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(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 126 {
 127         struct rpc_program      *program = args->program;
 128         struct rpc_version      *version;
 129         struct rpc_clnt         *clnt = NULL;
 130         struct rpc_auth         *auth;
 131         int err;
 132         size_t len;
 133
 134         /* sanity check the name before trying to print it */
 135         err = -EINVAL;
 136         len = strlen(args->servername);
 137         if (len > RPC_MAXNETNAMELEN)
 138                 goto out_no_rpciod;
 139         len++;
 140
 141         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 142                         program->name, args->servername, xprt);
 143
 144         err = rpciod_up();
 145         if (err)
 146                 goto out_no_rpciod;
 147         err = -EINVAL;
 148         if (!xprt)
 149                 goto out_no_xprt;
 150
 151         if (args->version >= program->nrvers)
 152                 goto out_err;
 153         version = program->version[args->version];
 154         if (version == NULL)
 155                 goto out_err;
 156
 157         err = -ENOMEM;
 158         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 159         if (!clnt)
 160                 goto out_err;
 161         clnt->cl_parent = clnt;
 162
 163         clnt->cl_server = clnt->cl_inline_name;
 164         if (len > sizeof(clnt->cl_inline_name)) {
 165                 char *buf = kmalloc(len, GFP_KERNEL);
 166                 if (buf != NULL)
 167                         clnt->cl_server = buf;
 168                 else
 169                         len = sizeof(clnt->cl_inline_name);
 170         }
 171         strlcpy(clnt->cl_server, args->servername, len);
 172
 173         clnt->cl_xprt     = xprt;
 174         clnt->cl_procinfo = version->procs;
 175         clnt->cl_maxproc  = version->nrprocs;
 176         clnt->cl_protname = program->name;
 177         clnt->cl_prog     = program->number;
 178         clnt->cl_vers     = version->number;
 179         clnt->cl_stats    = program->stats;
 180         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 181         err = -ENOMEM;
 182         if (clnt->cl_metrics == NULL)
 183                 goto out_no_stats;
 184         clnt->cl_program  = program;
 185         INIT_LIST_HEAD(&clnt->cl_tasks);
 186         spin_lock_init(&clnt->cl_lock);
 187
 188         if (!xprt_bound(clnt->cl_xprt))
 189                 clnt->cl_autobind = 1;
 190
 191         clnt->cl_rtt = &clnt->cl_rtt_default;
 192         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 193
 194         kref_init(&clnt->cl_kref);
 195
 196         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 197         if (err < 0)
 198                 goto out_no_path;
 199
 200         auth = rpcauth_create(args->authflavor, clnt);
 201         if (IS_ERR(auth)) {
 202                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 203                                 args->authflavor);
 204                 err = PTR_ERR(auth);
 205                 goto out_no_auth;
 206         }
 207
 208         /* save the nodename */
 209         clnt->cl_nodelen = strlen(utsname()->nodename);
 210         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 211                 clnt->cl_nodelen = UNX_MAXNODENAME;
 212         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 213         rpc_register_client(clnt);
 214         return clnt;
 215
 216 out_no_auth:
 217         if (!IS_ERR(clnt->cl_dentry)) {
 218                 rpc_rmdir(clnt->cl_dentry);
 219                 rpc_put_mount();
 220         }
 221 out_no_path:
 222         rpc_free_iostats(clnt->cl_metrics);
 223 out_no_stats:
 224         if (clnt->cl_server != clnt->cl_inline_name)
 225                 kfree(clnt->cl_server);
 226         kfree(clnt);
 227 out_err:
 228         xprt_put(xprt);
 229 out_no_xprt:
 230         rpciod_down();
 231 out_no_rpciod:
 232         return ERR_PTR(err);
 233 }
 234
 235 /*
 236  * rpc_create - create an RPC client and transport with one call
 237  * @args: rpc_clnt create argument structure
 238  *
 239  * Creates and initializes an RPC transport and an RPC client.
 240  *
 241  * It can ping the server in order to determine if it is up, and to see if
 242  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 243  * this behavior so asynchronous tasks can also use rpc_create.
 244  */
 245 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 246 {
 247         struct rpc_xprt *xprt;
 248         struct rpc_clnt *clnt;
 249         struct xprt_create xprtargs = {
 250                 .ident = args->protocol,
 251                 .srcaddr = args->saddress,
 252                 .dstaddr = args->address,
 253                 .addrlen = args->addrsize,
 254                 .timeout = args->timeout
 255         };
 256         char servername[48];
 257
 258         xprt = xprt_create_transport(&xprtargs);
 259         if (IS_ERR(xprt))
 260                 return (struct rpc_clnt *)xprt;
 261
 262         /*
 263          * If the caller chooses not to specify a hostname, whip
 264          * up a string representation of the passed-in address.
 265          */
 266         if (args->servername == NULL) {
 267                 servername[0] = '\0';
 268                 switch (args->address->sa_family) {
 269                 case AF_INET: {
 270                         struct sockaddr_in *sin =
 271                                         (struct sockaddr_in *)args->address;
 272                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 273                                  NIPQUAD(sin->sin_addr.s_addr));
 274                         break;
 275                 }
 276                 case AF_INET6: {
 277                         struct sockaddr_in6 *sin =
 278                                         (struct sockaddr_in6 *)args->address;
 279                         snprintf(servername, sizeof(servername), NIP6_FMT,
 280                                  NIP6(sin->sin6_addr));
 281                         break;
 282                 }
 283                 default:
 284                         /* caller wants default server name, but
 285                          * address family isn't recognized. */
 286                         return ERR_PTR(-EINVAL);
 287                 }
 288                 args->servername = servername;
 289         }
 290
 291         xprt = xprt_create_transport(&xprtargs);
 292         if (IS_ERR(xprt))
 293                 return (struct rpc_clnt *)xprt;
 294
 295         /*
 296          * By default, kernel RPC client connects from a reserved port.
 297          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 298          * but it is always enabled for rpciod, which handles the connect
 299          * operation.
 300          */
 301         xprt->resvport = 1;
 302         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 303                 xprt->resvport = 0;
 304
 305         clnt = rpc_new_client(args, xprt);
 306         if (IS_ERR(clnt))
 307                 return clnt;
 308
 309         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 310                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 311                 if (err != 0) {
 312                         rpc_shutdown_client(clnt);
 313                         return ERR_PTR(err);
 314                 }
 315         }
 316
 317         clnt->cl_softrtry = 1;
 318         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 319                 clnt->cl_softrtry = 0;
 320
 321         if (args->flags & RPC_CLNT_CREATE_INTR)
 322                 clnt->cl_intr = 1;
 323         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 324                 clnt->cl_autobind = 1;
 325         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 326                 clnt->cl_discrtry = 1;
 327
 328         return clnt;
 329 }
 330 EXPORT_SYMBOL_GPL(rpc_create);
 331
 332 /*
 333  * This function clones the RPC client structure. It allows us to share the
 334  * same transport while varying parameters such as the authentication
 335  * flavour.
 336  */
 337 struct rpc_clnt *
 338 rpc_clone_client(struct rpc_clnt *clnt)
 339 {
 340         struct rpc_clnt *new;
 341         int err = -ENOMEM;
 342
 343         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 344         if (!new)
 345                 goto out_no_clnt;
 346         new->cl_parent = clnt;
 347         /* Turn off autobind on clones */
 348         new->cl_autobind = 0;
 349         INIT_LIST_HEAD(&new->cl_tasks);
 350         spin_lock_init(&new->cl_lock);
 351         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 352         new->cl_metrics = rpc_alloc_iostats(clnt);
 353         if (new->cl_metrics == NULL)
 354                 goto out_no_stats;
 355         kref_init(&new->cl_kref);
 356         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 357         if (err != 0)
 358                 goto out_no_path;
 359         if (new->cl_auth)
 360                 atomic_inc(&new->cl_auth->au_count);
 361         xprt_get(clnt->cl_xprt);
 362         kref_get(&clnt->cl_kref);
 363         rpc_register_client(new);
 364         rpciod_up();
 365         return new;
 366 out_no_path:
 367         rpc_free_iostats(new->cl_metrics);
 368 out_no_stats:
 369         kfree(new);
 370 out_no_clnt:
 371         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 372         return ERR_PTR(err);
 373 }
 374 EXPORT_SYMBOL_GPL(rpc_clone_client);
 375
 376 /*
 377  * Properly shut down an RPC client, terminating all outstanding
 378  * requests.
 379  */
 380 void rpc_shutdown_client(struct rpc_clnt *clnt)
 381 {
 382         dprintk("RPC:       shutting down %s client for %s\n",
 383                         clnt->cl_protname, clnt->cl_server);
 384
 385         while (!list_empty(&clnt->cl_tasks)) {
 386                 rpc_killall_tasks(clnt);
 387                 wait_event_timeout(destroy_wait,
 388                         list_empty(&clnt->cl_tasks), 1*HZ);
 389         }
 390
 391         rpc_release_client(clnt);
 392 }
 393 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 394
 395 /*
 396  * Free an RPC client
 397  */
 398 static void
 399 rpc_free_client(struct kref *kref)
 400 {
 401         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 402
 403         dprintk("RPC:       destroying %s client for %s\n",
 404                         clnt->cl_protname, clnt->cl_server);
 405         if (!IS_ERR(clnt->cl_dentry)) {
 406                 rpc_rmdir(clnt->cl_dentry);
 407                 rpc_put_mount();
 408         }
 409         if (clnt->cl_parent != clnt) {
 410                 rpc_release_client(clnt->cl_parent);
 411                 goto out_free;
 412         }
 413         if (clnt->cl_server != clnt->cl_inline_name)
 414                 kfree(clnt->cl_server);
 415 out_free:
 416         rpc_unregister_client(clnt);
 417         rpc_free_iostats(clnt->cl_metrics);
 418         clnt->cl_metrics = NULL;
 419         xprt_put(clnt->cl_xprt);
 420         rpciod_down();
 421         kfree(clnt);
 422 }
 423
 424 /*
 425  * Free an RPC client
 426  */
 427 static void
 428 rpc_free_auth(struct kref *kref)
 429 {
 430         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 431
 432         if (clnt->cl_auth == NULL) {
 433                 rpc_free_client(kref);
 434                 return;
 435         }
 436
 437         /*
 438          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 439          *       release remaining GSS contexts. This mechanism ensures
 440          *       that it can do so safely.
 441          */
 442         kref_init(kref);
 443         rpcauth_release(clnt->cl_auth);
 444         clnt->cl_auth = NULL;
 445         kref_put(kref, rpc_free_client);
 446 }
 447
 448 /*
 449  * Release reference to the RPC client
 450  */
 451 void
 452 rpc_release_client(struct rpc_clnt *clnt)
 453 {
 454         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 455
 456         if (list_empty(&clnt->cl_tasks))
 457                 wake_up(&destroy_wait);
 458         kref_put(&clnt->cl_kref, rpc_free_auth);
 459 }
 460
 461 /**
 462  * rpc_bind_new_program - bind a new RPC program to an existing client
 463  * @old - old rpc_client
 464  * @program - rpc program to set
 465  * @vers - rpc program version
 466  *
 467  * Clones the rpc client and sets up a new RPC program. This is mainly
 468  * of use for enabling different RPC programs to share the same transport.
 469  * The Sun NFSv2/v3 ACL protocol can do this.
 470  */
 471 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 472                                       struct rpc_program *program,
 473                                       u32 vers)
 474 {
 475         struct rpc_clnt *clnt;
 476         struct rpc_version *version;
 477         int err;
 478
 479         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 480         version = program->version[vers];
 481         clnt = rpc_clone_client(old);
 482         if (IS_ERR(clnt))
 483                 goto out;
 484         clnt->cl_procinfo = version->procs;
 485         clnt->cl_maxproc  = version->nrprocs;
 486         clnt->cl_protname = program->name;
 487         clnt->cl_prog     = program->number;
 488         clnt->cl_vers     = version->number;
 489         clnt->cl_stats    = program->stats;
 490         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 491         if (err != 0) {
 492                 rpc_shutdown_client(clnt);
 493                 clnt = ERR_PTR(err);
 494         }
 495 out:
 496         return clnt;
 497 }
 498 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 499
 500 /*
 501  * Default callback for async RPC calls
 502  */
 503 static void
 504 rpc_default_callback(struct rpc_task *task, void *data)
 505 {
 506 }
 507
 508 static const struct rpc_call_ops rpc_default_ops = {
 509         .rpc_call_done = rpc_default_callback,
 510 };
 511
 512 /*
 513  *      Export the signal mask handling for synchronous code that
 514  *      sleeps on RPC calls
 515  */
 516 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 517
 518 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 519 {
 520         unsigned long   sigallow = sigmask(SIGKILL);
 521         sigset_t sigmask;
 522
 523         /* Block all signals except those listed in sigallow */
 524         if (intr)
 525                 sigallow |= RPC_INTR_SIGNALS;
 526         siginitsetinv(&sigmask, sigallow);
 527         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 528 }
 529
 530 static void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 531 {
 532         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 533 }
 534
 535 static void rpc_restore_sigmask(sigset_t *oldset)
 536 {
 537         sigprocmask(SIG_SETMASK, oldset, NULL);
 538 }
 539
 540 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 541 {
 542         rpc_save_sigmask(oldset, clnt->cl_intr);
 543 }
 544 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 545
 546 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 547 {
 548         rpc_restore_sigmask(oldset);
 549 }
 550 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 551
 552 /**
 553  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 554  * @task_setup_data: pointer to task initialisation data
 555  */
 556 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 557 {
 558         struct rpc_task *task, *ret;
 559         sigset_t oldset;
 560
 561         task = rpc_new_task(task_setup_data);
 562         if (task == NULL) {
 563                 rpc_release_calldata(task_setup_data->callback_ops,
 564                                 task_setup_data->callback_data);
 565                 ret = ERR_PTR(-ENOMEM);
 566                 goto out;
 567         }
 568
 569         if (task->tk_status != 0) {
 570                 ret = ERR_PTR(task->tk_status);
 571                 rpc_put_task(task);
 572                 goto out;
 573         }
 574         atomic_inc(&task->tk_count);
 575         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 576         rpc_task_sigmask(task, &oldset);
 577         rpc_execute(task);
 578         rpc_restore_sigmask(&oldset);
 579         ret = task;
 580 out:
 581         return ret;
 582 }
 583 EXPORT_SYMBOL_GPL(rpc_run_task);
 584
 585 /**
 586  * rpc_call_sync - Perform a synchronous RPC call
 587  * @clnt: pointer to RPC client
 588  * @msg: RPC call parameters
 589  * @flags: RPC call flags
 590  */
 591 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 592 {
 593         struct rpc_task *task;
 594         struct rpc_task_setup task_setup_data = {
 595                 .rpc_client = clnt,
 596                 .rpc_message = msg,
 597                 .callback_ops = &rpc_default_ops,
 598                 .flags = flags,
 599         };
 600         int status;
 601
 602         BUG_ON(flags & RPC_TASK_ASYNC);
 603
 604         task = rpc_run_task(&task_setup_data);
 605         if (IS_ERR(task))
 606                 return PTR_ERR(task);
 607         status = task->tk_status;
 608         rpc_put_task(task);
 609         return status;
 610 }
 611 EXPORT_SYMBOL_GPL(rpc_call_sync);
 612
 613 /**
 614  * rpc_call_async - Perform an asynchronous RPC call
 615  * @clnt: pointer to RPC client
 616  * @msg: RPC call parameters
 617  * @flags: RPC call flags
 618  * @ops: RPC call ops
 619  * @data: user call data
 620  */
 621 int
 622 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 623                const struct rpc_call_ops *tk_ops, void *data)
 624 {
 625         struct rpc_task *task;
 626         struct rpc_task_setup task_setup_data = {
 627                 .rpc_client = clnt,
 628                 .rpc_message = msg,
 629                 .callback_ops = tk_ops,
 630                 .callback_data = data,
 631                 .flags = flags|RPC_TASK_ASYNC,
 632         };
 633
 634         task = rpc_run_task(&task_setup_data);
 635         if (IS_ERR(task))
 636                 return PTR_ERR(task);
 637         rpc_put_task(task);
 638         return 0;
 639 }
 640 EXPORT_SYMBOL_GPL(rpc_call_async);
 641
 642 void
 643 rpc_call_start(struct rpc_task *task)
 644 {
 645         task->tk_action = call_start;
 646 }
 647 EXPORT_SYMBOL_GPL(rpc_call_start);
 648
 649 /**
 650  * rpc_peeraddr - extract remote peer address from clnt's xprt
 651  * @clnt: RPC client structure
 652  * @buf: target buffer
 653  * @size: length of target buffer
 654  *
 655  * Returns the number of bytes that are actually in the stored address.
 656  */
 657 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 658 {
 659         size_t bytes;
 660         struct rpc_xprt *xprt = clnt->cl_xprt;
 661
 662         bytes = sizeof(xprt->addr);
 663         if (bytes > bufsize)
 664                 bytes = bufsize;
 665         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 666         return xprt->addrlen;
 667 }
 668 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 669
 670 /**
 671  * rpc_peeraddr2str - return remote peer address in printable format
 672  * @clnt: RPC client structure
 673  * @format: address format
 674  *
 675  */
 676 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 677 {
 678         struct rpc_xprt *xprt = clnt->cl_xprt;
 679
 680         if (xprt->address_strings[format] != NULL)
 681                 return xprt->address_strings[format];
 682         else
 683                 return "unprintable";
 684 }
 685 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 686
 687 void
 688 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 689 {
 690         struct rpc_xprt *xprt = clnt->cl_xprt;
 691         if (xprt->ops->set_buffer_size)
 692                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 693 }
 694 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 695
 696 /*
 697  * Return size of largest payload RPC client can support, in bytes
 698  *
 699  * For stream transports, this is one RPC record fragment (see RFC
 700  * 1831), as we don't support multi-record requests yet.  For datagram
 701  * transports, this is the size of an IP packet minus the IP, UDP, and
 702  * RPC header sizes.
 703  */
 704 size_t rpc_max_payload(struct rpc_clnt *clnt)
 705 {
 706         return clnt->cl_xprt->max_payload;
 707 }
 708 EXPORT_SYMBOL_GPL(rpc_max_payload);
 709
 710 /**
 711  * rpc_force_rebind - force transport to check that remote port is unchanged
 712  * @clnt: client to rebind
 713  *
 714  */
 715 void rpc_force_rebind(struct rpc_clnt *clnt)
 716 {
 717         if (clnt->cl_autobind)
 718                 xprt_clear_bound(clnt->cl_xprt);
 719 }
 720 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 721
 722 /*
 723  * Restart an (async) RPC call. Usually called from within the
 724  * exit handler.
 725  */
 726 void
 727 rpc_restart_call(struct rpc_task *task)
 728 {
 729         if (RPC_ASSASSINATED(task))
 730                 return;
 731
 732         task->tk_action = call_start;
 733 }
 734 EXPORT_SYMBOL_GPL(rpc_restart_call);
 735
 736 /*
 737  * 0.  Initial state
 738  *
 739  *     Other FSM states can be visited zero or more times, but
 740  *     this state is visited exactly once for each RPC.
 741  */
 742 static void
 743 call_start(struct rpc_task *task)
 744 {
 745         struct rpc_clnt *clnt = task->tk_client;
 746
 747         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 748                         clnt->cl_protname, clnt->cl_vers,
 749                         task->tk_msg.rpc_proc->p_proc,
 750                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 751
 752         /* Increment call count */
 753         task->tk_msg.rpc_proc->p_count++;
 754         clnt->cl_stats->rpccnt++;
 755         task->tk_action = call_reserve;
 756 }
 757
 758 /*
 759  * 1.   Reserve an RPC call slot
 760  */
 761 static void
 762 call_reserve(struct rpc_task *task)
 763 {
 764         dprint_status(task);
 765
 766         if (!rpcauth_uptodatecred(task)) {
 767                 task->tk_action = call_refresh;
 768                 return;
 769         }
 770
 771         task->tk_status  = 0;
 772         task->tk_action  = call_reserveresult;
 773         xprt_reserve(task);
 774 }
 775
 776 /*
 777  * 1b.  Grok the result of xprt_reserve()
 778  */
 779 static void
 780 call_reserveresult(struct rpc_task *task)
 781 {
 782         int status = task->tk_status;
 783
 784         dprint_status(task);
 785
 786         /*
 787          * After a call to xprt_reserve(), we must have either
 788          * a request slot or else an error status.
 789          */
 790         task->tk_status = 0;
 791         if (status >= 0) {
 792                 if (task->tk_rqstp) {
 793                         task->tk_action = call_allocate;
 794                         return;
 795                 }
 796
 797                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 798                                 __FUNCTION__, status);
 799                 rpc_exit(task, -EIO);
 800                 return;
 801         }
 802
 803         /*
 804          * Even though there was an error, we may have acquired
 805          * a request slot somehow.  Make sure not to leak it.
 806          */
 807         if (task->tk_rqstp) {
 808                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 809                                 __FUNCTION__, status);
 810                 xprt_release(task);
 811         }
 812
 813         switch (status) {
 814         case -EAGAIN:   /* woken up; retry */
 815                 task->tk_action = call_reserve;
 816                 return;
 817         case -EIO:      /* probably a shutdown */
 818                 break;
 819         default:
 820                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 821                                 __FUNCTION__, status);
 822                 break;
 823         }
 824         rpc_exit(task, status);
 825 }
 826
 827 /*
 828  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 829  *      (Note: buffer memory is freed in xprt_release).
 830  */
 831 static void
 832 call_allocate(struct rpc_task *task)
 833 {
 834         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 835         struct rpc_rqst *req = task->tk_rqstp;
 836         struct rpc_xprt *xprt = task->tk_xprt;
 837         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 838
 839         dprint_status(task);
 840
 841         task->tk_status = 0;
 842         task->tk_action = call_bind;
 843
 844         if (req->rq_buffer)
 845                 return;
 846
 847         if (proc->p_proc != 0) {
 848                 BUG_ON(proc->p_arglen == 0);
 849                 if (proc->p_decode != NULL)
 850                         BUG_ON(proc->p_replen == 0);
 851         }
 852
 853         /*
 854          * Calculate the size (in quads) of the RPC call
 855          * and reply headers, and convert both values
 856          * to byte sizes.
 857          */
 858         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 859         req->rq_callsize <<= 2;
 860         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 861         req->rq_rcvsize <<= 2;
 862
 863         req->rq_buffer = xprt->ops->buf_alloc(task,
 864                                         req->rq_callsize + req->rq_rcvsize);
 865         if (req->rq_buffer != NULL)
 866                 return;
 867
 868         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 869
 870         if (RPC_IS_ASYNC(task) || !signalled()) {
 871                 task->tk_action = call_allocate;
 872                 rpc_delay(task, HZ>>4);
 873                 return;
 874         }
 875
 876         rpc_exit(task, -ERESTARTSYS);
 877 }
 878
 879 static inline int
 880 rpc_task_need_encode(struct rpc_task *task)
 881 {
 882         return task->tk_rqstp->rq_snd_buf.len == 0;
 883 }
 884
 885 static inline void
 886 rpc_task_force_reencode(struct rpc_task *task)
 887 {
 888         task->tk_rqstp->rq_snd_buf.len = 0;
 889 }
 890
 891 static inline void
 892 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 893 {
 894         buf->head[0].iov_base = start;
 895         buf->head[0].iov_len = len;
 896         buf->tail[0].iov_len = 0;
 897         buf->page_len = 0;
 898         buf->flags = 0;
 899         buf->len = 0;
 900         buf->buflen = len;
 901 }
 902
 903 /*
 904  * 3.   Encode arguments of an RPC call
 905  */
 906 static void
 907 call_encode(struct rpc_task *task)
 908 {
 909         struct rpc_rqst *req = task->tk_rqstp;
 910         kxdrproc_t      encode;
 911         __be32          *p;
 912
 913         dprint_status(task);
 914
 915         rpc_xdr_buf_init(&req->rq_snd_buf,
 916                          req->rq_buffer,
 917                          req->rq_callsize);
 918         rpc_xdr_buf_init(&req->rq_rcv_buf,
 919                          (char *)req->rq_buffer + req->rq_callsize,
 920                          req->rq_rcvsize);
 921
 922         /* Encode header and provided arguments */
 923         encode = task->tk_msg.rpc_proc->p_encode;
 924         if (!(p = call_header(task))) {
 925                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 926                 rpc_exit(task, -EIO);
 927                 return;
 928         }
 929         if (encode == NULL)
 930                 return;
 931
 932         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 933                         task->tk_msg.rpc_argp);
 934         if (task->tk_status == -ENOMEM) {
 935                 /* XXX: Is this sane? */
 936                 rpc_delay(task, 3*HZ);
 937                 task->tk_status = -EAGAIN;
 938         }
 939 }
 940
 941 /*
 942  * 4.   Get the server port number if not yet set
 943  */
 944 static void
 945 call_bind(struct rpc_task *task)
 946 {
 947         struct rpc_xprt *xprt = task->tk_xprt;
 948
 949         dprint_status(task);
 950
 951         task->tk_action = call_connect;
 952         if (!xprt_bound(xprt)) {
 953                 task->tk_action = call_bind_status;
 954                 task->tk_timeout = xprt->bind_timeout;
 955                 xprt->ops->rpcbind(task);
 956         }
 957 }
 958
 959 /*
 960  * 4a.  Sort out bind result
 961  */
 962 static void
 963 call_bind_status(struct rpc_task *task)
 964 {
 965         int status = -EIO;
 966
 967         if (task->tk_status >= 0) {
 968                 dprint_status(task);
 969                 task->tk_status = 0;
 970                 task->tk_action = call_connect;
 971                 return;
 972         }
 973
 974         switch (task->tk_status) {
 975         case -EAGAIN:
 976                 dprintk("RPC: %5u rpcbind waiting for another request "
 977                                 "to finish\n", task->tk_pid);
 978                 /* avoid busy-waiting here -- could be a network outage. */
 979                 rpc_delay(task, 5*HZ);
 980                 goto retry_timeout;
 981         case -EACCES:
 982                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 983                                 "unavailable\n", task->tk_pid);
 984                 /* fail immediately if this is an RPC ping */
 985                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 986                         status = -EOPNOTSUPP;
 987                         break;
 988                 }
 989                 rpc_delay(task, 3*HZ);
 990                 goto retry_timeout;
 991         case -ETIMEDOUT:
 992                 dprintk("RPC: %5u rpcbind request timed out\n",
 993                                 task->tk_pid);
 994                 goto retry_timeout;
 995         case -EPFNOSUPPORT:
 996                 /* server doesn't support any rpcbind version we know of */
 997                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 998                                 task->tk_pid);
 999                 break;
1000         case -EPROTONOSUPPORT:
1001                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1002                                 task->tk_pid);
1003                 task->tk_status = 0;
1004                 task->tk_action = call_bind;
1005                 return;
1006         default:
1007                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1008                                 task->tk_pid, -task->tk_status);
1009         }
1010
1011         rpc_exit(task, status);
1012         return;
1013
1014 retry_timeout:
1015         task->tk_action = call_timeout;
1016 }
1017
1018 /*
1019  * 4b.  Connect to the RPC server
1020  */
1021 static void
1022 call_connect(struct rpc_task *task)
1023 {
1024         struct rpc_xprt *xprt = task->tk_xprt;
1025
1026         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1027                         task->tk_pid, xprt,
1028                         (xprt_connected(xprt) ? "is" : "is not"));
1029
1030         task->tk_action = call_transmit;
1031         if (!xprt_connected(xprt)) {
1032                 task->tk_action = call_connect_status;
1033                 if (task->tk_status < 0)
1034                         return;
1035                 xprt_connect(task);
1036         }
1037 }
1038
1039 /*
1040  * 4c.  Sort out connect result
1041  */
1042 static void
1043 call_connect_status(struct rpc_task *task)
1044 {
1045         struct rpc_clnt *clnt = task->tk_client;
1046         int status = task->tk_status;
1047
1048         dprint_status(task);
1049
1050         task->tk_status = 0;
1051         if (status >= 0) {
1052                 clnt->cl_stats->netreconn++;
1053                 task->tk_action = call_transmit;
1054                 return;
1055         }
1056
1057         /* Something failed: remote service port may have changed */
1058         rpc_force_rebind(clnt);
1059
1060         switch (status) {
1061         case -ENOTCONN:
1062         case -EAGAIN:
1063                 task->tk_action = call_bind;
1064                 if (!RPC_IS_SOFT(task))
1065                         return;
1066                 /* if soft mounted, test if we've timed out */
1067         case -ETIMEDOUT:
1068                 task->tk_action = call_timeout;
1069                 return;
1070         }
1071         rpc_exit(task, -EIO);
1072 }
1073
1074 /*
1075  * 5.   Transmit the RPC request, and wait for reply
1076  */
1077 static void
1078 call_transmit(struct rpc_task *task)
1079 {
1080         dprint_status(task);
1081
1082         task->tk_action = call_status;
1083         if (task->tk_status < 0)
1084                 return;
1085         task->tk_status = xprt_prepare_transmit(task);
1086         if (task->tk_status != 0)
1087                 return;
1088         task->tk_action = call_transmit_status;
1089         /* Encode here so that rpcsec_gss can use correct sequence number. */
1090         if (rpc_task_need_encode(task)) {
1091                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1092                 call_encode(task);
1093                 /* Did the encode result in an error condition? */
1094                 if (task->tk_status != 0)
1095                         return;
1096         }
1097         xprt_transmit(task);
1098         if (task->tk_status < 0)
1099                 return;
1100         /*
1101          * On success, ensure that we call xprt_end_transmit() before sleeping
1102          * in order to allow access to the socket to other RPC requests.
1103          */
1104         call_transmit_status(task);
1105         if (task->tk_msg.rpc_proc->p_decode != NULL)
1106                 return;
1107         task->tk_action = rpc_exit_task;
1108         rpc_wake_up_task(task);
1109 }
1110
1111 /*
1112  * 5a.  Handle cleanup after a transmission
1113  */
1114 static void
1115 call_transmit_status(struct rpc_task *task)
1116 {
1117         task->tk_action = call_status;
1118         /*
1119          * Special case: if we've been waiting on the socket's write_space()
1120          * callback, then don't call xprt_end_transmit().
1121          */
1122         if (task->tk_status == -EAGAIN)
1123                 return;
1124         xprt_end_transmit(task);
1125         rpc_task_force_reencode(task);
1126 }
1127
1128 /*
1129  * 6.   Sort out the RPC call status
1130  */
1131 static void
1132 call_status(struct rpc_task *task)
1133 {
1134         struct rpc_clnt *clnt = task->tk_client;
1135         struct rpc_rqst *req = task->tk_rqstp;
1136         int             status;
1137
1138         if (req->rq_received > 0 && !req->rq_bytes_sent)
1139                 task->tk_status = req->rq_received;
1140
1141         dprint_status(task);
1142
1143         status = task->tk_status;
1144         if (status >= 0) {
1145                 task->tk_action = call_decode;
1146                 return;
1147         }
1148
1149         task->tk_status = 0;
1150         switch(status) {
1151         case -EHOSTDOWN:
1152         case -EHOSTUNREACH:
1153         case -ENETUNREACH:
1154                 /*
1155                  * Delay any retries for 3 seconds, then handle as if it
1156                  * were a timeout.
1157                  */
1158                 rpc_delay(task, 3*HZ);
1159         case -ETIMEDOUT:
1160                 task->tk_action = call_timeout;
1161                 if (task->tk_client->cl_discrtry)
1162                         xprt_force_disconnect(task->tk_xprt);
1163                 break;
1164         case -ECONNREFUSED:
1165         case -ENOTCONN:
1166                 rpc_force_rebind(clnt);
1167                 task->tk_action = call_bind;
1168                 break;
1169         case -EAGAIN:
1170                 task->tk_action = call_transmit;
1171                 break;
1172         case -EIO:
1173                 /* shutdown or soft timeout */
1174                 rpc_exit(task, status);
1175                 break;
1176         default:
1177                 printk("%s: RPC call returned error %d\n",
1178                                clnt->cl_protname, -status);
1179                 rpc_exit(task, status);
1180         }
1181 }
1182
1183 /*
1184  * 6a.  Handle RPC timeout
1185  *      We do not release the request slot, so we keep using the
1186  *      same XID for all retransmits.
1187  */
1188 static void
1189 call_timeout(struct rpc_task *task)
1190 {
1191         struct rpc_clnt *clnt = task->tk_client;
1192
1193         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1194                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1195                 goto retry;
1196         }
1197
1198         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1199         task->tk_timeouts++;
1200
1201         if (RPC_IS_SOFT(task)) {
1202                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1203                                 clnt->cl_protname, clnt->cl_server);
1204                 rpc_exit(task, -EIO);
1205                 return;
1206         }
1207
1208         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1209                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1210                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1211                         clnt->cl_protname, clnt->cl_server);
1212         }
1213         rpc_force_rebind(clnt);
1214
1215 retry:
1216         clnt->cl_stats->rpcretrans++;
1217         task->tk_action = call_bind;
1218         task->tk_status = 0;
1219 }
1220
1221 /*
1222  * 7.   Decode the RPC reply
1223  */
1224 static void
1225 call_decode(struct rpc_task *task)
1226 {
1227         struct rpc_clnt *clnt = task->tk_client;
1228         struct rpc_rqst *req = task->tk_rqstp;
1229         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1230         __be32          *p;
1231
1232         dprintk("RPC: %5u call_decode (status %d)\n",
1233                         task->tk_pid, task->tk_status);
1234
1235         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1236                 printk(KERN_NOTICE "%s: server %s OK\n",
1237                         clnt->cl_protname, clnt->cl_server);
1238                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1239         }
1240
1241         if (task->tk_status < 12) {
1242                 if (!RPC_IS_SOFT(task)) {
1243                         task->tk_action = call_bind;
1244                         clnt->cl_stats->rpcretrans++;
1245                         goto out_retry;
1246                 }
1247                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1248                                 clnt->cl_protname, task->tk_status);
1249                 task->tk_action = call_timeout;
1250                 goto out_retry;
1251         }
1252
1253         /*
1254          * Ensure that we see all writes made by xprt_complete_rqst()
1255          * before it changed req->rq_received.
1256          */
1257         smp_rmb();
1258         req->rq_rcv_buf.len = req->rq_private_buf.len;
1259
1260         /* Check that the softirq receive buffer is valid */
1261         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1262                                 sizeof(req->rq_rcv_buf)) != 0);
1263
1264         /* Verify the RPC header */
1265         p = call_verify(task);
1266         if (IS_ERR(p)) {
1267                 if (p == ERR_PTR(-EAGAIN))
1268                         goto out_retry;
1269                 return;
1270         }
1271
1272         task->tk_action = rpc_exit_task;
1273
1274         if (decode) {
1275                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1276                                                       task->tk_msg.rpc_resp);
1277         }
1278         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1279                         task->tk_status);
1280         return;
1281 out_retry:
1282         req->rq_received = req->rq_private_buf.len = 0;
1283         task->tk_status = 0;
1284         if (task->tk_client->cl_discrtry)
1285                 xprt_force_disconnect(task->tk_xprt);
1286 }
1287
1288 /*
1289  * 8.   Refresh the credentials if rejected by the server
1290  */
1291 static void
1292 call_refresh(struct rpc_task *task)
1293 {
1294         dprint_status(task);
1295
1296         task->tk_action = call_refreshresult;
1297         task->tk_status = 0;
1298         task->tk_client->cl_stats->rpcauthrefresh++;
1299         rpcauth_refreshcred(task);
1300 }
1301
1302 /*
1303  * 8a.  Process the results of a credential refresh
1304  */
1305 static void
1306 call_refreshresult(struct rpc_task *task)
1307 {
1308         int status = task->tk_status;
1309
1310         dprint_status(task);
1311
1312         task->tk_status = 0;
1313         task->tk_action = call_reserve;
1314         if (status >= 0 && rpcauth_uptodatecred(task))
1315                 return;
1316         if (status == -EACCES) {
1317                 rpc_exit(task, -EACCES);
1318                 return;
1319         }
1320         task->tk_action = call_refresh;
1321         if (status != -ETIMEDOUT)
1322                 rpc_delay(task, 3*HZ);
1323         return;
1324 }
1325
1326 /*
1327  * Call header serialization
1328  */
1329 static __be32 *
1330 call_header(struct rpc_task *task)
1331 {
1332         struct rpc_clnt *clnt = task->tk_client;
1333         struct rpc_rqst *req = task->tk_rqstp;
1334         __be32          *p = req->rq_svec[0].iov_base;
1335
1336         /* FIXME: check buffer size? */
1337
1338         p = xprt_skip_transport_header(task->tk_xprt, p);
1339         *p++ = req->rq_xid;             /* XID */
1340         *p++ = htonl(RPC_CALL);         /* CALL */
1341         *p++ = htonl(RPC_VERSION);      /* RPC version */
1342         *p++ = htonl(clnt->cl_prog);    /* program number */
1343         *p++ = htonl(clnt->cl_vers);    /* program version */
1344         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1345         p = rpcauth_marshcred(task, p);
1346         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1347         return p;
1348 }
1349
1350 /*
1351  * Reply header verification
1352  */
1353 static __be32 *
1354 call_verify(struct rpc_task *task)
1355 {
1356         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1357         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1358         __be32  *p = iov->iov_base;
1359         u32 n;
1360         int error = -EACCES;
1361
1362         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1363                 /* RFC-1014 says that the representation of XDR data must be a
1364                  * multiple of four bytes
1365                  * - if it isn't pointer subtraction in the NFS client may give
1366                  *   undefined results
1367                  */
1368                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1369                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1370                        task->tk_rqstp->rq_rcv_buf.len);
1371                 goto out_eio;
1372         }
1373         if ((len -= 3) < 0)
1374                 goto out_overflow;
1375         p += 1; /* skip XID */
1376
1377         if ((n = ntohl(*p++)) != RPC_REPLY) {
1378                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1379                                 task->tk_pid, __FUNCTION__, n);
1380                 goto out_garbage;
1381         }
1382         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1383                 if (--len < 0)
1384                         goto out_overflow;
1385                 switch ((n = ntohl(*p++))) {
1386                         case RPC_AUTH_ERROR:
1387                                 break;
1388                         case RPC_MISMATCH:
1389                                 dprintk("RPC: %5u %s: RPC call version "
1390                                                 "mismatch!\n",
1391                                                 task->tk_pid, __FUNCTION__);
1392                                 error = -EPROTONOSUPPORT;
1393                                 goto out_err;
1394                         default:
1395                                 dprintk("RPC: %5u %s: RPC call rejected, "
1396                                                 "unknown error: %x\n",
1397                                                 task->tk_pid, __FUNCTION__, n);
1398                                 goto out_eio;
1399                 }
1400                 if (--len < 0)
1401                         goto out_overflow;
1402                 switch ((n = ntohl(*p++))) {
1403                 case RPC_AUTH_REJECTEDCRED:
1404                 case RPC_AUTH_REJECTEDVERF:
1405                 case RPCSEC_GSS_CREDPROBLEM:
1406                 case RPCSEC_GSS_CTXPROBLEM:
1407                         if (!task->tk_cred_retry)
1408                                 break;
1409                         task->tk_cred_retry--;
1410                         dprintk("RPC: %5u %s: retry stale creds\n",
1411                                         task->tk_pid, __FUNCTION__);
1412                         rpcauth_invalcred(task);
1413                         /* Ensure we obtain a new XID! */
1414                         xprt_release(task);
1415                         task->tk_action = call_refresh;
1416                         goto out_retry;
1417                 case RPC_AUTH_BADCRED:
1418                 case RPC_AUTH_BADVERF:
1419                         /* possibly garbled cred/verf? */
1420                         if (!task->tk_garb_retry)
1421                                 break;
1422                         task->tk_garb_retry--;
1423                         dprintk("RPC: %5u %s: retry garbled creds\n",
1424                                         task->tk_pid, __FUNCTION__);
1425                         task->tk_action = call_bind;
1426                         goto out_retry;
1427                 case RPC_AUTH_TOOWEAK:
1428                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1429                                "authentication.\n", task->tk_client->cl_server);
1430                         break;
1431                 default:
1432                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1433                                         task->tk_pid, __FUNCTION__, n);
1434                         error = -EIO;
1435                 }
1436                 dprintk("RPC: %5u %s: call rejected %d\n",
1437                                 task->tk_pid, __FUNCTION__, n);
1438                 goto out_err;
1439         }
1440         if (!(p = rpcauth_checkverf(task, p))) {
1441                 dprintk("RPC: %5u %s: auth check failed\n",
1442                                 task->tk_pid, __FUNCTION__);
1443                 goto out_garbage;               /* bad verifier, retry */
1444         }
1445         len = p - (__be32 *)iov->iov_base - 1;
1446         if (len < 0)
1447                 goto out_overflow;
1448         switch ((n = ntohl(*p++))) {
1449         case RPC_SUCCESS:
1450                 return p;
1451         case RPC_PROG_UNAVAIL:
1452                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1453                                 task->tk_pid, __FUNCTION__,
1454                                 (unsigned int)task->tk_client->cl_prog,
1455                                 task->tk_client->cl_server);
1456                 error = -EPFNOSUPPORT;
1457                 goto out_err;
1458         case RPC_PROG_MISMATCH:
1459                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1460                                 "server %s\n", task->tk_pid, __FUNCTION__,
1461                                 (unsigned int)task->tk_client->cl_prog,
1462                                 (unsigned int)task->tk_client->cl_vers,
1463                                 task->tk_client->cl_server);
1464                 error = -EPROTONOSUPPORT;
1465                 goto out_err;
1466         case RPC_PROC_UNAVAIL:
1467                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1468                                 "version %u on server %s\n",
1469                                 task->tk_pid, __FUNCTION__,
1470                                 task->tk_msg.rpc_proc,
1471                                 task->tk_client->cl_prog,
1472                                 task->tk_client->cl_vers,
1473                                 task->tk_client->cl_server);
1474                 error = -EOPNOTSUPP;
1475                 goto out_err;
1476         case RPC_GARBAGE_ARGS:
1477                 dprintk("RPC: %5u %s: server saw garbage\n",
1478                                 task->tk_pid, __FUNCTION__);
1479                 break;                  /* retry */
1480         default:
1481                 dprintk("RPC: %5u %s: server accept status: %x\n",
1482                                 task->tk_pid, __FUNCTION__, n);
1483                 /* Also retry */
1484         }
1485
1486 out_garbage:
1487         task->tk_client->cl_stats->rpcgarbage++;
1488         if (task->tk_garb_retry) {
1489                 task->tk_garb_retry--;
1490                 dprintk("RPC: %5u %s: retrying\n",
1491                                 task->tk_pid, __FUNCTION__);
1492                 task->tk_action = call_bind;
1493 out_retry:
1494                 return ERR_PTR(-EAGAIN);
1495         }
1496 out_eio:
1497         error = -EIO;
1498 out_err:
1499         rpc_exit(task, error);
1500         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1501                         __FUNCTION__, error);
1502         return ERR_PTR(error);
1503 out_overflow:
1504         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1505                         __FUNCTION__);
1506         goto out_garbage;
1507 }
1508
1509 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1510 {
1511         return 0;
1512 }
1513
1514 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1515 {
1516         return 0;
1517 }
1518
1519 static struct rpc_procinfo rpcproc_null = {
1520         .p_encode = rpcproc_encode_null,
1521         .p_decode = rpcproc_decode_null,
1522 };
1523
1524 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1525 {
1526         struct rpc_message msg = {
1527                 .rpc_proc = &rpcproc_null,
1528         };
1529         int err;
1530         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1531         err = rpc_call_sync(clnt, &msg, flags);
1532         put_rpccred(msg.rpc_cred);
1533         return err;
1534 }
1535
1536 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1537 {
1538         struct rpc_message msg = {
1539                 .rpc_proc = &rpcproc_null,
1540                 .rpc_cred = cred,
1541         };
1542         struct rpc_task_setup task_setup_data = {
1543                 .rpc_client = clnt,
1544                 .rpc_message = &msg,
1545                 .callback_ops = &rpc_default_ops,
1546                 .flags = flags,
1547         };
1548         return rpc_run_task(&task_setup_data);
1549 }
1550 EXPORT_SYMBOL_GPL(rpc_call_null);
1551
1552 #ifdef RPC_DEBUG
1553 void rpc_show_tasks(void)
1554 {
1555         struct rpc_clnt *clnt;
1556         struct rpc_task *t;
1557
1558         spin_lock(&rpc_client_lock);
1559         if (list_empty(&all_clients))
1560                 goto out;
1561         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1562                 "-rpcwait -action- ---ops--\n");
1563         list_for_each_entry(clnt, &all_clients, cl_clients) {
1564                 if (list_empty(&clnt->cl_tasks))
1565                         continue;
1566                 spin_lock(&clnt->cl_lock);
1567                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1568                         const char *rpc_waitq = "none";
1569                         int proc;
1570
1571                         if (t->tk_msg.rpc_proc)
1572                                 proc = t->tk_msg.rpc_proc->p_proc;
1573                         else
1574                                 proc = -1;
1575
1576                         if (RPC_IS_QUEUED(t))
1577                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1578
1579                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1580                                 t->tk_pid, proc,
1581                                 t->tk_flags, t->tk_status,
1582                                 t->tk_client,
1583                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1584                                 t->tk_rqstp, t->tk_timeout,
1585                                 rpc_waitq,
1586                                 t->tk_action, t->tk_ops);
1587                 }
1588                 spin_unlock(&clnt->cl_lock);
1589         }
1590 out:
1591         spin_unlock(&rpc_client_lock);
1592 }
1593 #endif