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 unsigned int symlink_map_access( struct object *obj, unsigned int access );
  50 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  51                                            unsigned int attr );
  52 static void symlink_destroy( struct object *obj );
  53
  54 static const struct object_ops symlink_ops =
  55 {
  56     sizeof(struct symlink),       /* size */
  57     symlink_dump,                 /* dump */
  58     no_add_queue,                 /* add_queue */
  59     NULL,                         /* remove_queue */
  60     NULL,                         /* signaled */
  61     NULL,                         /* satisfied */
  62     no_signal,                    /* signal */
  63     no_get_fd,                    /* get_fd */
  64     symlink_map_access,           /* map_access */
  65     symlink_lookup_name,          /* lookup_name */
  66     no_open_file,                 /* open_file */
  67     no_close_handle,              /* close_handle */
  68     symlink_destroy               /* destroy */
  69 };
  70
  71 static void symlink_dump( struct object *obj, int verbose )
  72 {
  73     struct symlink *symlink = (struct symlink *)obj;
  74     assert( obj->ops == &symlink_ops );
  75
  76     fprintf( stderr, "Symlink " );
  77     dump_object_name( obj );
  78     fprintf( stderr, " -> L\"" );
  79     dump_strW( symlink->target, symlink->len / sizeof(WCHAR), stderr, "\"\"" );
  80     fprintf( stderr, "\"\n" );
  81 }
  82
  83 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  84                                            unsigned int attr )
  85 {
  86     struct symlink *symlink = (struct symlink *)obj;
  87     struct unicode_str target_str, name_left;
  88     struct object *target;
  89
  90     assert( obj->ops == &symlink_ops );
  91     if (attr & OBJ_OPENLINK) return NULL;
  92
  93     target_str.str = symlink->target;
  94     target_str.len = symlink->len;
  95     if ((target = find_object_dir( NULL, &target_str, attr, &name_left )))
  96     {
  97         if (name_left.len)
  98         {
  99             release_object( target );
 100             target = NULL;
 101             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 102         }
 103     }
 104     return target;
 105 }
 106
 107 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 108 {
 109     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 110     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 111     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 112     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 113     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 114 }
 115
 116 static void symlink_destroy( struct object *obj )
 117 {
 118     struct symlink *symlink = (struct symlink *)obj;
 119     assert( obj->ops == &symlink_ops );
 120     free( symlink->target );
 121 }
 122
 123 struct symlink *create_symlink( struct directory *root, const struct unicode_str *name,
 124                                 unsigned int attr, const struct unicode_str *target )
 125 {
 126     struct symlink *symlink;
 127
 128     if (!target->len)
 129     {
 130         set_error( STATUS_INVALID_PARAMETER );
 131         return NULL;
 132     }
 133     if ((symlink = create_named_object_dir( root, name, attr, &symlink_ops )) &&
 134         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 135     {
 136         if ((symlink->target = memdup( target->str, target->len )))
 137             symlink->len = target->len;
 138         else
 139         {
 140             release_object( symlink );
 141             symlink = NULL;
 142         }
 143     }
 144     return symlink;
 145 }
 146
 147
 148 /* create a symbolic link object */
 149 DECL_HANDLER(create_symlink)
 150 {
 151     struct symlink *symlink;
 152     struct unicode_str name, target;
 153     struct directory *root = NULL;
 154
 155     if (req->name_len > get_req_data_size())
 156     {
 157         set_error( STATUS_INVALID_PARAMETER );
 158         return;
 159     }
 160     name.str   = get_req_data();
 161     target.str = name.str + req->name_len / sizeof(WCHAR);
 162     name.len   = (target.str - name.str) * sizeof(WCHAR);
 163     target.len = ((get_req_data_size() - name.len) / sizeof(WCHAR)) * sizeof(WCHAR);
 164
 165     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 166         return;
 167
 168     if ((symlink = create_symlink( root, &name, req->attributes, &target )))
 169     {
 170         reply->handle = alloc_handle( current->process, symlink, req->access, req->attributes );
 171         release_object( symlink );
 172     }
 173
 174     if (root) release_object( root );
 175 }
 176
 177 /* open a symbolic link object */
 178 DECL_HANDLER(open_symlink)
 179 {
 180     struct unicode_str name;
 181     struct directory *root = NULL;
 182     struct symlink *symlink;
 183
 184     get_req_unicode_str( &name );
 185     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 186         return;
 187
 188     if ((symlink = open_object_dir( root, &name, req->attributes | OBJ_OPENLINK, &symlink_ops )))
 189     {
 190         reply->handle = alloc_handle( current->process, &symlink->obj, req->access, req->attributes );
 191         release_object( symlink );
 192     }
 193
 194     if (root) release_object( root );
 195 }
 196
 197 /* query a symbolic link object */
 198 DECL_HANDLER(query_symlink)
 199 {
 200     struct symlink *symlink;
 201
 202     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 203                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 204     if (!symlink) return;
 205
 206     if (get_reply_max_size() < symlink->len)
 207         set_error( STATUS_BUFFER_TOO_SMALL );
 208     else
 209         set_reply_data( symlink->target, symlink->len );
 210     release_object( symlink );
 211 }