configure

#!/bin/bash

PATH=$PATH:/bin:/usr/bin:/usr/sbin:/sbin:/usr/local/sbin

error() {
  echo -e "! Error: $@"
  exit 1
}

iptables_src_version() {
  test "$IPTSRC" || return 1

  echo -n "Checking iptables sources version: "
  SRC="$IPTSRC/Makefile"
  test -s "$SRC" || error "Please build iptables first."
  VER=`sed -n 's/^\(IPTABLES_\)\?VERSION[ :]= \?//p' "$SRC"`
  test "$VER" || error "Unknown version of iptables."
  if [ "$VER" = "$IPTVER" ]; then
    echo "$VER (ok)"
  else
    echo "$VER"
    error "Source version ($VER) doesn't match binary ($IPTVER)"
  fi
}

get_lib_dir() {
  test -s "$1" && LIB=`sed -n 's/.*_LIB_DIR "\(.*\)"/\1/p' "$1"`
  if [ "$LIB" ]; then
    IPTLIB=$LIB
    echo "$IPTLIB (from sources)"
    return 0
  fi
  return 1
}

get_lib_from_bin() {
  LIB=`strings $IPTBIN | grep ^/.*lib.*tables`
  if [ "$LIB" ]; then
    IPTLIB=$LIB
    echo "$IPTLIB (from binary)"
    return 0
  fi
  return 1
}

get_lib_from_lib() {
  XLIB=`/usr/bin/ldd $IPTBIN | grep libxtables | sed -n 's!.* \(/[^ ]\+\).*!\1!p'`
  test "$XLIB" || return 1
  LIB=`strings $XLIB | grep ^/.*lib.*tables`
  if [ "$LIB" ]; then
    IPTLIB=$LIB
    echo "$IPTLIB (from library)"
    return 0
  fi
  return 1
}

iptables_inc() {
  echo -n "Iptables include flags: "
  if [ "$IPTINC" ]; then
    IPTINC="-I$IPTINC"
    echo "$IPTINC (user specified)"
  elif [ "$PKGVER" ]; then
    IPTINC="$PKGINC"
    echo "$IPTINC (pkg-config)"
  else
    IPTINC="$IPTSRC/include"
    IPTINC="-I$IPTINC"
    echo "$IPTINC (from source)"
  fi
}

iptables_modules() {
  echo -n "Iptables module path: "
  if [ "$IPTLIB" ]; then
    echo "$IPTLIB (user specified)"
  else
    if [ "$PKGLIB" ]; then
      IPTLIB="$PKGLIB"
      echo "$IPTLIB (pkg-config)"
    else
      get_lib_dir "$IPTSRC/include/iptables.h" && return 0
      get_lib_dir "$IPTSRC/include/xtables.h" && return 0
      get_lib_dir "$IPTSRC/xtables/internal.h" && return 0
      get_lib_from_bin && return 0
      get_lib_from_lib && return 0
      error "can not find, try setting it with --ipt-lib="
    fi
  fi
}

try_dir() {
  if [ -d "$1/include" ]; then
    echo "Found iptables sources at $1"
    IPTSRC=$1
    return 0
  fi
  return 1
}

try_dirg() {
  try_dir "$1" && return 0
  try_dir "$1.git" && return 0
}

try_dir2() {
  test -d "$1" && try_dir `dirname $1` && return 0
}

check_pkg_config() {
  test "$PKGWARN" && return 1
  if ! which pkg-config >/dev/null 2>&1; then
    echo "! You don't have pkg-config, it may be useful to install it."
    PKGWARN=1
  fi
}
iptables_find_version() {
  echo -n "Iptables binary version: "
  if [ "$IPTVER" ]; then
    echo "$IPTVER (user specified)"
  else
    IPTVER=`$IPTBIN -V 2>/dev/null | sed -n s/iptables.v//p`
    if [ "$IPTVER" ]; then
      echo "$IPTVER (detected from $IPTBIN)"
      return
    else
      echo "no iptables binary found"
    fi
    check_pkg_config
    PKGVER=`pkg-config --modversion xtables 2>/dev/null`
    if [ "$PKGVER" ]; then
      IPTVER="$PKGVER"
      echo "Xtables version: $IPTVER (detected from `which pkg-config`)"
      return
    fi
    error "Can not find iptables version, try setting it with --ipt-ver="
  fi
}

iptables_try_pkgconfig() {
  if [ ! "$PKGVER" ]; then
    check_pkg_config
    PKGVER=`pkg-config --modversion xtables 2>/dev/null`
    TRYPKGVER=`pkg-config --modversion xtables 2>/dev/null`
    echo -n "pkg-config for version $IPTVER exists: "
    pkg-config --exact-version=$IPTVER xtables
    if [ $? = 0 ]; then
      echo "Yes"
      PKGVER=$TRYPKGVER
    else
      echo "No (reported: $TRYPKGVER)"
    fi
  fi
  if [ "$PKGVER" ]; then
    check_pkg_config
    PKGVER=`pkg-config --modversion xtables 2>/dev/null`
    PKGINC=`pkg-config --cflags xtables`
    PKGLIB=`pkg-config --variable=xtlibdir xtables`
    IPTCFLAGS="-DXTABLES"
  else
    # Newer versions of iptables should not have -I/kernel/include!
    # So I assume that newer version will have correct pkg-config set up
    # and if not, then it's older who need it.
    IPTCFLAGS="-I$KDIR/include -DIPTABLES_VERSION=\\\\\"$IPTVER\\\\\""
  fi
}

iptables_find_src() {
  test "$IPTINC" && return 1
  test "$PKGVER" && return 1

  VER="iptables-$IPTVER"
  if [ "$IPTSRC" ]; then
    echo "User specified source directory: $IPTSRC"
    try_dir $IPTSRC || error "Specified directory is not iptables source.."
  else
    echo "Searching for $VER sources.."
    try_dir "./$VER" && return 0
    try_dir "../$VER" && return 0
    try_dir "/usr/src/$VER" && return 0
    try_dirg "iptables" && return 0
    try_dirg "../iptables" && return 0
    try_dirg "/usr/src/iptables" && return 0
    try_dir2 `locate $VER/extensions | head -1` && return 0
    error "Can not find iptables source directory, try setting it with --ipt-src="
  fi
}

show_help() {
  echo "Possible options:"
  echo "  --ipt-ver=..  iptables version (ex.: 1.4.2)"
  echo "  --ipt-bin=..  iptables binary to use (ex.: /usr/sbin/iptables)"
  echo "  --ipt-src=..  directory for iptable source (ex.: ../iptables-1.4.2)"
  echo "  --ipt-lib=..  iptable modules path (ex.: /usr/libexec/xtables)"
  echo "  --ipt-inc=..  directory for iptable headers (ex.: /usr/include)"
  echo "  --kver=..     kernel version (ex.: 2.6.30-std-def-alt15)"
  echo "  --kdir=..     directory for kernel source (ex.: /usr/src/kernel)"
  exit 0
}

for ac_option
do
  case "$ac_option" in
    -*=*) ac_optarg=`echo "$ac_option" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
    *) ac_optarg= ;;
  esac

  case "$ac_option" in
    --ipt-bin=*) IPTBIN="$ac_optarg" ;;
    --ipt-lib=*) IPTLIB="$ac_optarg" ;;
    --ipt-src=*) IPTSRC="$ac_optarg" ;;
    --ipt-ver=*) IPTVER="$ac_optarg" ;;
    --ipt-inc=*) IPTINC="$ac_optarg" ;;
    --kver=*)  KVERSION="$ac_optarg" ;;
    --kdir=*)      KDIR="$ac_optarg" ;;
    --make) echo called from make ;;
    --help) show_help ;;
    -*) echo Invalid option: $ac_option; exit 1 ;;
#    *) ni="$ni $ac_option" ;;
  esac
done

kernel_find_version() {
  KHOW=requested
  test "$KVERSION" && return 0

  if grep -q Debian /proc/version; then
    KHOW=proc
    KVERSION=`sed -n 's/.*#.*Debian \([0-9\.]\+\)-.*/\1/p' /proc/version`
    KLIBMOD=`uname -r`
  else
    KHOW=uname
    KVERSION=`uname -r`
  fi
  test "$KDIR" || return 0

  test -s $KDIR/Makefile || return 1
  test -s $KDIR/include/config/kernel.release || return 1
  KVERSION=`cat $KDIR/include/config/kernel.release`
  KHOW=sources
}

kernel_check_src() {
  if [ -s "$1/Makefile" ]; then
    KDIR="$1"
    return 0
  fi
  return 1
}

kernel_find_source() {
  KSHOW=requested
  test "$KDIR" && return 0
  KSHOW=found
  kernel_check_src /lib/modules/$KLIBMOD/build && return 0
  kernel_check_src /lib/modules/$KVERSION/build && return 0
  kernel_check_src /usr/src/kernels/$KVERSION && return 0
  kernel_check_src /usr/src/linux-$KVERSION && return 0
  error "Linux source not found. Specify kernel source directory with --kdir=...\n!" \
	"or try to install kernel-devel package or sources for linux-$KVERSION"
}

kernel_check_consistency() {
  if test -s $KDIR/include/config/kernel.release; then
    SRCVER=`cat $KDIR/include/config/kernel.release`
    test "$KVERSION" != "$SRCVER" && error "$KHOW kernel version ($KVERSION) and $KSHOW version of kernel source ($SRCVER) doesn't match!\n!" \
      "You may try to specify only kernel source tree with --kdir=$KDIR\n!" \
      "and configure will pick up version propely."
  else
    test -e "$KDIR/.config" || error ".config in kernel source not found, run  make menuconfig  in $KDIR"
    test -d "$KDIR/include/config" || error "kernel is not prepared, run  make prepare modules_prepare  in $KDIR"
  fi
}

kernel_find_version	#KVERSION
test "$KLIBMOD" || KLIBMOD=$KVERSION
echo "Kernel version: $KVERSION ($KHOW)"
kernel_find_source	#KDIR
echo "Kernel sources: $KDIR ($KSHOW)"
kernel_check_consistency

test "$IPTBIN" || IPTBIN=`which iptables`

iptables_find_version	#IPTVER
iptables_try_pkgconfig	#try to configure from pkg-config
iptables_find_src	#IPTSRC
iptables_src_version	#check that IPTSRC match to IPTVER
iptables_inc		#IPTINC
iptables_modules	#IPTLIB

REPLACE="\
s!@KVERSION@!$KVERSION!;\
s!@KDIR@!$KDIR!;\
s!@IPTABLES_VERSION@!$IPTVER!;\
s!@IPTABLES_CFLAGS@!$IPTCFLAGS $IPTINC!;\
s!@IPTABLES_MODULES@!$IPTLIB!"

echo -n "Creating Makefile.. "
sed "$REPLACE" Makefile.in > Makefile
echo done.
echo
echo "  Now run: make all install"
echo