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/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #ifdef RPC_DEBUG
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         if (clnt->cl_dentry) {
 106                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 107                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 108                 rpc_remove_client_dir(clnt->cl_dentry);
 109         }
 110         clnt->cl_dentry = NULL;
 111 }
 112
 113 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 114 {
 115         struct net *net = rpc_net_ns(clnt);
 116         struct super_block *pipefs_sb;
 117
 118         pipefs_sb = rpc_get_sb_net(net);
 119         if (pipefs_sb) {
 120                 __rpc_clnt_remove_pipedir(clnt);
 121                 rpc_put_sb_net(net);
 122         }
 123 }
 124
 125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 126                                     struct rpc_clnt *clnt,
 127                                     const char *dir_name)
 128 {
 129         static uint32_t clntid;
 130         char name[15];
 131         struct qstr q = { .name = name };
 132         struct dentry *dir, *dentry;
 133         int error;
 134
 135         dir = rpc_d_lookup_sb(sb, dir_name);
 136         if (dir == NULL) {
 137                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 138                 return dir;
 139         }
 140         for (;;) {
 141                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 142                 name[sizeof(name) - 1] = '\0';
 143                 q.hash = full_name_hash(q.name, q.len);
 144                 dentry = rpc_create_client_dir(dir, &q, clnt);
 145                 if (!IS_ERR(dentry))
 146                         break;
 147                 error = PTR_ERR(dentry);
 148                 if (error != -EEXIST) {
 149                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 150                                         " %s/%s, error %d\n",
 151                                         dir_name, name, error);
 152                         break;
 153                 }
 154         }
 155         dput(dir);
 156         return dentry;
 157 }
 158
 159 static int
 160 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 161 {
 162         struct net *net = rpc_net_ns(clnt);
 163         struct super_block *pipefs_sb;
 164         struct dentry *dentry;
 165
 166         clnt->cl_dentry = NULL;
 167         if (dir_name == NULL)
 168                 return 0;
 169         pipefs_sb = rpc_get_sb_net(net);
 170         if (!pipefs_sb)
 171                 return 0;
 172         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 173         rpc_put_sb_net(net);
 174         if (IS_ERR(dentry))
 175                 return PTR_ERR(dentry);
 176         clnt->cl_dentry = dentry;
 177         return 0;
 178 }
 179
 180 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 181 {
 182         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 183             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 184                 return 1;
 185         return 0;
 186 }
 187
 188 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 189                                    struct super_block *sb)
 190 {
 191         struct dentry *dentry;
 192         int err = 0;
 193
 194         switch (event) {
 195         case RPC_PIPEFS_MOUNT:
 196                 dentry = rpc_setup_pipedir_sb(sb, clnt,
 197                                               clnt->cl_program->pipe_dir_name);
 198                 if (!dentry)
 199                         return -ENOENT;
 200                 if (IS_ERR(dentry))
 201                         return PTR_ERR(dentry);
 202                 clnt->cl_dentry = dentry;
 203                 if (clnt->cl_auth->au_ops->pipes_create) {
 204                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 205                         if (err)
 206                                 __rpc_clnt_remove_pipedir(clnt);
 207                 }
 208                 break;
 209         case RPC_PIPEFS_UMOUNT:
 210                 __rpc_clnt_remove_pipedir(clnt);
 211                 break;
 212         default:
 213                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 214                 return -ENOTSUPP;
 215         }
 216         return err;
 217 }
 218
 219 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 220                                 struct super_block *sb)
 221 {
 222         int error = 0;
 223
 224         for (;; clnt = clnt->cl_parent) {
 225                 if (!rpc_clnt_skip_event(clnt, event))
 226                         error = __rpc_clnt_handle_event(clnt, event, sb);
 227                 if (error || clnt == clnt->cl_parent)
 228                         break;
 229         }
 230         return error;
 231 }
 232
 233 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 234 {
 235         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 236         struct rpc_clnt *clnt;
 237
 238         spin_lock(&sn->rpc_client_lock);
 239         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 240                 if (clnt->cl_program->pipe_dir_name == NULL)
 241                         continue;
 242                 if (rpc_clnt_skip_event(clnt, event))
 243                         continue;
 244                 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 245                         continue;
 246                 spin_unlock(&sn->rpc_client_lock);
 247                 return clnt;
 248         }
 249         spin_unlock(&sn->rpc_client_lock);
 250         return NULL;
 251 }
 252
 253 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 254                             void *ptr)
 255 {
 256         struct super_block *sb = ptr;
 257         struct rpc_clnt *clnt;
 258         int error = 0;
 259
 260         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 261                 error = __rpc_pipefs_event(clnt, event, sb);
 262                 rpc_release_client(clnt);
 263                 if (error)
 264                         break;
 265         }
 266         return error;
 267 }
 268
 269 static struct notifier_block rpc_clients_block = {
 270         .notifier_call  = rpc_pipefs_event,
 271         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 272 };
 273
 274 int rpc_clients_notifier_register(void)
 275 {
 276         return rpc_pipefs_notifier_register(&rpc_clients_block);
 277 }
 278
 279 void rpc_clients_notifier_unregister(void)
 280 {
 281         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 282 }
 283
 284 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 285 {
 286         clnt->cl_nodelen = strlen(nodename);
 287         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 288                 clnt->cl_nodelen = UNX_MAXNODENAME;
 289         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 290 }
 291
 292 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 293 {
 294         const struct rpc_program *program = args->program;
 295         const struct rpc_version *version;
 296         struct rpc_clnt         *clnt = NULL;
 297         struct rpc_auth         *auth;
 298         int err;
 299
 300         /* sanity check the name before trying to print it */
 301         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 302                         program->name, args->servername, xprt);
 303
 304         err = rpciod_up();
 305         if (err)
 306                 goto out_no_rpciod;
 307
 308         err = -EINVAL;
 309         if (args->version >= program->nrvers)
 310                 goto out_err;
 311         version = program->version[args->version];
 312         if (version == NULL)
 313                 goto out_err;
 314
 315         err = -ENOMEM;
 316         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 317         if (!clnt)
 318                 goto out_err;
 319         clnt->cl_parent = clnt;
 320
 321         rcu_assign_pointer(clnt->cl_xprt, xprt);
 322         clnt->cl_procinfo = version->procs;
 323         clnt->cl_maxproc  = version->nrprocs;
 324         clnt->cl_protname = program->name;
 325         clnt->cl_prog     = args->prognumber ? : program->number;
 326         clnt->cl_vers     = version->number;
 327         clnt->cl_stats    = program->stats;
 328         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 329         err = -ENOMEM;
 330         if (clnt->cl_metrics == NULL)
 331                 goto out_no_stats;
 332         clnt->cl_program  = program;
 333         INIT_LIST_HEAD(&clnt->cl_tasks);
 334         spin_lock_init(&clnt->cl_lock);
 335
 336         if (!xprt_bound(xprt))
 337                 clnt->cl_autobind = 1;
 338
 339         clnt->cl_timeout = xprt->timeout;
 340         if (args->timeout != NULL) {
 341                 memcpy(&clnt->cl_timeout_default, args->timeout,
 342                                 sizeof(clnt->cl_timeout_default));
 343                 clnt->cl_timeout = &clnt->cl_timeout_default;
 344         }
 345
 346         clnt->cl_rtt = &clnt->cl_rtt_default;
 347         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 348         clnt->cl_principal = NULL;
 349         if (args->client_name) {
 350                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 351                 if (!clnt->cl_principal)
 352                         goto out_no_principal;
 353         }
 354
 355         atomic_set(&clnt->cl_count, 1);
 356
 357         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 358         if (err < 0)
 359                 goto out_no_path;
 360
 361         auth = rpcauth_create(args->authflavor, clnt);
 362         if (IS_ERR(auth)) {
 363                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 364                                 args->authflavor);
 365                 err = PTR_ERR(auth);
 366                 goto out_no_auth;
 367         }
 368
 369         /* save the nodename */
 370         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 371         rpc_register_client(clnt);
 372         return clnt;
 373
 374 out_no_auth:
 375         rpc_clnt_remove_pipedir(clnt);
 376 out_no_path:
 377         kfree(clnt->cl_principal);
 378 out_no_principal:
 379         rpc_free_iostats(clnt->cl_metrics);
 380 out_no_stats:
 381         kfree(clnt);
 382 out_err:
 383         rpciod_down();
 384 out_no_rpciod:
 385         xprt_put(xprt);
 386         return ERR_PTR(err);
 387 }
 388
 389 /**
 390  * rpc_create - create an RPC client and transport with one call
 391  * @args: rpc_clnt create argument structure
 392  *
 393  * Creates and initializes an RPC transport and an RPC client.
 394  *
 395  * It can ping the server in order to determine if it is up, and to see if
 396  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 397  * this behavior so asynchronous tasks can also use rpc_create.
 398  */
 399 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 400 {
 401         struct rpc_xprt *xprt;
 402         struct rpc_clnt *clnt;
 403         struct xprt_create xprtargs = {
 404                 .net = args->net,
 405                 .ident = args->protocol,
 406                 .srcaddr = args->saddress,
 407                 .dstaddr = args->address,
 408                 .addrlen = args->addrsize,
 409                 .servername = args->servername,
 410                 .bc_xprt = args->bc_xprt,
 411         };
 412         char servername[48];
 413
 414         /*
 415          * If the caller chooses not to specify a hostname, whip
 416          * up a string representation of the passed-in address.
 417          */
 418         if (xprtargs.servername == NULL) {
 419                 struct sockaddr_un *sun =
 420                                 (struct sockaddr_un *)args->address;
 421                 struct sockaddr_in *sin =
 422                                 (struct sockaddr_in *)args->address;
 423                 struct sockaddr_in6 *sin6 =
 424                                 (struct sockaddr_in6 *)args->address;
 425
 426                 servername[0] = '\0';
 427                 switch (args->address->sa_family) {
 428                 case AF_LOCAL:
 429                         snprintf(servername, sizeof(servername), "%s",
 430                                  sun->sun_path);
 431                         break;
 432                 case AF_INET:
 433                         snprintf(servername, sizeof(servername), "%pI4",
 434                                  &sin->sin_addr.s_addr);
 435                         break;
 436                 case AF_INET6:
 437                         snprintf(servername, sizeof(servername), "%pI6",
 438                                  &sin6->sin6_addr);
 439                         break;
 440                 default:
 441                         /* caller wants default server name, but
 442                          * address family isn't recognized. */
 443                         return ERR_PTR(-EINVAL);
 444                 }
 445                 xprtargs.servername = servername;
 446         }
 447
 448         xprt = xprt_create_transport(&xprtargs);
 449         if (IS_ERR(xprt))
 450                 return (struct rpc_clnt *)xprt;
 451
 452         /*
 453          * By default, kernel RPC client connects from a reserved port.
 454          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 455          * but it is always enabled for rpciod, which handles the connect
 456          * operation.
 457          */
 458         xprt->resvport = 1;
 459         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 460                 xprt->resvport = 0;
 461
 462         clnt = rpc_new_client(args, xprt);
 463         if (IS_ERR(clnt))
 464                 return clnt;
 465
 466         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 467                 int err = rpc_ping(clnt);
 468                 if (err != 0) {
 469                         rpc_shutdown_client(clnt);
 470                         return ERR_PTR(err);
 471                 }
 472         }
 473
 474         clnt->cl_softrtry = 1;
 475         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 476                 clnt->cl_softrtry = 0;
 477
 478         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 479                 clnt->cl_autobind = 1;
 480         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 481                 clnt->cl_discrtry = 1;
 482         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 483                 clnt->cl_chatty = 1;
 484
 485         return clnt;
 486 }
 487 EXPORT_SYMBOL_GPL(rpc_create);
 488
 489 /*
 490  * This function clones the RPC client structure. It allows us to share the
 491  * same transport while varying parameters such as the authentication
 492  * flavour.
 493  */
 494 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 495                                            struct rpc_clnt *clnt)
 496 {
 497         struct rpc_xprt *xprt;
 498         struct rpc_clnt *new;
 499         int err;
 500
 501         err = -ENOMEM;
 502         rcu_read_lock();
 503         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 504         rcu_read_unlock();
 505         if (xprt == NULL)
 506                 goto out_err;
 507         args->servername = xprt->servername;
 508
 509         new = rpc_new_client(args, xprt);
 510         if (IS_ERR(new)) {
 511                 err = PTR_ERR(new);
 512                 goto out_err;
 513         }
 514
 515         atomic_inc(&clnt->cl_count);
 516         new->cl_parent = clnt;
 517
 518         /* Turn off autobind on clones */
 519         new->cl_autobind = 0;
 520         new->cl_softrtry = clnt->cl_softrtry;
 521         new->cl_discrtry = clnt->cl_discrtry;
 522         new->cl_chatty = clnt->cl_chatty;
 523         return new;
 524
 525 out_err:
 526         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 527         return ERR_PTR(err);
 528 }
 529
 530 /**
 531  * rpc_clone_client - Clone an RPC client structure
 532  *
 533  * @clnt: RPC client whose parameters are copied
 534  *
 535  * Returns a fresh RPC client or an ERR_PTR.
 536  */
 537 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 538 {
 539         struct rpc_create_args args = {
 540                 .program        = clnt->cl_program,
 541                 .prognumber     = clnt->cl_prog,
 542                 .version        = clnt->cl_vers,
 543                 .authflavor     = clnt->cl_auth->au_flavor,
 544                 .client_name    = clnt->cl_principal,
 545         };
 546         return __rpc_clone_client(&args, clnt);
 547 }
 548 EXPORT_SYMBOL_GPL(rpc_clone_client);
 549
 550 /**
 551  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 552  *
 553  * @clnt: RPC client whose parameters are copied
 554  * @flavor: security flavor for new client
 555  *
 556  * Returns a fresh RPC client or an ERR_PTR.
 557  */
 558 struct rpc_clnt *
 559 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 560 {
 561         struct rpc_create_args args = {
 562                 .program        = clnt->cl_program,
 563                 .prognumber     = clnt->cl_prog,
 564                 .version        = clnt->cl_vers,
 565                 .authflavor     = flavor,
 566                 .client_name    = clnt->cl_principal,
 567         };
 568         return __rpc_clone_client(&args, clnt);
 569 }
 570 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 571
 572 /*
 573  * Kill all tasks for the given client.
 574  * XXX: kill their descendants as well?
 575  */
 576 void rpc_killall_tasks(struct rpc_clnt *clnt)
 577 {
 578         struct rpc_task *rovr;
 579
 580
 581         if (list_empty(&clnt->cl_tasks))
 582                 return;
 583         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 584         /*
 585          * Spin lock all_tasks to prevent changes...
 586          */
 587         spin_lock(&clnt->cl_lock);
 588         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 589                 if (!RPC_IS_ACTIVATED(rovr))
 590                         continue;
 591                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 592                         rovr->tk_flags |= RPC_TASK_KILLED;
 593                         rpc_exit(rovr, -EIO);
 594                         if (RPC_IS_QUEUED(rovr))
 595                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 596                                                         rovr);
 597                 }
 598         }
 599         spin_unlock(&clnt->cl_lock);
 600 }
 601 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 602
 603 /*
 604  * Properly shut down an RPC client, terminating all outstanding
 605  * requests.
 606  */
 607 void rpc_shutdown_client(struct rpc_clnt *clnt)
 608 {
 609         might_sleep();
 610
 611         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 612                         clnt->cl_protname,
 613                         rcu_dereference(clnt->cl_xprt)->servername);
 614
 615         while (!list_empty(&clnt->cl_tasks)) {
 616                 rpc_killall_tasks(clnt);
 617                 wait_event_timeout(destroy_wait,
 618                         list_empty(&clnt->cl_tasks), 1*HZ);
 619         }
 620
 621         rpc_release_client(clnt);
 622 }
 623 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 624
 625 /*
 626  * Free an RPC client
 627  */
 628 static void
 629 rpc_free_client(struct rpc_clnt *clnt)
 630 {
 631         dprintk_rcu("RPC:       destroying %s client for %s\n",
 632                         clnt->cl_protname,
 633                         rcu_dereference(clnt->cl_xprt)->servername);
 634         if (clnt->cl_parent != clnt)
 635                 rpc_release_client(clnt->cl_parent);
 636         rpc_unregister_client(clnt);
 637         rpc_clnt_remove_pipedir(clnt);
 638         rpc_free_iostats(clnt->cl_metrics);
 639         kfree(clnt->cl_principal);
 640         clnt->cl_metrics = NULL;
 641         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 642         rpciod_down();
 643         kfree(clnt);
 644 }
 645
 646 /*
 647  * Free an RPC client
 648  */
 649 static void
 650 rpc_free_auth(struct rpc_clnt *clnt)
 651 {
 652         if (clnt->cl_auth == NULL) {
 653                 rpc_free_client(clnt);
 654                 return;
 655         }
 656
 657         /*
 658          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 659          *       release remaining GSS contexts. This mechanism ensures
 660          *       that it can do so safely.
 661          */
 662         atomic_inc(&clnt->cl_count);
 663         rpcauth_release(clnt->cl_auth);
 664         clnt->cl_auth = NULL;
 665         if (atomic_dec_and_test(&clnt->cl_count))
 666                 rpc_free_client(clnt);
 667 }
 668
 669 /*
 670  * Release reference to the RPC client
 671  */
 672 void
 673 rpc_release_client(struct rpc_clnt *clnt)
 674 {
 675         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 676
 677         if (list_empty(&clnt->cl_tasks))
 678                 wake_up(&destroy_wait);
 679         if (atomic_dec_and_test(&clnt->cl_count))
 680                 rpc_free_auth(clnt);
 681 }
 682
 683 /**
 684  * rpc_bind_new_program - bind a new RPC program to an existing client
 685  * @old: old rpc_client
 686  * @program: rpc program to set
 687  * @vers: rpc program version
 688  *
 689  * Clones the rpc client and sets up a new RPC program. This is mainly
 690  * of use for enabling different RPC programs to share the same transport.
 691  * The Sun NFSv2/v3 ACL protocol can do this.
 692  */
 693 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 694                                       const struct rpc_program *program,
 695                                       u32 vers)
 696 {
 697         struct rpc_create_args args = {
 698                 .program        = program,
 699                 .prognumber     = program->number,
 700                 .version        = vers,
 701                 .authflavor     = old->cl_auth->au_flavor,
 702                 .client_name    = old->cl_principal,
 703         };
 704         struct rpc_clnt *clnt;
 705         int err;
 706
 707         clnt = __rpc_clone_client(&args, old);
 708         if (IS_ERR(clnt))
 709                 goto out;
 710         err = rpc_ping(clnt);
 711         if (err != 0) {
 712                 rpc_shutdown_client(clnt);
 713                 clnt = ERR_PTR(err);
 714         }
 715 out:
 716         return clnt;
 717 }
 718 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 719
 720 void rpc_task_release_client(struct rpc_task *task)
 721 {
 722         struct rpc_clnt *clnt = task->tk_client;
 723
 724         if (clnt != NULL) {
 725                 /* Remove from client task list */
 726                 spin_lock(&clnt->cl_lock);
 727                 list_del(&task->tk_task);
 728                 spin_unlock(&clnt->cl_lock);
 729                 task->tk_client = NULL;
 730
 731                 rpc_release_client(clnt);
 732         }
 733 }
 734
 735 static
 736 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 737 {
 738         if (clnt != NULL) {
 739                 rpc_task_release_client(task);
 740                 task->tk_client = clnt;
 741                 atomic_inc(&clnt->cl_count);
 742                 if (clnt->cl_softrtry)
 743                         task->tk_flags |= RPC_TASK_SOFT;
 744                 if (sk_memalloc_socks()) {
 745                         struct rpc_xprt *xprt;
 746
 747                         rcu_read_lock();
 748                         xprt = rcu_dereference(clnt->cl_xprt);
 749                         if (xprt->swapper)
 750                                 task->tk_flags |= RPC_TASK_SWAPPER;
 751                         rcu_read_unlock();
 752                 }
 753                 /* Add to the client's list of all tasks */
 754                 spin_lock(&clnt->cl_lock);
 755                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 756                 spin_unlock(&clnt->cl_lock);
 757         }
 758 }
 759
 760 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 761 {
 762         rpc_task_release_client(task);
 763         rpc_task_set_client(task, clnt);
 764 }
 765 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 766
 767
 768 static void
 769 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 770 {
 771         if (msg != NULL) {
 772                 task->tk_msg.rpc_proc = msg->rpc_proc;
 773                 task->tk_msg.rpc_argp = msg->rpc_argp;
 774                 task->tk_msg.rpc_resp = msg->rpc_resp;
 775                 if (msg->rpc_cred != NULL)
 776                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 777         }
 778 }
 779
 780 /*
 781  * Default callback for async RPC calls
 782  */
 783 static void
 784 rpc_default_callback(struct rpc_task *task, void *data)
 785 {
 786 }
 787
 788 static const struct rpc_call_ops rpc_default_ops = {
 789         .rpc_call_done = rpc_default_callback,
 790 };
 791
 792 /**
 793  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 794  * @task_setup_data: pointer to task initialisation data
 795  */
 796 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 797 {
 798         struct rpc_task *task;
 799
 800         task = rpc_new_task(task_setup_data);
 801         if (IS_ERR(task))
 802                 goto out;
 803
 804         rpc_task_set_client(task, task_setup_data->rpc_client);
 805         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 806
 807         if (task->tk_action == NULL)
 808                 rpc_call_start(task);
 809
 810         atomic_inc(&task->tk_count);
 811         rpc_execute(task);
 812 out:
 813         return task;
 814 }
 815 EXPORT_SYMBOL_GPL(rpc_run_task);
 816
 817 /**
 818  * rpc_call_sync - Perform a synchronous RPC call
 819  * @clnt: pointer to RPC client
 820  * @msg: RPC call parameters
 821  * @flags: RPC call flags
 822  */
 823 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 824 {
 825         struct rpc_task *task;
 826         struct rpc_task_setup task_setup_data = {
 827                 .rpc_client = clnt,
 828                 .rpc_message = msg,
 829                 .callback_ops = &rpc_default_ops,
 830                 .flags = flags,
 831         };
 832         int status;
 833
 834         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 835         if (flags & RPC_TASK_ASYNC) {
 836                 rpc_release_calldata(task_setup_data.callback_ops,
 837                         task_setup_data.callback_data);
 838                 return -EINVAL;
 839         }
 840
 841         task = rpc_run_task(&task_setup_data);
 842         if (IS_ERR(task))
 843                 return PTR_ERR(task);
 844         status = task->tk_status;
 845         rpc_put_task(task);
 846         return status;
 847 }
 848 EXPORT_SYMBOL_GPL(rpc_call_sync);
 849
 850 /**
 851  * rpc_call_async - Perform an asynchronous RPC call
 852  * @clnt: pointer to RPC client
 853  * @msg: RPC call parameters
 854  * @flags: RPC call flags
 855  * @tk_ops: RPC call ops
 856  * @data: user call data
 857  */
 858 int
 859 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 860                const struct rpc_call_ops *tk_ops, void *data)
 861 {
 862         struct rpc_task *task;
 863         struct rpc_task_setup task_setup_data = {
 864                 .rpc_client = clnt,
 865                 .rpc_message = msg,
 866                 .callback_ops = tk_ops,
 867                 .callback_data = data,
 868                 .flags = flags|RPC_TASK_ASYNC,
 869         };
 870
 871         task = rpc_run_task(&task_setup_data);
 872         if (IS_ERR(task))
 873                 return PTR_ERR(task);
 874         rpc_put_task(task);
 875         return 0;
 876 }
 877 EXPORT_SYMBOL_GPL(rpc_call_async);
 878
 879 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 880 /**
 881  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 882  * rpc_execute against it
 883  * @req: RPC request
 884  * @tk_ops: RPC call ops
 885  */
 886 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 887                                 const struct rpc_call_ops *tk_ops)
 888 {
 889         struct rpc_task *task;
 890         struct xdr_buf *xbufp = &req->rq_snd_buf;
 891         struct rpc_task_setup task_setup_data = {
 892                 .callback_ops = tk_ops,
 893         };
 894
 895         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 896         /*
 897          * Create an rpc_task to send the data
 898          */
 899         task = rpc_new_task(&task_setup_data);
 900         if (IS_ERR(task)) {
 901                 xprt_free_bc_request(req);
 902                 goto out;
 903         }
 904         task->tk_rqstp = req;
 905
 906         /*
 907          * Set up the xdr_buf length.
 908          * This also indicates that the buffer is XDR encoded already.
 909          */
 910         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 911                         xbufp->tail[0].iov_len;
 912
 913         task->tk_action = call_bc_transmit;
 914         atomic_inc(&task->tk_count);
 915         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 916         rpc_execute(task);
 917
 918 out:
 919         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 920         return task;
 921 }
 922 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 923
 924 void
 925 rpc_call_start(struct rpc_task *task)
 926 {
 927         task->tk_action = call_start;
 928 }
 929 EXPORT_SYMBOL_GPL(rpc_call_start);
 930
 931 /**
 932  * rpc_peeraddr - extract remote peer address from clnt's xprt
 933  * @clnt: RPC client structure
 934  * @buf: target buffer
 935  * @bufsize: length of target buffer
 936  *
 937  * Returns the number of bytes that are actually in the stored address.
 938  */
 939 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 940 {
 941         size_t bytes;
 942         struct rpc_xprt *xprt;
 943
 944         rcu_read_lock();
 945         xprt = rcu_dereference(clnt->cl_xprt);
 946
 947         bytes = xprt->addrlen;
 948         if (bytes > bufsize)
 949                 bytes = bufsize;
 950         memcpy(buf, &xprt->addr, bytes);
 951         rcu_read_unlock();
 952
 953         return bytes;
 954 }
 955 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 956
 957 /**
 958  * rpc_peeraddr2str - return remote peer address in printable format
 959  * @clnt: RPC client structure
 960  * @format: address format
 961  *
 962  * NB: the lifetime of the memory referenced by the returned pointer is
 963  * the same as the rpc_xprt itself.  As long as the caller uses this
 964  * pointer, it must hold the RCU read lock.
 965  */
 966 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 967                              enum rpc_display_format_t format)
 968 {
 969         struct rpc_xprt *xprt;
 970
 971         xprt = rcu_dereference(clnt->cl_xprt);
 972
 973         if (xprt->address_strings[format] != NULL)
 974                 return xprt->address_strings[format];
 975         else
 976                 return "unprintable";
 977 }
 978 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 979
 980 static const struct sockaddr_in rpc_inaddr_loopback = {
 981         .sin_family             = AF_INET,
 982         .sin_addr.s_addr        = htonl(INADDR_ANY),
 983 };
 984
 985 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 986         .sin6_family            = AF_INET6,
 987         .sin6_addr              = IN6ADDR_ANY_INIT,
 988 };
 989
 990 /*
 991  * Try a getsockname() on a connected datagram socket.  Using a
 992  * connected datagram socket prevents leaving a socket in TIME_WAIT.
 993  * This conserves the ephemeral port number space.
 994  *
 995  * Returns zero and fills in "buf" if successful; otherwise, a
 996  * negative errno is returned.
 997  */
 998 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
 999                         struct sockaddr *buf, int buflen)
1000 {
1001         struct socket *sock;
1002         int err;
1003
1004         err = __sock_create(net, sap->sa_family,
1005                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1006         if (err < 0) {
1007                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1008                 goto out;
1009         }
1010
1011         switch (sap->sa_family) {
1012         case AF_INET:
1013                 err = kernel_bind(sock,
1014                                 (struct sockaddr *)&rpc_inaddr_loopback,
1015                                 sizeof(rpc_inaddr_loopback));
1016                 break;
1017         case AF_INET6:
1018                 err = kernel_bind(sock,
1019                                 (struct sockaddr *)&rpc_in6addr_loopback,
1020                                 sizeof(rpc_in6addr_loopback));
1021                 break;
1022         default:
1023                 err = -EAFNOSUPPORT;
1024                 goto out;
1025         }
1026         if (err < 0) {
1027                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1028                 goto out_release;
1029         }
1030
1031         err = kernel_connect(sock, sap, salen, 0);
1032         if (err < 0) {
1033                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1034                 goto out_release;
1035         }
1036
1037         err = kernel_getsockname(sock, buf, &buflen);
1038         if (err < 0) {
1039                 dprintk("RPC:       getsockname failed (%d)\n", err);
1040                 goto out_release;
1041         }
1042
1043         err = 0;
1044         if (buf->sa_family == AF_INET6) {
1045                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1046                 sin6->sin6_scope_id = 0;
1047         }
1048         dprintk("RPC:       %s succeeded\n", __func__);
1049
1050 out_release:
1051         sock_release(sock);
1052 out:
1053         return err;
1054 }
1055
1056 /*
1057  * Scraping a connected socket failed, so we don't have a useable
1058  * local address.  Fallback: generate an address that will prevent
1059  * the server from calling us back.
1060  *
1061  * Returns zero and fills in "buf" if successful; otherwise, a
1062  * negative errno is returned.
1063  */
1064 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1065 {
1066         switch (family) {
1067         case AF_INET:
1068                 if (buflen < sizeof(rpc_inaddr_loopback))
1069                         return -EINVAL;
1070                 memcpy(buf, &rpc_inaddr_loopback,
1071                                 sizeof(rpc_inaddr_loopback));
1072                 break;
1073         case AF_INET6:
1074                 if (buflen < sizeof(rpc_in6addr_loopback))
1075                         return -EINVAL;
1076                 memcpy(buf, &rpc_in6addr_loopback,
1077                                 sizeof(rpc_in6addr_loopback));
1078         default:
1079                 dprintk("RPC:       %s: address family not supported\n",
1080                         __func__);
1081                 return -EAFNOSUPPORT;
1082         }
1083         dprintk("RPC:       %s: succeeded\n", __func__);
1084         return 0;
1085 }
1086
1087 /**
1088  * rpc_localaddr - discover local endpoint address for an RPC client
1089  * @clnt: RPC client structure
1090  * @buf: target buffer
1091  * @buflen: size of target buffer, in bytes
1092  *
1093  * Returns zero and fills in "buf" and "buflen" if successful;
1094  * otherwise, a negative errno is returned.
1095  *
1096  * This works even if the underlying transport is not currently connected,
1097  * or if the upper layer never previously provided a source address.
1098  *
1099  * The result of this function call is transient: multiple calls in
1100  * succession may give different results, depending on how local
1101  * networking configuration changes over time.
1102  */
1103 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1104 {
1105         struct sockaddr_storage address;
1106         struct sockaddr *sap = (struct sockaddr *)&address;
1107         struct rpc_xprt *xprt;
1108         struct net *net;
1109         size_t salen;
1110         int err;
1111
1112         rcu_read_lock();
1113         xprt = rcu_dereference(clnt->cl_xprt);
1114         salen = xprt->addrlen;
1115         memcpy(sap, &xprt->addr, salen);
1116         net = get_net(xprt->xprt_net);
1117         rcu_read_unlock();
1118
1119         rpc_set_port(sap, 0);
1120         err = rpc_sockname(net, sap, salen, buf, buflen);
1121         put_net(net);
1122         if (err != 0)
1123                 /* Couldn't discover local address, return ANYADDR */
1124                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1125         return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(rpc_localaddr);
1128
1129 void
1130 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1131 {
1132         struct rpc_xprt *xprt;
1133
1134         rcu_read_lock();
1135         xprt = rcu_dereference(clnt->cl_xprt);
1136         if (xprt->ops->set_buffer_size)
1137                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1138         rcu_read_unlock();
1139 }
1140 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1141
1142 /**
1143  * rpc_protocol - Get transport protocol number for an RPC client
1144  * @clnt: RPC client to query
1145  *
1146  */
1147 int rpc_protocol(struct rpc_clnt *clnt)
1148 {
1149         int protocol;
1150
1151         rcu_read_lock();
1152         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1153         rcu_read_unlock();
1154         return protocol;
1155 }
1156 EXPORT_SYMBOL_GPL(rpc_protocol);
1157
1158 /**
1159  * rpc_net_ns - Get the network namespace for this RPC client
1160  * @clnt: RPC client to query
1161  *
1162  */
1163 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1164 {
1165         struct net *ret;
1166
1167         rcu_read_lock();
1168         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1169         rcu_read_unlock();
1170         return ret;
1171 }
1172 EXPORT_SYMBOL_GPL(rpc_net_ns);
1173
1174 /**
1175  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1176  * @clnt: RPC client to query
1177  *
1178  * For stream transports, this is one RPC record fragment (see RFC
1179  * 1831), as we don't support multi-record requests yet.  For datagram
1180  * transports, this is the size of an IP packet minus the IP, UDP, and
1181  * RPC header sizes.
1182  */
1183 size_t rpc_max_payload(struct rpc_clnt *clnt)
1184 {
1185         size_t ret;
1186
1187         rcu_read_lock();
1188         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1189         rcu_read_unlock();
1190         return ret;
1191 }
1192 EXPORT_SYMBOL_GPL(rpc_max_payload);
1193
1194 /**
1195  * rpc_get_timeout - Get timeout for transport in units of HZ
1196  * @clnt: RPC client to query
1197  */
1198 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1199 {
1200         unsigned long ret;
1201
1202         rcu_read_lock();
1203         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1204         rcu_read_unlock();
1205         return ret;
1206 }
1207 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1208
1209 /**
1210  * rpc_force_rebind - force transport to check that remote port is unchanged
1211  * @clnt: client to rebind
1212  *
1213  */
1214 void rpc_force_rebind(struct rpc_clnt *clnt)
1215 {
1216         if (clnt->cl_autobind) {
1217                 rcu_read_lock();
1218                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1219                 rcu_read_unlock();
1220         }
1221 }
1222 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1223
1224 /*
1225  * Restart an (async) RPC call from the call_prepare state.
1226  * Usually called from within the exit handler.
1227  */
1228 int
1229 rpc_restart_call_prepare(struct rpc_task *task)
1230 {
1231         if (RPC_ASSASSINATED(task))
1232                 return 0;
1233         task->tk_action = call_start;
1234         if (task->tk_ops->rpc_call_prepare != NULL)
1235                 task->tk_action = rpc_prepare_task;
1236         return 1;
1237 }
1238 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1239
1240 /*
1241  * Restart an (async) RPC call. Usually called from within the
1242  * exit handler.
1243  */
1244 int
1245 rpc_restart_call(struct rpc_task *task)
1246 {
1247         if (RPC_ASSASSINATED(task))
1248                 return 0;
1249         task->tk_action = call_start;
1250         return 1;
1251 }
1252 EXPORT_SYMBOL_GPL(rpc_restart_call);
1253
1254 #ifdef RPC_DEBUG
1255 static const char *rpc_proc_name(const struct rpc_task *task)
1256 {
1257         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1258
1259         if (proc) {
1260                 if (proc->p_name)
1261                         return proc->p_name;
1262                 else
1263                         return "NULL";
1264         } else
1265                 return "no proc";
1266 }
1267 #endif
1268
1269 /*
1270  * 0.  Initial state
1271  *
1272  *     Other FSM states can be visited zero or more times, but
1273  *     this state is visited exactly once for each RPC.
1274  */
1275 static void
1276 call_start(struct rpc_task *task)
1277 {
1278         struct rpc_clnt *clnt = task->tk_client;
1279
1280         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1281                         clnt->cl_protname, clnt->cl_vers,
1282                         rpc_proc_name(task),
1283                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1284
1285         /* Increment call count */
1286         task->tk_msg.rpc_proc->p_count++;
1287         clnt->cl_stats->rpccnt++;
1288         task->tk_action = call_reserve;
1289 }
1290
1291 /*
1292  * 1.   Reserve an RPC call slot
1293  */
1294 static void
1295 call_reserve(struct rpc_task *task)
1296 {
1297         dprint_status(task);
1298
1299         task->tk_status  = 0;
1300         task->tk_action  = call_reserveresult;
1301         xprt_reserve(task);
1302 }
1303
1304 /*
1305  * 1b.  Grok the result of xprt_reserve()
1306  */
1307 static void
1308 call_reserveresult(struct rpc_task *task)
1309 {
1310         int status = task->tk_status;
1311
1312         dprint_status(task);
1313
1314         /*
1315          * After a call to xprt_reserve(), we must have either
1316          * a request slot or else an error status.
1317          */
1318         task->tk_status = 0;
1319         if (status >= 0) {
1320                 if (task->tk_rqstp) {
1321                         task->tk_action = call_refresh;
1322                         return;
1323                 }
1324
1325                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1326                                 __func__, status);
1327                 rpc_exit(task, -EIO);
1328                 return;
1329         }
1330
1331         /*
1332          * Even though there was an error, we may have acquired
1333          * a request slot somehow.  Make sure not to leak it.
1334          */
1335         if (task->tk_rqstp) {
1336                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1337                                 __func__, status);
1338                 xprt_release(task);
1339         }
1340
1341         switch (status) {
1342         case -ENOMEM:
1343                 rpc_delay(task, HZ >> 2);
1344         case -EAGAIN:   /* woken up; retry */
1345                 task->tk_action = call_reserve;
1346                 return;
1347         case -EIO:      /* probably a shutdown */
1348                 break;
1349         default:
1350                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1351                                 __func__, status);
1352                 break;
1353         }
1354         rpc_exit(task, status);
1355 }
1356
1357 /*
1358  * 2.   Bind and/or refresh the credentials
1359  */
1360 static void
1361 call_refresh(struct rpc_task *task)
1362 {
1363         dprint_status(task);
1364
1365         task->tk_action = call_refreshresult;
1366         task->tk_status = 0;
1367         task->tk_client->cl_stats->rpcauthrefresh++;
1368         rpcauth_refreshcred(task);
1369 }
1370
1371 /*
1372  * 2a.  Process the results of a credential refresh
1373  */
1374 static void
1375 call_refreshresult(struct rpc_task *task)
1376 {
1377         int status = task->tk_status;
1378
1379         dprint_status(task);
1380
1381         task->tk_status = 0;
1382         task->tk_action = call_refresh;
1383         switch (status) {
1384         case 0:
1385                 if (rpcauth_uptodatecred(task))
1386                         task->tk_action = call_allocate;
1387                 return;
1388         case -ETIMEDOUT:
1389                 rpc_delay(task, 3*HZ);
1390         case -EKEYEXPIRED:
1391         case -EAGAIN:
1392                 status = -EACCES;
1393                 if (!task->tk_cred_retry)
1394                         break;
1395                 task->tk_cred_retry--;
1396                 dprintk("RPC: %5u %s: retry refresh creds\n",
1397                                 task->tk_pid, __func__);
1398                 return;
1399         }
1400         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1401                                 task->tk_pid, __func__, status);
1402         rpc_exit(task, status);
1403 }
1404
1405 /*
1406  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1407  *      (Note: buffer memory is freed in xprt_release).
1408  */
1409 static void
1410 call_allocate(struct rpc_task *task)
1411 {
1412         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1413         struct rpc_rqst *req = task->tk_rqstp;
1414         struct rpc_xprt *xprt = req->rq_xprt;
1415         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1416
1417         dprint_status(task);
1418
1419         task->tk_status = 0;
1420         task->tk_action = call_bind;
1421
1422         if (req->rq_buffer)
1423                 return;
1424
1425         if (proc->p_proc != 0) {
1426                 BUG_ON(proc->p_arglen == 0);
1427                 if (proc->p_decode != NULL)
1428                         BUG_ON(proc->p_replen == 0);
1429         }
1430
1431         /*
1432          * Calculate the size (in quads) of the RPC call
1433          * and reply headers, and convert both values
1434          * to byte sizes.
1435          */
1436         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1437         req->rq_callsize <<= 2;
1438         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1439         req->rq_rcvsize <<= 2;
1440
1441         req->rq_buffer = xprt->ops->buf_alloc(task,
1442                                         req->rq_callsize + req->rq_rcvsize);
1443         if (req->rq_buffer != NULL)
1444                 return;
1445
1446         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1447
1448         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1449                 task->tk_action = call_allocate;
1450                 rpc_delay(task, HZ>>4);
1451                 return;
1452         }
1453
1454         rpc_exit(task, -ERESTARTSYS);
1455 }
1456
1457 static inline int
1458 rpc_task_need_encode(struct rpc_task *task)
1459 {
1460         return task->tk_rqstp->rq_snd_buf.len == 0;
1461 }
1462
1463 static inline void
1464 rpc_task_force_reencode(struct rpc_task *task)
1465 {
1466         task->tk_rqstp->rq_snd_buf.len = 0;
1467         task->tk_rqstp->rq_bytes_sent = 0;
1468 }
1469
1470 static inline void
1471 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1472 {
1473         buf->head[0].iov_base = start;
1474         buf->head[0].iov_len = len;
1475         buf->tail[0].iov_len = 0;
1476         buf->page_len = 0;
1477         buf->flags = 0;
1478         buf->len = 0;
1479         buf->buflen = len;
1480 }
1481
1482 /*
1483  * 3.   Encode arguments of an RPC call
1484  */
1485 static void
1486 rpc_xdr_encode(struct rpc_task *task)
1487 {
1488         struct rpc_rqst *req = task->tk_rqstp;
1489         kxdreproc_t     encode;
1490         __be32          *p;
1491
1492         dprint_status(task);
1493
1494         rpc_xdr_buf_init(&req->rq_snd_buf,
1495                          req->rq_buffer,
1496                          req->rq_callsize);
1497         rpc_xdr_buf_init(&req->rq_rcv_buf,
1498                          (char *)req->rq_buffer + req->rq_callsize,
1499                          req->rq_rcvsize);
1500
1501         p = rpc_encode_header(task);
1502         if (p == NULL) {
1503                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1504                 rpc_exit(task, -EIO);
1505                 return;
1506         }
1507
1508         encode = task->tk_msg.rpc_proc->p_encode;
1509         if (encode == NULL)
1510                 return;
1511
1512         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1513                         task->tk_msg.rpc_argp);
1514 }
1515
1516 /*
1517  * 4.   Get the server port number if not yet set
1518  */
1519 static void
1520 call_bind(struct rpc_task *task)
1521 {
1522         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1523
1524         dprint_status(task);
1525
1526         task->tk_action = call_connect;
1527         if (!xprt_bound(xprt)) {
1528                 task->tk_action = call_bind_status;
1529                 task->tk_timeout = xprt->bind_timeout;
1530                 xprt->ops->rpcbind(task);
1531         }
1532 }
1533
1534 /*
1535  * 4a.  Sort out bind result
1536  */
1537 static void
1538 call_bind_status(struct rpc_task *task)
1539 {
1540         int status = -EIO;
1541
1542         if (task->tk_status >= 0) {
1543                 dprint_status(task);
1544                 task->tk_status = 0;
1545                 task->tk_action = call_connect;
1546                 return;
1547         }
1548
1549         trace_rpc_bind_status(task);
1550         switch (task->tk_status) {
1551         case -ENOMEM:
1552                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1553                 rpc_delay(task, HZ >> 2);
1554                 goto retry_timeout;
1555         case -EACCES:
1556                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1557                                 "unavailable\n", task->tk_pid);
1558                 /* fail immediately if this is an RPC ping */
1559                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1560                         status = -EOPNOTSUPP;
1561                         break;
1562                 }
1563                 if (task->tk_rebind_retry == 0)
1564                         break;
1565                 task->tk_rebind_retry--;
1566                 rpc_delay(task, 3*HZ);
1567                 goto retry_timeout;
1568         case -ETIMEDOUT:
1569                 dprintk("RPC: %5u rpcbind request timed out\n",
1570                                 task->tk_pid);
1571                 goto retry_timeout;
1572         case -EPFNOSUPPORT:
1573                 /* server doesn't support any rpcbind version we know of */
1574                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1575                                 task->tk_pid);
1576                 break;
1577         case -EPROTONOSUPPORT:
1578                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1579                                 task->tk_pid);
1580                 task->tk_status = 0;
1581                 task->tk_action = call_bind;
1582                 return;
1583         case -ECONNREFUSED:             /* connection problems */
1584         case -ECONNRESET:
1585         case -ENOTCONN:
1586         case -EHOSTDOWN:
1587         case -EHOSTUNREACH:
1588         case -ENETUNREACH:
1589         case -EPIPE:
1590                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1591                                 task->tk_pid, task->tk_status);
1592                 if (!RPC_IS_SOFTCONN(task)) {
1593                         rpc_delay(task, 5*HZ);
1594                         goto retry_timeout;
1595                 }
1596                 status = task->tk_status;
1597                 break;
1598         default:
1599                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1600                                 task->tk_pid, -task->tk_status);
1601         }
1602
1603         rpc_exit(task, status);
1604         return;
1605
1606 retry_timeout:
1607         task->tk_action = call_timeout;
1608 }
1609
1610 /*
1611  * 4b.  Connect to the RPC server
1612  */
1613 static void
1614 call_connect(struct rpc_task *task)
1615 {
1616         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1617
1618         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1619                         task->tk_pid, xprt,
1620                         (xprt_connected(xprt) ? "is" : "is not"));
1621
1622         task->tk_action = call_transmit;
1623         if (!xprt_connected(xprt)) {
1624                 task->tk_action = call_connect_status;
1625                 if (task->tk_status < 0)
1626                         return;
1627                 xprt_connect(task);
1628         }
1629 }
1630
1631 /*
1632  * 4c.  Sort out connect result
1633  */
1634 static void
1635 call_connect_status(struct rpc_task *task)
1636 {
1637         struct rpc_clnt *clnt = task->tk_client;
1638         int status = task->tk_status;
1639
1640         dprint_status(task);
1641
1642         task->tk_status = 0;
1643         if (status >= 0 || status == -EAGAIN) {
1644                 clnt->cl_stats->netreconn++;
1645                 task->tk_action = call_transmit;
1646                 return;
1647         }
1648
1649         trace_rpc_connect_status(task, status);
1650         switch (status) {
1651                 /* if soft mounted, test if we've timed out */
1652         case -ETIMEDOUT:
1653                 task->tk_action = call_timeout;
1654                 break;
1655         default:
1656                 rpc_exit(task, -EIO);
1657         }
1658 }
1659
1660 /*
1661  * 5.   Transmit the RPC request, and wait for reply
1662  */
1663 static void
1664 call_transmit(struct rpc_task *task)
1665 {
1666         dprint_status(task);
1667
1668         task->tk_action = call_status;
1669         if (task->tk_status < 0)
1670                 return;
1671         task->tk_status = xprt_prepare_transmit(task);
1672         if (task->tk_status != 0)
1673                 return;
1674         task->tk_action = call_transmit_status;
1675         /* Encode here so that rpcsec_gss can use correct sequence number. */
1676         if (rpc_task_need_encode(task)) {
1677                 rpc_xdr_encode(task);
1678                 /* Did the encode result in an error condition? */
1679                 if (task->tk_status != 0) {
1680                         /* Was the error nonfatal? */
1681                         if (task->tk_status == -EAGAIN)
1682                                 rpc_delay(task, HZ >> 4);
1683                         else
1684                                 rpc_exit(task, task->tk_status);
1685                         return;
1686                 }
1687         }
1688         xprt_transmit(task);
1689         if (task->tk_status < 0)
1690                 return;
1691         /*
1692          * On success, ensure that we call xprt_end_transmit() before sleeping
1693          * in order to allow access to the socket to other RPC requests.
1694          */
1695         call_transmit_status(task);
1696         if (rpc_reply_expected(task))
1697                 return;
1698         task->tk_action = rpc_exit_task;
1699         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1700 }
1701
1702 /*
1703  * 5a.  Handle cleanup after a transmission
1704  */
1705 static void
1706 call_transmit_status(struct rpc_task *task)
1707 {
1708         task->tk_action = call_status;
1709
1710         /*
1711          * Common case: success.  Force the compiler to put this
1712          * test first.
1713          */
1714         if (task->tk_status == 0) {
1715                 xprt_end_transmit(task);
1716                 rpc_task_force_reencode(task);
1717                 return;
1718         }
1719
1720         switch (task->tk_status) {
1721         case -EAGAIN:
1722                 break;
1723         default:
1724                 dprint_status(task);
1725                 xprt_end_transmit(task);
1726                 rpc_task_force_reencode(task);
1727                 break;
1728                 /*
1729                  * Special cases: if we've been waiting on the
1730                  * socket's write_space() callback, or if the
1731                  * socket just returned a connection error,
1732                  * then hold onto the transport lock.
1733                  */
1734         case -ECONNREFUSED:
1735         case -EHOSTDOWN:
1736         case -EHOSTUNREACH:
1737         case -ENETUNREACH:
1738                 if (RPC_IS_SOFTCONN(task)) {
1739                         xprt_end_transmit(task);
1740                         rpc_exit(task, task->tk_status);
1741                         break;
1742                 }
1743         case -ECONNRESET:
1744         case -ENOTCONN:
1745         case -EPIPE:
1746                 rpc_task_force_reencode(task);
1747         }
1748 }
1749
1750 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1751 /*
1752  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1753  * addition, disconnect on connectivity errors.
1754  */
1755 static void
1756 call_bc_transmit(struct rpc_task *task)
1757 {
1758         struct rpc_rqst *req = task->tk_rqstp;
1759
1760         task->tk_status = xprt_prepare_transmit(task);
1761         if (task->tk_status == -EAGAIN) {
1762                 /*
1763                  * Could not reserve the transport. Try again after the
1764                  * transport is released.
1765                  */
1766                 task->tk_status = 0;
1767                 task->tk_action = call_bc_transmit;
1768                 return;
1769         }
1770
1771         task->tk_action = rpc_exit_task;
1772         if (task->tk_status < 0) {
1773                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1774                         "error: %d\n", task->tk_status);
1775                 return;
1776         }
1777
1778         xprt_transmit(task);
1779         xprt_end_transmit(task);
1780         dprint_status(task);
1781         switch (task->tk_status) {
1782         case 0:
1783                 /* Success */
1784                 break;
1785         case -EHOSTDOWN:
1786         case -EHOSTUNREACH:
1787         case -ENETUNREACH:
1788         case -ETIMEDOUT:
1789                 /*
1790                  * Problem reaching the server.  Disconnect and let the
1791                  * forechannel reestablish the connection.  The server will
1792                  * have to retransmit the backchannel request and we'll
1793                  * reprocess it.  Since these ops are idempotent, there's no
1794                  * need to cache our reply at this time.
1795                  */
1796                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1797                         "error: %d\n", task->tk_status);
1798                 xprt_conditional_disconnect(req->rq_xprt,
1799                         req->rq_connect_cookie);
1800                 break;
1801         default:
1802                 /*
1803                  * We were unable to reply and will have to drop the
1804                  * request.  The server should reconnect and retransmit.
1805                  */
1806                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1807                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1808                         "error: %d\n", task->tk_status);
1809                 break;
1810         }
1811         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1812 }
1813 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1814
1815 /*
1816  * 6.   Sort out the RPC call status
1817  */
1818 static void
1819 call_status(struct rpc_task *task)
1820 {
1821         struct rpc_clnt *clnt = task->tk_client;
1822         struct rpc_rqst *req = task->tk_rqstp;
1823         int             status;
1824
1825         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1826                 task->tk_status = req->rq_reply_bytes_recvd;
1827
1828         dprint_status(task);
1829
1830         status = task->tk_status;
1831         if (status >= 0) {
1832                 task->tk_action = call_decode;
1833                 return;
1834         }
1835
1836         trace_rpc_call_status(task);
1837         task->tk_status = 0;
1838         switch(status) {
1839         case -EHOSTDOWN:
1840         case -EHOSTUNREACH:
1841         case -ENETUNREACH:
1842                 /*
1843                  * Delay any retries for 3 seconds, then handle as if it
1844                  * were a timeout.
1845                  */
1846                 rpc_delay(task, 3*HZ);
1847         case -ETIMEDOUT:
1848                 task->tk_action = call_timeout;
1849                 if (task->tk_client->cl_discrtry)
1850                         xprt_conditional_disconnect(req->rq_xprt,
1851                                         req->rq_connect_cookie);
1852                 break;
1853         case -ECONNRESET:
1854         case -ECONNREFUSED:
1855                 rpc_force_rebind(clnt);
1856                 rpc_delay(task, 3*HZ);
1857         case -EPIPE:
1858         case -ENOTCONN:
1859                 task->tk_action = call_bind;
1860                 break;
1861         case -EAGAIN:
1862                 task->tk_action = call_transmit;
1863                 break;
1864         case -EIO:
1865                 /* shutdown or soft timeout */
1866                 rpc_exit(task, status);
1867                 break;
1868         default:
1869                 if (clnt->cl_chatty)
1870                         printk("%s: RPC call returned error %d\n",
1871                                clnt->cl_protname, -status);
1872                 rpc_exit(task, status);
1873         }
1874 }
1875
1876 /*
1877  * 6a.  Handle RPC timeout
1878  *      We do not release the request slot, so we keep using the
1879  *      same XID for all retransmits.
1880  */
1881 static void
1882 call_timeout(struct rpc_task *task)
1883 {
1884         struct rpc_clnt *clnt = task->tk_client;
1885
1886         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1887                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1888                 goto retry;
1889         }
1890
1891         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1892         task->tk_timeouts++;
1893
1894         if (RPC_IS_SOFTCONN(task)) {
1895                 rpc_exit(task, -ETIMEDOUT);
1896                 return;
1897         }
1898         if (RPC_IS_SOFT(task)) {
1899                 if (clnt->cl_chatty) {
1900                         rcu_read_lock();
1901                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1902                                 clnt->cl_protname,
1903                                 rcu_dereference(clnt->cl_xprt)->servername);
1904                         rcu_read_unlock();
1905                 }
1906                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1907                         rpc_exit(task, -ETIMEDOUT);
1908                 else
1909                         rpc_exit(task, -EIO);
1910                 return;
1911         }
1912
1913         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1914                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1915                 if (clnt->cl_chatty) {
1916                         rcu_read_lock();
1917                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1918                         clnt->cl_protname,
1919                         rcu_dereference(clnt->cl_xprt)->servername);
1920                         rcu_read_unlock();
1921                 }
1922         }
1923         rpc_force_rebind(clnt);
1924         /*
1925          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1926          * event? RFC2203 requires the server to drop all such requests.
1927          */
1928         rpcauth_invalcred(task);
1929
1930 retry:
1931         clnt->cl_stats->rpcretrans++;
1932         task->tk_action = call_bind;
1933         task->tk_status = 0;
1934 }
1935
1936 /*
1937  * 7.   Decode the RPC reply
1938  */
1939 static void
1940 call_decode(struct rpc_task *task)
1941 {
1942         struct rpc_clnt *clnt = task->tk_client;
1943         struct rpc_rqst *req = task->tk_rqstp;
1944         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1945         __be32          *p;
1946
1947         dprint_status(task);
1948
1949         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1950                 if (clnt->cl_chatty) {
1951                         rcu_read_lock();
1952                         printk(KERN_NOTICE "%s: server %s OK\n",
1953                                 clnt->cl_protname,
1954                                 rcu_dereference(clnt->cl_xprt)->servername);
1955                         rcu_read_unlock();
1956                 }
1957                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1958         }
1959
1960         /*
1961          * Ensure that we see all writes made by xprt_complete_rqst()
1962          * before it changed req->rq_reply_bytes_recvd.
1963          */
1964         smp_rmb();
1965         req->rq_rcv_buf.len = req->rq_private_buf.len;
1966
1967         /* Check that the softirq receive buffer is valid */
1968         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1969                                 sizeof(req->rq_rcv_buf)) != 0);
1970
1971         if (req->rq_rcv_buf.len < 12) {
1972                 if (!RPC_IS_SOFT(task)) {
1973                         task->tk_action = call_bind;
1974                         clnt->cl_stats->rpcretrans++;
1975                         goto out_retry;
1976                 }
1977                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1978                                 clnt->cl_protname, task->tk_status);
1979                 task->tk_action = call_timeout;
1980                 goto out_retry;
1981         }
1982
1983         p = rpc_verify_header(task);
1984         if (IS_ERR(p)) {
1985                 if (p == ERR_PTR(-EAGAIN))
1986                         goto out_retry;
1987                 return;
1988         }
1989
1990         task->tk_action = rpc_exit_task;
1991
1992         if (decode) {
1993                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1994                                                       task->tk_msg.rpc_resp);
1995         }
1996         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1997                         task->tk_status);
1998         return;
1999 out_retry:
2000         task->tk_status = 0;
2001         /* Note: rpc_verify_header() may have freed the RPC slot */
2002         if (task->tk_rqstp == req) {
2003                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2004                 if (task->tk_client->cl_discrtry)
2005                         xprt_conditional_disconnect(req->rq_xprt,
2006                                         req->rq_connect_cookie);
2007         }
2008 }
2009
2010 static __be32 *
2011 rpc_encode_header(struct rpc_task *task)
2012 {
2013         struct rpc_clnt *clnt = task->tk_client;
2014         struct rpc_rqst *req = task->tk_rqstp;
2015         __be32          *p = req->rq_svec[0].iov_base;
2016
2017         /* FIXME: check buffer size? */
2018
2019         p = xprt_skip_transport_header(req->rq_xprt, p);
2020         *p++ = req->rq_xid;             /* XID */
2021         *p++ = htonl(RPC_CALL);         /* CALL */
2022         *p++ = htonl(RPC_VERSION);      /* RPC version */
2023         *p++ = htonl(clnt->cl_prog);    /* program number */
2024         *p++ = htonl(clnt->cl_vers);    /* program version */
2025         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2026         p = rpcauth_marshcred(task, p);
2027         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2028         return p;
2029 }
2030
2031 static __be32 *
2032 rpc_verify_header(struct rpc_task *task)
2033 {
2034         struct rpc_clnt *clnt = task->tk_client;
2035         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2036         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2037         __be32  *p = iov->iov_base;
2038         u32 n;
2039         int error = -EACCES;
2040
2041         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2042                 /* RFC-1014 says that the representation of XDR data must be a
2043                  * multiple of four bytes
2044                  * - if it isn't pointer subtraction in the NFS client may give
2045                  *   undefined results
2046                  */
2047                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2048                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2049                        task->tk_rqstp->rq_rcv_buf.len);
2050                 goto out_eio;
2051         }
2052         if ((len -= 3) < 0)
2053                 goto out_overflow;
2054
2055         p += 1; /* skip XID */
2056         if ((n = ntohl(*p++)) != RPC_REPLY) {
2057                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2058                         task->tk_pid, __func__, n);
2059                 goto out_garbage;
2060         }
2061
2062         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2063                 if (--len < 0)
2064                         goto out_overflow;
2065                 switch ((n = ntohl(*p++))) {
2066                 case RPC_AUTH_ERROR:
2067                         break;
2068                 case RPC_MISMATCH:
2069                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2070                                 task->tk_pid, __func__);
2071                         error = -EPROTONOSUPPORT;
2072                         goto out_err;
2073                 default:
2074                         dprintk("RPC: %5u %s: RPC call rejected, "
2075                                 "unknown error: %x\n",
2076                                 task->tk_pid, __func__, n);
2077                         goto out_eio;
2078                 }
2079                 if (--len < 0)
2080                         goto out_overflow;
2081                 switch ((n = ntohl(*p++))) {
2082                 case RPC_AUTH_REJECTEDCRED:
2083                 case RPC_AUTH_REJECTEDVERF:
2084                 case RPCSEC_GSS_CREDPROBLEM:
2085                 case RPCSEC_GSS_CTXPROBLEM:
2086                         if (!task->tk_cred_retry)
2087                                 break;
2088                         task->tk_cred_retry--;
2089                         dprintk("RPC: %5u %s: retry stale creds\n",
2090                                         task->tk_pid, __func__);
2091                         rpcauth_invalcred(task);
2092                         /* Ensure we obtain a new XID! */
2093                         xprt_release(task);
2094                         task->tk_action = call_reserve;
2095                         goto out_retry;
2096                 case RPC_AUTH_BADCRED:
2097                 case RPC_AUTH_BADVERF:
2098                         /* possibly garbled cred/verf? */
2099                         if (!task->tk_garb_retry)
2100                                 break;
2101                         task->tk_garb_retry--;
2102                         dprintk("RPC: %5u %s: retry garbled creds\n",
2103                                         task->tk_pid, __func__);
2104                         task->tk_action = call_bind;
2105                         goto out_retry;
2106                 case RPC_AUTH_TOOWEAK:
2107                         rcu_read_lock();
2108                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2109                                "authentication.\n",
2110                                rcu_dereference(clnt->cl_xprt)->servername);
2111                         rcu_read_unlock();
2112                         break;
2113                 default:
2114                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2115                                         task->tk_pid, __func__, n);
2116                         error = -EIO;
2117                 }
2118                 dprintk("RPC: %5u %s: call rejected %d\n",
2119                                 task->tk_pid, __func__, n);
2120                 goto out_err;
2121         }
2122         if (!(p = rpcauth_checkverf(task, p))) {
2123                 dprintk("RPC: %5u %s: auth check failed\n",
2124                                 task->tk_pid, __func__);
2125                 goto out_garbage;               /* bad verifier, retry */
2126         }
2127         len = p - (__be32 *)iov->iov_base - 1;
2128         if (len < 0)
2129                 goto out_overflow;
2130         switch ((n = ntohl(*p++))) {
2131         case RPC_SUCCESS:
2132                 return p;
2133         case RPC_PROG_UNAVAIL:
2134                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2135                                 "by server %s\n", task->tk_pid, __func__,
2136                                 (unsigned int)clnt->cl_prog,
2137                                 rcu_dereference(clnt->cl_xprt)->servername);
2138                 error = -EPFNOSUPPORT;
2139                 goto out_err;
2140         case RPC_PROG_MISMATCH:
2141                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2142                                 "by server %s\n", task->tk_pid, __func__,
2143                                 (unsigned int)clnt->cl_prog,
2144                                 (unsigned int)clnt->cl_vers,
2145                                 rcu_dereference(clnt->cl_xprt)->servername);
2146                 error = -EPROTONOSUPPORT;
2147                 goto out_err;
2148         case RPC_PROC_UNAVAIL:
2149                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2150                                 "version %u on server %s\n",
2151                                 task->tk_pid, __func__,
2152                                 rpc_proc_name(task),
2153                                 clnt->cl_prog, clnt->cl_vers,
2154                                 rcu_dereference(clnt->cl_xprt)->servername);
2155                 error = -EOPNOTSUPP;
2156                 goto out_err;
2157         case RPC_GARBAGE_ARGS:
2158                 dprintk("RPC: %5u %s: server saw garbage\n",
2159                                 task->tk_pid, __func__);
2160                 break;                  /* retry */
2161         default:
2162                 dprintk("RPC: %5u %s: server accept status: %x\n",
2163                                 task->tk_pid, __func__, n);
2164                 /* Also retry */
2165         }
2166
2167 out_garbage:
2168         clnt->cl_stats->rpcgarbage++;
2169         if (task->tk_garb_retry) {
2170                 task->tk_garb_retry--;
2171                 dprintk("RPC: %5u %s: retrying\n",
2172                                 task->tk_pid, __func__);
2173                 task->tk_action = call_bind;
2174 out_retry:
2175                 return ERR_PTR(-EAGAIN);
2176         }
2177 out_eio:
2178         error = -EIO;
2179 out_err:
2180         rpc_exit(task, error);
2181         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2182                         __func__, error);
2183         return ERR_PTR(error);
2184 out_overflow:
2185         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2186                         __func__);
2187         goto out_garbage;
2188 }
2189
2190 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2191 {
2192 }
2193
2194 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2195 {
2196         return 0;
2197 }
2198
2199 static struct rpc_procinfo rpcproc_null = {
2200         .p_encode = rpcproc_encode_null,
2201         .p_decode = rpcproc_decode_null,
2202 };
2203
2204 static int rpc_ping(struct rpc_clnt *clnt)
2205 {
2206         struct rpc_message msg = {
2207                 .rpc_proc = &rpcproc_null,
2208         };
2209         int err;
2210         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2211         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2212         put_rpccred(msg.rpc_cred);
2213         return err;
2214 }
2215
2216 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2217 {
2218         struct rpc_message msg = {
2219                 .rpc_proc = &rpcproc_null,
2220                 .rpc_cred = cred,
2221         };
2222         struct rpc_task_setup task_setup_data = {
2223                 .rpc_client = clnt,
2224                 .rpc_message = &msg,
2225                 .callback_ops = &rpc_default_ops,
2226                 .flags = flags,
2227         };
2228         return rpc_run_task(&task_setup_data);
2229 }
2230 EXPORT_SYMBOL_GPL(rpc_call_null);
2231
2232 #ifdef RPC_DEBUG
2233 static void rpc_show_header(void)
2234 {
2235         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2236                 "-timeout ---ops--\n");
2237 }
2238
2239 static void rpc_show_task(const struct rpc_clnt *clnt,
2240                           const struct rpc_task *task)
2241 {
2242         const char *rpc_waitq = "none";
2243
2244         if (RPC_IS_QUEUED(task))
2245                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2246
2247         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2248                 task->tk_pid, task->tk_flags, task->tk_status,
2249                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2250                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2251                 task->tk_action, rpc_waitq);
2252 }
2253
2254 void rpc_show_tasks(struct net *net)
2255 {
2256         struct rpc_clnt *clnt;
2257         struct rpc_task *task;
2258         int header = 0;
2259         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2260
2261         spin_lock(&sn->rpc_client_lock);
2262         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2263                 spin_lock(&clnt->cl_lock);
2264                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2265                         if (!header) {
2266                                 rpc_show_header();
2267                                 header++;
2268                         }
2269                         rpc_show_task(clnt, task);
2270                 }
2271                 spin_unlock(&clnt->cl_lock);
2272         }
2273         spin_unlock(&sn->rpc_client_lock);
2274 }
2275 #endif