WIP: autotools support for LKM

Makefile.am

@@ -160,9 +160,13 @@ include swig/include.am
 include src/include.am
 include support/include.am
 include wolfcrypt/user-crypto/include.am
+if !BUILD_LINUXKM
 include wolfcrypt/benchmark/include.am
+endif
 include wolfcrypt/src/include.am
+if !BUILD_LINUXKM
 include wolfcrypt/test/include.am
+endif
 include examples/include.am
 include testsuite/include.am
 include tests/include.am
@@ -190,6 +194,10 @@ include IDE/include.am
 endif
 include scripts/include.am
 
+if BUILD_LINUXKM
+SUBDIRS = . linuxkm
+endif
+
 if USE_VALGRIND
 TESTS_ENVIRONMENT=./valgrind-error.sh
 endif

configure.ac

@@ -3375,9 +3375,27 @@ AC_ARG_ENABLE([linuxkm],
 if test "x$ENABLED_LINUXKM" = "xyes"
 then
     AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_LINUXKM"
+
+    AC_PATH_DEFAULT_KERNEL_SOURCE
+    AC_ARG_WITH([linux-source],
+        [AS_HELP_STRING([--with-linux-source=PATH],[PATH to root of Linux kernel build tree])],
+        [KROOT=$withval],
+        [KROOT=$DEFAULT_KROOT])
+
+    AC_DEFAULT_KERNEL_ARCH
+    AC_ARG_WITH([linux-arch],
+        [AS_HELP_STRING([--with-linux-arch=arch],[built arch (SRCARCH) of Linux kernel build tree])],
+        [KARCH=$withval],
+        [KARCH=$DEFAULT_KARCH])
+
+    AC_DEFINE_KERNEL_KFLAGS
+
+    AM_CPPFLAGS="$KFLAGS $AM_CPPFLAGS"
 fi
 
 
+
+
 #valgrind
 AC_ARG_ENABLE([valgrind],
     [AS_HELP_STRING([--enable-valgrind],[Enable valgrind for unit tests (default: disabled)])],
@@ -5382,6 +5400,7 @@ AM_CONDITIONAL([BUILD_PKI],[test "x$ENABLED_PKI" = "xyes"])
 AM_CONDITIONAL([BUILD_DES3],[test "x$ENABLED_DES3" = "xyes" || test "x$ENABLED_USERSETTINGS" = "xyes"])
 AM_CONDITIONAL([BUILD_PKCS7],[test "x$ENABLED_PKCS7" = "xyes" || test "x$ENABLED_USERSETTINGS" = "xyes"])
 AM_CONDITIONAL([BUILD_HASHFLAGS],[test "x$ENABLED_HASHFLAGS" = "xyes"])
+AM_CONDITIONAL([BUILD_LINUXKM],[test "x$ENABLED_LINUXKM" = "xyes"])
 
 
 CREATE_HEX_VERSION
@@ -5394,7 +5413,7 @@ AC_SUBST([LIB_STATIC_ADD])
 
 # FINAL
 AC_CONFIG_FILES([stamp-h], [echo timestamp > stamp-h])
-AC_CONFIG_FILES([Makefile wolfssl/version.h wolfssl/options.h cyassl/options.h support/wolfssl.pc rpm/spec])
+AC_CONFIG_FILES([Makefile wolfssl/version.h wolfssl/options.h cyassl/options.h support/wolfssl.pc rpm/spec linuxkm/Makefile])
 
 AX_CREATE_GENERIC_CONFIG
 AX_AM_JOBSERVER([yes])
@@ -5644,6 +5663,10 @@ echo "   * wolfSCEP                    $ENABLED_WOLFSCEP"
 echo "   * Secure Remote Password      $ENABLED_SRP"
 echo "   * Small Stack:                $ENABLED_SMALL_STACK"
 echo "   * Linux Kernel Module:        $ENABLED_LINUXKM"
+test "$ENABLED_LINUXKM" = "yes" && \
+echo "   * Linux Kernel Build Root:    $KROOT" && \
+echo "   * Linux Kernel Build Arch:    $KARCH" && \
+echo "   * Linux Kernel Build Flags:   $KFLAGS"
 echo "   * valgrind unit tests:        $ENABLED_VALGRIND"
 echo "   * LIBZ:                       $ENABLED_LIBZ"
 echo "   * Examples:                   $ENABLED_EXAMPLES"
@@ -5693,4 +5716,3 @@ if test "$MINGW_LIB_WARNING" = "yes"
 then
     AC_MSG_WARN([Building with shared and static library at the same time on this system may cause export/import problems when using non contemporary GNU tools.])
 fi
-

linuxkm/Makefile.am

@@ -0,0 +1,5 @@
+EXTRA_PROGRAMS = automake_dummy
+automake_dummy_SOURCES = wolfssl_linuxkm.c
+module_DATA = wolfssl_linuxkm.o 
+#include ../Makefile.common
+include Makefile.common

linuxkm/Makefile.common

@@ -0,0 +1,20 @@
+# Makefile.common
+moduledir = @moduledir@
+KERNEL_LOCATION=@kerneldir@
+KBUILD_VERBOSE = 1
+MOD_DEVDIR = $(PWD)
+
+export module_DATA
+
+$(module_DATA): $(automake_dummy_SOURCES) 
+	echo "not building kernel module yet"
+
+#	mv Makefile Makefile.automake 
+#	cp $(srcdir)/../Makefile.kernel Makefile 
+#	CPPFLAGS="" CFLAGS="" LDFLAGS="" \
+#	$(MAKE) -C $(KROOT) \
+#	ARCH="$KARCH" CC="gcc" M=$(PWD) modules\
+#		KBUILD_VERBOSE=$(KBUILD_VERBOSE) 
+#	mv Makefile.automake Makefile 
+
+CLEANFILES = $(module_DATA) .$(module_DATA).flags $(module_DATA:.o=.mod.c) $(module_DATA:.o=.@kernelext@) *~

linuxkm/wolfssl_linuxkm.c

@@ -0,0 +1,28 @@
+/* http://h-wrt.com/en/mini-how-to/autotoolsSimpleModule */
+
+/*  src/module_hello.c */
+
+#include <linux/init.h>
+#include <linux/module.h>
+
+static int __init
+hello_init(void)
+{
+   printk("Hello, world!\n");
+   return 0;
+}
+
+module_init(hello_init);
+
+static void __exit
+hello_exit(void)
+{
+   printk("Goodbye, world!\n");
+}
+
+module_exit(hello_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("noname ");
+MODULE_DESCRIPTION("\"Hello, world!\" test module");
+MODULE_VERSION("printk");

m4/ax_linuxkm.m4

@@ -0,0 +1,41 @@
+AC_DEFUN([AC_PATH_DEFAULT_KERNEL_SOURCE],
+[
+AC_MSG_CHECKING([for default kernel build root])
+if test -d /lib/modules/`uname -r`/build/.config; then
+  DEFAULT_KROOT=/lib/modules/`uname -r`/build
+  AC_MSG_RESULT([$DEFAULT_KROOT])
+elif test -r /usr/src/linux/.config; then
+  DEFAULT_KROOT=/usr/src/linux
+  AC_MSG_RESULT([$DEFAULT_KROOT])
+else
+  AC_MSG_RESULT([no default configured kernel found])
+fi
+])
+
+AC_DEFUN([AC_DEFAULT_KERNEL_ARCH],
+[
+AC_REQUIRE([AC_PROG_AWK])
+AC_MSG_CHECKING([for default kernel arch])
+if test -f ${KROOT}/.config; then
+  # "# Linux/x86 5.8.1-gentoo Kernel Configuration"
+  DEFAULT_KARCH=`$AWK '/^# Linux/\
+{split($[]2,arch_fields,"/"); print arch_fields[[2]]; exit(0);}' ${KROOT}/.config`
+fi
+if test -n "$DEFAULT_KARCH"; then
+  AC_MSG_RESULT([$DEFAULT_KARCH])
+else
+  AC_MSG_RESULT([no default configured kernel arch found])
+fi
+])
+
+AC_DEFUN([AC_DEFINE_KERNEL_KFLAGS],
+[
+    AC_MSG_CHECKING([flags for compiling objects for kernel module])
+    if test -z "${KROOT}" || test -z "${KARCH}"; then
+        AC_MSG_ERROR([Linux kernel configuration incomplete (KROOT=${KROOT}, KARCH=${KARCH}).])
+    else
+        GCC_SHORT_VERSION="$($CC -dumpversion)"
+        KFLAGS="-I${KROOT}/include -I${KROOT}/include/uapi -I${KROOT}/arch/${KARCH}/include -I${KROOT}/arch/${KARCH}/include/generated -I${KROOT}/arch/${KARCH}/include/generated/uapi -I${KROOT}/arch/${KARCH}/include/uapi -I${KROOT}/tools/include -I${KROOT}/tools/arch/${KARCH}/include -I${KROOT}/tools/include/uapi -I/usr/lib/gcc/${host_cpu}-${host_vendor}-${host_os}/${GCC_SHORT_VERSION}/include"
+        AC_MSG_RESULT([$KFLAGS])
+    fi
+])