| /* |
| * Server-side handle management |
| * |
| * Copyright (C) 1998 Alexandre Julliard |
| */ |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "winerror.h" |
| #include "winbase.h" |
| |
| #include "handle.h" |
| #include "process.h" |
| #include "thread.h" |
| #include "request.h" |
| |
| struct handle_entry |
| { |
| struct object *ptr; |
| unsigned int access; |
| }; |
| |
| 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 25 |
| #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) |
| |
| /* global handle macros */ |
| #define HANDLE_OBFUSCATOR 0x544a4def |
| #define HANDLE_IS_GLOBAL(h) (((h) ^ HANDLE_OBFUSCATOR) < 0x10000) |
| #define HANDLE_LOCAL_TO_GLOBAL(h) ((h) ^ HANDLE_OBFUSCATOR) |
| #define HANDLE_GLOBAL_TO_LOCAL(h) ((h) ^ HANDLE_OBFUSCATOR) |
| |
| #define MIN_HANDLE_ENTRIES 32 |
| |
| |
| 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), |
| handle_table_dump, |
| no_add_queue, |
| NULL, /* should never get called */ |
| NULL, /* should never get called */ |
| NULL, /* should never get called */ |
| no_read_fd, |
| no_write_fd, |
| no_flush, |
| no_get_file_info, |
| handle_table_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 = table->entries; |
| |
| 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, "%9d: %p %08x ", i + 1, 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 = table->entries; |
| |
| assert( obj->ops == &handle_table_ops ); |
| |
| for (i = 0; i <= table->last; i++, entry++) |
| { |
| struct object *obj = entry->ptr; |
| entry->ptr = NULL; |
| if (obj) release_object( obj ); |
| } |
| free( table->entries ); |
| } |
| |
| /* allocate a new handle table */ |
| struct object *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->obj; |
| 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 = table->count; |
| |
| if (count >= INT_MAX / 2) return 0; |
| count *= 2; |
| if (!(new_entries = realloc( table->entries, count * sizeof(struct handle_entry) ))) |
| { |
| set_error( ERROR_OUTOFMEMORY ); |
| return 0; |
| } |
| table->entries = new_entries; |
| table->count = count; |
| return 1; |
| } |
| |
| /* find the first free entry in the handle table */ |
| static struct handle_entry *get_free_entry( struct handle_table *table, int *phandle ) |
| { |
| struct handle_entry *entry = table->entries + table->free; |
| int handle; |
| |
| for (handle = table->free; handle <= table->last; handle++, entry++) |
| if (!entry->ptr) goto found; |
| if (handle >= table->count) |
| { |
| if (!grow_handle_table( table )) return NULL; |
| entry = table->entries + handle; /* the entries may have moved */ |
| } |
| table->last = handle; |
| found: |
| table->free = *phandle = handle + 1; /* avoid handle 0 */ |
| return entry; |
| } |
| |
| /* allocate a handle for an object, incrementing its refcount */ |
| /* return the handle, or -1 on error */ |
| int alloc_handle( struct process *process, void *obj, unsigned int access, int inherit ) |
| { |
| struct handle_table *table = (struct handle_table *)process->handles; |
| struct handle_entry *entry; |
| int handle; |
| |
| assert( table ); |
| assert( !(access & RESERVED_ALL) ); |
| if (inherit) access |= RESERVED_INHERIT; |
| |
| if (!(entry = get_free_entry( table, &handle ))) return -1; |
| entry->ptr = grab_object( obj ); |
| entry->access = access; |
| return handle; |
| } |
| |
| /* allocate a global handle for an object, incrementing its refcount */ |
| /* return the handle, or -1 on error */ |
| static int alloc_global_handle( void *obj, unsigned int access ) |
| { |
| struct handle_entry *entry; |
| int handle; |
| |
| if (!global_table) |
| { |
| if (!(global_table = (struct handle_table *)alloc_handle_table( NULL, 0 ))) return -1; |
| } |
| if (!(entry = get_free_entry( global_table, &handle ))) return -1; |
| entry->ptr = grab_object( obj ); |
| entry->access = access; |
| return HANDLE_LOCAL_TO_GLOBAL(handle); |
| } |
| |
| /* return an handle entry, or NULL if the handle is invalid */ |
| static struct handle_entry *get_handle( struct process *process, int handle ) |
| { |
| struct handle_table *table = (struct handle_table *)process->handles; |
| struct handle_entry *entry; |
| |
| if (HANDLE_IS_GLOBAL(handle)) |
| { |
| handle = HANDLE_GLOBAL_TO_LOCAL(handle); |
| table = global_table; |
| } |
| if (!table) goto error; |
| handle--; /* handles start at 1 */ |
| if (handle < 0) goto error; |
| if (handle > table->last) goto error; |
| entry = table->entries + handle; |
| if (!entry->ptr) goto error; |
| return entry; |
| |
| error: |
| set_error( ERROR_INVALID_HANDLE ); |
| return NULL; |
| } |
| |
| /* 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 object *copy_handle_table( struct process *process, struct process *parent ) |
| { |
| struct handle_table *parent_table = (struct handle_table *)parent->handles; |
| struct handle_table *table; |
| int i; |
| |
| assert( parent_table ); |
| assert( parent_table->obj.ops == &handle_table_ops ); |
| |
| if (!(table = (struct handle_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; |
| if (ptr->access & RESERVED_INHERIT) grab_object( ptr->ptr ); |
| else ptr->ptr = NULL; /* don't inherit this entry */ |
| } |
| } |
| /* attempt to shrink the table */ |
| shrink_handle_table( table ); |
| return &table->obj; |
| } |
| |
| /* close a handle and decrement the refcount of the associated object */ |
| /* return 1 if OK, 0 on error */ |
| int close_handle( struct process *process, int handle ) |
| { |
| struct handle_table *table; |
| struct handle_entry *entry; |
| struct object *obj; |
| |
| if (!(entry = get_handle( process, handle ))) return 0; |
| if (entry->access & RESERVED_CLOSE_PROTECT) return 0; /* FIXME: error code */ |
| obj = entry->ptr; |
| entry->ptr = NULL; |
| table = HANDLE_IS_GLOBAL(handle) ? global_table : (struct handle_table *)process->handles; |
| if (entry < table->entries + table->free) table->free = entry - table->entries; |
| if (entry == table->entries + table->last) shrink_handle_table( table ); |
| release_object( obj ); |
| return 1; |
| } |
| |
| /* close all the global handles */ |
| void close_global_handles(void) |
| { |
| if (global_table) |
| { |
| release_object( global_table ); |
| global_table = NULL; |
| } |
| } |
| |
| /* retrieve the object corresponding to a handle, incrementing its refcount */ |
| struct object *get_handle_obj( struct process *process, int handle, |
| unsigned int access, const struct object_ops *ops ) |
| { |
| struct handle_entry *entry; |
| struct object *obj; |
| |
| switch( handle ) |
| { |
| case 0xfffffffe: /* current thread pseudo-handle */ |
| obj = ¤t->obj; |
| break; |
| case 0x7fffffff: /* current process pseudo-handle */ |
| obj = (struct object *)current->process; |
| break; |
| default: |
| if (!(entry = get_handle( process, handle ))) return NULL; |
| if ((entry->access & access) != access) |
| { |
| set_error( ERROR_ACCESS_DENIED ); |
| return NULL; |
| } |
| obj = entry->ptr; |
| break; |
| } |
| if (ops && (obj->ops != ops)) |
| { |
| set_error( ERROR_INVALID_HANDLE ); /* not the right type */ |
| return NULL; |
| } |
| return grab_object( obj ); |
| } |
| |
| /* get/set the handle reserved flags */ |
| /* return the new flags (or -1 on error) */ |
| static int set_handle_info( struct process *process, int handle, int mask, int flags ) |
| { |
| struct handle_entry *entry; |
| |
| if (!(entry = get_handle( process, handle ))) return -1; |
| mask = (mask << RESERVED_SHIFT) & RESERVED_ALL; |
| flags = (flags << RESERVED_SHIFT) & mask; |
| entry->access = (entry->access & ~mask) | flags; |
| return (entry->access & RESERVED_ALL) >> RESERVED_SHIFT; |
| } |
| |
| /* duplicate a handle */ |
| int duplicate_handle( struct process *src, int src_handle, struct process *dst, |
| unsigned int access, int inherit, int options ) |
| { |
| int res; |
| struct object *obj = get_handle_obj( src, src_handle, 0, NULL ); |
| |
| if (!obj) return -1; |
| if (options & DUP_HANDLE_SAME_ACCESS) |
| { |
| struct handle_entry *entry = get_handle( src, src_handle ); |
| if (entry) |
| access = entry->access; |
| else /* pseudo-handle, give it full access */ |
| { |
| access = STANDARD_RIGHTS_ALL | SPECIFIC_RIGHTS_ALL; |
| clear_error(); |
| } |
| } |
| access &= ~RESERVED_ALL; |
| if (options & DUP_HANDLE_MAKE_GLOBAL) |
| res = alloc_global_handle( obj, access ); |
| else |
| res = alloc_handle( dst, obj, access, inherit ); |
| release_object( obj ); |
| return res; |
| } |
| |
| /* open a new handle to an existing object */ |
| int open_object( const char *name, size_t len, const struct object_ops *ops, |
| unsigned int access, int inherit ) |
| { |
| struct object *obj = find_object( name, len ); |
| if (!obj) |
| { |
| set_error( ERROR_FILE_NOT_FOUND ); |
| return -1; |
| } |
| if (ops && obj->ops != ops) |
| { |
| release_object( obj ); |
| set_error( ERROR_INVALID_HANDLE ); /* FIXME: not the right type */ |
| return -1; |
| } |
| return alloc_handle( current->process, obj, access, inherit ); |
| } |
| |
| /* close a handle */ |
| DECL_HANDLER(close_handle) |
| { |
| close_handle( current->process, req->handle ); |
| } |
| |
| /* get information about a handle */ |
| DECL_HANDLER(get_handle_info) |
| { |
| req->flags = set_handle_info( current->process, req->handle, 0, 0 ); |
| } |
| |
| /* set a handle information */ |
| DECL_HANDLER(set_handle_info) |
| { |
| set_handle_info( current->process, req->handle, req->mask, req->flags ); |
| } |
| |
| /* duplicate a handle */ |
| DECL_HANDLER(dup_handle) |
| { |
| struct process *src, *dst; |
| |
| req->handle = -1; |
| if ((src = get_process_from_handle( req->src_process, PROCESS_DUP_HANDLE ))) |
| { |
| if (req->options & DUP_HANDLE_MAKE_GLOBAL) |
| { |
| req->handle = duplicate_handle( src, req->src_handle, NULL, |
| req->access, req->inherit, req->options ); |
| } |
| else if ((dst = get_process_from_handle( req->dst_process, PROCESS_DUP_HANDLE ))) |
| { |
| req->handle = duplicate_handle( src, req->src_handle, dst, |
| req->access, req->inherit, req->options ); |
| release_object( dst ); |
| } |
| /* close the handle no matter what happened */ |
| if (req->options & DUP_HANDLE_CLOSE_SOURCE) |
| close_handle( src, req->src_handle ); |
| release_object( src ); |
| } |
| } |