source: trunk/server/source3/modules/vfs_linux_xfs_sgid.c@ 953

/*
 * Module to work around a bug in Linux XFS:
 * http://oss.sgi.com/bugzilla/show_bug.cgi?id=280
 *
 * Copyright (c) Volker Lendecke 2010
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "includes.h"
#include "system/filesys.h"
#include "smbd/smbd.h"

static int linux_xfs_sgid_mkdir(vfs_handle_struct *handle,  const char *path, mode_t mode)
{
        struct smb_filename fname = { 0, };
        int mkdir_res;
        int res;

        DEBUG(10, ("Calling linux_xfs_sgid_mkdir(%s)\n", path));

        mkdir_res = SMB_VFS_NEXT_MKDIR(handle, path, mode);
        if (mkdir_res == -1) {
                DEBUG(10, ("SMB_VFS_NEXT_MKDIR returned error: %s\n",
                           strerror(errno)));
                return mkdir_res;
        }

        if (!parent_dirname(talloc_tos(), path, &fname.base_name, NULL)) {
                DEBUG(1, ("parent_dirname failed\n"));
                /* return success, we did the mkdir */
                return mkdir_res;
        }

        res = SMB_VFS_NEXT_STAT(handle, &fname);
        if (res == -1) {
                DEBUG(10, ("NEXT_STAT(%s) failed: %s\n", fname.base_name,
                           strerror(errno)));
                /* return success, we did the mkdir */
                return mkdir_res;
        }
        TALLOC_FREE(fname.base_name);
        if ((fname.st.st_ex_mode & S_ISGID) == 0) {
                /* No SGID to inherit */
                DEBUG(10, ("No SGID to inherit\n"));
                return mkdir_res;
        }

        fname.base_name = discard_const_p(char, path);

        res = SMB_VFS_NEXT_STAT(handle, &fname);
        if (res == -1) {
                DEBUG(2, ("Could not stat just created dir %s: %s\n", path,
                          strerror(errno)));
                /* return success, we did the mkdir */
                return mkdir_res;
        }
        fname.st.st_ex_mode |= S_ISGID;
        fname.st.st_ex_mode &= ~S_IFDIR;

        /*
         * Yes, we have to do this as root. If you do it as
         * non-privileged user, XFS on Linux will just ignore us and
         * return success. What can you do...
         */
        become_root();
        res = SMB_VFS_NEXT_CHMOD(handle, path, fname.st.st_ex_mode);
        unbecome_root();

        if (res == -1) {
                DEBUG(2, ("CHMOD(%s, %o) failed: %s\n", path,
                          (int)fname.st.st_ex_mode, strerror(errno)));
                /* return success, we did the mkdir */
                return mkdir_res;
        }
        return mkdir_res;
}

static int linux_xfs_sgid_chmod_acl(vfs_handle_struct *handle,
                                    const char *name, mode_t mode)
{
        errno = ENOSYS;
        return -1;
}

static struct vfs_fn_pointers linux_xfs_sgid_fns = {
        .mkdir = linux_xfs_sgid_mkdir,
        .chmod_acl = linux_xfs_sgid_chmod_acl,
};

NTSTATUS vfs_linux_xfs_sgid_init(void);
NTSTATUS vfs_linux_xfs_sgid_init(void)
{
        return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
                                "linux_xfs_sgid", &linux_xfs_sgid_fns);
}