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 /* Pull in the common functions. */
  32 #include "modules/vfs_acl_common.c"
  33
  34 /*******************************************************************
  35  Pull a security descriptor into a DATA_BLOB from a xattr.
  36 *******************************************************************/
  37
  38 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  39                         vfs_handle_struct *handle,
  40                         files_struct *fsp,
  41                         const char *name,
  42                         DATA_BLOB *pblob)
  43 {
  44         size_t size = 1024;
  45         uint8_t *val = NULL;
  46         uint8_t *tmp;
  47         ssize_t sizeret;
  48         int saved_errno = 0;
  49
  50         ZERO_STRUCTP(pblob);
  51
  52   again:
  53
  54         tmp = TALLOC_REALLOC_ARRAY(ctx, val, uint8_t, size);
  55         if (tmp == NULL) {
  56                 TALLOC_FREE(val);
  57                 return NT_STATUS_NO_MEMORY;
  58         }
  59         val = tmp;
  60
  61         become_root();
  62         if (fsp && fsp->fh->fd != -1) {
  63                 sizeret = SMB_VFS_FGETXATTR(fsp, XATTR_NTACL_NAME, val, size);
  64         } else {
  65                 sizeret = SMB_VFS_GETXATTR(handle->conn, name,
  66                                         XATTR_NTACL_NAME, val, size);
  67         }
  68         if (sizeret == -1) {
  69                 saved_errno = errno;
  70         }
  71         unbecome_root();
  72
  73         /* Max ACL size is 65536 bytes. */
  74         if (sizeret == -1) {
  75                 errno = saved_errno;
  76                 if ((errno == ERANGE) && (size != 65536)) {
  77                         /* Too small, try again. */
  78                         size = 65536;
  79                         goto again;
  80                 }
  81
  82                 /* Real error - exit here. */
  83                 TALLOC_FREE(val);
  84                 return map_nt_error_from_unix(errno);
  85         }
  86
  87         pblob->data = val;
  88         pblob->length = sizeret;
  89         return NT_STATUS_OK;
  90 }
  91
  92 /*******************************************************************
  93  Store a DATA_BLOB into an xattr given an fsp pointer.
  94 *******************************************************************/
  95
  96 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  97                                 files_struct *fsp,
  98                                 DATA_BLOB *pblob)
  99 {
 100         int ret;
 101         int saved_errno = 0;
 102
 103         DEBUG(10,("store_acl_blob_fsp: storing blob length %u on file %s\n",
 104                   (unsigned int)pblob->length, fsp_str_dbg(fsp)));
 105
 106         become_root();
 107         if (fsp->fh->fd != -1) {
 108                 ret = SMB_VFS_FSETXATTR(fsp, XATTR_NTACL_NAME,
 109                         pblob->data, pblob->length, 0);
 110         } else {
 111                 ret = SMB_VFS_SETXATTR(fsp->conn, fsp->fsp_name->base_name,
 112                                 XATTR_NTACL_NAME,
 113                                 pblob->data, pblob->length, 0);
 114         }
 115         if (ret) {
 116                 saved_errno = errno;
 117         }
 118         unbecome_root();
 119         if (ret) {
 120                 errno = saved_errno;
 121                 DEBUG(5, ("store_acl_blob_fsp: setting attr failed for file %s"
 122                         "with error %s\n",
 123                         fsp_str_dbg(fsp),
 124                         strerror(errno) ));
 125                 return map_nt_error_from_unix(errno);
 126         }
 127         return NT_STATUS_OK;
 128 }
 129
 130 /*******************************************************************
 131  Store a DATA_BLOB into an xattr given a pathname.
 132 *******************************************************************/
 133
 134 static NTSTATUS store_acl_blob_pathname(vfs_handle_struct *handle,
 135                                         const char *fname,
 136                                         DATA_BLOB *pblob)
 137 {
 138         connection_struct *conn = handle->conn;
 139         int ret;
 140         int saved_errno = 0;
 141
 142         DEBUG(10,("store_acl_blob_pathname: storing blob "
 143                         "length %u on file %s\n",
 144                         (unsigned int)pblob->length, fname));
 145
 146         become_root();
 147         ret = SMB_VFS_SETXATTR(conn, fname,
 148                                 XATTR_NTACL_NAME,
 149                                 pblob->data, pblob->length, 0);
 150         if (ret) {
 151                 saved_errno = errno;
 152         }
 153         unbecome_root();
 154         if (ret) {
 155                 errno = saved_errno;
 156                 DEBUG(5, ("store_acl_blob_pathname: setting attr failed "
 157                         "for file %s with error %s\n",
 158                         fname,
 159                         strerror(errno) ));
 160                 return map_nt_error_from_unix(errno);
 161         }
 162         return NT_STATUS_OK;
 163 }
 164
 165 /*********************************************************************
 166  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 167 *********************************************************************/
 168
 169 static int sys_acl_set_file_xattr(vfs_handle_struct *handle,
 170                               const char *name,
 171                               SMB_ACL_TYPE_T type,
 172                               SMB_ACL_T theacl)
 173 {
 174         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FILE(handle,
 175                                                 name,
 176                                                 type,
 177                                                 theacl);
 178         if (ret == -1) {
 179                 return -1;
 180         }
 181
 182         become_root();
 183         SMB_VFS_REMOVEXATTR(handle->conn, name, XATTR_NTACL_NAME);
 184         unbecome_root();
 185
 186         return ret;
 187 }
 188
 189 /*********************************************************************
 190  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 191 *********************************************************************/
 192
 193 static int sys_acl_set_fd_xattr(vfs_handle_struct *handle,
 194                             files_struct *fsp,
 195                             SMB_ACL_T theacl)
 196 {
 197         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FD(handle,
 198                                                 fsp,
 199                                                 theacl);
 200         if (ret == -1) {
 201                 return -1;
 202         }
 203
 204         become_root();
 205         SMB_VFS_FREMOVEXATTR(fsp, XATTR_NTACL_NAME);
 206         unbecome_root();
 207
 208         return ret;
 209 }
 210
 211
 212 static struct vfs_fn_pointers vfs_acl_xattr_fns = {
 213         .mkdir = mkdir_acl_common,
 214         .open = open_acl_common,
 215         .fget_nt_acl = fget_nt_acl_common,
 216         .get_nt_acl = get_nt_acl_common,
 217         .fset_nt_acl = fset_nt_acl_common,
 218         .sys_acl_set_file = sys_acl_set_file_xattr,
 219         .sys_acl_set_fd = sys_acl_set_fd_xattr
 220 };
 221
 222 NTSTATUS vfs_acl_xattr_init(void)
 223 {
 224         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "acl_xattr",
 225                                 &vfs_acl_xattr_fns);
 226 }