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