source3/modules/vfs_linux_xfs_sgid.c

   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
  23 static int linux_xfs_sgid_mkdir(vfs_handle_struct *handle,  const char *path, mode_t mode)
  24 {
  25         struct smb_filename fname = { 0, };
  26         int mkdir_res;
  27         int res;
  28
  29         DEBUG(10, ("Calling linux_xfs_sgid_mkdir(%s)\n", path));
  30
  31         mkdir_res = SMB_VFS_NEXT_MKDIR(handle, path, mode);
  32         if (mkdir_res == -1) {
  33                 DEBUG(10, ("SMB_VFS_NEXT_MKDIR returned error: %s\n",
  34                            strerror(errno)));
  35                 return mkdir_res;
  36         }
  37
  38         if (!parent_dirname(talloc_tos(), path, &fname.base_name, NULL)) {
  39                 DEBUG(1, ("parent_dirname failed\n"));
  40                 /* return success, we did the mkdir */
  41                 return mkdir_res;
  42         }
  43
  44         res = SMB_VFS_NEXT_STAT(handle, &fname);
  45         if (res == -1) {
  46                 DEBUG(10, ("NEXT_STAT(%s) failed: %s\n", fname.base_name,
  47                            strerror(errno)));
  48                 /* return success, we did the mkdir */
  49                 return mkdir_res;
  50         }
  51         TALLOC_FREE(fname.base_name);
  52         if ((fname.st.st_ex_mode & S_ISGID) == 0) {
  53                 /* No SGID to inherit */
  54                 DEBUG(10, ("No SGID to inherit\n"));
  55                 return mkdir_res;
  56         }
  57
  58         fname.base_name = discard_const_p(char, path);
  59
  60         res = SMB_VFS_NEXT_STAT(handle, &fname);
  61         if (res == -1) {
  62                 DEBUG(2, ("Could not stat just created dir %s: %s\n", path,
  63                           strerror(errno)));
  64                 /* return success, we did the mkdir */
  65                 return mkdir_res;
  66         }
  67         fname.st.st_ex_mode |= S_ISGID;
  68         fname.st.st_ex_mode &= ~S_IFDIR;
  69
  70         /*
  71          * Yes, we have to do this as root. If you do it as
  72          * non-privileged user, XFS on Linux will just ignore us and
  73          * return success. What can you do...
  74          */
  75         become_root();
  76         res = SMB_VFS_NEXT_CHMOD(handle, path, fname.st.st_ex_mode);
  77         unbecome_root();
  78
  79         if (res == -1) {
  80                 DEBUG(2, ("CHMOD(%s, %o) failed: %s\n", path,
  81                           (int)fname.st.st_ex_mode, strerror(errno)));
  82                 /* return success, we did the mkdir */
  83                 return mkdir_res;
  84         }
  85         return mkdir_res;
  86 }
  87
  88 static int linux_xfs_sgid_chmod_acl(vfs_handle_struct *handle,
  89                                     const char *name, mode_t mode)
  90 {
  91         errno = ENOSYS;
  92         return -1;
  93 }
  94
  95 static struct vfs_fn_pointers linux_xfs_sgid_fns = {
  96         .mkdir = linux_xfs_sgid_mkdir,
  97         .chmod_acl = linux_xfs_sgid_chmod_acl,
  98 };
  99
 100 NTSTATUS vfs_linux_xfs_sgid_init(void);
 101 NTSTATUS vfs_linux_xfs_sgid_init(void)
 102 {
 103         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
 104                                 "linux_xfs_sgid", &linux_xfs_sgid_fns);
 105 }