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