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         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 415                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 416         /*
 417          * If the caller chooses not to specify a hostname, whip
 418          * up a string representation of the passed-in address.
 419          */
 420         if (xprtargs.servername == NULL) {
 421                 struct sockaddr_un *sun =
 422                                 (struct sockaddr_un *)args->address;
 423                 struct sockaddr_in *sin =
 424                                 (struct sockaddr_in *)args->address;
 425                 struct sockaddr_in6 *sin6 =
 426                                 (struct sockaddr_in6 *)args->address;
 427
 428                 servername[0] = '\0';
 429                 switch (args->address->sa_family) {
 430                 case AF_LOCAL:
 431                         snprintf(servername, sizeof(servername), "%s",
 432                                  sun->sun_path);
 433                         break;
 434                 case AF_INET:
 435                         snprintf(servername, sizeof(servername), "%pI4",
 436                                  &sin->sin_addr.s_addr);
 437                         break;
 438                 case AF_INET6:
 439                         snprintf(servername, sizeof(servername), "%pI6",
 440                                  &sin6->sin6_addr);
 441                         break;
 442                 default:
 443                         /* caller wants default server name, but
 444                          * address family isn't recognized. */
 445                         return ERR_PTR(-EINVAL);
 446                 }
 447                 xprtargs.servername = servername;
 448         }
 449
 450         xprt = xprt_create_transport(&xprtargs);
 451         if (IS_ERR(xprt))
 452                 return (struct rpc_clnt *)xprt;
 453
 454         /*
 455          * By default, kernel RPC client connects from a reserved port.
 456          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 457          * but it is always enabled for rpciod, which handles the connect
 458          * operation.
 459          */
 460         xprt->resvport = 1;
 461         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 462                 xprt->resvport = 0;
 463
 464         clnt = rpc_new_client(args, xprt);
 465         if (IS_ERR(clnt))
 466                 return clnt;
 467
 468         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 469                 int err = rpc_ping(clnt);
 470                 if (err != 0) {
 471                         rpc_shutdown_client(clnt);
 472                         return ERR_PTR(err);
 473                 }
 474         }
 475
 476         clnt->cl_softrtry = 1;
 477         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 478                 clnt->cl_softrtry = 0;
 479
 480         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 481                 clnt->cl_autobind = 1;
 482         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 483                 clnt->cl_discrtry = 1;
 484         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 485                 clnt->cl_chatty = 1;
 486
 487         return clnt;
 488 }
 489 EXPORT_SYMBOL_GPL(rpc_create);
 490
 491 /*
 492  * This function clones the RPC client structure. It allows us to share the
 493  * same transport while varying parameters such as the authentication
 494  * flavour.
 495  */
 496 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 497                                            struct rpc_clnt *clnt)
 498 {
 499         struct rpc_xprt *xprt;
 500         struct rpc_clnt *new;
 501         int err;
 502
 503         err = -ENOMEM;
 504         rcu_read_lock();
 505         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 506         rcu_read_unlock();
 507         if (xprt == NULL)
 508                 goto out_err;
 509         args->servername = xprt->servername;
 510
 511         new = rpc_new_client(args, xprt);
 512         if (IS_ERR(new)) {
 513                 err = PTR_ERR(new);
 514                 goto out_err;
 515         }
 516
 517         atomic_inc(&clnt->cl_count);
 518         new->cl_parent = clnt;
 519
 520         /* Turn off autobind on clones */
 521         new->cl_autobind = 0;
 522         new->cl_softrtry = clnt->cl_softrtry;
 523         new->cl_discrtry = clnt->cl_discrtry;
 524         new->cl_chatty = clnt->cl_chatty;
 525         return new;
 526
 527 out_err:
 528         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 529         return ERR_PTR(err);
 530 }
 531
 532 /**
 533  * rpc_clone_client - Clone an RPC client structure
 534  *
 535  * @clnt: RPC client whose parameters are copied
 536  *
 537  * Returns a fresh RPC client or an ERR_PTR.
 538  */
 539 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 540 {
 541         struct rpc_create_args args = {
 542                 .program        = clnt->cl_program,
 543                 .prognumber     = clnt->cl_prog,
 544                 .version        = clnt->cl_vers,
 545                 .authflavor     = clnt->cl_auth->au_flavor,
 546                 .client_name    = clnt->cl_principal,
 547         };
 548         return __rpc_clone_client(&args, clnt);
 549 }
 550 EXPORT_SYMBOL_GPL(rpc_clone_client);
 551
 552 /**
 553  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 554  *
 555  * @clnt: RPC client whose parameters are copied
 556  * @flavor: security flavor for new client
 557  *
 558  * Returns a fresh RPC client or an ERR_PTR.
 559  */
 560 struct rpc_clnt *
 561 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 562 {
 563         struct rpc_create_args args = {
 564                 .program        = clnt->cl_program,
 565                 .prognumber     = clnt->cl_prog,
 566                 .version        = clnt->cl_vers,
 567                 .authflavor     = flavor,
 568                 .client_name    = clnt->cl_principal,
 569         };
 570         return __rpc_clone_client(&args, clnt);
 571 }
 572 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 573
 574 /*
 575  * Kill all tasks for the given client.
 576  * XXX: kill their descendants as well?
 577  */
 578 void rpc_killall_tasks(struct rpc_clnt *clnt)
 579 {
 580         struct rpc_task *rovr;
 581
 582
 583         if (list_empty(&clnt->cl_tasks))
 584                 return;
 585         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 586         /*
 587          * Spin lock all_tasks to prevent changes...
 588          */
 589         spin_lock(&clnt->cl_lock);
 590         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 591                 if (!RPC_IS_ACTIVATED(rovr))
 592                         continue;
 593                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 594                         rovr->tk_flags |= RPC_TASK_KILLED;
 595                         rpc_exit(rovr, -EIO);
 596                         if (RPC_IS_QUEUED(rovr))
 597                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 598                                                         rovr);
 599                 }
 600         }
 601         spin_unlock(&clnt->cl_lock);
 602 }
 603 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 604
 605 /*
 606  * Properly shut down an RPC client, terminating all outstanding
 607  * requests.
 608  */
 609 void rpc_shutdown_client(struct rpc_clnt *clnt)
 610 {
 611         might_sleep();
 612
 613         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 614                         clnt->cl_protname,
 615                         rcu_dereference(clnt->cl_xprt)->servername);
 616
 617         while (!list_empty(&clnt->cl_tasks)) {
 618                 rpc_killall_tasks(clnt);
 619                 wait_event_timeout(destroy_wait,
 620                         list_empty(&clnt->cl_tasks), 1*HZ);
 621         }
 622
 623         rpc_release_client(clnt);
 624 }
 625 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 626
 627 /*
 628  * Free an RPC client
 629  */
 630 static void
 631 rpc_free_client(struct rpc_clnt *clnt)
 632 {
 633         dprintk_rcu("RPC:       destroying %s client for %s\n",
 634                         clnt->cl_protname,
 635                         rcu_dereference(clnt->cl_xprt)->servername);
 636         if (clnt->cl_parent != clnt)
 637                 rpc_release_client(clnt->cl_parent);
 638         rpc_unregister_client(clnt);
 639         rpc_clnt_remove_pipedir(clnt);
 640         rpc_free_iostats(clnt->cl_metrics);
 641         kfree(clnt->cl_principal);
 642         clnt->cl_metrics = NULL;
 643         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 644         rpciod_down();
 645         kfree(clnt);
 646 }
 647
 648 /*
 649  * Free an RPC client
 650  */
 651 static void
 652 rpc_free_auth(struct rpc_clnt *clnt)
 653 {
 654         if (clnt->cl_auth == NULL) {
 655                 rpc_free_client(clnt);
 656                 return;
 657         }
 658
 659         /*
 660          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 661          *       release remaining GSS contexts. This mechanism ensures
 662          *       that it can do so safely.
 663          */
 664         atomic_inc(&clnt->cl_count);
 665         rpcauth_release(clnt->cl_auth);
 666         clnt->cl_auth = NULL;
 667         if (atomic_dec_and_test(&clnt->cl_count))
 668                 rpc_free_client(clnt);
 669 }
 670
 671 /*
 672  * Release reference to the RPC client
 673  */
 674 void
 675 rpc_release_client(struct rpc_clnt *clnt)
 676 {
 677         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 678
 679         if (list_empty(&clnt->cl_tasks))
 680                 wake_up(&destroy_wait);
 681         if (atomic_dec_and_test(&clnt->cl_count))
 682                 rpc_free_auth(clnt);
 683 }
 684
 685 /**
 686  * rpc_bind_new_program - bind a new RPC program to an existing client
 687  * @old: old rpc_client
 688  * @program: rpc program to set
 689  * @vers: rpc program version
 690  *
 691  * Clones the rpc client and sets up a new RPC program. This is mainly
 692  * of use for enabling different RPC programs to share the same transport.
 693  * The Sun NFSv2/v3 ACL protocol can do this.
 694  */
 695 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 696                                       const struct rpc_program *program,
 697                                       u32 vers)
 698 {
 699         struct rpc_create_args args = {
 700                 .program        = program,
 701                 .prognumber     = program->number,
 702                 .version        = vers,
 703                 .authflavor     = old->cl_auth->au_flavor,
 704                 .client_name    = old->cl_principal,
 705         };
 706         struct rpc_clnt *clnt;
 707         int err;
 708
 709         clnt = __rpc_clone_client(&args, old);
 710         if (IS_ERR(clnt))
 711                 goto out;
 712         err = rpc_ping(clnt);
 713         if (err != 0) {
 714                 rpc_shutdown_client(clnt);
 715                 clnt = ERR_PTR(err);
 716         }
 717 out:
 718         return clnt;
 719 }
 720 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 721
 722 void rpc_task_release_client(struct rpc_task *task)
 723 {
 724         struct rpc_clnt *clnt = task->tk_client;
 725
 726         if (clnt != NULL) {
 727                 /* Remove from client task list */
 728                 spin_lock(&clnt->cl_lock);
 729                 list_del(&task->tk_task);
 730                 spin_unlock(&clnt->cl_lock);
 731                 task->tk_client = NULL;
 732
 733                 rpc_release_client(clnt);
 734         }
 735 }
 736
 737 static
 738 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 739 {
 740         if (clnt != NULL) {
 741                 rpc_task_release_client(task);
 742                 task->tk_client = clnt;
 743                 atomic_inc(&clnt->cl_count);
 744                 if (clnt->cl_softrtry)
 745                         task->tk_flags |= RPC_TASK_SOFT;
 746                 if (sk_memalloc_socks()) {
 747                         struct rpc_xprt *xprt;
 748
 749                         rcu_read_lock();
 750                         xprt = rcu_dereference(clnt->cl_xprt);
 751                         if (xprt->swapper)
 752                                 task->tk_flags |= RPC_TASK_SWAPPER;
 753                         rcu_read_unlock();
 754                 }
 755                 /* Add to the client's list of all tasks */
 756                 spin_lock(&clnt->cl_lock);
 757                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 758                 spin_unlock(&clnt->cl_lock);
 759         }
 760 }
 761
 762 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 763 {
 764         rpc_task_release_client(task);
 765         rpc_task_set_client(task, clnt);
 766 }
 767 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 768
 769
 770 static void
 771 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 772 {
 773         if (msg != NULL) {
 774                 task->tk_msg.rpc_proc = msg->rpc_proc;
 775                 task->tk_msg.rpc_argp = msg->rpc_argp;
 776                 task->tk_msg.rpc_resp = msg->rpc_resp;
 777                 if (msg->rpc_cred != NULL)
 778                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 779         }
 780 }
 781
 782 /*
 783  * Default callback for async RPC calls
 784  */
 785 static void
 786 rpc_default_callback(struct rpc_task *task, void *data)
 787 {
 788 }
 789
 790 static const struct rpc_call_ops rpc_default_ops = {
 791         .rpc_call_done = rpc_default_callback,
 792 };
 793
 794 /**
 795  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 796  * @task_setup_data: pointer to task initialisation data
 797  */
 798 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 799 {
 800         struct rpc_task *task;
 801
 802         task = rpc_new_task(task_setup_data);
 803         if (IS_ERR(task))
 804                 goto out;
 805
 806         rpc_task_set_client(task, task_setup_data->rpc_client);
 807         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 808
 809         if (task->tk_action == NULL)
 810                 rpc_call_start(task);
 811
 812         atomic_inc(&task->tk_count);
 813         rpc_execute(task);
 814 out:
 815         return task;
 816 }
 817 EXPORT_SYMBOL_GPL(rpc_run_task);
 818
 819 /**
 820  * rpc_call_sync - Perform a synchronous RPC call
 821  * @clnt: pointer to RPC client
 822  * @msg: RPC call parameters
 823  * @flags: RPC call flags
 824  */
 825 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 826 {
 827         struct rpc_task *task;
 828         struct rpc_task_setup task_setup_data = {
 829                 .rpc_client = clnt,
 830                 .rpc_message = msg,
 831                 .callback_ops = &rpc_default_ops,
 832                 .flags = flags,
 833         };
 834         int status;
 835
 836         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 837         if (flags & RPC_TASK_ASYNC) {
 838                 rpc_release_calldata(task_setup_data.callback_ops,
 839                         task_setup_data.callback_data);
 840                 return -EINVAL;
 841         }
 842
 843         task = rpc_run_task(&task_setup_data);
 844         if (IS_ERR(task))
 845                 return PTR_ERR(task);
 846         status = task->tk_status;
 847         rpc_put_task(task);
 848         return status;
 849 }
 850 EXPORT_SYMBOL_GPL(rpc_call_sync);
 851
 852 /**
 853  * rpc_call_async - Perform an asynchronous RPC call
 854  * @clnt: pointer to RPC client
 855  * @msg: RPC call parameters
 856  * @flags: RPC call flags
 857  * @tk_ops: RPC call ops
 858  * @data: user call data
 859  */
 860 int
 861 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 862                const struct rpc_call_ops *tk_ops, void *data)
 863 {
 864         struct rpc_task *task;
 865         struct rpc_task_setup task_setup_data = {
 866                 .rpc_client = clnt,
 867                 .rpc_message = msg,
 868                 .callback_ops = tk_ops,
 869                 .callback_data = data,
 870                 .flags = flags|RPC_TASK_ASYNC,
 871         };
 872
 873         task = rpc_run_task(&task_setup_data);
 874         if (IS_ERR(task))
 875                 return PTR_ERR(task);
 876         rpc_put_task(task);
 877         return 0;
 878 }
 879 EXPORT_SYMBOL_GPL(rpc_call_async);
 880
 881 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 882 /**
 883  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 884  * rpc_execute against it
 885  * @req: RPC request
 886  * @tk_ops: RPC call ops
 887  */
 888 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 889                                 const struct rpc_call_ops *tk_ops)
 890 {
 891         struct rpc_task *task;
 892         struct xdr_buf *xbufp = &req->rq_snd_buf;
 893         struct rpc_task_setup task_setup_data = {
 894                 .callback_ops = tk_ops,
 895         };
 896
 897         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 898         /*
 899          * Create an rpc_task to send the data
 900          */
 901         task = rpc_new_task(&task_setup_data);
 902         if (IS_ERR(task)) {
 903                 xprt_free_bc_request(req);
 904                 goto out;
 905         }
 906         task->tk_rqstp = req;
 907
 908         /*
 909          * Set up the xdr_buf length.
 910          * This also indicates that the buffer is XDR encoded already.
 911          */
 912         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 913                         xbufp->tail[0].iov_len;
 914
 915         task->tk_action = call_bc_transmit;
 916         atomic_inc(&task->tk_count);
 917         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 918         rpc_execute(task);
 919
 920 out:
 921         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 922         return task;
 923 }
 924 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 925
 926 void
 927 rpc_call_start(struct rpc_task *task)
 928 {
 929         task->tk_action = call_start;
 930 }
 931 EXPORT_SYMBOL_GPL(rpc_call_start);
 932
 933 /**
 934  * rpc_peeraddr - extract remote peer address from clnt's xprt
 935  * @clnt: RPC client structure
 936  * @buf: target buffer
 937  * @bufsize: length of target buffer
 938  *
 939  * Returns the number of bytes that are actually in the stored address.
 940  */
 941 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 942 {
 943         size_t bytes;
 944         struct rpc_xprt *xprt;
 945
 946         rcu_read_lock();
 947         xprt = rcu_dereference(clnt->cl_xprt);
 948
 949         bytes = xprt->addrlen;
 950         if (bytes > bufsize)
 951                 bytes = bufsize;
 952         memcpy(buf, &xprt->addr, bytes);
 953         rcu_read_unlock();
 954
 955         return bytes;
 956 }
 957 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 958
 959 /**
 960  * rpc_peeraddr2str - return remote peer address in printable format
 961  * @clnt: RPC client structure
 962  * @format: address format
 963  *
 964  * NB: the lifetime of the memory referenced by the returned pointer is
 965  * the same as the rpc_xprt itself.  As long as the caller uses this
 966  * pointer, it must hold the RCU read lock.
 967  */
 968 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 969                              enum rpc_display_format_t format)
 970 {
 971         struct rpc_xprt *xprt;
 972
 973         xprt = rcu_dereference(clnt->cl_xprt);
 974
 975         if (xprt->address_strings[format] != NULL)
 976                 return xprt->address_strings[format];
 977         else
 978                 return "unprintable";
 979 }
 980 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 981
 982 static const struct sockaddr_in rpc_inaddr_loopback = {
 983         .sin_family             = AF_INET,
 984         .sin_addr.s_addr        = htonl(INADDR_ANY),
 985 };
 986
 987 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 988         .sin6_family            = AF_INET6,
 989         .sin6_addr              = IN6ADDR_ANY_INIT,
 990 };
 991
 992 /*
 993  * Try a getsockname() on a connected datagram socket.  Using a
 994  * connected datagram socket prevents leaving a socket in TIME_WAIT.
 995  * This conserves the ephemeral port number space.
 996  *
 997  * Returns zero and fills in "buf" if successful; otherwise, a
 998  * negative errno is returned.
 999  */
1000 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1001                         struct sockaddr *buf, int buflen)
1002 {
1003         struct socket *sock;
1004         int err;
1005
1006         err = __sock_create(net, sap->sa_family,
1007                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1008         if (err < 0) {
1009                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1010                 goto out;
1011         }
1012
1013         switch (sap->sa_family) {
1014         case AF_INET:
1015                 err = kernel_bind(sock,
1016                                 (struct sockaddr *)&rpc_inaddr_loopback,
1017                                 sizeof(rpc_inaddr_loopback));
1018                 break;
1019         case AF_INET6:
1020                 err = kernel_bind(sock,
1021                                 (struct sockaddr *)&rpc_in6addr_loopback,
1022                                 sizeof(rpc_in6addr_loopback));
1023                 break;
1024         default:
1025                 err = -EAFNOSUPPORT;
1026                 goto out;
1027         }
1028         if (err < 0) {
1029                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1030                 goto out_release;
1031         }
1032
1033         err = kernel_connect(sock, sap, salen, 0);
1034         if (err < 0) {
1035                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1036                 goto out_release;
1037         }
1038
1039         err = kernel_getsockname(sock, buf, &buflen);
1040         if (err < 0) {
1041                 dprintk("RPC:       getsockname failed (%d)\n", err);
1042                 goto out_release;
1043         }
1044
1045         err = 0;
1046         if (buf->sa_family == AF_INET6) {
1047                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1048                 sin6->sin6_scope_id = 0;
1049         }
1050         dprintk("RPC:       %s succeeded\n", __func__);
1051
1052 out_release:
1053         sock_release(sock);
1054 out:
1055         return err;
1056 }
1057
1058 /*
1059  * Scraping a connected socket failed, so we don't have a useable
1060  * local address.  Fallback: generate an address that will prevent
1061  * the server from calling us back.
1062  *
1063  * Returns zero and fills in "buf" if successful; otherwise, a
1064  * negative errno is returned.
1065  */
1066 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1067 {
1068         switch (family) {
1069         case AF_INET:
1070                 if (buflen < sizeof(rpc_inaddr_loopback))
1071                         return -EINVAL;
1072                 memcpy(buf, &rpc_inaddr_loopback,
1073                                 sizeof(rpc_inaddr_loopback));
1074                 break;
1075         case AF_INET6:
1076                 if (buflen < sizeof(rpc_in6addr_loopback))
1077                         return -EINVAL;
1078                 memcpy(buf, &rpc_in6addr_loopback,
1079                                 sizeof(rpc_in6addr_loopback));
1080         default:
1081                 dprintk("RPC:       %s: address family not supported\n",
1082                         __func__);
1083                 return -EAFNOSUPPORT;
1084         }
1085         dprintk("RPC:       %s: succeeded\n", __func__);
1086         return 0;
1087 }
1088
1089 /**
1090  * rpc_localaddr - discover local endpoint address for an RPC client
1091  * @clnt: RPC client structure
1092  * @buf: target buffer
1093  * @buflen: size of target buffer, in bytes
1094  *
1095  * Returns zero and fills in "buf" and "buflen" if successful;
1096  * otherwise, a negative errno is returned.
1097  *
1098  * This works even if the underlying transport is not currently connected,
1099  * or if the upper layer never previously provided a source address.
1100  *
1101  * The result of this function call is transient: multiple calls in
1102  * succession may give different results, depending on how local
1103  * networking configuration changes over time.
1104  */
1105 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1106 {
1107         struct sockaddr_storage address;
1108         struct sockaddr *sap = (struct sockaddr *)&address;
1109         struct rpc_xprt *xprt;
1110         struct net *net;
1111         size_t salen;
1112         int err;
1113
1114         rcu_read_lock();
1115         xprt = rcu_dereference(clnt->cl_xprt);
1116         salen = xprt->addrlen;
1117         memcpy(sap, &xprt->addr, salen);
1118         net = get_net(xprt->xprt_net);
1119         rcu_read_unlock();
1120
1121         rpc_set_port(sap, 0);
1122         err = rpc_sockname(net, sap, salen, buf, buflen);
1123         put_net(net);
1124         if (err != 0)
1125                 /* Couldn't discover local address, return ANYADDR */
1126                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1127         return 0;
1128 }
1129 EXPORT_SYMBOL_GPL(rpc_localaddr);
1130
1131 void
1132 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1133 {
1134         struct rpc_xprt *xprt;
1135
1136         rcu_read_lock();
1137         xprt = rcu_dereference(clnt->cl_xprt);
1138         if (xprt->ops->set_buffer_size)
1139                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1140         rcu_read_unlock();
1141 }
1142 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1143
1144 /**
1145  * rpc_protocol - Get transport protocol number for an RPC client
1146  * @clnt: RPC client to query
1147  *
1148  */
1149 int rpc_protocol(struct rpc_clnt *clnt)
1150 {
1151         int protocol;
1152
1153         rcu_read_lock();
1154         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1155         rcu_read_unlock();
1156         return protocol;
1157 }
1158 EXPORT_SYMBOL_GPL(rpc_protocol);
1159
1160 /**
1161  * rpc_net_ns - Get the network namespace for this RPC client
1162  * @clnt: RPC client to query
1163  *
1164  */
1165 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1166 {
1167         struct net *ret;
1168
1169         rcu_read_lock();
1170         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1171         rcu_read_unlock();
1172         return ret;
1173 }
1174 EXPORT_SYMBOL_GPL(rpc_net_ns);
1175
1176 /**
1177  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1178  * @clnt: RPC client to query
1179  *
1180  * For stream transports, this is one RPC record fragment (see RFC
1181  * 1831), as we don't support multi-record requests yet.  For datagram
1182  * transports, this is the size of an IP packet minus the IP, UDP, and
1183  * RPC header sizes.
1184  */
1185 size_t rpc_max_payload(struct rpc_clnt *clnt)
1186 {
1187         size_t ret;
1188
1189         rcu_read_lock();
1190         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1191         rcu_read_unlock();
1192         return ret;
1193 }
1194 EXPORT_SYMBOL_GPL(rpc_max_payload);
1195
1196 /**
1197  * rpc_get_timeout - Get timeout for transport in units of HZ
1198  * @clnt: RPC client to query
1199  */
1200 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1201 {
1202         unsigned long ret;
1203
1204         rcu_read_lock();
1205         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1206         rcu_read_unlock();
1207         return ret;
1208 }
1209 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1210
1211 /**
1212  * rpc_force_rebind - force transport to check that remote port is unchanged
1213  * @clnt: client to rebind
1214  *
1215  */
1216 void rpc_force_rebind(struct rpc_clnt *clnt)
1217 {
1218         if (clnt->cl_autobind) {
1219                 rcu_read_lock();
1220                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1221                 rcu_read_unlock();
1222         }
1223 }
1224 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1225
1226 /*
1227  * Restart an (async) RPC call from the call_prepare state.
1228  * Usually called from within the exit handler.
1229  */
1230 int
1231 rpc_restart_call_prepare(struct rpc_task *task)
1232 {
1233         if (RPC_ASSASSINATED(task))
1234                 return 0;
1235         task->tk_action = call_start;
1236         if (task->tk_ops->rpc_call_prepare != NULL)
1237                 task->tk_action = rpc_prepare_task;
1238         return 1;
1239 }
1240 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1241
1242 /*
1243  * Restart an (async) RPC call. Usually called from within the
1244  * exit handler.
1245  */
1246 int
1247 rpc_restart_call(struct rpc_task *task)
1248 {
1249         if (RPC_ASSASSINATED(task))
1250                 return 0;
1251         task->tk_action = call_start;
1252         return 1;
1253 }
1254 EXPORT_SYMBOL_GPL(rpc_restart_call);
1255
1256 #ifdef RPC_DEBUG
1257 static const char *rpc_proc_name(const struct rpc_task *task)
1258 {
1259         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1260
1261         if (proc) {
1262                 if (proc->p_name)
1263                         return proc->p_name;
1264                 else
1265                         return "NULL";
1266         } else
1267                 return "no proc";
1268 }
1269 #endif
1270
1271 /*
1272  * 0.  Initial state
1273  *
1274  *     Other FSM states can be visited zero or more times, but
1275  *     this state is visited exactly once for each RPC.
1276  */
1277 static void
1278 call_start(struct rpc_task *task)
1279 {
1280         struct rpc_clnt *clnt = task->tk_client;
1281
1282         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1283                         clnt->cl_protname, clnt->cl_vers,
1284                         rpc_proc_name(task),
1285                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1286
1287         /* Increment call count */
1288         task->tk_msg.rpc_proc->p_count++;
1289         clnt->cl_stats->rpccnt++;
1290         task->tk_action = call_reserve;
1291 }
1292
1293 /*
1294  * 1.   Reserve an RPC call slot
1295  */
1296 static void
1297 call_reserve(struct rpc_task *task)
1298 {
1299         dprint_status(task);
1300
1301         task->tk_status  = 0;
1302         task->tk_action  = call_reserveresult;
1303         xprt_reserve(task);
1304 }
1305
1306 static void call_retry_reserve(struct rpc_task *task);
1307
1308 /*
1309  * 1b.  Grok the result of xprt_reserve()
1310  */
1311 static void
1312 call_reserveresult(struct rpc_task *task)
1313 {
1314         int status = task->tk_status;
1315
1316         dprint_status(task);
1317
1318         /*
1319          * After a call to xprt_reserve(), we must have either
1320          * a request slot or else an error status.
1321          */
1322         task->tk_status = 0;
1323         if (status >= 0) {
1324                 if (task->tk_rqstp) {
1325                         task->tk_action = call_refresh;
1326                         return;
1327                 }
1328
1329                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1330                                 __func__, status);
1331                 rpc_exit(task, -EIO);
1332                 return;
1333         }
1334
1335         /*
1336          * Even though there was an error, we may have acquired
1337          * a request slot somehow.  Make sure not to leak it.
1338          */
1339         if (task->tk_rqstp) {
1340                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1341                                 __func__, status);
1342                 xprt_release(task);
1343         }
1344
1345         switch (status) {
1346         case -ENOMEM:
1347                 rpc_delay(task, HZ >> 2);
1348         case -EAGAIN:   /* woken up; retry */
1349                 task->tk_action = call_retry_reserve;
1350                 return;
1351         case -EIO:      /* probably a shutdown */
1352                 break;
1353         default:
1354                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1355                                 __func__, status);
1356                 break;
1357         }
1358         rpc_exit(task, status);
1359 }
1360
1361 /*
1362  * 1c.  Retry reserving an RPC call slot
1363  */
1364 static void
1365 call_retry_reserve(struct rpc_task *task)
1366 {
1367         dprint_status(task);
1368
1369         task->tk_status  = 0;
1370         task->tk_action  = call_reserveresult;
1371         xprt_retry_reserve(task);
1372 }
1373
1374 /*
1375  * 2.   Bind and/or refresh the credentials
1376  */
1377 static void
1378 call_refresh(struct rpc_task *task)
1379 {
1380         dprint_status(task);
1381
1382         task->tk_action = call_refreshresult;
1383         task->tk_status = 0;
1384         task->tk_client->cl_stats->rpcauthrefresh++;
1385         rpcauth_refreshcred(task);
1386 }
1387
1388 /*
1389  * 2a.  Process the results of a credential refresh
1390  */
1391 static void
1392 call_refreshresult(struct rpc_task *task)
1393 {
1394         int status = task->tk_status;
1395
1396         dprint_status(task);
1397
1398         task->tk_status = 0;
1399         task->tk_action = call_refresh;
1400         switch (status) {
1401         case 0:
1402                 if (rpcauth_uptodatecred(task))
1403                         task->tk_action = call_allocate;
1404                 return;
1405         case -ETIMEDOUT:
1406                 rpc_delay(task, 3*HZ);
1407         case -EKEYEXPIRED:
1408         case -EAGAIN:
1409                 status = -EACCES;
1410                 if (!task->tk_cred_retry)
1411                         break;
1412                 task->tk_cred_retry--;
1413                 dprintk("RPC: %5u %s: retry refresh creds\n",
1414                                 task->tk_pid, __func__);
1415                 return;
1416         }
1417         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1418                                 task->tk_pid, __func__, status);
1419         rpc_exit(task, status);
1420 }
1421
1422 /*
1423  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1424  *      (Note: buffer memory is freed in xprt_release).
1425  */
1426 static void
1427 call_allocate(struct rpc_task *task)
1428 {
1429         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1430         struct rpc_rqst *req = task->tk_rqstp;
1431         struct rpc_xprt *xprt = req->rq_xprt;
1432         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1433
1434         dprint_status(task);
1435
1436         task->tk_status = 0;
1437         task->tk_action = call_bind;
1438
1439         if (req->rq_buffer)
1440                 return;
1441
1442         if (proc->p_proc != 0) {
1443                 BUG_ON(proc->p_arglen == 0);
1444                 if (proc->p_decode != NULL)
1445                         BUG_ON(proc->p_replen == 0);
1446         }
1447
1448         /*
1449          * Calculate the size (in quads) of the RPC call
1450          * and reply headers, and convert both values
1451          * to byte sizes.
1452          */
1453         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1454         req->rq_callsize <<= 2;
1455         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1456         req->rq_rcvsize <<= 2;
1457
1458         req->rq_buffer = xprt->ops->buf_alloc(task,
1459                                         req->rq_callsize + req->rq_rcvsize);
1460         if (req->rq_buffer != NULL)
1461                 return;
1462
1463         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1464
1465         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1466                 task->tk_action = call_allocate;
1467                 rpc_delay(task, HZ>>4);
1468                 return;
1469         }
1470
1471         rpc_exit(task, -ERESTARTSYS);
1472 }
1473
1474 static inline int
1475 rpc_task_need_encode(struct rpc_task *task)
1476 {
1477         return task->tk_rqstp->rq_snd_buf.len == 0;
1478 }
1479
1480 static inline void
1481 rpc_task_force_reencode(struct rpc_task *task)
1482 {
1483         task->tk_rqstp->rq_snd_buf.len = 0;
1484         task->tk_rqstp->rq_bytes_sent = 0;
1485 }
1486
1487 static inline void
1488 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1489 {
1490         buf->head[0].iov_base = start;
1491         buf->head[0].iov_len = len;
1492         buf->tail[0].iov_len = 0;
1493         buf->page_len = 0;
1494         buf->flags = 0;
1495         buf->len = 0;
1496         buf->buflen = len;
1497 }
1498
1499 /*
1500  * 3.   Encode arguments of an RPC call
1501  */
1502 static void
1503 rpc_xdr_encode(struct rpc_task *task)
1504 {
1505         struct rpc_rqst *req = task->tk_rqstp;
1506         kxdreproc_t     encode;
1507         __be32          *p;
1508
1509         dprint_status(task);
1510
1511         rpc_xdr_buf_init(&req->rq_snd_buf,
1512                          req->rq_buffer,
1513                          req->rq_callsize);
1514         rpc_xdr_buf_init(&req->rq_rcv_buf,
1515                          (char *)req->rq_buffer + req->rq_callsize,
1516                          req->rq_rcvsize);
1517
1518         p = rpc_encode_header(task);
1519         if (p == NULL) {
1520                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1521                 rpc_exit(task, -EIO);
1522                 return;
1523         }
1524
1525         encode = task->tk_msg.rpc_proc->p_encode;
1526         if (encode == NULL)
1527                 return;
1528
1529         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1530                         task->tk_msg.rpc_argp);
1531 }
1532
1533 /*
1534  * 4.   Get the server port number if not yet set
1535  */
1536 static void
1537 call_bind(struct rpc_task *task)
1538 {
1539         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1540
1541         dprint_status(task);
1542
1543         task->tk_action = call_connect;
1544         if (!xprt_bound(xprt)) {
1545                 task->tk_action = call_bind_status;
1546                 task->tk_timeout = xprt->bind_timeout;
1547                 xprt->ops->rpcbind(task);
1548         }
1549 }
1550
1551 /*
1552  * 4a.  Sort out bind result
1553  */
1554 static void
1555 call_bind_status(struct rpc_task *task)
1556 {
1557         int status = -EIO;
1558
1559         if (task->tk_status >= 0) {
1560                 dprint_status(task);
1561                 task->tk_status = 0;
1562                 task->tk_action = call_connect;
1563                 return;
1564         }
1565
1566         trace_rpc_bind_status(task);
1567         switch (task->tk_status) {
1568         case -ENOMEM:
1569                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1570                 rpc_delay(task, HZ >> 2);
1571                 goto retry_timeout;
1572         case -EACCES:
1573                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1574                                 "unavailable\n", task->tk_pid);
1575                 /* fail immediately if this is an RPC ping */
1576                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1577                         status = -EOPNOTSUPP;
1578                         break;
1579                 }
1580                 if (task->tk_rebind_retry == 0)
1581                         break;
1582                 task->tk_rebind_retry--;
1583                 rpc_delay(task, 3*HZ);
1584                 goto retry_timeout;
1585         case -ETIMEDOUT:
1586                 dprintk("RPC: %5u rpcbind request timed out\n",
1587                                 task->tk_pid);
1588                 goto retry_timeout;
1589         case -EPFNOSUPPORT:
1590                 /* server doesn't support any rpcbind version we know of */
1591                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1592                                 task->tk_pid);
1593                 break;
1594         case -EPROTONOSUPPORT:
1595                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1596                                 task->tk_pid);
1597                 task->tk_status = 0;
1598                 task->tk_action = call_bind;
1599                 return;
1600         case -ECONNREFUSED:             /* connection problems */
1601         case -ECONNRESET:
1602         case -ENOTCONN:
1603         case -EHOSTDOWN:
1604         case -EHOSTUNREACH:
1605         case -ENETUNREACH:
1606         case -EPIPE:
1607                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1608                                 task->tk_pid, task->tk_status);
1609                 if (!RPC_IS_SOFTCONN(task)) {
1610                         rpc_delay(task, 5*HZ);
1611                         goto retry_timeout;
1612                 }
1613                 status = task->tk_status;
1614                 break;
1615         default:
1616                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1617                                 task->tk_pid, -task->tk_status);
1618         }
1619
1620         rpc_exit(task, status);
1621         return;
1622
1623 retry_timeout:
1624         task->tk_action = call_timeout;
1625 }
1626
1627 /*
1628  * 4b.  Connect to the RPC server
1629  */
1630 static void
1631 call_connect(struct rpc_task *task)
1632 {
1633         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1634
1635         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1636                         task->tk_pid, xprt,
1637                         (xprt_connected(xprt) ? "is" : "is not"));
1638
1639         task->tk_action = call_transmit;
1640         if (!xprt_connected(xprt)) {
1641                 task->tk_action = call_connect_status;
1642                 if (task->tk_status < 0)
1643                         return;
1644                 xprt_connect(task);
1645         }
1646 }
1647
1648 /*
1649  * 4c.  Sort out connect result
1650  */
1651 static void
1652 call_connect_status(struct rpc_task *task)
1653 {
1654         struct rpc_clnt *clnt = task->tk_client;
1655         int status = task->tk_status;
1656
1657         dprint_status(task);
1658
1659         trace_rpc_connect_status(task, status);
1660         switch (status) {
1661                 /* if soft mounted, test if we've timed out */
1662         case -ETIMEDOUT:
1663                 task->tk_action = call_timeout;
1664                 return;
1665         case -ECONNREFUSED:
1666         case -ECONNRESET:
1667         case -ENETUNREACH:
1668                 if (RPC_IS_SOFTCONN(task))
1669                         break;
1670                 /* retry with existing socket, after a delay */
1671         case 0:
1672         case -EAGAIN:
1673                 task->tk_status = 0;
1674                 clnt->cl_stats->netreconn++;
1675                 task->tk_action = call_transmit;
1676                 return;
1677         }
1678         rpc_exit(task, status);
1679 }
1680
1681 /*
1682  * 5.   Transmit the RPC request, and wait for reply
1683  */
1684 static void
1685 call_transmit(struct rpc_task *task)
1686 {
1687         dprint_status(task);
1688
1689         task->tk_action = call_status;
1690         if (task->tk_status < 0)
1691                 return;
1692         task->tk_status = xprt_prepare_transmit(task);
1693         if (task->tk_status != 0)
1694                 return;
1695         task->tk_action = call_transmit_status;
1696         /* Encode here so that rpcsec_gss can use correct sequence number. */
1697         if (rpc_task_need_encode(task)) {
1698                 rpc_xdr_encode(task);
1699                 /* Did the encode result in an error condition? */
1700                 if (task->tk_status != 0) {
1701                         /* Was the error nonfatal? */
1702                         if (task->tk_status == -EAGAIN)
1703                                 rpc_delay(task, HZ >> 4);
1704                         else
1705                                 rpc_exit(task, task->tk_status);
1706                         return;
1707                 }
1708         }
1709         xprt_transmit(task);
1710         if (task->tk_status < 0)
1711                 return;
1712         /*
1713          * On success, ensure that we call xprt_end_transmit() before sleeping
1714          * in order to allow access to the socket to other RPC requests.
1715          */
1716         call_transmit_status(task);
1717         if (rpc_reply_expected(task))
1718                 return;
1719         task->tk_action = rpc_exit_task;
1720         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1721 }
1722
1723 /*
1724  * 5a.  Handle cleanup after a transmission
1725  */
1726 static void
1727 call_transmit_status(struct rpc_task *task)
1728 {
1729         task->tk_action = call_status;
1730
1731         /*
1732          * Common case: success.  Force the compiler to put this
1733          * test first.
1734          */
1735         if (task->tk_status == 0) {
1736                 xprt_end_transmit(task);
1737                 rpc_task_force_reencode(task);
1738                 return;
1739         }
1740
1741         switch (task->tk_status) {
1742         case -EAGAIN:
1743                 break;
1744         default:
1745                 dprint_status(task);
1746                 xprt_end_transmit(task);
1747                 rpc_task_force_reencode(task);
1748                 break;
1749                 /*
1750                  * Special cases: if we've been waiting on the
1751                  * socket's write_space() callback, or if the
1752                  * socket just returned a connection error,
1753                  * then hold onto the transport lock.
1754                  */
1755         case -ECONNREFUSED:
1756         case -EHOSTDOWN:
1757         case -EHOSTUNREACH:
1758         case -ENETUNREACH:
1759                 if (RPC_IS_SOFTCONN(task)) {
1760                         xprt_end_transmit(task);
1761                         rpc_exit(task, task->tk_status);
1762                         break;
1763                 }
1764         case -ECONNRESET:
1765         case -ENOTCONN:
1766         case -EPIPE:
1767                 rpc_task_force_reencode(task);
1768         }
1769 }
1770
1771 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1772 /*
1773  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1774  * addition, disconnect on connectivity errors.
1775  */
1776 static void
1777 call_bc_transmit(struct rpc_task *task)
1778 {
1779         struct rpc_rqst *req = task->tk_rqstp;
1780
1781         task->tk_status = xprt_prepare_transmit(task);
1782         if (task->tk_status == -EAGAIN) {
1783                 /*
1784                  * Could not reserve the transport. Try again after the
1785                  * transport is released.
1786                  */
1787                 task->tk_status = 0;
1788                 task->tk_action = call_bc_transmit;
1789                 return;
1790         }
1791
1792         task->tk_action = rpc_exit_task;
1793         if (task->tk_status < 0) {
1794                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1795                         "error: %d\n", task->tk_status);
1796                 return;
1797         }
1798
1799         xprt_transmit(task);
1800         xprt_end_transmit(task);
1801         dprint_status(task);
1802         switch (task->tk_status) {
1803         case 0:
1804                 /* Success */
1805                 break;
1806         case -EHOSTDOWN:
1807         case -EHOSTUNREACH:
1808         case -ENETUNREACH:
1809         case -ETIMEDOUT:
1810                 /*
1811                  * Problem reaching the server.  Disconnect and let the
1812                  * forechannel reestablish the connection.  The server will
1813                  * have to retransmit the backchannel request and we'll
1814                  * reprocess it.  Since these ops are idempotent, there's no
1815                  * need to cache our reply at this time.
1816                  */
1817                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1818                         "error: %d\n", task->tk_status);
1819                 xprt_conditional_disconnect(req->rq_xprt,
1820                         req->rq_connect_cookie);
1821                 break;
1822         default:
1823                 /*
1824                  * We were unable to reply and will have to drop the
1825                  * request.  The server should reconnect and retransmit.
1826                  */
1827                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1828                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1829                         "error: %d\n", task->tk_status);
1830                 break;
1831         }
1832         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1833 }
1834 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1835
1836 /*
1837  * 6.   Sort out the RPC call status
1838  */
1839 static void
1840 call_status(struct rpc_task *task)
1841 {
1842         struct rpc_clnt *clnt = task->tk_client;
1843         struct rpc_rqst *req = task->tk_rqstp;
1844         int             status;
1845
1846         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1847                 task->tk_status = req->rq_reply_bytes_recvd;
1848
1849         dprint_status(task);
1850
1851         status = task->tk_status;
1852         if (status >= 0) {
1853                 task->tk_action = call_decode;
1854                 return;
1855         }
1856
1857         trace_rpc_call_status(task);
1858         task->tk_status = 0;
1859         switch(status) {
1860         case -EHOSTDOWN:
1861         case -EHOSTUNREACH:
1862         case -ENETUNREACH:
1863                 /*
1864                  * Delay any retries for 3 seconds, then handle as if it
1865                  * were a timeout.
1866                  */
1867                 rpc_delay(task, 3*HZ);
1868         case -ETIMEDOUT:
1869                 task->tk_action = call_timeout;
1870                 if (task->tk_client->cl_discrtry)
1871                         xprt_conditional_disconnect(req->rq_xprt,
1872                                         req->rq_connect_cookie);
1873                 break;
1874         case -ECONNRESET:
1875         case -ECONNREFUSED:
1876                 rpc_force_rebind(clnt);
1877                 rpc_delay(task, 3*HZ);
1878         case -EPIPE:
1879         case -ENOTCONN:
1880                 task->tk_action = call_bind;
1881                 break;
1882         case -EAGAIN:
1883                 task->tk_action = call_transmit;
1884                 break;
1885         case -EIO:
1886                 /* shutdown or soft timeout */
1887                 rpc_exit(task, status);
1888                 break;
1889         default:
1890                 if (clnt->cl_chatty)
1891                         printk("%s: RPC call returned error %d\n",
1892                                clnt->cl_protname, -status);
1893                 rpc_exit(task, status);
1894         }
1895 }
1896
1897 /*
1898  * 6a.  Handle RPC timeout
1899  *      We do not release the request slot, so we keep using the
1900  *      same XID for all retransmits.
1901  */
1902 static void
1903 call_timeout(struct rpc_task *task)
1904 {
1905         struct rpc_clnt *clnt = task->tk_client;
1906
1907         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1908                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1909                 goto retry;
1910         }
1911
1912         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1913         task->tk_timeouts++;
1914
1915         if (RPC_IS_SOFTCONN(task)) {
1916                 rpc_exit(task, -ETIMEDOUT);
1917                 return;
1918         }
1919         if (RPC_IS_SOFT(task)) {
1920                 if (clnt->cl_chatty) {
1921                         rcu_read_lock();
1922                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1923                                 clnt->cl_protname,
1924                                 rcu_dereference(clnt->cl_xprt)->servername);
1925                         rcu_read_unlock();
1926                 }
1927                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1928                         rpc_exit(task, -ETIMEDOUT);
1929                 else
1930                         rpc_exit(task, -EIO);
1931                 return;
1932         }
1933
1934         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1935                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1936                 if (clnt->cl_chatty) {
1937                         rcu_read_lock();
1938                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1939                         clnt->cl_protname,
1940                         rcu_dereference(clnt->cl_xprt)->servername);
1941                         rcu_read_unlock();
1942                 }
1943         }
1944         rpc_force_rebind(clnt);
1945         /*
1946          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1947          * event? RFC2203 requires the server to drop all such requests.
1948          */
1949         rpcauth_invalcred(task);
1950
1951 retry:
1952         clnt->cl_stats->rpcretrans++;
1953         task->tk_action = call_bind;
1954         task->tk_status = 0;
1955 }
1956
1957 /*
1958  * 7.   Decode the RPC reply
1959  */
1960 static void
1961 call_decode(struct rpc_task *task)
1962 {
1963         struct rpc_clnt *clnt = task->tk_client;
1964         struct rpc_rqst *req = task->tk_rqstp;
1965         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1966         __be32          *p;
1967
1968         dprint_status(task);
1969
1970         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1971                 if (clnt->cl_chatty) {
1972                         rcu_read_lock();
1973                         printk(KERN_NOTICE "%s: server %s OK\n",
1974                                 clnt->cl_protname,
1975                                 rcu_dereference(clnt->cl_xprt)->servername);
1976                         rcu_read_unlock();
1977                 }
1978                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1979         }
1980
1981         /*
1982          * Ensure that we see all writes made by xprt_complete_rqst()
1983          * before it changed req->rq_reply_bytes_recvd.
1984          */
1985         smp_rmb();
1986         req->rq_rcv_buf.len = req->rq_private_buf.len;
1987
1988         /* Check that the softirq receive buffer is valid */
1989         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1990                                 sizeof(req->rq_rcv_buf)) != 0);
1991
1992         if (req->rq_rcv_buf.len < 12) {
1993                 if (!RPC_IS_SOFT(task)) {
1994                         task->tk_action = call_bind;
1995                         clnt->cl_stats->rpcretrans++;
1996                         goto out_retry;
1997                 }
1998                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1999                                 clnt->cl_protname, task->tk_status);
2000                 task->tk_action = call_timeout;
2001                 goto out_retry;
2002         }
2003
2004         p = rpc_verify_header(task);
2005         if (IS_ERR(p)) {
2006                 if (p == ERR_PTR(-EAGAIN))
2007                         goto out_retry;
2008                 return;
2009         }
2010
2011         task->tk_action = rpc_exit_task;
2012
2013         if (decode) {
2014                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2015                                                       task->tk_msg.rpc_resp);
2016         }
2017         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2018                         task->tk_status);
2019         return;
2020 out_retry:
2021         task->tk_status = 0;
2022         /* Note: rpc_verify_header() may have freed the RPC slot */
2023         if (task->tk_rqstp == req) {
2024                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2025                 if (task->tk_client->cl_discrtry)
2026                         xprt_conditional_disconnect(req->rq_xprt,
2027                                         req->rq_connect_cookie);
2028         }
2029 }
2030
2031 static __be32 *
2032 rpc_encode_header(struct rpc_task *task)
2033 {
2034         struct rpc_clnt *clnt = task->tk_client;
2035         struct rpc_rqst *req = task->tk_rqstp;
2036         __be32          *p = req->rq_svec[0].iov_base;
2037
2038         /* FIXME: check buffer size? */
2039
2040         p = xprt_skip_transport_header(req->rq_xprt, p);
2041         *p++ = req->rq_xid;             /* XID */
2042         *p++ = htonl(RPC_CALL);         /* CALL */
2043         *p++ = htonl(RPC_VERSION);      /* RPC version */
2044         *p++ = htonl(clnt->cl_prog);    /* program number */
2045         *p++ = htonl(clnt->cl_vers);    /* program version */
2046         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2047         p = rpcauth_marshcred(task, p);
2048         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2049         return p;
2050 }
2051
2052 static __be32 *
2053 rpc_verify_header(struct rpc_task *task)
2054 {
2055         struct rpc_clnt *clnt = task->tk_client;
2056         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2057         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2058         __be32  *p = iov->iov_base;
2059         u32 n;
2060         int error = -EACCES;
2061
2062         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2063                 /* RFC-1014 says that the representation of XDR data must be a
2064                  * multiple of four bytes
2065                  * - if it isn't pointer subtraction in the NFS client may give
2066                  *   undefined results
2067                  */
2068                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2069                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2070                        task->tk_rqstp->rq_rcv_buf.len);
2071                 goto out_eio;
2072         }
2073         if ((len -= 3) < 0)
2074                 goto out_overflow;
2075
2076         p += 1; /* skip XID */
2077         if ((n = ntohl(*p++)) != RPC_REPLY) {
2078                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2079                         task->tk_pid, __func__, n);
2080                 goto out_garbage;
2081         }
2082
2083         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2084                 if (--len < 0)
2085                         goto out_overflow;
2086                 switch ((n = ntohl(*p++))) {
2087                 case RPC_AUTH_ERROR:
2088                         break;
2089                 case RPC_MISMATCH:
2090                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2091                                 task->tk_pid, __func__);
2092                         error = -EPROTONOSUPPORT;
2093                         goto out_err;
2094                 default:
2095                         dprintk("RPC: %5u %s: RPC call rejected, "
2096                                 "unknown error: %x\n",
2097                                 task->tk_pid, __func__, n);
2098                         goto out_eio;
2099                 }
2100                 if (--len < 0)
2101                         goto out_overflow;
2102                 switch ((n = ntohl(*p++))) {
2103                 case RPC_AUTH_REJECTEDCRED:
2104                 case RPC_AUTH_REJECTEDVERF:
2105                 case RPCSEC_GSS_CREDPROBLEM:
2106                 case RPCSEC_GSS_CTXPROBLEM:
2107                         if (!task->tk_cred_retry)
2108                                 break;
2109                         task->tk_cred_retry--;
2110                         dprintk("RPC: %5u %s: retry stale creds\n",
2111                                         task->tk_pid, __func__);
2112                         rpcauth_invalcred(task);
2113                         /* Ensure we obtain a new XID! */
2114                         xprt_release(task);
2115                         task->tk_action = call_reserve;
2116                         goto out_retry;
2117                 case RPC_AUTH_BADCRED:
2118                 case RPC_AUTH_BADVERF:
2119                         /* possibly garbled cred/verf? */
2120                         if (!task->tk_garb_retry)
2121                                 break;
2122                         task->tk_garb_retry--;
2123                         dprintk("RPC: %5u %s: retry garbled creds\n",
2124                                         task->tk_pid, __func__);
2125                         task->tk_action = call_bind;
2126                         goto out_retry;
2127                 case RPC_AUTH_TOOWEAK:
2128                         rcu_read_lock();
2129                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2130                                "authentication.\n",
2131                                rcu_dereference(clnt->cl_xprt)->servername);
2132                         rcu_read_unlock();
2133                         break;
2134                 default:
2135                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2136                                         task->tk_pid, __func__, n);
2137                         error = -EIO;
2138                 }
2139                 dprintk("RPC: %5u %s: call rejected %d\n",
2140                                 task->tk_pid, __func__, n);
2141                 goto out_err;
2142         }
2143         if (!(p = rpcauth_checkverf(task, p))) {
2144                 dprintk("RPC: %5u %s: auth check failed\n",
2145                                 task->tk_pid, __func__);
2146                 goto out_garbage;               /* bad verifier, retry */
2147         }
2148         len = p - (__be32 *)iov->iov_base - 1;
2149         if (len < 0)
2150                 goto out_overflow;
2151         switch ((n = ntohl(*p++))) {
2152         case RPC_SUCCESS:
2153                 return p;
2154         case RPC_PROG_UNAVAIL:
2155                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2156                                 "by server %s\n", task->tk_pid, __func__,
2157                                 (unsigned int)clnt->cl_prog,
2158                                 rcu_dereference(clnt->cl_xprt)->servername);
2159                 error = -EPFNOSUPPORT;
2160                 goto out_err;
2161         case RPC_PROG_MISMATCH:
2162                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2163                                 "by server %s\n", task->tk_pid, __func__,
2164                                 (unsigned int)clnt->cl_prog,
2165                                 (unsigned int)clnt->cl_vers,
2166                                 rcu_dereference(clnt->cl_xprt)->servername);
2167                 error = -EPROTONOSUPPORT;
2168                 goto out_err;
2169         case RPC_PROC_UNAVAIL:
2170                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2171                                 "version %u on server %s\n",
2172                                 task->tk_pid, __func__,
2173                                 rpc_proc_name(task),
2174                                 clnt->cl_prog, clnt->cl_vers,
2175                                 rcu_dereference(clnt->cl_xprt)->servername);
2176                 error = -EOPNOTSUPP;
2177                 goto out_err;
2178         case RPC_GARBAGE_ARGS:
2179                 dprintk("RPC: %5u %s: server saw garbage\n",
2180                                 task->tk_pid, __func__);
2181                 break;                  /* retry */
2182         default:
2183                 dprintk("RPC: %5u %s: server accept status: %x\n",
2184                                 task->tk_pid, __func__, n);
2185                 /* Also retry */
2186         }
2187
2188 out_garbage:
2189         clnt->cl_stats->rpcgarbage++;
2190         if (task->tk_garb_retry) {
2191                 task->tk_garb_retry--;
2192                 dprintk("RPC: %5u %s: retrying\n",
2193                                 task->tk_pid, __func__);
2194                 task->tk_action = call_bind;
2195 out_retry:
2196                 return ERR_PTR(-EAGAIN);
2197         }
2198 out_eio:
2199         error = -EIO;
2200 out_err:
2201         rpc_exit(task, error);
2202         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2203                         __func__, error);
2204         return ERR_PTR(error);
2205 out_overflow:
2206         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2207                         __func__);
2208         goto out_garbage;
2209 }
2210
2211 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2212 {
2213 }
2214
2215 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2216 {
2217         return 0;
2218 }
2219
2220 static struct rpc_procinfo rpcproc_null = {
2221         .p_encode = rpcproc_encode_null,
2222         .p_decode = rpcproc_decode_null,
2223 };
2224
2225 static int rpc_ping(struct rpc_clnt *clnt)
2226 {
2227         struct rpc_message msg = {
2228                 .rpc_proc = &rpcproc_null,
2229         };
2230         int err;
2231         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2232         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2233         put_rpccred(msg.rpc_cred);
2234         return err;
2235 }
2236
2237 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2238 {
2239         struct rpc_message msg = {
2240                 .rpc_proc = &rpcproc_null,
2241                 .rpc_cred = cred,
2242         };
2243         struct rpc_task_setup task_setup_data = {
2244                 .rpc_client = clnt,
2245                 .rpc_message = &msg,
2246                 .callback_ops = &rpc_default_ops,
2247                 .flags = flags,
2248         };
2249         return rpc_run_task(&task_setup_data);
2250 }
2251 EXPORT_SYMBOL_GPL(rpc_call_null);
2252
2253 #ifdef RPC_DEBUG
2254 static void rpc_show_header(void)
2255 {
2256         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2257                 "-timeout ---ops--\n");
2258 }
2259
2260 static void rpc_show_task(const struct rpc_clnt *clnt,
2261                           const struct rpc_task *task)
2262 {
2263         const char *rpc_waitq = "none";
2264
2265         if (RPC_IS_QUEUED(task))
2266                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2267
2268         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2269                 task->tk_pid, task->tk_flags, task->tk_status,
2270                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2271                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2272                 task->tk_action, rpc_waitq);
2273 }
2274
2275 void rpc_show_tasks(struct net *net)
2276 {
2277         struct rpc_clnt *clnt;
2278         struct rpc_task *task;
2279         int header = 0;
2280         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2281
2282         spin_lock(&sn->rpc_client_lock);
2283         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2284                 spin_lock(&clnt->cl_lock);
2285                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2286                         if (!header) {
2287                                 rpc_show_header();
2288                                 header++;
2289                         }
2290                         rpc_show_task(clnt, task);
2291                 }
2292                 spin_unlock(&clnt->cl_lock);
2293         }
2294         spin_unlock(&sn->rpc_client_lock);
2295 }
2296 #endif