_offset;
971 	if (cursor->last_piece)
972 		*length = cursor->resid;
973 	else
974 		*length = PAGE_SIZE - *page_offset;
975 
976 	return data->pages[cursor->page_index];
977 }
978 
979 static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
980 						size_t bytes)
981 {
982 	BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
983 
984 	BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
985 
986 	/* Advance the cursor page offset */
987 
988 	cursor->resid -= bytes;
989 	cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
990 	if (!bytes || cursor->page_offset)
991 		return false;	/* more bytes to process in the current page */
992 
993 	if (!cursor->resid)
994 		return false;   /* no more data */
995 
996 	/* Move on to the next page; offset is already at 0 */
997 
998 	BUG_ON(cursor->page_index >= cursor->page_count);
999 	cursor->page_index++;
1000 	cursor->last_piece = cursor->resid <= PAGE_SIZE;
1001 
1002 	return true;
1003 }
1004 
1005 /*
1006  * For a pagelist, a piece is whatever remains to be consumed in the
1007  * first page in the list, or the front of the next page.
1008  */
1009 static void
1010 ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
1011 					size_t length)
1012 {
1013 	struct ceph_msg_data *data = cursor->data;
1014 	struct ceph_pagelist *pagelist;
1015 	struct page *page;
1016 
1017 	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1018 
1019 	pagelist = data->pagelist;
1020 	BUG_ON(!pagelist);
1021 
1022 	if (!length)
1023 		return;		/* pagelist can be assigned but empty */
1024 
1025 	BUG_ON(list_empty(&pagelist->head));
1026 	page = list_first_entry(&pagelist->head, struct page, lru);
1027 
1028 	cursor->resid = min(length, pagelist->length);
1029 	cursor->page = page;
1030 	cursor->offset = 0;
1031 	cursor->last_piece = cursor->resid <= PAGE_SIZE;
1032 }
1033 
1034 static struct page *
1035 ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
1036 				size_t *page_offset, size_t *length)
1037 {
1038 	struct ceph_msg_data *data = cursor->data;
1039 	struct ceph_pagelist *pagelist;
1040 
1041 	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1042 
1043 	pagelist = data->pagelist;
1044 	BUG_ON(!pagelist);
1045 
1046 	BUG_ON(!cursor->page);
1047 	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1048 
1049 	/* offset of first page in pagelist is always 0 */
1050 	*page_offset = cursor->offset & ~PAGE_MASK;
1051 	if (cursor->last_piece)
1052 		*length = cursor->resid;
1053 	else
1054 		*length = PAGE_SIZE - *page_offset;
1055 
1056 	return cursor->page;
1057 }
1058 
1059 static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
1060 						size_t bytes)
1061 {
1062 	struct ceph_msg_data *data = cursor->data;
1063 	struct ceph_pagelist *pagelist;
1064 
1065 	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1066 
1067 	pagelist = data->pagelist;
1068 	BUG_ON(!pagelist);
1069 
1070 	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1071 	BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
1072 
1073 	/* Advance the cursor offset */
1074 
1075 	cursor->resid -= bytes;
1076 	cursor->offset += bytes;
1077 	/* offset of first page in pagelist is always 0 */
1078 	if (!bytes || cursor->offset & ~PAGE_MASK)
1079 		return false;	/* more bytes to process in the current page */
1080 
1081 	if (!cursor->resid)
1082 		return false;   /* no more data */
1083 
1084 	/* Move on to the next page */
1085 
1086 	BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
1087 	cursor->page = list_next_entry(cursor->page, lru);
1088 	cursor->last_piece = cursor->resid <= PAGE_SIZE;
1089 
1090 	return true;
1091 }
1092 
1093 /*
1094  * Message data is handled (sent or received) in pieces, where each
1095  * piece resides on a single page.  The network layer might not
1096  * consume an entire piece at once.  A data item's cursor keeps
1097  * track of which piece is next to process and how much remains to
1098  * be processed in that piece.  It also tracks whether the current
1099  * piece is the last one in the data item.
1100  */
1101 static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
1102 {
1103 	size_t length = cursor->total_resid;
1104 
1105 	switch (cursor->data->type) {
1106 	case CEPH_MSG_DATA_PAGELIST:
1107 		ceph_msg_data_pagelist_cursor_init(cursor, length);
1108 		break;
1109 	case CEPH_MSG_DATA_PAGES:
1110 		ceph_msg_data_pages_cursor_init(cursor, length);
1111 		break;
1112 #ifdef CONFIG_BLOCK
1113 	case CEPH_MSG_DATA_BIO:
1114 		ceph_msg_data_bio_cursor_init(cursor, length);
1115 		break;
1116 #endif /* CONFIG_BLOCK */
1117 	case CEPH_MSG_DATA_BVECS:
1118 		ceph_msg_data_bvecs_cursor_init(cursor, length);
1119 		break;
1120 	case CEPH_MSG_DATA_NONE:
1121 	default:
1122 		/* BUG(); */
1123 		break;
1124 	}
1125 	cursor->need_crc = true;
1126 }
1127 
1128 static void ceph_msg_data_cursor_init(struct ceph_msg *msg, size_t length)
1129 {
1130 	struct ceph_msg_data_cursor *cursor = &msg->cursor;
1131 
1132 	BUG_ON(!length);
1133 	BUG_ON(length > msg->data_length);
1134 	BUG_ON(!msg->num_data_items);
1135 
1136 	cursor->total_resid = length;
1137 	cursor->data = msg->data;
1138 
1139 	__ceph_msg_data_cursor_init(cursor);
1140 }
1141 
1142 /*
1143  * Return the page containing the next piece to process for a given
1144  * data item, and supply the page offset and length of that piece.
1145  * Indicate whether this is the last piece in this data item.
1146  */
1147 static struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
1148 					size_t *page_offset, size_t *length,
1149 					bool *last_piece)
1150 {
1151 	struct page *page;
1152 
1153 	switch (cursor->data->type) {
1154 	case CEPH_MSG_DATA_PAGELIST:
1155 		page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
1156 		break;
1157 	case CEPH_MSG_DATA_PAGES:
1158 		page = ceph_msg_data_pages_next(cursor, page_offset, length);
1159 		break;
1160 #ifdef CONFIG_BLOCK
1161 	case CEPH_MSG_DATA_BIO:
1162 		page = ceph_msg_data_bio_next(cursor, page_offset, length);
1163 		break;
1164 #endif /* CONFIG_BLOCK */
1165 	case CEPH_MSG_DATA_BVECS:
1166 		page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
1167 		break;
1168 	case CEPH_MSG_DATA_NONE:
1169 	default:
1170 		page = NULL;
1171 		break;
1172 	}
1173 
1174 	BUG_ON(!page);
1175 	BUG_ON(*page_offset + *length > PAGE_SIZE);
1176 	BUG_ON(!*length);
1177 	BUG_ON(*length > cursor->resid);
1178 	if (last_piece)
1179 		*last_piece = cursor->last_piece;
1180 
1181 	return page;
1182 }
1183 
1184 /*
1185  * Returns true if the result moves the cursor on to the next piece
1186  * of the data item.
1187  */
1188 static void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor,
1189 				  size_t bytes)
1190 {
1191 	bool new_piece;
1192 
1193 	BUG_ON(bytes > cursor->resid);
1194 	switch (cursor->data->type) {
1195 	case CEPH_MSG_DATA_PAGELIST:
1196 		new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
1197 		break;
1198 	case CEPH_MSG_DATA_PAGES:
1199 		new_piece = ceph_msg_data_pages_advance(cursor, bytes);
1200 		break;
1201 #ifdef CONFIG_BLOCK
1202 	case CEPH_MSG_DATA_BIO:
1203 		new_piece = ceph_msg_data_bio_advance(cursor, bytes);
1204 		break;
1205 #endif /* CONFIG_BLOCK */
1206 	case CEPH_MSG_DATA_BVECS:
1207 		new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
1208 		break;
1209 	case CEPH_MSG_DATA_NONE:
1210 	default:
1211 		BUG();
1212 		break;
1213 	}
1214 	cursor->total_resid -= bytes;
1215 
1216 	if (!cursor->resid && cursor->total_resid) {
1217 		WARN_ON(!cursor->last_piece);
1218 		cursor->data++;
1219 		__ceph_msg_data_cursor_init(cursor);
1220 		new_piece = true;
1221 	}
1222 	cursor->need_crc = new_piece;
1223 }
1224 
1225 static size_t sizeof_footer(struct ceph_connection *con)
1226 {
1227 	return (con->peer_features & CEPH_FEATURE_MSG_AUTH) ?
1228 	    sizeof(struct ceph_msg_footer) :
1229 	    sizeof(struct ceph_msg_footer_old);
1230 }
1231 
1232 static void prepare_message_data(struct ceph_msg *msg, u32 data_len)
1233 {
1234 	/* Initialize data cursor */
1235 
1236 	ceph_msg_data_cursor_init(msg, (size_t)data_len);
1237 }
1238 
1239 /*
1240  * Prepare footer for currently outgoing message, and finish things
1241  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
1242  */
1243 static void prepare_write_message_footer(struct ceph_connection *con)
1244 {
1245 	struct ceph_msg *m = con->out_msg;
1246 
1247 	m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
1248 
1249 	dout("prepare_write_message_footer %p\n", con);
1250 	con_out_kvec_add(con, sizeof_footer(con), &m->footer);
1251 	if (con->peer_features & CEPH_FEATURE_MSG_AUTH) {
1252 		if (con->ops->sign_message)
1253 			con->ops->sign_message(m);
1254 		else
1255 			m->footer.sig = 0;
1256 	} else {
1257 		m->old_footer.flags = m->footer.flags;
1258 	}
1259 	con->out_more = m->more_to_follow;
1260 	con->out_msg_done = true;
1261 }
1262 
1263 /*
1264  * Prepare headers for the next outgoing message.
1265  */
1266 static void prepare_write_message(struct ceph_connection *con)
1267 {
1268 	struct ceph_msg *m;
1269 	u32 crc;
1270 
1271 	con_out_kvec_reset(con);
1272 	con->out_msg_done = false;
1273 
1274 	/* Sneak an ack in there first?  If we can get it into the same
1275 	 * TCP packet that's a good thing. */
1276 	if (con->in_seq > con->in_seq_acked) {
1277 		con->in_seq_acked = con->in_seq;
1278 		con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1279 		con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1280 		con_out_kvec_add(con, sizeof (con->out_temp_ack),
1281 			&con->out_temp_ack);
1282 	}
1283 
1284 	BUG_ON(list_empty(&con->out_queue));
1285 	m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
1286 	con->out_msg = m;
1287 	BUG_ON(m->con != con);
1288 
1289 	/* put message on sent list */
1290 	ceph_msg_get(m);
1291 	list_move_tail(&m->list_head, &con->out_sent);
1292 
1293 	/*
1294 	 * only assign outgoing seq # if we haven't sent this message
1295 	 * yet.  if it is requeued, resend with it's original seq.
1296 	 */
1297 	if (m->needs_out_seq) {
1298 		m->hdr.seq = cpu_to_le64(++con->out_seq);
1299 		m->needs_out_seq = false;
1300 
1301 		if (con->ops->reencode_message)
1302 			con->ops->reencode_message(m);
1303 	}
1304 
1305 	dout("prepare_write_message %p seq %lld type %d len %d+%d+%zd\n",
1306 	     m, con->out_seq, le16_to_cpu(m->hdr.type),
1307 	     le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
1308 	     m->data_length);
1309 	WARN_ON(m->front.iov_len != le32_to_cpu(m->hdr.front_len));
1310 	WARN_ON(m->data_length != le32_to_cpu(m->hdr.data_len));
1311 
1312 	/* tag + hdr + front + middle */
1313 	con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
1314 	con_out_kvec_add(con, sizeof(con->out_hdr), &con->out_hdr);
1315 	con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
1316 
1317 	if (m->middle)
1318 		con_out_kvec_add(con, m->middle->vec.iov_len,
1319 			m->middle->vec.iov_base);
1320 
1321 	/* fill in hdr crc and finalize hdr */
1322 	crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
1323 	con->out_msg->hdr.crc = cpu_to_le32(crc);
1324 	memcpy(&con->out_hdr, &con->out_msg->hdr, sizeof(con->out_hdr));
1325 
1326 	/* fill in front and middle crc, footer */
1327 	crc = crc32c(0, m->front.iov_base, m->front.iov_len);
1328 	con->out_msg->footer.front_crc = cpu_to_le32(crc);
1329 	if (m->middle) {
1330 		crc = crc32c(0, m->middle->vec.iov_base,
1331 				m->middle->vec.iov_len);
1332 		con->out_msg->footer.middle_crc = cpu_to_le32(crc);
1333 	} else
1334 		con->out_msg->footer.middle_crc = 0;
1335 	dout("%s front_crc %u middle_crc %u\n", __func__,
1336 	     le32_to_cpu(con->out_msg->footer.front_crc),
1337 	     le32_to_cpu(con->out_msg->footer.middle_crc));
1338 	con->out_msg->footer.flags = 0;
1339 
1340 	/* is there a data payload? */
1341 	con->out_msg->footer.data_crc = 0;
1342 	if (m->data_length) {
1343 		prepare_message_data(con->out_msg, m->data_length);
1344 		con->out_more = 1;  /* data + footer will follow */
1345 	} else {
1346 		/* no, queue up footer too and be done */
1347 		prepare_write_message_footer(con);
1348 	}
1349 
1350 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1351 }
1352 
1353 /*
1354  * Prepare an ack.
1355  */
1356 static void prepare_write_ack(struct ceph_connection *con)
1357 {
1358 	dout("prepare_write_ack %p %llu -> %llu\n", con,
1359 	     con->in_seq_acked, con->in_seq);
1360 	con->in_seq_acked = con->in_seq;
1361 
1362 	con_out_kvec_reset(con);
1363 
1364 	con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1365 
1366 	con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1367 	con_out_kvec_add(con, sizeof (con->out_temp_ack),
1368 				&con->out_temp_ack);
1369 
1370 	con->out_more = 1;  /* more will follow.. eventually.. */
1371 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1372 }
1373 
1374 /*
1375  * Prepare to share the seq during handshake
1376  */
1377 static void prepare_write_seq(struct ceph_connection *con)
1378 {
1379 	dout("prepare_write_seq %p %llu -> %llu\n", con,
1380 	     con->in_seq_acked, con->in_seq);
1381 	con->in_seq_acked = con->in_seq;
1382 
1383 	con_out_kvec_reset(con);
1384 
1385 	con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1386 	con_out_kvec_add(con, sizeof (con->out_temp_ack),
1387 			 &con->out_temp_ack);
1388 
1389 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1390 }
1391 
1392 /*
1393  * Prepare to write keepalive byte.
1394  */
1395 static void prepare_write_keepalive(struct ceph_connection *con)
1396 {
1397 	dout("prepare_write_keepalive %p\n", con);
1398 	con_out_kvec_reset(con);
1399 	if (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2) {
1400 		struct timespec64 now;
1401 
1402 		ktime_get_real_ts64(&now);
1403 		con_out_kvec_add(con, sizeof(tag_keepalive2), &tag_keepalive2);
1404 		ceph_encode_timespec64(&con->out_temp_keepalive2, &now);
1405 		con_out_kvec_add(con, sizeof(con->out_temp_keepalive2),
1406 				 &con->out_temp_keepalive2);
1407 	} else {
1408 		con_out_kvec_add(con, sizeof(tag_keepalive), &tag_keepalive);
1409 	}
1410 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1411 }
1412 
1413 /*
1414  * Connection negotiation.
1415  */
1416 
1417 static int get_connect_authorizer(struct ceph_connection *con)
1418 {
1419 	struct ceph_auth_handshake *auth;
1420 	int auth_proto;
1421 
1422 	if (!con->ops->get_authorizer) {
1423 		con->auth = NULL;
1424 		con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
1425 		con->out_connect.authorizer_len = 0;
1426 		return 0;
1427 	}
1428 
1429 	auth = con->ops->get_authorizer(con, &auth_proto, con->auth_retry);
1430 	if (IS_ERR(auth))
1431 		return PTR_ERR(auth);
1432 
1433 	con->auth = auth;
1434 	con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
1435 	con->out_connect.authorizer_len = cpu_to_le32(auth->authorizer_buf_len);
1436 	return 0;
1437 }
1438 
1439 /*
1440  * We connected to a peer and are saying hello.
1441  */
1442 static void prepare_write_banner(struct ceph_connection *con)
1443 {
1444 	con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
1445 	con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
1446 					&con->msgr->my_enc_addr);
1447 
1448 	con->out_more = 0;
1449 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1450 }
1451 
1452 static void __prepare_write_connect(struct ceph_connection *con)
1453 {
1454 	con_out_kvec_add(con, sizeof(con->out_connect), &con->out_connect);
1455 	if (con->auth)
1456 		con_out_kvec_add(con, con->auth->authorizer_buf_len,
1457 				 con->auth->authorizer_buf);
1458 
1459 	con->out_more = 0;
1460 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
1461 }
1462 
1463 static int prepare_write_connect(struct ceph_connection *con)
1464 {
1465 	unsigned int global_seq = get_global_seq(con->msgr, 0);
1466 	int proto;
1467 	int ret;
1468 
1469 	switch (con->peer_name.type) {
1470 	case CEPH_ENTITY_TYPE_MON:
1471 		proto = CEPH_MONC_PROTOCOL;
1472 		break;
1473 	case CEPH_ENTITY_TYPE_OSD:
1474 		proto = CEPH_OSDC_PROTOCOL;
1475 		break;
1476 	case CEPH_ENTITY_TYPE_MDS:
1477 		proto = CEPH_MDSC_PROTOCOL;
1478 		break;
1479 	default:
1480 		BUG();
1481 	}
1482 
1483 	dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
1484 	     con->connect_seq, global_seq, proto);
1485 
1486 	con->out_connect.features =
1487 	    cpu_to_le64(from_msgr(con->msgr)->supported_features);
1488 	con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
1489 	con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
1490 	con->out_connect.global_seq = cpu_to_le32(global_seq);
1491 	con->out_connect.protocol_version = cpu_to_le32(proto);
1492 	con->out_connect.flags = 0;
1493 
1494 	ret = get_connect_authorizer(con);
1495 	if (ret)
1496 		return ret;
1497 
1498 	__prepare_write_connect(con);
1499 	return 0;
1500 }
1501 
1502 /*
1503  * write as much of pending kvecs to the socket as we can.
1504  *  1 -> done
1505  *  0 -> socket full, but more to do
1506  * <0 -> error
1507  */
1508 static int write_partial_kvec(struct ceph_connection *con)
1509 {
1510 	int ret;
1511 
1512 	dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
1513 	while (con->out_kvec_bytes > 0) {
1514 		ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
1515 				       con->out_kvec_left, con->out_kvec_bytes,
1516 				       con->out_more);
1517 		if (ret <= 0)
1518 			goto out;
1519 		con->out_kvec_bytes -= ret;
1520 		if (con->out_kvec_bytes == 0)
1521 			break;            /* done */
1522 
1523 		/* account for full iov entries consumed */
1524 		while (ret >= con->out_kvec_cur->iov_len) {
1525 			BUG_ON(!con->out_kvec_left);
1526 			ret -= con->out_kvec_cur->iov_len;
1527 			con->out_kvec_cur++;
1528 			con->out_kvec_left--;
1529 		}
1530 		/* and for a partially-consumed entry */
1531 		if (ret) {
1532 			con->out_kvec_cur->iov_len -= ret;
1533 			con->out_kvec_cur->iov_base += ret;
1534 		}
1535 	}
1536 	con->out_kvec_left = 0;
1537 	ret = 1;
1538 out:
1539 	dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
1540 	     con->out_kvec_bytes, con->out_kvec_left, ret);
1541 	return ret;  /* done! */
1542 }
1543 
1544 static u32 ceph_crc32c_page(u32 crc, struct page *page,
1545 				unsigned int page_offset,
1546 				unsigned int length)
1547 {
1548 	char *kaddr;
1549 
1550 	kaddr = kmap(page);
1551 	BUG_ON(kaddr == NULL);
1552 	crc = crc32c(crc, kaddr + page_offset, length);
1553 	kunmap(page);
1554 
1555 	return crc;
1556 }
1557 /*
1558  * Write as much message data payload as we can.  If we finish, queue
1559  * up the footer.
1560  *  1 -> done, footer is now queued in out_kvec[].
1561  *  0 -> socket full, but more to do
1562  * <0 -> error
1563  */
1564 static int write_partial_message_data(struct ceph_connection *con)
1565 {
1566 	struct ceph_msg *msg = con->out_msg;
1567 	struct ceph_msg_data_cursor *cursor = &msg->cursor;
1568 	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
1569 	u32 crc;
1570 
1571 	dout("%s %p msg %p\n", __func__, con, msg);
1572 
1573 	if (!msg->num_data_items)
1574 		return -EINVAL;
1575 
1576 	/*
1577 	 * Iterate through each page that contains data to be
1578 	 * written, and send as much as possible for each.
1579 	 *
1580 	 * If we are calculating the data crc (the default), we will
1581 	 * need to map the page.  If we have no pages, they have
1582 	 * been revoked, so use the zero page.
1583 	 */
1584 	crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
1585 	while (cursor->total_resid) {
1586 		struct page *page;
1587 		size_t page_offset;
1588 		size_t length;
1589 		bool last_piece;
1590 		int ret;
1591 
1592 		if (!cursor->resid) {
1593 			ceph_msg_data_advance(cursor, 0);
1594 			continue;
1595 		}
1596 
1597 		page = ceph_msg_data_next(cursor, &page_offset, &length,
1598 					  &last_piece);
1599 		ret = ceph_tcp_sendpage(con->sock, page, page_offset,
1600 					length, !last_piece);
1601 		if (ret <= 0) {
1602 			if (do_datacrc)
1603 				msg->footer.data_crc = cpu_to_le32(crc);
1604 
1605 			return ret;
1606 		}
1607 		if (do_datacrc && cursor->need_crc)
1608 			crc = ceph_crc32c_page(crc, page, page_offset, length);
1609 		ceph_msg_data_advance(cursor, (size_t)ret);
1610 	}
1611 
1612 	dout("%s %p msg %p done\n", __func__, con, msg);
1613 
1614 	/* prepare and queue up footer, too */
1615 	if (do_datacrc)
1616 		msg->footer.data_crc = cpu_to_le32(crc);
1617 	else
1618 		msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
1619 	con_out_kvec_reset(con);
1620 	prepare_write_message_footer(con);
1621 
1622 	return 1;	/* must return > 0 to indicate success */
1623 }
1624 
1625 /*
1626  * write some zeros
1627  */
1628 static int write_partial_skip(struct ceph_connection *con)
1629 {
1630 	int ret;
1631 
1632 	dout("%s %p %d left\n", __func__, con, con->out_skip);
1633 	while (con->out_skip > 0) {
1634 		size_t size = min(con->out_skip, (int) PAGE_SIZE);
1635 
1636 		ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, true);
1637 		if (ret <= 0)
1638 			goto out;
1639 		con->out_skip -= ret;
1640 	}
1641 	ret = 1;
1642 out:
1643 	return ret;
1644 }
1645 
1646 /*
1647  * Prepare to read connection handshake, or an ack.
1648  */
1649 static void prepare_read_banner(struct ceph_connection *con)
1650 {
1651 	dout("prepare_read_banner %p\n", con);
1652 	con->in_base_pos = 0;
1653 }
1654 
1655 static void prepare_read_connect(struct ceph_connection *con)
1656 {
1657 	dout("prepare_read_connect %p\n", con);
1658 	con->in_base_pos = 0;
1659 }
1660 
1661 static void prepare_read_ack(struct ceph_connection *con)
1662 {
1663 	dout("prepare_read_ack %p\n", con);
1664 	con->in_base_pos = 0;
1665 }
1666 
1667 static void prepare_read_seq(struct ceph_connection *con)
1668 {
1669 	dout("prepare_read_seq %p\n", con);
1670 	con->in_base_pos = 0;
1671 	con->in_tag = CEPH_MSGR_TAG_SEQ;
1672 }
1673 
1674 static void prepare_read_tag(struct ceph_connection *con)
1675 {
1676 	dout("prepare_read_tag %p\n", con);
1677 	con->in_base_pos = 0;
1678 	con->in_tag = CEPH_MSGR_TAG_READY;
1679 }
1680 
1681 static void prepare_read_keepalive_ack(struct ceph_connection *con)
1682 {
1683 	dout("prepare_read_keepalive_ack %p\n", con);
1684 	con->in_base_pos = 0;
1685 }
1686 
1687 /*
1688  * Prepare to read a message.
1689  */
1690 static int prepare_read_message(struct ceph_connection *con)
1691 {
1692 	dout("prepare_read_message %p\n", con);
1693 	BUG_ON(con->in_msg != NULL);
1694 	con->in_base_pos = 0;
1695 	con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
1696 	return 0;
1697 }
1698 
1699 
1700 static int read_partial(struct ceph_connection *con,
1701 			int end, int size, void *object)
1702 {
1703 	while (con->in_base_pos < end) {
1704 		int left = end - con->in_base_pos;
1705 		int have = size - left;
1706 		int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
1707 		if (ret <= 0)
1708 			return ret;
1709 		con->in_base_pos += ret;
1710 	}
1711 	return 1;
1712 }
1713 
1714 
1715 /*
1716  * Read all or part of the connect-side handshake on a new connection
1717  */
1718 static int read_partial_banner(struct ceph_connection *con)
1719 {
1720 	int size;
1721 	int end;
1722 	int ret;
1723 
1724 	dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
1725 
1726 	/* peer's banner */
1727 	size = strlen(CEPH_BANNER);
1728 	end = size;
1729 	ret = read_partial(con, end, size, con->in_banner);
1730 	if (ret <= 0)
1731 		goto out;
1732 
1733 	size = sizeof (con->actual_peer_addr);
1734 	end += size;
1735 	ret = read_partial(con, end, size, &con->actual_peer_addr);
1736 	if (ret <= 0)
1737 		goto out;
1738 
1739 	size = sizeof (con->peer_addr_for_me);
1740 	end += size;
1741 	ret = read_partial(con, end, size, &con->peer_addr_for_me);
1742 	if (ret <= 0)
1743 		goto out;
1744 
1745 out:
1746 	return ret;
1747 }
1748 
1749 static int read_partial_connect(struct ceph_connection *con)
1750 {
1751 	int size;
1752 	int end;
1753 	int ret;
1754 
1755 	dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
1756 
1757 	size = sizeof (con->in_reply);
1758 	end = size;
1759 	ret = read_partial(con, end, size, &con->in_reply);
1760 	if (ret <= 0)
1761 		goto out;
1762 
1763 	if (con->auth) {
1764 		size = le32_to_cpu(con->in_reply.authorizer_len);
1765 		if (size > con->auth->authorizer_reply_buf_len) {
1766 			pr_err("authorizer reply too big: %d > %zu\n", size,
1767 			       con->auth->authorizer_reply_buf_len);
1768 			ret = -EINVAL;
1769 			goto out;
1770 		}
1771 
1772 		end += size;
1773 		ret = read_partial(con, end, size,
1774 				   con->auth->authorizer_reply_buf);
1775 		if (ret <= 0)
1776 			goto out;
1777 	}
1778 
1779 	dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
1780 	     con, (int)con->in_reply.tag,
1781 	     le32_to_cpu(con->in_reply.connect_seq),
1782 	     le32_to_cpu(con->in_reply.global_seq));
1783 out:
1784 	return ret;
1785 }
1786 
1787 /*
1788  * Verify the hello banner looks okay.
1789  */
1790 static int verify_hello(struct ceph_connection *con)
1791 {
1792 	if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
1793 		pr_err("connect to %s got bad banner\n",
1794 		       ceph_pr_addr(&con->peer_addr.in_addr));
1795 		con->error_msg = "protocol error, bad banner";
1796 		return -1;
1797 	}
1798 	return 0;
1799 }
1800 
1801 static bool addr_is_blank(struct sockaddr_storage *ss)
1802 {
1803 	struct in_addr *addr = &((struct sockaddr_in *)ss)->sin_addr;
1804 	struct in6_addr *addr6 = &((struct sockaddr_in6 *)ss)->sin6_addr;
1805 
1806 	switch (ss->ss_family) {
1807 	case AF_INET:
1808 		return addr->s_addr == htonl(INADDR_ANY);
1809 	case AF_INET6:
1810 		return ipv6_addr_any(addr6);
1811 	default:
1812 		return true;
1813 	}
1814 }
1815 
1816 static int addr_port(struct sockaddr_storage *ss)
1817 {
1818 	switch (ss->ss_family) {
1819 	case AF_INET:
1820 		return ntohs(((struct sockaddr_in *)ss)->sin_port);
1821 	case AF_INET6:
1822 		return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
1823 	}
1824 	return 0;
1825 }
1826 
1827 static void addr_set_port(struct sockaddr_storage *ss, int p)
1828 {
1829 	switch (ss->ss_family) {
1830 	case AF_INET:
1831 		((struct sockaddr_in *)ss)->sin_port = htons(p);
1832 		break;
1833 	case AF_INET6:
1834 		((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
1835 		break;
1836 	}
1837 }
1838 
1839 /*
1840  * Unlike other *_pton function semantics, zero indicates success.
1841  */
1842 static int ceph_pton(const char *str, size_t len, struct sockaddr_storage *ss,
1843 		char delim, const char **ipend)
1844 {
1845 	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
1846 	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
1847 
1848 	memset(ss, 0, sizeof(*ss));
1849 
1850 	if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) {
1851 		ss->ss_family = AF_INET;
1852 		return 0;
1853 	}
1854 
1855 	if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) {
1856 		ss->ss_family = AF_INET6;
1857 		return 0;
1858 	}
1859 
1860 	return -EINVAL;
1861 }
1862 
1863 /*
1864  * Extract hostname string and resolve using kernel DNS facility.
1865  */
1866 #ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
1867 static int ceph_dns_resolve_name(const char *name, size_t namelen,
1868 		struct sockaddr_storage *ss, char delim, const char **ipend)
1869 {
1870 	const char *end, *delim_p;
1871 	char *colon_p, *ip_addr = NULL;
1872 	int ip_len, ret;
1873 
1874 	/*
1875 	 * The end of the hostname occurs immediately preceding the delimiter or
1876 	 * the port marker (':') where the delimiter takes precedence.
1877 	 */
1878 	delim_p = memchr(name, delim, namelen);
1879 	colon_p = memchr(name, ':', namelen);
1880 
1881 	if (delim_p && colon_p)
1882 		end = delim_p < colon_p ? delim_p : colon_p;
1883 	else if (!delim_p && colon_p)
1884 		end = colon_p;
1885 	else {
1886 		end = delim_p;
1887 		if (!end) /* case: hostname:/ */
1888 			end = name + namelen;
1889 	}
1890 
1891 	if (end <= name)
1892 		return -EINVAL;
1893 
1894 	/* do dns_resolve upcall */
1895 	ip_len = dns_query(NULL, name, end - name, NULL, &ip_addr, NULL);
1896 	if (ip_len > 0)
1897 		ret = ceph_pton(ip_addr, ip_len, ss, -1, NULL);
1898 	else
1899 		ret = -ESRCH;
1900 
1901 	kfree(ip_addr);
1902 
1903 	*ipend = end;
1904 
1905 	pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
1906 			ret, ret ? "failed" : ceph_pr_addr(ss));
1907 
1908 	return ret;
1909 }
1910 #else
1911 static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
1912 		struct sockaddr_storage *ss, char delim, const char **ipend)
1913 {
1914 	return -EINVAL;
1915 }
1916 #endif
1917 
1918 /*
1919  * Parse a server name (IP or hostname). If a valid IP address is not found
1920  * then try to extract a hostname to resolve using userspace DNS upcall.
1921  */
1922 static int ceph_parse_server_name(const char *name, size_t namelen,
1923 			struct sockaddr_storage *ss, char delim, const char **ipend)
1924 {
1925 	int ret;
1926 
1927 	ret = ceph_pton(name, namelen, ss, delim, ipend);
1928 	if (ret)
1929 		ret = ceph_dns_resolve_name(name, namelen, ss, delim, ipend);
1930 
1931 	return ret;
1932 }
1933 
1934 /*
1935  * Parse an ip[:port] list into an addr array.  Use the default
1936  * monitor port if a port isn't specified.
1937  */
1938 int ceph_parse_ips(const char *c, const char *end,
1939 		   struct ceph_entity_addr *addr,
1940 		   int max_count, int *count)
1941 {
1942 	int i, ret = -EINVAL;
1943 	const char *p = c;
1944 
1945 	dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1946 	for (i = 0; i < max_count; i++) {
1947 		const char *ipend;
1948 		struct sockaddr_storage *ss = &addr[i].in_addr;
1949 		int port;
1950 		char delim = ',';
1951 
1952 		if (*p == '[') {
1953 			delim = ']';
1954 			p++;
1955 		}
1956 
1957 		ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend);
1958 		if (ret)
1959 			goto bad;
1960 		ret = -EINVAL;
1961 
1962 		p = ipend;
1963 
1964 		if (delim == ']') {
1965 			if (*p != ']') {
1966 				dout("missing matching ']'\n");
1967 				goto bad;
1968 			}
1969 			p++;
1970 		}
1971 
1972 		/* port? */
1973 		if (p < end && *p == ':') {
1974 			port = 0;
1975 			p++;
1976 			while (p < end && *p >= '0' && *p <= '9') {
1977 				port = (port * 10) + (*p - '0');
1978 				p++;
1979 			}
1980 			if (port == 0)
1981 				port = CEPH_MON_PORT;
1982 			else if (port > 65535)
1983 				goto bad;
1984 		} else {
1985 			port = CEPH_MON_PORT;
1986 		}
1987 
1988 		addr_set_port(ss, port);
1989 
1990 		dout("parse_ips got %s\n", ceph_pr_addr(ss));
1991 
1992 		if (p == end)
1993 			break;
1994 		if (*p != ',')
1995 			goto bad;
1996 		p++;
1997 	}
1998 
1999 	if (p != end)
2000 		goto bad;
2001 
2002 	if (count)
2003 		*count = i + 1;
2004 	return 0;
2005 
2006 bad:
2007 	pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
2008 	return ret;
2009 }
2010 EXPORT_SYMBOL(ceph_parse_ips);
2011 
2012 static int process_banner(struct ceph_connection *con)
2013 {
2014 	dout("process_banner on %p\n", con);
2015 
2016 	if (verify_hello(con) < 0)
2017 		return -1;
2018 
2019 	ceph_decode_addr(&con->actual_peer_addr);
2020 	ceph_decode_addr(&con->peer_addr_for_me);
2021 
2022 	/*
2023 	 * Make sure the other end is who we wanted.  note that the other
2024 	 * end may not yet know their ip address, so if it's 0.0.0.0, give
2025 	 * them the benefit of the doubt.
2026 	 */
2027 	if (memcmp(&con->peer_addr, &con->actual_peer_addr,
2028 		   sizeof(con->peer_addr)) != 0 &&
2029 	    !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
2030 	      con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
2031 		pr_warn("wrong peer, want %s/%d, got %s/%d\n",
2032 			ceph_pr_addr(&con->peer_addr.in_addr),
2033 			(int)le32_to_cpu(con->peer_addr.nonce),
2034 			ceph_pr_addr(&con->actual_peer_addr.in_addr),
2035 			(int)le32_to_cpu(con->actual_peer_addr.nonce));
2036 		con->error_msg = "wrong peer at address";
2037 		return -1;
2038 	}
2039 
2040 	/*
2041 	 * did we learn our address?
2042 	 */
2043 	if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
2044 		int port = addr_port(&con->msgr->inst.addr.in_addr);
2045 
2046 		memcpy(&con->msgr->inst.addr.in_addr,
2047 		       &con->peer_addr_for_me.in_addr,
2048 		       sizeof(con->peer_addr_for_me.in_addr));
2049 		addr_set_port(&con->msgr->inst.addr.in_addr, port);
2050 		encode_my_addr(con->msgr);
2051 		dout("process_banner learned my addr is %s\n",
2052 		     ceph_pr_addr(&con->msgr->inst.addr.in_addr));
2053 	}
2054 
2055 	return 0;
2056 }
2057 
2058 static int process_connect(struct ceph_connection *con)
2059 {
2060 	u64 sup_feat = from_msgr(con->msgr)->supported_features;
2061 	u64 req_feat = from_msgr(con->msgr)->required_features;
2062 	u64 server_feat = le64_to_cpu(con->in_reply.features);
2063 	int ret;
2064 
2065 	dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
2066 
2067 	if (con->auth) {
2068 		/*
2069 		 * Any connection that defines ->get_authorizer()
2070 		 * should also define ->add_authorizer_challenge() and
2071 		 * ->verify_authorizer_reply().
2072 		 *
2073 		 * See get_connect_authorizer().
2074 		 */
2075 		if (con->in_reply.tag == CEPH_MSGR_TAG_CHALLENGE_AUTHORIZER) {
2076 			ret = con->ops->add_authorizer_challenge(
2077 				    con, con->auth->authorizer_reply_buf,
2078 				    le32_to_cpu(con->in_reply.authorizer_len));
2079 			if (ret < 0)
2080 				return ret;
2081 
2082 			con_out_kvec_reset(con);
2083 			__prepare_write_connect(con);
2084 			prepare_read_connect(con);
2085 			return 0;
2086 		}
2087 
2088 		ret = con->ops->verify_authorizer_reply(con);
2089 		if (ret < 0) {
2090 			con->error_msg = "bad authorize reply";
2091 			return ret;
2092 		}
2093 	}
2094 
2095 	switch (con->in_reply.tag) {
2096 	case CEPH_MSGR_TAG_FEATURES:
2097 		pr_err("%s%lld %s feature set mismatch,"
2098 		       " my %llx < server's %llx, missing %llx\n",
2099 		       ENTITY_NAME(con->peer_name),
2100 		       ceph_pr_addr(&con->peer_addr.in_addr),
2101 		       sup_feat, server_feat, server_feat & ~sup_feat);
2102 		con->error_msg = "missing required protocol features";
2103 		reset_connection(con);
2104 		return -1;
2105 
2106 	case CEPH_MSGR_TAG_BADPROTOVER:
2107 		pr_err("%s%lld %s protocol version mismatch,"
2108 		       " my %d != server's %d\n",
2109 		       ENTITY_NAME(con->peer_name),
2110 		       ceph_pr_addr(&con->peer_addr.in_addr),
2111 		       le32_to_cpu(con->out_connect.protocol_version),
2112 		       le32_to_cpu(con->in_reply.protocol_version));
2113 		con->error_msg = "protocol version mismatch";
2114 		reset_connection(con);
2115 		return -1;
2116 
2117 	case CEPH_MSGR_TAG_BADAUTHORIZER:
2118 		con->auth_retry++;
2119 		dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
2120 		     con->auth_retry);
2121 		if (con->auth_retry == 2) {
2122 			con->error_msg = "connect authorization failure";
2123 			return -1;
2124 		}
2125 		con_out_kvec_reset(con);
2126 		ret = prepare_write_connect(con);
2127 		if (ret < 0)
2128 			return ret;
2129 		prepare_read_connect(con);
2130 		break;
2131 
2132 	case CEPH_MSGR_TAG_RESETSESSION:
2133 		/*
2134 		 * If we connected with a large connect_seq but the peer
2135 		 * has no record of a session with us (no connection, or
2136 		 * connect_seq == 0), they will send RESETSESION to indicate
2137 		 * that they must have reset their session, and may have
2138 		 * dropped messages.
2139 		 */
2140 		dout("process_connect got RESET peer seq %u\n",
2141 		     le32_to_cpu(con->in_reply.connect_seq));
2142 		pr_err("%s%lld %s connection reset\n",
2143 		       ENTITY_NAME(con->peer_name),
2144 		       ceph_pr_addr(&con->peer_addr.in_addr));
2145 		reset_connection(con);
2146 		con_out_kvec_reset(con);
2147 		ret = prepare_write_connect(con);
2148 		if (ret < 0)
2149 			return ret;
2150 		prepare_read_connect(con);
2151 
2152 		/* Tell ceph about it. */
2153 		mutex_unlock(&con->mutex);
2154 		pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
2155 		if (con->ops->peer_reset)
2156 			con->ops->peer_reset(con);
2157 		mutex_lock(&con->mutex);
2158 		if (con->state != CON_STATE_NEGOTIATING)
2159 			return -EAGAIN;
2160 		break;
2161 
2162 	case CEPH_MSGR_TAG_RETRY_SESSION:
2163 		/*
2164 		 * If we sent a smaller connect_seq than the peer has, try
2165 		 * again with a larger value.
2166 		 */
2167 		dout("process_connect got RETRY_SESSION my seq %u, peer %u\n",
2168 		     le32_to_cpu(con->out_connect.connect_seq),
2169 		     le32_to_cpu(con->in_reply.connect_seq));
2170 		con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
2171 		con_out_kvec_reset(con);
2172 		ret = prepare_write_connect(con);
2173 		if (ret < 0)
2174 			return ret;
2175 		prepare_read_connect(con);
2176 		break;
2177 
2178 	case CEPH_MSGR_TAG_RETRY_GLOBAL:
2179 		/*
2180 		 * If we sent a smaller global_seq than the peer has, try
2181 		 * again with a larger value.
2182 		 */
2183 		dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
2184 		     con->peer_global_seq,
2185 		     le32_to_cpu(con->in_reply.global_seq));
2186 		get_global_seq(con->msgr,
2187 			       le32_to_cpu(con->in_reply.global_seq));
2188 		con_out_kvec_reset(con);
2189 		ret = prepare_write_connect(con);
2190 		if (ret < 0)
2191 			return ret;
2192 		prepare_read_connect(con);
2193 		break;
2194 
2195 	case CEPH_MSGR_TAG_SEQ:
2196 	case CEPH_MSGR_TAG_READY:
2197 		if (req_feat & ~server_feat) {
2198 			pr_err("%s%lld %s protocol feature mismatch,"
2199 			       " my required %llx > server's %llx, need %llx\n",
2200 			       ENTITY_NAME(con->peer_name),
2201 			       ceph_pr_addr(&con->peer_addr.in_addr),
2202 			       req_feat, server_feat, req_feat & ~server_feat);
2203 			con->error_msg = "missing required protocol features";
2204 			reset_connection(con);
2205 			return -1;
2206 		}
2207 
2208 		WARN_ON(con->state != CON_STATE_NEGOTIATING);
2209 		con->state = CON_STATE_OPEN;
2210 		con->auth_retry = 0;    /* we authenticated; clear flag */
2211 		con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
2212 		con->connect_seq++;
2213 		con->peer_features = server_feat;
2214 		dout("process_connect got READY gseq %d cseq %d (%d)\n",
2215 		     con->peer_global_seq,
2216 		     le32_to_cpu(con->in_reply.connect_seq),
2217 		     con->connect_seq);
2218 		WARN_ON(con->connect_seq !=
2219 			le32_to_cpu(con->in_reply.connect_seq));
2220 
2221 		if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
2222 			con_flag_set(con, CON_FLAG_LOSSYTX);
2223 
2224 		con->delay = 0;      /* reset backoff memory */
2225 
2226 		if (con->in_reply.tag == CEPH_MSGR_TAG_SEQ) {
2227 			prepare_write_seq(con);
2228 			prepare_read_seq(con);
2229 		} else {
2230 			prepare_read_tag(con);
2231 		}
2232 		break;
2233 
2234 	case CEPH_MSGR_TAG_WAIT:
2235 		/*
2236 		 * If there is a connection race (we are opening
2237 		 * connections to each other), one of us may just have
2238 		 * to WAIT.  This shouldn't happen if we are the
2239 		 * client.
2240 		 */
2241 		con->error_msg = "protocol error, got WAIT as client";
2242 		return -1;
2243 
2244 	default:
2245 		con->error_msg = "protocol error, garbage tag during connect";
2246 		return -1;
2247 	}
2248 	return 0;
2249 }
2250 
2251 
2252 /*
2253  * read (part of) an ack
2254  */
2255 static int read_partial_ack(struct ceph_connection *con)
2256 {
2257 	int size = sizeof (con->in_temp_ack);
2258 	int end = size;
2259 
2260 	return read_partial(con, end, size, &con->in_temp_ack);
2261 }
2262 
2263 /*
2264  * We can finally discard anything that's been acked.
2265  */
2266 static void process_ack(struct ceph_connection *con)
2267 {
2268 	struct ceph_msg *m;
2269 	u64 ack = le64_to_cpu(con->in_temp_ack);
2270 	u64 seq;
2271 	bool reconnect = (con->in_tag == CEPH_MSGR_TAG_SEQ);
2272 	struct list_head *list = reconnect ? &con->out_queue : &con->out_sent;
2273 
2274 	/*
2275 	 * In the reconnect case, con_fault() has requeued messages
2276 	 * in out_sent. We should cleanup old messages according to
2277 	 * the reconnect seq.
2278 	 */
2279 	while (!list_empty(list)) {
2280 		m = list_first_entry(list, struct ceph_msg, list_head);
2281 		if (reconnect && m->needs_out_seq)
2282 			break;
2283 		seq = le64_to_cpu(m->hdr.seq);
2284 		if (seq > ack)
2285 			break;
2286 		dout("got ack for seq %llu type %d at %p\n", seq,
2287 		     le16_to_cpu(m->hdr.type), m);
2288 		m->ack_stamp = jiffies;
2289 		ceph_msg_remove(m);
2290 	}
2291 
2292 	prepare_read_tag(con);
2293 }
2294 
2295 
2296 static int read_partial_message_section(struct ceph_connection *con,
2297 					struct kvec *section,
2298 					unsigned int sec_len, u32 *crc)
2299 {
2300 	int ret, left;
2301 
2302 	BUG_ON(!section);
2303 
2304 	while (section->iov_len < sec_len) {
2305 		BUG_ON(section->iov_base == NULL);
2306 		left = sec_len - section->iov_len;
2307 		ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
2308 				       section->iov_len, left);
2309 		if (ret <= 0)
2310 			return ret;
2311 		section->iov_len += ret;
2312 	}
2313 	if (section->iov_len == sec_len)
2314 		*crc = crc32c(0, section->iov_base, section->iov_len);
2315 
2316 	return 1;
2317 }
2318 
2319 static int read_partial_msg_data(struct ceph_connection *con)
2320 {
2321 	struct ceph_msg *msg = con->in_msg;
2322 	struct ceph_msg_data_cursor *cursor = &msg->cursor;
2323 	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
2324 	struct page *page;
2325 	size_t page_offset;
2326 	size_t length;
2327 	u32 crc = 0;
2328 	int ret;
2329 
2330 	if (!msg->num_data_items)
2331 		return -EIO;
2332 
2333 	if (do_datacrc)
2334 		crc = con->in_data_crc;
2335 	while (cursor->total_resid) {
2336 		if (!cursor->resid) {
2337 			ceph_msg_data_advance(cursor, 0);
2338 			continue;
2339 		}
2340 
2341 		page = ceph_msg_data_next(cursor, &page_offset, &length, NULL);
2342 		ret = ceph_tcp_recvpage(con->sock, page, page_offset, length);
2343 		if (ret <= 0) {
2344 			if (do_datacrc)
2345 				con->in_data_crc = crc;
2346 
2347 			return ret;
2348 		}
2349 
2350 		if (do_datacrc)
2351 			crc = ceph_crc32c_page(crc, page, page_offset, ret);
2352 		ceph_msg_data_advance(cursor, (size_t)ret);
2353 	}
2354 	if (do_datacrc)
2355 		con->in_data_crc = crc;
2356 
2357 	return 1;	/* must return > 0 to indicate success */
2358 }
2359 
2360 /*
2361  * read (part of) a message.
2362  */
2363 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);
2364 
2365 static int read_partial_message(struct ceph_connection *con)
2366 {
2367 	struct ceph_msg *m = con->in_msg;
2368 	int size;
2369 	int end;
2370 	int ret;
2371 	unsigned int front_len, middle_len, data_len;
2372 	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
2373 	bool need_sign = (con->peer_features & CEPH_FEATURE_MSG_AUTH);
2374 	u64 seq;
2375 	u32 crc;
2376 
2377 	dout("read_partial_message con %p msg %p\n", con, m);
2378 
2379 	/* header */
2380 	size = sizeof (con->in_hdr);
2381 	end = size;
2382 	ret = read_partial(con, end, size, &con->in_hdr);
2383 	if (ret <= 0)
2384 		return ret;
2385 
2386 	crc = crc32c(0, &con->in_hdr, offsetof(struct ceph_msg_header, crc));
2387 	if (cpu_to_le32(crc) != con->in_hdr.crc) {
2388 		pr_err("read_partial_message bad hdr crc %u != expected %u\n",
2389 		       crc, con->in_hdr.crc);
2390 		return -EBADMSG;
2391 	}
2392 
2393 	front_len = le32_to_cpu(con->in_hdr.front_len);
2394 	if (front_len > CEPH_MSG_MAX_FRONT_LEN)
2395 		return -EIO;
2396 	middle_len = le32_to_cpu(con->in_hdr.middle_len);
2397 	if (middle_len > CEPH_MSG_MAX_MIDDLE_LEN)
2398 		return -EIO;
2399 	data_len = le32_to_cpu(con->in_hdr.data_len);
2400 	if (data_len > CEPH_MSG_MAX_DATA_LEN)
2401 		return -EIO;
2402 
2403 	/* verify seq# */
2404 	seq = le64_to_cpu(con->in_hdr.seq);
2405 	if ((s64)seq - (s64)con->in_seq < 1) {
2406 		pr_info("skipping %s%lld %s seq %lld expected %lld\n",
2407 			ENTITY_NAME(con->peer_name),
2408 			ceph_pr_addr(&con->peer_addr.in_addr),
2409 			seq, con->in_seq + 1);
2410 		con->in_base_pos = -front_len - middle_len - data_len -
2411 			sizeof_footer(con);
2412 		con->in_tag = CEPH_MSGR_TAG_READY;
2413 		return 1;
2414 	} else if ((s64)seq - (s64)con->in_seq > 1) {
2415 		pr_err("read_partial_message bad seq %lld expected %lld\n",
2416 		       seq, con->in_seq + 1);
2417 		con->error_msg = "bad message sequence # for incoming message";
2418 		return -EBADE;
2419 	}
2420 
2421 	/* allocate message? */
2422 	if (!con->in_msg) {
2423 		int skip = 0;
2424 
2425 		dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
2426 		     front_len, data_len);
2427 		ret = ceph_con_in_msg_alloc(con, &skip);
2428 		if (ret < 0)
2429 			return ret;
2430 
2431 		BUG_ON(!con->in_msg ^ skip);
2432 		if (skip) {
2433 			/* skip this message */
2434 			dout("alloc_msg said skip message\n");
2435 			con->in_base_pos = -front_len - middle_len - data_len -
2436 				sizeof_footer(con);
2437 			con->in_tag = CEPH_MSGR_TAG_READY;
2438 			con->in_seq++;
2439 			return 1;
2440 		}
2441 
2442 		BUG_ON(!con->in_msg);
2443 		BUG_ON(con->in_msg->con != con);
2444 		m = con->in_msg;
2445 		m->front.iov_len = 0;    /* haven't read it yet */
2446 		if (m->middle)
2447 			m->middle->vec.iov_len = 0;
2448 
2449 		/* prepare for data payload, if any */
2450 
2451 		if (data_len)
2452 			prepare_message_data(con->in_msg, data_len);
2453 	}
2454 
2455 	/* front */
2456 	ret = read_partial_message_section(con, &m->front, front_len,
2457 					   &con->in_front_crc);
2458 	if (ret <= 0)
2459 		return ret;
2460 
2461 	/* middle */
2462 	if (m->middle) {
2463 		ret = read_partial_message_section(con, &m->middle->vec,
2464 						   middle_len,
2465 						   &con->in_middle_crc);
2466 		if (ret <= 0)
2467 			return ret;
2468 	}
2469 
2470 	/* (page) data */
2471 	if (data_len) {
2472 		ret = read_partial_msg_data(con);
2473 		if (ret <= 0)
2474 			return ret;
2475 	}
2476 
2477 	/* footer */
2478 	size = sizeof_footer(con);
2479 	end += size;
2480 	ret = read_partial(con, end, size, &m->footer);
2481 	if (ret <= 0)
2482 		return ret;
2483 
2484 	if (!need_sign) {
2485 		m->footer.flags = m->old_footer.flags;
2486 		m->footer.sig = 0;
2487 	}
2488 
2489 	dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
2490 	     m, front_len, m->footer.front_crc, middle_len,
2491 	     m->footer.middle_crc, data_len, m->footer.data_crc);
2492 
2493 	/* crc ok? */
2494 	if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
2495 		pr_err("read_partial_message %p front crc %u != exp. %u\n",
2496 		       m, con->in_front_crc, m->footer.front_crc);
2497 		return -EBADMSG;
2498 	}
2499 	if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
2500 		pr_err("read_partial_message %p middle crc %u != exp %u\n",
2501 		       m, con->in_middle_crc, m->footer.middle_crc);
2502 		return -EBADMSG;
2503 	}
2504 	if (do_datacrc &&
2505 	    (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
2506 	    con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
2507 		pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
2508 		       con->in_data_crc, le32_to_cpu(m->footer.data_crc));
2509 		return -EBADMSG;
2510 	}
2511 
2512 	if (need_sign && con->ops->check_message_signature &&
2513 	    con->ops->check_message_signature(m)) {
2514 		pr_err("read_partial_message %p signature check failed\n", m);
2515 		return -EBADMSG;
2516 	}
2517 
2518 	return 1; /* done! */
2519 }
2520 
2521 /*
2522  * Process message.  This happens in the worker thread.  The callback should
2523  * be careful not to do anything that waits on other incoming messages or it
2524  * may deadlock.
2525  */
2526 static void process_message(struct ceph_connection *con)
2527 {
2528 	struct ceph_msg *msg = con->in_msg;
2529 
2530 	BUG_ON(con->in_msg->con != con);
2531 	con->in_msg = NULL;
2532 
2533 	/* if first message, set peer_name */
2534 	if (con->peer_name.type == 0)
2535 		con->peer_name = msg->hdr.src;
2536 
2537 	con->in_seq++;
2538 	mutex_unlock(&con->mutex);
2539 
2540 	dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
2541 	     msg, le64_to_cpu(msg->hdr.seq),
2542 	     ENTITY_NAME(msg->hdr.src),
2543 	     le16_to_cpu(msg->hdr.type),
2544 	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
2545 	     le32_to_cpu(msg->hdr.front_len),
2546 	     le32_to_cpu(msg->hdr.data_len),
2547 	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);
2548 	con->ops->dispatch(con, msg);
2549 
2550 	mutex_lock(&con->mutex);
2551 }
2552 
2553 static int read_keepalive_ack(struct ceph_connection *con)
2554 {
2555 	struct ceph_timespec ceph_ts;
2556 	size_t size = sizeof(ceph_ts);
2557 	int ret = read_partial(con, size, size, &ceph_ts);
2558 	if (ret <= 0)
2559 		return ret;
2560 	ceph_decode_timespec64(&con->last_keepalive_ack, &ceph_ts);
2561 	prepare_read_tag(con);
2562 	return 1;
2563 }
2564 
2565 /*
2566  * Write something to the socket.  Called in a worker thread when the
2567  * socket appears to be writeable and we have something ready to send.
2568  */
2569 static int try_write(struct ceph_connection *con)
2570 {
2571 	int ret = 1;
2572 
2573 	dout("try_write start %p state %lu\n", con, con->state);
2574 	if (con->state != CON_STATE_PREOPEN &&
2575 	    con->state != CON_STATE_CONNECTING &&
2576 	    con->state != CON_STATE_NEGOTIATING &&
2577 	    con->state != CON_STATE_OPEN)
2578 		return 0;
2579 
2580 	/* open the socket first? */
2581 	if (con->state == CON_STATE_PREOPEN) {
2582 		BUG_ON(con->sock);
2583 		con->state = CON_STATE_CONNECTING;
2584 
2585 		con_out_kvec_reset(con);
2586 		prepare_write_banner(con);
2587 		prepare_read_banner(con);
2588 
2589 		BUG_ON(con->in_msg);
2590 		con->in_tag = CEPH_MSGR_TAG_READY;
2591 		dout("try_write initiating connect on %p new state %lu\n",
2592 		     con, con->state);
2593 		ret = ceph_tcp_connect(con);
2594 		if (ret < 0) {
2595 			con->error_msg = "connect error";
2596 			goto out;
2597 		}
2598 	}
2599 
2600 more:
2601 	dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
2602 	BUG_ON(!con->sock);
2603 
2604 	/* kvec data queued? */
2605 	if (con->out_kvec_left) {
2606 		ret = write_partial_kvec(con);
2607 		if (ret <= 0)
2608 			goto out;
2609 	}
2610 	if (con->out_skip) {
2611 		ret = write_partial_skip(con);
2612 		if (ret <= 0)
2613 			goto out;
2614 	}
2615 
2616 	/* msg pages? */
2617 	if (con->out_msg) {
2618 		if (con->out_msg_done) {
2619 			ceph_msg_put(con->out_msg);
2620 			con->out_msg = NULL;   /* we're done with this one */
2621 			goto do_next;
2622 		}
2623 
2624 		ret = write_partial_message_data(con);
2625 		if (ret == 1)
2626 			goto more;  /* we need to send the footer, too! */
2627 		if (ret == 0)
2628 			goto out;
2629 		if (ret < 0) {
2630 			dout("try_write write_partial_message_data err %d\n",
2631 			     ret);
2632 			goto out;
2633 		}
2634 	}
2635 
2636 do_next:
2637 	if (con->state == CON_STATE_OPEN) {
2638 		if (con_flag_test_and_clear(con, CON_FLAG_KEEPALIVE_PENDING)) {
2639 			prepare_write_keepalive(con);
2640 			goto more;
2641 		}
2642 		/* is anything else pending? */
2643 		if (!list_empty(&con->out_queue)) {
2644 			prepare_write_message(con);
2645 			goto more;
2646 		}
2647 		if (con->in_seq > con->in_seq_acked) {
2648 			prepare_write_ack(con);
2649 			goto more;
2650 		}
2651 	}
2652 
2653 	/* Nothing to do! */
2654 	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
2655 	dout("try_write nothing else to write.\n");
2656 	ret = 0;
2657 out:
2658 	dout("try_write done on %p ret %d\n", con, ret);
2659 	return ret;
2660 }
2661 
2662 /*
2663  * Read what we can from the socket.
2664  */
2665 static int try_read(struct ceph_connection *con)
2666 {
2667 	int ret = -1;
2668 
2669 more:
2670 	dout("try_read start on %p state %lu\n", con, con->state);
2671 	if (con->state != CON_STATE_CONNECTING &&
2672 	    con->state != CON_STATE_NEGOTIATING &&
2673 	    con->state != CON_STATE_OPEN)
2674 		return 0;
2675 
2676 	BUG_ON(!con->sock);
2677 
2678 	dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
2679 	     con->in_base_pos);
2680 
2681 	if (con->state == CON_STATE_CONNECTING) {
2682 		dout("try_read connecting\n");
2683 		ret = read_partial_banner(con);
2684 		if (ret <= 0)
2685 			goto out;
2686 		ret = process_banner(con);
2687 		if (ret < 0)
2688 			goto out;
2689 
2690 		con->state = CON_STATE_NEGOTIATING;
2691 
2692 		/*
2693 		 * Received banner is good, exchange connection info.
2694 		 * Do not reset out_kvec, as sending our banner raced
2695 		 * with receiving peer banner after connect completed.
2696 		 */
2697 		ret = prepare_write_connect(con);
2698 		if (ret < 0)
2699 			goto out;
2700 		prepare_read_connect(con);
2701 
2702 		/* Send connection info before awaiting response */
2703 		goto out;
2704 	}
2705 
2706 	if (con->state == CON_STATE_NEGOTIATING) {
2707 		dout("try_read negotiating\n");
2708 		ret = read_partial_connect(con);
2709 		if (ret <= 0)
2710 			goto out;
2711 		ret = process_connect(con);
2712 		if (ret < 0)
2713 			goto out;
2714 		goto more;
2715 	}
2716 
2717 	WARN_ON(con->state != CON_STATE_OPEN);
2718 
2719 	if (con->in_base_pos < 0) {
2720 		/*
2721 		 * skipping + discarding content.
2722 		 */
2723 		ret = ceph_tcp_recvmsg(con->sock, NULL, -con->in_base_pos);
2724 		if (ret <= 0)
2725 			goto out;
2726 		dout("skipped %d / %d bytes\n", ret, -con->in_base_pos);
2727 		con->in_base_pos += ret;
2728 		if (con->in_base_pos)
2729 			goto more;
2730 	}
2731 	if (con->in_tag == CEPH_MSGR_TAG_READY) {
2732 		/*
2733 		 * what's next?
2734 		 */
2735 		ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
2736 		if (ret <= 0)
2737 			goto out;
2738 		dout("try_read got tag %d\n", (int)con->in_tag);
2739 		switch (con->in_tag) {
2740 		case CEPH_MSGR_TAG_MSG:
2741 			prepare_read_message(con);
2742 			break;
2743 		case CEPH_MSGR_TAG_ACK:
2744 			prepare_read_ack(con);
2745 			break;
2746 		case CEPH_MSGR_TAG_KEEPALIVE2_ACK:
2747 			prepare_read_keepalive_ack(con);
2748 			break;
2749 		case CEPH_MSGR_TAG_CLOSE:
2750 			con_close_socket(con);
2751 			con->state = CON_STATE_CLOSED;
2752 			goto out;
2753 		default:
2754 			goto bad_tag;
2755 		}
2756 	}
2757 	if (con->in_tag == CEPH_MSGR_TAG_MSG) {
2758 		ret = read_partial_message(con);
2759 		if (ret <= 0) {
2760 			switch (ret) {
2761 			case -EBADMSG:
2762 				con->error_msg = "bad crc/signature";
2763 				/* fall through */
2764 			case -EBADE:
2765 				ret = -EIO;
2766 				break;
2767 			case -EIO:
2768 				con->error_msg = "io error";
2769 				break;
2770 			}
2771 			goto out;
2772 		}
2773 		if (con->in_tag == CEPH_MSGR_TAG_READY)
2774 			goto more;
2775 		process_message(con);
2776 		if (con->state == CON_STATE_OPEN)
2777 			prepare_read_tag(con);
2778 		goto more;
2779 	}
2780 	if (con->in_tag == CEPH_MSGR_TAG_ACK ||
2781 	    con->in_tag == CEPH_MSGR_TAG_SEQ) {
2782 		/*
2783 		 * the final handshake seq exchange is semantically
2784 		 * equivalent to an ACK
2785 		 */
2786 		ret = read_partial_ack(con);
2787 		if (ret <= 0)
2788 			goto out;
2789 		process_ack(con);
2790 		goto more;
2791 	}
2792 	if (con->in_tag == CEPH_MSGR_TAG_KEEPALIVE2_ACK) {
2793 		ret = read_keepalive_ack(con);
2794 		if (ret <= 0)
2795 			goto out;
2796 		goto more;
2797 	}
2798 
2799 out:
2800 	dout("try_read done on %p ret %d\n", con, ret);
2801 	return ret;
2802 
2803 bad_tag:
2804 	pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
2805 	con->error_msg = "protocol error, garbage tag";
2806 	ret = -1;
2807 	goto out;
2808 }
2809 
2810 
2811 /*
2812  * Atomically queue work on a connection after the specified delay.
2813  * Bump @con reference to avoid races with connection teardown.
2814  * Returns 0 if work was queued, or an error code otherwise.
2815  */
2816 static int queue_con_delay(struct ceph_connection *con, unsigned long delay)
2817 {
2818 	if (!con->ops->get(con)) {
2819 		dout("%s %p ref count 0\n", __func__, con);
2820 		return -ENOENT;
2821 	}
2822 
2823 	if (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
2824 		dout("%s %p - already queued\n", __func__, con);
2825 		con->ops->put(con);
2826 		return -EBUSY;
2827 	}
2828 
2829 	dout("%s %p %lu\n", __func__, con, delay);
2830 	return 0;
2831 }
2832 
2833 static void queue_con(struct ceph_connection *con)
2834 {
2835 	(void) queue_con_delay(con, 0);
2836 }
2837 
2838 static void cancel_con(struct ceph_connection *con)
2839 {
2840 	if (cancel_delayed_work(&con->work)) {
2841 		dout("%s %p\n", __func__, con);
2842 		con->ops->put(con);
2843 	}
2844 }
2845 
2846 static bool con_sock_closed(struct ceph_connection *con)
2847 {
2848 	if (!con_flag_test_and_clear(con, CON_FLAG_SOCK_CLOSED))
2849 		return false;
2850 
2851 #define CASE(x)								\
2852 	case CON_STATE_ ## x:						\
2853 		con->error_msg = "socket closed (con state " #x ")";	\
2854 		break;
2855 
2856 	switch (con->state) {
2857 	CASE(CLOSED);
2858 	CASE(PREOPEN);
2859 	CASE(CONNECTING);
2860 	CASE(NEGOTIATING);
2861 	CASE(OPEN);
2862 	CASE(STANDBY);
2863 	default:
2864 		pr_warn("%s con %p unrecognized state %lu\n",
2865 			__func__, con, con->state);
2866 		con->error_msg = "unrecognized con state";
2867 		BUG();
2868 		break;
2869 	}
2870 #undef CASE
2871 
2872 	return true;
2873 }
2874 
2875 static bool con_backoff(struct ceph_connection *con)
2876 {
2877 	int ret;
2878 
2879 	if (!con_flag_test_and_clear(con, CON_FLAG_BACKOFF))
2880 		return false;
2881 
2882 	ret = queue_con_delay(con, round_jiffies_relative(con->delay));
2883 	if (ret) {
2884 		dout("%s: con %p FAILED to back off %lu\n", __func__,
2885 			con, con->delay);
2886 		BUG_ON(ret == -ENOENT);
2887 		con_flag_set(con, CON_FLAG_BACKOFF);
2888 	}
2889 
2890 	return true;
2891 }
2892 
2893 /* Finish fault handling; con->mutex must *not* be held here */
2894 
2895 static void con_fault_finish(struct ceph_connection *con)
2896 {
2897 	dout("%s %p\n", __func__, con);
2898 
2899 	/*
2900 	 * in case we faulted due to authentication, invalidate our
2901 	 * current tickets so that we can get new ones.
2902 	 */
2903 	if (con->auth_retry) {
2904 		dout("auth_retry %d, invalidating\n", con->auth_retry);
2905 		if (con->ops->invalidate_authorizer)
2906 			con->ops->invalidate_authorizer(con);
2907 		con->auth_retry = 0;
2908 	}
2909 
2910 	if (con->ops->fault)
2911 		con->ops->fault(con);
2912 }
2913 
2914 /*
2915  * Do some work on a connection.  Drop a connection ref when we're done.
2916  */
2917 static void ceph_con_workfn(struct work_struct *work)
2918 {
2919 	struct ceph_connection *con = container_of(work, struct ceph_connection,
2920 						   work.work);
2921 	bool fault;
2922 
2923 	mutex_lock(&con->mutex);
2924 	while (true) {
2925 		int ret;
2926 
2927 		if ((fault = con_sock_closed(con))) {
2928 			dout("%s: con %p SOCK_CLOSED\n", __func__, con);
2929 			break;
2930 		}
2931 		if (con_backoff(con)) {
2932 			dout("%s: con %p BACKOFF\n", __func__, con);
2933 			break;
2934 		}
2935 		if (con->state == CON_STATE_STANDBY) {
2936 			dout("%s: con %p STANDBY\n", __func__, con);
2937 			break;
2938 		}
2939 		if (con->state == CON_STATE_CLOSED) {
2940 			dout("%s: con %p CLOSED\n", __func__, con);
2941 			BUG_ON(con->sock);
2942 			break;
2943 		}
2944 		if (con->state == CON_STATE_PREOPEN) {
2945 			dout("%s: con %p PREOPEN\n", __func__, con);
2946 			BUG_ON(con->sock);
2947 		}
2948 
2949 		ret = try_read(con);
2950 		if (ret < 0) {
2951 			if (ret == -EAGAIN)
2952 				continue;
2953 			if (!con->error_msg)
2954 				con->error_msg = "socket error on read";
2955 			fault = true;
2956 			break;
2957 		}
2958 
2959 		ret = try_write(con);
2960 		if (ret < 0) {
2961 			if (ret == -EAGAIN)
2962 				continue;
2963 			if (!con->error_msg)
2964 				con->error_msg = "socket error on write";
2965 			fault = true;
2966 		}
2967 
2968 		break;	/* If we make it to here, we're done */
2969 	}
2970 	if (fault)
2971 		con_fault(con);
2972 	mutex_unlock(&con->mutex);
2973 
2974 	if (fault)
2975 		con_fault_finish(con);
2976 
2977 	con->ops->put(con);
2978 }
2979 
2980 /*
2981  * Generic error/fault handler.  A retry mechanism is used with
2982  * exponential backoff
2983  */
2984 static void con_fault(struct ceph_connection *con)
2985 {
2986 	dout("fault %p state %lu to peer %s\n",
2987 	     con, con->state, ceph_pr_addr(&con->peer_addr.in_addr));
2988 
2989 	pr_warn("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
2990 		ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
2991 	con->error_msg = NULL;
2992 
2993 	WARN_ON(con->state != CON_STATE_CONNECTING &&
2994 	       con->state != CON_STATE_NEGOTIATING &&
2995 	       con->state != CON_STATE_OPEN);
2996 
2997 	con_close_socket(con);
2998 
2999 	if (con_flag_test(con, CON_FLAG_LOSSYTX)) {
3000 		dout("fault on LOSSYTX channel, marking CLOSED\n");
3001 		con->state = CON_STATE_CLOSED;
3002 		return;
3003 	}
3004 
3005 	if (con->in_msg) {
3006 		BUG_ON(con->in_msg->con != con);
3007 		ceph_msg_put(con->in_msg);
3008 		con->in_msg = NULL;
3009 	}
3010 
3011 	/* Requeue anything that hasn't been acked */
3012 	list_splice_init(&con->out_sent, &con->out_queue);
3013 
3014 	/* If there are no messages queued or keepalive pending, place
3015 	 * the connection in a STANDBY state */
3016 	if (list_empty(&con->out_queue) &&
3017 	    !con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING)) {
3018 		dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
3019 		con_flag_clear(con, CON_FLAG_WRITE_PENDING);
3020 		con->state = CON_STATE_STANDBY;
3021 	} else {
3022 		/* retry after a delay. */
3023 		con->state = CON_STATE_PREOPEN;
3024 		if (con->delay == 0)
3025 			con->delay = BASE_DELAY_INTERVAL;
3026 		else if (con->delay < MAX_DELAY_INTERVAL)
3027 			con->delay *= 2;
3028 		con_flag_set(con, CON_FLAG_BACKOFF);
3029 		queue_con(con);
3030 	}
3031 }
3032 
3033 
3034 
3035 /*
3036  * initialize a new messenger instance
3037  */
3038 void ceph_messenger_init(struct ceph_messenger *msgr,
3039 			 struct ceph_entity_addr *myaddr)
3040 {
3041 	spin_lock_init(&msgr->global_seq_lock);
3042 
3043 	if (myaddr)
3044 		msgr->inst.addr = *myaddr;
3045 
3046 	/* select a random nonce */
3047 	msgr->inst.addr.type = 0;
3048 	get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
3049 	encode_my_addr(msgr);
3050 
3051 	atomic_set(&msgr->stopping, 0);
3052 	write_pnet(&msgr->net, get_net(current->nsproxy->net_ns));
3053 
3054 	dout("%s %p\n", __func__, msgr);
3055 }
3056 EXPORT_SYMBOL(ceph_messenger_init);
3057 
3058 void ceph_messenger_fini(struct ceph_messenger *msgr)
3059 {
3060 	put_net(read_pnet(&msgr->net));
3061 }
3062 EXPORT_SYMBOL(ceph_messenger_fini);
3063 
3064 static void msg_con_set(struct ceph_msg *msg, struct ceph_connection *con)
3065 {
3066 	if (msg->con)
3067 		msg->con->ops->put(msg->con);
3068 
3069 	msg->con = con ? con->ops->get(con) : NULL;
3070 	BUG_ON(msg->con != con);
3071 }
3072 
3073 static void clear_standby(struct ceph_connection *con)
3074 {
3075 	/* come back from STANDBY? */
3076 	if (con->state == CON_STATE_STANDBY) {
3077 		dout("clear_standby %p and ++connect_seq\n", con);
3078 		con->state = CON_STATE_PREOPEN;
3079 		con->connect_seq++;
3080 		WARN_ON(con_flag_test(con, CON_FLAG_WRITE_PENDING));
3081 		WARN_ON(con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING));
3082 	}
3083 }
3084 
3085 /*
3086  * Queue up an outgoing message on the given connection.
3087  */
3088 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
3089 {
3090 	/* set src+dst */
3091 	msg->hdr.src = con->msgr->inst.name;
3092 	BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
3093 	msg->needs_out_seq = true;
3094 
3095 	mutex_lock(&con->mutex);
3096 
3097 	if (con->state == CON_STATE_CLOSED) {
3098 		dout("con_send %p closed, dropping %p\n", con, msg);
3099 		ceph_msg_put(msg);
3100 		mutex_unlock(&con->mutex);
3101 		return;
3102 	}
3103 
3104 	msg_con_set(msg, con);
3105 
3106 	BUG_ON(!list_empty(&msg->list_head));
3107 	list_add_tail(&msg->list_head, &con->out_queue);
3108 	dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
3109 	     ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
3110 	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
3111 	     le32_to_cpu(msg->hdr.front_len),
3112 	     le32_to_cpu(msg->hdr.middle_len),
3113 	     le32_to_cpu(msg->hdr.data_len));
3114 
3115 	clear_standby(con);
3116 	mutex_unlock(&con->mutex);
3117 
3118 	/* if there wasn't anything waiting to send before, queue
3119 	 * new work */
3120 	if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
3121 		queue_con(con);
3122 }
3123 EXPORT_SYMBOL(ceph_con_send);
3124 
3125 /*
3126  * Revoke a message that was previously queued for send
3127  */
3128 void ceph_msg_revoke(struct ceph_msg *msg)
3129 {
3130 	struct ceph_connection *con = msg->con;
3131 
3132 	if (!con) {
3133 		dout("%s msg %p null con\n", __func__, msg);
3134 		return;		/* Message not in our possession */
3135 	}
3136 
3137 	mutex_lock(&con->mutex);
3138 	if (!list_empty(&msg->list_head)) {
3139 		dout("%s %p msg %p - was on queue\n", __func__, con, msg);
3140 		list_del_init(&msg->list_head);
3141 		msg->hdr.seq = 0;
3142 
3143 		ceph_msg_put(msg);
3144 	}
3145 	if (con->out_msg == msg) {
3146 		BUG_ON(con->out_skip);
3147 		/* footer */
3148 		if (con->out_msg_done) {
3149 			con->out_skip += con_out_kvec_skip(con);
3150 		} else {
3151 			BUG_ON(!msg->data_length);
3152 			con->out_skip += sizeof_footer(con);
3153 		}
3154 		/* data, middle, front */
3155 		if (msg->data_length)
3156 			con->out_skip += msg->cursor.total_resid;
3157 		if (msg->middle)
3158 			con->out_skip += con_out_kvec_skip(con);
3159 		con->out_skip += con_out_kvec_skip(con);
3160 
3161 		dout("%s %p msg %p - was sending, will write %d skip %d\n",
3162 		     __func__, con, msg, con->out_kvec_bytes, con->out_skip);
3163 		msg->hdr.seq = 0;
3164 		con->out_msg = NULL;
3165 		ceph_msg_put(msg);
3166 	}
3167 
3168 	mutex_unlock(&con->mutex);
3169 }
3170 
3171 /*
3172  * Revoke a message that we may be reading data into
3173  */
3174 void ceph_msg_revoke_incoming(struct ceph_msg *msg)
3175 {
3176 	struct ceph_connection *con = msg->con;
3177 
3178 	if (!con) {
3179 		dout("%s msg %p null con\n", __func__, msg);
3180 		return;		/* Message not in our possession */
3181 	}
3182 
3183 	mutex_lock(&con->mutex);
3184 	if (con->in_msg == msg) {
3185 		unsigned int front_len = le32_to_cpu(con->in_hdr.front_len);
3186 		unsigned int middle_len = le32_to_cpu(con->in_hdr.middle_len);
3187 		unsigned int data_len = le32_to_cpu(con->in_hdr.data_len);
3188 
3189 		/* skip rest of message */
3190 		dout("%s %p msg %p revoked\n", __func__, con, msg);
3191 		con->in_base_pos = con->in_base_pos -
3192 				sizeof(struct ceph_msg_header) -
3193 				front_len -
3194 				middle_len -
3195 				data_len -
3196 				sizeof(struct ceph_msg_footer);
3197 		ceph_msg_put(con->in_msg);
3198 		con->in_msg = NULL;
3199 		con->in_tag = CEPH_MSGR_TAG_READY;
3200 		con->in_seq++;
3201 	} else {
3202 		dout("%s %p in_msg %p msg %p no-op\n",
3203 		     __func__, con, con->in_msg, msg);
3204 	}
3205 	mutex_unlock(&con->mutex);
3206 }
3207 
3208 /*
3209  * Queue a keepalive byte to ensure the tcp connection is alive.
3210  */
3211 void ceph_con_keepalive(struct ceph_connection *con)
3212 {
3213 	dout("con_keepalive %p\n", con);
3214 	mutex_lock(&con->mutex);
3215 	clear_standby(con);
3216 	mutex_unlock(&con->mutex);
3217 	if (con_flag_test_and_set(con, CON_FLAG_KEEPALIVE_PENDING) == 0 &&
3218 	    con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
3219 		queue_con(con);
3220 }
3221 EXPORT_SYMBOL(ceph_con_keepalive);
3222 
3223 bool ceph_con_keepalive_expired(struct ceph_connection *con,
3224 			       unsigned long interval)
3225 {
3226 	if (interval > 0 &&
3227 	    (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
3228 		struct timespec64 now;
3229 		struct timespec64 ts;
3230 		ktime_get_real_ts64(&now);
3231 		jiffies_to_timespec64(interval, &ts);
3232 		ts = timespec64_add(con->last_keepalive_ack, ts);
3233 		return timespec64_compare(&now, &ts) >= 0;
3234 	}
3235 	return false;
3236 }
3237 
3238 static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
3239 {
3240 	BUG_ON(msg->num_data_items >= msg->max_data_items);
3241 	return &msg->data[msg->num_data_items++];
3242 }
3243 
3244 static void ceph_msg_data_destroy(struct ceph_msg_data *data)
3245 {
3246 	if (data->type == CEPH_MSG_DATA_PAGELIST)
3247 		ceph_pagelist_release(data->pagelist);
3248 }
3249 
3250 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
3251 		size_t length, size_t alignment)
3252 {
3253 	struct ceph_msg_data *data;
3254 
3255 	BUG_ON(!pages);
3256 	BUG_ON(!length);
3257 
3258 	data = ceph_msg_data_add(msg);
3259 	data->type = CEPH_MSG_DATA_PAGES;
3260 	data->pages = pages;
3261 	data->length = length;
3262 	data->alignment = alignment & ~PAGE_MASK;
3263 
3264 	msg->data_length += length;
3265 }
3266 EXPORT_SYMBOL(ceph_msg_data_add_pages);
3267 
3268 void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
3269 				struct ceph_pagelist *pagelist)
3270 {
3271 	struct ceph_msg_data *data;
3272 
3273 	BUG_ON(!pagelist);
3274 	BUG_ON(!pagelist->length);
3275 
3276 	data = ceph_msg_data_add(msg);
3277 	data->type = CEPH_MSG_DATA_PAGELIST;
3278 	refcount_inc(&pagelist->refcnt);
3279 	data->pagelist = pagelist;
3280 
3281 	msg->data_length += pagelist->length;
3282 }
3283 EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
3284 
3285 #ifdef	CONFIG_BLOCK
3286 void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
3287 			   u32 length)
3288 {
3289 	struct ceph_msg_data *data;
3290 
3291 	data = ceph_msg_data_add(msg);
3292 	data->type = CEPH_MSG_DATA_BIO;
3293 	data->bio_pos = *bio_pos;
3294 	data->bio_length = length;
3295 
3296 	msg->data_length += length;
3297 }
3298 EXPORT_SYMBOL(ceph_msg_data_add_bio);
3299 #endif	/* CONFIG_BLOCK */
3300 
3301 void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
3302 			     struct ceph_bvec_iter *bvec_pos)
3303 {
3304 	struct ceph_msg_data *data;
3305 
3306 	data = ceph_msg_data_add(msg);
3307 	data->type = CEPH_MSG_DATA_BVECS;
3308 	data->bvec_pos = *bvec_pos;
3309 
3310 	msg->data_length += bvec_pos->iter.bi_size;
3311 }
3312 EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
3313 
3314 /*
3315  * construct a new message with given type, size
3316  * the new msg has a ref count of 1.
3317  */
3318 struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
3319 			       gfp_t flags, bool can_fail)
3320 {
3321 	struct ceph_msg *m;
3322 
3323 	m = kmem_cache_zalloc(ceph_msg_cache, flags);
3324 	if (m == NULL)
3325 		goto out;
3326 
3327 	m->hdr.type = cpu_to_le16(type);
3328 	m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
3329 	m->hdr.front_len = cpu_to_le32(front_len);
3330 
3331 	INIT_LIST_HEAD(&m->list_head);
3332 	kref_init(&m->kref);
3333 
3334 	/* front */
3335 	if (front_len) {
3336 		m->front.iov_base = ceph_kvmalloc(front_len, flags);
3337 		if (m->front.iov_base == NULL) {
3338 			dout("ceph_msg_new can't allocate %d bytes\n",
3339 			     front_len);
3340 			goto out2;
3341 		}
3342 	} else {
3343 		m->front.iov_base = NULL;
3344 	}
3345 	m->front_alloc_len = m->front.iov_len = front_len;
3346 
3347 	if (max_data_items) {
3348 		m->data = kmalloc_array(max_data_items, sizeof(*m->data),
3349 					flags);
3350 		if (!m->data)
3351 			goto out2;
3352 
3353 		m->max_data_items = max_data_items;
3354 	}
3355 
3356 	dout("ceph_msg_new %p front %d\n", m, front_len);
3357 	return m;
3358 
3359 out2:
3360 	ceph_msg_put(m);
3361 out:
3362 	if (!can_fail) {
3363 		pr_err("msg_new can't create type %d front %d\n", type,
3364 		       front_len);
3365 		WARN_ON(1);
3366 	} else {
3367 		dout("msg_new can't create type %d front %d\n", type,
3368 		     front_len);
3369 	}
3370 	return NULL;
3371 }
3372 EXPORT_SYMBOL(ceph_msg_new2);
3373 
3374 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
3375 			      bool can_fail)
3376 {
3377 	return ceph_msg_new2(type, front_len, 0, flags, can_fail);
3378 }
3379 EXPORT_SYMBOL(ceph_msg_new);
3380 
3381 /*
3382  * Allocate "middle" portion of a message, if it is needed and wasn't
3383  * allocated by alloc_msg.  This allows us to read a small fixed-size
3384  * per-type header in the front and then gracefully fail (i.e.,
3385  * propagate the error to the caller based on info in the front) when
3386  * the middle is too large.
3387  */
3388 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
3389 {
3390 	int type = le16_to_cpu(msg->hdr.type);
3391 	int middle_len = le32_to_cpu(msg->hdr.middle_len);
3392 
3393 	dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
3394 	     ceph_msg_type_name(type), middle_len);
3395 	BUG_ON(!middle_len);
3396 	BUG_ON(msg->middle);
3397 
3398 	msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
3399 	if (!msg->middle)
3400 		return -ENOMEM;
3401 	return 0;
3402 }
3403 
3404 /*
3405  * Allocate a message for receiving an incoming message on a
3406  * connection, and save the result in con->in_msg.  Uses the
3407  * connection's private alloc_msg op if available.
3408  *
3409  * Returns 0 on success, or a negative error code.
3410  *
3411  * On success, if we set *skip = 1:
3412  *  - the next message should be skipped and ignored.
3413  *  - con->in_msg == NULL
3414  * or if we set *skip = 0:
3415  *  - con->in_msg is non-null.
3416  * On error (ENOMEM, EAGAIN, ...),
3417  *  - con->in_msg == NULL
3418  */
3419 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
3420 {
3421 	struct ceph_msg_header *hdr = &con->in_hdr;
3422 	int middle_len = le32_to_cpu(hdr->middle_len);
3423 	struct ceph_msg *msg;
3424 	int ret = 0;
3425 
3426 	BUG_ON(con->in_msg != NULL);
3427 	BUG_ON(!con->ops->alloc_msg);
3428 
3429 	mutex_unlock(&con->mutex);
3430 	msg = con->ops->alloc_msg(con, hdr, skip);
3431 	mutex_lock(&con->mutex);
3432 	if (con->state != CON_STATE_OPEN) {
3433 		if (msg)
3434 			ceph_msg_put(msg);
3435 		return -EAGAIN;
3436 	}
3437 	if (msg) {
3438 		BUG_ON(*skip);
3439 		msg_con_set(msg, con);
3440 		con->in_msg = msg;
3441 	} else {
3442 		/*
3443 		 * Null message pointer means either we should skip
3444 		 * this message or we couldn't allocate memory.  The
3445 		 * former is not an error.
3446 		 */
3447 		if (*skip)
3448 			return 0;
3449 
3450 		con->error_msg = "error allocating memory for incoming message";
3451 		return -ENOMEM;
3452 	}
3453 	memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
3454 
3455 	if (middle_len && !con->in_msg->middle) {
3456 		ret = ceph_alloc_middle(con, con->in_msg);
3457 		if (ret < 0) {
3458 			ceph_msg_put(con->in_msg);
3459 			con->in_msg = NULL;
3460 		}
3461 	}
3462 
3463 	return ret;
3464 }
3465 
3466 
3467 /*
3468  * Free a generically kmalloc'd message.
3469  */
3470 static void ceph_msg_free(struct ceph_msg *m)
3471 {
3472 	dout("%s %p\n", __func__, m);
3473 	kvfree(m->front.iov_base);
3474 	kfree(m->data);
3475 	kmem_cache_free(ceph_msg_cache, m);
3476 }
3477 
3478 static void ceph_msg_release(struct kref *kref)
3479 {
3480 	struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
3481 	int i;
3482 
3483 	dout("%s %p\n", __func__, m);
3484 	WARN_ON(!list_empty(&m->list_head));
3485 
3486 	msg_con_set(m, NULL);
3487 
3488 	/* drop middle, data, if any */
3489 	if (m->middle) {
3490 		ceph_buffer_put(m->middle);
3491 		m->middle = NULL;
3492 	}
3493 
3494 	for (i = 0; i < m->num_data_items; i++)
3495 		ceph_msg_data_destroy(&m->data[i]);
3496 
3497 	if (m->pool)
3498 		ceph_msgpool_put(m->pool, m);
3499 	else
3500 		ceph_msg_free(m);
3501 }
3502 
3503 struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
3504 {
3505 	dout("%s %p (was %d)\n", __func__, msg,
3506 	     kref_read(&msg->kref));
3507 	kref_get(&msg->kref);
3508 	return msg;
3509 }
3510 EXPORT_SYMBOL(ceph_msg_get);
3511 
3512 void ceph_msg_put(struct ceph_msg *msg)
3513 {
3514 	dout("%s %p (was %d)\n", __func__, msg,
3515 	     kref_read(&msg->kref));
3516 	kref_put(&msg->kref, ceph_msg_release);
3517 }
3518 EXPORT_SYMBOL(ceph_msg_put);
3519 
3520 void ceph_msg_dump(struct ceph_msg *msg)
3521 {
3522 	pr_debug("msg_dump %p (front_alloc_len %d length %zd)\n", msg,
3523 		 msg->front_alloc_len, msg->data_length);
3524 	print_hex_dump(KERN_DEBUG, "header: ",
3525 		       DUMP_PREFIX_OFFSET, 16, 1,
3526 		       &msg->hdr, sizeof(msg->hdr), true);
3527 	print_hex_dump(KERN_DEBUG, " front: ",
3528 		       DUMP_PREFIX_OFFSET, 16, 1,
3529 		       msg->front.iov_base, msg->front.iov_len, true);
3530 	if (msg->middle)
3531 		print_hex_dump(KERN_DEBUG, "middle: ",
3532 			       DUMP_PREFIX_OFFSET, 16, 1,
3533 			       msg->middle->vec.iov_base,
3534 			       msg->middle->vec.iov_len, true);
3535 	print_hex_dump(KERN_DEBUG, "footer: ",
3536 		       DUMP_PREFIX_OFFSET, 16, 1,
3537 		       &msg->footer, sizeof(msg->footer), true);
3538 }
3539 EXPORT_SYMBOL(ceph_msg_dump);
3540