configure

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-only

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

case "$1" in
  --from-dkms-conf*)
    KDKMS=`echo "$1" | sed 's/[^=]*.//'`
    # restore options from existing Makefile, if present
    if [ -e Makefile ]; then
      set -- `sed -n 's/^CARGS = \(.*\)/\1/p' Makefile`
      FROMDKMSCONF=1
    fi
    ;;
esac

error() {
  printf "! Error: $*\n"
  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 libxtables.so, from binary)"
    return 0
  fi
  return 1
}

iptables_inc() {
  echo -n "Iptables include flags: "
  if [ "$IPTINC" ]; then
    echo "$IPTINC (user specified)"
  elif [ "$PKGVER" ]; then
    IPTINC="$PKGINC"
    echo "$IPTINC (pkg-config)"
  elif [ "$NOIPTSRC" ]; then
    IPTINC=
    echo "none (default)"
  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 "$PKGWARN" && return 1
  if ! which pkg-config >/dev/null 2>&1; then
    echo "! You don't have pkg-config, it may be useful to install it."
    PKGWARN=1
    return 1
  fi
  return 0
}
iptables_find_version() {
  echo -n "Iptables binary version: "
  if [ "$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
}

compiler_presence_test() {
  echo -n "Check for working gcc: "
  $CC -v >/dev/null 2>&1
  if [ $? = 0 ]; then
    echo Yes "($CC)"
  else
    echo No

    echo "! You need gcc to install module from source"
    if [ -s /etc/debian_version ]; then
      NAME=Debian
      if [ -e /etc/os-release ]; then
	. /etc/os-release >/dev/null 2>&1
      fi
      echo "! "
      echo "! Under $NAME try to run this:"
      echo "!   root# apt-get install gcc"
      echo "! "
    elif [ -s /etc/redhat-release ]; then
      echo "! "
      echo "! Under Centos try to run this:"
      echo "!   root# yum install gcc"
      echo "! "
    fi
    exit 1
  fi
}

compile_libitp_test() {
  local FLAGS
  local MSG
  echo -n "Checking for presence of $@... "
  if [ "$IPTINC" ]; then
    FLAGS=$IPTINC
    MSG="(using ipt-inc)"
  elif [ "$PKGINC" ]; then
    FLAGS=$PKGINC
    MSG="(using pkg-config)"
  else
    FLAGS=
    MSG=
  fi
  echo "
#define __EXPORTED_HEADERS__
#include <$*>" > test.c
  $CC -c test.c $FLAGS >/dev/null 2>&1
  RET=$?
  if [ $RET = 0 ]; then
    echo Yes $MSG;
  else
    echo No;
  fi
  rm -f test.c test.o
  return $RET
}

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 2>/dev/null
    if [ $? = 0 ]; then
      echo "Yes"
      PKGVER=$TRYPKGVER
    else
      if [ "$TRYPKGVER" ]; then
	echo "No (reported: $TRYPKGVER)"
      else
	echo "No"
      fi
      PKGVER=
    fi
  fi
  if [ "$PKGVER" ]; then
    check_pkg_config
    PKGVER=`pkg-config --modversion xtables 2>/dev/null`
    PKGINC=`pkg-config --cflags xtables`
    PKGLIB=`pkg-config --variable=xtlibdir xtables`
  elif expr "$IPTVER" : '^1\.3' >/dev/null; then
    echo "! This version of iptables ($IPTVER) will be treated as old version."
    # 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
  compiler_presence_test
  if compile_libitp_test xtables.h; then
    IPTCFLAGS="-DXTABLES $IPTCFLAGS"
  elif ! compile_libitp_test iptables.h; then
    echo "! Iptables headers not found. You may need to specify --ipt-inc=..."
    if [ -s /etc/debian_version ]; then
      echo "! "
      echo "! Under Debian simply run this:"
      if apt-cache policy libxtables-dev 2>&1 | fgrep -q "Candidate:"; then
        echo "!   root# apt-get install libxtables-dev pkg-config"
      else
        echo "!   root# apt-get install iptables-dev pkg-config"
      fi
    elif [ -s /etc/redhat-release ]; then
      echo "! "
      arch=.`uname -m`
      echo "! Under Centos simply run this:"
      echo "!   root# yum install iptables-devel$arch pkgconfig"
    fi
    exit 1
  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 2>/dev/null | head -1` && return 0
    echo "! Can not find iptables source directory, you may try setting it with --ipt-src="
    echo "! This is not fatal error, yet. Will be just using default include dir."
    NOIPTSRC=1
  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)"
  echo "  --enable-natevents     enables natevents support"
  echo "  --enable-snmp-rules    enables SNMP-index conversion rules"
  echo "  --enable-macaddress    enables MAC address for v9/IPFIX"
  echo "  --enable-vlan          enables VLAN Ids for v9/IPFIX"
  echo "  --enable-direction     enables flowDirection(61) Element"
  echo "  --enable-sampler       enables Flow Sampling"
  echo "  --enable-sampler=hash  enables Hash sampler"
  echo "  --enable-rand-tpl-id   enables seeding the template IDs from a random number"
  echo "  --enable-aggregation   enables aggregation rules"
  echo "  --enable-promisc       enables promisc hack mode"
  echo "  --promisc-mpls         decapsulate MPLS in promisc mode"
  echo "  --promisc-mpls=N       -- and record N labels (default 3)"
  echo "  --enable-physdev       enables physdev reporting"
  echo "  --enable-physdev-override      to override interfaces"
  echo "  --disable-snmp-agent   disables net-snmp agent"
  echo "  --disable-dkms         disables DKMS support completely"
  echo "  --disable-dkms-install  no DKMS install but still create dkms.conf"
  exit 0
}

CARGS="$@"
for ac_option
do
  case "$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="$ac_optarg" ;;
    --ipt-inc=*) IPTINC="-I$ac_optarg" ;;
    --kver=*)  KVERSION="$ac_optarg" ;;
    --kdir=*)      KDIR="$ac_optarg" ;;
    --enable-nat*)   KOPTS="$KOPTS -DENABLE_NAT" ;;
    --enable-mac*)   KOPTS="$KOPTS -DENABLE_MAC" ;;
    --enable-vlan*)  KOPTS="$KOPTS -DENABLE_VLAN" ;;
    --enable-direc*) KOPTS="$KOPTS -DENABLE_DIRECTION" ;;
    --enable-sampl*hash) KOPTS="$KOPTS -DENABLE_SAMPLER -DSAMPLING_HASH" ;;
    --enable-sampl*) KOPTS="$KOPTS -DENABLE_SAMPLER" ;;
    --enable-aggr*)  KOPTS="$KOPTS -DENABLE_AGGR" ;;
    --enable-rand-tpl*)  KOPTS="$KOPTS -DENABLE_RANDOM_TEMPLATE_IDS" ;;
    --enable-promi*)   ENABLE_PROMISC=1 ;;
    --promisc-mpls*)   ENABLE_PROMISC=1; PROMISC_MPLS=1; MPLS_DEPTH=${ac_optarg:-3} ;;
    --enable-snmp-r*)  KOPTS="$KOPTS -DSNMP_RULES" ;;
    --enable-physdev)       KOPTS="$KOPTS -DENABLE_PHYSDEV" ;;
    --enable-physdev-over*) KOPTS="$KOPTS -DENABLE_PHYSDEV_OVER" ;;
    --disable-snmp-a*)   SKIPSNMP=1 ;;
    --disable-net-snmp*) SKIPSNMP=1 ;;
    --disable-dkms*)     SKIPDKMS=1 ;;
    --from-dkms-conf*) ;;
    --make) echo called from make; CARGS=`echo $CARGS | sed s/--make//g` ;;
    -Werror) KOPTS="$KOPTS -Werror" ;;
    --help|-h) show_help ;;
    -*) echo Invalid option: $ac_option; exit 1 ;;
#    *) ni="$ni $ac_option" ;;
  esac
done

if [ "$ENABLE_PROMISC" = 1 ]; then KOPTS="$KOPTS -DENABLE_PROMISC"; fi
if [ "$PROMISC_MPLS" = 1 ]; then
  KOPTS="$KOPTS -DPROMISC_MPLS"
  case "$MPLS_DEPTH" in (*[!0-9]*|"") MPLS_DEPTH=1 ;; esac
  if [ "$MPLS_DEPTH" -lt 1 ]; then
    echo "! Requested MPLS stack depth is too small, limiting to 1."
  elif [ "$MPLS_DEPTH" -gt 10 ]; then
    echo "! Requested MPLS stack depth is too big, limiting to 10."
    MPLS_DEPTH=10;
  fi
  if [ "$MPLS_DEPTH" -ge 1 ]; then KOPTS="$KOPTS -DMPLS_DEPTH=$MPLS_DEPTH"; fi
fi

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_check_src2() {
  if kernel_check_src $1/source; then
    KSRC=$KDIR
  fi
  kernel_check_src $1/build
}

kernel_find_source() {
  if [ "$KDKMS" ]; then
    # dkms args is highest priority
    KDIR=$KDKMS
    KSHOW=dkms
    return 0
  fi
  KSHOW=requested
  test "$KDIR" && return 0
  KSHOW=found
  kernel_check_src2 /lib/modules/$KLIBMOD  && return 0
  kernel_check_src2 /lib/modules/$KVERSION && return 0
  kernel_check_src  /usr/src/kernels/$KVERSION && return 0
  kernel_check_src  /usr/src/linux-$KVERSION && return 0
  echo "! Linux source not found. Don't panic. You may specify kernel source"
  echo "! directory with --kdir=..., or try to install kernel-devel package,"
  echo "! or just raw sources for linux-$KVERSION from kernel.org."
  if grep -q -i centos /proc/version 2>/dev/null; then
    echo "! "
    arch=.`uname -m`
    echo "! Under Centos simply run this:"
    echo "!   root# yum install kernel-devel iptables-devel$arch pkgconfig"
  fi
  if grep -q -i debian /proc/version 2>/dev/null; then
    echo "! "
    echo "! Under Debian simply run this:"
    echo "!   root# apt-get install module-assistant iptables-dev pkg-config"
    echo "!   root# m-a prepare"
  fi
  exit 1
}

kernel_check_consistency() {
  if [ -s $KDIR/include/config/kernel.release ]; then
    SRCVER=`cat $KDIR/include/config/kernel.release`
    if [ "$KVERSION" != "$SRCVER" ]; then
      echo "! Warning: $KHOW kernel version ($KVERSION) and $KSHOW version of kernel source ($SRCVER) doesn't match!"
      echo "!   You may try to specify only kernel source tree with --kdir=$KDIR"
      echo "!   and configure will pick up version properly."
      echo "! Assuming you want to build for $SRCVER"
      KVERSION=$SRCVER
    fi
  fi
  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"
}

kconfig() {
  KCONFIG=$KDIR/.config
  if ! grep -q "^$1=" $KCONFIG 2>/dev/null; then
    if [ "$KCONFIGREPORTED" != true ]; then
      KCONFIGREPORTED=true
      echo Kernel config file checked: $KCONFIG
      echo
    fi
    echo "! Attention: $1 is undefined in your kernel configuration"
    echo "!   Without this option enabled $2 will not work."
    echo
    return 1
  fi
  return 0
}

# Respond to change in https://github.com/torvalds/linux/commit/4806e975729f99
nf_nat_needed() {
  local INC=include/linux/netfilter.h

  echo -n "Checking for presence of $INC... "
  if [ "$KSRC" -a -e $KSRC/$INC ]; then
    echo Yes
    INC=$KSRC/$INC
  elif [ -e $KDIR/$INC ]; then
    echo Yes
    INC=$KDIR/$INC
  else
    echo No
    return 1
  fi
  echo -n "netfilter.h uses CONFIG_NF_NAT_NEEDED... "
  if grep -q CONFIG_NF_NAT_NEEDED $INC; then
    echo Yes
  else
    echo No
    return 1
  fi
}

kernel_check_config() {
  kconfig CONFIG_SYSCTL			"sysctl interface"
  kconfig CONFIG_PROC_FS		"proc interface"
  if nf_nat_needed; then
    kconfig CONFIG_NF_NAT_NEEDED	"natevents"
  else
    kconfig CONFIG_NF_NAT		"natevents" && KOPTS="$KOPTS -DCONFIG_NF_NAT_NEEDED"
  fi
  kconfig CONFIG_NF_CONNTRACK_EVENTS	"natevents"
  kconfig CONFIG_IPV6			"IPv6"
  kconfig CONFIG_IP6_NF_IPTABLES	"ip6tables target"
  kconfig CONFIG_BRIDGE_NETFILTER	"physdev override"
}

kernel_check_include() {
  echo -n "Checking for presence of $1... "
  if [ "$KSRC" -a -e $KSRC/$1 ]; then
    echo Yes
    KOPTS="$KOPTS $2"
  elif [ -e $KDIR/$1 ]; then
    echo Yes
    KOPTS="$KOPTS $2"
  else
    echo No
  fi
}

kernel_check_features() {
  kernel_check_include include/linux/llist.h -DHAVE_LLIST
  kernel_check_include include/linux/grsecurity.h -DHAVE_GRSECURITY_H
}

snmp_check() {
  SNMPTARGET=
  SNMPINSTALL=
  test "$SKIPSNMP" && return

  echo -n "Searching for net-snmp-config... "
  if which net-snmp-config >/dev/null 2>&1; then
    echo Yes `which net-snmp-config`
  else
    echo No.
    SNMPCONFIG=no
  fi

  echo -n "Searching for net-snmp agent... "
  if [ -s /etc/redhat-release ]; then
    if ! rpm --quiet -q net-snmp; then
      echo No.
      SNMPADD="do:  yum install net-snmp"
      if [ "$SNMPCONFIG" ]; then
	SNMPADD="$SNMPADD net-snmp-devel"
      fi
    else
      echo Yes.
    fi
    if [ "$SNMPCONFIG" ]; then
      SNMPCONFIG="run:  yum install net-snmp-devel"
    fi
  elif [ -s /etc/debian_version ]; then
    if ! dpkg -s snmpd >/dev/null 2>&1; then
      echo No.
      SNMPADD="do:  apt-get install snmpd"
      if [ "$SNMPCONFIG" ]; then
	SNMPADD="$SNMPADD libsnmp-dev"
      fi
    else
      echo Yes.
    fi
    if [ "$SNMPCONFIG" ]; then
      SNMPCONFIG="run:  apt-get install libsnmp-dev"
    fi
  elif [ -s /etc/snmp/snmpd.conf ]; then
    echo Yes.
  else
    echo No.
    SNMPADD="install net-snmp (www.net-snmp.org)"
    SNMPCONFIG="reinstall net-snmp with agent support."
  fi

  if [ "$SNMPADD" ]; then
    echo " Assuming you don't want net-snmp agent support".
    echo " Otherwise $SNMPADD"
    return
  elif [ "$SNMPCONFIG" ]; then
    echo "! You have net-snmp agent but not development package."
    echo "! net-snmp agent will not be built, to fix:"
    echo "!   $SNMPCONFIG"
    return
  fi

  SNMPTARGET=snmp_NETFLOW.so
  SNMPINSTALL=sinstall
}

dkms_check() {
  DKMSINSTALL=
  test "$SKIPDKMS" && return

  echo -n "Checking for DKMS... "
  if ! which dkms >/dev/null 2>&1; then
    echo "No. (It may be useful to install it.)"
    echo "! "
    echo "! DKMS is method of installing kernel modules, that will"
    echo "! automatically recompile module after kernel upgrade."
    if [ -s /etc/debian_version ]; then
      echo "! "
      echo "! To install it under Debian simply run this:"
      echo "!   root# apt-get install dkms"
      echo "! "
    elif [ -s /etc/redhat-release ]; then
      echo "! "
      echo "! To install it under Centos enable EPEL or RPMforge repository,"
      echo "! then run this:"
      echo "!   root# yum install dkms"
      echo "! "
    fi
    return
  fi
  echo Yes.
  DKMSINSTALL=dinstall
  test "$FROMDKMSCONF" && return
  if dkms status | grep ^ipt-netflow, >/dev/null; then
    echo "! You are already have module installed via DKMS"
    echo "!   it will be uninstalled on 'make install' and"
    echo "!   current version of module installed afterwards."
    echo "! Use --disable-dkms option if don't want this."
  fi
}

echo "Module version: $(./version.sh)"

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
kernel_check_config
kernel_check_features

CC=${CC:-gcc}
test "$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

snmp_check
dkms_check

rm -f compat_def.h

REPLACE="\
s!@CARGS@!$CARGS!;\
s!@KVERSION@!$KVERSION!;\
s!@KDIR@!$KDIR!;\
s!@KOPTS@!$KOPTS!;\
s!@SNMPTARGET@!$SNMPTARGET!;\
s!@SNMPINSTALL@!$SNMPINSTALL!;\
s!@DKMSINSTALL@!$DKMSINSTALL!;\
s!@IPTABLES_VERSION@!$IPTVER!;\
s!@IPTABLES_CFLAGS@!$IPTCFLAGS $IPTINC!;\
s!@IPTABLES_MODULES@!$IPTLIB!"

echo -n "Creating Makefile.. "
 sed "$REPLACE" Makefile.in > Makefile
 echo done.
echo
echo "  If you need some options enabled run ./configure --help"
echo "  Now run: make all install"
echo