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 dentry *dir, *dentry;
 132
 133         dir = rpc_d_lookup_sb(sb, dir_name);
 134         if (dir == NULL) {
 135                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 136                 return dir;
 137         }
 138         for (;;) {
 139                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 140                 name[sizeof(name) - 1] = '\0';
 141                 dentry = rpc_create_client_dir(dir, name, clnt);
 142                 if (!IS_ERR(dentry))
 143                         break;
 144                 if (dentry == ERR_PTR(-EEXIST))
 145                         continue;
 146                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 147                                 " %s/%s, error %ld\n",
 148                                 dir_name, name, PTR_ERR(dentry));
 149                 break;
 150         }
 151         dput(dir);
 152         return dentry;
 153 }
 154
 155 static int
 156 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name,
 157                   struct super_block *pipefs_sb)
 158 {
 159         struct dentry *dentry;
 160
 161         clnt->cl_dentry = NULL;
 162         if (dir_name == NULL)
 163                 return 0;
 164         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 165         if (IS_ERR(dentry))
 166                 return PTR_ERR(dentry);
 167         clnt->cl_dentry = dentry;
 168         return 0;
 169 }
 170
 171 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 172 {
 173         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 174             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 175                 return 1;
 176         if ((event == RPC_PIPEFS_MOUNT) && atomic_read(&clnt->cl_count) == 0)
 177                 return 1;
 178         return 0;
 179 }
 180
 181 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 182                                    struct super_block *sb)
 183 {
 184         struct dentry *dentry;
 185         int err = 0;
 186
 187         switch (event) {
 188         case RPC_PIPEFS_MOUNT:
 189                 dentry = rpc_setup_pipedir_sb(sb, clnt,
 190                                               clnt->cl_program->pipe_dir_name);
 191                 if (!dentry)
 192                         return -ENOENT;
 193                 if (IS_ERR(dentry))
 194                         return PTR_ERR(dentry);
 195                 clnt->cl_dentry = dentry;
 196                 if (clnt->cl_auth->au_ops->pipes_create) {
 197                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 198                         if (err)
 199                                 __rpc_clnt_remove_pipedir(clnt);
 200                 }
 201                 break;
 202         case RPC_PIPEFS_UMOUNT:
 203                 __rpc_clnt_remove_pipedir(clnt);
 204                 break;
 205         default:
 206                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 207                 return -ENOTSUPP;
 208         }
 209         return err;
 210 }
 211
 212 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 213                                 struct super_block *sb)
 214 {
 215         int error = 0;
 216
 217         for (;; clnt = clnt->cl_parent) {
 218                 if (!rpc_clnt_skip_event(clnt, event))
 219                         error = __rpc_clnt_handle_event(clnt, event, sb);
 220                 if (error || clnt == clnt->cl_parent)
 221                         break;
 222         }
 223         return error;
 224 }
 225
 226 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 227 {
 228         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 229         struct rpc_clnt *clnt;
 230
 231         spin_lock(&sn->rpc_client_lock);
 232         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 233                 if (clnt->cl_program->pipe_dir_name == NULL)
 234                         continue;
 235                 if (rpc_clnt_skip_event(clnt, event))
 236                         continue;
 237                 spin_unlock(&sn->rpc_client_lock);
 238                 return clnt;
 239         }
 240         spin_unlock(&sn->rpc_client_lock);
 241         return NULL;
 242 }
 243
 244 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 245                             void *ptr)
 246 {
 247         struct super_block *sb = ptr;
 248         struct rpc_clnt *clnt;
 249         int error = 0;
 250
 251         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 252                 error = __rpc_pipefs_event(clnt, event, sb);
 253                 if (error)
 254                         break;
 255         }
 256         return error;
 257 }
 258
 259 static struct notifier_block rpc_clients_block = {
 260         .notifier_call  = rpc_pipefs_event,
 261         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 262 };
 263
 264 int rpc_clients_notifier_register(void)
 265 {
 266         return rpc_pipefs_notifier_register(&rpc_clients_block);
 267 }
 268
 269 void rpc_clients_notifier_unregister(void)
 270 {
 271         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 272 }
 273
 274 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 275 {
 276         clnt->cl_nodelen = strlen(nodename);
 277         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 278                 clnt->cl_nodelen = UNX_MAXNODENAME;
 279         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 280 }
 281
 282 static int rpc_client_register(const struct rpc_create_args *args,
 283                                struct rpc_clnt *clnt)
 284 {
 285         const struct rpc_program *program = args->program;
 286         struct rpc_auth *auth;
 287         struct net *net = rpc_net_ns(clnt);
 288         struct super_block *pipefs_sb;
 289         int err;
 290
 291         pipefs_sb = rpc_get_sb_net(net);
 292         if (pipefs_sb) {
 293                 err = rpc_setup_pipedir(clnt, program->pipe_dir_name, pipefs_sb);
 294                 if (err)
 295                         goto out;
 296         }
 297
 298         rpc_register_client(clnt);
 299         if (pipefs_sb)
 300                 rpc_put_sb_net(net);
 301
 302         auth = rpcauth_create(args->authflavor, clnt);
 303         if (IS_ERR(auth)) {
 304                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 305                                 args->authflavor);
 306                 err = PTR_ERR(auth);
 307                 goto err_auth;
 308         }
 309         return 0;
 310 err_auth:
 311         pipefs_sb = rpc_get_sb_net(net);
 312         __rpc_clnt_remove_pipedir(clnt);
 313 out:
 314         if (pipefs_sb)
 315                 rpc_put_sb_net(net);
 316         return err;
 317 }
 318
 319 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 320 {
 321         const struct rpc_program *program = args->program;
 322         const struct rpc_version *version;
 323         struct rpc_clnt         *clnt = NULL;
 324         int err;
 325
 326         /* sanity check the name before trying to print it */
 327         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 328                         program->name, args->servername, xprt);
 329
 330         err = rpciod_up();
 331         if (err)
 332                 goto out_no_rpciod;
 333
 334         err = -EINVAL;
 335         if (args->version >= program->nrvers)
 336                 goto out_err;
 337         version = program->version[args->version];
 338         if (version == NULL)
 339                 goto out_err;
 340
 341         err = -ENOMEM;
 342         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 343         if (!clnt)
 344                 goto out_err;
 345         clnt->cl_parent = clnt;
 346
 347         rcu_assign_pointer(clnt->cl_xprt, xprt);
 348         clnt->cl_procinfo = version->procs;
 349         clnt->cl_maxproc  = version->nrprocs;
 350         clnt->cl_protname = program->name;
 351         clnt->cl_prog     = args->prognumber ? : program->number;
 352         clnt->cl_vers     = version->number;
 353         clnt->cl_stats    = program->stats;
 354         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 355         err = -ENOMEM;
 356         if (clnt->cl_metrics == NULL)
 357                 goto out_no_stats;
 358         clnt->cl_program  = program;
 359         INIT_LIST_HEAD(&clnt->cl_tasks);
 360         spin_lock_init(&clnt->cl_lock);
 361
 362         if (!xprt_bound(xprt))
 363                 clnt->cl_autobind = 1;
 364
 365         clnt->cl_timeout = xprt->timeout;
 366         if (args->timeout != NULL) {
 367                 memcpy(&clnt->cl_timeout_default, args->timeout,
 368                                 sizeof(clnt->cl_timeout_default));
 369                 clnt->cl_timeout = &clnt->cl_timeout_default;
 370         }
 371
 372         clnt->cl_rtt = &clnt->cl_rtt_default;
 373         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 374         clnt->cl_principal = NULL;
 375         if (args->client_name) {
 376                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 377                 if (!clnt->cl_principal)
 378                         goto out_no_principal;
 379         }
 380
 381         atomic_set(&clnt->cl_count, 1);
 382
 383         /* save the nodename */
 384         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 385
 386         err = rpc_client_register(args, clnt);
 387         if (err)
 388                 goto out_no_path;
 389         return clnt;
 390
 391 out_no_path:
 392         kfree(clnt->cl_principal);
 393 out_no_principal:
 394         rpc_free_iostats(clnt->cl_metrics);
 395 out_no_stats:
 396         kfree(clnt);
 397 out_err:
 398         rpciod_down();
 399 out_no_rpciod:
 400         xprt_put(xprt);
 401         return ERR_PTR(err);
 402 }
 403
 404 /**
 405  * rpc_create - create an RPC client and transport with one call
 406  * @args: rpc_clnt create argument structure
 407  *
 408  * Creates and initializes an RPC transport and an RPC client.
 409  *
 410  * It can ping the server in order to determine if it is up, and to see if
 411  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 412  * this behavior so asynchronous tasks can also use rpc_create.
 413  */
 414 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 415 {
 416         struct rpc_xprt *xprt;
 417         struct rpc_clnt *clnt;
 418         struct xprt_create xprtargs = {
 419                 .net = args->net,
 420                 .ident = args->protocol,
 421                 .srcaddr = args->saddress,
 422                 .dstaddr = args->address,
 423                 .addrlen = args->addrsize,
 424                 .servername = args->servername,
 425                 .bc_xprt = args->bc_xprt,
 426         };
 427         char servername[48];
 428
 429         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 430                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 431         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 432                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 433         /*
 434          * If the caller chooses not to specify a hostname, whip
 435          * up a string representation of the passed-in address.
 436          */
 437         if (xprtargs.servername == NULL) {
 438                 struct sockaddr_un *sun =
 439                                 (struct sockaddr_un *)args->address;
 440                 struct sockaddr_in *sin =
 441                                 (struct sockaddr_in *)args->address;
 442                 struct sockaddr_in6 *sin6 =
 443                                 (struct sockaddr_in6 *)args->address;
 444
 445                 servername[0] = '\0';
 446                 switch (args->address->sa_family) {
 447                 case AF_LOCAL:
 448                         snprintf(servername, sizeof(servername), "%s",
 449                                  sun->sun_path);
 450                         break;
 451                 case AF_INET:
 452                         snprintf(servername, sizeof(servername), "%pI4",
 453                                  &sin->sin_addr.s_addr);
 454                         break;
 455                 case AF_INET6:
 456                         snprintf(servername, sizeof(servername), "%pI6",
 457                                  &sin6->sin6_addr);
 458                         break;
 459                 default:
 460                         /* caller wants default server name, but
 461                          * address family isn't recognized. */
 462                         return ERR_PTR(-EINVAL);
 463                 }
 464                 xprtargs.servername = servername;
 465         }
 466
 467         xprt = xprt_create_transport(&xprtargs);
 468         if (IS_ERR(xprt))
 469                 return (struct rpc_clnt *)xprt;
 470
 471         /*
 472          * By default, kernel RPC client connects from a reserved port.
 473          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 474          * but it is always enabled for rpciod, which handles the connect
 475          * operation.
 476          */
 477         xprt->resvport = 1;
 478         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 479                 xprt->resvport = 0;
 480
 481         clnt = rpc_new_client(args, xprt);
 482         if (IS_ERR(clnt))
 483                 return clnt;
 484
 485         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 486                 int err = rpc_ping(clnt);
 487                 if (err != 0) {
 488                         rpc_shutdown_client(clnt);
 489                         return ERR_PTR(err);
 490                 }
 491         }
 492
 493         clnt->cl_softrtry = 1;
 494         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 495                 clnt->cl_softrtry = 0;
 496
 497         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 498                 clnt->cl_autobind = 1;
 499         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 500                 clnt->cl_discrtry = 1;
 501         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 502                 clnt->cl_chatty = 1;
 503
 504         return clnt;
 505 }
 506 EXPORT_SYMBOL_GPL(rpc_create);
 507
 508 /*
 509  * This function clones the RPC client structure. It allows us to share the
 510  * same transport while varying parameters such as the authentication
 511  * flavour.
 512  */
 513 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 514                                            struct rpc_clnt *clnt)
 515 {
 516         struct rpc_xprt *xprt;
 517         struct rpc_clnt *new;
 518         int err;
 519
 520         err = -ENOMEM;
 521         rcu_read_lock();
 522         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 523         rcu_read_unlock();
 524         if (xprt == NULL)
 525                 goto out_err;
 526         args->servername = xprt->servername;
 527
 528         new = rpc_new_client(args, xprt);
 529         if (IS_ERR(new)) {
 530                 err = PTR_ERR(new);
 531                 goto out_err;
 532         }
 533
 534         atomic_inc(&clnt->cl_count);
 535         new->cl_parent = clnt;
 536
 537         /* Turn off autobind on clones */
 538         new->cl_autobind = 0;
 539         new->cl_softrtry = clnt->cl_softrtry;
 540         new->cl_discrtry = clnt->cl_discrtry;
 541         new->cl_chatty = clnt->cl_chatty;
 542         return new;
 543
 544 out_err:
 545         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 546         return ERR_PTR(err);
 547 }
 548
 549 /**
 550  * rpc_clone_client - Clone an RPC client structure
 551  *
 552  * @clnt: RPC client whose parameters are copied
 553  *
 554  * Returns a fresh RPC client or an ERR_PTR.
 555  */
 556 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 557 {
 558         struct rpc_create_args args = {
 559                 .program        = clnt->cl_program,
 560                 .prognumber     = clnt->cl_prog,
 561                 .version        = clnt->cl_vers,
 562                 .authflavor     = clnt->cl_auth->au_flavor,
 563                 .client_name    = clnt->cl_principal,
 564         };
 565         return __rpc_clone_client(&args, clnt);
 566 }
 567 EXPORT_SYMBOL_GPL(rpc_clone_client);
 568
 569 /**
 570  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 571  *
 572  * @clnt: RPC client whose parameters are copied
 573  * @flavor: security flavor for new client
 574  *
 575  * Returns a fresh RPC client or an ERR_PTR.
 576  */
 577 struct rpc_clnt *
 578 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 579 {
 580         struct rpc_create_args args = {
 581                 .program        = clnt->cl_program,
 582                 .prognumber     = clnt->cl_prog,
 583                 .version        = clnt->cl_vers,
 584                 .authflavor     = flavor,
 585                 .client_name    = clnt->cl_principal,
 586         };
 587         return __rpc_clone_client(&args, clnt);
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 590
 591 /*
 592  * Kill all tasks for the given client.
 593  * XXX: kill their descendants as well?
 594  */
 595 void rpc_killall_tasks(struct rpc_clnt *clnt)
 596 {
 597         struct rpc_task *rovr;
 598
 599
 600         if (list_empty(&clnt->cl_tasks))
 601                 return;
 602         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 603         /*
 604          * Spin lock all_tasks to prevent changes...
 605          */
 606         spin_lock(&clnt->cl_lock);
 607         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 608                 if (!RPC_IS_ACTIVATED(rovr))
 609                         continue;
 610                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 611                         rovr->tk_flags |= RPC_TASK_KILLED;
 612                         rpc_exit(rovr, -EIO);
 613                         if (RPC_IS_QUEUED(rovr))
 614                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 615                                                         rovr);
 616                 }
 617         }
 618         spin_unlock(&clnt->cl_lock);
 619 }
 620 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 621
 622 /*
 623  * Properly shut down an RPC client, terminating all outstanding
 624  * requests.
 625  */
 626 void rpc_shutdown_client(struct rpc_clnt *clnt)
 627 {
 628         might_sleep();
 629
 630         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 631                         clnt->cl_protname,
 632                         rcu_dereference(clnt->cl_xprt)->servername);
 633
 634         while (!list_empty(&clnt->cl_tasks)) {
 635                 rpc_killall_tasks(clnt);
 636                 wait_event_timeout(destroy_wait,
 637                         list_empty(&clnt->cl_tasks), 1*HZ);
 638         }
 639
 640         rpc_release_client(clnt);
 641 }
 642 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 643
 644 /*
 645  * Free an RPC client
 646  */
 647 static void
 648 rpc_free_client(struct rpc_clnt *clnt)
 649 {
 650         dprintk_rcu("RPC:       destroying %s client for %s\n",
 651                         clnt->cl_protname,
 652                         rcu_dereference(clnt->cl_xprt)->servername);
 653         if (clnt->cl_parent != clnt)
 654                 rpc_release_client(clnt->cl_parent);
 655         rpc_clnt_remove_pipedir(clnt);
 656         rpc_unregister_client(clnt);
 657         rpc_free_iostats(clnt->cl_metrics);
 658         kfree(clnt->cl_principal);
 659         clnt->cl_metrics = NULL;
 660         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 661         rpciod_down();
 662         kfree(clnt);
 663 }
 664
 665 /*
 666  * Free an RPC client
 667  */
 668 static void
 669 rpc_free_auth(struct rpc_clnt *clnt)
 670 {
 671         if (clnt->cl_auth == NULL) {
 672                 rpc_free_client(clnt);
 673                 return;
 674         }
 675
 676         /*
 677          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 678          *       release remaining GSS contexts. This mechanism ensures
 679          *       that it can do so safely.
 680          */
 681         atomic_inc(&clnt->cl_count);
 682         rpcauth_release(clnt->cl_auth);
 683         clnt->cl_auth = NULL;
 684         if (atomic_dec_and_test(&clnt->cl_count))
 685                 rpc_free_client(clnt);
 686 }
 687
 688 /*
 689  * Release reference to the RPC client
 690  */
 691 void
 692 rpc_release_client(struct rpc_clnt *clnt)
 693 {
 694         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 695
 696         if (list_empty(&clnt->cl_tasks))
 697                 wake_up(&destroy_wait);
 698         if (atomic_dec_and_test(&clnt->cl_count))
 699                 rpc_free_auth(clnt);
 700 }
 701 EXPORT_SYMBOL_GPL(rpc_release_client);
 702
 703 /**
 704  * rpc_bind_new_program - bind a new RPC program to an existing client
 705  * @old: old rpc_client
 706  * @program: rpc program to set
 707  * @vers: rpc program version
 708  *
 709  * Clones the rpc client and sets up a new RPC program. This is mainly
 710  * of use for enabling different RPC programs to share the same transport.
 711  * The Sun NFSv2/v3 ACL protocol can do this.
 712  */
 713 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 714                                       const struct rpc_program *program,
 715                                       u32 vers)
 716 {
 717         struct rpc_create_args args = {
 718                 .program        = program,
 719                 .prognumber     = program->number,
 720                 .version        = vers,
 721                 .authflavor     = old->cl_auth->au_flavor,
 722                 .client_name    = old->cl_principal,
 723         };
 724         struct rpc_clnt *clnt;
 725         int err;
 726
 727         clnt = __rpc_clone_client(&args, old);
 728         if (IS_ERR(clnt))
 729                 goto out;
 730         err = rpc_ping(clnt);
 731         if (err != 0) {
 732                 rpc_shutdown_client(clnt);
 733                 clnt = ERR_PTR(err);
 734         }
 735 out:
 736         return clnt;
 737 }
 738 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 739
 740 void rpc_task_release_client(struct rpc_task *task)
 741 {
 742         struct rpc_clnt *clnt = task->tk_client;
 743
 744         if (clnt != NULL) {
 745                 /* Remove from client task list */
 746                 spin_lock(&clnt->cl_lock);
 747                 list_del(&task->tk_task);
 748                 spin_unlock(&clnt->cl_lock);
 749                 task->tk_client = NULL;
 750
 751                 rpc_release_client(clnt);
 752         }
 753 }
 754
 755 static
 756 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 757 {
 758         if (clnt != NULL) {
 759                 rpc_task_release_client(task);
 760                 task->tk_client = clnt;
 761                 atomic_inc(&clnt->cl_count);
 762                 if (clnt->cl_softrtry)
 763                         task->tk_flags |= RPC_TASK_SOFT;
 764                 if (sk_memalloc_socks()) {
 765                         struct rpc_xprt *xprt;
 766
 767                         rcu_read_lock();
 768                         xprt = rcu_dereference(clnt->cl_xprt);
 769                         if (xprt->swapper)
 770                                 task->tk_flags |= RPC_TASK_SWAPPER;
 771                         rcu_read_unlock();
 772                 }
 773                 /* Add to the client's list of all tasks */
 774                 spin_lock(&clnt->cl_lock);
 775                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 776                 spin_unlock(&clnt->cl_lock);
 777         }
 778 }
 779
 780 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 781 {
 782         rpc_task_release_client(task);
 783         rpc_task_set_client(task, clnt);
 784 }
 785 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 786
 787
 788 static void
 789 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 790 {
 791         if (msg != NULL) {
 792                 task->tk_msg.rpc_proc = msg->rpc_proc;
 793                 task->tk_msg.rpc_argp = msg->rpc_argp;
 794                 task->tk_msg.rpc_resp = msg->rpc_resp;
 795                 if (msg->rpc_cred != NULL)
 796                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 797         }
 798 }
 799
 800 /*
 801  * Default callback for async RPC calls
 802  */
 803 static void
 804 rpc_default_callback(struct rpc_task *task, void *data)
 805 {
 806 }
 807
 808 static const struct rpc_call_ops rpc_default_ops = {
 809         .rpc_call_done = rpc_default_callback,
 810 };
 811
 812 /**
 813  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 814  * @task_setup_data: pointer to task initialisation data
 815  */
 816 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 817 {
 818         struct rpc_task *task;
 819
 820         task = rpc_new_task(task_setup_data);
 821         if (IS_ERR(task))
 822                 goto out;
 823
 824         rpc_task_set_client(task, task_setup_data->rpc_client);
 825         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 826
 827         if (task->tk_action == NULL)
 828                 rpc_call_start(task);
 829
 830         atomic_inc(&task->tk_count);
 831         rpc_execute(task);
 832 out:
 833         return task;
 834 }
 835 EXPORT_SYMBOL_GPL(rpc_run_task);
 836
 837 /**
 838  * rpc_call_sync - Perform a synchronous RPC call
 839  * @clnt: pointer to RPC client
 840  * @msg: RPC call parameters
 841  * @flags: RPC call flags
 842  */
 843 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 844 {
 845         struct rpc_task *task;
 846         struct rpc_task_setup task_setup_data = {
 847                 .rpc_client = clnt,
 848                 .rpc_message = msg,
 849                 .callback_ops = &rpc_default_ops,
 850                 .flags = flags,
 851         };
 852         int status;
 853
 854         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 855         if (flags & RPC_TASK_ASYNC) {
 856                 rpc_release_calldata(task_setup_data.callback_ops,
 857                         task_setup_data.callback_data);
 858                 return -EINVAL;
 859         }
 860
 861         task = rpc_run_task(&task_setup_data);
 862         if (IS_ERR(task))
 863                 return PTR_ERR(task);
 864         status = task->tk_status;
 865         rpc_put_task(task);
 866         return status;
 867 }
 868 EXPORT_SYMBOL_GPL(rpc_call_sync);
 869
 870 /**
 871  * rpc_call_async - Perform an asynchronous RPC call
 872  * @clnt: pointer to RPC client
 873  * @msg: RPC call parameters
 874  * @flags: RPC call flags
 875  * @tk_ops: RPC call ops
 876  * @data: user call data
 877  */
 878 int
 879 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 880                const struct rpc_call_ops *tk_ops, void *data)
 881 {
 882         struct rpc_task *task;
 883         struct rpc_task_setup task_setup_data = {
 884                 .rpc_client = clnt,
 885                 .rpc_message = msg,
 886                 .callback_ops = tk_ops,
 887                 .callback_data = data,
 888                 .flags = flags|RPC_TASK_ASYNC,
 889         };
 890
 891         task = rpc_run_task(&task_setup_data);
 892         if (IS_ERR(task))
 893                 return PTR_ERR(task);
 894         rpc_put_task(task);
 895         return 0;
 896 }
 897 EXPORT_SYMBOL_GPL(rpc_call_async);
 898
 899 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 900 /**
 901  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 902  * rpc_execute against it
 903  * @req: RPC request
 904  * @tk_ops: RPC call ops
 905  */
 906 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 907                                 const struct rpc_call_ops *tk_ops)
 908 {
 909         struct rpc_task *task;
 910         struct xdr_buf *xbufp = &req->rq_snd_buf;
 911         struct rpc_task_setup task_setup_data = {
 912                 .callback_ops = tk_ops,
 913         };
 914
 915         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 916         /*
 917          * Create an rpc_task to send the data
 918          */
 919         task = rpc_new_task(&task_setup_data);
 920         if (IS_ERR(task)) {
 921                 xprt_free_bc_request(req);
 922                 goto out;
 923         }
 924         task->tk_rqstp = req;
 925
 926         /*
 927          * Set up the xdr_buf length.
 928          * This also indicates that the buffer is XDR encoded already.
 929          */
 930         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 931                         xbufp->tail[0].iov_len;
 932
 933         task->tk_action = call_bc_transmit;
 934         atomic_inc(&task->tk_count);
 935         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 936         rpc_execute(task);
 937
 938 out:
 939         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 940         return task;
 941 }
 942 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 943
 944 void
 945 rpc_call_start(struct rpc_task *task)
 946 {
 947         task->tk_action = call_start;
 948 }
 949 EXPORT_SYMBOL_GPL(rpc_call_start);
 950
 951 /**
 952  * rpc_peeraddr - extract remote peer address from clnt's xprt
 953  * @clnt: RPC client structure
 954  * @buf: target buffer
 955  * @bufsize: length of target buffer
 956  *
 957  * Returns the number of bytes that are actually in the stored address.
 958  */
 959 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 960 {
 961         size_t bytes;
 962         struct rpc_xprt *xprt;
 963
 964         rcu_read_lock();
 965         xprt = rcu_dereference(clnt->cl_xprt);
 966
 967         bytes = xprt->addrlen;
 968         if (bytes > bufsize)
 969                 bytes = bufsize;
 970         memcpy(buf, &xprt->addr, bytes);
 971         rcu_read_unlock();
 972
 973         return bytes;
 974 }
 975 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 976
 977 /**
 978  * rpc_peeraddr2str - return remote peer address in printable format
 979  * @clnt: RPC client structure
 980  * @format: address format
 981  *
 982  * NB: the lifetime of the memory referenced by the returned pointer is
 983  * the same as the rpc_xprt itself.  As long as the caller uses this
 984  * pointer, it must hold the RCU read lock.
 985  */
 986 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 987                              enum rpc_display_format_t format)
 988 {
 989         struct rpc_xprt *xprt;
 990
 991         xprt = rcu_dereference(clnt->cl_xprt);
 992
 993         if (xprt->address_strings[format] != NULL)
 994                 return xprt->address_strings[format];
 995         else
 996                 return "unprintable";
 997 }
 998 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 999
1000 static const struct sockaddr_in rpc_inaddr_loopback = {
1001         .sin_family             = AF_INET,
1002         .sin_addr.s_addr        = htonl(INADDR_ANY),
1003 };
1004
1005 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1006         .sin6_family            = AF_INET6,
1007         .sin6_addr              = IN6ADDR_ANY_INIT,
1008 };
1009
1010 /*
1011  * Try a getsockname() on a connected datagram socket.  Using a
1012  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1013  * This conserves the ephemeral port number space.
1014  *
1015  * Returns zero and fills in "buf" if successful; otherwise, a
1016  * negative errno is returned.
1017  */
1018 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1019                         struct sockaddr *buf, int buflen)
1020 {
1021         struct socket *sock;
1022         int err;
1023
1024         err = __sock_create(net, sap->sa_family,
1025                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1026         if (err < 0) {
1027                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1028                 goto out;
1029         }
1030
1031         switch (sap->sa_family) {
1032         case AF_INET:
1033                 err = kernel_bind(sock,
1034                                 (struct sockaddr *)&rpc_inaddr_loopback,
1035                                 sizeof(rpc_inaddr_loopback));
1036                 break;
1037         case AF_INET6:
1038                 err = kernel_bind(sock,
1039                                 (struct sockaddr *)&rpc_in6addr_loopback,
1040                                 sizeof(rpc_in6addr_loopback));
1041                 break;
1042         default:
1043                 err = -EAFNOSUPPORT;
1044                 goto out;
1045         }
1046         if (err < 0) {
1047                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1048                 goto out_release;
1049         }
1050
1051         err = kernel_connect(sock, sap, salen, 0);
1052         if (err < 0) {
1053                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1054                 goto out_release;
1055         }
1056
1057         err = kernel_getsockname(sock, buf, &buflen);
1058         if (err < 0) {
1059                 dprintk("RPC:       getsockname failed (%d)\n", err);
1060                 goto out_release;
1061         }
1062
1063         err = 0;
1064         if (buf->sa_family == AF_INET6) {
1065                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1066                 sin6->sin6_scope_id = 0;
1067         }
1068         dprintk("RPC:       %s succeeded\n", __func__);
1069
1070 out_release:
1071         sock_release(sock);
1072 out:
1073         return err;
1074 }
1075
1076 /*
1077  * Scraping a connected socket failed, so we don't have a useable
1078  * local address.  Fallback: generate an address that will prevent
1079  * the server from calling us back.
1080  *
1081  * Returns zero and fills in "buf" if successful; otherwise, a
1082  * negative errno is returned.
1083  */
1084 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1085 {
1086         switch (family) {
1087         case AF_INET:
1088                 if (buflen < sizeof(rpc_inaddr_loopback))
1089                         return -EINVAL;
1090                 memcpy(buf, &rpc_inaddr_loopback,
1091                                 sizeof(rpc_inaddr_loopback));
1092                 break;
1093         case AF_INET6:
1094                 if (buflen < sizeof(rpc_in6addr_loopback))
1095                         return -EINVAL;
1096                 memcpy(buf, &rpc_in6addr_loopback,
1097                                 sizeof(rpc_in6addr_loopback));
1098         default:
1099                 dprintk("RPC:       %s: address family not supported\n",
1100                         __func__);
1101                 return -EAFNOSUPPORT;
1102         }
1103         dprintk("RPC:       %s: succeeded\n", __func__);
1104         return 0;
1105 }
1106
1107 /**
1108  * rpc_localaddr - discover local endpoint address for an RPC client
1109  * @clnt: RPC client structure
1110  * @buf: target buffer
1111  * @buflen: size of target buffer, in bytes
1112  *
1113  * Returns zero and fills in "buf" and "buflen" if successful;
1114  * otherwise, a negative errno is returned.
1115  *
1116  * This works even if the underlying transport is not currently connected,
1117  * or if the upper layer never previously provided a source address.
1118  *
1119  * The result of this function call is transient: multiple calls in
1120  * succession may give different results, depending on how local
1121  * networking configuration changes over time.
1122  */
1123 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1124 {
1125         struct sockaddr_storage address;
1126         struct sockaddr *sap = (struct sockaddr *)&address;
1127         struct rpc_xprt *xprt;
1128         struct net *net;
1129         size_t salen;
1130         int err;
1131
1132         rcu_read_lock();
1133         xprt = rcu_dereference(clnt->cl_xprt);
1134         salen = xprt->addrlen;
1135         memcpy(sap, &xprt->addr, salen);
1136         net = get_net(xprt->xprt_net);
1137         rcu_read_unlock();
1138
1139         rpc_set_port(sap, 0);
1140         err = rpc_sockname(net, sap, salen, buf, buflen);
1141         put_net(net);
1142         if (err != 0)
1143                 /* Couldn't discover local address, return ANYADDR */
1144                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1145         return 0;
1146 }
1147 EXPORT_SYMBOL_GPL(rpc_localaddr);
1148
1149 void
1150 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1151 {
1152         struct rpc_xprt *xprt;
1153
1154         rcu_read_lock();
1155         xprt = rcu_dereference(clnt->cl_xprt);
1156         if (xprt->ops->set_buffer_size)
1157                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1158         rcu_read_unlock();
1159 }
1160 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1161
1162 /**
1163  * rpc_protocol - Get transport protocol number for an RPC client
1164  * @clnt: RPC client to query
1165  *
1166  */
1167 int rpc_protocol(struct rpc_clnt *clnt)
1168 {
1169         int protocol;
1170
1171         rcu_read_lock();
1172         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1173         rcu_read_unlock();
1174         return protocol;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_protocol);
1177
1178 /**
1179  * rpc_net_ns - Get the network namespace for this RPC client
1180  * @clnt: RPC client to query
1181  *
1182  */
1183 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1184 {
1185         struct net *ret;
1186
1187         rcu_read_lock();
1188         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1189         rcu_read_unlock();
1190         return ret;
1191 }
1192 EXPORT_SYMBOL_GPL(rpc_net_ns);
1193
1194 /**
1195  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1196  * @clnt: RPC client to query
1197  *
1198  * For stream transports, this is one RPC record fragment (see RFC
1199  * 1831), as we don't support multi-record requests yet.  For datagram
1200  * transports, this is the size of an IP packet minus the IP, UDP, and
1201  * RPC header sizes.
1202  */
1203 size_t rpc_max_payload(struct rpc_clnt *clnt)
1204 {
1205         size_t ret;
1206
1207         rcu_read_lock();
1208         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1209         rcu_read_unlock();
1210         return ret;
1211 }
1212 EXPORT_SYMBOL_GPL(rpc_max_payload);
1213
1214 /**
1215  * rpc_get_timeout - Get timeout for transport in units of HZ
1216  * @clnt: RPC client to query
1217  */
1218 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1219 {
1220         unsigned long ret;
1221
1222         rcu_read_lock();
1223         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1224         rcu_read_unlock();
1225         return ret;
1226 }
1227 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1228
1229 /**
1230  * rpc_force_rebind - force transport to check that remote port is unchanged
1231  * @clnt: client to rebind
1232  *
1233  */
1234 void rpc_force_rebind(struct rpc_clnt *clnt)
1235 {
1236         if (clnt->cl_autobind) {
1237                 rcu_read_lock();
1238                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1239                 rcu_read_unlock();
1240         }
1241 }
1242 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1243
1244 /*
1245  * Restart an (async) RPC call from the call_prepare state.
1246  * Usually called from within the exit handler.
1247  */
1248 int
1249 rpc_restart_call_prepare(struct rpc_task *task)
1250 {
1251         if (RPC_ASSASSINATED(task))
1252                 return 0;
1253         task->tk_action = call_start;
1254         if (task->tk_ops->rpc_call_prepare != NULL)
1255                 task->tk_action = rpc_prepare_task;
1256         return 1;
1257 }
1258 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1259
1260 /*
1261  * Restart an (async) RPC call. Usually called from within the
1262  * exit handler.
1263  */
1264 int
1265 rpc_restart_call(struct rpc_task *task)
1266 {
1267         if (RPC_ASSASSINATED(task))
1268                 return 0;
1269         task->tk_action = call_start;
1270         return 1;
1271 }
1272 EXPORT_SYMBOL_GPL(rpc_restart_call);
1273
1274 #ifdef RPC_DEBUG
1275 static const char *rpc_proc_name(const struct rpc_task *task)
1276 {
1277         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1278
1279         if (proc) {
1280                 if (proc->p_name)
1281                         return proc->p_name;
1282                 else
1283                         return "NULL";
1284         } else
1285                 return "no proc";
1286 }
1287 #endif
1288
1289 /*
1290  * 0.  Initial state
1291  *
1292  *     Other FSM states can be visited zero or more times, but
1293  *     this state is visited exactly once for each RPC.
1294  */
1295 static void
1296 call_start(struct rpc_task *task)
1297 {
1298         struct rpc_clnt *clnt = task->tk_client;
1299
1300         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1301                         clnt->cl_protname, clnt->cl_vers,
1302                         rpc_proc_name(task),
1303                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1304
1305         /* Increment call count */
1306         task->tk_msg.rpc_proc->p_count++;
1307         clnt->cl_stats->rpccnt++;
1308         task->tk_action = call_reserve;
1309 }
1310
1311 /*
1312  * 1.   Reserve an RPC call slot
1313  */
1314 static void
1315 call_reserve(struct rpc_task *task)
1316 {
1317         dprint_status(task);
1318
1319         task->tk_status  = 0;
1320         task->tk_action  = call_reserveresult;
1321         xprt_reserve(task);
1322 }
1323
1324 static void call_retry_reserve(struct rpc_task *task);
1325
1326 /*
1327  * 1b.  Grok the result of xprt_reserve()
1328  */
1329 static void
1330 call_reserveresult(struct rpc_task *task)
1331 {
1332         int status = task->tk_status;
1333
1334         dprint_status(task);
1335
1336         /*
1337          * After a call to xprt_reserve(), we must have either
1338          * a request slot or else an error status.
1339          */
1340         task->tk_status = 0;
1341         if (status >= 0) {
1342                 if (task->tk_rqstp) {
1343                         task->tk_action = call_refresh;
1344                         return;
1345                 }
1346
1347                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1348                                 __func__, status);
1349                 rpc_exit(task, -EIO);
1350                 return;
1351         }
1352
1353         /*
1354          * Even though there was an error, we may have acquired
1355          * a request slot somehow.  Make sure not to leak it.
1356          */
1357         if (task->tk_rqstp) {
1358                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1359                                 __func__, status);
1360                 xprt_release(task);
1361         }
1362
1363         switch (status) {
1364         case -ENOMEM:
1365                 rpc_delay(task, HZ >> 2);
1366         case -EAGAIN:   /* woken up; retry */
1367                 task->tk_action = call_retry_reserve;
1368                 return;
1369         case -EIO:      /* probably a shutdown */
1370                 break;
1371         default:
1372                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1373                                 __func__, status);
1374                 break;
1375         }
1376         rpc_exit(task, status);
1377 }
1378
1379 /*
1380  * 1c.  Retry reserving an RPC call slot
1381  */
1382 static void
1383 call_retry_reserve(struct rpc_task *task)
1384 {
1385         dprint_status(task);
1386
1387         task->tk_status  = 0;
1388         task->tk_action  = call_reserveresult;
1389         xprt_retry_reserve(task);
1390 }
1391
1392 /*
1393  * 2.   Bind and/or refresh the credentials
1394  */
1395 static void
1396 call_refresh(struct rpc_task *task)
1397 {
1398         dprint_status(task);
1399
1400         task->tk_action = call_refreshresult;
1401         task->tk_status = 0;
1402         task->tk_client->cl_stats->rpcauthrefresh++;
1403         rpcauth_refreshcred(task);
1404 }
1405
1406 /*
1407  * 2a.  Process the results of a credential refresh
1408  */
1409 static void
1410 call_refreshresult(struct rpc_task *task)
1411 {
1412         int status = task->tk_status;
1413
1414         dprint_status(task);
1415
1416         task->tk_status = 0;
1417         task->tk_action = call_refresh;
1418         switch (status) {
1419         case 0:
1420                 if (rpcauth_uptodatecred(task))
1421                         task->tk_action = call_allocate;
1422                 return;
1423         case -ETIMEDOUT:
1424                 rpc_delay(task, 3*HZ);
1425         case -EKEYEXPIRED:
1426         case -EAGAIN:
1427                 status = -EACCES;
1428                 if (!task->tk_cred_retry)
1429                         break;
1430                 task->tk_cred_retry--;
1431                 dprintk("RPC: %5u %s: retry refresh creds\n",
1432                                 task->tk_pid, __func__);
1433                 return;
1434         }
1435         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1436                                 task->tk_pid, __func__, status);
1437         rpc_exit(task, status);
1438 }
1439
1440 /*
1441  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1442  *      (Note: buffer memory is freed in xprt_release).
1443  */
1444 static void
1445 call_allocate(struct rpc_task *task)
1446 {
1447         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1448         struct rpc_rqst *req = task->tk_rqstp;
1449         struct rpc_xprt *xprt = req->rq_xprt;
1450         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1451
1452         dprint_status(task);
1453
1454         task->tk_status = 0;
1455         task->tk_action = call_bind;
1456
1457         if (req->rq_buffer)
1458                 return;
1459
1460         if (proc->p_proc != 0) {
1461                 BUG_ON(proc->p_arglen == 0);
1462                 if (proc->p_decode != NULL)
1463                         BUG_ON(proc->p_replen == 0);
1464         }
1465
1466         /*
1467          * Calculate the size (in quads) of the RPC call
1468          * and reply headers, and convert both values
1469          * to byte sizes.
1470          */
1471         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1472         req->rq_callsize <<= 2;
1473         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1474         req->rq_rcvsize <<= 2;
1475
1476         req->rq_buffer = xprt->ops->buf_alloc(task,
1477                                         req->rq_callsize + req->rq_rcvsize);
1478         if (req->rq_buffer != NULL)
1479                 return;
1480
1481         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1482
1483         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1484                 task->tk_action = call_allocate;
1485                 rpc_delay(task, HZ>>4);
1486                 return;
1487         }
1488
1489         rpc_exit(task, -ERESTARTSYS);
1490 }
1491
1492 static inline int
1493 rpc_task_need_encode(struct rpc_task *task)
1494 {
1495         return task->tk_rqstp->rq_snd_buf.len == 0;
1496 }
1497
1498 static inline void
1499 rpc_task_force_reencode(struct rpc_task *task)
1500 {
1501         task->tk_rqstp->rq_snd_buf.len = 0;
1502         task->tk_rqstp->rq_bytes_sent = 0;
1503 }
1504
1505 static inline void
1506 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1507 {
1508         buf->head[0].iov_base = start;
1509         buf->head[0].iov_len = len;
1510         buf->tail[0].iov_len = 0;
1511         buf->page_len = 0;
1512         buf->flags = 0;
1513         buf->len = 0;
1514         buf->buflen = len;
1515 }
1516
1517 /*
1518  * 3.   Encode arguments of an RPC call
1519  */
1520 static void
1521 rpc_xdr_encode(struct rpc_task *task)
1522 {
1523         struct rpc_rqst *req = task->tk_rqstp;
1524         kxdreproc_t     encode;
1525         __be32          *p;
1526
1527         dprint_status(task);
1528
1529         rpc_xdr_buf_init(&req->rq_snd_buf,
1530                          req->rq_buffer,
1531                          req->rq_callsize);
1532         rpc_xdr_buf_init(&req->rq_rcv_buf,
1533                          (char *)req->rq_buffer + req->rq_callsize,
1534                          req->rq_rcvsize);
1535
1536         p = rpc_encode_header(task);
1537         if (p == NULL) {
1538                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1539                 rpc_exit(task, -EIO);
1540                 return;
1541         }
1542
1543         encode = task->tk_msg.rpc_proc->p_encode;
1544         if (encode == NULL)
1545                 return;
1546
1547         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1548                         task->tk_msg.rpc_argp);
1549 }
1550
1551 /*
1552  * 4.   Get the server port number if not yet set
1553  */
1554 static void
1555 call_bind(struct rpc_task *task)
1556 {
1557         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1558
1559         dprint_status(task);
1560
1561         task->tk_action = call_connect;
1562         if (!xprt_bound(xprt)) {
1563                 task->tk_action = call_bind_status;
1564                 task->tk_timeout = xprt->bind_timeout;
1565                 xprt->ops->rpcbind(task);
1566         }
1567 }
1568
1569 /*
1570  * 4a.  Sort out bind result
1571  */
1572 static void
1573 call_bind_status(struct rpc_task *task)
1574 {
1575         int status = -EIO;
1576
1577         if (task->tk_status >= 0) {
1578                 dprint_status(task);
1579                 task->tk_status = 0;
1580                 task->tk_action = call_connect;
1581                 return;
1582         }
1583
1584         trace_rpc_bind_status(task);
1585         switch (task->tk_status) {
1586         case -ENOMEM:
1587                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1588                 rpc_delay(task, HZ >> 2);
1589                 goto retry_timeout;
1590         case -EACCES:
1591                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1592                                 "unavailable\n", task->tk_pid);
1593                 /* fail immediately if this is an RPC ping */
1594                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1595                         status = -EOPNOTSUPP;
1596                         break;
1597                 }
1598                 if (task->tk_rebind_retry == 0)
1599                         break;
1600                 task->tk_rebind_retry--;
1601                 rpc_delay(task, 3*HZ);
1602                 goto retry_timeout;
1603         case -ETIMEDOUT:
1604                 dprintk("RPC: %5u rpcbind request timed out\n",
1605                                 task->tk_pid);
1606                 goto retry_timeout;
1607         case -EPFNOSUPPORT:
1608                 /* server doesn't support any rpcbind version we know of */
1609                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1610                                 task->tk_pid);
1611                 break;
1612         case -EPROTONOSUPPORT:
1613                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1614                                 task->tk_pid);
1615                 task->tk_status = 0;
1616                 task->tk_action = call_bind;
1617                 return;
1618         case -ECONNREFUSED:             /* connection problems */
1619         case -ECONNRESET:
1620         case -ENOTCONN:
1621         case -EHOSTDOWN:
1622         case -EHOSTUNREACH:
1623         case -ENETUNREACH:
1624         case -EPIPE:
1625                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1626                                 task->tk_pid, task->tk_status);
1627                 if (!RPC_IS_SOFTCONN(task)) {
1628                         rpc_delay(task, 5*HZ);
1629                         goto retry_timeout;
1630                 }
1631                 status = task->tk_status;
1632                 break;
1633         default:
1634                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1635                                 task->tk_pid, -task->tk_status);
1636         }
1637
1638         rpc_exit(task, status);
1639         return;
1640
1641 retry_timeout:
1642         task->tk_action = call_timeout;
1643 }
1644
1645 /*
1646  * 4b.  Connect to the RPC server
1647  */
1648 static void
1649 call_connect(struct rpc_task *task)
1650 {
1651         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1652
1653         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1654                         task->tk_pid, xprt,
1655                         (xprt_connected(xprt) ? "is" : "is not"));
1656
1657         task->tk_action = call_transmit;
1658         if (!xprt_connected(xprt)) {
1659                 task->tk_action = call_connect_status;
1660                 if (task->tk_status < 0)
1661                         return;
1662                 xprt_connect(task);
1663         }
1664 }
1665
1666 /*
1667  * 4c.  Sort out connect result
1668  */
1669 static void
1670 call_connect_status(struct rpc_task *task)
1671 {
1672         struct rpc_clnt *clnt = task->tk_client;
1673         int status = task->tk_status;
1674
1675         dprint_status(task);
1676
1677         trace_rpc_connect_status(task, status);
1678         switch (status) {
1679                 /* if soft mounted, test if we've timed out */
1680         case -ETIMEDOUT:
1681                 task->tk_action = call_timeout;
1682                 return;
1683         case -ECONNREFUSED:
1684         case -ECONNRESET:
1685         case -ENETUNREACH:
1686                 if (RPC_IS_SOFTCONN(task))
1687                         break;
1688                 /* retry with existing socket, after a delay */
1689         case 0:
1690         case -EAGAIN:
1691                 task->tk_status = 0;
1692                 clnt->cl_stats->netreconn++;
1693                 task->tk_action = call_transmit;
1694                 return;
1695         }
1696         rpc_exit(task, status);
1697 }
1698
1699 /*
1700  * 5.   Transmit the RPC request, and wait for reply
1701  */
1702 static void
1703 call_transmit(struct rpc_task *task)
1704 {
1705         dprint_status(task);
1706
1707         task->tk_action = call_status;
1708         if (task->tk_status < 0)
1709                 return;
1710         task->tk_status = xprt_prepare_transmit(task);
1711         if (task->tk_status != 0)
1712                 return;
1713         task->tk_action = call_transmit_status;
1714         /* Encode here so that rpcsec_gss can use correct sequence number. */
1715         if (rpc_task_need_encode(task)) {
1716                 rpc_xdr_encode(task);
1717                 /* Did the encode result in an error condition? */
1718                 if (task->tk_status != 0) {
1719                         /* Was the error nonfatal? */
1720                         if (task->tk_status == -EAGAIN)
1721                                 rpc_delay(task, HZ >> 4);
1722                         else
1723                                 rpc_exit(task, task->tk_status);
1724                         return;
1725                 }
1726         }
1727         xprt_transmit(task);
1728         if (task->tk_status < 0)
1729                 return;
1730         /*
1731          * On success, ensure that we call xprt_end_transmit() before sleeping
1732          * in order to allow access to the socket to other RPC requests.
1733          */
1734         call_transmit_status(task);
1735         if (rpc_reply_expected(task))
1736                 return;
1737         task->tk_action = rpc_exit_task;
1738         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1739 }
1740
1741 /*
1742  * 5a.  Handle cleanup after a transmission
1743  */
1744 static void
1745 call_transmit_status(struct rpc_task *task)
1746 {
1747         task->tk_action = call_status;
1748
1749         /*
1750          * Common case: success.  Force the compiler to put this
1751          * test first.
1752          */
1753         if (task->tk_status == 0) {
1754                 xprt_end_transmit(task);
1755                 rpc_task_force_reencode(task);
1756                 return;
1757         }
1758
1759         switch (task->tk_status) {
1760         case -EAGAIN:
1761                 break;
1762         default:
1763                 dprint_status(task);
1764                 xprt_end_transmit(task);
1765                 rpc_task_force_reencode(task);
1766                 break;
1767                 /*
1768                  * Special cases: if we've been waiting on the
1769                  * socket's write_space() callback, or if the
1770                  * socket just returned a connection error,
1771                  * then hold onto the transport lock.
1772                  */
1773         case -ECONNREFUSED:
1774         case -EHOSTDOWN:
1775         case -EHOSTUNREACH:
1776         case -ENETUNREACH:
1777                 if (RPC_IS_SOFTCONN(task)) {
1778                         xprt_end_transmit(task);
1779                         rpc_exit(task, task->tk_status);
1780                         break;
1781                 }
1782         case -ECONNRESET:
1783         case -ENOTCONN:
1784         case -EPIPE:
1785                 rpc_task_force_reencode(task);
1786         }
1787 }
1788
1789 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1790 /*
1791  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1792  * addition, disconnect on connectivity errors.
1793  */
1794 static void
1795 call_bc_transmit(struct rpc_task *task)
1796 {
1797         struct rpc_rqst *req = task->tk_rqstp;
1798
1799         task->tk_status = xprt_prepare_transmit(task);
1800         if (task->tk_status == -EAGAIN) {
1801                 /*
1802                  * Could not reserve the transport. Try again after the
1803                  * transport is released.
1804                  */
1805                 task->tk_status = 0;
1806                 task->tk_action = call_bc_transmit;
1807                 return;
1808         }
1809
1810         task->tk_action = rpc_exit_task;
1811         if (task->tk_status < 0) {
1812                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1813                         "error: %d\n", task->tk_status);
1814                 return;
1815         }
1816
1817         xprt_transmit(task);
1818         xprt_end_transmit(task);
1819         dprint_status(task);
1820         switch (task->tk_status) {
1821         case 0:
1822                 /* Success */
1823                 break;
1824         case -EHOSTDOWN:
1825         case -EHOSTUNREACH:
1826         case -ENETUNREACH:
1827         case -ETIMEDOUT:
1828                 /*
1829                  * Problem reaching the server.  Disconnect and let the
1830                  * forechannel reestablish the connection.  The server will
1831                  * have to retransmit the backchannel request and we'll
1832                  * reprocess it.  Since these ops are idempotent, there's no
1833                  * need to cache our reply at this time.
1834                  */
1835                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1836                         "error: %d\n", task->tk_status);
1837                 xprt_conditional_disconnect(req->rq_xprt,
1838                         req->rq_connect_cookie);
1839                 break;
1840         default:
1841                 /*
1842                  * We were unable to reply and will have to drop the
1843                  * request.  The server should reconnect and retransmit.
1844                  */
1845                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1846                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1847                         "error: %d\n", task->tk_status);
1848                 break;
1849         }
1850         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1851 }
1852 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1853
1854 /*
1855  * 6.   Sort out the RPC call status
1856  */
1857 static void
1858 call_status(struct rpc_task *task)
1859 {
1860         struct rpc_clnt *clnt = task->tk_client;
1861         struct rpc_rqst *req = task->tk_rqstp;
1862         int             status;
1863
1864         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1865                 task->tk_status = req->rq_reply_bytes_recvd;
1866
1867         dprint_status(task);
1868
1869         status = task->tk_status;
1870         if (status >= 0) {
1871                 task->tk_action = call_decode;
1872                 return;
1873         }
1874
1875         trace_rpc_call_status(task);
1876         task->tk_status = 0;
1877         switch(status) {
1878         case -EHOSTDOWN:
1879         case -EHOSTUNREACH:
1880         case -ENETUNREACH:
1881                 /*
1882                  * Delay any retries for 3 seconds, then handle as if it
1883                  * were a timeout.
1884                  */
1885                 rpc_delay(task, 3*HZ);
1886         case -ETIMEDOUT:
1887                 task->tk_action = call_timeout;
1888                 if (task->tk_client->cl_discrtry)
1889                         xprt_conditional_disconnect(req->rq_xprt,
1890                                         req->rq_connect_cookie);
1891                 break;
1892         case -ECONNRESET:
1893         case -ECONNREFUSED:
1894                 rpc_force_rebind(clnt);
1895                 rpc_delay(task, 3*HZ);
1896         case -EPIPE:
1897         case -ENOTCONN:
1898                 task->tk_action = call_bind;
1899                 break;
1900         case -EAGAIN:
1901                 task->tk_action = call_transmit;
1902                 break;
1903         case -EIO:
1904                 /* shutdown or soft timeout */
1905                 rpc_exit(task, status);
1906                 break;
1907         default:
1908                 if (clnt->cl_chatty)
1909                         printk("%s: RPC call returned error %d\n",
1910                                clnt->cl_protname, -status);
1911                 rpc_exit(task, status);
1912         }
1913 }
1914
1915 /*
1916  * 6a.  Handle RPC timeout
1917  *      We do not release the request slot, so we keep using the
1918  *      same XID for all retransmits.
1919  */
1920 static void
1921 call_timeout(struct rpc_task *task)
1922 {
1923         struct rpc_clnt *clnt = task->tk_client;
1924
1925         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1926                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1927                 goto retry;
1928         }
1929
1930         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1931         task->tk_timeouts++;
1932
1933         if (RPC_IS_SOFTCONN(task)) {
1934                 rpc_exit(task, -ETIMEDOUT);
1935                 return;
1936         }
1937         if (RPC_IS_SOFT(task)) {
1938                 if (clnt->cl_chatty) {
1939                         rcu_read_lock();
1940                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1941                                 clnt->cl_protname,
1942                                 rcu_dereference(clnt->cl_xprt)->servername);
1943                         rcu_read_unlock();
1944                 }
1945                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1946                         rpc_exit(task, -ETIMEDOUT);
1947                 else
1948                         rpc_exit(task, -EIO);
1949                 return;
1950         }
1951
1952         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1953                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1954                 if (clnt->cl_chatty) {
1955                         rcu_read_lock();
1956                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1957                         clnt->cl_protname,
1958                         rcu_dereference(clnt->cl_xprt)->servername);
1959                         rcu_read_unlock();
1960                 }
1961         }
1962         rpc_force_rebind(clnt);
1963         /*
1964          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1965          * event? RFC2203 requires the server to drop all such requests.
1966          */
1967         rpcauth_invalcred(task);
1968
1969 retry:
1970         clnt->cl_stats->rpcretrans++;
1971         task->tk_action = call_bind;
1972         task->tk_status = 0;
1973 }
1974
1975 /*
1976  * 7.   Decode the RPC reply
1977  */
1978 static void
1979 call_decode(struct rpc_task *task)
1980 {
1981         struct rpc_clnt *clnt = task->tk_client;
1982         struct rpc_rqst *req = task->tk_rqstp;
1983         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1984         __be32          *p;
1985
1986         dprint_status(task);
1987
1988         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1989                 if (clnt->cl_chatty) {
1990                         rcu_read_lock();
1991                         printk(KERN_NOTICE "%s: server %s OK\n",
1992                                 clnt->cl_protname,
1993                                 rcu_dereference(clnt->cl_xprt)->servername);
1994                         rcu_read_unlock();
1995                 }
1996                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1997         }
1998
1999         /*
2000          * Ensure that we see all writes made by xprt_complete_rqst()
2001          * before it changed req->rq_reply_bytes_recvd.
2002          */
2003         smp_rmb();
2004         req->rq_rcv_buf.len = req->rq_private_buf.len;
2005
2006         /* Check that the softirq receive buffer is valid */
2007         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2008                                 sizeof(req->rq_rcv_buf)) != 0);
2009
2010         if (req->rq_rcv_buf.len < 12) {
2011                 if (!RPC_IS_SOFT(task)) {
2012                         task->tk_action = call_bind;
2013                         clnt->cl_stats->rpcretrans++;
2014                         goto out_retry;
2015                 }
2016                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2017                                 clnt->cl_protname, task->tk_status);
2018                 task->tk_action = call_timeout;
2019                 goto out_retry;
2020         }
2021
2022         p = rpc_verify_header(task);
2023         if (IS_ERR(p)) {
2024                 if (p == ERR_PTR(-EAGAIN))
2025                         goto out_retry;
2026                 return;
2027         }
2028
2029         task->tk_action = rpc_exit_task;
2030
2031         if (decode) {
2032                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2033                                                       task->tk_msg.rpc_resp);
2034         }
2035         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2036                         task->tk_status);
2037         return;
2038 out_retry:
2039         task->tk_status = 0;
2040         /* Note: rpc_verify_header() may have freed the RPC slot */
2041         if (task->tk_rqstp == req) {
2042                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2043                 if (task->tk_client->cl_discrtry)
2044                         xprt_conditional_disconnect(req->rq_xprt,
2045                                         req->rq_connect_cookie);
2046         }
2047 }
2048
2049 static __be32 *
2050 rpc_encode_header(struct rpc_task *task)
2051 {
2052         struct rpc_clnt *clnt = task->tk_client;
2053         struct rpc_rqst *req = task->tk_rqstp;
2054         __be32          *p = req->rq_svec[0].iov_base;
2055
2056         /* FIXME: check buffer size? */
2057
2058         p = xprt_skip_transport_header(req->rq_xprt, p);
2059         *p++ = req->rq_xid;             /* XID */
2060         *p++ = htonl(RPC_CALL);         /* CALL */
2061         *p++ = htonl(RPC_VERSION);      /* RPC version */
2062         *p++ = htonl(clnt->cl_prog);    /* program number */
2063         *p++ = htonl(clnt->cl_vers);    /* program version */
2064         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2065         p = rpcauth_marshcred(task, p);
2066         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2067         return p;
2068 }
2069
2070 static __be32 *
2071 rpc_verify_header(struct rpc_task *task)
2072 {
2073         struct rpc_clnt *clnt = task->tk_client;
2074         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2075         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2076         __be32  *p = iov->iov_base;
2077         u32 n;
2078         int error = -EACCES;
2079
2080         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2081                 /* RFC-1014 says that the representation of XDR data must be a
2082                  * multiple of four bytes
2083                  * - if it isn't pointer subtraction in the NFS client may give
2084                  *   undefined results
2085                  */
2086                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2087                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2088                        task->tk_rqstp->rq_rcv_buf.len);
2089                 goto out_eio;
2090         }
2091         if ((len -= 3) < 0)
2092                 goto out_overflow;
2093
2094         p += 1; /* skip XID */
2095         if ((n = ntohl(*p++)) != RPC_REPLY) {
2096                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2097                         task->tk_pid, __func__, n);
2098                 goto out_garbage;
2099         }
2100
2101         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2102                 if (--len < 0)
2103                         goto out_overflow;
2104                 switch ((n = ntohl(*p++))) {
2105                 case RPC_AUTH_ERROR:
2106                         break;
2107                 case RPC_MISMATCH:
2108                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2109                                 task->tk_pid, __func__);
2110                         error = -EPROTONOSUPPORT;
2111                         goto out_err;
2112                 default:
2113                         dprintk("RPC: %5u %s: RPC call rejected, "
2114                                 "unknown error: %x\n",
2115                                 task->tk_pid, __func__, n);
2116                         goto out_eio;
2117                 }
2118                 if (--len < 0)
2119                         goto out_overflow;
2120                 switch ((n = ntohl(*p++))) {
2121                 case RPC_AUTH_REJECTEDCRED:
2122                 case RPC_AUTH_REJECTEDVERF:
2123                 case RPCSEC_GSS_CREDPROBLEM:
2124                 case RPCSEC_GSS_CTXPROBLEM:
2125                         if (!task->tk_cred_retry)
2126                                 break;
2127                         task->tk_cred_retry--;
2128                         dprintk("RPC: %5u %s: retry stale creds\n",
2129                                         task->tk_pid, __func__);
2130                         rpcauth_invalcred(task);
2131                         /* Ensure we obtain a new XID! */
2132                         xprt_release(task);
2133                         task->tk_action = call_reserve;
2134                         goto out_retry;
2135                 case RPC_AUTH_BADCRED:
2136                 case RPC_AUTH_BADVERF:
2137                         /* possibly garbled cred/verf? */
2138                         if (!task->tk_garb_retry)
2139                                 break;
2140                         task->tk_garb_retry--;
2141                         dprintk("RPC: %5u %s: retry garbled creds\n",
2142                                         task->tk_pid, __func__);
2143                         task->tk_action = call_bind;
2144                         goto out_retry;
2145                 case RPC_AUTH_TOOWEAK:
2146                         rcu_read_lock();
2147                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2148                                "authentication.\n",
2149                                rcu_dereference(clnt->cl_xprt)->servername);
2150                         rcu_read_unlock();
2151                         break;
2152                 default:
2153                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2154                                         task->tk_pid, __func__, n);
2155                         error = -EIO;
2156                 }
2157                 dprintk("RPC: %5u %s: call rejected %d\n",
2158                                 task->tk_pid, __func__, n);
2159                 goto out_err;
2160         }
2161         if (!(p = rpcauth_checkverf(task, p))) {
2162                 dprintk("RPC: %5u %s: auth check failed\n",
2163                                 task->tk_pid, __func__);
2164                 goto out_garbage;               /* bad verifier, retry */
2165         }
2166         len = p - (__be32 *)iov->iov_base - 1;
2167         if (len < 0)
2168                 goto out_overflow;
2169         switch ((n = ntohl(*p++))) {
2170         case RPC_SUCCESS:
2171                 return p;
2172         case RPC_PROG_UNAVAIL:
2173                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2174                                 "by server %s\n", task->tk_pid, __func__,
2175                                 (unsigned int)clnt->cl_prog,
2176                                 rcu_dereference(clnt->cl_xprt)->servername);
2177                 error = -EPFNOSUPPORT;
2178                 goto out_err;
2179         case RPC_PROG_MISMATCH:
2180                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2181                                 "by server %s\n", task->tk_pid, __func__,
2182                                 (unsigned int)clnt->cl_prog,
2183                                 (unsigned int)clnt->cl_vers,
2184                                 rcu_dereference(clnt->cl_xprt)->servername);
2185                 error = -EPROTONOSUPPORT;
2186                 goto out_err;
2187         case RPC_PROC_UNAVAIL:
2188                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2189                                 "version %u on server %s\n",
2190                                 task->tk_pid, __func__,
2191                                 rpc_proc_name(task),
2192                                 clnt->cl_prog, clnt->cl_vers,
2193                                 rcu_dereference(clnt->cl_xprt)->servername);
2194                 error = -EOPNOTSUPP;
2195                 goto out_err;
2196         case RPC_GARBAGE_ARGS:
2197                 dprintk("RPC: %5u %s: server saw garbage\n",
2198                                 task->tk_pid, __func__);
2199                 break;                  /* retry */
2200         default:
2201                 dprintk("RPC: %5u %s: server accept status: %x\n",
2202                                 task->tk_pid, __func__, n);
2203                 /* Also retry */
2204         }
2205
2206 out_garbage:
2207         clnt->cl_stats->rpcgarbage++;
2208         if (task->tk_garb_retry) {
2209                 task->tk_garb_retry--;
2210                 dprintk("RPC: %5u %s: retrying\n",
2211                                 task->tk_pid, __func__);
2212                 task->tk_action = call_bind;
2213 out_retry:
2214                 return ERR_PTR(-EAGAIN);
2215         }
2216 out_eio:
2217         error = -EIO;
2218 out_err:
2219         rpc_exit(task, error);
2220         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2221                         __func__, error);
2222         return ERR_PTR(error);
2223 out_overflow:
2224         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2225                         __func__);
2226         goto out_garbage;
2227 }
2228
2229 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2230 {
2231 }
2232
2233 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2234 {
2235         return 0;
2236 }
2237
2238 static struct rpc_procinfo rpcproc_null = {
2239         .p_encode = rpcproc_encode_null,
2240         .p_decode = rpcproc_decode_null,
2241 };
2242
2243 static int rpc_ping(struct rpc_clnt *clnt)
2244 {
2245         struct rpc_message msg = {
2246                 .rpc_proc = &rpcproc_null,
2247         };
2248         int err;
2249         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2250         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2251         put_rpccred(msg.rpc_cred);
2252         return err;
2253 }
2254
2255 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2256 {
2257         struct rpc_message msg = {
2258                 .rpc_proc = &rpcproc_null,
2259                 .rpc_cred = cred,
2260         };
2261         struct rpc_task_setup task_setup_data = {
2262                 .rpc_client = clnt,
2263                 .rpc_message = &msg,
2264                 .callback_ops = &rpc_default_ops,
2265                 .flags = flags,
2266         };
2267         return rpc_run_task(&task_setup_data);
2268 }
2269 EXPORT_SYMBOL_GPL(rpc_call_null);
2270
2271 #ifdef RPC_DEBUG
2272 static void rpc_show_header(void)
2273 {
2274         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2275                 "-timeout ---ops--\n");
2276 }
2277
2278 static void rpc_show_task(const struct rpc_clnt *clnt,
2279                           const struct rpc_task *task)
2280 {
2281         const char *rpc_waitq = "none";
2282
2283         if (RPC_IS_QUEUED(task))
2284                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2285
2286         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2287                 task->tk_pid, task->tk_flags, task->tk_status,
2288                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2289                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2290                 task->tk_action, rpc_waitq);
2291 }
2292
2293 void rpc_show_tasks(struct net *net)
2294 {
2295         struct rpc_clnt *clnt;
2296         struct rpc_task *task;
2297         int header = 0;
2298         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2299
2300         spin_lock(&sn->rpc_client_lock);
2301         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2302                 spin_lock(&clnt->cl_lock);
2303                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2304                         if (!header) {
2305                                 rpc_show_header();
2306                                 header++;
2307                         }
2308                         rpc_show_task(clnt, task);
2309                 }
2310                 spin_unlock(&clnt->cl_lock);
2311         }
2312         spin_unlock(&sn->rpc_client_lock);
2313 }
2314 #endif