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; 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 continue; 170 dprintk("lockd: request from %s\n", 171 svc_print_addr(rqstp, buf, sizeof(buf))); 172 173 svc_process(rqstp); 174 } 175 flush_signals(current); 176 if (nlmsvc_ops) 177 nlmsvc_invalidate_all(); 178 nlm_shutdown_hosts(); 179 return 0; 180 } 181 182 static int create_lockd_listener(struct svc_serv *serv, const char *name, 183 struct net *net, const int family, 184 const unsigned short port) 185 { 186 struct svc_xprt *xprt; 187 188 xprt = svc_find_xprt(serv, name, net, family, 0); 189 if (xprt == NULL) 190 return svc_create_xprt(serv, name, net, family, port, 191 SVC_SOCK_DEFAULTS); 192 svc_xprt_put(xprt); 193 return 0; 194 } 195 196 static int create_lockd_family(struct svc_serv *serv, struct net *net, 197 const int family) 198 { 199 int err; 200 201 err = create_lockd_listener(serv, "udp", net, family, nlm_udpport); 202 if (err < 0) 203 return err; 204 205 return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport); 206 } 207 208 /* 209 * Ensure there are active UDP and TCP listeners for lockd. 210 * 211 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 212 * local services (such as rpc.statd) still require UDP, and 213 * some NFS servers do not yet support NLM over TCP. 214 * 215 * Returns zero if all listeners are available; otherwise a 216 * negative errno value is returned. 217 */ 218 static int make_socks(struct svc_serv *serv, struct net *net) 219 { 220 static int warned; 221 int err; 222 223 err = create_lockd_family(serv, net, PF_INET); 224 if (err < 0) 225 goto out_err; 226 227 err = create_lockd_family(serv, net, PF_INET6); 228 if (err < 0 && err != -EAFNOSUPPORT) 229 goto out_err; 230 231 warned = 0; 232 return 0; 233 234 out_err: 235 if (warned++ == 0) 236 printk(KERN_WARNING 237 "lockd_up: makesock failed, error=%d\n", err); 238 return err; 239 } 240 241 static int lockd_up_net(struct svc_serv *serv, struct net *net) 242 { 243 struct lockd_net *ln = net_generic(net, lockd_net_id); 244 int error; 245 246 if (ln->nlmsvc_users++) 247 return 0; 248 249 error = svc_bind(serv, net); 250 if (error) 251 goto err_bind; 252 253 error = make_socks(serv, net); 254 if (error < 0) 255 goto err_socks; 256 set_grace_period(net); 257 dprintk("lockd_up_net: per-net data created; net=%p\n", net); 258 return 0; 259 260 err_socks: 261 svc_rpcb_cleanup(serv, net); 262 err_bind: 263 ln->nlmsvc_users--; 264 return error; 265 } 266 267 static void lockd_down_net(struct svc_serv *serv, struct net *net) 268 { 269 struct lockd_net *ln = net_generic(net, lockd_net_id); 270 271 if (ln->nlmsvc_users) { 272 if (--ln->nlmsvc_users == 0) { 273 nlm_shutdown_hosts_net(net); 274 cancel_delayed_work_sync(&ln->grace_period_end); 275 locks_end_grace(&ln->lockd_manager); 276 svc_shutdown_net(serv, net); 277 dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net); 278 } 279 } else { 280 printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n", 281 nlmsvc_task, net); 282 BUG(); 283 } 284 } 285 286 static int lockd_start_svc(struct svc_serv *serv) 287 { 288 int error; 289 290 if (nlmsvc_rqst) 291 return 0; 292 293 /* 294 * Create the kernel thread and wait for it to start. 295 */ 296 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); 297 if (IS_ERR(nlmsvc_rqst)) { 298 error = PTR_ERR(nlmsvc_rqst); 299 printk(KERN_WARNING 300 "lockd_up: svc_rqst allocation failed, error=%d\n", 301 error); 302 goto out_rqst; 303 } 304 305 svc_sock_update_bufs(serv); 306 serv->sv_maxconn = nlm_max_connections; 307 308 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 309 if (IS_ERR(nlmsvc_task)) { 310 error = PTR_ERR(nlmsvc_task); 311 printk(KERN_WARNING 312 "lockd_up: kthread_run failed, error=%d\n", error); 313 goto out_task; 314 } 315 dprintk("lockd_up: service started\n"); 316 return 0; 317 318 out_task: 319 svc_exit_thread(nlmsvc_rqst); 320 nlmsvc_task = NULL; 321 out_rqst: 322 nlmsvc_rqst = NULL; 323 return error; 324 } 325 326 static struct svc_serv *lockd_create_svc(void) 327 { 328 struct svc_serv *serv; 329 330 /* 331 * Check whether we're already up and running. 332 */ 333 if (nlmsvc_rqst) { 334 /* 335 * Note: increase service usage, because later in case of error 336 * svc_destroy() will be called. 337 */ 338 svc_get(nlmsvc_rqst->rq_server); 339 return nlmsvc_rqst->rq_server; 340 } 341 342 /* 343 * Sanity check: if there's no pid, 344 * we should be the first user ... 345 */ 346 if (nlmsvc_users) 347 printk(KERN_WARNING 348 "lockd_up: no pid, %d users??\n", nlmsvc_users); 349 350 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 351 if (!serv) { 352 printk(KERN_WARNING "lockd_up: create service failed\n"); 353 return ERR_PTR(-ENOMEM); 354 } 355 dprintk("lockd_up: service created\n"); 356 return serv; 357 } 358 359 /* 360 * Bring up the lockd process if it's not already up. 361 */ 362 int lockd_up(struct net *net) 363 { 364 struct svc_serv *serv; 365 int error; 366 367 mutex_lock(&nlmsvc_mutex); 368 369 serv = lockd_create_svc(); 370 if (IS_ERR(serv)) { 371 error = PTR_ERR(serv); 372 goto err_create; 373 } 374 375 error = lockd_up_net(serv, net); 376 if (error < 0) 377 goto err_net; 378 379 error = lockd_start_svc(serv); 380 if (error < 0) 381 goto err_start; 382 383 nlmsvc_users++; 384 /* 385 * Note: svc_serv structures have an initial use count of 1, 386 * so we exit through here on both success and failure. 387 */ 388 err_net: 389 svc_destroy(serv); 390 err_create: 391 mutex_unlock(&nlmsvc_mutex); 392 return error; 393 394 err_start: 395 lockd_down_net(serv, net); 396 goto err_net; 397 } 398 EXPORT_SYMBOL_GPL(lockd_up); 399 400 /* 401 * Decrement the user count and bring down lockd if we're the last. 402 */ 403 void 404 lockd_down(struct net *net) 405 { 406 mutex_lock(&nlmsvc_mutex); 407 lockd_down_net(nlmsvc_rqst->rq_server, net); 408 if (nlmsvc_users) { 409 if (--nlmsvc_users) 410 goto out; 411 } else { 412 printk(KERN_ERR "lockd_down: no users! task=%p\n", 413 nlmsvc_task); 414 BUG(); 415 } 416 417 if (!nlmsvc_task) { 418 printk(KERN_ERR "lockd_down: no lockd running.\n"); 419 BUG(); 420 } 421 kthread_stop(nlmsvc_task); 422 dprintk("lockd_down: service stopped\n"); 423 svc_exit_thread(nlmsvc_rqst); 424 dprintk("lockd_down: service destroyed\n"); 425 nlmsvc_task = NULL; 426 nlmsvc_rqst = NULL; 427 out: 428 mutex_unlock(&nlmsvc_mutex); 429 } 430 EXPORT_SYMBOL_GPL(lockd_down); 431 432 #ifdef CONFIG_SYSCTL 433 434 /* 435 * Sysctl parameters (same as module parameters, different interface). 436 */ 437 438 static ctl_table nlm_sysctls[] = { 439 { 440 .procname = "nlm_grace_period", 441 .data = &nlm_grace_period, 442 .maxlen = sizeof(unsigned long), 443 .mode = 0644, 444 .proc_handler = proc_doulongvec_minmax, 445 .extra1 = (unsigned long *) &nlm_grace_period_min, 446 .extra2 = (unsigned long *) &nlm_grace_period_max, 447 }, 448 { 449 .procname = "nlm_timeout", 450 .data = &nlm_timeout, 451 .maxlen = sizeof(unsigned long), 452 .mode = 0644, 453 .proc_handler = proc_doulongvec_minmax, 454 .extra1 = (unsigned long *) &nlm_timeout_min, 455 .extra2 = (unsigned long *) &nlm_timeout_max, 456 }, 457 { 458 .procname = "nlm_udpport", 459 .data = &nlm_udpport, 460 .maxlen = sizeof(int), 461 .mode = 0644, 462 .proc_handler = proc_dointvec_minmax, 463 .extra1 = (int *) &nlm_port_min, 464 .extra2 = (int *) &nlm_port_max, 465 }, 466 { 467 .procname = "nlm_tcpport", 468 .data = &nlm_tcpport, 469 .maxlen = sizeof(int), 470 .mode = 0644, 471 .proc_handler = proc_dointvec_minmax, 472 .extra1 = (int *) &nlm_port_min, 473 .extra2 = (int *) &nlm_port_max, 474 }, 475 { 476 .procname = "nsm_use_hostnames", 477 .data = &nsm_use_hostnames, 478 .maxlen = sizeof(int), 479 .mode = 0644, 480 .proc_handler = proc_dointvec, 481 }, 482 { 483 .procname = "nsm_local_state", 484 .data = &nsm_local_state, 485 .maxlen = sizeof(int), 486 .mode = 0644, 487 .proc_handler = proc_dointvec, 488 }, 489 { } 490 }; 491 492 static ctl_table nlm_sysctl_dir[] = { 493 { 494 .procname = "nfs", 495 .mode = 0555, 496 .child = nlm_sysctls, 497 }, 498 { } 499 }; 500 501 static ctl_table nlm_sysctl_root[] = { 502 { 503 .procname = "fs", 504 .mode = 0555, 505 .child = nlm_sysctl_dir, 506 }, 507 { } 508 }; 509 510 #endif /* CONFIG_SYSCTL */ 511 512 /* 513 * Module (and sysfs) parameters. 514 */ 515 516 #define param_set_min_max(name, type, which_strtol, min, max) \ 517 static int param_set_##name(const char *val, struct kernel_param *kp) \ 518 { \ 519 char *endp; \ 520 __typeof__(type) num = which_strtol(val, &endp, 0); \ 521 if (endp == val || *endp || num < (min) || num > (max)) \ 522 return -EINVAL; \ 523 *((type *) kp->arg) = num; \ 524 return 0; \ 525 } 526 527 static inline int is_callback(u32 proc) 528 { 529 return proc == NLMPROC_GRANTED 530 || proc == NLMPROC_GRANTED_MSG 531 || proc == NLMPROC_TEST_RES 532 || proc == NLMPROC_LOCK_RES 533 || proc == NLMPROC_CANCEL_RES 534 || proc == NLMPROC_UNLOCK_RES 535 || proc == NLMPROC_NSM_NOTIFY; 536 } 537 538 539 static int lockd_authenticate(struct svc_rqst *rqstp) 540 { 541 rqstp->rq_client = NULL; 542 switch (rqstp->rq_authop->flavour) { 543 case RPC_AUTH_NULL: 544 case RPC_AUTH_UNIX: 545 if (rqstp->rq_proc == 0) 546 return SVC_OK; 547 if (is_callback(rqstp->rq_proc)) { 548 /* Leave it to individual procedures to 549 * call nlmsvc_lookup_host(rqstp) 550 */ 551 return SVC_OK; 552 } 553 return svc_set_client(rqstp); 554 } 555 return SVC_DENIED; 556 } 557 558 559 param_set_min_max(port, int, simple_strtol, 0, 65535) 560 param_set_min_max(grace_period, unsigned long, simple_strtoul, 561 nlm_grace_period_min, nlm_grace_period_max) 562 param_set_min_max(timeout, unsigned long, simple_strtoul, 563 nlm_timeout_min, nlm_timeout_max) 564 565 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 566 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 567 MODULE_LICENSE("GPL"); 568 569 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 570 &nlm_grace_period, 0644); 571 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 572 &nlm_timeout, 0644); 573 module_param_call(nlm_udpport, param_set_port, param_get_int, 574 &nlm_udpport, 0644); 575 module_param_call(nlm_tcpport, param_set_port, param_get_int, 576 &nlm_tcpport, 0644); 577 module_param(nsm_use_hostnames, bool, 0644); 578 module_param(nlm_max_connections, uint, 0644); 579 580 static int lockd_init_net(struct net *net) 581 { 582 struct lockd_net *ln = net_generic(net, lockd_net_id); 583 584 INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender); 585 INIT_LIST_HEAD(&ln->grace_list); 586 spin_lock_init(&ln->nsm_clnt_lock); 587 return 0; 588 } 589 590 static void lockd_exit_net(struct net *net) 591 { 592 } 593 594 static struct pernet_operations lockd_net_ops = { 595 .init = lockd_init_net, 596 .exit = lockd_exit_net, 597 .id = &lockd_net_id, 598 .size = sizeof(struct lockd_net), 599 }; 600 601 602 /* 603 * Initialising and terminating the module. 604 */ 605 606 static int __init init_nlm(void) 607 { 608 int err; 609 610 #ifdef CONFIG_SYSCTL 611 err = -ENOMEM; 612 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 613 if (nlm_sysctl_table == NULL) 614 goto err_sysctl; 615 #endif 616 err = register_pernet_subsys(&lockd_net_ops); 617 if (err) 618 goto err_pernet; 619 return 0; 620 621 err_pernet: 622 #ifdef CONFIG_SYSCTL 623 unregister_sysctl_table(nlm_sysctl_table); 624 #endif 625 err_sysctl: 626 return err; 627 } 628 629 static void __exit exit_nlm(void) 630 { 631 /* FIXME: delete all NLM clients */ 632 nlm_shutdown_hosts(); 633 unregister_pernet_subsys(&lockd_net_ops); 634 #ifdef CONFIG_SYSCTL 635 unregister_sysctl_table(nlm_sysctl_table); 636 #endif 637 } 638 639 module_init(init_nlm); 640 module_exit(exit_nlm); 641 642 /* 643 * Define NLM program and procedures 644 */ 645 static struct svc_version nlmsvc_version1 = { 646 .vs_vers = 1, 647 .vs_nproc = 17, 648 .vs_proc = nlmsvc_procedures, 649 .vs_xdrsize = NLMSVC_XDRSIZE, 650 }; 651 static struct svc_version nlmsvc_version3 = { 652 .vs_vers = 3, 653 .vs_nproc = 24, 654 .vs_proc = nlmsvc_procedures, 655 .vs_xdrsize = NLMSVC_XDRSIZE, 656 }; 657 #ifdef CONFIG_LOCKD_V4 658 static struct svc_version nlmsvc_version4 = { 659 .vs_vers = 4, 660 .vs_nproc = 24, 661 .vs_proc = nlmsvc_procedures4, 662 .vs_xdrsize = NLMSVC_XDRSIZE, 663 }; 664 #endif 665 static struct svc_version * nlmsvc_version[] = { 666 [1] = &nlmsvc_version1, 667 [3] = &nlmsvc_version3, 668 #ifdef CONFIG_LOCKD_V4 669 [4] = &nlmsvc_version4, 670 #endif 671 }; 672 673 static struct svc_stat nlmsvc_stats; 674 675 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 676 static struct svc_program nlmsvc_program = { 677 .pg_prog = NLM_PROGRAM, /* program number */ 678 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 679 .pg_vers = nlmsvc_version, /* version table */ 680 .pg_name = "lockd", /* service name */ 681 .pg_class = "nfsd", /* share authentication with nfsd */ 682 .pg_stats = &nlmsvc_stats, /* stats table */ 683 .pg_authenticate = &lockd_authenticate /* export authentication */ 684 }; 685