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   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_timeout = xprt->timeout;
 192         if (args->timeout != NULL) {
 193                 memcpy(&clnt->cl_timeout_default, args->timeout,
 194                                 sizeof(clnt->cl_timeout_default));
 195                 clnt->cl_timeout = &clnt->cl_timeout_default;
 196         }
 197
 198         clnt->cl_rtt = &clnt->cl_rtt_default;
 199         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 200
 201         kref_init(&clnt->cl_kref);
 202
 203         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 204         if (err < 0)
 205                 goto out_no_path;
 206
 207         auth = rpcauth_create(args->authflavor, clnt);
 208         if (IS_ERR(auth)) {
 209                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 210                                 args->authflavor);
 211                 err = PTR_ERR(auth);
 212                 goto out_no_auth;
 213         }
 214
 215         /* save the nodename */
 216         clnt->cl_nodelen = strlen(utsname()->nodename);
 217         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 218                 clnt->cl_nodelen = UNX_MAXNODENAME;
 219         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 220         rpc_register_client(clnt);
 221         return clnt;
 222
 223 out_no_auth:
 224         if (!IS_ERR(clnt->cl_dentry)) {
 225                 rpc_rmdir(clnt->cl_dentry);
 226                 rpc_put_mount();
 227         }
 228 out_no_path:
 229         rpc_free_iostats(clnt->cl_metrics);
 230 out_no_stats:
 231         if (clnt->cl_server != clnt->cl_inline_name)
 232                 kfree(clnt->cl_server);
 233         kfree(clnt);
 234 out_err:
 235         xprt_put(xprt);
 236 out_no_xprt:
 237         rpciod_down();
 238 out_no_rpciod:
 239         return ERR_PTR(err);
 240 }
 241
 242 /*
 243  * rpc_create - create an RPC client and transport with one call
 244  * @args: rpc_clnt create argument structure
 245  *
 246  * Creates and initializes an RPC transport and an RPC client.
 247  *
 248  * It can ping the server in order to determine if it is up, and to see if
 249  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 250  * this behavior so asynchronous tasks can also use rpc_create.
 251  */
 252 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 253 {
 254         struct rpc_xprt *xprt;
 255         struct rpc_clnt *clnt;
 256         struct xprt_create xprtargs = {
 257                 .ident = args->protocol,
 258                 .srcaddr = args->saddress,
 259                 .dstaddr = args->address,
 260                 .addrlen = args->addrsize,
 261         };
 262         char servername[48];
 263
 264         xprt = xprt_create_transport(&xprtargs);
 265         if (IS_ERR(xprt))
 266                 return (struct rpc_clnt *)xprt;
 267
 268         /*
 269          * If the caller chooses not to specify a hostname, whip
 270          * up a string representation of the passed-in address.
 271          */
 272         if (args->servername == NULL) {
 273                 servername[0] = '\0';
 274                 switch (args->address->sa_family) {
 275                 case AF_INET: {
 276                         struct sockaddr_in *sin =
 277                                         (struct sockaddr_in *)args->address;
 278                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 279                                  NIPQUAD(sin->sin_addr.s_addr));
 280                         break;
 281                 }
 282                 case AF_INET6: {
 283                         struct sockaddr_in6 *sin =
 284                                         (struct sockaddr_in6 *)args->address;
 285                         snprintf(servername, sizeof(servername), NIP6_FMT,
 286                                  NIP6(sin->sin6_addr));
 287                         break;
 288                 }
 289                 default:
 290                         /* caller wants default server name, but
 291                          * address family isn't recognized. */
 292                         return ERR_PTR(-EINVAL);
 293                 }
 294                 args->servername = servername;
 295         }
 296
 297         xprt = xprt_create_transport(&xprtargs);
 298         if (IS_ERR(xprt))
 299                 return (struct rpc_clnt *)xprt;
 300
 301         /*
 302          * By default, kernel RPC client connects from a reserved port.
 303          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 304          * but it is always enabled for rpciod, which handles the connect
 305          * operation.
 306          */
 307         xprt->resvport = 1;
 308         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 309                 xprt->resvport = 0;
 310
 311         clnt = rpc_new_client(args, xprt);
 312         if (IS_ERR(clnt))
 313                 return clnt;
 314
 315         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 316                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 317                 if (err != 0) {
 318                         rpc_shutdown_client(clnt);
 319                         return ERR_PTR(err);
 320                 }
 321         }
 322
 323         clnt->cl_softrtry = 1;
 324         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 325                 clnt->cl_softrtry = 0;
 326
 327         if (args->flags & RPC_CLNT_CREATE_INTR)
 328                 clnt->cl_intr = 1;
 329         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 330                 clnt->cl_autobind = 1;
 331         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 332                 clnt->cl_discrtry = 1;
 333
 334         return clnt;
 335 }
 336 EXPORT_SYMBOL_GPL(rpc_create);
 337
 338 /*
 339  * This function clones the RPC client structure. It allows us to share the
 340  * same transport while varying parameters such as the authentication
 341  * flavour.
 342  */
 343 struct rpc_clnt *
 344 rpc_clone_client(struct rpc_clnt *clnt)
 345 {
 346         struct rpc_clnt *new;
 347         int err = -ENOMEM;
 348
 349         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 350         if (!new)
 351                 goto out_no_clnt;
 352         new->cl_parent = clnt;
 353         /* Turn off autobind on clones */
 354         new->cl_autobind = 0;
 355         INIT_LIST_HEAD(&new->cl_tasks);
 356         spin_lock_init(&new->cl_lock);
 357         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 358         new->cl_metrics = rpc_alloc_iostats(clnt);
 359         if (new->cl_metrics == NULL)
 360                 goto out_no_stats;
 361         kref_init(&new->cl_kref);
 362         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 363         if (err != 0)
 364                 goto out_no_path;
 365         if (new->cl_auth)
 366                 atomic_inc(&new->cl_auth->au_count);
 367         xprt_get(clnt->cl_xprt);
 368         kref_get(&clnt->cl_kref);
 369         rpc_register_client(new);
 370         rpciod_up();
 371         return new;
 372 out_no_path:
 373         rpc_free_iostats(new->cl_metrics);
 374 out_no_stats:
 375         kfree(new);
 376 out_no_clnt:
 377         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 378         return ERR_PTR(err);
 379 }
 380 EXPORT_SYMBOL_GPL(rpc_clone_client);
 381
 382 /*
 383  * Properly shut down an RPC client, terminating all outstanding
 384  * requests.
 385  */
 386 void rpc_shutdown_client(struct rpc_clnt *clnt)
 387 {
 388         dprintk("RPC:       shutting down %s client for %s\n",
 389                         clnt->cl_protname, clnt->cl_server);
 390
 391         while (!list_empty(&clnt->cl_tasks)) {
 392                 rpc_killall_tasks(clnt);
 393                 wait_event_timeout(destroy_wait,
 394                         list_empty(&clnt->cl_tasks), 1*HZ);
 395         }
 396
 397         rpc_release_client(clnt);
 398 }
 399 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 400
 401 /*
 402  * Free an RPC client
 403  */
 404 static void
 405 rpc_free_client(struct kref *kref)
 406 {
 407         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 408
 409         dprintk("RPC:       destroying %s client for %s\n",
 410                         clnt->cl_protname, clnt->cl_server);
 411         if (!IS_ERR(clnt->cl_dentry)) {
 412                 rpc_rmdir(clnt->cl_dentry);
 413                 rpc_put_mount();
 414         }
 415         if (clnt->cl_parent != clnt) {
 416                 rpc_release_client(clnt->cl_parent);
 417                 goto out_free;
 418         }
 419         if (clnt->cl_server != clnt->cl_inline_name)
 420                 kfree(clnt->cl_server);
 421 out_free:
 422         rpc_unregister_client(clnt);
 423         rpc_free_iostats(clnt->cl_metrics);
 424         clnt->cl_metrics = NULL;
 425         xprt_put(clnt->cl_xprt);
 426         rpciod_down();
 427         kfree(clnt);
 428 }
 429
 430 /*
 431  * Free an RPC client
 432  */
 433 static void
 434 rpc_free_auth(struct kref *kref)
 435 {
 436         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 437
 438         if (clnt->cl_auth == NULL) {
 439                 rpc_free_client(kref);
 440                 return;
 441         }
 442
 443         /*
 444          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 445          *       release remaining GSS contexts. This mechanism ensures
 446          *       that it can do so safely.
 447          */
 448         kref_init(kref);
 449         rpcauth_release(clnt->cl_auth);
 450         clnt->cl_auth = NULL;
 451         kref_put(kref, rpc_free_client);
 452 }
 453
 454 /*
 455  * Release reference to the RPC client
 456  */
 457 void
 458 rpc_release_client(struct rpc_clnt *clnt)
 459 {
 460         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 461
 462         if (list_empty(&clnt->cl_tasks))
 463                 wake_up(&destroy_wait);
 464         kref_put(&clnt->cl_kref, rpc_free_auth);
 465 }
 466
 467 /**
 468  * rpc_bind_new_program - bind a new RPC program to an existing client
 469  * @old - old rpc_client
 470  * @program - rpc program to set
 471  * @vers - rpc program version
 472  *
 473  * Clones the rpc client and sets up a new RPC program. This is mainly
 474  * of use for enabling different RPC programs to share the same transport.
 475  * The Sun NFSv2/v3 ACL protocol can do this.
 476  */
 477 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 478                                       struct rpc_program *program,
 479                                       u32 vers)
 480 {
 481         struct rpc_clnt *clnt;
 482         struct rpc_version *version;
 483         int err;
 484
 485         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 486         version = program->version[vers];
 487         clnt = rpc_clone_client(old);
 488         if (IS_ERR(clnt))
 489                 goto out;
 490         clnt->cl_procinfo = version->procs;
 491         clnt->cl_maxproc  = version->nrprocs;
 492         clnt->cl_protname = program->name;
 493         clnt->cl_prog     = program->number;
 494         clnt->cl_vers     = version->number;
 495         clnt->cl_stats    = program->stats;
 496         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 497         if (err != 0) {
 498                 rpc_shutdown_client(clnt);
 499                 clnt = ERR_PTR(err);
 500         }
 501 out:
 502         return clnt;
 503 }
 504 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 505
 506 /*
 507  * Default callback for async RPC calls
 508  */
 509 static void
 510 rpc_default_callback(struct rpc_task *task, void *data)
 511 {
 512 }
 513
 514 static const struct rpc_call_ops rpc_default_ops = {
 515         .rpc_call_done = rpc_default_callback,
 516 };
 517
 518 /*
 519  *      Export the signal mask handling for synchronous code that
 520  *      sleeps on RPC calls
 521  */
 522 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 523
 524 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 525 {
 526         unsigned long   sigallow = sigmask(SIGKILL);
 527         sigset_t sigmask;
 528
 529         /* Block all signals except those listed in sigallow */
 530         if (intr)
 531                 sigallow |= RPC_INTR_SIGNALS;
 532         siginitsetinv(&sigmask, sigallow);
 533         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 534 }
 535
 536 static void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 537 {
 538         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 539 }
 540
 541 static void rpc_restore_sigmask(sigset_t *oldset)
 542 {
 543         sigprocmask(SIG_SETMASK, oldset, NULL);
 544 }
 545
 546 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 547 {
 548         rpc_save_sigmask(oldset, clnt->cl_intr);
 549 }
 550 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 551
 552 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 553 {
 554         rpc_restore_sigmask(oldset);
 555 }
 556 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 557
 558 /**
 559  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 560  * @task_setup_data: pointer to task initialisation data
 561  */
 562 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 563 {
 564         struct rpc_task *task, *ret;
 565         sigset_t oldset;
 566
 567         task = rpc_new_task(task_setup_data);
 568         if (task == NULL) {
 569                 rpc_release_calldata(task_setup_data->callback_ops,
 570                                 task_setup_data->callback_data);
 571                 ret = ERR_PTR(-ENOMEM);
 572                 goto out;
 573         }
 574
 575         if (task->tk_status != 0) {
 576                 ret = ERR_PTR(task->tk_status);
 577                 rpc_put_task(task);
 578                 goto out;
 579         }
 580         atomic_inc(&task->tk_count);
 581         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 582         rpc_task_sigmask(task, &oldset);
 583         rpc_execute(task);
 584         rpc_restore_sigmask(&oldset);
 585         ret = task;
 586 out:
 587         return ret;
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_run_task);
 590
 591 /**
 592  * rpc_call_sync - Perform a synchronous RPC call
 593  * @clnt: pointer to RPC client
 594  * @msg: RPC call parameters
 595  * @flags: RPC call flags
 596  */
 597 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 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 = &rpc_default_ops,
 604                 .flags = flags,
 605         };
 606         int status;
 607
 608         BUG_ON(flags & RPC_TASK_ASYNC);
 609
 610         task = rpc_run_task(&task_setup_data);
 611         if (IS_ERR(task))
 612                 return PTR_ERR(task);
 613         status = task->tk_status;
 614         rpc_put_task(task);
 615         return status;
 616 }
 617 EXPORT_SYMBOL_GPL(rpc_call_sync);
 618
 619 /**
 620  * rpc_call_async - Perform an asynchronous RPC call
 621  * @clnt: pointer to RPC client
 622  * @msg: RPC call parameters
 623  * @flags: RPC call flags
 624  * @ops: RPC call ops
 625  * @data: user call data
 626  */
 627 int
 628 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 629                const struct rpc_call_ops *tk_ops, void *data)
 630 {
 631         struct rpc_task *task;
 632         struct rpc_task_setup task_setup_data = {
 633                 .rpc_client = clnt,
 634                 .rpc_message = msg,
 635                 .callback_ops = tk_ops,
 636                 .callback_data = data,
 637                 .flags = flags|RPC_TASK_ASYNC,
 638         };
 639
 640         task = rpc_run_task(&task_setup_data);
 641         if (IS_ERR(task))
 642                 return PTR_ERR(task);
 643         rpc_put_task(task);
 644         return 0;
 645 }
 646 EXPORT_SYMBOL_GPL(rpc_call_async);
 647
 648 void
 649 rpc_call_start(struct rpc_task *task)
 650 {
 651         task->tk_action = call_start;
 652 }
 653 EXPORT_SYMBOL_GPL(rpc_call_start);
 654
 655 /**
 656  * rpc_peeraddr - extract remote peer address from clnt's xprt
 657  * @clnt: RPC client structure
 658  * @buf: target buffer
 659  * @size: length of target buffer
 660  *
 661  * Returns the number of bytes that are actually in the stored address.
 662  */
 663 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 664 {
 665         size_t bytes;
 666         struct rpc_xprt *xprt = clnt->cl_xprt;
 667
 668         bytes = sizeof(xprt->addr);
 669         if (bytes > bufsize)
 670                 bytes = bufsize;
 671         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 672         return xprt->addrlen;
 673 }
 674 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 675
 676 /**
 677  * rpc_peeraddr2str - return remote peer address in printable format
 678  * @clnt: RPC client structure
 679  * @format: address format
 680  *
 681  */
 682 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 683                              enum rpc_display_format_t format)
 684 {
 685         struct rpc_xprt *xprt = clnt->cl_xprt;
 686
 687         if (xprt->address_strings[format] != NULL)
 688                 return xprt->address_strings[format];
 689         else
 690                 return "unprintable";
 691 }
 692 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 693
 694 void
 695 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 696 {
 697         struct rpc_xprt *xprt = clnt->cl_xprt;
 698         if (xprt->ops->set_buffer_size)
 699                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 700 }
 701 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 702
 703 /*
 704  * Return size of largest payload RPC client can support, in bytes
 705  *
 706  * For stream transports, this is one RPC record fragment (see RFC
 707  * 1831), as we don't support multi-record requests yet.  For datagram
 708  * transports, this is the size of an IP packet minus the IP, UDP, and
 709  * RPC header sizes.
 710  */
 711 size_t rpc_max_payload(struct rpc_clnt *clnt)
 712 {
 713         return clnt->cl_xprt->max_payload;
 714 }
 715 EXPORT_SYMBOL_GPL(rpc_max_payload);
 716
 717 /**
 718  * rpc_force_rebind - force transport to check that remote port is unchanged
 719  * @clnt: client to rebind
 720  *
 721  */
 722 void rpc_force_rebind(struct rpc_clnt *clnt)
 723 {
 724         if (clnt->cl_autobind)
 725                 xprt_clear_bound(clnt->cl_xprt);
 726 }
 727 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 728
 729 /*
 730  * Restart an (async) RPC call. Usually called from within the
 731  * exit handler.
 732  */
 733 void
 734 rpc_restart_call(struct rpc_task *task)
 735 {
 736         if (RPC_ASSASSINATED(task))
 737                 return;
 738
 739         task->tk_action = call_start;
 740 }
 741 EXPORT_SYMBOL_GPL(rpc_restart_call);
 742
 743 /*
 744  * 0.  Initial state
 745  *
 746  *     Other FSM states can be visited zero or more times, but
 747  *     this state is visited exactly once for each RPC.
 748  */
 749 static void
 750 call_start(struct rpc_task *task)
 751 {
 752         struct rpc_clnt *clnt = task->tk_client;
 753
 754         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 755                         clnt->cl_protname, clnt->cl_vers,
 756                         task->tk_msg.rpc_proc->p_proc,
 757                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 758
 759         /* Increment call count */
 760         task->tk_msg.rpc_proc->p_count++;
 761         clnt->cl_stats->rpccnt++;
 762         task->tk_action = call_reserve;
 763 }
 764
 765 /*
 766  * 1.   Reserve an RPC call slot
 767  */
 768 static void
 769 call_reserve(struct rpc_task *task)
 770 {
 771         dprint_status(task);
 772
 773         if (!rpcauth_uptodatecred(task)) {
 774                 task->tk_action = call_refresh;
 775                 return;
 776         }
 777
 778         task->tk_status  = 0;
 779         task->tk_action  = call_reserveresult;
 780         xprt_reserve(task);
 781 }
 782
 783 /*
 784  * 1b.  Grok the result of xprt_reserve()
 785  */
 786 static void
 787 call_reserveresult(struct rpc_task *task)
 788 {
 789         int status = task->tk_status;
 790
 791         dprint_status(task);
 792
 793         /*
 794          * After a call to xprt_reserve(), we must have either
 795          * a request slot or else an error status.
 796          */
 797         task->tk_status = 0;
 798         if (status >= 0) {
 799                 if (task->tk_rqstp) {
 800                         task->tk_action = call_allocate;
 801                         return;
 802                 }
 803
 804                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 805                                 __FUNCTION__, status);
 806                 rpc_exit(task, -EIO);
 807                 return;
 808         }
 809
 810         /*
 811          * Even though there was an error, we may have acquired
 812          * a request slot somehow.  Make sure not to leak it.
 813          */
 814         if (task->tk_rqstp) {
 815                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 816                                 __FUNCTION__, status);
 817                 xprt_release(task);
 818         }
 819
 820         switch (status) {
 821         case -EAGAIN:   /* woken up; retry */
 822                 task->tk_action = call_reserve;
 823                 return;
 824         case -EIO:      /* probably a shutdown */
 825                 break;
 826         default:
 827                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 828                                 __FUNCTION__, status);
 829                 break;
 830         }
 831         rpc_exit(task, status);
 832 }
 833
 834 /*
 835  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 836  *      (Note: buffer memory is freed in xprt_release).
 837  */
 838 static void
 839 call_allocate(struct rpc_task *task)
 840 {
 841         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 842         struct rpc_rqst *req = task->tk_rqstp;
 843         struct rpc_xprt *xprt = task->tk_xprt;
 844         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 845
 846         dprint_status(task);
 847
 848         task->tk_status = 0;
 849         task->tk_action = call_bind;
 850
 851         if (req->rq_buffer)
 852                 return;
 853
 854         if (proc->p_proc != 0) {
 855                 BUG_ON(proc->p_arglen == 0);
 856                 if (proc->p_decode != NULL)
 857                         BUG_ON(proc->p_replen == 0);
 858         }
 859
 860         /*
 861          * Calculate the size (in quads) of the RPC call
 862          * and reply headers, and convert both values
 863          * to byte sizes.
 864          */
 865         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 866         req->rq_callsize <<= 2;
 867         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 868         req->rq_rcvsize <<= 2;
 869
 870         req->rq_buffer = xprt->ops->buf_alloc(task,
 871                                         req->rq_callsize + req->rq_rcvsize);
 872         if (req->rq_buffer != NULL)
 873                 return;
 874
 875         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 876
 877         if (RPC_IS_ASYNC(task) || !signalled()) {
 878                 task->tk_action = call_allocate;
 879                 rpc_delay(task, HZ>>4);
 880                 return;
 881         }
 882
 883         rpc_exit(task, -ERESTARTSYS);
 884 }
 885
 886 static inline int
 887 rpc_task_need_encode(struct rpc_task *task)
 888 {
 889         return task->tk_rqstp->rq_snd_buf.len == 0;
 890 }
 891
 892 static inline void
 893 rpc_task_force_reencode(struct rpc_task *task)
 894 {
 895         task->tk_rqstp->rq_snd_buf.len = 0;
 896 }
 897
 898 static inline void
 899 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 900 {
 901         buf->head[0].iov_base = start;
 902         buf->head[0].iov_len = len;
 903         buf->tail[0].iov_len = 0;
 904         buf->page_len = 0;
 905         buf->flags = 0;
 906         buf->len = 0;
 907         buf->buflen = len;
 908 }
 909
 910 /*
 911  * 3.   Encode arguments of an RPC call
 912  */
 913 static void
 914 call_encode(struct rpc_task *task)
 915 {
 916         struct rpc_rqst *req = task->tk_rqstp;
 917         kxdrproc_t      encode;
 918         __be32          *p;
 919
 920         dprint_status(task);
 921
 922         rpc_xdr_buf_init(&req->rq_snd_buf,
 923                          req->rq_buffer,
 924                          req->rq_callsize);
 925         rpc_xdr_buf_init(&req->rq_rcv_buf,
 926                          (char *)req->rq_buffer + req->rq_callsize,
 927                          req->rq_rcvsize);
 928
 929         /* Encode header and provided arguments */
 930         encode = task->tk_msg.rpc_proc->p_encode;
 931         if (!(p = call_header(task))) {
 932                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 933                 rpc_exit(task, -EIO);
 934                 return;
 935         }
 936         if (encode == NULL)
 937                 return;
 938
 939         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 940                         task->tk_msg.rpc_argp);
 941         if (task->tk_status == -ENOMEM) {
 942                 /* XXX: Is this sane? */
 943                 rpc_delay(task, 3*HZ);
 944                 task->tk_status = -EAGAIN;
 945         }
 946 }
 947
 948 /*
 949  * 4.   Get the server port number if not yet set
 950  */
 951 static void
 952 call_bind(struct rpc_task *task)
 953 {
 954         struct rpc_xprt *xprt = task->tk_xprt;
 955
 956         dprint_status(task);
 957
 958         task->tk_action = call_connect;
 959         if (!xprt_bound(xprt)) {
 960                 task->tk_action = call_bind_status;
 961                 task->tk_timeout = xprt->bind_timeout;
 962                 xprt->ops->rpcbind(task);
 963         }
 964 }
 965
 966 /*
 967  * 4a.  Sort out bind result
 968  */
 969 static void
 970 call_bind_status(struct rpc_task *task)
 971 {
 972         int status = -EIO;
 973
 974         if (task->tk_status >= 0) {
 975                 dprint_status(task);
 976                 task->tk_status = 0;
 977                 task->tk_action = call_connect;
 978                 return;
 979         }
 980
 981         switch (task->tk_status) {
 982         case -EAGAIN:
 983                 dprintk("RPC: %5u rpcbind waiting for another request "
 984                                 "to finish\n", task->tk_pid);
 985                 /* avoid busy-waiting here -- could be a network outage. */
 986                 rpc_delay(task, 5*HZ);
 987                 goto retry_timeout;
 988         case -EACCES:
 989                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 990                                 "unavailable\n", task->tk_pid);
 991                 /* fail immediately if this is an RPC ping */
 992                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 993                         status = -EOPNOTSUPP;
 994                         break;
 995                 }
 996                 rpc_delay(task, 3*HZ);
 997                 goto retry_timeout;
 998         case -ETIMEDOUT:
 999                 dprintk("RPC: %5u rpcbind request timed out\n",
1000                                 task->tk_pid);
1001                 goto retry_timeout;
1002         case -EPFNOSUPPORT:
1003                 /* server doesn't support any rpcbind version we know of */
1004                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1005                                 task->tk_pid);
1006                 break;
1007         case -EPROTONOSUPPORT:
1008                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1009                                 task->tk_pid);
1010                 task->tk_status = 0;
1011                 task->tk_action = call_bind;
1012                 return;
1013         default:
1014                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1015                                 task->tk_pid, -task->tk_status);
1016         }
1017
1018         rpc_exit(task, status);
1019         return;
1020
1021 retry_timeout:
1022         task->tk_action = call_timeout;
1023 }
1024
1025 /*
1026  * 4b.  Connect to the RPC server
1027  */
1028 static void
1029 call_connect(struct rpc_task *task)
1030 {
1031         struct rpc_xprt *xprt = task->tk_xprt;
1032
1033         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1034                         task->tk_pid, xprt,
1035                         (xprt_connected(xprt) ? "is" : "is not"));
1036
1037         task->tk_action = call_transmit;
1038         if (!xprt_connected(xprt)) {
1039                 task->tk_action = call_connect_status;
1040                 if (task->tk_status < 0)
1041                         return;
1042                 xprt_connect(task);
1043         }
1044 }
1045
1046 /*
1047  * 4c.  Sort out connect result
1048  */
1049 static void
1050 call_connect_status(struct rpc_task *task)
1051 {
1052         struct rpc_clnt *clnt = task->tk_client;
1053         int status = task->tk_status;
1054
1055         dprint_status(task);
1056
1057         task->tk_status = 0;
1058         if (status >= 0) {
1059                 clnt->cl_stats->netreconn++;
1060                 task->tk_action = call_transmit;
1061                 return;
1062         }
1063
1064         /* Something failed: remote service port may have changed */
1065         rpc_force_rebind(clnt);
1066
1067         switch (status) {
1068         case -ENOTCONN:
1069         case -EAGAIN:
1070                 task->tk_action = call_bind;
1071                 if (!RPC_IS_SOFT(task))
1072                         return;
1073                 /* if soft mounted, test if we've timed out */
1074         case -ETIMEDOUT:
1075                 task->tk_action = call_timeout;
1076                 return;
1077         }
1078         rpc_exit(task, -EIO);
1079 }
1080
1081 /*
1082  * 5.   Transmit the RPC request, and wait for reply
1083  */
1084 static void
1085 call_transmit(struct rpc_task *task)
1086 {
1087         dprint_status(task);
1088
1089         task->tk_action = call_status;
1090         if (task->tk_status < 0)
1091                 return;
1092         task->tk_status = xprt_prepare_transmit(task);
1093         if (task->tk_status != 0)
1094                 return;
1095         task->tk_action = call_transmit_status;
1096         /* Encode here so that rpcsec_gss can use correct sequence number. */
1097         if (rpc_task_need_encode(task)) {
1098                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1099                 call_encode(task);
1100                 /* Did the encode result in an error condition? */
1101                 if (task->tk_status != 0)
1102                         return;
1103         }
1104         xprt_transmit(task);
1105         if (task->tk_status < 0)
1106                 return;
1107         /*
1108          * On success, ensure that we call xprt_end_transmit() before sleeping
1109          * in order to allow access to the socket to other RPC requests.
1110          */
1111         call_transmit_status(task);
1112         if (task->tk_msg.rpc_proc->p_decode != NULL)
1113                 return;
1114         task->tk_action = rpc_exit_task;
1115         rpc_wake_up_task(task);
1116 }
1117
1118 /*
1119  * 5a.  Handle cleanup after a transmission
1120  */
1121 static void
1122 call_transmit_status(struct rpc_task *task)
1123 {
1124         task->tk_action = call_status;
1125         /*
1126          * Special case: if we've been waiting on the socket's write_space()
1127          * callback, then don't call xprt_end_transmit().
1128          */
1129         if (task->tk_status == -EAGAIN)
1130                 return;
1131         xprt_end_transmit(task);
1132         rpc_task_force_reencode(task);
1133 }
1134
1135 /*
1136  * 6.   Sort out the RPC call status
1137  */
1138 static void
1139 call_status(struct rpc_task *task)
1140 {
1141         struct rpc_clnt *clnt = task->tk_client;
1142         struct rpc_rqst *req = task->tk_rqstp;
1143         int             status;
1144
1145         if (req->rq_received > 0 && !req->rq_bytes_sent)
1146                 task->tk_status = req->rq_received;
1147
1148         dprint_status(task);
1149
1150         status = task->tk_status;
1151         if (status >= 0) {
1152                 task->tk_action = call_decode;
1153                 return;
1154         }
1155
1156         task->tk_status = 0;
1157         switch(status) {
1158         case -EHOSTDOWN:
1159         case -EHOSTUNREACH:
1160         case -ENETUNREACH:
1161                 /*
1162                  * Delay any retries for 3 seconds, then handle as if it
1163                  * were a timeout.
1164                  */
1165                 rpc_delay(task, 3*HZ);
1166         case -ETIMEDOUT:
1167                 task->tk_action = call_timeout;
1168                 if (task->tk_client->cl_discrtry)
1169                         xprt_force_disconnect(task->tk_xprt);
1170                 break;
1171         case -ECONNREFUSED:
1172         case -ENOTCONN:
1173                 rpc_force_rebind(clnt);
1174                 task->tk_action = call_bind;
1175                 break;
1176         case -EAGAIN:
1177                 task->tk_action = call_transmit;
1178                 break;
1179         case -EIO:
1180                 /* shutdown or soft timeout */
1181                 rpc_exit(task, status);
1182                 break;
1183         default:
1184                 printk("%s: RPC call returned error %d\n",
1185                                clnt->cl_protname, -status);
1186                 rpc_exit(task, status);
1187         }
1188 }
1189
1190 /*
1191  * 6a.  Handle RPC timeout
1192  *      We do not release the request slot, so we keep using the
1193  *      same XID for all retransmits.
1194  */
1195 static void
1196 call_timeout(struct rpc_task *task)
1197 {
1198         struct rpc_clnt *clnt = task->tk_client;
1199
1200         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1201                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1202                 goto retry;
1203         }
1204
1205         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1206         task->tk_timeouts++;
1207
1208         if (RPC_IS_SOFT(task)) {
1209                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1210                                 clnt->cl_protname, clnt->cl_server);
1211                 rpc_exit(task, -EIO);
1212                 return;
1213         }
1214
1215         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1216                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1217                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1218                         clnt->cl_protname, clnt->cl_server);
1219         }
1220         rpc_force_rebind(clnt);
1221
1222 retry:
1223         clnt->cl_stats->rpcretrans++;
1224         task->tk_action = call_bind;
1225         task->tk_status = 0;
1226 }
1227
1228 /*
1229  * 7.   Decode the RPC reply
1230  */
1231 static void
1232 call_decode(struct rpc_task *task)
1233 {
1234         struct rpc_clnt *clnt = task->tk_client;
1235         struct rpc_rqst *req = task->tk_rqstp;
1236         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1237         __be32          *p;
1238
1239         dprintk("RPC: %5u call_decode (status %d)\n",
1240                         task->tk_pid, task->tk_status);
1241
1242         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1243                 printk(KERN_NOTICE "%s: server %s OK\n",
1244                         clnt->cl_protname, clnt->cl_server);
1245                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1246         }
1247
1248         if (task->tk_status < 12) {
1249                 if (!RPC_IS_SOFT(task)) {
1250                         task->tk_action = call_bind;
1251                         clnt->cl_stats->rpcretrans++;
1252                         goto out_retry;
1253                 }
1254                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1255                                 clnt->cl_protname, task->tk_status);
1256                 task->tk_action = call_timeout;
1257                 goto out_retry;
1258         }
1259
1260         /*
1261          * Ensure that we see all writes made by xprt_complete_rqst()
1262          * before it changed req->rq_received.
1263          */
1264         smp_rmb();
1265         req->rq_rcv_buf.len = req->rq_private_buf.len;
1266
1267         /* Check that the softirq receive buffer is valid */
1268         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1269                                 sizeof(req->rq_rcv_buf)) != 0);
1270
1271         /* Verify the RPC header */
1272         p = call_verify(task);
1273         if (IS_ERR(p)) {
1274                 if (p == ERR_PTR(-EAGAIN))
1275                         goto out_retry;
1276                 return;
1277         }
1278
1279         task->tk_action = rpc_exit_task;
1280
1281         if (decode) {
1282                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1283                                                       task->tk_msg.rpc_resp);
1284         }
1285         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1286                         task->tk_status);
1287         return;
1288 out_retry:
1289         req->rq_received = req->rq_private_buf.len = 0;
1290         task->tk_status = 0;
1291         if (task->tk_client->cl_discrtry)
1292                 xprt_force_disconnect(task->tk_xprt);
1293 }
1294
1295 /*
1296  * 8.   Refresh the credentials if rejected by the server
1297  */
1298 static void
1299 call_refresh(struct rpc_task *task)
1300 {
1301         dprint_status(task);
1302
1303         task->tk_action = call_refreshresult;
1304         task->tk_status = 0;
1305         task->tk_client->cl_stats->rpcauthrefresh++;
1306         rpcauth_refreshcred(task);
1307 }
1308
1309 /*
1310  * 8a.  Process the results of a credential refresh
1311  */
1312 static void
1313 call_refreshresult(struct rpc_task *task)
1314 {
1315         int status = task->tk_status;
1316
1317         dprint_status(task);
1318
1319         task->tk_status = 0;
1320         task->tk_action = call_reserve;
1321         if (status >= 0 && rpcauth_uptodatecred(task))
1322                 return;
1323         if (status == -EACCES) {
1324                 rpc_exit(task, -EACCES);
1325                 return;
1326         }
1327         task->tk_action = call_refresh;
1328         if (status != -ETIMEDOUT)
1329                 rpc_delay(task, 3*HZ);
1330         return;
1331 }
1332
1333 /*
1334  * Call header serialization
1335  */
1336 static __be32 *
1337 call_header(struct rpc_task *task)
1338 {
1339         struct rpc_clnt *clnt = task->tk_client;
1340         struct rpc_rqst *req = task->tk_rqstp;
1341         __be32          *p = req->rq_svec[0].iov_base;
1342
1343         /* FIXME: check buffer size? */
1344
1345         p = xprt_skip_transport_header(task->tk_xprt, p);
1346         *p++ = req->rq_xid;             /* XID */
1347         *p++ = htonl(RPC_CALL);         /* CALL */
1348         *p++ = htonl(RPC_VERSION);      /* RPC version */
1349         *p++ = htonl(clnt->cl_prog);    /* program number */
1350         *p++ = htonl(clnt->cl_vers);    /* program version */
1351         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1352         p = rpcauth_marshcred(task, p);
1353         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1354         return p;
1355 }
1356
1357 /*
1358  * Reply header verification
1359  */
1360 static __be32 *
1361 call_verify(struct rpc_task *task)
1362 {
1363         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1364         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1365         __be32  *p = iov->iov_base;
1366         u32 n;
1367         int error = -EACCES;
1368
1369         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1370                 /* RFC-1014 says that the representation of XDR data must be a
1371                  * multiple of four bytes
1372                  * - if it isn't pointer subtraction in the NFS client may give
1373                  *   undefined results
1374                  */
1375                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1376                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1377                        task->tk_rqstp->rq_rcv_buf.len);
1378                 goto out_eio;
1379         }
1380         if ((len -= 3) < 0)
1381                 goto out_overflow;
1382         p += 1; /* skip XID */
1383
1384         if ((n = ntohl(*p++)) != RPC_REPLY) {
1385                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1386                                 task->tk_pid, __FUNCTION__, n);
1387                 goto out_garbage;
1388         }
1389         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1390                 if (--len < 0)
1391                         goto out_overflow;
1392                 switch ((n = ntohl(*p++))) {
1393                         case RPC_AUTH_ERROR:
1394                                 break;
1395                         case RPC_MISMATCH:
1396                                 dprintk("RPC: %5u %s: RPC call version "
1397                                                 "mismatch!\n",
1398                                                 task->tk_pid, __FUNCTION__);
1399                                 error = -EPROTONOSUPPORT;
1400                                 goto out_err;
1401                         default:
1402                                 dprintk("RPC: %5u %s: RPC call rejected, "
1403                                                 "unknown error: %x\n",
1404                                                 task->tk_pid, __FUNCTION__, n);
1405                                 goto out_eio;
1406                 }
1407                 if (--len < 0)
1408                         goto out_overflow;
1409                 switch ((n = ntohl(*p++))) {
1410                 case RPC_AUTH_REJECTEDCRED:
1411                 case RPC_AUTH_REJECTEDVERF:
1412                 case RPCSEC_GSS_CREDPROBLEM:
1413                 case RPCSEC_GSS_CTXPROBLEM:
1414                         if (!task->tk_cred_retry)
1415                                 break;
1416                         task->tk_cred_retry--;
1417                         dprintk("RPC: %5u %s: retry stale creds\n",
1418                                         task->tk_pid, __FUNCTION__);
1419                         rpcauth_invalcred(task);
1420                         /* Ensure we obtain a new XID! */
1421                         xprt_release(task);
1422                         task->tk_action = call_refresh;
1423                         goto out_retry;
1424                 case RPC_AUTH_BADCRED:
1425                 case RPC_AUTH_BADVERF:
1426                         /* possibly garbled cred/verf? */
1427                         if (!task->tk_garb_retry)
1428                                 break;
1429                         task->tk_garb_retry--;
1430                         dprintk("RPC: %5u %s: retry garbled creds\n",
1431                                         task->tk_pid, __FUNCTION__);
1432                         task->tk_action = call_bind;
1433                         goto out_retry;
1434                 case RPC_AUTH_TOOWEAK:
1435                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1436                                "authentication.\n", task->tk_client->cl_server);
1437                         break;
1438                 default:
1439                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1440                                         task->tk_pid, __FUNCTION__, n);
1441                         error = -EIO;
1442                 }
1443                 dprintk("RPC: %5u %s: call rejected %d\n",
1444                                 task->tk_pid, __FUNCTION__, n);
1445                 goto out_err;
1446         }
1447         if (!(p = rpcauth_checkverf(task, p))) {
1448                 dprintk("RPC: %5u %s: auth check failed\n",
1449                                 task->tk_pid, __FUNCTION__);
1450                 goto out_garbage;               /* bad verifier, retry */
1451         }
1452         len = p - (__be32 *)iov->iov_base - 1;
1453         if (len < 0)
1454                 goto out_overflow;
1455         switch ((n = ntohl(*p++))) {
1456         case RPC_SUCCESS:
1457                 return p;
1458         case RPC_PROG_UNAVAIL:
1459                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1460                                 task->tk_pid, __FUNCTION__,
1461                                 (unsigned int)task->tk_client->cl_prog,
1462                                 task->tk_client->cl_server);
1463                 error = -EPFNOSUPPORT;
1464                 goto out_err;
1465         case RPC_PROG_MISMATCH:
1466                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1467                                 "server %s\n", task->tk_pid, __FUNCTION__,
1468                                 (unsigned int)task->tk_client->cl_prog,
1469                                 (unsigned int)task->tk_client->cl_vers,
1470                                 task->tk_client->cl_server);
1471                 error = -EPROTONOSUPPORT;
1472                 goto out_err;
1473         case RPC_PROC_UNAVAIL:
1474                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1475                                 "version %u on server %s\n",
1476                                 task->tk_pid, __FUNCTION__,
1477                                 task->tk_msg.rpc_proc,
1478                                 task->tk_client->cl_prog,
1479                                 task->tk_client->cl_vers,
1480                                 task->tk_client->cl_server);
1481                 error = -EOPNOTSUPP;
1482                 goto out_err;
1483         case RPC_GARBAGE_ARGS:
1484                 dprintk("RPC: %5u %s: server saw garbage\n",
1485                                 task->tk_pid, __FUNCTION__);
1486                 break;                  /* retry */
1487         default:
1488                 dprintk("RPC: %5u %s: server accept status: %x\n",
1489                                 task->tk_pid, __FUNCTION__, n);
1490                 /* Also retry */
1491         }
1492
1493 out_garbage:
1494         task->tk_client->cl_stats->rpcgarbage++;
1495         if (task->tk_garb_retry) {
1496                 task->tk_garb_retry--;
1497                 dprintk("RPC: %5u %s: retrying\n",
1498                                 task->tk_pid, __FUNCTION__);
1499                 task->tk_action = call_bind;
1500 out_retry:
1501                 return ERR_PTR(-EAGAIN);
1502         }
1503 out_eio:
1504         error = -EIO;
1505 out_err:
1506         rpc_exit(task, error);
1507         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1508                         __FUNCTION__, error);
1509         return ERR_PTR(error);
1510 out_overflow:
1511         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1512                         __FUNCTION__);
1513         goto out_garbage;
1514 }
1515
1516 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1517 {
1518         return 0;
1519 }
1520
1521 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1522 {
1523         return 0;
1524 }
1525
1526 static struct rpc_procinfo rpcproc_null = {
1527         .p_encode = rpcproc_encode_null,
1528         .p_decode = rpcproc_decode_null,
1529 };
1530
1531 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1532 {
1533         struct rpc_message msg = {
1534                 .rpc_proc = &rpcproc_null,
1535         };
1536         int err;
1537         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1538         err = rpc_call_sync(clnt, &msg, flags);
1539         put_rpccred(msg.rpc_cred);
1540         return err;
1541 }
1542
1543 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1544 {
1545         struct rpc_message msg = {
1546                 .rpc_proc = &rpcproc_null,
1547                 .rpc_cred = cred,
1548         };
1549         struct rpc_task_setup task_setup_data = {
1550                 .rpc_client = clnt,
1551                 .rpc_message = &msg,
1552                 .callback_ops = &rpc_default_ops,
1553                 .flags = flags,
1554         };
1555         return rpc_run_task(&task_setup_data);
1556 }
1557 EXPORT_SYMBOL_GPL(rpc_call_null);
1558
1559 #ifdef RPC_DEBUG
1560 void rpc_show_tasks(void)
1561 {
1562         struct rpc_clnt *clnt;
1563         struct rpc_task *t;
1564
1565         spin_lock(&rpc_client_lock);
1566         if (list_empty(&all_clients))
1567                 goto out;
1568         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1569                 "-rpcwait -action- ---ops--\n");
1570         list_for_each_entry(clnt, &all_clients, cl_clients) {
1571                 if (list_empty(&clnt->cl_tasks))
1572                         continue;
1573                 spin_lock(&clnt->cl_lock);
1574                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1575                         const char *rpc_waitq = "none";
1576                         int proc;
1577
1578                         if (t->tk_msg.rpc_proc)
1579                                 proc = t->tk_msg.rpc_proc->p_proc;
1580                         else
1581                                 proc = -1;
1582
1583                         if (RPC_IS_QUEUED(t))
1584                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1585
1586                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1587                                 t->tk_pid, proc,
1588                                 t->tk_flags, t->tk_status,
1589                                 t->tk_client,
1590                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1591                                 t->tk_rqstp, t->tk_timeout,
1592                                 rpc_waitq,
1593                                 t->tk_action, t->tk_ops);
1594                 }
1595                 spin_unlock(&clnt->cl_lock);
1596         }
1597 out:
1598         spin_unlock(&rpc_client_lock);
1599 }
1600 #endif