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 * If the kernel has IPv6 support available, always listen for 57 * both AF_INET and AF_INET6 requests. 58 */ 59 #if (defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)) && \ 60 defined(CONFIG_SUNRPC_REGISTER_V4) 61 static const sa_family_t nlmsvc_family = AF_INET6; 62 #else /* (CONFIG_IPV6 || CONFIG_IPV6_MODULE) && CONFIG_SUNRPC_REGISTER_V4 */ 63 static const sa_family_t nlmsvc_family = AF_INET; 64 #endif /* (CONFIG_IPV6 || CONFIG_IPV6_MODULE) && CONFIG_SUNRPC_REGISTER_V4 */ 65 66 /* 67 * These can be set at insmod time (useful for NFS as root filesystem), 68 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 69 */ 70 static unsigned long nlm_grace_period; 71 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 72 static int nlm_udpport, nlm_tcpport; 73 74 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ 75 static unsigned int nlm_max_connections = 1024; 76 77 /* 78 * Constants needed for the sysctl interface. 79 */ 80 static const unsigned long nlm_grace_period_min = 0; 81 static const unsigned long nlm_grace_period_max = 240; 82 static const unsigned long nlm_timeout_min = 3; 83 static const unsigned long nlm_timeout_max = 20; 84 static const int nlm_port_min = 0, nlm_port_max = 65535; 85 86 #ifdef CONFIG_SYSCTL 87 static struct ctl_table_header * nlm_sysctl_table; 88 #endif 89 90 static unsigned long get_lockd_grace_period(void) 91 { 92 /* Note: nlm_timeout should always be nonzero */ 93 if (nlm_grace_period) 94 return roundup(nlm_grace_period, nlm_timeout) * HZ; 95 else 96 return nlm_timeout * 5 * HZ; 97 } 98 99 static struct lock_manager lockd_manager = { 100 }; 101 102 static void grace_ender(struct work_struct *not_used) 103 { 104 locks_end_grace(&lockd_manager); 105 } 106 107 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); 108 109 static void set_grace_period(void) 110 { 111 unsigned long grace_period = get_lockd_grace_period(); 112 113 locks_start_grace(&lockd_manager); 114 cancel_delayed_work_sync(&grace_period_end); 115 schedule_delayed_work(&grace_period_end, grace_period); 116 } 117 118 /* 119 * This is the lockd kernel thread 120 */ 121 static int 122 lockd(void *vrqstp) 123 { 124 int err = 0, preverr = 0; 125 struct svc_rqst *rqstp = vrqstp; 126 127 /* try_to_freeze() is called from svc_recv() */ 128 set_freezable(); 129 130 /* Allow SIGKILL to tell lockd to drop all of its locks */ 131 allow_signal(SIGKILL); 132 133 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 134 135 /* 136 * FIXME: it would be nice if lockd didn't spend its entire life 137 * running under the BKL. At the very least, it would be good to 138 * have someone clarify what it's intended to protect here. I've 139 * seen some handwavy posts about posix locking needing to be 140 * done under the BKL, but it's far from clear. 141 */ 142 lock_kernel(); 143 144 if (!nlm_timeout) 145 nlm_timeout = LOCKD_DFLT_TIMEO; 146 nlmsvc_timeout = nlm_timeout * HZ; 147 148 set_grace_period(); 149 150 /* 151 * The main request loop. We don't terminate until the last 152 * NFS mount or NFS daemon has gone away. 153 */ 154 while (!kthread_should_stop()) { 155 long timeout = MAX_SCHEDULE_TIMEOUT; 156 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 157 158 /* update sv_maxconn if it has changed */ 159 rqstp->rq_server->sv_maxconn = nlm_max_connections; 160 161 if (signalled()) { 162 flush_signals(current); 163 if (nlmsvc_ops) { 164 nlmsvc_invalidate_all(); 165 set_grace_period(); 166 } 167 continue; 168 } 169 170 timeout = nlmsvc_retry_blocked(); 171 172 /* 173 * Find a socket with data available and call its 174 * recvfrom routine. 175 */ 176 err = svc_recv(rqstp, timeout); 177 if (err == -EAGAIN || err == -EINTR) { 178 preverr = err; 179 continue; 180 } 181 if (err < 0) { 182 if (err != preverr) { 183 printk(KERN_WARNING "%s: unexpected error " 184 "from svc_recv (%d)\n", __func__, err); 185 preverr = err; 186 } 187 schedule_timeout_interruptible(HZ); 188 continue; 189 } 190 preverr = err; 191 192 dprintk("lockd: request from %s\n", 193 svc_print_addr(rqstp, buf, sizeof(buf))); 194 195 svc_process(rqstp); 196 } 197 flush_signals(current); 198 cancel_delayed_work_sync(&grace_period_end); 199 locks_end_grace(&lockd_manager); 200 if (nlmsvc_ops) 201 nlmsvc_invalidate_all(); 202 nlm_shutdown_hosts(); 203 unlock_kernel(); 204 return 0; 205 } 206 207 static int create_lockd_listener(struct svc_serv *serv, char *name, 208 unsigned short port) 209 { 210 struct svc_xprt *xprt; 211 212 xprt = svc_find_xprt(serv, name, 0, 0); 213 if (xprt == NULL) 214 return svc_create_xprt(serv, name, port, SVC_SOCK_DEFAULTS); 215 216 svc_xprt_put(xprt); 217 return 0; 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_listener(serv, "udp", nlm_udpport); 236 if (err < 0) 237 goto out_err; 238 239 err = create_lockd_listener(serv, "tcp", nlm_tcpport); 240 if (err < 0) 241 goto out_err; 242 243 warned = 0; 244 return 0; 245 246 out_err: 247 if (warned++ == 0) 248 printk(KERN_WARNING 249 "lockd_up: makesock failed, error=%d\n", err); 250 return err; 251 } 252 253 /* 254 * Bring up the lockd process if it's not already up. 255 */ 256 int lockd_up(void) 257 { 258 struct svc_serv *serv; 259 int error = 0; 260 261 mutex_lock(&nlmsvc_mutex); 262 /* 263 * Check whether we're already up and running. 264 */ 265 if (nlmsvc_rqst) 266 goto out; 267 268 /* 269 * Sanity check: if there's no pid, 270 * we should be the first user ... 271 */ 272 if (nlmsvc_users) 273 printk(KERN_WARNING 274 "lockd_up: no pid, %d users??\n", nlmsvc_users); 275 276 error = -ENOMEM; 277 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, nlmsvc_family, NULL); 278 if (!serv) { 279 printk(KERN_WARNING "lockd_up: create service failed\n"); 280 goto out; 281 } 282 283 error = make_socks(serv); 284 if (error < 0) 285 goto destroy_and_out; 286 287 /* 288 * Create the kernel thread and wait for it to start. 289 */ 290 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); 291 if (IS_ERR(nlmsvc_rqst)) { 292 error = PTR_ERR(nlmsvc_rqst); 293 nlmsvc_rqst = NULL; 294 printk(KERN_WARNING 295 "lockd_up: svc_rqst allocation failed, error=%d\n", 296 error); 297 goto destroy_and_out; 298 } 299 300 svc_sock_update_bufs(serv); 301 serv->sv_maxconn = nlm_max_connections; 302 303 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 304 if (IS_ERR(nlmsvc_task)) { 305 error = PTR_ERR(nlmsvc_task); 306 svc_exit_thread(nlmsvc_rqst); 307 nlmsvc_task = NULL; 308 nlmsvc_rqst = NULL; 309 printk(KERN_WARNING 310 "lockd_up: kthread_run failed, error=%d\n", error); 311 goto destroy_and_out; 312 } 313 314 /* 315 * Note: svc_serv structures have an initial use count of 1, 316 * so we exit through here on both success and failure. 317 */ 318 destroy_and_out: 319 svc_destroy(serv); 320 out: 321 if (!error) 322 nlmsvc_users++; 323 mutex_unlock(&nlmsvc_mutex); 324 return error; 325 } 326 EXPORT_SYMBOL_GPL(lockd_up); 327 328 /* 329 * Decrement the user count and bring down lockd if we're the last. 330 */ 331 void 332 lockd_down(void) 333 { 334 mutex_lock(&nlmsvc_mutex); 335 if (nlmsvc_users) { 336 if (--nlmsvc_users) 337 goto out; 338 } else { 339 printk(KERN_ERR "lockd_down: no users! task=%p\n", 340 nlmsvc_task); 341 BUG(); 342 } 343 344 if (!nlmsvc_task) { 345 printk(KERN_ERR "lockd_down: no lockd running.\n"); 346 BUG(); 347 } 348 kthread_stop(nlmsvc_task); 349 svc_exit_thread(nlmsvc_rqst); 350 nlmsvc_task = NULL; 351 nlmsvc_rqst = NULL; 352 out: 353 mutex_unlock(&nlmsvc_mutex); 354 } 355 EXPORT_SYMBOL_GPL(lockd_down); 356 357 #ifdef CONFIG_SYSCTL 358 359 /* 360 * Sysctl parameters (same as module parameters, different interface). 361 */ 362 363 static ctl_table nlm_sysctls[] = { 364 { 365 .ctl_name = CTL_UNNUMBERED, 366 .procname = "nlm_grace_period", 367 .data = &nlm_grace_period, 368 .maxlen = sizeof(unsigned long), 369 .mode = 0644, 370 .proc_handler = &proc_doulongvec_minmax, 371 .extra1 = (unsigned long *) &nlm_grace_period_min, 372 .extra2 = (unsigned long *) &nlm_grace_period_max, 373 }, 374 { 375 .ctl_name = CTL_UNNUMBERED, 376 .procname = "nlm_timeout", 377 .data = &nlm_timeout, 378 .maxlen = sizeof(unsigned long), 379 .mode = 0644, 380 .proc_handler = &proc_doulongvec_minmax, 381 .extra1 = (unsigned long *) &nlm_timeout_min, 382 .extra2 = (unsigned long *) &nlm_timeout_max, 383 }, 384 { 385 .ctl_name = CTL_UNNUMBERED, 386 .procname = "nlm_udpport", 387 .data = &nlm_udpport, 388 .maxlen = sizeof(int), 389 .mode = 0644, 390 .proc_handler = &proc_dointvec_minmax, 391 .extra1 = (int *) &nlm_port_min, 392 .extra2 = (int *) &nlm_port_max, 393 }, 394 { 395 .ctl_name = CTL_UNNUMBERED, 396 .procname = "nlm_tcpport", 397 .data = &nlm_tcpport, 398 .maxlen = sizeof(int), 399 .mode = 0644, 400 .proc_handler = &proc_dointvec_minmax, 401 .extra1 = (int *) &nlm_port_min, 402 .extra2 = (int *) &nlm_port_max, 403 }, 404 { 405 .ctl_name = CTL_UNNUMBERED, 406 .procname = "nsm_use_hostnames", 407 .data = &nsm_use_hostnames, 408 .maxlen = sizeof(int), 409 .mode = 0644, 410 .proc_handler = &proc_dointvec, 411 }, 412 { 413 .ctl_name = CTL_UNNUMBERED, 414 .procname = "nsm_local_state", 415 .data = &nsm_local_state, 416 .maxlen = sizeof(int), 417 .mode = 0644, 418 .proc_handler = &proc_dointvec, 419 }, 420 { .ctl_name = 0 } 421 }; 422 423 static ctl_table nlm_sysctl_dir[] = { 424 { 425 .ctl_name = CTL_UNNUMBERED, 426 .procname = "nfs", 427 .mode = 0555, 428 .child = nlm_sysctls, 429 }, 430 { .ctl_name = 0 } 431 }; 432 433 static ctl_table nlm_sysctl_root[] = { 434 { 435 .ctl_name = CTL_FS, 436 .procname = "fs", 437 .mode = 0555, 438 .child = nlm_sysctl_dir, 439 }, 440 { .ctl_name = 0 } 441 }; 442 443 #endif /* CONFIG_SYSCTL */ 444 445 /* 446 * Module (and sysfs) parameters. 447 */ 448 449 #define param_set_min_max(name, type, which_strtol, min, max) \ 450 static int param_set_##name(const char *val, struct kernel_param *kp) \ 451 { \ 452 char *endp; \ 453 __typeof__(type) num = which_strtol(val, &endp, 0); \ 454 if (endp == val || *endp || num < (min) || num > (max)) \ 455 return -EINVAL; \ 456 *((int *) kp->arg) = num; \ 457 return 0; \ 458 } 459 460 static inline int is_callback(u32 proc) 461 { 462 return proc == NLMPROC_GRANTED 463 || proc == NLMPROC_GRANTED_MSG 464 || proc == NLMPROC_TEST_RES 465 || proc == NLMPROC_LOCK_RES 466 || proc == NLMPROC_CANCEL_RES 467 || proc == NLMPROC_UNLOCK_RES 468 || proc == NLMPROC_NSM_NOTIFY; 469 } 470 471 472 static int lockd_authenticate(struct svc_rqst *rqstp) 473 { 474 rqstp->rq_client = NULL; 475 switch (rqstp->rq_authop->flavour) { 476 case RPC_AUTH_NULL: 477 case RPC_AUTH_UNIX: 478 if (rqstp->rq_proc == 0) 479 return SVC_OK; 480 if (is_callback(rqstp->rq_proc)) { 481 /* Leave it to individual procedures to 482 * call nlmsvc_lookup_host(rqstp) 483 */ 484 return SVC_OK; 485 } 486 return svc_set_client(rqstp); 487 } 488 return SVC_DENIED; 489 } 490 491 492 param_set_min_max(port, int, simple_strtol, 0, 65535) 493 param_set_min_max(grace_period, unsigned long, simple_strtoul, 494 nlm_grace_period_min, nlm_grace_period_max) 495 param_set_min_max(timeout, unsigned long, simple_strtoul, 496 nlm_timeout_min, nlm_timeout_max) 497 498 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 499 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 500 MODULE_LICENSE("GPL"); 501 502 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 503 &nlm_grace_period, 0644); 504 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 505 &nlm_timeout, 0644); 506 module_param_call(nlm_udpport, param_set_port, param_get_int, 507 &nlm_udpport, 0644); 508 module_param_call(nlm_tcpport, param_set_port, param_get_int, 509 &nlm_tcpport, 0644); 510 module_param(nsm_use_hostnames, bool, 0644); 511 module_param(nlm_max_connections, uint, 0644); 512 513 /* 514 * Initialising and terminating the module. 515 */ 516 517 static int __init init_nlm(void) 518 { 519 #ifdef CONFIG_SYSCTL 520 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 521 return nlm_sysctl_table ? 0 : -ENOMEM; 522 #else 523 return 0; 524 #endif 525 } 526 527 static void __exit exit_nlm(void) 528 { 529 /* FIXME: delete all NLM clients */ 530 nlm_shutdown_hosts(); 531 #ifdef CONFIG_SYSCTL 532 unregister_sysctl_table(nlm_sysctl_table); 533 #endif 534 } 535 536 module_init(init_nlm); 537 module_exit(exit_nlm); 538 539 /* 540 * Define NLM program and procedures 541 */ 542 static struct svc_version nlmsvc_version1 = { 543 .vs_vers = 1, 544 .vs_nproc = 17, 545 .vs_proc = nlmsvc_procedures, 546 .vs_xdrsize = NLMSVC_XDRSIZE, 547 }; 548 static struct svc_version nlmsvc_version3 = { 549 .vs_vers = 3, 550 .vs_nproc = 24, 551 .vs_proc = nlmsvc_procedures, 552 .vs_xdrsize = NLMSVC_XDRSIZE, 553 }; 554 #ifdef CONFIG_LOCKD_V4 555 static struct svc_version nlmsvc_version4 = { 556 .vs_vers = 4, 557 .vs_nproc = 24, 558 .vs_proc = nlmsvc_procedures4, 559 .vs_xdrsize = NLMSVC_XDRSIZE, 560 }; 561 #endif 562 static struct svc_version * nlmsvc_version[] = { 563 [1] = &nlmsvc_version1, 564 [3] = &nlmsvc_version3, 565 #ifdef CONFIG_LOCKD_V4 566 [4] = &nlmsvc_version4, 567 #endif 568 }; 569 570 static struct svc_stat nlmsvc_stats; 571 572 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 573 static struct svc_program nlmsvc_program = { 574 .pg_prog = NLM_PROGRAM, /* program number */ 575 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 576 .pg_vers = nlmsvc_version, /* version table */ 577 .pg_name = "lockd", /* service name */ 578 .pg_class = "nfsd", /* share authentication with nfsd */ 579 .pg_stats = &nlmsvc_stats, /* stats table */ 580 .pg_authenticate = &lockd_authenticate /* export authentication */ 581 }; 582