- /*
- * Checksum extended TCP header and data.
- */
- tlen = ((struct ip *)ti)->ip_len;
- tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
- memset(&ti->ti_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
- ti->ti_x1 = 0;
- ti->ti_len = htons((uint16_t)tlen);
- len = sizeof(struct ip ) + tlen;
- if(cksum(m, len)) {
- goto drop;
+ /*
+ * Save a copy of the IP header in case we want restore it
+ * for sending an ICMP error message in response.
+ */
+ save_ip = *ip;
+ save_ip.ip_len += iphlen;
+
+ /*
+ * Get IP and TCP header together in first mbuf.
+ * Note: IP leaves IP header in first mbuf.
+ */
+ m->m_data -= sizeof(struct tcpiphdr) - sizeof(struct ip)
+ - sizeof(struct tcphdr);
+ m->m_len += sizeof(struct tcpiphdr) - sizeof(struct ip)
+ - sizeof(struct tcphdr);
+ ti = mtod(m, struct tcpiphdr *);
+
+ /*
+ * Checksum extended TCP header and data.
+ */
+ tlen = ip->ip_len;
+ tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
+ memset(&ti->ih_mbuf, 0 , sizeof(struct mbuf_ptr));
+ memset(&ti->ti, 0, sizeof(ti->ti));
+ ti->ti_x0 = 0;
+ ti->ti_src = save_ip.ip_src;
+ ti->ti_dst = save_ip.ip_dst;
+ ti->ti_pr = save_ip.ip_p;
+ ti->ti_len = htons((uint16_t)tlen);
+ break;
+
+ case AF_INET6:
+ /*
+ * Save a copy of the IP header in case we want restore it
+ * for sending an ICMP error message in response.
+ */
+ save_ip6 = *ip6;
+ /*
+ * Get IP and TCP header together in first mbuf.
+ * Note: IP leaves IP header in first mbuf.
+ */
+ m->m_data -= sizeof(struct tcpiphdr) - (sizeof(struct ip6)
+ + sizeof(struct tcphdr));
+ m->m_len += sizeof(struct tcpiphdr) - (sizeof(struct ip6)
+ + sizeof(struct tcphdr));
+ ti = mtod(m, struct tcpiphdr *);
+
+ tlen = ip6->ip_pl;
+ tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
+ memset(&ti->ih_mbuf, 0 , sizeof(struct mbuf_ptr));
+ memset(&ti->ti, 0, sizeof(ti->ti));
+ ti->ti_x0 = 0;
+ ti->ti_src6 = save_ip6.ip_src;
+ ti->ti_dst6 = save_ip6.ip_dst;
+ ti->ti_nh6 = save_ip6.ip_nh;
+ ti->ti_len = htons((uint16_t)tlen);
+ break;
+
+ default:
+ g_assert_not_reached();
+ }
+
+ len = ((sizeof(struct tcpiphdr) - sizeof(struct tcphdr)) + tlen);
+ if (cksum(m, len)) {
+ goto drop;