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