int
pkt_push_udp_and_ip(lbuf_t *b, uint16_t sp, uint16_t dp, ip_addr_t *sip,
ip_addr_t *dip)
{
uint16_t udpsum;
struct udphdr *uh;
if (pkt_push_udp(b, sp, dp) == NULL) {
OOR_LOG(LDBG_1, "Failed to push UDP header! Discarding");
return(BAD);
}
lbuf_reset_udp(b);
if (pkt_push_ip(b, sip, dip, IPPROTO_UDP) == NULL) {
OOR_LOG(LDBG_1, "Failed to push IP header! Discarding");
return(BAD);
}
lbuf_reset_ip(b);
uh = lbuf_udp(b);
udpsum = udp_checksum(uh, ntohs(uh->len), lbuf_ip(b), ip_addr_afi(sip));
if (udpsum == -1) {
OOR_LOG(LDBG_1, "Failed UDP checksum! Discarding");
return (BAD);
}
udpsum(uh) = udpsum;
return(GOOD);
}
int
tun_read_and_decap_pkt(int sock, lbuf_t *b, uint32_t *iid)
{
uint8_t ttl = 0, tos = 0;
int afi;
struct udphdr *udph;
lisp_data_hdr_t *lisph;
vxlan_gpe_hdr_t *vxlanh;
int port;
if (sock_data_recv(sock, b, &afi, &ttl, &tos) != GOOD) {
return(BAD);
}
if (afi == AF_INET){
/* With input RAW UDP sockets in IPv4, we get the whole external
* IPv4 packet */
lbuf_reset_ip(b);
pkt_pull_ip(b);
lbuf_reset_udp(b);
}else{
/* With input RAW UDP sockets in IPv6, we get the whole external
* UDP packet */
lbuf_reset_udp(b);
}
udph = pkt_pull_udp(b);
/* FILTER UDP: with input RAW UDP sockets, we receive all UDP packets,
* we only want LISP data ones */
switch (ntohs(udph->dest)){
case LISP_DATA_PORT:
lisph = lisp_data_pull_hdr(b);
if (LDHDR_LSB_BIT(lisph)){
*iid = lisp_data_hdr_get_iid(lisph);
}else{
*iid = 0;
}
port = LISP_DATA_PORT;
break;
case VXLAN_GPE_DATA_PORT:
vxlanh = vxlan_gpe_data_pull_hdr(b);
if (VXLAN_HDR_VNI_BIT(vxlanh)){
*iid = vxlan_gpe_hdr_get_vni(vxlanh);
}
port = VXLAN_GPE_DATA_PORT;
break;
default:
return (ERR_NOT_ENCAP);
}
/* RESET L3: prepare for output */
lbuf_reset_l3(b);
/* UPDATE IP TOS and TTL. Checksum is also updated for IPv4
* NOTE: we always assume an IP payload*/
ip_hdr_set_ttl_and_tos(lbuf_data(b), ttl, tos);
OOR_LOG(LDBG_3, "INPUT (%d): %s",port, ip_src_and_dst_to_char(lbuf_l3(b),
"Inner IP: %s -> %s"));
return(GOOD);
}