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 = strlen(nodename); 290 if (clnt->cl_nodelen > UNX_MAXNODENAME) 291 clnt->cl_nodelen = UNX_MAXNODENAME; 292 memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen); 293 } 294 295 static int rpc_client_register(struct rpc_clnt *clnt, 296 rpc_authflavor_t pseudoflavor, 297 const char *client_name) 298 { 299 struct rpc_auth_create_args auth_args = { 300 .pseudoflavor = pseudoflavor, 301 .target_name = client_name, 302 }; 303 struct rpc_auth *auth; 304 struct net *net = rpc_net_ns(clnt); 305 struct super_block *pipefs_sb; 306 int err; 307 308 err = rpc_clnt_debugfs_register(clnt); 309 if (err) 310 return err; 311 312 pipefs_sb = rpc_get_sb_net(net); 313 if (pipefs_sb) { 314 err = rpc_setup_pipedir(pipefs_sb, clnt); 315 if (err) 316 goto out; 317 } 318 319 rpc_register_client(clnt); 320 if (pipefs_sb) 321 rpc_put_sb_net(net); 322 323 auth = rpcauth_create(&auth_args, clnt); 324 if (IS_ERR(auth)) { 325 dprintk("RPC: Couldn't create auth handle (flavor %u)\n", 326 pseudoflavor); 327 err = PTR_ERR(auth); 328 goto err_auth; 329 } 330 return 0; 331 err_auth: 332 pipefs_sb = rpc_get_sb_net(net); 333 rpc_unregister_client(clnt); 334 __rpc_clnt_remove_pipedir(clnt); 335 out: 336 if (pipefs_sb) 337 rpc_put_sb_net(net); 338 rpc_clnt_debugfs_unregister(clnt); 339 return err; 340 } 341 342 static DEFINE_IDA(rpc_clids); 343 344 static int rpc_alloc_clid(struct rpc_clnt *clnt) 345 { 346 int clid; 347 348 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL); 349 if (clid < 0) 350 return clid; 351 clnt->cl_clid = clid; 352 return 0; 353 } 354 355 static void rpc_free_clid(struct rpc_clnt *clnt) 356 { 357 ida_simple_remove(&rpc_clids, clnt->cl_clid); 358 } 359 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, 361 struct rpc_xprt *xprt, 362 struct rpc_clnt *parent) 363 { 364 const struct rpc_program *program = args->program; 365 const struct rpc_version *version; 366 struct rpc_clnt *clnt = NULL; 367 const struct rpc_timeout *timeout; 368 int err; 369 370 /* sanity check the name before trying to print it */ 371 dprintk("RPC: creating %s client for %s (xprt %p)\n", 372 program->name, args->servername, xprt); 373 374 err = rpciod_up(); 375 if (err) 376 goto out_no_rpciod; 377 378 err = -EINVAL; 379 if (args->version >= program->nrvers) 380 goto out_err; 381 version = program->version[args->version]; 382 if (version == NULL) 383 goto out_err; 384 385 err = -ENOMEM; 386 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 387 if (!clnt) 388 goto out_err; 389 clnt->cl_parent = parent ? : clnt; 390 391 err = rpc_alloc_clid(clnt); 392 if (err) 393 goto out_no_clid; 394 395 clnt->cl_procinfo = version->procs; 396 clnt->cl_maxproc = version->nrprocs; 397 clnt->cl_prog = args->prognumber ? : program->number; 398 clnt->cl_vers = version->number; 399 clnt->cl_stats = program->stats; 400 clnt->cl_metrics = rpc_alloc_iostats(clnt); 401 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects); 402 err = -ENOMEM; 403 if (clnt->cl_metrics == NULL) 404 goto out_no_stats; 405 clnt->cl_program = program; 406 INIT_LIST_HEAD(&clnt->cl_tasks); 407 spin_lock_init(&clnt->cl_lock); 408 409 timeout = xprt->timeout; 410 if (args->timeout != NULL) { 411 memcpy(&clnt->cl_timeout_default, args->timeout, 412 sizeof(clnt->cl_timeout_default)); 413 timeout = &clnt->cl_timeout_default; 414 } 415 416 rpc_clnt_set_transport(clnt, xprt, timeout); 417 418 clnt->cl_rtt = &clnt->cl_rtt_default; 419 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval); 420 421 atomic_set(&clnt->cl_count, 1); 422 423 /* save the nodename */ 424 rpc_clnt_set_nodename(clnt, utsname()->nodename); 425 426 err = rpc_client_register(clnt, args->authflavor, args->client_name); 427 if (err) 428 goto out_no_path; 429 if (parent) 430 atomic_inc(&parent->cl_count); 431 return clnt; 432 433 out_no_path: 434 rpc_free_iostats(clnt->cl_metrics); 435 out_no_stats: 436 rpc_free_clid(clnt); 437 out_no_clid: 438 kfree(clnt); 439 out_err: 440 rpciod_down(); 441 out_no_rpciod: 442 xprt_put(xprt); 443 return ERR_PTR(err); 444 } 445 446 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args, 447 struct rpc_xprt *xprt) 448 { 449 struct rpc_clnt *clnt = NULL; 450 451 clnt = rpc_new_client(args, xprt, NULL); 452 if (IS_ERR(clnt)) 453 return clnt; 454 455 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) { 456 int err = rpc_ping(clnt); 457 if (err != 0) { 458 rpc_shutdown_client(clnt); 459 return ERR_PTR(err); 460 } 461 } 462 463 clnt->cl_softrtry = 1; 464 if (args->flags & RPC_CLNT_CREATE_HARDRTRY) 465 clnt->cl_softrtry = 0; 466 467 if (args->flags & RPC_CLNT_CREATE_AUTOBIND) 468 clnt->cl_autobind = 1; 469 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT) 470 clnt->cl_noretranstimeo = 1; 471 if (args->flags & RPC_CLNT_CREATE_DISCRTRY) 472 clnt->cl_discrtry = 1; 473 if (!(args->flags & RPC_CLNT_CREATE_QUIET)) 474 clnt->cl_chatty = 1; 475 476 return clnt; 477 } 478 EXPORT_SYMBOL_GPL(rpc_create_xprt); 479 480 /** 481 * rpc_create - create an RPC client and transport with one call 482 * @args: rpc_clnt create argument structure 483 * 484 * Creates and initializes an RPC transport and an RPC client. 485 * 486 * It can ping the server in order to determine if it is up, and to see if 487 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables 488 * this behavior so asynchronous tasks can also use rpc_create. 489 */ 490 struct rpc_clnt *rpc_create(struct rpc_create_args *args) 491 { 492 struct rpc_xprt *xprt; 493 struct xprt_create xprtargs = { 494 .net = args->net, 495 .ident = args->protocol, 496 .srcaddr = args->saddress, 497 .dstaddr = args->address, 498 .addrlen = args->addrsize, 499 .servername = args->servername, 500 .bc_xprt = args->bc_xprt, 501 }; 502 char servername[48]; 503 504 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS) 505 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS; 506 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT) 507 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT; 508 /* 509 * If the caller chooses not to specify a hostname, whip 510 * up a string representation of the passed-in address. 511 */ 512 if (xprtargs.servername == NULL) { 513 struct sockaddr_un *sun = 514 (struct sockaddr_un *)args->address; 515 struct sockaddr_in *sin = 516 (struct sockaddr_in *)args->address; 517 struct sockaddr_in6 *sin6 = 518 (struct sockaddr_in6 *)args->address; 519 520 servername[0] = '\0'; 521 switch (args->address->sa_family) { 522 case AF_LOCAL: 523 snprintf(servername, sizeof(servername), "%s", 524 sun->sun_path); 525 break; 526 case AF_INET: 527 snprintf(servername, sizeof(servername), "%pI4", 528 &sin->sin_addr.s_addr); 529 break; 530 case AF_INET6: 531 snprintf(servername, sizeof(servername), "%pI6", 532 &sin6->sin6_addr); 533 break; 534 default: 535 /* caller wants default server name, but 536 * address family isn't recognized. */ 537 return ERR_PTR(-EINVAL); 538 } 539 xprtargs.servername = servername; 540 } 541 542 xprt = xprt_create_transport(&xprtargs); 543 if (IS_ERR(xprt)) 544 return (struct rpc_clnt *)xprt; 545 546 /* 547 * By default, kernel RPC client connects from a reserved port. 548 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters, 549 * but it is always enabled for rpciod, which handles the connect 550 * operation. 551 */ 552 xprt->resvport = 1; 553 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) 554 xprt->resvport = 0; 555 556 return rpc_create_xprt(args, xprt); 557 } 558 EXPORT_SYMBOL_GPL(rpc_create); 559 560 /* 561 * This function clones the RPC client structure. It allows us to share the 562 * same transport while varying parameters such as the authentication 563 * flavour. 564 */ 565 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args, 566 struct rpc_clnt *clnt) 567 { 568 struct rpc_xprt *xprt; 569 struct rpc_clnt *new; 570 int err; 571 572 err = -ENOMEM; 573 rcu_read_lock(); 574 xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); 575 rcu_read_unlock(); 576 if (xprt == NULL) 577 goto out_err; 578 args->servername = xprt->servername; 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 (sk_memalloc_socks()) { 895 struct rpc_xprt *xprt; 896 897 rcu_read_lock(); 898 xprt = rcu_dereference(clnt->cl_xprt); 899 if (xprt->swapper) 900 task->tk_flags |= RPC_TASK_SWAPPER; 901 rcu_read_unlock(); 902 } 903 /* Add to the client's list of all tasks */ 904 spin_lock(&clnt->cl_lock); 905 list_add_tail(&task->tk_task, &clnt->cl_tasks); 906 spin_unlock(&clnt->cl_lock); 907 } 908 } 909 910 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt) 911 { 912 rpc_task_release_client(task); 913 rpc_task_set_client(task, clnt); 914 } 915 EXPORT_SYMBOL_GPL(rpc_task_reset_client); 916 917 918 static void 919 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg) 920 { 921 if (msg != NULL) { 922 task->tk_msg.rpc_proc = msg->rpc_proc; 923 task->tk_msg.rpc_argp = msg->rpc_argp; 924 task->tk_msg.rpc_resp = msg->rpc_resp; 925 if (msg->rpc_cred != NULL) 926 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred); 927 } 928 } 929 930 /* 931 * Default callback for async RPC calls 932 */ 933 static void 934 rpc_default_callback(struct rpc_task *task, void *data) 935 { 936 } 937 938 static const struct rpc_call_ops rpc_default_ops = { 939 .rpc_call_done = rpc_default_callback, 940 }; 941 942 /** 943 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it 944 * @task_setup_data: pointer to task initialisation data 945 */ 946 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data) 947 { 948 struct rpc_task *task; 949 950 task = rpc_new_task(task_setup_data); 951 if (IS_ERR(task)) 952 goto out; 953 954 rpc_task_set_client(task, task_setup_data->rpc_client); 955 rpc_task_set_rpc_message(task, task_setup_data->rpc_message); 956 957 if (task->tk_action == NULL) 958 rpc_call_start(task); 959 960 atomic_inc(&task->tk_count); 961 rpc_execute(task); 962 out: 963 return task; 964 } 965 EXPORT_SYMBOL_GPL(rpc_run_task); 966 967 /** 968 * rpc_call_sync - Perform a synchronous RPC call 969 * @clnt: pointer to RPC client 970 * @msg: RPC call parameters 971 * @flags: RPC call flags 972 */ 973 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags) 974 { 975 struct rpc_task *task; 976 struct rpc_task_setup task_setup_data = { 977 .rpc_client = clnt, 978 .rpc_message = msg, 979 .callback_ops = &rpc_default_ops, 980 .flags = flags, 981 }; 982 int status; 983 984 WARN_ON_ONCE(flags & RPC_TASK_ASYNC); 985 if (flags & RPC_TASK_ASYNC) { 986 rpc_release_calldata(task_setup_data.callback_ops, 987 task_setup_data.callback_data); 988 return -EINVAL; 989 } 990 991 task = rpc_run_task(&task_setup_data); 992 if (IS_ERR(task)) 993 return PTR_ERR(task); 994 status = task->tk_status; 995 rpc_put_task(task); 996 return status; 997 } 998 EXPORT_SYMBOL_GPL(rpc_call_sync); 999 1000 /** 1001 * rpc_call_async - Perform an asynchronous RPC call 1002 * @clnt: pointer to RPC client 1003 * @msg: RPC call parameters 1004 * @flags: RPC call flags 1005 * @tk_ops: RPC call ops 1006 * @data: user call data 1007 */ 1008 int 1009 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags, 1010 const struct rpc_call_ops *tk_ops, void *data) 1011 { 1012 struct rpc_task *task; 1013 struct rpc_task_setup task_setup_data = { 1014 .rpc_client = clnt, 1015 .rpc_message = msg, 1016 .callback_ops = tk_ops, 1017 .callback_data = data, 1018 .flags = flags|RPC_TASK_ASYNC, 1019 }; 1020 1021 task = rpc_run_task(&task_setup_data); 1022 if (IS_ERR(task)) 1023 return PTR_ERR(task); 1024 rpc_put_task(task); 1025 return 0; 1026 } 1027 EXPORT_SYMBOL_GPL(rpc_call_async); 1028 1029 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1030 /** 1031 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run 1032 * rpc_execute against it 1033 * @req: RPC request 1034 * @tk_ops: RPC call ops 1035 */ 1036 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req, 1037 const struct rpc_call_ops *tk_ops) 1038 { 1039 struct rpc_task *task; 1040 struct xdr_buf *xbufp = &req->rq_snd_buf; 1041 struct rpc_task_setup task_setup_data = { 1042 .callback_ops = tk_ops, 1043 }; 1044 1045 dprintk("RPC: rpc_run_bc_task req= %p\n", req); 1046 /* 1047 * Create an rpc_task to send the data 1048 */ 1049 task = rpc_new_task(&task_setup_data); 1050 if (IS_ERR(task)) { 1051 xprt_free_bc_request(req); 1052 goto out; 1053 } 1054 task->tk_rqstp = req; 1055 1056 /* 1057 * Set up the xdr_buf length. 1058 * This also indicates that the buffer is XDR encoded already. 1059 */ 1060 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len + 1061 xbufp->tail[0].iov_len; 1062 1063 task->tk_action = call_bc_transmit; 1064 atomic_inc(&task->tk_count); 1065 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2); 1066 rpc_execute(task); 1067 1068 out: 1069 dprintk("RPC: rpc_run_bc_task: task= %p\n", task); 1070 return task; 1071 } 1072 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 1073 1074 void 1075 rpc_call_start(struct rpc_task *task) 1076 { 1077 task->tk_action = call_start; 1078 } 1079 EXPORT_SYMBOL_GPL(rpc_call_start); 1080 1081 /** 1082 * rpc_peeraddr - extract remote peer address from clnt's xprt 1083 * @clnt: RPC client structure 1084 * @buf: target buffer 1085 * @bufsize: length of target buffer 1086 * 1087 * Returns the number of bytes that are actually in the stored address. 1088 */ 1089 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize) 1090 { 1091 size_t bytes; 1092 struct rpc_xprt *xprt; 1093 1094 rcu_read_lock(); 1095 xprt = rcu_dereference(clnt->cl_xprt); 1096 1097 bytes = xprt->addrlen; 1098 if (bytes > bufsize) 1099 bytes = bufsize; 1100 memcpy(buf, &xprt->addr, bytes); 1101 rcu_read_unlock(); 1102 1103 return bytes; 1104 } 1105 EXPORT_SYMBOL_GPL(rpc_peeraddr); 1106 1107 /** 1108 * rpc_peeraddr2str - return remote peer address in printable format 1109 * @clnt: RPC client structure 1110 * @format: address format 1111 * 1112 * NB: the lifetime of the memory referenced by the returned pointer is 1113 * the same as the rpc_xprt itself. As long as the caller uses this 1114 * pointer, it must hold the RCU read lock. 1115 */ 1116 const char *rpc_peeraddr2str(struct rpc_clnt *clnt, 1117 enum rpc_display_format_t format) 1118 { 1119 struct rpc_xprt *xprt; 1120 1121 xprt = rcu_dereference(clnt->cl_xprt); 1122 1123 if (xprt->address_strings[format] != NULL) 1124 return xprt->address_strings[format]; 1125 else 1126 return "unprintable"; 1127 } 1128 EXPORT_SYMBOL_GPL(rpc_peeraddr2str); 1129 1130 static const struct sockaddr_in rpc_inaddr_loopback = { 1131 .sin_family = AF_INET, 1132 .sin_addr.s_addr = htonl(INADDR_ANY), 1133 }; 1134 1135 static const struct sockaddr_in6 rpc_in6addr_loopback = { 1136 .sin6_family = AF_INET6, 1137 .sin6_addr = IN6ADDR_ANY_INIT, 1138 }; 1139 1140 /* 1141 * Try a getsockname() on a connected datagram socket. Using a 1142 * connected datagram socket prevents leaving a socket in TIME_WAIT. 1143 * This conserves the ephemeral port number space. 1144 * 1145 * Returns zero and fills in "buf" if successful; otherwise, a 1146 * negative errno is returned. 1147 */ 1148 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen, 1149 struct sockaddr *buf, int buflen) 1150 { 1151 struct socket *sock; 1152 int err; 1153 1154 err = __sock_create(net, sap->sa_family, 1155 SOCK_DGRAM, IPPROTO_UDP, &sock, 1); 1156 if (err < 0) { 1157 dprintk("RPC: can't create UDP socket (%d)\n", err); 1158 goto out; 1159 } 1160 1161 switch (sap->sa_family) { 1162 case AF_INET: 1163 err = kernel_bind(sock, 1164 (struct sockaddr *)&rpc_inaddr_loopback, 1165 sizeof(rpc_inaddr_loopback)); 1166 break; 1167 case AF_INET6: 1168 err = kernel_bind(sock, 1169 (struct sockaddr *)&rpc_in6addr_loopback, 1170 sizeof(rpc_in6addr_loopback)); 1171 break; 1172 default: 1173 err = -EAFNOSUPPORT; 1174 goto out; 1175 } 1176 if (err < 0) { 1177 dprintk("RPC: can't bind UDP socket (%d)\n", err); 1178 goto out_release; 1179 } 1180 1181 err = kernel_connect(sock, sap, salen, 0); 1182 if (err < 0) { 1183 dprintk("RPC: can't connect UDP socket (%d)\n", err); 1184 goto out_release; 1185 } 1186 1187 err = kernel_getsockname(sock, buf, &buflen); 1188 if (err < 0) { 1189 dprintk("RPC: getsockname failed (%d)\n", err); 1190 goto out_release; 1191 } 1192 1193 err = 0; 1194 if (buf->sa_family == AF_INET6) { 1195 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf; 1196 sin6->sin6_scope_id = 0; 1197 } 1198 dprintk("RPC: %s succeeded\n", __func__); 1199 1200 out_release: 1201 sock_release(sock); 1202 out: 1203 return err; 1204 } 1205 1206 /* 1207 * Scraping a connected socket failed, so we don't have a useable 1208 * local address. Fallback: generate an address that will prevent 1209 * the server from calling us back. 1210 * 1211 * Returns zero and fills in "buf" if successful; otherwise, a 1212 * negative errno is returned. 1213 */ 1214 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen) 1215 { 1216 switch (family) { 1217 case AF_INET: 1218 if (buflen < sizeof(rpc_inaddr_loopback)) 1219 return -EINVAL; 1220 memcpy(buf, &rpc_inaddr_loopback, 1221 sizeof(rpc_inaddr_loopback)); 1222 break; 1223 case AF_INET6: 1224 if (buflen < sizeof(rpc_in6addr_loopback)) 1225 return -EINVAL; 1226 memcpy(buf, &rpc_in6addr_loopback, 1227 sizeof(rpc_in6addr_loopback)); 1228 default: 1229 dprintk("RPC: %s: address family not supported\n", 1230 __func__); 1231 return -EAFNOSUPPORT; 1232 } 1233 dprintk("RPC: %s: succeeded\n", __func__); 1234 return 0; 1235 } 1236 1237 /** 1238 * rpc_localaddr - discover local endpoint address for an RPC client 1239 * @clnt: RPC client structure 1240 * @buf: target buffer 1241 * @buflen: size of target buffer, in bytes 1242 * 1243 * Returns zero and fills in "buf" and "buflen" if successful; 1244 * otherwise, a negative errno is returned. 1245 * 1246 * This works even if the underlying transport is not currently connected, 1247 * or if the upper layer never previously provided a source address. 1248 * 1249 * The result of this function call is transient: multiple calls in 1250 * succession may give different results, depending on how local 1251 * networking configuration changes over time. 1252 */ 1253 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen) 1254 { 1255 struct sockaddr_storage address; 1256 struct sockaddr *sap = (struct sockaddr *)&address; 1257 struct rpc_xprt *xprt; 1258 struct net *net; 1259 size_t salen; 1260 int err; 1261 1262 rcu_read_lock(); 1263 xprt = rcu_dereference(clnt->cl_xprt); 1264 salen = xprt->addrlen; 1265 memcpy(sap, &xprt->addr, salen); 1266 net = get_net(xprt->xprt_net); 1267 rcu_read_unlock(); 1268 1269 rpc_set_port(sap, 0); 1270 err = rpc_sockname(net, sap, salen, buf, buflen); 1271 put_net(net); 1272 if (err != 0) 1273 /* Couldn't discover local address, return ANYADDR */ 1274 return rpc_anyaddr(sap->sa_family, buf, buflen); 1275 return 0; 1276 } 1277 EXPORT_SYMBOL_GPL(rpc_localaddr); 1278 1279 void 1280 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 1281 { 1282 struct rpc_xprt *xprt; 1283 1284 rcu_read_lock(); 1285 xprt = rcu_dereference(clnt->cl_xprt); 1286 if (xprt->ops->set_buffer_size) 1287 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 1288 rcu_read_unlock(); 1289 } 1290 EXPORT_SYMBOL_GPL(rpc_setbufsize); 1291 1292 /** 1293 * rpc_protocol - Get transport protocol number for an RPC client 1294 * @clnt: RPC client to query 1295 * 1296 */ 1297 int rpc_protocol(struct rpc_clnt *clnt) 1298 { 1299 int protocol; 1300 1301 rcu_read_lock(); 1302 protocol = rcu_dereference(clnt->cl_xprt)->prot; 1303 rcu_read_unlock(); 1304 return protocol; 1305 } 1306 EXPORT_SYMBOL_GPL(rpc_protocol); 1307 1308 /** 1309 * rpc_net_ns - Get the network namespace for this RPC client 1310 * @clnt: RPC client to query 1311 * 1312 */ 1313 struct net *rpc_net_ns(struct rpc_clnt *clnt) 1314 { 1315 struct net *ret; 1316 1317 rcu_read_lock(); 1318 ret = rcu_dereference(clnt->cl_xprt)->xprt_net; 1319 rcu_read_unlock(); 1320 return ret; 1321 } 1322 EXPORT_SYMBOL_GPL(rpc_net_ns); 1323 1324 /** 1325 * rpc_max_payload - Get maximum payload size for a transport, in bytes 1326 * @clnt: RPC client to query 1327 * 1328 * For stream transports, this is one RPC record fragment (see RFC 1329 * 1831), as we don't support multi-record requests yet. For datagram 1330 * transports, this is the size of an IP packet minus the IP, UDP, and 1331 * RPC header sizes. 1332 */ 1333 size_t rpc_max_payload(struct rpc_clnt *clnt) 1334 { 1335 size_t ret; 1336 1337 rcu_read_lock(); 1338 ret = rcu_dereference(clnt->cl_xprt)->max_payload; 1339 rcu_read_unlock(); 1340 return ret; 1341 } 1342 EXPORT_SYMBOL_GPL(rpc_max_payload); 1343 1344 /** 1345 * rpc_get_timeout - Get timeout for transport in units of HZ 1346 * @clnt: RPC client to query 1347 */ 1348 unsigned long rpc_get_timeout(struct rpc_clnt *clnt) 1349 { 1350 unsigned long ret; 1351 1352 rcu_read_lock(); 1353 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval; 1354 rcu_read_unlock(); 1355 return ret; 1356 } 1357 EXPORT_SYMBOL_GPL(rpc_get_timeout); 1358 1359 /** 1360 * rpc_force_rebind - force transport to check that remote port is unchanged 1361 * @clnt: client to rebind 1362 * 1363 */ 1364 void rpc_force_rebind(struct rpc_clnt *clnt) 1365 { 1366 if (clnt->cl_autobind) { 1367 rcu_read_lock(); 1368 xprt_clear_bound(rcu_dereference(clnt->cl_xprt)); 1369 rcu_read_unlock(); 1370 } 1371 } 1372 EXPORT_SYMBOL_GPL(rpc_force_rebind); 1373 1374 /* 1375 * Restart an (async) RPC call from the call_prepare state. 1376 * Usually called from within the exit handler. 1377 */ 1378 int 1379 rpc_restart_call_prepare(struct rpc_task *task) 1380 { 1381 if (RPC_ASSASSINATED(task)) 1382 return 0; 1383 task->tk_action = call_start; 1384 task->tk_status = 0; 1385 if (task->tk_ops->rpc_call_prepare != NULL) 1386 task->tk_action = rpc_prepare_task; 1387 return 1; 1388 } 1389 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare); 1390 1391 /* 1392 * Restart an (async) RPC call. Usually called from within the 1393 * exit handler. 1394 */ 1395 int 1396 rpc_restart_call(struct rpc_task *task) 1397 { 1398 if (RPC_ASSASSINATED(task)) 1399 return 0; 1400 task->tk_action = call_start; 1401 task->tk_status = 0; 1402 return 1; 1403 } 1404 EXPORT_SYMBOL_GPL(rpc_restart_call); 1405 1406 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 1407 const char 1408 *rpc_proc_name(const struct rpc_task *task) 1409 { 1410 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc; 1411 1412 if (proc) { 1413 if (proc->p_name) 1414 return proc->p_name; 1415 else 1416 return "NULL"; 1417 } else 1418 return "no proc"; 1419 } 1420 #endif 1421 1422 /* 1423 * 0. Initial state 1424 * 1425 * Other FSM states can be visited zero or more times, but 1426 * this state is visited exactly once for each RPC. 1427 */ 1428 static void 1429 call_start(struct rpc_task *task) 1430 { 1431 struct rpc_clnt *clnt = task->tk_client; 1432 1433 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid, 1434 clnt->cl_program->name, clnt->cl_vers, 1435 rpc_proc_name(task), 1436 (RPC_IS_ASYNC(task) ? "async" : "sync")); 1437 1438 /* Increment call count */ 1439 task->tk_msg.rpc_proc->p_count++; 1440 clnt->cl_stats->rpccnt++; 1441 task->tk_action = call_reserve; 1442 } 1443 1444 /* 1445 * 1. Reserve an RPC call slot 1446 */ 1447 static void 1448 call_reserve(struct rpc_task *task) 1449 { 1450 dprint_status(task); 1451 1452 task->tk_status = 0; 1453 task->tk_action = call_reserveresult; 1454 xprt_reserve(task); 1455 } 1456 1457 static void call_retry_reserve(struct rpc_task *task); 1458 1459 /* 1460 * 1b. Grok the result of xprt_reserve() 1461 */ 1462 static void 1463 call_reserveresult(struct rpc_task *task) 1464 { 1465 int status = task->tk_status; 1466 1467 dprint_status(task); 1468 1469 /* 1470 * After a call to xprt_reserve(), we must have either 1471 * a request slot or else an error status. 1472 */ 1473 task->tk_status = 0; 1474 if (status >= 0) { 1475 if (task->tk_rqstp) { 1476 task->tk_action = call_refresh; 1477 return; 1478 } 1479 1480 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 1481 __func__, status); 1482 rpc_exit(task, -EIO); 1483 return; 1484 } 1485 1486 /* 1487 * Even though there was an error, we may have acquired 1488 * a request slot somehow. Make sure not to leak it. 1489 */ 1490 if (task->tk_rqstp) { 1491 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 1492 __func__, status); 1493 xprt_release(task); 1494 } 1495 1496 switch (status) { 1497 case -ENOMEM: 1498 rpc_delay(task, HZ >> 2); 1499 case -EAGAIN: /* woken up; retry */ 1500 task->tk_action = call_retry_reserve; 1501 return; 1502 case -EIO: /* probably a shutdown */ 1503 break; 1504 default: 1505 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 1506 __func__, status); 1507 break; 1508 } 1509 rpc_exit(task, status); 1510 } 1511 1512 /* 1513 * 1c. Retry reserving an RPC call slot 1514 */ 1515 static void 1516 call_retry_reserve(struct rpc_task *task) 1517 { 1518 dprint_status(task); 1519 1520 task->tk_status = 0; 1521 task->tk_action = call_reserveresult; 1522 xprt_retry_reserve(task); 1523 } 1524 1525 /* 1526 * 2. Bind and/or refresh the credentials 1527 */ 1528 static void 1529 call_refresh(struct rpc_task *task) 1530 { 1531 dprint_status(task); 1532 1533 task->tk_action = call_refreshresult; 1534 task->tk_status = 0; 1535 task->tk_client->cl_stats->rpcauthrefresh++; 1536 rpcauth_refreshcred(task); 1537 } 1538 1539 /* 1540 * 2a. Process the results of a credential refresh 1541 */ 1542 static void 1543 call_refreshresult(struct rpc_task *task) 1544 { 1545 int status = task->tk_status; 1546 1547 dprint_status(task); 1548 1549 task->tk_status = 0; 1550 task->tk_action = call_refresh; 1551 switch (status) { 1552 case 0: 1553 if (rpcauth_uptodatecred(task)) { 1554 task->tk_action = call_allocate; 1555 return; 1556 } 1557 /* Use rate-limiting and a max number of retries if refresh 1558 * had status 0 but failed to update the cred. 1559 */ 1560 case -ETIMEDOUT: 1561 rpc_delay(task, 3*HZ); 1562 case -EAGAIN: 1563 status = -EACCES; 1564 case -EKEYEXPIRED: 1565 if (!task->tk_cred_retry) 1566 break; 1567 task->tk_cred_retry--; 1568 dprintk("RPC: %5u %s: retry refresh creds\n", 1569 task->tk_pid, __func__); 1570 return; 1571 } 1572 dprintk("RPC: %5u %s: refresh creds failed with error %d\n", 1573 task->tk_pid, __func__, status); 1574 rpc_exit(task, status); 1575 } 1576 1577 /* 1578 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc. 1579 * (Note: buffer memory is freed in xprt_release). 1580 */ 1581 static void 1582 call_allocate(struct rpc_task *task) 1583 { 1584 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack; 1585 struct rpc_rqst *req = task->tk_rqstp; 1586 struct rpc_xprt *xprt = req->rq_xprt; 1587 struct rpc_procinfo *proc = task->tk_msg.rpc_proc; 1588 1589 dprint_status(task); 1590 1591 task->tk_status = 0; 1592 task->tk_action = call_bind; 1593 1594 if (req->rq_buffer) 1595 return; 1596 1597 if (proc->p_proc != 0) { 1598 BUG_ON(proc->p_arglen == 0); 1599 if (proc->p_decode != NULL) 1600 BUG_ON(proc->p_replen == 0); 1601 } 1602 1603 /* 1604 * Calculate the size (in quads) of the RPC call 1605 * and reply headers, and convert both values 1606 * to byte sizes. 1607 */ 1608 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen; 1609 req->rq_callsize <<= 2; 1610 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen; 1611 req->rq_rcvsize <<= 2; 1612 1613 req->rq_buffer = xprt->ops->buf_alloc(task, 1614 req->rq_callsize + req->rq_rcvsize); 1615 if (req->rq_buffer != NULL) 1616 return; 1617 1618 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid); 1619 1620 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) { 1621 task->tk_action = call_allocate; 1622 rpc_delay(task, HZ>>4); 1623 return; 1624 } 1625 1626 rpc_exit(task, -ERESTARTSYS); 1627 } 1628 1629 static inline int 1630 rpc_task_need_encode(struct rpc_task *task) 1631 { 1632 return task->tk_rqstp->rq_snd_buf.len == 0; 1633 } 1634 1635 static inline void 1636 rpc_task_force_reencode(struct rpc_task *task) 1637 { 1638 task->tk_rqstp->rq_snd_buf.len = 0; 1639 task->tk_rqstp->rq_bytes_sent = 0; 1640 } 1641 1642 static inline void 1643 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len) 1644 { 1645 buf->head[0].iov_base = start; 1646 buf->head[0].iov_len = len; 1647 buf->tail[0].iov_len = 0; 1648 buf->page_len = 0; 1649 buf->flags = 0; 1650 buf->len = 0; 1651 buf->buflen = len; 1652 } 1653 1654 /* 1655 * 3. Encode arguments of an RPC call 1656 */ 1657 static void 1658 rpc_xdr_encode(struct rpc_task *task) 1659 { 1660 struct rpc_rqst *req = task->tk_rqstp; 1661 kxdreproc_t encode; 1662 __be32 *p; 1663 1664 dprint_status(task); 1665 1666 rpc_xdr_buf_init(&req->rq_snd_buf, 1667 req->rq_buffer, 1668 req->rq_callsize); 1669 rpc_xdr_buf_init(&req->rq_rcv_buf, 1670 (char *)req->rq_buffer + req->rq_callsize, 1671 req->rq_rcvsize); 1672 1673 p = rpc_encode_header(task); 1674 if (p == NULL) { 1675 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n"); 1676 rpc_exit(task, -EIO); 1677 return; 1678 } 1679 1680 encode = task->tk_msg.rpc_proc->p_encode; 1681 if (encode == NULL) 1682 return; 1683 1684 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 1685 task->tk_msg.rpc_argp); 1686 } 1687 1688 /* 1689 * 4. Get the server port number if not yet set 1690 */ 1691 static void 1692 call_bind(struct rpc_task *task) 1693 { 1694 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 1695 1696 dprint_status(task); 1697 1698 task->tk_action = call_connect; 1699 if (!xprt_bound(xprt)) { 1700 task->tk_action = call_bind_status; 1701 task->tk_timeout = xprt->bind_timeout; 1702 xprt->ops->rpcbind(task); 1703 } 1704 } 1705 1706 /* 1707 * 4a. Sort out bind result 1708 */ 1709 static void 1710 call_bind_status(struct rpc_task *task) 1711 { 1712 int status = -EIO; 1713 1714 if (task->tk_status >= 0) { 1715 dprint_status(task); 1716 task->tk_status = 0; 1717 task->tk_action = call_connect; 1718 return; 1719 } 1720 1721 trace_rpc_bind_status(task); 1722 switch (task->tk_status) { 1723 case -ENOMEM: 1724 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid); 1725 rpc_delay(task, HZ >> 2); 1726 goto retry_timeout; 1727 case -EACCES: 1728 dprintk("RPC: %5u remote rpcbind: RPC program/version " 1729 "unavailable\n", task->tk_pid); 1730 /* fail immediately if this is an RPC ping */ 1731 if (task->tk_msg.rpc_proc->p_proc == 0) { 1732 status = -EOPNOTSUPP; 1733 break; 1734 } 1735 if (task->tk_rebind_retry == 0) 1736 break; 1737 task->tk_rebind_retry--; 1738 rpc_delay(task, 3*HZ); 1739 goto retry_timeout; 1740 case -ETIMEDOUT: 1741 dprintk("RPC: %5u rpcbind request timed out\n", 1742 task->tk_pid); 1743 goto retry_timeout; 1744 case -EPFNOSUPPORT: 1745 /* server doesn't support any rpcbind version we know of */ 1746 dprintk("RPC: %5u unrecognized remote rpcbind service\n", 1747 task->tk_pid); 1748 break; 1749 case -EPROTONOSUPPORT: 1750 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n", 1751 task->tk_pid); 1752 goto retry_timeout; 1753 case -ECONNREFUSED: /* connection problems */ 1754 case -ECONNRESET: 1755 case -ECONNABORTED: 1756 case -ENOTCONN: 1757 case -EHOSTDOWN: 1758 case -EHOSTUNREACH: 1759 case -ENETUNREACH: 1760 case -ENOBUFS: 1761 case -EPIPE: 1762 dprintk("RPC: %5u remote rpcbind unreachable: %d\n", 1763 task->tk_pid, task->tk_status); 1764 if (!RPC_IS_SOFTCONN(task)) { 1765 rpc_delay(task, 5*HZ); 1766 goto retry_timeout; 1767 } 1768 status = task->tk_status; 1769 break; 1770 default: 1771 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n", 1772 task->tk_pid, -task->tk_status); 1773 } 1774 1775 rpc_exit(task, status); 1776 return; 1777 1778 retry_timeout: 1779 task->tk_status = 0; 1780 task->tk_action = call_timeout; 1781 } 1782 1783 /* 1784 * 4b. Connect to the RPC server 1785 */ 1786 static void 1787 call_connect(struct rpc_task *task) 1788 { 1789 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 1790 1791 dprintk("RPC: %5u call_connect xprt %p %s connected\n", 1792 task->tk_pid, xprt, 1793 (xprt_connected(xprt) ? "is" : "is not")); 1794 1795 task->tk_action = call_transmit; 1796 if (!xprt_connected(xprt)) { 1797 task->tk_action = call_connect_status; 1798 if (task->tk_status < 0) 1799 return; 1800 if (task->tk_flags & RPC_TASK_NOCONNECT) { 1801 rpc_exit(task, -ENOTCONN); 1802 return; 1803 } 1804 xprt_connect(task); 1805 } 1806 } 1807 1808 /* 1809 * 4c. Sort out connect result 1810 */ 1811 static void 1812 call_connect_status(struct rpc_task *task) 1813 { 1814 struct rpc_clnt *clnt = task->tk_client; 1815 int status = task->tk_status; 1816 1817 dprint_status(task); 1818 1819 trace_rpc_connect_status(task, status); 1820 task->tk_status = 0; 1821 switch (status) { 1822 case -ECONNREFUSED: 1823 case -ECONNRESET: 1824 case -ECONNABORTED: 1825 case -ENETUNREACH: 1826 case -EHOSTUNREACH: 1827 case -ENOBUFS: 1828 case -EPIPE: 1829 if (RPC_IS_SOFTCONN(task)) 1830 break; 1831 /* retry with existing socket, after a delay */ 1832 rpc_delay(task, 3*HZ); 1833 case -EAGAIN: 1834 /* Check for timeouts before looping back to call_bind */ 1835 case -ETIMEDOUT: 1836 task->tk_action = call_timeout; 1837 return; 1838 case 0: 1839 clnt->cl_stats->netreconn++; 1840 task->tk_action = call_transmit; 1841 return; 1842 } 1843 rpc_exit(task, status); 1844 } 1845 1846 /* 1847 * 5. Transmit the RPC request, and wait for reply 1848 */ 1849 static void 1850 call_transmit(struct rpc_task *task) 1851 { 1852 int is_retrans = RPC_WAS_SENT(task); 1853 1854 dprint_status(task); 1855 1856 task->tk_action = call_status; 1857 if (task->tk_status < 0) 1858 return; 1859 if (!xprt_prepare_transmit(task)) 1860 return; 1861 task->tk_action = call_transmit_status; 1862 /* Encode here so that rpcsec_gss can use correct sequence number. */ 1863 if (rpc_task_need_encode(task)) { 1864 rpc_xdr_encode(task); 1865 /* Did the encode result in an error condition? */ 1866 if (task->tk_status != 0) { 1867 /* Was the error nonfatal? */ 1868 if (task->tk_status == -EAGAIN) 1869 rpc_delay(task, HZ >> 4); 1870 else 1871 rpc_exit(task, task->tk_status); 1872 return; 1873 } 1874 } 1875 xprt_transmit(task); 1876 if (task->tk_status < 0) 1877 return; 1878 if (is_retrans) 1879 task->tk_client->cl_stats->rpcretrans++; 1880 /* 1881 * On success, ensure that we call xprt_end_transmit() before sleeping 1882 * in order to allow access to the socket to other RPC requests. 1883 */ 1884 call_transmit_status(task); 1885 if (rpc_reply_expected(task)) 1886 return; 1887 task->tk_action = rpc_exit_task; 1888 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task); 1889 } 1890 1891 /* 1892 * 5a. Handle cleanup after a transmission 1893 */ 1894 static void 1895 call_transmit_status(struct rpc_task *task) 1896 { 1897 task->tk_action = call_status; 1898 1899 /* 1900 * Common case: success. Force the compiler to put this 1901 * test first. 1902 */ 1903 if (task->tk_status == 0) { 1904 xprt_end_transmit(task); 1905 rpc_task_force_reencode(task); 1906 return; 1907 } 1908 1909 switch (task->tk_status) { 1910 case -EAGAIN: 1911 break; 1912 default: 1913 dprint_status(task); 1914 xprt_end_transmit(task); 1915 rpc_task_force_reencode(task); 1916 break; 1917 /* 1918 * Special cases: if we've been waiting on the 1919 * socket's write_space() callback, or if the 1920 * socket just returned a connection error, 1921 * then hold onto the transport lock. 1922 */ 1923 case -ECONNREFUSED: 1924 case -EHOSTDOWN: 1925 case -EHOSTUNREACH: 1926 case -ENETUNREACH: 1927 case -EPERM: 1928 if (RPC_IS_SOFTCONN(task)) { 1929 xprt_end_transmit(task); 1930 rpc_exit(task, task->tk_status); 1931 break; 1932 } 1933 case -ECONNRESET: 1934 case -ECONNABORTED: 1935 case -ENOTCONN: 1936 case -ENOBUFS: 1937 case -EPIPE: 1938 rpc_task_force_reencode(task); 1939 } 1940 } 1941 1942 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1943 /* 1944 * 5b. Send the backchannel RPC reply. On error, drop the reply. In 1945 * addition, disconnect on connectivity errors. 1946 */ 1947 static void 1948 call_bc_transmit(struct rpc_task *task) 1949 { 1950 struct rpc_rqst *req = task->tk_rqstp; 1951 1952 if (!xprt_prepare_transmit(task)) { 1953 /* 1954 * Could not reserve the transport. Try again after the 1955 * transport is released. 1956 */ 1957 task->tk_status = 0; 1958 task->tk_action = call_bc_transmit; 1959 return; 1960 } 1961 1962 task->tk_action = rpc_exit_task; 1963 if (task->tk_status < 0) { 1964 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1965 "error: %d\n", task->tk_status); 1966 return; 1967 } 1968 1969 xprt_transmit(task); 1970 xprt_end_transmit(task); 1971 dprint_status(task); 1972 switch (task->tk_status) { 1973 case 0: 1974 /* Success */ 1975 break; 1976 case -EHOSTDOWN: 1977 case -EHOSTUNREACH: 1978 case -ENETUNREACH: 1979 case -ETIMEDOUT: 1980 /* 1981 * Problem reaching the server. Disconnect and let the 1982 * forechannel reestablish the connection. The server will 1983 * have to retransmit the backchannel request and we'll 1984 * reprocess it. Since these ops are idempotent, there's no 1985 * need to cache our reply at this time. 1986 */ 1987 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1988 "error: %d\n", task->tk_status); 1989 xprt_conditional_disconnect(req->rq_xprt, 1990 req->rq_connect_cookie); 1991 break; 1992 default: 1993 /* 1994 * We were unable to reply and will have to drop the 1995 * request. The server should reconnect and retransmit. 1996 */ 1997 WARN_ON_ONCE(task->tk_status == -EAGAIN); 1998 printk(KERN_NOTICE "RPC: Could not send backchannel reply " 1999 "error: %d\n", task->tk_status); 2000 break; 2001 } 2002 rpc_wake_up_queued_task(&req->rq_xprt->pending, task); 2003 } 2004 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 2005 2006 /* 2007 * 6. Sort out the RPC call status 2008 */ 2009 static void 2010 call_status(struct rpc_task *task) 2011 { 2012 struct rpc_clnt *clnt = task->tk_client; 2013 struct rpc_rqst *req = task->tk_rqstp; 2014 int status; 2015 2016 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent) 2017 task->tk_status = req->rq_reply_bytes_recvd; 2018 2019 dprint_status(task); 2020 2021 status = task->tk_status; 2022 if (status >= 0) { 2023 task->tk_action = call_decode; 2024 return; 2025 } 2026 2027 trace_rpc_call_status(task); 2028 task->tk_status = 0; 2029 switch(status) { 2030 case -EHOSTDOWN: 2031 case -EHOSTUNREACH: 2032 case -ENETUNREACH: 2033 case -EPERM: 2034 if (RPC_IS_SOFTCONN(task)) { 2035 rpc_exit(task, status); 2036 break; 2037 } 2038 /* 2039 * Delay any retries for 3 seconds, then handle as if it 2040 * were a timeout. 2041 */ 2042 rpc_delay(task, 3*HZ); 2043 case -ETIMEDOUT: 2044 task->tk_action = call_timeout; 2045 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) 2046 && task->tk_client->cl_discrtry) 2047 xprt_conditional_disconnect(req->rq_xprt, 2048 req->rq_connect_cookie); 2049 break; 2050 case -ECONNREFUSED: 2051 case -ECONNRESET: 2052 case -ECONNABORTED: 2053 rpc_force_rebind(clnt); 2054 case -ENOBUFS: 2055 rpc_delay(task, 3*HZ); 2056 case -EPIPE: 2057 case -ENOTCONN: 2058 task->tk_action = call_bind; 2059 break; 2060 case -EAGAIN: 2061 task->tk_action = call_transmit; 2062 break; 2063 case -EIO: 2064 /* shutdown or soft timeout */ 2065 rpc_exit(task, status); 2066 break; 2067 default: 2068 if (clnt->cl_chatty) 2069 printk("%s: RPC call returned error %d\n", 2070 clnt->cl_program->name, -status); 2071 rpc_exit(task, status); 2072 } 2073 } 2074 2075 /* 2076 * 6a. Handle RPC timeout 2077 * We do not release the request slot, so we keep using the 2078 * same XID for all retransmits. 2079 */ 2080 static void 2081 call_timeout(struct rpc_task *task) 2082 { 2083 struct rpc_clnt *clnt = task->tk_client; 2084 2085 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 2086 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid); 2087 goto retry; 2088 } 2089 2090 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid); 2091 task->tk_timeouts++; 2092 2093 if (RPC_IS_SOFTCONN(task)) { 2094 rpc_exit(task, -ETIMEDOUT); 2095 return; 2096 } 2097 if (RPC_IS_SOFT(task)) { 2098 if (clnt->cl_chatty) { 2099 rcu_read_lock(); 2100 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 2101 clnt->cl_program->name, 2102 rcu_dereference(clnt->cl_xprt)->servername); 2103 rcu_read_unlock(); 2104 } 2105 if (task->tk_flags & RPC_TASK_TIMEOUT) 2106 rpc_exit(task, -ETIMEDOUT); 2107 else 2108 rpc_exit(task, -EIO); 2109 return; 2110 } 2111 2112 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 2113 task->tk_flags |= RPC_CALL_MAJORSEEN; 2114 if (clnt->cl_chatty) { 2115 rcu_read_lock(); 2116 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 2117 clnt->cl_program->name, 2118 rcu_dereference(clnt->cl_xprt)->servername); 2119 rcu_read_unlock(); 2120 } 2121 } 2122 rpc_force_rebind(clnt); 2123 /* 2124 * Did our request time out due to an RPCSEC_GSS out-of-sequence 2125 * event? RFC2203 requires the server to drop all such requests. 2126 */ 2127 rpcauth_invalcred(task); 2128 2129 retry: 2130 task->tk_action = call_bind; 2131 task->tk_status = 0; 2132 } 2133 2134 /* 2135 * 7. Decode the RPC reply 2136 */ 2137 static void 2138 call_decode(struct rpc_task *task) 2139 { 2140 struct rpc_clnt *clnt = task->tk_client; 2141 struct rpc_rqst *req = task->tk_rqstp; 2142 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode; 2143 __be32 *p; 2144 2145 dprint_status(task); 2146 2147 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 2148 if (clnt->cl_chatty) { 2149 rcu_read_lock(); 2150 printk(KERN_NOTICE "%s: server %s OK\n", 2151 clnt->cl_program->name, 2152 rcu_dereference(clnt->cl_xprt)->servername); 2153 rcu_read_unlock(); 2154 } 2155 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 2156 } 2157 2158 /* 2159 * Ensure that we see all writes made by xprt_complete_rqst() 2160 * before it changed req->rq_reply_bytes_recvd. 2161 */ 2162 smp_rmb(); 2163 req->rq_rcv_buf.len = req->rq_private_buf.len; 2164 2165 /* Check that the softirq receive buffer is valid */ 2166 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 2167 sizeof(req->rq_rcv_buf)) != 0); 2168 2169 if (req->rq_rcv_buf.len < 12) { 2170 if (!RPC_IS_SOFT(task)) { 2171 task->tk_action = call_bind; 2172 goto out_retry; 2173 } 2174 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n", 2175 clnt->cl_program->name, task->tk_status); 2176 task->tk_action = call_timeout; 2177 goto out_retry; 2178 } 2179 2180 p = rpc_verify_header(task); 2181 if (IS_ERR(p)) { 2182 if (p == ERR_PTR(-EAGAIN)) 2183 goto out_retry; 2184 return; 2185 } 2186 2187 task->tk_action = rpc_exit_task; 2188 2189 if (decode) { 2190 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 2191 task->tk_msg.rpc_resp); 2192 } 2193 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid, 2194 task->tk_status); 2195 return; 2196 out_retry: 2197 task->tk_status = 0; 2198 /* Note: rpc_verify_header() may have freed the RPC slot */ 2199 if (task->tk_rqstp == req) { 2200 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0; 2201 if (task->tk_client->cl_discrtry) 2202 xprt_conditional_disconnect(req->rq_xprt, 2203 req->rq_connect_cookie); 2204 } 2205 } 2206 2207 static __be32 * 2208 rpc_encode_header(struct rpc_task *task) 2209 { 2210 struct rpc_clnt *clnt = task->tk_client; 2211 struct rpc_rqst *req = task->tk_rqstp; 2212 __be32 *p = req->rq_svec[0].iov_base; 2213 2214 /* FIXME: check buffer size? */ 2215 2216 p = xprt_skip_transport_header(req->rq_xprt, p); 2217 *p++ = req->rq_xid; /* XID */ 2218 *p++ = htonl(RPC_CALL); /* CALL */ 2219 *p++ = htonl(RPC_VERSION); /* RPC version */ 2220 *p++ = htonl(clnt->cl_prog); /* program number */ 2221 *p++ = htonl(clnt->cl_vers); /* program version */ 2222 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 2223 p = rpcauth_marshcred(task, p); 2224 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 2225 return p; 2226 } 2227 2228 static __be32 * 2229 rpc_verify_header(struct rpc_task *task) 2230 { 2231 struct rpc_clnt *clnt = task->tk_client; 2232 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 2233 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 2234 __be32 *p = iov->iov_base; 2235 u32 n; 2236 int error = -EACCES; 2237 2238 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 2239 /* RFC-1014 says that the representation of XDR data must be a 2240 * multiple of four bytes 2241 * - if it isn't pointer subtraction in the NFS client may give 2242 * undefined results 2243 */ 2244 dprintk("RPC: %5u %s: XDR representation not a multiple of" 2245 " 4 bytes: 0x%x\n", task->tk_pid, __func__, 2246 task->tk_rqstp->rq_rcv_buf.len); 2247 error = -EIO; 2248 goto out_err; 2249 } 2250 if ((len -= 3) < 0) 2251 goto out_overflow; 2252 2253 p += 1; /* skip XID */ 2254 if ((n = ntohl(*p++)) != RPC_REPLY) { 2255 dprintk("RPC: %5u %s: not an RPC reply: %x\n", 2256 task->tk_pid, __func__, n); 2257 error = -EIO; 2258 goto out_garbage; 2259 } 2260 2261 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 2262 if (--len < 0) 2263 goto out_overflow; 2264 switch ((n = ntohl(*p++))) { 2265 case RPC_AUTH_ERROR: 2266 break; 2267 case RPC_MISMATCH: 2268 dprintk("RPC: %5u %s: RPC call version mismatch!\n", 2269 task->tk_pid, __func__); 2270 error = -EPROTONOSUPPORT; 2271 goto out_err; 2272 default: 2273 dprintk("RPC: %5u %s: RPC call rejected, " 2274 "unknown error: %x\n", 2275 task->tk_pid, __func__, n); 2276 error = -EIO; 2277 goto out_err; 2278 } 2279 if (--len < 0) 2280 goto out_overflow; 2281 switch ((n = ntohl(*p++))) { 2282 case RPC_AUTH_REJECTEDCRED: 2283 case RPC_AUTH_REJECTEDVERF: 2284 case RPCSEC_GSS_CREDPROBLEM: 2285 case RPCSEC_GSS_CTXPROBLEM: 2286 if (!task->tk_cred_retry) 2287 break; 2288 task->tk_cred_retry--; 2289 dprintk("RPC: %5u %s: retry stale creds\n", 2290 task->tk_pid, __func__); 2291 rpcauth_invalcred(task); 2292 /* Ensure we obtain a new XID! */ 2293 xprt_release(task); 2294 task->tk_action = call_reserve; 2295 goto out_retry; 2296 case RPC_AUTH_BADCRED: 2297 case RPC_AUTH_BADVERF: 2298 /* possibly garbled cred/verf? */ 2299 if (!task->tk_garb_retry) 2300 break; 2301 task->tk_garb_retry--; 2302 dprintk("RPC: %5u %s: retry garbled creds\n", 2303 task->tk_pid, __func__); 2304 task->tk_action = call_bind; 2305 goto out_retry; 2306 case RPC_AUTH_TOOWEAK: 2307 rcu_read_lock(); 2308 printk(KERN_NOTICE "RPC: server %s requires stronger " 2309 "authentication.\n", 2310 rcu_dereference(clnt->cl_xprt)->servername); 2311 rcu_read_unlock(); 2312 break; 2313 default: 2314 dprintk("RPC: %5u %s: unknown auth error: %x\n", 2315 task->tk_pid, __func__, n); 2316 error = -EIO; 2317 } 2318 dprintk("RPC: %5u %s: call rejected %d\n", 2319 task->tk_pid, __func__, n); 2320 goto out_err; 2321 } 2322 p = rpcauth_checkverf(task, p); 2323 if (IS_ERR(p)) { 2324 error = PTR_ERR(p); 2325 dprintk("RPC: %5u %s: auth check failed with %d\n", 2326 task->tk_pid, __func__, error); 2327 goto out_garbage; /* bad verifier, retry */ 2328 } 2329 len = p - (__be32 *)iov->iov_base - 1; 2330 if (len < 0) 2331 goto out_overflow; 2332 switch ((n = ntohl(*p++))) { 2333 case RPC_SUCCESS: 2334 return p; 2335 case RPC_PROG_UNAVAIL: 2336 dprintk_rcu("RPC: %5u %s: program %u is unsupported " 2337 "by server %s\n", task->tk_pid, __func__, 2338 (unsigned int)clnt->cl_prog, 2339 rcu_dereference(clnt->cl_xprt)->servername); 2340 error = -EPFNOSUPPORT; 2341 goto out_err; 2342 case RPC_PROG_MISMATCH: 2343 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported " 2344 "by server %s\n", task->tk_pid, __func__, 2345 (unsigned int)clnt->cl_prog, 2346 (unsigned int)clnt->cl_vers, 2347 rcu_dereference(clnt->cl_xprt)->servername); 2348 error = -EPROTONOSUPPORT; 2349 goto out_err; 2350 case RPC_PROC_UNAVAIL: 2351 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, " 2352 "version %u on server %s\n", 2353 task->tk_pid, __func__, 2354 rpc_proc_name(task), 2355 clnt->cl_prog, clnt->cl_vers, 2356 rcu_dereference(clnt->cl_xprt)->servername); 2357 error = -EOPNOTSUPP; 2358 goto out_err; 2359 case RPC_GARBAGE_ARGS: 2360 dprintk("RPC: %5u %s: server saw garbage\n", 2361 task->tk_pid, __func__); 2362 break; /* retry */ 2363 default: 2364 dprintk("RPC: %5u %s: server accept status: %x\n", 2365 task->tk_pid, __func__, n); 2366 /* Also retry */ 2367 } 2368 2369 out_garbage: 2370 clnt->cl_stats->rpcgarbage++; 2371 if (task->tk_garb_retry) { 2372 task->tk_garb_retry--; 2373 dprintk("RPC: %5u %s: retrying\n", 2374 task->tk_pid, __func__); 2375 task->tk_action = call_bind; 2376 out_retry: 2377 return ERR_PTR(-EAGAIN); 2378 } 2379 out_err: 2380 rpc_exit(task, error); 2381 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid, 2382 __func__, error); 2383 return ERR_PTR(error); 2384 out_overflow: 2385 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid, 2386 __func__); 2387 goto out_garbage; 2388 } 2389 2390 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj) 2391 { 2392 } 2393 2394 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj) 2395 { 2396 return 0; 2397 } 2398 2399 static struct rpc_procinfo rpcproc_null = { 2400 .p_encode = rpcproc_encode_null, 2401 .p_decode = rpcproc_decode_null, 2402 }; 2403 2404 static int rpc_ping(struct rpc_clnt *clnt) 2405 { 2406 struct rpc_message msg = { 2407 .rpc_proc = &rpcproc_null, 2408 }; 2409 int err; 2410 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 2411 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN); 2412 put_rpccred(msg.rpc_cred); 2413 return err; 2414 } 2415 2416 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags) 2417 { 2418 struct rpc_message msg = { 2419 .rpc_proc = &rpcproc_null, 2420 .rpc_cred = cred, 2421 }; 2422 struct rpc_task_setup task_setup_data = { 2423 .rpc_client = clnt, 2424 .rpc_message = &msg, 2425 .callback_ops = &rpc_default_ops, 2426 .flags = flags, 2427 }; 2428 return rpc_run_task(&task_setup_data); 2429 } 2430 EXPORT_SYMBOL_GPL(rpc_call_null); 2431 2432 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 2433 static void rpc_show_header(void) 2434 { 2435 printk(KERN_INFO "-pid- flgs status -client- --rqstp- " 2436 "-timeout ---ops--\n"); 2437 } 2438 2439 static void rpc_show_task(const struct rpc_clnt *clnt, 2440 const struct rpc_task *task) 2441 { 2442 const char *rpc_waitq = "none"; 2443 2444 if (RPC_IS_QUEUED(task)) 2445 rpc_waitq = rpc_qname(task->tk_waitqueue); 2446 2447 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n", 2448 task->tk_pid, task->tk_flags, task->tk_status, 2449 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops, 2450 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task), 2451 task->tk_action, rpc_waitq); 2452 } 2453 2454 void rpc_show_tasks(struct net *net) 2455 { 2456 struct rpc_clnt *clnt; 2457 struct rpc_task *task; 2458 int header = 0; 2459 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 2460 2461 spin_lock(&sn->rpc_client_lock); 2462 list_for_each_entry(clnt, &sn->all_clients, cl_clients) { 2463 spin_lock(&clnt->cl_lock); 2464 list_for_each_entry(task, &clnt->cl_tasks, tk_task) { 2465 if (!header) { 2466 rpc_show_header(); 2467 header++; 2468 } 2469 rpc_show_task(clnt, task); 2470 } 2471 spin_unlock(&clnt->cl_lock); 2472 } 2473 spin_unlock(&sn->rpc_client_lock); 2474 } 2475 #endif 2476