release/src/router/samba3/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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 static int real_max_open_files;
  24
  25 #define VALID_FNUM(fnum)   (((fnum) >= 0) && ((fnum) < real_max_open_files))
  26
  27 #define FILE_HANDLE_OFFSET 0x1000
  28
  29 static struct bitmap *file_bmap;
  30
  31 static files_struct *Files;
  32
  33 /* a fsp to use when chaining */
  34 static files_struct *chain_fsp = NULL;
  35
  36 static int files_used;
  37
  38 /* A singleton cache to speed up searching by dev/inode. */
  39 static struct fsp_singleton_cache {
  40         files_struct *fsp;
  41         SMB_DEV_T dev;
  42         SMB_INO_T inode;
  43 } fsp_fi_cache;
  44
  45 /****************************************************************************
  46  Return a unique number identifying this fsp over the life of this pid.
  47 ****************************************************************************/
  48
  49 static unsigned long get_gen_count(void)
  50 {
  51         static unsigned long file_gen_counter;
  52
  53         if ((++file_gen_counter) == 0)
  54                 return ++file_gen_counter;
  55         return file_gen_counter;
  56 }
  57
  58 /****************************************************************************
  59  Find first available file slot.
  60 ****************************************************************************/
  61
  62 files_struct *file_new(connection_struct *conn)
  63 {
  64         int i;
  65         static int first_file;
  66         files_struct *fsp;
  67
  68         /* we want to give out file handles differently on each new
  69            connection because of a common bug in MS clients where they try to
  70            reuse a file descriptor from an earlier smb connection. This code
  71            increases the chance that the errant client will get an error rather
  72            than causing corruption */
  73         if (first_file == 0) {
  74                 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
  75         }
  76
  77         /* TODO: Port the id-tree implementation from Samba4 */
  78
  79         i = bitmap_find(file_bmap, first_file);
  80         if (i == -1) {
  81                 DEBUG(0,("ERROR! Out of file structures\n"));
  82                 /* TODO: We have to unconditionally return a DOS error here,
  83                  * W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
  84                  * NTSTATUS negotiated */
  85                 set_saved_ntstatus(NT_STATUS_TOO_MANY_OPENED_FILES);
  86                 return NULL;
  87         }
  88
  89         fsp = SMB_MALLOC_P(files_struct);
  90         if (!fsp) {
  91                 set_saved_ntstatus(NT_STATUS_NO_MEMORY);
  92                 return NULL;
  93         }
  94
  95         ZERO_STRUCTP(fsp);
  96
  97         fsp->fh = SMB_MALLOC_P(struct fd_handle);
  98         if (!fsp->fh) {
  99                 SAFE_FREE(fsp);
 100                 set_saved_ntstatus(NT_STATUS_NO_MEMORY);
 101                 return NULL;
 102         }
 103
 104         ZERO_STRUCTP(fsp->fh);
 105
 106         fsp->fh->ref_count = 1;
 107         fsp->fh->fd = -1;
 108
 109         fsp->conn = conn;
 110         fsp->fh->file_id = get_gen_count();
 111         GetTimeOfDay(&fsp->open_time);
 112
 113         first_file = (i+1) % real_max_open_files;
 114
 115         bitmap_set(file_bmap, i);
 116         files_used++;
 117
 118         fsp->fnum = i + FILE_HANDLE_OFFSET;
 119         SMB_ASSERT(fsp->fnum < 65536);
 120
 121         string_set(&fsp->fsp_name,"");
 122
 123         DLIST_ADD(Files, fsp);
 124
 125         DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
 126                  i, fsp->fnum, files_used));
 127
 128         chain_fsp = fsp;
 129
 130         /* A new fsp invalidates a negative fsp_fi_cache. */
 131         if (fsp_fi_cache.fsp == NULL) {
 132                 ZERO_STRUCT(fsp_fi_cache);
 133         }
 134
 135         return fsp;
 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, fileid = %lu, dev = %x, inode = %.0f\n",
 239                         count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->file_id,
 240                         (unsigned int)fsp->dev, (double)fsp->inode ));
 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(SMB_DEV_T dev, SMB_INO_T inode, unsigned long file_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 (fsp->dev == dev &&
 277                     fsp->inode == inode &&
 278                     fsp->fh->file_id == file_id ) {
 279                         if (count > 10) {
 280                                 DLIST_PROMOTE(Files, fsp);
 281                         }
 282                         /* Paranoia check. */
 283                         if ((fsp->fh->fd == -1) &&
 284                             (fsp->oplock_type != NO_OPLOCK) &&
 285                             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
 286                                 DEBUG(0,("file_find_dif: file %s dev = %x, inode = %.0f, file_id = %u \
 287 oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name, (unsigned int)fsp->dev,
 288                                                 (double)fsp->inode, (unsigned int)fsp->fh->file_id,
 289                                                 (unsigned int)fsp->oplock_type ));
 290                                 smb_panic("file_find_dif\n");
 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(SMB_DEV_T dev, SMB_INO_T inode)
 322 {
 323         files_struct *fsp;
 324
 325         if (fsp_fi_cache.dev == dev && fsp_fi_cache.inode == inode) {
 326                 /* Positive or negative cache hit. */
 327                 return fsp_fi_cache.fsp;
 328         }
 329
 330         fsp_fi_cache.dev = dev;
 331         fsp_fi_cache.inode = inode;
 332
 333         for (fsp=Files;fsp;fsp=fsp->next) {
 334                 if ( fsp->fh->fd != -1 &&
 335                                 fsp->dev == dev &&
 336                                 fsp->inode == inode ) {
 337                         /* Setup positive cache. */
 338                         fsp_fi_cache.fsp = fsp;
 339                         return fsp;
 340                 }
 341         }
 342
 343         /* Setup negative cache. */
 344         fsp_fi_cache.fsp = NULL;
 345         return NULL;
 346 }
 347
 348 /****************************************************************************
 349  Find the next fsp having the same device and inode.
 350 ****************************************************************************/
 351
 352 files_struct *file_find_di_next(files_struct *start_fsp)
 353 {
 354         files_struct *fsp;
 355
 356         for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
 357                 if ( fsp->fh->fd != -1 &&
 358                                 fsp->dev == start_fsp->dev &&
 359                                 fsp->inode == start_fsp->inode )
 360                         return fsp;
 361         }
 362
 363         return NULL;
 364 }
 365
 366 /****************************************************************************
 367  Find a fsp that is open for printing.
 368 ****************************************************************************/
 369
 370 files_struct *file_find_print(void)
 371 {
 372         files_struct *fsp;
 373
 374         for (fsp=Files;fsp;fsp=fsp->next) {
 375                 if (fsp->print_file) {
 376                         return fsp;
 377                 }
 378         }
 379
 380         return NULL;
 381 }
 382
 383 /****************************************************************************
 384  Set a pending modtime across all files with a given dev/ino pair.
 385  Record the owner of that modtime.
 386 ****************************************************************************/
 387
 388 void fsp_set_pending_modtime(files_struct *tfsp, time_t pmod)
 389 {
 390         files_struct *fsp;
 391
 392         if (null_mtime(pmod)) {
 393                 return;
 394         }
 395
 396         for (fsp = Files;fsp;fsp=fsp->next) {
 397                 if ( fsp->fh->fd != -1 &&
 398                                 fsp->dev == tfsp->dev &&
 399                                 fsp->inode == tfsp->inode ) {
 400                         fsp->pending_modtime = pmod;
 401                         fsp->pending_modtime_owner = False;
 402                 }
 403         }
 404
 405         tfsp->pending_modtime_owner = True;
 406 }
 407
 408 /****************************************************************************
 409  Sync open files on a connection.
 410 ****************************************************************************/
 411
 412 void file_sync_all(connection_struct *conn)
 413 {
 414         files_struct *fsp, *next;
 415
 416         for (fsp=Files;fsp;fsp=next) {
 417                 next=fsp->next;
 418                 if ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
 419                         sync_file(conn, fsp, True /* write through */);
 420                 }
 421         }
 422 }
 423
 424 /****************************************************************************
 425  Free up a fsp.
 426 ****************************************************************************/
 427
 428 void file_free(files_struct *fsp)
 429 {
 430         DLIST_REMOVE(Files, fsp);
 431
 432         string_free(&fsp->fsp_name);
 433
 434         if (fsp->fake_file_handle) {
 435                 destroy_fake_file_handle(&fsp->fake_file_handle);
 436         }
 437
 438         if (fsp->fh->ref_count == 1) {
 439                 SAFE_FREE(fsp->fh);
 440         } else {
 441                 fsp->fh->ref_count--;
 442         }
 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 a fsp from a packet given the offset of a 16 bit fnum.
 468 ****************************************************************************/
 469
 470 files_struct *file_fsp(char *buf, int where)
 471 {
 472         int fnum, count=0;
 473         files_struct *fsp;
 474
 475         if (chain_fsp)
 476                 return chain_fsp;
 477
 478         if (!buf)
 479                 return NULL;
 480         fnum = SVAL(buf, where);
 481
 482         for (fsp=Files;fsp;fsp=fsp->next, count++) {
 483                 if (fsp->fnum == fnum) {
 484                         chain_fsp = fsp;
 485                         if (count > 10) {
 486                                 DLIST_PROMOTE(Files, fsp);
 487                         }
 488                         return fsp;
 489                 }
 490         }
 491         return NULL;
 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 files_struct *dup_file_fsp(files_struct *fsp,
 508                                 uint32 access_mask,
 509                                 uint32 share_access,
 510                                 uint32 create_options)
 511 {
 512         files_struct *dup_fsp = file_new(fsp->conn);
 513
 514         if (!dup_fsp) {
 515                 return NULL;
 516         }
 517
 518         SAFE_FREE(dup_fsp->fh);
 519
 520         dup_fsp->fh = fsp->fh;
 521         dup_fsp->fh->ref_count++;
 522
 523         dup_fsp->dev = fsp->dev;
 524         dup_fsp->inode = fsp->inode;
 525         dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
 526         dup_fsp->mode = fsp->mode;
 527         dup_fsp->file_pid = fsp->file_pid;
 528         dup_fsp->vuid = fsp->vuid;
 529         dup_fsp->open_time = fsp->open_time;
 530         dup_fsp->access_mask = access_mask;
 531         dup_fsp->share_access = share_access;
 532         dup_fsp->pending_modtime_owner = fsp->pending_modtime_owner;
 533         dup_fsp->pending_modtime = fsp->pending_modtime;
 534         dup_fsp->last_write_time = fsp->last_write_time;
 535         dup_fsp->oplock_type = fsp->oplock_type;
 536         dup_fsp->can_lock = fsp->can_lock;
 537         dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
 538         if (!CAN_WRITE(fsp->conn)) {
 539                 dup_fsp->can_write = False;
 540         } else {
 541                 dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
 542         }
 543         dup_fsp->print_file = fsp->print_file;
 544         dup_fsp->modified = fsp->modified;
 545         dup_fsp->is_directory = fsp->is_directory;
 546         dup_fsp->is_stat = fsp->is_stat;
 547         dup_fsp->aio_write_behind = fsp->aio_write_behind;
 548         string_set(&dup_fsp->fsp_name,fsp->fsp_name);
 549
 550         return dup_fsp;
 551 }