net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/utsname.h>
  31
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35
  36 #include <linux/nfs.h>
  37
  38
  39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  40
  41 #ifdef RPC_DEBUG
  42 # define RPCDBG_FACILITY        RPCDBG_CALL
  43 #endif
  44
  45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  46
  47
  48 static void     call_start(struct rpc_task *task);
  49 static void     call_reserve(struct rpc_task *task);
  50 static void     call_reserveresult(struct rpc_task *task);
  51 static void     call_allocate(struct rpc_task *task);
  52 static void     call_encode(struct rpc_task *task);
  53 static void     call_decode(struct rpc_task *task);
  54 static void     call_bind(struct rpc_task *task);
  55 static void     call_bind_status(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_transmit_status(struct rpc_task *task);
  59 static void     call_refresh(struct rpc_task *task);
  60 static void     call_refreshresult(struct rpc_task *task);
  61 static void     call_timeout(struct rpc_task *task);
  62 static void     call_connect(struct rpc_task *task);
  63 static void     call_connect_status(struct rpc_task *task);
  64 static u32 *    call_header(struct rpc_task *task);
  65 static u32 *    call_verify(struct rpc_task *task);
  66
  67
  68 static int
  69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  70 {
  71         static uint32_t clntid;
  72         int error;
  73
  74         if (dir_name == NULL)
  75                 return 0;
  76         for (;;) {
  77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  78                                 "%s/clnt%x", dir_name,
  79                                 (unsigned int)clntid++);
  80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  82                 if (!IS_ERR(clnt->cl_dentry))
  83                         return 0;
  84                 error = PTR_ERR(clnt->cl_dentry);
  85                 if (error != -EEXIST) {
  86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  87                                         clnt->cl_pathname, error);
  88                         return error;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Create an RPC client
  95  * FIXME: This should also take a flags argument (as in task->tk_flags).
  96  * It's called (among others) from pmap_create_client, which may in
  97  * turn be called by an async task. In this case, rpciod should not be
  98  * made to sleep too long.
  99  */
 100 struct rpc_clnt *
 101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 102                   struct rpc_program *program, u32 vers,
 103                   rpc_authflavor_t flavor)
 104 {
 105         struct rpc_version      *version;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct rpc_auth         *auth;
 108         int err;
 109         int len;
 110
 111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 112                 program->name, servname, xprt);
 113
 114         err = -EINVAL;
 115         if (!xprt)
 116                 goto out_err;
 117         if (vers >= program->nrvers || !(version = program->version[vers]))
 118                 goto out_err;
 119
 120         err = -ENOMEM;
 121         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 122         if (!clnt)
 123                 goto out_err;
 124         memset(clnt, 0, sizeof(*clnt));
 125         atomic_set(&clnt->cl_users, 0);
 126         atomic_set(&clnt->cl_count, 1);
 127         clnt->cl_parent = clnt;
 128
 129         clnt->cl_server = clnt->cl_inline_name;
 130         len = strlen(servname) + 1;
 131         if (len > sizeof(clnt->cl_inline_name)) {
 132                 char *buf = kmalloc(len, GFP_KERNEL);
 133                 if (buf != 0)
 134                         clnt->cl_server = buf;
 135                 else
 136                         len = sizeof(clnt->cl_inline_name);
 137         }
 138         strlcpy(clnt->cl_server, servname, len);
 139
 140         clnt->cl_xprt     = xprt;
 141         clnt->cl_procinfo = version->procs;
 142         clnt->cl_maxproc  = version->nrprocs;
 143         clnt->cl_protname = program->name;
 144         clnt->cl_pmap     = &clnt->cl_pmap_default;
 145         clnt->cl_port     = xprt->addr.sin_port;
 146         clnt->cl_prog     = program->number;
 147         clnt->cl_vers     = version->number;
 148         clnt->cl_prot     = xprt->prot;
 149         clnt->cl_stats    = program->stats;
 150         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 151
 152         if (!clnt->cl_port)
 153                 clnt->cl_autobind = 1;
 154
 155         clnt->cl_rtt = &clnt->cl_rtt_default;
 156         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 157
 158         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 159         if (err < 0)
 160                 goto out_no_path;
 161
 162         auth = rpcauth_create(flavor, clnt);
 163         if (IS_ERR(auth)) {
 164                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 165                                 flavor);
 166                 err = PTR_ERR(auth);
 167                 goto out_no_auth;
 168         }
 169
 170         /* save the nodename */
 171         clnt->cl_nodelen = strlen(system_utsname.nodename);
 172         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 173                 clnt->cl_nodelen = UNX_MAXNODENAME;
 174         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 175         return clnt;
 176
 177 out_no_auth:
 178         rpc_rmdir(clnt->cl_pathname);
 179 out_no_path:
 180         if (clnt->cl_server != clnt->cl_inline_name)
 181                 kfree(clnt->cl_server);
 182         kfree(clnt);
 183 out_err:
 184         xprt_destroy(xprt);
 185         return ERR_PTR(err);
 186 }
 187
 188 /**
 189  * Create an RPC client
 190  * @xprt - pointer to xprt struct
 191  * @servname - name of server
 192  * @info - rpc_program
 193  * @version - rpc_program version
 194  * @authflavor - rpc_auth flavour to use
 195  *
 196  * Creates an RPC client structure, then pings the server in order to
 197  * determine if it is up, and if it supports this program and version.
 198  *
 199  * This function should never be called by asynchronous tasks such as
 200  * the portmapper.
 201  */
 202 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 203                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 204 {
 205         struct rpc_clnt *clnt;
 206         int err;
 207
 208         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 209         if (IS_ERR(clnt))
 210                 return clnt;
 211         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 212         if (err == 0)
 213                 return clnt;
 214         rpc_shutdown_client(clnt);
 215         return ERR_PTR(err);
 216 }
 217
 218 /*
 219  * This function clones the RPC client structure. It allows us to share the
 220  * same transport while varying parameters such as the authentication
 221  * flavour.
 222  */
 223 struct rpc_clnt *
 224 rpc_clone_client(struct rpc_clnt *clnt)
 225 {
 226         struct rpc_clnt *new;
 227
 228         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
 229         if (!new)
 230                 goto out_no_clnt;
 231         memcpy(new, clnt, sizeof(*new));
 232         atomic_set(&new->cl_count, 1);
 233         atomic_set(&new->cl_users, 0);
 234         new->cl_parent = clnt;
 235         atomic_inc(&clnt->cl_count);
 236         /* Duplicate portmapper */
 237         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 238         /* Turn off autobind on clones */
 239         new->cl_autobind = 0;
 240         new->cl_oneshot = 0;
 241         new->cl_dead = 0;
 242         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 243         if (new->cl_auth)
 244                 atomic_inc(&new->cl_auth->au_count);
 245         new->cl_pmap            = &new->cl_pmap_default;
 246         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 247         return new;
 248 out_no_clnt:
 249         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 250         return ERR_PTR(-ENOMEM);
 251 }
 252
 253 /*
 254  * Properly shut down an RPC client, terminating all outstanding
 255  * requests. Note that we must be certain that cl_oneshot and
 256  * cl_dead are cleared, or else the client would be destroyed
 257  * when the last task releases it.
 258  */
 259 int
 260 rpc_shutdown_client(struct rpc_clnt *clnt)
 261 {
 262         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 263                         clnt->cl_protname, clnt->cl_server,
 264                         atomic_read(&clnt->cl_users));
 265
 266         while (atomic_read(&clnt->cl_users) > 0) {
 267                 /* Don't let rpc_release_client destroy us */
 268                 clnt->cl_oneshot = 0;
 269                 clnt->cl_dead = 0;
 270                 rpc_killall_tasks(clnt);
 271                 sleep_on_timeout(&destroy_wait, 1*HZ);
 272         }
 273
 274         if (atomic_read(&clnt->cl_users) < 0) {
 275                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 276                                 clnt, atomic_read(&clnt->cl_users));
 277 #ifdef RPC_DEBUG
 278                 rpc_show_tasks();
 279 #endif
 280                 BUG();
 281         }
 282
 283         return rpc_destroy_client(clnt);
 284 }
 285
 286 /*
 287  * Delete an RPC client
 288  */
 289 int
 290 rpc_destroy_client(struct rpc_clnt *clnt)
 291 {
 292         if (!atomic_dec_and_test(&clnt->cl_count))
 293                 return 1;
 294         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 295
 296         dprintk("RPC: destroying %s client for %s\n",
 297                         clnt->cl_protname, clnt->cl_server);
 298         if (clnt->cl_auth) {
 299                 rpcauth_destroy(clnt->cl_auth);
 300                 clnt->cl_auth = NULL;
 301         }
 302         if (clnt->cl_parent != clnt) {
 303                 rpc_destroy_client(clnt->cl_parent);
 304                 goto out_free;
 305         }
 306         if (clnt->cl_pathname[0])
 307                 rpc_rmdir(clnt->cl_pathname);
 308         if (clnt->cl_xprt) {
 309                 xprt_destroy(clnt->cl_xprt);
 310                 clnt->cl_xprt = NULL;
 311         }
 312         if (clnt->cl_server != clnt->cl_inline_name)
 313                 kfree(clnt->cl_server);
 314 out_free:
 315         kfree(clnt);
 316         return 0;
 317 }
 318
 319 /*
 320  * Release an RPC client
 321  */
 322 void
 323 rpc_release_client(struct rpc_clnt *clnt)
 324 {
 325         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 326                                 clnt, atomic_read(&clnt->cl_users));
 327
 328         if (!atomic_dec_and_test(&clnt->cl_users))
 329                 return;
 330         wake_up(&destroy_wait);
 331         if (clnt->cl_oneshot || clnt->cl_dead)
 332                 rpc_destroy_client(clnt);
 333 }
 334
 335 /**
 336  * rpc_bind_new_program - bind a new RPC program to an existing client
 337  * @old - old rpc_client
 338  * @program - rpc program to set
 339  * @vers - rpc program version
 340  *
 341  * Clones the rpc client and sets up a new RPC program. This is mainly
 342  * of use for enabling different RPC programs to share the same transport.
 343  * The Sun NFSv2/v3 ACL protocol can do this.
 344  */
 345 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 346                                       struct rpc_program *program,
 347                                       int vers)
 348 {
 349         struct rpc_clnt *clnt;
 350         struct rpc_version *version;
 351         int err;
 352
 353         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 354         version = program->version[vers];
 355         clnt = rpc_clone_client(old);
 356         if (IS_ERR(clnt))
 357                 goto out;
 358         clnt->cl_procinfo = version->procs;
 359         clnt->cl_maxproc  = version->nrprocs;
 360         clnt->cl_protname = program->name;
 361         clnt->cl_prog     = program->number;
 362         clnt->cl_vers     = version->number;
 363         clnt->cl_stats    = program->stats;
 364         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 365         if (err != 0) {
 366                 rpc_shutdown_client(clnt);
 367                 clnt = ERR_PTR(err);
 368         }
 369 out:
 370         return clnt;
 371 }
 372
 373 /*
 374  * Default callback for async RPC calls
 375  */
 376 static void
 377 rpc_default_callback(struct rpc_task *task, void *data)
 378 {
 379 }
 380
 381 static const struct rpc_call_ops rpc_default_ops = {
 382         .rpc_call_done = rpc_default_callback,
 383 };
 384
 385 /*
 386  *      Export the signal mask handling for synchronous code that
 387  *      sleeps on RPC calls
 388  */
 389 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 390
 391 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 392 {
 393         unsigned long   sigallow = sigmask(SIGKILL);
 394         sigset_t sigmask;
 395
 396         /* Block all signals except those listed in sigallow */
 397         if (intr)
 398                 sigallow |= RPC_INTR_SIGNALS;
 399         siginitsetinv(&sigmask, sigallow);
 400         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 401 }
 402
 403 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 404 {
 405         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 406 }
 407
 408 static inline void rpc_restore_sigmask(sigset_t *oldset)
 409 {
 410         sigprocmask(SIG_SETMASK, oldset, NULL);
 411 }
 412
 413 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 414 {
 415         rpc_save_sigmask(oldset, clnt->cl_intr);
 416 }
 417
 418 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 419 {
 420         rpc_restore_sigmask(oldset);
 421 }
 422
 423 /*
 424  * New rpc_call implementation
 425  */
 426 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 427 {
 428         struct rpc_task *task;
 429         sigset_t        oldset;
 430         int             status;
 431
 432         /* If this client is slain all further I/O fails */
 433         if (clnt->cl_dead)
 434                 return -EIO;
 435
 436         BUG_ON(flags & RPC_TASK_ASYNC);
 437
 438         status = -ENOMEM;
 439         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 440         if (task == NULL)
 441                 goto out;
 442
 443         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 444         rpc_task_sigmask(task, &oldset);
 445
 446         rpc_call_setup(task, msg, 0);
 447
 448         /* Set up the call info struct and execute the task */
 449         status = task->tk_status;
 450         if (status == 0) {
 451                 atomic_inc(&task->tk_count);
 452                 status = rpc_execute(task);
 453                 if (status == 0)
 454                         status = task->tk_status;
 455         }
 456         rpc_restore_sigmask(&oldset);
 457         rpc_release_task(task);
 458 out:
 459         return status;
 460 }
 461
 462 /*
 463  * New rpc_call implementation
 464  */
 465 int
 466 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 467                const struct rpc_call_ops *tk_ops, void *data)
 468 {
 469         struct rpc_task *task;
 470         sigset_t        oldset;
 471         int             status;
 472
 473         /* If this client is slain all further I/O fails */
 474         if (clnt->cl_dead)
 475                 return -EIO;
 476
 477         flags |= RPC_TASK_ASYNC;
 478
 479         /* Create/initialize a new RPC task */
 480         status = -ENOMEM;
 481         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 482                 goto out;
 483
 484         /* Mask signals on GSS_AUTH upcalls */
 485         rpc_task_sigmask(task, &oldset);
 486
 487         rpc_call_setup(task, msg, 0);
 488
 489         /* Set up the call info struct and execute the task */
 490         status = task->tk_status;
 491         if (status == 0)
 492                 rpc_execute(task);
 493         else
 494                 rpc_release_task(task);
 495
 496         rpc_restore_sigmask(&oldset);
 497 out:
 498         return status;
 499 }
 500
 501
 502 void
 503 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 504 {
 505         task->tk_msg   = *msg;
 506         task->tk_flags |= flags;
 507         /* Bind the user cred */
 508         if (task->tk_msg.rpc_cred != NULL)
 509                 rpcauth_holdcred(task);
 510         else
 511                 rpcauth_bindcred(task);
 512
 513         if (task->tk_status == 0)
 514                 task->tk_action = call_start;
 515         else
 516                 task->tk_action = rpc_exit_task;
 517 }
 518
 519 void
 520 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 521 {
 522         struct rpc_xprt *xprt = clnt->cl_xprt;
 523         if (xprt->ops->set_buffer_size)
 524                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 525 }
 526
 527 /*
 528  * Return size of largest payload RPC client can support, in bytes
 529  *
 530  * For stream transports, this is one RPC record fragment (see RFC
 531  * 1831), as we don't support multi-record requests yet.  For datagram
 532  * transports, this is the size of an IP packet minus the IP, UDP, and
 533  * RPC header sizes.
 534  */
 535 size_t rpc_max_payload(struct rpc_clnt *clnt)
 536 {
 537         return clnt->cl_xprt->max_payload;
 538 }
 539 EXPORT_SYMBOL(rpc_max_payload);
 540
 541 /**
 542  * rpc_force_rebind - force transport to check that remote port is unchanged
 543  * @clnt: client to rebind
 544  *
 545  */
 546 void rpc_force_rebind(struct rpc_clnt *clnt)
 547 {
 548         if (clnt->cl_autobind)
 549                 clnt->cl_port = 0;
 550 }
 551 EXPORT_SYMBOL(rpc_force_rebind);
 552
 553 /*
 554  * Restart an (async) RPC call. Usually called from within the
 555  * exit handler.
 556  */
 557 void
 558 rpc_restart_call(struct rpc_task *task)
 559 {
 560         if (RPC_ASSASSINATED(task))
 561                 return;
 562
 563         task->tk_action = call_start;
 564 }
 565
 566 /*
 567  * 0.  Initial state
 568  *
 569  *     Other FSM states can be visited zero or more times, but
 570  *     this state is visited exactly once for each RPC.
 571  */
 572 static void
 573 call_start(struct rpc_task *task)
 574 {
 575         struct rpc_clnt *clnt = task->tk_client;
 576
 577         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 578                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 579                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 580
 581         /* Increment call count */
 582         task->tk_msg.rpc_proc->p_count++;
 583         clnt->cl_stats->rpccnt++;
 584         task->tk_action = call_reserve;
 585 }
 586
 587 /*
 588  * 1.   Reserve an RPC call slot
 589  */
 590 static void
 591 call_reserve(struct rpc_task *task)
 592 {
 593         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 594
 595         if (!rpcauth_uptodatecred(task)) {
 596                 task->tk_action = call_refresh;
 597                 return;
 598         }
 599
 600         task->tk_status  = 0;
 601         task->tk_action  = call_reserveresult;
 602         xprt_reserve(task);
 603 }
 604
 605 /*
 606  * 1b.  Grok the result of xprt_reserve()
 607  */
 608 static void
 609 call_reserveresult(struct rpc_task *task)
 610 {
 611         int status = task->tk_status;
 612
 613         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 614                                 task->tk_pid, task->tk_status);
 615
 616         /*
 617          * After a call to xprt_reserve(), we must have either
 618          * a request slot or else an error status.
 619          */
 620         task->tk_status = 0;
 621         if (status >= 0) {
 622                 if (task->tk_rqstp) {
 623                         task->tk_action = call_allocate;
 624                         return;
 625                 }
 626
 627                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 628                                 __FUNCTION__, status);
 629                 rpc_exit(task, -EIO);
 630                 return;
 631         }
 632
 633         /*
 634          * Even though there was an error, we may have acquired
 635          * a request slot somehow.  Make sure not to leak it.
 636          */
 637         if (task->tk_rqstp) {
 638                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 639                                 __FUNCTION__, status);
 640                 xprt_release(task);
 641         }
 642
 643         switch (status) {
 644         case -EAGAIN:   /* woken up; retry */
 645                 task->tk_action = call_reserve;
 646                 return;
 647         case -EIO:      /* probably a shutdown */
 648                 break;
 649         default:
 650                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 651                                 __FUNCTION__, status);
 652                 break;
 653         }
 654         rpc_exit(task, status);
 655 }
 656
 657 /*
 658  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 659  *      (Note: buffer memory is freed in xprt_release).
 660  */
 661 static void
 662 call_allocate(struct rpc_task *task)
 663 {
 664         struct rpc_rqst *req = task->tk_rqstp;
 665         struct rpc_xprt *xprt = task->tk_xprt;
 666         unsigned int    bufsiz;
 667
 668         dprintk("RPC: %4d call_allocate (status %d)\n",
 669                                 task->tk_pid, task->tk_status);
 670         task->tk_action = call_bind;
 671         if (req->rq_buffer)
 672                 return;
 673
 674         /* FIXME: compute buffer requirements more exactly using
 675          * auth->au_wslack */
 676         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 677
 678         if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
 679                 return;
 680         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 681
 682         if (RPC_IS_ASYNC(task) || !signalled()) {
 683                 xprt_release(task);
 684                 task->tk_action = call_reserve;
 685                 rpc_delay(task, HZ>>4);
 686                 return;
 687         }
 688
 689         rpc_exit(task, -ERESTARTSYS);
 690 }
 691
 692 static inline int
 693 rpc_task_need_encode(struct rpc_task *task)
 694 {
 695         return task->tk_rqstp->rq_snd_buf.len == 0;
 696 }
 697
 698 static inline void
 699 rpc_task_force_reencode(struct rpc_task *task)
 700 {
 701         task->tk_rqstp->rq_snd_buf.len = 0;
 702 }
 703
 704 /*
 705  * 3.   Encode arguments of an RPC call
 706  */
 707 static void
 708 call_encode(struct rpc_task *task)
 709 {
 710         struct rpc_rqst *req = task->tk_rqstp;
 711         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 712         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 713         unsigned int    bufsiz;
 714         kxdrproc_t      encode;
 715         u32             *p;
 716
 717         dprintk("RPC: %4d call_encode (status %d)\n",
 718                                 task->tk_pid, task->tk_status);
 719
 720         /* Default buffer setup */
 721         bufsiz = req->rq_bufsize >> 1;
 722         sndbuf->head[0].iov_base = (void *)req->rq_buffer;
 723         sndbuf->head[0].iov_len  = bufsiz;
 724         sndbuf->tail[0].iov_len  = 0;
 725         sndbuf->page_len         = 0;
 726         sndbuf->len              = 0;
 727         sndbuf->buflen           = bufsiz;
 728         rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
 729         rcvbuf->head[0].iov_len  = bufsiz;
 730         rcvbuf->tail[0].iov_len  = 0;
 731         rcvbuf->page_len         = 0;
 732         rcvbuf->len              = 0;
 733         rcvbuf->buflen           = bufsiz;
 734
 735         /* Encode header and provided arguments */
 736         encode = task->tk_msg.rpc_proc->p_encode;
 737         if (!(p = call_header(task))) {
 738                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 739                 rpc_exit(task, -EIO);
 740                 return;
 741         }
 742         if (encode == NULL)
 743                 return;
 744
 745         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 746                         task->tk_msg.rpc_argp);
 747         if (task->tk_status == -ENOMEM) {
 748                 /* XXX: Is this sane? */
 749                 rpc_delay(task, 3*HZ);
 750                 task->tk_status = -EAGAIN;
 751         }
 752 }
 753
 754 /*
 755  * 4.   Get the server port number if not yet set
 756  */
 757 static void
 758 call_bind(struct rpc_task *task)
 759 {
 760         struct rpc_clnt *clnt = task->tk_client;
 761
 762         dprintk("RPC: %4d call_bind (status %d)\n",
 763                                 task->tk_pid, task->tk_status);
 764
 765         task->tk_action = call_connect;
 766         if (!clnt->cl_port) {
 767                 task->tk_action = call_bind_status;
 768                 task->tk_timeout = task->tk_xprt->bind_timeout;
 769                 rpc_getport(task, clnt);
 770         }
 771 }
 772
 773 /*
 774  * 4a.  Sort out bind result
 775  */
 776 static void
 777 call_bind_status(struct rpc_task *task)
 778 {
 779         int status = -EACCES;
 780
 781         if (task->tk_status >= 0) {
 782                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 783                                         task->tk_pid, task->tk_status);
 784                 task->tk_status = 0;
 785                 task->tk_action = call_connect;
 786                 return;
 787         }
 788
 789         switch (task->tk_status) {
 790         case -EACCES:
 791                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 792                                 task->tk_pid);
 793                 rpc_delay(task, 3*HZ);
 794                 goto retry_bind;
 795         case -ETIMEDOUT:
 796                 dprintk("RPC: %4d rpcbind request timed out\n",
 797                                 task->tk_pid);
 798                 if (RPC_IS_SOFT(task)) {
 799                         status = -EIO;
 800                         break;
 801                 }
 802                 goto retry_bind;
 803         case -EPFNOSUPPORT:
 804                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 805                                 task->tk_pid);
 806                 break;
 807         case -EPROTONOSUPPORT:
 808                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 809                                 task->tk_pid);
 810                 break;
 811         default:
 812                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 813                                 task->tk_pid, -task->tk_status);
 814                 status = -EIO;
 815                 break;
 816         }
 817
 818         rpc_exit(task, status);
 819         return;
 820
 821 retry_bind:
 822         task->tk_status = 0;
 823         task->tk_action = call_bind;
 824         return;
 825 }
 826
 827 /*
 828  * 4b.  Connect to the RPC server
 829  */
 830 static void
 831 call_connect(struct rpc_task *task)
 832 {
 833         struct rpc_xprt *xprt = task->tk_xprt;
 834
 835         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 836                         task->tk_pid, xprt,
 837                         (xprt_connected(xprt) ? "is" : "is not"));
 838
 839         task->tk_action = call_transmit;
 840         if (!xprt_connected(xprt)) {
 841                 task->tk_action = call_connect_status;
 842                 if (task->tk_status < 0)
 843                         return;
 844                 xprt_connect(task);
 845         }
 846 }
 847
 848 /*
 849  * 4c.  Sort out connect result
 850  */
 851 static void
 852 call_connect_status(struct rpc_task *task)
 853 {
 854         struct rpc_clnt *clnt = task->tk_client;
 855         int status = task->tk_status;
 856
 857         dprintk("RPC: %5u call_connect_status (status %d)\n",
 858                                 task->tk_pid, task->tk_status);
 859
 860         task->tk_status = 0;
 861         if (status >= 0) {
 862                 clnt->cl_stats->netreconn++;
 863                 task->tk_action = call_transmit;
 864                 return;
 865         }
 866
 867         /* Something failed: remote service port may have changed */
 868         rpc_force_rebind(clnt);
 869
 870         switch (status) {
 871         case -ENOTCONN:
 872         case -ETIMEDOUT:
 873         case -EAGAIN:
 874                 task->tk_action = call_bind;
 875                 break;
 876         default:
 877                 rpc_exit(task, -EIO);
 878                 break;
 879         }
 880 }
 881
 882 /*
 883  * 5.   Transmit the RPC request, and wait for reply
 884  */
 885 static void
 886 call_transmit(struct rpc_task *task)
 887 {
 888         dprintk("RPC: %4d call_transmit (status %d)\n",
 889                                 task->tk_pid, task->tk_status);
 890
 891         task->tk_action = call_status;
 892         if (task->tk_status < 0)
 893                 return;
 894         task->tk_status = xprt_prepare_transmit(task);
 895         if (task->tk_status != 0)
 896                 return;
 897         /* Encode here so that rpcsec_gss can use correct sequence number. */
 898         if (rpc_task_need_encode(task)) {
 899                 task->tk_rqstp->rq_bytes_sent = 0;
 900                 call_encode(task);
 901                 /* Did the encode result in an error condition? */
 902                 if (task->tk_status != 0)
 903                         goto out_nosend;
 904         }
 905         task->tk_action = call_transmit_status;
 906         xprt_transmit(task);
 907         if (task->tk_status < 0)
 908                 return;
 909         if (!task->tk_msg.rpc_proc->p_decode) {
 910                 task->tk_action = rpc_exit_task;
 911                 rpc_wake_up_task(task);
 912         }
 913         return;
 914 out_nosend:
 915         /* release socket write lock before attempting to handle error */
 916         xprt_abort_transmit(task);
 917         rpc_task_force_reencode(task);
 918 }
 919
 920 /*
 921  * 6.   Sort out the RPC call status
 922  */
 923 static void
 924 call_status(struct rpc_task *task)
 925 {
 926         struct rpc_clnt *clnt = task->tk_client;
 927         struct rpc_rqst *req = task->tk_rqstp;
 928         int             status;
 929
 930         if (req->rq_received > 0 && !req->rq_bytes_sent)
 931                 task->tk_status = req->rq_received;
 932
 933         dprintk("RPC: %4d call_status (status %d)\n",
 934                                 task->tk_pid, task->tk_status);
 935
 936         status = task->tk_status;
 937         if (status >= 0) {
 938                 task->tk_action = call_decode;
 939                 return;
 940         }
 941
 942         task->tk_status = 0;
 943         switch(status) {
 944         case -ETIMEDOUT:
 945                 task->tk_action = call_timeout;
 946                 break;
 947         case -ECONNREFUSED:
 948         case -ENOTCONN:
 949                 rpc_force_rebind(clnt);
 950                 task->tk_action = call_bind;
 951                 break;
 952         case -EAGAIN:
 953                 task->tk_action = call_transmit;
 954                 break;
 955         case -EIO:
 956                 /* shutdown or soft timeout */
 957                 rpc_exit(task, status);
 958                 break;
 959         default:
 960                 printk("%s: RPC call returned error %d\n",
 961                                clnt->cl_protname, -status);
 962                 rpc_exit(task, status);
 963                 break;
 964         }
 965 }
 966
 967 /*
 968  * 6a.  Handle transmission errors.
 969  */
 970 static void
 971 call_transmit_status(struct rpc_task *task)
 972 {
 973         if (task->tk_status != -EAGAIN)
 974                 rpc_task_force_reencode(task);
 975         call_status(task);
 976 }
 977
 978 /*
 979  * 6b.  Handle RPC timeout
 980  *      We do not release the request slot, so we keep using the
 981  *      same XID for all retransmits.
 982  */
 983 static void
 984 call_timeout(struct rpc_task *task)
 985 {
 986         struct rpc_clnt *clnt = task->tk_client;
 987
 988         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 989                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 990                 goto retry;
 991         }
 992
 993         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 994         if (RPC_IS_SOFT(task)) {
 995                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 996                                 clnt->cl_protname, clnt->cl_server);
 997                 rpc_exit(task, -EIO);
 998                 return;
 999         }
1000
1001         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1002                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1003                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1004                         clnt->cl_protname, clnt->cl_server);
1005         }
1006         rpc_force_rebind(clnt);
1007
1008 retry:
1009         clnt->cl_stats->rpcretrans++;
1010         task->tk_action = call_bind;
1011         task->tk_status = 0;
1012 }
1013
1014 /*
1015  * 7.   Decode the RPC reply
1016  */
1017 static void
1018 call_decode(struct rpc_task *task)
1019 {
1020         struct rpc_clnt *clnt = task->tk_client;
1021         struct rpc_rqst *req = task->tk_rqstp;
1022         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1023         u32             *p;
1024
1025         dprintk("RPC: %4d call_decode (status %d)\n",
1026                                 task->tk_pid, task->tk_status);
1027
1028         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1029                 printk(KERN_NOTICE "%s: server %s OK\n",
1030                         clnt->cl_protname, clnt->cl_server);
1031                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1032         }
1033
1034         if (task->tk_status < 12) {
1035                 if (!RPC_IS_SOFT(task)) {
1036                         task->tk_action = call_bind;
1037                         clnt->cl_stats->rpcretrans++;
1038                         goto out_retry;
1039                 }
1040                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1041                         clnt->cl_protname, task->tk_status);
1042                 rpc_exit(task, -EIO);
1043                 return;
1044         }
1045
1046         req->rq_rcv_buf.len = req->rq_private_buf.len;
1047
1048         /* Check that the softirq receive buffer is valid */
1049         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1050                                 sizeof(req->rq_rcv_buf)) != 0);
1051
1052         /* Verify the RPC header */
1053         p = call_verify(task);
1054         if (IS_ERR(p)) {
1055                 if (p == ERR_PTR(-EAGAIN))
1056                         goto out_retry;
1057                 return;
1058         }
1059
1060         task->tk_action = rpc_exit_task;
1061
1062         if (decode)
1063                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1064                                                       task->tk_msg.rpc_resp);
1065         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1066                                         task->tk_status);
1067         return;
1068 out_retry:
1069         req->rq_received = req->rq_private_buf.len = 0;
1070         task->tk_status = 0;
1071 }
1072
1073 /*
1074  * 8.   Refresh the credentials if rejected by the server
1075  */
1076 static void
1077 call_refresh(struct rpc_task *task)
1078 {
1079         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1080
1081         xprt_release(task);     /* Must do to obtain new XID */
1082         task->tk_action = call_refreshresult;
1083         task->tk_status = 0;
1084         task->tk_client->cl_stats->rpcauthrefresh++;
1085         rpcauth_refreshcred(task);
1086 }
1087
1088 /*
1089  * 8a.  Process the results of a credential refresh
1090  */
1091 static void
1092 call_refreshresult(struct rpc_task *task)
1093 {
1094         int status = task->tk_status;
1095         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1096                                 task->tk_pid, task->tk_status);
1097
1098         task->tk_status = 0;
1099         task->tk_action = call_reserve;
1100         if (status >= 0 && rpcauth_uptodatecred(task))
1101                 return;
1102         if (status == -EACCES) {
1103                 rpc_exit(task, -EACCES);
1104                 return;
1105         }
1106         task->tk_action = call_refresh;
1107         if (status != -ETIMEDOUT)
1108                 rpc_delay(task, 3*HZ);
1109         return;
1110 }
1111
1112 /*
1113  * Call header serialization
1114  */
1115 static u32 *
1116 call_header(struct rpc_task *task)
1117 {
1118         struct rpc_clnt *clnt = task->tk_client;
1119         struct rpc_rqst *req = task->tk_rqstp;
1120         u32             *p = req->rq_svec[0].iov_base;
1121
1122         /* FIXME: check buffer size? */
1123
1124         p = xprt_skip_transport_header(task->tk_xprt, p);
1125         *p++ = req->rq_xid;             /* XID */
1126         *p++ = htonl(RPC_CALL);         /* CALL */
1127         *p++ = htonl(RPC_VERSION);      /* RPC version */
1128         *p++ = htonl(clnt->cl_prog);    /* program number */
1129         *p++ = htonl(clnt->cl_vers);    /* program version */
1130         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1131         p = rpcauth_marshcred(task, p);
1132         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1133         return p;
1134 }
1135
1136 /*
1137  * Reply header verification
1138  */
1139 static u32 *
1140 call_verify(struct rpc_task *task)
1141 {
1142         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1143         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1144         u32     *p = iov->iov_base, n;
1145         int error = -EACCES;
1146
1147         if ((len -= 3) < 0)
1148                 goto out_overflow;
1149         p += 1; /* skip XID */
1150
1151         if ((n = ntohl(*p++)) != RPC_REPLY) {
1152                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1153                 goto out_garbage;
1154         }
1155         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1156                 if (--len < 0)
1157                         goto out_overflow;
1158                 switch ((n = ntohl(*p++))) {
1159                         case RPC_AUTH_ERROR:
1160                                 break;
1161                         case RPC_MISMATCH:
1162                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1163                                 error = -EPROTONOSUPPORT;
1164                                 goto out_err;
1165                         default:
1166                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1167                                 goto out_eio;
1168                 }
1169                 if (--len < 0)
1170                         goto out_overflow;
1171                 switch ((n = ntohl(*p++))) {
1172                 case RPC_AUTH_REJECTEDCRED:
1173                 case RPC_AUTH_REJECTEDVERF:
1174                 case RPCSEC_GSS_CREDPROBLEM:
1175                 case RPCSEC_GSS_CTXPROBLEM:
1176                         if (!task->tk_cred_retry)
1177                                 break;
1178                         task->tk_cred_retry--;
1179                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1180                                                         task->tk_pid);
1181                         rpcauth_invalcred(task);
1182                         task->tk_action = call_refresh;
1183                         goto out_retry;
1184                 case RPC_AUTH_BADCRED:
1185                 case RPC_AUTH_BADVERF:
1186                         /* possibly garbled cred/verf? */
1187                         if (!task->tk_garb_retry)
1188                                 break;
1189                         task->tk_garb_retry--;
1190                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1191                                                         task->tk_pid);
1192                         task->tk_action = call_bind;
1193                         goto out_retry;
1194                 case RPC_AUTH_TOOWEAK:
1195                         printk(KERN_NOTICE "call_verify: server requires stronger "
1196                                "authentication.\n");
1197                         break;
1198                 default:
1199                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1200                         error = -EIO;
1201                 }
1202                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1203                                                 task->tk_pid, n);
1204                 goto out_err;
1205         }
1206         if (!(p = rpcauth_checkverf(task, p))) {
1207                 printk(KERN_WARNING "call_verify: auth check failed\n");
1208                 goto out_garbage;               /* bad verifier, retry */
1209         }
1210         len = p - (u32 *)iov->iov_base - 1;
1211         if (len < 0)
1212                 goto out_overflow;
1213         switch ((n = ntohl(*p++))) {
1214         case RPC_SUCCESS:
1215                 return p;
1216         case RPC_PROG_UNAVAIL:
1217                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1218                                 (unsigned int)task->tk_client->cl_prog,
1219                                 task->tk_client->cl_server);
1220                 error = -EPFNOSUPPORT;
1221                 goto out_err;
1222         case RPC_PROG_MISMATCH:
1223                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1224                                 (unsigned int)task->tk_client->cl_prog,
1225                                 (unsigned int)task->tk_client->cl_vers,
1226                                 task->tk_client->cl_server);
1227                 error = -EPROTONOSUPPORT;
1228                 goto out_err;
1229         case RPC_PROC_UNAVAIL:
1230                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1231                                 task->tk_msg.rpc_proc,
1232                                 task->tk_client->cl_prog,
1233                                 task->tk_client->cl_vers,
1234                                 task->tk_client->cl_server);
1235                 error = -EOPNOTSUPP;
1236                 goto out_err;
1237         case RPC_GARBAGE_ARGS:
1238                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1239                 break;                  /* retry */
1240         default:
1241                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1242                 /* Also retry */
1243         }
1244
1245 out_garbage:
1246         task->tk_client->cl_stats->rpcgarbage++;
1247         if (task->tk_garb_retry) {
1248                 task->tk_garb_retry--;
1249                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1250                 task->tk_action = call_bind;
1251 out_retry:
1252                 return ERR_PTR(-EAGAIN);
1253         }
1254         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1255 out_eio:
1256         error = -EIO;
1257 out_err:
1258         rpc_exit(task, error);
1259         return ERR_PTR(error);
1260 out_overflow:
1261         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1262         goto out_garbage;
1263 }
1264
1265 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1266 {
1267         return 0;
1268 }
1269
1270 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1271 {
1272         return 0;
1273 }
1274
1275 static struct rpc_procinfo rpcproc_null = {
1276         .p_encode = rpcproc_encode_null,
1277         .p_decode = rpcproc_decode_null,
1278 };
1279
1280 int rpc_ping(struct rpc_clnt *clnt, int flags)
1281 {
1282         struct rpc_message msg = {
1283                 .rpc_proc = &rpcproc_null,
1284         };
1285         int err;
1286         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1287         err = rpc_call_sync(clnt, &msg, flags);
1288         put_rpccred(msg.rpc_cred);
1289         return err;
1290 }