source/smbd/files.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Files[] structure handling
   4    Copyright (C) Andrew Tridgell 1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 static int real_max_open_files;
  24
  25 #define VALID_FNUM(fnum)   (((fnum) >= 0) && ((fnum) < real_max_open_files))
  26
  27 #define FILE_HANDLE_OFFSET 0x1000
  28
  29 static struct bitmap *file_bmap;
  30
  31 static files_struct *Files;
  32
  33 /* a fsp to use when chaining */
  34 static files_struct *chain_fsp = NULL;
  35
  36 static int files_used;
  37
  38 /* A singleton cache to speed up searching by dev/inode. */
  39 static struct fsp_singleton_cache {
  40         files_struct *fsp;
  41         SMB_DEV_T dev;
  42         SMB_INO_T inode;
  43 } fsp_fi_cache;
  44
  45 /****************************************************************************
  46  Return a unique number identifying this fsp over the life of this pid.
  47 ****************************************************************************/
  48
  49 static unsigned long get_gen_count(void)
  50 {
  51         static unsigned long file_gen_counter;
  52
  53         if ((++file_gen_counter) == 0)
  54                 return ++file_gen_counter;
  55         return file_gen_counter;
  56 }
  57
  58 /****************************************************************************
  59  Find first available file slot.
  60 ****************************************************************************/
  61
  62 NTSTATUS file_new(connection_struct *conn, files_struct **result)
  63 {
  64         int i;
  65         static int first_file;
  66         files_struct *fsp;
  67
  68         /* we want to give out file handles differently on each new
  69            connection because of a common bug in MS clients where they try to
  70            reuse a file descriptor from an earlier smb connection. This code
  71            increases the chance that the errant client will get an error rather
  72            than causing corruption */
  73         if (first_file == 0) {
  74                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  75         }
  76
  77         /* TODO: Port the id-tree implementation from Samba4 */
  78
  79         i = bitmap_find(file_bmap, first_file);
  80         if (i == -1) {
  81                 DEBUG(0,("ERROR! Out of file structures\n"));
  82                 /* TODO: We have to unconditionally return a DOS error here,
  83                  * W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
  84                  * NTSTATUS negotiated */
  85                 return NT_STATUS_TOO_MANY_OPENED_FILES;
  86         }
  87
  88         fsp = SMB_MALLOC_P(files_struct);
  89         if (!fsp) {
  90                 return NT_STATUS_NO_MEMORY;
  91         }
  92
  93         ZERO_STRUCTP(fsp);
  94
  95         fsp->fh = SMB_MALLOC_P(struct fd_handle);
  96         if (!fsp->fh) {
  97                 SAFE_FREE(fsp);
  98                 return NT_STATUS_NO_MEMORY;
  99         }
 100
 101         ZERO_STRUCTP(fsp->fh);
 102
 103         fsp->fh->ref_count = 1;
 104         fsp->fh->fd = -1;
 105
 106         fsp->conn = conn;
 107         fsp->fh->file_id = get_gen_count();
 108         GetTimeOfDay(&fsp->open_time);
 109
 110         first_file = (i+1) % real_max_open_files;
 111
 112         bitmap_set(file_bmap, i);
 113         files_used++;
 114
 115         fsp->fnum = i + FILE_HANDLE_OFFSET;
 116         SMB_ASSERT(fsp->fnum < 65536);
 117
 118         string_set(&fsp->fsp_name,"");
 119
 120         DLIST_ADD(Files, fsp);
 121
 122         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 123                  i, fsp->fnum, files_used));
 124
 125         chain_fsp = fsp;
 126
 127         /* A new fsp invalidates a negative fsp_fi_cache. */
 128         if (fsp_fi_cache.fsp == NULL) {
 129                 ZERO_STRUCT(fsp_fi_cache);
 130         }
 131
 132         *result = fsp;
 133         return NT_STATUS_OK;
 134 }
 135
 136 /****************************************************************************
 137  Close all open files for a connection.
 138 ****************************************************************************/
 139
 140 void file_close_conn(connection_struct *conn)
 141 {
 142         files_struct *fsp, *next;
 143
 144         for (fsp=Files;fsp;fsp=next) {
 145                 next = fsp->next;
 146                 if (fsp->conn == conn) {
 147                         close_file(fsp,SHUTDOWN_CLOSE);
 148                 }
 149         }
 150 }
 151
 152 /****************************************************************************
 153  Close all open files for a pid and a vuid.
 154 ****************************************************************************/
 155
 156 void file_close_pid(uint16 smbpid, int vuid)
 157 {
 158         files_struct *fsp, *next;
 159
 160         for (fsp=Files;fsp;fsp=next) {
 161                 next = fsp->next;
 162                 if ((fsp->file_pid == smbpid) && (fsp->vuid == vuid)) {
 163                         close_file(fsp,SHUTDOWN_CLOSE);
 164                 }
 165         }
 166 }
 167
 168 /****************************************************************************
 169  Initialise file structures.
 170 ****************************************************************************/
 171
 172 #define MAX_OPEN_FUDGEFACTOR 20
 173
 174 void file_init(void)
 175 {
 176         int request_max_open_files = lp_max_open_files();
 177         int real_lim;
 178
 179         /*
 180          * Set the max_open files to be the requested
 181          * max plus a fudgefactor to allow for the extra
 182          * fd's we need such as log files etc...
 183          */
 184         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 185
 186         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 187
 188         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 189                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 190
 191         if(real_max_open_files != request_max_open_files) {
 192                 DEBUG(1,("file_init: Information only: requested %d \
 193 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 194         }
 195
 196         SMB_ASSERT(real_max_open_files > 100);
 197
 198         file_bmap = bitmap_allocate(real_max_open_files);
 199
 200         if (!file_bmap) {
 201                 exit_server("out of memory in file_init");
 202         }
 203
 204         /*
 205          * Ensure that pipe_handle_oppset is set correctly.
 206          */
 207         set_pipe_handle_offset(real_max_open_files);
 208 }
 209
 210 /****************************************************************************
 211  Close files open by a specified vuid.
 212 ****************************************************************************/
 213
 214 void file_close_user(int vuid)
 215 {
 216         files_struct *fsp, *next;
 217
 218         for (fsp=Files;fsp;fsp=next) {
 219                 next=fsp->next;
 220                 if (fsp->vuid == vuid) {
 221                         close_file(fsp,SHUTDOWN_CLOSE);
 222                 }
 223         }
 224 }
 225
 226 /****************************************************************************
 227  Debug to enumerate all open files in the smbd.
 228 ****************************************************************************/
 229
 230 void file_dump_open_table(void)
 231 {
 232         int count=0;
 233         files_struct *fsp;
 234
 235         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 236                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, fileid = %lu, dev = %x, inode = %.0f\n",
 237                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->file_id,
 238                         (unsigned int)fsp->dev, (double)fsp->inode ));
 239         }
 240 }
 241
 242 /****************************************************************************
 243  Find a fsp given a file descriptor.
 244 ****************************************************************************/
 245
 246 files_struct *file_find_fd(int fd)
 247 {
 248         int count=0;
 249         files_struct *fsp;
 250
 251         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 252                 if (fsp->fh->fd == fd) {
 253                         if (count > 10) {
 254                                 DLIST_PROMOTE(Files, fsp);
 255                         }
 256                         return fsp;
 257                 }
 258         }
 259
 260         return NULL;
 261 }
 262
 263 /****************************************************************************
 264  Find a fsp given a device, inode and file_id.
 265 ****************************************************************************/
 266
 267 files_struct *file_find_dif(SMB_DEV_T dev, SMB_INO_T inode, unsigned long file_id)
 268 {
 269         int count=0;
 270         files_struct *fsp;
 271
 272         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 273                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 274                 if (fsp->dev == dev &&
 275                     fsp->inode == inode &&
 276                     fsp->fh->file_id == file_id ) {
 277                         if (count > 10) {
 278                                 DLIST_PROMOTE(Files, fsp);
 279                         }
 280                         /* Paranoia check. */
 281                         if ((fsp->fh->fd == -1) &&
 282                             (fsp->oplock_type != NO_OPLOCK) &&
 283                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 284                                 DEBUG(0,("file_find_dif: file %s dev = %x, inode = %.0f, file_id = %u \
 285 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name, (unsigned int)fsp->dev,
 286                                                 (double)fsp->inode, (unsigned int)fsp->fh->file_id,
 287                                                 (unsigned int)fsp->oplock_type ));
 288                                 smb_panic("file_find_dif\n");
 289                         }
 290                         return fsp;
 291                 }
 292         }
 293
 294         return NULL;
 295 }
 296
 297 /****************************************************************************
 298  Check if an fsp still exists.
 299 ****************************************************************************/
 300
 301 files_struct *file_find_fsp(files_struct *orig_fsp)
 302 {
 303         files_struct *fsp;
 304
 305         for (fsp=Files;fsp;fsp=fsp->next) {
 306                 if (fsp == orig_fsp)
 307                         return fsp;
 308         }
 309
 310         return NULL;
 311 }
 312
 313 /****************************************************************************
 314  Find the first fsp given a device and inode.
 315  We use a singleton cache here to speed up searching from getfilepathinfo
 316  calls.
 317 ****************************************************************************/
 318
 319 files_struct *file_find_di_first(SMB_DEV_T dev, SMB_INO_T inode)
 320 {
 321         files_struct *fsp;
 322
 323         if (fsp_fi_cache.dev == dev && fsp_fi_cache.inode == inode) {
 324                 /* Positive or negative cache hit. */
 325                 return fsp_fi_cache.fsp;
 326         }
 327
 328         fsp_fi_cache.dev = dev;
 329         fsp_fi_cache.inode = inode;
 330
 331         for (fsp=Files;fsp;fsp=fsp->next) {
 332                 if ( fsp->fh->fd != -1 &&
 333                                 fsp->dev == dev &&
 334                                 fsp->inode == inode ) {
 335                         /* Setup positive cache. */
 336                         fsp_fi_cache.fsp = fsp;
 337                         return fsp;
 338                 }
 339         }
 340
 341         /* Setup negative cache. */
 342         fsp_fi_cache.fsp = NULL;
 343         return NULL;
 344 }
 345
 346 /****************************************************************************
 347  Find the next fsp having the same device and inode.
 348 ****************************************************************************/
 349
 350 files_struct *file_find_di_next(files_struct *start_fsp)
 351 {
 352         files_struct *fsp;
 353
 354         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 355                 if ( fsp->fh->fd != -1 &&
 356                                 fsp->dev == start_fsp->dev &&
 357                                 fsp->inode == start_fsp->inode )
 358                         return fsp;
 359         }
 360
 361         return NULL;
 362 }
 363
 364 /****************************************************************************
 365  Find a fsp that is open for printing.
 366 ****************************************************************************/
 367
 368 files_struct *file_find_print(void)
 369 {
 370         files_struct *fsp;
 371
 372         for (fsp=Files;fsp;fsp=fsp->next) {
 373                 if (fsp->print_file) {
 374                         return fsp;
 375                 }
 376         }
 377
 378         return NULL;
 379 }
 380
 381 /****************************************************************************
 382  Set a pending modtime across all files with a given dev/ino pair.
 383  Record the owner of that modtime.
 384 ****************************************************************************/
 385
 386 void fsp_set_pending_modtime(files_struct *tfsp, const struct timespec mod)
 387 {
 388         files_struct *fsp;
 389
 390         if (null_timespec(mod)) {
 391                 return;
 392         }
 393
 394         for (fsp = Files;fsp;fsp=fsp->next) {
 395                 if ( fsp->fh->fd != -1 &&
 396                                 fsp->dev == tfsp->dev &&
 397                                 fsp->inode == tfsp->inode ) {
 398                         fsp->pending_modtime = mod;
 399                         fsp->pending_modtime_owner = False;
 400                 }
 401         }
 402
 403         tfsp->pending_modtime_owner = True;
 404 }
 405
 406 /****************************************************************************
 407  Sync open files on a connection.
 408 ****************************************************************************/
 409
 410 void file_sync_all(connection_struct *conn)
 411 {
 412         files_struct *fsp, *next;
 413
 414         for (fsp=Files;fsp;fsp=next) {
 415                 next=fsp->next;
 416                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 417                         sync_file(conn, fsp, True /* write through */);
 418                 }
 419         }
 420 }
 421
 422 /****************************************************************************
 423  Free up a fsp.
 424 ****************************************************************************/
 425
 426 void file_free(files_struct *fsp)
 427 {
 428         DLIST_REMOVE(Files, fsp);
 429
 430         string_free(&fsp->fsp_name);
 431
 432         if (fsp->fake_file_handle) {
 433                 destroy_fake_file_handle(&fsp->fake_file_handle);
 434         }
 435
 436         if (fsp->fh->ref_count == 1) {
 437                 SAFE_FREE(fsp->fh);
 438         } else {
 439                 fsp->fh->ref_count--;
 440         }
 441
 442         if (fsp->notify) {
 443                 notify_remove(fsp->conn->notify_ctx, fsp);
 444                 TALLOC_FREE(fsp->notify);
 445         }
 446
 447         /* Ensure this event will never fire. */
 448         TALLOC_FREE(fsp->oplock_timeout);
 449
 450         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 451         files_used--;
 452
 453         DEBUG(5,("freed files structure %d (%d used)\n",
 454                  fsp->fnum, files_used));
 455
 456         /* this is paranoia, just in case someone tries to reuse the
 457            information */
 458         ZERO_STRUCTP(fsp);
 459
 460         if (fsp == chain_fsp) {
 461                 chain_fsp = NULL;
 462         }
 463
 464         /* Closing a file can invalidate the positive cache. */
 465         if (fsp == fsp_fi_cache.fsp) {
 466                 ZERO_STRUCT(fsp_fi_cache);
 467         }
 468
 469         SAFE_FREE(fsp);
 470 }
 471
 472 /****************************************************************************
 473  Get an fsp from a 16 bit fnum.
 474 ****************************************************************************/
 475
 476 files_struct *file_fnum(uint16 fnum)
 477 {
 478         files_struct *fsp;
 479         int count=0;
 480
 481         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 482                 if (fsp->fnum == fnum) {
 483                         if (count > 10) {
 484                                 DLIST_PROMOTE(Files, fsp);
 485                         }
 486                         return fsp;
 487                 }
 488         }
 489         return NULL;
 490 }
 491
 492 /****************************************************************************
 493  Get an fsp from a packet given the offset of a 16 bit fnum.
 494 ****************************************************************************/
 495
 496 files_struct *file_fsp(char *buf, int where)
 497 {
 498         files_struct *fsp;
 499
 500         if (chain_fsp) {
 501                 return chain_fsp;
 502         }
 503
 504         if (!buf) {
 505                 return NULL;
 506         }
 507
 508         fsp = file_fnum(SVAL(buf, where));
 509         if (fsp) {
 510                 chain_fsp = fsp;
 511         }
 512         return fsp;
 513 }
 514
 515 /****************************************************************************
 516  Reset the chained fsp - done at the start of a packet reply.
 517 ****************************************************************************/
 518
 519 void file_chain_reset(void)
 520 {
 521         chain_fsp = NULL;
 522 }
 523
 524 /****************************************************************************
 525  Duplicate the file handle part for a DOS or FCB open.
 526 ****************************************************************************/
 527
 528 NTSTATUS dup_file_fsp(files_struct *fsp,
 529                                 uint32 access_mask,
 530                                 uint32 share_access,
 531                                 uint32 create_options,
 532                                 files_struct **result)
 533 {
 534         NTSTATUS status;
 535         files_struct *dup_fsp;
 536
 537         status = file_new(fsp->conn, &dup_fsp);
 538
 539         if (!NT_STATUS_IS_OK(status)) {
 540                 return status;
 541         }
 542
 543         SAFE_FREE(dup_fsp->fh);
 544
 545         dup_fsp->fh = fsp->fh;
 546         dup_fsp->fh->ref_count++;
 547
 548         dup_fsp->dev = fsp->dev;
 549         dup_fsp->inode = fsp->inode;
 550         dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
 551         dup_fsp->mode = fsp->mode;
 552         dup_fsp->file_pid = fsp->file_pid;
 553         dup_fsp->vuid = fsp->vuid;
 554         dup_fsp->open_time = fsp->open_time;
 555         dup_fsp->access_mask = access_mask;
 556         dup_fsp->share_access = share_access;
 557         dup_fsp->pending_modtime_owner = fsp->pending_modtime_owner;
 558         dup_fsp->pending_modtime = fsp->pending_modtime;
 559         dup_fsp->last_write_time = fsp->last_write_time;
 560         dup_fsp->oplock_type = fsp->oplock_type;
 561         dup_fsp->can_lock = fsp->can_lock;
 562         dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 563         if (!CAN_WRITE(fsp->conn)) {
 564                 dup_fsp->can_write = False;
 565         } else {
 566                 dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 567         }
 568         dup_fsp->print_file = fsp->print_file;
 569         dup_fsp->modified = fsp->modified;
 570         dup_fsp->is_directory = fsp->is_directory;
 571         dup_fsp->is_stat = fsp->is_stat;
 572         dup_fsp->aio_write_behind = fsp->aio_write_behind;
 573         string_set(&dup_fsp->fsp_name,fsp->fsp_name);
 574
 575         *result = dup_fsp;
 576         return NT_STATUS_OK;
 577 }