1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*
* gtp.c
*
* Copyright (C) 2011-15 - ntop.org
*
* 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_api.h"
#ifdef NDPI_PROTOCOL_GTP
struct gtp_header_generic {
u_int8_t flags, message_type;
u_int16_t message_len;
u_int32_t teid;
};
static void ndpi_check_gtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
// const u_int8_t *packet_payload = packet->payload;
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->udp != NULL) && (payload_len > sizeof(struct gtp_header_generic))) {
u_int32_t gtp_u = ntohs(2152);
u_int32_t gtp_c = ntohs(2123);
u_int32_t gtp_v0 = ntohs(3386);
if((packet->udp->source == gtp_u) || (packet->udp->dest == gtp_u)
|| (packet->udp->source == gtp_c) || (packet->udp->dest == gtp_c)
|| (packet->udp->source == gtp_v0) || (packet->udp->dest == gtp_v0)
) {
struct gtp_header_generic *gtp = (struct gtp_header_generic*)packet->payload;
u_int8_t gtp_version = (gtp->flags & 0xE0) >> 5;
if((gtp_version == 0) || (gtp_version == 1) || (gtp_version == 2)) {
u_int16_t message_len = ntohs(gtp->message_len);
if(message_len <= (payload_len-sizeof(struct gtp_header_generic))) {
NDPI_LOG(NDPI_PROTOCOL_GTP, ndpi_struct, NDPI_LOG_DEBUG, "Found gtp.\n");
ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_GTP, NDPI_PROTOCOL_UNKNOWN);
return;
}
}
}
}
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_GTP);
return;
}
void ndpi_search_gtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
struct ndpi_packet_struct *packet = &flow->packet;
NDPI_LOG(NDPI_PROTOCOL_GTP, ndpi_struct, NDPI_LOG_DEBUG, "gtp detection...\n");
/* skip marked packets */
if(packet->detected_protocol_stack[0] != NDPI_PROTOCOL_GTP)
ndpi_check_gtp(ndpi_struct, flow);
}
#endif
|