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