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