[PATCH] configure: Add option to enable/disable libnfnetlink

This changes the configure behaviour from autodetecting
for libnfnetlink to having an option to disable it explicitly

Upstream-Status: Pending

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Maxin B. John <maxin.john@intel.com>
---
diff -Naur iptables-1.6.0-old/configure.ac iptables-1.6.0/configure.ac
--- iptables-1.6.0-old/configure.ac	2015-12-28 18:40:35.255417976 +0200
+++ iptables-1.6.0/configure.ac	2015-12-29 13:01:12.388840200 +0200
@@ -63,6 +63,9 @@
 AC_ARG_ENABLE([nftables],
 	AS_HELP_STRING([--disable-nftables], [Do not build nftables compat]),
 	[enable_nftables="$enableval"], [enable_nftables="yes"])
+AC_ARG_ENABLE([libnfnetlink],
+    AS_HELP_STRING([--disable-libnfnetlink], [Do not use netfilter netlink library]),
+    [enable_libnfnetlink="$enableval"], [enable_libnfnetlink="yes"])
 
 libiptc_LDFLAGS2="";
 AX_CHECK_LINKER_FLAGS([-Wl,--no-as-needed],
@@ -123,9 +126,10 @@
 	AC_CHECK_LIB(pcap, pcap_compile,, AC_MSG_ERROR(missing libpcap library required by bpf compiler or nfsynproxy tool))
 fi
 
-PKG_CHECK_MODULES([libnfnetlink], [libnfnetlink >= 1.0],
-	[nfnetlink=1], [nfnetlink=0])
-AM_CONDITIONAL([HAVE_LIBNFNETLINK], [test "$nfnetlink" = 1])
+AS_IF([test "x$enable_libnfnetlink" = "xyes"], [
+    PKG_CHECK_MODULES([libnfnetlink], [libnfnetlink >= 1.0])
+    ])
+AM_CONDITIONAL([HAVE_LIBNFNETLINK], [test "x$enable_libnfnetlink" = "xyes"])
 
 if test "x$enable_nftables" = "xyes"; then
 	PKG_CHECK_MODULES([libmnl], [libmnl >= 1.0], [mnl=1], [mnl=0])