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