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  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/utsname.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/in.h>
  31 #include <linux/in6.h>
  32 #include <linux/un.h>
  33 #include <linux/rcupdate.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38 #include <linux/sunrpc/bc_xprt.h>
  39 #include <trace/events/sunrpc.h>
  40
  41 #include "sunrpc.h"
  42 #include "netns.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
  56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  57
  58
  59 static void     call_start(struct rpc_task *task);
  60 static void     call_reserve(struct rpc_task *task);
  61 static void     call_reserveresult(struct rpc_task *task);
  62 static void     call_allocate(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  68 static void     call_bc_transmit(struct rpc_task *task);
  69 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_timeout(struct rpc_task *task);
  75 static void     call_connect(struct rpc_task *task);
  76 static void     call_connect_status(struct rpc_task *task);
  77
  78 static __be32   *rpc_encode_header(struct rpc_task *task);
  79 static __be32   *rpc_verify_header(struct rpc_task *task);
  80 static int      rpc_ping(struct rpc_clnt *clnt);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         if (clnt->cl_dentry) {
 105                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 106                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 107                 rpc_remove_client_dir(clnt->cl_dentry);
 108         }
 109         clnt->cl_dentry = NULL;
 110 }
 111
 112 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 113 {
 114         struct net *net = rpc_net_ns(clnt);
 115         struct super_block *pipefs_sb;
 116
 117         pipefs_sb = rpc_get_sb_net(net);
 118         if (pipefs_sb) {
 119                 __rpc_clnt_remove_pipedir(clnt);
 120                 rpc_put_sb_net(net);
 121         }
 122 }
 123
 124 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 125                                     struct rpc_clnt *clnt,
 126                                     const char *dir_name)
 127 {
 128         static uint32_t clntid;
 129         char name[15];
 130         struct qstr q = { .name = name };
 131         struct dentry *dir, *dentry;
 132         int error;
 133
 134         dir = rpc_d_lookup_sb(sb, dir_name);
 135         if (dir == NULL) {
 136                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 137                 return dir;
 138         }
 139         for (;;) {
 140                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 141                 name[sizeof(name) - 1] = '\0';
 142                 q.hash = full_name_hash(q.name, q.len);
 143                 dentry = rpc_create_client_dir(dir, &q, clnt);
 144                 if (!IS_ERR(dentry))
 145                         break;
 146                 error = PTR_ERR(dentry);
 147                 if (error != -EEXIST) {
 148                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 149                                         " %s/%s, error %d\n",
 150                                         dir_name, name, error);
 151                         break;
 152                 }
 153         }
 154         dput(dir);
 155         return dentry;
 156 }
 157
 158 static int
 159 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 160 {
 161         struct net *net = rpc_net_ns(clnt);
 162         struct super_block *pipefs_sb;
 163         struct dentry *dentry;
 164
 165         clnt->cl_dentry = NULL;
 166         if (dir_name == NULL)
 167                 return 0;
 168         pipefs_sb = rpc_get_sb_net(net);
 169         if (!pipefs_sb)
 170                 return 0;
 171         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 172         rpc_put_sb_net(net);
 173         if (IS_ERR(dentry))
 174                 return PTR_ERR(dentry);
 175         clnt->cl_dentry = dentry;
 176         return 0;
 177 }
 178
 179 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 180 {
 181         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 182             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 183                 return 1;
 184         return 0;
 185 }
 186
 187 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 188                                    struct super_block *sb)
 189 {
 190         struct dentry *dentry;
 191         int err = 0;
 192
 193         switch (event) {
 194         case RPC_PIPEFS_MOUNT:
 195                 dentry = rpc_setup_pipedir_sb(sb, clnt,
 196                                               clnt->cl_program->pipe_dir_name);
 197                 if (!dentry)
 198                         return -ENOENT;
 199                 if (IS_ERR(dentry))
 200                         return PTR_ERR(dentry);
 201                 clnt->cl_dentry = dentry;
 202                 if (clnt->cl_auth->au_ops->pipes_create) {
 203                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 204                         if (err)
 205                                 __rpc_clnt_remove_pipedir(clnt);
 206                 }
 207                 break;
 208         case RPC_PIPEFS_UMOUNT:
 209                 __rpc_clnt_remove_pipedir(clnt);
 210                 break;
 211         default:
 212                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 213                 return -ENOTSUPP;
 214         }
 215         return err;
 216 }
 217
 218 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 219                                 struct super_block *sb)
 220 {
 221         int error = 0;
 222
 223         for (;; clnt = clnt->cl_parent) {
 224                 if (!rpc_clnt_skip_event(clnt, event))
 225                         error = __rpc_clnt_handle_event(clnt, event, sb);
 226                 if (error || clnt == clnt->cl_parent)
 227                         break;
 228         }
 229         return error;
 230 }
 231
 232 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 233 {
 234         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 235         struct rpc_clnt *clnt;
 236
 237         spin_lock(&sn->rpc_client_lock);
 238         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 239                 if (clnt->cl_program->pipe_dir_name == NULL)
 240                         continue;
 241                 if (rpc_clnt_skip_event(clnt, event))
 242                         continue;
 243                 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 244                         continue;
 245                 spin_unlock(&sn->rpc_client_lock);
 246                 return clnt;
 247         }
 248         spin_unlock(&sn->rpc_client_lock);
 249         return NULL;
 250 }
 251
 252 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 253                             void *ptr)
 254 {
 255         struct super_block *sb = ptr;
 256         struct rpc_clnt *clnt;
 257         int error = 0;
 258
 259         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 260                 error = __rpc_pipefs_event(clnt, event, sb);
 261                 rpc_release_client(clnt);
 262                 if (error)
 263                         break;
 264         }
 265         return error;
 266 }
 267
 268 static struct notifier_block rpc_clients_block = {
 269         .notifier_call  = rpc_pipefs_event,
 270         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 271 };
 272
 273 int rpc_clients_notifier_register(void)
 274 {
 275         return rpc_pipefs_notifier_register(&rpc_clients_block);
 276 }
 277
 278 void rpc_clients_notifier_unregister(void)
 279 {
 280         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 281 }
 282
 283 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 284 {
 285         clnt->cl_nodelen = strlen(nodename);
 286         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 287                 clnt->cl_nodelen = UNX_MAXNODENAME;
 288         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 289 }
 290
 291 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 292 {
 293         const struct rpc_program *program = args->program;
 294         const struct rpc_version *version;
 295         struct rpc_clnt         *clnt = NULL;
 296         struct rpc_auth         *auth;
 297         int err;
 298
 299         /* sanity check the name before trying to print it */
 300         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 301                         program->name, args->servername, xprt);
 302
 303         err = rpciod_up();
 304         if (err)
 305                 goto out_no_rpciod;
 306         err = -EINVAL;
 307         if (!xprt)
 308                 goto out_no_xprt;
 309
 310         if (args->version >= program->nrvers)
 311                 goto out_err;
 312         version = program->version[args->version];
 313         if (version == NULL)
 314                 goto out_err;
 315
 316         err = -ENOMEM;
 317         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 318         if (!clnt)
 319                 goto out_err;
 320         clnt->cl_parent = clnt;
 321
 322         rcu_assign_pointer(clnt->cl_xprt, xprt);
 323         clnt->cl_procinfo = version->procs;
 324         clnt->cl_maxproc  = version->nrprocs;
 325         clnt->cl_protname = program->name;
 326         clnt->cl_prog     = args->prognumber ? : program->number;
 327         clnt->cl_vers     = version->number;
 328         clnt->cl_stats    = program->stats;
 329         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 330         err = -ENOMEM;
 331         if (clnt->cl_metrics == NULL)
 332                 goto out_no_stats;
 333         clnt->cl_program  = program;
 334         INIT_LIST_HEAD(&clnt->cl_tasks);
 335         spin_lock_init(&clnt->cl_lock);
 336
 337         if (!xprt_bound(xprt))
 338                 clnt->cl_autobind = 1;
 339
 340         clnt->cl_timeout = xprt->timeout;
 341         if (args->timeout != NULL) {
 342                 memcpy(&clnt->cl_timeout_default, args->timeout,
 343                                 sizeof(clnt->cl_timeout_default));
 344                 clnt->cl_timeout = &clnt->cl_timeout_default;
 345         }
 346
 347         clnt->cl_rtt = &clnt->cl_rtt_default;
 348         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 349         clnt->cl_principal = NULL;
 350         if (args->client_name) {
 351                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 352                 if (!clnt->cl_principal)
 353                         goto out_no_principal;
 354         }
 355
 356         atomic_set(&clnt->cl_count, 1);
 357
 358         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 359         if (err < 0)
 360                 goto out_no_path;
 361
 362         auth = rpcauth_create(args->authflavor, clnt);
 363         if (IS_ERR(auth)) {
 364                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 365                                 args->authflavor);
 366                 err = PTR_ERR(auth);
 367                 goto out_no_auth;
 368         }
 369
 370         /* save the nodename */
 371         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 372         rpc_register_client(clnt);
 373         return clnt;
 374
 375 out_no_auth:
 376         rpc_clnt_remove_pipedir(clnt);
 377 out_no_path:
 378         kfree(clnt->cl_principal);
 379 out_no_principal:
 380         rpc_free_iostats(clnt->cl_metrics);
 381 out_no_stats:
 382         kfree(clnt);
 383 out_err:
 384         xprt_put(xprt);
 385 out_no_xprt:
 386         rpciod_down();
 387 out_no_rpciod:
 388         return ERR_PTR(err);
 389 }
 390
 391 /**
 392  * rpc_create - create an RPC client and transport with one call
 393  * @args: rpc_clnt create argument structure
 394  *
 395  * Creates and initializes an RPC transport and an RPC client.
 396  *
 397  * It can ping the server in order to determine if it is up, and to see if
 398  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 399  * this behavior so asynchronous tasks can also use rpc_create.
 400  */
 401 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 402 {
 403         struct rpc_xprt *xprt;
 404         struct rpc_clnt *clnt;
 405         struct xprt_create xprtargs = {
 406                 .net = args->net,
 407                 .ident = args->protocol,
 408                 .srcaddr = args->saddress,
 409                 .dstaddr = args->address,
 410                 .addrlen = args->addrsize,
 411                 .servername = args->servername,
 412                 .bc_xprt = args->bc_xprt,
 413         };
 414         char servername[48];
 415
 416         /*
 417          * If the caller chooses not to specify a hostname, whip
 418          * up a string representation of the passed-in address.
 419          */
 420         if (xprtargs.servername == NULL) {
 421                 struct sockaddr_un *sun =
 422                                 (struct sockaddr_un *)args->address;
 423                 struct sockaddr_in *sin =
 424                                 (struct sockaddr_in *)args->address;
 425                 struct sockaddr_in6 *sin6 =
 426                                 (struct sockaddr_in6 *)args->address;
 427
 428                 servername[0] = '\0';
 429                 switch (args->address->sa_family) {
 430                 case AF_LOCAL:
 431                         snprintf(servername, sizeof(servername), "%s",
 432                                  sun->sun_path);
 433                         break;
 434                 case AF_INET:
 435                         snprintf(servername, sizeof(servername), "%pI4",
 436                                  &sin->sin_addr.s_addr);
 437                         break;
 438                 case AF_INET6:
 439                         snprintf(servername, sizeof(servername), "%pI6",
 440                                  &sin6->sin6_addr);
 441                         break;
 442                 default:
 443                         /* caller wants default server name, but
 444                          * address family isn't recognized. */
 445                         return ERR_PTR(-EINVAL);
 446                 }
 447                 xprtargs.servername = servername;
 448         }
 449
 450         xprt = xprt_create_transport(&xprtargs);
 451         if (IS_ERR(xprt))
 452                 return (struct rpc_clnt *)xprt;
 453
 454         /*
 455          * By default, kernel RPC client connects from a reserved port.
 456          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 457          * but it is always enabled for rpciod, which handles the connect
 458          * operation.
 459          */
 460         xprt->resvport = 1;
 461         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 462                 xprt->resvport = 0;
 463
 464         clnt = rpc_new_client(args, xprt);
 465         if (IS_ERR(clnt))
 466                 return clnt;
 467
 468         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 469                 int err = rpc_ping(clnt);
 470                 if (err != 0) {
 471                         rpc_shutdown_client(clnt);
 472                         return ERR_PTR(err);
 473                 }
 474         }
 475
 476         clnt->cl_softrtry = 1;
 477         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 478                 clnt->cl_softrtry = 0;
 479
 480         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 481                 clnt->cl_autobind = 1;
 482         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 483                 clnt->cl_discrtry = 1;
 484         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 485                 clnt->cl_chatty = 1;
 486
 487         return clnt;
 488 }
 489 EXPORT_SYMBOL_GPL(rpc_create);
 490
 491 /*
 492  * This function clones the RPC client structure. It allows us to share the
 493  * same transport while varying parameters such as the authentication
 494  * flavour.
 495  */
 496 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 497                                            struct rpc_clnt *clnt)
 498 {
 499         struct rpc_xprt *xprt;
 500         struct rpc_clnt *new;
 501         int err;
 502
 503         err = -ENOMEM;
 504         rcu_read_lock();
 505         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 506         rcu_read_unlock();
 507         if (xprt == NULL)
 508                 goto out_err;
 509         args->servername = xprt->servername;
 510
 511         new = rpc_new_client(args, xprt);
 512         if (IS_ERR(new)) {
 513                 err = PTR_ERR(new);
 514                 goto out_put;
 515         }
 516
 517         atomic_inc(&clnt->cl_count);
 518         new->cl_parent = clnt;
 519
 520         /* Turn off autobind on clones */
 521         new->cl_autobind = 0;
 522         new->cl_softrtry = clnt->cl_softrtry;
 523         new->cl_discrtry = clnt->cl_discrtry;
 524         new->cl_chatty = clnt->cl_chatty;
 525         return new;
 526
 527 out_put:
 528         xprt_put(xprt);
 529 out_err:
 530         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 531         return ERR_PTR(err);
 532 }
 533
 534 /**
 535  * rpc_clone_client - Clone an RPC client structure
 536  *
 537  * @clnt: RPC client whose parameters are copied
 538  *
 539  * Returns a fresh RPC client or an ERR_PTR.
 540  */
 541 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 542 {
 543         struct rpc_create_args args = {
 544                 .program        = clnt->cl_program,
 545                 .prognumber     = clnt->cl_prog,
 546                 .version        = clnt->cl_vers,
 547                 .authflavor     = clnt->cl_auth->au_flavor,
 548                 .client_name    = clnt->cl_principal,
 549         };
 550         return __rpc_clone_client(&args, clnt);
 551 }
 552 EXPORT_SYMBOL_GPL(rpc_clone_client);
 553
 554 /**
 555  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 556  *
 557  * @clnt: RPC client whose parameters are copied
 558  * @auth: security flavor for new client
 559  *
 560  * Returns a fresh RPC client or an ERR_PTR.
 561  */
 562 struct rpc_clnt *
 563 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 564 {
 565         struct rpc_create_args args = {
 566                 .program        = clnt->cl_program,
 567                 .prognumber     = clnt->cl_prog,
 568                 .version        = clnt->cl_vers,
 569                 .authflavor     = flavor,
 570                 .client_name    = clnt->cl_principal,
 571         };
 572         return __rpc_clone_client(&args, clnt);
 573 }
 574 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 575
 576 /*
 577  * Kill all tasks for the given client.
 578  * XXX: kill their descendants as well?
 579  */
 580 void rpc_killall_tasks(struct rpc_clnt *clnt)
 581 {
 582         struct rpc_task *rovr;
 583
 584
 585         if (list_empty(&clnt->cl_tasks))
 586                 return;
 587         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 588         /*
 589          * Spin lock all_tasks to prevent changes...
 590          */
 591         spin_lock(&clnt->cl_lock);
 592         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 593                 if (!RPC_IS_ACTIVATED(rovr))
 594                         continue;
 595                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 596                         rovr->tk_flags |= RPC_TASK_KILLED;
 597                         rpc_exit(rovr, -EIO);
 598                         if (RPC_IS_QUEUED(rovr))
 599                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 600                                                         rovr);
 601                 }
 602         }
 603         spin_unlock(&clnt->cl_lock);
 604 }
 605 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 606
 607 /*
 608  * Properly shut down an RPC client, terminating all outstanding
 609  * requests.
 610  */
 611 void rpc_shutdown_client(struct rpc_clnt *clnt)
 612 {
 613         /*
 614          * To avoid deadlock, never call rpc_shutdown_client from a
 615          * workqueue context!
 616          */
 617         WARN_ON_ONCE(current->flags & PF_WQ_WORKER);
 618         might_sleep();
 619
 620         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 621                         clnt->cl_protname,
 622                         rcu_dereference(clnt->cl_xprt)->servername);
 623
 624         while (!list_empty(&clnt->cl_tasks)) {
 625                 rpc_killall_tasks(clnt);
 626                 wait_event_timeout(destroy_wait,
 627                         list_empty(&clnt->cl_tasks), 1*HZ);
 628         }
 629
 630         rpc_release_client(clnt);
 631 }
 632 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 633
 634 /*
 635  * Free an RPC client
 636  */
 637 static void
 638 rpc_free_client(struct rpc_clnt *clnt)
 639 {
 640         dprintk_rcu("RPC:       destroying %s client for %s\n",
 641                         clnt->cl_protname,
 642                         rcu_dereference(clnt->cl_xprt)->servername);
 643         if (clnt->cl_parent != clnt)
 644                 rpc_release_client(clnt->cl_parent);
 645         rpc_unregister_client(clnt);
 646         rpc_clnt_remove_pipedir(clnt);
 647         rpc_free_iostats(clnt->cl_metrics);
 648         kfree(clnt->cl_principal);
 649         clnt->cl_metrics = NULL;
 650         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 651         rpciod_down();
 652         kfree(clnt);
 653 }
 654
 655 /*
 656  * Free an RPC client
 657  */
 658 static void
 659 rpc_free_auth(struct rpc_clnt *clnt)
 660 {
 661         if (clnt->cl_auth == NULL) {
 662                 rpc_free_client(clnt);
 663                 return;
 664         }
 665
 666         /*
 667          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 668          *       release remaining GSS contexts. This mechanism ensures
 669          *       that it can do so safely.
 670          */
 671         atomic_inc(&clnt->cl_count);
 672         rpcauth_release(clnt->cl_auth);
 673         clnt->cl_auth = NULL;
 674         if (atomic_dec_and_test(&clnt->cl_count))
 675                 rpc_free_client(clnt);
 676 }
 677
 678 /*
 679  * Release reference to the RPC client
 680  */
 681 void
 682 rpc_release_client(struct rpc_clnt *clnt)
 683 {
 684         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 685
 686         if (list_empty(&clnt->cl_tasks))
 687                 wake_up(&destroy_wait);
 688         if (atomic_dec_and_test(&clnt->cl_count))
 689                 rpc_free_auth(clnt);
 690 }
 691
 692 /**
 693  * rpc_bind_new_program - bind a new RPC program to an existing client
 694  * @old: old rpc_client
 695  * @program: rpc program to set
 696  * @vers: rpc program version
 697  *
 698  * Clones the rpc client and sets up a new RPC program. This is mainly
 699  * of use for enabling different RPC programs to share the same transport.
 700  * The Sun NFSv2/v3 ACL protocol can do this.
 701  */
 702 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 703                                       const struct rpc_program *program,
 704                                       u32 vers)
 705 {
 706         struct rpc_create_args args = {
 707                 .program        = program,
 708                 .prognumber     = program->number,
 709                 .version        = vers,
 710                 .authflavor     = old->cl_auth->au_flavor,
 711                 .client_name    = old->cl_principal,
 712         };
 713         struct rpc_clnt *clnt;
 714         int err;
 715
 716         clnt = __rpc_clone_client(&args, old);
 717         if (IS_ERR(clnt))
 718                 goto out;
 719         err = rpc_ping(clnt);
 720         if (err != 0) {
 721                 rpc_shutdown_client(clnt);
 722                 clnt = ERR_PTR(err);
 723         }
 724 out:
 725         return clnt;
 726 }
 727 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 728
 729 void rpc_task_release_client(struct rpc_task *task)
 730 {
 731         struct rpc_clnt *clnt = task->tk_client;
 732
 733         if (clnt != NULL) {
 734                 /* Remove from client task list */
 735                 spin_lock(&clnt->cl_lock);
 736                 list_del(&task->tk_task);
 737                 spin_unlock(&clnt->cl_lock);
 738                 task->tk_client = NULL;
 739
 740                 rpc_release_client(clnt);
 741         }
 742 }
 743
 744 static
 745 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 746 {
 747         if (clnt != NULL) {
 748                 rpc_task_release_client(task);
 749                 task->tk_client = clnt;
 750                 atomic_inc(&clnt->cl_count);
 751                 if (clnt->cl_softrtry)
 752                         task->tk_flags |= RPC_TASK_SOFT;
 753                 if (sk_memalloc_socks()) {
 754                         struct rpc_xprt *xprt;
 755
 756                         rcu_read_lock();
 757                         xprt = rcu_dereference(clnt->cl_xprt);
 758                         if (xprt->swapper)
 759                                 task->tk_flags |= RPC_TASK_SWAPPER;
 760                         rcu_read_unlock();
 761                 }
 762                 /* Add to the client's list of all tasks */
 763                 spin_lock(&clnt->cl_lock);
 764                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 765                 spin_unlock(&clnt->cl_lock);
 766         }
 767 }
 768
 769 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 770 {
 771         rpc_task_release_client(task);
 772         rpc_task_set_client(task, clnt);
 773 }
 774 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 775
 776
 777 static void
 778 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 779 {
 780         if (msg != NULL) {
 781                 task->tk_msg.rpc_proc = msg->rpc_proc;
 782                 task->tk_msg.rpc_argp = msg->rpc_argp;
 783                 task->tk_msg.rpc_resp = msg->rpc_resp;
 784                 if (msg->rpc_cred != NULL)
 785                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 786         }
 787 }
 788
 789 /*
 790  * Default callback for async RPC calls
 791  */
 792 static void
 793 rpc_default_callback(struct rpc_task *task, void *data)
 794 {
 795 }
 796
 797 static const struct rpc_call_ops rpc_default_ops = {
 798         .rpc_call_done = rpc_default_callback,
 799 };
 800
 801 /**
 802  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 803  * @task_setup_data: pointer to task initialisation data
 804  */
 805 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 806 {
 807         struct rpc_task *task;
 808
 809         task = rpc_new_task(task_setup_data);
 810         if (IS_ERR(task))
 811                 goto out;
 812
 813         rpc_task_set_client(task, task_setup_data->rpc_client);
 814         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 815
 816         if (task->tk_action == NULL)
 817                 rpc_call_start(task);
 818
 819         atomic_inc(&task->tk_count);
 820         rpc_execute(task);
 821 out:
 822         return task;
 823 }
 824 EXPORT_SYMBOL_GPL(rpc_run_task);
 825
 826 /**
 827  * rpc_call_sync - Perform a synchronous RPC call
 828  * @clnt: pointer to RPC client
 829  * @msg: RPC call parameters
 830  * @flags: RPC call flags
 831  */
 832 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 833 {
 834         struct rpc_task *task;
 835         struct rpc_task_setup task_setup_data = {
 836                 .rpc_client = clnt,
 837                 .rpc_message = msg,
 838                 .callback_ops = &rpc_default_ops,
 839                 .flags = flags,
 840         };
 841         int status;
 842
 843         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 844         if (flags & RPC_TASK_ASYNC) {
 845                 rpc_release_calldata(task_setup_data.callback_ops,
 846                         task_setup_data.callback_data);
 847                 return -EINVAL;
 848         }
 849
 850         task = rpc_run_task(&task_setup_data);
 851         if (IS_ERR(task))
 852                 return PTR_ERR(task);
 853         status = task->tk_status;
 854         rpc_put_task(task);
 855         return status;
 856 }
 857 EXPORT_SYMBOL_GPL(rpc_call_sync);
 858
 859 /**
 860  * rpc_call_async - Perform an asynchronous RPC call
 861  * @clnt: pointer to RPC client
 862  * @msg: RPC call parameters
 863  * @flags: RPC call flags
 864  * @tk_ops: RPC call ops
 865  * @data: user call data
 866  */
 867 int
 868 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 869                const struct rpc_call_ops *tk_ops, void *data)
 870 {
 871         struct rpc_task *task;
 872         struct rpc_task_setup task_setup_data = {
 873                 .rpc_client = clnt,
 874                 .rpc_message = msg,
 875                 .callback_ops = tk_ops,
 876                 .callback_data = data,
 877                 .flags = flags|RPC_TASK_ASYNC,
 878         };
 879
 880         task = rpc_run_task(&task_setup_data);
 881         if (IS_ERR(task))
 882                 return PTR_ERR(task);
 883         rpc_put_task(task);
 884         return 0;
 885 }
 886 EXPORT_SYMBOL_GPL(rpc_call_async);
 887
 888 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 889 /**
 890  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 891  * rpc_execute against it
 892  * @req: RPC request
 893  * @tk_ops: RPC call ops
 894  */
 895 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 896                                 const struct rpc_call_ops *tk_ops)
 897 {
 898         struct rpc_task *task;
 899         struct xdr_buf *xbufp = &req->rq_snd_buf;
 900         struct rpc_task_setup task_setup_data = {
 901                 .callback_ops = tk_ops,
 902         };
 903
 904         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 905         /*
 906          * Create an rpc_task to send the data
 907          */
 908         task = rpc_new_task(&task_setup_data);
 909         if (IS_ERR(task)) {
 910                 xprt_free_bc_request(req);
 911                 goto out;
 912         }
 913         task->tk_rqstp = req;
 914
 915         /*
 916          * Set up the xdr_buf length.
 917          * This also indicates that the buffer is XDR encoded already.
 918          */
 919         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 920                         xbufp->tail[0].iov_len;
 921
 922         task->tk_action = call_bc_transmit;
 923         atomic_inc(&task->tk_count);
 924         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 925         rpc_execute(task);
 926
 927 out:
 928         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 929         return task;
 930 }
 931 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 932
 933 void
 934 rpc_call_start(struct rpc_task *task)
 935 {
 936         task->tk_action = call_start;
 937 }
 938 EXPORT_SYMBOL_GPL(rpc_call_start);
 939
 940 /**
 941  * rpc_peeraddr - extract remote peer address from clnt's xprt
 942  * @clnt: RPC client structure
 943  * @buf: target buffer
 944  * @bufsize: length of target buffer
 945  *
 946  * Returns the number of bytes that are actually in the stored address.
 947  */
 948 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 949 {
 950         size_t bytes;
 951         struct rpc_xprt *xprt;
 952
 953         rcu_read_lock();
 954         xprt = rcu_dereference(clnt->cl_xprt);
 955
 956         bytes = xprt->addrlen;
 957         if (bytes > bufsize)
 958                 bytes = bufsize;
 959         memcpy(buf, &xprt->addr, bytes);
 960         rcu_read_unlock();
 961
 962         return bytes;
 963 }
 964 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 965
 966 /**
 967  * rpc_peeraddr2str - return remote peer address in printable format
 968  * @clnt: RPC client structure
 969  * @format: address format
 970  *
 971  * NB: the lifetime of the memory referenced by the returned pointer is
 972  * the same as the rpc_xprt itself.  As long as the caller uses this
 973  * pointer, it must hold the RCU read lock.
 974  */
 975 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 976                              enum rpc_display_format_t format)
 977 {
 978         struct rpc_xprt *xprt;
 979
 980         xprt = rcu_dereference(clnt->cl_xprt);
 981
 982         if (xprt->address_strings[format] != NULL)
 983                 return xprt->address_strings[format];
 984         else
 985                 return "unprintable";
 986 }
 987 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 988
 989 static const struct sockaddr_in rpc_inaddr_loopback = {
 990         .sin_family             = AF_INET,
 991         .sin_addr.s_addr        = htonl(INADDR_ANY),
 992 };
 993
 994 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 995         .sin6_family            = AF_INET6,
 996         .sin6_addr              = IN6ADDR_ANY_INIT,
 997 };
 998
 999 /*
1000  * Try a getsockname() on a connected datagram socket.  Using a
1001  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1002  * This conserves the ephemeral port number space.
1003  *
1004  * Returns zero and fills in "buf" if successful; otherwise, a
1005  * negative errno is returned.
1006  */
1007 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1008                         struct sockaddr *buf, int buflen)
1009 {
1010         struct socket *sock;
1011         int err;
1012
1013         err = __sock_create(net, sap->sa_family,
1014                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1015         if (err < 0) {
1016                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1017                 goto out;
1018         }
1019
1020         switch (sap->sa_family) {
1021         case AF_INET:
1022                 err = kernel_bind(sock,
1023                                 (struct sockaddr *)&rpc_inaddr_loopback,
1024                                 sizeof(rpc_inaddr_loopback));
1025                 break;
1026         case AF_INET6:
1027                 err = kernel_bind(sock,
1028                                 (struct sockaddr *)&rpc_in6addr_loopback,
1029                                 sizeof(rpc_in6addr_loopback));
1030                 break;
1031         default:
1032                 err = -EAFNOSUPPORT;
1033                 goto out;
1034         }
1035         if (err < 0) {
1036                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1037                 goto out_release;
1038         }
1039
1040         err = kernel_connect(sock, sap, salen, 0);
1041         if (err < 0) {
1042                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1043                 goto out_release;
1044         }
1045
1046         err = kernel_getsockname(sock, buf, &buflen);
1047         if (err < 0) {
1048                 dprintk("RPC:       getsockname failed (%d)\n", err);
1049                 goto out_release;
1050         }
1051
1052         err = 0;
1053         if (buf->sa_family == AF_INET6) {
1054                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1055                 sin6->sin6_scope_id = 0;
1056         }
1057         dprintk("RPC:       %s succeeded\n", __func__);
1058
1059 out_release:
1060         sock_release(sock);
1061 out:
1062         return err;
1063 }
1064
1065 /*
1066  * Scraping a connected socket failed, so we don't have a useable
1067  * local address.  Fallback: generate an address that will prevent
1068  * the server from calling us back.
1069  *
1070  * Returns zero and fills in "buf" if successful; otherwise, a
1071  * negative errno is returned.
1072  */
1073 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1074 {
1075         switch (family) {
1076         case AF_INET:
1077                 if (buflen < sizeof(rpc_inaddr_loopback))
1078                         return -EINVAL;
1079                 memcpy(buf, &rpc_inaddr_loopback,
1080                                 sizeof(rpc_inaddr_loopback));
1081                 break;
1082         case AF_INET6:
1083                 if (buflen < sizeof(rpc_in6addr_loopback))
1084                         return -EINVAL;
1085                 memcpy(buf, &rpc_in6addr_loopback,
1086                                 sizeof(rpc_in6addr_loopback));
1087         default:
1088                 dprintk("RPC:       %s: address family not supported\n",
1089                         __func__);
1090                 return -EAFNOSUPPORT;
1091         }
1092         dprintk("RPC:       %s: succeeded\n", __func__);
1093         return 0;
1094 }
1095
1096 /**
1097  * rpc_localaddr - discover local endpoint address for an RPC client
1098  * @clnt: RPC client structure
1099  * @buf: target buffer
1100  * @buflen: size of target buffer, in bytes
1101  *
1102  * Returns zero and fills in "buf" and "buflen" if successful;
1103  * otherwise, a negative errno is returned.
1104  *
1105  * This works even if the underlying transport is not currently connected,
1106  * or if the upper layer never previously provided a source address.
1107  *
1108  * The result of this function call is transient: multiple calls in
1109  * succession may give different results, depending on how local
1110  * networking configuration changes over time.
1111  */
1112 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1113 {
1114         struct sockaddr_storage address;
1115         struct sockaddr *sap = (struct sockaddr *)&address;
1116         struct rpc_xprt *xprt;
1117         struct net *net;
1118         size_t salen;
1119         int err;
1120
1121         rcu_read_lock();
1122         xprt = rcu_dereference(clnt->cl_xprt);
1123         salen = xprt->addrlen;
1124         memcpy(sap, &xprt->addr, salen);
1125         net = get_net(xprt->xprt_net);
1126         rcu_read_unlock();
1127
1128         rpc_set_port(sap, 0);
1129         err = rpc_sockname(net, sap, salen, buf, buflen);
1130         put_net(net);
1131         if (err != 0)
1132                 /* Couldn't discover local address, return ANYADDR */
1133                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1134         return 0;
1135 }
1136 EXPORT_SYMBOL_GPL(rpc_localaddr);
1137
1138 void
1139 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1140 {
1141         struct rpc_xprt *xprt;
1142
1143         rcu_read_lock();
1144         xprt = rcu_dereference(clnt->cl_xprt);
1145         if (xprt->ops->set_buffer_size)
1146                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1147         rcu_read_unlock();
1148 }
1149 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1150
1151 /**
1152  * rpc_protocol - Get transport protocol number for an RPC client
1153  * @clnt: RPC client to query
1154  *
1155  */
1156 int rpc_protocol(struct rpc_clnt *clnt)
1157 {
1158         int protocol;
1159
1160         rcu_read_lock();
1161         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1162         rcu_read_unlock();
1163         return protocol;
1164 }
1165 EXPORT_SYMBOL_GPL(rpc_protocol);
1166
1167 /**
1168  * rpc_net_ns - Get the network namespace for this RPC client
1169  * @clnt: RPC client to query
1170  *
1171  */
1172 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1173 {
1174         struct net *ret;
1175
1176         rcu_read_lock();
1177         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1178         rcu_read_unlock();
1179         return ret;
1180 }
1181 EXPORT_SYMBOL_GPL(rpc_net_ns);
1182
1183 /**
1184  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1185  * @clnt: RPC client to query
1186  *
1187  * For stream transports, this is one RPC record fragment (see RFC
1188  * 1831), as we don't support multi-record requests yet.  For datagram
1189  * transports, this is the size of an IP packet minus the IP, UDP, and
1190  * RPC header sizes.
1191  */
1192 size_t rpc_max_payload(struct rpc_clnt *clnt)
1193 {
1194         size_t ret;
1195
1196         rcu_read_lock();
1197         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1198         rcu_read_unlock();
1199         return ret;
1200 }
1201 EXPORT_SYMBOL_GPL(rpc_max_payload);
1202
1203 /**
1204  * rpc_force_rebind - force transport to check that remote port is unchanged
1205  * @clnt: client to rebind
1206  *
1207  */
1208 void rpc_force_rebind(struct rpc_clnt *clnt)
1209 {
1210         if (clnt->cl_autobind) {
1211                 rcu_read_lock();
1212                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1213                 rcu_read_unlock();
1214         }
1215 }
1216 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1217
1218 /*
1219  * Restart an (async) RPC call from the call_prepare state.
1220  * Usually called from within the exit handler.
1221  */
1222 int
1223 rpc_restart_call_prepare(struct rpc_task *task)
1224 {
1225         if (RPC_ASSASSINATED(task))
1226                 return 0;
1227         task->tk_action = call_start;
1228         if (task->tk_ops->rpc_call_prepare != NULL)
1229                 task->tk_action = rpc_prepare_task;
1230         return 1;
1231 }
1232 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1233
1234 /*
1235  * Restart an (async) RPC call. Usually called from within the
1236  * exit handler.
1237  */
1238 int
1239 rpc_restart_call(struct rpc_task *task)
1240 {
1241         if (RPC_ASSASSINATED(task))
1242                 return 0;
1243         task->tk_action = call_start;
1244         return 1;
1245 }
1246 EXPORT_SYMBOL_GPL(rpc_restart_call);
1247
1248 #ifdef RPC_DEBUG
1249 static const char *rpc_proc_name(const struct rpc_task *task)
1250 {
1251         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1252
1253         if (proc) {
1254                 if (proc->p_name)
1255                         return proc->p_name;
1256                 else
1257                         return "NULL";
1258         } else
1259                 return "no proc";
1260 }
1261 #endif
1262
1263 /*
1264  * 0.  Initial state
1265  *
1266  *     Other FSM states can be visited zero or more times, but
1267  *     this state is visited exactly once for each RPC.
1268  */
1269 static void
1270 call_start(struct rpc_task *task)
1271 {
1272         struct rpc_clnt *clnt = task->tk_client;
1273
1274         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1275                         clnt->cl_protname, clnt->cl_vers,
1276                         rpc_proc_name(task),
1277                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1278
1279         /* Increment call count */
1280         task->tk_msg.rpc_proc->p_count++;
1281         clnt->cl_stats->rpccnt++;
1282         task->tk_action = call_reserve;
1283 }
1284
1285 /*
1286  * 1.   Reserve an RPC call slot
1287  */
1288 static void
1289 call_reserve(struct rpc_task *task)
1290 {
1291         dprint_status(task);
1292
1293         task->tk_status  = 0;
1294         task->tk_action  = call_reserveresult;
1295         xprt_reserve(task);
1296 }
1297
1298 /*
1299  * 1b.  Grok the result of xprt_reserve()
1300  */
1301 static void
1302 call_reserveresult(struct rpc_task *task)
1303 {
1304         int status = task->tk_status;
1305
1306         dprint_status(task);
1307
1308         /*
1309          * After a call to xprt_reserve(), we must have either
1310          * a request slot or else an error status.
1311          */
1312         task->tk_status = 0;
1313         if (status >= 0) {
1314                 if (task->tk_rqstp) {
1315                         task->tk_action = call_refresh;
1316                         return;
1317                 }
1318
1319                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1320                                 __func__, status);
1321                 rpc_exit(task, -EIO);
1322                 return;
1323         }
1324
1325         /*
1326          * Even though there was an error, we may have acquired
1327          * a request slot somehow.  Make sure not to leak it.
1328          */
1329         if (task->tk_rqstp) {
1330                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1331                                 __func__, status);
1332                 xprt_release(task);
1333         }
1334
1335         switch (status) {
1336         case -ENOMEM:
1337                 rpc_delay(task, HZ >> 2);
1338         case -EAGAIN:   /* woken up; retry */
1339                 task->tk_action = call_reserve;
1340                 return;
1341         case -EIO:      /* probably a shutdown */
1342                 break;
1343         default:
1344                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1345                                 __func__, status);
1346                 break;
1347         }
1348         rpc_exit(task, status);
1349 }
1350
1351 /*
1352  * 2.   Bind and/or refresh the credentials
1353  */
1354 static void
1355 call_refresh(struct rpc_task *task)
1356 {
1357         dprint_status(task);
1358
1359         task->tk_action = call_refreshresult;
1360         task->tk_status = 0;
1361         task->tk_client->cl_stats->rpcauthrefresh++;
1362         rpcauth_refreshcred(task);
1363 }
1364
1365 /*
1366  * 2a.  Process the results of a credential refresh
1367  */
1368 static void
1369 call_refreshresult(struct rpc_task *task)
1370 {
1371         int status = task->tk_status;
1372
1373         dprint_status(task);
1374
1375         task->tk_status = 0;
1376         task->tk_action = call_refresh;
1377         switch (status) {
1378         case 0:
1379                 if (rpcauth_uptodatecred(task))
1380                         task->tk_action = call_allocate;
1381                 return;
1382         case -ETIMEDOUT:
1383                 rpc_delay(task, 3*HZ);
1384         case -EKEYEXPIRED:
1385         case -EAGAIN:
1386                 status = -EACCES;
1387                 if (!task->tk_cred_retry)
1388                         break;
1389                 task->tk_cred_retry--;
1390                 dprintk("RPC: %5u %s: retry refresh creds\n",
1391                                 task->tk_pid, __func__);
1392                 return;
1393         }
1394         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1395                                 task->tk_pid, __func__, status);
1396         rpc_exit(task, status);
1397 }
1398
1399 /*
1400  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1401  *      (Note: buffer memory is freed in xprt_release).
1402  */
1403 static void
1404 call_allocate(struct rpc_task *task)
1405 {
1406         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1407         struct rpc_rqst *req = task->tk_rqstp;
1408         struct rpc_xprt *xprt = task->tk_xprt;
1409         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1410
1411         dprint_status(task);
1412
1413         task->tk_status = 0;
1414         task->tk_action = call_bind;
1415
1416         if (req->rq_buffer)
1417                 return;
1418
1419         if (proc->p_proc != 0) {
1420                 BUG_ON(proc->p_arglen == 0);
1421                 if (proc->p_decode != NULL)
1422                         BUG_ON(proc->p_replen == 0);
1423         }
1424
1425         /*
1426          * Calculate the size (in quads) of the RPC call
1427          * and reply headers, and convert both values
1428          * to byte sizes.
1429          */
1430         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1431         req->rq_callsize <<= 2;
1432         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1433         req->rq_rcvsize <<= 2;
1434
1435         req->rq_buffer = xprt->ops->buf_alloc(task,
1436                                         req->rq_callsize + req->rq_rcvsize);
1437         if (req->rq_buffer != NULL)
1438                 return;
1439
1440         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1441
1442         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1443                 task->tk_action = call_allocate;
1444                 rpc_delay(task, HZ>>4);
1445                 return;
1446         }
1447
1448         rpc_exit(task, -ERESTARTSYS);
1449 }
1450
1451 static inline int
1452 rpc_task_need_encode(struct rpc_task *task)
1453 {
1454         return task->tk_rqstp->rq_snd_buf.len == 0;
1455 }
1456
1457 static inline void
1458 rpc_task_force_reencode(struct rpc_task *task)
1459 {
1460         task->tk_rqstp->rq_snd_buf.len = 0;
1461         task->tk_rqstp->rq_bytes_sent = 0;
1462 }
1463
1464 static inline void
1465 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1466 {
1467         buf->head[0].iov_base = start;
1468         buf->head[0].iov_len = len;
1469         buf->tail[0].iov_len = 0;
1470         buf->page_len = 0;
1471         buf->flags = 0;
1472         buf->len = 0;
1473         buf->buflen = len;
1474 }
1475
1476 /*
1477  * 3.   Encode arguments of an RPC call
1478  */
1479 static void
1480 rpc_xdr_encode(struct rpc_task *task)
1481 {
1482         struct rpc_rqst *req = task->tk_rqstp;
1483         kxdreproc_t     encode;
1484         __be32          *p;
1485
1486         dprint_status(task);
1487
1488         rpc_xdr_buf_init(&req->rq_snd_buf,
1489                          req->rq_buffer,
1490                          req->rq_callsize);
1491         rpc_xdr_buf_init(&req->rq_rcv_buf,
1492                          (char *)req->rq_buffer + req->rq_callsize,
1493                          req->rq_rcvsize);
1494
1495         p = rpc_encode_header(task);
1496         if (p == NULL) {
1497                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1498                 rpc_exit(task, -EIO);
1499                 return;
1500         }
1501
1502         encode = task->tk_msg.rpc_proc->p_encode;
1503         if (encode == NULL)
1504                 return;
1505
1506         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1507                         task->tk_msg.rpc_argp);
1508 }
1509
1510 /*
1511  * 4.   Get the server port number if not yet set
1512  */
1513 static void
1514 call_bind(struct rpc_task *task)
1515 {
1516         struct rpc_xprt *xprt = task->tk_xprt;
1517
1518         dprint_status(task);
1519
1520         task->tk_action = call_connect;
1521         if (!xprt_bound(xprt)) {
1522                 task->tk_action = call_bind_status;
1523                 task->tk_timeout = xprt->bind_timeout;
1524                 xprt->ops->rpcbind(task);
1525         }
1526 }
1527
1528 /*
1529  * 4a.  Sort out bind result
1530  */
1531 static void
1532 call_bind_status(struct rpc_task *task)
1533 {
1534         int status = -EIO;
1535
1536         if (task->tk_status >= 0) {
1537                 dprint_status(task);
1538                 task->tk_status = 0;
1539                 task->tk_action = call_connect;
1540                 return;
1541         }
1542
1543         trace_rpc_bind_status(task);
1544         switch (task->tk_status) {
1545         case -ENOMEM:
1546                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1547                 rpc_delay(task, HZ >> 2);
1548                 goto retry_timeout;
1549         case -EACCES:
1550                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1551                                 "unavailable\n", task->tk_pid);
1552                 /* fail immediately if this is an RPC ping */
1553                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1554                         status = -EOPNOTSUPP;
1555                         break;
1556                 }
1557                 if (task->tk_rebind_retry == 0)
1558                         break;
1559                 task->tk_rebind_retry--;
1560                 rpc_delay(task, 3*HZ);
1561                 goto retry_timeout;
1562         case -ETIMEDOUT:
1563                 dprintk("RPC: %5u rpcbind request timed out\n",
1564                                 task->tk_pid);
1565                 goto retry_timeout;
1566         case -EPFNOSUPPORT:
1567                 /* server doesn't support any rpcbind version we know of */
1568                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1569                                 task->tk_pid);
1570                 break;
1571         case -EPROTONOSUPPORT:
1572                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1573                                 task->tk_pid);
1574                 task->tk_status = 0;
1575                 task->tk_action = call_bind;
1576                 return;
1577         case -ECONNREFUSED:             /* connection problems */
1578         case -ECONNRESET:
1579         case -ENOTCONN:
1580         case -EHOSTDOWN:
1581         case -EHOSTUNREACH:
1582         case -ENETUNREACH:
1583         case -EPIPE:
1584                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1585                                 task->tk_pid, task->tk_status);
1586                 if (!RPC_IS_SOFTCONN(task)) {
1587                         rpc_delay(task, 5*HZ);
1588                         goto retry_timeout;
1589                 }
1590                 status = task->tk_status;
1591                 break;
1592         default:
1593                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1594                                 task->tk_pid, -task->tk_status);
1595         }
1596
1597         rpc_exit(task, status);
1598         return;
1599
1600 retry_timeout:
1601         task->tk_action = call_timeout;
1602 }
1603
1604 /*
1605  * 4b.  Connect to the RPC server
1606  */
1607 static void
1608 call_connect(struct rpc_task *task)
1609 {
1610         struct rpc_xprt *xprt = task->tk_xprt;
1611
1612         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1613                         task->tk_pid, xprt,
1614                         (xprt_connected(xprt) ? "is" : "is not"));
1615
1616         task->tk_action = call_transmit;
1617         if (!xprt_connected(xprt)) {
1618                 task->tk_action = call_connect_status;
1619                 if (task->tk_status < 0)
1620                         return;
1621                 xprt_connect(task);
1622         }
1623 }
1624
1625 /*
1626  * 4c.  Sort out connect result
1627  */
1628 static void
1629 call_connect_status(struct rpc_task *task)
1630 {
1631         struct rpc_clnt *clnt = task->tk_client;
1632         int status = task->tk_status;
1633
1634         dprint_status(task);
1635
1636         task->tk_status = 0;
1637         if (status >= 0 || status == -EAGAIN) {
1638                 clnt->cl_stats->netreconn++;
1639                 task->tk_action = call_transmit;
1640                 return;
1641         }
1642
1643         trace_rpc_connect_status(task, status);
1644         switch (status) {
1645                 /* if soft mounted, test if we've timed out */
1646         case -ETIMEDOUT:
1647                 task->tk_action = call_timeout;
1648                 break;
1649         default:
1650                 rpc_exit(task, -EIO);
1651         }
1652 }
1653
1654 /*
1655  * 5.   Transmit the RPC request, and wait for reply
1656  */
1657 static void
1658 call_transmit(struct rpc_task *task)
1659 {
1660         dprint_status(task);
1661
1662         task->tk_action = call_status;
1663         if (task->tk_status < 0)
1664                 return;
1665         task->tk_status = xprt_prepare_transmit(task);
1666         if (task->tk_status != 0)
1667                 return;
1668         task->tk_action = call_transmit_status;
1669         /* Encode here so that rpcsec_gss can use correct sequence number. */
1670         if (rpc_task_need_encode(task)) {
1671                 rpc_xdr_encode(task);
1672                 /* Did the encode result in an error condition? */
1673                 if (task->tk_status != 0) {
1674                         /* Was the error nonfatal? */
1675                         if (task->tk_status == -EAGAIN)
1676                                 rpc_delay(task, HZ >> 4);
1677                         else
1678                                 rpc_exit(task, task->tk_status);
1679                         return;
1680                 }
1681         }
1682         xprt_transmit(task);
1683         if (task->tk_status < 0)
1684                 return;
1685         /*
1686          * On success, ensure that we call xprt_end_transmit() before sleeping
1687          * in order to allow access to the socket to other RPC requests.
1688          */
1689         call_transmit_status(task);
1690         if (rpc_reply_expected(task))
1691                 return;
1692         task->tk_action = rpc_exit_task;
1693         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1694 }
1695
1696 /*
1697  * 5a.  Handle cleanup after a transmission
1698  */
1699 static void
1700 call_transmit_status(struct rpc_task *task)
1701 {
1702         task->tk_action = call_status;
1703
1704         /*
1705          * Common case: success.  Force the compiler to put this
1706          * test first.
1707          */
1708         if (task->tk_status == 0) {
1709                 xprt_end_transmit(task);
1710                 rpc_task_force_reencode(task);
1711                 return;
1712         }
1713
1714         switch (task->tk_status) {
1715         case -EAGAIN:
1716                 break;
1717         default:
1718                 dprint_status(task);
1719                 xprt_end_transmit(task);
1720                 rpc_task_force_reencode(task);
1721                 break;
1722                 /*
1723                  * Special cases: if we've been waiting on the
1724                  * socket's write_space() callback, or if the
1725                  * socket just returned a connection error,
1726                  * then hold onto the transport lock.
1727                  */
1728         case -ECONNREFUSED:
1729         case -EHOSTDOWN:
1730         case -EHOSTUNREACH:
1731         case -ENETUNREACH:
1732                 if (RPC_IS_SOFTCONN(task)) {
1733                         xprt_end_transmit(task);
1734                         rpc_exit(task, task->tk_status);
1735                         break;
1736                 }
1737         case -ECONNRESET:
1738         case -ENOTCONN:
1739         case -EPIPE:
1740                 rpc_task_force_reencode(task);
1741         }
1742 }
1743
1744 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1745 /*
1746  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1747  * addition, disconnect on connectivity errors.
1748  */
1749 static void
1750 call_bc_transmit(struct rpc_task *task)
1751 {
1752         struct rpc_rqst *req = task->tk_rqstp;
1753
1754         task->tk_status = xprt_prepare_transmit(task);
1755         if (task->tk_status == -EAGAIN) {
1756                 /*
1757                  * Could not reserve the transport. Try again after the
1758                  * transport is released.
1759                  */
1760                 task->tk_status = 0;
1761                 task->tk_action = call_bc_transmit;
1762                 return;
1763         }
1764
1765         task->tk_action = rpc_exit_task;
1766         if (task->tk_status < 0) {
1767                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1768                         "error: %d\n", task->tk_status);
1769                 return;
1770         }
1771
1772         xprt_transmit(task);
1773         xprt_end_transmit(task);
1774         dprint_status(task);
1775         switch (task->tk_status) {
1776         case 0:
1777                 /* Success */
1778                 break;
1779         case -EHOSTDOWN:
1780         case -EHOSTUNREACH:
1781         case -ENETUNREACH:
1782         case -ETIMEDOUT:
1783                 /*
1784                  * Problem reaching the server.  Disconnect and let the
1785                  * forechannel reestablish the connection.  The server will
1786                  * have to retransmit the backchannel request and we'll
1787                  * reprocess it.  Since these ops are idempotent, there's no
1788                  * need to cache our reply at this time.
1789                  */
1790                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1791                         "error: %d\n", task->tk_status);
1792                 xprt_conditional_disconnect(task->tk_xprt,
1793                         req->rq_connect_cookie);
1794                 break;
1795         default:
1796                 /*
1797                  * We were unable to reply and will have to drop the
1798                  * request.  The server should reconnect and retransmit.
1799                  */
1800                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1801                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1802                         "error: %d\n", task->tk_status);
1803                 break;
1804         }
1805         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1806 }
1807 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1808
1809 /*
1810  * 6.   Sort out the RPC call status
1811  */
1812 static void
1813 call_status(struct rpc_task *task)
1814 {
1815         struct rpc_clnt *clnt = task->tk_client;
1816         struct rpc_rqst *req = task->tk_rqstp;
1817         int             status;
1818
1819         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1820                 task->tk_status = req->rq_reply_bytes_recvd;
1821
1822         dprint_status(task);
1823
1824         status = task->tk_status;
1825         if (status >= 0) {
1826                 task->tk_action = call_decode;
1827                 return;
1828         }
1829
1830         trace_rpc_call_status(task);
1831         task->tk_status = 0;
1832         switch(status) {
1833         case -EHOSTDOWN:
1834         case -EHOSTUNREACH:
1835         case -ENETUNREACH:
1836                 /*
1837                  * Delay any retries for 3 seconds, then handle as if it
1838                  * were a timeout.
1839                  */
1840                 rpc_delay(task, 3*HZ);
1841         case -ETIMEDOUT:
1842                 task->tk_action = call_timeout;
1843                 if (task->tk_client->cl_discrtry)
1844                         xprt_conditional_disconnect(task->tk_xprt,
1845                                         req->rq_connect_cookie);
1846                 break;
1847         case -ECONNRESET:
1848         case -ECONNREFUSED:
1849                 rpc_force_rebind(clnt);
1850                 rpc_delay(task, 3*HZ);
1851         case -EPIPE:
1852         case -ENOTCONN:
1853                 task->tk_action = call_bind;
1854                 break;
1855         case -EAGAIN:
1856                 task->tk_action = call_transmit;
1857                 break;
1858         case -EIO:
1859                 /* shutdown or soft timeout */
1860                 rpc_exit(task, status);
1861                 break;
1862         default:
1863                 if (clnt->cl_chatty)
1864                         printk("%s: RPC call returned error %d\n",
1865                                clnt->cl_protname, -status);
1866                 rpc_exit(task, status);
1867         }
1868 }
1869
1870 /*
1871  * 6a.  Handle RPC timeout
1872  *      We do not release the request slot, so we keep using the
1873  *      same XID for all retransmits.
1874  */
1875 static void
1876 call_timeout(struct rpc_task *task)
1877 {
1878         struct rpc_clnt *clnt = task->tk_client;
1879
1880         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1881                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1882                 goto retry;
1883         }
1884
1885         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1886         task->tk_timeouts++;
1887
1888         if (RPC_IS_SOFTCONN(task)) {
1889                 rpc_exit(task, -ETIMEDOUT);
1890                 return;
1891         }
1892         if (RPC_IS_SOFT(task)) {
1893                 if (clnt->cl_chatty) {
1894                         rcu_read_lock();
1895                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1896                                 clnt->cl_protname,
1897                                 rcu_dereference(clnt->cl_xprt)->servername);
1898                         rcu_read_unlock();
1899                 }
1900                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1901                         rpc_exit(task, -ETIMEDOUT);
1902                 else
1903                         rpc_exit(task, -EIO);
1904                 return;
1905         }
1906
1907         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1908                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1909                 if (clnt->cl_chatty) {
1910                         rcu_read_lock();
1911                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1912                         clnt->cl_protname,
1913                         rcu_dereference(clnt->cl_xprt)->servername);
1914                         rcu_read_unlock();
1915                 }
1916         }
1917         rpc_force_rebind(clnt);
1918         /*
1919          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1920          * event? RFC2203 requires the server to drop all such requests.
1921          */
1922         rpcauth_invalcred(task);
1923
1924 retry:
1925         clnt->cl_stats->rpcretrans++;
1926         task->tk_action = call_bind;
1927         task->tk_status = 0;
1928 }
1929
1930 /*
1931  * 7.   Decode the RPC reply
1932  */
1933 static void
1934 call_decode(struct rpc_task *task)
1935 {
1936         struct rpc_clnt *clnt = task->tk_client;
1937         struct rpc_rqst *req = task->tk_rqstp;
1938         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1939         __be32          *p;
1940
1941         dprint_status(task);
1942
1943         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1944                 if (clnt->cl_chatty) {
1945                         rcu_read_lock();
1946                         printk(KERN_NOTICE "%s: server %s OK\n",
1947                                 clnt->cl_protname,
1948                                 rcu_dereference(clnt->cl_xprt)->servername);
1949                         rcu_read_unlock();
1950                 }
1951                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1952         }
1953
1954         /*
1955          * Ensure that we see all writes made by xprt_complete_rqst()
1956          * before it changed req->rq_reply_bytes_recvd.
1957          */
1958         smp_rmb();
1959         req->rq_rcv_buf.len = req->rq_private_buf.len;
1960
1961         /* Check that the softirq receive buffer is valid */
1962         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1963                                 sizeof(req->rq_rcv_buf)) != 0);
1964
1965         if (req->rq_rcv_buf.len < 12) {
1966                 if (!RPC_IS_SOFT(task)) {
1967                         task->tk_action = call_bind;
1968                         clnt->cl_stats->rpcretrans++;
1969                         goto out_retry;
1970                 }
1971                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1972                                 clnt->cl_protname, task->tk_status);
1973                 task->tk_action = call_timeout;
1974                 goto out_retry;
1975         }
1976
1977         p = rpc_verify_header(task);
1978         if (IS_ERR(p)) {
1979                 if (p == ERR_PTR(-EAGAIN))
1980                         goto out_retry;
1981                 return;
1982         }
1983
1984         task->tk_action = rpc_exit_task;
1985
1986         if (decode) {
1987                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1988                                                       task->tk_msg.rpc_resp);
1989         }
1990         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1991                         task->tk_status);
1992         return;
1993 out_retry:
1994         task->tk_status = 0;
1995         /* Note: rpc_verify_header() may have freed the RPC slot */
1996         if (task->tk_rqstp == req) {
1997                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1998                 if (task->tk_client->cl_discrtry)
1999                         xprt_conditional_disconnect(task->tk_xprt,
2000                                         req->rq_connect_cookie);
2001         }
2002 }
2003
2004 static __be32 *
2005 rpc_encode_header(struct rpc_task *task)
2006 {
2007         struct rpc_clnt *clnt = task->tk_client;
2008         struct rpc_rqst *req = task->tk_rqstp;
2009         __be32          *p = req->rq_svec[0].iov_base;
2010
2011         /* FIXME: check buffer size? */
2012
2013         p = xprt_skip_transport_header(task->tk_xprt, p);
2014         *p++ = req->rq_xid;             /* XID */
2015         *p++ = htonl(RPC_CALL);         /* CALL */
2016         *p++ = htonl(RPC_VERSION);      /* RPC version */
2017         *p++ = htonl(clnt->cl_prog);    /* program number */
2018         *p++ = htonl(clnt->cl_vers);    /* program version */
2019         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2020         p = rpcauth_marshcred(task, p);
2021         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2022         return p;
2023 }
2024
2025 static __be32 *
2026 rpc_verify_header(struct rpc_task *task)
2027 {
2028         struct rpc_clnt *clnt = task->tk_client;
2029         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2030         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2031         __be32  *p = iov->iov_base;
2032         u32 n;
2033         int error = -EACCES;
2034
2035         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2036                 /* RFC-1014 says that the representation of XDR data must be a
2037                  * multiple of four bytes
2038                  * - if it isn't pointer subtraction in the NFS client may give
2039                  *   undefined results
2040                  */
2041                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2042                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2043                        task->tk_rqstp->rq_rcv_buf.len);
2044                 goto out_eio;
2045         }
2046         if ((len -= 3) < 0)
2047                 goto out_overflow;
2048
2049         p += 1; /* skip XID */
2050         if ((n = ntohl(*p++)) != RPC_REPLY) {
2051                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2052                         task->tk_pid, __func__, n);
2053                 goto out_garbage;
2054         }
2055
2056         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2057                 if (--len < 0)
2058                         goto out_overflow;
2059                 switch ((n = ntohl(*p++))) {
2060                 case RPC_AUTH_ERROR:
2061                         break;
2062                 case RPC_MISMATCH:
2063                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2064                                 task->tk_pid, __func__);
2065                         error = -EPROTONOSUPPORT;
2066                         goto out_err;
2067                 default:
2068                         dprintk("RPC: %5u %s: RPC call rejected, "
2069                                 "unknown error: %x\n",
2070                                 task->tk_pid, __func__, n);
2071                         goto out_eio;
2072                 }
2073                 if (--len < 0)
2074                         goto out_overflow;
2075                 switch ((n = ntohl(*p++))) {
2076                 case RPC_AUTH_REJECTEDCRED:
2077                 case RPC_AUTH_REJECTEDVERF:
2078                 case RPCSEC_GSS_CREDPROBLEM:
2079                 case RPCSEC_GSS_CTXPROBLEM:
2080                         if (!task->tk_cred_retry)
2081                                 break;
2082                         task->tk_cred_retry--;
2083                         dprintk("RPC: %5u %s: retry stale creds\n",
2084                                         task->tk_pid, __func__);
2085                         rpcauth_invalcred(task);
2086                         /* Ensure we obtain a new XID! */
2087                         xprt_release(task);
2088                         task->tk_action = call_reserve;
2089                         goto out_retry;
2090                 case RPC_AUTH_BADCRED:
2091                 case RPC_AUTH_BADVERF:
2092                         /* possibly garbled cred/verf? */
2093                         if (!task->tk_garb_retry)
2094                                 break;
2095                         task->tk_garb_retry--;
2096                         dprintk("RPC: %5u %s: retry garbled creds\n",
2097                                         task->tk_pid, __func__);
2098                         task->tk_action = call_bind;
2099                         goto out_retry;
2100                 case RPC_AUTH_TOOWEAK:
2101                         rcu_read_lock();
2102                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2103                                "authentication.\n",
2104                                rcu_dereference(clnt->cl_xprt)->servername);
2105                         rcu_read_unlock();
2106                         break;
2107                 default:
2108                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2109                                         task->tk_pid, __func__, n);
2110                         error = -EIO;
2111                 }
2112                 dprintk("RPC: %5u %s: call rejected %d\n",
2113                                 task->tk_pid, __func__, n);
2114                 goto out_err;
2115         }
2116         if (!(p = rpcauth_checkverf(task, p))) {
2117                 dprintk("RPC: %5u %s: auth check failed\n",
2118                                 task->tk_pid, __func__);
2119                 goto out_garbage;               /* bad verifier, retry */
2120         }
2121         len = p - (__be32 *)iov->iov_base - 1;
2122         if (len < 0)
2123                 goto out_overflow;
2124         switch ((n = ntohl(*p++))) {
2125         case RPC_SUCCESS:
2126                 return p;
2127         case RPC_PROG_UNAVAIL:
2128                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2129                                 "by server %s\n", task->tk_pid, __func__,
2130                                 (unsigned int)clnt->cl_prog,
2131                                 rcu_dereference(clnt->cl_xprt)->servername);
2132                 error = -EPFNOSUPPORT;
2133                 goto out_err;
2134         case RPC_PROG_MISMATCH:
2135                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2136                                 "by server %s\n", task->tk_pid, __func__,
2137                                 (unsigned int)clnt->cl_prog,
2138                                 (unsigned int)clnt->cl_vers,
2139                                 rcu_dereference(clnt->cl_xprt)->servername);
2140                 error = -EPROTONOSUPPORT;
2141                 goto out_err;
2142         case RPC_PROC_UNAVAIL:
2143                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2144                                 "version %u on server %s\n",
2145                                 task->tk_pid, __func__,
2146                                 rpc_proc_name(task),
2147                                 clnt->cl_prog, clnt->cl_vers,
2148                                 rcu_dereference(clnt->cl_xprt)->servername);
2149                 error = -EOPNOTSUPP;
2150                 goto out_err;
2151         case RPC_GARBAGE_ARGS:
2152                 dprintk("RPC: %5u %s: server saw garbage\n",
2153                                 task->tk_pid, __func__);
2154                 break;                  /* retry */
2155         default:
2156                 dprintk("RPC: %5u %s: server accept status: %x\n",
2157                                 task->tk_pid, __func__, n);
2158                 /* Also retry */
2159         }
2160
2161 out_garbage:
2162         clnt->cl_stats->rpcgarbage++;
2163         if (task->tk_garb_retry) {
2164                 task->tk_garb_retry--;
2165                 dprintk("RPC: %5u %s: retrying\n",
2166                                 task->tk_pid, __func__);
2167                 task->tk_action = call_bind;
2168 out_retry:
2169                 return ERR_PTR(-EAGAIN);
2170         }
2171 out_eio:
2172         error = -EIO;
2173 out_err:
2174         rpc_exit(task, error);
2175         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2176                         __func__, error);
2177         return ERR_PTR(error);
2178 out_overflow:
2179         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2180                         __func__);
2181         goto out_garbage;
2182 }
2183
2184 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2185 {
2186 }
2187
2188 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2189 {
2190         return 0;
2191 }
2192
2193 static struct rpc_procinfo rpcproc_null = {
2194         .p_encode = rpcproc_encode_null,
2195         .p_decode = rpcproc_decode_null,
2196 };
2197
2198 static int rpc_ping(struct rpc_clnt *clnt)
2199 {
2200         struct rpc_message msg = {
2201                 .rpc_proc = &rpcproc_null,
2202         };
2203         int err;
2204         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2205         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2206         put_rpccred(msg.rpc_cred);
2207         return err;
2208 }
2209
2210 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2211 {
2212         struct rpc_message msg = {
2213                 .rpc_proc = &rpcproc_null,
2214                 .rpc_cred = cred,
2215         };
2216         struct rpc_task_setup task_setup_data = {
2217                 .rpc_client = clnt,
2218                 .rpc_message = &msg,
2219                 .callback_ops = &rpc_default_ops,
2220                 .flags = flags,
2221         };
2222         return rpc_run_task(&task_setup_data);
2223 }
2224 EXPORT_SYMBOL_GPL(rpc_call_null);
2225
2226 #ifdef RPC_DEBUG
2227 static void rpc_show_header(void)
2228 {
2229         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2230                 "-timeout ---ops--\n");
2231 }
2232
2233 static void rpc_show_task(const struct rpc_clnt *clnt,
2234                           const struct rpc_task *task)
2235 {
2236         const char *rpc_waitq = "none";
2237
2238         if (RPC_IS_QUEUED(task))
2239                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2240
2241         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2242                 task->tk_pid, task->tk_flags, task->tk_status,
2243                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2244                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2245                 task->tk_action, rpc_waitq);
2246 }
2247
2248 void rpc_show_tasks(struct net *net)
2249 {
2250         struct rpc_clnt *clnt;
2251         struct rpc_task *task;
2252         int header = 0;
2253         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2254
2255         spin_lock(&sn->rpc_client_lock);
2256         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2257                 spin_lock(&clnt->cl_lock);
2258                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2259                         if (!header) {
2260                                 rpc_show_header();
2261                                 header++;
2262                         }
2263                         rpc_show_task(clnt, task);
2264                 }
2265                 spin_unlock(&clnt->cl_lock);
2266         }
2267         spin_unlock(&sn->rpc_client_lock);
2268 }
2269 #endif