net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/utsname.h>
  31
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35
  36 #include <linux/nfs.h>
  37
  38
  39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  40
  41 #ifdef RPC_DEBUG
  42 # define RPCDBG_FACILITY        RPCDBG_CALL
  43 #endif
  44
  45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  46
  47
  48 static void     call_start(struct rpc_task *task);
  49 static void     call_reserve(struct rpc_task *task);
  50 static void     call_reserveresult(struct rpc_task *task);
  51 static void     call_allocate(struct rpc_task *task);
  52 static void     call_encode(struct rpc_task *task);
  53 static void     call_decode(struct rpc_task *task);
  54 static void     call_bind(struct rpc_task *task);
  55 static void     call_bind_status(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_transmit_status(struct rpc_task *task);
  59 static void     call_refresh(struct rpc_task *task);
  60 static void     call_refreshresult(struct rpc_task *task);
  61 static void     call_timeout(struct rpc_task *task);
  62 static void     call_connect(struct rpc_task *task);
  63 static void     call_connect_status(struct rpc_task *task);
  64 static u32 *    call_header(struct rpc_task *task);
  65 static u32 *    call_verify(struct rpc_task *task);
  66
  67
  68 static int
  69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  70 {
  71         static uint32_t clntid;
  72         int error;
  73
  74         if (dir_name == NULL)
  75                 return 0;
  76         for (;;) {
  77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  78                                 "%s/clnt%x", dir_name,
  79                                 (unsigned int)clntid++);
  80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  82                 if (!IS_ERR(clnt->cl_dentry))
  83                         return 0;
  84                 error = PTR_ERR(clnt->cl_dentry);
  85                 if (error != -EEXIST) {
  86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  87                                         clnt->cl_pathname, error);
  88                         return error;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Create an RPC client
  95  * FIXME: This should also take a flags argument (as in task->tk_flags).
  96  * It's called (among others) from pmap_create_client, which may in
  97  * turn be called by an async task. In this case, rpciod should not be
  98  * made to sleep too long.
  99  */
 100 struct rpc_clnt *
 101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 102                   struct rpc_program *program, u32 vers,
 103                   rpc_authflavor_t flavor)
 104 {
 105         struct rpc_version      *version;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct rpc_auth         *auth;
 108         int err;
 109         int len;
 110
 111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 112                 program->name, servname, xprt);
 113
 114         err = -EINVAL;
 115         if (!xprt)
 116                 goto out_err;
 117         if (vers >= program->nrvers || !(version = program->version[vers]))
 118                 goto out_err;
 119
 120         err = -ENOMEM;
 121         clnt = 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 = 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                 wait_event_timeout(destroy_wait,
 272                         !atomic_read(&clnt->cl_users), 1*HZ);
 273         }
 274
 275         if (atomic_read(&clnt->cl_users) < 0) {
 276                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 277                                 clnt, atomic_read(&clnt->cl_users));
 278 #ifdef RPC_DEBUG
 279                 rpc_show_tasks();
 280 #endif
 281                 BUG();
 282         }
 283
 284         return rpc_destroy_client(clnt);
 285 }
 286
 287 /*
 288  * Delete an RPC client
 289  */
 290 int
 291 rpc_destroy_client(struct rpc_clnt *clnt)
 292 {
 293         if (!atomic_dec_and_test(&clnt->cl_count))
 294                 return 1;
 295         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 296
 297         dprintk("RPC: destroying %s client for %s\n",
 298                         clnt->cl_protname, clnt->cl_server);
 299         if (clnt->cl_auth) {
 300                 rpcauth_destroy(clnt->cl_auth);
 301                 clnt->cl_auth = NULL;
 302         }
 303         if (clnt->cl_parent != clnt) {
 304                 rpc_destroy_client(clnt->cl_parent);
 305                 goto out_free;
 306         }
 307         if (clnt->cl_pathname[0])
 308                 rpc_rmdir(clnt->cl_pathname);
 309         if (clnt->cl_xprt) {
 310                 xprt_destroy(clnt->cl_xprt);
 311                 clnt->cl_xprt = NULL;
 312         }
 313         if (clnt->cl_server != clnt->cl_inline_name)
 314                 kfree(clnt->cl_server);
 315 out_free:
 316         kfree(clnt);
 317         return 0;
 318 }
 319
 320 /*
 321  * Release an RPC client
 322  */
 323 void
 324 rpc_release_client(struct rpc_clnt *clnt)
 325 {
 326         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 327                                 clnt, atomic_read(&clnt->cl_users));
 328
 329         if (!atomic_dec_and_test(&clnt->cl_users))
 330                 return;
 331         wake_up(&destroy_wait);
 332         if (clnt->cl_oneshot || clnt->cl_dead)
 333                 rpc_destroy_client(clnt);
 334 }
 335
 336 /**
 337  * rpc_bind_new_program - bind a new RPC program to an existing client
 338  * @old - old rpc_client
 339  * @program - rpc program to set
 340  * @vers - rpc program version
 341  *
 342  * Clones the rpc client and sets up a new RPC program. This is mainly
 343  * of use for enabling different RPC programs to share the same transport.
 344  * The Sun NFSv2/v3 ACL protocol can do this.
 345  */
 346 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 347                                       struct rpc_program *program,
 348                                       int vers)
 349 {
 350         struct rpc_clnt *clnt;
 351         struct rpc_version *version;
 352         int err;
 353
 354         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 355         version = program->version[vers];
 356         clnt = rpc_clone_client(old);
 357         if (IS_ERR(clnt))
 358                 goto out;
 359         clnt->cl_procinfo = version->procs;
 360         clnt->cl_maxproc  = version->nrprocs;
 361         clnt->cl_protname = program->name;
 362         clnt->cl_prog     = program->number;
 363         clnt->cl_vers     = version->number;
 364         clnt->cl_stats    = program->stats;
 365         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 366         if (err != 0) {
 367                 rpc_shutdown_client(clnt);
 368                 clnt = ERR_PTR(err);
 369         }
 370 out:
 371         return clnt;
 372 }
 373
 374 /*
 375  * Default callback for async RPC calls
 376  */
 377 static void
 378 rpc_default_callback(struct rpc_task *task, void *data)
 379 {
 380 }
 381
 382 static const struct rpc_call_ops rpc_default_ops = {
 383         .rpc_call_done = rpc_default_callback,
 384 };
 385
 386 /*
 387  *      Export the signal mask handling for synchronous code that
 388  *      sleeps on RPC calls
 389  */
 390 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 391
 392 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 393 {
 394         unsigned long   sigallow = sigmask(SIGKILL);
 395         sigset_t sigmask;
 396
 397         /* Block all signals except those listed in sigallow */
 398         if (intr)
 399                 sigallow |= RPC_INTR_SIGNALS;
 400         siginitsetinv(&sigmask, sigallow);
 401         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 402 }
 403
 404 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 405 {
 406         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 407 }
 408
 409 static inline void rpc_restore_sigmask(sigset_t *oldset)
 410 {
 411         sigprocmask(SIG_SETMASK, oldset, NULL);
 412 }
 413
 414 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 415 {
 416         rpc_save_sigmask(oldset, clnt->cl_intr);
 417 }
 418
 419 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 420 {
 421         rpc_restore_sigmask(oldset);
 422 }
 423
 424 /*
 425  * New rpc_call implementation
 426  */
 427 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 428 {
 429         struct rpc_task *task;
 430         sigset_t        oldset;
 431         int             status;
 432
 433         /* If this client is slain all further I/O fails */
 434         if (clnt->cl_dead)
 435                 return -EIO;
 436
 437         BUG_ON(flags & RPC_TASK_ASYNC);
 438
 439         status = -ENOMEM;
 440         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 441         if (task == NULL)
 442                 goto out;
 443
 444         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 445         rpc_task_sigmask(task, &oldset);
 446
 447         rpc_call_setup(task, msg, 0);
 448
 449         /* Set up the call info struct and execute the task */
 450         status = task->tk_status;
 451         if (status == 0) {
 452                 atomic_inc(&task->tk_count);
 453                 status = rpc_execute(task);
 454                 if (status == 0)
 455                         status = task->tk_status;
 456         }
 457         rpc_restore_sigmask(&oldset);
 458         rpc_release_task(task);
 459 out:
 460         return status;
 461 }
 462
 463 /*
 464  * New rpc_call implementation
 465  */
 466 int
 467 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 468                const struct rpc_call_ops *tk_ops, void *data)
 469 {
 470         struct rpc_task *task;
 471         sigset_t        oldset;
 472         int             status;
 473
 474         /* If this client is slain all further I/O fails */
 475         if (clnt->cl_dead)
 476                 return -EIO;
 477
 478         flags |= RPC_TASK_ASYNC;
 479
 480         /* Create/initialize a new RPC task */
 481         status = -ENOMEM;
 482         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 483                 goto out;
 484
 485         /* Mask signals on GSS_AUTH upcalls */
 486         rpc_task_sigmask(task, &oldset);
 487
 488         rpc_call_setup(task, msg, 0);
 489
 490         /* Set up the call info struct and execute the task */
 491         status = task->tk_status;
 492         if (status == 0)
 493                 rpc_execute(task);
 494         else
 495                 rpc_release_task(task);
 496
 497         rpc_restore_sigmask(&oldset);
 498 out:
 499         return status;
 500 }
 501
 502
 503 void
 504 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 505 {
 506         task->tk_msg   = *msg;
 507         task->tk_flags |= flags;
 508         /* Bind the user cred */
 509         if (task->tk_msg.rpc_cred != NULL)
 510                 rpcauth_holdcred(task);
 511         else
 512                 rpcauth_bindcred(task);
 513
 514         if (task->tk_status == 0)
 515                 task->tk_action = call_start;
 516         else
 517                 task->tk_action = rpc_exit_task;
 518 }
 519
 520 void
 521 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 522 {
 523         struct rpc_xprt *xprt = clnt->cl_xprt;
 524         if (xprt->ops->set_buffer_size)
 525                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 526 }
 527
 528 /*
 529  * Return size of largest payload RPC client can support, in bytes
 530  *
 531  * For stream transports, this is one RPC record fragment (see RFC
 532  * 1831), as we don't support multi-record requests yet.  For datagram
 533  * transports, this is the size of an IP packet minus the IP, UDP, and
 534  * RPC header sizes.
 535  */
 536 size_t rpc_max_payload(struct rpc_clnt *clnt)
 537 {
 538         return clnt->cl_xprt->max_payload;
 539 }
 540 EXPORT_SYMBOL(rpc_max_payload);
 541
 542 /**
 543  * rpc_force_rebind - force transport to check that remote port is unchanged
 544  * @clnt: client to rebind
 545  *
 546  */
 547 void rpc_force_rebind(struct rpc_clnt *clnt)
 548 {
 549         if (clnt->cl_autobind)
 550                 clnt->cl_port = 0;
 551 }
 552 EXPORT_SYMBOL(rpc_force_rebind);
 553
 554 /*
 555  * Restart an (async) RPC call. Usually called from within the
 556  * exit handler.
 557  */
 558 void
 559 rpc_restart_call(struct rpc_task *task)
 560 {
 561         if (RPC_ASSASSINATED(task))
 562                 return;
 563
 564         task->tk_action = call_start;
 565 }
 566
 567 /*
 568  * 0.  Initial state
 569  *
 570  *     Other FSM states can be visited zero or more times, but
 571  *     this state is visited exactly once for each RPC.
 572  */
 573 static void
 574 call_start(struct rpc_task *task)
 575 {
 576         struct rpc_clnt *clnt = task->tk_client;
 577
 578         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 579                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 580                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 581
 582         /* Increment call count */
 583         task->tk_msg.rpc_proc->p_count++;
 584         clnt->cl_stats->rpccnt++;
 585         task->tk_action = call_reserve;
 586 }
 587
 588 /*
 589  * 1.   Reserve an RPC call slot
 590  */
 591 static void
 592 call_reserve(struct rpc_task *task)
 593 {
 594         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 595
 596         if (!rpcauth_uptodatecred(task)) {
 597                 task->tk_action = call_refresh;
 598                 return;
 599         }
 600
 601         task->tk_status  = 0;
 602         task->tk_action  = call_reserveresult;
 603         xprt_reserve(task);
 604 }
 605
 606 /*
 607  * 1b.  Grok the result of xprt_reserve()
 608  */
 609 static void
 610 call_reserveresult(struct rpc_task *task)
 611 {
 612         int status = task->tk_status;
 613
 614         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 615                                 task->tk_pid, task->tk_status);
 616
 617         /*
 618          * After a call to xprt_reserve(), we must have either
 619          * a request slot or else an error status.
 620          */
 621         task->tk_status = 0;
 622         if (status >= 0) {
 623                 if (task->tk_rqstp) {
 624                         task->tk_action = call_allocate;
 625                         return;
 626                 }
 627
 628                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 629                                 __FUNCTION__, status);
 630                 rpc_exit(task, -EIO);
 631                 return;
 632         }
 633
 634         /*
 635          * Even though there was an error, we may have acquired
 636          * a request slot somehow.  Make sure not to leak it.
 637          */
 638         if (task->tk_rqstp) {
 639                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 640                                 __FUNCTION__, status);
 641                 xprt_release(task);
 642         }
 643
 644         switch (status) {
 645         case -EAGAIN:   /* woken up; retry */
 646                 task->tk_action = call_reserve;
 647                 return;
 648         case -EIO:      /* probably a shutdown */
 649                 break;
 650         default:
 651                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 652                                 __FUNCTION__, status);
 653                 break;
 654         }
 655         rpc_exit(task, status);
 656 }
 657
 658 /*
 659  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 660  *      (Note: buffer memory is freed in xprt_release).
 661  */
 662 static void
 663 call_allocate(struct rpc_task *task)
 664 {
 665         struct rpc_rqst *req = task->tk_rqstp;
 666         struct rpc_xprt *xprt = task->tk_xprt;
 667         unsigned int    bufsiz;
 668
 669         dprintk("RPC: %4d call_allocate (status %d)\n",
 670                                 task->tk_pid, task->tk_status);
 671         task->tk_action = call_bind;
 672         if (req->rq_buffer)
 673                 return;
 674
 675         /* FIXME: compute buffer requirements more exactly using
 676          * auth->au_wslack */
 677         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 678
 679         if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
 680                 return;
 681         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 682
 683         if (RPC_IS_ASYNC(task) || !signalled()) {
 684                 xprt_release(task);
 685                 task->tk_action = call_reserve;
 686                 rpc_delay(task, HZ>>4);
 687                 return;
 688         }
 689
 690         rpc_exit(task, -ERESTARTSYS);
 691 }
 692
 693 static inline int
 694 rpc_task_need_encode(struct rpc_task *task)
 695 {
 696         return task->tk_rqstp->rq_snd_buf.len == 0;
 697 }
 698
 699 static inline void
 700 rpc_task_force_reencode(struct rpc_task *task)
 701 {
 702         task->tk_rqstp->rq_snd_buf.len = 0;
 703 }
 704
 705 /*
 706  * 3.   Encode arguments of an RPC call
 707  */
 708 static void
 709 call_encode(struct rpc_task *task)
 710 {
 711         struct rpc_rqst *req = task->tk_rqstp;
 712         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 713         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 714         unsigned int    bufsiz;
 715         kxdrproc_t      encode;
 716         u32             *p;
 717
 718         dprintk("RPC: %4d call_encode (status %d)\n",
 719                                 task->tk_pid, task->tk_status);
 720
 721         /* Default buffer setup */
 722         bufsiz = req->rq_bufsize >> 1;
 723         sndbuf->head[0].iov_base = (void *)req->rq_buffer;
 724         sndbuf->head[0].iov_len  = bufsiz;
 725         sndbuf->tail[0].iov_len  = 0;
 726         sndbuf->page_len         = 0;
 727         sndbuf->len              = 0;
 728         sndbuf->buflen           = bufsiz;
 729         rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
 730         rcvbuf->head[0].iov_len  = bufsiz;
 731         rcvbuf->tail[0].iov_len  = 0;
 732         rcvbuf->page_len         = 0;
 733         rcvbuf->len              = 0;
 734         rcvbuf->buflen           = bufsiz;
 735
 736         /* Encode header and provided arguments */
 737         encode = task->tk_msg.rpc_proc->p_encode;
 738         if (!(p = call_header(task))) {
 739                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 740                 rpc_exit(task, -EIO);
 741                 return;
 742         }
 743         if (encode == NULL)
 744                 return;
 745
 746         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 747                         task->tk_msg.rpc_argp);
 748         if (task->tk_status == -ENOMEM) {
 749                 /* XXX: Is this sane? */
 750                 rpc_delay(task, 3*HZ);
 751                 task->tk_status = -EAGAIN;
 752         }
 753 }
 754
 755 /*
 756  * 4.   Get the server port number if not yet set
 757  */
 758 static void
 759 call_bind(struct rpc_task *task)
 760 {
 761         struct rpc_clnt *clnt = task->tk_client;
 762
 763         dprintk("RPC: %4d call_bind (status %d)\n",
 764                                 task->tk_pid, task->tk_status);
 765
 766         task->tk_action = call_connect;
 767         if (!clnt->cl_port) {
 768                 task->tk_action = call_bind_status;
 769                 task->tk_timeout = task->tk_xprt->bind_timeout;
 770                 rpc_getport(task, clnt);
 771         }
 772 }
 773
 774 /*
 775  * 4a.  Sort out bind result
 776  */
 777 static void
 778 call_bind_status(struct rpc_task *task)
 779 {
 780         int status = -EACCES;
 781
 782         if (task->tk_status >= 0) {
 783                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 784                                         task->tk_pid, task->tk_status);
 785                 task->tk_status = 0;
 786                 task->tk_action = call_connect;
 787                 return;
 788         }
 789
 790         switch (task->tk_status) {
 791         case -EACCES:
 792                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 793                                 task->tk_pid);
 794                 rpc_delay(task, 3*HZ);
 795                 goto retry_bind;
 796         case -ETIMEDOUT:
 797                 dprintk("RPC: %4d rpcbind request timed out\n",
 798                                 task->tk_pid);
 799                 if (RPC_IS_SOFT(task)) {
 800                         status = -EIO;
 801                         break;
 802                 }
 803                 goto retry_bind;
 804         case -EPFNOSUPPORT:
 805                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 806                                 task->tk_pid);
 807                 break;
 808         case -EPROTONOSUPPORT:
 809                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 810                                 task->tk_pid);
 811                 break;
 812         default:
 813                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 814                                 task->tk_pid, -task->tk_status);
 815                 status = -EIO;
 816                 break;
 817         }
 818
 819         rpc_exit(task, status);
 820         return;
 821
 822 retry_bind:
 823         task->tk_status = 0;
 824         task->tk_action = call_bind;
 825         return;
 826 }
 827
 828 /*
 829  * 4b.  Connect to the RPC server
 830  */
 831 static void
 832 call_connect(struct rpc_task *task)
 833 {
 834         struct rpc_xprt *xprt = task->tk_xprt;
 835
 836         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 837                         task->tk_pid, xprt,
 838                         (xprt_connected(xprt) ? "is" : "is not"));
 839
 840         task->tk_action = call_transmit;
 841         if (!xprt_connected(xprt)) {
 842                 task->tk_action = call_connect_status;
 843                 if (task->tk_status < 0)
 844                         return;
 845                 xprt_connect(task);
 846         }
 847 }
 848
 849 /*
 850  * 4c.  Sort out connect result
 851  */
 852 static void
 853 call_connect_status(struct rpc_task *task)
 854 {
 855         struct rpc_clnt *clnt = task->tk_client;
 856         int status = task->tk_status;
 857
 858         dprintk("RPC: %5u call_connect_status (status %d)\n",
 859                                 task->tk_pid, task->tk_status);
 860
 861         task->tk_status = 0;
 862         if (status >= 0) {
 863                 clnt->cl_stats->netreconn++;
 864                 task->tk_action = call_transmit;
 865                 return;
 866         }
 867
 868         /* Something failed: remote service port may have changed */
 869         rpc_force_rebind(clnt);
 870
 871         switch (status) {
 872         case -ENOTCONN:
 873         case -ETIMEDOUT:
 874         case -EAGAIN:
 875                 task->tk_action = call_bind;
 876                 break;
 877         default:
 878                 rpc_exit(task, -EIO);
 879                 break;
 880         }
 881 }
 882
 883 /*
 884  * 5.   Transmit the RPC request, and wait for reply
 885  */
 886 static void
 887 call_transmit(struct rpc_task *task)
 888 {
 889         dprintk("RPC: %4d call_transmit (status %d)\n",
 890                                 task->tk_pid, task->tk_status);
 891
 892         task->tk_action = call_status;
 893         if (task->tk_status < 0)
 894                 return;
 895         task->tk_status = xprt_prepare_transmit(task);
 896         if (task->tk_status != 0)
 897                 return;
 898         /* Encode here so that rpcsec_gss can use correct sequence number. */
 899         if (rpc_task_need_encode(task)) {
 900                 task->tk_rqstp->rq_bytes_sent = 0;
 901                 call_encode(task);
 902                 /* Did the encode result in an error condition? */
 903                 if (task->tk_status != 0)
 904                         goto out_nosend;
 905         }
 906         task->tk_action = call_transmit_status;
 907         xprt_transmit(task);
 908         if (task->tk_status < 0)
 909                 return;
 910         if (!task->tk_msg.rpc_proc->p_decode) {
 911                 task->tk_action = rpc_exit_task;
 912                 rpc_wake_up_task(task);
 913         }
 914         return;
 915 out_nosend:
 916         /* release socket write lock before attempting to handle error */
 917         xprt_abort_transmit(task);
 918         rpc_task_force_reencode(task);
 919 }
 920
 921 /*
 922  * 6.   Sort out the RPC call status
 923  */
 924 static void
 925 call_status(struct rpc_task *task)
 926 {
 927         struct rpc_clnt *clnt = task->tk_client;
 928         struct rpc_rqst *req = task->tk_rqstp;
 929         int             status;
 930
 931         if (req->rq_received > 0 && !req->rq_bytes_sent)
 932                 task->tk_status = req->rq_received;
 933
 934         dprintk("RPC: %4d call_status (status %d)\n",
 935                                 task->tk_pid, task->tk_status);
 936
 937         status = task->tk_status;
 938         if (status >= 0) {
 939                 task->tk_action = call_decode;
 940                 return;
 941         }
 942
 943         task->tk_status = 0;
 944         switch(status) {
 945         case -ETIMEDOUT:
 946                 task->tk_action = call_timeout;
 947                 break;
 948         case -ECONNREFUSED:
 949         case -ENOTCONN:
 950                 rpc_force_rebind(clnt);
 951                 task->tk_action = call_bind;
 952                 break;
 953         case -EAGAIN:
 954                 task->tk_action = call_transmit;
 955                 break;
 956         case -EIO:
 957                 /* shutdown or soft timeout */
 958                 rpc_exit(task, status);
 959                 break;
 960         default:
 961                 printk("%s: RPC call returned error %d\n",
 962                                clnt->cl_protname, -status);
 963                 rpc_exit(task, status);
 964                 break;
 965         }
 966 }
 967
 968 /*
 969  * 6a.  Handle transmission errors.
 970  */
 971 static void
 972 call_transmit_status(struct rpc_task *task)
 973 {
 974         if (task->tk_status != -EAGAIN)
 975                 rpc_task_force_reencode(task);
 976         call_status(task);
 977 }
 978
 979 /*
 980  * 6b.  Handle RPC timeout
 981  *      We do not release the request slot, so we keep using the
 982  *      same XID for all retransmits.
 983  */
 984 static void
 985 call_timeout(struct rpc_task *task)
 986 {
 987         struct rpc_clnt *clnt = task->tk_client;
 988
 989         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 990                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 991                 goto retry;
 992         }
 993
 994         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 995         if (RPC_IS_SOFT(task)) {
 996                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 997                                 clnt->cl_protname, clnt->cl_server);
 998                 rpc_exit(task, -EIO);
 999                 return;
1000         }
1001
1002         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1003                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1004                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1005                         clnt->cl_protname, clnt->cl_server);
1006         }
1007         rpc_force_rebind(clnt);
1008
1009 retry:
1010         clnt->cl_stats->rpcretrans++;
1011         task->tk_action = call_bind;
1012         task->tk_status = 0;
1013 }
1014
1015 /*
1016  * 7.   Decode the RPC reply
1017  */
1018 static void
1019 call_decode(struct rpc_task *task)
1020 {
1021         struct rpc_clnt *clnt = task->tk_client;
1022         struct rpc_rqst *req = task->tk_rqstp;
1023         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1024         u32             *p;
1025
1026         dprintk("RPC: %4d call_decode (status %d)\n",
1027                                 task->tk_pid, task->tk_status);
1028
1029         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1030                 printk(KERN_NOTICE "%s: server %s OK\n",
1031                         clnt->cl_protname, clnt->cl_server);
1032                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1033         }
1034
1035         if (task->tk_status < 12) {
1036                 if (!RPC_IS_SOFT(task)) {
1037                         task->tk_action = call_bind;
1038                         clnt->cl_stats->rpcretrans++;
1039                         goto out_retry;
1040                 }
1041                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1042                         clnt->cl_protname, task->tk_status);
1043                 rpc_exit(task, -EIO);
1044                 return;
1045         }
1046
1047         req->rq_rcv_buf.len = req->rq_private_buf.len;
1048
1049         /* Check that the softirq receive buffer is valid */
1050         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1051                                 sizeof(req->rq_rcv_buf)) != 0);
1052
1053         /* Verify the RPC header */
1054         p = call_verify(task);
1055         if (IS_ERR(p)) {
1056                 if (p == ERR_PTR(-EAGAIN))
1057                         goto out_retry;
1058                 return;
1059         }
1060
1061         task->tk_action = rpc_exit_task;
1062
1063         if (decode)
1064                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1065                                                       task->tk_msg.rpc_resp);
1066         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1067                                         task->tk_status);
1068         return;
1069 out_retry:
1070         req->rq_received = req->rq_private_buf.len = 0;
1071         task->tk_status = 0;
1072 }
1073
1074 /*
1075  * 8.   Refresh the credentials if rejected by the server
1076  */
1077 static void
1078 call_refresh(struct rpc_task *task)
1079 {
1080         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1081
1082         xprt_release(task);     /* Must do to obtain new XID */
1083         task->tk_action = call_refreshresult;
1084         task->tk_status = 0;
1085         task->tk_client->cl_stats->rpcauthrefresh++;
1086         rpcauth_refreshcred(task);
1087 }
1088
1089 /*
1090  * 8a.  Process the results of a credential refresh
1091  */
1092 static void
1093 call_refreshresult(struct rpc_task *task)
1094 {
1095         int status = task->tk_status;
1096         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1097                                 task->tk_pid, task->tk_status);
1098
1099         task->tk_status = 0;
1100         task->tk_action = call_reserve;
1101         if (status >= 0 && rpcauth_uptodatecred(task))
1102                 return;
1103         if (status == -EACCES) {
1104                 rpc_exit(task, -EACCES);
1105                 return;
1106         }
1107         task->tk_action = call_refresh;
1108         if (status != -ETIMEDOUT)
1109                 rpc_delay(task, 3*HZ);
1110         return;
1111 }
1112
1113 /*
1114  * Call header serialization
1115  */
1116 static u32 *
1117 call_header(struct rpc_task *task)
1118 {
1119         struct rpc_clnt *clnt = task->tk_client;
1120         struct rpc_rqst *req = task->tk_rqstp;
1121         u32             *p = req->rq_svec[0].iov_base;
1122
1123         /* FIXME: check buffer size? */
1124
1125         p = xprt_skip_transport_header(task->tk_xprt, p);
1126         *p++ = req->rq_xid;             /* XID */
1127         *p++ = htonl(RPC_CALL);         /* CALL */
1128         *p++ = htonl(RPC_VERSION);      /* RPC version */
1129         *p++ = htonl(clnt->cl_prog);    /* program number */
1130         *p++ = htonl(clnt->cl_vers);    /* program version */
1131         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1132         p = rpcauth_marshcred(task, p);
1133         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1134         return p;
1135 }
1136
1137 /*
1138  * Reply header verification
1139  */
1140 static u32 *
1141 call_verify(struct rpc_task *task)
1142 {
1143         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1144         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1145         u32     *p = iov->iov_base, n;
1146         int error = -EACCES;
1147
1148         if ((len -= 3) < 0)
1149                 goto out_overflow;
1150         p += 1; /* skip XID */
1151
1152         if ((n = ntohl(*p++)) != RPC_REPLY) {
1153                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1154                 goto out_garbage;
1155         }
1156         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1157                 if (--len < 0)
1158                         goto out_overflow;
1159                 switch ((n = ntohl(*p++))) {
1160                         case RPC_AUTH_ERROR:
1161                                 break;
1162                         case RPC_MISMATCH:
1163                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1164                                 error = -EPROTONOSUPPORT;
1165                                 goto out_err;
1166                         default:
1167                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1168                                 goto out_eio;
1169                 }
1170                 if (--len < 0)
1171                         goto out_overflow;
1172                 switch ((n = ntohl(*p++))) {
1173                 case RPC_AUTH_REJECTEDCRED:
1174                 case RPC_AUTH_REJECTEDVERF:
1175                 case RPCSEC_GSS_CREDPROBLEM:
1176                 case RPCSEC_GSS_CTXPROBLEM:
1177                         if (!task->tk_cred_retry)
1178                                 break;
1179                         task->tk_cred_retry--;
1180                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1181                                                         task->tk_pid);
1182                         rpcauth_invalcred(task);
1183                         task->tk_action = call_refresh;
1184                         goto out_retry;
1185                 case RPC_AUTH_BADCRED:
1186                 case RPC_AUTH_BADVERF:
1187                         /* possibly garbled cred/verf? */
1188                         if (!task->tk_garb_retry)
1189                                 break;
1190                         task->tk_garb_retry--;
1191                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1192                                                         task->tk_pid);
1193                         task->tk_action = call_bind;
1194                         goto out_retry;
1195                 case RPC_AUTH_TOOWEAK:
1196                         printk(KERN_NOTICE "call_verify: server requires stronger "
1197                                "authentication.\n");
1198                         break;
1199                 default:
1200                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1201                         error = -EIO;
1202                 }
1203                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1204                                                 task->tk_pid, n);
1205                 goto out_err;
1206         }
1207         if (!(p = rpcauth_checkverf(task, p))) {
1208                 printk(KERN_WARNING "call_verify: auth check failed\n");
1209                 goto out_garbage;               /* bad verifier, retry */
1210         }
1211         len = p - (u32 *)iov->iov_base - 1;
1212         if (len < 0)
1213                 goto out_overflow;
1214         switch ((n = ntohl(*p++))) {
1215         case RPC_SUCCESS:
1216                 return p;
1217         case RPC_PROG_UNAVAIL:
1218                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1219                                 (unsigned int)task->tk_client->cl_prog,
1220                                 task->tk_client->cl_server);
1221                 error = -EPFNOSUPPORT;
1222                 goto out_err;
1223         case RPC_PROG_MISMATCH:
1224                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1225                                 (unsigned int)task->tk_client->cl_prog,
1226                                 (unsigned int)task->tk_client->cl_vers,
1227                                 task->tk_client->cl_server);
1228                 error = -EPROTONOSUPPORT;
1229                 goto out_err;
1230         case RPC_PROC_UNAVAIL:
1231                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1232                                 task->tk_msg.rpc_proc,
1233                                 task->tk_client->cl_prog,
1234                                 task->tk_client->cl_vers,
1235                                 task->tk_client->cl_server);
1236                 error = -EOPNOTSUPP;
1237                 goto out_err;
1238         case RPC_GARBAGE_ARGS:
1239                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1240                 break;                  /* retry */
1241         default:
1242                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1243                 /* Also retry */
1244         }
1245
1246 out_garbage:
1247         task->tk_client->cl_stats->rpcgarbage++;
1248         if (task->tk_garb_retry) {
1249                 task->tk_garb_retry--;
1250                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1251                 task->tk_action = call_bind;
1252 out_retry:
1253                 return ERR_PTR(-EAGAIN);
1254         }
1255         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1256 out_eio:
1257         error = -EIO;
1258 out_err:
1259         rpc_exit(task, error);
1260         return ERR_PTR(error);
1261 out_overflow:
1262         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1263         goto out_garbage;
1264 }
1265
1266 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1267 {
1268         return 0;
1269 }
1270
1271 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1272 {
1273         return 0;
1274 }
1275
1276 static struct rpc_procinfo rpcproc_null = {
1277         .p_encode = rpcproc_encode_null,
1278         .p_decode = rpcproc_decode_null,
1279 };
1280
1281 int rpc_ping(struct rpc_clnt *clnt, int flags)
1282 {
1283         struct rpc_message msg = {
1284                 .rpc_proc = &rpcproc_null,
1285         };
1286         int err;
1287         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1288         err = rpc_call_sync(clnt, &msg, flags);
1289         put_rpccred(msg.rpc_cred);
1290         return err;
1291 }