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/smp_lock.h> 26 #include <linux/mutex.h> 27 #include <linux/kthread.h> 28 #include <linux/freezer.h> 29 30 #include <linux/sunrpc/types.h> 31 #include <linux/sunrpc/stats.h> 32 #include <linux/sunrpc/clnt.h> 33 #include <linux/sunrpc/svc.h> 34 #include <linux/sunrpc/svcsock.h> 35 #include <net/ip.h> 36 #include <linux/lockd/lockd.h> 37 #include <linux/nfs.h> 38 39 #define NLMDBG_FACILITY NLMDBG_SVC 40 #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) 41 #define ALLOWED_SIGS (sigmask(SIGKILL)) 42 43 static struct svc_program nlmsvc_program; 44 45 struct nlmsvc_binding * nlmsvc_ops; 46 EXPORT_SYMBOL_GPL(nlmsvc_ops); 47 48 static DEFINE_MUTEX(nlmsvc_mutex); 49 static unsigned int nlmsvc_users; 50 static struct task_struct *nlmsvc_task; 51 static struct svc_rqst *nlmsvc_rqst; 52 unsigned long nlmsvc_timeout; 53 54 /* 55 * These can be set at insmod time (useful for NFS as root filesystem), 56 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 57 */ 58 static unsigned long nlm_grace_period; 59 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 60 static int nlm_udpport, nlm_tcpport; 61 62 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ 63 static unsigned int nlm_max_connections = 1024; 64 65 /* 66 * Constants needed for the sysctl interface. 67 */ 68 static const unsigned long nlm_grace_period_min = 0; 69 static const unsigned long nlm_grace_period_max = 240; 70 static const unsigned long nlm_timeout_min = 3; 71 static const unsigned long nlm_timeout_max = 20; 72 static const int nlm_port_min = 0, nlm_port_max = 65535; 73 74 #ifdef CONFIG_SYSCTL 75 static struct ctl_table_header * nlm_sysctl_table; 76 #endif 77 78 static unsigned long get_lockd_grace_period(void) 79 { 80 /* Note: nlm_timeout should always be nonzero */ 81 if (nlm_grace_period) 82 return roundup(nlm_grace_period, nlm_timeout) * HZ; 83 else 84 return nlm_timeout * 5 * HZ; 85 } 86 87 static struct lock_manager lockd_manager = { 88 }; 89 90 static void grace_ender(struct work_struct *not_used) 91 { 92 locks_end_grace(&lockd_manager); 93 } 94 95 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); 96 97 static void set_grace_period(void) 98 { 99 unsigned long grace_period = get_lockd_grace_period(); 100 101 locks_start_grace(&lockd_manager); 102 cancel_delayed_work_sync(&grace_period_end); 103 schedule_delayed_work(&grace_period_end, grace_period); 104 } 105 106 static void restart_grace(void) 107 { 108 if (nlmsvc_ops) { 109 cancel_delayed_work_sync(&grace_period_end); 110 locks_end_grace(&lockd_manager); 111 nlmsvc_invalidate_all(); 112 set_grace_period(); 113 } 114 } 115 116 /* 117 * This is the lockd kernel thread 118 */ 119 static int 120 lockd(void *vrqstp) 121 { 122 int err = 0, preverr = 0; 123 struct svc_rqst *rqstp = vrqstp; 124 125 /* try_to_freeze() is called from svc_recv() */ 126 set_freezable(); 127 128 /* Allow SIGKILL to tell lockd to drop all of its locks */ 129 allow_signal(SIGKILL); 130 131 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 132 133 /* 134 * FIXME: it would be nice if lockd didn't spend its entire life 135 * running under the BKL. At the very least, it would be good to 136 * have someone clarify what it's intended to protect here. I've 137 * seen some handwavy posts about posix locking needing to be 138 * done under the BKL, but it's far from clear. 139 */ 140 lock_kernel(); 141 142 if (!nlm_timeout) 143 nlm_timeout = LOCKD_DFLT_TIMEO; 144 nlmsvc_timeout = nlm_timeout * HZ; 145 146 set_grace_period(); 147 148 /* 149 * The main request loop. We don't terminate until the last 150 * NFS mount or NFS daemon has gone away. 151 */ 152 while (!kthread_should_stop()) { 153 long timeout = MAX_SCHEDULE_TIMEOUT; 154 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 155 156 /* update sv_maxconn if it has changed */ 157 rqstp->rq_server->sv_maxconn = nlm_max_connections; 158 159 if (signalled()) { 160 flush_signals(current); 161 restart_grace(); 162 continue; 163 } 164 165 timeout = nlmsvc_retry_blocked(); 166 167 /* 168 * Find a socket with data available and call its 169 * recvfrom routine. 170 */ 171 err = svc_recv(rqstp, timeout); 172 if (err == -EAGAIN || err == -EINTR) { 173 preverr = err; 174 continue; 175 } 176 if (err < 0) { 177 if (err != preverr) { 178 printk(KERN_WARNING "%s: unexpected error " 179 "from svc_recv (%d)\n", __func__, err); 180 preverr = err; 181 } 182 schedule_timeout_interruptible(HZ); 183 continue; 184 } 185 preverr = err; 186 187 dprintk("lockd: request from %s\n", 188 svc_print_addr(rqstp, buf, sizeof(buf))); 189 190 svc_process(rqstp); 191 } 192 flush_signals(current); 193 cancel_delayed_work_sync(&grace_period_end); 194 locks_end_grace(&lockd_manager); 195 if (nlmsvc_ops) 196 nlmsvc_invalidate_all(); 197 nlm_shutdown_hosts(); 198 unlock_kernel(); 199 return 0; 200 } 201 202 static int create_lockd_listener(struct svc_serv *serv, const char *name, 203 const int family, const unsigned short port) 204 { 205 struct svc_xprt *xprt; 206 207 xprt = svc_find_xprt(serv, name, family, 0); 208 if (xprt == NULL) 209 return svc_create_xprt(serv, name, family, port, 210 SVC_SOCK_DEFAULTS); 211 svc_xprt_put(xprt); 212 return 0; 213 } 214 215 static int create_lockd_family(struct svc_serv *serv, const int family) 216 { 217 int err; 218 219 err = create_lockd_listener(serv, "udp", family, nlm_udpport); 220 if (err < 0) 221 return err; 222 223 return create_lockd_listener(serv, "tcp", family, nlm_tcpport); 224 } 225 226 /* 227 * Ensure there are active UDP and TCP listeners for lockd. 228 * 229 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 230 * local services (such as rpc.statd) still require UDP, and 231 * some NFS servers do not yet support NLM over TCP. 232 * 233 * Returns zero if all listeners are available; otherwise a 234 * negative errno value is returned. 235 */ 236 static int make_socks(struct svc_serv *serv) 237 { 238 static int warned; 239 int err; 240 241 err = create_lockd_family(serv, PF_INET); 242 if (err < 0) 243 goto out_err; 244 245 err = create_lockd_family(serv, PF_INET6); 246 if (err < 0 && err != -EAFNOSUPPORT) 247 goto out_err; 248 249 warned = 0; 250 return 0; 251 252 out_err: 253 if (warned++ == 0) 254 printk(KERN_WARNING 255 "lockd_up: makesock failed, error=%d\n", err); 256 return err; 257 } 258 259 /* 260 * Bring up the lockd process if it's not already up. 261 */ 262 int lockd_up(void) 263 { 264 struct svc_serv *serv; 265 int error = 0; 266 267 mutex_lock(&nlmsvc_mutex); 268 /* 269 * Check whether we're already up and running. 270 */ 271 if (nlmsvc_rqst) 272 goto out; 273 274 /* 275 * Sanity check: if there's no pid, 276 * we should be the first user ... 277 */ 278 if (nlmsvc_users) 279 printk(KERN_WARNING 280 "lockd_up: no pid, %d users??\n", nlmsvc_users); 281 282 error = -ENOMEM; 283 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 284 if (!serv) { 285 printk(KERN_WARNING "lockd_up: create service failed\n"); 286 goto out; 287 } 288 289 error = make_socks(serv); 290 if (error < 0) 291 goto destroy_and_out; 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]); 297 if (IS_ERR(nlmsvc_rqst)) { 298 error = PTR_ERR(nlmsvc_rqst); 299 nlmsvc_rqst = NULL; 300 printk(KERN_WARNING 301 "lockd_up: svc_rqst allocation failed, error=%d\n", 302 error); 303 goto destroy_and_out; 304 } 305 306 svc_sock_update_bufs(serv); 307 serv->sv_maxconn = nlm_max_connections; 308 309 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 310 if (IS_ERR(nlmsvc_task)) { 311 error = PTR_ERR(nlmsvc_task); 312 svc_exit_thread(nlmsvc_rqst); 313 nlmsvc_task = NULL; 314 nlmsvc_rqst = NULL; 315 printk(KERN_WARNING 316 "lockd_up: kthread_run failed, error=%d\n", error); 317 goto destroy_and_out; 318 } 319 320 /* 321 * Note: svc_serv structures have an initial use count of 1, 322 * so we exit through here on both success and failure. 323 */ 324 destroy_and_out: 325 svc_destroy(serv); 326 out: 327 if (!error) 328 nlmsvc_users++; 329 mutex_unlock(&nlmsvc_mutex); 330 return error; 331 } 332 EXPORT_SYMBOL_GPL(lockd_up); 333 334 /* 335 * Decrement the user count and bring down lockd if we're the last. 336 */ 337 void 338 lockd_down(void) 339 { 340 mutex_lock(&nlmsvc_mutex); 341 if (nlmsvc_users) { 342 if (--nlmsvc_users) 343 goto out; 344 } else { 345 printk(KERN_ERR "lockd_down: no users! task=%p\n", 346 nlmsvc_task); 347 BUG(); 348 } 349 350 if (!nlmsvc_task) { 351 printk(KERN_ERR "lockd_down: no lockd running.\n"); 352 BUG(); 353 } 354 kthread_stop(nlmsvc_task); 355 svc_exit_thread(nlmsvc_rqst); 356 nlmsvc_task = NULL; 357 nlmsvc_rqst = NULL; 358 out: 359 mutex_unlock(&nlmsvc_mutex); 360 } 361 EXPORT_SYMBOL_GPL(lockd_down); 362 363 #ifdef CONFIG_SYSCTL 364 365 /* 366 * Sysctl parameters (same as module parameters, different interface). 367 */ 368 369 static ctl_table nlm_sysctls[] = { 370 { 371 .procname = "nlm_grace_period", 372 .data = &nlm_grace_period, 373 .maxlen = sizeof(unsigned long), 374 .mode = 0644, 375 .proc_handler = proc_doulongvec_minmax, 376 .extra1 = (unsigned long *) &nlm_grace_period_min, 377 .extra2 = (unsigned long *) &nlm_grace_period_max, 378 }, 379 { 380 .procname = "nlm_timeout", 381 .data = &nlm_timeout, 382 .maxlen = sizeof(unsigned long), 383 .mode = 0644, 384 .proc_handler = proc_doulongvec_minmax, 385 .extra1 = (unsigned long *) &nlm_timeout_min, 386 .extra2 = (unsigned long *) &nlm_timeout_max, 387 }, 388 { 389 .procname = "nlm_udpport", 390 .data = &nlm_udpport, 391 .maxlen = sizeof(int), 392 .mode = 0644, 393 .proc_handler = proc_dointvec_minmax, 394 .extra1 = (int *) &nlm_port_min, 395 .extra2 = (int *) &nlm_port_max, 396 }, 397 { 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 .procname = "nsm_use_hostnames", 408 .data = &nsm_use_hostnames, 409 .maxlen = sizeof(int), 410 .mode = 0644, 411 .proc_handler = proc_dointvec, 412 }, 413 { 414 .procname = "nsm_local_state", 415 .data = &nsm_local_state, 416 .maxlen = sizeof(int), 417 .mode = 0644, 418 .proc_handler = proc_dointvec, 419 }, 420 { } 421 }; 422 423 static ctl_table nlm_sysctl_dir[] = { 424 { 425 .procname = "nfs", 426 .mode = 0555, 427 .child = nlm_sysctls, 428 }, 429 { } 430 }; 431 432 static ctl_table nlm_sysctl_root[] = { 433 { 434 .procname = "fs", 435 .mode = 0555, 436 .child = nlm_sysctl_dir, 437 }, 438 { } 439 }; 440 441 #endif /* CONFIG_SYSCTL */ 442 443 /* 444 * Module (and sysfs) parameters. 445 */ 446 447 #define param_set_min_max(name, type, which_strtol, min, max) \ 448 static int param_set_##name(const char *val, struct kernel_param *kp) \ 449 { \ 450 char *endp; \ 451 __typeof__(type) num = which_strtol(val, &endp, 0); \ 452 if (endp == val || *endp || num < (min) || num > (max)) \ 453 return -EINVAL; \ 454 *((int *) kp->arg) = num; \ 455 return 0; \ 456 } 457 458 static inline int is_callback(u32 proc) 459 { 460 return proc == NLMPROC_GRANTED 461 || proc == NLMPROC_GRANTED_MSG 462 || proc == NLMPROC_TEST_RES 463 || proc == NLMPROC_LOCK_RES 464 || proc == NLMPROC_CANCEL_RES 465 || proc == NLMPROC_UNLOCK_RES 466 || proc == NLMPROC_NSM_NOTIFY; 467 } 468 469 470 static int lockd_authenticate(struct svc_rqst *rqstp) 471 { 472 rqstp->rq_client = NULL; 473 switch (rqstp->rq_authop->flavour) { 474 case RPC_AUTH_NULL: 475 case RPC_AUTH_UNIX: 476 if (rqstp->rq_proc == 0) 477 return SVC_OK; 478 if (is_callback(rqstp->rq_proc)) { 479 /* Leave it to individual procedures to 480 * call nlmsvc_lookup_host(rqstp) 481 */ 482 return SVC_OK; 483 } 484 return svc_set_client(rqstp); 485 } 486 return SVC_DENIED; 487 } 488 489 490 param_set_min_max(port, int, simple_strtol, 0, 65535) 491 param_set_min_max(grace_period, unsigned long, simple_strtoul, 492 nlm_grace_period_min, nlm_grace_period_max) 493 param_set_min_max(timeout, unsigned long, simple_strtoul, 494 nlm_timeout_min, nlm_timeout_max) 495 496 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 497 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 498 MODULE_LICENSE("GPL"); 499 500 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 501 &nlm_grace_period, 0644); 502 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 503 &nlm_timeout, 0644); 504 module_param_call(nlm_udpport, param_set_port, param_get_int, 505 &nlm_udpport, 0644); 506 module_param_call(nlm_tcpport, param_set_port, param_get_int, 507 &nlm_tcpport, 0644); 508 module_param(nsm_use_hostnames, bool, 0644); 509 module_param(nlm_max_connections, uint, 0644); 510 511 /* 512 * Initialising and terminating the module. 513 */ 514 515 static int __init init_nlm(void) 516 { 517 #ifdef CONFIG_SYSCTL 518 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 519 return nlm_sysctl_table ? 0 : -ENOMEM; 520 #else 521 return 0; 522 #endif 523 } 524 525 static void __exit exit_nlm(void) 526 { 527 /* FIXME: delete all NLM clients */ 528 nlm_shutdown_hosts(); 529 #ifdef CONFIG_SYSCTL 530 unregister_sysctl_table(nlm_sysctl_table); 531 #endif 532 } 533 534 module_init(init_nlm); 535 module_exit(exit_nlm); 536 537 /* 538 * Define NLM program and procedures 539 */ 540 static struct svc_version nlmsvc_version1 = { 541 .vs_vers = 1, 542 .vs_nproc = 17, 543 .vs_proc = nlmsvc_procedures, 544 .vs_xdrsize = NLMSVC_XDRSIZE, 545 }; 546 static struct svc_version nlmsvc_version3 = { 547 .vs_vers = 3, 548 .vs_nproc = 24, 549 .vs_proc = nlmsvc_procedures, 550 .vs_xdrsize = NLMSVC_XDRSIZE, 551 }; 552 #ifdef CONFIG_LOCKD_V4 553 static struct svc_version nlmsvc_version4 = { 554 .vs_vers = 4, 555 .vs_nproc = 24, 556 .vs_proc = nlmsvc_procedures4, 557 .vs_xdrsize = NLMSVC_XDRSIZE, 558 }; 559 #endif 560 static struct svc_version * nlmsvc_version[] = { 561 [1] = &nlmsvc_version1, 562 [3] = &nlmsvc_version3, 563 #ifdef CONFIG_LOCKD_V4 564 [4] = &nlmsvc_version4, 565 #endif 566 }; 567 568 static struct svc_stat nlmsvc_stats; 569 570 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 571 static struct svc_program nlmsvc_program = { 572 .pg_prog = NLM_PROGRAM, /* program number */ 573 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 574 .pg_vers = nlmsvc_version, /* version table */ 575 .pg_name = "lockd", /* service name */ 576 .pg_class = "nfsd", /* share authentication with nfsd */ 577 .pg_stats = &nlmsvc_stats, /* stats table */ 578 .pg_authenticate = &lockd_authenticate /* export authentication */ 579 }; 580