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 #define NLMDBG_FACILITY NLMDBG_SVC 39 #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) 40 #define ALLOWED_SIGS (sigmask(SIGKILL)) 41 42 static struct svc_program nlmsvc_program; 43 44 struct nlmsvc_binding * nlmsvc_ops; 45 EXPORT_SYMBOL_GPL(nlmsvc_ops); 46 47 static DEFINE_MUTEX(nlmsvc_mutex); 48 static unsigned int nlmsvc_users; 49 static struct task_struct *nlmsvc_task; 50 static struct svc_rqst *nlmsvc_rqst; 51 unsigned long nlmsvc_timeout; 52 53 /* 54 * These can be set at insmod time (useful for NFS as root filesystem), 55 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 56 */ 57 static unsigned long nlm_grace_period; 58 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 59 static int nlm_udpport, nlm_tcpport; 60 61 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ 62 static unsigned int nlm_max_connections = 1024; 63 64 /* 65 * Constants needed for the sysctl interface. 66 */ 67 static const unsigned long nlm_grace_period_min = 0; 68 static const unsigned long nlm_grace_period_max = 240; 69 static const unsigned long nlm_timeout_min = 3; 70 static const unsigned long nlm_timeout_max = 20; 71 static const int nlm_port_min = 0, nlm_port_max = 65535; 72 73 #ifdef CONFIG_SYSCTL 74 static struct ctl_table_header * nlm_sysctl_table; 75 #endif 76 77 static unsigned long get_lockd_grace_period(void) 78 { 79 /* Note: nlm_timeout should always be nonzero */ 80 if (nlm_grace_period) 81 return roundup(nlm_grace_period, nlm_timeout) * HZ; 82 else 83 return nlm_timeout * 5 * HZ; 84 } 85 86 static struct lock_manager lockd_manager = { 87 }; 88 89 static void grace_ender(struct work_struct *not_used) 90 { 91 locks_end_grace(&lockd_manager); 92 } 93 94 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); 95 96 static void set_grace_period(void) 97 { 98 unsigned long grace_period = get_lockd_grace_period(); 99 100 locks_start_grace(&lockd_manager); 101 cancel_delayed_work_sync(&grace_period_end); 102 schedule_delayed_work(&grace_period_end, grace_period); 103 } 104 105 static void restart_grace(void) 106 { 107 if (nlmsvc_ops) { 108 cancel_delayed_work_sync(&grace_period_end); 109 locks_end_grace(&lockd_manager); 110 nlmsvc_invalidate_all(); 111 set_grace_period(); 112 } 113 } 114 115 /* 116 * This is the lockd kernel thread 117 */ 118 static int 119 lockd(void *vrqstp) 120 { 121 int err = 0, preverr = 0; 122 struct svc_rqst *rqstp = vrqstp; 123 124 /* try_to_freeze() is called from svc_recv() */ 125 set_freezable(); 126 127 /* Allow SIGKILL to tell lockd to drop all of its locks */ 128 allow_signal(SIGKILL); 129 130 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 131 132 if (!nlm_timeout) 133 nlm_timeout = LOCKD_DFLT_TIMEO; 134 nlmsvc_timeout = nlm_timeout * HZ; 135 136 set_grace_period(); 137 138 /* 139 * The main request loop. We don't terminate until the last 140 * NFS mount or NFS daemon has gone away. 141 */ 142 while (!kthread_should_stop()) { 143 long timeout = MAX_SCHEDULE_TIMEOUT; 144 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 145 146 /* update sv_maxconn if it has changed */ 147 rqstp->rq_server->sv_maxconn = nlm_max_connections; 148 149 if (signalled()) { 150 flush_signals(current); 151 restart_grace(); 152 continue; 153 } 154 155 timeout = nlmsvc_retry_blocked(); 156 157 /* 158 * Find a socket with data available and call its 159 * recvfrom routine. 160 */ 161 err = svc_recv(rqstp, timeout); 162 if (err == -EAGAIN || err == -EINTR) { 163 preverr = err; 164 continue; 165 } 166 if (err < 0) { 167 if (err != preverr) { 168 printk(KERN_WARNING "%s: unexpected error " 169 "from svc_recv (%d)\n", __func__, err); 170 preverr = err; 171 } 172 schedule_timeout_interruptible(HZ); 173 continue; 174 } 175 preverr = err; 176 177 dprintk("lockd: request from %s\n", 178 svc_print_addr(rqstp, buf, sizeof(buf))); 179 180 svc_process(rqstp); 181 } 182 flush_signals(current); 183 cancel_delayed_work_sync(&grace_period_end); 184 locks_end_grace(&lockd_manager); 185 if (nlmsvc_ops) 186 nlmsvc_invalidate_all(); 187 nlm_shutdown_hosts(); 188 return 0; 189 } 190 191 static int create_lockd_listener(struct svc_serv *serv, const char *name, 192 const int family, const unsigned short port) 193 { 194 struct svc_xprt *xprt; 195 196 xprt = svc_find_xprt(serv, name, family, 0); 197 if (xprt == NULL) 198 return svc_create_xprt(serv, name, &init_net, family, port, 199 SVC_SOCK_DEFAULTS); 200 svc_xprt_put(xprt); 201 return 0; 202 } 203 204 static int create_lockd_family(struct svc_serv *serv, const int family) 205 { 206 int err; 207 208 err = create_lockd_listener(serv, "udp", family, nlm_udpport); 209 if (err < 0) 210 return err; 211 212 return create_lockd_listener(serv, "tcp", family, nlm_tcpport); 213 } 214 215 /* 216 * Ensure there are active UDP and TCP listeners for lockd. 217 * 218 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some 219 * local services (such as rpc.statd) still require UDP, and 220 * some NFS servers do not yet support NLM over TCP. 221 * 222 * Returns zero if all listeners are available; otherwise a 223 * negative errno value is returned. 224 */ 225 static int make_socks(struct svc_serv *serv) 226 { 227 static int warned; 228 int err; 229 230 err = create_lockd_family(serv, PF_INET); 231 if (err < 0) 232 goto out_err; 233 234 err = create_lockd_family(serv, PF_INET6); 235 if (err < 0 && err != -EAFNOSUPPORT) 236 goto out_err; 237 238 warned = 0; 239 return 0; 240 241 out_err: 242 if (warned++ == 0) 243 printk(KERN_WARNING 244 "lockd_up: makesock failed, error=%d\n", err); 245 return err; 246 } 247 248 /* 249 * Bring up the lockd process if it's not already up. 250 */ 251 int lockd_up(void) 252 { 253 struct svc_serv *serv; 254 int error = 0; 255 256 mutex_lock(&nlmsvc_mutex); 257 /* 258 * Check whether we're already up and running. 259 */ 260 if (nlmsvc_rqst) 261 goto out; 262 263 /* 264 * Sanity check: if there's no pid, 265 * we should be the first user ... 266 */ 267 if (nlmsvc_users) 268 printk(KERN_WARNING 269 "lockd_up: no pid, %d users??\n", nlmsvc_users); 270 271 error = -ENOMEM; 272 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 273 if (!serv) { 274 printk(KERN_WARNING "lockd_up: create service failed\n"); 275 goto out; 276 } 277 278 error = make_socks(serv); 279 if (error < 0) 280 goto destroy_and_out; 281 282 /* 283 * Create the kernel thread and wait for it to start. 284 */ 285 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); 286 if (IS_ERR(nlmsvc_rqst)) { 287 error = PTR_ERR(nlmsvc_rqst); 288 nlmsvc_rqst = NULL; 289 printk(KERN_WARNING 290 "lockd_up: svc_rqst allocation failed, error=%d\n", 291 error); 292 goto destroy_and_out; 293 } 294 295 svc_sock_update_bufs(serv); 296 serv->sv_maxconn = nlm_max_connections; 297 298 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 299 if (IS_ERR(nlmsvc_task)) { 300 error = PTR_ERR(nlmsvc_task); 301 svc_exit_thread(nlmsvc_rqst); 302 nlmsvc_task = NULL; 303 nlmsvc_rqst = NULL; 304 printk(KERN_WARNING 305 "lockd_up: kthread_run failed, error=%d\n", error); 306 goto destroy_and_out; 307 } 308 309 /* 310 * Note: svc_serv structures have an initial use count of 1, 311 * so we exit through here on both success and failure. 312 */ 313 destroy_and_out: 314 svc_destroy(serv); 315 out: 316 if (!error) 317 nlmsvc_users++; 318 mutex_unlock(&nlmsvc_mutex); 319 return error; 320 } 321 EXPORT_SYMBOL_GPL(lockd_up); 322 323 /* 324 * Decrement the user count and bring down lockd if we're the last. 325 */ 326 void 327 lockd_down(void) 328 { 329 mutex_lock(&nlmsvc_mutex); 330 if (nlmsvc_users) { 331 if (--nlmsvc_users) 332 goto out; 333 } else { 334 printk(KERN_ERR "lockd_down: no users! task=%p\n", 335 nlmsvc_task); 336 BUG(); 337 } 338 339 if (!nlmsvc_task) { 340 printk(KERN_ERR "lockd_down: no lockd running.\n"); 341 BUG(); 342 } 343 kthread_stop(nlmsvc_task); 344 svc_exit_thread(nlmsvc_rqst); 345 nlmsvc_task = NULL; 346 nlmsvc_rqst = NULL; 347 out: 348 mutex_unlock(&nlmsvc_mutex); 349 } 350 EXPORT_SYMBOL_GPL(lockd_down); 351 352 #ifdef CONFIG_SYSCTL 353 354 /* 355 * Sysctl parameters (same as module parameters, different interface). 356 */ 357 358 static ctl_table nlm_sysctls[] = { 359 { 360 .procname = "nlm_grace_period", 361 .data = &nlm_grace_period, 362 .maxlen = sizeof(unsigned long), 363 .mode = 0644, 364 .proc_handler = proc_doulongvec_minmax, 365 .extra1 = (unsigned long *) &nlm_grace_period_min, 366 .extra2 = (unsigned long *) &nlm_grace_period_max, 367 }, 368 { 369 .procname = "nlm_timeout", 370 .data = &nlm_timeout, 371 .maxlen = sizeof(unsigned long), 372 .mode = 0644, 373 .proc_handler = proc_doulongvec_minmax, 374 .extra1 = (unsigned long *) &nlm_timeout_min, 375 .extra2 = (unsigned long *) &nlm_timeout_max, 376 }, 377 { 378 .procname = "nlm_udpport", 379 .data = &nlm_udpport, 380 .maxlen = sizeof(int), 381 .mode = 0644, 382 .proc_handler = proc_dointvec_minmax, 383 .extra1 = (int *) &nlm_port_min, 384 .extra2 = (int *) &nlm_port_max, 385 }, 386 { 387 .procname = "nlm_tcpport", 388 .data = &nlm_tcpport, 389 .maxlen = sizeof(int), 390 .mode = 0644, 391 .proc_handler = proc_dointvec_minmax, 392 .extra1 = (int *) &nlm_port_min, 393 .extra2 = (int *) &nlm_port_max, 394 }, 395 { 396 .procname = "nsm_use_hostnames", 397 .data = &nsm_use_hostnames, 398 .maxlen = sizeof(int), 399 .mode = 0644, 400 .proc_handler = proc_dointvec, 401 }, 402 { 403 .procname = "nsm_local_state", 404 .data = &nsm_local_state, 405 .maxlen = sizeof(int), 406 .mode = 0644, 407 .proc_handler = proc_dointvec, 408 }, 409 { } 410 }; 411 412 static ctl_table nlm_sysctl_dir[] = { 413 { 414 .procname = "nfs", 415 .mode = 0555, 416 .child = nlm_sysctls, 417 }, 418 { } 419 }; 420 421 static ctl_table nlm_sysctl_root[] = { 422 { 423 .procname = "fs", 424 .mode = 0555, 425 .child = nlm_sysctl_dir, 426 }, 427 { } 428 }; 429 430 #endif /* CONFIG_SYSCTL */ 431 432 /* 433 * Module (and sysfs) parameters. 434 */ 435 436 #define param_set_min_max(name, type, which_strtol, min, max) \ 437 static int param_set_##name(const char *val, struct kernel_param *kp) \ 438 { \ 439 char *endp; \ 440 __typeof__(type) num = which_strtol(val, &endp, 0); \ 441 if (endp == val || *endp || num < (min) || num > (max)) \ 442 return -EINVAL; \ 443 *((int *) kp->arg) = num; \ 444 return 0; \ 445 } 446 447 static inline int is_callback(u32 proc) 448 { 449 return proc == NLMPROC_GRANTED 450 || proc == NLMPROC_GRANTED_MSG 451 || proc == NLMPROC_TEST_RES 452 || proc == NLMPROC_LOCK_RES 453 || proc == NLMPROC_CANCEL_RES 454 || proc == NLMPROC_UNLOCK_RES 455 || proc == NLMPROC_NSM_NOTIFY; 456 } 457 458 459 static int lockd_authenticate(struct svc_rqst *rqstp) 460 { 461 rqstp->rq_client = NULL; 462 switch (rqstp->rq_authop->flavour) { 463 case RPC_AUTH_NULL: 464 case RPC_AUTH_UNIX: 465 if (rqstp->rq_proc == 0) 466 return SVC_OK; 467 if (is_callback(rqstp->rq_proc)) { 468 /* Leave it to individual procedures to 469 * call nlmsvc_lookup_host(rqstp) 470 */ 471 return SVC_OK; 472 } 473 return svc_set_client(rqstp); 474 } 475 return SVC_DENIED; 476 } 477 478 479 param_set_min_max(port, int, simple_strtol, 0, 65535) 480 param_set_min_max(grace_period, unsigned long, simple_strtoul, 481 nlm_grace_period_min, nlm_grace_period_max) 482 param_set_min_max(timeout, unsigned long, simple_strtoul, 483 nlm_timeout_min, nlm_timeout_max) 484 485 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 486 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 487 MODULE_LICENSE("GPL"); 488 489 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 490 &nlm_grace_period, 0644); 491 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 492 &nlm_timeout, 0644); 493 module_param_call(nlm_udpport, param_set_port, param_get_int, 494 &nlm_udpport, 0644); 495 module_param_call(nlm_tcpport, param_set_port, param_get_int, 496 &nlm_tcpport, 0644); 497 module_param(nsm_use_hostnames, bool, 0644); 498 module_param(nlm_max_connections, uint, 0644); 499 500 /* 501 * Initialising and terminating the module. 502 */ 503 504 static int __init init_nlm(void) 505 { 506 #ifdef CONFIG_SYSCTL 507 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 508 return nlm_sysctl_table ? 0 : -ENOMEM; 509 #else 510 return 0; 511 #endif 512 } 513 514 static void __exit exit_nlm(void) 515 { 516 /* FIXME: delete all NLM clients */ 517 nlm_shutdown_hosts(); 518 #ifdef CONFIG_SYSCTL 519 unregister_sysctl_table(nlm_sysctl_table); 520 #endif 521 } 522 523 module_init(init_nlm); 524 module_exit(exit_nlm); 525 526 /* 527 * Define NLM program and procedures 528 */ 529 static struct svc_version nlmsvc_version1 = { 530 .vs_vers = 1, 531 .vs_nproc = 17, 532 .vs_proc = nlmsvc_procedures, 533 .vs_xdrsize = NLMSVC_XDRSIZE, 534 }; 535 static struct svc_version nlmsvc_version3 = { 536 .vs_vers = 3, 537 .vs_nproc = 24, 538 .vs_proc = nlmsvc_procedures, 539 .vs_xdrsize = NLMSVC_XDRSIZE, 540 }; 541 #ifdef CONFIG_LOCKD_V4 542 static struct svc_version nlmsvc_version4 = { 543 .vs_vers = 4, 544 .vs_nproc = 24, 545 .vs_proc = nlmsvc_procedures4, 546 .vs_xdrsize = NLMSVC_XDRSIZE, 547 }; 548 #endif 549 static struct svc_version * nlmsvc_version[] = { 550 [1] = &nlmsvc_version1, 551 [3] = &nlmsvc_version3, 552 #ifdef CONFIG_LOCKD_V4 553 [4] = &nlmsvc_version4, 554 #endif 555 }; 556 557 static struct svc_stat nlmsvc_stats; 558 559 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 560 static struct svc_program nlmsvc_program = { 561 .pg_prog = NLM_PROGRAM, /* program number */ 562 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 563 .pg_vers = nlmsvc_version, /* version table */ 564 .pg_name = "lockd", /* service name */ 565 .pg_class = "nfsd", /* share authentication with nfsd */ 566 .pg_stats = &nlmsvc_stats, /* stats table */ 567 .pg_authenticate = &lockd_authenticate /* export authentication */ 568 }; 569