+
+int
+tnl_port_build_header(const struct ofport_dpif *ofport,
+ const struct flow *tnl_flow,
+ const struct eth_addr dmac,
+ const struct eth_addr smac,
+ const struct in6_addr * ipv6_src,
+ struct ovs_action_push_tnl *data)
+{
+ struct tnl_port *tnl_port;
+ struct eth_header *eth;
+ struct ip_header *ip;
+ struct ovs_16aligned_ip6_hdr *ip6;
+ void *l3;
+ int res;
+ ovs_be32 ip_src;
+
+ fat_rwlock_rdlock(&rwlock);
+ tnl_port = tnl_find_ofport(ofport);
+ ovs_assert(tnl_port);
+
+ ip_src = in6_addr_get_mapped_ipv4(ipv6_src);
+
+ /* Build Ethernet and IP headers. */
+ memset(data->header, 0, sizeof data->header);
+
+ eth = (struct eth_header *)data->header;
+ eth->eth_dst = dmac;
+ eth->eth_src = smac;
+ eth->eth_type = ip_src ? htons(ETH_TYPE_IP) : htons(ETH_TYPE_IPV6);
+
+ l3 = (eth + 1);
+
+ if (ip_src) {
+ ip = (struct ip_header *) l3;
+
+ ip->ip_ihl_ver = IP_IHL_VER(5, 4);
+ ip->ip_tos = tnl_flow->tunnel.ip_tos;
+ ip->ip_ttl = tnl_flow->tunnel.ip_ttl;
+ ip->ip_frag_off = (tnl_flow->tunnel.flags & FLOW_TNL_F_DONT_FRAGMENT) ?
+ htons(IP_DF) : 0;
+
+ put_16aligned_be32(&ip->ip_src, ip_src);
+ put_16aligned_be32(&ip->ip_dst, tnl_flow->tunnel.ip_dst);
+ } else {
+ ip6 = (struct ovs_16aligned_ip6_hdr *) l3;
+
+ ip6->ip6_vfc = 0x60;
+ ip6->ip6_hlim = tnl_flow->tunnel.ip_ttl;
+
+ /* next header, plen - at netdev_build_header? */
+
+ memcpy(&ip6->ip6_src, ipv6_src, sizeof(ovs_be32[4]));
+ memcpy(&ip6->ip6_dst, &tnl_flow->tunnel.ipv6_dst, sizeof(ovs_be32[4]));
+ }
+
+ res = netdev_build_header(tnl_port->netdev, data, tnl_flow);
+
+ if (ip_src) {
+ ip->ip_csum = csum(ip, sizeof *ip);
+ }
+
+ fat_rwlock_unlock(&rwlock);
+
+ return res;
+}