/src/ndpi/src/lib/protocols/raknet.c
Line | Count | Source |
1 | | /* |
2 | | * raknet.c |
3 | | * |
4 | | * Copyright (C) 2011-25 - ntop.org |
5 | | * |
6 | | * nDPI is free software: you can redistribute it and/or modify |
7 | | * it under the terms of the GNU Lesser General Public License as published by |
8 | | * the Free Software Foundation, either version 3 of the License, or |
9 | | * (at your option) any later version. |
10 | | * |
11 | | * nDPI is distributed in the hope that it will be useful, |
12 | | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | | * GNU Lesser General Public License for more details. |
15 | | * |
16 | | * You should have received a copy of the GNU Lesser General Public License |
17 | | * along with nDPI. If not, see <http://www.gnu.org/licenses/>. |
18 | | * |
19 | | */ |
20 | | |
21 | | #include "ndpi_protocol_ids.h" |
22 | | |
23 | | #define NDPI_CURRENT_PROTO NDPI_PROTOCOL_RAKNET |
24 | | |
25 | | #include "ndpi_api.h" |
26 | | #include "ndpi_private.h" |
27 | | |
28 | | static void ndpi_int_raknet_add_connection(struct ndpi_detection_module_struct * const ndpi_struct, |
29 | | struct ndpi_flow_struct * const flow) |
30 | 0 | { |
31 | 0 | NDPI_LOG_INFO(ndpi_struct, "found RakNet\n"); |
32 | 0 | ndpi_set_detected_protocol(ndpi_struct, flow, |
33 | 0 | NDPI_PROTOCOL_RAKNET, |
34 | 0 | NDPI_PROTOCOL_UNKNOWN, |
35 | 0 | NDPI_CONFIDENCE_DPI); |
36 | 0 | } |
37 | | |
38 | | static size_t raknet_dissect_ip(struct ndpi_packet_struct * const packet, size_t offset) |
39 | 0 | { |
40 | 0 | if (offset + 1 >= packet->payload_packet_len || |
41 | 0 | (packet->payload[offset] != 0x04 /* IPv4 */ && |
42 | 0 | packet->payload[offset] != 0x06 /* IPv6 */)) |
43 | 0 | { |
44 | 0 | return 0; |
45 | 0 | } |
46 | | |
47 | 0 | return (packet->payload[offset] == 0x04 ? 4 : 16); |
48 | 0 | } |
49 | | |
50 | | static int is_custom_version(struct ndpi_detection_module_struct *ndpi_struct) |
51 | 0 | { |
52 | 0 | struct ndpi_packet_struct *packet = &ndpi_struct->packet; |
53 | 0 | unsigned char magic[] = { 0x00, 0xFF, 0xFF, 0x00, 0xFE, 0xFE, 0xFE, 0xFE, |
54 | 0 | 0xFD, 0xFD, 0xFD, 0xFD, 0x12, 0x34, 0x56, 0x78 }; |
55 | |
|
56 | 0 | if (packet->payload_packet_len >= 1200) /* Full MTU packet */ |
57 | 0 | { |
58 | | /* Offset 32 has been found only in the traces; the other ones are present |
59 | | also in the Raknet heuristic in Wireshark */ |
60 | 0 | if (memcmp(magic, &packet->payload[1], sizeof(magic)) == 0 || |
61 | 0 | memcmp(magic, &packet->payload[9], sizeof(magic)) == 0 || |
62 | 0 | memcmp(magic, &packet->payload[17], sizeof(magic)) == 0 || |
63 | 0 | memcmp(magic, &packet->payload[32], sizeof(magic)) == 0) |
64 | 0 | { |
65 | 0 | return 1; |
66 | 0 | } |
67 | 0 | } |
68 | 0 | return 0; |
69 | 0 | } |
70 | | |
71 | | static void exclude_proto(struct ndpi_detection_module_struct *ndpi_struct, |
72 | | struct ndpi_flow_struct *flow) |
73 | 0 | { |
74 | 0 | if (flow->l4.udp.raknet_custom == 1) |
75 | 0 | { |
76 | 0 | NDPI_LOG_INFO(ndpi_struct, "found RakNet (custom version)\n"); |
77 | | /* Classify as Raknet or as Roblox? |
78 | | This pattern ha been observed with Roblox games but it might be used by |
79 | | other protocols too. Keep the generic classification, for the time being */ |
80 | 0 | ndpi_int_raknet_add_connection(ndpi_struct, flow); |
81 | 0 | } else { |
82 | 0 | NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow); |
83 | 0 | } |
84 | 0 | } |
85 | | |
86 | | /* Reference: https://wiki.vg/Raknet_Protocol */ |
87 | | static void ndpi_search_raknet(struct ndpi_detection_module_struct *ndpi_struct, |
88 | | struct ndpi_flow_struct *flow) |
89 | 0 | { |
90 | 0 | struct ndpi_packet_struct * const packet = &ndpi_struct->packet; |
91 | 0 | u_int8_t op, ip_addr_offset, required_packets = 3; |
92 | |
|
93 | 0 | NDPI_LOG_DBG(ndpi_struct, "search RakNet\n"); |
94 | | |
95 | | /* There are two "versions" of Raknet: |
96 | | * plaintext one: we need multiple packets for classification and for extracting metadata |
97 | | * custom/encrypted one: an extension used by Roblox games (and others?). |
98 | | Only the first pkt is required. |
99 | | The main issue is that these two versions "overlap", i.e. some plaintext flows might be wrongly |
100 | | identified as encrypted one (losing their metadata). |
101 | | Solution: check for the custoom/encrypted version, cache the result and use it only if/when the |
102 | | standard detection ends. |
103 | | */ |
104 | 0 | if (flow->packet_counter == 1) |
105 | 0 | { |
106 | 0 | flow->l4.udp.raknet_custom = is_custom_version(ndpi_struct); |
107 | 0 | } |
108 | |
|
109 | 0 | if (packet->payload_packet_len < 7) |
110 | 0 | { |
111 | 0 | exclude_proto(ndpi_struct, flow); |
112 | 0 | return; |
113 | 0 | } |
114 | | |
115 | 0 | op = packet->payload[0]; |
116 | |
|
117 | 0 | switch (op) |
118 | 0 | { |
119 | 0 | case 0x00: /* Connected Ping */ |
120 | 0 | if (packet->payload_packet_len != 8) |
121 | 0 | { |
122 | 0 | exclude_proto(ndpi_struct, flow); |
123 | 0 | return; |
124 | 0 | } |
125 | 0 | required_packets = 6; |
126 | 0 | break; |
127 | | |
128 | 0 | case 0x01: /* Unconnected Ping */ |
129 | 0 | case 0x02: /* Unconnected Ping */ |
130 | 0 | if (packet->payload_packet_len != 32) |
131 | 0 | { |
132 | 0 | exclude_proto(ndpi_struct, flow); |
133 | 0 | return; |
134 | 0 | } |
135 | 0 | required_packets = 6; |
136 | 0 | break; |
137 | | |
138 | 0 | case 0x03: /* Connected Pong */ |
139 | 0 | if (packet->payload_packet_len != 16) |
140 | 0 | { |
141 | 0 | exclude_proto(ndpi_struct, flow); |
142 | 0 | return; |
143 | 0 | } |
144 | 0 | required_packets = 6; |
145 | 0 | break; |
146 | | |
147 | 0 | case 0x05: /* Open Connection Request 1 */ |
148 | 0 | if (packet->payload_packet_len < 18 || |
149 | 0 | packet->payload[17] > 10 /* maximum supported protocol version */) |
150 | 0 | { |
151 | 0 | exclude_proto(ndpi_struct, flow); |
152 | 0 | return; |
153 | 0 | } |
154 | 0 | required_packets = 6; |
155 | 0 | break; |
156 | | |
157 | 0 | case 0x06: /* Open Connection Reply 1 */ |
158 | 0 | if (packet->payload_packet_len != 28 || |
159 | 0 | packet->payload[25] > 0x01 /* connection uses encryption: bool -> 0x00 or 0x01 */) |
160 | 0 | { |
161 | 0 | exclude_proto(ndpi_struct, flow); |
162 | 0 | return; |
163 | 0 | } |
164 | | |
165 | 0 | { |
166 | 0 | u_int16_t mtu_size = ntohs(get_u_int16_t(packet->payload, 26)); |
167 | 0 | if (mtu_size > 1500 /* Max. supported MTU, see: http://www.jenkinssoftware.com/raknet/manual/programmingtips.html */) |
168 | 0 | { |
169 | 0 | exclude_proto(ndpi_struct, flow); |
170 | 0 | return; |
171 | 0 | } |
172 | 0 | } |
173 | 0 | required_packets = 4; |
174 | 0 | break; |
175 | | |
176 | 0 | case 0x07: /* Open Connection Request 2 */ |
177 | 0 | ip_addr_offset = raknet_dissect_ip(packet, 17); |
178 | 0 | if (ip_addr_offset == 0 || |
179 | 0 | !((ip_addr_offset == 16 && packet->payload_packet_len == 46) || |
180 | 0 | (ip_addr_offset == 4 && packet->payload_packet_len == 34))) |
181 | 0 | { |
182 | 0 | exclude_proto(ndpi_struct, flow); |
183 | 0 | return; |
184 | 0 | } |
185 | | |
186 | 0 | { |
187 | 0 | u_int16_t mtu_size = ntohs(get_u_int16_t(packet->payload, 20 + ip_addr_offset)); |
188 | 0 | if (mtu_size > 1500 /* Max. supported MTU, see: http://www.jenkinssoftware.com/raknet/manual/programmingtips.html */) |
189 | 0 | { |
190 | 0 | exclude_proto(ndpi_struct, flow); |
191 | 0 | return; |
192 | 0 | } |
193 | 0 | } |
194 | 0 | break; |
195 | | |
196 | 0 | case 0x08: /* Open Connection Reply 2 */ |
197 | 0 | ip_addr_offset = raknet_dissect_ip(packet, 25); |
198 | 0 | if (ip_addr_offset == 0 || |
199 | 0 | !((ip_addr_offset == 16 && packet->payload_packet_len == 47) || |
200 | 0 | (ip_addr_offset == 4 && packet->payload_packet_len == 35))) |
201 | 0 | { |
202 | 0 | exclude_proto(ndpi_struct, flow); |
203 | 0 | return; |
204 | 0 | } |
205 | | |
206 | 0 | { |
207 | 0 | u_int16_t mtu_size = ntohs(get_u_int16_t(packet->payload, 28 + ip_addr_offset)); |
208 | 0 | if (mtu_size > 1500 /* Max. supported MTU, see: http://www.jenkinssoftware.com/raknet/manual/programmingtips.html */) |
209 | 0 | { |
210 | 0 | exclude_proto(ndpi_struct, flow); |
211 | 0 | return; |
212 | 0 | } |
213 | 0 | } |
214 | 0 | break; |
215 | | |
216 | 0 | case 0x10: /* Connection Request Accepted */ |
217 | 0 | case 0x13: /* New Incoming Connection */ |
218 | 0 | { |
219 | 0 | size_t i; |
220 | |
|
221 | 0 | ip_addr_offset = 4 + raknet_dissect_ip(packet, 0); |
222 | 0 | if (op == 0x10) |
223 | 0 | { |
224 | 0 | ip_addr_offset += 2; // System Index |
225 | 0 | } |
226 | 0 | for (i = 0; i < 10; ++i) |
227 | 0 | { |
228 | 0 | ip_addr_offset += 3 + raknet_dissect_ip(packet, ip_addr_offset); |
229 | 0 | } |
230 | 0 | ip_addr_offset += 16; |
231 | 0 | if (ip_addr_offset != packet->payload_packet_len) |
232 | 0 | { |
233 | 0 | exclude_proto(ndpi_struct, flow); |
234 | 0 | return; |
235 | 0 | } |
236 | 0 | } |
237 | 0 | break; |
238 | | |
239 | | /* Check for Frame Set Packet's */ |
240 | 0 | case 0x80: |
241 | 0 | case 0x81: |
242 | 0 | case 0x82: |
243 | 0 | case 0x83: |
244 | 0 | case 0x84: |
245 | 0 | case 0x85: |
246 | 0 | case 0x86: |
247 | 0 | case 0x87: |
248 | 0 | case 0x88: |
249 | 0 | case 0x89: |
250 | 0 | case 0x8a: |
251 | 0 | case 0x8b: |
252 | 0 | case 0x8c: |
253 | 0 | case 0x8d: |
254 | 0 | { |
255 | 0 | size_t frame_offset = 4; |
256 | |
|
257 | 0 | do { |
258 | 0 | u_int8_t msg_flags = get_u_int8_t(packet->payload, frame_offset); |
259 | 0 | if ((msg_flags & 0x0F) != 0) |
260 | 0 | { |
261 | 0 | exclude_proto(ndpi_struct, flow); |
262 | 0 | return; |
263 | 0 | } |
264 | | |
265 | 0 | u_int16_t msg_size = ntohs(get_u_int16_t(packet->payload, frame_offset + 1)); |
266 | 0 | msg_size /= 8; |
267 | 0 | if (msg_size == 0) |
268 | 0 | { |
269 | 0 | exclude_proto(ndpi_struct, flow); |
270 | 0 | break; |
271 | 0 | } |
272 | | |
273 | 0 | u_int8_t reliability_type = (msg_flags & 0xE0) >> 5; |
274 | 0 | if (reliability_type >= 2 && reliability_type <= 4 /* is reliable? */) |
275 | 0 | { |
276 | 0 | frame_offset += 3; |
277 | 0 | } |
278 | 0 | if (reliability_type == 1 || reliability_type == 4 /* is sequenced? */) |
279 | 0 | { |
280 | 0 | frame_offset += 3; |
281 | 0 | } |
282 | 0 | if (reliability_type == 3 || reliability_type == 7 /* is ordered? */) |
283 | 0 | { |
284 | 0 | frame_offset += 4; |
285 | 0 | } |
286 | 0 | if ((msg_flags & 0x10) != 0 /* is fragmented? */) |
287 | 0 | { |
288 | 0 | frame_offset += 10; |
289 | 0 | } |
290 | |
|
291 | 0 | frame_offset += msg_size + 3; |
292 | 0 | } while (frame_offset + 3 <= packet->payload_packet_len); |
293 | | |
294 | | /* We've dissected enough to be sure. */ |
295 | 0 | if (frame_offset == packet->payload_packet_len) |
296 | 0 | { |
297 | | /* This packet might also be a RTP/RTCP one: give precedence to RTP/RTCP dissector */ |
298 | 0 | if(flow->rtp_stage == 0 && flow->rtcp_stage == 0) |
299 | 0 | ndpi_int_raknet_add_connection(ndpi_struct, flow); |
300 | 0 | } else { |
301 | 0 | exclude_proto(ndpi_struct, flow); |
302 | 0 | } |
303 | 0 | return; |
304 | 0 | } |
305 | | |
306 | 0 | case 0x09: /* Connection Request */ |
307 | 0 | if (packet->payload_packet_len != 16) |
308 | 0 | { |
309 | 0 | exclude_proto(ndpi_struct, flow); |
310 | 0 | return; |
311 | 0 | } |
312 | 0 | required_packets = 6; |
313 | 0 | break; |
314 | | |
315 | 0 | case 0x15: /* Disconnect */ |
316 | 0 | required_packets = 8; |
317 | 0 | break; |
318 | | |
319 | 0 | case 0x19: /* Incompatible Protocol */ |
320 | 0 | if (packet->payload_packet_len != 25 || |
321 | 0 | packet->payload[17] > 10) |
322 | 0 | { |
323 | 0 | exclude_proto(ndpi_struct, flow); |
324 | 0 | return; |
325 | 0 | } |
326 | 0 | break; |
327 | | |
328 | 0 | case 0x1c: /* Unconnected Pong */ |
329 | 0 | if (packet->payload_packet_len < 35) |
330 | 0 | { |
331 | 0 | exclude_proto(ndpi_struct, flow); |
332 | 0 | return; |
333 | 0 | } |
334 | | |
335 | 0 | { |
336 | 0 | u_int16_t motd_len = ntohs(get_u_int16_t(packet->payload, 33)); |
337 | |
|
338 | 0 | if (motd_len == 0 || motd_len + 35 != packet->payload_packet_len) |
339 | 0 | { |
340 | 0 | exclude_proto(ndpi_struct, flow); |
341 | 0 | return; |
342 | 0 | } |
343 | 0 | } |
344 | 0 | break; |
345 | | |
346 | 0 | case 0xa0: /* NACK */ |
347 | 0 | case 0xc0: /* ACK */ |
348 | 0 | { |
349 | 0 | u_int16_t record_count = ntohs(get_u_int16_t(packet->payload, 1)); |
350 | 0 | size_t record_index = 0, record_offset = 3; |
351 | |
|
352 | 0 | do { |
353 | 0 | if (packet->payload[record_offset] == 0x00 /* Range */) |
354 | 0 | { |
355 | 0 | record_offset += 7; |
356 | 0 | } else if (packet->payload[record_offset] == 0x01 /* No Range */) |
357 | 0 | { |
358 | 0 | record_offset += 4; |
359 | 0 | } else { |
360 | 0 | exclude_proto(ndpi_struct, flow); |
361 | 0 | return; |
362 | 0 | } |
363 | 0 | } while (++record_index < record_count && |
364 | 0 | record_offset + 4 <= packet->payload_packet_len); |
365 | | |
366 | 0 | if (record_index == record_count && record_offset == packet->payload_packet_len) |
367 | 0 | { |
368 | | /* This packet might also be a RTP/RTCP one: give precedence to RTP/RTCP dissector */ |
369 | 0 | if(flow->rtp_stage == 0 && flow->rtcp_stage == 0) |
370 | 0 | ndpi_int_raknet_add_connection(ndpi_struct, flow); |
371 | 0 | } else { |
372 | 0 | exclude_proto(ndpi_struct, flow); |
373 | 0 | } |
374 | 0 | return; |
375 | 0 | } |
376 | | |
377 | 0 | case 0xfe: /* Game Packet */ |
378 | 0 | required_packets = 8; |
379 | 0 | break; |
380 | | |
381 | 0 | default: /* Invalid RakNet packet */ |
382 | 0 | exclude_proto(ndpi_struct, flow); |
383 | 0 | return; |
384 | 0 | } |
385 | | |
386 | 0 | if (flow->packet_counter < required_packets) |
387 | 0 | { |
388 | 0 | return; |
389 | 0 | } |
390 | | |
391 | 0 | ndpi_int_raknet_add_connection(ndpi_struct, flow); |
392 | 0 | } |
393 | | |
394 | | void init_raknet_dissector(struct ndpi_detection_module_struct *ndpi_struct) |
395 | 0 | { |
396 | 0 | register_dissector("RakNet", ndpi_struct, |
397 | 0 | ndpi_search_raknet, |
398 | 0 | NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD, |
399 | 0 | 1, NDPI_PROTOCOL_RAKNET); |
400 | 0 | } |