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 #include "smbd/globals.h"
  22
  23 #define VALID_FNUM(fnum)   (((fnum) >= 0) && ((fnum) < real_max_open_files))
  24
  25 #define FILE_HANDLE_OFFSET 0x1000
  26
  27 /****************************************************************************
  28  Return a unique number identifying this fsp over the life of this pid.
  29 ****************************************************************************/
  30
  31 static unsigned long get_gen_count(void)
  32 {
  33         if ((++file_gen_counter) == 0)
  34                 return ++file_gen_counter;
  35         return file_gen_counter;
  36 }
  37
  38 /****************************************************************************
  39  Find first available file slot.
  40 ****************************************************************************/
  41
  42 NTSTATUS file_new(struct smb_request *req, connection_struct *conn,
  43                   files_struct **result)
  44 {
  45         int i;
  46         files_struct *fsp;
  47
  48         /* we want to give out file handles differently on each new
  49            connection because of a common bug in MS clients where they try to
  50            reuse a file descriptor from an earlier smb connection. This code
  51            increases the chance that the errant client will get an error rather
  52            than causing corruption */
  53         if (first_file == 0) {
  54                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  55         }
  56
  57         /* TODO: Port the id-tree implementation from Samba4 */
  58
  59         i = bitmap_find(file_bmap, first_file);
  60         if (i == -1) {
  61                 DEBUG(0,("ERROR! Out of file structures\n"));
  62                 /* TODO: We have to unconditionally return a DOS error here,
  63                  * W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
  64                  * NTSTATUS negotiated */
  65                 return NT_STATUS_TOO_MANY_OPENED_FILES;
  66         }
  67
  68         fsp = SMB_MALLOC_P(files_struct);
  69         if (!fsp) {
  70                 return NT_STATUS_NO_MEMORY;
  71         }
  72
  73         ZERO_STRUCTP(fsp);
  74
  75         fsp->fh = SMB_MALLOC_P(struct fd_handle);
  76         if (!fsp->fh) {
  77                 SAFE_FREE(fsp);
  78                 return NT_STATUS_NO_MEMORY;
  79         }
  80
  81         ZERO_STRUCTP(fsp->fh);
  82
  83         fsp->fh->ref_count = 1;
  84         fsp->fh->fd = -1;
  85
  86         fsp->conn = conn;
  87         fsp->fh->gen_id = get_gen_count();
  88         GetTimeOfDay(&fsp->open_time);
  89
  90         first_file = (i+1) % real_max_open_files;
  91
  92         bitmap_set(file_bmap, i);
  93         files_used++;
  94
  95         fsp->fnum = i + FILE_HANDLE_OFFSET;
  96         SMB_ASSERT(fsp->fnum < 65536);
  97
  98         string_set(&fsp->fsp_name,"");
  99
 100         DLIST_ADD(Files, fsp);
 101
 102         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 103                  i, fsp->fnum, files_used));
 104
 105         if (req != NULL) {
 106                 req->chain_fsp = fsp;
 107         }
 108
 109         /* A new fsp invalidates the positive and
 110           negative fsp_fi_cache as the new fsp is pushed
 111           at the start of the list and we search from
 112           a cache hit to the *end* of the list. */
 113
 114         ZERO_STRUCT(fsp_fi_cache);
 115
 116         conn->num_files_open++;
 117
 118         *result = fsp;
 119         return NT_STATUS_OK;
 120 }
 121
 122 /****************************************************************************
 123  Close all open files for a connection.
 124 ****************************************************************************/
 125
 126 void file_close_conn(connection_struct *conn)
 127 {
 128         files_struct *fsp, *next;
 129
 130         for (fsp=Files;fsp;fsp=next) {
 131                 next = fsp->next;
 132                 if (fsp->conn == conn) {
 133                         close_file(NULL, fsp, SHUTDOWN_CLOSE);
 134                 }
 135         }
 136 }
 137
 138 /****************************************************************************
 139  Close all open files for a pid and a vuid.
 140 ****************************************************************************/
 141
 142 void file_close_pid(uint16 smbpid, int vuid)
 143 {
 144         files_struct *fsp, *next;
 145
 146         for (fsp=Files;fsp;fsp=next) {
 147                 next = fsp->next;
 148                 if ((fsp->file_pid == smbpid) && (fsp->vuid == vuid)) {
 149                         close_file(NULL, fsp, SHUTDOWN_CLOSE);
 150                 }
 151         }
 152 }
 153
 154 /****************************************************************************
 155  Initialise file structures.
 156 ****************************************************************************/
 157
 158 #define MAX_OPEN_FUDGEFACTOR 20
 159
 160 void file_init(void)
 161 {
 162         int request_max_open_files = lp_max_open_files();
 163         int real_lim;
 164
 165         /*
 166          * Set the max_open files to be the requested
 167          * max plus a fudgefactor to allow for the extra
 168          * fd's we need such as log files etc...
 169          */
 170         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 171
 172         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 173
 174         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 175                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 176
 177         if(real_max_open_files != request_max_open_files) {
 178                 DEBUG(1,("file_init: Information only: requested %d \
 179 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 180         }
 181
 182         SMB_ASSERT(real_max_open_files > 100);
 183
 184         file_bmap = bitmap_allocate(real_max_open_files);
 185
 186         if (!file_bmap) {
 187                 exit_server("out of memory in file_init");
 188         }
 189 }
 190
 191 /****************************************************************************
 192  Close files open by a specified vuid.
 193 ****************************************************************************/
 194
 195 void file_close_user(int vuid)
 196 {
 197         files_struct *fsp, *next;
 198
 199         for (fsp=Files;fsp;fsp=next) {
 200                 next=fsp->next;
 201                 if (fsp->vuid == vuid) {
 202                         close_file(NULL, fsp, SHUTDOWN_CLOSE);
 203                 }
 204         }
 205 }
 206
 207 /****************************************************************************
 208  Debug to enumerate all open files in the smbd.
 209 ****************************************************************************/
 210
 211 void file_dump_open_table(void)
 212 {
 213         int count=0;
 214         files_struct *fsp;
 215
 216         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 217                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
 218                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 219                           file_id_string_tos(&fsp->file_id)));
 220         }
 221 }
 222
 223 /****************************************************************************
 224  Find a fsp given a file descriptor.
 225 ****************************************************************************/
 226
 227 files_struct *file_find_fd(int fd)
 228 {
 229         int count=0;
 230         files_struct *fsp;
 231
 232         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 233                 if (fsp->fh->fd == fd) {
 234                         if (count > 10) {
 235                                 DLIST_PROMOTE(Files, fsp);
 236                         }
 237                         return fsp;
 238                 }
 239         }
 240
 241         return NULL;
 242 }
 243
 244 /****************************************************************************
 245  Find a fsp given a device, inode and file_id.
 246 ****************************************************************************/
 247
 248 files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
 249 {
 250         int count=0;
 251         files_struct *fsp;
 252
 253         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 254                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 255                 if (file_id_equal(&fsp->file_id, &id) &&
 256                     fsp->fh->gen_id == gen_id ) {
 257                         if (count > 10) {
 258                                 DLIST_PROMOTE(Files, fsp);
 259                         }
 260                         /* Paranoia check. */
 261                         if ((fsp->fh->fd == -1) &&
 262                             (fsp->oplock_type != NO_OPLOCK) &&
 263                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 264                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 265 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 266                                          file_id_string_tos(&fsp->file_id),
 267                                          (unsigned int)fsp->fh->gen_id,
 268                                          (unsigned int)fsp->oplock_type ));
 269                                 smb_panic("file_find_dif");
 270                         }
 271                         return fsp;
 272                 }
 273         }
 274
 275         return NULL;
 276 }
 277
 278 /****************************************************************************
 279  Check if an fsp still exists.
 280 ****************************************************************************/
 281
 282 files_struct *file_find_fsp(files_struct *orig_fsp)
 283 {
 284         files_struct *fsp;
 285
 286         for (fsp=Files;fsp;fsp=fsp->next) {
 287                 if (fsp == orig_fsp)
 288                         return fsp;
 289         }
 290
 291         return NULL;
 292 }
 293
 294 /****************************************************************************
 295  Find the first fsp given a device and inode.
 296  We use a singleton cache here to speed up searching from getfilepathinfo
 297  calls.
 298 ****************************************************************************/
 299
 300 files_struct *file_find_di_first(struct file_id id)
 301 {
 302         files_struct *fsp;
 303
 304         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 305                 /* Positive or negative cache hit. */
 306                 return fsp_fi_cache.fsp;
 307         }
 308
 309         fsp_fi_cache.id = id;
 310
 311         for (fsp=Files;fsp;fsp=fsp->next) {
 312                 if (file_id_equal(&fsp->file_id, &id)) {
 313                         /* Setup positive cache. */
 314                         fsp_fi_cache.fsp = fsp;
 315                         return fsp;
 316                 }
 317         }
 318
 319         /* Setup negative cache. */
 320         fsp_fi_cache.fsp = NULL;
 321         return NULL;
 322 }
 323
 324 /****************************************************************************
 325  Find the next fsp having the same device and inode.
 326 ****************************************************************************/
 327
 328 files_struct *file_find_di_next(files_struct *start_fsp)
 329 {
 330         files_struct *fsp;
 331
 332         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 333                 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
 334                         return fsp;
 335                 }
 336         }
 337
 338         return NULL;
 339 }
 340
 341 /****************************************************************************
 342  Find a fsp that is open for printing.
 343 ****************************************************************************/
 344
 345 files_struct *file_find_print(void)
 346 {
 347         files_struct *fsp;
 348
 349         for (fsp=Files;fsp;fsp=fsp->next) {
 350                 if (fsp->print_file) {
 351                         return fsp;
 352                 }
 353         }
 354
 355         return NULL;
 356 }
 357
 358 /****************************************************************************
 359  Find any fsp open with a pathname below that of an already open path.
 360 ****************************************************************************/
 361
 362 bool file_find_subpath(files_struct *dir_fsp)
 363 {
 364         files_struct *fsp;
 365         size_t dlen;
 366         char *d_fullname = talloc_asprintf(talloc_tos(),
 367                                         "%s/%s",
 368                                         dir_fsp->conn->connectpath,
 369                                         dir_fsp->fsp_name);
 370
 371         if (!d_fullname) {
 372                 return false;
 373         }
 374
 375         dlen = strlen(d_fullname);
 376
 377         for (fsp=Files;fsp;fsp=fsp->next) {
 378                 char *d1_fullname;
 379
 380                 if (fsp == dir_fsp) {
 381                         continue;
 382                 }
 383
 384                 d1_fullname = talloc_asprintf(talloc_tos(),
 385                                         "%s/%s",
 386                                         fsp->conn->connectpath,
 387                                         fsp->fsp_name);
 388
 389                 if (strnequal(d_fullname, d1_fullname, dlen)) {
 390                         TALLOC_FREE(d_fullname);
 391                         TALLOC_FREE(d1_fullname);
 392                         return true;
 393                 }
 394                 TALLOC_FREE(d1_fullname);
 395         }
 396
 397         TALLOC_FREE(d_fullname);
 398         return false;
 399 }
 400
 401 /****************************************************************************
 402  Sync open files on a connection.
 403 ****************************************************************************/
 404
 405 void file_sync_all(connection_struct *conn)
 406 {
 407         files_struct *fsp, *next;
 408
 409         for (fsp=Files;fsp;fsp=next) {
 410                 next=fsp->next;
 411                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 412                         sync_file(conn, fsp, True /* write through */);
 413                 }
 414         }
 415 }
 416
 417 /****************************************************************************
 418  Free up a fsp.
 419 ****************************************************************************/
 420
 421 void file_free(struct smb_request *req, files_struct *fsp)
 422 {
 423         DLIST_REMOVE(Files, fsp);
 424
 425         string_free(&fsp->fsp_name);
 426
 427         TALLOC_FREE(fsp->fake_file_handle);
 428
 429         if (fsp->fh->ref_count == 1) {
 430                 SAFE_FREE(fsp->fh);
 431         } else {
 432                 fsp->fh->ref_count--;
 433         }
 434
 435         if (fsp->notify) {
 436                 notify_remove(fsp->conn->notify_ctx, fsp);
 437                 TALLOC_FREE(fsp->notify);
 438         }
 439
 440         /* Ensure this event will never fire. */
 441         TALLOC_FREE(fsp->oplock_timeout);
 442
 443         /* Ensure this event will never fire. */
 444         TALLOC_FREE(fsp->update_write_time_event);
 445
 446         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 447         files_used--;
 448
 449         DEBUG(5,("freed files structure %d (%d used)\n",
 450                  fsp->fnum, files_used));
 451
 452         fsp->conn->num_files_open--;
 453
 454         if ((req != NULL) && (fsp == req->chain_fsp)) {
 455                 req->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         /* Drop all remaining extensions. */
 464         while (fsp->vfs_extension) {
 465                 vfs_remove_fsp_extension(fsp->vfs_extension->owner, fsp);
 466         }
 467
 468         /* this is paranoia, just in case someone tries to reuse the
 469            information */
 470         ZERO_STRUCTP(fsp);
 471
 472         SAFE_FREE(fsp);
 473 }
 474
 475 /****************************************************************************
 476  Get an fsp from a 16 bit fnum.
 477 ****************************************************************************/
 478
 479 files_struct *file_fnum(uint16 fnum)
 480 {
 481         files_struct *fsp;
 482         int count=0;
 483
 484         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 485                 if (fsp->fnum == fnum) {
 486                         if (count > 10) {
 487                                 DLIST_PROMOTE(Files, fsp);
 488                         }
 489                         return fsp;
 490                 }
 491         }
 492         return NULL;
 493 }
 494
 495 /****************************************************************************
 496  Get an fsp from a packet given the offset of a 16 bit fnum.
 497 ****************************************************************************/
 498
 499 files_struct *file_fsp(struct smb_request *req, uint16 fid)
 500 {
 501         files_struct *fsp;
 502
 503         if ((req != NULL) && (req->chain_fsp != NULL)) {
 504                 return req->chain_fsp;
 505         }
 506
 507         fsp = file_fnum(fid);
 508         if ((fsp != NULL) && (req != NULL)) {
 509                 req->chain_fsp = fsp;
 510         }
 511         return fsp;
 512 }
 513
 514 /****************************************************************************
 515  Duplicate the file handle part for a DOS or FCB open.
 516 ****************************************************************************/
 517
 518 void dup_file_fsp(struct smb_request *req, files_struct *from,
 519                       uint32 access_mask, uint32 share_access,
 520                       uint32 create_options, files_struct *to)
 521 {
 522         SAFE_FREE(to->fh);
 523
 524         to->fh = from->fh;
 525         to->fh->ref_count++;
 526
 527         to->file_id = from->file_id;
 528         to->initial_allocation_size = from->initial_allocation_size;
 529         to->mode = from->mode;
 530         to->file_pid = from->file_pid;
 531         to->vuid = from->vuid;
 532         to->open_time = from->open_time;
 533         to->access_mask = access_mask;
 534         to->share_access = share_access;
 535         to->oplock_type = from->oplock_type;
 536         to->can_lock = from->can_lock;
 537         to->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 538         if (!CAN_WRITE(from->conn)) {
 539                 to->can_write = False;
 540         } else {
 541                 to->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 542         }
 543         to->print_file = from->print_file;
 544         to->modified = from->modified;
 545         to->is_directory = from->is_directory;
 546         to->aio_write_behind = from->aio_write_behind;
 547         string_set(&to->fsp_name,from->fsp_name);
 548 }