server/file.c

   1 /*
   2  * Server-side file management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <fcntl.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <stdlib.h>
  30 #include <errno.h>
  31 #ifdef HAVE_SYS_ERRNO_H
  32 #include <sys/errno.h>
  33 #endif
  34 #include <sys/stat.h>
  35 #include <sys/time.h>
  36 #include <sys/types.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39 #ifdef HAVE_UTIME_H
  40 #include <utime.h>
  41 #endif
  42 #ifdef HAVE_POLL_H
  43 #include <poll.h>
  44 #endif
  45
  46 #include "ntstatus.h"
  47 #define WIN32_NO_STATUS
  48 #include "windef.h"
  49 #include "winternl.h"
  50
  51 #include "file.h"
  52 #include "handle.h"
  53 #include "thread.h"
  54 #include "request.h"
  55 #include "process.h"
  56 #include "security.h"
  57
  58 struct file
  59 {
  60     struct object       obj;        /* object header */
  61     struct fd          *fd;         /* file descriptor for this file */
  62     unsigned int        access;     /* file access (FILE_READ_DATA etc.) */
  63     mode_t              mode;       /* file stat.st_mode */
  64     uid_t               uid;        /* file stat.st_uid */
  65 };
  66
  67 static unsigned int generic_file_map_access( unsigned int access );
  68
  69 static void file_dump( struct object *obj, int verbose );
  70 static struct fd *file_get_fd( struct object *obj );
  71 static struct security_descriptor *file_get_sd( struct object *obj );
  72 static int file_set_sd( struct object *obj, const struct security_descriptor *sd, unsigned int set_info );
  73 static void file_destroy( struct object *obj );
  74
  75 static int file_get_poll_events( struct fd *fd );
  76 static void file_flush( struct fd *fd, struct event **event );
  77 static enum server_fd_type file_get_fd_type( struct fd *fd );
  78
  79 static const struct object_ops file_ops =
  80 {
  81     sizeof(struct file),          /* size */
  82     file_dump,                    /* dump */
  83     no_get_type,                  /* get_type */
  84     add_queue,                    /* add_queue */
  85     remove_queue,                 /* remove_queue */
  86     default_fd_signaled,          /* signaled */
  87     no_satisfied,                 /* satisfied */
  88     no_signal,                    /* signal */
  89     file_get_fd,                  /* get_fd */
  90     default_fd_map_access,        /* map_access */
  91     file_get_sd,                  /* get_sd */
  92     file_set_sd,                  /* set_sd */
  93     no_lookup_name,               /* lookup_name */
  94     no_open_file,                 /* open_file */
  95     fd_close_handle,              /* close_handle */
  96     file_destroy                  /* destroy */
  97 };
  98
  99 static const struct fd_ops file_fd_ops =
 100 {
 101     file_get_poll_events,         /* get_poll_events */
 102     default_poll_event,           /* poll_event */
 103     file_flush,                   /* flush */
 104     file_get_fd_type,             /* get_fd_type */
 105     default_fd_ioctl,             /* ioctl */
 106     default_fd_queue_async,       /* queue_async */
 107     default_fd_reselect_async,    /* reselect_async */
 108     default_fd_cancel_async       /* cancel_async */
 109 };
 110
 111 static inline int is_overlapped( const struct file *file )
 112 {
 113     return !(get_fd_options( file->fd ) & (FILE_SYNCHRONOUS_IO_ALERT | FILE_SYNCHRONOUS_IO_NONALERT));
 114 }
 115
 116 /* create a file from a file descriptor */
 117 /* if the function fails the fd is closed */
 118 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing )
 119 {
 120     struct file *file;
 121     struct stat st;
 122
 123     if (fstat( fd, &st ) == -1)
 124     {
 125         file_set_error();
 126         return NULL;
 127     }
 128
 129     if ((file = alloc_object( &file_ops )))
 130     {
 131         file->mode = st.st_mode;
 132         file->access = default_fd_map_access( &file->obj, access );
 133         if (!(file->fd = create_anonymous_fd( &file_fd_ops, fd, &file->obj,
 134                                               FILE_SYNCHRONOUS_IO_NONALERT )))
 135         {
 136             release_object( file );
 137             return NULL;
 138         }
 139     }
 140     return file;
 141 }
 142
 143 static struct object *create_file_obj( struct fd *fd, unsigned int access, mode_t mode )
 144 {
 145     struct file *file = alloc_object( &file_ops );
 146
 147     if (!file) return NULL;
 148     file->access  = access;
 149     file->mode    = mode;
 150     file->uid     = ~(uid_t)0;
 151     file->fd      = fd;
 152     grab_object( fd );
 153     set_fd_user( fd, &file_fd_ops, &file->obj );
 154     return &file->obj;
 155 }
 156
 157 static struct object *create_file( const char *nameptr, data_size_t len, unsigned int access,
 158                                    unsigned int sharing, int create, unsigned int options,
 159                                    unsigned int attrs, const struct security_descriptor *sd )
 160 {
 161     struct object *obj = NULL;
 162     struct fd *fd;
 163     int flags;
 164     char *name;
 165     mode_t mode;
 166
 167     if (!(name = mem_alloc( len + 1 ))) return NULL;
 168     memcpy( name, nameptr, len );
 169     name[len] = 0;
 170
 171     switch(create)
 172     {
 173     case FILE_CREATE:       flags = O_CREAT | O_EXCL; break;
 174     case FILE_OVERWRITE_IF: /* FIXME: the difference is whether we trash existing attr or not */
 175     case FILE_SUPERSEDE:    flags = O_CREAT | O_TRUNC; break;
 176     case FILE_OPEN:         flags = 0; break;
 177     case FILE_OPEN_IF:      flags = O_CREAT; break;
 178     case FILE_OVERWRITE:    flags = O_TRUNC; break;
 179     default:                set_error( STATUS_INVALID_PARAMETER ); goto done;
 180     }
 181
 182     if (sd)
 183     {
 184         const SID *owner = sd_get_owner( sd );
 185         if (!owner)
 186             owner = token_get_user( current->process->token );
 187         mode = sd_to_mode( sd, owner );
 188     }
 189     else
 190         mode = (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666;
 191
 192     if (len >= 4 &&
 193         (!strcasecmp( name + len - 4, ".exe" ) || !strcasecmp( name + len - 4, ".com" )))
 194     {
 195         if (mode & S_IRUSR)
 196             mode |= S_IXUSR;
 197         if (mode & S_IRGRP)
 198             mode |= S_IXGRP;
 199         if (mode & S_IROTH)
 200             mode |= S_IXOTH;
 201     }
 202
 203     access = generic_file_map_access( access );
 204
 205     /* FIXME: should set error to STATUS_OBJECT_NAME_COLLISION if file existed before */
 206     fd = open_fd( name, flags | O_NONBLOCK | O_LARGEFILE, &mode, access, sharing, options );
 207     if (!fd) goto done;
 208
 209     if (S_ISDIR(mode))
 210         obj = create_dir_obj( fd, access, mode );
 211     else if (S_ISCHR(mode) && is_serial_fd( fd ))
 212         obj = create_serial( fd );
 213     else
 214         obj = create_file_obj( fd, access, mode );
 215
 216     release_object( fd );
 217
 218 done:
 219     free( name );
 220     return obj;
 221 }
 222
 223 /* check if two file objects point to the same file */
 224 int is_same_file( struct file *file1, struct file *file2 )
 225 {
 226     return is_same_file_fd( file1->fd, file2->fd );
 227 }
 228
 229 /* create a temp file for anonymous mappings */
 230 struct file *create_temp_file( int access )
 231 {
 232     char tmpfn[16];
 233     int fd;
 234
 235     sprintf( tmpfn, "anonmap.XXXXXX" );  /* create it in the server directory */
 236     fd = mkstemps( tmpfn, 0 );
 237     if (fd == -1)
 238     {
 239         file_set_error();
 240         return NULL;
 241     }
 242     unlink( tmpfn );
 243     return create_file_for_fd( fd, access, 0 );
 244 }
 245
 246 static void file_dump( struct object *obj, int verbose )
 247 {
 248     struct file *file = (struct file *)obj;
 249     assert( obj->ops == &file_ops );
 250     fprintf( stderr, "File fd=%p\n", file->fd );
 251 }
 252
 253 static int file_get_poll_events( struct fd *fd )
 254 {
 255     struct file *file = get_fd_user( fd );
 256     int events = 0;
 257     assert( file->obj.ops == &file_ops );
 258     if (file->access & FILE_UNIX_READ_ACCESS) events |= POLLIN;
 259     if (file->access & FILE_UNIX_WRITE_ACCESS) events |= POLLOUT;
 260     return events;
 261 }
 262
 263 static void file_flush( struct fd *fd, struct event **event )
 264 {
 265     int unix_fd = get_unix_fd( fd );
 266     if (unix_fd != -1 && fsync( unix_fd ) == -1) file_set_error();
 267 }
 268
 269 static enum server_fd_type file_get_fd_type( struct fd *fd )
 270 {
 271     struct file *file = get_fd_user( fd );
 272
 273     if (S_ISREG(file->mode) || S_ISBLK(file->mode)) return FD_TYPE_FILE;
 274     if (S_ISDIR(file->mode)) return FD_TYPE_DIR;
 275     return FD_TYPE_CHAR;
 276 }
 277
 278 static struct fd *file_get_fd( struct object *obj )
 279 {
 280     struct file *file = (struct file *)obj;
 281     assert( obj->ops == &file_ops );
 282     return (struct fd *)grab_object( file->fd );
 283 }
 284
 285 static unsigned int generic_file_map_access( unsigned int access )
 286 {
 287     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 288     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 289     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 290     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 291     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 292 }
 293
 294 struct security_descriptor *mode_to_sd( mode_t mode, const SID *user, const SID *group )
 295 {
 296     struct security_descriptor *sd;
 297     size_t dacl_size;
 298     ACE_HEADER *current_ace;
 299     ACCESS_ALLOWED_ACE *aaa;
 300     ACL *dacl;
 301     SID *sid;
 302     char *ptr;
 303     const SID *world_sid = security_world_sid;
 304     const SID *local_system_sid = security_local_system_sid;
 305
 306     dacl_size = sizeof(ACL) + FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 307         FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]);
 308     if (mode & S_IRWXU)
 309         dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 310             FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 311     if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) ||
 312         (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) ||
 313         (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH))))
 314         dacl_size += FIELD_OFFSET(ACCESS_DENIED_ACE, SidStart) +
 315             FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 316     if (mode & S_IRWXO)
 317         dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 318             FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]);
 319
 320     sd = mem_alloc( sizeof(struct security_descriptor) +
 321                     FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) +
 322                     FIELD_OFFSET(SID, SubAuthority[group->SubAuthorityCount]) +
 323                     dacl_size );
 324     if (!sd) return sd;
 325
 326     sd->control = SE_DACL_PRESENT;
 327     sd->owner_len = FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 328     sd->group_len = FIELD_OFFSET(SID, SubAuthority[group->SubAuthorityCount]);
 329     sd->sacl_len = 0;
 330     sd->dacl_len = dacl_size;
 331
 332     ptr = (char *)(sd + 1);
 333     memcpy( ptr, user, sd->owner_len );
 334     ptr += sd->owner_len;
 335     memcpy( ptr, group, sd->group_len );
 336     ptr += sd->group_len;
 337
 338     dacl = (ACL *)ptr;
 339     dacl->AclRevision = ACL_REVISION;
 340     dacl->Sbz1 = 0;
 341     dacl->AclSize = dacl_size;
 342     dacl->AceCount = 1 + (mode & S_IRWXU ? 1 : 0) + (mode & S_IRWXO ? 1 : 0);
 343     if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) ||
 344         (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) ||
 345         (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH))))
 346         dacl->AceCount++;
 347     dacl->Sbz2 = 0;
 348
 349     /* always give FILE_ALL_ACCESS for Local System */
 350     aaa = (ACCESS_ALLOWED_ACE *)(dacl + 1);
 351     current_ace = &aaa->Header;
 352     aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 353     aaa->Header.AceFlags = 0;
 354     aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 355         FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]);
 356     aaa->Mask = FILE_ALL_ACCESS;
 357     sid = (SID *)&aaa->SidStart;
 358     memcpy( sid, local_system_sid, FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]) );
 359
 360     if (mode & S_IRWXU)
 361     {
 362         /* appropriate access rights for the user */
 363         aaa = (ACCESS_ALLOWED_ACE *)ace_next( current_ace );
 364         current_ace = &aaa->Header;
 365         aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 366         aaa->Header.AceFlags = 0;
 367         aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 368                               FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 369         aaa->Mask = WRITE_DAC | WRITE_OWNER;
 370         if (mode & S_IRUSR)
 371             aaa->Mask |= FILE_GENERIC_READ;
 372         if (mode & S_IWUSR)
 373             aaa->Mask |= FILE_GENERIC_WRITE | DELETE;
 374         if (mode & S_IXUSR)
 375             aaa->Mask |= FILE_GENERIC_EXECUTE;
 376         sid = (SID *)&aaa->SidStart;
 377         memcpy( sid, user, FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) );
 378     }
 379     if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) ||
 380         (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) ||
 381         (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH))))
 382     {
 383         /* deny just in case the user is a member of the group */
 384         ACCESS_DENIED_ACE *ada = (ACCESS_DENIED_ACE *)ace_next( current_ace );
 385         current_ace = &ada->Header;
 386         ada->Header.AceType = ACCESS_DENIED_ACE_TYPE;
 387         ada->Header.AceFlags = 0;
 388         ada->Header.AceSize = FIELD_OFFSET(ACCESS_DENIED_ACE, SidStart) +
 389                               FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 390         ada->Mask = 0;
 391         if (!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH)))
 392             ada->Mask |= FILE_GENERIC_READ;
 393         if (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IROTH)))
 394             ada->Mask |= FILE_GENERIC_WRITE | DELETE;
 395         if (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH)))
 396             ada->Mask |= FILE_GENERIC_EXECUTE;
 397         ada->Mask &= ~STANDARD_RIGHTS_ALL; /* never deny standard rights */
 398         sid = (SID *)&ada->SidStart;
 399         memcpy( sid, user, FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) );
 400     }
 401     if (mode & S_IRWXO)
 402     {
 403         /* appropriate access rights for Everyone */
 404         aaa = (ACCESS_ALLOWED_ACE *)ace_next( current_ace );
 405         current_ace = &aaa->Header;
 406         aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 407         aaa->Header.AceFlags = 0;
 408         aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 409                              FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]);
 410         aaa->Mask = 0;
 411         if (mode & S_IROTH)
 412             aaa->Mask |= FILE_GENERIC_READ;
 413         if (mode & S_IWOTH)
 414             aaa->Mask |= FILE_GENERIC_WRITE | DELETE;
 415         if (mode & S_IXOTH)
 416             aaa->Mask |= FILE_GENERIC_EXECUTE;
 417         sid = (SID *)&aaa->SidStart;
 418         memcpy( sid, world_sid, FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]) );
 419     }
 420
 421     return sd;
 422 }
 423
 424 static struct security_descriptor *file_get_sd( struct object *obj )
 425 {
 426     struct file *file = (struct file *)obj;
 427     struct stat st;
 428     int unix_fd;
 429     struct security_descriptor *sd;
 430
 431     assert( obj->ops == &file_ops );
 432
 433     unix_fd = get_file_unix_fd( file );
 434
 435     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
 436         return obj->sd;
 437
 438     /* mode and uid the same? if so, no need to re-generate security descriptor */
 439     if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (file->mode & (S_IRWXU|S_IRWXO)) &&
 440         (st.st_uid == file->uid))
 441         return obj->sd;
 442
 443     sd = mode_to_sd( st.st_mode,
 444                      security_unix_uid_to_sid( st.st_uid ),
 445                      token_get_primary_group( current->process->token ));
 446     if (!sd) return obj->sd;
 447
 448     file->mode = st.st_mode;
 449     file->uid = st.st_uid;
 450     free( obj->sd );
 451     obj->sd = sd;
 452     return sd;
 453 }
 454
 455 mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner )
 456 {
 457     mode_t new_mode = 0;
 458     mode_t denied_mode = 0;
 459     int present;
 460     const ACL *dacl = sd_get_dacl( sd, &present );
 461     if (present && dacl)
 462     {
 463         const ACE_HEADER *ace = (const ACE_HEADER *)(dacl + 1);
 464         ULONG i;
 465         for (i = 0; i < dacl->AceCount; i++, ace = ace_next( ace ))
 466         {
 467             const ACCESS_ALLOWED_ACE *aa_ace;
 468             const ACCESS_DENIED_ACE *ad_ace;
 469             const SID *sid;
 470
 471             if (ace->AceFlags & INHERIT_ONLY_ACE) continue;
 472
 473             switch (ace->AceType)
 474             {
 475                 case ACCESS_DENIED_ACE_TYPE:
 476                     ad_ace = (const ACCESS_DENIED_ACE *)ace;
 477                     sid = (const SID *)&ad_ace->SidStart;
 478                     if (security_equal_sid( sid, security_world_sid ))
 479                     {
 480                         unsigned int access = generic_file_map_access( ad_ace->Mask );
 481                         if (access & FILE_READ_DATA)
 482                             denied_mode |= S_IRUSR|S_IRGRP|S_IROTH;
 483                         if (access & FILE_WRITE_DATA)
 484                             denied_mode |= S_IWUSR|S_IWGRP|S_IWOTH;
 485                         if (access & FILE_EXECUTE)
 486                             denied_mode |= S_IXUSR|S_IXGRP|S_IXOTH;
 487                     }
 488                     else if (security_equal_sid( sid, owner ))
 489                     {
 490                         unsigned int access = generic_file_map_access( ad_ace->Mask );
 491                         if (access & FILE_READ_DATA)
 492                             denied_mode |= S_IRUSR;
 493                         if (access & FILE_WRITE_DATA)
 494                             denied_mode |= S_IWUSR;
 495                         if (access & FILE_EXECUTE)
 496                             denied_mode |= S_IXUSR;
 497                     }
 498                     break;
 499                 case ACCESS_ALLOWED_ACE_TYPE:
 500                     aa_ace = (const ACCESS_ALLOWED_ACE *)ace;
 501                     sid = (const SID *)&aa_ace->SidStart;
 502                     if (security_equal_sid( sid, security_world_sid ))
 503                     {
 504                         unsigned int access = generic_file_map_access( aa_ace->Mask );
 505                         if (access & FILE_READ_DATA)
 506                             new_mode |= S_IRUSR|S_IRGRP|S_IROTH;
 507                         if (access & FILE_WRITE_DATA)
 508                             new_mode |= S_IWUSR|S_IWGRP|S_IWOTH;
 509                         if (access & FILE_EXECUTE)
 510                             new_mode |= S_IXUSR|S_IXGRP|S_IXOTH;
 511                     }
 512                     else if (security_equal_sid( sid, owner ))
 513                     {
 514                         unsigned int access = generic_file_map_access( aa_ace->Mask );
 515                         if (access & FILE_READ_DATA)
 516                             new_mode |= S_IRUSR;
 517                         if (access & FILE_WRITE_DATA)
 518                             new_mode |= S_IWUSR;
 519                         if (access & FILE_EXECUTE)
 520                             new_mode |= S_IXUSR;
 521                     }
 522                     break;
 523             }
 524         }
 525     }
 526     else
 527         /* no ACL means full access rights to anyone */
 528         new_mode = S_IRWXU | S_IRWXO;
 529
 530     return new_mode & ~denied_mode;
 531 }
 532
 533 static int file_set_sd( struct object *obj, const struct security_descriptor *sd,
 534                         unsigned int set_info )
 535 {
 536     struct file *file = (struct file *)obj;
 537     const SID *owner;
 538     struct stat st;
 539     mode_t mode;
 540     int unix_fd;
 541
 542     assert( obj->ops == &file_ops );
 543
 544     unix_fd = get_file_unix_fd( file );
 545
 546     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
 547
 548     if (set_info & OWNER_SECURITY_INFORMATION)
 549     {
 550         owner = sd_get_owner( sd );
 551         if (!owner)
 552         {
 553             set_error( STATUS_INVALID_SECURITY_DESCR );
 554             return 0;
 555         }
 556         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 557         {
 558             /* FIXME: get Unix uid and call fchown */
 559         }
 560     }
 561     else if (obj->sd)
 562         owner = sd_get_owner( obj->sd );
 563     else
 564         owner = token_get_user( current->process->token );
 565
 566     /* group and sacl not supported */
 567
 568     if (set_info & DACL_SECURITY_INFORMATION)
 569     {
 570         /* keep the bits that we don't map to access rights in the ACL */
 571         mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG);
 572         mode |= sd_to_mode( sd, owner );
 573
 574         if (st.st_mode != mode && fchmod( unix_fd, mode ) == -1)
 575         {
 576             file_set_error();
 577             return 0;
 578         }
 579     }
 580     return 1;
 581 }
 582
 583 static void file_destroy( struct object *obj )
 584 {
 585     struct file *file = (struct file *)obj;
 586     assert( obj->ops == &file_ops );
 587
 588     if (file->fd) release_object( file->fd );
 589 }
 590
 591 /* set the last error depending on errno */
 592 void file_set_error(void)
 593 {
 594     switch (errno)
 595     {
 596     case ETXTBSY:
 597     case EAGAIN:    set_error( STATUS_SHARING_VIOLATION ); break;
 598     case EBADF:     set_error( STATUS_INVALID_HANDLE ); break;
 599     case ENOSPC:    set_error( STATUS_DISK_FULL ); break;
 600     case EACCES:
 601     case ESRCH:
 602     case EROFS:
 603     case EPERM:     set_error( STATUS_ACCESS_DENIED ); break;
 604     case EBUSY:     set_error( STATUS_FILE_LOCK_CONFLICT ); break;
 605     case ENOENT:    set_error( STATUS_NO_SUCH_FILE ); break;
 606     case EISDIR:    set_error( STATUS_FILE_IS_A_DIRECTORY ); break;
 607     case ENFILE:
 608     case EMFILE:    set_error( STATUS_TOO_MANY_OPENED_FILES ); break;
 609     case EEXIST:    set_error( STATUS_OBJECT_NAME_COLLISION ); break;
 610     case EINVAL:    set_error( STATUS_INVALID_PARAMETER ); break;
 611     case ESPIPE:    set_error( STATUS_ILLEGAL_FUNCTION ); break;
 612     case ENOTEMPTY: set_error( STATUS_DIRECTORY_NOT_EMPTY ); break;
 613     case EIO:       set_error( STATUS_ACCESS_VIOLATION ); break;
 614     case ENOTDIR:   set_error( STATUS_NOT_A_DIRECTORY ); break;
 615     case EFBIG:     set_error( STATUS_SECTION_TOO_BIG ); break;
 616     case ENODEV:    set_error( STATUS_NO_SUCH_DEVICE ); break;
 617     case ENXIO:     set_error( STATUS_NO_SUCH_DEVICE ); break;
 618 #ifdef EOVERFLOW
 619     case EOVERFLOW: set_error( STATUS_INVALID_PARAMETER ); break;
 620 #endif
 621     default:
 622         perror("wineserver: file_set_error() can't map error");
 623         set_error( STATUS_UNSUCCESSFUL );
 624         break;
 625     }
 626 }
 627
 628 struct file *get_file_obj( struct process *process, obj_handle_t handle, unsigned int access )
 629 {
 630     return (struct file *)get_handle_obj( process, handle, access, &file_ops );
 631 }
 632
 633 int get_file_unix_fd( struct file *file )
 634 {
 635     return get_unix_fd( file->fd );
 636 }
 637
 638 struct file *grab_file_unless_removable( struct file *file )
 639 {
 640     if (is_fd_removable( file->fd )) return NULL;
 641     return (struct file *)grab_object( file );
 642 }
 643
 644 /* extend a file beyond the current end of file */
 645 static int extend_file( struct file *file, file_pos_t new_size )
 646 {
 647     static const char zero;
 648     int unix_fd = get_file_unix_fd( file );
 649     off_t size = new_size;
 650
 651     if (unix_fd == -1) return 0;
 652
 653     if (sizeof(new_size) > sizeof(size) && size != new_size)
 654     {
 655         set_error( STATUS_INVALID_PARAMETER );
 656         return 0;
 657     }
 658     /* extend the file one byte beyond the requested size and then truncate it */
 659     /* this should work around ftruncate implementations that can't extend files */
 660     if (pwrite( unix_fd, &zero, 1, size ) != -1)
 661     {
 662         ftruncate( unix_fd, size );
 663         return 1;
 664     }
 665     file_set_error();
 666     return 0;
 667 }
 668
 669 /* try to grow the file to the specified size */
 670 int grow_file( struct file *file, file_pos_t size )
 671 {
 672     struct stat st;
 673     int unix_fd = get_file_unix_fd( file );
 674
 675     if (unix_fd == -1) return 0;
 676
 677     if (fstat( unix_fd, &st ) == -1)
 678     {
 679         file_set_error();
 680         return 0;
 681     }
 682     if (st.st_size >= size) return 1;  /* already large enough */
 683     return extend_file( file, size );
 684 }
 685
 686 /* create a file */
 687 DECL_HANDLER(create_file)
 688 {
 689     struct object *file;
 690     const struct object_attributes *objattr = get_req_data();
 691     const struct security_descriptor *sd;
 692     const char *name;
 693     data_size_t name_len;
 694
 695     reply->handle = 0;
 696
 697     if (!objattr_is_valid( objattr, get_req_data_size() ))
 698         return;
 699     /* name is transferred in the unix codepage outside of the objattr structure */
 700     if (objattr->name_len)
 701     {
 702         set_error( STATUS_INVALID_PARAMETER );
 703         return;
 704     }
 705
 706     sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
 707
 708     name = (const char *)get_req_data() + sizeof(*objattr) + objattr->sd_len;
 709     name_len = get_req_data_size() - sizeof(*objattr) - objattr->sd_len;
 710
 711     reply->handle = 0;
 712     if ((file = create_file( name, name_len, req->access,
 713                              req->sharing, req->create, req->options,
 714                              req->attrs, sd )))
 715     {
 716         reply->handle = alloc_handle( current->process, file, req->access, req->attributes );
 717         release_object( file );
 718     }
 719 }
 720
 721 /* allocate a file handle for a Unix fd */
 722 DECL_HANDLER(alloc_file_handle)
 723 {
 724     struct file *file;
 725     int fd;
 726
 727     reply->handle = 0;
 728     if ((fd = thread_get_inflight_fd( current, req->fd )) == -1)
 729     {
 730         set_error( STATUS_INVALID_HANDLE );
 731         return;
 732     }
 733     if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE )))
 734     {
 735         reply->handle = alloc_handle( current->process, file, req->access, req->attributes );
 736         release_object( file );
 737     }
 738 }
 739
 740 /* lock a region of a file */
 741 DECL_HANDLER(lock_file)
 742 {
 743     struct file *file;
 744
 745     if ((file = get_file_obj( current->process, req->handle, 0 )))
 746     {
 747         reply->handle = lock_fd( file->fd, req->offset, req->count, req->shared, req->wait );
 748         reply->overlapped = is_overlapped( file );
 749         release_object( file );
 750     }
 751 }
 752
 753 /* unlock a region of a file */
 754 DECL_HANDLER(unlock_file)
 755 {
 756     struct file *file;
 757
 758     if ((file = get_file_obj( current->process, req->handle, 0 )))
 759     {
 760         unlock_fd( file->fd, req->offset, req->count );
 761         release_object( file );
 762     }
 763 }