mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-11-22 07:09:54 +00:00
105 lines
3.8 KiB
C
105 lines
3.8 KiB
C
/* Copy access control list from one file to another. -*- coding: utf-8 -*-
|
|
|
|
Copyright (C) 2002-2003, 2005-2024 Free Software Foundation, Inc.
|
|
|
|
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 <https://www.gnu.org/licenses/>.
|
|
|
|
Written by Paul Eggert, Andreas Grünbacher, and Bruno Haible. */
|
|
|
|
#include <config.h>
|
|
|
|
#include "acl.h"
|
|
|
|
#include "acl-internal.h"
|
|
|
|
#if USE_XATTR
|
|
|
|
# include <attr/libattr.h>
|
|
# include <string.h>
|
|
|
|
# if HAVE_LINUX_XATTR_H
|
|
# include <linux/xattr.h>
|
|
# endif
|
|
# ifndef XATTR_NAME_NFSV4_ACL
|
|
# define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
|
|
# endif
|
|
# ifndef XATTR_NAME_POSIX_ACL_ACCESS
|
|
# define XATTR_NAME_POSIX_ACL_ACCESS "system.posix_acl_access"
|
|
# endif
|
|
# ifndef XATTR_NAME_POSIX_ACL_DEFAULT
|
|
# define XATTR_NAME_POSIX_ACL_DEFAULT "system.posix_acl_default"
|
|
# endif
|
|
|
|
/* Returns 1 if NAME is the name of an extended attribute that is related
|
|
to permissions, i.e. ACLs. Returns 0 otherwise. */
|
|
|
|
static int
|
|
is_attr_permissions (const char *name, struct error_context *ctx)
|
|
{
|
|
/* We need to explicitly test for the known extended attribute names,
|
|
because at least on CentOS 7, attr_copy_action does not do it. */
|
|
return strcmp (name, XATTR_NAME_POSIX_ACL_ACCESS) == 0
|
|
|| strcmp (name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0
|
|
|| strcmp (name, XATTR_NAME_NFSV4_ACL) == 0
|
|
|| attr_copy_action (name, ctx) == ATTR_ACTION_PERMISSIONS;
|
|
}
|
|
|
|
#endif /* USE_XATTR */
|
|
|
|
/* Copy access control lists from one file to another. If SOURCE_DESC is
|
|
a valid file descriptor, use file descriptor operations, else use
|
|
filename based operations on SRC_NAME. Likewise for DEST_DESC and
|
|
DST_NAME.
|
|
If access control lists are not available, fchmod the target file to
|
|
MODE. Also sets the non-permission bits of the destination file
|
|
(S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set.
|
|
Return 0 if successful.
|
|
Return -2 and set errno for an error relating to the source file.
|
|
Return -1 and set errno for an error relating to the destination file. */
|
|
|
|
int
|
|
qcopy_acl (const char *src_name, int source_desc, const char *dst_name,
|
|
int dest_desc, mode_t mode)
|
|
{
|
|
int ret;
|
|
|
|
#ifdef USE_XATTR
|
|
/* in case no ACLs present and also to set higher mode bits
|
|
we chmod before setting ACLs as doing it after could overwrite them
|
|
(especially true for NFSv4, posix ACL has that ugly "mask" hack that
|
|
nobody understands) */
|
|
ret = chmod_or_fchmod (dst_name, dest_desc, mode);
|
|
/* Rather than fiddling with acls one by one, we just copy the whole ACL xattrs
|
|
(Posix or NFSv4). Of course, that won't address ACLs conversion
|
|
(i.e. posix <-> nfs4) but we can't do it anyway, so for now, we don't care
|
|
Functions attr_copy_* return 0 in case we copied something OR nothing
|
|
to copy */
|
|
if (ret == 0)
|
|
ret = source_desc <= 0 || dest_desc <= 0
|
|
? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL)
|
|
: attr_copy_fd (src_name, source_desc, dst_name, dest_desc,
|
|
is_attr_permissions, NULL);
|
|
#else
|
|
/* no XATTR, so we proceed the old dusty way */
|
|
struct permission_context ctx;
|
|
|
|
ret = get_permissions (src_name, source_desc, mode, &ctx);
|
|
if (ret != 0)
|
|
return -2;
|
|
ret = set_permissions (&ctx, dst_name, dest_desc);
|
|
free_permission_context (&ctx);
|
|
#endif
|
|
return ret;
|
|
}
|