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