server/object.c

   1 /*
   2  * Server-side objects
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  *
   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.
  10  *
  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.
  15  *
  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
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <limits.h>
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <stdarg.h>
  31
  32 #include "ntstatus.h"
  33 #define WIN32_NO_STATUS
  34 #include "winternl.h"
  35
  36 #include "file.h"
  37 #include "thread.h"
  38 #include "unicode.h"
  39
  40
  41 struct object_name
  42 {
  43     struct list         entry;           /* entry in the hash list */
  44     struct object      *obj;             /* object owning this name */
  45     struct object      *parent;          /* parent object */
  46     size_t              len;             /* name length in bytes */
  47     WCHAR               name[1];
  48 };
  49
  50 struct namespace
  51 {
  52     unsigned int        hash_size;       /* size of hash table */
  53     struct list         names[1];        /* array of hash entry lists */
  54 };
  55
  56
  57 #ifdef DEBUG_OBJECTS
  58 static struct list object_list = LIST_INIT(object_list);
  59 static struct list static_object_list = LIST_INIT(static_object_list);
  60
  61 void dump_objects(void)
  62 {
  63     struct list *p;
  64
  65     LIST_FOR_EACH( p, &static_object_list )
  66     {
  67         struct object *ptr = LIST_ENTRY( p, struct object, obj_list );
  68         fprintf( stderr, "%p:%d: ", ptr, ptr->refcount );
  69         ptr->ops->dump( ptr, 1 );
  70     }
  71     LIST_FOR_EACH( p, &object_list )
  72     {
  73         struct object *ptr = LIST_ENTRY( p, struct object, obj_list );
  74         fprintf( stderr, "%p:%d: ", ptr, ptr->refcount );
  75         ptr->ops->dump( ptr, 1 );
  76     }
  77 }
  78
  79 void close_objects(void)
  80 {
  81     struct list *ptr;
  82
  83     /* release the static objects */
  84     while ((ptr = list_head( &static_object_list )))
  85     {
  86         struct object *obj = LIST_ENTRY( ptr, struct object, obj_list );
  87         /* move it back to the standard list before freeing */
  88         list_remove( &obj->obj_list );
  89         list_add_head( &object_list, &obj->obj_list );
  90         release_object( obj );
  91     }
  92
  93     dump_objects();  /* dump any remaining objects */
  94 }
  95
  96 #endif  /* DEBUG_OBJECTS */
  97
  98 /*****************************************************************/
  99
 100 /* malloc replacement */
 101 void *mem_alloc( size_t size )
 102 {
 103     void *ptr = malloc( size );
 104     if (ptr) memset( ptr, 0x55, size );
 105     else set_error( STATUS_NO_MEMORY );
 106     return ptr;
 107 }
 108
 109 /* duplicate a block of memory */
 110 void *memdup( const void *data, size_t len )
 111 {
 112     void *ptr = malloc( len );
 113     if (ptr) memcpy( ptr, data, len );
 114     else set_error( STATUS_NO_MEMORY );
 115     return ptr;
 116 }
 117
 118
 119 /*****************************************************************/
 120
 121 static int get_name_hash( const struct namespace *namespace, const WCHAR *name, size_t len )
 122 {
 123     WCHAR hash = 0;
 124     len /= sizeof(WCHAR);
 125     while (len--) hash ^= tolowerW(*name++);
 126     return hash % namespace->hash_size;
 127 }
 128
 129 /* allocate a name for an object */
 130 static struct object_name *alloc_name( const struct unicode_str *name )
 131 {
 132     struct object_name *ptr;
 133
 134     if ((ptr = mem_alloc( sizeof(*ptr) + name->len - sizeof(ptr->name) )))
 135     {
 136         ptr->len = name->len;
 137         ptr->parent = NULL;
 138         memcpy( ptr->name, name->str, name->len );
 139     }
 140     return ptr;
 141 }
 142
 143 /* free the name of an object */
 144 static void free_name( struct object *obj )
 145 {
 146     struct object_name *ptr = obj->name;
 147     list_remove( &ptr->entry );
 148     if (ptr->parent) release_object( ptr->parent );
 149     free( ptr );
 150 }
 151
 152 /* set the name of an existing object */
 153 static void set_object_name( struct namespace *namespace,
 154                              struct object *obj, struct object_name *ptr )
 155 {
 156     int hash = get_name_hash( namespace, ptr->name, ptr->len );
 157
 158     list_add_head( &namespace->names[hash], &ptr->entry );
 159     ptr->obj = obj;
 160     obj->name = ptr;
 161 }
 162
 163 /* get the name of an existing object */
 164 const WCHAR *get_object_name( struct object *obj, size_t *len )
 165 {
 166     struct object_name *ptr = obj->name;
 167     if (!ptr) return NULL;
 168     *len = ptr->len;
 169     return ptr->name;
 170 }
 171
 172 /* allocate and initialize an object */
 173 void *alloc_object( const struct object_ops *ops )
 174 {
 175     struct object *obj = mem_alloc( ops->size );
 176     if (obj)
 177     {
 178         obj->refcount = 1;
 179         obj->ops      = ops;
 180         obj->name     = NULL;
 181         list_init( &obj->wait_queue );
 182 #ifdef DEBUG_OBJECTS
 183         list_add_head( &object_list, &obj->obj_list );
 184 #endif
 185         return obj;
 186     }
 187     return NULL;
 188 }
 189
 190 void *create_object( struct namespace *namespace, const struct object_ops *ops,
 191                      const struct unicode_str *name, struct object *parent )
 192 {
 193     struct object *obj;
 194     struct object_name *name_ptr;
 195
 196     if (!(name_ptr = alloc_name( name ))) return NULL;
 197     if ((obj = alloc_object( ops )))
 198     {
 199         set_object_name( namespace, obj, name_ptr );
 200         if (parent) name_ptr->parent = grab_object( parent );
 201     }
 202     else
 203         free( name_ptr );
 204     return obj;
 205 }
 206
 207 void *create_named_object( struct namespace *namespace, const struct object_ops *ops,
 208                            const struct unicode_str *name, unsigned int attributes )
 209 {
 210     struct object *obj;
 211
 212     if (!name || !name->len) return alloc_object( ops );
 213
 214     if ((obj = find_object( namespace, name, attributes )))
 215     {
 216         if (attributes & OBJ_OPENIF && obj->ops == ops)
 217             set_error( STATUS_OBJECT_NAME_EXISTS );
 218         else
 219         {
 220             release_object( obj );
 221             obj = NULL;
 222             if (attributes & OBJ_OPENIF)
 223                 set_error( STATUS_OBJECT_TYPE_MISMATCH );
 224             else
 225                 set_error( STATUS_OBJECT_NAME_COLLISION );
 226         }
 227         return obj;
 228     }
 229     if ((obj = create_object( namespace, ops, name, NULL ))) clear_error();
 230     return obj;
 231 }
 232
 233 /* dump the name of an object to stderr */
 234 void dump_object_name( struct object *obj )
 235 {
 236     if (!obj->name) fprintf( stderr, "name=\"\"" );
 237     else
 238     {
 239         fprintf( stderr, "name=L\"" );
 240         dump_strW( obj->name->name, obj->name->len/sizeof(WCHAR), stderr, "\"\"" );
 241         fputc( '\"', stderr );
 242     }
 243 }
 244
 245 /* unlink a named object from its namespace, without freeing the object itself */
 246 void unlink_named_object( struct object *obj )
 247 {
 248     if (obj->name) free_name( obj );
 249     obj->name = NULL;
 250 }
 251
 252 /* mark an object as being stored statically, i.e. only released at shutdown */
 253 void make_object_static( struct object *obj )
 254 {
 255 #ifdef DEBUG_OBJECTS
 256     list_remove( &obj->obj_list );
 257     list_add_head( &static_object_list, &obj->obj_list );
 258 #endif
 259 }
 260
 261 /* grab an object (i.e. increment its refcount) and return the object */
 262 struct object *grab_object( void *ptr )
 263 {
 264     struct object *obj = (struct object *)ptr;
 265     assert( obj->refcount < INT_MAX );
 266     obj->refcount++;
 267     return obj;
 268 }
 269
 270 /* release an object (i.e. decrement its refcount) */
 271 void release_object( void *ptr )
 272 {
 273     struct object *obj = (struct object *)ptr;
 274     assert( obj->refcount );
 275     if (!--obj->refcount)
 276     {
 277         /* if the refcount is 0, nobody can be in the wait queue */
 278         assert( list_empty( &obj->wait_queue ));
 279         obj->ops->destroy( obj );
 280         if (obj->name) free_name( obj );
 281 #ifdef DEBUG_OBJECTS
 282         list_remove( &obj->obj_list );
 283         memset( obj, 0xaa, obj->ops->size );
 284 #endif
 285         free( obj );
 286     }
 287 }
 288
 289 /* find an object by its name; the refcount is incremented */
 290 struct object *find_object( const struct namespace *namespace, const struct unicode_str *name,
 291                             unsigned int attributes )
 292 {
 293     const struct list *list, *p;
 294
 295     if (!name || !name->len) return NULL;
 296
 297     list = &namespace->names[ get_name_hash( namespace, name->str, name->len ) ];
 298     LIST_FOR_EACH( p, list )
 299     {
 300         const struct object_name *ptr = LIST_ENTRY( p, const struct object_name, entry );
 301         if (ptr->len != name->len) continue;
 302         if (attributes & OBJ_CASE_INSENSITIVE)
 303         {
 304             if (!strncmpiW( ptr->name, name->str, name->len/sizeof(WCHAR) ))
 305                 return grab_object( ptr->obj );
 306         }
 307         else
 308         {
 309             if (!memcmp( ptr->name, name->str, name->len ))
 310                 return grab_object( ptr->obj );
 311         }
 312     }
 313     return NULL;
 314 }
 315
 316 /* allocate a namespace */
 317 struct namespace *create_namespace( unsigned int hash_size )
 318 {
 319     struct namespace *namespace;
 320     unsigned int i;
 321
 322     namespace = mem_alloc( sizeof(*namespace) + (hash_size - 1) * sizeof(namespace->names[0]) );
 323     if (namespace)
 324     {
 325         namespace->hash_size      = hash_size;
 326         for (i = 0; i < hash_size; i++) list_init( &namespace->names[i] );
 327     }
 328     return namespace;
 329 }
 330
 331 /* functions for unimplemented/default object operations */
 332
 333 int no_add_queue( struct object *obj, struct wait_queue_entry *entry )
 334 {
 335     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 336     return 0;
 337 }
 338
 339 int no_satisfied( struct object *obj, struct thread *thread )
 340 {
 341     return 0;  /* not abandoned */
 342 }
 343
 344 int no_signal( struct object *obj, unsigned int access )
 345 {
 346     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 347     return 0;
 348 }
 349
 350 struct fd *no_get_fd( struct object *obj )
 351 {
 352     set_error( STATUS_OBJECT_TYPE_MISMATCH );
 353     return NULL;
 354 }
 355
 356 unsigned int no_map_access( struct object *obj, unsigned int access )
 357 {
 358     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ;
 359     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 360     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 361     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_ALL;
 362     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 363 }
 364
 365 struct object *no_lookup_name( struct object *obj, struct unicode_str *name,
 366                                unsigned int attr )
 367 {
 368     return NULL;
 369 }
 370
 371 int no_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
 372 {
 373     return 1;  /* ok to close */
 374 }
 375
 376 void no_destroy( struct object *obj )
 377 {
 378 }