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, 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  */
 104 static __be32
 105 nlmsvc_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
 132 static __be32
 133 nlmsvc_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
 174 static __be32
 175 nlmsvc_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  */
 208 static __be32
 209 nlmsvc_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  */
 243 static __be32
 244 nlmsvc_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  */
 258 static 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
 264 void 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
 272 static void nlmsvc_callback_release(void *data)
 273 {
 274         nlmsvc_release_call(data);
 275 }
 276
 277 static 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  */
 287 static __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
 317 static __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
 324 static __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
 331 static __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
 338 static __be32
 339 nlmsvc_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
 346 static __be32
 347 nlmsvc_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  */
 357 static __be32
 358 nlmsvc_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  */
 390 static __be32
 391 nlmsvc_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  */
 423 static __be32
 424 nlmsvc_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  */
 436 static __be32
 437 nlmsvc_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  */
 454 static __be32
 455 nlmsvc_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(SVC_NET(rqstp), argp);
 468         return rpc_success;
 469 }
 470
 471 /*
 472  * client sent a GRANTED_RES, let's remove the associated block
 473  */
 474 static __be32
 475 nlmsvc_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
 505 struct 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
 522 struct 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 };