+/*
+ * Internet Protocol (IP) + UDP header.
+ */
+struct ip_udp_hdr {
+ uchar ip_hl_v; /* header length and version */
+ uchar ip_tos; /* type of service */
+ ushort ip_len; /* total length */
+ ushort ip_id; /* identification */
+ ushort ip_off; /* fragment offset field */
+ uchar ip_ttl; /* time to live */
+ uchar ip_p; /* protocol */
+ ushort ip_sum; /* checksum */
+ IPaddr_t ip_src; /* Source IP address */
+ IPaddr_t ip_dst; /* Destination IP address */
+ ushort udp_src; /* UDP source port */
+ ushort udp_dst; /* UDP destination port */
+ ushort udp_len; /* Length of UDP packet */
+ ushort udp_xsum; /* Checksum */
+};
+
+#define IP_UDP_HDR_SIZE (sizeof(struct ip_udp_hdr))
+#define UDP_HDR_SIZE (IP_UDP_HDR_SIZE - IP_HDR_SIZE)