nfqws: cygwin pre-compat

nfq/Makefile

@@ -2,14 +2,15 @@ CC ?= gcc
 CFLAGS += -std=gnu99 -Wno-logical-op-parentheses -O3
 CFLAGS_BSD = -Wno-address-of-packed-member -Wno-switch
 CFLAGS_MAC = -mmacosx-version-min=10.8
-LIBS = -lnetfilter_queue -lnfnetlink -lz
+LIBS_LINUX = -lnetfilter_queue -lnfnetlink -lz
 LIBS_BSD = -lz
+LIBS_CYGWIN = -lz
 SRC_FILES = *.c crypto/*.c
 
 all: nfqws
 
 nfqws: $(SRC_FILES)
-	$(CC) -s $(CFLAGS) -o $@ $(SRC_FILES) $(LDFLAGS) $(LIBS)
+	$(CC) -s $(CFLAGS) -o $@ $(SRC_FILES) $(LDFLAGS) $(LIBS_LINUX)
 
 bsd: $(SRC_FILES)
 	$(CC) -s $(CFLAGS) $(CFLAGS_BSD) -o dvtws $(SRC_FILES) $(LDFLAGS) $(LIBS_BSD)
@@ -21,5 +22,8 @@ mac: $(SRC_FILES)
 	lipo -create -output dvtws dvtwsx dvtwsa
 	rm -f dvtwsx dvtwsa
 
+cygwin:
+	$(CC) -s $(CFLAGS) -o winws $(SRC_FILES) $(LDFLAGS) $(LIBS_CYGWIN)
+
 clean:
 	rm -f nfqws dvtws *.o

nfq/darkmagic.c

@@ -652,8 +652,10 @@ const char *proto_name(uint8_t proto)
 			return "6in4";
 		case IPPROTO_IPIP:
 			return "4in4";
+#ifdef IPPROTO_GRE
 		case IPPROTO_GRE:
 			return "gre";
+#endif
 #ifdef IPPROTO_SCTP
 		case IPPROTO_SCTP:
 			return "sctp";