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   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/utsname.h>
  31
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35
  36 #include <linux/nfs.h>
  37
  38
  39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  40
  41 #ifdef RPC_DEBUG
  42 # define RPCDBG_FACILITY        RPCDBG_CALL
  43 #endif
  44
  45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  46
  47
  48 static void     call_start(struct rpc_task *task);
  49 static void     call_reserve(struct rpc_task *task);
  50 static void     call_reserveresult(struct rpc_task *task);
  51 static void     call_allocate(struct rpc_task *task);
  52 static void     call_encode(struct rpc_task *task);
  53 static void     call_decode(struct rpc_task *task);
  54 static void     call_bind(struct rpc_task *task);
  55 static void     call_bind_status(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_transmit_status(struct rpc_task *task);
  59 static void     call_refresh(struct rpc_task *task);
  60 static void     call_refreshresult(struct rpc_task *task);
  61 static void     call_timeout(struct rpc_task *task);
  62 static void     call_connect(struct rpc_task *task);
  63 static void     call_connect_status(struct rpc_task *task);
  64 static u32 *    call_header(struct rpc_task *task);
  65 static u32 *    call_verify(struct rpc_task *task);
  66
  67
  68 static int
  69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  70 {
  71         static uint32_t clntid;
  72         int error;
  73
  74         if (dir_name == NULL)
  75                 return 0;
  76         for (;;) {
  77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  78                                 "%s/clnt%x", dir_name,
  79                                 (unsigned int)clntid++);
  80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  82                 if (!IS_ERR(clnt->cl_dentry))
  83                         return 0;
  84                 error = PTR_ERR(clnt->cl_dentry);
  85                 if (error != -EEXIST) {
  86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  87                                         clnt->cl_pathname, error);
  88                         return error;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Create an RPC client
  95  * FIXME: This should also take a flags argument (as in task->tk_flags).
  96  * It's called (among others) from pmap_create_client, which may in
  97  * turn be called by an async task. In this case, rpciod should not be
  98  * made to sleep too long.
  99  */
 100 struct rpc_clnt *
 101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 102                   struct rpc_program *program, u32 vers,
 103                   rpc_authflavor_t flavor)
 104 {
 105         struct rpc_version      *version;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct rpc_auth         *auth;
 108         int err;
 109         int len;
 110
 111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 112                 program->name, servname, xprt);
 113
 114         err = -EINVAL;
 115         if (!xprt)
 116                 goto out_err;
 117         if (vers >= program->nrvers || !(version = program->version[vers]))
 118                 goto out_err;
 119
 120         err = -ENOMEM;
 121         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 122         if (!clnt)
 123                 goto out_err;
 124         memset(clnt, 0, sizeof(*clnt));
 125         atomic_set(&clnt->cl_users, 0);
 126         atomic_set(&clnt->cl_count, 1);
 127         clnt->cl_parent = clnt;
 128
 129         clnt->cl_server = clnt->cl_inline_name;
 130         len = strlen(servname) + 1;
 131         if (len > sizeof(clnt->cl_inline_name)) {
 132                 char *buf = kmalloc(len, GFP_KERNEL);
 133                 if (buf != 0)
 134                         clnt->cl_server = buf;
 135                 else
 136                         len = sizeof(clnt->cl_inline_name);
 137         }
 138         strlcpy(clnt->cl_server, servname, len);
 139
 140         clnt->cl_xprt     = xprt;
 141         clnt->cl_procinfo = version->procs;
 142         clnt->cl_maxproc  = version->nrprocs;
 143         clnt->cl_protname = program->name;
 144         clnt->cl_pmap     = &clnt->cl_pmap_default;
 145         clnt->cl_port     = xprt->addr.sin_port;
 146         clnt->cl_prog     = program->number;
 147         clnt->cl_vers     = version->number;
 148         clnt->cl_prot     = xprt->prot;
 149         clnt->cl_stats    = program->stats;
 150         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 151
 152         if (!clnt->cl_port)
 153                 clnt->cl_autobind = 1;
 154
 155         clnt->cl_rtt = &clnt->cl_rtt_default;
 156         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 157
 158         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 159         if (err < 0)
 160                 goto out_no_path;
 161
 162         auth = rpcauth_create(flavor, clnt);
 163         if (IS_ERR(auth)) {
 164                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 165                                 flavor);
 166                 err = PTR_ERR(auth);
 167                 goto out_no_auth;
 168         }
 169
 170         /* save the nodename */
 171         clnt->cl_nodelen = strlen(system_utsname.nodename);
 172         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 173                 clnt->cl_nodelen = UNX_MAXNODENAME;
 174         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 175         return clnt;
 176
 177 out_no_auth:
 178         rpc_rmdir(clnt->cl_pathname);
 179 out_no_path:
 180         if (clnt->cl_server != clnt->cl_inline_name)
 181                 kfree(clnt->cl_server);
 182         kfree(clnt);
 183 out_err:
 184         xprt_destroy(xprt);
 185         return ERR_PTR(err);
 186 }
 187
 188 /**
 189  * Create an RPC client
 190  * @xprt - pointer to xprt struct
 191  * @servname - name of server
 192  * @info - rpc_program
 193  * @version - rpc_program version
 194  * @authflavor - rpc_auth flavour to use
 195  *
 196  * Creates an RPC client structure, then pings the server in order to
 197  * determine if it is up, and if it supports this program and version.
 198  *
 199  * This function should never be called by asynchronous tasks such as
 200  * the portmapper.
 201  */
 202 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 203                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 204 {
 205         struct rpc_clnt *clnt;
 206         int err;
 207
 208         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 209         if (IS_ERR(clnt))
 210                 return clnt;
 211         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 212         if (err == 0)
 213                 return clnt;
 214         rpc_shutdown_client(clnt);
 215         return ERR_PTR(err);
 216 }
 217
 218 /*
 219  * This function clones the RPC client structure. It allows us to share the
 220  * same transport while varying parameters such as the authentication
 221  * flavour.
 222  */
 223 struct rpc_clnt *
 224 rpc_clone_client(struct rpc_clnt *clnt)
 225 {
 226         struct rpc_clnt *new;
 227
 228         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
 229         if (!new)
 230                 goto out_no_clnt;
 231         memcpy(new, clnt, sizeof(*new));
 232         atomic_set(&new->cl_count, 1);
 233         atomic_set(&new->cl_users, 0);
 234         new->cl_parent = clnt;
 235         atomic_inc(&clnt->cl_count);
 236         /* Duplicate portmapper */
 237         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 238         /* Turn off autobind on clones */
 239         new->cl_autobind = 0;
 240         new->cl_oneshot = 0;
 241         new->cl_dead = 0;
 242         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 243         if (new->cl_auth)
 244                 atomic_inc(&new->cl_auth->au_count);
 245         new->cl_pmap            = &new->cl_pmap_default;
 246         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 247         return new;
 248 out_no_clnt:
 249         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 250         return ERR_PTR(-ENOMEM);
 251 }
 252
 253 /*
 254  * Properly shut down an RPC client, terminating all outstanding
 255  * requests. Note that we must be certain that cl_oneshot and
 256  * cl_dead are cleared, or else the client would be destroyed
 257  * when the last task releases it.
 258  */
 259 int
 260 rpc_shutdown_client(struct rpc_clnt *clnt)
 261 {
 262         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 263                         clnt->cl_protname, clnt->cl_server,
 264                         atomic_read(&clnt->cl_users));
 265
 266         while (atomic_read(&clnt->cl_users) > 0) {
 267                 /* Don't let rpc_release_client destroy us */
 268                 clnt->cl_oneshot = 0;
 269                 clnt->cl_dead = 0;
 270                 rpc_killall_tasks(clnt);
 271                 sleep_on_timeout(&destroy_wait, 1*HZ);
 272         }
 273
 274         if (atomic_read(&clnt->cl_users) < 0) {
 275                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 276                                 clnt, atomic_read(&clnt->cl_users));
 277 #ifdef RPC_DEBUG
 278                 rpc_show_tasks();
 279 #endif
 280                 BUG();
 281         }
 282
 283         return rpc_destroy_client(clnt);
 284 }
 285
 286 /*
 287  * Delete an RPC client
 288  */
 289 int
 290 rpc_destroy_client(struct rpc_clnt *clnt)
 291 {
 292         if (!atomic_dec_and_test(&clnt->cl_count))
 293                 return 1;
 294         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 295
 296         dprintk("RPC: destroying %s client for %s\n",
 297                         clnt->cl_protname, clnt->cl_server);
 298         if (clnt->cl_auth) {
 299                 rpcauth_destroy(clnt->cl_auth);
 300                 clnt->cl_auth = NULL;
 301         }
 302         if (clnt->cl_parent != clnt) {
 303                 rpc_destroy_client(clnt->cl_parent);
 304                 goto out_free;
 305         }
 306         if (clnt->cl_pathname[0])
 307                 rpc_rmdir(clnt->cl_pathname);
 308         if (clnt->cl_xprt) {
 309                 xprt_destroy(clnt->cl_xprt);
 310                 clnt->cl_xprt = NULL;
 311         }
 312         if (clnt->cl_server != clnt->cl_inline_name)
 313                 kfree(clnt->cl_server);
 314 out_free:
 315         kfree(clnt);
 316         return 0;
 317 }
 318
 319 /*
 320  * Release an RPC client
 321  */
 322 void
 323 rpc_release_client(struct rpc_clnt *clnt)
 324 {
 325         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 326                                 clnt, atomic_read(&clnt->cl_users));
 327
 328         if (!atomic_dec_and_test(&clnt->cl_users))
 329                 return;
 330         wake_up(&destroy_wait);
 331         if (clnt->cl_oneshot || clnt->cl_dead)
 332                 rpc_destroy_client(clnt);
 333 }
 334
 335 /**
 336  * rpc_bind_new_program - bind a new RPC program to an existing client
 337  * @old - old rpc_client
 338  * @program - rpc program to set
 339  * @vers - rpc program version
 340  *
 341  * Clones the rpc client and sets up a new RPC program. This is mainly
 342  * of use for enabling different RPC programs to share the same transport.
 343  * The Sun NFSv2/v3 ACL protocol can do this.
 344  */
 345 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 346                                       struct rpc_program *program,
 347                                       int vers)
 348 {
 349         struct rpc_clnt *clnt;
 350         struct rpc_version *version;
 351         int err;
 352
 353         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 354         version = program->version[vers];
 355         clnt = rpc_clone_client(old);
 356         if (IS_ERR(clnt))
 357                 goto out;
 358         clnt->cl_procinfo = version->procs;
 359         clnt->cl_maxproc  = version->nrprocs;
 360         clnt->cl_protname = program->name;
 361         clnt->cl_prog     = program->number;
 362         clnt->cl_vers     = version->number;
 363         clnt->cl_stats    = program->stats;
 364         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 365         if (err != 0) {
 366                 rpc_shutdown_client(clnt);
 367                 clnt = ERR_PTR(err);
 368         }
 369 out:
 370         return clnt;
 371 }
 372
 373 /*
 374  * Default callback for async RPC calls
 375  */
 376 static void
 377 rpc_default_callback(struct rpc_task *task)
 378 {
 379 }
 380
 381 /*
 382  *      Export the signal mask handling for synchronous code that
 383  *      sleeps on RPC calls
 384  */
 385 #define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
 386
 387 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 388 {
 389         unsigned long   sigallow = 0;
 390         sigset_t sigmask;
 391
 392         /* Block all signals except those listed in sigallow */
 393         if (intr)
 394                 sigallow |= RPC_INTR_SIGNALS;
 395         siginitsetinv(&sigmask, sigallow);
 396         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 397 }
 398
 399 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 400 {
 401         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 402 }
 403
 404 static inline void rpc_restore_sigmask(sigset_t *oldset)
 405 {
 406         sigprocmask(SIG_SETMASK, oldset, NULL);
 407 }
 408
 409 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 410 {
 411         rpc_save_sigmask(oldset, clnt->cl_intr);
 412 }
 413
 414 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 415 {
 416         rpc_restore_sigmask(oldset);
 417 }
 418
 419 /*
 420  * New rpc_call implementation
 421  */
 422 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 423 {
 424         struct rpc_task *task;
 425         sigset_t        oldset;
 426         int             status;
 427
 428         /* If this client is slain all further I/O fails */
 429         if (clnt->cl_dead)
 430                 return -EIO;
 431
 432         BUG_ON(flags & RPC_TASK_ASYNC);
 433
 434         status = -ENOMEM;
 435         task = rpc_new_task(clnt, NULL, flags);
 436         if (task == NULL)
 437                 goto out;
 438
 439         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 440         rpc_task_sigmask(task, &oldset);
 441
 442         rpc_call_setup(task, msg, 0);
 443
 444         /* Set up the call info struct and execute the task */
 445         if (task->tk_status == 0) {
 446                 status = rpc_execute(task);
 447         } else {
 448                 status = task->tk_status;
 449                 rpc_release_task(task);
 450         }
 451
 452         rpc_restore_sigmask(&oldset);
 453 out:
 454         return status;
 455 }
 456
 457 /*
 458  * New rpc_call implementation
 459  */
 460 int
 461 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 462                rpc_action callback, void *data)
 463 {
 464         struct rpc_task *task;
 465         sigset_t        oldset;
 466         int             status;
 467
 468         /* If this client is slain all further I/O fails */
 469         if (clnt->cl_dead)
 470                 return -EIO;
 471
 472         flags |= RPC_TASK_ASYNC;
 473
 474         /* Create/initialize a new RPC task */
 475         if (!callback)
 476                 callback = rpc_default_callback;
 477         status = -ENOMEM;
 478         if (!(task = rpc_new_task(clnt, callback, flags)))
 479                 goto out;
 480         task->tk_calldata = data;
 481
 482         /* Mask signals on GSS_AUTH upcalls */
 483         rpc_task_sigmask(task, &oldset);
 484
 485         rpc_call_setup(task, msg, 0);
 486
 487         /* Set up the call info struct and execute the task */
 488         status = task->tk_status;
 489         if (status == 0)
 490                 rpc_execute(task);
 491         else
 492                 rpc_release_task(task);
 493
 494         rpc_restore_sigmask(&oldset);
 495 out:
 496         return status;
 497 }
 498
 499
 500 void
 501 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 502 {
 503         task->tk_msg   = *msg;
 504         task->tk_flags |= flags;
 505         /* Bind the user cred */
 506         if (task->tk_msg.rpc_cred != NULL)
 507                 rpcauth_holdcred(task);
 508         else
 509                 rpcauth_bindcred(task);
 510
 511         if (task->tk_status == 0)
 512                 task->tk_action = call_start;
 513         else
 514                 task->tk_action = NULL;
 515 }
 516
 517 void
 518 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 519 {
 520         struct rpc_xprt *xprt = clnt->cl_xprt;
 521         if (xprt->ops->set_buffer_size)
 522                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 523 }
 524
 525 /*
 526  * Return size of largest payload RPC client can support, in bytes
 527  *
 528  * For stream transports, this is one RPC record fragment (see RFC
 529  * 1831), as we don't support multi-record requests yet.  For datagram
 530  * transports, this is the size of an IP packet minus the IP, UDP, and
 531  * RPC header sizes.
 532  */
 533 size_t rpc_max_payload(struct rpc_clnt *clnt)
 534 {
 535         return clnt->cl_xprt->max_payload;
 536 }
 537 EXPORT_SYMBOL(rpc_max_payload);
 538
 539 /*
 540  * Restart an (async) RPC call. Usually called from within the
 541  * exit handler.
 542  */
 543 void
 544 rpc_restart_call(struct rpc_task *task)
 545 {
 546         if (RPC_ASSASSINATED(task))
 547                 return;
 548
 549         task->tk_action = call_start;
 550 }
 551
 552 /*
 553  * 0.  Initial state
 554  *
 555  *     Other FSM states can be visited zero or more times, but
 556  *     this state is visited exactly once for each RPC.
 557  */
 558 static void
 559 call_start(struct rpc_task *task)
 560 {
 561         struct rpc_clnt *clnt = task->tk_client;
 562
 563         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 564                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 565                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 566
 567         /* Increment call count */
 568         task->tk_msg.rpc_proc->p_count++;
 569         clnt->cl_stats->rpccnt++;
 570         task->tk_action = call_reserve;
 571 }
 572
 573 /*
 574  * 1.   Reserve an RPC call slot
 575  */
 576 static void
 577 call_reserve(struct rpc_task *task)
 578 {
 579         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 580
 581         if (!rpcauth_uptodatecred(task)) {
 582                 task->tk_action = call_refresh;
 583                 return;
 584         }
 585
 586         task->tk_status  = 0;
 587         task->tk_action  = call_reserveresult;
 588         xprt_reserve(task);
 589 }
 590
 591 /*
 592  * 1b.  Grok the result of xprt_reserve()
 593  */
 594 static void
 595 call_reserveresult(struct rpc_task *task)
 596 {
 597         int status = task->tk_status;
 598
 599         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 600                                 task->tk_pid, task->tk_status);
 601
 602         /*
 603          * After a call to xprt_reserve(), we must have either
 604          * a request slot or else an error status.
 605          */
 606         task->tk_status = 0;
 607         if (status >= 0) {
 608                 if (task->tk_rqstp) {
 609                         task->tk_action = call_allocate;
 610                         return;
 611                 }
 612
 613                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 614                                 __FUNCTION__, status);
 615                 rpc_exit(task, -EIO);
 616                 return;
 617         }
 618
 619         /*
 620          * Even though there was an error, we may have acquired
 621          * a request slot somehow.  Make sure not to leak it.
 622          */
 623         if (task->tk_rqstp) {
 624                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 625                                 __FUNCTION__, status);
 626                 xprt_release(task);
 627         }
 628
 629         switch (status) {
 630         case -EAGAIN:   /* woken up; retry */
 631                 task->tk_action = call_reserve;
 632                 return;
 633         case -EIO:      /* probably a shutdown */
 634                 break;
 635         default:
 636                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 637                                 __FUNCTION__, status);
 638                 break;
 639         }
 640         rpc_exit(task, status);
 641 }
 642
 643 /*
 644  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 645  *      (Note: buffer memory is freed in rpc_task_release).
 646  */
 647 static void
 648 call_allocate(struct rpc_task *task)
 649 {
 650         unsigned int    bufsiz;
 651
 652         dprintk("RPC: %4d call_allocate (status %d)\n",
 653                                 task->tk_pid, task->tk_status);
 654         task->tk_action = call_bind;
 655         if (task->tk_buffer)
 656                 return;
 657
 658         /* FIXME: compute buffer requirements more exactly using
 659          * auth->au_wslack */
 660         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 661
 662         if (rpc_malloc(task, bufsiz << 1) != NULL)
 663                 return;
 664         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 665
 666         if (RPC_IS_ASYNC(task) || !signalled()) {
 667                 xprt_release(task);
 668                 task->tk_action = call_reserve;
 669                 rpc_delay(task, HZ>>4);
 670                 return;
 671         }
 672
 673         rpc_exit(task, -ERESTARTSYS);
 674 }
 675
 676 static inline int
 677 rpc_task_need_encode(struct rpc_task *task)
 678 {
 679         return task->tk_rqstp->rq_snd_buf.len == 0;
 680 }
 681
 682 static inline void
 683 rpc_task_force_reencode(struct rpc_task *task)
 684 {
 685         task->tk_rqstp->rq_snd_buf.len = 0;
 686 }
 687
 688 /*
 689  * 3.   Encode arguments of an RPC call
 690  */
 691 static void
 692 call_encode(struct rpc_task *task)
 693 {
 694         struct rpc_rqst *req = task->tk_rqstp;
 695         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 696         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 697         unsigned int    bufsiz;
 698         kxdrproc_t      encode;
 699         u32             *p;
 700
 701         dprintk("RPC: %4d call_encode (status %d)\n",
 702                                 task->tk_pid, task->tk_status);
 703
 704         /* Default buffer setup */
 705         bufsiz = task->tk_bufsize >> 1;
 706         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 707         sndbuf->head[0].iov_len  = bufsiz;
 708         sndbuf->tail[0].iov_len  = 0;
 709         sndbuf->page_len         = 0;
 710         sndbuf->len              = 0;
 711         sndbuf->buflen           = bufsiz;
 712         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 713         rcvbuf->head[0].iov_len  = bufsiz;
 714         rcvbuf->tail[0].iov_len  = 0;
 715         rcvbuf->page_len         = 0;
 716         rcvbuf->len              = 0;
 717         rcvbuf->buflen           = bufsiz;
 718
 719         /* Encode header and provided arguments */
 720         encode = task->tk_msg.rpc_proc->p_encode;
 721         if (!(p = call_header(task))) {
 722                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 723                 rpc_exit(task, -EIO);
 724                 return;
 725         }
 726         if (encode == NULL)
 727                 return;
 728
 729         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 730                         task->tk_msg.rpc_argp);
 731         if (task->tk_status == -ENOMEM) {
 732                 /* XXX: Is this sane? */
 733                 rpc_delay(task, 3*HZ);
 734                 task->tk_status = -EAGAIN;
 735         }
 736 }
 737
 738 /*
 739  * 4.   Get the server port number if not yet set
 740  */
 741 static void
 742 call_bind(struct rpc_task *task)
 743 {
 744         struct rpc_clnt *clnt = task->tk_client;
 745
 746         dprintk("RPC: %4d call_bind (status %d)\n",
 747                                 task->tk_pid, task->tk_status);
 748
 749         task->tk_action = call_connect;
 750         if (!clnt->cl_port) {
 751                 task->tk_action = call_bind_status;
 752                 task->tk_timeout = task->tk_xprt->bind_timeout;
 753                 rpc_getport(task, clnt);
 754         }
 755 }
 756
 757 /*
 758  * 4a.  Sort out bind result
 759  */
 760 static void
 761 call_bind_status(struct rpc_task *task)
 762 {
 763         int status = -EACCES;
 764
 765         if (task->tk_status >= 0) {
 766                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 767                                         task->tk_pid, task->tk_status);
 768                 task->tk_status = 0;
 769                 task->tk_action = call_connect;
 770                 return;
 771         }
 772
 773         switch (task->tk_status) {
 774         case -EACCES:
 775                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 776                                 task->tk_pid);
 777                 rpc_delay(task, 3*HZ);
 778                 goto retry_bind;
 779         case -ETIMEDOUT:
 780                 dprintk("RPC: %4d rpcbind request timed out\n",
 781                                 task->tk_pid);
 782                 if (RPC_IS_SOFT(task)) {
 783                         status = -EIO;
 784                         break;
 785                 }
 786                 goto retry_bind;
 787         case -EPFNOSUPPORT:
 788                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 789                                 task->tk_pid);
 790                 break;
 791         case -EPROTONOSUPPORT:
 792                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 793                                 task->tk_pid);
 794                 break;
 795         default:
 796                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 797                                 task->tk_pid, -task->tk_status);
 798                 status = -EIO;
 799                 break;
 800         }
 801
 802         rpc_exit(task, status);
 803         return;
 804
 805 retry_bind:
 806         task->tk_status = 0;
 807         task->tk_action = call_bind;
 808         return;
 809 }
 810
 811 /*
 812  * 4b.  Connect to the RPC server
 813  */
 814 static void
 815 call_connect(struct rpc_task *task)
 816 {
 817         struct rpc_xprt *xprt = task->tk_xprt;
 818
 819         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 820                         task->tk_pid, xprt,
 821                         (xprt_connected(xprt) ? "is" : "is not"));
 822
 823         task->tk_action = call_transmit;
 824         if (!xprt_connected(xprt)) {
 825                 task->tk_action = call_connect_status;
 826                 if (task->tk_status < 0)
 827                         return;
 828                 xprt_connect(task);
 829         }
 830 }
 831
 832 /*
 833  * 4c.  Sort out connect result
 834  */
 835 static void
 836 call_connect_status(struct rpc_task *task)
 837 {
 838         struct rpc_clnt *clnt = task->tk_client;
 839         int status = task->tk_status;
 840
 841         dprintk("RPC: %5u call_connect_status (status %d)\n",
 842                                 task->tk_pid, task->tk_status);
 843
 844         task->tk_status = 0;
 845         if (status >= 0) {
 846                 clnt->cl_stats->netreconn++;
 847                 task->tk_action = call_transmit;
 848                 return;
 849         }
 850
 851         /* Something failed: remote service port may have changed */
 852         if (clnt->cl_autobind)
 853                 clnt->cl_port = 0;
 854
 855         switch (status) {
 856         case -ENOTCONN:
 857         case -ETIMEDOUT:
 858         case -EAGAIN:
 859                 task->tk_action = call_bind;
 860                 break;
 861         default:
 862                 rpc_exit(task, -EIO);
 863                 break;
 864         }
 865 }
 866
 867 /*
 868  * 5.   Transmit the RPC request, and wait for reply
 869  */
 870 static void
 871 call_transmit(struct rpc_task *task)
 872 {
 873         dprintk("RPC: %4d call_transmit (status %d)\n",
 874                                 task->tk_pid, task->tk_status);
 875
 876         task->tk_action = call_status;
 877         if (task->tk_status < 0)
 878                 return;
 879         task->tk_status = xprt_prepare_transmit(task);
 880         if (task->tk_status != 0)
 881                 return;
 882         /* Encode here so that rpcsec_gss can use correct sequence number. */
 883         if (rpc_task_need_encode(task)) {
 884                 task->tk_rqstp->rq_bytes_sent = 0;
 885                 call_encode(task);
 886                 /* Did the encode result in an error condition? */
 887                 if (task->tk_status != 0)
 888                         goto out_nosend;
 889         }
 890         task->tk_action = call_transmit_status;
 891         xprt_transmit(task);
 892         if (task->tk_status < 0)
 893                 return;
 894         if (!task->tk_msg.rpc_proc->p_decode) {
 895                 task->tk_action = NULL;
 896                 rpc_wake_up_task(task);
 897         }
 898         return;
 899 out_nosend:
 900         /* release socket write lock before attempting to handle error */
 901         xprt_abort_transmit(task);
 902         rpc_task_force_reencode(task);
 903 }
 904
 905 /*
 906  * 6.   Sort out the RPC call status
 907  */
 908 static void
 909 call_status(struct rpc_task *task)
 910 {
 911         struct rpc_clnt *clnt = task->tk_client;
 912         struct rpc_rqst *req = task->tk_rqstp;
 913         int             status;
 914
 915         if (req->rq_received > 0 && !req->rq_bytes_sent)
 916                 task->tk_status = req->rq_received;
 917
 918         dprintk("RPC: %4d call_status (status %d)\n",
 919                                 task->tk_pid, task->tk_status);
 920
 921         status = task->tk_status;
 922         if (status >= 0) {
 923                 task->tk_action = call_decode;
 924                 return;
 925         }
 926
 927         task->tk_status = 0;
 928         switch(status) {
 929         case -ETIMEDOUT:
 930                 task->tk_action = call_timeout;
 931                 break;
 932         case -ECONNREFUSED:
 933         case -ENOTCONN:
 934                 if (clnt->cl_autobind)
 935                         clnt->cl_port = 0;
 936                 task->tk_action = call_bind;
 937                 break;
 938         case -EAGAIN:
 939                 task->tk_action = call_transmit;
 940                 break;
 941         case -EIO:
 942                 /* shutdown or soft timeout */
 943                 rpc_exit(task, status);
 944                 break;
 945         default:
 946                 if (clnt->cl_chatty)
 947                         printk("%s: RPC call returned error %d\n",
 948                                clnt->cl_protname, -status);
 949                 rpc_exit(task, status);
 950                 break;
 951         }
 952 }
 953
 954 /*
 955  * 6a.  Handle transmission errors.
 956  */
 957 static void
 958 call_transmit_status(struct rpc_task *task)
 959 {
 960         if (task->tk_status != -EAGAIN)
 961                 rpc_task_force_reencode(task);
 962         call_status(task);
 963 }
 964
 965 /*
 966  * 6b.  Handle RPC timeout
 967  *      We do not release the request slot, so we keep using the
 968  *      same XID for all retransmits.
 969  */
 970 static void
 971 call_timeout(struct rpc_task *task)
 972 {
 973         struct rpc_clnt *clnt = task->tk_client;
 974
 975         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 976                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 977                 goto retry;
 978         }
 979
 980         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 981         if (RPC_IS_SOFT(task)) {
 982                 if (clnt->cl_chatty)
 983                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 984                                 clnt->cl_protname, clnt->cl_server);
 985                 rpc_exit(task, -EIO);
 986                 return;
 987         }
 988
 989         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 990                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 991                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 992                         clnt->cl_protname, clnt->cl_server);
 993         }
 994         if (clnt->cl_autobind)
 995                 clnt->cl_port = 0;
 996
 997 retry:
 998         clnt->cl_stats->rpcretrans++;
 999         task->tk_action = call_bind;
1000         task->tk_status = 0;
1001 }
1002
1003 /*
1004  * 7.   Decode the RPC reply
1005  */
1006 static void
1007 call_decode(struct rpc_task *task)
1008 {
1009         struct rpc_clnt *clnt = task->tk_client;
1010         struct rpc_rqst *req = task->tk_rqstp;
1011         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1012         u32             *p;
1013
1014         dprintk("RPC: %4d call_decode (status %d)\n",
1015                                 task->tk_pid, task->tk_status);
1016
1017         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
1018                 printk(KERN_NOTICE "%s: server %s OK\n",
1019                         clnt->cl_protname, clnt->cl_server);
1020                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1021         }
1022
1023         if (task->tk_status < 12) {
1024                 if (!RPC_IS_SOFT(task)) {
1025                         task->tk_action = call_bind;
1026                         clnt->cl_stats->rpcretrans++;
1027                         goto out_retry;
1028                 }
1029                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1030                         clnt->cl_protname, task->tk_status);
1031                 rpc_exit(task, -EIO);
1032                 return;
1033         }
1034
1035         req->rq_rcv_buf.len = req->rq_private_buf.len;
1036
1037         /* Check that the softirq receive buffer is valid */
1038         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1039                                 sizeof(req->rq_rcv_buf)) != 0);
1040
1041         /* Verify the RPC header */
1042         if (!(p = call_verify(task))) {
1043                 if (task->tk_action == NULL)
1044                         return;
1045                 goto out_retry;
1046         }
1047
1048         task->tk_action = NULL;
1049
1050         if (decode)
1051                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1052                                                       task->tk_msg.rpc_resp);
1053         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1054                                         task->tk_status);
1055         return;
1056 out_retry:
1057         req->rq_received = req->rq_private_buf.len = 0;
1058         task->tk_status = 0;
1059 }
1060
1061 /*
1062  * 8.   Refresh the credentials if rejected by the server
1063  */
1064 static void
1065 call_refresh(struct rpc_task *task)
1066 {
1067         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1068
1069         xprt_release(task);     /* Must do to obtain new XID */
1070         task->tk_action = call_refreshresult;
1071         task->tk_status = 0;
1072         task->tk_client->cl_stats->rpcauthrefresh++;
1073         rpcauth_refreshcred(task);
1074 }
1075
1076 /*
1077  * 8a.  Process the results of a credential refresh
1078  */
1079 static void
1080 call_refreshresult(struct rpc_task *task)
1081 {
1082         int status = task->tk_status;
1083         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1084                                 task->tk_pid, task->tk_status);
1085
1086         task->tk_status = 0;
1087         task->tk_action = call_reserve;
1088         if (status >= 0 && rpcauth_uptodatecred(task))
1089                 return;
1090         if (status == -EACCES) {
1091                 rpc_exit(task, -EACCES);
1092                 return;
1093         }
1094         task->tk_action = call_refresh;
1095         if (status != -ETIMEDOUT)
1096                 rpc_delay(task, 3*HZ);
1097         return;
1098 }
1099
1100 /*
1101  * Call header serialization
1102  */
1103 static u32 *
1104 call_header(struct rpc_task *task)
1105 {
1106         struct rpc_clnt *clnt = task->tk_client;
1107         struct rpc_rqst *req = task->tk_rqstp;
1108         u32             *p = req->rq_svec[0].iov_base;
1109
1110         /* FIXME: check buffer size? */
1111
1112         p = xprt_skip_transport_header(task->tk_xprt, p);
1113         *p++ = req->rq_xid;             /* XID */
1114         *p++ = htonl(RPC_CALL);         /* CALL */
1115         *p++ = htonl(RPC_VERSION);      /* RPC version */
1116         *p++ = htonl(clnt->cl_prog);    /* program number */
1117         *p++ = htonl(clnt->cl_vers);    /* program version */
1118         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1119         p = rpcauth_marshcred(task, p);
1120         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1121         return p;
1122 }
1123
1124 /*
1125  * Reply header verification
1126  */
1127 static u32 *
1128 call_verify(struct rpc_task *task)
1129 {
1130         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1131         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1132         u32     *p = iov->iov_base, n;
1133         int error = -EACCES;
1134
1135         if ((len -= 3) < 0)
1136                 goto out_overflow;
1137         p += 1; /* skip XID */
1138
1139         if ((n = ntohl(*p++)) != RPC_REPLY) {
1140                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1141                 goto out_retry;
1142         }
1143         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1144                 if (--len < 0)
1145                         goto out_overflow;
1146                 switch ((n = ntohl(*p++))) {
1147                         case RPC_AUTH_ERROR:
1148                                 break;
1149                         case RPC_MISMATCH:
1150                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1151                                 error = -EPROTONOSUPPORT;
1152                                 goto out_err;
1153                         default:
1154                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1155                                 goto out_eio;
1156                 }
1157                 if (--len < 0)
1158                         goto out_overflow;
1159                 switch ((n = ntohl(*p++))) {
1160                 case RPC_AUTH_REJECTEDCRED:
1161                 case RPC_AUTH_REJECTEDVERF:
1162                 case RPCSEC_GSS_CREDPROBLEM:
1163                 case RPCSEC_GSS_CTXPROBLEM:
1164                         if (!task->tk_cred_retry)
1165                                 break;
1166                         task->tk_cred_retry--;
1167                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1168                                                         task->tk_pid);
1169                         rpcauth_invalcred(task);
1170                         task->tk_action = call_refresh;
1171                         return NULL;
1172                 case RPC_AUTH_BADCRED:
1173                 case RPC_AUTH_BADVERF:
1174                         /* possibly garbled cred/verf? */
1175                         if (!task->tk_garb_retry)
1176                                 break;
1177                         task->tk_garb_retry--;
1178                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1179                                                         task->tk_pid);
1180                         task->tk_action = call_bind;
1181                         return NULL;
1182                 case RPC_AUTH_TOOWEAK:
1183                         printk(KERN_NOTICE "call_verify: server requires stronger "
1184                                "authentication.\n");
1185                         break;
1186                 default:
1187                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1188                         error = -EIO;
1189                 }
1190                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1191                                                 task->tk_pid, n);
1192                 goto out_err;
1193         }
1194         if (!(p = rpcauth_checkverf(task, p))) {
1195                 printk(KERN_WARNING "call_verify: auth check failed\n");
1196                 goto out_retry;         /* bad verifier, retry */
1197         }
1198         len = p - (u32 *)iov->iov_base - 1;
1199         if (len < 0)
1200                 goto out_overflow;
1201         switch ((n = ntohl(*p++))) {
1202         case RPC_SUCCESS:
1203                 return p;
1204         case RPC_PROG_UNAVAIL:
1205                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1206                                 (unsigned int)task->tk_client->cl_prog,
1207                                 task->tk_client->cl_server);
1208                 error = -EPFNOSUPPORT;
1209                 goto out_err;
1210         case RPC_PROG_MISMATCH:
1211                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1212                                 (unsigned int)task->tk_client->cl_prog,
1213                                 (unsigned int)task->tk_client->cl_vers,
1214                                 task->tk_client->cl_server);
1215                 error = -EPROTONOSUPPORT;
1216                 goto out_err;
1217         case RPC_PROC_UNAVAIL:
1218                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1219                                 task->tk_msg.rpc_proc,
1220                                 task->tk_client->cl_prog,
1221                                 task->tk_client->cl_vers,
1222                                 task->tk_client->cl_server);
1223                 error = -EOPNOTSUPP;
1224                 goto out_err;
1225         case RPC_GARBAGE_ARGS:
1226                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1227                 break;                  /* retry */
1228         default:
1229                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1230                 /* Also retry */
1231         }
1232
1233 out_retry:
1234         task->tk_client->cl_stats->rpcgarbage++;
1235         if (task->tk_garb_retry) {
1236                 task->tk_garb_retry--;
1237                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1238                 task->tk_action = call_bind;
1239                 return NULL;
1240         }
1241         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1242 out_eio:
1243         error = -EIO;
1244 out_err:
1245         rpc_exit(task, error);
1246         return NULL;
1247 out_overflow:
1248         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1249         goto out_retry;
1250 }
1251
1252 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1253 {
1254         return 0;
1255 }
1256
1257 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1258 {
1259         return 0;
1260 }
1261
1262 static struct rpc_procinfo rpcproc_null = {
1263         .p_encode = rpcproc_encode_null,
1264         .p_decode = rpcproc_decode_null,
1265 };
1266
1267 int rpc_ping(struct rpc_clnt *clnt, int flags)
1268 {
1269         struct rpc_message msg = {
1270                 .rpc_proc = &rpcproc_null,
1271         };
1272         int err;
1273         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1274         err = rpc_call_sync(clnt, &msg, flags);
1275         put_rpccred(msg.rpc_cred);
1276         return err;
1277 }