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 3 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, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 static int real_max_open_files;
  23
  24 #define VALID_FNUM(fnum)   (((fnum) >= 0) && ((fnum) < real_max_open_files))
  25
  26 #define FILE_HANDLE_OFFSET 0x1000
  27
  28 static struct bitmap *file_bmap;
  29
  30 static files_struct *Files;
  31
  32 /* a fsp to use when chaining */
  33 static files_struct *chain_fsp = NULL;
  34
  35 static int files_used;
  36
  37 /* A singleton cache to speed up searching by dev/inode. */
  38 static struct fsp_singleton_cache {
  39         files_struct *fsp;
  40         struct file_id id;
  41 } fsp_fi_cache;
  42
  43 /****************************************************************************
  44  Return a unique number identifying this fsp over the life of this pid.
  45 ****************************************************************************/
  46
  47 static unsigned long get_gen_count(void)
  48 {
  49         static unsigned long file_gen_counter;
  50
  51         if ((++file_gen_counter) == 0)
  52                 return ++file_gen_counter;
  53         return file_gen_counter;
  54 }
  55
  56 /****************************************************************************
  57  Find first available file slot.
  58 ****************************************************************************/
  59
  60 NTSTATUS file_new(connection_struct *conn, files_struct **result)
  61 {
  62         int i;
  63         static int first_file;
  64         files_struct *fsp;
  65
  66         /* we want to give out file handles differently on each new
  67            connection because of a common bug in MS clients where they try to
  68            reuse a file descriptor from an earlier smb connection. This code
  69            increases the chance that the errant client will get an error rather
  70            than causing corruption */
  71         if (first_file == 0) {
  72                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  73         }
  74
  75         /* TODO: Port the id-tree implementation from Samba4 */
  76
  77         i = bitmap_find(file_bmap, first_file);
  78         if (i == -1) {
  79                 DEBUG(0,("ERROR! Out of file structures\n"));
  80                 /* TODO: We have to unconditionally return a DOS error here,
  81                  * W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
  82                  * NTSTATUS negotiated */
  83                 return NT_STATUS_TOO_MANY_OPENED_FILES;
  84         }
  85
  86         fsp = SMB_MALLOC_P(files_struct);
  87         if (!fsp) {
  88                 return NT_STATUS_NO_MEMORY;
  89         }
  90
  91         ZERO_STRUCTP(fsp);
  92
  93         fsp->fh = SMB_MALLOC_P(struct fd_handle);
  94         if (!fsp->fh) {
  95                 SAFE_FREE(fsp);
  96                 return NT_STATUS_NO_MEMORY;
  97         }
  98
  99         ZERO_STRUCTP(fsp->fh);
 100
 101         fsp->fh->ref_count = 1;
 102         fsp->fh->fd = -1;
 103
 104         fsp->conn = conn;
 105         fsp->fh->gen_id = get_gen_count();
 106         GetTimeOfDay(&fsp->open_time);
 107
 108         first_file = (i+1) % real_max_open_files;
 109
 110         bitmap_set(file_bmap, i);
 111         files_used++;
 112
 113         fsp->fnum = i + FILE_HANDLE_OFFSET;
 114         SMB_ASSERT(fsp->fnum < 65536);
 115
 116         string_set(&fsp->fsp_name,"");
 117
 118         DLIST_ADD(Files, fsp);
 119
 120         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 121                  i, fsp->fnum, files_used));
 122
 123         chain_fsp = fsp;
 124
 125         /* A new fsp invalidates the positive and
 126           negative fsp_fi_cache as the new fsp is pushed
 127           at the start of the list and we search from
 128           a cache hit to the *end* of the list. */
 129
 130         ZERO_STRUCT(fsp_fi_cache);
 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, gen = %lu, fileid=%s\n",
 237                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 238                           file_id_string_tos(&fsp->file_id)));
 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(struct file_id id, unsigned long gen_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 (file_id_equal(&fsp->file_id, &id) &&
 275                     fsp->fh->gen_id == gen_id ) {
 276                         if (count > 10) {
 277                                 DLIST_PROMOTE(Files, fsp);
 278                         }
 279                         /* Paranoia check. */
 280                         if ((fsp->fh->fd == -1) &&
 281                             (fsp->oplock_type != NO_OPLOCK) &&
 282                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 283                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 284 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 285                                          file_id_string_tos(&fsp->file_id),
 286                                          (unsigned int)fsp->fh->gen_id,
 287                                          (unsigned int)fsp->oplock_type ));
 288                                 smb_panic("file_find_dif");
 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(struct file_id id)
 320 {
 321         files_struct *fsp;
 322
 323         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 324                 /* Positive or negative cache hit. */
 325                 return fsp_fi_cache.fsp;
 326         }
 327
 328         fsp_fi_cache.id = id;
 329
 330         for (fsp=Files;fsp;fsp=fsp->next) {
 331                 if (file_id_equal(&fsp->file_id, &id)) {
 332                         /* Setup positive cache. */
 333                         fsp_fi_cache.fsp = fsp;
 334                         return fsp;
 335                 }
 336         }
 337
 338         /* Setup negative cache. */
 339         fsp_fi_cache.fsp = NULL;
 340         return NULL;
 341 }
 342
 343 /****************************************************************************
 344  Find the next fsp having the same device and inode.
 345 ****************************************************************************/
 346
 347 files_struct *file_find_di_next(files_struct *start_fsp)
 348 {
 349         files_struct *fsp;
 350
 351         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 352                 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
 353                         return fsp;
 354                 }
 355         }
 356
 357         return NULL;
 358 }
 359
 360 /****************************************************************************
 361  Find a fsp that is open for printing.
 362 ****************************************************************************/
 363
 364 files_struct *file_find_print(void)
 365 {
 366         files_struct *fsp;
 367
 368         for (fsp=Files;fsp;fsp=fsp->next) {
 369                 if (fsp->print_file) {
 370                         return fsp;
 371                 }
 372         }
 373
 374         return NULL;
 375 }
 376
 377 /****************************************************************************
 378  Sync open files on a connection.
 379 ****************************************************************************/
 380
 381 void file_sync_all(connection_struct *conn)
 382 {
 383         files_struct *fsp, *next;
 384
 385         for (fsp=Files;fsp;fsp=next) {
 386                 next=fsp->next;
 387                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 388                         sync_file(conn, fsp, True /* write through */);
 389                 }
 390         }
 391 }
 392
 393 /****************************************************************************
 394  Free up a fsp.
 395 ****************************************************************************/
 396
 397 void file_free(files_struct *fsp)
 398 {
 399         DLIST_REMOVE(Files, fsp);
 400
 401         string_free(&fsp->fsp_name);
 402
 403         TALLOC_FREE(fsp->fake_file_handle);
 404
 405         if (fsp->fh->ref_count == 1) {
 406                 SAFE_FREE(fsp->fh);
 407         } else {
 408                 fsp->fh->ref_count--;
 409         }
 410
 411         if (fsp->notify) {
 412                 notify_remove(fsp->conn->notify_ctx, fsp);
 413                 TALLOC_FREE(fsp->notify);
 414         }
 415
 416         /* Ensure this event will never fire. */
 417         TALLOC_FREE(fsp->oplock_timeout);
 418
 419         /* Ensure this event will never fire. */
 420         TALLOC_FREE(fsp->update_write_time_event);
 421
 422         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 423         files_used--;
 424
 425         DEBUG(5,("freed files structure %d (%d used)\n",
 426                  fsp->fnum, files_used));
 427
 428         /* this is paranoia, just in case someone tries to reuse the
 429            information */
 430         ZERO_STRUCTP(fsp);
 431
 432         if (fsp == chain_fsp) {
 433                 chain_fsp = NULL;
 434         }
 435
 436         /* Closing a file can invalidate the positive cache. */
 437         if (fsp == fsp_fi_cache.fsp) {
 438                 ZERO_STRUCT(fsp_fi_cache);
 439         }
 440
 441         /* Drop all remaining extensions. */
 442         while (fsp->vfs_extension) {
 443                 vfs_remove_fsp_extension(fsp->vfs_extension->owner, fsp);
 444         }
 445
 446         SAFE_FREE(fsp);
 447 }
 448
 449 /****************************************************************************
 450  Get an fsp from a 16 bit fnum.
 451 ****************************************************************************/
 452
 453 files_struct *file_fnum(uint16 fnum)
 454 {
 455         files_struct *fsp;
 456         int count=0;
 457
 458         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 459                 if (fsp->fnum == fnum) {
 460                         if (count > 10) {
 461                                 DLIST_PROMOTE(Files, fsp);
 462                         }
 463                         return fsp;
 464                 }
 465         }
 466         return NULL;
 467 }
 468
 469 /****************************************************************************
 470  Get an fsp from a packet given the offset of a 16 bit fnum.
 471 ****************************************************************************/
 472
 473 files_struct *file_fsp(uint16 fid)
 474 {
 475         files_struct *fsp;
 476
 477         if (chain_fsp) {
 478                 return chain_fsp;
 479         }
 480
 481         fsp = file_fnum(fid);
 482         if (fsp) {
 483                 chain_fsp = fsp;
 484         }
 485         return fsp;
 486 }
 487
 488 /****************************************************************************
 489  Reset the chained fsp - done at the start of a packet reply.
 490 ****************************************************************************/
 491
 492 void file_chain_reset(void)
 493 {
 494         chain_fsp = NULL;
 495 }
 496
 497 /****************************************************************************
 498  Duplicate the file handle part for a DOS or FCB open.
 499 ****************************************************************************/
 500
 501 NTSTATUS dup_file_fsp(files_struct *fsp,
 502                                 uint32 access_mask,
 503                                 uint32 share_access,
 504                                 uint32 create_options,
 505                                 files_struct **result)
 506 {
 507         NTSTATUS status;
 508         files_struct *dup_fsp;
 509
 510         status = file_new(fsp->conn, &dup_fsp);
 511
 512         if (!NT_STATUS_IS_OK(status)) {
 513                 return status;
 514         }
 515
 516         SAFE_FREE(dup_fsp->fh);
 517
 518         dup_fsp->fh = fsp->fh;
 519         dup_fsp->fh->ref_count++;
 520
 521         dup_fsp->file_id = fsp->file_id;
 522         dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
 523         dup_fsp->mode = fsp->mode;
 524         dup_fsp->file_pid = fsp->file_pid;
 525         dup_fsp->vuid = fsp->vuid;
 526         dup_fsp->open_time = fsp->open_time;
 527         dup_fsp->access_mask = access_mask;
 528         dup_fsp->share_access = share_access;
 529         dup_fsp->oplock_type = fsp->oplock_type;
 530         dup_fsp->can_lock = fsp->can_lock;
 531         dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 532         if (!CAN_WRITE(fsp->conn)) {
 533                 dup_fsp->can_write = False;
 534         } else {
 535                 dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 536         }
 537         dup_fsp->print_file = fsp->print_file;
 538         dup_fsp->modified = fsp->modified;
 539         dup_fsp->is_directory = fsp->is_directory;
 540         dup_fsp->aio_write_behind = fsp->aio_write_behind;
 541         string_set(&dup_fsp->fsp_name,fsp->fsp_name);
 542
 543         *result = dup_fsp;
 544         return NT_STATUS_OK;
 545 }