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