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, struct object *root );
  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, struct object *root )
  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     if (obj == root) return NULL;
 108
 109     target_str.str = symlink->target;
 110     target_str.len = symlink->len;
 111     if ((target = lookup_named_object( NULL, &target_str, attr, &name_left )))
 112     {
 113         if (name_left.len)
 114         {
 115             release_object( target );
 116             target = NULL;
 117             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 118         }
 119     }
 120     return target;
 121 }
 122
 123 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 124 {
 125     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 126     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 127     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 128     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 129     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 130 }
 131
 132 static void symlink_destroy( struct object *obj )
 133 {
 134     struct symlink *symlink = (struct symlink *)obj;
 135     assert( obj->ops == &symlink_ops );
 136     free( symlink->target );
 137 }
 138
 139 struct object *create_symlink( struct object *root, const struct unicode_str *name,
 140                                unsigned int attr, const struct unicode_str *target,
 141                                const struct security_descriptor *sd )
 142 {
 143     struct symlink *symlink;
 144
 145     if (!target->len)
 146     {
 147         set_error( STATUS_INVALID_PARAMETER );
 148         return NULL;
 149     }
 150     if (!(symlink = create_named_object( root, &symlink_ops, name, attr, sd ))) return NULL;
 151     if (get_error() != STATUS_OBJECT_NAME_EXISTS && !(symlink->target = memdup( target->str, target->len )))
 152     {
 153         release_object( symlink );
 154         return NULL;
 155     }
 156     symlink->len = target->len;
 157     return &symlink->obj;
 158 }
 159
 160 /* create a symlink pointing to an existing object */
 161 struct object *create_obj_symlink( struct object *root, const struct unicode_str *name,
 162                                     unsigned int attr, struct object *target,
 163                                     const struct security_descriptor *sd )
 164 {
 165     struct symlink *symlink;
 166     data_size_t len;
 167     WCHAR *target_name;
 168
 169     if (!(target_name = target->ops->get_full_name( target, &len )))
 170     {
 171         set_error( STATUS_INVALID_PARAMETER );
 172         return NULL;
 173     }
 174     if ((symlink = create_named_object( root, &symlink_ops, name, attr, sd )) &&
 175         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 176     {
 177         symlink->target = target_name;
 178         symlink->len = len;
 179     }
 180     else free( target_name );
 181
 182     return &symlink->obj;
 183 }
 184
 185
 186 /* create a symbolic link object */
 187 DECL_HANDLER(create_symlink)
 188 {
 189     struct object *symlink;
 190     struct unicode_str name, target;
 191     struct object *root;
 192     const struct security_descriptor *sd;
 193     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 194
 195     if (!objattr) return;
 196
 197     target.str = get_req_data_after_objattr( objattr, &target.len );
 198     target.len = (target.len / sizeof(WCHAR)) * sizeof(WCHAR);
 199
 200     if ((symlink = create_symlink( root, &name, objattr->attributes, &target, sd )))
 201     {
 202         reply->handle = alloc_handle( current->process, symlink, req->access, objattr->attributes );
 203         release_object( symlink );
 204     }
 205
 206     if (root) release_object( root );
 207 }
 208
 209 /* open a symbolic link object */
 210 DECL_HANDLER(open_symlink)
 211 {
 212     struct unicode_str name = get_req_unicode_str();
 213
 214     reply->handle = open_object( current->process, req->rootdir, req->access,
 215                                  &symlink_ops, &name, req->attributes | OBJ_OPENLINK );
 216 }
 217
 218 /* query a symbolic link object */
 219 DECL_HANDLER(query_symlink)
 220 {
 221     struct symlink *symlink;
 222
 223     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 224                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 225     if (!symlink) return;
 226
 227     reply->total = symlink->len;
 228     if (get_reply_max_size() < symlink->len)
 229         set_error( STATUS_BUFFER_TOO_SMALL );
 230     else
 231         set_reply_data( symlink->target, symlink->len );
 232     release_object( symlink );
 233 }