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/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/lockd/sm_inter.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(nlmsvc_ops); 48 49 static DEFINE_MUTEX(nlmsvc_mutex); 50 static unsigned int nlmsvc_users; 51 static pid_t nlmsvc_pid; 52 static struct svc_serv *nlmsvc_serv; 53 int nlmsvc_grace_period; 54 unsigned long nlmsvc_timeout; 55 56 static DECLARE_COMPLETION(lockd_start_done); 57 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit); 58 59 /* 60 * These can be set at insmod time (useful for NFS as root filesystem), 61 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 62 */ 63 static unsigned long nlm_grace_period; 64 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 65 static int nlm_udpport, nlm_tcpport; 66 int nsm_use_hostnames = 0; 67 68 /* 69 * Constants needed for the sysctl interface. 70 */ 71 static const unsigned long nlm_grace_period_min = 0; 72 static const unsigned long nlm_grace_period_max = 240; 73 static const unsigned long nlm_timeout_min = 3; 74 static const unsigned long nlm_timeout_max = 20; 75 static const int nlm_port_min = 0, nlm_port_max = 65535; 76 77 static struct ctl_table_header * nlm_sysctl_table; 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 unsigned long get_nfs_grace_period(void) 89 { 90 unsigned long lockdgrace = get_lockd_grace_period(); 91 unsigned long nfsdgrace = 0; 92 93 if (nlmsvc_ops) 94 nfsdgrace = nlmsvc_ops->get_grace_period(); 95 96 return max(lockdgrace, nfsdgrace); 97 } 98 EXPORT_SYMBOL(get_nfs_grace_period); 99 100 static unsigned long set_grace_period(void) 101 { 102 nlmsvc_grace_period = 1; 103 return get_nfs_grace_period() + jiffies; 104 } 105 106 static inline void clear_grace_period(void) 107 { 108 nlmsvc_grace_period = 0; 109 } 110 111 /* 112 * This is the lockd kernel thread 113 */ 114 static void 115 lockd(struct svc_rqst *rqstp) 116 { 117 int err = 0; 118 unsigned long grace_period_expire; 119 120 /* Lock module and set up kernel thread */ 121 /* lockd_up is waiting for us to startup, so will 122 * be holding a reference to this module, so it 123 * is safe to just claim another reference 124 */ 125 __module_get(THIS_MODULE); 126 lock_kernel(); 127 128 /* 129 * Let our maker know we're running. 130 */ 131 nlmsvc_pid = current->pid; 132 nlmsvc_serv = rqstp->rq_server; 133 complete(&lockd_start_done); 134 135 daemonize("lockd"); 136 set_freezable(); 137 138 /* Process request with signals blocked, but allow SIGKILL. */ 139 allow_signal(SIGKILL); 140 141 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 142 143 if (!nlm_timeout) 144 nlm_timeout = LOCKD_DFLT_TIMEO; 145 nlmsvc_timeout = nlm_timeout * HZ; 146 147 grace_period_expire = 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, and we've been sent a 152 * signal, or else another process has taken over our job. 153 */ 154 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) { 155 long timeout = MAX_SCHEDULE_TIMEOUT; 156 char buf[RPC_MAX_ADDRBUFLEN]; 157 158 if (signalled()) { 159 flush_signals(current); 160 if (nlmsvc_ops) { 161 nlmsvc_invalidate_all(); 162 grace_period_expire = set_grace_period(); 163 } 164 } 165 166 /* 167 * Retry any blocked locks that have been notified by 168 * the VFS. Don't do this during grace period. 169 * (Theoretically, there shouldn't even be blocked locks 170 * during grace period). 171 */ 172 if (!nlmsvc_grace_period) { 173 timeout = nlmsvc_retry_blocked(); 174 } else if (time_before(grace_period_expire, jiffies)) 175 clear_grace_period(); 176 177 /* 178 * Find a socket with data available and call its 179 * recvfrom routine. 180 */ 181 err = svc_recv(rqstp, timeout); 182 if (err == -EAGAIN || err == -EINTR) 183 continue; 184 if (err < 0) { 185 printk(KERN_WARNING 186 "lockd: terminating on error %d\n", 187 -err); 188 break; 189 } 190 191 dprintk("lockd: request from %s\n", 192 svc_print_addr(rqstp, buf, sizeof(buf))); 193 194 svc_process(rqstp); 195 } 196 197 flush_signals(current); 198 199 /* 200 * Check whether there's a new lockd process before 201 * shutting down the hosts and clearing the slot. 202 */ 203 if (!nlmsvc_pid || current->pid == nlmsvc_pid) { 204 if (nlmsvc_ops) 205 nlmsvc_invalidate_all(); 206 nlm_shutdown_hosts(); 207 nlmsvc_pid = 0; 208 nlmsvc_serv = NULL; 209 } else 210 printk(KERN_DEBUG 211 "lockd: new process, skipping host shutdown\n"); 212 wake_up(&lockd_exit); 213 214 /* Exit the RPC thread */ 215 svc_exit_thread(rqstp); 216 217 /* Release module */ 218 unlock_kernel(); 219 module_put_and_exit(0); 220 } 221 222 /* 223 * Make any sockets that are needed but not present. 224 * If nlm_udpport or nlm_tcpport were set as module 225 * options, make those sockets unconditionally 226 */ 227 static int make_socks(struct svc_serv *serv, int proto) 228 { 229 static int warned; 230 struct svc_xprt *xprt; 231 int err = 0; 232 233 if (proto == IPPROTO_UDP || nlm_udpport) { 234 xprt = svc_find_xprt(serv, "udp", 0, 0); 235 if (!xprt) 236 err = svc_create_xprt(serv, "udp", nlm_udpport, 237 SVC_SOCK_DEFAULTS); 238 else 239 svc_xprt_put(xprt); 240 } 241 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) { 242 xprt = svc_find_xprt(serv, "tcp", 0, 0); 243 if (!xprt) 244 err = svc_create_xprt(serv, "tcp", nlm_tcpport, 245 SVC_SOCK_DEFAULTS); 246 else 247 svc_xprt_put(xprt); 248 } 249 if (err >= 0) { 250 warned = 0; 251 err = 0; 252 } else if (warned++ == 0) 253 printk(KERN_WARNING 254 "lockd_up: makesock failed, error=%d\n", err); 255 return err; 256 } 257 258 /* 259 * Bring up the lockd process if it's not already up. 260 */ 261 int 262 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 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_pid) { 272 if (proto) 273 error = make_socks(nlmsvc_serv, proto); 274 goto out; 275 } 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 if ((error = make_socks(serv, proto)) < 0) 293 goto destroy_and_out; 294 295 /* 296 * Create the kernel thread and wait for it to start. 297 */ 298 error = svc_create_thread(lockd, serv); 299 if (error) { 300 printk(KERN_WARNING 301 "lockd_up: create thread failed, error=%d\n", error); 302 goto destroy_and_out; 303 } 304 wait_for_completion(&lockd_start_done); 305 306 /* 307 * Note: svc_serv structures have an initial use count of 1, 308 * so we exit through here on both success and failure. 309 */ 310 destroy_and_out: 311 svc_destroy(serv); 312 out: 313 if (!error) 314 nlmsvc_users++; 315 mutex_unlock(&nlmsvc_mutex); 316 return error; 317 } 318 EXPORT_SYMBOL(lockd_up); 319 320 /* 321 * Decrement the user count and bring down lockd if we're the last. 322 */ 323 void 324 lockd_down(void) 325 { 326 static int warned; 327 328 mutex_lock(&nlmsvc_mutex); 329 if (nlmsvc_users) { 330 if (--nlmsvc_users) 331 goto out; 332 } else 333 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid); 334 335 if (!nlmsvc_pid) { 336 if (warned++ == 0) 337 printk(KERN_WARNING "lockd_down: no lockd running.\n"); 338 goto out; 339 } 340 warned = 0; 341 342 kill_proc(nlmsvc_pid, SIGKILL, 1); 343 /* 344 * Wait for the lockd process to exit, but since we're holding 345 * the lockd semaphore, we can't wait around forever ... 346 */ 347 clear_thread_flag(TIF_SIGPENDING); 348 interruptible_sleep_on_timeout(&lockd_exit, HZ); 349 if (nlmsvc_pid) { 350 printk(KERN_WARNING 351 "lockd_down: lockd failed to exit, clearing pid\n"); 352 nlmsvc_pid = 0; 353 } 354 spin_lock_irq(¤t->sighand->siglock); 355 recalc_sigpending(); 356 spin_unlock_irq(¤t->sighand->siglock); 357 out: 358 mutex_unlock(&nlmsvc_mutex); 359 } 360 EXPORT_SYMBOL(lockd_down); 361 362 /* 363 * Sysctl parameters (same as module parameters, different interface). 364 */ 365 366 static ctl_table nlm_sysctls[] = { 367 { 368 .ctl_name = CTL_UNNUMBERED, 369 .procname = "nlm_grace_period", 370 .data = &nlm_grace_period, 371 .maxlen = sizeof(unsigned long), 372 .mode = 0644, 373 .proc_handler = &proc_doulongvec_minmax, 374 .extra1 = (unsigned long *) &nlm_grace_period_min, 375 .extra2 = (unsigned long *) &nlm_grace_period_max, 376 }, 377 { 378 .ctl_name = CTL_UNNUMBERED, 379 .procname = "nlm_timeout", 380 .data = &nlm_timeout, 381 .maxlen = sizeof(unsigned long), 382 .mode = 0644, 383 .proc_handler = &proc_doulongvec_minmax, 384 .extra1 = (unsigned long *) &nlm_timeout_min, 385 .extra2 = (unsigned long *) &nlm_timeout_max, 386 }, 387 { 388 .ctl_name = CTL_UNNUMBERED, 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 .ctl_name = CTL_UNNUMBERED, 399 .procname = "nlm_tcpport", 400 .data = &nlm_tcpport, 401 .maxlen = sizeof(int), 402 .mode = 0644, 403 .proc_handler = &proc_dointvec_minmax, 404 .extra1 = (int *) &nlm_port_min, 405 .extra2 = (int *) &nlm_port_max, 406 }, 407 { 408 .ctl_name = CTL_UNNUMBERED, 409 .procname = "nsm_use_hostnames", 410 .data = &nsm_use_hostnames, 411 .maxlen = sizeof(int), 412 .mode = 0644, 413 .proc_handler = &proc_dointvec, 414 }, 415 { 416 .ctl_name = CTL_UNNUMBERED, 417 .procname = "nsm_local_state", 418 .data = &nsm_local_state, 419 .maxlen = sizeof(int), 420 .mode = 0644, 421 .proc_handler = &proc_dointvec, 422 }, 423 { .ctl_name = 0 } 424 }; 425 426 static ctl_table nlm_sysctl_dir[] = { 427 { 428 .ctl_name = CTL_UNNUMBERED, 429 .procname = "nfs", 430 .mode = 0555, 431 .child = nlm_sysctls, 432 }, 433 { .ctl_name = 0 } 434 }; 435 436 static ctl_table nlm_sysctl_root[] = { 437 { 438 .ctl_name = CTL_FS, 439 .procname = "fs", 440 .mode = 0555, 441 .child = nlm_sysctl_dir, 442 }, 443 { .ctl_name = 0 } 444 }; 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); 512 513 /* 514 * Initialising and terminating the module. 515 */ 516 517 static int __init init_nlm(void) 518 { 519 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 520 return nlm_sysctl_table ? 0 : -ENOMEM; 521 } 522 523 static void __exit exit_nlm(void) 524 { 525 /* FIXME: delete all NLM clients */ 526 nlm_shutdown_hosts(); 527 unregister_sysctl_table(nlm_sysctl_table); 528 } 529 530 module_init(init_nlm); 531 module_exit(exit_nlm); 532 533 /* 534 * Define NLM program and procedures 535 */ 536 static struct svc_version nlmsvc_version1 = { 537 .vs_vers = 1, 538 .vs_nproc = 17, 539 .vs_proc = nlmsvc_procedures, 540 .vs_xdrsize = NLMSVC_XDRSIZE, 541 }; 542 static struct svc_version nlmsvc_version3 = { 543 .vs_vers = 3, 544 .vs_nproc = 24, 545 .vs_proc = nlmsvc_procedures, 546 .vs_xdrsize = NLMSVC_XDRSIZE, 547 }; 548 #ifdef CONFIG_LOCKD_V4 549 static struct svc_version nlmsvc_version4 = { 550 .vs_vers = 4, 551 .vs_nproc = 24, 552 .vs_proc = nlmsvc_procedures4, 553 .vs_xdrsize = NLMSVC_XDRSIZE, 554 }; 555 #endif 556 static struct svc_version * nlmsvc_version[] = { 557 [1] = &nlmsvc_version1, 558 [3] = &nlmsvc_version3, 559 #ifdef CONFIG_LOCKD_V4 560 [4] = &nlmsvc_version4, 561 #endif 562 }; 563 564 static struct svc_stat nlmsvc_stats; 565 566 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 567 static struct svc_program nlmsvc_program = { 568 .pg_prog = NLM_PROGRAM, /* program number */ 569 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 570 .pg_vers = nlmsvc_version, /* version table */ 571 .pg_name = "lockd", /* service name */ 572 .pg_class = "nfsd", /* share authentication with nfsd */ 573 .pg_stats = &nlmsvc_stats, /* stats table */ 574 .pg_authenticate = &lockd_authenticate /* export authentication */ 575 }; 576