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/namei.h>
  31 #include <linux/mount.h>
  32 #include <linux/slab.h>
  33 #include <linux/utsname.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/in6.h>
  36
  37 #include <linux/sunrpc/clnt.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41
  42 #include "sunrpc.h"
  43
  44 #ifdef RPC_DEBUG
  45 # define RPCDBG_FACILITY        RPCDBG_CALL
  46 #endif
  47
  48 #define dprint_status(t)                                        \
  49         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  50                         __func__, t->tk_status)
  51
  52 /*
  53  * All RPC clients are linked into this list
  54  */
  55 static LIST_HEAD(all_clients);
  56 static DEFINE_SPINLOCK(rpc_client_lock);
  57
  58 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  59
  60
  61 static void     call_start(struct rpc_task *task);
  62 static void     call_reserve(struct rpc_task *task);
  63 static void     call_reserveresult(struct rpc_task *task);
  64 static void     call_allocate(struct rpc_task *task);
  65 static void     call_decode(struct rpc_task *task);
  66 static void     call_bind(struct rpc_task *task);
  67 static void     call_bind_status(struct rpc_task *task);
  68 static void     call_transmit(struct rpc_task *task);
  69 #if defined(CONFIG_NFS_V4_1)
  70 static void     call_bc_transmit(struct rpc_task *task);
  71 #endif /* CONFIG_NFS_V4_1 */
  72 static void     call_status(struct rpc_task *task);
  73 static void     call_transmit_status(struct rpc_task *task);
  74 static void     call_refresh(struct rpc_task *task);
  75 static void     call_refreshresult(struct rpc_task *task);
  76 static void     call_timeout(struct rpc_task *task);
  77 static void     call_connect(struct rpc_task *task);
  78 static void     call_connect_status(struct rpc_task *task);
  79
  80 static __be32   *rpc_encode_header(struct rpc_task *task);
  81 static __be32   *rpc_verify_header(struct rpc_task *task);
  82 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  83
  84 static void rpc_register_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_add(&clnt->cl_clients, &all_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static void rpc_unregister_client(struct rpc_clnt *clnt)
  92 {
  93         spin_lock(&rpc_client_lock);
  94         list_del(&clnt->cl_clients);
  95         spin_unlock(&rpc_client_lock);
  96 }
  97
  98 static int
  99 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
 100 {
 101         static uint32_t clntid;
 102         struct nameidata nd;
 103         struct path path;
 104         char name[15];
 105         struct qstr q = {
 106                 .name = name,
 107         };
 108         int error;
 109
 110         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
 111         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
 112         if (dir_name == NULL)
 113                 return 0;
 114
 115         path.mnt = rpc_get_mount();
 116         if (IS_ERR(path.mnt))
 117                 return PTR_ERR(path.mnt);
 118         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
 119         if (error)
 120                 goto err;
 121
 122         for (;;) {
 123                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 124                 name[sizeof(name) - 1] = '\0';
 125                 q.hash = full_name_hash(q.name, q.len);
 126                 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
 127                 if (!IS_ERR(path.dentry))
 128                         break;
 129                 error = PTR_ERR(path.dentry);
 130                 if (error != -EEXIST) {
 131                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 132                                         " %s/%s, error %d\n",
 133                                         dir_name, name, error);
 134                         goto err_path_put;
 135                 }
 136         }
 137         path_put(&nd.path);
 138         clnt->cl_path = path;
 139         return 0;
 140 err_path_put:
 141         path_put(&nd.path);
 142 err:
 143         rpc_put_mount();
 144         return error;
 145 }
 146
 147 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 148 {
 149         struct rpc_program      *program = args->program;
 150         struct rpc_version      *version;
 151         struct rpc_clnt         *clnt = NULL;
 152         struct rpc_auth         *auth;
 153         int err;
 154         size_t len;
 155
 156         /* sanity check the name before trying to print it */
 157         err = -EINVAL;
 158         len = strlen(args->servername);
 159         if (len > RPC_MAXNETNAMELEN)
 160                 goto out_no_rpciod;
 161         len++;
 162
 163         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 164                         program->name, args->servername, xprt);
 165
 166         err = rpciod_up();
 167         if (err)
 168                 goto out_no_rpciod;
 169         err = -EINVAL;
 170         if (!xprt)
 171                 goto out_no_xprt;
 172
 173         if (args->version >= program->nrvers)
 174                 goto out_err;
 175         version = program->version[args->version];
 176         if (version == NULL)
 177                 goto out_err;
 178
 179         err = -ENOMEM;
 180         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 181         if (!clnt)
 182                 goto out_err;
 183         clnt->cl_parent = clnt;
 184
 185         clnt->cl_server = clnt->cl_inline_name;
 186         if (len > sizeof(clnt->cl_inline_name)) {
 187                 char *buf = kmalloc(len, GFP_KERNEL);
 188                 if (buf != NULL)
 189                         clnt->cl_server = buf;
 190                 else
 191                         len = sizeof(clnt->cl_inline_name);
 192         }
 193         strlcpy(clnt->cl_server, args->servername, len);
 194
 195         clnt->cl_xprt     = xprt;
 196         clnt->cl_procinfo = version->procs;
 197         clnt->cl_maxproc  = version->nrprocs;
 198         clnt->cl_protname = program->name;
 199         clnt->cl_prog     = args->prognumber ? : program->number;
 200         clnt->cl_vers     = version->number;
 201         clnt->cl_stats    = program->stats;
 202         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 203         err = -ENOMEM;
 204         if (clnt->cl_metrics == NULL)
 205                 goto out_no_stats;
 206         clnt->cl_program  = program;
 207         INIT_LIST_HEAD(&clnt->cl_tasks);
 208         spin_lock_init(&clnt->cl_lock);
 209
 210         if (!xprt_bound(clnt->cl_xprt))
 211                 clnt->cl_autobind = 1;
 212
 213         clnt->cl_timeout = xprt->timeout;
 214         if (args->timeout != NULL) {
 215                 memcpy(&clnt->cl_timeout_default, args->timeout,
 216                                 sizeof(clnt->cl_timeout_default));
 217                 clnt->cl_timeout = &clnt->cl_timeout_default;
 218         }
 219
 220         clnt->cl_rtt = &clnt->cl_rtt_default;
 221         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 222         clnt->cl_principal = NULL;
 223         if (args->client_name) {
 224                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 225                 if (!clnt->cl_principal)
 226                         goto out_no_principal;
 227         }
 228
 229         kref_init(&clnt->cl_kref);
 230
 231         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 232         if (err < 0)
 233                 goto out_no_path;
 234
 235         auth = rpcauth_create(args->authflavor, clnt);
 236         if (IS_ERR(auth)) {
 237                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 238                                 args->authflavor);
 239                 err = PTR_ERR(auth);
 240                 goto out_no_auth;
 241         }
 242
 243         /* save the nodename */
 244         clnt->cl_nodelen = strlen(init_utsname()->nodename);
 245         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 246                 clnt->cl_nodelen = UNX_MAXNODENAME;
 247         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
 248         rpc_register_client(clnt);
 249         return clnt;
 250
 251 out_no_auth:
 252         if (!IS_ERR(clnt->cl_path.dentry)) {
 253                 rpc_remove_client_dir(clnt->cl_path.dentry);
 254                 rpc_put_mount();
 255         }
 256 out_no_path:
 257         kfree(clnt->cl_principal);
 258 out_no_principal:
 259         rpc_free_iostats(clnt->cl_metrics);
 260 out_no_stats:
 261         if (clnt->cl_server != clnt->cl_inline_name)
 262                 kfree(clnt->cl_server);
 263         kfree(clnt);
 264 out_err:
 265         xprt_put(xprt);
 266 out_no_xprt:
 267         rpciod_down();
 268 out_no_rpciod:
 269         return ERR_PTR(err);
 270 }
 271
 272 /*
 273  * rpc_create - create an RPC client and transport with one call
 274  * @args: rpc_clnt create argument structure
 275  *
 276  * Creates and initializes an RPC transport and an RPC client.
 277  *
 278  * It can ping the server in order to determine if it is up, and to see if
 279  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 280  * this behavior so asynchronous tasks can also use rpc_create.
 281  */
 282 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 283 {
 284         struct rpc_xprt *xprt;
 285         struct rpc_clnt *clnt;
 286         struct xprt_create xprtargs = {
 287                 .ident = args->protocol,
 288                 .srcaddr = args->saddress,
 289                 .dstaddr = args->address,
 290                 .addrlen = args->addrsize,
 291                 .bc_xprt = args->bc_xprt,
 292         };
 293         char servername[48];
 294
 295         /*
 296          * If the caller chooses not to specify a hostname, whip
 297          * up a string representation of the passed-in address.
 298          */
 299         if (args->servername == NULL) {
 300                 servername[0] = '\0';
 301                 switch (args->address->sa_family) {
 302                 case AF_INET: {
 303                         struct sockaddr_in *sin =
 304                                         (struct sockaddr_in *)args->address;
 305                         snprintf(servername, sizeof(servername), "%pI4",
 306                                  &sin->sin_addr.s_addr);
 307                         break;
 308                 }
 309                 case AF_INET6: {
 310                         struct sockaddr_in6 *sin =
 311                                         (struct sockaddr_in6 *)args->address;
 312                         snprintf(servername, sizeof(servername), "%pI6",
 313                                  &sin->sin6_addr);
 314                         break;
 315                 }
 316                 default:
 317                         /* caller wants default server name, but
 318                          * address family isn't recognized. */
 319                         return ERR_PTR(-EINVAL);
 320                 }
 321                 args->servername = servername;
 322         }
 323
 324         xprt = xprt_create_transport(&xprtargs);
 325         if (IS_ERR(xprt))
 326                 return (struct rpc_clnt *)xprt;
 327
 328         /*
 329          * By default, kernel RPC client connects from a reserved port.
 330          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 331          * but it is always enabled for rpciod, which handles the connect
 332          * operation.
 333          */
 334         xprt->resvport = 1;
 335         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 336                 xprt->resvport = 0;
 337
 338         clnt = rpc_new_client(args, xprt);
 339         if (IS_ERR(clnt))
 340                 return clnt;
 341
 342         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 343                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 344                 if (err != 0) {
 345                         rpc_shutdown_client(clnt);
 346                         return ERR_PTR(err);
 347                 }
 348         }
 349
 350         clnt->cl_softrtry = 1;
 351         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 352                 clnt->cl_softrtry = 0;
 353
 354         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 355                 clnt->cl_autobind = 1;
 356         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 357                 clnt->cl_discrtry = 1;
 358         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 359                 clnt->cl_chatty = 1;
 360
 361         return clnt;
 362 }
 363 EXPORT_SYMBOL_GPL(rpc_create);
 364
 365 /*
 366  * This function clones the RPC client structure. It allows us to share the
 367  * same transport while varying parameters such as the authentication
 368  * flavour.
 369  */
 370 struct rpc_clnt *
 371 rpc_clone_client(struct rpc_clnt *clnt)
 372 {
 373         struct rpc_clnt *new;
 374         int err = -ENOMEM;
 375
 376         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 377         if (!new)
 378                 goto out_no_clnt;
 379         new->cl_parent = clnt;
 380         /* Turn off autobind on clones */
 381         new->cl_autobind = 0;
 382         INIT_LIST_HEAD(&new->cl_tasks);
 383         spin_lock_init(&new->cl_lock);
 384         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 385         new->cl_metrics = rpc_alloc_iostats(clnt);
 386         if (new->cl_metrics == NULL)
 387                 goto out_no_stats;
 388         if (clnt->cl_principal) {
 389                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 390                 if (new->cl_principal == NULL)
 391                         goto out_no_principal;
 392         }
 393         kref_init(&new->cl_kref);
 394         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 395         if (err != 0)
 396                 goto out_no_path;
 397         if (new->cl_auth)
 398                 atomic_inc(&new->cl_auth->au_count);
 399         xprt_get(clnt->cl_xprt);
 400         kref_get(&clnt->cl_kref);
 401         rpc_register_client(new);
 402         rpciod_up();
 403         return new;
 404 out_no_path:
 405         kfree(new->cl_principal);
 406 out_no_principal:
 407         rpc_free_iostats(new->cl_metrics);
 408 out_no_stats:
 409         kfree(new);
 410 out_no_clnt:
 411         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 412         return ERR_PTR(err);
 413 }
 414 EXPORT_SYMBOL_GPL(rpc_clone_client);
 415
 416 /*
 417  * Properly shut down an RPC client, terminating all outstanding
 418  * requests.
 419  */
 420 void rpc_shutdown_client(struct rpc_clnt *clnt)
 421 {
 422         dprintk("RPC:       shutting down %s client for %s\n",
 423                         clnt->cl_protname, clnt->cl_server);
 424
 425         while (!list_empty(&clnt->cl_tasks)) {
 426                 rpc_killall_tasks(clnt);
 427                 wait_event_timeout(destroy_wait,
 428                         list_empty(&clnt->cl_tasks), 1*HZ);
 429         }
 430
 431         rpc_release_client(clnt);
 432 }
 433 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 434
 435 /*
 436  * Free an RPC client
 437  */
 438 static void
 439 rpc_free_client(struct kref *kref)
 440 {
 441         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 442
 443         dprintk("RPC:       destroying %s client for %s\n",
 444                         clnt->cl_protname, clnt->cl_server);
 445         if (!IS_ERR(clnt->cl_path.dentry)) {
 446                 rpc_remove_client_dir(clnt->cl_path.dentry);
 447                 rpc_put_mount();
 448         }
 449         if (clnt->cl_parent != clnt) {
 450                 rpc_release_client(clnt->cl_parent);
 451                 goto out_free;
 452         }
 453         if (clnt->cl_server != clnt->cl_inline_name)
 454                 kfree(clnt->cl_server);
 455 out_free:
 456         rpc_unregister_client(clnt);
 457         rpc_free_iostats(clnt->cl_metrics);
 458         kfree(clnt->cl_principal);
 459         clnt->cl_metrics = NULL;
 460         xprt_put(clnt->cl_xprt);
 461         rpciod_down();
 462         kfree(clnt);
 463 }
 464
 465 /*
 466  * Free an RPC client
 467  */
 468 static void
 469 rpc_free_auth(struct kref *kref)
 470 {
 471         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 472
 473         if (clnt->cl_auth == NULL) {
 474                 rpc_free_client(kref);
 475                 return;
 476         }
 477
 478         /*
 479          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 480          *       release remaining GSS contexts. This mechanism ensures
 481          *       that it can do so safely.
 482          */
 483         kref_init(kref);
 484         rpcauth_release(clnt->cl_auth);
 485         clnt->cl_auth = NULL;
 486         kref_put(kref, rpc_free_client);
 487 }
 488
 489 /*
 490  * Release reference to the RPC client
 491  */
 492 void
 493 rpc_release_client(struct rpc_clnt *clnt)
 494 {
 495         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 496
 497         if (list_empty(&clnt->cl_tasks))
 498                 wake_up(&destroy_wait);
 499         kref_put(&clnt->cl_kref, rpc_free_auth);
 500 }
 501
 502 /**
 503  * rpc_bind_new_program - bind a new RPC program to an existing client
 504  * @old: old rpc_client
 505  * @program: rpc program to set
 506  * @vers: rpc program version
 507  *
 508  * Clones the rpc client and sets up a new RPC program. This is mainly
 509  * of use for enabling different RPC programs to share the same transport.
 510  * The Sun NFSv2/v3 ACL protocol can do this.
 511  */
 512 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 513                                       struct rpc_program *program,
 514                                       u32 vers)
 515 {
 516         struct rpc_clnt *clnt;
 517         struct rpc_version *version;
 518         int err;
 519
 520         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 521         version = program->version[vers];
 522         clnt = rpc_clone_client(old);
 523         if (IS_ERR(clnt))
 524                 goto out;
 525         clnt->cl_procinfo = version->procs;
 526         clnt->cl_maxproc  = version->nrprocs;
 527         clnt->cl_protname = program->name;
 528         clnt->cl_prog     = program->number;
 529         clnt->cl_vers     = version->number;
 530         clnt->cl_stats    = program->stats;
 531         err = rpc_ping(clnt, RPC_TASK_SOFT);
 532         if (err != 0) {
 533                 rpc_shutdown_client(clnt);
 534                 clnt = ERR_PTR(err);
 535         }
 536 out:
 537         return clnt;
 538 }
 539 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 540
 541 /*
 542  * Default callback for async RPC calls
 543  */
 544 static void
 545 rpc_default_callback(struct rpc_task *task, void *data)
 546 {
 547 }
 548
 549 static const struct rpc_call_ops rpc_default_ops = {
 550         .rpc_call_done = rpc_default_callback,
 551 };
 552
 553 /**
 554  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 555  * @task_setup_data: pointer to task initialisation data
 556  */
 557 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 558 {
 559         struct rpc_task *task, *ret;
 560
 561         task = rpc_new_task(task_setup_data);
 562         if (task == NULL) {
 563                 rpc_release_calldata(task_setup_data->callback_ops,
 564                                 task_setup_data->callback_data);
 565                 ret = ERR_PTR(-ENOMEM);
 566                 goto out;
 567         }
 568
 569         if (task->tk_status != 0) {
 570                 ret = ERR_PTR(task->tk_status);
 571                 rpc_put_task(task);
 572                 goto out;
 573         }
 574         atomic_inc(&task->tk_count);
 575         rpc_execute(task);
 576         ret = task;
 577 out:
 578         return ret;
 579 }
 580 EXPORT_SYMBOL_GPL(rpc_run_task);
 581
 582 /**
 583  * rpc_call_sync - Perform a synchronous RPC call
 584  * @clnt: pointer to RPC client
 585  * @msg: RPC call parameters
 586  * @flags: RPC call flags
 587  */
 588 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 589 {
 590         struct rpc_task *task;
 591         struct rpc_task_setup task_setup_data = {
 592                 .rpc_client = clnt,
 593                 .rpc_message = msg,
 594                 .callback_ops = &rpc_default_ops,
 595                 .flags = flags,
 596         };
 597         int status;
 598
 599         BUG_ON(flags & RPC_TASK_ASYNC);
 600
 601         task = rpc_run_task(&task_setup_data);
 602         if (IS_ERR(task))
 603                 return PTR_ERR(task);
 604         status = task->tk_status;
 605         rpc_put_task(task);
 606         return status;
 607 }
 608 EXPORT_SYMBOL_GPL(rpc_call_sync);
 609
 610 /**
 611  * rpc_call_async - Perform an asynchronous RPC call
 612  * @clnt: pointer to RPC client
 613  * @msg: RPC call parameters
 614  * @flags: RPC call flags
 615  * @tk_ops: RPC call ops
 616  * @data: user call data
 617  */
 618 int
 619 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 620                const struct rpc_call_ops *tk_ops, void *data)
 621 {
 622         struct rpc_task *task;
 623         struct rpc_task_setup task_setup_data = {
 624                 .rpc_client = clnt,
 625                 .rpc_message = msg,
 626                 .callback_ops = tk_ops,
 627                 .callback_data = data,
 628                 .flags = flags|RPC_TASK_ASYNC,
 629         };
 630
 631         task = rpc_run_task(&task_setup_data);
 632         if (IS_ERR(task))
 633                 return PTR_ERR(task);
 634         rpc_put_task(task);
 635         return 0;
 636 }
 637 EXPORT_SYMBOL_GPL(rpc_call_async);
 638
 639 #if defined(CONFIG_NFS_V4_1)
 640 /**
 641  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 642  * rpc_execute against it
 643  * @ops: RPC call ops
 644  */
 645 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 646                                         const struct rpc_call_ops *tk_ops)
 647 {
 648         struct rpc_task *task;
 649         struct xdr_buf *xbufp = &req->rq_snd_buf;
 650         struct rpc_task_setup task_setup_data = {
 651                 .callback_ops = tk_ops,
 652         };
 653
 654         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 655         /*
 656          * Create an rpc_task to send the data
 657          */
 658         task = rpc_new_task(&task_setup_data);
 659         if (!task) {
 660                 xprt_free_bc_request(req);
 661                 goto out;
 662         }
 663         task->tk_rqstp = req;
 664
 665         /*
 666          * Set up the xdr_buf length.
 667          * This also indicates that the buffer is XDR encoded already.
 668          */
 669         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 670                         xbufp->tail[0].iov_len;
 671
 672         task->tk_action = call_bc_transmit;
 673         atomic_inc(&task->tk_count);
 674         BUG_ON(atomic_read(&task->tk_count) != 2);
 675         rpc_execute(task);
 676
 677 out:
 678         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 679         return task;
 680 }
 681 #endif /* CONFIG_NFS_V4_1 */
 682
 683 void
 684 rpc_call_start(struct rpc_task *task)
 685 {
 686         task->tk_action = call_start;
 687 }
 688 EXPORT_SYMBOL_GPL(rpc_call_start);
 689
 690 /**
 691  * rpc_peeraddr - extract remote peer address from clnt's xprt
 692  * @clnt: RPC client structure
 693  * @buf: target buffer
 694  * @bufsize: length of target buffer
 695  *
 696  * Returns the number of bytes that are actually in the stored address.
 697  */
 698 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 699 {
 700         size_t bytes;
 701         struct rpc_xprt *xprt = clnt->cl_xprt;
 702
 703         bytes = sizeof(xprt->addr);
 704         if (bytes > bufsize)
 705                 bytes = bufsize;
 706         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 707         return xprt->addrlen;
 708 }
 709 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 710
 711 /**
 712  * rpc_peeraddr2str - return remote peer address in printable format
 713  * @clnt: RPC client structure
 714  * @format: address format
 715  *
 716  */
 717 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 718                              enum rpc_display_format_t format)
 719 {
 720         struct rpc_xprt *xprt = clnt->cl_xprt;
 721
 722         if (xprt->address_strings[format] != NULL)
 723                 return xprt->address_strings[format];
 724         else
 725                 return "unprintable";
 726 }
 727 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 728
 729 void
 730 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 731 {
 732         struct rpc_xprt *xprt = clnt->cl_xprt;
 733         if (xprt->ops->set_buffer_size)
 734                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 735 }
 736 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 737
 738 /*
 739  * Return size of largest payload RPC client can support, in bytes
 740  *
 741  * For stream transports, this is one RPC record fragment (see RFC
 742  * 1831), as we don't support multi-record requests yet.  For datagram
 743  * transports, this is the size of an IP packet minus the IP, UDP, and
 744  * RPC header sizes.
 745  */
 746 size_t rpc_max_payload(struct rpc_clnt *clnt)
 747 {
 748         return clnt->cl_xprt->max_payload;
 749 }
 750 EXPORT_SYMBOL_GPL(rpc_max_payload);
 751
 752 /**
 753  * rpc_force_rebind - force transport to check that remote port is unchanged
 754  * @clnt: client to rebind
 755  *
 756  */
 757 void rpc_force_rebind(struct rpc_clnt *clnt)
 758 {
 759         if (clnt->cl_autobind)
 760                 xprt_clear_bound(clnt->cl_xprt);
 761 }
 762 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 763
 764 /*
 765  * Restart an (async) RPC call from the call_prepare state.
 766  * Usually called from within the exit handler.
 767  */
 768 void
 769 rpc_restart_call_prepare(struct rpc_task *task)
 770 {
 771         if (RPC_ASSASSINATED(task))
 772                 return;
 773         task->tk_action = rpc_prepare_task;
 774 }
 775 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 776
 777 /*
 778  * Restart an (async) RPC call. Usually called from within the
 779  * exit handler.
 780  */
 781 void
 782 rpc_restart_call(struct rpc_task *task)
 783 {
 784         if (RPC_ASSASSINATED(task))
 785                 return;
 786
 787         task->tk_action = call_start;
 788 }
 789 EXPORT_SYMBOL_GPL(rpc_restart_call);
 790
 791 #ifdef RPC_DEBUG
 792 static const char *rpc_proc_name(const struct rpc_task *task)
 793 {
 794         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 795
 796         if (proc) {
 797                 if (proc->p_name)
 798                         return proc->p_name;
 799                 else
 800                         return "NULL";
 801         } else
 802                 return "no proc";
 803 }
 804 #endif
 805
 806 /*
 807  * 0.  Initial state
 808  *
 809  *     Other FSM states can be visited zero or more times, but
 810  *     this state is visited exactly once for each RPC.
 811  */
 812 static void
 813 call_start(struct rpc_task *task)
 814 {
 815         struct rpc_clnt *clnt = task->tk_client;
 816
 817         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 818                         clnt->cl_protname, clnt->cl_vers,
 819                         rpc_proc_name(task),
 820                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 821
 822         /* Increment call count */
 823         task->tk_msg.rpc_proc->p_count++;
 824         clnt->cl_stats->rpccnt++;
 825         task->tk_action = call_reserve;
 826 }
 827
 828 /*
 829  * 1.   Reserve an RPC call slot
 830  */
 831 static void
 832 call_reserve(struct rpc_task *task)
 833 {
 834         dprint_status(task);
 835
 836         if (!rpcauth_uptodatecred(task)) {
 837                 task->tk_action = call_refresh;
 838                 return;
 839         }
 840
 841         task->tk_status  = 0;
 842         task->tk_action  = call_reserveresult;
 843         xprt_reserve(task);
 844 }
 845
 846 /*
 847  * 1b.  Grok the result of xprt_reserve()
 848  */
 849 static void
 850 call_reserveresult(struct rpc_task *task)
 851 {
 852         int status = task->tk_status;
 853
 854         dprint_status(task);
 855
 856         /*
 857          * After a call to xprt_reserve(), we must have either
 858          * a request slot or else an error status.
 859          */
 860         task->tk_status = 0;
 861         if (status >= 0) {
 862                 if (task->tk_rqstp) {
 863                         task->tk_action = call_allocate;
 864                         return;
 865                 }
 866
 867                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 868                                 __func__, status);
 869                 rpc_exit(task, -EIO);
 870                 return;
 871         }
 872
 873         /*
 874          * Even though there was an error, we may have acquired
 875          * a request slot somehow.  Make sure not to leak it.
 876          */
 877         if (task->tk_rqstp) {
 878                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 879                                 __func__, status);
 880                 xprt_release(task);
 881         }
 882
 883         switch (status) {
 884         case -EAGAIN:   /* woken up; retry */
 885                 task->tk_action = call_reserve;
 886                 return;
 887         case -EIO:      /* probably a shutdown */
 888                 break;
 889         default:
 890                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 891                                 __func__, status);
 892                 break;
 893         }
 894         rpc_exit(task, status);
 895 }
 896
 897 /*
 898  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 899  *      (Note: buffer memory is freed in xprt_release).
 900  */
 901 static void
 902 call_allocate(struct rpc_task *task)
 903 {
 904         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 905         struct rpc_rqst *req = task->tk_rqstp;
 906         struct rpc_xprt *xprt = task->tk_xprt;
 907         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 908
 909         dprint_status(task);
 910
 911         task->tk_status = 0;
 912         task->tk_action = call_bind;
 913
 914         if (req->rq_buffer)
 915                 return;
 916
 917         if (proc->p_proc != 0) {
 918                 BUG_ON(proc->p_arglen == 0);
 919                 if (proc->p_decode != NULL)
 920                         BUG_ON(proc->p_replen == 0);
 921         }
 922
 923         /*
 924          * Calculate the size (in quads) of the RPC call
 925          * and reply headers, and convert both values
 926          * to byte sizes.
 927          */
 928         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 929         req->rq_callsize <<= 2;
 930         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 931         req->rq_rcvsize <<= 2;
 932
 933         req->rq_buffer = xprt->ops->buf_alloc(task,
 934                                         req->rq_callsize + req->rq_rcvsize);
 935         if (req->rq_buffer != NULL)
 936                 return;
 937
 938         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 939
 940         if (RPC_IS_ASYNC(task) || !signalled()) {
 941                 task->tk_action = call_allocate;
 942                 rpc_delay(task, HZ>>4);
 943                 return;
 944         }
 945
 946         rpc_exit(task, -ERESTARTSYS);
 947 }
 948
 949 static inline int
 950 rpc_task_need_encode(struct rpc_task *task)
 951 {
 952         return task->tk_rqstp->rq_snd_buf.len == 0;
 953 }
 954
 955 static inline void
 956 rpc_task_force_reencode(struct rpc_task *task)
 957 {
 958         task->tk_rqstp->rq_snd_buf.len = 0;
 959         task->tk_rqstp->rq_bytes_sent = 0;
 960 }
 961
 962 static inline void
 963 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 964 {
 965         buf->head[0].iov_base = start;
 966         buf->head[0].iov_len = len;
 967         buf->tail[0].iov_len = 0;
 968         buf->page_len = 0;
 969         buf->flags = 0;
 970         buf->len = 0;
 971         buf->buflen = len;
 972 }
 973
 974 /*
 975  * 3.   Encode arguments of an RPC call
 976  */
 977 static void
 978 rpc_xdr_encode(struct rpc_task *task)
 979 {
 980         struct rpc_rqst *req = task->tk_rqstp;
 981         kxdrproc_t      encode;
 982         __be32          *p;
 983
 984         dprint_status(task);
 985
 986         rpc_xdr_buf_init(&req->rq_snd_buf,
 987                          req->rq_buffer,
 988                          req->rq_callsize);
 989         rpc_xdr_buf_init(&req->rq_rcv_buf,
 990                          (char *)req->rq_buffer + req->rq_callsize,
 991                          req->rq_rcvsize);
 992
 993         p = rpc_encode_header(task);
 994         if (p == NULL) {
 995                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 996                 rpc_exit(task, -EIO);
 997                 return;
 998         }
 999
1000         encode = task->tk_msg.rpc_proc->p_encode;
1001         if (encode == NULL)
1002                 return;
1003
1004         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1005                         task->tk_msg.rpc_argp);
1006 }
1007
1008 /*
1009  * 4.   Get the server port number if not yet set
1010  */
1011 static void
1012 call_bind(struct rpc_task *task)
1013 {
1014         struct rpc_xprt *xprt = task->tk_xprt;
1015
1016         dprint_status(task);
1017
1018         task->tk_action = call_connect;
1019         if (!xprt_bound(xprt)) {
1020                 task->tk_action = call_bind_status;
1021                 task->tk_timeout = xprt->bind_timeout;
1022                 xprt->ops->rpcbind(task);
1023         }
1024 }
1025
1026 /*
1027  * 4a.  Sort out bind result
1028  */
1029 static void
1030 call_bind_status(struct rpc_task *task)
1031 {
1032         int status = -EIO;
1033
1034         if (task->tk_status >= 0) {
1035                 dprint_status(task);
1036                 task->tk_status = 0;
1037                 task->tk_action = call_connect;
1038                 return;
1039         }
1040
1041         switch (task->tk_status) {
1042         case -ENOMEM:
1043                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1044                 rpc_delay(task, HZ >> 2);
1045                 goto retry_timeout;
1046         case -EACCES:
1047                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1048                                 "unavailable\n", task->tk_pid);
1049                 /* fail immediately if this is an RPC ping */
1050                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1051                         status = -EOPNOTSUPP;
1052                         break;
1053                 }
1054                 rpc_delay(task, 3*HZ);
1055                 goto retry_timeout;
1056         case -ETIMEDOUT:
1057                 dprintk("RPC: %5u rpcbind request timed out\n",
1058                                 task->tk_pid);
1059                 goto retry_timeout;
1060         case -EPFNOSUPPORT:
1061                 /* server doesn't support any rpcbind version we know of */
1062                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1063                                 task->tk_pid);
1064                 break;
1065         case -EPROTONOSUPPORT:
1066                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1067                                 task->tk_pid);
1068                 task->tk_status = 0;
1069                 task->tk_action = call_bind;
1070                 return;
1071         default:
1072                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1073                                 task->tk_pid, -task->tk_status);
1074         }
1075
1076         rpc_exit(task, status);
1077         return;
1078
1079 retry_timeout:
1080         task->tk_action = call_timeout;
1081 }
1082
1083 /*
1084  * 4b.  Connect to the RPC server
1085  */
1086 static void
1087 call_connect(struct rpc_task *task)
1088 {
1089         struct rpc_xprt *xprt = task->tk_xprt;
1090
1091         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1092                         task->tk_pid, xprt,
1093                         (xprt_connected(xprt) ? "is" : "is not"));
1094
1095         task->tk_action = call_transmit;
1096         if (!xprt_connected(xprt)) {
1097                 task->tk_action = call_connect_status;
1098                 if (task->tk_status < 0)
1099                         return;
1100                 xprt_connect(task);
1101         }
1102 }
1103
1104 /*
1105  * 4c.  Sort out connect result
1106  */
1107 static void
1108 call_connect_status(struct rpc_task *task)
1109 {
1110         struct rpc_clnt *clnt = task->tk_client;
1111         int status = task->tk_status;
1112
1113         dprint_status(task);
1114
1115         task->tk_status = 0;
1116         if (status >= 0 || status == -EAGAIN) {
1117                 clnt->cl_stats->netreconn++;
1118                 task->tk_action = call_transmit;
1119                 return;
1120         }
1121
1122         switch (status) {
1123                 /* if soft mounted, test if we've timed out */
1124         case -ETIMEDOUT:
1125                 task->tk_action = call_timeout;
1126                 break;
1127         default:
1128                 rpc_exit(task, -EIO);
1129         }
1130 }
1131
1132 /*
1133  * 5.   Transmit the RPC request, and wait for reply
1134  */
1135 static void
1136 call_transmit(struct rpc_task *task)
1137 {
1138         dprint_status(task);
1139
1140         task->tk_action = call_status;
1141         if (task->tk_status < 0)
1142                 return;
1143         task->tk_status = xprt_prepare_transmit(task);
1144         if (task->tk_status != 0)
1145                 return;
1146         task->tk_action = call_transmit_status;
1147         /* Encode here so that rpcsec_gss can use correct sequence number. */
1148         if (rpc_task_need_encode(task)) {
1149                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1150                 rpc_xdr_encode(task);
1151                 /* Did the encode result in an error condition? */
1152                 if (task->tk_status != 0) {
1153                         /* Was the error nonfatal? */
1154                         if (task->tk_status == -EAGAIN)
1155                                 rpc_delay(task, HZ >> 4);
1156                         else
1157                                 rpc_exit(task, task->tk_status);
1158                         return;
1159                 }
1160         }
1161         xprt_transmit(task);
1162         if (task->tk_status < 0)
1163                 return;
1164         /*
1165          * On success, ensure that we call xprt_end_transmit() before sleeping
1166          * in order to allow access to the socket to other RPC requests.
1167          */
1168         call_transmit_status(task);
1169         if (rpc_reply_expected(task))
1170                 return;
1171         task->tk_action = rpc_exit_task;
1172         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1173 }
1174
1175 /*
1176  * 5a.  Handle cleanup after a transmission
1177  */
1178 static void
1179 call_transmit_status(struct rpc_task *task)
1180 {
1181         task->tk_action = call_status;
1182         switch (task->tk_status) {
1183         case -EAGAIN:
1184                 break;
1185         default:
1186                 xprt_end_transmit(task);
1187                 /*
1188                  * Special cases: if we've been waiting on the
1189                  * socket's write_space() callback, or if the
1190                  * socket just returned a connection error,
1191                  * then hold onto the transport lock.
1192                  */
1193         case -ECONNREFUSED:
1194         case -ECONNRESET:
1195         case -ENOTCONN:
1196         case -EHOSTDOWN:
1197         case -EHOSTUNREACH:
1198         case -ENETUNREACH:
1199         case -EPIPE:
1200                 rpc_task_force_reencode(task);
1201         }
1202 }
1203
1204 #if defined(CONFIG_NFS_V4_1)
1205 /*
1206  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1207  * addition, disconnect on connectivity errors.
1208  */
1209 static void
1210 call_bc_transmit(struct rpc_task *task)
1211 {
1212         struct rpc_rqst *req = task->tk_rqstp;
1213
1214         BUG_ON(task->tk_status != 0);
1215         task->tk_status = xprt_prepare_transmit(task);
1216         if (task->tk_status == -EAGAIN) {
1217                 /*
1218                  * Could not reserve the transport. Try again after the
1219                  * transport is released.
1220                  */
1221                 task->tk_status = 0;
1222                 task->tk_action = call_bc_transmit;
1223                 return;
1224         }
1225
1226         task->tk_action = rpc_exit_task;
1227         if (task->tk_status < 0) {
1228                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1229                         "error: %d\n", task->tk_status);
1230                 return;
1231         }
1232
1233         xprt_transmit(task);
1234         xprt_end_transmit(task);
1235         dprint_status(task);
1236         switch (task->tk_status) {
1237         case 0:
1238                 /* Success */
1239                 break;
1240         case -EHOSTDOWN:
1241         case -EHOSTUNREACH:
1242         case -ENETUNREACH:
1243         case -ETIMEDOUT:
1244                 /*
1245                  * Problem reaching the server.  Disconnect and let the
1246                  * forechannel reestablish the connection.  The server will
1247                  * have to retransmit the backchannel request and we'll
1248                  * reprocess it.  Since these ops are idempotent, there's no
1249                  * need to cache our reply at this time.
1250                  */
1251                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1252                         "error: %d\n", task->tk_status);
1253                 xprt_conditional_disconnect(task->tk_xprt,
1254                         req->rq_connect_cookie);
1255                 break;
1256         default:
1257                 /*
1258                  * We were unable to reply and will have to drop the
1259                  * request.  The server should reconnect and retransmit.
1260                  */
1261                 BUG_ON(task->tk_status == -EAGAIN);
1262                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1263                         "error: %d\n", task->tk_status);
1264                 break;
1265         }
1266         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1267 }
1268 #endif /* CONFIG_NFS_V4_1 */
1269
1270 /*
1271  * 6.   Sort out the RPC call status
1272  */
1273 static void
1274 call_status(struct rpc_task *task)
1275 {
1276         struct rpc_clnt *clnt = task->tk_client;
1277         struct rpc_rqst *req = task->tk_rqstp;
1278         int             status;
1279
1280         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1281                 task->tk_status = req->rq_reply_bytes_recvd;
1282
1283         dprint_status(task);
1284
1285         status = task->tk_status;
1286         if (status >= 0) {
1287                 task->tk_action = call_decode;
1288                 return;
1289         }
1290
1291         task->tk_status = 0;
1292         switch(status) {
1293         case -EHOSTDOWN:
1294         case -EHOSTUNREACH:
1295         case -ENETUNREACH:
1296                 /*
1297                  * Delay any retries for 3 seconds, then handle as if it
1298                  * were a timeout.
1299                  */
1300                 rpc_delay(task, 3*HZ);
1301         case -ETIMEDOUT:
1302                 task->tk_action = call_timeout;
1303                 if (task->tk_client->cl_discrtry)
1304                         xprt_conditional_disconnect(task->tk_xprt,
1305                                         req->rq_connect_cookie);
1306                 break;
1307         case -ECONNRESET:
1308         case -ECONNREFUSED:
1309                 rpc_force_rebind(clnt);
1310                 rpc_delay(task, 3*HZ);
1311         case -EPIPE:
1312         case -ENOTCONN:
1313                 task->tk_action = call_bind;
1314                 break;
1315         case -EAGAIN:
1316                 task->tk_action = call_transmit;
1317                 break;
1318         case -EIO:
1319                 /* shutdown or soft timeout */
1320                 rpc_exit(task, status);
1321                 break;
1322         default:
1323                 if (clnt->cl_chatty)
1324                         printk("%s: RPC call returned error %d\n",
1325                                clnt->cl_protname, -status);
1326                 rpc_exit(task, status);
1327         }
1328 }
1329
1330 /*
1331  * 6a.  Handle RPC timeout
1332  *      We do not release the request slot, so we keep using the
1333  *      same XID for all retransmits.
1334  */
1335 static void
1336 call_timeout(struct rpc_task *task)
1337 {
1338         struct rpc_clnt *clnt = task->tk_client;
1339
1340         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1341                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1342                 goto retry;
1343         }
1344
1345         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1346         task->tk_timeouts++;
1347
1348         if (RPC_IS_SOFT(task)) {
1349                 if (clnt->cl_chatty)
1350                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1351                                 clnt->cl_protname, clnt->cl_server);
1352                 rpc_exit(task, -EIO);
1353                 return;
1354         }
1355
1356         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1357                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1358                 if (clnt->cl_chatty)
1359                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1360                         clnt->cl_protname, clnt->cl_server);
1361         }
1362         rpc_force_rebind(clnt);
1363         /*
1364          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1365          * event? RFC2203 requires the server to drop all such requests.
1366          */
1367         rpcauth_invalcred(task);
1368
1369 retry:
1370         clnt->cl_stats->rpcretrans++;
1371         task->tk_action = call_bind;
1372         task->tk_status = 0;
1373 }
1374
1375 /*
1376  * 7.   Decode the RPC reply
1377  */
1378 static void
1379 call_decode(struct rpc_task *task)
1380 {
1381         struct rpc_clnt *clnt = task->tk_client;
1382         struct rpc_rqst *req = task->tk_rqstp;
1383         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1384         __be32          *p;
1385
1386         dprintk("RPC: %5u call_decode (status %d)\n",
1387                         task->tk_pid, task->tk_status);
1388
1389         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1390                 if (clnt->cl_chatty)
1391                         printk(KERN_NOTICE "%s: server %s OK\n",
1392                                 clnt->cl_protname, clnt->cl_server);
1393                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1394         }
1395
1396         /*
1397          * Ensure that we see all writes made by xprt_complete_rqst()
1398          * before it changed req->rq_reply_bytes_recvd.
1399          */
1400         smp_rmb();
1401         req->rq_rcv_buf.len = req->rq_private_buf.len;
1402
1403         /* Check that the softirq receive buffer is valid */
1404         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1405                                 sizeof(req->rq_rcv_buf)) != 0);
1406
1407         if (req->rq_rcv_buf.len < 12) {
1408                 if (!RPC_IS_SOFT(task)) {
1409                         task->tk_action = call_bind;
1410                         clnt->cl_stats->rpcretrans++;
1411                         goto out_retry;
1412                 }
1413                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1414                                 clnt->cl_protname, task->tk_status);
1415                 task->tk_action = call_timeout;
1416                 goto out_retry;
1417         }
1418
1419         p = rpc_verify_header(task);
1420         if (IS_ERR(p)) {
1421                 if (p == ERR_PTR(-EAGAIN))
1422                         goto out_retry;
1423                 return;
1424         }
1425
1426         task->tk_action = rpc_exit_task;
1427
1428         if (decode) {
1429                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1430                                                       task->tk_msg.rpc_resp);
1431         }
1432         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1433                         task->tk_status);
1434         return;
1435 out_retry:
1436         task->tk_status = 0;
1437         /* Note: rpc_verify_header() may have freed the RPC slot */
1438         if (task->tk_rqstp == req) {
1439                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1440                 if (task->tk_client->cl_discrtry)
1441                         xprt_conditional_disconnect(task->tk_xprt,
1442                                         req->rq_connect_cookie);
1443         }
1444 }
1445
1446 /*
1447  * 8.   Refresh the credentials if rejected by the server
1448  */
1449 static void
1450 call_refresh(struct rpc_task *task)
1451 {
1452         dprint_status(task);
1453
1454         task->tk_action = call_refreshresult;
1455         task->tk_status = 0;
1456         task->tk_client->cl_stats->rpcauthrefresh++;
1457         rpcauth_refreshcred(task);
1458 }
1459
1460 /*
1461  * 8a.  Process the results of a credential refresh
1462  */
1463 static void
1464 call_refreshresult(struct rpc_task *task)
1465 {
1466         int status = task->tk_status;
1467
1468         dprint_status(task);
1469
1470         task->tk_status = 0;
1471         task->tk_action = call_reserve;
1472         if (status >= 0 && rpcauth_uptodatecred(task))
1473                 return;
1474         if (status == -EACCES) {
1475                 rpc_exit(task, -EACCES);
1476                 return;
1477         }
1478         task->tk_action = call_refresh;
1479         if (status != -ETIMEDOUT)
1480                 rpc_delay(task, 3*HZ);
1481         return;
1482 }
1483
1484 static __be32 *
1485 rpc_encode_header(struct rpc_task *task)
1486 {
1487         struct rpc_clnt *clnt = task->tk_client;
1488         struct rpc_rqst *req = task->tk_rqstp;
1489         __be32          *p = req->rq_svec[0].iov_base;
1490
1491         /* FIXME: check buffer size? */
1492
1493         p = xprt_skip_transport_header(task->tk_xprt, p);
1494         *p++ = req->rq_xid;             /* XID */
1495         *p++ = htonl(RPC_CALL);         /* CALL */
1496         *p++ = htonl(RPC_VERSION);      /* RPC version */
1497         *p++ = htonl(clnt->cl_prog);    /* program number */
1498         *p++ = htonl(clnt->cl_vers);    /* program version */
1499         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1500         p = rpcauth_marshcred(task, p);
1501         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1502         return p;
1503 }
1504
1505 static __be32 *
1506 rpc_verify_header(struct rpc_task *task)
1507 {
1508         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1509         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1510         __be32  *p = iov->iov_base;
1511         u32 n;
1512         int error = -EACCES;
1513
1514         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1515                 /* RFC-1014 says that the representation of XDR data must be a
1516                  * multiple of four bytes
1517                  * - if it isn't pointer subtraction in the NFS client may give
1518                  *   undefined results
1519                  */
1520                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1521                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1522                        task->tk_rqstp->rq_rcv_buf.len);
1523                 goto out_eio;
1524         }
1525         if ((len -= 3) < 0)
1526                 goto out_overflow;
1527
1528         p += 1; /* skip XID */
1529         if ((n = ntohl(*p++)) != RPC_REPLY) {
1530                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1531                         task->tk_pid, __func__, n);
1532                 goto out_garbage;
1533         }
1534
1535         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1536                 if (--len < 0)
1537                         goto out_overflow;
1538                 switch ((n = ntohl(*p++))) {
1539                         case RPC_AUTH_ERROR:
1540                                 break;
1541                         case RPC_MISMATCH:
1542                                 dprintk("RPC: %5u %s: RPC call version "
1543                                                 "mismatch!\n",
1544                                                 task->tk_pid, __func__);
1545                                 error = -EPROTONOSUPPORT;
1546                                 goto out_err;
1547                         default:
1548                                 dprintk("RPC: %5u %s: RPC call rejected, "
1549                                                 "unknown error: %x\n",
1550                                                 task->tk_pid, __func__, n);
1551                                 goto out_eio;
1552                 }
1553                 if (--len < 0)
1554                         goto out_overflow;
1555                 switch ((n = ntohl(*p++))) {
1556                 case RPC_AUTH_REJECTEDCRED:
1557                 case RPC_AUTH_REJECTEDVERF:
1558                 case RPCSEC_GSS_CREDPROBLEM:
1559                 case RPCSEC_GSS_CTXPROBLEM:
1560                         if (!task->tk_cred_retry)
1561                                 break;
1562                         task->tk_cred_retry--;
1563                         dprintk("RPC: %5u %s: retry stale creds\n",
1564                                         task->tk_pid, __func__);
1565                         rpcauth_invalcred(task);
1566                         /* Ensure we obtain a new XID! */
1567                         xprt_release(task);
1568                         task->tk_action = call_refresh;
1569                         goto out_retry;
1570                 case RPC_AUTH_BADCRED:
1571                 case RPC_AUTH_BADVERF:
1572                         /* possibly garbled cred/verf? */
1573                         if (!task->tk_garb_retry)
1574                                 break;
1575                         task->tk_garb_retry--;
1576                         dprintk("RPC: %5u %s: retry garbled creds\n",
1577                                         task->tk_pid, __func__);
1578                         task->tk_action = call_bind;
1579                         goto out_retry;
1580                 case RPC_AUTH_TOOWEAK:
1581                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1582                                "authentication.\n", task->tk_client->cl_server);
1583                         break;
1584                 default:
1585                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1586                                         task->tk_pid, __func__, n);
1587                         error = -EIO;
1588                 }
1589                 dprintk("RPC: %5u %s: call rejected %d\n",
1590                                 task->tk_pid, __func__, n);
1591                 goto out_err;
1592         }
1593         if (!(p = rpcauth_checkverf(task, p))) {
1594                 dprintk("RPC: %5u %s: auth check failed\n",
1595                                 task->tk_pid, __func__);
1596                 goto out_garbage;               /* bad verifier, retry */
1597         }
1598         len = p - (__be32 *)iov->iov_base - 1;
1599         if (len < 0)
1600                 goto out_overflow;
1601         switch ((n = ntohl(*p++))) {
1602         case RPC_SUCCESS:
1603                 return p;
1604         case RPC_PROG_UNAVAIL:
1605                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1606                                 task->tk_pid, __func__,
1607                                 (unsigned int)task->tk_client->cl_prog,
1608                                 task->tk_client->cl_server);
1609                 error = -EPFNOSUPPORT;
1610                 goto out_err;
1611         case RPC_PROG_MISMATCH:
1612                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1613                                 "server %s\n", task->tk_pid, __func__,
1614                                 (unsigned int)task->tk_client->cl_prog,
1615                                 (unsigned int)task->tk_client->cl_vers,
1616                                 task->tk_client->cl_server);
1617                 error = -EPROTONOSUPPORT;
1618                 goto out_err;
1619         case RPC_PROC_UNAVAIL:
1620                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1621                                 "version %u on server %s\n",
1622                                 task->tk_pid, __func__,
1623                                 rpc_proc_name(task),
1624                                 task->tk_client->cl_prog,
1625                                 task->tk_client->cl_vers,
1626                                 task->tk_client->cl_server);
1627                 error = -EOPNOTSUPP;
1628                 goto out_err;
1629         case RPC_GARBAGE_ARGS:
1630                 dprintk("RPC: %5u %s: server saw garbage\n",
1631                                 task->tk_pid, __func__);
1632                 break;                  /* retry */
1633         default:
1634                 dprintk("RPC: %5u %s: server accept status: %x\n",
1635                                 task->tk_pid, __func__, n);
1636                 /* Also retry */
1637         }
1638
1639 out_garbage:
1640         task->tk_client->cl_stats->rpcgarbage++;
1641         if (task->tk_garb_retry) {
1642                 task->tk_garb_retry--;
1643                 dprintk("RPC: %5u %s: retrying\n",
1644                                 task->tk_pid, __func__);
1645                 task->tk_action = call_bind;
1646 out_retry:
1647                 return ERR_PTR(-EAGAIN);
1648         }
1649 out_eio:
1650         error = -EIO;
1651 out_err:
1652         rpc_exit(task, error);
1653         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1654                         __func__, error);
1655         return ERR_PTR(error);
1656 out_overflow:
1657         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1658                         __func__);
1659         goto out_garbage;
1660 }
1661
1662 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1663 {
1664         return 0;
1665 }
1666
1667 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1668 {
1669         return 0;
1670 }
1671
1672 static struct rpc_procinfo rpcproc_null = {
1673         .p_encode = rpcproc_encode_null,
1674         .p_decode = rpcproc_decode_null,
1675 };
1676
1677 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1678 {
1679         struct rpc_message msg = {
1680                 .rpc_proc = &rpcproc_null,
1681         };
1682         int err;
1683         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1684         err = rpc_call_sync(clnt, &msg, flags);
1685         put_rpccred(msg.rpc_cred);
1686         return err;
1687 }
1688
1689 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1690 {
1691         struct rpc_message msg = {
1692                 .rpc_proc = &rpcproc_null,
1693                 .rpc_cred = cred,
1694         };
1695         struct rpc_task_setup task_setup_data = {
1696                 .rpc_client = clnt,
1697                 .rpc_message = &msg,
1698                 .callback_ops = &rpc_default_ops,
1699                 .flags = flags,
1700         };
1701         return rpc_run_task(&task_setup_data);
1702 }
1703 EXPORT_SYMBOL_GPL(rpc_call_null);
1704
1705 #ifdef RPC_DEBUG
1706 static void rpc_show_header(void)
1707 {
1708         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1709                 "-timeout ---ops--\n");
1710 }
1711
1712 static void rpc_show_task(const struct rpc_clnt *clnt,
1713                           const struct rpc_task *task)
1714 {
1715         const char *rpc_waitq = "none";
1716         char *p, action[KSYM_SYMBOL_LEN];
1717
1718         if (RPC_IS_QUEUED(task))
1719                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1720
1721         /* map tk_action pointer to a function name; then trim off
1722          * the "+0x0 [sunrpc]" */
1723         sprint_symbol(action, (unsigned long)task->tk_action);
1724         p = strchr(action, '+');
1725         if (p)
1726                 *p = '\0';
1727
1728         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1729                 task->tk_pid, task->tk_flags, task->tk_status,
1730                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1731                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1732                 action, rpc_waitq);
1733 }
1734
1735 void rpc_show_tasks(void)
1736 {
1737         struct rpc_clnt *clnt;
1738         struct rpc_task *task;
1739         int header = 0;
1740
1741         spin_lock(&rpc_client_lock);
1742         list_for_each_entry(clnt, &all_clients, cl_clients) {
1743                 spin_lock(&clnt->cl_lock);
1744                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1745                         if (!header) {
1746                                 rpc_show_header();
1747                                 header++;
1748                         }
1749                         rpc_show_task(clnt, task);
1750                 }
1751                 spin_unlock(&clnt->cl_lock);
1752         }
1753         spin_unlock(&rpc_client_lock);
1754 }
1755 #endif