1# acl.m4 - check for access control list (ACL) primitives
2# serial 24
3
4# Copyright (C) 2002, 2004-2021 Free Software Foundation, Inc.
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9# Written by Paul Eggert and Jim Meyering.
10
11AC_DEFUN([gl_FUNC_ACL_ARG],
12[
13  gl_need_lib_has_acl=
14  AC_ARG_ENABLE([acl],
15    AS_HELP_STRING([--disable-acl], [do not support ACLs]),
16    , [enable_acl=auto])
17])
18
19
20AC_DEFUN([gl_FUNC_ACL],
21[
22  AC_REQUIRE([gl_FUNC_ACL_ARG])
23  AC_CHECK_FUNCS_ONCE([fchmod])
24  LIB_ACL=
25  use_acl=0
26  if test "$enable_acl" != no; then
27    dnl On all platforms, the ACL related API is declared in <sys/acl.h>.
28    AC_CHECK_HEADERS([sys/acl.h])
29    if test $ac_cv_header_sys_acl_h = yes; then
30      ac_save_LIBS=$LIBS
31
32      dnl Test for POSIX-draft-like API (GNU/Linux, FreeBSD, Mac OS X,
33      dnl IRIX, Tru64, Cygwin >= 2.5).
34      dnl -lacl is needed on GNU/Linux, -lpacl on OSF/1.
35      if test $use_acl = 0; then
36        AC_SEARCH_LIBS([acl_get_file], [acl pacl],
37          [if test "$ac_cv_search_acl_get_file" != "none required"; then
38             LIB_ACL=$ac_cv_search_acl_get_file
39           fi
40           AC_CHECK_FUNCS(
41             [acl_get_file acl_get_fd acl_set_file acl_set_fd \
42              acl_free acl_from_mode acl_from_text \
43              acl_delete_def_file acl_extended_file \
44              acl_delete_fd_np acl_delete_file_np \
45              acl_copy_ext_native acl_create_entry_np \
46              acl_to_short_text acl_free_text])
47           # If the acl_get_file bug is detected, don't enable the ACL support.
48           gl_ACL_GET_FILE([use_acl=1], [])
49           if test $use_acl = 1; then
50             dnl On GNU/Linux, an additional API is declared in <acl/libacl.h>.
51             AC_CHECK_HEADERS([acl/libacl.h])
52             AC_REPLACE_FUNCS([acl_entries])
53             AC_CACHE_CHECK([for ACL_FIRST_ENTRY],
54               [gl_cv_acl_ACL_FIRST_ENTRY],
55               [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
56[[#include <sys/types.h>
57#include <sys/acl.h>
58int type = ACL_FIRST_ENTRY;]])],
59                  [gl_cv_acl_ACL_FIRST_ENTRY=yes],
60                  [gl_cv_acl_ACL_FIRST_ENTRY=no])])
61             if test $gl_cv_acl_ACL_FIRST_ENTRY = yes; then
62               AC_DEFINE([HAVE_ACL_FIRST_ENTRY], [1],
63                 [Define to 1 if the constant ACL_FIRST_ENTRY exists.])
64             fi
65             dnl On Mac OS X, other types of ACLs are supported.
66             AC_CACHE_CHECK([for ACL_TYPE_EXTENDED],
67               [gl_cv_acl_ACL_TYPE_EXTENDED],
68               [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
69[[#include <sys/types.h>
70#include <sys/acl.h>
71int type = ACL_TYPE_EXTENDED;]])],
72                  [gl_cv_acl_ACL_TYPE_EXTENDED=yes],
73                  [gl_cv_acl_ACL_TYPE_EXTENDED=no])])
74             if test $gl_cv_acl_ACL_TYPE_EXTENDED = yes; then
75               AC_DEFINE([HAVE_ACL_TYPE_EXTENDED], [1],
76                 [Define to 1 if the ACL type ACL_TYPE_EXTENDED exists.])
77             fi
78           else
79             LIB_ACL=
80           fi
81          ])
82      fi
83
84      dnl Test for Solaris API (Solaris, Cygwin).
85      if test $use_acl = 0; then
86        AC_CHECK_FUNCS([facl])
87        if test $ac_cv_func_facl = yes; then
88          AC_SEARCH_LIBS([acl_trivial], [sec],
89            [if test "$ac_cv_search_acl_trivial" != "none required"; then
90               LIB_ACL=$ac_cv_search_acl_trivial
91             fi
92            ])
93          AC_CHECK_FUNCS([acl_trivial])
94          use_acl=1
95        fi
96      fi
97
98      dnl Test for HP-UX API.
99      if test $use_acl = 0; then
100        AC_CHECK_FUNCS([getacl])
101        if test $ac_cv_func_getacl = yes; then
102          use_acl=1
103        fi
104        dnl Test for HP-UX 11.11 API.
105        AC_CHECK_HEADERS([aclv.h], [], [], [#include <sys/types.h>])
106      fi
107
108      dnl Test for AIX API (AIX 5.3 or newer).
109      if test $use_acl = 0; then
110        AC_CHECK_FUNCS([aclx_get])
111        if test $ac_cv_func_aclx_get = yes; then
112          use_acl=1
113        fi
114      fi
115
116      dnl Test for older AIX API.
117      if test $use_acl = 0 || test "$ac_cv_func_aclx_get" = yes; then
118        AC_CHECK_FUNCS([statacl])
119        if test $ac_cv_func_statacl = yes; then
120          use_acl=1
121        fi
122      fi
123
124      dnl Test for NonStop Kernel API.
125      if test $use_acl = 0; then
126        AC_CHECK_FUNCS([aclsort])
127        if test $ac_cv_func_aclsort = yes; then
128          use_acl=1
129        fi
130      fi
131
132      LIBS=$ac_save_LIBS
133    fi
134
135    if test "$enable_acl$use_acl" = yes0; then
136      AC_MSG_ERROR([ACLs enabled but support not detected])
137    elif test "$enable_acl$use_acl" = auto0; then
138      AC_MSG_WARN([libacl development library was not found or not usable.])
139      AC_MSG_WARN([AC_PACKAGE_NAME will be built without ACL support.])
140    fi
141  fi
142  test -n "$gl_need_lib_has_acl" && LIB_HAS_ACL=$LIB_ACL
143  AC_SUBST([LIB_ACL])
144  AC_DEFINE_UNQUOTED([USE_ACL], [$use_acl],
145    [Define to nonzero if you want access control list support.])
146  USE_ACL=$use_acl
147  AC_SUBST([USE_ACL])
148])
149
150# gl_ACL_GET_FILE(IF-WORKS, IF-NOT)
151# ---------------------------------
152# If 'acl_get_file' works (does not have a particular bug),
153# run IF-WORKS, otherwise, IF-NOT.
154# When building natively, test for a Darwin 8.7.0 bug, whereby acl_get_file
155# returns NULL, but sets errno = ENOENT for an existing file or directory.
156# When cross-compiling, assume that this old bug no longer applies.
157AC_DEFUN([gl_ACL_GET_FILE],
158[
159  AC_CACHE_CHECK([for working acl_get_file], [gl_cv_func_working_acl_get_file],
160    [gl_cv_func_working_acl_get_file=no
161     AC_LINK_IFELSE(
162       [AC_LANG_PROGRAM(
163          [[#include <sys/types.h>
164           #include <sys/acl.h>
165           #include <errno.h>
166          ]],
167          [[acl_t acl = acl_get_file (".", ACL_TYPE_ACCESS);
168            return acl ? acl_free (acl) != 0 : errno == ENOENT;
169          ]])],
170       [if test $cross_compiling = yes; then
171          gl_cv_func_working_acl_get_file="guessing yes"
172        elif ./conftest$ac_exeext; then
173          gl_cv_func_working_acl_get_file=yes
174        fi])])
175  AS_IF([test "$gl_cv_func_working_acl_get_file" != no], [$1], [$2])
176])
177
178# On GNU/Linux, testing if a file has an acl can be done with the getxattr
179# syscall which doesn't require linking against additional libraries.
180AC_DEFUN([gl_FILE_HAS_ACL],
181[
182  AC_REQUIRE([gl_FUNC_ACL_ARG])
183  if test "$enable_acl" != no; then
184    AC_CACHE_CHECK([for getxattr with XATTR_NAME_POSIX_ACL macros],
185      [gl_cv_getxattr_with_posix_acls],
186      [gl_cv_getxattr_with_posix_acls=no
187       AC_LINK_IFELSE(
188         [AC_LANG_PROGRAM(
189            [[#include <sys/types.h>
190              #include <sys/xattr.h>
191              #include <linux/xattr.h>
192            ]],
193            [[ssize_t a = getxattr (".", XATTR_NAME_POSIX_ACL_ACCESS, 0, 0);
194              ssize_t b = getxattr (".", XATTR_NAME_POSIX_ACL_DEFAULT, 0, 0);
195              return a < 0 || b < 0;
196            ]])],
197         [gl_cv_getxattr_with_posix_acls=yes])])
198  fi
199  if test "$gl_cv_getxattr_with_posix_acls" = yes; then
200    LIB_HAS_ACL=
201    AC_DEFINE([GETXATTR_WITH_POSIX_ACLS], 1,
202      [Define to 1 if getxattr works with XATTR_NAME_POSIX_ACL_ACCESS
203       and XATTR_NAME_POSIX_ACL_DEFAULT.])
204  else
205    dnl Set gl_need_lib_has_acl to a nonempty value, so that any
206    dnl later gl_FUNC_ACL call will set LIB_HAS_ACL=$LIB_ACL.
207    gl_need_lib_has_acl=1
208    LIB_HAS_ACL=$LIB_ACL
209  fi
210  AC_SUBST([LIB_HAS_ACL])
211])
212