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 static mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner );
  79
  80 static const struct object_ops file_ops =
  81 {
  82     sizeof(struct file),          /* size */
  83     file_dump,                    /* dump */
  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->fd      = fd;
 151     grab_object( fd );
 152     set_fd_user( fd, &file_fd_ops, &file->obj );
 153     return &file->obj;
 154 }
 155
 156 static struct object *create_file( const char *nameptr, data_size_t len, unsigned int access,
 157                                    unsigned int sharing, int create, unsigned int options,
 158                                    unsigned int attrs, const struct security_descriptor *sd )
 159 {
 160     struct object *obj = NULL;
 161     struct fd *fd;
 162     int flags;
 163     char *name;
 164     mode_t mode;
 165
 166     if (!(name = mem_alloc( len + 1 ))) return NULL;
 167     memcpy( name, nameptr, len );
 168     name[len] = 0;
 169
 170     switch(create)
 171     {
 172     case FILE_CREATE:       flags = O_CREAT | O_EXCL; break;
 173     case FILE_OVERWRITE_IF: /* FIXME: the difference is whether we trash existing attr or not */
 174     case FILE_SUPERSEDE:    flags = O_CREAT | O_TRUNC; break;
 175     case FILE_OPEN:         flags = 0; break;
 176     case FILE_OPEN_IF:      flags = O_CREAT; break;
 177     case FILE_OVERWRITE:    flags = O_TRUNC; break;
 178     default:                set_error( STATUS_INVALID_PARAMETER ); goto done;
 179     }
 180
 181     if (sd)
 182     {
 183         const SID *owner = sd_get_owner( sd );
 184         if (!owner)
 185             owner = token_get_user( current->process->token );
 186         mode = sd_to_mode( sd, owner );
 187     }
 188     else
 189         mode = (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666;
 190
 191     if (len >= 4 &&
 192         (!strcasecmp( name + len - 4, ".exe" ) || !strcasecmp( name + len - 4, ".com" )))
 193     {
 194         if (mode & S_IRUSR)
 195             mode |= S_IXUSR;
 196         if (mode & S_IRGRP)
 197             mode |= S_IXGRP;
 198         if (mode & S_IROTH)
 199             mode |= S_IXOTH;
 200     }
 201
 202     access = generic_file_map_access( access );
 203
 204     /* FIXME: should set error to STATUS_OBJECT_NAME_COLLISION if file existed before */
 205     fd = open_fd( name, flags | O_NONBLOCK | O_LARGEFILE, &mode, access, sharing, options );
 206     if (!fd) goto done;
 207
 208     if (S_ISDIR(mode))
 209         obj = create_dir_obj( fd );
 210     else if (S_ISCHR(mode) && is_serial_fd( fd ))
 211         obj = create_serial( fd );
 212     else
 213         obj = create_file_obj( fd, access, mode );
 214
 215     release_object( fd );
 216
 217 done:
 218     free( name );
 219     return obj;
 220 }
 221
 222 /* check if two file objects point to the same file */
 223 int is_same_file( struct file *file1, struct file *file2 )
 224 {
 225     return is_same_file_fd( file1->fd, file2->fd );
 226 }
 227
 228 /* create a temp file for anonymous mappings */
 229 struct file *create_temp_file( int access )
 230 {
 231     char tmpfn[16];
 232     int fd;
 233
 234     sprintf( tmpfn, "anonmap.XXXXXX" );  /* create it in the server directory */
 235     fd = mkstemps( tmpfn, 0 );
 236     if (fd == -1)
 237     {
 238         file_set_error();
 239         return NULL;
 240     }
 241     unlink( tmpfn );
 242     return create_file_for_fd( fd, access, 0 );
 243 }
 244
 245 static void file_dump( struct object *obj, int verbose )
 246 {
 247     struct file *file = (struct file *)obj;
 248     assert( obj->ops == &file_ops );
 249     fprintf( stderr, "File fd=%p\n", file->fd );
 250 }
 251
 252 static int file_get_poll_events( struct fd *fd )
 253 {
 254     struct file *file = get_fd_user( fd );
 255     int events = 0;
 256     assert( file->obj.ops == &file_ops );
 257     if (file->access & FILE_UNIX_READ_ACCESS) events |= POLLIN;
 258     if (file->access & FILE_UNIX_WRITE_ACCESS) events |= POLLOUT;
 259     return events;
 260 }
 261
 262 static void file_flush( struct fd *fd, struct event **event )
 263 {
 264     int unix_fd = get_unix_fd( fd );
 265     if (unix_fd != -1 && fsync( unix_fd ) == -1) file_set_error();
 266 }
 267
 268 static enum server_fd_type file_get_fd_type( struct fd *fd )
 269 {
 270     struct file *file = get_fd_user( fd );
 271
 272     if (S_ISREG(file->mode) || S_ISBLK(file->mode)) return FD_TYPE_FILE;
 273     if (S_ISDIR(file->mode)) return FD_TYPE_DIR;
 274     return FD_TYPE_CHAR;
 275 }
 276
 277 static struct fd *file_get_fd( struct object *obj )
 278 {
 279     struct file *file = (struct file *)obj;
 280     assert( obj->ops == &file_ops );
 281     return (struct fd *)grab_object( file->fd );
 282 }
 283
 284 static unsigned int generic_file_map_access( unsigned int access )
 285 {
 286     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 287     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 288     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 289     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 290     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 291 }
 292
 293 static struct security_descriptor *file_get_sd( struct object *obj )
 294 {
 295     struct file *file = (struct file *)obj;
 296     struct stat st;
 297     int unix_fd;
 298     struct security_descriptor *sd;
 299     const SID *user;
 300     const SID *group;
 301     size_t dacl_size;
 302     ACCESS_ALLOWED_ACE *aaa;
 303     ACL *dacl;
 304     SID *sid;
 305     char *ptr;
 306     const SID *world_sid = security_world_sid;
 307     const SID *local_system_sid = security_local_system_sid;
 308
 309     assert( obj->ops == &file_ops );
 310
 311     unix_fd = get_file_unix_fd( file );
 312
 313     if (unix_fd == -1) return obj->sd;
 314
 315     if (fstat( unix_fd, &st ) == -1)
 316         return obj->sd;
 317
 318     /* mode and uid the same? if so, no need to re-generate security descriptor */
 319     if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (file->mode & (S_IRWXU|S_IRWXO)) &&
 320         (st.st_uid == file->uid))
 321         return obj->sd;
 322
 323     user = security_unix_uid_to_sid( st.st_uid );
 324     group = token_get_primary_group( current->process->token );
 325
 326     dacl_size = sizeof(ACL) + FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 327         FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]);
 328     if (st.st_mode & S_IRWXU)
 329         dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 330             FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 331     if (st.st_mode & S_IRWXO)
 332         dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 333             FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]);
 334
 335     sd = mem_alloc( sizeof(struct security_descriptor) +
 336                     FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) +
 337                     FIELD_OFFSET(SID, SubAuthority[group->SubAuthorityCount]) +
 338                     dacl_size );
 339     if (!sd) return obj->sd;
 340
 341     sd->control = SE_DACL_PRESENT;
 342     sd->owner_len = FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 343     sd->group_len = FIELD_OFFSET(SID, SubAuthority[group->SubAuthorityCount]);
 344     sd->sacl_len = 0;
 345     sd->dacl_len = dacl_size;
 346
 347     ptr = (char *)(sd + 1);
 348     memcpy( ptr, user, sd->owner_len );
 349     ptr += sd->owner_len;
 350     memcpy( ptr, group, sd->group_len );
 351     ptr += sd->group_len;
 352
 353     dacl = (ACL *)ptr;
 354     dacl->AclRevision = ACL_REVISION;
 355     dacl->Sbz1 = 0;
 356     dacl->AclSize = dacl_size;
 357     dacl->AceCount = 1 + (st.st_mode & S_IRWXU ? 1 : 0) + (st.st_mode & S_IRWXO ? 1 : 0);
 358     dacl->Sbz2 = 0;
 359
 360     /* always give FILE_ALL_ACCESS for Local System */
 361     aaa = (ACCESS_ALLOWED_ACE *)(dacl + 1);
 362     aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 363     aaa->Header.AceFlags = 0;
 364     aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 365         FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]);
 366     aaa->Mask = FILE_ALL_ACCESS;
 367     sid = (SID *)&aaa->SidStart;
 368     memcpy( sid, local_system_sid, FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]) );
 369
 370     if (st.st_mode & S_IRWXU)
 371     {
 372         /* appropriate access rights for the user */
 373         aaa = (ACCESS_ALLOWED_ACE *)ace_next( &aaa->Header );
 374         aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 375         aaa->Header.AceFlags = 0;
 376         aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 377                               FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]);
 378         aaa->Mask = WRITE_DAC | WRITE_OWNER;
 379         if (st.st_mode & S_IRUSR)
 380             aaa->Mask |= FILE_GENERIC_READ;
 381         if (st.st_mode & S_IWUSR)
 382             aaa->Mask |= FILE_GENERIC_WRITE | DELETE;
 383         if (st.st_mode & S_IXUSR)
 384             aaa->Mask |= FILE_GENERIC_EXECUTE;
 385         sid = (SID *)&aaa->SidStart;
 386         memcpy( sid, user, FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) );
 387     }
 388     if (st.st_mode & S_IRWXO)
 389     {
 390         /* appropriate access rights for Everyone */
 391         aaa = (ACCESS_ALLOWED_ACE *)ace_next( &aaa->Header );
 392         aaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
 393         aaa->Header.AceFlags = 0;
 394         aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) +
 395                              FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]);
 396         aaa->Mask = 0;
 397         if (st.st_mode & S_IROTH)
 398             aaa->Mask |= FILE_GENERIC_READ;
 399         if (st.st_mode & S_IWOTH)
 400             aaa->Mask |= FILE_GENERIC_WRITE | DELETE;
 401         if (st.st_mode & S_IXOTH)
 402             aaa->Mask |= FILE_GENERIC_EXECUTE;
 403         sid = (SID *)&aaa->SidStart;
 404         memcpy( sid, world_sid, FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]) );
 405     }
 406
 407     file->mode = st.st_mode;
 408     file->uid = st.st_uid;
 409     free( obj->sd );
 410     obj->sd = sd;
 411     return sd;
 412 }
 413
 414 static mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner )
 415 {
 416     mode_t new_mode = 0;
 417     mode_t denied_mode = 0;
 418     int present;
 419     const ACL *dacl = sd_get_dacl( sd, &present );
 420     if (present && dacl)
 421     {
 422         const ACE_HEADER *ace = (const ACE_HEADER *)(dacl + 1);
 423         ULONG i;
 424         for (i = 0; i < dacl->AceCount; i++, ace_next( ace ))
 425         {
 426             const ACCESS_ALLOWED_ACE *aa_ace;
 427             const ACCESS_DENIED_ACE *ad_ace;
 428             const SID *sid;
 429
 430             if (ace->AceFlags & INHERIT_ONLY_ACE) continue;
 431
 432             switch (ace->AceType)
 433             {
 434                 case ACCESS_DENIED_ACE_TYPE:
 435                     ad_ace = (const ACCESS_DENIED_ACE *)ace;
 436                     sid = (const SID *)&ad_ace->SidStart;
 437                     if (security_equal_sid( sid, security_world_sid ))
 438                     {
 439                         unsigned int access = generic_file_map_access( ad_ace->Mask );
 440                         if (access & FILE_READ_DATA)
 441                             denied_mode |= S_IROTH;
 442                         if (access & FILE_WRITE_DATA)
 443                             denied_mode |= S_IWOTH;
 444                         if (access & FILE_EXECUTE)
 445                             denied_mode |= S_IXOTH;
 446                     }
 447                     else if (security_equal_sid( sid, owner ))
 448                     {
 449                         unsigned int access = generic_file_map_access( ad_ace->Mask );
 450                         if (access & FILE_READ_DATA)
 451                             denied_mode |= S_IRUSR;
 452                         if (access & FILE_WRITE_DATA)
 453                             denied_mode |= S_IWUSR;
 454                         if (access & FILE_EXECUTE)
 455                             denied_mode |= S_IXUSR;
 456                     }
 457                     break;
 458                 case ACCESS_ALLOWED_ACE_TYPE:
 459                     aa_ace = (const ACCESS_ALLOWED_ACE *)ace;
 460                     sid = (const SID *)&aa_ace->SidStart;
 461                     if (security_equal_sid( sid, security_world_sid ))
 462                     {
 463                         unsigned int access = generic_file_map_access( aa_ace->Mask );
 464                         if (access & FILE_READ_DATA)
 465                             new_mode |= S_IROTH;
 466                         if (access & FILE_WRITE_DATA)
 467                             new_mode |= S_IWOTH;
 468                         if (access & FILE_EXECUTE)
 469                             new_mode |= S_IXOTH;
 470                     }
 471                     else if (security_equal_sid( sid, owner ))
 472                     {
 473                         unsigned int access = generic_file_map_access( aa_ace->Mask );
 474                         if (access & FILE_READ_DATA)
 475                             new_mode |= S_IRUSR;
 476                         if (access & FILE_WRITE_DATA)
 477                             new_mode |= S_IWUSR;
 478                         if (access & FILE_EXECUTE)
 479                             new_mode |= S_IXUSR;
 480                     }
 481                     break;
 482             }
 483         }
 484     }
 485     else
 486         /* no ACL means full access rights to anyone */
 487         new_mode = S_IRWXU | S_IRWXO;
 488
 489     return new_mode & ~denied_mode;
 490 }
 491
 492 static int file_set_sd( struct object *obj, const struct security_descriptor *sd,
 493                         unsigned int set_info )
 494 {
 495     struct file *file = (struct file *)obj;
 496     const SID *owner;
 497     mode_t mode;
 498     int unix_fd;
 499
 500     assert( obj->ops == &file_ops );
 501
 502     unix_fd = get_file_unix_fd( file );
 503
 504     if (unix_fd == -1) return 1;
 505
 506     if (set_info & OWNER_SECURITY_INFORMATION)
 507     {
 508         owner = sd_get_owner( sd );
 509         if (!owner)
 510         {
 511             set_error( STATUS_INVALID_SECURITY_DESCR );
 512             return 0;
 513         }
 514         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 515         {
 516             /* FIXME: get Unix uid and call fchown */
 517         }
 518     }
 519     else if (obj->sd)
 520         owner = sd_get_owner( obj->sd );
 521     else
 522         owner = token_get_user( current->process->token );
 523
 524     /* group and sacl not supported */
 525
 526     if (set_info & DACL_SECURITY_INFORMATION)
 527     {
 528         /* keep the bits that we don't map to access rights in the ACL */
 529         mode = file->mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG);
 530         mode |= sd_to_mode( sd, owner );
 531
 532         if (file->mode != mode)
 533         {
 534             if (fchmod( unix_fd, mode ) == -1)
 535             {
 536                 file_set_error();
 537                 return 0;
 538             }
 539
 540             file->mode = mode;
 541         }
 542     }
 543     return 1;
 544 }
 545
 546 static void file_destroy( struct object *obj )
 547 {
 548     struct file *file = (struct file *)obj;
 549     assert( obj->ops == &file_ops );
 550
 551     if (file->fd) release_object( file->fd );
 552 }
 553
 554 /* set the last error depending on errno */
 555 void file_set_error(void)
 556 {
 557     switch (errno)
 558     {
 559     case ETXTBSY:
 560     case EAGAIN:    set_error( STATUS_SHARING_VIOLATION ); break;
 561     case EBADF:     set_error( STATUS_INVALID_HANDLE ); break;
 562     case ENOSPC:    set_error( STATUS_DISK_FULL ); break;
 563     case EACCES:
 564     case ESRCH:
 565     case EPERM:     set_error( STATUS_ACCESS_DENIED ); break;
 566     case EROFS:     set_error( STATUS_MEDIA_WRITE_PROTECTED ); break;
 567     case EBUSY:     set_error( STATUS_FILE_LOCK_CONFLICT ); break;
 568     case ENOENT:    set_error( STATUS_NO_SUCH_FILE ); break;
 569     case EISDIR:    set_error( STATUS_FILE_IS_A_DIRECTORY ); break;
 570     case ENFILE:
 571     case EMFILE:    set_error( STATUS_TOO_MANY_OPENED_FILES ); break;
 572     case EEXIST:    set_error( STATUS_OBJECT_NAME_COLLISION ); break;
 573     case EINVAL:    set_error( STATUS_INVALID_PARAMETER ); break;
 574     case ESPIPE:    set_error( STATUS_ILLEGAL_FUNCTION ); break;
 575     case ENOTEMPTY: set_error( STATUS_DIRECTORY_NOT_EMPTY ); break;
 576     case EIO:       set_error( STATUS_ACCESS_VIOLATION ); break;
 577     case ENOTDIR:   set_error( STATUS_NOT_A_DIRECTORY ); break;
 578     case EFBIG:     set_error( STATUS_SECTION_TOO_BIG ); break;
 579     case ENODEV:    set_error( STATUS_NO_SUCH_DEVICE ); break;
 580     case ENXIO:     set_error( STATUS_NO_SUCH_DEVICE ); break;
 581 #ifdef EOVERFLOW
 582     case EOVERFLOW: set_error( STATUS_INVALID_PARAMETER ); break;
 583 #endif
 584     default:
 585         perror("wineserver: file_set_error() can't map error");
 586         set_error( STATUS_UNSUCCESSFUL );
 587         break;
 588     }
 589 }
 590
 591 struct file *get_file_obj( struct process *process, obj_handle_t handle, unsigned int access )
 592 {
 593     return (struct file *)get_handle_obj( process, handle, access, &file_ops );
 594 }
 595
 596 int get_file_unix_fd( struct file *file )
 597 {
 598     return get_unix_fd( file->fd );
 599 }
 600
 601 struct file *grab_file_unless_removable( struct file *file )
 602 {
 603     if (is_fd_removable( file->fd )) return NULL;
 604     return (struct file *)grab_object( file );
 605 }
 606
 607 /* extend a file beyond the current end of file */
 608 static int extend_file( struct file *file, file_pos_t new_size )
 609 {
 610     static const char zero;
 611     int unix_fd = get_file_unix_fd( file );
 612     off_t size = new_size;
 613
 614     if (unix_fd == -1) return 0;
 615
 616     if (sizeof(new_size) > sizeof(size) && size != new_size)
 617     {
 618         set_error( STATUS_INVALID_PARAMETER );
 619         return 0;
 620     }
 621     /* extend the file one byte beyond the requested size and then truncate it */
 622     /* this should work around ftruncate implementations that can't extend files */
 623     if (pwrite( unix_fd, &zero, 1, size ) != -1)
 624     {
 625         ftruncate( unix_fd, size );
 626         return 1;
 627     }
 628     file_set_error();
 629     return 0;
 630 }
 631
 632 /* try to grow the file to the specified size */
 633 int grow_file( struct file *file, file_pos_t size )
 634 {
 635     struct stat st;
 636     int unix_fd = get_file_unix_fd( file );
 637
 638     if (unix_fd == -1) return 0;
 639
 640     if (fstat( unix_fd, &st ) == -1)
 641     {
 642         file_set_error();
 643         return 0;
 644     }
 645     if (st.st_size >= size) return 1;  /* already large enough */
 646     return extend_file( file, size );
 647 }
 648
 649 /* create a file */
 650 DECL_HANDLER(create_file)
 651 {
 652     struct object *file;
 653     const struct object_attributes *objattr = get_req_data();
 654     const struct security_descriptor *sd;
 655     const char *name;
 656     data_size_t name_len;
 657
 658     reply->handle = 0;
 659
 660     if (!objattr_is_valid( objattr, get_req_data_size() ))
 661         return;
 662     /* name is transferred in the unix codepage outside of the objattr structure */
 663     if (objattr->name_len)
 664     {
 665         set_error( STATUS_INVALID_PARAMETER );
 666         return;
 667     }
 668
 669     sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
 670
 671     name = (const char *)get_req_data() + sizeof(*objattr) + objattr->sd_len;
 672     name_len = get_req_data_size() - sizeof(*objattr) - objattr->sd_len;
 673
 674     reply->handle = 0;
 675     if ((file = create_file( name, name_len, req->access,
 676                              req->sharing, req->create, req->options,
 677                              req->attrs, sd )))
 678     {
 679         reply->handle = alloc_handle( current->process, file, req->access, req->attributes );
 680         release_object( file );
 681     }
 682 }
 683
 684 /* allocate a file handle for a Unix fd */
 685 DECL_HANDLER(alloc_file_handle)
 686 {
 687     struct file *file;
 688     int fd;
 689
 690     reply->handle = 0;
 691     if ((fd = thread_get_inflight_fd( current, req->fd )) == -1)
 692     {
 693         set_error( STATUS_INVALID_HANDLE );
 694         return;
 695     }
 696     if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE )))
 697     {
 698         reply->handle = alloc_handle( current->process, file, req->access, req->attributes );
 699         release_object( file );
 700     }
 701 }
 702
 703 /* lock a region of a file */
 704 DECL_HANDLER(lock_file)
 705 {
 706     struct file *file;
 707
 708     if ((file = get_file_obj( current->process, req->handle, 0 )))
 709     {
 710         reply->handle = lock_fd( file->fd, req->offset, req->count, req->shared, req->wait );
 711         reply->overlapped = is_overlapped( file );
 712         release_object( file );
 713     }
 714 }
 715
 716 /* unlock a region of a file */
 717 DECL_HANDLER(unlock_file)
 718 {
 719     struct file *file;
 720
 721     if ((file = get_file_obj( current->process, req->handle, 0 )))
 722     {
 723         unlock_fd( file->fd, req->offset, req->count );
 724         release_object( file );
 725     }
 726 }