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/*
* directconnect.c
*
* Copyright (C) 2009-11 - ipoque GmbH
* Copyright (C) 2011-21 - ntop.org
*
* This file is part of nDPI, an open source deep packet inspection
* library based on the OpenDPI and PACE technology by ipoque GmbH
*
* nDPI 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.
*
* nDPI 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 nDPI. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "ndpi_protocol_ids.h"
#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_DIRECTCONNECT
#include "ndpi_api.h"
//#define NDPI_DEBUG_DIRECTCONNECT
//#define NDPI_DIRECTCONNECT_PORT_DEBUG
//#define NDPI_DEBUG_DIRECTCONNECT_CONN
#define DIRECT_CONNECT_TYPE_HUB 0
#define DIRECT_CONNECT_TYPE_PEER 1
#define DIRECT_CONNECT_ADC_PEER 2
static u_int32_t skip_unknown_headers(const u_int8_t * payload, u_int32_t payload_len, u_int32_t pos)
{
u_int32_t i = pos;
while (i < payload_len && payload[i] != 0x0a)
i++;
i++;
return i;
}
static u_int16_t parse_binf_message(struct ndpi_detection_module_struct
*ndpi_struct, const u_int8_t * payload, uint32_t payload_len)
{
u_int32_t i = 4;
u_int16_t bytes_read = 0;
u_int16_t ssl_port = 0;
while (i < payload_len) {
i = skip_unknown_headers(payload, payload_len, i);
if((i + 30) < payload_len) {
if(memcmp(&payload[i], "DCTM", 4) == 0) {
if(memcmp(&payload[i + 15], "ADCS", 4) == 0) {
ssl_port = ntohs_ndpi_bytestream_to_number(&payload[i + 25], 5, &bytes_read);
NDPI_LOG_DBG2(ndpi_struct, "DC ssl port parsed %d\n", ssl_port);
}
}
} else {
break;
}
}
return ssl_port;
}
static void ndpi_int_directconnect_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow,
const u_int8_t connection_type)
{
struct ndpi_packet_struct *packet = &ndpi_struct->packet;
struct ndpi_id_struct *src = flow->src;
struct ndpi_id_struct *dst = flow->dst;
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
if(src != NULL) {
src->directconnect_last_safe_access_time = packet->current_time_ms;
if(connection_type == DIRECT_CONNECT_TYPE_PEER) {
if(packet->tcp != NULL
&& flow->setup_packet_direction != packet->packet_direction && src->detected_directconnect_port == 0) {
src->detected_directconnect_port = packet->tcp->source;
NDPI_LOG_DBG2(ndpi_struct, "DC tcp PORT %u for src\n", ntohs(src->detected_directconnect_port));
}
if(packet->udp != NULL && src->detected_directconnect_udp_port == 0) {
src->detected_directconnect_udp_port = packet->udp->source;
NDPI_LOG_DBG2(ndpi_struct, "DC udp PORT %u for src\n", ntohs(src->detected_directconnect_port));
}
}
}
if(dst != NULL) {
dst->directconnect_last_safe_access_time = packet->current_time_ms;
if(connection_type == DIRECT_CONNECT_TYPE_PEER) {
if(packet->tcp != NULL
&& flow->setup_packet_direction == packet->packet_direction && dst->detected_directconnect_port == 0) {
/* DST PORT MARKING CAN LEAD TO PORT MISSDETECTIONS
* seen at large customer http servers, where someone has send faked DC tcp packets
* to the server
*/
/*
dst->detected_directconnect_port = packet->tcp->dest;
NDPI_LOG_DBG2(ndpi_struct,
"DC tcp PORT %u for dst\n",
ntohs (dst->detected_directconnect_port));
*/
}
}
}
}
static void ndpi_search_directconnect_tcp(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow) {
struct ndpi_packet_struct *packet = &ndpi_struct->packet;
struct ndpi_id_struct *src = flow->src;
struct ndpi_id_struct *dst = flow->dst;
if(flow->detected_protocol_stack[0] == NDPI_PROTOCOL_DIRECTCONNECT) {
if(packet->payload_packet_len >= 40 && memcmp(&packet->payload[0], "BINF", 4) == 0) {
u_int16_t ssl_port = parse_binf_message(ndpi_struct,
&packet->payload[4],
packet->payload_packet_len - 4);
if(dst != NULL && ssl_port)
dst->detected_directconnect_ssl_port = ssl_port;
if(src != NULL && ssl_port)
src->detected_directconnect_ssl_port = ssl_port;
}
if((packet->payload_packet_len >= 38 && packet->payload_packet_len <= 42)
&& memcmp(&packet->payload[0], "DCTM", 4) == 0 && memcmp(&packet->payload[15], "ADCS", 4) == 0) {
u_int16_t bytes_read = 0;
if(dst != NULL) {
dst->detected_directconnect_ssl_port =
ntohs_ndpi_bytestream_to_number(&packet->payload[25], 5, &bytes_read);
NDPI_LOG_DBG2(ndpi_struct, "DC ssl port parsed %d\n", ntohs(dst->detected_directconnect_ssl_port));
}
if(src != NULL) {
src->detected_directconnect_ssl_port =
ntohs_ndpi_bytestream_to_number(&packet->payload[25], 5, &bytes_read);
NDPI_LOG_DBG2(ndpi_struct, "DC ssl port parsed %d\n", ntohs(src->detected_directconnect_ssl_port));
}
}
return;
}
if(src != NULL) {
if(src->detected_directconnect_port == packet->tcp->source) {
if((u_int32_t)
(packet->current_time_ms -
src->directconnect_last_safe_access_time) < ndpi_struct->directconnect_connection_ip_tick_timeout) {
src->directconnect_last_safe_access_time = packet->current_time_ms;
NDPI_LOG_INFO(ndpi_struct, "found DC using port %d\n", ntohs(src->detected_directconnect_port));
ndpi_int_change_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
return;
} else {
src->detected_directconnect_port = 0;
NDPI_LOG_DBG2(ndpi_struct, "resetting src port due to timeout\n");
return;
}
}
if(src->detected_directconnect_ssl_port == packet->tcp->dest) {
if((u_int32_t)
(packet->current_time_ms -
src->directconnect_last_safe_access_time) < ndpi_struct->directconnect_connection_ip_tick_timeout) {
src->directconnect_last_safe_access_time = packet->current_time_ms;
NDPI_LOG_INFO(ndpi_struct, "found DC using port %d\n", ntohs(src->detected_directconnect_ssl_port));
ndpi_int_change_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
return;
} else {
src->detected_directconnect_ssl_port = 0;
NDPI_LOG_DBG2(ndpi_struct, "resetting src port due to timeout\n");
return;
}
}
}
if(dst != NULL) {
if(dst->detected_directconnect_port == packet->tcp->dest) {
if((u_int32_t)
(packet->current_time_ms -
dst->directconnect_last_safe_access_time) < ndpi_struct->directconnect_connection_ip_tick_timeout) {
dst->directconnect_last_safe_access_time = packet->current_time_ms;
NDPI_LOG_INFO(ndpi_struct, "found DC using port %d\n", ntohs(dst->detected_directconnect_port));
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
return;
} else {
dst->detected_directconnect_port = 0;
NDPI_LOG_DBG(ndpi_struct, "resetting dst port due to timeout\n");
return;
}
}
if(dst->detected_directconnect_ssl_port == packet->tcp->dest) {
if((u_int32_t)
(packet->current_time_ms -
dst->directconnect_last_safe_access_time) < ndpi_struct->directconnect_connection_ip_tick_timeout) {
dst->directconnect_last_safe_access_time = packet->current_time_ms;
NDPI_LOG_DBG(ndpi_struct, "found DC using port %d\n", ntohs(dst->detected_directconnect_ssl_port));
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
return;
} else {
dst->detected_directconnect_ssl_port = 0;
NDPI_LOG_DBG2(ndpi_struct, "resetting dst port due to timeout\n");
return;
}
}
}
if(flow->directconnect_stage == 0) {
if(packet->payload_packet_len > 6) {
if(packet->payload[0] == '$'
&& packet->payload[packet->payload_packet_len - 1] == '|'
&& (memcmp(&packet->payload[1], "Lock ", 5) == 0)) {
NDPI_LOG_DBG2(ndpi_struct, "maybe first dc connect to hub detected\n");
flow->directconnect_stage = 1;
return;
}
if(packet->payload_packet_len > 7
&& packet->payload[0] == '$'
&& packet->payload[packet->payload_packet_len - 1] == '|'
&& (memcmp(&packet->payload[1], "MyNick ", 7) == 0)) {
NDPI_LOG_DBG2(ndpi_struct, "maybe first dc connect between peers detected\n");
flow->directconnect_stage = 2;
return;
}
}
if(packet->payload_packet_len >= 11) {
/* did not see this pattern in any trace */
if(memcmp(&packet->payload[0], "HSUP ADBAS0", 11) == 0
|| memcmp(&packet->payload[0], "HSUP ADBASE", 11) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC HSUP ADBAS0 E\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_HUB);
return;
/* did not see this pattern in any trace */
} else if(memcmp(&packet->payload[0], "CSUP ADBAS0", 11) == 0 ||
memcmp(&packet->payload[0], "CSUP ADBASE", 11) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC CSUP ADBAS0 E\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_ADC_PEER);
return;
}
}
} else if(flow->directconnect_stage == 1) {
if(packet->payload_packet_len >= 11) {
/* did not see this pattern in any trace */
if(memcmp(&packet->payload[0], "HSUP ADBAS0", 11) == 0
|| memcmp(&packet->payload[0], "HSUP ADBASE", 11) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC HSUP ADBAS E in second packet\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_HUB);
return;
/* did not see this pattern in any trace */
} else if(memcmp(&packet->payload[0], "CSUP ADBAS0", 11) == 0 ||
memcmp(&packet->payload[0], "CSUP ADBASE", 11) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC HSUP ADBAS0 E in second packet\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_ADC_PEER);
return;
}
}
/* get client hello answer or server message */
if(packet->payload_packet_len > 6) {
if((packet->payload[0] == '$' || packet->payload[0] == '<')
&& packet->payload[packet->payload_packet_len - 1] == '|') {
NDPI_LOG_INFO(ndpi_struct, "found DC second\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_HUB);
return;
} else {
NDPI_LOG_DBG2(ndpi_struct, "second dc not detected\n");
}
}
} else if(flow->directconnect_stage == 2) {
/* get client hello answer or server message */
if(packet->payload_packet_len > 6) {
if(packet->payload[0] == '$' && packet->payload[packet->payload_packet_len - 1] == '|') {
NDPI_LOG_INFO(ndpi_struct, "found DC between peers\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_PEER);
return;
} else {
NDPI_LOG_DBG2(ndpi_struct, "second dc between peers not detected\n");
}
}
}
NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
}
static void ndpi_search_directconnect_udp(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &ndpi_struct->packet;
struct ndpi_id_struct *src = flow->src;
struct ndpi_id_struct *dst = flow->dst;
int pos, count = 0;
if(dst != NULL && dst->detected_directconnect_udp_port == packet->udp->dest) {
if((u_int32_t)
(packet->current_time_ms -
dst->directconnect_last_safe_access_time) < ndpi_struct->directconnect_connection_ip_tick_timeout) {
dst->directconnect_last_safe_access_time = packet->current_time_ms;
NDPI_LOG_INFO(ndpi_struct, "found DC using udp port %d\n", ntohs(dst->detected_directconnect_udp_port));
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_DIRECTCONNECT, NDPI_PROTOCOL_UNKNOWN);
return;
} else {
dst->detected_directconnect_udp_port = 0;
NDPI_LOG_DBG2(ndpi_struct, "resetting dst udp port due to timeout\n");
return;
}
}
if(packet->payload_packet_len > 58) {
if(src != NULL
&& NDPI_COMPARE_PROTOCOL_TO_BITMASK(src->detected_protocol_bitmask, NDPI_PROTOCOL_DIRECTCONNECT)) {
if(packet->payload[0] == '$'
&& packet->payload[packet->payload_packet_len - 1] == '|'
&& memcmp(&packet->payload[1], "SR ", 3) == 0) {
pos = packet->payload_packet_len - 2;
if(packet->payload[pos] == ')') {
while (pos > 0 && packet->payload[pos] != '(' && count < 21) {
pos--;
count++;
}
if(packet->payload[pos] == '(') {
pos = pos - 44;
if(pos > 2 && memcmp(&packet->payload[pos], "TTH:", 4) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC udp\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_PEER);
return;
}
}
}
flow->directconnect_stage++;
if(flow->directconnect_stage < 3)
return;
}
}
if(dst != NULL
&& NDPI_COMPARE_PROTOCOL_TO_BITMASK(dst->detected_protocol_bitmask, NDPI_PROTOCOL_DIRECTCONNECT)) {
if(packet->payload[0] == '$'
&& packet->payload[packet->payload_packet_len - 1] == '|'
&& memcmp(&packet->payload[1], "SR ", 3) == 0) {
pos = packet->payload_packet_len - 2;
if(packet->payload[pos] == ')') {
while (pos > 0 && packet->payload[pos] != '(' && count < 21) {
pos--;
count++;
}
if(packet->payload[pos] == '(') {
pos = pos - 44;
if(pos > 2 && memcmp(&packet->payload[pos], "TTH:", 4) == 0) {
NDPI_LOG_INFO(ndpi_struct, "found DC udp\n");
ndpi_int_directconnect_add_connection(ndpi_struct, flow, DIRECT_CONNECT_TYPE_PEER);
return;
}
}
}
flow->directconnect_stage++;
if(flow->directconnect_stage < 3)
return;
}
}
}
NDPI_LOG_DBG(ndpi_struct, "excluded DC at stage %d \n", flow->directconnect_stage);
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_DIRECTCONNECT);
}
void ndpi_search_directconnect(struct ndpi_detection_module_struct
*ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &ndpi_struct->packet;
struct ndpi_id_struct *src = flow->src;
struct ndpi_id_struct *dst = flow->dst;
NDPI_LOG_DBG(ndpi_struct, "search DC\n");
if(flow->detected_protocol_stack[0] == NDPI_PROTOCOL_DIRECTCONNECT) {
if(src != NULL && ((u_int32_t)
(packet->current_time_ms -
src->directconnect_last_safe_access_time) <
ndpi_struct->directconnect_connection_ip_tick_timeout)) {
src->directconnect_last_safe_access_time = packet->current_time_ms;
} else if(dst != NULL && ((u_int32_t)
(packet->current_time_ms -
dst->directconnect_last_safe_access_time) <
ndpi_struct->directconnect_connection_ip_tick_timeout)) {
dst->directconnect_last_safe_access_time = packet->current_time_ms;
} else {
flow->detected_protocol_stack[0] = NDPI_PROTOCOL_UNKNOWN;
NDPI_LOG_DBG2(ndpi_struct, "skipping as unknown due to timeout\n");
}
return;
}
if(packet->tcp != NULL) {
ndpi_search_directconnect_tcp(ndpi_struct, flow);
} else if(packet->udp != NULL) {
ndpi_search_directconnect_udp(ndpi_struct, flow);
}
}
void init_directconnect_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
ndpi_set_bitmask_protocol_detection("DirectConnect", ndpi_struct, detection_bitmask, *id,
NDPI_PROTOCOL_DIRECTCONNECT,
ndpi_search_directconnect,
NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
SAVE_DETECTION_BITMASK_AS_UNKNOWN,
ADD_TO_DETECTION_BITMASK);
*id += 1;
}
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