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/slab.h> 25 #include <linux/smp.h> 26 #include <linux/smp_lock.h> 27 #include <linux/mutex.h> 28 #include <linux/kthread.h> 29 #include <linux/freezer.h> 30 31 #include <linux/sunrpc/types.h> 32 #include <linux/sunrpc/stats.h> 33 #include <linux/sunrpc/clnt.h> 34 #include <linux/sunrpc/svc.h> 35 #include <linux/sunrpc/svcsock.h> 36 #include <net/ip.h> 37 #include <linux/lockd/lockd.h> 38 #include <linux/nfs.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 /* 56 * These can be set at insmod time (useful for NFS as root filesystem), 57 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 58 */ 59 static unsigned long nlm_grace_period; 60 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 61 static int nlm_udpport, nlm_tcpport; 62 63 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ 64 static unsigned int nlm_max_connections = 1024; 65 66 /* 67 * Constants needed for the sysctl interface. 68 */ 69 static const unsigned long nlm_grace_period_min = 0; 70 static const unsigned long nlm_grace_period_max = 240; 71 static const unsigned long nlm_timeout_min = 3; 72 static const unsigned long nlm_timeout_max = 20; 73 static const int nlm_port_min = 0, nlm_port_max = 65535; 74 75 #ifdef CONFIG_SYSCTL 76 static struct ctl_table_header * nlm_sysctl_table; 77 #endif 78 79 static unsigned long get_lockd_grace_period(void) 80 { 81 /* Note: nlm_timeout should always be nonzero */ 82 if (nlm_grace_period) 83 return roundup(nlm_grace_period, nlm_timeout) * HZ; 84 else 85 return nlm_timeout * 5 * HZ; 86 } 87 88 static struct lock_manager lockd_manager = { 89 }; 90 91 static void grace_ender(struct work_struct *not_used) 92 { 93 locks_end_grace(&lockd_manager); 94 } 95 96 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); 97 98 static void set_grace_period(void) 99 { 100 unsigned long grace_period = get_lockd_grace_period(); 101 102 locks_start_grace(&lockd_manager); 103 cancel_delayed_work_sync(&grace_period_end); 104 schedule_delayed_work(&grace_period_end, grace_period); 105 } 106 107 static void restart_grace(void) 108 { 109 if (nlmsvc_ops) { 110 cancel_delayed_work_sync(&grace_period_end); 111 locks_end_grace(&lockd_manager); 112 nlmsvc_invalidate_all(); 113 set_grace_period(); 114 } 115 } 116 117 /* 118 * This is the lockd kernel thread 119 */ 120 static int 121 lockd(void *vrqstp) 122 { 123 int err = 0, preverr = 0; 124 struct svc_rqst *rqstp = vrqstp; 125 126 /* try_to_freeze() is called from svc_recv() */ 127 set_freezable(); 128 129 /* Allow SIGKILL to tell lockd to drop all of its locks */ 130 allow_signal(SIGKILL); 131 132 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 133 134 /* 135 * FIXME: it would be nice if lockd didn't spend its entire life 136 * running under the BKL. At the very least, it would be good to 137 * have someone clarify what it's intended to protect here. I've 138 * seen some handwavy posts about posix locking needing to be 139 * done under the BKL, but it's far from clear. 140 */ 141 lock_kernel(); 142 143 if (!nlm_timeout) 144 nlm_timeout = LOCKD_DFLT_TIMEO; 145 nlmsvc_timeout = nlm_timeout * HZ; 146 147 set_grace_period(); 148 149 /* 150 * The main request loop. We don't terminate until the last 151 * NFS mount or NFS daemon has gone away. 152 */ 153 while (!kthread_should_stop()) { 154 long timeout = MAX_SCHEDULE_TIMEOUT; 155 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 156 157 /* update sv_maxconn if it has changed */ 158 rqstp->rq_server->sv_maxconn = nlm_max_connections; 159 160 if (signalled()) { 161 flush_signals(current); 162 restart_grace(); 163 continue; 164 } 165 166 timeout = nlmsvc_retry_blocked(); 167 168 /* 169 * Find a socket with data available and call its 170 * recvfrom routine. 171 */ 172 err = svc_recv(rqstp, timeout); 173 if (err == -EAGAIN || err == -EINTR) { 174 preverr = err; 175 continue; 176 } 177 if (err < 0) { 178 if (err != preverr) { 179 printk(KERN_WARNING "%s: unexpected error " 180 "from svc_recv (%d)\n", __func__, err); 181 preverr = err; 182 } 183 schedule_timeout_interruptible(HZ); 184 continue; 185 } 186 preverr = err; 187 188 dprintk("lockd: request from %s\n", 189 svc_print_addr(rqstp, buf, sizeof(buf))); 190 191 svc_process(rqstp); 192 } 193 flush_signals(current); 194 cancel_delayed_work_sync(&grace_period_end); 195 locks_end_grace(&lockd_manager); 196 if (nlmsvc_ops) 197 nlmsvc_invalidate_all(); 198 nlm_shutdown_hosts(); 199 unlock_kernel(); 200 return 0; 201 } 202 203 static int create_lockd_listener(struct svc_serv *serv, const char *name, 204 const int family, const unsigned short port) 205 { 206 struct svc_xprt *xprt; 207 208 xprt = svc_find_xprt(serv, name, family, 0); 209 if (xprt == NULL) 210 return svc_create_xprt(serv, name, family, port, 211 SVC_SOCK_DEFAULTS); 212 svc_xprt_put(xprt); 213 return 0; 214 } 215 216 static int create_lockd_family(struct svc_serv *serv, const int family) 217 { 218 int err; 219 220 err = create_lockd_listener(serv, "udp", family, nlm_udpport); 221 if (err < 0) 222 return err; 223 224 return create_lockd_listener(serv, "tcp", family, nlm_tcpport); 225 } 226 227 /* 228 * Ensure there are active UDP and TCP listeners for lockd. 229 * 230 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 231 * local services (such as rpc.statd) still require UDP, and 232 * some NFS servers do not yet support NLM over TCP. 233 * 234 * Returns zero if all listeners are available; otherwise a 235 * negative errno value is returned. 236 */ 237 static int make_socks(struct svc_serv *serv) 238 { 239 static int warned; 240 int err; 241 242 err = create_lockd_family(serv, PF_INET); 243 if (err < 0) 244 goto out_err; 245 246 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 247 err = create_lockd_family(serv, PF_INET6); 248 if (err < 0 && err != -EAFNOSUPPORT) 249 goto out_err; 250 #endif /* CONFIG_IPV6 || CONFIG_IPV6_MODULE */ 251 252 warned = 0; 253 return 0; 254 255 out_err: 256 if (warned++ == 0) 257 printk(KERN_WARNING 258 "lockd_up: makesock failed, error=%d\n", err); 259 return err; 260 } 261 262 /* 263 * Bring up the lockd process if it's not already up. 264 */ 265 int lockd_up(void) 266 { 267 struct svc_serv *serv; 268 int error = 0; 269 270 mutex_lock(&nlmsvc_mutex); 271 /* 272 * Check whether we're already up and running. 273 */ 274 if (nlmsvc_rqst) 275 goto out; 276 277 /* 278 * Sanity check: if there's no pid, 279 * we should be the first user ... 280 */ 281 if (nlmsvc_users) 282 printk(KERN_WARNING 283 "lockd_up: no pid, %d users??\n", nlmsvc_users); 284 285 error = -ENOMEM; 286 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 287 if (!serv) { 288 printk(KERN_WARNING "lockd_up: create service failed\n"); 289 goto out; 290 } 291 292 error = make_socks(serv); 293 if (error < 0) 294 goto destroy_and_out; 295 296 /* 297 * Create the kernel thread and wait for it to start. 298 */ 299 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); 300 if (IS_ERR(nlmsvc_rqst)) { 301 error = PTR_ERR(nlmsvc_rqst); 302 nlmsvc_rqst = NULL; 303 printk(KERN_WARNING 304 "lockd_up: svc_rqst allocation failed, error=%d\n", 305 error); 306 goto destroy_and_out; 307 } 308 309 svc_sock_update_bufs(serv); 310 serv->sv_maxconn = nlm_max_connections; 311 312 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 313 if (IS_ERR(nlmsvc_task)) { 314 error = PTR_ERR(nlmsvc_task); 315 svc_exit_thread(nlmsvc_rqst); 316 nlmsvc_task = NULL; 317 nlmsvc_rqst = NULL; 318 printk(KERN_WARNING 319 "lockd_up: kthread_run failed, error=%d\n", error); 320 goto destroy_and_out; 321 } 322 323 /* 324 * Note: svc_serv structures have an initial use count of 1, 325 * so we exit through here on both success and failure. 326 */ 327 destroy_and_out: 328 svc_destroy(serv); 329 out: 330 if (!error) 331 nlmsvc_users++; 332 mutex_unlock(&nlmsvc_mutex); 333 return error; 334 } 335 EXPORT_SYMBOL_GPL(lockd_up); 336 337 /* 338 * Decrement the user count and bring down lockd if we're the last. 339 */ 340 void 341 lockd_down(void) 342 { 343 mutex_lock(&nlmsvc_mutex); 344 if (nlmsvc_users) { 345 if (--nlmsvc_users) 346 goto out; 347 } else { 348 printk(KERN_ERR "lockd_down: no users! task=%p\n", 349 nlmsvc_task); 350 BUG(); 351 } 352 353 if (!nlmsvc_task) { 354 printk(KERN_ERR "lockd_down: no lockd running.\n"); 355 BUG(); 356 } 357 kthread_stop(nlmsvc_task); 358 svc_exit_thread(nlmsvc_rqst); 359 nlmsvc_task = NULL; 360 nlmsvc_rqst = NULL; 361 out: 362 mutex_unlock(&nlmsvc_mutex); 363 } 364 EXPORT_SYMBOL_GPL(lockd_down); 365 366 #ifdef CONFIG_SYSCTL 367 368 /* 369 * Sysctl parameters (same as module parameters, different interface). 370 */ 371 372 static ctl_table nlm_sysctls[] = { 373 { 374 .procname = "nlm_grace_period", 375 .data = &nlm_grace_period, 376 .maxlen = sizeof(unsigned long), 377 .mode = 0644, 378 .proc_handler = proc_doulongvec_minmax, 379 .extra1 = (unsigned long *) &nlm_grace_period_min, 380 .extra2 = (unsigned long *) &nlm_grace_period_max, 381 }, 382 { 383 .procname = "nlm_timeout", 384 .data = &nlm_timeout, 385 .maxlen = sizeof(unsigned long), 386 .mode = 0644, 387 .proc_handler = proc_doulongvec_minmax, 388 .extra1 = (unsigned long *) &nlm_timeout_min, 389 .extra2 = (unsigned long *) &nlm_timeout_max, 390 }, 391 { 392 .procname = "nlm_udpport", 393 .data = &nlm_udpport, 394 .maxlen = sizeof(int), 395 .mode = 0644, 396 .proc_handler = proc_dointvec_minmax, 397 .extra1 = (int *) &nlm_port_min, 398 .extra2 = (int *) &nlm_port_max, 399 }, 400 { 401 .procname = "nlm_tcpport", 402 .data = &nlm_tcpport, 403 .maxlen = sizeof(int), 404 .mode = 0644, 405 .proc_handler = proc_dointvec_minmax, 406 .extra1 = (int *) &nlm_port_min, 407 .extra2 = (int *) &nlm_port_max, 408 }, 409 { 410 .procname = "nsm_use_hostnames", 411 .data = &nsm_use_hostnames, 412 .maxlen = sizeof(int), 413 .mode = 0644, 414 .proc_handler = proc_dointvec, 415 }, 416 { 417 .procname = "nsm_local_state", 418 .data = &nsm_local_state, 419 .maxlen = sizeof(int), 420 .mode = 0644, 421 .proc_handler = proc_dointvec, 422 }, 423 { } 424 }; 425 426 static ctl_table nlm_sysctl_dir[] = { 427 { 428 .procname = "nfs", 429 .mode = 0555, 430 .child = nlm_sysctls, 431 }, 432 { } 433 }; 434 435 static ctl_table nlm_sysctl_root[] = { 436 { 437 .procname = "fs", 438 .mode = 0555, 439 .child = nlm_sysctl_dir, 440 }, 441 { } 442 }; 443 444 #endif /* CONFIG_SYSCTL */ 445 446 /* 447 * Module (and sysfs) parameters. 448 */ 449 450 #define param_set_min_max(name, type, which_strtol, min, max) \ 451 static int param_set_##name(const char *val, struct kernel_param *kp) \ 452 { \ 453 char *endp; \ 454 __typeof__(type) num = which_strtol(val, &endp, 0); \ 455 if (endp == val || *endp || num < (min) || num > (max)) \ 456 return -EINVAL; \ 457 *((int *) kp->arg) = num; \ 458 return 0; \ 459 } 460 461 static inline int is_callback(u32 proc) 462 { 463 return proc == NLMPROC_GRANTED 464 || proc == NLMPROC_GRANTED_MSG 465 || proc == NLMPROC_TEST_RES 466 || proc == NLMPROC_LOCK_RES 467 || proc == NLMPROC_CANCEL_RES 468 || proc == NLMPROC_UNLOCK_RES 469 || proc == NLMPROC_NSM_NOTIFY; 470 } 471 472 473 static int lockd_authenticate(struct svc_rqst *rqstp) 474 { 475 rqstp->rq_client = NULL; 476 switch (rqstp->rq_authop->flavour) { 477 case RPC_AUTH_NULL: 478 case RPC_AUTH_UNIX: 479 if (rqstp->rq_proc == 0) 480 return SVC_OK; 481 if (is_callback(rqstp->rq_proc)) { 482 /* Leave it to individual procedures to 483 * call nlmsvc_lookup_host(rqstp) 484 */ 485 return SVC_OK; 486 } 487 return svc_set_client(rqstp); 488 } 489 return SVC_DENIED; 490 } 491 492 493 param_set_min_max(port, int, simple_strtol, 0, 65535) 494 param_set_min_max(grace_period, unsigned long, simple_strtoul, 495 nlm_grace_period_min, nlm_grace_period_max) 496 param_set_min_max(timeout, unsigned long, simple_strtoul, 497 nlm_timeout_min, nlm_timeout_max) 498 499 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 500 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 501 MODULE_LICENSE("GPL"); 502 503 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 504 &nlm_grace_period, 0644); 505 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 506 &nlm_timeout, 0644); 507 module_param_call(nlm_udpport, param_set_port, param_get_int, 508 &nlm_udpport, 0644); 509 module_param_call(nlm_tcpport, param_set_port, param_get_int, 510 &nlm_tcpport, 0644); 511 module_param(nsm_use_hostnames, bool, 0644); 512 module_param(nlm_max_connections, uint, 0644); 513 514 /* 515 * Initialising and terminating the module. 516 */ 517 518 static int __init init_nlm(void) 519 { 520 #ifdef CONFIG_SYSCTL 521 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 522 return nlm_sysctl_table ? 0 : -ENOMEM; 523 #else 524 return 0; 525 #endif 526 } 527 528 static void __exit exit_nlm(void) 529 { 530 /* FIXME: delete all NLM clients */ 531 nlm_shutdown_hosts(); 532 #ifdef CONFIG_SYSCTL 533 unregister_sysctl_table(nlm_sysctl_table); 534 #endif 535 } 536 537 module_init(init_nlm); 538 module_exit(exit_nlm); 539 540 /* 541 * Define NLM program and procedures 542 */ 543 static struct svc_version nlmsvc_version1 = { 544 .vs_vers = 1, 545 .vs_nproc = 17, 546 .vs_proc = nlmsvc_procedures, 547 .vs_xdrsize = NLMSVC_XDRSIZE, 548 }; 549 static struct svc_version nlmsvc_version3 = { 550 .vs_vers = 3, 551 .vs_nproc = 24, 552 .vs_proc = nlmsvc_procedures, 553 .vs_xdrsize = NLMSVC_XDRSIZE, 554 }; 555 #ifdef CONFIG_LOCKD_V4 556 static struct svc_version nlmsvc_version4 = { 557 .vs_vers = 4, 558 .vs_nproc = 24, 559 .vs_proc = nlmsvc_procedures4, 560 .vs_xdrsize = NLMSVC_XDRSIZE, 561 }; 562 #endif 563 static struct svc_version * nlmsvc_version[] = { 564 [1] = &nlmsvc_version1, 565 [3] = &nlmsvc_version3, 566 #ifdef CONFIG_LOCKD_V4 567 [4] = &nlmsvc_version4, 568 #endif 569 }; 570 571 static struct svc_stat nlmsvc_stats; 572 573 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 574 static struct svc_program nlmsvc_program = { 575 .pg_prog = NLM_PROGRAM, /* program number */ 576 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 577 .pg_vers = nlmsvc_version, /* version table */ 578 .pg_name = "lockd", /* service name */ 579 .pg_class = "nfsd", /* share authentication with nfsd */ 580 .pg_stats = &nlmsvc_stats, /* stats table */ 581 .pg_authenticate = &lockd_authenticate /* export authentication */ 582 }; 583