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