hdrlen))
return -EINVAL;
- message->ip.check = message->udp.len;
- message->ip.ttl = 0;
-
- if (hdrlen + be16toh(message->udp.len) > len ||
- client_checksum(&message->ip.ttl, be16toh(message->udp.len) + 12))
+ if (hdrlen + be16toh(message->udp.len) > len)
return -EINVAL;
+ if (message->udp.check) {
+ message->ip.check = message->udp.len;
+ message->ip.ttl = 0;
+
+ if (client_checksum(&message->ip.ttl,
+ be16toh(message->udp.len) + 12))
+ return -EINVAL;
+ }
+
if (be16toh(message->udp.source) != DHCP_PORT_SERVER ||
be16toh(message->udp.dest) != DHCP_PORT_CLIENT)
return -EINVAL;