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 file        *next;       /* next file in hashing list */
  36     char               *name;       /* file name */
  37     unsigned int        access;     /* file access (GENERIC_READ/WRITE) */
  38     unsigned int        flags;      /* flags (FILE_FLAG_*) */
  39     unsigned int        sharing;    /* file sharing mode */
  40 };
  41
  42 #define NAME_HASH_SIZE 37
  43
  44 static struct file *file_hash[NAME_HASH_SIZE];
  45
  46 static void file_dump( struct object *obj, int verbose );
  47 static int file_get_poll_events( struct object *obj );
  48 static int file_get_read_fd( struct object *obj );
  49 static int file_get_write_fd( struct object *obj );
  50 static int file_flush( struct object *obj );
  51 static int file_get_info( struct object *obj, struct get_file_info_request *req );
  52 static void file_destroy( struct object *obj );
  53
  54 static const struct object_ops file_ops =
  55 {
  56     sizeof(struct file),          /* size */
  57     file_dump,                    /* dump */
  58     default_poll_add_queue,       /* add_queue */
  59     default_poll_remove_queue,    /* remove_queue */
  60     default_poll_signaled,        /* signaled */
  61     no_satisfied,                 /* satisfied */
  62     file_get_poll_events,         /* get_poll_events */
  63     default_poll_event,           /* poll_event */
  64     file_get_read_fd,             /* get_read_fd */
  65     file_get_write_fd,            /* get_write_fd */
  66     file_flush,                   /* flush */
  67     file_get_info,                /* get_file_info */
  68     file_destroy                  /* destroy */
  69 };
  70
  71
  72 static int get_name_hash( const char *name )
  73 {
  74     int hash = 0;
  75     while (*name) hash ^= (unsigned char)*name++;
  76     return hash % NAME_HASH_SIZE;
  77 }
  78
  79 /* check if the desired access is possible without violating */
  80 /* the sharing mode of other opens of the same file */
  81 static int check_sharing( const char *name, int hash, unsigned int access,
  82                           unsigned int sharing )
  83 {
  84     struct file *file;
  85     unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
  86     unsigned int existing_access = 0;
  87
  88     for (file = file_hash[hash]; file; file = file->next)
  89     {
  90         if (strcmp( file->name, name )) continue;
  91         existing_sharing &= file->sharing;
  92         existing_access |= file->access;
  93     }
  94     if ((access & GENERIC_READ) && !(existing_sharing & FILE_SHARE_READ)) goto error;
  95     if ((access & GENERIC_WRITE) && !(existing_sharing & FILE_SHARE_WRITE)) goto error;
  96     if ((existing_access & GENERIC_READ) && !(sharing & FILE_SHARE_READ)) goto error;
  97     if ((existing_access & GENERIC_WRITE) && !(sharing & FILE_SHARE_WRITE)) goto error;
  98     return 1;
  99  error:
 100     set_error( STATUS_SHARING_VIOLATION );
 101     return 0;
 102 }
 103
 104 /* create a file from a file descriptor */
 105 /* if the function fails the fd is closed */
 106 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing,
 107                                         unsigned int attrs )
 108 {
 109     struct file *file;
 110     if ((file = alloc_object( &file_ops, fd )))
 111     {
 112         file->name    = NULL;
 113         file->next    = NULL;
 114         file->access  = access;
 115         file->flags   = attrs;
 116         file->sharing = sharing;
 117     }
 118     return file;
 119 }
 120
 121
 122 static struct file *create_file( const char *nameptr, size_t len, unsigned int access,
 123                                  unsigned int sharing, int create, unsigned int attrs )
 124 {
 125     struct file *file;
 126     int hash, flags;
 127     struct stat st;
 128     char *name;
 129     int fd = -1;
 130
 131     if (!(name = mem_alloc( len + 1 ))) return NULL;
 132     memcpy( name, nameptr, len );
 133     name[len] = 0;
 134
 135     /* check sharing mode */
 136     hash = get_name_hash( name );
 137     if (!check_sharing( name, hash, access, sharing )) goto error;
 138
 139     switch(create)
 140     {
 141     case CREATE_NEW:        flags = O_CREAT | O_EXCL; break;
 142     case CREATE_ALWAYS:     flags = O_CREAT | O_TRUNC; break;
 143     case OPEN_ALWAYS:       flags = O_CREAT; break;
 144     case TRUNCATE_EXISTING: flags = O_TRUNC; break;
 145     case OPEN_EXISTING:     flags = 0; break;
 146     default:                set_error( STATUS_INVALID_PARAMETER ); goto error;
 147     }
 148     switch(access & (GENERIC_READ | GENERIC_WRITE))
 149     {
 150     case 0: break;
 151     case GENERIC_READ:  flags |= O_RDONLY; break;
 152     case GENERIC_WRITE: flags |= O_WRONLY; break;
 153     case GENERIC_READ|GENERIC_WRITE: flags |= O_RDWR; break;
 154     }
 155
 156     /* FIXME: should set error to STATUS_OBJECT_NAME_COLLISION if file existed before */
 157     if ((fd = open( name, flags | O_NONBLOCK,
 158                     (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666 )) == -1)
 159         goto file_error;
 160     /* refuse to open a directory */
 161     if (fstat( fd, &st ) == -1) goto file_error;
 162     if (S_ISDIR(st.st_mode))
 163     {
 164         set_error( STATUS_ACCESS_DENIED );
 165         goto error;
 166     }
 167
 168     if (!(file = create_file_for_fd( fd, access, sharing, attrs )))
 169     {
 170         free( name );
 171         return NULL;
 172     }
 173     file->name = name;
 174     file->next = file_hash[hash];
 175     file_hash[hash] = file;
 176     return file;
 177
 178  file_error:
 179     file_set_error();
 180  error:
 181     if (fd != -1) close( fd );
 182     free( name );
 183     return NULL;
 184 }
 185
 186 /* Create an anonymous Unix file */
 187 int create_anonymous_file(void)
 188 {
 189     char *name;
 190     int fd;
 191
 192     do
 193     {
 194         if (!(name = tmpnam(NULL)))
 195         {
 196             set_error( STATUS_TOO_MANY_OPENED_FILES );
 197             return -1;
 198         }
 199         fd = open( name, O_CREAT | O_EXCL | O_RDWR, 0600 );
 200     } while ((fd == -1) && (errno == EEXIST));
 201     if (fd == -1)
 202     {
 203         file_set_error();
 204         return -1;
 205     }
 206     unlink( name );
 207     return fd;
 208 }
 209
 210 /* Create a temp file for anonymous mappings */
 211 struct file *create_temp_file( int access )
 212 {
 213     int fd;
 214
 215     if ((fd = create_anonymous_file()) == -1) return NULL;
 216     return create_file_for_fd( fd, access, 0, 0 );
 217 }
 218
 219 static void file_dump( struct object *obj, int verbose )
 220 {
 221     struct file *file = (struct file *)obj;
 222     assert( obj->ops == &file_ops );
 223     fprintf( stderr, "File fd=%d flags=%08x name='%s'\n", file->obj.fd, file->flags, file->name );
 224 }
 225
 226 static int file_get_poll_events( struct object *obj )
 227 {
 228     struct file *file = (struct file *)obj;
 229     int events = 0;
 230     assert( obj->ops == &file_ops );
 231     if (file->access & GENERIC_READ) events |= POLLIN;
 232     if (file->access & GENERIC_WRITE) events |= POLLOUT;
 233     return events;
 234 }
 235
 236 static int file_get_read_fd( struct object *obj )
 237 {
 238     struct file *file = (struct file *)obj;
 239     assert( obj->ops == &file_ops );
 240     return dup( file->obj.fd );
 241 }
 242
 243 static int file_get_write_fd( struct object *obj )
 244 {
 245     struct file *file = (struct file *)obj;
 246     assert( obj->ops == &file_ops );
 247     return dup( file->obj.fd );
 248 }
 249
 250 static int file_flush( struct object *obj )
 251 {
 252     int ret;
 253     struct file *file = (struct file *)grab_object(obj);
 254     assert( obj->ops == &file_ops );
 255
 256     ret = (fsync( file->obj.fd ) != -1);
 257     if (!ret) file_set_error();
 258     release_object( file );
 259     return ret;
 260 }
 261
 262 static int file_get_info( struct object *obj, struct get_file_info_request *req )
 263 {
 264     struct stat st;
 265     struct file *file = (struct file *)obj;
 266     assert( obj->ops == &file_ops );
 267
 268     if (fstat( file->obj.fd, &st ) == -1)
 269     {
 270         file_set_error();
 271         return 0;
 272     }
 273     if (S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) ||
 274         S_ISSOCK(st.st_mode) || isatty(file->obj.fd)) req->type = FILE_TYPE_CHAR;
 275     else req->type = FILE_TYPE_DISK;
 276     if (S_ISDIR(st.st_mode)) req->attr = FILE_ATTRIBUTE_DIRECTORY;
 277     else req->attr = FILE_ATTRIBUTE_ARCHIVE;
 278     if (!(st.st_mode & S_IWUSR)) req->attr |= FILE_ATTRIBUTE_READONLY;
 279     req->access_time = st.st_atime;
 280     req->write_time  = st.st_mtime;
 281     req->size_high   = 0;
 282     req->size_low    = S_ISDIR(st.st_mode) ? 0 : st.st_size;
 283     req->links       = st.st_nlink;
 284     req->index_high  = st.st_dev;
 285     req->index_low   = st.st_ino;
 286     req->serial      = 0; /* FIXME */
 287     return 1;
 288 }
 289
 290 static void file_destroy( struct object *obj )
 291 {
 292     struct file *file = (struct file *)obj;
 293     assert( obj->ops == &file_ops );
 294
 295     if (file->name)
 296     {
 297         /* remove it from the hashing list */
 298         struct file **pptr = &file_hash[get_name_hash( file->name )];
 299         while (*pptr && *pptr != file) pptr = &(*pptr)->next;
 300         assert( *pptr );
 301         *pptr = (*pptr)->next;
 302         if (file->flags & FILE_FLAG_DELETE_ON_CLOSE) unlink( file->name );
 303         free( file->name );
 304     }
 305 }
 306
 307 /* set the last error depending on errno */
 308 void file_set_error(void)
 309 {
 310     switch (errno)
 311     {
 312     case EAGAIN:    set_error( STATUS_SHARING_VIOLATION ); break;
 313     case EBADF:     set_error( STATUS_INVALID_HANDLE ); break;
 314     case ENOSPC:    set_error( STATUS_DISK_FULL ); break;
 315     case EACCES:
 316     case EPERM:     set_error( STATUS_ACCESS_DENIED ); break;
 317     case EROFS:     set_error( STATUS_MEDIA_WRITE_PROTECTED ); break;
 318     case EBUSY:     set_error( STATUS_FILE_LOCK_CONFLICT ); break;
 319     case ENOENT:    set_error( STATUS_NO_SUCH_FILE ); break;
 320     case EISDIR:    set_error( 0xc0010000 | ERROR_CANNOT_MAKE /* FIXME */ ); break;
 321     case ENFILE:
 322     case EMFILE:    set_error( STATUS_NO_MORE_FILES ); break;
 323     case EEXIST:    set_error( STATUS_OBJECT_NAME_COLLISION ); break;
 324     case EINVAL:    set_error( STATUS_INVALID_PARAMETER ); break;
 325     case ESPIPE:    set_error( 0xc0010000 | ERROR_SEEK /* FIXME */ ); break;
 326     case ENOTEMPTY: set_error( STATUS_DIRECTORY_NOT_EMPTY ); break;
 327     case EIO:       set_error( STATUS_ACCESS_VIOLATION ); break;
 328     default:        perror("file_set_error"); set_error( ERROR_UNKNOWN /* FIXME */ ); break;
 329     }
 330 }
 331
 332 struct file *get_file_obj( struct process *process, int handle, unsigned int access )
 333 {
 334     return (struct file *)get_handle_obj( process, handle, access, &file_ops );
 335 }
 336
 337 int file_get_mmap_fd( struct file *file )
 338 {
 339     return dup( file->obj.fd );
 340 }
 341
 342 static int set_file_pointer( int handle, int *low, int *high, int whence )
 343 {
 344     struct file *file;
 345     int result;
 346
 347     if (*high)
 348     {
 349         fprintf( stderr, "set_file_pointer: offset > 4Gb not supported yet\n" );
 350         set_error( STATUS_INVALID_PARAMETER );
 351         return 0;
 352     }
 353
 354     if (!(file = get_file_obj( current->process, handle, 0 )))
 355         return 0;
 356     if ((result = lseek( file->obj.fd, *low, whence )) == -1)
 357     {
 358         /* Check for seek before start of file */
 359         if ((errno == EINVAL) && (whence != SEEK_SET) && (*low < 0))
 360             set_error( 0xc0010000 | ERROR_NEGATIVE_SEEK /* FIXME */ );
 361         else
 362             file_set_error();
 363         release_object( file );
 364         return 0;
 365     }
 366     *low = result;
 367     release_object( file );
 368     return 1;
 369 }
 370
 371 static int truncate_file( int handle )
 372 {
 373     struct file *file;
 374     int result;
 375
 376     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 377         return 0;
 378     if (((result = lseek( file->obj.fd, 0, SEEK_CUR )) == -1) ||
 379         (ftruncate( file->obj.fd, result ) == -1))
 380     {
 381         file_set_error();
 382         release_object( file );
 383         return 0;
 384     }
 385     release_object( file );
 386     return 1;
 387
 388 }
 389
 390 /* try to grow the file to the specified size */
 391 int grow_file( struct file *file, int size_high, int size_low )
 392 {
 393     struct stat st;
 394
 395     if (size_high)
 396     {
 397         set_error( STATUS_INVALID_PARAMETER );
 398         return 0;
 399     }
 400     if (fstat( file->obj.fd, &st ) == -1)
 401     {
 402         file_set_error();
 403         return 0;
 404     }
 405     if (st.st_size >= size_low) return 1;  /* already large enough */
 406     if (ftruncate( file->obj.fd, size_low ) != -1) return 1;
 407     file_set_error();
 408     return 0;
 409 }
 410
 411 static int set_file_time( int handle, time_t access_time, time_t write_time )
 412 {
 413     struct file *file;
 414     struct utimbuf utimbuf;
 415
 416     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 417         return 0;
 418     if (!access_time || !write_time)
 419     {
 420         struct stat st;
 421         if (stat( file->name, &st ) == -1) goto error;
 422         if (!access_time) access_time = st.st_atime;
 423         if (!write_time) write_time = st.st_mtime;
 424     }
 425     utimbuf.actime  = access_time;
 426     utimbuf.modtime = write_time;
 427     if (utime( file->name, &utimbuf ) == -1) goto error;
 428     release_object( file );
 429     return 1;
 430  error:
 431     file_set_error();
 432     release_object( file );
 433     return 0;
 434 }
 435
 436 static int file_lock( struct file *file, int offset_high, int offset_low,
 437                       int count_high, int count_low )
 438 {
 439     /* FIXME: implement this */
 440     return 1;
 441 }
 442
 443 static int file_unlock( struct file *file, int offset_high, int offset_low,
 444                         int count_high, int count_low )
 445 {
 446     /* FIXME: implement this */
 447     return 1;
 448 }
 449
 450 /* create a file */
 451 DECL_HANDLER(create_file)
 452 {
 453     size_t len = get_req_strlen( req, req->name );
 454     struct file *file;
 455
 456     req->handle = -1;
 457     if ((file = create_file( req->name, len, req->access,
 458                              req->sharing, req->create, req->attrs )))
 459     {
 460         req->handle = alloc_handle( current->process, file, req->access, req->inherit );
 461         release_object( file );
 462     }
 463 }
 464
 465 /* allocate a file handle for a Unix fd */
 466 DECL_HANDLER(alloc_file_handle)
 467 {
 468     struct file *file;
 469
 470     req->handle = -1;
 471     if (current->pass_fd != -1)
 472     {
 473         if ((file = create_file_for_fd( current->pass_fd, req->access,
 474                                         FILE_SHARE_READ | FILE_SHARE_WRITE, 0 )))
 475         {
 476             req->handle = alloc_handle( current->process, file, req->access, 0 );
 477             release_object( file );
 478         }
 479         current->pass_fd = -1;
 480     }
 481     else set_error( STATUS_INVALID_PARAMETER );
 482 }
 483
 484 /* get a Unix fd to read from a file */
 485 DECL_HANDLER(get_read_fd)
 486 {
 487     struct object *obj;
 488
 489     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_READ, NULL )))
 490     {
 491         set_reply_fd( current, obj->ops->get_read_fd( obj ) );
 492         release_object( obj );
 493     }
 494 }
 495
 496 /* get a Unix fd to write to a file */
 497 DECL_HANDLER(get_write_fd)
 498 {
 499     struct object *obj;
 500
 501     if ((obj = get_handle_obj( current->process, req->handle, GENERIC_WRITE, NULL )))
 502     {
 503         set_reply_fd( current, obj->ops->get_write_fd( obj ) );
 504         release_object( obj );
 505     }
 506 }
 507
 508 /* set a file current position */
 509 DECL_HANDLER(set_file_pointer)
 510 {
 511     int high = req->high;
 512     int low  = req->low;
 513     set_file_pointer( req->handle, &low, &high, req->whence );
 514     req->new_low  = low;
 515     req->new_high = high;
 516 }
 517
 518 /* truncate (or extend) a file */
 519 DECL_HANDLER(truncate_file)
 520 {
 521     truncate_file( req->handle );
 522 }
 523
 524 /* flush a file buffers */
 525 DECL_HANDLER(flush_file)
 526 {
 527     struct object *obj;
 528
 529     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 530     {
 531         obj->ops->flush( obj );
 532         release_object( obj );
 533     }
 534 }
 535
 536 /* set a file access and modification times */
 537 DECL_HANDLER(set_file_time)
 538 {
 539     set_file_time( req->handle, req->access_time, req->write_time );
 540 }
 541
 542 /* get a file information */
 543 DECL_HANDLER(get_file_info)
 544 {
 545     struct object *obj;
 546
 547     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 548     {
 549         obj->ops->get_file_info( obj, req );
 550         release_object( obj );
 551     }
 552 }
 553
 554 /* lock a region of a file */
 555 DECL_HANDLER(lock_file)
 556 {
 557     struct file *file;
 558
 559     if ((file = get_file_obj( current->process, req->handle, 0 )))
 560     {
 561         file_lock( file, req->offset_high, req->offset_low,
 562                    req->count_high, req->count_low );
 563         release_object( file );
 564     }
 565 }
 566
 567 /* unlock a region of a file */
 568 DECL_HANDLER(unlock_file)
 569 {
 570     struct file *file;
 571
 572     if ((file = get_file_obj( current->process, req->handle, 0 )))
 573     {
 574         file_unlock( file, req->offset_high, req->offset_low,
 575                      req->count_high, req->count_low );
 576         release_object( file );
 577     }
 578 }