net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/utsname.h>
  31
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sunrpc/rpc_pipe_fs.h>
  35
  36 #include <linux/nfs.h>
  37
  38
  39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
  40
  41 #ifdef RPC_DEBUG
  42 # define RPCDBG_FACILITY        RPCDBG_CALL
  43 #endif
  44
  45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  46
  47
  48 static void     call_start(struct rpc_task *task);
  49 static void     call_reserve(struct rpc_task *task);
  50 static void     call_reserveresult(struct rpc_task *task);
  51 static void     call_allocate(struct rpc_task *task);
  52 static void     call_encode(struct rpc_task *task);
  53 static void     call_decode(struct rpc_task *task);
  54 static void     call_bind(struct rpc_task *task);
  55 static void     call_bind_status(struct rpc_task *task);
  56 static void     call_transmit(struct rpc_task *task);
  57 static void     call_status(struct rpc_task *task);
  58 static void     call_transmit_status(struct rpc_task *task);
  59 static void     call_refresh(struct rpc_task *task);
  60 static void     call_refreshresult(struct rpc_task *task);
  61 static void     call_timeout(struct rpc_task *task);
  62 static void     call_connect(struct rpc_task *task);
  63 static void     call_connect_status(struct rpc_task *task);
  64 static u32 *    call_header(struct rpc_task *task);
  65 static u32 *    call_verify(struct rpc_task *task);
  66
  67
  68 static int
  69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  70 {
  71         static uint32_t clntid;
  72         int error;
  73
  74         if (dir_name == NULL)
  75                 return 0;
  76         for (;;) {
  77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
  78                                 "%s/clnt%x", dir_name,
  79                                 (unsigned int)clntid++);
  80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
  81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
  82                 if (!IS_ERR(clnt->cl_dentry))
  83                         return 0;
  84                 error = PTR_ERR(clnt->cl_dentry);
  85                 if (error != -EEXIST) {
  86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
  87                                         clnt->cl_pathname, error);
  88                         return error;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Create an RPC client
  95  * FIXME: This should also take a flags argument (as in task->tk_flags).
  96  * It's called (among others) from pmap_create_client, which may in
  97  * turn be called by an async task. In this case, rpciod should not be
  98  * made to sleep too long.
  99  */
 100 struct rpc_clnt *
 101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
 102                   struct rpc_program *program, u32 vers,
 103                   rpc_authflavor_t flavor)
 104 {
 105         struct rpc_version      *version;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct rpc_auth         *auth;
 108         int err;
 109         int len;
 110
 111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
 112                 program->name, servname, xprt);
 113
 114         err = -EINVAL;
 115         if (!xprt)
 116                 goto out_no_xprt;
 117         if (vers >= program->nrvers || !(version = program->version[vers]))
 118                 goto out_err;
 119
 120         err = -ENOMEM;
 121         clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
 122         if (!clnt)
 123                 goto out_err;
 124         memset(clnt, 0, sizeof(*clnt));
 125         atomic_set(&clnt->cl_users, 0);
 126         atomic_set(&clnt->cl_count, 1);
 127         clnt->cl_parent = clnt;
 128
 129         clnt->cl_server = clnt->cl_inline_name;
 130         len = strlen(servname) + 1;
 131         if (len > sizeof(clnt->cl_inline_name)) {
 132                 char *buf = kmalloc(len, GFP_KERNEL);
 133                 if (buf != 0)
 134                         clnt->cl_server = buf;
 135                 else
 136                         len = sizeof(clnt->cl_inline_name);
 137         }
 138         strlcpy(clnt->cl_server, servname, len);
 139
 140         clnt->cl_xprt     = xprt;
 141         clnt->cl_procinfo = version->procs;
 142         clnt->cl_maxproc  = version->nrprocs;
 143         clnt->cl_protname = program->name;
 144         clnt->cl_pmap     = &clnt->cl_pmap_default;
 145         clnt->cl_port     = xprt->addr.sin_port;
 146         clnt->cl_prog     = program->number;
 147         clnt->cl_vers     = version->number;
 148         clnt->cl_prot     = xprt->prot;
 149         clnt->cl_stats    = program->stats;
 150         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
 151
 152         if (!clnt->cl_port)
 153                 clnt->cl_autobind = 1;
 154
 155         clnt->cl_rtt = &clnt->cl_rtt_default;
 156         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 157
 158         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 159         if (err < 0)
 160                 goto out_no_path;
 161
 162         auth = rpcauth_create(flavor, clnt);
 163         if (IS_ERR(auth)) {
 164                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 165                                 flavor);
 166                 err = PTR_ERR(auth);
 167                 goto out_no_auth;
 168         }
 169
 170         /* save the nodename */
 171         clnt->cl_nodelen = strlen(system_utsname.nodename);
 172         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 173                 clnt->cl_nodelen = UNX_MAXNODENAME;
 174         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
 175         return clnt;
 176
 177 out_no_auth:
 178         rpc_rmdir(clnt->cl_pathname);
 179 out_no_path:
 180         if (clnt->cl_server != clnt->cl_inline_name)
 181                 kfree(clnt->cl_server);
 182         kfree(clnt);
 183 out_err:
 184         xprt_destroy(xprt);
 185 out_no_xprt:
 186         return ERR_PTR(err);
 187 }
 188
 189 /**
 190  * Create an RPC client
 191  * @xprt - pointer to xprt struct
 192  * @servname - name of server
 193  * @info - rpc_program
 194  * @version - rpc_program version
 195  * @authflavor - rpc_auth flavour to use
 196  *
 197  * Creates an RPC client structure, then pings the server in order to
 198  * determine if it is up, and if it supports this program and version.
 199  *
 200  * This function should never be called by asynchronous tasks such as
 201  * the portmapper.
 202  */
 203 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
 204                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
 205 {
 206         struct rpc_clnt *clnt;
 207         int err;
 208
 209         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
 210         if (IS_ERR(clnt))
 211                 return clnt;
 212         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 213         if (err == 0)
 214                 return clnt;
 215         rpc_shutdown_client(clnt);
 216         return ERR_PTR(err);
 217 }
 218
 219 /*
 220  * This function clones the RPC client structure. It allows us to share the
 221  * same transport while varying parameters such as the authentication
 222  * flavour.
 223  */
 224 struct rpc_clnt *
 225 rpc_clone_client(struct rpc_clnt *clnt)
 226 {
 227         struct rpc_clnt *new;
 228
 229         new = kmalloc(sizeof(*new), GFP_KERNEL);
 230         if (!new)
 231                 goto out_no_clnt;
 232         memcpy(new, clnt, sizeof(*new));
 233         atomic_set(&new->cl_count, 1);
 234         atomic_set(&new->cl_users, 0);
 235         new->cl_parent = clnt;
 236         atomic_inc(&clnt->cl_count);
 237         /* Duplicate portmapper */
 238         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 239         /* Turn off autobind on clones */
 240         new->cl_autobind = 0;
 241         new->cl_oneshot = 0;
 242         new->cl_dead = 0;
 243         dget(new->cl_dentry);
 244         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 245         if (new->cl_auth)
 246                 atomic_inc(&new->cl_auth->au_count);
 247         new->cl_pmap            = &new->cl_pmap_default;
 248         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 249         return new;
 250 out_no_clnt:
 251         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
 252         return ERR_PTR(-ENOMEM);
 253 }
 254
 255 /*
 256  * Properly shut down an RPC client, terminating all outstanding
 257  * requests. Note that we must be certain that cl_oneshot and
 258  * cl_dead are cleared, or else the client would be destroyed
 259  * when the last task releases it.
 260  */
 261 int
 262 rpc_shutdown_client(struct rpc_clnt *clnt)
 263 {
 264         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
 265                         clnt->cl_protname, clnt->cl_server,
 266                         atomic_read(&clnt->cl_users));
 267
 268         while (atomic_read(&clnt->cl_users) > 0) {
 269                 /* Don't let rpc_release_client destroy us */
 270                 clnt->cl_oneshot = 0;
 271                 clnt->cl_dead = 0;
 272                 rpc_killall_tasks(clnt);
 273                 wait_event_timeout(destroy_wait,
 274                         !atomic_read(&clnt->cl_users), 1*HZ);
 275         }
 276
 277         if (atomic_read(&clnt->cl_users) < 0) {
 278                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
 279                                 clnt, atomic_read(&clnt->cl_users));
 280 #ifdef RPC_DEBUG
 281                 rpc_show_tasks();
 282 #endif
 283                 BUG();
 284         }
 285
 286         return rpc_destroy_client(clnt);
 287 }
 288
 289 /*
 290  * Delete an RPC client
 291  */
 292 int
 293 rpc_destroy_client(struct rpc_clnt *clnt)
 294 {
 295         if (!atomic_dec_and_test(&clnt->cl_count))
 296                 return 1;
 297         BUG_ON(atomic_read(&clnt->cl_users) != 0);
 298
 299         dprintk("RPC: destroying %s client for %s\n",
 300                         clnt->cl_protname, clnt->cl_server);
 301         if (clnt->cl_auth) {
 302                 rpcauth_destroy(clnt->cl_auth);
 303                 clnt->cl_auth = NULL;
 304         }
 305         if (clnt->cl_parent != clnt) {
 306                 rpc_destroy_client(clnt->cl_parent);
 307                 goto out_free;
 308         }
 309         if (clnt->cl_pathname[0])
 310                 rpc_rmdir(clnt->cl_pathname);
 311         if (clnt->cl_xprt) {
 312                 xprt_destroy(clnt->cl_xprt);
 313                 clnt->cl_xprt = NULL;
 314         }
 315         if (clnt->cl_server != clnt->cl_inline_name)
 316                 kfree(clnt->cl_server);
 317 out_free:
 318         if (clnt->cl_dentry)
 319                 dput(clnt->cl_dentry);
 320         kfree(clnt);
 321         return 0;
 322 }
 323
 324 /*
 325  * Release an RPC client
 326  */
 327 void
 328 rpc_release_client(struct rpc_clnt *clnt)
 329 {
 330         dprintk("RPC:      rpc_release_client(%p, %d)\n",
 331                                 clnt, atomic_read(&clnt->cl_users));
 332
 333         if (!atomic_dec_and_test(&clnt->cl_users))
 334                 return;
 335         wake_up(&destroy_wait);
 336         if (clnt->cl_oneshot || clnt->cl_dead)
 337                 rpc_destroy_client(clnt);
 338 }
 339
 340 /**
 341  * rpc_bind_new_program - bind a new RPC program to an existing client
 342  * @old - old rpc_client
 343  * @program - rpc program to set
 344  * @vers - rpc program version
 345  *
 346  * Clones the rpc client and sets up a new RPC program. This is mainly
 347  * of use for enabling different RPC programs to share the same transport.
 348  * The Sun NFSv2/v3 ACL protocol can do this.
 349  */
 350 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 351                                       struct rpc_program *program,
 352                                       int vers)
 353 {
 354         struct rpc_clnt *clnt;
 355         struct rpc_version *version;
 356         int err;
 357
 358         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 359         version = program->version[vers];
 360         clnt = rpc_clone_client(old);
 361         if (IS_ERR(clnt))
 362                 goto out;
 363         clnt->cl_procinfo = version->procs;
 364         clnt->cl_maxproc  = version->nrprocs;
 365         clnt->cl_protname = program->name;
 366         clnt->cl_prog     = program->number;
 367         clnt->cl_vers     = version->number;
 368         clnt->cl_stats    = program->stats;
 369         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 370         if (err != 0) {
 371                 rpc_shutdown_client(clnt);
 372                 clnt = ERR_PTR(err);
 373         }
 374 out:
 375         return clnt;
 376 }
 377
 378 /*
 379  * Default callback for async RPC calls
 380  */
 381 static void
 382 rpc_default_callback(struct rpc_task *task, void *data)
 383 {
 384 }
 385
 386 static const struct rpc_call_ops rpc_default_ops = {
 387         .rpc_call_done = rpc_default_callback,
 388 };
 389
 390 /*
 391  *      Export the signal mask handling for synchronous code that
 392  *      sleeps on RPC calls
 393  */
 394 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 395
 396 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 397 {
 398         unsigned long   sigallow = sigmask(SIGKILL);
 399         sigset_t sigmask;
 400
 401         /* Block all signals except those listed in sigallow */
 402         if (intr)
 403                 sigallow |= RPC_INTR_SIGNALS;
 404         siginitsetinv(&sigmask, sigallow);
 405         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 406 }
 407
 408 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 409 {
 410         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 411 }
 412
 413 static inline void rpc_restore_sigmask(sigset_t *oldset)
 414 {
 415         sigprocmask(SIG_SETMASK, oldset, NULL);
 416 }
 417
 418 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 419 {
 420         rpc_save_sigmask(oldset, clnt->cl_intr);
 421 }
 422
 423 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 424 {
 425         rpc_restore_sigmask(oldset);
 426 }
 427
 428 /*
 429  * New rpc_call implementation
 430  */
 431 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 432 {
 433         struct rpc_task *task;
 434         sigset_t        oldset;
 435         int             status;
 436
 437         /* If this client is slain all further I/O fails */
 438         if (clnt->cl_dead)
 439                 return -EIO;
 440
 441         BUG_ON(flags & RPC_TASK_ASYNC);
 442
 443         status = -ENOMEM;
 444         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 445         if (task == NULL)
 446                 goto out;
 447
 448         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 449         rpc_task_sigmask(task, &oldset);
 450
 451         rpc_call_setup(task, msg, 0);
 452
 453         /* Set up the call info struct and execute the task */
 454         status = task->tk_status;
 455         if (status == 0) {
 456                 atomic_inc(&task->tk_count);
 457                 status = rpc_execute(task);
 458                 if (status == 0)
 459                         status = task->tk_status;
 460         }
 461         rpc_restore_sigmask(&oldset);
 462         rpc_release_task(task);
 463 out:
 464         return status;
 465 }
 466
 467 /*
 468  * New rpc_call implementation
 469  */
 470 int
 471 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 472                const struct rpc_call_ops *tk_ops, void *data)
 473 {
 474         struct rpc_task *task;
 475         sigset_t        oldset;
 476         int             status;
 477
 478         /* If this client is slain all further I/O fails */
 479         if (clnt->cl_dead)
 480                 return -EIO;
 481
 482         flags |= RPC_TASK_ASYNC;
 483
 484         /* Create/initialize a new RPC task */
 485         status = -ENOMEM;
 486         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 487                 goto out;
 488
 489         /* Mask signals on GSS_AUTH upcalls */
 490         rpc_task_sigmask(task, &oldset);
 491
 492         rpc_call_setup(task, msg, 0);
 493
 494         /* Set up the call info struct and execute the task */
 495         status = task->tk_status;
 496         if (status == 0)
 497                 rpc_execute(task);
 498         else
 499                 rpc_release_task(task);
 500
 501         rpc_restore_sigmask(&oldset);
 502 out:
 503         return status;
 504 }
 505
 506
 507 void
 508 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 509 {
 510         task->tk_msg   = *msg;
 511         task->tk_flags |= flags;
 512         /* Bind the user cred */
 513         if (task->tk_msg.rpc_cred != NULL)
 514                 rpcauth_holdcred(task);
 515         else
 516                 rpcauth_bindcred(task);
 517
 518         if (task->tk_status == 0)
 519                 task->tk_action = call_start;
 520         else
 521                 task->tk_action = rpc_exit_task;
 522 }
 523
 524 void
 525 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 526 {
 527         struct rpc_xprt *xprt = clnt->cl_xprt;
 528         if (xprt->ops->set_buffer_size)
 529                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 530 }
 531
 532 /*
 533  * Return size of largest payload RPC client can support, in bytes
 534  *
 535  * For stream transports, this is one RPC record fragment (see RFC
 536  * 1831), as we don't support multi-record requests yet.  For datagram
 537  * transports, this is the size of an IP packet minus the IP, UDP, and
 538  * RPC header sizes.
 539  */
 540 size_t rpc_max_payload(struct rpc_clnt *clnt)
 541 {
 542         return clnt->cl_xprt->max_payload;
 543 }
 544 EXPORT_SYMBOL(rpc_max_payload);
 545
 546 /**
 547  * rpc_force_rebind - force transport to check that remote port is unchanged
 548  * @clnt: client to rebind
 549  *
 550  */
 551 void rpc_force_rebind(struct rpc_clnt *clnt)
 552 {
 553         if (clnt->cl_autobind)
 554                 clnt->cl_port = 0;
 555 }
 556 EXPORT_SYMBOL(rpc_force_rebind);
 557
 558 /*
 559  * Restart an (async) RPC call. Usually called from within the
 560  * exit handler.
 561  */
 562 void
 563 rpc_restart_call(struct rpc_task *task)
 564 {
 565         if (RPC_ASSASSINATED(task))
 566                 return;
 567
 568         task->tk_action = call_start;
 569 }
 570
 571 /*
 572  * 0.  Initial state
 573  *
 574  *     Other FSM states can be visited zero or more times, but
 575  *     this state is visited exactly once for each RPC.
 576  */
 577 static void
 578 call_start(struct rpc_task *task)
 579 {
 580         struct rpc_clnt *clnt = task->tk_client;
 581
 582         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
 583                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
 584                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
 585
 586         /* Increment call count */
 587         task->tk_msg.rpc_proc->p_count++;
 588         clnt->cl_stats->rpccnt++;
 589         task->tk_action = call_reserve;
 590 }
 591
 592 /*
 593  * 1.   Reserve an RPC call slot
 594  */
 595 static void
 596 call_reserve(struct rpc_task *task)
 597 {
 598         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
 599
 600         if (!rpcauth_uptodatecred(task)) {
 601                 task->tk_action = call_refresh;
 602                 return;
 603         }
 604
 605         task->tk_status  = 0;
 606         task->tk_action  = call_reserveresult;
 607         xprt_reserve(task);
 608 }
 609
 610 /*
 611  * 1b.  Grok the result of xprt_reserve()
 612  */
 613 static void
 614 call_reserveresult(struct rpc_task *task)
 615 {
 616         int status = task->tk_status;
 617
 618         dprintk("RPC: %4d call_reserveresult (status %d)\n",
 619                                 task->tk_pid, task->tk_status);
 620
 621         /*
 622          * After a call to xprt_reserve(), we must have either
 623          * a request slot or else an error status.
 624          */
 625         task->tk_status = 0;
 626         if (status >= 0) {
 627                 if (task->tk_rqstp) {
 628                         task->tk_action = call_allocate;
 629                         return;
 630                 }
 631
 632                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 633                                 __FUNCTION__, status);
 634                 rpc_exit(task, -EIO);
 635                 return;
 636         }
 637
 638         /*
 639          * Even though there was an error, we may have acquired
 640          * a request slot somehow.  Make sure not to leak it.
 641          */
 642         if (task->tk_rqstp) {
 643                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 644                                 __FUNCTION__, status);
 645                 xprt_release(task);
 646         }
 647
 648         switch (status) {
 649         case -EAGAIN:   /* woken up; retry */
 650                 task->tk_action = call_reserve;
 651                 return;
 652         case -EIO:      /* probably a shutdown */
 653                 break;
 654         default:
 655                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 656                                 __FUNCTION__, status);
 657                 break;
 658         }
 659         rpc_exit(task, status);
 660 }
 661
 662 /*
 663  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 664  *      (Note: buffer memory is freed in xprt_release).
 665  */
 666 static void
 667 call_allocate(struct rpc_task *task)
 668 {
 669         struct rpc_rqst *req = task->tk_rqstp;
 670         struct rpc_xprt *xprt = task->tk_xprt;
 671         unsigned int    bufsiz;
 672
 673         dprintk("RPC: %4d call_allocate (status %d)\n",
 674                                 task->tk_pid, task->tk_status);
 675         task->tk_action = call_bind;
 676         if (req->rq_buffer)
 677                 return;
 678
 679         /* FIXME: compute buffer requirements more exactly using
 680          * auth->au_wslack */
 681         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
 682
 683         if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
 684                 return;
 685         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
 686
 687         if (RPC_IS_ASYNC(task) || !signalled()) {
 688                 xprt_release(task);
 689                 task->tk_action = call_reserve;
 690                 rpc_delay(task, HZ>>4);
 691                 return;
 692         }
 693
 694         rpc_exit(task, -ERESTARTSYS);
 695 }
 696
 697 static inline int
 698 rpc_task_need_encode(struct rpc_task *task)
 699 {
 700         return task->tk_rqstp->rq_snd_buf.len == 0;
 701 }
 702
 703 static inline void
 704 rpc_task_force_reencode(struct rpc_task *task)
 705 {
 706         task->tk_rqstp->rq_snd_buf.len = 0;
 707 }
 708
 709 /*
 710  * 3.   Encode arguments of an RPC call
 711  */
 712 static void
 713 call_encode(struct rpc_task *task)
 714 {
 715         struct rpc_rqst *req = task->tk_rqstp;
 716         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 717         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 718         unsigned int    bufsiz;
 719         kxdrproc_t      encode;
 720         u32             *p;
 721
 722         dprintk("RPC: %4d call_encode (status %d)\n",
 723                                 task->tk_pid, task->tk_status);
 724
 725         /* Default buffer setup */
 726         bufsiz = req->rq_bufsize >> 1;
 727         sndbuf->head[0].iov_base = (void *)req->rq_buffer;
 728         sndbuf->head[0].iov_len  = bufsiz;
 729         sndbuf->tail[0].iov_len  = 0;
 730         sndbuf->page_len         = 0;
 731         sndbuf->len              = 0;
 732         sndbuf->buflen           = bufsiz;
 733         rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
 734         rcvbuf->head[0].iov_len  = bufsiz;
 735         rcvbuf->tail[0].iov_len  = 0;
 736         rcvbuf->page_len         = 0;
 737         rcvbuf->len              = 0;
 738         rcvbuf->buflen           = bufsiz;
 739
 740         /* Encode header and provided arguments */
 741         encode = task->tk_msg.rpc_proc->p_encode;
 742         if (!(p = call_header(task))) {
 743                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 744                 rpc_exit(task, -EIO);
 745                 return;
 746         }
 747         if (encode == NULL)
 748                 return;
 749
 750         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 751                         task->tk_msg.rpc_argp);
 752         if (task->tk_status == -ENOMEM) {
 753                 /* XXX: Is this sane? */
 754                 rpc_delay(task, 3*HZ);
 755                 task->tk_status = -EAGAIN;
 756         }
 757 }
 758
 759 /*
 760  * 4.   Get the server port number if not yet set
 761  */
 762 static void
 763 call_bind(struct rpc_task *task)
 764 {
 765         struct rpc_clnt *clnt = task->tk_client;
 766
 767         dprintk("RPC: %4d call_bind (status %d)\n",
 768                                 task->tk_pid, task->tk_status);
 769
 770         task->tk_action = call_connect;
 771         if (!clnt->cl_port) {
 772                 task->tk_action = call_bind_status;
 773                 task->tk_timeout = task->tk_xprt->bind_timeout;
 774                 rpc_getport(task, clnt);
 775         }
 776 }
 777
 778 /*
 779  * 4a.  Sort out bind result
 780  */
 781 static void
 782 call_bind_status(struct rpc_task *task)
 783 {
 784         int status = -EACCES;
 785
 786         if (task->tk_status >= 0) {
 787                 dprintk("RPC: %4d call_bind_status (status %d)\n",
 788                                         task->tk_pid, task->tk_status);
 789                 task->tk_status = 0;
 790                 task->tk_action = call_connect;
 791                 return;
 792         }
 793
 794         switch (task->tk_status) {
 795         case -EACCES:
 796                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
 797                                 task->tk_pid);
 798                 rpc_delay(task, 3*HZ);
 799                 goto retry_bind;
 800         case -ETIMEDOUT:
 801                 dprintk("RPC: %4d rpcbind request timed out\n",
 802                                 task->tk_pid);
 803                 if (RPC_IS_SOFT(task)) {
 804                         status = -EIO;
 805                         break;
 806                 }
 807                 goto retry_bind;
 808         case -EPFNOSUPPORT:
 809                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
 810                                 task->tk_pid);
 811                 break;
 812         case -EPROTONOSUPPORT:
 813                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
 814                                 task->tk_pid);
 815                 break;
 816         default:
 817                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
 818                                 task->tk_pid, -task->tk_status);
 819                 status = -EIO;
 820                 break;
 821         }
 822
 823         rpc_exit(task, status);
 824         return;
 825
 826 retry_bind:
 827         task->tk_status = 0;
 828         task->tk_action = call_bind;
 829         return;
 830 }
 831
 832 /*
 833  * 4b.  Connect to the RPC server
 834  */
 835 static void
 836 call_connect(struct rpc_task *task)
 837 {
 838         struct rpc_xprt *xprt = task->tk_xprt;
 839
 840         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
 841                         task->tk_pid, xprt,
 842                         (xprt_connected(xprt) ? "is" : "is not"));
 843
 844         task->tk_action = call_transmit;
 845         if (!xprt_connected(xprt)) {
 846                 task->tk_action = call_connect_status;
 847                 if (task->tk_status < 0)
 848                         return;
 849                 xprt_connect(task);
 850         }
 851 }
 852
 853 /*
 854  * 4c.  Sort out connect result
 855  */
 856 static void
 857 call_connect_status(struct rpc_task *task)
 858 {
 859         struct rpc_clnt *clnt = task->tk_client;
 860         int status = task->tk_status;
 861
 862         dprintk("RPC: %5u call_connect_status (status %d)\n",
 863                                 task->tk_pid, task->tk_status);
 864
 865         task->tk_status = 0;
 866         if (status >= 0) {
 867                 clnt->cl_stats->netreconn++;
 868                 task->tk_action = call_transmit;
 869                 return;
 870         }
 871
 872         /* Something failed: remote service port may have changed */
 873         rpc_force_rebind(clnt);
 874
 875         switch (status) {
 876         case -ENOTCONN:
 877         case -ETIMEDOUT:
 878         case -EAGAIN:
 879                 task->tk_action = call_bind;
 880                 break;
 881         default:
 882                 rpc_exit(task, -EIO);
 883                 break;
 884         }
 885 }
 886
 887 /*
 888  * 5.   Transmit the RPC request, and wait for reply
 889  */
 890 static void
 891 call_transmit(struct rpc_task *task)
 892 {
 893         dprintk("RPC: %4d call_transmit (status %d)\n",
 894                                 task->tk_pid, task->tk_status);
 895
 896         task->tk_action = call_status;
 897         if (task->tk_status < 0)
 898                 return;
 899         task->tk_status = xprt_prepare_transmit(task);
 900         if (task->tk_status != 0)
 901                 return;
 902         /* Encode here so that rpcsec_gss can use correct sequence number. */
 903         if (rpc_task_need_encode(task)) {
 904                 task->tk_rqstp->rq_bytes_sent = 0;
 905                 call_encode(task);
 906                 /* Did the encode result in an error condition? */
 907                 if (task->tk_status != 0)
 908                         goto out_nosend;
 909         }
 910         task->tk_action = call_transmit_status;
 911         xprt_transmit(task);
 912         if (task->tk_status < 0)
 913                 return;
 914         if (!task->tk_msg.rpc_proc->p_decode) {
 915                 task->tk_action = rpc_exit_task;
 916                 rpc_wake_up_task(task);
 917         }
 918         return;
 919 out_nosend:
 920         /* release socket write lock before attempting to handle error */
 921         xprt_abort_transmit(task);
 922         rpc_task_force_reencode(task);
 923 }
 924
 925 /*
 926  * 6.   Sort out the RPC call status
 927  */
 928 static void
 929 call_status(struct rpc_task *task)
 930 {
 931         struct rpc_clnt *clnt = task->tk_client;
 932         struct rpc_rqst *req = task->tk_rqstp;
 933         int             status;
 934
 935         if (req->rq_received > 0 && !req->rq_bytes_sent)
 936                 task->tk_status = req->rq_received;
 937
 938         dprintk("RPC: %4d call_status (status %d)\n",
 939                                 task->tk_pid, task->tk_status);
 940
 941         status = task->tk_status;
 942         if (status >= 0) {
 943                 task->tk_action = call_decode;
 944                 return;
 945         }
 946
 947         task->tk_status = 0;
 948         switch(status) {
 949         case -ETIMEDOUT:
 950                 task->tk_action = call_timeout;
 951                 break;
 952         case -ECONNREFUSED:
 953         case -ENOTCONN:
 954                 rpc_force_rebind(clnt);
 955                 task->tk_action = call_bind;
 956                 break;
 957         case -EAGAIN:
 958                 task->tk_action = call_transmit;
 959                 break;
 960         case -EIO:
 961                 /* shutdown or soft timeout */
 962                 rpc_exit(task, status);
 963                 break;
 964         default:
 965                 printk("%s: RPC call returned error %d\n",
 966                                clnt->cl_protname, -status);
 967                 rpc_exit(task, status);
 968                 break;
 969         }
 970 }
 971
 972 /*
 973  * 6a.  Handle transmission errors.
 974  */
 975 static void
 976 call_transmit_status(struct rpc_task *task)
 977 {
 978         if (task->tk_status != -EAGAIN)
 979                 rpc_task_force_reencode(task);
 980         call_status(task);
 981 }
 982
 983 /*
 984  * 6b.  Handle RPC timeout
 985  *      We do not release the request slot, so we keep using the
 986  *      same XID for all retransmits.
 987  */
 988 static void
 989 call_timeout(struct rpc_task *task)
 990 {
 991         struct rpc_clnt *clnt = task->tk_client;
 992
 993         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
 994                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
 995                 goto retry;
 996         }
 997
 998         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
 999         if (RPC_IS_SOFT(task)) {
1000                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1001                                 clnt->cl_protname, clnt->cl_server);
1002                 rpc_exit(task, -EIO);
1003                 return;
1004         }
1005
1006         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1007                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1008                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1009                         clnt->cl_protname, clnt->cl_server);
1010         }
1011         rpc_force_rebind(clnt);
1012
1013 retry:
1014         clnt->cl_stats->rpcretrans++;
1015         task->tk_action = call_bind;
1016         task->tk_status = 0;
1017 }
1018
1019 /*
1020  * 7.   Decode the RPC reply
1021  */
1022 static void
1023 call_decode(struct rpc_task *task)
1024 {
1025         struct rpc_clnt *clnt = task->tk_client;
1026         struct rpc_rqst *req = task->tk_rqstp;
1027         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1028         u32             *p;
1029
1030         dprintk("RPC: %4d call_decode (status %d)\n",
1031                                 task->tk_pid, task->tk_status);
1032
1033         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1034                 printk(KERN_NOTICE "%s: server %s OK\n",
1035                         clnt->cl_protname, clnt->cl_server);
1036                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1037         }
1038
1039         if (task->tk_status < 12) {
1040                 if (!RPC_IS_SOFT(task)) {
1041                         task->tk_action = call_bind;
1042                         clnt->cl_stats->rpcretrans++;
1043                         goto out_retry;
1044                 }
1045                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1046                         clnt->cl_protname, task->tk_status);
1047                 rpc_exit(task, -EIO);
1048                 return;
1049         }
1050
1051         req->rq_rcv_buf.len = req->rq_private_buf.len;
1052
1053         /* Check that the softirq receive buffer is valid */
1054         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1055                                 sizeof(req->rq_rcv_buf)) != 0);
1056
1057         /* Verify the RPC header */
1058         p = call_verify(task);
1059         if (IS_ERR(p)) {
1060                 if (p == ERR_PTR(-EAGAIN))
1061                         goto out_retry;
1062                 return;
1063         }
1064
1065         task->tk_action = rpc_exit_task;
1066
1067         if (decode)
1068                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1069                                                       task->tk_msg.rpc_resp);
1070         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1071                                         task->tk_status);
1072         return;
1073 out_retry:
1074         req->rq_received = req->rq_private_buf.len = 0;
1075         task->tk_status = 0;
1076 }
1077
1078 /*
1079  * 8.   Refresh the credentials if rejected by the server
1080  */
1081 static void
1082 call_refresh(struct rpc_task *task)
1083 {
1084         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1085
1086         xprt_release(task);     /* Must do to obtain new XID */
1087         task->tk_action = call_refreshresult;
1088         task->tk_status = 0;
1089         task->tk_client->cl_stats->rpcauthrefresh++;
1090         rpcauth_refreshcred(task);
1091 }
1092
1093 /*
1094  * 8a.  Process the results of a credential refresh
1095  */
1096 static void
1097 call_refreshresult(struct rpc_task *task)
1098 {
1099         int status = task->tk_status;
1100         dprintk("RPC: %4d call_refreshresult (status %d)\n",
1101                                 task->tk_pid, task->tk_status);
1102
1103         task->tk_status = 0;
1104         task->tk_action = call_reserve;
1105         if (status >= 0 && rpcauth_uptodatecred(task))
1106                 return;
1107         if (status == -EACCES) {
1108                 rpc_exit(task, -EACCES);
1109                 return;
1110         }
1111         task->tk_action = call_refresh;
1112         if (status != -ETIMEDOUT)
1113                 rpc_delay(task, 3*HZ);
1114         return;
1115 }
1116
1117 /*
1118  * Call header serialization
1119  */
1120 static u32 *
1121 call_header(struct rpc_task *task)
1122 {
1123         struct rpc_clnt *clnt = task->tk_client;
1124         struct rpc_rqst *req = task->tk_rqstp;
1125         u32             *p = req->rq_svec[0].iov_base;
1126
1127         /* FIXME: check buffer size? */
1128
1129         p = xprt_skip_transport_header(task->tk_xprt, p);
1130         *p++ = req->rq_xid;             /* XID */
1131         *p++ = htonl(RPC_CALL);         /* CALL */
1132         *p++ = htonl(RPC_VERSION);      /* RPC version */
1133         *p++ = htonl(clnt->cl_prog);    /* program number */
1134         *p++ = htonl(clnt->cl_vers);    /* program version */
1135         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1136         p = rpcauth_marshcred(task, p);
1137         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1138         return p;
1139 }
1140
1141 /*
1142  * Reply header verification
1143  */
1144 static u32 *
1145 call_verify(struct rpc_task *task)
1146 {
1147         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1148         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1149         u32     *p = iov->iov_base, n;
1150         int error = -EACCES;
1151
1152         if ((len -= 3) < 0)
1153                 goto out_overflow;
1154         p += 1; /* skip XID */
1155
1156         if ((n = ntohl(*p++)) != RPC_REPLY) {
1157                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1158                 goto out_garbage;
1159         }
1160         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1161                 if (--len < 0)
1162                         goto out_overflow;
1163                 switch ((n = ntohl(*p++))) {
1164                         case RPC_AUTH_ERROR:
1165                                 break;
1166                         case RPC_MISMATCH:
1167                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1168                                 error = -EPROTONOSUPPORT;
1169                                 goto out_err;
1170                         default:
1171                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1172                                 goto out_eio;
1173                 }
1174                 if (--len < 0)
1175                         goto out_overflow;
1176                 switch ((n = ntohl(*p++))) {
1177                 case RPC_AUTH_REJECTEDCRED:
1178                 case RPC_AUTH_REJECTEDVERF:
1179                 case RPCSEC_GSS_CREDPROBLEM:
1180                 case RPCSEC_GSS_CTXPROBLEM:
1181                         if (!task->tk_cred_retry)
1182                                 break;
1183                         task->tk_cred_retry--;
1184                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1185                                                         task->tk_pid);
1186                         rpcauth_invalcred(task);
1187                         task->tk_action = call_refresh;
1188                         goto out_retry;
1189                 case RPC_AUTH_BADCRED:
1190                 case RPC_AUTH_BADVERF:
1191                         /* possibly garbled cred/verf? */
1192                         if (!task->tk_garb_retry)
1193                                 break;
1194                         task->tk_garb_retry--;
1195                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1196                                                         task->tk_pid);
1197                         task->tk_action = call_bind;
1198                         goto out_retry;
1199                 case RPC_AUTH_TOOWEAK:
1200                         printk(KERN_NOTICE "call_verify: server requires stronger "
1201                                "authentication.\n");
1202                         break;
1203                 default:
1204                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1205                         error = -EIO;
1206                 }
1207                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1208                                                 task->tk_pid, n);
1209                 goto out_err;
1210         }
1211         if (!(p = rpcauth_checkverf(task, p))) {
1212                 printk(KERN_WARNING "call_verify: auth check failed\n");
1213                 goto out_garbage;               /* bad verifier, retry */
1214         }
1215         len = p - (u32 *)iov->iov_base - 1;
1216         if (len < 0)
1217                 goto out_overflow;
1218         switch ((n = ntohl(*p++))) {
1219         case RPC_SUCCESS:
1220                 return p;
1221         case RPC_PROG_UNAVAIL:
1222                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1223                                 (unsigned int)task->tk_client->cl_prog,
1224                                 task->tk_client->cl_server);
1225                 error = -EPFNOSUPPORT;
1226                 goto out_err;
1227         case RPC_PROG_MISMATCH:
1228                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1229                                 (unsigned int)task->tk_client->cl_prog,
1230                                 (unsigned int)task->tk_client->cl_vers,
1231                                 task->tk_client->cl_server);
1232                 error = -EPROTONOSUPPORT;
1233                 goto out_err;
1234         case RPC_PROC_UNAVAIL:
1235                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1236                                 task->tk_msg.rpc_proc,
1237                                 task->tk_client->cl_prog,
1238                                 task->tk_client->cl_vers,
1239                                 task->tk_client->cl_server);
1240                 error = -EOPNOTSUPP;
1241                 goto out_err;
1242         case RPC_GARBAGE_ARGS:
1243                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1244                 break;                  /* retry */
1245         default:
1246                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1247                 /* Also retry */
1248         }
1249
1250 out_garbage:
1251         task->tk_client->cl_stats->rpcgarbage++;
1252         if (task->tk_garb_retry) {
1253                 task->tk_garb_retry--;
1254                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1255                 task->tk_action = call_bind;
1256 out_retry:
1257                 return ERR_PTR(-EAGAIN);
1258         }
1259         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1260 out_eio:
1261         error = -EIO;
1262 out_err:
1263         rpc_exit(task, error);
1264         return ERR_PTR(error);
1265 out_overflow:
1266         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1267         goto out_garbage;
1268 }
1269
1270 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1271 {
1272         return 0;
1273 }
1274
1275 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1276 {
1277         return 0;
1278 }
1279
1280 static struct rpc_procinfo rpcproc_null = {
1281         .p_encode = rpcproc_encode_null,
1282         .p_decode = rpcproc_decode_null,
1283 };
1284
1285 int rpc_ping(struct rpc_clnt *clnt, int flags)
1286 {
1287         struct rpc_message msg = {
1288                 .rpc_proc = &rpcproc_null,
1289         };
1290         int err;
1291         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1292         err = rpc_call_sync(clnt, &msg, flags);
1293         put_rpccred(msg.rpc_cred);
1294         return err;
1295 }