server/symlink.c

   1 /*
   2  * Server-side symbolic link object management
   3  *
   4  * Copyright (C) 2005 Vitaliy Margolen
   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  */
  21
  22 #include "config.h"
  23 #include "wine/port.h"
  24
  25 #include <assert.h>
  26 #include <stdarg.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <sys/types.h>
  30
  31 #include "ntstatus.h"
  32 #define WIN32_NO_STATUS
  33 #include "winternl.h"
  34 #include "ddk/wdm.h"
  35
  36 #include "handle.h"
  37 #include "request.h"
  38 #include "object.h"
  39 #include "unicode.h"
  40
  41 struct symlink
  42 {
  43     struct object    obj;       /* object header */
  44     WCHAR           *target;    /* target of the symlink */
  45     data_size_t      len;       /* target len in bytes */
  46 };
  47
  48 static void symlink_dump( struct object *obj, int verbose );
  49 static struct object_type *symlink_get_type( struct object *obj );
  50 static unsigned int symlink_map_access( struct object *obj, unsigned int access );
  51 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  52                                            unsigned int attr );
  53 static void symlink_destroy( struct object *obj );
  54
  55 static const struct object_ops symlink_ops =
  56 {
  57     sizeof(struct symlink),       /* size */
  58     symlink_dump,                 /* dump */
  59     symlink_get_type,             /* get_type */
  60     no_add_queue,                 /* add_queue */
  61     NULL,                         /* remove_queue */
  62     NULL,                         /* signaled */
  63     NULL,                         /* satisfied */
  64     no_signal,                    /* signal */
  65     no_get_fd,                    /* get_fd */
  66     symlink_map_access,           /* map_access */
  67     default_get_sd,               /* get_sd */
  68     default_set_sd,               /* set_sd */
  69     default_get_full_name,        /* get_full_name */
  70     symlink_lookup_name,          /* lookup_name */
  71     directory_link_name,          /* link_name */
  72     default_unlink_name,          /* unlink_name */
  73     no_open_file,                 /* open_file */
  74     no_kernel_obj_list,           /* get_kernel_obj_list */
  75     no_close_handle,              /* close_handle */
  76     symlink_destroy               /* destroy */
  77 };
  78
  79 static void symlink_dump( struct object *obj, int verbose )
  80 {
  81     struct symlink *symlink = (struct symlink *)obj;
  82     assert( obj->ops == &symlink_ops );
  83
  84     fputs( "Symlink target=\"", stderr );
  85     dump_strW( symlink->target, symlink->len, stderr, "\"\"" );
  86     fputs( "\"\n", stderr );
  87 }
  88
  89 static struct object_type *symlink_get_type( struct object *obj )
  90 {
  91     static const WCHAR name[] = {'S','y','m','b','o','l','i','c','L','i','n','k'};
  92     static const struct unicode_str str = { name, sizeof(name) };
  93     return get_object_type( &str );
  94 }
  95
  96 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  97                                            unsigned int attr )
  98 {
  99     struct symlink *symlink = (struct symlink *)obj;
 100     struct unicode_str target_str, name_left;
 101     struct object *target;
 102
 103     assert( obj->ops == &symlink_ops );
 104
 105     if (!name) return NULL;
 106     if (!name->len && (attr & OBJ_OPENLINK)) return NULL;
 107
 108     target_str.str = symlink->target;
 109     target_str.len = symlink->len;
 110     if ((target = lookup_named_object( NULL, &target_str, attr, &name_left )))
 111     {
 112         if (name_left.len)
 113         {
 114             release_object( target );
 115             target = NULL;
 116             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 117         }
 118     }
 119     return target;
 120 }
 121
 122 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 123 {
 124     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 125     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 126     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 127     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 128     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 129 }
 130
 131 static void symlink_destroy( struct object *obj )
 132 {
 133     struct symlink *symlink = (struct symlink *)obj;
 134     assert( obj->ops == &symlink_ops );
 135     free( symlink->target );
 136 }
 137
 138 struct object *create_symlink( struct object *root, const struct unicode_str *name,
 139                                unsigned int attr, const struct unicode_str *target,
 140                                const struct security_descriptor *sd )
 141 {
 142     struct symlink *symlink;
 143
 144     if (!target->len)
 145     {
 146         set_error( STATUS_INVALID_PARAMETER );
 147         return NULL;
 148     }
 149     if (!(symlink = create_named_object( root, &symlink_ops, name, attr, sd ))) return NULL;
 150     if (get_error() != STATUS_OBJECT_NAME_EXISTS && !(symlink->target = memdup( target->str, target->len )))
 151     {
 152         release_object( symlink );
 153         return NULL;
 154     }
 155     symlink->len = target->len;
 156     return &symlink->obj;
 157 }
 158
 159 /* create a symlink pointing to an existing object */
 160 struct object *create_obj_symlink( struct object *root, const struct unicode_str *name,
 161                                     unsigned int attr, struct object *target,
 162                                     const struct security_descriptor *sd )
 163 {
 164     struct symlink *symlink;
 165     data_size_t len;
 166     WCHAR *target_name;
 167
 168     if (!(target_name = target->ops->get_full_name( target, &len )))
 169     {
 170         set_error( STATUS_INVALID_PARAMETER );
 171         return NULL;
 172     }
 173     if ((symlink = create_named_object( root, &symlink_ops, name, attr, sd )) &&
 174         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 175     {
 176         symlink->target = target_name;
 177         symlink->len = len;
 178     }
 179     else free( target_name );
 180
 181     return &symlink->obj;
 182 }
 183
 184
 185 /* create a symbolic link object */
 186 DECL_HANDLER(create_symlink)
 187 {
 188     struct object *symlink;
 189     struct unicode_str name, target;
 190     struct object *root;
 191     const struct security_descriptor *sd;
 192     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 193
 194     if (!objattr) return;
 195
 196     target.str = get_req_data_after_objattr( objattr, &target.len );
 197     target.len = (target.len / sizeof(WCHAR)) * sizeof(WCHAR);
 198
 199     if ((symlink = create_symlink( root, &name, objattr->attributes, &target, sd )))
 200     {
 201         reply->handle = alloc_handle( current->process, symlink, req->access, objattr->attributes );
 202         release_object( symlink );
 203     }
 204
 205     if (root) release_object( root );
 206 }
 207
 208 /* open a symbolic link object */
 209 DECL_HANDLER(open_symlink)
 210 {
 211     struct unicode_str name = get_req_unicode_str();
 212
 213     reply->handle = open_object( current->process, req->rootdir, req->access,
 214                                  &symlink_ops, &name, req->attributes | OBJ_OPENLINK );
 215 }
 216
 217 /* query a symbolic link object */
 218 DECL_HANDLER(query_symlink)
 219 {
 220     struct symlink *symlink;
 221
 222     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 223                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 224     if (!symlink) return;
 225
 226     reply->total = symlink->len;
 227     if (get_reply_max_size() < symlink->len)
 228         set_error( STATUS_BUFFER_TOO_SMALL );
 229     else
 230         set_reply_data( symlink->target, symlink->len );
 231     release_object( symlink );
 232 }