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 #include <linux/in6.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38
  39
  40 #ifdef RPC_DEBUG
  41 # define RPCDBG_FACILITY        RPCDBG_CALL
  42 #endif
  43
  44 #define dprint_status(t)                                        \
  45         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  46                         __FUNCTION__, t->tk_status)
  47
  48 /*
  49  * All RPC clients are linked into this list
  50  */
  51 static LIST_HEAD(all_clients);
  52 static DEFINE_SPINLOCK(rpc_client_lock);
  53
  54 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  55
  56
  57 static void     call_start(struct rpc_task *task);
  58 static void     call_reserve(struct rpc_task *task);
  59 static void     call_reserveresult(struct rpc_task *task);
  60 static void     call_allocate(struct rpc_task *task);
  61 static void     call_encode(struct rpc_task *task);
  62 static void     call_decode(struct rpc_task *task);
  63 static void     call_bind(struct rpc_task *task);
  64 static void     call_bind_status(struct rpc_task *task);
  65 static void     call_transmit(struct rpc_task *task);
  66 static void     call_status(struct rpc_task *task);
  67 static void     call_transmit_status(struct rpc_task *task);
  68 static void     call_refresh(struct rpc_task *task);
  69 static void     call_refreshresult(struct rpc_task *task);
  70 static void     call_timeout(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73 static __be32 * call_header(struct rpc_task *task);
  74 static __be32 * call_verify(struct rpc_task *task);
  75
  76 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  77
  78 static void rpc_register_client(struct rpc_clnt *clnt)
  79 {
  80         spin_lock(&rpc_client_lock);
  81         list_add(&clnt->cl_clients, &all_clients);
  82         spin_unlock(&rpc_client_lock);
  83 }
  84
  85 static void rpc_unregister_client(struct rpc_clnt *clnt)
  86 {
  87         spin_lock(&rpc_client_lock);
  88         list_del(&clnt->cl_clients);
  89         spin_unlock(&rpc_client_lock);
  90 }
  91
  92 static int
  93 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  94 {
  95         static uint32_t clntid;
  96         int error;
  97
  98         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  99         clnt->cl_dentry = ERR_PTR(-ENOENT);
 100         if (dir_name == NULL)
 101                 return 0;
 102
 103         clnt->cl_vfsmnt = rpc_get_mount();
 104         if (IS_ERR(clnt->cl_vfsmnt))
 105                 return PTR_ERR(clnt->cl_vfsmnt);
 106
 107         for (;;) {
 108                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 109                                 "%s/clnt%x", dir_name,
 110                                 (unsigned int)clntid++);
 111                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 112                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 113                 if (!IS_ERR(clnt->cl_dentry))
 114                         return 0;
 115                 error = PTR_ERR(clnt->cl_dentry);
 116                 if (error != -EEXIST) {
 117                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 118                                         clnt->cl_pathname, error);
 119                         rpc_put_mount();
 120                         return error;
 121                 }
 122         }
 123 }
 124
 125 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 126 {
 127         struct rpc_program      *program = args->program;
 128         struct rpc_version      *version;
 129         struct rpc_clnt         *clnt = NULL;
 130         struct rpc_auth         *auth;
 131         int err;
 132         size_t len;
 133
 134         /* sanity check the name before trying to print it */
 135         err = -EINVAL;
 136         len = strlen(args->servername);
 137         if (len > RPC_MAXNETNAMELEN)
 138                 goto out_no_rpciod;
 139         len++;
 140
 141         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 142                         program->name, args->servername, xprt);
 143
 144         err = rpciod_up();
 145         if (err)
 146                 goto out_no_rpciod;
 147         err = -EINVAL;
 148         if (!xprt)
 149                 goto out_no_xprt;
 150
 151         if (args->version >= program->nrvers)
 152                 goto out_err;
 153         version = program->version[args->version];
 154         if (version == NULL)
 155                 goto out_err;
 156
 157         err = -ENOMEM;
 158         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 159         if (!clnt)
 160                 goto out_err;
 161         clnt->cl_parent = clnt;
 162
 163         clnt->cl_server = clnt->cl_inline_name;
 164         if (len > sizeof(clnt->cl_inline_name)) {
 165                 char *buf = kmalloc(len, GFP_KERNEL);
 166                 if (buf != NULL)
 167                         clnt->cl_server = buf;
 168                 else
 169                         len = sizeof(clnt->cl_inline_name);
 170         }
 171         strlcpy(clnt->cl_server, args->servername, len);
 172
 173         clnt->cl_xprt     = xprt;
 174         clnt->cl_procinfo = version->procs;
 175         clnt->cl_maxproc  = version->nrprocs;
 176         clnt->cl_protname = program->name;
 177         clnt->cl_prog     = program->number;
 178         clnt->cl_vers     = version->number;
 179         clnt->cl_stats    = program->stats;
 180         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 181         err = -ENOMEM;
 182         if (clnt->cl_metrics == NULL)
 183                 goto out_no_stats;
 184         clnt->cl_program  = program;
 185         INIT_LIST_HEAD(&clnt->cl_tasks);
 186         spin_lock_init(&clnt->cl_lock);
 187
 188         if (!xprt_bound(clnt->cl_xprt))
 189                 clnt->cl_autobind = 1;
 190
 191         clnt->cl_timeout = xprt->timeout;
 192         if (args->timeout != NULL) {
 193                 memcpy(&clnt->cl_timeout_default, args->timeout,
 194                                 sizeof(clnt->cl_timeout_default));
 195                 clnt->cl_timeout = &clnt->cl_timeout_default;
 196         }
 197
 198         clnt->cl_rtt = &clnt->cl_rtt_default;
 199         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 200
 201         kref_init(&clnt->cl_kref);
 202
 203         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 204         if (err < 0)
 205                 goto out_no_path;
 206
 207         auth = rpcauth_create(args->authflavor, clnt);
 208         if (IS_ERR(auth)) {
 209                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 210                                 args->authflavor);
 211                 err = PTR_ERR(auth);
 212                 goto out_no_auth;
 213         }
 214
 215         /* save the nodename */
 216         clnt->cl_nodelen = strlen(utsname()->nodename);
 217         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 218                 clnt->cl_nodelen = UNX_MAXNODENAME;
 219         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 220         rpc_register_client(clnt);
 221         return clnt;
 222
 223 out_no_auth:
 224         if (!IS_ERR(clnt->cl_dentry)) {
 225                 rpc_rmdir(clnt->cl_dentry);
 226                 rpc_put_mount();
 227         }
 228 out_no_path:
 229         rpc_free_iostats(clnt->cl_metrics);
 230 out_no_stats:
 231         if (clnt->cl_server != clnt->cl_inline_name)
 232                 kfree(clnt->cl_server);
 233         kfree(clnt);
 234 out_err:
 235         xprt_put(xprt);
 236 out_no_xprt:
 237         rpciod_down();
 238 out_no_rpciod:
 239         return ERR_PTR(err);
 240 }
 241
 242 /*
 243  * rpc_create - create an RPC client and transport with one call
 244  * @args: rpc_clnt create argument structure
 245  *
 246  * Creates and initializes an RPC transport and an RPC client.
 247  *
 248  * It can ping the server in order to determine if it is up, and to see if
 249  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 250  * this behavior so asynchronous tasks can also use rpc_create.
 251  */
 252 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 253 {
 254         struct rpc_xprt *xprt;
 255         struct rpc_clnt *clnt;
 256         struct xprt_create xprtargs = {
 257                 .ident = args->protocol,
 258                 .srcaddr = args->saddress,
 259                 .dstaddr = args->address,
 260                 .addrlen = args->addrsize,
 261         };
 262         char servername[48];
 263
 264         xprt = xprt_create_transport(&xprtargs);
 265         if (IS_ERR(xprt))
 266                 return (struct rpc_clnt *)xprt;
 267
 268         /*
 269          * If the caller chooses not to specify a hostname, whip
 270          * up a string representation of the passed-in address.
 271          */
 272         if (args->servername == NULL) {
 273                 servername[0] = '\0';
 274                 switch (args->address->sa_family) {
 275                 case AF_INET: {
 276                         struct sockaddr_in *sin =
 277                                         (struct sockaddr_in *)args->address;
 278                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 279                                  NIPQUAD(sin->sin_addr.s_addr));
 280                         break;
 281                 }
 282                 case AF_INET6: {
 283                         struct sockaddr_in6 *sin =
 284                                         (struct sockaddr_in6 *)args->address;
 285                         snprintf(servername, sizeof(servername), NIP6_FMT,
 286                                  NIP6(sin->sin6_addr));
 287                         break;
 288                 }
 289                 default:
 290                         /* caller wants default server name, but
 291                          * address family isn't recognized. */
 292                         return ERR_PTR(-EINVAL);
 293                 }
 294                 args->servername = servername;
 295         }
 296
 297         xprt = xprt_create_transport(&xprtargs);
 298         if (IS_ERR(xprt))
 299                 return (struct rpc_clnt *)xprt;
 300
 301         /*
 302          * By default, kernel RPC client connects from a reserved port.
 303          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 304          * but it is always enabled for rpciod, which handles the connect
 305          * operation.
 306          */
 307         xprt->resvport = 1;
 308         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 309                 xprt->resvport = 0;
 310
 311         clnt = rpc_new_client(args, xprt);
 312         if (IS_ERR(clnt))
 313                 return clnt;
 314
 315         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 316                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 317                 if (err != 0) {
 318                         rpc_shutdown_client(clnt);
 319                         return ERR_PTR(err);
 320                 }
 321         }
 322
 323         clnt->cl_softrtry = 1;
 324         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 325                 clnt->cl_softrtry = 0;
 326
 327         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 328                 clnt->cl_autobind = 1;
 329         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 330                 clnt->cl_discrtry = 1;
 331
 332         return clnt;
 333 }
 334 EXPORT_SYMBOL_GPL(rpc_create);
 335
 336 /*
 337  * This function clones the RPC client structure. It allows us to share the
 338  * same transport while varying parameters such as the authentication
 339  * flavour.
 340  */
 341 struct rpc_clnt *
 342 rpc_clone_client(struct rpc_clnt *clnt)
 343 {
 344         struct rpc_clnt *new;
 345         int err = -ENOMEM;
 346
 347         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 348         if (!new)
 349                 goto out_no_clnt;
 350         new->cl_parent = clnt;
 351         /* Turn off autobind on clones */
 352         new->cl_autobind = 0;
 353         INIT_LIST_HEAD(&new->cl_tasks);
 354         spin_lock_init(&new->cl_lock);
 355         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 356         new->cl_metrics = rpc_alloc_iostats(clnt);
 357         if (new->cl_metrics == NULL)
 358                 goto out_no_stats;
 359         kref_init(&new->cl_kref);
 360         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 361         if (err != 0)
 362                 goto out_no_path;
 363         if (new->cl_auth)
 364                 atomic_inc(&new->cl_auth->au_count);
 365         xprt_get(clnt->cl_xprt);
 366         kref_get(&clnt->cl_kref);
 367         rpc_register_client(new);
 368         rpciod_up();
 369         return new;
 370 out_no_path:
 371         rpc_free_iostats(new->cl_metrics);
 372 out_no_stats:
 373         kfree(new);
 374 out_no_clnt:
 375         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 376         return ERR_PTR(err);
 377 }
 378 EXPORT_SYMBOL_GPL(rpc_clone_client);
 379
 380 /*
 381  * Properly shut down an RPC client, terminating all outstanding
 382  * requests.
 383  */
 384 void rpc_shutdown_client(struct rpc_clnt *clnt)
 385 {
 386         dprintk("RPC:       shutting down %s client for %s\n",
 387                         clnt->cl_protname, clnt->cl_server);
 388
 389         while (!list_empty(&clnt->cl_tasks)) {
 390                 rpc_killall_tasks(clnt);
 391                 wait_event_timeout(destroy_wait,
 392                         list_empty(&clnt->cl_tasks), 1*HZ);
 393         }
 394
 395         rpc_release_client(clnt);
 396 }
 397 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 398
 399 /*
 400  * Free an RPC client
 401  */
 402 static void
 403 rpc_free_client(struct kref *kref)
 404 {
 405         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 406
 407         dprintk("RPC:       destroying %s client for %s\n",
 408                         clnt->cl_protname, clnt->cl_server);
 409         if (!IS_ERR(clnt->cl_dentry)) {
 410                 rpc_rmdir(clnt->cl_dentry);
 411                 rpc_put_mount();
 412         }
 413         if (clnt->cl_parent != clnt) {
 414                 rpc_release_client(clnt->cl_parent);
 415                 goto out_free;
 416         }
 417         if (clnt->cl_server != clnt->cl_inline_name)
 418                 kfree(clnt->cl_server);
 419 out_free:
 420         rpc_unregister_client(clnt);
 421         rpc_free_iostats(clnt->cl_metrics);
 422         clnt->cl_metrics = NULL;
 423         xprt_put(clnt->cl_xprt);
 424         rpciod_down();
 425         kfree(clnt);
 426 }
 427
 428 /*
 429  * Free an RPC client
 430  */
 431 static void
 432 rpc_free_auth(struct kref *kref)
 433 {
 434         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 435
 436         if (clnt->cl_auth == NULL) {
 437                 rpc_free_client(kref);
 438                 return;
 439         }
 440
 441         /*
 442          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 443          *       release remaining GSS contexts. This mechanism ensures
 444          *       that it can do so safely.
 445          */
 446         kref_init(kref);
 447         rpcauth_release(clnt->cl_auth);
 448         clnt->cl_auth = NULL;
 449         kref_put(kref, rpc_free_client);
 450 }
 451
 452 /*
 453  * Release reference to the RPC client
 454  */
 455 void
 456 rpc_release_client(struct rpc_clnt *clnt)
 457 {
 458         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 459
 460         if (list_empty(&clnt->cl_tasks))
 461                 wake_up(&destroy_wait);
 462         kref_put(&clnt->cl_kref, rpc_free_auth);
 463 }
 464
 465 /**
 466  * rpc_bind_new_program - bind a new RPC program to an existing client
 467  * @old - old rpc_client
 468  * @program - rpc program to set
 469  * @vers - rpc program version
 470  *
 471  * Clones the rpc client and sets up a new RPC program. This is mainly
 472  * of use for enabling different RPC programs to share the same transport.
 473  * The Sun NFSv2/v3 ACL protocol can do this.
 474  */
 475 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 476                                       struct rpc_program *program,
 477                                       u32 vers)
 478 {
 479         struct rpc_clnt *clnt;
 480         struct rpc_version *version;
 481         int err;
 482
 483         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 484         version = program->version[vers];
 485         clnt = rpc_clone_client(old);
 486         if (IS_ERR(clnt))
 487                 goto out;
 488         clnt->cl_procinfo = version->procs;
 489         clnt->cl_maxproc  = version->nrprocs;
 490         clnt->cl_protname = program->name;
 491         clnt->cl_prog     = program->number;
 492         clnt->cl_vers     = version->number;
 493         clnt->cl_stats    = program->stats;
 494         err = rpc_ping(clnt, RPC_TASK_SOFT);
 495         if (err != 0) {
 496                 rpc_shutdown_client(clnt);
 497                 clnt = ERR_PTR(err);
 498         }
 499 out:
 500         return clnt;
 501 }
 502 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 503
 504 /*
 505  * Default callback for async RPC calls
 506  */
 507 static void
 508 rpc_default_callback(struct rpc_task *task, void *data)
 509 {
 510 }
 511
 512 static const struct rpc_call_ops rpc_default_ops = {
 513         .rpc_call_done = rpc_default_callback,
 514 };
 515
 516 /**
 517  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 518  * @task_setup_data: pointer to task initialisation data
 519  */
 520 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 521 {
 522         struct rpc_task *task, *ret;
 523
 524         task = rpc_new_task(task_setup_data);
 525         if (task == NULL) {
 526                 rpc_release_calldata(task_setup_data->callback_ops,
 527                                 task_setup_data->callback_data);
 528                 ret = ERR_PTR(-ENOMEM);
 529                 goto out;
 530         }
 531
 532         if (task->tk_status != 0) {
 533                 ret = ERR_PTR(task->tk_status);
 534                 rpc_put_task(task);
 535                 goto out;
 536         }
 537         atomic_inc(&task->tk_count);
 538         rpc_execute(task);
 539         ret = task;
 540 out:
 541         return ret;
 542 }
 543 EXPORT_SYMBOL_GPL(rpc_run_task);
 544
 545 /**
 546  * rpc_call_sync - Perform a synchronous RPC call
 547  * @clnt: pointer to RPC client
 548  * @msg: RPC call parameters
 549  * @flags: RPC call flags
 550  */
 551 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 552 {
 553         struct rpc_task *task;
 554         struct rpc_task_setup task_setup_data = {
 555                 .rpc_client = clnt,
 556                 .rpc_message = msg,
 557                 .callback_ops = &rpc_default_ops,
 558                 .flags = flags,
 559         };
 560         int status;
 561
 562         BUG_ON(flags & RPC_TASK_ASYNC);
 563
 564         task = rpc_run_task(&task_setup_data);
 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 EXPORT_SYMBOL_GPL(rpc_call_sync);
 572
 573 /**
 574  * rpc_call_async - Perform an asynchronous RPC call
 575  * @clnt: pointer to RPC client
 576  * @msg: RPC call parameters
 577  * @flags: RPC call flags
 578  * @ops: RPC call ops
 579  * @data: user call data
 580  */
 581 int
 582 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 583                const struct rpc_call_ops *tk_ops, void *data)
 584 {
 585         struct rpc_task *task;
 586         struct rpc_task_setup task_setup_data = {
 587                 .rpc_client = clnt,
 588                 .rpc_message = msg,
 589                 .callback_ops = tk_ops,
 590                 .callback_data = data,
 591                 .flags = flags|RPC_TASK_ASYNC,
 592         };
 593
 594         task = rpc_run_task(&task_setup_data);
 595         if (IS_ERR(task))
 596                 return PTR_ERR(task);
 597         rpc_put_task(task);
 598         return 0;
 599 }
 600 EXPORT_SYMBOL_GPL(rpc_call_async);
 601
 602 void
 603 rpc_call_start(struct rpc_task *task)
 604 {
 605         task->tk_action = call_start;
 606 }
 607 EXPORT_SYMBOL_GPL(rpc_call_start);
 608
 609 /**
 610  * rpc_peeraddr - extract remote peer address from clnt's xprt
 611  * @clnt: RPC client structure
 612  * @buf: target buffer
 613  * @size: length of target buffer
 614  *
 615  * Returns the number of bytes that are actually in the stored address.
 616  */
 617 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 618 {
 619         size_t bytes;
 620         struct rpc_xprt *xprt = clnt->cl_xprt;
 621
 622         bytes = sizeof(xprt->addr);
 623         if (bytes > bufsize)
 624                 bytes = bufsize;
 625         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 626         return xprt->addrlen;
 627 }
 628 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 629
 630 /**
 631  * rpc_peeraddr2str - return remote peer address in printable format
 632  * @clnt: RPC client structure
 633  * @format: address format
 634  *
 635  */
 636 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 637                              enum rpc_display_format_t format)
 638 {
 639         struct rpc_xprt *xprt = clnt->cl_xprt;
 640
 641         if (xprt->address_strings[format] != NULL)
 642                 return xprt->address_strings[format];
 643         else
 644                 return "unprintable";
 645 }
 646 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 647
 648 void
 649 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 650 {
 651         struct rpc_xprt *xprt = clnt->cl_xprt;
 652         if (xprt->ops->set_buffer_size)
 653                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 654 }
 655 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 656
 657 /*
 658  * Return size of largest payload RPC client can support, in bytes
 659  *
 660  * For stream transports, this is one RPC record fragment (see RFC
 661  * 1831), as we don't support multi-record requests yet.  For datagram
 662  * transports, this is the size of an IP packet minus the IP, UDP, and
 663  * RPC header sizes.
 664  */
 665 size_t rpc_max_payload(struct rpc_clnt *clnt)
 666 {
 667         return clnt->cl_xprt->max_payload;
 668 }
 669 EXPORT_SYMBOL_GPL(rpc_max_payload);
 670
 671 /**
 672  * rpc_force_rebind - force transport to check that remote port is unchanged
 673  * @clnt: client to rebind
 674  *
 675  */
 676 void rpc_force_rebind(struct rpc_clnt *clnt)
 677 {
 678         if (clnt->cl_autobind)
 679                 xprt_clear_bound(clnt->cl_xprt);
 680 }
 681 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 682
 683 /*
 684  * Restart an (async) RPC call. Usually called from within the
 685  * exit handler.
 686  */
 687 void
 688 rpc_restart_call(struct rpc_task *task)
 689 {
 690         if (RPC_ASSASSINATED(task))
 691                 return;
 692
 693         task->tk_action = call_start;
 694 }
 695 EXPORT_SYMBOL_GPL(rpc_restart_call);
 696
 697 /*
 698  * 0.  Initial state
 699  *
 700  *     Other FSM states can be visited zero or more times, but
 701  *     this state is visited exactly once for each RPC.
 702  */
 703 static void
 704 call_start(struct rpc_task *task)
 705 {
 706         struct rpc_clnt *clnt = task->tk_client;
 707
 708         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 709                         clnt->cl_protname, clnt->cl_vers,
 710                         task->tk_msg.rpc_proc->p_proc,
 711                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 712
 713         /* Increment call count */
 714         task->tk_msg.rpc_proc->p_count++;
 715         clnt->cl_stats->rpccnt++;
 716         task->tk_action = call_reserve;
 717 }
 718
 719 /*
 720  * 1.   Reserve an RPC call slot
 721  */
 722 static void
 723 call_reserve(struct rpc_task *task)
 724 {
 725         dprint_status(task);
 726
 727         if (!rpcauth_uptodatecred(task)) {
 728                 task->tk_action = call_refresh;
 729                 return;
 730         }
 731
 732         task->tk_status  = 0;
 733         task->tk_action  = call_reserveresult;
 734         xprt_reserve(task);
 735 }
 736
 737 /*
 738  * 1b.  Grok the result of xprt_reserve()
 739  */
 740 static void
 741 call_reserveresult(struct rpc_task *task)
 742 {
 743         int status = task->tk_status;
 744
 745         dprint_status(task);
 746
 747         /*
 748          * After a call to xprt_reserve(), we must have either
 749          * a request slot or else an error status.
 750          */
 751         task->tk_status = 0;
 752         if (status >= 0) {
 753                 if (task->tk_rqstp) {
 754                         task->tk_action = call_allocate;
 755                         return;
 756                 }
 757
 758                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 759                                 __FUNCTION__, status);
 760                 rpc_exit(task, -EIO);
 761                 return;
 762         }
 763
 764         /*
 765          * Even though there was an error, we may have acquired
 766          * a request slot somehow.  Make sure not to leak it.
 767          */
 768         if (task->tk_rqstp) {
 769                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 770                                 __FUNCTION__, status);
 771                 xprt_release(task);
 772         }
 773
 774         switch (status) {
 775         case -EAGAIN:   /* woken up; retry */
 776                 task->tk_action = call_reserve;
 777                 return;
 778         case -EIO:      /* probably a shutdown */
 779                 break;
 780         default:
 781                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 782                                 __FUNCTION__, status);
 783                 break;
 784         }
 785         rpc_exit(task, status);
 786 }
 787
 788 /*
 789  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 790  *      (Note: buffer memory is freed in xprt_release).
 791  */
 792 static void
 793 call_allocate(struct rpc_task *task)
 794 {
 795         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 796         struct rpc_rqst *req = task->tk_rqstp;
 797         struct rpc_xprt *xprt = task->tk_xprt;
 798         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 799
 800         dprint_status(task);
 801
 802         task->tk_status = 0;
 803         task->tk_action = call_bind;
 804
 805         if (req->rq_buffer)
 806                 return;
 807
 808         if (proc->p_proc != 0) {
 809                 BUG_ON(proc->p_arglen == 0);
 810                 if (proc->p_decode != NULL)
 811                         BUG_ON(proc->p_replen == 0);
 812         }
 813
 814         /*
 815          * Calculate the size (in quads) of the RPC call
 816          * and reply headers, and convert both values
 817          * to byte sizes.
 818          */
 819         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 820         req->rq_callsize <<= 2;
 821         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 822         req->rq_rcvsize <<= 2;
 823
 824         req->rq_buffer = xprt->ops->buf_alloc(task,
 825                                         req->rq_callsize + req->rq_rcvsize);
 826         if (req->rq_buffer != NULL)
 827                 return;
 828
 829         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 830
 831         if (RPC_IS_ASYNC(task) || !signalled()) {
 832                 task->tk_action = call_allocate;
 833                 rpc_delay(task, HZ>>4);
 834                 return;
 835         }
 836
 837         rpc_exit(task, -ERESTARTSYS);
 838 }
 839
 840 static inline int
 841 rpc_task_need_encode(struct rpc_task *task)
 842 {
 843         return task->tk_rqstp->rq_snd_buf.len == 0;
 844 }
 845
 846 static inline void
 847 rpc_task_force_reencode(struct rpc_task *task)
 848 {
 849         task->tk_rqstp->rq_snd_buf.len = 0;
 850 }
 851
 852 static inline void
 853 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 854 {
 855         buf->head[0].iov_base = start;
 856         buf->head[0].iov_len = len;
 857         buf->tail[0].iov_len = 0;
 858         buf->page_len = 0;
 859         buf->flags = 0;
 860         buf->len = 0;
 861         buf->buflen = len;
 862 }
 863
 864 /*
 865  * 3.   Encode arguments of an RPC call
 866  */
 867 static void
 868 call_encode(struct rpc_task *task)
 869 {
 870         struct rpc_rqst *req = task->tk_rqstp;
 871         kxdrproc_t      encode;
 872         __be32          *p;
 873
 874         dprint_status(task);
 875
 876         rpc_xdr_buf_init(&req->rq_snd_buf,
 877                          req->rq_buffer,
 878                          req->rq_callsize);
 879         rpc_xdr_buf_init(&req->rq_rcv_buf,
 880                          (char *)req->rq_buffer + req->rq_callsize,
 881                          req->rq_rcvsize);
 882
 883         /* Encode header and provided arguments */
 884         encode = task->tk_msg.rpc_proc->p_encode;
 885         if (!(p = call_header(task))) {
 886                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 887                 rpc_exit(task, -EIO);
 888                 return;
 889         }
 890         if (encode == NULL)
 891                 return;
 892
 893         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 894                         task->tk_msg.rpc_argp);
 895         if (task->tk_status == -ENOMEM) {
 896                 /* XXX: Is this sane? */
 897                 rpc_delay(task, 3*HZ);
 898                 task->tk_status = -EAGAIN;
 899         }
 900 }
 901
 902 /*
 903  * 4.   Get the server port number if not yet set
 904  */
 905 static void
 906 call_bind(struct rpc_task *task)
 907 {
 908         struct rpc_xprt *xprt = task->tk_xprt;
 909
 910         dprint_status(task);
 911
 912         task->tk_action = call_connect;
 913         if (!xprt_bound(xprt)) {
 914                 task->tk_action = call_bind_status;
 915                 task->tk_timeout = xprt->bind_timeout;
 916                 xprt->ops->rpcbind(task);
 917         }
 918 }
 919
 920 /*
 921  * 4a.  Sort out bind result
 922  */
 923 static void
 924 call_bind_status(struct rpc_task *task)
 925 {
 926         int status = -EIO;
 927
 928         if (task->tk_status >= 0) {
 929                 dprint_status(task);
 930                 task->tk_status = 0;
 931                 task->tk_action = call_connect;
 932                 return;
 933         }
 934
 935         switch (task->tk_status) {
 936         case -EAGAIN:
 937                 dprintk("RPC: %5u rpcbind waiting for another request "
 938                                 "to finish\n", task->tk_pid);
 939                 /* avoid busy-waiting here -- could be a network outage. */
 940                 rpc_delay(task, 5*HZ);
 941                 goto retry_timeout;
 942         case -EACCES:
 943                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 944                                 "unavailable\n", task->tk_pid);
 945                 /* fail immediately if this is an RPC ping */
 946                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 947                         status = -EOPNOTSUPP;
 948                         break;
 949                 }
 950                 rpc_delay(task, 3*HZ);
 951                 goto retry_timeout;
 952         case -ETIMEDOUT:
 953                 dprintk("RPC: %5u rpcbind request timed out\n",
 954                                 task->tk_pid);
 955                 goto retry_timeout;
 956         case -EPFNOSUPPORT:
 957                 /* server doesn't support any rpcbind version we know of */
 958                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 959                                 task->tk_pid);
 960                 break;
 961         case -EPROTONOSUPPORT:
 962                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 963                                 task->tk_pid);
 964                 task->tk_status = 0;
 965                 task->tk_action = call_bind;
 966                 return;
 967         default:
 968                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 969                                 task->tk_pid, -task->tk_status);
 970         }
 971
 972         rpc_exit(task, status);
 973         return;
 974
 975 retry_timeout:
 976         task->tk_action = call_timeout;
 977 }
 978
 979 /*
 980  * 4b.  Connect to the RPC server
 981  */
 982 static void
 983 call_connect(struct rpc_task *task)
 984 {
 985         struct rpc_xprt *xprt = task->tk_xprt;
 986
 987         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
 988                         task->tk_pid, xprt,
 989                         (xprt_connected(xprt) ? "is" : "is not"));
 990
 991         task->tk_action = call_transmit;
 992         if (!xprt_connected(xprt)) {
 993                 task->tk_action = call_connect_status;
 994                 if (task->tk_status < 0)
 995                         return;
 996                 xprt_connect(task);
 997         }
 998 }
 999
1000 /*
1001  * 4c.  Sort out connect result
1002  */
1003 static void
1004 call_connect_status(struct rpc_task *task)
1005 {
1006         struct rpc_clnt *clnt = task->tk_client;
1007         int status = task->tk_status;
1008
1009         dprint_status(task);
1010
1011         task->tk_status = 0;
1012         if (status >= 0) {
1013                 clnt->cl_stats->netreconn++;
1014                 task->tk_action = call_transmit;
1015                 return;
1016         }
1017
1018         /* Something failed: remote service port may have changed */
1019         rpc_force_rebind(clnt);
1020
1021         switch (status) {
1022         case -ENOTCONN:
1023         case -EAGAIN:
1024                 task->tk_action = call_bind;
1025                 if (!RPC_IS_SOFT(task))
1026                         return;
1027                 /* if soft mounted, test if we've timed out */
1028         case -ETIMEDOUT:
1029                 task->tk_action = call_timeout;
1030                 return;
1031         }
1032         rpc_exit(task, -EIO);
1033 }
1034
1035 /*
1036  * 5.   Transmit the RPC request, and wait for reply
1037  */
1038 static void
1039 call_transmit(struct rpc_task *task)
1040 {
1041         dprint_status(task);
1042
1043         task->tk_action = call_status;
1044         if (task->tk_status < 0)
1045                 return;
1046         task->tk_status = xprt_prepare_transmit(task);
1047         if (task->tk_status != 0)
1048                 return;
1049         task->tk_action = call_transmit_status;
1050         /* Encode here so that rpcsec_gss can use correct sequence number. */
1051         if (rpc_task_need_encode(task)) {
1052                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1053                 call_encode(task);
1054                 /* Did the encode result in an error condition? */
1055                 if (task->tk_status != 0)
1056                         return;
1057         }
1058         xprt_transmit(task);
1059         if (task->tk_status < 0)
1060                 return;
1061         /*
1062          * On success, ensure that we call xprt_end_transmit() before sleeping
1063          * in order to allow access to the socket to other RPC requests.
1064          */
1065         call_transmit_status(task);
1066         if (task->tk_msg.rpc_proc->p_decode != NULL)
1067                 return;
1068         task->tk_action = rpc_exit_task;
1069         rpc_wake_up_task(task);
1070 }
1071
1072 /*
1073  * 5a.  Handle cleanup after a transmission
1074  */
1075 static void
1076 call_transmit_status(struct rpc_task *task)
1077 {
1078         task->tk_action = call_status;
1079         /*
1080          * Special case: if we've been waiting on the socket's write_space()
1081          * callback, then don't call xprt_end_transmit().
1082          */
1083         if (task->tk_status == -EAGAIN)
1084                 return;
1085         xprt_end_transmit(task);
1086         rpc_task_force_reencode(task);
1087 }
1088
1089 /*
1090  * 6.   Sort out the RPC call status
1091  */
1092 static void
1093 call_status(struct rpc_task *task)
1094 {
1095         struct rpc_clnt *clnt = task->tk_client;
1096         struct rpc_rqst *req = task->tk_rqstp;
1097         int             status;
1098
1099         if (req->rq_received > 0 && !req->rq_bytes_sent)
1100                 task->tk_status = req->rq_received;
1101
1102         dprint_status(task);
1103
1104         status = task->tk_status;
1105         if (status >= 0) {
1106                 task->tk_action = call_decode;
1107                 return;
1108         }
1109
1110         task->tk_status = 0;
1111         switch(status) {
1112         case -EHOSTDOWN:
1113         case -EHOSTUNREACH:
1114         case -ENETUNREACH:
1115                 /*
1116                  * Delay any retries for 3 seconds, then handle as if it
1117                  * were a timeout.
1118                  */
1119                 rpc_delay(task, 3*HZ);
1120         case -ETIMEDOUT:
1121                 task->tk_action = call_timeout;
1122                 if (task->tk_client->cl_discrtry)
1123                         xprt_force_disconnect(task->tk_xprt);
1124                 break;
1125         case -ECONNREFUSED:
1126         case -ENOTCONN:
1127                 rpc_force_rebind(clnt);
1128                 task->tk_action = call_bind;
1129                 break;
1130         case -EAGAIN:
1131                 task->tk_action = call_transmit;
1132                 break;
1133         case -EIO:
1134                 /* shutdown or soft timeout */
1135                 rpc_exit(task, status);
1136                 break;
1137         default:
1138                 printk("%s: RPC call returned error %d\n",
1139                                clnt->cl_protname, -status);
1140                 rpc_exit(task, status);
1141         }
1142 }
1143
1144 /*
1145  * 6a.  Handle RPC timeout
1146  *      We do not release the request slot, so we keep using the
1147  *      same XID for all retransmits.
1148  */
1149 static void
1150 call_timeout(struct rpc_task *task)
1151 {
1152         struct rpc_clnt *clnt = task->tk_client;
1153
1154         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1155                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1156                 goto retry;
1157         }
1158
1159         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1160         task->tk_timeouts++;
1161
1162         if (RPC_IS_SOFT(task)) {
1163                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1164                                 clnt->cl_protname, clnt->cl_server);
1165                 rpc_exit(task, -EIO);
1166                 return;
1167         }
1168
1169         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1170                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1171                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1172                         clnt->cl_protname, clnt->cl_server);
1173         }
1174         rpc_force_rebind(clnt);
1175
1176 retry:
1177         clnt->cl_stats->rpcretrans++;
1178         task->tk_action = call_bind;
1179         task->tk_status = 0;
1180 }
1181
1182 /*
1183  * 7.   Decode the RPC reply
1184  */
1185 static void
1186 call_decode(struct rpc_task *task)
1187 {
1188         struct rpc_clnt *clnt = task->tk_client;
1189         struct rpc_rqst *req = task->tk_rqstp;
1190         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1191         __be32          *p;
1192
1193         dprintk("RPC: %5u call_decode (status %d)\n",
1194                         task->tk_pid, task->tk_status);
1195
1196         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1197                 printk(KERN_NOTICE "%s: server %s OK\n",
1198                         clnt->cl_protname, clnt->cl_server);
1199                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1200         }
1201
1202         if (task->tk_status < 12) {
1203                 if (!RPC_IS_SOFT(task)) {
1204                         task->tk_action = call_bind;
1205                         clnt->cl_stats->rpcretrans++;
1206                         goto out_retry;
1207                 }
1208                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1209                                 clnt->cl_protname, task->tk_status);
1210                 task->tk_action = call_timeout;
1211                 goto out_retry;
1212         }
1213
1214         /*
1215          * Ensure that we see all writes made by xprt_complete_rqst()
1216          * before it changed req->rq_received.
1217          */
1218         smp_rmb();
1219         req->rq_rcv_buf.len = req->rq_private_buf.len;
1220
1221         /* Check that the softirq receive buffer is valid */
1222         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1223                                 sizeof(req->rq_rcv_buf)) != 0);
1224
1225         /* Verify the RPC header */
1226         p = call_verify(task);
1227         if (IS_ERR(p)) {
1228                 if (p == ERR_PTR(-EAGAIN))
1229                         goto out_retry;
1230                 return;
1231         }
1232
1233         task->tk_action = rpc_exit_task;
1234
1235         if (decode) {
1236                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1237                                                       task->tk_msg.rpc_resp);
1238         }
1239         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1240                         task->tk_status);
1241         return;
1242 out_retry:
1243         req->rq_received = req->rq_private_buf.len = 0;
1244         task->tk_status = 0;
1245         if (task->tk_client->cl_discrtry)
1246                 xprt_force_disconnect(task->tk_xprt);
1247 }
1248
1249 /*
1250  * 8.   Refresh the credentials if rejected by the server
1251  */
1252 static void
1253 call_refresh(struct rpc_task *task)
1254 {
1255         dprint_status(task);
1256
1257         task->tk_action = call_refreshresult;
1258         task->tk_status = 0;
1259         task->tk_client->cl_stats->rpcauthrefresh++;
1260         rpcauth_refreshcred(task);
1261 }
1262
1263 /*
1264  * 8a.  Process the results of a credential refresh
1265  */
1266 static void
1267 call_refreshresult(struct rpc_task *task)
1268 {
1269         int status = task->tk_status;
1270
1271         dprint_status(task);
1272
1273         task->tk_status = 0;
1274         task->tk_action = call_reserve;
1275         if (status >= 0 && rpcauth_uptodatecred(task))
1276                 return;
1277         if (status == -EACCES) {
1278                 rpc_exit(task, -EACCES);
1279                 return;
1280         }
1281         task->tk_action = call_refresh;
1282         if (status != -ETIMEDOUT)
1283                 rpc_delay(task, 3*HZ);
1284         return;
1285 }
1286
1287 /*
1288  * Call header serialization
1289  */
1290 static __be32 *
1291 call_header(struct rpc_task *task)
1292 {
1293         struct rpc_clnt *clnt = task->tk_client;
1294         struct rpc_rqst *req = task->tk_rqstp;
1295         __be32          *p = req->rq_svec[0].iov_base;
1296
1297         /* FIXME: check buffer size? */
1298
1299         p = xprt_skip_transport_header(task->tk_xprt, p);
1300         *p++ = req->rq_xid;             /* XID */
1301         *p++ = htonl(RPC_CALL);         /* CALL */
1302         *p++ = htonl(RPC_VERSION);      /* RPC version */
1303         *p++ = htonl(clnt->cl_prog);    /* program number */
1304         *p++ = htonl(clnt->cl_vers);    /* program version */
1305         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1306         p = rpcauth_marshcred(task, p);
1307         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1308         return p;
1309 }
1310
1311 /*
1312  * Reply header verification
1313  */
1314 static __be32 *
1315 call_verify(struct rpc_task *task)
1316 {
1317         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1318         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1319         __be32  *p = iov->iov_base;
1320         u32 n;
1321         int error = -EACCES;
1322
1323         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1324                 /* RFC-1014 says that the representation of XDR data must be a
1325                  * multiple of four bytes
1326                  * - if it isn't pointer subtraction in the NFS client may give
1327                  *   undefined results
1328                  */
1329                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1330                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1331                        task->tk_rqstp->rq_rcv_buf.len);
1332                 goto out_eio;
1333         }
1334         if ((len -= 3) < 0)
1335                 goto out_overflow;
1336         p += 1; /* skip XID */
1337
1338         if ((n = ntohl(*p++)) != RPC_REPLY) {
1339                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1340                                 task->tk_pid, __FUNCTION__, n);
1341                 goto out_garbage;
1342         }
1343         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1344                 if (--len < 0)
1345                         goto out_overflow;
1346                 switch ((n = ntohl(*p++))) {
1347                         case RPC_AUTH_ERROR:
1348                                 break;
1349                         case RPC_MISMATCH:
1350                                 dprintk("RPC: %5u %s: RPC call version "
1351                                                 "mismatch!\n",
1352                                                 task->tk_pid, __FUNCTION__);
1353                                 error = -EPROTONOSUPPORT;
1354                                 goto out_err;
1355                         default:
1356                                 dprintk("RPC: %5u %s: RPC call rejected, "
1357                                                 "unknown error: %x\n",
1358                                                 task->tk_pid, __FUNCTION__, n);
1359                                 goto out_eio;
1360                 }
1361                 if (--len < 0)
1362                         goto out_overflow;
1363                 switch ((n = ntohl(*p++))) {
1364                 case RPC_AUTH_REJECTEDCRED:
1365                 case RPC_AUTH_REJECTEDVERF:
1366                 case RPCSEC_GSS_CREDPROBLEM:
1367                 case RPCSEC_GSS_CTXPROBLEM:
1368                         if (!task->tk_cred_retry)
1369                                 break;
1370                         task->tk_cred_retry--;
1371                         dprintk("RPC: %5u %s: retry stale creds\n",
1372                                         task->tk_pid, __FUNCTION__);
1373                         rpcauth_invalcred(task);
1374                         /* Ensure we obtain a new XID! */
1375                         xprt_release(task);
1376                         task->tk_action = call_refresh;
1377                         goto out_retry;
1378                 case RPC_AUTH_BADCRED:
1379                 case RPC_AUTH_BADVERF:
1380                         /* possibly garbled cred/verf? */
1381                         if (!task->tk_garb_retry)
1382                                 break;
1383                         task->tk_garb_retry--;
1384                         dprintk("RPC: %5u %s: retry garbled creds\n",
1385                                         task->tk_pid, __FUNCTION__);
1386                         task->tk_action = call_bind;
1387                         goto out_retry;
1388                 case RPC_AUTH_TOOWEAK:
1389                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1390                                "authentication.\n", task->tk_client->cl_server);
1391                         break;
1392                 default:
1393                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1394                                         task->tk_pid, __FUNCTION__, n);
1395                         error = -EIO;
1396                 }
1397                 dprintk("RPC: %5u %s: call rejected %d\n",
1398                                 task->tk_pid, __FUNCTION__, n);
1399                 goto out_err;
1400         }
1401         if (!(p = rpcauth_checkverf(task, p))) {
1402                 dprintk("RPC: %5u %s: auth check failed\n",
1403                                 task->tk_pid, __FUNCTION__);
1404                 goto out_garbage;               /* bad verifier, retry */
1405         }
1406         len = p - (__be32 *)iov->iov_base - 1;
1407         if (len < 0)
1408                 goto out_overflow;
1409         switch ((n = ntohl(*p++))) {
1410         case RPC_SUCCESS:
1411                 return p;
1412         case RPC_PROG_UNAVAIL:
1413                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1414                                 task->tk_pid, __FUNCTION__,
1415                                 (unsigned int)task->tk_client->cl_prog,
1416                                 task->tk_client->cl_server);
1417                 error = -EPFNOSUPPORT;
1418                 goto out_err;
1419         case RPC_PROG_MISMATCH:
1420                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1421                                 "server %s\n", task->tk_pid, __FUNCTION__,
1422                                 (unsigned int)task->tk_client->cl_prog,
1423                                 (unsigned int)task->tk_client->cl_vers,
1424                                 task->tk_client->cl_server);
1425                 error = -EPROTONOSUPPORT;
1426                 goto out_err;
1427         case RPC_PROC_UNAVAIL:
1428                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1429                                 "version %u on server %s\n",
1430                                 task->tk_pid, __FUNCTION__,
1431                                 task->tk_msg.rpc_proc,
1432                                 task->tk_client->cl_prog,
1433                                 task->tk_client->cl_vers,
1434                                 task->tk_client->cl_server);
1435                 error = -EOPNOTSUPP;
1436                 goto out_err;
1437         case RPC_GARBAGE_ARGS:
1438                 dprintk("RPC: %5u %s: server saw garbage\n",
1439                                 task->tk_pid, __FUNCTION__);
1440                 break;                  /* retry */
1441         default:
1442                 dprintk("RPC: %5u %s: server accept status: %x\n",
1443                                 task->tk_pid, __FUNCTION__, n);
1444                 /* Also retry */
1445         }
1446
1447 out_garbage:
1448         task->tk_client->cl_stats->rpcgarbage++;
1449         if (task->tk_garb_retry) {
1450                 task->tk_garb_retry--;
1451                 dprintk("RPC: %5u %s: retrying\n",
1452                                 task->tk_pid, __FUNCTION__);
1453                 task->tk_action = call_bind;
1454 out_retry:
1455                 return ERR_PTR(-EAGAIN);
1456         }
1457 out_eio:
1458         error = -EIO;
1459 out_err:
1460         rpc_exit(task, error);
1461         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1462                         __FUNCTION__, error);
1463         return ERR_PTR(error);
1464 out_overflow:
1465         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1466                         __FUNCTION__);
1467         goto out_garbage;
1468 }
1469
1470 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1471 {
1472         return 0;
1473 }
1474
1475 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1476 {
1477         return 0;
1478 }
1479
1480 static struct rpc_procinfo rpcproc_null = {
1481         .p_encode = rpcproc_encode_null,
1482         .p_decode = rpcproc_decode_null,
1483 };
1484
1485 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1486 {
1487         struct rpc_message msg = {
1488                 .rpc_proc = &rpcproc_null,
1489         };
1490         int err;
1491         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1492         err = rpc_call_sync(clnt, &msg, flags);
1493         put_rpccred(msg.rpc_cred);
1494         return err;
1495 }
1496
1497 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1498 {
1499         struct rpc_message msg = {
1500                 .rpc_proc = &rpcproc_null,
1501                 .rpc_cred = cred,
1502         };
1503         struct rpc_task_setup task_setup_data = {
1504                 .rpc_client = clnt,
1505                 .rpc_message = &msg,
1506                 .callback_ops = &rpc_default_ops,
1507                 .flags = flags,
1508         };
1509         return rpc_run_task(&task_setup_data);
1510 }
1511 EXPORT_SYMBOL_GPL(rpc_call_null);
1512
1513 #ifdef RPC_DEBUG
1514 void rpc_show_tasks(void)
1515 {
1516         struct rpc_clnt *clnt;
1517         struct rpc_task *t;
1518
1519         spin_lock(&rpc_client_lock);
1520         if (list_empty(&all_clients))
1521                 goto out;
1522         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1523                 "-rpcwait -action- ---ops--\n");
1524         list_for_each_entry(clnt, &all_clients, cl_clients) {
1525                 if (list_empty(&clnt->cl_tasks))
1526                         continue;
1527                 spin_lock(&clnt->cl_lock);
1528                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1529                         const char *rpc_waitq = "none";
1530                         int proc;
1531
1532                         if (t->tk_msg.rpc_proc)
1533                                 proc = t->tk_msg.rpc_proc->p_proc;
1534                         else
1535                                 proc = -1;
1536
1537                         if (RPC_IS_QUEUED(t))
1538                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1539
1540                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1541                                 t->tk_pid, proc,
1542                                 t->tk_flags, t->tk_status,
1543                                 t->tk_client,
1544                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1545                                 t->tk_rqstp, t->tk_timeout,
1546                                 rpc_waitq,
1547                                 t->tk_action, t->tk_ops);
1548                 }
1549                 spin_unlock(&clnt->cl_lock);
1550         }
1551 out:
1552         spin_unlock(&rpc_client_lock);
1553 }
1554 #endif