RESULT ip_process( ip_header_p iph, SHORT len )
{
DECLARE( SHORT, data_len, 0 );
DECLARE( BYTE, j, 0 );
DECLARE( WORD, dst, 0 );
if( len < sizeof( ip_header ) )
{
return IP_HEADER_LEN_TOO_SMALL;
}
dst = R_STRUCT_VAR_TYPE( WORD, iph->dst );
if( dst != R_WORD( __IP, 0 ) )
{
return IP_HEADER_DST_NOT_ME;
}
data_len = get_ip_data_len( iph );
if( data_len == 0 )
{
return IP_HEADER_DATA_LEN_ZERO;
}
if( data_len > MAX_IP_DATA_LEN )
{
return IP_HEADER_DATA_LEN_TOO_BIG;
}
if( data_len != len )
{
return IP_HEADER_AND_ACTUAL_LEN_MISMATCH;
}
j = get_ip_header_len( iph );
if( j > data_len )
{
return IP_HEADER_LEN_BIGGER_THAN_PKT;
}
for ( j = 0; j < sizeof( supported_ip_protocols );
j++ )
{
if( supported_ip_protocols[ j ]
== iph->protocol )
break;
}
if( j == sizeof( supported_ip_protocols ) )
{
return IP_HEADER_PROTO_NOT_SUPPORTED;
}
return OK;
}
uint8_t *build_ip_udp_pcket(
uint8_t *orig_pkt,
int orig_pkt_len,
lisp_addr_t *addr_from,
lisp_addr_t *addr_dest,
int port_from,
int port_dest,
int *encap_pkt_len)
{
uint8_t *encap_pkt = NULL;
void *iph_ptr = NULL;
struct udphdr *udph_ptr = NULL;
int ip_hdr_len = 0;
int udp_hdr_len = 0;
int udp_hdr_and_payload_len = 0;
uint16_t udpsum = 0;
if (addr_from->afi != addr_dest->afi) {
lispd_log_msg(LISP_LOG_DEBUG_2, "add_ip_udp_header: Different AFI addresses");
return (NULL);
}
if ((addr_from->afi != AF_INET) && (addr_from->afi != AF_INET6)) {
lispd_log_msg(LISP_LOG_DEBUG_2, "add_ip_udp_header: Unknown AFI %d",
addr_from->afi);
return (NULL);
}
/* Headers lengths */
ip_hdr_len = get_ip_header_len(addr_from->afi);
udp_hdr_len = sizeof(struct udphdr);
udp_hdr_and_payload_len = udp_hdr_len + orig_pkt_len;
/* Assign memory for the original packet plus the new headers */
*encap_pkt_len = ip_hdr_len + udp_hdr_len + orig_pkt_len;
if ((encap_pkt = (uint8_t *) malloc(*encap_pkt_len)) == NULL) {
lispd_log_msg(LISP_LOG_DEBUG_2, "add_ip_udp_header: Couldn't allocate memory for the packet to be generated %s", strerror(errno));
return (NULL);
}
/* Make sure it's clean */
memset(encap_pkt, 0, *encap_pkt_len);
/* IP header */
iph_ptr = encap_pkt;
if ((udph_ptr = build_ip_header(iph_ptr, addr_from, addr_dest, udp_hdr_and_payload_len)) == NULL){
lispd_log_msg(LISP_LOG_DEBUG_2, "add_ip_udp_header: Couldn't build the inner ip header");
free (encap_pkt);
return (NULL);
}
/* UDP header */
#ifdef BSD
udph_ptr->uh_sport = htons(port_from);
udph_ptr->uh_dport = htons(port_dest);
udph_ptr->uh_ulen = htons(udp_payload_len);
udph_ptr->uh_sum = 0;
#else
udph_ptr->source = htons(port_from);
udph_ptr->dest = htons(port_dest);
udph_ptr->len = htons(udp_hdr_and_payload_len);
udph_ptr->check = 0;
#endif
/* Copy original packet after the headers */
memcpy(CO(udph_ptr, udp_hdr_len), orig_pkt, orig_pkt_len);
/*
* Now compute the headers checksums
*/
if ((udpsum = udp_checksum(udph_ptr, udp_hdr_and_payload_len, iph_ptr, addr_from->afi)) == -1) {
free (encap_pkt);
return (NULL);
}
udpsum(udph_ptr) = udpsum;
return (encap_pkt);
}
