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                         __func__, 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_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
  73 static __be32   *rpc_encode_header(struct rpc_task *task);
  74 static __be32   *rpc_verify_header(struct rpc_task *task);
  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(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 125 {
 126         struct rpc_program      *program = args->program;
 127         struct rpc_version      *version;
 128         struct rpc_clnt         *clnt = NULL;
 129         struct rpc_auth         *auth;
 130         int err;
 131         size_t len;
 132
 133         /* sanity check the name before trying to print it */
 134         err = -EINVAL;
 135         len = strlen(args->servername);
 136         if (len > RPC_MAXNETNAMELEN)
 137                 goto out_no_rpciod;
 138         len++;
 139
 140         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 141                         program->name, args->servername, xprt);
 142
 143         err = rpciod_up();
 144         if (err)
 145                 goto out_no_rpciod;
 146         err = -EINVAL;
 147         if (!xprt)
 148                 goto out_no_xprt;
 149
 150         if (args->version >= program->nrvers)
 151                 goto out_err;
 152         version = program->version[args->version];
 153         if (version == NULL)
 154                 goto out_err;
 155
 156         err = -ENOMEM;
 157         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 158         if (!clnt)
 159                 goto out_err;
 160         clnt->cl_parent = clnt;
 161
 162         clnt->cl_server = clnt->cl_inline_name;
 163         if (len > sizeof(clnt->cl_inline_name)) {
 164                 char *buf = kmalloc(len, GFP_KERNEL);
 165                 if (buf != NULL)
 166                         clnt->cl_server = buf;
 167                 else
 168                         len = sizeof(clnt->cl_inline_name);
 169         }
 170         strlcpy(clnt->cl_server, args->servername, len);
 171
 172         clnt->cl_xprt     = xprt;
 173         clnt->cl_procinfo = version->procs;
 174         clnt->cl_maxproc  = version->nrprocs;
 175         clnt->cl_protname = program->name;
 176         clnt->cl_prog     = program->number;
 177         clnt->cl_vers     = version->number;
 178         clnt->cl_stats    = program->stats;
 179         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 180         err = -ENOMEM;
 181         if (clnt->cl_metrics == NULL)
 182                 goto out_no_stats;
 183         clnt->cl_program  = program;
 184         INIT_LIST_HEAD(&clnt->cl_tasks);
 185         spin_lock_init(&clnt->cl_lock);
 186
 187         if (!xprt_bound(clnt->cl_xprt))
 188                 clnt->cl_autobind = 1;
 189
 190         clnt->cl_timeout = xprt->timeout;
 191         if (args->timeout != NULL) {
 192                 memcpy(&clnt->cl_timeout_default, args->timeout,
 193                                 sizeof(clnt->cl_timeout_default));
 194                 clnt->cl_timeout = &clnt->cl_timeout_default;
 195         }
 196
 197         clnt->cl_rtt = &clnt->cl_rtt_default;
 198         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 199
 200         kref_init(&clnt->cl_kref);
 201
 202         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 203         if (err < 0)
 204                 goto out_no_path;
 205
 206         auth = rpcauth_create(args->authflavor, clnt);
 207         if (IS_ERR(auth)) {
 208                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 209                                 args->authflavor);
 210                 err = PTR_ERR(auth);
 211                 goto out_no_auth;
 212         }
 213
 214         /* save the nodename */
 215         clnt->cl_nodelen = strlen(utsname()->nodename);
 216         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 217                 clnt->cl_nodelen = UNX_MAXNODENAME;
 218         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 219         rpc_register_client(clnt);
 220         return clnt;
 221
 222 out_no_auth:
 223         if (!IS_ERR(clnt->cl_dentry)) {
 224                 rpc_rmdir(clnt->cl_dentry);
 225                 rpc_put_mount();
 226         }
 227 out_no_path:
 228         rpc_free_iostats(clnt->cl_metrics);
 229 out_no_stats:
 230         if (clnt->cl_server != clnt->cl_inline_name)
 231                 kfree(clnt->cl_server);
 232         kfree(clnt);
 233 out_err:
 234         xprt_put(xprt);
 235 out_no_xprt:
 236         rpciod_down();
 237 out_no_rpciod:
 238         return ERR_PTR(err);
 239 }
 240
 241 /*
 242  * rpc_create - create an RPC client and transport with one call
 243  * @args: rpc_clnt create argument structure
 244  *
 245  * Creates and initializes an RPC transport and an RPC client.
 246  *
 247  * It can ping the server in order to determine if it is up, and to see if
 248  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 249  * this behavior so asynchronous tasks can also use rpc_create.
 250  */
 251 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 252 {
 253         struct rpc_xprt *xprt;
 254         struct rpc_clnt *clnt;
 255         struct xprt_create xprtargs = {
 256                 .ident = args->protocol,
 257                 .srcaddr = args->saddress,
 258                 .dstaddr = args->address,
 259                 .addrlen = args->addrsize,
 260         };
 261         char servername[48];
 262
 263         /*
 264          * If the caller chooses not to specify a hostname, whip
 265          * up a string representation of the passed-in address.
 266          */
 267         if (args->servername == NULL) {
 268                 servername[0] = '\0';
 269                 switch (args->address->sa_family) {
 270                 case AF_INET: {
 271                         struct sockaddr_in *sin =
 272                                         (struct sockaddr_in *)args->address;
 273                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 274                                  NIPQUAD(sin->sin_addr.s_addr));
 275                         break;
 276                 }
 277                 case AF_INET6: {
 278                         struct sockaddr_in6 *sin =
 279                                         (struct sockaddr_in6 *)args->address;
 280                         snprintf(servername, sizeof(servername), NIP6_FMT,
 281                                  NIP6(sin->sin6_addr));
 282                         break;
 283                 }
 284                 default:
 285                         /* caller wants default server name, but
 286                          * address family isn't recognized. */
 287                         return ERR_PTR(-EINVAL);
 288                 }
 289                 args->servername = servername;
 290         }
 291
 292         xprt = xprt_create_transport(&xprtargs);
 293         if (IS_ERR(xprt))
 294                 return (struct rpc_clnt *)xprt;
 295
 296         /*
 297          * By default, kernel RPC client connects from a reserved port.
 298          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 299          * but it is always enabled for rpciod, which handles the connect
 300          * operation.
 301          */
 302         xprt->resvport = 1;
 303         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 304                 xprt->resvport = 0;
 305
 306         clnt = rpc_new_client(args, xprt);
 307         if (IS_ERR(clnt))
 308                 return clnt;
 309
 310         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 311                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 312                 if (err != 0) {
 313                         rpc_shutdown_client(clnt);
 314                         return ERR_PTR(err);
 315                 }
 316         }
 317
 318         clnt->cl_softrtry = 1;
 319         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 320                 clnt->cl_softrtry = 0;
 321
 322         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 323                 clnt->cl_autobind = 1;
 324         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 325                 clnt->cl_discrtry = 1;
 326
 327         return clnt;
 328 }
 329 EXPORT_SYMBOL_GPL(rpc_create);
 330
 331 /*
 332  * This function clones the RPC client structure. It allows us to share the
 333  * same transport while varying parameters such as the authentication
 334  * flavour.
 335  */
 336 struct rpc_clnt *
 337 rpc_clone_client(struct rpc_clnt *clnt)
 338 {
 339         struct rpc_clnt *new;
 340         int err = -ENOMEM;
 341
 342         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 343         if (!new)
 344                 goto out_no_clnt;
 345         new->cl_parent = clnt;
 346         /* Turn off autobind on clones */
 347         new->cl_autobind = 0;
 348         INIT_LIST_HEAD(&new->cl_tasks);
 349         spin_lock_init(&new->cl_lock);
 350         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 351         new->cl_metrics = rpc_alloc_iostats(clnt);
 352         if (new->cl_metrics == NULL)
 353                 goto out_no_stats;
 354         kref_init(&new->cl_kref);
 355         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 356         if (err != 0)
 357                 goto out_no_path;
 358         if (new->cl_auth)
 359                 atomic_inc(&new->cl_auth->au_count);
 360         xprt_get(clnt->cl_xprt);
 361         kref_get(&clnt->cl_kref);
 362         rpc_register_client(new);
 363         rpciod_up();
 364         return new;
 365 out_no_path:
 366         rpc_free_iostats(new->cl_metrics);
 367 out_no_stats:
 368         kfree(new);
 369 out_no_clnt:
 370         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 371         return ERR_PTR(err);
 372 }
 373 EXPORT_SYMBOL_GPL(rpc_clone_client);
 374
 375 /*
 376  * Properly shut down an RPC client, terminating all outstanding
 377  * requests.
 378  */
 379 void rpc_shutdown_client(struct rpc_clnt *clnt)
 380 {
 381         dprintk("RPC:       shutting down %s client for %s\n",
 382                         clnt->cl_protname, clnt->cl_server);
 383
 384         while (!list_empty(&clnt->cl_tasks)) {
 385                 rpc_killall_tasks(clnt);
 386                 wait_event_timeout(destroy_wait,
 387                         list_empty(&clnt->cl_tasks), 1*HZ);
 388         }
 389
 390         rpc_release_client(clnt);
 391 }
 392 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 393
 394 /*
 395  * Free an RPC client
 396  */
 397 static void
 398 rpc_free_client(struct kref *kref)
 399 {
 400         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 401
 402         dprintk("RPC:       destroying %s client for %s\n",
 403                         clnt->cl_protname, clnt->cl_server);
 404         if (!IS_ERR(clnt->cl_dentry)) {
 405                 rpc_rmdir(clnt->cl_dentry);
 406                 rpc_put_mount();
 407         }
 408         if (clnt->cl_parent != clnt) {
 409                 rpc_release_client(clnt->cl_parent);
 410                 goto out_free;
 411         }
 412         if (clnt->cl_server != clnt->cl_inline_name)
 413                 kfree(clnt->cl_server);
 414 out_free:
 415         rpc_unregister_client(clnt);
 416         rpc_free_iostats(clnt->cl_metrics);
 417         clnt->cl_metrics = NULL;
 418         xprt_put(clnt->cl_xprt);
 419         rpciod_down();
 420         kfree(clnt);
 421 }
 422
 423 /*
 424  * Free an RPC client
 425  */
 426 static void
 427 rpc_free_auth(struct kref *kref)
 428 {
 429         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 430
 431         if (clnt->cl_auth == NULL) {
 432                 rpc_free_client(kref);
 433                 return;
 434         }
 435
 436         /*
 437          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 438          *       release remaining GSS contexts. This mechanism ensures
 439          *       that it can do so safely.
 440          */
 441         kref_init(kref);
 442         rpcauth_release(clnt->cl_auth);
 443         clnt->cl_auth = NULL;
 444         kref_put(kref, rpc_free_client);
 445 }
 446
 447 /*
 448  * Release reference to the RPC client
 449  */
 450 void
 451 rpc_release_client(struct rpc_clnt *clnt)
 452 {
 453         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 454
 455         if (list_empty(&clnt->cl_tasks))
 456                 wake_up(&destroy_wait);
 457         kref_put(&clnt->cl_kref, rpc_free_auth);
 458 }
 459
 460 /**
 461  * rpc_bind_new_program - bind a new RPC program to an existing client
 462  * @old: old rpc_client
 463  * @program: rpc program to set
 464  * @vers: rpc program version
 465  *
 466  * Clones the rpc client and sets up a new RPC program. This is mainly
 467  * of use for enabling different RPC programs to share the same transport.
 468  * The Sun NFSv2/v3 ACL protocol can do this.
 469  */
 470 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 471                                       struct rpc_program *program,
 472                                       u32 vers)
 473 {
 474         struct rpc_clnt *clnt;
 475         struct rpc_version *version;
 476         int err;
 477
 478         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 479         version = program->version[vers];
 480         clnt = rpc_clone_client(old);
 481         if (IS_ERR(clnt))
 482                 goto out;
 483         clnt->cl_procinfo = version->procs;
 484         clnt->cl_maxproc  = version->nrprocs;
 485         clnt->cl_protname = program->name;
 486         clnt->cl_prog     = program->number;
 487         clnt->cl_vers     = version->number;
 488         clnt->cl_stats    = program->stats;
 489         err = rpc_ping(clnt, RPC_TASK_SOFT);
 490         if (err != 0) {
 491                 rpc_shutdown_client(clnt);
 492                 clnt = ERR_PTR(err);
 493         }
 494 out:
 495         return clnt;
 496 }
 497 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 498
 499 /*
 500  * Default callback for async RPC calls
 501  */
 502 static void
 503 rpc_default_callback(struct rpc_task *task, void *data)
 504 {
 505 }
 506
 507 static const struct rpc_call_ops rpc_default_ops = {
 508         .rpc_call_done = rpc_default_callback,
 509 };
 510
 511 /**
 512  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 513  * @task_setup_data: pointer to task initialisation data
 514  */
 515 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 516 {
 517         struct rpc_task *task, *ret;
 518
 519         task = rpc_new_task(task_setup_data);
 520         if (task == NULL) {
 521                 rpc_release_calldata(task_setup_data->callback_ops,
 522                                 task_setup_data->callback_data);
 523                 ret = ERR_PTR(-ENOMEM);
 524                 goto out;
 525         }
 526
 527         if (task->tk_status != 0) {
 528                 ret = ERR_PTR(task->tk_status);
 529                 rpc_put_task(task);
 530                 goto out;
 531         }
 532         atomic_inc(&task->tk_count);
 533         rpc_execute(task);
 534         ret = task;
 535 out:
 536         return ret;
 537 }
 538 EXPORT_SYMBOL_GPL(rpc_run_task);
 539
 540 /**
 541  * rpc_call_sync - Perform a synchronous RPC call
 542  * @clnt: pointer to RPC client
 543  * @msg: RPC call parameters
 544  * @flags: RPC call flags
 545  */
 546 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 547 {
 548         struct rpc_task *task;
 549         struct rpc_task_setup task_setup_data = {
 550                 .rpc_client = clnt,
 551                 .rpc_message = msg,
 552                 .callback_ops = &rpc_default_ops,
 553                 .flags = flags,
 554         };
 555         int status;
 556
 557         BUG_ON(flags & RPC_TASK_ASYNC);
 558
 559         task = rpc_run_task(&task_setup_data);
 560         if (IS_ERR(task))
 561                 return PTR_ERR(task);
 562         status = task->tk_status;
 563         rpc_put_task(task);
 564         return status;
 565 }
 566 EXPORT_SYMBOL_GPL(rpc_call_sync);
 567
 568 /**
 569  * rpc_call_async - Perform an asynchronous RPC call
 570  * @clnt: pointer to RPC client
 571  * @msg: RPC call parameters
 572  * @flags: RPC call flags
 573  * @tk_ops: RPC call ops
 574  * @data: user call data
 575  */
 576 int
 577 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 578                const struct rpc_call_ops *tk_ops, void *data)
 579 {
 580         struct rpc_task *task;
 581         struct rpc_task_setup task_setup_data = {
 582                 .rpc_client = clnt,
 583                 .rpc_message = msg,
 584                 .callback_ops = tk_ops,
 585                 .callback_data = data,
 586                 .flags = flags|RPC_TASK_ASYNC,
 587         };
 588
 589         task = rpc_run_task(&task_setup_data);
 590         if (IS_ERR(task))
 591                 return PTR_ERR(task);
 592         rpc_put_task(task);
 593         return 0;
 594 }
 595 EXPORT_SYMBOL_GPL(rpc_call_async);
 596
 597 void
 598 rpc_call_start(struct rpc_task *task)
 599 {
 600         task->tk_action = call_start;
 601 }
 602 EXPORT_SYMBOL_GPL(rpc_call_start);
 603
 604 /**
 605  * rpc_peeraddr - extract remote peer address from clnt's xprt
 606  * @clnt: RPC client structure
 607  * @buf: target buffer
 608  * @bufsize: length of target buffer
 609  *
 610  * Returns the number of bytes that are actually in the stored address.
 611  */
 612 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 613 {
 614         size_t bytes;
 615         struct rpc_xprt *xprt = clnt->cl_xprt;
 616
 617         bytes = sizeof(xprt->addr);
 618         if (bytes > bufsize)
 619                 bytes = bufsize;
 620         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 621         return xprt->addrlen;
 622 }
 623 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 624
 625 /**
 626  * rpc_peeraddr2str - return remote peer address in printable format
 627  * @clnt: RPC client structure
 628  * @format: address format
 629  *
 630  */
 631 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 632                              enum rpc_display_format_t format)
 633 {
 634         struct rpc_xprt *xprt = clnt->cl_xprt;
 635
 636         if (xprt->address_strings[format] != NULL)
 637                 return xprt->address_strings[format];
 638         else
 639                 return "unprintable";
 640 }
 641 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 642
 643 void
 644 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 645 {
 646         struct rpc_xprt *xprt = clnt->cl_xprt;
 647         if (xprt->ops->set_buffer_size)
 648                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 649 }
 650 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 651
 652 /*
 653  * Return size of largest payload RPC client can support, in bytes
 654  *
 655  * For stream transports, this is one RPC record fragment (see RFC
 656  * 1831), as we don't support multi-record requests yet.  For datagram
 657  * transports, this is the size of an IP packet minus the IP, UDP, and
 658  * RPC header sizes.
 659  */
 660 size_t rpc_max_payload(struct rpc_clnt *clnt)
 661 {
 662         return clnt->cl_xprt->max_payload;
 663 }
 664 EXPORT_SYMBOL_GPL(rpc_max_payload);
 665
 666 /**
 667  * rpc_force_rebind - force transport to check that remote port is unchanged
 668  * @clnt: client to rebind
 669  *
 670  */
 671 void rpc_force_rebind(struct rpc_clnt *clnt)
 672 {
 673         if (clnt->cl_autobind)
 674                 xprt_clear_bound(clnt->cl_xprt);
 675 }
 676 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 677
 678 /*
 679  * Restart an (async) RPC call. Usually called from within the
 680  * exit handler.
 681  */
 682 void
 683 rpc_restart_call(struct rpc_task *task)
 684 {
 685         if (RPC_ASSASSINATED(task))
 686                 return;
 687
 688         task->tk_action = call_start;
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_restart_call);
 691
 692 #ifdef RPC_DEBUG
 693 static const char *rpc_proc_name(const struct rpc_task *task)
 694 {
 695         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 696
 697         if (proc) {
 698                 if (proc->p_name)
 699                         return proc->p_name;
 700                 else
 701                         return "NULL";
 702         } else
 703                 return "no proc";
 704 }
 705 #endif
 706
 707 /*
 708  * 0.  Initial state
 709  *
 710  *     Other FSM states can be visited zero or more times, but
 711  *     this state is visited exactly once for each RPC.
 712  */
 713 static void
 714 call_start(struct rpc_task *task)
 715 {
 716         struct rpc_clnt *clnt = task->tk_client;
 717
 718         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 719                         clnt->cl_protname, clnt->cl_vers,
 720                         rpc_proc_name(task),
 721                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 722
 723         /* Increment call count */
 724         task->tk_msg.rpc_proc->p_count++;
 725         clnt->cl_stats->rpccnt++;
 726         task->tk_action = call_reserve;
 727 }
 728
 729 /*
 730  * 1.   Reserve an RPC call slot
 731  */
 732 static void
 733 call_reserve(struct rpc_task *task)
 734 {
 735         dprint_status(task);
 736
 737         if (!rpcauth_uptodatecred(task)) {
 738                 task->tk_action = call_refresh;
 739                 return;
 740         }
 741
 742         task->tk_status  = 0;
 743         task->tk_action  = call_reserveresult;
 744         xprt_reserve(task);
 745 }
 746
 747 /*
 748  * 1b.  Grok the result of xprt_reserve()
 749  */
 750 static void
 751 call_reserveresult(struct rpc_task *task)
 752 {
 753         int status = task->tk_status;
 754
 755         dprint_status(task);
 756
 757         /*
 758          * After a call to xprt_reserve(), we must have either
 759          * a request slot or else an error status.
 760          */
 761         task->tk_status = 0;
 762         if (status >= 0) {
 763                 if (task->tk_rqstp) {
 764                         task->tk_action = call_allocate;
 765                         return;
 766                 }
 767
 768                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 769                                 __func__, status);
 770                 rpc_exit(task, -EIO);
 771                 return;
 772         }
 773
 774         /*
 775          * Even though there was an error, we may have acquired
 776          * a request slot somehow.  Make sure not to leak it.
 777          */
 778         if (task->tk_rqstp) {
 779                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 780                                 __func__, status);
 781                 xprt_release(task);
 782         }
 783
 784         switch (status) {
 785         case -EAGAIN:   /* woken up; retry */
 786                 task->tk_action = call_reserve;
 787                 return;
 788         case -EIO:      /* probably a shutdown */
 789                 break;
 790         default:
 791                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 792                                 __func__, status);
 793                 break;
 794         }
 795         rpc_exit(task, status);
 796 }
 797
 798 /*
 799  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 800  *      (Note: buffer memory is freed in xprt_release).
 801  */
 802 static void
 803 call_allocate(struct rpc_task *task)
 804 {
 805         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 806         struct rpc_rqst *req = task->tk_rqstp;
 807         struct rpc_xprt *xprt = task->tk_xprt;
 808         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 809
 810         dprint_status(task);
 811
 812         task->tk_status = 0;
 813         task->tk_action = call_bind;
 814
 815         if (req->rq_buffer)
 816                 return;
 817
 818         if (proc->p_proc != 0) {
 819                 BUG_ON(proc->p_arglen == 0);
 820                 if (proc->p_decode != NULL)
 821                         BUG_ON(proc->p_replen == 0);
 822         }
 823
 824         /*
 825          * Calculate the size (in quads) of the RPC call
 826          * and reply headers, and convert both values
 827          * to byte sizes.
 828          */
 829         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 830         req->rq_callsize <<= 2;
 831         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 832         req->rq_rcvsize <<= 2;
 833
 834         req->rq_buffer = xprt->ops->buf_alloc(task,
 835                                         req->rq_callsize + req->rq_rcvsize);
 836         if (req->rq_buffer != NULL)
 837                 return;
 838
 839         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 840
 841         if (RPC_IS_ASYNC(task) || !signalled()) {
 842                 task->tk_action = call_allocate;
 843                 rpc_delay(task, HZ>>4);
 844                 return;
 845         }
 846
 847         rpc_exit(task, -ERESTARTSYS);
 848 }
 849
 850 static inline int
 851 rpc_task_need_encode(struct rpc_task *task)
 852 {
 853         return task->tk_rqstp->rq_snd_buf.len == 0;
 854 }
 855
 856 static inline void
 857 rpc_task_force_reencode(struct rpc_task *task)
 858 {
 859         task->tk_rqstp->rq_snd_buf.len = 0;
 860 }
 861
 862 static inline void
 863 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 864 {
 865         buf->head[0].iov_base = start;
 866         buf->head[0].iov_len = len;
 867         buf->tail[0].iov_len = 0;
 868         buf->page_len = 0;
 869         buf->flags = 0;
 870         buf->len = 0;
 871         buf->buflen = len;
 872 }
 873
 874 /*
 875  * 3.   Encode arguments of an RPC call
 876  */
 877 static void
 878 rpc_xdr_encode(struct rpc_task *task)
 879 {
 880         struct rpc_rqst *req = task->tk_rqstp;
 881         kxdrproc_t      encode;
 882         __be32          *p;
 883
 884         dprint_status(task);
 885
 886         rpc_xdr_buf_init(&req->rq_snd_buf,
 887                          req->rq_buffer,
 888                          req->rq_callsize);
 889         rpc_xdr_buf_init(&req->rq_rcv_buf,
 890                          (char *)req->rq_buffer + req->rq_callsize,
 891                          req->rq_rcvsize);
 892
 893         p = rpc_encode_header(task);
 894         if (p == NULL) {
 895                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 896                 rpc_exit(task, -EIO);
 897                 return;
 898         }
 899
 900         encode = task->tk_msg.rpc_proc->p_encode;
 901         if (encode == NULL)
 902                 return;
 903
 904         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 905                         task->tk_msg.rpc_argp);
 906 }
 907
 908 /*
 909  * 4.   Get the server port number if not yet set
 910  */
 911 static void
 912 call_bind(struct rpc_task *task)
 913 {
 914         struct rpc_xprt *xprt = task->tk_xprt;
 915
 916         dprint_status(task);
 917
 918         task->tk_action = call_connect;
 919         if (!xprt_bound(xprt)) {
 920                 task->tk_action = call_bind_status;
 921                 task->tk_timeout = xprt->bind_timeout;
 922                 xprt->ops->rpcbind(task);
 923         }
 924 }
 925
 926 /*
 927  * 4a.  Sort out bind result
 928  */
 929 static void
 930 call_bind_status(struct rpc_task *task)
 931 {
 932         int status = -EIO;
 933
 934         if (task->tk_status >= 0) {
 935                 dprint_status(task);
 936                 task->tk_status = 0;
 937                 task->tk_action = call_connect;
 938                 return;
 939         }
 940
 941         switch (task->tk_status) {
 942         case -EAGAIN:
 943                 dprintk("RPC: %5u rpcbind waiting for another request "
 944                                 "to finish\n", task->tk_pid);
 945                 /* avoid busy-waiting here -- could be a network outage. */
 946                 rpc_delay(task, 5*HZ);
 947                 goto retry_timeout;
 948         case -EACCES:
 949                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 950                                 "unavailable\n", task->tk_pid);
 951                 /* fail immediately if this is an RPC ping */
 952                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 953                         status = -EOPNOTSUPP;
 954                         break;
 955                 }
 956                 rpc_delay(task, 3*HZ);
 957                 goto retry_timeout;
 958         case -ETIMEDOUT:
 959                 dprintk("RPC: %5u rpcbind request timed out\n",
 960                                 task->tk_pid);
 961                 goto retry_timeout;
 962         case -EPFNOSUPPORT:
 963                 /* server doesn't support any rpcbind version we know of */
 964                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 965                                 task->tk_pid);
 966                 break;
 967         case -EPROTONOSUPPORT:
 968                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 969                                 task->tk_pid);
 970                 task->tk_status = 0;
 971                 task->tk_action = call_bind;
 972                 return;
 973         default:
 974                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 975                                 task->tk_pid, -task->tk_status);
 976         }
 977
 978         rpc_exit(task, status);
 979         return;
 980
 981 retry_timeout:
 982         task->tk_action = call_timeout;
 983 }
 984
 985 /*
 986  * 4b.  Connect to the RPC server
 987  */
 988 static void
 989 call_connect(struct rpc_task *task)
 990 {
 991         struct rpc_xprt *xprt = task->tk_xprt;
 992
 993         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
 994                         task->tk_pid, xprt,
 995                         (xprt_connected(xprt) ? "is" : "is not"));
 996
 997         task->tk_action = call_transmit;
 998         if (!xprt_connected(xprt)) {
 999                 task->tk_action = call_connect_status;
1000                 if (task->tk_status < 0)
1001                         return;
1002                 xprt_connect(task);
1003         }
1004 }
1005
1006 /*
1007  * 4c.  Sort out connect result
1008  */
1009 static void
1010 call_connect_status(struct rpc_task *task)
1011 {
1012         struct rpc_clnt *clnt = task->tk_client;
1013         int status = task->tk_status;
1014
1015         dprint_status(task);
1016
1017         task->tk_status = 0;
1018         if (status >= 0) {
1019                 clnt->cl_stats->netreconn++;
1020                 task->tk_action = call_transmit;
1021                 return;
1022         }
1023
1024         /* Something failed: remote service port may have changed */
1025         rpc_force_rebind(clnt);
1026
1027         switch (status) {
1028         case -ENOTCONN:
1029         case -EAGAIN:
1030                 task->tk_action = call_bind;
1031                 if (!RPC_IS_SOFT(task))
1032                         return;
1033                 /* if soft mounted, test if we've timed out */
1034         case -ETIMEDOUT:
1035                 task->tk_action = call_timeout;
1036                 return;
1037         }
1038         rpc_exit(task, -EIO);
1039 }
1040
1041 /*
1042  * 5.   Transmit the RPC request, and wait for reply
1043  */
1044 static void
1045 call_transmit(struct rpc_task *task)
1046 {
1047         dprint_status(task);
1048
1049         task->tk_action = call_status;
1050         if (task->tk_status < 0)
1051                 return;
1052         task->tk_status = xprt_prepare_transmit(task);
1053         if (task->tk_status != 0)
1054                 return;
1055         task->tk_action = call_transmit_status;
1056         /* Encode here so that rpcsec_gss can use correct sequence number. */
1057         if (rpc_task_need_encode(task)) {
1058                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1059                 rpc_xdr_encode(task);
1060                 /* Did the encode result in an error condition? */
1061                 if (task->tk_status != 0) {
1062                         /* Was the error nonfatal? */
1063                         if (task->tk_status == -EAGAIN)
1064                                 rpc_delay(task, HZ >> 4);
1065                         else
1066                                 rpc_exit(task, task->tk_status);
1067                         return;
1068                 }
1069         }
1070         xprt_transmit(task);
1071         if (task->tk_status < 0)
1072                 return;
1073         /*
1074          * On success, ensure that we call xprt_end_transmit() before sleeping
1075          * in order to allow access to the socket to other RPC requests.
1076          */
1077         call_transmit_status(task);
1078         if (task->tk_msg.rpc_proc->p_decode != NULL)
1079                 return;
1080         task->tk_action = rpc_exit_task;
1081         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1082 }
1083
1084 /*
1085  * 5a.  Handle cleanup after a transmission
1086  */
1087 static void
1088 call_transmit_status(struct rpc_task *task)
1089 {
1090         task->tk_action = call_status;
1091         /*
1092          * Special case: if we've been waiting on the socket's write_space()
1093          * callback, then don't call xprt_end_transmit().
1094          */
1095         if (task->tk_status == -EAGAIN)
1096                 return;
1097         xprt_end_transmit(task);
1098         rpc_task_force_reencode(task);
1099 }
1100
1101 /*
1102  * 6.   Sort out the RPC call status
1103  */
1104 static void
1105 call_status(struct rpc_task *task)
1106 {
1107         struct rpc_clnt *clnt = task->tk_client;
1108         struct rpc_rqst *req = task->tk_rqstp;
1109         int             status;
1110
1111         if (req->rq_received > 0 && !req->rq_bytes_sent)
1112                 task->tk_status = req->rq_received;
1113
1114         dprint_status(task);
1115
1116         status = task->tk_status;
1117         if (status >= 0) {
1118                 task->tk_action = call_decode;
1119                 return;
1120         }
1121
1122         task->tk_status = 0;
1123         switch(status) {
1124         case -EHOSTDOWN:
1125         case -EHOSTUNREACH:
1126         case -ENETUNREACH:
1127                 /*
1128                  * Delay any retries for 3 seconds, then handle as if it
1129                  * were a timeout.
1130                  */
1131                 rpc_delay(task, 3*HZ);
1132         case -ETIMEDOUT:
1133                 task->tk_action = call_timeout;
1134                 if (task->tk_client->cl_discrtry)
1135                         xprt_conditional_disconnect(task->tk_xprt,
1136                                         req->rq_connect_cookie);
1137                 break;
1138         case -ECONNREFUSED:
1139         case -ENOTCONN:
1140                 rpc_force_rebind(clnt);
1141                 task->tk_action = call_bind;
1142                 break;
1143         case -EAGAIN:
1144                 task->tk_action = call_transmit;
1145                 break;
1146         case -EIO:
1147                 /* shutdown or soft timeout */
1148                 rpc_exit(task, status);
1149                 break;
1150         default:
1151                 printk("%s: RPC call returned error %d\n",
1152                                clnt->cl_protname, -status);
1153                 rpc_exit(task, status);
1154         }
1155 }
1156
1157 /*
1158  * 6a.  Handle RPC timeout
1159  *      We do not release the request slot, so we keep using the
1160  *      same XID for all retransmits.
1161  */
1162 static void
1163 call_timeout(struct rpc_task *task)
1164 {
1165         struct rpc_clnt *clnt = task->tk_client;
1166
1167         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1168                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1169                 goto retry;
1170         }
1171
1172         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1173         task->tk_timeouts++;
1174
1175         if (RPC_IS_SOFT(task)) {
1176                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1177                                 clnt->cl_protname, clnt->cl_server);
1178                 rpc_exit(task, -EIO);
1179                 return;
1180         }
1181
1182         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1183                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1184                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1185                         clnt->cl_protname, clnt->cl_server);
1186         }
1187         rpc_force_rebind(clnt);
1188         /*
1189          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1190          * event? RFC2203 requires the server to drop all such requests.
1191          */
1192         rpcauth_invalcred(task);
1193
1194 retry:
1195         clnt->cl_stats->rpcretrans++;
1196         task->tk_action = call_bind;
1197         task->tk_status = 0;
1198 }
1199
1200 /*
1201  * 7.   Decode the RPC reply
1202  */
1203 static void
1204 call_decode(struct rpc_task *task)
1205 {
1206         struct rpc_clnt *clnt = task->tk_client;
1207         struct rpc_rqst *req = task->tk_rqstp;
1208         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1209         __be32          *p;
1210
1211         dprintk("RPC: %5u call_decode (status %d)\n",
1212                         task->tk_pid, task->tk_status);
1213
1214         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1215                 printk(KERN_NOTICE "%s: server %s OK\n",
1216                         clnt->cl_protname, clnt->cl_server);
1217                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1218         }
1219
1220         /*
1221          * Ensure that we see all writes made by xprt_complete_rqst()
1222          * before it changed req->rq_received.
1223          */
1224         smp_rmb();
1225         req->rq_rcv_buf.len = req->rq_private_buf.len;
1226
1227         /* Check that the softirq receive buffer is valid */
1228         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1229                                 sizeof(req->rq_rcv_buf)) != 0);
1230
1231         if (req->rq_rcv_buf.len < 12) {
1232                 if (!RPC_IS_SOFT(task)) {
1233                         task->tk_action = call_bind;
1234                         clnt->cl_stats->rpcretrans++;
1235                         goto out_retry;
1236                 }
1237                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1238                                 clnt->cl_protname, task->tk_status);
1239                 task->tk_action = call_timeout;
1240                 goto out_retry;
1241         }
1242
1243         p = rpc_verify_header(task);
1244         if (IS_ERR(p)) {
1245                 if (p == ERR_PTR(-EAGAIN))
1246                         goto out_retry;
1247                 return;
1248         }
1249
1250         task->tk_action = rpc_exit_task;
1251
1252         if (decode) {
1253                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1254                                                       task->tk_msg.rpc_resp);
1255         }
1256         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1257                         task->tk_status);
1258         return;
1259 out_retry:
1260         task->tk_status = 0;
1261         /* Note: rpc_verify_header() may have freed the RPC slot */
1262         if (task->tk_rqstp == req) {
1263                 req->rq_received = req->rq_rcv_buf.len = 0;
1264                 if (task->tk_client->cl_discrtry)
1265                         xprt_conditional_disconnect(task->tk_xprt,
1266                                         req->rq_connect_cookie);
1267         }
1268 }
1269
1270 /*
1271  * 8.   Refresh the credentials if rejected by the server
1272  */
1273 static void
1274 call_refresh(struct rpc_task *task)
1275 {
1276         dprint_status(task);
1277
1278         task->tk_action = call_refreshresult;
1279         task->tk_status = 0;
1280         task->tk_client->cl_stats->rpcauthrefresh++;
1281         rpcauth_refreshcred(task);
1282 }
1283
1284 /*
1285  * 8a.  Process the results of a credential refresh
1286  */
1287 static void
1288 call_refreshresult(struct rpc_task *task)
1289 {
1290         int status = task->tk_status;
1291
1292         dprint_status(task);
1293
1294         task->tk_status = 0;
1295         task->tk_action = call_reserve;
1296         if (status >= 0 && rpcauth_uptodatecred(task))
1297                 return;
1298         if (status == -EACCES) {
1299                 rpc_exit(task, -EACCES);
1300                 return;
1301         }
1302         task->tk_action = call_refresh;
1303         if (status != -ETIMEDOUT)
1304                 rpc_delay(task, 3*HZ);
1305         return;
1306 }
1307
1308 static __be32 *
1309 rpc_encode_header(struct rpc_task *task)
1310 {
1311         struct rpc_clnt *clnt = task->tk_client;
1312         struct rpc_rqst *req = task->tk_rqstp;
1313         __be32          *p = req->rq_svec[0].iov_base;
1314
1315         /* FIXME: check buffer size? */
1316
1317         p = xprt_skip_transport_header(task->tk_xprt, p);
1318         *p++ = req->rq_xid;             /* XID */
1319         *p++ = htonl(RPC_CALL);         /* CALL */
1320         *p++ = htonl(RPC_VERSION);      /* RPC version */
1321         *p++ = htonl(clnt->cl_prog);    /* program number */
1322         *p++ = htonl(clnt->cl_vers);    /* program version */
1323         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1324         p = rpcauth_marshcred(task, p);
1325         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1326         return p;
1327 }
1328
1329 static __be32 *
1330 rpc_verify_header(struct rpc_task *task)
1331 {
1332         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1333         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1334         __be32  *p = iov->iov_base;
1335         u32 n;
1336         int error = -EACCES;
1337
1338         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1339                 /* RFC-1014 says that the representation of XDR data must be a
1340                  * multiple of four bytes
1341                  * - if it isn't pointer subtraction in the NFS client may give
1342                  *   undefined results
1343                  */
1344                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1345                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1346                        task->tk_rqstp->rq_rcv_buf.len);
1347                 goto out_eio;
1348         }
1349         if ((len -= 3) < 0)
1350                 goto out_overflow;
1351         p += 1; /* skip XID */
1352
1353         if ((n = ntohl(*p++)) != RPC_REPLY) {
1354                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1355                                 task->tk_pid, __func__, n);
1356                 goto out_garbage;
1357         }
1358         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1359                 if (--len < 0)
1360                         goto out_overflow;
1361                 switch ((n = ntohl(*p++))) {
1362                         case RPC_AUTH_ERROR:
1363                                 break;
1364                         case RPC_MISMATCH:
1365                                 dprintk("RPC: %5u %s: RPC call version "
1366                                                 "mismatch!\n",
1367                                                 task->tk_pid, __func__);
1368                                 error = -EPROTONOSUPPORT;
1369                                 goto out_err;
1370                         default:
1371                                 dprintk("RPC: %5u %s: RPC call rejected, "
1372                                                 "unknown error: %x\n",
1373                                                 task->tk_pid, __func__, n);
1374                                 goto out_eio;
1375                 }
1376                 if (--len < 0)
1377                         goto out_overflow;
1378                 switch ((n = ntohl(*p++))) {
1379                 case RPC_AUTH_REJECTEDCRED:
1380                 case RPC_AUTH_REJECTEDVERF:
1381                 case RPCSEC_GSS_CREDPROBLEM:
1382                 case RPCSEC_GSS_CTXPROBLEM:
1383                         if (!task->tk_cred_retry)
1384                                 break;
1385                         task->tk_cred_retry--;
1386                         dprintk("RPC: %5u %s: retry stale creds\n",
1387                                         task->tk_pid, __func__);
1388                         rpcauth_invalcred(task);
1389                         /* Ensure we obtain a new XID! */
1390                         xprt_release(task);
1391                         task->tk_action = call_refresh;
1392                         goto out_retry;
1393                 case RPC_AUTH_BADCRED:
1394                 case RPC_AUTH_BADVERF:
1395                         /* possibly garbled cred/verf? */
1396                         if (!task->tk_garb_retry)
1397                                 break;
1398                         task->tk_garb_retry--;
1399                         dprintk("RPC: %5u %s: retry garbled creds\n",
1400                                         task->tk_pid, __func__);
1401                         task->tk_action = call_bind;
1402                         goto out_retry;
1403                 case RPC_AUTH_TOOWEAK:
1404                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1405                                "authentication.\n", task->tk_client->cl_server);
1406                         break;
1407                 default:
1408                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1409                                         task->tk_pid, __func__, n);
1410                         error = -EIO;
1411                 }
1412                 dprintk("RPC: %5u %s: call rejected %d\n",
1413                                 task->tk_pid, __func__, n);
1414                 goto out_err;
1415         }
1416         if (!(p = rpcauth_checkverf(task, p))) {
1417                 dprintk("RPC: %5u %s: auth check failed\n",
1418                                 task->tk_pid, __func__);
1419                 goto out_garbage;               /* bad verifier, retry */
1420         }
1421         len = p - (__be32 *)iov->iov_base - 1;
1422         if (len < 0)
1423                 goto out_overflow;
1424         switch ((n = ntohl(*p++))) {
1425         case RPC_SUCCESS:
1426                 return p;
1427         case RPC_PROG_UNAVAIL:
1428                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1429                                 task->tk_pid, __func__,
1430                                 (unsigned int)task->tk_client->cl_prog,
1431                                 task->tk_client->cl_server);
1432                 error = -EPFNOSUPPORT;
1433                 goto out_err;
1434         case RPC_PROG_MISMATCH:
1435                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1436                                 "server %s\n", task->tk_pid, __func__,
1437                                 (unsigned int)task->tk_client->cl_prog,
1438                                 (unsigned int)task->tk_client->cl_vers,
1439                                 task->tk_client->cl_server);
1440                 error = -EPROTONOSUPPORT;
1441                 goto out_err;
1442         case RPC_PROC_UNAVAIL:
1443                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1444                                 "version %u on server %s\n",
1445                                 task->tk_pid, __func__,
1446                                 rpc_proc_name(task),
1447                                 task->tk_client->cl_prog,
1448                                 task->tk_client->cl_vers,
1449                                 task->tk_client->cl_server);
1450                 error = -EOPNOTSUPP;
1451                 goto out_err;
1452         case RPC_GARBAGE_ARGS:
1453                 dprintk("RPC: %5u %s: server saw garbage\n",
1454                                 task->tk_pid, __func__);
1455                 break;                  /* retry */
1456         default:
1457                 dprintk("RPC: %5u %s: server accept status: %x\n",
1458                                 task->tk_pid, __func__, n);
1459                 /* Also retry */
1460         }
1461
1462 out_garbage:
1463         task->tk_client->cl_stats->rpcgarbage++;
1464         if (task->tk_garb_retry) {
1465                 task->tk_garb_retry--;
1466                 dprintk("RPC: %5u %s: retrying\n",
1467                                 task->tk_pid, __func__);
1468                 task->tk_action = call_bind;
1469 out_retry:
1470                 return ERR_PTR(-EAGAIN);
1471         }
1472 out_eio:
1473         error = -EIO;
1474 out_err:
1475         rpc_exit(task, error);
1476         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1477                         __func__, error);
1478         return ERR_PTR(error);
1479 out_overflow:
1480         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1481                         __func__);
1482         goto out_garbage;
1483 }
1484
1485 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1486 {
1487         return 0;
1488 }
1489
1490 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1491 {
1492         return 0;
1493 }
1494
1495 static struct rpc_procinfo rpcproc_null = {
1496         .p_encode = rpcproc_encode_null,
1497         .p_decode = rpcproc_decode_null,
1498 };
1499
1500 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1501 {
1502         struct rpc_message msg = {
1503                 .rpc_proc = &rpcproc_null,
1504         };
1505         int err;
1506         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1507         err = rpc_call_sync(clnt, &msg, flags);
1508         put_rpccred(msg.rpc_cred);
1509         return err;
1510 }
1511
1512 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1513 {
1514         struct rpc_message msg = {
1515                 .rpc_proc = &rpcproc_null,
1516                 .rpc_cred = cred,
1517         };
1518         struct rpc_task_setup task_setup_data = {
1519                 .rpc_client = clnt,
1520                 .rpc_message = &msg,
1521                 .callback_ops = &rpc_default_ops,
1522                 .flags = flags,
1523         };
1524         return rpc_run_task(&task_setup_data);
1525 }
1526 EXPORT_SYMBOL_GPL(rpc_call_null);
1527
1528 #ifdef RPC_DEBUG
1529 static void rpc_show_header(void)
1530 {
1531         printk(KERN_INFO "-pid- proc flgs status -client- -prog- --rqstp- "
1532                 "-timeout -rpcwait -action- ---ops--\n");
1533 }
1534
1535 void rpc_show_tasks(void)
1536 {
1537         struct rpc_clnt *clnt;
1538         struct rpc_task *t;
1539         int header = 0;
1540
1541         spin_lock(&rpc_client_lock);
1542         list_for_each_entry(clnt, &all_clients, cl_clients) {
1543                 spin_lock(&clnt->cl_lock);
1544                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1545                         const char *rpc_waitq = "none";
1546                         int proc;
1547
1548                         if (!header) {
1549                                 rpc_show_header();
1550                                 header++;
1551                         }
1552
1553                         if (t->tk_msg.rpc_proc)
1554                                 proc = t->tk_msg.rpc_proc->p_proc;
1555                         else
1556                                 proc = -1;
1557
1558                         if (RPC_IS_QUEUED(t))
1559                                 rpc_waitq = rpc_qname(t->tk_waitqueue);
1560
1561                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1562                                 t->tk_pid, proc,
1563                                 t->tk_flags, t->tk_status,
1564                                 t->tk_client,
1565                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1566                                 t->tk_rqstp, t->tk_timeout,
1567                                 rpc_waitq,
1568                                 t->tk_action, t->tk_ops);
1569                 }
1570                 spin_unlock(&clnt->cl_lock);
1571         }
1572         spin_unlock(&rpc_client_lock);
1573 }
1574 #endif