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/*
* quic.c
*
* Andrea Buscarinu - <andrea.buscarinu@gmail.com>
* Michele Campus - <campus@ntop.org>
*
* Copyright (C) 2012-15 - ntop.org
*
* This module 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.
*
* This module 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.
* If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "ndpi_api.h"
#define QUIC_NO_V_RES_RSV 0xC3 // 1100 0011
#define QUIC_CID_MASK 0x0C // 0000 1100
#define QUIC_VER_MASK 0x01 // 0000 0001
#define QUIC_SEQ_MASK 0x30 // 0011 0000
#define CID_LEN_8 0x0C // 0000 1100
#define CID_LEN_4 0x08 // 0000 1000
#define CID_LEN_1 0x04 // 0000 0100
#define CID_LEN_0 0x00 // 0000 0000
#define SEQ_LEN_6 0x30 // 0011 0000
#define SEQ_LEN_4 0x20 // 0010 0000
#define SEQ_LEN_2 0x10 // 0001 0000
#define SEQ_LEN_1 0x00 // 0000 0000
#define SEQ_CONV(ARR) (ARR[0] | ARR[1] | ARR[2] | ARR[3] | ARR[4] | ARR[5] << 8)
#ifdef NDPI_PROTOCOL_QUIC
static void ndpi_int_quic_add_connection(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_QUIC, NDPI_PROTOCOL_UNKNOWN);
}
static int connect_id(const unsigned char pflags)
{
u_int cid_len;
// Check CID length.
switch (pflags & QUIC_CID_MASK)
{
case CID_LEN_8: cid_len = 8; break;
case CID_LEN_4: cid_len = 4; break;
case CID_LEN_1: cid_len = 1; break;
case CID_LEN_0: cid_len = 0; break;
default:
return -1;
}
// Return offset.
return cid_len + 1;
}
static int sequence(const unsigned char *payload)
{
unsigned char conv[6] = {0};
u_int seq_value = -1;
int seq_lens;
int cid_offs;
int i;
// Search SEQ bytes length.
switch (payload[0] & QUIC_SEQ_MASK)
{
case SEQ_LEN_6: seq_lens = 6; break;
case SEQ_LEN_4: seq_lens = 4; break;
case SEQ_LEN_2: seq_lens = 2; break;
case SEQ_LEN_1: seq_lens = 1; break;
default:
return -1;
}
// Retrieve SEQ offset.
cid_offs = connect_id(payload[0]);
if (cid_offs >= 0 && seq_lens > 0)
{
for (i = 0; i < seq_lens; i++)
conv[i] = payload[cid_offs + i];
seq_value = SEQ_CONV(conv);
}
// Return SEQ dec value;
return seq_value;
}
void ndpi_search_quic(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
int ver_offs;
if(packet->udp != NULL) {
u_int16_t sport = ntohs(packet->udp->source), dport = ntohs(packet->udp->dest);
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "calculating quic over udp.\n");
if((((sport == 80) || (dport == 80) || (sport == 443) || (dport == 443))))
{
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
// Settings without version. First check if PUBLIC FLAGS & SEQ bytes are 0x0. SEQ must be 1 at least.
if ((packet->payload[0] == 0x00 && packet->payload[1] != 0x00) || ((packet->payload[0] & QUIC_NO_V_RES_RSV) == 0))
{
if (sequence(packet->payload) < 1)
{
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
}
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
ndpi_int_quic_add_connection(ndpi_struct, flow);
}
// Check if version, than the CID length.
else if (packet->payload[0] & QUIC_VER_MASK)
{
// Skip CID length.
ver_offs = connect_id(packet->payload[0]);
if (ver_offs >= 0)
{
unsigned char vers[] = {packet->payload[ver_offs], packet->payload[ver_offs + 1],
packet->payload[ver_offs + 2], packet->payload[ver_offs + 3]};
// Version Match.
if ((vers[0] == 'Q' && vers[1] == '0') &&
((vers[2] == '2' && (vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
vers[3] == '1' || vers[3] == '0')) ||
(vers[2] == '1' && (vers[3] == '9' || vers[3] == '8' || vers[3] == '7' || vers[3] == '6' ||
vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
vers[3] == '1' || vers[3] == '0')) ||
(vers[2] == '0' && vers[3] == '9')))
{
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
ndpi_int_quic_add_connection(ndpi_struct, flow);
}
}
}
}
else
{
NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
}
}
}
#endif
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