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 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         conn->num_files_open++;
 133
 134         *result = fsp;
 135         return NT_STATUS_OK;
 136 }
 137
 138 /****************************************************************************
 139  Close all open files for a connection.
 140 ****************************************************************************/
 141
 142 void file_close_conn(connection_struct *conn)
 143 {
 144         files_struct *fsp, *next;
 145
 146         for (fsp=Files;fsp;fsp=next) {
 147                 next = fsp->next;
 148                 if (fsp->conn == conn) {
 149                         close_file(fsp,SHUTDOWN_CLOSE);
 150                 }
 151         }
 152 }
 153
 154 /****************************************************************************
 155  Close all open files for a pid and a vuid.
 156 ****************************************************************************/
 157
 158 void file_close_pid(uint16 smbpid, int vuid)
 159 {
 160         files_struct *fsp, *next;
 161
 162         for (fsp=Files;fsp;fsp=next) {
 163                 next = fsp->next;
 164                 if ((fsp->file_pid == smbpid) && (fsp->vuid == vuid)) {
 165                         close_file(fsp,SHUTDOWN_CLOSE);
 166                 }
 167         }
 168 }
 169
 170 /****************************************************************************
 171  Initialise file structures.
 172 ****************************************************************************/
 173
 174 #define MAX_OPEN_FUDGEFACTOR 20
 175
 176 void file_init(void)
 177 {
 178         int request_max_open_files = lp_max_open_files();
 179         int real_lim;
 180
 181         /*
 182          * Set the max_open files to be the requested
 183          * max plus a fudgefactor to allow for the extra
 184          * fd's we need such as log files etc...
 185          */
 186         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 187
 188         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 189
 190         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 191                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 192
 193         if(real_max_open_files != request_max_open_files) {
 194                 DEBUG(1,("file_init: Information only: requested %d \
 195 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 196         }
 197
 198         SMB_ASSERT(real_max_open_files > 100);
 199
 200         file_bmap = bitmap_allocate(real_max_open_files);
 201
 202         if (!file_bmap) {
 203                 exit_server("out of memory in file_init");
 204         }
 205
 206         /*
 207          * Ensure that pipe_handle_oppset is set correctly.
 208          */
 209         set_pipe_handle_offset(real_max_open_files);
 210 }
 211
 212 /****************************************************************************
 213  Close files open by a specified vuid.
 214 ****************************************************************************/
 215
 216 void file_close_user(int vuid)
 217 {
 218         files_struct *fsp, *next;
 219
 220         for (fsp=Files;fsp;fsp=next) {
 221                 next=fsp->next;
 222                 if (fsp->vuid == vuid) {
 223                         close_file(fsp,SHUTDOWN_CLOSE);
 224                 }
 225         }
 226 }
 227
 228 /****************************************************************************
 229  Debug to enumerate all open files in the smbd.
 230 ****************************************************************************/
 231
 232 void file_dump_open_table(void)
 233 {
 234         int count=0;
 235         files_struct *fsp;
 236
 237         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 238                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
 239                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 240                           file_id_string_tos(&fsp->file_id)));
 241         }
 242 }
 243
 244 /****************************************************************************
 245  Find a fsp given a file descriptor.
 246 ****************************************************************************/
 247
 248 files_struct *file_find_fd(int fd)
 249 {
 250         int count=0;
 251         files_struct *fsp;
 252
 253         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 254                 if (fsp->fh->fd == fd) {
 255                         if (count > 10) {
 256                                 DLIST_PROMOTE(Files, fsp);
 257                         }
 258                         return fsp;
 259                 }
 260         }
 261
 262         return NULL;
 263 }
 264
 265 /****************************************************************************
 266  Find a fsp given a device, inode and file_id.
 267 ****************************************************************************/
 268
 269 files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
 270 {
 271         int count=0;
 272         files_struct *fsp;
 273
 274         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 275                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 276                 if (file_id_equal(&fsp->file_id, &id) &&
 277                     fsp->fh->gen_id == gen_id ) {
 278                         if (count > 10) {
 279                                 DLIST_PROMOTE(Files, fsp);
 280                         }
 281                         /* Paranoia check. */
 282                         if ((fsp->fh->fd == -1) &&
 283                             (fsp->oplock_type != NO_OPLOCK) &&
 284                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 285                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 286 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 287                                          file_id_string_tos(&fsp->file_id),
 288                                          (unsigned int)fsp->fh->gen_id,
 289                                          (unsigned int)fsp->oplock_type ));
 290                                 smb_panic("file_find_dif");
 291                         }
 292                         return fsp;
 293                 }
 294         }
 295
 296         return NULL;
 297 }
 298
 299 /****************************************************************************
 300  Check if an fsp still exists.
 301 ****************************************************************************/
 302
 303 files_struct *file_find_fsp(files_struct *orig_fsp)
 304 {
 305         files_struct *fsp;
 306
 307         for (fsp=Files;fsp;fsp=fsp->next) {
 308                 if (fsp == orig_fsp)
 309                         return fsp;
 310         }
 311
 312         return NULL;
 313 }
 314
 315 /****************************************************************************
 316  Find the first fsp given a device and inode.
 317  We use a singleton cache here to speed up searching from getfilepathinfo
 318  calls.
 319 ****************************************************************************/
 320
 321 files_struct *file_find_di_first(struct file_id id)
 322 {
 323         files_struct *fsp;
 324
 325         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 326                 /* Positive or negative cache hit. */
 327                 return fsp_fi_cache.fsp;
 328         }
 329
 330         fsp_fi_cache.id = id;
 331
 332         for (fsp=Files;fsp;fsp=fsp->next) {
 333                 if (file_id_equal(&fsp->file_id, &id)) {
 334                         /* Setup positive cache. */
 335                         fsp_fi_cache.fsp = fsp;
 336                         return fsp;
 337                 }
 338         }
 339
 340         /* Setup negative cache. */
 341         fsp_fi_cache.fsp = NULL;
 342         return NULL;
 343 }
 344
 345 /****************************************************************************
 346  Find the next fsp having the same device and inode.
 347 ****************************************************************************/
 348
 349 files_struct *file_find_di_next(files_struct *start_fsp)
 350 {
 351         files_struct *fsp;
 352
 353         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 354                 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
 355                         return fsp;
 356                 }
 357         }
 358
 359         return NULL;
 360 }
 361
 362 /****************************************************************************
 363  Find a fsp that is open for printing.
 364 ****************************************************************************/
 365
 366 files_struct *file_find_print(void)
 367 {
 368         files_struct *fsp;
 369
 370         for (fsp=Files;fsp;fsp=fsp->next) {
 371                 if (fsp->print_file) {
 372                         return fsp;
 373                 }
 374         }
 375
 376         return NULL;
 377 }
 378
 379 /****************************************************************************
 380  Sync open files on a connection.
 381 ****************************************************************************/
 382
 383 void file_sync_all(connection_struct *conn)
 384 {
 385         files_struct *fsp, *next;
 386
 387         for (fsp=Files;fsp;fsp=next) {
 388                 next=fsp->next;
 389                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 390                         sync_file(conn, fsp, True /* write through */);
 391                 }
 392         }
 393 }
 394
 395 /****************************************************************************
 396  Free up a fsp.
 397 ****************************************************************************/
 398
 399 void file_free(files_struct *fsp)
 400 {
 401         DLIST_REMOVE(Files, fsp);
 402
 403         string_free(&fsp->fsp_name);
 404
 405         if (fsp->fake_file_handle) {
 406                 destroy_fake_file_handle(&fsp->fake_file_handle);
 407         }
 408
 409         if (fsp->fh->ref_count == 1) {
 410                 SAFE_FREE(fsp->fh);
 411         } else {
 412                 fsp->fh->ref_count--;
 413         }
 414
 415         if (fsp->notify) {
 416                 notify_remove(fsp->conn->notify_ctx, fsp);
 417                 TALLOC_FREE(fsp->notify);
 418         }
 419
 420         /* Ensure this event will never fire. */
 421         TALLOC_FREE(fsp->oplock_timeout);
 422
 423         /* Ensure this event will never fire. */
 424         TALLOC_FREE(fsp->update_write_time_event);
 425
 426         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 427         files_used--;
 428
 429         DEBUG(5,("freed files structure %d (%d used)\n",
 430                  fsp->fnum, files_used));
 431
 432         fsp->conn->num_files_open--;
 433
 434         if (fsp == chain_fsp) {
 435                 chain_fsp = NULL;
 436         }
 437
 438         /* Closing a file can invalidate the positive cache. */
 439         if (fsp == fsp_fi_cache.fsp) {
 440                 ZERO_STRUCT(fsp_fi_cache);
 441         }
 442
 443         /* Drop all remaining extensions. */
 444         while (fsp->vfs_extension) {
 445                 vfs_remove_fsp_extension(fsp->vfs_extension->owner, fsp);
 446         }
 447
 448         /* this is paranoia, just in case someone tries to reuse the
 449            information */
 450         ZERO_STRUCTP(fsp);
 451
 452         SAFE_FREE(fsp);
 453 }
 454
 455 /****************************************************************************
 456  Get an fsp from a 16 bit fnum.
 457 ****************************************************************************/
 458
 459 files_struct *file_fnum(uint16 fnum)
 460 {
 461         files_struct *fsp;
 462         int count=0;
 463
 464         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 465                 if (fsp->fnum == fnum) {
 466                         if (count > 10) {
 467                                 DLIST_PROMOTE(Files, fsp);
 468                         }
 469                         return fsp;
 470                 }
 471         }
 472         return NULL;
 473 }
 474
 475 /****************************************************************************
 476  Get an fsp from a packet given the offset of a 16 bit fnum.
 477 ****************************************************************************/
 478
 479 files_struct *file_fsp(uint16 fid)
 480 {
 481         files_struct *fsp;
 482
 483         if (chain_fsp) {
 484                 return chain_fsp;
 485         }
 486
 487         fsp = file_fnum(fid);
 488         if (fsp) {
 489                 chain_fsp = fsp;
 490         }
 491         return fsp;
 492 }
 493
 494 /****************************************************************************
 495  Reset the chained fsp - done at the start of a packet reply.
 496 ****************************************************************************/
 497
 498 void file_chain_reset(void)
 499 {
 500         chain_fsp = NULL;
 501 }
 502
 503 /****************************************************************************
 504  Duplicate the file handle part for a DOS or FCB open.
 505 ****************************************************************************/
 506
 507 void dup_file_fsp(files_struct *from,
 508                         uint32 access_mask,
 509                         uint32 share_access,
 510                         uint32 create_options,
 511                         files_struct *to)
 512 {
 513         SAFE_FREE(to->fh);
 514
 515         to->fh = from->fh;
 516         to->fh->ref_count++;
 517
 518         to->file_id = from->file_id;
 519         to->initial_allocation_size = from->initial_allocation_size;
 520         to->mode = from->mode;
 521         to->file_pid = from->file_pid;
 522         to->vuid = from->vuid;
 523         to->open_time = from->open_time;
 524         to->access_mask = access_mask;
 525         to->share_access = share_access;
 526         to->oplock_type = from->oplock_type;
 527         to->can_lock = from->can_lock;
 528         to->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 529         if (!CAN_WRITE(from->conn)) {
 530                 to->can_write = False;
 531         } else {
 532                 to->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 533         }
 534         to->print_file = from->print_file;
 535         to->modified = from->modified;
 536         to->is_directory = from->is_directory;
 537         to->is_stat = from->is_stat;
 538         to->aio_write_behind = from->aio_write_behind;
 539         string_set(&to->fsp_name,from->fsp_name);
 540 }