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 #include <linux/workqueue.h>
  32
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35 #include <linux/sunrpc/metrics.h>
  36
  37
  38 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  39
  40 #ifdef RPC_DEBUG
  41 # define RPCDBG_FACILITY        RPCDBG_CALL
  42 #endif
  43
  44 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  45
  46
  47 static void     call_start(struct rpc_task *task);
  48 static void     call_reserve(struct rpc_task *task);
  49 static void     call_reserveresult(struct rpc_task *task);
  50 static void     call_allocate(struct rpc_task *task);
  51 static void     call_encode(struct rpc_task *task);
  52 static void     call_decode(struct rpc_task *task);
  53 static void     call_bind(struct rpc_task *task);
  54 static void     call_bind_status(struct rpc_task *task);
  55 static void     call_transmit(struct rpc_task *task);
  56 static void     call_status(struct rpc_task *task);
  57 static void     call_transmit_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_no_xprt;
 116         if (vers >= program->nrvers || !(version = program->version[vers]))
 117                 goto out_err;
 118
 119         err = -ENOMEM;
 120         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         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 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 out_no_xprt:
 186         return ERR_PTR(err);
 187 }
 188
 189 /**
 190  * Create an RPC client
 191  * @xprt - pointer to xprt struct
 192  * @servname - name of server
 193  * @info - rpc_program
 194  * @version - rpc_program version
 195  * @authflavor - rpc_auth flavour to use
 196  *
 197  * Creates an RPC client structure, then pings the server in order to
 198  * determine if it is up, and if it supports this program and version.
 199  *
 200  * This function should never be called by asynchronous tasks such as
 201  * the portmapper.
 202  */
 203 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 204                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 205 {
 206         struct rpc_clnt *clnt;
 207         int err;
 208
 209         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 210         if (IS_ERR(clnt))
 211                 return clnt;
 212         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 213         if (err == 0)
 214                 return clnt;
 215         rpc_shutdown_client(clnt);
 216         return ERR_PTR(err);
 217 }
 218
 219 /*
 220  * This function clones the RPC client structure. It allows us to share the
 221  * same transport while varying parameters such as the authentication
 222  * flavour.
 223  */
 224 struct rpc_clnt *
 225 rpc_clone_client(struct rpc_clnt *clnt)
 226 {
 227         struct rpc_clnt *new;
 228
 229         new = kmalloc(sizeof(*new), GFP_KERNEL);
 230         if (!new)
 231                 goto out_no_clnt;
 232         memcpy(new, clnt, sizeof(*new));
 233         atomic_set(&new->cl_count, 1);
 234         atomic_set(&new->cl_users, 0);
 235         new->cl_parent = clnt;
 236         atomic_inc(&clnt->cl_count);
 237         /* Duplicate portmapper */
 238         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 239         /* Turn off autobind on clones */
 240         new->cl_autobind = 0;
 241         new->cl_oneshot = 0;
 242         new->cl_dead = 0;
 243         dget(new->cl_dentry);
 244         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 245         if (new->cl_auth)
 246                 atomic_inc(&new->cl_auth->au_count);
 247         new->cl_pmap            = &new->cl_pmap_default;
 248         new->cl_metrics         = rpc_alloc_iostats(clnt);
 249         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 250         return new;
 251 out_no_clnt:
 252         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 253         return ERR_PTR(-ENOMEM);
 254 }
 255
 256 /*
 257  * Properly shut down an RPC client, terminating all outstanding
 258  * requests. Note that we must be certain that cl_oneshot and
 259  * cl_dead are cleared, or else the client would be destroyed
 260  * when the last task releases it.
 261  */
 262 int
 263 rpc_shutdown_client(struct rpc_clnt *clnt)
 264 {
 265         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 266                         clnt->cl_protname, clnt->cl_server,
 267                         atomic_read(&clnt->cl_users));
 268
 269         while (atomic_read(&clnt->cl_users) > 0) {
 270                 /* Don't let rpc_release_client destroy us */
 271                 clnt->cl_oneshot = 0;
 272                 clnt->cl_dead = 0;
 273                 rpc_killall_tasks(clnt);
 274                 wait_event_timeout(destroy_wait,
 275                         !atomic_read(&clnt->cl_users), 1*HZ);
 276         }
 277
 278         if (atomic_read(&clnt->cl_users) < 0) {
 279                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 280                                 clnt, atomic_read(&clnt->cl_users));
 281 #ifdef RPC_DEBUG
 282                 rpc_show_tasks();
 283 #endif
 284                 BUG();
 285         }
 286
 287         return rpc_destroy_client(clnt);
 288 }
 289
 290 /*
 291  * Delete an RPC client
 292  */
 293 int
 294 rpc_destroy_client(struct rpc_clnt *clnt)
 295 {
 296         if (!atomic_dec_and_test(&clnt->cl_count))
 297                 return 1;
 298         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 299
 300         dprintk("RPC: destroying %s client for %s\n",
 301                         clnt->cl_protname, clnt->cl_server);
 302         if (clnt->cl_auth) {
 303                 rpcauth_destroy(clnt->cl_auth);
 304                 clnt->cl_auth = NULL;
 305         }
 306         if (clnt->cl_parent != clnt) {
 307                 rpc_destroy_client(clnt->cl_parent);
 308                 goto out_free;
 309         }
 310         if (clnt->cl_pathname[0])
 311                 rpc_rmdir(clnt->cl_pathname);
 312         if (clnt->cl_xprt) {
 313                 xprt_destroy(clnt->cl_xprt);
 314                 clnt->cl_xprt = NULL;
 315         }
 316         if (clnt->cl_server != clnt->cl_inline_name)
 317                 kfree(clnt->cl_server);
 318 out_free:
 319         rpc_free_iostats(clnt->cl_metrics);
 320         clnt->cl_metrics = NULL;
 321         if (clnt->cl_dentry)
 322                 dput(clnt->cl_dentry);
 323         kfree(clnt);
 324         return 0;
 325 }
 326
 327 /*
 328  * Release an RPC client
 329  */
 330 void
 331 rpc_release_client(struct rpc_clnt *clnt)
 332 {
 333         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 334                                 clnt, atomic_read(&clnt->cl_users));
 335
 336         if (!atomic_dec_and_test(&clnt->cl_users))
 337                 return;
 338         wake_up(&destroy_wait);
 339         if (clnt->cl_oneshot || clnt->cl_dead)
 340                 rpc_destroy_client(clnt);
 341 }
 342
 343 /**
 344  * rpc_bind_new_program - bind a new RPC program to an existing client
 345  * @old - old rpc_client
 346  * @program - rpc program to set
 347  * @vers - rpc program version
 348  *
 349  * Clones the rpc client and sets up a new RPC program. This is mainly
 350  * of use for enabling different RPC programs to share the same transport.
 351  * The Sun NFSv2/v3 ACL protocol can do this.
 352  */
 353 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 354                                       struct rpc_program *program,
 355                                       int vers)
 356 {
 357         struct rpc_clnt *clnt;
 358         struct rpc_version *version;
 359         int err;
 360
 361         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 362         version = program->version[vers];
 363         clnt = rpc_clone_client(old);
 364         if (IS_ERR(clnt))
 365                 goto out;
 366         clnt->cl_procinfo = version->procs;
 367         clnt->cl_maxproc  = version->nrprocs;
 368         clnt->cl_protname = program->name;
 369         clnt->cl_prog     = program->number;
 370         clnt->cl_vers     = version->number;
 371         clnt->cl_stats    = program->stats;
 372         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 373         if (err != 0) {
 374                 rpc_shutdown_client(clnt);
 375                 clnt = ERR_PTR(err);
 376         }
 377 out:
 378         return clnt;
 379 }
 380
 381 /*
 382  * Default callback for async RPC calls
 383  */
 384 static void
 385 rpc_default_callback(struct rpc_task *task, void *data)
 386 {
 387 }
 388
 389 static const struct rpc_call_ops rpc_default_ops = {
 390         .rpc_call_done = rpc_default_callback,
 391 };
 392
 393 /*
 394  *      Export the signal mask handling for synchronous code that
 395  *      sleeps on RPC calls
 396  */
 397 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 398
 399 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 400 {
 401         unsigned long   sigallow = sigmask(SIGKILL);
 402         sigset_t sigmask;
 403
 404         /* Block all signals except those listed in sigallow */
 405         if (intr)
 406                 sigallow |= RPC_INTR_SIGNALS;
 407         siginitsetinv(&sigmask, sigallow);
 408         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 409 }
 410
 411 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 412 {
 413         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 414 }
 415
 416 static inline void rpc_restore_sigmask(sigset_t *oldset)
 417 {
 418         sigprocmask(SIG_SETMASK, oldset, NULL);
 419 }
 420
 421 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 422 {
 423         rpc_save_sigmask(oldset, clnt->cl_intr);
 424 }
 425
 426 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 427 {
 428         rpc_restore_sigmask(oldset);
 429 }
 430
 431 /*
 432  * New rpc_call implementation
 433  */
 434 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 435 {
 436         struct rpc_task *task;
 437         sigset_t        oldset;
 438         int             status;
 439
 440         /* If this client is slain all further I/O fails */
 441         if (clnt->cl_dead)
 442                 return -EIO;
 443
 444         BUG_ON(flags & RPC_TASK_ASYNC);
 445
 446         status = -ENOMEM;
 447         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 448         if (task == NULL)
 449                 goto out;
 450
 451         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 452         rpc_task_sigmask(task, &oldset);
 453
 454         rpc_call_setup(task, msg, 0);
 455
 456         /* Set up the call info struct and execute the task */
 457         status = task->tk_status;
 458         if (status == 0) {
 459                 atomic_inc(&task->tk_count);
 460                 status = rpc_execute(task);
 461                 if (status == 0)
 462                         status = task->tk_status;
 463         }
 464         rpc_restore_sigmask(&oldset);
 465         rpc_release_task(task);
 466 out:
 467         return status;
 468 }
 469
 470 /*
 471  * New rpc_call implementation
 472  */
 473 int
 474 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 475                const struct rpc_call_ops *tk_ops, void *data)
 476 {
 477         struct rpc_task *task;
 478         sigset_t        oldset;
 479         int             status;
 480
 481         /* If this client is slain all further I/O fails */
 482         if (clnt->cl_dead)
 483                 return -EIO;
 484
 485         flags |= RPC_TASK_ASYNC;
 486
 487         /* Create/initialize a new RPC task */
 488         status = -ENOMEM;
 489         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 490                 goto out;
 491
 492         /* Mask signals on GSS_AUTH upcalls */
 493         rpc_task_sigmask(task, &oldset);
 494
 495         rpc_call_setup(task, msg, 0);
 496
 497         /* Set up the call info struct and execute the task */
 498         status = task->tk_status;
 499         if (status == 0)
 500                 rpc_execute(task);
 501         else
 502                 rpc_release_task(task);
 503
 504         rpc_restore_sigmask(&oldset);
 505 out:
 506         return status;
 507 }
 508
 509
 510 void
 511 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 512 {
 513         task->tk_msg   = *msg;
 514         task->tk_flags |= flags;
 515         /* Bind the user cred */
 516         if (task->tk_msg.rpc_cred != NULL)
 517                 rpcauth_holdcred(task);
 518         else
 519                 rpcauth_bindcred(task);
 520
 521         if (task->tk_status == 0)
 522                 task->tk_action = call_start;
 523         else
 524                 task->tk_action = rpc_exit_task;
 525 }
 526
 527 void
 528 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 529 {
 530         struct rpc_xprt *xprt = clnt->cl_xprt;
 531         if (xprt->ops->set_buffer_size)
 532                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 533 }
 534
 535 /*
 536  * Return size of largest payload RPC client can support, in bytes
 537  *
 538  * For stream transports, this is one RPC record fragment (see RFC
 539  * 1831), as we don't support multi-record requests yet.  For datagram
 540  * transports, this is the size of an IP packet minus the IP, UDP, and
 541  * RPC header sizes.
 542  */
 543 size_t rpc_max_payload(struct rpc_clnt *clnt)
 544 {
 545         return clnt->cl_xprt->max_payload;
 546 }
 547 EXPORT_SYMBOL(rpc_max_payload);
 548
 549 /**
 550  * rpc_force_rebind - force transport to check that remote port is unchanged
 551  * @clnt: client to rebind
 552  *
 553  */
 554 void rpc_force_rebind(struct rpc_clnt *clnt)
 555 {
 556         if (clnt->cl_autobind)
 557                 clnt->cl_port = 0;
 558 }
 559 EXPORT_SYMBOL(rpc_force_rebind);
 560
 561 /*
 562  * Restart an (async) RPC call. Usually called from within the
 563  * exit handler.
 564  */
 565 void
 566 rpc_restart_call(struct rpc_task *task)
 567 {
 568         if (RPC_ASSASSINATED(task))
 569                 return;
 570
 571         task->tk_action = call_start;
 572 }
 573
 574 /*
 575  * 0.  Initial state
 576  *
 577  *     Other FSM states can be visited zero or more times, but
 578  *     this state is visited exactly once for each RPC.
 579  */
 580 static void
 581 call_start(struct rpc_task *task)
 582 {
 583         struct rpc_clnt *clnt = task->tk_client;
 584
 585         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 586                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 587                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 588
 589         /* Increment call count */
 590         task->tk_msg.rpc_proc->p_count++;
 591         clnt->cl_stats->rpccnt++;
 592         task->tk_action = call_reserve;
 593 }
 594
 595 /*
 596  * 1.   Reserve an RPC call slot
 597  */
 598 static void
 599 call_reserve(struct rpc_task *task)
 600 {
 601         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 602
 603         if (!rpcauth_uptodatecred(task)) {
 604                 task->tk_action = call_refresh;
 605                 return;
 606         }
 607
 608         task->tk_status  = 0;
 609         task->tk_action  = call_reserveresult;
 610         xprt_reserve(task);
 611 }
 612
 613 /*
 614  * 1b.  Grok the result of xprt_reserve()
 615  */
 616 static void
 617 call_reserveresult(struct rpc_task *task)
 618 {
 619         int status = task->tk_status;
 620
 621         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 622                                 task->tk_pid, task->tk_status);
 623
 624         /*
 625          * After a call to xprt_reserve(), we must have either
 626          * a request slot or else an error status.
 627          */
 628         task->tk_status = 0;
 629         if (status >= 0) {
 630                 if (task->tk_rqstp) {
 631                         task->tk_action = call_allocate;
 632                         return;
 633                 }
 634
 635                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 636                                 __FUNCTION__, status);
 637                 rpc_exit(task, -EIO);
 638                 return;
 639         }
 640
 641         /*
 642          * Even though there was an error, we may have acquired
 643          * a request slot somehow.  Make sure not to leak it.
 644          */
 645         if (task->tk_rqstp) {
 646                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 647                                 __FUNCTION__, status);
 648                 xprt_release(task);
 649         }
 650
 651         switch (status) {
 652         case -EAGAIN:   /* woken up; retry */
 653                 task->tk_action = call_reserve;
 654                 return;
 655         case -EIO:      /* probably a shutdown */
 656                 break;
 657         default:
 658                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 659                                 __FUNCTION__, status);
 660                 break;
 661         }
 662         rpc_exit(task, status);
 663 }
 664
 665 /*
 666  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 667  *      (Note: buffer memory is freed in xprt_release).
 668  */
 669 static void
 670 call_allocate(struct rpc_task *task)
 671 {
 672         struct rpc_rqst *req = task->tk_rqstp;
 673         struct rpc_xprt *xprt = task->tk_xprt;
 674         unsigned int    bufsiz;
 675
 676         dprintk("RPC: %4d call_allocate (status %d)\n",
 677                                 task->tk_pid, task->tk_status);
 678         task->tk_action = call_bind;
 679         if (req->rq_buffer)
 680                 return;
 681
 682         /* FIXME: compute buffer requirements more exactly using
 683          * auth->au_wslack */
 684         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 685
 686         if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
 687                 return;
 688         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 689
 690         if (RPC_IS_ASYNC(task) || !signalled()) {
 691                 xprt_release(task);
 692                 task->tk_action = call_reserve;
 693                 rpc_delay(task, HZ>>4);
 694                 return;
 695         }
 696
 697         rpc_exit(task, -ERESTARTSYS);
 698 }
 699
 700 static inline int
 701 rpc_task_need_encode(struct rpc_task *task)
 702 {
 703         return task->tk_rqstp->rq_snd_buf.len == 0;
 704 }
 705
 706 static inline void
 707 rpc_task_force_reencode(struct rpc_task *task)
 708 {
 709         task->tk_rqstp->rq_snd_buf.len = 0;
 710 }
 711
 712 /*
 713  * 3.   Encode arguments of an RPC call
 714  */
 715 static void
 716 call_encode(struct rpc_task *task)
 717 {
 718         struct rpc_rqst *req = task->tk_rqstp;
 719         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 720         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 721         unsigned int    bufsiz;
 722         kxdrproc_t      encode;
 723         u32             *p;
 724
 725         dprintk("RPC: %4d call_encode (status %d)\n",
 726                                 task->tk_pid, task->tk_status);
 727
 728         /* Default buffer setup */
 729         bufsiz = req->rq_bufsize >> 1;
 730         sndbuf->head[0].iov_base = (void *)req->rq_buffer;
 731         sndbuf->head[0].iov_len  = bufsiz;
 732         sndbuf->tail[0].iov_len  = 0;
 733         sndbuf->page_len         = 0;
 734         sndbuf->len              = 0;
 735         sndbuf->buflen           = bufsiz;
 736         rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
 737         rcvbuf->head[0].iov_len  = bufsiz;
 738         rcvbuf->tail[0].iov_len  = 0;
 739         rcvbuf->page_len         = 0;
 740         rcvbuf->len              = 0;
 741         rcvbuf->buflen           = bufsiz;
 742
 743         /* Encode header and provided arguments */
 744         encode = task->tk_msg.rpc_proc->p_encode;
 745         if (!(p = call_header(task))) {
 746                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 747                 rpc_exit(task, -EIO);
 748                 return;
 749         }
 750         if (encode == NULL)
 751                 return;
 752
 753         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 754                         task->tk_msg.rpc_argp);
 755         if (task->tk_status == -ENOMEM) {
 756                 /* XXX: Is this sane? */
 757                 rpc_delay(task, 3*HZ);
 758                 task->tk_status = -EAGAIN;
 759         }
 760 }
 761
 762 /*
 763  * 4.   Get the server port number if not yet set
 764  */
 765 static void
 766 call_bind(struct rpc_task *task)
 767 {
 768         struct rpc_clnt *clnt = task->tk_client;
 769
 770         dprintk("RPC: %4d call_bind (status %d)\n",
 771                                 task->tk_pid, task->tk_status);
 772
 773         task->tk_action = call_connect;
 774         if (!clnt->cl_port) {
 775                 task->tk_action = call_bind_status;
 776                 task->tk_timeout = task->tk_xprt->bind_timeout;
 777                 rpc_getport(task, clnt);
 778         }
 779 }
 780
 781 /*
 782  * 4a.  Sort out bind result
 783  */
 784 static void
 785 call_bind_status(struct rpc_task *task)
 786 {
 787         int status = -EACCES;
 788
 789         if (task->tk_status >= 0) {
 790                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 791                                         task->tk_pid, task->tk_status);
 792                 task->tk_status = 0;
 793                 task->tk_action = call_connect;
 794                 return;
 795         }
 796
 797         switch (task->tk_status) {
 798         case -EACCES:
 799                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 800                                 task->tk_pid);
 801                 rpc_delay(task, 3*HZ);
 802                 goto retry_bind;
 803         case -ETIMEDOUT:
 804                 dprintk("RPC: %4d rpcbind request timed out\n",
 805                                 task->tk_pid);
 806                 if (RPC_IS_SOFT(task)) {
 807                         status = -EIO;
 808                         break;
 809                 }
 810                 goto retry_bind;
 811         case -EPFNOSUPPORT:
 812                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 813                                 task->tk_pid);
 814                 break;
 815         case -EPROTONOSUPPORT:
 816                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 817                                 task->tk_pid);
 818                 break;
 819         default:
 820                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 821                                 task->tk_pid, -task->tk_status);
 822                 status = -EIO;
 823                 break;
 824         }
 825
 826         rpc_exit(task, status);
 827         return;
 828
 829 retry_bind:
 830         task->tk_status = 0;
 831         task->tk_action = call_bind;
 832         return;
 833 }
 834
 835 /*
 836  * 4b.  Connect to the RPC server
 837  */
 838 static void
 839 call_connect(struct rpc_task *task)
 840 {
 841         struct rpc_xprt *xprt = task->tk_xprt;
 842
 843         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 844                         task->tk_pid, xprt,
 845                         (xprt_connected(xprt) ? "is" : "is not"));
 846
 847         task->tk_action = call_transmit;
 848         if (!xprt_connected(xprt)) {
 849                 task->tk_action = call_connect_status;
 850                 if (task->tk_status < 0)
 851                         return;
 852                 xprt_connect(task);
 853         }
 854 }
 855
 856 /*
 857  * 4c.  Sort out connect result
 858  */
 859 static void
 860 call_connect_status(struct rpc_task *task)
 861 {
 862         struct rpc_clnt *clnt = task->tk_client;
 863         int status = task->tk_status;
 864
 865         dprintk("RPC: %5u call_connect_status (status %d)\n",
 866                                 task->tk_pid, task->tk_status);
 867
 868         task->tk_status = 0;
 869         if (status >= 0) {
 870                 clnt->cl_stats->netreconn++;
 871                 task->tk_action = call_transmit;
 872                 return;
 873         }
 874
 875         /* Something failed: remote service port may have changed */
 876         rpc_force_rebind(clnt);
 877
 878         switch (status) {
 879         case -ENOTCONN:
 880         case -ETIMEDOUT:
 881         case -EAGAIN:
 882                 task->tk_action = call_bind;
 883                 break;
 884         default:
 885                 rpc_exit(task, -EIO);
 886                 break;
 887         }
 888 }
 889
 890 /*
 891  * 5.   Transmit the RPC request, and wait for reply
 892  */
 893 static void
 894 call_transmit(struct rpc_task *task)
 895 {
 896         dprintk("RPC: %4d call_transmit (status %d)\n",
 897                                 task->tk_pid, task->tk_status);
 898
 899         task->tk_action = call_status;
 900         if (task->tk_status < 0)
 901                 return;
 902         task->tk_status = xprt_prepare_transmit(task);
 903         if (task->tk_status != 0)
 904                 return;
 905         /* Encode here so that rpcsec_gss can use correct sequence number. */
 906         if (rpc_task_need_encode(task)) {
 907                 task->tk_rqstp->rq_bytes_sent = 0;
 908                 call_encode(task);
 909                 /* Did the encode result in an error condition? */
 910                 if (task->tk_status != 0)
 911                         goto out_nosend;
 912         }
 913         task->tk_action = call_transmit_status;
 914         xprt_transmit(task);
 915         if (task->tk_status < 0)
 916                 return;
 917         if (!task->tk_msg.rpc_proc->p_decode) {
 918                 task->tk_action = rpc_exit_task;
 919                 rpc_wake_up_task(task);
 920         }
 921         return;
 922 out_nosend:
 923         /* release socket write lock before attempting to handle error */
 924         xprt_abort_transmit(task);
 925         rpc_task_force_reencode(task);
 926 }
 927
 928 /*
 929  * 6.   Sort out the RPC call status
 930  */
 931 static void
 932 call_status(struct rpc_task *task)
 933 {
 934         struct rpc_clnt *clnt = task->tk_client;
 935         struct rpc_rqst *req = task->tk_rqstp;
 936         int             status;
 937
 938         if (req->rq_received > 0 && !req->rq_bytes_sent)
 939                 task->tk_status = req->rq_received;
 940
 941         dprintk("RPC: %4d call_status (status %d)\n",
 942                                 task->tk_pid, task->tk_status);
 943
 944         status = task->tk_status;
 945         if (status >= 0) {
 946                 task->tk_action = call_decode;
 947                 return;
 948         }
 949
 950         task->tk_status = 0;
 951         switch(status) {
 952         case -ETIMEDOUT:
 953                 task->tk_action = call_timeout;
 954                 break;
 955         case -ECONNREFUSED:
 956         case -ENOTCONN:
 957                 rpc_force_rebind(clnt);
 958                 task->tk_action = call_bind;
 959                 break;
 960         case -EAGAIN:
 961                 task->tk_action = call_transmit;
 962                 break;
 963         case -EIO:
 964                 /* shutdown or soft timeout */
 965                 rpc_exit(task, status);
 966                 break;
 967         default:
 968                 printk("%s: RPC call returned error %d\n",
 969                                clnt->cl_protname, -status);
 970                 rpc_exit(task, status);
 971                 break;
 972         }
 973 }
 974
 975 /*
 976  * 6a.  Handle transmission errors.
 977  */
 978 static void
 979 call_transmit_status(struct rpc_task *task)
 980 {
 981         if (task->tk_status != -EAGAIN)
 982                 rpc_task_force_reencode(task);
 983         call_status(task);
 984 }
 985
 986 /*
 987  * 6b.  Handle RPC timeout
 988  *      We do not release the request slot, so we keep using the
 989  *      same XID for all retransmits.
 990  */
 991 static void
 992 call_timeout(struct rpc_task *task)
 993 {
 994         struct rpc_clnt *clnt = task->tk_client;
 995
 996         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 997                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 998                 goto retry;
 999         }
1000
1001         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
1002         task->tk_timeouts++;
1003
1004         if (RPC_IS_SOFT(task)) {
1005                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1006                                 clnt->cl_protname, clnt->cl_server);
1007                 rpc_exit(task, -EIO);
1008                 return;
1009         }
1010
1011         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1012                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1013                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1014                         clnt->cl_protname, clnt->cl_server);
1015         }
1016         rpc_force_rebind(clnt);
1017
1018 retry:
1019         clnt->cl_stats->rpcretrans++;
1020         task->tk_action = call_bind;
1021         task->tk_status = 0;
1022 }
1023
1024 /*
1025  * 7.   Decode the RPC reply
1026  */
1027 static void
1028 call_decode(struct rpc_task *task)
1029 {
1030         struct rpc_clnt *clnt = task->tk_client;
1031         struct rpc_rqst *req = task->tk_rqstp;
1032         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1033         u32             *p;
1034
1035         dprintk("RPC: %4d call_decode (status %d)\n",
1036                                 task->tk_pid, task->tk_status);
1037
1038         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1039                 printk(KERN_NOTICE "%s: server %s OK\n",
1040                         clnt->cl_protname, clnt->cl_server);
1041                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1042         }
1043
1044         if (task->tk_status < 12) {
1045                 if (!RPC_IS_SOFT(task)) {
1046                         task->tk_action = call_bind;
1047                         clnt->cl_stats->rpcretrans++;
1048                         goto out_retry;
1049                 }
1050                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1051                         clnt->cl_protname, task->tk_status);
1052                 rpc_exit(task, -EIO);
1053                 return;
1054         }
1055
1056         req->rq_rcv_buf.len = req->rq_private_buf.len;
1057
1058         /* Check that the softirq receive buffer is valid */
1059         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1060                                 sizeof(req->rq_rcv_buf)) != 0);
1061
1062         /* Verify the RPC header */
1063         p = call_verify(task);
1064         if (IS_ERR(p)) {
1065                 if (p == ERR_PTR(-EAGAIN))
1066                         goto out_retry;
1067                 return;
1068         }
1069
1070         task->tk_action = rpc_exit_task;
1071
1072         if (decode)
1073                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1074                                                       task->tk_msg.rpc_resp);
1075         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1076                                         task->tk_status);
1077         return;
1078 out_retry:
1079         req->rq_received = req->rq_private_buf.len = 0;
1080         task->tk_status = 0;
1081 }
1082
1083 /*
1084  * 8.   Refresh the credentials if rejected by the server
1085  */
1086 static void
1087 call_refresh(struct rpc_task *task)
1088 {
1089         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1090
1091         xprt_release(task);     /* Must do to obtain new XID */
1092         task->tk_action = call_refreshresult;
1093         task->tk_status = 0;
1094         task->tk_client->cl_stats->rpcauthrefresh++;
1095         rpcauth_refreshcred(task);
1096 }
1097
1098 /*
1099  * 8a.  Process the results of a credential refresh
1100  */
1101 static void
1102 call_refreshresult(struct rpc_task *task)
1103 {
1104         int status = task->tk_status;
1105         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1106                                 task->tk_pid, task->tk_status);
1107
1108         task->tk_status = 0;
1109         task->tk_action = call_reserve;
1110         if (status >= 0 && rpcauth_uptodatecred(task))
1111                 return;
1112         if (status == -EACCES) {
1113                 rpc_exit(task, -EACCES);
1114                 return;
1115         }
1116         task->tk_action = call_refresh;
1117         if (status != -ETIMEDOUT)
1118                 rpc_delay(task, 3*HZ);
1119         return;
1120 }
1121
1122 /*
1123  * Call header serialization
1124  */
1125 static u32 *
1126 call_header(struct rpc_task *task)
1127 {
1128         struct rpc_clnt *clnt = task->tk_client;
1129         struct rpc_rqst *req = task->tk_rqstp;
1130         u32             *p = req->rq_svec[0].iov_base;
1131
1132         /* FIXME: check buffer size? */
1133
1134         p = xprt_skip_transport_header(task->tk_xprt, p);
1135         *p++ = req->rq_xid;             /* XID */
1136         *p++ = htonl(RPC_CALL);         /* CALL */
1137         *p++ = htonl(RPC_VERSION);      /* RPC version */
1138         *p++ = htonl(clnt->cl_prog);    /* program number */
1139         *p++ = htonl(clnt->cl_vers);    /* program version */
1140         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1141         p = rpcauth_marshcred(task, p);
1142         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1143         return p;
1144 }
1145
1146 /*
1147  * Reply header verification
1148  */
1149 static u32 *
1150 call_verify(struct rpc_task *task)
1151 {
1152         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1153         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1154         u32     *p = iov->iov_base, n;
1155         int error = -EACCES;
1156
1157         if ((len -= 3) < 0)
1158                 goto out_overflow;
1159         p += 1; /* skip XID */
1160
1161         if ((n = ntohl(*p++)) != RPC_REPLY) {
1162                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1163                 goto out_garbage;
1164         }
1165         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1166                 if (--len < 0)
1167                         goto out_overflow;
1168                 switch ((n = ntohl(*p++))) {
1169                         case RPC_AUTH_ERROR:
1170                                 break;
1171                         case RPC_MISMATCH:
1172                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1173                                 error = -EPROTONOSUPPORT;
1174                                 goto out_err;
1175                         default:
1176                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1177                                 goto out_eio;
1178                 }
1179                 if (--len < 0)
1180                         goto out_overflow;
1181                 switch ((n = ntohl(*p++))) {
1182                 case RPC_AUTH_REJECTEDCRED:
1183                 case RPC_AUTH_REJECTEDVERF:
1184                 case RPCSEC_GSS_CREDPROBLEM:
1185                 case RPCSEC_GSS_CTXPROBLEM:
1186                         if (!task->tk_cred_retry)
1187                                 break;
1188                         task->tk_cred_retry--;
1189                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1190                                                         task->tk_pid);
1191                         rpcauth_invalcred(task);
1192                         task->tk_action = call_refresh;
1193                         goto out_retry;
1194                 case RPC_AUTH_BADCRED:
1195                 case RPC_AUTH_BADVERF:
1196                         /* possibly garbled cred/verf? */
1197                         if (!task->tk_garb_retry)
1198                                 break;
1199                         task->tk_garb_retry--;
1200                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1201                                                         task->tk_pid);
1202                         task->tk_action = call_bind;
1203                         goto out_retry;
1204                 case RPC_AUTH_TOOWEAK:
1205                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1206                                "authentication.\n", task->tk_client->cl_server);
1207                         break;
1208                 default:
1209                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1210                         error = -EIO;
1211                 }
1212                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1213                                                 task->tk_pid, n);
1214                 goto out_err;
1215         }
1216         if (!(p = rpcauth_checkverf(task, p))) {
1217                 printk(KERN_WARNING "call_verify: auth check failed\n");
1218                 goto out_garbage;               /* bad verifier, retry */
1219         }
1220         len = p - (u32 *)iov->iov_base - 1;
1221         if (len < 0)
1222                 goto out_overflow;
1223         switch ((n = ntohl(*p++))) {
1224         case RPC_SUCCESS:
1225                 return p;
1226         case RPC_PROG_UNAVAIL:
1227                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1228                                 (unsigned int)task->tk_client->cl_prog,
1229                                 task->tk_client->cl_server);
1230                 error = -EPFNOSUPPORT;
1231                 goto out_err;
1232         case RPC_PROG_MISMATCH:
1233                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1234                                 (unsigned int)task->tk_client->cl_prog,
1235                                 (unsigned int)task->tk_client->cl_vers,
1236                                 task->tk_client->cl_server);
1237                 error = -EPROTONOSUPPORT;
1238                 goto out_err;
1239         case RPC_PROC_UNAVAIL:
1240                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1241                                 task->tk_msg.rpc_proc,
1242                                 task->tk_client->cl_prog,
1243                                 task->tk_client->cl_vers,
1244                                 task->tk_client->cl_server);
1245                 error = -EOPNOTSUPP;
1246                 goto out_err;
1247         case RPC_GARBAGE_ARGS:
1248                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1249                 break;                  /* retry */
1250         default:
1251                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1252                 /* Also retry */
1253         }
1254
1255 out_garbage:
1256         task->tk_client->cl_stats->rpcgarbage++;
1257         if (task->tk_garb_retry) {
1258                 task->tk_garb_retry--;
1259                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1260                 task->tk_action = call_bind;
1261 out_retry:
1262                 return ERR_PTR(-EAGAIN);
1263         }
1264         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1265 out_eio:
1266         error = -EIO;
1267 out_err:
1268         rpc_exit(task, error);
1269         return ERR_PTR(error);
1270 out_overflow:
1271         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1272         goto out_garbage;
1273 }
1274
1275 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1276 {
1277         return 0;
1278 }
1279
1280 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1281 {
1282         return 0;
1283 }
1284
1285 static struct rpc_procinfo rpcproc_null = {
1286         .p_encode = rpcproc_encode_null,
1287         .p_decode = rpcproc_decode_null,
1288 };
1289
1290 int rpc_ping(struct rpc_clnt *clnt, int flags)
1291 {
1292         struct rpc_message msg = {
1293                 .rpc_proc = &rpcproc_null,
1294         };
1295         int err;
1296         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1297         err = rpc_call_sync(clnt, &msg, flags);
1298         put_rpccred(msg.rpc_cred);
1299         return err;
1300 }