server/file.c

   1 /*
   2  * Server-side file management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <fcntl.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <stdlib.h>
  12 #include <errno.h>
  13 #include <sys/errno.h>
  14 #include <sys/stat.h>
  15 #include <sys/time.h>
  16 #include <sys/types.h>
  17 #include <time.h>
  18 #include <unistd.h>
  19 #include <utime.h>
  20
  21 #include "winerror.h"
  22 #include "winbase.h"
  23
  24 #include "handle.h"
  25 #include "thread.h"
  26 #include "request.h"
  27
  28 struct file
  29 {
  30     struct object       obj;        /* object header */
  31     struct select_user  select;     /* select user */
  32     struct file        *next;       /* next file in hashing list */
  33     char               *name;       /* file name */
  34     unsigned int        access;     /* file access (GENERIC_READ/WRITE) */
  35     unsigned int        flags;      /* flags (FILE_FLAG_*) */
  36     unsigned int        sharing;    /* file sharing mode */
  37 };
  38
  39 #define NAME_HASH_SIZE 37
  40
  41 static struct file *file_hash[NAME_HASH_SIZE];
  42
  43 static void file_dump( struct object *obj, int verbose );
  44 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry );
  45 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry );
  46 static int file_signaled( struct object *obj, struct thread *thread );
  47 static int file_get_read_fd( struct object *obj );
  48 static int file_get_write_fd( struct object *obj );
  49 static int file_flush( struct object *obj );
  50 static int file_get_info( struct object *obj, struct get_file_info_request *req );
  51 static void file_destroy( struct object *obj );
  52
  53 static const struct object_ops file_ops =
  54 {
  55     sizeof(struct file),
  56     file_dump,
  57     file_add_queue,
  58     file_remove_queue,
  59     file_signaled,
  60     no_satisfied,
  61     file_get_read_fd,
  62     file_get_write_fd,
  63     file_flush,
  64     file_get_info,
  65     file_destroy
  66 };
  67
  68
  69 static int get_name_hash( const char *name )
  70 {
  71     int hash = 0;
  72     while (*name) hash ^= *name++;
  73     return hash % NAME_HASH_SIZE;
  74 }
  75
  76 /* check if the desired access is possible without violating */
  77 /* the sharing mode of other opens of the same file */
  78 static int check_sharing( const char *name, int hash, unsigned int access,
  79                           unsigned int sharing )
  80 {
  81     struct file *file;
  82     unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
  83     unsigned int existing_access = 0;
  84
  85     for (file = file_hash[hash]; file; file = file->next)
  86     {
  87         if (strcmp( file->name, name )) continue;
  88         existing_sharing &= file->sharing;
  89         existing_access |= file->access;
  90     }
  91     if ((access & GENERIC_READ) && !(existing_sharing & FILE_SHARE_READ)) goto error;
  92     if ((access & GENERIC_WRITE) && !(existing_sharing & FILE_SHARE_WRITE)) goto error;
  93     if ((existing_access & GENERIC_READ) && !(sharing & FILE_SHARE_READ)) goto error;
  94     if ((existing_access & GENERIC_WRITE) && !(sharing & FILE_SHARE_WRITE)) goto error;
  95     return 1;
  96  error:
  97     set_error( ERROR_SHARING_VIOLATION );
  98     return 0;
  99 }
 100
 101 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing,
 102                                         unsigned int attrs )
 103 {
 104     struct file *file;
 105     if ((file = alloc_object( &file_ops )))
 106     {
 107         file->name           = NULL;
 108         file->next           = NULL;
 109         file->select.fd      = fd;
 110         file->select.func    = default_select_event;
 111         file->select.private = file;
 112         file->access         = access;
 113         file->flags          = attrs;
 114         file->sharing        = sharing;
 115         register_select_user( &file->select );
 116     }
 117     return file;
 118 }
 119
 120
 121 static struct file *create_file( const char *nameptr, size_t len, unsigned int access,
 122                                  unsigned int sharing, int create, unsigned int attrs )
 123 {
 124     struct file *file;
 125     int hash, flags;
 126     struct stat st;
 127     char *name;
 128     int fd = -1;
 129
 130     if (!(name = mem_alloc( len + 1 ))) return NULL;
 131     memcpy( name, nameptr, len );
 132     name[len] = 0;
 133
 134     /* check sharing mode */
 135     hash = get_name_hash( name );
 136     if (!check_sharing( name, hash, access, sharing )) goto error;
 137
 138     switch(create)
 139     {
 140     case CREATE_NEW:        flags = O_CREAT | O_EXCL; break;
 141     case CREATE_ALWAYS:     flags = O_CREAT | O_TRUNC; break;
 142     case OPEN_ALWAYS:       flags = O_CREAT; break;
 143     case TRUNCATE_EXISTING: flags = O_TRUNC; break;
 144     case OPEN_EXISTING:     flags = 0; break;
 145     default:                set_error( ERROR_INVALID_PARAMETER ); goto error;
 146     }
 147     switch(access & (GENERIC_READ | GENERIC_WRITE))
 148     {
 149     case 0: break;
 150     case GENERIC_READ:  flags |= O_RDONLY; break;
 151     case GENERIC_WRITE: flags |= O_WRONLY; break;
 152     case GENERIC_READ|GENERIC_WRITE: flags |= O_RDWR; break;
 153     }
 154
 155     /* FIXME: should set error to ERROR_ALREADY_EXISTS if file existed before */
 156     if ((fd = open( name, flags | O_NONBLOCK,
 157                     (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666 )) == -1)
 158         goto file_error;
 159     /* refuse to open a directory */
 160     if (fstat( fd, &st ) == -1) goto file_error;
 161     if (S_ISDIR(st.st_mode))
 162     {
 163         set_error( ERROR_ACCESS_DENIED );
 164         goto error;
 165     }
 166
 167     if (!(file = create_file_for_fd( fd, access, sharing, attrs ))) goto error;
 168     file->name = name;
 169     file->next = file_hash[hash];
 170     file_hash[hash] = file;
 171     return file;
 172
 173  file_error:
 174     file_set_error();
 175  error:
 176     if (fd != -1) close( fd );
 177     free( name );
 178     return NULL;
 179 }
 180
 181 /* Create an anonymous Unix file */
 182 int create_anonymous_file(void)
 183 {
 184     char *name;
 185     int fd;
 186
 187     do
 188     {
 189         if (!(name = tmpnam(NULL)))
 190         {
 191             set_error( ERROR_TOO_MANY_OPEN_FILES );
 192             return -1;
 193         }
 194         fd = open( name, O_CREAT | O_EXCL | O_RDWR, 0600 );
 195     } while ((fd == -1) && (errno == EEXIST));
 196     if (fd == -1)
 197     {
 198         file_set_error();
 199         return -1;
 200     }
 201     unlink( name );
 202     return fd;
 203 }
 204
 205 /* Create a temp file for anonymous mappings */
 206 struct file *create_temp_file( int access )
 207 {
 208     struct file *file;
 209     int fd;
 210
 211     if ((fd = create_anonymous_file()) == -1) return NULL;
 212     if (!(file = create_file_for_fd( fd, access, 0, 0 ))) close( fd );
 213     return file;
 214 }
 215
 216 static void file_dump( struct object *obj, int verbose )
 217 {
 218     struct file *file = (struct file *)obj;
 219     assert( obj->ops == &file_ops );
 220     fprintf( stderr, "File fd=%d flags=%08x name='%s'\n",
 221              file->select.fd, file->flags, file->name );
 222 }
 223
 224 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry )
 225 {
 226     struct file *file = (struct file *)obj;
 227     assert( obj->ops == &file_ops );
 228     if (!obj->head)  /* first on the queue */
 229     {
 230         int events = 0;
 231         if (file->access & GENERIC_READ) events |= READ_EVENT;
 232         if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 233         set_select_events( &file->select, events );
 234     }
 235     add_queue( obj, entry );
 236     return 1;
 237 }
 238
 239 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry )
 240 {
 241     struct file *file = (struct file *)grab_object(obj);
 242     assert( obj->ops == &file_ops );
 243
 244     remove_queue( obj, entry );
 245     if (!obj->head)  /* last on the queue is gone */
 246         set_select_events( &file->select, 0 );
 247     release_object( obj );
 248 }
 249
 250 static int file_signaled( struct object *obj, struct thread *thread )
 251 {
 252     int events = 0;
 253     struct file *file = (struct file *)obj;
 254     assert( obj->ops == &file_ops );
 255
 256     if (file->access & GENERIC_READ) events |= READ_EVENT;
 257     if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 258     if (check_select_events( &file->select, events ))
 259     {
 260         /* stop waiting on select() if we are signaled */
 261         set_select_events( &file->select, 0 );
 262         return 1;
 263     }
 264     else
 265     {
 266         /* restart waiting on select() if we are no longer signaled */
 267         if (obj->head) set_select_events( &file->select, events );
 268         return 0;
 269     }
 270 }
 271
 272 static int file_get_read_fd( struct object *obj )
 273 {
 274     struct file *file = (struct file *)obj;
 275     assert( obj->ops == &file_ops );
 276     return dup( file->select.fd );
 277 }
 278
 279 static int file_get_write_fd( struct object *obj )
 280 {
 281     struct file *file = (struct file *)obj;
 282     assert( obj->ops == &file_ops );
 283     return dup( file->select.fd );
 284 }
 285
 286 static int file_flush( struct object *obj )
 287 {
 288     int ret;
 289     struct file *file = (struct file *)grab_object(obj);
 290     assert( obj->ops == &file_ops );
 291
 292     ret = (fsync( file->select.fd ) != -1);
 293     if (!ret) file_set_error();
 294     release_object( file );
 295     return ret;
 296 }
 297
 298 static int file_get_info( struct object *obj, struct get_file_info_request *req )
 299 {
 300     struct stat st;
 301     struct file *file = (struct file *)obj;
 302     assert( obj->ops == &file_ops );
 303
 304     if (fstat( file->select.fd, &st ) == -1)
 305     {
 306         file_set_error();
 307         return 0;
 308     }
 309     if (S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) ||
 310         S_ISSOCK(st.st_mode) || isatty(file->select.fd)) req->type = FILE_TYPE_CHAR;
 311     else req->type = FILE_TYPE_DISK;
 312     if (S_ISDIR(st.st_mode)) req->attr = FILE_ATTRIBUTE_DIRECTORY;
 313     else req->attr = FILE_ATTRIBUTE_ARCHIVE;
 314     if (!(st.st_mode & S_IWUSR)) req->attr |= FILE_ATTRIBUTE_READONLY;
 315     req->access_time = st.st_atime;
 316     req->write_time  = st.st_mtime;
 317     req->size_high   = 0;
 318     req->size_low    = S_ISDIR(st.st_mode) ? 0 : st.st_size;
 319     req->links       = st.st_nlink;
 320     req->index_high  = st.st_dev;
 321     req->index_low   = st.st_ino;
 322     req->serial      = 0; /* FIXME */
 323     return 1;
 324 }
 325
 326 static void file_destroy( struct object *obj )
 327 {
 328     struct file *file = (struct file *)obj;
 329     assert( obj->ops == &file_ops );
 330
 331     if (file->name)
 332     {
 333         /* remove it from the hashing list */
 334         struct file **pptr = &file_hash[get_name_hash( file->name )];
 335         while (*pptr && *pptr != file) pptr = &(*pptr)->next;
 336         assert( *pptr );
 337         *pptr = (*pptr)->next;
 338         if (file->flags & FILE_FLAG_DELETE_ON_CLOSE) unlink( file->name );
 339         free( file->name );
 340     }
 341     unregister_select_user( &file->select );
 342     close( file->select.fd );
 343 }
 344
 345 /* set the last error depending on errno */
 346 void file_set_error(void)
 347 {
 348     switch (errno)
 349     {
 350     case EAGAIN:    set_error( ERROR_SHARING_VIOLATION ); break;
 351     case EBADF:     set_error( ERROR_INVALID_HANDLE ); break;
 352     case ENOSPC:    set_error( ERROR_HANDLE_DISK_FULL ); break;
 353     case EACCES:
 354     case EPERM:     set_error( ERROR_ACCESS_DENIED ); break;
 355     case EROFS:     set_error( ERROR_WRITE_PROTECT ); break;
 356     case EBUSY:     set_error( ERROR_LOCK_VIOLATION ); break;
 357     case ENOENT:    set_error( ERROR_FILE_NOT_FOUND ); break;
 358     case EISDIR:    set_error( ERROR_CANNOT_MAKE ); break;
 359     case ENFILE:
 360     case EMFILE:    set_error( ERROR_NO_MORE_FILES ); break;
 361     case EEXIST:    set_error( ERROR_FILE_EXISTS ); break;
 362     case EINVAL:    set_error( ERROR_INVALID_PARAMETER ); break;
 363     case ESPIPE:    set_error( ERROR_SEEK ); break;
 364     case ENOTEMPTY: set_error( ERROR_DIR_NOT_EMPTY ); break;
 365     default:        perror("file_set_error"); set_error( ERROR_UNKNOWN ); break;
 366     }
 367 }
 368
 369 struct file *get_file_obj( struct process *process, int handle,
 370                            unsigned int access )
 371 {
 372     return (struct file *)get_handle_obj( current->process, handle,
 373                                           access, &file_ops );
 374 }
 375
 376 int file_get_mmap_fd( struct file *file )
 377 {
 378     return dup( file->select.fd );
 379 }
 380
 381 static int set_file_pointer( int handle, int *low, int *high, int whence )
 382 {
 383     struct file *file;
 384     int result;
 385
 386     if (*high)
 387     {
 388         fprintf( stderr, "set_file_pointer: offset > 4Gb not supported yet\n" );
 389         set_error( ERROR_INVALID_PARAMETER );
 390         return 0;
 391     }
 392
 393     if (!(file = get_file_obj( current->process, handle, 0 )))
 394         return 0;
 395     if ((result = lseek( file->select.fd, *low, whence )) == -1)
 396     {
 397         /* Check for seek before start of file */
 398         if ((errno == EINVAL) && (whence != SEEK_SET) && (*low < 0))
 399             set_error( ERROR_NEGATIVE_SEEK );
 400         else
 401             file_set_error();
 402         release_object( file );
 403         return 0;
 404     }
 405     *low = result;
 406     release_object( file );
 407     return 1;
 408 }
 409
 410 static int truncate_file( int handle )
 411 {
 412     struct file *file;
 413     int result;
 414
 415     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 416         return 0;
 417     if (((result = lseek( file->select.fd, 0, SEEK_CUR )) == -1) ||
 418         (ftruncate( file->select.fd, result ) == -1))
 419     {
 420         file_set_error();
 421         release_object( file );
 422         return 0;
 423     }
 424     release_object( file );
 425     return 1;
 426
 427 }
 428
 429 /* try to grow the file to the specified size */
 430 int grow_file( struct file *file, int size_high, int size_low )
 431 {
 432     struct stat st;
 433
 434     if (size_high)
 435     {
 436         set_error( ERROR_INVALID_PARAMETER );
 437         return 0;
 438     }
 439     if (fstat( file->select.fd, &st ) == -1)
 440     {
 441         file_set_error();
 442         return 0;
 443     }
 444     if (st.st_size >= size_low) return 1;  /* already large enough */
 445     if (ftruncate( file->select.fd, size_low ) != -1) return 1;
 446     file_set_error();
 447     return 0;
 448 }
 449
 450 static int set_file_time( int handle, time_t access_time, time_t write_time )
 451 {
 452     struct file *file;
 453     struct utimbuf utimbuf;
 454
 455     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 456         return 0;
 457     if (!access_time || !write_time)
 458     {
 459         struct stat st;
 460         if (stat( file->name, &st ) == -1) goto error;
 461         if (!access_time) access_time = st.st_atime;
 462         if (!write_time) write_time = st.st_mtime;
 463     }
 464     utimbuf.actime  = access_time;
 465     utimbuf.modtime = write_time;
 466     if (utime( file->name, &utimbuf ) == -1) goto error;
 467     release_object( file );
 468     return 1;
 469  error:
 470     file_set_error();
 471     release_object( file );
 472     return 0;
 473 }
 474
 475 static int file_lock( struct file *file, int offset_high, int offset_low,
 476                       int count_high, int count_low )
 477 {
 478     /* FIXME: implement this */
 479     return 1;
 480 }
 481
 482 static int file_unlock( struct file *file, int offset_high, int offset_low,
 483                         int count_high, int count_low )
 484 {
 485     /* FIXME: implement this */
 486     return 1;
 487 }
 488
 489 /* create a file */
 490 DECL_HANDLER(create_file)
 491 {
 492     size_t len = get_req_strlen( req->name );
 493     struct file *file;
 494
 495     req->handle = -1;
 496     if ((file = create_file( req->name, len, req->access,
 497                              req->sharing, req->create, req->attrs )))
 498     {
 499         req->handle = alloc_handle( current->process, file, req->access, req->inherit );
 500         release_object( file );
 501     }
 502 }
 503
 504 /* allocate a file handle for a Unix fd */
 505 DECL_HANDLER(alloc_file_handle)
 506 {
 507     struct file *file;
 508
 509     req->handle = -1;
 510     if ((fd = dup(fd)) != -1)
 511     {
 512         if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE, 0 )))
 513         {
 514             req->handle = alloc_handle( current->process, file, req->access, 0 );
 515             release_object( file );
 516         }
 517         else close( fd );
 518     }
 519     else file_set_error();
 520 }
 521
 522 /* get a Unix fd to read from a file */
 523 DECL_HANDLER(get_read_fd)
 524 {
 525     struct object *obj;
 526
 527     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_READ, NULL )))
 528     {
 529         set_reply_fd( current, obj->ops->get_read_fd( obj ) );
 530         release_object( obj );
 531     }
 532 }
 533
 534 /* get a Unix fd to write to a file */
 535 DECL_HANDLER(get_write_fd)
 536 {
 537     struct object *obj;
 538
 539     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 540     {
 541         set_reply_fd( current, obj->ops->get_write_fd( obj ) );
 542         release_object( obj );
 543     }
 544 }
 545
 546 /* set a file current position */
 547 DECL_HANDLER(set_file_pointer)
 548 {
 549     int high = req->high;
 550     int low  = req->low;
 551     set_file_pointer( req->handle, &low, &high, req->whence );
 552     req->new_low  = low;
 553     req->new_high = high;
 554 }
 555
 556 /* truncate (or extend) a file */
 557 DECL_HANDLER(truncate_file)
 558 {
 559     truncate_file( req->handle );
 560 }
 561
 562 /* flush a file buffers */
 563 DECL_HANDLER(flush_file)
 564 {
 565     struct object *obj;
 566
 567     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 568     {
 569         obj->ops->flush( obj );
 570         release_object( obj );
 571     }
 572 }
 573
 574 /* set a file access and modification times */
 575 DECL_HANDLER(set_file_time)
 576 {
 577     set_file_time( req->handle, req->access_time, req->write_time );
 578 }
 579
 580 /* get a file information */
 581 DECL_HANDLER(get_file_info)
 582 {
 583     struct object *obj;
 584
 585     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 586     {
 587         obj->ops->get_file_info( obj, req );
 588         release_object( obj );
 589     }
 590 }
 591
 592 /* lock a region of a file */
 593 DECL_HANDLER(lock_file)
 594 {
 595     struct file *file;
 596
 597     if ((file = get_file_obj( current->process, req->handle, 0 )))
 598     {
 599         file_lock( file, req->offset_high, req->offset_low,
 600                    req->count_high, req->count_low );
 601         release_object( file );
 602     }
 603 }
 604
 605 /* unlock a region of a file */
 606 DECL_HANDLER(unlock_file)
 607 {
 608     struct file *file;
 609
 610     if ((file = get_file_obj( current->process, req->handle, 0 )))
 611     {
 612         file_unlock( file, req->offset_high, req->offset_low,
 613                      req->count_high, req->count_low );
 614         release_object( file );
 615     }
 616 }