Enable compiler hardening flags by default.

Check whether the compiler supports hardening flags and enable them unless
--disable-hardening is specified.

Conflicts:
	configure.ac

diff --git a/configure.ac b/configure.ac
index 75456a0..28d94a6 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -109,7 +109,7 @@ AC_ARG_ENABLE(tunemu,
 )
 
 AC_ARG_WITH(windows2000,
 )
 
 AC_ARG_WITH(windows2000,

-  AS_HELP_STRING([--without-windows2000], [compile with support for Windows 2000. This disables support for tunneling over existing IPv6 networks.]),
+  AS_HELP_STRING([--with-windows2000], [compile with support for Windows 2000. This disables support for tunneling over existing IPv6 networks.]),

   [ AS_IF([test "x$with_windows2000" = "xyes"],
       [AC_DEFINE(WITH_WINDOWS2000, 1, [Compile with support for Windows 2000])])
   ]
   [ AS_IF([test "x$with_windows2000" = "xyes"],
       [AC_DEFINE(WITH_WINDOWS2000, 1, [Compile with support for Windows 2000])])
   ]


@@ -133,6 +133,30 @@ if test -d /sw/lib ; then
   LIBS="$LIBS -L/sw/lib"
 fi
 
   LIBS="$LIBS -L/sw/lib"
 fi
 

+dnl Compiler hardening flags
+
+AC_ARG_ENABLE([hardening], AS_HELP_STRING([--disable-hardening], [disable compiler and linker hardening flags]))
+AS_IF([test "x$enable_hardening" != "xno"],
+  [AX_CHECK_COMPILE_FLAG([-DFORTIFY_SOURCE=2], [CPPFLAGS="$CPPFLAGS -DFORITFY_SOURCE=2"])
+   AX_CHECK_COMPILE_FLAG([-fno-strict-overflow], [CPPFLAGS="$CPPFLAGS -fno-strict-overflow"])
+   AX_CHECK_COMPILE_FLAG([-fwrapv], [CPPFLAGS="$CPPFLAGS -fwrapv"])
+   case $host_os in
+     *mingw*)
+       AX_CHECK_LINK_FLAG([-Wl,--dynamicbase], [LDFLAGS="$LDFLAGS -Wl,--dynamicbase"])
+       AX_CHECK_LINK_FLAG([-Wl,--nxcompat], [LDFLAGS="$LDFLAGS -Wl,--nxcompat"])
+       # TODO: get -fstack-protector-all working with MinGW
+       ;;
+     *)
+       AX_CHECK_COMPILE_FLAG([-fstack-protector-all], [CPPFLAGS="$CPPFLAGS -fstack-protector-all"])
+       AX_CHECK_COMPILE_FLAG([-fPIE], [CPPFLAGS="$CPPFLAGS -fPIE"])
+       AX_CHECK_LINK_FLAG([-pie], [LDFLAGS="$LDFLAGS -pie"])
+       ;;
+   esac
+   AX_CHECK_LINK_FLAG([-Wl,-z,relro], [LDFLAGS="$LDFLAGS -Wl,-z,relro"])
+   AX_CHECK_LINK_FLAG([-Wl,-z,now], [LDFLAGS="$LDFLAGS -Wl,-z,now"])
+  ]
+);
+

 dnl Checks for header files.
 dnl We do this in multiple stages, because unlike Linux all the other operating systems really suck and don't include their own dependencies.
 
 dnl Checks for header files.
 dnl We do this in multiple stages, because unlike Linux all the other operating systems really suck and don't include their own dependencies.
 


@@ -206,7 +230,7 @@ AM_CONDITIONAL(GCRYPT, test "$gcrypt" = true)
 
 dnl Check if support for jumbograms is requested 
 AC_ARG_ENABLE(jumbograms,
 
 dnl Check if support for jumbograms is requested 
 AC_ARG_ENABLE(jumbograms,

-  AS_HELP_STRING([--disable-jumbograms], [enable support for jumbograms (packets up to 9000 bytes)]),
+  AS_HELP_STRING([--enable-jumbograms], [enable support for jumbograms (packets up to 9000 bytes)]),

   [ AS_IF([test "x$enable_jumbograms" = "xyes"],
       [ AC_DEFINE(ENABLE_JUMBOGRAMS, 1, [Support for jumbograms (packets up to 9000 bytes)]) ])
   ]
   [ AS_IF([test "x$enable_jumbograms" = "xyes"],
       [ AC_DEFINE(ENABLE_JUMBOGRAMS, 1, [Support for jumbograms (packets up to 9000 bytes)]) ])
   ]

diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
new file mode 100644 (file)
index 0000000..c3a8d69
--- /dev/null
+++ b/m4/ax_check_compile_flag.m4
@@ -0,0 +1,72 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the current language's compiler
+#   or gives an error.  (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the current language's default
+#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
+#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
+#   force the compiler to issue an error when a bad flag is given.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   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/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 2
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS

diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
new file mode 100644 (file)
index 0000000..e2d0d36
--- /dev/null
+++ b/m4/ax_check_link_flag.m4
@@ -0,0 +1,71 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the linker or gives an error.
+#   (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   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/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 2
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $4 $1"
+  AC_LINK_IFELSE([AC_LANG_PROGRAM()],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  LDFLAGS=$ax_check_save_flags])
+AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS