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     symlink_lookup_name,          /* lookup_name */
  70     directory_link_name,          /* link_name */
  71     default_unlink_name,          /* unlink_name */
  72     no_open_file,                 /* open_file */
  73     no_kernel_obj_list,           /* get_kernel_obj_list */
  74     no_close_handle,              /* close_handle */
  75     symlink_destroy               /* destroy */
  76 };
  77
  78 static void symlink_dump( struct object *obj, int verbose )
  79 {
  80     struct symlink *symlink = (struct symlink *)obj;
  81     assert( obj->ops == &symlink_ops );
  82
  83     fputs( "Symlink target=\"", stderr );
  84     dump_strW( symlink->target, symlink->len / sizeof(WCHAR), stderr, "\"\"" );
  85     fputs( "\"\n", stderr );
  86 }
  87
  88 static struct object_type *symlink_get_type( struct object *obj )
  89 {
  90     static const WCHAR name[] = {'S','y','m','b','o','l','i','c','L','i','n','k'};
  91     static const struct unicode_str str = { name, sizeof(name) };
  92     return get_object_type( &str );
  93 }
  94
  95 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  96                                            unsigned int attr )
  97 {
  98     struct symlink *symlink = (struct symlink *)obj;
  99     struct unicode_str target_str, name_left;
 100     struct object *target;
 101
 102     assert( obj->ops == &symlink_ops );
 103
 104     if (!name) return NULL;
 105     if (!name->len && (attr & OBJ_OPENLINK)) return NULL;
 106
 107     target_str.str = symlink->target;
 108     target_str.len = symlink->len;
 109     if ((target = lookup_named_object( NULL, &target_str, attr, &name_left )))
 110     {
 111         if (name_left.len)
 112         {
 113             release_object( target );
 114             target = NULL;
 115             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 116         }
 117     }
 118     return target;
 119 }
 120
 121 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 122 {
 123     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 124     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 125     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 126     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 127     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 128 }
 129
 130 static void symlink_destroy( struct object *obj )
 131 {
 132     struct symlink *symlink = (struct symlink *)obj;
 133     assert( obj->ops == &symlink_ops );
 134     free( symlink->target );
 135 }
 136
 137 static struct symlink *create_symlink( struct object *root, const struct unicode_str *name,
 138                                        unsigned int attr, const struct unicode_str *target,
 139                                        const struct security_descriptor *sd )
 140 {
 141     struct symlink *symlink;
 142
 143     if (!target->len)
 144     {
 145         set_error( STATUS_INVALID_PARAMETER );
 146         return NULL;
 147     }
 148     if ((symlink = create_named_object( root, &symlink_ops, name, attr, sd )) &&
 149         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 150     {
 151         if ((symlink->target = memdup( target->str, target->len )))
 152         {
 153             symlink->len = target->len;
 154         }
 155         else
 156         {
 157             release_object( symlink );
 158             symlink = NULL;
 159         }
 160     }
 161     return symlink;
 162 }
 163
 164 /* create a symlink pointing to an existing object */
 165 struct object *create_obj_symlink( struct object *root, const struct unicode_str *name,
 166                                     unsigned int attr, struct object *target,
 167                                     const struct security_descriptor *sd )
 168 {
 169     struct symlink *symlink;
 170     data_size_t len;
 171     WCHAR *target_name;
 172
 173     if (!(target_name = get_object_full_name( target, &len )))
 174     {
 175         set_error( STATUS_INVALID_PARAMETER );
 176         return NULL;
 177     }
 178     if ((symlink = create_named_object( root, &symlink_ops, name, attr, sd )) &&
 179         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 180     {
 181         symlink->target = target_name;
 182         symlink->len = len;
 183     }
 184     else free( target_name );
 185
 186     return &symlink->obj;
 187 }
 188
 189
 190 /* create a symbolic link object */
 191 DECL_HANDLER(create_symlink)
 192 {
 193     struct symlink *symlink;
 194     struct unicode_str name, target;
 195     struct object *root;
 196     const struct security_descriptor *sd;
 197     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 198
 199     if (!objattr) return;
 200
 201     target.str = get_req_data_after_objattr( objattr, &target.len );
 202     target.len = (target.len / sizeof(WCHAR)) * sizeof(WCHAR);
 203
 204     if ((symlink = create_symlink( root, &name, objattr->attributes, &target, sd )))
 205     {
 206         reply->handle = alloc_handle( current->process, symlink, req->access, objattr->attributes );
 207         release_object( symlink );
 208     }
 209
 210     if (root) release_object( root );
 211 }
 212
 213 /* open a symbolic link object */
 214 DECL_HANDLER(open_symlink)
 215 {
 216     struct unicode_str name = get_req_unicode_str();
 217
 218     reply->handle = open_object( current->process, req->rootdir, req->access,
 219                                  &symlink_ops, &name, req->attributes | OBJ_OPENLINK );
 220 }
 221
 222 /* query a symbolic link object */
 223 DECL_HANDLER(query_symlink)
 224 {
 225     struct symlink *symlink;
 226
 227     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 228                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 229     if (!symlink) return;
 230
 231     reply->total = symlink->len;
 232     if (get_reply_max_size() < symlink->len)
 233         set_error( STATUS_BUFFER_TOO_SMALL );
 234     else
 235         set_reply_data( symlink->target, symlink->len );
 236     release_object( symlink );
 237 }