1 /* 2 * linux/net/sunrpc/clnt.c 3 * 4 * This file contains the high-level RPC interface. 5 * It is modeled as a finite state machine to support both synchronous 6 * and asynchronous requests. 7 * 8 * - RPC header generation and argument serialization. 9 * - Credential refresh. 10 * - TCP connect handling. 11 * - Retry of operation when it is suspected the operation failed because 12 * of uid squashing on the server, or when the credentials were stale 13 * and need to be refreshed, or when a packet was damaged in transit. 14 * This may be have to be moved to the VFS layer. 15 * 16 * NB: BSD uses a more intelligent approach to guessing when a request 17 * or reply has been lost by keeping the RTO estimate for each procedure. 18 * We currently make do with a constant timeout value. 19 * 20 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com> 21 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de> 22 */ 23 24 #include <asm/system.h> 25 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/mm.h> 29 #include <linux/slab.h> 30 #include <linux/smp_lock.h> 31 #include <linux/utsname.h> 32 #include <linux/workqueue.h> 33 34 #include <linux/sunrpc/clnt.h> 35 #include <linux/sunrpc/rpc_pipe_fs.h> 36 #include <linux/sunrpc/metrics.h> 37 38 39 #define RPC_SLACK_SPACE (1024) /* total overkill */ 40 41 #ifdef RPC_DEBUG 42 # define RPCDBG_FACILITY RPCDBG_CALL 43 #endif 44 45 #define dprint_status(t) \ 46 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \ 47 __FUNCTION__, t->tk_status) 48 49 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); 50 51 52 static void call_start(struct rpc_task *task); 53 static void call_reserve(struct rpc_task *task); 54 static void call_reserveresult(struct rpc_task *task); 55 static void call_allocate(struct rpc_task *task); 56 static void call_encode(struct rpc_task *task); 57 static void call_decode(struct rpc_task *task); 58 static void call_bind(struct rpc_task *task); 59 static void call_bind_status(struct rpc_task *task); 60 static void call_transmit(struct rpc_task *task); 61 static void call_status(struct rpc_task *task); 62 static void call_transmit_status(struct rpc_task *task); 63 static void call_refresh(struct rpc_task *task); 64 static void call_refreshresult(struct rpc_task *task); 65 static void call_timeout(struct rpc_task *task); 66 static void call_connect(struct rpc_task *task); 67 static void call_connect_status(struct rpc_task *task); 68 static __be32 * call_header(struct rpc_task *task); 69 static __be32 * call_verify(struct rpc_task *task); 70 71 72 static int 73 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name) 74 { 75 static uint32_t clntid; 76 int error; 77 78 clnt->cl_vfsmnt = ERR_PTR(-ENOENT); 79 clnt->cl_dentry = ERR_PTR(-ENOENT); 80 if (dir_name == NULL) 81 return 0; 82 83 clnt->cl_vfsmnt = rpc_get_mount(); 84 if (IS_ERR(clnt->cl_vfsmnt)) 85 return PTR_ERR(clnt->cl_vfsmnt); 86 87 for (;;) { 88 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname), 89 "%s/clnt%x", dir_name, 90 (unsigned int)clntid++); 91 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0'; 92 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt); 93 if (!IS_ERR(clnt->cl_dentry)) 94 return 0; 95 error = PTR_ERR(clnt->cl_dentry); 96 if (error != -EEXIST) { 97 printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n", 98 clnt->cl_pathname, error); 99 rpc_put_mount(); 100 return error; 101 } 102 } 103 } 104 105 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor) 106 { 107 struct rpc_version *version; 108 struct rpc_clnt *clnt = NULL; 109 struct rpc_auth *auth; 110 int err; 111 int len; 112 113 dprintk("RPC: creating %s client for %s (xprt %p)\n", 114 program->name, servname, xprt); 115 116 err = -EINVAL; 117 if (!xprt) 118 goto out_no_xprt; 119 if (vers >= program->nrvers || !(version = program->version[vers])) 120 goto out_err; 121 122 err = -ENOMEM; 123 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 124 if (!clnt) 125 goto out_err; 126 atomic_set(&clnt->cl_users, 0); 127 atomic_set(&clnt->cl_count, 1); 128 clnt->cl_parent = clnt; 129 130 clnt->cl_server = clnt->cl_inline_name; 131 len = strlen(servname) + 1; 132 if (len > sizeof(clnt->cl_inline_name)) { 133 char *buf = kmalloc(len, GFP_KERNEL); 134 if (buf != 0) 135 clnt->cl_server = buf; 136 else 137 len = sizeof(clnt->cl_inline_name); 138 } 139 strlcpy(clnt->cl_server, servname, len); 140 141 clnt->cl_xprt = xprt; 142 clnt->cl_procinfo = version->procs; 143 clnt->cl_maxproc = version->nrprocs; 144 clnt->cl_protname = program->name; 145 clnt->cl_prog = program->number; 146 clnt->cl_vers = version->number; 147 clnt->cl_stats = program->stats; 148 clnt->cl_metrics = rpc_alloc_iostats(clnt); 149 err = -ENOMEM; 150 if (clnt->cl_metrics == NULL) 151 goto out_no_stats; 152 clnt->cl_program = program; 153 154 if (!xprt_bound(clnt->cl_xprt)) 155 clnt->cl_autobind = 1; 156 157 clnt->cl_rtt = &clnt->cl_rtt_default; 158 rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval); 159 160 err = rpc_setup_pipedir(clnt, program->pipe_dir_name); 161 if (err < 0) 162 goto out_no_path; 163 164 auth = rpcauth_create(flavor, clnt); 165 if (IS_ERR(auth)) { 166 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n", 167 flavor); 168 err = PTR_ERR(auth); 169 goto out_no_auth; 170 } 171 172 /* save the nodename */ 173 clnt->cl_nodelen = strlen(utsname()->nodename); 174 if (clnt->cl_nodelen > UNX_MAXNODENAME) 175 clnt->cl_nodelen = UNX_MAXNODENAME; 176 memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen); 177 return clnt; 178 179 out_no_auth: 180 if (!IS_ERR(clnt->cl_dentry)) { 181 rpc_rmdir(clnt->cl_dentry); 182 rpc_put_mount(); 183 } 184 out_no_path: 185 rpc_free_iostats(clnt->cl_metrics); 186 out_no_stats: 187 if (clnt->cl_server != clnt->cl_inline_name) 188 kfree(clnt->cl_server); 189 kfree(clnt); 190 out_err: 191 xprt_put(xprt); 192 out_no_xprt: 193 return ERR_PTR(err); 194 } 195 196 /* 197 * rpc_create - create an RPC client and transport with one call 198 * @args: rpc_clnt create argument structure 199 * 200 * Creates and initializes an RPC transport and an RPC client. 201 * 202 * It can ping the server in order to determine if it is up, and to see if 203 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables 204 * this behavior so asynchronous tasks can also use rpc_create. 205 */ 206 struct rpc_clnt *rpc_create(struct rpc_create_args *args) 207 { 208 struct rpc_xprt *xprt; 209 struct rpc_clnt *clnt; 210 211 xprt = xprt_create_transport(args->protocol, args->address, 212 args->addrsize, args->timeout); 213 if (IS_ERR(xprt)) 214 return (struct rpc_clnt *)xprt; 215 216 /* 217 * By default, kernel RPC client connects from a reserved port. 218 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters, 219 * but it is always enabled for rpciod, which handles the connect 220 * operation. 221 */ 222 xprt->resvport = 1; 223 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) 224 xprt->resvport = 0; 225 226 dprintk("RPC: creating %s client for %s (xprt %p)\n", 227 args->program->name, args->servername, xprt); 228 229 clnt = rpc_new_client(xprt, args->servername, args->program, 230 args->version, args->authflavor); 231 if (IS_ERR(clnt)) 232 return clnt; 233 234 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) { 235 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 236 if (err != 0) { 237 rpc_shutdown_client(clnt); 238 return ERR_PTR(err); 239 } 240 } 241 242 clnt->cl_softrtry = 1; 243 if (args->flags & RPC_CLNT_CREATE_HARDRTRY) 244 clnt->cl_softrtry = 0; 245 246 if (args->flags & RPC_CLNT_CREATE_INTR) 247 clnt->cl_intr = 1; 248 if (args->flags & RPC_CLNT_CREATE_AUTOBIND) 249 clnt->cl_autobind = 1; 250 if (args->flags & RPC_CLNT_CREATE_ONESHOT) 251 clnt->cl_oneshot = 1; 252 if (args->flags & RPC_CLNT_CREATE_DISCRTRY) 253 clnt->cl_discrtry = 1; 254 255 return clnt; 256 } 257 EXPORT_SYMBOL_GPL(rpc_create); 258 259 /* 260 * This function clones the RPC client structure. It allows us to share the 261 * same transport while varying parameters such as the authentication 262 * flavour. 263 */ 264 struct rpc_clnt * 265 rpc_clone_client(struct rpc_clnt *clnt) 266 { 267 struct rpc_clnt *new; 268 int err = -ENOMEM; 269 270 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL); 271 if (!new) 272 goto out_no_clnt; 273 atomic_set(&new->cl_count, 1); 274 atomic_set(&new->cl_users, 0); 275 new->cl_metrics = rpc_alloc_iostats(clnt); 276 if (new->cl_metrics == NULL) 277 goto out_no_stats; 278 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name); 279 if (err != 0) 280 goto out_no_path; 281 new->cl_parent = clnt; 282 atomic_inc(&clnt->cl_count); 283 new->cl_xprt = xprt_get(clnt->cl_xprt); 284 /* Turn off autobind on clones */ 285 new->cl_autobind = 0; 286 new->cl_oneshot = 0; 287 new->cl_dead = 0; 288 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval); 289 if (new->cl_auth) 290 atomic_inc(&new->cl_auth->au_count); 291 return new; 292 out_no_path: 293 rpc_free_iostats(new->cl_metrics); 294 out_no_stats: 295 kfree(new); 296 out_no_clnt: 297 dprintk("RPC: %s: returned error %d\n", __FUNCTION__, err); 298 return ERR_PTR(err); 299 } 300 301 /* 302 * Properly shut down an RPC client, terminating all outstanding 303 * requests. Note that we must be certain that cl_oneshot and 304 * cl_dead are cleared, or else the client would be destroyed 305 * when the last task releases it. 306 */ 307 int 308 rpc_shutdown_client(struct rpc_clnt *clnt) 309 { 310 dprintk("RPC: shutting down %s client for %s, tasks=%d\n", 311 clnt->cl_protname, clnt->cl_server, 312 atomic_read(&clnt->cl_users)); 313 314 while (atomic_read(&clnt->cl_users) > 0) { 315 /* Don't let rpc_release_client destroy us */ 316 clnt->cl_oneshot = 0; 317 clnt->cl_dead = 0; 318 rpc_killall_tasks(clnt); 319 wait_event_timeout(destroy_wait, 320 !atomic_read(&clnt->cl_users), 1*HZ); 321 } 322 323 if (atomic_read(&clnt->cl_users) < 0) { 324 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n", 325 clnt, atomic_read(&clnt->cl_users)); 326 #ifdef RPC_DEBUG 327 rpc_show_tasks(); 328 #endif 329 BUG(); 330 } 331 332 return rpc_destroy_client(clnt); 333 } 334 335 /* 336 * Delete an RPC client 337 */ 338 int 339 rpc_destroy_client(struct rpc_clnt *clnt) 340 { 341 if (!atomic_dec_and_test(&clnt->cl_count)) 342 return 1; 343 BUG_ON(atomic_read(&clnt->cl_users) != 0); 344 345 dprintk("RPC: destroying %s client for %s\n", 346 clnt->cl_protname, clnt->cl_server); 347 if (clnt->cl_auth) { 348 rpcauth_destroy(clnt->cl_auth); 349 clnt->cl_auth = NULL; 350 } 351 if (!IS_ERR(clnt->cl_dentry)) { 352 rpc_rmdir(clnt->cl_dentry); 353 rpc_put_mount(); 354 } 355 if (clnt->cl_parent != clnt) { 356 rpc_destroy_client(clnt->cl_parent); 357 goto out_free; 358 } 359 if (clnt->cl_server != clnt->cl_inline_name) 360 kfree(clnt->cl_server); 361 out_free: 362 rpc_free_iostats(clnt->cl_metrics); 363 clnt->cl_metrics = NULL; 364 xprt_put(clnt->cl_xprt); 365 kfree(clnt); 366 return 0; 367 } 368 369 /* 370 * Release an RPC client 371 */ 372 void 373 rpc_release_client(struct rpc_clnt *clnt) 374 { 375 dprintk("RPC: rpc_release_client(%p, %d)\n", 376 clnt, atomic_read(&clnt->cl_users)); 377 378 if (!atomic_dec_and_test(&clnt->cl_users)) 379 return; 380 wake_up(&destroy_wait); 381 if (clnt->cl_oneshot || clnt->cl_dead) 382 rpc_destroy_client(clnt); 383 } 384 385 /** 386 * rpc_bind_new_program - bind a new RPC program to an existing client 387 * @old - old rpc_client 388 * @program - rpc program to set 389 * @vers - rpc program version 390 * 391 * Clones the rpc client and sets up a new RPC program. This is mainly 392 * of use for enabling different RPC programs to share the same transport. 393 * The Sun NFSv2/v3 ACL protocol can do this. 394 */ 395 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old, 396 struct rpc_program *program, 397 int vers) 398 { 399 struct rpc_clnt *clnt; 400 struct rpc_version *version; 401 int err; 402 403 BUG_ON(vers >= program->nrvers || !program->version[vers]); 404 version = program->version[vers]; 405 clnt = rpc_clone_client(old); 406 if (IS_ERR(clnt)) 407 goto out; 408 clnt->cl_procinfo = version->procs; 409 clnt->cl_maxproc = version->nrprocs; 410 clnt->cl_protname = program->name; 411 clnt->cl_prog = program->number; 412 clnt->cl_vers = version->number; 413 clnt->cl_stats = program->stats; 414 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 415 if (err != 0) { 416 rpc_shutdown_client(clnt); 417 clnt = ERR_PTR(err); 418 } 419 out: 420 return clnt; 421 } 422 423 /* 424 * Default callback for async RPC calls 425 */ 426 static void 427 rpc_default_callback(struct rpc_task *task, void *data) 428 { 429 } 430 431 static const struct rpc_call_ops rpc_default_ops = { 432 .rpc_call_done = rpc_default_callback, 433 }; 434 435 /* 436 * Export the signal mask handling for synchronous code that 437 * sleeps on RPC calls 438 */ 439 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM)) 440 441 static void rpc_save_sigmask(sigset_t *oldset, int intr) 442 { 443 unsigned long sigallow = sigmask(SIGKILL); 444 sigset_t sigmask; 445 446 /* Block all signals except those listed in sigallow */ 447 if (intr) 448 sigallow |= RPC_INTR_SIGNALS; 449 siginitsetinv(&sigmask, sigallow); 450 sigprocmask(SIG_BLOCK, &sigmask, oldset); 451 } 452 453 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset) 454 { 455 rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task)); 456 } 457 458 static inline void rpc_restore_sigmask(sigset_t *oldset) 459 { 460 sigprocmask(SIG_SETMASK, oldset, NULL); 461 } 462 463 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset) 464 { 465 rpc_save_sigmask(oldset, clnt->cl_intr); 466 } 467 468 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset) 469 { 470 rpc_restore_sigmask(oldset); 471 } 472 473 /* 474 * New rpc_call implementation 475 */ 476 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags) 477 { 478 struct rpc_task *task; 479 sigset_t oldset; 480 int status; 481 482 /* If this client is slain all further I/O fails */ 483 if (clnt->cl_dead) 484 return -EIO; 485 486 BUG_ON(flags & RPC_TASK_ASYNC); 487 488 task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL); 489 if (task == NULL) 490 return -ENOMEM; 491 492 /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */ 493 rpc_task_sigmask(task, &oldset); 494 495 /* Set up the call info struct and execute the task */ 496 rpc_call_setup(task, msg, 0); 497 if (task->tk_status == 0) { 498 atomic_inc(&task->tk_count); 499 rpc_execute(task); 500 } 501 status = task->tk_status; 502 rpc_put_task(task); 503 rpc_restore_sigmask(&oldset); 504 return status; 505 } 506 507 /* 508 * New rpc_call implementation 509 */ 510 int 511 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags, 512 const struct rpc_call_ops *tk_ops, void *data) 513 { 514 struct rpc_task *task; 515 sigset_t oldset; 516 int status; 517 518 /* If this client is slain all further I/O fails */ 519 status = -EIO; 520 if (clnt->cl_dead) 521 goto out_release; 522 523 flags |= RPC_TASK_ASYNC; 524 525 /* Create/initialize a new RPC task */ 526 status = -ENOMEM; 527 if (!(task = rpc_new_task(clnt, flags, tk_ops, data))) 528 goto out_release; 529 530 /* Mask signals on GSS_AUTH upcalls */ 531 rpc_task_sigmask(task, &oldset); 532 533 rpc_call_setup(task, msg, 0); 534 535 /* Set up the call info struct and execute the task */ 536 status = task->tk_status; 537 if (status == 0) 538 rpc_execute(task); 539 else 540 rpc_put_task(task); 541 542 rpc_restore_sigmask(&oldset); 543 return status; 544 out_release: 545 rpc_release_calldata(tk_ops, data); 546 return status; 547 } 548 549 550 void 551 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags) 552 { 553 task->tk_msg = *msg; 554 task->tk_flags |= flags; 555 /* Bind the user cred */ 556 if (task->tk_msg.rpc_cred != NULL) 557 rpcauth_holdcred(task); 558 else 559 rpcauth_bindcred(task); 560 561 if (task->tk_status == 0) 562 task->tk_action = call_start; 563 else 564 task->tk_action = rpc_exit_task; 565 } 566 567 /** 568 * rpc_peeraddr - extract remote peer address from clnt's xprt 569 * @clnt: RPC client structure 570 * @buf: target buffer 571 * @size: length of target buffer 572 * 573 * Returns the number of bytes that are actually in the stored address. 574 */ 575 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize) 576 { 577 size_t bytes; 578 struct rpc_xprt *xprt = clnt->cl_xprt; 579 580 bytes = sizeof(xprt->addr); 581 if (bytes > bufsize) 582 bytes = bufsize; 583 memcpy(buf, &clnt->cl_xprt->addr, bytes); 584 return xprt->addrlen; 585 } 586 EXPORT_SYMBOL_GPL(rpc_peeraddr); 587 588 /** 589 * rpc_peeraddr2str - return remote peer address in printable format 590 * @clnt: RPC client structure 591 * @format: address format 592 * 593 */ 594 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format) 595 { 596 struct rpc_xprt *xprt = clnt->cl_xprt; 597 598 if (xprt->address_strings[format] != NULL) 599 return xprt->address_strings[format]; 600 else 601 return "unprintable"; 602 } 603 EXPORT_SYMBOL_GPL(rpc_peeraddr2str); 604 605 void 606 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 607 { 608 struct rpc_xprt *xprt = clnt->cl_xprt; 609 if (xprt->ops->set_buffer_size) 610 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 611 } 612 613 /* 614 * Return size of largest payload RPC client can support, in bytes 615 * 616 * For stream transports, this is one RPC record fragment (see RFC 617 * 1831), as we don't support multi-record requests yet. For datagram 618 * transports, this is the size of an IP packet minus the IP, UDP, and 619 * RPC header sizes. 620 */ 621 size_t rpc_max_payload(struct rpc_clnt *clnt) 622 { 623 return clnt->cl_xprt->max_payload; 624 } 625 EXPORT_SYMBOL_GPL(rpc_max_payload); 626 627 /** 628 * rpc_force_rebind - force transport to check that remote port is unchanged 629 * @clnt: client to rebind 630 * 631 */ 632 void rpc_force_rebind(struct rpc_clnt *clnt) 633 { 634 if (clnt->cl_autobind) 635 xprt_clear_bound(clnt->cl_xprt); 636 } 637 EXPORT_SYMBOL_GPL(rpc_force_rebind); 638 639 /* 640 * Restart an (async) RPC call. Usually called from within the 641 * exit handler. 642 */ 643 void 644 rpc_restart_call(struct rpc_task *task) 645 { 646 if (RPC_ASSASSINATED(task)) 647 return; 648 649 task->tk_action = call_start; 650 } 651 652 /* 653 * 0. Initial state 654 * 655 * Other FSM states can be visited zero or more times, but 656 * this state is visited exactly once for each RPC. 657 */ 658 static void 659 call_start(struct rpc_task *task) 660 { 661 struct rpc_clnt *clnt = task->tk_client; 662 663 dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid, 664 clnt->cl_protname, clnt->cl_vers, 665 task->tk_msg.rpc_proc->p_proc, 666 (RPC_IS_ASYNC(task) ? "async" : "sync")); 667 668 /* Increment call count */ 669 task->tk_msg.rpc_proc->p_count++; 670 clnt->cl_stats->rpccnt++; 671 task->tk_action = call_reserve; 672 } 673 674 /* 675 * 1. Reserve an RPC call slot 676 */ 677 static void 678 call_reserve(struct rpc_task *task) 679 { 680 dprint_status(task); 681 682 if (!rpcauth_uptodatecred(task)) { 683 task->tk_action = call_refresh; 684 return; 685 } 686 687 task->tk_status = 0; 688 task->tk_action = call_reserveresult; 689 xprt_reserve(task); 690 } 691 692 /* 693 * 1b. Grok the result of xprt_reserve() 694 */ 695 static void 696 call_reserveresult(struct rpc_task *task) 697 { 698 int status = task->tk_status; 699 700 dprint_status(task); 701 702 /* 703 * After a call to xprt_reserve(), we must have either 704 * a request slot or else an error status. 705 */ 706 task->tk_status = 0; 707 if (status >= 0) { 708 if (task->tk_rqstp) { 709 task->tk_action = call_allocate; 710 return; 711 } 712 713 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 714 __FUNCTION__, status); 715 rpc_exit(task, -EIO); 716 return; 717 } 718 719 /* 720 * Even though there was an error, we may have acquired 721 * a request slot somehow. Make sure not to leak it. 722 */ 723 if (task->tk_rqstp) { 724 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 725 __FUNCTION__, status); 726 xprt_release(task); 727 } 728 729 switch (status) { 730 case -EAGAIN: /* woken up; retry */ 731 task->tk_action = call_reserve; 732 return; 733 case -EIO: /* probably a shutdown */ 734 break; 735 default: 736 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 737 __FUNCTION__, status); 738 break; 739 } 740 rpc_exit(task, status); 741 } 742 743 /* 744 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. 745 * (Note: buffer memory is freed in xprt_release). 746 */ 747 static void 748 call_allocate(struct rpc_task *task) 749 { 750 struct rpc_rqst *req = task->tk_rqstp; 751 struct rpc_xprt *xprt = task->tk_xprt; 752 unsigned int bufsiz; 753 754 dprint_status(task); 755 756 task->tk_action = call_bind; 757 if (req->rq_buffer) 758 return; 759 760 /* FIXME: compute buffer requirements more exactly using 761 * auth->au_wslack */ 762 bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE; 763 764 if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL) 765 return; 766 767 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid); 768 769 if (RPC_IS_ASYNC(task) || !signalled()) { 770 xprt_release(task); 771 task->tk_action = call_reserve; 772 rpc_delay(task, HZ>>4); 773 return; 774 } 775 776 rpc_exit(task, -ERESTARTSYS); 777 } 778 779 static inline int 780 rpc_task_need_encode(struct rpc_task *task) 781 { 782 return task->tk_rqstp->rq_snd_buf.len == 0; 783 } 784 785 static inline void 786 rpc_task_force_reencode(struct rpc_task *task) 787 { 788 task->tk_rqstp->rq_snd_buf.len = 0; 789 } 790 791 /* 792 * 3. Encode arguments of an RPC call 793 */ 794 static void 795 call_encode(struct rpc_task *task) 796 { 797 struct rpc_rqst *req = task->tk_rqstp; 798 struct xdr_buf *sndbuf = &req->rq_snd_buf; 799 struct xdr_buf *rcvbuf = &req->rq_rcv_buf; 800 unsigned int bufsiz; 801 kxdrproc_t encode; 802 __be32 *p; 803 804 dprint_status(task); 805 806 /* Default buffer setup */ 807 bufsiz = req->rq_bufsize >> 1; 808 sndbuf->head[0].iov_base = (void *)req->rq_buffer; 809 sndbuf->head[0].iov_len = bufsiz; 810 sndbuf->tail[0].iov_len = 0; 811 sndbuf->page_len = 0; 812 sndbuf->len = 0; 813 sndbuf->buflen = bufsiz; 814 rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz); 815 rcvbuf->head[0].iov_len = bufsiz; 816 rcvbuf->tail[0].iov_len = 0; 817 rcvbuf->page_len = 0; 818 rcvbuf->len = 0; 819 rcvbuf->buflen = bufsiz; 820 821 /* Encode header and provided arguments */ 822 encode = task->tk_msg.rpc_proc->p_encode; 823 if (!(p = call_header(task))) { 824 printk(KERN_INFO "RPC: call_header failed, exit EIO\n"); 825 rpc_exit(task, -EIO); 826 return; 827 } 828 if (encode == NULL) 829 return; 830 831 lock_kernel(); 832 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 833 task->tk_msg.rpc_argp); 834 unlock_kernel(); 835 if (task->tk_status == -ENOMEM) { 836 /* XXX: Is this sane? */ 837 rpc_delay(task, 3*HZ); 838 task->tk_status = -EAGAIN; 839 } 840 } 841 842 /* 843 * 4. Get the server port number if not yet set 844 */ 845 static void 846 call_bind(struct rpc_task *task) 847 { 848 struct rpc_xprt *xprt = task->tk_xprt; 849 850 dprint_status(task); 851 852 task->tk_action = call_connect; 853 if (!xprt_bound(xprt)) { 854 task->tk_action = call_bind_status; 855 task->tk_timeout = xprt->bind_timeout; 856 xprt->ops->rpcbind(task); 857 } 858 } 859 860 /* 861 * 4a. Sort out bind result 862 */ 863 static void 864 call_bind_status(struct rpc_task *task) 865 { 866 int status = -EACCES; 867 868 if (task->tk_status >= 0) { 869 dprint_status(task); 870 task->tk_status = 0; 871 task->tk_action = call_connect; 872 return; 873 } 874 875 switch (task->tk_status) { 876 case -EACCES: 877 dprintk("RPC: %5u remote rpcbind: RPC program/version " 878 "unavailable\n", task->tk_pid); 879 rpc_delay(task, 3*HZ); 880 goto retry_timeout; 881 case -ETIMEDOUT: 882 dprintk("RPC: %5u rpcbind request timed out\n", 883 task->tk_pid); 884 goto retry_timeout; 885 case -EPFNOSUPPORT: 886 dprintk("RPC: %5u remote rpcbind service unavailable\n", 887 task->tk_pid); 888 break; 889 case -EPROTONOSUPPORT: 890 dprintk("RPC: %5u remote rpcbind version 2 unavailable\n", 891 task->tk_pid); 892 break; 893 default: 894 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n", 895 task->tk_pid, -task->tk_status); 896 status = -EIO; 897 } 898 899 rpc_exit(task, status); 900 return; 901 902 retry_timeout: 903 task->tk_action = call_timeout; 904 } 905 906 /* 907 * 4b. Connect to the RPC server 908 */ 909 static void 910 call_connect(struct rpc_task *task) 911 { 912 struct rpc_xprt *xprt = task->tk_xprt; 913 914 dprintk("RPC: %5u call_connect xprt %p %s connected\n", 915 task->tk_pid, xprt, 916 (xprt_connected(xprt) ? "is" : "is not")); 917 918 task->tk_action = call_transmit; 919 if (!xprt_connected(xprt)) { 920 task->tk_action = call_connect_status; 921 if (task->tk_status < 0) 922 return; 923 xprt_connect(task); 924 } 925 } 926 927 /* 928 * 4c. Sort out connect result 929 */ 930 static void 931 call_connect_status(struct rpc_task *task) 932 { 933 struct rpc_clnt *clnt = task->tk_client; 934 int status = task->tk_status; 935 936 dprint_status(task); 937 938 task->tk_status = 0; 939 if (status >= 0) { 940 clnt->cl_stats->netreconn++; 941 task->tk_action = call_transmit; 942 return; 943 } 944 945 /* Something failed: remote service port may have changed */ 946 rpc_force_rebind(clnt); 947 948 switch (status) { 949 case -ENOTCONN: 950 case -EAGAIN: 951 task->tk_action = call_bind; 952 if (!RPC_IS_SOFT(task)) 953 return; 954 /* if soft mounted, test if we've timed out */ 955 case -ETIMEDOUT: 956 task->tk_action = call_timeout; 957 return; 958 } 959 rpc_exit(task, -EIO); 960 } 961 962 /* 963 * 5. Transmit the RPC request, and wait for reply 964 */ 965 static void 966 call_transmit(struct rpc_task *task) 967 { 968 dprint_status(task); 969 970 task->tk_action = call_status; 971 if (task->tk_status < 0) 972 return; 973 task->tk_status = xprt_prepare_transmit(task); 974 if (task->tk_status != 0) 975 return; 976 task->tk_action = call_transmit_status; 977 /* Encode here so that rpcsec_gss can use correct sequence number. */ 978 if (rpc_task_need_encode(task)) { 979 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0); 980 call_encode(task); 981 /* Did the encode result in an error condition? */ 982 if (task->tk_status != 0) 983 return; 984 } 985 xprt_transmit(task); 986 if (task->tk_status < 0) 987 return; 988 /* 989 * On success, ensure that we call xprt_end_transmit() before sleeping 990 * in order to allow access to the socket to other RPC requests. 991 */ 992 call_transmit_status(task); 993 if (task->tk_msg.rpc_proc->p_decode != NULL) 994 return; 995 task->tk_action = rpc_exit_task; 996 rpc_wake_up_task(task); 997 } 998 999 /* 1000 * 5a. Handle cleanup after a transmission 1001 */ 1002 static void 1003 call_transmit_status(struct rpc_task *task) 1004 { 1005 task->tk_action = call_status; 1006 /* 1007 * Special case: if we've been waiting on the socket's write_space() 1008 * callback, then don't call xprt_end_transmit(). 1009 */ 1010 if (task->tk_status == -EAGAIN) 1011 return; 1012 xprt_end_transmit(task); 1013 rpc_task_force_reencode(task); 1014 } 1015 1016 /* 1017 * 6. Sort out the RPC call status 1018 */ 1019 static void 1020 call_status(struct rpc_task *task) 1021 { 1022 struct rpc_clnt *clnt = task->tk_client; 1023 struct rpc_rqst *req = task->tk_rqstp; 1024 int status; 1025 1026 if (req->rq_received > 0 && !req->rq_bytes_sent) 1027 task->tk_status = req->rq_received; 1028 1029 dprint_status(task); 1030 1031 status = task->tk_status; 1032 if (status >= 0) { 1033 task->tk_action = call_decode; 1034 return; 1035 } 1036 1037 task->tk_status = 0; 1038 switch(status) { 1039 case -EHOSTDOWN: 1040 case -EHOSTUNREACH: 1041 case -ENETUNREACH: 1042 /* 1043 * Delay any retries for 3 seconds, then handle as if it 1044 * were a timeout. 1045 */ 1046 rpc_delay(task, 3*HZ); 1047 case -ETIMEDOUT: 1048 task->tk_action = call_timeout; 1049 break; 1050 case -ECONNREFUSED: 1051 case -ENOTCONN: 1052 rpc_force_rebind(clnt); 1053 task->tk_action = call_bind; 1054 break; 1055 case -EAGAIN: 1056 task->tk_action = call_transmit; 1057 break; 1058 case -EIO: 1059 /* shutdown or soft timeout */ 1060 rpc_exit(task, status); 1061 break; 1062 default: 1063 printk("%s: RPC call returned error %d\n", 1064 clnt->cl_protname, -status); 1065 rpc_exit(task, status); 1066 } 1067 } 1068 1069 /* 1070 * 6a. Handle RPC timeout 1071 * We do not release the request slot, so we keep using the 1072 * same XID for all retransmits. 1073 */ 1074 static void 1075 call_timeout(struct rpc_task *task) 1076 { 1077 struct rpc_clnt *clnt = task->tk_client; 1078 1079 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 1080 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid); 1081 goto retry; 1082 } 1083 1084 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid); 1085 task->tk_timeouts++; 1086 1087 if (RPC_IS_SOFT(task)) { 1088 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 1089 clnt->cl_protname, clnt->cl_server); 1090 rpc_exit(task, -EIO); 1091 return; 1092 } 1093 1094 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 1095 task->tk_flags |= RPC_CALL_MAJORSEEN; 1096 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 1097 clnt->cl_protname, clnt->cl_server); 1098 } 1099 rpc_force_rebind(clnt); 1100 1101 retry: 1102 clnt->cl_stats->rpcretrans++; 1103 task->tk_action = call_bind; 1104 task->tk_status = 0; 1105 } 1106 1107 /* 1108 * 7. Decode the RPC reply 1109 */ 1110 static void 1111 call_decode(struct rpc_task *task) 1112 { 1113 struct rpc_clnt *clnt = task->tk_client; 1114 struct rpc_rqst *req = task->tk_rqstp; 1115 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode; 1116 __be32 *p; 1117 1118 dprintk("RPC: %5u call_decode (status %d)\n", 1119 task->tk_pid, task->tk_status); 1120 1121 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 1122 printk(KERN_NOTICE "%s: server %s OK\n", 1123 clnt->cl_protname, clnt->cl_server); 1124 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 1125 } 1126 1127 if (task->tk_status < 12) { 1128 if (!RPC_IS_SOFT(task)) { 1129 task->tk_action = call_bind; 1130 clnt->cl_stats->rpcretrans++; 1131 goto out_retry; 1132 } 1133 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", 1134 clnt->cl_protname, task->tk_status); 1135 task->tk_action = call_timeout; 1136 goto out_retry; 1137 } 1138 1139 /* 1140 * Ensure that we see all writes made by xprt_complete_rqst() 1141 * before it changed req->rq_received. 1142 */ 1143 smp_rmb(); 1144 req->rq_rcv_buf.len = req->rq_private_buf.len; 1145 1146 /* Check that the softirq receive buffer is valid */ 1147 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 1148 sizeof(req->rq_rcv_buf)) != 0); 1149 1150 /* Verify the RPC header */ 1151 p = call_verify(task); 1152 if (IS_ERR(p)) { 1153 if (p == ERR_PTR(-EAGAIN)) 1154 goto out_retry; 1155 return; 1156 } 1157 1158 task->tk_action = rpc_exit_task; 1159 1160 if (decode) { 1161 lock_kernel(); 1162 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 1163 task->tk_msg.rpc_resp); 1164 unlock_kernel(); 1165 } 1166 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid, 1167 task->tk_status); 1168 return; 1169 out_retry: 1170 req->rq_received = req->rq_private_buf.len = 0; 1171 task->tk_status = 0; 1172 } 1173 1174 /* 1175 * 8. Refresh the credentials if rejected by the server 1176 */ 1177 static void 1178 call_refresh(struct rpc_task *task) 1179 { 1180 dprint_status(task); 1181 1182 xprt_release(task); /* Must do to obtain new XID */ 1183 task->tk_action = call_refreshresult; 1184 task->tk_status = 0; 1185 task->tk_client->cl_stats->rpcauthrefresh++; 1186 rpcauth_refreshcred(task); 1187 } 1188 1189 /* 1190 * 8a. Process the results of a credential refresh 1191 */ 1192 static void 1193 call_refreshresult(struct rpc_task *task) 1194 { 1195 int status = task->tk_status; 1196 1197 dprint_status(task); 1198 1199 task->tk_status = 0; 1200 task->tk_action = call_reserve; 1201 if (status >= 0 && rpcauth_uptodatecred(task)) 1202 return; 1203 if (status == -EACCES) { 1204 rpc_exit(task, -EACCES); 1205 return; 1206 } 1207 task->tk_action = call_refresh; 1208 if (status != -ETIMEDOUT) 1209 rpc_delay(task, 3*HZ); 1210 return; 1211 } 1212 1213 /* 1214 * Call header serialization 1215 */ 1216 static __be32 * 1217 call_header(struct rpc_task *task) 1218 { 1219 struct rpc_clnt *clnt = task->tk_client; 1220 struct rpc_rqst *req = task->tk_rqstp; 1221 __be32 *p = req->rq_svec[0].iov_base; 1222 1223 /* FIXME: check buffer size? */ 1224 1225 p = xprt_skip_transport_header(task->tk_xprt, p); 1226 *p++ = req->rq_xid; /* XID */ 1227 *p++ = htonl(RPC_CALL); /* CALL */ 1228 *p++ = htonl(RPC_VERSION); /* RPC version */ 1229 *p++ = htonl(clnt->cl_prog); /* program number */ 1230 *p++ = htonl(clnt->cl_vers); /* program version */ 1231 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 1232 p = rpcauth_marshcred(task, p); 1233 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 1234 return p; 1235 } 1236 1237 /* 1238 * Reply header verification 1239 */ 1240 static __be32 * 1241 call_verify(struct rpc_task *task) 1242 { 1243 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 1244 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 1245 __be32 *p = iov->iov_base; 1246 u32 n; 1247 int error = -EACCES; 1248 1249 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 1250 /* RFC-1014 says that the representation of XDR data must be a 1251 * multiple of four bytes 1252 * - if it isn't pointer subtraction in the NFS client may give 1253 * undefined results 1254 */ 1255 printk(KERN_WARNING 1256 "call_verify: XDR representation not a multiple of" 1257 " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len); 1258 goto out_eio; 1259 } 1260 if ((len -= 3) < 0) 1261 goto out_overflow; 1262 p += 1; /* skip XID */ 1263 1264 if ((n = ntohl(*p++)) != RPC_REPLY) { 1265 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n); 1266 goto out_garbage; 1267 } 1268 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 1269 if (--len < 0) 1270 goto out_overflow; 1271 switch ((n = ntohl(*p++))) { 1272 case RPC_AUTH_ERROR: 1273 break; 1274 case RPC_MISMATCH: 1275 dprintk("RPC: %5u %s: RPC call version " 1276 "mismatch!\n", 1277 task->tk_pid, __FUNCTION__); 1278 error = -EPROTONOSUPPORT; 1279 goto out_err; 1280 default: 1281 dprintk("RPC: %5u %s: RPC call rejected, " 1282 "unknown error: %x\n", 1283 task->tk_pid, __FUNCTION__, n); 1284 goto out_eio; 1285 } 1286 if (--len < 0) 1287 goto out_overflow; 1288 switch ((n = ntohl(*p++))) { 1289 case RPC_AUTH_REJECTEDCRED: 1290 case RPC_AUTH_REJECTEDVERF: 1291 case RPCSEC_GSS_CREDPROBLEM: 1292 case RPCSEC_GSS_CTXPROBLEM: 1293 if (!task->tk_cred_retry) 1294 break; 1295 task->tk_cred_retry--; 1296 dprintk("RPC: %5u %s: retry stale creds\n", 1297 task->tk_pid, __FUNCTION__); 1298 rpcauth_invalcred(task); 1299 task->tk_action = call_refresh; 1300 goto out_retry; 1301 case RPC_AUTH_BADCRED: 1302 case RPC_AUTH_BADVERF: 1303 /* possibly garbled cred/verf? */ 1304 if (!task->tk_garb_retry) 1305 break; 1306 task->tk_garb_retry--; 1307 dprintk("RPC: %5u %s: retry garbled creds\n", 1308 task->tk_pid, __FUNCTION__); 1309 task->tk_action = call_bind; 1310 goto out_retry; 1311 case RPC_AUTH_TOOWEAK: 1312 printk(KERN_NOTICE "call_verify: server %s requires stronger " 1313 "authentication.\n", task->tk_client->cl_server); 1314 break; 1315 default: 1316 printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n); 1317 error = -EIO; 1318 } 1319 dprintk("RPC: %5u %s: call rejected %d\n", 1320 task->tk_pid, __FUNCTION__, n); 1321 goto out_err; 1322 } 1323 if (!(p = rpcauth_checkverf(task, p))) { 1324 printk(KERN_WARNING "call_verify: auth check failed\n"); 1325 goto out_garbage; /* bad verifier, retry */ 1326 } 1327 len = p - (__be32 *)iov->iov_base - 1; 1328 if (len < 0) 1329 goto out_overflow; 1330 switch ((n = ntohl(*p++))) { 1331 case RPC_SUCCESS: 1332 return p; 1333 case RPC_PROG_UNAVAIL: 1334 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n", 1335 task->tk_pid, __FUNCTION__, 1336 (unsigned int)task->tk_client->cl_prog, 1337 task->tk_client->cl_server); 1338 error = -EPFNOSUPPORT; 1339 goto out_err; 1340 case RPC_PROG_MISMATCH: 1341 dprintk("RPC: %5u %s: program %u, version %u unsupported by " 1342 "server %s\n", task->tk_pid, __FUNCTION__, 1343 (unsigned int)task->tk_client->cl_prog, 1344 (unsigned int)task->tk_client->cl_vers, 1345 task->tk_client->cl_server); 1346 error = -EPROTONOSUPPORT; 1347 goto out_err; 1348 case RPC_PROC_UNAVAIL: 1349 dprintk("RPC: %5u %s: proc %p unsupported by program %u, " 1350 "version %u on server %s\n", 1351 task->tk_pid, __FUNCTION__, 1352 task->tk_msg.rpc_proc, 1353 task->tk_client->cl_prog, 1354 task->tk_client->cl_vers, 1355 task->tk_client->cl_server); 1356 error = -EOPNOTSUPP; 1357 goto out_err; 1358 case RPC_GARBAGE_ARGS: 1359 dprintk("RPC: %5u %s: server saw garbage\n", 1360 task->tk_pid, __FUNCTION__); 1361 break; /* retry */ 1362 default: 1363 printk(KERN_WARNING "call_verify: server accept status: %x\n", n); 1364 /* Also retry */ 1365 } 1366 1367 out_garbage: 1368 task->tk_client->cl_stats->rpcgarbage++; 1369 if (task->tk_garb_retry) { 1370 task->tk_garb_retry--; 1371 dprintk("RPC: %5u %s: retrying\n", 1372 task->tk_pid, __FUNCTION__); 1373 task->tk_action = call_bind; 1374 out_retry: 1375 return ERR_PTR(-EAGAIN); 1376 } 1377 printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__); 1378 out_eio: 1379 error = -EIO; 1380 out_err: 1381 rpc_exit(task, error); 1382 return ERR_PTR(error); 1383 out_overflow: 1384 printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__); 1385 goto out_garbage; 1386 } 1387 1388 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj) 1389 { 1390 return 0; 1391 } 1392 1393 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj) 1394 { 1395 return 0; 1396 } 1397 1398 static struct rpc_procinfo rpcproc_null = { 1399 .p_encode = rpcproc_encode_null, 1400 .p_decode = rpcproc_decode_null, 1401 }; 1402 1403 int rpc_ping(struct rpc_clnt *clnt, int flags) 1404 { 1405 struct rpc_message msg = { 1406 .rpc_proc = &rpcproc_null, 1407 }; 1408 int err; 1409 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 1410 err = rpc_call_sync(clnt, &msg, flags); 1411 put_rpccred(msg.rpc_cred); 1412 return err; 1413 } 1414