net/sunrpc/clnt.c

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