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