net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/rpcclnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/in.h>
  31 #include <linux/utsname.h>
  32
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36
  37 #include <linux/nfs.h>
  38
  39
  40 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  41
  42 #ifdef RPC_DEBUG
  43 # define RPCDBG_FACILITY        RPCDBG_CALL
  44 #endif
  45
  46 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  47
  48
  49 static void     call_start(struct rpc_task *task);
  50 static void     call_reserve(struct rpc_task *task);
  51 static void     call_reserveresult(struct rpc_task *task);
  52 static void     call_allocate(struct rpc_task *task);
  53 static void     call_encode(struct rpc_task *task);
  54 static void     call_decode(struct rpc_task *task);
  55 static void     call_bind(struct rpc_task *task);
  56 static void     call_bind_status(struct rpc_task *task);
  57 static void     call_transmit(struct rpc_task *task);
  58 static void     call_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
 522         xprt->sndsize = 0;
 523         if (sndsize)
 524                 xprt->sndsize = sndsize + RPC_SLACK_SPACE;
 525         xprt->rcvsize = 0;
 526         if (rcvsize)
 527                 xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
 528         if (xprt_connected(xprt))
 529                 xprt_sock_setbufsize(xprt);
 530 }
 531
 532 /*
 533  * Return size of largest payload RPC client can support, in bytes
 534  *
 535  * For stream transports, this is one RPC record fragment (see RFC
 536  * 1831), as we don't support multi-record requests yet.  For datagram
 537  * transports, this is the size of an IP packet minus the IP, UDP, and
 538  * RPC header sizes.
 539  */
 540 size_t rpc_max_payload(struct rpc_clnt *clnt)
 541 {
 542         return clnt->cl_xprt->max_payload;
 543 }
 544 EXPORT_SYMBOL(rpc_max_payload);
 545
 546 /*
 547  * Restart an (async) RPC call. Usually called from within the
 548  * exit handler.
 549  */
 550 void
 551 rpc_restart_call(struct rpc_task *task)
 552 {
 553         if (RPC_ASSASSINATED(task))
 554                 return;
 555
 556         task->tk_action = call_start;
 557 }
 558
 559 /*
 560  * 0.  Initial state
 561  *
 562  *     Other FSM states can be visited zero or more times, but
 563  *     this state is visited exactly once for each RPC.
 564  */
 565 static void
 566 call_start(struct rpc_task *task)
 567 {
 568         struct rpc_clnt *clnt = task->tk_client;
 569
 570         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 571                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 572                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 573
 574         /* Increment call count */
 575         task->tk_msg.rpc_proc->p_count++;
 576         clnt->cl_stats->rpccnt++;
 577         task->tk_action = call_reserve;
 578 }
 579
 580 /*
 581  * 1.   Reserve an RPC call slot
 582  */
 583 static void
 584 call_reserve(struct rpc_task *task)
 585 {
 586         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 587
 588         if (!rpcauth_uptodatecred(task)) {
 589                 task->tk_action = call_refresh;
 590                 return;
 591         }
 592
 593         task->tk_status  = 0;
 594         task->tk_action  = call_reserveresult;
 595         xprt_reserve(task);
 596 }
 597
 598 /*
 599  * 1b.  Grok the result of xprt_reserve()
 600  */
 601 static void
 602 call_reserveresult(struct rpc_task *task)
 603 {
 604         int status = task->tk_status;
 605
 606         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 607                                 task->tk_pid, task->tk_status);
 608
 609         /*
 610          * After a call to xprt_reserve(), we must have either
 611          * a request slot or else an error status.
 612          */
 613         task->tk_status = 0;
 614         if (status >= 0) {
 615                 if (task->tk_rqstp) {
 616                         task->tk_action = call_allocate;
 617                         return;
 618                 }
 619
 620                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 621                                 __FUNCTION__, status);
 622                 rpc_exit(task, -EIO);
 623                 return;
 624         }
 625
 626         /*
 627          * Even though there was an error, we may have acquired
 628          * a request slot somehow.  Make sure not to leak it.
 629          */
 630         if (task->tk_rqstp) {
 631                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 632                                 __FUNCTION__, status);
 633                 xprt_release(task);
 634         }
 635
 636         switch (status) {
 637         case -EAGAIN:   /* woken up; retry */
 638                 task->tk_action = call_reserve;
 639                 return;
 640         case -EIO:      /* probably a shutdown */
 641                 break;
 642         default:
 643                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 644                                 __FUNCTION__, status);
 645                 break;
 646         }
 647         rpc_exit(task, status);
 648 }
 649
 650 /*
 651  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 652  *      (Note: buffer memory is freed in rpc_task_release).
 653  */
 654 static void
 655 call_allocate(struct rpc_task *task)
 656 {
 657         unsigned int    bufsiz;
 658
 659         dprintk("RPC: %4d call_allocate (status %d)\n",
 660                                 task->tk_pid, task->tk_status);
 661         task->tk_action = call_bind;
 662         if (task->tk_buffer)
 663                 return;
 664
 665         /* FIXME: compute buffer requirements more exactly using
 666          * auth->au_wslack */
 667         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 668
 669         if (rpc_malloc(task, bufsiz << 1) != NULL)
 670                 return;
 671         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 672
 673         if (RPC_IS_ASYNC(task) || !signalled()) {
 674                 xprt_release(task);
 675                 task->tk_action = call_reserve;
 676                 rpc_delay(task, HZ>>4);
 677                 return;
 678         }
 679
 680         rpc_exit(task, -ERESTARTSYS);
 681 }
 682
 683 /*
 684  * 3.   Encode arguments of an RPC call
 685  */
 686 static void
 687 call_encode(struct rpc_task *task)
 688 {
 689         struct rpc_clnt *clnt = task->tk_client;
 690         struct rpc_rqst *req = task->tk_rqstp;
 691         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 692         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 693         unsigned int    bufsiz;
 694         kxdrproc_t      encode;
 695         int             status;
 696         u32             *p;
 697
 698         dprintk("RPC: %4d call_encode (status %d)\n",
 699                                 task->tk_pid, task->tk_status);
 700
 701         /* Default buffer setup */
 702         bufsiz = task->tk_bufsize >> 1;
 703         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 704         sndbuf->head[0].iov_len  = bufsiz;
 705         sndbuf->tail[0].iov_len  = 0;
 706         sndbuf->page_len         = 0;
 707         sndbuf->len              = 0;
 708         sndbuf->buflen           = bufsiz;
 709         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 710         rcvbuf->head[0].iov_len  = bufsiz;
 711         rcvbuf->tail[0].iov_len  = 0;
 712         rcvbuf->page_len         = 0;
 713         rcvbuf->len              = 0;
 714         rcvbuf->buflen           = bufsiz;
 715
 716         /* Encode header and provided arguments */
 717         encode = task->tk_msg.rpc_proc->p_encode;
 718         if (!(p = call_header(task))) {
 719                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 720                 rpc_exit(task, -EIO);
 721                 return;
 722         }
 723         if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
 724                                                  task->tk_msg.rpc_argp)) < 0) {
 725                 printk(KERN_WARNING "%s: can't encode arguments: %d\n",
 726                                 clnt->cl_protname, -status);
 727                 rpc_exit(task, status);
 728         }
 729 }
 730
 731 /*
 732  * 4.   Get the server port number if not yet set
 733  */
 734 static void
 735 call_bind(struct rpc_task *task)
 736 {
 737         struct rpc_clnt *clnt = task->tk_client;
 738
 739         dprintk("RPC: %4d call_bind (status %d)\n",
 740                                 task->tk_pid, task->tk_status);
 741
 742         task->tk_action = call_connect;
 743         if (!clnt->cl_port) {
 744                 task->tk_action = call_bind_status;
 745                 task->tk_timeout = RPC_CONNECT_TIMEOUT;
 746                 rpc_getport(task, clnt);
 747         }
 748 }
 749
 750 /*
 751  * 4a.  Sort out bind result
 752  */
 753 static void
 754 call_bind_status(struct rpc_task *task)
 755 {
 756         int status = -EACCES;
 757
 758         if (task->tk_status >= 0) {
 759                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 760                                         task->tk_pid, task->tk_status);
 761                 task->tk_status = 0;
 762                 task->tk_action = call_connect;
 763                 return;
 764         }
 765
 766         switch (task->tk_status) {
 767         case -EACCES:
 768                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 769                                 task->tk_pid);
 770                 break;
 771         case -ETIMEDOUT:
 772                 dprintk("RPC: %4d rpcbind request timed out\n",
 773                                 task->tk_pid);
 774                 if (RPC_IS_SOFT(task)) {
 775                         status = -EIO;
 776                         break;
 777                 }
 778                 goto retry_bind;
 779         case -EPFNOSUPPORT:
 780                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 781                                 task->tk_pid);
 782                 break;
 783         case -EPROTONOSUPPORT:
 784                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 785                                 task->tk_pid);
 786                 break;
 787         default:
 788                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 789                                 task->tk_pid, -task->tk_status);
 790                 status = -EIO;
 791                 break;
 792         }
 793
 794         rpc_exit(task, status);
 795         return;
 796
 797 retry_bind:
 798         task->tk_status = 0;
 799         task->tk_action = call_bind;
 800         return;
 801 }
 802
 803 /*
 804  * 4b.  Connect to the RPC server
 805  */
 806 static void
 807 call_connect(struct rpc_task *task)
 808 {
 809         struct rpc_xprt *xprt = task->tk_xprt;
 810
 811         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 812                         task->tk_pid, xprt,
 813                         (xprt_connected(xprt) ? "is" : "is not"));
 814
 815         task->tk_action = call_transmit;
 816         if (!xprt_connected(xprt)) {
 817                 task->tk_action = call_connect_status;
 818                 if (task->tk_status < 0)
 819                         return;
 820                 xprt_connect(task);
 821         }
 822 }
 823
 824 /*
 825  * 4c.  Sort out connect result
 826  */
 827 static void
 828 call_connect_status(struct rpc_task *task)
 829 {
 830         struct rpc_clnt *clnt = task->tk_client;
 831         int status = task->tk_status;
 832
 833         dprintk("RPC: %5u call_connect_status (status %d)\n",
 834                                 task->tk_pid, task->tk_status);
 835
 836         task->tk_status = 0;
 837         if (status >= 0) {
 838                 clnt->cl_stats->netreconn++;
 839                 task->tk_action = call_transmit;
 840                 return;
 841         }
 842
 843         /* Something failed: remote service port may have changed */
 844         if (clnt->cl_autobind)
 845                 clnt->cl_port = 0;
 846
 847         switch (status) {
 848         case -ENOTCONN:
 849         case -ETIMEDOUT:
 850         case -EAGAIN:
 851                 task->tk_action = call_bind;
 852                 break;
 853         default:
 854                 rpc_exit(task, -EIO);
 855                 break;
 856         }
 857 }
 858
 859 /*
 860  * 5.   Transmit the RPC request, and wait for reply
 861  */
 862 static void
 863 call_transmit(struct rpc_task *task)
 864 {
 865         dprintk("RPC: %4d call_transmit (status %d)\n",
 866                                 task->tk_pid, task->tk_status);
 867
 868         task->tk_action = call_status;
 869         if (task->tk_status < 0)
 870                 return;
 871         task->tk_status = xprt_prepare_transmit(task);
 872         if (task->tk_status != 0)
 873                 return;
 874         /* Encode here so that rpcsec_gss can use correct sequence number. */
 875         if (!task->tk_rqstp->rq_bytes_sent)
 876                 call_encode(task);
 877         if (task->tk_status < 0)
 878                 return;
 879         xprt_transmit(task);
 880         if (task->tk_status < 0)
 881                 return;
 882         if (!task->tk_msg.rpc_proc->p_decode) {
 883                 task->tk_action = NULL;
 884                 rpc_wake_up_task(task);
 885         }
 886 }
 887
 888 /*
 889  * 6.   Sort out the RPC call status
 890  */
 891 static void
 892 call_status(struct rpc_task *task)
 893 {
 894         struct rpc_clnt *clnt = task->tk_client;
 895         struct rpc_rqst *req = task->tk_rqstp;
 896         int             status;
 897
 898         if (req->rq_received > 0 && !req->rq_bytes_sent)
 899                 task->tk_status = req->rq_received;
 900
 901         dprintk("RPC: %4d call_status (status %d)\n",
 902                                 task->tk_pid, task->tk_status);
 903
 904         status = task->tk_status;
 905         if (status >= 0) {
 906                 task->tk_action = call_decode;
 907                 return;
 908         }
 909
 910         task->tk_status = 0;
 911         switch(status) {
 912         case -ETIMEDOUT:
 913                 task->tk_action = call_timeout;
 914                 break;
 915         case -ECONNREFUSED:
 916         case -ENOTCONN:
 917                 req->rq_bytes_sent = 0;
 918                 if (clnt->cl_autobind)
 919                         clnt->cl_port = 0;
 920                 task->tk_action = call_bind;
 921                 break;
 922         case -EAGAIN:
 923                 task->tk_action = call_transmit;
 924                 break;
 925         case -EIO:
 926                 /* shutdown or soft timeout */
 927                 rpc_exit(task, status);
 928                 break;
 929         default:
 930                 if (clnt->cl_chatty)
 931                         printk("%s: RPC call returned error %d\n",
 932                                clnt->cl_protname, -status);
 933                 rpc_exit(task, status);
 934                 break;
 935         }
 936 }
 937
 938 /*
 939  * 6a.  Handle RPC timeout
 940  *      We do not release the request slot, so we keep using the
 941  *      same XID for all retransmits.
 942  */
 943 static void
 944 call_timeout(struct rpc_task *task)
 945 {
 946         struct rpc_clnt *clnt = task->tk_client;
 947
 948         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 949                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 950                 goto retry;
 951         }
 952
 953         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 954         if (RPC_IS_SOFT(task)) {
 955                 if (clnt->cl_chatty)
 956                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 957                                 clnt->cl_protname, clnt->cl_server);
 958                 rpc_exit(task, -EIO);
 959                 return;
 960         }
 961
 962         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 963                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 964                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 965                         clnt->cl_protname, clnt->cl_server);
 966         }
 967         if (clnt->cl_autobind)
 968                 clnt->cl_port = 0;
 969
 970 retry:
 971         clnt->cl_stats->rpcretrans++;
 972         task->tk_action = call_bind;
 973         task->tk_status = 0;
 974 }
 975
 976 /*
 977  * 7.   Decode the RPC reply
 978  */
 979 static void
 980 call_decode(struct rpc_task *task)
 981 {
 982         struct rpc_clnt *clnt = task->tk_client;
 983         struct rpc_rqst *req = task->tk_rqstp;
 984         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
 985         u32             *p;
 986
 987         dprintk("RPC: %4d call_decode (status %d)\n",
 988                                 task->tk_pid, task->tk_status);
 989
 990         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
 991                 printk(KERN_NOTICE "%s: server %s OK\n",
 992                         clnt->cl_protname, clnt->cl_server);
 993                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
 994         }
 995
 996         if (task->tk_status < 12) {
 997                 if (!RPC_IS_SOFT(task)) {
 998                         task->tk_action = call_bind;
 999                         clnt->cl_stats->rpcretrans++;
1000                         goto out_retry;
1001                 }
1002                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1003                         clnt->cl_protname, task->tk_status);
1004                 rpc_exit(task, -EIO);
1005                 return;
1006         }
1007
1008         req->rq_rcv_buf.len = req->rq_private_buf.len;
1009
1010         /* Check that the softirq receive buffer is valid */
1011         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1012                                 sizeof(req->rq_rcv_buf)) != 0);
1013
1014         /* Verify the RPC header */
1015         if (!(p = call_verify(task))) {
1016                 if (task->tk_action == NULL)
1017                         return;
1018                 goto out_retry;
1019         }
1020
1021         task->tk_action = NULL;
1022
1023         if (decode)
1024                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1025                                                       task->tk_msg.rpc_resp);
1026         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1027                                         task->tk_status);
1028         return;
1029 out_retry:
1030         req->rq_received = req->rq_private_buf.len = 0;
1031         task->tk_status = 0;
1032 }
1033
1034 /*
1035  * 8.   Refresh the credentials if rejected by the server
1036  */
1037 static void
1038 call_refresh(struct rpc_task *task)
1039 {
1040         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1041
1042         xprt_release(task);     /* Must do to obtain new XID */
1043         task->tk_action = call_refreshresult;
1044         task->tk_status = 0;
1045         task->tk_client->cl_stats->rpcauthrefresh++;
1046         rpcauth_refreshcred(task);
1047 }
1048
1049 /*
1050  * 8a.  Process the results of a credential refresh
1051  */
1052 static void
1053 call_refreshresult(struct rpc_task *task)
1054 {
1055         int status = task->tk_status;
1056         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1057                                 task->tk_pid, task->tk_status);
1058
1059         task->tk_status = 0;
1060         task->tk_action = call_reserve;
1061         if (status >= 0 && rpcauth_uptodatecred(task))
1062                 return;
1063         if (status == -EACCES) {
1064                 rpc_exit(task, -EACCES);
1065                 return;
1066         }
1067         task->tk_action = call_refresh;
1068         if (status != -ETIMEDOUT)
1069                 rpc_delay(task, 3*HZ);
1070         return;
1071 }
1072
1073 /*
1074  * Call header serialization
1075  */
1076 static u32 *
1077 call_header(struct rpc_task *task)
1078 {
1079         struct rpc_clnt *clnt = task->tk_client;
1080         struct rpc_xprt *xprt = clnt->cl_xprt;
1081         struct rpc_rqst *req = task->tk_rqstp;
1082         u32             *p = req->rq_svec[0].iov_base;
1083
1084         /* FIXME: check buffer size? */
1085         if (xprt->stream)
1086                 *p++ = 0;               /* fill in later */
1087         *p++ = req->rq_xid;             /* XID */
1088         *p++ = htonl(RPC_CALL);         /* CALL */
1089         *p++ = htonl(RPC_VERSION);      /* RPC version */
1090         *p++ = htonl(clnt->cl_prog);    /* program number */
1091         *p++ = htonl(clnt->cl_vers);    /* program version */
1092         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1093         p = rpcauth_marshcred(task, p);
1094         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1095         return p;
1096 }
1097
1098 /*
1099  * Reply header verification
1100  */
1101 static u32 *
1102 call_verify(struct rpc_task *task)
1103 {
1104         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1105         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1106         u32     *p = iov->iov_base, n;
1107         int error = -EACCES;
1108
1109         if ((len -= 3) < 0)
1110                 goto out_overflow;
1111         p += 1; /* skip XID */
1112
1113         if ((n = ntohl(*p++)) != RPC_REPLY) {
1114                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1115                 goto out_retry;
1116         }
1117         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1118                 if (--len < 0)
1119                         goto out_overflow;
1120                 switch ((n = ntohl(*p++))) {
1121                         case RPC_AUTH_ERROR:
1122                                 break;
1123                         case RPC_MISMATCH:
1124                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1125                                 error = -EPROTONOSUPPORT;
1126                                 goto out_err;
1127                         default:
1128                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1129                                 goto out_eio;
1130                 }
1131                 if (--len < 0)
1132                         goto out_overflow;
1133                 switch ((n = ntohl(*p++))) {
1134                 case RPC_AUTH_REJECTEDCRED:
1135                 case RPC_AUTH_REJECTEDVERF:
1136                 case RPCSEC_GSS_CREDPROBLEM:
1137                 case RPCSEC_GSS_CTXPROBLEM:
1138                         if (!task->tk_cred_retry)
1139                                 break;
1140                         task->tk_cred_retry--;
1141                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1142                                                         task->tk_pid);
1143                         rpcauth_invalcred(task);
1144                         task->tk_action = call_refresh;
1145                         return NULL;
1146                 case RPC_AUTH_BADCRED:
1147                 case RPC_AUTH_BADVERF:
1148                         /* possibly garbled cred/verf? */
1149                         if (!task->tk_garb_retry)
1150                                 break;
1151                         task->tk_garb_retry--;
1152                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1153                                                         task->tk_pid);
1154                         task->tk_action = call_bind;
1155                         return NULL;
1156                 case RPC_AUTH_TOOWEAK:
1157                         printk(KERN_NOTICE "call_verify: server requires stronger "
1158                                "authentication.\n");
1159                         break;
1160                 default:
1161                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1162                         error = -EIO;
1163                 }
1164                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1165                                                 task->tk_pid, n);
1166                 goto out_err;
1167         }
1168         if (!(p = rpcauth_checkverf(task, p))) {
1169                 printk(KERN_WARNING "call_verify: auth check failed\n");
1170                 goto out_retry;         /* bad verifier, retry */
1171         }
1172         len = p - (u32 *)iov->iov_base - 1;
1173         if (len < 0)
1174                 goto out_overflow;
1175         switch ((n = ntohl(*p++))) {
1176         case RPC_SUCCESS:
1177                 return p;
1178         case RPC_PROG_UNAVAIL:
1179                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1180                                 (unsigned int)task->tk_client->cl_prog,
1181                                 task->tk_client->cl_server);
1182                 error = -EPFNOSUPPORT;
1183                 goto out_err;
1184         case RPC_PROG_MISMATCH:
1185                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1186                                 (unsigned int)task->tk_client->cl_prog,
1187                                 (unsigned int)task->tk_client->cl_vers,
1188                                 task->tk_client->cl_server);
1189                 error = -EPROTONOSUPPORT;
1190                 goto out_err;
1191         case RPC_PROC_UNAVAIL:
1192                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1193                                 task->tk_msg.rpc_proc,
1194                                 task->tk_client->cl_prog,
1195                                 task->tk_client->cl_vers,
1196                                 task->tk_client->cl_server);
1197                 error = -EOPNOTSUPP;
1198                 goto out_err;
1199         case RPC_GARBAGE_ARGS:
1200                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1201                 break;                  /* retry */
1202         default:
1203                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1204                 /* Also retry */
1205         }
1206
1207 out_retry:
1208         task->tk_client->cl_stats->rpcgarbage++;
1209         if (task->tk_garb_retry) {
1210                 task->tk_garb_retry--;
1211                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1212                 task->tk_action = call_bind;
1213                 return NULL;
1214         }
1215         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1216 out_eio:
1217         error = -EIO;
1218 out_err:
1219         rpc_exit(task, error);
1220         return NULL;
1221 out_overflow:
1222         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1223         goto out_retry;
1224 }
1225
1226 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1227 {
1228         return 0;
1229 }
1230
1231 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1232 {
1233         return 0;
1234 }
1235
1236 static struct rpc_procinfo rpcproc_null = {
1237         .p_encode = rpcproc_encode_null,
1238         .p_decode = rpcproc_decode_null,
1239 };
1240
1241 int rpc_ping(struct rpc_clnt *clnt, int flags)
1242 {
1243         struct rpc_message msg = {
1244                 .rpc_proc = &rpcproc_null,
1245         };
1246         int err;
1247         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1248         err = rpc_call_sync(clnt, &msg, flags);
1249         put_rpccred(msg.rpc_cred);
1250         return err;
1251 }