static void ndpi_search_bittorrent(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
if (packet->detected_protocol_stack[0] != NDPI_PROTOCOL_BITTORRENT) {
/* check for tcp retransmission here */
if ((packet->tcp != NULL)
&& (packet->tcp_retransmission == 0 || packet->num_retried_bytes)) {
ndpi_int_search_bittorrent_tcp(ndpi_struct, flow);
}
else if(packet->udp != NULL) {
flow->bittorrent_stage++;
if(flow->bittorrent_stage < 10) {
if(packet->payload_packet_len > 19 /* min size */) {
char *begin;
if(ndpi_strnstr(packet->payload, ":target20:", packet->payload_packet_len)
|| ndpi_strnstr(packet->payload, ":find_node1:", packet->payload_packet_len)
|| ndpi_strnstr(packet->payload, "d1:ad2:id20:", packet->payload_packet_len)) {
bittorrent_found:
NDPI_LOG_BITTORRENT(NDPI_PROTOCOL_BITTORRENT,
ndpi_struct, NDPI_LOG_TRACE, "BT: plain BitTorrent protocol detected\n");
ndpi_add_connection_as_bittorrent(ndpi_struct, flow,
NDPI_PROTOCOL_SAFE_DETECTION, NDPI_PROTOCOL_PLAIN_DETECTION,
NDPI_REAL_PROTOCOL);
return;
} else if((begin = memchr(packet->payload, 'B', packet->payload_packet_len-19)) != NULL) {
long offset = (u_long)begin - (u_long)packet->payload;
if((packet->payload_packet_len-19) > offset) {
if(memcmp(begin, "BitTorrent protocol", 19) == 0) {
goto bittorrent_found;
}
}
}
}
return;
}
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_BITTORRENT);
}
}
}
static int matchStringProtocol(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow,
char *string_to_match,
u_int string_to_match_len) {
int i = 0, end = string_to_match_len-1, num_found = 0;
struct ndpi_packet_struct *packet = &flow->packet;
#ifdef AHOCORASICK
AC_TEXT_t ac_input_text;
#endif
while(end > 0) {
if(string_to_match[end] == '.') {
num_found++;
if(num_found == 2) {
end++;
break;
}
}
end--;
}
strncpy(flow->l4.tcp.host_server_name,
&string_to_match[end],
ndpi_min(sizeof(flow->l4.tcp.host_server_name)-1, string_to_match_len-end));
#ifdef AHOCORASICK
matching_protocol_id = -1;
ac_input_text.astring = string_to_match;
ac_input_text.length = string_to_match_len;
ac_automata_search (ac_automa, &ac_input_text, 0);
ac_automata_reset(ac_automa);
if (matching_protocol_id != -1) {
packet->detected_protocol_stack[0] = matching_protocol_id;
return(packet->detected_protocol_stack[0]);
}
#else
for (i = 0; i < host_match_num_items; i++) {
if(ndpi_strnstr(string_to_match,
host_match[i].string_to_match,
string_to_match_len) != NULL) {
packet->detected_protocol_stack[0] = host_match[i].protocol_id;
return(packet->detected_protocol_stack[0]);
} else
i++;
}
#endif
#ifdef DEBUG
string_to_match[string_to_match_len] = '\0';
printf("[NTOP] Unable to find a match for '%s'\n", string_to_match);
#endif
return(-1);
}
static void ndpi_check_citrix(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
u_int32_t payload_len = packet->payload_packet_len;
#if 0
printf("[len=%u][%02X %02X %02X %02X]\n", payload_len,
packet->payload[0] & 0xFF,
packet->payload[1] & 0xFF,
packet->payload[2] & 0xFF,
packet->payload[3] & 0xFF);
#endif
if(packet->tcp != NULL) {
flow->l4.tcp.citrix_packet_id++;
if((flow->l4.tcp.citrix_packet_id == 3)
/* We have seen the 3-way handshake */
&& flow->l4.tcp.seen_syn
&& flow->l4.tcp.seen_syn_ack
&& flow->l4.tcp.seen_ack) {
if(payload_len == 6) {
char citrix_header[] = { 0x07, 0x07, 0x49, 0x43, 0x41, 0x00 };
if(memcmp(packet->payload, citrix_header, sizeof(citrix_header)) == 0) {
NDPI_LOG(NDPI_PROTOCOL_CITRIX, ndpi_struct, NDPI_LOG_DEBUG, "Found citrix.\n");
ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_CITRIX, NDPI_REAL_PROTOCOL);
}
return;
} else if(payload_len > 4) {
char citrix_header[] = { 0x1a, 0x43, 0x47, 0x50, 0x2f, 0x30, 0x31 };
if((memcmp(packet->payload, citrix_header, sizeof(citrix_header)) == 0)
|| (ndpi_strnstr(packet->payload, "Citrix.TcpProxyService", payload_len) != NULL)) {
NDPI_LOG(NDPI_PROTOCOL_CITRIX, ndpi_struct, NDPI_LOG_DEBUG, "Found citrix.\n");
ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_CITRIX, NDPI_REAL_PROTOCOL);
}
return;
}
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_CITRIX);
} else if(flow->l4.tcp.citrix_packet_id > 3)
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_CITRIX);
return;
}
}
static void check_content_type_and_change_protocol(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow, u_int16_t x)
{
struct ndpi_packet_struct *packet = &flow->packet;
int i, left = packet->payload_packet_len-x;
if(left <= 0) return;
for(i=0; jabber_strings[i].string != NULL; i++) {
if(ndpi_strnstr((const char*)&packet->payload[x], jabber_strings[i].string, left) != NULL) {
ndpi_int_jabber_add_connection(ndpi_struct, flow, jabber_strings[i].ndpi_protocol);
return;
}
}
}
static void ndpi_add_connection_as_bittorrent(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow,
int bt_offset, int check_hash,
const u_int8_t save_detection, const u_int8_t encrypted_connection)
{
if(check_hash) {
const char *bt_hash = NULL; /* 20 bytes long */
const char *peer_id = NULL; /* 20 bytes long */
if(bt_offset == -1) {
const char *bt_magic = ndpi_strnstr((const char *)flow->packet.payload,
"BitTorrent protocol", flow->packet.payload_packet_len);
if(bt_magic)
bt_hash = &bt_magic[19], peer_id = &bt_magic[39];
} else
bt_hash = (const char*)&flow->packet.payload[28], peer_id = (const char*)&flow->packet.payload[48];
if(bt_hash) memcpy(flow->bittorent_hash, bt_hash, 20);
}
ndpi_int_change_protocol(ndpi_struct, flow, NDPI_PROTOCOL_BITTORRENT, NDPI_PROTOCOL_UNKNOWN);
}
void ndpi_search_jabber_tcp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
struct ndpi_id_struct *src = flow->src;
struct ndpi_id_struct *dst = flow->dst;
u_int16_t x;
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_TRACE, "JABBER detection....\n");
/* search for jabber file transfer */
/* this part is working asymmetrically */
if (packet->tcp != NULL && packet->tcp->syn != 0 && packet->payload_packet_len == 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "check jabber syn\n");
if (src != NULL && src->jabber_file_transfer_port[0] != 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"src jabber ft port set, ports are: %u, %u\n", ntohs(src->jabber_file_transfer_port[0]),
ntohs(src->jabber_file_transfer_port[1]));
if (((u_int32_t)
(packet->tick_timestamp - src->jabber_stun_or_ft_ts)) >= ndpi_struct->jabber_file_transfer_timeout) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "JABBER src stun timeout %u %u\n", src->jabber_stun_or_ft_ts,
packet->tick_timestamp);
src->jabber_file_transfer_port[0] = 0;
src->jabber_file_transfer_port[1] = 0;
} else if (src->jabber_file_transfer_port[0] == packet->tcp->dest
|| src->jabber_file_transfer_port[0] == packet->tcp->source
|| src->jabber_file_transfer_port[1] == packet->tcp->dest
|| src->jabber_file_transfer_port[1] == packet->tcp->source) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"found jabber file transfer.\n");
ndpi_int_jabber_add_connection(ndpi_struct, flow,
NDPI_PROTOCOL_UNENCRYPED_JABBER);
}
}
if (dst != NULL && dst->jabber_file_transfer_port[0] != 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"dst jabber ft port set, ports are: %u, %u\n", ntohs(dst->jabber_file_transfer_port[0]),
ntohs(dst->jabber_file_transfer_port[1]));
if (((u_int32_t)
(packet->tick_timestamp - dst->jabber_stun_or_ft_ts)) >= ndpi_struct->jabber_file_transfer_timeout) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "JABBER dst stun timeout %u %u\n", dst->jabber_stun_or_ft_ts,
packet->tick_timestamp);
dst->jabber_file_transfer_port[0] = 0;
dst->jabber_file_transfer_port[1] = 0;
} else if (dst->jabber_file_transfer_port[0] == packet->tcp->dest
|| dst->jabber_file_transfer_port[0] == packet->tcp->source
|| dst->jabber_file_transfer_port[1] == packet->tcp->dest
|| dst->jabber_file_transfer_port[1] == packet->tcp->source) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"found jabber file transfer.\n");
ndpi_int_jabber_add_connection(ndpi_struct, flow,
NDPI_PROTOCOL_UNENCRYPED_JABBER);
}
}
return;
}
if (packet->tcp != 0 && packet->payload_packet_len == 0) {
return;
}
/* this part parses a packet and searches for port=. it works asymmetrically. */
if (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_UNENCRYPED_JABBER) {
u_int16_t lastlen;
u_int16_t j_port = 0;
/* check for google jabber voip connections ... */
/* need big packet */
if (packet->payload_packet_len < 100) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "packet too small, return.\n");
return;
}
/* need message to or type for file-transfer */
if (memcmp(packet->payload, "<iq from=\"", 8) == 0 || memcmp(packet->payload, "<iq from=\'", 8) == 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "JABBER <iq from=\".\n");
lastlen = packet->payload_packet_len - 11;
for (x = 10; x < lastlen; x++) {
if (packet->payload[x] == 'p') {
if (memcmp(&packet->payload[x], "port=", 5) == 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "port=\n");
if (src != NULL) {
src->jabber_stun_or_ft_ts = packet->tick_timestamp;
}
if (dst != NULL) {
dst->jabber_stun_or_ft_ts = packet->tick_timestamp;
}
x += 6;
j_port = ntohs_ndpi_bytestream_to_number(&packet->payload[x], packet->payload_packet_len, &x);
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "JABBER port : %u\n", ntohs(j_port));
if (src != NULL) {
if (src->jabber_file_transfer_port[0] == 0 || src->jabber_file_transfer_port[0] == j_port) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "src->jabber_file_transfer_port[0] = j_port = %u;\n",
ntohs(j_port));
src->jabber_file_transfer_port[0] = j_port;
} else {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "src->jabber_file_transfer_port[1] = j_port = %u;\n",
ntohs(j_port));
src->jabber_file_transfer_port[1] = j_port;
}
}
if (dst != NULL) {
if (dst->jabber_file_transfer_port[0] == 0 || dst->jabber_file_transfer_port[0] == j_port) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "dst->jabber_file_transfer_port[0] = j_port = %u;\n",
ntohs(j_port));
dst->jabber_file_transfer_port[0] = j_port;
} else {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "dst->jabber_file_transfer_port[1] = j_port = %u;\n",
ntohs(j_port));
dst->jabber_file_transfer_port[1] = j_port;
}
}
}
}
}
} else if (memcmp(packet->payload, "<iq to=\"", 8) == 0 || memcmp(packet->payload, "<iq to=\'", 8) == 0
|| memcmp(packet->payload, "<iq type=", 9) == 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "JABBER <iq to=\"/type=\"\n");
lastlen = packet->payload_packet_len - 21;
for (x = 8; x < lastlen; x++) {
/* invalid character */
if (packet->payload[x] < 32 || packet->payload[x] > 127) {
return;
}
if (packet->payload[x] == '@') {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "JABBER @\n");
break;
}
}
if (x >= lastlen) {
return;
}
lastlen = packet->payload_packet_len - 10;
for (; x < lastlen; x++) {
if (packet->payload[x] == 'p') {
if (memcmp(&packet->payload[x], "port=", 5) == 0) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG, "port=\n");
if (src != NULL) {
src->jabber_stun_or_ft_ts = packet->tick_timestamp;
}
if (dst != NULL) {
dst->jabber_stun_or_ft_ts = packet->tick_timestamp;
}
x += 6;
j_port = ntohs_ndpi_bytestream_to_number(&packet->payload[x], packet->payload_packet_len, &x);
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "JABBER port : %u\n", ntohs(j_port));
if (src != NULL && src->jabber_voice_stun_used_ports < JABBER_MAX_STUN_PORTS - 1) {
if (packet->payload[5] == 'o') {
src->jabber_voice_stun_port[src->jabber_voice_stun_used_ports++]
= j_port;
} else {
if (src->jabber_file_transfer_port[0] == 0
|| src->jabber_file_transfer_port[0] == j_port) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"src->jabber_file_transfer_port[0] = j_port = %u;\n", ntohs(j_port));
src->jabber_file_transfer_port[0] = j_port;
} else {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "src->jabber_file_transfer_port[1] = j_port = %u;\n",
ntohs(j_port));
src->jabber_file_transfer_port[1] = j_port;
}
}
}
if (dst != NULL && dst->jabber_voice_stun_used_ports < JABBER_MAX_STUN_PORTS - 1) {
if (packet->payload[5] == 'o') {
dst->jabber_voice_stun_port[dst->jabber_voice_stun_used_ports++]
= j_port;
} else {
if (dst->jabber_file_transfer_port[0] == 0
|| dst->jabber_file_transfer_port[0] == j_port) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_DEBUG,
"dst->jabber_file_transfer_port[0] = j_port = %u;\n", ntohs(j_port));
dst->jabber_file_transfer_port[0] = j_port;
} else {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "dst->jabber_file_transfer_port[1] = j_port = %u;\n",
ntohs(j_port));
dst->jabber_file_transfer_port[1] = j_port;
}
}
}
return;
}
}
}
}
return;
}
/* search for jabber here */
/* this part is working asymmetrically */
if ((packet->payload_packet_len > 13 && memcmp(packet->payload, "<?xml version=", 14) == 0)
|| (packet->payload_packet_len >= NDPI_STATICSTRING_LEN("<stream:stream ")
&& memcmp(packet->payload, "<stream:stream ", NDPI_STATICSTRING_LEN("<stream:stream ")) == 0)) {
int start = packet->payload_packet_len-13;
if(ndpi_strnstr((const char *)&packet->payload[13], "xmlns:stream='http://etherx.jabber.org/streams'", start)
|| ndpi_strnstr((const char *)&packet->payload[13], "xmlns:stream=\"http://etherx.jabber.org/streams\"", start)) {
/* Protocol family */
ndpi_int_jabber_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_UNENCRYPED_JABBER);
/* search for subprotocols */
check_content_type_and_change_protocol(ndpi_struct, flow, 13);
return;
}
}
if (flow->packet_counter < 3) {
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct,
NDPI_LOG_DEBUG, "packet_counter: %u\n", flow->packet_counter);
return;
}
NDPI_LOG(NDPI_PROTOCOL_UNENCRYPED_JABBER, ndpi_struct, NDPI_LOG_TRACE, "JABBER Excluded.\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_UNENCRYPED_JABBER);
#ifdef NDPI_PROTOCOL_TRUPHONE
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_TRUPHONE);
#endif
}
void ndpi_search_bittorrent(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
/* This is broadcast */
if(packet->iph
&& ((packet->iph->saddr == 0xFFFFFFFF) || (packet->iph->daddr == 0xFFFFFFFF)))
return;
if (packet->detected_protocol_stack[0] != NDPI_PROTOCOL_BITTORRENT) {
/* check for tcp retransmission here */
if ((packet->tcp != NULL)
&& (packet->tcp_retransmission == 0 || packet->num_retried_bytes)) {
ndpi_int_search_bittorrent_tcp(ndpi_struct, flow);
}
else if(packet->udp != NULL) {
char *bt_search = "BT-SEARCH * HTTP/1.1\r\n";
if((ntohs(packet->udp->source) < 1024)
|| (ntohs(packet->udp->dest) < 1024) /* High ports only */)
return;
/*
Check for uTP http://www.bittorrent.org/beps/bep_0029.html
wireshark/epan/dissectors/packet-bt-utp.c
*/
if(packet->payload_packet_len >= 23 /* min header size */) {
if(strncmp((const char*)packet->payload, bt_search, strlen(bt_search)) == 0) {
ndpi_add_connection_as_bittorrent(ndpi_struct, flow,
NDPI_PROTOCOL_SAFE_DETECTION, NDPI_PROTOCOL_PLAIN_DETECTION,
NDPI_REAL_PROTOCOL);
return;
} else {
/* Check if this is protocol v0 */
u_int8_t v0_extension = packet->payload[17];
u_int8_t v0_flags = packet->payload[18];
/* Check if this is protocol v1 */
u_int8_t v1_version = packet->payload[0];
u_int8_t v1_extension = packet->payload[1];
u_int32_t v1_window_size = *((u_int32_t*)&packet->payload[12]);
if((packet->payload[0]== 0x60)
&& (packet->payload[1]== 0x0)
&& (packet->payload[2]== 0x0)
&& (packet->payload[3]== 0x0)
&& (packet->payload[4]== 0x0)) {
/* Heuristic */
goto bittorrent_found;
} else if(((v1_version & 0x0f) == 1)
&& ((v1_version >> 4) < 5 /* ST_NUM_STATES */)
&& (v1_extension < 3 /* EXT_NUM_EXT */)
&& (v1_window_size < 32768 /* 32k */)
) {
goto bittorrent_found;
} else if((v0_flags < 6 /* ST_NUM_STATES */)
&& (v0_extension < 3 /* EXT_NUM_EXT */)) {
u_int32_t ts = ntohl(*((u_int32_t*)&(packet->payload[4])));
u_int32_t now;
#ifndef __KERNEL__
now = (u_int32_t)time(NULL);
#else
struct timespec t;
getnstimeofday(&t);
now = t.tv_sec;
#endif
if((ts < (now+86400)) && (ts > (now-86400))) {
goto bittorrent_found;
}
}
}
}
flow->bittorrent_stage++;
if(flow->bittorrent_stage < 10) {
if(packet->payload_packet_len > 19 /* min size */) {
if(ndpi_strnstr((const char *)packet->payload, ":target20:", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, ":find_node1:", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, "d1:ad2:id20:", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, ":info_hash20:", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, ":filter64", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, "d1:rd2:id20:", packet->payload_packet_len)
|| ndpi_strnstr((const char *)packet->payload, "BitTorrent protocol", packet->payload_packet_len)
) {
bittorrent_found:
NDPI_LOG(NDPI_PROTOCOL_BITTORRENT,
ndpi_struct, NDPI_LOG_TRACE, "BT: plain BitTorrent protocol detected\n");
ndpi_add_connection_as_bittorrent(ndpi_struct, flow,
NDPI_PROTOCOL_SAFE_DETECTION, NDPI_PROTOCOL_PLAIN_DETECTION,
NDPI_REAL_PROTOCOL);
return;
}
}
return;
}
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_BITTORRENT);
}
void ndpi_search_bittorrent(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
/* This is broadcast */
if(packet->iph
&& ((packet->iph->saddr == 0xFFFFFFFF) || (packet->iph->daddr == 0xFFFFFFFF)))
return;
if (packet->detected_protocol_stack[0] != NDPI_PROTOCOL_BITTORRENT) {
/* check for tcp retransmission here */
if ((packet->tcp != NULL)
&& (packet->tcp_retransmission == 0 || packet->num_retried_bytes)) {
ndpi_int_search_bittorrent_tcp(ndpi_struct, flow);
}
else if(packet->udp != NULL) {
/*
Check for uTP http://www.bittorrent.org/beps/bep_0029.html
wireshark/epan/dissectors/packet-bt-utp.c
*/
if(packet->payload_packet_len >= 23 /* min header size */) {
/* Check if this is protocol v0 */
u_int8_t v0_extension = packet->payload[17];
u_int8_t v0_flags = packet->payload[18];
/* Check if this is protocol v1 */
u_int8_t v1_version = packet->payload[0];
u_int8_t v1_extension = packet->payload[1];
if(((v1_version & 0x0f) == 1)
&& ((v1_version >> 4) < 6 /* ST_NUM_STATES */)
&& (v1_extension < 3 /* EXT_NUM_EXT */)) {
goto bittorrent_found;
} else if((v0_flags < 6 /* ST_NUM_STATES */)
&& (v0_extension < 3 /* EXT_NUM_EXT */)) {
u_int32_t ts,
// ts_usec,
now = (u_int32_t)time(NULL);
ts = ntohl(*((u_int32_t*)&(packet->payload[4])));
// ts_usec = ntohl(*((u_int32_t*)&(packet->payload[8])));
if((ts < (now+86400)) && (ts > (now-86400))) {
goto bittorrent_found;
}
}
}
flow->bittorrent_stage++;
if(flow->bittorrent_stage < 10) {
if(packet->payload_packet_len > 19 /* min size */) {
char *begin;
if(ndpi_strnstr(packet->payload, ":target20:", packet->payload_packet_len)
|| ndpi_strnstr(packet->payload, ":find_node1:", packet->payload_packet_len)
|| ndpi_strnstr(packet->payload, "d1:ad2:id20:", packet->payload_packet_len)) {
bittorrent_found:
NDPI_LOG_BITTORRENT(NDPI_PROTOCOL_BITTORRENT,
ndpi_struct, NDPI_LOG_TRACE, "BT: plain BitTorrent protocol detected\n");
ndpi_add_connection_as_bittorrent(ndpi_struct, flow,
NDPI_PROTOCOL_SAFE_DETECTION, NDPI_PROTOCOL_PLAIN_DETECTION,
NDPI_REAL_PROTOCOL);
return;
} else if((begin = memchr(packet->payload, 'B', packet->payload_packet_len-19)) != NULL) {
long offset = (u_long)begin - (u_long)packet->payload;
if((packet->payload_packet_len-19) > offset) {
if(memcmp(begin, "BitTorrent protocol", 19) == 0) {
goto bittorrent_found;
}
}
}
}
return;
}
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_BITTORRENT);
}