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