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   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  *  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/utsname.h>
  31
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35
  36 #include <linux/nfs.h>
  37
  38
  39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  40
  41 #ifdef RPC_DEBUG
  42 # define RPCDBG_FACILITY        RPCDBG_CALL
  43 #endif
  44
  45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  46
  47
  48 static void     call_start(struct rpc_task *task);
  49 static void     call_reserve(struct rpc_task *task);
  50 static void     call_reserveresult(struct rpc_task *task);
  51 static void     call_allocate(struct rpc_task *task);
  52 static void     call_encode(struct rpc_task *task);
  53 static void     call_decode(struct rpc_task *task);
  54 static void     call_bind(struct rpc_task *task);
  55 static void     call_bind_status(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 synchronous code that
 382  *      sleeps on RPC calls
 383  */
 384 #define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
 385
 386 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 387 {
 388         unsigned long   sigallow = 0;
 389         sigset_t sigmask;
 390
 391         /* Block all signals except those listed in sigallow */
 392         if (intr)
 393                 sigallow |= RPC_INTR_SIGNALS;
 394         siginitsetinv(&sigmask, sigallow);
 395         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 396 }
 397
 398 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 399 {
 400         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 401 }
 402
 403 static inline void rpc_restore_sigmask(sigset_t *oldset)
 404 {
 405         sigprocmask(SIG_SETMASK, oldset, NULL);
 406 }
 407
 408 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 409 {
 410         rpc_save_sigmask(oldset, clnt->cl_intr);
 411 }
 412
 413 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 414 {
 415         rpc_restore_sigmask(oldset);
 416 }
 417
 418 /*
 419  * New rpc_call implementation
 420  */
 421 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 422 {
 423         struct rpc_task *task;
 424         sigset_t        oldset;
 425         int             status;
 426
 427         /* If this client is slain all further I/O fails */
 428         if (clnt->cl_dead)
 429                 return -EIO;
 430
 431         BUG_ON(flags & RPC_TASK_ASYNC);
 432
 433         status = -ENOMEM;
 434         task = rpc_new_task(clnt, NULL, flags);
 435         if (task == NULL)
 436                 goto out;
 437
 438         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 439         rpc_task_sigmask(task, &oldset);
 440
 441         rpc_call_setup(task, msg, 0);
 442
 443         /* Set up the call info struct and execute the task */
 444         if (task->tk_status == 0) {
 445                 status = rpc_execute(task);
 446         } else {
 447                 status = task->tk_status;
 448                 rpc_release_task(task);
 449         }
 450
 451         rpc_restore_sigmask(&oldset);
 452 out:
 453         return status;
 454 }
 455
 456 /*
 457  * New rpc_call implementation
 458  */
 459 int
 460 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 461                rpc_action callback, void *data)
 462 {
 463         struct rpc_task *task;
 464         sigset_t        oldset;
 465         int             status;
 466
 467         /* If this client is slain all further I/O fails */
 468         if (clnt->cl_dead)
 469                 return -EIO;
 470
 471         flags |= RPC_TASK_ASYNC;
 472
 473         /* Create/initialize a new RPC task */
 474         if (!callback)
 475                 callback = rpc_default_callback;
 476         status = -ENOMEM;
 477         if (!(task = rpc_new_task(clnt, callback, flags)))
 478                 goto out;
 479         task->tk_calldata = data;
 480
 481         /* Mask signals on GSS_AUTH upcalls */
 482         rpc_task_sigmask(task, &oldset);
 483
 484         rpc_call_setup(task, msg, 0);
 485
 486         /* Set up the call info struct and execute the task */
 487         status = task->tk_status;
 488         if (status == 0)
 489                 rpc_execute(task);
 490         else
 491                 rpc_release_task(task);
 492
 493         rpc_restore_sigmask(&oldset);
 494 out:
 495         return status;
 496 }
 497
 498
 499 void
 500 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 501 {
 502         task->tk_msg   = *msg;
 503         task->tk_flags |= flags;
 504         /* Bind the user cred */
 505         if (task->tk_msg.rpc_cred != NULL)
 506                 rpcauth_holdcred(task);
 507         else
 508                 rpcauth_bindcred(task);
 509
 510         if (task->tk_status == 0)
 511                 task->tk_action = call_start;
 512         else
 513                 task->tk_action = NULL;
 514 }
 515
 516 void
 517 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 518 {
 519         struct rpc_xprt *xprt = clnt->cl_xprt;
 520
 521         xprt->sndsize = 0;
 522         if (sndsize)
 523                 xprt->sndsize = sndsize + RPC_SLACK_SPACE;
 524         xprt->rcvsize = 0;
 525         if (rcvsize)
 526                 xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
 527         xprt->ops->set_buffer_size(xprt);
 528 }
 529
 530 /*
 531  * Return size of largest payload RPC client can support, in bytes
 532  *
 533  * For stream transports, this is one RPC record fragment (see RFC
 534  * 1831), as we don't support multi-record requests yet.  For datagram
 535  * transports, this is the size of an IP packet minus the IP, UDP, and
 536  * RPC header sizes.
 537  */
 538 size_t rpc_max_payload(struct rpc_clnt *clnt)
 539 {
 540         return clnt->cl_xprt->max_payload;
 541 }
 542 EXPORT_SYMBOL(rpc_max_payload);
 543
 544 /*
 545  * Restart an (async) RPC call. Usually called from within the
 546  * exit handler.
 547  */
 548 void
 549 rpc_restart_call(struct rpc_task *task)
 550 {
 551         if (RPC_ASSASSINATED(task))
 552                 return;
 553
 554         task->tk_action = call_start;
 555 }
 556
 557 /*
 558  * 0.  Initial state
 559  *
 560  *     Other FSM states can be visited zero or more times, but
 561  *     this state is visited exactly once for each RPC.
 562  */
 563 static void
 564 call_start(struct rpc_task *task)
 565 {
 566         struct rpc_clnt *clnt = task->tk_client;
 567
 568         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 569                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 570                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 571
 572         /* Increment call count */
 573         task->tk_msg.rpc_proc->p_count++;
 574         clnt->cl_stats->rpccnt++;
 575         task->tk_action = call_reserve;
 576 }
 577
 578 /*
 579  * 1.   Reserve an RPC call slot
 580  */
 581 static void
 582 call_reserve(struct rpc_task *task)
 583 {
 584         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 585
 586         if (!rpcauth_uptodatecred(task)) {
 587                 task->tk_action = call_refresh;
 588                 return;
 589         }
 590
 591         task->tk_status  = 0;
 592         task->tk_action  = call_reserveresult;
 593         xprt_reserve(task);
 594 }
 595
 596 /*
 597  * 1b.  Grok the result of xprt_reserve()
 598  */
 599 static void
 600 call_reserveresult(struct rpc_task *task)
 601 {
 602         int status = task->tk_status;
 603
 604         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 605                                 task->tk_pid, task->tk_status);
 606
 607         /*
 608          * After a call to xprt_reserve(), we must have either
 609          * a request slot or else an error status.
 610          */
 611         task->tk_status = 0;
 612         if (status >= 0) {
 613                 if (task->tk_rqstp) {
 614                         task->tk_action = call_allocate;
 615                         return;
 616                 }
 617
 618                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 619                                 __FUNCTION__, status);
 620                 rpc_exit(task, -EIO);
 621                 return;
 622         }
 623
 624         /*
 625          * Even though there was an error, we may have acquired
 626          * a request slot somehow.  Make sure not to leak it.
 627          */
 628         if (task->tk_rqstp) {
 629                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 630                                 __FUNCTION__, status);
 631                 xprt_release(task);
 632         }
 633
 634         switch (status) {
 635         case -EAGAIN:   /* woken up; retry */
 636                 task->tk_action = call_reserve;
 637                 return;
 638         case -EIO:      /* probably a shutdown */
 639                 break;
 640         default:
 641                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 642                                 __FUNCTION__, status);
 643                 break;
 644         }
 645         rpc_exit(task, status);
 646 }
 647
 648 /*
 649  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 650  *      (Note: buffer memory is freed in rpc_task_release).
 651  */
 652 static void
 653 call_allocate(struct rpc_task *task)
 654 {
 655         unsigned int    bufsiz;
 656
 657         dprintk("RPC: %4d call_allocate (status %d)\n",
 658                                 task->tk_pid, task->tk_status);
 659         task->tk_action = call_bind;
 660         if (task->tk_buffer)
 661                 return;
 662
 663         /* FIXME: compute buffer requirements more exactly using
 664          * auth->au_wslack */
 665         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 666
 667         if (rpc_malloc(task, bufsiz << 1) != NULL)
 668                 return;
 669         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 670
 671         if (RPC_IS_ASYNC(task) || !signalled()) {
 672                 xprt_release(task);
 673                 task->tk_action = call_reserve;
 674                 rpc_delay(task, HZ>>4);
 675                 return;
 676         }
 677
 678         rpc_exit(task, -ERESTARTSYS);
 679 }
 680
 681 /*
 682  * 3.   Encode arguments of an RPC call
 683  */
 684 static void
 685 call_encode(struct rpc_task *task)
 686 {
 687         struct rpc_clnt *clnt = task->tk_client;
 688         struct rpc_rqst *req = task->tk_rqstp;
 689         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 690         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 691         unsigned int    bufsiz;
 692         kxdrproc_t      encode;
 693         int             status;
 694         u32             *p;
 695
 696         dprintk("RPC: %4d call_encode (status %d)\n",
 697                                 task->tk_pid, task->tk_status);
 698
 699         /* Default buffer setup */
 700         bufsiz = task->tk_bufsize >> 1;
 701         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 702         sndbuf->head[0].iov_len  = bufsiz;
 703         sndbuf->tail[0].iov_len  = 0;
 704         sndbuf->page_len         = 0;
 705         sndbuf->len              = 0;
 706         sndbuf->buflen           = bufsiz;
 707         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 708         rcvbuf->head[0].iov_len  = bufsiz;
 709         rcvbuf->tail[0].iov_len  = 0;
 710         rcvbuf->page_len         = 0;
 711         rcvbuf->len              = 0;
 712         rcvbuf->buflen           = bufsiz;
 713
 714         /* Encode header and provided arguments */
 715         encode = task->tk_msg.rpc_proc->p_encode;
 716         if (!(p = call_header(task))) {
 717                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 718                 rpc_exit(task, -EIO);
 719                 return;
 720         }
 721         if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
 722                                                  task->tk_msg.rpc_argp)) < 0) {
 723                 printk(KERN_WARNING "%s: can't encode arguments: %d\n",
 724                                 clnt->cl_protname, -status);
 725                 rpc_exit(task, status);
 726         }
 727 }
 728
 729 /*
 730  * 4.   Get the server port number if not yet set
 731  */
 732 static void
 733 call_bind(struct rpc_task *task)
 734 {
 735         struct rpc_clnt *clnt = task->tk_client;
 736
 737         dprintk("RPC: %4d call_bind (status %d)\n",
 738                                 task->tk_pid, task->tk_status);
 739
 740         task->tk_action = call_connect;
 741         if (!clnt->cl_port) {
 742                 task->tk_action = call_bind_status;
 743                 task->tk_timeout = RPC_CONNECT_TIMEOUT;
 744                 rpc_getport(task, clnt);
 745         }
 746 }
 747
 748 /*
 749  * 4a.  Sort out bind result
 750  */
 751 static void
 752 call_bind_status(struct rpc_task *task)
 753 {
 754         int status = -EACCES;
 755
 756         if (task->tk_status >= 0) {
 757                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 758                                         task->tk_pid, task->tk_status);
 759                 task->tk_status = 0;
 760                 task->tk_action = call_connect;
 761                 return;
 762         }
 763
 764         switch (task->tk_status) {
 765         case -EACCES:
 766                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 767                                 task->tk_pid);
 768                 break;
 769         case -ETIMEDOUT:
 770                 dprintk("RPC: %4d rpcbind request timed out\n",
 771                                 task->tk_pid);
 772                 if (RPC_IS_SOFT(task)) {
 773                         status = -EIO;
 774                         break;
 775                 }
 776                 goto retry_bind;
 777         case -EPFNOSUPPORT:
 778                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 779                                 task->tk_pid);
 780                 break;
 781         case -EPROTONOSUPPORT:
 782                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 783                                 task->tk_pid);
 784                 break;
 785         default:
 786                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 787                                 task->tk_pid, -task->tk_status);
 788                 status = -EIO;
 789                 break;
 790         }
 791
 792         rpc_exit(task, status);
 793         return;
 794
 795 retry_bind:
 796         task->tk_status = 0;
 797         task->tk_action = call_bind;
 798         return;
 799 }
 800
 801 /*
 802  * 4b.  Connect to the RPC server
 803  */
 804 static void
 805 call_connect(struct rpc_task *task)
 806 {
 807         struct rpc_xprt *xprt = task->tk_xprt;
 808
 809         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 810                         task->tk_pid, xprt,
 811                         (xprt_connected(xprt) ? "is" : "is not"));
 812
 813         task->tk_action = call_transmit;
 814         if (!xprt_connected(xprt)) {
 815                 task->tk_action = call_connect_status;
 816                 if (task->tk_status < 0)
 817                         return;
 818                 xprt_connect(task);
 819         }
 820 }
 821
 822 /*
 823  * 4c.  Sort out connect result
 824  */
 825 static void
 826 call_connect_status(struct rpc_task *task)
 827 {
 828         struct rpc_clnt *clnt = task->tk_client;
 829         int status = task->tk_status;
 830
 831         dprintk("RPC: %5u call_connect_status (status %d)\n",
 832                                 task->tk_pid, task->tk_status);
 833
 834         task->tk_status = 0;
 835         if (status >= 0) {
 836                 clnt->cl_stats->netreconn++;
 837                 task->tk_action = call_transmit;
 838                 return;
 839         }
 840
 841         /* Something failed: remote service port may have changed */
 842         if (clnt->cl_autobind)
 843                 clnt->cl_port = 0;
 844
 845         switch (status) {
 846         case -ENOTCONN:
 847         case -ETIMEDOUT:
 848         case -EAGAIN:
 849                 task->tk_action = call_bind;
 850                 break;
 851         default:
 852                 rpc_exit(task, -EIO);
 853                 break;
 854         }
 855 }
 856
 857 /*
 858  * 5.   Transmit the RPC request, and wait for reply
 859  */
 860 static void
 861 call_transmit(struct rpc_task *task)
 862 {
 863         dprintk("RPC: %4d call_transmit (status %d)\n",
 864                                 task->tk_pid, task->tk_status);
 865
 866         task->tk_action = call_status;
 867         if (task->tk_status < 0)
 868                 return;
 869         task->tk_status = xprt_prepare_transmit(task);
 870         if (task->tk_status != 0)
 871                 return;
 872         /* Encode here so that rpcsec_gss can use correct sequence number. */
 873         if (!task->tk_rqstp->rq_bytes_sent)
 874                 call_encode(task);
 875         if (task->tk_status < 0)
 876                 return;
 877         xprt_transmit(task);
 878         if (task->tk_status < 0)
 879                 return;
 880         if (!task->tk_msg.rpc_proc->p_decode) {
 881                 task->tk_action = NULL;
 882                 rpc_wake_up_task(task);
 883         }
 884 }
 885
 886 /*
 887  * 6.   Sort out the RPC call status
 888  */
 889 static void
 890 call_status(struct rpc_task *task)
 891 {
 892         struct rpc_clnt *clnt = task->tk_client;
 893         struct rpc_rqst *req = task->tk_rqstp;
 894         int             status;
 895
 896         if (req->rq_received > 0 && !req->rq_bytes_sent)
 897                 task->tk_status = req->rq_received;
 898
 899         dprintk("RPC: %4d call_status (status %d)\n",
 900                                 task->tk_pid, task->tk_status);
 901
 902         status = task->tk_status;
 903         if (status >= 0) {
 904                 task->tk_action = call_decode;
 905                 return;
 906         }
 907
 908         task->tk_status = 0;
 909         switch(status) {
 910         case -ETIMEDOUT:
 911                 task->tk_action = call_timeout;
 912                 break;
 913         case -ECONNREFUSED:
 914         case -ENOTCONN:
 915                 req->rq_bytes_sent = 0;
 916                 if (clnt->cl_autobind)
 917                         clnt->cl_port = 0;
 918                 task->tk_action = call_bind;
 919                 break;
 920         case -EAGAIN:
 921                 task->tk_action = call_transmit;
 922                 break;
 923         case -EIO:
 924                 /* shutdown or soft timeout */
 925                 rpc_exit(task, status);
 926                 break;
 927         default:
 928                 if (clnt->cl_chatty)
 929                         printk("%s: RPC call returned error %d\n",
 930                                clnt->cl_protname, -status);
 931                 rpc_exit(task, status);
 932                 break;
 933         }
 934 }
 935
 936 /*
 937  * 6a.  Handle RPC timeout
 938  *      We do not release the request slot, so we keep using the
 939  *      same XID for all retransmits.
 940  */
 941 static void
 942 call_timeout(struct rpc_task *task)
 943 {
 944         struct rpc_clnt *clnt = task->tk_client;
 945
 946         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 947                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 948                 goto retry;
 949         }
 950
 951         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 952         if (RPC_IS_SOFT(task)) {
 953                 if (clnt->cl_chatty)
 954                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 955                                 clnt->cl_protname, clnt->cl_server);
 956                 rpc_exit(task, -EIO);
 957                 return;
 958         }
 959
 960         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 961                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 962                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 963                         clnt->cl_protname, clnt->cl_server);
 964         }
 965         if (clnt->cl_autobind)
 966                 clnt->cl_port = 0;
 967
 968 retry:
 969         clnt->cl_stats->rpcretrans++;
 970         task->tk_action = call_bind;
 971         task->tk_status = 0;
 972 }
 973
 974 /*
 975  * 7.   Decode the RPC reply
 976  */
 977 static void
 978 call_decode(struct rpc_task *task)
 979 {
 980         struct rpc_clnt *clnt = task->tk_client;
 981         struct rpc_rqst *req = task->tk_rqstp;
 982         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
 983         u32             *p;
 984
 985         dprintk("RPC: %4d call_decode (status %d)\n",
 986                                 task->tk_pid, task->tk_status);
 987
 988         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
 989                 printk(KERN_NOTICE "%s: server %s OK\n",
 990                         clnt->cl_protname, clnt->cl_server);
 991                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
 992         }
 993
 994         if (task->tk_status < 12) {
 995                 if (!RPC_IS_SOFT(task)) {
 996                         task->tk_action = call_bind;
 997                         clnt->cl_stats->rpcretrans++;
 998                         goto out_retry;
 999                 }
1000                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1001                         clnt->cl_protname, task->tk_status);
1002                 rpc_exit(task, -EIO);
1003                 return;
1004         }
1005
1006         req->rq_rcv_buf.len = req->rq_private_buf.len;
1007
1008         /* Check that the softirq receive buffer is valid */
1009         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1010                                 sizeof(req->rq_rcv_buf)) != 0);
1011
1012         /* Verify the RPC header */
1013         if (!(p = call_verify(task))) {
1014                 if (task->tk_action == NULL)
1015                         return;
1016                 goto out_retry;
1017         }
1018
1019         task->tk_action = NULL;
1020
1021         if (decode)
1022                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1023                                                       task->tk_msg.rpc_resp);
1024         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1025                                         task->tk_status);
1026         return;
1027 out_retry:
1028         req->rq_received = req->rq_private_buf.len = 0;
1029         task->tk_status = 0;
1030 }
1031
1032 /*
1033  * 8.   Refresh the credentials if rejected by the server
1034  */
1035 static void
1036 call_refresh(struct rpc_task *task)
1037 {
1038         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1039
1040         xprt_release(task);     /* Must do to obtain new XID */
1041         task->tk_action = call_refreshresult;
1042         task->tk_status = 0;
1043         task->tk_client->cl_stats->rpcauthrefresh++;
1044         rpcauth_refreshcred(task);
1045 }
1046
1047 /*
1048  * 8a.  Process the results of a credential refresh
1049  */
1050 static void
1051 call_refreshresult(struct rpc_task *task)
1052 {
1053         int status = task->tk_status;
1054         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1055                                 task->tk_pid, task->tk_status);
1056
1057         task->tk_status = 0;
1058         task->tk_action = call_reserve;
1059         if (status >= 0 && rpcauth_uptodatecred(task))
1060                 return;
1061         if (status == -EACCES) {
1062                 rpc_exit(task, -EACCES);
1063                 return;
1064         }
1065         task->tk_action = call_refresh;
1066         if (status != -ETIMEDOUT)
1067                 rpc_delay(task, 3*HZ);
1068         return;
1069 }
1070
1071 /*
1072  * Call header serialization
1073  */
1074 static u32 *
1075 call_header(struct rpc_task *task)
1076 {
1077         struct rpc_clnt *clnt = task->tk_client;
1078         struct rpc_rqst *req = task->tk_rqstp;
1079         u32             *p = req->rq_svec[0].iov_base;
1080
1081         /* FIXME: check buffer size? */
1082
1083         p = xprt_skip_transport_header(task->tk_xprt, p);
1084         *p++ = req->rq_xid;             /* XID */
1085         *p++ = htonl(RPC_CALL);         /* CALL */
1086         *p++ = htonl(RPC_VERSION);      /* RPC version */
1087         *p++ = htonl(clnt->cl_prog);    /* program number */
1088         *p++ = htonl(clnt->cl_vers);    /* program version */
1089         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1090         p = rpcauth_marshcred(task, p);
1091         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1092         return p;
1093 }
1094
1095 /*
1096  * Reply header verification
1097  */
1098 static u32 *
1099 call_verify(struct rpc_task *task)
1100 {
1101         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1102         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1103         u32     *p = iov->iov_base, n;
1104         int error = -EACCES;
1105
1106         if ((len -= 3) < 0)
1107                 goto out_overflow;
1108         p += 1; /* skip XID */
1109
1110         if ((n = ntohl(*p++)) != RPC_REPLY) {
1111                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1112                 goto out_retry;
1113         }
1114         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1115                 if (--len < 0)
1116                         goto out_overflow;
1117                 switch ((n = ntohl(*p++))) {
1118                         case RPC_AUTH_ERROR:
1119                                 break;
1120                         case RPC_MISMATCH:
1121                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1122                                 error = -EPROTONOSUPPORT;
1123                                 goto out_err;
1124                         default:
1125                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1126                                 goto out_eio;
1127                 }
1128                 if (--len < 0)
1129                         goto out_overflow;
1130                 switch ((n = ntohl(*p++))) {
1131                 case RPC_AUTH_REJECTEDCRED:
1132                 case RPC_AUTH_REJECTEDVERF:
1133                 case RPCSEC_GSS_CREDPROBLEM:
1134                 case RPCSEC_GSS_CTXPROBLEM:
1135                         if (!task->tk_cred_retry)
1136                                 break;
1137                         task->tk_cred_retry--;
1138                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1139                                                         task->tk_pid);
1140                         rpcauth_invalcred(task);
1141                         task->tk_action = call_refresh;
1142                         return NULL;
1143                 case RPC_AUTH_BADCRED:
1144                 case RPC_AUTH_BADVERF:
1145                         /* possibly garbled cred/verf? */
1146                         if (!task->tk_garb_retry)
1147                                 break;
1148                         task->tk_garb_retry--;
1149                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1150                                                         task->tk_pid);
1151                         task->tk_action = call_bind;
1152                         return NULL;
1153                 case RPC_AUTH_TOOWEAK:
1154                         printk(KERN_NOTICE "call_verify: server requires stronger "
1155                                "authentication.\n");
1156                         break;
1157                 default:
1158                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1159                         error = -EIO;
1160                 }
1161                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1162                                                 task->tk_pid, n);
1163                 goto out_err;
1164         }
1165         if (!(p = rpcauth_checkverf(task, p))) {
1166                 printk(KERN_WARNING "call_verify: auth check failed\n");
1167                 goto out_retry;         /* bad verifier, retry */
1168         }
1169         len = p - (u32 *)iov->iov_base - 1;
1170         if (len < 0)
1171                 goto out_overflow;
1172         switch ((n = ntohl(*p++))) {
1173         case RPC_SUCCESS:
1174                 return p;
1175         case RPC_PROG_UNAVAIL:
1176                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1177                                 (unsigned int)task->tk_client->cl_prog,
1178                                 task->tk_client->cl_server);
1179                 error = -EPFNOSUPPORT;
1180                 goto out_err;
1181         case RPC_PROG_MISMATCH:
1182                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1183                                 (unsigned int)task->tk_client->cl_prog,
1184                                 (unsigned int)task->tk_client->cl_vers,
1185                                 task->tk_client->cl_server);
1186                 error = -EPROTONOSUPPORT;
1187                 goto out_err;
1188         case RPC_PROC_UNAVAIL:
1189                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1190                                 task->tk_msg.rpc_proc,
1191                                 task->tk_client->cl_prog,
1192                                 task->tk_client->cl_vers,
1193                                 task->tk_client->cl_server);
1194                 error = -EOPNOTSUPP;
1195                 goto out_err;
1196         case RPC_GARBAGE_ARGS:
1197                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1198                 break;                  /* retry */
1199         default:
1200                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1201                 /* Also retry */
1202         }
1203
1204 out_retry:
1205         task->tk_client->cl_stats->rpcgarbage++;
1206         if (task->tk_garb_retry) {
1207                 task->tk_garb_retry--;
1208                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1209                 task->tk_action = call_bind;
1210                 return NULL;
1211         }
1212         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1213 out_eio:
1214         error = -EIO;
1215 out_err:
1216         rpc_exit(task, error);
1217         return NULL;
1218 out_overflow:
1219         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1220         goto out_retry;
1221 }
1222
1223 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1224 {
1225         return 0;
1226 }
1227
1228 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1229 {
1230         return 0;
1231 }
1232
1233 static struct rpc_procinfo rpcproc_null = {
1234         .p_encode = rpcproc_encode_null,
1235         .p_decode = rpcproc_decode_null,
1236 };
1237
1238 int rpc_ping(struct rpc_clnt *clnt, int flags)
1239 {
1240         struct rpc_message msg = {
1241                 .rpc_proc = &rpcproc_null,
1242         };
1243         int err;
1244         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1245         err = rpc_call_sync(clnt, &msg, flags);
1246         put_rpccred(msg.rpc_cred);
1247         return err;
1248 }