fs/lockd/svcproc.c

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