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/*
* rtcp.c (RTP Control Protocol)
*
* Copyright (C) 2013 Remy Mudingay <mudingay@ill.fr>
*
*/
#include "ndpi_api.h"
#ifdef NDPI_PROTOCOL_RTCP
static void ndpi_int_rtcp_add_connection(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_RTCP/* , NDPI_CORRELATED_PROTOCOL */);
}
void ndpi_search_rtcp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
u_int16_t dport = 0, sport = 0;
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "search for RTCP.\n");
if(packet->tcp != NULL) {
sport = ntohs(packet->tcp->source), dport = ntohs(packet->tcp->dest);
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "calculating dport over tcp.\n");
if(packet->payload_packet_len > 13 && (sport == 554 || dport == 554) &&
packet->payload[0] == 0x00 && packet->payload[1] == 0x00 &&
packet->payload[2] == 0x01 && packet->payload[3] == 0x01 &&
packet->payload[4] == 0x08 && packet->payload[5] == 0x0a &&
packet->payload[6] == 0x00 && packet->payload[7] == 0x01) {
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "found rtcp.\n");
ndpi_int_rtcp_add_connection(ndpi_struct, flow);
}
} else if(packet->udp != NULL) {
/* Let's check first the RTCP packet length */
u_int16_t len, offset = 0, rtcp_section_len;
while(offset < packet->payload_packet_len) {
len = packet->payload[2+offset] * 256 + packet->payload[2+offset+1];
rtcp_section_len = (len + 1) * 4;
if((offset+rtcp_section_len) > packet->payload_packet_len)
goto exclude_rtcp;
else
offset += rtcp_section_len;
}
sport = ntohs(packet->udp->source), dport = ntohs(packet->udp->dest);
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "calculating dport over udp.\n");
if(((packet->payload_packet_len >= 28 || packet->payload_packet_len <= 1200) &&
((packet->payload[0] == 0x80) && ((packet->payload[1] == 0xc8) || (packet->payload[1] == 0xc9)) && (packet->payload[2] == 0x00)))
|| (((packet->payload[0] == 0x81) && ((packet->payload[1] == 0xc8) || (packet->payload[1] == 0xc9))
&& (packet->payload[2] == 0x00)))) {
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "found rtcp.\n");
ndpi_int_rtcp_add_connection(ndpi_struct, flow);
}
} else {
exclude_rtcp:
NDPI_LOG(NDPI_PROTOCOL_RTCP, ndpi_struct, NDPI_LOG_DEBUG, "exclude RTCP.\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_RTCP);
}
}
#endif
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