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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
  34 #include <linux/sunrpc/clnt.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36 #include <linux/sunrpc/metrics.h>
  37
  38
  39 #ifdef RPC_DEBUG
  40 # define RPCDBG_FACILITY        RPCDBG_CALL
  41 #endif
  42
  43 #define dprint_status(t)                                        \
  44         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  45                         __FUNCTION__, t->tk_status)
  46
  47 /*
  48  * All RPC clients are linked into this list
  49  */
  50 static LIST_HEAD(all_clients);
  51 static DEFINE_SPINLOCK(rpc_client_lock);
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  54
  55
  56 static void     call_start(struct rpc_task *task);
  57 static void     call_reserve(struct rpc_task *task);
  58 static void     call_reserveresult(struct rpc_task *task);
  59 static void     call_allocate(struct rpc_task *task);
  60 static void     call_encode(struct rpc_task *task);
  61 static void     call_decode(struct rpc_task *task);
  62 static void     call_bind(struct rpc_task *task);
  63 static void     call_bind_status(struct rpc_task *task);
  64 static void     call_transmit(struct rpc_task *task);
  65 static void     call_status(struct rpc_task *task);
  66 static void     call_transmit_status(struct rpc_task *task);
  67 static void     call_refresh(struct rpc_task *task);
  68 static void     call_refreshresult(struct rpc_task *task);
  69 static void     call_timeout(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72 static __be32 * call_header(struct rpc_task *task);
  73 static __be32 * call_verify(struct rpc_task *task);
  74
  75 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  76
  77 static void rpc_register_client(struct rpc_clnt *clnt)
  78 {
  79         spin_lock(&rpc_client_lock);
  80         list_add(&clnt->cl_clients, &all_clients);
  81         spin_unlock(&rpc_client_lock);
  82 }
  83
  84 static void rpc_unregister_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_del(&clnt->cl_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static int
  92 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  93 {
  94         static uint32_t clntid;
  95         int error;
  96
  97         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  98         clnt->cl_dentry = ERR_PTR(-ENOENT);
  99         if (dir_name == NULL)
 100                 return 0;
 101
 102         clnt->cl_vfsmnt = rpc_get_mount();
 103         if (IS_ERR(clnt->cl_vfsmnt))
 104                 return PTR_ERR(clnt->cl_vfsmnt);
 105
 106         for (;;) {
 107                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 108                                 "%s/clnt%x", dir_name,
 109                                 (unsigned int)clntid++);
 110                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 111                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 112                 if (!IS_ERR(clnt->cl_dentry))
 113                         return 0;
 114                 error = PTR_ERR(clnt->cl_dentry);
 115                 if (error != -EEXIST) {
 116                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 117                                         clnt->cl_pathname, error);
 118                         rpc_put_mount();
 119                         return error;
 120                 }
 121         }
 122 }
 123
 124 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 125 {
 126         struct rpc_version      *version;
 127         struct rpc_clnt         *clnt = NULL;
 128         struct rpc_auth         *auth;
 129         int err;
 130         size_t len;
 131
 132         /* sanity check the name before trying to print it */
 133         err = -EINVAL;
 134         len = strlen(servname);
 135         if (len > RPC_MAXNETNAMELEN)
 136                 goto out_no_rpciod;
 137         len++;
 138
 139         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 140                         program->name, servname, xprt);
 141
 142         err = rpciod_up();
 143         if (err)
 144                 goto out_no_rpciod;
 145         err = -EINVAL;
 146         if (!xprt)
 147                 goto out_no_xprt;
 148         if (vers >= program->nrvers || !(version = program->version[vers]))
 149                 goto out_err;
 150
 151         err = -ENOMEM;
 152         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 153         if (!clnt)
 154                 goto out_err;
 155         clnt->cl_parent = clnt;
 156
 157         clnt->cl_server = clnt->cl_inline_name;
 158         if (len > sizeof(clnt->cl_inline_name)) {
 159                 char *buf = kmalloc(len, GFP_KERNEL);
 160                 if (buf != 0)
 161                         clnt->cl_server = buf;
 162                 else
 163                         len = sizeof(clnt->cl_inline_name);
 164         }
 165         strlcpy(clnt->cl_server, servname, len);
 166
 167         clnt->cl_xprt     = xprt;
 168         clnt->cl_procinfo = version->procs;
 169         clnt->cl_maxproc  = version->nrprocs;
 170         clnt->cl_protname = program->name;
 171         clnt->cl_prog     = program->number;
 172         clnt->cl_vers     = version->number;
 173         clnt->cl_stats    = program->stats;
 174         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 175         err = -ENOMEM;
 176         if (clnt->cl_metrics == NULL)
 177                 goto out_no_stats;
 178         clnt->cl_program  = program;
 179         INIT_LIST_HEAD(&clnt->cl_tasks);
 180         spin_lock_init(&clnt->cl_lock);
 181
 182         if (!xprt_bound(clnt->cl_xprt))
 183                 clnt->cl_autobind = 1;
 184
 185         clnt->cl_rtt = &clnt->cl_rtt_default;
 186         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 187
 188         kref_init(&clnt->cl_kref);
 189
 190         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 191         if (err < 0)
 192                 goto out_no_path;
 193
 194         auth = rpcauth_create(flavor, clnt);
 195         if (IS_ERR(auth)) {
 196                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 197                                 flavor);
 198                 err = PTR_ERR(auth);
 199                 goto out_no_auth;
 200         }
 201
 202         /* save the nodename */
 203         clnt->cl_nodelen = strlen(utsname()->nodename);
 204         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 205                 clnt->cl_nodelen = UNX_MAXNODENAME;
 206         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 207         rpc_register_client(clnt);
 208         return clnt;
 209
 210 out_no_auth:
 211         if (!IS_ERR(clnt->cl_dentry)) {
 212                 rpc_rmdir(clnt->cl_dentry);
 213                 rpc_put_mount();
 214         }
 215 out_no_path:
 216         rpc_free_iostats(clnt->cl_metrics);
 217 out_no_stats:
 218         if (clnt->cl_server != clnt->cl_inline_name)
 219                 kfree(clnt->cl_server);
 220         kfree(clnt);
 221 out_err:
 222         xprt_put(xprt);
 223 out_no_xprt:
 224         rpciod_down();
 225 out_no_rpciod:
 226         return ERR_PTR(err);
 227 }
 228
 229 /*
 230  * rpc_create - create an RPC client and transport with one call
 231  * @args: rpc_clnt create argument structure
 232  *
 233  * Creates and initializes an RPC transport and an RPC client.
 234  *
 235  * It can ping the server in order to determine if it is up, and to see if
 236  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 237  * this behavior so asynchronous tasks can also use rpc_create.
 238  */
 239 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 240 {
 241         struct rpc_xprt *xprt;
 242         struct rpc_clnt *clnt;
 243         struct xprt_create xprtargs = {
 244                 .ident = args->protocol,
 245                 .srcaddr = args->saddress,
 246                 .dstaddr = args->address,
 247                 .addrlen = args->addrsize,
 248                 .timeout = args->timeout
 249         };
 250         char servername[20];
 251
 252         xprt = xprt_create_transport(&xprtargs);
 253         if (IS_ERR(xprt))
 254                 return (struct rpc_clnt *)xprt;
 255
 256         /*
 257          * If the caller chooses not to specify a hostname, whip
 258          * up a string representation of the passed-in address.
 259          */
 260         if (args->servername == NULL) {
 261                 struct sockaddr_in *addr =
 262                                         (struct sockaddr_in *) args->address;
 263                 snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 264                         NIPQUAD(addr->sin_addr.s_addr));
 265                 args->servername = servername;
 266         }
 267
 268         /*
 269          * By default, kernel RPC client connects from a reserved port.
 270          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 271          * but it is always enabled for rpciod, which handles the connect
 272          * operation.
 273          */
 274         xprt->resvport = 1;
 275         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 276                 xprt->resvport = 0;
 277
 278         clnt = rpc_new_client(xprt, args->servername, args->program,
 279                                 args->version, args->authflavor);
 280         if (IS_ERR(clnt))
 281                 return clnt;
 282
 283         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 284                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 285                 if (err != 0) {
 286                         rpc_shutdown_client(clnt);
 287                         return ERR_PTR(err);
 288                 }
 289         }
 290
 291         clnt->cl_softrtry = 1;
 292         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 293                 clnt->cl_softrtry = 0;
 294
 295         if (args->flags & RPC_CLNT_CREATE_INTR)
 296                 clnt->cl_intr = 1;
 297         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 298                 clnt->cl_autobind = 1;
 299         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 300                 clnt->cl_discrtry = 1;
 301
 302         return clnt;
 303 }
 304 EXPORT_SYMBOL_GPL(rpc_create);
 305
 306 /*
 307  * This function clones the RPC client structure. It allows us to share the
 308  * same transport while varying parameters such as the authentication
 309  * flavour.
 310  */
 311 struct rpc_clnt *
 312 rpc_clone_client(struct rpc_clnt *clnt)
 313 {
 314         struct rpc_clnt *new;
 315         int err = -ENOMEM;
 316
 317         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 318         if (!new)
 319                 goto out_no_clnt;
 320         new->cl_parent = clnt;
 321         /* Turn off autobind on clones */
 322         new->cl_autobind = 0;
 323         INIT_LIST_HEAD(&new->cl_tasks);
 324         spin_lock_init(&new->cl_lock);
 325         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 326         new->cl_metrics = rpc_alloc_iostats(clnt);
 327         if (new->cl_metrics == NULL)
 328                 goto out_no_stats;
 329         kref_init(&new->cl_kref);
 330         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 331         if (err != 0)
 332                 goto out_no_path;
 333         if (new->cl_auth)
 334                 atomic_inc(&new->cl_auth->au_count);
 335         xprt_get(clnt->cl_xprt);
 336         kref_get(&clnt->cl_kref);
 337         rpc_register_client(new);
 338         rpciod_up();
 339         return new;
 340 out_no_path:
 341         rpc_free_iostats(new->cl_metrics);
 342 out_no_stats:
 343         kfree(new);
 344 out_no_clnt:
 345         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 346         return ERR_PTR(err);
 347 }
 348 EXPORT_SYMBOL_GPL(rpc_clone_client);
 349
 350 /*
 351  * Properly shut down an RPC client, terminating all outstanding
 352  * requests.
 353  */
 354 void rpc_shutdown_client(struct rpc_clnt *clnt)
 355 {
 356         dprintk("RPC:       shutting down %s client for %s\n",
 357                         clnt->cl_protname, clnt->cl_server);
 358
 359         while (!list_empty(&clnt->cl_tasks)) {
 360                 rpc_killall_tasks(clnt);
 361                 wait_event_timeout(destroy_wait,
 362                         list_empty(&clnt->cl_tasks), 1*HZ);
 363         }
 364
 365         rpc_release_client(clnt);
 366 }
 367 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 368
 369 /*
 370  * Free an RPC client
 371  */
 372 static void
 373 rpc_free_client(struct kref *kref)
 374 {
 375         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 376
 377         dprintk("RPC:       destroying %s client for %s\n",
 378                         clnt->cl_protname, clnt->cl_server);
 379         if (!IS_ERR(clnt->cl_dentry)) {
 380                 rpc_rmdir(clnt->cl_dentry);
 381                 rpc_put_mount();
 382         }
 383         if (clnt->cl_parent != clnt) {
 384                 rpc_release_client(clnt->cl_parent);
 385                 goto out_free;
 386         }
 387         if (clnt->cl_server != clnt->cl_inline_name)
 388                 kfree(clnt->cl_server);
 389 out_free:
 390         rpc_unregister_client(clnt);
 391         rpc_free_iostats(clnt->cl_metrics);
 392         clnt->cl_metrics = NULL;
 393         xprt_put(clnt->cl_xprt);
 394         rpciod_down();
 395         kfree(clnt);
 396 }
 397
 398 /*
 399  * Free an RPC client
 400  */
 401 static void
 402 rpc_free_auth(struct kref *kref)
 403 {
 404         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 405
 406         if (clnt->cl_auth == NULL) {
 407                 rpc_free_client(kref);
 408                 return;
 409         }
 410
 411         /*
 412          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 413          *       release remaining GSS contexts. This mechanism ensures
 414          *       that it can do so safely.
 415          */
 416         kref_init(kref);
 417         rpcauth_release(clnt->cl_auth);
 418         clnt->cl_auth = NULL;
 419         kref_put(kref, rpc_free_client);
 420 }
 421
 422 /*
 423  * Release reference to the RPC client
 424  */
 425 void
 426 rpc_release_client(struct rpc_clnt *clnt)
 427 {
 428         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 429
 430         if (list_empty(&clnt->cl_tasks))
 431                 wake_up(&destroy_wait);
 432         kref_put(&clnt->cl_kref, rpc_free_auth);
 433 }
 434
 435 /**
 436  * rpc_bind_new_program - bind a new RPC program to an existing client
 437  * @old - old rpc_client
 438  * @program - rpc program to set
 439  * @vers - rpc program version
 440  *
 441  * Clones the rpc client and sets up a new RPC program. This is mainly
 442  * of use for enabling different RPC programs to share the same transport.
 443  * The Sun NFSv2/v3 ACL protocol can do this.
 444  */
 445 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 446                                       struct rpc_program *program,
 447                                       u32 vers)
 448 {
 449         struct rpc_clnt *clnt;
 450         struct rpc_version *version;
 451         int err;
 452
 453         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 454         version = program->version[vers];
 455         clnt = rpc_clone_client(old);
 456         if (IS_ERR(clnt))
 457                 goto out;
 458         clnt->cl_procinfo = version->procs;
 459         clnt->cl_maxproc  = version->nrprocs;
 460         clnt->cl_protname = program->name;
 461         clnt->cl_prog     = program->number;
 462         clnt->cl_vers     = version->number;
 463         clnt->cl_stats    = program->stats;
 464         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 465         if (err != 0) {
 466                 rpc_shutdown_client(clnt);
 467                 clnt = ERR_PTR(err);
 468         }
 469 out:
 470         return clnt;
 471 }
 472 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 473
 474 /*
 475  * Default callback for async RPC calls
 476  */
 477 static void
 478 rpc_default_callback(struct rpc_task *task, void *data)
 479 {
 480 }
 481
 482 static const struct rpc_call_ops rpc_default_ops = {
 483         .rpc_call_done = rpc_default_callback,
 484 };
 485
 486 /*
 487  *      Export the signal mask handling for synchronous code that
 488  *      sleeps on RPC calls
 489  */
 490 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 491
 492 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 493 {
 494         unsigned long   sigallow = sigmask(SIGKILL);
 495         sigset_t sigmask;
 496
 497         /* Block all signals except those listed in sigallow */
 498         if (intr)
 499                 sigallow |= RPC_INTR_SIGNALS;
 500         siginitsetinv(&sigmask, sigallow);
 501         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 502 }
 503
 504 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 505 {
 506         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 507 }
 508
 509 static inline void rpc_restore_sigmask(sigset_t *oldset)
 510 {
 511         sigprocmask(SIG_SETMASK, oldset, NULL);
 512 }
 513
 514 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 515 {
 516         rpc_save_sigmask(oldset, clnt->cl_intr);
 517 }
 518 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 519
 520 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 521 {
 522         rpc_restore_sigmask(oldset);
 523 }
 524 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 525
 526 static
 527 struct rpc_task *rpc_do_run_task(const struct rpc_task_setup *task_setup_data)
 528 {
 529         struct rpc_task *task, *ret;
 530         sigset_t oldset;
 531
 532         task = rpc_new_task(task_setup_data);
 533         if (task == NULL) {
 534                 rpc_release_calldata(task_setup_data->callback_ops,
 535                                 task_setup_data->callback_data);
 536                 return ERR_PTR(-ENOMEM);
 537         }
 538
 539         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 540         rpc_task_sigmask(task, &oldset);
 541         if (task_setup_data->rpc_message != NULL) {
 542                 rpc_call_setup(task, task_setup_data->rpc_message, 0);
 543                 if (task->tk_status != 0) {
 544                         ret = ERR_PTR(task->tk_status);
 545                         rpc_put_task(task);
 546                         goto out;
 547                 }
 548         }
 549         atomic_inc(&task->tk_count);
 550         rpc_execute(task);
 551         ret = task;
 552 out:
 553         rpc_restore_sigmask(&oldset);
 554         return ret;
 555 }
 556
 557 /**
 558  * rpc_call_sync - Perform a synchronous RPC call
 559  * @clnt: pointer to RPC client
 560  * @msg: RPC call parameters
 561  * @flags: RPC call flags
 562  */
 563 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 564 {
 565         struct rpc_task *task;
 566         struct rpc_task_setup task_setup_data = {
 567                 .rpc_client = clnt,
 568                 .rpc_message = msg,
 569                 .callback_ops = &rpc_default_ops,
 570                 .flags = flags,
 571         };
 572         int status;
 573
 574         BUG_ON(flags & RPC_TASK_ASYNC);
 575
 576         task = rpc_do_run_task(&task_setup_data);
 577         if (IS_ERR(task))
 578                 return PTR_ERR(task);
 579         status = task->tk_status;
 580         rpc_put_task(task);
 581         return status;
 582 }
 583 EXPORT_SYMBOL_GPL(rpc_call_sync);
 584
 585 /**
 586  * rpc_call_async - Perform an asynchronous RPC call
 587  * @clnt: pointer to RPC client
 588  * @msg: RPC call parameters
 589  * @flags: RPC call flags
 590  * @ops: RPC call ops
 591  * @data: user call data
 592  */
 593 int
 594 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 595                const struct rpc_call_ops *tk_ops, void *data)
 596 {
 597         struct rpc_task *task;
 598         struct rpc_task_setup task_setup_data = {
 599                 .rpc_client = clnt,
 600                 .rpc_message = msg,
 601                 .callback_ops = tk_ops,
 602                 .callback_data = data,
 603                 .flags = flags|RPC_TASK_ASYNC,
 604         };
 605
 606         task = rpc_do_run_task(&task_setup_data);
 607         if (IS_ERR(task))
 608                 return PTR_ERR(task);
 609         rpc_put_task(task);
 610         return 0;
 611 }
 612 EXPORT_SYMBOL_GPL(rpc_call_async);
 613
 614 /**
 615  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 616  * @clnt: pointer to RPC client
 617  * @flags: RPC flags
 618  * @ops: RPC call ops
 619  * @data: user call data
 620  */
 621 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 622                                         const struct rpc_call_ops *tk_ops,
 623                                         void *data)
 624 {
 625         struct rpc_task_setup task_setup_data = {
 626                 .rpc_client = clnt,
 627                 .callback_ops = tk_ops,
 628                 .callback_data = data,
 629                 .flags = flags,
 630         };
 631
 632         return rpc_do_run_task(&task_setup_data);
 633 }
 634 EXPORT_SYMBOL_GPL(rpc_run_task);
 635
 636 void
 637 rpc_call_setup(struct rpc_task *task, const struct rpc_message *msg, int flags)
 638 {
 639         task->tk_msg   = *msg;
 640         task->tk_flags |= flags;
 641         /* Bind the user cred */
 642         if (task->tk_msg.rpc_cred != NULL)
 643                 rpcauth_holdcred(task);
 644         else
 645                 rpcauth_bindcred(task);
 646
 647         if (task->tk_status == 0)
 648                 task->tk_action = call_start;
 649         else
 650                 task->tk_action = rpc_exit_task;
 651 }
 652 EXPORT_SYMBOL_GPL(rpc_call_setup);
 653
 654 /**
 655  * rpc_peeraddr - extract remote peer address from clnt's xprt
 656  * @clnt: RPC client structure
 657  * @buf: target buffer
 658  * @size: length of target buffer
 659  *
 660  * Returns the number of bytes that are actually in the stored address.
 661  */
 662 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 663 {
 664         size_t bytes;
 665         struct rpc_xprt *xprt = clnt->cl_xprt;
 666
 667         bytes = sizeof(xprt->addr);
 668         if (bytes > bufsize)
 669                 bytes = bufsize;
 670         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 671         return xprt->addrlen;
 672 }
 673 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 674
 675 /**
 676  * rpc_peeraddr2str - return remote peer address in printable format
 677  * @clnt: RPC client structure
 678  * @format: address format
 679  *
 680  */
 681 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 682 {
 683         struct rpc_xprt *xprt = clnt->cl_xprt;
 684
 685         if (xprt->address_strings[format] != NULL)
 686                 return xprt->address_strings[format];
 687         else
 688                 return "unprintable";
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 691
 692 void
 693 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 694 {
 695         struct rpc_xprt *xprt = clnt->cl_xprt;
 696         if (xprt->ops->set_buffer_size)
 697                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 698 }
 699 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 700
 701 /*
 702  * Return size of largest payload RPC client can support, in bytes
 703  *
 704  * For stream transports, this is one RPC record fragment (see RFC
 705  * 1831), as we don't support multi-record requests yet.  For datagram
 706  * transports, this is the size of an IP packet minus the IP, UDP, and
 707  * RPC header sizes.
 708  */
 709 size_t rpc_max_payload(struct rpc_clnt *clnt)
 710 {
 711         return clnt->cl_xprt->max_payload;
 712 }
 713 EXPORT_SYMBOL_GPL(rpc_max_payload);
 714
 715 /**
 716  * rpc_force_rebind - force transport to check that remote port is unchanged
 717  * @clnt: client to rebind
 718  *
 719  */
 720 void rpc_force_rebind(struct rpc_clnt *clnt)
 721 {
 722         if (clnt->cl_autobind)
 723                 xprt_clear_bound(clnt->cl_xprt);
 724 }
 725 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 726
 727 /*
 728  * Restart an (async) RPC call. Usually called from within the
 729  * exit handler.
 730  */
 731 void
 732 rpc_restart_call(struct rpc_task *task)
 733 {
 734         if (RPC_ASSASSINATED(task))
 735                 return;
 736
 737         task->tk_action = call_start;
 738 }
 739 EXPORT_SYMBOL_GPL(rpc_restart_call);
 740
 741 /*
 742  * 0.  Initial state
 743  *
 744  *     Other FSM states can be visited zero or more times, but
 745  *     this state is visited exactly once for each RPC.
 746  */
 747 static void
 748 call_start(struct rpc_task *task)
 749 {
 750         struct rpc_clnt *clnt = task->tk_client;
 751
 752         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 753                         clnt->cl_protname, clnt->cl_vers,
 754                         task->tk_msg.rpc_proc->p_proc,
 755                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 756
 757         /* Increment call count */
 758         task->tk_msg.rpc_proc->p_count++;
 759         clnt->cl_stats->rpccnt++;
 760         task->tk_action = call_reserve;
 761 }
 762
 763 /*
 764  * 1.   Reserve an RPC call slot
 765  */
 766 static void
 767 call_reserve(struct rpc_task *task)
 768 {
 769         dprint_status(task);
 770
 771         if (!rpcauth_uptodatecred(task)) {
 772                 task->tk_action = call_refresh;
 773                 return;
 774         }
 775
 776         task->tk_status  = 0;
 777         task->tk_action  = call_reserveresult;
 778         xprt_reserve(task);
 779 }
 780
 781 /*
 782  * 1b.  Grok the result of xprt_reserve()
 783  */
 784 static void
 785 call_reserveresult(struct rpc_task *task)
 786 {
 787         int status = task->tk_status;
 788
 789         dprint_status(task);
 790
 791         /*
 792          * After a call to xprt_reserve(), we must have either
 793          * a request slot or else an error status.
 794          */
 795         task->tk_status = 0;
 796         if (status >= 0) {
 797                 if (task->tk_rqstp) {
 798                         task->tk_action = call_allocate;
 799                         return;
 800                 }
 801
 802                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 803                                 __FUNCTION__, status);
 804                 rpc_exit(task, -EIO);
 805                 return;
 806         }
 807
 808         /*
 809          * Even though there was an error, we may have acquired
 810          * a request slot somehow.  Make sure not to leak it.
 811          */
 812         if (task->tk_rqstp) {
 813                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 814                                 __FUNCTION__, status);
 815                 xprt_release(task);
 816         }
 817
 818         switch (status) {
 819         case -EAGAIN:   /* woken up; retry */
 820                 task->tk_action = call_reserve;
 821                 return;
 822         case -EIO:      /* probably a shutdown */
 823                 break;
 824         default:
 825                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 826                                 __FUNCTION__, status);
 827                 break;
 828         }
 829         rpc_exit(task, status);
 830 }
 831
 832 /*
 833  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 834  *      (Note: buffer memory is freed in xprt_release).
 835  */
 836 static void
 837 call_allocate(struct rpc_task *task)
 838 {
 839         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 840         struct rpc_rqst *req = task->tk_rqstp;
 841         struct rpc_xprt *xprt = task->tk_xprt;
 842         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 843
 844         dprint_status(task);
 845
 846         task->tk_status = 0;
 847         task->tk_action = call_bind;
 848
 849         if (req->rq_buffer)
 850                 return;
 851
 852         if (proc->p_proc != 0) {
 853                 BUG_ON(proc->p_arglen == 0);
 854                 if (proc->p_decode != NULL)
 855                         BUG_ON(proc->p_replen == 0);
 856         }
 857
 858         /*
 859          * Calculate the size (in quads) of the RPC call
 860          * and reply headers, and convert both values
 861          * to byte sizes.
 862          */
 863         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 864         req->rq_callsize <<= 2;
 865         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 866         req->rq_rcvsize <<= 2;
 867
 868         req->rq_buffer = xprt->ops->buf_alloc(task,
 869                                         req->rq_callsize + req->rq_rcvsize);
 870         if (req->rq_buffer != NULL)
 871                 return;
 872
 873         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 874
 875         if (RPC_IS_ASYNC(task) || !signalled()) {
 876                 task->tk_action = call_allocate;
 877                 rpc_delay(task, HZ>>4);
 878                 return;
 879         }
 880
 881         rpc_exit(task, -ERESTARTSYS);
 882 }
 883
 884 static inline int
 885 rpc_task_need_encode(struct rpc_task *task)
 886 {
 887         return task->tk_rqstp->rq_snd_buf.len == 0;
 888 }
 889
 890 static inline void
 891 rpc_task_force_reencode(struct rpc_task *task)
 892 {
 893         task->tk_rqstp->rq_snd_buf.len = 0;
 894 }
 895
 896 static inline void
 897 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 898 {
 899         buf->head[0].iov_base = start;
 900         buf->head[0].iov_len = len;
 901         buf->tail[0].iov_len = 0;
 902         buf->page_len = 0;
 903         buf->flags = 0;
 904         buf->len = 0;
 905         buf->buflen = len;
 906 }
 907
 908 /*
 909  * 3.   Encode arguments of an RPC call
 910  */
 911 static void
 912 call_encode(struct rpc_task *task)
 913 {
 914         struct rpc_rqst *req = task->tk_rqstp;
 915         kxdrproc_t      encode;
 916         __be32          *p;
 917
 918         dprint_status(task);
 919
 920         rpc_xdr_buf_init(&req->rq_snd_buf,
 921                          req->rq_buffer,
 922                          req->rq_callsize);
 923         rpc_xdr_buf_init(&req->rq_rcv_buf,
 924                          (char *)req->rq_buffer + req->rq_callsize,
 925                          req->rq_rcvsize);
 926
 927         /* Encode header and provided arguments */
 928         encode = task->tk_msg.rpc_proc->p_encode;
 929         if (!(p = call_header(task))) {
 930                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 931                 rpc_exit(task, -EIO);
 932                 return;
 933         }
 934         if (encode == NULL)
 935                 return;
 936
 937         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 938                         task->tk_msg.rpc_argp);
 939         if (task->tk_status == -ENOMEM) {
 940                 /* XXX: Is this sane? */
 941                 rpc_delay(task, 3*HZ);
 942                 task->tk_status = -EAGAIN;
 943         }
 944 }
 945
 946 /*
 947  * 4.   Get the server port number if not yet set
 948  */
 949 static void
 950 call_bind(struct rpc_task *task)
 951 {
 952         struct rpc_xprt *xprt = task->tk_xprt;
 953
 954         dprint_status(task);
 955
 956         task->tk_action = call_connect;
 957         if (!xprt_bound(xprt)) {
 958                 task->tk_action = call_bind_status;
 959                 task->tk_timeout = xprt->bind_timeout;
 960                 xprt->ops->rpcbind(task);
 961         }
 962 }
 963
 964 /*
 965  * 4a.  Sort out bind result
 966  */
 967 static void
 968 call_bind_status(struct rpc_task *task)
 969 {
 970         int status = -EIO;
 971
 972         if (task->tk_status >= 0) {
 973                 dprint_status(task);
 974                 task->tk_status = 0;
 975                 task->tk_action = call_connect;
 976                 return;
 977         }
 978
 979         switch (task->tk_status) {
 980         case -EAGAIN:
 981                 dprintk("RPC: %5u rpcbind waiting for another request "
 982                                 "to finish\n", task->tk_pid);
 983                 /* avoid busy-waiting here -- could be a network outage. */
 984                 rpc_delay(task, 5*HZ);
 985                 goto retry_timeout;
 986         case -EACCES:
 987                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 988                                 "unavailable\n", task->tk_pid);
 989                 /* fail immediately if this is an RPC ping */
 990                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 991                         status = -EOPNOTSUPP;
 992                         break;
 993                 }
 994                 rpc_delay(task, 3*HZ);
 995                 goto retry_timeout;
 996         case -ETIMEDOUT:
 997                 dprintk("RPC: %5u rpcbind request timed out\n",
 998                                 task->tk_pid);
 999                 goto retry_timeout;
1000         case -EPFNOSUPPORT:
1001                 /* server doesn't support any rpcbind version we know of */
1002                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1003                                 task->tk_pid);
1004                 break;
1005         case -EPROTONOSUPPORT:
1006                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1007                                 task->tk_pid);
1008                 task->tk_status = 0;
1009                 task->tk_action = call_bind;
1010                 return;
1011         default:
1012                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1013                                 task->tk_pid, -task->tk_status);
1014         }
1015
1016         rpc_exit(task, status);
1017         return;
1018
1019 retry_timeout:
1020         task->tk_action = call_timeout;
1021 }
1022
1023 /*
1024  * 4b.  Connect to the RPC server
1025  */
1026 static void
1027 call_connect(struct rpc_task *task)
1028 {
1029         struct rpc_xprt *xprt = task->tk_xprt;
1030
1031         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1032                         task->tk_pid, xprt,
1033                         (xprt_connected(xprt) ? "is" : "is not"));
1034
1035         task->tk_action = call_transmit;
1036         if (!xprt_connected(xprt)) {
1037                 task->tk_action = call_connect_status;
1038                 if (task->tk_status < 0)
1039                         return;
1040                 xprt_connect(task);
1041         }
1042 }
1043
1044 /*
1045  * 4c.  Sort out connect result
1046  */
1047 static void
1048 call_connect_status(struct rpc_task *task)
1049 {
1050         struct rpc_clnt *clnt = task->tk_client;
1051         int status = task->tk_status;
1052
1053         dprint_status(task);
1054
1055         task->tk_status = 0;
1056         if (status >= 0) {
1057                 clnt->cl_stats->netreconn++;
1058                 task->tk_action = call_transmit;
1059                 return;
1060         }
1061
1062         /* Something failed: remote service port may have changed */
1063         rpc_force_rebind(clnt);
1064
1065         switch (status) {
1066         case -ENOTCONN:
1067         case -EAGAIN:
1068                 task->tk_action = call_bind;
1069                 if (!RPC_IS_SOFT(task))
1070                         return;
1071                 /* if soft mounted, test if we've timed out */
1072         case -ETIMEDOUT:
1073                 task->tk_action = call_timeout;
1074                 return;
1075         }
1076         rpc_exit(task, -EIO);
1077 }
1078
1079 /*
1080  * 5.   Transmit the RPC request, and wait for reply
1081  */
1082 static void
1083 call_transmit(struct rpc_task *task)
1084 {
1085         dprint_status(task);
1086
1087         task->tk_action = call_status;
1088         if (task->tk_status < 0)
1089                 return;
1090         task->tk_status = xprt_prepare_transmit(task);
1091         if (task->tk_status != 0)
1092                 return;
1093         task->tk_action = call_transmit_status;
1094         /* Encode here so that rpcsec_gss can use correct sequence number. */
1095         if (rpc_task_need_encode(task)) {
1096                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1097                 call_encode(task);
1098                 /* Did the encode result in an error condition? */
1099                 if (task->tk_status != 0)
1100                         return;
1101         }
1102         xprt_transmit(task);
1103         if (task->tk_status < 0)
1104                 return;
1105         /*
1106          * On success, ensure that we call xprt_end_transmit() before sleeping
1107          * in order to allow access to the socket to other RPC requests.
1108          */
1109         call_transmit_status(task);
1110         if (task->tk_msg.rpc_proc->p_decode != NULL)
1111                 return;
1112         task->tk_action = rpc_exit_task;
1113         rpc_wake_up_task(task);
1114 }
1115
1116 /*
1117  * 5a.  Handle cleanup after a transmission
1118  */
1119 static void
1120 call_transmit_status(struct rpc_task *task)
1121 {
1122         task->tk_action = call_status;
1123         /*
1124          * Special case: if we've been waiting on the socket's write_space()
1125          * callback, then don't call xprt_end_transmit().
1126          */
1127         if (task->tk_status == -EAGAIN)
1128                 return;
1129         xprt_end_transmit(task);
1130         rpc_task_force_reencode(task);
1131 }
1132
1133 /*
1134  * 6.   Sort out the RPC call status
1135  */
1136 static void
1137 call_status(struct rpc_task *task)
1138 {
1139         struct rpc_clnt *clnt = task->tk_client;
1140         struct rpc_rqst *req = task->tk_rqstp;
1141         int             status;
1142
1143         if (req->rq_received > 0 && !req->rq_bytes_sent)
1144                 task->tk_status = req->rq_received;
1145
1146         dprint_status(task);
1147
1148         status = task->tk_status;
1149         if (status >= 0) {
1150                 task->tk_action = call_decode;
1151                 return;
1152         }
1153
1154         task->tk_status = 0;
1155         switch(status) {
1156         case -EHOSTDOWN:
1157         case -EHOSTUNREACH:
1158         case -ENETUNREACH:
1159                 /*
1160                  * Delay any retries for 3 seconds, then handle as if it
1161                  * were a timeout.
1162                  */
1163                 rpc_delay(task, 3*HZ);
1164         case -ETIMEDOUT:
1165                 task->tk_action = call_timeout;
1166                 if (task->tk_client->cl_discrtry)
1167                         xprt_force_disconnect(task->tk_xprt);
1168                 break;
1169         case -ECONNREFUSED:
1170         case -ENOTCONN:
1171                 rpc_force_rebind(clnt);
1172                 task->tk_action = call_bind;
1173                 break;
1174         case -EAGAIN:
1175                 task->tk_action = call_transmit;
1176                 break;
1177         case -EIO:
1178                 /* shutdown or soft timeout */
1179                 rpc_exit(task, status);
1180                 break;
1181         default:
1182                 printk("%s: RPC call returned error %d\n",
1183                                clnt->cl_protname, -status);
1184                 rpc_exit(task, status);
1185         }
1186 }
1187
1188 /*
1189  * 6a.  Handle RPC timeout
1190  *      We do not release the request slot, so we keep using the
1191  *      same XID for all retransmits.
1192  */
1193 static void
1194 call_timeout(struct rpc_task *task)
1195 {
1196         struct rpc_clnt *clnt = task->tk_client;
1197
1198         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1199                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1200                 goto retry;
1201         }
1202
1203         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1204         task->tk_timeouts++;
1205
1206         if (RPC_IS_SOFT(task)) {
1207                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1208                                 clnt->cl_protname, clnt->cl_server);
1209                 rpc_exit(task, -EIO);
1210                 return;
1211         }
1212
1213         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1214                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1215                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1216                         clnt->cl_protname, clnt->cl_server);
1217         }
1218         rpc_force_rebind(clnt);
1219
1220 retry:
1221         clnt->cl_stats->rpcretrans++;
1222         task->tk_action = call_bind;
1223         task->tk_status = 0;
1224 }
1225
1226 /*
1227  * 7.   Decode the RPC reply
1228  */
1229 static void
1230 call_decode(struct rpc_task *task)
1231 {
1232         struct rpc_clnt *clnt = task->tk_client;
1233         struct rpc_rqst *req = task->tk_rqstp;
1234         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1235         __be32          *p;
1236
1237         dprintk("RPC: %5u call_decode (status %d)\n",
1238                         task->tk_pid, task->tk_status);
1239
1240         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1241                 printk(KERN_NOTICE "%s: server %s OK\n",
1242                         clnt->cl_protname, clnt->cl_server);
1243                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1244         }
1245
1246         if (task->tk_status < 12) {
1247                 if (!RPC_IS_SOFT(task)) {
1248                         task->tk_action = call_bind;
1249                         clnt->cl_stats->rpcretrans++;
1250                         goto out_retry;
1251                 }
1252                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1253                                 clnt->cl_protname, task->tk_status);
1254                 task->tk_action = call_timeout;
1255                 goto out_retry;
1256         }
1257
1258         /*
1259          * Ensure that we see all writes made by xprt_complete_rqst()
1260          * before it changed req->rq_received.
1261          */
1262         smp_rmb();
1263         req->rq_rcv_buf.len = req->rq_private_buf.len;
1264
1265         /* Check that the softirq receive buffer is valid */
1266         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1267                                 sizeof(req->rq_rcv_buf)) != 0);
1268
1269         /* Verify the RPC header */
1270         p = call_verify(task);
1271         if (IS_ERR(p)) {
1272                 if (p == ERR_PTR(-EAGAIN))
1273                         goto out_retry;
1274                 return;
1275         }
1276
1277         task->tk_action = rpc_exit_task;
1278
1279         if (decode) {
1280                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1281                                                       task->tk_msg.rpc_resp);
1282         }
1283         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1284                         task->tk_status);
1285         return;
1286 out_retry:
1287         req->rq_received = req->rq_private_buf.len = 0;
1288         task->tk_status = 0;
1289         if (task->tk_client->cl_discrtry)
1290                 xprt_force_disconnect(task->tk_xprt);
1291 }
1292
1293 /*
1294  * 8.   Refresh the credentials if rejected by the server
1295  */
1296 static void
1297 call_refresh(struct rpc_task *task)
1298 {
1299         dprint_status(task);
1300
1301         task->tk_action = call_refreshresult;
1302         task->tk_status = 0;
1303         task->tk_client->cl_stats->rpcauthrefresh++;
1304         rpcauth_refreshcred(task);
1305 }
1306
1307 /*
1308  * 8a.  Process the results of a credential refresh
1309  */
1310 static void
1311 call_refreshresult(struct rpc_task *task)
1312 {
1313         int status = task->tk_status;
1314
1315         dprint_status(task);
1316
1317         task->tk_status = 0;
1318         task->tk_action = call_reserve;
1319         if (status >= 0 && rpcauth_uptodatecred(task))
1320                 return;
1321         if (status == -EACCES) {
1322                 rpc_exit(task, -EACCES);
1323                 return;
1324         }
1325         task->tk_action = call_refresh;
1326         if (status != -ETIMEDOUT)
1327                 rpc_delay(task, 3*HZ);
1328         return;
1329 }
1330
1331 /*
1332  * Call header serialization
1333  */
1334 static __be32 *
1335 call_header(struct rpc_task *task)
1336 {
1337         struct rpc_clnt *clnt = task->tk_client;
1338         struct rpc_rqst *req = task->tk_rqstp;
1339         __be32          *p = req->rq_svec[0].iov_base;
1340
1341         /* FIXME: check buffer size? */
1342
1343         p = xprt_skip_transport_header(task->tk_xprt, p);
1344         *p++ = req->rq_xid;             /* XID */
1345         *p++ = htonl(RPC_CALL);         /* CALL */
1346         *p++ = htonl(RPC_VERSION);      /* RPC version */
1347         *p++ = htonl(clnt->cl_prog);    /* program number */
1348         *p++ = htonl(clnt->cl_vers);    /* program version */
1349         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1350         p = rpcauth_marshcred(task, p);
1351         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1352         return p;
1353 }
1354
1355 /*
1356  * Reply header verification
1357  */
1358 static __be32 *
1359 call_verify(struct rpc_task *task)
1360 {
1361         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1362         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1363         __be32  *p = iov->iov_base;
1364         u32 n;
1365         int error = -EACCES;
1366
1367         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1368                 /* RFC-1014 says that the representation of XDR data must be a
1369                  * multiple of four bytes
1370                  * - if it isn't pointer subtraction in the NFS client may give
1371                  *   undefined results
1372                  */
1373                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1374                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1375                        task->tk_rqstp->rq_rcv_buf.len);
1376                 goto out_eio;
1377         }
1378         if ((len -= 3) < 0)
1379                 goto out_overflow;
1380         p += 1; /* skip XID */
1381
1382         if ((n = ntohl(*p++)) != RPC_REPLY) {
1383                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1384                                 task->tk_pid, __FUNCTION__, n);
1385                 goto out_garbage;
1386         }
1387         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1388                 if (--len < 0)
1389                         goto out_overflow;
1390                 switch ((n = ntohl(*p++))) {
1391                         case RPC_AUTH_ERROR:
1392                                 break;
1393                         case RPC_MISMATCH:
1394                                 dprintk("RPC: %5u %s: RPC call version "
1395                                                 "mismatch!\n",
1396                                                 task->tk_pid, __FUNCTION__);
1397                                 error = -EPROTONOSUPPORT;
1398                                 goto out_err;
1399                         default:
1400                                 dprintk("RPC: %5u %s: RPC call rejected, "
1401                                                 "unknown error: %x\n",
1402                                                 task->tk_pid, __FUNCTION__, n);
1403                                 goto out_eio;
1404                 }
1405                 if (--len < 0)
1406                         goto out_overflow;
1407                 switch ((n = ntohl(*p++))) {
1408                 case RPC_AUTH_REJECTEDCRED:
1409                 case RPC_AUTH_REJECTEDVERF:
1410                 case RPCSEC_GSS_CREDPROBLEM:
1411                 case RPCSEC_GSS_CTXPROBLEM:
1412                         if (!task->tk_cred_retry)
1413                                 break;
1414                         task->tk_cred_retry--;
1415                         dprintk("RPC: %5u %s: retry stale creds\n",
1416                                         task->tk_pid, __FUNCTION__);
1417                         rpcauth_invalcred(task);
1418                         /* Ensure we obtain a new XID! */
1419                         xprt_release(task);
1420                         task->tk_action = call_refresh;
1421                         goto out_retry;
1422                 case RPC_AUTH_BADCRED:
1423                 case RPC_AUTH_BADVERF:
1424                         /* possibly garbled cred/verf? */
1425                         if (!task->tk_garb_retry)
1426                                 break;
1427                         task->tk_garb_retry--;
1428                         dprintk("RPC: %5u %s: retry garbled creds\n",
1429                                         task->tk_pid, __FUNCTION__);
1430                         task->tk_action = call_bind;
1431                         goto out_retry;
1432                 case RPC_AUTH_TOOWEAK:
1433                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1434                                "authentication.\n", task->tk_client->cl_server);
1435                         break;
1436                 default:
1437                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1438                                         task->tk_pid, __FUNCTION__, n);
1439                         error = -EIO;
1440                 }
1441                 dprintk("RPC: %5u %s: call rejected %d\n",
1442                                 task->tk_pid, __FUNCTION__, n);
1443                 goto out_err;
1444         }
1445         if (!(p = rpcauth_checkverf(task, p))) {
1446                 dprintk("RPC: %5u %s: auth check failed\n",
1447                                 task->tk_pid, __FUNCTION__);
1448                 goto out_garbage;               /* bad verifier, retry */
1449         }
1450         len = p - (__be32 *)iov->iov_base - 1;
1451         if (len < 0)
1452                 goto out_overflow;
1453         switch ((n = ntohl(*p++))) {
1454         case RPC_SUCCESS:
1455                 return p;
1456         case RPC_PROG_UNAVAIL:
1457                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1458                                 task->tk_pid, __FUNCTION__,
1459                                 (unsigned int)task->tk_client->cl_prog,
1460                                 task->tk_client->cl_server);
1461                 error = -EPFNOSUPPORT;
1462                 goto out_err;
1463         case RPC_PROG_MISMATCH:
1464                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1465                                 "server %s\n", task->tk_pid, __FUNCTION__,
1466                                 (unsigned int)task->tk_client->cl_prog,
1467                                 (unsigned int)task->tk_client->cl_vers,
1468                                 task->tk_client->cl_server);
1469                 error = -EPROTONOSUPPORT;
1470                 goto out_err;
1471         case RPC_PROC_UNAVAIL:
1472                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1473                                 "version %u on server %s\n",
1474                                 task->tk_pid, __FUNCTION__,
1475                                 task->tk_msg.rpc_proc,
1476                                 task->tk_client->cl_prog,
1477                                 task->tk_client->cl_vers,
1478                                 task->tk_client->cl_server);
1479                 error = -EOPNOTSUPP;
1480                 goto out_err;
1481         case RPC_GARBAGE_ARGS:
1482                 dprintk("RPC: %5u %s: server saw garbage\n",
1483                                 task->tk_pid, __FUNCTION__);
1484                 break;                  /* retry */
1485         default:
1486                 dprintk("RPC: %5u %s: server accept status: %x\n",
1487                                 task->tk_pid, __FUNCTION__, n);
1488                 /* Also retry */
1489         }
1490
1491 out_garbage:
1492         task->tk_client->cl_stats->rpcgarbage++;
1493         if (task->tk_garb_retry) {
1494                 task->tk_garb_retry--;
1495                 dprintk("RPC: %5u %s: retrying\n",
1496                                 task->tk_pid, __FUNCTION__);
1497                 task->tk_action = call_bind;
1498 out_retry:
1499                 return ERR_PTR(-EAGAIN);
1500         }
1501 out_eio:
1502         error = -EIO;
1503 out_err:
1504         rpc_exit(task, error);
1505         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1506                         __FUNCTION__, error);
1507         return ERR_PTR(error);
1508 out_overflow:
1509         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1510                         __FUNCTION__);
1511         goto out_garbage;
1512 }
1513
1514 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1515 {
1516         return 0;
1517 }
1518
1519 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1520 {
1521         return 0;
1522 }
1523
1524 static struct rpc_procinfo rpcproc_null = {
1525         .p_encode = rpcproc_encode_null,
1526         .p_decode = rpcproc_decode_null,
1527 };
1528
1529 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1530 {
1531         struct rpc_message msg = {
1532                 .rpc_proc = &rpcproc_null,
1533         };
1534         int err;
1535         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1536         err = rpc_call_sync(clnt, &msg, flags);
1537         put_rpccred(msg.rpc_cred);
1538         return err;
1539 }
1540
1541 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1542 {
1543         struct rpc_message msg = {
1544                 .rpc_proc = &rpcproc_null,
1545                 .rpc_cred = cred,
1546         };
1547         struct rpc_task_setup task_setup_data = {
1548                 .rpc_client = clnt,
1549                 .rpc_message = &msg,
1550                 .callback_ops = &rpc_default_ops,
1551                 .flags = flags,
1552         };
1553         return rpc_do_run_task(&task_setup_data);
1554 }
1555 EXPORT_SYMBOL_GPL(rpc_call_null);
1556
1557 #ifdef RPC_DEBUG
1558 void rpc_show_tasks(void)
1559 {
1560         struct rpc_clnt *clnt;
1561         struct rpc_task *t;
1562
1563         spin_lock(&rpc_client_lock);
1564         if (list_empty(&all_clients))
1565                 goto out;
1566         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1567                 "-rpcwait -action- ---ops--\n");
1568         list_for_each_entry(clnt, &all_clients, cl_clients) {
1569                 if (list_empty(&clnt->cl_tasks))
1570                         continue;
1571                 spin_lock(&clnt->cl_lock);
1572                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1573                         const char *rpc_waitq = "none";
1574                         int proc;
1575
1576                         if (t->tk_msg.rpc_proc)
1577                                 proc = t->tk_msg.rpc_proc->p_proc;
1578                         else
1579                                 proc = -1;
1580
1581                         if (RPC_IS_QUEUED(t))
1582                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1583
1584                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1585                                 t->tk_pid, proc,
1586                                 t->tk_flags, t->tk_status,
1587                                 t->tk_client,
1588                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1589                                 t->tk_rqstp, t->tk_timeout,
1590                                 rpc_waitq,
1591                                 t->tk_action, t->tk_ops);
1592                 }
1593                 spin_unlock(&clnt->cl_lock);
1594         }
1595 out:
1596         spin_unlock(&rpc_client_lock);
1597 }
1598 #endif