Line data    Source code

       1             : /*
       2             :  * Module to work around a bug in Linux XFS:
       3             :  * http://oss.sgi.com/bugzilla/show_bug.cgi?id=280
       4             :  *
       5             :  * Copyright (c) Volker Lendecke 2010
       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             : #include "includes.h"
      22             : #include "system/filesys.h"
      23             : #include "smbd/smbd.h"
      24             : 
      25           0 : static int linux_xfs_sgid_mkdirat(vfs_handle_struct *handle,
      26             :                 struct files_struct *dirfsp,
      27             :                 const struct smb_filename *smb_fname,
      28             :                 mode_t mode)
      29             : {
      30           0 :         struct smb_filename *dname = NULL;
      31           0 :         struct smb_filename *fname = NULL;
      32             :         int mkdir_res;
      33             :         int res;
      34             :         NTSTATUS status;
      35             : 
      36           0 :         DEBUG(10, ("Calling linux_xfs_sgid_mkdirat(%s)\n",
      37             :                 smb_fname->base_name));
      38             : 
      39           0 :         mkdir_res = SMB_VFS_NEXT_MKDIRAT(handle,
      40             :                         dirfsp,
      41             :                         smb_fname,
      42             :                         mode);
      43           0 :         if (mkdir_res == -1) {
      44           0 :                 DEBUG(10, ("SMB_VFS_NEXT_MKDIRAT returned error: %s\n",
      45             :                            strerror(errno)));
      46           0 :                 return mkdir_res;
      47             :         }
      48             : 
      49           0 :         fname = full_path_from_dirfsp_atname(talloc_tos(),
      50             :                                              dirfsp,
      51             :                                              smb_fname);
      52           0 :         if (fname == NULL) {
      53           0 :                 return -1;
      54             :         }
      55             : 
      56           0 :         status = SMB_VFS_PARENT_PATHNAME(handle->conn,
      57             :                                          talloc_tos(),
      58             :                                          fname,
      59             :                                          &dname,
      60             :                                          NULL);
      61           0 :         if (!NT_STATUS_IS_OK(status)) {
      62           0 :                 DBG_WARNING("SMB_VFS_PARENT_PATHNAME() failed with %s\n",
      63             :                         nt_errstr(status));
      64             :                 /* return success, we did the mkdir */
      65           0 :                 return mkdir_res;
      66             :         }
      67             : 
      68           0 :         res = SMB_VFS_NEXT_STAT(handle, dname);
      69           0 :         if (res == -1) {
      70           0 :                 DBG_DEBUG("NEXT_STAT(%s) failed: %s\n",
      71             :                           smb_fname_str_dbg(dname),
      72             :                           strerror(errno));
      73             :                 /* return success, we did the mkdir */
      74           0 :                 return mkdir_res;
      75             :         }
      76           0 :         if ((dname->st.st_ex_mode & S_ISGID) == 0) {
      77             :                 /* No SGID to inherit */
      78           0 :                 DEBUG(10, ("No SGID to inherit\n"));
      79           0 :                 TALLOC_FREE(dname);
      80           0 :                 return mkdir_res;
      81             :         }
      82           0 :         TALLOC_FREE(dname);
      83             : 
      84           0 :         res = SMB_VFS_NEXT_STAT(handle, fname);
      85           0 :         if (res == -1) {
      86           0 :                 DBG_NOTICE("Could not stat just created dir %s: %s\n",
      87             :                            smb_fname_str_dbg(fname),
      88             :                            strerror(errno));
      89             :                 /* return success, we did the mkdir */
      90           0 :                 TALLOC_FREE(fname);
      91           0 :                 return mkdir_res;
      92             :         }
      93           0 :         fname->st.st_ex_mode |= S_ISGID;
      94           0 :         fname->st.st_ex_mode &= ~S_IFDIR;
      95             : 
      96             :         /*
      97             :          * Yes, we have to do this as root. If you do it as
      98             :          * non-privileged user, XFS on Linux will just ignore us and
      99             :          * return success. What can you do...
     100             :          */
     101           0 :         become_root();
     102           0 :         res = SMB_VFS_NEXT_FCHMOD(handle, smb_fname->fsp, fname->st.st_ex_mode);
     103           0 :         unbecome_root();
     104             : 
     105           0 :         if (res == -1) {
     106           0 :                 DBG_NOTICE("CHMOD(%s, %o) failed: %s\n",
     107             :                            smb_fname_str_dbg(fname),
     108             :                            (int)fname->st.st_ex_mode,
     109             :                            strerror(errno));
     110             :                 /* return success, we did the mkdir */
     111           0 :                 TALLOC_FREE(fname);
     112           0 :                 return mkdir_res;
     113             :         }
     114             : 
     115           0 :         TALLOC_FREE(fname);
     116           0 :         return mkdir_res;
     117             : }
     118             : 
     119             : static struct vfs_fn_pointers linux_xfs_sgid_fns = {
     120             :         .mkdirat_fn = linux_xfs_sgid_mkdirat,
     121             : };
     122             : 
     123             : static_decl_vfs;
     124          27 : NTSTATUS vfs_linux_xfs_sgid_init(TALLOC_CTX *ctx)
     125             : {
     126          27 :         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
     127             :                                 "linux_xfs_sgid", &linux_xfs_sgid_fns);
     128             : }