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 a negative fsp_fi_cache. */
 126         if (fsp_fi_cache.fsp == NULL) {
 127                 ZERO_STRUCT(fsp_fi_cache);
 128         }
 129
 130         *result = fsp;
 131         return NT_STATUS_OK;
 132 }
 133
 134 /****************************************************************************
 135  Close all open files for a connection.
 136 ****************************************************************************/
 137
 138 void file_close_conn(connection_struct *conn)
 139 {
 140         files_struct *fsp, *next;
 141
 142         for (fsp=Files;fsp;fsp=next) {
 143                 next = fsp->next;
 144                 if (fsp->conn == conn) {
 145                         close_file(fsp,SHUTDOWN_CLOSE);
 146                 }
 147         }
 148 }
 149
 150 /****************************************************************************
 151  Close all open files for a pid and a vuid.
 152 ****************************************************************************/
 153
 154 void file_close_pid(uint16 smbpid, int vuid)
 155 {
 156         files_struct *fsp, *next;
 157
 158         for (fsp=Files;fsp;fsp=next) {
 159                 next = fsp->next;
 160                 if ((fsp->file_pid == smbpid) && (fsp->vuid == vuid)) {
 161                         close_file(fsp,SHUTDOWN_CLOSE);
 162                 }
 163         }
 164 }
 165
 166 /****************************************************************************
 167  Initialise file structures.
 168 ****************************************************************************/
 169
 170 #define MAX_OPEN_FUDGEFACTOR 20
 171
 172 void file_init(void)
 173 {
 174         int request_max_open_files = lp_max_open_files();
 175         int real_lim;
 176
 177         /*
 178          * Set the max_open files to be the requested
 179          * max plus a fudgefactor to allow for the extra
 180          * fd's we need such as log files etc...
 181          */
 182         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 183
 184         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 185
 186         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 187                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 188
 189         if(real_max_open_files != request_max_open_files) {
 190                 DEBUG(1,("file_init: Information only: requested %d \
 191 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 192         }
 193
 194         SMB_ASSERT(real_max_open_files > 100);
 195
 196         file_bmap = bitmap_allocate(real_max_open_files);
 197
 198         if (!file_bmap) {
 199                 exit_server("out of memory in file_init");
 200         }
 201
 202         /*
 203          * Ensure that pipe_handle_oppset is set correctly.
 204          */
 205         set_pipe_handle_offset(real_max_open_files);
 206 }
 207
 208 /****************************************************************************
 209  Close files open by a specified vuid.
 210 ****************************************************************************/
 211
 212 void file_close_user(int vuid)
 213 {
 214         files_struct *fsp, *next;
 215
 216         for (fsp=Files;fsp;fsp=next) {
 217                 next=fsp->next;
 218                 if (fsp->vuid == vuid) {
 219                         close_file(fsp,SHUTDOWN_CLOSE);
 220                 }
 221         }
 222 }
 223
 224 /****************************************************************************
 225  Debug to enumerate all open files in the smbd.
 226 ****************************************************************************/
 227
 228 void file_dump_open_table(void)
 229 {
 230         int count=0;
 231         files_struct *fsp;
 232
 233         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 234                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
 235                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 236                           file_id_static_string(&fsp->file_id)));
 237         }
 238 }
 239
 240 /****************************************************************************
 241  Find a fsp given a file descriptor.
 242 ****************************************************************************/
 243
 244 files_struct *file_find_fd(int fd)
 245 {
 246         int count=0;
 247         files_struct *fsp;
 248
 249         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 250                 if (fsp->fh->fd == fd) {
 251                         if (count > 10) {
 252                                 DLIST_PROMOTE(Files, fsp);
 253                         }
 254                         return fsp;
 255                 }
 256         }
 257
 258         return NULL;
 259 }
 260
 261 /****************************************************************************
 262  Find a fsp given a device, inode and file_id.
 263 ****************************************************************************/
 264
 265 files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
 266 {
 267         int count=0;
 268         files_struct *fsp;
 269
 270         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 271                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 272                 if (file_id_equal(&fsp->file_id, &id) &&
 273                     fsp->fh->gen_id == gen_id ) {
 274                         if (count > 10) {
 275                                 DLIST_PROMOTE(Files, fsp);
 276                         }
 277                         /* Paranoia check. */
 278                         if ((fsp->fh->fd == -1) &&
 279                             (fsp->oplock_type != NO_OPLOCK) &&
 280                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 281                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 282 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 283                                          file_id_static_string(&fsp->file_id),
 284                                          (unsigned int)fsp->fh->gen_id,
 285                                          (unsigned int)fsp->oplock_type ));
 286                                 smb_panic("file_find_dif");
 287                         }
 288                         return fsp;
 289                 }
 290         }
 291
 292         return NULL;
 293 }
 294
 295 /****************************************************************************
 296  Check if an fsp still exists.
 297 ****************************************************************************/
 298
 299 files_struct *file_find_fsp(files_struct *orig_fsp)
 300 {
 301         files_struct *fsp;
 302
 303         for (fsp=Files;fsp;fsp=fsp->next) {
 304                 if (fsp == orig_fsp)
 305                         return fsp;
 306         }
 307
 308         return NULL;
 309 }
 310
 311 /****************************************************************************
 312  Find the first fsp given a device and inode.
 313  We use a singleton cache here to speed up searching from getfilepathinfo
 314  calls.
 315 ****************************************************************************/
 316
 317 files_struct *file_find_di_first(struct file_id id)
 318 {
 319         files_struct *fsp;
 320
 321         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 322                 /* Positive or negative cache hit. */
 323                 return fsp_fi_cache.fsp;
 324         }
 325
 326         fsp_fi_cache.id = id;
 327
 328         for (fsp=Files;fsp;fsp=fsp->next) {
 329                 if ( fsp->fh->fd != -1 &&
 330                      file_id_equal(&fsp->file_id, &id)) {
 331                         /* Setup positive cache. */
 332                         fsp_fi_cache.fsp = fsp;
 333                         return fsp;
 334                 }
 335         }
 336
 337         /* Setup negative cache. */
 338         fsp_fi_cache.fsp = NULL;
 339         return NULL;
 340 }
 341
 342 /****************************************************************************
 343  Find the next fsp having the same device and inode.
 344 ****************************************************************************/
 345
 346 files_struct *file_find_di_next(files_struct *start_fsp)
 347 {
 348         files_struct *fsp;
 349
 350         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 351                 if ( fsp->fh->fd != -1 &&
 352                      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  Set a pending modtime across all files with a given dev/ino pair.
 379  Record the owner of that modtime.
 380 ****************************************************************************/
 381
 382 void fsp_set_pending_modtime(files_struct *tfsp, const struct timespec mod)
 383 {
 384         files_struct *fsp;
 385
 386         if (null_timespec(mod)) {
 387                 return;
 388         }
 389
 390         for (fsp = Files;fsp;fsp=fsp->next) {
 391                 if ( fsp->fh->fd != -1 && file_id_equal(&fsp->file_id, &tfsp->file_id)) {
 392                         fsp->pending_modtime = mod;
 393                         fsp->pending_modtime_owner = False;
 394                 }
 395         }
 396
 397         tfsp->pending_modtime_owner = True;
 398 }
 399
 400 /****************************************************************************
 401  Sync open files on a connection.
 402 ****************************************************************************/
 403
 404 void file_sync_all(connection_struct *conn)
 405 {
 406         files_struct *fsp, *next;
 407
 408         for (fsp=Files;fsp;fsp=next) {
 409                 next=fsp->next;
 410                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 411                         sync_file(conn, fsp, True /* write through */);
 412                 }
 413         }
 414 }
 415
 416 /****************************************************************************
 417  Free up a fsp.
 418 ****************************************************************************/
 419
 420 void file_free(files_struct *fsp)
 421 {
 422         DLIST_REMOVE(Files, fsp);
 423
 424         string_free(&fsp->fsp_name);
 425
 426         if (fsp->fake_file_handle) {
 427                 destroy_fake_file_handle(&fsp->fake_file_handle);
 428         }
 429
 430         if (fsp->fh->ref_count == 1) {
 431                 SAFE_FREE(fsp->fh);
 432         } else {
 433                 fsp->fh->ref_count--;
 434         }
 435
 436         if (fsp->notify) {
 437                 notify_remove(fsp->conn->notify_ctx, fsp);
 438                 TALLOC_FREE(fsp->notify);
 439         }
 440
 441         /* Ensure this event will never fire. */
 442         TALLOC_FREE(fsp->oplock_timeout);
 443
 444         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 445         files_used--;
 446
 447         DEBUG(5,("freed files structure %d (%d used)\n",
 448                  fsp->fnum, files_used));
 449
 450         /* this is paranoia, just in case someone tries to reuse the
 451            information */
 452         ZERO_STRUCTP(fsp);
 453
 454         if (fsp == chain_fsp) {
 455                 chain_fsp = NULL;
 456         }
 457
 458         /* Closing a file can invalidate the positive cache. */
 459         if (fsp == fsp_fi_cache.fsp) {
 460                 ZERO_STRUCT(fsp_fi_cache);
 461         }
 462
 463         SAFE_FREE(fsp);
 464 }
 465
 466 /****************************************************************************
 467  Get an fsp from a 16 bit fnum.
 468 ****************************************************************************/
 469
 470 files_struct *file_fnum(uint16 fnum)
 471 {
 472         files_struct *fsp;
 473         int count=0;
 474
 475         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 476                 if (fsp->fnum == fnum) {
 477                         if (count > 10) {
 478                                 DLIST_PROMOTE(Files, fsp);
 479                         }
 480                         return fsp;
 481                 }
 482         }
 483         return NULL;
 484 }
 485
 486 /****************************************************************************
 487  Get an fsp from a packet given the offset of a 16 bit fnum.
 488 ****************************************************************************/
 489
 490 files_struct *file_fsp(char *buf, int where)
 491 {
 492         files_struct *fsp;
 493
 494         if (chain_fsp) {
 495                 return chain_fsp;
 496         }
 497
 498         if (!buf) {
 499                 return NULL;
 500         }
 501
 502         fsp = file_fnum(SVAL(buf, where));
 503         if (fsp) {
 504                 chain_fsp = fsp;
 505         }
 506         return fsp;
 507 }
 508
 509 /****************************************************************************
 510  Reset the chained fsp - done at the start of a packet reply.
 511 ****************************************************************************/
 512
 513 void file_chain_reset(void)
 514 {
 515         chain_fsp = NULL;
 516 }
 517
 518 /****************************************************************************
 519  Duplicate the file handle part for a DOS or FCB open.
 520 ****************************************************************************/
 521
 522 NTSTATUS dup_file_fsp(files_struct *fsp,
 523                                 uint32 access_mask,
 524                                 uint32 share_access,
 525                                 uint32 create_options,
 526                                 files_struct **result)
 527 {
 528         NTSTATUS status;
 529         files_struct *dup_fsp;
 530
 531         status = file_new(fsp->conn, &dup_fsp);
 532
 533         if (!NT_STATUS_IS_OK(status)) {
 534                 return status;
 535         }
 536
 537         SAFE_FREE(dup_fsp->fh);
 538
 539         dup_fsp->fh = fsp->fh;
 540         dup_fsp->fh->ref_count++;
 541
 542         dup_fsp->file_id = fsp->file_id;
 543         dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
 544         dup_fsp->mode = fsp->mode;
 545         dup_fsp->file_pid = fsp->file_pid;
 546         dup_fsp->vuid = fsp->vuid;
 547         dup_fsp->open_time = fsp->open_time;
 548         dup_fsp->access_mask = access_mask;
 549         dup_fsp->share_access = share_access;
 550         dup_fsp->pending_modtime_owner = fsp->pending_modtime_owner;
 551         dup_fsp->pending_modtime = fsp->pending_modtime;
 552         dup_fsp->last_write_time = fsp->last_write_time;
 553         dup_fsp->oplock_type = fsp->oplock_type;
 554         dup_fsp->can_lock = fsp->can_lock;
 555         dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 556         if (!CAN_WRITE(fsp->conn)) {
 557                 dup_fsp->can_write = False;
 558         } else {
 559                 dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 560         }
 561         dup_fsp->print_file = fsp->print_file;
 562         dup_fsp->modified = fsp->modified;
 563         dup_fsp->is_directory = fsp->is_directory;
 564         dup_fsp->is_stat = fsp->is_stat;
 565         string_set(&dup_fsp->fsp_name,fsp->fsp_name);
 566
 567         *result = dup_fsp;
 568         return NT_STATUS_OK;
 569 }