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