linux/fs/lockd/svcproc.c
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   1/*
   2 * linux/fs/lockd/svcproc.c
   3 *
   4 * Lockd server procedures. We don't implement the NLM_*_RES 
   5 * procedures because we don't use the async procedures.
   6 *
   7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   8 */
   9
  10#include <linux/types.h>
  11#include <linux/time.h>
  12#include <linux/lockd/lockd.h>
  13#include <linux/lockd/share.h>
  14#include <linux/sunrpc/svc_xprt.h>
  15
  16#define NLMDBG_FACILITY         NLMDBG_CLIENT
  17
  18#ifdef CONFIG_LOCKD_V4
  19static __be32
  20cast_to_nlm(__be32 status, u32 vers)
  21{
  22        /* Note: status is assumed to be in network byte order !!! */
  23        if (vers != 4){
  24                switch (status) {
  25                case nlm_granted:
  26                case nlm_lck_denied:
  27                case nlm_lck_denied_nolocks:
  28                case nlm_lck_blocked:
  29                case nlm_lck_denied_grace_period:
  30                case nlm_drop_reply:
  31                        break;
  32                case nlm4_deadlock:
  33                        status = nlm_lck_denied;
  34                        break;
  35                default:
  36                        status = nlm_lck_denied_nolocks;
  37                }
  38        }
  39
  40        return (status);
  41}
  42#define cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
  43#else
  44#define cast_status(status) (status)
  45#endif
  46
  47/*
  48 * Obtain client and file from arguments
  49 */
  50static __be32
  51nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  52                        struct nlm_host **hostp, struct nlm_file **filp)
  53{
  54        struct nlm_host         *host = NULL;
  55        struct nlm_file         *file = NULL;
  56        struct nlm_lock         *lock = &argp->lock;
  57        __be32                  error = 0;
  58
  59        /* nfsd callbacks must have been installed for this procedure */
  60        if (!nlmsvc_ops)
  61                return nlm_lck_denied_nolocks;
  62
  63        /* Obtain host handle */
  64        if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  65         || (argp->monitor && nsm_monitor(host) < 0))
  66                goto no_locks;
  67        *hostp = host;
  68
  69        /* Obtain file pointer. Not used by FREE_ALL call. */
  70        if (filp != NULL) {
  71                error = cast_status(nlm_lookup_file(rqstp, &file, &lock->fh));
  72                if (error != 0)
  73                        goto no_locks;
  74                *filp = file;
  75
  76                /* Set up the missing parts of the file_lock structure */
  77                lock->fl.fl_file  = file->f_file;
  78                lock->fl.fl_owner = (fl_owner_t) host;
  79                lock->fl.fl_lmops = &nlmsvc_lock_operations;
  80        }
  81
  82        return 0;
  83
  84no_locks:
  85        nlmsvc_release_host(host);
  86        if (error)
  87                return error;
  88        return nlm_lck_denied_nolocks;
  89}
  90
  91/*
  92 * NULL: Test for presence of service
  93 */
  94static __be32
  95nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  96{
  97        dprintk("lockd: NULL          called\n");
  98        return rpc_success;
  99}
 100
 101/*
 102 * TEST: Check for conflicting lock
 103 */
 104static __be32
 105nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
 106                                         struct nlm_res  *resp)
 107{
 108        struct nlm_host *host;
 109        struct nlm_file *file;
 110        __be32 rc = rpc_success;
 111
 112        dprintk("lockd: TEST          called\n");
 113        resp->cookie = argp->cookie;
 114
 115        /* Obtain client and file */
 116        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 117                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 118
 119        /* Now check for conflicting locks */
 120        resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
 121        if (resp->status == nlm_drop_reply)
 122                rc = rpc_drop_reply;
 123        else
 124                dprintk("lockd: TEST          status %d vers %d\n",
 125                        ntohl(resp->status), rqstp->rq_vers);
 126
 127        nlmsvc_release_host(host);
 128        nlm_release_file(file);
 129        return rc;
 130}
 131
 132static __be32
 133nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 134                                         struct nlm_res  *resp)
 135{
 136        struct nlm_host *host;
 137        struct nlm_file *file;
 138        __be32 rc = rpc_success;
 139
 140        dprintk("lockd: LOCK          called\n");
 141
 142        resp->cookie = argp->cookie;
 143
 144        /* Obtain client and file */
 145        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 146                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 147
 148#if 0
 149        /* If supplied state doesn't match current state, we assume it's
 150         * an old request that time-warped somehow. Any error return would
 151         * do in this case because it's irrelevant anyway.
 152         *
 153         * NB: We don't retrieve the remote host's state yet.
 154         */
 155        if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 156                resp->status = nlm_lck_denied_nolocks;
 157        } else
 158#endif
 159
 160        /* Now try to lock the file */
 161        resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 162                                               argp->block, &argp->cookie,
 163                                               argp->reclaim));
 164        if (resp->status == nlm_drop_reply)
 165                rc = rpc_drop_reply;
 166        else
 167                dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 168
 169        nlmsvc_release_host(host);
 170        nlm_release_file(file);
 171        return rc;
 172}
 173
 174static __be32
 175nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 176                                           struct nlm_res  *resp)
 177{
 178        struct nlm_host *host;
 179        struct nlm_file *file;
 180        struct net *net = SVC_NET(rqstp);
 181
 182        dprintk("lockd: CANCEL        called\n");
 183
 184        resp->cookie = argp->cookie;
 185
 186        /* Don't accept requests during grace period */
 187        if (locks_in_grace(net)) {
 188                resp->status = nlm_lck_denied_grace_period;
 189                return rpc_success;
 190        }
 191
 192        /* Obtain client and file */
 193        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 194                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 195
 196        /* Try to cancel request. */
 197        resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
 198
 199        dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 200        nlmsvc_release_host(host);
 201        nlm_release_file(file);
 202        return rpc_success;
 203}
 204
 205/*
 206 * UNLOCK: release a lock
 207 */
 208static __be32
 209nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 210                                           struct nlm_res  *resp)
 211{
 212        struct nlm_host *host;
 213        struct nlm_file *file;
 214        struct net *net = SVC_NET(rqstp);
 215
 216        dprintk("lockd: UNLOCK        called\n");
 217
 218        resp->cookie = argp->cookie;
 219
 220        /* Don't accept new lock requests during grace period */
 221        if (locks_in_grace(net)) {
 222                resp->status = nlm_lck_denied_grace_period;
 223                return rpc_success;
 224        }
 225
 226        /* Obtain client and file */
 227        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 228                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 229
 230        /* Now try to remove the lock */
 231        resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
 232
 233        dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 234        nlmsvc_release_host(host);
 235        nlm_release_file(file);
 236        return rpc_success;
 237}
 238
 239/*
 240 * GRANTED: A server calls us to tell that a process' lock request
 241 * was granted
 242 */
 243static __be32
 244nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 245                                            struct nlm_res  *resp)
 246{
 247        resp->cookie = argp->cookie;
 248
 249        dprintk("lockd: GRANTED       called\n");
 250        resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 251        dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 252        return rpc_success;
 253}
 254
 255/*
 256 * This is the generic lockd callback for async RPC calls
 257 */
 258static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 259{
 260        dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 261                        -task->tk_status);
 262}
 263
 264void nlmsvc_release_call(struct nlm_rqst *call)
 265{
 266        if (!atomic_dec_and_test(&call->a_count))
 267                return;
 268        nlmsvc_release_host(call->a_host);
 269        kfree(call);
 270}
 271
 272static void nlmsvc_callback_release(void *data)
 273{
 274        nlmsvc_release_call(data);
 275}
 276
 277static const struct rpc_call_ops nlmsvc_callback_ops = {
 278        .rpc_call_done = nlmsvc_callback_exit,
 279        .rpc_release = nlmsvc_callback_release,
 280};
 281
 282/*
 283 * `Async' versions of the above service routines. They aren't really,
 284 * because we send the callback before the reply proper. I hope this
 285 * doesn't break any clients.
 286 */
 287static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 288                __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 289{
 290        struct nlm_host *host;
 291        struct nlm_rqst *call;
 292        __be32 stat;
 293
 294        host = nlmsvc_lookup_host(rqstp,
 295                                  argp->lock.caller,
 296                                  argp->lock.len);
 297        if (host == NULL)
 298                return rpc_system_err;
 299
 300        call = nlm_alloc_call(host);
 301        nlmsvc_release_host(host);
 302        if (call == NULL)
 303                return rpc_system_err;
 304
 305        stat = func(rqstp, argp, &call->a_res);
 306        if (stat != 0) {
 307                nlmsvc_release_call(call);
 308                return stat;
 309        }
 310
 311        call->a_flags = RPC_TASK_ASYNC;
 312        if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 313                return rpc_system_err;
 314        return rpc_success;
 315}
 316
 317static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 318                                             void            *resp)
 319{
 320        dprintk("lockd: TEST_MSG      called\n");
 321        return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
 322}
 323
 324static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 325                                             void            *resp)
 326{
 327        dprintk("lockd: LOCK_MSG      called\n");
 328        return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
 329}
 330
 331static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 332                                               void            *resp)
 333{
 334        dprintk("lockd: CANCEL_MSG    called\n");
 335        return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
 336}
 337
 338static __be32
 339nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 340                                               void            *resp)
 341{
 342        dprintk("lockd: UNLOCK_MSG    called\n");
 343        return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
 344}
 345
 346static __be32
 347nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 348                                                void            *resp)
 349{
 350        dprintk("lockd: GRANTED_MSG   called\n");
 351        return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
 352}
 353
 354/*
 355 * SHARE: create a DOS share or alter existing share.
 356 */
 357static __be32
 358nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 359                                          struct nlm_res  *resp)
 360{
 361        struct nlm_host *host;
 362        struct nlm_file *file;
 363
 364        dprintk("lockd: SHARE         called\n");
 365
 366        resp->cookie = argp->cookie;
 367
 368        /* Don't accept new lock requests during grace period */
 369        if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
 370                resp->status = nlm_lck_denied_grace_period;
 371                return rpc_success;
 372        }
 373
 374        /* Obtain client and file */
 375        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 376                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 377
 378        /* Now try to create the share */
 379        resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 380
 381        dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 382        nlmsvc_release_host(host);
 383        nlm_release_file(file);
 384        return rpc_success;
 385}
 386
 387/*
 388 * UNSHARE: Release a DOS share.
 389 */
 390static __be32
 391nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 392                                            struct nlm_res  *resp)
 393{
 394        struct nlm_host *host;
 395        struct nlm_file *file;
 396
 397        dprintk("lockd: UNSHARE       called\n");
 398
 399        resp->cookie = argp->cookie;
 400
 401        /* Don't accept requests during grace period */
 402        if (locks_in_grace(SVC_NET(rqstp))) {
 403                resp->status = nlm_lck_denied_grace_period;
 404                return rpc_success;
 405        }
 406
 407        /* Obtain client and file */
 408        if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 409                return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 410
 411        /* Now try to unshare the file */
 412        resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 413
 414        dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 415        nlmsvc_release_host(host);
 416        nlm_release_file(file);
 417        return rpc_success;
 418}
 419
 420/*
 421 * NM_LOCK: Create an unmonitored lock
 422 */
 423static __be32
 424nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 425                                            struct nlm_res  *resp)
 426{
 427        dprintk("lockd: NM_LOCK       called\n");
 428
 429        argp->monitor = 0;              /* just clean the monitor flag */
 430        return nlmsvc_proc_lock(rqstp, argp, resp);
 431}
 432
 433/*
 434 * FREE_ALL: Release all locks and shares held by client
 435 */
 436static __be32
 437nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 438                                             void            *resp)
 439{
 440        struct nlm_host *host;
 441
 442        /* Obtain client */
 443        if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 444                return rpc_success;
 445
 446        nlmsvc_free_host_resources(host);
 447        nlmsvc_release_host(host);
 448        return rpc_success;
 449}
 450
 451/*
 452 * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 453 */
 454static __be32
 455nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 456                                              void              *resp)
 457{
 458        dprintk("lockd: SM_NOTIFY     called\n");
 459
 460        if (!nlm_privileged_requester(rqstp)) {
 461                char buf[RPC_MAX_ADDRBUFLEN];
 462                printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 463                                svc_print_addr(rqstp, buf, sizeof(buf)));
 464                return rpc_system_err;
 465        }
 466
 467        nlm_host_rebooted(argp);
 468        return rpc_success;
 469}
 470
 471/*
 472 * client sent a GRANTED_RES, let's remove the associated block
 473 */
 474static __be32
 475nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 476                                                void            *resp)
 477{
 478        if (!nlmsvc_ops)
 479                return rpc_success;
 480
 481        dprintk("lockd: GRANTED_RES   called\n");
 482
 483        nlmsvc_grant_reply(&argp->cookie, argp->status);
 484        return rpc_success;
 485}
 486
 487/*
 488 * NLM Server procedures.
 489 */
 490
 491#define nlmsvc_encode_norep     nlmsvc_encode_void
 492#define nlmsvc_decode_norep     nlmsvc_decode_void
 493#define nlmsvc_decode_testres   nlmsvc_decode_void
 494#define nlmsvc_decode_lockres   nlmsvc_decode_void
 495#define nlmsvc_decode_unlockres nlmsvc_decode_void
 496#define nlmsvc_decode_cancelres nlmsvc_decode_void
 497#define nlmsvc_decode_grantedres        nlmsvc_decode_void
 498
 499#define nlmsvc_proc_none        nlmsvc_proc_null
 500#define nlmsvc_proc_test_res    nlmsvc_proc_null
 501#define nlmsvc_proc_lock_res    nlmsvc_proc_null
 502#define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 503#define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 504
 505struct nlm_void                 { int dummy; };
 506
 507#define PROC(name, xargt, xrest, argt, rest, respsize)  \
 508 { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 509   .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 510   .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 511   .pc_release  = NULL,                                 \
 512   .pc_argsize  = sizeof(struct nlm_##argt),            \
 513   .pc_ressize  = sizeof(struct nlm_##rest),            \
 514   .pc_xdrressize = respsize,                           \
 515 }
 516
 517#define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 518#define St      1                               /* status */
 519#define No      (1+1024/4)                      /* Net Obj */
 520#define Rg      2                               /* range - offset + size */
 521
 522struct svc_procedure            nlmsvc_procedures[] = {
 523  PROC(null,            void,           void,           void,   void, 1),
 524  PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 525  PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 526  PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 527  PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 528  PROC(granted,         testargs,       res,            args,   res, Ck+St),
 529  PROC(test_msg,        testargs,       norep,          args,   void, 1),
 530  PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 531  PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 532  PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 533  PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 534  PROC(test_res,        testres,        norep,          res,    void, 1),
 535  PROC(lock_res,        lockres,        norep,          res,    void, 1),
 536  PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 537  PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 538  PROC(granted_res,     res,            norep,          res,    void, 1),
 539  /* statd callback */
 540  PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 541  PROC(none,            void,           void,           void,   void, 1),
 542  PROC(none,            void,           void,           void,   void, 1),
 543  PROC(none,            void,           void,           void,   void, 1),
 544  PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 545  PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 546  PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 547  PROC(free_all,        notify,         void,           args,   void, 0),
 548
 549};
 550
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