ushort udp_xsum; /* Checksum */
} IP_t;
+#define IP_OFFS 0x1fff /* ip offset *= 8 */
+#define IP_FLAGS 0xe000 /* first 3 bits */
+#define IP_FLAGS_RES 0x8000 /* reserved */
+#define IP_FLAGS_DFRAG 0x4000 /* don't fragments */
+#define IP_FLAGS_MFRAG 0x2000 /* more fragments */
+
#define IP_HDR_SIZE_NO_UDP (sizeof (IP_t) - 8)
#define IP_HDR_SIZE (sizeof (IP_t))
ip->ip_tos = 0;
ip->ip_len = htons(IP_HDR_SIZE_NO_UDP + 8);
ip->ip_id = htons(NetIPID++);
- ip->ip_off = htons(0x4000); /* No fragmentation */
+ ip->ip_off = htons(IP_FLAGS_DFRAG); /* Don't fragment */
ip->ip_ttl = 255;
ip->ip_p = 0x01; /* ICMP */
ip->ip_sum = 0;
if ((ip->ip_hl_v & 0xf0) != 0x40) {
return;
}
- if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
+ if (ip->ip_off & htons(IP_OFFS)) { /* Can't deal w/ fragments */
return;
}
/* can't deal with headers > 20 bytes */
ip->ip_tos = 0;
ip->ip_len = htons(IP_HDR_SIZE + len);
ip->ip_id = htons(NetIPID++);
- ip->ip_off = htons(0x4000); /* No fragmentation */
+ ip->ip_off = htons(IP_FLAGS_DFRAG); /* Don't fragment */
ip->ip_ttl = 255;
ip->ip_p = 17; /* UDP */
ip->ip_sum = 0;