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