Release 20040408.
[wine/multimedia.git] / server / handle.c
blobae68a7a4ef4eadc50a7187cf715de893c8f66929
1 /*
2 * Server-side handle management
4 * Copyright (C) 1998 Alexandre Julliard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include "config.h"
22 #include "wine/port.h"
24 #include <assert.h>
25 #include <limits.h>
26 #include <string.h>
27 #include <stdarg.h>
28 #include <stdio.h>
29 #include <stdlib.h>
31 #include "windef.h"
32 #include "winbase.h"
34 #include "handle.h"
35 #include "process.h"
36 #include "thread.h"
37 #include "request.h"
39 struct handle_entry
41 struct object *ptr; /* object */
42 unsigned int access; /* access rights */
43 int fd; /* file descriptor (in client process) */
46 struct handle_table
48 struct object obj; /* object header */
49 struct process *process; /* process owning this table */
50 int count; /* number of allocated entries */
51 int last; /* last used entry */
52 int free; /* first entry that may be free */
53 struct handle_entry *entries; /* handle entries */
56 static struct handle_table *global_table;
58 /* reserved handle access rights */
59 #define RESERVED_SHIFT 25
60 #define RESERVED_INHERIT (HANDLE_FLAG_INHERIT << RESERVED_SHIFT)
61 #define RESERVED_CLOSE_PROTECT (HANDLE_FLAG_PROTECT_FROM_CLOSE << RESERVED_SHIFT)
62 #define RESERVED_ALL (RESERVED_INHERIT | RESERVED_CLOSE_PROTECT)
64 #define MIN_HANDLE_ENTRIES 32
67 /* handle to table index conversion */
69 /* handles are a multiple of 4 under NT; handle 0 is not used */
70 inline static obj_handle_t index_to_handle( int index )
72 return (obj_handle_t)((index + 1) << 2);
74 inline static int handle_to_index( obj_handle_t handle )
76 return ((unsigned int)handle >> 2) - 1;
79 /* global handle conversion */
81 #define HANDLE_OBFUSCATOR 0x544a4def
83 inline static int handle_is_global( obj_handle_t handle)
85 return ((unsigned long)handle ^ HANDLE_OBFUSCATOR) < 0x10000;
87 inline static obj_handle_t handle_local_to_global( obj_handle_t handle )
89 if (!handle) return 0;
90 return (obj_handle_t)((unsigned long)handle ^ HANDLE_OBFUSCATOR);
92 inline static obj_handle_t handle_global_to_local( obj_handle_t handle )
94 return (obj_handle_t)((unsigned long)handle ^ HANDLE_OBFUSCATOR);
98 static void handle_table_dump( struct object *obj, int verbose );
99 static void handle_table_destroy( struct object *obj );
101 static const struct object_ops handle_table_ops =
103 sizeof(struct handle_table), /* size */
104 handle_table_dump, /* dump */
105 no_add_queue, /* add_queue */
106 NULL, /* remove_queue */
107 NULL, /* signaled */
108 NULL, /* satisfied */
109 no_get_fd, /* get_fd */
110 handle_table_destroy /* destroy */
113 /* dump a handle table */
114 static void handle_table_dump( struct object *obj, int verbose )
116 int i;
117 struct handle_table *table = (struct handle_table *)obj;
118 struct handle_entry *entry = table->entries;
120 assert( obj->ops == &handle_table_ops );
122 fprintf( stderr, "Handle table last=%d count=%d process=%p\n",
123 table->last, table->count, table->process );
124 if (!verbose) return;
125 entry = table->entries;
126 for (i = 0; i <= table->last; i++, entry++)
128 if (!entry->ptr) continue;
129 fprintf( stderr, "%9u: %p %08x ",
130 (unsigned int)index_to_handle(i), entry->ptr, entry->access );
131 entry->ptr->ops->dump( entry->ptr, 0 );
135 /* destroy a handle table */
136 static void handle_table_destroy( struct object *obj )
138 int i;
139 struct handle_table *table = (struct handle_table *)obj;
140 struct handle_entry *entry = table->entries;
142 assert( obj->ops == &handle_table_ops );
144 for (i = 0; i <= table->last; i++, entry++)
146 struct object *obj = entry->ptr;
147 entry->ptr = NULL;
148 if (obj) release_object( obj );
150 free( table->entries );
153 /* allocate a new handle table */
154 struct handle_table *alloc_handle_table( struct process *process, int count )
156 struct handle_table *table;
158 if (count < MIN_HANDLE_ENTRIES) count = MIN_HANDLE_ENTRIES;
159 if (!(table = alloc_object( &handle_table_ops )))
160 return NULL;
161 table->process = process;
162 table->count = count;
163 table->last = -1;
164 table->free = 0;
165 if ((table->entries = mem_alloc( count * sizeof(*table->entries) ))) return table;
166 release_object( table );
167 return NULL;
170 /* grow a handle table */
171 static int grow_handle_table( struct handle_table *table )
173 struct handle_entry *new_entries;
174 int count = table->count;
176 if (count >= INT_MAX / 2) return 0;
177 count *= 2;
178 if (!(new_entries = realloc( table->entries, count * sizeof(struct handle_entry) )))
180 set_error( STATUS_NO_MEMORY );
181 return 0;
183 table->entries = new_entries;
184 table->count = count;
185 return 1;
188 /* allocate the first free entry in the handle table */
189 static obj_handle_t alloc_entry( struct handle_table *table, void *obj, unsigned int access )
191 struct handle_entry *entry = table->entries + table->free;
192 int i;
194 for (i = table->free; i <= table->last; i++, entry++) if (!entry->ptr) goto found;
195 if (i >= table->count)
197 if (!grow_handle_table( table )) return 0;
198 entry = table->entries + i; /* the entries may have moved */
200 table->last = i;
201 found:
202 table->free = i + 1;
203 entry->ptr = grab_object( obj );
204 entry->access = access;
205 entry->fd = -1;
206 return index_to_handle(i);
209 /* allocate a handle for an object, incrementing its refcount */
210 /* return the handle, or 0 on error */
211 obj_handle_t alloc_handle( struct process *process, void *obj, unsigned int access, int inherit )
213 struct handle_table *table = process->handles;
215 assert( table );
216 assert( !(access & RESERVED_ALL) );
217 if (inherit) access |= RESERVED_INHERIT;
218 return alloc_entry( table, obj, access );
221 /* allocate a global handle for an object, incrementing its refcount */
222 /* return the handle, or 0 on error */
223 static obj_handle_t alloc_global_handle( void *obj, unsigned int access )
225 if (!global_table)
227 if (!(global_table = (struct handle_table *)alloc_handle_table( NULL, 0 )))
228 return 0;
230 return handle_local_to_global( alloc_entry( global_table, obj, access ));
233 /* return a handle entry, or NULL if the handle is invalid */
234 static struct handle_entry *get_handle( struct process *process, obj_handle_t handle )
236 struct handle_table *table = process->handles;
237 struct handle_entry *entry;
238 int index;
240 if (handle_is_global(handle))
242 handle = handle_global_to_local(handle);
243 table = global_table;
245 if (!table) goto error;
246 index = handle_to_index( handle );
247 if (index < 0) goto error;
248 if (index > table->last) goto error;
249 entry = table->entries + index;
250 if (!entry->ptr) goto error;
251 return entry;
253 error:
254 set_error( STATUS_INVALID_HANDLE );
255 return NULL;
258 /* attempt to shrink a table */
259 static void shrink_handle_table( struct handle_table *table )
261 struct handle_entry *entry = table->entries + table->last;
262 struct handle_entry *new_entries;
263 int count = table->count;
265 while (table->last >= 0)
267 if (entry->ptr) break;
268 table->last--;
269 entry--;
271 if (table->last >= count / 4) return; /* no need to shrink */
272 if (count < MIN_HANDLE_ENTRIES * 2) return; /* too small to shrink */
273 count /= 2;
274 if (!(new_entries = realloc( table->entries, count * sizeof(*new_entries) ))) return;
275 table->count = count;
276 table->entries = new_entries;
279 /* copy the handle table of the parent process */
280 /* return 1 if OK, 0 on error */
281 struct handle_table *copy_handle_table( struct process *process, struct process *parent )
283 struct handle_table *parent_table = parent->handles;
284 struct handle_table *table;
285 int i;
287 assert( parent_table );
288 assert( parent_table->obj.ops == &handle_table_ops );
290 if (!(table = (struct handle_table *)alloc_handle_table( process, parent_table->count )))
291 return NULL;
293 if ((table->last = parent_table->last) >= 0)
295 struct handle_entry *ptr = table->entries;
296 memcpy( ptr, parent_table->entries, (table->last + 1) * sizeof(struct handle_entry) );
297 for (i = 0; i <= table->last; i++, ptr++)
299 if (!ptr->ptr) continue;
300 ptr->fd = -1;
301 if (ptr->access & RESERVED_INHERIT) grab_object( ptr->ptr );
302 else ptr->ptr = NULL; /* don't inherit this entry */
305 /* attempt to shrink the table */
306 shrink_handle_table( table );
307 return table;
310 /* close a handle and decrement the refcount of the associated object */
311 /* return 1 if OK, 0 on error */
312 int close_handle( struct process *process, obj_handle_t handle, int *fd )
314 struct handle_table *table;
315 struct handle_entry *entry;
316 struct object *obj;
318 if (!(entry = get_handle( process, handle ))) return 0;
319 if (entry->access & RESERVED_CLOSE_PROTECT)
321 set_error( STATUS_INVALID_HANDLE );
322 return 0;
324 obj = entry->ptr;
325 entry->ptr = NULL;
326 if (fd) *fd = entry->fd;
327 else if (entry->fd != -1) return 1; /* silently ignore close attempt if we cannot close the fd */
328 entry->fd = -1;
329 table = handle_is_global(handle) ? global_table : process->handles;
330 if (entry < table->entries + table->free) table->free = entry - table->entries;
331 if (entry == table->entries + table->last) shrink_handle_table( table );
332 /* hack: windows seems to treat registry handles differently */
333 registry_close_handle( obj, handle );
334 release_object( obj );
335 return 1;
338 /* close all the global handles */
339 void close_global_handles(void)
341 if (global_table)
343 release_object( global_table );
344 global_table = NULL;
348 /* retrieve the object corresponding to one of the magic pseudo-handles */
349 static inline struct object *get_magic_handle( obj_handle_t handle )
351 switch((unsigned long)handle)
353 case 0xfffffffe: /* current thread pseudo-handle */
354 return &current->obj;
355 case 0x7fffffff: /* current process pseudo-handle */
356 case 0xffffffff: /* current process pseudo-handle */
357 return (struct object *)current->process;
358 default:
359 return NULL;
363 /* retrieve the object corresponding to a handle, incrementing its refcount */
364 struct object *get_handle_obj( struct process *process, obj_handle_t handle,
365 unsigned int access, const struct object_ops *ops )
367 struct handle_entry *entry;
368 struct object *obj;
370 if (!(obj = get_magic_handle( handle )))
372 if (!(entry = get_handle( process, handle ))) return NULL;
373 if ((entry->access & access) != access)
375 set_error( STATUS_ACCESS_DENIED );
376 return NULL;
378 obj = entry->ptr;
380 if (ops && (obj->ops != ops))
382 set_error( STATUS_OBJECT_TYPE_MISMATCH ); /* not the right type */
383 return NULL;
385 return grab_object( obj );
388 /* retrieve the cached fd for a given handle */
389 int get_handle_unix_fd( struct process *process, obj_handle_t handle, unsigned int access )
391 struct handle_entry *entry;
393 if (!(entry = get_handle( process, handle ))) return -1;
394 if ((entry->access & access) != access)
396 set_error( STATUS_ACCESS_DENIED );
397 return -1;
399 return entry->fd;
402 /* remove the cached fd and return it */
403 int flush_cached_fd( struct process *process, obj_handle_t handle )
405 struct handle_entry *entry = get_handle( process, handle );
406 int fd = -1;
408 if (entry)
410 fd = entry->fd;
411 entry->fd = -1;
413 return fd;
416 /* find the first inherited handle of the given type */
417 /* this is needed for window stations and desktops (don't ask...) */
418 obj_handle_t find_inherited_handle( struct process *process, const struct object_ops *ops )
420 struct handle_table *table = process->handles;
421 struct handle_entry *ptr;
422 int i;
424 if (!table) return 0;
426 for (i = 0, ptr = table->entries; i <= table->last; i++, ptr++)
428 if (!ptr->ptr) continue;
429 if (ptr->ptr->ops != ops) continue;
430 if (ptr->access & RESERVED_INHERIT) return index_to_handle(i);
432 return 0;
435 /* get/set the handle reserved flags */
436 /* return the old flags (or -1 on error) */
437 int set_handle_info( struct process *process, obj_handle_t handle, int mask, int flags, int *fd )
439 struct handle_entry *entry;
440 unsigned int old_access;
442 if (get_magic_handle( handle ))
444 /* we can retrieve but not set info for magic handles */
445 if (mask) set_error( STATUS_ACCESS_DENIED );
446 return 0;
448 if (!(entry = get_handle( process, handle ))) return -1;
449 old_access = entry->access;
450 mask = (mask << RESERVED_SHIFT) & RESERVED_ALL;
451 flags = (flags << RESERVED_SHIFT) & mask;
452 entry->access = (entry->access & ~mask) | flags;
453 /* if no current fd set it, otherwise return current fd */
454 if (entry->fd == -1) entry->fd = *fd;
455 *fd = entry->fd;
456 return (old_access & RESERVED_ALL) >> RESERVED_SHIFT;
459 /* duplicate a handle */
460 obj_handle_t duplicate_handle( struct process *src, obj_handle_t src_handle, struct process *dst,
461 unsigned int access, int inherit, int options )
463 obj_handle_t res;
464 struct object *obj = get_handle_obj( src, src_handle, 0, NULL );
466 if (!obj) return 0;
467 if (options & DUP_HANDLE_SAME_ACCESS)
469 struct handle_entry *entry = get_handle( src, src_handle );
470 if (entry)
471 access = entry->access;
472 else /* pseudo-handle, give it full access */
474 access = STANDARD_RIGHTS_ALL | SPECIFIC_RIGHTS_ALL;
475 clear_error();
478 access &= ~RESERVED_ALL;
479 if (options & DUP_HANDLE_MAKE_GLOBAL)
480 res = alloc_global_handle( obj, access );
481 else
482 res = alloc_handle( dst, obj, access, inherit );
483 release_object( obj );
484 return res;
487 /* open a new handle to an existing object */
488 obj_handle_t open_object( const struct namespace *namespace, const WCHAR *name, size_t len,
489 const struct object_ops *ops, unsigned int access, int inherit )
491 obj_handle_t handle = 0;
492 struct object *obj = find_object( namespace, name, len );
493 if (obj)
495 if (ops && obj->ops != ops)
496 set_error( STATUS_OBJECT_TYPE_MISMATCH );
497 else
498 handle = alloc_handle( current->process, obj, access, inherit );
499 release_object( obj );
501 else
502 set_error( STATUS_OBJECT_NAME_NOT_FOUND );
503 return handle;
506 /* return the size of the handle table of a given process */
507 unsigned int get_handle_table_count( struct process *process )
509 return process->handles->count;
512 /* close a handle */
513 DECL_HANDLER(close_handle)
515 close_handle( current->process, req->handle, &reply->fd );
518 /* set a handle information */
519 DECL_HANDLER(set_handle_info)
521 int fd = req->fd;
523 if (handle_is_global(req->handle)) fd = -1; /* no fd cache for global handles */
524 reply->old_flags = set_handle_info( current->process, req->handle,
525 req->mask, req->flags, &fd );
526 reply->cur_fd = fd;
529 /* duplicate a handle */
530 DECL_HANDLER(dup_handle)
532 struct process *src, *dst;
534 reply->handle = 0;
535 reply->fd = -1;
536 if ((src = get_process_from_handle( req->src_process, PROCESS_DUP_HANDLE )))
538 if (req->options & DUP_HANDLE_MAKE_GLOBAL)
540 reply->handle = duplicate_handle( src, req->src_handle, NULL,
541 req->access, req->inherit, req->options );
543 else if ((dst = get_process_from_handle( req->dst_process, PROCESS_DUP_HANDLE )))
545 reply->handle = duplicate_handle( src, req->src_handle, dst,
546 req->access, req->inherit, req->options );
547 release_object( dst );
549 /* close the handle no matter what happened */
550 if (req->options & DUP_HANDLE_CLOSE_SOURCE)
552 if (src == current->process) close_handle( src, req->src_handle, &reply->fd );
553 else close_handle( src, req->src_handle, NULL );
555 release_object( src );