Move local autoconf macros under m4 directory (#186)

ChangeLog

@@ -8,6 +8,11 @@
 	  mappings (4575 IAB + 5461 MAM + 35971 OUI + 6112 OUI36).
 	  https://github.com/royhills/arp-scan/pull/185
 
+	* configure.ac, m4/*: Move local autoconf macros from acinclude.m4
+	  to seperate files under m4/, which is specified with
+	  AC_CONFIG_MACRO_DIRS in configure.ac. configure.ac now requires
+	  at least autoconf 2.70 (was previously 2.69).
+
 2024-03-29 Roy Hills <[email protected]>
 
 	* arp-fingerprint: Added recent Windows and FreeBSD patterns.

configure.ac

@@ -1,9 +1,10 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_INIT([arp-scan],[1.10.1-git],[https://github.com/royhills/arp-scan])
-AC_PREREQ([2.69])
+AC_PREREQ([2.70])
 AC_CONFIG_SRCDIR([arp-scan.c])
 AC_CONFIG_AUX_DIR([build-aux])
+AC_CONFIG_MACRO_DIRS([m4])
 AM_INIT_AUTOMAKE
 
 AC_CONFIG_HEADERS([config.h])

m4/gcc-format-security.m4

@@ -0,0 +1,29 @@
+dnl Check for support of the GCC -Wformat-security option.
+dnl This option was introduced in GCC 3.0.
+dnl
+dnl Note that in this test, the test compilation fails if the option is
+dnl supported, and succeeds if it is not supported.
+dnl
+dnl If this option is supported, then the test program will produce a
+dnl warning like "format not a string literal and no format arguments".
+dnl If it is not supported, then the test program will compile without
+dnl warnings.
+dnl
+AC_DEFUN([GCC_FORMAT_SECURITY],[
+   if test "X$CC" != "X"; then
+      AC_MSG_CHECKING([whether ${CC} accepts -Wformat-security])
+      wfs_old_cflags="$CFLAGS"
+      CFLAGS="$CFLAGS -Wall -Werror -Wformat -Wformat-security"
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]], [[
+         char *fmt=NULL;
+         printf(fmt);
+         return 0;
+      ]])],[
+         AC_MSG_RESULT(no)
+         CFLAGS="$wfs_old_cflags"
+      ],[
+         AC_MSG_RESULT(yes)
+         CFLAGS="$wfs_old_cflags -Wformat -Wformat-security"
+      ])
+   fi
+])

m4/gcc-fortify-source.m4

@@ -0,0 +1,30 @@
+dnl Check whether GCC accepts -D_FORTIFY_SOURCE
+dnl
+dnl This was introduced in GCC 4.1 and glibc 2.4, but was present in earlier
+dnl versions on redhat systems (specifically GCC 3.4.3 and above).
+dnl
+dnl We define the GNUC_PREREQ macro to the same definition as __GNUC_PREREQ
+dnl in <features.h>. We don't use __GNUC_PREREQ directly because <features.h>
+dnl is not present on all the operating systems that we support, e.g. OpenBSD.
+dnl
+AC_DEFUN([GCC_FORTIFY_SOURCE],[
+   if test "X$CC" != "X"; then
+      AC_MSG_CHECKING([whether ${CC} accepts -D_FORTIFY_SOURCE])
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
+         #define GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+         #if !(GNUC_PREREQ (4, 1) \
+            || (defined __GNUC_RH_RELEASE__ && GNUC_PREREQ (4, 0)) \
+            || (defined __GNUC_RH_RELEASE__ && GNUC_PREREQ (3, 4) \
+               && __GNUC_MINOR__ == 4 \
+               && (__GNUC_PATCHLEVEL__ > 2 \
+                  || (__GNUC_PATCHLEVEL__ == 2 && __GNUC_RH_RELEASE__ >= 8))))
+         #error No FORTIFY_SOURCE support
+         #endif
+      ]])],[
+         AC_MSG_RESULT(yes)
+         CFLAGS="$CFLAGS -D_FORTIFY_SOURCE=2"
+      ],[
+         AC_MSG_RESULT(no)
+      ])
+   fi
+])

m4/gcc-stack-protect.m4

@@ -0,0 +1,53 @@
+dnl Useful macros for autoconf to check for ssp-patched gcc
+dnl 1.0 - September 2003 - Tiago Sousa <[email protected]>
+dnl
+dnl Modified by ffontaine pull request: use AC_LINK_IFELSE instead of
+dnl AC_COMPILE_IFELSE because some systems may be missing the libssp library
+dnl even though the compiler accepts the option.
+dnl
+dnl About ssp:
+dnl GCC extension for protecting applications from stack-smashing attacks
+dnl http://www.research.ibm.com/trl/projects/security/ssp/
+dnl
+dnl Usage:
+dnl After calling the correct AC_LANG_*, use the corresponding macro:
+dnl
+dnl GCC_STACK_PROTECT_CC
+dnl checks -fstack-protector with the C compiler, if it exists then updates
+dnl CFLAGS and defines ENABLE_SSP_CC
+dnl
+dnl GCC_STACK_PROTECT_CXX
+dnl checks -fstack-protector with the C++ compiler, if it exists then updates
+dnl CXXFLAGS and defines ENABLE_SSP_CXX
+dnl
+AC_DEFUN([GCC_STACK_PROTECT_CC],[
+  ssp_cc=yes
+  if test "X$CC" != "X"; then
+    AC_MSG_CHECKING([whether ${CC} accepts -fstack-protector])
+    ssp_old_cflags="$CFLAGS"
+    CFLAGS="$CFLAGS -fstack-protector"
+    AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[],[ssp_cc=no])
+    echo $ssp_cc
+    if test "X$ssp_cc" = "Xno"; then
+      CFLAGS="$ssp_old_cflags"
+    else
+      AC_DEFINE([ENABLE_SSP_CC], 1, [Define if SSP C support is enabled.])
+    fi
+  fi
+])
+
+AC_DEFUN([GCC_STACK_PROTECT_CXX],[
+  ssp_cxx=yes
+  if test "X$CXX" != "X"; then
+    AC_MSG_CHECKING([whether ${CXX} accepts -fstack-protector])
+    ssp_old_cxxflags="$CXXFLAGS"
+    CXXFLAGS="$CXXFLAGS -fstack-protector"
+    AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[],[ssp_cxx=no])
+    echo $ssp_cxx
+    if test "X$ssp_cxx" = "Xno"; then
+        CXXFLAGS="$ssp_old_cxxflags"
+    else
+      AC_DEFINE([ENABLE_SSP_CXX], 1, [Define if SSP C++ support is enabled.])
+    fi
+  fi
+])

m4/gcc-wextra.m4

@@ -0,0 +1,18 @@
+dnl Check for support of the GCC -Wextra option, which enables extra warnings.
+dnl Support for this option was added in gcc 3.4.0.
+dnl
+AC_DEFUN([GCC_WEXTRA],[
+  gcc_wextra=yes
+  if test "X$CC" != "X"; then
+    AC_MSG_CHECKING([whether ${CC} accepts -Wextra])
+    gcc_old_cflags="$CFLAGS"
+    CFLAGS="$CFLAGS -Wextra"
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[
+       AC_MSG_RESULT(yes)
+    ],[
+       AC_MSG_RESULT(no)
+       gcc_wextra=no
+       CFLAGS="$ssp_old_cflags"
+    ])
+  fi
+])

m4/libcap-capabilities.m4

@@ -0,0 +1,34 @@
+dnl Check for POSIX.1e capabilities support with libcap
+AC_DEFUN([CHECK_LIBCAP],
+[
+  AC_ARG_WITH(libcap,
+    AS_HELP_STRING([--with-libcap@<:@=auto/yes/no@:>@],[Build with libcap POSIX.1e capabilities support @<:@default=auto@:>@]),,
+    with_libcap=auto)
+
+  if test "X$with_libcap" = "Xno" ; then
+      have_libcap=no;
+  else
+      # Check for header file
+      AC_CHECK_HEADER(sys/capability.h, cap_headers=yes, cap_headers=no)
+      # Check for library
+      AC_CHECK_LIB(cap, cap_set_proc, cap_library=yes, cap_library=no)
+      # Check results are usable
+      if test "X$with_libcap" = "Xyes" -a "X$cap_library" = "Xno" ; then
+         AC_MSG_ERROR([libcap support was requested but the library was not found])
+      fi
+      if test "X$cap_library" = "Xyes" -a "X$cap_headers" = "Xno" ; then
+         AC_MSG_ERROR([libcap libraries found but headers are missing])
+      fi
+  fi
+  AC_MSG_CHECKING([whether to use libcap])
+  if test "X$cap_library" = "Xyes" -a "X$cap_library" = "Xyes"; then
+      AC_DEFINE(HAVE_LIBCAP,1,[Define to 1 if you have the libcap library])
+      AC_DEFINE(HAVE_SYS_CAPABILITY_H,1,[Define to 1 if you have the <sys/capability.h> header file])
+      LIBS="-lcap $LIBS"
+      AC_MSG_RESULT([yes])
+      AC_MSG_NOTICE([Including libcap POSIX.1e capability support])
+  else
+      AC_MSG_RESULT([no])
+      AC_MSG_NOTICE([POSIX.1e capabilities disabled or not supported])
+  fi
+])