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