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/in.h>
  15 #include <linux/sunrpc/svc.h>
  16 #include <linux/sunrpc/clnt.h>
  17 #include <linux/nfsd/nfsd.h>
  18 #include <linux/lockd/lockd.h>
  19 #include <linux/lockd/share.h>
  20
  21 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  22
  23 /*
  24  * Obtain client and file from arguments
  25  */
  26 static __be32
  27 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  28                         struct nlm_host **hostp, struct nlm_file **filp)
  29 {
  30         struct nlm_host         *host = NULL;
  31         struct nlm_file         *file = NULL;
  32         struct nlm_lock         *lock = &argp->lock;
  33         __be32                  error = 0;
  34
  35         /* nfsd callbacks must have been installed for this procedure */
  36         if (!nlmsvc_ops)
  37                 return nlm_lck_denied_nolocks;
  38
  39         /* Obtain host handle */
  40         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  41          || (argp->monitor && nsm_monitor(host) < 0))
  42                 goto no_locks;
  43         *hostp = host;
  44
  45         /* Obtain file pointer. Not used by FREE_ALL call. */
  46         if (filp != NULL) {
  47                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  48                         goto no_locks;
  49                 *filp = file;
  50
  51                 /* Set up the missing parts of the file_lock structure */
  52                 lock->fl.fl_file  = file->f_file;
  53                 lock->fl.fl_owner = (fl_owner_t) host;
  54                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  55         }
  56
  57         return 0;
  58
  59 no_locks:
  60         nlm_release_host(host);
  61         if (error)
  62                 return error;
  63         return nlm_lck_denied_nolocks;
  64 }
  65
  66 /*
  67  * NULL: Test for presence of service
  68  */
  69 static __be32
  70 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  71 {
  72         dprintk("lockd: NULL          called\n");
  73         return rpc_success;
  74 }
  75
  76 /*
  77  * TEST: Check for conflicting lock
  78  */
  79 static __be32
  80 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
  81                                          struct nlm_res  *resp)
  82 {
  83         struct nlm_host *host;
  84         struct nlm_file *file;
  85         __be32 rc = rpc_success;
  86
  87         dprintk("lockd: TEST4        called\n");
  88         resp->cookie = argp->cookie;
  89
  90         /* Obtain client and file */
  91         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
  92                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
  93
  94         /* Now check for conflicting locks */
  95         resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
  96         if (resp->status == nlm_drop_reply)
  97                 rc = rpc_drop_reply;
  98         else
  99                 dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
 100
 101         nlm_release_host(host);
 102         nlm_release_file(file);
 103         return rc;
 104 }
 105
 106 static __be32
 107 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 108                                          struct nlm_res  *resp)
 109 {
 110         struct nlm_host *host;
 111         struct nlm_file *file;
 112         __be32 rc = rpc_success;
 113
 114         dprintk("lockd: LOCK          called\n");
 115
 116         resp->cookie = argp->cookie;
 117
 118         /* Obtain client and file */
 119         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 120                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 121
 122 #if 0
 123         /* If supplied state doesn't match current state, we assume it's
 124          * an old request that time-warped somehow. Any error return would
 125          * do in this case because it's irrelevant anyway.
 126          *
 127          * NB: We don't retrieve the remote host's state yet.
 128          */
 129         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 130                 resp->status = nlm_lck_denied_nolocks;
 131         } else
 132 #endif
 133
 134         /* Now try to lock the file */
 135         resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
 136                                         argp->block, &argp->cookie,
 137                                         argp->reclaim);
 138         if (resp->status == nlm_drop_reply)
 139                 rc = rpc_drop_reply;
 140         else
 141                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 142
 143         nlm_release_host(host);
 144         nlm_release_file(file);
 145         return rc;
 146 }
 147
 148 static __be32
 149 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 150                                            struct nlm_res  *resp)
 151 {
 152         struct nlm_host *host;
 153         struct nlm_file *file;
 154
 155         dprintk("lockd: CANCEL        called\n");
 156
 157         resp->cookie = argp->cookie;
 158
 159         /* Don't accept requests during grace period */
 160         if (locks_in_grace()) {
 161                 resp->status = nlm_lck_denied_grace_period;
 162                 return rpc_success;
 163         }
 164
 165         /* Obtain client and file */
 166         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 167                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 168
 169         /* Try to cancel request. */
 170         resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
 171
 172         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 173         nlm_release_host(host);
 174         nlm_release_file(file);
 175         return rpc_success;
 176 }
 177
 178 /*
 179  * UNLOCK: release a lock
 180  */
 181 static __be32
 182 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 183                                            struct nlm_res  *resp)
 184 {
 185         struct nlm_host *host;
 186         struct nlm_file *file;
 187
 188         dprintk("lockd: UNLOCK        called\n");
 189
 190         resp->cookie = argp->cookie;
 191
 192         /* Don't accept new lock requests during grace period */
 193         if (locks_in_grace()) {
 194                 resp->status = nlm_lck_denied_grace_period;
 195                 return rpc_success;
 196         }
 197
 198         /* Obtain client and file */
 199         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 200                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 201
 202         /* Now try to remove the lock */
 203         resp->status = nlmsvc_unlock(file, &argp->lock);
 204
 205         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 206         nlm_release_host(host);
 207         nlm_release_file(file);
 208         return rpc_success;
 209 }
 210
 211 /*
 212  * GRANTED: A server calls us to tell that a process' lock request
 213  * was granted
 214  */
 215 static __be32
 216 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 217                                             struct nlm_res  *resp)
 218 {
 219         resp->cookie = argp->cookie;
 220
 221         dprintk("lockd: GRANTED       called\n");
 222         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 223         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 224         return rpc_success;
 225 }
 226
 227 /*
 228  * This is the generic lockd callback for async RPC calls
 229  */
 230 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
 231 {
 232         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 233                         -task->tk_status);
 234 }
 235
 236 static void nlm4svc_callback_release(void *data)
 237 {
 238         lock_kernel();
 239         nlm_release_call(data);
 240         unlock_kernel();
 241 }
 242
 243 static const struct rpc_call_ops nlm4svc_callback_ops = {
 244         .rpc_call_done = nlm4svc_callback_exit,
 245         .rpc_release = nlm4svc_callback_release,
 246 };
 247
 248 /*
 249  * `Async' versions of the above service routines. They aren't really,
 250  * because we send the callback before the reply proper. I hope this
 251  * doesn't break any clients.
 252  */
 253 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 254                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 255 {
 256         struct nlm_host *host;
 257         struct nlm_rqst *call;
 258         __be32 stat;
 259
 260         host = nlmsvc_lookup_host(rqstp,
 261                                   argp->lock.caller,
 262                                   argp->lock.len);
 263         if (host == NULL)
 264                 return rpc_system_err;
 265
 266         call = nlm_alloc_call(host);
 267         if (call == NULL)
 268                 return rpc_system_err;
 269
 270         stat = func(rqstp, argp, &call->a_res);
 271         if (stat != 0) {
 272                 nlm_release_call(call);
 273                 return stat;
 274         }
 275
 276         call->a_flags = RPC_TASK_ASYNC;
 277         if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
 278                 return rpc_system_err;
 279         return rpc_success;
 280 }
 281
 282 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 283                                              void            *resp)
 284 {
 285         dprintk("lockd: TEST_MSG      called\n");
 286         return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
 287 }
 288
 289 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 290                                              void            *resp)
 291 {
 292         dprintk("lockd: LOCK_MSG      called\n");
 293         return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
 294 }
 295
 296 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 297                                                void            *resp)
 298 {
 299         dprintk("lockd: CANCEL_MSG    called\n");
 300         return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
 301 }
 302
 303 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 304                                                void            *resp)
 305 {
 306         dprintk("lockd: UNLOCK_MSG    called\n");
 307         return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
 308 }
 309
 310 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 311                                                 void            *resp)
 312 {
 313         dprintk("lockd: GRANTED_MSG   called\n");
 314         return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
 315 }
 316
 317 /*
 318  * SHARE: create a DOS share or alter existing share.
 319  */
 320 static __be32
 321 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 322                                           struct nlm_res  *resp)
 323 {
 324         struct nlm_host *host;
 325         struct nlm_file *file;
 326
 327         dprintk("lockd: SHARE         called\n");
 328
 329         resp->cookie = argp->cookie;
 330
 331         /* Don't accept new lock requests during grace period */
 332         if (locks_in_grace() && !argp->reclaim) {
 333                 resp->status = nlm_lck_denied_grace_period;
 334                 return rpc_success;
 335         }
 336
 337         /* Obtain client and file */
 338         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 339                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 340
 341         /* Now try to create the share */
 342         resp->status = nlmsvc_share_file(host, file, argp);
 343
 344         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 345         nlm_release_host(host);
 346         nlm_release_file(file);
 347         return rpc_success;
 348 }
 349
 350 /*
 351  * UNSHARE: Release a DOS share.
 352  */
 353 static __be32
 354 nlm4svc_proc_unshare(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: UNSHARE       called\n");
 361
 362         resp->cookie = argp->cookie;
 363
 364         /* Don't accept requests during grace period */
 365         if (locks_in_grace()) {
 366                 resp->status = nlm_lck_denied_grace_period;
 367                 return rpc_success;
 368         }
 369
 370         /* Obtain client and file */
 371         if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 372                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 373
 374         /* Now try to lock the file */
 375         resp->status = nlmsvc_unshare_file(host, file, argp);
 376
 377         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 378         nlm_release_host(host);
 379         nlm_release_file(file);
 380         return rpc_success;
 381 }
 382
 383 /*
 384  * NM_LOCK: Create an unmonitored lock
 385  */
 386 static __be32
 387 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 388                                             struct nlm_res  *resp)
 389 {
 390         dprintk("lockd: NM_LOCK       called\n");
 391
 392         argp->monitor = 0;              /* just clean the monitor flag */
 393         return nlm4svc_proc_lock(rqstp, argp, resp);
 394 }
 395
 396 /*
 397  * FREE_ALL: Release all locks and shares held by client
 398  */
 399 static __be32
 400 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 401                                              void            *resp)
 402 {
 403         struct nlm_host *host;
 404
 405         /* Obtain client */
 406         if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
 407                 return rpc_success;
 408
 409         nlmsvc_free_host_resources(host);
 410         nlm_release_host(host);
 411         return rpc_success;
 412 }
 413
 414 /*
 415  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 416  */
 417 static __be32
 418 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 419                                               void              *resp)
 420 {
 421         dprintk("lockd: SM_NOTIFY     called\n");
 422
 423         if (!nlm_privileged_requester(rqstp)) {
 424                 char buf[RPC_MAX_ADDRBUFLEN];
 425                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 426                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 427                 return rpc_system_err;
 428         }
 429
 430         nlm_host_rebooted(argp);
 431         return rpc_success;
 432 }
 433
 434 /*
 435  * client sent a GRANTED_RES, let's remove the associated block
 436  */
 437 static __be32
 438 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 439                                                 void            *resp)
 440 {
 441         if (!nlmsvc_ops)
 442                 return rpc_success;
 443
 444         dprintk("lockd: GRANTED_RES   called\n");
 445
 446         nlmsvc_grant_reply(&argp->cookie, argp->status);
 447         return rpc_success;
 448 }
 449
 450
 451 /*
 452  * NLM Server procedures.
 453  */
 454
 455 #define nlm4svc_encode_norep    nlm4svc_encode_void
 456 #define nlm4svc_decode_norep    nlm4svc_decode_void
 457 #define nlm4svc_decode_testres  nlm4svc_decode_void
 458 #define nlm4svc_decode_lockres  nlm4svc_decode_void
 459 #define nlm4svc_decode_unlockres        nlm4svc_decode_void
 460 #define nlm4svc_decode_cancelres        nlm4svc_decode_void
 461 #define nlm4svc_decode_grantedres       nlm4svc_decode_void
 462
 463 #define nlm4svc_proc_none       nlm4svc_proc_null
 464 #define nlm4svc_proc_test_res   nlm4svc_proc_null
 465 #define nlm4svc_proc_lock_res   nlm4svc_proc_null
 466 #define nlm4svc_proc_cancel_res nlm4svc_proc_null
 467 #define nlm4svc_proc_unlock_res nlm4svc_proc_null
 468
 469 struct nlm_void                 { int dummy; };
 470
 471 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 472  { .pc_func     = (svc_procfunc) nlm4svc_proc_##name,   \
 473    .pc_decode   = (kxdrproc_t) nlm4svc_decode_##xargt,  \
 474    .pc_encode   = (kxdrproc_t) nlm4svc_encode_##xrest,  \
 475    .pc_release  = NULL,                                 \
 476    .pc_argsize  = sizeof(struct nlm_##argt),            \
 477    .pc_ressize  = sizeof(struct nlm_##rest),            \
 478    .pc_xdrressize = respsize,                           \
 479  }
 480 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 481 #define No      (1+1024/4)                              /* netobj */
 482 #define St      1                                       /* status */
 483 #define Rg      4                                       /* range (offset + length) */
 484 struct svc_procedure            nlmsvc_procedures4[] = {
 485   PROC(null,            void,           void,           void,   void, 1),
 486   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 487   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 488   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 489   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 490   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 491   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 492   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 493   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 494   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 495   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 496   PROC(test_res,        testres,        norep,          res,    void, 1),
 497   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 498   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 499   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 500   PROC(granted_res,     res,            norep,          res,    void, 1),
 501   /* statd callback */
 502   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 503   PROC(none,            void,           void,           void,   void, 0),
 504   PROC(none,            void,           void,           void,   void, 0),
 505   PROC(none,            void,           void,           void,   void, 0),
 506   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 507   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 508   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 509   PROC(free_all,        notify,         void,           args,   void, 1),
 510
 511 };