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