1 /* 2 * linux/fs/lockd/svc.c 3 * 4 * This is the central lockd service. 5 * 6 * FIXME: Separate the lockd NFS server functionality from the lockd NFS 7 * client functionality. Oh why didn't Sun create two separate 8 * services in the first place? 9 * 10 * Authors: Olaf Kirch (okir@monad.swb.de) 11 * 12 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> 13 */ 14 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/sysctl.h> 18 #include <linux/moduleparam.h> 19 20 #include <linux/sched.h> 21 #include <linux/errno.h> 22 #include <linux/in.h> 23 #include <linux/uio.h> 24 #include <linux/smp.h> 25 #include <linux/mutex.h> 26 #include <linux/kthread.h> 27 #include <linux/freezer.h> 28 29 #include <linux/sunrpc/types.h> 30 #include <linux/sunrpc/stats.h> 31 #include <linux/sunrpc/clnt.h> 32 #include <linux/sunrpc/svc.h> 33 #include <linux/sunrpc/svcsock.h> 34 #include <net/ip.h> 35 #include <linux/lockd/lockd.h> 36 #include <linux/nfs.h> 37 38 #include "netns.h" 39 #include "procfs.h" 40 41 #define NLMDBG_FACILITY NLMDBG_SVC 42 #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) 43 #define ALLOWED_SIGS (sigmask(SIGKILL)) 44 45 static struct svc_program nlmsvc_program; 46 47 struct nlmsvc_binding * nlmsvc_ops; 48 EXPORT_SYMBOL_GPL(nlmsvc_ops); 49 50 static DEFINE_MUTEX(nlmsvc_mutex); 51 static unsigned int nlmsvc_users; 52 static struct task_struct *nlmsvc_task; 53 static struct svc_rqst *nlmsvc_rqst; 54 unsigned long nlmsvc_timeout; 55 56 int lockd_net_id; 57 58 /* 59 * These can be set at insmod time (useful for NFS as root filesystem), 60 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 61 */ 62 static unsigned long nlm_grace_period; 63 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 64 static int nlm_udpport, nlm_tcpport; 65 66 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ 67 static unsigned int nlm_max_connections = 1024; 68 69 /* 70 * Constants needed for the sysctl interface. 71 */ 72 static const unsigned long nlm_grace_period_min = 0; 73 static const unsigned long nlm_grace_period_max = 240; 74 static const unsigned long nlm_timeout_min = 3; 75 static const unsigned long nlm_timeout_max = 20; 76 static const int nlm_port_min = 0, nlm_port_max = 65535; 77 78 #ifdef CONFIG_SYSCTL 79 static struct ctl_table_header * nlm_sysctl_table; 80 #endif 81 82 static unsigned long get_lockd_grace_period(void) 83 { 84 /* Note: nlm_timeout should always be nonzero */ 85 if (nlm_grace_period) 86 return roundup(nlm_grace_period, nlm_timeout) * HZ; 87 else 88 return nlm_timeout * 5 * HZ; 89 } 90 91 static void grace_ender(struct work_struct *grace) 92 { 93 struct delayed_work *dwork = container_of(grace, struct delayed_work, 94 work); 95 struct lockd_net *ln = container_of(dwork, struct lockd_net, 96 grace_period_end); 97 98 locks_end_grace(&ln->lockd_manager); 99 } 100 101 static void set_grace_period(struct net *net) 102 { 103 unsigned long grace_period = get_lockd_grace_period(); 104 struct lockd_net *ln = net_generic(net, lockd_net_id); 105 106 locks_start_grace(net, &ln->lockd_manager); 107 cancel_delayed_work_sync(&ln->grace_period_end); 108 schedule_delayed_work(&ln->grace_period_end, grace_period); 109 } 110 111 static void restart_grace(void) 112 { 113 if (nlmsvc_ops) { 114 struct net *net = &init_net; 115 struct lockd_net *ln = net_generic(net, lockd_net_id); 116 117 cancel_delayed_work_sync(&ln->grace_period_end); 118 locks_end_grace(&ln->lockd_manager); 119 nlmsvc_invalidate_all(); 120 set_grace_period(net); 121 } 122 } 123 124 /* 125 * This is the lockd kernel thread 126 */ 127 static int 128 lockd(void *vrqstp) 129 { 130 int err = 0; 131 struct svc_rqst *rqstp = vrqstp; 132 133 /* try_to_freeze() is called from svc_recv() */ 134 set_freezable(); 135 136 /* Allow SIGKILL to tell lockd to drop all of its locks */ 137 allow_signal(SIGKILL); 138 139 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 140 141 /* 142 * The main request loop. We don't terminate until the last 143 * NFS mount or NFS daemon has gone away. 144 */ 145 while (!kthread_should_stop()) { 146 long timeout = MAX_SCHEDULE_TIMEOUT; 147 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 148 149 /* update sv_maxconn if it has changed */ 150 rqstp->rq_server->sv_maxconn = nlm_max_connections; 151 152 if (signalled()) { 153 flush_signals(current); 154 restart_grace(); 155 continue; 156 } 157 158 timeout = nlmsvc_retry_blocked(); 159 160 /* 161 * Find a socket with data available and call its 162 * recvfrom routine. 163 */ 164 err = svc_recv(rqstp, timeout); 165 if (err == -EAGAIN || err == -EINTR) 166 continue; 167 dprintk("lockd: request from %s\n", 168 svc_print_addr(rqstp, buf, sizeof(buf))); 169 170 svc_process(rqstp); 171 } 172 flush_signals(current); 173 if (nlmsvc_ops) 174 nlmsvc_invalidate_all(); 175 nlm_shutdown_hosts(); 176 return 0; 177 } 178 179 static int create_lockd_listener(struct svc_serv *serv, const char *name, 180 struct net *net, const int family, 181 const unsigned short port) 182 { 183 struct svc_xprt *xprt; 184 185 xprt = svc_find_xprt(serv, name, net, family, 0); 186 if (xprt == NULL) 187 return svc_create_xprt(serv, name, net, family, port, 188 SVC_SOCK_DEFAULTS); 189 svc_xprt_put(xprt); 190 return 0; 191 } 192 193 static int create_lockd_family(struct svc_serv *serv, struct net *net, 194 const int family) 195 { 196 int err; 197 198 err = create_lockd_listener(serv, "udp", net, family, nlm_udpport); 199 if (err < 0) 200 return err; 201 202 return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport); 203 } 204 205 /* 206 * Ensure there are active UDP and TCP listeners for lockd. 207 * 208 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 209 * local services (such as rpc.statd) still require UDP, and 210 * some NFS servers do not yet support NLM over TCP. 211 * 212 * Returns zero if all listeners are available; otherwise a 213 * negative errno value is returned. 214 */ 215 static int make_socks(struct svc_serv *serv, struct net *net) 216 { 217 static int warned; 218 int err; 219 220 err = create_lockd_family(serv, net, PF_INET); 221 if (err < 0) 222 goto out_err; 223 224 err = create_lockd_family(serv, net, PF_INET6); 225 if (err < 0 && err != -EAFNOSUPPORT) 226 goto out_err; 227 228 warned = 0; 229 return 0; 230 231 out_err: 232 if (warned++ == 0) 233 printk(KERN_WARNING 234 "lockd_up: makesock failed, error=%d\n", err); 235 svc_shutdown_net(serv, net); 236 return err; 237 } 238 239 static int lockd_up_net(struct svc_serv *serv, struct net *net) 240 { 241 struct lockd_net *ln = net_generic(net, lockd_net_id); 242 int error; 243 244 if (ln->nlmsvc_users++) 245 return 0; 246 247 error = svc_bind(serv, net); 248 if (error) 249 goto err_bind; 250 251 error = make_socks(serv, net); 252 if (error < 0) 253 goto err_bind; 254 set_grace_period(net); 255 dprintk("lockd_up_net: per-net data created; net=%p\n", net); 256 return 0; 257 258 err_bind: 259 ln->nlmsvc_users--; 260 return error; 261 } 262 263 static void lockd_down_net(struct svc_serv *serv, struct net *net) 264 { 265 struct lockd_net *ln = net_generic(net, lockd_net_id); 266 267 if (ln->nlmsvc_users) { 268 if (--ln->nlmsvc_users == 0) { 269 nlm_shutdown_hosts_net(net); 270 cancel_delayed_work_sync(&ln->grace_period_end); 271 locks_end_grace(&ln->lockd_manager); 272 svc_shutdown_net(serv, net); 273 dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net); 274 } 275 } else { 276 printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n", 277 nlmsvc_task, net); 278 BUG(); 279 } 280 } 281 282 static int lockd_start_svc(struct svc_serv *serv) 283 { 284 int error; 285 286 if (nlmsvc_rqst) 287 return 0; 288 289 /* 290 * Create the kernel thread and wait for it to start. 291 */ 292 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); 293 if (IS_ERR(nlmsvc_rqst)) { 294 error = PTR_ERR(nlmsvc_rqst); 295 printk(KERN_WARNING 296 "lockd_up: svc_rqst allocation failed, error=%d\n", 297 error); 298 goto out_rqst; 299 } 300 301 svc_sock_update_bufs(serv); 302 serv->sv_maxconn = nlm_max_connections; 303 304 nlmsvc_task = kthread_create(lockd, nlmsvc_rqst, "%s", serv->sv_name); 305 if (IS_ERR(nlmsvc_task)) { 306 error = PTR_ERR(nlmsvc_task); 307 printk(KERN_WARNING 308 "lockd_up: kthread_run failed, error=%d\n", error); 309 goto out_task; 310 } 311 nlmsvc_rqst->rq_task = nlmsvc_task; 312 wake_up_process(nlmsvc_task); 313 314 dprintk("lockd_up: service started\n"); 315 return 0; 316 317 out_task: 318 svc_exit_thread(nlmsvc_rqst); 319 nlmsvc_task = NULL; 320 out_rqst: 321 nlmsvc_rqst = NULL; 322 return error; 323 } 324 325 static struct svc_serv_ops lockd_sv_ops = { 326 .svo_shutdown = svc_rpcb_cleanup, 327 .svo_enqueue_xprt = svc_xprt_do_enqueue, 328 }; 329 330 static struct svc_serv *lockd_create_svc(void) 331 { 332 struct svc_serv *serv; 333 334 /* 335 * Check whether we're already up and running. 336 */ 337 if (nlmsvc_rqst) { 338 /* 339 * Note: increase service usage, because later in case of error 340 * svc_destroy() will be called. 341 */ 342 svc_get(nlmsvc_rqst->rq_server); 343 return nlmsvc_rqst->rq_server; 344 } 345 346 /* 347 * Sanity check: if there's no pid, 348 * we should be the first user ... 349 */ 350 if (nlmsvc_users) 351 printk(KERN_WARNING 352 "lockd_up: no pid, %d users??\n", nlmsvc_users); 353 354 if (!nlm_timeout) 355 nlm_timeout = LOCKD_DFLT_TIMEO; 356 nlmsvc_timeout = nlm_timeout * HZ; 357 358 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, &lockd_sv_ops); 359 if (!serv) { 360 printk(KERN_WARNING "lockd_up: create service failed\n"); 361 return ERR_PTR(-ENOMEM); 362 } 363 dprintk("lockd_up: service created\n"); 364 return serv; 365 } 366 367 /* 368 * Bring up the lockd process if it's not already up. 369 */ 370 int lockd_up(struct net *net) 371 { 372 struct svc_serv *serv; 373 int error; 374 375 mutex_lock(&nlmsvc_mutex); 376 377 serv = lockd_create_svc(); 378 if (IS_ERR(serv)) { 379 error = PTR_ERR(serv); 380 goto err_create; 381 } 382 383 error = lockd_up_net(serv, net); 384 if (error < 0) 385 goto err_net; 386 387 error = lockd_start_svc(serv); 388 if (error < 0) 389 goto err_start; 390 391 nlmsvc_users++; 392 /* 393 * Note: svc_serv structures have an initial use count of 1, 394 * so we exit through here on both success and failure. 395 */ 396 err_net: 397 svc_destroy(serv); 398 err_create: 399 mutex_unlock(&nlmsvc_mutex); 400 return error; 401 402 err_start: 403 lockd_down_net(serv, net); 404 goto err_net; 405 } 406 EXPORT_SYMBOL_GPL(lockd_up); 407 408 /* 409 * Decrement the user count and bring down lockd if we're the last. 410 */ 411 void 412 lockd_down(struct net *net) 413 { 414 mutex_lock(&nlmsvc_mutex); 415 lockd_down_net(nlmsvc_rqst->rq_server, net); 416 if (nlmsvc_users) { 417 if (--nlmsvc_users) 418 goto out; 419 } else { 420 printk(KERN_ERR "lockd_down: no users! task=%p\n", 421 nlmsvc_task); 422 BUG(); 423 } 424 425 if (!nlmsvc_task) { 426 printk(KERN_ERR "lockd_down: no lockd running.\n"); 427 BUG(); 428 } 429 kthread_stop(nlmsvc_task); 430 dprintk("lockd_down: service stopped\n"); 431 svc_exit_thread(nlmsvc_rqst); 432 dprintk("lockd_down: service destroyed\n"); 433 nlmsvc_task = NULL; 434 nlmsvc_rqst = NULL; 435 out: 436 mutex_unlock(&nlmsvc_mutex); 437 } 438 EXPORT_SYMBOL_GPL(lockd_down); 439 440 #ifdef CONFIG_SYSCTL 441 442 /* 443 * Sysctl parameters (same as module parameters, different interface). 444 */ 445 446 static struct ctl_table nlm_sysctls[] = { 447 { 448 .procname = "nlm_grace_period", 449 .data = &nlm_grace_period, 450 .maxlen = sizeof(unsigned long), 451 .mode = 0644, 452 .proc_handler = proc_doulongvec_minmax, 453 .extra1 = (unsigned long *) &nlm_grace_period_min, 454 .extra2 = (unsigned long *) &nlm_grace_period_max, 455 }, 456 { 457 .procname = "nlm_timeout", 458 .data = &nlm_timeout, 459 .maxlen = sizeof(unsigned long), 460 .mode = 0644, 461 .proc_handler = proc_doulongvec_minmax, 462 .extra1 = (unsigned long *) &nlm_timeout_min, 463 .extra2 = (unsigned long *) &nlm_timeout_max, 464 }, 465 { 466 .procname = "nlm_udpport", 467 .data = &nlm_udpport, 468 .maxlen = sizeof(int), 469 .mode = 0644, 470 .proc_handler = proc_dointvec_minmax, 471 .extra1 = (int *) &nlm_port_min, 472 .extra2 = (int *) &nlm_port_max, 473 }, 474 { 475 .procname = "nlm_tcpport", 476 .data = &nlm_tcpport, 477 .maxlen = sizeof(int), 478 .mode = 0644, 479 .proc_handler = proc_dointvec_minmax, 480 .extra1 = (int *) &nlm_port_min, 481 .extra2 = (int *) &nlm_port_max, 482 }, 483 { 484 .procname = "nsm_use_hostnames", 485 .data = &nsm_use_hostnames, 486 .maxlen = sizeof(int), 487 .mode = 0644, 488 .proc_handler = proc_dointvec, 489 }, 490 { 491 .procname = "nsm_local_state", 492 .data = &nsm_local_state, 493 .maxlen = sizeof(int), 494 .mode = 0644, 495 .proc_handler = proc_dointvec, 496 }, 497 { } 498 }; 499 500 static struct ctl_table nlm_sysctl_dir[] = { 501 { 502 .procname = "nfs", 503 .mode = 0555, 504 .child = nlm_sysctls, 505 }, 506 { } 507 }; 508 509 static struct ctl_table nlm_sysctl_root[] = { 510 { 511 .procname = "fs", 512 .mode = 0555, 513 .child = nlm_sysctl_dir, 514 }, 515 { } 516 }; 517 518 #endif /* CONFIG_SYSCTL */ 519 520 /* 521 * Module (and sysfs) parameters. 522 */ 523 524 #define param_set_min_max(name, type, which_strtol, min, max) \ 525 static int param_set_##name(const char *val, struct kernel_param *kp) \ 526 { \ 527 char *endp; \ 528 __typeof__(type) num = which_strtol(val, &endp, 0); \ 529 if (endp == val || *endp || num < (min) || num > (max)) \ 530 return -EINVAL; \ 531 *((type *) kp->arg) = num; \ 532 return 0; \ 533 } 534 535 static inline int is_callback(u32 proc) 536 { 537 return proc == NLMPROC_GRANTED 538 || proc == NLMPROC_GRANTED_MSG 539 || proc == NLMPROC_TEST_RES 540 || proc == NLMPROC_LOCK_RES 541 || proc == NLMPROC_CANCEL_RES 542 || proc == NLMPROC_UNLOCK_RES 543 || proc == NLMPROC_NSM_NOTIFY; 544 } 545 546 547 static int lockd_authenticate(struct svc_rqst *rqstp) 548 { 549 rqstp->rq_client = NULL; 550 switch (rqstp->rq_authop->flavour) { 551 case RPC_AUTH_NULL: 552 case RPC_AUTH_UNIX: 553 if (rqstp->rq_proc == 0) 554 return SVC_OK; 555 if (is_callback(rqstp->rq_proc)) { 556 /* Leave it to individual procedures to 557 * call nlmsvc_lookup_host(rqstp) 558 */ 559 return SVC_OK; 560 } 561 return svc_set_client(rqstp); 562 } 563 return SVC_DENIED; 564 } 565 566 567 param_set_min_max(port, int, simple_strtol, 0, 65535) 568 param_set_min_max(grace_period, unsigned long, simple_strtoul, 569 nlm_grace_period_min, nlm_grace_period_max) 570 param_set_min_max(timeout, unsigned long, simple_strtoul, 571 nlm_timeout_min, nlm_timeout_max) 572 573 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 574 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 575 MODULE_LICENSE("GPL"); 576 577 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 578 &nlm_grace_period, 0644); 579 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 580 &nlm_timeout, 0644); 581 module_param_call(nlm_udpport, param_set_port, param_get_int, 582 &nlm_udpport, 0644); 583 module_param_call(nlm_tcpport, param_set_port, param_get_int, 584 &nlm_tcpport, 0644); 585 module_param(nsm_use_hostnames, bool, 0644); 586 module_param(nlm_max_connections, uint, 0644); 587 588 static int lockd_init_net(struct net *net) 589 { 590 struct lockd_net *ln = net_generic(net, lockd_net_id); 591 592 INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender); 593 INIT_LIST_HEAD(&ln->lockd_manager.list); 594 ln->lockd_manager.block_opens = false; 595 spin_lock_init(&ln->nsm_clnt_lock); 596 return 0; 597 } 598 599 static void lockd_exit_net(struct net *net) 600 { 601 } 602 603 static struct pernet_operations lockd_net_ops = { 604 .init = lockd_init_net, 605 .exit = lockd_exit_net, 606 .id = &lockd_net_id, 607 .size = sizeof(struct lockd_net), 608 }; 609 610 611 /* 612 * Initialising and terminating the module. 613 */ 614 615 static int __init init_nlm(void) 616 { 617 int err; 618 619 #ifdef CONFIG_SYSCTL 620 err = -ENOMEM; 621 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 622 if (nlm_sysctl_table == NULL) 623 goto err_sysctl; 624 #endif 625 err = register_pernet_subsys(&lockd_net_ops); 626 if (err) 627 goto err_pernet; 628 629 err = lockd_create_procfs(); 630 if (err) 631 goto err_procfs; 632 633 return 0; 634 635 err_procfs: 636 unregister_pernet_subsys(&lockd_net_ops); 637 err_pernet: 638 #ifdef CONFIG_SYSCTL 639 unregister_sysctl_table(nlm_sysctl_table); 640 err_sysctl: 641 #endif 642 return err; 643 } 644 645 static void __exit exit_nlm(void) 646 { 647 /* FIXME: delete all NLM clients */ 648 nlm_shutdown_hosts(); 649 lockd_remove_procfs(); 650 unregister_pernet_subsys(&lockd_net_ops); 651 #ifdef CONFIG_SYSCTL 652 unregister_sysctl_table(nlm_sysctl_table); 653 #endif 654 } 655 656 module_init(init_nlm); 657 module_exit(exit_nlm); 658 659 /* 660 * Define NLM program and procedures 661 */ 662 static struct svc_version nlmsvc_version1 = { 663 .vs_vers = 1, 664 .vs_nproc = 17, 665 .vs_proc = nlmsvc_procedures, 666 .vs_xdrsize = NLMSVC_XDRSIZE, 667 }; 668 static struct svc_version nlmsvc_version3 = { 669 .vs_vers = 3, 670 .vs_nproc = 24, 671 .vs_proc = nlmsvc_procedures, 672 .vs_xdrsize = NLMSVC_XDRSIZE, 673 }; 674 #ifdef CONFIG_LOCKD_V4 675 static struct svc_version nlmsvc_version4 = { 676 .vs_vers = 4, 677 .vs_nproc = 24, 678 .vs_proc = nlmsvc_procedures4, 679 .vs_xdrsize = NLMSVC_XDRSIZE, 680 }; 681 #endif 682 static struct svc_version * nlmsvc_version[] = { 683 [1] = &nlmsvc_version1, 684 [3] = &nlmsvc_version3, 685 #ifdef CONFIG_LOCKD_V4 686 [4] = &nlmsvc_version4, 687 #endif 688 }; 689 690 static struct svc_stat nlmsvc_stats; 691 692 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 693 static struct svc_program nlmsvc_program = { 694 .pg_prog = NLM_PROGRAM, /* program number */ 695 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 696 .pg_vers = nlmsvc_version, /* version table */ 697 .pg_name = "lockd", /* service name */ 698 .pg_class = "nfsd", /* share authentication with nfsd */ 699 .pg_stats = &nlmsvc_stats, /* stats table */ 700 .pg_authenticate = &lockd_authenticate /* export authentication */ 701 }; 702