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 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/lockd/sm_inter.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(nlmsvc_ops); 47 48 static DEFINE_MUTEX(nlmsvc_mutex); 49 static unsigned int nlmsvc_users; 50 static pid_t nlmsvc_pid; 51 static struct svc_serv *nlmsvc_serv; 52 int nlmsvc_grace_period; 53 unsigned long nlmsvc_timeout; 54 55 static DECLARE_COMPLETION(lockd_start_done); 56 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit); 57 58 /* 59 * These can be set at insmod time (useful for NFS as root filesystem), 60 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 61 */ 62 static unsigned long nlm_grace_period; 63 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 64 static int nlm_udpport, nlm_tcpport; 65 int nsm_use_hostnames = 0; 66 67 /* 68 * Constants needed for the sysctl interface. 69 */ 70 static const unsigned long nlm_grace_period_min = 0; 71 static const unsigned long nlm_grace_period_max = 240; 72 static const unsigned long nlm_timeout_min = 3; 73 static const unsigned long nlm_timeout_max = 20; 74 static const int nlm_port_min = 0, nlm_port_max = 65535; 75 76 static struct ctl_table_header * nlm_sysctl_table; 77 78 static unsigned long set_grace_period(void) 79 { 80 unsigned long grace_period; 81 82 /* Note: nlm_timeout should always be nonzero */ 83 if (nlm_grace_period) 84 grace_period = ((nlm_grace_period + nlm_timeout - 1) 85 / nlm_timeout) * nlm_timeout * HZ; 86 else 87 grace_period = nlm_timeout * 5 * HZ; 88 nlmsvc_grace_period = 1; 89 return grace_period + jiffies; 90 } 91 92 static inline void clear_grace_period(void) 93 { 94 nlmsvc_grace_period = 0; 95 } 96 97 /* 98 * This is the lockd kernel thread 99 */ 100 static void 101 lockd(struct svc_rqst *rqstp) 102 { 103 int err = 0; 104 unsigned long grace_period_expire; 105 106 /* Lock module and set up kernel thread */ 107 /* lockd_up is waiting for us to startup, so will 108 * be holding a reference to this module, so it 109 * is safe to just claim another reference 110 */ 111 __module_get(THIS_MODULE); 112 lock_kernel(); 113 114 /* 115 * Let our maker know we're running. 116 */ 117 nlmsvc_pid = current->pid; 118 nlmsvc_serv = rqstp->rq_server; 119 complete(&lockd_start_done); 120 121 daemonize("lockd"); 122 123 /* Process request with signals blocked, but allow SIGKILL. */ 124 allow_signal(SIGKILL); 125 126 /* kick rpciod */ 127 rpciod_up(); 128 129 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 130 131 if (!nlm_timeout) 132 nlm_timeout = LOCKD_DFLT_TIMEO; 133 nlmsvc_timeout = nlm_timeout * HZ; 134 135 grace_period_expire = set_grace_period(); 136 137 /* 138 * The main request loop. We don't terminate until the last 139 * NFS mount or NFS daemon has gone away, and we've been sent a 140 * signal, or else another process has taken over our job. 141 */ 142 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) { 143 long timeout = MAX_SCHEDULE_TIMEOUT; 144 145 if (signalled()) { 146 flush_signals(current); 147 if (nlmsvc_ops) { 148 nlmsvc_invalidate_all(); 149 grace_period_expire = set_grace_period(); 150 } 151 } 152 153 /* 154 * Retry any blocked locks that have been notified by 155 * the VFS. Don't do this during grace period. 156 * (Theoretically, there shouldn't even be blocked locks 157 * during grace period). 158 */ 159 if (!nlmsvc_grace_period) { 160 timeout = nlmsvc_retry_blocked(); 161 } else if (time_before(grace_period_expire, jiffies)) 162 clear_grace_period(); 163 164 /* 165 * Find a socket with data available and call its 166 * recvfrom routine. 167 */ 168 err = svc_recv(rqstp, timeout); 169 if (err == -EAGAIN || err == -EINTR) 170 continue; 171 if (err < 0) { 172 printk(KERN_WARNING 173 "lockd: terminating on error %d\n", 174 -err); 175 break; 176 } 177 178 dprintk("lockd: request from %08x\n", 179 (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr)); 180 181 svc_process(rqstp); 182 183 } 184 185 flush_signals(current); 186 187 /* 188 * Check whether there's a new lockd process before 189 * shutting down the hosts and clearing the slot. 190 */ 191 if (!nlmsvc_pid || current->pid == nlmsvc_pid) { 192 if (nlmsvc_ops) 193 nlmsvc_invalidate_all(); 194 nlm_shutdown_hosts(); 195 nlmsvc_pid = 0; 196 nlmsvc_serv = NULL; 197 } else 198 printk(KERN_DEBUG 199 "lockd: new process, skipping host shutdown\n"); 200 wake_up(&lockd_exit); 201 202 /* Exit the RPC thread */ 203 svc_exit_thread(rqstp); 204 205 /* release rpciod */ 206 rpciod_down(); 207 208 /* Release module */ 209 unlock_kernel(); 210 module_put_and_exit(0); 211 } 212 213 214 static int find_socket(struct svc_serv *serv, int proto) 215 { 216 struct svc_sock *svsk; 217 int found = 0; 218 list_for_each_entry(svsk, &serv->sv_permsocks, sk_list) 219 if (svsk->sk_sk->sk_protocol == proto) { 220 found = 1; 221 break; 222 } 223 return found; 224 } 225 226 static int make_socks(struct svc_serv *serv, int proto) 227 { 228 /* Make any sockets that are needed but not present. 229 * If nlm_udpport or nlm_tcpport were set as module 230 * options, make those sockets unconditionally 231 */ 232 static int warned; 233 int err = 0; 234 if (proto == IPPROTO_UDP || nlm_udpport) 235 if (!find_socket(serv, IPPROTO_UDP)) 236 err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport); 237 if (err == 0 && (proto == IPPROTO_TCP || nlm_tcpport)) 238 if (!find_socket(serv, IPPROTO_TCP)) 239 err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport); 240 if (!err) 241 warned = 0; 242 else 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 252 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 253 { 254 struct svc_serv * serv; 255 int error = 0; 256 257 mutex_lock(&nlmsvc_mutex); 258 /* 259 * Check whether we're already up and running. 260 */ 261 if (nlmsvc_pid) { 262 if (proto) 263 error = make_socks(nlmsvc_serv, proto); 264 goto out; 265 } 266 267 /* 268 * Sanity check: if there's no pid, 269 * we should be the first user ... 270 */ 271 if (nlmsvc_users) 272 printk(KERN_WARNING 273 "lockd_up: no pid, %d users??\n", nlmsvc_users); 274 275 error = -ENOMEM; 276 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 277 if (!serv) { 278 printk(KERN_WARNING "lockd_up: create service failed\n"); 279 goto out; 280 } 281 282 if ((error = make_socks(serv, proto)) < 0) 283 goto destroy_and_out; 284 285 /* 286 * Create the kernel thread and wait for it to start. 287 */ 288 error = svc_create_thread(lockd, serv); 289 if (error) { 290 printk(KERN_WARNING 291 "lockd_up: create thread failed, error=%d\n", error); 292 goto destroy_and_out; 293 } 294 wait_for_completion(&lockd_start_done); 295 296 /* 297 * Note: svc_serv structures have an initial use count of 1, 298 * so we exit through here on both success and failure. 299 */ 300 destroy_and_out: 301 svc_destroy(serv); 302 out: 303 if (!error) 304 nlmsvc_users++; 305 mutex_unlock(&nlmsvc_mutex); 306 return error; 307 } 308 EXPORT_SYMBOL(lockd_up); 309 310 /* 311 * Decrement the user count and bring down lockd if we're the last. 312 */ 313 void 314 lockd_down(void) 315 { 316 static int warned; 317 318 mutex_lock(&nlmsvc_mutex); 319 if (nlmsvc_users) { 320 if (--nlmsvc_users) 321 goto out; 322 } else 323 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid); 324 325 if (!nlmsvc_pid) { 326 if (warned++ == 0) 327 printk(KERN_WARNING "lockd_down: no lockd running.\n"); 328 goto out; 329 } 330 warned = 0; 331 332 kill_proc(nlmsvc_pid, SIGKILL, 1); 333 /* 334 * Wait for the lockd process to exit, but since we're holding 335 * the lockd semaphore, we can't wait around forever ... 336 */ 337 clear_thread_flag(TIF_SIGPENDING); 338 interruptible_sleep_on_timeout(&lockd_exit, HZ); 339 if (nlmsvc_pid) { 340 printk(KERN_WARNING 341 "lockd_down: lockd failed to exit, clearing pid\n"); 342 nlmsvc_pid = 0; 343 } 344 spin_lock_irq(¤t->sighand->siglock); 345 recalc_sigpending(); 346 spin_unlock_irq(¤t->sighand->siglock); 347 out: 348 mutex_unlock(&nlmsvc_mutex); 349 } 350 EXPORT_SYMBOL(lockd_down); 351 352 /* 353 * Sysctl parameters (same as module parameters, different interface). 354 */ 355 356 static ctl_table nlm_sysctls[] = { 357 { 358 .ctl_name = CTL_UNNUMBERED, 359 .procname = "nlm_grace_period", 360 .data = &nlm_grace_period, 361 .maxlen = sizeof(unsigned long), 362 .mode = 0644, 363 .proc_handler = &proc_doulongvec_minmax, 364 .extra1 = (unsigned long *) &nlm_grace_period_min, 365 .extra2 = (unsigned long *) &nlm_grace_period_max, 366 }, 367 { 368 .ctl_name = CTL_UNNUMBERED, 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 .ctl_name = CTL_UNNUMBERED, 379 .procname = "nlm_udpport", 380 .data = &nlm_udpport, 381 .maxlen = sizeof(int), 382 .mode = 0644, 383 .proc_handler = &proc_dointvec_minmax, 384 .extra1 = (int *) &nlm_port_min, 385 .extra2 = (int *) &nlm_port_max, 386 }, 387 { 388 .ctl_name = CTL_UNNUMBERED, 389 .procname = "nlm_tcpport", 390 .data = &nlm_tcpport, 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 = "nsm_use_hostnames", 400 .data = &nsm_use_hostnames, 401 .maxlen = sizeof(int), 402 .mode = 0644, 403 .proc_handler = &proc_dointvec, 404 }, 405 { 406 .ctl_name = CTL_UNNUMBERED, 407 .procname = "nsm_local_state", 408 .data = &nsm_local_state, 409 .maxlen = sizeof(int), 410 .mode = 0644, 411 .proc_handler = &proc_dointvec, 412 }, 413 { .ctl_name = 0 } 414 }; 415 416 static ctl_table nlm_sysctl_dir[] = { 417 { 418 .ctl_name = CTL_UNNUMBERED, 419 .procname = "nfs", 420 .mode = 0555, 421 .child = nlm_sysctls, 422 }, 423 { .ctl_name = 0 } 424 }; 425 426 static ctl_table nlm_sysctl_root[] = { 427 { 428 .ctl_name = CTL_FS, 429 .procname = "fs", 430 .mode = 0555, 431 .child = nlm_sysctl_dir, 432 }, 433 { .ctl_name = 0 } 434 }; 435 436 /* 437 * Module (and driverfs) parameters. 438 */ 439 440 #define param_set_min_max(name, type, which_strtol, min, max) \ 441 static int param_set_##name(const char *val, struct kernel_param *kp) \ 442 { \ 443 char *endp; \ 444 __typeof__(type) num = which_strtol(val, &endp, 0); \ 445 if (endp == val || *endp || num < (min) || num > (max)) \ 446 return -EINVAL; \ 447 *((int *) kp->arg) = num; \ 448 return 0; \ 449 } 450 451 static inline int is_callback(u32 proc) 452 { 453 return proc == NLMPROC_GRANTED 454 || proc == NLMPROC_GRANTED_MSG 455 || proc == NLMPROC_TEST_RES 456 || proc == NLMPROC_LOCK_RES 457 || proc == NLMPROC_CANCEL_RES 458 || proc == NLMPROC_UNLOCK_RES 459 || proc == NLMPROC_NSM_NOTIFY; 460 } 461 462 463 static int lockd_authenticate(struct svc_rqst *rqstp) 464 { 465 rqstp->rq_client = NULL; 466 switch (rqstp->rq_authop->flavour) { 467 case RPC_AUTH_NULL: 468 case RPC_AUTH_UNIX: 469 if (rqstp->rq_proc == 0) 470 return SVC_OK; 471 if (is_callback(rqstp->rq_proc)) { 472 /* Leave it to individual procedures to 473 * call nlmsvc_lookup_host(rqstp) 474 */ 475 return SVC_OK; 476 } 477 return svc_set_client(rqstp); 478 } 479 return SVC_DENIED; 480 } 481 482 483 param_set_min_max(port, int, simple_strtol, 0, 65535) 484 param_set_min_max(grace_period, unsigned long, simple_strtoul, 485 nlm_grace_period_min, nlm_grace_period_max) 486 param_set_min_max(timeout, unsigned long, simple_strtoul, 487 nlm_timeout_min, nlm_timeout_max) 488 489 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 490 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 491 MODULE_LICENSE("GPL"); 492 493 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 494 &nlm_grace_period, 0644); 495 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 496 &nlm_timeout, 0644); 497 module_param_call(nlm_udpport, param_set_port, param_get_int, 498 &nlm_udpport, 0644); 499 module_param_call(nlm_tcpport, param_set_port, param_get_int, 500 &nlm_tcpport, 0644); 501 module_param(nsm_use_hostnames, bool, 0644); 502 503 /* 504 * Initialising and terminating the module. 505 */ 506 507 static int __init init_nlm(void) 508 { 509 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0); 510 return nlm_sysctl_table ? 0 : -ENOMEM; 511 } 512 513 static void __exit exit_nlm(void) 514 { 515 /* FIXME: delete all NLM clients */ 516 nlm_shutdown_hosts(); 517 unregister_sysctl_table(nlm_sysctl_table); 518 } 519 520 module_init(init_nlm); 521 module_exit(exit_nlm); 522 523 /* 524 * Define NLM program and procedures 525 */ 526 static struct svc_version nlmsvc_version1 = { 527 .vs_vers = 1, 528 .vs_nproc = 17, 529 .vs_proc = nlmsvc_procedures, 530 .vs_xdrsize = NLMSVC_XDRSIZE, 531 }; 532 static struct svc_version nlmsvc_version3 = { 533 .vs_vers = 3, 534 .vs_nproc = 24, 535 .vs_proc = nlmsvc_procedures, 536 .vs_xdrsize = NLMSVC_XDRSIZE, 537 }; 538 #ifdef CONFIG_LOCKD_V4 539 static struct svc_version nlmsvc_version4 = { 540 .vs_vers = 4, 541 .vs_nproc = 24, 542 .vs_proc = nlmsvc_procedures4, 543 .vs_xdrsize = NLMSVC_XDRSIZE, 544 }; 545 #endif 546 static struct svc_version * nlmsvc_version[] = { 547 [1] = &nlmsvc_version1, 548 [3] = &nlmsvc_version3, 549 #ifdef CONFIG_LOCKD_V4 550 [4] = &nlmsvc_version4, 551 #endif 552 }; 553 554 static struct svc_stat nlmsvc_stats; 555 556 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 557 static struct svc_program nlmsvc_program = { 558 .pg_prog = NLM_PROGRAM, /* program number */ 559 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 560 .pg_vers = nlmsvc_version, /* version table */ 561 .pg_name = "lockd", /* service name */ 562 .pg_class = "nfsd", /* share authentication with nfsd */ 563 .pg_stats = &nlmsvc_stats, /* stats table */ 564 .pg_authenticate = &lockd_authenticate /* export authentication */ 565 }; 566