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