server/file.c

   1 /*
   2  * Server-side file management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <fcntl.h>
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <errno.h>
  15 #ifdef HAVE_SYS_ERRNO_H
  16 #include <sys/errno.h>
  17 #endif
  18 #include <sys/stat.h>
  19 #include <sys/time.h>
  20 #include <sys/types.h>
  21 #include <time.h>
  22 #include <unistd.h>
  23 #include <utime.h>
  24
  25 #include "winerror.h"
  26 #include "winbase.h"
  27
  28 #include "handle.h"
  29 #include "thread.h"
  30 #include "request.h"
  31
  32 struct file
  33 {
  34     struct object       obj;        /* object header */
  35     struct select_user  select;     /* select user */
  36     struct file        *next;       /* next file in hashing list */
  37     char               *name;       /* file name */
  38     unsigned int        access;     /* file access (GENERIC_READ/WRITE) */
  39     unsigned int        flags;      /* flags (FILE_FLAG_*) */
  40     unsigned int        sharing;    /* file sharing mode */
  41 };
  42
  43 #define NAME_HASH_SIZE 37
  44
  45 static struct file *file_hash[NAME_HASH_SIZE];
  46
  47 static void file_dump( struct object *obj, int verbose );
  48 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry );
  49 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry );
  50 static int file_signaled( struct object *obj, struct thread *thread );
  51 static int file_get_read_fd( struct object *obj );
  52 static int file_get_write_fd( struct object *obj );
  53 static int file_flush( struct object *obj );
  54 static int file_get_info( struct object *obj, struct get_file_info_request *req );
  55 static void file_destroy( struct object *obj );
  56
  57 static const struct object_ops file_ops =
  58 {
  59     sizeof(struct file),
  60     file_dump,
  61     file_add_queue,
  62     file_remove_queue,
  63     file_signaled,
  64     no_satisfied,
  65     file_get_read_fd,
  66     file_get_write_fd,
  67     file_flush,
  68     file_get_info,
  69     file_destroy
  70 };
  71
  72
  73 static int get_name_hash( const char *name )
  74 {
  75     int hash = 0;
  76     while (*name) hash ^= (unsigned char)*name++;
  77     return hash % NAME_HASH_SIZE;
  78 }
  79
  80 /* check if the desired access is possible without violating */
  81 /* the sharing mode of other opens of the same file */
  82 static int check_sharing( const char *name, int hash, unsigned int access,
  83                           unsigned int sharing )
  84 {
  85     struct file *file;
  86     unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
  87     unsigned int existing_access = 0;
  88
  89     for (file = file_hash[hash]; file; file = file->next)
  90     {
  91         if (strcmp( file->name, name )) continue;
  92         existing_sharing &= file->sharing;
  93         existing_access |= file->access;
  94     }
  95     if ((access & GENERIC_READ) && !(existing_sharing & FILE_SHARE_READ)) goto error;
  96     if ((access & GENERIC_WRITE) && !(existing_sharing & FILE_SHARE_WRITE)) goto error;
  97     if ((existing_access & GENERIC_READ) && !(sharing & FILE_SHARE_READ)) goto error;
  98     if ((existing_access & GENERIC_WRITE) && !(sharing & FILE_SHARE_WRITE)) goto error;
  99     return 1;
 100  error:
 101     set_error( ERROR_SHARING_VIOLATION );
 102     return 0;
 103 }
 104
 105 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing,
 106                                         unsigned int attrs )
 107 {
 108     struct file *file;
 109     if ((file = alloc_object( &file_ops )))
 110     {
 111         file->name           = NULL;
 112         file->next           = NULL;
 113         file->select.fd      = fd;
 114         file->select.func    = default_select_event;
 115         file->select.private = file;
 116         file->access         = access;
 117         file->flags          = attrs;
 118         file->sharing        = sharing;
 119         register_select_user( &file->select );
 120     }
 121     return file;
 122 }
 123
 124
 125 static struct file *create_file( const char *nameptr, size_t len, unsigned int access,
 126                                  unsigned int sharing, int create, unsigned int attrs )
 127 {
 128     struct file *file;
 129     int hash, flags;
 130     struct stat st;
 131     char *name;
 132     int fd = -1;
 133
 134     if (!(name = mem_alloc( len + 1 ))) return NULL;
 135     memcpy( name, nameptr, len );
 136     name[len] = 0;
 137
 138     /* check sharing mode */
 139     hash = get_name_hash( name );
 140     if (!check_sharing( name, hash, access, sharing )) goto error;
 141
 142     switch(create)
 143     {
 144     case CREATE_NEW:        flags = O_CREAT | O_EXCL; break;
 145     case CREATE_ALWAYS:     flags = O_CREAT | O_TRUNC; break;
 146     case OPEN_ALWAYS:       flags = O_CREAT; break;
 147     case TRUNCATE_EXISTING: flags = O_TRUNC; break;
 148     case OPEN_EXISTING:     flags = 0; break;
 149     default:                set_error( ERROR_INVALID_PARAMETER ); goto error;
 150     }
 151     switch(access & (GENERIC_READ | GENERIC_WRITE))
 152     {
 153     case 0: break;
 154     case GENERIC_READ:  flags |= O_RDONLY; break;
 155     case GENERIC_WRITE: flags |= O_WRONLY; break;
 156     case GENERIC_READ|GENERIC_WRITE: flags |= O_RDWR; break;
 157     }
 158
 159     /* FIXME: should set error to ERROR_ALREADY_EXISTS if file existed before */
 160     if ((fd = open( name, flags | O_NONBLOCK,
 161                     (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666 )) == -1)
 162         goto file_error;
 163     /* refuse to open a directory */
 164     if (fstat( fd, &st ) == -1) goto file_error;
 165     if (S_ISDIR(st.st_mode))
 166     {
 167         set_error( ERROR_ACCESS_DENIED );
 168         goto error;
 169     }
 170
 171     if (!(file = create_file_for_fd( fd, access, sharing, attrs ))) goto error;
 172     file->name = name;
 173     file->next = file_hash[hash];
 174     file_hash[hash] = file;
 175     return file;
 176
 177  file_error:
 178     file_set_error();
 179  error:
 180     if (fd != -1) close( fd );
 181     free( name );
 182     return NULL;
 183 }
 184
 185 /* Create an anonymous Unix file */
 186 int create_anonymous_file(void)
 187 {
 188     char *name;
 189     int fd;
 190
 191     do
 192     {
 193         if (!(name = tmpnam(NULL)))
 194         {
 195             set_error( ERROR_TOO_MANY_OPEN_FILES );
 196             return -1;
 197         }
 198         fd = open( name, O_CREAT | O_EXCL | O_RDWR, 0600 );
 199     } while ((fd == -1) && (errno == EEXIST));
 200     if (fd == -1)
 201     {
 202         file_set_error();
 203         return -1;
 204     }
 205     unlink( name );
 206     return fd;
 207 }
 208
 209 /* Create a temp file for anonymous mappings */
 210 struct file *create_temp_file( int access )
 211 {
 212     struct file *file;
 213     int fd;
 214
 215     if ((fd = create_anonymous_file()) == -1) return NULL;
 216     if (!(file = create_file_for_fd( fd, access, 0, 0 ))) close( fd );
 217     return file;
 218 }
 219
 220 static void file_dump( struct object *obj, int verbose )
 221 {
 222     struct file *file = (struct file *)obj;
 223     assert( obj->ops == &file_ops );
 224     fprintf( stderr, "File fd=%d flags=%08x name='%s'\n",
 225              file->select.fd, file->flags, file->name );
 226 }
 227
 228 static int file_add_queue( struct object *obj, struct wait_queue_entry *entry )
 229 {
 230     struct file *file = (struct file *)obj;
 231     assert( obj->ops == &file_ops );
 232     if (!obj->head)  /* first on the queue */
 233     {
 234         int events = 0;
 235         if (file->access & GENERIC_READ) events |= READ_EVENT;
 236         if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 237         set_select_events( &file->select, events );
 238     }
 239     add_queue( obj, entry );
 240     return 1;
 241 }
 242
 243 static void file_remove_queue( struct object *obj, struct wait_queue_entry *entry )
 244 {
 245     struct file *file = (struct file *)grab_object(obj);
 246     assert( obj->ops == &file_ops );
 247
 248     remove_queue( obj, entry );
 249     if (!obj->head)  /* last on the queue is gone */
 250         set_select_events( &file->select, 0 );
 251     release_object( obj );
 252 }
 253
 254 static int file_signaled( struct object *obj, struct thread *thread )
 255 {
 256     int events = 0;
 257     struct file *file = (struct file *)obj;
 258     assert( obj->ops == &file_ops );
 259
 260     if (file->access & GENERIC_READ) events |= READ_EVENT;
 261     if (file->access & GENERIC_WRITE) events |= WRITE_EVENT;
 262     if (check_select_events( &file->select, events ))
 263     {
 264         /* stop waiting on select() if we are signaled */
 265         set_select_events( &file->select, 0 );
 266         return 1;
 267     }
 268     else
 269     {
 270         /* restart waiting on select() if we are no longer signaled */
 271         if (obj->head) set_select_events( &file->select, events );
 272         return 0;
 273     }
 274 }
 275
 276 static int file_get_read_fd( struct object *obj )
 277 {
 278     struct file *file = (struct file *)obj;
 279     assert( obj->ops == &file_ops );
 280     return dup( file->select.fd );
 281 }
 282
 283 static int file_get_write_fd( struct object *obj )
 284 {
 285     struct file *file = (struct file *)obj;
 286     assert( obj->ops == &file_ops );
 287     return dup( file->select.fd );
 288 }
 289
 290 static int file_flush( struct object *obj )
 291 {
 292     int ret;
 293     struct file *file = (struct file *)grab_object(obj);
 294     assert( obj->ops == &file_ops );
 295
 296     ret = (fsync( file->select.fd ) != -1);
 297     if (!ret) file_set_error();
 298     release_object( file );
 299     return ret;
 300 }
 301
 302 static int file_get_info( struct object *obj, struct get_file_info_request *req )
 303 {
 304     struct stat st;
 305     struct file *file = (struct file *)obj;
 306     assert( obj->ops == &file_ops );
 307
 308     if (fstat( file->select.fd, &st ) == -1)
 309     {
 310         file_set_error();
 311         return 0;
 312     }
 313     if (S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) ||
 314         S_ISSOCK(st.st_mode) || isatty(file->select.fd)) req->type = FILE_TYPE_CHAR;
 315     else req->type = FILE_TYPE_DISK;
 316     if (S_ISDIR(st.st_mode)) req->attr = FILE_ATTRIBUTE_DIRECTORY;
 317     else req->attr = FILE_ATTRIBUTE_ARCHIVE;
 318     if (!(st.st_mode & S_IWUSR)) req->attr |= FILE_ATTRIBUTE_READONLY;
 319     req->access_time = st.st_atime;
 320     req->write_time  = st.st_mtime;
 321     req->size_high   = 0;
 322     req->size_low    = S_ISDIR(st.st_mode) ? 0 : st.st_size;
 323     req->links       = st.st_nlink;
 324     req->index_high  = st.st_dev;
 325     req->index_low   = st.st_ino;
 326     req->serial      = 0; /* FIXME */
 327     return 1;
 328 }
 329
 330 static void file_destroy( struct object *obj )
 331 {
 332     struct file *file = (struct file *)obj;
 333     assert( obj->ops == &file_ops );
 334
 335     if (file->name)
 336     {
 337         /* remove it from the hashing list */
 338         struct file **pptr = &file_hash[get_name_hash( file->name )];
 339         while (*pptr && *pptr != file) pptr = &(*pptr)->next;
 340         assert( *pptr );
 341         *pptr = (*pptr)->next;
 342         if (file->flags & FILE_FLAG_DELETE_ON_CLOSE) unlink( file->name );
 343         free( file->name );
 344     }
 345     unregister_select_user( &file->select );
 346     close( file->select.fd );
 347 }
 348
 349 /* set the last error depending on errno */
 350 void file_set_error(void)
 351 {
 352     switch (errno)
 353     {
 354     case EAGAIN:    set_error( ERROR_SHARING_VIOLATION ); break;
 355     case EBADF:     set_error( ERROR_INVALID_HANDLE ); break;
 356     case ENOSPC:    set_error( ERROR_HANDLE_DISK_FULL ); break;
 357     case EACCES:
 358     case EPERM:     set_error( ERROR_ACCESS_DENIED ); break;
 359     case EROFS:     set_error( ERROR_WRITE_PROTECT ); break;
 360     case EBUSY:     set_error( ERROR_LOCK_VIOLATION ); break;
 361     case ENOENT:    set_error( ERROR_FILE_NOT_FOUND ); break;
 362     case EISDIR:    set_error( ERROR_CANNOT_MAKE ); break;
 363     case ENFILE:
 364     case EMFILE:    set_error( ERROR_NO_MORE_FILES ); break;
 365     case EEXIST:    set_error( ERROR_FILE_EXISTS ); break;
 366     case EINVAL:    set_error( ERROR_INVALID_PARAMETER ); break;
 367     case ESPIPE:    set_error( ERROR_SEEK ); break;
 368     case ENOTEMPTY: set_error( ERROR_DIR_NOT_EMPTY ); break;
 369     case EIO:       set_error( ERROR_NOACCESS ); break;
 370     default:        perror("file_set_error"); set_error( ERROR_UNKNOWN ); break;
 371     }
 372 }
 373
 374 struct file *get_file_obj( struct process *process, int handle, unsigned int access )
 375 {
 376     return (struct file *)get_handle_obj( process, handle, access, &file_ops );
 377 }
 378
 379 int file_get_mmap_fd( struct file *file )
 380 {
 381     return dup( file->select.fd );
 382 }
 383
 384 static int set_file_pointer( int handle, int *low, int *high, int whence )
 385 {
 386     struct file *file;
 387     int result;
 388
 389     if (*high)
 390     {
 391         fprintf( stderr, "set_file_pointer: offset > 4Gb not supported yet\n" );
 392         set_error( ERROR_INVALID_PARAMETER );
 393         return 0;
 394     }
 395
 396     if (!(file = get_file_obj( current->process, handle, 0 )))
 397         return 0;
 398     if ((result = lseek( file->select.fd, *low, whence )) == -1)
 399     {
 400         /* Check for seek before start of file */
 401         if ((errno == EINVAL) && (whence != SEEK_SET) && (*low < 0))
 402             set_error( ERROR_NEGATIVE_SEEK );
 403         else
 404             file_set_error();
 405         release_object( file );
 406         return 0;
 407     }
 408     *low = result;
 409     release_object( file );
 410     return 1;
 411 }
 412
 413 static int truncate_file( int handle )
 414 {
 415     struct file *file;
 416     int result;
 417
 418     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 419         return 0;
 420     if (((result = lseek( file->select.fd, 0, SEEK_CUR )) == -1) ||
 421         (ftruncate( file->select.fd, result ) == -1))
 422     {
 423         file_set_error();
 424         release_object( file );
 425         return 0;
 426     }
 427     release_object( file );
 428     return 1;
 429
 430 }
 431
 432 /* try to grow the file to the specified size */
 433 int grow_file( struct file *file, int size_high, int size_low )
 434 {
 435     struct stat st;
 436
 437     if (size_high)
 438     {
 439         set_error( ERROR_INVALID_PARAMETER );
 440         return 0;
 441     }
 442     if (fstat( file->select.fd, &st ) == -1)
 443     {
 444         file_set_error();
 445         return 0;
 446     }
 447     if (st.st_size >= size_low) return 1;  /* already large enough */
 448     if (ftruncate( file->select.fd, size_low ) != -1) return 1;
 449     file_set_error();
 450     return 0;
 451 }
 452
 453 static int set_file_time( int handle, time_t access_time, time_t write_time )
 454 {
 455     struct file *file;
 456     struct utimbuf utimbuf;
 457
 458     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 459         return 0;
 460     if (!access_time || !write_time)
 461     {
 462         struct stat st;
 463         if (stat( file->name, &st ) == -1) goto error;
 464         if (!access_time) access_time = st.st_atime;
 465         if (!write_time) write_time = st.st_mtime;
 466     }
 467     utimbuf.actime  = access_time;
 468     utimbuf.modtime = write_time;
 469     if (utime( file->name, &utimbuf ) == -1) goto error;
 470     release_object( file );
 471     return 1;
 472  error:
 473     file_set_error();
 474     release_object( file );
 475     return 0;
 476 }
 477
 478 static int file_lock( struct file *file, int offset_high, int offset_low,
 479                       int count_high, int count_low )
 480 {
 481     /* FIXME: implement this */
 482     return 1;
 483 }
 484
 485 static int file_unlock( struct file *file, int offset_high, int offset_low,
 486                         int count_high, int count_low )
 487 {
 488     /* FIXME: implement this */
 489     return 1;
 490 }
 491
 492 /* create a file */
 493 DECL_HANDLER(create_file)
 494 {
 495     size_t len = get_req_strlen( req->name );
 496     struct file *file;
 497
 498     req->handle = -1;
 499     if ((file = create_file( req->name, len, req->access,
 500                              req->sharing, req->create, req->attrs )))
 501     {
 502         req->handle = alloc_handle( current->process, file, req->access, req->inherit );
 503         release_object( file );
 504     }
 505 }
 506
 507 /* allocate a file handle for a Unix fd */
 508 DECL_HANDLER(alloc_file_handle)
 509 {
 510     struct file *file;
 511
 512     req->handle = -1;
 513     if ((fd = dup(fd)) != -1)
 514     {
 515         if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE, 0 )))
 516         {
 517             req->handle = alloc_handle( current->process, file, req->access, 0 );
 518             release_object( file );
 519         }
 520         else close( fd );
 521     }
 522     else file_set_error();
 523 }
 524
 525 /* get a Unix fd to read from a file */
 526 DECL_HANDLER(get_read_fd)
 527 {
 528     struct object *obj;
 529
 530     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_READ, NULL )))
 531     {
 532         set_reply_fd( current, obj->ops->get_read_fd( obj ) );
 533         release_object( obj );
 534     }
 535 }
 536
 537 /* get a Unix fd to write to a file */
 538 DECL_HANDLER(get_write_fd)
 539 {
 540     struct object *obj;
 541
 542     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 543     {
 544         set_reply_fd( current, obj->ops->get_write_fd( obj ) );
 545         release_object( obj );
 546     }
 547 }
 548
 549 /* set a file current position */
 550 DECL_HANDLER(set_file_pointer)
 551 {
 552     int high = req->high;
 553     int low  = req->low;
 554     set_file_pointer( req->handle, &low, &high, req->whence );
 555     req->new_low  = low;
 556     req->new_high = high;
 557 }
 558
 559 /* truncate (or extend) a file */
 560 DECL_HANDLER(truncate_file)
 561 {
 562     truncate_file( req->handle );
 563 }
 564
 565 /* flush a file buffers */
 566 DECL_HANDLER(flush_file)
 567 {
 568     struct object *obj;
 569
 570     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 571     {
 572         obj->ops->flush( obj );
 573         release_object( obj );
 574     }
 575 }
 576
 577 /* set a file access and modification times */
 578 DECL_HANDLER(set_file_time)
 579 {
 580     set_file_time( req->handle, req->access_time, req->write_time );
 581 }
 582
 583 /* get a file information */
 584 DECL_HANDLER(get_file_info)
 585 {
 586     struct object *obj;
 587
 588     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 589     {
 590         obj->ops->get_file_info( obj, req );
 591         release_object( obj );
 592     }
 593 }
 594
 595 /* lock a region of a file */
 596 DECL_HANDLER(lock_file)
 597 {
 598     struct file *file;
 599
 600     if ((file = get_file_obj( current->process, req->handle, 0 )))
 601     {
 602         file_lock( file, req->offset_high, req->offset_low,
 603                    req->count_high, req->count_low );
 604         release_object( file );
 605     }
 606 }
 607
 608 /* unlock a region of a file */
 609 DECL_HANDLER(unlock_file)
 610 {
 611     struct file *file;
 612
 613     if ((file = get_file_obj( current->process, req->handle, 0 )))
 614     {
 615         file_unlock( file, req->offset_high, req->offset_low,
 616                      req->count_high, req->count_low );
 617         release_object( file );
 618     }
 619 }