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 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com> 17 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de> 18 */ 19 20 21 #include <linux/module.h> 22 #include <linux/types.h> 23 #include <linux/kallsyms.h> 24 #include <linux/mm.h> 25 #include <linux/namei.h> 26 #include <linux/mount.h> 27 #include <linux/slab.h> 28 #include <linux/rcupdate.h> 29 #include <linux/utsname.h> 30 #include <linux/workqueue.h> 31 #include <linux/in.h> 32 #include <linux/in6.h> 33 #include <linux/un.h> 34 35 #include <linux/sunrpc/clnt.h> 36 #include <linux/sunrpc/addr.h> 37 #include <linux/sunrpc/rpc_pipe_fs.h> 38 #include <linux/sunrpc/metrics.h> 39 #include <linux/sunrpc/bc_xprt.h> 40 #include <trace/events/sunrpc.h> 41 42 #include "sunrpc.h" 43 #include "netns.h" 44 45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 46 # define RPCDBG_FACILITY RPCDBG_CALL 47 #endif 48 49 #define dprint_status(t) \ 50 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \ 51 __func__, t->tk_status) 52 53 /* 54 * All RPC clients are linked into this list 55 */ 56 57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); 58 59 60 static void call_start(struct rpc_task *task); 61 static void call_reserve(struct rpc_task *task); 62 static void call_reserveresult(struct rpc_task *task); 63 static void call_allocate(struct rpc_task *task); 64 static void call_decode(struct rpc_task *task); 65 static void call_bind(struct rpc_task *task); 66 static void call_bind_status(struct rpc_task *task); 67 static void call_transmit(struct rpc_task *task); 68 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 69 static void call_bc_transmit(struct rpc_task *task); 70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 71 static void call_status(struct rpc_task *task); 72 static void call_transmit_status(struct rpc_task *task); 73 static void call_refresh(struct rpc_task *task); 74 static void call_refreshresult(struct rpc_task *task); 75 static void call_timeout(struct rpc_task *task); 76 static void call_connect(struct rpc_task *task); 77 static void call_connect_status(struct rpc_task *task); 78 79 static __be32 *rpc_encode_header(struct rpc_task *task); 80 static __be32 *rpc_verify_header(struct rpc_task *task); 81 static int rpc_ping(struct rpc_clnt *clnt); 82 83 static void rpc_register_client(struct rpc_clnt *clnt) 84 { 85 struct net *net = rpc_net_ns(clnt); 86 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 87 88 spin_lock(&sn->rpc_client_lock); 89 list_add(&clnt->cl_clients, &sn->all_clients); 90 spin_unlock(&sn->rpc_client_lock); 91 } 92 93 static void rpc_unregister_client(struct rpc_clnt *clnt) 94 { 95 struct net *net = rpc_net_ns(clnt); 96 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 97 98 spin_lock(&sn->rpc_client_lock); 99 list_del(&clnt->cl_clients); 100 spin_unlock(&sn->rpc_client_lock); 101 } 102 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt) 104 { 105 rpc_remove_client_dir(clnt); 106 } 107 108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt) 109 { 110 struct net *net = rpc_net_ns(clnt); 111 struct super_block *pipefs_sb; 112 113 pipefs_sb = rpc_get_sb_net(net); 114 if (pipefs_sb) { 115 __rpc_clnt_remove_pipedir(clnt); 116 rpc_put_sb_net(net); 117 } 118 } 119 120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb, 121 struct rpc_clnt *clnt) 122 { 123 static uint32_t clntid; 124 const char *dir_name = clnt->cl_program->pipe_dir_name; 125 char name[15]; 126 struct dentry *dir, *dentry; 127 128 dir = rpc_d_lookup_sb(sb, dir_name); 129 if (dir == NULL) { 130 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name); 131 return dir; 132 } 133 for (;;) { 134 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++); 135 name[sizeof(name) - 1] = '\0'; 136 dentry = rpc_create_client_dir(dir, name, clnt); 137 if (!IS_ERR(dentry)) 138 break; 139 if (dentry == ERR_PTR(-EEXIST)) 140 continue; 141 printk(KERN_INFO "RPC: Couldn't create pipefs entry" 142 " %s/%s, error %ld\n", 143 dir_name, name, PTR_ERR(dentry)); 144 break; 145 } 146 dput(dir); 147 return dentry; 148 } 149 150 static int 151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt) 152 { 153 struct dentry *dentry; 154 155 if (clnt->cl_program->pipe_dir_name != NULL) { 156 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt); 157 if (IS_ERR(dentry)) 158 return PTR_ERR(dentry); 159 } 160 return 0; 161 } 162 163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event) 164 { 165 if (clnt->cl_program->pipe_dir_name == NULL) 166 return 1; 167 168 switch (event) { 169 case RPC_PIPEFS_MOUNT: 170 if (clnt->cl_pipedir_objects.pdh_dentry != NULL) 171 return 1; 172 if (atomic_read(&clnt->cl_count) == 0) 173 return 1; 174 break; 175 case RPC_PIPEFS_UMOUNT: 176 if (clnt->cl_pipedir_objects.pdh_dentry == NULL) 177 return 1; 178 break; 179 } 180 return 0; 181 } 182 183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event, 184 struct super_block *sb) 185 { 186 struct dentry *dentry; 187 int err = 0; 188 189 switch (event) { 190 case RPC_PIPEFS_MOUNT: 191 dentry = rpc_setup_pipedir_sb(sb, clnt); 192 if (!dentry) 193 return -ENOENT; 194 if (IS_ERR(dentry)) 195 return PTR_ERR(dentry); 196 break; 197 case RPC_PIPEFS_UMOUNT: 198 __rpc_clnt_remove_pipedir(clnt); 199 break; 200 default: 201 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event); 202 return -ENOTSUPP; 203 } 204 return err; 205 } 206 207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event, 208 struct super_block *sb) 209 { 210 int error = 0; 211 212 for (;; clnt = clnt->cl_parent) { 213 if (!rpc_clnt_skip_event(clnt, event)) 214 error = __rpc_clnt_handle_event(clnt, event, sb); 215 if (error || clnt == clnt->cl_parent) 216 break; 217 } 218 return error; 219 } 220 221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event) 222 { 223 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 224 struct rpc_clnt *clnt; 225 226 spin_lock(&sn->rpc_client_lock); 227 list_for_each_entry(clnt, &sn->all_clients, cl_clients) { 228 if (rpc_clnt_skip_event(clnt, event)) 229 continue; 230 spin_unlock(&sn->rpc_client_lock); 231 return clnt; 232 } 233 spin_unlock(&sn->rpc_client_lock); 234 return NULL; 235 } 236 237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, 238 void *ptr) 239 { 240 struct super_block *sb = ptr; 241 struct rpc_clnt *clnt; 242 int error = 0; 243 244 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) { 245 error = __rpc_pipefs_event(clnt, event, sb); 246 if (error) 247 break; 248 } 249 return error; 250 } 251 252 static struct notifier_block rpc_clients_block = { 253 .notifier_call = rpc_pipefs_event, 254 .priority = SUNRPC_PIPEFS_RPC_PRIO, 255 }; 256 257 int rpc_clients_notifier_register(void) 258 { 259 return rpc_pipefs_notifier_register(&rpc_clients_block); 260 } 261 262 void rpc_clients_notifier_unregister(void) 263 { 264 return rpc_pipefs_notifier_unregister(&rpc_clients_block); 265 } 266 267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt, 268 struct rpc_xprt *xprt, 269 const struct rpc_timeout *timeout) 270 { 271 struct rpc_xprt *old; 272 273 spin_lock(&clnt->cl_lock); 274 old = rcu_dereference_protected(clnt->cl_xprt, 275 lockdep_is_held(&clnt->cl_lock)); 276 277 if (!xprt_bound(xprt)) 278 clnt->cl_autobind = 1; 279 280 clnt->cl_timeout = timeout; 281 rcu_assign_pointer(clnt->cl_xprt, xprt); 282 spin_unlock(&clnt->cl_lock); 283 284 return old; 285 } 286 287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename) 288 { 289 clnt->cl_nodelen = strlcpy(clnt->cl_nodename, 290 nodename, sizeof(clnt->cl_nodename)); 291 } 292 293 static int rpc_client_register(struct rpc_clnt *clnt, 294 rpc_authflavor_t pseudoflavor, 295 const char *client_name) 296 { 297 struct rpc_auth_create_args auth_args = { 298 .pseudoflavor = pseudoflavor, 299 .target_name = client_name, 300 }; 301 struct rpc_auth *auth; 302 struct net *net = rpc_net_ns(clnt); 303 struct super_block *pipefs_sb; 304 int err; 305 306 rpc_clnt_debugfs_register(clnt); 307 308 pipefs_sb = rpc_get_sb_net(net); 309 if (pipefs_sb) { 310 err = rpc_setup_pipedir(pipefs_sb, clnt); 311 if (err) 312 goto out; 313 } 314 315 rpc_register_client(clnt); 316 if (pipefs_sb) 317 rpc_put_sb_net(net); 318 319 auth = rpcauth_create(&auth_args, clnt); 320 if (IS_ERR(auth)) { 321 dprintk("RPC: Couldn't create auth handle (flavor %u)\n", 322 pseudoflavor); 323 err = PTR_ERR(auth); 324 goto err_auth; 325 } 326 return 0; 327 err_auth: 328 pipefs_sb = rpc_get_sb_net(net); 329 rpc_unregister_client(clnt); 330 __rpc_clnt_remove_pipedir(clnt); 331 out: 332 if (pipefs_sb) 333 rpc_put_sb_net(net); 334 rpc_clnt_debugfs_unregister(clnt); 335 return err; 336 } 337 338 static DEFINE_IDA(rpc_clids); 339 340 static int rpc_alloc_clid(struct rpc_clnt *clnt) 341 { 342 int clid; 343 344 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL); 345 if (clid < 0) 346 return clid; 347 clnt->cl_clid = clid; 348 return 0; 349 } 350 351 static void rpc_free_clid(struct rpc_clnt *clnt) 352 { 353 ida_simple_remove(&rpc_clids, clnt->cl_clid); 354 } 355 356 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, 357 struct rpc_xprt *xprt, 358 struct rpc_clnt *parent) 359 { 360 const struct rpc_program *program = args->program; 361 const struct rpc_version *version; 362 struct rpc_clnt *clnt = NULL; 363 const struct rpc_timeout *timeout; 364 const char *nodename = args->nodename; 365 int err; 366 367 /* sanity check the name before trying to print it */ 368 dprintk("RPC: creating %s client for %s (xprt %p)\n", 369 program->name, args->servername, xprt); 370 371 err = rpciod_up(); 372 if (err) 373 goto out_no_rpciod; 374 375 err = -EINVAL; 376 if (args->version >= program->nrvers) 377 goto out_err; 378 version = program->version[args->version]; 379 if (version == NULL) 380 goto out_err; 381 382 err = -ENOMEM; 383 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 384 if (!clnt) 385 goto out_err; 386 clnt->cl_parent = parent ? : clnt; 387 388 err = rpc_alloc_clid(clnt); 389 if (err) 390 goto out_no_clid; 391 392 clnt->cl_procinfo = version->procs; 393 clnt->cl_maxproc = version->nrprocs; 394 clnt->cl_prog = args->prognumber ? : program->number; 395 clnt->cl_vers = version->number; 396 clnt->cl_stats = program->stats; 397 clnt->cl_metrics = rpc_alloc_iostats(clnt); 398 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects); 399 err = -ENOMEM; 400 if (clnt->cl_metrics == NULL) 401 goto out_no_stats; 402 clnt->cl_program = program; 403 INIT_LIST_HEAD(&clnt->cl_tasks); 404 spin_lock_init(&clnt->cl_lock); 405 406 timeout = xprt->timeout; 407 if (args->timeout != NULL) { 408 memcpy(&clnt->cl_timeout_default, args->timeout, 409 sizeof(clnt->cl_timeout_default)); 410 timeout = &clnt->cl_timeout_default; 411 } 412 413 rpc_clnt_set_transport(clnt, xprt, timeout); 414 415 clnt->cl_rtt = &clnt->cl_rtt_default; 416 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval); 417 418 atomic_set(&clnt->cl_count, 1); 419 420 if (nodename == NULL) 421 nodename = utsname()->nodename; 422 /* save the nodename */ 423 rpc_clnt_set_nodename(clnt, nodename); 424 425 err = rpc_client_register(clnt, args->authflavor, args->client_name); 426 if (err) 427 goto out_no_path; 428 if (parent) 429 atomic_inc(&parent->cl_count); 430 return clnt; 431 432 out_no_path: 433 rpc_free_iostats(clnt->cl_metrics); 434 out_no_stats: 435 rpc_free_clid(clnt); 436 out_no_clid: 437 kfree(clnt); 438 out_err: 439 rpciod_down(); 440 out_no_rpciod: 441 xprt_put(xprt); 442 return ERR_PTR(err); 443 } 444 445 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args, 446 struct rpc_xprt *xprt) 447 { 448 struct rpc_clnt *clnt = NULL; 449 450 clnt = rpc_new_client(args, xprt, NULL); 451 if (IS_ERR(clnt)) 452 return clnt; 453 454 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) { 455 int err = rpc_ping(clnt); 456 if (err != 0) { 457 rpc_shutdown_client(clnt); 458 return ERR_PTR(err); 459 } 460 } 461 462 clnt->cl_softrtry = 1; 463 if (args->flags & RPC_CLNT_CREATE_HARDRTRY) 464 clnt->cl_softrtry = 0; 465 466 if (args->flags & RPC_CLNT_CREATE_AUTOBIND) 467 clnt->cl_autobind = 1; 468 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT) 469 clnt->cl_noretranstimeo = 1; 470 if (args->flags & RPC_CLNT_CREATE_DISCRTRY) 471 clnt->cl_discrtry = 1; 472 if (!(args->flags & RPC_CLNT_CREATE_QUIET)) 473 clnt->cl_chatty = 1; 474 475 return clnt; 476 } 477 EXPORT_SYMBOL_GPL(rpc_create_xprt); 478 479 /** 480 * rpc_create - create an RPC client and transport with one call 481 * @args: rpc_clnt create argument structure 482 * 483 * Creates and initializes an RPC transport and an RPC client. 484 * 485 * It can ping the server in order to determine if it is up, and to see if 486 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables 487 * this behavior so asynchronous tasks can also use rpc_create. 488 */ 489 struct rpc_clnt *rpc_create(struct rpc_create_args *args) 490 { 491 struct rpc_xprt *xprt; 492 struct xprt_create xprtargs = { 493 .net = args->net, 494 .ident = args->protocol, 495 .srcaddr = args->saddress, 496 .dstaddr = args->address, 497 .addrlen = args->addrsize, 498 .servername = args->servername, 499 .bc_xprt = args->bc_xprt, 500 }; 501 char servername[48]; 502 503 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS) 504 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS; 505 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT) 506 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT; 507 /* 508 * If the caller chooses not to specify a hostname, whip 509 * up a string representation of the passed-in address. 510 */ 511 if (xprtargs.servername == NULL) { 512 struct sockaddr_un *sun = 513 (struct sockaddr_un *)args->address; 514 struct sockaddr_in *sin = 515 (struct sockaddr_in *)args->address; 516 struct sockaddr_in6 *sin6 = 517 (struct sockaddr_in6 *)args->address; 518 519 servername[0] = '\0'; 520 switch (args->address->sa_family) { 521 case AF_LOCAL: 522 snprintf(servername, sizeof(servername), "%s", 523 sun->sun_path); 524 break; 525 case AF_INET: 526 snprintf(servername, sizeof(servername), "%pI4", 527 &sin->sin_addr.s_addr); 528 break; 529 case AF_INET6: 530 snprintf(servername, sizeof(servername), "%pI6", 531 &sin6->sin6_addr); 532 break; 533 default: 534 /* caller wants default server name, but 535 * address family isn't recognized. */ 536 return ERR_PTR(-EINVAL); 537 } 538 xprtargs.servername = servername; 539 } 540 541 xprt = xprt_create_transport(&xprtargs); 542 if (IS_ERR(xprt)) 543 return (struct rpc_clnt *)xprt; 544 545 /* 546 * By default, kernel RPC client connects from a reserved port. 547 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters, 548 * but it is always enabled for rpciod, which handles the connect 549 * operation. 550 */ 551 xprt->resvport = 1; 552 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) 553 xprt->resvport = 0; 554 555 return rpc_create_xprt(args, xprt); 556 } 557 EXPORT_SYMBOL_GPL(rpc_create); 558 559 /* 560 * This function clones the RPC client structure. It allows us to share the 561 * same transport while varying parameters such as the authentication 562 * flavour. 563 */ 564 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args, 565 struct rpc_clnt *clnt) 566 { 567 struct rpc_xprt *xprt; 568 struct rpc_clnt *new; 569 int err; 570 571 err = -ENOMEM; 572 rcu_read_lock(); 573 xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); 574 rcu_read_unlock(); 575 if (xprt == NULL) 576 goto out_err; 577 args->servername = xprt->servername; 578 args->nodename = clnt->cl_nodename; 579 580 new = rpc_new_client(args, xprt, clnt); 581 if (IS_ERR(new)) { 582 err = PTR_ERR(new); 583 goto out_err; 584 } 585 586 /* Turn off autobind on clones */ 587 new->cl_autobind = 0; 588 new->cl_softrtry = clnt->cl_softrtry; 589 new->cl_noretranstimeo = clnt->cl_noretranstimeo; 590 new->cl_discrtry = clnt->cl_discrtry; 591 new->cl_chatty = clnt->cl_chatty; 592 return new; 593 594 out_err: 595 dprintk("RPC: %s: returned error %d\n", __func__, err); 596 return ERR_PTR(err); 597 } 598 599 /** 600 * rpc_clone_client - Clone an RPC client structure 601 * 602 * @clnt: RPC client whose parameters are copied 603 * 604 * Returns a fresh RPC client or an ERR_PTR. 605 */ 606 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt) 607 { 608 struct rpc_create_args args = { 609 .program = clnt->cl_program, 610 .prognumber = clnt->cl_prog, 611 .version = clnt->cl_vers, 612 .authflavor = clnt->cl_auth->au_flavor, 613 }; 614 return __rpc_clone_client(&args, clnt); 615 } 616 EXPORT_SYMBOL_GPL(rpc_clone_client); 617 618 /** 619 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth 620 * 621 * @clnt: RPC client whose parameters are copied 622 * @flavor: security flavor for new client 623 * 624 * Returns a fresh RPC client or an ERR_PTR. 625 */ 626 struct rpc_clnt * 627 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 628 { 629 struct rpc_create_args args = { 630 .program = clnt->cl_program, 631 .prognumber = clnt->cl_prog, 632 .version = clnt->cl_vers, 633 .authflavor = flavor, 634 }; 635 return __rpc_clone_client(&args, clnt); 636 } 637 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth); 638 639 /** 640 * rpc_switch_client_transport: switch the RPC transport on the fly 641 * @clnt: pointer to a struct rpc_clnt 642 * @args: pointer to the new transport arguments 643 * @timeout: pointer to the new timeout parameters 644 * 645 * This function allows the caller to switch the RPC transport for the 646 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS 647 * server, for instance. It assumes that the caller has ensured that 648 * there are no active RPC tasks by using some form of locking. 649 * 650 * Returns zero if "clnt" is now using the new xprt. Otherwise a 651 * negative errno is returned, and "clnt" continues to use the old 652 * xprt. 653 */ 654 int rpc_switch_client_transport(struct rpc_clnt *clnt, 655 struct xprt_create *args, 656 const struct rpc_timeout *timeout) 657 { 658 const struct rpc_timeout *old_timeo; 659 rpc_authflavor_t pseudoflavor; 660 struct rpc_xprt *xprt, *old; 661 struct rpc_clnt *parent; 662 int err; 663 664 xprt = xprt_create_transport(args); 665 if (IS_ERR(xprt)) { 666 dprintk("RPC: failed to create new xprt for clnt %p\n", 667 clnt); 668 return PTR_ERR(xprt); 669 } 670 671 pseudoflavor = clnt->cl_auth->au_flavor; 672 673 old_timeo = clnt->cl_timeout; 674 old = rpc_clnt_set_transport(clnt, xprt, timeout); 675 676 rpc_unregister_client(clnt); 677 __rpc_clnt_remove_pipedir(clnt); 678 rpc_clnt_debugfs_unregister(clnt); 679 680 /* 681 * A new transport was created. "clnt" therefore 682 * becomes the root of a new cl_parent tree. clnt's 683 * children, if it has any, still point to the old xprt. 684 */ 685 parent = clnt->cl_parent; 686 clnt->cl_parent = clnt; 687 688 /* 689 * The old rpc_auth cache cannot be re-used. GSS 690 * contexts in particular are between a single 691 * client and server. 692 */ 693 err = rpc_client_register(clnt, pseudoflavor, NULL); 694 if (err) 695 goto out_revert; 696 697 synchronize_rcu(); 698 if (parent != clnt) 699 rpc_release_client(parent); 700 xprt_put(old); 701 dprintk("RPC: replaced xprt for clnt %p\n", clnt); 702 return 0; 703 704 out_revert: 705 rpc_clnt_set_transport(clnt, old, old_timeo); 706 clnt->cl_parent = parent; 707 rpc_client_register(clnt, pseudoflavor, NULL); 708 xprt_put(xprt); 709 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt); 710 return err; 711 } 712 EXPORT_SYMBOL_GPL(rpc_switch_client_transport); 713 714 /* 715 * Kill all tasks for the given client. 716 * XXX: kill their descendants as well? 717 */ 718 void rpc_killall_tasks(struct rpc_clnt *clnt) 719 { 720 struct rpc_task *rovr; 721 722 723 if (list_empty(&clnt->cl_tasks)) 724 return; 725 dprintk("RPC: killing all tasks for client %p\n", clnt); 726 /* 727 * Spin lock all_tasks to prevent changes... 728 */ 729 spin_lock(&clnt->cl_lock); 730 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) { 731 if (!RPC_IS_ACTIVATED(rovr)) 732 continue; 733 if (!(rovr->tk_flags & RPC_TASK_KILLED)) { 734 rovr->tk_flags |= RPC_TASK_KILLED; 735 rpc_exit(rovr, -EIO); 736 if (RPC_IS_QUEUED(rovr)) 737 rpc_wake_up_queued_task(rovr->tk_waitqueue, 738 rovr); 739 } 740 } 741 spin_unlock(&clnt->cl_lock); 742 } 743 EXPORT_SYMBOL_GPL(rpc_killall_tasks); 744 745 /* 746 * Properly shut down an RPC client, terminating all outstanding 747 * requests. 748 */ 749 void rpc_shutdown_client(struct rpc_clnt *clnt) 750 { 751 might_sleep(); 752 753 dprintk_rcu("RPC: shutting down %s client for %s\n", 754 clnt->cl_program->name, 755 rcu_dereference(clnt->cl_xprt)->servername); 756 757 while (!list_empty(&clnt->cl_tasks)) { 758 rpc_killall_tasks(clnt); 759 wait_event_timeout(destroy_wait, 760 list_empty(&clnt->cl_tasks), 1*HZ); 761 } 762 763 rpc_release_client(clnt); 764 } 765 EXPORT_SYMBOL_GPL(rpc_shutdown_client); 766 767 /* 768 * Free an RPC client 769 */ 770 static struct rpc_clnt * 771 rpc_free_client(struct rpc_clnt *clnt) 772 { 773 struct rpc_clnt *parent = NULL; 774 775 dprintk_rcu("RPC: destroying %s client for %s\n", 776 clnt->cl_program->name, 777 rcu_dereference(clnt->cl_xprt)->servername); 778 if (clnt->cl_parent != clnt) 779 parent = clnt->cl_parent; 780 rpc_clnt_debugfs_unregister(clnt); 781 rpc_clnt_remove_pipedir(clnt); 782 rpc_unregister_client(clnt); 783 rpc_free_iostats(clnt->cl_metrics); 784 clnt->cl_metrics = NULL; 785 xprt_put(rcu_dereference_raw(clnt->cl_xprt)); 786 rpciod_down(); 787 rpc_free_clid(clnt); 788 kfree(clnt); 789 return parent; 790 } 791 792 /* 793 * Free an RPC client 794 */ 795 static struct rpc_clnt * 796 rpc_free_auth(struct rpc_clnt *clnt) 797 { 798 if (clnt->cl_auth == NULL) 799 return rpc_free_client(clnt); 800 801 /* 802 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to 803 * release remaining GSS contexts. This mechanism ensures 804 * that it can do so safely. 805 */ 806 atomic_inc(&clnt->cl_count); 807 rpcauth_release(clnt->cl_auth); 808 clnt->cl_auth = NULL; 809 if (atomic_dec_and_test(&clnt->cl_count)) 810 return rpc_free_client(clnt); 811 return NULL; 812 } 813 814 /* 815 * Release reference to the RPC client 816 */ 817 void 818 rpc_release_client(struct rpc_clnt *clnt) 819 { 820 dprintk("RPC: rpc_release_client(%p)\n", clnt); 821 822 do { 823 if (list_empty(&clnt->cl_tasks)) 824 wake_up(&destroy_wait); 825 if (!atomic_dec_and_test(&clnt->cl_count)) 826 break; 827 clnt = rpc_free_auth(clnt); 828 } while (clnt != NULL); 829 } 830 EXPORT_SYMBOL_GPL(rpc_release_client); 831 832 /** 833 * rpc_bind_new_program - bind a new RPC program to an existing client 834 * @old: old rpc_client 835 * @program: rpc program to set 836 * @vers: rpc program version 837 * 838 * Clones the rpc client and sets up a new RPC program. This is mainly 839 * of use for enabling different RPC programs to share the same transport. 840 * The Sun NFSv2/v3 ACL protocol can do this. 841 */ 842 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old, 843 const struct rpc_program *program, 844 u32 vers) 845 { 846 struct rpc_create_args args = { 847 .program = program, 848 .prognumber = program->number, 849 .version = vers, 850 .authflavor = old->cl_auth->au_flavor, 851 }; 852 struct rpc_clnt *clnt; 853 int err; 854 855 clnt = __rpc_clone_client(&args, old); 856 if (IS_ERR(clnt)) 857 goto out; 858 err = rpc_ping(clnt); 859 if (err != 0) { 860 rpc_shutdown_client(clnt); 861 clnt = ERR_PTR(err); 862 } 863 out: 864 return clnt; 865 } 866 EXPORT_SYMBOL_GPL(rpc_bind_new_program); 867 868 void rpc_task_release_client(struct rpc_task *task) 869 { 870 struct rpc_clnt *clnt = task->tk_client; 871 872 if (clnt != NULL) { 873 /* Remove from client task list */ 874 spin_lock(&clnt->cl_lock); 875 list_del(&task->tk_task); 876 spin_unlock(&clnt->cl_lock); 877 task->tk_client = NULL; 878 879 rpc_release_client(clnt); 880 } 881 } 882 883 static 884 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt) 885 { 886 if (clnt != NULL) { 887 rpc_task_release_client(task); 888 task->tk_client = clnt; 889 atomic_inc(&clnt->cl_count); 890 if (clnt->cl_softrtry) 891 task->tk_flags |= RPC_TASK_SOFT; 892 if (clnt->cl_noretranstimeo) 893 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT; 894 if (atomic_read(&clnt->cl_swapper)) 895 task->tk_flags |= RPC_TASK_SWAPPER; 896 /* Add to the client's list of all tasks */ 897 spin_lock(&clnt->cl_lock); 898 list_add_tail(&task->tk_task, &clnt->cl_tasks); 899 spin_unlock(&clnt->cl_lock); 900 } 901 } 902 903 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt) 904 { 905 rpc_task_release_client(task); 906 rpc_task_set_client(task, clnt); 907 } 908 EXPORT_SYMBOL_GPL(rpc_task_reset_client); 909 910 911 static void 912 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg) 913 { 914 if (msg != NULL) { 915 task->tk_msg.rpc_proc = msg->rpc_proc; 916 task->tk_msg.rpc_argp = msg->rpc_argp; 917 task->tk_msg.rpc_resp = msg->rpc_resp; 918 if (msg->rpc_cred != NULL) 919 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred); 920 } 921 } 922 923 /* 924 * Default callback for async RPC calls 925 */ 926 static void 927 rpc_default_callback(struct rpc_task *task, void *data) 928 { 929 } 930 931 static const struct rpc_call_ops rpc_default_ops = { 932 .rpc_call_done = rpc_default_callback, 933 }; 934 935 /** 936 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it 937 * @task_setup_data: pointer to task initialisation data 938 */ 939 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data) 940 { 941 struct rpc_task *task; 942 943 task = rpc_new_task(task_setup_data); 944 if (IS_ERR(task)) 945 goto out; 946 947 rpc_task_set_client(task, task_setup_data->rpc_client); 948 rpc_task_set_rpc_message(task, task_setup_data->rpc_message); 949 950 if (task->tk_action == NULL) 951 rpc_call_start(task); 952 953 atomic_inc(&task->tk_count); 954 rpc_execute(task); 955 out: 956 return task; 957 } 958 EXPORT_SYMBOL_GPL(rpc_run_task); 959 960 /** 961 * rpc_call_sync - Perform a synchronous RPC call 962 * @clnt: pointer to RPC client 963 * @msg: RPC call parameters 964 * @flags: RPC call flags 965 */ 966 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags) 967 { 968 struct rpc_task *task; 969 struct rpc_task_setup task_setup_data = { 970 .rpc_client = clnt, 971 .rpc_message = msg, 972 .callback_ops = &rpc_default_ops, 973 .flags = flags, 974 }; 975 int status; 976 977 WARN_ON_ONCE(flags & RPC_TASK_ASYNC); 978 if (flags & RPC_TASK_ASYNC) { 979 rpc_release_calldata(task_setup_data.callback_ops, 980 task_setup_data.callback_data); 981 return -EINVAL; 982 } 983 984 task = rpc_run_task(&task_setup_data); 985 if (IS_ERR(task)) 986 return PTR_ERR(task); 987 status = task->tk_status; 988 rpc_put_task(task); 989 return status; 990 } 991 EXPORT_SYMBOL_GPL(rpc_call_sync); 992 993 /** 994 * rpc_call_async - Perform an asynchronous RPC call 995 * @clnt: pointer to RPC client 996 * @msg: RPC call parameters 997 * @flags: RPC call flags 998 * @tk_ops: RPC call ops 999 * @data: user call data 1000 */ 1001 int 1002 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags, 1003 const struct rpc_call_ops *tk_ops, void *data) 1004 { 1005 struct rpc_task *task; 1006 struct rpc_task_setup task_setup_data = { 1007 .rpc_client = clnt, 1008 .rpc_message = msg, 1009 .callback_ops = tk_ops, 1010 .callback_data = data, 1011 .flags = flags|RPC_TASK_ASYNC, 1012 }; 1013 1014 task = rpc_run_task(&task_setup_data); 1015 if (IS_ERR(task)) 1016 return PTR_ERR(task); 1017 rpc_put_task(task); 1018 return 0; 1019 } 1020 EXPORT_SYMBOL_GPL(rpc_call_async); 1021 1022 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1023 /** 1024 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run 1025 * rpc_execute against it 1026 * @req: RPC request 1027 */ 1028 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req) 1029 { 1030 struct rpc_task *task; 1031 struct xdr_buf *xbufp = &req->rq_snd_buf; 1032 struct rpc_task_setup task_setup_data = { 1033 .callback_ops = &rpc_default_ops, 1034 .flags = RPC_TASK_SOFTCONN, 1035 }; 1036 1037 dprintk("RPC: rpc_run_bc_task req= %p\n", req); 1038 /* 1039 * Create an rpc_task to send the data 1040 */ 1041 task = rpc_new_task(&task_setup_data); 1042 if (IS_ERR(task)) { 1043 xprt_free_bc_request(req); 1044 goto out; 1045 } 1046 task->tk_rqstp = req; 1047 1048 /* 1049 * Set up the xdr_buf length. 1050 * This also indicates that the buffer is XDR encoded already. 1051 */ 1052 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len + 1053 xbufp->tail[0].iov_len; 1054 1055 task->tk_action = call_bc_transmit; 1056 atomic_inc(&task->tk_count); 1057 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2); 1058 rpc_execute(task); 1059 1060 out: 1061 dprintk("RPC: rpc_run_bc_task: task= %p\n", task); 1062 return task; 1063 } 1064 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 1065 1066 void 1067 rpc_call_start(struct rpc_task *task) 1068 { 1069 task->tk_action = call_start; 1070 } 1071 EXPORT_SYMBOL_GPL(rpc_call_start); 1072 1073 /** 1074 * rpc_peeraddr - extract remote peer address from clnt's xprt 1075 * @clnt: RPC client structure 1076 * @buf: target buffer 1077 * @bufsize: length of target buffer 1078 * 1079 * Returns the number of bytes that are actually in the stored address. 1080 */ 1081 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize) 1082 { 1083 size_t bytes; 1084 struct rpc_xprt *xprt; 1085 1086 rcu_read_lock(); 1087 xprt = rcu_dereference(clnt->cl_xprt); 1088 1089 bytes = xprt->addrlen; 1090 if (bytes > bufsize) 1091 bytes = bufsize; 1092 memcpy(buf, &xprt->addr, bytes); 1093 rcu_read_unlock(); 1094 1095 return bytes; 1096 } 1097 EXPORT_SYMBOL_GPL(rpc_peeraddr); 1098 1099 /** 1100 * rpc_peeraddr2str - return remote peer address in printable format 1101 * @clnt: RPC client structure 1102 * @format: address format 1103 * 1104 * NB: the lifetime of the memory referenced by the returned pointer is 1105 * the same as the rpc_xprt itself. As long as the caller uses this 1106 * pointer, it must hold the RCU read lock. 1107 */ 1108 const char *rpc_peeraddr2str(struct rpc_clnt *clnt, 1109 enum rpc_display_format_t format) 1110 { 1111 struct rpc_xprt *xprt; 1112 1113 xprt = rcu_dereference(clnt->cl_xprt); 1114 1115 if (xprt->address_strings[format] != NULL) 1116 return xprt->address_strings[format]; 1117 else 1118 return "unprintable"; 1119 } 1120 EXPORT_SYMBOL_GPL(rpc_peeraddr2str); 1121 1122 static const struct sockaddr_in rpc_inaddr_loopback = { 1123 .sin_family = AF_INET, 1124 .sin_addr.s_addr = htonl(INADDR_ANY), 1125 }; 1126 1127 static const struct sockaddr_in6 rpc_in6addr_loopback = { 1128 .sin6_family = AF_INET6, 1129 .sin6_addr = IN6ADDR_ANY_INIT, 1130 }; 1131 1132 /* 1133 * Try a getsockname() on a connected datagram socket. Using a 1134 * connected datagram socket prevents leaving a socket in TIME_WAIT. 1135 * This conserves the ephemeral port number space. 1136 * 1137 * Returns zero and fills in "buf" if successful; otherwise, a 1138 * negative errno is returned. 1139 */ 1140 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen, 1141 struct sockaddr *buf, int buflen) 1142 { 1143 struct socket *sock; 1144 int err; 1145 1146 err = __sock_create(net, sap->sa_family, 1147 SOCK_DGRAM, IPPROTO_UDP, &sock, 1); 1148 if (err < 0) { 1149 dprintk("RPC: can't create UDP socket (%d)\n", err); 1150 goto out; 1151 } 1152 1153 switch (sap->sa_family) { 1154 case AF_INET: 1155 err = kernel_bind(sock, 1156 (struct sockaddr *)&rpc_inaddr_loopback, 1157 sizeof(rpc_inaddr_loopback)); 1158 break; 1159 case AF_INET6: 1160 err = kernel_bind(sock, 1161 (struct sockaddr *)&rpc_in6addr_loopback, 1162 sizeof(rpc_in6addr_loopback)); 1163 break; 1164 default: 1165 err = -EAFNOSUPPORT; 1166 goto out; 1167 } 1168 if (err < 0) { 1169 dprintk("RPC: can't bind UDP socket (%d)\n", err); 1170 goto out_release; 1171 } 1172 1173 err = kernel_connect(sock, sap, salen, 0); 1174 if (err < 0) { 1175 dprintk("RPC: can't connect UDP socket (%d)\n", err); 1176 goto out_release; 1177 } 1178 1179 err = kernel_getsockname(sock, buf, &buflen); 1180 if (err < 0) { 1181 dprintk("RPC: getsockname failed (%d)\n", err); 1182 goto out_release; 1183 } 1184 1185 err = 0; 1186 if (buf->sa_family == AF_INET6) { 1187 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf; 1188 sin6->sin6_scope_id = 0; 1189 } 1190 dprintk("RPC: %s succeeded\n", __func__); 1191 1192 out_release: 1193 sock_release(sock); 1194 out: 1195 return err; 1196 } 1197 1198 /* 1199 * Scraping a connected socket failed, so we don't have a useable 1200 * local address. Fallback: generate an address that will prevent 1201 * the server from calling us back. 1202 * 1203 * Returns zero and fills in "buf" if successful; otherwise, a 1204 * negative errno is returned. 1205 */ 1206 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen) 1207 { 1208 switch (family) { 1209 case AF_INET: 1210 if (buflen < sizeof(rpc_inaddr_loopback)) 1211 return -EINVAL; 1212 memcpy(buf, &rpc_inaddr_loopback, 1213 sizeof(rpc_inaddr_loopback)); 1214 break; 1215 case AF_INET6: 1216 if (buflen < sizeof(rpc_in6addr_loopback)) 1217 return -EINVAL; 1218 memcpy(buf, &rpc_in6addr_loopback, 1219 sizeof(rpc_in6addr_loopback)); 1220 default: 1221 dprintk("RPC: %s: address family not supported\n", 1222 __func__); 1223 return -EAFNOSUPPORT; 1224 } 1225 dprintk("RPC: %s: succeeded\n", __func__); 1226 return 0; 1227 } 1228 1229 /** 1230 * rpc_localaddr - discover local endpoint address for an RPC client 1231 * @clnt: RPC client structure 1232 * @buf: target buffer 1233 * @buflen: size of target buffer, in bytes 1234 * 1235 * Returns zero and fills in "buf" and "buflen" if successful; 1236 * otherwise, a negative errno is returned. 1237 * 1238 * This works even if the underlying transport is not currently connected, 1239 * or if the upper layer never previously provided a source address. 1240 * 1241 * The result of this function call is transient: multiple calls in 1242 * succession may give different results, depending on how local 1243 * networking configuration changes over time. 1244 */ 1245 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen) 1246 { 1247 struct sockaddr_storage address; 1248 struct sockaddr *sap = (struct sockaddr *)&address; 1249 struct rpc_xprt *xprt; 1250 struct net *net; 1251 size_t salen; 1252 int err; 1253 1254 rcu_read_lock(); 1255 xprt = rcu_dereference(clnt->cl_xprt); 1256 salen = xprt->addrlen; 1257 memcpy(sap, &xprt->addr, salen); 1258 net = get_net(xprt->xprt_net); 1259 rcu_read_unlock(); 1260 1261 rpc_set_port(sap, 0); 1262 err = rpc_sockname(net, sap, salen, buf, buflen); 1263 put_net(net); 1264 if (err != 0) 1265 /* Couldn't discover local address, return ANYADDR */ 1266 return rpc_anyaddr(sap->sa_family, buf, buflen); 1267 return 0; 1268 } 1269 EXPORT_SYMBOL_GPL(rpc_localaddr); 1270 1271 void 1272 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 1273 { 1274 struct rpc_xprt *xprt; 1275 1276 rcu_read_lock(); 1277 xprt = rcu_dereference(clnt->cl_xprt); 1278 if (xprt->ops->set_buffer_size) 1279 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 1280 rcu_read_unlock(); 1281 } 1282 EXPORT_SYMBOL_GPL(rpc_setbufsize); 1283 1284 /** 1285 * rpc_protocol - Get transport protocol number for an RPC client 1286 * @clnt: RPC client to query 1287 * 1288 */ 1289 int rpc_protocol(struct rpc_clnt *clnt) 1290 { 1291 int protocol; 1292 1293 rcu_read_lock(); 1294 protocol = rcu_dereference(clnt->cl_xprt)->prot; 1295 rcu_read_unlock(); 1296 return protocol; 1297 } 1298 EXPORT_SYMBOL_GPL(rpc_protocol); 1299 1300 /** 1301 * rpc_net_ns - Get the network namespace for this RPC client 1302 * @clnt: RPC client to query 1303 * 1304 */ 1305 struct net *rpc_net_ns(struct rpc_clnt *clnt) 1306 { 1307 struct net *ret; 1308 1309 rcu_read_lock(); 1310 ret = rcu_dereference(clnt->cl_xprt)->xprt_net; 1311 rcu_read_unlock(); 1312 return ret; 1313 } 1314 EXPORT_SYMBOL_GPL(rpc_net_ns); 1315 1316 /** 1317 * rpc_max_payload - Get maximum payload size for a transport, in bytes 1318 * @clnt: RPC client to query 1319 * 1320 * For stream transports, this is one RPC record fragment (see RFC 1321 * 1831), as we don't support multi-record requests yet. For datagram 1322 * transports, this is the size of an IP packet minus the IP, UDP, and 1323 * RPC header sizes. 1324 */ 1325 size_t rpc_max_payload(struct rpc_clnt *clnt) 1326 { 1327 size_t ret; 1328 1329 rcu_read_lock(); 1330 ret = rcu_dereference(clnt->cl_xprt)->max_payload; 1331 rcu_read_unlock(); 1332 return ret; 1333 } 1334 EXPORT_SYMBOL_GPL(rpc_max_payload); 1335 1336 /** 1337 * rpc_get_timeout - Get timeout for transport in units of HZ 1338 * @clnt: RPC client to query 1339 */ 1340 unsigned long rpc_get_timeout(struct rpc_clnt *clnt) 1341 { 1342 unsigned long ret; 1343 1344 rcu_read_lock(); 1345 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval; 1346 rcu_read_unlock(); 1347 return ret; 1348 } 1349 EXPORT_SYMBOL_GPL(rpc_get_timeout); 1350 1351 /** 1352 * rpc_force_rebind - force transport to check that remote port is unchanged 1353 * @clnt: client to rebind 1354 * 1355 */ 1356 void rpc_force_rebind(struct rpc_clnt *clnt) 1357 { 1358 if (clnt->cl_autobind) { 1359 rcu_read_lock(); 1360 xprt_clear_bound(rcu_dereference(clnt->cl_xprt)); 1361 rcu_read_unlock(); 1362 } 1363 } 1364 EXPORT_SYMBOL_GPL(rpc_force_rebind); 1365 1366 /* 1367 * Restart an (async) RPC call from the call_prepare state. 1368 * Usually called from within the exit handler. 1369 */ 1370 int 1371 rpc_restart_call_prepare(struct rpc_task *task) 1372 { 1373 if (RPC_ASSASSINATED(task)) 1374 return 0; 1375 task->tk_action = call_start; 1376 task->tk_status = 0; 1377 if (task->tk_ops->rpc_call_prepare != NULL) 1378 task->tk_action = rpc_prepare_task; 1379 return 1; 1380 } 1381 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare); 1382 1383 /* 1384 * Restart an (async) RPC call. Usually called from within the 1385 * exit handler. 1386 */ 1387 int 1388 rpc_restart_call(struct rpc_task *task) 1389 { 1390 if (RPC_ASSASSINATED(task)) 1391 return 0; 1392 task->tk_action = call_start; 1393 task->tk_status = 0; 1394 return 1; 1395 } 1396 EXPORT_SYMBOL_GPL(rpc_restart_call); 1397 1398 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 1399 const char 1400 *rpc_proc_name(const struct rpc_task *task) 1401 { 1402 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc; 1403 1404 if (proc) { 1405 if (proc->p_name) 1406 return proc->p_name; 1407 else 1408 return "NULL"; 1409 } else 1410 return "no proc"; 1411 } 1412 #endif 1413 1414 /* 1415 * 0. Initial state 1416 * 1417 * Other FSM states can be visited zero or more times, but 1418 * this state is visited exactly once for each RPC. 1419 */ 1420 static void 1421 call_start(struct rpc_task *task) 1422 { 1423 struct rpc_clnt *clnt = task->tk_client; 1424 1425 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid, 1426 clnt->cl_program->name, clnt->cl_vers, 1427 rpc_proc_name(task), 1428 (RPC_IS_ASYNC(task) ? "async" : "sync")); 1429 1430 /* Increment call count */ 1431 task->tk_msg.rpc_proc->p_count++; 1432 clnt->cl_stats->rpccnt++; 1433 task->tk_action = call_reserve; 1434 } 1435 1436 /* 1437 * 1. Reserve an RPC call slot 1438 */ 1439 static void 1440 call_reserve(struct rpc_task *task) 1441 { 1442 dprint_status(task); 1443 1444 task->tk_status = 0; 1445 task->tk_action = call_reserveresult; 1446 xprt_reserve(task); 1447 } 1448 1449 static void call_retry_reserve(struct rpc_task *task); 1450 1451 /* 1452 * 1b. Grok the result of xprt_reserve() 1453 */ 1454 static void 1455 call_reserveresult(struct rpc_task *task) 1456 { 1457 int status = task->tk_status; 1458 1459 dprint_status(task); 1460 1461 /* 1462 * After a call to xprt_reserve(), we must have either 1463 * a request slot or else an error status. 1464 */ 1465 task->tk_status = 0; 1466 if (status >= 0) { 1467 if (task->tk_rqstp) { 1468 task->tk_action = call_refresh; 1469 return; 1470 } 1471 1472 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 1473 __func__, status); 1474 rpc_exit(task, -EIO); 1475 return; 1476 } 1477 1478 /* 1479 * Even though there was an error, we may have acquired 1480 * a request slot somehow. Make sure not to leak it. 1481 */ 1482 if (task->tk_rqstp) { 1483 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 1484 __func__, status); 1485 xprt_release(task); 1486 } 1487 1488 switch (status) { 1489 case -ENOMEM: 1490 rpc_delay(task, HZ >> 2); 1491 case -EAGAIN: /* woken up; retry */ 1492 task->tk_action = call_retry_reserve; 1493 return; 1494 case -EIO: /* probably a shutdown */ 1495 break; 1496 default: 1497 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 1498 __func__, status); 1499 break; 1500 } 1501 rpc_exit(task, status); 1502 } 1503 1504 /* 1505 * 1c. Retry reserving an RPC call slot 1506 */ 1507 static void 1508 call_retry_reserve(struct rpc_task *task) 1509 { 1510 dprint_status(task); 1511 1512 task->tk_status = 0; 1513 task->tk_action = call_reserveresult; 1514 xprt_retry_reserve(task); 1515 } 1516 1517 /* 1518 * 2. Bind and/or refresh the credentials 1519 */ 1520 static void 1521 call_refresh(struct rpc_task *task) 1522 { 1523 dprint_status(task); 1524 1525 task->tk_action = call_refreshresult; 1526 task->tk_status = 0; 1527 task->tk_client->cl_stats->rpcauthrefresh++; 1528 rpcauth_refreshcred(task); 1529 } 1530 1531 /* 1532 * 2a. Process the results of a credential refresh 1533 */ 1534 static void 1535 call_refreshresult(struct rpc_task *task) 1536 { 1537 int status = task->tk_status; 1538 1539 dprint_status(task); 1540 1541 task->tk_status = 0; 1542 task->tk_action = call_refresh; 1543 switch (status) { 1544 case 0: 1545 if (rpcauth_uptodatecred(task)) { 1546 task->tk_action = call_allocate; 1547 return; 1548 } 1549 /* Use rate-limiting and a max number of retries if refresh 1550 * had status 0 but failed to update the cred. 1551 */ 1552 case -ETIMEDOUT: 1553 rpc_delay(task, 3*HZ); 1554 case -EAGAIN: 1555 status = -EACCES; 1556 case -EKEYEXPIRED: 1557 if (!task->tk_cred_retry) 1558 break; 1559 task->tk_cred_retry--; 1560 dprintk("RPC: %5u %s: retry refresh creds\n", 1561 task->tk_pid, __func__); 1562 return; 1563 } 1564 dprintk("RPC: %5u %s: refresh creds failed with error %d\n", 1565 task->tk_pid, __func__, status); 1566 rpc_exit(task, status); 1567 } 1568 1569 /* 1570 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc. 1571 * (Note: buffer memory is freed in xprt_release). 1572 */ 1573 static void 1574 call_allocate(struct rpc_task *task) 1575 { 1576 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack; 1577 struct rpc_rqst *req = task->tk_rqstp; 1578 struct rpc_xprt *xprt = req->rq_xprt; 1579 struct rpc_procinfo *proc = task->tk_msg.rpc_proc; 1580 1581 dprint_status(task); 1582 1583 task->tk_status = 0; 1584 task->tk_action = call_bind; 1585 1586 if (req->rq_buffer) 1587 return; 1588 1589 if (proc->p_proc != 0) { 1590 BUG_ON(proc->p_arglen == 0); 1591 if (proc->p_decode != NULL) 1592 BUG_ON(proc->p_replen == 0); 1593 } 1594 1595 /* 1596 * Calculate the size (in quads) of the RPC call 1597 * and reply headers, and convert both values 1598 * to byte sizes. 1599 */ 1600 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen; 1601 req->rq_callsize <<= 2; 1602 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen; 1603 req->rq_rcvsize <<= 2; 1604 1605 req->rq_buffer = xprt->ops->buf_alloc(task, 1606 req->rq_callsize + req->rq_rcvsize); 1607 if (req->rq_buffer != NULL) 1608 return; 1609 xprt_inject_disconnect(xprt); 1610 1611 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid); 1612 1613 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) { 1614 task->tk_action = call_allocate; 1615 rpc_delay(task, HZ>>4); 1616 return; 1617 } 1618 1619 rpc_exit(task, -ERESTARTSYS); 1620 } 1621 1622 static inline int 1623 rpc_task_need_encode(struct rpc_task *task) 1624 { 1625 return task->tk_rqstp->rq_snd_buf.len == 0; 1626 } 1627 1628 static inline void 1629 rpc_task_force_reencode(struct rpc_task *task) 1630 { 1631 task->tk_rqstp->rq_snd_buf.len = 0; 1632 task->tk_rqstp->rq_bytes_sent = 0; 1633 } 1634 1635 static inline void 1636 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len) 1637 { 1638 buf->head[0].iov_base = start; 1639 buf->head[0].iov_len = len; 1640 buf->tail[0].iov_len = 0; 1641 buf->page_len = 0; 1642 buf->flags = 0; 1643 buf->len = 0; 1644 buf->buflen = len; 1645 } 1646 1647 /* 1648 * 3. Encode arguments of an RPC call 1649 */ 1650 static void 1651 rpc_xdr_encode(struct rpc_task *task) 1652 { 1653 struct rpc_rqst *req = task->tk_rqstp; 1654 kxdreproc_t encode; 1655 __be32 *p; 1656 1657 dprint_status(task); 1658 1659 rpc_xdr_buf_init(&req->rq_snd_buf, 1660 req->rq_buffer, 1661 req->rq_callsize); 1662 rpc_xdr_buf_init(&req->rq_rcv_buf, 1663 (char *)req->rq_buffer + req->rq_callsize, 1664 req->rq_rcvsize); 1665 1666 p = rpc_encode_header(task); 1667 if (p == NULL) { 1668 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n"); 1669 rpc_exit(task, -EIO); 1670 return; 1671 } 1672 1673 encode = task->tk_msg.rpc_proc->p_encode; 1674 if (encode == NULL) 1675 return; 1676 1677 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 1678 task->tk_msg.rpc_argp); 1679 } 1680 1681 /* 1682 * 4. Get the server port number if not yet set 1683 */ 1684 static void 1685 call_bind(struct rpc_task *task) 1686 { 1687 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 1688 1689 dprint_status(task); 1690 1691 task->tk_action = call_connect; 1692 if (!xprt_bound(xprt)) { 1693 task->tk_action = call_bind_status; 1694 task->tk_timeout = xprt->bind_timeout; 1695 xprt->ops->rpcbind(task); 1696 } 1697 } 1698 1699 /* 1700 * 4a. Sort out bind result 1701 */ 1702 static void 1703 call_bind_status(struct rpc_task *task) 1704 { 1705 int status = -EIO; 1706 1707 if (task->tk_status >= 0) { 1708 dprint_status(task); 1709 task->tk_status = 0; 1710 task->tk_action = call_connect; 1711 return; 1712 } 1713 1714 trace_rpc_bind_status(task); 1715 switch (task->tk_status) { 1716 case -ENOMEM: 1717 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid); 1718 rpc_delay(task, HZ >> 2); 1719 goto retry_timeout; 1720 case -EACCES: 1721 dprintk("RPC: %5u remote rpcbind: RPC program/version " 1722 "unavailable\n", task->tk_pid); 1723 /* fail immediately if this is an RPC ping */ 1724 if (task->tk_msg.rpc_proc->p_proc == 0) { 1725 status = -EOPNOTSUPP; 1726 break; 1727 } 1728 if (task->tk_rebind_retry == 0) 1729 break; 1730 task->tk_rebind_retry--; 1731 rpc_delay(task, 3*HZ); 1732 goto retry_timeout; 1733 case -ETIMEDOUT: 1734 dprintk("RPC: %5u rpcbind request timed out\n", 1735 task->tk_pid); 1736 goto retry_timeout; 1737 case -EPFNOSUPPORT: 1738 /* server doesn't support any rpcbind version we know of */ 1739 dprintk("RPC: %5u unrecognized remote rpcbind service\n", 1740 task->tk_pid); 1741 break; 1742 case -EPROTONOSUPPORT: 1743 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n", 1744 task->tk_pid); 1745 goto retry_timeout; 1746 case -ECONNREFUSED: /* connection problems */ 1747 case -ECONNRESET: 1748 case -ECONNABORTED: 1749 case -ENOTCONN: 1750 case -EHOSTDOWN: 1751 case -EHOSTUNREACH: 1752 case -ENETUNREACH: 1753 case -ENOBUFS: 1754 case -EPIPE: 1755 dprintk("RPC: %5u remote rpcbind unreachable: %d\n", 1756 task->tk_pid, task->tk_status); 1757 if (!RPC_IS_SOFTCONN(task)) { 1758 rpc_delay(task, 5*HZ); 1759 goto retry_timeout; 1760 } 1761 status = task->tk_status; 1762 break; 1763 default: 1764 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n", 1765 task->tk_pid, -task->tk_status); 1766 } 1767 1768 rpc_exit(task, status); 1769 return; 1770 1771 retry_timeout: 1772 task->tk_status = 0; 1773 task->tk_action = call_timeout; 1774 } 1775 1776 /* 1777 * 4b. Connect to the RPC server 1778 */ 1779 static void 1780 call_connect(struct rpc_task *task) 1781 { 1782 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 1783 1784 dprintk("RPC: %5u call_connect xprt %p %s connected\n", 1785 task->tk_pid, xprt, 1786 (xprt_connected(xprt) ? "is" : "is not")); 1787 1788 task->tk_action = call_transmit; 1789 if (!xprt_connected(xprt)) { 1790 task->tk_action = call_connect_status; 1791 if (task->tk_status < 0) 1792 return; 1793 if (task->tk_flags & RPC_TASK_NOCONNECT) { 1794 rpc_exit(task, -ENOTCONN); 1795 return; 1796 } 1797 xprt_connect(task); 1798 } 1799 } 1800 1801 /* 1802 * 4c. Sort out connect result 1803 */ 1804 static void 1805 call_connect_status(struct rpc_task *task) 1806 { 1807 struct rpc_clnt *clnt = task->tk_client; 1808 int status = task->tk_status; 1809 1810 dprint_status(task); 1811 1812 trace_rpc_connect_status(task, status); 1813 task->tk_status = 0; 1814 switch (status) { 1815 case -ECONNREFUSED: 1816 case -ECONNRESET: 1817 case -ECONNABORTED: 1818 case -ENETUNREACH: 1819 case -EHOSTUNREACH: 1820 case -EADDRINUSE: 1821 case -ENOBUFS: 1822 case -EPIPE: 1823 if (RPC_IS_SOFTCONN(task)) 1824 break; 1825 /* retry with existing socket, after a delay */ 1826 rpc_delay(task, 3*HZ); 1827 case -EAGAIN: 1828 /* Check for timeouts before looping back to call_bind */ 1829 case -ETIMEDOUT: 1830 task->tk_action = call_timeout; 1831 return; 1832 case 0: 1833 clnt->cl_stats->netreconn++; 1834 task->tk_action = call_transmit; 1835 return; 1836 } 1837 rpc_exit(task, status); 1838 } 1839 1840 /* 1841 * 5. Transmit the RPC request, and wait for reply 1842 */ 1843 static void 1844 call_transmit(struct rpc_task *task) 1845 { 1846 int is_retrans = RPC_WAS_SENT(task); 1847 1848 dprint_status(task); 1849 1850 task->tk_action = call_status; 1851 if (task->tk_status < 0) 1852 return; 1853 if (!xprt_prepare_transmit(task)) 1854 return; 1855 task->tk_action = call_transmit_status; 1856 /* Encode here so that rpcsec_gss can use correct sequence number. */ 1857 if (rpc_task_need_encode(task)) { 1858 rpc_xdr_encode(task); 1859 /* Did the encode result in an error condition? */ 1860 if (task->tk_status != 0) { 1861 /* Was the error nonfatal? */ 1862 if (task->tk_status == -EAGAIN) 1863 rpc_delay(task, HZ >> 4); 1864 else 1865 rpc_exit(task, task->tk_status); 1866 return; 1867 } 1868 } 1869 xprt_transmit(task); 1870 if (task->tk_status < 0) 1871 return; 1872 if (is_retrans) 1873 task->tk_client->cl_stats->rpcretrans++; 1874 /* 1875 * On success, ensure that we call xprt_end_transmit() before sleeping 1876 * in order to allow access to the socket to other RPC requests. 1877 */ 1878 call_transmit_status(task); 1879 if (rpc_reply_expected(task)) 1880 return; 1881 task->tk_action = rpc_exit_task; 1882 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task); 1883 } 1884 1885 /* 1886 * 5a. Handle cleanup after a transmission 1887 */ 1888 static void 1889 call_transmit_status(struct rpc_task *task) 1890 { 1891 task->tk_action = call_status; 1892 1893 /* 1894 * Common case: success. Force the compiler to put this 1895 * test first. 1896 */ 1897 if (task->tk_status == 0) { 1898 xprt_end_transmit(task); 1899 rpc_task_force_reencode(task); 1900 return; 1901 } 1902 1903 switch (task->tk_status) { 1904 case -EAGAIN: 1905 case -ENOBUFS: 1906 break; 1907 default: 1908 dprint_status(task); 1909 xprt_end_transmit(task); 1910 rpc_task_force_reencode(task); 1911 break; 1912 /* 1913 * Special cases: if we've been waiting on the 1914 * socket's write_space() callback, or if the 1915 * socket just returned a connection error, 1916 * then hold onto the transport lock. 1917 */ 1918 case -ECONNREFUSED: 1919 case -EHOSTDOWN: 1920 case -EHOSTUNREACH: 1921 case -ENETUNREACH: 1922 case -EPERM: 1923 if (RPC_IS_SOFTCONN(task)) { 1924 xprt_end_transmit(task); 1925 rpc_exit(task, task->tk_status); 1926 break; 1927 } 1928 case -ECONNRESET: 1929 case -ECONNABORTED: 1930 case -EADDRINUSE: 1931 case -ENOTCONN: 1932 case -EPIPE: 1933 rpc_task_force_reencode(task); 1934 } 1935 } 1936 1937 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1938 /* 1939 * 5b. Send the backchannel RPC reply. On error, drop the reply. In 1940 * addition, disconnect on connectivity errors. 1941 */ 1942 static void 1943 call_bc_transmit(struct rpc_task *task) 1944 { 1945 struct rpc_rqst *req = task->tk_rqstp; 1946 1947 if (!xprt_prepare_transmit(task)) 1948 goto out_retry; 1949 1950 if (task->tk_status < 0) { 1951 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1952 "error: %d\n", task->tk_status); 1953 goto out_done; 1954 } 1955 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie) 1956 req->rq_bytes_sent = 0; 1957 1958 xprt_transmit(task); 1959 1960 if (task->tk_status == -EAGAIN) 1961 goto out_nospace; 1962 1963 xprt_end_transmit(task); 1964 dprint_status(task); 1965 switch (task->tk_status) { 1966 case 0: 1967 /* Success */ 1968 case -EHOSTDOWN: 1969 case -EHOSTUNREACH: 1970 case -ENETUNREACH: 1971 case -ECONNRESET: 1972 case -ECONNREFUSED: 1973 case -EADDRINUSE: 1974 case -ENOTCONN: 1975 case -EPIPE: 1976 break; 1977 case -ETIMEDOUT: 1978 /* 1979 * Problem reaching the server. Disconnect and let the 1980 * forechannel reestablish the connection. The server will 1981 * have to retransmit the backchannel request and we'll 1982 * reprocess it. Since these ops are idempotent, there's no 1983 * need to cache our reply at this time. 1984 */ 1985 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1986 "error: %d\n", task->tk_status); 1987 xprt_conditional_disconnect(req->rq_xprt, 1988 req->rq_connect_cookie); 1989 break; 1990 default: 1991 /* 1992 * We were unable to reply and will have to drop the 1993 * request. The server should reconnect and retransmit. 1994 */ 1995 WARN_ON_ONCE(task->tk_status == -EAGAIN); 1996 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1997 "error: %d\n", task->tk_status); 1998 break; 1999 } 2000 rpc_wake_up_queued_task(&req->rq_xprt->pending, task); 2001 out_done: 2002 task->tk_action = rpc_exit_task; 2003 return; 2004 out_nospace: 2005 req->rq_connect_cookie = req->rq_xprt->connect_cookie; 2006 out_retry: 2007 task->tk_status = 0; 2008 } 2009 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 2010 2011 /* 2012 * 6. Sort out the RPC call status 2013 */ 2014 static void 2015 call_status(struct rpc_task *task) 2016 { 2017 struct rpc_clnt *clnt = task->tk_client; 2018 struct rpc_rqst *req = task->tk_rqstp; 2019 int status; 2020 2021 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent) 2022 task->tk_status = req->rq_reply_bytes_recvd; 2023 2024 dprint_status(task); 2025 2026 status = task->tk_status; 2027 if (status >= 0) { 2028 task->tk_action = call_decode; 2029 return; 2030 } 2031 2032 trace_rpc_call_status(task); 2033 task->tk_status = 0; 2034 switch(status) { 2035 case -EHOSTDOWN: 2036 case -EHOSTUNREACH: 2037 case -ENETUNREACH: 2038 case -EPERM: 2039 if (RPC_IS_SOFTCONN(task)) { 2040 rpc_exit(task, status); 2041 break; 2042 } 2043 /* 2044 * Delay any retries for 3 seconds, then handle as if it 2045 * were a timeout. 2046 */ 2047 rpc_delay(task, 3*HZ); 2048 case -ETIMEDOUT: 2049 task->tk_action = call_timeout; 2050 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) 2051 && task->tk_client->cl_discrtry) 2052 xprt_conditional_disconnect(req->rq_xprt, 2053 req->rq_connect_cookie); 2054 break; 2055 case -ECONNREFUSED: 2056 case -ECONNRESET: 2057 case -ECONNABORTED: 2058 rpc_force_rebind(clnt); 2059 case -EADDRINUSE: 2060 rpc_delay(task, 3*HZ); 2061 case -EPIPE: 2062 case -ENOTCONN: 2063 task->tk_action = call_bind; 2064 break; 2065 case -ENOBUFS: 2066 rpc_delay(task, HZ>>2); 2067 case -EAGAIN: 2068 task->tk_action = call_transmit; 2069 break; 2070 case -EIO: 2071 /* shutdown or soft timeout */ 2072 rpc_exit(task, status); 2073 break; 2074 default: 2075 if (clnt->cl_chatty) 2076 printk("%s: RPC call returned error %d\n", 2077 clnt->cl_program->name, -status); 2078 rpc_exit(task, status); 2079 } 2080 } 2081 2082 /* 2083 * 6a. Handle RPC timeout 2084 * We do not release the request slot, so we keep using the 2085 * same XID for all retransmits. 2086 */ 2087 static void 2088 call_timeout(struct rpc_task *task) 2089 { 2090 struct rpc_clnt *clnt = task->tk_client; 2091 2092 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 2093 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid); 2094 goto retry; 2095 } 2096 2097 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid); 2098 task->tk_timeouts++; 2099 2100 if (RPC_IS_SOFTCONN(task)) { 2101 rpc_exit(task, -ETIMEDOUT); 2102 return; 2103 } 2104 if (RPC_IS_SOFT(task)) { 2105 if (clnt->cl_chatty) { 2106 rcu_read_lock(); 2107 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 2108 clnt->cl_program->name, 2109 rcu_dereference(clnt->cl_xprt)->servername); 2110 rcu_read_unlock(); 2111 } 2112 if (task->tk_flags & RPC_TASK_TIMEOUT) 2113 rpc_exit(task, -ETIMEDOUT); 2114 else 2115 rpc_exit(task, -EIO); 2116 return; 2117 } 2118 2119 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 2120 task->tk_flags |= RPC_CALL_MAJORSEEN; 2121 if (clnt->cl_chatty) { 2122 rcu_read_lock(); 2123 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 2124 clnt->cl_program->name, 2125 rcu_dereference(clnt->cl_xprt)->servername); 2126 rcu_read_unlock(); 2127 } 2128 } 2129 rpc_force_rebind(clnt); 2130 /* 2131 * Did our request time out due to an RPCSEC_GSS out-of-sequence 2132 * event? RFC2203 requires the server to drop all such requests. 2133 */ 2134 rpcauth_invalcred(task); 2135 2136 retry: 2137 task->tk_action = call_bind; 2138 task->tk_status = 0; 2139 } 2140 2141 /* 2142 * 7. Decode the RPC reply 2143 */ 2144 static void 2145 call_decode(struct rpc_task *task) 2146 { 2147 struct rpc_clnt *clnt = task->tk_client; 2148 struct rpc_rqst *req = task->tk_rqstp; 2149 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode; 2150 __be32 *p; 2151 2152 dprint_status(task); 2153 2154 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 2155 if (clnt->cl_chatty) { 2156 rcu_read_lock(); 2157 printk(KERN_NOTICE "%s: server %s OK\n", 2158 clnt->cl_program->name, 2159 rcu_dereference(clnt->cl_xprt)->servername); 2160 rcu_read_unlock(); 2161 } 2162 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 2163 } 2164 2165 /* 2166 * Ensure that we see all writes made by xprt_complete_rqst() 2167 * before it changed req->rq_reply_bytes_recvd. 2168 */ 2169 smp_rmb(); 2170 req->rq_rcv_buf.len = req->rq_private_buf.len; 2171 2172 /* Check that the softirq receive buffer is valid */ 2173 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 2174 sizeof(req->rq_rcv_buf)) != 0); 2175 2176 if (req->rq_rcv_buf.len < 12) { 2177 if (!RPC_IS_SOFT(task)) { 2178 task->tk_action = call_bind; 2179 goto out_retry; 2180 } 2181 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", 2182 clnt->cl_program->name, task->tk_status); 2183 task->tk_action = call_timeout; 2184 goto out_retry; 2185 } 2186 2187 p = rpc_verify_header(task); 2188 if (IS_ERR(p)) { 2189 if (p == ERR_PTR(-EAGAIN)) 2190 goto out_retry; 2191 return; 2192 } 2193 2194 task->tk_action = rpc_exit_task; 2195 2196 if (decode) { 2197 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 2198 task->tk_msg.rpc_resp); 2199 } 2200 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid, 2201 task->tk_status); 2202 return; 2203 out_retry: 2204 task->tk_status = 0; 2205 /* Note: rpc_verify_header() may have freed the RPC slot */ 2206 if (task->tk_rqstp == req) { 2207 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0; 2208 if (task->tk_client->cl_discrtry) 2209 xprt_conditional_disconnect(req->rq_xprt, 2210 req->rq_connect_cookie); 2211 } 2212 } 2213 2214 static __be32 * 2215 rpc_encode_header(struct rpc_task *task) 2216 { 2217 struct rpc_clnt *clnt = task->tk_client; 2218 struct rpc_rqst *req = task->tk_rqstp; 2219 __be32 *p = req->rq_svec[0].iov_base; 2220 2221 /* FIXME: check buffer size? */ 2222 2223 p = xprt_skip_transport_header(req->rq_xprt, p); 2224 *p++ = req->rq_xid; /* XID */ 2225 *p++ = htonl(RPC_CALL); /* CALL */ 2226 *p++ = htonl(RPC_VERSION); /* RPC version */ 2227 *p++ = htonl(clnt->cl_prog); /* program number */ 2228 *p++ = htonl(clnt->cl_vers); /* program version */ 2229 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 2230 p = rpcauth_marshcred(task, p); 2231 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 2232 return p; 2233 } 2234 2235 static __be32 * 2236 rpc_verify_header(struct rpc_task *task) 2237 { 2238 struct rpc_clnt *clnt = task->tk_client; 2239 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 2240 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 2241 __be32 *p = iov->iov_base; 2242 u32 n; 2243 int error = -EACCES; 2244 2245 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 2246 /* RFC-1014 says that the representation of XDR data must be a 2247 * multiple of four bytes 2248 * - if it isn't pointer subtraction in the NFS client may give 2249 * undefined results 2250 */ 2251 dprintk("RPC: %5u %s: XDR representation not a multiple of" 2252 " 4 bytes: 0x%x\n", task->tk_pid, __func__, 2253 task->tk_rqstp->rq_rcv_buf.len); 2254 error = -EIO; 2255 goto out_err; 2256 } 2257 if ((len -= 3) < 0) 2258 goto out_overflow; 2259 2260 p += 1; /* skip XID */ 2261 if ((n = ntohl(*p++)) != RPC_REPLY) { 2262 dprintk("RPC: %5u %s: not an RPC reply: %x\n", 2263 task->tk_pid, __func__, n); 2264 error = -EIO; 2265 goto out_garbage; 2266 } 2267 2268 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 2269 if (--len < 0) 2270 goto out_overflow; 2271 switch ((n = ntohl(*p++))) { 2272 case RPC_AUTH_ERROR: 2273 break; 2274 case RPC_MISMATCH: 2275 dprintk("RPC: %5u %s: RPC call version mismatch!\n", 2276 task->tk_pid, __func__); 2277 error = -EPROTONOSUPPORT; 2278 goto out_err; 2279 default: 2280 dprintk("RPC: %5u %s: RPC call rejected, " 2281 "unknown error: %x\n", 2282 task->tk_pid, __func__, n); 2283 error = -EIO; 2284 goto out_err; 2285 } 2286 if (--len < 0) 2287 goto out_overflow; 2288 switch ((n = ntohl(*p++))) { 2289 case RPC_AUTH_REJECTEDCRED: 2290 case RPC_AUTH_REJECTEDVERF: 2291 case RPCSEC_GSS_CREDPROBLEM: 2292 case RPCSEC_GSS_CTXPROBLEM: 2293 if (!task->tk_cred_retry) 2294 break; 2295 task->tk_cred_retry--; 2296 dprintk("RPC: %5u %s: retry stale creds\n", 2297 task->tk_pid, __func__); 2298 rpcauth_invalcred(task); 2299 /* Ensure we obtain a new XID! */ 2300 xprt_release(task); 2301 task->tk_action = call_reserve; 2302 goto out_retry; 2303 case RPC_AUTH_BADCRED: 2304 case RPC_AUTH_BADVERF: 2305 /* possibly garbled cred/verf? */ 2306 if (!task->tk_garb_retry) 2307 break; 2308 task->tk_garb_retry--; 2309 dprintk("RPC: %5u %s: retry garbled creds\n", 2310 task->tk_pid, __func__); 2311 task->tk_action = call_bind; 2312 goto out_retry; 2313 case RPC_AUTH_TOOWEAK: 2314 rcu_read_lock(); 2315 printk(KERN_NOTICE "RPC: server %s requires stronger " 2316 "authentication.\n", 2317 rcu_dereference(clnt->cl_xprt)->servername); 2318 rcu_read_unlock(); 2319 break; 2320 default: 2321 dprintk("RPC: %5u %s: unknown auth error: %x\n", 2322 task->tk_pid, __func__, n); 2323 error = -EIO; 2324 } 2325 dprintk("RPC: %5u %s: call rejected %d\n", 2326 task->tk_pid, __func__, n); 2327 goto out_err; 2328 } 2329 p = rpcauth_checkverf(task, p); 2330 if (IS_ERR(p)) { 2331 error = PTR_ERR(p); 2332 dprintk("RPC: %5u %s: auth check failed with %d\n", 2333 task->tk_pid, __func__, error); 2334 goto out_garbage; /* bad verifier, retry */ 2335 } 2336 len = p - (__be32 *)iov->iov_base - 1; 2337 if (len < 0) 2338 goto out_overflow; 2339 switch ((n = ntohl(*p++))) { 2340 case RPC_SUCCESS: 2341 return p; 2342 case RPC_PROG_UNAVAIL: 2343 dprintk_rcu("RPC: %5u %s: program %u is unsupported " 2344 "by server %s\n", task->tk_pid, __func__, 2345 (unsigned int)clnt->cl_prog, 2346 rcu_dereference(clnt->cl_xprt)->servername); 2347 error = -EPFNOSUPPORT; 2348 goto out_err; 2349 case RPC_PROG_MISMATCH: 2350 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported " 2351 "by server %s\n", task->tk_pid, __func__, 2352 (unsigned int)clnt->cl_prog, 2353 (unsigned int)clnt->cl_vers, 2354 rcu_dereference(clnt->cl_xprt)->servername); 2355 error = -EPROTONOSUPPORT; 2356 goto out_err; 2357 case RPC_PROC_UNAVAIL: 2358 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, " 2359 "version %u on server %s\n", 2360 task->tk_pid, __func__, 2361 rpc_proc_name(task), 2362 clnt->cl_prog, clnt->cl_vers, 2363 rcu_dereference(clnt->cl_xprt)->servername); 2364 error = -EOPNOTSUPP; 2365 goto out_err; 2366 case RPC_GARBAGE_ARGS: 2367 dprintk("RPC: %5u %s: server saw garbage\n", 2368 task->tk_pid, __func__); 2369 break; /* retry */ 2370 default: 2371 dprintk("RPC: %5u %s: server accept status: %x\n", 2372 task->tk_pid, __func__, n); 2373 /* Also retry */ 2374 } 2375 2376 out_garbage: 2377 clnt->cl_stats->rpcgarbage++; 2378 if (task->tk_garb_retry) { 2379 task->tk_garb_retry--; 2380 dprintk("RPC: %5u %s: retrying\n", 2381 task->tk_pid, __func__); 2382 task->tk_action = call_bind; 2383 out_retry: 2384 return ERR_PTR(-EAGAIN); 2385 } 2386 out_err: 2387 rpc_exit(task, error); 2388 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid, 2389 __func__, error); 2390 return ERR_PTR(error); 2391 out_overflow: 2392 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid, 2393 __func__); 2394 goto out_garbage; 2395 } 2396 2397 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj) 2398 { 2399 } 2400 2401 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj) 2402 { 2403 return 0; 2404 } 2405 2406 static struct rpc_procinfo rpcproc_null = { 2407 .p_encode = rpcproc_encode_null, 2408 .p_decode = rpcproc_decode_null, 2409 }; 2410 2411 static int rpc_ping(struct rpc_clnt *clnt) 2412 { 2413 struct rpc_message msg = { 2414 .rpc_proc = &rpcproc_null, 2415 }; 2416 int err; 2417 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 2418 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN); 2419 put_rpccred(msg.rpc_cred); 2420 return err; 2421 } 2422 2423 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags) 2424 { 2425 struct rpc_message msg = { 2426 .rpc_proc = &rpcproc_null, 2427 .rpc_cred = cred, 2428 }; 2429 struct rpc_task_setup task_setup_data = { 2430 .rpc_client = clnt, 2431 .rpc_message = &msg, 2432 .callback_ops = &rpc_default_ops, 2433 .flags = flags, 2434 }; 2435 return rpc_run_task(&task_setup_data); 2436 } 2437 EXPORT_SYMBOL_GPL(rpc_call_null); 2438 2439 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 2440 static void rpc_show_header(void) 2441 { 2442 printk(KERN_INFO "-pid- flgs status -client- --rqstp- " 2443 "-timeout ---ops--\n"); 2444 } 2445 2446 static void rpc_show_task(const struct rpc_clnt *clnt, 2447 const struct rpc_task *task) 2448 { 2449 const char *rpc_waitq = "none"; 2450 2451 if (RPC_IS_QUEUED(task)) 2452 rpc_waitq = rpc_qname(task->tk_waitqueue); 2453 2454 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n", 2455 task->tk_pid, task->tk_flags, task->tk_status, 2456 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops, 2457 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task), 2458 task->tk_action, rpc_waitq); 2459 } 2460 2461 void rpc_show_tasks(struct net *net) 2462 { 2463 struct rpc_clnt *clnt; 2464 struct rpc_task *task; 2465 int header = 0; 2466 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 2467 2468 spin_lock(&sn->rpc_client_lock); 2469 list_for_each_entry(clnt, &sn->all_clients, cl_clients) { 2470 spin_lock(&clnt->cl_lock); 2471 list_for_each_entry(task, &clnt->cl_tasks, tk_task) { 2472 if (!header) { 2473 rpc_show_header(); 2474 header++; 2475 } 2476 rpc_show_task(clnt, task); 2477 } 2478 spin_unlock(&clnt->cl_lock); 2479 } 2480 spin_unlock(&sn->rpc_client_lock); 2481 } 2482 #endif 2483 2484 #if IS_ENABLED(CONFIG_SUNRPC_SWAP) 2485 int 2486 rpc_clnt_swap_activate(struct rpc_clnt *clnt) 2487 { 2488 int ret = 0; 2489 struct rpc_xprt *xprt; 2490 2491 if (atomic_inc_return(&clnt->cl_swapper) == 1) { 2492 retry: 2493 rcu_read_lock(); 2494 xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); 2495 rcu_read_unlock(); 2496 if (!xprt) { 2497 /* 2498 * If we didn't get a reference, then we likely are 2499 * racing with a migration event. Wait for a grace 2500 * period and try again. 2501 */ 2502 synchronize_rcu(); 2503 goto retry; 2504 } 2505 2506 ret = xprt_enable_swap(xprt); 2507 xprt_put(xprt); 2508 } 2509 return ret; 2510 } 2511 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate); 2512 2513 void 2514 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt) 2515 { 2516 struct rpc_xprt *xprt; 2517 2518 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) { 2519 retry: 2520 rcu_read_lock(); 2521 xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); 2522 rcu_read_unlock(); 2523 if (!xprt) { 2524 /* 2525 * If we didn't get a reference, then we likely are 2526 * racing with a migration event. Wait for a grace 2527 * period and try again. 2528 */ 2529 synchronize_rcu(); 2530 goto retry; 2531 } 2532 2533 xprt_disable_swap(xprt); 2534 xprt_put(xprt); 2535 } 2536 } 2537 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate); 2538 #endif /* CONFIG_SUNRPC_SWAP */ 2539