configure: netsniff-ng: libpcap is not a hard dependency

netsniff-ng uses libpcap only for high-level filter compiling.
Thus, let netsniff-ng not "hard-depend" on libpcap, but rather
disable filter compiling in case the user does not want to
install libpcap.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

3 files changed, 17 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index 5fe3447..f1a75a9 100644
--- a/Makefile
+++ b/Makefile
@@ -81,6 +81,12 @@ CFLAGS_DEF += -D_LARGEFILE_SOURCE
 CFLAGS_DEF += -D_LARGEFILE64_SOURCE
 CFLAGS_DEF += -D_FILE_OFFSET_BITS=64
 
+ifeq ($(CONFIG_LIBPCAP), 1)
+  CFLAGS_PCAP = -D__WITH_TCPDUMP_LIKE_FILTER
+else
+  CFLAGS_PCAP =
+endif
+
 WFLAGS_DEF  = -Wall
 WFLAGS_DEF += -Wformat=2
 WFLAGS_DEF += -Wmissing-prototypes
@@ -245,7 +251,7 @@ $(foreach tool,$(TOOLS),$(eval $(call TOOL_templ,$(tool))))
 
 %:: ;
 
-netsniff-ng: ALL_CFLAGS += $(shell pkg-config --cflags libnl-3.0) $(shell pkg-config --cflags libnl-genl-3.0) -D__WITH_PROTOS -D__WITH_TCPDUMP_LIKE_FILTER
+netsniff-ng: ALL_CFLAGS += $(shell pkg-config --cflags libnl-3.0) $(shell pkg-config --cflags libnl-genl-3.0) $(CFLAGS_PCAP) -D__WITH_PROTOS
 trafgen: ALL_CFLAGS += -I.. $(shell pkg-config --cflags libnl-3.0) $(shell pkg-config --cflags libnl-genl-3.0) -D__WITH_PROTOS
 ifpps: ALL_CFLAGS += $(shell pkg-config --cflags ncurses)
 flowtop: ALL_CFLAGS += $(shell pkg-config --cflags ncurses)
diff --git a/configure b/configure
index f31cfa0..04c9c4e 100755
--- a/configure
+++ b/configure
@@ -359,11 +359,12 @@ EOF
 	$CC -o $TMPDIR/pcaptest $TMPDIR/pcaptest.c -lpcap >> $TMPDIR/config.log 2>&1
 	if [ ! -x $TMPDIR/pcaptest ] ; then
 		echo "[NO]"
+		echo "CONFIG_LIBPCAP=0" >> Config
 		MISSING_DEFS=1
-		tools_remove "netsniff-ng"
 		tools_remove "mausezahn"
 	else
 		echo "[YES]"
+		echo "CONFIG_LIBPCAP=1" >> Config
 	fi
 }
 
diff --git a/netsniff-ng/Makefile b/netsniff-ng/Makefile
index 356ae2e..e05ad1d 100644
--- a/netsniff-ng/Makefile
+++ b/netsniff-ng/Makefile
@@ -1,10 +1,13 @@
 netsniff-ng-libs =	-lGeoIP \
 			$(shell pkg-config --libs libnl-3.0) \
 			$(shell pkg-config --libs libnl-genl-3.0) \
-			-lpcap \
 			-lpthread \
 			-lz
 
+ifeq ($(CONFIG_LIBPCAP), 1)
+netsniff-ng-libs +=	-lpcap
+endif
+
 netsniff-ng-objs =	dissector.o \
 			dissector_eth.o \
 			dissector_80211.o \
@@ -46,7 +49,6 @@ netsniff-ng-objs =	dissector.o \
 			xmalloc.o \
 			hash.o \
 			bpf.o \
-			bpf_comp.o \
 			oui.o \
 			pcap_rw.o \
 			pcap_sg.o \
@@ -60,3 +62,7 @@ netsniff-ng-objs =	dissector.o \
 			geoip.o \
 			mac80211.o \
 			netsniff-ng.o
+
+ifeq ($(CONFIG_LIBPCAP), 1)
+netsniff-ng-objs +=	bpf_comp.o
+endif