feature: default interface and basic start

include/dns.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <netinet/in.h>
+
+int dns_lookup(char *ip_addr, char *hostname, struct sockaddr_in *addr_con);
+int reverse_dns_lookup(char *ip_addr, char *host);

include/error.h

@@ -0,0 +1,3 @@
+#pragma once
+
+int err(char *str);

include/interface.h

@@ -0,0 +1,3 @@
+#pragma once
+
+char *get_interface_name(void);

include/print.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void print_usage(void);

include/scan.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef enum {
+	SCAN_SYN,
+	SCAN_NULL,
+	SCAN_ACK,
+	SCAN_FIN,
+	SCAN_XMAS,
+	SCAN_UDP,
+	SCAN_TCP,
+} e_scantype;
+
+int routine(const char *ip_addr, e_scantype type, uint16_t min_port,
+            uint16_t max_port);