net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/utsname.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/in.h>
  31 #include <linux/in6.h>
  32 #include <linux/un.h>
  33 #include <linux/rcupdate.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38 #include <linux/sunrpc/bc_xprt.h>
  39 #include <trace/events/sunrpc.h>
  40
  41 #include "sunrpc.h"
  42 #include "netns.h"
  43
  44 #ifdef RPC_DEBUG
  45 # define RPCDBG_FACILITY        RPCDBG_CALL
  46 #endif
  47
  48 #define dprint_status(t)                                        \
  49         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  50                         __func__, t->tk_status)
  51
  52 /*
  53  * All RPC clients are linked into this list
  54  */
  55
  56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  57
  58
  59 static void     call_start(struct rpc_task *task);
  60 static void     call_reserve(struct rpc_task *task);
  61 static void     call_reserveresult(struct rpc_task *task);
  62 static void     call_allocate(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  68 static void     call_bc_transmit(struct rpc_task *task);
  69 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_timeout(struct rpc_task *task);
  75 static void     call_connect(struct rpc_task *task);
  76 static void     call_connect_status(struct rpc_task *task);
  77
  78 static __be32   *rpc_encode_header(struct rpc_task *task);
  79 static __be32   *rpc_verify_header(struct rpc_task *task);
  80 static int      rpc_ping(struct rpc_clnt *clnt);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         if (clnt->cl_dentry) {
 105                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 106                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 107                 rpc_remove_client_dir(clnt->cl_dentry);
 108         }
 109         clnt->cl_dentry = NULL;
 110 }
 111
 112 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 113 {
 114         struct net *net = rpc_net_ns(clnt);
 115         struct super_block *pipefs_sb;
 116
 117         pipefs_sb = rpc_get_sb_net(net);
 118         if (pipefs_sb) {
 119                 __rpc_clnt_remove_pipedir(clnt);
 120                 rpc_put_sb_net(net);
 121         }
 122 }
 123
 124 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 125                                     struct rpc_clnt *clnt,
 126                                     const char *dir_name)
 127 {
 128         static uint32_t clntid;
 129         char name[15];
 130         struct qstr q = { .name = name };
 131         struct dentry *dir, *dentry;
 132         int error;
 133
 134         dir = rpc_d_lookup_sb(sb, dir_name);
 135         if (dir == NULL) {
 136                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 137                 return dir;
 138         }
 139         for (;;) {
 140                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 141                 name[sizeof(name) - 1] = '\0';
 142                 q.hash = full_name_hash(q.name, q.len);
 143                 dentry = rpc_create_client_dir(dir, &q, clnt);
 144                 if (!IS_ERR(dentry))
 145                         break;
 146                 error = PTR_ERR(dentry);
 147                 if (error != -EEXIST) {
 148                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 149                                         " %s/%s, error %d\n",
 150                                         dir_name, name, error);
 151                         break;
 152                 }
 153         }
 154         dput(dir);
 155         return dentry;
 156 }
 157
 158 static int
 159 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 160 {
 161         struct net *net = rpc_net_ns(clnt);
 162         struct super_block *pipefs_sb;
 163         struct dentry *dentry;
 164
 165         clnt->cl_dentry = NULL;
 166         if (dir_name == NULL)
 167                 return 0;
 168         pipefs_sb = rpc_get_sb_net(net);
 169         if (!pipefs_sb)
 170                 return 0;
 171         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 172         rpc_put_sb_net(net);
 173         if (IS_ERR(dentry))
 174                 return PTR_ERR(dentry);
 175         clnt->cl_dentry = dentry;
 176         return 0;
 177 }
 178
 179 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 180 {
 181         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 182             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 183                 return 1;
 184         return 0;
 185 }
 186
 187 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 188                                    struct super_block *sb)
 189 {
 190         struct dentry *dentry;
 191         int err = 0;
 192
 193         switch (event) {
 194         case RPC_PIPEFS_MOUNT:
 195                 dentry = rpc_setup_pipedir_sb(sb, clnt,
 196                                               clnt->cl_program->pipe_dir_name);
 197                 if (!dentry)
 198                         return -ENOENT;
 199                 if (IS_ERR(dentry))
 200                         return PTR_ERR(dentry);
 201                 clnt->cl_dentry = dentry;
 202                 if (clnt->cl_auth->au_ops->pipes_create) {
 203                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 204                         if (err)
 205                                 __rpc_clnt_remove_pipedir(clnt);
 206                 }
 207                 break;
 208         case RPC_PIPEFS_UMOUNT:
 209                 __rpc_clnt_remove_pipedir(clnt);
 210                 break;
 211         default:
 212                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 213                 return -ENOTSUPP;
 214         }
 215         return err;
 216 }
 217
 218 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 219                                 struct super_block *sb)
 220 {
 221         int error = 0;
 222
 223         for (;; clnt = clnt->cl_parent) {
 224                 if (!rpc_clnt_skip_event(clnt, event))
 225                         error = __rpc_clnt_handle_event(clnt, event, sb);
 226                 if (error || clnt == clnt->cl_parent)
 227                         break;
 228         }
 229         return error;
 230 }
 231
 232 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 233 {
 234         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 235         struct rpc_clnt *clnt;
 236
 237         spin_lock(&sn->rpc_client_lock);
 238         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 239                 if (clnt->cl_program->pipe_dir_name == NULL)
 240                         continue;
 241                 if (rpc_clnt_skip_event(clnt, event))
 242                         continue;
 243                 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 244                         continue;
 245                 spin_unlock(&sn->rpc_client_lock);
 246                 return clnt;
 247         }
 248         spin_unlock(&sn->rpc_client_lock);
 249         return NULL;
 250 }
 251
 252 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 253                             void *ptr)
 254 {
 255         struct super_block *sb = ptr;
 256         struct rpc_clnt *clnt;
 257         int error = 0;
 258
 259         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 260                 error = __rpc_pipefs_event(clnt, event, sb);
 261                 rpc_release_client(clnt);
 262                 if (error)
 263                         break;
 264         }
 265         return error;
 266 }
 267
 268 static struct notifier_block rpc_clients_block = {
 269         .notifier_call  = rpc_pipefs_event,
 270         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 271 };
 272
 273 int rpc_clients_notifier_register(void)
 274 {
 275         return rpc_pipefs_notifier_register(&rpc_clients_block);
 276 }
 277
 278 void rpc_clients_notifier_unregister(void)
 279 {
 280         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 281 }
 282
 283 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 284 {
 285         clnt->cl_nodelen = strlen(nodename);
 286         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 287                 clnt->cl_nodelen = UNX_MAXNODENAME;
 288         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 289 }
 290
 291 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 292 {
 293         const struct rpc_program *program = args->program;
 294         const struct rpc_version *version;
 295         struct rpc_clnt         *clnt = NULL;
 296         struct rpc_auth         *auth;
 297         int err;
 298
 299         /* sanity check the name before trying to print it */
 300         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 301                         program->name, args->servername, xprt);
 302
 303         err = rpciod_up();
 304         if (err)
 305                 goto out_no_rpciod;
 306         err = -EINVAL;
 307         if (!xprt)
 308                 goto out_no_xprt;
 309
 310         if (args->version >= program->nrvers)
 311                 goto out_err;
 312         version = program->version[args->version];
 313         if (version == NULL)
 314                 goto out_err;
 315
 316         err = -ENOMEM;
 317         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 318         if (!clnt)
 319                 goto out_err;
 320         clnt->cl_parent = clnt;
 321
 322         rcu_assign_pointer(clnt->cl_xprt, xprt);
 323         clnt->cl_procinfo = version->procs;
 324         clnt->cl_maxproc  = version->nrprocs;
 325         clnt->cl_protname = program->name;
 326         clnt->cl_prog     = args->prognumber ? : program->number;
 327         clnt->cl_vers     = version->number;
 328         clnt->cl_stats    = program->stats;
 329         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 330         err = -ENOMEM;
 331         if (clnt->cl_metrics == NULL)
 332                 goto out_no_stats;
 333         clnt->cl_program  = program;
 334         INIT_LIST_HEAD(&clnt->cl_tasks);
 335         spin_lock_init(&clnt->cl_lock);
 336
 337         if (!xprt_bound(xprt))
 338                 clnt->cl_autobind = 1;
 339
 340         clnt->cl_timeout = xprt->timeout;
 341         if (args->timeout != NULL) {
 342                 memcpy(&clnt->cl_timeout_default, args->timeout,
 343                                 sizeof(clnt->cl_timeout_default));
 344                 clnt->cl_timeout = &clnt->cl_timeout_default;
 345         }
 346
 347         clnt->cl_rtt = &clnt->cl_rtt_default;
 348         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 349         clnt->cl_principal = NULL;
 350         if (args->client_name) {
 351                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 352                 if (!clnt->cl_principal)
 353                         goto out_no_principal;
 354         }
 355
 356         atomic_set(&clnt->cl_count, 1);
 357
 358         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 359         if (err < 0)
 360                 goto out_no_path;
 361
 362         auth = rpcauth_create(args->authflavor, clnt);
 363         if (IS_ERR(auth)) {
 364                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 365                                 args->authflavor);
 366                 err = PTR_ERR(auth);
 367                 goto out_no_auth;
 368         }
 369
 370         /* save the nodename */
 371         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 372         rpc_register_client(clnt);
 373         return clnt;
 374
 375 out_no_auth:
 376         rpc_clnt_remove_pipedir(clnt);
 377 out_no_path:
 378         kfree(clnt->cl_principal);
 379 out_no_principal:
 380         rpc_free_iostats(clnt->cl_metrics);
 381 out_no_stats:
 382         kfree(clnt);
 383 out_err:
 384         xprt_put(xprt);
 385 out_no_xprt:
 386         rpciod_down();
 387 out_no_rpciod:
 388         return ERR_PTR(err);
 389 }
 390
 391 /**
 392  * rpc_create - create an RPC client and transport with one call
 393  * @args: rpc_clnt create argument structure
 394  *
 395  * Creates and initializes an RPC transport and an RPC client.
 396  *
 397  * It can ping the server in order to determine if it is up, and to see if
 398  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 399  * this behavior so asynchronous tasks can also use rpc_create.
 400  */
 401 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 402 {
 403         struct rpc_xprt *xprt;
 404         struct rpc_clnt *clnt;
 405         struct xprt_create xprtargs = {
 406                 .net = args->net,
 407                 .ident = args->protocol,
 408                 .srcaddr = args->saddress,
 409                 .dstaddr = args->address,
 410                 .addrlen = args->addrsize,
 411                 .servername = args->servername,
 412                 .bc_xprt = args->bc_xprt,
 413         };
 414         char servername[48];
 415
 416         /*
 417          * If the caller chooses not to specify a hostname, whip
 418          * up a string representation of the passed-in address.
 419          */
 420         if (xprtargs.servername == NULL) {
 421                 struct sockaddr_un *sun =
 422                                 (struct sockaddr_un *)args->address;
 423                 struct sockaddr_in *sin =
 424                                 (struct sockaddr_in *)args->address;
 425                 struct sockaddr_in6 *sin6 =
 426                                 (struct sockaddr_in6 *)args->address;
 427
 428                 servername[0] = '\0';
 429                 switch (args->address->sa_family) {
 430                 case AF_LOCAL:
 431                         snprintf(servername, sizeof(servername), "%s",
 432                                  sun->sun_path);
 433                         break;
 434                 case AF_INET:
 435                         snprintf(servername, sizeof(servername), "%pI4",
 436                                  &sin->sin_addr.s_addr);
 437                         break;
 438                 case AF_INET6:
 439                         snprintf(servername, sizeof(servername), "%pI6",
 440                                  &sin6->sin6_addr);
 441                         break;
 442                 default:
 443                         /* caller wants default server name, but
 444                          * address family isn't recognized. */
 445                         return ERR_PTR(-EINVAL);
 446                 }
 447                 xprtargs.servername = servername;
 448         }
 449
 450         xprt = xprt_create_transport(&xprtargs);
 451         if (IS_ERR(xprt))
 452                 return (struct rpc_clnt *)xprt;
 453
 454         /*
 455          * By default, kernel RPC client connects from a reserved port.
 456          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 457          * but it is always enabled for rpciod, which handles the connect
 458          * operation.
 459          */
 460         xprt->resvport = 1;
 461         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 462                 xprt->resvport = 0;
 463
 464         clnt = rpc_new_client(args, xprt);
 465         if (IS_ERR(clnt))
 466                 return clnt;
 467
 468         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 469                 int err = rpc_ping(clnt);
 470                 if (err != 0) {
 471                         rpc_shutdown_client(clnt);
 472                         return ERR_PTR(err);
 473                 }
 474         }
 475
 476         clnt->cl_softrtry = 1;
 477         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 478                 clnt->cl_softrtry = 0;
 479
 480         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 481                 clnt->cl_autobind = 1;
 482         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 483                 clnt->cl_discrtry = 1;
 484         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 485                 clnt->cl_chatty = 1;
 486
 487         return clnt;
 488 }
 489 EXPORT_SYMBOL_GPL(rpc_create);
 490
 491 /*
 492  * This function clones the RPC client structure. It allows us to share the
 493  * same transport while varying parameters such as the authentication
 494  * flavour.
 495  */
 496 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 497                                            struct rpc_clnt *clnt)
 498 {
 499         struct rpc_xprt *xprt;
 500         struct rpc_clnt *new;
 501         int err;
 502
 503         err = -ENOMEM;
 504         rcu_read_lock();
 505         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 506         rcu_read_unlock();
 507         if (xprt == NULL)
 508                 goto out_err;
 509         args->servername = xprt->servername;
 510
 511         new = rpc_new_client(args, xprt);
 512         if (IS_ERR(new)) {
 513                 err = PTR_ERR(new);
 514                 goto out_put;
 515         }
 516
 517         atomic_inc(&clnt->cl_count);
 518         new->cl_parent = clnt;
 519
 520         /* Turn off autobind on clones */
 521         new->cl_autobind = 0;
 522         new->cl_softrtry = clnt->cl_softrtry;
 523         new->cl_discrtry = clnt->cl_discrtry;
 524         new->cl_chatty = clnt->cl_chatty;
 525         return new;
 526
 527 out_put:
 528         xprt_put(xprt);
 529 out_err:
 530         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 531         return ERR_PTR(err);
 532 }
 533
 534 /**
 535  * rpc_clone_client - Clone an RPC client structure
 536  *
 537  * @clnt: RPC client whose parameters are copied
 538  *
 539  * Returns a fresh RPC client or an ERR_PTR.
 540  */
 541 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 542 {
 543         struct rpc_create_args args = {
 544                 .program        = clnt->cl_program,
 545                 .prognumber     = clnt->cl_prog,
 546                 .version        = clnt->cl_vers,
 547                 .authflavor     = clnt->cl_auth->au_flavor,
 548                 .client_name    = clnt->cl_principal,
 549         };
 550         return __rpc_clone_client(&args, clnt);
 551 }
 552 EXPORT_SYMBOL_GPL(rpc_clone_client);
 553
 554 /**
 555  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 556  *
 557  * @clnt: RPC client whose parameters are copied
 558  * @flavor: 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         might_sleep();
 614
 615         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 616                         clnt->cl_protname,
 617                         rcu_dereference(clnt->cl_xprt)->servername);
 618
 619         while (!list_empty(&clnt->cl_tasks)) {
 620                 rpc_killall_tasks(clnt);
 621                 wait_event_timeout(destroy_wait,
 622                         list_empty(&clnt->cl_tasks), 1*HZ);
 623         }
 624
 625         rpc_release_client(clnt);
 626 }
 627 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 628
 629 /*
 630  * Free an RPC client
 631  */
 632 static void
 633 rpc_free_client(struct rpc_clnt *clnt)
 634 {
 635         dprintk_rcu("RPC:       destroying %s client for %s\n",
 636                         clnt->cl_protname,
 637                         rcu_dereference(clnt->cl_xprt)->servername);
 638         if (clnt->cl_parent != clnt)
 639                 rpc_release_client(clnt->cl_parent);
 640         rpc_unregister_client(clnt);
 641         rpc_clnt_remove_pipedir(clnt);
 642         rpc_free_iostats(clnt->cl_metrics);
 643         kfree(clnt->cl_principal);
 644         clnt->cl_metrics = NULL;
 645         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 646         rpciod_down();
 647         kfree(clnt);
 648 }
 649
 650 /*
 651  * Free an RPC client
 652  */
 653 static void
 654 rpc_free_auth(struct rpc_clnt *clnt)
 655 {
 656         if (clnt->cl_auth == NULL) {
 657                 rpc_free_client(clnt);
 658                 return;
 659         }
 660
 661         /*
 662          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 663          *       release remaining GSS contexts. This mechanism ensures
 664          *       that it can do so safely.
 665          */
 666         atomic_inc(&clnt->cl_count);
 667         rpcauth_release(clnt->cl_auth);
 668         clnt->cl_auth = NULL;
 669         if (atomic_dec_and_test(&clnt->cl_count))
 670                 rpc_free_client(clnt);
 671 }
 672
 673 /*
 674  * Release reference to the RPC client
 675  */
 676 void
 677 rpc_release_client(struct rpc_clnt *clnt)
 678 {
 679         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 680
 681         if (list_empty(&clnt->cl_tasks))
 682                 wake_up(&destroy_wait);
 683         if (atomic_dec_and_test(&clnt->cl_count))
 684                 rpc_free_auth(clnt);
 685 }
 686
 687 /**
 688  * rpc_bind_new_program - bind a new RPC program to an existing client
 689  * @old: old rpc_client
 690  * @program: rpc program to set
 691  * @vers: rpc program version
 692  *
 693  * Clones the rpc client and sets up a new RPC program. This is mainly
 694  * of use for enabling different RPC programs to share the same transport.
 695  * The Sun NFSv2/v3 ACL protocol can do this.
 696  */
 697 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 698                                       const struct rpc_program *program,
 699                                       u32 vers)
 700 {
 701         struct rpc_create_args args = {
 702                 .program        = program,
 703                 .prognumber     = program->number,
 704                 .version        = vers,
 705                 .authflavor     = old->cl_auth->au_flavor,
 706                 .client_name    = old->cl_principal,
 707         };
 708         struct rpc_clnt *clnt;
 709         int err;
 710
 711         clnt = __rpc_clone_client(&args, old);
 712         if (IS_ERR(clnt))
 713                 goto out;
 714         err = rpc_ping(clnt);
 715         if (err != 0) {
 716                 rpc_shutdown_client(clnt);
 717                 clnt = ERR_PTR(err);
 718         }
 719 out:
 720         return clnt;
 721 }
 722 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 723
 724 void rpc_task_release_client(struct rpc_task *task)
 725 {
 726         struct rpc_clnt *clnt = task->tk_client;
 727
 728         if (clnt != NULL) {
 729                 /* Remove from client task list */
 730                 spin_lock(&clnt->cl_lock);
 731                 list_del(&task->tk_task);
 732                 spin_unlock(&clnt->cl_lock);
 733                 task->tk_client = NULL;
 734
 735                 rpc_release_client(clnt);
 736         }
 737 }
 738
 739 static
 740 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 741 {
 742         if (clnt != NULL) {
 743                 rpc_task_release_client(task);
 744                 task->tk_client = clnt;
 745                 atomic_inc(&clnt->cl_count);
 746                 if (clnt->cl_softrtry)
 747                         task->tk_flags |= RPC_TASK_SOFT;
 748                 if (sk_memalloc_socks()) {
 749                         struct rpc_xprt *xprt;
 750
 751                         rcu_read_lock();
 752                         xprt = rcu_dereference(clnt->cl_xprt);
 753                         if (xprt->swapper)
 754                                 task->tk_flags |= RPC_TASK_SWAPPER;
 755                         rcu_read_unlock();
 756                 }
 757                 /* Add to the client's list of all tasks */
 758                 spin_lock(&clnt->cl_lock);
 759                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 760                 spin_unlock(&clnt->cl_lock);
 761         }
 762 }
 763
 764 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 765 {
 766         rpc_task_release_client(task);
 767         rpc_task_set_client(task, clnt);
 768 }
 769 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 770
 771
 772 static void
 773 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 774 {
 775         if (msg != NULL) {
 776                 task->tk_msg.rpc_proc = msg->rpc_proc;
 777                 task->tk_msg.rpc_argp = msg->rpc_argp;
 778                 task->tk_msg.rpc_resp = msg->rpc_resp;
 779                 if (msg->rpc_cred != NULL)
 780                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 781         }
 782 }
 783
 784 /*
 785  * Default callback for async RPC calls
 786  */
 787 static void
 788 rpc_default_callback(struct rpc_task *task, void *data)
 789 {
 790 }
 791
 792 static const struct rpc_call_ops rpc_default_ops = {
 793         .rpc_call_done = rpc_default_callback,
 794 };
 795
 796 /**
 797  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 798  * @task_setup_data: pointer to task initialisation data
 799  */
 800 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 801 {
 802         struct rpc_task *task;
 803
 804         task = rpc_new_task(task_setup_data);
 805         if (IS_ERR(task))
 806                 goto out;
 807
 808         rpc_task_set_client(task, task_setup_data->rpc_client);
 809         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 810
 811         if (task->tk_action == NULL)
 812                 rpc_call_start(task);
 813
 814         atomic_inc(&task->tk_count);
 815         rpc_execute(task);
 816 out:
 817         return task;
 818 }
 819 EXPORT_SYMBOL_GPL(rpc_run_task);
 820
 821 /**
 822  * rpc_call_sync - Perform a synchronous RPC call
 823  * @clnt: pointer to RPC client
 824  * @msg: RPC call parameters
 825  * @flags: RPC call flags
 826  */
 827 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 828 {
 829         struct rpc_task *task;
 830         struct rpc_task_setup task_setup_data = {
 831                 .rpc_client = clnt,
 832                 .rpc_message = msg,
 833                 .callback_ops = &rpc_default_ops,
 834                 .flags = flags,
 835         };
 836         int status;
 837
 838         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 839         if (flags & RPC_TASK_ASYNC) {
 840                 rpc_release_calldata(task_setup_data.callback_ops,
 841                         task_setup_data.callback_data);
 842                 return -EINVAL;
 843         }
 844
 845         task = rpc_run_task(&task_setup_data);
 846         if (IS_ERR(task))
 847                 return PTR_ERR(task);
 848         status = task->tk_status;
 849         rpc_put_task(task);
 850         return status;
 851 }
 852 EXPORT_SYMBOL_GPL(rpc_call_sync);
 853
 854 /**
 855  * rpc_call_async - Perform an asynchronous RPC call
 856  * @clnt: pointer to RPC client
 857  * @msg: RPC call parameters
 858  * @flags: RPC call flags
 859  * @tk_ops: RPC call ops
 860  * @data: user call data
 861  */
 862 int
 863 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 864                const struct rpc_call_ops *tk_ops, void *data)
 865 {
 866         struct rpc_task *task;
 867         struct rpc_task_setup task_setup_data = {
 868                 .rpc_client = clnt,
 869                 .rpc_message = msg,
 870                 .callback_ops = tk_ops,
 871                 .callback_data = data,
 872                 .flags = flags|RPC_TASK_ASYNC,
 873         };
 874
 875         task = rpc_run_task(&task_setup_data);
 876         if (IS_ERR(task))
 877                 return PTR_ERR(task);
 878         rpc_put_task(task);
 879         return 0;
 880 }
 881 EXPORT_SYMBOL_GPL(rpc_call_async);
 882
 883 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 884 /**
 885  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 886  * rpc_execute against it
 887  * @req: RPC request
 888  * @tk_ops: RPC call ops
 889  */
 890 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 891                                 const struct rpc_call_ops *tk_ops)
 892 {
 893         struct rpc_task *task;
 894         struct xdr_buf *xbufp = &req->rq_snd_buf;
 895         struct rpc_task_setup task_setup_data = {
 896                 .callback_ops = tk_ops,
 897         };
 898
 899         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 900         /*
 901          * Create an rpc_task to send the data
 902          */
 903         task = rpc_new_task(&task_setup_data);
 904         if (IS_ERR(task)) {
 905                 xprt_free_bc_request(req);
 906                 goto out;
 907         }
 908         task->tk_rqstp = req;
 909
 910         /*
 911          * Set up the xdr_buf length.
 912          * This also indicates that the buffer is XDR encoded already.
 913          */
 914         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 915                         xbufp->tail[0].iov_len;
 916
 917         task->tk_action = call_bc_transmit;
 918         atomic_inc(&task->tk_count);
 919         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 920         rpc_execute(task);
 921
 922 out:
 923         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 924         return task;
 925 }
 926 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 927
 928 void
 929 rpc_call_start(struct rpc_task *task)
 930 {
 931         task->tk_action = call_start;
 932 }
 933 EXPORT_SYMBOL_GPL(rpc_call_start);
 934
 935 /**
 936  * rpc_peeraddr - extract remote peer address from clnt's xprt
 937  * @clnt: RPC client structure
 938  * @buf: target buffer
 939  * @bufsize: length of target buffer
 940  *
 941  * Returns the number of bytes that are actually in the stored address.
 942  */
 943 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 944 {
 945         size_t bytes;
 946         struct rpc_xprt *xprt;
 947
 948         rcu_read_lock();
 949         xprt = rcu_dereference(clnt->cl_xprt);
 950
 951         bytes = xprt->addrlen;
 952         if (bytes > bufsize)
 953                 bytes = bufsize;
 954         memcpy(buf, &xprt->addr, bytes);
 955         rcu_read_unlock();
 956
 957         return bytes;
 958 }
 959 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 960
 961 /**
 962  * rpc_peeraddr2str - return remote peer address in printable format
 963  * @clnt: RPC client structure
 964  * @format: address format
 965  *
 966  * NB: the lifetime of the memory referenced by the returned pointer is
 967  * the same as the rpc_xprt itself.  As long as the caller uses this
 968  * pointer, it must hold the RCU read lock.
 969  */
 970 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 971                              enum rpc_display_format_t format)
 972 {
 973         struct rpc_xprt *xprt;
 974
 975         xprt = rcu_dereference(clnt->cl_xprt);
 976
 977         if (xprt->address_strings[format] != NULL)
 978                 return xprt->address_strings[format];
 979         else
 980                 return "unprintable";
 981 }
 982 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 983
 984 static const struct sockaddr_in rpc_inaddr_loopback = {
 985         .sin_family             = AF_INET,
 986         .sin_addr.s_addr        = htonl(INADDR_ANY),
 987 };
 988
 989 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 990         .sin6_family            = AF_INET6,
 991         .sin6_addr              = IN6ADDR_ANY_INIT,
 992 };
 993
 994 /*
 995  * Try a getsockname() on a connected datagram socket.  Using a
 996  * connected datagram socket prevents leaving a socket in TIME_WAIT.
 997  * This conserves the ephemeral port number space.
 998  *
 999  * Returns zero and fills in "buf" if successful; otherwise, a
1000  * negative errno is returned.
1001  */
1002 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1003                         struct sockaddr *buf, int buflen)
1004 {
1005         struct socket *sock;
1006         int err;
1007
1008         err = __sock_create(net, sap->sa_family,
1009                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1010         if (err < 0) {
1011                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1012                 goto out;
1013         }
1014
1015         switch (sap->sa_family) {
1016         case AF_INET:
1017                 err = kernel_bind(sock,
1018                                 (struct sockaddr *)&rpc_inaddr_loopback,
1019                                 sizeof(rpc_inaddr_loopback));
1020                 break;
1021         case AF_INET6:
1022                 err = kernel_bind(sock,
1023                                 (struct sockaddr *)&rpc_in6addr_loopback,
1024                                 sizeof(rpc_in6addr_loopback));
1025                 break;
1026         default:
1027                 err = -EAFNOSUPPORT;
1028                 goto out;
1029         }
1030         if (err < 0) {
1031                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1032                 goto out_release;
1033         }
1034
1035         err = kernel_connect(sock, sap, salen, 0);
1036         if (err < 0) {
1037                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1038                 goto out_release;
1039         }
1040
1041         err = kernel_getsockname(sock, buf, &buflen);
1042         if (err < 0) {
1043                 dprintk("RPC:       getsockname failed (%d)\n", err);
1044                 goto out_release;
1045         }
1046
1047         err = 0;
1048         if (buf->sa_family == AF_INET6) {
1049                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1050                 sin6->sin6_scope_id = 0;
1051         }
1052         dprintk("RPC:       %s succeeded\n", __func__);
1053
1054 out_release:
1055         sock_release(sock);
1056 out:
1057         return err;
1058 }
1059
1060 /*
1061  * Scraping a connected socket failed, so we don't have a useable
1062  * local address.  Fallback: generate an address that will prevent
1063  * the server from calling us back.
1064  *
1065  * Returns zero and fills in "buf" if successful; otherwise, a
1066  * negative errno is returned.
1067  */
1068 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1069 {
1070         switch (family) {
1071         case AF_INET:
1072                 if (buflen < sizeof(rpc_inaddr_loopback))
1073                         return -EINVAL;
1074                 memcpy(buf, &rpc_inaddr_loopback,
1075                                 sizeof(rpc_inaddr_loopback));
1076                 break;
1077         case AF_INET6:
1078                 if (buflen < sizeof(rpc_in6addr_loopback))
1079                         return -EINVAL;
1080                 memcpy(buf, &rpc_in6addr_loopback,
1081                                 sizeof(rpc_in6addr_loopback));
1082         default:
1083                 dprintk("RPC:       %s: address family not supported\n",
1084                         __func__);
1085                 return -EAFNOSUPPORT;
1086         }
1087         dprintk("RPC:       %s: succeeded\n", __func__);
1088         return 0;
1089 }
1090
1091 /**
1092  * rpc_localaddr - discover local endpoint address for an RPC client
1093  * @clnt: RPC client structure
1094  * @buf: target buffer
1095  * @buflen: size of target buffer, in bytes
1096  *
1097  * Returns zero and fills in "buf" and "buflen" if successful;
1098  * otherwise, a negative errno is returned.
1099  *
1100  * This works even if the underlying transport is not currently connected,
1101  * or if the upper layer never previously provided a source address.
1102  *
1103  * The result of this function call is transient: multiple calls in
1104  * succession may give different results, depending on how local
1105  * networking configuration changes over time.
1106  */
1107 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1108 {
1109         struct sockaddr_storage address;
1110         struct sockaddr *sap = (struct sockaddr *)&address;
1111         struct rpc_xprt *xprt;
1112         struct net *net;
1113         size_t salen;
1114         int err;
1115
1116         rcu_read_lock();
1117         xprt = rcu_dereference(clnt->cl_xprt);
1118         salen = xprt->addrlen;
1119         memcpy(sap, &xprt->addr, salen);
1120         net = get_net(xprt->xprt_net);
1121         rcu_read_unlock();
1122
1123         rpc_set_port(sap, 0);
1124         err = rpc_sockname(net, sap, salen, buf, buflen);
1125         put_net(net);
1126         if (err != 0)
1127                 /* Couldn't discover local address, return ANYADDR */
1128                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1129         return 0;
1130 }
1131 EXPORT_SYMBOL_GPL(rpc_localaddr);
1132
1133 void
1134 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1135 {
1136         struct rpc_xprt *xprt;
1137
1138         rcu_read_lock();
1139         xprt = rcu_dereference(clnt->cl_xprt);
1140         if (xprt->ops->set_buffer_size)
1141                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1142         rcu_read_unlock();
1143 }
1144 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1145
1146 /**
1147  * rpc_protocol - Get transport protocol number for an RPC client
1148  * @clnt: RPC client to query
1149  *
1150  */
1151 int rpc_protocol(struct rpc_clnt *clnt)
1152 {
1153         int protocol;
1154
1155         rcu_read_lock();
1156         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1157         rcu_read_unlock();
1158         return protocol;
1159 }
1160 EXPORT_SYMBOL_GPL(rpc_protocol);
1161
1162 /**
1163  * rpc_net_ns - Get the network namespace for this RPC client
1164  * @clnt: RPC client to query
1165  *
1166  */
1167 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1168 {
1169         struct net *ret;
1170
1171         rcu_read_lock();
1172         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1173         rcu_read_unlock();
1174         return ret;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_net_ns);
1177
1178 /**
1179  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1180  * @clnt: RPC client to query
1181  *
1182  * For stream transports, this is one RPC record fragment (see RFC
1183  * 1831), as we don't support multi-record requests yet.  For datagram
1184  * transports, this is the size of an IP packet minus the IP, UDP, and
1185  * RPC header sizes.
1186  */
1187 size_t rpc_max_payload(struct rpc_clnt *clnt)
1188 {
1189         size_t ret;
1190
1191         rcu_read_lock();
1192         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1193         rcu_read_unlock();
1194         return ret;
1195 }
1196 EXPORT_SYMBOL_GPL(rpc_max_payload);
1197
1198 /**
1199  * rpc_get_timeout - Get timeout for transport in units of HZ
1200  * @clnt: RPC client to query
1201  */
1202 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1203 {
1204         unsigned long ret;
1205
1206         rcu_read_lock();
1207         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1208         rcu_read_unlock();
1209         return ret;
1210 }
1211 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1212
1213 /**
1214  * rpc_force_rebind - force transport to check that remote port is unchanged
1215  * @clnt: client to rebind
1216  *
1217  */
1218 void rpc_force_rebind(struct rpc_clnt *clnt)
1219 {
1220         if (clnt->cl_autobind) {
1221                 rcu_read_lock();
1222                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1223                 rcu_read_unlock();
1224         }
1225 }
1226 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1227
1228 /*
1229  * Restart an (async) RPC call from the call_prepare state.
1230  * Usually called from within the exit handler.
1231  */
1232 int
1233 rpc_restart_call_prepare(struct rpc_task *task)
1234 {
1235         if (RPC_ASSASSINATED(task))
1236                 return 0;
1237         task->tk_action = call_start;
1238         if (task->tk_ops->rpc_call_prepare != NULL)
1239                 task->tk_action = rpc_prepare_task;
1240         return 1;
1241 }
1242 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1243
1244 /*
1245  * Restart an (async) RPC call. Usually called from within the
1246  * exit handler.
1247  */
1248 int
1249 rpc_restart_call(struct rpc_task *task)
1250 {
1251         if (RPC_ASSASSINATED(task))
1252                 return 0;
1253         task->tk_action = call_start;
1254         return 1;
1255 }
1256 EXPORT_SYMBOL_GPL(rpc_restart_call);
1257
1258 #ifdef RPC_DEBUG
1259 static const char *rpc_proc_name(const struct rpc_task *task)
1260 {
1261         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1262
1263         if (proc) {
1264                 if (proc->p_name)
1265                         return proc->p_name;
1266                 else
1267                         return "NULL";
1268         } else
1269                 return "no proc";
1270 }
1271 #endif
1272
1273 /*
1274  * 0.  Initial state
1275  *
1276  *     Other FSM states can be visited zero or more times, but
1277  *     this state is visited exactly once for each RPC.
1278  */
1279 static void
1280 call_start(struct rpc_task *task)
1281 {
1282         struct rpc_clnt *clnt = task->tk_client;
1283
1284         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1285                         clnt->cl_protname, clnt->cl_vers,
1286                         rpc_proc_name(task),
1287                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1288
1289         /* Increment call count */
1290         task->tk_msg.rpc_proc->p_count++;
1291         clnt->cl_stats->rpccnt++;
1292         task->tk_action = call_reserve;
1293 }
1294
1295 /*
1296  * 1.   Reserve an RPC call slot
1297  */
1298 static void
1299 call_reserve(struct rpc_task *task)
1300 {
1301         dprint_status(task);
1302
1303         task->tk_status  = 0;
1304         task->tk_action  = call_reserveresult;
1305         xprt_reserve(task);
1306 }
1307
1308 /*
1309  * 1b.  Grok the result of xprt_reserve()
1310  */
1311 static void
1312 call_reserveresult(struct rpc_task *task)
1313 {
1314         int status = task->tk_status;
1315
1316         dprint_status(task);
1317
1318         /*
1319          * After a call to xprt_reserve(), we must have either
1320          * a request slot or else an error status.
1321          */
1322         task->tk_status = 0;
1323         if (status >= 0) {
1324                 if (task->tk_rqstp) {
1325                         task->tk_action = call_refresh;
1326                         return;
1327                 }
1328
1329                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1330                                 __func__, status);
1331                 rpc_exit(task, -EIO);
1332                 return;
1333         }
1334
1335         /*
1336          * Even though there was an error, we may have acquired
1337          * a request slot somehow.  Make sure not to leak it.
1338          */
1339         if (task->tk_rqstp) {
1340                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1341                                 __func__, status);
1342                 xprt_release(task);
1343         }
1344
1345         switch (status) {
1346         case -ENOMEM:
1347                 rpc_delay(task, HZ >> 2);
1348         case -EAGAIN:   /* woken up; retry */
1349                 task->tk_action = call_reserve;
1350                 return;
1351         case -EIO:      /* probably a shutdown */
1352                 break;
1353         default:
1354                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1355                                 __func__, status);
1356                 break;
1357         }
1358         rpc_exit(task, status);
1359 }
1360
1361 /*
1362  * 2.   Bind and/or refresh the credentials
1363  */
1364 static void
1365 call_refresh(struct rpc_task *task)
1366 {
1367         dprint_status(task);
1368
1369         task->tk_action = call_refreshresult;
1370         task->tk_status = 0;
1371         task->tk_client->cl_stats->rpcauthrefresh++;
1372         rpcauth_refreshcred(task);
1373 }
1374
1375 /*
1376  * 2a.  Process the results of a credential refresh
1377  */
1378 static void
1379 call_refreshresult(struct rpc_task *task)
1380 {
1381         int status = task->tk_status;
1382
1383         dprint_status(task);
1384
1385         task->tk_status = 0;
1386         task->tk_action = call_refresh;
1387         switch (status) {
1388         case 0:
1389                 if (rpcauth_uptodatecred(task))
1390                         task->tk_action = call_allocate;
1391                 return;
1392         case -ETIMEDOUT:
1393                 rpc_delay(task, 3*HZ);
1394         case -EKEYEXPIRED:
1395         case -EAGAIN:
1396                 status = -EACCES;
1397                 if (!task->tk_cred_retry)
1398                         break;
1399                 task->tk_cred_retry--;
1400                 dprintk("RPC: %5u %s: retry refresh creds\n",
1401                                 task->tk_pid, __func__);
1402                 return;
1403         }
1404         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1405                                 task->tk_pid, __func__, status);
1406         rpc_exit(task, status);
1407 }
1408
1409 /*
1410  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1411  *      (Note: buffer memory is freed in xprt_release).
1412  */
1413 static void
1414 call_allocate(struct rpc_task *task)
1415 {
1416         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1417         struct rpc_rqst *req = task->tk_rqstp;
1418         struct rpc_xprt *xprt = req->rq_xprt;
1419         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1420
1421         dprint_status(task);
1422
1423         task->tk_status = 0;
1424         task->tk_action = call_bind;
1425
1426         if (req->rq_buffer)
1427                 return;
1428
1429         if (proc->p_proc != 0) {
1430                 BUG_ON(proc->p_arglen == 0);
1431                 if (proc->p_decode != NULL)
1432                         BUG_ON(proc->p_replen == 0);
1433         }
1434
1435         /*
1436          * Calculate the size (in quads) of the RPC call
1437          * and reply headers, and convert both values
1438          * to byte sizes.
1439          */
1440         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1441         req->rq_callsize <<= 2;
1442         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1443         req->rq_rcvsize <<= 2;
1444
1445         req->rq_buffer = xprt->ops->buf_alloc(task,
1446                                         req->rq_callsize + req->rq_rcvsize);
1447         if (req->rq_buffer != NULL)
1448                 return;
1449
1450         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1451
1452         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1453                 task->tk_action = call_allocate;
1454                 rpc_delay(task, HZ>>4);
1455                 return;
1456         }
1457
1458         rpc_exit(task, -ERESTARTSYS);
1459 }
1460
1461 static inline int
1462 rpc_task_need_encode(struct rpc_task *task)
1463 {
1464         return task->tk_rqstp->rq_snd_buf.len == 0;
1465 }
1466
1467 static inline void
1468 rpc_task_force_reencode(struct rpc_task *task)
1469 {
1470         task->tk_rqstp->rq_snd_buf.len = 0;
1471         task->tk_rqstp->rq_bytes_sent = 0;
1472 }
1473
1474 static inline void
1475 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1476 {
1477         buf->head[0].iov_base = start;
1478         buf->head[0].iov_len = len;
1479         buf->tail[0].iov_len = 0;
1480         buf->page_len = 0;
1481         buf->flags = 0;
1482         buf->len = 0;
1483         buf->buflen = len;
1484 }
1485
1486 /*
1487  * 3.   Encode arguments of an RPC call
1488  */
1489 static void
1490 rpc_xdr_encode(struct rpc_task *task)
1491 {
1492         struct rpc_rqst *req = task->tk_rqstp;
1493         kxdreproc_t     encode;
1494         __be32          *p;
1495
1496         dprint_status(task);
1497
1498         rpc_xdr_buf_init(&req->rq_snd_buf,
1499                          req->rq_buffer,
1500                          req->rq_callsize);
1501         rpc_xdr_buf_init(&req->rq_rcv_buf,
1502                          (char *)req->rq_buffer + req->rq_callsize,
1503                          req->rq_rcvsize);
1504
1505         p = rpc_encode_header(task);
1506         if (p == NULL) {
1507                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1508                 rpc_exit(task, -EIO);
1509                 return;
1510         }
1511
1512         encode = task->tk_msg.rpc_proc->p_encode;
1513         if (encode == NULL)
1514                 return;
1515
1516         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1517                         task->tk_msg.rpc_argp);
1518 }
1519
1520 /*
1521  * 4.   Get the server port number if not yet set
1522  */
1523 static void
1524 call_bind(struct rpc_task *task)
1525 {
1526         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1527
1528         dprint_status(task);
1529
1530         task->tk_action = call_connect;
1531         if (!xprt_bound(xprt)) {
1532                 task->tk_action = call_bind_status;
1533                 task->tk_timeout = xprt->bind_timeout;
1534                 xprt->ops->rpcbind(task);
1535         }
1536 }
1537
1538 /*
1539  * 4a.  Sort out bind result
1540  */
1541 static void
1542 call_bind_status(struct rpc_task *task)
1543 {
1544         int status = -EIO;
1545
1546         if (task->tk_status >= 0) {
1547                 dprint_status(task);
1548                 task->tk_status = 0;
1549                 task->tk_action = call_connect;
1550                 return;
1551         }
1552
1553         trace_rpc_bind_status(task);
1554         switch (task->tk_status) {
1555         case -ENOMEM:
1556                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1557                 rpc_delay(task, HZ >> 2);
1558                 goto retry_timeout;
1559         case -EACCES:
1560                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1561                                 "unavailable\n", task->tk_pid);
1562                 /* fail immediately if this is an RPC ping */
1563                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1564                         status = -EOPNOTSUPP;
1565                         break;
1566                 }
1567                 if (task->tk_rebind_retry == 0)
1568                         break;
1569                 task->tk_rebind_retry--;
1570                 rpc_delay(task, 3*HZ);
1571                 goto retry_timeout;
1572         case -ETIMEDOUT:
1573                 dprintk("RPC: %5u rpcbind request timed out\n",
1574                                 task->tk_pid);
1575                 goto retry_timeout;
1576         case -EPFNOSUPPORT:
1577                 /* server doesn't support any rpcbind version we know of */
1578                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1579                                 task->tk_pid);
1580                 break;
1581         case -EPROTONOSUPPORT:
1582                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1583                                 task->tk_pid);
1584                 task->tk_status = 0;
1585                 task->tk_action = call_bind;
1586                 return;
1587         case -ECONNREFUSED:             /* connection problems */
1588         case -ECONNRESET:
1589         case -ENOTCONN:
1590         case -EHOSTDOWN:
1591         case -EHOSTUNREACH:
1592         case -ENETUNREACH:
1593         case -EPIPE:
1594                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1595                                 task->tk_pid, task->tk_status);
1596                 if (!RPC_IS_SOFTCONN(task)) {
1597                         rpc_delay(task, 5*HZ);
1598                         goto retry_timeout;
1599                 }
1600                 status = task->tk_status;
1601                 break;
1602         default:
1603                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1604                                 task->tk_pid, -task->tk_status);
1605         }
1606
1607         rpc_exit(task, status);
1608         return;
1609
1610 retry_timeout:
1611         task->tk_action = call_timeout;
1612 }
1613
1614 /*
1615  * 4b.  Connect to the RPC server
1616  */
1617 static void
1618 call_connect(struct rpc_task *task)
1619 {
1620         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1621
1622         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1623                         task->tk_pid, xprt,
1624                         (xprt_connected(xprt) ? "is" : "is not"));
1625
1626         task->tk_action = call_transmit;
1627         if (!xprt_connected(xprt)) {
1628                 task->tk_action = call_connect_status;
1629                 if (task->tk_status < 0)
1630                         return;
1631                 xprt_connect(task);
1632         }
1633 }
1634
1635 /*
1636  * 4c.  Sort out connect result
1637  */
1638 static void
1639 call_connect_status(struct rpc_task *task)
1640 {
1641         struct rpc_clnt *clnt = task->tk_client;
1642         int status = task->tk_status;
1643
1644         dprint_status(task);
1645
1646         task->tk_status = 0;
1647         if (status >= 0 || status == -EAGAIN) {
1648                 clnt->cl_stats->netreconn++;
1649                 task->tk_action = call_transmit;
1650                 return;
1651         }
1652
1653         trace_rpc_connect_status(task, status);
1654         switch (status) {
1655                 /* if soft mounted, test if we've timed out */
1656         case -ETIMEDOUT:
1657                 task->tk_action = call_timeout;
1658                 break;
1659         default:
1660                 rpc_exit(task, -EIO);
1661         }
1662 }
1663
1664 /*
1665  * 5.   Transmit the RPC request, and wait for reply
1666  */
1667 static void
1668 call_transmit(struct rpc_task *task)
1669 {
1670         dprint_status(task);
1671
1672         task->tk_action = call_status;
1673         if (task->tk_status < 0)
1674                 return;
1675         task->tk_status = xprt_prepare_transmit(task);
1676         if (task->tk_status != 0)
1677                 return;
1678         task->tk_action = call_transmit_status;
1679         /* Encode here so that rpcsec_gss can use correct sequence number. */
1680         if (rpc_task_need_encode(task)) {
1681                 rpc_xdr_encode(task);
1682                 /* Did the encode result in an error condition? */
1683                 if (task->tk_status != 0) {
1684                         /* Was the error nonfatal? */
1685                         if (task->tk_status == -EAGAIN)
1686                                 rpc_delay(task, HZ >> 4);
1687                         else
1688                                 rpc_exit(task, task->tk_status);
1689                         return;
1690                 }
1691         }
1692         xprt_transmit(task);
1693         if (task->tk_status < 0)
1694                 return;
1695         /*
1696          * On success, ensure that we call xprt_end_transmit() before sleeping
1697          * in order to allow access to the socket to other RPC requests.
1698          */
1699         call_transmit_status(task);
1700         if (rpc_reply_expected(task))
1701                 return;
1702         task->tk_action = rpc_exit_task;
1703         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1704 }
1705
1706 /*
1707  * 5a.  Handle cleanup after a transmission
1708  */
1709 static void
1710 call_transmit_status(struct rpc_task *task)
1711 {
1712         task->tk_action = call_status;
1713
1714         /*
1715          * Common case: success.  Force the compiler to put this
1716          * test first.
1717          */
1718         if (task->tk_status == 0) {
1719                 xprt_end_transmit(task);
1720                 rpc_task_force_reencode(task);
1721                 return;
1722         }
1723
1724         switch (task->tk_status) {
1725         case -EAGAIN:
1726                 break;
1727         default:
1728                 dprint_status(task);
1729                 xprt_end_transmit(task);
1730                 rpc_task_force_reencode(task);
1731                 break;
1732                 /*
1733                  * Special cases: if we've been waiting on the
1734                  * socket's write_space() callback, or if the
1735                  * socket just returned a connection error,
1736                  * then hold onto the transport lock.
1737                  */
1738         case -ECONNREFUSED:
1739         case -EHOSTDOWN:
1740         case -EHOSTUNREACH:
1741         case -ENETUNREACH:
1742                 if (RPC_IS_SOFTCONN(task)) {
1743                         xprt_end_transmit(task);
1744                         rpc_exit(task, task->tk_status);
1745                         break;
1746                 }
1747         case -ECONNRESET:
1748         case -ENOTCONN:
1749         case -EPIPE:
1750                 rpc_task_force_reencode(task);
1751         }
1752 }
1753
1754 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1755 /*
1756  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1757  * addition, disconnect on connectivity errors.
1758  */
1759 static void
1760 call_bc_transmit(struct rpc_task *task)
1761 {
1762         struct rpc_rqst *req = task->tk_rqstp;
1763
1764         task->tk_status = xprt_prepare_transmit(task);
1765         if (task->tk_status == -EAGAIN) {
1766                 /*
1767                  * Could not reserve the transport. Try again after the
1768                  * transport is released.
1769                  */
1770                 task->tk_status = 0;
1771                 task->tk_action = call_bc_transmit;
1772                 return;
1773         }
1774
1775         task->tk_action = rpc_exit_task;
1776         if (task->tk_status < 0) {
1777                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1778                         "error: %d\n", task->tk_status);
1779                 return;
1780         }
1781
1782         xprt_transmit(task);
1783         xprt_end_transmit(task);
1784         dprint_status(task);
1785         switch (task->tk_status) {
1786         case 0:
1787                 /* Success */
1788                 break;
1789         case -EHOSTDOWN:
1790         case -EHOSTUNREACH:
1791         case -ENETUNREACH:
1792         case -ETIMEDOUT:
1793                 /*
1794                  * Problem reaching the server.  Disconnect and let the
1795                  * forechannel reestablish the connection.  The server will
1796                  * have to retransmit the backchannel request and we'll
1797                  * reprocess it.  Since these ops are idempotent, there's no
1798                  * need to cache our reply at this time.
1799                  */
1800                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1801                         "error: %d\n", task->tk_status);
1802                 xprt_conditional_disconnect(req->rq_xprt,
1803                         req->rq_connect_cookie);
1804                 break;
1805         default:
1806                 /*
1807                  * We were unable to reply and will have to drop the
1808                  * request.  The server should reconnect and retransmit.
1809                  */
1810                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1811                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1812                         "error: %d\n", task->tk_status);
1813                 break;
1814         }
1815         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1816 }
1817 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1818
1819 /*
1820  * 6.   Sort out the RPC call status
1821  */
1822 static void
1823 call_status(struct rpc_task *task)
1824 {
1825         struct rpc_clnt *clnt = task->tk_client;
1826         struct rpc_rqst *req = task->tk_rqstp;
1827         int             status;
1828
1829         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1830                 task->tk_status = req->rq_reply_bytes_recvd;
1831
1832         dprint_status(task);
1833
1834         status = task->tk_status;
1835         if (status >= 0) {
1836                 task->tk_action = call_decode;
1837                 return;
1838         }
1839
1840         trace_rpc_call_status(task);
1841         task->tk_status = 0;
1842         switch(status) {
1843         case -EHOSTDOWN:
1844         case -EHOSTUNREACH:
1845         case -ENETUNREACH:
1846                 /*
1847                  * Delay any retries for 3 seconds, then handle as if it
1848                  * were a timeout.
1849                  */
1850                 rpc_delay(task, 3*HZ);
1851         case -ETIMEDOUT:
1852                 task->tk_action = call_timeout;
1853                 if (task->tk_client->cl_discrtry)
1854                         xprt_conditional_disconnect(req->rq_xprt,
1855                                         req->rq_connect_cookie);
1856                 break;
1857         case -ECONNRESET:
1858         case -ECONNREFUSED:
1859                 rpc_force_rebind(clnt);
1860                 rpc_delay(task, 3*HZ);
1861         case -EPIPE:
1862         case -ENOTCONN:
1863                 task->tk_action = call_bind;
1864                 break;
1865         case -EAGAIN:
1866                 task->tk_action = call_transmit;
1867                 break;
1868         case -EIO:
1869                 /* shutdown or soft timeout */
1870                 rpc_exit(task, status);
1871                 break;
1872         default:
1873                 if (clnt->cl_chatty)
1874                         printk("%s: RPC call returned error %d\n",
1875                                clnt->cl_protname, -status);
1876                 rpc_exit(task, status);
1877         }
1878 }
1879
1880 /*
1881  * 6a.  Handle RPC timeout
1882  *      We do not release the request slot, so we keep using the
1883  *      same XID for all retransmits.
1884  */
1885 static void
1886 call_timeout(struct rpc_task *task)
1887 {
1888         struct rpc_clnt *clnt = task->tk_client;
1889
1890         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1891                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1892                 goto retry;
1893         }
1894
1895         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1896         task->tk_timeouts++;
1897
1898         if (RPC_IS_SOFTCONN(task)) {
1899                 rpc_exit(task, -ETIMEDOUT);
1900                 return;
1901         }
1902         if (RPC_IS_SOFT(task)) {
1903                 if (clnt->cl_chatty) {
1904                         rcu_read_lock();
1905                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1906                                 clnt->cl_protname,
1907                                 rcu_dereference(clnt->cl_xprt)->servername);
1908                         rcu_read_unlock();
1909                 }
1910                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1911                         rpc_exit(task, -ETIMEDOUT);
1912                 else
1913                         rpc_exit(task, -EIO);
1914                 return;
1915         }
1916
1917         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1918                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1919                 if (clnt->cl_chatty) {
1920                         rcu_read_lock();
1921                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1922                         clnt->cl_protname,
1923                         rcu_dereference(clnt->cl_xprt)->servername);
1924                         rcu_read_unlock();
1925                 }
1926         }
1927         rpc_force_rebind(clnt);
1928         /*
1929          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1930          * event? RFC2203 requires the server to drop all such requests.
1931          */
1932         rpcauth_invalcred(task);
1933
1934 retry:
1935         clnt->cl_stats->rpcretrans++;
1936         task->tk_action = call_bind;
1937         task->tk_status = 0;
1938 }
1939
1940 /*
1941  * 7.   Decode the RPC reply
1942  */
1943 static void
1944 call_decode(struct rpc_task *task)
1945 {
1946         struct rpc_clnt *clnt = task->tk_client;
1947         struct rpc_rqst *req = task->tk_rqstp;
1948         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1949         __be32          *p;
1950
1951         dprint_status(task);
1952
1953         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1954                 if (clnt->cl_chatty) {
1955                         rcu_read_lock();
1956                         printk(KERN_NOTICE "%s: server %s OK\n",
1957                                 clnt->cl_protname,
1958                                 rcu_dereference(clnt->cl_xprt)->servername);
1959                         rcu_read_unlock();
1960                 }
1961                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1962         }
1963
1964         /*
1965          * Ensure that we see all writes made by xprt_complete_rqst()
1966          * before it changed req->rq_reply_bytes_recvd.
1967          */
1968         smp_rmb();
1969         req->rq_rcv_buf.len = req->rq_private_buf.len;
1970
1971         /* Check that the softirq receive buffer is valid */
1972         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1973                                 sizeof(req->rq_rcv_buf)) != 0);
1974
1975         if (req->rq_rcv_buf.len < 12) {
1976                 if (!RPC_IS_SOFT(task)) {
1977                         task->tk_action = call_bind;
1978                         clnt->cl_stats->rpcretrans++;
1979                         goto out_retry;
1980                 }
1981                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1982                                 clnt->cl_protname, task->tk_status);
1983                 task->tk_action = call_timeout;
1984                 goto out_retry;
1985         }
1986
1987         p = rpc_verify_header(task);
1988         if (IS_ERR(p)) {
1989                 if (p == ERR_PTR(-EAGAIN))
1990                         goto out_retry;
1991                 return;
1992         }
1993
1994         task->tk_action = rpc_exit_task;
1995
1996         if (decode) {
1997                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1998                                                       task->tk_msg.rpc_resp);
1999         }
2000         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2001                         task->tk_status);
2002         return;
2003 out_retry:
2004         task->tk_status = 0;
2005         /* Note: rpc_verify_header() may have freed the RPC slot */
2006         if (task->tk_rqstp == req) {
2007                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2008                 if (task->tk_client->cl_discrtry)
2009                         xprt_conditional_disconnect(req->rq_xprt,
2010                                         req->rq_connect_cookie);
2011         }
2012 }
2013
2014 static __be32 *
2015 rpc_encode_header(struct rpc_task *task)
2016 {
2017         struct rpc_clnt *clnt = task->tk_client;
2018         struct rpc_rqst *req = task->tk_rqstp;
2019         __be32          *p = req->rq_svec[0].iov_base;
2020
2021         /* FIXME: check buffer size? */
2022
2023         p = xprt_skip_transport_header(req->rq_xprt, p);
2024         *p++ = req->rq_xid;             /* XID */
2025         *p++ = htonl(RPC_CALL);         /* CALL */
2026         *p++ = htonl(RPC_VERSION);      /* RPC version */
2027         *p++ = htonl(clnt->cl_prog);    /* program number */
2028         *p++ = htonl(clnt->cl_vers);    /* program version */
2029         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2030         p = rpcauth_marshcred(task, p);
2031         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2032         return p;
2033 }
2034
2035 static __be32 *
2036 rpc_verify_header(struct rpc_task *task)
2037 {
2038         struct rpc_clnt *clnt = task->tk_client;
2039         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2040         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2041         __be32  *p = iov->iov_base;
2042         u32 n;
2043         int error = -EACCES;
2044
2045         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2046                 /* RFC-1014 says that the representation of XDR data must be a
2047                  * multiple of four bytes
2048                  * - if it isn't pointer subtraction in the NFS client may give
2049                  *   undefined results
2050                  */
2051                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2052                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2053                        task->tk_rqstp->rq_rcv_buf.len);
2054                 goto out_eio;
2055         }
2056         if ((len -= 3) < 0)
2057                 goto out_overflow;
2058
2059         p += 1; /* skip XID */
2060         if ((n = ntohl(*p++)) != RPC_REPLY) {
2061                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2062                         task->tk_pid, __func__, n);
2063                 goto out_garbage;
2064         }
2065
2066         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2067                 if (--len < 0)
2068                         goto out_overflow;
2069                 switch ((n = ntohl(*p++))) {
2070                 case RPC_AUTH_ERROR:
2071                         break;
2072                 case RPC_MISMATCH:
2073                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2074                                 task->tk_pid, __func__);
2075                         error = -EPROTONOSUPPORT;
2076                         goto out_err;
2077                 default:
2078                         dprintk("RPC: %5u %s: RPC call rejected, "
2079                                 "unknown error: %x\n",
2080                                 task->tk_pid, __func__, n);
2081                         goto out_eio;
2082                 }
2083                 if (--len < 0)
2084                         goto out_overflow;
2085                 switch ((n = ntohl(*p++))) {
2086                 case RPC_AUTH_REJECTEDCRED:
2087                 case RPC_AUTH_REJECTEDVERF:
2088                 case RPCSEC_GSS_CREDPROBLEM:
2089                 case RPCSEC_GSS_CTXPROBLEM:
2090                         if (!task->tk_cred_retry)
2091                                 break;
2092                         task->tk_cred_retry--;
2093                         dprintk("RPC: %5u %s: retry stale creds\n",
2094                                         task->tk_pid, __func__);
2095                         rpcauth_invalcred(task);
2096                         /* Ensure we obtain a new XID! */
2097                         xprt_release(task);
2098                         task->tk_action = call_reserve;
2099                         goto out_retry;
2100                 case RPC_AUTH_BADCRED:
2101                 case RPC_AUTH_BADVERF:
2102                         /* possibly garbled cred/verf? */
2103                         if (!task->tk_garb_retry)
2104                                 break;
2105                         task->tk_garb_retry--;
2106                         dprintk("RPC: %5u %s: retry garbled creds\n",
2107                                         task->tk_pid, __func__);
2108                         task->tk_action = call_bind;
2109                         goto out_retry;
2110                 case RPC_AUTH_TOOWEAK:
2111                         rcu_read_lock();
2112                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2113                                "authentication.\n",
2114                                rcu_dereference(clnt->cl_xprt)->servername);
2115                         rcu_read_unlock();
2116                         break;
2117                 default:
2118                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2119                                         task->tk_pid, __func__, n);
2120                         error = -EIO;
2121                 }
2122                 dprintk("RPC: %5u %s: call rejected %d\n",
2123                                 task->tk_pid, __func__, n);
2124                 goto out_err;
2125         }
2126         if (!(p = rpcauth_checkverf(task, p))) {
2127                 dprintk("RPC: %5u %s: auth check failed\n",
2128                                 task->tk_pid, __func__);
2129                 goto out_garbage;               /* bad verifier, retry */
2130         }
2131         len = p - (__be32 *)iov->iov_base - 1;
2132         if (len < 0)
2133                 goto out_overflow;
2134         switch ((n = ntohl(*p++))) {
2135         case RPC_SUCCESS:
2136                 return p;
2137         case RPC_PROG_UNAVAIL:
2138                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2139                                 "by server %s\n", task->tk_pid, __func__,
2140                                 (unsigned int)clnt->cl_prog,
2141                                 rcu_dereference(clnt->cl_xprt)->servername);
2142                 error = -EPFNOSUPPORT;
2143                 goto out_err;
2144         case RPC_PROG_MISMATCH:
2145                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2146                                 "by server %s\n", task->tk_pid, __func__,
2147                                 (unsigned int)clnt->cl_prog,
2148                                 (unsigned int)clnt->cl_vers,
2149                                 rcu_dereference(clnt->cl_xprt)->servername);
2150                 error = -EPROTONOSUPPORT;
2151                 goto out_err;
2152         case RPC_PROC_UNAVAIL:
2153                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2154                                 "version %u on server %s\n",
2155                                 task->tk_pid, __func__,
2156                                 rpc_proc_name(task),
2157                                 clnt->cl_prog, clnt->cl_vers,
2158                                 rcu_dereference(clnt->cl_xprt)->servername);
2159                 error = -EOPNOTSUPP;
2160                 goto out_err;
2161         case RPC_GARBAGE_ARGS:
2162                 dprintk("RPC: %5u %s: server saw garbage\n",
2163                                 task->tk_pid, __func__);
2164                 break;                  /* retry */
2165         default:
2166                 dprintk("RPC: %5u %s: server accept status: %x\n",
2167                                 task->tk_pid, __func__, n);
2168                 /* Also retry */
2169         }
2170
2171 out_garbage:
2172         clnt->cl_stats->rpcgarbage++;
2173         if (task->tk_garb_retry) {
2174                 task->tk_garb_retry--;
2175                 dprintk("RPC: %5u %s: retrying\n",
2176                                 task->tk_pid, __func__);
2177                 task->tk_action = call_bind;
2178 out_retry:
2179                 return ERR_PTR(-EAGAIN);
2180         }
2181 out_eio:
2182         error = -EIO;
2183 out_err:
2184         rpc_exit(task, error);
2185         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2186                         __func__, error);
2187         return ERR_PTR(error);
2188 out_overflow:
2189         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2190                         __func__);
2191         goto out_garbage;
2192 }
2193
2194 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2195 {
2196 }
2197
2198 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2199 {
2200         return 0;
2201 }
2202
2203 static struct rpc_procinfo rpcproc_null = {
2204         .p_encode = rpcproc_encode_null,
2205         .p_decode = rpcproc_decode_null,
2206 };
2207
2208 static int rpc_ping(struct rpc_clnt *clnt)
2209 {
2210         struct rpc_message msg = {
2211                 .rpc_proc = &rpcproc_null,
2212         };
2213         int err;
2214         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2215         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2216         put_rpccred(msg.rpc_cred);
2217         return err;
2218 }
2219
2220 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2221 {
2222         struct rpc_message msg = {
2223                 .rpc_proc = &rpcproc_null,
2224                 .rpc_cred = cred,
2225         };
2226         struct rpc_task_setup task_setup_data = {
2227                 .rpc_client = clnt,
2228                 .rpc_message = &msg,
2229                 .callback_ops = &rpc_default_ops,
2230                 .flags = flags,
2231         };
2232         return rpc_run_task(&task_setup_data);
2233 }
2234 EXPORT_SYMBOL_GPL(rpc_call_null);
2235
2236 #ifdef RPC_DEBUG
2237 static void rpc_show_header(void)
2238 {
2239         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2240                 "-timeout ---ops--\n");
2241 }
2242
2243 static void rpc_show_task(const struct rpc_clnt *clnt,
2244                           const struct rpc_task *task)
2245 {
2246         const char *rpc_waitq = "none";
2247
2248         if (RPC_IS_QUEUED(task))
2249                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2250
2251         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2252                 task->tk_pid, task->tk_flags, task->tk_status,
2253                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2254                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2255                 task->tk_action, rpc_waitq);
2256 }
2257
2258 void rpc_show_tasks(struct net *net)
2259 {
2260         struct rpc_clnt *clnt;
2261         struct rpc_task *task;
2262         int header = 0;
2263         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2264
2265         spin_lock(&sn->rpc_client_lock);
2266         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2267                 spin_lock(&clnt->cl_lock);
2268                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2269                         if (!header) {
2270                                 rpc_show_header();
2271                                 header++;
2272                         }
2273                         rpc_show_task(clnt, task);
2274                 }
2275                 spin_unlock(&clnt->cl_lock);
2276         }
2277         spin_unlock(&sn->rpc_client_lock);
2278 }
2279 #endif