err.no Git - linux-2.6/blob - net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/utsname.h>
  32 #include <linux/workqueue.h>
  33
  34 #include <linux/sunrpc/clnt.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36 #include <linux/sunrpc/metrics.h>
  37
  38
  39 #ifdef RPC_DEBUG
  40 # define RPCDBG_FACILITY        RPCDBG_CALL
  41 #endif
  42
  43 #define dprint_status(t)                                        \
  44         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  45                         __FUNCTION__, t->tk_status)
  46
  47 /*
  48  * All RPC clients are linked into this list
  49  */
  50 static LIST_HEAD(all_clients);
  51 static DEFINE_SPINLOCK(rpc_client_lock);
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  54
  55
  56 static void     call_start(struct rpc_task *task);
  57 static void     call_reserve(struct rpc_task *task);
  58 static void     call_reserveresult(struct rpc_task *task);
  59 static void     call_allocate(struct rpc_task *task);
  60 static void     call_encode(struct rpc_task *task);
  61 static void     call_decode(struct rpc_task *task);
  62 static void     call_bind(struct rpc_task *task);
  63 static void     call_bind_status(struct rpc_task *task);
  64 static void     call_transmit(struct rpc_task *task);
  65 static void     call_status(struct rpc_task *task);
  66 static void     call_transmit_status(struct rpc_task *task);
  67 static void     call_refresh(struct rpc_task *task);
  68 static void     call_refreshresult(struct rpc_task *task);
  69 static void     call_timeout(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72 static __be32 * call_header(struct rpc_task *task);
  73 static __be32 * call_verify(struct rpc_task *task);
  74
  75 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  76
  77 static void rpc_register_client(struct rpc_clnt *clnt)
  78 {
  79         spin_lock(&rpc_client_lock);
  80         list_add(&clnt->cl_clients, &all_clients);
  81         spin_unlock(&rpc_client_lock);
  82 }
  83
  84 static void rpc_unregister_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_del(&clnt->cl_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static int
  92 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  93 {
  94         static uint32_t clntid;
  95         int error;
  96
  97         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  98         clnt->cl_dentry = ERR_PTR(-ENOENT);
  99         if (dir_name == NULL)
 100                 return 0;
 101
 102         clnt->cl_vfsmnt = rpc_get_mount();
 103         if (IS_ERR(clnt->cl_vfsmnt))
 104                 return PTR_ERR(clnt->cl_vfsmnt);
 105
 106         for (;;) {
 107                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 108                                 "%s/clnt%x", dir_name,
 109                                 (unsigned int)clntid++);
 110                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 111                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 112                 if (!IS_ERR(clnt->cl_dentry))
 113                         return 0;
 114                 error = PTR_ERR(clnt->cl_dentry);
 115                 if (error != -EEXIST) {
 116                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 117                                         clnt->cl_pathname, error);
 118                         rpc_put_mount();
 119                         return error;
 120                 }
 121         }
 122 }
 123
 124 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 125 {
 126         struct rpc_version      *version;
 127         struct rpc_clnt         *clnt = NULL;
 128         struct rpc_auth         *auth;
 129         int err;
 130         int len;
 131
 132         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 133                         program->name, servname, xprt);
 134
 135         err = rpciod_up();
 136         if (err)
 137                 goto out_no_rpciod;
 138         err = -EINVAL;
 139         if (!xprt)
 140                 goto out_no_xprt;
 141         if (vers >= program->nrvers || !(version = program->version[vers]))
 142                 goto out_err;
 143
 144         err = -ENOMEM;
 145         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 146         if (!clnt)
 147                 goto out_err;
 148         clnt->cl_parent = clnt;
 149
 150         clnt->cl_server = clnt->cl_inline_name;
 151         len = strlen(servname) + 1;
 152         if (len > sizeof(clnt->cl_inline_name)) {
 153                 char *buf = kmalloc(len, GFP_KERNEL);
 154                 if (buf != 0)
 155                         clnt->cl_server = buf;
 156                 else
 157                         len = sizeof(clnt->cl_inline_name);
 158         }
 159         strlcpy(clnt->cl_server, servname, len);
 160
 161         clnt->cl_xprt     = xprt;
 162         clnt->cl_procinfo = version->procs;
 163         clnt->cl_maxproc  = version->nrprocs;
 164         clnt->cl_protname = program->name;
 165         clnt->cl_prog     = program->number;
 166         clnt->cl_vers     = version->number;
 167         clnt->cl_stats    = program->stats;
 168         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 169         err = -ENOMEM;
 170         if (clnt->cl_metrics == NULL)
 171                 goto out_no_stats;
 172         clnt->cl_program  = program;
 173         INIT_LIST_HEAD(&clnt->cl_tasks);
 174         spin_lock_init(&clnt->cl_lock);
 175
 176         if (!xprt_bound(clnt->cl_xprt))
 177                 clnt->cl_autobind = 1;
 178
 179         clnt->cl_rtt = &clnt->cl_rtt_default;
 180         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 181
 182         kref_init(&clnt->cl_kref);
 183
 184         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 185         if (err < 0)
 186                 goto out_no_path;
 187
 188         auth = rpcauth_create(flavor, clnt);
 189         if (IS_ERR(auth)) {
 190                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 191                                 flavor);
 192                 err = PTR_ERR(auth);
 193                 goto out_no_auth;
 194         }
 195
 196         /* save the nodename */
 197         clnt->cl_nodelen = strlen(utsname()->nodename);
 198         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 199                 clnt->cl_nodelen = UNX_MAXNODENAME;
 200         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 201         rpc_register_client(clnt);
 202         return clnt;
 203
 204 out_no_auth:
 205         if (!IS_ERR(clnt->cl_dentry)) {
 206                 rpc_rmdir(clnt->cl_dentry);
 207                 rpc_put_mount();
 208         }
 209 out_no_path:
 210         rpc_free_iostats(clnt->cl_metrics);
 211 out_no_stats:
 212         if (clnt->cl_server != clnt->cl_inline_name)
 213                 kfree(clnt->cl_server);
 214         kfree(clnt);
 215 out_err:
 216         xprt_put(xprt);
 217 out_no_xprt:
 218         rpciod_down();
 219 out_no_rpciod:
 220         return ERR_PTR(err);
 221 }
 222
 223 /*
 224  * rpc_create - create an RPC client and transport with one call
 225  * @args: rpc_clnt create argument structure
 226  *
 227  * Creates and initializes an RPC transport and an RPC client.
 228  *
 229  * It can ping the server in order to determine if it is up, and to see if
 230  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 231  * this behavior so asynchronous tasks can also use rpc_create.
 232  */
 233 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 234 {
 235         struct rpc_xprt *xprt;
 236         struct rpc_clnt *clnt;
 237         struct rpc_xprtsock_create xprtargs = {
 238                 .proto = args->protocol,
 239                 .srcaddr = args->saddress,
 240                 .dstaddr = args->address,
 241                 .addrlen = args->addrsize,
 242                 .timeout = args->timeout
 243         };
 244         char servername[20];
 245
 246         xprt = xprt_create_transport(&xprtargs);
 247         if (IS_ERR(xprt))
 248                 return (struct rpc_clnt *)xprt;
 249
 250         /*
 251          * If the caller chooses not to specify a hostname, whip
 252          * up a string representation of the passed-in address.
 253          */
 254         if (args->servername == NULL) {
 255                 struct sockaddr_in *addr =
 256                                         (struct sockaddr_in *) &args->address;
 257                 snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 258                         NIPQUAD(addr->sin_addr.s_addr));
 259                 args->servername = servername;
 260         }
 261
 262         /*
 263          * By default, kernel RPC client connects from a reserved port.
 264          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 265          * but it is always enabled for rpciod, which handles the connect
 266          * operation.
 267          */
 268         xprt->resvport = 1;
 269         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 270                 xprt->resvport = 0;
 271
 272         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 273                         args->program->name, args->servername, xprt);
 274
 275         clnt = rpc_new_client(xprt, args->servername, args->program,
 276                                 args->version, args->authflavor);
 277         if (IS_ERR(clnt))
 278                 return clnt;
 279
 280         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 281                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 282                 if (err != 0) {
 283                         rpc_shutdown_client(clnt);
 284                         return ERR_PTR(err);
 285                 }
 286         }
 287
 288         clnt->cl_softrtry = 1;
 289         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 290                 clnt->cl_softrtry = 0;
 291
 292         if (args->flags & RPC_CLNT_CREATE_INTR)
 293                 clnt->cl_intr = 1;
 294         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 295                 clnt->cl_autobind = 1;
 296         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 297                 clnt->cl_discrtry = 1;
 298
 299         return clnt;
 300 }
 301 EXPORT_SYMBOL_GPL(rpc_create);
 302
 303 /*
 304  * This function clones the RPC client structure. It allows us to share the
 305  * same transport while varying parameters such as the authentication
 306  * flavour.
 307  */
 308 struct rpc_clnt *
 309 rpc_clone_client(struct rpc_clnt *clnt)
 310 {
 311         struct rpc_clnt *new;
 312         int err = -ENOMEM;
 313
 314         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 315         if (!new)
 316                 goto out_no_clnt;
 317         new->cl_parent = clnt;
 318         /* Turn off autobind on clones */
 319         new->cl_autobind = 0;
 320         INIT_LIST_HEAD(&new->cl_tasks);
 321         spin_lock_init(&new->cl_lock);
 322         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 323         new->cl_metrics = rpc_alloc_iostats(clnt);
 324         if (new->cl_metrics == NULL)
 325                 goto out_no_stats;
 326         kref_init(&new->cl_kref);
 327         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 328         if (err != 0)
 329                 goto out_no_path;
 330         if (new->cl_auth)
 331                 atomic_inc(&new->cl_auth->au_count);
 332         xprt_get(clnt->cl_xprt);
 333         kref_get(&clnt->cl_kref);
 334         rpc_register_client(new);
 335         rpciod_up();
 336         return new;
 337 out_no_path:
 338         rpc_free_iostats(new->cl_metrics);
 339 out_no_stats:
 340         kfree(new);
 341 out_no_clnt:
 342         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 343         return ERR_PTR(err);
 344 }
 345
 346 /*
 347  * Properly shut down an RPC client, terminating all outstanding
 348  * requests.
 349  */
 350 void rpc_shutdown_client(struct rpc_clnt *clnt)
 351 {
 352         dprintk("RPC:       shutting down %s client for %s\n",
 353                         clnt->cl_protname, clnt->cl_server);
 354
 355         while (!list_empty(&clnt->cl_tasks)) {
 356                 rpc_killall_tasks(clnt);
 357                 wait_event_timeout(destroy_wait,
 358                         list_empty(&clnt->cl_tasks), 1*HZ);
 359         }
 360
 361         rpc_release_client(clnt);
 362 }
 363
 364 /*
 365  * Free an RPC client
 366  */
 367 static void
 368 rpc_free_client(struct kref *kref)
 369 {
 370         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 371
 372         dprintk("RPC:       destroying %s client for %s\n",
 373                         clnt->cl_protname, clnt->cl_server);
 374         if (!IS_ERR(clnt->cl_dentry)) {
 375                 rpc_rmdir(clnt->cl_dentry);
 376                 rpc_put_mount();
 377         }
 378         if (clnt->cl_parent != clnt) {
 379                 rpc_release_client(clnt->cl_parent);
 380                 goto out_free;
 381         }
 382         if (clnt->cl_server != clnt->cl_inline_name)
 383                 kfree(clnt->cl_server);
 384 out_free:
 385         rpc_unregister_client(clnt);
 386         rpc_free_iostats(clnt->cl_metrics);
 387         clnt->cl_metrics = NULL;
 388         xprt_put(clnt->cl_xprt);
 389         rpciod_down();
 390         kfree(clnt);
 391 }
 392
 393 /*
 394  * Free an RPC client
 395  */
 396 static void
 397 rpc_free_auth(struct kref *kref)
 398 {
 399         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 400
 401         if (clnt->cl_auth == NULL) {
 402                 rpc_free_client(kref);
 403                 return;
 404         }
 405
 406         /*
 407          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 408          *       release remaining GSS contexts. This mechanism ensures
 409          *       that it can do so safely.
 410          */
 411         kref_init(kref);
 412         rpcauth_release(clnt->cl_auth);
 413         clnt->cl_auth = NULL;
 414         kref_put(kref, rpc_free_client);
 415 }
 416
 417 /*
 418  * Release reference to the RPC client
 419  */
 420 void
 421 rpc_release_client(struct rpc_clnt *clnt)
 422 {
 423         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 424
 425         if (list_empty(&clnt->cl_tasks))
 426                 wake_up(&destroy_wait);
 427         kref_put(&clnt->cl_kref, rpc_free_auth);
 428 }
 429
 430 /**
 431  * rpc_bind_new_program - bind a new RPC program to an existing client
 432  * @old - old rpc_client
 433  * @program - rpc program to set
 434  * @vers - rpc program version
 435  *
 436  * Clones the rpc client and sets up a new RPC program. This is mainly
 437  * of use for enabling different RPC programs to share the same transport.
 438  * The Sun NFSv2/v3 ACL protocol can do this.
 439  */
 440 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 441                                       struct rpc_program *program,
 442                                       int vers)
 443 {
 444         struct rpc_clnt *clnt;
 445         struct rpc_version *version;
 446         int err;
 447
 448         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 449         version = program->version[vers];
 450         clnt = rpc_clone_client(old);
 451         if (IS_ERR(clnt))
 452                 goto out;
 453         clnt->cl_procinfo = version->procs;
 454         clnt->cl_maxproc  = version->nrprocs;
 455         clnt->cl_protname = program->name;
 456         clnt->cl_prog     = program->number;
 457         clnt->cl_vers     = version->number;
 458         clnt->cl_stats    = program->stats;
 459         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 460         if (err != 0) {
 461                 rpc_shutdown_client(clnt);
 462                 clnt = ERR_PTR(err);
 463         }
 464 out:
 465         return clnt;
 466 }
 467
 468 /*
 469  * Default callback for async RPC calls
 470  */
 471 static void
 472 rpc_default_callback(struct rpc_task *task, void *data)
 473 {
 474 }
 475
 476 static const struct rpc_call_ops rpc_default_ops = {
 477         .rpc_call_done = rpc_default_callback,
 478 };
 479
 480 /*
 481  *      Export the signal mask handling for synchronous code that
 482  *      sleeps on RPC calls
 483  */
 484 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 485
 486 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 487 {
 488         unsigned long   sigallow = sigmask(SIGKILL);
 489         sigset_t sigmask;
 490
 491         /* Block all signals except those listed in sigallow */
 492         if (intr)
 493                 sigallow |= RPC_INTR_SIGNALS;
 494         siginitsetinv(&sigmask, sigallow);
 495         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 496 }
 497
 498 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 499 {
 500         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 501 }
 502
 503 static inline void rpc_restore_sigmask(sigset_t *oldset)
 504 {
 505         sigprocmask(SIG_SETMASK, oldset, NULL);
 506 }
 507
 508 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 509 {
 510         rpc_save_sigmask(oldset, clnt->cl_intr);
 511 }
 512
 513 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 514 {
 515         rpc_restore_sigmask(oldset);
 516 }
 517
 518 static
 519 struct rpc_task *rpc_do_run_task(struct rpc_clnt *clnt,
 520                 struct rpc_message *msg,
 521                 int flags,
 522                 const struct rpc_call_ops *ops,
 523                 void *data)
 524 {
 525         struct rpc_task *task, *ret;
 526         sigset_t oldset;
 527
 528         task = rpc_new_task(clnt, flags, ops, data);
 529         if (task == NULL) {
 530                 rpc_release_calldata(ops, data);
 531                 return ERR_PTR(-ENOMEM);
 532         }
 533
 534         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 535         rpc_task_sigmask(task, &oldset);
 536         if (msg != NULL) {
 537                 rpc_call_setup(task, msg, 0);
 538                 if (task->tk_status != 0) {
 539                         ret = ERR_PTR(task->tk_status);
 540                         rpc_put_task(task);
 541                         goto out;
 542                 }
 543         }
 544         atomic_inc(&task->tk_count);
 545         rpc_execute(task);
 546         ret = task;
 547 out:
 548         rpc_restore_sigmask(&oldset);
 549         return ret;
 550 }
 551
 552 /**
 553  * rpc_call_sync - Perform a synchronous RPC call
 554  * @clnt: pointer to RPC client
 555  * @msg: RPC call parameters
 556  * @flags: RPC call flags
 557  */
 558 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 559 {
 560         struct rpc_task *task;
 561         int status;
 562
 563         BUG_ON(flags & RPC_TASK_ASYNC);
 564
 565         task = rpc_do_run_task(clnt, msg, flags, &rpc_default_ops, NULL);
 566         if (IS_ERR(task))
 567                 return PTR_ERR(task);
 568         status = task->tk_status;
 569         rpc_put_task(task);
 570         return status;
 571 }
 572
 573 /**
 574  * rpc_call_async - Perform an asynchronous RPC call
 575  * @clnt: pointer to RPC client
 576  * @msg: RPC call parameters
 577  * @flags: RPC call flags
 578  * @ops: RPC call ops
 579  * @data: user call data
 580  */
 581 int
 582 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 583                const struct rpc_call_ops *tk_ops, void *data)
 584 {
 585         struct rpc_task *task;
 586
 587         task = rpc_do_run_task(clnt, msg, flags|RPC_TASK_ASYNC, tk_ops, data);
 588         if (IS_ERR(task))
 589                 return PTR_ERR(task);
 590         rpc_put_task(task);
 591         return 0;
 592 }
 593
 594 /**
 595  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 596  * @clnt: pointer to RPC client
 597  * @flags: RPC flags
 598  * @ops: RPC call ops
 599  * @data: user call data
 600  */
 601 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 602                                         const struct rpc_call_ops *tk_ops,
 603                                         void *data)
 604 {
 605         return rpc_do_run_task(clnt, NULL, flags, tk_ops, data);
 606 }
 607 EXPORT_SYMBOL(rpc_run_task);
 608
 609 void
 610 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 611 {
 612         task->tk_msg   = *msg;
 613         task->tk_flags |= flags;
 614         /* Bind the user cred */
 615         if (task->tk_msg.rpc_cred != NULL)
 616                 rpcauth_holdcred(task);
 617         else
 618                 rpcauth_bindcred(task);
 619
 620         if (task->tk_status == 0)
 621                 task->tk_action = call_start;
 622         else
 623                 task->tk_action = rpc_exit_task;
 624 }
 625
 626 /**
 627  * rpc_peeraddr - extract remote peer address from clnt's xprt
 628  * @clnt: RPC client structure
 629  * @buf: target buffer
 630  * @size: length of target buffer
 631  *
 632  * Returns the number of bytes that are actually in the stored address.
 633  */
 634 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 635 {
 636         size_t bytes;
 637         struct rpc_xprt *xprt = clnt->cl_xprt;
 638
 639         bytes = sizeof(xprt->addr);
 640         if (bytes > bufsize)
 641                 bytes = bufsize;
 642         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 643         return xprt->addrlen;
 644 }
 645 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 646
 647 /**
 648  * rpc_peeraddr2str - return remote peer address in printable format
 649  * @clnt: RPC client structure
 650  * @format: address format
 651  *
 652  */
 653 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 654 {
 655         struct rpc_xprt *xprt = clnt->cl_xprt;
 656
 657         if (xprt->address_strings[format] != NULL)
 658                 return xprt->address_strings[format];
 659         else
 660                 return "unprintable";
 661 }
 662 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 663
 664 void
 665 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 666 {
 667         struct rpc_xprt *xprt = clnt->cl_xprt;
 668         if (xprt->ops->set_buffer_size)
 669                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 670 }
 671
 672 /*
 673  * Return size of largest payload RPC client can support, in bytes
 674  *
 675  * For stream transports, this is one RPC record fragment (see RFC
 676  * 1831), as we don't support multi-record requests yet.  For datagram
 677  * transports, this is the size of an IP packet minus the IP, UDP, and
 678  * RPC header sizes.
 679  */
 680 size_t rpc_max_payload(struct rpc_clnt *clnt)
 681 {
 682         return clnt->cl_xprt->max_payload;
 683 }
 684 EXPORT_SYMBOL_GPL(rpc_max_payload);
 685
 686 /**
 687  * rpc_force_rebind - force transport to check that remote port is unchanged
 688  * @clnt: client to rebind
 689  *
 690  */
 691 void rpc_force_rebind(struct rpc_clnt *clnt)
 692 {
 693         if (clnt->cl_autobind)
 694                 xprt_clear_bound(clnt->cl_xprt);
 695 }
 696 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 697
 698 /*
 699  * Restart an (async) RPC call. Usually called from within the
 700  * exit handler.
 701  */
 702 void
 703 rpc_restart_call(struct rpc_task *task)
 704 {
 705         if (RPC_ASSASSINATED(task))
 706                 return;
 707
 708         task->tk_action = call_start;
 709 }
 710
 711 /*
 712  * 0.  Initial state
 713  *
 714  *     Other FSM states can be visited zero or more times, but
 715  *     this state is visited exactly once for each RPC.
 716  */
 717 static void
 718 call_start(struct rpc_task *task)
 719 {
 720         struct rpc_clnt *clnt = task->tk_client;
 721
 722         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 723                         clnt->cl_protname, clnt->cl_vers,
 724                         task->tk_msg.rpc_proc->p_proc,
 725                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 726
 727         /* Increment call count */
 728         task->tk_msg.rpc_proc->p_count++;
 729         clnt->cl_stats->rpccnt++;
 730         task->tk_action = call_reserve;
 731 }
 732
 733 /*
 734  * 1.   Reserve an RPC call slot
 735  */
 736 static void
 737 call_reserve(struct rpc_task *task)
 738 {
 739         dprint_status(task);
 740
 741         if (!rpcauth_uptodatecred(task)) {
 742                 task->tk_action = call_refresh;
 743                 return;
 744         }
 745
 746         task->tk_status  = 0;
 747         task->tk_action  = call_reserveresult;
 748         xprt_reserve(task);
 749 }
 750
 751 /*
 752  * 1b.  Grok the result of xprt_reserve()
 753  */
 754 static void
 755 call_reserveresult(struct rpc_task *task)
 756 {
 757         int status = task->tk_status;
 758
 759         dprint_status(task);
 760
 761         /*
 762          * After a call to xprt_reserve(), we must have either
 763          * a request slot or else an error status.
 764          */
 765         task->tk_status = 0;
 766         if (status >= 0) {
 767                 if (task->tk_rqstp) {
 768                         task->tk_action = call_allocate;
 769                         return;
 770                 }
 771
 772                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 773                                 __FUNCTION__, status);
 774                 rpc_exit(task, -EIO);
 775                 return;
 776         }
 777
 778         /*
 779          * Even though there was an error, we may have acquired
 780          * a request slot somehow.  Make sure not to leak it.
 781          */
 782         if (task->tk_rqstp) {
 783                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 784                                 __FUNCTION__, status);
 785                 xprt_release(task);
 786         }
 787
 788         switch (status) {
 789         case -EAGAIN:   /* woken up; retry */
 790                 task->tk_action = call_reserve;
 791                 return;
 792         case -EIO:      /* probably a shutdown */
 793                 break;
 794         default:
 795                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 796                                 __FUNCTION__, status);
 797                 break;
 798         }
 799         rpc_exit(task, status);
 800 }
 801
 802 /*
 803  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 804  *      (Note: buffer memory is freed in xprt_release).
 805  */
 806 static void
 807 call_allocate(struct rpc_task *task)
 808 {
 809         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 810         struct rpc_rqst *req = task->tk_rqstp;
 811         struct rpc_xprt *xprt = task->tk_xprt;
 812         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 813
 814         dprint_status(task);
 815
 816         task->tk_status = 0;
 817         task->tk_action = call_bind;
 818
 819         if (req->rq_buffer)
 820                 return;
 821
 822         if (proc->p_proc != 0) {
 823                 BUG_ON(proc->p_arglen == 0);
 824                 if (proc->p_decode != NULL)
 825                         BUG_ON(proc->p_replen == 0);
 826         }
 827
 828         /*
 829          * Calculate the size (in quads) of the RPC call
 830          * and reply headers, and convert both values
 831          * to byte sizes.
 832          */
 833         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 834         req->rq_callsize <<= 2;
 835         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 836         req->rq_rcvsize <<= 2;
 837
 838         req->rq_buffer = xprt->ops->buf_alloc(task,
 839                                         req->rq_callsize + req->rq_rcvsize);
 840         if (req->rq_buffer != NULL)
 841                 return;
 842
 843         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 844
 845         if (RPC_IS_ASYNC(task) || !signalled()) {
 846                 xprt_release(task);
 847                 task->tk_action = call_reserve;
 848                 rpc_delay(task, HZ>>4);
 849                 return;
 850         }
 851
 852         rpc_exit(task, -ERESTARTSYS);
 853 }
 854
 855 static inline int
 856 rpc_task_need_encode(struct rpc_task *task)
 857 {
 858         return task->tk_rqstp->rq_snd_buf.len == 0;
 859 }
 860
 861 static inline void
 862 rpc_task_force_reencode(struct rpc_task *task)
 863 {
 864         task->tk_rqstp->rq_snd_buf.len = 0;
 865 }
 866
 867 static inline void
 868 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 869 {
 870         buf->head[0].iov_base = start;
 871         buf->head[0].iov_len = len;
 872         buf->tail[0].iov_len = 0;
 873         buf->page_len = 0;
 874         buf->len = 0;
 875         buf->buflen = len;
 876 }
 877
 878 /*
 879  * 3.   Encode arguments of an RPC call
 880  */
 881 static void
 882 call_encode(struct rpc_task *task)
 883 {
 884         struct rpc_rqst *req = task->tk_rqstp;
 885         kxdrproc_t      encode;
 886         __be32          *p;
 887
 888         dprint_status(task);
 889
 890         rpc_xdr_buf_init(&req->rq_snd_buf,
 891                          req->rq_buffer,
 892                          req->rq_callsize);
 893         rpc_xdr_buf_init(&req->rq_rcv_buf,
 894                          (char *)req->rq_buffer + req->rq_callsize,
 895                          req->rq_rcvsize);
 896
 897         /* Encode header and provided arguments */
 898         encode = task->tk_msg.rpc_proc->p_encode;
 899         if (!(p = call_header(task))) {
 900                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 901                 rpc_exit(task, -EIO);
 902                 return;
 903         }
 904         if (encode == NULL)
 905                 return;
 906
 907         lock_kernel();
 908         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 909                         task->tk_msg.rpc_argp);
 910         unlock_kernel();
 911         if (task->tk_status == -ENOMEM) {
 912                 /* XXX: Is this sane? */
 913                 rpc_delay(task, 3*HZ);
 914                 task->tk_status = -EAGAIN;
 915         }
 916 }
 917
 918 /*
 919  * 4.   Get the server port number if not yet set
 920  */
 921 static void
 922 call_bind(struct rpc_task *task)
 923 {
 924         struct rpc_xprt *xprt = task->tk_xprt;
 925
 926         dprint_status(task);
 927
 928         task->tk_action = call_connect;
 929         if (!xprt_bound(xprt)) {
 930                 task->tk_action = call_bind_status;
 931                 task->tk_timeout = xprt->bind_timeout;
 932                 xprt->ops->rpcbind(task);
 933         }
 934 }
 935
 936 /*
 937  * 4a.  Sort out bind result
 938  */
 939 static void
 940 call_bind_status(struct rpc_task *task)
 941 {
 942         int status = -EACCES;
 943
 944         if (task->tk_status >= 0) {
 945                 dprint_status(task);
 946                 task->tk_status = 0;
 947                 task->tk_action = call_connect;
 948                 return;
 949         }
 950
 951         switch (task->tk_status) {
 952         case -EACCES:
 953                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 954                                 "unavailable\n", task->tk_pid);
 955                 rpc_delay(task, 3*HZ);
 956                 goto retry_timeout;
 957         case -ETIMEDOUT:
 958                 dprintk("RPC: %5u rpcbind request timed out\n",
 959                                 task->tk_pid);
 960                 goto retry_timeout;
 961         case -EPFNOSUPPORT:
 962                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 963                                 task->tk_pid);
 964                 break;
 965         case -EPROTONOSUPPORT:
 966                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 967                                 task->tk_pid);
 968                 task->tk_status = 0;
 969                 task->tk_action = call_bind;
 970                 return;
 971         default:
 972                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 973                                 task->tk_pid, -task->tk_status);
 974                 status = -EIO;
 975         }
 976
 977         rpc_exit(task, status);
 978         return;
 979
 980 retry_timeout:
 981         task->tk_action = call_timeout;
 982 }
 983
 984 /*
 985  * 4b.  Connect to the RPC server
 986  */
 987 static void
 988 call_connect(struct rpc_task *task)
 989 {
 990         struct rpc_xprt *xprt = task->tk_xprt;
 991
 992         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
 993                         task->tk_pid, xprt,
 994                         (xprt_connected(xprt) ? "is" : "is not"));
 995
 996         task->tk_action = call_transmit;
 997         if (!xprt_connected(xprt)) {
 998                 task->tk_action = call_connect_status;
 999                 if (task->tk_status < 0)
1000                         return;
1001                 xprt_connect(task);
1002         }
1003 }
1004
1005 /*
1006  * 4c.  Sort out connect result
1007  */
1008 static void
1009 call_connect_status(struct rpc_task *task)
1010 {
1011         struct rpc_clnt *clnt = task->tk_client;
1012         int status = task->tk_status;
1013
1014         dprint_status(task);
1015
1016         task->tk_status = 0;
1017         if (status >= 0) {
1018                 clnt->cl_stats->netreconn++;
1019                 task->tk_action = call_transmit;
1020                 return;
1021         }
1022
1023         /* Something failed: remote service port may have changed */
1024         rpc_force_rebind(clnt);
1025
1026         switch (status) {
1027         case -ENOTCONN:
1028         case -EAGAIN:
1029                 task->tk_action = call_bind;
1030                 if (!RPC_IS_SOFT(task))
1031                         return;
1032                 /* if soft mounted, test if we've timed out */
1033         case -ETIMEDOUT:
1034                 task->tk_action = call_timeout;
1035                 return;
1036         }
1037         rpc_exit(task, -EIO);
1038 }
1039
1040 /*
1041  * 5.   Transmit the RPC request, and wait for reply
1042  */
1043 static void
1044 call_transmit(struct rpc_task *task)
1045 {
1046         dprint_status(task);
1047
1048         task->tk_action = call_status;
1049         if (task->tk_status < 0)
1050                 return;
1051         task->tk_status = xprt_prepare_transmit(task);
1052         if (task->tk_status != 0)
1053                 return;
1054         task->tk_action = call_transmit_status;
1055         /* Encode here so that rpcsec_gss can use correct sequence number. */
1056         if (rpc_task_need_encode(task)) {
1057                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1058                 call_encode(task);
1059                 /* Did the encode result in an error condition? */
1060                 if (task->tk_status != 0)
1061                         return;
1062         }
1063         xprt_transmit(task);
1064         if (task->tk_status < 0)
1065                 return;
1066         /*
1067          * On success, ensure that we call xprt_end_transmit() before sleeping
1068          * in order to allow access to the socket to other RPC requests.
1069          */
1070         call_transmit_status(task);
1071         if (task->tk_msg.rpc_proc->p_decode != NULL)
1072                 return;
1073         task->tk_action = rpc_exit_task;
1074         rpc_wake_up_task(task);
1075 }
1076
1077 /*
1078  * 5a.  Handle cleanup after a transmission
1079  */
1080 static void
1081 call_transmit_status(struct rpc_task *task)
1082 {
1083         task->tk_action = call_status;
1084         /*
1085          * Special case: if we've been waiting on the socket's write_space()
1086          * callback, then don't call xprt_end_transmit().
1087          */
1088         if (task->tk_status == -EAGAIN)
1089                 return;
1090         xprt_end_transmit(task);
1091         rpc_task_force_reencode(task);
1092 }
1093
1094 /*
1095  * 6.   Sort out the RPC call status
1096  */
1097 static void
1098 call_status(struct rpc_task *task)
1099 {
1100         struct rpc_clnt *clnt = task->tk_client;
1101         struct rpc_rqst *req = task->tk_rqstp;
1102         int             status;
1103
1104         if (req->rq_received > 0 && !req->rq_bytes_sent)
1105                 task->tk_status = req->rq_received;
1106
1107         dprint_status(task);
1108
1109         status = task->tk_status;
1110         if (status >= 0) {
1111                 task->tk_action = call_decode;
1112                 return;
1113         }
1114
1115         task->tk_status = 0;
1116         switch(status) {
1117         case -EHOSTDOWN:
1118         case -EHOSTUNREACH:
1119         case -ENETUNREACH:
1120                 /*
1121                  * Delay any retries for 3 seconds, then handle as if it
1122                  * were a timeout.
1123                  */
1124                 rpc_delay(task, 3*HZ);
1125         case -ETIMEDOUT:
1126                 task->tk_action = call_timeout;
1127                 if (task->tk_client->cl_discrtry)
1128                         xprt_disconnect(task->tk_xprt);
1129                 break;
1130         case -ECONNREFUSED:
1131         case -ENOTCONN:
1132                 rpc_force_rebind(clnt);
1133                 task->tk_action = call_bind;
1134                 break;
1135         case -EAGAIN:
1136                 task->tk_action = call_transmit;
1137                 break;
1138         case -EIO:
1139                 /* shutdown or soft timeout */
1140                 rpc_exit(task, status);
1141                 break;
1142         default:
1143                 printk("%s: RPC call returned error %d\n",
1144                                clnt->cl_protname, -status);
1145                 rpc_exit(task, status);
1146         }
1147 }
1148
1149 /*
1150  * 6a.  Handle RPC timeout
1151  *      We do not release the request slot, so we keep using the
1152  *      same XID for all retransmits.
1153  */
1154 static void
1155 call_timeout(struct rpc_task *task)
1156 {
1157         struct rpc_clnt *clnt = task->tk_client;
1158
1159         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1160                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1161                 goto retry;
1162         }
1163
1164         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1165         task->tk_timeouts++;
1166
1167         if (RPC_IS_SOFT(task)) {
1168                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1169                                 clnt->cl_protname, clnt->cl_server);
1170                 rpc_exit(task, -EIO);
1171                 return;
1172         }
1173
1174         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1175                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1176                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1177                         clnt->cl_protname, clnt->cl_server);
1178         }
1179         rpc_force_rebind(clnt);
1180
1181 retry:
1182         clnt->cl_stats->rpcretrans++;
1183         task->tk_action = call_bind;
1184         task->tk_status = 0;
1185 }
1186
1187 /*
1188  * 7.   Decode the RPC reply
1189  */
1190 static void
1191 call_decode(struct rpc_task *task)
1192 {
1193         struct rpc_clnt *clnt = task->tk_client;
1194         struct rpc_rqst *req = task->tk_rqstp;
1195         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1196         __be32          *p;
1197
1198         dprintk("RPC: %5u call_decode (status %d)\n",
1199                         task->tk_pid, task->tk_status);
1200
1201         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1202                 printk(KERN_NOTICE "%s: server %s OK\n",
1203                         clnt->cl_protname, clnt->cl_server);
1204                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1205         }
1206
1207         if (task->tk_status < 12) {
1208                 if (!RPC_IS_SOFT(task)) {
1209                         task->tk_action = call_bind;
1210                         clnt->cl_stats->rpcretrans++;
1211                         goto out_retry;
1212                 }
1213                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1214                                 clnt->cl_protname, task->tk_status);
1215                 task->tk_action = call_timeout;
1216                 goto out_retry;
1217         }
1218
1219         /*
1220          * Ensure that we see all writes made by xprt_complete_rqst()
1221          * before it changed req->rq_received.
1222          */
1223         smp_rmb();
1224         req->rq_rcv_buf.len = req->rq_private_buf.len;
1225
1226         /* Check that the softirq receive buffer is valid */
1227         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1228                                 sizeof(req->rq_rcv_buf)) != 0);
1229
1230         /* Verify the RPC header */
1231         p = call_verify(task);
1232         if (IS_ERR(p)) {
1233                 if (p == ERR_PTR(-EAGAIN))
1234                         goto out_retry;
1235                 return;
1236         }
1237
1238         task->tk_action = rpc_exit_task;
1239
1240         if (decode) {
1241                 lock_kernel();
1242                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1243                                                       task->tk_msg.rpc_resp);
1244                 unlock_kernel();
1245         }
1246         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1247                         task->tk_status);
1248         return;
1249 out_retry:
1250         req->rq_received = req->rq_private_buf.len = 0;
1251         task->tk_status = 0;
1252         if (task->tk_client->cl_discrtry)
1253                 xprt_disconnect(task->tk_xprt);
1254 }
1255
1256 /*
1257  * 8.   Refresh the credentials if rejected by the server
1258  */
1259 static void
1260 call_refresh(struct rpc_task *task)
1261 {
1262         dprint_status(task);
1263
1264         xprt_release(task);     /* Must do to obtain new XID */
1265         task->tk_action = call_refreshresult;
1266         task->tk_status = 0;
1267         task->tk_client->cl_stats->rpcauthrefresh++;
1268         rpcauth_refreshcred(task);
1269 }
1270
1271 /*
1272  * 8a.  Process the results of a credential refresh
1273  */
1274 static void
1275 call_refreshresult(struct rpc_task *task)
1276 {
1277         int status = task->tk_status;
1278
1279         dprint_status(task);
1280
1281         task->tk_status = 0;
1282         task->tk_action = call_reserve;
1283         if (status >= 0 && rpcauth_uptodatecred(task))
1284                 return;
1285         if (status == -EACCES) {
1286                 rpc_exit(task, -EACCES);
1287                 return;
1288         }
1289         task->tk_action = call_refresh;
1290         if (status != -ETIMEDOUT)
1291                 rpc_delay(task, 3*HZ);
1292         return;
1293 }
1294
1295 /*
1296  * Call header serialization
1297  */
1298 static __be32 *
1299 call_header(struct rpc_task *task)
1300 {
1301         struct rpc_clnt *clnt = task->tk_client;
1302         struct rpc_rqst *req = task->tk_rqstp;
1303         __be32          *p = req->rq_svec[0].iov_base;
1304
1305         /* FIXME: check buffer size? */
1306
1307         p = xprt_skip_transport_header(task->tk_xprt, p);
1308         *p++ = req->rq_xid;             /* XID */
1309         *p++ = htonl(RPC_CALL);         /* CALL */
1310         *p++ = htonl(RPC_VERSION);      /* RPC version */
1311         *p++ = htonl(clnt->cl_prog);    /* program number */
1312         *p++ = htonl(clnt->cl_vers);    /* program version */
1313         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1314         p = rpcauth_marshcred(task, p);
1315         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1316         return p;
1317 }
1318
1319 /*
1320  * Reply header verification
1321  */
1322 static __be32 *
1323 call_verify(struct rpc_task *task)
1324 {
1325         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1326         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1327         __be32  *p = iov->iov_base;
1328         u32 n;
1329         int error = -EACCES;
1330
1331         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1332                 /* RFC-1014 says that the representation of XDR data must be a
1333                  * multiple of four bytes
1334                  * - if it isn't pointer subtraction in the NFS client may give
1335                  *   undefined results
1336                  */
1337                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1338                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1339                        task->tk_rqstp->rq_rcv_buf.len);
1340                 goto out_eio;
1341         }
1342         if ((len -= 3) < 0)
1343                 goto out_overflow;
1344         p += 1; /* skip XID */
1345
1346         if ((n = ntohl(*p++)) != RPC_REPLY) {
1347                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1348                                 task->tk_pid, __FUNCTION__, n);
1349                 goto out_garbage;
1350         }
1351         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1352                 if (--len < 0)
1353                         goto out_overflow;
1354                 switch ((n = ntohl(*p++))) {
1355                         case RPC_AUTH_ERROR:
1356                                 break;
1357                         case RPC_MISMATCH:
1358                                 dprintk("RPC: %5u %s: RPC call version "
1359                                                 "mismatch!\n",
1360                                                 task->tk_pid, __FUNCTION__);
1361                                 error = -EPROTONOSUPPORT;
1362                                 goto out_err;
1363                         default:
1364                                 dprintk("RPC: %5u %s: RPC call rejected, "
1365                                                 "unknown error: %x\n",
1366                                                 task->tk_pid, __FUNCTION__, n);
1367                                 goto out_eio;
1368                 }
1369                 if (--len < 0)
1370                         goto out_overflow;
1371                 switch ((n = ntohl(*p++))) {
1372                 case RPC_AUTH_REJECTEDCRED:
1373                 case RPC_AUTH_REJECTEDVERF:
1374                 case RPCSEC_GSS_CREDPROBLEM:
1375                 case RPCSEC_GSS_CTXPROBLEM:
1376                         if (!task->tk_cred_retry)
1377                                 break;
1378                         task->tk_cred_retry--;
1379                         dprintk("RPC: %5u %s: retry stale creds\n",
1380                                         task->tk_pid, __FUNCTION__);
1381                         rpcauth_invalcred(task);
1382                         task->tk_action = call_refresh;
1383                         goto out_retry;
1384                 case RPC_AUTH_BADCRED:
1385                 case RPC_AUTH_BADVERF:
1386                         /* possibly garbled cred/verf? */
1387                         if (!task->tk_garb_retry)
1388                                 break;
1389                         task->tk_garb_retry--;
1390                         dprintk("RPC: %5u %s: retry garbled creds\n",
1391                                         task->tk_pid, __FUNCTION__);
1392                         task->tk_action = call_bind;
1393                         goto out_retry;
1394                 case RPC_AUTH_TOOWEAK:
1395                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1396                                "authentication.\n", task->tk_client->cl_server);
1397                         break;
1398                 default:
1399                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1400                                         task->tk_pid, __FUNCTION__, n);
1401                         error = -EIO;
1402                 }
1403                 dprintk("RPC: %5u %s: call rejected %d\n",
1404                                 task->tk_pid, __FUNCTION__, n);
1405                 goto out_err;
1406         }
1407         if (!(p = rpcauth_checkverf(task, p))) {
1408                 dprintk("RPC: %5u %s: auth check failed\n",
1409                                 task->tk_pid, __FUNCTION__);
1410                 goto out_garbage;               /* bad verifier, retry */
1411         }
1412         len = p - (__be32 *)iov->iov_base - 1;
1413         if (len < 0)
1414                 goto out_overflow;
1415         switch ((n = ntohl(*p++))) {
1416         case RPC_SUCCESS:
1417                 return p;
1418         case RPC_PROG_UNAVAIL:
1419                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1420                                 task->tk_pid, __FUNCTION__,
1421                                 (unsigned int)task->tk_client->cl_prog,
1422                                 task->tk_client->cl_server);
1423                 error = -EPFNOSUPPORT;
1424                 goto out_err;
1425         case RPC_PROG_MISMATCH:
1426                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1427                                 "server %s\n", task->tk_pid, __FUNCTION__,
1428                                 (unsigned int)task->tk_client->cl_prog,
1429                                 (unsigned int)task->tk_client->cl_vers,
1430                                 task->tk_client->cl_server);
1431                 error = -EPROTONOSUPPORT;
1432                 goto out_err;
1433         case RPC_PROC_UNAVAIL:
1434                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1435                                 "version %u on server %s\n",
1436                                 task->tk_pid, __FUNCTION__,
1437                                 task->tk_msg.rpc_proc,
1438                                 task->tk_client->cl_prog,
1439                                 task->tk_client->cl_vers,
1440                                 task->tk_client->cl_server);
1441                 error = -EOPNOTSUPP;
1442                 goto out_err;
1443         case RPC_GARBAGE_ARGS:
1444                 dprintk("RPC: %5u %s: server saw garbage\n",
1445                                 task->tk_pid, __FUNCTION__);
1446                 break;                  /* retry */
1447         default:
1448                 dprintk("RPC: %5u %s: server accept status: %x\n",
1449                                 task->tk_pid, __FUNCTION__, n);
1450                 /* Also retry */
1451         }
1452
1453 out_garbage:
1454         task->tk_client->cl_stats->rpcgarbage++;
1455         if (task->tk_garb_retry) {
1456                 task->tk_garb_retry--;
1457                 dprintk("RPC: %5u %s: retrying\n",
1458                                 task->tk_pid, __FUNCTION__);
1459                 task->tk_action = call_bind;
1460 out_retry:
1461                 return ERR_PTR(-EAGAIN);
1462         }
1463 out_eio:
1464         error = -EIO;
1465 out_err:
1466         rpc_exit(task, error);
1467         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1468                         __FUNCTION__, error);
1469         return ERR_PTR(error);
1470 out_overflow:
1471         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1472                         __FUNCTION__);
1473         goto out_garbage;
1474 }
1475
1476 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1477 {
1478         return 0;
1479 }
1480
1481 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1482 {
1483         return 0;
1484 }
1485
1486 static struct rpc_procinfo rpcproc_null = {
1487         .p_encode = rpcproc_encode_null,
1488         .p_decode = rpcproc_decode_null,
1489 };
1490
1491 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1492 {
1493         struct rpc_message msg = {
1494                 .rpc_proc = &rpcproc_null,
1495         };
1496         int err;
1497         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1498         err = rpc_call_sync(clnt, &msg, flags);
1499         put_rpccred(msg.rpc_cred);
1500         return err;
1501 }
1502
1503 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1504 {
1505         struct rpc_message msg = {
1506                 .rpc_proc = &rpcproc_null,
1507                 .rpc_cred = cred,
1508         };
1509         return rpc_do_run_task(clnt, &msg, flags, &rpc_default_ops, NULL);
1510 }
1511 EXPORT_SYMBOL(rpc_call_null);
1512
1513 #ifdef RPC_DEBUG
1514 void rpc_show_tasks(void)
1515 {
1516         struct rpc_clnt *clnt;
1517         struct rpc_task *t;
1518
1519         spin_lock(&rpc_client_lock);
1520         if (list_empty(&all_clients))
1521                 goto out;
1522         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1523                 "-rpcwait -action- ---ops--\n");
1524         list_for_each_entry(clnt, &all_clients, cl_clients) {
1525                 if (list_empty(&clnt->cl_tasks))
1526                         continue;
1527                 spin_lock(&clnt->cl_lock);
1528                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1529                         const char *rpc_waitq = "none";
1530
1531                         if (RPC_IS_QUEUED(t))
1532                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1533
1534                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1535                                 t->tk_pid,
1536                                 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1537                                 t->tk_flags, t->tk_status,
1538                                 t->tk_client,
1539                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1540                                 t->tk_rqstp, t->tk_timeout,
1541                                 rpc_waitq,
1542                                 t->tk_action, t->tk_ops);
1543                 }
1544                 spin_unlock(&clnt->cl_lock);
1545         }
1546 out:
1547         spin_unlock(&rpc_client_lock);
1548 }
1549 #endif