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