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/smp_lock.h>
  13 #include <linux/lockd/lockd.h>
  14 #include <linux/lockd/share.h>
  15
  16 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  17
  18 #ifdef CONFIG_LOCKD_V4
  19 static __be32
  20 cast_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  */
  50 static __be32
  51 nlmsvc_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                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 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         nlm_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         nlm_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         nlm_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         nlm_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         nlm_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 static void nlmsvc_callback_release(void *data)
 262 {
 263         nlm_release_call(data);
 264 }
 265
 266 static const struct rpc_call_ops nlmsvc_callback_ops = {
 267         .rpc_call_done = nlmsvc_callback_exit,
 268         .rpc_release = nlmsvc_callback_release,
 269 };
 270
 271 /*
 272  * `Async' versions of the above service routines. They aren't really,
 273  * because we send the callback before the reply proper. I hope this
 274  * doesn't break any clients.
 275  */
 276 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 277                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 278 {
 279         struct nlm_host *host;
 280         struct nlm_rqst *call;
 281         __be32 stat;
 282
 283         host = nlmsvc_lookup_host(rqstp,
 284                                   argp->lock.caller,
 285                                   argp->lock.len);
 286         if (host == NULL)
 287                 return rpc_system_err;
 288
 289         call = nlm_alloc_call(host);
 290         if (call == NULL)
 291                 return rpc_system_err;
 292
 293         stat = func(rqstp, argp, &call->a_res);
 294         if (stat != 0) {
 295                 nlm_release_call(call);
 296                 return stat;
 297         }
 298
 299         call->a_flags = RPC_TASK_ASYNC;
 300         if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 301                 return rpc_system_err;
 302         return rpc_success;
 303 }
 304
 305 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 306                                              void            *resp)
 307 {
 308         dprintk("lockd: TEST_MSG      called\n");
 309         return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
 310 }
 311
 312 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 313                                              void            *resp)
 314 {
 315         dprintk("lockd: LOCK_MSG      called\n");
 316         return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
 317 }
 318
 319 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 320                                                void            *resp)
 321 {
 322         dprintk("lockd: CANCEL_MSG    called\n");
 323         return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
 324 }
 325
 326 static __be32
 327 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 328                                                void            *resp)
 329 {
 330         dprintk("lockd: UNLOCK_MSG    called\n");
 331         return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
 332 }
 333
 334 static __be32
 335 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 336                                                 void            *resp)
 337 {
 338         dprintk("lockd: GRANTED_MSG   called\n");
 339         return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
 340 }
 341
 342 /*
 343  * SHARE: create a DOS share or alter existing share.
 344  */
 345 static __be32
 346 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 347                                           struct nlm_res  *resp)
 348 {
 349         struct nlm_host *host;
 350         struct nlm_file *file;
 351
 352         dprintk("lockd: SHARE         called\n");
 353
 354         resp->cookie = argp->cookie;
 355
 356         /* Don't accept new lock requests during grace period */
 357         if (locks_in_grace() && !argp->reclaim) {
 358                 resp->status = nlm_lck_denied_grace_period;
 359                 return rpc_success;
 360         }
 361
 362         /* Obtain client and file */
 363         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 364                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 365
 366         /* Now try to create the share */
 367         resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 368
 369         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 370         nlm_release_host(host);
 371         nlm_release_file(file);
 372         return rpc_success;
 373 }
 374
 375 /*
 376  * UNSHARE: Release a DOS share.
 377  */
 378 static __be32
 379 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 380                                             struct nlm_res  *resp)
 381 {
 382         struct nlm_host *host;
 383         struct nlm_file *file;
 384
 385         dprintk("lockd: UNSHARE       called\n");
 386
 387         resp->cookie = argp->cookie;
 388
 389         /* Don't accept requests during grace period */
 390         if (locks_in_grace()) {
 391                 resp->status = nlm_lck_denied_grace_period;
 392                 return rpc_success;
 393         }
 394
 395         /* Obtain client and file */
 396         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 397                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 398
 399         /* Now try to unshare the file */
 400         resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 401
 402         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 403         nlm_release_host(host);
 404         nlm_release_file(file);
 405         return rpc_success;
 406 }
 407
 408 /*
 409  * NM_LOCK: Create an unmonitored lock
 410  */
 411 static __be32
 412 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 413                                             struct nlm_res  *resp)
 414 {
 415         dprintk("lockd: NM_LOCK       called\n");
 416
 417         argp->monitor = 0;              /* just clean the monitor flag */
 418         return nlmsvc_proc_lock(rqstp, argp, resp);
 419 }
 420
 421 /*
 422  * FREE_ALL: Release all locks and shares held by client
 423  */
 424 static __be32
 425 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 426                                              void            *resp)
 427 {
 428         struct nlm_host *host;
 429
 430         /* Obtain client */
 431         if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 432                 return rpc_success;
 433
 434         nlmsvc_free_host_resources(host);
 435         nlm_release_host(host);
 436         return rpc_success;
 437 }
 438
 439 /*
 440  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 441  */
 442 static __be32
 443 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 444                                               void              *resp)
 445 {
 446         dprintk("lockd: SM_NOTIFY     called\n");
 447
 448         if (!nlm_privileged_requester(rqstp)) {
 449                 char buf[RPC_MAX_ADDRBUFLEN];
 450                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 451                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 452                 return rpc_system_err;
 453         }
 454
 455         nlm_host_rebooted(argp);
 456         return rpc_success;
 457 }
 458
 459 /*
 460  * client sent a GRANTED_RES, let's remove the associated block
 461  */
 462 static __be32
 463 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 464                                                 void            *resp)
 465 {
 466         if (!nlmsvc_ops)
 467                 return rpc_success;
 468
 469         dprintk("lockd: GRANTED_RES   called\n");
 470
 471         nlmsvc_grant_reply(&argp->cookie, argp->status);
 472         return rpc_success;
 473 }
 474
 475 /*
 476  * NLM Server procedures.
 477  */
 478
 479 #define nlmsvc_encode_norep     nlmsvc_encode_void
 480 #define nlmsvc_decode_norep     nlmsvc_decode_void
 481 #define nlmsvc_decode_testres   nlmsvc_decode_void
 482 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 483 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 484 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 485 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 486
 487 #define nlmsvc_proc_none        nlmsvc_proc_null
 488 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 489 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 490 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 491 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 492
 493 struct nlm_void                 { int dummy; };
 494
 495 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 496  { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 497    .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 498    .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 499    .pc_release  = NULL,                                 \
 500    .pc_argsize  = sizeof(struct nlm_##argt),            \
 501    .pc_ressize  = sizeof(struct nlm_##rest),            \
 502    .pc_xdrressize = respsize,                           \
 503  }
 504
 505 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 506 #define St      1                               /* status */
 507 #define No      (1+1024/4)                      /* Net Obj */
 508 #define Rg      2                               /* range - offset + size */
 509
 510 struct svc_procedure            nlmsvc_procedures[] = {
 511   PROC(null,            void,           void,           void,   void, 1),
 512   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 513   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 514   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 515   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 516   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 517   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 518   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 519   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 520   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 521   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 522   PROC(test_res,        testres,        norep,          res,    void, 1),
 523   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 524   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 525   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 526   PROC(granted_res,     res,            norep,          res,    void, 1),
 527   /* statd callback */
 528   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 529   PROC(none,            void,           void,           void,   void, 1),
 530   PROC(none,            void,           void,           void,   void, 1),
 531   PROC(none,            void,           void,           void,   void, 1),
 532   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 533   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 534   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 535   PROC(free_all,        notify,         void,           args,   void, 0),
 536
 537 };