fs/lockd/svc4proc.c

   1 /*
   2  * linux/fs/lockd/svc4proc.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/lockd/lockd.h>
  15 #include <linux/lockd/share.h>
  16
  17 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  18
  19 /*
  20  * Obtain client and file from arguments
  21  */
  22 static __be32
  23 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  24                         struct nlm_host **hostp, struct nlm_file **filp)
  25 {
  26         struct nlm_host         *host = NULL;
  27         struct nlm_file         *file = NULL;
  28         struct nlm_lock         *lock = &argp->lock;
  29         __be32                  error = 0;
  30
  31         /* nfsd callbacks must have been installed for this procedure */
  32         if (!nlmsvc_ops)
  33                 return nlm_lck_denied_nolocks;
  34
  35         /* Obtain host handle */
  36         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  37          || (argp->monitor && nsm_monitor(host) < 0))
  38                 goto no_locks;
  39         *hostp = host;
  40
  41         /* Obtain file pointer. Not used by FREE_ALL call. */
  42         if (filp != NULL) {
  43                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  44                         goto no_locks;
  45                 *filp = file;
  46
  47                 /* Set up the missing parts of the file_lock structure */
  48                 lock->fl.fl_file  = file->f_file;
  49                 lock->fl.fl_owner = (fl_owner_t) host;
  50                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  51         }
  52
  53         return 0;
  54
  55 no_locks:
  56         nlm_release_host(host);
  57         if (error)
  58                 return error;
  59         return nlm_lck_denied_nolocks;
  60 }
  61
  62 /*
  63  * NULL: Test for presence of service
  64  */
  65 static __be32
  66 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  67 {
  68         dprintk("lockd: NULL          called\n");
  69         return rpc_success;
  70 }
  71
  72 /*
  73  * TEST: Check for conflicting lock
  74  */
  75 static __be32
  76 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
  77                                          struct nlm_res  *resp)
  78 {
  79         struct nlm_host *host;
  80         struct nlm_file *file;
  81         __be32 rc = rpc_success;
  82
  83         dprintk("lockd: TEST4        called\n");
  84         resp->cookie = argp->cookie;
  85
  86         /* Obtain client and file */
  87         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
  88                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
  89
  90         /* Now check for conflicting locks */
  91         resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
  92         if (resp->status == nlm_drop_reply)
  93                 rc = rpc_drop_reply;
  94         else
  95                 dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
  96
  97         nlm_release_host(host);
  98         nlm_release_file(file);
  99         return rc;
 100 }
 101
 102 static __be32
 103 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 104                                          struct nlm_res  *resp)
 105 {
 106         struct nlm_host *host;
 107         struct nlm_file *file;
 108         __be32 rc = rpc_success;
 109
 110         dprintk("lockd: LOCK          called\n");
 111
 112         resp->cookie = argp->cookie;
 113
 114         /* Obtain client and file */
 115         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 116                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 117
 118 #if 0
 119         /* If supplied state doesn't match current state, we assume it's
 120          * an old request that time-warped somehow. Any error return would
 121          * do in this case because it's irrelevant anyway.
 122          *
 123          * NB: We don't retrieve the remote host's state yet.
 124          */
 125         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 126                 resp->status = nlm_lck_denied_nolocks;
 127         } else
 128 #endif
 129
 130         /* Now try to lock the file */
 131         resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
 132                                         argp->block, &argp->cookie,
 133                                         argp->reclaim);
 134         if (resp->status == nlm_drop_reply)
 135                 rc = rpc_drop_reply;
 136         else
 137                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 138
 139         nlm_release_host(host);
 140         nlm_release_file(file);
 141         return rc;
 142 }
 143
 144 static __be32
 145 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 146                                            struct nlm_res  *resp)
 147 {
 148         struct nlm_host *host;
 149         struct nlm_file *file;
 150
 151         dprintk("lockd: CANCEL        called\n");
 152
 153         resp->cookie = argp->cookie;
 154
 155         /* Don't accept requests during grace period */
 156         if (locks_in_grace()) {
 157                 resp->status = nlm_lck_denied_grace_period;
 158                 return rpc_success;
 159         }
 160
 161         /* Obtain client and file */
 162         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 163                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 164
 165         /* Try to cancel request. */
 166         resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
 167
 168         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 169         nlm_release_host(host);
 170         nlm_release_file(file);
 171         return rpc_success;
 172 }
 173
 174 /*
 175  * UNLOCK: release a lock
 176  */
 177 static __be32
 178 nlm4svc_proc_unlock(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: UNLOCK        called\n");
 185
 186         resp->cookie = argp->cookie;
 187
 188         /* Don't accept new lock 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 = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 196                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 197
 198         /* Now try to remove the lock */
 199         resp->status = nlmsvc_unlock(file, &argp->lock);
 200
 201         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 202         nlm_release_host(host);
 203         nlm_release_file(file);
 204         return rpc_success;
 205 }
 206
 207 /*
 208  * GRANTED: A server calls us to tell that a process' lock request
 209  * was granted
 210  */
 211 static __be32
 212 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 213                                             struct nlm_res  *resp)
 214 {
 215         resp->cookie = argp->cookie;
 216
 217         dprintk("lockd: GRANTED       called\n");
 218         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 219         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 220         return rpc_success;
 221 }
 222
 223 /*
 224  * This is the generic lockd callback for async RPC calls
 225  */
 226 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
 227 {
 228         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 229                         -task->tk_status);
 230 }
 231
 232 static void nlm4svc_callback_release(void *data)
 233 {
 234         lock_kernel();
 235         nlm_release_call(data);
 236         unlock_kernel();
 237 }
 238
 239 static const struct rpc_call_ops nlm4svc_callback_ops = {
 240         .rpc_call_done = nlm4svc_callback_exit,
 241         .rpc_release = nlm4svc_callback_release,
 242 };
 243
 244 /*
 245  * `Async' versions of the above service routines. They aren't really,
 246  * because we send the callback before the reply proper. I hope this
 247  * doesn't break any clients.
 248  */
 249 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 250                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 251 {
 252         struct nlm_host *host;
 253         struct nlm_rqst *call;
 254         __be32 stat;
 255
 256         host = nlmsvc_lookup_host(rqstp,
 257                                   argp->lock.caller,
 258                                   argp->lock.len);
 259         if (host == NULL)
 260                 return rpc_system_err;
 261
 262         call = nlm_alloc_call(host);
 263         if (call == NULL)
 264                 return rpc_system_err;
 265
 266         stat = func(rqstp, argp, &call->a_res);
 267         if (stat != 0) {
 268                 nlm_release_call(call);
 269                 return stat;
 270         }
 271
 272         call->a_flags = RPC_TASK_ASYNC;
 273         if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
 274                 return rpc_system_err;
 275         return rpc_success;
 276 }
 277
 278 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 279                                              void            *resp)
 280 {
 281         dprintk("lockd: TEST_MSG      called\n");
 282         return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
 283 }
 284
 285 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 286                                              void            *resp)
 287 {
 288         dprintk("lockd: LOCK_MSG      called\n");
 289         return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
 290 }
 291
 292 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 293                                                void            *resp)
 294 {
 295         dprintk("lockd: CANCEL_MSG    called\n");
 296         return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
 297 }
 298
 299 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 300                                                void            *resp)
 301 {
 302         dprintk("lockd: UNLOCK_MSG    called\n");
 303         return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
 304 }
 305
 306 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 307                                                 void            *resp)
 308 {
 309         dprintk("lockd: GRANTED_MSG   called\n");
 310         return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
 311 }
 312
 313 /*
 314  * SHARE: create a DOS share or alter existing share.
 315  */
 316 static __be32
 317 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 318                                           struct nlm_res  *resp)
 319 {
 320         struct nlm_host *host;
 321         struct nlm_file *file;
 322
 323         dprintk("lockd: SHARE         called\n");
 324
 325         resp->cookie = argp->cookie;
 326
 327         /* Don't accept new lock requests during grace period */
 328         if (locks_in_grace() && !argp->reclaim) {
 329                 resp->status = nlm_lck_denied_grace_period;
 330                 return rpc_success;
 331         }
 332
 333         /* Obtain client and file */
 334         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 335                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 336
 337         /* Now try to create the share */
 338         resp->status = nlmsvc_share_file(host, file, argp);
 339
 340         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 341         nlm_release_host(host);
 342         nlm_release_file(file);
 343         return rpc_success;
 344 }
 345
 346 /*
 347  * UNSHARE: Release a DOS share.
 348  */
 349 static __be32
 350 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 351                                             struct nlm_res  *resp)
 352 {
 353         struct nlm_host *host;
 354         struct nlm_file *file;
 355
 356         dprintk("lockd: UNSHARE       called\n");
 357
 358         resp->cookie = argp->cookie;
 359
 360         /* Don't accept requests during grace period */
 361         if (locks_in_grace()) {
 362                 resp->status = nlm_lck_denied_grace_period;
 363                 return rpc_success;
 364         }
 365
 366         /* Obtain client and file */
 367         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 368                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 369
 370         /* Now try to lock the file */
 371         resp->status = nlmsvc_unshare_file(host, file, argp);
 372
 373         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 374         nlm_release_host(host);
 375         nlm_release_file(file);
 376         return rpc_success;
 377 }
 378
 379 /*
 380  * NM_LOCK: Create an unmonitored lock
 381  */
 382 static __be32
 383 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 384                                             struct nlm_res  *resp)
 385 {
 386         dprintk("lockd: NM_LOCK       called\n");
 387
 388         argp->monitor = 0;              /* just clean the monitor flag */
 389         return nlm4svc_proc_lock(rqstp, argp, resp);
 390 }
 391
 392 /*
 393  * FREE_ALL: Release all locks and shares held by client
 394  */
 395 static __be32
 396 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 397                                              void            *resp)
 398 {
 399         struct nlm_host *host;
 400
 401         /* Obtain client */
 402         if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
 403                 return rpc_success;
 404
 405         nlmsvc_free_host_resources(host);
 406         nlm_release_host(host);
 407         return rpc_success;
 408 }
 409
 410 /*
 411  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 412  */
 413 static __be32
 414 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 415                                               void              *resp)
 416 {
 417         dprintk("lockd: SM_NOTIFY     called\n");
 418
 419         if (!nlm_privileged_requester(rqstp)) {
 420                 char buf[RPC_MAX_ADDRBUFLEN];
 421                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 422                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 423                 return rpc_system_err;
 424         }
 425
 426         nlm_host_rebooted(argp);
 427         return rpc_success;
 428 }
 429
 430 /*
 431  * client sent a GRANTED_RES, let's remove the associated block
 432  */
 433 static __be32
 434 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 435                                                 void            *resp)
 436 {
 437         if (!nlmsvc_ops)
 438                 return rpc_success;
 439
 440         dprintk("lockd: GRANTED_RES   called\n");
 441
 442         nlmsvc_grant_reply(&argp->cookie, argp->status);
 443         return rpc_success;
 444 }
 445
 446
 447 /*
 448  * NLM Server procedures.
 449  */
 450
 451 #define nlm4svc_encode_norep    nlm4svc_encode_void
 452 #define nlm4svc_decode_norep    nlm4svc_decode_void
 453 #define nlm4svc_decode_testres  nlm4svc_decode_void
 454 #define nlm4svc_decode_lockres  nlm4svc_decode_void
 455 #define nlm4svc_decode_unlockres        nlm4svc_decode_void
 456 #define nlm4svc_decode_cancelres        nlm4svc_decode_void
 457 #define nlm4svc_decode_grantedres       nlm4svc_decode_void
 458
 459 #define nlm4svc_proc_none       nlm4svc_proc_null
 460 #define nlm4svc_proc_test_res   nlm4svc_proc_null
 461 #define nlm4svc_proc_lock_res   nlm4svc_proc_null
 462 #define nlm4svc_proc_cancel_res nlm4svc_proc_null
 463 #define nlm4svc_proc_unlock_res nlm4svc_proc_null
 464
 465 struct nlm_void                 { int dummy; };
 466
 467 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 468  { .pc_func     = (svc_procfunc) nlm4svc_proc_##name,   \
 469    .pc_decode   = (kxdrproc_t) nlm4svc_decode_##xargt,  \
 470    .pc_encode   = (kxdrproc_t) nlm4svc_encode_##xrest,  \
 471    .pc_release  = NULL,                                 \
 472    .pc_argsize  = sizeof(struct nlm_##argt),            \
 473    .pc_ressize  = sizeof(struct nlm_##rest),            \
 474    .pc_xdrressize = respsize,                           \
 475  }
 476 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 477 #define No      (1+1024/4)                              /* netobj */
 478 #define St      1                                       /* status */
 479 #define Rg      4                                       /* range (offset + length) */
 480 struct svc_procedure            nlmsvc_procedures4[] = {
 481   PROC(null,            void,           void,           void,   void, 1),
 482   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 483   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 484   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 485   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 486   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 487   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 488   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 489   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 490   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 491   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 492   PROC(test_res,        testres,        norep,          res,    void, 1),
 493   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 494   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 495   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 496   PROC(granted_res,     res,            norep,          res,    void, 1),
 497   /* statd callback */
 498   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 499   PROC(none,            void,           void,           void,   void, 0),
 500   PROC(none,            void,           void,           void,   void, 0),
 501   PROC(none,            void,           void,           void,   void, 0),
 502   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 503   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 504   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 505   PROC(free_all,        notify,         void,           args,   void, 1),
 506
 507 };