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 static int files_used;
  33
  34 /* A singleton cache to speed up searching by dev/inode. */
  35 static struct fsp_singleton_cache {
  36         files_struct *fsp;
  37         struct file_id id;
  38 } fsp_fi_cache;
  39
  40 /****************************************************************************
  41  Return a unique number identifying this fsp over the life of this pid.
  42 ****************************************************************************/
  43
  44 static unsigned long get_gen_count(void)
  45 {
  46         static unsigned long file_gen_counter;
  47
  48         if ((++file_gen_counter) == 0)
  49                 return ++file_gen_counter;
  50         return file_gen_counter;
  51 }
  52
  53 /****************************************************************************
  54  Find first available file slot.
  55 ****************************************************************************/
  56
  57 NTSTATUS file_new(struct smb_request *req, connection_struct *conn,
  58                   files_struct **result)
  59 {
  60         int i;
  61         static int first_file;
  62         files_struct *fsp;
  63
  64         /* we want to give out file handles differently on each new
  65            connection because of a common bug in MS clients where they try to
  66            reuse a file descriptor from an earlier smb connection. This code
  67            increases the chance that the errant client will get an error rather
  68            than causing corruption */
  69         if (first_file == 0) {
  70                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  71         }
  72
  73         /* TODO: Port the id-tree implementation from Samba4 */
  74
  75         i = bitmap_find(file_bmap, first_file);
  76         if (i == -1) {
  77                 DEBUG(0,("ERROR! Out of file structures\n"));
  78                 /* TODO: We have to unconditionally return a DOS error here,
  79                  * W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
  80                  * NTSTATUS negotiated */
  81                 return NT_STATUS_TOO_MANY_OPENED_FILES;
  82         }
  83
  84         fsp = SMB_MALLOC_P(files_struct);
  85         if (!fsp) {
  86                 return NT_STATUS_NO_MEMORY;
  87         }
  88
  89         ZERO_STRUCTP(fsp);
  90
  91         fsp->fh = SMB_MALLOC_P(struct fd_handle);
  92         if (!fsp->fh) {
  93                 SAFE_FREE(fsp);
  94                 return NT_STATUS_NO_MEMORY;
  95         }
  96
  97         ZERO_STRUCTP(fsp->fh);
  98
  99         fsp->fh->ref_count = 1;
 100         fsp->fh->fd = -1;
 101
 102         fsp->conn = conn;
 103         fsp->fh->gen_id = get_gen_count();
 104         GetTimeOfDay(&fsp->open_time);
 105
 106         first_file = (i+1) % real_max_open_files;
 107
 108         bitmap_set(file_bmap, i);
 109         files_used++;
 110
 111         fsp->fnum = i + FILE_HANDLE_OFFSET;
 112         SMB_ASSERT(fsp->fnum < 65536);
 113
 114         string_set(&fsp->fsp_name,"");
 115
 116         DLIST_ADD(Files, fsp);
 117
 118         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 119                  i, fsp->fnum, files_used));
 120
 121         if (req != NULL) {
 122                 req->chain_fsp = fsp;
 123         }
 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(NULL, 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(NULL, 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 /****************************************************************************
 208  Close files open by a specified vuid.
 209 ****************************************************************************/
 210
 211 void file_close_user(int vuid)
 212 {
 213         files_struct *fsp, *next;
 214
 215         for (fsp=Files;fsp;fsp=next) {
 216                 next=fsp->next;
 217                 if (fsp->vuid == vuid) {
 218                         close_file(NULL, fsp, SHUTDOWN_CLOSE);
 219                 }
 220         }
 221 }
 222
 223 /****************************************************************************
 224  Debug to enumerate all open files in the smbd.
 225 ****************************************************************************/
 226
 227 void file_dump_open_table(void)
 228 {
 229         int count=0;
 230         files_struct *fsp;
 231
 232         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 233                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
 234                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 235                           file_id_string_tos(&fsp->file_id)));
 236         }
 237 }
 238
 239 /****************************************************************************
 240  Find a fsp given a file descriptor.
 241 ****************************************************************************/
 242
 243 files_struct *file_find_fd(int fd)
 244 {
 245         int count=0;
 246         files_struct *fsp;
 247
 248         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 249                 if (fsp->fh->fd == fd) {
 250                         if (count > 10) {
 251                                 DLIST_PROMOTE(Files, fsp);
 252                         }
 253                         return fsp;
 254                 }
 255         }
 256
 257         return NULL;
 258 }
 259
 260 /****************************************************************************
 261  Find a fsp given a device, inode and file_id.
 262 ****************************************************************************/
 263
 264 files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
 265 {
 266         int count=0;
 267         files_struct *fsp;
 268
 269         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 270                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 271                 if (file_id_equal(&fsp->file_id, &id) &&
 272                     fsp->fh->gen_id == gen_id ) {
 273                         if (count > 10) {
 274                                 DLIST_PROMOTE(Files, fsp);
 275                         }
 276                         /* Paranoia check. */
 277                         if ((fsp->fh->fd == -1) &&
 278                             (fsp->oplock_type != NO_OPLOCK) &&
 279                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 280                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 281 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 282                                          file_id_string_tos(&fsp->file_id),
 283                                          (unsigned int)fsp->fh->gen_id,
 284                                          (unsigned int)fsp->oplock_type ));
 285                                 smb_panic("file_find_dif");
 286                         }
 287                         return fsp;
 288                 }
 289         }
 290
 291         return NULL;
 292 }
 293
 294 /****************************************************************************
 295  Check if an fsp still exists.
 296 ****************************************************************************/
 297
 298 files_struct *file_find_fsp(files_struct *orig_fsp)
 299 {
 300         files_struct *fsp;
 301
 302         for (fsp=Files;fsp;fsp=fsp->next) {
 303                 if (fsp == orig_fsp)
 304                         return fsp;
 305         }
 306
 307         return NULL;
 308 }
 309
 310 /****************************************************************************
 311  Find the first fsp given a device and inode.
 312  We use a singleton cache here to speed up searching from getfilepathinfo
 313  calls.
 314 ****************************************************************************/
 315
 316 files_struct *file_find_di_first(struct file_id id)
 317 {
 318         files_struct *fsp;
 319
 320         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 321                 /* Positive or negative cache hit. */
 322                 return fsp_fi_cache.fsp;
 323         }
 324
 325         fsp_fi_cache.id = id;
 326
 327         for (fsp=Files;fsp;fsp=fsp->next) {
 328                 if (file_id_equal(&fsp->file_id, &id)) {
 329                         /* Setup positive cache. */
 330                         fsp_fi_cache.fsp = fsp;
 331                         return fsp;
 332                 }
 333         }
 334
 335         /* Setup negative cache. */
 336         fsp_fi_cache.fsp = NULL;
 337         return NULL;
 338 }
 339
 340 /****************************************************************************
 341  Find the next fsp having the same device and inode.
 342 ****************************************************************************/
 343
 344 files_struct *file_find_di_next(files_struct *start_fsp)
 345 {
 346         files_struct *fsp;
 347
 348         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 349                 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
 350                         return fsp;
 351                 }
 352         }
 353
 354         return NULL;
 355 }
 356
 357 /****************************************************************************
 358  Find a fsp that is open for printing.
 359 ****************************************************************************/
 360
 361 files_struct *file_find_print(void)
 362 {
 363         files_struct *fsp;
 364
 365         for (fsp=Files;fsp;fsp=fsp->next) {
 366                 if (fsp->print_file) {
 367                         return fsp;
 368                 }
 369         }
 370
 371         return NULL;
 372 }
 373
 374 /****************************************************************************
 375  Sync open files on a connection.
 376 ****************************************************************************/
 377
 378 void file_sync_all(connection_struct *conn)
 379 {
 380         files_struct *fsp, *next;
 381
 382         for (fsp=Files;fsp;fsp=next) {
 383                 next=fsp->next;
 384                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 385                         sync_file(conn, fsp, True /* write through */);
 386                 }
 387         }
 388 }
 389
 390 /****************************************************************************
 391  Free up a fsp.
 392 ****************************************************************************/
 393
 394 void file_free(struct smb_request *req, files_struct *fsp)
 395 {
 396         DLIST_REMOVE(Files, fsp);
 397
 398         string_free(&fsp->fsp_name);
 399
 400         TALLOC_FREE(fsp->fake_file_handle);
 401
 402         if (fsp->fh->ref_count == 1) {
 403                 SAFE_FREE(fsp->fh);
 404         } else {
 405                 fsp->fh->ref_count--;
 406         }
 407
 408         if (fsp->notify) {
 409                 notify_remove(fsp->conn->notify_ctx, fsp);
 410                 TALLOC_FREE(fsp->notify);
 411         }
 412
 413         /* Ensure this event will never fire. */
 414         TALLOC_FREE(fsp->oplock_timeout);
 415
 416         /* Ensure this event will never fire. */
 417         TALLOC_FREE(fsp->update_write_time_event);
 418
 419         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 420         files_used--;
 421
 422         DEBUG(5,("freed files structure %d (%d used)\n",
 423                  fsp->fnum, files_used));
 424
 425         fsp->conn->num_files_open--;
 426
 427         if ((req != NULL) && (fsp == req->chain_fsp)) {
 428                 req->chain_fsp = NULL;
 429         }
 430
 431         /* Closing a file can invalidate the positive cache. */
 432         if (fsp == fsp_fi_cache.fsp) {
 433                 ZERO_STRUCT(fsp_fi_cache);
 434         }
 435
 436         /* Drop all remaining extensions. */
 437         while (fsp->vfs_extension) {
 438                 vfs_remove_fsp_extension(fsp->vfs_extension->owner, fsp);
 439         }
 440
 441         /* this is paranoia, just in case someone tries to reuse the
 442            information */
 443         ZERO_STRUCTP(fsp);
 444
 445         SAFE_FREE(fsp);
 446 }
 447
 448 /****************************************************************************
 449  Get an fsp from a 16 bit fnum.
 450 ****************************************************************************/
 451
 452 files_struct *file_fnum(uint16 fnum)
 453 {
 454         files_struct *fsp;
 455         int count=0;
 456
 457         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 458                 if (fsp->fnum == fnum) {
 459                         if (count > 10) {
 460                                 DLIST_PROMOTE(Files, fsp);
 461                         }
 462                         return fsp;
 463                 }
 464         }
 465         return NULL;
 466 }
 467
 468 /****************************************************************************
 469  Get an fsp from a packet given the offset of a 16 bit fnum.
 470 ****************************************************************************/
 471
 472 files_struct *file_fsp(struct smb_request *req, uint16 fid)
 473 {
 474         files_struct *fsp;
 475
 476         if ((req != NULL) && (req->chain_fsp != NULL)) {
 477                 return req->chain_fsp;
 478         }
 479
 480         fsp = file_fnum(fid);
 481         if ((fsp != NULL) && (req != NULL)) {
 482                 req->chain_fsp = fsp;
 483         }
 484         return fsp;
 485 }
 486
 487 /****************************************************************************
 488  Duplicate the file handle part for a DOS or FCB open.
 489 ****************************************************************************/
 490
 491 void dup_file_fsp(struct smb_request *req, files_struct *from,
 492                       uint32 access_mask, uint32 share_access,
 493                       uint32 create_options, files_struct *to)
 494 {
 495         SAFE_FREE(to->fh);
 496
 497         to->fh = from->fh;
 498         to->fh->ref_count++;
 499
 500         to->file_id = from->file_id;
 501         to->initial_allocation_size = from->initial_allocation_size;
 502         to->mode = from->mode;
 503         to->file_pid = from->file_pid;
 504         to->vuid = from->vuid;
 505         to->open_time = from->open_time;
 506         to->access_mask = access_mask;
 507         to->share_access = share_access;
 508         to->oplock_type = from->oplock_type;
 509         to->can_lock = from->can_lock;
 510         to->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 511         if (!CAN_WRITE(from->conn)) {
 512                 to->can_write = False;
 513         } else {
 514                 to->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 515         }
 516         to->print_file = from->print_file;
 517         to->modified = from->modified;
 518         to->is_directory = from->is_directory;
 519         to->aio_write_behind = from->aio_write_behind;
 520         string_set(&to->fsp_name,from->fsp_name);
 521 }