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                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  72                         goto no_locks;
  73                 *filp = file;
  74
  75                 /* Set up the missing parts of the file_lock structure */
  76                 lock->fl.fl_file  = file->f_file;
  77                 lock->fl.fl_owner = (fl_owner_t) host;
  78                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  79         }
  80
  81         return 0;
  82
  83 no_locks:
  84         nlmsvc_release_host(host);
  85         if (error)
  86                 return error;
  87         return nlm_lck_denied_nolocks;
  88 }
  89
  90 /*
  91  * NULL: Test for presence of service
  92  */
  93 static __be32
  94 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  95 {
  96         dprintk("lockd: NULL          called\n");
  97         return rpc_success;
  98 }
  99
 100 /*
 101  * TEST: Check for conflicting lock
 102  */
 103 static __be32
 104 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
 105                                          struct nlm_res  *resp)
 106 {
 107         struct nlm_host *host;
 108         struct nlm_file *file;
 109         __be32 rc = rpc_success;
 110
 111         dprintk("lockd: TEST          called\n");
 112         resp->cookie = argp->cookie;
 113
 114         /* Obtain client and file */
 115         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 116                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 117
 118         /* Now check for conflicting locks */
 119         resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
 120         if (resp->status == nlm_drop_reply)
 121                 rc = rpc_drop_reply;
 122         else
 123                 dprintk("lockd: TEST          status %d vers %d\n",
 124                         ntohl(resp->status), rqstp->rq_vers);
 125
 126         nlmsvc_release_host(host);
 127         nlm_release_file(file);
 128         return rc;
 129 }
 130
 131 static __be32
 132 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 133                                          struct nlm_res  *resp)
 134 {
 135         struct nlm_host *host;
 136         struct nlm_file *file;
 137         __be32 rc = rpc_success;
 138
 139         dprintk("lockd: LOCK          called\n");
 140
 141         resp->cookie = argp->cookie;
 142
 143         /* Obtain client and file */
 144         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 145                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 146
 147 #if 0
 148         /* If supplied state doesn't match current state, we assume it's
 149          * an old request that time-warped somehow. Any error return would
 150          * do in this case because it's irrelevant anyway.
 151          *
 152          * NB: We don't retrieve the remote host's state yet.
 153          */
 154         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 155                 resp->status = nlm_lck_denied_nolocks;
 156         } else
 157 #endif
 158
 159         /* Now try to lock the file */
 160         resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 161                                                argp->block, &argp->cookie,
 162                                                argp->reclaim));
 163         if (resp->status == nlm_drop_reply)
 164                 rc = rpc_drop_reply;
 165         else
 166                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 167
 168         nlmsvc_release_host(host);
 169         nlm_release_file(file);
 170         return rc;
 171 }
 172
 173 static __be32
 174 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 175                                            struct nlm_res  *resp)
 176 {
 177         struct nlm_host *host;
 178         struct nlm_file *file;
 179         struct net *net = SVC_NET(rqstp);
 180
 181         dprintk("lockd: CANCEL        called\n");
 182
 183         resp->cookie = argp->cookie;
 184
 185         /* Don't accept requests during grace period */
 186         if (locks_in_grace(net)) {
 187                 resp->status = nlm_lck_denied_grace_period;
 188                 return rpc_success;
 189         }
 190
 191         /* Obtain client and file */
 192         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 193                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 194
 195         /* Try to cancel request. */
 196         resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
 197
 198         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 199         nlmsvc_release_host(host);
 200         nlm_release_file(file);
 201         return rpc_success;
 202 }
 203
 204 /*
 205  * UNLOCK: release a lock
 206  */
 207 static __be32
 208 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 209                                            struct nlm_res  *resp)
 210 {
 211         struct nlm_host *host;
 212         struct nlm_file *file;
 213         struct net *net = SVC_NET(rqstp);
 214
 215         dprintk("lockd: UNLOCK        called\n");
 216
 217         resp->cookie = argp->cookie;
 218
 219         /* Don't accept new lock requests during grace period */
 220         if (locks_in_grace(net)) {
 221                 resp->status = nlm_lck_denied_grace_period;
 222                 return rpc_success;
 223         }
 224
 225         /* Obtain client and file */
 226         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 227                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 228
 229         /* Now try to remove the lock */
 230         resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
 231
 232         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 233         nlmsvc_release_host(host);
 234         nlm_release_file(file);
 235         return rpc_success;
 236 }
 237
 238 /*
 239  * GRANTED: A server calls us to tell that a process' lock request
 240  * was granted
 241  */
 242 static __be32
 243 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 244                                             struct nlm_res  *resp)
 245 {
 246         resp->cookie = argp->cookie;
 247
 248         dprintk("lockd: GRANTED       called\n");
 249         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 250         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 251         return rpc_success;
 252 }
 253
 254 /*
 255  * This is the generic lockd callback for async RPC calls
 256  */
 257 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 258 {
 259         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 260                         -task->tk_status);
 261 }
 262
 263 void nlmsvc_release_call(struct nlm_rqst *call)
 264 {
 265         if (!atomic_dec_and_test(&call->a_count))
 266                 return;
 267         nlmsvc_release_host(call->a_host);
 268         kfree(call);
 269 }
 270
 271 static void nlmsvc_callback_release(void *data)
 272 {
 273         nlmsvc_release_call(data);
 274 }
 275
 276 static const struct rpc_call_ops nlmsvc_callback_ops = {
 277         .rpc_call_done = nlmsvc_callback_exit,
 278         .rpc_release = nlmsvc_callback_release,
 279 };
 280
 281 /*
 282  * `Async' versions of the above service routines. They aren't really,
 283  * because we send the callback before the reply proper. I hope this
 284  * doesn't break any clients.
 285  */
 286 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 287                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 288 {
 289         struct nlm_host *host;
 290         struct nlm_rqst *call;
 291         __be32 stat;
 292
 293         host = nlmsvc_lookup_host(rqstp,
 294                                   argp->lock.caller,
 295                                   argp->lock.len);
 296         if (host == NULL)
 297                 return rpc_system_err;
 298
 299         call = nlm_alloc_call(host);
 300         if (call == NULL)
 301                 return rpc_system_err;
 302
 303         stat = func(rqstp, argp, &call->a_res);
 304         if (stat != 0) {
 305                 nlmsvc_release_call(call);
 306                 return stat;
 307         }
 308
 309         call->a_flags = RPC_TASK_ASYNC;
 310         if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 311                 return rpc_system_err;
 312         return rpc_success;
 313 }
 314
 315 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 316                                              void            *resp)
 317 {
 318         dprintk("lockd: TEST_MSG      called\n");
 319         return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
 320 }
 321
 322 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 323                                              void            *resp)
 324 {
 325         dprintk("lockd: LOCK_MSG      called\n");
 326         return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
 327 }
 328
 329 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 330                                                void            *resp)
 331 {
 332         dprintk("lockd: CANCEL_MSG    called\n");
 333         return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
 334 }
 335
 336 static __be32
 337 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 338                                                void            *resp)
 339 {
 340         dprintk("lockd: UNLOCK_MSG    called\n");
 341         return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
 342 }
 343
 344 static __be32
 345 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 346                                                 void            *resp)
 347 {
 348         dprintk("lockd: GRANTED_MSG   called\n");
 349         return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
 350 }
 351
 352 /*
 353  * SHARE: create a DOS share or alter existing share.
 354  */
 355 static __be32
 356 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 357                                           struct nlm_res  *resp)
 358 {
 359         struct nlm_host *host;
 360         struct nlm_file *file;
 361
 362         dprintk("lockd: SHARE         called\n");
 363
 364         resp->cookie = argp->cookie;
 365
 366         /* Don't accept new lock requests during grace period */
 367         if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
 368                 resp->status = nlm_lck_denied_grace_period;
 369                 return rpc_success;
 370         }
 371
 372         /* Obtain client and file */
 373         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 374                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 375
 376         /* Now try to create the share */
 377         resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 378
 379         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 380         nlmsvc_release_host(host);
 381         nlm_release_file(file);
 382         return rpc_success;
 383 }
 384
 385 /*
 386  * UNSHARE: Release a DOS share.
 387  */
 388 static __be32
 389 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 390                                             struct nlm_res  *resp)
 391 {
 392         struct nlm_host *host;
 393         struct nlm_file *file;
 394
 395         dprintk("lockd: UNSHARE       called\n");
 396
 397         resp->cookie = argp->cookie;
 398
 399         /* Don't accept requests during grace period */
 400         if (locks_in_grace(SVC_NET(rqstp))) {
 401                 resp->status = nlm_lck_denied_grace_period;
 402                 return rpc_success;
 403         }
 404
 405         /* Obtain client and file */
 406         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 407                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 408
 409         /* Now try to unshare the file */
 410         resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 411
 412         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 413         nlmsvc_release_host(host);
 414         nlm_release_file(file);
 415         return rpc_success;
 416 }
 417
 418 /*
 419  * NM_LOCK: Create an unmonitored lock
 420  */
 421 static __be32
 422 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 423                                             struct nlm_res  *resp)
 424 {
 425         dprintk("lockd: NM_LOCK       called\n");
 426
 427         argp->monitor = 0;              /* just clean the monitor flag */
 428         return nlmsvc_proc_lock(rqstp, argp, resp);
 429 }
 430
 431 /*
 432  * FREE_ALL: Release all locks and shares held by client
 433  */
 434 static __be32
 435 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 436                                              void            *resp)
 437 {
 438         struct nlm_host *host;
 439
 440         /* Obtain client */
 441         if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 442                 return rpc_success;
 443
 444         nlmsvc_free_host_resources(host);
 445         nlmsvc_release_host(host);
 446         return rpc_success;
 447 }
 448
 449 /*
 450  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 451  */
 452 static __be32
 453 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 454                                               void              *resp)
 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         nlm_host_rebooted(argp);
 466         return rpc_success;
 467 }
 468
 469 /*
 470  * client sent a GRANTED_RES, let's remove the associated block
 471  */
 472 static __be32
 473 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 474                                                 void            *resp)
 475 {
 476         if (!nlmsvc_ops)
 477                 return rpc_success;
 478
 479         dprintk("lockd: GRANTED_RES   called\n");
 480
 481         nlmsvc_grant_reply(&argp->cookie, argp->status);
 482         return rpc_success;
 483 }
 484
 485 /*
 486  * NLM Server procedures.
 487  */
 488
 489 #define nlmsvc_encode_norep     nlmsvc_encode_void
 490 #define nlmsvc_decode_norep     nlmsvc_decode_void
 491 #define nlmsvc_decode_testres   nlmsvc_decode_void
 492 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 493 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 494 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 495 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 496
 497 #define nlmsvc_proc_none        nlmsvc_proc_null
 498 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 499 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 500 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 501 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 502
 503 struct nlm_void                 { int dummy; };
 504
 505 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 506  { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 507    .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 508    .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 509    .pc_release  = NULL,                                 \
 510    .pc_argsize  = sizeof(struct nlm_##argt),            \
 511    .pc_ressize  = sizeof(struct nlm_##rest),            \
 512    .pc_xdrressize = respsize,                           \
 513  }
 514
 515 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 516 #define St      1                               /* status */
 517 #define No      (1+1024/4)                      /* Net Obj */
 518 #define Rg      2                               /* range - offset + size */
 519
 520 struct svc_procedure            nlmsvc_procedures[] = {
 521   PROC(null,            void,           void,           void,   void, 1),
 522   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 523   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 524   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 525   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 526   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 527   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 528   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 529   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 530   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 531   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 532   PROC(test_res,        testres,        norep,          res,    void, 1),
 533   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 534   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 535   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 536   PROC(granted_res,     res,            norep,          res,    void, 1),
 537   /* statd callback */
 538   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 539   PROC(none,            void,           void,           void,   void, 1),
 540   PROC(none,            void,           void,           void,   void, 1),
 541   PROC(none,            void,           void,           void,   void, 1),
 542   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 543   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 544   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 545   PROC(free_all,        notify,         void,           args,   void, 0),
 546
 547 };