build: Restore support for cross-compiling the netsniff-ng toolkit

Ever since we switched to the hand-crafted ./configure script, support
for cross-compiling the netsniff-ng toolkit was basically broken.

Restore the abaility to cross-compile our tools by making ./configure
consider the CROSS_COMPILE and SYSROOT variables.

Example for cross-compiling on arm:

  $ CROSS_COMPILE=arm-linux-gnueabihf- \
    SYSROOT=/usr/arm-linux-gnueabihf \
    ./configure
  $ make

assuming the cross-compiled libraries (and their respective pkg-config
information) are in /usr/arm-linux-gnueabihf.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 65 insertions, 22 deletions

diff --git a/configure b/configure
index 2e553cb..b02eb18 100755
--- a/configure
+++ b/configure
@@ -1,11 +1,11 @@
 #!/bin/bash
 # This isn't a configure generated by autoconf!
 # netsniff-ng build system
-# Copyright 2013 Tobias Klauser <tklauser@distanz.ch>
+# Copyright 2013-2015 Tobias Klauser <tklauser@distanz.ch>
 # Copyright 2013 Daniel Borkmann <borkmann@gnumaniacs.org>
 # Subject to the GNU GPL, version 2.
 
-MISSING_PKG_CONFIG=0
+MISSING_TOOLCHAIN=0
 MISSING_DEFS=0
 MISSING_NACL=0
 
@@ -18,7 +18,15 @@ HAVE_LIBGEOIP=0
 HAVE_LIBZ=0
 HAVE_TPACKET3=0
 
-[ -z $CC ] && CC=cc
+# use "CROSS_COMPILE=<prefix> SYSROOT=<path> ./configure && make" for cross compilation
+
+[ -z $CC ] && CC="${CROSS_COMPILE}gcc"
+[ -z $LD ] && LD="${CROSS_COMPILE}gcc"
+[ -z $STRIP ] && STRIP="${CROSS_COMPILE}strip"
+if [ "x$SYSROOT" != "x" ] ; then
+	PKG_CONFIG_PATH="$SYSROOT/usr/lib/pkgconfig:$PKG_CONFIG_PATH"
+fi
+[ -z $PKG_CONFIG ] && PKG_CONFIG="${CROSS_COMPILE}pkg-config"
 
 TMPDIR=$(mktemp -d config.XXXXXX)
 trap 'status=$?; rm -rf $TMPDIR; exit $status' EXIT HUP INT QUIT TERM
@@ -43,16 +51,50 @@ tools_remove()
 	TOOLS_NOBUILD=${TOOLS_NOBUILD# }
 }
 
-check_pkg_config()
+check_toolchain()
 {
-	echo -n "[*] Checking pkg-config ... "
+	if [ "x$CROSS_COMPILE" != "x" ] ; then
+		echo "[*] Cross-compiling for $($CC -print-multiarch)"
+		echo "CROSS_COMPILE=$CROSS_COMPILE" >> Config
+	fi
+
+	echo -n "[*] Checking compiler $CC ... "
+	if [ "x$(which $CC 2>> config.log)" == "x" ] ; then
+		echo "[NO]"
+		MISSING_TOOLCHAIN=1
+	else
+		echo "[YES]"
+		echo "CC=$CC" >> Config
+	fi
 
-	if [ "x$(which pkg-config 2>> config.log)" == "x" ] ; then
+	echo -n "[*] Checking linker $LD ... "
+	if [ "x$(which $LD 2>> config.log)" == "x" ] ; then
 		echo "[NO]"
-		MISSING_PKG_CONFIG=1
+		MISSING_TOOLCHAIN=1
 	else
 		echo "[YES]"
+		echo "LD=$LD" >> Config
 	fi
+
+	echo -n "[*] Checking $PKG_CONFIG ... "
+	if [ "x$(which $PKG_CONFIG 2>> config.log)" == "x" ] ; then
+		echo "[NO]"
+		MISSING_TOOLCHAIN=1
+	else
+		echo "[YES]"
+		echo "PKG_CONFIG=$PKG_CONFIG" >> Config
+		echo "PKG_CONFIG_PATH=$PKG_CONFIG_PATH" >> Config
+	fi
+
+	echo -n "[*] Checking $STRIP ... "
+	if [ "x$(which $STRIP 2>> config.log)" == "x" ] ; then
+		echo "[NO]"
+		MISSING_TOOLCHAIN=1
+	else
+		echo "[YES]"
+		echo "STRIP=$STRIP" >> Config
+	fi
+
 }
 
 check_flex()
@@ -131,12 +173,12 @@ check_libnl()
 	echo -n "[*] Checking libnl ... "
 
 	cat > $TMPDIR/libnltest.c << EOF
-#include <libnl3/netlink/genl/genl.h>
-#include <libnl3/netlink/genl/family.h>
-#include <libnl3/netlink/genl/ctrl.h>
-#include <libnl3/netlink/msg.h>
-#include <libnl3/netlink/attr.h>
-#include <libnl3/netlink/version.h>
+#include <netlink/genl/genl.h>
+#include <netlink/genl/family.h>
+#include <netlink/genl/ctrl.h>
+#include <netlink/msg.h>
+#include <netlink/attr.h>
+#include <netlink/version.h>
 
 #if LIBNL_VER_NUM < LIBNL_VER(3,0)
 # error incompatible libnl version
@@ -153,12 +195,12 @@ int main(void)
 EOF
 
 	$CC \
-		$(pkg-config --cflags libnl-3.0 2>> config.log) \
-		$(pkg-config --cflags libnl-genl-3.0 2>> config.log) \
+		$($PKG_CONFIG --cflags libnl-3.0 2>> config.log) \
+		$($PKG_CONFIG --cflags libnl-genl-3.0 2>> config.log) \
 		-o $TMPDIR/libnltest \
 		$TMPDIR/libnltest.c \
-		$(pkg-config --libs libnl-3.0 2>> config.log) \
-		$(pkg-config --libs libnl-genl-3.0 2>> config.log) \
+		$($PKG_CONFIG --libs libnl-3.0 2>> config.log) \
+		$($PKG_CONFIG --libs libnl-genl-3.0 2>> config.log) \
 			>> config.log 2>&1
 	if [ ! -x $TMPDIR/libnltest ] ; then
 		echo "[NO]"
@@ -248,9 +290,9 @@ int main(void)
 EOF
 
 	$CC \
-		$(pkg-config --cflags ncurses 2>> config.log) \
+		$($PKG_CONFIG --cflags ncurses 2>> config.log) \
 		-o $TMPDIR/ncursestest $TMPDIR/ncursestest.c \
-		$(pkg-config --libs ncurses 2>> config.log \
+		$($PKG_CONFIG --libs ncurses 2>> config.log \
 	          || echo '-lncurses' ) \
 			>> config.log 2>&1
 	if [ ! -x $TMPDIR/ncursestest ] ; then
@@ -570,10 +612,11 @@ EOF
 rm -f config.log
 
 echo "# This file is autogenerated by the configure script" > Config
-check_pkg_config
+check_toolchain
 
-if [ "$MISSING_PKG_CONFIG" == "1" ] ; then
-	echo "[!] pkg-config is not installed on your system or not in the PATH"
+if [ "$MISSING_TOOLCHAIN" == "1" ] ; then
+	echo "[!] One or more of the toolchain tools couldn't be found in your"
+	echo "    \$PATH. Please check the file config.log for details."
 	exit 1
 fi