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         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         wait_queue_t __wait;
 227         init_waitqueue_entry(&__wait, current);
 228         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 229                         clnt->cl_protname, clnt->cl_server,
 230                         atomic_read(&clnt->cl_users));
 231
 232         add_wait_queue(&destroy_wait, &__wait);
 233         set_current_state(TASK_UNINTERRUPTIBLE);
 234         while (atomic_read(&clnt->cl_users) > 0) {
 235                 /* Don't let rpc_release_client destroy us */
 236                 clnt->cl_oneshot = 0;
 237                 clnt->cl_dead = 0;
 238                 rpc_killall_tasks(clnt);
 239                 schedule_timeout(1*HZ);
 240                 set_current_state(TASK_UNINTERRUPTIBLE);
 241         }
 242         current->state = TASK_RUNNING;
 243         remove_wait_queue(&destroy_wait, &__wait);
 244
 245         if (atomic_read(&clnt->cl_users) < 0) {
 246                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 247                                 clnt, atomic_read(&clnt->cl_users));
 248 #ifdef RPC_DEBUG
 249                 rpc_show_tasks();
 250 #endif
 251                 BUG();
 252         }
 253
 254         return rpc_destroy_client(clnt);
 255 }
 256
 257 /*
 258  * Delete an RPC client
 259  */
 260 int
 261 rpc_destroy_client(struct rpc_clnt *clnt)
 262 {
 263         if (!atomic_dec_and_test(&clnt->cl_count))
 264                 return 1;
 265         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 266
 267         dprintk("RPC: destroying %s client for %s\n",
 268                         clnt->cl_protname, clnt->cl_server);
 269         if (clnt->cl_auth) {
 270                 rpcauth_destroy(clnt->cl_auth);
 271                 clnt->cl_auth = NULL;
 272         }
 273         if (clnt->cl_parent != clnt) {
 274                 rpc_destroy_client(clnt->cl_parent);
 275                 goto out_free;
 276         }
 277         if (clnt->cl_pathname[0])
 278                 rpc_rmdir(clnt->cl_pathname);
 279         if (clnt->cl_xprt) {
 280                 xprt_destroy(clnt->cl_xprt);
 281                 clnt->cl_xprt = NULL;
 282         }
 283         if (clnt->cl_server != clnt->cl_inline_name)
 284                 kfree(clnt->cl_server);
 285 out_free:
 286         kfree(clnt);
 287         return 0;
 288 }
 289
 290 /*
 291  * Release an RPC client
 292  */
 293 void
 294 rpc_release_client(struct rpc_clnt *clnt)
 295 {
 296         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 297                                 clnt, atomic_read(&clnt->cl_users));
 298
 299         if (!atomic_dec_and_test(&clnt->cl_users))
 300                 return;
 301         wake_up(&destroy_wait);
 302         if (clnt->cl_oneshot || clnt->cl_dead)
 303                 rpc_destroy_client(clnt);
 304 }
 305
 306 /*
 307  * Default callback for async RPC calls
 308  */
 309 static void
 310 rpc_default_callback(struct rpc_task *task)
 311 {
 312 }
 313
 314 /*
 315  *      Export the signal mask handling for aysnchronous code that
 316  *      sleeps on RPC calls
 317  */
 318
 319 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 320 {
 321         unsigned long   sigallow = sigmask(SIGKILL);
 322         unsigned long   irqflags;
 323
 324         /* Turn off various signals */
 325         if (clnt->cl_intr) {
 326                 struct k_sigaction *action = current->sighand->action;
 327                 if (action[SIGINT-1].sa.sa_handler == SIG_DFL)
 328                         sigallow |= sigmask(SIGINT);
 329                 if (action[SIGQUIT-1].sa.sa_handler == SIG_DFL)
 330                         sigallow |= sigmask(SIGQUIT);
 331         }
 332         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 333         *oldset = current->blocked;
 334         siginitsetinv(&current->blocked, sigallow & ~oldset->sig[0]);
 335         recalc_sigpending();
 336         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 337 }
 338
 339 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 340 {
 341         unsigned long   irqflags;
 342
 343         spin_lock_irqsave(&current->sighand->siglock, irqflags);
 344         current->blocked = *oldset;
 345         recalc_sigpending();
 346         spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 347 }
 348
 349 /*
 350  * New rpc_call implementation
 351  */
 352 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 353 {
 354         struct rpc_task *task;
 355         sigset_t        oldset;
 356         int             status;
 357
 358         /* If this client is slain all further I/O fails */
 359         if (clnt->cl_dead)
 360                 return -EIO;
 361
 362         BUG_ON(flags & RPC_TASK_ASYNC);
 363
 364         rpc_clnt_sigmask(clnt, &oldset);
 365
 366         status = -ENOMEM;
 367         task = rpc_new_task(clnt, NULL, flags);
 368         if (task == NULL)
 369                 goto out;
 370
 371         rpc_call_setup(task, msg, 0);
 372
 373         /* Set up the call info struct and execute the task */
 374         if (task->tk_status == 0)
 375                 status = rpc_execute(task);
 376         else {
 377                 status = task->tk_status;
 378                 rpc_release_task(task);
 379         }
 380
 381 out:
 382         rpc_clnt_sigunmask(clnt, &oldset);
 383
 384         return status;
 385 }
 386
 387 /*
 388  * New rpc_call implementation
 389  */
 390 int
 391 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 392                rpc_action callback, void *data)
 393 {
 394         struct rpc_task *task;
 395         sigset_t        oldset;
 396         int             status;
 397
 398         /* If this client is slain all further I/O fails */
 399         if (clnt->cl_dead)
 400                 return -EIO;
 401
 402         flags |= RPC_TASK_ASYNC;
 403
 404         rpc_clnt_sigmask(clnt, &oldset);
 405
 406         /* Create/initialize a new RPC task */
 407         if (!callback)
 408                 callback = rpc_default_callback;
 409         status = -ENOMEM;
 410         if (!(task = rpc_new_task(clnt, callback, flags)))
 411                 goto out;
 412         task->tk_calldata = data;
 413
 414         rpc_call_setup(task, msg, 0);
 415
 416         /* Set up the call info struct and execute the task */
 417         status = task->tk_status;
 418         if (status == 0)
 419                 rpc_execute(task);
 420         else
 421                 rpc_release_task(task);
 422
 423 out:
 424         rpc_clnt_sigunmask(clnt, &oldset);
 425
 426         return status;
 427 }
 428
 429
 430 void
 431 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 432 {
 433         task->tk_msg   = *msg;
 434         task->tk_flags |= flags;
 435         /* Bind the user cred */
 436         if (task->tk_msg.rpc_cred != NULL)
 437                 rpcauth_holdcred(task);
 438         else
 439                 rpcauth_bindcred(task);
 440
 441         if (task->tk_status == 0)
 442                 task->tk_action = call_start;
 443         else
 444                 task->tk_action = NULL;
 445 }
 446
 447 void
 448 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 449 {
 450         struct rpc_xprt *xprt = clnt->cl_xprt;
 451
 452         xprt->sndsize = 0;
 453         if (sndsize)
 454                 xprt->sndsize = sndsize + RPC_SLACK_SPACE;
 455         xprt->rcvsize = 0;
 456         if (rcvsize)
 457                 xprt->rcvsize = rcvsize + RPC_SLACK_SPACE;
 458         if (xprt_connected(xprt))
 459                 xprt_sock_setbufsize(xprt);
 460 }
 461
 462 /*
 463  * Return size of largest payload RPC client can support, in bytes
 464  *
 465  * For stream transports, this is one RPC record fragment (see RFC
 466  * 1831), as we don't support multi-record requests yet.  For datagram
 467  * transports, this is the size of an IP packet minus the IP, UDP, and
 468  * RPC header sizes.
 469  */
 470 size_t rpc_max_payload(struct rpc_clnt *clnt)
 471 {
 472         return clnt->cl_xprt->max_payload;
 473 }
 474 EXPORT_SYMBOL(rpc_max_payload);
 475
 476 /*
 477  * Restart an (async) RPC call. Usually called from within the
 478  * exit handler.
 479  */
 480 void
 481 rpc_restart_call(struct rpc_task *task)
 482 {
 483         if (RPC_ASSASSINATED(task))
 484                 return;
 485
 486         task->tk_action = call_start;
 487 }
 488
 489 /*
 490  * 0.  Initial state
 491  *
 492  *     Other FSM states can be visited zero or more times, but
 493  *     this state is visited exactly once for each RPC.
 494  */
 495 static void
 496 call_start(struct rpc_task *task)
 497 {
 498         struct rpc_clnt *clnt = task->tk_client;
 499
 500         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 501                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 502                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 503
 504         /* Increment call count */
 505         task->tk_msg.rpc_proc->p_count++;
 506         clnt->cl_stats->rpccnt++;
 507         task->tk_action = call_reserve;
 508 }
 509
 510 /*
 511  * 1.   Reserve an RPC call slot
 512  */
 513 static void
 514 call_reserve(struct rpc_task *task)
 515 {
 516         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 517
 518         if (!rpcauth_uptodatecred(task)) {
 519                 task->tk_action = call_refresh;
 520                 return;
 521         }
 522
 523         task->tk_status  = 0;
 524         task->tk_action  = call_reserveresult;
 525         xprt_reserve(task);
 526 }
 527
 528 /*
 529  * 1b.  Grok the result of xprt_reserve()
 530  */
 531 static void
 532 call_reserveresult(struct rpc_task *task)
 533 {
 534         int status = task->tk_status;
 535
 536         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 537                                 task->tk_pid, task->tk_status);
 538
 539         /*
 540          * After a call to xprt_reserve(), we must have either
 541          * a request slot or else an error status.
 542          */
 543         task->tk_status = 0;
 544         if (status >= 0) {
 545                 if (task->tk_rqstp) {
 546                         task->tk_action = call_allocate;
 547                         return;
 548                 }
 549
 550                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 551                                 __FUNCTION__, status);
 552                 rpc_exit(task, -EIO);
 553                 return;
 554         }
 555
 556         /*
 557          * Even though there was an error, we may have acquired
 558          * a request slot somehow.  Make sure not to leak it.
 559          */
 560         if (task->tk_rqstp) {
 561                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 562                                 __FUNCTION__, status);
 563                 xprt_release(task);
 564         }
 565
 566         switch (status) {
 567         case -EAGAIN:   /* woken up; retry */
 568                 task->tk_action = call_reserve;
 569                 return;
 570         case -EIO:      /* probably a shutdown */
 571                 break;
 572         default:
 573                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 574                                 __FUNCTION__, status);
 575                 break;
 576         }
 577         rpc_exit(task, status);
 578 }
 579
 580 /*
 581  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 582  *      (Note: buffer memory is freed in rpc_task_release).
 583  */
 584 static void
 585 call_allocate(struct rpc_task *task)
 586 {
 587         unsigned int    bufsiz;
 588
 589         dprintk("RPC: %4d call_allocate (status %d)\n",
 590                                 task->tk_pid, task->tk_status);
 591         task->tk_action = call_bind;
 592         if (task->tk_buffer)
 593                 return;
 594
 595         /* FIXME: compute buffer requirements more exactly using
 596          * auth->au_wslack */
 597         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 598
 599         if (rpc_malloc(task, bufsiz << 1) != NULL)
 600                 return;
 601         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 602
 603         if (RPC_IS_ASYNC(task) || !(task->tk_client->cl_intr && signalled())) {
 604                 xprt_release(task);
 605                 task->tk_action = call_reserve;
 606                 rpc_delay(task, HZ>>4);
 607                 return;
 608         }
 609
 610         rpc_exit(task, -ERESTARTSYS);
 611 }
 612
 613 /*
 614  * 3.   Encode arguments of an RPC call
 615  */
 616 static void
 617 call_encode(struct rpc_task *task)
 618 {
 619         struct rpc_clnt *clnt = task->tk_client;
 620         struct rpc_rqst *req = task->tk_rqstp;
 621         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 622         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 623         unsigned int    bufsiz;
 624         kxdrproc_t      encode;
 625         int             status;
 626         u32             *p;
 627
 628         dprintk("RPC: %4d call_encode (status %d)\n",
 629                                 task->tk_pid, task->tk_status);
 630
 631         /* Default buffer setup */
 632         bufsiz = task->tk_bufsize >> 1;
 633         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
 634         sndbuf->head[0].iov_len  = bufsiz;
 635         sndbuf->tail[0].iov_len  = 0;
 636         sndbuf->page_len         = 0;
 637         sndbuf->len              = 0;
 638         sndbuf->buflen           = bufsiz;
 639         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
 640         rcvbuf->head[0].iov_len  = bufsiz;
 641         rcvbuf->tail[0].iov_len  = 0;
 642         rcvbuf->page_len         = 0;
 643         rcvbuf->len              = 0;
 644         rcvbuf->buflen           = bufsiz;
 645
 646         /* Encode header and provided arguments */
 647         encode = task->tk_msg.rpc_proc->p_encode;
 648         if (!(p = call_header(task))) {
 649                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 650                 rpc_exit(task, -EIO);
 651                 return;
 652         }
 653         if (encode && (status = rpcauth_wrap_req(task, encode, req, p,
 654                                                  task->tk_msg.rpc_argp)) < 0) {
 655                 printk(KERN_WARNING "%s: can't encode arguments: %d\n",
 656                                 clnt->cl_protname, -status);
 657                 rpc_exit(task, status);
 658         }
 659 }
 660
 661 /*
 662  * 4.   Get the server port number if not yet set
 663  */
 664 static void
 665 call_bind(struct rpc_task *task)
 666 {
 667         struct rpc_clnt *clnt = task->tk_client;
 668         struct rpc_xprt *xprt = clnt->cl_xprt;
 669
 670         dprintk("RPC: %4d call_bind xprt %p %s connected\n", task->tk_pid,
 671                         xprt, (xprt_connected(xprt) ? "is" : "is not"));
 672
 673         task->tk_action = (xprt_connected(xprt)) ? call_transmit : call_connect;
 674
 675         if (!clnt->cl_port) {
 676                 task->tk_action = call_connect;
 677                 task->tk_timeout = RPC_CONNECT_TIMEOUT;
 678                 rpc_getport(task, clnt);
 679         }
 680 }
 681
 682 /*
 683  * 4a.  Connect to the RPC server (TCP case)
 684  */
 685 static void
 686 call_connect(struct rpc_task *task)
 687 {
 688         struct rpc_clnt *clnt = task->tk_client;
 689
 690         dprintk("RPC: %4d call_connect status %d\n",
 691                                 task->tk_pid, task->tk_status);
 692
 693         if (xprt_connected(clnt->cl_xprt)) {
 694                 task->tk_action = call_transmit;
 695                 return;
 696         }
 697         task->tk_action = call_connect_status;
 698         if (task->tk_status < 0)
 699                 return;
 700         xprt_connect(task);
 701 }
 702
 703 /*
 704  * 4b. Sort out connect result
 705  */
 706 static void
 707 call_connect_status(struct rpc_task *task)
 708 {
 709         struct rpc_clnt *clnt = task->tk_client;
 710         int status = task->tk_status;
 711
 712         task->tk_status = 0;
 713         if (status >= 0) {
 714                 clnt->cl_stats->netreconn++;
 715                 task->tk_action = call_transmit;
 716                 return;
 717         }
 718
 719         /* Something failed: we may have to rebind */
 720         if (clnt->cl_autobind)
 721                 clnt->cl_port = 0;
 722         switch (status) {
 723         case -ENOTCONN:
 724         case -ETIMEDOUT:
 725         case -EAGAIN:
 726                 task->tk_action = (clnt->cl_port == 0) ? call_bind : call_connect;
 727                 break;
 728         default:
 729                 rpc_exit(task, -EIO);
 730         }
 731 }
 732
 733 /*
 734  * 5.   Transmit the RPC request, and wait for reply
 735  */
 736 static void
 737 call_transmit(struct rpc_task *task)
 738 {
 739         dprintk("RPC: %4d call_transmit (status %d)\n",
 740                                 task->tk_pid, task->tk_status);
 741
 742         task->tk_action = call_status;
 743         if (task->tk_status < 0)
 744                 return;
 745         task->tk_status = xprt_prepare_transmit(task);
 746         if (task->tk_status != 0)
 747                 return;
 748         /* Encode here so that rpcsec_gss can use correct sequence number. */
 749         if (!task->tk_rqstp->rq_bytes_sent)
 750                 call_encode(task);
 751         if (task->tk_status < 0)
 752                 return;
 753         xprt_transmit(task);
 754         if (task->tk_status < 0)
 755                 return;
 756         if (!task->tk_msg.rpc_proc->p_decode) {
 757                 task->tk_action = NULL;
 758                 rpc_wake_up_task(task);
 759         }
 760 }
 761
 762 /*
 763  * 6.   Sort out the RPC call status
 764  */
 765 static void
 766 call_status(struct rpc_task *task)
 767 {
 768         struct rpc_clnt *clnt = task->tk_client;
 769         struct rpc_rqst *req = task->tk_rqstp;
 770         int             status;
 771
 772         if (req->rq_received > 0 && !req->rq_bytes_sent)
 773                 task->tk_status = req->rq_received;
 774
 775         dprintk("RPC: %4d call_status (status %d)\n",
 776                                 task->tk_pid, task->tk_status);
 777
 778         status = task->tk_status;
 779         if (status >= 0) {
 780                 task->tk_action = call_decode;
 781                 return;
 782         }
 783
 784         task->tk_status = 0;
 785         switch(status) {
 786         case -ETIMEDOUT:
 787                 task->tk_action = call_timeout;
 788                 break;
 789         case -ECONNREFUSED:
 790         case -ENOTCONN:
 791                 req->rq_bytes_sent = 0;
 792                 if (clnt->cl_autobind)
 793                         clnt->cl_port = 0;
 794                 task->tk_action = call_bind;
 795                 break;
 796         case -EAGAIN:
 797                 task->tk_action = call_transmit;
 798                 break;
 799         case -EIO:
 800                 /* shutdown or soft timeout */
 801                 rpc_exit(task, status);
 802                 break;
 803         default:
 804                 if (clnt->cl_chatty)
 805                         printk("%s: RPC call returned error %d\n",
 806                                clnt->cl_protname, -status);
 807                 rpc_exit(task, status);
 808                 break;
 809         }
 810 }
 811
 812 /*
 813  * 6a.  Handle RPC timeout
 814  *      We do not release the request slot, so we keep using the
 815  *      same XID for all retransmits.
 816  */
 817 static void
 818 call_timeout(struct rpc_task *task)
 819 {
 820         struct rpc_clnt *clnt = task->tk_client;
 821
 822         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 823                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 824                 goto retry;
 825         }
 826
 827         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 828         if (RPC_IS_SOFT(task)) {
 829                 if (clnt->cl_chatty)
 830                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
 831                                 clnt->cl_protname, clnt->cl_server);
 832                 rpc_exit(task, -EIO);
 833                 return;
 834         }
 835
 836         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
 837                 task->tk_flags |= RPC_CALL_MAJORSEEN;
 838                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
 839                         clnt->cl_protname, clnt->cl_server);
 840         }
 841         if (clnt->cl_autobind)
 842                 clnt->cl_port = 0;
 843
 844 retry:
 845         clnt->cl_stats->rpcretrans++;
 846         task->tk_action = call_bind;
 847         task->tk_status = 0;
 848 }
 849
 850 /*
 851  * 7.   Decode the RPC reply
 852  */
 853 static void
 854 call_decode(struct rpc_task *task)
 855 {
 856         struct rpc_clnt *clnt = task->tk_client;
 857         struct rpc_rqst *req = task->tk_rqstp;
 858         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
 859         u32             *p;
 860
 861         dprintk("RPC: %4d call_decode (status %d)\n",
 862                                 task->tk_pid, task->tk_status);
 863
 864         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
 865                 printk(KERN_NOTICE "%s: server %s OK\n",
 866                         clnt->cl_protname, clnt->cl_server);
 867                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
 868         }
 869
 870         if (task->tk_status < 12) {
 871                 if (!RPC_IS_SOFT(task)) {
 872                         task->tk_action = call_bind;
 873                         clnt->cl_stats->rpcretrans++;
 874                         goto out_retry;
 875                 }
 876                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
 877                         clnt->cl_protname, task->tk_status);
 878                 rpc_exit(task, -EIO);
 879                 return;
 880         }
 881
 882         req->rq_rcv_buf.len = req->rq_private_buf.len;
 883
 884         /* Check that the softirq receive buffer is valid */
 885         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
 886                                 sizeof(req->rq_rcv_buf)) != 0);
 887
 888         /* Verify the RPC header */
 889         if (!(p = call_verify(task))) {
 890                 if (task->tk_action == NULL)
 891                         return;
 892                 goto out_retry;
 893         }
 894
 895         task->tk_action = NULL;
 896
 897         if (decode)
 898                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
 899                                                       task->tk_msg.rpc_resp);
 900         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
 901                                         task->tk_status);
 902         return;
 903 out_retry:
 904         req->rq_received = req->rq_private_buf.len = 0;
 905         task->tk_status = 0;
 906 }
 907
 908 /*
 909  * 8.   Refresh the credentials if rejected by the server
 910  */
 911 static void
 912 call_refresh(struct rpc_task *task)
 913 {
 914         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
 915
 916         xprt_release(task);     /* Must do to obtain new XID */
 917         task->tk_action = call_refreshresult;
 918         task->tk_status = 0;
 919         task->tk_client->cl_stats->rpcauthrefresh++;
 920         rpcauth_refreshcred(task);
 921 }
 922
 923 /*
 924  * 8a.  Process the results of a credential refresh
 925  */
 926 static void
 927 call_refreshresult(struct rpc_task *task)
 928 {
 929         int status = task->tk_status;
 930         dprintk("RPC: %4d call_refreshresult (status %d)\n",
 931                                 task->tk_pid, task->tk_status);
 932
 933         task->tk_status = 0;
 934         task->tk_action = call_reserve;
 935         if (status >= 0 && rpcauth_uptodatecred(task))
 936                 return;
 937         if (status == -EACCES) {
 938                 rpc_exit(task, -EACCES);
 939                 return;
 940         }
 941         task->tk_action = call_refresh;
 942         if (status != -ETIMEDOUT)
 943                 rpc_delay(task, 3*HZ);
 944         return;
 945 }
 946
 947 /*
 948  * Call header serialization
 949  */
 950 static u32 *
 951 call_header(struct rpc_task *task)
 952 {
 953         struct rpc_clnt *clnt = task->tk_client;
 954         struct rpc_xprt *xprt = clnt->cl_xprt;
 955         struct rpc_rqst *req = task->tk_rqstp;
 956         u32             *p = req->rq_svec[0].iov_base;
 957
 958         /* FIXME: check buffer size? */
 959         if (xprt->stream)
 960                 *p++ = 0;               /* fill in later */
 961         *p++ = req->rq_xid;             /* XID */
 962         *p++ = htonl(RPC_CALL);         /* CALL */
 963         *p++ = htonl(RPC_VERSION);      /* RPC version */
 964         *p++ = htonl(clnt->cl_prog);    /* program number */
 965         *p++ = htonl(clnt->cl_vers);    /* program version */
 966         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
 967         return rpcauth_marshcred(task, p);
 968 }
 969
 970 /*
 971  * Reply header verification
 972  */
 973 static u32 *
 974 call_verify(struct rpc_task *task)
 975 {
 976         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
 977         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
 978         u32     *p = iov->iov_base, n;
 979         int error = -EACCES;
 980
 981         if ((len -= 3) < 0)
 982                 goto out_overflow;
 983         p += 1; /* skip XID */
 984
 985         if ((n = ntohl(*p++)) != RPC_REPLY) {
 986                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
 987                 goto out_retry;
 988         }
 989         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
 990                 if (--len < 0)
 991                         goto out_overflow;
 992                 switch ((n = ntohl(*p++))) {
 993                         case RPC_AUTH_ERROR:
 994                                 break;
 995                         case RPC_MISMATCH:
 996                                 printk(KERN_WARNING "%s: RPC call version mismatch!\n", __FUNCTION__);
 997                                 goto out_eio;
 998                         default:
 999                                 printk(KERN_WARNING "%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1000                                 goto out_eio;
1001                 }
1002                 if (--len < 0)
1003                         goto out_overflow;
1004                 switch ((n = ntohl(*p++))) {
1005                 case RPC_AUTH_REJECTEDCRED:
1006                 case RPC_AUTH_REJECTEDVERF:
1007                 case RPCSEC_GSS_CREDPROBLEM:
1008                 case RPCSEC_GSS_CTXPROBLEM:
1009                         if (!task->tk_cred_retry)
1010                                 break;
1011                         task->tk_cred_retry--;
1012                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1013                                                         task->tk_pid);
1014                         rpcauth_invalcred(task);
1015                         task->tk_action = call_refresh;
1016                         return NULL;
1017                 case RPC_AUTH_BADCRED:
1018                 case RPC_AUTH_BADVERF:
1019                         /* possibly garbled cred/verf? */
1020                         if (!task->tk_garb_retry)
1021                                 break;
1022                         task->tk_garb_retry--;
1023                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1024                                                         task->tk_pid);
1025                         task->tk_action = call_bind;
1026                         return NULL;
1027                 case RPC_AUTH_TOOWEAK:
1028                         printk(KERN_NOTICE "call_verify: server requires stronger "
1029                                "authentication.\n");
1030                         break;
1031                 default:
1032                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1033                         error = -EIO;
1034                 }
1035                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1036                                                 task->tk_pid, n);
1037                 goto out_err;
1038         }
1039         if (!(p = rpcauth_checkverf(task, p))) {
1040                 printk(KERN_WARNING "call_verify: auth check failed\n");
1041                 goto out_retry;         /* bad verifier, retry */
1042         }
1043         len = p - (u32 *)iov->iov_base - 1;
1044         if (len < 0)
1045                 goto out_overflow;
1046         switch ((n = ntohl(*p++))) {
1047         case RPC_SUCCESS:
1048                 return p;
1049         case RPC_PROG_UNAVAIL:
1050                 printk(KERN_WARNING "RPC: call_verify: program %u is unsupported by server %s\n",
1051                                 (unsigned int)task->tk_client->cl_prog,
1052                                 task->tk_client->cl_server);
1053                 goto out_eio;
1054         case RPC_PROG_MISMATCH:
1055                 printk(KERN_WARNING "RPC: call_verify: program %u, version %u unsupported by server %s\n",
1056                                 (unsigned int)task->tk_client->cl_prog,
1057                                 (unsigned int)task->tk_client->cl_vers,
1058                                 task->tk_client->cl_server);
1059                 goto out_eio;
1060         case RPC_PROC_UNAVAIL:
1061                 printk(KERN_WARNING "RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1062                                 task->tk_msg.rpc_proc,
1063                                 task->tk_client->cl_prog,
1064                                 task->tk_client->cl_vers,
1065                                 task->tk_client->cl_server);
1066                 goto out_eio;
1067         case RPC_GARBAGE_ARGS:
1068                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1069                 break;                  /* retry */
1070         default:
1071                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1072                 /* Also retry */
1073         }
1074
1075 out_retry:
1076         task->tk_client->cl_stats->rpcgarbage++;
1077         if (task->tk_garb_retry) {
1078                 task->tk_garb_retry--;
1079                 dprintk(KERN_WARNING "RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1080                 task->tk_action = call_bind;
1081                 return NULL;
1082         }
1083         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1084 out_eio:
1085         error = -EIO;
1086 out_err:
1087         rpc_exit(task, error);
1088         return NULL;
1089 out_overflow:
1090         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1091         goto out_retry;
1092 }