- ip = (struct ip_udp_hdr *)pkt;
-
- /*
- * Construct an IP and ICMP header.
- * (need to set no fragment bit - XXX)
- */
- /* IP_HDR_SIZE / 4 (not including UDP) */
- ip->ip_hl_v = 0x45;
- ip->ip_tos = 0;
- ip->ip_len = htons(IP_HDR_SIZE_NO_UDP + 8);
- ip->ip_id = htons(NetIPID++);
- ip->ip_off = htons(IP_FLAGS_DFRAG); /* Don't fragment */
- ip->ip_ttl = 255;
- ip->ip_p = 0x01; /* ICMP */
- ip->ip_sum = 0;
- /* already in network byte order */
- NetCopyIP((void *)&ip->ip_src, &NetOurIP);
- /* - "" - */
- NetCopyIP((void *)&ip->ip_dst, &NetPingIP);
- ip->ip_sum = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
-
- s = &ip->udp_src; /* XXX ICMP starts here */
- s[0] = htons(0x0800); /* echo-request, code */
- s[1] = 0; /* checksum */
- s[2] = 0; /* identifier */
- s[3] = htons(PingSeqNo++); /* sequence number */
- s[1] = ~NetCksum((uchar *)s, 8/2);