/src/ndpi/src/lib/protocols/melsec.c
Line | Count | Source |
1 | | /* |
2 | | * melsec.c |
3 | | * |
4 | | * MELSEC Communication Protocol |
5 | | * |
6 | | * Copyright (C) 2025 - ntop.org |
7 | | * Copyright (C) 2025 - V.G <v.gavrilov@securitycode.ru> |
8 | | * |
9 | | * This file is part of nDPI, an open source deep packet inspection |
10 | | * library based on the OpenDPI and PACE technology by ipoque GmbH |
11 | | * |
12 | | * nDPI is free software: you can redistribute it and/or modify |
13 | | * it under the terms of the GNU Lesser General Public License as published by |
14 | | * the Free Software Foundation, either version 3 of the License, or |
15 | | * (at your option) any later version. |
16 | | * |
17 | | * nDPI is distributed in the hope that it will be useful, |
18 | | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | | * GNU Lesser General Public License for more details. |
21 | | * |
22 | | * You should have received a copy of the GNU Lesser General Public License |
23 | | * along with nDPI. If not, see <http://www.gnu.org/licenses/>. |
24 | | * |
25 | | */ |
26 | | |
27 | | #include "ndpi_protocol_ids.h" |
28 | | |
29 | | #define NDPI_CURRENT_PROTO NDPI_PROTOCOL_MELSEC |
30 | | |
31 | | #include "ndpi_api.h" |
32 | | #include "ndpi_private.h" |
33 | | |
34 | | static void ndpi_search_melsec(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow) |
35 | 3.83M | { |
36 | 3.83M | struct ndpi_packet_struct const * const packet = &ndpi_struct->packet; |
37 | | |
38 | 3.83M | NDPI_LOG_DBG(ndpi_struct, "search MELSEC\n"); |
39 | | |
40 | 3.83M | if (packet->payload_packet_len > 40 && |
41 | 2.07M | (packet->payload[0] == 0x57 || packet->payload[0] == 0xD7)) |
42 | 7.52k | { |
43 | 7.52k | u_int16_t melsec_payload_len = packet->payload_packet_len - 21; |
44 | 7.52k | if (le16toh(get_u_int16_t(packet->payload, 19)) == melsec_payload_len && |
45 | 7.52k | ntohl(get_u_int32_t(packet->payload, 3)) == 0x00001111) |
46 | 88 | { |
47 | 88 | NDPI_LOG_INFO(ndpi_struct, "found MELSEC\n"); |
48 | 88 | ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_MELSEC, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI); |
49 | 88 | } |
50 | 7.52k | } |
51 | | |
52 | 3.83M | if (flow->packet_counter > 2) { |
53 | 373k | NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow); |
54 | 373k | } |
55 | 3.83M | } |
56 | | |
57 | | void init_melsec_dissector(struct ndpi_detection_module_struct *ndpi_struct) |
58 | 12.3k | { |
59 | 12.3k | register_dissector("MELSEC", ndpi_struct, |
60 | 12.3k | ndpi_search_melsec, |
61 | 12.3k | NDPI_SELECTION_BITMASK_PROTOCOL_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION, |
62 | 12.3k | 1, NDPI_PROTOCOL_MELSEC); |
63 | 12.3k | } |