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     no_open_file,                 /* open_file */
  71     no_close_handle,              /* close_handle */
  72     symlink_destroy               /* destroy */
  73 };
  74
  75 static void symlink_dump( struct object *obj, int verbose )
  76 {
  77     struct symlink *symlink = (struct symlink *)obj;
  78     assert( obj->ops == &symlink_ops );
  79
  80     fprintf( stderr, "Symlink " );
  81     dump_object_name( obj );
  82     fprintf( stderr, " -> L\"" );
  83     dump_strW( symlink->target, symlink->len / sizeof(WCHAR), stderr, "\"\"" );
  84     fprintf( stderr, "\"\n" );
  85 }
  86
  87 static struct object_type *symlink_get_type( struct object *obj )
  88 {
  89     static const WCHAR name[] = {'S','y','m','b','o','l','i','c','L','i','n','k'};
  90     static const struct unicode_str str = { name, sizeof(name) };
  91     return get_object_type( &str );
  92 }
  93
  94 static struct object *symlink_lookup_name( struct object *obj, struct unicode_str *name,
  95                                            unsigned int attr )
  96 {
  97     struct symlink *symlink = (struct symlink *)obj;
  98     struct unicode_str target_str, name_left;
  99     struct object *target;
 100
 101     assert( obj->ops == &symlink_ops );
 102     if (attr & OBJ_OPENLINK) return NULL;
 103
 104     target_str.str = symlink->target;
 105     target_str.len = symlink->len;
 106     if ((target = find_object_dir( NULL, &target_str, attr, &name_left )))
 107     {
 108         if (name_left.len)
 109         {
 110             release_object( target );
 111             target = NULL;
 112             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
 113         }
 114     }
 115     return target;
 116 }
 117
 118 static unsigned int symlink_map_access( struct object *obj, unsigned int access )
 119 {
 120     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | SYMBOLIC_LINK_QUERY;
 121     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE;
 122     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
 123     if (access & GENERIC_ALL)     access |= SYMBOLIC_LINK_ALL_ACCESS;
 124     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 125 }
 126
 127 static void symlink_destroy( struct object *obj )
 128 {
 129     struct symlink *symlink = (struct symlink *)obj;
 130     assert( obj->ops == &symlink_ops );
 131     free( symlink->target );
 132 }
 133
 134 struct symlink *create_symlink( struct directory *root, const struct unicode_str *name,
 135                                 unsigned int attr, const struct unicode_str *target )
 136 {
 137     struct symlink *symlink;
 138
 139     if (!target->len)
 140     {
 141         set_error( STATUS_INVALID_PARAMETER );
 142         return NULL;
 143     }
 144     if ((symlink = create_named_object_dir( root, name, attr, &symlink_ops )) &&
 145         (get_error() != STATUS_OBJECT_NAME_EXISTS))
 146     {
 147         if ((symlink->target = memdup( target->str, target->len )))
 148             symlink->len = target->len;
 149         else
 150         {
 151             release_object( symlink );
 152             symlink = NULL;
 153         }
 154     }
 155     return symlink;
 156 }
 157
 158
 159 /* create a symbolic link object */
 160 DECL_HANDLER(create_symlink)
 161 {
 162     struct symlink *symlink;
 163     struct unicode_str name, target;
 164     struct directory *root = NULL;
 165
 166     if (req->name_len > get_req_data_size())
 167     {
 168         set_error( STATUS_INVALID_PARAMETER );
 169         return;
 170     }
 171     name.str   = get_req_data();
 172     target.str = name.str + req->name_len / sizeof(WCHAR);
 173     name.len   = (target.str - name.str) * sizeof(WCHAR);
 174     target.len = ((get_req_data_size() - name.len) / sizeof(WCHAR)) * sizeof(WCHAR);
 175
 176     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 177         return;
 178
 179     if ((symlink = create_symlink( root, &name, req->attributes, &target )))
 180     {
 181         reply->handle = alloc_handle( current->process, symlink, req->access, req->attributes );
 182         release_object( symlink );
 183     }
 184
 185     if (root) release_object( root );
 186 }
 187
 188 /* open a symbolic link object */
 189 DECL_HANDLER(open_symlink)
 190 {
 191     struct unicode_str name;
 192     struct directory *root = NULL;
 193     struct symlink *symlink;
 194
 195     get_req_unicode_str( &name );
 196     if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
 197         return;
 198
 199     if ((symlink = open_object_dir( root, &name, req->attributes | OBJ_OPENLINK, &symlink_ops )))
 200     {
 201         reply->handle = alloc_handle( current->process, &symlink->obj, req->access, req->attributes );
 202         release_object( symlink );
 203     }
 204
 205     if (root) release_object( root );
 206 }
 207
 208 /* query a symbolic link object */
 209 DECL_HANDLER(query_symlink)
 210 {
 211     struct symlink *symlink;
 212
 213     symlink = (struct symlink *)get_handle_obj( current->process, req->handle,
 214                                                 SYMBOLIC_LINK_QUERY, &symlink_ops );
 215     if (!symlink) return;
 216
 217     if (get_reply_max_size() < symlink->len)
 218         set_error( STATUS_BUFFER_TOO_SMALL );
 219     else
 220         set_reply_data( symlink->target, symlink->len );
 221     release_object( symlink );
 222 }