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 void file_init(void)
 159 {
 160         int request_max_open_files = lp_max_open_files();
 161         int real_lim;
 162
 163         /*
 164          * Set the max_open files to be the requested
 165          * max plus a fudgefactor to allow for the extra
 166          * fd's we need such as log files etc...
 167          */
 168         real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
 169
 170         real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
 171
 172         if (real_max_open_files + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
 173                 real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
 174
 175         if(real_max_open_files != request_max_open_files) {
 176                 DEBUG(1,("file_init: Information only: requested %d \
 177 open files, %d are available.\n", request_max_open_files, real_max_open_files));
 178         }
 179
 180         SMB_ASSERT(real_max_open_files > 100);
 181
 182         file_bmap = bitmap_allocate(real_max_open_files);
 183
 184         if (!file_bmap) {
 185                 exit_server("out of memory in file_init");
 186         }
 187 }
 188
 189 /****************************************************************************
 190  Close files open by a specified vuid.
 191 ****************************************************************************/
 192
 193 void file_close_user(int vuid)
 194 {
 195         files_struct *fsp, *next;
 196
 197         for (fsp=Files;fsp;fsp=next) {
 198                 next=fsp->next;
 199                 if (fsp->vuid == vuid) {
 200                         close_file(NULL, fsp, SHUTDOWN_CLOSE);
 201                 }
 202         }
 203 }
 204
 205 /*
 206  * Walk the files table until "fn" returns non-NULL
 207  */
 208
 209 struct files_struct *file_walk_table(
 210         struct files_struct *(*fn)(struct files_struct *fsp,
 211                                    void *private_data),
 212         void *private_data)
 213 {
 214         struct files_struct *fsp, *next;
 215
 216         for (fsp = Files; fsp; fsp = next) {
 217                 struct files_struct *ret;
 218                 next = fsp->next;
 219                 ret = fn(fsp, private_data);
 220                 if (ret != NULL) {
 221                         return ret;
 222                 }
 223         }
 224         return NULL;
 225 }
 226
 227 /****************************************************************************
 228  Debug to enumerate all open files in the smbd.
 229 ****************************************************************************/
 230
 231 void file_dump_open_table(void)
 232 {
 233         int count=0;
 234         files_struct *fsp;
 235
 236         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 237                 DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
 238                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
 239                           file_id_string_tos(&fsp->file_id)));
 240         }
 241 }
 242
 243 /****************************************************************************
 244  Find a fsp given a file descriptor.
 245 ****************************************************************************/
 246
 247 files_struct *file_find_fd(int fd)
 248 {
 249         int count=0;
 250         files_struct *fsp;
 251
 252         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 253                 if (fsp->fh->fd == fd) {
 254                         if (count > 10) {
 255                                 DLIST_PROMOTE(Files, fsp);
 256                         }
 257                         return fsp;
 258                 }
 259         }
 260
 261         return NULL;
 262 }
 263
 264 /****************************************************************************
 265  Find a fsp given a device, inode and file_id.
 266 ****************************************************************************/
 267
 268 files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
 269 {
 270         int count=0;
 271         files_struct *fsp;
 272
 273         for (fsp=Files;fsp;fsp=fsp->next,count++) {
 274                 /* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
 275                 if (file_id_equal(&fsp->file_id, &id) &&
 276                     fsp->fh->gen_id == gen_id ) {
 277                         if (count > 10) {
 278                                 DLIST_PROMOTE(Files, fsp);
 279                         }
 280                         /* Paranoia check. */
 281                         if ((fsp->fh->fd == -1) &&
 282                             (fsp->oplock_type != NO_OPLOCK) &&
 283                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 284                                 DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
 285 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
 286                                          file_id_string_tos(&fsp->file_id),
 287                                          (unsigned int)fsp->fh->gen_id,
 288                                          (unsigned int)fsp->oplock_type ));
 289                                 smb_panic("file_find_dif");
 290                         }
 291                         return fsp;
 292                 }
 293         }
 294
 295         return NULL;
 296 }
 297
 298 /****************************************************************************
 299  Check if an fsp still exists.
 300 ****************************************************************************/
 301
 302 files_struct *file_find_fsp(files_struct *orig_fsp)
 303 {
 304         files_struct *fsp;
 305
 306         for (fsp=Files;fsp;fsp=fsp->next) {
 307                 if (fsp == orig_fsp)
 308                         return fsp;
 309         }
 310
 311         return NULL;
 312 }
 313
 314 /****************************************************************************
 315  Find the first fsp given a device and inode.
 316  We use a singleton cache here to speed up searching from getfilepathinfo
 317  calls.
 318 ****************************************************************************/
 319
 320 files_struct *file_find_di_first(struct file_id id)
 321 {
 322         files_struct *fsp;
 323
 324         if (file_id_equal(&fsp_fi_cache.id, &id)) {
 325                 /* Positive or negative cache hit. */
 326                 return fsp_fi_cache.fsp;
 327         }
 328
 329         fsp_fi_cache.id = id;
 330
 331         for (fsp=Files;fsp;fsp=fsp->next) {
 332                 if (file_id_equal(&fsp->file_id, &id)) {
 333                         /* Setup positive cache. */
 334                         fsp_fi_cache.fsp = fsp;
 335                         return fsp;
 336                 }
 337         }
 338
 339         /* Setup negative cache. */
 340         fsp_fi_cache.fsp = NULL;
 341         return NULL;
 342 }
 343
 344 /****************************************************************************
 345  Find the next fsp having the same device and inode.
 346 ****************************************************************************/
 347
 348 files_struct *file_find_di_next(files_struct *start_fsp)
 349 {
 350         files_struct *fsp;
 351
 352         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 353                 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
 354                         return fsp;
 355                 }
 356         }
 357
 358         return NULL;
 359 }
 360
 361 /****************************************************************************
 362  Find a fsp that is open for printing.
 363 ****************************************************************************/
 364
 365 files_struct *file_find_print(void)
 366 {
 367         files_struct *fsp;
 368
 369         for (fsp=Files;fsp;fsp=fsp->next) {
 370                 if (fsp->print_file) {
 371                         return fsp;
 372                 }
 373         }
 374
 375         return NULL;
 376 }
 377
 378 /****************************************************************************
 379  Find any fsp open with a pathname below that of an already open path.
 380 ****************************************************************************/
 381
 382 bool file_find_subpath(files_struct *dir_fsp)
 383 {
 384         files_struct *fsp;
 385         size_t dlen;
 386         char *d_fullname = talloc_asprintf(talloc_tos(),
 387                                         "%s/%s",
 388                                         dir_fsp->conn->connectpath,
 389                                         dir_fsp->fsp_name);
 390         if (!d_fullname) {
 391                 return false;
 392         }
 393
 394         dlen = strlen(d_fullname);
 395
 396         for (fsp=Files;fsp;fsp=fsp->next) {
 397                 char *d1_fullname;
 398
 399                 if (fsp == dir_fsp) {
 400                         continue;
 401                 }
 402
 403                 d1_fullname = talloc_asprintf(talloc_tos(),
 404                                         "%s/%s",
 405                                         fsp->conn->connectpath,
 406                                         fsp->fsp_name);
 407
 408                 /*
 409                  * If the open file has a path that is a longer
 410                  * component, then it's a subpath.
 411                  */
 412                 if (strnequal(d_fullname, d1_fullname, dlen) &&
 413                                 (d1_fullname[dlen] == '/')) {
 414                         TALLOC_FREE(d1_fullname);
 415                         TALLOC_FREE(d_fullname);
 416                         return true;
 417                 }
 418                 TALLOC_FREE(d1_fullname);
 419         }
 420
 421         TALLOC_FREE(d_fullname);
 422         return false;
 423 }
 424
 425 /****************************************************************************
 426  Sync open files on a connection.
 427 ****************************************************************************/
 428
 429 void file_sync_all(connection_struct *conn)
 430 {
 431         files_struct *fsp, *next;
 432
 433         for (fsp=Files;fsp;fsp=next) {
 434                 next=fsp->next;
 435                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 436                         sync_file(conn, fsp, True /* write through */);
 437                 }
 438         }
 439 }
 440
 441 /****************************************************************************
 442  Free up a fsp.
 443 ****************************************************************************/
 444
 445 void file_free(struct smb_request *req, files_struct *fsp)
 446 {
 447         DLIST_REMOVE(Files, fsp);
 448
 449         string_free(&fsp->fsp_name);
 450
 451         TALLOC_FREE(fsp->fake_file_handle);
 452
 453         if (fsp->fh->ref_count == 1) {
 454                 SAFE_FREE(fsp->fh);
 455         } else {
 456                 fsp->fh->ref_count--;
 457         }
 458
 459         if (fsp->notify) {
 460                 notify_remove(fsp->conn->notify_ctx, fsp);
 461                 TALLOC_FREE(fsp->notify);
 462         }
 463
 464         /* Ensure this event will never fire. */
 465         TALLOC_FREE(fsp->oplock_timeout);
 466
 467         /* Ensure this event will never fire. */
 468         TALLOC_FREE(fsp->update_write_time_event);
 469
 470         bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
 471         files_used--;
 472
 473         DEBUG(5,("freed files structure %d (%d used)\n",
 474                  fsp->fnum, files_used));
 475
 476         fsp->conn->num_files_open--;
 477
 478         if ((req != NULL) && (fsp == req->chain_fsp)) {
 479                 req->chain_fsp = NULL;
 480         }
 481
 482         /* Closing a file can invalidate the positive cache. */
 483         if (fsp == fsp_fi_cache.fsp) {
 484                 ZERO_STRUCT(fsp_fi_cache);
 485         }
 486
 487         /* Drop all remaining extensions. */
 488         while (fsp->vfs_extension) {
 489                 vfs_remove_fsp_extension(fsp->vfs_extension->owner, fsp);
 490         }
 491
 492         /* this is paranoia, just in case someone tries to reuse the
 493            information */
 494         ZERO_STRUCTP(fsp);
 495
 496         SAFE_FREE(fsp);
 497 }
 498
 499 /****************************************************************************
 500  Get an fsp from a 16 bit fnum.
 501 ****************************************************************************/
 502
 503 files_struct *file_fnum(uint16 fnum)
 504 {
 505         files_struct *fsp;
 506         int count=0;
 507
 508         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 509                 if (fsp->fnum == fnum) {
 510                         if (count > 10) {
 511                                 DLIST_PROMOTE(Files, fsp);
 512                         }
 513                         return fsp;
 514                 }
 515         }
 516         return NULL;
 517 }
 518
 519 /****************************************************************************
 520  Get an fsp from a packet given the offset of a 16 bit fnum.
 521 ****************************************************************************/
 522
 523 files_struct *file_fsp(struct smb_request *req, uint16 fid)
 524 {
 525         files_struct *fsp;
 526
 527         if ((req != NULL) && (req->chain_fsp != NULL)) {
 528                 return req->chain_fsp;
 529         }
 530
 531         fsp = file_fnum(fid);
 532         if ((fsp != NULL) && (req != NULL)) {
 533                 req->chain_fsp = fsp;
 534         }
 535         return fsp;
 536 }
 537
 538 /****************************************************************************
 539  Duplicate the file handle part for a DOS or FCB open.
 540 ****************************************************************************/
 541
 542 void dup_file_fsp(struct smb_request *req, files_struct *from,
 543                       uint32 access_mask, uint32 share_access,
 544                       uint32 create_options, files_struct *to)
 545 {
 546         SAFE_FREE(to->fh);
 547
 548         to->fh = from->fh;
 549         to->fh->ref_count++;
 550
 551         to->file_id = from->file_id;
 552         to->initial_allocation_size = from->initial_allocation_size;
 553         to->mode = from->mode;
 554         to->file_pid = from->file_pid;
 555         to->vuid = from->vuid;
 556         to->open_time = from->open_time;
 557         to->access_mask = access_mask;
 558         to->share_access = share_access;
 559         to->oplock_type = from->oplock_type;
 560         to->can_lock = from->can_lock;
 561         to->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 562         if (!CAN_WRITE(from->conn)) {
 563                 to->can_write = False;
 564         } else {
 565                 to->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 566         }
 567         to->print_file = from->print_file;
 568         to->modified = from->modified;
 569         to->is_directory = from->is_directory;
 570         to->aio_write_behind = from->aio_write_behind;
 571         string_set(&to->fsp_name,from->fsp_name);
 572 }