/*
* dhcp.c
* Copyright (C) 2009-2010 by ipoque GmbH
*
* This file is part of OpenDPI, an open source deep packet inspection
* library based on the PACE technology by ipoque GmbH
*
* OpenDPI is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OpenDPI is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OpenDPI. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "../ipq_protocols.h"
#ifdef IPOQUE_PROTOCOL_DHCP
static void ipoque_int_dhcp_add_connection(struct ipoque_detection_module_struct
*ipoque_struct)
{
struct ipoque_packet_struct *packet = &ipoque_struct->packet;
struct ipoque_flow_struct *flow = ipoque_struct->flow;
struct ipoque_id_struct *src = ipoque_struct->src;
struct ipoque_id_struct *dst = ipoque_struct->dst;
flow->detected_protocol = IPOQUE_PROTOCOL_DHCP;
packet->detected_protocol = IPOQUE_PROTOCOL_DHCP;
if (src != NULL) {
IPOQUE_ADD_PROTOCOL_TO_BITMASK(src->detected_protocol_bitmask, IPOQUE_PROTOCOL_DHCP);
}
if (dst != NULL) {
IPOQUE_ADD_PROTOCOL_TO_BITMASK(dst->detected_protocol_bitmask, IPOQUE_PROTOCOL_DHCP);
}
}
void ipoque_search_dhcp_udp(struct ipoque_detection_module_struct *ipoque_struct)
{
struct ipoque_packet_struct *packet = &ipoque_struct->packet;
struct ipoque_flow_struct *flow = ipoque_struct->flow;
// struct ipoque_id_struct *src=ipoque_struct->src;
// struct ipoque_id_struct *dst=ipoque_struct->dst;
/* this detection also works for asymmetric dhcp traffic */
/*check standard DHCP 0.0.0.0:68 -> 255.255.255.255:67 */
if (packet->payload_packet_len >= 244 && (packet->udp->source == htons(67)
|| packet->udp->source == htons(68))
&& (packet->udp->dest == htons(67) || packet->udp->dest == htons(68))
&& get_u32(packet->payload, 236) == htonl(0x63825363)
&& get_u16(packet->payload, 240) == htons(0x3501)) {
IPQ_LOG(IPOQUE_PROTOCOL_DHCP, ipoque_struct, IPQ_LOG_DEBUG, "DHCP request\n");
ipoque_int_dhcp_add_connection(ipoque_struct);
return;
}
IPOQUE_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, IPOQUE_PROTOCOL_DHCP);
}
#endif