net/sunrpc/clnt.c

   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 #include <linux/in6.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38
  39
  40 #ifdef RPC_DEBUG
  41 # define RPCDBG_FACILITY        RPCDBG_CALL
  42 #endif
  43
  44 #define dprint_status(t)                                        \
  45         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  46                         __FUNCTION__, t->tk_status)
  47
  48 /*
  49  * All RPC clients are linked into this list
  50  */
  51 static LIST_HEAD(all_clients);
  52 static DEFINE_SPINLOCK(rpc_client_lock);
  53
  54 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  55
  56
  57 static void     call_start(struct rpc_task *task);
  58 static void     call_reserve(struct rpc_task *task);
  59 static void     call_reserveresult(struct rpc_task *task);
  60 static void     call_allocate(struct rpc_task *task);
  61 static void     call_encode(struct rpc_task *task);
  62 static void     call_decode(struct rpc_task *task);
  63 static void     call_bind(struct rpc_task *task);
  64 static void     call_bind_status(struct rpc_task *task);
  65 static void     call_transmit(struct rpc_task *task);
  66 static void     call_status(struct rpc_task *task);
  67 static void     call_transmit_status(struct rpc_task *task);
  68 static void     call_refresh(struct rpc_task *task);
  69 static void     call_refreshresult(struct rpc_task *task);
  70 static void     call_timeout(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73 static __be32 * call_header(struct rpc_task *task);
  74 static __be32 * call_verify(struct rpc_task *task);
  75
  76 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  77
  78 static void rpc_register_client(struct rpc_clnt *clnt)
  79 {
  80         spin_lock(&rpc_client_lock);
  81         list_add(&clnt->cl_clients, &all_clients);
  82         spin_unlock(&rpc_client_lock);
  83 }
  84
  85 static void rpc_unregister_client(struct rpc_clnt *clnt)
  86 {
  87         spin_lock(&rpc_client_lock);
  88         list_del(&clnt->cl_clients);
  89         spin_unlock(&rpc_client_lock);
  90 }
  91
  92 static int
  93 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  94 {
  95         static uint32_t clntid;
  96         int error;
  97
  98         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  99         clnt->cl_dentry = ERR_PTR(-ENOENT);
 100         if (dir_name == NULL)
 101                 return 0;
 102
 103         clnt->cl_vfsmnt = rpc_get_mount();
 104         if (IS_ERR(clnt->cl_vfsmnt))
 105                 return PTR_ERR(clnt->cl_vfsmnt);
 106
 107         for (;;) {
 108                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 109                                 "%s/clnt%x", dir_name,
 110                                 (unsigned int)clntid++);
 111                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 112                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 113                 if (!IS_ERR(clnt->cl_dentry))
 114                         return 0;
 115                 error = PTR_ERR(clnt->cl_dentry);
 116                 if (error != -EEXIST) {
 117                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 118                                         clnt->cl_pathname, error);
 119                         rpc_put_mount();
 120                         return error;
 121                 }
 122         }
 123 }
 124
 125 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 126 {
 127         struct rpc_version      *version;
 128         struct rpc_clnt         *clnt = NULL;
 129         struct rpc_auth         *auth;
 130         int err;
 131         size_t len;
 132
 133         /* sanity check the name before trying to print it */
 134         err = -EINVAL;
 135         len = strlen(servname);
 136         if (len > RPC_MAXNETNAMELEN)
 137                 goto out_no_rpciod;
 138         len++;
 139
 140         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 141                         program->name, servname, xprt);
 142
 143         err = rpciod_up();
 144         if (err)
 145                 goto out_no_rpciod;
 146         err = -EINVAL;
 147         if (!xprt)
 148                 goto out_no_xprt;
 149         if (vers >= program->nrvers || !(version = program->version[vers]))
 150                 goto out_err;
 151
 152         err = -ENOMEM;
 153         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 154         if (!clnt)
 155                 goto out_err;
 156         clnt->cl_parent = clnt;
 157
 158         clnt->cl_server = clnt->cl_inline_name;
 159         if (len > sizeof(clnt->cl_inline_name)) {
 160                 char *buf = kmalloc(len, GFP_KERNEL);
 161                 if (buf != 0)
 162                         clnt->cl_server = buf;
 163                 else
 164                         len = sizeof(clnt->cl_inline_name);
 165         }
 166         strlcpy(clnt->cl_server, servname, len);
 167
 168         clnt->cl_xprt     = xprt;
 169         clnt->cl_procinfo = version->procs;
 170         clnt->cl_maxproc  = version->nrprocs;
 171         clnt->cl_protname = program->name;
 172         clnt->cl_prog     = program->number;
 173         clnt->cl_vers     = version->number;
 174         clnt->cl_stats    = program->stats;
 175         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 176         err = -ENOMEM;
 177         if (clnt->cl_metrics == NULL)
 178                 goto out_no_stats;
 179         clnt->cl_program  = program;
 180         INIT_LIST_HEAD(&clnt->cl_tasks);
 181         spin_lock_init(&clnt->cl_lock);
 182
 183         if (!xprt_bound(clnt->cl_xprt))
 184                 clnt->cl_autobind = 1;
 185
 186         clnt->cl_rtt = &clnt->cl_rtt_default;
 187         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 188
 189         kref_init(&clnt->cl_kref);
 190
 191         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 192         if (err < 0)
 193                 goto out_no_path;
 194
 195         auth = rpcauth_create(flavor, clnt);
 196         if (IS_ERR(auth)) {
 197                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 198                                 flavor);
 199                 err = PTR_ERR(auth);
 200                 goto out_no_auth;
 201         }
 202
 203         /* save the nodename */
 204         clnt->cl_nodelen = strlen(utsname()->nodename);
 205         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 206                 clnt->cl_nodelen = UNX_MAXNODENAME;
 207         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 208         rpc_register_client(clnt);
 209         return clnt;
 210
 211 out_no_auth:
 212         if (!IS_ERR(clnt->cl_dentry)) {
 213                 rpc_rmdir(clnt->cl_dentry);
 214                 rpc_put_mount();
 215         }
 216 out_no_path:
 217         rpc_free_iostats(clnt->cl_metrics);
 218 out_no_stats:
 219         if (clnt->cl_server != clnt->cl_inline_name)
 220                 kfree(clnt->cl_server);
 221         kfree(clnt);
 222 out_err:
 223         xprt_put(xprt);
 224 out_no_xprt:
 225         rpciod_down();
 226 out_no_rpciod:
 227         return ERR_PTR(err);
 228 }
 229
 230 /*
 231  * rpc_create - create an RPC client and transport with one call
 232  * @args: rpc_clnt create argument structure
 233  *
 234  * Creates and initializes an RPC transport and an RPC client.
 235  *
 236  * It can ping the server in order to determine if it is up, and to see if
 237  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 238  * this behavior so asynchronous tasks can also use rpc_create.
 239  */
 240 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 241 {
 242         struct rpc_xprt *xprt;
 243         struct rpc_clnt *clnt;
 244         struct xprt_create xprtargs = {
 245                 .ident = args->protocol,
 246                 .srcaddr = args->saddress,
 247                 .dstaddr = args->address,
 248                 .addrlen = args->addrsize,
 249                 .timeout = args->timeout
 250         };
 251         char servername[48];
 252
 253         xprt = xprt_create_transport(&xprtargs);
 254         if (IS_ERR(xprt))
 255                 return (struct rpc_clnt *)xprt;
 256
 257         /*
 258          * If the caller chooses not to specify a hostname, whip
 259          * up a string representation of the passed-in address.
 260          */
 261         if (args->servername == NULL) {
 262                 servername[0] = '\0';
 263                 switch (args->address->sa_family) {
 264                 case AF_INET: {
 265                         struct sockaddr_in *sin =
 266                                         (struct sockaddr_in *)args->address;
 267                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 268                                  NIPQUAD(sin->sin_addr.s_addr));
 269                         break;
 270                 }
 271                 case AF_INET6: {
 272                         struct sockaddr_in6 *sin =
 273                                         (struct sockaddr_in6 *)args->address;
 274                         snprintf(servername, sizeof(servername), NIP6_FMT,
 275                                  NIP6(sin->sin6_addr));
 276                         break;
 277                 }
 278                 default:
 279                         /* caller wants default server name, but
 280                          * address family isn't recognized. */
 281                         return ERR_PTR(-EINVAL);
 282                 }
 283                 args->servername = servername;
 284         }
 285
 286         xprt = xprt_create_transport(&xprtargs);
 287         if (IS_ERR(xprt))
 288                 return (struct rpc_clnt *)xprt;
 289
 290         /*
 291          * By default, kernel RPC client connects from a reserved port.
 292          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 293          * but it is always enabled for rpciod, which handles the connect
 294          * operation.
 295          */
 296         xprt->resvport = 1;
 297         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 298                 xprt->resvport = 0;
 299
 300         clnt = rpc_new_client(xprt, args->servername, args->program,
 301                                 args->version, args->authflavor);
 302         if (IS_ERR(clnt))
 303                 return clnt;
 304
 305         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 306                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 307                 if (err != 0) {
 308                         rpc_shutdown_client(clnt);
 309                         return ERR_PTR(err);
 310                 }
 311         }
 312
 313         clnt->cl_softrtry = 1;
 314         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 315                 clnt->cl_softrtry = 0;
 316
 317         if (args->flags & RPC_CLNT_CREATE_INTR)
 318                 clnt->cl_intr = 1;
 319         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 320                 clnt->cl_autobind = 1;
 321         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 322                 clnt->cl_discrtry = 1;
 323
 324         return clnt;
 325 }
 326 EXPORT_SYMBOL_GPL(rpc_create);
 327
 328 /*
 329  * This function clones the RPC client structure. It allows us to share the
 330  * same transport while varying parameters such as the authentication
 331  * flavour.
 332  */
 333 struct rpc_clnt *
 334 rpc_clone_client(struct rpc_clnt *clnt)
 335 {
 336         struct rpc_clnt *new;
 337         int err = -ENOMEM;
 338
 339         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 340         if (!new)
 341                 goto out_no_clnt;
 342         new->cl_parent = clnt;
 343         /* Turn off autobind on clones */
 344         new->cl_autobind = 0;
 345         INIT_LIST_HEAD(&new->cl_tasks);
 346         spin_lock_init(&new->cl_lock);
 347         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 348         new->cl_metrics = rpc_alloc_iostats(clnt);
 349         if (new->cl_metrics == NULL)
 350                 goto out_no_stats;
 351         kref_init(&new->cl_kref);
 352         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 353         if (err != 0)
 354                 goto out_no_path;
 355         if (new->cl_auth)
 356                 atomic_inc(&new->cl_auth->au_count);
 357         xprt_get(clnt->cl_xprt);
 358         kref_get(&clnt->cl_kref);
 359         rpc_register_client(new);
 360         rpciod_up();
 361         return new;
 362 out_no_path:
 363         rpc_free_iostats(new->cl_metrics);
 364 out_no_stats:
 365         kfree(new);
 366 out_no_clnt:
 367         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 368         return ERR_PTR(err);
 369 }
 370 EXPORT_SYMBOL_GPL(rpc_clone_client);
 371
 372 /*
 373  * Properly shut down an RPC client, terminating all outstanding
 374  * requests.
 375  */
 376 void rpc_shutdown_client(struct rpc_clnt *clnt)
 377 {
 378         dprintk("RPC:       shutting down %s client for %s\n",
 379                         clnt->cl_protname, clnt->cl_server);
 380
 381         while (!list_empty(&clnt->cl_tasks)) {
 382                 rpc_killall_tasks(clnt);
 383                 wait_event_timeout(destroy_wait,
 384                         list_empty(&clnt->cl_tasks), 1*HZ);
 385         }
 386
 387         rpc_release_client(clnt);
 388 }
 389 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 390
 391 /*
 392  * Free an RPC client
 393  */
 394 static void
 395 rpc_free_client(struct kref *kref)
 396 {
 397         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 398
 399         dprintk("RPC:       destroying %s client for %s\n",
 400                         clnt->cl_protname, clnt->cl_server);
 401         if (!IS_ERR(clnt->cl_dentry)) {
 402                 rpc_rmdir(clnt->cl_dentry);
 403                 rpc_put_mount();
 404         }
 405         if (clnt->cl_parent != clnt) {
 406                 rpc_release_client(clnt->cl_parent);
 407                 goto out_free;
 408         }
 409         if (clnt->cl_server != clnt->cl_inline_name)
 410                 kfree(clnt->cl_server);
 411 out_free:
 412         rpc_unregister_client(clnt);
 413         rpc_free_iostats(clnt->cl_metrics);
 414         clnt->cl_metrics = NULL;
 415         xprt_put(clnt->cl_xprt);
 416         rpciod_down();
 417         kfree(clnt);
 418 }
 419
 420 /*
 421  * Free an RPC client
 422  */
 423 static void
 424 rpc_free_auth(struct kref *kref)
 425 {
 426         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 427
 428         if (clnt->cl_auth == NULL) {
 429                 rpc_free_client(kref);
 430                 return;
 431         }
 432
 433         /*
 434          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 435          *       release remaining GSS contexts. This mechanism ensures
 436          *       that it can do so safely.
 437          */
 438         kref_init(kref);
 439         rpcauth_release(clnt->cl_auth);
 440         clnt->cl_auth = NULL;
 441         kref_put(kref, rpc_free_client);
 442 }
 443
 444 /*
 445  * Release reference to the RPC client
 446  */
 447 void
 448 rpc_release_client(struct rpc_clnt *clnt)
 449 {
 450         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 451
 452         if (list_empty(&clnt->cl_tasks))
 453                 wake_up(&destroy_wait);
 454         kref_put(&clnt->cl_kref, rpc_free_auth);
 455 }
 456
 457 /**
 458  * rpc_bind_new_program - bind a new RPC program to an existing client
 459  * @old - old rpc_client
 460  * @program - rpc program to set
 461  * @vers - rpc program version
 462  *
 463  * Clones the rpc client and sets up a new RPC program. This is mainly
 464  * of use for enabling different RPC programs to share the same transport.
 465  * The Sun NFSv2/v3 ACL protocol can do this.
 466  */
 467 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 468                                       struct rpc_program *program,
 469                                       u32 vers)
 470 {
 471         struct rpc_clnt *clnt;
 472         struct rpc_version *version;
 473         int err;
 474
 475         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 476         version = program->version[vers];
 477         clnt = rpc_clone_client(old);
 478         if (IS_ERR(clnt))
 479                 goto out;
 480         clnt->cl_procinfo = version->procs;
 481         clnt->cl_maxproc  = version->nrprocs;
 482         clnt->cl_protname = program->name;
 483         clnt->cl_prog     = program->number;
 484         clnt->cl_vers     = version->number;
 485         clnt->cl_stats    = program->stats;
 486         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 487         if (err != 0) {
 488                 rpc_shutdown_client(clnt);
 489                 clnt = ERR_PTR(err);
 490         }
 491 out:
 492         return clnt;
 493 }
 494 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 495
 496 /*
 497  * Default callback for async RPC calls
 498  */
 499 static void
 500 rpc_default_callback(struct rpc_task *task, void *data)
 501 {
 502 }
 503
 504 static const struct rpc_call_ops rpc_default_ops = {
 505         .rpc_call_done = rpc_default_callback,
 506 };
 507
 508 /*
 509  *      Export the signal mask handling for synchronous code that
 510  *      sleeps on RPC calls
 511  */
 512 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 513
 514 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 515 {
 516         unsigned long   sigallow = sigmask(SIGKILL);
 517         sigset_t sigmask;
 518
 519         /* Block all signals except those listed in sigallow */
 520         if (intr)
 521                 sigallow |= RPC_INTR_SIGNALS;
 522         siginitsetinv(&sigmask, sigallow);
 523         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 524 }
 525
 526 static void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 527 {
 528         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 529 }
 530
 531 static void rpc_restore_sigmask(sigset_t *oldset)
 532 {
 533         sigprocmask(SIG_SETMASK, oldset, NULL);
 534 }
 535
 536 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 537 {
 538         rpc_save_sigmask(oldset, clnt->cl_intr);
 539 }
 540 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 541
 542 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 543 {
 544         rpc_restore_sigmask(oldset);
 545 }
 546 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 547
 548 /**
 549  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 550  * @task_setup_data: pointer to task initialisation data
 551  */
 552 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 553 {
 554         struct rpc_task *task, *ret;
 555         sigset_t oldset;
 556
 557         task = rpc_new_task(task_setup_data);
 558         if (task == NULL) {
 559                 rpc_release_calldata(task_setup_data->callback_ops,
 560                                 task_setup_data->callback_data);
 561                 ret = ERR_PTR(-ENOMEM);
 562                 goto out;
 563         }
 564
 565         if (task->tk_status != 0) {
 566                 ret = ERR_PTR(task->tk_status);
 567                 rpc_put_task(task);
 568                 goto out;
 569         }
 570         atomic_inc(&task->tk_count);
 571         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 572         rpc_task_sigmask(task, &oldset);
 573         rpc_execute(task);
 574         rpc_restore_sigmask(&oldset);
 575         ret = task;
 576 out:
 577         return ret;
 578 }
 579 EXPORT_SYMBOL_GPL(rpc_run_task);
 580
 581 /**
 582  * rpc_call_sync - Perform a synchronous RPC call
 583  * @clnt: pointer to RPC client
 584  * @msg: RPC call parameters
 585  * @flags: RPC call flags
 586  */
 587 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 588 {
 589         struct rpc_task *task;
 590         struct rpc_task_setup task_setup_data = {
 591                 .rpc_client = clnt,
 592                 .rpc_message = msg,
 593                 .callback_ops = &rpc_default_ops,
 594                 .flags = flags,
 595         };
 596         int status;
 597
 598         BUG_ON(flags & RPC_TASK_ASYNC);
 599
 600         task = rpc_run_task(&task_setup_data);
 601         if (IS_ERR(task))
 602                 return PTR_ERR(task);
 603         status = task->tk_status;
 604         rpc_put_task(task);
 605         return status;
 606 }
 607 EXPORT_SYMBOL_GPL(rpc_call_sync);
 608
 609 /**
 610  * rpc_call_async - Perform an asynchronous RPC call
 611  * @clnt: pointer to RPC client
 612  * @msg: RPC call parameters
 613  * @flags: RPC call flags
 614  * @ops: RPC call ops
 615  * @data: user call data
 616  */
 617 int
 618 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 619                const struct rpc_call_ops *tk_ops, void *data)
 620 {
 621         struct rpc_task *task;
 622         struct rpc_task_setup task_setup_data = {
 623                 .rpc_client = clnt,
 624                 .rpc_message = msg,
 625                 .callback_ops = tk_ops,
 626                 .callback_data = data,
 627                 .flags = flags|RPC_TASK_ASYNC,
 628         };
 629
 630         task = rpc_run_task(&task_setup_data);
 631         if (IS_ERR(task))
 632                 return PTR_ERR(task);
 633         rpc_put_task(task);
 634         return 0;
 635 }
 636 EXPORT_SYMBOL_GPL(rpc_call_async);
 637
 638 void
 639 rpc_call_start(struct rpc_task *task)
 640 {
 641         task->tk_action = call_start;
 642 }
 643 EXPORT_SYMBOL_GPL(rpc_call_start);
 644
 645 /**
 646  * rpc_peeraddr - extract remote peer address from clnt's xprt
 647  * @clnt: RPC client structure
 648  * @buf: target buffer
 649  * @size: length of target buffer
 650  *
 651  * Returns the number of bytes that are actually in the stored address.
 652  */
 653 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 654 {
 655         size_t bytes;
 656         struct rpc_xprt *xprt = clnt->cl_xprt;
 657
 658         bytes = sizeof(xprt->addr);
 659         if (bytes > bufsize)
 660                 bytes = bufsize;
 661         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 662         return xprt->addrlen;
 663 }
 664 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 665
 666 /**
 667  * rpc_peeraddr2str - return remote peer address in printable format
 668  * @clnt: RPC client structure
 669  * @format: address format
 670  *
 671  */
 672 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 673 {
 674         struct rpc_xprt *xprt = clnt->cl_xprt;
 675
 676         if (xprt->address_strings[format] != NULL)
 677                 return xprt->address_strings[format];
 678         else
 679                 return "unprintable";
 680 }
 681 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 682
 683 void
 684 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 685 {
 686         struct rpc_xprt *xprt = clnt->cl_xprt;
 687         if (xprt->ops->set_buffer_size)
 688                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 691
 692 /*
 693  * Return size of largest payload RPC client can support, in bytes
 694  *
 695  * For stream transports, this is one RPC record fragment (see RFC
 696  * 1831), as we don't support multi-record requests yet.  For datagram
 697  * transports, this is the size of an IP packet minus the IP, UDP, and
 698  * RPC header sizes.
 699  */
 700 size_t rpc_max_payload(struct rpc_clnt *clnt)
 701 {
 702         return clnt->cl_xprt->max_payload;
 703 }
 704 EXPORT_SYMBOL_GPL(rpc_max_payload);
 705
 706 /**
 707  * rpc_force_rebind - force transport to check that remote port is unchanged
 708  * @clnt: client to rebind
 709  *
 710  */
 711 void rpc_force_rebind(struct rpc_clnt *clnt)
 712 {
 713         if (clnt->cl_autobind)
 714                 xprt_clear_bound(clnt->cl_xprt);
 715 }
 716 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 717
 718 /*
 719  * Restart an (async) RPC call. Usually called from within the
 720  * exit handler.
 721  */
 722 void
 723 rpc_restart_call(struct rpc_task *task)
 724 {
 725         if (RPC_ASSASSINATED(task))
 726                 return;
 727
 728         task->tk_action = call_start;
 729 }
 730 EXPORT_SYMBOL_GPL(rpc_restart_call);
 731
 732 /*
 733  * 0.  Initial state
 734  *
 735  *     Other FSM states can be visited zero or more times, but
 736  *     this state is visited exactly once for each RPC.
 737  */
 738 static void
 739 call_start(struct rpc_task *task)
 740 {
 741         struct rpc_clnt *clnt = task->tk_client;
 742
 743         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 744                         clnt->cl_protname, clnt->cl_vers,
 745                         task->tk_msg.rpc_proc->p_proc,
 746                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 747
 748         /* Increment call count */
 749         task->tk_msg.rpc_proc->p_count++;
 750         clnt->cl_stats->rpccnt++;
 751         task->tk_action = call_reserve;
 752 }
 753
 754 /*
 755  * 1.   Reserve an RPC call slot
 756  */
 757 static void
 758 call_reserve(struct rpc_task *task)
 759 {
 760         dprint_status(task);
 761
 762         if (!rpcauth_uptodatecred(task)) {
 763                 task->tk_action = call_refresh;
 764                 return;
 765         }
 766
 767         task->tk_status  = 0;
 768         task->tk_action  = call_reserveresult;
 769         xprt_reserve(task);
 770 }
 771
 772 /*
 773  * 1b.  Grok the result of xprt_reserve()
 774  */
 775 static void
 776 call_reserveresult(struct rpc_task *task)
 777 {
 778         int status = task->tk_status;
 779
 780         dprint_status(task);
 781
 782         /*
 783          * After a call to xprt_reserve(), we must have either
 784          * a request slot or else an error status.
 785          */
 786         task->tk_status = 0;
 787         if (status >= 0) {
 788                 if (task->tk_rqstp) {
 789                         task->tk_action = call_allocate;
 790                         return;
 791                 }
 792
 793                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 794                                 __FUNCTION__, status);
 795                 rpc_exit(task, -EIO);
 796                 return;
 797         }
 798
 799         /*
 800          * Even though there was an error, we may have acquired
 801          * a request slot somehow.  Make sure not to leak it.
 802          */
 803         if (task->tk_rqstp) {
 804                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 805                                 __FUNCTION__, status);
 806                 xprt_release(task);
 807         }
 808
 809         switch (status) {
 810         case -EAGAIN:   /* woken up; retry */
 811                 task->tk_action = call_reserve;
 812                 return;
 813         case -EIO:      /* probably a shutdown */
 814                 break;
 815         default:
 816                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 817                                 __FUNCTION__, status);
 818                 break;
 819         }
 820         rpc_exit(task, status);
 821 }
 822
 823 /*
 824  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 825  *      (Note: buffer memory is freed in xprt_release).
 826  */
 827 static void
 828 call_allocate(struct rpc_task *task)
 829 {
 830         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 831         struct rpc_rqst *req = task->tk_rqstp;
 832         struct rpc_xprt *xprt = task->tk_xprt;
 833         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 834
 835         dprint_status(task);
 836
 837         task->tk_status = 0;
 838         task->tk_action = call_bind;
 839
 840         if (req->rq_buffer)
 841                 return;
 842
 843         if (proc->p_proc != 0) {
 844                 BUG_ON(proc->p_arglen == 0);
 845                 if (proc->p_decode != NULL)
 846                         BUG_ON(proc->p_replen == 0);
 847         }
 848
 849         /*
 850          * Calculate the size (in quads) of the RPC call
 851          * and reply headers, and convert both values
 852          * to byte sizes.
 853          */
 854         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 855         req->rq_callsize <<= 2;
 856         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 857         req->rq_rcvsize <<= 2;
 858
 859         req->rq_buffer = xprt->ops->buf_alloc(task,
 860                                         req->rq_callsize + req->rq_rcvsize);
 861         if (req->rq_buffer != NULL)
 862                 return;
 863
 864         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 865
 866         if (RPC_IS_ASYNC(task) || !signalled()) {
 867                 task->tk_action = call_allocate;
 868                 rpc_delay(task, HZ>>4);
 869                 return;
 870         }
 871
 872         rpc_exit(task, -ERESTARTSYS);
 873 }
 874
 875 static inline int
 876 rpc_task_need_encode(struct rpc_task *task)
 877 {
 878         return task->tk_rqstp->rq_snd_buf.len == 0;
 879 }
 880
 881 static inline void
 882 rpc_task_force_reencode(struct rpc_task *task)
 883 {
 884         task->tk_rqstp->rq_snd_buf.len = 0;
 885 }
 886
 887 static inline void
 888 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 889 {
 890         buf->head[0].iov_base = start;
 891         buf->head[0].iov_len = len;
 892         buf->tail[0].iov_len = 0;
 893         buf->page_len = 0;
 894         buf->flags = 0;
 895         buf->len = 0;
 896         buf->buflen = len;
 897 }
 898
 899 /*
 900  * 3.   Encode arguments of an RPC call
 901  */
 902 static void
 903 call_encode(struct rpc_task *task)
 904 {
 905         struct rpc_rqst *req = task->tk_rqstp;
 906         kxdrproc_t      encode;
 907         __be32          *p;
 908
 909         dprint_status(task);
 910
 911         rpc_xdr_buf_init(&req->rq_snd_buf,
 912                          req->rq_buffer,
 913                          req->rq_callsize);
 914         rpc_xdr_buf_init(&req->rq_rcv_buf,
 915                          (char *)req->rq_buffer + req->rq_callsize,
 916                          req->rq_rcvsize);
 917
 918         /* Encode header and provided arguments */
 919         encode = task->tk_msg.rpc_proc->p_encode;
 920         if (!(p = call_header(task))) {
 921                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 922                 rpc_exit(task, -EIO);
 923                 return;
 924         }
 925         if (encode == NULL)
 926                 return;
 927
 928         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 929                         task->tk_msg.rpc_argp);
 930         if (task->tk_status == -ENOMEM) {
 931                 /* XXX: Is this sane? */
 932                 rpc_delay(task, 3*HZ);
 933                 task->tk_status = -EAGAIN;
 934         }
 935 }
 936
 937 /*
 938  * 4.   Get the server port number if not yet set
 939  */
 940 static void
 941 call_bind(struct rpc_task *task)
 942 {
 943         struct rpc_xprt *xprt = task->tk_xprt;
 944
 945         dprint_status(task);
 946
 947         task->tk_action = call_connect;
 948         if (!xprt_bound(xprt)) {
 949                 task->tk_action = call_bind_status;
 950                 task->tk_timeout = xprt->bind_timeout;
 951                 xprt->ops->rpcbind(task);
 952         }
 953 }
 954
 955 /*
 956  * 4a.  Sort out bind result
 957  */
 958 static void
 959 call_bind_status(struct rpc_task *task)
 960 {
 961         int status = -EIO;
 962
 963         if (task->tk_status >= 0) {
 964                 dprint_status(task);
 965                 task->tk_status = 0;
 966                 task->tk_action = call_connect;
 967                 return;
 968         }
 969
 970         switch (task->tk_status) {
 971         case -EAGAIN:
 972                 dprintk("RPC: %5u rpcbind waiting for another request "
 973                                 "to finish\n", task->tk_pid);
 974                 /* avoid busy-waiting here -- could be a network outage. */
 975                 rpc_delay(task, 5*HZ);
 976                 goto retry_timeout;
 977         case -EACCES:
 978                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 979                                 "unavailable\n", task->tk_pid);
 980                 /* fail immediately if this is an RPC ping */
 981                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 982                         status = -EOPNOTSUPP;
 983                         break;
 984                 }
 985                 rpc_delay(task, 3*HZ);
 986                 goto retry_timeout;
 987         case -ETIMEDOUT:
 988                 dprintk("RPC: %5u rpcbind request timed out\n",
 989                                 task->tk_pid);
 990                 goto retry_timeout;
 991         case -EPFNOSUPPORT:
 992                 /* server doesn't support any rpcbind version we know of */
 993                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 994                                 task->tk_pid);
 995                 break;
 996         case -EPROTONOSUPPORT:
 997                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 998                                 task->tk_pid);
 999                 task->tk_status = 0;
1000                 task->tk_action = call_bind;
1001                 return;
1002         default:
1003                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1004                                 task->tk_pid, -task->tk_status);
1005         }
1006
1007         rpc_exit(task, status);
1008         return;
1009
1010 retry_timeout:
1011         task->tk_action = call_timeout;
1012 }
1013
1014 /*
1015  * 4b.  Connect to the RPC server
1016  */
1017 static void
1018 call_connect(struct rpc_task *task)
1019 {
1020         struct rpc_xprt *xprt = task->tk_xprt;
1021
1022         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1023                         task->tk_pid, xprt,
1024                         (xprt_connected(xprt) ? "is" : "is not"));
1025
1026         task->tk_action = call_transmit;
1027         if (!xprt_connected(xprt)) {
1028                 task->tk_action = call_connect_status;
1029                 if (task->tk_status < 0)
1030                         return;
1031                 xprt_connect(task);
1032         }
1033 }
1034
1035 /*
1036  * 4c.  Sort out connect result
1037  */
1038 static void
1039 call_connect_status(struct rpc_task *task)
1040 {
1041         struct rpc_clnt *clnt = task->tk_client;
1042         int status = task->tk_status;
1043
1044         dprint_status(task);
1045
1046         task->tk_status = 0;
1047         if (status >= 0) {
1048                 clnt->cl_stats->netreconn++;
1049                 task->tk_action = call_transmit;
1050                 return;
1051         }
1052
1053         /* Something failed: remote service port may have changed */
1054         rpc_force_rebind(clnt);
1055
1056         switch (status) {
1057         case -ENOTCONN:
1058         case -EAGAIN:
1059                 task->tk_action = call_bind;
1060                 if (!RPC_IS_SOFT(task))
1061                         return;
1062                 /* if soft mounted, test if we've timed out */
1063         case -ETIMEDOUT:
1064                 task->tk_action = call_timeout;
1065                 return;
1066         }
1067         rpc_exit(task, -EIO);
1068 }
1069
1070 /*
1071  * 5.   Transmit the RPC request, and wait for reply
1072  */
1073 static void
1074 call_transmit(struct rpc_task *task)
1075 {
1076         dprint_status(task);
1077
1078         task->tk_action = call_status;
1079         if (task->tk_status < 0)
1080                 return;
1081         task->tk_status = xprt_prepare_transmit(task);
1082         if (task->tk_status != 0)
1083                 return;
1084         task->tk_action = call_transmit_status;
1085         /* Encode here so that rpcsec_gss can use correct sequence number. */
1086         if (rpc_task_need_encode(task)) {
1087                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1088                 call_encode(task);
1089                 /* Did the encode result in an error condition? */
1090                 if (task->tk_status != 0)
1091                         return;
1092         }
1093         xprt_transmit(task);
1094         if (task->tk_status < 0)
1095                 return;
1096         /*
1097          * On success, ensure that we call xprt_end_transmit() before sleeping
1098          * in order to allow access to the socket to other RPC requests.
1099          */
1100         call_transmit_status(task);
1101         if (task->tk_msg.rpc_proc->p_decode != NULL)
1102                 return;
1103         task->tk_action = rpc_exit_task;
1104         rpc_wake_up_task(task);
1105 }
1106
1107 /*
1108  * 5a.  Handle cleanup after a transmission
1109  */
1110 static void
1111 call_transmit_status(struct rpc_task *task)
1112 {
1113         task->tk_action = call_status;
1114         /*
1115          * Special case: if we've been waiting on the socket's write_space()
1116          * callback, then don't call xprt_end_transmit().
1117          */
1118         if (task->tk_status == -EAGAIN)
1119                 return;
1120         xprt_end_transmit(task);
1121         rpc_task_force_reencode(task);
1122 }
1123
1124 /*
1125  * 6.   Sort out the RPC call status
1126  */
1127 static void
1128 call_status(struct rpc_task *task)
1129 {
1130         struct rpc_clnt *clnt = task->tk_client;
1131         struct rpc_rqst *req = task->tk_rqstp;
1132         int             status;
1133
1134         if (req->rq_received > 0 && !req->rq_bytes_sent)
1135                 task->tk_status = req->rq_received;
1136
1137         dprint_status(task);
1138
1139         status = task->tk_status;
1140         if (status >= 0) {
1141                 task->tk_action = call_decode;
1142                 return;
1143         }
1144
1145         task->tk_status = 0;
1146         switch(status) {
1147         case -EHOSTDOWN:
1148         case -EHOSTUNREACH:
1149         case -ENETUNREACH:
1150                 /*
1151                  * Delay any retries for 3 seconds, then handle as if it
1152                  * were a timeout.
1153                  */
1154                 rpc_delay(task, 3*HZ);
1155         case -ETIMEDOUT:
1156                 task->tk_action = call_timeout;
1157                 if (task->tk_client->cl_discrtry)
1158                         xprt_force_disconnect(task->tk_xprt);
1159                 break;
1160         case -ECONNREFUSED:
1161         case -ENOTCONN:
1162                 rpc_force_rebind(clnt);
1163                 task->tk_action = call_bind;
1164                 break;
1165         case -EAGAIN:
1166                 task->tk_action = call_transmit;
1167                 break;
1168         case -EIO:
1169                 /* shutdown or soft timeout */
1170                 rpc_exit(task, status);
1171                 break;
1172         default:
1173                 printk("%s: RPC call returned error %d\n",
1174                                clnt->cl_protname, -status);
1175                 rpc_exit(task, status);
1176         }
1177 }
1178
1179 /*
1180  * 6a.  Handle RPC timeout
1181  *      We do not release the request slot, so we keep using the
1182  *      same XID for all retransmits.
1183  */
1184 static void
1185 call_timeout(struct rpc_task *task)
1186 {
1187         struct rpc_clnt *clnt = task->tk_client;
1188
1189         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1190                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1191                 goto retry;
1192         }
1193
1194         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1195         task->tk_timeouts++;
1196
1197         if (RPC_IS_SOFT(task)) {
1198                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1199                                 clnt->cl_protname, clnt->cl_server);
1200                 rpc_exit(task, -EIO);
1201                 return;
1202         }
1203
1204         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1205                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1206                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1207                         clnt->cl_protname, clnt->cl_server);
1208         }
1209         rpc_force_rebind(clnt);
1210
1211 retry:
1212         clnt->cl_stats->rpcretrans++;
1213         task->tk_action = call_bind;
1214         task->tk_status = 0;
1215 }
1216
1217 /*
1218  * 7.   Decode the RPC reply
1219  */
1220 static void
1221 call_decode(struct rpc_task *task)
1222 {
1223         struct rpc_clnt *clnt = task->tk_client;
1224         struct rpc_rqst *req = task->tk_rqstp;
1225         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1226         __be32          *p;
1227
1228         dprintk("RPC: %5u call_decode (status %d)\n",
1229                         task->tk_pid, task->tk_status);
1230
1231         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1232                 printk(KERN_NOTICE "%s: server %s OK\n",
1233                         clnt->cl_protname, clnt->cl_server);
1234                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1235         }
1236
1237         if (task->tk_status < 12) {
1238                 if (!RPC_IS_SOFT(task)) {
1239                         task->tk_action = call_bind;
1240                         clnt->cl_stats->rpcretrans++;
1241                         goto out_retry;
1242                 }
1243                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1244                                 clnt->cl_protname, task->tk_status);
1245                 task->tk_action = call_timeout;
1246                 goto out_retry;
1247         }
1248
1249         /*
1250          * Ensure that we see all writes made by xprt_complete_rqst()
1251          * before it changed req->rq_received.
1252          */
1253         smp_rmb();
1254         req->rq_rcv_buf.len = req->rq_private_buf.len;
1255
1256         /* Check that the softirq receive buffer is valid */
1257         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1258                                 sizeof(req->rq_rcv_buf)) != 0);
1259
1260         /* Verify the RPC header */
1261         p = call_verify(task);
1262         if (IS_ERR(p)) {
1263                 if (p == ERR_PTR(-EAGAIN))
1264                         goto out_retry;
1265                 return;
1266         }
1267
1268         task->tk_action = rpc_exit_task;
1269
1270         if (decode) {
1271                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1272                                                       task->tk_msg.rpc_resp);
1273         }
1274         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1275                         task->tk_status);
1276         return;
1277 out_retry:
1278         req->rq_received = req->rq_private_buf.len = 0;
1279         task->tk_status = 0;
1280         if (task->tk_client->cl_discrtry)
1281                 xprt_force_disconnect(task->tk_xprt);
1282 }
1283
1284 /*
1285  * 8.   Refresh the credentials if rejected by the server
1286  */
1287 static void
1288 call_refresh(struct rpc_task *task)
1289 {
1290         dprint_status(task);
1291
1292         task->tk_action = call_refreshresult;
1293         task->tk_status = 0;
1294         task->tk_client->cl_stats->rpcauthrefresh++;
1295         rpcauth_refreshcred(task);
1296 }
1297
1298 /*
1299  * 8a.  Process the results of a credential refresh
1300  */
1301 static void
1302 call_refreshresult(struct rpc_task *task)
1303 {
1304         int status = task->tk_status;
1305
1306         dprint_status(task);
1307
1308         task->tk_status = 0;
1309         task->tk_action = call_reserve;
1310         if (status >= 0 && rpcauth_uptodatecred(task))
1311                 return;
1312         if (status == -EACCES) {
1313                 rpc_exit(task, -EACCES);
1314                 return;
1315         }
1316         task->tk_action = call_refresh;
1317         if (status != -ETIMEDOUT)
1318                 rpc_delay(task, 3*HZ);
1319         return;
1320 }
1321
1322 /*
1323  * Call header serialization
1324  */
1325 static __be32 *
1326 call_header(struct rpc_task *task)
1327 {
1328         struct rpc_clnt *clnt = task->tk_client;
1329         struct rpc_rqst *req = task->tk_rqstp;
1330         __be32          *p = req->rq_svec[0].iov_base;
1331
1332         /* FIXME: check buffer size? */
1333
1334         p = xprt_skip_transport_header(task->tk_xprt, p);
1335         *p++ = req->rq_xid;             /* XID */
1336         *p++ = htonl(RPC_CALL);         /* CALL */
1337         *p++ = htonl(RPC_VERSION);      /* RPC version */
1338         *p++ = htonl(clnt->cl_prog);    /* program number */
1339         *p++ = htonl(clnt->cl_vers);    /* program version */
1340         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1341         p = rpcauth_marshcred(task, p);
1342         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1343         return p;
1344 }
1345
1346 /*
1347  * Reply header verification
1348  */
1349 static __be32 *
1350 call_verify(struct rpc_task *task)
1351 {
1352         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1353         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1354         __be32  *p = iov->iov_base;
1355         u32 n;
1356         int error = -EACCES;
1357
1358         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1359                 /* RFC-1014 says that the representation of XDR data must be a
1360                  * multiple of four bytes
1361                  * - if it isn't pointer subtraction in the NFS client may give
1362                  *   undefined results
1363                  */
1364                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1365                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1366                        task->tk_rqstp->rq_rcv_buf.len);
1367                 goto out_eio;
1368         }
1369         if ((len -= 3) < 0)
1370                 goto out_overflow;
1371         p += 1; /* skip XID */
1372
1373         if ((n = ntohl(*p++)) != RPC_REPLY) {
1374                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1375                                 task->tk_pid, __FUNCTION__, n);
1376                 goto out_garbage;
1377         }
1378         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1379                 if (--len < 0)
1380                         goto out_overflow;
1381                 switch ((n = ntohl(*p++))) {
1382                         case RPC_AUTH_ERROR:
1383                                 break;
1384                         case RPC_MISMATCH:
1385                                 dprintk("RPC: %5u %s: RPC call version "
1386                                                 "mismatch!\n",
1387                                                 task->tk_pid, __FUNCTION__);
1388                                 error = -EPROTONOSUPPORT;
1389                                 goto out_err;
1390                         default:
1391                                 dprintk("RPC: %5u %s: RPC call rejected, "
1392                                                 "unknown error: %x\n",
1393                                                 task->tk_pid, __FUNCTION__, n);
1394                                 goto out_eio;
1395                 }
1396                 if (--len < 0)
1397                         goto out_overflow;
1398                 switch ((n = ntohl(*p++))) {
1399                 case RPC_AUTH_REJECTEDCRED:
1400                 case RPC_AUTH_REJECTEDVERF:
1401                 case RPCSEC_GSS_CREDPROBLEM:
1402                 case RPCSEC_GSS_CTXPROBLEM:
1403                         if (!task->tk_cred_retry)
1404                                 break;
1405                         task->tk_cred_retry--;
1406                         dprintk("RPC: %5u %s: retry stale creds\n",
1407                                         task->tk_pid, __FUNCTION__);
1408                         rpcauth_invalcred(task);
1409                         /* Ensure we obtain a new XID! */
1410                         xprt_release(task);
1411                         task->tk_action = call_refresh;
1412                         goto out_retry;
1413                 case RPC_AUTH_BADCRED:
1414                 case RPC_AUTH_BADVERF:
1415                         /* possibly garbled cred/verf? */
1416                         if (!task->tk_garb_retry)
1417                                 break;
1418                         task->tk_garb_retry--;
1419                         dprintk("RPC: %5u %s: retry garbled creds\n",
1420                                         task->tk_pid, __FUNCTION__);
1421                         task->tk_action = call_bind;
1422                         goto out_retry;
1423                 case RPC_AUTH_TOOWEAK:
1424                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1425                                "authentication.\n", task->tk_client->cl_server);
1426                         break;
1427                 default:
1428                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1429                                         task->tk_pid, __FUNCTION__, n);
1430                         error = -EIO;
1431                 }
1432                 dprintk("RPC: %5u %s: call rejected %d\n",
1433                                 task->tk_pid, __FUNCTION__, n);
1434                 goto out_err;
1435         }
1436         if (!(p = rpcauth_checkverf(task, p))) {
1437                 dprintk("RPC: %5u %s: auth check failed\n",
1438                                 task->tk_pid, __FUNCTION__);
1439                 goto out_garbage;               /* bad verifier, retry */
1440         }
1441         len = p - (__be32 *)iov->iov_base - 1;
1442         if (len < 0)
1443                 goto out_overflow;
1444         switch ((n = ntohl(*p++))) {
1445         case RPC_SUCCESS:
1446                 return p;
1447         case RPC_PROG_UNAVAIL:
1448                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1449                                 task->tk_pid, __FUNCTION__,
1450                                 (unsigned int)task->tk_client->cl_prog,
1451                                 task->tk_client->cl_server);
1452                 error = -EPFNOSUPPORT;
1453                 goto out_err;
1454         case RPC_PROG_MISMATCH:
1455                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1456                                 "server %s\n", task->tk_pid, __FUNCTION__,
1457                                 (unsigned int)task->tk_client->cl_prog,
1458                                 (unsigned int)task->tk_client->cl_vers,
1459                                 task->tk_client->cl_server);
1460                 error = -EPROTONOSUPPORT;
1461                 goto out_err;
1462         case RPC_PROC_UNAVAIL:
1463                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1464                                 "version %u on server %s\n",
1465                                 task->tk_pid, __FUNCTION__,
1466                                 task->tk_msg.rpc_proc,
1467                                 task->tk_client->cl_prog,
1468                                 task->tk_client->cl_vers,
1469                                 task->tk_client->cl_server);
1470                 error = -EOPNOTSUPP;
1471                 goto out_err;
1472         case RPC_GARBAGE_ARGS:
1473                 dprintk("RPC: %5u %s: server saw garbage\n",
1474                                 task->tk_pid, __FUNCTION__);
1475                 break;                  /* retry */
1476         default:
1477                 dprintk("RPC: %5u %s: server accept status: %x\n",
1478                                 task->tk_pid, __FUNCTION__, n);
1479                 /* Also retry */
1480         }
1481
1482 out_garbage:
1483         task->tk_client->cl_stats->rpcgarbage++;
1484         if (task->tk_garb_retry) {
1485                 task->tk_garb_retry--;
1486                 dprintk("RPC: %5u %s: retrying\n",
1487                                 task->tk_pid, __FUNCTION__);
1488                 task->tk_action = call_bind;
1489 out_retry:
1490                 return ERR_PTR(-EAGAIN);
1491         }
1492 out_eio:
1493         error = -EIO;
1494 out_err:
1495         rpc_exit(task, error);
1496         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1497                         __FUNCTION__, error);
1498         return ERR_PTR(error);
1499 out_overflow:
1500         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1501                         __FUNCTION__);
1502         goto out_garbage;
1503 }
1504
1505 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1506 {
1507         return 0;
1508 }
1509
1510 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1511 {
1512         return 0;
1513 }
1514
1515 static struct rpc_procinfo rpcproc_null = {
1516         .p_encode = rpcproc_encode_null,
1517         .p_decode = rpcproc_decode_null,
1518 };
1519
1520 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1521 {
1522         struct rpc_message msg = {
1523                 .rpc_proc = &rpcproc_null,
1524         };
1525         int err;
1526         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1527         err = rpc_call_sync(clnt, &msg, flags);
1528         put_rpccred(msg.rpc_cred);
1529         return err;
1530 }
1531
1532 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1533 {
1534         struct rpc_message msg = {
1535                 .rpc_proc = &rpcproc_null,
1536                 .rpc_cred = cred,
1537         };
1538         struct rpc_task_setup task_setup_data = {
1539                 .rpc_client = clnt,
1540                 .rpc_message = &msg,
1541                 .callback_ops = &rpc_default_ops,
1542                 .flags = flags,
1543         };
1544         return rpc_run_task(&task_setup_data);
1545 }
1546 EXPORT_SYMBOL_GPL(rpc_call_null);
1547
1548 #ifdef RPC_DEBUG
1549 void rpc_show_tasks(void)
1550 {
1551         struct rpc_clnt *clnt;
1552         struct rpc_task *t;
1553
1554         spin_lock(&rpc_client_lock);
1555         if (list_empty(&all_clients))
1556                 goto out;
1557         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1558                 "-rpcwait -action- ---ops--\n");
1559         list_for_each_entry(clnt, &all_clients, cl_clients) {
1560                 if (list_empty(&clnt->cl_tasks))
1561                         continue;
1562                 spin_lock(&clnt->cl_lock);
1563                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1564                         const char *rpc_waitq = "none";
1565                         int proc;
1566
1567                         if (t->tk_msg.rpc_proc)
1568                                 proc = t->tk_msg.rpc_proc->p_proc;
1569                         else
1570                                 proc = -1;
1571
1572                         if (RPC_IS_QUEUED(t))
1573                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1574
1575                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1576                                 t->tk_pid, proc,
1577                                 t->tk_flags, t->tk_status,
1578                                 t->tk_client,
1579                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1580                                 t->tk_rqstp, t->tk_timeout,
1581                                 rpc_waitq,
1582                                 t->tk_action, t->tk_ops);
1583                 }
1584                 spin_unlock(&clnt->cl_lock);
1585         }
1586 out:
1587         spin_unlock(&rpc_client_lock);
1588 }
1589 #endif