source3/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 /* a fsp to use to save when breaking an oplock. */
  36 static files_struct *oplock_save_chain_fsp = NULL;
  37
  38 static int files_used;
  39
  40 /* A singleton cache to speed up searching by dev/inode. */
  41 static struct fsp_singleton_cache {
  42         files_struct *fsp;
  43         SMB_DEV_T dev;
  44         SMB_INO_T inode;
  45 } fsp_fi_cache;
  46
  47 /****************************************************************************
  48  Return a unique number identifying this fsp over the life of this pid.
  49 ****************************************************************************/
  50
  51 static unsigned long get_gen_count(void)
  52 {
  53         static unsigned long file_gen_counter;
  54
  55         if ((++file_gen_counter) == 0)
  56                 return ++file_gen_counter;
  57         return file_gen_counter;
  58 }
  59
  60 /****************************************************************************
  61  Find first available file slot.
  62 ****************************************************************************/
  63
  64 files_struct *file_new(connection_struct *conn)
  65 {
  66         int i;
  67         static int first_file;
  68         files_struct *fsp, *next;
  69
  70         /* we want to give out file handles differently on each new
  71            connection because of a common bug in MS clients where they try to
  72            reuse a file descriptor from an earlier smb connection. This code
  73            increases the chance that the errant client will get an error rather
  74            than causing corruption */
  75         if (first_file == 0) {
  76                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  77         }
  78
  79         i = bitmap_find(file_bmap, first_file);
  80         if (i == -1) {
  81                 /*
  82                  * Before we give up, go through the open files
  83                  * and see if there are any files opened with a
  84                  * batch oplock. If so break the oplock and then
  85                  * re-use that entry (if it becomes closed).
  86                  * This may help as NT/95 clients tend to keep
  87                  * files batch oplocked for quite a long time
  88                  * after they have finished with them.
  89                  */
  90                 for (fsp=Files;fsp;fsp=next) {
  91                         next=fsp->next;
  92                         if (attempt_close_oplocked_file(fsp)) {
  93                                 return file_new(conn);
  94                         }
  95                 }
  96
  97                 DEBUG(0,("ERROR! Out of file structures\n"));
  98                 set_saved_error_triple(ERRSRV, ERRnofids, NT_STATUS_TOO_MANY_OPENED_FILES);
  99                 return NULL;
 100         }
 101
 102         fsp = SMB_MALLOC_P(files_struct);
 103         if (!fsp) {
 104                 set_saved_error_triple(ERRDOS, ERRnomem, NT_STATUS_NO_MEMORY);
 105                 return NULL;
 106         }
 107
 108         ZERO_STRUCTP(fsp);
 109
 110         fsp->fh = SMB_MALLOC_P(struct fd_handle);
 111         if (!fsp->fh) {
 112                 SAFE_FREE(fsp);
 113                 set_saved_error_triple(ERRDOS, ERRnomem, NT_STATUS_NO_MEMORY);
 114                 return NULL;
 115         }
 116
 117         ZERO_STRUCTP(fsp->fh);
 118
 119         fsp->fh->ref_count = 1;
 120         fsp->fh->fd = -1;
 121
 122         fsp->conn = conn;
 123         fsp->file_id = get_gen_count();
 124         GetTimeOfDay(&fsp->open_time);
 125
 126         first_file = (i+1) % real_max_open_files;
 127
 128         bitmap_set(file_bmap, i);
 129         files_used++;
 130
 131         fsp->fnum = i + FILE_HANDLE_OFFSET;
 132         SMB_ASSERT(fsp->fnum < 65536);
 133
 134         string_set(&fsp->fsp_name,"");
 135
 136         DLIST_ADD(Files, fsp);
 137
 138         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 139                  i, fsp->fnum, files_used));
 140
 141         chain_fsp = fsp;
 142
 143         /* A new fsp invalidates a negative fsp_fi_cache. */
 144         if (fsp_fi_cache.fsp == NULL) {
 145                 ZERO_STRUCT(fsp_fi_cache);
 146         }
 147
 148         return fsp;
 149 }
 150
 151 /****************************************************************************
 152  Close all open files for a connection.
 153 ****************************************************************************/
 154
 155 void file_close_conn(connection_struct *conn)
 156 {
 157         files_struct *fsp, *next;
 158
 159         for (fsp=Files;fsp;fsp=next) {
 160                 next = fsp->next;
 161                 if (fsp->conn == conn) {
 162                         close_file(fsp,False);
 163                 }
 164         }
 165 }
 166
 167 /****************************************************************************
 168  Close all open files for a pid.
 169 ****************************************************************************/
 170
 171 void file_close_pid(uint16 smbpid)
 172 {
 173         files_struct *fsp, *next;
 174
 175         for (fsp=Files;fsp;fsp=next) {
 176                 next = fsp->next;
 177                 if (fsp->file_pid == smbpid) {
 178                         close_file(fsp,False);
 179                 }
 180         }
 181 }
 182
 183 /****************************************************************************
 184  Initialise file structures.
 185 ****************************************************************************/
 186
 187 #define MAX_OPEN_FUDGEFACTOR 20
 188
 189 void file_init(void)
 190 {
 191         int request_max_open_files = lp_max_open_files();
 192         int real_lim;
 193
 194         /*
 195          * Set the max_open files to be the requested
 196          * max plus a fudgefactor to allow for the extra
 197          * fd's we need such as log files etc...
 198          */
 199         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 200
 201         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 202
 203         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 204                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 205
 206         if(real_max_open_files != request_max_open_files) {
 207                 DEBUG(1,("file_init: Information only: requested %d \
 208 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 209         }
 210
 211         SMB_ASSERT(real_max_open_files > 100);
 212
 213         file_bmap = bitmap_allocate(real_max_open_files);
 214
 215         if (!file_bmap) {
 216                 exit_server("out of memory in file_init");
 217         }
 218
 219         /*
 220          * Ensure that pipe_handle_oppset is set correctly.
 221          */
 222         set_pipe_handle_offset(real_max_open_files);
 223 }
 224
 225 /****************************************************************************
 226  Close files open by a specified vuid.
 227 ****************************************************************************/
 228
 229 void file_close_user(int vuid)
 230 {
 231         files_struct *fsp, *next;
 232
 233         for (fsp=Files;fsp;fsp=next) {
 234                 next=fsp->next;
 235                 if (fsp->vuid == vuid) {
 236                         close_file(fsp,False);
 237                 }
 238         }
 239 }
 240
 241 /****************************************************************************
 242  Debug to enumerate all open files in the smbd.
 243 ****************************************************************************/
 244
 245 void file_dump_open_table(void)
 246 {
 247         int count=0;
 248         files_struct *fsp;
 249
 250         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 251                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, fileid = %lu, dev = %x, inode = %.0f\n",
 252                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->file_id,
 253                         (unsigned int)fsp->dev, (double)fsp->inode ));
 254         }
 255 }
 256
 257 /****************************************************************************
 258  Find a fsp given a file descriptor.
 259 ****************************************************************************/
 260
 261 files_struct *file_find_fd(int fd)
 262 {
 263         int count=0;
 264         files_struct *fsp;
 265
 266         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 267                 if (fsp->fh->fd == fd) {
 268                         if (count > 10) {
 269                                 DLIST_PROMOTE(Files, fsp);
 270                         }
 271                         return fsp;
 272                 }
 273         }
 274
 275         return NULL;
 276 }
 277
 278 /****************************************************************************
 279  Find a fsp given a device, inode and file_id.
 280 ****************************************************************************/
 281
 282 files_struct *file_find_dif(SMB_DEV_T dev, SMB_INO_T inode, unsigned long file_id)
 283 {
 284         int count=0;
 285         files_struct *fsp;
 286
 287         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 288                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 289                 if (fsp->dev == dev &&
 290                     fsp->inode == inode &&
 291                     fsp->file_id == file_id ) {
 292                         if (count > 10) {
 293                                 DLIST_PROMOTE(Files, fsp);
 294                         }
 295                         /* Paranoia check. */
 296                         if (fsp->fh->fd == -1 && fsp->oplock_type != NO_OPLOCK) {
 297                                 DEBUG(0,("file_find_dif: file %s dev = %x, inode = %.0f, file_id = %u \
 298 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name, (unsigned int)fsp->dev,
 299                                                 (double)fsp->inode, (unsigned int)fsp->file_id,
 300                                                 (unsigned int)fsp->oplock_type ));
 301                                 smb_panic("file_find_dif\n");
 302                         }
 303                         return fsp;
 304                 }
 305         }
 306
 307         return NULL;
 308 }
 309
 310 /****************************************************************************
 311  Check if an fsp still exists.
 312 ****************************************************************************/
 313
 314 files_struct *file_find_fsp(files_struct *orig_fsp)
 315 {
 316         files_struct *fsp;
 317
 318         for (fsp=Files;fsp;fsp=fsp->next) {
 319                 if (fsp == orig_fsp)
 320                         return fsp;
 321         }
 322
 323         return NULL;
 324 }
 325
 326 /****************************************************************************
 327  Find the first fsp given a device and inode.
 328  We use a singleton cache here to speed up searching from getfilepathinfo
 329  calls.
 330 ****************************************************************************/
 331
 332 files_struct *file_find_di_first(SMB_DEV_T dev, SMB_INO_T inode)
 333 {
 334         files_struct *fsp;
 335
 336         if (fsp_fi_cache.dev == dev && fsp_fi_cache.inode == inode) {
 337                 /* Positive or negative cache hit. */
 338                 return fsp_fi_cache.fsp;
 339         }
 340
 341         fsp_fi_cache.dev = dev;
 342         fsp_fi_cache.inode = inode;
 343
 344         for (fsp=Files;fsp;fsp=fsp->next) {
 345                 if ( fsp->fh->fd != -1 &&
 346                                 fsp->dev == dev &&
 347                                 fsp->inode == inode ) {
 348                         /* Setup positive cache. */
 349                         fsp_fi_cache.fsp = fsp;
 350                         return fsp;
 351                 }
 352         }
 353
 354         /* Setup negative cache. */
 355         fsp_fi_cache.fsp = NULL;
 356         return NULL;
 357 }
 358
 359 /****************************************************************************
 360  Find the next fsp having the same device and inode.
 361 ****************************************************************************/
 362
 363 files_struct *file_find_di_next(files_struct *start_fsp)
 364 {
 365         files_struct *fsp;
 366
 367         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 368                 if ( fsp->fh->fd != -1 &&
 369                                 fsp->dev == start_fsp->dev &&
 370                                 fsp->inode == start_fsp->inode )
 371                         return fsp;
 372         }
 373
 374         return NULL;
 375 }
 376
 377 /****************************************************************************
 378  Find a fsp that is open for printing.
 379 ****************************************************************************/
 380
 381 files_struct *file_find_print(void)
 382 {
 383         files_struct *fsp;
 384
 385         for (fsp=Files;fsp;fsp=fsp->next) {
 386                 if (fsp->print_file) {
 387                         return fsp;
 388                 }
 389         }
 390
 391         return NULL;
 392 }
 393
 394 /****************************************************************************
 395  Set a pending modtime across all files with a given dev/ino pair.
 396  Record the owner of that modtime.
 397 ****************************************************************************/
 398
 399 void fsp_set_pending_modtime(files_struct *tfsp, time_t pmod)
 400 {
 401         files_struct *fsp;
 402
 403         if (null_mtime(pmod)) {
 404                 return;
 405         }
 406
 407         for (fsp = Files;fsp;fsp=fsp->next) {
 408                 if ( fsp->fh->fd != -1 &&
 409                                 fsp->dev == tfsp->dev &&
 410                                 fsp->inode == tfsp->inode ) {
 411                         fsp->pending_modtime = pmod;
 412                         fsp->pending_modtime_owner = False;
 413                 }
 414         }
 415
 416         tfsp->pending_modtime_owner = True;
 417 }
 418
 419 /****************************************************************************
 420  Sync open files on a connection.
 421 ****************************************************************************/
 422
 423 void file_sync_all(connection_struct *conn)
 424 {
 425         files_struct *fsp, *next;
 426
 427         for (fsp=Files;fsp;fsp=next) {
 428                 next=fsp->next;
 429                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 430                         sync_file(conn,fsp);
 431                 }
 432         }
 433 }
 434
 435 /****************************************************************************
 436  Free up a fsp.
 437 ****************************************************************************/
 438
 439 void file_free(files_struct *fsp)
 440 {
 441         DLIST_REMOVE(Files, fsp);
 442
 443         string_free(&fsp->fsp_name);
 444
 445         if (fsp->fake_file_handle) {
 446                 destroy_fake_file_handle(&fsp->fake_file_handle);
 447         }
 448
 449         if (fsp->fh->ref_count == 1) {
 450                 SAFE_FREE(fsp->fh);
 451         } else {
 452                 fsp->fh->ref_count--;
 453         }
 454
 455         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 456         files_used--;
 457
 458         DEBUG(5,("freed files structure %d (%d used)\n",
 459                  fsp->fnum, files_used));
 460
 461         /* this is paranoia, just in case someone tries to reuse the
 462            information */
 463         ZERO_STRUCTP(fsp);
 464
 465         if (fsp == chain_fsp) {
 466                 chain_fsp = NULL;
 467         }
 468
 469         /* Closing a file can invalidate the positive cache. */
 470         if (fsp == fsp_fi_cache.fsp) {
 471                 ZERO_STRUCT(fsp_fi_cache);
 472         }
 473
 474         SAFE_FREE(fsp);
 475 }
 476
 477 /****************************************************************************
 478  Get a fsp from a packet given the offset of a 16 bit fnum.
 479 ****************************************************************************/
 480
 481 files_struct *file_fsp(char *buf, int where)
 482 {
 483         int fnum, count=0;
 484         files_struct *fsp;
 485
 486         if (chain_fsp)
 487                 return chain_fsp;
 488
 489         if (!buf)
 490                 return NULL;
 491         fnum = SVAL(buf, where);
 492
 493         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 494                 if (fsp->fnum == fnum) {
 495                         chain_fsp = fsp;
 496                         if (count > 10) {
 497                                 DLIST_PROMOTE(Files, fsp);
 498                         }
 499                         return fsp;
 500                 }
 501         }
 502         return NULL;
 503 }
 504
 505 /****************************************************************************
 506  Reset the chained fsp - done at the start of a packet reply.
 507 ****************************************************************************/
 508
 509 void file_chain_reset(void)
 510 {
 511         chain_fsp = NULL;
 512 }
 513
 514 /****************************************************************************
 515  Save the chained fsp - done when about to do an oplock break.
 516 ****************************************************************************/
 517
 518 void file_chain_save(void)
 519 {
 520         oplock_save_chain_fsp = chain_fsp;
 521 }
 522
 523 /****************************************************************************
 524  Restore the chained fsp - done after an oplock break.
 525 ****************************************************************************/
 526
 527 void file_chain_restore(void)
 528 {
 529         chain_fsp = oplock_save_chain_fsp;
 530 }
 531
 532 /****************************************************************************
 533  Duplicate the file handle part for a DOS or FCB open.
 534 ****************************************************************************/
 535
 536 files_struct *dup_file_fsp(files_struct *fsp,
 537                                 uint32 access_mask,
 538                                 uint32 share_access,
 539                                 uint32 create_options)
 540 {
 541         files_struct *dup_fsp = file_new(fsp->conn);
 542
 543         if (!dup_fsp) {
 544                 return NULL;
 545         }
 546
 547         SAFE_FREE(dup_fsp->fh);
 548
 549         dup_fsp->fh = fsp->fh;
 550         dup_fsp->fh->ref_count++;
 551
 552         dup_fsp->dev = fsp->dev;
 553         dup_fsp->inode = fsp->inode;
 554         dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
 555         dup_fsp->mode = fsp->mode;
 556         dup_fsp->file_pid = fsp->file_pid;
 557         dup_fsp->vuid = fsp->vuid;
 558         dup_fsp->open_time = fsp->open_time;
 559         dup_fsp->access_mask = access_mask;
 560         dup_fsp->share_access = share_access;
 561         dup_fsp->pending_modtime_owner = fsp->pending_modtime_owner;
 562         dup_fsp->pending_modtime = fsp->pending_modtime;
 563         dup_fsp->last_write_time = fsp->last_write_time;
 564         dup_fsp->oplock_type = fsp->oplock_type;
 565         dup_fsp->can_lock = fsp->can_lock;
 566         dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 567         if (!CAN_WRITE(fsp->conn)) {
 568                 dup_fsp->can_write = False;
 569         } else {
 570                 dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 571         }
 572         dup_fsp->print_file = fsp->print_file;
 573         dup_fsp->modified = fsp->modified;
 574         dup_fsp->is_directory = fsp->is_directory;
 575         dup_fsp->is_stat = fsp->is_stat;
 576         dup_fsp->aio_write_behind = fsp->aio_write_behind;
 577         string_set(&dup_fsp->fsp_name,fsp->fsp_name);
 578
 579         return dup_fsp;
 580 }