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/in.h>
  14 #include <linux/sunrpc/svc.h>
  15 #include <linux/sunrpc/clnt.h>
  16 #include <linux/nfsd/nfsd.h>
  17 #include <linux/lockd/lockd.h>
  18 #include <linux/lockd/share.h>
  19 #include <linux/lockd/sm_inter.h>
  20
  21
  22 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  23
  24 #ifdef CONFIG_LOCKD_V4
  25 static __be32
  26 cast_to_nlm(__be32 status, u32 vers)
  27 {
  28         /* Note: status is assumed to be in network byte order !!! */
  29         if (vers != 4){
  30                 switch (status) {
  31                 case nlm_granted:
  32                 case nlm_lck_denied:
  33                 case nlm_lck_denied_nolocks:
  34                 case nlm_lck_blocked:
  35                 case nlm_lck_denied_grace_period:
  36                 case nlm_drop_reply:
  37                         break;
  38                 case nlm4_deadlock:
  39                         status = nlm_lck_denied;
  40                         break;
  41                 default:
  42                         status = nlm_lck_denied_nolocks;
  43                 }
  44         }
  45
  46         return (status);
  47 }
  48 #define cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
  49 #else
  50 #define cast_status(status) (status)
  51 #endif
  52
  53 /*
  54  * Obtain client and file from arguments
  55  */
  56 static __be32
  57 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  58                         struct nlm_host **hostp, struct nlm_file **filp)
  59 {
  60         struct nlm_host         *host = NULL;
  61         struct nlm_file         *file = NULL;
  62         struct nlm_lock         *lock = &argp->lock;
  63         __be32                  error = 0;
  64
  65         /* nfsd callbacks must have been installed for this procedure */
  66         if (!nlmsvc_ops)
  67                 return nlm_lck_denied_nolocks;
  68
  69         /* Obtain host handle */
  70         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  71          || (argp->monitor && nsm_monitor(host) < 0))
  72                 goto no_locks;
  73         *hostp = host;
  74
  75         /* Obtain file pointer. Not used by FREE_ALL call. */
  76         if (filp != NULL) {
  77                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  78                         goto no_locks;
  79                 *filp = file;
  80
  81                 /* Set up the missing parts of the file_lock structure */
  82                 lock->fl.fl_file  = file->f_file;
  83                 lock->fl.fl_owner = (fl_owner_t) host;
  84                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  85         }
  86
  87         return 0;
  88
  89 no_locks:
  90         nlm_release_host(host);
  91         if (error)
  92                 return error;
  93         return nlm_lck_denied_nolocks;
  94 }
  95
  96 /*
  97  * NULL: Test for presence of service
  98  */
  99 static __be32
 100 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
 101 {
 102         dprintk("lockd: NULL          called\n");
 103         return rpc_success;
 104 }
 105
 106 /*
 107  * TEST: Check for conflicting lock
 108  */
 109 static __be32
 110 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
 111                                          struct nlm_res  *resp)
 112 {
 113         struct nlm_host *host;
 114         struct nlm_file *file;
 115         __be32 rc = rpc_success;
 116
 117         dprintk("lockd: TEST          called\n");
 118         resp->cookie = argp->cookie;
 119
 120         /* Obtain client and file */
 121         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 122                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 123
 124         /* Now check for conflicting locks */
 125         resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
 126         if (resp->status == nlm_drop_reply)
 127                 rc = rpc_drop_reply;
 128         else
 129                 dprintk("lockd: TEST          status %d vers %d\n",
 130                         ntohl(resp->status), rqstp->rq_vers);
 131
 132         nlm_release_host(host);
 133         nlm_release_file(file);
 134         return rc;
 135 }
 136
 137 static __be32
 138 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 139                                          struct nlm_res  *resp)
 140 {
 141         struct nlm_host *host;
 142         struct nlm_file *file;
 143         __be32 rc = rpc_success;
 144
 145         dprintk("lockd: LOCK          called\n");
 146
 147         resp->cookie = argp->cookie;
 148
 149         /* Obtain client and file */
 150         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 151                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 152
 153 #if 0
 154         /* If supplied state doesn't match current state, we assume it's
 155          * an old request that time-warped somehow. Any error return would
 156          * do in this case because it's irrelevant anyway.
 157          *
 158          * NB: We don't retrieve the remote host's state yet.
 159          */
 160         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 161                 resp->status = nlm_lck_denied_nolocks;
 162         } else
 163 #endif
 164
 165         /* Now try to lock the file */
 166         resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 167                                                argp->block, &argp->cookie,
 168                                                argp->reclaim));
 169         if (resp->status == nlm_drop_reply)
 170                 rc = rpc_drop_reply;
 171         else
 172                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 173
 174         nlm_release_host(host);
 175         nlm_release_file(file);
 176         return rc;
 177 }
 178
 179 static __be32
 180 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 181                                            struct nlm_res  *resp)
 182 {
 183         struct nlm_host *host;
 184         struct nlm_file *file;
 185
 186         dprintk("lockd: CANCEL        called\n");
 187
 188         resp->cookie = argp->cookie;
 189
 190         /* Don't accept requests during grace period */
 191         if (locks_in_grace()) {
 192                 resp->status = nlm_lck_denied_grace_period;
 193                 return rpc_success;
 194         }
 195
 196         /* Obtain client and file */
 197         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 198                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 199
 200         /* Try to cancel request. */
 201         resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
 202
 203         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 204         nlm_release_host(host);
 205         nlm_release_file(file);
 206         return rpc_success;
 207 }
 208
 209 /*
 210  * UNLOCK: release a lock
 211  */
 212 static __be32
 213 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 214                                            struct nlm_res  *resp)
 215 {
 216         struct nlm_host *host;
 217         struct nlm_file *file;
 218
 219         dprintk("lockd: UNLOCK        called\n");
 220
 221         resp->cookie = argp->cookie;
 222
 223         /* Don't accept new lock requests during grace period */
 224         if (locks_in_grace()) {
 225                 resp->status = nlm_lck_denied_grace_period;
 226                 return rpc_success;
 227         }
 228
 229         /* Obtain client and file */
 230         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 231                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 232
 233         /* Now try to remove the lock */
 234         resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
 235
 236         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 237         nlm_release_host(host);
 238         nlm_release_file(file);
 239         return rpc_success;
 240 }
 241
 242 /*
 243  * GRANTED: A server calls us to tell that a process' lock request
 244  * was granted
 245  */
 246 static __be32
 247 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 248                                             struct nlm_res  *resp)
 249 {
 250         resp->cookie = argp->cookie;
 251
 252         dprintk("lockd: GRANTED       called\n");
 253         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 254         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 255         return rpc_success;
 256 }
 257
 258 /*
 259  * This is the generic lockd callback for async RPC calls
 260  */
 261 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 262 {
 263         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 264                         -task->tk_status);
 265 }
 266
 267 static void nlmsvc_callback_release(void *data)
 268 {
 269         lock_kernel();
 270         nlm_release_call(data);
 271         unlock_kernel();
 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                 nlm_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         nlm_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         nlm_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         nlm_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         struct sockaddr_in      saddr;
 455
 456         dprintk("lockd: SM_NOTIFY     called\n");
 457
 458         if (!nlm_privileged_requester(rqstp)) {
 459                 char buf[RPC_MAX_ADDRBUFLEN];
 460                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 461                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 462                 return rpc_system_err;
 463         }
 464
 465         /* Obtain the host pointer for this NFS server and try to
 466          * reclaim all locks we hold on this server.
 467          */
 468         memset(&saddr, 0, sizeof(saddr));
 469         saddr.sin_family = AF_INET;
 470         saddr.sin_addr.s_addr = argp->addr;
 471         nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
 472
 473         return rpc_success;
 474 }
 475
 476 /*
 477  * client sent a GRANTED_RES, let's remove the associated block
 478  */
 479 static __be32
 480 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 481                                                 void            *resp)
 482 {
 483         if (!nlmsvc_ops)
 484                 return rpc_success;
 485
 486         dprintk("lockd: GRANTED_RES   called\n");
 487
 488         nlmsvc_grant_reply(&argp->cookie, argp->status);
 489         return rpc_success;
 490 }
 491
 492 /*
 493  * NLM Server procedures.
 494  */
 495
 496 #define nlmsvc_encode_norep     nlmsvc_encode_void
 497 #define nlmsvc_decode_norep     nlmsvc_decode_void
 498 #define nlmsvc_decode_testres   nlmsvc_decode_void
 499 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 500 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 501 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 502 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 503
 504 #define nlmsvc_proc_none        nlmsvc_proc_null
 505 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 506 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 507 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 508 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 509
 510 struct nlm_void                 { int dummy; };
 511
 512 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 513  { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 514    .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 515    .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 516    .pc_release  = NULL,                                 \
 517    .pc_argsize  = sizeof(struct nlm_##argt),            \
 518    .pc_ressize  = sizeof(struct nlm_##rest),            \
 519    .pc_xdrressize = respsize,                           \
 520  }
 521
 522 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 523 #define St      1                               /* status */
 524 #define No      (1+1024/4)                      /* Net Obj */
 525 #define Rg      2                               /* range - offset + size */
 526
 527 struct svc_procedure            nlmsvc_procedures[] = {
 528   PROC(null,            void,           void,           void,   void, 1),
 529   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 530   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 531   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 532   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 533   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 534   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 535   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 536   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 537   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 538   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 539   PROC(test_res,        testres,        norep,          res,    void, 1),
 540   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 541   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 542   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 543   PROC(granted_res,     res,            norep,          res,    void, 1),
 544   /* statd callback */
 545   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 546   PROC(none,            void,           void,           void,   void, 1),
 547   PROC(none,            void,           void,           void,   void, 1),
 548   PROC(none,            void,           void,           void,   void, 1),
 549   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 550   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 551   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 552   PROC(free_all,        notify,         void,           args,   void, 0),
 553
 554 };