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_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),          /* size */
  56     file_dump,                    /* dump */
  57     default_poll_add_queue,       /* add_queue */
  58     default_poll_remove_queue,    /* remove_queue */
  59     default_poll_signaled,        /* signaled */
  60     no_satisfied,                 /* satisfied */
  61     file_get_poll_events,         /* get_poll_events */
  62     default_poll_event,           /* poll_event */
  63     file_get_fd,                  /* get_fd */
  64     file_flush,                   /* flush */
  65     file_get_info,                /* get_file_info */
  66     file_destroy                  /* destroy */
  67 };
  68
  69
  70 static int get_name_hash( const char *name )
  71 {
  72     int hash = 0;
  73     while (*name) hash ^= (unsigned char)*name++;
  74     return hash % NAME_HASH_SIZE;
  75 }
  76
  77 /* check if the desired access is possible without violating */
  78 /* the sharing mode of other opens of the same file */
  79 static int check_sharing( const char *name, int hash, unsigned int access,
  80                           unsigned int sharing )
  81 {
  82     struct file *file;
  83     unsigned int existing_sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
  84     unsigned int existing_access = 0;
  85
  86     for (file = file_hash[hash]; file; file = file->next)
  87     {
  88         if (strcmp( file->name, name )) continue;
  89         existing_sharing &= file->sharing;
  90         existing_access |= file->access;
  91     }
  92     if ((access & GENERIC_READ) && !(existing_sharing & FILE_SHARE_READ)) goto error;
  93     if ((access & GENERIC_WRITE) && !(existing_sharing & FILE_SHARE_WRITE)) goto error;
  94     if ((existing_access & GENERIC_READ) && !(sharing & FILE_SHARE_READ)) goto error;
  95     if ((existing_access & GENERIC_WRITE) && !(sharing & FILE_SHARE_WRITE)) goto error;
  96     return 1;
  97  error:
  98     set_error( STATUS_SHARING_VIOLATION );
  99     return 0;
 100 }
 101
 102 /* create a file from a file descriptor */
 103 /* if the function fails the fd is closed */
 104 static struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing,
 105                                         unsigned int attrs )
 106 {
 107     struct file *file;
 108     if ((file = alloc_object( &file_ops, fd )))
 109     {
 110         file->name    = NULL;
 111         file->next    = NULL;
 112         file->access  = access;
 113         file->flags   = attrs;
 114         file->sharing = sharing;
 115     }
 116     return file;
 117 }
 118
 119
 120 static struct file *create_file( const char *nameptr, size_t len, unsigned int access,
 121                                  unsigned int sharing, int create, unsigned int attrs )
 122 {
 123     struct file *file;
 124     int hash, flags;
 125     struct stat st;
 126     char *name;
 127     int fd = -1;
 128
 129     if (!(name = mem_alloc( len + 1 ))) return NULL;
 130     memcpy( name, nameptr, len );
 131     name[len] = 0;
 132
 133     /* check sharing mode */
 134     hash = get_name_hash( name );
 135     if (!check_sharing( name, hash, access, sharing )) goto error;
 136
 137     switch(create)
 138     {
 139     case CREATE_NEW:        flags = O_CREAT | O_EXCL; break;
 140     case CREATE_ALWAYS:     flags = O_CREAT | O_TRUNC; break;
 141     case OPEN_ALWAYS:       flags = O_CREAT; break;
 142     case TRUNCATE_EXISTING: flags = O_TRUNC; break;
 143     case OPEN_EXISTING:     flags = 0; break;
 144     default:                set_error( STATUS_INVALID_PARAMETER ); goto error;
 145     }
 146     switch(access & (GENERIC_READ | GENERIC_WRITE))
 147     {
 148     case 0: break;
 149     case GENERIC_READ:  flags |= O_RDONLY; break;
 150     case GENERIC_WRITE: flags |= O_WRONLY; break;
 151     case GENERIC_READ|GENERIC_WRITE: flags |= O_RDWR; break;
 152     }
 153
 154     /* FIXME: should set error to STATUS_OBJECT_NAME_COLLISION if file existed before */
 155     if ((fd = open( name, flags | O_NONBLOCK,
 156                     (attrs & FILE_ATTRIBUTE_READONLY) ? 0444 : 0666 )) == -1)
 157         goto file_error;
 158     /* refuse to open a directory */
 159     if (fstat( fd, &st ) == -1) goto file_error;
 160     if (S_ISDIR(st.st_mode))
 161     {
 162         set_error( STATUS_ACCESS_DENIED );
 163         goto error;
 164     }
 165
 166     if (!(file = create_file_for_fd( fd, access, sharing, attrs )))
 167     {
 168         free( name );
 169         return NULL;
 170     }
 171     file->name = name;
 172     file->next = file_hash[hash];
 173     file_hash[hash] = file;
 174     return file;
 175
 176  file_error:
 177     file_set_error();
 178  error:
 179     if (fd != -1) close( fd );
 180     free( name );
 181     return NULL;
 182 }
 183
 184 /* check if two file objects point to the same file */
 185 int is_same_file( struct file *file1, struct file *file2 )
 186 {
 187     return !strcmp( file1->name, file2->name );
 188 }
 189
 190 /* Create an anonymous Unix file */
 191 int create_anonymous_file(void)
 192 {
 193     char *name;
 194     int fd;
 195
 196     do
 197     {
 198         if (!(name = tmpnam(NULL)))
 199         {
 200             set_error( STATUS_TOO_MANY_OPENED_FILES );
 201             return -1;
 202         }
 203         fd = open( name, O_CREAT | O_EXCL | O_RDWR, 0600 );
 204     } while ((fd == -1) && (errno == EEXIST));
 205     if (fd == -1)
 206     {
 207         file_set_error();
 208         return -1;
 209     }
 210     unlink( name );
 211     return fd;
 212 }
 213
 214 /* Create a temp file for anonymous mappings */
 215 struct file *create_temp_file( int access )
 216 {
 217     int fd;
 218
 219     if ((fd = create_anonymous_file()) == -1) return NULL;
 220     return create_file_for_fd( fd, access, 0, 0 );
 221 }
 222
 223 static void file_dump( struct object *obj, int verbose )
 224 {
 225     struct file *file = (struct file *)obj;
 226     assert( obj->ops == &file_ops );
 227     fprintf( stderr, "File fd=%d flags=%08x name='%s'\n", file->obj.fd, file->flags, file->name );
 228 }
 229
 230 static int file_get_poll_events( struct object *obj )
 231 {
 232     struct file *file = (struct file *)obj;
 233     int events = 0;
 234     assert( obj->ops == &file_ops );
 235     if (file->access & GENERIC_READ) events |= POLLIN;
 236     if (file->access & GENERIC_WRITE) events |= POLLOUT;
 237     return events;
 238 }
 239
 240 static int file_get_fd( struct object *obj )
 241 {
 242     struct file *file = (struct file *)obj;
 243     assert( obj->ops == &file_ops );
 244     return file->obj.fd;
 245 }
 246
 247 static int file_flush( struct object *obj )
 248 {
 249     int ret;
 250     struct file *file = (struct file *)grab_object(obj);
 251     assert( obj->ops == &file_ops );
 252
 253     ret = (fsync( file->obj.fd ) != -1);
 254     if (!ret) file_set_error();
 255     release_object( file );
 256     return ret;
 257 }
 258
 259 static int file_get_info( struct object *obj, struct get_file_info_request *req )
 260 {
 261     struct stat st;
 262     struct file *file = (struct file *)obj;
 263     assert( obj->ops == &file_ops );
 264
 265     if (fstat( file->obj.fd, &st ) == -1)
 266     {
 267         file_set_error();
 268         return 0;
 269     }
 270     if (S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) ||
 271         S_ISSOCK(st.st_mode) || isatty(file->obj.fd)) req->type = FILE_TYPE_CHAR;
 272     else req->type = FILE_TYPE_DISK;
 273     if (S_ISDIR(st.st_mode)) req->attr = FILE_ATTRIBUTE_DIRECTORY;
 274     else req->attr = FILE_ATTRIBUTE_ARCHIVE;
 275     if (!(st.st_mode & S_IWUSR)) req->attr |= FILE_ATTRIBUTE_READONLY;
 276     req->access_time = st.st_atime;
 277     req->write_time  = st.st_mtime;
 278     req->size_high   = 0;
 279     req->size_low    = S_ISDIR(st.st_mode) ? 0 : st.st_size;
 280     req->links       = st.st_nlink;
 281     req->index_high  = st.st_dev;
 282     req->index_low   = st.st_ino;
 283     req->serial      = 0; /* FIXME */
 284     return 1;
 285 }
 286
 287 static void file_destroy( struct object *obj )
 288 {
 289     struct file *file = (struct file *)obj;
 290     assert( obj->ops == &file_ops );
 291
 292     if (file->name)
 293     {
 294         /* remove it from the hashing list */
 295         struct file **pptr = &file_hash[get_name_hash( file->name )];
 296         while (*pptr && *pptr != file) pptr = &(*pptr)->next;
 297         assert( *pptr );
 298         *pptr = (*pptr)->next;
 299         if (file->flags & FILE_FLAG_DELETE_ON_CLOSE) unlink( file->name );
 300         free( file->name );
 301     }
 302 }
 303
 304 /* set the last error depending on errno */
 305 void file_set_error(void)
 306 {
 307     switch (errno)
 308     {
 309     case EAGAIN:    set_error( STATUS_SHARING_VIOLATION ); break;
 310     case EBADF:     set_error( STATUS_INVALID_HANDLE ); break;
 311     case ENOSPC:    set_error( STATUS_DISK_FULL ); break;
 312     case EACCES:
 313     case EPERM:     set_error( STATUS_ACCESS_DENIED ); break;
 314     case EROFS:     set_error( STATUS_MEDIA_WRITE_PROTECTED ); break;
 315     case EBUSY:     set_error( STATUS_FILE_LOCK_CONFLICT ); break;
 316     case ENOENT:    set_error( STATUS_NO_SUCH_FILE ); break;
 317     case EISDIR:    set_error( 0xc0010000 | ERROR_CANNOT_MAKE /* FIXME */ ); break;
 318     case ENFILE:
 319     case EMFILE:    set_error( STATUS_NO_MORE_FILES ); break;
 320     case EEXIST:    set_error( STATUS_OBJECT_NAME_COLLISION ); break;
 321     case EINVAL:    set_error( STATUS_INVALID_PARAMETER ); break;
 322     case ESPIPE:    set_error( 0xc0010000 | ERROR_SEEK /* FIXME */ ); break;
 323     case ENOTEMPTY: set_error( STATUS_DIRECTORY_NOT_EMPTY ); break;
 324     case EIO:       set_error( STATUS_ACCESS_VIOLATION ); break;
 325     default:        perror("file_set_error"); set_error( ERROR_UNKNOWN /* FIXME */ ); break;
 326     }
 327 }
 328
 329 struct file *get_file_obj( struct process *process, handle_t handle, unsigned int access )
 330 {
 331     return (struct file *)get_handle_obj( process, handle, access, &file_ops );
 332 }
 333
 334 static int set_file_pointer( handle_t handle, int *low, int *high, int whence )
 335 {
 336     struct file *file;
 337     int result;
 338
 339     if ((*low >= 0 && *high != 0) || (*low < 0 && *high != -1))
 340     {
 341         fprintf( stderr, "set_file_pointer: offset > 2Gb not supported yet\n" );
 342         set_error( STATUS_INVALID_PARAMETER );
 343         return 0;
 344     }
 345
 346     if (!(file = get_file_obj( current->process, handle, 0 )))
 347         return 0;
 348     if ((result = lseek( file->obj.fd, *low, whence )) == -1)
 349     {
 350         /* Check for seek before start of file */
 351
 352         /* also check EPERM due to SuSE7 2.2.16 lseek() EPERM kernel bug */
 353         if (((errno == EINVAL) || (errno == EPERM))
 354             && (whence != SEEK_SET) && (*low < 0))
 355             set_error( 0xc0010000 | ERROR_NEGATIVE_SEEK /* FIXME */ );
 356         else
 357             file_set_error();
 358         release_object( file );
 359         return 0;
 360     }
 361     *low = result;
 362     release_object( file );
 363     return 1;
 364 }
 365
 366 static int truncate_file( handle_t handle )
 367 {
 368     struct file *file;
 369     int result;
 370
 371     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 372         return 0;
 373     if (((result = lseek( file->obj.fd, 0, SEEK_CUR )) == -1) ||
 374         (ftruncate( file->obj.fd, result ) == -1))
 375     {
 376         file_set_error();
 377         release_object( file );
 378         return 0;
 379     }
 380     release_object( file );
 381     return 1;
 382 }
 383
 384 /* try to grow the file to the specified size */
 385 int grow_file( struct file *file, int size_high, int size_low )
 386 {
 387     struct stat st;
 388
 389     if (size_high)
 390     {
 391         set_error( STATUS_INVALID_PARAMETER );
 392         return 0;
 393     }
 394     if (fstat( file->obj.fd, &st ) == -1)
 395     {
 396         file_set_error();
 397         return 0;
 398     }
 399     if (st.st_size >= size_low) return 1;  /* already large enough */
 400     if (ftruncate( file->obj.fd, size_low ) != -1) return 1;
 401     file_set_error();
 402     return 0;
 403 }
 404
 405 static int set_file_time( handle_t handle, time_t access_time, time_t write_time )
 406 {
 407     struct file *file;
 408     struct utimbuf utimbuf;
 409
 410     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
 411         return 0;
 412     if (!file->name)
 413     {
 414         set_error( STATUS_INVALID_HANDLE );
 415         release_object( file );
 416         return 0;
 417     }
 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     struct file *file;
 454
 455     req->handle = 0;
 456     if ((file = create_file( get_req_data(req), get_req_data_size(req), req->access,
 457                              req->sharing, req->create, req->attrs )))
 458     {
 459         req->handle = alloc_handle( current->process, file, req->access, req->inherit );
 460         release_object( file );
 461     }
 462 }
 463
 464 /* allocate a file handle for a Unix fd */
 465 DECL_HANDLER(alloc_file_handle)
 466 {
 467     struct file *file;
 468     int fd;
 469
 470     req->handle = 0;
 471     if ((fd = thread_get_inflight_fd( current, req->fd )) == -1)
 472     {
 473         set_error( STATUS_INVALID_HANDLE );
 474         return;
 475     }
 476     if ((file = create_file_for_fd( fd, req->access, FILE_SHARE_READ | FILE_SHARE_WRITE, 0 )))
 477     {
 478         req->handle = alloc_handle( current->process, file, req->access, 0 );
 479         release_object( file );
 480     }
 481 }
 482
 483 /* get a Unix fd to access a file */
 484 DECL_HANDLER(get_handle_fd)
 485 {
 486     struct object *obj;
 487
 488     req->fd = -1;
 489     if ((obj = get_handle_obj( current->process, req->handle, req->access, NULL )))
 490     {
 491         int fd = get_handle_fd( current->process, req->handle, req->access );
 492         if (fd != -1) req->fd = fd;
 493         else if (!get_error())
 494         {
 495             if ((fd = obj->ops->get_fd( obj )) != -1)
 496                 send_client_fd( current->process, fd, req->handle );
 497         }
 498         release_object( obj );
 499     }
 500 }
 501
 502 /* set a file current position */
 503 DECL_HANDLER(set_file_pointer)
 504 {
 505     int high = req->high;
 506     int low  = req->low;
 507     set_file_pointer( req->handle, &low, &high, req->whence );
 508     req->new_low  = low;
 509     req->new_high = high;
 510 }
 511
 512 /* truncate (or extend) a file */
 513 DECL_HANDLER(truncate_file)
 514 {
 515     truncate_file( req->handle );
 516 }
 517
 518 /* flush a file buffers */
 519 DECL_HANDLER(flush_file)
 520 {
 521     struct object *obj;
 522
 523     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 524     {
 525         obj->ops->flush( obj );
 526         release_object( obj );
 527     }
 528 }
 529
 530 /* set a file access and modification times */
 531 DECL_HANDLER(set_file_time)
 532 {
 533     set_file_time( req->handle, req->access_time, req->write_time );
 534 }
 535
 536 /* get a file information */
 537 DECL_HANDLER(get_file_info)
 538 {
 539     struct object *obj;
 540
 541     if ((obj = get_handle_obj( current->process, req->handle, 0, NULL )))
 542     {
 543         obj->ops->get_file_info( obj, req );
 544         release_object( obj );
 545     }
 546 }
 547
 548 /* lock a region of a file */
 549 DECL_HANDLER(lock_file)
 550 {
 551     struct file *file;
 552
 553     if ((file = get_file_obj( current->process, req->handle, 0 )))
 554     {
 555         file_lock( file, req->offset_high, req->offset_low,
 556                    req->count_high, req->count_low );
 557         release_object( file );
 558     }
 559 }
 560
 561 /* unlock a region of a file */
 562 DECL_HANDLER(unlock_file)
 563 {
 564     struct file *file;
 565
 566     if ((file = get_file_obj( current->process, req->handle, 0 )))
 567     {
 568         file_unlock( file, req->offset_high, req->offset_low,
 569                      req->count_high, req->count_low );
 570         release_object( file );
 571     }
 572 }