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