net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/rpcclnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/in.h>
  31 #include <linux/utsname.h>
  32
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36
  37 #include <linux/nfs.h>
  38
  39
  40 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  41
  42 #ifdef RPC_DEBUG
  43 # define RPCDBG_FACILITY        RPCDBG_CALL
  44 #endif
  45
  46 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  47
  48
  49 static void     call_start(struct rpc_task *task);
  50 static void     call_reserve(struct rpc_task *task);
  51 static void     call_reserveresult(struct rpc_task *task);
  52 static void     call_allocate(struct rpc_task *task);
  53 static void     call_encode(struct rpc_task *task);
  54 static void     call_decode(struct rpc_task *task);
  55 static void     call_bind(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_refresh(struct rpc_task *task);
  59 static void     call_refreshresult(struct rpc_task *task);
  60 static void     call_timeout(struct rpc_task *task);
  61 static void     call_connect(struct rpc_task *task);
  62 static void     call_connect_status(struct rpc_task *task);
  63 static u32 *    call_header(struct rpc_task *task);
  64 static u32 *    call_verify(struct rpc_task *task);
  65
  66
  67 static int
  68 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  69 {
  70         static uint32_t clntid;
  71         int error;
  72
  73         if (dir_name == NULL)
  74                 return 0;
  75         for (;;) {
  76                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  77                                 "%s/clnt%x", dir_name,
  78                                 (unsigned int)clntid++);
  79                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  80                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  81                 if (!IS_ERR(clnt->cl_dentry))
  82                         return 0;
  83                 error = PTR_ERR(clnt->cl_dentry);
  84                 if (error != -EEXIST) {
  85                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  86                                         clnt->cl_pathname, error);
  87                         return error;
  88                 }
  89         }
  90 }
  91
  92 /*
  93  * Create an RPC client
  94  * FIXME: This should also take a flags argument (as in task->tk_flags).
  95  * It's called (among others) from pmap_create_client, which may in
  96  * turn be called by an async task. In this case, rpciod should not be
  97  * made to sleep too long.
  98  */
  99 struct rpc_clnt *
 100 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 101                   struct rpc_program *program, u32 vers,
 102                   rpc_authflavor_t flavor)
 103 {
 104         struct rpc_version      *version;
 105         struct rpc_clnt         *clnt = NULL;
 106         struct rpc_auth         *auth;
 107         int err;
 108         int len;
 109
 110         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 111                 program->name, servname, xprt);
 112
 113         err = -EINVAL;
 114         if (!xprt)
 115                 goto out_err;
 116         if (vers >= program->nrvers || !(version = program->version[vers]))
 117                 goto out_err;
 118
 119         err = -ENOMEM;
 120         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 121         if (!clnt)
 122                 goto out_err;
 123         memset(clnt, 0, sizeof(*clnt));
 124         atomic_set(&clnt->cl_users, 0);
 125         atomic_set(&clnt->cl_count, 1);
 126         clnt->cl_parent = clnt;
 127
 128         clnt->cl_server = clnt->cl_inline_name;
 129         len = strlen(servname) + 1;
 130         if (len > sizeof(clnt->cl_inline_name)) {
 131                 char *buf = kmalloc(len, GFP_KERNEL);
 132                 if (buf != 0)
 133                         clnt->cl_server = buf;
 134                 else
 135                         len = sizeof(clnt->cl_inline_name);
 136         }
 137         strlcpy(clnt->cl_server, servname, len);
 138
 139         clnt->cl_xprt     = xprt;
 140         clnt->cl_procinfo = version->procs;
 141         clnt->cl_maxproc  = version->nrprocs;
 142         clnt->cl_protname = program->name;
 143         clnt->cl_pmap     = &clnt->cl_pmap_default;
 144         clnt->cl_port     = xprt->addr.sin_port;
 145         clnt->cl_prog     = program->number;
 146         clnt->cl_vers     = version->number;
 147         clnt->cl_prot     = xprt->prot;
 148         clnt->cl_stats    = program->stats;
 149         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 150
 151         if (!clnt->cl_port)
 152                 clnt->cl_autobind = 1;
 153
 154         clnt->cl_rtt = &clnt->cl_rtt_default;
 155         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 156
 157         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 158         if (err < 0)
 159                 goto out_no_path;
 160
 161         auth = rpcauth_create(flavor, clnt);
 162         if (IS_ERR(auth)) {
 163                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 164                                 flavor);
 165                 err = PTR_ERR(auth);
 166                 goto out_no_auth;
 167         }
 168
 169         /* save the nodename */
 170         clnt->cl_nodelen = strlen(system_utsname.nodename);
 171         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 172                 clnt->cl_nodelen = UNX_MAXNODENAME;
 173         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 174         return clnt;
 175
 176 out_no_auth:
 177         rpc_rmdir(clnt->cl_pathname);
 178 out_no_path:
 179         if (clnt->cl_server != clnt->cl_inline_name)
 180                 kfree(clnt->cl_server);
 181         kfree(clnt);
 182 out_err:
 183         xprt_destroy(xprt);
 184         return ERR_PTR(err);
 185 }
 186
 187 /**
 188  * Create an RPC client
 189  * @xprt - pointer to xprt struct
 190  * @servname - name of server
 191  * @info - rpc_program
 192  * @version - rpc_program version
 193  * @authflavor - rpc_auth flavour to use
 194  *
 195  * Creates an RPC client structure, then pings the server in order to
 196  * determine if it is up, and if it supports this program and version.
 197  *
 198  * This function should never be called by asynchronous tasks such as
 199  * the portmapper.
 200  */
 201 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 202                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 203 {
 204         struct rpc_clnt *clnt;
 205         int err;
 206
 207         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 208         if (IS_ERR(clnt))
 209                 return clnt;
 210         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 211         if (err == 0)
 212                 return clnt;
 213         rpc_shutdown_client(clnt);
 214         return ERR_PTR(err);
 215 }
 216
 217 /*
 218  * This function clones the RPC client structure. It allows us to share the
 219  * same transport while varying parameters such as the authentication
 220  * flavour.
 221  */
 222 struct rpc_clnt *
 223 rpc_clone_client(struct rpc_clnt *clnt)
 224 {
 225         struct rpc_clnt *new;
 226
 227         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
 228         if (!new)
 229                 goto out_no_clnt;
 230         memcpy(new, clnt, sizeof(*new));
 231         atomic_set(&new->cl_count, 1);
 232         atomic_set(&new->cl_users, 0);
 233         new->cl_parent = clnt;
 234         atomic_inc(&clnt->cl_count);
 235         /* Duplicate portmapper */
 236         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 237         /* Turn off autobind on clones */
 238         new->cl_autobind = 0;
 239         new->cl_oneshot = 0;
 240         new->cl_dead = 0;
 241         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 242         if (new->cl_auth)
 243                 atomic_inc(&new->cl_auth->au_count);
 244         return new;
 245 out_no_clnt:
 246         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 247         return ERR_PTR(-ENOMEM);
 248 }
 249
 250 /*
 251  * Properly shut down an RPC client, terminating all outstanding
 252  * requests. Note that we must be certain that cl_oneshot and
 253  * cl_dead are cleared, or else the client would be destroyed
 254  * when the last task releases it.
 255  */
 256 int
 257 rpc_shutdown_client(struct rpc_clnt *clnt)
 258 {
 259         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 260                         clnt->cl_protname, clnt->cl_server,
 261                         atomic_read(&clnt->cl_users));
 262
 263         while (atomic_read(&clnt->cl_users) > 0) {
 264                 /* Don't let rpc_release_client destroy us */
 265                 clnt->cl_oneshot = 0;
 266                 clnt->cl_dead = 0;
 267                 rpc_killall_tasks(clnt);
 268                 sleep_on_timeout(&destroy_wait, 1*HZ);
 269         }
 270
 271         if (atomic_read(&clnt->cl_users) < 0) {
 272                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 273                                 clnt, atomic_read(&clnt->cl_users));
 274 #ifdef RPC_DEBUG
 275                 rpc_show_tasks();
 276 #endif
 277                 BUG();
 278         }
 279
 280         return rpc_destroy_client(clnt);
 281 }
 282
 283 /*
 284  * Delete an RPC client
 285  */
 286 int
 287 rpc_destroy_client(struct rpc_clnt *clnt)
 288 {
 289         if (!atomic_dec_and_test(&clnt->cl_count))
 290                 return 1;
 291         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 292
 293         dprintk("RPC: destroying %s client for %s\n",
 294                         clnt->cl_protname, clnt->cl_server);
 295         if (clnt->cl_auth) {
 296                 rpcauth_destroy(clnt->cl_auth);
 297                 clnt->cl_auth = NULL;
 298         }
 299         if (clnt->cl_parent != clnt) {
 300                 rpc_destroy_client(clnt->cl_parent);
 301                 goto out_free;
 302         }
 303         if (clnt->cl_pathname[0])
 304                 rpc_rmdir(clnt->cl_pathname);
 305         if (clnt->cl_xprt) {
 306                 xprt_destroy(clnt->cl_xprt);
 307                 clnt->cl_xprt = NULL;
 308         }
 309         if (clnt->cl_server != clnt->cl_inline_name)
 310                 kfree(clnt->cl_server);
 311 out_free:
 312         kfree(clnt);
 313         return 0;
 314 }
 315
 316 /*
 317  * Release an RPC client
 318  */
 319 void
 320 rpc_release_client(struct rpc_clnt *clnt)
 321 {
 322         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 323                                 clnt, atomic_read(&clnt->cl_users));
 324
 325         if (!atomic_dec_and_test(&clnt->cl_users))
 326                 return;
 327         wake_up(&destroy_wait);
 328         if (clnt->cl_oneshot || clnt->cl_dead)
 329                 rpc_destroy_client(clnt);
 330 }
 331
 332 /*
 333  * Default callback for async RPC calls
 334  */
 335 static void
 336 rpc_default_callback(struct rpc_task *task)
 337 {
 338 }
 339
 340 /*
 341  *      Export the signal mask handling for aysnchronous code that
 342  *      sleeps on RPC calls
 343  */
 344
 345 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 346 {
 347         unsigned long   sigallow = sigmask(SIGKILL);
 348         unsigned long   irqflags;
 349
 350         /* Turn off various signals */
 351         if (clnt->cl_intr) {
 352                 struct k_sigaction *action = current->sighand->action;
 353                 if (action[SIGINT-1].sa.sa_handler == SIG_DFL)
 354                         sigallow |= sigmask(SIGINT);
 355                 if (action[SIGQUIT-1].sa.sa_handler == SIG_DFL)
 356                         sigallow |= sigmask(SIGQUIT);
 357         }
 358         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 359         *oldset = current->blocked;
 360         siginitsetinv(&current->blocked, sigallow & ~oldset->sig[0]);
 361         recalc_sigpending();
 362         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 363 }
 364
 365 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 366 {
 367         unsigned long   irqflags;
 368
 369         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 370         current->blocked = *oldset;
 371         recalc_sigpending();
 372         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 373 }
 374
 375 /*
 376  * New rpc_call implementation
 377  */
 378 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 379 {
 380         struct rpc_task *task;
 381         sigset_t        oldset;
 382         int             status;
 383
 384         /* If this client is slain all further I/O fails */
 385         if (clnt->cl_dead)
 386                 return -EIO;
 387
 388         BUG_ON(flags & RPC_TASK_ASYNC);
 389
 390         rpc_clnt_sigmask(clnt, &oldset);
 391
 392         status = -ENOMEM;
 393         task = rpc_new_task(clnt, NULL, flags);
 394         if (task == NULL)
 395                 goto out;
 396
 397         rpc_call_setup(task, msg, 0);
 398
 399         /* Set up the call info struct and execute the task */
 400         if (task->tk_status == 0)
 401                 status = rpc_execute(task);
 402         else {
 403                 status = task->tk_status;
 404                 rpc_release_task(task);
 405         }
 406
 407 out:
 408         rpc_clnt_sigunmask(clnt, &oldset);
 409
 410         return status;
 411 }
 412
 413 /*
 414  * New rpc_call implementation
 415  */
 416 int
 417 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 418                rpc_action callback, void *data)
 419 {
 420         struct rpc_task *task;
 421         sigset_t        oldset;
 422         int             status;
 423
 424         /* If this client is slain all further I/O fails */
 425         if (clnt->cl_dead)
 426                 return -EIO;
 427
 428         flags |= RPC_TASK_ASYNC;
 429
 430         rpc_clnt_sigmask(clnt, &oldset);
 431
 432         /* Create/initialize a new RPC task */
 433         if (!callback)
 434                 callback = rpc_default_callback;
 435         status = -ENOMEM;
 436         if (!(task = rpc_new_task(clnt, callback, flags)))
 437                 goto out;
 438         task->tk_calldata = data;
 439
 440         rpc_call_setup(task, msg, 0);
 441
 442         /* Set up the call info struct and execute the task */
 443         status = task->tk_status;
 444         if (status == 0)
 445                 rpc_execute(task);
 446         else
 447                 rpc_release_task(task);
 448
 449 out:
 450         rpc_clnt_sigunmask(clnt, &oldset);
 451
 452         return status;
 453 }
 454
 455
 456 void
 457 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 458 {
 459         task->tk_msg   = *msg;
 460         task->tk_flags |= flags;
 461         /* Bind the user cred */
 462         if (task->tk_msg.rpc_cred != NULL)
 463                 rpcauth_holdcred(task);
 464         else
 465                 rpcauth_bindcred(task);
 466
 467         if (task->tk_status == 0)
 468                 task->tk_action = call_start;
 469         else
 470                 task->tk_action = NULL;
 471 }
 472
 473 void
 474 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 475 {
 476         struct rpc_xprt *xprt = clnt->cl_xprt;
 477
 478         xprt->sndsize = 0;
 479         if (sndsize)
 480                 xprt->sndsize = sndsize + RPC_SLACK_SPACE;
 481         xprt->rcvsize = 0;
 482         if (rcvsize)
 483                 xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
 484         if (xprt_connected(xprt))
 485                 xprt_sock_setbufsize(xprt);
 486 }
 487
 488 /*
 489  * Return size of largest payload RPC client can support, in bytes
 490  *
 491  * For stream transports, this is one RPC record fragment (see RFC
 492  * 1831), as we don't support multi-record requests yet.  For datagram
 493  * transports, this is the size of an IP packet minus the IP, UDP, and
 494  * RPC header sizes.
 495  */
 496 size_t rpc_max_payload(struct rpc_clnt *clnt)
 497 {
 498         return clnt->cl_xprt->max_payload;
 499 }
 500 EXPORT_SYMBOL(rpc_max_payload);
 501
 502 /*
 503  * Restart an (async) RPC call. Usually called from within the
 504  * exit handler.
 505  */
 506 void
 507 rpc_restart_call(struct rpc_task *task)
 508 {
 509         if (RPC_ASSASSINATED(task))
 510                 return;
 511
 512         task->tk_action = call_start;
 513 }
 514
 515 /*
 516  * 0.  Initial state
 517  *
 518  *     Other FSM states can be visited zero or more times, but
 519  *     this state is visited exactly once for each RPC.
 520  */
 521 static void
 522 call_start(struct rpc_task *task)
 523 {
 524         struct rpc_clnt *clnt = task->tk_client;
 525
 526         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 527                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 528                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 529
 530         /* Increment call count */
 531         task->tk_msg.rpc_proc->p_count++;
 532         clnt->cl_stats->rpccnt++;
 533         task->tk_action = call_reserve;
 534 }
 535
 536 /*
 537  * 1.   Reserve an RPC call slot
 538  */
 539 static void
 540 call_reserve(struct rpc_task *task)
 541 {
 542         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 543
 544         if (!rpcauth_uptodatecred(task)) {
 545                 task->tk_action = call_refresh;
 546                 return;
 547         }
 548
 549         task->tk_status  = 0;
 550         task->tk_action  = call_reserveresult;
 551         xprt_reserve(task);
 552 }
 553
 554 /*
 555  * 1b.  Grok the result of xprt_reserve()
 556  */
 557 static void
 558 call_reserveresult(struct rpc_task *task)
 559 {
 560         int status = task->tk_status;
 561
 562         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 563                                 task->tk_pid, task->tk_status);
 564
 565         /*
 566          * After a call to xprt_reserve(), we must have either
 567          * a request slot or else an error status.
 568          */
 569         task->tk_status = 0;
 570         if (status >= 0) {
 571                 if (task->tk_rqstp) {
 572                         task->tk_action = call_allocate;
 573                         return;
 574                 }
 575
 576                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 577                                 __FUNCTION__, status);
 578                 rpc_exit(task, -EIO);
 579                 return;
 580         }
 581
 582         /*
 583          * Even though there was an error, we may have acquired
 584          * a request slot somehow.  Make sure not to leak it.
 585          */
 586         if (task->tk_rqstp) {
 587                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 588                                 __FUNCTION__, status);
 589                 xprt_release(task);
 590         }
 591
 592         switch (status) {
 593         case -EAGAIN:   /* woken up; retry */
 594                 task->tk_action = call_reserve;
 595                 return;
 596         case -EIO:      /* probably a shutdown */
 597                 break;
 598         default:
 599                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 600                                 __FUNCTION__, status);
 601                 break;
 602         }
 603         rpc_exit(task, status);
 604 }
 605
 606 /*
 607  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 608  *      (Note: buffer memory is freed in rpc_task_release).
 609  */
 610 static void
 611 call_allocate(struct rpc_task *task)
 612 {
 613         unsigned int    bufsiz;
 614
 615         dprintk("RPC: %4d call_allocate (status %d)\n",
 616                                 task->tk_pid, task->tk_status);
 617         task->tk_action = call_bind;
 618         if (task->tk_buffer)
 619                 return;
 620
 621         /* FIXME: compute buffer requirements more exactly using
 622          * auth->au_wslack */
 623         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 624
 625         if (rpc_malloc(task, bufsiz << 1) != NULL)
 626                 return;
 627         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 628
 629         if (RPC_IS_ASYNC(task) || !(task->tk_client->cl_intr && signalled())) {
 630                 xprt_release(task);
 631                 task->tk_action = call_reserve;
 632                 rpc_delay(task, HZ>>4);
 633                 return;
 634         }
 635
 636         rpc_exit(task, -ERESTARTSYS);
 637 }
 638
 639 /*
 640  * 3.   Encode arguments of an RPC call
 641  */
 642 static void
 643 call_encode(struct rpc_task *task)
 644 {
 645         struct rpc_clnt *clnt = task->tk_client;
 646         struct rpc_rqst *req = task->tk_rqstp;
 647         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 648         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 649         unsigned int    bufsiz;
 650         kxdrproc_t      encode;
 651         int             status;
 652         u32             *p;
 653
 654         dprintk("RPC: %4d call_encode (status %d)\n",
 655                                 task->tk_pid, task->tk_status);
 656
 657         /* Default buffer setup */
 658         bufsiz = task->tk_bufsize >> 1;
 659         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 660         sndbuf->head[0].iov_len  = bufsiz;
 661         sndbuf->tail[0].iov_len  = 0;
 662         sndbuf->page_len         = 0;
 663         sndbuf->len              = 0;
 664         sndbuf->buflen           = bufsiz;
 665         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 666         rcvbuf->head[0].iov_len  = bufsiz;
 667         rcvbuf->tail[0].iov_len  = 0;
 668         rcvbuf->page_len         = 0;
 669         rcvbuf->len              = 0;
 670         rcvbuf->buflen           = bufsiz;
 671
 672         /* Encode header and provided arguments */
 673         encode = task->tk_msg.rpc_proc->p_encode;
 674         if (!(p = call_header(task))) {
 675                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 676                 rpc_exit(task, -EIO);
 677                 return;
 678         }
 679         if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
 680                                                  task->tk_msg.rpc_argp)) < 0) {
 681                 printk(KERN_WARNING "%s: can't encode arguments: %d\n",
 682                                 clnt->cl_protname, -status);
 683                 rpc_exit(task, status);
 684         }
 685 }
 686
 687 /*
 688  * 4.   Get the server port number if not yet set
 689  */
 690 static void
 691 call_bind(struct rpc_task *task)
 692 {
 693         struct rpc_clnt *clnt = task->tk_client;
 694         struct rpc_xprt *xprt = clnt->cl_xprt;
 695
 696         dprintk("RPC: %4d call_bind xprt %p %s connected\n", task->tk_pid,
 697                         xprt, (xprt_connected(xprt) ? "is" : "is not"));
 698
 699         task->tk_action = (xprt_connected(xprt)) ? call_transmit : call_connect;
 700
 701         if (!clnt->cl_port) {
 702                 task->tk_action = call_connect;
 703                 task->tk_timeout = RPC_CONNECT_TIMEOUT;
 704                 rpc_getport(task, clnt);
 705         }
 706 }
 707
 708 /*
 709  * 4a.  Connect to the RPC server (TCP case)
 710  */
 711 static void
 712 call_connect(struct rpc_task *task)
 713 {
 714         struct rpc_clnt *clnt = task->tk_client;
 715
 716         dprintk("RPC: %4d call_connect status %d\n",
 717                                 task->tk_pid, task->tk_status);
 718
 719         if (xprt_connected(clnt->cl_xprt)) {
 720                 task->tk_action = call_transmit;
 721                 return;
 722         }
 723         task->tk_action = call_connect_status;
 724         if (task->tk_status < 0)
 725                 return;
 726         xprt_connect(task);
 727 }
 728
 729 /*
 730  * 4b. Sort out connect result
 731  */
 732 static void
 733 call_connect_status(struct rpc_task *task)
 734 {
 735         struct rpc_clnt *clnt = task->tk_client;
 736         int status = task->tk_status;
 737
 738         task->tk_status = 0;
 739         if (status >= 0) {
 740                 clnt->cl_stats->netreconn++;
 741                 task->tk_action = call_transmit;
 742                 return;
 743         }
 744
 745         /* Something failed: we may have to rebind */
 746         if (clnt->cl_autobind)
 747                 clnt->cl_port = 0;
 748         switch (status) {
 749         case -ENOTCONN:
 750         case -ETIMEDOUT:
 751         case -EAGAIN:
 752                 task->tk_action = (clnt->cl_port == 0) ? call_bind : call_connect;
 753                 break;
 754         default:
 755                 rpc_exit(task, -EIO);
 756         }
 757 }
 758
 759 /*
 760  * 5.   Transmit the RPC request, and wait for reply
 761  */
 762 static void
 763 call_transmit(struct rpc_task *task)
 764 {
 765         dprintk("RPC: %4d call_transmit (status %d)\n",
 766                                 task->tk_pid, task->tk_status);
 767
 768         task->tk_action = call_status;
 769         if (task->tk_status < 0)
 770                 return;
 771         task->tk_status = xprt_prepare_transmit(task);
 772         if (task->tk_status != 0)
 773                 return;
 774         /* Encode here so that rpcsec_gss can use correct sequence number. */
 775         if (!task->tk_rqstp->rq_bytes_sent)
 776                 call_encode(task);
 777         if (task->tk_status < 0)
 778                 return;
 779         xprt_transmit(task);
 780         if (task->tk_status < 0)
 781                 return;
 782         if (!task->tk_msg.rpc_proc->p_decode) {
 783                 task->tk_action = NULL;
 784                 rpc_wake_up_task(task);
 785         }
 786 }
 787
 788 /*
 789  * 6.   Sort out the RPC call status
 790  */
 791 static void
 792 call_status(struct rpc_task *task)
 793 {
 794         struct rpc_clnt *clnt = task->tk_client;
 795         struct rpc_rqst *req = task->tk_rqstp;
 796         int             status;
 797
 798         if (req->rq_received > 0 && !req->rq_bytes_sent)
 799                 task->tk_status = req->rq_received;
 800
 801         dprintk("RPC: %4d call_status (status %d)\n",
 802                                 task->tk_pid, task->tk_status);
 803
 804         status = task->tk_status;
 805         if (status >= 0) {
 806                 task->tk_action = call_decode;
 807                 return;
 808         }
 809
 810         task->tk_status = 0;
 811         switch(status) {
 812         case -ETIMEDOUT:
 813                 task->tk_action = call_timeout;
 814                 break;
 815         case -ECONNREFUSED:
 816         case -ENOTCONN:
 817                 req->rq_bytes_sent = 0;
 818                 if (clnt->cl_autobind)
 819                         clnt->cl_port = 0;
 820                 task->tk_action = call_bind;
 821                 break;
 822         case -EAGAIN:
 823                 task->tk_action = call_transmit;
 824                 break;
 825         case -EIO:
 826                 /* shutdown or soft timeout */
 827                 rpc_exit(task, status);
 828                 break;
 829         default:
 830                 if (clnt->cl_chatty)
 831                         printk("%s: RPC call returned error %d\n",
 832                                clnt->cl_protname, -status);
 833                 rpc_exit(task, status);
 834                 break;
 835         }
 836 }
 837
 838 /*
 839  * 6a.  Handle RPC timeout
 840  *      We do not release the request slot, so we keep using the
 841  *      same XID for all retransmits.
 842  */
 843 static void
 844 call_timeout(struct rpc_task *task)
 845 {
 846         struct rpc_clnt *clnt = task->tk_client;
 847
 848         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 849                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 850                 goto retry;
 851         }
 852
 853         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 854         if (RPC_IS_SOFT(task)) {
 855                 if (clnt->cl_chatty)
 856                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 857                                 clnt->cl_protname, clnt->cl_server);
 858                 rpc_exit(task, -EIO);
 859                 return;
 860         }
 861
 862         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 863                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 864                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 865                         clnt->cl_protname, clnt->cl_server);
 866         }
 867         if (clnt->cl_autobind)
 868                 clnt->cl_port = 0;
 869
 870 retry:
 871         clnt->cl_stats->rpcretrans++;
 872         task->tk_action = call_bind;
 873         task->tk_status = 0;
 874 }
 875
 876 /*
 877  * 7.   Decode the RPC reply
 878  */
 879 static void
 880 call_decode(struct rpc_task *task)
 881 {
 882         struct rpc_clnt *clnt = task->tk_client;
 883         struct rpc_rqst *req = task->tk_rqstp;
 884         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
 885         u32             *p;
 886
 887         dprintk("RPC: %4d call_decode (status %d)\n",
 888                                 task->tk_pid, task->tk_status);
 889
 890         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
 891                 printk(KERN_NOTICE "%s: server %s OK\n",
 892                         clnt->cl_protname, clnt->cl_server);
 893                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
 894         }
 895
 896         if (task->tk_status < 12) {
 897                 if (!RPC_IS_SOFT(task)) {
 898                         task->tk_action = call_bind;
 899                         clnt->cl_stats->rpcretrans++;
 900                         goto out_retry;
 901                 }
 902                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
 903                         clnt->cl_protname, task->tk_status);
 904                 rpc_exit(task, -EIO);
 905                 return;
 906         }
 907
 908         req->rq_rcv_buf.len = req->rq_private_buf.len;
 909
 910         /* Check that the softirq receive buffer is valid */
 911         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
 912                                 sizeof(req->rq_rcv_buf)) != 0);
 913
 914         /* Verify the RPC header */
 915         if (!(p = call_verify(task))) {
 916                 if (task->tk_action == NULL)
 917                         return;
 918                 goto out_retry;
 919         }
 920
 921         task->tk_action = NULL;
 922
 923         if (decode)
 924                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
 925                                                       task->tk_msg.rpc_resp);
 926         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
 927                                         task->tk_status);
 928         return;
 929 out_retry:
 930         req->rq_received = req->rq_private_buf.len = 0;
 931         task->tk_status = 0;
 932 }
 933
 934 /*
 935  * 8.   Refresh the credentials if rejected by the server
 936  */
 937 static void
 938 call_refresh(struct rpc_task *task)
 939 {
 940         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
 941
 942         xprt_release(task);     /* Must do to obtain new XID */
 943         task->tk_action = call_refreshresult;
 944         task->tk_status = 0;
 945         task->tk_client->cl_stats->rpcauthrefresh++;
 946         rpcauth_refreshcred(task);
 947 }
 948
 949 /*
 950  * 8a.  Process the results of a credential refresh
 951  */
 952 static void
 953 call_refreshresult(struct rpc_task *task)
 954 {
 955         int status = task->tk_status;
 956         dprintk("RPC: %4d call_refreshresult (status %d)\n",
 957                                 task->tk_pid, task->tk_status);
 958
 959         task->tk_status = 0;
 960         task->tk_action = call_reserve;
 961         if (status >= 0 && rpcauth_uptodatecred(task))
 962                 return;
 963         if (status == -EACCES) {
 964                 rpc_exit(task, -EACCES);
 965                 return;
 966         }
 967         task->tk_action = call_refresh;
 968         if (status != -ETIMEDOUT)
 969                 rpc_delay(task, 3*HZ);
 970         return;
 971 }
 972
 973 /*
 974  * Call header serialization
 975  */
 976 static u32 *
 977 call_header(struct rpc_task *task)
 978 {
 979         struct rpc_clnt *clnt = task->tk_client;
 980         struct rpc_xprt *xprt = clnt->cl_xprt;
 981         struct rpc_rqst *req = task->tk_rqstp;
 982         u32             *p = req->rq_svec[0].iov_base;
 983
 984         /* FIXME: check buffer size? */
 985         if (xprt->stream)
 986                 *p++ = 0;               /* fill in later */
 987         *p++ = req->rq_xid;             /* XID */
 988         *p++ = htonl(RPC_CALL);         /* CALL */
 989         *p++ = htonl(RPC_VERSION);      /* RPC version */
 990         *p++ = htonl(clnt->cl_prog);    /* program number */
 991         *p++ = htonl(clnt->cl_vers);    /* program version */
 992         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
 993         p = rpcauth_marshcred(task, p);
 994         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
 995         return p;
 996 }
 997
 998 /*
 999  * Reply header verification
1000  */
1001 static u32 *
1002 call_verify(struct rpc_task *task)
1003 {
1004         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1005         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1006         u32     *p = iov->iov_base, n;
1007         int error = -EACCES;
1008
1009         if ((len -= 3) < 0)
1010                 goto out_overflow;
1011         p += 1; /* skip XID */
1012
1013         if ((n = ntohl(*p++)) != RPC_REPLY) {
1014                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1015                 goto out_retry;
1016         }
1017         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1018                 if (--len < 0)
1019                         goto out_overflow;
1020                 switch ((n = ntohl(*p++))) {
1021                         case RPC_AUTH_ERROR:
1022                                 break;
1023                         case RPC_MISMATCH:
1024                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1025                                 error = -EPROTONOSUPPORT;
1026                                 goto out_err;
1027                         default:
1028                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1029                                 goto out_eio;
1030                 }
1031                 if (--len < 0)
1032                         goto out_overflow;
1033                 switch ((n = ntohl(*p++))) {
1034                 case RPC_AUTH_REJECTEDCRED:
1035                 case RPC_AUTH_REJECTEDVERF:
1036                 case RPCSEC_GSS_CREDPROBLEM:
1037                 case RPCSEC_GSS_CTXPROBLEM:
1038                         if (!task->tk_cred_retry)
1039                                 break;
1040                         task->tk_cred_retry--;
1041                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1042                                                         task->tk_pid);
1043                         rpcauth_invalcred(task);
1044                         task->tk_action = call_refresh;
1045                         return NULL;
1046                 case RPC_AUTH_BADCRED:
1047                 case RPC_AUTH_BADVERF:
1048                         /* possibly garbled cred/verf? */
1049                         if (!task->tk_garb_retry)
1050                                 break;
1051                         task->tk_garb_retry--;
1052                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1053                                                         task->tk_pid);
1054                         task->tk_action = call_bind;
1055                         return NULL;
1056                 case RPC_AUTH_TOOWEAK:
1057                         printk(KERN_NOTICE "call_verify: server requires stronger "
1058                                "authentication.\n");
1059                         break;
1060                 default:
1061                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1062                         error = -EIO;
1063                 }
1064                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1065                                                 task->tk_pid, n);
1066                 goto out_err;
1067         }
1068         if (!(p = rpcauth_checkverf(task, p))) {
1069                 printk(KERN_WARNING "call_verify: auth check failed\n");
1070                 goto out_retry;         /* bad verifier, retry */
1071         }
1072         len = p - (u32 *)iov->iov_base - 1;
1073         if (len < 0)
1074                 goto out_overflow;
1075         switch ((n = ntohl(*p++))) {
1076         case RPC_SUCCESS:
1077                 return p;
1078         case RPC_PROG_UNAVAIL:
1079                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1080                                 (unsigned int)task->tk_client->cl_prog,
1081                                 task->tk_client->cl_server);
1082                 error = -EPFNOSUPPORT;
1083                 goto out_err;
1084         case RPC_PROG_MISMATCH:
1085                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1086                                 (unsigned int)task->tk_client->cl_prog,
1087                                 (unsigned int)task->tk_client->cl_vers,
1088                                 task->tk_client->cl_server);
1089                 error = -EPROTONOSUPPORT;
1090                 goto out_err;
1091         case RPC_PROC_UNAVAIL:
1092                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1093                                 task->tk_msg.rpc_proc,
1094                                 task->tk_client->cl_prog,
1095                                 task->tk_client->cl_vers,
1096                                 task->tk_client->cl_server);
1097                 error = -EOPNOTSUPP;
1098                 goto out_err;
1099         case RPC_GARBAGE_ARGS:
1100                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1101                 break;                  /* retry */
1102         default:
1103                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1104                 /* Also retry */
1105         }
1106
1107 out_retry:
1108         task->tk_client->cl_stats->rpcgarbage++;
1109         if (task->tk_garb_retry) {
1110                 task->tk_garb_retry--;
1111                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1112                 task->tk_action = call_bind;
1113                 return NULL;
1114         }
1115         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1116 out_eio:
1117         error = -EIO;
1118 out_err:
1119         rpc_exit(task, error);
1120         return NULL;
1121 out_overflow:
1122         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1123         goto out_retry;
1124 }
1125
1126 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1127 {
1128         return 0;
1129 }
1130
1131 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1132 {
1133         return 0;
1134 }
1135
1136 static struct rpc_procinfo rpcproc_null = {
1137         .p_encode = rpcproc_encode_null,
1138         .p_decode = rpcproc_decode_null,
1139 };
1140
1141 int rpc_ping(struct rpc_clnt *clnt, int flags)
1142 {
1143         struct rpc_message msg = {
1144                 .rpc_proc = &rpcproc_null,
1145         };
1146         int err;
1147         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1148         err = rpc_call_sync(clnt, &msg, flags);
1149         put_rpccred(msg.rpc_cred);
1150         return err;
1151 }