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 #define ACL_MODULE_NAME "acl_xattr"
  33
  34 #include "modules/vfs_acl_common.c"
  35
  36 /*******************************************************************
  37  Pull a security descriptor into a DATA_BLOB from a xattr.
  38 *******************************************************************/
  39
  40 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  41                         vfs_handle_struct *handle,
  42                         files_struct *fsp,
  43                         const char *name,
  44                         DATA_BLOB *pblob)
  45 {
  46         size_t size = 1024;
  47         uint8_t *val = NULL;
  48         uint8_t *tmp;
  49         ssize_t sizeret;
  50         int saved_errno = 0;
  51
  52         ZERO_STRUCTP(pblob);
  53
  54   again:
  55
  56         tmp = TALLOC_REALLOC_ARRAY(ctx, val, uint8_t, size);
  57         if (tmp == NULL) {
  58                 TALLOC_FREE(val);
  59                 return NT_STATUS_NO_MEMORY;
  60         }
  61         val = tmp;
  62
  63         become_root();
  64         if (fsp && fsp->fh->fd != -1) {
  65                 sizeret = SMB_VFS_FGETXATTR(fsp, XATTR_NTACL_NAME, val, size);
  66         } else {
  67                 sizeret = SMB_VFS_GETXATTR(handle->conn, name,
  68                                         XATTR_NTACL_NAME, val, size);
  69         }
  70         if (sizeret == -1) {
  71                 saved_errno = errno;
  72         }
  73         unbecome_root();
  74
  75         /* Max ACL size is 65536 bytes. */
  76         if (sizeret == -1) {
  77                 errno = saved_errno;
  78                 if ((errno == ERANGE) && (size != 65536)) {
  79                         /* Too small, try again. */
  80                         size = 65536;
  81                         goto again;
  82                 }
  83
  84                 /* Real error - exit here. */
  85                 TALLOC_FREE(val);
  86                 return map_nt_error_from_unix(errno);
  87         }
  88
  89         pblob->data = val;
  90         pblob->length = sizeret;
  91         return NT_STATUS_OK;
  92 }
  93
  94 /*******************************************************************
  95  Store a DATA_BLOB into an xattr given an fsp pointer.
  96 *******************************************************************/
  97
  98 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  99                                 files_struct *fsp,
 100                                 DATA_BLOB *pblob)
 101 {
 102         int ret;
 103         int saved_errno = 0;
 104
 105         DEBUG(10,("store_acl_blob_fsp: storing blob length %u on file %s\n",
 106                   (unsigned int)pblob->length, fsp_str_dbg(fsp)));
 107
 108         become_root();
 109         if (fsp->fh->fd != -1) {
 110                 ret = SMB_VFS_FSETXATTR(fsp, XATTR_NTACL_NAME,
 111                         pblob->data, pblob->length, 0);
 112         } else {
 113                 ret = SMB_VFS_SETXATTR(fsp->conn, fsp->fsp_name->base_name,
 114                                 XATTR_NTACL_NAME,
 115                                 pblob->data, pblob->length, 0);
 116         }
 117         if (ret) {
 118                 saved_errno = errno;
 119         }
 120         unbecome_root();
 121         if (ret) {
 122                 errno = saved_errno;
 123                 DEBUG(5, ("store_acl_blob_fsp: setting attr failed for file %s"
 124                         "with error %s\n",
 125                         fsp_str_dbg(fsp),
 126                         strerror(errno) ));
 127                 return map_nt_error_from_unix(errno);
 128         }
 129         return NT_STATUS_OK;
 130 }
 131
 132 /*********************************************************************
 133  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 134 *********************************************************************/
 135
 136 static int sys_acl_set_file_xattr(vfs_handle_struct *handle,
 137                               const char *name,
 138                               SMB_ACL_TYPE_T type,
 139                               SMB_ACL_T theacl)
 140 {
 141         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FILE(handle,
 142                                                 name,
 143                                                 type,
 144                                                 theacl);
 145         if (ret == -1) {
 146                 return -1;
 147         }
 148
 149         become_root();
 150         SMB_VFS_REMOVEXATTR(handle->conn, name, XATTR_NTACL_NAME);
 151         unbecome_root();
 152
 153         return ret;
 154 }
 155
 156 /*********************************************************************
 157  Remove a Windows ACL - we're setting the underlying POSIX ACL.
 158 *********************************************************************/
 159
 160 static int sys_acl_set_fd_xattr(vfs_handle_struct *handle,
 161                             files_struct *fsp,
 162                             SMB_ACL_T theacl)
 163 {
 164         int ret = SMB_VFS_NEXT_SYS_ACL_SET_FD(handle,
 165                                                 fsp,
 166                                                 theacl);
 167         if (ret == -1) {
 168                 return -1;
 169         }
 170
 171         become_root();
 172         SMB_VFS_FREMOVEXATTR(fsp, XATTR_NTACL_NAME);
 173         unbecome_root();
 174
 175         return ret;
 176 }
 177
 178 static int connect_acl_xattr(struct vfs_handle_struct *handle,
 179                                 const char *service,
 180                                 const char *user)
 181 {
 182         int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
 183
 184         if (ret < 0) {
 185                 return ret;
 186         }
 187
 188         /* Ensure we have the parameters correct if we're
 189          * using this module. */
 190         DEBUG(2,("connect_acl_xattr: setting 'inherit acls = true' "
 191                 "'dos filemode = true' and "
 192                 "'force unknown acl user = true' for service %s\n",
 193                 service ));
 194
 195         lp_do_parameter(SNUM(handle->conn), "inherit acls", "true");
 196         lp_do_parameter(SNUM(handle->conn), "dos filemode", "true");
 197         lp_do_parameter(SNUM(handle->conn), "force unknown acl user", "true");
 198
 199         return 0;
 200 }
 201
 202 static struct vfs_fn_pointers vfs_acl_xattr_fns = {
 203         .connect_fn = connect_acl_xattr,
 204         .opendir = opendir_acl_common,
 205         .mkdir = mkdir_acl_common,
 206         .rmdir = rmdir_acl_common,
 207         .open = open_acl_common,
 208         .create_file = create_file_acl_common,
 209         .unlink = unlink_acl_common,
 210         .fget_nt_acl = fget_nt_acl_common,
 211         .get_nt_acl = get_nt_acl_common,
 212         .fset_nt_acl = fset_nt_acl_common,
 213         .sys_acl_set_file = sys_acl_set_file_xattr,
 214         .sys_acl_set_fd = sys_acl_set_fd_xattr
 215 };
 216
 217 NTSTATUS vfs_acl_xattr_init(void)
 218 {
 219         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "acl_xattr",
 220                                 &vfs_acl_xattr_fns);
 221 }