#define IP_VERSION 4
+#define IP_DONT_FRAGMENT 0x4000 /* Don't fragment. */
+#define IP_MORE_FRAGMENTS 0x2000 /* More fragments. */
+#define IP_FRAG_OFF_MASK 0x1fff /* Fragment offset. */
+#define IP_IS_FRAGMENT(ip_frag_off) \
+ (ntohs(ip_frag_off) & (IP_MORE_FRAGMENTS | IP_FRAG_OFF_MASK))
+
#define IP_HEADER_LEN 20
struct ip_header {
uint8_t ip_ihl_ver;