2 * Server-side handle management
4 * Copyright (C) 1998 Alexandre Julliard
29 struct object obj
; /* object header */
30 struct process
*process
; /* process owning this table */
31 int count
; /* number of allocated entries */
32 int last
; /* last used entry */
33 int free
; /* first entry that may be free */
34 struct handle_entry
*entries
; /* handle entries */
37 static struct handle_table
*global_table
;
39 /* reserved handle access rights */
40 #define RESERVED_SHIFT 25
41 #define RESERVED_INHERIT (HANDLE_FLAG_INHERIT << RESERVED_SHIFT)
42 #define RESERVED_CLOSE_PROTECT (HANDLE_FLAG_PROTECT_FROM_CLOSE << RESERVED_SHIFT)
43 #define RESERVED_ALL (RESERVED_INHERIT | RESERVED_CLOSE_PROTECT)
45 /* global handle macros */
46 #define HANDLE_OBFUSCATOR 0x544a4def
47 #define HANDLE_IS_GLOBAL(h) (((h) ^ HANDLE_OBFUSCATOR) < 0x10000)
48 #define HANDLE_LOCAL_TO_GLOBAL(h) ((h) ^ HANDLE_OBFUSCATOR)
49 #define HANDLE_GLOBAL_TO_LOCAL(h) ((h) ^ HANDLE_OBFUSCATOR)
51 #define MIN_HANDLE_ENTRIES 32
54 /* handle to table index conversion */
56 /* handles are a multiple of 4 under NT; handle 0 is not used */
57 static int inline index_to_handle( int index
)
59 return (index
+ 1) << 2;
61 static int inline handle_to_index( int handle
)
63 return (handle
>> 2) - 1;
67 static void handle_table_dump( struct object
*obj
, int verbose
);
68 static void handle_table_destroy( struct object
*obj
);
70 static const struct object_ops handle_table_ops
=
72 sizeof(struct handle_table
), /* size */
73 handle_table_dump
, /* dump */
74 no_add_queue
, /* add_queue */
75 NULL
, /* remove_queue */
78 NULL
, /* get_poll_events */
79 NULL
, /* poll_event */
80 no_read_fd
, /* get_read_fd */
81 no_write_fd
, /* get_write_fd */
83 no_get_file_info
, /* get_file_info */
84 handle_table_destroy
/* destroy */
87 /* dump a handle table */
88 static void handle_table_dump( struct object
*obj
, int verbose
)
91 struct handle_table
*table
= (struct handle_table
*)obj
;
92 struct handle_entry
*entry
= table
->entries
;
94 assert( obj
->ops
== &handle_table_ops
);
96 fprintf( stderr
, "Handle table last=%d count=%d process=%p\n",
97 table
->last
, table
->count
, table
->process
);
99 entry
= table
->entries
;
100 for (i
= 0; i
<= table
->last
; i
++, entry
++)
102 if (!entry
->ptr
) continue;
103 fprintf( stderr
, "%9d: %p %08x ", index_to_handle(i
), entry
->ptr
, entry
->access
);
104 entry
->ptr
->ops
->dump( entry
->ptr
, 0 );
108 /* destroy a handle table */
109 static void handle_table_destroy( struct object
*obj
)
112 struct handle_table
*table
= (struct handle_table
*)obj
;
113 struct handle_entry
*entry
= table
->entries
;
115 assert( obj
->ops
== &handle_table_ops
);
117 for (i
= 0; i
<= table
->last
; i
++, entry
++)
119 struct object
*obj
= entry
->ptr
;
121 if (obj
) release_object( obj
);
123 free( table
->entries
);
126 /* allocate a new handle table */
127 struct object
*alloc_handle_table( struct process
*process
, int count
)
129 struct handle_table
*table
;
131 if (count
< MIN_HANDLE_ENTRIES
) count
= MIN_HANDLE_ENTRIES
;
132 if (!(table
= alloc_object( &handle_table_ops
, -1 )))
134 table
->process
= process
;
135 table
->count
= count
;
138 if ((table
->entries
= mem_alloc( count
* sizeof(*table
->entries
) ))) return &table
->obj
;
139 release_object( table
);
143 /* grow a handle table */
144 static int grow_handle_table( struct handle_table
*table
)
146 struct handle_entry
*new_entries
;
147 int count
= table
->count
;
149 if (count
>= INT_MAX
/ 2) return 0;
151 if (!(new_entries
= realloc( table
->entries
, count
* sizeof(struct handle_entry
) )))
153 set_error( ERROR_OUTOFMEMORY
);
156 table
->entries
= new_entries
;
157 table
->count
= count
;
161 /* allocate the first free entry in the handle table */
162 static int alloc_entry( struct handle_table
*table
, void *obj
, unsigned int access
)
164 struct handle_entry
*entry
= table
->entries
+ table
->free
;
167 for (i
= table
->free
; i
<= table
->last
; i
++, entry
++) if (!entry
->ptr
) goto found
;
168 if (i
>= table
->count
)
170 if (!grow_handle_table( table
)) return -1;
171 entry
= table
->entries
+ i
; /* the entries may have moved */
176 entry
->ptr
= grab_object( obj
);
177 entry
->access
= access
;
178 return index_to_handle(i
);
181 /* allocate a handle for an object, incrementing its refcount */
182 /* return the handle, or -1 on error */
183 int alloc_handle( struct process
*process
, void *obj
, unsigned int access
, int inherit
)
185 struct handle_table
*table
= (struct handle_table
*)process
->handles
;
188 assert( !(access
& RESERVED_ALL
) );
189 if (inherit
) access
|= RESERVED_INHERIT
;
190 return alloc_entry( table
, obj
, access
);
193 /* allocate a global handle for an object, incrementing its refcount */
194 /* return the handle, or -1 on error */
195 static int alloc_global_handle( void *obj
, unsigned int access
)
201 if (!(global_table
= (struct handle_table
*)alloc_handle_table( NULL
, 0 ))) return -1;
203 if ((handle
= alloc_entry( global_table
, obj
, access
)) != -1)
204 handle
= HANDLE_LOCAL_TO_GLOBAL(handle
);
208 /* return a handle entry, or NULL if the handle is invalid */
209 static struct handle_entry
*get_handle( struct process
*process
, int handle
)
211 struct handle_table
*table
= (struct handle_table
*)process
->handles
;
212 struct handle_entry
*entry
;
214 if (HANDLE_IS_GLOBAL(handle
))
216 handle
= HANDLE_GLOBAL_TO_LOCAL(handle
);
217 table
= global_table
;
219 if (!table
) goto error
;
220 handle
= handle_to_index( handle
);
221 if (handle
< 0) goto error
;
222 if (handle
> table
->last
) goto error
;
223 entry
= table
->entries
+ handle
;
224 if (!entry
->ptr
) goto error
;
228 set_error( ERROR_INVALID_HANDLE
);
232 /* attempt to shrink a table */
233 static void shrink_handle_table( struct handle_table
*table
)
235 struct handle_entry
*entry
= table
->entries
+ table
->last
;
236 struct handle_entry
*new_entries
;
237 int count
= table
->count
;
239 while (table
->last
>= 0)
241 if (entry
->ptr
) break;
245 if (table
->last
>= count
/ 4) return; /* no need to shrink */
246 if (count
< MIN_HANDLE_ENTRIES
* 2) return; /* too small to shrink */
248 if (!(new_entries
= realloc( table
->entries
, count
* sizeof(*new_entries
) ))) return;
249 table
->count
= count
;
250 table
->entries
= new_entries
;
253 /* copy the handle table of the parent process */
254 /* return 1 if OK, 0 on error */
255 struct object
*copy_handle_table( struct process
*process
, struct process
*parent
)
257 struct handle_table
*parent_table
= (struct handle_table
*)parent
->handles
;
258 struct handle_table
*table
;
261 assert( parent_table
);
262 assert( parent_table
->obj
.ops
== &handle_table_ops
);
264 if (!(table
= (struct handle_table
*)alloc_handle_table( process
, parent_table
->count
)))
267 if ((table
->last
= parent_table
->last
) >= 0)
269 struct handle_entry
*ptr
= table
->entries
;
270 memcpy( ptr
, parent_table
->entries
, (table
->last
+ 1) * sizeof(struct handle_entry
) );
271 for (i
= 0; i
<= table
->last
; i
++, ptr
++)
273 if (!ptr
->ptr
) continue;
274 if (ptr
->access
& RESERVED_INHERIT
) grab_object( ptr
->ptr
);
275 else ptr
->ptr
= NULL
; /* don't inherit this entry */
278 /* attempt to shrink the table */
279 shrink_handle_table( table
);
283 /* close a handle and decrement the refcount of the associated object */
284 /* return 1 if OK, 0 on error */
285 int close_handle( struct process
*process
, int handle
)
287 struct handle_table
*table
;
288 struct handle_entry
*entry
;
291 if (!(entry
= get_handle( process
, handle
))) return 0;
292 if (entry
->access
& RESERVED_CLOSE_PROTECT
)
294 set_error( ERROR_INVALID_HANDLE
);
299 table
= HANDLE_IS_GLOBAL(handle
) ? global_table
: (struct handle_table
*)process
->handles
;
300 if (entry
< table
->entries
+ table
->free
) table
->free
= entry
- table
->entries
;
301 if (entry
== table
->entries
+ table
->last
) shrink_handle_table( table
);
302 release_object( obj
);
306 /* close all the global handles */
307 void close_global_handles(void)
311 release_object( global_table
);
316 /* retrieve the object corresponding to one of the magic pseudo-handles */
317 static inline struct object
*get_magic_handle( int handle
)
321 case 0xfffffffe: /* current thread pseudo-handle */
322 return ¤t
->obj
;
323 case 0x7fffffff: /* current process pseudo-handle */
324 case 0xffffffff: /* current process pseudo-handle */
325 return (struct object
*)current
->process
;
331 /* retrieve the object corresponding to a handle, incrementing its refcount */
332 struct object
*get_handle_obj( struct process
*process
, int handle
,
333 unsigned int access
, const struct object_ops
*ops
)
335 struct handle_entry
*entry
;
338 if (!(obj
= get_magic_handle( handle
)))
340 if (!(entry
= get_handle( process
, handle
))) return NULL
;
341 if ((entry
->access
& access
) != access
)
343 set_error( ERROR_ACCESS_DENIED
);
348 if (ops
&& (obj
->ops
!= ops
))
350 set_error( ERROR_INVALID_HANDLE
); /* not the right type */
353 return grab_object( obj
);
356 /* get/set the handle reserved flags */
357 /* return the new flags (or -1 on error) */
358 static int set_handle_info( struct process
*process
, int handle
, int mask
, int flags
)
360 struct handle_entry
*entry
;
362 if (get_magic_handle( handle
))
364 /* we can retrieve but not set info for magic handles */
365 if (mask
) set_error( ERROR_ACCESS_DENIED
);
368 if (!(entry
= get_handle( process
, handle
))) return -1;
369 mask
= (mask
<< RESERVED_SHIFT
) & RESERVED_ALL
;
370 flags
= (flags
<< RESERVED_SHIFT
) & mask
;
371 entry
->access
= (entry
->access
& ~mask
) | flags
;
372 return (entry
->access
& RESERVED_ALL
) >> RESERVED_SHIFT
;
375 /* duplicate a handle */
376 int duplicate_handle( struct process
*src
, int src_handle
, struct process
*dst
,
377 unsigned int access
, int inherit
, int options
)
380 struct object
*obj
= get_handle_obj( src
, src_handle
, 0, NULL
);
383 if (options
& DUP_HANDLE_SAME_ACCESS
)
385 struct handle_entry
*entry
= get_handle( src
, src_handle
);
387 access
= entry
->access
;
388 else /* pseudo-handle, give it full access */
390 access
= STANDARD_RIGHTS_ALL
| SPECIFIC_RIGHTS_ALL
;
394 access
&= ~RESERVED_ALL
;
395 if (options
& DUP_HANDLE_MAKE_GLOBAL
)
396 res
= alloc_global_handle( obj
, access
);
398 res
= alloc_handle( dst
, obj
, access
, inherit
);
399 release_object( obj
);
403 /* open a new handle to an existing object */
404 int open_object( const WCHAR
*name
, size_t len
, const struct object_ops
*ops
,
405 unsigned int access
, int inherit
)
408 struct object
*obj
= find_object( name
, len
);
411 if (ops
&& obj
->ops
!= ops
)
412 set_error( ERROR_INVALID_HANDLE
);
414 handle
= alloc_handle( current
->process
, obj
, access
, inherit
);
415 release_object( obj
);
418 set_error( ERROR_FILE_NOT_FOUND
);
423 DECL_HANDLER(close_handle
)
425 close_handle( current
->process
, req
->handle
);
428 /* get information about a handle */
429 DECL_HANDLER(get_handle_info
)
431 req
->flags
= set_handle_info( current
->process
, req
->handle
, 0, 0 );
434 /* set a handle information */
435 DECL_HANDLER(set_handle_info
)
437 set_handle_info( current
->process
, req
->handle
, req
->mask
, req
->flags
);
440 /* duplicate a handle */
441 DECL_HANDLER(dup_handle
)
443 struct process
*src
, *dst
;
446 if ((src
= get_process_from_handle( req
->src_process
, PROCESS_DUP_HANDLE
)))
448 if (req
->options
& DUP_HANDLE_MAKE_GLOBAL
)
450 req
->handle
= duplicate_handle( src
, req
->src_handle
, NULL
,
451 req
->access
, req
->inherit
, req
->options
);
453 else if ((dst
= get_process_from_handle( req
->dst_process
, PROCESS_DUP_HANDLE
)))
455 req
->handle
= duplicate_handle( src
, req
->src_handle
, dst
,
456 req
->access
, req
->inherit
, req
->options
);
457 release_object( dst
);
459 /* close the handle no matter what happened */
460 if (req
->options
& DUP_HANDLE_CLOSE_SOURCE
)
461 close_handle( src
, req
->src_handle
);
462 release_object( src
);