+ /*
+ * Calculate the size of the TCP/IP header and make sure that
+ * we don't overflow the space we have available for it.
+ */
+ hlen = ip->ip_hl << 2;
+ if (hlen + sizeof(struct tcphdr) > buflen)
+ goto bad;
+ hlen += ((struct tcphdr *)&((char *)ip)[hlen])->th_off << 2;
+ if (hlen > MAX_HDR || hlen > buflen)
+ goto bad;