linux/fs/lockd/svc.c
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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/smp.h>
  25#include <linux/mutex.h>
  26#include <linux/kthread.h>
  27#include <linux/freezer.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/nfs.h>
  37
  38#include "netns.h"
  39
  40#define NLMDBG_FACILITY         NLMDBG_SVC
  41#define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  42#define ALLOWED_SIGS            (sigmask(SIGKILL))
  43
  44static struct svc_program       nlmsvc_program;
  45
  46struct nlmsvc_binding *         nlmsvc_ops;
  47EXPORT_SYMBOL_GPL(nlmsvc_ops);
  48
  49static DEFINE_MUTEX(nlmsvc_mutex);
  50static unsigned int             nlmsvc_users;
  51static struct task_struct       *nlmsvc_task;
  52static struct svc_rqst          *nlmsvc_rqst;
  53unsigned long                   nlmsvc_timeout;
  54
  55int lockd_net_id;
  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 */
  61static unsigned long            nlm_grace_period;
  62static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  63static int                      nlm_udpport, nlm_tcpport;
  64
  65/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
  66static unsigned int             nlm_max_connections = 1024;
  67
  68/*
  69 * Constants needed for the sysctl interface.
  70 */
  71static const unsigned long      nlm_grace_period_min = 0;
  72static const unsigned long      nlm_grace_period_max = 240;
  73static const unsigned long      nlm_timeout_min = 3;
  74static const unsigned long      nlm_timeout_max = 20;
  75static const int                nlm_port_min = 0, nlm_port_max = 65535;
  76
  77#ifdef CONFIG_SYSCTL
  78static struct ctl_table_header * nlm_sysctl_table;
  79#endif
  80
  81static unsigned long get_lockd_grace_period(void)
  82{
  83        /* Note: nlm_timeout should always be nonzero */
  84        if (nlm_grace_period)
  85                return roundup(nlm_grace_period, nlm_timeout) * HZ;
  86        else
  87                return nlm_timeout * 5 * HZ;
  88}
  89
  90static void grace_ender(struct work_struct *grace)
  91{
  92        struct delayed_work *dwork = container_of(grace, struct delayed_work,
  93                                                  work);
  94        struct lockd_net *ln = container_of(dwork, struct lockd_net,
  95                                            grace_period_end);
  96
  97        locks_end_grace(&ln->lockd_manager);
  98}
  99
 100static void set_grace_period(struct net *net)
 101{
 102        unsigned long grace_period = get_lockd_grace_period();
 103        struct lockd_net *ln = net_generic(net, lockd_net_id);
 104
 105        locks_start_grace(net, &ln->lockd_manager);
 106        cancel_delayed_work_sync(&ln->grace_period_end);
 107        schedule_delayed_work(&ln->grace_period_end, grace_period);
 108}
 109
 110static void restart_grace(void)
 111{
 112        if (nlmsvc_ops) {
 113                struct net *net = &init_net;
 114                struct lockd_net *ln = net_generic(net, lockd_net_id);
 115
 116                cancel_delayed_work_sync(&ln->grace_period_end);
 117                locks_end_grace(&ln->lockd_manager);
 118                nlmsvc_invalidate_all();
 119                set_grace_period(net);
 120        }
 121}
 122
 123/*
 124 * This is the lockd kernel thread
 125 */
 126static int
 127lockd(void *vrqstp)
 128{
 129        int             err = 0;
 130        struct svc_rqst *rqstp = vrqstp;
 131
 132        /* try_to_freeze() is called from svc_recv() */
 133        set_freezable();
 134
 135        /* Allow SIGKILL to tell lockd to drop all of its locks */
 136        allow_signal(SIGKILL);
 137
 138        dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 139
 140        if (!nlm_timeout)
 141                nlm_timeout = LOCKD_DFLT_TIMEO;
 142        nlmsvc_timeout = nlm_timeout * HZ;
 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                /* update sv_maxconn if it has changed */
 153                rqstp->rq_server->sv_maxconn = nlm_max_connections;
 154
 155                if (signalled()) {
 156                        flush_signals(current);
 157                        restart_grace();
 158                        continue;
 159                }
 160
 161                timeout = nlmsvc_retry_blocked();
 162
 163                /*
 164                 * Find a socket with data available and call its
 165                 * recvfrom routine.
 166                 */
 167                err = svc_recv(rqstp, timeout);
 168                if (err == -EAGAIN || err == -EINTR)
 169                        continue;
 170                dprintk("lockd: request from %s\n",
 171                                svc_print_addr(rqstp, buf, sizeof(buf)));
 172
 173                svc_process(rqstp);
 174        }
 175        flush_signals(current);
 176        if (nlmsvc_ops)
 177                nlmsvc_invalidate_all();
 178        nlm_shutdown_hosts();
 179        return 0;
 180}
 181
 182static int create_lockd_listener(struct svc_serv *serv, const char *name,
 183                                 struct net *net, const int family,
 184                                 const unsigned short port)
 185{
 186        struct svc_xprt *xprt;
 187
 188        xprt = svc_find_xprt(serv, name, net, family, 0);
 189        if (xprt == NULL)
 190                return svc_create_xprt(serv, name, net, family, port,
 191                                                SVC_SOCK_DEFAULTS);
 192        svc_xprt_put(xprt);
 193        return 0;
 194}
 195
 196static int create_lockd_family(struct svc_serv *serv, struct net *net,
 197                               const int family)
 198{
 199        int err;
 200
 201        err = create_lockd_listener(serv, "udp", net, family, nlm_udpport);
 202        if (err < 0)
 203                return err;
 204
 205        return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport);
 206}
 207
 208/*
 209 * Ensure there are active UDP and TCP listeners for lockd.
 210 *
 211 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
 212 * local services (such as rpc.statd) still require UDP, and
 213 * some NFS servers do not yet support NLM over TCP.
 214 *
 215 * Returns zero if all listeners are available; otherwise a
 216 * negative errno value is returned.
 217 */
 218static int make_socks(struct svc_serv *serv, struct net *net)
 219{
 220        static int warned;
 221        int err;
 222
 223        err = create_lockd_family(serv, net, PF_INET);
 224        if (err < 0)
 225                goto out_err;
 226
 227        err = create_lockd_family(serv, net, PF_INET6);
 228        if (err < 0 && err != -EAFNOSUPPORT)
 229                goto out_err;
 230
 231        warned = 0;
 232        return 0;
 233
 234out_err:
 235        if (warned++ == 0)
 236                printk(KERN_WARNING
 237                        "lockd_up: makesock failed, error=%d\n", err);
 238        return err;
 239}
 240
 241static int lockd_up_net(struct svc_serv *serv, struct net *net)
 242{
 243        struct lockd_net *ln = net_generic(net, lockd_net_id);
 244        int error;
 245
 246        if (ln->nlmsvc_users++)
 247                return 0;
 248
 249        error = svc_bind(serv, net);
 250        if (error)
 251                goto err_bind;
 252
 253        error = make_socks(serv, net);
 254        if (error < 0)
 255                goto err_socks;
 256        set_grace_period(net);
 257        dprintk("lockd_up_net: per-net data created; net=%p\n", net);
 258        return 0;
 259
 260err_socks:
 261        svc_rpcb_cleanup(serv, net);
 262err_bind:
 263        ln->nlmsvc_users--;
 264        return error;
 265}
 266
 267static void lockd_down_net(struct svc_serv *serv, struct net *net)
 268{
 269        struct lockd_net *ln = net_generic(net, lockd_net_id);
 270
 271        if (ln->nlmsvc_users) {
 272                if (--ln->nlmsvc_users == 0) {
 273                        nlm_shutdown_hosts_net(net);
 274                        cancel_delayed_work_sync(&ln->grace_period_end);
 275                        locks_end_grace(&ln->lockd_manager);
 276                        svc_shutdown_net(serv, net);
 277                        dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net);
 278                }
 279        } else {
 280                printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n",
 281                                nlmsvc_task, net);
 282                BUG();
 283        }
 284}
 285
 286static int lockd_start_svc(struct svc_serv *serv)
 287{
 288        int error;
 289
 290        if (nlmsvc_rqst)
 291                return 0;
 292
 293        /*
 294         * Create the kernel thread and wait for it to start.
 295         */
 296        nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
 297        if (IS_ERR(nlmsvc_rqst)) {
 298                error = PTR_ERR(nlmsvc_rqst);
 299                printk(KERN_WARNING
 300                        "lockd_up: svc_rqst allocation failed, error=%d\n",
 301                        error);
 302                goto out_rqst;
 303        }
 304
 305        svc_sock_update_bufs(serv);
 306        serv->sv_maxconn = nlm_max_connections;
 307
 308        nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
 309        if (IS_ERR(nlmsvc_task)) {
 310                error = PTR_ERR(nlmsvc_task);
 311                printk(KERN_WARNING
 312                        "lockd_up: kthread_run failed, error=%d\n", error);
 313                goto out_task;
 314        }
 315        dprintk("lockd_up: service started\n");
 316        return 0;
 317
 318out_task:
 319        svc_exit_thread(nlmsvc_rqst);
 320        nlmsvc_task = NULL;
 321out_rqst:
 322        nlmsvc_rqst = NULL;
 323        return error;
 324}
 325
 326static struct svc_serv *lockd_create_svc(void)
 327{
 328        struct svc_serv *serv;
 329
 330        /*
 331         * Check whether we're already up and running.
 332         */
 333        if (nlmsvc_rqst) {
 334                /*
 335                 * Note: increase service usage, because later in case of error
 336                 * svc_destroy() will be called.
 337                 */
 338                svc_get(nlmsvc_rqst->rq_server);
 339                return nlmsvc_rqst->rq_server;
 340        }
 341
 342        /*
 343         * Sanity check: if there's no pid,
 344         * we should be the first user ...
 345         */
 346        if (nlmsvc_users)
 347                printk(KERN_WARNING
 348                        "lockd_up: no pid, %d users??\n", nlmsvc_users);
 349
 350        serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 351        if (!serv) {
 352                printk(KERN_WARNING "lockd_up: create service failed\n");
 353                return ERR_PTR(-ENOMEM);
 354        }
 355        dprintk("lockd_up: service created\n");
 356        return serv;
 357}
 358
 359/*
 360 * Bring up the lockd process if it's not already up.
 361 */
 362int lockd_up(struct net *net)
 363{
 364        struct svc_serv *serv;
 365        int error;
 366
 367        mutex_lock(&nlmsvc_mutex);
 368
 369        serv = lockd_create_svc();
 370        if (IS_ERR(serv)) {
 371                error = PTR_ERR(serv);
 372                goto err_create;
 373        }
 374
 375        error = lockd_up_net(serv, net);
 376        if (error < 0)
 377                goto err_net;
 378
 379        error = lockd_start_svc(serv);
 380        if (error < 0)
 381                goto err_start;
 382
 383        nlmsvc_users++;
 384        /*
 385         * Note: svc_serv structures have an initial use count of 1,
 386         * so we exit through here on both success and failure.
 387         */
 388err_net:
 389        svc_destroy(serv);
 390err_create:
 391        mutex_unlock(&nlmsvc_mutex);
 392        return error;
 393
 394err_start:
 395        lockd_down_net(serv, net);
 396        goto err_net;
 397}
 398EXPORT_SYMBOL_GPL(lockd_up);
 399
 400/*
 401 * Decrement the user count and bring down lockd if we're the last.
 402 */
 403void
 404lockd_down(struct net *net)
 405{
 406        mutex_lock(&nlmsvc_mutex);
 407        lockd_down_net(nlmsvc_rqst->rq_server, net);
 408        if (nlmsvc_users) {
 409                if (--nlmsvc_users)
 410                        goto out;
 411        } else {
 412                printk(KERN_ERR "lockd_down: no users! task=%p\n",
 413                        nlmsvc_task);
 414                BUG();
 415        }
 416
 417        if (!nlmsvc_task) {
 418                printk(KERN_ERR "lockd_down: no lockd running.\n");
 419                BUG();
 420        }
 421        kthread_stop(nlmsvc_task);
 422        dprintk("lockd_down: service stopped\n");
 423        svc_exit_thread(nlmsvc_rqst);
 424        dprintk("lockd_down: service destroyed\n");
 425        nlmsvc_task = NULL;
 426        nlmsvc_rqst = NULL;
 427out:
 428        mutex_unlock(&nlmsvc_mutex);
 429}
 430EXPORT_SYMBOL_GPL(lockd_down);
 431
 432#ifdef CONFIG_SYSCTL
 433
 434/*
 435 * Sysctl parameters (same as module parameters, different interface).
 436 */
 437
 438static ctl_table nlm_sysctls[] = {
 439        {
 440                .procname       = "nlm_grace_period",
 441                .data           = &nlm_grace_period,
 442                .maxlen         = sizeof(unsigned long),
 443                .mode           = 0644,
 444                .proc_handler   = proc_doulongvec_minmax,
 445                .extra1         = (unsigned long *) &nlm_grace_period_min,
 446                .extra2         = (unsigned long *) &nlm_grace_period_max,
 447        },
 448        {
 449                .procname       = "nlm_timeout",
 450                .data           = &nlm_timeout,
 451                .maxlen         = sizeof(unsigned long),
 452                .mode           = 0644,
 453                .proc_handler   = proc_doulongvec_minmax,
 454                .extra1         = (unsigned long *) &nlm_timeout_min,
 455                .extra2         = (unsigned long *) &nlm_timeout_max,
 456        },
 457        {
 458                .procname       = "nlm_udpport",
 459                .data           = &nlm_udpport,
 460                .maxlen         = sizeof(int),
 461                .mode           = 0644,
 462                .proc_handler   = proc_dointvec_minmax,
 463                .extra1         = (int *) &nlm_port_min,
 464                .extra2         = (int *) &nlm_port_max,
 465        },
 466        {
 467                .procname       = "nlm_tcpport",
 468                .data           = &nlm_tcpport,
 469                .maxlen         = sizeof(int),
 470                .mode           = 0644,
 471                .proc_handler   = proc_dointvec_minmax,
 472                .extra1         = (int *) &nlm_port_min,
 473                .extra2         = (int *) &nlm_port_max,
 474        },
 475        {
 476                .procname       = "nsm_use_hostnames",
 477                .data           = &nsm_use_hostnames,
 478                .maxlen         = sizeof(int),
 479                .mode           = 0644,
 480                .proc_handler   = proc_dointvec,
 481        },
 482        {
 483                .procname       = "nsm_local_state",
 484                .data           = &nsm_local_state,
 485                .maxlen         = sizeof(int),
 486                .mode           = 0644,
 487                .proc_handler   = proc_dointvec,
 488        },
 489        { }
 490};
 491
 492static ctl_table nlm_sysctl_dir[] = {
 493        {
 494                .procname       = "nfs",
 495                .mode           = 0555,
 496                .child          = nlm_sysctls,
 497        },
 498        { }
 499};
 500
 501static ctl_table nlm_sysctl_root[] = {
 502        {
 503                .procname       = "fs",
 504                .mode           = 0555,
 505                .child          = nlm_sysctl_dir,
 506        },
 507        { }
 508};
 509
 510#endif  /* CONFIG_SYSCTL */
 511
 512/*
 513 * Module (and sysfs) parameters.
 514 */
 515
 516#define param_set_min_max(name, type, which_strtol, min, max)           \
 517static int param_set_##name(const char *val, struct kernel_param *kp)   \
 518{                                                                       \
 519        char *endp;                                                     \
 520        __typeof__(type) num = which_strtol(val, &endp, 0);             \
 521        if (endp == val || *endp || num < (min) || num > (max))         \
 522                return -EINVAL;                                         \
 523        *((type *) kp->arg) = num;                                      \
 524        return 0;                                                       \
 525}
 526
 527static inline int is_callback(u32 proc)
 528{
 529        return proc == NLMPROC_GRANTED
 530                || proc == NLMPROC_GRANTED_MSG
 531                || proc == NLMPROC_TEST_RES
 532                || proc == NLMPROC_LOCK_RES
 533                || proc == NLMPROC_CANCEL_RES
 534                || proc == NLMPROC_UNLOCK_RES
 535                || proc == NLMPROC_NSM_NOTIFY;
 536}
 537
 538
 539static int lockd_authenticate(struct svc_rqst *rqstp)
 540{
 541        rqstp->rq_client = NULL;
 542        switch (rqstp->rq_authop->flavour) {
 543                case RPC_AUTH_NULL:
 544                case RPC_AUTH_UNIX:
 545                        if (rqstp->rq_proc == 0)
 546                                return SVC_OK;
 547                        if (is_callback(rqstp->rq_proc)) {
 548                                /* Leave it to individual procedures to
 549                                 * call nlmsvc_lookup_host(rqstp)
 550                                 */
 551                                return SVC_OK;
 552                        }
 553                        return svc_set_client(rqstp);
 554        }
 555        return SVC_DENIED;
 556}
 557
 558
 559param_set_min_max(port, int, simple_strtol, 0, 65535)
 560param_set_min_max(grace_period, unsigned long, simple_strtoul,
 561                  nlm_grace_period_min, nlm_grace_period_max)
 562param_set_min_max(timeout, unsigned long, simple_strtoul,
 563                  nlm_timeout_min, nlm_timeout_max)
 564
 565MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 566MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 567MODULE_LICENSE("GPL");
 568
 569module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 570                  &nlm_grace_period, 0644);
 571module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 572                  &nlm_timeout, 0644);
 573module_param_call(nlm_udpport, param_set_port, param_get_int,
 574                  &nlm_udpport, 0644);
 575module_param_call(nlm_tcpport, param_set_port, param_get_int,
 576                  &nlm_tcpport, 0644);
 577module_param(nsm_use_hostnames, bool, 0644);
 578module_param(nlm_max_connections, uint, 0644);
 579
 580static int lockd_init_net(struct net *net)
 581{
 582        struct lockd_net *ln = net_generic(net, lockd_net_id);
 583
 584        INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
 585        INIT_LIST_HEAD(&ln->grace_list);
 586        spin_lock_init(&ln->nsm_clnt_lock);
 587        return 0;
 588}
 589
 590static void lockd_exit_net(struct net *net)
 591{
 592}
 593
 594static struct pernet_operations lockd_net_ops = {
 595        .init = lockd_init_net,
 596        .exit = lockd_exit_net,
 597        .id = &lockd_net_id,
 598        .size = sizeof(struct lockd_net),
 599};
 600
 601
 602/*
 603 * Initialising and terminating the module.
 604 */
 605
 606static int __init init_nlm(void)
 607{
 608        int err;
 609
 610#ifdef CONFIG_SYSCTL
 611        err = -ENOMEM;
 612        nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 613        if (nlm_sysctl_table == NULL)
 614                goto err_sysctl;
 615#endif
 616        err = register_pernet_subsys(&lockd_net_ops);
 617        if (err)
 618                goto err_pernet;
 619        return 0;
 620
 621err_pernet:
 622#ifdef CONFIG_SYSCTL
 623        unregister_sysctl_table(nlm_sysctl_table);
 624#endif
 625err_sysctl:
 626        return err;
 627}
 628
 629static void __exit exit_nlm(void)
 630{
 631        /* FIXME: delete all NLM clients */
 632        nlm_shutdown_hosts();
 633        unregister_pernet_subsys(&lockd_net_ops);
 634#ifdef CONFIG_SYSCTL
 635        unregister_sysctl_table(nlm_sysctl_table);
 636#endif
 637}
 638
 639module_init(init_nlm);
 640module_exit(exit_nlm);
 641
 642/*
 643 * Define NLM program and procedures
 644 */
 645static struct svc_version       nlmsvc_version1 = {
 646                .vs_vers        = 1,
 647                .vs_nproc       = 17,
 648                .vs_proc        = nlmsvc_procedures,
 649                .vs_xdrsize     = NLMSVC_XDRSIZE,
 650};
 651static struct svc_version       nlmsvc_version3 = {
 652                .vs_vers        = 3,
 653                .vs_nproc       = 24,
 654                .vs_proc        = nlmsvc_procedures,
 655                .vs_xdrsize     = NLMSVC_XDRSIZE,
 656};
 657#ifdef CONFIG_LOCKD_V4
 658static struct svc_version       nlmsvc_version4 = {
 659                .vs_vers        = 4,
 660                .vs_nproc       = 24,
 661                .vs_proc        = nlmsvc_procedures4,
 662                .vs_xdrsize     = NLMSVC_XDRSIZE,
 663};
 664#endif
 665static struct svc_version *     nlmsvc_version[] = {
 666        [1] = &nlmsvc_version1,
 667        [3] = &nlmsvc_version3,
 668#ifdef CONFIG_LOCKD_V4
 669        [4] = &nlmsvc_version4,
 670#endif
 671};
 672
 673static struct svc_stat          nlmsvc_stats;
 674
 675#define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 676static struct svc_program       nlmsvc_program = {
 677        .pg_prog                = NLM_PROGRAM,          /* program number */
 678        .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 679        .pg_vers                = nlmsvc_version,       /* version table */
 680        .pg_name                = "lockd",              /* service name */
 681        .pg_class               = "nfsd",               /* share authentication with nfsd */
 682        .pg_stats               = &nlmsvc_stats,        /* stats table */
 683        .pg_authenticate = &lockd_authenticate  /* export authentication */
 684};
 685
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