Merge branch 'akpm' (patches from Andrew)
[muen/linux.git] / net / ceph / messenger.c
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, bool 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 /*
564  * @more: either or both of MSG_MORE and MSG_SENDPAGE_NOTLAST
565  */
566 static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
567                              int offset, size_t size, int more)
568 {
569         ssize_t (*sendpage)(struct socket *sock, struct page *page,
570                             int offset, size_t size, int flags);
571         int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more;
572         int ret;
573
574         /*
575          * sendpage cannot properly handle pages with page_count == 0,
576          * we need to fall back to sendmsg if that's the case.
577          *
578          * Same goes for slab pages: skb_can_coalesce() allows
579          * coalescing neighboring slab objects into a single frag which
580          * triggers one of hardened usercopy checks.
581          */
582         if (page_count(page) >= 1 && !PageSlab(page))
583                 sendpage = sock->ops->sendpage;
584         else
585                 sendpage = sock_no_sendpage;
586
587         ret = sendpage(sock, page, offset, size, flags);
588         if (ret == -EAGAIN)
589                 ret = 0;
590
591         return ret;
592 }
593
594 /*
595  * Shutdown/close the socket for the given connection.
596  */
597 static int con_close_socket(struct ceph_connection *con)
598 {
599         int rc = 0;
600
601         dout("con_close_socket on %p sock %p\n", con, con->sock);
602         if (con->sock) {
603                 rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
604                 sock_release(con->sock);
605                 con->sock = NULL;
606         }
607
608         /*
609          * Forcibly clear the SOCK_CLOSED flag.  It gets set
610          * independent of the connection mutex, and we could have
611          * received a socket close event before we had the chance to
612          * shut the socket down.
613          */
614         con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
615
616         con_sock_state_closed(con);
617         return rc;
618 }
619
620 /*
621  * Reset a connection.  Discard all incoming and outgoing messages
622  * and clear *_seq state.
623  */
624 static void ceph_msg_remove(struct ceph_msg *msg)
625 {
626         list_del_init(&msg->list_head);
627
628         ceph_msg_put(msg);
629 }
630 static void ceph_msg_remove_list(struct list_head *head)
631 {
632         while (!list_empty(head)) {
633                 struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
634                                                         list_head);
635                 ceph_msg_remove(msg);
636         }
637 }
638
639 static void reset_connection(struct ceph_connection *con)
640 {
641         /* reset connection, out_queue, msg_ and connect_seq */
642         /* discard existing out_queue and msg_seq */
643         dout("reset_connection %p\n", con);
644         ceph_msg_remove_list(&con->out_queue);
645         ceph_msg_remove_list(&con->out_sent);
646
647         if (con->in_msg) {
648                 BUG_ON(con->in_msg->con != con);
649                 ceph_msg_put(con->in_msg);
650                 con->in_msg = NULL;
651         }
652
653         con->connect_seq = 0;
654         con->out_seq = 0;
655         if (con->out_msg) {
656                 BUG_ON(con->out_msg->con != con);
657                 ceph_msg_put(con->out_msg);
658                 con->out_msg = NULL;
659         }
660         con->in_seq = 0;
661         con->in_seq_acked = 0;
662
663         con->out_skip = 0;
664 }
665
666 /*
667  * mark a peer down.  drop any open connections.
668  */
669 void ceph_con_close(struct ceph_connection *con)
670 {
671         mutex_lock(&con->mutex);
672         dout("con_close %p peer %s\n", con,
673              ceph_pr_addr(&con->peer_addr.in_addr));
674         con->state = CON_STATE_CLOSED;
675
676         con_flag_clear(con, CON_FLAG_LOSSYTX);  /* so we retry next connect */
677         con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
678         con_flag_clear(con, CON_FLAG_WRITE_PENDING);
679         con_flag_clear(con, CON_FLAG_BACKOFF);
680
681         reset_connection(con);
682         con->peer_global_seq = 0;
683         cancel_con(con);
684         con_close_socket(con);
685         mutex_unlock(&con->mutex);
686 }
687 EXPORT_SYMBOL(ceph_con_close);
688
689 /*
690  * Reopen a closed connection, with a new peer address.
691  */
692 void ceph_con_open(struct ceph_connection *con,
693                    __u8 entity_type, __u64 entity_num,
694                    struct ceph_entity_addr *addr)
695 {
696         mutex_lock(&con->mutex);
697         dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
698
699         WARN_ON(con->state != CON_STATE_CLOSED);
700         con->state = CON_STATE_PREOPEN;
701
702         con->peer_name.type = (__u8) entity_type;
703         con->peer_name.num = cpu_to_le64(entity_num);
704
705         memcpy(&con->peer_addr, addr, sizeof(*addr));
706         con->delay = 0;      /* reset backoff memory */
707         mutex_unlock(&con->mutex);
708         queue_con(con);
709 }
710 EXPORT_SYMBOL(ceph_con_open);
711
712 /*
713  * return true if this connection ever successfully opened
714  */
715 bool ceph_con_opened(struct ceph_connection *con)
716 {
717         return con->connect_seq > 0;
718 }
719
720 /*
721  * initialize a new connection.
722  */
723 void ceph_con_init(struct ceph_connection *con, void *private,
724         const struct ceph_connection_operations *ops,
725         struct ceph_messenger *msgr)
726 {
727         dout("con_init %p\n", con);
728         memset(con, 0, sizeof(*con));
729         con->private = private;
730         con->ops = ops;
731         con->msgr = msgr;
732
733         con_sock_state_init(con);
734
735         mutex_init(&con->mutex);
736         INIT_LIST_HEAD(&con->out_queue);
737         INIT_LIST_HEAD(&con->out_sent);
738         INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
739
740         con->state = CON_STATE_CLOSED;
741 }
742 EXPORT_SYMBOL(ceph_con_init);
743
744
745 /*
746  * We maintain a global counter to order connection attempts.  Get
747  * a unique seq greater than @gt.
748  */
749 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
750 {
751         u32 ret;
752
753         spin_lock(&msgr->global_seq_lock);
754         if (msgr->global_seq < gt)
755                 msgr->global_seq = gt;
756         ret = ++msgr->global_seq;
757         spin_unlock(&msgr->global_seq_lock);
758         return ret;
759 }
760
761 static void con_out_kvec_reset(struct ceph_connection *con)
762 {
763         BUG_ON(con->out_skip);
764
765         con->out_kvec_left = 0;
766         con->out_kvec_bytes = 0;
767         con->out_kvec_cur = &con->out_kvec[0];
768 }
769
770 static void con_out_kvec_add(struct ceph_connection *con,
771                                 size_t size, void *data)
772 {
773         int index = con->out_kvec_left;
774
775         BUG_ON(con->out_skip);
776         BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
777
778         con->out_kvec[index].iov_len = size;
779         con->out_kvec[index].iov_base = data;
780         con->out_kvec_left++;
781         con->out_kvec_bytes += size;
782 }
783
784 /*
785  * Chop off a kvec from the end.  Return residual number of bytes for
786  * that kvec, i.e. how many bytes would have been written if the kvec
787  * hadn't been nuked.
788  */
789 static int con_out_kvec_skip(struct ceph_connection *con)
790 {
791         int off = con->out_kvec_cur - con->out_kvec;
792         int skip = 0;
793
794         if (con->out_kvec_bytes > 0) {
795                 skip = con->out_kvec[off + con->out_kvec_left - 1].iov_len;
796                 BUG_ON(con->out_kvec_bytes < skip);
797                 BUG_ON(!con->out_kvec_left);
798                 con->out_kvec_bytes -= skip;
799                 con->out_kvec_left--;
800         }
801
802         return skip;
803 }
804
805 #ifdef CONFIG_BLOCK
806
807 /*
808  * For a bio data item, a piece is whatever remains of the next
809  * entry in the current bio iovec, or the first entry in the next
810  * bio in the list.
811  */
812 static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
813                                         size_t length)
814 {
815         struct ceph_msg_data *data = cursor->data;
816         struct ceph_bio_iter *it = &cursor->bio_iter;
817
818         cursor->resid = min_t(size_t, length, data->bio_length);
819         *it = data->bio_pos;
820         if (cursor->resid < it->iter.bi_size)
821                 it->iter.bi_size = cursor->resid;
822
823         BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
824         cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
825 }
826
827 static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
828                                                 size_t *page_offset,
829                                                 size_t *length)
830 {
831         struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
832                                            cursor->bio_iter.iter);
833
834         *page_offset = bv.bv_offset;
835         *length = bv.bv_len;
836         return bv.bv_page;
837 }
838
839 static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
840                                         size_t bytes)
841 {
842         struct ceph_bio_iter *it = &cursor->bio_iter;
843         struct page *page = bio_iter_page(it->bio, it->iter);
844
845         BUG_ON(bytes > cursor->resid);
846         BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
847         cursor->resid -= bytes;
848         bio_advance_iter(it->bio, &it->iter, bytes);
849
850         if (!cursor->resid) {
851                 BUG_ON(!cursor->last_piece);
852                 return false;   /* no more data */
853         }
854
855         if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&
856                        page == bio_iter_page(it->bio, it->iter)))
857                 return false;   /* more bytes to process in this segment */
858
859         if (!it->iter.bi_size) {
860                 it->bio = it->bio->bi_next;
861                 it->iter = it->bio->bi_iter;
862                 if (cursor->resid < it->iter.bi_size)
863                         it->iter.bi_size = cursor->resid;
864         }
865
866         BUG_ON(cursor->last_piece);
867         BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
868         cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
869         return true;
870 }
871 #endif /* CONFIG_BLOCK */
872
873 static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
874                                         size_t length)
875 {
876         struct ceph_msg_data *data = cursor->data;
877         struct bio_vec *bvecs = data->bvec_pos.bvecs;
878
879         cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
880         cursor->bvec_iter = data->bvec_pos.iter;
881         cursor->bvec_iter.bi_size = cursor->resid;
882
883         BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
884         cursor->last_piece =
885             cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
886 }
887
888 static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
889                                                 size_t *page_offset,
890                                                 size_t *length)
891 {
892         struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
893                                            cursor->bvec_iter);
894
895         *page_offset = bv.bv_offset;
896         *length = bv.bv_len;
897         return bv.bv_page;
898 }
899
900 static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
901                                         size_t bytes)
902 {
903         struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
904         struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter);
905
906         BUG_ON(bytes > cursor->resid);
907         BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
908         cursor->resid -= bytes;
909         bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
910
911         if (!cursor->resid) {
912                 BUG_ON(!cursor->last_piece);
913                 return false;   /* no more data */
914         }
915
916         if (!bytes || (cursor->bvec_iter.bi_bvec_done &&
917                        page == bvec_iter_page(bvecs, cursor->bvec_iter)))
918                 return false;   /* more bytes to process in this segment */
919
920         BUG_ON(cursor->last_piece);
921         BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
922         cursor->last_piece =
923             cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
924         return true;
925 }
926
927 /*
928  * For a page array, a piece comes from the first page in the array
929  * that has not already been fully consumed.
930  */
931 static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
932                                         size_t length)
933 {
934         struct ceph_msg_data *data = cursor->data;
935         int page_count;
936
937         BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
938
939         BUG_ON(!data->pages);
940         BUG_ON(!data->length);
941
942         cursor->resid = min(length, data->length);
943         page_count = calc_pages_for(data->alignment, (u64)data->length);
944         cursor->page_offset = data->alignment & ~PAGE_MASK;
945         cursor->page_index = 0;
946         BUG_ON(page_count > (int)USHRT_MAX);
947         cursor->page_count = (unsigned short)page_count;
948         BUG_ON(length > SIZE_MAX - cursor->page_offset);
949         cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
950 }
951
952 static struct page *
953 ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
954                                         size_t *page_offset, size_t *length)
955 {
956         struct ceph_msg_data *data = cursor->data;
957
958         BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
959
960         BUG_ON(cursor->page_index >= cursor->page_count);
961         BUG_ON(cursor->page_offset >= PAGE_SIZE);
962
963         *page_offset = cursor->page_offset;
964         if (cursor->last_piece)
965                 *length = cursor->resid;
966         else
967                 *length = PAGE_SIZE - *page_offset;
968
969         return data->pages[cursor->page_index];
970 }
971
972 static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
973                                                 size_t bytes)
974 {
975         BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
976
977         BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
978
979         /* Advance the cursor page offset */
980
981         cursor->resid -= bytes;
982         cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
983         if (!bytes || cursor->page_offset)
984                 return false;   /* more bytes to process in the current page */
985
986         if (!cursor->resid)
987                 return false;   /* no more data */
988
989         /* Move on to the next page; offset is already at 0 */
990
991         BUG_ON(cursor->page_index >= cursor->page_count);
992         cursor->page_index++;
993         cursor->last_piece = cursor->resid <= PAGE_SIZE;
994
995         return true;
996 }
997
998 /*
999  * For a pagelist, a piece is whatever remains to be consumed in the
1000  * first page in the list, or the front of the next page.
1001  */
1002 static void
1003 ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
1004                                         size_t length)
1005 {
1006         struct ceph_msg_data *data = cursor->data;
1007         struct ceph_pagelist *pagelist;
1008         struct page *page;
1009
1010         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1011
1012         pagelist = data->pagelist;
1013         BUG_ON(!pagelist);
1014
1015         if (!length)
1016                 return;         /* pagelist can be assigned but empty */
1017
1018         BUG_ON(list_empty(&pagelist->head));
1019         page = list_first_entry(&pagelist->head, struct page, lru);
1020
1021         cursor->resid = min(length, pagelist->length);
1022         cursor->page = page;
1023         cursor->offset = 0;
1024         cursor->last_piece = cursor->resid <= PAGE_SIZE;
1025 }
1026
1027 static struct page *
1028 ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
1029                                 size_t *page_offset, size_t *length)
1030 {
1031         struct ceph_msg_data *data = cursor->data;
1032         struct ceph_pagelist *pagelist;
1033
1034         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1035
1036         pagelist = data->pagelist;
1037         BUG_ON(!pagelist);
1038
1039         BUG_ON(!cursor->page);
1040         BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1041
1042         /* offset of first page in pagelist is always 0 */
1043         *page_offset = cursor->offset & ~PAGE_MASK;
1044         if (cursor->last_piece)
1045                 *length = cursor->resid;
1046         else
1047                 *length = PAGE_SIZE - *page_offset;
1048
1049         return cursor->page;
1050 }
1051
1052 static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
1053                                                 size_t bytes)
1054 {
1055         struct ceph_msg_data *data = cursor->data;
1056         struct ceph_pagelist *pagelist;
1057
1058         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1059
1060         pagelist = data->pagelist;
1061         BUG_ON(!pagelist);
1062
1063         BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1064         BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
1065
1066         /* Advance the cursor offset */
1067
1068         cursor->resid -= bytes;
1069         cursor->offset += bytes;
1070         /* offset of first page in pagelist is always 0 */
1071         if (!bytes || cursor->offset & ~PAGE_MASK)
1072                 return false;   /* more bytes to process in the current page */
1073
1074         if (!cursor->resid)
1075                 return false;   /* no more data */
1076
1077         /* Move on to the next page */
1078
1079         BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
1080         cursor->page = list_next_entry(cursor->page, lru);
1081         cursor->last_piece = cursor->resid <= PAGE_SIZE;
1082
1083         return true;
1084 }
1085
1086 /*
1087  * Message data is handled (sent or received) in pieces, where each
1088  * piece resides on a single page.  The network layer might not
1089  * consume an entire piece at once.  A data item's cursor keeps
1090  * track of which piece is next to process and how much remains to
1091  * be processed in that piece.  It also tracks whether the current
1092  * piece is the last one in the data item.
1093  */
1094 static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
1095 {
1096         size_t length = cursor->total_resid;
1097
1098         switch (cursor->data->type) {
1099         case CEPH_MSG_DATA_PAGELIST:
1100                 ceph_msg_data_pagelist_cursor_init(cursor, length);
1101                 break;
1102         case CEPH_MSG_DATA_PAGES:
1103                 ceph_msg_data_pages_cursor_init(cursor, length);
1104                 break;
1105 #ifdef CONFIG_BLOCK
1106         case CEPH_MSG_DATA_BIO:
1107                 ceph_msg_data_bio_cursor_init(cursor, length);
1108                 break;
1109 #endif /* CONFIG_BLOCK */
1110         case CEPH_MSG_DATA_BVECS:
1111                 ceph_msg_data_bvecs_cursor_init(cursor, length);
1112                 break;
1113         case CEPH_MSG_DATA_NONE:
1114         default:
1115                 /* BUG(); */
1116                 break;
1117         }
1118         cursor->need_crc = true;
1119 }
1120
1121 static void ceph_msg_data_cursor_init(struct ceph_msg *msg, size_t length)
1122 {
1123         struct ceph_msg_data_cursor *cursor = &msg->cursor;
1124
1125         BUG_ON(!length);
1126         BUG_ON(length > msg->data_length);
1127         BUG_ON(!msg->num_data_items);
1128
1129         cursor->total_resid = length;
1130         cursor->data = msg->data;
1131
1132         __ceph_msg_data_cursor_init(cursor);
1133 }
1134
1135 /*
1136  * Return the page containing the next piece to process for a given
1137  * data item, and supply the page offset and length of that piece.
1138  * Indicate whether this is the last piece in this data item.
1139  */
1140 static struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
1141                                         size_t *page_offset, size_t *length,
1142                                         bool *last_piece)
1143 {
1144         struct page *page;
1145
1146         switch (cursor->data->type) {
1147         case CEPH_MSG_DATA_PAGELIST:
1148                 page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
1149                 break;
1150         case CEPH_MSG_DATA_PAGES:
1151                 page = ceph_msg_data_pages_next(cursor, page_offset, length);
1152                 break;
1153 #ifdef CONFIG_BLOCK
1154         case CEPH_MSG_DATA_BIO:
1155                 page = ceph_msg_data_bio_next(cursor, page_offset, length);
1156                 break;
1157 #endif /* CONFIG_BLOCK */
1158         case CEPH_MSG_DATA_BVECS:
1159                 page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
1160                 break;
1161         case CEPH_MSG_DATA_NONE:
1162         default:
1163                 page = NULL;
1164                 break;
1165         }
1166
1167         BUG_ON(!page);
1168         BUG_ON(*page_offset + *length > PAGE_SIZE);
1169         BUG_ON(!*length);
1170         BUG_ON(*length > cursor->resid);
1171         if (last_piece)
1172                 *last_piece = cursor->last_piece;
1173
1174         return page;
1175 }
1176
1177 /*
1178  * Returns true if the result moves the cursor on to the next piece
1179  * of the data item.
1180  */
1181 static void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor,
1182                                   size_t bytes)
1183 {
1184         bool new_piece;
1185
1186         BUG_ON(bytes > cursor->resid);
1187         switch (cursor->data->type) {
1188         case CEPH_MSG_DATA_PAGELIST:
1189                 new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
1190                 break;
1191         case CEPH_MSG_DATA_PAGES:
1192                 new_piece = ceph_msg_data_pages_advance(cursor, bytes);
1193                 break;
1194 #ifdef CONFIG_BLOCK
1195         case CEPH_MSG_DATA_BIO:
1196                 new_piece = ceph_msg_data_bio_advance(cursor, bytes);
1197                 break;
1198 #endif /* CONFIG_BLOCK */
1199         case CEPH_MSG_DATA_BVECS:
1200                 new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
1201                 break;
1202         case CEPH_MSG_DATA_NONE:
1203         default:
1204                 BUG();
1205                 break;
1206         }
1207         cursor->total_resid -= bytes;
1208
1209         if (!cursor->resid && cursor->total_resid) {
1210                 WARN_ON(!cursor->last_piece);
1211                 cursor->data++;
1212                 __ceph_msg_data_cursor_init(cursor);
1213                 new_piece = true;
1214         }
1215         cursor->need_crc = new_piece;
1216 }
1217
1218 static size_t sizeof_footer(struct ceph_connection *con)
1219 {
1220         return (con->peer_features & CEPH_FEATURE_MSG_AUTH) ?
1221             sizeof(struct ceph_msg_footer) :
1222             sizeof(struct ceph_msg_footer_old);
1223 }
1224
1225 static void prepare_message_data(struct ceph_msg *msg, u32 data_len)
1226 {
1227         /* Initialize data cursor */
1228
1229         ceph_msg_data_cursor_init(msg, (size_t)data_len);
1230 }
1231
1232 /*
1233  * Prepare footer for currently outgoing message, and finish things
1234  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
1235  */
1236 static void prepare_write_message_footer(struct ceph_connection *con)
1237 {
1238         struct ceph_msg *m = con->out_msg;
1239
1240         m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
1241
1242         dout("prepare_write_message_footer %p\n", con);
1243         con_out_kvec_add(con, sizeof_footer(con), &m->footer);
1244         if (con->peer_features & CEPH_FEATURE_MSG_AUTH) {
1245                 if (con->ops->sign_message)
1246                         con->ops->sign_message(m);
1247                 else
1248                         m->footer.sig = 0;
1249         } else {
1250                 m->old_footer.flags = m->footer.flags;
1251         }
1252         con->out_more = m->more_to_follow;
1253         con->out_msg_done = true;
1254 }
1255
1256 /*
1257  * Prepare headers for the next outgoing message.
1258  */
1259 static void prepare_write_message(struct ceph_connection *con)
1260 {
1261         struct ceph_msg *m;
1262         u32 crc;
1263
1264         con_out_kvec_reset(con);
1265         con->out_msg_done = false;
1266
1267         /* Sneak an ack in there first?  If we can get it into the same
1268          * TCP packet that's a good thing. */
1269         if (con->in_seq > con->in_seq_acked) {
1270                 con->in_seq_acked = con->in_seq;
1271                 con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1272                 con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1273                 con_out_kvec_add(con, sizeof (con->out_temp_ack),
1274                         &con->out_temp_ack);
1275         }
1276
1277         BUG_ON(list_empty(&con->out_queue));
1278         m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
1279         con->out_msg = m;
1280         BUG_ON(m->con != con);
1281
1282         /* put message on sent list */
1283         ceph_msg_get(m);
1284         list_move_tail(&m->list_head, &con->out_sent);
1285
1286         /*
1287          * only assign outgoing seq # if we haven't sent this message
1288          * yet.  if it is requeued, resend with it's original seq.
1289          */
1290         if (m->needs_out_seq) {
1291                 m->hdr.seq = cpu_to_le64(++con->out_seq);
1292                 m->needs_out_seq = false;
1293
1294                 if (con->ops->reencode_message)
1295                         con->ops->reencode_message(m);
1296         }
1297
1298         dout("prepare_write_message %p seq %lld type %d len %d+%d+%zd\n",
1299              m, con->out_seq, le16_to_cpu(m->hdr.type),
1300              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
1301              m->data_length);
1302         WARN_ON(m->front.iov_len != le32_to_cpu(m->hdr.front_len));
1303         WARN_ON(m->data_length != le32_to_cpu(m->hdr.data_len));
1304
1305         /* tag + hdr + front + middle */
1306         con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
1307         con_out_kvec_add(con, sizeof(con->out_hdr), &con->out_hdr);
1308         con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
1309
1310         if (m->middle)
1311                 con_out_kvec_add(con, m->middle->vec.iov_len,
1312                         m->middle->vec.iov_base);
1313
1314         /* fill in hdr crc and finalize hdr */
1315         crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
1316         con->out_msg->hdr.crc = cpu_to_le32(crc);
1317         memcpy(&con->out_hdr, &con->out_msg->hdr, sizeof(con->out_hdr));
1318
1319         /* fill in front and middle crc, footer */
1320         crc = crc32c(0, m->front.iov_base, m->front.iov_len);
1321         con->out_msg->footer.front_crc = cpu_to_le32(crc);
1322         if (m->middle) {
1323                 crc = crc32c(0, m->middle->vec.iov_base,
1324                                 m->middle->vec.iov_len);
1325                 con->out_msg->footer.middle_crc = cpu_to_le32(crc);
1326         } else
1327                 con->out_msg->footer.middle_crc = 0;
1328         dout("%s front_crc %u middle_crc %u\n", __func__,
1329              le32_to_cpu(con->out_msg->footer.front_crc),
1330              le32_to_cpu(con->out_msg->footer.middle_crc));
1331         con->out_msg->footer.flags = 0;
1332
1333         /* is there a data payload? */
1334         con->out_msg->footer.data_crc = 0;
1335         if (m->data_length) {
1336                 prepare_message_data(con->out_msg, m->data_length);
1337                 con->out_more = 1;  /* data + footer will follow */
1338         } else {
1339                 /* no, queue up footer too and be done */
1340                 prepare_write_message_footer(con);
1341         }
1342
1343         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1344 }
1345
1346 /*
1347  * Prepare an ack.
1348  */
1349 static void prepare_write_ack(struct ceph_connection *con)
1350 {
1351         dout("prepare_write_ack %p %llu -> %llu\n", con,
1352              con->in_seq_acked, con->in_seq);
1353         con->in_seq_acked = con->in_seq;
1354
1355         con_out_kvec_reset(con);
1356
1357         con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1358
1359         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1360         con_out_kvec_add(con, sizeof (con->out_temp_ack),
1361                                 &con->out_temp_ack);
1362
1363         con->out_more = 1;  /* more will follow.. eventually.. */
1364         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1365 }
1366
1367 /*
1368  * Prepare to share the seq during handshake
1369  */
1370 static void prepare_write_seq(struct ceph_connection *con)
1371 {
1372         dout("prepare_write_seq %p %llu -> %llu\n", con,
1373              con->in_seq_acked, con->in_seq);
1374         con->in_seq_acked = con->in_seq;
1375
1376         con_out_kvec_reset(con);
1377
1378         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1379         con_out_kvec_add(con, sizeof (con->out_temp_ack),
1380                          &con->out_temp_ack);
1381
1382         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1383 }
1384
1385 /*
1386  * Prepare to write keepalive byte.
1387  */
1388 static void prepare_write_keepalive(struct ceph_connection *con)
1389 {
1390         dout("prepare_write_keepalive %p\n", con);
1391         con_out_kvec_reset(con);
1392         if (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2) {
1393                 struct timespec64 now;
1394
1395                 ktime_get_real_ts64(&now);
1396                 con_out_kvec_add(con, sizeof(tag_keepalive2), &tag_keepalive2);
1397                 ceph_encode_timespec64(&con->out_temp_keepalive2, &now);
1398                 con_out_kvec_add(con, sizeof(con->out_temp_keepalive2),
1399                                  &con->out_temp_keepalive2);
1400         } else {
1401                 con_out_kvec_add(con, sizeof(tag_keepalive), &tag_keepalive);
1402         }
1403         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1404 }
1405
1406 /*
1407  * Connection negotiation.
1408  */
1409
1410 static int get_connect_authorizer(struct ceph_connection *con)
1411 {
1412         struct ceph_auth_handshake *auth;
1413         int auth_proto;
1414
1415         if (!con->ops->get_authorizer) {
1416                 con->auth = NULL;
1417                 con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
1418                 con->out_connect.authorizer_len = 0;
1419                 return 0;
1420         }
1421
1422         auth = con->ops->get_authorizer(con, &auth_proto, con->auth_retry);
1423         if (IS_ERR(auth))
1424                 return PTR_ERR(auth);
1425
1426         con->auth = auth;
1427         con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
1428         con->out_connect.authorizer_len = cpu_to_le32(auth->authorizer_buf_len);
1429         return 0;
1430 }
1431
1432 /*
1433  * We connected to a peer and are saying hello.
1434  */
1435 static void prepare_write_banner(struct ceph_connection *con)
1436 {
1437         con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
1438         con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
1439                                         &con->msgr->my_enc_addr);
1440
1441         con->out_more = 0;
1442         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1443 }
1444
1445 static void __prepare_write_connect(struct ceph_connection *con)
1446 {
1447         con_out_kvec_add(con, sizeof(con->out_connect), &con->out_connect);
1448         if (con->auth)
1449                 con_out_kvec_add(con, con->auth->authorizer_buf_len,
1450                                  con->auth->authorizer_buf);
1451
1452         con->out_more = 0;
1453         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1454 }
1455
1456 static int prepare_write_connect(struct ceph_connection *con)
1457 {
1458         unsigned int global_seq = get_global_seq(con->msgr, 0);
1459         int proto;
1460         int ret;
1461
1462         switch (con->peer_name.type) {
1463         case CEPH_ENTITY_TYPE_MON:
1464                 proto = CEPH_MONC_PROTOCOL;
1465                 break;
1466         case CEPH_ENTITY_TYPE_OSD:
1467                 proto = CEPH_OSDC_PROTOCOL;
1468                 break;
1469         case CEPH_ENTITY_TYPE_MDS:
1470                 proto = CEPH_MDSC_PROTOCOL;
1471                 break;
1472         default:
1473                 BUG();
1474         }
1475
1476         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
1477              con->connect_seq, global_seq, proto);
1478
1479         con->out_connect.features =
1480             cpu_to_le64(from_msgr(con->msgr)->supported_features);
1481         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
1482         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
1483         con->out_connect.global_seq = cpu_to_le32(global_seq);
1484         con->out_connect.protocol_version = cpu_to_le32(proto);
1485         con->out_connect.flags = 0;
1486
1487         ret = get_connect_authorizer(con);
1488         if (ret)
1489                 return ret;
1490
1491         __prepare_write_connect(con);
1492         return 0;
1493 }
1494
1495 /*
1496  * write as much of pending kvecs to the socket as we can.
1497  *  1 -> done
1498  *  0 -> socket full, but more to do
1499  * <0 -> error
1500  */
1501 static int write_partial_kvec(struct ceph_connection *con)
1502 {
1503         int ret;
1504
1505         dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
1506         while (con->out_kvec_bytes > 0) {
1507                 ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
1508                                        con->out_kvec_left, con->out_kvec_bytes,
1509                                        con->out_more);
1510                 if (ret <= 0)
1511                         goto out;
1512                 con->out_kvec_bytes -= ret;
1513                 if (con->out_kvec_bytes == 0)
1514                         break;            /* done */
1515
1516                 /* account for full iov entries consumed */
1517                 while (ret >= con->out_kvec_cur->iov_len) {
1518                         BUG_ON(!con->out_kvec_left);
1519                         ret -= con->out_kvec_cur->iov_len;
1520                         con->out_kvec_cur++;
1521                         con->out_kvec_left--;
1522                 }
1523                 /* and for a partially-consumed entry */
1524                 if (ret) {
1525                         con->out_kvec_cur->iov_len -= ret;
1526                         con->out_kvec_cur->iov_base += ret;
1527                 }
1528         }
1529         con->out_kvec_left = 0;
1530         ret = 1;
1531 out:
1532         dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
1533              con->out_kvec_bytes, con->out_kvec_left, ret);
1534         return ret;  /* done! */
1535 }
1536
1537 static u32 ceph_crc32c_page(u32 crc, struct page *page,
1538                                 unsigned int page_offset,
1539                                 unsigned int length)
1540 {
1541         char *kaddr;
1542
1543         kaddr = kmap(page);
1544         BUG_ON(kaddr == NULL);
1545         crc = crc32c(crc, kaddr + page_offset, length);
1546         kunmap(page);
1547
1548         return crc;
1549 }
1550 /*
1551  * Write as much message data payload as we can.  If we finish, queue
1552  * up the footer.
1553  *  1 -> done, footer is now queued in out_kvec[].
1554  *  0 -> socket full, but more to do
1555  * <0 -> error
1556  */
1557 static int write_partial_message_data(struct ceph_connection *con)
1558 {
1559         struct ceph_msg *msg = con->out_msg;
1560         struct ceph_msg_data_cursor *cursor = &msg->cursor;
1561         bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
1562         int more = MSG_MORE | MSG_SENDPAGE_NOTLAST;
1563         u32 crc;
1564
1565         dout("%s %p msg %p\n", __func__, con, msg);
1566
1567         if (!msg->num_data_items)
1568                 return -EINVAL;
1569
1570         /*
1571          * Iterate through each page that contains data to be
1572          * written, and send as much as possible for each.
1573          *
1574          * If we are calculating the data crc (the default), we will
1575          * need to map the page.  If we have no pages, they have
1576          * been revoked, so use the zero page.
1577          */
1578         crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
1579         while (cursor->total_resid) {
1580                 struct page *page;
1581                 size_t page_offset;
1582                 size_t length;
1583                 int ret;
1584
1585                 if (!cursor->resid) {
1586                         ceph_msg_data_advance(cursor, 0);
1587                         continue;
1588                 }
1589
1590                 page = ceph_msg_data_next(cursor, &page_offset, &length, NULL);
1591                 if (length == cursor->total_resid)
1592                         more = MSG_MORE;
1593                 ret = ceph_tcp_sendpage(con->sock, page, page_offset, length,
1594                                         more);
1595                 if (ret <= 0) {
1596                         if (do_datacrc)
1597                                 msg->footer.data_crc = cpu_to_le32(crc);
1598
1599                         return ret;
1600                 }
1601                 if (do_datacrc && cursor->need_crc)
1602                         crc = ceph_crc32c_page(crc, page, page_offset, length);
1603                 ceph_msg_data_advance(cursor, (size_t)ret);
1604         }
1605
1606         dout("%s %p msg %p done\n", __func__, con, msg);
1607
1608         /* prepare and queue up footer, too */
1609         if (do_datacrc)
1610                 msg->footer.data_crc = cpu_to_le32(crc);
1611         else
1612                 msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
1613         con_out_kvec_reset(con);
1614         prepare_write_message_footer(con);
1615
1616         return 1;       /* must return > 0 to indicate success */
1617 }
1618
1619 /*
1620  * write some zeros
1621  */
1622 static int write_partial_skip(struct ceph_connection *con)
1623 {
1624         int more = MSG_MORE | MSG_SENDPAGE_NOTLAST;
1625         int ret;
1626
1627         dout("%s %p %d left\n", __func__, con, con->out_skip);
1628         while (con->out_skip > 0) {
1629                 size_t size = min(con->out_skip, (int) PAGE_SIZE);
1630
1631                 if (size == con->out_skip)
1632                         more = MSG_MORE;
1633                 ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, more);
1634                 if (ret <= 0)
1635                         goto out;
1636                 con->out_skip -= ret;
1637         }
1638         ret = 1;
1639 out:
1640         return ret;
1641 }
1642
1643 /*
1644  * Prepare to read connection handshake, or an ack.
1645  */
1646 static void prepare_read_banner(struct ceph_connection *con)
1647 {
1648         dout("prepare_read_banner %p\n", con);
1649         con->in_base_pos = 0;
1650 }
1651
1652 static void prepare_read_connect(struct ceph_connection *con)
1653 {
1654         dout("prepare_read_connect %p\n", con);
1655         con->in_base_pos = 0;
1656 }
1657
1658 static void prepare_read_ack(struct ceph_connection *con)
1659 {
1660         dout("prepare_read_ack %p\n", con);
1661         con->in_base_pos = 0;
1662 }
1663
1664 static void prepare_read_seq(struct ceph_connection *con)
1665 {
1666         dout("prepare_read_seq %p\n", con);
1667         con->in_base_pos = 0;
1668         con->in_tag = CEPH_MSGR_TAG_SEQ;
1669 }
1670
1671 static void prepare_read_tag(struct ceph_connection *con)
1672 {
1673         dout("prepare_read_tag %p\n", con);
1674         con->in_base_pos = 0;
1675         con->in_tag = CEPH_MSGR_TAG_READY;
1676 }
1677
1678 static void prepare_read_keepalive_ack(struct ceph_connection *con)
1679 {
1680         dout("prepare_read_keepalive_ack %p\n", con);
1681         con->in_base_pos = 0;
1682 }
1683
1684 /*
1685  * Prepare to read a message.
1686  */
1687 static int prepare_read_message(struct ceph_connection *con)
1688 {
1689         dout("prepare_read_message %p\n", con);
1690         BUG_ON(con->in_msg != NULL);
1691         con->in_base_pos = 0;
1692         con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
1693         return 0;
1694 }
1695
1696
1697 static int read_partial(struct ceph_connection *con,
1698                         int end, int size, void *object)
1699 {
1700         while (con->in_base_pos < end) {
1701                 int left = end - con->in_base_pos;
1702                 int have = size - left;
1703                 int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
1704                 if (ret <= 0)
1705                         return ret;
1706                 con->in_base_pos += ret;
1707         }
1708         return 1;
1709 }
1710
1711
1712 /*
1713  * Read all or part of the connect-side handshake on a new connection
1714  */
1715 static int read_partial_banner(struct ceph_connection *con)
1716 {
1717         int size;
1718         int end;
1719         int ret;
1720
1721         dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
1722
1723         /* peer's banner */
1724         size = strlen(CEPH_BANNER);
1725         end = size;
1726         ret = read_partial(con, end, size, con->in_banner);
1727         if (ret <= 0)
1728                 goto out;
1729
1730         size = sizeof (con->actual_peer_addr);
1731         end += size;
1732         ret = read_partial(con, end, size, &con->actual_peer_addr);
1733         if (ret <= 0)
1734                 goto out;
1735
1736         size = sizeof (con->peer_addr_for_me);
1737         end += size;
1738         ret = read_partial(con, end, size, &con->peer_addr_for_me);
1739         if (ret <= 0)
1740                 goto out;
1741
1742 out:
1743         return ret;
1744 }
1745
1746 static int read_partial_connect(struct ceph_connection *con)
1747 {
1748         int size;
1749         int end;
1750         int ret;
1751
1752         dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
1753
1754         size = sizeof (con->in_reply);
1755         end = size;
1756         ret = read_partial(con, end, size, &con->in_reply);
1757         if (ret <= 0)
1758                 goto out;
1759
1760         if (con->auth) {
1761                 size = le32_to_cpu(con->in_reply.authorizer_len);
1762                 if (size > con->auth->authorizer_reply_buf_len) {
1763                         pr_err("authorizer reply too big: %d > %zu\n", size,
1764                                con->auth->authorizer_reply_buf_len);
1765                         ret = -EINVAL;
1766                         goto out;
1767                 }
1768
1769                 end += size;
1770                 ret = read_partial(con, end, size,
1771                                    con->auth->authorizer_reply_buf);
1772                 if (ret <= 0)
1773                         goto out;
1774         }
1775
1776         dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
1777              con, (int)con->in_reply.tag,
1778              le32_to_cpu(con->in_reply.connect_seq),
1779              le32_to_cpu(con->in_reply.global_seq));
1780 out:
1781         return ret;
1782 }
1783
1784 /*
1785  * Verify the hello banner looks okay.
1786  */
1787 static int verify_hello(struct ceph_connection *con)
1788 {
1789         if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
1790                 pr_err("connect to %s got bad banner\n",
1791                        ceph_pr_addr(&con->peer_addr.in_addr));
1792                 con->error_msg = "protocol error, bad banner";
1793                 return -1;
1794         }
1795         return 0;
1796 }
1797
1798 static bool addr_is_blank(struct sockaddr_storage *ss)
1799 {
1800         struct in_addr *addr = &((struct sockaddr_in *)ss)->sin_addr;
1801         struct in6_addr *addr6 = &((struct sockaddr_in6 *)ss)->sin6_addr;
1802
1803         switch (ss->ss_family) {
1804         case AF_INET:
1805                 return addr->s_addr == htonl(INADDR_ANY);
1806         case AF_INET6:
1807                 return ipv6_addr_any(addr6);
1808         default:
1809                 return true;
1810         }
1811 }
1812
1813 static int addr_port(struct sockaddr_storage *ss)
1814 {
1815         switch (ss->ss_family) {
1816         case AF_INET:
1817                 return ntohs(((struct sockaddr_in *)ss)->sin_port);
1818         case AF_INET6:
1819                 return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
1820         }
1821         return 0;
1822 }
1823
1824 static void addr_set_port(struct sockaddr_storage *ss, int p)
1825 {
1826         switch (ss->ss_family) {
1827         case AF_INET:
1828                 ((struct sockaddr_in *)ss)->sin_port = htons(p);
1829                 break;
1830         case AF_INET6:
1831                 ((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
1832                 break;
1833         }
1834 }
1835
1836 /*
1837  * Unlike other *_pton function semantics, zero indicates success.
1838  */
1839 static int ceph_pton(const char *str, size_t len, struct sockaddr_storage *ss,
1840                 char delim, const char **ipend)
1841 {
1842         struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
1843         struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
1844
1845         memset(ss, 0, sizeof(*ss));
1846
1847         if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) {
1848                 ss->ss_family = AF_INET;
1849                 return 0;
1850         }
1851
1852         if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) {
1853                 ss->ss_family = AF_INET6;
1854                 return 0;
1855         }
1856
1857         return -EINVAL;
1858 }
1859
1860 /*
1861  * Extract hostname string and resolve using kernel DNS facility.
1862  */
1863 #ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
1864 static int ceph_dns_resolve_name(const char *name, size_t namelen,
1865                 struct sockaddr_storage *ss, char delim, const char **ipend)
1866 {
1867         const char *end, *delim_p;
1868         char *colon_p, *ip_addr = NULL;
1869         int ip_len, ret;
1870
1871         /*
1872          * The end of the hostname occurs immediately preceding the delimiter or
1873          * the port marker (':') where the delimiter takes precedence.
1874          */
1875         delim_p = memchr(name, delim, namelen);
1876         colon_p = memchr(name, ':', namelen);
1877
1878         if (delim_p && colon_p)
1879                 end = delim_p < colon_p ? delim_p : colon_p;
1880         else if (!delim_p && colon_p)
1881                 end = colon_p;
1882         else {
1883                 end = delim_p;
1884                 if (!end) /* case: hostname:/ */
1885                         end = name + namelen;
1886         }
1887
1888         if (end <= name)
1889                 return -EINVAL;
1890
1891         /* do dns_resolve upcall */
1892         ip_len = dns_query(NULL, name, end - name, NULL, &ip_addr, NULL);
1893         if (ip_len > 0)
1894                 ret = ceph_pton(ip_addr, ip_len, ss, -1, NULL);
1895         else
1896                 ret = -ESRCH;
1897
1898         kfree(ip_addr);
1899
1900         *ipend = end;
1901
1902         pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
1903                         ret, ret ? "failed" : ceph_pr_addr(ss));
1904
1905         return ret;
1906 }
1907 #else
1908 static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
1909                 struct sockaddr_storage *ss, char delim, const char **ipend)
1910 {
1911         return -EINVAL;
1912 }
1913 #endif
1914
1915 /*
1916  * Parse a server name (IP or hostname). If a valid IP address is not found
1917  * then try to extract a hostname to resolve using userspace DNS upcall.
1918  */
1919 static int ceph_parse_server_name(const char *name, size_t namelen,
1920                         struct sockaddr_storage *ss, char delim, const char **ipend)
1921 {
1922         int ret;
1923
1924         ret = ceph_pton(name, namelen, ss, delim, ipend);
1925         if (ret)
1926                 ret = ceph_dns_resolve_name(name, namelen, ss, delim, ipend);
1927
1928         return ret;
1929 }
1930
1931 /*
1932  * Parse an ip[:port] list into an addr array.  Use the default
1933  * monitor port if a port isn't specified.
1934  */
1935 int ceph_parse_ips(const char *c, const char *end,
1936                    struct ceph_entity_addr *addr,
1937                    int max_count, int *count)
1938 {
1939         int i, ret = -EINVAL;
1940         const char *p = c;
1941
1942         dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1943         for (i = 0; i < max_count; i++) {
1944                 const char *ipend;
1945                 struct sockaddr_storage *ss = &addr[i].in_addr;
1946                 int port;
1947                 char delim = ',';
1948
1949                 if (*p == '[') {
1950                         delim = ']';
1951                         p++;
1952                 }
1953
1954                 ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend);
1955                 if (ret)
1956                         goto bad;
1957                 ret = -EINVAL;
1958
1959                 p = ipend;
1960
1961                 if (delim == ']') {
1962                         if (*p != ']') {
1963                                 dout("missing matching ']'\n");
1964                                 goto bad;
1965                         }
1966                         p++;
1967                 }
1968
1969                 /* port? */
1970                 if (p < end && *p == ':') {
1971                         port = 0;
1972                         p++;
1973                         while (p < end && *p >= '0' && *p <= '9') {
1974                                 port = (port * 10) + (*p - '0');
1975                                 p++;
1976                         }
1977                         if (port == 0)
1978                                 port = CEPH_MON_PORT;
1979                         else if (port > 65535)
1980                                 goto bad;
1981                 } else {
1982                         port = CEPH_MON_PORT;
1983                 }
1984
1985                 addr_set_port(ss, port);
1986
1987                 dout("parse_ips got %s\n", ceph_pr_addr(ss));
1988
1989                 if (p == end)
1990                         break;
1991                 if (*p != ',')
1992                         goto bad;
1993                 p++;
1994         }
1995
1996         if (p != end)
1997                 goto bad;
1998
1999         if (count)
2000                 *count = i + 1;
2001         return 0;
2002
2003 bad:
2004         pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
2005         return ret;
2006 }
2007 EXPORT_SYMBOL(ceph_parse_ips);
2008
2009 static int process_banner(struct ceph_connection *con)
2010 {
2011         dout("process_banner on %p\n", con);
2012
2013         if (verify_hello(con) < 0)
2014                 return -1;
2015
2016         ceph_decode_addr(&con->actual_peer_addr);
2017         ceph_decode_addr(&con->peer_addr_for_me);
2018
2019         /*
2020          * Make sure the other end is who we wanted.  note that the other
2021          * end may not yet know their ip address, so if it's 0.0.0.0, give
2022          * them the benefit of the doubt.
2023          */
2024         if (memcmp(&con->peer_addr, &con->actual_peer_addr,
2025                    sizeof(con->peer_addr)) != 0 &&
2026             !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
2027               con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
2028                 pr_warn("wrong peer, want %s/%d, got %s/%d\n",
2029                         ceph_pr_addr(&con->peer_addr.in_addr),
2030                         (int)le32_to_cpu(con->peer_addr.nonce),
2031                         ceph_pr_addr(&con->actual_peer_addr.in_addr),
2032                         (int)le32_to_cpu(con->actual_peer_addr.nonce));
2033                 con->error_msg = "wrong peer at address";
2034                 return -1;
2035         }
2036
2037         /*
2038          * did we learn our address?
2039          */
2040         if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
2041                 int port = addr_port(&con->msgr->inst.addr.in_addr);
2042
2043                 memcpy(&con->msgr->inst.addr.in_addr,
2044                        &con->peer_addr_for_me.in_addr,
2045                        sizeof(con->peer_addr_for_me.in_addr));
2046                 addr_set_port(&con->msgr->inst.addr.in_addr, port);
2047                 encode_my_addr(con->msgr);
2048                 dout("process_banner learned my addr is %s\n",
2049                      ceph_pr_addr(&con->msgr->inst.addr.in_addr));
2050         }
2051
2052         return 0;
2053 }
2054
2055 static int process_connect(struct ceph_connection *con)
2056 {
2057         u64 sup_feat = from_msgr(con->msgr)->supported_features;
2058         u64 req_feat = from_msgr(con->msgr)->required_features;
2059         u64 server_feat = le64_to_cpu(con->in_reply.features);
2060         int ret;
2061
2062         dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
2063
2064         if (con->auth) {
2065                 int len = le32_to_cpu(con->in_reply.authorizer_len);
2066
2067                 /*
2068                  * Any connection that defines ->get_authorizer()
2069                  * should also define ->add_authorizer_challenge() and
2070                  * ->verify_authorizer_reply().
2071                  *
2072                  * See get_connect_authorizer().
2073                  */
2074                 if (con->in_reply.tag == CEPH_MSGR_TAG_CHALLENGE_AUTHORIZER) {
2075                         ret = con->ops->add_authorizer_challenge(
2076                                     con, con->auth->authorizer_reply_buf, len);
2077                         if (ret < 0)
2078                                 return ret;
2079
2080                         con_out_kvec_reset(con);
2081                         __prepare_write_connect(con);
2082                         prepare_read_connect(con);
2083                         return 0;
2084                 }
2085
2086                 if (len) {
2087                         ret = con->ops->verify_authorizer_reply(con);
2088                         if (ret < 0) {
2089                                 con->error_msg = "bad authorize reply";
2090                                 return ret;
2091                         }
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         con_flag_set(con, CON_FLAG_KEEPALIVE_PENDING);
3217         mutex_unlock(&con->mutex);
3218
3219         if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
3220                 queue_con(con);
3221 }
3222 EXPORT_SYMBOL(ceph_con_keepalive);
3223
3224 bool ceph_con_keepalive_expired(struct ceph_connection *con,
3225                                unsigned long interval)
3226 {
3227         if (interval > 0 &&
3228             (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
3229                 struct timespec64 now;
3230                 struct timespec64 ts;
3231                 ktime_get_real_ts64(&now);
3232                 jiffies_to_timespec64(interval, &ts);
3233                 ts = timespec64_add(con->last_keepalive_ack, ts);
3234                 return timespec64_compare(&now, &ts) >= 0;
3235         }
3236         return false;
3237 }
3238
3239 static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
3240 {
3241         BUG_ON(msg->num_data_items >= msg->max_data_items);
3242         return &msg->data[msg->num_data_items++];
3243 }
3244
3245 static void ceph_msg_data_destroy(struct ceph_msg_data *data)
3246 {
3247         if (data->type == CEPH_MSG_DATA_PAGELIST)
3248                 ceph_pagelist_release(data->pagelist);
3249 }
3250
3251 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
3252                 size_t length, size_t alignment)
3253 {
3254         struct ceph_msg_data *data;
3255
3256         BUG_ON(!pages);
3257         BUG_ON(!length);
3258
3259         data = ceph_msg_data_add(msg);
3260         data->type = CEPH_MSG_DATA_PAGES;
3261         data->pages = pages;
3262         data->length = length;
3263         data->alignment = alignment & ~PAGE_MASK;
3264
3265         msg->data_length += length;
3266 }
3267 EXPORT_SYMBOL(ceph_msg_data_add_pages);
3268
3269 void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
3270                                 struct ceph_pagelist *pagelist)
3271 {
3272         struct ceph_msg_data *data;
3273
3274         BUG_ON(!pagelist);
3275         BUG_ON(!pagelist->length);
3276
3277         data = ceph_msg_data_add(msg);
3278         data->type = CEPH_MSG_DATA_PAGELIST;
3279         refcount_inc(&pagelist->refcnt);
3280         data->pagelist = pagelist;
3281
3282         msg->data_length += pagelist->length;
3283 }
3284 EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
3285
3286 #ifdef  CONFIG_BLOCK
3287 void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
3288                            u32 length)
3289 {
3290         struct ceph_msg_data *data;
3291
3292         data = ceph_msg_data_add(msg);
3293         data->type = CEPH_MSG_DATA_BIO;
3294         data->bio_pos = *bio_pos;
3295         data->bio_length = length;
3296
3297         msg->data_length += length;
3298 }
3299 EXPORT_SYMBOL(ceph_msg_data_add_bio);
3300 #endif  /* CONFIG_BLOCK */
3301
3302 void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
3303                              struct ceph_bvec_iter *bvec_pos)
3304 {
3305         struct ceph_msg_data *data;
3306
3307         data = ceph_msg_data_add(msg);
3308         data->type = CEPH_MSG_DATA_BVECS;
3309         data->bvec_pos = *bvec_pos;
3310
3311         msg->data_length += bvec_pos->iter.bi_size;
3312 }
3313 EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
3314
3315 /*
3316  * construct a new message with given type, size
3317  * the new msg has a ref count of 1.
3318  */
3319 struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
3320                                gfp_t flags, bool can_fail)
3321 {
3322         struct ceph_msg *m;
3323
3324         m = kmem_cache_zalloc(ceph_msg_cache, flags);
3325         if (m == NULL)
3326                 goto out;
3327
3328         m->hdr.type = cpu_to_le16(type);
3329         m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
3330         m->hdr.front_len = cpu_to_le32(front_len);
3331
3332         INIT_LIST_HEAD(&m->list_head);
3333         kref_init(&m->kref);
3334
3335         /* front */
3336         if (front_len) {
3337                 m->front.iov_base = ceph_kvmalloc(front_len, flags);
3338                 if (m->front.iov_base == NULL) {
3339                         dout("ceph_msg_new can't allocate %d bytes\n",
3340                              front_len);
3341                         goto out2;
3342                 }
3343         } else {
3344                 m->front.iov_base = NULL;
3345         }
3346         m->front_alloc_len = m->front.iov_len = front_len;
3347
3348         if (max_data_items) {
3349                 m->data = kmalloc_array(max_data_items, sizeof(*m->data),
3350                                         flags);
3351                 if (!m->data)
3352                         goto out2;
3353
3354                 m->max_data_items = max_data_items;
3355         }
3356
3357         dout("ceph_msg_new %p front %d\n", m, front_len);
3358         return m;
3359
3360 out2:
3361         ceph_msg_put(m);
3362 out:
3363         if (!can_fail) {
3364                 pr_err("msg_new can't create type %d front %d\n", type,
3365                        front_len);
3366                 WARN_ON(1);
3367         } else {
3368                 dout("msg_new can't create type %d front %d\n", type,
3369                      front_len);
3370         }
3371         return NULL;
3372 }
3373 EXPORT_SYMBOL(ceph_msg_new2);
3374
3375 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
3376                               bool can_fail)
3377 {
3378         return ceph_msg_new2(type, front_len, 0, flags, can_fail);
3379 }
3380 EXPORT_SYMBOL(ceph_msg_new);
3381
3382 /*
3383  * Allocate "middle" portion of a message, if it is needed and wasn't
3384  * allocated by alloc_msg.  This allows us to read a small fixed-size
3385  * per-type header in the front and then gracefully fail (i.e.,
3386  * propagate the error to the caller based on info in the front) when
3387  * the middle is too large.
3388  */
3389 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
3390 {
3391         int type = le16_to_cpu(msg->hdr.type);
3392         int middle_len = le32_to_cpu(msg->hdr.middle_len);
3393
3394         dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
3395              ceph_msg_type_name(type), middle_len);
3396         BUG_ON(!middle_len);
3397         BUG_ON(msg->middle);
3398
3399         msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
3400         if (!msg->middle)
3401                 return -ENOMEM;
3402         return 0;
3403 }
3404
3405 /*
3406  * Allocate a message for receiving an incoming message on a
3407  * connection, and save the result in con->in_msg.  Uses the
3408  * connection's private alloc_msg op if available.
3409  *
3410  * Returns 0 on success, or a negative error code.
3411  *
3412  * On success, if we set *skip = 1:
3413  *  - the next message should be skipped and ignored.
3414  *  - con->in_msg == NULL
3415  * or if we set *skip = 0:
3416  *  - con->in_msg is non-null.
3417  * On error (ENOMEM, EAGAIN, ...),
3418  *  - con->in_msg == NULL
3419  */
3420 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
3421 {
3422         struct ceph_msg_header *hdr = &con->in_hdr;
3423         int middle_len = le32_to_cpu(hdr->middle_len);
3424         struct ceph_msg *msg;
3425         int ret = 0;
3426
3427         BUG_ON(con->in_msg != NULL);
3428         BUG_ON(!con->ops->alloc_msg);
3429
3430         mutex_unlock(&con->mutex);
3431         msg = con->ops->alloc_msg(con, hdr, skip);
3432         mutex_lock(&con->mutex);
3433         if (con->state != CON_STATE_OPEN) {
3434                 if (msg)
3435                         ceph_msg_put(msg);
3436                 return -EAGAIN;
3437         }
3438         if (msg) {
3439                 BUG_ON(*skip);
3440                 msg_con_set(msg, con);
3441                 con->in_msg = msg;
3442         } else {
3443                 /*
3444                  * Null message pointer means either we should skip
3445                  * this message or we couldn't allocate memory.  The
3446                  * former is not an error.
3447                  */
3448                 if (*skip)
3449                         return 0;
3450
3451                 con->error_msg = "error allocating memory for incoming message";
3452                 return -ENOMEM;
3453         }
3454         memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
3455
3456         if (middle_len && !con->in_msg->middle) {
3457                 ret = ceph_alloc_middle(con, con->in_msg);
3458                 if (ret < 0) {
3459                         ceph_msg_put(con->in_msg);
3460                         con->in_msg = NULL;
3461                 }
3462         }
3463
3464         return ret;
3465 }
3466
3467
3468 /*
3469  * Free a generically kmalloc'd message.
3470  */
3471 static void ceph_msg_free(struct ceph_msg *m)
3472 {
3473         dout("%s %p\n", __func__, m);
3474         kvfree(m->front.iov_base);
3475         kfree(m->data);
3476         kmem_cache_free(ceph_msg_cache, m);
3477 }
3478
3479 static void ceph_msg_release(struct kref *kref)
3480 {
3481         struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
3482         int i;
3483
3484         dout("%s %p\n", __func__, m);
3485         WARN_ON(!list_empty(&m->list_head));
3486
3487         msg_con_set(m, NULL);
3488
3489         /* drop middle, data, if any */
3490         if (m->middle) {
3491                 ceph_buffer_put(m->middle);
3492                 m->middle = NULL;
3493         }
3494
3495         for (i = 0; i < m->num_data_items; i++)
3496                 ceph_msg_data_destroy(&m->data[i]);
3497
3498         if (m->pool)
3499                 ceph_msgpool_put(m->pool, m);
3500         else
3501                 ceph_msg_free(m);
3502 }
3503
3504 struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
3505 {
3506         dout("%s %p (was %d)\n", __func__, msg,
3507              kref_read(&msg->kref));
3508         kref_get(&msg->kref);
3509