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