svc.c 14 KB

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  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. #include <linux/module.h>
  15. #include <linux/init.h>
  16. #include <linux/sysctl.h>
  17. #include <linux/moduleparam.h>
  18. #include <linux/sched.h>
  19. #include <linux/errno.h>
  20. #include <linux/in.h>
  21. #include <linux/uio.h>
  22. #include <linux/slab.h>
  23. #include <linux/smp.h>
  24. #include <linux/smp_lock.h>
  25. #include <linux/mutex.h>
  26. #include <linux/sunrpc/types.h>
  27. #include <linux/sunrpc/stats.h>
  28. #include <linux/sunrpc/clnt.h>
  29. #include <linux/sunrpc/svc.h>
  30. #include <linux/sunrpc/svcsock.h>
  31. #include <net/ip.h>
  32. #include <linux/lockd/lockd.h>
  33. #include <linux/lockd/sm_inter.h>
  34. #include <linux/nfs.h>
  35. #define NLMDBG_FACILITY NLMDBG_SVC
  36. #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
  37. #define ALLOWED_SIGS (sigmask(SIGKILL))
  38. static struct svc_program nlmsvc_program;
  39. struct nlmsvc_binding * nlmsvc_ops;
  40. EXPORT_SYMBOL(nlmsvc_ops);
  41. static DEFINE_MUTEX(nlmsvc_mutex);
  42. static unsigned int nlmsvc_users;
  43. static pid_t nlmsvc_pid;
  44. static struct svc_serv *nlmsvc_serv;
  45. int nlmsvc_grace_period;
  46. unsigned long nlmsvc_timeout;
  47. static DECLARE_COMPLETION(lockd_start_done);
  48. static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
  49. /*
  50. * These can be set at insmod time (useful for NFS as root filesystem),
  51. * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
  52. */
  53. static unsigned long nlm_grace_period;
  54. static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
  55. static int nlm_udpport, nlm_tcpport;
  56. int nsm_use_hostnames = 0;
  57. /*
  58. * Constants needed for the sysctl interface.
  59. */
  60. static const unsigned long nlm_grace_period_min = 0;
  61. static const unsigned long nlm_grace_period_max = 240;
  62. static const unsigned long nlm_timeout_min = 3;
  63. static const unsigned long nlm_timeout_max = 20;
  64. static const int nlm_port_min = 0, nlm_port_max = 65535;
  65. static struct ctl_table_header * nlm_sysctl_table;
  66. static unsigned long set_grace_period(void)
  67. {
  68. unsigned long grace_period;
  69. /* Note: nlm_timeout should always be nonzero */
  70. if (nlm_grace_period)
  71. grace_period = ((nlm_grace_period + nlm_timeout - 1)
  72. / nlm_timeout) * nlm_timeout * HZ;
  73. else
  74. grace_period = nlm_timeout * 5 * HZ;
  75. nlmsvc_grace_period = 1;
  76. return grace_period + jiffies;
  77. }
  78. static inline void clear_grace_period(void)
  79. {
  80. nlmsvc_grace_period = 0;
  81. }
  82. /*
  83. * This is the lockd kernel thread
  84. */
  85. static void
  86. lockd(struct svc_rqst *rqstp)
  87. {
  88. int err = 0;
  89. unsigned long grace_period_expire;
  90. /* Lock module and set up kernel thread */
  91. /* lockd_up is waiting for us to startup, so will
  92. * be holding a reference to this module, so it
  93. * is safe to just claim another reference
  94. */
  95. __module_get(THIS_MODULE);
  96. lock_kernel();
  97. /*
  98. * Let our maker know we're running.
  99. */
  100. nlmsvc_pid = current->pid;
  101. nlmsvc_serv = rqstp->rq_server;
  102. complete(&lockd_start_done);
  103. daemonize("lockd");
  104. /* Process request with signals blocked, but allow SIGKILL. */
  105. allow_signal(SIGKILL);
  106. /* kick rpciod */
  107. rpciod_up();
  108. dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
  109. if (!nlm_timeout)
  110. nlm_timeout = LOCKD_DFLT_TIMEO;
  111. nlmsvc_timeout = nlm_timeout * HZ;
  112. grace_period_expire = set_grace_period();
  113. /*
  114. * The main request loop. We don't terminate until the last
  115. * NFS mount or NFS daemon has gone away, and we've been sent a
  116. * signal, or else another process has taken over our job.
  117. */
  118. while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
  119. long timeout = MAX_SCHEDULE_TIMEOUT;
  120. char buf[RPC_MAX_ADDRBUFLEN];
  121. if (signalled()) {
  122. flush_signals(current);
  123. if (nlmsvc_ops) {
  124. nlmsvc_invalidate_all();
  125. grace_period_expire = set_grace_period();
  126. }
  127. }
  128. /*
  129. * Retry any blocked locks that have been notified by
  130. * the VFS. Don't do this during grace period.
  131. * (Theoretically, there shouldn't even be blocked locks
  132. * during grace period).
  133. */
  134. if (!nlmsvc_grace_period) {
  135. timeout = nlmsvc_retry_blocked();
  136. } else if (time_before(grace_period_expire, jiffies))
  137. clear_grace_period();
  138. /*
  139. * Find a socket with data available and call its
  140. * recvfrom routine.
  141. */
  142. err = svc_recv(rqstp, timeout);
  143. if (err == -EAGAIN || err == -EINTR)
  144. continue;
  145. if (err < 0) {
  146. printk(KERN_WARNING
  147. "lockd: terminating on error %d\n",
  148. -err);
  149. break;
  150. }
  151. dprintk("lockd: request from %s\n",
  152. svc_print_addr(rqstp, buf, sizeof(buf)));
  153. svc_process(rqstp);
  154. }
  155. flush_signals(current);
  156. /*
  157. * Check whether there's a new lockd process before
  158. * shutting down the hosts and clearing the slot.
  159. */
  160. if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
  161. if (nlmsvc_ops)
  162. nlmsvc_invalidate_all();
  163. nlm_shutdown_hosts();
  164. nlmsvc_pid = 0;
  165. nlmsvc_serv = NULL;
  166. } else
  167. printk(KERN_DEBUG
  168. "lockd: new process, skipping host shutdown\n");
  169. wake_up(&lockd_exit);
  170. /* Exit the RPC thread */
  171. svc_exit_thread(rqstp);
  172. /* release rpciod */
  173. rpciod_down();
  174. /* Release module */
  175. unlock_kernel();
  176. module_put_and_exit(0);
  177. }
  178. static int find_socket(struct svc_serv *serv, int proto)
  179. {
  180. struct svc_sock *svsk;
  181. int found = 0;
  182. list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
  183. if (svsk->sk_sk->sk_protocol == proto) {
  184. found = 1;
  185. break;
  186. }
  187. return found;
  188. }
  189. /*
  190. * Make any sockets that are needed but not present.
  191. * If nlm_udpport or nlm_tcpport were set as module
  192. * options, make those sockets unconditionally
  193. */
  194. static int make_socks(struct svc_serv *serv, int proto)
  195. {
  196. static int warned;
  197. int err = 0;
  198. if (proto == IPPROTO_UDP || nlm_udpport)
  199. if (!find_socket(serv, IPPROTO_UDP))
  200. err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport,
  201. SVC_SOCK_DEFAULTS);
  202. if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
  203. if (!find_socket(serv, IPPROTO_TCP))
  204. err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport,
  205. SVC_SOCK_DEFAULTS);
  206. if (err >= 0) {
  207. warned = 0;
  208. err = 0;
  209. } else if (warned++ == 0)
  210. printk(KERN_WARNING
  211. "lockd_up: makesock failed, error=%d\n", err);
  212. return err;
  213. }
  214. /*
  215. * Bring up the lockd process if it's not already up.
  216. */
  217. int
  218. lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
  219. {
  220. struct svc_serv * serv;
  221. int error = 0;
  222. mutex_lock(&nlmsvc_mutex);
  223. /*
  224. * Check whether we're already up and running.
  225. */
  226. if (nlmsvc_pid) {
  227. if (proto)
  228. error = make_socks(nlmsvc_serv, proto);
  229. goto out;
  230. }
  231. /*
  232. * Sanity check: if there's no pid,
  233. * we should be the first user ...
  234. */
  235. if (nlmsvc_users)
  236. printk(KERN_WARNING
  237. "lockd_up: no pid, %d users??\n", nlmsvc_users);
  238. error = -ENOMEM;
  239. serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
  240. if (!serv) {
  241. printk(KERN_WARNING "lockd_up: create service failed\n");
  242. goto out;
  243. }
  244. if ((error = make_socks(serv, proto)) < 0)
  245. goto destroy_and_out;
  246. /*
  247. * Create the kernel thread and wait for it to start.
  248. */
  249. error = svc_create_thread(lockd, serv);
  250. if (error) {
  251. printk(KERN_WARNING
  252. "lockd_up: create thread failed, error=%d\n", error);
  253. goto destroy_and_out;
  254. }
  255. wait_for_completion(&lockd_start_done);
  256. /*
  257. * Note: svc_serv structures have an initial use count of 1,
  258. * so we exit through here on both success and failure.
  259. */
  260. destroy_and_out:
  261. svc_destroy(serv);
  262. out:
  263. if (!error)
  264. nlmsvc_users++;
  265. mutex_unlock(&nlmsvc_mutex);
  266. return error;
  267. }
  268. EXPORT_SYMBOL(lockd_up);
  269. /*
  270. * Decrement the user count and bring down lockd if we're the last.
  271. */
  272. void
  273. lockd_down(void)
  274. {
  275. static int warned;
  276. mutex_lock(&nlmsvc_mutex);
  277. if (nlmsvc_users) {
  278. if (--nlmsvc_users)
  279. goto out;
  280. } else
  281. printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
  282. if (!nlmsvc_pid) {
  283. if (warned++ == 0)
  284. printk(KERN_WARNING "lockd_down: no lockd running.\n");
  285. goto out;
  286. }
  287. warned = 0;
  288. kill_proc(nlmsvc_pid, SIGKILL, 1);
  289. /*
  290. * Wait for the lockd process to exit, but since we're holding
  291. * the lockd semaphore, we can't wait around forever ...
  292. */
  293. clear_thread_flag(TIF_SIGPENDING);
  294. interruptible_sleep_on_timeout(&lockd_exit, HZ);
  295. if (nlmsvc_pid) {
  296. printk(KERN_WARNING
  297. "lockd_down: lockd failed to exit, clearing pid\n");
  298. nlmsvc_pid = 0;
  299. }
  300. spin_lock_irq(&current->sighand->siglock);
  301. recalc_sigpending();
  302. spin_unlock_irq(&current->sighand->siglock);
  303. out:
  304. mutex_unlock(&nlmsvc_mutex);
  305. }
  306. EXPORT_SYMBOL(lockd_down);
  307. /*
  308. * Sysctl parameters (same as module parameters, different interface).
  309. */
  310. static ctl_table nlm_sysctls[] = {
  311. {
  312. .ctl_name = CTL_UNNUMBERED,
  313. .procname = "nlm_grace_period",
  314. .data = &nlm_grace_period,
  315. .maxlen = sizeof(unsigned long),
  316. .mode = 0644,
  317. .proc_handler = &proc_doulongvec_minmax,
  318. .extra1 = (unsigned long *) &nlm_grace_period_min,
  319. .extra2 = (unsigned long *) &nlm_grace_period_max,
  320. },
  321. {
  322. .ctl_name = CTL_UNNUMBERED,
  323. .procname = "nlm_timeout",
  324. .data = &nlm_timeout,
  325. .maxlen = sizeof(unsigned long),
  326. .mode = 0644,
  327. .proc_handler = &proc_doulongvec_minmax,
  328. .extra1 = (unsigned long *) &nlm_timeout_min,
  329. .extra2 = (unsigned long *) &nlm_timeout_max,
  330. },
  331. {
  332. .ctl_name = CTL_UNNUMBERED,
  333. .procname = "nlm_udpport",
  334. .data = &nlm_udpport,
  335. .maxlen = sizeof(int),
  336. .mode = 0644,
  337. .proc_handler = &proc_dointvec_minmax,
  338. .extra1 = (int *) &nlm_port_min,
  339. .extra2 = (int *) &nlm_port_max,
  340. },
  341. {
  342. .ctl_name = CTL_UNNUMBERED,
  343. .procname = "nlm_tcpport",
  344. .data = &nlm_tcpport,
  345. .maxlen = sizeof(int),
  346. .mode = 0644,
  347. .proc_handler = &proc_dointvec_minmax,
  348. .extra1 = (int *) &nlm_port_min,
  349. .extra2 = (int *) &nlm_port_max,
  350. },
  351. {
  352. .ctl_name = CTL_UNNUMBERED,
  353. .procname = "nsm_use_hostnames",
  354. .data = &nsm_use_hostnames,
  355. .maxlen = sizeof(int),
  356. .mode = 0644,
  357. .proc_handler = &proc_dointvec,
  358. },
  359. {
  360. .ctl_name = CTL_UNNUMBERED,
  361. .procname = "nsm_local_state",
  362. .data = &nsm_local_state,
  363. .maxlen = sizeof(int),
  364. .mode = 0644,
  365. .proc_handler = &proc_dointvec,
  366. },
  367. { .ctl_name = 0 }
  368. };
  369. static ctl_table nlm_sysctl_dir[] = {
  370. {
  371. .ctl_name = CTL_UNNUMBERED,
  372. .procname = "nfs",
  373. .mode = 0555,
  374. .child = nlm_sysctls,
  375. },
  376. { .ctl_name = 0 }
  377. };
  378. static ctl_table nlm_sysctl_root[] = {
  379. {
  380. .ctl_name = CTL_FS,
  381. .procname = "fs",
  382. .mode = 0555,
  383. .child = nlm_sysctl_dir,
  384. },
  385. { .ctl_name = 0 }
  386. };
  387. /*
  388. * Module (and sysfs) parameters.
  389. */
  390. #define param_set_min_max(name, type, which_strtol, min, max) \
  391. static int param_set_##name(const char *val, struct kernel_param *kp) \
  392. { \
  393. char *endp; \
  394. __typeof__(type) num = which_strtol(val, &endp, 0); \
  395. if (endp == val || *endp || num < (min) || num > (max)) \
  396. return -EINVAL; \
  397. *((int *) kp->arg) = num; \
  398. return 0; \
  399. }
  400. static inline int is_callback(u32 proc)
  401. {
  402. return proc == NLMPROC_GRANTED
  403. || proc == NLMPROC_GRANTED_MSG
  404. || proc == NLMPROC_TEST_RES
  405. || proc == NLMPROC_LOCK_RES
  406. || proc == NLMPROC_CANCEL_RES
  407. || proc == NLMPROC_UNLOCK_RES
  408. || proc == NLMPROC_NSM_NOTIFY;
  409. }
  410. static int lockd_authenticate(struct svc_rqst *rqstp)
  411. {
  412. rqstp->rq_client = NULL;
  413. switch (rqstp->rq_authop->flavour) {
  414. case RPC_AUTH_NULL:
  415. case RPC_AUTH_UNIX:
  416. if (rqstp->rq_proc == 0)
  417. return SVC_OK;
  418. if (is_callback(rqstp->rq_proc)) {
  419. /* Leave it to individual procedures to
  420. * call nlmsvc_lookup_host(rqstp)
  421. */
  422. return SVC_OK;
  423. }
  424. return svc_set_client(rqstp);
  425. }
  426. return SVC_DENIED;
  427. }
  428. param_set_min_max(port, int, simple_strtol, 0, 65535)
  429. param_set_min_max(grace_period, unsigned long, simple_strtoul,
  430. nlm_grace_period_min, nlm_grace_period_max)
  431. param_set_min_max(timeout, unsigned long, simple_strtoul,
  432. nlm_timeout_min, nlm_timeout_max)
  433. MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
  434. MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
  435. MODULE_LICENSE("GPL");
  436. module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
  437. &nlm_grace_period, 0644);
  438. module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
  439. &nlm_timeout, 0644);
  440. module_param_call(nlm_udpport, param_set_port, param_get_int,
  441. &nlm_udpport, 0644);
  442. module_param_call(nlm_tcpport, param_set_port, param_get_int,
  443. &nlm_tcpport, 0644);
  444. module_param(nsm_use_hostnames, bool, 0644);
  445. /*
  446. * Initialising and terminating the module.
  447. */
  448. static int __init init_nlm(void)
  449. {
  450. nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
  451. return nlm_sysctl_table ? 0 : -ENOMEM;
  452. }
  453. static void __exit exit_nlm(void)
  454. {
  455. /* FIXME: delete all NLM clients */
  456. nlm_shutdown_hosts();
  457. unregister_sysctl_table(nlm_sysctl_table);
  458. }
  459. module_init(init_nlm);
  460. module_exit(exit_nlm);
  461. /*
  462. * Define NLM program and procedures
  463. */
  464. static struct svc_version nlmsvc_version1 = {
  465. .vs_vers = 1,
  466. .vs_nproc = 17,
  467. .vs_proc = nlmsvc_procedures,
  468. .vs_xdrsize = NLMSVC_XDRSIZE,
  469. };
  470. static struct svc_version nlmsvc_version3 = {
  471. .vs_vers = 3,
  472. .vs_nproc = 24,
  473. .vs_proc = nlmsvc_procedures,
  474. .vs_xdrsize = NLMSVC_XDRSIZE,
  475. };
  476. #ifdef CONFIG_LOCKD_V4
  477. static struct svc_version nlmsvc_version4 = {
  478. .vs_vers = 4,
  479. .vs_nproc = 24,
  480. .vs_proc = nlmsvc_procedures4,
  481. .vs_xdrsize = NLMSVC_XDRSIZE,
  482. };
  483. #endif
  484. static struct svc_version * nlmsvc_version[] = {
  485. [1] = &nlmsvc_version1,
  486. [3] = &nlmsvc_version3,
  487. #ifdef CONFIG_LOCKD_V4
  488. [4] = &nlmsvc_version4,
  489. #endif
  490. };
  491. static struct svc_stat nlmsvc_stats;
  492. #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
  493. static struct svc_program nlmsvc_program = {
  494. .pg_prog = NLM_PROGRAM, /* program number */
  495. .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
  496. .pg_vers = nlmsvc_version, /* version table */
  497. .pg_name = "lockd", /* service name */
  498. .pg_class = "nfsd", /* share authentication with nfsd */
  499. .pg_stats = &nlmsvc_stats, /* stats table */
  500. .pg_authenticate = &lockd_authenticate /* export authentication */
  501. };