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
  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  */
  50 static LIST_HEAD(all_clients);
  51 static DEFINE_SPINLOCK(rpc_client_lock);
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  54
  55
  56 static void     call_start(struct rpc_task *task);
  57 static void     call_reserve(struct rpc_task *task);
  58 static void     call_reserveresult(struct rpc_task *task);
  59 static void     call_allocate(struct rpc_task *task);
  60 static void     call_encode(struct rpc_task *task);
  61 static void     call_decode(struct rpc_task *task);
  62 static void     call_bind(struct rpc_task *task);
  63 static void     call_bind_status(struct rpc_task *task);
  64 static void     call_transmit(struct rpc_task *task);
  65 static void     call_status(struct rpc_task *task);
  66 static void     call_transmit_status(struct rpc_task *task);
  67 static void     call_refresh(struct rpc_task *task);
  68 static void     call_refreshresult(struct rpc_task *task);
  69 static void     call_timeout(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72 static __be32 * call_header(struct rpc_task *task);
  73 static __be32 * call_verify(struct rpc_task *task);
  74
  75 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  76
  77 static 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
  84 static 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
  91 static int
  92 rpc_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
 124 static 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
 210 out_no_auth:
 211         if (!IS_ERR(clnt->cl_dentry)) {
 212                 rpc_rmdir(clnt->cl_dentry);
 213                 rpc_put_mount();
 214         }
 215 out_no_path:
 216         rpc_free_iostats(clnt->cl_metrics);
 217 out_no_stats:
 218         if (clnt->cl_server != clnt->cl_inline_name)
 219                 kfree(clnt->cl_server);
 220         kfree(clnt);
 221 out_err:
 222         xprt_put(xprt);
 223 out_no_xprt:
 224         rpciod_down();
 225 out_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  */
 239 struct 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 }
 304 EXPORT_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  */
 311 struct rpc_clnt *
 312 rpc_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;
 340 out_no_path:
 341         rpc_free_iostats(new->cl_metrics);
 342 out_no_stats:
 343         kfree(new);
 344 out_no_clnt:
 345         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 346         return ERR_PTR(err);
 347 }
 348 EXPORT_SYMBOL_GPL(rpc_clone_client);
 349
 350 /*
 351  * Properly shut down an RPC client, terminating all outstanding
 352  * requests.
 353  */
 354 void 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 }
 367 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 368
 369 /*
 370  * Free an RPC client
 371  */
 372 static void
 373 rpc_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);
 389 out_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  */
 401 static void
 402 rpc_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  */
 425 void
 426 rpc_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  */
 445 struct 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         }
 469 out:
 470         return clnt;
 471 }
 472 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 473
 474 /*
 475  * Default callback for async RPC calls
 476  */
 477 static void
 478 rpc_default_callback(struct rpc_task *task, void *data)
 479 {
 480 }
 481
 482 static 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
 492 static 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
 504 static void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 505 {
 506         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 507 }
 508
 509 static void rpc_restore_sigmask(sigset_t *oldset)
 510 {
 511         sigprocmask(SIG_SETMASK, oldset, NULL);
 512 }
 513
 514 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 515 {
 516         rpc_save_sigmask(oldset, clnt->cl_intr);
 517 }
 518 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 519
 520 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 521 {
 522         rpc_restore_sigmask(oldset);
 523 }
 524 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 525
 526 /**
 527  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 528  * @task_setup_data: pointer to task initialisation data
 529  */
 530 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 531 {
 532         struct rpc_task *task, *ret;
 533         sigset_t oldset;
 534
 535         task = rpc_new_task(task_setup_data);
 536         if (task == NULL) {
 537                 rpc_release_calldata(task_setup_data->callback_ops,
 538                                 task_setup_data->callback_data);
 539                 ret = ERR_PTR(-ENOMEM);
 540                 goto out;
 541         }
 542
 543         if (task->tk_status != 0) {
 544                 ret = ERR_PTR(task->tk_status);
 545                 rpc_put_task(task);
 546                 goto out;
 547         }
 548         atomic_inc(&task->tk_count);
 549         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 550         rpc_task_sigmask(task, &oldset);
 551         rpc_execute(task);
 552         rpc_restore_sigmask(&oldset);
 553         ret = task;
 554 out:
 555         return ret;
 556 }
 557 EXPORT_SYMBOL_GPL(rpc_run_task);
 558
 559 /**
 560  * rpc_call_sync - Perform a synchronous RPC call
 561  * @clnt: pointer to RPC client
 562  * @msg: RPC call parameters
 563  * @flags: RPC call flags
 564  */
 565 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 566 {
 567         struct rpc_task *task;
 568         struct rpc_task_setup task_setup_data = {
 569                 .rpc_client = clnt,
 570                 .rpc_message = msg,
 571                 .callback_ops = &rpc_default_ops,
 572                 .flags = flags,
 573         };
 574         int status;
 575
 576         BUG_ON(flags & RPC_TASK_ASYNC);
 577
 578         task = rpc_run_task(&task_setup_data);
 579         if (IS_ERR(task))
 580                 return PTR_ERR(task);
 581         status = task->tk_status;
 582         rpc_put_task(task);
 583         return status;
 584 }
 585 EXPORT_SYMBOL_GPL(rpc_call_sync);
 586
 587 /**
 588  * rpc_call_async - Perform an asynchronous RPC call
 589  * @clnt: pointer to RPC client
 590  * @msg: RPC call parameters
 591  * @flags: RPC call flags
 592  * @ops: RPC call ops
 593  * @data: user call data
 594  */
 595 int
 596 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 597                const struct rpc_call_ops *tk_ops, void *data)
 598 {
 599         struct rpc_task *task;
 600         struct rpc_task_setup task_setup_data = {
 601                 .rpc_client = clnt,
 602                 .rpc_message = msg,
 603                 .callback_ops = tk_ops,
 604                 .callback_data = data,
 605                 .flags = flags|RPC_TASK_ASYNC,
 606         };
 607
 608         task = rpc_run_task(&task_setup_data);
 609         if (IS_ERR(task))
 610                 return PTR_ERR(task);
 611         rpc_put_task(task);
 612         return 0;
 613 }
 614 EXPORT_SYMBOL_GPL(rpc_call_async);
 615
 616 void
 617 rpc_call_setup(struct rpc_task *task, const struct rpc_message *msg, int flags)
 618 {
 619         task->tk_msg   = *msg;
 620         task->tk_flags |= flags;
 621         /* Bind the user cred */
 622         if (task->tk_msg.rpc_cred != NULL)
 623                 rpcauth_holdcred(task);
 624         else
 625                 rpcauth_bindcred(task);
 626
 627         if (task->tk_status == 0)
 628                 task->tk_action = call_start;
 629         else
 630                 task->tk_action = rpc_exit_task;
 631 }
 632 EXPORT_SYMBOL_GPL(rpc_call_setup);
 633
 634 void
 635 rpc_call_start(struct rpc_task *task)
 636 {
 637         task->tk_action = call_start;
 638 }
 639 EXPORT_SYMBOL_GPL(rpc_call_start);
 640
 641 /**
 642  * rpc_peeraddr - extract remote peer address from clnt's xprt
 643  * @clnt: RPC client structure
 644  * @buf: target buffer
 645  * @size: length of target buffer
 646  *
 647  * Returns the number of bytes that are actually in the stored address.
 648  */
 649 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 650 {
 651         size_t bytes;
 652         struct rpc_xprt *xprt = clnt->cl_xprt;
 653
 654         bytes = sizeof(xprt->addr);
 655         if (bytes > bufsize)
 656                 bytes = bufsize;
 657         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 658         return xprt->addrlen;
 659 }
 660 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 661
 662 /**
 663  * rpc_peeraddr2str - return remote peer address in printable format
 664  * @clnt: RPC client structure
 665  * @format: address format
 666  *
 667  */
 668 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 669 {
 670         struct rpc_xprt *xprt = clnt->cl_xprt;
 671
 672         if (xprt->address_strings[format] != NULL)
 673                 return xprt->address_strings[format];
 674         else
 675                 return "unprintable";
 676 }
 677 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 678
 679 void
 680 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 681 {
 682         struct rpc_xprt *xprt = clnt->cl_xprt;
 683         if (xprt->ops->set_buffer_size)
 684                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 685 }
 686 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 687
 688 /*
 689  * Return size of largest payload RPC client can support, in bytes
 690  *
 691  * For stream transports, this is one RPC record fragment (see RFC
 692  * 1831), as we don't support multi-record requests yet.  For datagram
 693  * transports, this is the size of an IP packet minus the IP, UDP, and
 694  * RPC header sizes.
 695  */
 696 size_t rpc_max_payload(struct rpc_clnt *clnt)
 697 {
 698         return clnt->cl_xprt->max_payload;
 699 }
 700 EXPORT_SYMBOL_GPL(rpc_max_payload);
 701
 702 /**
 703  * rpc_force_rebind - force transport to check that remote port is unchanged
 704  * @clnt: client to rebind
 705  *
 706  */
 707 void rpc_force_rebind(struct rpc_clnt *clnt)
 708 {
 709         if (clnt->cl_autobind)
 710                 xprt_clear_bound(clnt->cl_xprt);
 711 }
 712 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 713
 714 /*
 715  * Restart an (async) RPC call. Usually called from within the
 716  * exit handler.
 717  */
 718 void
 719 rpc_restart_call(struct rpc_task *task)
 720 {
 721         if (RPC_ASSASSINATED(task))
 722                 return;
 723
 724         task->tk_action = call_start;
 725 }
 726 EXPORT_SYMBOL_GPL(rpc_restart_call);
 727
 728 /*
 729  * 0.  Initial state
 730  *
 731  *     Other FSM states can be visited zero or more times, but
 732  *     this state is visited exactly once for each RPC.
 733  */
 734 static void
 735 call_start(struct rpc_task *task)
 736 {
 737         struct rpc_clnt *clnt = task->tk_client;
 738
 739         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 740                         clnt->cl_protname, clnt->cl_vers,
 741                         task->tk_msg.rpc_proc->p_proc,
 742                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 743
 744         /* Increment call count */
 745         task->tk_msg.rpc_proc->p_count++;
 746         clnt->cl_stats->rpccnt++;
 747         task->tk_action = call_reserve;
 748 }
 749
 750 /*
 751  * 1.   Reserve an RPC call slot
 752  */
 753 static void
 754 call_reserve(struct rpc_task *task)
 755 {
 756         dprint_status(task);
 757
 758         if (!rpcauth_uptodatecred(task)) {
 759                 task->tk_action = call_refresh;
 760                 return;
 761         }
 762
 763         task->tk_status  = 0;
 764         task->tk_action  = call_reserveresult;
 765         xprt_reserve(task);
 766 }
 767
 768 /*
 769  * 1b.  Grok the result of xprt_reserve()
 770  */
 771 static void
 772 call_reserveresult(struct rpc_task *task)
 773 {
 774         int status = task->tk_status;
 775
 776         dprint_status(task);
 777
 778         /*
 779          * After a call to xprt_reserve(), we must have either
 780          * a request slot or else an error status.
 781          */
 782         task->tk_status = 0;
 783         if (status >= 0) {
 784                 if (task->tk_rqstp) {
 785                         task->tk_action = call_allocate;
 786                         return;
 787                 }
 788
 789                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 790                                 __FUNCTION__, status);
 791                 rpc_exit(task, -EIO);
 792                 return;
 793         }
 794
 795         /*
 796          * Even though there was an error, we may have acquired
 797          * a request slot somehow.  Make sure not to leak it.
 798          */
 799         if (task->tk_rqstp) {
 800                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 801                                 __FUNCTION__, status);
 802                 xprt_release(task);
 803         }
 804
 805         switch (status) {
 806         case -EAGAIN:   /* woken up; retry */
 807                 task->tk_action = call_reserve;
 808                 return;
 809         case -EIO:      /* probably a shutdown */
 810                 break;
 811         default:
 812                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 813                                 __FUNCTION__, status);
 814                 break;
 815         }
 816         rpc_exit(task, status);
 817 }
 818
 819 /*
 820  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 821  *      (Note: buffer memory is freed in xprt_release).
 822  */
 823 static void
 824 call_allocate(struct rpc_task *task)
 825 {
 826         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 827         struct rpc_rqst *req = task->tk_rqstp;
 828         struct rpc_xprt *xprt = task->tk_xprt;
 829         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 830
 831         dprint_status(task);
 832
 833         task->tk_status = 0;
 834         task->tk_action = call_bind;
 835
 836         if (req->rq_buffer)
 837                 return;
 838
 839         if (proc->p_proc != 0) {
 840                 BUG_ON(proc->p_arglen == 0);
 841                 if (proc->p_decode != NULL)
 842                         BUG_ON(proc->p_replen == 0);
 843         }
 844
 845         /*
 846          * Calculate the size (in quads) of the RPC call
 847          * and reply headers, and convert both values
 848          * to byte sizes.
 849          */
 850         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 851         req->rq_callsize <<= 2;
 852         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 853         req->rq_rcvsize <<= 2;
 854
 855         req->rq_buffer = xprt->ops->buf_alloc(task,
 856                                         req->rq_callsize + req->rq_rcvsize);
 857         if (req->rq_buffer != NULL)
 858                 return;
 859
 860         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 861
 862         if (RPC_IS_ASYNC(task) || !signalled()) {
 863                 task->tk_action = call_allocate;
 864                 rpc_delay(task, HZ>>4);
 865                 return;
 866         }
 867
 868         rpc_exit(task, -ERESTARTSYS);
 869 }
 870
 871 static inline int
 872 rpc_task_need_encode(struct rpc_task *task)
 873 {
 874         return task->tk_rqstp->rq_snd_buf.len == 0;
 875 }
 876
 877 static inline void
 878 rpc_task_force_reencode(struct rpc_task *task)
 879 {
 880         task->tk_rqstp->rq_snd_buf.len = 0;
 881 }
 882
 883 static inline void
 884 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 885 {
 886         buf->head[0].iov_base = start;
 887         buf->head[0].iov_len = len;
 888         buf->tail[0].iov_len = 0;
 889         buf->page_len = 0;
 890         buf->flags = 0;
 891         buf->len = 0;
 892         buf->buflen = len;
 893 }
 894
 895 /*
 896  * 3.   Encode arguments of an RPC call
 897  */
 898 static void
 899 call_encode(struct rpc_task *task)
 900 {
 901         struct rpc_rqst *req = task->tk_rqstp;
 902         kxdrproc_t      encode;
 903         __be32          *p;
 904
 905         dprint_status(task);
 906
 907         rpc_xdr_buf_init(&req->rq_snd_buf,
 908                          req->rq_buffer,
 909                          req->rq_callsize);
 910         rpc_xdr_buf_init(&req->rq_rcv_buf,
 911                          (char *)req->rq_buffer + req->rq_callsize,
 912                          req->rq_rcvsize);
 913
 914         /* Encode header and provided arguments */
 915         encode = task->tk_msg.rpc_proc->p_encode;
 916         if (!(p = call_header(task))) {
 917                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 918                 rpc_exit(task, -EIO);
 919                 return;
 920         }
 921         if (encode == NULL)
 922                 return;
 923
 924         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 925                         task->tk_msg.rpc_argp);
 926         if (task->tk_status == -ENOMEM) {
 927                 /* XXX: Is this sane? */
 928                 rpc_delay(task, 3*HZ);
 929                 task->tk_status = -EAGAIN;
 930         }
 931 }
 932
 933 /*
 934  * 4.   Get the server port number if not yet set
 935  */
 936 static void
 937 call_bind(struct rpc_task *task)
 938 {
 939         struct rpc_xprt *xprt = task->tk_xprt;
 940
 941         dprint_status(task);
 942
 943         task->tk_action = call_connect;
 944         if (!xprt_bound(xprt)) {
 945                 task->tk_action = call_bind_status;
 946                 task->tk_timeout = xprt->bind_timeout;
 947                 xprt->ops->rpcbind(task);
 948         }
 949 }
 950
 951 /*
 952  * 4a.  Sort out bind result
 953  */
 954 static void
 955 call_bind_status(struct rpc_task *task)
 956 {
 957         int status = -EIO;
 958
 959         if (task->tk_status >= 0) {
 960                 dprint_status(task);
 961                 task->tk_status = 0;
 962                 task->tk_action = call_connect;
 963                 return;
 964         }
 965
 966         switch (task->tk_status) {
 967         case -EAGAIN:
 968                 dprintk("RPC: %5u rpcbind waiting for another request "
 969                                 "to finish\n", task->tk_pid);
 970                 /* avoid busy-waiting here -- could be a network outage. */
 971                 rpc_delay(task, 5*HZ);
 972                 goto retry_timeout;
 973         case -EACCES:
 974                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 975                                 "unavailable\n", task->tk_pid);
 976                 /* fail immediately if this is an RPC ping */
 977                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 978                         status = -EOPNOTSUPP;
 979                         break;
 980                 }
 981                 rpc_delay(task, 3*HZ);
 982                 goto retry_timeout;
 983         case -ETIMEDOUT:
 984                 dprintk("RPC: %5u rpcbind request timed out\n",
 985                                 task->tk_pid);
 986                 goto retry_timeout;
 987         case -EPFNOSUPPORT:
 988                 /* server doesn't support any rpcbind version we know of */
 989                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 990                                 task->tk_pid);
 991                 break;
 992         case -EPROTONOSUPPORT:
 993                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 994                                 task->tk_pid);
 995                 task->tk_status = 0;
 996                 task->tk_action = call_bind;
 997                 return;
 998         default:
 999                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1000                                 task->tk_pid, -task->tk_status);
1001         }
1002
1003         rpc_exit(task, status);
1004         return;
1005
1006 retry_timeout:
1007         task->tk_action = call_timeout;
1008 }
1009
1010 /*
1011  * 4b.  Connect to the RPC server
1012  */
1013 static void
1014 call_connect(struct rpc_task *task)
1015 {
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017
1018         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1019                         task->tk_pid, xprt,
1020                         (xprt_connected(xprt) ? "is" : "is not"));
1021
1022         task->tk_action = call_transmit;
1023         if (!xprt_connected(xprt)) {
1024                 task->tk_action = call_connect_status;
1025                 if (task->tk_status < 0)
1026                         return;
1027                 xprt_connect(task);
1028         }
1029 }
1030
1031 /*
1032  * 4c.  Sort out connect result
1033  */
1034 static void
1035 call_connect_status(struct rpc_task *task)
1036 {
1037         struct rpc_clnt *clnt = task->tk_client;
1038         int status = task->tk_status;
1039
1040         dprint_status(task);
1041
1042         task->tk_status = 0;
1043         if (status >= 0) {
1044                 clnt->cl_stats->netreconn++;
1045                 task->tk_action = call_transmit;
1046                 return;
1047         }
1048
1049         /* Something failed: remote service port may have changed */
1050         rpc_force_rebind(clnt);
1051
1052         switch (status) {
1053         case -ENOTCONN:
1054         case -EAGAIN:
1055                 task->tk_action = call_bind;
1056                 if (!RPC_IS_SOFT(task))
1057                         return;
1058                 /* if soft mounted, test if we've timed out */
1059         case -ETIMEDOUT:
1060                 task->tk_action = call_timeout;
1061                 return;
1062         }
1063         rpc_exit(task, -EIO);
1064 }
1065
1066 /*
1067  * 5.   Transmit the RPC request, and wait for reply
1068  */
1069 static void
1070 call_transmit(struct rpc_task *task)
1071 {
1072         dprint_status(task);
1073
1074         task->tk_action = call_status;
1075         if (task->tk_status < 0)
1076                 return;
1077         task->tk_status = xprt_prepare_transmit(task);
1078         if (task->tk_status != 0)
1079                 return;
1080         task->tk_action = call_transmit_status;
1081         /* Encode here so that rpcsec_gss can use correct sequence number. */
1082         if (rpc_task_need_encode(task)) {
1083                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1084                 call_encode(task);
1085                 /* Did the encode result in an error condition? */
1086                 if (task->tk_status != 0)
1087                         return;
1088         }
1089         xprt_transmit(task);
1090         if (task->tk_status < 0)
1091                 return;
1092         /*
1093          * On success, ensure that we call xprt_end_transmit() before sleeping
1094          * in order to allow access to the socket to other RPC requests.
1095          */
1096         call_transmit_status(task);
1097         if (task->tk_msg.rpc_proc->p_decode != NULL)
1098                 return;
1099         task->tk_action = rpc_exit_task;
1100         rpc_wake_up_task(task);
1101 }
1102
1103 /*
1104  * 5a.  Handle cleanup after a transmission
1105  */
1106 static void
1107 call_transmit_status(struct rpc_task *task)
1108 {
1109         task->tk_action = call_status;
1110         /*
1111          * Special case: if we've been waiting on the socket's write_space()
1112          * callback, then don't call xprt_end_transmit().
1113          */
1114         if (task->tk_status == -EAGAIN)
1115                 return;
1116         xprt_end_transmit(task);
1117         rpc_task_force_reencode(task);
1118 }
1119
1120 /*
1121  * 6.   Sort out the RPC call status
1122  */
1123 static void
1124 call_status(struct rpc_task *task)
1125 {
1126         struct rpc_clnt *clnt = task->tk_client;
1127         struct rpc_rqst *req = task->tk_rqstp;
1128         int             status;
1129
1130         if (req->rq_received > 0 && !req->rq_bytes_sent)
1131                 task->tk_status = req->rq_received;
1132
1133         dprint_status(task);
1134
1135         status = task->tk_status;
1136         if (status >= 0) {
1137                 task->tk_action = call_decode;
1138                 return;
1139         }
1140
1141         task->tk_status = 0;
1142         switch(status) {
1143         case -EHOSTDOWN:
1144         case -EHOSTUNREACH:
1145         case -ENETUNREACH:
1146                 /*
1147                  * Delay any retries for 3 seconds, then handle as if it
1148                  * were a timeout.
1149                  */
1150                 rpc_delay(task, 3*HZ);
1151         case -ETIMEDOUT:
1152                 task->tk_action = call_timeout;
1153                 if (task->tk_client->cl_discrtry)
1154                         xprt_force_disconnect(task->tk_xprt);
1155                 break;
1156         case -ECONNREFUSED:
1157         case -ENOTCONN:
1158                 rpc_force_rebind(clnt);
1159                 task->tk_action = call_bind;
1160                 break;
1161         case -EAGAIN:
1162                 task->tk_action = call_transmit;
1163                 break;
1164         case -EIO:
1165                 /* shutdown or soft timeout */
1166                 rpc_exit(task, status);
1167                 break;
1168         default:
1169                 printk("%s: RPC call returned error %d\n",
1170                                clnt->cl_protname, -status);
1171                 rpc_exit(task, status);
1172         }
1173 }
1174
1175 /*
1176  * 6a.  Handle RPC timeout
1177  *      We do not release the request slot, so we keep using the
1178  *      same XID for all retransmits.
1179  */
1180 static void
1181 call_timeout(struct rpc_task *task)
1182 {
1183         struct rpc_clnt *clnt = task->tk_client;
1184
1185         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1186                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1187                 goto retry;
1188         }
1189
1190         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1191         task->tk_timeouts++;
1192
1193         if (RPC_IS_SOFT(task)) {
1194                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1195                                 clnt->cl_protname, clnt->cl_server);
1196                 rpc_exit(task, -EIO);
1197                 return;
1198         }
1199
1200         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1201                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1202                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1203                         clnt->cl_protname, clnt->cl_server);
1204         }
1205         rpc_force_rebind(clnt);
1206
1207 retry:
1208         clnt->cl_stats->rpcretrans++;
1209         task->tk_action = call_bind;
1210         task->tk_status = 0;
1211 }
1212
1213 /*
1214  * 7.   Decode the RPC reply
1215  */
1216 static void
1217 call_decode(struct rpc_task *task)
1218 {
1219         struct rpc_clnt *clnt = task->tk_client;
1220         struct rpc_rqst *req = task->tk_rqstp;
1221         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1222         __be32          *p;
1223
1224         dprintk("RPC: %5u call_decode (status %d)\n",
1225                         task->tk_pid, task->tk_status);
1226
1227         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1228                 printk(KERN_NOTICE "%s: server %s OK\n",
1229                         clnt->cl_protname, clnt->cl_server);
1230                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1231         }
1232
1233         if (task->tk_status < 12) {
1234                 if (!RPC_IS_SOFT(task)) {
1235                         task->tk_action = call_bind;
1236                         clnt->cl_stats->rpcretrans++;
1237                         goto out_retry;
1238                 }
1239                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1240                                 clnt->cl_protname, task->tk_status);
1241                 task->tk_action = call_timeout;
1242                 goto out_retry;
1243         }
1244
1245         /*
1246          * Ensure that we see all writes made by xprt_complete_rqst()
1247          * before it changed req->rq_received.
1248          */
1249         smp_rmb();
1250         req->rq_rcv_buf.len = req->rq_private_buf.len;
1251
1252         /* Check that the softirq receive buffer is valid */
1253         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1254                                 sizeof(req->rq_rcv_buf)) != 0);
1255
1256         /* Verify the RPC header */
1257         p = call_verify(task);
1258         if (IS_ERR(p)) {
1259                 if (p == ERR_PTR(-EAGAIN))
1260                         goto out_retry;
1261                 return;
1262         }
1263
1264         task->tk_action = rpc_exit_task;
1265
1266         if (decode) {
1267                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1268                                                       task->tk_msg.rpc_resp);
1269         }
1270         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1271                         task->tk_status);
1272         return;
1273 out_retry:
1274         req->rq_received = req->rq_private_buf.len = 0;
1275         task->tk_status = 0;
1276         if (task->tk_client->cl_discrtry)
1277                 xprt_force_disconnect(task->tk_xprt);
1278 }
1279
1280 /*
1281  * 8.   Refresh the credentials if rejected by the server
1282  */
1283 static void
1284 call_refresh(struct rpc_task *task)
1285 {
1286         dprint_status(task);
1287
1288         task->tk_action = call_refreshresult;
1289         task->tk_status = 0;
1290         task->tk_client->cl_stats->rpcauthrefresh++;
1291         rpcauth_refreshcred(task);
1292 }
1293
1294 /*
1295  * 8a.  Process the results of a credential refresh
1296  */
1297 static void
1298 call_refreshresult(struct rpc_task *task)
1299 {
1300         int status = task->tk_status;
1301
1302         dprint_status(task);
1303
1304         task->tk_status = 0;
1305         task->tk_action = call_reserve;
1306         if (status >= 0 && rpcauth_uptodatecred(task))
1307                 return;
1308         if (status == -EACCES) {
1309                 rpc_exit(task, -EACCES);
1310                 return;
1311         }
1312         task->tk_action = call_refresh;
1313         if (status != -ETIMEDOUT)
1314                 rpc_delay(task, 3*HZ);
1315         return;
1316 }
1317
1318 /*
1319  * Call header serialization
1320  */
1321 static __be32 *
1322 call_header(struct rpc_task *task)
1323 {
1324         struct rpc_clnt *clnt = task->tk_client;
1325         struct rpc_rqst *req = task->tk_rqstp;
1326         __be32          *p = req->rq_svec[0].iov_base;
1327
1328         /* FIXME: check buffer size? */
1329
1330         p = xprt_skip_transport_header(task->tk_xprt, p);
1331         *p++ = req->rq_xid;             /* XID */
1332         *p++ = htonl(RPC_CALL);         /* CALL */
1333         *p++ = htonl(RPC_VERSION);      /* RPC version */
1334         *p++ = htonl(clnt->cl_prog);    /* program number */
1335         *p++ = htonl(clnt->cl_vers);    /* program version */
1336         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1337         p = rpcauth_marshcred(task, p);
1338         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1339         return p;
1340 }
1341
1342 /*
1343  * Reply header verification
1344  */
1345 static __be32 *
1346 call_verify(struct rpc_task *task)
1347 {
1348         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1349         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1350         __be32  *p = iov->iov_base;
1351         u32 n;
1352         int error = -EACCES;
1353
1354         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1355                 /* RFC-1014 says that the representation of XDR data must be a
1356                  * multiple of four bytes
1357                  * - if it isn't pointer subtraction in the NFS client may give
1358                  *   undefined results
1359                  */
1360                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1361                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1362                        task->tk_rqstp->rq_rcv_buf.len);
1363                 goto out_eio;
1364         }
1365         if ((len -= 3) < 0)
1366                 goto out_overflow;
1367         p += 1; /* skip XID */
1368
1369         if ((n = ntohl(*p++)) != RPC_REPLY) {
1370                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1371                                 task->tk_pid, __FUNCTION__, n);
1372                 goto out_garbage;
1373         }
1374         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1375                 if (--len < 0)
1376                         goto out_overflow;
1377                 switch ((n = ntohl(*p++))) {
1378                         case RPC_AUTH_ERROR:
1379                                 break;
1380                         case RPC_MISMATCH:
1381                                 dprintk("RPC: %5u %s: RPC call version "
1382                                                 "mismatch!\n",
1383                                                 task->tk_pid, __FUNCTION__);
1384                                 error = -EPROTONOSUPPORT;
1385                                 goto out_err;
1386                         default:
1387                                 dprintk("RPC: %5u %s: RPC call rejected, "
1388                                                 "unknown error: %x\n",
1389                                                 task->tk_pid, __FUNCTION__, n);
1390                                 goto out_eio;
1391                 }
1392                 if (--len < 0)
1393                         goto out_overflow;
1394                 switch ((n = ntohl(*p++))) {
1395                 case RPC_AUTH_REJECTEDCRED:
1396                 case RPC_AUTH_REJECTEDVERF:
1397                 case RPCSEC_GSS_CREDPROBLEM:
1398                 case RPCSEC_GSS_CTXPROBLEM:
1399                         if (!task->tk_cred_retry)
1400                                 break;
1401                         task->tk_cred_retry--;
1402                         dprintk("RPC: %5u %s: retry stale creds\n",
1403                                         task->tk_pid, __FUNCTION__);
1404                         rpcauth_invalcred(task);
1405                         /* Ensure we obtain a new XID! */
1406                         xprt_release(task);
1407                         task->tk_action = call_refresh;
1408                         goto out_retry;
1409                 case RPC_AUTH_BADCRED:
1410                 case RPC_AUTH_BADVERF:
1411                         /* possibly garbled cred/verf? */
1412                         if (!task->tk_garb_retry)
1413                                 break;
1414                         task->tk_garb_retry--;
1415                         dprintk("RPC: %5u %s: retry garbled creds\n",
1416                                         task->tk_pid, __FUNCTION__);
1417                         task->tk_action = call_bind;
1418                         goto out_retry;
1419                 case RPC_AUTH_TOOWEAK:
1420                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1421                                "authentication.\n", task->tk_client->cl_server);
1422                         break;
1423                 default:
1424                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1425                                         task->tk_pid, __FUNCTION__, n);
1426                         error = -EIO;
1427                 }
1428                 dprintk("RPC: %5u %s: call rejected %d\n",
1429                                 task->tk_pid, __FUNCTION__, n);
1430                 goto out_err;
1431         }
1432         if (!(p = rpcauth_checkverf(task, p))) {
1433                 dprintk("RPC: %5u %s: auth check failed\n",
1434                                 task->tk_pid, __FUNCTION__);
1435                 goto out_garbage;               /* bad verifier, retry */
1436         }
1437         len = p - (__be32 *)iov->iov_base - 1;
1438         if (len < 0)
1439                 goto out_overflow;
1440         switch ((n = ntohl(*p++))) {
1441         case RPC_SUCCESS:
1442                 return p;
1443         case RPC_PROG_UNAVAIL:
1444                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1445                                 task->tk_pid, __FUNCTION__,
1446                                 (unsigned int)task->tk_client->cl_prog,
1447                                 task->tk_client->cl_server);
1448                 error = -EPFNOSUPPORT;
1449                 goto out_err;
1450         case RPC_PROG_MISMATCH:
1451                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1452                                 "server %s\n", task->tk_pid, __FUNCTION__,
1453                                 (unsigned int)task->tk_client->cl_prog,
1454                                 (unsigned int)task->tk_client->cl_vers,
1455                                 task->tk_client->cl_server);
1456                 error = -EPROTONOSUPPORT;
1457                 goto out_err;
1458         case RPC_PROC_UNAVAIL:
1459                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1460                                 "version %u on server %s\n",
1461                                 task->tk_pid, __FUNCTION__,
1462                                 task->tk_msg.rpc_proc,
1463                                 task->tk_client->cl_prog,
1464                                 task->tk_client->cl_vers,
1465                                 task->tk_client->cl_server);
1466                 error = -EOPNOTSUPP;
1467                 goto out_err;
1468         case RPC_GARBAGE_ARGS:
1469                 dprintk("RPC: %5u %s: server saw garbage\n",
1470                                 task->tk_pid, __FUNCTION__);
1471                 break;                  /* retry */
1472         default:
1473                 dprintk("RPC: %5u %s: server accept status: %x\n",
1474                                 task->tk_pid, __FUNCTION__, n);
1475                 /* Also retry */
1476         }
1477
1478 out_garbage:
1479         task->tk_client->cl_stats->rpcgarbage++;
1480         if (task->tk_garb_retry) {
1481                 task->tk_garb_retry--;
1482                 dprintk("RPC: %5u %s: retrying\n",
1483                                 task->tk_pid, __FUNCTION__);
1484                 task->tk_action = call_bind;
1485 out_retry:
1486                 return ERR_PTR(-EAGAIN);
1487         }
1488 out_eio:
1489         error = -EIO;
1490 out_err:
1491         rpc_exit(task, error);
1492         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1493                         __FUNCTION__, error);
1494         return ERR_PTR(error);
1495 out_overflow:
1496         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1497                         __FUNCTION__);
1498         goto out_garbage;
1499 }
1500
1501 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1502 {
1503         return 0;
1504 }
1505
1506 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1507 {
1508         return 0;
1509 }
1510
1511 static struct rpc_procinfo rpcproc_null = {
1512         .p_encode = rpcproc_encode_null,
1513         .p_decode = rpcproc_decode_null,
1514 };
1515
1516 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1517 {
1518         struct rpc_message msg = {
1519                 .rpc_proc = &rpcproc_null,
1520         };
1521         int err;
1522         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1523         err = rpc_call_sync(clnt, &msg, flags);
1524         put_rpccred(msg.rpc_cred);
1525         return err;
1526 }
1527
1528 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1529 {
1530         struct rpc_message msg = {
1531                 .rpc_proc = &rpcproc_null,
1532                 .rpc_cred = cred,
1533         };
1534         struct rpc_task_setup task_setup_data = {
1535                 .rpc_client = clnt,
1536                 .rpc_message = &msg,
1537                 .callback_ops = &rpc_default_ops,
1538                 .flags = flags,
1539         };
1540         return rpc_run_task(&task_setup_data);
1541 }
1542 EXPORT_SYMBOL_GPL(rpc_call_null);
1543
1544 #ifdef RPC_DEBUG
1545 void rpc_show_tasks(void)
1546 {
1547         struct rpc_clnt *clnt;
1548         struct rpc_task *t;
1549
1550         spin_lock(&rpc_client_lock);
1551         if (list_empty(&all_clients))
1552                 goto out;
1553         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1554                 "-rpcwait -action- ---ops--\n");
1555         list_for_each_entry(clnt, &all_clients, cl_clients) {
1556                 if (list_empty(&clnt->cl_tasks))
1557                         continue;
1558                 spin_lock(&clnt->cl_lock);
1559                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1560                         const char *rpc_waitq = "none";
1561                         int proc;
1562
1563                         if (t->tk_msg.rpc_proc)
1564                                 proc = t->tk_msg.rpc_proc->p_proc;
1565                         else
1566                                 proc = -1;
1567
1568                         if (RPC_IS_QUEUED(t))
1569                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1570
1571                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1572                                 t->tk_pid, proc,
1573                                 t->tk_flags, t->tk_status,
1574                                 t->tk_client,
1575                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1576                                 t->tk_rqstp, t->tk_timeout,
1577                                 rpc_waitq,
1578                                 t->tk_action, t->tk_ops);
1579                 }
1580                 spin_unlock(&clnt->cl_lock);
1581         }
1582 out:
1583         spin_unlock(&rpc_client_lock);
1584 }
1585 #endif