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 char buf[RPC_MAX_ADDRBUFLEN]; 145 146 if (signalled()) { 147 flush_signals(current); 148 if (nlmsvc_ops) { 149 nlmsvc_invalidate_all(); 150 grace_period_expire = set_grace_period(); 151 } 152 } 153 154 /* 155 * Retry any blocked locks that have been notified by 156 * the VFS. Don't do this during grace period. 157 * (Theoretically, there shouldn't even be blocked locks 158 * during grace period). 159 */ 160 if (!nlmsvc_grace_period) { 161 timeout = nlmsvc_retry_blocked(); 162 } else if (time_before(grace_period_expire, jiffies)) 163 clear_grace_period(); 164 165 /* 166 * Find a socket with data available and call its 167 * recvfrom routine. 168 */ 169 err = svc_recv(rqstp, timeout); 170 if (err == -EAGAIN || err == -EINTR) 171 continue; 172 if (err < 0) { 173 printk(KERN_WARNING 174 "lockd: terminating on error %d\n", 175 -err); 176 break; 177 } 178 179 dprintk("lockd: request from %s\n", 180 svc_print_addr(rqstp, buf, sizeof(buf))); 181 182 svc_process(rqstp); 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 /* 227 * Make any sockets that are needed but not present. 228 * If nlm_udpport or nlm_tcpport were set as module 229 * options, make those sockets unconditionally 230 */ 231 static int make_socks(struct svc_serv *serv, int proto) 232 { 233 static int warned; 234 int err = 0; 235 236 if (proto == IPPROTO_UDP || nlm_udpport) 237 if (!find_socket(serv, IPPROTO_UDP)) 238 err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport, 239 SVC_SOCK_DEFAULTS); 240 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) 241 if (!find_socket(serv, IPPROTO_TCP)) 242 err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport, 243 SVC_SOCK_DEFAULTS); 244 245 if (err >= 0) { 246 warned = 0; 247 err = 0; 248 } else if (warned++ == 0) 249 printk(KERN_WARNING 250 "lockd_up: makesock failed, error=%d\n", err); 251 return err; 252 } 253 254 /* 255 * Bring up the lockd process if it's not already up. 256 */ 257 int 258 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 259 { 260 struct svc_serv * serv; 261 int error = 0; 262 263 mutex_lock(&nlmsvc_mutex); 264 /* 265 * Check whether we're already up and running. 266 */ 267 if (nlmsvc_pid) { 268 if (proto) 269 error = make_socks(nlmsvc_serv, proto); 270 goto out; 271 } 272 273 /* 274 * Sanity check: if there's no pid, 275 * we should be the first user ... 276 */ 277 if (nlmsvc_users) 278 printk(KERN_WARNING 279 "lockd_up: no pid, %d users??\n", nlmsvc_users); 280 281 error = -ENOMEM; 282 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 283 if (!serv) { 284 printk(KERN_WARNING "lockd_up: create service failed\n"); 285 goto out; 286 } 287 288 if ((error = make_socks(serv, proto)) < 0) 289 goto destroy_and_out; 290 291 /* 292 * Create the kernel thread and wait for it to start. 293 */ 294 error = svc_create_thread(lockd, serv); 295 if (error) { 296 printk(KERN_WARNING 297 "lockd_up: create thread failed, error=%d\n", error); 298 goto destroy_and_out; 299 } 300 wait_for_completion(&lockd_start_done); 301 302 /* 303 * Note: svc_serv structures have an initial use count of 1, 304 * so we exit through here on both success and failure. 305 */ 306 destroy_and_out: 307 svc_destroy(serv); 308 out: 309 if (!error) 310 nlmsvc_users++; 311 mutex_unlock(&nlmsvc_mutex); 312 return error; 313 } 314 EXPORT_SYMBOL(lockd_up); 315 316 /* 317 * Decrement the user count and bring down lockd if we're the last. 318 */ 319 void 320 lockd_down(void) 321 { 322 static int warned; 323 324 mutex_lock(&nlmsvc_mutex); 325 if (nlmsvc_users) { 326 if (--nlmsvc_users) 327 goto out; 328 } else 329 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid); 330 331 if (!nlmsvc_pid) { 332 if (warned++ == 0) 333 printk(KERN_WARNING "lockd_down: no lockd running.\n"); 334 goto out; 335 } 336 warned = 0; 337 338 kill_proc(nlmsvc_pid, SIGKILL, 1); 339 /* 340 * Wait for the lockd process to exit, but since we're holding 341 * the lockd semaphore, we can't wait around forever ... 342 */ 343 clear_thread_flag(TIF_SIGPENDING); 344 interruptible_sleep_on_timeout(&lockd_exit, HZ); 345 if (nlmsvc_pid) { 346 printk(KERN_WARNING 347 "lockd_down: lockd failed to exit, clearing pid\n"); 348 nlmsvc_pid = 0; 349 } 350 spin_lock_irq(¤t->sighand->siglock); 351 recalc_sigpending(); 352 spin_unlock_irq(¤t->sighand->siglock); 353 out: 354 mutex_unlock(&nlmsvc_mutex); 355 } 356 EXPORT_SYMBOL(lockd_down); 357 358 /* 359 * Sysctl parameters (same as module parameters, different interface). 360 */ 361 362 static ctl_table nlm_sysctls[] = { 363 { 364 .ctl_name = CTL_UNNUMBERED, 365 .procname = "nlm_grace_period", 366 .data = &nlm_grace_period, 367 .maxlen = sizeof(unsigned long), 368 .mode = 0644, 369 .proc_handler = &proc_doulongvec_minmax, 370 .extra1 = (unsigned long *) &nlm_grace_period_min, 371 .extra2 = (unsigned long *) &nlm_grace_period_max, 372 }, 373 { 374 .ctl_name = CTL_UNNUMBERED, 375 .procname = "nlm_timeout", 376 .data = &nlm_timeout, 377 .maxlen = sizeof(unsigned long), 378 .mode = 0644, 379 .proc_handler = &proc_doulongvec_minmax, 380 .extra1 = (unsigned long *) &nlm_timeout_min, 381 .extra2 = (unsigned long *) &nlm_timeout_max, 382 }, 383 { 384 .ctl_name = CTL_UNNUMBERED, 385 .procname = "nlm_udpport", 386 .data = &nlm_udpport, 387 .maxlen = sizeof(int), 388 .mode = 0644, 389 .proc_handler = &proc_dointvec_minmax, 390 .extra1 = (int *) &nlm_port_min, 391 .extra2 = (int *) &nlm_port_max, 392 }, 393 { 394 .ctl_name = CTL_UNNUMBERED, 395 .procname = "nlm_tcpport", 396 .data = &nlm_tcpport, 397 .maxlen = sizeof(int), 398 .mode = 0644, 399 .proc_handler = &proc_dointvec_minmax, 400 .extra1 = (int *) &nlm_port_min, 401 .extra2 = (int *) &nlm_port_max, 402 }, 403 { 404 .ctl_name = CTL_UNNUMBERED, 405 .procname = "nsm_use_hostnames", 406 .data = &nsm_use_hostnames, 407 .maxlen = sizeof(int), 408 .mode = 0644, 409 .proc_handler = &proc_dointvec, 410 }, 411 { 412 .ctl_name = CTL_UNNUMBERED, 413 .procname = "nsm_local_state", 414 .data = &nsm_local_state, 415 .maxlen = sizeof(int), 416 .mode = 0644, 417 .proc_handler = &proc_dointvec, 418 }, 419 { .ctl_name = 0 } 420 }; 421 422 static ctl_table nlm_sysctl_dir[] = { 423 { 424 .ctl_name = CTL_UNNUMBERED, 425 .procname = "nfs", 426 .mode = 0555, 427 .child = nlm_sysctls, 428 }, 429 { .ctl_name = 0 } 430 }; 431 432 static ctl_table nlm_sysctl_root[] = { 433 { 434 .ctl_name = CTL_FS, 435 .procname = "fs", 436 .mode = 0555, 437 .child = nlm_sysctl_dir, 438 }, 439 { .ctl_name = 0 } 440 }; 441 442 /* 443 * Module (and sysfs) parameters. 444 */ 445 446 #define param_set_min_max(name, type, which_strtol, min, max) \ 447 static int param_set_##name(const char *val, struct kernel_param *kp) \ 448 { \ 449 char *endp; \ 450 __typeof__(type) num = which_strtol(val, &endp, 0); \ 451 if (endp == val || *endp || num < (min) || num > (max)) \ 452 return -EINVAL; \ 453 *((int *) kp->arg) = num; \ 454 return 0; \ 455 } 456 457 static inline int is_callback(u32 proc) 458 { 459 return proc == NLMPROC_GRANTED 460 || proc == NLMPROC_GRANTED_MSG 461 || proc == NLMPROC_TEST_RES 462 || proc == NLMPROC_LOCK_RES 463 || proc == NLMPROC_CANCEL_RES 464 || proc == NLMPROC_UNLOCK_RES 465 || proc == NLMPROC_NSM_NOTIFY; 466 } 467 468 469 static int lockd_authenticate(struct svc_rqst *rqstp) 470 { 471 rqstp->rq_client = NULL; 472 switch (rqstp->rq_authop->flavour) { 473 case RPC_AUTH_NULL: 474 case RPC_AUTH_UNIX: 475 if (rqstp->rq_proc == 0) 476 return SVC_OK; 477 if (is_callback(rqstp->rq_proc)) { 478 /* Leave it to individual procedures to 479 * call nlmsvc_lookup_host(rqstp) 480 */ 481 return SVC_OK; 482 } 483 return svc_set_client(rqstp); 484 } 485 return SVC_DENIED; 486 } 487 488 489 param_set_min_max(port, int, simple_strtol, 0, 65535) 490 param_set_min_max(grace_period, unsigned long, simple_strtoul, 491 nlm_grace_period_min, nlm_grace_period_max) 492 param_set_min_max(timeout, unsigned long, simple_strtoul, 493 nlm_timeout_min, nlm_timeout_max) 494 495 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 496 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 497 MODULE_LICENSE("GPL"); 498 499 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 500 &nlm_grace_period, 0644); 501 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 502 &nlm_timeout, 0644); 503 module_param_call(nlm_udpport, param_set_port, param_get_int, 504 &nlm_udpport, 0644); 505 module_param_call(nlm_tcpport, param_set_port, param_get_int, 506 &nlm_tcpport, 0644); 507 module_param(nsm_use_hostnames, bool, 0644); 508 509 /* 510 * Initialising and terminating the module. 511 */ 512 513 static int __init init_nlm(void) 514 { 515 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 516 return nlm_sysctl_table ? 0 : -ENOMEM; 517 } 518 519 static void __exit exit_nlm(void) 520 { 521 /* FIXME: delete all NLM clients */ 522 nlm_shutdown_hosts(); 523 unregister_sysctl_table(nlm_sysctl_table); 524 } 525 526 module_init(init_nlm); 527 module_exit(exit_nlm); 528 529 /* 530 * Define NLM program and procedures 531 */ 532 static struct svc_version nlmsvc_version1 = { 533 .vs_vers = 1, 534 .vs_nproc = 17, 535 .vs_proc = nlmsvc_procedures, 536 .vs_xdrsize = NLMSVC_XDRSIZE, 537 }; 538 static struct svc_version nlmsvc_version3 = { 539 .vs_vers = 3, 540 .vs_nproc = 24, 541 .vs_proc = nlmsvc_procedures, 542 .vs_xdrsize = NLMSVC_XDRSIZE, 543 }; 544 #ifdef CONFIG_LOCKD_V4 545 static struct svc_version nlmsvc_version4 = { 546 .vs_vers = 4, 547 .vs_nproc = 24, 548 .vs_proc = nlmsvc_procedures4, 549 .vs_xdrsize = NLMSVC_XDRSIZE, 550 }; 551 #endif 552 static struct svc_version * nlmsvc_version[] = { 553 [1] = &nlmsvc_version1, 554 [3] = &nlmsvc_version3, 555 #ifdef CONFIG_LOCKD_V4 556 [4] = &nlmsvc_version4, 557 #endif 558 }; 559 560 static struct svc_stat nlmsvc_stats; 561 562 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 563 static struct svc_program nlmsvc_program = { 564 .pg_prog = NLM_PROGRAM, /* program number */ 565 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 566 .pg_vers = nlmsvc_version, /* version table */ 567 .pg_name = "lockd", /* service name */ 568 .pg_class = "nfsd", /* share authentication with nfsd */ 569 .pg_stats = &nlmsvc_stats, /* stats table */ 570 .pg_authenticate = &lockd_authenticate /* export authentication */ 571 }; 572