net/sunrpc/clnt.c

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