clnt.c revision e8914c65f7f8d4e8701b8e78a12b714872ea0402
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#ifdef RPC_DEBUG 40# define RPCDBG_FACILITY RPCDBG_CALL 41#endif 42 43#define dprint_status(t) \ 44 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \ 45 __FUNCTION__, t->tk_status) 46 47/* 48 * All RPC clients are linked into this list 49 */ 50static LIST_HEAD(all_clients); 51static DEFINE_SPINLOCK(rpc_client_lock); 52 53static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); 54 55 56static void call_start(struct rpc_task *task); 57static void call_reserve(struct rpc_task *task); 58static void call_reserveresult(struct rpc_task *task); 59static void call_allocate(struct rpc_task *task); 60static void call_encode(struct rpc_task *task); 61static void call_decode(struct rpc_task *task); 62static void call_bind(struct rpc_task *task); 63static void call_bind_status(struct rpc_task *task); 64static void call_transmit(struct rpc_task *task); 65static void call_status(struct rpc_task *task); 66static void call_transmit_status(struct rpc_task *task); 67static void call_refresh(struct rpc_task *task); 68static void call_refreshresult(struct rpc_task *task); 69static void call_timeout(struct rpc_task *task); 70static void call_connect(struct rpc_task *task); 71static void call_connect_status(struct rpc_task *task); 72static __be32 * call_header(struct rpc_task *task); 73static __be32 * call_verify(struct rpc_task *task); 74 75static int rpc_ping(struct rpc_clnt *clnt, int flags); 76 77static void rpc_register_client(struct rpc_clnt *clnt) 78{ 79 spin_lock(&rpc_client_lock); 80 list_add(&clnt->cl_clients, &all_clients); 81 spin_unlock(&rpc_client_lock); 82} 83 84static void rpc_unregister_client(struct rpc_clnt *clnt) 85{ 86 spin_lock(&rpc_client_lock); 87 list_del(&clnt->cl_clients); 88 spin_unlock(&rpc_client_lock); 89} 90 91static int 92rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name) 93{ 94 static uint32_t clntid; 95 int error; 96 97 clnt->cl_vfsmnt = ERR_PTR(-ENOENT); 98 clnt->cl_dentry = ERR_PTR(-ENOENT); 99 if (dir_name == NULL) 100 return 0; 101 102 clnt->cl_vfsmnt = rpc_get_mount(); 103 if (IS_ERR(clnt->cl_vfsmnt)) 104 return PTR_ERR(clnt->cl_vfsmnt); 105 106 for (;;) { 107 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname), 108 "%s/clnt%x", dir_name, 109 (unsigned int)clntid++); 110 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0'; 111 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt); 112 if (!IS_ERR(clnt->cl_dentry)) 113 return 0; 114 error = PTR_ERR(clnt->cl_dentry); 115 if (error != -EEXIST) { 116 printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n", 117 clnt->cl_pathname, error); 118 rpc_put_mount(); 119 return error; 120 } 121 } 122} 123 124static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor) 125{ 126 struct rpc_version *version; 127 struct rpc_clnt *clnt = NULL; 128 struct rpc_auth *auth; 129 int err; 130 size_t len; 131 132 /* sanity check the name before trying to print it */ 133 err = -EINVAL; 134 len = strlen(servname); 135 if (len > RPC_MAXNETNAMELEN) 136 goto out_no_rpciod; 137 len++; 138 139 dprintk("RPC: creating %s client for %s (xprt %p)\n", 140 program->name, servname, xprt); 141 142 err = rpciod_up(); 143 if (err) 144 goto out_no_rpciod; 145 err = -EINVAL; 146 if (!xprt) 147 goto out_no_xprt; 148 if (vers >= program->nrvers || !(version = program->version[vers])) 149 goto out_err; 150 151 err = -ENOMEM; 152 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 153 if (!clnt) 154 goto out_err; 155 clnt->cl_parent = clnt; 156 157 clnt->cl_server = clnt->cl_inline_name; 158 if (len > sizeof(clnt->cl_inline_name)) { 159 char *buf = kmalloc(len, GFP_KERNEL); 160 if (buf != 0) 161 clnt->cl_server = buf; 162 else 163 len = sizeof(clnt->cl_inline_name); 164 } 165 strlcpy(clnt->cl_server, servname, len); 166 167 clnt->cl_xprt = xprt; 168 clnt->cl_procinfo = version->procs; 169 clnt->cl_maxproc = version->nrprocs; 170 clnt->cl_protname = program->name; 171 clnt->cl_prog = program->number; 172 clnt->cl_vers = version->number; 173 clnt->cl_stats = program->stats; 174 clnt->cl_metrics = rpc_alloc_iostats(clnt); 175 err = -ENOMEM; 176 if (clnt->cl_metrics == NULL) 177 goto out_no_stats; 178 clnt->cl_program = program; 179 INIT_LIST_HEAD(&clnt->cl_tasks); 180 spin_lock_init(&clnt->cl_lock); 181 182 if (!xprt_bound(clnt->cl_xprt)) 183 clnt->cl_autobind = 1; 184 185 clnt->cl_rtt = &clnt->cl_rtt_default; 186 rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval); 187 188 kref_init(&clnt->cl_kref); 189 190 err = rpc_setup_pipedir(clnt, program->pipe_dir_name); 191 if (err < 0) 192 goto out_no_path; 193 194 auth = rpcauth_create(flavor, clnt); 195 if (IS_ERR(auth)) { 196 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n", 197 flavor); 198 err = PTR_ERR(auth); 199 goto out_no_auth; 200 } 201 202 /* save the nodename */ 203 clnt->cl_nodelen = strlen(utsname()->nodename); 204 if (clnt->cl_nodelen > UNX_MAXNODENAME) 205 clnt->cl_nodelen = UNX_MAXNODENAME; 206 memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen); 207 rpc_register_client(clnt); 208 return clnt; 209 210out_no_auth: 211 if (!IS_ERR(clnt->cl_dentry)) { 212 rpc_rmdir(clnt->cl_dentry); 213 rpc_put_mount(); 214 } 215out_no_path: 216 rpc_free_iostats(clnt->cl_metrics); 217out_no_stats: 218 if (clnt->cl_server != clnt->cl_inline_name) 219 kfree(clnt->cl_server); 220 kfree(clnt); 221out_err: 222 xprt_put(xprt); 223out_no_xprt: 224 rpciod_down(); 225out_no_rpciod: 226 return ERR_PTR(err); 227} 228 229/* 230 * rpc_create - create an RPC client and transport with one call 231 * @args: rpc_clnt create argument structure 232 * 233 * Creates and initializes an RPC transport and an RPC client. 234 * 235 * It can ping the server in order to determine if it is up, and to see if 236 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables 237 * this behavior so asynchronous tasks can also use rpc_create. 238 */ 239struct rpc_clnt *rpc_create(struct rpc_create_args *args) 240{ 241 struct rpc_xprt *xprt; 242 struct rpc_clnt *clnt; 243 struct xprt_create xprtargs = { 244 .ident = args->protocol, 245 .srcaddr = args->saddress, 246 .dstaddr = args->address, 247 .addrlen = args->addrsize, 248 .timeout = args->timeout 249 }; 250 char servername[20]; 251 252 xprt = xprt_create_transport(&xprtargs); 253 if (IS_ERR(xprt)) 254 return (struct rpc_clnt *)xprt; 255 256 /* 257 * If the caller chooses not to specify a hostname, whip 258 * up a string representation of the passed-in address. 259 */ 260 if (args->servername == NULL) { 261 struct sockaddr_in *addr = 262 (struct sockaddr_in *) args->address; 263 snprintf(servername, sizeof(servername), NIPQUAD_FMT, 264 NIPQUAD(addr->sin_addr.s_addr)); 265 args->servername = servername; 266 } 267 268 /* 269 * By default, kernel RPC client connects from a reserved port. 270 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters, 271 * but it is always enabled for rpciod, which handles the connect 272 * operation. 273 */ 274 xprt->resvport = 1; 275 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) 276 xprt->resvport = 0; 277 278 clnt = rpc_new_client(xprt, args->servername, args->program, 279 args->version, args->authflavor); 280 if (IS_ERR(clnt)) 281 return clnt; 282 283 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) { 284 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 285 if (err != 0) { 286 rpc_shutdown_client(clnt); 287 return ERR_PTR(err); 288 } 289 } 290 291 clnt->cl_softrtry = 1; 292 if (args->flags & RPC_CLNT_CREATE_HARDRTRY) 293 clnt->cl_softrtry = 0; 294 295 if (args->flags & RPC_CLNT_CREATE_INTR) 296 clnt->cl_intr = 1; 297 if (args->flags & RPC_CLNT_CREATE_AUTOBIND) 298 clnt->cl_autobind = 1; 299 if (args->flags & RPC_CLNT_CREATE_DISCRTRY) 300 clnt->cl_discrtry = 1; 301 302 return clnt; 303} 304EXPORT_SYMBOL_GPL(rpc_create); 305 306/* 307 * This function clones the RPC client structure. It allows us to share the 308 * same transport while varying parameters such as the authentication 309 * flavour. 310 */ 311struct rpc_clnt * 312rpc_clone_client(struct rpc_clnt *clnt) 313{ 314 struct rpc_clnt *new; 315 int err = -ENOMEM; 316 317 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL); 318 if (!new) 319 goto out_no_clnt; 320 new->cl_parent = clnt; 321 /* Turn off autobind on clones */ 322 new->cl_autobind = 0; 323 INIT_LIST_HEAD(&new->cl_tasks); 324 spin_lock_init(&new->cl_lock); 325 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval); 326 new->cl_metrics = rpc_alloc_iostats(clnt); 327 if (new->cl_metrics == NULL) 328 goto out_no_stats; 329 kref_init(&new->cl_kref); 330 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name); 331 if (err != 0) 332 goto out_no_path; 333 if (new->cl_auth) 334 atomic_inc(&new->cl_auth->au_count); 335 xprt_get(clnt->cl_xprt); 336 kref_get(&clnt->cl_kref); 337 rpc_register_client(new); 338 rpciod_up(); 339 return new; 340out_no_path: 341 rpc_free_iostats(new->cl_metrics); 342out_no_stats: 343 kfree(new); 344out_no_clnt: 345 dprintk("RPC: %s: returned error %d\n", __FUNCTION__, err); 346 return ERR_PTR(err); 347} 348EXPORT_SYMBOL_GPL(rpc_clone_client); 349 350/* 351 * Properly shut down an RPC client, terminating all outstanding 352 * requests. 353 */ 354void rpc_shutdown_client(struct rpc_clnt *clnt) 355{ 356 dprintk("RPC: shutting down %s client for %s\n", 357 clnt->cl_protname, clnt->cl_server); 358 359 while (!list_empty(&clnt->cl_tasks)) { 360 rpc_killall_tasks(clnt); 361 wait_event_timeout(destroy_wait, 362 list_empty(&clnt->cl_tasks), 1*HZ); 363 } 364 365 rpc_release_client(clnt); 366} 367EXPORT_SYMBOL_GPL(rpc_shutdown_client); 368 369/* 370 * Free an RPC client 371 */ 372static void 373rpc_free_client(struct kref *kref) 374{ 375 struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref); 376 377 dprintk("RPC: destroying %s client for %s\n", 378 clnt->cl_protname, clnt->cl_server); 379 if (!IS_ERR(clnt->cl_dentry)) { 380 rpc_rmdir(clnt->cl_dentry); 381 rpc_put_mount(); 382 } 383 if (clnt->cl_parent != clnt) { 384 rpc_release_client(clnt->cl_parent); 385 goto out_free; 386 } 387 if (clnt->cl_server != clnt->cl_inline_name) 388 kfree(clnt->cl_server); 389out_free: 390 rpc_unregister_client(clnt); 391 rpc_free_iostats(clnt->cl_metrics); 392 clnt->cl_metrics = NULL; 393 xprt_put(clnt->cl_xprt); 394 rpciod_down(); 395 kfree(clnt); 396} 397 398/* 399 * Free an RPC client 400 */ 401static void 402rpc_free_auth(struct kref *kref) 403{ 404 struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref); 405 406 if (clnt->cl_auth == NULL) { 407 rpc_free_client(kref); 408 return; 409 } 410 411 /* 412 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to 413 * release remaining GSS contexts. This mechanism ensures 414 * that it can do so safely. 415 */ 416 kref_init(kref); 417 rpcauth_release(clnt->cl_auth); 418 clnt->cl_auth = NULL; 419 kref_put(kref, rpc_free_client); 420} 421 422/* 423 * Release reference to the RPC client 424 */ 425void 426rpc_release_client(struct rpc_clnt *clnt) 427{ 428 dprintk("RPC: rpc_release_client(%p)\n", clnt); 429 430 if (list_empty(&clnt->cl_tasks)) 431 wake_up(&destroy_wait); 432 kref_put(&clnt->cl_kref, rpc_free_auth); 433} 434 435/** 436 * rpc_bind_new_program - bind a new RPC program to an existing client 437 * @old - old rpc_client 438 * @program - rpc program to set 439 * @vers - rpc program version 440 * 441 * Clones the rpc client and sets up a new RPC program. This is mainly 442 * of use for enabling different RPC programs to share the same transport. 443 * The Sun NFSv2/v3 ACL protocol can do this. 444 */ 445struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old, 446 struct rpc_program *program, 447 u32 vers) 448{ 449 struct rpc_clnt *clnt; 450 struct rpc_version *version; 451 int err; 452 453 BUG_ON(vers >= program->nrvers || !program->version[vers]); 454 version = program->version[vers]; 455 clnt = rpc_clone_client(old); 456 if (IS_ERR(clnt)) 457 goto out; 458 clnt->cl_procinfo = version->procs; 459 clnt->cl_maxproc = version->nrprocs; 460 clnt->cl_protname = program->name; 461 clnt->cl_prog = program->number; 462 clnt->cl_vers = version->number; 463 clnt->cl_stats = program->stats; 464 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 465 if (err != 0) { 466 rpc_shutdown_client(clnt); 467 clnt = ERR_PTR(err); 468 } 469out: 470 return clnt; 471} 472EXPORT_SYMBOL_GPL(rpc_bind_new_program); 473 474/* 475 * Default callback for async RPC calls 476 */ 477static void 478rpc_default_callback(struct rpc_task *task, void *data) 479{ 480} 481 482static const struct rpc_call_ops rpc_default_ops = { 483 .rpc_call_done = rpc_default_callback, 484}; 485 486/* 487 * Export the signal mask handling for synchronous code that 488 * sleeps on RPC calls 489 */ 490#define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM)) 491 492static void rpc_save_sigmask(sigset_t *oldset, int intr) 493{ 494 unsigned long sigallow = sigmask(SIGKILL); 495 sigset_t sigmask; 496 497 /* Block all signals except those listed in sigallow */ 498 if (intr) 499 sigallow |= RPC_INTR_SIGNALS; 500 siginitsetinv(&sigmask, sigallow); 501 sigprocmask(SIG_BLOCK, &sigmask, oldset); 502} 503 504static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset) 505{ 506 rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task)); 507} 508 509static inline void rpc_restore_sigmask(sigset_t *oldset) 510{ 511 sigprocmask(SIG_SETMASK, oldset, NULL); 512} 513 514void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset) 515{ 516 rpc_save_sigmask(oldset, clnt->cl_intr); 517} 518EXPORT_SYMBOL_GPL(rpc_clnt_sigmask); 519 520void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset) 521{ 522 rpc_restore_sigmask(oldset); 523} 524EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask); 525 526static 527struct rpc_task *rpc_do_run_task(struct rpc_clnt *clnt, 528 struct rpc_message *msg, 529 int flags, 530 const struct rpc_call_ops *ops, 531 void *data) 532{ 533 struct rpc_task *task, *ret; 534 sigset_t oldset; 535 536 task = rpc_new_task(clnt, flags, ops, data); 537 if (task == NULL) { 538 rpc_release_calldata(ops, data); 539 return ERR_PTR(-ENOMEM); 540 } 541 542 /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */ 543 rpc_task_sigmask(task, &oldset); 544 if (msg != NULL) { 545 rpc_call_setup(task, msg, 0); 546 if (task->tk_status != 0) { 547 ret = ERR_PTR(task->tk_status); 548 rpc_put_task(task); 549 goto out; 550 } 551 } 552 atomic_inc(&task->tk_count); 553 rpc_execute(task); 554 ret = task; 555out: 556 rpc_restore_sigmask(&oldset); 557 return ret; 558} 559 560/** 561 * rpc_call_sync - Perform a synchronous RPC call 562 * @clnt: pointer to RPC client 563 * @msg: RPC call parameters 564 * @flags: RPC call flags 565 */ 566int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags) 567{ 568 struct rpc_task *task; 569 int status; 570 571 BUG_ON(flags & RPC_TASK_ASYNC); 572 573 task = rpc_do_run_task(clnt, msg, flags, &rpc_default_ops, NULL); 574 if (IS_ERR(task)) 575 return PTR_ERR(task); 576 status = task->tk_status; 577 rpc_put_task(task); 578 return status; 579} 580EXPORT_SYMBOL_GPL(rpc_call_sync); 581 582/** 583 * rpc_call_async - Perform an asynchronous RPC call 584 * @clnt: pointer to RPC client 585 * @msg: RPC call parameters 586 * @flags: RPC call flags 587 * @ops: RPC call ops 588 * @data: user call data 589 */ 590int 591rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags, 592 const struct rpc_call_ops *tk_ops, void *data) 593{ 594 struct rpc_task *task; 595 596 task = rpc_do_run_task(clnt, msg, flags|RPC_TASK_ASYNC, tk_ops, data); 597 if (IS_ERR(task)) 598 return PTR_ERR(task); 599 rpc_put_task(task); 600 return 0; 601} 602EXPORT_SYMBOL_GPL(rpc_call_async); 603 604/** 605 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it 606 * @clnt: pointer to RPC client 607 * @flags: RPC flags 608 * @ops: RPC call ops 609 * @data: user call data 610 */ 611struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags, 612 const struct rpc_call_ops *tk_ops, 613 void *data) 614{ 615 return rpc_do_run_task(clnt, NULL, flags, tk_ops, data); 616} 617EXPORT_SYMBOL_GPL(rpc_run_task); 618 619void 620rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags) 621{ 622 task->tk_msg = *msg; 623 task->tk_flags |= flags; 624 /* Bind the user cred */ 625 if (task->tk_msg.rpc_cred != NULL) 626 rpcauth_holdcred(task); 627 else 628 rpcauth_bindcred(task); 629 630 if (task->tk_status == 0) 631 task->tk_action = call_start; 632 else 633 task->tk_action = rpc_exit_task; 634} 635EXPORT_SYMBOL_GPL(rpc_call_setup); 636 637/** 638 * rpc_peeraddr - extract remote peer address from clnt's xprt 639 * @clnt: RPC client structure 640 * @buf: target buffer 641 * @size: length of target buffer 642 * 643 * Returns the number of bytes that are actually in the stored address. 644 */ 645size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize) 646{ 647 size_t bytes; 648 struct rpc_xprt *xprt = clnt->cl_xprt; 649 650 bytes = sizeof(xprt->addr); 651 if (bytes > bufsize) 652 bytes = bufsize; 653 memcpy(buf, &clnt->cl_xprt->addr, bytes); 654 return xprt->addrlen; 655} 656EXPORT_SYMBOL_GPL(rpc_peeraddr); 657 658/** 659 * rpc_peeraddr2str - return remote peer address in printable format 660 * @clnt: RPC client structure 661 * @format: address format 662 * 663 */ 664char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format) 665{ 666 struct rpc_xprt *xprt = clnt->cl_xprt; 667 668 if (xprt->address_strings[format] != NULL) 669 return xprt->address_strings[format]; 670 else 671 return "unprintable"; 672} 673EXPORT_SYMBOL_GPL(rpc_peeraddr2str); 674 675void 676rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 677{ 678 struct rpc_xprt *xprt = clnt->cl_xprt; 679 if (xprt->ops->set_buffer_size) 680 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 681} 682EXPORT_SYMBOL_GPL(rpc_setbufsize); 683 684/* 685 * Return size of largest payload RPC client can support, in bytes 686 * 687 * For stream transports, this is one RPC record fragment (see RFC 688 * 1831), as we don't support multi-record requests yet. For datagram 689 * transports, this is the size of an IP packet minus the IP, UDP, and 690 * RPC header sizes. 691 */ 692size_t rpc_max_payload(struct rpc_clnt *clnt) 693{ 694 return clnt->cl_xprt->max_payload; 695} 696EXPORT_SYMBOL_GPL(rpc_max_payload); 697 698/** 699 * rpc_force_rebind - force transport to check that remote port is unchanged 700 * @clnt: client to rebind 701 * 702 */ 703void rpc_force_rebind(struct rpc_clnt *clnt) 704{ 705 if (clnt->cl_autobind) 706 xprt_clear_bound(clnt->cl_xprt); 707} 708EXPORT_SYMBOL_GPL(rpc_force_rebind); 709 710/* 711 * Restart an (async) RPC call. Usually called from within the 712 * exit handler. 713 */ 714void 715rpc_restart_call(struct rpc_task *task) 716{ 717 if (RPC_ASSASSINATED(task)) 718 return; 719 720 task->tk_action = call_start; 721} 722EXPORT_SYMBOL_GPL(rpc_restart_call); 723 724/* 725 * 0. Initial state 726 * 727 * Other FSM states can be visited zero or more times, but 728 * this state is visited exactly once for each RPC. 729 */ 730static void 731call_start(struct rpc_task *task) 732{ 733 struct rpc_clnt *clnt = task->tk_client; 734 735 dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid, 736 clnt->cl_protname, clnt->cl_vers, 737 task->tk_msg.rpc_proc->p_proc, 738 (RPC_IS_ASYNC(task) ? "async" : "sync")); 739 740 /* Increment call count */ 741 task->tk_msg.rpc_proc->p_count++; 742 clnt->cl_stats->rpccnt++; 743 task->tk_action = call_reserve; 744} 745 746/* 747 * 1. Reserve an RPC call slot 748 */ 749static void 750call_reserve(struct rpc_task *task) 751{ 752 dprint_status(task); 753 754 if (!rpcauth_uptodatecred(task)) { 755 task->tk_action = call_refresh; 756 return; 757 } 758 759 task->tk_status = 0; 760 task->tk_action = call_reserveresult; 761 xprt_reserve(task); 762} 763 764/* 765 * 1b. Grok the result of xprt_reserve() 766 */ 767static void 768call_reserveresult(struct rpc_task *task) 769{ 770 int status = task->tk_status; 771 772 dprint_status(task); 773 774 /* 775 * After a call to xprt_reserve(), we must have either 776 * a request slot or else an error status. 777 */ 778 task->tk_status = 0; 779 if (status >= 0) { 780 if (task->tk_rqstp) { 781 task->tk_action = call_allocate; 782 return; 783 } 784 785 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 786 __FUNCTION__, status); 787 rpc_exit(task, -EIO); 788 return; 789 } 790 791 /* 792 * Even though there was an error, we may have acquired 793 * a request slot somehow. Make sure not to leak it. 794 */ 795 if (task->tk_rqstp) { 796 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 797 __FUNCTION__, status); 798 xprt_release(task); 799 } 800 801 switch (status) { 802 case -EAGAIN: /* woken up; retry */ 803 task->tk_action = call_reserve; 804 return; 805 case -EIO: /* probably a shutdown */ 806 break; 807 default: 808 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 809 __FUNCTION__, status); 810 break; 811 } 812 rpc_exit(task, status); 813} 814 815/* 816 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. 817 * (Note: buffer memory is freed in xprt_release). 818 */ 819static void 820call_allocate(struct rpc_task *task) 821{ 822 unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack; 823 struct rpc_rqst *req = task->tk_rqstp; 824 struct rpc_xprt *xprt = task->tk_xprt; 825 struct rpc_procinfo *proc = task->tk_msg.rpc_proc; 826 827 dprint_status(task); 828 829 task->tk_status = 0; 830 task->tk_action = call_bind; 831 832 if (req->rq_buffer) 833 return; 834 835 if (proc->p_proc != 0) { 836 BUG_ON(proc->p_arglen == 0); 837 if (proc->p_decode != NULL) 838 BUG_ON(proc->p_replen == 0); 839 } 840 841 /* 842 * Calculate the size (in quads) of the RPC call 843 * and reply headers, and convert both values 844 * to byte sizes. 845 */ 846 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen; 847 req->rq_callsize <<= 2; 848 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen; 849 req->rq_rcvsize <<= 2; 850 851 req->rq_buffer = xprt->ops->buf_alloc(task, 852 req->rq_callsize + req->rq_rcvsize); 853 if (req->rq_buffer != NULL) 854 return; 855 856 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid); 857 858 if (RPC_IS_ASYNC(task) || !signalled()) { 859 task->tk_action = call_allocate; 860 rpc_delay(task, HZ>>4); 861 return; 862 } 863 864 rpc_exit(task, -ERESTARTSYS); 865} 866 867static inline int 868rpc_task_need_encode(struct rpc_task *task) 869{ 870 return task->tk_rqstp->rq_snd_buf.len == 0; 871} 872 873static inline void 874rpc_task_force_reencode(struct rpc_task *task) 875{ 876 task->tk_rqstp->rq_snd_buf.len = 0; 877} 878 879static inline void 880rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len) 881{ 882 buf->head[0].iov_base = start; 883 buf->head[0].iov_len = len; 884 buf->tail[0].iov_len = 0; 885 buf->page_len = 0; 886 buf->flags = 0; 887 buf->len = 0; 888 buf->buflen = len; 889} 890 891/* 892 * 3. Encode arguments of an RPC call 893 */ 894static void 895call_encode(struct rpc_task *task) 896{ 897 struct rpc_rqst *req = task->tk_rqstp; 898 kxdrproc_t encode; 899 __be32 *p; 900 901 dprint_status(task); 902 903 rpc_xdr_buf_init(&req->rq_snd_buf, 904 req->rq_buffer, 905 req->rq_callsize); 906 rpc_xdr_buf_init(&req->rq_rcv_buf, 907 (char *)req->rq_buffer + req->rq_callsize, 908 req->rq_rcvsize); 909 910 /* Encode header and provided arguments */ 911 encode = task->tk_msg.rpc_proc->p_encode; 912 if (!(p = call_header(task))) { 913 printk(KERN_INFO "RPC: call_header failed, exit EIO\n"); 914 rpc_exit(task, -EIO); 915 return; 916 } 917 if (encode == NULL) 918 return; 919 920 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 921 task->tk_msg.rpc_argp); 922 if (task->tk_status == -ENOMEM) { 923 /* XXX: Is this sane? */ 924 rpc_delay(task, 3*HZ); 925 task->tk_status = -EAGAIN; 926 } 927} 928 929/* 930 * 4. Get the server port number if not yet set 931 */ 932static void 933call_bind(struct rpc_task *task) 934{ 935 struct rpc_xprt *xprt = task->tk_xprt; 936 937 dprint_status(task); 938 939 task->tk_action = call_connect; 940 if (!xprt_bound(xprt)) { 941 task->tk_action = call_bind_status; 942 task->tk_timeout = xprt->bind_timeout; 943 xprt->ops->rpcbind(task); 944 } 945} 946 947/* 948 * 4a. Sort out bind result 949 */ 950static void 951call_bind_status(struct rpc_task *task) 952{ 953 int status = -EIO; 954 955 if (task->tk_status >= 0) { 956 dprint_status(task); 957 task->tk_status = 0; 958 task->tk_action = call_connect; 959 return; 960 } 961 962 switch (task->tk_status) { 963 case -EAGAIN: 964 dprintk("RPC: %5u rpcbind waiting for another request " 965 "to finish\n", task->tk_pid); 966 /* avoid busy-waiting here -- could be a network outage. */ 967 rpc_delay(task, 5*HZ); 968 goto retry_timeout; 969 case -EACCES: 970 dprintk("RPC: %5u remote rpcbind: RPC program/version " 971 "unavailable\n", task->tk_pid); 972 /* fail immediately if this is an RPC ping */ 973 if (task->tk_msg.rpc_proc->p_proc == 0) { 974 status = -EOPNOTSUPP; 975 break; 976 } 977 rpc_delay(task, 3*HZ); 978 goto retry_timeout; 979 case -ETIMEDOUT: 980 dprintk("RPC: %5u rpcbind request timed out\n", 981 task->tk_pid); 982 goto retry_timeout; 983 case -EPFNOSUPPORT: 984 /* server doesn't support any rpcbind version we know of */ 985 dprintk("RPC: %5u remote rpcbind service unavailable\n", 986 task->tk_pid); 987 break; 988 case -EPROTONOSUPPORT: 989 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n", 990 task->tk_pid); 991 task->tk_status = 0; 992 task->tk_action = call_bind; 993 return; 994 default: 995 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n", 996 task->tk_pid, -task->tk_status); 997 } 998 999 rpc_exit(task, status); 1000 return; 1001 1002retry_timeout: 1003 task->tk_action = call_timeout; 1004} 1005 1006/* 1007 * 4b. Connect to the RPC server 1008 */ 1009static void 1010call_connect(struct rpc_task *task) 1011{ 1012 struct rpc_xprt *xprt = task->tk_xprt; 1013 1014 dprintk("RPC: %5u call_connect xprt %p %s connected\n", 1015 task->tk_pid, xprt, 1016 (xprt_connected(xprt) ? "is" : "is not")); 1017 1018 task->tk_action = call_transmit; 1019 if (!xprt_connected(xprt)) { 1020 task->tk_action = call_connect_status; 1021 if (task->tk_status < 0) 1022 return; 1023 xprt_connect(task); 1024 } 1025} 1026 1027/* 1028 * 4c. Sort out connect result 1029 */ 1030static void 1031call_connect_status(struct rpc_task *task) 1032{ 1033 struct rpc_clnt *clnt = task->tk_client; 1034 int status = task->tk_status; 1035 1036 dprint_status(task); 1037 1038 task->tk_status = 0; 1039 if (status >= 0) { 1040 clnt->cl_stats->netreconn++; 1041 task->tk_action = call_transmit; 1042 return; 1043 } 1044 1045 /* Something failed: remote service port may have changed */ 1046 rpc_force_rebind(clnt); 1047 1048 switch (status) { 1049 case -ENOTCONN: 1050 case -EAGAIN: 1051 task->tk_action = call_bind; 1052 if (!RPC_IS_SOFT(task)) 1053 return; 1054 /* if soft mounted, test if we've timed out */ 1055 case -ETIMEDOUT: 1056 task->tk_action = call_timeout; 1057 return; 1058 } 1059 rpc_exit(task, -EIO); 1060} 1061 1062/* 1063 * 5. Transmit the RPC request, and wait for reply 1064 */ 1065static void 1066call_transmit(struct rpc_task *task) 1067{ 1068 dprint_status(task); 1069 1070 task->tk_action = call_status; 1071 if (task->tk_status < 0) 1072 return; 1073 task->tk_status = xprt_prepare_transmit(task); 1074 if (task->tk_status != 0) 1075 return; 1076 task->tk_action = call_transmit_status; 1077 /* Encode here so that rpcsec_gss can use correct sequence number. */ 1078 if (rpc_task_need_encode(task)) { 1079 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0); 1080 call_encode(task); 1081 /* Did the encode result in an error condition? */ 1082 if (task->tk_status != 0) 1083 return; 1084 } 1085 xprt_transmit(task); 1086 if (task->tk_status < 0) 1087 return; 1088 /* 1089 * On success, ensure that we call xprt_end_transmit() before sleeping 1090 * in order to allow access to the socket to other RPC requests. 1091 */ 1092 call_transmit_status(task); 1093 if (task->tk_msg.rpc_proc->p_decode != NULL) 1094 return; 1095 task->tk_action = rpc_exit_task; 1096 rpc_wake_up_task(task); 1097} 1098 1099/* 1100 * 5a. Handle cleanup after a transmission 1101 */ 1102static void 1103call_transmit_status(struct rpc_task *task) 1104{ 1105 task->tk_action = call_status; 1106 /* 1107 * Special case: if we've been waiting on the socket's write_space() 1108 * callback, then don't call xprt_end_transmit(). 1109 */ 1110 if (task->tk_status == -EAGAIN) 1111 return; 1112 xprt_end_transmit(task); 1113 rpc_task_force_reencode(task); 1114} 1115 1116/* 1117 * 6. Sort out the RPC call status 1118 */ 1119static void 1120call_status(struct rpc_task *task) 1121{ 1122 struct rpc_clnt *clnt = task->tk_client; 1123 struct rpc_rqst *req = task->tk_rqstp; 1124 int status; 1125 1126 if (req->rq_received > 0 && !req->rq_bytes_sent) 1127 task->tk_status = req->rq_received; 1128 1129 dprint_status(task); 1130 1131 status = task->tk_status; 1132 if (status >= 0) { 1133 task->tk_action = call_decode; 1134 return; 1135 } 1136 1137 task->tk_status = 0; 1138 switch(status) { 1139 case -EHOSTDOWN: 1140 case -EHOSTUNREACH: 1141 case -ENETUNREACH: 1142 /* 1143 * Delay any retries for 3 seconds, then handle as if it 1144 * were a timeout. 1145 */ 1146 rpc_delay(task, 3*HZ); 1147 case -ETIMEDOUT: 1148 task->tk_action = call_timeout; 1149 if (task->tk_client->cl_discrtry) 1150 xprt_force_disconnect(task->tk_xprt); 1151 break; 1152 case -ECONNREFUSED: 1153 case -ENOTCONN: 1154 rpc_force_rebind(clnt); 1155 task->tk_action = call_bind; 1156 break; 1157 case -EAGAIN: 1158 task->tk_action = call_transmit; 1159 break; 1160 case -EIO: 1161 /* shutdown or soft timeout */ 1162 rpc_exit(task, status); 1163 break; 1164 default: 1165 printk("%s: RPC call returned error %d\n", 1166 clnt->cl_protname, -status); 1167 rpc_exit(task, status); 1168 } 1169} 1170 1171/* 1172 * 6a. Handle RPC timeout 1173 * We do not release the request slot, so we keep using the 1174 * same XID for all retransmits. 1175 */ 1176static void 1177call_timeout(struct rpc_task *task) 1178{ 1179 struct rpc_clnt *clnt = task->tk_client; 1180 1181 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 1182 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid); 1183 goto retry; 1184 } 1185 1186 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid); 1187 task->tk_timeouts++; 1188 1189 if (RPC_IS_SOFT(task)) { 1190 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 1191 clnt->cl_protname, clnt->cl_server); 1192 rpc_exit(task, -EIO); 1193 return; 1194 } 1195 1196 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 1197 task->tk_flags |= RPC_CALL_MAJORSEEN; 1198 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 1199 clnt->cl_protname, clnt->cl_server); 1200 } 1201 rpc_force_rebind(clnt); 1202 1203retry: 1204 clnt->cl_stats->rpcretrans++; 1205 task->tk_action = call_bind; 1206 task->tk_status = 0; 1207} 1208 1209/* 1210 * 7. Decode the RPC reply 1211 */ 1212static void 1213call_decode(struct rpc_task *task) 1214{ 1215 struct rpc_clnt *clnt = task->tk_client; 1216 struct rpc_rqst *req = task->tk_rqstp; 1217 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode; 1218 __be32 *p; 1219 1220 dprintk("RPC: %5u call_decode (status %d)\n", 1221 task->tk_pid, task->tk_status); 1222 1223 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 1224 printk(KERN_NOTICE "%s: server %s OK\n", 1225 clnt->cl_protname, clnt->cl_server); 1226 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 1227 } 1228 1229 if (task->tk_status < 12) { 1230 if (!RPC_IS_SOFT(task)) { 1231 task->tk_action = call_bind; 1232 clnt->cl_stats->rpcretrans++; 1233 goto out_retry; 1234 } 1235 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", 1236 clnt->cl_protname, task->tk_status); 1237 task->tk_action = call_timeout; 1238 goto out_retry; 1239 } 1240 1241 /* 1242 * Ensure that we see all writes made by xprt_complete_rqst() 1243 * before it changed req->rq_received. 1244 */ 1245 smp_rmb(); 1246 req->rq_rcv_buf.len = req->rq_private_buf.len; 1247 1248 /* Check that the softirq receive buffer is valid */ 1249 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 1250 sizeof(req->rq_rcv_buf)) != 0); 1251 1252 /* Verify the RPC header */ 1253 p = call_verify(task); 1254 if (IS_ERR(p)) { 1255 if (p == ERR_PTR(-EAGAIN)) 1256 goto out_retry; 1257 return; 1258 } 1259 1260 task->tk_action = rpc_exit_task; 1261 1262 if (decode) { 1263 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 1264 task->tk_msg.rpc_resp); 1265 } 1266 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid, 1267 task->tk_status); 1268 return; 1269out_retry: 1270 req->rq_received = req->rq_private_buf.len = 0; 1271 task->tk_status = 0; 1272 if (task->tk_client->cl_discrtry) 1273 xprt_force_disconnect(task->tk_xprt); 1274} 1275 1276/* 1277 * 8. Refresh the credentials if rejected by the server 1278 */ 1279static void 1280call_refresh(struct rpc_task *task) 1281{ 1282 dprint_status(task); 1283 1284 task->tk_action = call_refreshresult; 1285 task->tk_status = 0; 1286 task->tk_client->cl_stats->rpcauthrefresh++; 1287 rpcauth_refreshcred(task); 1288} 1289 1290/* 1291 * 8a. Process the results of a credential refresh 1292 */ 1293static void 1294call_refreshresult(struct rpc_task *task) 1295{ 1296 int status = task->tk_status; 1297 1298 dprint_status(task); 1299 1300 task->tk_status = 0; 1301 task->tk_action = call_reserve; 1302 if (status >= 0 && rpcauth_uptodatecred(task)) 1303 return; 1304 if (status == -EACCES) { 1305 rpc_exit(task, -EACCES); 1306 return; 1307 } 1308 task->tk_action = call_refresh; 1309 if (status != -ETIMEDOUT) 1310 rpc_delay(task, 3*HZ); 1311 return; 1312} 1313 1314/* 1315 * Call header serialization 1316 */ 1317static __be32 * 1318call_header(struct rpc_task *task) 1319{ 1320 struct rpc_clnt *clnt = task->tk_client; 1321 struct rpc_rqst *req = task->tk_rqstp; 1322 __be32 *p = req->rq_svec[0].iov_base; 1323 1324 /* FIXME: check buffer size? */ 1325 1326 p = xprt_skip_transport_header(task->tk_xprt, p); 1327 *p++ = req->rq_xid; /* XID */ 1328 *p++ = htonl(RPC_CALL); /* CALL */ 1329 *p++ = htonl(RPC_VERSION); /* RPC version */ 1330 *p++ = htonl(clnt->cl_prog); /* program number */ 1331 *p++ = htonl(clnt->cl_vers); /* program version */ 1332 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 1333 p = rpcauth_marshcred(task, p); 1334 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 1335 return p; 1336} 1337 1338/* 1339 * Reply header verification 1340 */ 1341static __be32 * 1342call_verify(struct rpc_task *task) 1343{ 1344 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 1345 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 1346 __be32 *p = iov->iov_base; 1347 u32 n; 1348 int error = -EACCES; 1349 1350 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 1351 /* RFC-1014 says that the representation of XDR data must be a 1352 * multiple of four bytes 1353 * - if it isn't pointer subtraction in the NFS client may give 1354 * undefined results 1355 */ 1356 dprintk("RPC: %5u %s: XDR representation not a multiple of" 1357 " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__, 1358 task->tk_rqstp->rq_rcv_buf.len); 1359 goto out_eio; 1360 } 1361 if ((len -= 3) < 0) 1362 goto out_overflow; 1363 p += 1; /* skip XID */ 1364 1365 if ((n = ntohl(*p++)) != RPC_REPLY) { 1366 dprintk("RPC: %5u %s: not an RPC reply: %x\n", 1367 task->tk_pid, __FUNCTION__, n); 1368 goto out_garbage; 1369 } 1370 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 1371 if (--len < 0) 1372 goto out_overflow; 1373 switch ((n = ntohl(*p++))) { 1374 case RPC_AUTH_ERROR: 1375 break; 1376 case RPC_MISMATCH: 1377 dprintk("RPC: %5u %s: RPC call version " 1378 "mismatch!\n", 1379 task->tk_pid, __FUNCTION__); 1380 error = -EPROTONOSUPPORT; 1381 goto out_err; 1382 default: 1383 dprintk("RPC: %5u %s: RPC call rejected, " 1384 "unknown error: %x\n", 1385 task->tk_pid, __FUNCTION__, n); 1386 goto out_eio; 1387 } 1388 if (--len < 0) 1389 goto out_overflow; 1390 switch ((n = ntohl(*p++))) { 1391 case RPC_AUTH_REJECTEDCRED: 1392 case RPC_AUTH_REJECTEDVERF: 1393 case RPCSEC_GSS_CREDPROBLEM: 1394 case RPCSEC_GSS_CTXPROBLEM: 1395 if (!task->tk_cred_retry) 1396 break; 1397 task->tk_cred_retry--; 1398 dprintk("RPC: %5u %s: retry stale creds\n", 1399 task->tk_pid, __FUNCTION__); 1400 rpcauth_invalcred(task); 1401 /* Ensure we obtain a new XID! */ 1402 xprt_release(task); 1403 task->tk_action = call_refresh; 1404 goto out_retry; 1405 case RPC_AUTH_BADCRED: 1406 case RPC_AUTH_BADVERF: 1407 /* possibly garbled cred/verf? */ 1408 if (!task->tk_garb_retry) 1409 break; 1410 task->tk_garb_retry--; 1411 dprintk("RPC: %5u %s: retry garbled creds\n", 1412 task->tk_pid, __FUNCTION__); 1413 task->tk_action = call_bind; 1414 goto out_retry; 1415 case RPC_AUTH_TOOWEAK: 1416 printk(KERN_NOTICE "call_verify: server %s requires stronger " 1417 "authentication.\n", task->tk_client->cl_server); 1418 break; 1419 default: 1420 dprintk("RPC: %5u %s: unknown auth error: %x\n", 1421 task->tk_pid, __FUNCTION__, n); 1422 error = -EIO; 1423 } 1424 dprintk("RPC: %5u %s: call rejected %d\n", 1425 task->tk_pid, __FUNCTION__, n); 1426 goto out_err; 1427 } 1428 if (!(p = rpcauth_checkverf(task, p))) { 1429 dprintk("RPC: %5u %s: auth check failed\n", 1430 task->tk_pid, __FUNCTION__); 1431 goto out_garbage; /* bad verifier, retry */ 1432 } 1433 len = p - (__be32 *)iov->iov_base - 1; 1434 if (len < 0) 1435 goto out_overflow; 1436 switch ((n = ntohl(*p++))) { 1437 case RPC_SUCCESS: 1438 return p; 1439 case RPC_PROG_UNAVAIL: 1440 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n", 1441 task->tk_pid, __FUNCTION__, 1442 (unsigned int)task->tk_client->cl_prog, 1443 task->tk_client->cl_server); 1444 error = -EPFNOSUPPORT; 1445 goto out_err; 1446 case RPC_PROG_MISMATCH: 1447 dprintk("RPC: %5u %s: program %u, version %u unsupported by " 1448 "server %s\n", task->tk_pid, __FUNCTION__, 1449 (unsigned int)task->tk_client->cl_prog, 1450 (unsigned int)task->tk_client->cl_vers, 1451 task->tk_client->cl_server); 1452 error = -EPROTONOSUPPORT; 1453 goto out_err; 1454 case RPC_PROC_UNAVAIL: 1455 dprintk("RPC: %5u %s: proc %p unsupported by program %u, " 1456 "version %u on server %s\n", 1457 task->tk_pid, __FUNCTION__, 1458 task->tk_msg.rpc_proc, 1459 task->tk_client->cl_prog, 1460 task->tk_client->cl_vers, 1461 task->tk_client->cl_server); 1462 error = -EOPNOTSUPP; 1463 goto out_err; 1464 case RPC_GARBAGE_ARGS: 1465 dprintk("RPC: %5u %s: server saw garbage\n", 1466 task->tk_pid, __FUNCTION__); 1467 break; /* retry */ 1468 default: 1469 dprintk("RPC: %5u %s: server accept status: %x\n", 1470 task->tk_pid, __FUNCTION__, n); 1471 /* Also retry */ 1472 } 1473 1474out_garbage: 1475 task->tk_client->cl_stats->rpcgarbage++; 1476 if (task->tk_garb_retry) { 1477 task->tk_garb_retry--; 1478 dprintk("RPC: %5u %s: retrying\n", 1479 task->tk_pid, __FUNCTION__); 1480 task->tk_action = call_bind; 1481out_retry: 1482 return ERR_PTR(-EAGAIN); 1483 } 1484out_eio: 1485 error = -EIO; 1486out_err: 1487 rpc_exit(task, error); 1488 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid, 1489 __FUNCTION__, error); 1490 return ERR_PTR(error); 1491out_overflow: 1492 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid, 1493 __FUNCTION__); 1494 goto out_garbage; 1495} 1496 1497static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj) 1498{ 1499 return 0; 1500} 1501 1502static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj) 1503{ 1504 return 0; 1505} 1506 1507static struct rpc_procinfo rpcproc_null = { 1508 .p_encode = rpcproc_encode_null, 1509 .p_decode = rpcproc_decode_null, 1510}; 1511 1512static int rpc_ping(struct rpc_clnt *clnt, int flags) 1513{ 1514 struct rpc_message msg = { 1515 .rpc_proc = &rpcproc_null, 1516 }; 1517 int err; 1518 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 1519 err = rpc_call_sync(clnt, &msg, flags); 1520 put_rpccred(msg.rpc_cred); 1521 return err; 1522} 1523 1524struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags) 1525{ 1526 struct rpc_message msg = { 1527 .rpc_proc = &rpcproc_null, 1528 .rpc_cred = cred, 1529 }; 1530 return rpc_do_run_task(clnt, &msg, flags, &rpc_default_ops, NULL); 1531} 1532EXPORT_SYMBOL_GPL(rpc_call_null); 1533 1534#ifdef RPC_DEBUG 1535void rpc_show_tasks(void) 1536{ 1537 struct rpc_clnt *clnt; 1538 struct rpc_task *t; 1539 1540 spin_lock(&rpc_client_lock); 1541 if (list_empty(&all_clients)) 1542 goto out; 1543 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout " 1544 "-rpcwait -action- ---ops--\n"); 1545 list_for_each_entry(clnt, &all_clients, cl_clients) { 1546 if (list_empty(&clnt->cl_tasks)) 1547 continue; 1548 spin_lock(&clnt->cl_lock); 1549 list_for_each_entry(t, &clnt->cl_tasks, tk_task) { 1550 const char *rpc_waitq = "none"; 1551 int proc; 1552 1553 if (t->tk_msg.rpc_proc) 1554 proc = t->tk_msg.rpc_proc->p_proc; 1555 else 1556 proc = -1; 1557 1558 if (RPC_IS_QUEUED(t)) 1559 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq); 1560 1561 printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n", 1562 t->tk_pid, proc, 1563 t->tk_flags, t->tk_status, 1564 t->tk_client, 1565 (t->tk_client ? t->tk_client->cl_prog : 0), 1566 t->tk_rqstp, t->tk_timeout, 1567 rpc_waitq, 1568 t->tk_action, t->tk_ops); 1569 } 1570 spin_unlock(&clnt->cl_lock); 1571 } 1572out: 1573 spin_unlock(&rpc_client_lock); 1574} 1575#endif 1576