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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
  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/kthread.h>
  29 #include <linux/freezer.h>
  30
  31 #include <linux/sunrpc/types.h>
  32 #include <linux/sunrpc/stats.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/svc.h>
  35 #include <linux/sunrpc/svcsock.h>
  36 #include <net/ip.h>
  37 #include <linux/lockd/lockd.h>
  38 #include <linux/lockd/sm_inter.h>
  39 #include <linux/nfs.h>
  40
  41 #define NLMDBG_FACILITY         NLMDBG_SVC
  42 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  43 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  44
  45 static struct svc_program       nlmsvc_program;
  46
  47 struct nlmsvc_binding *         nlmsvc_ops;
  48 EXPORT_SYMBOL(nlmsvc_ops);
  49
  50 static DEFINE_MUTEX(nlmsvc_mutex);
  51 static unsigned int             nlmsvc_users;
  52 static struct task_struct       *nlmsvc_task;
  53 static struct svc_rqst          *nlmsvc_rqst;
  54 int                             nlmsvc_grace_period;
  55 unsigned long                   nlmsvc_timeout;
  56
  57 /*
  58  * These can be set at insmod time (useful for NFS as root filesystem),
  59  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
  60  */
  61 static unsigned long            nlm_grace_period;
  62 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  63 static int                      nlm_udpport, nlm_tcpport;
  64 int                             nsm_use_hostnames = 0;
  65
  66 /*
  67  * Constants needed for the sysctl interface.
  68  */
  69 static const unsigned long      nlm_grace_period_min = 0;
  70 static const unsigned long      nlm_grace_period_max = 240;
  71 static const unsigned long      nlm_timeout_min = 3;
  72 static const unsigned long      nlm_timeout_max = 20;
  73 static const int                nlm_port_min = 0, nlm_port_max = 65535;
  74
  75 #ifdef CONFIG_SYSCTL
  76 static struct ctl_table_header * nlm_sysctl_table;
  77 #endif
  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 int
 115 lockd(void *vrqstp)
 116 {
 117         int             err = 0, preverr = 0;
 118         struct svc_rqst *rqstp = vrqstp;
 119         unsigned long grace_period_expire;
 120
 121         /* try_to_freeze() is called from svc_recv() */
 122         set_freezable();
 123
 124         /* Allow SIGKILL to tell lockd to drop all of its locks */
 125         allow_signal(SIGKILL);
 126
 127         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 128
 129         /*
 130          * FIXME: it would be nice if lockd didn't spend its entire life
 131          * running under the BKL. At the very least, it would be good to
 132          * have someone clarify what it's intended to protect here. I've
 133          * seen some handwavy posts about posix locking needing to be
 134          * done under the BKL, but it's far from clear.
 135          */
 136         lock_kernel();
 137
 138         if (!nlm_timeout)
 139                 nlm_timeout = LOCKD_DFLT_TIMEO;
 140         nlmsvc_timeout = nlm_timeout * HZ;
 141
 142         grace_period_expire = set_grace_period();
 143
 144         /*
 145          * The main request loop. We don't terminate until the last
 146          * NFS mount or NFS daemon has gone away.
 147          */
 148         while (!kthread_should_stop()) {
 149                 long timeout = MAX_SCHEDULE_TIMEOUT;
 150                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 151
 152                 if (signalled()) {
 153                         flush_signals(current);
 154                         if (nlmsvc_ops) {
 155                                 nlmsvc_invalidate_all();
 156                                 grace_period_expire = set_grace_period();
 157                         }
 158                         continue;
 159                 }
 160
 161                 /*
 162                  * Retry any blocked locks that have been notified by
 163                  * the VFS. Don't do this during grace period.
 164                  * (Theoretically, there shouldn't even be blocked locks
 165                  * during grace period).
 166                  */
 167                 if (!nlmsvc_grace_period) {
 168                         timeout = nlmsvc_retry_blocked();
 169                 } else if (time_before(grace_period_expire, jiffies))
 170                         clear_grace_period();
 171
 172                 /*
 173                  * Find a socket with data available and call its
 174                  * recvfrom routine.
 175                  */
 176                 err = svc_recv(rqstp, timeout);
 177                 if (err == -EAGAIN || err == -EINTR) {
 178                         preverr = err;
 179                         continue;
 180                 }
 181                 if (err < 0) {
 182                         if (err != preverr) {
 183                                 printk(KERN_WARNING "%s: unexpected error "
 184                                         "from svc_recv (%d)\n", __func__, err);
 185                                 preverr = err;
 186                         }
 187                         schedule_timeout_interruptible(HZ);
 188                         continue;
 189                 }
 190                 preverr = err;
 191
 192                 dprintk("lockd: request from %s\n",
 193                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 194
 195                 svc_process(rqstp);
 196         }
 197         flush_signals(current);
 198         if (nlmsvc_ops)
 199                 nlmsvc_invalidate_all();
 200         nlm_shutdown_hosts();
 201         unlock_kernel();
 202         return 0;
 203 }
 204
 205 /*
 206  * Make any sockets that are needed but not present.
 207  * If nlm_udpport or nlm_tcpport were set as module
 208  * options, make those sockets unconditionally
 209  */
 210 static int make_socks(struct svc_serv *serv, int proto)
 211 {
 212         static int warned;
 213         struct svc_xprt *xprt;
 214         int err = 0;
 215
 216         if (proto == IPPROTO_UDP || nlm_udpport) {
 217                 xprt = svc_find_xprt(serv, "udp", 0, 0);
 218                 if (!xprt)
 219                         err = svc_create_xprt(serv, "udp", nlm_udpport,
 220                                               SVC_SOCK_DEFAULTS);
 221                 else
 222                         svc_xprt_put(xprt);
 223         }
 224         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
 225                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
 226                 if (!xprt)
 227                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
 228                                               SVC_SOCK_DEFAULTS);
 229                 else
 230                         svc_xprt_put(xprt);
 231         }
 232         if (err >= 0) {
 233                 warned = 0;
 234                 err = 0;
 235         } else if (warned++ == 0)
 236                 printk(KERN_WARNING
 237                        "lockd_up: makesock failed, error=%d\n", err);
 238         return err;
 239 }
 240
 241 /*
 242  * Bring up the lockd process if it's not already up.
 243  */
 244 int
 245 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 246 {
 247         struct svc_serv *serv;
 248         int             error = 0;
 249
 250         mutex_lock(&nlmsvc_mutex);
 251         /*
 252          * Check whether we're already up and running.
 253          */
 254         if (nlmsvc_rqst) {
 255                 if (proto)
 256                         error = make_socks(nlmsvc_rqst->rq_server, proto);
 257                 goto out;
 258         }
 259
 260         /*
 261          * Sanity check: if there's no pid,
 262          * we should be the first user ...
 263          */
 264         if (nlmsvc_users)
 265                 printk(KERN_WARNING
 266                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 267
 268         error = -ENOMEM;
 269         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 270         if (!serv) {
 271                 printk(KERN_WARNING "lockd_up: create service failed\n");
 272                 goto out;
 273         }
 274
 275         if ((error = make_socks(serv, proto)) < 0)
 276                 goto destroy_and_out;
 277
 278         /*
 279          * Create the kernel thread and wait for it to start.
 280          */
 281         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
 282         if (IS_ERR(nlmsvc_rqst)) {
 283                 error = PTR_ERR(nlmsvc_rqst);
 284                 nlmsvc_rqst = NULL;
 285                 printk(KERN_WARNING
 286                         "lockd_up: svc_rqst allocation failed, error=%d\n",
 287                         error);
 288                 goto destroy_and_out;
 289         }
 290
 291         svc_sock_update_bufs(serv);
 292
 293         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
 294         if (IS_ERR(nlmsvc_task)) {
 295                 error = PTR_ERR(nlmsvc_task);
 296                 svc_exit_thread(nlmsvc_rqst);
 297                 nlmsvc_task = NULL;
 298                 nlmsvc_rqst = NULL;
 299                 printk(KERN_WARNING
 300                         "lockd_up: kthread_run failed, error=%d\n", error);
 301                 goto destroy_and_out;
 302         }
 303
 304         /*
 305          * Note: svc_serv structures have an initial use count of 1,
 306          * so we exit through here on both success and failure.
 307          */
 308 destroy_and_out:
 309         svc_destroy(serv);
 310 out:
 311         if (!error)
 312                 nlmsvc_users++;
 313         mutex_unlock(&nlmsvc_mutex);
 314         return error;
 315 }
 316 EXPORT_SYMBOL(lockd_up);
 317
 318 /*
 319  * Decrement the user count and bring down lockd if we're the last.
 320  */
 321 void
 322 lockd_down(void)
 323 {
 324         mutex_lock(&nlmsvc_mutex);
 325         if (nlmsvc_users) {
 326                 if (--nlmsvc_users)
 327                         goto out;
 328         } else {
 329                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
 330                         nlmsvc_task);
 331                 BUG();
 332         }
 333
 334         if (!nlmsvc_task) {
 335                 printk(KERN_ERR "lockd_down: no lockd running.\n");
 336                 BUG();
 337         }
 338         kthread_stop(nlmsvc_task);
 339         svc_exit_thread(nlmsvc_rqst);
 340         nlmsvc_task = NULL;
 341         nlmsvc_rqst = NULL;
 342 out:
 343         mutex_unlock(&nlmsvc_mutex);
 344 }
 345 EXPORT_SYMBOL(lockd_down);
 346
 347 #ifdef CONFIG_SYSCTL
 348
 349 /*
 350  * Sysctl parameters (same as module parameters, different interface).
 351  */
 352
 353 static ctl_table nlm_sysctls[] = {
 354         {
 355                 .ctl_name       = CTL_UNNUMBERED,
 356                 .procname       = "nlm_grace_period",
 357                 .data           = &nlm_grace_period,
 358                 .maxlen         = sizeof(unsigned long),
 359                 .mode           = 0644,
 360                 .proc_handler   = &proc_doulongvec_minmax,
 361                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 362                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 363         },
 364         {
 365                 .ctl_name       = CTL_UNNUMBERED,
 366                 .procname       = "nlm_timeout",
 367                 .data           = &nlm_timeout,
 368                 .maxlen         = sizeof(unsigned long),
 369                 .mode           = 0644,
 370                 .proc_handler   = &proc_doulongvec_minmax,
 371                 .extra1         = (unsigned long *) &nlm_timeout_min,
 372                 .extra2         = (unsigned long *) &nlm_timeout_max,
 373         },
 374         {
 375                 .ctl_name       = CTL_UNNUMBERED,
 376                 .procname       = "nlm_udpport",
 377                 .data           = &nlm_udpport,
 378                 .maxlen         = sizeof(int),
 379                 .mode           = 0644,
 380                 .proc_handler   = &proc_dointvec_minmax,
 381                 .extra1         = (int *) &nlm_port_min,
 382                 .extra2         = (int *) &nlm_port_max,
 383         },
 384         {
 385                 .ctl_name       = CTL_UNNUMBERED,
 386                 .procname       = "nlm_tcpport",
 387                 .data           = &nlm_tcpport,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dointvec_minmax,
 391                 .extra1         = (int *) &nlm_port_min,
 392                 .extra2         = (int *) &nlm_port_max,
 393         },
 394         {
 395                 .ctl_name       = CTL_UNNUMBERED,
 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                 .ctl_name       = CTL_UNNUMBERED,
 404                 .procname       = "nsm_local_state",
 405                 .data           = &nsm_local_state,
 406                 .maxlen         = sizeof(int),
 407                 .mode           = 0644,
 408                 .proc_handler   = &proc_dointvec,
 409         },
 410         { .ctl_name = 0 }
 411 };
 412
 413 static ctl_table nlm_sysctl_dir[] = {
 414         {
 415                 .ctl_name       = CTL_UNNUMBERED,
 416                 .procname       = "nfs",
 417                 .mode           = 0555,
 418                 .child          = nlm_sysctls,
 419         },
 420         { .ctl_name = 0 }
 421 };
 422
 423 static ctl_table nlm_sysctl_root[] = {
 424         {
 425                 .ctl_name       = CTL_FS,
 426                 .procname       = "fs",
 427                 .mode           = 0555,
 428                 .child          = nlm_sysctl_dir,
 429         },
 430         { .ctl_name = 0 }
 431 };
 432
 433 #endif  /* CONFIG_SYSCTL */
 434
 435 /*
 436  * Module (and sysfs) parameters.
 437  */
 438
 439 #define param_set_min_max(name, type, which_strtol, min, max)           \
 440 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 441 {                                                                       \
 442         char *endp;                                                     \
 443         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 444         if (endp == val || *endp || num < (min) || num > (max))         \
 445                 return -EINVAL;                                         \
 446         *((int *) kp->arg) = num;                                       \
 447         return 0;                                                       \
 448 }
 449
 450 static inline int is_callback(u32 proc)
 451 {
 452         return proc == NLMPROC_GRANTED
 453                 || proc == NLMPROC_GRANTED_MSG
 454                 || proc == NLMPROC_TEST_RES
 455                 || proc == NLMPROC_LOCK_RES
 456                 || proc == NLMPROC_CANCEL_RES
 457                 || proc == NLMPROC_UNLOCK_RES
 458                 || proc == NLMPROC_NSM_NOTIFY;
 459 }
 460
 461
 462 static int lockd_authenticate(struct svc_rqst *rqstp)
 463 {
 464         rqstp->rq_client = NULL;
 465         switch (rqstp->rq_authop->flavour) {
 466                 case RPC_AUTH_NULL:
 467                 case RPC_AUTH_UNIX:
 468                         if (rqstp->rq_proc == 0)
 469                                 return SVC_OK;
 470                         if (is_callback(rqstp->rq_proc)) {
 471                                 /* Leave it to individual procedures to
 472                                  * call nlmsvc_lookup_host(rqstp)
 473                                  */
 474                                 return SVC_OK;
 475                         }
 476                         return svc_set_client(rqstp);
 477         }
 478         return SVC_DENIED;
 479 }
 480
 481
 482 param_set_min_max(port, int, simple_strtol, 0, 65535)
 483 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 484                   nlm_grace_period_min, nlm_grace_period_max)
 485 param_set_min_max(timeout, unsigned long, simple_strtoul,
 486                   nlm_timeout_min, nlm_timeout_max)
 487
 488 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 489 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 490 MODULE_LICENSE("GPL");
 491
 492 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 493                   &nlm_grace_period, 0644);
 494 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 495                   &nlm_timeout, 0644);
 496 module_param_call(nlm_udpport, param_set_port, param_get_int,
 497                   &nlm_udpport, 0644);
 498 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 499                   &nlm_tcpport, 0644);
 500 module_param(nsm_use_hostnames, bool, 0644);
 501
 502 /*
 503  * Initialising and terminating the module.
 504  */
 505
 506 static int __init init_nlm(void)
 507 {
 508 #ifdef CONFIG_SYSCTL
 509         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 510         return nlm_sysctl_table ? 0 : -ENOMEM;
 511 #else
 512         return 0;
 513 #endif
 514 }
 515
 516 static void __exit exit_nlm(void)
 517 {
 518         /* FIXME: delete all NLM clients */
 519         nlm_shutdown_hosts();
 520 #ifdef CONFIG_SYSCTL
 521         unregister_sysctl_table(nlm_sysctl_table);
 522 #endif
 523 }
 524
 525 module_init(init_nlm);
 526 module_exit(exit_nlm);
 527
 528 /*
 529  * Define NLM program and procedures
 530  */
 531 static struct svc_version       nlmsvc_version1 = {
 532                 .vs_vers        = 1,
 533                 .vs_nproc       = 17,
 534                 .vs_proc        = nlmsvc_procedures,
 535                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 536 };
 537 static struct svc_version       nlmsvc_version3 = {
 538                 .vs_vers        = 3,
 539                 .vs_nproc       = 24,
 540                 .vs_proc        = nlmsvc_procedures,
 541                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 542 };
 543 #ifdef CONFIG_LOCKD_V4
 544 static struct svc_version       nlmsvc_version4 = {
 545                 .vs_vers        = 4,
 546                 .vs_nproc       = 24,
 547                 .vs_proc        = nlmsvc_procedures4,
 548                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 549 };
 550 #endif
 551 static struct svc_version *     nlmsvc_version[] = {
 552         [1] = &nlmsvc_version1,
 553         [3] = &nlmsvc_version3,
 554 #ifdef CONFIG_LOCKD_V4
 555         [4] = &nlmsvc_version4,
 556 #endif
 557 };
 558
 559 static struct svc_stat          nlmsvc_stats;
 560
 561 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 562 static struct svc_program       nlmsvc_program = {
 563         .pg_prog                = NLM_PROGRAM,          /* program number */
 564         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 565         .pg_vers                = nlmsvc_version,       /* version table */
 566         .pg_name                = "lockd",              /* service name */
 567         .pg_class               = "nfsd",               /* share authentication with nfsd */
 568         .pg_stats               = &nlmsvc_stats,        /* stats table */
 569         .pg_authenticate = &lockd_authenticate  /* export authentication */
 570 };