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 #include <linux/sunrpc/svc_xprt.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                 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
  84 no_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  */
  94 static __be32
  95 nlmsvc_proc_null(struct svc_rqst *rqstp)
  96 {
  97         dprintk("lockd: NULL          called\n");
  98         return rpc_success;
  99 }
 100
 101 /*
 102  * TEST: Check for conflicting lock
 103  */
 104 static __be32
 105 __nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
 106 {
 107         struct nlm_args *argp = rqstp->rq_argp;
 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
 132 static __be32
 133 nlmsvc_proc_test(struct svc_rqst *rqstp)
 134 {
 135         return __nlmsvc_proc_test(rqstp, rqstp->rq_resp);
 136 }
 137
 138 static __be32
 139 __nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
 140 {
 141         struct nlm_args *argp = rqstp->rq_argp;
 142         struct nlm_host *host;
 143         struct nlm_file *file;
 144         __be32 rc = rpc_success;
 145
 146         dprintk("lockd: LOCK          called\n");
 147
 148         resp->cookie = argp->cookie;
 149
 150         /* Obtain client and file */
 151         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 152                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 153
 154 #if 0
 155         /* If supplied state doesn't match current state, we assume it's
 156          * an old request that time-warped somehow. Any error return would
 157          * do in this case because it's irrelevant anyway.
 158          *
 159          * NB: We don't retrieve the remote host's state yet.
 160          */
 161         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 162                 resp->status = nlm_lck_denied_nolocks;
 163         } else
 164 #endif
 165
 166         /* Now try to lock the file */
 167         resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 168                                                argp->block, &argp->cookie,
 169                                                argp->reclaim));
 170         if (resp->status == nlm_drop_reply)
 171                 rc = rpc_drop_reply;
 172         else
 173                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 174
 175         nlmsvc_release_host(host);
 176         nlm_release_file(file);
 177         return rc;
 178 }
 179
 180 static __be32
 181 nlmsvc_proc_lock(struct svc_rqst *rqstp)
 182 {
 183         return __nlmsvc_proc_lock(rqstp, rqstp->rq_resp);
 184 }
 185
 186 static __be32
 187 __nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
 188 {
 189         struct nlm_args *argp = rqstp->rq_argp;
 190         struct nlm_host *host;
 191         struct nlm_file *file;
 192         struct net *net = SVC_NET(rqstp);
 193
 194         dprintk("lockd: CANCEL        called\n");
 195
 196         resp->cookie = argp->cookie;
 197
 198         /* Don't accept requests during grace period */
 199         if (locks_in_grace(net)) {
 200                 resp->status = nlm_lck_denied_grace_period;
 201                 return rpc_success;
 202         }
 203
 204         /* Obtain client and file */
 205         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 206                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 207
 208         /* Try to cancel request. */
 209         resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
 210
 211         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 212         nlmsvc_release_host(host);
 213         nlm_release_file(file);
 214         return rpc_success;
 215 }
 216
 217 static __be32
 218 nlmsvc_proc_cancel(struct svc_rqst *rqstp)
 219 {
 220         return __nlmsvc_proc_cancel(rqstp, rqstp->rq_resp);
 221 }
 222
 223 /*
 224  * UNLOCK: release a lock
 225  */
 226 static __be32
 227 __nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
 228 {
 229         struct nlm_args *argp = rqstp->rq_argp;
 230         struct nlm_host *host;
 231         struct nlm_file *file;
 232         struct net *net = SVC_NET(rqstp);
 233
 234         dprintk("lockd: UNLOCK        called\n");
 235
 236         resp->cookie = argp->cookie;
 237
 238         /* Don't accept new lock requests during grace period */
 239         if (locks_in_grace(net)) {
 240                 resp->status = nlm_lck_denied_grace_period;
 241                 return rpc_success;
 242         }
 243
 244         /* Obtain client and file */
 245         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 246                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 247
 248         /* Now try to remove the lock */
 249         resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
 250
 251         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 252         nlmsvc_release_host(host);
 253         nlm_release_file(file);
 254         return rpc_success;
 255 }
 256
 257 static __be32
 258 nlmsvc_proc_unlock(struct svc_rqst *rqstp)
 259 {
 260         return __nlmsvc_proc_unlock(rqstp, rqstp->rq_resp);
 261 }
 262
 263 /*
 264  * GRANTED: A server calls us to tell that a process' lock request
 265  * was granted
 266  */
 267 static __be32
 268 __nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_res *resp)
 269 {
 270         struct nlm_args *argp = rqstp->rq_argp;
 271
 272         resp->cookie = argp->cookie;
 273
 274         dprintk("lockd: GRANTED       called\n");
 275         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 276         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 277         return rpc_success;
 278 }
 279
 280 static __be32
 281 nlmsvc_proc_granted(struct svc_rqst *rqstp)
 282 {
 283         return __nlmsvc_proc_granted(rqstp, rqstp->rq_resp);
 284 }
 285
 286 /*
 287  * This is the generic lockd callback for async RPC calls
 288  */
 289 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 290 {
 291         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 292                         -task->tk_status);
 293 }
 294
 295 void nlmsvc_release_call(struct nlm_rqst *call)
 296 {
 297         if (!atomic_dec_and_test(&call->a_count))
 298                 return;
 299         nlmsvc_release_host(call->a_host);
 300         kfree(call);
 301 }
 302
 303 static void nlmsvc_callback_release(void *data)
 304 {
 305         nlmsvc_release_call(data);
 306 }
 307
 308 static const struct rpc_call_ops nlmsvc_callback_ops = {
 309         .rpc_call_done = nlmsvc_callback_exit,
 310         .rpc_release = nlmsvc_callback_release,
 311 };
 312
 313 /*
 314  * `Async' versions of the above service routines. They aren't really,
 315  * because we send the callback before the reply proper. I hope this
 316  * doesn't break any clients.
 317  */
 318 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc,
 319                 __be32 (*func)(struct svc_rqst *, struct nlm_res *))
 320 {
 321         struct nlm_args *argp = rqstp->rq_argp;
 322         struct nlm_host *host;
 323         struct nlm_rqst *call;
 324         __be32 stat;
 325
 326         host = nlmsvc_lookup_host(rqstp,
 327                                   argp->lock.caller,
 328                                   argp->lock.len);
 329         if (host == NULL)
 330                 return rpc_system_err;
 331
 332         call = nlm_alloc_call(host);
 333         nlmsvc_release_host(host);
 334         if (call == NULL)
 335                 return rpc_system_err;
 336
 337         stat = func(rqstp, &call->a_res);
 338         if (stat != 0) {
 339                 nlmsvc_release_call(call);
 340                 return stat;
 341         }
 342
 343         call->a_flags = RPC_TASK_ASYNC;
 344         if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 345                 return rpc_system_err;
 346         return rpc_success;
 347 }
 348
 349 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp)
 350 {
 351         dprintk("lockd: TEST_MSG      called\n");
 352         return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, __nlmsvc_proc_test);
 353 }
 354
 355 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp)
 356 {
 357         dprintk("lockd: LOCK_MSG      called\n");
 358         return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, __nlmsvc_proc_lock);
 359 }
 360
 361 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp)
 362 {
 363         dprintk("lockd: CANCEL_MSG    called\n");
 364         return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, __nlmsvc_proc_cancel);
 365 }
 366
 367 static __be32
 368 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp)
 369 {
 370         dprintk("lockd: UNLOCK_MSG    called\n");
 371         return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, __nlmsvc_proc_unlock);
 372 }
 373
 374 static __be32
 375 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp)
 376 {
 377         dprintk("lockd: GRANTED_MSG   called\n");
 378         return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, __nlmsvc_proc_granted);
 379 }
 380
 381 /*
 382  * SHARE: create a DOS share or alter existing share.
 383  */
 384 static __be32
 385 nlmsvc_proc_share(struct svc_rqst *rqstp)
 386 {
 387         struct nlm_args *argp = rqstp->rq_argp;
 388         struct nlm_res *resp = rqstp->rq_resp;
 389         struct nlm_host *host;
 390         struct nlm_file *file;
 391
 392         dprintk("lockd: SHARE         called\n");
 393
 394         resp->cookie = argp->cookie;
 395
 396         /* Don't accept new lock requests during grace period */
 397         if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
 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 create the share */
 407         resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 408
 409         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 410         nlmsvc_release_host(host);
 411         nlm_release_file(file);
 412         return rpc_success;
 413 }
 414
 415 /*
 416  * UNSHARE: Release a DOS share.
 417  */
 418 static __be32
 419 nlmsvc_proc_unshare(struct svc_rqst *rqstp)
 420 {
 421         struct nlm_args *argp = rqstp->rq_argp;
 422         struct nlm_res *resp = rqstp->rq_resp;
 423         struct nlm_host *host;
 424         struct nlm_file *file;
 425
 426         dprintk("lockd: UNSHARE       called\n");
 427
 428         resp->cookie = argp->cookie;
 429
 430         /* Don't accept requests during grace period */
 431         if (locks_in_grace(SVC_NET(rqstp))) {
 432                 resp->status = nlm_lck_denied_grace_period;
 433                 return rpc_success;
 434         }
 435
 436         /* Obtain client and file */
 437         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 438                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 439
 440         /* Now try to unshare the file */
 441         resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 442
 443         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 444         nlmsvc_release_host(host);
 445         nlm_release_file(file);
 446         return rpc_success;
 447 }
 448
 449 /*
 450  * NM_LOCK: Create an unmonitored lock
 451  */
 452 static __be32
 453 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp)
 454 {
 455         struct nlm_args *argp = rqstp->rq_argp;
 456
 457         dprintk("lockd: NM_LOCK       called\n");
 458
 459         argp->monitor = 0;              /* just clean the monitor flag */
 460         return nlmsvc_proc_lock(rqstp);
 461 }
 462
 463 /*
 464  * FREE_ALL: Release all locks and shares held by client
 465  */
 466 static __be32
 467 nlmsvc_proc_free_all(struct svc_rqst *rqstp)
 468 {
 469         struct nlm_args *argp = rqstp->rq_argp;
 470         struct nlm_host *host;
 471
 472         /* Obtain client */
 473         if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 474                 return rpc_success;
 475
 476         nlmsvc_free_host_resources(host);
 477         nlmsvc_release_host(host);
 478         return rpc_success;
 479 }
 480
 481 /*
 482  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 483  */
 484 static __be32
 485 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp)
 486 {
 487         struct nlm_reboot *argp = rqstp->rq_argp;
 488
 489         dprintk("lockd: SM_NOTIFY     called\n");
 490
 491         if (!nlm_privileged_requester(rqstp)) {
 492                 char buf[RPC_MAX_ADDRBUFLEN];
 493                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 494                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 495                 return rpc_system_err;
 496         }
 497
 498         nlm_host_rebooted(SVC_NET(rqstp), argp);
 499         return rpc_success;
 500 }
 501
 502 /*
 503  * client sent a GRANTED_RES, let's remove the associated block
 504  */
 505 static __be32
 506 nlmsvc_proc_granted_res(struct svc_rqst *rqstp)
 507 {
 508         struct nlm_res *argp = rqstp->rq_argp;
 509
 510         if (!nlmsvc_ops)
 511                 return rpc_success;
 512
 513         dprintk("lockd: GRANTED_RES   called\n");
 514
 515         nlmsvc_grant_reply(&argp->cookie, argp->status);
 516         return rpc_success;
 517 }
 518
 519 /*
 520  * NLM Server procedures.
 521  */
 522
 523 #define nlmsvc_encode_norep     nlmsvc_encode_void
 524 #define nlmsvc_decode_norep     nlmsvc_decode_void
 525 #define nlmsvc_decode_testres   nlmsvc_decode_void
 526 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 527 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 528 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 529 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 530
 531 #define nlmsvc_proc_none        nlmsvc_proc_null
 532 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 533 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 534 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 535 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 536
 537 struct nlm_void                 { int dummy; };
 538
 539 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 540  { .pc_func     = nlmsvc_proc_##name,                   \
 541    .pc_decode   = nlmsvc_decode_##xargt,                \
 542    .pc_encode   = nlmsvc_encode_##xrest,                \
 543    .pc_release  = NULL,                                 \
 544    .pc_argsize  = sizeof(struct nlm_##argt),            \
 545    .pc_ressize  = sizeof(struct nlm_##rest),            \
 546    .pc_xdrressize = respsize,                           \
 547  }
 548
 549 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 550 #define St      1                               /* status */
 551 #define No      (1+1024/4)                      /* Net Obj */
 552 #define Rg      2                               /* range - offset + size */
 553
 554 const struct svc_procedure nlmsvc_procedures[] = {
 555   PROC(null,            void,           void,           void,   void, 1),
 556   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 557   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 558   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 559   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 560   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 561   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 562   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 563   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 564   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 565   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 566   PROC(test_res,        testres,        norep,          res,    void, 1),
 567   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 568   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 569   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 570   PROC(granted_res,     res,            norep,          res,    void, 1),
 571   /* statd callback */
 572   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 573   PROC(none,            void,           void,           void,   void, 1),
 574   PROC(none,            void,           void,           void,   void, 1),
 575   PROC(none,            void,           void,           void,   void, 1),
 576   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 577   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 578   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 579   PROC(free_all,        notify,         void,           args,   void, 0),
 580
 581 };