net/sunrpc/clnt.c

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