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 struct lock_manager lockd_manager = { 91 }; 92 93 static void grace_ender(struct work_struct *not_used) 94 { 95 locks_end_grace(&lockd_manager); 96 } 97 98 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); 99 100 static void set_grace_period(void) 101 { 102 unsigned long grace_period = get_lockd_grace_period(); 103 104 locks_start_grace(&lockd_manager); 105 cancel_delayed_work_sync(&grace_period_end); 106 schedule_delayed_work(&grace_period_end, grace_period); 107 } 108 109 static void restart_grace(void) 110 { 111 if (nlmsvc_ops) { 112 cancel_delayed_work_sync(&grace_period_end); 113 locks_end_grace(&lockd_manager); 114 nlmsvc_invalidate_all(); 115 set_grace_period(); 116 } 117 } 118 119 /* 120 * This is the lockd kernel thread 121 */ 122 static int 123 lockd(void *vrqstp) 124 { 125 int err = 0, preverr = 0; 126 struct svc_rqst *rqstp = vrqstp; 127 128 /* try_to_freeze() is called from svc_recv() */ 129 set_freezable(); 130 131 /* Allow SIGKILL to tell lockd to drop all of its locks */ 132 allow_signal(SIGKILL); 133 134 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 135 136 if (!nlm_timeout) 137 nlm_timeout = LOCKD_DFLT_TIMEO; 138 nlmsvc_timeout = nlm_timeout * HZ; 139 140 set_grace_period(); 141 142 /* 143 * The main request loop. We don't terminate until the last 144 * NFS mount or NFS daemon has gone away. 145 */ 146 while (!kthread_should_stop()) { 147 long timeout = MAX_SCHEDULE_TIMEOUT; 148 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 149 150 /* update sv_maxconn if it has changed */ 151 rqstp->rq_server->sv_maxconn = nlm_max_connections; 152 153 if (signalled()) { 154 flush_signals(current); 155 restart_grace(); 156 continue; 157 } 158 159 timeout = nlmsvc_retry_blocked(); 160 161 /* 162 * Find a socket with data available and call its 163 * recvfrom routine. 164 */ 165 err = svc_recv(rqstp, timeout); 166 if (err == -EAGAIN || err == -EINTR) { 167 preverr = err; 168 continue; 169 } 170 if (err < 0) { 171 if (err != preverr) { 172 printk(KERN_WARNING "%s: unexpected error " 173 "from svc_recv (%d)\n", __func__, err); 174 preverr = err; 175 } 176 schedule_timeout_interruptible(HZ); 177 continue; 178 } 179 preverr = err; 180 181 dprintk("lockd: request from %s\n", 182 svc_print_addr(rqstp, buf, sizeof(buf))); 183 184 svc_process(rqstp); 185 } 186 flush_signals(current); 187 cancel_delayed_work_sync(&grace_period_end); 188 locks_end_grace(&lockd_manager); 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 net *net) 255 { 256 struct lockd_net *ln = net_generic(net, lockd_net_id); 257 struct svc_serv *serv = nlmsvc_rqst->rq_server; 258 int error; 259 260 if (ln->nlmsvc_users) 261 return 0; 262 263 error = svc_rpcb_setup(serv, net); 264 if (error) 265 goto err_rpcb; 266 267 error = make_socks(serv, net); 268 if (error < 0) 269 goto err_socks; 270 return 0; 271 272 err_socks: 273 svc_rpcb_cleanup(serv, net); 274 err_rpcb: 275 return error; 276 } 277 278 static void lockd_down_net(struct net *net) 279 { 280 struct lockd_net *ln = net_generic(net, lockd_net_id); 281 struct svc_serv *serv = nlmsvc_rqst->rq_server; 282 283 if (ln->nlmsvc_users) { 284 if (--ln->nlmsvc_users == 0) { 285 nlm_shutdown_hosts_net(net); 286 svc_shutdown_net(serv, net); 287 } 288 } else { 289 printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n", 290 nlmsvc_task, net); 291 BUG(); 292 } 293 } 294 295 /* 296 * Bring up the lockd process if it's not already up. 297 */ 298 int lockd_up(void) 299 { 300 struct svc_serv *serv; 301 int error = 0; 302 struct net *net = current->nsproxy->net_ns; 303 304 mutex_lock(&nlmsvc_mutex); 305 /* 306 * Check whether we're already up and running. 307 */ 308 if (nlmsvc_rqst) { 309 error = lockd_up_net(net); 310 goto out; 311 } 312 313 /* 314 * Sanity check: if there's no pid, 315 * we should be the first user ... 316 */ 317 if (nlmsvc_users) 318 printk(KERN_WARNING 319 "lockd_up: no pid, %d users??\n", nlmsvc_users); 320 321 error = -ENOMEM; 322 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 323 if (!serv) { 324 printk(KERN_WARNING "lockd_up: create service failed\n"); 325 goto out; 326 } 327 328 error = make_socks(serv, net); 329 if (error < 0) 330 goto destroy_and_out; 331 332 /* 333 * Create the kernel thread and wait for it to start. 334 */ 335 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); 336 if (IS_ERR(nlmsvc_rqst)) { 337 error = PTR_ERR(nlmsvc_rqst); 338 nlmsvc_rqst = NULL; 339 printk(KERN_WARNING 340 "lockd_up: svc_rqst allocation failed, error=%d\n", 341 error); 342 goto destroy_and_out; 343 } 344 345 svc_sock_update_bufs(serv); 346 serv->sv_maxconn = nlm_max_connections; 347 348 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 349 if (IS_ERR(nlmsvc_task)) { 350 error = PTR_ERR(nlmsvc_task); 351 svc_exit_thread(nlmsvc_rqst); 352 nlmsvc_task = NULL; 353 nlmsvc_rqst = NULL; 354 printk(KERN_WARNING 355 "lockd_up: kthread_run failed, error=%d\n", error); 356 goto destroy_and_out; 357 } 358 359 /* 360 * Note: svc_serv structures have an initial use count of 1, 361 * so we exit through here on both success and failure. 362 */ 363 destroy_and_out: 364 svc_destroy(serv); 365 out: 366 if (!error) { 367 struct lockd_net *ln = net_generic(net, lockd_net_id); 368 369 ln->nlmsvc_users++; 370 nlmsvc_users++; 371 } 372 mutex_unlock(&nlmsvc_mutex); 373 return error; 374 } 375 EXPORT_SYMBOL_GPL(lockd_up); 376 377 /* 378 * Decrement the user count and bring down lockd if we're the last. 379 */ 380 void 381 lockd_down(void) 382 { 383 mutex_lock(&nlmsvc_mutex); 384 if (nlmsvc_users) { 385 if (--nlmsvc_users) { 386 lockd_down_net(current->nsproxy->net_ns); 387 goto out; 388 } 389 } else { 390 printk(KERN_ERR "lockd_down: no users! task=%p\n", 391 nlmsvc_task); 392 BUG(); 393 } 394 395 if (!nlmsvc_task) { 396 printk(KERN_ERR "lockd_down: no lockd running.\n"); 397 BUG(); 398 } 399 kthread_stop(nlmsvc_task); 400 svc_exit_thread(nlmsvc_rqst); 401 nlmsvc_task = NULL; 402 nlmsvc_rqst = NULL; 403 out: 404 mutex_unlock(&nlmsvc_mutex); 405 } 406 EXPORT_SYMBOL_GPL(lockd_down); 407 408 #ifdef CONFIG_SYSCTL 409 410 /* 411 * Sysctl parameters (same as module parameters, different interface). 412 */ 413 414 static ctl_table nlm_sysctls[] = { 415 { 416 .procname = "nlm_grace_period", 417 .data = &nlm_grace_period, 418 .maxlen = sizeof(unsigned long), 419 .mode = 0644, 420 .proc_handler = proc_doulongvec_minmax, 421 .extra1 = (unsigned long *) &nlm_grace_period_min, 422 .extra2 = (unsigned long *) &nlm_grace_period_max, 423 }, 424 { 425 .procname = "nlm_timeout", 426 .data = &nlm_timeout, 427 .maxlen = sizeof(unsigned long), 428 .mode = 0644, 429 .proc_handler = proc_doulongvec_minmax, 430 .extra1 = (unsigned long *) &nlm_timeout_min, 431 .extra2 = (unsigned long *) &nlm_timeout_max, 432 }, 433 { 434 .procname = "nlm_udpport", 435 .data = &nlm_udpport, 436 .maxlen = sizeof(int), 437 .mode = 0644, 438 .proc_handler = proc_dointvec_minmax, 439 .extra1 = (int *) &nlm_port_min, 440 .extra2 = (int *) &nlm_port_max, 441 }, 442 { 443 .procname = "nlm_tcpport", 444 .data = &nlm_tcpport, 445 .maxlen = sizeof(int), 446 .mode = 0644, 447 .proc_handler = proc_dointvec_minmax, 448 .extra1 = (int *) &nlm_port_min, 449 .extra2 = (int *) &nlm_port_max, 450 }, 451 { 452 .procname = "nsm_use_hostnames", 453 .data = &nsm_use_hostnames, 454 .maxlen = sizeof(int), 455 .mode = 0644, 456 .proc_handler = proc_dointvec, 457 }, 458 { 459 .procname = "nsm_local_state", 460 .data = &nsm_local_state, 461 .maxlen = sizeof(int), 462 .mode = 0644, 463 .proc_handler = proc_dointvec, 464 }, 465 { } 466 }; 467 468 static ctl_table nlm_sysctl_dir[] = { 469 { 470 .procname = "nfs", 471 .mode = 0555, 472 .child = nlm_sysctls, 473 }, 474 { } 475 }; 476 477 static ctl_table nlm_sysctl_root[] = { 478 { 479 .procname = "fs", 480 .mode = 0555, 481 .child = nlm_sysctl_dir, 482 }, 483 { } 484 }; 485 486 #endif /* CONFIG_SYSCTL */ 487 488 /* 489 * Module (and sysfs) parameters. 490 */ 491 492 #define param_set_min_max(name, type, which_strtol, min, max) \ 493 static int param_set_##name(const char *val, struct kernel_param *kp) \ 494 { \ 495 char *endp; \ 496 __typeof__(type) num = which_strtol(val, &endp, 0); \ 497 if (endp == val || *endp || num < (min) || num > (max)) \ 498 return -EINVAL; \ 499 *((type *) kp->arg) = num; \ 500 return 0; \ 501 } 502 503 static inline int is_callback(u32 proc) 504 { 505 return proc == NLMPROC_GRANTED 506 || proc == NLMPROC_GRANTED_MSG 507 || proc == NLMPROC_TEST_RES 508 || proc == NLMPROC_LOCK_RES 509 || proc == NLMPROC_CANCEL_RES 510 || proc == NLMPROC_UNLOCK_RES 511 || proc == NLMPROC_NSM_NOTIFY; 512 } 513 514 515 static int lockd_authenticate(struct svc_rqst *rqstp) 516 { 517 rqstp->rq_client = NULL; 518 switch (rqstp->rq_authop->flavour) { 519 case RPC_AUTH_NULL: 520 case RPC_AUTH_UNIX: 521 if (rqstp->rq_proc == 0) 522 return SVC_OK; 523 if (is_callback(rqstp->rq_proc)) { 524 /* Leave it to individual procedures to 525 * call nlmsvc_lookup_host(rqstp) 526 */ 527 return SVC_OK; 528 } 529 return svc_set_client(rqstp); 530 } 531 return SVC_DENIED; 532 } 533 534 535 param_set_min_max(port, int, simple_strtol, 0, 65535) 536 param_set_min_max(grace_period, unsigned long, simple_strtoul, 537 nlm_grace_period_min, nlm_grace_period_max) 538 param_set_min_max(timeout, unsigned long, simple_strtoul, 539 nlm_timeout_min, nlm_timeout_max) 540 541 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 542 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 543 MODULE_LICENSE("GPL"); 544 545 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 546 &nlm_grace_period, 0644); 547 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 548 &nlm_timeout, 0644); 549 module_param_call(nlm_udpport, param_set_port, param_get_int, 550 &nlm_udpport, 0644); 551 module_param_call(nlm_tcpport, param_set_port, param_get_int, 552 &nlm_tcpport, 0644); 553 module_param(nsm_use_hostnames, bool, 0644); 554 module_param(nlm_max_connections, uint, 0644); 555 556 static int lockd_init_net(struct net *net) 557 { 558 return 0; 559 } 560 561 static void lockd_exit_net(struct net *net) 562 { 563 } 564 565 static struct pernet_operations lockd_net_ops = { 566 .init = lockd_init_net, 567 .exit = lockd_exit_net, 568 .id = &lockd_net_id, 569 .size = sizeof(struct lockd_net), 570 }; 571 572 573 /* 574 * Initialising and terminating the module. 575 */ 576 577 static int __init init_nlm(void) 578 { 579 int err; 580 581 #ifdef CONFIG_SYSCTL 582 err = -ENOMEM; 583 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 584 if (nlm_sysctl_table == NULL) 585 goto err_sysctl; 586 #endif 587 err = register_pernet_subsys(&lockd_net_ops); 588 if (err) 589 goto err_pernet; 590 return 0; 591 592 err_pernet: 593 #ifdef CONFIG_SYSCTL 594 unregister_sysctl_table(nlm_sysctl_table); 595 #endif 596 err_sysctl: 597 return err; 598 } 599 600 static void __exit exit_nlm(void) 601 { 602 /* FIXME: delete all NLM clients */ 603 nlm_shutdown_hosts(); 604 unregister_pernet_subsys(&lockd_net_ops); 605 #ifdef CONFIG_SYSCTL 606 unregister_sysctl_table(nlm_sysctl_table); 607 #endif 608 } 609 610 module_init(init_nlm); 611 module_exit(exit_nlm); 612 613 /* 614 * Define NLM program and procedures 615 */ 616 static struct svc_version nlmsvc_version1 = { 617 .vs_vers = 1, 618 .vs_nproc = 17, 619 .vs_proc = nlmsvc_procedures, 620 .vs_xdrsize = NLMSVC_XDRSIZE, 621 }; 622 static struct svc_version nlmsvc_version3 = { 623 .vs_vers = 3, 624 .vs_nproc = 24, 625 .vs_proc = nlmsvc_procedures, 626 .vs_xdrsize = NLMSVC_XDRSIZE, 627 }; 628 #ifdef CONFIG_LOCKD_V4 629 static struct svc_version nlmsvc_version4 = { 630 .vs_vers = 4, 631 .vs_nproc = 24, 632 .vs_proc = nlmsvc_procedures4, 633 .vs_xdrsize = NLMSVC_XDRSIZE, 634 }; 635 #endif 636 static struct svc_version * nlmsvc_version[] = { 637 [1] = &nlmsvc_version1, 638 [3] = &nlmsvc_version3, 639 #ifdef CONFIG_LOCKD_V4 640 [4] = &nlmsvc_version4, 641 #endif 642 }; 643 644 static struct svc_stat nlmsvc_stats; 645 646 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 647 static struct svc_program nlmsvc_program = { 648 .pg_prog = NLM_PROGRAM, /* program number */ 649 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 650 .pg_vers = nlmsvc_version, /* version table */ 651 .pg_name = "lockd", /* service name */ 652 .pg_class = "nfsd", /* share authentication with nfsd */ 653 .pg_stats = &nlmsvc_stats, /* stats table */ 654 .pg_authenticate = &lockd_authenticate /* export authentication */ 655 }; 656