Pileus Git - ~andy/linux/blob - 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  *  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_transmit_status(struct rpc_task *task);
  59 static void     call_refresh(struct rpc_task *task);
  60 static void     call_refreshresult(struct rpc_task *task);
  61 static void     call_timeout(struct rpc_task *task);
  62 static void     call_connect(struct rpc_task *task);
  63 static void     call_connect_status(struct rpc_task *task);
  64 static u32 *    call_header(struct rpc_task *task);
  65 static u32 *    call_verify(struct rpc_task *task);
  66
  67
  68 static int
  69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  70 {
  71         static uint32_t clntid;
  72         int error;
  73
  74         if (dir_name == NULL)
  75                 return 0;
  76         for (;;) {
  77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  78                                 "%s/clnt%x", dir_name,
  79                                 (unsigned int)clntid++);
  80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  82                 if (!IS_ERR(clnt->cl_dentry))
  83                         return 0;
  84                 error = PTR_ERR(clnt->cl_dentry);
  85                 if (error != -EEXIST) {
  86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  87                                         clnt->cl_pathname, error);
  88                         return error;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Create an RPC client
  95  * FIXME: This should also take a flags argument (as in task->tk_flags).
  96  * It's called (among others) from pmap_create_client, which may in
  97  * turn be called by an async task. In this case, rpciod should not be
  98  * made to sleep too long.
  99  */
 100 struct rpc_clnt *
 101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 102                   struct rpc_program *program, u32 vers,
 103                   rpc_authflavor_t flavor)
 104 {
 105         struct rpc_version      *version;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct rpc_auth         *auth;
 108         int err;
 109         int len;
 110
 111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 112                 program->name, servname, xprt);
 113
 114         err = -EINVAL;
 115         if (!xprt)
 116                 goto out_err;
 117         if (vers >= program->nrvers || !(version = program->version[vers]))
 118                 goto out_err;
 119
 120         err = -ENOMEM;
 121         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 122         if (!clnt)
 123                 goto out_err;
 124         memset(clnt, 0, sizeof(*clnt));
 125         atomic_set(&clnt->cl_users, 0);
 126         atomic_set(&clnt->cl_count, 1);
 127         clnt->cl_parent = clnt;
 128
 129         clnt->cl_server = clnt->cl_inline_name;
 130         len = strlen(servname) + 1;
 131         if (len > sizeof(clnt->cl_inline_name)) {
 132                 char *buf = kmalloc(len, GFP_KERNEL);
 133                 if (buf != 0)
 134                         clnt->cl_server = buf;
 135                 else
 136                         len = sizeof(clnt->cl_inline_name);
 137         }
 138         strlcpy(clnt->cl_server, servname, len);
 139
 140         clnt->cl_xprt     = xprt;
 141         clnt->cl_procinfo = version->procs;
 142         clnt->cl_maxproc  = version->nrprocs;
 143         clnt->cl_protname = program->name;
 144         clnt->cl_pmap     = &clnt->cl_pmap_default;
 145         clnt->cl_port     = xprt->addr.sin_port;
 146         clnt->cl_prog     = program->number;
 147         clnt->cl_vers     = version->number;
 148         clnt->cl_prot     = xprt->prot;
 149         clnt->cl_stats    = program->stats;
 150         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 151
 152         if (!clnt->cl_port)
 153                 clnt->cl_autobind = 1;
 154
 155         clnt->cl_rtt = &clnt->cl_rtt_default;
 156         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 157
 158         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 159         if (err < 0)
 160                 goto out_no_path;
 161
 162         auth = rpcauth_create(flavor, clnt);
 163         if (IS_ERR(auth)) {
 164                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 165                                 flavor);
 166                 err = PTR_ERR(auth);
 167                 goto out_no_auth;
 168         }
 169
 170         /* save the nodename */
 171         clnt->cl_nodelen = strlen(system_utsname.nodename);
 172         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 173                 clnt->cl_nodelen = UNX_MAXNODENAME;
 174         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 175         return clnt;
 176
 177 out_no_auth:
 178         rpc_rmdir(clnt->cl_pathname);
 179 out_no_path:
 180         if (clnt->cl_server != clnt->cl_inline_name)
 181                 kfree(clnt->cl_server);
 182         kfree(clnt);
 183 out_err:
 184         xprt_destroy(xprt);
 185         return ERR_PTR(err);
 186 }
 187
 188 /**
 189  * Create an RPC client
 190  * @xprt - pointer to xprt struct
 191  * @servname - name of server
 192  * @info - rpc_program
 193  * @version - rpc_program version
 194  * @authflavor - rpc_auth flavour to use
 195  *
 196  * Creates an RPC client structure, then pings the server in order to
 197  * determine if it is up, and if it supports this program and version.
 198  *
 199  * This function should never be called by asynchronous tasks such as
 200  * the portmapper.
 201  */
 202 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 203                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 204 {
 205         struct rpc_clnt *clnt;
 206         int err;
 207
 208         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 209         if (IS_ERR(clnt))
 210                 return clnt;
 211         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 212         if (err == 0)
 213                 return clnt;
 214         rpc_shutdown_client(clnt);
 215         return ERR_PTR(err);
 216 }
 217
 218 /*
 219  * This function clones the RPC client structure. It allows us to share the
 220  * same transport while varying parameters such as the authentication
 221  * flavour.
 222  */
 223 struct rpc_clnt *
 224 rpc_clone_client(struct rpc_clnt *clnt)
 225 {
 226         struct rpc_clnt *new;
 227
 228         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
 229         if (!new)
 230                 goto out_no_clnt;
 231         memcpy(new, clnt, sizeof(*new));
 232         atomic_set(&new->cl_count, 1);
 233         atomic_set(&new->cl_users, 0);
 234         new->cl_parent = clnt;
 235         atomic_inc(&clnt->cl_count);
 236         /* Duplicate portmapper */
 237         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 238         /* Turn off autobind on clones */
 239         new->cl_autobind = 0;
 240         new->cl_oneshot = 0;
 241         new->cl_dead = 0;
 242         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 243         if (new->cl_auth)
 244                 atomic_inc(&new->cl_auth->au_count);
 245         new->cl_pmap            = &new->cl_pmap_default;
 246         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 247         return new;
 248 out_no_clnt:
 249         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 250         return ERR_PTR(-ENOMEM);
 251 }
 252
 253 /*
 254  * Properly shut down an RPC client, terminating all outstanding
 255  * requests. Note that we must be certain that cl_oneshot and
 256  * cl_dead are cleared, or else the client would be destroyed
 257  * when the last task releases it.
 258  */
 259 int
 260 rpc_shutdown_client(struct rpc_clnt *clnt)
 261 {
 262         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 263                         clnt->cl_protname, clnt->cl_server,
 264                         atomic_read(&clnt->cl_users));
 265
 266         while (atomic_read(&clnt->cl_users) > 0) {
 267                 /* Don't let rpc_release_client destroy us */
 268                 clnt->cl_oneshot = 0;
 269                 clnt->cl_dead = 0;
 270                 rpc_killall_tasks(clnt);
 271                 sleep_on_timeout(&destroy_wait, 1*HZ);
 272         }
 273
 274         if (atomic_read(&clnt->cl_users) < 0) {
 275                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 276                                 clnt, atomic_read(&clnt->cl_users));
 277 #ifdef RPC_DEBUG
 278                 rpc_show_tasks();
 279 #endif
 280                 BUG();
 281         }
 282
 283         return rpc_destroy_client(clnt);
 284 }
 285
 286 /*
 287  * Delete an RPC client
 288  */
 289 int
 290 rpc_destroy_client(struct rpc_clnt *clnt)
 291 {
 292         if (!atomic_dec_and_test(&clnt->cl_count))
 293                 return 1;
 294         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 295
 296         dprintk("RPC: destroying %s client for %s\n",
 297                         clnt->cl_protname, clnt->cl_server);
 298         if (clnt->cl_auth) {
 299                 rpcauth_destroy(clnt->cl_auth);
 300                 clnt->cl_auth = NULL;
 301         }
 302         if (clnt->cl_parent != clnt) {
 303                 rpc_destroy_client(clnt->cl_parent);
 304                 goto out_free;
 305         }
 306         if (clnt->cl_pathname[0])
 307                 rpc_rmdir(clnt->cl_pathname);
 308         if (clnt->cl_xprt) {
 309                 xprt_destroy(clnt->cl_xprt);
 310                 clnt->cl_xprt = NULL;
 311         }
 312         if (clnt->cl_server != clnt->cl_inline_name)
 313                 kfree(clnt->cl_server);
 314 out_free:
 315         kfree(clnt);
 316         return 0;
 317 }
 318
 319 /*
 320  * Release an RPC client
 321  */
 322 void
 323 rpc_release_client(struct rpc_clnt *clnt)
 324 {
 325         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 326                                 clnt, atomic_read(&clnt->cl_users));
 327
 328         if (!atomic_dec_and_test(&clnt->cl_users))
 329                 return;
 330         wake_up(&destroy_wait);
 331         if (clnt->cl_oneshot || clnt->cl_dead)
 332                 rpc_destroy_client(clnt);
 333 }
 334
 335 /**
 336  * rpc_bind_new_program - bind a new RPC program to an existing client
 337  * @old - old rpc_client
 338  * @program - rpc program to set
 339  * @vers - rpc program version
 340  *
 341  * Clones the rpc client and sets up a new RPC program. This is mainly
 342  * of use for enabling different RPC programs to share the same transport.
 343  * The Sun NFSv2/v3 ACL protocol can do this.
 344  */
 345 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 346                                       struct rpc_program *program,
 347                                       int vers)
 348 {
 349         struct rpc_clnt *clnt;
 350         struct rpc_version *version;
 351         int err;
 352
 353         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 354         version = program->version[vers];
 355         clnt = rpc_clone_client(old);
 356         if (IS_ERR(clnt))
 357                 goto out;
 358         clnt->cl_procinfo = version->procs;
 359         clnt->cl_maxproc  = version->nrprocs;
 360         clnt->cl_protname = program->name;
 361         clnt->cl_prog     = program->number;
 362         clnt->cl_vers     = version->number;
 363         clnt->cl_stats    = program->stats;
 364         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 365         if (err != 0) {
 366                 rpc_shutdown_client(clnt);
 367                 clnt = ERR_PTR(err);
 368         }
 369 out:
 370         return clnt;
 371 }
 372
 373 /*
 374  * Default callback for async RPC calls
 375  */
 376 static void
 377 rpc_default_callback(struct rpc_task *task, void *data)
 378 {
 379 }
 380
 381 static const struct rpc_call_ops rpc_default_ops = {
 382         .rpc_call_done = rpc_default_callback,
 383 };
 384
 385 /*
 386  *      Export the signal mask handling for synchronous code that
 387  *      sleeps on RPC calls
 388  */
 389 #define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
 390
 391 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 392 {
 393         unsigned long   sigallow = 0;
 394         sigset_t sigmask;
 395
 396         /* Block all signals except those listed in sigallow */
 397         if (intr)
 398                 sigallow |= RPC_INTR_SIGNALS;
 399         siginitsetinv(&sigmask, sigallow);
 400         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 401 }
 402
 403 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 404 {
 405         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 406 }
 407
 408 static inline void rpc_restore_sigmask(sigset_t *oldset)
 409 {
 410         sigprocmask(SIG_SETMASK, oldset, NULL);
 411 }
 412
 413 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 414 {
 415         rpc_save_sigmask(oldset, clnt->cl_intr);
 416 }
 417
 418 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 419 {
 420         rpc_restore_sigmask(oldset);
 421 }
 422
 423 /*
 424  * New rpc_call implementation
 425  */
 426 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 427 {
 428         struct rpc_task *task;
 429         sigset_t        oldset;
 430         int             status;
 431
 432         /* If this client is slain all further I/O fails */
 433         if (clnt->cl_dead)
 434                 return -EIO;
 435
 436         BUG_ON(flags & RPC_TASK_ASYNC);
 437
 438         status = -ENOMEM;
 439         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 440         if (task == NULL)
 441                 goto out;
 442
 443         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 444         rpc_task_sigmask(task, &oldset);
 445
 446         rpc_call_setup(task, msg, 0);
 447
 448         /* Set up the call info struct and execute the task */
 449         if (task->tk_status == 0) {
 450                 status = rpc_execute(task);
 451         } else {
 452                 status = task->tk_status;
 453                 rpc_release_task(task);
 454         }
 455
 456         rpc_restore_sigmask(&oldset);
 457 out:
 458         return status;
 459 }
 460
 461 /*
 462  * New rpc_call implementation
 463  */
 464 int
 465 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 466                const struct rpc_call_ops *tk_ops, void *data)
 467 {
 468         struct rpc_task *task;
 469         sigset_t        oldset;
 470         int             status;
 471
 472         /* If this client is slain all further I/O fails */
 473         if (clnt->cl_dead)
 474                 return -EIO;
 475
 476         flags |= RPC_TASK_ASYNC;
 477
 478         /* Create/initialize a new RPC task */
 479         status = -ENOMEM;
 480         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 481                 goto out;
 482
 483         /* Mask signals on GSS_AUTH upcalls */
 484         rpc_task_sigmask(task, &oldset);
 485
 486         rpc_call_setup(task, msg, 0);
 487
 488         /* Set up the call info struct and execute the task */
 489         status = task->tk_status;
 490         if (status == 0)
 491                 rpc_execute(task);
 492         else
 493                 rpc_release_task(task);
 494
 495         rpc_restore_sigmask(&oldset);
 496 out:
 497         return status;
 498 }
 499
 500
 501 void
 502 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 503 {
 504         task->tk_msg   = *msg;
 505         task->tk_flags |= flags;
 506         /* Bind the user cred */
 507         if (task->tk_msg.rpc_cred != NULL)
 508                 rpcauth_holdcred(task);
 509         else
 510                 rpcauth_bindcred(task);
 511
 512         if (task->tk_status == 0)
 513                 task->tk_action = call_start;
 514         else
 515                 task->tk_action = rpc_exit_task;
 516 }
 517
 518 void
 519 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 520 {
 521         struct rpc_xprt *xprt = clnt->cl_xprt;
 522         if (xprt->ops->set_buffer_size)
 523                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 524 }
 525
 526 /*
 527  * Return size of largest payload RPC client can support, in bytes
 528  *
 529  * For stream transports, this is one RPC record fragment (see RFC
 530  * 1831), as we don't support multi-record requests yet.  For datagram
 531  * transports, this is the size of an IP packet minus the IP, UDP, and
 532  * RPC header sizes.
 533  */
 534 size_t rpc_max_payload(struct rpc_clnt *clnt)
 535 {
 536         return clnt->cl_xprt->max_payload;
 537 }
 538 EXPORT_SYMBOL(rpc_max_payload);
 539
 540 /*
 541  * Restart an (async) RPC call. Usually called from within the
 542  * exit handler.
 543  */
 544 void
 545 rpc_restart_call(struct rpc_task *task)
 546 {
 547         if (RPC_ASSASSINATED(task))
 548                 return;
 549
 550         task->tk_action = call_start;
 551 }
 552
 553 /*
 554  * 0.  Initial state
 555  *
 556  *     Other FSM states can be visited zero or more times, but
 557  *     this state is visited exactly once for each RPC.
 558  */
 559 static void
 560 call_start(struct rpc_task *task)
 561 {
 562         struct rpc_clnt *clnt = task->tk_client;
 563
 564         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 565                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 566                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 567
 568         /* Increment call count */
 569         task->tk_msg.rpc_proc->p_count++;
 570         clnt->cl_stats->rpccnt++;
 571         task->tk_action = call_reserve;
 572 }
 573
 574 /*
 575  * 1.   Reserve an RPC call slot
 576  */
 577 static void
 578 call_reserve(struct rpc_task *task)
 579 {
 580         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 581
 582         if (!rpcauth_uptodatecred(task)) {
 583                 task->tk_action = call_refresh;
 584                 return;
 585         }
 586
 587         task->tk_status  = 0;
 588         task->tk_action  = call_reserveresult;
 589         xprt_reserve(task);
 590 }
 591
 592 /*
 593  * 1b.  Grok the result of xprt_reserve()
 594  */
 595 static void
 596 call_reserveresult(struct rpc_task *task)
 597 {
 598         int status = task->tk_status;
 599
 600         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 601                                 task->tk_pid, task->tk_status);
 602
 603         /*
 604          * After a call to xprt_reserve(), we must have either
 605          * a request slot or else an error status.
 606          */
 607         task->tk_status = 0;
 608         if (status >= 0) {
 609                 if (task->tk_rqstp) {
 610                         task->tk_action = call_allocate;
 611                         return;
 612                 }
 613
 614                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 615                                 __FUNCTION__, status);
 616                 rpc_exit(task, -EIO);
 617                 return;
 618         }
 619
 620         /*
 621          * Even though there was an error, we may have acquired
 622          * a request slot somehow.  Make sure not to leak it.
 623          */
 624         if (task->tk_rqstp) {
 625                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 626                                 __FUNCTION__, status);
 627                 xprt_release(task);
 628         }
 629
 630         switch (status) {
 631         case -EAGAIN:   /* woken up; retry */
 632                 task->tk_action = call_reserve;
 633                 return;
 634         case -EIO:      /* probably a shutdown */
 635                 break;
 636         default:
 637                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 638                                 __FUNCTION__, status);
 639                 break;
 640         }
 641         rpc_exit(task, status);
 642 }
 643
 644 /*
 645  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 646  *      (Note: buffer memory is freed in rpc_task_release).
 647  */
 648 static void
 649 call_allocate(struct rpc_task *task)
 650 {
 651         unsigned int    bufsiz;
 652
 653         dprintk("RPC: %4d call_allocate (status %d)\n",
 654                                 task->tk_pid, task->tk_status);
 655         task->tk_action = call_bind;
 656         if (task->tk_buffer)
 657                 return;
 658
 659         /* FIXME: compute buffer requirements more exactly using
 660          * auth->au_wslack */
 661         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 662
 663         if (rpc_malloc(task, bufsiz << 1) != NULL)
 664                 return;
 665         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 666
 667         if (RPC_IS_ASYNC(task) || !signalled()) {
 668                 xprt_release(task);
 669                 task->tk_action = call_reserve;
 670                 rpc_delay(task, HZ>>4);
 671                 return;
 672         }
 673
 674         rpc_exit(task, -ERESTARTSYS);
 675 }
 676
 677 static inline int
 678 rpc_task_need_encode(struct rpc_task *task)
 679 {
 680         return task->tk_rqstp->rq_snd_buf.len == 0;
 681 }
 682
 683 static inline void
 684 rpc_task_force_reencode(struct rpc_task *task)
 685 {
 686         task->tk_rqstp->rq_snd_buf.len = 0;
 687 }
 688
 689 /*
 690  * 3.   Encode arguments of an RPC call
 691  */
 692 static void
 693 call_encode(struct rpc_task *task)
 694 {
 695         struct rpc_rqst *req = task->tk_rqstp;
 696         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 697         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 698         unsigned int    bufsiz;
 699         kxdrproc_t      encode;
 700         u32             *p;
 701
 702         dprintk("RPC: %4d call_encode (status %d)\n",
 703                                 task->tk_pid, task->tk_status);
 704
 705         /* Default buffer setup */
 706         bufsiz = task->tk_bufsize >> 1;
 707         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 708         sndbuf->head[0].iov_len  = bufsiz;
 709         sndbuf->tail[0].iov_len  = 0;
 710         sndbuf->page_len         = 0;
 711         sndbuf->len              = 0;
 712         sndbuf->buflen           = bufsiz;
 713         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 714         rcvbuf->head[0].iov_len  = bufsiz;
 715         rcvbuf->tail[0].iov_len  = 0;
 716         rcvbuf->page_len         = 0;
 717         rcvbuf->len              = 0;
 718         rcvbuf->buflen           = bufsiz;
 719
 720         /* Encode header and provided arguments */
 721         encode = task->tk_msg.rpc_proc->p_encode;
 722         if (!(p = call_header(task))) {
 723                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 724                 rpc_exit(task, -EIO);
 725                 return;
 726         }
 727         if (encode == NULL)
 728                 return;
 729
 730         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 731                         task->tk_msg.rpc_argp);
 732         if (task->tk_status == -ENOMEM) {
 733                 /* XXX: Is this sane? */
 734                 rpc_delay(task, 3*HZ);
 735                 task->tk_status = -EAGAIN;
 736         }
 737 }
 738
 739 /*
 740  * 4.   Get the server port number if not yet set
 741  */
 742 static void
 743 call_bind(struct rpc_task *task)
 744 {
 745         struct rpc_clnt *clnt = task->tk_client;
 746
 747         dprintk("RPC: %4d call_bind (status %d)\n",
 748                                 task->tk_pid, task->tk_status);
 749
 750         task->tk_action = call_connect;
 751         if (!clnt->cl_port) {
 752                 task->tk_action = call_bind_status;
 753                 task->tk_timeout = task->tk_xprt->bind_timeout;
 754                 rpc_getport(task, clnt);
 755         }
 756 }
 757
 758 /*
 759  * 4a.  Sort out bind result
 760  */
 761 static void
 762 call_bind_status(struct rpc_task *task)
 763 {
 764         int status = -EACCES;
 765
 766         if (task->tk_status >= 0) {
 767                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 768                                         task->tk_pid, task->tk_status);
 769                 task->tk_status = 0;
 770                 task->tk_action = call_connect;
 771                 return;
 772         }
 773
 774         switch (task->tk_status) {
 775         case -EACCES:
 776                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 777                                 task->tk_pid);
 778                 rpc_delay(task, 3*HZ);
 779                 goto retry_bind;
 780         case -ETIMEDOUT:
 781                 dprintk("RPC: %4d rpcbind request timed out\n",
 782                                 task->tk_pid);
 783                 if (RPC_IS_SOFT(task)) {
 784                         status = -EIO;
 785                         break;
 786                 }
 787                 goto retry_bind;
 788         case -EPFNOSUPPORT:
 789                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 790                                 task->tk_pid);
 791                 break;
 792         case -EPROTONOSUPPORT:
 793                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 794                                 task->tk_pid);
 795                 break;
 796         default:
 797                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 798                                 task->tk_pid, -task->tk_status);
 799                 status = -EIO;
 800                 break;
 801         }
 802
 803         rpc_exit(task, status);
 804         return;
 805
 806 retry_bind:
 807         task->tk_status = 0;
 808         task->tk_action = call_bind;
 809         return;
 810 }
 811
 812 /*
 813  * 4b.  Connect to the RPC server
 814  */
 815 static void
 816 call_connect(struct rpc_task *task)
 817 {
 818         struct rpc_xprt *xprt = task->tk_xprt;
 819
 820         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 821                         task->tk_pid, xprt,
 822                         (xprt_connected(xprt) ? "is" : "is not"));
 823
 824         task->tk_action = call_transmit;
 825         if (!xprt_connected(xprt)) {
 826                 task->tk_action = call_connect_status;
 827                 if (task->tk_status < 0)
 828                         return;
 829                 xprt_connect(task);
 830         }
 831 }
 832
 833 /*
 834  * 4c.  Sort out connect result
 835  */
 836 static void
 837 call_connect_status(struct rpc_task *task)
 838 {
 839         struct rpc_clnt *clnt = task->tk_client;
 840         int status = task->tk_status;
 841
 842         dprintk("RPC: %5u call_connect_status (status %d)\n",
 843                                 task->tk_pid, task->tk_status);
 844
 845         task->tk_status = 0;
 846         if (status >= 0) {
 847                 clnt->cl_stats->netreconn++;
 848                 task->tk_action = call_transmit;
 849                 return;
 850         }
 851
 852         /* Something failed: remote service port may have changed */
 853         if (clnt->cl_autobind)
 854                 clnt->cl_port = 0;
 855
 856         switch (status) {
 857         case -ENOTCONN:
 858         case -ETIMEDOUT:
 859         case -EAGAIN:
 860                 task->tk_action = call_bind;
 861                 break;
 862         default:
 863                 rpc_exit(task, -EIO);
 864                 break;
 865         }
 866 }
 867
 868 /*
 869  * 5.   Transmit the RPC request, and wait for reply
 870  */
 871 static void
 872 call_transmit(struct rpc_task *task)
 873 {
 874         dprintk("RPC: %4d call_transmit (status %d)\n",
 875                                 task->tk_pid, task->tk_status);
 876
 877         task->tk_action = call_status;
 878         if (task->tk_status < 0)
 879                 return;
 880         task->tk_status = xprt_prepare_transmit(task);
 881         if (task->tk_status != 0)
 882                 return;
 883         /* Encode here so that rpcsec_gss can use correct sequence number. */
 884         if (rpc_task_need_encode(task)) {
 885                 task->tk_rqstp->rq_bytes_sent = 0;
 886                 call_encode(task);
 887                 /* Did the encode result in an error condition? */
 888                 if (task->tk_status != 0)
 889                         goto out_nosend;
 890         }
 891         task->tk_action = call_transmit_status;
 892         xprt_transmit(task);
 893         if (task->tk_status < 0)
 894                 return;
 895         if (!task->tk_msg.rpc_proc->p_decode) {
 896                 task->tk_action = rpc_exit_task;
 897                 rpc_wake_up_task(task);
 898         }
 899         return;
 900 out_nosend:
 901         /* release socket write lock before attempting to handle error */
 902         xprt_abort_transmit(task);
 903         rpc_task_force_reencode(task);
 904 }
 905
 906 /*
 907  * 6.   Sort out the RPC call status
 908  */
 909 static void
 910 call_status(struct rpc_task *task)
 911 {
 912         struct rpc_clnt *clnt = task->tk_client;
 913         struct rpc_rqst *req = task->tk_rqstp;
 914         int             status;
 915
 916         if (req->rq_received > 0 && !req->rq_bytes_sent)
 917                 task->tk_status = req->rq_received;
 918
 919         dprintk("RPC: %4d call_status (status %d)\n",
 920                                 task->tk_pid, task->tk_status);
 921
 922         status = task->tk_status;
 923         if (status >= 0) {
 924                 task->tk_action = call_decode;
 925                 return;
 926         }
 927
 928         task->tk_status = 0;
 929         switch(status) {
 930         case -ETIMEDOUT:
 931                 task->tk_action = call_timeout;
 932                 break;
 933         case -ECONNREFUSED:
 934         case -ENOTCONN:
 935                 if (clnt->cl_autobind)
 936                         clnt->cl_port = 0;
 937                 task->tk_action = call_bind;
 938                 break;
 939         case -EAGAIN:
 940                 task->tk_action = call_transmit;
 941                 break;
 942         case -EIO:
 943                 /* shutdown or soft timeout */
 944                 rpc_exit(task, status);
 945                 break;
 946         default:
 947                 if (clnt->cl_chatty)
 948                         printk("%s: RPC call returned error %d\n",
 949                                clnt->cl_protname, -status);
 950                 rpc_exit(task, status);
 951                 break;
 952         }
 953 }
 954
 955 /*
 956  * 6a.  Handle transmission errors.
 957  */
 958 static void
 959 call_transmit_status(struct rpc_task *task)
 960 {
 961         if (task->tk_status != -EAGAIN)
 962                 rpc_task_force_reencode(task);
 963         call_status(task);
 964 }
 965
 966 /*
 967  * 6b.  Handle RPC timeout
 968  *      We do not release the request slot, so we keep using the
 969  *      same XID for all retransmits.
 970  */
 971 static void
 972 call_timeout(struct rpc_task *task)
 973 {
 974         struct rpc_clnt *clnt = task->tk_client;
 975
 976         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 977                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 978                 goto retry;
 979         }
 980
 981         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 982         if (RPC_IS_SOFT(task)) {
 983                 if (clnt->cl_chatty)
 984                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 985                                 clnt->cl_protname, clnt->cl_server);
 986                 rpc_exit(task, -EIO);
 987                 return;
 988         }
 989
 990         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 991                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 992                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 993                         clnt->cl_protname, clnt->cl_server);
 994         }
 995         if (clnt->cl_autobind)
 996                 clnt->cl_port = 0;
 997
 998 retry:
 999         clnt->cl_stats->rpcretrans++;
1000         task->tk_action = call_bind;
1001         task->tk_status = 0;
1002 }
1003
1004 /*
1005  * 7.   Decode the RPC reply
1006  */
1007 static void
1008 call_decode(struct rpc_task *task)
1009 {
1010         struct rpc_clnt *clnt = task->tk_client;
1011         struct rpc_rqst *req = task->tk_rqstp;
1012         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1013         u32             *p;
1014
1015         dprintk("RPC: %4d call_decode (status %d)\n",
1016                                 task->tk_pid, task->tk_status);
1017
1018         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
1019                 printk(KERN_NOTICE "%s: server %s OK\n",
1020                         clnt->cl_protname, clnt->cl_server);
1021                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1022         }
1023
1024         if (task->tk_status < 12) {
1025                 if (!RPC_IS_SOFT(task)) {
1026                         task->tk_action = call_bind;
1027                         clnt->cl_stats->rpcretrans++;
1028                         goto out_retry;
1029                 }
1030                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1031                         clnt->cl_protname, task->tk_status);
1032                 rpc_exit(task, -EIO);
1033                 return;
1034         }
1035
1036         req->rq_rcv_buf.len = req->rq_private_buf.len;
1037
1038         /* Check that the softirq receive buffer is valid */
1039         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1040                                 sizeof(req->rq_rcv_buf)) != 0);
1041
1042         /* Verify the RPC header */
1043         p = call_verify(task);
1044         if (IS_ERR(p)) {
1045                 if (p == ERR_PTR(-EAGAIN))
1046                         goto out_retry;
1047                 return;
1048         }
1049
1050         task->tk_action = rpc_exit_task;
1051
1052         if (decode)
1053                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1054                                                       task->tk_msg.rpc_resp);
1055         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1056                                         task->tk_status);
1057         return;
1058 out_retry:
1059         req->rq_received = req->rq_private_buf.len = 0;
1060         task->tk_status = 0;
1061 }
1062
1063 /*
1064  * 8.   Refresh the credentials if rejected by the server
1065  */
1066 static void
1067 call_refresh(struct rpc_task *task)
1068 {
1069         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1070
1071         xprt_release(task);     /* Must do to obtain new XID */
1072         task->tk_action = call_refreshresult;
1073         task->tk_status = 0;
1074         task->tk_client->cl_stats->rpcauthrefresh++;
1075         rpcauth_refreshcred(task);
1076 }
1077
1078 /*
1079  * 8a.  Process the results of a credential refresh
1080  */
1081 static void
1082 call_refreshresult(struct rpc_task *task)
1083 {
1084         int status = task->tk_status;
1085         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1086                                 task->tk_pid, task->tk_status);
1087
1088         task->tk_status = 0;
1089         task->tk_action = call_reserve;
1090         if (status >= 0 && rpcauth_uptodatecred(task))
1091                 return;
1092         if (status == -EACCES) {
1093                 rpc_exit(task, -EACCES);
1094                 return;
1095         }
1096         task->tk_action = call_refresh;
1097         if (status != -ETIMEDOUT)
1098                 rpc_delay(task, 3*HZ);
1099         return;
1100 }
1101
1102 /*
1103  * Call header serialization
1104  */
1105 static u32 *
1106 call_header(struct rpc_task *task)
1107 {
1108         struct rpc_clnt *clnt = task->tk_client;
1109         struct rpc_rqst *req = task->tk_rqstp;
1110         u32             *p = req->rq_svec[0].iov_base;
1111
1112         /* FIXME: check buffer size? */
1113
1114         p = xprt_skip_transport_header(task->tk_xprt, p);
1115         *p++ = req->rq_xid;             /* XID */
1116         *p++ = htonl(RPC_CALL);         /* CALL */
1117         *p++ = htonl(RPC_VERSION);      /* RPC version */
1118         *p++ = htonl(clnt->cl_prog);    /* program number */
1119         *p++ = htonl(clnt->cl_vers);    /* program version */
1120         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1121         p = rpcauth_marshcred(task, p);
1122         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1123         return p;
1124 }
1125
1126 /*
1127  * Reply header verification
1128  */
1129 static u32 *
1130 call_verify(struct rpc_task *task)
1131 {
1132         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1133         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1134         u32     *p = iov->iov_base, n;
1135         int error = -EACCES;
1136
1137         if ((len -= 3) < 0)
1138                 goto out_overflow;
1139         p += 1; /* skip XID */
1140
1141         if ((n = ntohl(*p++)) != RPC_REPLY) {
1142                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1143                 goto out_garbage;
1144         }
1145         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1146                 if (--len < 0)
1147                         goto out_overflow;
1148                 switch ((n = ntohl(*p++))) {
1149                         case RPC_AUTH_ERROR:
1150                                 break;
1151                         case RPC_MISMATCH:
1152                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1153                                 error = -EPROTONOSUPPORT;
1154                                 goto out_err;
1155                         default:
1156                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1157                                 goto out_eio;
1158                 }
1159                 if (--len < 0)
1160                         goto out_overflow;
1161                 switch ((n = ntohl(*p++))) {
1162                 case RPC_AUTH_REJECTEDCRED:
1163                 case RPC_AUTH_REJECTEDVERF:
1164                 case RPCSEC_GSS_CREDPROBLEM:
1165                 case RPCSEC_GSS_CTXPROBLEM:
1166                         if (!task->tk_cred_retry)
1167                                 break;
1168                         task->tk_cred_retry--;
1169                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1170                                                         task->tk_pid);
1171                         rpcauth_invalcred(task);
1172                         task->tk_action = call_refresh;
1173                         goto out_retry;
1174                 case RPC_AUTH_BADCRED:
1175                 case RPC_AUTH_BADVERF:
1176                         /* possibly garbled cred/verf? */
1177                         if (!task->tk_garb_retry)
1178                                 break;
1179                         task->tk_garb_retry--;
1180                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1181                                                         task->tk_pid);
1182                         task->tk_action = call_bind;
1183                         goto out_retry;
1184                 case RPC_AUTH_TOOWEAK:
1185                         printk(KERN_NOTICE "call_verify: server requires stronger "
1186                                "authentication.\n");
1187                         break;
1188                 default:
1189                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1190                         error = -EIO;
1191                 }
1192                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1193                                                 task->tk_pid, n);
1194                 goto out_err;
1195         }
1196         if (!(p = rpcauth_checkverf(task, p))) {
1197                 printk(KERN_WARNING "call_verify: auth check failed\n");
1198                 goto out_garbage;               /* bad verifier, retry */
1199         }
1200         len = p - (u32 *)iov->iov_base - 1;
1201         if (len < 0)
1202                 goto out_overflow;
1203         switch ((n = ntohl(*p++))) {
1204         case RPC_SUCCESS:
1205                 return p;
1206         case RPC_PROG_UNAVAIL:
1207                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1208                                 (unsigned int)task->tk_client->cl_prog,
1209                                 task->tk_client->cl_server);
1210                 error = -EPFNOSUPPORT;
1211                 goto out_err;
1212         case RPC_PROG_MISMATCH:
1213                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1214                                 (unsigned int)task->tk_client->cl_prog,
1215                                 (unsigned int)task->tk_client->cl_vers,
1216                                 task->tk_client->cl_server);
1217                 error = -EPROTONOSUPPORT;
1218                 goto out_err;
1219         case RPC_PROC_UNAVAIL:
1220                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1221                                 task->tk_msg.rpc_proc,
1222                                 task->tk_client->cl_prog,
1223                                 task->tk_client->cl_vers,
1224                                 task->tk_client->cl_server);
1225                 error = -EOPNOTSUPP;
1226                 goto out_err;
1227         case RPC_GARBAGE_ARGS:
1228                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1229                 break;                  /* retry */
1230         default:
1231                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1232                 /* Also retry */
1233         }
1234
1235 out_garbage:
1236         task->tk_client->cl_stats->rpcgarbage++;
1237         if (task->tk_garb_retry) {
1238                 task->tk_garb_retry--;
1239                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1240                 task->tk_action = call_bind;
1241 out_retry:
1242                 return ERR_PTR(-EAGAIN);
1243         }
1244         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1245 out_eio:
1246         error = -EIO;
1247 out_err:
1248         rpc_exit(task, error);
1249         return ERR_PTR(error);
1250 out_overflow:
1251         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1252         goto out_garbage;
1253 }
1254
1255 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1256 {
1257         return 0;
1258 }
1259
1260 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1261 {
1262         return 0;
1263 }
1264
1265 static struct rpc_procinfo rpcproc_null = {
1266         .p_encode = rpcproc_encode_null,
1267         .p_decode = rpcproc_decode_null,
1268 };
1269
1270 int rpc_ping(struct rpc_clnt *clnt, int flags)
1271 {
1272         struct rpc_message msg = {
1273                 .rpc_proc = &rpcproc_null,
1274         };
1275         int err;
1276         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1277         err = rpc_call_sync(clnt, &msg, flags);
1278         put_rpccred(msg.rpc_cred);
1279         return err;
1280 }