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/kallsyms.h>
  29 #include <linux/mm.h>
  30 #include <linux/slab.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/utsname.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/in6.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40
  41 #include "sunrpc.h"
  42
  43 #ifdef RPC_DEBUG
  44 # define RPCDBG_FACILITY        RPCDBG_CALL
  45 #endif
  46
  47 #define dprint_status(t)                                        \
  48         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  49                         __func__, t->tk_status)
  50
  51 /*
  52  * All RPC clients are linked into this list
  53  */
  54 static LIST_HEAD(all_clients);
  55 static DEFINE_SPINLOCK(rpc_client_lock);
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_NFS_V4_1)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_NFS_V4_1 */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         spin_lock(&rpc_client_lock);
  86         list_add(&clnt->cl_clients, &all_clients);
  87         spin_unlock(&rpc_client_lock);
  88 }
  89
  90 static void rpc_unregister_client(struct rpc_clnt *clnt)
  91 {
  92         spin_lock(&rpc_client_lock);
  93         list_del(&clnt->cl_clients);
  94         spin_unlock(&rpc_client_lock);
  95 }
  96
  97 static int
  98 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  99 {
 100         static uint32_t clntid;
 101         int error;
 102
 103         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
 104         clnt->cl_dentry = ERR_PTR(-ENOENT);
 105         if (dir_name == NULL)
 106                 return 0;
 107
 108         clnt->cl_vfsmnt = rpc_get_mount();
 109         if (IS_ERR(clnt->cl_vfsmnt))
 110                 return PTR_ERR(clnt->cl_vfsmnt);
 111
 112         for (;;) {
 113                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 114                                 "%s/clnt%x", dir_name,
 115                                 (unsigned int)clntid++);
 116                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 117                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 118                 if (!IS_ERR(clnt->cl_dentry))
 119                         return 0;
 120                 error = PTR_ERR(clnt->cl_dentry);
 121                 if (error != -EEXIST) {
 122                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 123                                         clnt->cl_pathname, error);
 124                         rpc_put_mount();
 125                         return error;
 126                 }
 127         }
 128 }
 129
 130 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 131 {
 132         struct rpc_program      *program = args->program;
 133         struct rpc_version      *version;
 134         struct rpc_clnt         *clnt = NULL;
 135         struct rpc_auth         *auth;
 136         int err;
 137         size_t len;
 138
 139         /* sanity check the name before trying to print it */
 140         err = -EINVAL;
 141         len = strlen(args->servername);
 142         if (len > RPC_MAXNETNAMELEN)
 143                 goto out_no_rpciod;
 144         len++;
 145
 146         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 147                         program->name, args->servername, xprt);
 148
 149         err = rpciod_up();
 150         if (err)
 151                 goto out_no_rpciod;
 152         err = -EINVAL;
 153         if (!xprt)
 154                 goto out_no_xprt;
 155
 156         if (args->version >= program->nrvers)
 157                 goto out_err;
 158         version = program->version[args->version];
 159         if (version == NULL)
 160                 goto out_err;
 161
 162         err = -ENOMEM;
 163         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 164         if (!clnt)
 165                 goto out_err;
 166         clnt->cl_parent = clnt;
 167
 168         clnt->cl_server = clnt->cl_inline_name;
 169         if (len > sizeof(clnt->cl_inline_name)) {
 170                 char *buf = kmalloc(len, GFP_KERNEL);
 171                 if (buf != NULL)
 172                         clnt->cl_server = buf;
 173                 else
 174                         len = sizeof(clnt->cl_inline_name);
 175         }
 176         strlcpy(clnt->cl_server, args->servername, len);
 177
 178         clnt->cl_xprt     = xprt;
 179         clnt->cl_procinfo = version->procs;
 180         clnt->cl_maxproc  = version->nrprocs;
 181         clnt->cl_protname = program->name;
 182         clnt->cl_prog     = args->prognumber ? : program->number;
 183         clnt->cl_vers     = version->number;
 184         clnt->cl_stats    = program->stats;
 185         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 186         err = -ENOMEM;
 187         if (clnt->cl_metrics == NULL)
 188                 goto out_no_stats;
 189         clnt->cl_program  = program;
 190         INIT_LIST_HEAD(&clnt->cl_tasks);
 191         spin_lock_init(&clnt->cl_lock);
 192
 193         if (!xprt_bound(clnt->cl_xprt))
 194                 clnt->cl_autobind = 1;
 195
 196         clnt->cl_timeout = xprt->timeout;
 197         if (args->timeout != NULL) {
 198                 memcpy(&clnt->cl_timeout_default, args->timeout,
 199                                 sizeof(clnt->cl_timeout_default));
 200                 clnt->cl_timeout = &clnt->cl_timeout_default;
 201         }
 202
 203         clnt->cl_rtt = &clnt->cl_rtt_default;
 204         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 205         clnt->cl_principal = NULL;
 206         if (args->client_name) {
 207                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 208                 if (!clnt->cl_principal)
 209                         goto out_no_principal;
 210         }
 211
 212         kref_init(&clnt->cl_kref);
 213
 214         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 215         if (err < 0)
 216                 goto out_no_path;
 217
 218         auth = rpcauth_create(args->authflavor, clnt);
 219         if (IS_ERR(auth)) {
 220                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 221                                 args->authflavor);
 222                 err = PTR_ERR(auth);
 223                 goto out_no_auth;
 224         }
 225
 226         /* save the nodename */
 227         clnt->cl_nodelen = strlen(init_utsname()->nodename);
 228         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 229                 clnt->cl_nodelen = UNX_MAXNODENAME;
 230         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
 231         rpc_register_client(clnt);
 232         return clnt;
 233
 234 out_no_auth:
 235         if (!IS_ERR(clnt->cl_dentry)) {
 236                 rpc_rmdir(clnt->cl_dentry);
 237                 rpc_put_mount();
 238         }
 239 out_no_path:
 240         kfree(clnt->cl_principal);
 241 out_no_principal:
 242         rpc_free_iostats(clnt->cl_metrics);
 243 out_no_stats:
 244         if (clnt->cl_server != clnt->cl_inline_name)
 245                 kfree(clnt->cl_server);
 246         kfree(clnt);
 247 out_err:
 248         xprt_put(xprt);
 249 out_no_xprt:
 250         rpciod_down();
 251 out_no_rpciod:
 252         return ERR_PTR(err);
 253 }
 254
 255 /*
 256  * rpc_create - create an RPC client and transport with one call
 257  * @args: rpc_clnt create argument structure
 258  *
 259  * Creates and initializes an RPC transport and an RPC client.
 260  *
 261  * It can ping the server in order to determine if it is up, and to see if
 262  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 263  * this behavior so asynchronous tasks can also use rpc_create.
 264  */
 265 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 266 {
 267         struct rpc_xprt *xprt;
 268         struct rpc_clnt *clnt;
 269         struct xprt_create xprtargs = {
 270                 .ident = args->protocol,
 271                 .srcaddr = args->saddress,
 272                 .dstaddr = args->address,
 273                 .addrlen = args->addrsize,
 274         };
 275         char servername[48];
 276
 277         /*
 278          * If the caller chooses not to specify a hostname, whip
 279          * up a string representation of the passed-in address.
 280          */
 281         if (args->servername == NULL) {
 282                 servername[0] = '\0';
 283                 switch (args->address->sa_family) {
 284                 case AF_INET: {
 285                         struct sockaddr_in *sin =
 286                                         (struct sockaddr_in *)args->address;
 287                         snprintf(servername, sizeof(servername), "%pI4",
 288                                  &sin->sin_addr.s_addr);
 289                         break;
 290                 }
 291                 case AF_INET6: {
 292                         struct sockaddr_in6 *sin =
 293                                         (struct sockaddr_in6 *)args->address;
 294                         snprintf(servername, sizeof(servername), "%pI6",
 295                                  &sin->sin6_addr);
 296                         break;
 297                 }
 298                 default:
 299                         /* caller wants default server name, but
 300                          * address family isn't recognized. */
 301                         return ERR_PTR(-EINVAL);
 302                 }
 303                 args->servername = servername;
 304         }
 305
 306         xprt = xprt_create_transport(&xprtargs);
 307         if (IS_ERR(xprt))
 308                 return (struct rpc_clnt *)xprt;
 309
 310         /*
 311          * By default, kernel RPC client connects from a reserved port.
 312          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 313          * but it is always enabled for rpciod, which handles the connect
 314          * operation.
 315          */
 316         xprt->resvport = 1;
 317         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 318                 xprt->resvport = 0;
 319
 320         clnt = rpc_new_client(args, xprt);
 321         if (IS_ERR(clnt))
 322                 return clnt;
 323
 324         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 325                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 326                 if (err != 0) {
 327                         rpc_shutdown_client(clnt);
 328                         return ERR_PTR(err);
 329                 }
 330         }
 331
 332         clnt->cl_softrtry = 1;
 333         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 334                 clnt->cl_softrtry = 0;
 335
 336         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 337                 clnt->cl_autobind = 1;
 338         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 339                 clnt->cl_discrtry = 1;
 340         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 341                 clnt->cl_chatty = 1;
 342
 343         return clnt;
 344 }
 345 EXPORT_SYMBOL_GPL(rpc_create);
 346
 347 /*
 348  * This function clones the RPC client structure. It allows us to share the
 349  * same transport while varying parameters such as the authentication
 350  * flavour.
 351  */
 352 struct rpc_clnt *
 353 rpc_clone_client(struct rpc_clnt *clnt)
 354 {
 355         struct rpc_clnt *new;
 356         int err = -ENOMEM;
 357
 358         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 359         if (!new)
 360                 goto out_no_clnt;
 361         new->cl_parent = clnt;
 362         /* Turn off autobind on clones */
 363         new->cl_autobind = 0;
 364         INIT_LIST_HEAD(&new->cl_tasks);
 365         spin_lock_init(&new->cl_lock);
 366         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 367         new->cl_metrics = rpc_alloc_iostats(clnt);
 368         if (new->cl_metrics == NULL)
 369                 goto out_no_stats;
 370         if (clnt->cl_principal) {
 371                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 372                 if (new->cl_principal == NULL)
 373                         goto out_no_principal;
 374         }
 375         kref_init(&new->cl_kref);
 376         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 377         if (err != 0)
 378                 goto out_no_path;
 379         if (new->cl_auth)
 380                 atomic_inc(&new->cl_auth->au_count);
 381         xprt_get(clnt->cl_xprt);
 382         kref_get(&clnt->cl_kref);
 383         rpc_register_client(new);
 384         rpciod_up();
 385         return new;
 386 out_no_path:
 387         kfree(new->cl_principal);
 388 out_no_principal:
 389         rpc_free_iostats(new->cl_metrics);
 390 out_no_stats:
 391         kfree(new);
 392 out_no_clnt:
 393         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 394         return ERR_PTR(err);
 395 }
 396 EXPORT_SYMBOL_GPL(rpc_clone_client);
 397
 398 /*
 399  * Properly shut down an RPC client, terminating all outstanding
 400  * requests.
 401  */
 402 void rpc_shutdown_client(struct rpc_clnt *clnt)
 403 {
 404         dprintk("RPC:       shutting down %s client for %s\n",
 405                         clnt->cl_protname, clnt->cl_server);
 406
 407         while (!list_empty(&clnt->cl_tasks)) {
 408                 rpc_killall_tasks(clnt);
 409                 wait_event_timeout(destroy_wait,
 410                         list_empty(&clnt->cl_tasks), 1*HZ);
 411         }
 412
 413         rpc_release_client(clnt);
 414 }
 415 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 416
 417 /*
 418  * Free an RPC client
 419  */
 420 static void
 421 rpc_free_client(struct kref *kref)
 422 {
 423         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 424
 425         dprintk("RPC:       destroying %s client for %s\n",
 426                         clnt->cl_protname, clnt->cl_server);
 427         if (!IS_ERR(clnt->cl_dentry)) {
 428                 rpc_rmdir(clnt->cl_dentry);
 429                 rpc_put_mount();
 430         }
 431         if (clnt->cl_parent != clnt) {
 432                 rpc_release_client(clnt->cl_parent);
 433                 goto out_free;
 434         }
 435         if (clnt->cl_server != clnt->cl_inline_name)
 436                 kfree(clnt->cl_server);
 437 out_free:
 438         rpc_unregister_client(clnt);
 439         rpc_free_iostats(clnt->cl_metrics);
 440         kfree(clnt->cl_principal);
 441         clnt->cl_metrics = NULL;
 442         xprt_put(clnt->cl_xprt);
 443         rpciod_down();
 444         kfree(clnt);
 445 }
 446
 447 /*
 448  * Free an RPC client
 449  */
 450 static void
 451 rpc_free_auth(struct kref *kref)
 452 {
 453         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 454
 455         if (clnt->cl_auth == NULL) {
 456                 rpc_free_client(kref);
 457                 return;
 458         }
 459
 460         /*
 461          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 462          *       release remaining GSS contexts. This mechanism ensures
 463          *       that it can do so safely.
 464          */
 465         kref_init(kref);
 466         rpcauth_release(clnt->cl_auth);
 467         clnt->cl_auth = NULL;
 468         kref_put(kref, rpc_free_client);
 469 }
 470
 471 /*
 472  * Release reference to the RPC client
 473  */
 474 void
 475 rpc_release_client(struct rpc_clnt *clnt)
 476 {
 477         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 478
 479         if (list_empty(&clnt->cl_tasks))
 480                 wake_up(&destroy_wait);
 481         kref_put(&clnt->cl_kref, rpc_free_auth);
 482 }
 483
 484 /**
 485  * rpc_bind_new_program - bind a new RPC program to an existing client
 486  * @old: old rpc_client
 487  * @program: rpc program to set
 488  * @vers: rpc program version
 489  *
 490  * Clones the rpc client and sets up a new RPC program. This is mainly
 491  * of use for enabling different RPC programs to share the same transport.
 492  * The Sun NFSv2/v3 ACL protocol can do this.
 493  */
 494 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 495                                       struct rpc_program *program,
 496                                       u32 vers)
 497 {
 498         struct rpc_clnt *clnt;
 499         struct rpc_version *version;
 500         int err;
 501
 502         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 503         version = program->version[vers];
 504         clnt = rpc_clone_client(old);
 505         if (IS_ERR(clnt))
 506                 goto out;
 507         clnt->cl_procinfo = version->procs;
 508         clnt->cl_maxproc  = version->nrprocs;
 509         clnt->cl_protname = program->name;
 510         clnt->cl_prog     = program->number;
 511         clnt->cl_vers     = version->number;
 512         clnt->cl_stats    = program->stats;
 513         err = rpc_ping(clnt, RPC_TASK_SOFT);
 514         if (err != 0) {
 515                 rpc_shutdown_client(clnt);
 516                 clnt = ERR_PTR(err);
 517         }
 518 out:
 519         return clnt;
 520 }
 521 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 522
 523 /*
 524  * Default callback for async RPC calls
 525  */
 526 static void
 527 rpc_default_callback(struct rpc_task *task, void *data)
 528 {
 529 }
 530
 531 static const struct rpc_call_ops rpc_default_ops = {
 532         .rpc_call_done = rpc_default_callback,
 533 };
 534
 535 /**
 536  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 537  * @task_setup_data: pointer to task initialisation data
 538  */
 539 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 540 {
 541         struct rpc_task *task, *ret;
 542
 543         task = rpc_new_task(task_setup_data);
 544         if (task == NULL) {
 545                 rpc_release_calldata(task_setup_data->callback_ops,
 546                                 task_setup_data->callback_data);
 547                 ret = ERR_PTR(-ENOMEM);
 548                 goto out;
 549         }
 550
 551         if (task->tk_status != 0) {
 552                 ret = ERR_PTR(task->tk_status);
 553                 rpc_put_task(task);
 554                 goto out;
 555         }
 556         atomic_inc(&task->tk_count);
 557         rpc_execute(task);
 558         ret = task;
 559 out:
 560         return ret;
 561 }
 562 EXPORT_SYMBOL_GPL(rpc_run_task);
 563
 564 /**
 565  * rpc_call_sync - Perform a synchronous RPC call
 566  * @clnt: pointer to RPC client
 567  * @msg: RPC call parameters
 568  * @flags: RPC call flags
 569  */
 570 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 571 {
 572         struct rpc_task *task;
 573         struct rpc_task_setup task_setup_data = {
 574                 .rpc_client = clnt,
 575                 .rpc_message = msg,
 576                 .callback_ops = &rpc_default_ops,
 577                 .flags = flags,
 578         };
 579         int status;
 580
 581         BUG_ON(flags & RPC_TASK_ASYNC);
 582
 583         task = rpc_run_task(&task_setup_data);
 584         if (IS_ERR(task))
 585                 return PTR_ERR(task);
 586         status = task->tk_status;
 587         rpc_put_task(task);
 588         return status;
 589 }
 590 EXPORT_SYMBOL_GPL(rpc_call_sync);
 591
 592 /**
 593  * rpc_call_async - Perform an asynchronous RPC call
 594  * @clnt: pointer to RPC client
 595  * @msg: RPC call parameters
 596  * @flags: RPC call flags
 597  * @tk_ops: RPC call ops
 598  * @data: user call data
 599  */
 600 int
 601 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 602                const struct rpc_call_ops *tk_ops, void *data)
 603 {
 604         struct rpc_task *task;
 605         struct rpc_task_setup task_setup_data = {
 606                 .rpc_client = clnt,
 607                 .rpc_message = msg,
 608                 .callback_ops = tk_ops,
 609                 .callback_data = data,
 610                 .flags = flags|RPC_TASK_ASYNC,
 611         };
 612
 613         task = rpc_run_task(&task_setup_data);
 614         if (IS_ERR(task))
 615                 return PTR_ERR(task);
 616         rpc_put_task(task);
 617         return 0;
 618 }
 619 EXPORT_SYMBOL_GPL(rpc_call_async);
 620
 621 #if defined(CONFIG_NFS_V4_1)
 622 /**
 623  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 624  * rpc_execute against it
 625  * @ops: RPC call ops
 626  */
 627 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 628                                         const struct rpc_call_ops *tk_ops)
 629 {
 630         struct rpc_task *task;
 631         struct xdr_buf *xbufp = &req->rq_snd_buf;
 632         struct rpc_task_setup task_setup_data = {
 633                 .callback_ops = tk_ops,
 634         };
 635
 636         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 637         /*
 638          * Create an rpc_task to send the data
 639          */
 640         task = rpc_new_task(&task_setup_data);
 641         if (!task) {
 642                 xprt_free_bc_request(req);
 643                 goto out;
 644         }
 645         task->tk_rqstp = req;
 646
 647         /*
 648          * Set up the xdr_buf length.
 649          * This also indicates that the buffer is XDR encoded already.
 650          */
 651         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 652                         xbufp->tail[0].iov_len;
 653
 654         task->tk_action = call_bc_transmit;
 655         atomic_inc(&task->tk_count);
 656         BUG_ON(atomic_read(&task->tk_count) != 2);
 657         rpc_execute(task);
 658
 659 out:
 660         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 661         return task;
 662 }
 663 #endif /* CONFIG_NFS_V4_1 */
 664
 665 void
 666 rpc_call_start(struct rpc_task *task)
 667 {
 668         task->tk_action = call_start;
 669 }
 670 EXPORT_SYMBOL_GPL(rpc_call_start);
 671
 672 /**
 673  * rpc_peeraddr - extract remote peer address from clnt's xprt
 674  * @clnt: RPC client structure
 675  * @buf: target buffer
 676  * @bufsize: length of target buffer
 677  *
 678  * Returns the number of bytes that are actually in the stored address.
 679  */
 680 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 681 {
 682         size_t bytes;
 683         struct rpc_xprt *xprt = clnt->cl_xprt;
 684
 685         bytes = sizeof(xprt->addr);
 686         if (bytes > bufsize)
 687                 bytes = bufsize;
 688         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 689         return xprt->addrlen;
 690 }
 691 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 692
 693 /**
 694  * rpc_peeraddr2str - return remote peer address in printable format
 695  * @clnt: RPC client structure
 696  * @format: address format
 697  *
 698  */
 699 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 700                              enum rpc_display_format_t format)
 701 {
 702         struct rpc_xprt *xprt = clnt->cl_xprt;
 703
 704         if (xprt->address_strings[format] != NULL)
 705                 return xprt->address_strings[format];
 706         else
 707                 return "unprintable";
 708 }
 709 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 710
 711 void
 712 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 713 {
 714         struct rpc_xprt *xprt = clnt->cl_xprt;
 715         if (xprt->ops->set_buffer_size)
 716                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 717 }
 718 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 719
 720 /*
 721  * Return size of largest payload RPC client can support, in bytes
 722  *
 723  * For stream transports, this is one RPC record fragment (see RFC
 724  * 1831), as we don't support multi-record requests yet.  For datagram
 725  * transports, this is the size of an IP packet minus the IP, UDP, and
 726  * RPC header sizes.
 727  */
 728 size_t rpc_max_payload(struct rpc_clnt *clnt)
 729 {
 730         return clnt->cl_xprt->max_payload;
 731 }
 732 EXPORT_SYMBOL_GPL(rpc_max_payload);
 733
 734 /**
 735  * rpc_force_rebind - force transport to check that remote port is unchanged
 736  * @clnt: client to rebind
 737  *
 738  */
 739 void rpc_force_rebind(struct rpc_clnt *clnt)
 740 {
 741         if (clnt->cl_autobind)
 742                 xprt_clear_bound(clnt->cl_xprt);
 743 }
 744 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 745
 746 /*
 747  * Restart an (async) RPC call from the call_prepare state.
 748  * Usually called from within the exit handler.
 749  */
 750 void
 751 rpc_restart_call_prepare(struct rpc_task *task)
 752 {
 753         if (RPC_ASSASSINATED(task))
 754                 return;
 755         task->tk_action = rpc_prepare_task;
 756 }
 757 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 758
 759 /*
 760  * Restart an (async) RPC call. Usually called from within the
 761  * exit handler.
 762  */
 763 void
 764 rpc_restart_call(struct rpc_task *task)
 765 {
 766         if (RPC_ASSASSINATED(task))
 767                 return;
 768
 769         task->tk_action = call_start;
 770 }
 771 EXPORT_SYMBOL_GPL(rpc_restart_call);
 772
 773 #ifdef RPC_DEBUG
 774 static const char *rpc_proc_name(const struct rpc_task *task)
 775 {
 776         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 777
 778         if (proc) {
 779                 if (proc->p_name)
 780                         return proc->p_name;
 781                 else
 782                         return "NULL";
 783         } else
 784                 return "no proc";
 785 }
 786 #endif
 787
 788 /*
 789  * 0.  Initial state
 790  *
 791  *     Other FSM states can be visited zero or more times, but
 792  *     this state is visited exactly once for each RPC.
 793  */
 794 static void
 795 call_start(struct rpc_task *task)
 796 {
 797         struct rpc_clnt *clnt = task->tk_client;
 798
 799         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 800                         clnt->cl_protname, clnt->cl_vers,
 801                         rpc_proc_name(task),
 802                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 803
 804         /* Increment call count */
 805         task->tk_msg.rpc_proc->p_count++;
 806         clnt->cl_stats->rpccnt++;
 807         task->tk_action = call_reserve;
 808 }
 809
 810 /*
 811  * 1.   Reserve an RPC call slot
 812  */
 813 static void
 814 call_reserve(struct rpc_task *task)
 815 {
 816         dprint_status(task);
 817
 818         if (!rpcauth_uptodatecred(task)) {
 819                 task->tk_action = call_refresh;
 820                 return;
 821         }
 822
 823         task->tk_status  = 0;
 824         task->tk_action  = call_reserveresult;
 825         xprt_reserve(task);
 826 }
 827
 828 /*
 829  * 1b.  Grok the result of xprt_reserve()
 830  */
 831 static void
 832 call_reserveresult(struct rpc_task *task)
 833 {
 834         int status = task->tk_status;
 835
 836         dprint_status(task);
 837
 838         /*
 839          * After a call to xprt_reserve(), we must have either
 840          * a request slot or else an error status.
 841          */
 842         task->tk_status = 0;
 843         if (status >= 0) {
 844                 if (task->tk_rqstp) {
 845                         task->tk_action = call_allocate;
 846                         return;
 847                 }
 848
 849                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 850                                 __func__, status);
 851                 rpc_exit(task, -EIO);
 852                 return;
 853         }
 854
 855         /*
 856          * Even though there was an error, we may have acquired
 857          * a request slot somehow.  Make sure not to leak it.
 858          */
 859         if (task->tk_rqstp) {
 860                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 861                                 __func__, status);
 862                 xprt_release(task);
 863         }
 864
 865         switch (status) {
 866         case -EAGAIN:   /* woken up; retry */
 867                 task->tk_action = call_reserve;
 868                 return;
 869         case -EIO:      /* probably a shutdown */
 870                 break;
 871         default:
 872                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 873                                 __func__, status);
 874                 break;
 875         }
 876         rpc_exit(task, status);
 877 }
 878
 879 /*
 880  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 881  *      (Note: buffer memory is freed in xprt_release).
 882  */
 883 static void
 884 call_allocate(struct rpc_task *task)
 885 {
 886         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 887         struct rpc_rqst *req = task->tk_rqstp;
 888         struct rpc_xprt *xprt = task->tk_xprt;
 889         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 890
 891         dprint_status(task);
 892
 893         task->tk_status = 0;
 894         task->tk_action = call_bind;
 895
 896         if (req->rq_buffer)
 897                 return;
 898
 899         if (proc->p_proc != 0) {
 900                 BUG_ON(proc->p_arglen == 0);
 901                 if (proc->p_decode != NULL)
 902                         BUG_ON(proc->p_replen == 0);
 903         }
 904
 905         /*
 906          * Calculate the size (in quads) of the RPC call
 907          * and reply headers, and convert both values
 908          * to byte sizes.
 909          */
 910         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 911         req->rq_callsize <<= 2;
 912         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 913         req->rq_rcvsize <<= 2;
 914
 915         req->rq_buffer = xprt->ops->buf_alloc(task,
 916                                         req->rq_callsize + req->rq_rcvsize);
 917         if (req->rq_buffer != NULL)
 918                 return;
 919
 920         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 921
 922         if (RPC_IS_ASYNC(task) || !signalled()) {
 923                 task->tk_action = call_allocate;
 924                 rpc_delay(task, HZ>>4);
 925                 return;
 926         }
 927
 928         rpc_exit(task, -ERESTARTSYS);
 929 }
 930
 931 static inline int
 932 rpc_task_need_encode(struct rpc_task *task)
 933 {
 934         return task->tk_rqstp->rq_snd_buf.len == 0;
 935 }
 936
 937 static inline void
 938 rpc_task_force_reencode(struct rpc_task *task)
 939 {
 940         task->tk_rqstp->rq_snd_buf.len = 0;
 941 }
 942
 943 static inline void
 944 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 945 {
 946         buf->head[0].iov_base = start;
 947         buf->head[0].iov_len = len;
 948         buf->tail[0].iov_len = 0;
 949         buf->page_len = 0;
 950         buf->flags = 0;
 951         buf->len = 0;
 952         buf->buflen = len;
 953 }
 954
 955 /*
 956  * 3.   Encode arguments of an RPC call
 957  */
 958 static void
 959 rpc_xdr_encode(struct rpc_task *task)
 960 {
 961         struct rpc_rqst *req = task->tk_rqstp;
 962         kxdrproc_t      encode;
 963         __be32          *p;
 964
 965         dprint_status(task);
 966
 967         rpc_xdr_buf_init(&req->rq_snd_buf,
 968                          req->rq_buffer,
 969                          req->rq_callsize);
 970         rpc_xdr_buf_init(&req->rq_rcv_buf,
 971                          (char *)req->rq_buffer + req->rq_callsize,
 972                          req->rq_rcvsize);
 973
 974         p = rpc_encode_header(task);
 975         if (p == NULL) {
 976                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 977                 rpc_exit(task, -EIO);
 978                 return;
 979         }
 980
 981         encode = task->tk_msg.rpc_proc->p_encode;
 982         if (encode == NULL)
 983                 return;
 984
 985         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 986                         task->tk_msg.rpc_argp);
 987 }
 988
 989 /*
 990  * 4.   Get the server port number if not yet set
 991  */
 992 static void
 993 call_bind(struct rpc_task *task)
 994 {
 995         struct rpc_xprt *xprt = task->tk_xprt;
 996
 997         dprint_status(task);
 998
 999         task->tk_action = call_connect;
1000         if (!xprt_bound(xprt)) {
1001                 task->tk_action = call_bind_status;
1002                 task->tk_timeout = xprt->bind_timeout;
1003                 xprt->ops->rpcbind(task);
1004         }
1005 }
1006
1007 /*
1008  * 4a.  Sort out bind result
1009  */
1010 static void
1011 call_bind_status(struct rpc_task *task)
1012 {
1013         int status = -EIO;
1014
1015         if (task->tk_status >= 0) {
1016                 dprint_status(task);
1017                 task->tk_status = 0;
1018                 task->tk_action = call_connect;
1019                 return;
1020         }
1021
1022         switch (task->tk_status) {
1023         case -ENOMEM:
1024                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1025                 rpc_delay(task, HZ >> 2);
1026                 goto retry_timeout;
1027         case -EACCES:
1028                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1029                                 "unavailable\n", task->tk_pid);
1030                 /* fail immediately if this is an RPC ping */
1031                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1032                         status = -EOPNOTSUPP;
1033                         break;
1034                 }
1035                 rpc_delay(task, 3*HZ);
1036                 goto retry_timeout;
1037         case -ETIMEDOUT:
1038                 dprintk("RPC: %5u rpcbind request timed out\n",
1039                                 task->tk_pid);
1040                 goto retry_timeout;
1041         case -EPFNOSUPPORT:
1042                 /* server doesn't support any rpcbind version we know of */
1043                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1044                                 task->tk_pid);
1045                 break;
1046         case -EPROTONOSUPPORT:
1047                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1048                                 task->tk_pid);
1049                 task->tk_status = 0;
1050                 task->tk_action = call_bind;
1051                 return;
1052         default:
1053                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1054                                 task->tk_pid, -task->tk_status);
1055         }
1056
1057         rpc_exit(task, status);
1058         return;
1059
1060 retry_timeout:
1061         task->tk_action = call_timeout;
1062 }
1063
1064 /*
1065  * 4b.  Connect to the RPC server
1066  */
1067 static void
1068 call_connect(struct rpc_task *task)
1069 {
1070         struct rpc_xprt *xprt = task->tk_xprt;
1071
1072         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1073                         task->tk_pid, xprt,
1074                         (xprt_connected(xprt) ? "is" : "is not"));
1075
1076         task->tk_action = call_transmit;
1077         if (!xprt_connected(xprt)) {
1078                 task->tk_action = call_connect_status;
1079                 if (task->tk_status < 0)
1080                         return;
1081                 xprt_connect(task);
1082         }
1083 }
1084
1085 /*
1086  * 4c.  Sort out connect result
1087  */
1088 static void
1089 call_connect_status(struct rpc_task *task)
1090 {
1091         struct rpc_clnt *clnt = task->tk_client;
1092         int status = task->tk_status;
1093
1094         dprint_status(task);
1095
1096         task->tk_status = 0;
1097         if (status >= 0 || status == -EAGAIN) {
1098                 clnt->cl_stats->netreconn++;
1099                 task->tk_action = call_transmit;
1100                 return;
1101         }
1102
1103         switch (status) {
1104                 /* if soft mounted, test if we've timed out */
1105         case -ETIMEDOUT:
1106                 task->tk_action = call_timeout;
1107                 break;
1108         default:
1109                 rpc_exit(task, -EIO);
1110         }
1111 }
1112
1113 /*
1114  * 5.   Transmit the RPC request, and wait for reply
1115  */
1116 static void
1117 call_transmit(struct rpc_task *task)
1118 {
1119         dprint_status(task);
1120
1121         task->tk_action = call_status;
1122         if (task->tk_status < 0)
1123                 return;
1124         task->tk_status = xprt_prepare_transmit(task);
1125         if (task->tk_status != 0)
1126                 return;
1127         task->tk_action = call_transmit_status;
1128         /* Encode here so that rpcsec_gss can use correct sequence number. */
1129         if (rpc_task_need_encode(task)) {
1130                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1131                 rpc_xdr_encode(task);
1132                 /* Did the encode result in an error condition? */
1133                 if (task->tk_status != 0) {
1134                         /* Was the error nonfatal? */
1135                         if (task->tk_status == -EAGAIN)
1136                                 rpc_delay(task, HZ >> 4);
1137                         else
1138                                 rpc_exit(task, task->tk_status);
1139                         return;
1140                 }
1141         }
1142         xprt_transmit(task);
1143         if (task->tk_status < 0)
1144                 return;
1145         /*
1146          * On success, ensure that we call xprt_end_transmit() before sleeping
1147          * in order to allow access to the socket to other RPC requests.
1148          */
1149         call_transmit_status(task);
1150         if (rpc_reply_expected(task))
1151                 return;
1152         task->tk_action = rpc_exit_task;
1153         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1154 }
1155
1156 /*
1157  * 5a.  Handle cleanup after a transmission
1158  */
1159 static void
1160 call_transmit_status(struct rpc_task *task)
1161 {
1162         task->tk_action = call_status;
1163         switch (task->tk_status) {
1164         case -EAGAIN:
1165                 break;
1166         default:
1167                 xprt_end_transmit(task);
1168                 /*
1169                  * Special cases: if we've been waiting on the
1170                  * socket's write_space() callback, or if the
1171                  * socket just returned a connection error,
1172                  * then hold onto the transport lock.
1173                  */
1174         case -ECONNREFUSED:
1175         case -ECONNRESET:
1176         case -ENOTCONN:
1177         case -EHOSTDOWN:
1178         case -EHOSTUNREACH:
1179         case -ENETUNREACH:
1180         case -EPIPE:
1181                 rpc_task_force_reencode(task);
1182         }
1183 }
1184
1185 #if defined(CONFIG_NFS_V4_1)
1186 /*
1187  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1188  * addition, disconnect on connectivity errors.
1189  */
1190 static void
1191 call_bc_transmit(struct rpc_task *task)
1192 {
1193         struct rpc_rqst *req = task->tk_rqstp;
1194
1195         BUG_ON(task->tk_status != 0);
1196         task->tk_status = xprt_prepare_transmit(task);
1197         if (task->tk_status == -EAGAIN) {
1198                 /*
1199                  * Could not reserve the transport. Try again after the
1200                  * transport is released.
1201                  */
1202                 task->tk_status = 0;
1203                 task->tk_action = call_bc_transmit;
1204                 return;
1205         }
1206
1207         task->tk_action = rpc_exit_task;
1208         if (task->tk_status < 0) {
1209                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1210                         "error: %d\n", task->tk_status);
1211                 return;
1212         }
1213
1214         xprt_transmit(task);
1215         xprt_end_transmit(task);
1216         dprint_status(task);
1217         switch (task->tk_status) {
1218         case 0:
1219                 /* Success */
1220                 break;
1221         case -EHOSTDOWN:
1222         case -EHOSTUNREACH:
1223         case -ENETUNREACH:
1224         case -ETIMEDOUT:
1225                 /*
1226                  * Problem reaching the server.  Disconnect and let the
1227                  * forechannel reestablish the connection.  The server will
1228                  * have to retransmit the backchannel request and we'll
1229                  * reprocess it.  Since these ops are idempotent, there's no
1230                  * need to cache our reply at this time.
1231                  */
1232                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1233                         "error: %d\n", task->tk_status);
1234                 xprt_conditional_disconnect(task->tk_xprt,
1235                         req->rq_connect_cookie);
1236                 break;
1237         default:
1238                 /*
1239                  * We were unable to reply and will have to drop the
1240                  * request.  The server should reconnect and retransmit.
1241                  */
1242                 BUG_ON(task->tk_status == -EAGAIN);
1243                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1244                         "error: %d\n", task->tk_status);
1245                 break;
1246         }
1247         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1248 }
1249 #endif /* CONFIG_NFS_V4_1 */
1250
1251 /*
1252  * 6.   Sort out the RPC call status
1253  */
1254 static void
1255 call_status(struct rpc_task *task)
1256 {
1257         struct rpc_clnt *clnt = task->tk_client;
1258         struct rpc_rqst *req = task->tk_rqstp;
1259         int             status;
1260
1261         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1262                 task->tk_status = req->rq_reply_bytes_recvd;
1263
1264         dprint_status(task);
1265
1266         status = task->tk_status;
1267         if (status >= 0) {
1268                 task->tk_action = call_decode;
1269                 return;
1270         }
1271
1272         task->tk_status = 0;
1273         switch(status) {
1274         case -EHOSTDOWN:
1275         case -EHOSTUNREACH:
1276         case -ENETUNREACH:
1277                 /*
1278                  * Delay any retries for 3 seconds, then handle as if it
1279                  * were a timeout.
1280                  */
1281                 rpc_delay(task, 3*HZ);
1282         case -ETIMEDOUT:
1283                 task->tk_action = call_timeout;
1284                 if (task->tk_client->cl_discrtry)
1285                         xprt_conditional_disconnect(task->tk_xprt,
1286                                         req->rq_connect_cookie);
1287                 break;
1288         case -ECONNRESET:
1289         case -ECONNREFUSED:
1290                 rpc_force_rebind(clnt);
1291                 rpc_delay(task, 3*HZ);
1292         case -EPIPE:
1293         case -ENOTCONN:
1294                 task->tk_action = call_bind;
1295                 break;
1296         case -EAGAIN:
1297                 task->tk_action = call_transmit;
1298                 break;
1299         case -EIO:
1300                 /* shutdown or soft timeout */
1301                 rpc_exit(task, status);
1302                 break;
1303         default:
1304                 if (clnt->cl_chatty)
1305                         printk("%s: RPC call returned error %d\n",
1306                                clnt->cl_protname, -status);
1307                 rpc_exit(task, status);
1308         }
1309 }
1310
1311 /*
1312  * 6a.  Handle RPC timeout
1313  *      We do not release the request slot, so we keep using the
1314  *      same XID for all retransmits.
1315  */
1316 static void
1317 call_timeout(struct rpc_task *task)
1318 {
1319         struct rpc_clnt *clnt = task->tk_client;
1320
1321         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1322                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1323                 goto retry;
1324         }
1325
1326         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1327         task->tk_timeouts++;
1328
1329         if (RPC_IS_SOFT(task)) {
1330                 if (clnt->cl_chatty)
1331                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1332                                 clnt->cl_protname, clnt->cl_server);
1333                 rpc_exit(task, -EIO);
1334                 return;
1335         }
1336
1337         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1338                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1339                 if (clnt->cl_chatty)
1340                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1341                         clnt->cl_protname, clnt->cl_server);
1342         }
1343         rpc_force_rebind(clnt);
1344         /*
1345          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1346          * event? RFC2203 requires the server to drop all such requests.
1347          */
1348         rpcauth_invalcred(task);
1349
1350 retry:
1351         clnt->cl_stats->rpcretrans++;
1352         task->tk_action = call_bind;
1353         task->tk_status = 0;
1354 }
1355
1356 /*
1357  * 7.   Decode the RPC reply
1358  */
1359 static void
1360 call_decode(struct rpc_task *task)
1361 {
1362         struct rpc_clnt *clnt = task->tk_client;
1363         struct rpc_rqst *req = task->tk_rqstp;
1364         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1365         __be32          *p;
1366
1367         dprintk("RPC: %5u call_decode (status %d)\n",
1368                         task->tk_pid, task->tk_status);
1369
1370         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1371                 if (clnt->cl_chatty)
1372                         printk(KERN_NOTICE "%s: server %s OK\n",
1373                                 clnt->cl_protname, clnt->cl_server);
1374                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1375         }
1376
1377         /*
1378          * Ensure that we see all writes made by xprt_complete_rqst()
1379          * before it changed req->rq_reply_bytes_recvd.
1380          */
1381         smp_rmb();
1382         req->rq_rcv_buf.len = req->rq_private_buf.len;
1383
1384         /* Check that the softirq receive buffer is valid */
1385         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1386                                 sizeof(req->rq_rcv_buf)) != 0);
1387
1388         if (req->rq_rcv_buf.len < 12) {
1389                 if (!RPC_IS_SOFT(task)) {
1390                         task->tk_action = call_bind;
1391                         clnt->cl_stats->rpcretrans++;
1392                         goto out_retry;
1393                 }
1394                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1395                                 clnt->cl_protname, task->tk_status);
1396                 task->tk_action = call_timeout;
1397                 goto out_retry;
1398         }
1399
1400         p = rpc_verify_header(task);
1401         if (IS_ERR(p)) {
1402                 if (p == ERR_PTR(-EAGAIN))
1403                         goto out_retry;
1404                 return;
1405         }
1406
1407         task->tk_action = rpc_exit_task;
1408
1409         if (decode) {
1410                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1411                                                       task->tk_msg.rpc_resp);
1412         }
1413         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1414                         task->tk_status);
1415         return;
1416 out_retry:
1417         task->tk_status = 0;
1418         /* Note: rpc_verify_header() may have freed the RPC slot */
1419         if (task->tk_rqstp == req) {
1420                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1421                 if (task->tk_client->cl_discrtry)
1422                         xprt_conditional_disconnect(task->tk_xprt,
1423                                         req->rq_connect_cookie);
1424         }
1425 }
1426
1427 /*
1428  * 8.   Refresh the credentials if rejected by the server
1429  */
1430 static void
1431 call_refresh(struct rpc_task *task)
1432 {
1433         dprint_status(task);
1434
1435         task->tk_action = call_refreshresult;
1436         task->tk_status = 0;
1437         task->tk_client->cl_stats->rpcauthrefresh++;
1438         rpcauth_refreshcred(task);
1439 }
1440
1441 /*
1442  * 8a.  Process the results of a credential refresh
1443  */
1444 static void
1445 call_refreshresult(struct rpc_task *task)
1446 {
1447         int status = task->tk_status;
1448
1449         dprint_status(task);
1450
1451         task->tk_status = 0;
1452         task->tk_action = call_reserve;
1453         if (status >= 0 && rpcauth_uptodatecred(task))
1454                 return;
1455         if (status == -EACCES) {
1456                 rpc_exit(task, -EACCES);
1457                 return;
1458         }
1459         task->tk_action = call_refresh;
1460         if (status != -ETIMEDOUT)
1461                 rpc_delay(task, 3*HZ);
1462         return;
1463 }
1464
1465 static __be32 *
1466 rpc_encode_header(struct rpc_task *task)
1467 {
1468         struct rpc_clnt *clnt = task->tk_client;
1469         struct rpc_rqst *req = task->tk_rqstp;
1470         __be32          *p = req->rq_svec[0].iov_base;
1471
1472         /* FIXME: check buffer size? */
1473
1474         p = xprt_skip_transport_header(task->tk_xprt, p);
1475         *p++ = req->rq_xid;             /* XID */
1476         *p++ = htonl(RPC_CALL);         /* CALL */
1477         *p++ = htonl(RPC_VERSION);      /* RPC version */
1478         *p++ = htonl(clnt->cl_prog);    /* program number */
1479         *p++ = htonl(clnt->cl_vers);    /* program version */
1480         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1481         p = rpcauth_marshcred(task, p);
1482         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1483         return p;
1484 }
1485
1486 static __be32 *
1487 rpc_verify_header(struct rpc_task *task)
1488 {
1489         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1490         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1491         __be32  *p = iov->iov_base;
1492         u32 n;
1493         int error = -EACCES;
1494
1495         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1496                 /* RFC-1014 says that the representation of XDR data must be a
1497                  * multiple of four bytes
1498                  * - if it isn't pointer subtraction in the NFS client may give
1499                  *   undefined results
1500                  */
1501                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1502                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1503                        task->tk_rqstp->rq_rcv_buf.len);
1504                 goto out_eio;
1505         }
1506         if ((len -= 3) < 0)
1507                 goto out_overflow;
1508
1509         p += 1; /* skip XID */
1510         if ((n = ntohl(*p++)) != RPC_REPLY) {
1511                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1512                         task->tk_pid, __func__, n);
1513                 goto out_garbage;
1514         }
1515
1516         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1517                 if (--len < 0)
1518                         goto out_overflow;
1519                 switch ((n = ntohl(*p++))) {
1520                         case RPC_AUTH_ERROR:
1521                                 break;
1522                         case RPC_MISMATCH:
1523                                 dprintk("RPC: %5u %s: RPC call version "
1524                                                 "mismatch!\n",
1525                                                 task->tk_pid, __func__);
1526                                 error = -EPROTONOSUPPORT;
1527                                 goto out_err;
1528                         default:
1529                                 dprintk("RPC: %5u %s: RPC call rejected, "
1530                                                 "unknown error: %x\n",
1531                                                 task->tk_pid, __func__, n);
1532                                 goto out_eio;
1533                 }
1534                 if (--len < 0)
1535                         goto out_overflow;
1536                 switch ((n = ntohl(*p++))) {
1537                 case RPC_AUTH_REJECTEDCRED:
1538                 case RPC_AUTH_REJECTEDVERF:
1539                 case RPCSEC_GSS_CREDPROBLEM:
1540                 case RPCSEC_GSS_CTXPROBLEM:
1541                         if (!task->tk_cred_retry)
1542                                 break;
1543                         task->tk_cred_retry--;
1544                         dprintk("RPC: %5u %s: retry stale creds\n",
1545                                         task->tk_pid, __func__);
1546                         rpcauth_invalcred(task);
1547                         /* Ensure we obtain a new XID! */
1548                         xprt_release(task);
1549                         task->tk_action = call_refresh;
1550                         goto out_retry;
1551                 case RPC_AUTH_BADCRED:
1552                 case RPC_AUTH_BADVERF:
1553                         /* possibly garbled cred/verf? */
1554                         if (!task->tk_garb_retry)
1555                                 break;
1556                         task->tk_garb_retry--;
1557                         dprintk("RPC: %5u %s: retry garbled creds\n",
1558                                         task->tk_pid, __func__);
1559                         task->tk_action = call_bind;
1560                         goto out_retry;
1561                 case RPC_AUTH_TOOWEAK:
1562                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1563                                "authentication.\n", task->tk_client->cl_server);
1564                         break;
1565                 default:
1566                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1567                                         task->tk_pid, __func__, n);
1568                         error = -EIO;
1569                 }
1570                 dprintk("RPC: %5u %s: call rejected %d\n",
1571                                 task->tk_pid, __func__, n);
1572                 goto out_err;
1573         }
1574         if (!(p = rpcauth_checkverf(task, p))) {
1575                 dprintk("RPC: %5u %s: auth check failed\n",
1576                                 task->tk_pid, __func__);
1577                 goto out_garbage;               /* bad verifier, retry */
1578         }
1579         len = p - (__be32 *)iov->iov_base - 1;
1580         if (len < 0)
1581                 goto out_overflow;
1582         switch ((n = ntohl(*p++))) {
1583         case RPC_SUCCESS:
1584                 return p;
1585         case RPC_PROG_UNAVAIL:
1586                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1587                                 task->tk_pid, __func__,
1588                                 (unsigned int)task->tk_client->cl_prog,
1589                                 task->tk_client->cl_server);
1590                 error = -EPFNOSUPPORT;
1591                 goto out_err;
1592         case RPC_PROG_MISMATCH:
1593                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1594                                 "server %s\n", task->tk_pid, __func__,
1595                                 (unsigned int)task->tk_client->cl_prog,
1596                                 (unsigned int)task->tk_client->cl_vers,
1597                                 task->tk_client->cl_server);
1598                 error = -EPROTONOSUPPORT;
1599                 goto out_err;
1600         case RPC_PROC_UNAVAIL:
1601                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1602                                 "version %u on server %s\n",
1603                                 task->tk_pid, __func__,
1604                                 rpc_proc_name(task),
1605                                 task->tk_client->cl_prog,
1606                                 task->tk_client->cl_vers,
1607                                 task->tk_client->cl_server);
1608                 error = -EOPNOTSUPP;
1609                 goto out_err;
1610         case RPC_GARBAGE_ARGS:
1611                 dprintk("RPC: %5u %s: server saw garbage\n",
1612                                 task->tk_pid, __func__);
1613                 break;                  /* retry */
1614         default:
1615                 dprintk("RPC: %5u %s: server accept status: %x\n",
1616                                 task->tk_pid, __func__, n);
1617                 /* Also retry */
1618         }
1619
1620 out_garbage:
1621         task->tk_client->cl_stats->rpcgarbage++;
1622         if (task->tk_garb_retry) {
1623                 task->tk_garb_retry--;
1624                 dprintk("RPC: %5u %s: retrying\n",
1625                                 task->tk_pid, __func__);
1626                 task->tk_action = call_bind;
1627 out_retry:
1628                 return ERR_PTR(-EAGAIN);
1629         }
1630 out_eio:
1631         error = -EIO;
1632 out_err:
1633         rpc_exit(task, error);
1634         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1635                         __func__, error);
1636         return ERR_PTR(error);
1637 out_overflow:
1638         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1639                         __func__);
1640         goto out_garbage;
1641 }
1642
1643 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1644 {
1645         return 0;
1646 }
1647
1648 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1649 {
1650         return 0;
1651 }
1652
1653 static struct rpc_procinfo rpcproc_null = {
1654         .p_encode = rpcproc_encode_null,
1655         .p_decode = rpcproc_decode_null,
1656 };
1657
1658 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1659 {
1660         struct rpc_message msg = {
1661                 .rpc_proc = &rpcproc_null,
1662         };
1663         int err;
1664         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1665         err = rpc_call_sync(clnt, &msg, flags);
1666         put_rpccred(msg.rpc_cred);
1667         return err;
1668 }
1669
1670 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1671 {
1672         struct rpc_message msg = {
1673                 .rpc_proc = &rpcproc_null,
1674                 .rpc_cred = cred,
1675         };
1676         struct rpc_task_setup task_setup_data = {
1677                 .rpc_client = clnt,
1678                 .rpc_message = &msg,
1679                 .callback_ops = &rpc_default_ops,
1680                 .flags = flags,
1681         };
1682         return rpc_run_task(&task_setup_data);
1683 }
1684 EXPORT_SYMBOL_GPL(rpc_call_null);
1685
1686 #ifdef RPC_DEBUG
1687 static void rpc_show_header(void)
1688 {
1689         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1690                 "-timeout ---ops--\n");
1691 }
1692
1693 static void rpc_show_task(const struct rpc_clnt *clnt,
1694                           const struct rpc_task *task)
1695 {
1696         const char *rpc_waitq = "none";
1697         char *p, action[KSYM_SYMBOL_LEN];
1698
1699         if (RPC_IS_QUEUED(task))
1700                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1701
1702         /* map tk_action pointer to a function name; then trim off
1703          * the "+0x0 [sunrpc]" */
1704         sprint_symbol(action, (unsigned long)task->tk_action);
1705         p = strchr(action, '+');
1706         if (p)
1707                 *p = '\0';
1708
1709         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1710                 task->tk_pid, task->tk_flags, task->tk_status,
1711                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1712                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1713                 action, rpc_waitq);
1714 }
1715
1716 void rpc_show_tasks(void)
1717 {
1718         struct rpc_clnt *clnt;
1719         struct rpc_task *task;
1720         int header = 0;
1721
1722         spin_lock(&rpc_client_lock);
1723         list_for_each_entry(clnt, &all_clients, cl_clients) {
1724                 spin_lock(&clnt->cl_lock);
1725                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1726                         if (!header) {
1727                                 rpc_show_header();
1728                                 header++;
1729                         }
1730                         rpc_show_task(clnt, task);
1731                 }
1732                 spin_unlock(&clnt->cl_lock);
1733         }
1734         spin_unlock(&rpc_client_lock);
1735 }
1736 #endif