/*
* tun_add_eid_to_iface()
*
* Add an EID to the TUN/TAP interface
*/
int tun_add_eid_to_iface(
lisp_addr_t eid_address,
char *dev_name)
{
struct rtattr *rta = NULL;
struct ifaddrmsg *ifa = NULL;
struct nlmsghdr *nlh = NULL;
char sndbuf[4096];
int retval = 0;
int sockfd = 0;
int ifindex = 0;
int addr_size = 0;
int prefix_length = 0;
ifindex = if_nametoindex (dev_name);
sockfd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
if (sockfd < 0) {
lispd_log_msg(LISP_LOG_ERR, "tun_add_eid_to_iface: Failed to connect to netlink socket");
return(BAD);
}
if (eid_address.afi == AF_INET){
addr_size = sizeof(struct in_addr);
prefix_length = 32;
}else {
addr_size = sizeof(struct in6_addr);
prefix_length = 128;
}
/*
* Build the command
*/
memset(sndbuf, 0, 4096);
nlh = (struct nlmsghdr *)sndbuf;
nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg) + sizeof(struct rtattr) + addr_size);
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE;
nlh->nlmsg_type = RTM_NEWADDR;
ifa = (struct ifaddrmsg *)(sndbuf + sizeof(struct nlmsghdr));
ifa->ifa_prefixlen = prefix_length;
ifa->ifa_family = eid_address.afi;
ifa->ifa_index = ifindex;
ifa->ifa_scope = RT_SCOPE_UNIVERSE;
ifa->ifa_flags = 0; // Bring it up
rta = (struct rtattr *)(sndbuf + sizeof(struct nlmsghdr) + sizeof(struct ifaddrmsg));
rta->rta_type = IFA_LOCAL;
rta->rta_len = sizeof(struct rtattr) + addr_size;
memcopy_lisp_addr((void *)((char *)rta + sizeof(struct rtattr)),&eid_address);
retval = send(sockfd, sndbuf, nlh->nlmsg_len, 0);
if (retval < 0) {
lispd_log_msg(LISP_LOG_ERR, "tun_add_eid_to_iface: send() failed %s", strerror(errno));
close(sockfd);
return(BAD);
}
lispd_log_msg(LISP_LOG_DEBUG_1, "added %s EID to TUN interface.",get_char_from_lisp_addr_t(eid_address));
close(sockfd);
return(GOOD);
}
void add_ip_header (
char *position,
char *original_packet_position,
int ip_payload_length,
lisp_addr_t *src_addr,
lisp_addr_t *dst_addr)
{
struct iphdr *iph = NULL;
struct iphdr *inner_iph = NULL;
struct ip6_hdr *ip6h = NULL;
struct ip6_hdr *inner_ip6h = NULL;
uint8_t tos = 0;
uint8_t ttl = 0;
inner_iph = (struct iphdr *) original_packet_position;
/* We SHOULD copy ttl and tos fields from the inner packet to the encapsulated one */
if (inner_iph->version == 4 ) {
tos = inner_iph->tos;
ttl = inner_iph->ttl;
} else {
inner_ip6h = (struct ip6_hdr *) original_packet_position;
ttl = inner_ip6h->ip6_hops; /* ttl = Hops limit in IPv6 */
//tos = (inner_ip6h->ip6_flow & 0x0ff00000) >> 20; /* 4 bits version, 8 bits Traffic Class, 20 bits flow-ID */
tos = IPV6_GET_TC(*inner_ip6h); /* tos = Traffic class field in IPv6 */
}
/*
* Construct and add the outer ip header
*/
switch (dst_addr->afi){
case AF_INET:
iph = (struct iphdr *) position;
iph->version = 4;
//iph->ihl = sizeof ( struct iphdr ) >>2;
iph->ihl = 5; /* Minimal IPv4 header */ /*XXX Beware, hardcoded. Supposing no IP options */
iph->tos = tos;
iph->tot_len = htons(ip_payload_length);
iph->frag_off = htons(IP_DF); /* Do not fragment flag. See 5.4.1 in LISP RFC (6830) */
iph->ttl = ttl;
iph->protocol = IPPROTO_UDP;
iph->check = 0; //Computed by the NIC (checksum offloading)
iph->daddr = dst_addr->address.ip.s_addr;
iph->saddr = src_addr->address.ip.s_addr;
break;
case AF_INET6:
ip6h = ( struct ip6_hdr *) position;
IPV6_SET_VERSION(ip6h, 6);
IPV6_SET_TC(ip6h,tos);
IPV6_SET_FLOW_LABEL(ip6h,0);
ip6h->ip6_plen = htons(ip_payload_length);
ip6h->ip6_nxt = IPPROTO_UDP;
ip6h->ip6_hops = ttl;
memcopy_lisp_addr(&(ip6h->ip6_dst),dst_addr);
memcopy_lisp_addr(&(ip6h->ip6_src),src_addr);
break;
default:
break;
}
}
