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/smp_lock.h>
  13 #include <linux/lockd/lockd.h>
  14 #include <linux/lockd/share.h>
  15
  16 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  17
  18 /*
  19  * Obtain client and file from arguments
  20  */
  21 static __be32
  22 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  23                         struct nlm_host **hostp, struct nlm_file **filp)
  24 {
  25         struct nlm_host         *host = NULL;
  26         struct nlm_file         *file = NULL;
  27         struct nlm_lock         *lock = &argp->lock;
  28         __be32                  error = 0;
  29
  30         /* nfsd callbacks must have been installed for this procedure */
  31         if (!nlmsvc_ops)
  32                 return nlm_lck_denied_nolocks;
  33
  34         /* Obtain host handle */
  35         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  36          || (argp->monitor && nsm_monitor(host) < 0))
  37                 goto no_locks;
  38         *hostp = host;
  39
  40         /* Obtain file pointer. Not used by FREE_ALL call. */
  41         if (filp != NULL) {
  42                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  43                         goto no_locks;
  44                 *filp = file;
  45
  46                 /* Set up the missing parts of the file_lock structure */
  47                 lock->fl.fl_file  = file->f_file;
  48                 lock->fl.fl_owner = (fl_owner_t) host;
  49                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  50         }
  51
  52         return 0;
  53
  54 no_locks:
  55         nlm_release_host(host);
  56         if (error)
  57                 return error;
  58         return nlm_lck_denied_nolocks;
  59 }
  60
  61 /*
  62  * NULL: Test for presence of service
  63  */
  64 static __be32
  65 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  66 {
  67         dprintk("lockd: NULL          called\n");
  68         return rpc_success;
  69 }
  70
  71 /*
  72  * TEST: Check for conflicting lock
  73  */
  74 static __be32
  75 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
  76                                          struct nlm_res  *resp)
  77 {
  78         struct nlm_host *host;
  79         struct nlm_file *file;
  80         __be32 rc = rpc_success;
  81
  82         dprintk("lockd: TEST4        called\n");
  83         resp->cookie = argp->cookie;
  84
  85         /* Obtain client and file */
  86         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
  87                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
  88
  89         /* Now check for conflicting locks */
  90         resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
  91         if (resp->status == nlm_drop_reply)
  92                 rc = rpc_drop_reply;
  93         else
  94                 dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
  95
  96         nlm_release_host(host);
  97         nlm_release_file(file);
  98         return rc;
  99 }
 100
 101 static __be32
 102 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 103                                          struct nlm_res  *resp)
 104 {
 105         struct nlm_host *host;
 106         struct nlm_file *file;
 107         __be32 rc = rpc_success;
 108
 109         dprintk("lockd: LOCK          called\n");
 110
 111         resp->cookie = argp->cookie;
 112
 113         /* Obtain client and file */
 114         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 115                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 116
 117 #if 0
 118         /* If supplied state doesn't match current state, we assume it's
 119          * an old request that time-warped somehow. Any error return would
 120          * do in this case because it's irrelevant anyway.
 121          *
 122          * NB: We don't retrieve the remote host's state yet.
 123          */
 124         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 125                 resp->status = nlm_lck_denied_nolocks;
 126         } else
 127 #endif
 128
 129         /* Now try to lock the file */
 130         resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
 131                                         argp->block, &argp->cookie,
 132                                         argp->reclaim);
 133         if (resp->status == nlm_drop_reply)
 134                 rc = rpc_drop_reply;
 135         else
 136                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 137
 138         nlm_release_host(host);
 139         nlm_release_file(file);
 140         return rc;
 141 }
 142
 143 static __be32
 144 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 145                                            struct nlm_res  *resp)
 146 {
 147         struct nlm_host *host;
 148         struct nlm_file *file;
 149
 150         dprintk("lockd: CANCEL        called\n");
 151
 152         resp->cookie = argp->cookie;
 153
 154         /* Don't accept requests during grace period */
 155         if (locks_in_grace()) {
 156                 resp->status = nlm_lck_denied_grace_period;
 157                 return rpc_success;
 158         }
 159
 160         /* Obtain client and file */
 161         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 162                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 163
 164         /* Try to cancel request. */
 165         resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
 166
 167         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 168         nlm_release_host(host);
 169         nlm_release_file(file);
 170         return rpc_success;
 171 }
 172
 173 /*
 174  * UNLOCK: release a lock
 175  */
 176 static __be32
 177 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 178                                            struct nlm_res  *resp)
 179 {
 180         struct nlm_host *host;
 181         struct nlm_file *file;
 182
 183         dprintk("lockd: UNLOCK        called\n");
 184
 185         resp->cookie = argp->cookie;
 186
 187         /* Don't accept new lock requests during grace period */
 188         if (locks_in_grace()) {
 189                 resp->status = nlm_lck_denied_grace_period;
 190                 return rpc_success;
 191         }
 192
 193         /* Obtain client and file */
 194         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 195                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 196
 197         /* Now try to remove the lock */
 198         resp->status = nlmsvc_unlock(file, &argp->lock);
 199
 200         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 201         nlm_release_host(host);
 202         nlm_release_file(file);
 203         return rpc_success;
 204 }
 205
 206 /*
 207  * GRANTED: A server calls us to tell that a process' lock request
 208  * was granted
 209  */
 210 static __be32
 211 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 212                                             struct nlm_res  *resp)
 213 {
 214         resp->cookie = argp->cookie;
 215
 216         dprintk("lockd: GRANTED       called\n");
 217         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 218         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 219         return rpc_success;
 220 }
 221
 222 /*
 223  * This is the generic lockd callback for async RPC calls
 224  */
 225 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
 226 {
 227         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 228                         -task->tk_status);
 229 }
 230
 231 static void nlm4svc_callback_release(void *data)
 232 {
 233         lock_kernel();
 234         nlm_release_call(data);
 235         unlock_kernel();
 236 }
 237
 238 static const struct rpc_call_ops nlm4svc_callback_ops = {
 239         .rpc_call_done = nlm4svc_callback_exit,
 240         .rpc_release = nlm4svc_callback_release,
 241 };
 242
 243 /*
 244  * `Async' versions of the above service routines. They aren't really,
 245  * because we send the callback before the reply proper. I hope this
 246  * doesn't break any clients.
 247  */
 248 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 249                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 250 {
 251         struct nlm_host *host;
 252         struct nlm_rqst *call;
 253         __be32 stat;
 254
 255         host = nlmsvc_lookup_host(rqstp,
 256                                   argp->lock.caller,
 257                                   argp->lock.len);
 258         if (host == NULL)
 259                 return rpc_system_err;
 260
 261         call = nlm_alloc_call(host);
 262         if (call == NULL)
 263                 return rpc_system_err;
 264
 265         stat = func(rqstp, argp, &call->a_res);
 266         if (stat != 0) {
 267                 nlm_release_call(call);
 268                 return stat;
 269         }
 270
 271         call->a_flags = RPC_TASK_ASYNC;
 272         if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
 273                 return rpc_system_err;
 274         return rpc_success;
 275 }
 276
 277 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 278                                              void            *resp)
 279 {
 280         dprintk("lockd: TEST_MSG      called\n");
 281         return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
 282 }
 283
 284 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 285                                              void            *resp)
 286 {
 287         dprintk("lockd: LOCK_MSG      called\n");
 288         return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
 289 }
 290
 291 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 292                                                void            *resp)
 293 {
 294         dprintk("lockd: CANCEL_MSG    called\n");
 295         return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
 296 }
 297
 298 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 299                                                void            *resp)
 300 {
 301         dprintk("lockd: UNLOCK_MSG    called\n");
 302         return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
 303 }
 304
 305 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 306                                                 void            *resp)
 307 {
 308         dprintk("lockd: GRANTED_MSG   called\n");
 309         return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
 310 }
 311
 312 /*
 313  * SHARE: create a DOS share or alter existing share.
 314  */
 315 static __be32
 316 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 317                                           struct nlm_res  *resp)
 318 {
 319         struct nlm_host *host;
 320         struct nlm_file *file;
 321
 322         dprintk("lockd: SHARE         called\n");
 323
 324         resp->cookie = argp->cookie;
 325
 326         /* Don't accept new lock requests during grace period */
 327         if (locks_in_grace() && !argp->reclaim) {
 328                 resp->status = nlm_lck_denied_grace_period;
 329                 return rpc_success;
 330         }
 331
 332         /* Obtain client and file */
 333         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 334                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 335
 336         /* Now try to create the share */
 337         resp->status = nlmsvc_share_file(host, file, argp);
 338
 339         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 340         nlm_release_host(host);
 341         nlm_release_file(file);
 342         return rpc_success;
 343 }
 344
 345 /*
 346  * UNSHARE: Release a DOS share.
 347  */
 348 static __be32
 349 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 350                                             struct nlm_res  *resp)
 351 {
 352         struct nlm_host *host;
 353         struct nlm_file *file;
 354
 355         dprintk("lockd: UNSHARE       called\n");
 356
 357         resp->cookie = argp->cookie;
 358
 359         /* Don't accept requests during grace period */
 360         if (locks_in_grace()) {
 361                 resp->status = nlm_lck_denied_grace_period;
 362                 return rpc_success;
 363         }
 364
 365         /* Obtain client and file */
 366         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 367                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 368
 369         /* Now try to lock the file */
 370         resp->status = nlmsvc_unshare_file(host, file, argp);
 371
 372         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 373         nlm_release_host(host);
 374         nlm_release_file(file);
 375         return rpc_success;
 376 }
 377
 378 /*
 379  * NM_LOCK: Create an unmonitored lock
 380  */
 381 static __be32
 382 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 383                                             struct nlm_res  *resp)
 384 {
 385         dprintk("lockd: NM_LOCK       called\n");
 386
 387         argp->monitor = 0;              /* just clean the monitor flag */
 388         return nlm4svc_proc_lock(rqstp, argp, resp);
 389 }
 390
 391 /*
 392  * FREE_ALL: Release all locks and shares held by client
 393  */
 394 static __be32
 395 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 396                                              void            *resp)
 397 {
 398         struct nlm_host *host;
 399
 400         /* Obtain client */
 401         if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
 402                 return rpc_success;
 403
 404         nlmsvc_free_host_resources(host);
 405         nlm_release_host(host);
 406         return rpc_success;
 407 }
 408
 409 /*
 410  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 411  */
 412 static __be32
 413 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 414                                               void              *resp)
 415 {
 416         dprintk("lockd: SM_NOTIFY     called\n");
 417
 418         if (!nlm_privileged_requester(rqstp)) {
 419                 char buf[RPC_MAX_ADDRBUFLEN];
 420                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 421                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 422                 return rpc_system_err;
 423         }
 424
 425         nlm_host_rebooted(argp);
 426         return rpc_success;
 427 }
 428
 429 /*
 430  * client sent a GRANTED_RES, let's remove the associated block
 431  */
 432 static __be32
 433 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 434                                                 void            *resp)
 435 {
 436         if (!nlmsvc_ops)
 437                 return rpc_success;
 438
 439         dprintk("lockd: GRANTED_RES   called\n");
 440
 441         nlmsvc_grant_reply(&argp->cookie, argp->status);
 442         return rpc_success;
 443 }
 444
 445
 446 /*
 447  * NLM Server procedures.
 448  */
 449
 450 #define nlm4svc_encode_norep    nlm4svc_encode_void
 451 #define nlm4svc_decode_norep    nlm4svc_decode_void
 452 #define nlm4svc_decode_testres  nlm4svc_decode_void
 453 #define nlm4svc_decode_lockres  nlm4svc_decode_void
 454 #define nlm4svc_decode_unlockres        nlm4svc_decode_void
 455 #define nlm4svc_decode_cancelres        nlm4svc_decode_void
 456 #define nlm4svc_decode_grantedres       nlm4svc_decode_void
 457
 458 #define nlm4svc_proc_none       nlm4svc_proc_null
 459 #define nlm4svc_proc_test_res   nlm4svc_proc_null
 460 #define nlm4svc_proc_lock_res   nlm4svc_proc_null
 461 #define nlm4svc_proc_cancel_res nlm4svc_proc_null
 462 #define nlm4svc_proc_unlock_res nlm4svc_proc_null
 463
 464 struct nlm_void                 { int dummy; };
 465
 466 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 467  { .pc_func     = (svc_procfunc) nlm4svc_proc_##name,   \
 468    .pc_decode   = (kxdrproc_t) nlm4svc_decode_##xargt,  \
 469    .pc_encode   = (kxdrproc_t) nlm4svc_encode_##xrest,  \
 470    .pc_release  = NULL,                                 \
 471    .pc_argsize  = sizeof(struct nlm_##argt),            \
 472    .pc_ressize  = sizeof(struct nlm_##rest),            \
 473    .pc_xdrressize = respsize,                           \
 474  }
 475 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 476 #define No      (1+1024/4)                              /* netobj */
 477 #define St      1                                       /* status */
 478 #define Rg      4                                       /* range (offset + length) */
 479 struct svc_procedure            nlmsvc_procedures4[] = {
 480   PROC(null,            void,           void,           void,   void, 1),
 481   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 482   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 483   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 484   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 485   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 486   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 487   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 488   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 489   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 490   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 491   PROC(test_res,        testres,        norep,          res,    void, 1),
 492   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 493   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 494   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 495   PROC(granted_res,     res,            norep,          res,    void, 1),
 496   /* statd callback */
 497   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 498   PROC(none,            void,           void,           void,   void, 0),
 499   PROC(none,            void,           void,           void,   void, 0),
 500   PROC(none,            void,           void,           void,   void, 0),
 501   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 502   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 503   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 504   PROC(free_all,        notify,         void,           args,   void, 1),
 505
 506 };