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                         break;
 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_clnt *clnt;
 707         const struct rpc_version *version;
 708         int err;
 709
 710         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 711         version = program->version[vers];
 712         clnt = rpc_clone_client(old);
 713         if (IS_ERR(clnt))
 714                 goto out;
 715         clnt->cl_procinfo = version->procs;
 716         clnt->cl_maxproc  = version->nrprocs;
 717         clnt->cl_protname = program->name;
 718         clnt->cl_prog     = program->number;
 719         clnt->cl_vers     = version->number;
 720         clnt->cl_stats    = program->stats;
 721         err = rpc_ping(clnt);
 722         if (err != 0) {
 723                 rpc_shutdown_client(clnt);
 724                 clnt = ERR_PTR(err);
 725         }
 726 out:
 727         return clnt;
 728 }
 729 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 730
 731 void rpc_task_release_client(struct rpc_task *task)
 732 {
 733         struct rpc_clnt *clnt = task->tk_client;
 734
 735         if (clnt != NULL) {
 736                 /* Remove from client task list */
 737                 spin_lock(&clnt->cl_lock);
 738                 list_del(&task->tk_task);
 739                 spin_unlock(&clnt->cl_lock);
 740                 task->tk_client = NULL;
 741
 742                 rpc_release_client(clnt);
 743         }
 744 }
 745
 746 static
 747 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 748 {
 749         if (clnt != NULL) {
 750                 rpc_task_release_client(task);
 751                 task->tk_client = clnt;
 752                 atomic_inc(&clnt->cl_count);
 753                 if (clnt->cl_softrtry)
 754                         task->tk_flags |= RPC_TASK_SOFT;
 755                 if (sk_memalloc_socks()) {
 756                         struct rpc_xprt *xprt;
 757
 758                         rcu_read_lock();
 759                         xprt = rcu_dereference(clnt->cl_xprt);
 760                         if (xprt->swapper)
 761                                 task->tk_flags |= RPC_TASK_SWAPPER;
 762                         rcu_read_unlock();
 763                 }
 764                 /* Add to the client's list of all tasks */
 765                 spin_lock(&clnt->cl_lock);
 766                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 767                 spin_unlock(&clnt->cl_lock);
 768         }
 769 }
 770
 771 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 772 {
 773         rpc_task_release_client(task);
 774         rpc_task_set_client(task, clnt);
 775 }
 776 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 777
 778
 779 static void
 780 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 781 {
 782         if (msg != NULL) {
 783                 task->tk_msg.rpc_proc = msg->rpc_proc;
 784                 task->tk_msg.rpc_argp = msg->rpc_argp;
 785                 task->tk_msg.rpc_resp = msg->rpc_resp;
 786                 if (msg->rpc_cred != NULL)
 787                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 788         }
 789 }
 790
 791 /*
 792  * Default callback for async RPC calls
 793  */
 794 static void
 795 rpc_default_callback(struct rpc_task *task, void *data)
 796 {
 797 }
 798
 799 static const struct rpc_call_ops rpc_default_ops = {
 800         .rpc_call_done = rpc_default_callback,
 801 };
 802
 803 /**
 804  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 805  * @task_setup_data: pointer to task initialisation data
 806  */
 807 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 808 {
 809         struct rpc_task *task;
 810
 811         task = rpc_new_task(task_setup_data);
 812         if (IS_ERR(task))
 813                 goto out;
 814
 815         rpc_task_set_client(task, task_setup_data->rpc_client);
 816         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 817
 818         if (task->tk_action == NULL)
 819                 rpc_call_start(task);
 820
 821         atomic_inc(&task->tk_count);
 822         rpc_execute(task);
 823 out:
 824         return task;
 825 }
 826 EXPORT_SYMBOL_GPL(rpc_run_task);
 827
 828 /**
 829  * rpc_call_sync - Perform a synchronous RPC call
 830  * @clnt: pointer to RPC client
 831  * @msg: RPC call parameters
 832  * @flags: RPC call flags
 833  */
 834 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 835 {
 836         struct rpc_task *task;
 837         struct rpc_task_setup task_setup_data = {
 838                 .rpc_client = clnt,
 839                 .rpc_message = msg,
 840                 .callback_ops = &rpc_default_ops,
 841                 .flags = flags,
 842         };
 843         int status;
 844
 845         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 846         if (flags & RPC_TASK_ASYNC) {
 847                 rpc_release_calldata(task_setup_data.callback_ops,
 848                         task_setup_data.callback_data);
 849                 return -EINVAL;
 850         }
 851
 852         task = rpc_run_task(&task_setup_data);
 853         if (IS_ERR(task))
 854                 return PTR_ERR(task);
 855         status = task->tk_status;
 856         rpc_put_task(task);
 857         return status;
 858 }
 859 EXPORT_SYMBOL_GPL(rpc_call_sync);
 860
 861 /**
 862  * rpc_call_async - Perform an asynchronous RPC call
 863  * @clnt: pointer to RPC client
 864  * @msg: RPC call parameters
 865  * @flags: RPC call flags
 866  * @tk_ops: RPC call ops
 867  * @data: user call data
 868  */
 869 int
 870 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 871                const struct rpc_call_ops *tk_ops, void *data)
 872 {
 873         struct rpc_task *task;
 874         struct rpc_task_setup task_setup_data = {
 875                 .rpc_client = clnt,
 876                 .rpc_message = msg,
 877                 .callback_ops = tk_ops,
 878                 .callback_data = data,
 879                 .flags = flags|RPC_TASK_ASYNC,
 880         };
 881
 882         task = rpc_run_task(&task_setup_data);
 883         if (IS_ERR(task))
 884                 return PTR_ERR(task);
 885         rpc_put_task(task);
 886         return 0;
 887 }
 888 EXPORT_SYMBOL_GPL(rpc_call_async);
 889
 890 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 891 /**
 892  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 893  * rpc_execute against it
 894  * @req: RPC request
 895  * @tk_ops: RPC call ops
 896  */
 897 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 898                                 const struct rpc_call_ops *tk_ops)
 899 {
 900         struct rpc_task *task;
 901         struct xdr_buf *xbufp = &req->rq_snd_buf;
 902         struct rpc_task_setup task_setup_data = {
 903                 .callback_ops = tk_ops,
 904         };
 905
 906         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 907         /*
 908          * Create an rpc_task to send the data
 909          */
 910         task = rpc_new_task(&task_setup_data);
 911         if (IS_ERR(task)) {
 912                 xprt_free_bc_request(req);
 913                 goto out;
 914         }
 915         task->tk_rqstp = req;
 916
 917         /*
 918          * Set up the xdr_buf length.
 919          * This also indicates that the buffer is XDR encoded already.
 920          */
 921         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 922                         xbufp->tail[0].iov_len;
 923
 924         task->tk_action = call_bc_transmit;
 925         atomic_inc(&task->tk_count);
 926         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 927         rpc_execute(task);
 928
 929 out:
 930         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 931         return task;
 932 }
 933 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 934
 935 void
 936 rpc_call_start(struct rpc_task *task)
 937 {
 938         task->tk_action = call_start;
 939 }
 940 EXPORT_SYMBOL_GPL(rpc_call_start);
 941
 942 /**
 943  * rpc_peeraddr - extract remote peer address from clnt's xprt
 944  * @clnt: RPC client structure
 945  * @buf: target buffer
 946  * @bufsize: length of target buffer
 947  *
 948  * Returns the number of bytes that are actually in the stored address.
 949  */
 950 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 951 {
 952         size_t bytes;
 953         struct rpc_xprt *xprt;
 954
 955         rcu_read_lock();
 956         xprt = rcu_dereference(clnt->cl_xprt);
 957
 958         bytes = xprt->addrlen;
 959         if (bytes > bufsize)
 960                 bytes = bufsize;
 961         memcpy(buf, &xprt->addr, bytes);
 962         rcu_read_unlock();
 963
 964         return bytes;
 965 }
 966 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 967
 968 /**
 969  * rpc_peeraddr2str - return remote peer address in printable format
 970  * @clnt: RPC client structure
 971  * @format: address format
 972  *
 973  * NB: the lifetime of the memory referenced by the returned pointer is
 974  * the same as the rpc_xprt itself.  As long as the caller uses this
 975  * pointer, it must hold the RCU read lock.
 976  */
 977 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 978                              enum rpc_display_format_t format)
 979 {
 980         struct rpc_xprt *xprt;
 981
 982         xprt = rcu_dereference(clnt->cl_xprt);
 983
 984         if (xprt->address_strings[format] != NULL)
 985                 return xprt->address_strings[format];
 986         else
 987                 return "unprintable";
 988 }
 989 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 990
 991 static const struct sockaddr_in rpc_inaddr_loopback = {
 992         .sin_family             = AF_INET,
 993         .sin_addr.s_addr        = htonl(INADDR_ANY),
 994 };
 995
 996 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 997         .sin6_family            = AF_INET6,
 998         .sin6_addr              = IN6ADDR_ANY_INIT,
 999 };
1000
1001 /*
1002  * Try a getsockname() on a connected datagram socket.  Using a
1003  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1004  * This conserves the ephemeral port number space.
1005  *
1006  * Returns zero and fills in "buf" if successful; otherwise, a
1007  * negative errno is returned.
1008  */
1009 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1010                         struct sockaddr *buf, int buflen)
1011 {
1012         struct socket *sock;
1013         int err;
1014
1015         err = __sock_create(net, sap->sa_family,
1016                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1017         if (err < 0) {
1018                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1019                 goto out;
1020         }
1021
1022         switch (sap->sa_family) {
1023         case AF_INET:
1024                 err = kernel_bind(sock,
1025                                 (struct sockaddr *)&rpc_inaddr_loopback,
1026                                 sizeof(rpc_inaddr_loopback));
1027                 break;
1028         case AF_INET6:
1029                 err = kernel_bind(sock,
1030                                 (struct sockaddr *)&rpc_in6addr_loopback,
1031                                 sizeof(rpc_in6addr_loopback));
1032                 break;
1033         default:
1034                 err = -EAFNOSUPPORT;
1035                 goto out;
1036         }
1037         if (err < 0) {
1038                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1039                 goto out_release;
1040         }
1041
1042         err = kernel_connect(sock, sap, salen, 0);
1043         if (err < 0) {
1044                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1045                 goto out_release;
1046         }
1047
1048         err = kernel_getsockname(sock, buf, &buflen);
1049         if (err < 0) {
1050                 dprintk("RPC:       getsockname failed (%d)\n", err);
1051                 goto out_release;
1052         }
1053
1054         err = 0;
1055         if (buf->sa_family == AF_INET6) {
1056                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1057                 sin6->sin6_scope_id = 0;
1058         }
1059         dprintk("RPC:       %s succeeded\n", __func__);
1060
1061 out_release:
1062         sock_release(sock);
1063 out:
1064         return err;
1065 }
1066
1067 /*
1068  * Scraping a connected socket failed, so we don't have a useable
1069  * local address.  Fallback: generate an address that will prevent
1070  * the server from calling us back.
1071  *
1072  * Returns zero and fills in "buf" if successful; otherwise, a
1073  * negative errno is returned.
1074  */
1075 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1076 {
1077         switch (family) {
1078         case AF_INET:
1079                 if (buflen < sizeof(rpc_inaddr_loopback))
1080                         return -EINVAL;
1081                 memcpy(buf, &rpc_inaddr_loopback,
1082                                 sizeof(rpc_inaddr_loopback));
1083                 break;
1084         case AF_INET6:
1085                 if (buflen < sizeof(rpc_in6addr_loopback))
1086                         return -EINVAL;
1087                 memcpy(buf, &rpc_in6addr_loopback,
1088                                 sizeof(rpc_in6addr_loopback));
1089         default:
1090                 dprintk("RPC:       %s: address family not supported\n",
1091                         __func__);
1092                 return -EAFNOSUPPORT;
1093         }
1094         dprintk("RPC:       %s: succeeded\n", __func__);
1095         return 0;
1096 }
1097
1098 /**
1099  * rpc_localaddr - discover local endpoint address for an RPC client
1100  * @clnt: RPC client structure
1101  * @buf: target buffer
1102  * @buflen: size of target buffer, in bytes
1103  *
1104  * Returns zero and fills in "buf" and "buflen" if successful;
1105  * otherwise, a negative errno is returned.
1106  *
1107  * This works even if the underlying transport is not currently connected,
1108  * or if the upper layer never previously provided a source address.
1109  *
1110  * The result of this function call is transient: multiple calls in
1111  * succession may give different results, depending on how local
1112  * networking configuration changes over time.
1113  */
1114 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1115 {
1116         struct sockaddr_storage address;
1117         struct sockaddr *sap = (struct sockaddr *)&address;
1118         struct rpc_xprt *xprt;
1119         struct net *net;
1120         size_t salen;
1121         int err;
1122
1123         rcu_read_lock();
1124         xprt = rcu_dereference(clnt->cl_xprt);
1125         salen = xprt->addrlen;
1126         memcpy(sap, &xprt->addr, salen);
1127         net = get_net(xprt->xprt_net);
1128         rcu_read_unlock();
1129
1130         rpc_set_port(sap, 0);
1131         err = rpc_sockname(net, sap, salen, buf, buflen);
1132         put_net(net);
1133         if (err != 0)
1134                 /* Couldn't discover local address, return ANYADDR */
1135                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1136         return 0;
1137 }
1138 EXPORT_SYMBOL_GPL(rpc_localaddr);
1139
1140 void
1141 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1142 {
1143         struct rpc_xprt *xprt;
1144
1145         rcu_read_lock();
1146         xprt = rcu_dereference(clnt->cl_xprt);
1147         if (xprt->ops->set_buffer_size)
1148                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1149         rcu_read_unlock();
1150 }
1151 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1152
1153 /**
1154  * rpc_protocol - Get transport protocol number for an RPC client
1155  * @clnt: RPC client to query
1156  *
1157  */
1158 int rpc_protocol(struct rpc_clnt *clnt)
1159 {
1160         int protocol;
1161
1162         rcu_read_lock();
1163         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1164         rcu_read_unlock();
1165         return protocol;
1166 }
1167 EXPORT_SYMBOL_GPL(rpc_protocol);
1168
1169 /**
1170  * rpc_net_ns - Get the network namespace for this RPC client
1171  * @clnt: RPC client to query
1172  *
1173  */
1174 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1175 {
1176         struct net *ret;
1177
1178         rcu_read_lock();
1179         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1180         rcu_read_unlock();
1181         return ret;
1182 }
1183 EXPORT_SYMBOL_GPL(rpc_net_ns);
1184
1185 /**
1186  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1187  * @clnt: RPC client to query
1188  *
1189  * For stream transports, this is one RPC record fragment (see RFC
1190  * 1831), as we don't support multi-record requests yet.  For datagram
1191  * transports, this is the size of an IP packet minus the IP, UDP, and
1192  * RPC header sizes.
1193  */
1194 size_t rpc_max_payload(struct rpc_clnt *clnt)
1195 {
1196         size_t ret;
1197
1198         rcu_read_lock();
1199         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1200         rcu_read_unlock();
1201         return ret;
1202 }
1203 EXPORT_SYMBOL_GPL(rpc_max_payload);
1204
1205 /**
1206  * rpc_force_rebind - force transport to check that remote port is unchanged
1207  * @clnt: client to rebind
1208  *
1209  */
1210 void rpc_force_rebind(struct rpc_clnt *clnt)
1211 {
1212         if (clnt->cl_autobind) {
1213                 rcu_read_lock();
1214                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1215                 rcu_read_unlock();
1216         }
1217 }
1218 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1219
1220 /*
1221  * Restart an (async) RPC call from the call_prepare state.
1222  * Usually called from within the exit handler.
1223  */
1224 int
1225 rpc_restart_call_prepare(struct rpc_task *task)
1226 {
1227         if (RPC_ASSASSINATED(task))
1228                 return 0;
1229         task->tk_action = call_start;
1230         if (task->tk_ops->rpc_call_prepare != NULL)
1231                 task->tk_action = rpc_prepare_task;
1232         return 1;
1233 }
1234 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1235
1236 /*
1237  * Restart an (async) RPC call. Usually called from within the
1238  * exit handler.
1239  */
1240 int
1241 rpc_restart_call(struct rpc_task *task)
1242 {
1243         if (RPC_ASSASSINATED(task))
1244                 return 0;
1245         task->tk_action = call_start;
1246         return 1;
1247 }
1248 EXPORT_SYMBOL_GPL(rpc_restart_call);
1249
1250 #ifdef RPC_DEBUG
1251 static const char *rpc_proc_name(const struct rpc_task *task)
1252 {
1253         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1254
1255         if (proc) {
1256                 if (proc->p_name)
1257                         return proc->p_name;
1258                 else
1259                         return "NULL";
1260         } else
1261                 return "no proc";
1262 }
1263 #endif
1264
1265 /*
1266  * 0.  Initial state
1267  *
1268  *     Other FSM states can be visited zero or more times, but
1269  *     this state is visited exactly once for each RPC.
1270  */
1271 static void
1272 call_start(struct rpc_task *task)
1273 {
1274         struct rpc_clnt *clnt = task->tk_client;
1275
1276         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1277                         clnt->cl_protname, clnt->cl_vers,
1278                         rpc_proc_name(task),
1279                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1280
1281         /* Increment call count */
1282         task->tk_msg.rpc_proc->p_count++;
1283         clnt->cl_stats->rpccnt++;
1284         task->tk_action = call_reserve;
1285 }
1286
1287 /*
1288  * 1.   Reserve an RPC call slot
1289  */
1290 static void
1291 call_reserve(struct rpc_task *task)
1292 {
1293         dprint_status(task);
1294
1295         task->tk_status  = 0;
1296         task->tk_action  = call_reserveresult;
1297         xprt_reserve(task);
1298 }
1299
1300 /*
1301  * 1b.  Grok the result of xprt_reserve()
1302  */
1303 static void
1304 call_reserveresult(struct rpc_task *task)
1305 {
1306         int status = task->tk_status;
1307
1308         dprint_status(task);
1309
1310         /*
1311          * After a call to xprt_reserve(), we must have either
1312          * a request slot or else an error status.
1313          */
1314         task->tk_status = 0;
1315         if (status >= 0) {
1316                 if (task->tk_rqstp) {
1317                         task->tk_action = call_refresh;
1318                         return;
1319                 }
1320
1321                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1322                                 __func__, status);
1323                 rpc_exit(task, -EIO);
1324                 return;
1325         }
1326
1327         /*
1328          * Even though there was an error, we may have acquired
1329          * a request slot somehow.  Make sure not to leak it.
1330          */
1331         if (task->tk_rqstp) {
1332                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1333                                 __func__, status);
1334                 xprt_release(task);
1335         }
1336
1337         switch (status) {
1338         case -ENOMEM:
1339                 rpc_delay(task, HZ >> 2);
1340         case -EAGAIN:   /* woken up; retry */
1341                 task->tk_action = call_reserve;
1342                 return;
1343         case -EIO:      /* probably a shutdown */
1344                 break;
1345         default:
1346                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1347                                 __func__, status);
1348                 break;
1349         }
1350         rpc_exit(task, status);
1351 }
1352
1353 /*
1354  * 2.   Bind and/or refresh the credentials
1355  */
1356 static void
1357 call_refresh(struct rpc_task *task)
1358 {
1359         dprint_status(task);
1360
1361         task->tk_action = call_refreshresult;
1362         task->tk_status = 0;
1363         task->tk_client->cl_stats->rpcauthrefresh++;
1364         rpcauth_refreshcred(task);
1365 }
1366
1367 /*
1368  * 2a.  Process the results of a credential refresh
1369  */
1370 static void
1371 call_refreshresult(struct rpc_task *task)
1372 {
1373         int status = task->tk_status;
1374
1375         dprint_status(task);
1376
1377         task->tk_status = 0;
1378         task->tk_action = call_refresh;
1379         switch (status) {
1380         case 0:
1381                 if (rpcauth_uptodatecred(task))
1382                         task->tk_action = call_allocate;
1383                 return;
1384         case -ETIMEDOUT:
1385                 rpc_delay(task, 3*HZ);
1386         case -EAGAIN:
1387                 status = -EACCES;
1388                 if (!task->tk_cred_retry)
1389                         break;
1390                 task->tk_cred_retry--;
1391                 dprintk("RPC: %5u %s: retry refresh creds\n",
1392                                 task->tk_pid, __func__);
1393                 return;
1394         }
1395         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1396                                 task->tk_pid, __func__, status);
1397         rpc_exit(task, status);
1398 }
1399
1400 /*
1401  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1402  *      (Note: buffer memory is freed in xprt_release).
1403  */
1404 static void
1405 call_allocate(struct rpc_task *task)
1406 {
1407         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1408         struct rpc_rqst *req = task->tk_rqstp;
1409         struct rpc_xprt *xprt = task->tk_xprt;
1410         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1411
1412         dprint_status(task);
1413
1414         task->tk_status = 0;
1415         task->tk_action = call_bind;
1416
1417         if (req->rq_buffer)
1418                 return;
1419
1420         if (proc->p_proc != 0) {
1421                 BUG_ON(proc->p_arglen == 0);
1422                 if (proc->p_decode != NULL)
1423                         BUG_ON(proc->p_replen == 0);
1424         }
1425
1426         /*
1427          * Calculate the size (in quads) of the RPC call
1428          * and reply headers, and convert both values
1429          * to byte sizes.
1430          */
1431         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1432         req->rq_callsize <<= 2;
1433         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1434         req->rq_rcvsize <<= 2;
1435
1436         req->rq_buffer = xprt->ops->buf_alloc(task,
1437                                         req->rq_callsize + req->rq_rcvsize);
1438         if (req->rq_buffer != NULL)
1439                 return;
1440
1441         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1442
1443         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1444                 task->tk_action = call_allocate;
1445                 rpc_delay(task, HZ>>4);
1446                 return;
1447         }
1448
1449         rpc_exit(task, -ERESTARTSYS);
1450 }
1451
1452 static inline int
1453 rpc_task_need_encode(struct rpc_task *task)
1454 {
1455         return task->tk_rqstp->rq_snd_buf.len == 0;
1456 }
1457
1458 static inline void
1459 rpc_task_force_reencode(struct rpc_task *task)
1460 {
1461         task->tk_rqstp->rq_snd_buf.len = 0;
1462         task->tk_rqstp->rq_bytes_sent = 0;
1463 }
1464
1465 static inline void
1466 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1467 {
1468         buf->head[0].iov_base = start;
1469         buf->head[0].iov_len = len;
1470         buf->tail[0].iov_len = 0;
1471         buf->page_len = 0;
1472         buf->flags = 0;
1473         buf->len = 0;
1474         buf->buflen = len;
1475 }
1476
1477 /*
1478  * 3.   Encode arguments of an RPC call
1479  */
1480 static void
1481 rpc_xdr_encode(struct rpc_task *task)
1482 {
1483         struct rpc_rqst *req = task->tk_rqstp;
1484         kxdreproc_t     encode;
1485         __be32          *p;
1486
1487         dprint_status(task);
1488
1489         rpc_xdr_buf_init(&req->rq_snd_buf,
1490                          req->rq_buffer,
1491                          req->rq_callsize);
1492         rpc_xdr_buf_init(&req->rq_rcv_buf,
1493                          (char *)req->rq_buffer + req->rq_callsize,
1494                          req->rq_rcvsize);
1495
1496         p = rpc_encode_header(task);
1497         if (p == NULL) {
1498                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1499                 rpc_exit(task, -EIO);
1500                 return;
1501         }
1502
1503         encode = task->tk_msg.rpc_proc->p_encode;
1504         if (encode == NULL)
1505                 return;
1506
1507         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1508                         task->tk_msg.rpc_argp);
1509 }
1510
1511 /*
1512  * 4.   Get the server port number if not yet set
1513  */
1514 static void
1515 call_bind(struct rpc_task *task)
1516 {
1517         struct rpc_xprt *xprt = task->tk_xprt;
1518
1519         dprint_status(task);
1520
1521         task->tk_action = call_connect;
1522         if (!xprt_bound(xprt)) {
1523                 task->tk_action = call_bind_status;
1524                 task->tk_timeout = xprt->bind_timeout;
1525                 xprt->ops->rpcbind(task);
1526         }
1527 }
1528
1529 /*
1530  * 4a.  Sort out bind result
1531  */
1532 static void
1533 call_bind_status(struct rpc_task *task)
1534 {
1535         int status = -EIO;
1536
1537         if (task->tk_status >= 0) {
1538                 dprint_status(task);
1539                 task->tk_status = 0;
1540                 task->tk_action = call_connect;
1541                 return;
1542         }
1543
1544         trace_rpc_bind_status(task);
1545         switch (task->tk_status) {
1546         case -ENOMEM:
1547                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1548                 rpc_delay(task, HZ >> 2);
1549                 goto retry_timeout;
1550         case -EACCES:
1551                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1552                                 "unavailable\n", task->tk_pid);
1553                 /* fail immediately if this is an RPC ping */
1554                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1555                         status = -EOPNOTSUPP;
1556                         break;
1557                 }
1558                 if (task->tk_rebind_retry == 0)
1559                         break;
1560                 task->tk_rebind_retry--;
1561                 rpc_delay(task, 3*HZ);
1562                 goto retry_timeout;
1563         case -ETIMEDOUT:
1564                 dprintk("RPC: %5u rpcbind request timed out\n",
1565                                 task->tk_pid);
1566                 goto retry_timeout;
1567         case -EPFNOSUPPORT:
1568                 /* server doesn't support any rpcbind version we know of */
1569                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1570                                 task->tk_pid);
1571                 break;
1572         case -EPROTONOSUPPORT:
1573                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1574                                 task->tk_pid);
1575                 task->tk_status = 0;
1576                 task->tk_action = call_bind;
1577                 return;
1578         case -ECONNREFUSED:             /* connection problems */
1579         case -ECONNRESET:
1580         case -ENOTCONN:
1581         case -EHOSTDOWN:
1582         case -EHOSTUNREACH:
1583         case -ENETUNREACH:
1584         case -EPIPE:
1585                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1586                                 task->tk_pid, task->tk_status);
1587                 if (!RPC_IS_SOFTCONN(task)) {
1588                         rpc_delay(task, 5*HZ);
1589                         goto retry_timeout;
1590                 }
1591                 status = task->tk_status;
1592                 break;
1593         default:
1594                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1595                                 task->tk_pid, -task->tk_status);
1596         }
1597
1598         rpc_exit(task, status);
1599         return;
1600
1601 retry_timeout:
1602         task->tk_action = call_timeout;
1603 }
1604
1605 /*
1606  * 4b.  Connect to the RPC server
1607  */
1608 static void
1609 call_connect(struct rpc_task *task)
1610 {
1611         struct rpc_xprt *xprt = task->tk_xprt;
1612
1613         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1614                         task->tk_pid, xprt,
1615                         (xprt_connected(xprt) ? "is" : "is not"));
1616
1617         task->tk_action = call_transmit;
1618         if (!xprt_connected(xprt)) {
1619                 task->tk_action = call_connect_status;
1620                 if (task->tk_status < 0)
1621                         return;
1622                 xprt_connect(task);
1623         }
1624 }
1625
1626 /*
1627  * 4c.  Sort out connect result
1628  */
1629 static void
1630 call_connect_status(struct rpc_task *task)
1631 {
1632         struct rpc_clnt *clnt = task->tk_client;
1633         int status = task->tk_status;
1634
1635         dprint_status(task);
1636
1637         task->tk_status = 0;
1638         if (status >= 0 || status == -EAGAIN) {
1639                 clnt->cl_stats->netreconn++;
1640                 task->tk_action = call_transmit;
1641                 return;
1642         }
1643
1644         trace_rpc_connect_status(task, status);
1645         switch (status) {
1646                 /* if soft mounted, test if we've timed out */
1647         case -ETIMEDOUT:
1648                 task->tk_action = call_timeout;
1649                 break;
1650         default:
1651                 rpc_exit(task, -EIO);
1652         }
1653 }
1654
1655 /*
1656  * 5.   Transmit the RPC request, and wait for reply
1657  */
1658 static void
1659 call_transmit(struct rpc_task *task)
1660 {
1661         dprint_status(task);
1662
1663         task->tk_action = call_status;
1664         if (task->tk_status < 0)
1665                 return;
1666         task->tk_status = xprt_prepare_transmit(task);
1667         if (task->tk_status != 0)
1668                 return;
1669         task->tk_action = call_transmit_status;
1670         /* Encode here so that rpcsec_gss can use correct sequence number. */
1671         if (rpc_task_need_encode(task)) {
1672                 rpc_xdr_encode(task);
1673                 /* Did the encode result in an error condition? */
1674                 if (task->tk_status != 0) {
1675                         /* Was the error nonfatal? */
1676                         if (task->tk_status == -EAGAIN)
1677                                 rpc_delay(task, HZ >> 4);
1678                         else
1679                                 rpc_exit(task, task->tk_status);
1680                         return;
1681                 }
1682         }
1683         xprt_transmit(task);
1684         if (task->tk_status < 0)
1685                 return;
1686         /*
1687          * On success, ensure that we call xprt_end_transmit() before sleeping
1688          * in order to allow access to the socket to other RPC requests.
1689          */
1690         call_transmit_status(task);
1691         if (rpc_reply_expected(task))
1692                 return;
1693         task->tk_action = rpc_exit_task;
1694         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1695 }
1696
1697 /*
1698  * 5a.  Handle cleanup after a transmission
1699  */
1700 static void
1701 call_transmit_status(struct rpc_task *task)
1702 {
1703         task->tk_action = call_status;
1704
1705         /*
1706          * Common case: success.  Force the compiler to put this
1707          * test first.
1708          */
1709         if (task->tk_status == 0) {
1710                 xprt_end_transmit(task);
1711                 rpc_task_force_reencode(task);
1712                 return;
1713         }
1714
1715         switch (task->tk_status) {
1716         case -EAGAIN:
1717                 break;
1718         default:
1719                 dprint_status(task);
1720                 xprt_end_transmit(task);
1721                 rpc_task_force_reencode(task);
1722                 break;
1723                 /*
1724                  * Special cases: if we've been waiting on the
1725                  * socket's write_space() callback, or if the
1726                  * socket just returned a connection error,
1727                  * then hold onto the transport lock.
1728                  */
1729         case -ECONNREFUSED:
1730         case -EHOSTDOWN:
1731         case -EHOSTUNREACH:
1732         case -ENETUNREACH:
1733                 if (RPC_IS_SOFTCONN(task)) {
1734                         xprt_end_transmit(task);
1735                         rpc_exit(task, task->tk_status);
1736                         break;
1737                 }
1738         case -ECONNRESET:
1739         case -ENOTCONN:
1740         case -EPIPE:
1741                 rpc_task_force_reencode(task);
1742         }
1743 }
1744
1745 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1746 /*
1747  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1748  * addition, disconnect on connectivity errors.
1749  */
1750 static void
1751 call_bc_transmit(struct rpc_task *task)
1752 {
1753         struct rpc_rqst *req = task->tk_rqstp;
1754
1755         task->tk_status = xprt_prepare_transmit(task);
1756         if (task->tk_status == -EAGAIN) {
1757                 /*
1758                  * Could not reserve the transport. Try again after the
1759                  * transport is released.
1760                  */
1761                 task->tk_status = 0;
1762                 task->tk_action = call_bc_transmit;
1763                 return;
1764         }
1765
1766         task->tk_action = rpc_exit_task;
1767         if (task->tk_status < 0) {
1768                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1769                         "error: %d\n", task->tk_status);
1770                 return;
1771         }
1772
1773         xprt_transmit(task);
1774         xprt_end_transmit(task);
1775         dprint_status(task);
1776         switch (task->tk_status) {
1777         case 0:
1778                 /* Success */
1779                 break;
1780         case -EHOSTDOWN:
1781         case -EHOSTUNREACH:
1782         case -ENETUNREACH:
1783         case -ETIMEDOUT:
1784                 /*
1785                  * Problem reaching the server.  Disconnect and let the
1786                  * forechannel reestablish the connection.  The server will
1787                  * have to retransmit the backchannel request and we'll
1788                  * reprocess it.  Since these ops are idempotent, there's no
1789                  * need to cache our reply at this time.
1790                  */
1791                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1792                         "error: %d\n", task->tk_status);
1793                 xprt_conditional_disconnect(task->tk_xprt,
1794                         req->rq_connect_cookie);
1795                 break;
1796         default:
1797                 /*
1798                  * We were unable to reply and will have to drop the
1799                  * request.  The server should reconnect and retransmit.
1800                  */
1801                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1802                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1803                         "error: %d\n", task->tk_status);
1804                 break;
1805         }
1806         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1807 }
1808 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1809
1810 /*
1811  * 6.   Sort out the RPC call status
1812  */
1813 static void
1814 call_status(struct rpc_task *task)
1815 {
1816         struct rpc_clnt *clnt = task->tk_client;
1817         struct rpc_rqst *req = task->tk_rqstp;
1818         int             status;
1819
1820         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1821                 task->tk_status = req->rq_reply_bytes_recvd;
1822
1823         dprint_status(task);
1824
1825         status = task->tk_status;
1826         if (status >= 0) {
1827                 task->tk_action = call_decode;
1828                 return;
1829         }
1830
1831         trace_rpc_call_status(task);
1832         task->tk_status = 0;
1833         switch(status) {
1834         case -EHOSTDOWN:
1835         case -EHOSTUNREACH:
1836         case -ENETUNREACH:
1837                 /*
1838                  * Delay any retries for 3 seconds, then handle as if it
1839                  * were a timeout.
1840                  */
1841                 rpc_delay(task, 3*HZ);
1842         case -ETIMEDOUT:
1843                 task->tk_action = call_timeout;
1844                 if (task->tk_client->cl_discrtry)
1845                         xprt_conditional_disconnect(task->tk_xprt,
1846                                         req->rq_connect_cookie);
1847                 break;
1848         case -ECONNRESET:
1849         case -ECONNREFUSED:
1850                 rpc_force_rebind(clnt);
1851                 rpc_delay(task, 3*HZ);
1852         case -EPIPE:
1853         case -ENOTCONN:
1854                 task->tk_action = call_bind;
1855                 break;
1856         case -EAGAIN:
1857                 task->tk_action = call_transmit;
1858                 break;
1859         case -EIO:
1860                 /* shutdown or soft timeout */
1861                 rpc_exit(task, status);
1862                 break;
1863         default:
1864                 if (clnt->cl_chatty)
1865                         printk("%s: RPC call returned error %d\n",
1866                                clnt->cl_protname, -status);
1867                 rpc_exit(task, status);
1868         }
1869 }
1870
1871 /*
1872  * 6a.  Handle RPC timeout
1873  *      We do not release the request slot, so we keep using the
1874  *      same XID for all retransmits.
1875  */
1876 static void
1877 call_timeout(struct rpc_task *task)
1878 {
1879         struct rpc_clnt *clnt = task->tk_client;
1880
1881         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1882                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1883                 goto retry;
1884         }
1885
1886         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1887         task->tk_timeouts++;
1888
1889         if (RPC_IS_SOFTCONN(task)) {
1890                 rpc_exit(task, -ETIMEDOUT);
1891                 return;
1892         }
1893         if (RPC_IS_SOFT(task)) {
1894                 if (clnt->cl_chatty) {
1895                         rcu_read_lock();
1896                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1897                                 clnt->cl_protname,
1898                                 rcu_dereference(clnt->cl_xprt)->servername);
1899                         rcu_read_unlock();
1900                 }
1901                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1902                         rpc_exit(task, -ETIMEDOUT);
1903                 else
1904                         rpc_exit(task, -EIO);
1905                 return;
1906         }
1907
1908         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1909                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1910                 if (clnt->cl_chatty) {
1911                         rcu_read_lock();
1912                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1913                         clnt->cl_protname,
1914                         rcu_dereference(clnt->cl_xprt)->servername);
1915                         rcu_read_unlock();
1916                 }
1917         }
1918         rpc_force_rebind(clnt);
1919         /*
1920          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1921          * event? RFC2203 requires the server to drop all such requests.
1922          */
1923         rpcauth_invalcred(task);
1924
1925 retry:
1926         clnt->cl_stats->rpcretrans++;
1927         task->tk_action = call_bind;
1928         task->tk_status = 0;
1929 }
1930
1931 /*
1932  * 7.   Decode the RPC reply
1933  */
1934 static void
1935 call_decode(struct rpc_task *task)
1936 {
1937         struct rpc_clnt *clnt = task->tk_client;
1938         struct rpc_rqst *req = task->tk_rqstp;
1939         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1940         __be32          *p;
1941
1942         dprint_status(task);
1943
1944         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1945                 if (clnt->cl_chatty) {
1946                         rcu_read_lock();
1947                         printk(KERN_NOTICE "%s: server %s OK\n",
1948                                 clnt->cl_protname,
1949                                 rcu_dereference(clnt->cl_xprt)->servername);
1950                         rcu_read_unlock();
1951                 }
1952                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1953         }
1954
1955         /*
1956          * Ensure that we see all writes made by xprt_complete_rqst()
1957          * before it changed req->rq_reply_bytes_recvd.
1958          */
1959         smp_rmb();
1960         req->rq_rcv_buf.len = req->rq_private_buf.len;
1961
1962         /* Check that the softirq receive buffer is valid */
1963         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1964                                 sizeof(req->rq_rcv_buf)) != 0);
1965
1966         if (req->rq_rcv_buf.len < 12) {
1967                 if (!RPC_IS_SOFT(task)) {
1968                         task->tk_action = call_bind;
1969                         clnt->cl_stats->rpcretrans++;
1970                         goto out_retry;
1971                 }
1972                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1973                                 clnt->cl_protname, task->tk_status);
1974                 task->tk_action = call_timeout;
1975                 goto out_retry;
1976         }
1977
1978         p = rpc_verify_header(task);
1979         if (IS_ERR(p)) {
1980                 if (p == ERR_PTR(-EAGAIN))
1981                         goto out_retry;
1982                 return;
1983         }
1984
1985         task->tk_action = rpc_exit_task;
1986
1987         if (decode) {
1988                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1989                                                       task->tk_msg.rpc_resp);
1990         }
1991         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1992                         task->tk_status);
1993         return;
1994 out_retry:
1995         task->tk_status = 0;
1996         /* Note: rpc_verify_header() may have freed the RPC slot */
1997         if (task->tk_rqstp == req) {
1998                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1999                 if (task->tk_client->cl_discrtry)
2000                         xprt_conditional_disconnect(task->tk_xprt,
2001                                         req->rq_connect_cookie);
2002         }
2003 }
2004
2005 static __be32 *
2006 rpc_encode_header(struct rpc_task *task)
2007 {
2008         struct rpc_clnt *clnt = task->tk_client;
2009         struct rpc_rqst *req = task->tk_rqstp;
2010         __be32          *p = req->rq_svec[0].iov_base;
2011
2012         /* FIXME: check buffer size? */
2013
2014         p = xprt_skip_transport_header(task->tk_xprt, p);
2015         *p++ = req->rq_xid;             /* XID */
2016         *p++ = htonl(RPC_CALL);         /* CALL */
2017         *p++ = htonl(RPC_VERSION);      /* RPC version */
2018         *p++ = htonl(clnt->cl_prog);    /* program number */
2019         *p++ = htonl(clnt->cl_vers);    /* program version */
2020         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2021         p = rpcauth_marshcred(task, p);
2022         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2023         return p;
2024 }
2025
2026 static __be32 *
2027 rpc_verify_header(struct rpc_task *task)
2028 {
2029         struct rpc_clnt *clnt = task->tk_client;
2030         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2031         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2032         __be32  *p = iov->iov_base;
2033         u32 n;
2034         int error = -EACCES;
2035
2036         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2037                 /* RFC-1014 says that the representation of XDR data must be a
2038                  * multiple of four bytes
2039                  * - if it isn't pointer subtraction in the NFS client may give
2040                  *   undefined results
2041                  */
2042                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2043                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2044                        task->tk_rqstp->rq_rcv_buf.len);
2045                 goto out_eio;
2046         }
2047         if ((len -= 3) < 0)
2048                 goto out_overflow;
2049
2050         p += 1; /* skip XID */
2051         if ((n = ntohl(*p++)) != RPC_REPLY) {
2052                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2053                         task->tk_pid, __func__, n);
2054                 goto out_garbage;
2055         }
2056
2057         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2058                 if (--len < 0)
2059                         goto out_overflow;
2060                 switch ((n = ntohl(*p++))) {
2061                 case RPC_AUTH_ERROR:
2062                         break;
2063                 case RPC_MISMATCH:
2064                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2065                                 task->tk_pid, __func__);
2066                         error = -EPROTONOSUPPORT;
2067                         goto out_err;
2068                 default:
2069                         dprintk("RPC: %5u %s: RPC call rejected, "
2070                                 "unknown error: %x\n",
2071                                 task->tk_pid, __func__, n);
2072                         goto out_eio;
2073                 }
2074                 if (--len < 0)
2075                         goto out_overflow;
2076                 switch ((n = ntohl(*p++))) {
2077                 case RPC_AUTH_REJECTEDCRED:
2078                 case RPC_AUTH_REJECTEDVERF:
2079                 case RPCSEC_GSS_CREDPROBLEM:
2080                 case RPCSEC_GSS_CTXPROBLEM:
2081                         if (!task->tk_cred_retry)
2082                                 break;
2083                         task->tk_cred_retry--;
2084                         dprintk("RPC: %5u %s: retry stale creds\n",
2085                                         task->tk_pid, __func__);
2086                         rpcauth_invalcred(task);
2087                         /* Ensure we obtain a new XID! */
2088                         xprt_release(task);
2089                         task->tk_action = call_reserve;
2090                         goto out_retry;
2091                 case RPC_AUTH_BADCRED:
2092                 case RPC_AUTH_BADVERF:
2093                         /* possibly garbled cred/verf? */
2094                         if (!task->tk_garb_retry)
2095                                 break;
2096                         task->tk_garb_retry--;
2097                         dprintk("RPC: %5u %s: retry garbled creds\n",
2098                                         task->tk_pid, __func__);
2099                         task->tk_action = call_bind;
2100                         goto out_retry;
2101                 case RPC_AUTH_TOOWEAK:
2102                         rcu_read_lock();
2103                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2104                                "authentication.\n",
2105                                rcu_dereference(clnt->cl_xprt)->servername);
2106                         rcu_read_unlock();
2107                         break;
2108                 default:
2109                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2110                                         task->tk_pid, __func__, n);
2111                         error = -EIO;
2112                 }
2113                 dprintk("RPC: %5u %s: call rejected %d\n",
2114                                 task->tk_pid, __func__, n);
2115                 goto out_err;
2116         }
2117         if (!(p = rpcauth_checkverf(task, p))) {
2118                 dprintk("RPC: %5u %s: auth check failed\n",
2119                                 task->tk_pid, __func__);
2120                 goto out_garbage;               /* bad verifier, retry */
2121         }
2122         len = p - (__be32 *)iov->iov_base - 1;
2123         if (len < 0)
2124                 goto out_overflow;
2125         switch ((n = ntohl(*p++))) {
2126         case RPC_SUCCESS:
2127                 return p;
2128         case RPC_PROG_UNAVAIL:
2129                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2130                                 "by server %s\n", task->tk_pid, __func__,
2131                                 (unsigned int)clnt->cl_prog,
2132                                 rcu_dereference(clnt->cl_xprt)->servername);
2133                 error = -EPFNOSUPPORT;
2134                 goto out_err;
2135         case RPC_PROG_MISMATCH:
2136                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2137                                 "by server %s\n", task->tk_pid, __func__,
2138                                 (unsigned int)clnt->cl_prog,
2139                                 (unsigned int)clnt->cl_vers,
2140                                 rcu_dereference(clnt->cl_xprt)->servername);
2141                 error = -EPROTONOSUPPORT;
2142                 goto out_err;
2143         case RPC_PROC_UNAVAIL:
2144                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2145                                 "version %u on server %s\n",
2146                                 task->tk_pid, __func__,
2147                                 rpc_proc_name(task),
2148                                 clnt->cl_prog, clnt->cl_vers,
2149                                 rcu_dereference(clnt->cl_xprt)->servername);
2150                 error = -EOPNOTSUPP;
2151                 goto out_err;
2152         case RPC_GARBAGE_ARGS:
2153                 dprintk("RPC: %5u %s: server saw garbage\n",
2154                                 task->tk_pid, __func__);
2155                 break;                  /* retry */
2156         default:
2157                 dprintk("RPC: %5u %s: server accept status: %x\n",
2158                                 task->tk_pid, __func__, n);
2159                 /* Also retry */
2160         }
2161
2162 out_garbage:
2163         clnt->cl_stats->rpcgarbage++;
2164         if (task->tk_garb_retry) {
2165                 task->tk_garb_retry--;
2166                 dprintk("RPC: %5u %s: retrying\n",
2167                                 task->tk_pid, __func__);
2168                 task->tk_action = call_bind;
2169 out_retry:
2170                 return ERR_PTR(-EAGAIN);
2171         }
2172 out_eio:
2173         error = -EIO;
2174 out_err:
2175         rpc_exit(task, error);
2176         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2177                         __func__, error);
2178         return ERR_PTR(error);
2179 out_overflow:
2180         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2181                         __func__);
2182         goto out_garbage;
2183 }
2184
2185 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2186 {
2187 }
2188
2189 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2190 {
2191         return 0;
2192 }
2193
2194 static struct rpc_procinfo rpcproc_null = {
2195         .p_encode = rpcproc_encode_null,
2196         .p_decode = rpcproc_decode_null,
2197 };
2198
2199 static int rpc_ping(struct rpc_clnt *clnt)
2200 {
2201         struct rpc_message msg = {
2202                 .rpc_proc = &rpcproc_null,
2203         };
2204         int err;
2205         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2206         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2207         put_rpccred(msg.rpc_cred);
2208         return err;
2209 }
2210
2211 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2212 {
2213         struct rpc_message msg = {
2214                 .rpc_proc = &rpcproc_null,
2215                 .rpc_cred = cred,
2216         };
2217         struct rpc_task_setup task_setup_data = {
2218                 .rpc_client = clnt,
2219                 .rpc_message = &msg,
2220                 .callback_ops = &rpc_default_ops,
2221                 .flags = flags,
2222         };
2223         return rpc_run_task(&task_setup_data);
2224 }
2225 EXPORT_SYMBOL_GPL(rpc_call_null);
2226
2227 #ifdef RPC_DEBUG
2228 static void rpc_show_header(void)
2229 {
2230         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2231                 "-timeout ---ops--\n");
2232 }
2233
2234 static void rpc_show_task(const struct rpc_clnt *clnt,
2235                           const struct rpc_task *task)
2236 {
2237         const char *rpc_waitq = "none";
2238
2239         if (RPC_IS_QUEUED(task))
2240                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2241
2242         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2243                 task->tk_pid, task->tk_flags, task->tk_status,
2244                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2245                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2246                 task->tk_action, rpc_waitq);
2247 }
2248
2249 void rpc_show_tasks(struct net *net)
2250 {
2251         struct rpc_clnt *clnt;
2252         struct rpc_task *task;
2253         int header = 0;
2254         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2255
2256         spin_lock(&sn->rpc_client_lock);
2257         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2258                 spin_lock(&clnt->cl_lock);
2259                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2260                         if (!header) {
2261                                 rpc_show_header();
2262                                 header++;
2263                         }
2264                         rpc_show_task(clnt, task);
2265                 }
2266                 spin_unlock(&clnt->cl_lock);
2267         }
2268         spin_unlock(&sn->rpc_client_lock);
2269 }
2270 #endif