err.no Git - linux-2.6/blob - net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/rpcclnt.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  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/in.h>
  31 #include <linux/utsname.h>
  32
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36
  37 #include <linux/nfs.h>
  38
  39
  40 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  41
  42 #ifdef RPC_DEBUG
  43 # define RPCDBG_FACILITY        RPCDBG_CALL
  44 #endif
  45
  46 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  47
  48
  49 static void     call_start(struct rpc_task *task);
  50 static void     call_reserve(struct rpc_task *task);
  51 static void     call_reserveresult(struct rpc_task *task);
  52 static void     call_allocate(struct rpc_task *task);
  53 static void     call_encode(struct rpc_task *task);
  54 static void     call_decode(struct rpc_task *task);
  55 static void     call_bind(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_refresh(struct rpc_task *task);
  59 static void     call_refreshresult(struct rpc_task *task);
  60 static void     call_timeout(struct rpc_task *task);
  61 static void     call_connect(struct rpc_task *task);
  62 static void     call_connect_status(struct rpc_task *task);
  63 static u32 *    call_header(struct rpc_task *task);
  64 static u32 *    call_verify(struct rpc_task *task);
  65
  66
  67 static int
  68 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  69 {
  70         static uint32_t clntid;
  71         int error;
  72
  73         if (dir_name == NULL)
  74                 return 0;
  75         for (;;) {
  76                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  77                                 "%s/clnt%x", dir_name,
  78                                 (unsigned int)clntid++);
  79                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  80                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  81                 if (!IS_ERR(clnt->cl_dentry))
  82                         return 0;
  83                 error = PTR_ERR(clnt->cl_dentry);
  84                 if (error != -EEXIST) {
  85                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  86                                         clnt->cl_pathname, error);
  87                         return error;
  88                 }
  89         }
  90 }
  91
  92 /*
  93  * Create an RPC client
  94  * FIXME: This should also take a flags argument (as in task->tk_flags).
  95  * It's called (among others) from pmap_create_client, which may in
  96  * turn be called by an async task. In this case, rpciod should not be
  97  * made to sleep too long.
  98  */
  99 struct rpc_clnt *
 100 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 101                   struct rpc_program *program, u32 vers,
 102                   rpc_authflavor_t flavor)
 103 {
 104         struct rpc_version      *version;
 105         struct rpc_clnt         *clnt = NULL;
 106         struct rpc_auth         *auth;
 107         int err;
 108         int len;
 109
 110         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 111                 program->name, servname, xprt);
 112
 113         err = -EINVAL;
 114         if (!xprt)
 115                 goto out_err;
 116         if (vers >= program->nrvers || !(version = program->version[vers]))
 117                 goto out_err;
 118
 119         err = -ENOMEM;
 120         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 121         if (!clnt)
 122                 goto out_err;
 123         memset(clnt, 0, sizeof(*clnt));
 124         atomic_set(&clnt->cl_users, 0);
 125         atomic_set(&clnt->cl_count, 1);
 126         clnt->cl_parent = clnt;
 127
 128         clnt->cl_server = clnt->cl_inline_name;
 129         len = strlen(servname) + 1;
 130         if (len > sizeof(clnt->cl_inline_name)) {
 131                 char *buf = kmalloc(len, GFP_KERNEL);
 132                 if (buf != 0)
 133                         clnt->cl_server = buf;
 134                 else
 135                         len = sizeof(clnt->cl_inline_name);
 136         }
 137         strlcpy(clnt->cl_server, servname, len);
 138
 139         clnt->cl_xprt     = xprt;
 140         clnt->cl_procinfo = version->procs;
 141         clnt->cl_maxproc  = version->nrprocs;
 142         clnt->cl_protname = program->name;
 143         clnt->cl_pmap     = &clnt->cl_pmap_default;
 144         clnt->cl_port     = xprt->addr.sin_port;
 145         clnt->cl_prog     = program->number;
 146         clnt->cl_vers     = version->number;
 147         clnt->cl_prot     = xprt->prot;
 148         clnt->cl_stats    = program->stats;
 149         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 150
 151         if (!clnt->cl_port)
 152                 clnt->cl_autobind = 1;
 153
 154         clnt->cl_rtt = &clnt->cl_rtt_default;
 155         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 156
 157         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 158         if (err < 0)
 159                 goto out_no_path;
 160
 161         auth = rpcauth_create(flavor, clnt);
 162         if (IS_ERR(auth)) {
 163                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 164                                 flavor);
 165                 err = PTR_ERR(auth);
 166                 goto out_no_auth;
 167         }
 168
 169         /* save the nodename */
 170         clnt->cl_nodelen = strlen(system_utsname.nodename);
 171         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 172                 clnt->cl_nodelen = UNX_MAXNODENAME;
 173         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 174         return clnt;
 175
 176 out_no_auth:
 177         rpc_rmdir(clnt->cl_pathname);
 178 out_no_path:
 179         if (clnt->cl_server != clnt->cl_inline_name)
 180                 kfree(clnt->cl_server);
 181         kfree(clnt);
 182 out_err:
 183         xprt_destroy(xprt);
 184         return ERR_PTR(err);
 185 }
 186
 187 /**
 188  * Create an RPC client
 189  * @xprt - pointer to xprt struct
 190  * @servname - name of server
 191  * @info - rpc_program
 192  * @version - rpc_program version
 193  * @authflavor - rpc_auth flavour to use
 194  *
 195  * Creates an RPC client structure, then pings the server in order to
 196  * determine if it is up, and if it supports this program and version.
 197  *
 198  * This function should never be called by asynchronous tasks such as
 199  * the portmapper.
 200  */
 201 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 202                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 203 {
 204         struct rpc_clnt *clnt;
 205         int err;
 206
 207         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 208         if (IS_ERR(clnt))
 209                 return clnt;
 210         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 211         if (err == 0)
 212                 return clnt;
 213         rpc_shutdown_client(clnt);
 214         return ERR_PTR(err);
 215 }
 216
 217 /*
 218  * This function clones the RPC client structure. It allows us to share the
 219  * same transport while varying parameters such as the authentication
 220  * flavour.
 221  */
 222 struct rpc_clnt *
 223 rpc_clone_client(struct rpc_clnt *clnt)
 224 {
 225         struct rpc_clnt *new;
 226
 227         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
 228         if (!new)
 229                 goto out_no_clnt;
 230         memcpy(new, clnt, sizeof(*new));
 231         atomic_set(&new->cl_count, 1);
 232         atomic_set(&new->cl_users, 0);
 233         new->cl_parent = clnt;
 234         atomic_inc(&clnt->cl_count);
 235         /* Duplicate portmapper */
 236         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 237         /* Turn off autobind on clones */
 238         new->cl_autobind = 0;
 239         new->cl_oneshot = 0;
 240         new->cl_dead = 0;
 241         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 242         if (new->cl_auth)
 243                 atomic_inc(&new->cl_auth->au_count);
 244         new->cl_pmap            = &new->cl_pmap_default;
 245         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 246         return new;
 247 out_no_clnt:
 248         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 249         return ERR_PTR(-ENOMEM);
 250 }
 251
 252 /*
 253  * Properly shut down an RPC client, terminating all outstanding
 254  * requests. Note that we must be certain that cl_oneshot and
 255  * cl_dead are cleared, or else the client would be destroyed
 256  * when the last task releases it.
 257  */
 258 int
 259 rpc_shutdown_client(struct rpc_clnt *clnt)
 260 {
 261         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 262                         clnt->cl_protname, clnt->cl_server,
 263                         atomic_read(&clnt->cl_users));
 264
 265         while (atomic_read(&clnt->cl_users) > 0) {
 266                 /* Don't let rpc_release_client destroy us */
 267                 clnt->cl_oneshot = 0;
 268                 clnt->cl_dead = 0;
 269                 rpc_killall_tasks(clnt);
 270                 sleep_on_timeout(&destroy_wait, 1*HZ);
 271         }
 272
 273         if (atomic_read(&clnt->cl_users) < 0) {
 274                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 275                                 clnt, atomic_read(&clnt->cl_users));
 276 #ifdef RPC_DEBUG
 277                 rpc_show_tasks();
 278 #endif
 279                 BUG();
 280         }
 281
 282         return rpc_destroy_client(clnt);
 283 }
 284
 285 /*
 286  * Delete an RPC client
 287  */
 288 int
 289 rpc_destroy_client(struct rpc_clnt *clnt)
 290 {
 291         if (!atomic_dec_and_test(&clnt->cl_count))
 292                 return 1;
 293         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 294
 295         dprintk("RPC: destroying %s client for %s\n",
 296                         clnt->cl_protname, clnt->cl_server);
 297         if (clnt->cl_auth) {
 298                 rpcauth_destroy(clnt->cl_auth);
 299                 clnt->cl_auth = NULL;
 300         }
 301         if (clnt->cl_parent != clnt) {
 302                 rpc_destroy_client(clnt->cl_parent);
 303                 goto out_free;
 304         }
 305         if (clnt->cl_pathname[0])
 306                 rpc_rmdir(clnt->cl_pathname);
 307         if (clnt->cl_xprt) {
 308                 xprt_destroy(clnt->cl_xprt);
 309                 clnt->cl_xprt = NULL;
 310         }
 311         if (clnt->cl_server != clnt->cl_inline_name)
 312                 kfree(clnt->cl_server);
 313 out_free:
 314         kfree(clnt);
 315         return 0;
 316 }
 317
 318 /*
 319  * Release an RPC client
 320  */
 321 void
 322 rpc_release_client(struct rpc_clnt *clnt)
 323 {
 324         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 325                                 clnt, atomic_read(&clnt->cl_users));
 326
 327         if (!atomic_dec_and_test(&clnt->cl_users))
 328                 return;
 329         wake_up(&destroy_wait);
 330         if (clnt->cl_oneshot || clnt->cl_dead)
 331                 rpc_destroy_client(clnt);
 332 }
 333
 334 /**
 335  * rpc_bind_new_program - bind a new RPC program to an existing client
 336  * @old - old rpc_client
 337  * @program - rpc program to set
 338  * @vers - rpc program version
 339  *
 340  * Clones the rpc client and sets up a new RPC program. This is mainly
 341  * of use for enabling different RPC programs to share the same transport.
 342  * The Sun NFSv2/v3 ACL protocol can do this.
 343  */
 344 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 345                                       struct rpc_program *program,
 346                                       int vers)
 347 {
 348         struct rpc_clnt *clnt;
 349         struct rpc_version *version;
 350         int err;
 351
 352         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 353         version = program->version[vers];
 354         clnt = rpc_clone_client(old);
 355         if (IS_ERR(clnt))
 356                 goto out;
 357         clnt->cl_procinfo = version->procs;
 358         clnt->cl_maxproc  = version->nrprocs;
 359         clnt->cl_protname = program->name;
 360         clnt->cl_prog     = program->number;
 361         clnt->cl_vers     = version->number;
 362         clnt->cl_stats    = program->stats;
 363         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 364         if (err != 0) {
 365                 rpc_shutdown_client(clnt);
 366                 clnt = ERR_PTR(err);
 367         }
 368 out:
 369         return clnt;
 370 }
 371
 372 /*
 373  * Default callback for async RPC calls
 374  */
 375 static void
 376 rpc_default_callback(struct rpc_task *task)
 377 {
 378 }
 379
 380 /*
 381  *      Export the signal mask handling for aysnchronous code that
 382  *      sleeps on RPC calls
 383  */
 384
 385 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 386 {
 387         unsigned long   sigallow = sigmask(SIGKILL);
 388         unsigned long   irqflags;
 389
 390         /* Turn off various signals */
 391         if (clnt->cl_intr) {
 392                 struct k_sigaction *action = current->sighand->action;
 393                 if (action[SIGINT-1].sa.sa_handler == SIG_DFL)
 394                         sigallow |= sigmask(SIGINT);
 395                 if (action[SIGQUIT-1].sa.sa_handler == SIG_DFL)
 396                         sigallow |= sigmask(SIGQUIT);
 397         }
 398         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 399         *oldset = current->blocked;
 400         siginitsetinv(&current->blocked, sigallow & ~oldset->sig[0]);
 401         recalc_sigpending();
 402         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 403 }
 404
 405 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 406 {
 407         unsigned long   irqflags;
 408
 409         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 410         current->blocked = *oldset;
 411         recalc_sigpending();
 412         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 413 }
 414
 415 /*
 416  * New rpc_call implementation
 417  */
 418 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 419 {
 420         struct rpc_task *task;
 421         sigset_t        oldset;
 422         int             status;
 423
 424         /* If this client is slain all further I/O fails */
 425         if (clnt->cl_dead)
 426                 return -EIO;
 427
 428         BUG_ON(flags & RPC_TASK_ASYNC);
 429
 430         rpc_clnt_sigmask(clnt, &oldset);
 431
 432         status = -ENOMEM;
 433         task = rpc_new_task(clnt, NULL, flags);
 434         if (task == NULL)
 435                 goto out;
 436
 437         rpc_call_setup(task, msg, 0);
 438
 439         /* Set up the call info struct and execute the task */
 440         if (task->tk_status == 0)
 441                 status = rpc_execute(task);
 442         else {
 443                 status = task->tk_status;
 444                 rpc_release_task(task);
 445         }
 446
 447 out:
 448         rpc_clnt_sigunmask(clnt, &oldset);
 449
 450         return status;
 451 }
 452
 453 /*
 454  * New rpc_call implementation
 455  */
 456 int
 457 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 458                rpc_action callback, void *data)
 459 {
 460         struct rpc_task *task;
 461         sigset_t        oldset;
 462         int             status;
 463
 464         /* If this client is slain all further I/O fails */
 465         if (clnt->cl_dead)
 466                 return -EIO;
 467
 468         flags |= RPC_TASK_ASYNC;
 469
 470         rpc_clnt_sigmask(clnt, &oldset);
 471
 472         /* Create/initialize a new RPC task */
 473         if (!callback)
 474                 callback = rpc_default_callback;
 475         status = -ENOMEM;
 476         if (!(task = rpc_new_task(clnt, callback, flags)))
 477                 goto out;
 478         task->tk_calldata = data;
 479
 480         rpc_call_setup(task, msg, 0);
 481
 482         /* Set up the call info struct and execute the task */
 483         status = task->tk_status;
 484         if (status == 0)
 485                 rpc_execute(task);
 486         else
 487                 rpc_release_task(task);
 488
 489 out:
 490         rpc_clnt_sigunmask(clnt, &oldset);
 491
 492         return status;
 493 }
 494
 495
 496 void
 497 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 498 {
 499         task->tk_msg   = *msg;
 500         task->tk_flags |= flags;
 501         /* Bind the user cred */
 502         if (task->tk_msg.rpc_cred != NULL)
 503                 rpcauth_holdcred(task);
 504         else
 505                 rpcauth_bindcred(task);
 506
 507         if (task->tk_status == 0)
 508                 task->tk_action = call_start;
 509         else
 510                 task->tk_action = NULL;
 511 }
 512
 513 void
 514 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 515 {
 516         struct rpc_xprt *xprt = clnt->cl_xprt;
 517
 518         xprt->sndsize = 0;
 519         if (sndsize)
 520                 xprt->sndsize = sndsize + RPC_SLACK_SPACE;
 521         xprt->rcvsize = 0;
 522         if (rcvsize)
 523                 xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
 524         if (xprt_connected(xprt))
 525                 xprt_sock_setbufsize(xprt);
 526 }
 527
 528 /*
 529  * Return size of largest payload RPC client can support, in bytes
 530  *
 531  * For stream transports, this is one RPC record fragment (see RFC
 532  * 1831), as we don't support multi-record requests yet.  For datagram
 533  * transports, this is the size of an IP packet minus the IP, UDP, and
 534  * RPC header sizes.
 535  */
 536 size_t rpc_max_payload(struct rpc_clnt *clnt)
 537 {
 538         return clnt->cl_xprt->max_payload;
 539 }
 540 EXPORT_SYMBOL(rpc_max_payload);
 541
 542 /*
 543  * Restart an (async) RPC call. Usually called from within the
 544  * exit handler.
 545  */
 546 void
 547 rpc_restart_call(struct rpc_task *task)
 548 {
 549         if (RPC_ASSASSINATED(task))
 550                 return;
 551
 552         task->tk_action = call_start;
 553 }
 554
 555 /*
 556  * 0.  Initial state
 557  *
 558  *     Other FSM states can be visited zero or more times, but
 559  *     this state is visited exactly once for each RPC.
 560  */
 561 static void
 562 call_start(struct rpc_task *task)
 563 {
 564         struct rpc_clnt *clnt = task->tk_client;
 565
 566         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 567                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 568                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 569
 570         /* Increment call count */
 571         task->tk_msg.rpc_proc->p_count++;
 572         clnt->cl_stats->rpccnt++;
 573         task->tk_action = call_reserve;
 574 }
 575
 576 /*
 577  * 1.   Reserve an RPC call slot
 578  */
 579 static void
 580 call_reserve(struct rpc_task *task)
 581 {
 582         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 583
 584         if (!rpcauth_uptodatecred(task)) {
 585                 task->tk_action = call_refresh;
 586                 return;
 587         }
 588
 589         task->tk_status  = 0;
 590         task->tk_action  = call_reserveresult;
 591         xprt_reserve(task);
 592 }
 593
 594 /*
 595  * 1b.  Grok the result of xprt_reserve()
 596  */
 597 static void
 598 call_reserveresult(struct rpc_task *task)
 599 {
 600         int status = task->tk_status;
 601
 602         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 603                                 task->tk_pid, task->tk_status);
 604
 605         /*
 606          * After a call to xprt_reserve(), we must have either
 607          * a request slot or else an error status.
 608          */
 609         task->tk_status = 0;
 610         if (status >= 0) {
 611                 if (task->tk_rqstp) {
 612                         task->tk_action = call_allocate;
 613                         return;
 614                 }
 615
 616                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 617                                 __FUNCTION__, status);
 618                 rpc_exit(task, -EIO);
 619                 return;
 620         }
 621
 622         /*
 623          * Even though there was an error, we may have acquired
 624          * a request slot somehow.  Make sure not to leak it.
 625          */
 626         if (task->tk_rqstp) {
 627                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 628                                 __FUNCTION__, status);
 629                 xprt_release(task);
 630         }
 631
 632         switch (status) {
 633         case -EAGAIN:   /* woken up; retry */
 634                 task->tk_action = call_reserve;
 635                 return;
 636         case -EIO:      /* probably a shutdown */
 637                 break;
 638         default:
 639                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 640                                 __FUNCTION__, status);
 641                 break;
 642         }
 643         rpc_exit(task, status);
 644 }
 645
 646 /*
 647  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 648  *      (Note: buffer memory is freed in rpc_task_release).
 649  */
 650 static void
 651 call_allocate(struct rpc_task *task)
 652 {
 653         unsigned int    bufsiz;
 654
 655         dprintk("RPC: %4d call_allocate (status %d)\n",
 656                                 task->tk_pid, task->tk_status);
 657         task->tk_action = call_bind;
 658         if (task->tk_buffer)
 659                 return;
 660
 661         /* FIXME: compute buffer requirements more exactly using
 662          * auth->au_wslack */
 663         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 664
 665         if (rpc_malloc(task, bufsiz << 1) != NULL)
 666                 return;
 667         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 668
 669         if (RPC_IS_ASYNC(task) || !(task->tk_client->cl_intr && signalled())) {
 670                 xprt_release(task);
 671                 task->tk_action = call_reserve;
 672                 rpc_delay(task, HZ>>4);
 673                 return;
 674         }
 675
 676         rpc_exit(task, -ERESTARTSYS);
 677 }
 678
 679 /*
 680  * 3.   Encode arguments of an RPC call
 681  */
 682 static void
 683 call_encode(struct rpc_task *task)
 684 {
 685         struct rpc_clnt *clnt = task->tk_client;
 686         struct rpc_rqst *req = task->tk_rqstp;
 687         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 688         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 689         unsigned int    bufsiz;
 690         kxdrproc_t      encode;
 691         int             status;
 692         u32             *p;
 693
 694         dprintk("RPC: %4d call_encode (status %d)\n",
 695                                 task->tk_pid, task->tk_status);
 696
 697         /* Default buffer setup */
 698         bufsiz = task->tk_bufsize >> 1;
 699         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 700         sndbuf->head[0].iov_len  = bufsiz;
 701         sndbuf->tail[0].iov_len  = 0;
 702         sndbuf->page_len         = 0;
 703         sndbuf->len              = 0;
 704         sndbuf->buflen           = bufsiz;
 705         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 706         rcvbuf->head[0].iov_len  = bufsiz;
 707         rcvbuf->tail[0].iov_len  = 0;
 708         rcvbuf->page_len         = 0;
 709         rcvbuf->len              = 0;
 710         rcvbuf->buflen           = bufsiz;
 711
 712         /* Encode header and provided arguments */
 713         encode = task->tk_msg.rpc_proc->p_encode;
 714         if (!(p = call_header(task))) {
 715                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 716                 rpc_exit(task, -EIO);
 717                 return;
 718         }
 719         if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
 720                                                  task->tk_msg.rpc_argp)) < 0) {
 721                 printk(KERN_WARNING "%s: can't encode arguments: %d\n",
 722                                 clnt->cl_protname, -status);
 723                 rpc_exit(task, status);
 724         }
 725 }
 726
 727 /*
 728  * 4.   Get the server port number if not yet set
 729  */
 730 static void
 731 call_bind(struct rpc_task *task)
 732 {
 733         struct rpc_clnt *clnt = task->tk_client;
 734         struct rpc_xprt *xprt = clnt->cl_xprt;
 735
 736         dprintk("RPC: %4d call_bind xprt %p %s connected\n", task->tk_pid,
 737                         xprt, (xprt_connected(xprt) ? "is" : "is not"));
 738
 739         task->tk_action = (xprt_connected(xprt)) ? call_transmit : call_connect;
 740
 741         if (!clnt->cl_port) {
 742                 task->tk_action = call_connect;
 743                 task->tk_timeout = RPC_CONNECT_TIMEOUT;
 744                 rpc_getport(task, clnt);
 745         }
 746 }
 747
 748 /*
 749  * 4a.  Connect to the RPC server (TCP case)
 750  */
 751 static void
 752 call_connect(struct rpc_task *task)
 753 {
 754         struct rpc_clnt *clnt = task->tk_client;
 755
 756         dprintk("RPC: %4d call_connect status %d\n",
 757                                 task->tk_pid, task->tk_status);
 758
 759         if (xprt_connected(clnt->cl_xprt)) {
 760                 task->tk_action = call_transmit;
 761                 return;
 762         }
 763         task->tk_action = call_connect_status;
 764         if (task->tk_status < 0)
 765                 return;
 766         xprt_connect(task);
 767 }
 768
 769 /*
 770  * 4b. Sort out connect result
 771  */
 772 static void
 773 call_connect_status(struct rpc_task *task)
 774 {
 775         struct rpc_clnt *clnt = task->tk_client;
 776         int status = task->tk_status;
 777
 778         task->tk_status = 0;
 779         if (status >= 0) {
 780                 clnt->cl_stats->netreconn++;
 781                 task->tk_action = call_transmit;
 782                 return;
 783         }
 784
 785         /* Something failed: we may have to rebind */
 786         if (clnt->cl_autobind)
 787                 clnt->cl_port = 0;
 788         switch (status) {
 789         case -ENOTCONN:
 790         case -ETIMEDOUT:
 791         case -EAGAIN:
 792                 task->tk_action = (clnt->cl_port == 0) ? call_bind : call_connect;
 793                 break;
 794         default:
 795                 rpc_exit(task, -EIO);
 796         }
 797 }
 798
 799 /*
 800  * 5.   Transmit the RPC request, and wait for reply
 801  */
 802 static void
 803 call_transmit(struct rpc_task *task)
 804 {
 805         dprintk("RPC: %4d call_transmit (status %d)\n",
 806                                 task->tk_pid, task->tk_status);
 807
 808         task->tk_action = call_status;
 809         if (task->tk_status < 0)
 810                 return;
 811         task->tk_status = xprt_prepare_transmit(task);
 812         if (task->tk_status != 0)
 813                 return;
 814         /* Encode here so that rpcsec_gss can use correct sequence number. */
 815         if (!task->tk_rqstp->rq_bytes_sent)
 816                 call_encode(task);
 817         if (task->tk_status < 0)
 818                 return;
 819         xprt_transmit(task);
 820         if (task->tk_status < 0)
 821                 return;
 822         if (!task->tk_msg.rpc_proc->p_decode) {
 823                 task->tk_action = NULL;
 824                 rpc_wake_up_task(task);
 825         }
 826 }
 827
 828 /*
 829  * 6.   Sort out the RPC call status
 830  */
 831 static void
 832 call_status(struct rpc_task *task)
 833 {
 834         struct rpc_clnt *clnt = task->tk_client;
 835         struct rpc_rqst *req = task->tk_rqstp;
 836         int             status;
 837
 838         if (req->rq_received > 0 && !req->rq_bytes_sent)
 839                 task->tk_status = req->rq_received;
 840
 841         dprintk("RPC: %4d call_status (status %d)\n",
 842                                 task->tk_pid, task->tk_status);
 843
 844         status = task->tk_status;
 845         if (status >= 0) {
 846                 task->tk_action = call_decode;
 847                 return;
 848         }
 849
 850         task->tk_status = 0;
 851         switch(status) {
 852         case -ETIMEDOUT:
 853                 task->tk_action = call_timeout;
 854                 break;
 855         case -ECONNREFUSED:
 856         case -ENOTCONN:
 857                 req->rq_bytes_sent = 0;
 858                 if (clnt->cl_autobind)
 859                         clnt->cl_port = 0;
 860                 task->tk_action = call_bind;
 861                 break;
 862         case -EAGAIN:
 863                 task->tk_action = call_transmit;
 864                 break;
 865         case -EIO:
 866                 /* shutdown or soft timeout */
 867                 rpc_exit(task, status);
 868                 break;
 869         default:
 870                 if (clnt->cl_chatty)
 871                         printk("%s: RPC call returned error %d\n",
 872                                clnt->cl_protname, -status);
 873                 rpc_exit(task, status);
 874                 break;
 875         }
 876 }
 877
 878 /*
 879  * 6a.  Handle RPC timeout
 880  *      We do not release the request slot, so we keep using the
 881  *      same XID for all retransmits.
 882  */
 883 static void
 884 call_timeout(struct rpc_task *task)
 885 {
 886         struct rpc_clnt *clnt = task->tk_client;
 887
 888         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 889                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 890                 goto retry;
 891         }
 892
 893         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 894         if (RPC_IS_SOFT(task)) {
 895                 if (clnt->cl_chatty)
 896                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 897                                 clnt->cl_protname, clnt->cl_server);
 898                 rpc_exit(task, -EIO);
 899                 return;
 900         }
 901
 902         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 903                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 904                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 905                         clnt->cl_protname, clnt->cl_server);
 906         }
 907         if (clnt->cl_autobind)
 908                 clnt->cl_port = 0;
 909
 910 retry:
 911         clnt->cl_stats->rpcretrans++;
 912         task->tk_action = call_bind;
 913         task->tk_status = 0;
 914 }
 915
 916 /*
 917  * 7.   Decode the RPC reply
 918  */
 919 static void
 920 call_decode(struct rpc_task *task)
 921 {
 922         struct rpc_clnt *clnt = task->tk_client;
 923         struct rpc_rqst *req = task->tk_rqstp;
 924         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
 925         u32             *p;
 926
 927         dprintk("RPC: %4d call_decode (status %d)\n",
 928                                 task->tk_pid, task->tk_status);
 929
 930         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
 931                 printk(KERN_NOTICE "%s: server %s OK\n",
 932                         clnt->cl_protname, clnt->cl_server);
 933                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
 934         }
 935
 936         if (task->tk_status < 12) {
 937                 if (!RPC_IS_SOFT(task)) {
 938                         task->tk_action = call_bind;
 939                         clnt->cl_stats->rpcretrans++;
 940                         goto out_retry;
 941                 }
 942                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
 943                         clnt->cl_protname, task->tk_status);
 944                 rpc_exit(task, -EIO);
 945                 return;
 946         }
 947
 948         req->rq_rcv_buf.len = req->rq_private_buf.len;
 949
 950         /* Check that the softirq receive buffer is valid */
 951         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
 952                                 sizeof(req->rq_rcv_buf)) != 0);
 953
 954         /* Verify the RPC header */
 955         if (!(p = call_verify(task))) {
 956                 if (task->tk_action == NULL)
 957                         return;
 958                 goto out_retry;
 959         }
 960
 961         task->tk_action = NULL;
 962
 963         if (decode)
 964                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
 965                                                       task->tk_msg.rpc_resp);
 966         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
 967                                         task->tk_status);
 968         return;
 969 out_retry:
 970         req->rq_received = req->rq_private_buf.len = 0;
 971         task->tk_status = 0;
 972 }
 973
 974 /*
 975  * 8.   Refresh the credentials if rejected by the server
 976  */
 977 static void
 978 call_refresh(struct rpc_task *task)
 979 {
 980         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
 981
 982         xprt_release(task);     /* Must do to obtain new XID */
 983         task->tk_action = call_refreshresult;
 984         task->tk_status = 0;
 985         task->tk_client->cl_stats->rpcauthrefresh++;
 986         rpcauth_refreshcred(task);
 987 }
 988
 989 /*
 990  * 8a.  Process the results of a credential refresh
 991  */
 992 static void
 993 call_refreshresult(struct rpc_task *task)
 994 {
 995         int status = task->tk_status;
 996         dprintk("RPC: %4d call_refreshresult (status %d)\n",
 997                                 task->tk_pid, task->tk_status);
 998
 999         task->tk_status = 0;
1000         task->tk_action = call_reserve;
1001         if (status >= 0 && rpcauth_uptodatecred(task))
1002                 return;
1003         if (status == -EACCES) {
1004                 rpc_exit(task, -EACCES);
1005                 return;
1006         }
1007         task->tk_action = call_refresh;
1008         if (status != -ETIMEDOUT)
1009                 rpc_delay(task, 3*HZ);
1010         return;
1011 }
1012
1013 /*
1014  * Call header serialization
1015  */
1016 static u32 *
1017 call_header(struct rpc_task *task)
1018 {
1019         struct rpc_clnt *clnt = task->tk_client;
1020         struct rpc_xprt *xprt = clnt->cl_xprt;
1021         struct rpc_rqst *req = task->tk_rqstp;
1022         u32             *p = req->rq_svec[0].iov_base;
1023
1024         /* FIXME: check buffer size? */
1025         if (xprt->stream)
1026                 *p++ = 0;               /* fill in later */
1027         *p++ = req->rq_xid;             /* XID */
1028         *p++ = htonl(RPC_CALL);         /* CALL */
1029         *p++ = htonl(RPC_VERSION);      /* RPC version */
1030         *p++ = htonl(clnt->cl_prog);    /* program number */
1031         *p++ = htonl(clnt->cl_vers);    /* program version */
1032         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1033         p = rpcauth_marshcred(task, p);
1034         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1035         return p;
1036 }
1037
1038 /*
1039  * Reply header verification
1040  */
1041 static u32 *
1042 call_verify(struct rpc_task *task)
1043 {
1044         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1045         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1046         u32     *p = iov->iov_base, n;
1047         int error = -EACCES;
1048
1049         if ((len -= 3) < 0)
1050                 goto out_overflow;
1051         p += 1; /* skip XID */
1052
1053         if ((n = ntohl(*p++)) != RPC_REPLY) {
1054                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1055                 goto out_retry;
1056         }
1057         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1058                 if (--len < 0)
1059                         goto out_overflow;
1060                 switch ((n = ntohl(*p++))) {
1061                         case RPC_AUTH_ERROR:
1062                                 break;
1063                         case RPC_MISMATCH:
1064                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1065                                 error = -EPROTONOSUPPORT;
1066                                 goto out_err;
1067                         default:
1068                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1069                                 goto out_eio;
1070                 }
1071                 if (--len < 0)
1072                         goto out_overflow;
1073                 switch ((n = ntohl(*p++))) {
1074                 case RPC_AUTH_REJECTEDCRED:
1075                 case RPC_AUTH_REJECTEDVERF:
1076                 case RPCSEC_GSS_CREDPROBLEM:
1077                 case RPCSEC_GSS_CTXPROBLEM:
1078                         if (!task->tk_cred_retry)
1079                                 break;
1080                         task->tk_cred_retry--;
1081                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1082                                                         task->tk_pid);
1083                         rpcauth_invalcred(task);
1084                         task->tk_action = call_refresh;
1085                         return NULL;
1086                 case RPC_AUTH_BADCRED:
1087                 case RPC_AUTH_BADVERF:
1088                         /* possibly garbled cred/verf? */
1089                         if (!task->tk_garb_retry)
1090                                 break;
1091                         task->tk_garb_retry--;
1092                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1093                                                         task->tk_pid);
1094                         task->tk_action = call_bind;
1095                         return NULL;
1096                 case RPC_AUTH_TOOWEAK:
1097                         printk(KERN_NOTICE "call_verify: server requires stronger "
1098                                "authentication.\n");
1099                         break;
1100                 default:
1101                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1102                         error = -EIO;
1103                 }
1104                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1105                                                 task->tk_pid, n);
1106                 goto out_err;
1107         }
1108         if (!(p = rpcauth_checkverf(task, p))) {
1109                 printk(KERN_WARNING "call_verify: auth check failed\n");
1110                 goto out_retry;         /* bad verifier, retry */
1111         }
1112         len = p - (u32 *)iov->iov_base - 1;
1113         if (len < 0)
1114                 goto out_overflow;
1115         switch ((n = ntohl(*p++))) {
1116         case RPC_SUCCESS:
1117                 return p;
1118         case RPC_PROG_UNAVAIL:
1119                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1120                                 (unsigned int)task->tk_client->cl_prog,
1121                                 task->tk_client->cl_server);
1122                 error = -EPFNOSUPPORT;
1123                 goto out_err;
1124         case RPC_PROG_MISMATCH:
1125                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1126                                 (unsigned int)task->tk_client->cl_prog,
1127                                 (unsigned int)task->tk_client->cl_vers,
1128                                 task->tk_client->cl_server);
1129                 error = -EPROTONOSUPPORT;
1130                 goto out_err;
1131         case RPC_PROC_UNAVAIL:
1132                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1133                                 task->tk_msg.rpc_proc,
1134                                 task->tk_client->cl_prog,
1135                                 task->tk_client->cl_vers,
1136                                 task->tk_client->cl_server);
1137                 error = -EOPNOTSUPP;
1138                 goto out_err;
1139         case RPC_GARBAGE_ARGS:
1140                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1141                 break;                  /* retry */
1142         default:
1143                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1144                 /* Also retry */
1145         }
1146
1147 out_retry:
1148         task->tk_client->cl_stats->rpcgarbage++;
1149         if (task->tk_garb_retry) {
1150                 task->tk_garb_retry--;
1151                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1152                 task->tk_action = call_bind;
1153                 return NULL;
1154         }
1155         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1156 out_eio:
1157         error = -EIO;
1158 out_err:
1159         rpc_exit(task, error);
1160         return NULL;
1161 out_overflow:
1162         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1163         goto out_retry;
1164 }
1165
1166 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1167 {
1168         return 0;
1169 }
1170
1171 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1172 {
1173         return 0;
1174 }
1175
1176 static struct rpc_procinfo rpcproc_null = {
1177         .p_encode = rpcproc_encode_null,
1178         .p_decode = rpcproc_decode_null,
1179 };
1180
1181 int rpc_ping(struct rpc_clnt *clnt, int flags)
1182 {
1183         struct rpc_message msg = {
1184                 .rpc_proc = &rpcproc_null,
1185         };
1186         int err;
1187         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1188         err = rpc_call_sync(clnt, &msg, flags);
1189         put_rpccred(msg.rpc_cred);
1190         return err;
1191 }