net/ceph/messenger.c

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This source file includes following definitions.
con_flag_valid
con_flag_clear
con_flag_set
con_flag_test
con_flag_test_and_clear
con_flag_test_and_set
ceph_pr_addr
encode_my_addr
ceph_msgr_slab_init
ceph_msgr_slab_exit
_ceph_msgr_exit
ceph_msgr_init
ceph_msgr_exit
ceph_msgr_flush
con_sock_state_init
con_sock_state_connecting
con_sock_state_connected
con_sock_state_closing
con_sock_state_closed
ceph_sock_data_ready
ceph_sock_write_space
ceph_sock_state_change
set_sock_callbacks
ceph_tcp_connect
ceph_tcp_recvmsg
ceph_tcp_recvpage
ceph_tcp_sendmsg
ceph_tcp_sendpage
con_close_socket
ceph_msg_remove
ceph_msg_remove_list
reset_connection
ceph_con_close
ceph_con_open
ceph_con_opened
ceph_con_init
get_global_seq
con_out_kvec_reset
con_out_kvec_add
con_out_kvec_skip
ceph_msg_data_bio_cursor_init
ceph_msg_data_bio_next
ceph_msg_data_bio_advance
ceph_msg_data_bvecs_cursor_init
ceph_msg_data_bvecs_next
ceph_msg_data_bvecs_advance
ceph_msg_data_pages_cursor_init
ceph_msg_data_pages_next
ceph_msg_data_pages_advance
ceph_msg_data_pagelist_cursor_init
ceph_msg_data_pagelist_next
ceph_msg_data_pagelist_advance
__ceph_msg_data_cursor_init
ceph_msg_data_cursor_init
ceph_msg_data_next
ceph_msg_data_advance
sizeof_footer
prepare_message_data
prepare_write_message_footer
prepare_write_message
prepare_write_ack
prepare_write_seq
prepare_write_keepalive
get_connect_authorizer
prepare_write_banner
__prepare_write_connect
prepare_write_connect
write_partial_kvec
ceph_crc32c_page
write_partial_message_data
write_partial_skip
prepare_read_banner
prepare_read_connect
prepare_read_ack
prepare_read_seq
prepare_read_tag
prepare_read_keepalive_ack
prepare_read_message
read_partial
read_partial_banner
read_partial_connect
verify_hello
addr_is_blank
addr_port
addr_set_port
ceph_pton
ceph_dns_resolve_name
ceph_dns_resolve_name
ceph_parse_server_name
ceph_parse_ips
process_banner
process_connect
read_partial_ack
process_ack
read_partial_message_section
read_partial_msg_data
read_partial_message
process_message
read_keepalive_ack
try_write
try_read
queue_con_delay
queue_con
cancel_con
con_sock_closed
con_backoff
con_fault_finish
ceph_con_workfn
con_fault
ceph_messenger_reset_nonce
ceph_messenger_init
ceph_messenger_fini
msg_con_set
clear_standby
ceph_con_send
ceph_msg_revoke
ceph_msg_revoke_incoming
ceph_con_keepalive
ceph_con_keepalive_expired
ceph_msg_data_add
ceph_msg_data_destroy
ceph_msg_data_add_pages
ceph_msg_data_add_pagelist
ceph_msg_data_add_bio
ceph_msg_data_add_bvecs
ceph_msg_new2
ceph_msg_new
ceph_alloc_middle
ceph_con_in_msg_alloc
ceph_msg_free
ceph_msg_release
ceph_msg_get
ceph_msg_put
ceph_msg_dump
   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 ceph_entity_addr *addr)
 190 {
 191         int i;
 192         char *s;
 193         struct sockaddr_storage ss = addr->in_addr; /* align */
 194         struct sockaddr_in *in4 = (struct sockaddr_in *)&ss;
 195         struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&ss;
 196 
 197         i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
 198         s = addr_str[i];
 199 
 200         switch (ss.ss_family) {
 201         case AF_INET:
 202                 snprintf(s, MAX_ADDR_STR_LEN, "(%d)%pI4:%hu",
 203                          le32_to_cpu(addr->type), &in4->sin_addr,
 204                          ntohs(in4->sin_port));
 205                 break;
 206 
 207         case AF_INET6:
 208                 snprintf(s, MAX_ADDR_STR_LEN, "(%d)[%pI6c]:%hu",
 209                          le32_to_cpu(addr->type), &in6->sin6_addr,
 210                          ntohs(in6->sin6_port));
 211                 break;
 212 
 213         default:
 214                 snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
 215                          ss.ss_family);
 216         }
 217 
 218         return s;
 219 }
 220 EXPORT_SYMBOL(ceph_pr_addr);
 221 
 222 static void encode_my_addr(struct ceph_messenger *msgr)
 223 {
 224         memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
 225         ceph_encode_banner_addr(&msgr->my_enc_addr);
 226 }
 227 
 228 /*
 229  * work queue for all reading and writing to/from the socket.
 230  */
 231 static struct workqueue_struct *ceph_msgr_wq;
 232 
 233 static int ceph_msgr_slab_init(void)
 234 {
 235         BUG_ON(ceph_msg_cache);
 236         ceph_msg_cache = KMEM_CACHE(ceph_msg, 0);
 237         if (!ceph_msg_cache)
 238                 return -ENOMEM;
 239 
 240         return 0;
 241 }
 242 
 243 static void ceph_msgr_slab_exit(void)
 244 {
 245         BUG_ON(!ceph_msg_cache);
 246         kmem_cache_destroy(ceph_msg_cache);
 247         ceph_msg_cache = NULL;
 248 }
 249 
 250 static void _ceph_msgr_exit(void)
 251 {
 252         if (ceph_msgr_wq) {
 253                 destroy_workqueue(ceph_msgr_wq);
 254                 ceph_msgr_wq = NULL;
 255         }
 256 
 257         BUG_ON(zero_page == NULL);
 258         put_page(zero_page);
 259         zero_page = NULL;
 260 
 261         ceph_msgr_slab_exit();
 262 }
 263 
 264 int __init ceph_msgr_init(void)
 265 {
 266         if (ceph_msgr_slab_init())
 267                 return -ENOMEM;
 268 
 269         BUG_ON(zero_page != NULL);
 270         zero_page = ZERO_PAGE(0);
 271         get_page(zero_page);
 272 
 273         /*
 274          * The number of active work items is limited by the number of
 275          * connections, so leave @max_active at default.
 276          */
 277         ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
 278         if (ceph_msgr_wq)
 279                 return 0;
 280 
 281         pr_err("msgr_init failed to create workqueue\n");
 282         _ceph_msgr_exit();
 283 
 284         return -ENOMEM;
 285 }
 286 
 287 void ceph_msgr_exit(void)
 288 {
 289         BUG_ON(ceph_msgr_wq == NULL);
 290 
 291         _ceph_msgr_exit();
 292 }
 293 
 294 void ceph_msgr_flush(void)
 295 {
 296         flush_workqueue(ceph_msgr_wq);
 297 }
 298 EXPORT_SYMBOL(ceph_msgr_flush);
 299 
 300 /* Connection socket state transition functions */
 301 
 302 static void con_sock_state_init(struct ceph_connection *con)
 303 {
 304         int old_state;
 305 
 306         old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
 307         if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
 308                 printk("%s: unexpected old state %d\n", __func__, old_state);
 309         dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 310              CON_SOCK_STATE_CLOSED);
 311 }
 312 
 313 static void con_sock_state_connecting(struct ceph_connection *con)
 314 {
 315         int old_state;
 316 
 317         old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
 318         if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
 319                 printk("%s: unexpected old state %d\n", __func__, old_state);
 320         dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 321              CON_SOCK_STATE_CONNECTING);
 322 }
 323 
 324 static void con_sock_state_connected(struct ceph_connection *con)
 325 {
 326         int old_state;
 327 
 328         old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
 329         if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
 330                 printk("%s: unexpected old state %d\n", __func__, old_state);
 331         dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 332              CON_SOCK_STATE_CONNECTED);
 333 }
 334 
 335 static void con_sock_state_closing(struct ceph_connection *con)
 336 {
 337         int old_state;
 338 
 339         old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
 340         if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
 341                         old_state != CON_SOCK_STATE_CONNECTED &&
 342                         old_state != CON_SOCK_STATE_CLOSING))
 343                 printk("%s: unexpected old state %d\n", __func__, old_state);
 344         dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 345              CON_SOCK_STATE_CLOSING);
 346 }
 347 
 348 static void con_sock_state_closed(struct ceph_connection *con)
 349 {
 350         int old_state;
 351 
 352         old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
 353         if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
 354                     old_state != CON_SOCK_STATE_CLOSING &&
 355                     old_state != CON_SOCK_STATE_CONNECTING &&
 356                     old_state != CON_SOCK_STATE_CLOSED))
 357                 printk("%s: unexpected old state %d\n", __func__, old_state);
 358         dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 359              CON_SOCK_STATE_CLOSED);
 360 }
 361 
 362 /*
 363  * socket callback functions
 364  */
 365 
 366 /* data available on socket, or listen socket received a connect */
 367 static void ceph_sock_data_ready(struct sock *sk)
 368 {
 369         struct ceph_connection *con = sk->sk_user_data;
 370         if (atomic_read(&con->msgr->stopping)) {
 371                 return;
 372         }
 373 
 374         if (sk->sk_state != TCP_CLOSE_WAIT) {
 375                 dout("%s on %p state = %lu, queueing work\n", __func__,
 376                      con, con->state);
 377                 queue_con(con);
 378         }
 379 }
 380 
 381 /* socket has buffer space for writing */
 382 static void ceph_sock_write_space(struct sock *sk)
 383 {
 384         struct ceph_connection *con = sk->sk_user_data;
 385 
 386         /* only queue to workqueue if there is data we want to write,
 387          * and there is sufficient space in the socket buffer to accept
 388          * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
 389          * doesn't get called again until try_write() fills the socket
 390          * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
 391          * and net/core/stream.c:sk_stream_write_space().
 392          */
 393         if (con_flag_test(con, CON_FLAG_WRITE_PENDING)) {
 394                 if (sk_stream_is_writeable(sk)) {
 395                         dout("%s %p queueing write work\n", __func__, con);
 396                         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 397                         queue_con(con);
 398                 }
 399         } else {
 400                 dout("%s %p nothing to write\n", __func__, con);
 401         }
 402 }
 403 
 404 /* socket's state has changed */
 405 static void ceph_sock_state_change(struct sock *sk)
 406 {
 407         struct ceph_connection *con = sk->sk_user_data;
 408 
 409         dout("%s %p state = %lu sk_state = %u\n", __func__,
 410              con, con->state, sk->sk_state);
 411 
 412         switch (sk->sk_state) {
 413         case TCP_CLOSE:
 414                 dout("%s TCP_CLOSE\n", __func__);
 415                 /* fall through */
 416         case TCP_CLOSE_WAIT:
 417                 dout("%s TCP_CLOSE_WAIT\n", __func__);
 418                 con_sock_state_closing(con);
 419                 con_flag_set(con, CON_FLAG_SOCK_CLOSED);
 420                 queue_con(con);
 421                 break;
 422         case TCP_ESTABLISHED:
 423                 dout("%s TCP_ESTABLISHED\n", __func__);
 424                 con_sock_state_connected(con);
 425                 queue_con(con);
 426                 break;
 427         default:        /* Everything else is uninteresting */
 428                 break;
 429         }
 430 }
 431 
 432 /*
 433  * set up socket callbacks
 434  */
 435 static void set_sock_callbacks(struct socket *sock,
 436                                struct ceph_connection *con)
 437 {
 438         struct sock *sk = sock->sk;
 439         sk->sk_user_data = con;
 440         sk->sk_data_ready = ceph_sock_data_ready;
 441         sk->sk_write_space = ceph_sock_write_space;
 442         sk->sk_state_change = ceph_sock_state_change;
 443 }
 444 
 445 
 446 /*
 447  * socket helpers
 448  */
 449 
 450 /*
 451  * initiate connection to a remote socket.
 452  */
 453 static int ceph_tcp_connect(struct ceph_connection *con)
 454 {
 455         struct sockaddr_storage ss = con->peer_addr.in_addr; /* align */
 456         struct socket *sock;
 457         unsigned int noio_flag;
 458         int ret;
 459 
 460         BUG_ON(con->sock);
 461 
 462         /* sock_create_kern() allocates with GFP_KERNEL */
 463         noio_flag = memalloc_noio_save();
 464         ret = sock_create_kern(read_pnet(&con->msgr->net), ss.ss_family,
 465                                SOCK_STREAM, IPPROTO_TCP, &sock);
 466         memalloc_noio_restore(noio_flag);
 467         if (ret)
 468                 return ret;
 469         sock->sk->sk_allocation = GFP_NOFS;
 470 
 471 #ifdef CONFIG_LOCKDEP
 472         lockdep_set_class(&sock->sk->sk_lock, &socket_class);
 473 #endif
 474 
 475         set_sock_callbacks(sock, con);
 476 
 477         dout("connect %s\n", ceph_pr_addr(&con->peer_addr));
 478 
 479         con_sock_state_connecting(con);
 480         ret = sock->ops->connect(sock, (struct sockaddr *)&ss, sizeof(ss),
 481                                  O_NONBLOCK);
 482         if (ret == -EINPROGRESS) {
 483                 dout("connect %s EINPROGRESS sk_state = %u\n",
 484                      ceph_pr_addr(&con->peer_addr),
 485                      sock->sk->sk_state);
 486         } else if (ret < 0) {
 487                 pr_err("connect %s error %d\n",
 488                        ceph_pr_addr(&con->peer_addr), ret);
 489                 sock_release(sock);
 490                 return ret;
 491         }
 492 
 493         if (ceph_test_opt(from_msgr(con->msgr), TCP_NODELAY)) {
 494                 int optval = 1;
 495 
 496                 ret = kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
 497                                         (char *)&optval, sizeof(optval));
 498                 if (ret)
 499                         pr_err("kernel_setsockopt(TCP_NODELAY) failed: %d",
 500                                ret);
 501         }
 502 
 503         con->sock = sock;
 504         return 0;
 505 }
 506 
 507 /*
 508  * If @buf is NULL, discard up to @len bytes.
 509  */
 510 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 511 {
 512         struct kvec iov = {buf, len};
 513         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 514         int r;
 515 
 516         if (!buf)
 517                 msg.msg_flags |= MSG_TRUNC;
 518 
 519         iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, len);
 520         r = sock_recvmsg(sock, &msg, msg.msg_flags);
 521         if (r == -EAGAIN)
 522                 r = 0;
 523         return r;
 524 }
 525 
 526 static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
 527                      int page_offset, size_t length)
 528 {
 529         struct bio_vec bvec = {
 530                 .bv_page = page,
 531                 .bv_offset = page_offset,
 532                 .bv_len = length
 533         };
 534         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 535         int r;
 536 
 537         BUG_ON(page_offset + length > PAGE_SIZE);
 538         iov_iter_bvec(&msg.msg_iter, READ, &bvec, 1, length);
 539         r = sock_recvmsg(sock, &msg, msg.msg_flags);
 540         if (r == -EAGAIN)
 541                 r = 0;
 542         return r;
 543 }
 544 
 545 /*
 546  * write something.  @more is true if caller will be sending more data
 547  * shortly.
 548  */
 549 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
 550                             size_t kvlen, size_t len, bool more)
 551 {
 552         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 553         int r;
 554 
 555         if (more)
 556                 msg.msg_flags |= MSG_MORE;
 557         else
 558                 msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 559 
 560         r = kernel_sendmsg(sock, &msg, iov, kvlen, len);
 561         if (r == -EAGAIN)
 562                 r = 0;
 563         return r;
 564 }
 565 
 566 /*
 567  * @more: either or both of MSG_MORE and MSG_SENDPAGE_NOTLAST
 568  */
 569 static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
 570                              int offset, size_t size, int more)
 571 {
 572         ssize_t (*sendpage)(struct socket *sock, struct page *page,
 573                             int offset, size_t size, int flags);
 574         int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more;
 575         int ret;
 576 
 577         /*
 578          * sendpage cannot properly handle pages with page_count == 0,
 579          * we need to fall back to sendmsg if that's the case.
 580          *
 581          * Same goes for slab pages: skb_can_coalesce() allows
 582          * coalescing neighboring slab objects into a single frag which
 583          * triggers one of hardened usercopy checks.
 584          */
 585         if (page_count(page) >= 1 && !PageSlab(page))
 586                 sendpage = sock->ops->sendpage;
 587         else
 588                 sendpage = sock_no_sendpage;
 589 
 590         ret = sendpage(sock, page, offset, size, flags);
 591         if (ret == -EAGAIN)
 592                 ret = 0;
 593 
 594         return ret;
 595 }
 596 
 597 /*
 598  * Shutdown/close the socket for the given connection.
 599  */
 600 static int con_close_socket(struct ceph_connection *con)
 601 {
 602         int rc = 0;
 603 
 604         dout("con_close_socket on %p sock %p\n", con, con->sock);
 605         if (con->sock) {
 606                 rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
 607                 sock_release(con->sock);
 608                 con->sock = NULL;
 609         }
 610 
 611         /*
 612          * Forcibly clear the SOCK_CLOSED flag.  It gets set
 613          * independent of the connection mutex, and we could have
 614          * received a socket close event before we had the chance to
 615          * shut the socket down.
 616          */
 617         con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
 618 
 619         con_sock_state_closed(con);
 620         return rc;
 621 }
 622 
 623 /*
 624  * Reset a connection.  Discard all incoming and outgoing messages
 625  * and clear *_seq state.
 626  */
 627 static void ceph_msg_remove(struct ceph_msg *msg)
 628 {
 629         list_del_init(&msg->list_head);
 630 
 631         ceph_msg_put(msg);
 632 }
 633 static void ceph_msg_remove_list(struct list_head *head)
 634 {
 635         while (!list_empty(head)) {
 636                 struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
 637                                                         list_head);
 638                 ceph_msg_remove(msg);
 639         }
 640 }
 641 
 642 static void reset_connection(struct ceph_connection *con)
 643 {
 644         /* reset connection, out_queue, msg_ and connect_seq */
 645         /* discard existing out_queue and msg_seq */
 646         dout("reset_connection %p\n", con);
 647         ceph_msg_remove_list(&con->out_queue);
 648         ceph_msg_remove_list(&con->out_sent);
 649 
 650         if (con->in_msg) {
 651                 BUG_ON(con->in_msg->con != con);
 652                 ceph_msg_put(con->in_msg);
 653                 con->in_msg = NULL;
 654         }
 655 
 656         con->connect_seq = 0;
 657         con->out_seq = 0;
 658         if (con->out_msg) {
 659                 BUG_ON(con->out_msg->con != con);
 660                 ceph_msg_put(con->out_msg);
 661                 con->out_msg = NULL;
 662         }
 663         con->in_seq = 0;
 664         con->in_seq_acked = 0;
 665 
 666         con->out_skip = 0;
 667 }
 668 
 669 /*
 670  * mark a peer down.  drop any open connections.
 671  */
 672 void ceph_con_close(struct ceph_connection *con)
 673 {
 674         mutex_lock(&con->mutex);
 675         dout("con_close %p peer %s\n", con, ceph_pr_addr(&con->peer_addr));
 676         con->state = CON_STATE_CLOSED;
 677 
 678         con_flag_clear(con, CON_FLAG_LOSSYTX);  /* so we retry next connect */
 679         con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
 680         con_flag_clear(con, CON_FLAG_WRITE_PENDING);
 681         con_flag_clear(con, CON_FLAG_BACKOFF);
 682 
 683         reset_connection(con);
 684         con->peer_global_seq = 0;
 685         cancel_con(con);
 686         con_close_socket(con);
 687         mutex_unlock(&con->mutex);
 688 }
 689 EXPORT_SYMBOL(ceph_con_close);
 690 
 691 /*
 692  * Reopen a closed connection, with a new peer address.
 693  */
 694 void ceph_con_open(struct ceph_connection *con,
 695                    __u8 entity_type, __u64 entity_num,
 696                    struct ceph_entity_addr *addr)
 697 {
 698         mutex_lock(&con->mutex);
 699         dout("con_open %p %s\n", con, ceph_pr_addr(addr));
 700 
 701         WARN_ON(con->state != CON_STATE_CLOSED);
 702         con->state = CON_STATE_PREOPEN;
 703 
 704         con->peer_name.type = (__u8) entity_type;
 705         con->peer_name.num = cpu_to_le64(entity_num);
 706 
 707         memcpy(&con->peer_addr, addr, sizeof(*addr));
 708         con->delay = 0;      /* reset backoff memory */
 709         mutex_unlock(&con->mutex);
 710         queue_con(con);
 711 }
 712 EXPORT_SYMBOL(ceph_con_open);
 713 
 714 /*
 715  * return true if this connection ever successfully opened
 716  */
 717 bool ceph_con_opened(struct ceph_connection *con)
 718 {
 719         return con->connect_seq > 0;
 720 }
 721 
 722 /*
 723  * initialize a new connection.
 724  */
 725 void ceph_con_init(struct ceph_connection *con, void *private,
 726         const struct ceph_connection_operations *ops,
 727         struct ceph_messenger *msgr)
 728 {
 729         dout("con_init %p\n", con);
 730         memset(con, 0, sizeof(*con));
 731         con->private = private;
 732         con->ops = ops;
 733         con->msgr = msgr;
 734 
 735         con_sock_state_init(con);
 736 
 737         mutex_init(&con->mutex);
 738         INIT_LIST_HEAD(&con->out_queue);
 739         INIT_LIST_HEAD(&con->out_sent);
 740         INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
 741 
 742         con->state = CON_STATE_CLOSED;
 743 }
 744 EXPORT_SYMBOL(ceph_con_init);
 745 
 746 
 747 /*
 748  * We maintain a global counter to order connection attempts.  Get
 749  * a unique seq greater than @gt.
 750  */
 751 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
 752 {
 753         u32 ret;
 754 
 755         spin_lock(&msgr->global_seq_lock);
 756         if (msgr->global_seq < gt)
 757                 msgr->global_seq = gt;
 758         ret = ++msgr->global_seq;
 759         spin_unlock(&msgr->global_seq_lock);
 760         return ret;
 761 }
 762 
 763 static void con_out_kvec_reset(struct ceph_connection *con)
 764 {
 765         BUG_ON(con->out_skip);
 766 
 767         con->out_kvec_left = 0;
 768         con->out_kvec_bytes = 0;
 769         con->out_kvec_cur = &con->out_kvec[0];
 770 }
 771 
 772 static void con_out_kvec_add(struct ceph_connection *con,
 773                                 size_t size, void *data)
 774 {
 775         int index = con->out_kvec_left;
 776 
 777         BUG_ON(con->out_skip);
 778         BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
 779 
 780         con->out_kvec[index].iov_len = size;
 781         con->out_kvec[index].iov_base = data;
 782         con->out_kvec_left++;
 783         con->out_kvec_bytes += size;
 784 }
 785 
 786 /*
 787  * Chop off a kvec from the end.  Return residual number of bytes for
 788  * that kvec, i.e. how many bytes would have been written if the kvec
 789  * hadn't been nuked.
 790  */
 791 static int con_out_kvec_skip(struct ceph_connection *con)
 792 {
 793         int off = con->out_kvec_cur - con->out_kvec;
 794         int skip = 0;
 795 
 796         if (con->out_kvec_bytes > 0) {
 797                 skip = con->out_kvec[off + con->out_kvec_left - 1].iov_len;
 798                 BUG_ON(con->out_kvec_bytes < skip);
 799                 BUG_ON(!con->out_kvec_left);
 800                 con->out_kvec_bytes -= skip;
 801                 con->out_kvec_left--;
 802         }
 803 
 804         return skip;
 805 }
 806 
 807 #ifdef CONFIG_BLOCK
 808 
 809 /*
 810  * For a bio data item, a piece is whatever remains of the next
 811  * entry in the current bio iovec, or the first entry in the next
 812  * bio in the list.
 813  */
 814 static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
 815                                         size_t length)
 816 {
 817         struct ceph_msg_data *data = cursor->data;
 818         struct ceph_bio_iter *it = &cursor->bio_iter;
 819 
 820         cursor->resid = min_t(size_t, length, data->bio_length);
 821         *it = data->bio_pos;
 822         if (cursor->resid < it->iter.bi_size)
 823                 it->iter.bi_size = cursor->resid;
 824 
 825         BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
 826         cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
 827 }
 828 
 829 static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
 830                                                 size_t *page_offset,
 831                                                 size_t *length)
 832 {
 833         struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
 834                                            cursor->bio_iter.iter);
 835 
 836         *page_offset = bv.bv_offset;
 837         *length = bv.bv_len;
 838         return bv.bv_page;
 839 }
 840 
 841 static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
 842                                         size_t bytes)
 843 {
 844         struct ceph_bio_iter *it = &cursor->bio_iter;
 845         struct page *page = bio_iter_page(it->bio, it->iter);
 846 
 847         BUG_ON(bytes > cursor->resid);
 848         BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
 849         cursor->resid -= bytes;
 850         bio_advance_iter(it->bio, &it->iter, bytes);
 851 
 852         if (!cursor->resid) {
 853                 BUG_ON(!cursor->last_piece);
 854                 return false;   /* no more data */
 855         }
 856 
 857         if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&
 858                        page == bio_iter_page(it->bio, it->iter)))
 859                 return false;   /* more bytes to process in this segment */
 860 
 861         if (!it->iter.bi_size) {
 862                 it->bio = it->bio->bi_next;
 863                 it->iter = it->bio->bi_iter;
 864                 if (cursor->resid < it->iter.bi_size)
 865                         it->iter.bi_size = cursor->resid;
 866         }
 867 
 868         BUG_ON(cursor->last_piece);
 869         BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
 870         cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
 871         return true;
 872 }
 873 #endif /* CONFIG_BLOCK */
 874 
 875 static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
 876                                         size_t length)
 877 {
 878         struct ceph_msg_data *data = cursor->data;
 879         struct bio_vec *bvecs = data->bvec_pos.bvecs;
 880 
 881         cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
 882         cursor->bvec_iter = data->bvec_pos.iter;
 883         cursor->bvec_iter.bi_size = cursor->resid;
 884 
 885         BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
 886         cursor->last_piece =
 887             cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
 888 }
 889 
 890 static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
 891                                                 size_t *page_offset,
 892                                                 size_t *length)
 893 {
 894         struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
 895                                            cursor->bvec_iter);
 896 
 897         *page_offset = bv.bv_offset;
 898         *length = bv.bv_len;
 899         return bv.bv_page;
 900 }
 901 
 902 static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
 903                                         size_t bytes)
 904 {
 905         struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
 906         struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter);
 907 
 908         BUG_ON(bytes > cursor->resid);
 909         BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
 910         cursor->resid -= bytes;
 911         bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
 912 
 913         if (!cursor->resid) {
 914                 BUG_ON(!cursor->last_piece);
 915                 return false;   /* no more data */
 916         }
 917 
 918         if (!bytes || (cursor->bvec_iter.bi_bvec_done &&
 919                        page == bvec_iter_page(bvecs, cursor->bvec_iter)))
 920                 return false;   /* more bytes to process in this segment */
 921 
 922         BUG_ON(cursor->last_piece);
 923         BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
 924         cursor->last_piece =
 925             cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
 926         return true;
 927 }
 928 
 929 /*
 930  * For a page array, a piece comes from the first page in the array
 931  * that has not already been fully consumed.
 932  */
 933 static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
 934                                         size_t length)
 935 {
 936         struct ceph_msg_data *data = cursor->data;
 937         int page_count;
 938 
 939         BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 940 
 941         BUG_ON(!data->pages);
 942         BUG_ON(!data->length);
 943 
 944         cursor->resid = min(length, data->length);
 945         page_count = calc_pages_for(data->alignment, (u64)data->length);
 946         cursor->page_offset = data->alignment & ~PAGE_MASK;
 947         cursor->page_index = 0;
 948         BUG_ON(page_count > (int)USHRT_MAX);
 949         cursor->page_count = (unsigned short)page_count;
 950         BUG_ON(length > SIZE_MAX - cursor->page_offset);
 951         cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
 952 }
 953 
 954 static struct page *
 955 ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
 956                                         size_t *page_offset, size_t *length)
 957 {
 958         struct ceph_msg_data *data = cursor->data;
 959 
 960         BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 961 
 962         BUG_ON(cursor->page_index >= cursor->page_count);
 963         BUG_ON(cursor->page_offset >= PAGE_SIZE);
 964 
 965         *page_offset = cursor->page_offset;
 966         if (cursor->last_piece)
 967                 *length = cursor->resid;
 968         else
 969                 *length = PAGE_SIZE - *page_offset;
 970 
 971         return data->pages[cursor->page_index];
 972 }
 973 
 974 static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
 975                                                 size_t bytes)
 976 {
 977         BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
 978 
 979         BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
 980 
 981         /* Advance the cursor page offset */
 982 
 983         cursor->resid -= bytes;
 984         cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
 985         if (!bytes || cursor->page_offset)
 986                 return false;   /* more bytes to process in the current page */
 987 
 988         if (!cursor->resid)
 989                 return false;   /* no more data */
 990 
 991         /* Move on to the next page; offset is already at 0 */
 992 
 993         BUG_ON(cursor->page_index >= cursor->page_count);
 994         cursor->page_index++;
 995         cursor->last_piece = cursor->resid <= PAGE_SIZE;
 996 
 997         return true;
 998 }
 999 
1000 /*
1001  * For a pagelist, a piece is whatever remains to be consumed in the
1002  * first page in the list, or the front of the next page.
1003  */
1004 static void
1005 ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
1006                                         size_t length)
1007 {
1008         struct ceph_msg_data *data = cursor->data;
1009         struct ceph_pagelist *pagelist;
1010         struct page *page;
1011 
1012         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1013 
1014         pagelist = data->pagelist;
1015         BUG_ON(!pagelist);
1016 
1017         if (!length)
1018                 return;         /* pagelist can be assigned but empty */
1019 
1020         BUG_ON(list_empty(&pagelist->head));
1021         page = list_first_entry(&pagelist->head, struct page, lru);
1022 
1023         cursor->resid = min(length, pagelist->length);
1024         cursor->page = page;
1025         cursor->offset = 0;
1026         cursor->last_piece = cursor->resid <= PAGE_SIZE;
1027 }
1028 
1029 static struct page *
1030 ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
1031                                 size_t *page_offset, size_t *length)
1032 {
1033         struct ceph_msg_data *data = cursor->data;
1034         struct ceph_pagelist *pagelist;
1035 
1036         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1037 
1038         pagelist = data->pagelist;
1039         BUG_ON(!pagelist);
1040 
1041         BUG_ON(!cursor->page);
1042         BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1043 
1044         /* offset of first page in pagelist is always 0 */
1045         *page_offset = cursor->offset & ~PAGE_MASK;
1046         if (cursor->last_piece)
1047                 *length = cursor->resid;
1048         else
1049                 *length = PAGE_SIZE - *page_offset;
1050 
1051         return cursor->page;
1052 }
1053 
1054 static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
1055                                                 size_t bytes)
1056 {
1057         struct ceph_msg_data *data = cursor->data;
1058         struct ceph_pagelist *pagelist;
1059 
1060         BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
1061 
1062         pagelist = data->pagelist;
1063         BUG_ON(!pagelist);
1064 
1065         BUG_ON(cursor->offset + cursor->resid != pagelist->length);
1066         BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
1067 
1068         /* Advance the cursor offset */
1069 
1070         cursor->resid -= bytes;
1071         cursor->offset += bytes;
1072         /* offset of first page in pagelist is always 0 */
1073         if (!bytes || cursor->offset & ~PAGE_MASK)
1074                 return false;   /* more bytes to process in the current page */
1075 
1076         if (!cursor->resid)
1077                 return false;   /* no more data */
1078 
1079         /* Move on to the next page */
1080 
1081         BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
1082         cursor->page = list_next_entry(cursor->page, lru);
1083         cursor->last_piece = cursor->resid <= PAGE_SIZE;
1084 
1085         return true;
1086 }
1087 
1088 /*
1089  * Message data is handled (sent or received) in pieces, where each
1090  * piece resides on a single page.  The network layer might not
1091  * consume an entire piece at once.  A data item's cursor keeps
1092  * track of which piece is next to process and how much remains to
1093  * be processed in that piece.  It also tracks whether the current
1094  * piece is the last one in the data item.
1095  */
1096 static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
1097 {
1098         size_t length = cursor->total_resid;
1099 
1100         switch (cursor->data->type) {
1101         case CEPH_MSG_DATA_PAGELIST:
1102                 ceph_msg_data_pagelist_cursor_init(cursor, length);
1103                 break;
1104         case CEPH_MSG_DATA_PAGES:
1105                 ceph_msg_data_pages_cursor_init(cursor, length);
1106                 break;
1107 #ifdef CONFIG_BLOCK
1108         case CEPH_MSG_DATA_BIO:
1109                 ceph_msg_data_bio_cursor_init(cursor, length);
1110                 break;
1111 #endif /* CONFIG_BLOCK */
1112         case CEPH_MSG_DATA_BVECS:
1113                 ceph_msg_data_bvecs_cursor_init(cursor, length);
1114                 break;
1115         case CEPH_MSG_DATA_NONE:
1116         default:
1117                 /* BUG(); */
1118                 break;
1119         }
1120         cursor->need_crc = true;
1121 }
1122 
1123 static void ceph_msg_data_cursor_init(struct ceph_msg *msg, size_t length)
1124 {
1125         struct ceph_msg_data_cursor *cursor = &msg->cursor;
1126 
1127         BUG_ON(!length);
1128         BUG_ON(length > msg->data_length);
1129         BUG_ON(!msg->num_data_items);
1130 
1131         cursor->total_resid = length;
1132         cursor->data = msg->data;
1133 
1134         __ceph_msg_data_cursor_init(cursor);
1135 }
1136 
1137 /*
1138  * Return the page containing the next piece to process for a given
1139  * data item, and supply the page offset and length of that piece.
1140  * Indicate whether this is the last piece in this data item.
1141  */
1142 static struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
1143                                         size_t *page_offset, size_t *length,
1144                                         bool *last_piece)
1145 {
1146         struct page *page;
1147 
1148         switch (cursor->data->type) {
1149         case CEPH_MSG_DATA_PAGELIST:
1150                 page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
1151                 break;
1152         case CEPH_MSG_DATA_PAGES:
1153                 page = ceph_msg_data_pages_next(cursor, page_offset, length);
1154                 break;
1155 #ifdef CONFIG_BLOCK
1156         case CEPH_MSG_DATA_BIO:
1157                 page = ceph_msg_data_bio_next(cursor, page_offset, length);
1158                 break;
1159 #endif /* CONFIG_BLOCK */
1160         case CEPH_MSG_DATA_BVECS:
1161                 page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
1162                 break;
1163         case CEPH_MSG_DATA_NONE:
1164         default:
1165                 page = NULL;
1166                 break;
1167         }
1168 
1169         BUG_ON(!page);
1170         BUG_ON(*page_offset + *length > PAGE_SIZE);
1171         BUG_ON(!*length);
1172         BUG_ON(*length > cursor->resid);
1173         if (last_piece)
1174                 *last_piece = cursor->last_piece;
1175 
1176         return page;
1177 }
1178 
1179 /*
1180  * Returns true if the result moves the cursor on to the next piece
1181  * of the data item.
1182  */
1183 static void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor,
1184                                   size_t bytes)
1185 {
1186         bool new_piece;
1187 
1188         BUG_ON(bytes > cursor->resid);
1189         switch (cursor->data->type) {
1190         case CEPH_MSG_DATA_PAGELIST:
1191                 new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
1192                 break;
1193         case CEPH_MSG_DATA_PAGES:
1194                 new_piece = ceph_msg_data_pages_advance(cursor, bytes);
1195                 break;
1196 #ifdef CONFIG_BLOCK
1197         case CEPH_MSG_DATA_BIO:
1198                 new_piece = ceph_msg_data_bio_advance(cursor, bytes);
1199                 break;
1200 #endif /* CONFIG_BLOCK */
1201         case CEPH_MSG_DATA_BVECS:
1202                 new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
1203                 break;
1204         case CEPH_MSG_DATA_NONE:
1205         default:
1206                 BUG();
1207                 break;
1208         }
1209         cursor->total_resid -= bytes;
1210 
1211         if (!cursor->resid && cursor->total_resid) {
1212                 WARN_ON(!cursor->last_piece);
1213                 cursor->data++;
1214                 __ceph_msg_data_cursor_init(cursor);
1215                 new_piece = true;
1216         }
1217         cursor->need_crc = new_piece;
1218 }
1219 
1220 static size_t sizeof_footer(struct ceph_connection *con)
1221 {
1222         return (con->peer_features & CEPH_FEATURE_MSG_AUTH) ?
1223             sizeof(struct ceph_msg_footer) :
1224             sizeof(struct ceph_msg_footer_old);
1225 }
1226 
1227 static void prepare_message_data(struct ceph_msg *msg, u32 data_len)
1228 {
1229         /* Initialize data cursor */
1230 
1231         ceph_msg_data_cursor_init(msg, (size_t)data_len);
1232 }
1233 
1234 /*
1235  * Prepare footer for currently outgoing message, and finish things
1236  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
1237  */
1238 static void prepare_write_message_footer(struct ceph_connection *con)
1239 {
1240         struct ceph_msg *m = con->out_msg;
1241 
1242         m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
1243 
1244         dout("prepare_write_message_footer %p\n", con);
1245         con_out_kvec_add(con, sizeof_footer(con), &m->footer);
1246         if (con->peer_features & CEPH_FEATURE_MSG_AUTH) {
1247                 if (con->ops->sign_message)
1248                         con->ops->sign_message(m);
1249                 else
1250                         m->footer.sig = 0;
1251         } else {
1252                 m->old_footer.flags = m->footer.flags;
1253         }
1254         con->out_more = m->more_to_follow;
1255         con->out_msg_done = true;
1256 }
1257 
1258 /*
1259  * Prepare headers for the next outgoing message.
1260  */
1261 static void prepare_write_message(struct ceph_connection *con)
1262 {
1263         struct ceph_msg *m;
1264         u32 crc;
1265 
1266         con_out_kvec_reset(con);
1267         con->out_msg_done = false;
1268 
1269         /* Sneak an ack in there first?  If we can get it into the same
1270          * TCP packet that's a good thing. */
1271         if (con->in_seq > con->in_seq_acked) {
1272                 con->in_seq_acked = con->in_seq;
1273                 con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1274                 con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1275                 con_out_kvec_add(con, sizeof (con->out_temp_ack),
1276                         &con->out_temp_ack);
1277         }
1278 
1279         BUG_ON(list_empty(&con->out_queue));
1280         m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
1281         con->out_msg = m;
1282         BUG_ON(m->con != con);
1283 
1284         /* put message on sent list */
1285         ceph_msg_get(m);
1286         list_move_tail(&m->list_head, &con->out_sent);
1287 
1288         /*
1289          * only assign outgoing seq # if we haven't sent this message
1290          * yet.  if it is requeued, resend with it's original seq.
1291          */
1292         if (m->needs_out_seq) {
1293                 m->hdr.seq = cpu_to_le64(++con->out_seq);
1294                 m->needs_out_seq = false;
1295 
1296                 if (con->ops->reencode_message)
1297                         con->ops->reencode_message(m);
1298         }
1299 
1300         dout("prepare_write_message %p seq %lld type %d len %d+%d+%zd\n",
1301              m, con->out_seq, le16_to_cpu(m->hdr.type),
1302              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
1303              m->data_length);
1304         WARN_ON(m->front.iov_len != le32_to_cpu(m->hdr.front_len));
1305         WARN_ON(m->data_length != le32_to_cpu(m->hdr.data_len));
1306 
1307         /* tag + hdr + front + middle */
1308         con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
1309         con_out_kvec_add(con, sizeof(con->out_hdr), &con->out_hdr);
1310         con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
1311 
1312         if (m->middle)
1313                 con_out_kvec_add(con, m->middle->vec.iov_len,
1314                         m->middle->vec.iov_base);
1315 
1316         /* fill in hdr crc and finalize hdr */
1317         crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
1318         con->out_msg->hdr.crc = cpu_to_le32(crc);
1319         memcpy(&con->out_hdr, &con->out_msg->hdr, sizeof(con->out_hdr));
1320 
1321         /* fill in front and middle crc, footer */
1322         crc = crc32c(0, m->front.iov_base, m->front.iov_len);
1323         con->out_msg->footer.front_crc = cpu_to_le32(crc);
1324         if (m->middle) {
1325                 crc = crc32c(0, m->middle->vec.iov_base,
1326                                 m->middle->vec.iov_len);
1327                 con->out_msg->footer.middle_crc = cpu_to_le32(crc);
1328         } else
1329                 con->out_msg->footer.middle_crc = 0;
1330         dout("%s front_crc %u middle_crc %u\n", __func__,
1331              le32_to_cpu(con->out_msg->footer.front_crc),
1332              le32_to_cpu(con->out_msg->footer.middle_crc));
1333         con->out_msg->footer.flags = 0;
1334 
1335         /* is there a data payload? */
1336         con->out_msg->footer.data_crc = 0;
1337         if (m->data_length) {
1338                 prepare_message_data(con->out_msg, m->data_length);
1339                 con->out_more = 1;  /* data + footer will follow */
1340         } else {
1341                 /* no, queue up footer too and be done */
1342                 prepare_write_message_footer(con);
1343         }
1344 
1345         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1346 }
1347 
1348 /*
1349  * Prepare an ack.
1350  */
1351 static void prepare_write_ack(struct ceph_connection *con)
1352 {
1353         dout("prepare_write_ack %p %llu -> %llu\n", con,
1354              con->in_seq_acked, con->in_seq);
1355         con->in_seq_acked = con->in_seq;
1356 
1357         con_out_kvec_reset(con);
1358 
1359         con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
1360 
1361         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1362         con_out_kvec_add(con, sizeof (con->out_temp_ack),
1363                                 &con->out_temp_ack);
1364 
1365         con->out_more = 1;  /* more will follow.. eventually.. */
1366         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1367 }
1368 
1369 /*
1370  * Prepare to share the seq during handshake
1371  */
1372 static void prepare_write_seq(struct ceph_connection *con)
1373 {
1374         dout("prepare_write_seq %p %llu -> %llu\n", con,
1375              con->in_seq_acked, con->in_seq);
1376         con->in_seq_acked = con->in_seq;
1377 
1378         con_out_kvec_reset(con);
1379 
1380         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
1381         con_out_kvec_add(con, sizeof (con->out_temp_ack),
1382                          &con->out_temp_ack);
1383 
1384         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1385 }
1386 
1387 /*
1388  * Prepare to write keepalive byte.
1389  */
1390 static void prepare_write_keepalive(struct ceph_connection *con)
1391 {
1392         dout("prepare_write_keepalive %p\n", con);
1393         con_out_kvec_reset(con);
1394         if (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2) {
1395                 struct timespec64 now;
1396 
1397                 ktime_get_real_ts64(&now);
1398                 con_out_kvec_add(con, sizeof(tag_keepalive2), &tag_keepalive2);
1399                 ceph_encode_timespec64(&con->out_temp_keepalive2, &now);
1400                 con_out_kvec_add(con, sizeof(con->out_temp_keepalive2),
1401                                  &con->out_temp_keepalive2);
1402         } else {
1403                 con_out_kvec_add(con, sizeof(tag_keepalive), &tag_keepalive);
1404         }
1405         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1406 }
1407 
1408 /*
1409  * Connection negotiation.
1410  */
1411 
1412 static int get_connect_authorizer(struct ceph_connection *con)
1413 {
1414         struct ceph_auth_handshake *auth;
1415         int auth_proto;
1416 
1417         if (!con->ops->get_authorizer) {
1418                 con->auth = NULL;
1419                 con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
1420                 con->out_connect.authorizer_len = 0;
1421                 return 0;
1422         }
1423 
1424         auth = con->ops->get_authorizer(con, &auth_proto, con->auth_retry);
1425         if (IS_ERR(auth))
1426                 return PTR_ERR(auth);
1427 
1428         con->auth = auth;
1429         con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
1430         con->out_connect.authorizer_len = cpu_to_le32(auth->authorizer_buf_len);
1431         return 0;
1432 }
1433 
1434 /*
1435  * We connected to a peer and are saying hello.
1436  */
1437 static void prepare_write_banner(struct ceph_connection *con)
1438 {
1439         con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
1440         con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
1441                                         &con->msgr->my_enc_addr);
1442 
1443         con->out_more = 0;
1444         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1445 }
1446 
1447 static void __prepare_write_connect(struct ceph_connection *con)
1448 {
1449         con_out_kvec_add(con, sizeof(con->out_connect), &con->out_connect);
1450         if (con->auth)
1451                 con_out_kvec_add(con, con->auth->authorizer_buf_len,
1452                                  con->auth->authorizer_buf);
1453 
1454         con->out_more = 0;
1455         con_flag_set(con, CON_FLAG_WRITE_PENDING);
1456 }
1457 
1458 static int prepare_write_connect(struct ceph_connection *con)
1459 {
1460         unsigned int global_seq = get_global_seq(con->msgr, 0);
1461         int proto;
1462         int ret;
1463 
1464         switch (con->peer_name.type) {
1465         case CEPH_ENTITY_TYPE_MON:
1466                 proto = CEPH_MONC_PROTOCOL;
1467                 break;
1468         case CEPH_ENTITY_TYPE_OSD:
1469                 proto = CEPH_OSDC_PROTOCOL;
1470                 break;
1471         case CEPH_ENTITY_TYPE_MDS:
1472                 proto = CEPH_MDSC_PROTOCOL;
1473                 break;
1474         default:
1475                 BUG();
1476         }
1477 
1478         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
1479              con->connect_seq, global_seq, proto);
1480 
1481         con->out_connect.features =
1482             cpu_to_le64(from_msgr(con->msgr)->supported_features);
1483         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
1484         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
1485         con->out_connect.global_seq = cpu_to_le32(global_seq);
1486         con->out_connect.protocol_version = cpu_to_le32(proto);
1487         con->out_connect.flags = 0;
1488 
1489         ret = get_connect_authorizer(con);
1490         if (ret)
1491                 return ret;
1492 
1493         __prepare_write_connect(con);
1494         return 0;
1495 }
1496 
1497 /*
1498  * write as much of pending kvecs to the socket as we can.
1499  *  1 -> done
1500  *  0 -> socket full, but more to do
1501  * <0 -> error
1502  */
1503 static int write_partial_kvec(struct ceph_connection *con)
1504 {
1505         int ret;
1506 
1507         dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
1508         while (con->out_kvec_bytes > 0) {
1509                 ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
1510                                        con->out_kvec_left, con->out_kvec_bytes,
1511                                        con->out_more);
1512                 if (ret <= 0)
1513                         goto out;
1514                 con->out_kvec_bytes -= ret;
1515                 if (con->out_kvec_bytes == 0)
1516                         break;            /* done */
1517 
1518                 /* account for full iov entries consumed */
1519                 while (ret >= con->out_kvec_cur->iov_len) {
1520                         BUG_ON(!con->out_kvec_left);
1521                         ret -= con->out_kvec_cur->iov_len;
1522                         con->out_kvec_cur++;
1523                         con->out_kvec_left--;
1524                 }
1525                 /* and for a partially-consumed entry */
1526                 if (ret) {
1527                         con->out_kvec_cur->iov_len -= ret;
1528                         con->out_kvec_cur->iov_base += ret;
1529                 }
1530         }
1531         con->out_kvec_left = 0;
1532         ret = 1;
1533 out:
1534         dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
1535              con->out_kvec_bytes, con->out_kvec_left, ret);
1536         return ret;  /* done! */
1537 }
1538 
1539 static u32 ceph_crc32c_page(u32 crc, struct page *page,
1540                                 unsigned int page_offset,
1541                                 unsigned int length)
1542 {
1543         char *kaddr;
1544 
1545         kaddr = kmap(page);
1546         BUG_ON(kaddr == NULL);
1547         crc = crc32c(crc, kaddr + page_offset, length);
1548         kunmap(page);
1549 
1550         return crc;
1551 }
1552 /*
1553  * Write as much message data payload as we can.  If we finish, queue
1554  * up the footer.
1555  *  1 -> done, footer is now queued in out_kvec[].
1556  *  0 -> socket full, but more to do
1557  * <0 -> error
1558  */
1559 static int write_partial_message_data(struct ceph_connection *con)
1560 {
1561         struct ceph_msg *msg = con->out_msg;
1562         struct ceph_msg_data_cursor *cursor = &msg->cursor;
1563         bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);
1564         int more = MSG_MORE | MSG_SENDPAGE_NOTLAST;
1565         u32 crc;
1566 
1567         dout("%s %p msg %p\n", __func__, con, msg);
1568 
1569         if (!msg->num_data_items)
1570                 return -EINVAL;
1571 
1572         /*
1573          * Iterate through each page that contains data to be
1574          * written, and send as much as possible for each.
1575          *
1576          * If we are calculating the data crc (the default), we will
1577          * need to map the page.  If we have no pages, they have
1578          * been revoked, so use the zero page.
1579          */
1580         crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
1581         while (cursor->total_resid) {
1582                 struct page *page;
1583                 size_t page_offset;
1584                 size_t length;
1585                 int ret;
1586 
1587                 if (!cursor->resid) {
1588                         ceph_msg_data_advance(cursor, 0);
1589                         continue;
1590                 }
1591 
1592                 page = ceph_msg_data_next(cursor, &page_offset, &length, NULL);
1593                 if (length == cursor->total_resid)
1594                         more = MSG_MORE;
1595                 ret = ceph_tcp_sendpage(con->sock, page, page_offset, length,
1596                                         more);
1597                 if (ret <= 0) {
1598                         if (do_datacrc)
1599                                 msg->footer.data_crc = cpu_to_le32(crc);
1600 
1601                         return ret;
1602                 }
1603                 if (do_datacrc && cursor->need_crc)
1604                         crc = ceph_crc32c_page(crc, page, page_offset, length);
1605                 ceph_msg_data_advance(cursor, (size_t)ret);
1606         }
1607 
1608         dout("%s %p msg %p done\n", __func__, con, msg);
1609 
1610         /* prepare and queue up footer, too */
1611         if (do_datacrc)
1612                 msg->footer.data_crc = cpu_to_le32(crc);
1613         else
1614                 msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
1615         con_out_kvec_reset(con);
1616         prepare_write_message_footer(con);
1617 
1618         return 1;       /* must return > 0 to indicate success */
1619 }
1620 
1621 /*
1622  * write some zeros
1623  */
1624 static int write_partial_skip(struct ceph_connection *con)
1625 {
1626         int more = MSG_MORE | MSG_SENDPAGE_NOTLAST;
1627         int ret;
1628 
1629         dout("%s %p %d left\n", __func__, con, con->out_skip);
1630         while (con->out_skip > 0) {
1631                 size_t size = min(con->out_skip, (int) PAGE_SIZE);
1632 
1633                 if (size == con->out_skip)
1634                         more = MSG_MORE;
1635                 ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, more);
1636                 if (ret <= 0)
1637                         goto out;
1638                 con->out_skip -= ret;
1639         }
1640         ret = 1;
1641 out:
1642         return ret;
1643 }
1644 
1645 /*
1646  * Prepare to read connection handshake, or an ack.
1647  */
1648 static void prepare_read_banner(struct ceph_connection *con)
1649 {
1650         dout("prepare_read_banner %p\n", con);
1651         con->in_base_pos = 0;
1652 }
1653 
1654 static void prepare_read_connect(struct ceph_connection *con)
1655 {
1656         dout("prepare_read_connect %p\n", con);
1657         con->in_base_pos = 0;
1658 }
1659 
1660 static void prepare_read_ack(struct ceph_connection *con)
1661 {
1662         dout("prepare_read_ack %p\n", con);
1663         con->in_base_pos = 0;
1664 }
1665 
1666 static void prepare_read_seq(struct ceph_connection *con)
1667 {
1668         dout("prepare_read_seq %p\n", con);
1669         con->in_base_pos = 0;
1670         con->in_tag = CEPH_MSGR_TAG_SEQ;
1671 }
1672 
1673 static void prepare_read_tag(struct ceph_connection *con)
1674 {
1675         dout("prepare_read_tag %p\n", con);
1676         con->in_base_pos = 0;
1677         con->in_tag = CEPH_MSGR_TAG_READY;
1678 }
1679 
1680 static void prepare_read_keepalive_ack(struct ceph_connection *con)
1681 {
1682         dout("prepare_read_keepalive_ack %p\n", con);
1683         con->in_base_pos = 0;
1684 }
1685 
1686 /*
1687  * Prepare to read a message.
1688  */
1689 static int prepare_read_message(struct ceph_connection *con)
1690 {
1691         dout("prepare_read_message %p\n", con);
1692         BUG_ON(con->in_msg != NULL);
1693         con->in_base_pos = 0;
1694         con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
1695         return 0;
1696 }
1697 
1698 
1699 static int read_partial(struct ceph_connection *con,
1700                         int end, int size, void *object)
1701 {
1702         while (con->in_base_pos < end) {
1703                 int left = end - con->in_base_pos;
1704                 int have = size - left;
1705                 int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
1706                 if (ret <= 0)
1707                         return ret;
1708                 con->in_base_pos += ret;
1709         }
1710         return 1;
1711 }
1712 
1713 
1714 /*
1715  * Read all or part of the connect-side handshake on a new connection
1716  */
1717 static int read_partial_banner(struct ceph_connection *con)
1718 {
1719         int size;
1720         int end;
1721         int ret;
1722 
1723         dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
1724 
1725         /* peer's banner */
1726         size = strlen(CEPH_BANNER);
1727         end = size;
1728         ret = read_partial(con, end, size, con->in_banner);
1729         if (ret <= 0)
1730                 goto out;
1731 
1732         size = sizeof (con->actual_peer_addr);
1733         end += size;
1734         ret = read_partial(con, end, size, &con->actual_peer_addr);
1735         if (ret <= 0)
1736                 goto out;
1737         ceph_decode_banner_addr(&con->actual_peer_addr);
1738 
1739         size = sizeof (con->peer_addr_for_me);
1740         end += size;
1741         ret = read_partial(con, end, size, &con->peer_addr_for_me);
1742         if (ret <= 0)
1743                 goto out;
1744         ceph_decode_banner_addr(&con->peer_addr_for_me);
1745 
1746 out:
1747         return ret;
1748 }
1749 
1750 static int read_partial_connect(struct ceph_connection *con)
1751 {
1752         int size;
1753         int end;
1754         int ret;
1755 
1756         dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
1757 
1758         size = sizeof (con->in_reply);
1759         end = size;
1760         ret = read_partial(con, end, size, &con->in_reply);
1761         if (ret <= 0)
1762                 goto out;
1763 
1764         if (con->auth) {
1765                 size = le32_to_cpu(con->in_reply.authorizer_len);
1766                 if (size > con->auth->authorizer_reply_buf_len) {
1767                         pr_err("authorizer reply too big: %d > %zu\n", size,
1768                                con->auth->authorizer_reply_buf_len);
1769                         ret = -EINVAL;
1770                         goto out;
1771                 }
1772 
1773                 end += size;
1774                 ret = read_partial(con, end, size,
1775                                    con->auth->authorizer_reply_buf);
1776                 if (ret <= 0)
1777                         goto out;
1778         }
1779 
1780         dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
1781              con, (int)con->in_reply.tag,
1782              le32_to_cpu(con->in_reply.connect_seq),
1783              le32_to_cpu(con->in_reply.global_seq));
1784 out:
1785         return ret;
1786 }
1787 
1788 /*
1789  * Verify the hello banner looks okay.
1790  */
1791 static int verify_hello(struct ceph_connection *con)
1792 {
1793         if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
1794                 pr_err("connect to %s got bad banner\n",
1795                        ceph_pr_addr(&con->peer_addr));
1796                 con->error_msg = "protocol error, bad banner";
1797                 return -1;
1798         }
1799         return 0;
1800 }
1801 
1802 static bool addr_is_blank(struct ceph_entity_addr *addr)
1803 {
1804         struct sockaddr_storage ss = addr->in_addr; /* align */
1805         struct in_addr *addr4 = &((struct sockaddr_in *)&ss)->sin_addr;
1806         struct in6_addr *addr6 = &((struct sockaddr_in6 *)&ss)->sin6_addr;
1807 
1808         switch (ss.ss_family) {
1809         case AF_INET:
1810                 return addr4->s_addr == htonl(INADDR_ANY);
1811         case AF_INET6:
1812                 return ipv6_addr_any(addr6);
1813         default:
1814                 return true;
1815         }
1816 }
1817 
1818 static int addr_port(struct ceph_entity_addr *addr)
1819 {
1820         switch (get_unaligned(&addr->in_addr.ss_family)) {
1821         case AF_INET:
1822                 return ntohs(get_unaligned(&((struct sockaddr_in *)&addr->in_addr)->sin_port));
1823         case AF_INET6:
1824                 return ntohs(get_unaligned(&((struct sockaddr_in6 *)&addr->in_addr)->sin6_port));
1825         }
1826         return 0;
1827 }
1828 
1829 static void addr_set_port(struct ceph_entity_addr *addr, int p)
1830 {
1831         switch (get_unaligned(&addr->in_addr.ss_family)) {
1832         case AF_INET:
1833                 put_unaligned(htons(p), &((struct sockaddr_in *)&addr->in_addr)->sin_port);
1834                 break;
1835         case AF_INET6:
1836                 put_unaligned(htons(p), &((struct sockaddr_in6 *)&addr->in_addr)->sin6_port);
1837                 break;
1838         }
1839 }
1840 
1841 /*
1842  * Unlike other *_pton function semantics, zero indicates success.
1843  */
1844 static int ceph_pton(const char *str, size_t len, struct ceph_entity_addr *addr,
1845                 char delim, const char **ipend)
1846 {
1847         memset(&addr->in_addr, 0, sizeof(addr->in_addr));
1848 
1849         if (in4_pton(str, len, (u8 *)&((struct sockaddr_in *)&addr->in_addr)->sin_addr.s_addr, delim, ipend)) {
1850                 put_unaligned(AF_INET, &addr->in_addr.ss_family);
1851                 return 0;
1852         }
1853 
1854         if (in6_pton(str, len, (u8 *)&((struct sockaddr_in6 *)&addr->in_addr)->sin6_addr.s6_addr, delim, ipend)) {
1855                 put_unaligned(AF_INET6, &addr->in_addr.ss_family);
1856                 return 0;
1857         }
1858 
1859         return -EINVAL;
1860 }
1861 
1862 /*
1863  * Extract hostname string and resolve using kernel DNS facility.
1864  */
1865 #ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
1866 static int ceph_dns_resolve_name(const char *name, size_t namelen,
1867                 struct ceph_entity_addr *addr, char delim, const char **ipend)
1868 {
1869         const char *end, *delim_p;
1870         char *colon_p, *ip_addr = NULL;
1871         int ip_len, ret;
1872 
1873         /*
1874          * The end of the hostname occurs immediately preceding the delimiter or
1875          * the port marker (':') where the delimiter takes precedence.
1876          */
1877         delim_p = memchr(name, delim, namelen);
1878         colon_p = memchr(name, ':', namelen);
1879 
1880         if (delim_p && colon_p)
1881                 end = delim_p < colon_p ? delim_p : colon_p;
1882         else if (!delim_p && colon_p)
1883                 end = colon_p;
1884         else {
1885                 end = delim_p;
1886                 if (!end) /* case: hostname:/ */
1887                         end = name + namelen;
1888         }
1889 
1890         if (end <= name)
1891                 return -EINVAL;
1892 
1893         /* do dns_resolve upcall */
1894         ip_len = dns_query(current->nsproxy->net_ns,
1895                            NULL, name, end - name, NULL, &ip_addr, NULL, false);
1896         if (ip_len > 0)
1897                 ret = ceph_pton(ip_addr, ip_len, addr, -1, NULL);
1898         else
1899                 ret = -ESRCH;
1900 
1901         kfree(ip_addr);
1902 
1903         *ipend = end;
1904 
1905         pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
1906                         ret, ret ? "failed" : ceph_pr_addr(addr));
1907 
1908         return ret;
1909 }
1910 #else
1911 static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
1912                 struct ceph_entity_addr *addr, char delim, const char **ipend)
1913 {
1914         return -EINVAL;
1915 }
1916 #endif
1917 
1918 /*
1919  * Parse a server name (IP or hostname). If a valid IP address is not found
1920  * then try to extract a hostname to resolve using userspace DNS upcall.
1921  */
1922 static int ceph_parse_server_name(const char *name, size_t namelen,
1923                 struct ceph_entity_addr *addr, char delim, const char **ipend)
1924 {
1925         int ret;
1926 
1927         ret = ceph_pton(name, namelen, addr, delim, ipend);
1928         if (ret)
1929                 ret = ceph_dns_resolve_name(name, namelen, addr, delim, ipend);
1930 
1931         return ret;
1932 }
1933 
1934 /*
1935  * Parse an ip[:port] list into an addr array.  Use the default
1936  * monitor port if a port isn't specified.
1937  */
1938 int ceph_parse_ips(const char *c, const char *end,
1939                    struct ceph_entity_addr *addr,
1940                    int max_count, int *count)
1941 {
1942         int i, ret = -EINVAL;
1943         const char *p = c;
1944 
1945         dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1946         for (i = 0; i < max_count; i++) {
1947                 const char *ipend;
1948                 int port;
1949                 char delim = ',';
1950 
1951                 if (*p == '[') {
1952                         delim = ']';
1953                         p++;
1954                 }
1955 
1956                 ret = ceph_parse_server_name(p, end - p, &addr[i], delim, &ipend);
1957                 if (ret)
1958                         goto bad;
1959                 ret = -EINVAL;
1960 
1961                 p = ipend;
1962 
1963                 if (delim == ']') {
1964                         if (*p != ']') {
1965                                 dout("missing matching ']'\n");
1966                                 goto bad;
1967                         }
1968                         p++;
1969                 }
1970 
1971                 /* port? */
1972                 if (p < end && *p == ':') {
1973                         port = 0;
1974                         p++;
1975                         while (p < end && *p >= '0' && *p <= '9') {
1976                                 port = (port * 10) + (*p - '0');
1977                                 p++;
1978                         }
1979                         if (port == 0)
1980                                 port = CEPH_MON_PORT;
1981                         else if (port > 65535)
1982                                 goto bad;
1983                 } else {
1984                         port = CEPH_MON_PORT;
1985                 }
1986 
1987                 addr_set_port(&addr[i], port);
1988                 addr[i].type = CEPH_ENTITY_ADDR_TYPE_LEGACY;
1989 
1990                 dout("parse_ips got %s\n", ceph_pr_addr(&addr[i]));
1991 
1992                 if (p == end)
1993                         break;
1994                 if (*p != ',')
1995                         goto bad;
1996                 p++;
1997         }
1998 
1999         if (p != end)
2000                 goto bad;
2001 
2002         if (count)
2003                 *count = i + 1;
2004         return 0;
2005 
2006 bad:
2007         pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
2008         return ret;
2009 }
2010 EXPORT_SYMBOL(ceph_parse_ips);
2011 
2012 static int process_banner(struct ceph_connection *con)
2013 {
2014         dout("process_banner on %p\n", con);
2015 
2016         if (verify_hello(con) < 0)
2017                 return -1;
2018 
2019         /*
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) &&
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),
2030                         (int)le32_to_cpu(con->peer_addr.nonce),
2031                         ceph_pr_addr(&con->actual_peer_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)) {
2041                 int port = addr_port(&con->msgr->inst.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, 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));
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),
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),
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));
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),
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),
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));
2988 
2989         pr_warn("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
2990                 ceph_pr_addr(&con->peer_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 void ceph_messenger_reset_nonce(struct ceph_messenger *msgr)
3035 {
3036         u32 nonce = le32_to_cpu(msgr->inst.addr.nonce) + 1000000;
3037         msgr->inst.addr.nonce = cpu_to_le32(nonce);
3038         encode_my_addr(msgr);
3039 }
3040 
3041 /*
3042  * initialize a new messenger instance
3043  */
3044 void ceph_messenger_init(struct ceph_messenger *msgr,
3045                          struct ceph_entity_addr *myaddr)
3046 {
3047         spin_lock_init(&msgr->global_seq_lock);
3048 
3049         if (myaddr)
3050                 msgr->inst.addr = *myaddr;
3051 
3052         /* select a random nonce */
3053         msgr->inst.addr.type = 0;
3054         get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
3055         encode_my_addr(msgr);
3056 
3057         atomic_set(&msgr->stopping, 0);
3058         write_pnet(&msgr->net, get_net(current->nsproxy->net_ns));
3059 
3060         dout("%s %p\n", __func__, msgr);
3061 }
3062 EXPORT_SYMBOL(ceph_messenger_init);
3063 
3064 void ceph_messenger_fini(struct ceph_messenger *msgr)
3065 {
3066         put_net(read_pnet(&msgr->net));
3067 }
3068 EXPORT_SYMBOL(ceph_messenger_fini);
3069 
3070 static void msg_con_set(struct ceph_msg *msg, struct ceph_connection *con)
3071 {
3072         if (msg->con)
3073                 msg->con->ops->put(msg->con);
3074 
3075         msg->con = con ? con->ops->get(con) : NULL;
3076         BUG_ON(msg->con != con);
3077 }
3078 
3079 static void clear_standby(struct ceph_connection *con)
3080 {
3081         /* come back from STANDBY? */
3082         if (con->state == CON_STATE_STANDBY) {
3083                 dout("clear_standby %p and ++connect_seq\n", con);
3084                 con->state = CON_STATE_PREOPEN;
3085                 con->connect_seq++;
3086                 WARN_ON(con_flag_test(con, CON_FLAG_WRITE_PENDING));
3087                 WARN_ON(con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING));
3088         }
3089 }
3090 
3091 /*
3092  * Queue up an outgoing message on the given connection.
3093  */
3094 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
3095 {
3096         /* set src+dst */
3097         msg->hdr.src = con->msgr->inst.name;
3098         BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
3099         msg->needs_out_seq = true;
3100 
3101         mutex_lock(&con->mutex);
3102 
3103         if (con->state == CON_STATE_CLOSED) {
3104                 dout("con_send %p closed, dropping %p\n", con, msg);
3105                 ceph_msg_put(msg);
3106                 mutex_unlock(&con->mutex);
3107                 return;
3108         }
3109 
3110         msg_con_set(msg, con);
3111 
3112         BUG_ON(!list_empty(&msg->list_head));
3113         list_add_tail(&msg->list_head, &con->out_queue);
3114         dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
3115              ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
3116              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
3117              le32_to_cpu(msg->hdr.front_len),
3118              le32_to_cpu(msg->hdr.middle_len),
3119              le32_to_cpu(msg->hdr.data_len));
3120 
3121         clear_standby(con);
3122         mutex_unlock(&con->mutex);
3123 
3124         /* if there wasn't anything waiting to send before, queue
3125          * new work */
3126         if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
3127                 queue_con(con);
3128 }
3129 EXPORT_SYMBOL(ceph_con_send);
3130 
3131 /*
3132  * Revoke a message that was previously queued for send
3133  */
3134 void ceph_msg_revoke(struct ceph_msg *msg)
3135 {
3136         struct ceph_connection *con = msg->con;
3137 
3138         if (!con) {
3139                 dout("%s msg %p null con\n", __func__, msg);
3140                 return;         /* Message not in our possession */
3141         }
3142 
3143         mutex_lock(&con->mutex);
3144         if (!list_empty(&msg->list_head)) {
3145                 dout("%s %p msg %p - was on queue\n", __func__, con, msg);
3146                 list_del_init(&msg->list_head);
3147                 msg->hdr.seq = 0;
3148 
3149                 ceph_msg_put(msg);
3150         }
3151         if (con->out_msg == msg) {
3152                 BUG_ON(con->out_skip);
3153                 /* footer */
3154                 if (con->out_msg_done) {
3155                         con->out_skip += con_out_kvec_skip(con);
3156                 } else {
3157                         BUG_ON(!msg->data_length);
3158                         con->out_skip += sizeof_footer(con);
3159                 }
3160                 /* data, middle, front */
3161                 if (msg->data_length)
3162                         con->out_skip += msg->cursor.total_resid;
3163                 if (msg->middle)
3164                         con->out_skip += con_out_kvec_skip(con);
3165                 con->out_skip += con_out_kvec_skip(con);
3166 
3167                 dout("%s %p msg %p - was sending, will write %d skip %d\n",
3168                      __func__, con, msg, con->out_kvec_bytes, con->out_skip);
3169                 msg->hdr.seq = 0;
3170                 con->out_msg = NULL;
3171                 ceph_msg_put(msg);
3172         }
3173 
3174         mutex_unlock(&con->mutex);
3175 }
3176 
3177 /*
3178  * Revoke a message that we may be reading data into
3179  */
3180 void ceph_msg_revoke_incoming(struct ceph_msg *msg)
3181 {
3182         struct ceph_connection *con = msg->con;
3183 
3184         if (!con) {
3185                 dout("%s msg %p null con\n", __func__, msg);
3186                 return;         /* Message not in our possession */
3187         }
3188 
3189         mutex_lock(&con->mutex);
3190         if (con->in_msg == msg) {
3191                 unsigned int front_len = le32_to_cpu(con->in_hdr.front_len);
3192                 unsigned int middle_len = le32_to_cpu(con->in_hdr.middle_len);
3193                 unsigned int data_len = le32_to_cpu(con->in_hdr.data_len);
3194 
3195                 /* skip rest of message */
3196                 dout("%s %p msg %p revoked\n", __func__, con, msg);
3197                 con->in_base_pos = con->in_base_pos -
3198                                 sizeof(struct ceph_msg_header) -
3199                                 front_len -
3200                                 middle_len -
3201                                 data_len -
3202                                 sizeof(struct ceph_msg_footer);
3203                 ceph_msg_put(con->in_msg);
3204                 con->in_msg = NULL;
3205                 con->in_tag = CEPH_MSGR_TAG_READY;
3206                 con->in_seq++;
3207         } else {
3208                 dout("%s %p in_msg %p msg %p no-op\n",
3209                      __func__, con, con->in_msg, msg);
3210         }
3211         mutex_unlock(&con->mutex);
3212 }
3213 
3214 /*
3215  * Queue a keepalive byte to ensure the tcp connection is alive.
3216  */
3217 void ceph_con_keepalive(struct ceph_connection *con)
3218 {
3219         dout("con_keepalive %p\n", con);
3220         mutex_lock(&con->mutex);
3221         clear_standby(con);
3222         con_flag_set(con, CON_FLAG_KEEPALIVE_PENDING);
3223         mutex_unlock(&con->mutex);
3224 
3225         if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
3226                 queue_con(con);
3227 }
3228 EXPORT_SYMBOL(ceph_con_keepalive);
3229 
3230 bool ceph_con_keepalive_expired(struct ceph_connection *con,
3231                                unsigned long interval)
3232 {
3233         if (interval > 0 &&
3234             (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
3235                 struct timespec64 now;
3236                 struct timespec64 ts;
3237                 ktime_get_real_ts64(&now);
3238                 jiffies_to_timespec64(interval, &ts);
3239                 ts = timespec64_add(con->last_keepalive_ack, ts);
3240                 return timespec64_compare(&now, &ts) >= 0;
3241         }
3242         return false;
3243 }
3244 
3245 static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
3246 {
3247         BUG_ON(msg->num_data_items >= msg->max_data_items);
3248         return &msg->data[msg->num_data_items++];
3249 }
3250 
3251 static void ceph_msg_data_destroy(struct ceph_msg_data *data)
3252 {
3253         if (data->type == CEPH_MSG_DATA_PAGES && data->own_pages) {
3254                 int num_pages = calc_pages_for(data->alignment, data->length);
3255                 ceph_release_page_vector(data->pages, num_pages);
3256         } else if (data->type == CEPH_MSG_DATA_PAGELIST) {
3257                 ceph_pagelist_release(data->pagelist);
3258         }
3259 }
3260 
3261 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
3262                              size_t length, size_t alignment, bool own_pages)
3263 {
3264         struct ceph_msg_data *data;
3265 
3266         BUG_ON(!pages);
3267         BUG_ON(!length);
3268 
3269         data = ceph_msg_data_add(msg);
3270         data->type = CEPH_MSG_DATA_PAGES;
3271         data->pages = pages;
3272         data->length = length;
3273         data->alignment = alignment & ~PAGE_MASK;
3274         data->own_pages = own_pages;
3275 
3276         msg->data_length += length;
3277 }
3278 EXPORT_SYMBOL(ceph_msg_data_add_pages);
3279 
3280 void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
3281                                 struct ceph_pagelist *pagelist)
3282 {
3283         struct ceph_msg_data *data;
3284 
3285         BUG_ON(!pagelist);
3286         BUG_ON(!pagelist->length);
3287 
3288         data = ceph_msg_data_add(msg);
3289         data->type = CEPH_MSG_DATA_PAGELIST;
3290         refcount_inc(&pagelist->refcnt);
3291         data->pagelist = pagelist;
3292 
3293         msg->data_length += pagelist->length;
3294 }
3295 EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
3296 
3297 #ifdef  CONFIG_BLOCK
3298 void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
3299                            u32 length)
3300 {
3301         struct ceph_msg_data *data;
3302 
3303         data = ceph_msg_data_add(msg);
3304         data->type = CEPH_MSG_DATA_BIO;
3305         data->bio_pos = *bio_pos;
3306         data->bio_length = length;
3307 
3308         msg->data_length += length;
3309 }
3310 EXPORT_SYMBOL(ceph_msg_data_add_bio);
3311 #endif  /* CONFIG_BLOCK */
3312 
3313 void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
3314                              struct ceph_bvec_iter *bvec_pos)
3315 {
3316         struct ceph_msg_data *data;
3317 
3318         data = ceph_msg_data_add(msg);
3319         data->type = CEPH_MSG_DATA_BVECS;
3320         data->bvec_pos = *bvec_pos;
3321 
3322         msg->data_length += bvec_pos->iter.bi_size;
3323 }
3324 EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
3325 
3326 /*
3327  * construct a new message with given type, size
3328  * the new msg has a ref count of 1.
3329  */
3330 struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
3331                                gfp_t flags, bool can_fail)
3332 {
3333         struct ceph_msg *m;
3334 
3335         m = kmem_cache_zalloc(ceph_msg_cache, flags);
3336         if (m == NULL)
3337                 goto out;
3338 
3339         m->hdr.type = cpu_to_le16(type);
3340         m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
3341         m->hdr.front_len = cpu_to_le32(front_len);
3342 
3343         INIT_LIST_HEAD(&m->list_head);
3344         kref_init(&m->kref);
3345 
3346         /* front */
3347         if (front_len) {
3348                 m->front.iov_base = ceph_kvmalloc(front_len, flags);
3349                 if (m->front.iov_base == NULL) {
3350                         dout("ceph_msg_new can't allocate %d bytes\n",
3351                              front_len);
3352                         goto out2;
3353                 }
3354         } else {
3355                 m->front.iov_base = NULL;
3356         }
3357         m->front_alloc_len = m->front.iov_len = front_len;
3358 
3359         if (max_data_items) {
3360                 m->data = kmalloc_array(max_data_items, sizeof(*m->data),
3361                                         flags);
3362                 if (!m->data)
3363                         goto out2;
3364 
3365                 m->max_data_items = max_data_items;
3366         }
3367 
3368         dout("ceph_msg_new %p front %d\n", m, front_len);
3369         return m;
3370 
3371 out2:
3372         ceph_msg_put(m);
3373 out:
3374         if (!can_fail) {
3375                 pr_err("msg_new can't create type %d front %d\n", type,
3376                        front_len);
3377                 WARN_ON(1);
3378         } else {
3379                 dout("msg_new can't create type %d front %d\n", type,
3380                      front_len);
3381         }
3382         return NULL;
3383 }
3384 EXPORT_SYMBOL(ceph_msg_new2);
3385 
3386 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
3387                               bool can_fail)
3388 {
3389         return ceph_msg_new2(type, front_len, 0, flags, can_fail);
3390 }
3391 EXPORT_SYMBOL(ceph_msg_new);
3392 
3393 /*
3394  * Allocate "middle" portion of a message, if it is needed and wasn't
3395  * allocated by alloc_msg.  This allows us to read a small fixed-size
3396  * per-type header in the front and then gracefully fail (i.e.,
3397  * propagate the error to the caller based on info in the front) when
3398  * the middle is too large.
3399  */
3400 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
3401 {
3402         int type = le16_to_cpu(msg->hdr.type);
3403         int middle_len = le32_to_cpu(msg->hdr.middle_len);
3404 
3405         dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
3406              ceph_msg_type_name(type), middle_len);
3407         BUG_ON(!middle_len);
3408         BUG_ON(msg->middle);
3409 
3410         msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
3411         if (!msg->middle)
3412                 return -ENOMEM;
3413         return 0;
3414 }
3415 
3416 /*
3417  * Allocate a message for receiving an incoming message on a
3418  * connection, and save the result in con->in_msg.  Uses the
3419  * connection's private alloc_msg op if available.
3420  *
3421  * Returns 0 on success, or a negative error code.
3422  *
3423  * On success, if we set *skip = 1:
3424  *  - the next message should be skipped and ignored.
3425  *  - con->in_msg == NULL
3426  * or if we set *skip = 0:
3427  *  - con->in_msg is non-null.
3428  * On error (ENOMEM, EAGAIN, ...),
3429  *  - con->in_msg == NULL
3430  */
3431 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
3432 {
3433         struct ceph_msg_header *hdr = &con->in_hdr;
3434         int middle_len = le32_to_cpu(hdr->middle_len);
3435         struct ceph_msg *msg;
3436         int ret = 0;
3437 
3438         BUG_ON(con->in_msg != NULL);
3439         BUG_ON(!con->ops->alloc_msg);
3440 
3441         mutex_unlock(&con->mutex);
3442         msg = con->ops->alloc_msg(con, hdr, skip);
3443         mutex_lock(&con->mutex);
3444         if (con->state != CON_STATE_OPEN) {
3445                 if (msg)
3446                         ceph_msg_put(msg);
3447                 return -EAGAIN;
3448         }
3449         if (msg) {
3450                 BUG_ON(*skip);
3451                 msg_con_set(msg, con);
3452                 con->in_msg = msg;
3453         } else {
3454                 /*
3455                  * Null message pointer means either we should skip
3456                  * this message or we couldn't allocate memory.  The
3457                  * former is not an error.
3458                  */
3459                 if (*skip)
3460                         return 0;
3461 
3462                 con->error_msg = "error allocating memory for incoming message";
3463                 return -ENOMEM;
3464         }
3465         memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
3466 
3467         if (middle_len && !con->in_msg->middle) {
3468                 ret = ceph_alloc_middle(con, con->in_msg);
3469                 if (ret < 0) {
3470                         ceph_msg_put(con->in_msg);
3471                         con->in_msg = NULL;
3472                 }
3473         }
3474 
3475         return ret;
3476 }
3477 
3478 
3479 /*
3480  * Free a generically kmalloc'd message.
3481  */
3482 static void ceph_msg_free(struct ceph_msg *m)
3483 {
3484         dout("%s %p\n", __func__, m);
3485         kvfree(m->front.iov_base);
3486         kfree(m->data);
3487         kmem_cache_free(ceph_msg_cache, m);
3488 }
3489 
3490 static void ceph_msg_release(struct kref *kref)
3491 {
3492         struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
3493         int i;
3494 
3495         dout("%s %p\n", __func__, m);
3496         WARN_ON(!list_empty(&m->list_head));
3497 
3498         msg_con_set(m, NULL);
3499 
3500         /* drop middle, data, if any */
3501         if (m->middle) {
3502                 ceph_buffer_put(m->middle);
3503                 m->middle = NULL;
3504         }
3505 
3506         for (i = 0; i < m->num_data_items; i++)
3507                 ceph_msg_data_destroy(&m->data[i]);
3508 
3509         if (m->pool)
3510                 ceph_msgpool_put(m->pool, m);
3511         else
3512                 ceph_msg_free(m);
3513 }
3514 
3515 struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
3516 {
3517         dout("%s %p (was %d)\n", __func__, msg,
3518              kref_read(&msg->kref));
3519         kref_get(&msg->kref);
3520         return msg;
3521 }
3522 EXPORT_SYMBOL(ceph_msg_get);
3523 
3524 void ceph_msg_put(struct ceph_msg *msg)
3525 {
3526         dout("%s %p (was %d)\n", __func__, msg,
3527              kref_read(&msg->kref));
3528         kref_put(&msg->kref, ceph_msg_release);
3529 }
3530 EXPORT_SYMBOL(ceph_msg_put);
3531 
3532 void ceph_msg_dump(struct ceph_msg *msg)
3533 {
3534         pr_debug("msg_dump %p (front_alloc_len %d length %zd)\n", msg,
3535                  msg->front_alloc_len, msg->data_length);
3536         print_hex_dump(KERN_DEBUG, "header: ",
3537                        DUMP_PREFIX_OFFSET, 16, 1,
3538                        &msg->hdr, sizeof(msg->hdr), true);
3539         print_hex_dump(KERN_DEBUG, " front: ",
3540                        DUMP_PREFIX_OFFSET, 16, 1,
3541                        msg->front.iov_base, msg->front.iov_len, true);
3542         if (msg->middle)
3543                 print_hex_dump(KERN_DEBUG, "middle: ",
3544                                DUMP_PREFIX_OFFSET, 16, 1,
3545                                msg->middle->vec.iov_base,
3546                                msg->middle->vec.iov_len, true);
3547         print_hex_dump(KERN_DEBUG, "footer: ",
3548                        DUMP_PREFIX_OFFSET, 16, 1,
3549                        &msg->footer, sizeof(msg->footer), true);
3550 }
3551 EXPORT_SYMBOL(ceph_msg_dump);
/* [<][>][^][v][top][bottom][index][help] */
root/net/ceph/messenger.c

DEFINITIONS
