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_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 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 683 {
 684         struct rpc_xprt *xprt = clnt->cl_xprt;
 685
 686         if (xprt->address_strings[format] != NULL)
 687                 return xprt->address_strings[format];
 688         else
 689                 return "unprintable";
 690 }
 691 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 692
 693 void
 694 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 695 {
 696         struct rpc_xprt *xprt = clnt->cl_xprt;
 697         if (xprt->ops->set_buffer_size)
 698                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 699 }
 700 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 701
 702 /*
 703  * Return size of largest payload RPC client can support, in bytes
 704  *
 705  * For stream transports, this is one RPC record fragment (see RFC
 706  * 1831), as we don't support multi-record requests yet.  For datagram
 707  * transports, this is the size of an IP packet minus the IP, UDP, and
 708  * RPC header sizes.
 709  */
 710 size_t rpc_max_payload(struct rpc_clnt *clnt)
 711 {
 712         return clnt->cl_xprt->max_payload;
 713 }
 714 EXPORT_SYMBOL_GPL(rpc_max_payload);
 715
 716 /**
 717  * rpc_force_rebind - force transport to check that remote port is unchanged
 718  * @clnt: client to rebind
 719  *
 720  */
 721 void rpc_force_rebind(struct rpc_clnt *clnt)
 722 {
 723         if (clnt->cl_autobind)
 724                 xprt_clear_bound(clnt->cl_xprt);
 725 }
 726 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 727
 728 /*
 729  * Restart an (async) RPC call. Usually called from within the
 730  * exit handler.
 731  */
 732 void
 733 rpc_restart_call(struct rpc_task *task)
 734 {
 735         if (RPC_ASSASSINATED(task))
 736                 return;
 737
 738         task->tk_action = call_start;
 739 }
 740 EXPORT_SYMBOL_GPL(rpc_restart_call);
 741
 742 /*
 743  * 0.  Initial state
 744  *
 745  *     Other FSM states can be visited zero or more times, but
 746  *     this state is visited exactly once for each RPC.
 747  */
 748 static void
 749 call_start(struct rpc_task *task)
 750 {
 751         struct rpc_clnt *clnt = task->tk_client;
 752
 753         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 754                         clnt->cl_protname, clnt->cl_vers,
 755                         task->tk_msg.rpc_proc->p_proc,
 756                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 757
 758         /* Increment call count */
 759         task->tk_msg.rpc_proc->p_count++;
 760         clnt->cl_stats->rpccnt++;
 761         task->tk_action = call_reserve;
 762 }
 763
 764 /*
 765  * 1.   Reserve an RPC call slot
 766  */
 767 static void
 768 call_reserve(struct rpc_task *task)
 769 {
 770         dprint_status(task);
 771
 772         if (!rpcauth_uptodatecred(task)) {
 773                 task->tk_action = call_refresh;
 774                 return;
 775         }
 776
 777         task->tk_status  = 0;
 778         task->tk_action  = call_reserveresult;
 779         xprt_reserve(task);
 780 }
 781
 782 /*
 783  * 1b.  Grok the result of xprt_reserve()
 784  */
 785 static void
 786 call_reserveresult(struct rpc_task *task)
 787 {
 788         int status = task->tk_status;
 789
 790         dprint_status(task);
 791
 792         /*
 793          * After a call to xprt_reserve(), we must have either
 794          * a request slot or else an error status.
 795          */
 796         task->tk_status = 0;
 797         if (status >= 0) {
 798                 if (task->tk_rqstp) {
 799                         task->tk_action = call_allocate;
 800                         return;
 801                 }
 802
 803                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 804                                 __FUNCTION__, status);
 805                 rpc_exit(task, -EIO);
 806                 return;
 807         }
 808
 809         /*
 810          * Even though there was an error, we may have acquired
 811          * a request slot somehow.  Make sure not to leak it.
 812          */
 813         if (task->tk_rqstp) {
 814                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 815                                 __FUNCTION__, status);
 816                 xprt_release(task);
 817         }
 818
 819         switch (status) {
 820         case -EAGAIN:   /* woken up; retry */
 821                 task->tk_action = call_reserve;
 822                 return;
 823         case -EIO:      /* probably a shutdown */
 824                 break;
 825         default:
 826                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 827                                 __FUNCTION__, status);
 828                 break;
 829         }
 830         rpc_exit(task, status);
 831 }
 832
 833 /*
 834  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 835  *      (Note: buffer memory is freed in xprt_release).
 836  */
 837 static void
 838 call_allocate(struct rpc_task *task)
 839 {
 840         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 841         struct rpc_rqst *req = task->tk_rqstp;
 842         struct rpc_xprt *xprt = task->tk_xprt;
 843         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 844
 845         dprint_status(task);
 846
 847         task->tk_status = 0;
 848         task->tk_action = call_bind;
 849
 850         if (req->rq_buffer)
 851                 return;
 852
 853         if (proc->p_proc != 0) {
 854                 BUG_ON(proc->p_arglen == 0);
 855                 if (proc->p_decode != NULL)
 856                         BUG_ON(proc->p_replen == 0);
 857         }
 858
 859         /*
 860          * Calculate the size (in quads) of the RPC call
 861          * and reply headers, and convert both values
 862          * to byte sizes.
 863          */
 864         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 865         req->rq_callsize <<= 2;
 866         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 867         req->rq_rcvsize <<= 2;
 868
 869         req->rq_buffer = xprt->ops->buf_alloc(task,
 870                                         req->rq_callsize + req->rq_rcvsize);
 871         if (req->rq_buffer != NULL)
 872                 return;
 873
 874         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 875
 876         if (RPC_IS_ASYNC(task) || !signalled()) {
 877                 task->tk_action = call_allocate;
 878                 rpc_delay(task, HZ>>4);
 879                 return;
 880         }
 881
 882         rpc_exit(task, -ERESTARTSYS);
 883 }
 884
 885 static inline int
 886 rpc_task_need_encode(struct rpc_task *task)
 887 {
 888         return task->tk_rqstp->rq_snd_buf.len == 0;
 889 }
 890
 891 static inline void
 892 rpc_task_force_reencode(struct rpc_task *task)
 893 {
 894         task->tk_rqstp->rq_snd_buf.len = 0;
 895 }
 896
 897 static inline void
 898 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 899 {
 900         buf->head[0].iov_base = start;
 901         buf->head[0].iov_len = len;
 902         buf->tail[0].iov_len = 0;
 903         buf->page_len = 0;
 904         buf->flags = 0;
 905         buf->len = 0;
 906         buf->buflen = len;
 907 }
 908
 909 /*
 910  * 3.   Encode arguments of an RPC call
 911  */
 912 static void
 913 call_encode(struct rpc_task *task)
 914 {
 915         struct rpc_rqst *req = task->tk_rqstp;
 916         kxdrproc_t      encode;
 917         __be32          *p;
 918
 919         dprint_status(task);
 920
 921         rpc_xdr_buf_init(&req->rq_snd_buf,
 922                          req->rq_buffer,
 923                          req->rq_callsize);
 924         rpc_xdr_buf_init(&req->rq_rcv_buf,
 925                          (char *)req->rq_buffer + req->rq_callsize,
 926                          req->rq_rcvsize);
 927
 928         /* Encode header and provided arguments */
 929         encode = task->tk_msg.rpc_proc->p_encode;
 930         if (!(p = call_header(task))) {
 931                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 932                 rpc_exit(task, -EIO);
 933                 return;
 934         }
 935         if (encode == NULL)
 936                 return;
 937
 938         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 939                         task->tk_msg.rpc_argp);
 940         if (task->tk_status == -ENOMEM) {
 941                 /* XXX: Is this sane? */
 942                 rpc_delay(task, 3*HZ);
 943                 task->tk_status = -EAGAIN;
 944         }
 945 }
 946
 947 /*
 948  * 4.   Get the server port number if not yet set
 949  */
 950 static void
 951 call_bind(struct rpc_task *task)
 952 {
 953         struct rpc_xprt *xprt = task->tk_xprt;
 954
 955         dprint_status(task);
 956
 957         task->tk_action = call_connect;
 958         if (!xprt_bound(xprt)) {
 959                 task->tk_action = call_bind_status;
 960                 task->tk_timeout = xprt->bind_timeout;
 961                 xprt->ops->rpcbind(task);
 962         }
 963 }
 964
 965 /*
 966  * 4a.  Sort out bind result
 967  */
 968 static void
 969 call_bind_status(struct rpc_task *task)
 970 {
 971         int status = -EIO;
 972
 973         if (task->tk_status >= 0) {
 974                 dprint_status(task);
 975                 task->tk_status = 0;
 976                 task->tk_action = call_connect;
 977                 return;
 978         }
 979
 980         switch (task->tk_status) {
 981         case -EAGAIN:
 982                 dprintk("RPC: %5u rpcbind waiting for another request "
 983                                 "to finish\n", task->tk_pid);
 984                 /* avoid busy-waiting here -- could be a network outage. */
 985                 rpc_delay(task, 5*HZ);
 986                 goto retry_timeout;
 987         case -EACCES:
 988                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 989                                 "unavailable\n", task->tk_pid);
 990                 /* fail immediately if this is an RPC ping */
 991                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 992                         status = -EOPNOTSUPP;
 993                         break;
 994                 }
 995                 rpc_delay(task, 3*HZ);
 996                 goto retry_timeout;
 997         case -ETIMEDOUT:
 998                 dprintk("RPC: %5u rpcbind request timed out\n",
 999                                 task->tk_pid);
1000                 goto retry_timeout;
1001         case -EPFNOSUPPORT:
1002                 /* server doesn't support any rpcbind version we know of */
1003                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1004                                 task->tk_pid);
1005                 break;
1006         case -EPROTONOSUPPORT:
1007                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1008                                 task->tk_pid);
1009                 task->tk_status = 0;
1010                 task->tk_action = call_bind;
1011                 return;
1012         default:
1013                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1014                                 task->tk_pid, -task->tk_status);
1015         }
1016
1017         rpc_exit(task, status);
1018         return;
1019
1020 retry_timeout:
1021         task->tk_action = call_timeout;
1022 }
1023
1024 /*
1025  * 4b.  Connect to the RPC server
1026  */
1027 static void
1028 call_connect(struct rpc_task *task)
1029 {
1030         struct rpc_xprt *xprt = task->tk_xprt;
1031
1032         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1033                         task->tk_pid, xprt,
1034                         (xprt_connected(xprt) ? "is" : "is not"));
1035
1036         task->tk_action = call_transmit;
1037         if (!xprt_connected(xprt)) {
1038                 task->tk_action = call_connect_status;
1039                 if (task->tk_status < 0)
1040                         return;
1041                 xprt_connect(task);
1042         }
1043 }
1044
1045 /*
1046  * 4c.  Sort out connect result
1047  */
1048 static void
1049 call_connect_status(struct rpc_task *task)
1050 {
1051         struct rpc_clnt *clnt = task->tk_client;
1052         int status = task->tk_status;
1053
1054         dprint_status(task);
1055
1056         task->tk_status = 0;
1057         if (status >= 0) {
1058                 clnt->cl_stats->netreconn++;
1059                 task->tk_action = call_transmit;
1060                 return;
1061         }
1062
1063         /* Something failed: remote service port may have changed */
1064         rpc_force_rebind(clnt);
1065
1066         switch (status) {
1067         case -ENOTCONN:
1068         case -EAGAIN:
1069                 task->tk_action = call_bind;
1070                 if (!RPC_IS_SOFT(task))
1071                         return;
1072                 /* if soft mounted, test if we've timed out */
1073         case -ETIMEDOUT:
1074                 task->tk_action = call_timeout;
1075                 return;
1076         }
1077         rpc_exit(task, -EIO);
1078 }
1079
1080 /*
1081  * 5.   Transmit the RPC request, and wait for reply
1082  */
1083 static void
1084 call_transmit(struct rpc_task *task)
1085 {
1086         dprint_status(task);
1087
1088         task->tk_action = call_status;
1089         if (task->tk_status < 0)
1090                 return;
1091         task->tk_status = xprt_prepare_transmit(task);
1092         if (task->tk_status != 0)
1093                 return;
1094         task->tk_action = call_transmit_status;
1095         /* Encode here so that rpcsec_gss can use correct sequence number. */
1096         if (rpc_task_need_encode(task)) {
1097                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1098                 call_encode(task);
1099                 /* Did the encode result in an error condition? */
1100                 if (task->tk_status != 0)
1101                         return;
1102         }
1103         xprt_transmit(task);
1104         if (task->tk_status < 0)
1105                 return;
1106         /*
1107          * On success, ensure that we call xprt_end_transmit() before sleeping
1108          * in order to allow access to the socket to other RPC requests.
1109          */
1110         call_transmit_status(task);
1111         if (task->tk_msg.rpc_proc->p_decode != NULL)
1112                 return;
1113         task->tk_action = rpc_exit_task;
1114         rpc_wake_up_task(task);
1115 }
1116
1117 /*
1118  * 5a.  Handle cleanup after a transmission
1119  */
1120 static void
1121 call_transmit_status(struct rpc_task *task)
1122 {
1123         task->tk_action = call_status;
1124         /*
1125          * Special case: if we've been waiting on the socket's write_space()
1126          * callback, then don't call xprt_end_transmit().
1127          */
1128         if (task->tk_status == -EAGAIN)
1129                 return;
1130         xprt_end_transmit(task);
1131         rpc_task_force_reencode(task);
1132 }
1133
1134 /*
1135  * 6.   Sort out the RPC call status
1136  */
1137 static void
1138 call_status(struct rpc_task *task)
1139 {
1140         struct rpc_clnt *clnt = task->tk_client;
1141         struct rpc_rqst *req = task->tk_rqstp;
1142         int             status;
1143
1144         if (req->rq_received > 0 && !req->rq_bytes_sent)
1145                 task->tk_status = req->rq_received;
1146
1147         dprint_status(task);
1148
1149         status = task->tk_status;
1150         if (status >= 0) {
1151                 task->tk_action = call_decode;
1152                 return;
1153         }
1154
1155         task->tk_status = 0;
1156         switch(status) {
1157         case -EHOSTDOWN:
1158         case -EHOSTUNREACH:
1159         case -ENETUNREACH:
1160                 /*
1161                  * Delay any retries for 3 seconds, then handle as if it
1162                  * were a timeout.
1163                  */
1164                 rpc_delay(task, 3*HZ);
1165         case -ETIMEDOUT:
1166                 task->tk_action = call_timeout;
1167                 if (task->tk_client->cl_discrtry)
1168                         xprt_force_disconnect(task->tk_xprt);
1169                 break;
1170         case -ECONNREFUSED:
1171         case -ENOTCONN:
1172                 rpc_force_rebind(clnt);
1173                 task->tk_action = call_bind;
1174                 break;
1175         case -EAGAIN:
1176                 task->tk_action = call_transmit;
1177                 break;
1178         case -EIO:
1179                 /* shutdown or soft timeout */
1180                 rpc_exit(task, status);
1181                 break;
1182         default:
1183                 printk("%s: RPC call returned error %d\n",
1184                                clnt->cl_protname, -status);
1185                 rpc_exit(task, status);
1186         }
1187 }
1188
1189 /*
1190  * 6a.  Handle RPC timeout
1191  *      We do not release the request slot, so we keep using the
1192  *      same XID for all retransmits.
1193  */
1194 static void
1195 call_timeout(struct rpc_task *task)
1196 {
1197         struct rpc_clnt *clnt = task->tk_client;
1198
1199         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1200                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1201                 goto retry;
1202         }
1203
1204         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1205         task->tk_timeouts++;
1206
1207         if (RPC_IS_SOFT(task)) {
1208                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1209                                 clnt->cl_protname, clnt->cl_server);
1210                 rpc_exit(task, -EIO);
1211                 return;
1212         }
1213
1214         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1215                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1216                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1217                         clnt->cl_protname, clnt->cl_server);
1218         }
1219         rpc_force_rebind(clnt);
1220
1221 retry:
1222         clnt->cl_stats->rpcretrans++;
1223         task->tk_action = call_bind;
1224         task->tk_status = 0;
1225 }
1226
1227 /*
1228  * 7.   Decode the RPC reply
1229  */
1230 static void
1231 call_decode(struct rpc_task *task)
1232 {
1233         struct rpc_clnt *clnt = task->tk_client;
1234         struct rpc_rqst *req = task->tk_rqstp;
1235         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1236         __be32          *p;
1237
1238         dprintk("RPC: %5u call_decode (status %d)\n",
1239                         task->tk_pid, task->tk_status);
1240
1241         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1242                 printk(KERN_NOTICE "%s: server %s OK\n",
1243                         clnt->cl_protname, clnt->cl_server);
1244                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1245         }
1246
1247         if (task->tk_status < 12) {
1248                 if (!RPC_IS_SOFT(task)) {
1249                         task->tk_action = call_bind;
1250                         clnt->cl_stats->rpcretrans++;
1251                         goto out_retry;
1252                 }
1253                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1254                                 clnt->cl_protname, task->tk_status);
1255                 task->tk_action = call_timeout;
1256                 goto out_retry;
1257         }
1258
1259         /*
1260          * Ensure that we see all writes made by xprt_complete_rqst()
1261          * before it changed req->rq_received.
1262          */
1263         smp_rmb();
1264         req->rq_rcv_buf.len = req->rq_private_buf.len;
1265
1266         /* Check that the softirq receive buffer is valid */
1267         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1268                                 sizeof(req->rq_rcv_buf)) != 0);
1269
1270         /* Verify the RPC header */
1271         p = call_verify(task);
1272         if (IS_ERR(p)) {
1273                 if (p == ERR_PTR(-EAGAIN))
1274                         goto out_retry;
1275                 return;
1276         }
1277
1278         task->tk_action = rpc_exit_task;
1279
1280         if (decode) {
1281                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1282                                                       task->tk_msg.rpc_resp);
1283         }
1284         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1285                         task->tk_status);
1286         return;
1287 out_retry:
1288         req->rq_received = req->rq_private_buf.len = 0;
1289         task->tk_status = 0;
1290         if (task->tk_client->cl_discrtry)
1291                 xprt_force_disconnect(task->tk_xprt);
1292 }
1293
1294 /*
1295  * 8.   Refresh the credentials if rejected by the server
1296  */
1297 static void
1298 call_refresh(struct rpc_task *task)
1299 {
1300         dprint_status(task);
1301
1302         task->tk_action = call_refreshresult;
1303         task->tk_status = 0;
1304         task->tk_client->cl_stats->rpcauthrefresh++;
1305         rpcauth_refreshcred(task);
1306 }
1307
1308 /*
1309  * 8a.  Process the results of a credential refresh
1310  */
1311 static void
1312 call_refreshresult(struct rpc_task *task)
1313 {
1314         int status = task->tk_status;
1315
1316         dprint_status(task);
1317
1318         task->tk_status = 0;
1319         task->tk_action = call_reserve;
1320         if (status >= 0 && rpcauth_uptodatecred(task))
1321                 return;
1322         if (status == -EACCES) {
1323                 rpc_exit(task, -EACCES);
1324                 return;
1325         }
1326         task->tk_action = call_refresh;
1327         if (status != -ETIMEDOUT)
1328                 rpc_delay(task, 3*HZ);
1329         return;
1330 }
1331
1332 /*
1333  * Call header serialization
1334  */
1335 static __be32 *
1336 call_header(struct rpc_task *task)
1337 {
1338         struct rpc_clnt *clnt = task->tk_client;
1339         struct rpc_rqst *req = task->tk_rqstp;
1340         __be32          *p = req->rq_svec[0].iov_base;
1341
1342         /* FIXME: check buffer size? */
1343
1344         p = xprt_skip_transport_header(task->tk_xprt, p);
1345         *p++ = req->rq_xid;             /* XID */
1346         *p++ = htonl(RPC_CALL);         /* CALL */
1347         *p++ = htonl(RPC_VERSION);      /* RPC version */
1348         *p++ = htonl(clnt->cl_prog);    /* program number */
1349         *p++ = htonl(clnt->cl_vers);    /* program version */
1350         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1351         p = rpcauth_marshcred(task, p);
1352         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1353         return p;
1354 }
1355
1356 /*
1357  * Reply header verification
1358  */
1359 static __be32 *
1360 call_verify(struct rpc_task *task)
1361 {
1362         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1363         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1364         __be32  *p = iov->iov_base;
1365         u32 n;
1366         int error = -EACCES;
1367
1368         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1369                 /* RFC-1014 says that the representation of XDR data must be a
1370                  * multiple of four bytes
1371                  * - if it isn't pointer subtraction in the NFS client may give
1372                  *   undefined results
1373                  */
1374                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1375                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1376                        task->tk_rqstp->rq_rcv_buf.len);
1377                 goto out_eio;
1378         }
1379         if ((len -= 3) < 0)
1380                 goto out_overflow;
1381         p += 1; /* skip XID */
1382
1383         if ((n = ntohl(*p++)) != RPC_REPLY) {
1384                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1385                                 task->tk_pid, __FUNCTION__, n);
1386                 goto out_garbage;
1387         }
1388         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1389                 if (--len < 0)
1390                         goto out_overflow;
1391                 switch ((n = ntohl(*p++))) {
1392                         case RPC_AUTH_ERROR:
1393                                 break;
1394                         case RPC_MISMATCH:
1395                                 dprintk("RPC: %5u %s: RPC call version "
1396                                                 "mismatch!\n",
1397                                                 task->tk_pid, __FUNCTION__);
1398                                 error = -EPROTONOSUPPORT;
1399                                 goto out_err;
1400                         default:
1401                                 dprintk("RPC: %5u %s: RPC call rejected, "
1402                                                 "unknown error: %x\n",
1403                                                 task->tk_pid, __FUNCTION__, n);
1404                                 goto out_eio;
1405                 }
1406                 if (--len < 0)
1407                         goto out_overflow;
1408                 switch ((n = ntohl(*p++))) {
1409                 case RPC_AUTH_REJECTEDCRED:
1410                 case RPC_AUTH_REJECTEDVERF:
1411                 case RPCSEC_GSS_CREDPROBLEM:
1412                 case RPCSEC_GSS_CTXPROBLEM:
1413                         if (!task->tk_cred_retry)
1414                                 break;
1415                         task->tk_cred_retry--;
1416                         dprintk("RPC: %5u %s: retry stale creds\n",
1417                                         task->tk_pid, __FUNCTION__);
1418                         rpcauth_invalcred(task);
1419                         /* Ensure we obtain a new XID! */
1420                         xprt_release(task);
1421                         task->tk_action = call_refresh;
1422                         goto out_retry;
1423                 case RPC_AUTH_BADCRED:
1424                 case RPC_AUTH_BADVERF:
1425                         /* possibly garbled cred/verf? */
1426                         if (!task->tk_garb_retry)
1427                                 break;
1428                         task->tk_garb_retry--;
1429                         dprintk("RPC: %5u %s: retry garbled creds\n",
1430                                         task->tk_pid, __FUNCTION__);
1431                         task->tk_action = call_bind;
1432                         goto out_retry;
1433                 case RPC_AUTH_TOOWEAK:
1434                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1435                                "authentication.\n", task->tk_client->cl_server);
1436                         break;
1437                 default:
1438                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1439                                         task->tk_pid, __FUNCTION__, n);
1440                         error = -EIO;
1441                 }
1442                 dprintk("RPC: %5u %s: call rejected %d\n",
1443                                 task->tk_pid, __FUNCTION__, n);
1444                 goto out_err;
1445         }
1446         if (!(p = rpcauth_checkverf(task, p))) {
1447                 dprintk("RPC: %5u %s: auth check failed\n",
1448                                 task->tk_pid, __FUNCTION__);
1449                 goto out_garbage;               /* bad verifier, retry */
1450         }
1451         len = p - (__be32 *)iov->iov_base - 1;
1452         if (len < 0)
1453                 goto out_overflow;
1454         switch ((n = ntohl(*p++))) {
1455         case RPC_SUCCESS:
1456                 return p;
1457         case RPC_PROG_UNAVAIL:
1458                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1459                                 task->tk_pid, __FUNCTION__,
1460                                 (unsigned int)task->tk_client->cl_prog,
1461                                 task->tk_client->cl_server);
1462                 error = -EPFNOSUPPORT;
1463                 goto out_err;
1464         case RPC_PROG_MISMATCH:
1465                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1466                                 "server %s\n", task->tk_pid, __FUNCTION__,
1467                                 (unsigned int)task->tk_client->cl_prog,
1468                                 (unsigned int)task->tk_client->cl_vers,
1469                                 task->tk_client->cl_server);
1470                 error = -EPROTONOSUPPORT;
1471                 goto out_err;
1472         case RPC_PROC_UNAVAIL:
1473                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1474                                 "version %u on server %s\n",
1475                                 task->tk_pid, __FUNCTION__,
1476                                 task->tk_msg.rpc_proc,
1477                                 task->tk_client->cl_prog,
1478                                 task->tk_client->cl_vers,
1479                                 task->tk_client->cl_server);
1480                 error = -EOPNOTSUPP;
1481                 goto out_err;
1482         case RPC_GARBAGE_ARGS:
1483                 dprintk("RPC: %5u %s: server saw garbage\n",
1484                                 task->tk_pid, __FUNCTION__);
1485                 break;                  /* retry */
1486         default:
1487                 dprintk("RPC: %5u %s: server accept status: %x\n",
1488                                 task->tk_pid, __FUNCTION__, n);
1489                 /* Also retry */
1490         }
1491
1492 out_garbage:
1493         task->tk_client->cl_stats->rpcgarbage++;
1494         if (task->tk_garb_retry) {
1495                 task->tk_garb_retry--;
1496                 dprintk("RPC: %5u %s: retrying\n",
1497                                 task->tk_pid, __FUNCTION__);
1498                 task->tk_action = call_bind;
1499 out_retry:
1500                 return ERR_PTR(-EAGAIN);
1501         }
1502 out_eio:
1503         error = -EIO;
1504 out_err:
1505         rpc_exit(task, error);
1506         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1507                         __FUNCTION__, error);
1508         return ERR_PTR(error);
1509 out_overflow:
1510         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1511                         __FUNCTION__);
1512         goto out_garbage;
1513 }
1514
1515 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1516 {
1517         return 0;
1518 }
1519
1520 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1521 {
1522         return 0;
1523 }
1524
1525 static struct rpc_procinfo rpcproc_null = {
1526         .p_encode = rpcproc_encode_null,
1527         .p_decode = rpcproc_decode_null,
1528 };
1529
1530 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1531 {
1532         struct rpc_message msg = {
1533                 .rpc_proc = &rpcproc_null,
1534         };
1535         int err;
1536         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1537         err = rpc_call_sync(clnt, &msg, flags);
1538         put_rpccred(msg.rpc_cred);
1539         return err;
1540 }
1541
1542 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1543 {
1544         struct rpc_message msg = {
1545                 .rpc_proc = &rpcproc_null,
1546                 .rpc_cred = cred,
1547         };
1548         struct rpc_task_setup task_setup_data = {
1549                 .rpc_client = clnt,
1550                 .rpc_message = &msg,
1551                 .callback_ops = &rpc_default_ops,
1552                 .flags = flags,
1553         };
1554         return rpc_run_task(&task_setup_data);
1555 }
1556 EXPORT_SYMBOL_GPL(rpc_call_null);
1557
1558 #ifdef RPC_DEBUG
1559 void rpc_show_tasks(void)
1560 {
1561         struct rpc_clnt *clnt;
1562         struct rpc_task *t;
1563
1564         spin_lock(&rpc_client_lock);
1565         if (list_empty(&all_clients))
1566                 goto out;
1567         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1568                 "-rpcwait -action- ---ops--\n");
1569         list_for_each_entry(clnt, &all_clients, cl_clients) {
1570                 if (list_empty(&clnt->cl_tasks))
1571                         continue;
1572                 spin_lock(&clnt->cl_lock);
1573                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1574                         const char *rpc_waitq = "none";
1575                         int proc;
1576
1577                         if (t->tk_msg.rpc_proc)
1578                                 proc = t->tk_msg.rpc_proc->p_proc;
1579                         else
1580                                 proc = -1;
1581
1582                         if (RPC_IS_QUEUED(t))
1583                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1584
1585                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1586                                 t->tk_pid, proc,
1587                                 t->tk_flags, t->tk_status,
1588                                 t->tk_client,
1589                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1590                                 t->tk_rqstp, t->tk_timeout,
1591                                 rpc_waitq,
1592                                 t->tk_action, t->tk_ops);
1593                 }
1594                 spin_unlock(&clnt->cl_lock);
1595         }
1596 out:
1597         spin_unlock(&rpc_client_lock);
1598 }
1599 #endif