source3/modules/vfs_acl_xattr.c

   1 /*
   2  * Store Windows ACLs in xattrs.
   3  *
   4  * Copyright (C) Volker Lendecke, 2008
   5  * Copyright (C) Jeremy Allison, 2008
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /* NOTE: This is an experimental module, not yet finished. JRA. */
  22
  23 #include "includes.h"
  24 #include "librpc/gen_ndr/xattr.h"
  25 #include "librpc/gen_ndr/ndr_xattr.h"
  26 #include "../lib/crypto/crypto.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_VFS
  30
  31 /*******************************************************************
  32  Pull a security descriptor into a DATA_BLOB from a xattr.
  33 *******************************************************************/
  34
  35 NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  36                         vfs_handle_struct *handle,
  37                         files_struct *fsp,
  38                         const char *name,
  39                         DATA_BLOB *pblob)
  40 {
  41         size_t size = 1024;
  42         uint8_t *val = NULL;
  43         uint8_t *tmp;
  44         ssize_t sizeret;
  45         int saved_errno = 0;
  46
  47         ZERO_STRUCTP(pblob);
  48
  49   again:
  50
  51         tmp = TALLOC_REALLOC_ARRAY(ctx, val, uint8_t, size);
  52         if (tmp == NULL) {
  53                 TALLOC_FREE(val);
  54                 return NT_STATUS_NO_MEMORY;
  55         }
  56         val = tmp;
  57
  58         become_root();
  59         if (fsp && fsp->fh->fd != -1) {
  60                 sizeret = SMB_VFS_FGETXATTR(fsp, XATTR_NTACL_NAME, val, size);
  61         } else {
  62                 sizeret = SMB_VFS_GETXATTR(handle->conn, name,
  63                                         XATTR_NTACL_NAME, val, size);
  64         }
  65         if (sizeret == -1) {
  66                 saved_errno = errno;
  67         }
  68         unbecome_root();
  69
  70         /* Max ACL size is 65536 bytes. */
  71         if (sizeret == -1) {
  72                 errno = saved_errno;
  73                 if ((errno == ERANGE) && (size != 65536)) {
  74                         /* Too small, try again. */
  75                         size = 65536;
  76                         goto again;
  77                 }
  78
  79                 /* Real error - exit here. */
  80                 TALLOC_FREE(val);
  81                 return map_nt_error_from_unix(errno);
  82         }
  83
  84         pblob->data = val;
  85         pblob->length = sizeret;
  86         return NT_STATUS_OK;
  87 }
  88
  89 /*******************************************************************
  90  Store a DATA_BLOB into an xattr given an fsp pointer.
  91 *******************************************************************/
  92
  93 NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  94                                 files_struct *fsp,
  95                                 DATA_BLOB *pblob)
  96 {
  97         int ret;
  98         int saved_errno = 0;
  99
 100         DEBUG(10,("store_acl_blob_fsp: storing blob length %u on file %s\n",
 101                   (unsigned int)pblob->length, fsp_str_dbg(fsp)));
 102
 103         become_root();
 104         if (fsp->fh->fd != -1) {
 105                 ret = SMB_VFS_FSETXATTR(fsp, XATTR_NTACL_NAME,
 106                         pblob->data, pblob->length, 0);
 107         } else {
 108                 ret = SMB_VFS_SETXATTR(fsp->conn, fsp->fsp_name->base_name,
 109                                 XATTR_NTACL_NAME,
 110                                 pblob->data, pblob->length, 0);
 111         }
 112         if (ret) {
 113                 saved_errno = errno;
 114         }
 115         unbecome_root();
 116         if (ret) {
 117                 errno = saved_errno;
 118                 DEBUG(5, ("store_acl_blob_fsp: setting attr failed for file %s"
 119                         "with error %s\n",
 120                         fsp_str_dbg(fsp),
 121                         strerror(errno) ));
 122                 return map_nt_error_from_unix(errno);
 123         }
 124         return NT_STATUS_OK;
 125 }
 126
 127 /*******************************************************************
 128  Store a DATA_BLOB into an xattr given a pathname.
 129 *******************************************************************/
 130
 131 NTSTATUS store_acl_blob_pathname(vfs_handle_struct *handle,
 132                                         const char *fname,
 133                                         DATA_BLOB *pblob)
 134 {
 135         connection_struct *conn = handle->conn;
 136         int ret;
 137         int saved_errno = 0;
 138
 139         DEBUG(10,("store_acl_blob_pathname: storing blob "
 140                         "length %u on file %s\n",
 141                         (unsigned int)pblob->length, fname));
 142
 143         become_root();
 144         ret = SMB_VFS_SETXATTR(conn, fname,
 145                                 XATTR_NTACL_NAME,
 146                                 pblob->data, pblob->length, 0);
 147         if (ret) {
 148                 saved_errno = errno;
 149         }
 150         unbecome_root();
 151         if (ret) {
 152                 errno = saved_errno;
 153                 DEBUG(5, ("store_acl_blob_pathname: setting attr failed "
 154                         "for file %s with error %s\n",
 155                         fname,
 156                         strerror(errno) ));
 157                 return map_nt_error_from_unix(errno);
 158         }
 159         return NT_STATUS_OK;
 160 }
 161
 162 /*********************************************************************
 163  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 164 *********************************************************************/
 165
 166 static int sys_acl_set_file_xattr(vfs_handle_struct *handle,
 167                               const char *name,
 168                               SMB_ACL_TYPE_T type,
 169                               SMB_ACL_T theacl)
 170 {
 171         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FILE(handle,
 172                                                 name,
 173                                                 type,
 174                                                 theacl);
 175         if (ret == -1) {
 176                 return -1;
 177         }
 178
 179         become_root();
 180         SMB_VFS_REMOVEXATTR(handle->conn, name, XATTR_NTACL_NAME);
 181         unbecome_root();
 182
 183         return ret;
 184 }
 185
 186 /*********************************************************************
 187  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 188 *********************************************************************/
 189
 190 static int sys_acl_set_fd_xattr(vfs_handle_struct *handle,
 191                             files_struct *fsp,
 192                             SMB_ACL_T theacl)
 193 {
 194         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FD(handle,
 195                                                 fsp,
 196                                                 theacl);
 197         if (ret == -1) {
 198                 return -1;
 199         }
 200
 201         become_root();
 202         SMB_VFS_FREMOVEXATTR(fsp, XATTR_NTACL_NAME);
 203         unbecome_root();
 204
 205         return ret;
 206 }
 207
 208
 209 static struct vfs_fn_pointers vfs_acl_xattr_fns = {
 210         .mkdir = mkdir_acl_common,
 211         .open = open_acl_common,
 212         .fget_nt_acl = fget_nt_acl_common,
 213         .get_nt_acl = get_nt_acl_common,
 214         .fset_nt_acl = fset_nt_acl_common,
 215         .sys_acl_set_file = sys_acl_set_file_xattr,
 216         .sys_acl_set_fd = sys_acl_set_fd_xattr
 217 };
 218
 219 NTSTATUS vfs_acl_xattr_init(void)
 220 {
 221         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "acl_xattr",
 222                                 &vfs_acl_xattr_fns);
 223 }