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 /* 108 * This is the lockd kernel thread 109 */ 110 static int 111 lockd(void *vrqstp) 112 { 113 int err = 0, preverr = 0; 114 struct svc_rqst *rqstp = vrqstp; 115 116 /* try_to_freeze() is called from svc_recv() */ 117 set_freezable(); 118 119 /* Allow SIGKILL to tell lockd to drop all of its locks */ 120 allow_signal(SIGKILL); 121 122 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 123 124 /* 125 * FIXME: it would be nice if lockd didn't spend its entire life 126 * running under the BKL. At the very least, it would be good to 127 * have someone clarify what it's intended to protect here. I've 128 * seen some handwavy posts about posix locking needing to be 129 * done under the BKL, but it's far from clear. 130 */ 131 lock_kernel(); 132 133 if (!nlm_timeout) 134 nlm_timeout = LOCKD_DFLT_TIMEO; 135 nlmsvc_timeout = nlm_timeout * HZ; 136 137 set_grace_period(); 138 139 /* 140 * The main request loop. We don't terminate until the last 141 * NFS mount or NFS daemon has gone away. 142 */ 143 while (!kthread_should_stop()) { 144 long timeout = MAX_SCHEDULE_TIMEOUT; 145 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 146 147 /* update sv_maxconn if it has changed */ 148 rqstp->rq_server->sv_maxconn = nlm_max_connections; 149 150 if (signalled()) { 151 flush_signals(current); 152 if (nlmsvc_ops) { 153 nlmsvc_invalidate_all(); 154 set_grace_period(); 155 } 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 unlock_kernel(); 193 return 0; 194 } 195 196 static int create_lockd_listener(struct svc_serv *serv, const char *name, 197 const int family, const unsigned short port) 198 { 199 struct svc_xprt *xprt; 200 201 xprt = svc_find_xprt(serv, name, family, 0); 202 if (xprt == NULL) 203 return svc_create_xprt(serv, name, 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, const int family) 210 { 211 int err; 212 213 err = create_lockd_listener(serv, "udp", family, nlm_udpport); 214 if (err < 0) 215 return err; 216 217 return create_lockd_listener(serv, "tcp", family, nlm_tcpport); 218 } 219 220 /* 221 * Ensure there are active UDP and TCP listeners for lockd. 222 * 223 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 224 * local services (such as rpc.statd) still require UDP, and 225 * some NFS servers do not yet support NLM over TCP. 226 * 227 * Returns zero if all listeners are available; otherwise a 228 * negative errno value is returned. 229 */ 230 static int make_socks(struct svc_serv *serv) 231 { 232 static int warned; 233 int err; 234 235 err = create_lockd_family(serv, PF_INET); 236 if (err < 0) 237 goto out_err; 238 239 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 240 err = create_lockd_family(serv, PF_INET6); 241 if (err < 0 && err != -EAFNOSUPPORT) 242 goto out_err; 243 #endif /* CONFIG_IPV6 || CONFIG_IPV6_MODULE */ 244 245 warned = 0; 246 return 0; 247 248 out_err: 249 if (warned++ == 0) 250 printk(KERN_WARNING 251 "lockd_up: makesock failed, error=%d\n", err); 252 return err; 253 } 254 255 /* 256 * Bring up the lockd process if it's not already up. 257 */ 258 int lockd_up(void) 259 { 260 struct svc_serv *serv; 261 int error = 0; 262 263 mutex_lock(&nlmsvc_mutex); 264 /* 265 * Check whether we're already up and running. 266 */ 267 if (nlmsvc_rqst) 268 goto out; 269 270 /* 271 * Sanity check: if there's no pid, 272 * we should be the first user ... 273 */ 274 if (nlmsvc_users) 275 printk(KERN_WARNING 276 "lockd_up: no pid, %d users??\n", nlmsvc_users); 277 278 error = -ENOMEM; 279 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 280 if (!serv) { 281 printk(KERN_WARNING "lockd_up: create service failed\n"); 282 goto out; 283 } 284 285 error = make_socks(serv); 286 if (error < 0) 287 goto destroy_and_out; 288 289 /* 290 * Create the kernel thread and wait for it to start. 291 */ 292 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); 293 if (IS_ERR(nlmsvc_rqst)) { 294 error = PTR_ERR(nlmsvc_rqst); 295 nlmsvc_rqst = NULL; 296 printk(KERN_WARNING 297 "lockd_up: svc_rqst allocation failed, error=%d\n", 298 error); 299 goto destroy_and_out; 300 } 301 302 svc_sock_update_bufs(serv); 303 serv->sv_maxconn = nlm_max_connections; 304 305 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 306 if (IS_ERR(nlmsvc_task)) { 307 error = PTR_ERR(nlmsvc_task); 308 svc_exit_thread(nlmsvc_rqst); 309 nlmsvc_task = NULL; 310 nlmsvc_rqst = NULL; 311 printk(KERN_WARNING 312 "lockd_up: kthread_run failed, error=%d\n", error); 313 goto destroy_and_out; 314 } 315 316 /* 317 * Note: svc_serv structures have an initial use count of 1, 318 * so we exit through here on both success and failure. 319 */ 320 destroy_and_out: 321 svc_destroy(serv); 322 out: 323 if (!error) 324 nlmsvc_users++; 325 mutex_unlock(&nlmsvc_mutex); 326 return error; 327 } 328 EXPORT_SYMBOL_GPL(lockd_up); 329 330 /* 331 * Decrement the user count and bring down lockd if we're the last. 332 */ 333 void 334 lockd_down(void) 335 { 336 mutex_lock(&nlmsvc_mutex); 337 if (nlmsvc_users) { 338 if (--nlmsvc_users) 339 goto out; 340 } else { 341 printk(KERN_ERR "lockd_down: no users! task=%p\n", 342 nlmsvc_task); 343 BUG(); 344 } 345 346 if (!nlmsvc_task) { 347 printk(KERN_ERR "lockd_down: no lockd running.\n"); 348 BUG(); 349 } 350 kthread_stop(nlmsvc_task); 351 svc_exit_thread(nlmsvc_rqst); 352 nlmsvc_task = NULL; 353 nlmsvc_rqst = NULL; 354 out: 355 mutex_unlock(&nlmsvc_mutex); 356 } 357 EXPORT_SYMBOL_GPL(lockd_down); 358 359 #ifdef CONFIG_SYSCTL 360 361 /* 362 * Sysctl parameters (same as module parameters, different interface). 363 */ 364 365 static ctl_table nlm_sysctls[] = { 366 { 367 .ctl_name = CTL_UNNUMBERED, 368 .procname = "nlm_grace_period", 369 .data = &nlm_grace_period, 370 .maxlen = sizeof(unsigned long), 371 .mode = 0644, 372 .proc_handler = &proc_doulongvec_minmax, 373 .extra1 = (unsigned long *) &nlm_grace_period_min, 374 .extra2 = (unsigned long *) &nlm_grace_period_max, 375 }, 376 { 377 .ctl_name = CTL_UNNUMBERED, 378 .procname = "nlm_timeout", 379 .data = &nlm_timeout, 380 .maxlen = sizeof(unsigned long), 381 .mode = 0644, 382 .proc_handler = &proc_doulongvec_minmax, 383 .extra1 = (unsigned long *) &nlm_timeout_min, 384 .extra2 = (unsigned long *) &nlm_timeout_max, 385 }, 386 { 387 .ctl_name = CTL_UNNUMBERED, 388 .procname = "nlm_udpport", 389 .data = &nlm_udpport, 390 .maxlen = sizeof(int), 391 .mode = 0644, 392 .proc_handler = &proc_dointvec_minmax, 393 .extra1 = (int *) &nlm_port_min, 394 .extra2 = (int *) &nlm_port_max, 395 }, 396 { 397 .ctl_name = CTL_UNNUMBERED, 398 .procname = "nlm_tcpport", 399 .data = &nlm_tcpport, 400 .maxlen = sizeof(int), 401 .mode = 0644, 402 .proc_handler = &proc_dointvec_minmax, 403 .extra1 = (int *) &nlm_port_min, 404 .extra2 = (int *) &nlm_port_max, 405 }, 406 { 407 .ctl_name = CTL_UNNUMBERED, 408 .procname = "nsm_use_hostnames", 409 .data = &nsm_use_hostnames, 410 .maxlen = sizeof(int), 411 .mode = 0644, 412 .proc_handler = &proc_dointvec, 413 }, 414 { 415 .ctl_name = CTL_UNNUMBERED, 416 .procname = "nsm_local_state", 417 .data = &nsm_local_state, 418 .maxlen = sizeof(int), 419 .mode = 0644, 420 .proc_handler = &proc_dointvec, 421 }, 422 { .ctl_name = 0 } 423 }; 424 425 static ctl_table nlm_sysctl_dir[] = { 426 { 427 .ctl_name = CTL_UNNUMBERED, 428 .procname = "nfs", 429 .mode = 0555, 430 .child = nlm_sysctls, 431 }, 432 { .ctl_name = 0 } 433 }; 434 435 static ctl_table nlm_sysctl_root[] = { 436 { 437 .ctl_name = CTL_FS, 438 .procname = "fs", 439 .mode = 0555, 440 .child = nlm_sysctl_dir, 441 }, 442 { .ctl_name = 0 } 443 }; 444 445 #endif /* CONFIG_SYSCTL */ 446 447 /* 448 * Module (and sysfs) parameters. 449 */ 450 451 #define param_set_min_max(name, type, which_strtol, min, max) \ 452 static int param_set_##name(const char *val, struct kernel_param *kp) \ 453 { \ 454 char *endp; \ 455 __typeof__(type) num = which_strtol(val, &endp, 0); \ 456 if (endp == val || *endp || num < (min) || num > (max)) \ 457 return -EINVAL; \ 458 *((int *) kp->arg) = num; \ 459 return 0; \ 460 } 461 462 static inline int is_callback(u32 proc) 463 { 464 return proc == NLMPROC_GRANTED 465 || proc == NLMPROC_GRANTED_MSG 466 || proc == NLMPROC_TEST_RES 467 || proc == NLMPROC_LOCK_RES 468 || proc == NLMPROC_CANCEL_RES 469 || proc == NLMPROC_UNLOCK_RES 470 || proc == NLMPROC_NSM_NOTIFY; 471 } 472 473 474 static int lockd_authenticate(struct svc_rqst *rqstp) 475 { 476 rqstp->rq_client = NULL; 477 switch (rqstp->rq_authop->flavour) { 478 case RPC_AUTH_NULL: 479 case RPC_AUTH_UNIX: 480 if (rqstp->rq_proc == 0) 481 return SVC_OK; 482 if (is_callback(rqstp->rq_proc)) { 483 /* Leave it to individual procedures to 484 * call nlmsvc_lookup_host(rqstp) 485 */ 486 return SVC_OK; 487 } 488 return svc_set_client(rqstp); 489 } 490 return SVC_DENIED; 491 } 492 493 494 param_set_min_max(port, int, simple_strtol, 0, 65535) 495 param_set_min_max(grace_period, unsigned long, simple_strtoul, 496 nlm_grace_period_min, nlm_grace_period_max) 497 param_set_min_max(timeout, unsigned long, simple_strtoul, 498 nlm_timeout_min, nlm_timeout_max) 499 500 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 501 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 502 MODULE_LICENSE("GPL"); 503 504 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 505 &nlm_grace_period, 0644); 506 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 507 &nlm_timeout, 0644); 508 module_param_call(nlm_udpport, param_set_port, param_get_int, 509 &nlm_udpport, 0644); 510 module_param_call(nlm_tcpport, param_set_port, param_get_int, 511 &nlm_tcpport, 0644); 512 module_param(nsm_use_hostnames, bool, 0644); 513 module_param(nlm_max_connections, uint, 0644); 514 515 /* 516 * Initialising and terminating the module. 517 */ 518 519 static int __init init_nlm(void) 520 { 521 #ifdef CONFIG_SYSCTL 522 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 523 return nlm_sysctl_table ? 0 : -ENOMEM; 524 #else 525 return 0; 526 #endif 527 } 528 529 static void __exit exit_nlm(void) 530 { 531 /* FIXME: delete all NLM clients */ 532 nlm_shutdown_hosts(); 533 #ifdef CONFIG_SYSCTL 534 unregister_sysctl_table(nlm_sysctl_table); 535 #endif 536 } 537 538 module_init(init_nlm); 539 module_exit(exit_nlm); 540 541 /* 542 * Define NLM program and procedures 543 */ 544 static struct svc_version nlmsvc_version1 = { 545 .vs_vers = 1, 546 .vs_nproc = 17, 547 .vs_proc = nlmsvc_procedures, 548 .vs_xdrsize = NLMSVC_XDRSIZE, 549 }; 550 static struct svc_version nlmsvc_version3 = { 551 .vs_vers = 3, 552 .vs_nproc = 24, 553 .vs_proc = nlmsvc_procedures, 554 .vs_xdrsize = NLMSVC_XDRSIZE, 555 }; 556 #ifdef CONFIG_LOCKD_V4 557 static struct svc_version nlmsvc_version4 = { 558 .vs_vers = 4, 559 .vs_nproc = 24, 560 .vs_proc = nlmsvc_procedures4, 561 .vs_xdrsize = NLMSVC_XDRSIZE, 562 }; 563 #endif 564 static struct svc_version * nlmsvc_version[] = { 565 [1] = &nlmsvc_version1, 566 [3] = &nlmsvc_version3, 567 #ifdef CONFIG_LOCKD_V4 568 [4] = &nlmsvc_version4, 569 #endif 570 }; 571 572 static struct svc_stat nlmsvc_stats; 573 574 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 575 static struct svc_program nlmsvc_program = { 576 .pg_prog = NLM_PROGRAM, /* program number */ 577 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 578 .pg_vers = nlmsvc_version, /* version table */ 579 .pg_name = "lockd", /* service name */ 580 .pg_class = "nfsd", /* share authentication with nfsd */ 581 .pg_stats = &nlmsvc_stats, /* stats table */ 582 .pg_authenticate = &lockd_authenticate /* export authentication */ 583 }; 584