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 #ifdef HAVE_SYS_ERRNO_H
  14 #include <sys/errno.h>
  15 #endif
  16 #include <sys/stat.h>
  17 #include <sys/time.h>
  18 #include <sys/types.h>
  19 #include <time.h>
  20 #include <unistd.h>
  21 #include <utime.h>
  22
  23 #include "winerror.h"
  24 #include "winbase.h"
  25
  26 #include "handle.h"
  27 #include "thread.h"
  28 #include "request.h"
  29
  30 struct file
  31 {
  32     struct object       obj;        /* object header */
  33     struct select_user  select;     /* select user */
  34     struct file        *next;       /* next file in hashing list */
  35     char               *name;       /* file name */
  36     unsigned int        access;     /* file access (GENERIC_READ/WRITE) */
  37     unsigned int        flags;      /* flags (FILE_FLAG_*) */
  38     unsigned int        sharing;    /* file sharing mode */
  39 };
  40
  41 #define NAME_HASH_SIZE 37
  42
  43 static struct file *file_hash[NAME_HASH_SIZE];
  44
  45 static void file_dump( struct object *obj, int verbose );
  46 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry );
  47 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry );
  48 static int file_signaled( struct object *obj, struct thread *thread );
  49 static int file_get_read_fd( struct object *obj );
  50 static int file_get_write_fd( struct object *obj );
  51 static int file_flush( struct object *obj );
  52 static int file_get_info( struct object *obj, struct get_file_info_request *req );
  53 static void file_destroy( struct object *obj );
  54
  55 static const struct object_ops file_ops =
  56 {
  57     sizeof(struct file),
  58     file_dump,
  59     file_add_queue,
  60     file_remove_queue,
  61     file_signaled,
  62     no_satisfied,
  63     file_get_read_fd,
  64     file_get_write_fd,
  65     file_flush,
  66     file_get_info,
  67     file_destroy
  68 };
  69
  70
  71 static int get_name_hash( const char *name )
  72 {
  73     int hash = 0;
  74     while (*name) hash ^= *name++;
  75     return hash % NAME_HASH_SIZE;
  76 }
  77
  78 /* check if the desired access is possible without violating */
  79 /* the sharing mode of other opens of the same file */
  80 static int check_sharing( const char *name, int hash, unsigned int access,
  81                           unsigned int sharing )
  82 {
  83     struct file *file;
  84     unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
  85     unsigned int existing_access = 0;
  86
  87     for (file = file_hash[hash]; file; file = file->next)
  88     {
  89         if (strcmp( file->name, name )) continue;
  90         existing_sharing &= file->sharing;
  91         existing_access |= file->access;
  92     }
  93     if ((access & GENERIC_READ) && !(existing_sharing & FILE_SHARE_READ)) goto error;
  94     if ((access & GENERIC_WRITE) && !(existing_sharing & FILE_SHARE_WRITE)) goto error;
  95     if ((existing_access & GENERIC_READ) && !(sharing & FILE_SHARE_READ)) goto error;
  96     if ((existing_access & GENERIC_WRITE) && !(sharing & FILE_SHARE_WRITE)) goto error;
  97     return 1;
  98  error:
  99     set_error( ERROR_SHARING_VIOLATION );
 100     return 0;
 101 }
 102
 103 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing,
 104                                         unsigned int attrs )
 105 {
 106     struct file *file;
 107     if ((file = alloc_object( &file_ops )))
 108     {
 109         file->name           = NULL;
 110         file->next           = NULL;
 111         file->select.fd      = fd;
 112         file->select.func    = default_select_event;
 113         file->select.private = file;
 114         file->access         = access;
 115         file->flags          = attrs;
 116         file->sharing        = sharing;
 117         register_select_user( &file->select );
 118     }
 119     return file;
 120 }
 121
 122
 123 static struct file *create_file( const char *nameptr, size_t len, unsigned int access,
 124                                  unsigned int sharing, int create, unsigned int attrs )
 125 {
 126     struct file *file;
 127     int hash, flags;
 128     struct stat st;
 129     char *name;
 130     int fd = -1;
 131
 132     if (!(name = mem_alloc( len + 1 ))) return NULL;
 133     memcpy( name, nameptr, len );
 134     name[len] = 0;
 135
 136     /* check sharing mode */
 137     hash = get_name_hash( name );
 138     if (!check_sharing( name, hash, access, sharing )) goto error;
 139
 140     switch(create)
 141     {
 142     case CREATE_NEW:        flags = O_CREAT | O_EXCL; break;
 143     case CREATE_ALWAYS:     flags = O_CREAT | O_TRUNC; break;
 144     case OPEN_ALWAYS:       flags = O_CREAT; break;
 145     case TRUNCATE_EXISTING: flags = O_TRUNC; break;
 146     case OPEN_EXISTING:     flags = 0; break;
 147     default:                set_error( ERROR_INVALID_PARAMETER ); goto error;
 148     }
 149     switch(access & (GENERIC_READ | GENERIC_WRITE))
 150     {
 151     case 0: break;
 152     case GENERIC_READ:  flags |= O_RDONLY; break;
 153     case GENERIC_WRITE: flags |= O_WRONLY; break;
 154     case GENERIC_READ|GENERIC_WRITE: flags |= O_RDWR; break;
 155     }
 156
 157     /* FIXME: should set error to ERROR_ALREADY_EXISTS if file existed before */
 158     if ((fd = open( name, flags | O_NONBLOCK,
 159                     (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666 )) == -1)
 160         goto file_error;
 161     /* refuse to open a directory */
 162     if (fstat( fd, &st ) == -1) goto file_error;
 163     if (S_ISDIR(st.st_mode))
 164     {
 165         set_error( ERROR_ACCESS_DENIED );
 166         goto error;
 167     }
 168
 169     if (!(file = create_file_for_fd( fd, access, sharing, attrs ))) goto error;
 170     file->name = name;
 171     file->next = file_hash[hash];
 172     file_hash[hash] = file;
 173     return file;
 174
 175  file_error:
 176     file_set_error();
 177  error:
 178     if (fd != -1) close( fd );
 179     free( name );
 180     return NULL;
 181 }
 182
 183 /* Create an anonymous Unix file */
 184 int create_anonymous_file(void)
 185 {
 186     char *name;
 187     int fd;
 188
 189     do
 190     {
 191         if (!(name = tmpnam(NULL)))
 192         {
 193             set_error( ERROR_TOO_MANY_OPEN_FILES );
 194             return -1;
 195         }
 196         fd = open( name, O_CREAT | O_EXCL | O_RDWR, 0600 );
 197     } while ((fd == -1) && (errno == EEXIST));
 198     if (fd == -1)
 199     {
 200         file_set_error();
 201         return -1;
 202     }
 203     unlink( name );
 204     return fd;
 205 }
 206
 207 /* Create a temp file for anonymous mappings */
 208 struct file *create_temp_file( int access )
 209 {
 210     struct file *file;
 211     int fd;
 212
 213     if ((fd = create_anonymous_file()) == -1) return NULL;
 214     if (!(file = create_file_for_fd( fd, access, 0, 0 ))) close( fd );
 215     return file;
 216 }
 217
 218 static void file_dump( struct object *obj, int verbose )
 219 {
 220     struct file *file = (struct file *)obj;
 221     assert( obj->ops == &file_ops );
 222     fprintf( stderr, "File fd=%d flags=%08x name='%s'\n",
 223              file->select.fd, file->flags, file->name );
 224 }
 225
 226 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry )
 227 {
 228     struct file *file = (struct file *)obj;
 229     assert( obj->ops == &file_ops );
 230     if (!obj->head)  /* first on the queue */
 231     {
 232         int events = 0;
 233         if (file->access & GENERIC_READ) events |= READ_EVENT;
 234         if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 235         set_select_events( &file->select, events );
 236     }
 237     add_queue( obj, entry );
 238     return 1;
 239 }
 240
 241 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry )
 242 {
 243     struct file *file = (struct file *)grab_object(obj);
 244     assert( obj->ops == &file_ops );
 245
 246     remove_queue( obj, entry );
 247     if (!obj->head)  /* last on the queue is gone */
 248         set_select_events( &file->select, 0 );
 249     release_object( obj );
 250 }
 251
 252 static int file_signaled( struct object *obj, struct thread *thread )
 253 {
 254     int events = 0;
 255     struct file *file = (struct file *)obj;
 256     assert( obj->ops == &file_ops );
 257
 258     if (file->access & GENERIC_READ) events |= READ_EVENT;
 259     if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 260     if (check_select_events( &file->select, events ))
 261     {
 262         /* stop waiting on select() if we are signaled */
 263         set_select_events( &file->select, 0 );
 264         return 1;
 265     }
 266     else
 267     {
 268         /* restart waiting on select() if we are no longer signaled */
 269         if (obj->head) set_select_events( &file->select, events );
 270         return 0;
 271     }
 272 }
 273
 274 static int file_get_read_fd( struct object *obj )
 275 {
 276     struct file *file = (struct file *)obj;
 277     assert( obj->ops == &file_ops );
 278     return dup( file->select.fd );
 279 }
 280
 281 static int file_get_write_fd( struct object *obj )
 282 {
 283     struct file *file = (struct file *)obj;
 284     assert( obj->ops == &file_ops );
 285     return dup( file->select.fd );
 286 }
 287
 288 static int file_flush( struct object *obj )
 289 {
 290     int ret;
 291     struct file *file = (struct file *)grab_object(obj);
 292     assert( obj->ops == &file_ops );
 293
 294     ret = (fsync( file->select.fd ) != -1);
 295     if (!ret) file_set_error();
 296     release_object( file );
 297     return ret;
 298 }
 299
 300 static int file_get_info( struct object *obj, struct get_file_info_request *req )
 301 {
 302     struct stat st;
 303     struct file *file = (struct file *)obj;
 304     assert( obj->ops == &file_ops );
 305
 306     if (fstat( file->select.fd, &st ) == -1)
 307     {
 308         file_set_error();
 309         return 0;
 310     }
 311     if (S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) ||
 312         S_ISSOCK(st.st_mode) || isatty(file->select.fd)) req->type = FILE_TYPE_CHAR;
 313     else req->type = FILE_TYPE_DISK;
 314     if (S_ISDIR(st.st_mode)) req->attr = FILE_ATTRIBUTE_DIRECTORY;
 315     else req->attr = FILE_ATTRIBUTE_ARCHIVE;
 316     if (!(st.st_mode & S_IWUSR)) req->attr |= FILE_ATTRIBUTE_READONLY;
 317     req->access_time = st.st_atime;
 318     req->write_time  = st.st_mtime;
 319     req->size_high   = 0;
 320     req->size_low    = S_ISDIR(st.st_mode) ? 0 : st.st_size;
 321     req->links       = st.st_nlink;
 322     req->index_high  = st.st_dev;
 323     req->index_low   = st.st_ino;
 324     req->serial      = 0; /* FIXME */
 325     return 1;
 326 }
 327
 328 static void file_destroy( struct object *obj )
 329 {
 330     struct file *file = (struct file *)obj;
 331     assert( obj->ops == &file_ops );
 332
 333     if (file->name)
 334     {
 335         /* remove it from the hashing list */
 336         struct file **pptr = &file_hash[get_name_hash( file->name )];
 337         while (*pptr && *pptr != file) pptr = &(*pptr)->next;
 338         assert( *pptr );
 339         *pptr = (*pptr)->next;
 340         if (file->flags & FILE_FLAG_DELETE_ON_CLOSE) unlink( file->name );
 341         free( file->name );
 342     }
 343     unregister_select_user( &file->select );
 344     close( file->select.fd );
 345 }
 346
 347 /* set the last error depending on errno */
 348 void file_set_error(void)
 349 {
 350     switch (errno)
 351     {
 352     case EAGAIN:    set_error( ERROR_SHARING_VIOLATION ); break;
 353     case EBADF:     set_error( ERROR_INVALID_HANDLE ); break;
 354     case ENOSPC:    set_error( ERROR_HANDLE_DISK_FULL ); break;
 355     case EACCES:
 356     case EPERM:     set_error( ERROR_ACCESS_DENIED ); break;
 357     case EROFS:     set_error( ERROR_WRITE_PROTECT ); break;
 358     case EBUSY:     set_error( ERROR_LOCK_VIOLATION ); break;
 359     case ENOENT:    set_error( ERROR_FILE_NOT_FOUND ); break;
 360     case EISDIR:    set_error( ERROR_CANNOT_MAKE ); break;
 361     case ENFILE:
 362     case EMFILE:    set_error( ERROR_NO_MORE_FILES ); break;
 363     case EEXIST:    set_error( ERROR_FILE_EXISTS ); break;
 364     case EINVAL:    set_error( ERROR_INVALID_PARAMETER ); break;
 365     case ESPIPE:    set_error( ERROR_SEEK ); break;
 366     case ENOTEMPTY: set_error( ERROR_DIR_NOT_EMPTY ); break;
 367     default:        perror("file_set_error"); set_error( ERROR_UNKNOWN ); break;
 368     }
 369 }
 370
 371 struct file *get_file_obj( struct process *process, int handle,
 372                            unsigned int access )
 373 {
 374     return (struct file *)get_handle_obj( current->process, handle,
 375                                           access, &file_ops );
 376 }
 377
 378 int file_get_mmap_fd( struct file *file )
 379 {
 380     return dup( file->select.fd );
 381 }
 382
 383 static int set_file_pointer( int handle, int *low, int *high, int whence )
 384 {
 385     struct file *file;
 386     int result;
 387
 388     if (*high)
 389     {
 390         fprintf( stderr, "set_file_pointer: offset > 4Gb not supported yet\n" );
 391         set_error( ERROR_INVALID_PARAMETER );
 392         return 0;
 393     }
 394
 395     if (!(file = get_file_obj( current->process, handle, 0 )))
 396         return 0;
 397     if ((result = lseek( file->select.fd, *low, whence )) == -1)
 398     {
 399         /* Check for seek before start of file */
 400         if ((errno == EINVAL) && (whence != SEEK_SET) && (*low < 0))
 401             set_error( ERROR_NEGATIVE_SEEK );
 402         else
 403             file_set_error();
 404         release_object( file );
 405         return 0;
 406     }
 407     *low = result;
 408     release_object( file );
 409     return 1;
 410 }
 411
 412 static int truncate_file( int handle )
 413 {
 414     struct file *file;
 415     int result;
 416
 417     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 418         return 0;
 419     if (((result = lseek( file->select.fd, 0, SEEK_CUR )) == -1) ||
 420         (ftruncate( file->select.fd, result ) == -1))
 421     {
 422         file_set_error();
 423         release_object( file );
 424         return 0;
 425     }
 426     release_object( file );
 427     return 1;
 428
 429 }
 430
 431 /* try to grow the file to the specified size */
 432 int grow_file( struct file *file, int size_high, int size_low )
 433 {
 434     struct stat st;
 435
 436     if (size_high)
 437     {
 438         set_error( ERROR_INVALID_PARAMETER );
 439         return 0;
 440     }
 441     if (fstat( file->select.fd, &st ) == -1)
 442     {
 443         file_set_error();
 444         return 0;
 445     }
 446     if (st.st_size >= size_low) return 1;  /* already large enough */
 447     if (ftruncate( file->select.fd, size_low ) != -1) return 1;
 448     file_set_error();
 449     return 0;
 450 }
 451
 452 static int set_file_time( int handle, time_t access_time, time_t write_time )
 453 {
 454     struct file *file;
 455     struct utimbuf utimbuf;
 456
 457     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 458         return 0;
 459     if (!access_time || !write_time)
 460     {
 461         struct stat st;
 462         if (stat( file->name, &st ) == -1) goto error;
 463         if (!access_time) access_time = st.st_atime;
 464         if (!write_time) write_time = st.st_mtime;
 465     }
 466     utimbuf.actime  = access_time;
 467     utimbuf.modtime = write_time;
 468     if (utime( file->name, &utimbuf ) == -1) goto error;
 469     release_object( file );
 470     return 1;
 471  error:
 472     file_set_error();
 473     release_object( file );
 474     return 0;
 475 }
 476
 477 static int file_lock( struct file *file, int offset_high, int offset_low,
 478                       int count_high, int count_low )
 479 {
 480     /* FIXME: implement this */
 481     return 1;
 482 }
 483
 484 static int file_unlock( struct file *file, int offset_high, int offset_low,
 485                         int count_high, int count_low )
 486 {
 487     /* FIXME: implement this */
 488     return 1;
 489 }
 490
 491 /* create a file */
 492 DECL_HANDLER(create_file)
 493 {
 494     size_t len = get_req_strlen( req->name );
 495     struct file *file;
 496
 497     req->handle = -1;
 498     if ((file = create_file( req->name, len, req->access,
 499                              req->sharing, req->create, req->attrs )))
 500     {
 501         req->handle = alloc_handle( current->process, file, req->access, req->inherit );
 502         release_object( file );
 503     }
 504 }
 505
 506 /* allocate a file handle for a Unix fd */
 507 DECL_HANDLER(alloc_file_handle)
 508 {
 509     struct file *file;
 510
 511     req->handle = -1;
 512     if ((fd = dup(fd)) != -1)
 513     {
 514         if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE, 0 )))
 515         {
 516             req->handle = alloc_handle( current->process, file, req->access, 0 );
 517             release_object( file );
 518         }
 519         else close( fd );
 520     }
 521     else file_set_error();
 522 }
 523
 524 /* get a Unix fd to read from a file */
 525 DECL_HANDLER(get_read_fd)
 526 {
 527     struct object *obj;
 528
 529     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_READ, NULL )))
 530     {
 531         set_reply_fd( current, obj->ops->get_read_fd( obj ) );
 532         release_object( obj );
 533     }
 534 }
 535
 536 /* get a Unix fd to write to a file */
 537 DECL_HANDLER(get_write_fd)
 538 {
 539     struct object *obj;
 540
 541     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 542     {
 543         set_reply_fd( current, obj->ops->get_write_fd( obj ) );
 544         release_object( obj );
 545     }
 546 }
 547
 548 /* set a file current position */
 549 DECL_HANDLER(set_file_pointer)
 550 {
 551     int high = req->high;
 552     int low  = req->low;
 553     set_file_pointer( req->handle, &low, &high, req->whence );
 554     req->new_low  = low;
 555     req->new_high = high;
 556 }
 557
 558 /* truncate (or extend) a file */
 559 DECL_HANDLER(truncate_file)
 560 {
 561     truncate_file( req->handle );
 562 }
 563
 564 /* flush a file buffers */
 565 DECL_HANDLER(flush_file)
 566 {
 567     struct object *obj;
 568
 569     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 570     {
 571         obj->ops->flush( obj );
 572         release_object( obj );
 573     }
 574 }
 575
 576 /* set a file access and modification times */
 577 DECL_HANDLER(set_file_time)
 578 {
 579     set_file_time( req->handle, req->access_time, req->write_time );
 580 }
 581
 582 /* get a file information */
 583 DECL_HANDLER(get_file_info)
 584 {
 585     struct object *obj;
 586
 587     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 588     {
 589         obj->ops->get_file_info( obj, req );
 590         release_object( obj );
 591     }
 592 }
 593
 594 /* lock a region of a file */
 595 DECL_HANDLER(lock_file)
 596 {
 597     struct file *file;
 598
 599     if ((file = get_file_obj( current->process, req->handle, 0 )))
 600     {
 601         file_lock( file, req->offset_high, req->offset_low,
 602                    req->count_high, req->count_low );
 603         release_object( file );
 604     }
 605 }
 606
 607 /* unlock a region of a file */
 608 DECL_HANDLER(unlock_file)
 609 {
 610     struct file *file;
 611
 612     if ((file = get_file_obj( current->process, req->handle, 0 )))
 613     {
 614         file_unlock( file, req->offset_high, req->offset_low,
 615                      req->count_high, req->count_low );
 616         release_object( file );
 617     }
 618 }