about summary refs log tree commit diff
path: root/m4/check-libc.m4
blob: b33224f80c2bece7290adf0495b4cb45707b5773 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
AC_DEFUN([CHECK_LIBC_COMPAT], [
# Check for libc headers
AC_CHECK_HEADERS([netinet/ip.h], [], [],
[#include <sys/types.h>
#include <arpa/inet.h>
])
# Check for general libc functions
AC_CHECK_FUNCS([asprintf freezero memmem])
AC_CHECK_FUNCS([reallocarray recallocarray])
AC_CHECK_FUNCS([strlcat strlcpy strndup strnlen strsep strtonum])
AC_CHECK_FUNCS([timegm _mkgmtime timespecsub])
AC_CHECK_FUNCS([getprogname])
AC_CACHE_CHECK([for getpagesize], ac_cv_func_getpagesize, [
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <unistd.h>
		]], [[
	getpagesize();
]])],
	[ ac_cv_func_getpagesize="yes" ],
	[ ac_cv_func_getpagesize="no"
	])
])
AM_CONDITIONAL([HAVE_ASPRINTF], [test "x$ac_cv_func_asprintf" = xyes])
AM_CONDITIONAL([HAVE_FREEZERO], [test "x$ac_cv_func_freezero" = xyes])
AM_CONDITIONAL([HAVE_GETPAGESIZE], [test "x$ac_cv_func_getpagesize" = xyes])
AM_CONDITIONAL([HAVE_MEMMEM], [test "x$ac_cv_func_memmem" = xyes])
AM_CONDITIONAL([HAVE_REALLOCARRAY], [test "x$ac_cv_func_reallocarray" = xyes])
AM_CONDITIONAL([HAVE_RECALLOCARRAY], [test "x$ac_cv_func_recallocarray" = xyes])
AM_CONDITIONAL([HAVE_STRLCAT], [test "x$ac_cv_func_strlcat" = xyes])
AM_CONDITIONAL([HAVE_STRLCPY], [test "x$ac_cv_func_strlcpy" = xyes])
AM_CONDITIONAL([HAVE_STRNDUP], [test "x$ac_cv_func_strndup" = xyes])
AM_CONDITIONAL([HAVE_STRNLEN], [test "x$ac_cv_func_strnlen" = xyes])
AM_CONDITIONAL([HAVE_STRSEP], [test "x$ac_cv_func_strsep" = xyes])
AM_CONDITIONAL([HAVE_STRTONUM], [test "x$ac_cv_func_strtonum" = xyes])
AM_CONDITIONAL([HAVE_TIMEGM], [test "x$ac_cv_func_timegm" = xyes])
AM_CONDITIONAL([HAVE_GETPROGNAME], [test "x$ac_cv_func_getprogname" = xyes])
])

AC_DEFUN([CHECK_CRYPTO_COMPAT], [
# Check crypto-related libc functions and syscalls
AC_CHECK_FUNCS([arc4random arc4random_buf arc4random_uniform])
AC_CHECK_FUNCS([explicit_bzero getauxval])

AC_CACHE_CHECK([for getentropy], ac_cv_func_getentropy, [
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <sys/types.h>
#include <unistd.h>

/*
 * Explanation:
 *
 *   - iOS <= 10.1 fails because of missing sys/random.h
 *
 *   - in macOS 10.12 getentropy is not tagged as introduced in
 *     10.12 so we cannot use it for target < 10.12
 */
#ifdef __APPLE__
#  include <AvailabilityMacros.h>
#  include <TargetConditionals.h>

# if (TARGET_OS_IPHONE || TARGET_OS_SIMULATOR)
#  include <sys/random.h> /* Not available as of iOS <= 10.1 */
# else

#  include <sys/random.h> /* Pre 10.12 systems should die here */

/* Based on: https://gitweb.torproject.org/tor.git/commit/?id=16fcbd21 */
#  ifndef MAC_OS_X_VERSION_10_12
#    define MAC_OS_X_VERSION_10_12 101200 /* Robustness */
#  endif
#  if defined(MAC_OS_X_VERSION_MIN_REQUIRED)
#    if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_12
#      error "Targeting on Mac OSX 10.11 or earlier"
#    endif
#  endif

# endif
#endif /* __APPLE__ */
		]], [[
	char buffer;
	(void)getentropy(&buffer, sizeof (buffer));
]])],
	[ ac_cv_func_getentropy="yes" ],
	[ ac_cv_func_getentropy="no"
	])
])

AC_CHECK_FUNCS([timingsafe_bcmp timingsafe_memcmp])
AM_CONDITIONAL([HAVE_ARC4RANDOM], [test "x$ac_cv_func_arc4random" = xyes])
AM_CONDITIONAL([HAVE_ARC4RANDOM_BUF], [test "x$ac_cv_func_arc4random_buf" = xyes])
AM_CONDITIONAL([HAVE_ARC4RANDOM_UNIFORM], [test "x$ac_cv_func_arc4random_uniform" = xyes])
AM_CONDITIONAL([HAVE_EXPLICIT_BZERO], [test "x$ac_cv_func_explicit_bzero" = xyes])
AM_CONDITIONAL([HAVE_GETENTROPY], [test "x$ac_cv_func_getentropy" = xyes])
AM_CONDITIONAL([HAVE_TIMINGSAFE_BCMP], [test "x$ac_cv_func_timingsafe_bcmp" = xyes])
AM_CONDITIONAL([HAVE_TIMINGSAFE_MEMCMP], [test "x$ac_cv_func_timingsafe_memcmp" = xyes])

# Override arc4random_buf implementations with known issues
AM_CONDITIONAL([HAVE_ARC4RANDOM_BUF],
	[test "x$USE_BUILTIN_ARC4RANDOM" != xyes \
	   -a "x$ac_cv_func_arc4random_buf" = xyes])

# Check for getentropy fallback dependencies
AC_CHECK_FUNCS([getauxval])
AC_SEARCH_LIBS([dl_iterate_phdr],[dl])
AC_CHECK_FUNCS([dl_iterate_phdr])

AC_SEARCH_LIBS([pthread_once],[pthread])
AC_SEARCH_LIBS([pthread_mutex_lock],[pthread])
AC_SEARCH_LIBS([clock_gettime],[rt posix4])
AC_CHECK_FUNCS([clock_gettime])
AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "x$ac_cv_func_clock_gettime" = xyes])
])

AC_DEFUN([CHECK_VA_COPY], [
AC_CACHE_CHECK([whether va_copy exists], ac_cv_have_va_copy, [
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdarg.h>
va_list x,y;
		]], [[ va_copy(x,y); ]])],
	[ ac_cv_have_va_copy="yes" ],
	[ ac_cv_have_va_copy="no"
	])
])
if test "x$ac_cv_have_va_copy" = "xyes" ; then
	AC_DEFINE([HAVE_VA_COPY], [1], [Define if va_copy exists])
fi

AC_CACHE_CHECK([whether __va_copy exists], ac_cv_have___va_copy, [
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdarg.h>
va_list x,y;
		]], [[ __va_copy(x,y); ]])],
	[ ac_cv_have___va_copy="yes" ], [ ac_cv_have___va_copy="no"
	])
])
if test "x$ac_cv_have___va_copy" = "xyes" ; then
	AC_DEFINE([HAVE___VA_COPY], [1], [Define if __va_copy exists])
fi
])