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 #include <linux/workqueue.h> 32 33 #include <linux/sunrpc/clnt.h> 34 #include <linux/sunrpc/rpc_pipe_fs.h> 35 #include <linux/sunrpc/metrics.h> 36 37 38 #define RPC_SLACK_SPACE (1024) /* total overkill */ 39 40 #ifdef RPC_DEBUG 41 # define RPCDBG_FACILITY RPCDBG_CALL 42 #endif 43 44 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); 45 46 47 static void call_start(struct rpc_task *task); 48 static void call_reserve(struct rpc_task *task); 49 static void call_reserveresult(struct rpc_task *task); 50 static void call_allocate(struct rpc_task *task); 51 static void call_encode(struct rpc_task *task); 52 static void call_decode(struct rpc_task *task); 53 static void call_bind(struct rpc_task *task); 54 static void call_bind_status(struct rpc_task *task); 55 static void call_transmit(struct rpc_task *task); 56 static void call_status(struct rpc_task *task); 57 static void call_transmit_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 clnt->cl_vfsmnt = ERR_PTR(-ENOENT); 74 clnt->cl_dentry = ERR_PTR(-ENOENT); 75 if (dir_name == NULL) 76 return 0; 77 78 clnt->cl_vfsmnt = rpc_get_mount(); 79 if (IS_ERR(clnt->cl_vfsmnt)) 80 return PTR_ERR(clnt->cl_vfsmnt); 81 82 for (;;) { 83 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname), 84 "%s/clnt%x", dir_name, 85 (unsigned int)clntid++); 86 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0'; 87 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt); 88 if (!IS_ERR(clnt->cl_dentry)) 89 return 0; 90 error = PTR_ERR(clnt->cl_dentry); 91 if (error != -EEXIST) { 92 printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n", 93 clnt->cl_pathname, error); 94 rpc_put_mount(); 95 return error; 96 } 97 } 98 } 99 100 /* 101 * Create an RPC client 102 * FIXME: This should also take a flags argument (as in task->tk_flags). 103 * It's called (among others) from pmap_create_client, which may in 104 * turn be called by an async task. In this case, rpciod should not be 105 * made to sleep too long. 106 */ 107 struct rpc_clnt * 108 rpc_new_client(struct rpc_xprt *xprt, char *servname, 109 struct rpc_program *program, u32 vers, 110 rpc_authflavor_t flavor) 111 { 112 struct rpc_version *version; 113 struct rpc_clnt *clnt = NULL; 114 struct rpc_auth *auth; 115 int err; 116 int len; 117 118 dprintk("RPC: creating %s client for %s (xprt %p)\n", 119 program->name, servname, xprt); 120 121 err = -EINVAL; 122 if (!xprt) 123 goto out_no_xprt; 124 if (vers >= program->nrvers || !(version = program->version[vers])) 125 goto out_err; 126 127 err = -ENOMEM; 128 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 129 if (!clnt) 130 goto out_err; 131 atomic_set(&clnt->cl_users, 0); 132 atomic_set(&clnt->cl_count, 1); 133 clnt->cl_parent = clnt; 134 135 clnt->cl_server = clnt->cl_inline_name; 136 len = strlen(servname) + 1; 137 if (len > sizeof(clnt->cl_inline_name)) { 138 char *buf = kmalloc(len, GFP_KERNEL); 139 if (buf != 0) 140 clnt->cl_server = buf; 141 else 142 len = sizeof(clnt->cl_inline_name); 143 } 144 strlcpy(clnt->cl_server, servname, len); 145 146 clnt->cl_xprt = xprt; 147 clnt->cl_procinfo = version->procs; 148 clnt->cl_maxproc = version->nrprocs; 149 clnt->cl_protname = program->name; 150 clnt->cl_pmap = &clnt->cl_pmap_default; 151 clnt->cl_port = xprt->addr.sin_port; 152 clnt->cl_prog = program->number; 153 clnt->cl_vers = version->number; 154 clnt->cl_prot = xprt->prot; 155 clnt->cl_stats = program->stats; 156 clnt->cl_metrics = rpc_alloc_iostats(clnt); 157 rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait"); 158 159 if (!clnt->cl_port) 160 clnt->cl_autobind = 1; 161 162 clnt->cl_rtt = &clnt->cl_rtt_default; 163 rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval); 164 165 err = rpc_setup_pipedir(clnt, program->pipe_dir_name); 166 if (err < 0) 167 goto out_no_path; 168 169 auth = rpcauth_create(flavor, clnt); 170 if (IS_ERR(auth)) { 171 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n", 172 flavor); 173 err = PTR_ERR(auth); 174 goto out_no_auth; 175 } 176 177 /* save the nodename */ 178 clnt->cl_nodelen = strlen(system_utsname.nodename); 179 if (clnt->cl_nodelen > UNX_MAXNODENAME) 180 clnt->cl_nodelen = UNX_MAXNODENAME; 181 memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen); 182 return clnt; 183 184 out_no_auth: 185 if (!IS_ERR(clnt->cl_dentry)) { 186 rpc_rmdir(clnt->cl_dentry); 187 rpc_put_mount(); 188 } 189 out_no_path: 190 if (clnt->cl_server != clnt->cl_inline_name) 191 kfree(clnt->cl_server); 192 kfree(clnt); 193 out_err: 194 xprt_destroy(xprt); 195 out_no_xprt: 196 return ERR_PTR(err); 197 } 198 199 /** 200 * Create an RPC client 201 * @xprt - pointer to xprt struct 202 * @servname - name of server 203 * @info - rpc_program 204 * @version - rpc_program version 205 * @authflavor - rpc_auth flavour to use 206 * 207 * Creates an RPC client structure, then pings the server in order to 208 * determine if it is up, and if it supports this program and version. 209 * 210 * This function should never be called by asynchronous tasks such as 211 * the portmapper. 212 */ 213 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname, 214 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor) 215 { 216 struct rpc_clnt *clnt; 217 int err; 218 219 clnt = rpc_new_client(xprt, servname, info, version, authflavor); 220 if (IS_ERR(clnt)) 221 return clnt; 222 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 223 if (err == 0) 224 return clnt; 225 rpc_shutdown_client(clnt); 226 return ERR_PTR(err); 227 } 228 229 /* 230 * This function clones the RPC client structure. It allows us to share the 231 * same transport while varying parameters such as the authentication 232 * flavour. 233 */ 234 struct rpc_clnt * 235 rpc_clone_client(struct rpc_clnt *clnt) 236 { 237 struct rpc_clnt *new; 238 239 new = kmalloc(sizeof(*new), GFP_KERNEL); 240 if (!new) 241 goto out_no_clnt; 242 memcpy(new, clnt, sizeof(*new)); 243 atomic_set(&new->cl_count, 1); 244 atomic_set(&new->cl_users, 0); 245 new->cl_parent = clnt; 246 atomic_inc(&clnt->cl_count); 247 /* Duplicate portmapper */ 248 rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait"); 249 /* Turn off autobind on clones */ 250 new->cl_autobind = 0; 251 new->cl_oneshot = 0; 252 new->cl_dead = 0; 253 if (!IS_ERR(new->cl_dentry)) 254 dget(new->cl_dentry); 255 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval); 256 if (new->cl_auth) 257 atomic_inc(&new->cl_auth->au_count); 258 new->cl_pmap = &new->cl_pmap_default; 259 new->cl_metrics = rpc_alloc_iostats(clnt); 260 return new; 261 out_no_clnt: 262 printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__); 263 return ERR_PTR(-ENOMEM); 264 } 265 266 /* 267 * Properly shut down an RPC client, terminating all outstanding 268 * requests. Note that we must be certain that cl_oneshot and 269 * cl_dead are cleared, or else the client would be destroyed 270 * when the last task releases it. 271 */ 272 int 273 rpc_shutdown_client(struct rpc_clnt *clnt) 274 { 275 dprintk("RPC: shutting down %s client for %s, tasks=%d\n", 276 clnt->cl_protname, clnt->cl_server, 277 atomic_read(&clnt->cl_users)); 278 279 while (atomic_read(&clnt->cl_users) > 0) { 280 /* Don't let rpc_release_client destroy us */ 281 clnt->cl_oneshot = 0; 282 clnt->cl_dead = 0; 283 rpc_killall_tasks(clnt); 284 wait_event_timeout(destroy_wait, 285 !atomic_read(&clnt->cl_users), 1*HZ); 286 } 287 288 if (atomic_read(&clnt->cl_users) < 0) { 289 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n", 290 clnt, atomic_read(&clnt->cl_users)); 291 #ifdef RPC_DEBUG 292 rpc_show_tasks(); 293 #endif 294 BUG(); 295 } 296 297 return rpc_destroy_client(clnt); 298 } 299 300 /* 301 * Delete an RPC client 302 */ 303 int 304 rpc_destroy_client(struct rpc_clnt *clnt) 305 { 306 if (!atomic_dec_and_test(&clnt->cl_count)) 307 return 1; 308 BUG_ON(atomic_read(&clnt->cl_users) != 0); 309 310 dprintk("RPC: destroying %s client for %s\n", 311 clnt->cl_protname, clnt->cl_server); 312 if (clnt->cl_auth) { 313 rpcauth_destroy(clnt->cl_auth); 314 clnt->cl_auth = NULL; 315 } 316 if (clnt->cl_parent != clnt) { 317 if (!IS_ERR(clnt->cl_dentry)) 318 dput(clnt->cl_dentry); 319 rpc_destroy_client(clnt->cl_parent); 320 goto out_free; 321 } 322 if (!IS_ERR(clnt->cl_dentry)) { 323 rpc_rmdir(clnt->cl_dentry); 324 rpc_put_mount(); 325 } 326 if (clnt->cl_xprt) { 327 xprt_destroy(clnt->cl_xprt); 328 clnt->cl_xprt = NULL; 329 } 330 if (clnt->cl_server != clnt->cl_inline_name) 331 kfree(clnt->cl_server); 332 out_free: 333 rpc_free_iostats(clnt->cl_metrics); 334 clnt->cl_metrics = NULL; 335 kfree(clnt); 336 return 0; 337 } 338 339 /* 340 * Release an RPC client 341 */ 342 void 343 rpc_release_client(struct rpc_clnt *clnt) 344 { 345 dprintk("RPC: rpc_release_client(%p, %d)\n", 346 clnt, atomic_read(&clnt->cl_users)); 347 348 if (!atomic_dec_and_test(&clnt->cl_users)) 349 return; 350 wake_up(&destroy_wait); 351 if (clnt->cl_oneshot || clnt->cl_dead) 352 rpc_destroy_client(clnt); 353 } 354 355 /** 356 * rpc_bind_new_program - bind a new RPC program to an existing client 357 * @old - old rpc_client 358 * @program - rpc program to set 359 * @vers - rpc program version 360 * 361 * Clones the rpc client and sets up a new RPC program. This is mainly 362 * of use for enabling different RPC programs to share the same transport. 363 * The Sun NFSv2/v3 ACL protocol can do this. 364 */ 365 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old, 366 struct rpc_program *program, 367 int vers) 368 { 369 struct rpc_clnt *clnt; 370 struct rpc_version *version; 371 int err; 372 373 BUG_ON(vers >= program->nrvers || !program->version[vers]); 374 version = program->version[vers]; 375 clnt = rpc_clone_client(old); 376 if (IS_ERR(clnt)) 377 goto out; 378 clnt->cl_procinfo = version->procs; 379 clnt->cl_maxproc = version->nrprocs; 380 clnt->cl_protname = program->name; 381 clnt->cl_prog = program->number; 382 clnt->cl_vers = version->number; 383 clnt->cl_stats = program->stats; 384 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 385 if (err != 0) { 386 rpc_shutdown_client(clnt); 387 clnt = ERR_PTR(err); 388 } 389 out: 390 return clnt; 391 } 392 393 /* 394 * Default callback for async RPC calls 395 */ 396 static void 397 rpc_default_callback(struct rpc_task *task, void *data) 398 { 399 } 400 401 static const struct rpc_call_ops rpc_default_ops = { 402 .rpc_call_done = rpc_default_callback, 403 }; 404 405 /* 406 * Export the signal mask handling for synchronous code that 407 * sleeps on RPC calls 408 */ 409 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM)) 410 411 static void rpc_save_sigmask(sigset_t *oldset, int intr) 412 { 413 unsigned long sigallow = sigmask(SIGKILL); 414 sigset_t sigmask; 415 416 /* Block all signals except those listed in sigallow */ 417 if (intr) 418 sigallow |= RPC_INTR_SIGNALS; 419 siginitsetinv(&sigmask, sigallow); 420 sigprocmask(SIG_BLOCK, &sigmask, oldset); 421 } 422 423 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset) 424 { 425 rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task)); 426 } 427 428 static inline void rpc_restore_sigmask(sigset_t *oldset) 429 { 430 sigprocmask(SIG_SETMASK, oldset, NULL); 431 } 432 433 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset) 434 { 435 rpc_save_sigmask(oldset, clnt->cl_intr); 436 } 437 438 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset) 439 { 440 rpc_restore_sigmask(oldset); 441 } 442 443 /* 444 * New rpc_call implementation 445 */ 446 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags) 447 { 448 struct rpc_task *task; 449 sigset_t oldset; 450 int status; 451 452 /* If this client is slain all further I/O fails */ 453 if (clnt->cl_dead) 454 return -EIO; 455 456 BUG_ON(flags & RPC_TASK_ASYNC); 457 458 status = -ENOMEM; 459 task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL); 460 if (task == NULL) 461 goto out; 462 463 /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */ 464 rpc_task_sigmask(task, &oldset); 465 466 rpc_call_setup(task, msg, 0); 467 468 /* Set up the call info struct and execute the task */ 469 status = task->tk_status; 470 if (status == 0) { 471 atomic_inc(&task->tk_count); 472 status = rpc_execute(task); 473 if (status == 0) 474 status = task->tk_status; 475 } 476 rpc_restore_sigmask(&oldset); 477 rpc_release_task(task); 478 out: 479 return status; 480 } 481 482 /* 483 * New rpc_call implementation 484 */ 485 int 486 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags, 487 const struct rpc_call_ops *tk_ops, void *data) 488 { 489 struct rpc_task *task; 490 sigset_t oldset; 491 int status; 492 493 /* If this client is slain all further I/O fails */ 494 status = -EIO; 495 if (clnt->cl_dead) 496 goto out_release; 497 498 flags |= RPC_TASK_ASYNC; 499 500 /* Create/initialize a new RPC task */ 501 status = -ENOMEM; 502 if (!(task = rpc_new_task(clnt, flags, tk_ops, data))) 503 goto out_release; 504 505 /* Mask signals on GSS_AUTH upcalls */ 506 rpc_task_sigmask(task, &oldset); 507 508 rpc_call_setup(task, msg, 0); 509 510 /* Set up the call info struct and execute the task */ 511 status = task->tk_status; 512 if (status == 0) 513 rpc_execute(task); 514 else 515 rpc_release_task(task); 516 517 rpc_restore_sigmask(&oldset); 518 return status; 519 out_release: 520 if (tk_ops->rpc_release != NULL) 521 tk_ops->rpc_release(data); 522 return status; 523 } 524 525 526 void 527 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags) 528 { 529 task->tk_msg = *msg; 530 task->tk_flags |= flags; 531 /* Bind the user cred */ 532 if (task->tk_msg.rpc_cred != NULL) 533 rpcauth_holdcred(task); 534 else 535 rpcauth_bindcred(task); 536 537 if (task->tk_status == 0) 538 task->tk_action = call_start; 539 else 540 task->tk_action = rpc_exit_task; 541 } 542 543 void 544 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 545 { 546 struct rpc_xprt *xprt = clnt->cl_xprt; 547 if (xprt->ops->set_buffer_size) 548 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 549 } 550 551 /* 552 * Return size of largest payload RPC client can support, in bytes 553 * 554 * For stream transports, this is one RPC record fragment (see RFC 555 * 1831), as we don't support multi-record requests yet. For datagram 556 * transports, this is the size of an IP packet minus the IP, UDP, and 557 * RPC header sizes. 558 */ 559 size_t rpc_max_payload(struct rpc_clnt *clnt) 560 { 561 return clnt->cl_xprt->max_payload; 562 } 563 EXPORT_SYMBOL(rpc_max_payload); 564 565 /** 566 * rpc_force_rebind - force transport to check that remote port is unchanged 567 * @clnt: client to rebind 568 * 569 */ 570 void rpc_force_rebind(struct rpc_clnt *clnt) 571 { 572 if (clnt->cl_autobind) 573 clnt->cl_port = 0; 574 } 575 EXPORT_SYMBOL(rpc_force_rebind); 576 577 /* 578 * Restart an (async) RPC call. Usually called from within the 579 * exit handler. 580 */ 581 void 582 rpc_restart_call(struct rpc_task *task) 583 { 584 if (RPC_ASSASSINATED(task)) 585 return; 586 587 task->tk_action = call_start; 588 } 589 590 /* 591 * 0. Initial state 592 * 593 * Other FSM states can be visited zero or more times, but 594 * this state is visited exactly once for each RPC. 595 */ 596 static void 597 call_start(struct rpc_task *task) 598 { 599 struct rpc_clnt *clnt = task->tk_client; 600 601 dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid, 602 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc, 603 (RPC_IS_ASYNC(task) ? "async" : "sync")); 604 605 /* Increment call count */ 606 task->tk_msg.rpc_proc->p_count++; 607 clnt->cl_stats->rpccnt++; 608 task->tk_action = call_reserve; 609 } 610 611 /* 612 * 1. Reserve an RPC call slot 613 */ 614 static void 615 call_reserve(struct rpc_task *task) 616 { 617 dprintk("RPC: %4d call_reserve\n", task->tk_pid); 618 619 if (!rpcauth_uptodatecred(task)) { 620 task->tk_action = call_refresh; 621 return; 622 } 623 624 task->tk_status = 0; 625 task->tk_action = call_reserveresult; 626 xprt_reserve(task); 627 } 628 629 /* 630 * 1b. Grok the result of xprt_reserve() 631 */ 632 static void 633 call_reserveresult(struct rpc_task *task) 634 { 635 int status = task->tk_status; 636 637 dprintk("RPC: %4d call_reserveresult (status %d)\n", 638 task->tk_pid, task->tk_status); 639 640 /* 641 * After a call to xprt_reserve(), we must have either 642 * a request slot or else an error status. 643 */ 644 task->tk_status = 0; 645 if (status >= 0) { 646 if (task->tk_rqstp) { 647 task->tk_action = call_allocate; 648 return; 649 } 650 651 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 652 __FUNCTION__, status); 653 rpc_exit(task, -EIO); 654 return; 655 } 656 657 /* 658 * Even though there was an error, we may have acquired 659 * a request slot somehow. Make sure not to leak it. 660 */ 661 if (task->tk_rqstp) { 662 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 663 __FUNCTION__, status); 664 xprt_release(task); 665 } 666 667 switch (status) { 668 case -EAGAIN: /* woken up; retry */ 669 task->tk_action = call_reserve; 670 return; 671 case -EIO: /* probably a shutdown */ 672 break; 673 default: 674 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 675 __FUNCTION__, status); 676 break; 677 } 678 rpc_exit(task, status); 679 } 680 681 /* 682 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. 683 * (Note: buffer memory is freed in xprt_release). 684 */ 685 static void 686 call_allocate(struct rpc_task *task) 687 { 688 struct rpc_rqst *req = task->tk_rqstp; 689 struct rpc_xprt *xprt = task->tk_xprt; 690 unsigned int bufsiz; 691 692 dprintk("RPC: %4d call_allocate (status %d)\n", 693 task->tk_pid, task->tk_status); 694 task->tk_action = call_bind; 695 if (req->rq_buffer) 696 return; 697 698 /* FIXME: compute buffer requirements more exactly using 699 * auth->au_wslack */ 700 bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE; 701 702 if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL) 703 return; 704 printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 705 706 if (RPC_IS_ASYNC(task) || !signalled()) { 707 xprt_release(task); 708 task->tk_action = call_reserve; 709 rpc_delay(task, HZ>>4); 710 return; 711 } 712 713 rpc_exit(task, -ERESTARTSYS); 714 } 715 716 static inline int 717 rpc_task_need_encode(struct rpc_task *task) 718 { 719 return task->tk_rqstp->rq_snd_buf.len == 0; 720 } 721 722 static inline void 723 rpc_task_force_reencode(struct rpc_task *task) 724 { 725 task->tk_rqstp->rq_snd_buf.len = 0; 726 } 727 728 /* 729 * 3. Encode arguments of an RPC call 730 */ 731 static void 732 call_encode(struct rpc_task *task) 733 { 734 struct rpc_rqst *req = task->tk_rqstp; 735 struct xdr_buf *sndbuf = &req->rq_snd_buf; 736 struct xdr_buf *rcvbuf = &req->rq_rcv_buf; 737 unsigned int bufsiz; 738 kxdrproc_t encode; 739 u32 *p; 740 741 dprintk("RPC: %4d call_encode (status %d)\n", 742 task->tk_pid, task->tk_status); 743 744 /* Default buffer setup */ 745 bufsiz = req->rq_bufsize >> 1; 746 sndbuf->head[0].iov_base = (void *)req->rq_buffer; 747 sndbuf->head[0].iov_len = bufsiz; 748 sndbuf->tail[0].iov_len = 0; 749 sndbuf->page_len = 0; 750 sndbuf->len = 0; 751 sndbuf->buflen = bufsiz; 752 rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz); 753 rcvbuf->head[0].iov_len = bufsiz; 754 rcvbuf->tail[0].iov_len = 0; 755 rcvbuf->page_len = 0; 756 rcvbuf->len = 0; 757 rcvbuf->buflen = bufsiz; 758 759 /* Encode header and provided arguments */ 760 encode = task->tk_msg.rpc_proc->p_encode; 761 if (!(p = call_header(task))) { 762 printk(KERN_INFO "RPC: call_header failed, exit EIO\n"); 763 rpc_exit(task, -EIO); 764 return; 765 } 766 if (encode == NULL) 767 return; 768 769 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 770 task->tk_msg.rpc_argp); 771 if (task->tk_status == -ENOMEM) { 772 /* XXX: Is this sane? */ 773 rpc_delay(task, 3*HZ); 774 task->tk_status = -EAGAIN; 775 } 776 } 777 778 /* 779 * 4. Get the server port number if not yet set 780 */ 781 static void 782 call_bind(struct rpc_task *task) 783 { 784 struct rpc_clnt *clnt = task->tk_client; 785 786 dprintk("RPC: %4d call_bind (status %d)\n", 787 task->tk_pid, task->tk_status); 788 789 task->tk_action = call_connect; 790 if (!clnt->cl_port) { 791 task->tk_action = call_bind_status; 792 task->tk_timeout = task->tk_xprt->bind_timeout; 793 rpc_getport(task, clnt); 794 } 795 } 796 797 /* 798 * 4a. Sort out bind result 799 */ 800 static void 801 call_bind_status(struct rpc_task *task) 802 { 803 int status = -EACCES; 804 805 if (task->tk_status >= 0) { 806 dprintk("RPC: %4d call_bind_status (status %d)\n", 807 task->tk_pid, task->tk_status); 808 task->tk_status = 0; 809 task->tk_action = call_connect; 810 return; 811 } 812 813 switch (task->tk_status) { 814 case -EACCES: 815 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n", 816 task->tk_pid); 817 rpc_delay(task, 3*HZ); 818 goto retry_bind; 819 case -ETIMEDOUT: 820 dprintk("RPC: %4d rpcbind request timed out\n", 821 task->tk_pid); 822 if (RPC_IS_SOFT(task)) { 823 status = -EIO; 824 break; 825 } 826 goto retry_bind; 827 case -EPFNOSUPPORT: 828 dprintk("RPC: %4d remote rpcbind service unavailable\n", 829 task->tk_pid); 830 break; 831 case -EPROTONOSUPPORT: 832 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n", 833 task->tk_pid); 834 break; 835 default: 836 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n", 837 task->tk_pid, -task->tk_status); 838 status = -EIO; 839 break; 840 } 841 842 rpc_exit(task, status); 843 return; 844 845 retry_bind: 846 task->tk_status = 0; 847 task->tk_action = call_bind; 848 return; 849 } 850 851 /* 852 * 4b. Connect to the RPC server 853 */ 854 static void 855 call_connect(struct rpc_task *task) 856 { 857 struct rpc_xprt *xprt = task->tk_xprt; 858 859 dprintk("RPC: %4d call_connect xprt %p %s connected\n", 860 task->tk_pid, xprt, 861 (xprt_connected(xprt) ? "is" : "is not")); 862 863 task->tk_action = call_transmit; 864 if (!xprt_connected(xprt)) { 865 task->tk_action = call_connect_status; 866 if (task->tk_status < 0) 867 return; 868 xprt_connect(task); 869 } 870 } 871 872 /* 873 * 4c. Sort out connect result 874 */ 875 static void 876 call_connect_status(struct rpc_task *task) 877 { 878 struct rpc_clnt *clnt = task->tk_client; 879 int status = task->tk_status; 880 881 dprintk("RPC: %5u call_connect_status (status %d)\n", 882 task->tk_pid, task->tk_status); 883 884 task->tk_status = 0; 885 if (status >= 0) { 886 clnt->cl_stats->netreconn++; 887 task->tk_action = call_transmit; 888 return; 889 } 890 891 /* Something failed: remote service port may have changed */ 892 rpc_force_rebind(clnt); 893 894 switch (status) { 895 case -ENOTCONN: 896 case -ETIMEDOUT: 897 case -EAGAIN: 898 task->tk_action = call_bind; 899 break; 900 default: 901 rpc_exit(task, -EIO); 902 break; 903 } 904 } 905 906 /* 907 * 5. Transmit the RPC request, and wait for reply 908 */ 909 static void 910 call_transmit(struct rpc_task *task) 911 { 912 dprintk("RPC: %4d call_transmit (status %d)\n", 913 task->tk_pid, task->tk_status); 914 915 task->tk_action = call_status; 916 if (task->tk_status < 0) 917 return; 918 task->tk_status = xprt_prepare_transmit(task); 919 if (task->tk_status != 0) 920 return; 921 task->tk_action = call_transmit_status; 922 /* Encode here so that rpcsec_gss can use correct sequence number. */ 923 if (rpc_task_need_encode(task)) { 924 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0); 925 call_encode(task); 926 /* Did the encode result in an error condition? */ 927 if (task->tk_status != 0) 928 return; 929 } 930 xprt_transmit(task); 931 if (task->tk_status < 0) 932 return; 933 /* 934 * On success, ensure that we call xprt_end_transmit() before sleeping 935 * in order to allow access to the socket to other RPC requests. 936 */ 937 call_transmit_status(task); 938 if (task->tk_msg.rpc_proc->p_decode != NULL) 939 return; 940 task->tk_action = rpc_exit_task; 941 rpc_wake_up_task(task); 942 } 943 944 /* 945 * 5a. Handle cleanup after a transmission 946 */ 947 static void 948 call_transmit_status(struct rpc_task *task) 949 { 950 task->tk_action = call_status; 951 /* 952 * Special case: if we've been waiting on the socket's write_space() 953 * callback, then don't call xprt_end_transmit(). 954 */ 955 if (task->tk_status == -EAGAIN) 956 return; 957 xprt_end_transmit(task); 958 rpc_task_force_reencode(task); 959 } 960 961 /* 962 * 6. Sort out the RPC call status 963 */ 964 static void 965 call_status(struct rpc_task *task) 966 { 967 struct rpc_clnt *clnt = task->tk_client; 968 struct rpc_rqst *req = task->tk_rqstp; 969 int status; 970 971 if (req->rq_received > 0 && !req->rq_bytes_sent) 972 task->tk_status = req->rq_received; 973 974 dprintk("RPC: %4d call_status (status %d)\n", 975 task->tk_pid, task->tk_status); 976 977 status = task->tk_status; 978 if (status >= 0) { 979 task->tk_action = call_decode; 980 return; 981 } 982 983 task->tk_status = 0; 984 switch(status) { 985 case -ETIMEDOUT: 986 task->tk_action = call_timeout; 987 break; 988 case -ECONNREFUSED: 989 case -ENOTCONN: 990 rpc_force_rebind(clnt); 991 task->tk_action = call_bind; 992 break; 993 case -EAGAIN: 994 task->tk_action = call_transmit; 995 break; 996 case -EIO: 997 /* shutdown or soft timeout */ 998 rpc_exit(task, status); 999 break; 1000 default: 1001 printk("%s: RPC call returned error %d\n", 1002 clnt->cl_protname, -status); 1003 rpc_exit(task, status); 1004 break; 1005 } 1006 } 1007 1008 /* 1009 * 6a. Handle RPC timeout 1010 * We do not release the request slot, so we keep using the 1011 * same XID for all retransmits. 1012 */ 1013 static void 1014 call_timeout(struct rpc_task *task) 1015 { 1016 struct rpc_clnt *clnt = task->tk_client; 1017 1018 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 1019 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid); 1020 goto retry; 1021 } 1022 1023 dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid); 1024 task->tk_timeouts++; 1025 1026 if (RPC_IS_SOFT(task)) { 1027 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 1028 clnt->cl_protname, clnt->cl_server); 1029 rpc_exit(task, -EIO); 1030 return; 1031 } 1032 1033 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 1034 task->tk_flags |= RPC_CALL_MAJORSEEN; 1035 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 1036 clnt->cl_protname, clnt->cl_server); 1037 } 1038 rpc_force_rebind(clnt); 1039 1040 retry: 1041 clnt->cl_stats->rpcretrans++; 1042 task->tk_action = call_bind; 1043 task->tk_status = 0; 1044 } 1045 1046 /* 1047 * 7. Decode the RPC reply 1048 */ 1049 static void 1050 call_decode(struct rpc_task *task) 1051 { 1052 struct rpc_clnt *clnt = task->tk_client; 1053 struct rpc_rqst *req = task->tk_rqstp; 1054 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode; 1055 u32 *p; 1056 1057 dprintk("RPC: %4d call_decode (status %d)\n", 1058 task->tk_pid, task->tk_status); 1059 1060 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 1061 printk(KERN_NOTICE "%s: server %s OK\n", 1062 clnt->cl_protname, clnt->cl_server); 1063 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 1064 } 1065 1066 if (task->tk_status < 12) { 1067 if (!RPC_IS_SOFT(task)) { 1068 task->tk_action = call_bind; 1069 clnt->cl_stats->rpcretrans++; 1070 goto out_retry; 1071 } 1072 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n", 1073 clnt->cl_protname, task->tk_status); 1074 rpc_exit(task, -EIO); 1075 return; 1076 } 1077 1078 /* 1079 * Ensure that we see all writes made by xprt_complete_rqst() 1080 * before it changed req->rq_received. 1081 */ 1082 smp_rmb(); 1083 req->rq_rcv_buf.len = req->rq_private_buf.len; 1084 1085 /* Check that the softirq receive buffer is valid */ 1086 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 1087 sizeof(req->rq_rcv_buf)) != 0); 1088 1089 /* Verify the RPC header */ 1090 p = call_verify(task); 1091 if (IS_ERR(p)) { 1092 if (p == ERR_PTR(-EAGAIN)) 1093 goto out_retry; 1094 return; 1095 } 1096 1097 task->tk_action = rpc_exit_task; 1098 1099 if (decode) 1100 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 1101 task->tk_msg.rpc_resp); 1102 dprintk("RPC: %4d call_decode result %d\n", task->tk_pid, 1103 task->tk_status); 1104 return; 1105 out_retry: 1106 req->rq_received = req->rq_private_buf.len = 0; 1107 task->tk_status = 0; 1108 } 1109 1110 /* 1111 * 8. Refresh the credentials if rejected by the server 1112 */ 1113 static void 1114 call_refresh(struct rpc_task *task) 1115 { 1116 dprintk("RPC: %4d call_refresh\n", task->tk_pid); 1117 1118 xprt_release(task); /* Must do to obtain new XID */ 1119 task->tk_action = call_refreshresult; 1120 task->tk_status = 0; 1121 task->tk_client->cl_stats->rpcauthrefresh++; 1122 rpcauth_refreshcred(task); 1123 } 1124 1125 /* 1126 * 8a. Process the results of a credential refresh 1127 */ 1128 static void 1129 call_refreshresult(struct rpc_task *task) 1130 { 1131 int status = task->tk_status; 1132 dprintk("RPC: %4d call_refreshresult (status %d)\n", 1133 task->tk_pid, task->tk_status); 1134 1135 task->tk_status = 0; 1136 task->tk_action = call_reserve; 1137 if (status >= 0 && rpcauth_uptodatecred(task)) 1138 return; 1139 if (status == -EACCES) { 1140 rpc_exit(task, -EACCES); 1141 return; 1142 } 1143 task->tk_action = call_refresh; 1144 if (status != -ETIMEDOUT) 1145 rpc_delay(task, 3*HZ); 1146 return; 1147 } 1148 1149 /* 1150 * Call header serialization 1151 */ 1152 static u32 * 1153 call_header(struct rpc_task *task) 1154 { 1155 struct rpc_clnt *clnt = task->tk_client; 1156 struct rpc_rqst *req = task->tk_rqstp; 1157 u32 *p = req->rq_svec[0].iov_base; 1158 1159 /* FIXME: check buffer size? */ 1160 1161 p = xprt_skip_transport_header(task->tk_xprt, p); 1162 *p++ = req->rq_xid; /* XID */ 1163 *p++ = htonl(RPC_CALL); /* CALL */ 1164 *p++ = htonl(RPC_VERSION); /* RPC version */ 1165 *p++ = htonl(clnt->cl_prog); /* program number */ 1166 *p++ = htonl(clnt->cl_vers); /* program version */ 1167 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 1168 p = rpcauth_marshcred(task, p); 1169 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 1170 return p; 1171 } 1172 1173 /* 1174 * Reply header verification 1175 */ 1176 static u32 * 1177 call_verify(struct rpc_task *task) 1178 { 1179 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 1180 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 1181 u32 *p = iov->iov_base, n; 1182 int error = -EACCES; 1183 1184 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 1185 /* RFC-1014 says that the representation of XDR data must be a 1186 * multiple of four bytes 1187 * - if it isn't pointer subtraction in the NFS client may give 1188 * undefined results 1189 */ 1190 printk(KERN_WARNING 1191 "call_verify: XDR representation not a multiple of" 1192 " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len); 1193 goto out_eio; 1194 } 1195 if ((len -= 3) < 0) 1196 goto out_overflow; 1197 p += 1; /* skip XID */ 1198 1199 if ((n = ntohl(*p++)) != RPC_REPLY) { 1200 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n); 1201 goto out_garbage; 1202 } 1203 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 1204 if (--len < 0) 1205 goto out_overflow; 1206 switch ((n = ntohl(*p++))) { 1207 case RPC_AUTH_ERROR: 1208 break; 1209 case RPC_MISMATCH: 1210 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__); 1211 error = -EPROTONOSUPPORT; 1212 goto out_err; 1213 default: 1214 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n); 1215 goto out_eio; 1216 } 1217 if (--len < 0) 1218 goto out_overflow; 1219 switch ((n = ntohl(*p++))) { 1220 case RPC_AUTH_REJECTEDCRED: 1221 case RPC_AUTH_REJECTEDVERF: 1222 case RPCSEC_GSS_CREDPROBLEM: 1223 case RPCSEC_GSS_CTXPROBLEM: 1224 if (!task->tk_cred_retry) 1225 break; 1226 task->tk_cred_retry--; 1227 dprintk("RPC: %4d call_verify: retry stale creds\n", 1228 task->tk_pid); 1229 rpcauth_invalcred(task); 1230 task->tk_action = call_refresh; 1231 goto out_retry; 1232 case RPC_AUTH_BADCRED: 1233 case RPC_AUTH_BADVERF: 1234 /* possibly garbled cred/verf? */ 1235 if (!task->tk_garb_retry) 1236 break; 1237 task->tk_garb_retry--; 1238 dprintk("RPC: %4d call_verify: retry garbled creds\n", 1239 task->tk_pid); 1240 task->tk_action = call_bind; 1241 goto out_retry; 1242 case RPC_AUTH_TOOWEAK: 1243 printk(KERN_NOTICE "call_verify: server %s requires stronger " 1244 "authentication.\n", task->tk_client->cl_server); 1245 break; 1246 default: 1247 printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n); 1248 error = -EIO; 1249 } 1250 dprintk("RPC: %4d call_verify: call rejected %d\n", 1251 task->tk_pid, n); 1252 goto out_err; 1253 } 1254 if (!(p = rpcauth_checkverf(task, p))) { 1255 printk(KERN_WARNING "call_verify: auth check failed\n"); 1256 goto out_garbage; /* bad verifier, retry */ 1257 } 1258 len = p - (u32 *)iov->iov_base - 1; 1259 if (len < 0) 1260 goto out_overflow; 1261 switch ((n = ntohl(*p++))) { 1262 case RPC_SUCCESS: 1263 return p; 1264 case RPC_PROG_UNAVAIL: 1265 dprintk("RPC: call_verify: program %u is unsupported by server %s\n", 1266 (unsigned int)task->tk_client->cl_prog, 1267 task->tk_client->cl_server); 1268 error = -EPFNOSUPPORT; 1269 goto out_err; 1270 case RPC_PROG_MISMATCH: 1271 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n", 1272 (unsigned int)task->tk_client->cl_prog, 1273 (unsigned int)task->tk_client->cl_vers, 1274 task->tk_client->cl_server); 1275 error = -EPROTONOSUPPORT; 1276 goto out_err; 1277 case RPC_PROC_UNAVAIL: 1278 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n", 1279 task->tk_msg.rpc_proc, 1280 task->tk_client->cl_prog, 1281 task->tk_client->cl_vers, 1282 task->tk_client->cl_server); 1283 error = -EOPNOTSUPP; 1284 goto out_err; 1285 case RPC_GARBAGE_ARGS: 1286 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__); 1287 break; /* retry */ 1288 default: 1289 printk(KERN_WARNING "call_verify: server accept status: %x\n", n); 1290 /* Also retry */ 1291 } 1292 1293 out_garbage: 1294 task->tk_client->cl_stats->rpcgarbage++; 1295 if (task->tk_garb_retry) { 1296 task->tk_garb_retry--; 1297 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid); 1298 task->tk_action = call_bind; 1299 out_retry: 1300 return ERR_PTR(-EAGAIN); 1301 } 1302 printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__); 1303 out_eio: 1304 error = -EIO; 1305 out_err: 1306 rpc_exit(task, error); 1307 return ERR_PTR(error); 1308 out_overflow: 1309 printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__); 1310 goto out_garbage; 1311 } 1312 1313 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj) 1314 { 1315 return 0; 1316 } 1317 1318 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj) 1319 { 1320 return 0; 1321 } 1322 1323 static struct rpc_procinfo rpcproc_null = { 1324 .p_encode = rpcproc_encode_null, 1325 .p_decode = rpcproc_decode_null, 1326 }; 1327 1328 int rpc_ping(struct rpc_clnt *clnt, int flags) 1329 { 1330 struct rpc_message msg = { 1331 .rpc_proc = &rpcproc_null, 1332 }; 1333 int err; 1334 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 1335 err = rpc_call_sync(clnt, &msg, flags); 1336 put_rpccred(msg.rpc_cred); 1337 return err; 1338 } 1339