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   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/utsname.h>
  32 #include <linux/workqueue.h>
  33
  34 #include <linux/sunrpc/clnt.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36 #include <linux/sunrpc/metrics.h>
  37
  38
  39 #ifdef RPC_DEBUG
  40 # define RPCDBG_FACILITY        RPCDBG_CALL
  41 #endif
  42
  43 #define dprint_status(t)                                        \
  44         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  45                         __FUNCTION__, t->tk_status)
  46
  47 /*
  48  * All RPC clients are linked into this list
  49  */
  50 static LIST_HEAD(all_clients);
  51 static DEFINE_SPINLOCK(rpc_client_lock);
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  54
  55
  56 static void     call_start(struct rpc_task *task);
  57 static void     call_reserve(struct rpc_task *task);
  58 static void     call_reserveresult(struct rpc_task *task);
  59 static void     call_allocate(struct rpc_task *task);
  60 static void     call_encode(struct rpc_task *task);
  61 static void     call_decode(struct rpc_task *task);
  62 static void     call_bind(struct rpc_task *task);
  63 static void     call_bind_status(struct rpc_task *task);
  64 static void     call_transmit(struct rpc_task *task);
  65 static void     call_status(struct rpc_task *task);
  66 static void     call_transmit_status(struct rpc_task *task);
  67 static void     call_refresh(struct rpc_task *task);
  68 static void     call_refreshresult(struct rpc_task *task);
  69 static void     call_timeout(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72 static __be32 * call_header(struct rpc_task *task);
  73 static __be32 * call_verify(struct rpc_task *task);
  74
  75 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  76
  77 static void rpc_register_client(struct rpc_clnt *clnt)
  78 {
  79         spin_lock(&rpc_client_lock);
  80         list_add(&clnt->cl_clients, &all_clients);
  81         spin_unlock(&rpc_client_lock);
  82 }
  83
  84 static void rpc_unregister_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_del(&clnt->cl_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static int
  92 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  93 {
  94         static uint32_t clntid;
  95         int error;
  96
  97         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  98         clnt->cl_dentry = ERR_PTR(-ENOENT);
  99         if (dir_name == NULL)
 100                 return 0;
 101
 102         clnt->cl_vfsmnt = rpc_get_mount();
 103         if (IS_ERR(clnt->cl_vfsmnt))
 104                 return PTR_ERR(clnt->cl_vfsmnt);
 105
 106         for (;;) {
 107                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 108                                 "%s/clnt%x", dir_name,
 109                                 (unsigned int)clntid++);
 110                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 111                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 112                 if (!IS_ERR(clnt->cl_dentry))
 113                         return 0;
 114                 error = PTR_ERR(clnt->cl_dentry);
 115                 if (error != -EEXIST) {
 116                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 117                                         clnt->cl_pathname, error);
 118                         rpc_put_mount();
 119                         return error;
 120                 }
 121         }
 122 }
 123
 124 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 125 {
 126         struct rpc_version      *version;
 127         struct rpc_clnt         *clnt = NULL;
 128         struct rpc_auth         *auth;
 129         int err;
 130         size_t len;
 131
 132         /* sanity check the name before trying to print it */
 133         err = -EINVAL;
 134         len = strlen(servname);
 135         if (len > RPC_MAXNETNAMELEN)
 136                 goto out_no_rpciod;
 137         len++;
 138
 139         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 140                         program->name, servname, xprt);
 141
 142         err = rpciod_up();
 143         if (err)
 144                 goto out_no_rpciod;
 145         err = -EINVAL;
 146         if (!xprt)
 147                 goto out_no_xprt;
 148         if (vers >= program->nrvers || !(version = program->version[vers]))
 149                 goto out_err;
 150
 151         err = -ENOMEM;
 152         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 153         if (!clnt)
 154                 goto out_err;
 155         clnt->cl_parent = clnt;
 156
 157         clnt->cl_server = clnt->cl_inline_name;
 158         if (len > sizeof(clnt->cl_inline_name)) {
 159                 char *buf = kmalloc(len, GFP_KERNEL);
 160                 if (buf != 0)
 161                         clnt->cl_server = buf;
 162                 else
 163                         len = sizeof(clnt->cl_inline_name);
 164         }
 165         strlcpy(clnt->cl_server, servname, len);
 166
 167         clnt->cl_xprt     = xprt;
 168         clnt->cl_procinfo = version->procs;
 169         clnt->cl_maxproc  = version->nrprocs;
 170         clnt->cl_protname = program->name;
 171         clnt->cl_prog     = program->number;
 172         clnt->cl_vers     = version->number;
 173         clnt->cl_stats    = program->stats;
 174         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 175         err = -ENOMEM;
 176         if (clnt->cl_metrics == NULL)
 177                 goto out_no_stats;
 178         clnt->cl_program  = program;
 179         INIT_LIST_HEAD(&clnt->cl_tasks);
 180         spin_lock_init(&clnt->cl_lock);
 181
 182         if (!xprt_bound(clnt->cl_xprt))
 183                 clnt->cl_autobind = 1;
 184
 185         clnt->cl_rtt = &clnt->cl_rtt_default;
 186         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 187
 188         kref_init(&clnt->cl_kref);
 189
 190         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 191         if (err < 0)
 192                 goto out_no_path;
 193
 194         auth = rpcauth_create(flavor, clnt);
 195         if (IS_ERR(auth)) {
 196                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 197                                 flavor);
 198                 err = PTR_ERR(auth);
 199                 goto out_no_auth;
 200         }
 201
 202         /* save the nodename */
 203         clnt->cl_nodelen = strlen(utsname()->nodename);
 204         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 205                 clnt->cl_nodelen = UNX_MAXNODENAME;
 206         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 207         rpc_register_client(clnt);
 208         return clnt;
 209
 210 out_no_auth:
 211         if (!IS_ERR(clnt->cl_dentry)) {
 212                 rpc_rmdir(clnt->cl_dentry);
 213                 rpc_put_mount();
 214         }
 215 out_no_path:
 216         rpc_free_iostats(clnt->cl_metrics);
 217 out_no_stats:
 218         if (clnt->cl_server != clnt->cl_inline_name)
 219                 kfree(clnt->cl_server);
 220         kfree(clnt);
 221 out_err:
 222         xprt_put(xprt);
 223 out_no_xprt:
 224         rpciod_down();
 225 out_no_rpciod:
 226         return ERR_PTR(err);
 227 }
 228
 229 /*
 230  * rpc_create - create an RPC client and transport with one call
 231  * @args: rpc_clnt create argument structure
 232  *
 233  * Creates and initializes an RPC transport and an RPC client.
 234  *
 235  * It can ping the server in order to determine if it is up, and to see if
 236  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 237  * this behavior so asynchronous tasks can also use rpc_create.
 238  */
 239 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 240 {
 241         struct rpc_xprt *xprt;
 242         struct rpc_clnt *clnt;
 243         struct xprt_create xprtargs = {
 244                 .ident = args->protocol,
 245                 .srcaddr = args->saddress,
 246                 .dstaddr = args->address,
 247                 .addrlen = args->addrsize,
 248                 .timeout = args->timeout
 249         };
 250         char servername[20];
 251
 252         xprt = xprt_create_transport(&xprtargs);
 253         if (IS_ERR(xprt))
 254                 return (struct rpc_clnt *)xprt;
 255
 256         /*
 257          * If the caller chooses not to specify a hostname, whip
 258          * up a string representation of the passed-in address.
 259          */
 260         if (args->servername == NULL) {
 261                 struct sockaddr_in *addr =
 262                                         (struct sockaddr_in *) args->address;
 263                 snprintf(servername, sizeof(servername), NIPQUAD_FMT,
 264                         NIPQUAD(addr->sin_addr.s_addr));
 265                 args->servername = servername;
 266         }
 267
 268         /*
 269          * By default, kernel RPC client connects from a reserved port.
 270          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 271          * but it is always enabled for rpciod, which handles the connect
 272          * operation.
 273          */
 274         xprt->resvport = 1;
 275         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 276                 xprt->resvport = 0;
 277
 278         clnt = rpc_new_client(xprt, args->servername, args->program,
 279                                 args->version, args->authflavor);
 280         if (IS_ERR(clnt))
 281                 return clnt;
 282
 283         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 284                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 285                 if (err != 0) {
 286                         rpc_shutdown_client(clnt);
 287                         return ERR_PTR(err);
 288                 }
 289         }
 290
 291         clnt->cl_softrtry = 1;
 292         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 293                 clnt->cl_softrtry = 0;
 294
 295         if (args->flags & RPC_CLNT_CREATE_INTR)
 296                 clnt->cl_intr = 1;
 297         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 298                 clnt->cl_autobind = 1;
 299         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 300                 clnt->cl_discrtry = 1;
 301
 302         return clnt;
 303 }
 304 EXPORT_SYMBOL_GPL(rpc_create);
 305
 306 /*
 307  * This function clones the RPC client structure. It allows us to share the
 308  * same transport while varying parameters such as the authentication
 309  * flavour.
 310  */
 311 struct rpc_clnt *
 312 rpc_clone_client(struct rpc_clnt *clnt)
 313 {
 314         struct rpc_clnt *new;
 315         int err = -ENOMEM;
 316
 317         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 318         if (!new)
 319                 goto out_no_clnt;
 320         new->cl_parent = clnt;
 321         /* Turn off autobind on clones */
 322         new->cl_autobind = 0;
 323         INIT_LIST_HEAD(&new->cl_tasks);
 324         spin_lock_init(&new->cl_lock);
 325         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 326         new->cl_metrics = rpc_alloc_iostats(clnt);
 327         if (new->cl_metrics == NULL)
 328                 goto out_no_stats;
 329         kref_init(&new->cl_kref);
 330         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 331         if (err != 0)
 332                 goto out_no_path;
 333         if (new->cl_auth)
 334                 atomic_inc(&new->cl_auth->au_count);
 335         xprt_get(clnt->cl_xprt);
 336         kref_get(&clnt->cl_kref);
 337         rpc_register_client(new);
 338         rpciod_up();
 339         return new;
 340 out_no_path:
 341         rpc_free_iostats(new->cl_metrics);
 342 out_no_stats:
 343         kfree(new);
 344 out_no_clnt:
 345         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 346         return ERR_PTR(err);
 347 }
 348 EXPORT_SYMBOL_GPL(rpc_clone_client);
 349
 350 /*
 351  * Properly shut down an RPC client, terminating all outstanding
 352  * requests.
 353  */
 354 void rpc_shutdown_client(struct rpc_clnt *clnt)
 355 {
 356         dprintk("RPC:       shutting down %s client for %s\n",
 357                         clnt->cl_protname, clnt->cl_server);
 358
 359         while (!list_empty(&clnt->cl_tasks)) {
 360                 rpc_killall_tasks(clnt);
 361                 wait_event_timeout(destroy_wait,
 362                         list_empty(&clnt->cl_tasks), 1*HZ);
 363         }
 364
 365         rpc_release_client(clnt);
 366 }
 367 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 368
 369 /*
 370  * Free an RPC client
 371  */
 372 static void
 373 rpc_free_client(struct kref *kref)
 374 {
 375         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 376
 377         dprintk("RPC:       destroying %s client for %s\n",
 378                         clnt->cl_protname, clnt->cl_server);
 379         if (!IS_ERR(clnt->cl_dentry)) {
 380                 rpc_rmdir(clnt->cl_dentry);
 381                 rpc_put_mount();
 382         }
 383         if (clnt->cl_parent != clnt) {
 384                 rpc_release_client(clnt->cl_parent);
 385                 goto out_free;
 386         }
 387         if (clnt->cl_server != clnt->cl_inline_name)
 388                 kfree(clnt->cl_server);
 389 out_free:
 390         rpc_unregister_client(clnt);
 391         rpc_free_iostats(clnt->cl_metrics);
 392         clnt->cl_metrics = NULL;
 393         xprt_put(clnt->cl_xprt);
 394         rpciod_down();
 395         kfree(clnt);
 396 }
 397
 398 /*
 399  * Free an RPC client
 400  */
 401 static void
 402 rpc_free_auth(struct kref *kref)
 403 {
 404         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 405
 406         if (clnt->cl_auth == NULL) {
 407                 rpc_free_client(kref);
 408                 return;
 409         }
 410
 411         /*
 412          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 413          *       release remaining GSS contexts. This mechanism ensures
 414          *       that it can do so safely.
 415          */
 416         kref_init(kref);
 417         rpcauth_release(clnt->cl_auth);
 418         clnt->cl_auth = NULL;
 419         kref_put(kref, rpc_free_client);
 420 }
 421
 422 /*
 423  * Release reference to the RPC client
 424  */
 425 void
 426 rpc_release_client(struct rpc_clnt *clnt)
 427 {
 428         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 429
 430         if (list_empty(&clnt->cl_tasks))
 431                 wake_up(&destroy_wait);
 432         kref_put(&clnt->cl_kref, rpc_free_auth);
 433 }
 434
 435 /**
 436  * rpc_bind_new_program - bind a new RPC program to an existing client
 437  * @old - old rpc_client
 438  * @program - rpc program to set
 439  * @vers - rpc program version
 440  *
 441  * Clones the rpc client and sets up a new RPC program. This is mainly
 442  * of use for enabling different RPC programs to share the same transport.
 443  * The Sun NFSv2/v3 ACL protocol can do this.
 444  */
 445 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 446                                       struct rpc_program *program,
 447                                       u32 vers)
 448 {
 449         struct rpc_clnt *clnt;
 450         struct rpc_version *version;
 451         int err;
 452
 453         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 454         version = program->version[vers];
 455         clnt = rpc_clone_client(old);
 456         if (IS_ERR(clnt))
 457                 goto out;
 458         clnt->cl_procinfo = version->procs;
 459         clnt->cl_maxproc  = version->nrprocs;
 460         clnt->cl_protname = program->name;
 461         clnt->cl_prog     = program->number;
 462         clnt->cl_vers     = version->number;
 463         clnt->cl_stats    = program->stats;
 464         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 465         if (err != 0) {
 466                 rpc_shutdown_client(clnt);
 467                 clnt = ERR_PTR(err);
 468         }
 469 out:
 470         return clnt;
 471 }
 472 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 473
 474 /*
 475  * Default callback for async RPC calls
 476  */
 477 static void
 478 rpc_default_callback(struct rpc_task *task, void *data)
 479 {
 480 }
 481
 482 static const struct rpc_call_ops rpc_default_ops = {
 483         .rpc_call_done = rpc_default_callback,
 484 };
 485
 486 /*
 487  *      Export the signal mask handling for synchronous code that
 488  *      sleeps on RPC calls
 489  */
 490 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 491
 492 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 493 {
 494         unsigned long   sigallow = sigmask(SIGKILL);
 495         sigset_t sigmask;
 496
 497         /* Block all signals except those listed in sigallow */
 498         if (intr)
 499                 sigallow |= RPC_INTR_SIGNALS;
 500         siginitsetinv(&sigmask, sigallow);
 501         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 502 }
 503
 504 static void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 505 {
 506         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 507 }
 508
 509 static void rpc_restore_sigmask(sigset_t *oldset)
 510 {
 511         sigprocmask(SIG_SETMASK, oldset, NULL);
 512 }
 513
 514 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 515 {
 516         rpc_save_sigmask(oldset, clnt->cl_intr);
 517 }
 518 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
 519
 520 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 521 {
 522         rpc_restore_sigmask(oldset);
 523 }
 524 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
 525
 526 /**
 527  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 528  * @task_setup_data: pointer to task initialisation data
 529  */
 530 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 531 {
 532         struct rpc_task *task, *ret;
 533         sigset_t oldset;
 534
 535         task = rpc_new_task(task_setup_data);
 536         if (task == NULL) {
 537                 rpc_release_calldata(task_setup_data->callback_ops,
 538                                 task_setup_data->callback_data);
 539                 ret = ERR_PTR(-ENOMEM);
 540                 goto out;
 541         }
 542
 543         if (task_setup_data->rpc_message != NULL) {
 544                 rpc_call_setup(task, task_setup_data->rpc_message, 0);
 545                 if (task->tk_status != 0) {
 546                         ret = ERR_PTR(task->tk_status);
 547                         rpc_put_task(task);
 548                         goto out;
 549                 }
 550         }
 551         atomic_inc(&task->tk_count);
 552         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 553         rpc_task_sigmask(task, &oldset);
 554         rpc_execute(task);
 555         rpc_restore_sigmask(&oldset);
 556         ret = task;
 557 out:
 558         return ret;
 559 }
 560 EXPORT_SYMBOL_GPL(rpc_run_task);
 561
 562 /**
 563  * rpc_call_sync - Perform a synchronous RPC call
 564  * @clnt: pointer to RPC client
 565  * @msg: RPC call parameters
 566  * @flags: RPC call flags
 567  */
 568 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 569 {
 570         struct rpc_task *task;
 571         struct rpc_task_setup task_setup_data = {
 572                 .rpc_client = clnt,
 573                 .rpc_message = msg,
 574                 .callback_ops = &rpc_default_ops,
 575                 .flags = flags,
 576         };
 577         int status;
 578
 579         BUG_ON(flags & RPC_TASK_ASYNC);
 580
 581         task = rpc_run_task(&task_setup_data);
 582         if (IS_ERR(task))
 583                 return PTR_ERR(task);
 584         status = task->tk_status;
 585         rpc_put_task(task);
 586         return status;
 587 }
 588 EXPORT_SYMBOL_GPL(rpc_call_sync);
 589
 590 /**
 591  * rpc_call_async - Perform an asynchronous RPC call
 592  * @clnt: pointer to RPC client
 593  * @msg: RPC call parameters
 594  * @flags: RPC call flags
 595  * @ops: RPC call ops
 596  * @data: user call data
 597  */
 598 int
 599 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 600                const struct rpc_call_ops *tk_ops, void *data)
 601 {
 602         struct rpc_task *task;
 603         struct rpc_task_setup task_setup_data = {
 604                 .rpc_client = clnt,
 605                 .rpc_message = msg,
 606                 .callback_ops = tk_ops,
 607                 .callback_data = data,
 608                 .flags = flags|RPC_TASK_ASYNC,
 609         };
 610
 611         task = rpc_run_task(&task_setup_data);
 612         if (IS_ERR(task))
 613                 return PTR_ERR(task);
 614         rpc_put_task(task);
 615         return 0;
 616 }
 617 EXPORT_SYMBOL_GPL(rpc_call_async);
 618
 619 void
 620 rpc_call_setup(struct rpc_task *task, const struct rpc_message *msg, int flags)
 621 {
 622         task->tk_msg   = *msg;
 623         task->tk_flags |= flags;
 624         /* Bind the user cred */
 625         if (task->tk_msg.rpc_cred != NULL)
 626                 rpcauth_holdcred(task);
 627         else
 628                 rpcauth_bindcred(task);
 629
 630         if (task->tk_status == 0)
 631                 task->tk_action = call_start;
 632         else
 633                 task->tk_action = rpc_exit_task;
 634 }
 635 EXPORT_SYMBOL_GPL(rpc_call_setup);
 636
 637 void
 638 rpc_call_start(struct rpc_task *task)
 639 {
 640         task->tk_action = call_start;
 641 }
 642 EXPORT_SYMBOL_GPL(rpc_call_start);
 643
 644 /**
 645  * rpc_peeraddr - extract remote peer address from clnt's xprt
 646  * @clnt: RPC client structure
 647  * @buf: target buffer
 648  * @size: length of target buffer
 649  *
 650  * Returns the number of bytes that are actually in the stored address.
 651  */
 652 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 653 {
 654         size_t bytes;
 655         struct rpc_xprt *xprt = clnt->cl_xprt;
 656
 657         bytes = sizeof(xprt->addr);
 658         if (bytes > bufsize)
 659                 bytes = bufsize;
 660         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 661         return xprt->addrlen;
 662 }
 663 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 664
 665 /**
 666  * rpc_peeraddr2str - return remote peer address in printable format
 667  * @clnt: RPC client structure
 668  * @format: address format
 669  *
 670  */
 671 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 672 {
 673         struct rpc_xprt *xprt = clnt->cl_xprt;
 674
 675         if (xprt->address_strings[format] != NULL)
 676                 return xprt->address_strings[format];
 677         else
 678                 return "unprintable";
 679 }
 680 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 681
 682 void
 683 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 684 {
 685         struct rpc_xprt *xprt = clnt->cl_xprt;
 686         if (xprt->ops->set_buffer_size)
 687                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 688 }
 689 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 690
 691 /*
 692  * Return size of largest payload RPC client can support, in bytes
 693  *
 694  * For stream transports, this is one RPC record fragment (see RFC
 695  * 1831), as we don't support multi-record requests yet.  For datagram
 696  * transports, this is the size of an IP packet minus the IP, UDP, and
 697  * RPC header sizes.
 698  */
 699 size_t rpc_max_payload(struct rpc_clnt *clnt)
 700 {
 701         return clnt->cl_xprt->max_payload;
 702 }
 703 EXPORT_SYMBOL_GPL(rpc_max_payload);
 704
 705 /**
 706  * rpc_force_rebind - force transport to check that remote port is unchanged
 707  * @clnt: client to rebind
 708  *
 709  */
 710 void rpc_force_rebind(struct rpc_clnt *clnt)
 711 {
 712         if (clnt->cl_autobind)
 713                 xprt_clear_bound(clnt->cl_xprt);
 714 }
 715 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 716
 717 /*
 718  * Restart an (async) RPC call. Usually called from within the
 719  * exit handler.
 720  */
 721 void
 722 rpc_restart_call(struct rpc_task *task)
 723 {
 724         if (RPC_ASSASSINATED(task))
 725                 return;
 726
 727         task->tk_action = call_start;
 728 }
 729 EXPORT_SYMBOL_GPL(rpc_restart_call);
 730
 731 /*
 732  * 0.  Initial state
 733  *
 734  *     Other FSM states can be visited zero or more times, but
 735  *     this state is visited exactly once for each RPC.
 736  */
 737 static void
 738 call_start(struct rpc_task *task)
 739 {
 740         struct rpc_clnt *clnt = task->tk_client;
 741
 742         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 743                         clnt->cl_protname, clnt->cl_vers,
 744                         task->tk_msg.rpc_proc->p_proc,
 745                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 746
 747         /* Increment call count */
 748         task->tk_msg.rpc_proc->p_count++;
 749         clnt->cl_stats->rpccnt++;
 750         task->tk_action = call_reserve;
 751 }
 752
 753 /*
 754  * 1.   Reserve an RPC call slot
 755  */
 756 static void
 757 call_reserve(struct rpc_task *task)
 758 {
 759         dprint_status(task);
 760
 761         if (!rpcauth_uptodatecred(task)) {
 762                 task->tk_action = call_refresh;
 763                 return;
 764         }
 765
 766         task->tk_status  = 0;
 767         task->tk_action  = call_reserveresult;
 768         xprt_reserve(task);
 769 }
 770
 771 /*
 772  * 1b.  Grok the result of xprt_reserve()
 773  */
 774 static void
 775 call_reserveresult(struct rpc_task *task)
 776 {
 777         int status = task->tk_status;
 778
 779         dprint_status(task);
 780
 781         /*
 782          * After a call to xprt_reserve(), we must have either
 783          * a request slot or else an error status.
 784          */
 785         task->tk_status = 0;
 786         if (status >= 0) {
 787                 if (task->tk_rqstp) {
 788                         task->tk_action = call_allocate;
 789                         return;
 790                 }
 791
 792                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 793                                 __FUNCTION__, status);
 794                 rpc_exit(task, -EIO);
 795                 return;
 796         }
 797
 798         /*
 799          * Even though there was an error, we may have acquired
 800          * a request slot somehow.  Make sure not to leak it.
 801          */
 802         if (task->tk_rqstp) {
 803                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 804                                 __FUNCTION__, status);
 805                 xprt_release(task);
 806         }
 807
 808         switch (status) {
 809         case -EAGAIN:   /* woken up; retry */
 810                 task->tk_action = call_reserve;
 811                 return;
 812         case -EIO:      /* probably a shutdown */
 813                 break;
 814         default:
 815                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 816                                 __FUNCTION__, status);
 817                 break;
 818         }
 819         rpc_exit(task, status);
 820 }
 821
 822 /*
 823  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 824  *      (Note: buffer memory is freed in xprt_release).
 825  */
 826 static void
 827 call_allocate(struct rpc_task *task)
 828 {
 829         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 830         struct rpc_rqst *req = task->tk_rqstp;
 831         struct rpc_xprt *xprt = task->tk_xprt;
 832         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 833
 834         dprint_status(task);
 835
 836         task->tk_status = 0;
 837         task->tk_action = call_bind;
 838
 839         if (req->rq_buffer)
 840                 return;
 841
 842         if (proc->p_proc != 0) {
 843                 BUG_ON(proc->p_arglen == 0);
 844                 if (proc->p_decode != NULL)
 845                         BUG_ON(proc->p_replen == 0);
 846         }
 847
 848         /*
 849          * Calculate the size (in quads) of the RPC call
 850          * and reply headers, and convert both values
 851          * to byte sizes.
 852          */
 853         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 854         req->rq_callsize <<= 2;
 855         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 856         req->rq_rcvsize <<= 2;
 857
 858         req->rq_buffer = xprt->ops->buf_alloc(task,
 859                                         req->rq_callsize + req->rq_rcvsize);
 860         if (req->rq_buffer != NULL)
 861                 return;
 862
 863         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 864
 865         if (RPC_IS_ASYNC(task) || !signalled()) {
 866                 task->tk_action = call_allocate;
 867                 rpc_delay(task, HZ>>4);
 868                 return;
 869         }
 870
 871         rpc_exit(task, -ERESTARTSYS);
 872 }
 873
 874 static inline int
 875 rpc_task_need_encode(struct rpc_task *task)
 876 {
 877         return task->tk_rqstp->rq_snd_buf.len == 0;
 878 }
 879
 880 static inline void
 881 rpc_task_force_reencode(struct rpc_task *task)
 882 {
 883         task->tk_rqstp->rq_snd_buf.len = 0;
 884 }
 885
 886 static inline void
 887 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 888 {
 889         buf->head[0].iov_base = start;
 890         buf->head[0].iov_len = len;
 891         buf->tail[0].iov_len = 0;
 892         buf->page_len = 0;
 893         buf->flags = 0;
 894         buf->len = 0;
 895         buf->buflen = len;
 896 }
 897
 898 /*
 899  * 3.   Encode arguments of an RPC call
 900  */
 901 static void
 902 call_encode(struct rpc_task *task)
 903 {
 904         struct rpc_rqst *req = task->tk_rqstp;
 905         kxdrproc_t      encode;
 906         __be32          *p;
 907
 908         dprint_status(task);
 909
 910         rpc_xdr_buf_init(&req->rq_snd_buf,
 911                          req->rq_buffer,
 912                          req->rq_callsize);
 913         rpc_xdr_buf_init(&req->rq_rcv_buf,
 914                          (char *)req->rq_buffer + req->rq_callsize,
 915                          req->rq_rcvsize);
 916
 917         /* Encode header and provided arguments */
 918         encode = task->tk_msg.rpc_proc->p_encode;
 919         if (!(p = call_header(task))) {
 920                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 921                 rpc_exit(task, -EIO);
 922                 return;
 923         }
 924         if (encode == NULL)
 925                 return;
 926
 927         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 928                         task->tk_msg.rpc_argp);
 929         if (task->tk_status == -ENOMEM) {
 930                 /* XXX: Is this sane? */
 931                 rpc_delay(task, 3*HZ);
 932                 task->tk_status = -EAGAIN;
 933         }
 934 }
 935
 936 /*
 937  * 4.   Get the server port number if not yet set
 938  */
 939 static void
 940 call_bind(struct rpc_task *task)
 941 {
 942         struct rpc_xprt *xprt = task->tk_xprt;
 943
 944         dprint_status(task);
 945
 946         task->tk_action = call_connect;
 947         if (!xprt_bound(xprt)) {
 948                 task->tk_action = call_bind_status;
 949                 task->tk_timeout = xprt->bind_timeout;
 950                 xprt->ops->rpcbind(task);
 951         }
 952 }
 953
 954 /*
 955  * 4a.  Sort out bind result
 956  */
 957 static void
 958 call_bind_status(struct rpc_task *task)
 959 {
 960         int status = -EIO;
 961
 962         if (task->tk_status >= 0) {
 963                 dprint_status(task);
 964                 task->tk_status = 0;
 965                 task->tk_action = call_connect;
 966                 return;
 967         }
 968
 969         switch (task->tk_status) {
 970         case -EAGAIN:
 971                 dprintk("RPC: %5u rpcbind waiting for another request "
 972                                 "to finish\n", task->tk_pid);
 973                 /* avoid busy-waiting here -- could be a network outage. */
 974                 rpc_delay(task, 5*HZ);
 975                 goto retry_timeout;
 976         case -EACCES:
 977                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 978                                 "unavailable\n", task->tk_pid);
 979                 /* fail immediately if this is an RPC ping */
 980                 if (task->tk_msg.rpc_proc->p_proc == 0) {
 981                         status = -EOPNOTSUPP;
 982                         break;
 983                 }
 984                 rpc_delay(task, 3*HZ);
 985                 goto retry_timeout;
 986         case -ETIMEDOUT:
 987                 dprintk("RPC: %5u rpcbind request timed out\n",
 988                                 task->tk_pid);
 989                 goto retry_timeout;
 990         case -EPFNOSUPPORT:
 991                 /* server doesn't support any rpcbind version we know of */
 992                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 993                                 task->tk_pid);
 994                 break;
 995         case -EPROTONOSUPPORT:
 996                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 997                                 task->tk_pid);
 998                 task->tk_status = 0;
 999                 task->tk_action = call_bind;
1000                 return;
1001         default:
1002                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1003                                 task->tk_pid, -task->tk_status);
1004         }
1005
1006         rpc_exit(task, status);
1007         return;
1008
1009 retry_timeout:
1010         task->tk_action = call_timeout;
1011 }
1012
1013 /*
1014  * 4b.  Connect to the RPC server
1015  */
1016 static void
1017 call_connect(struct rpc_task *task)
1018 {
1019         struct rpc_xprt *xprt = task->tk_xprt;
1020
1021         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1022                         task->tk_pid, xprt,
1023                         (xprt_connected(xprt) ? "is" : "is not"));
1024
1025         task->tk_action = call_transmit;
1026         if (!xprt_connected(xprt)) {
1027                 task->tk_action = call_connect_status;
1028                 if (task->tk_status < 0)
1029                         return;
1030                 xprt_connect(task);
1031         }
1032 }
1033
1034 /*
1035  * 4c.  Sort out connect result
1036  */
1037 static void
1038 call_connect_status(struct rpc_task *task)
1039 {
1040         struct rpc_clnt *clnt = task->tk_client;
1041         int status = task->tk_status;
1042
1043         dprint_status(task);
1044
1045         task->tk_status = 0;
1046         if (status >= 0) {
1047                 clnt->cl_stats->netreconn++;
1048                 task->tk_action = call_transmit;
1049                 return;
1050         }
1051
1052         /* Something failed: remote service port may have changed */
1053         rpc_force_rebind(clnt);
1054
1055         switch (status) {
1056         case -ENOTCONN:
1057         case -EAGAIN:
1058                 task->tk_action = call_bind;
1059                 if (!RPC_IS_SOFT(task))
1060                         return;
1061                 /* if soft mounted, test if we've timed out */
1062         case -ETIMEDOUT:
1063                 task->tk_action = call_timeout;
1064                 return;
1065         }
1066         rpc_exit(task, -EIO);
1067 }
1068
1069 /*
1070  * 5.   Transmit the RPC request, and wait for reply
1071  */
1072 static void
1073 call_transmit(struct rpc_task *task)
1074 {
1075         dprint_status(task);
1076
1077         task->tk_action = call_status;
1078         if (task->tk_status < 0)
1079                 return;
1080         task->tk_status = xprt_prepare_transmit(task);
1081         if (task->tk_status != 0)
1082                 return;
1083         task->tk_action = call_transmit_status;
1084         /* Encode here so that rpcsec_gss can use correct sequence number. */
1085         if (rpc_task_need_encode(task)) {
1086                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1087                 call_encode(task);
1088                 /* Did the encode result in an error condition? */
1089                 if (task->tk_status != 0)
1090                         return;
1091         }
1092         xprt_transmit(task);
1093         if (task->tk_status < 0)
1094                 return;
1095         /*
1096          * On success, ensure that we call xprt_end_transmit() before sleeping
1097          * in order to allow access to the socket to other RPC requests.
1098          */
1099         call_transmit_status(task);
1100         if (task->tk_msg.rpc_proc->p_decode != NULL)
1101                 return;
1102         task->tk_action = rpc_exit_task;
1103         rpc_wake_up_task(task);
1104 }
1105
1106 /*
1107  * 5a.  Handle cleanup after a transmission
1108  */
1109 static void
1110 call_transmit_status(struct rpc_task *task)
1111 {
1112         task->tk_action = call_status;
1113         /*
1114          * Special case: if we've been waiting on the socket's write_space()
1115          * callback, then don't call xprt_end_transmit().
1116          */
1117         if (task->tk_status == -EAGAIN)
1118                 return;
1119         xprt_end_transmit(task);
1120         rpc_task_force_reencode(task);
1121 }
1122
1123 /*
1124  * 6.   Sort out the RPC call status
1125  */
1126 static void
1127 call_status(struct rpc_task *task)
1128 {
1129         struct rpc_clnt *clnt = task->tk_client;
1130         struct rpc_rqst *req = task->tk_rqstp;
1131         int             status;
1132
1133         if (req->rq_received > 0 && !req->rq_bytes_sent)
1134                 task->tk_status = req->rq_received;
1135
1136         dprint_status(task);
1137
1138         status = task->tk_status;
1139         if (status >= 0) {
1140                 task->tk_action = call_decode;
1141                 return;
1142         }
1143
1144         task->tk_status = 0;
1145         switch(status) {
1146         case -EHOSTDOWN:
1147         case -EHOSTUNREACH:
1148         case -ENETUNREACH:
1149                 /*
1150                  * Delay any retries for 3 seconds, then handle as if it
1151                  * were a timeout.
1152                  */
1153                 rpc_delay(task, 3*HZ);
1154         case -ETIMEDOUT:
1155                 task->tk_action = call_timeout;
1156                 if (task->tk_client->cl_discrtry)
1157                         xprt_force_disconnect(task->tk_xprt);
1158                 break;
1159         case -ECONNREFUSED:
1160         case -ENOTCONN:
1161                 rpc_force_rebind(clnt);
1162                 task->tk_action = call_bind;
1163                 break;
1164         case -EAGAIN:
1165                 task->tk_action = call_transmit;
1166                 break;
1167         case -EIO:
1168                 /* shutdown or soft timeout */
1169                 rpc_exit(task, status);
1170                 break;
1171         default:
1172                 printk("%s: RPC call returned error %d\n",
1173                                clnt->cl_protname, -status);
1174                 rpc_exit(task, status);
1175         }
1176 }
1177
1178 /*
1179  * 6a.  Handle RPC timeout
1180  *      We do not release the request slot, so we keep using the
1181  *      same XID for all retransmits.
1182  */
1183 static void
1184 call_timeout(struct rpc_task *task)
1185 {
1186         struct rpc_clnt *clnt = task->tk_client;
1187
1188         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1189                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1190                 goto retry;
1191         }
1192
1193         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1194         task->tk_timeouts++;
1195
1196         if (RPC_IS_SOFT(task)) {
1197                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1198                                 clnt->cl_protname, clnt->cl_server);
1199                 rpc_exit(task, -EIO);
1200                 return;
1201         }
1202
1203         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1204                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1205                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1206                         clnt->cl_protname, clnt->cl_server);
1207         }
1208         rpc_force_rebind(clnt);
1209
1210 retry:
1211         clnt->cl_stats->rpcretrans++;
1212         task->tk_action = call_bind;
1213         task->tk_status = 0;
1214 }
1215
1216 /*
1217  * 7.   Decode the RPC reply
1218  */
1219 static void
1220 call_decode(struct rpc_task *task)
1221 {
1222         struct rpc_clnt *clnt = task->tk_client;
1223         struct rpc_rqst *req = task->tk_rqstp;
1224         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1225         __be32          *p;
1226
1227         dprintk("RPC: %5u call_decode (status %d)\n",
1228                         task->tk_pid, task->tk_status);
1229
1230         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1231                 printk(KERN_NOTICE "%s: server %s OK\n",
1232                         clnt->cl_protname, clnt->cl_server);
1233                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1234         }
1235
1236         if (task->tk_status < 12) {
1237                 if (!RPC_IS_SOFT(task)) {
1238                         task->tk_action = call_bind;
1239                         clnt->cl_stats->rpcretrans++;
1240                         goto out_retry;
1241                 }
1242                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1243                                 clnt->cl_protname, task->tk_status);
1244                 task->tk_action = call_timeout;
1245                 goto out_retry;
1246         }
1247
1248         /*
1249          * Ensure that we see all writes made by xprt_complete_rqst()
1250          * before it changed req->rq_received.
1251          */
1252         smp_rmb();
1253         req->rq_rcv_buf.len = req->rq_private_buf.len;
1254
1255         /* Check that the softirq receive buffer is valid */
1256         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1257                                 sizeof(req->rq_rcv_buf)) != 0);
1258
1259         /* Verify the RPC header */
1260         p = call_verify(task);
1261         if (IS_ERR(p)) {
1262                 if (p == ERR_PTR(-EAGAIN))
1263                         goto out_retry;
1264                 return;
1265         }
1266
1267         task->tk_action = rpc_exit_task;
1268
1269         if (decode) {
1270                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1271                                                       task->tk_msg.rpc_resp);
1272         }
1273         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1274                         task->tk_status);
1275         return;
1276 out_retry:
1277         req->rq_received = req->rq_private_buf.len = 0;
1278         task->tk_status = 0;
1279         if (task->tk_client->cl_discrtry)
1280                 xprt_force_disconnect(task->tk_xprt);
1281 }
1282
1283 /*
1284  * 8.   Refresh the credentials if rejected by the server
1285  */
1286 static void
1287 call_refresh(struct rpc_task *task)
1288 {
1289         dprint_status(task);
1290
1291         task->tk_action = call_refreshresult;
1292         task->tk_status = 0;
1293         task->tk_client->cl_stats->rpcauthrefresh++;
1294         rpcauth_refreshcred(task);
1295 }
1296
1297 /*
1298  * 8a.  Process the results of a credential refresh
1299  */
1300 static void
1301 call_refreshresult(struct rpc_task *task)
1302 {
1303         int status = task->tk_status;
1304
1305         dprint_status(task);
1306
1307         task->tk_status = 0;
1308         task->tk_action = call_reserve;
1309         if (status >= 0 && rpcauth_uptodatecred(task))
1310                 return;
1311         if (status == -EACCES) {
1312                 rpc_exit(task, -EACCES);
1313                 return;
1314         }
1315         task->tk_action = call_refresh;
1316         if (status != -ETIMEDOUT)
1317                 rpc_delay(task, 3*HZ);
1318         return;
1319 }
1320
1321 /*
1322  * Call header serialization
1323  */
1324 static __be32 *
1325 call_header(struct rpc_task *task)
1326 {
1327         struct rpc_clnt *clnt = task->tk_client;
1328         struct rpc_rqst *req = task->tk_rqstp;
1329         __be32          *p = req->rq_svec[0].iov_base;
1330
1331         /* FIXME: check buffer size? */
1332
1333         p = xprt_skip_transport_header(task->tk_xprt, p);
1334         *p++ = req->rq_xid;             /* XID */
1335         *p++ = htonl(RPC_CALL);         /* CALL */
1336         *p++ = htonl(RPC_VERSION);      /* RPC version */
1337         *p++ = htonl(clnt->cl_prog);    /* program number */
1338         *p++ = htonl(clnt->cl_vers);    /* program version */
1339         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1340         p = rpcauth_marshcred(task, p);
1341         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1342         return p;
1343 }
1344
1345 /*
1346  * Reply header verification
1347  */
1348 static __be32 *
1349 call_verify(struct rpc_task *task)
1350 {
1351         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1352         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1353         __be32  *p = iov->iov_base;
1354         u32 n;
1355         int error = -EACCES;
1356
1357         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1358                 /* RFC-1014 says that the representation of XDR data must be a
1359                  * multiple of four bytes
1360                  * - if it isn't pointer subtraction in the NFS client may give
1361                  *   undefined results
1362                  */
1363                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1364                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1365                        task->tk_rqstp->rq_rcv_buf.len);
1366                 goto out_eio;
1367         }
1368         if ((len -= 3) < 0)
1369                 goto out_overflow;
1370         p += 1; /* skip XID */
1371
1372         if ((n = ntohl(*p++)) != RPC_REPLY) {
1373                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1374                                 task->tk_pid, __FUNCTION__, n);
1375                 goto out_garbage;
1376         }
1377         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1378                 if (--len < 0)
1379                         goto out_overflow;
1380                 switch ((n = ntohl(*p++))) {
1381                         case RPC_AUTH_ERROR:
1382                                 break;
1383                         case RPC_MISMATCH:
1384                                 dprintk("RPC: %5u %s: RPC call version "
1385                                                 "mismatch!\n",
1386                                                 task->tk_pid, __FUNCTION__);
1387                                 error = -EPROTONOSUPPORT;
1388                                 goto out_err;
1389                         default:
1390                                 dprintk("RPC: %5u %s: RPC call rejected, "
1391                                                 "unknown error: %x\n",
1392                                                 task->tk_pid, __FUNCTION__, n);
1393                                 goto out_eio;
1394                 }
1395                 if (--len < 0)
1396                         goto out_overflow;
1397                 switch ((n = ntohl(*p++))) {
1398                 case RPC_AUTH_REJECTEDCRED:
1399                 case RPC_AUTH_REJECTEDVERF:
1400                 case RPCSEC_GSS_CREDPROBLEM:
1401                 case RPCSEC_GSS_CTXPROBLEM:
1402                         if (!task->tk_cred_retry)
1403                                 break;
1404                         task->tk_cred_retry--;
1405                         dprintk("RPC: %5u %s: retry stale creds\n",
1406                                         task->tk_pid, __FUNCTION__);
1407                         rpcauth_invalcred(task);
1408                         /* Ensure we obtain a new XID! */
1409                         xprt_release(task);
1410                         task->tk_action = call_refresh;
1411                         goto out_retry;
1412                 case RPC_AUTH_BADCRED:
1413                 case RPC_AUTH_BADVERF:
1414                         /* possibly garbled cred/verf? */
1415                         if (!task->tk_garb_retry)
1416                                 break;
1417                         task->tk_garb_retry--;
1418                         dprintk("RPC: %5u %s: retry garbled creds\n",
1419                                         task->tk_pid, __FUNCTION__);
1420                         task->tk_action = call_bind;
1421                         goto out_retry;
1422                 case RPC_AUTH_TOOWEAK:
1423                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1424                                "authentication.\n", task->tk_client->cl_server);
1425                         break;
1426                 default:
1427                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1428                                         task->tk_pid, __FUNCTION__, n);
1429                         error = -EIO;
1430                 }
1431                 dprintk("RPC: %5u %s: call rejected %d\n",
1432                                 task->tk_pid, __FUNCTION__, n);
1433                 goto out_err;
1434         }
1435         if (!(p = rpcauth_checkverf(task, p))) {
1436                 dprintk("RPC: %5u %s: auth check failed\n",
1437                                 task->tk_pid, __FUNCTION__);
1438                 goto out_garbage;               /* bad verifier, retry */
1439         }
1440         len = p - (__be32 *)iov->iov_base - 1;
1441         if (len < 0)
1442                 goto out_overflow;
1443         switch ((n = ntohl(*p++))) {
1444         case RPC_SUCCESS:
1445                 return p;
1446         case RPC_PROG_UNAVAIL:
1447                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1448                                 task->tk_pid, __FUNCTION__,
1449                                 (unsigned int)task->tk_client->cl_prog,
1450                                 task->tk_client->cl_server);
1451                 error = -EPFNOSUPPORT;
1452                 goto out_err;
1453         case RPC_PROG_MISMATCH:
1454                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1455                                 "server %s\n", task->tk_pid, __FUNCTION__,
1456                                 (unsigned int)task->tk_client->cl_prog,
1457                                 (unsigned int)task->tk_client->cl_vers,
1458                                 task->tk_client->cl_server);
1459                 error = -EPROTONOSUPPORT;
1460                 goto out_err;
1461         case RPC_PROC_UNAVAIL:
1462                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1463                                 "version %u on server %s\n",
1464                                 task->tk_pid, __FUNCTION__,
1465                                 task->tk_msg.rpc_proc,
1466                                 task->tk_client->cl_prog,
1467                                 task->tk_client->cl_vers,
1468                                 task->tk_client->cl_server);
1469                 error = -EOPNOTSUPP;
1470                 goto out_err;
1471         case RPC_GARBAGE_ARGS:
1472                 dprintk("RPC: %5u %s: server saw garbage\n",
1473                                 task->tk_pid, __FUNCTION__);
1474                 break;                  /* retry */
1475         default:
1476                 dprintk("RPC: %5u %s: server accept status: %x\n",
1477                                 task->tk_pid, __FUNCTION__, n);
1478                 /* Also retry */
1479         }
1480
1481 out_garbage:
1482         task->tk_client->cl_stats->rpcgarbage++;
1483         if (task->tk_garb_retry) {
1484                 task->tk_garb_retry--;
1485                 dprintk("RPC: %5u %s: retrying\n",
1486                                 task->tk_pid, __FUNCTION__);
1487                 task->tk_action = call_bind;
1488 out_retry:
1489                 return ERR_PTR(-EAGAIN);
1490         }
1491 out_eio:
1492         error = -EIO;
1493 out_err:
1494         rpc_exit(task, error);
1495         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1496                         __FUNCTION__, error);
1497         return ERR_PTR(error);
1498 out_overflow:
1499         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1500                         __FUNCTION__);
1501         goto out_garbage;
1502 }
1503
1504 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1505 {
1506         return 0;
1507 }
1508
1509 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1510 {
1511         return 0;
1512 }
1513
1514 static struct rpc_procinfo rpcproc_null = {
1515         .p_encode = rpcproc_encode_null,
1516         .p_decode = rpcproc_decode_null,
1517 };
1518
1519 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1520 {
1521         struct rpc_message msg = {
1522                 .rpc_proc = &rpcproc_null,
1523         };
1524         int err;
1525         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1526         err = rpc_call_sync(clnt, &msg, flags);
1527         put_rpccred(msg.rpc_cred);
1528         return err;
1529 }
1530
1531 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1532 {
1533         struct rpc_message msg = {
1534                 .rpc_proc = &rpcproc_null,
1535                 .rpc_cred = cred,
1536         };
1537         struct rpc_task_setup task_setup_data = {
1538                 .rpc_client = clnt,
1539                 .rpc_message = &msg,
1540                 .callback_ops = &rpc_default_ops,
1541                 .flags = flags,
1542         };
1543         return rpc_run_task(&task_setup_data);
1544 }
1545 EXPORT_SYMBOL_GPL(rpc_call_null);
1546
1547 #ifdef RPC_DEBUG
1548 void rpc_show_tasks(void)
1549 {
1550         struct rpc_clnt *clnt;
1551         struct rpc_task *t;
1552
1553         spin_lock(&rpc_client_lock);
1554         if (list_empty(&all_clients))
1555                 goto out;
1556         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1557                 "-rpcwait -action- ---ops--\n");
1558         list_for_each_entry(clnt, &all_clients, cl_clients) {
1559                 if (list_empty(&clnt->cl_tasks))
1560                         continue;
1561                 spin_lock(&clnt->cl_lock);
1562                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1563                         const char *rpc_waitq = "none";
1564                         int proc;
1565
1566                         if (t->tk_msg.rpc_proc)
1567                                 proc = t->tk_msg.rpc_proc->p_proc;
1568                         else
1569                                 proc = -1;
1570
1571                         if (RPC_IS_QUEUED(t))
1572                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1573
1574                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1575                                 t->tk_pid, proc,
1576                                 t->tk_flags, t->tk_status,
1577                                 t->tk_client,
1578                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1579                                 t->tk_rqstp, t->tk_timeout,
1580                                 rpc_waitq,
1581                                 t->tk_action, t->tk_ops);
1582                 }
1583                 spin_unlock(&clnt->cl_lock);
1584         }
1585 out:
1586         spin_unlock(&rpc_client_lock);
1587 }
1588 #endif