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     default_get_sd,               /* get_sd */
  66     default_set_sd,               /* set_sd */
  67     symlink_lookup_name,          /* lookup_name */
  68     no_open_file,                 /* open_file */
  69     no_close_handle,              /* close_handle */
  70     symlink_destroy               /* destroy */
  71 };
  72
  73 static void symlink_dump( struct object *obj, int verbose )
  74 {
  75     struct symlink *symlink = (struct symlink *)obj;
  76     assert( obj->ops == &symlink_ops );
  77
  78     fprintf( stderr, "Symlink " );
  79     dump_object_name( obj );
  80     fprintf( stderr, " -> L\"" );
  81     dump_strW( symlink->target, symlink->len / sizeof(WCHAR), stderr, "\"\"" );
  82     fprintf( stderr, "\"\n" );
  83 }
  84
  85 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  86                                            unsigned int attr )
  87 {
  88     struct symlink *symlink = (struct symlink *)obj;
  89     struct unicode_str target_str, name_left;
  90     struct object *target;
  91
  92     assert( obj->ops == &symlink_ops );
  93     if (attr & OBJ_OPENLINK) return NULL;
  94
  95     target_str.str = symlink->target;
  96     target_str.len = symlink->len;
  97     if ((target = find_object_dir( NULL, &target_str, attr, &name_left )))
  98     {
  99         if (name_left.len)
 100         {
 101             release_object( target );
 102             target = NULL;
 103             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 104         }
 105     }
 106     return target;
 107 }
 108
 109 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 110 {
 111     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 112     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 113     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 114     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 115     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 116 }
 117
 118 static void symlink_destroy( struct object *obj )
 119 {
 120     struct symlink *symlink = (struct symlink *)obj;
 121     assert( obj->ops == &symlink_ops );
 122     free( symlink->target );
 123 }
 124
 125 struct symlink *create_symlink( struct directory *root, const struct unicode_str *name,
 126                                 unsigned int attr, const struct unicode_str *target )
 127 {
 128     struct symlink *symlink;
 129
 130     if (!target->len)
 131     {
 132         set_error( STATUS_INVALID_PARAMETER );
 133         return NULL;
 134     }
 135     if ((symlink = create_named_object_dir( root, name, attr, &symlink_ops )) &&
 136         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 137     {
 138         if ((symlink->target = memdup( target->str, target->len )))
 139             symlink->len = target->len;
 140         else
 141         {
 142             release_object( symlink );
 143             symlink = NULL;
 144         }
 145     }
 146     return symlink;
 147 }
 148
 149
 150 /* create a symbolic link object */
 151 DECL_HANDLER(create_symlink)
 152 {
 153     struct symlink *symlink;
 154     struct unicode_str name, target;
 155     struct directory *root = NULL;
 156
 157     if (req->name_len > get_req_data_size())
 158     {
 159         set_error( STATUS_INVALID_PARAMETER );
 160         return;
 161     }
 162     name.str   = get_req_data();
 163     target.str = name.str + req->name_len / sizeof(WCHAR);
 164     name.len   = (target.str - name.str) * sizeof(WCHAR);
 165     target.len = ((get_req_data_size() - name.len) / sizeof(WCHAR)) * sizeof(WCHAR);
 166
 167     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 168         return;
 169
 170     if ((symlink = create_symlink( root, &name, req->attributes, &target )))
 171     {
 172         reply->handle = alloc_handle( current->process, symlink, req->access, req->attributes );
 173         release_object( symlink );
 174     }
 175
 176     if (root) release_object( root );
 177 }
 178
 179 /* open a symbolic link object */
 180 DECL_HANDLER(open_symlink)
 181 {
 182     struct unicode_str name;
 183     struct directory *root = NULL;
 184     struct symlink *symlink;
 185
 186     get_req_unicode_str( &name );
 187     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 188         return;
 189
 190     if ((symlink = open_object_dir( root, &name, req->attributes | OBJ_OPENLINK, &symlink_ops )))
 191     {
 192         reply->handle = alloc_handle( current->process, &symlink->obj, req->access, req->attributes );
 193         release_object( symlink );
 194     }
 195
 196     if (root) release_object( root );
 197 }
 198
 199 /* query a symbolic link object */
 200 DECL_HANDLER(query_symlink)
 201 {
 202     struct symlink *symlink;
 203
 204     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 205                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 206     if (!symlink) return;
 207
 208     if (get_reply_max_size() < symlink->len)
 209         set_error( STATUS_BUFFER_TOO_SMALL );
 210     else
 211         set_reply_data( symlink->target, symlink->len );
 212     release_object( symlink );
 213 }