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 rpc_xprtsock_create xprtargs = {
 244                 .proto = 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                 xprt_release(task);
 850                 task->tk_action = call_reserve;
 851                 rpc_delay(task, HZ>>4);
 852                 return;
 853         }
 854
 855         rpc_exit(task, -ERESTARTSYS);
 856 }
 857
 858 static inline int
 859 rpc_task_need_encode(struct rpc_task *task)
 860 {
 861         return task->tk_rqstp->rq_snd_buf.len == 0;
 862 }
 863
 864 static inline void
 865 rpc_task_force_reencode(struct rpc_task *task)
 866 {
 867         task->tk_rqstp->rq_snd_buf.len = 0;
 868 }
 869
 870 static inline void
 871 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 872 {
 873         buf->head[0].iov_base = start;
 874         buf->head[0].iov_len = len;
 875         buf->tail[0].iov_len = 0;
 876         buf->page_len = 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                 rpc_delay(task, 3*HZ);
 963                 goto retry_timeout;
 964         case -ETIMEDOUT:
 965                 dprintk("RPC: %5u rpcbind request timed out\n",
 966                                 task->tk_pid);
 967                 goto retry_timeout;
 968         case -EPFNOSUPPORT:
 969                 /* server doesn't support any rpcbind version we know of */
 970                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 971                                 task->tk_pid);
 972                 break;
 973         case -EPROTONOSUPPORT:
 974                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 975                                 task->tk_pid);
 976                 task->tk_status = 0;
 977                 task->tk_action = call_bind;
 978                 return;
 979         default:
 980                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 981                                 task->tk_pid, -task->tk_status);
 982         }
 983
 984         rpc_exit(task, status);
 985         return;
 986
 987 retry_timeout:
 988         task->tk_action = call_timeout;
 989 }
 990
 991 /*
 992  * 4b.  Connect to the RPC server
 993  */
 994 static void
 995 call_connect(struct rpc_task *task)
 996 {
 997         struct rpc_xprt *xprt = task->tk_xprt;
 998
 999         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1000                         task->tk_pid, xprt,
1001                         (xprt_connected(xprt) ? "is" : "is not"));
1002
1003         task->tk_action = call_transmit;
1004         if (!xprt_connected(xprt)) {
1005                 task->tk_action = call_connect_status;
1006                 if (task->tk_status < 0)
1007                         return;
1008                 xprt_connect(task);
1009         }
1010 }
1011
1012 /*
1013  * 4c.  Sort out connect result
1014  */
1015 static void
1016 call_connect_status(struct rpc_task *task)
1017 {
1018         struct rpc_clnt *clnt = task->tk_client;
1019         int status = task->tk_status;
1020
1021         dprint_status(task);
1022
1023         task->tk_status = 0;
1024         if (status >= 0) {
1025                 clnt->cl_stats->netreconn++;
1026                 task->tk_action = call_transmit;
1027                 return;
1028         }
1029
1030         /* Something failed: remote service port may have changed */
1031         rpc_force_rebind(clnt);
1032
1033         switch (status) {
1034         case -ENOTCONN:
1035         case -EAGAIN:
1036                 task->tk_action = call_bind;
1037                 if (!RPC_IS_SOFT(task))
1038                         return;
1039                 /* if soft mounted, test if we've timed out */
1040         case -ETIMEDOUT:
1041                 task->tk_action = call_timeout;
1042                 return;
1043         }
1044         rpc_exit(task, -EIO);
1045 }
1046
1047 /*
1048  * 5.   Transmit the RPC request, and wait for reply
1049  */
1050 static void
1051 call_transmit(struct rpc_task *task)
1052 {
1053         dprint_status(task);
1054
1055         task->tk_action = call_status;
1056         if (task->tk_status < 0)
1057                 return;
1058         task->tk_status = xprt_prepare_transmit(task);
1059         if (task->tk_status != 0)
1060                 return;
1061         task->tk_action = call_transmit_status;
1062         /* Encode here so that rpcsec_gss can use correct sequence number. */
1063         if (rpc_task_need_encode(task)) {
1064                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1065                 call_encode(task);
1066                 /* Did the encode result in an error condition? */
1067                 if (task->tk_status != 0)
1068                         return;
1069         }
1070         xprt_transmit(task);
1071         if (task->tk_status < 0)
1072                 return;
1073         /*
1074          * On success, ensure that we call xprt_end_transmit() before sleeping
1075          * in order to allow access to the socket to other RPC requests.
1076          */
1077         call_transmit_status(task);
1078         if (task->tk_msg.rpc_proc->p_decode != NULL)
1079                 return;
1080         task->tk_action = rpc_exit_task;
1081         rpc_wake_up_task(task);
1082 }
1083
1084 /*
1085  * 5a.  Handle cleanup after a transmission
1086  */
1087 static void
1088 call_transmit_status(struct rpc_task *task)
1089 {
1090         task->tk_action = call_status;
1091         /*
1092          * Special case: if we've been waiting on the socket's write_space()
1093          * callback, then don't call xprt_end_transmit().
1094          */
1095         if (task->tk_status == -EAGAIN)
1096                 return;
1097         xprt_end_transmit(task);
1098         rpc_task_force_reencode(task);
1099 }
1100
1101 /*
1102  * 6.   Sort out the RPC call status
1103  */
1104 static void
1105 call_status(struct rpc_task *task)
1106 {
1107         struct rpc_clnt *clnt = task->tk_client;
1108         struct rpc_rqst *req = task->tk_rqstp;
1109         int             status;
1110
1111         if (req->rq_received > 0 && !req->rq_bytes_sent)
1112                 task->tk_status = req->rq_received;
1113
1114         dprint_status(task);
1115
1116         status = task->tk_status;
1117         if (status >= 0) {
1118                 task->tk_action = call_decode;
1119                 return;
1120         }
1121
1122         task->tk_status = 0;
1123         switch(status) {
1124         case -EHOSTDOWN:
1125         case -EHOSTUNREACH:
1126         case -ENETUNREACH:
1127                 /*
1128                  * Delay any retries for 3 seconds, then handle as if it
1129                  * were a timeout.
1130                  */
1131                 rpc_delay(task, 3*HZ);
1132         case -ETIMEDOUT:
1133                 task->tk_action = call_timeout;
1134                 if (task->tk_client->cl_discrtry)
1135                         xprt_disconnect(task->tk_xprt);
1136                 break;
1137         case -ECONNREFUSED:
1138         case -ENOTCONN:
1139                 rpc_force_rebind(clnt);
1140                 task->tk_action = call_bind;
1141                 break;
1142         case -EAGAIN:
1143                 task->tk_action = call_transmit;
1144                 break;
1145         case -EIO:
1146                 /* shutdown or soft timeout */
1147                 rpc_exit(task, status);
1148                 break;
1149         default:
1150                 printk("%s: RPC call returned error %d\n",
1151                                clnt->cl_protname, -status);
1152                 rpc_exit(task, status);
1153         }
1154 }
1155
1156 /*
1157  * 6a.  Handle RPC timeout
1158  *      We do not release the request slot, so we keep using the
1159  *      same XID for all retransmits.
1160  */
1161 static void
1162 call_timeout(struct rpc_task *task)
1163 {
1164         struct rpc_clnt *clnt = task->tk_client;
1165
1166         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1167                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1168                 goto retry;
1169         }
1170
1171         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1172         task->tk_timeouts++;
1173
1174         if (RPC_IS_SOFT(task)) {
1175                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1176                                 clnt->cl_protname, clnt->cl_server);
1177                 rpc_exit(task, -EIO);
1178                 return;
1179         }
1180
1181         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1182                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1183                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1184                         clnt->cl_protname, clnt->cl_server);
1185         }
1186         rpc_force_rebind(clnt);
1187
1188 retry:
1189         clnt->cl_stats->rpcretrans++;
1190         task->tk_action = call_bind;
1191         task->tk_status = 0;
1192 }
1193
1194 /*
1195  * 7.   Decode the RPC reply
1196  */
1197 static void
1198 call_decode(struct rpc_task *task)
1199 {
1200         struct rpc_clnt *clnt = task->tk_client;
1201         struct rpc_rqst *req = task->tk_rqstp;
1202         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1203         __be32          *p;
1204
1205         dprintk("RPC: %5u call_decode (status %d)\n",
1206                         task->tk_pid, task->tk_status);
1207
1208         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1209                 printk(KERN_NOTICE "%s: server %s OK\n",
1210                         clnt->cl_protname, clnt->cl_server);
1211                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1212         }
1213
1214         if (task->tk_status < 12) {
1215                 if (!RPC_IS_SOFT(task)) {
1216                         task->tk_action = call_bind;
1217                         clnt->cl_stats->rpcretrans++;
1218                         goto out_retry;
1219                 }
1220                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1221                                 clnt->cl_protname, task->tk_status);
1222                 task->tk_action = call_timeout;
1223                 goto out_retry;
1224         }
1225
1226         /*
1227          * Ensure that we see all writes made by xprt_complete_rqst()
1228          * before it changed req->rq_received.
1229          */
1230         smp_rmb();
1231         req->rq_rcv_buf.len = req->rq_private_buf.len;
1232
1233         /* Check that the softirq receive buffer is valid */
1234         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1235                                 sizeof(req->rq_rcv_buf)) != 0);
1236
1237         /* Verify the RPC header */
1238         p = call_verify(task);
1239         if (IS_ERR(p)) {
1240                 if (p == ERR_PTR(-EAGAIN))
1241                         goto out_retry;
1242                 return;
1243         }
1244
1245         task->tk_action = rpc_exit_task;
1246
1247         if (decode) {
1248                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1249                                                       task->tk_msg.rpc_resp);
1250         }
1251         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1252                         task->tk_status);
1253         return;
1254 out_retry:
1255         req->rq_received = req->rq_private_buf.len = 0;
1256         task->tk_status = 0;
1257         if (task->tk_client->cl_discrtry)
1258                 xprt_disconnect(task->tk_xprt);
1259 }
1260
1261 /*
1262  * 8.   Refresh the credentials if rejected by the server
1263  */
1264 static void
1265 call_refresh(struct rpc_task *task)
1266 {
1267         dprint_status(task);
1268
1269         xprt_release(task);     /* Must do to obtain new XID */
1270         task->tk_action = call_refreshresult;
1271         task->tk_status = 0;
1272         task->tk_client->cl_stats->rpcauthrefresh++;
1273         rpcauth_refreshcred(task);
1274 }
1275
1276 /*
1277  * 8a.  Process the results of a credential refresh
1278  */
1279 static void
1280 call_refreshresult(struct rpc_task *task)
1281 {
1282         int status = task->tk_status;
1283
1284         dprint_status(task);
1285
1286         task->tk_status = 0;
1287         task->tk_action = call_reserve;
1288         if (status >= 0 && rpcauth_uptodatecred(task))
1289                 return;
1290         if (status == -EACCES) {
1291                 rpc_exit(task, -EACCES);
1292                 return;
1293         }
1294         task->tk_action = call_refresh;
1295         if (status != -ETIMEDOUT)
1296                 rpc_delay(task, 3*HZ);
1297         return;
1298 }
1299
1300 /*
1301  * Call header serialization
1302  */
1303 static __be32 *
1304 call_header(struct rpc_task *task)
1305 {
1306         struct rpc_clnt *clnt = task->tk_client;
1307         struct rpc_rqst *req = task->tk_rqstp;
1308         __be32          *p = req->rq_svec[0].iov_base;
1309
1310         /* FIXME: check buffer size? */
1311
1312         p = xprt_skip_transport_header(task->tk_xprt, p);
1313         *p++ = req->rq_xid;             /* XID */
1314         *p++ = htonl(RPC_CALL);         /* CALL */
1315         *p++ = htonl(RPC_VERSION);      /* RPC version */
1316         *p++ = htonl(clnt->cl_prog);    /* program number */
1317         *p++ = htonl(clnt->cl_vers);    /* program version */
1318         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1319         p = rpcauth_marshcred(task, p);
1320         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1321         return p;
1322 }
1323
1324 /*
1325  * Reply header verification
1326  */
1327 static __be32 *
1328 call_verify(struct rpc_task *task)
1329 {
1330         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1331         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1332         __be32  *p = iov->iov_base;
1333         u32 n;
1334         int error = -EACCES;
1335
1336         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1337                 /* RFC-1014 says that the representation of XDR data must be a
1338                  * multiple of four bytes
1339                  * - if it isn't pointer subtraction in the NFS client may give
1340                  *   undefined results
1341                  */
1342                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1343                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1344                        task->tk_rqstp->rq_rcv_buf.len);
1345                 goto out_eio;
1346         }
1347         if ((len -= 3) < 0)
1348                 goto out_overflow;
1349         p += 1; /* skip XID */
1350
1351         if ((n = ntohl(*p++)) != RPC_REPLY) {
1352                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1353                                 task->tk_pid, __FUNCTION__, n);
1354                 goto out_garbage;
1355         }
1356         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1357                 if (--len < 0)
1358                         goto out_overflow;
1359                 switch ((n = ntohl(*p++))) {
1360                         case RPC_AUTH_ERROR:
1361                                 break;
1362                         case RPC_MISMATCH:
1363                                 dprintk("RPC: %5u %s: RPC call version "
1364                                                 "mismatch!\n",
1365                                                 task->tk_pid, __FUNCTION__);
1366                                 error = -EPROTONOSUPPORT;
1367                                 goto out_err;
1368                         default:
1369                                 dprintk("RPC: %5u %s: RPC call rejected, "
1370                                                 "unknown error: %x\n",
1371                                                 task->tk_pid, __FUNCTION__, n);
1372                                 goto out_eio;
1373                 }
1374                 if (--len < 0)
1375                         goto out_overflow;
1376                 switch ((n = ntohl(*p++))) {
1377                 case RPC_AUTH_REJECTEDCRED:
1378                 case RPC_AUTH_REJECTEDVERF:
1379                 case RPCSEC_GSS_CREDPROBLEM:
1380                 case RPCSEC_GSS_CTXPROBLEM:
1381                         if (!task->tk_cred_retry)
1382                                 break;
1383                         task->tk_cred_retry--;
1384                         dprintk("RPC: %5u %s: retry stale creds\n",
1385                                         task->tk_pid, __FUNCTION__);
1386                         rpcauth_invalcred(task);
1387                         task->tk_action = call_refresh;
1388                         goto out_retry;
1389                 case RPC_AUTH_BADCRED:
1390                 case RPC_AUTH_BADVERF:
1391                         /* possibly garbled cred/verf? */
1392                         if (!task->tk_garb_retry)
1393                                 break;
1394                         task->tk_garb_retry--;
1395                         dprintk("RPC: %5u %s: retry garbled creds\n",
1396                                         task->tk_pid, __FUNCTION__);
1397                         task->tk_action = call_bind;
1398                         goto out_retry;
1399                 case RPC_AUTH_TOOWEAK:
1400                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1401                                "authentication.\n", task->tk_client->cl_server);
1402                         break;
1403                 default:
1404                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1405                                         task->tk_pid, __FUNCTION__, n);
1406                         error = -EIO;
1407                 }
1408                 dprintk("RPC: %5u %s: call rejected %d\n",
1409                                 task->tk_pid, __FUNCTION__, n);
1410                 goto out_err;
1411         }
1412         if (!(p = rpcauth_checkverf(task, p))) {
1413                 dprintk("RPC: %5u %s: auth check failed\n",
1414                                 task->tk_pid, __FUNCTION__);
1415                 goto out_garbage;               /* bad verifier, retry */
1416         }
1417         len = p - (__be32 *)iov->iov_base - 1;
1418         if (len < 0)
1419                 goto out_overflow;
1420         switch ((n = ntohl(*p++))) {
1421         case RPC_SUCCESS:
1422                 return p;
1423         case RPC_PROG_UNAVAIL:
1424                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1425                                 task->tk_pid, __FUNCTION__,
1426                                 (unsigned int)task->tk_client->cl_prog,
1427                                 task->tk_client->cl_server);
1428                 error = -EPFNOSUPPORT;
1429                 goto out_err;
1430         case RPC_PROG_MISMATCH:
1431                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1432                                 "server %s\n", task->tk_pid, __FUNCTION__,
1433                                 (unsigned int)task->tk_client->cl_prog,
1434                                 (unsigned int)task->tk_client->cl_vers,
1435                                 task->tk_client->cl_server);
1436                 error = -EPROTONOSUPPORT;
1437                 goto out_err;
1438         case RPC_PROC_UNAVAIL:
1439                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1440                                 "version %u on server %s\n",
1441                                 task->tk_pid, __FUNCTION__,
1442                                 task->tk_msg.rpc_proc,
1443                                 task->tk_client->cl_prog,
1444                                 task->tk_client->cl_vers,
1445                                 task->tk_client->cl_server);
1446                 error = -EOPNOTSUPP;
1447                 goto out_err;
1448         case RPC_GARBAGE_ARGS:
1449                 dprintk("RPC: %5u %s: server saw garbage\n",
1450                                 task->tk_pid, __FUNCTION__);
1451                 break;                  /* retry */
1452         default:
1453                 dprintk("RPC: %5u %s: server accept status: %x\n",
1454                                 task->tk_pid, __FUNCTION__, n);
1455                 /* Also retry */
1456         }
1457
1458 out_garbage:
1459         task->tk_client->cl_stats->rpcgarbage++;
1460         if (task->tk_garb_retry) {
1461                 task->tk_garb_retry--;
1462                 dprintk("RPC: %5u %s: retrying\n",
1463                                 task->tk_pid, __FUNCTION__);
1464                 task->tk_action = call_bind;
1465 out_retry:
1466                 return ERR_PTR(-EAGAIN);
1467         }
1468 out_eio:
1469         error = -EIO;
1470 out_err:
1471         rpc_exit(task, error);
1472         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1473                         __FUNCTION__, error);
1474         return ERR_PTR(error);
1475 out_overflow:
1476         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1477                         __FUNCTION__);
1478         goto out_garbage;
1479 }
1480
1481 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1482 {
1483         return 0;
1484 }
1485
1486 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1487 {
1488         return 0;
1489 }
1490
1491 static struct rpc_procinfo rpcproc_null = {
1492         .p_encode = rpcproc_encode_null,
1493         .p_decode = rpcproc_decode_null,
1494 };
1495
1496 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1497 {
1498         struct rpc_message msg = {
1499                 .rpc_proc = &rpcproc_null,
1500         };
1501         int err;
1502         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1503         err = rpc_call_sync(clnt, &msg, flags);
1504         put_rpccred(msg.rpc_cred);
1505         return err;
1506 }
1507
1508 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1509 {
1510         struct rpc_message msg = {
1511                 .rpc_proc = &rpcproc_null,
1512                 .rpc_cred = cred,
1513         };
1514         return rpc_do_run_task(clnt, &msg, flags, &rpc_default_ops, NULL);
1515 }
1516 EXPORT_SYMBOL(rpc_call_null);
1517
1518 #ifdef RPC_DEBUG
1519 void rpc_show_tasks(void)
1520 {
1521         struct rpc_clnt *clnt;
1522         struct rpc_task *t;
1523
1524         spin_lock(&rpc_client_lock);
1525         if (list_empty(&all_clients))
1526                 goto out;
1527         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1528                 "-rpcwait -action- ---ops--\n");
1529         list_for_each_entry(clnt, &all_clients, cl_clients) {
1530                 if (list_empty(&clnt->cl_tasks))
1531                         continue;
1532                 spin_lock(&clnt->cl_lock);
1533                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1534                         const char *rpc_waitq = "none";
1535                         int proc;
1536
1537                         if (t->tk_msg.rpc_proc)
1538                                 proc = t->tk_msg.rpc_proc->p_proc;
1539                         else
1540                                 proc = -1;
1541
1542                         if (RPC_IS_QUEUED(t))
1543                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1544
1545                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1546                                 t->tk_pid, proc,
1547                                 t->tk_flags, t->tk_status,
1548                                 t->tk_client,
1549                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1550                                 t->tk_rqstp, t->tk_timeout,
1551                                 rpc_waitq,
1552                                 t->tk_action, t->tk_ops);
1553                 }
1554                 spin_unlock(&clnt->cl_lock);
1555         }
1556 out:
1557         spin_unlock(&rpc_client_lock);
1558 }
1559 #endif