Sweden-Number/server/handle.c

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/*
* Server-side handle management
*
* Copyright (C) 1998 Alexandre Julliard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include "wine/port.h"
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
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#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winternl.h"
#include "handle.h"
#include "process.h"
#include "thread.h"
#include "security.h"
#include "request.h"
struct handle_entry
{
struct object *ptr; /* object */
unsigned int access; /* access rights */
};
struct handle_table
{
struct object obj; /* object header */
struct process *process; /* process owning this table */
int count; /* number of allocated entries */
int last; /* last used entry */
int free; /* first entry that may be free */
struct handle_entry *entries; /* handle entries */
};
static struct handle_table *global_table;
/* reserved handle access rights */
#define RESERVED_SHIFT 26
#define RESERVED_INHERIT (HANDLE_FLAG_INHERIT << RESERVED_SHIFT)
#define RESERVED_CLOSE_PROTECT (HANDLE_FLAG_PROTECT_FROM_CLOSE << RESERVED_SHIFT)
#define RESERVED_ALL (RESERVED_INHERIT | RESERVED_CLOSE_PROTECT)
#define MIN_HANDLE_ENTRIES 32
#define MAX_HANDLE_ENTRIES 0x00ffffff
/* handle to table index conversion */
/* handles are a multiple of 4 under NT; handle 0 is not used */
static inline obj_handle_t index_to_handle( int index )
{
return (obj_handle_t)((index + 1) << 2);
}
static inline int handle_to_index( obj_handle_t handle )
{
return (handle >> 2) - 1;
}
/* global handle conversion */
#define HANDLE_OBFUSCATOR 0x544a4def
static inline int handle_is_global( obj_handle_t handle)
{
return (handle ^ HANDLE_OBFUSCATOR) <= (MAX_HANDLE_ENTRIES << 2);
}
static inline obj_handle_t handle_local_to_global( obj_handle_t handle )
{
if (!handle) return 0;
return handle ^ HANDLE_OBFUSCATOR;
}
static inline obj_handle_t handle_global_to_local( obj_handle_t handle )
{
return handle ^ HANDLE_OBFUSCATOR;
}
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/* grab an object and increment its handle count */
static struct object *grab_object_for_handle( struct object *obj )
{
obj->handle_count++;
return grab_object( obj );
}
/* release an object and decrement its handle count */
static void release_object_from_handle( struct object *obj )
{
assert( obj->handle_count );
obj->handle_count--;
release_object( obj );
}
static void handle_table_dump( struct object *obj, int verbose );
static void handle_table_destroy( struct object *obj );
static const struct object_ops handle_table_ops =
{
sizeof(struct handle_table), /* size */
handle_table_dump, /* dump */
no_get_type, /* get_type */
no_add_queue, /* add_queue */
NULL, /* remove_queue */
NULL, /* signaled */
NULL, /* satisfied */
no_signal, /* signal */
no_get_fd, /* get_fd */
no_map_access, /* map_access */
default_get_sd, /* get_sd */
default_set_sd, /* set_sd */
no_lookup_name, /* lookup_name */
no_open_file, /* open_file */
no_close_handle, /* close_handle */
handle_table_destroy /* destroy */
};
/* dump a handle table */
static void handle_table_dump( struct object *obj, int verbose )
{
int i;
struct handle_table *table = (struct handle_table *)obj;
struct handle_entry *entry;
assert( obj->ops == &handle_table_ops );
fprintf( stderr, "Handle table last=%d count=%d process=%p\n",
table->last, table->count, table->process );
if (!verbose) return;
entry = table->entries;
for (i = 0; i <= table->last; i++, entry++)
{
if (!entry->ptr) continue;
fprintf( stderr, " %04x: %p %08x ",
index_to_handle(i), entry->ptr, entry->access );
entry->ptr->ops->dump( entry->ptr, 0 );
}
}
/* destroy a handle table */
static void handle_table_destroy( struct object *obj )
{
int i;
struct handle_table *table = (struct handle_table *)obj;
struct handle_entry *entry;
assert( obj->ops == &handle_table_ops );
/* first notify all objects that handles are being closed */
if (table->process)
{
for (i = 0, entry = table->entries; i <= table->last; i++, entry++)
{
struct object *obj = entry->ptr;
if (obj) obj->ops->close_handle( obj, table->process, index_to_handle(i) );
}
}
for (i = 0, entry = table->entries; i <= table->last; i++, entry++)
{
struct object *obj = entry->ptr;
entry->ptr = NULL;
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if (obj) release_object_from_handle( obj );
}
free( table->entries );
}
/* close all the process handles and free the handle table */
void close_process_handles( struct process *process )
{
struct handle_table *table = process->handles;
process->handles = NULL;
if (table) release_object( table );
}
/* allocate a new handle table */
struct handle_table *alloc_handle_table( struct process *process, int count )
{
struct handle_table *table;
if (count < MIN_HANDLE_ENTRIES) count = MIN_HANDLE_ENTRIES;
if (!(table = alloc_object( &handle_table_ops )))
return NULL;
table->process = process;
table->count = count;
table->last = -1;
table->free = 0;
if ((table->entries = mem_alloc( count * sizeof(*table->entries) ))) return table;
release_object( table );
return NULL;
}
/* grow a handle table */
static int grow_handle_table( struct handle_table *table )
{
struct handle_entry *new_entries;
int count = min( table->count * 2, MAX_HANDLE_ENTRIES );
if (count == table->count ||
!(new_entries = realloc( table->entries, count * sizeof(struct handle_entry) )))
{
set_error( STATUS_INSUFFICIENT_RESOURCES );
return 0;
}
table->entries = new_entries;
table->count = count;
return 1;
}
/* allocate the first free entry in the handle table */
static obj_handle_t alloc_entry( struct handle_table *table, void *obj, unsigned int access )
{
struct handle_entry *entry = table->entries + table->free;
int i;
for (i = table->free; i <= table->last; i++, entry++) if (!entry->ptr) goto found;
if (i >= table->count)
{
if (!grow_handle_table( table )) return 0;
entry = table->entries + i; /* the entries may have moved */
}
table->last = i;
found:
table->free = i + 1;
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entry->ptr = grab_object_for_handle( obj );
entry->access = access;
return index_to_handle(i);
}
/* allocate a handle for an object, incrementing its refcount */
static obj_handle_t alloc_handle_entry( struct process *process, void *ptr,
unsigned int access, unsigned int attr )
{
struct object *obj = ptr;
assert( !(access & RESERVED_ALL) );
if (attr & OBJ_INHERIT) access |= RESERVED_INHERIT;
if (!process->handles)
{
set_error( STATUS_PROCESS_IS_TERMINATING );
return 0;
}
return alloc_entry( process->handles, obj, access );
}
/* allocate a handle for an object, incrementing its refcount */
/* return the handle, or 0 on error */
obj_handle_t alloc_handle_no_access_check( struct process *process, void *ptr, unsigned int access, unsigned int attr )
{
struct object *obj = ptr;
access = obj->ops->map_access( obj, access ) & ~RESERVED_ALL;
return alloc_handle_entry( process, ptr, access, attr );
}
/* allocate a handle for an object, checking the dacl allows the process to */
/* access it and incrementing its refcount */
/* return the handle, or 0 on error */
obj_handle_t alloc_handle( struct process *process, void *ptr, unsigned int access, unsigned int attr )
{
struct object *obj = ptr;
access = obj->ops->map_access( obj, access ) & ~RESERVED_ALL;
if (access && !check_object_access( obj, &access )) return 0;
return alloc_handle_entry( process, ptr, access, attr );
}
/* allocate a global handle for an object, incrementing its refcount */
/* return the handle, or 0 on error */
static obj_handle_t alloc_global_handle_no_access_check( void *obj, unsigned int access )
{
if (!global_table)
{
if (!(global_table = alloc_handle_table( NULL, 0 )))
return 0;
make_object_static( &global_table->obj );
}
return handle_local_to_global( alloc_entry( global_table, obj, access ));
}
/* allocate a global handle for an object, checking the dacl allows the */
/* process to access it and incrementing its refcount and incrementing its refcount */
/* return the handle, or 0 on error */
static obj_handle_t alloc_global_handle( void *obj, unsigned int access )
{
if (access && !check_object_access( obj, &access )) return 0;
return alloc_global_handle_no_access_check( obj, access );
}
/* return a handle entry, or NULL if the handle is invalid */
static struct handle_entry *get_handle( struct process *process, obj_handle_t handle )
{
struct handle_table *table = process->handles;
struct handle_entry *entry;
int index;
if (handle_is_global(handle))
{
handle = handle_global_to_local(handle);
table = global_table;
}
if (!table) return NULL;
index = handle_to_index( handle );
if (index < 0) return NULL;
if (index > table->last) return NULL;
entry = table->entries + index;
if (!entry->ptr) return NULL;
return entry;
}
/* attempt to shrink a table */
static void shrink_handle_table( struct handle_table *table )
{
struct handle_entry *entry = table->entries + table->last;
struct handle_entry *new_entries;
int count = table->count;
while (table->last >= 0)
{
if (entry->ptr) break;
table->last--;
entry--;
}
if (table->last >= count / 4) return; /* no need to shrink */
if (count < MIN_HANDLE_ENTRIES * 2) return; /* too small to shrink */
count /= 2;
if (!(new_entries = realloc( table->entries, count * sizeof(*new_entries) ))) return;
table->count = count;
table->entries = new_entries;
}
/* copy the handle table of the parent process */
/* return 1 if OK, 0 on error */
struct handle_table *copy_handle_table( struct process *process, struct process *parent )
{
struct handle_table *parent_table = parent->handles;
struct handle_table *table;
int i;
assert( parent_table );
assert( parent_table->obj.ops == &handle_table_ops );
if (!(table = alloc_handle_table( process, parent_table->count )))
return NULL;
if ((table->last = parent_table->last) >= 0)
{
struct handle_entry *ptr = table->entries;
memcpy( ptr, parent_table->entries, (table->last + 1) * sizeof(struct handle_entry) );
for (i = 0; i <= table->last; i++, ptr++)
{
if (!ptr->ptr) continue;
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if (ptr->access & RESERVED_INHERIT) grab_object_for_handle( ptr->ptr );
else ptr->ptr = NULL; /* don't inherit this entry */
}
}
/* attempt to shrink the table */
shrink_handle_table( table );
return table;
}
/* close a handle and decrement the refcount of the associated object */
unsigned int close_handle( struct process *process, obj_handle_t handle )
{
struct handle_table *table;
struct handle_entry *entry;
struct object *obj;
if (!(entry = get_handle( process, handle ))) return STATUS_INVALID_HANDLE;
if (entry->access & RESERVED_CLOSE_PROTECT) return STATUS_HANDLE_NOT_CLOSABLE;
obj = entry->ptr;
if (!obj->ops->close_handle( obj, process, handle )) return STATUS_HANDLE_NOT_CLOSABLE;
entry->ptr = NULL;
table = handle_is_global(handle) ? global_table : process->handles;
if (entry < table->entries + table->free) table->free = entry - table->entries;
if (entry == table->entries + table->last) shrink_handle_table( table );
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release_object_from_handle( obj );
return STATUS_SUCCESS;
}
/* retrieve the object corresponding to one of the magic pseudo-handles */
static inline struct object *get_magic_handle( obj_handle_t handle )
{
switch(handle)
{
case 0xfffffffe: /* current thread pseudo-handle */
return &current->obj;
case 0x7fffffff: /* current process pseudo-handle */
case 0xffffffff: /* current process pseudo-handle */
return (struct object *)current->process;
default:
return NULL;
}
}
/* retrieve the object corresponding to a handle, incrementing its refcount */
struct object *get_handle_obj( struct process *process, obj_handle_t handle,
unsigned int access, const struct object_ops *ops )
{
struct handle_entry *entry;
struct object *obj;
if (!(obj = get_magic_handle( handle )))
{
if (!(entry = get_handle( process, handle )))
{
set_error( STATUS_INVALID_HANDLE );
return NULL;
}
obj = entry->ptr;
if (ops && (obj->ops != ops))
{
set_error( STATUS_OBJECT_TYPE_MISMATCH ); /* not the right type */
return NULL;
}
if ((entry->access & access) != access)
{
set_error( STATUS_ACCESS_DENIED );
return NULL;
}
}
else if (ops && (obj->ops != ops))
{
set_error( STATUS_OBJECT_TYPE_MISMATCH ); /* not the right type */
return NULL;
}
return grab_object( obj );
}
/* retrieve the access rights of a given handle */
unsigned int get_handle_access( struct process *process, obj_handle_t handle )
{
struct handle_entry *entry;
if (get_magic_handle( handle )) return ~RESERVED_ALL; /* magic handles have all access rights */
if (!(entry = get_handle( process, handle ))) return 0;
return entry->access & ~RESERVED_ALL;
}
/* find the first inherited handle of the given type */
/* this is needed for window stations and desktops (don't ask...) */
obj_handle_t find_inherited_handle( struct process *process, const struct object_ops *ops )
{
struct handle_table *table = process->handles;
struct handle_entry *ptr;
int i;
if (!table) return 0;
for (i = 0, ptr = table->entries; i <= table->last; i++, ptr++)
{
if (!ptr->ptr) continue;
if (ptr->ptr->ops != ops) continue;
if (ptr->access & RESERVED_INHERIT) return index_to_handle(i);
}
return 0;
}
/* enumerate handles of a given type */
/* this is needed for window stations and desktops */
obj_handle_t enumerate_handles( struct process *process, const struct object_ops *ops,
unsigned int *index )
{
struct handle_table *table = process->handles;
unsigned int i;
struct handle_entry *entry;
if (!table) return 0;
for (i = *index, entry = &table->entries[i]; i <= table->last; i++, entry++)
{
if (!entry->ptr) continue;
if (entry->ptr->ops != ops) continue;
*index = i + 1;
return index_to_handle(i);
}
return 0;
}
/* get/set the handle reserved flags */
/* return the old flags (or -1 on error) */
static int set_handle_flags( struct process *process, obj_handle_t handle, int mask, int flags )
{
struct handle_entry *entry;
unsigned int old_access;
if (get_magic_handle( handle ))
{
/* we can retrieve but not set info for magic handles */
if (mask) set_error( STATUS_ACCESS_DENIED );
return 0;
}
if (!(entry = get_handle( process, handle )))
{
set_error( STATUS_INVALID_HANDLE );
return -1;
}
old_access = entry->access;
mask = (mask << RESERVED_SHIFT) & RESERVED_ALL;
flags = (flags << RESERVED_SHIFT) & mask;
entry->access = (entry->access & ~mask) | flags;
return (old_access & RESERVED_ALL) >> RESERVED_SHIFT;
}
/* duplicate a handle */
obj_handle_t duplicate_handle( struct process *src, obj_handle_t src_handle, struct process *dst,
unsigned int access, unsigned int attr, unsigned int options )
{
obj_handle_t res;
struct handle_entry *entry;
unsigned int src_access;
struct object *obj = get_handle_obj( src, src_handle, 0, NULL );
if (!obj) return 0;
if ((entry = get_handle( src, src_handle )))
src_access = entry->access;
else /* pseudo-handle, give it full access */
src_access = obj->ops->map_access( obj, GENERIC_ALL );
src_access &= ~RESERVED_ALL;
if (options & DUP_HANDLE_SAME_ACCESS)
access = src_access;
else
access = obj->ops->map_access( obj, access ) & ~RESERVED_ALL;
/* asking for the more access rights than src_access? */
if (access & ~src_access)
{
if (options & DUP_HANDLE_MAKE_GLOBAL)
res = alloc_global_handle( obj, access );
else
res = alloc_handle( dst, obj, access, attr );
}
else
{
if (options & DUP_HANDLE_MAKE_GLOBAL)
res = alloc_global_handle_no_access_check( obj, access );
else if ((options & DUP_HANDLE_CLOSE_SOURCE) && src == dst &&
entry && !(entry->access & RESERVED_CLOSE_PROTECT))
{
if (attr & OBJ_INHERIT) access |= RESERVED_INHERIT;
entry->access = access;
res = src_handle;
}
else
res = alloc_handle_entry( dst, obj, access, attr );
}
release_object( obj );
return res;
}
/* open a new handle to an existing object */
obj_handle_t open_object( const struct namespace *namespace, const struct unicode_str *name,
const struct object_ops *ops, unsigned int access, unsigned int attr )
{
obj_handle_t handle = 0;
struct object *obj = find_object( namespace, name, attr );
if (obj)
{
if (ops && obj->ops != ops)
set_error( STATUS_OBJECT_TYPE_MISMATCH );
else
handle = alloc_handle( current->process, obj, access, attr );
release_object( obj );
}
else
set_error( STATUS_OBJECT_NAME_NOT_FOUND );
return handle;
}
/* return the size of the handle table of a given process */
unsigned int get_handle_table_count( struct process *process )
{
if (!process->handles) return 0;
return process->handles->count;
}
/* close a handle */
DECL_HANDLER(close_handle)
{
unsigned int err = close_handle( current->process, req->handle );
set_error( err );
}
/* set a handle information */
DECL_HANDLER(set_handle_info)
{
reply->old_flags = set_handle_flags( current->process, req->handle, req->mask, req->flags );
}
/* duplicate a handle */
DECL_HANDLER(dup_handle)
{
struct process *src, *dst = NULL;
reply->handle = 0;
if ((src = get_process_from_handle( req->src_process, PROCESS_DUP_HANDLE )))
{
if (req->options & DUP_HANDLE_MAKE_GLOBAL)
{
reply->handle = duplicate_handle( src, req->src_handle, NULL,
req->access, req->attributes, req->options );
}
else if ((dst = get_process_from_handle( req->dst_process, PROCESS_DUP_HANDLE )))
{
reply->handle = duplicate_handle( src, req->src_handle, dst,
req->access, req->attributes, req->options );
release_object( dst );
}
/* close the handle no matter what happened */
if ((req->options & DUP_HANDLE_CLOSE_SOURCE) && (src != dst || req->src_handle != reply->handle))
reply->closed = !close_handle( src, req->src_handle );
reply->self = (src == current->process);
release_object( src );
}
}
DECL_HANDLER(get_object_info)
{
struct object *obj;
WCHAR *name;
if (!(obj = get_handle_obj( current->process, req->handle, 0, NULL ))) return;
reply->access = get_handle_access( current->process, req->handle );
reply->ref_count = obj->refcount;
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reply->handle_count = obj->handle_count;
if ((name = get_object_full_name( obj, &reply->total )))
set_reply_data_ptr( name, min( reply->total, get_reply_max_size() ));
release_object( obj );
}
DECL_HANDLER(set_security_object)
{
data_size_t sd_size = get_req_data_size();
const struct security_descriptor *sd = get_req_data();
struct object *obj;
unsigned int access = 0;
if (!sd_is_valid( sd, sd_size ))
{
set_error( STATUS_ACCESS_VIOLATION );
return;
}
if (req->security_info & OWNER_SECURITY_INFORMATION ||
req->security_info & GROUP_SECURITY_INFORMATION)
access |= WRITE_OWNER;
if (req->security_info & SACL_SECURITY_INFORMATION)
access |= ACCESS_SYSTEM_SECURITY;
if (req->security_info & DACL_SECURITY_INFORMATION)
access |= WRITE_DAC;
if (!(obj = get_handle_obj( current->process, req->handle, access, NULL ))) return;
obj->ops->set_sd( obj, sd, req->security_info );
release_object( obj );
}
DECL_HANDLER(get_security_object)
{
const struct security_descriptor *sd;
struct object *obj;
unsigned int access = READ_CONTROL;
struct security_descriptor req_sd;
int present;
const SID *owner, *group;
const ACL *sacl, *dacl;
if (req->security_info & SACL_SECURITY_INFORMATION)
access |= ACCESS_SYSTEM_SECURITY;
if (!(obj = get_handle_obj( current->process, req->handle, access, NULL ))) return;
sd = obj->ops->get_sd( obj );
if (sd)
{
req_sd.control = sd->control & ~SE_SELF_RELATIVE;
owner = sd_get_owner( sd );
if (req->security_info & OWNER_SECURITY_INFORMATION)
req_sd.owner_len = sd->owner_len;
else
req_sd.owner_len = 0;
group = sd_get_group( sd );
if (req->security_info & GROUP_SECURITY_INFORMATION)
req_sd.group_len = sd->group_len;
else
req_sd.group_len = 0;
req_sd.control |= SE_SACL_PRESENT;
sacl = sd_get_sacl( sd, &present );
if (req->security_info & SACL_SECURITY_INFORMATION && present)
req_sd.sacl_len = sd->sacl_len;
else
req_sd.sacl_len = 0;
req_sd.control |= SE_DACL_PRESENT;
dacl = sd_get_dacl( sd, &present );
if (req->security_info & DACL_SECURITY_INFORMATION && present)
req_sd.dacl_len = sd->dacl_len;
else
req_sd.dacl_len = 0;
reply->sd_len = sizeof(req_sd) + req_sd.owner_len + req_sd.group_len +
req_sd.sacl_len + req_sd.dacl_len;
if (reply->sd_len <= get_reply_max_size())
{
char *ptr = set_reply_data_size(reply->sd_len);
memcpy( ptr, &req_sd, sizeof(req_sd) );
ptr += sizeof(req_sd);
memcpy( ptr, owner, req_sd.owner_len );
ptr += req_sd.owner_len;
memcpy( ptr, group, req_sd.group_len );
ptr += req_sd.group_len;
memcpy( ptr, sacl, req_sd.sacl_len );
ptr += req_sd.sacl_len;
memcpy( ptr, dacl, req_sd.dacl_len );
}
else
set_error(STATUS_BUFFER_TOO_SMALL);
}
release_object( obj );
}