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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
2bc78049 PM |
2 | /* |
3 | * DCCP connection tracking protocol helper | |
4 | * | |
5 | * Copyright (c) 2005, 2006, 2008 Patrick McHardy <kaber@trash.net> | |
2bc78049 PM |
6 | */ |
7 | #include <linux/kernel.h> | |
2bc78049 PM |
8 | #include <linux/init.h> |
9 | #include <linux/sysctl.h> | |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/dccp.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
2bc78049 | 14 | |
1546000f CG |
15 | #include <net/net_namespace.h> |
16 | #include <net/netns/generic.h> | |
17 | ||
2bc78049 PM |
18 | #include <linux/netfilter/nfnetlink_conntrack.h> |
19 | #include <net/netfilter/nf_conntrack.h> | |
20 | #include <net/netfilter/nf_conntrack_l4proto.h> | |
b38b1f61 | 21 | #include <net/netfilter/nf_conntrack_ecache.h> |
c779e849 | 22 | #include <net/netfilter/nf_conntrack_timeout.h> |
2bc78049 PM |
23 | #include <net/netfilter/nf_log.h> |
24 | ||
2bc78049 PM |
25 | /* Timeouts are based on values from RFC4340: |
26 | * | |
27 | * - REQUEST: | |
28 | * | |
29 | * 8.1.2. Client Request | |
30 | * | |
31 | * A client MAY give up on its DCCP-Requests after some time | |
32 | * (3 minutes, for example). | |
33 | * | |
34 | * - RESPOND: | |
35 | * | |
36 | * 8.1.3. Server Response | |
37 | * | |
38 | * It MAY also leave the RESPOND state for CLOSED after a timeout of | |
39 | * not less than 4MSL (8 minutes); | |
40 | * | |
41 | * - PARTOPEN: | |
42 | * | |
43 | * 8.1.5. Handshake Completion | |
44 | * | |
45 | * If the client remains in PARTOPEN for more than 4MSL (8 minutes), | |
46 | * it SHOULD reset the connection with Reset Code 2, "Aborted". | |
47 | * | |
48 | * - OPEN: | |
49 | * | |
50 | * The DCCP timestamp overflows after 11.9 hours. If the connection | |
51 | * stays idle this long the sequence number won't be recognized | |
52 | * as valid anymore. | |
53 | * | |
54 | * - CLOSEREQ/CLOSING: | |
55 | * | |
56 | * 8.3. Termination | |
57 | * | |
58 | * The retransmission timer should initially be set to go off in two | |
59 | * round-trip times and should back off to not less than once every | |
60 | * 64 seconds ... | |
61 | * | |
62 | * - TIMEWAIT: | |
63 | * | |
64 | * 4.3. States | |
65 | * | |
66 | * A server or client socket remains in this state for 2MSL (4 minutes) | |
67 | * after the connection has been town down, ... | |
68 | */ | |
69 | ||
70 | #define DCCP_MSL (2 * 60 * HZ) | |
71 | ||
2bc78049 PM |
72 | static const char * const dccp_state_names[] = { |
73 | [CT_DCCP_NONE] = "NONE", | |
74 | [CT_DCCP_REQUEST] = "REQUEST", | |
75 | [CT_DCCP_RESPOND] = "RESPOND", | |
76 | [CT_DCCP_PARTOPEN] = "PARTOPEN", | |
77 | [CT_DCCP_OPEN] = "OPEN", | |
78 | [CT_DCCP_CLOSEREQ] = "CLOSEREQ", | |
79 | [CT_DCCP_CLOSING] = "CLOSING", | |
80 | [CT_DCCP_TIMEWAIT] = "TIMEWAIT", | |
81 | [CT_DCCP_IGNORE] = "IGNORE", | |
82 | [CT_DCCP_INVALID] = "INVALID", | |
83 | }; | |
84 | ||
85 | #define sNO CT_DCCP_NONE | |
86 | #define sRQ CT_DCCP_REQUEST | |
87 | #define sRS CT_DCCP_RESPOND | |
88 | #define sPO CT_DCCP_PARTOPEN | |
89 | #define sOP CT_DCCP_OPEN | |
90 | #define sCR CT_DCCP_CLOSEREQ | |
91 | #define sCG CT_DCCP_CLOSING | |
92 | #define sTW CT_DCCP_TIMEWAIT | |
93 | #define sIG CT_DCCP_IGNORE | |
94 | #define sIV CT_DCCP_INVALID | |
95 | ||
96 | /* | |
25985edc | 97 | * DCCP state transition table |
2bc78049 PM |
98 | * |
99 | * The assumption is the same as for TCP tracking: | |
100 | * | |
101 | * We are the man in the middle. All the packets go through us but might | |
102 | * get lost in transit to the destination. It is assumed that the destination | |
103 | * can't receive segments we haven't seen. | |
104 | * | |
105 | * The following states exist: | |
106 | * | |
107 | * NONE: Initial state, expecting Request | |
108 | * REQUEST: Request seen, waiting for Response from server | |
109 | * RESPOND: Response from server seen, waiting for Ack from client | |
110 | * PARTOPEN: Ack after Response seen, waiting for packet other than Response, | |
111 | * Reset or Sync from server | |
112 | * OPEN: Packet other than Response, Reset or Sync seen | |
113 | * CLOSEREQ: CloseReq from server seen, expecting Close from client | |
114 | * CLOSING: Close seen, expecting Reset | |
115 | * TIMEWAIT: Reset seen | |
116 | * IGNORE: Not determinable whether packet is valid | |
117 | * | |
118 | * Some states exist only on one side of the connection: REQUEST, RESPOND, | |
119 | * PARTOPEN, CLOSEREQ. For the other side these states are equivalent to | |
120 | * the one it was in before. | |
121 | * | |
122 | * Packets are marked as ignored (sIG) if we don't know if they're valid | |
123 | * (for example a reincarnation of a connection we didn't notice is dead | |
124 | * already) and the server may send back a connection closing Reset or a | |
125 | * Response. They're also used for Sync/SyncAck packets, which we don't | |
126 | * care about. | |
127 | */ | |
128 | static const u_int8_t | |
129 | dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] = { | |
130 | [CT_DCCP_ROLE_CLIENT] = { | |
131 | [DCCP_PKT_REQUEST] = { | |
132 | /* | |
133 | * sNO -> sRQ Regular Request | |
134 | * sRQ -> sRQ Retransmitted Request or reincarnation | |
135 | * sRS -> sRS Retransmitted Request (apparently Response | |
136 | * got lost after we saw it) or reincarnation | |
137 | * sPO -> sIG Ignore, conntrack might be out of sync | |
138 | * sOP -> sIG Ignore, conntrack might be out of sync | |
139 | * sCR -> sIG Ignore, conntrack might be out of sync | |
140 | * sCG -> sIG Ignore, conntrack might be out of sync | |
141 | * sTW -> sRQ Reincarnation | |
142 | * | |
143 | * sNO, sRQ, sRS, sPO. sOP, sCR, sCG, sTW, */ | |
144 | sRQ, sRQ, sRS, sIG, sIG, sIG, sIG, sRQ, | |
145 | }, | |
146 | [DCCP_PKT_RESPONSE] = { | |
147 | /* | |
148 | * sNO -> sIV Invalid | |
149 | * sRQ -> sIG Ignore, might be response to ignored Request | |
150 | * sRS -> sIG Ignore, might be response to ignored Request | |
151 | * sPO -> sIG Ignore, might be response to ignored Request | |
152 | * sOP -> sIG Ignore, might be response to ignored Request | |
153 | * sCR -> sIG Ignore, might be response to ignored Request | |
154 | * sCG -> sIG Ignore, might be response to ignored Request | |
155 | * sTW -> sIV Invalid, reincarnation in reverse direction | |
156 | * goes through sRQ | |
157 | * | |
158 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
159 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIV, | |
160 | }, | |
161 | [DCCP_PKT_ACK] = { | |
162 | /* | |
163 | * sNO -> sIV No connection | |
164 | * sRQ -> sIV No connection | |
165 | * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.) | |
166 | * sPO -> sPO Retransmitted Ack for Response, remain in PARTOPEN | |
167 | * sOP -> sOP Regular ACK, remain in OPEN | |
168 | * sCR -> sCR Ack in CLOSEREQ MAY be processed (8.3.) | |
169 | * sCG -> sCG Ack in CLOSING MAY be processed (8.3.) | |
170 | * sTW -> sIV | |
171 | * | |
172 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
173 | sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV | |
174 | }, | |
175 | [DCCP_PKT_DATA] = { | |
176 | /* | |
177 | * sNO -> sIV No connection | |
178 | * sRQ -> sIV No connection | |
179 | * sRS -> sIV No connection | |
180 | * sPO -> sIV MUST use DataAck in PARTOPEN state (8.1.5.) | |
181 | * sOP -> sOP Regular Data packet | |
182 | * sCR -> sCR Data in CLOSEREQ MAY be processed (8.3.) | |
183 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
184 | * sTW -> sIV | |
185 | * | |
186 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
187 | sIV, sIV, sIV, sIV, sOP, sCR, sCG, sIV, | |
188 | }, | |
189 | [DCCP_PKT_DATAACK] = { | |
190 | /* | |
191 | * sNO -> sIV No connection | |
192 | * sRQ -> sIV No connection | |
193 | * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.) | |
194 | * sPO -> sPO Remain in PARTOPEN state | |
195 | * sOP -> sOP Regular DataAck packet in OPEN state | |
196 | * sCR -> sCR DataAck in CLOSEREQ MAY be processed (8.3.) | |
197 | * sCG -> sCG DataAck in CLOSING MAY be processed (8.3.) | |
198 | * sTW -> sIV | |
199 | * | |
200 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
201 | sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV | |
202 | }, | |
203 | [DCCP_PKT_CLOSEREQ] = { | |
204 | /* | |
205 | * CLOSEREQ may only be sent by the server. | |
206 | * | |
207 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
208 | sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV | |
209 | }, | |
210 | [DCCP_PKT_CLOSE] = { | |
211 | /* | |
212 | * sNO -> sIV No connection | |
213 | * sRQ -> sIV No connection | |
214 | * sRS -> sIV No connection | |
215 | * sPO -> sCG Client-initiated close | |
216 | * sOP -> sCG Client-initiated close | |
217 | * sCR -> sCG Close in response to CloseReq (8.3.) | |
218 | * sCG -> sCG Retransmit | |
219 | * sTW -> sIV Late retransmit, already in TIME_WAIT | |
220 | * | |
221 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
222 | sIV, sIV, sIV, sCG, sCG, sCG, sIV, sIV | |
223 | }, | |
224 | [DCCP_PKT_RESET] = { | |
225 | /* | |
226 | * sNO -> sIV No connection | |
227 | * sRQ -> sTW Sync received or timeout, SHOULD send Reset (8.1.1.) | |
228 | * sRS -> sTW Response received without Request | |
229 | * sPO -> sTW Timeout, SHOULD send Reset (8.1.5.) | |
230 | * sOP -> sTW Connection reset | |
231 | * sCR -> sTW Connection reset | |
232 | * sCG -> sTW Connection reset | |
233 | * sTW -> sIG Ignore (don't refresh timer) | |
234 | * | |
235 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
236 | sIV, sTW, sTW, sTW, sTW, sTW, sTW, sIG | |
237 | }, | |
238 | [DCCP_PKT_SYNC] = { | |
239 | /* | |
240 | * We currently ignore Sync packets | |
241 | * | |
242 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 243 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
244 | }, |
245 | [DCCP_PKT_SYNCACK] = { | |
246 | /* | |
247 | * We currently ignore SyncAck packets | |
248 | * | |
249 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 250 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
251 | }, |
252 | }, | |
253 | [CT_DCCP_ROLE_SERVER] = { | |
254 | [DCCP_PKT_REQUEST] = { | |
255 | /* | |
256 | * sNO -> sIV Invalid | |
257 | * sRQ -> sIG Ignore, conntrack might be out of sync | |
258 | * sRS -> sIG Ignore, conntrack might be out of sync | |
259 | * sPO -> sIG Ignore, conntrack might be out of sync | |
260 | * sOP -> sIG Ignore, conntrack might be out of sync | |
261 | * sCR -> sIG Ignore, conntrack might be out of sync | |
262 | * sCG -> sIG Ignore, conntrack might be out of sync | |
263 | * sTW -> sRQ Reincarnation, must reverse roles | |
264 | * | |
265 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
266 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sRQ | |
267 | }, | |
268 | [DCCP_PKT_RESPONSE] = { | |
269 | /* | |
270 | * sNO -> sIV Response without Request | |
271 | * sRQ -> sRS Response to clients Request | |
272 | * sRS -> sRS Retransmitted Response (8.1.3. SHOULD NOT) | |
273 | * sPO -> sIG Response to an ignored Request or late retransmit | |
274 | * sOP -> sIG Ignore, might be response to ignored Request | |
275 | * sCR -> sIG Ignore, might be response to ignored Request | |
276 | * sCG -> sIG Ignore, might be response to ignored Request | |
277 | * sTW -> sIV Invalid, Request from client in sTW moves to sRQ | |
278 | * | |
279 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
280 | sIV, sRS, sRS, sIG, sIG, sIG, sIG, sIV | |
281 | }, | |
282 | [DCCP_PKT_ACK] = { | |
283 | /* | |
284 | * sNO -> sIV No connection | |
285 | * sRQ -> sIV No connection | |
286 | * sRS -> sIV No connection | |
287 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
288 | * sOP -> sOP Regular Ack in OPEN state | |
289 | * sCR -> sIV Waiting for Close from client | |
290 | * sCG -> sCG Ack in CLOSING MAY be processed (8.3.) | |
291 | * sTW -> sIV | |
292 | * | |
293 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
294 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
295 | }, | |
296 | [DCCP_PKT_DATA] = { | |
297 | /* | |
298 | * sNO -> sIV No connection | |
299 | * sRQ -> sIV No connection | |
300 | * sRS -> sIV No connection | |
301 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
302 | * sOP -> sOP Regular Data packet in OPEN state | |
303 | * sCR -> sIV Waiting for Close from client | |
304 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
305 | * sTW -> sIV | |
306 | * | |
307 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
308 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
309 | }, | |
310 | [DCCP_PKT_DATAACK] = { | |
311 | /* | |
312 | * sNO -> sIV No connection | |
313 | * sRQ -> sIV No connection | |
314 | * sRS -> sIV No connection | |
315 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
316 | * sOP -> sOP Regular DataAck in OPEN state | |
317 | * sCR -> sIV Waiting for Close from client | |
318 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
319 | * sTW -> sIV | |
320 | * | |
321 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
322 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
323 | }, | |
324 | [DCCP_PKT_CLOSEREQ] = { | |
325 | /* | |
326 | * sNO -> sIV No connection | |
327 | * sRQ -> sIV No connection | |
328 | * sRS -> sIV No connection | |
329 | * sPO -> sOP -> sCR Move directly to CLOSEREQ (8.1.5.) | |
330 | * sOP -> sCR CloseReq in OPEN state | |
331 | * sCR -> sCR Retransmit | |
332 | * sCG -> sCR Simultaneous close, client sends another Close | |
333 | * sTW -> sIV Already closed | |
334 | * | |
335 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
336 | sIV, sIV, sIV, sCR, sCR, sCR, sCR, sIV | |
337 | }, | |
338 | [DCCP_PKT_CLOSE] = { | |
339 | /* | |
340 | * sNO -> sIV No connection | |
341 | * sRQ -> sIV No connection | |
342 | * sRS -> sIV No connection | |
343 | * sPO -> sOP -> sCG Move direcly to CLOSING | |
344 | * sOP -> sCG Move to CLOSING | |
345 | * sCR -> sIV Close after CloseReq is invalid | |
346 | * sCG -> sCG Retransmit | |
347 | * sTW -> sIV Already closed | |
348 | * | |
349 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
350 | sIV, sIV, sIV, sCG, sCG, sIV, sCG, sIV | |
351 | }, | |
352 | [DCCP_PKT_RESET] = { | |
353 | /* | |
354 | * sNO -> sIV No connection | |
355 | * sRQ -> sTW Reset in response to Request | |
356 | * sRS -> sTW Timeout, SHOULD send Reset (8.1.3.) | |
357 | * sPO -> sTW Timeout, SHOULD send Reset (8.1.3.) | |
358 | * sOP -> sTW | |
359 | * sCR -> sTW | |
360 | * sCG -> sTW | |
361 | * sTW -> sIG Ignore (don't refresh timer) | |
362 | * | |
363 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW, sTW */ | |
364 | sIV, sTW, sTW, sTW, sTW, sTW, sTW, sTW, sIG | |
365 | }, | |
366 | [DCCP_PKT_SYNC] = { | |
367 | /* | |
368 | * We currently ignore Sync packets | |
369 | * | |
370 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 371 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
372 | }, |
373 | [DCCP_PKT_SYNCACK] = { | |
374 | /* | |
375 | * We currently ignore SyncAck packets | |
376 | * | |
377 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 378 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
379 | }, |
380 | }, | |
381 | }; | |
382 | ||
9976fc6e FW |
383 | static noinline bool |
384 | dccp_new(struct nf_conn *ct, const struct sk_buff *skb, | |
62eec0d7 FW |
385 | const struct dccp_hdr *dh, |
386 | const struct nf_hook_state *hook_state) | |
2bc78049 | 387 | { |
c2a2c7e0 | 388 | struct net *net = nf_ct_net(ct); |
c51d3901 | 389 | struct nf_dccp_net *dn; |
2bc78049 PM |
390 | const char *msg; |
391 | u_int8_t state; | |
392 | ||
2bc78049 PM |
393 | state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE]; |
394 | switch (state) { | |
395 | default: | |
a95a7774 | 396 | dn = nf_dccp_pernet(net); |
1546000f | 397 | if (dn->dccp_loose == 0) { |
3d0b527b | 398 | msg = "not picking up existing connection "; |
2bc78049 PM |
399 | goto out_invalid; |
400 | } | |
c2168e6b | 401 | break; |
2bc78049 PM |
402 | case CT_DCCP_REQUEST: |
403 | break; | |
404 | case CT_DCCP_INVALID: | |
3d0b527b | 405 | msg = "invalid state transition "; |
2bc78049 PM |
406 | goto out_invalid; |
407 | } | |
408 | ||
409 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT; | |
410 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER; | |
411 | ct->proto.dccp.state = CT_DCCP_NONE; | |
e5fc9e7a CG |
412 | ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST; |
413 | ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL; | |
414 | ct->proto.dccp.handshake_seq = 0; | |
09f263cd | 415 | return true; |
2bc78049 PM |
416 | |
417 | out_invalid: | |
62eec0d7 | 418 | nf_ct_l4proto_log_invalid(skb, ct, hook_state, "%s", msg); |
09f263cd | 419 | return false; |
2bc78049 PM |
420 | } |
421 | ||
422 | static u64 dccp_ack_seq(const struct dccp_hdr *dh) | |
423 | { | |
424 | const struct dccp_hdr_ack_bits *dhack; | |
425 | ||
426 | dhack = (void *)dh + __dccp_basic_hdr_len(dh); | |
427 | return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + | |
428 | ntohl(dhack->dccph_ack_nr_low); | |
429 | } | |
430 | ||
0150ffba FW |
431 | static bool dccp_error(const struct dccp_hdr *dh, |
432 | struct sk_buff *skb, unsigned int dataoff, | |
433 | const struct nf_hook_state *state) | |
434 | { | |
435 | unsigned int dccp_len = skb->len - dataoff; | |
436 | unsigned int cscov; | |
437 | const char *msg; | |
438 | ||
439 | if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) || | |
440 | dh->dccph_doff * 4 > dccp_len) { | |
441 | msg = "nf_ct_dccp: truncated/malformed packet "; | |
442 | goto out_invalid; | |
443 | } | |
444 | ||
445 | cscov = dccp_len; | |
446 | if (dh->dccph_cscov) { | |
447 | cscov = (dh->dccph_cscov - 1) * 4; | |
448 | if (cscov > dccp_len) { | |
449 | msg = "nf_ct_dccp: bad checksum coverage "; | |
450 | goto out_invalid; | |
451 | } | |
452 | } | |
453 | ||
454 | if (state->hook == NF_INET_PRE_ROUTING && | |
455 | state->net->ct.sysctl_checksum && | |
456 | nf_checksum_partial(skb, state->hook, dataoff, cscov, | |
457 | IPPROTO_DCCP, state->pf)) { | |
458 | msg = "nf_ct_dccp: bad checksum "; | |
459 | goto out_invalid; | |
460 | } | |
461 | ||
462 | if (dh->dccph_type >= DCCP_PKT_INVALID) { | |
463 | msg = "nf_ct_dccp: reserved packet type "; | |
464 | goto out_invalid; | |
465 | } | |
466 | return false; | |
467 | out_invalid: | |
62eec0d7 | 468 | nf_l4proto_log_invalid(skb, state, IPPROTO_DCCP, "%s", msg); |
0150ffba FW |
469 | return true; |
470 | } | |
471 | ||
a47c5404 FW |
472 | int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb, |
473 | unsigned int dataoff, | |
474 | enum ip_conntrack_info ctinfo, | |
475 | const struct nf_hook_state *state) | |
2bc78049 PM |
476 | { |
477 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
478 | struct dccp_hdr _dh, *dh; | |
479 | u_int8_t type, old_state, new_state; | |
480 | enum ct_dccp_roles role; | |
c779e849 | 481 | unsigned int *timeouts; |
2bc78049 | 482 | |
b22f5126 | 483 | dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); |
9976fc6e FW |
484 | if (!dh) |
485 | return NF_DROP; | |
486 | ||
0150ffba FW |
487 | if (dccp_error(dh, skb, dataoff, state)) |
488 | return -NF_ACCEPT; | |
489 | ||
2bc78049 | 490 | type = dh->dccph_type; |
62eec0d7 | 491 | if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh, state)) |
9976fc6e | 492 | return -NF_ACCEPT; |
2bc78049 PM |
493 | |
494 | if (type == DCCP_PKT_RESET && | |
495 | !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
496 | /* Tear down connection immediately if only reply is a RESET */ | |
718d4ad9 | 497 | nf_ct_kill_acct(ct, ctinfo, skb); |
2bc78049 PM |
498 | return NF_ACCEPT; |
499 | } | |
500 | ||
440f0d58 | 501 | spin_lock_bh(&ct->lock); |
2bc78049 PM |
502 | |
503 | role = ct->proto.dccp.role[dir]; | |
504 | old_state = ct->proto.dccp.state; | |
505 | new_state = dccp_state_table[role][type][old_state]; | |
506 | ||
507 | switch (new_state) { | |
508 | case CT_DCCP_REQUEST: | |
509 | if (old_state == CT_DCCP_TIMEWAIT && | |
510 | role == CT_DCCP_ROLE_SERVER) { | |
511 | /* Reincarnation in the reverse direction: reopen and | |
512 | * reverse client/server roles. */ | |
513 | ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT; | |
514 | ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER; | |
515 | } | |
516 | break; | |
517 | case CT_DCCP_RESPOND: | |
518 | if (old_state == CT_DCCP_REQUEST) | |
519 | ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh); | |
520 | break; | |
521 | case CT_DCCP_PARTOPEN: | |
522 | if (old_state == CT_DCCP_RESPOND && | |
523 | type == DCCP_PKT_ACK && | |
524 | dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq) | |
525 | set_bit(IPS_ASSURED_BIT, &ct->status); | |
526 | break; | |
527 | case CT_DCCP_IGNORE: | |
528 | /* | |
529 | * Connection tracking might be out of sync, so we ignore | |
530 | * packets that might establish a new connection and resync | |
531 | * if the server responds with a valid Response. | |
532 | */ | |
533 | if (ct->proto.dccp.last_dir == !dir && | |
534 | ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST && | |
535 | type == DCCP_PKT_RESPONSE) { | |
536 | ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT; | |
537 | ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER; | |
538 | ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh); | |
539 | new_state = CT_DCCP_RESPOND; | |
540 | break; | |
541 | } | |
542 | ct->proto.dccp.last_dir = dir; | |
543 | ct->proto.dccp.last_pkt = type; | |
544 | ||
440f0d58 | 545 | spin_unlock_bh(&ct->lock); |
62eec0d7 | 546 | nf_ct_l4proto_log_invalid(skb, ct, state, "%s", "invalid packet"); |
2bc78049 PM |
547 | return NF_ACCEPT; |
548 | case CT_DCCP_INVALID: | |
440f0d58 | 549 | spin_unlock_bh(&ct->lock); |
62eec0d7 | 550 | nf_ct_l4proto_log_invalid(skb, ct, state, "%s", "invalid state transition"); |
2bc78049 PM |
551 | return -NF_ACCEPT; |
552 | } | |
553 | ||
554 | ct->proto.dccp.last_dir = dir; | |
555 | ct->proto.dccp.last_pkt = type; | |
556 | ct->proto.dccp.state = new_state; | |
440f0d58 | 557 | spin_unlock_bh(&ct->lock); |
1546000f | 558 | |
b38b1f61 PNA |
559 | if (new_state != old_state) |
560 | nf_conntrack_event_cache(IPCT_PROTOINFO, ct); | |
561 | ||
c779e849 FW |
562 | timeouts = nf_ct_timeout_lookup(ct); |
563 | if (!timeouts) | |
a95a7774 | 564 | timeouts = nf_dccp_pernet(nf_ct_net(ct))->dccp_timeout; |
2c8503f5 | 565 | nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]); |
2bc78049 PM |
566 | |
567 | return NF_ACCEPT; | |
568 | } | |
569 | ||
c6dd940b FW |
570 | static bool dccp_can_early_drop(const struct nf_conn *ct) |
571 | { | |
572 | switch (ct->proto.dccp.state) { | |
573 | case CT_DCCP_CLOSEREQ: | |
574 | case CT_DCCP_CLOSING: | |
575 | case CT_DCCP_TIMEWAIT: | |
576 | return true; | |
577 | default: | |
578 | break; | |
579 | } | |
580 | ||
581 | return false; | |
582 | } | |
583 | ||
ea48cc83 | 584 | #ifdef CONFIG_NF_CONNTRACK_PROCFS |
37246a58 | 585 | static void dccp_print_conntrack(struct seq_file *s, struct nf_conn *ct) |
2bc78049 | 586 | { |
37246a58 | 587 | seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]); |
2bc78049 | 588 | } |
ea48cc83 | 589 | #endif |
2bc78049 | 590 | |
c0cd1156 | 591 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
2bc78049 | 592 | static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla, |
86d21fc7 | 593 | struct nf_conn *ct, bool destroy) |
2bc78049 PM |
594 | { |
595 | struct nlattr *nest_parms; | |
596 | ||
440f0d58 | 597 | spin_lock_bh(&ct->lock); |
ae0be8de | 598 | nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP); |
2bc78049 PM |
599 | if (!nest_parms) |
600 | goto nla_put_failure; | |
86d21fc7 FW |
601 | if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state)) |
602 | goto nla_put_failure; | |
603 | ||
604 | if (destroy) | |
605 | goto skip_state; | |
606 | ||
607 | if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_ROLE, | |
516ee48f DM |
608 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]) || |
609 | nla_put_be64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ, | |
b46f6ded ND |
610 | cpu_to_be64(ct->proto.dccp.handshake_seq), |
611 | CTA_PROTOINFO_DCCP_PAD)) | |
516ee48f | 612 | goto nla_put_failure; |
86d21fc7 | 613 | skip_state: |
2bc78049 | 614 | nla_nest_end(skb, nest_parms); |
440f0d58 | 615 | spin_unlock_bh(&ct->lock); |
86d21fc7 | 616 | |
2bc78049 PM |
617 | return 0; |
618 | ||
619 | nla_put_failure: | |
440f0d58 | 620 | spin_unlock_bh(&ct->lock); |
2bc78049 PM |
621 | return -1; |
622 | } | |
623 | ||
624 | static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = { | |
625 | [CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 }, | |
71951b64 | 626 | [CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 }, |
a17c8598 | 627 | [CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 }, |
b46f6ded | 628 | [CTA_PROTOINFO_DCCP_PAD] = { .type = NLA_UNSPEC }, |
2bc78049 PM |
629 | }; |
630 | ||
39215846 FW |
631 | #define DCCP_NLATTR_SIZE ( \ |
632 | NLA_ALIGN(NLA_HDRLEN + 1) + \ | |
633 | NLA_ALIGN(NLA_HDRLEN + 1) + \ | |
634 | NLA_ALIGN(NLA_HDRLEN + sizeof(u64)) + \ | |
635 | NLA_ALIGN(NLA_HDRLEN + 0)) | |
636 | ||
2bc78049 PM |
637 | static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct) |
638 | { | |
639 | struct nlattr *attr = cda[CTA_PROTOINFO_DCCP]; | |
640 | struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1]; | |
641 | int err; | |
642 | ||
643 | if (!attr) | |
644 | return 0; | |
645 | ||
8cb08174 JB |
646 | err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_DCCP_MAX, attr, |
647 | dccp_nla_policy, NULL); | |
2bc78049 PM |
648 | if (err < 0) |
649 | return err; | |
650 | ||
651 | if (!tb[CTA_PROTOINFO_DCCP_STATE] || | |
71951b64 PNA |
652 | !tb[CTA_PROTOINFO_DCCP_ROLE] || |
653 | nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX || | |
654 | nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) { | |
2bc78049 | 655 | return -EINVAL; |
71951b64 | 656 | } |
2bc78049 | 657 | |
440f0d58 | 658 | spin_lock_bh(&ct->lock); |
2bc78049 | 659 | ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]); |
71951b64 PNA |
660 | if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) { |
661 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT; | |
662 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER; | |
663 | } else { | |
664 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER; | |
665 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT; | |
666 | } | |
a17c8598 PNA |
667 | if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) { |
668 | ct->proto.dccp.handshake_seq = | |
669 | be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ])); | |
670 | } | |
440f0d58 | 671 | spin_unlock_bh(&ct->lock); |
2bc78049 PM |
672 | return 0; |
673 | } | |
674 | #endif | |
675 | ||
a874752a | 676 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
677 | |
678 | #include <linux/netfilter/nfnetlink.h> | |
679 | #include <linux/netfilter/nfnetlink_cttimeout.h> | |
680 | ||
8264deb8 G |
681 | static int dccp_timeout_nlattr_to_obj(struct nlattr *tb[], |
682 | struct net *net, void *data) | |
50978462 | 683 | { |
a95a7774 | 684 | struct nf_dccp_net *dn = nf_dccp_pernet(net); |
50978462 PNA |
685 | unsigned int *timeouts = data; |
686 | int i; | |
687 | ||
1d9a7acd FW |
688 | if (!timeouts) |
689 | timeouts = dn->dccp_timeout; | |
690 | ||
50978462 PNA |
691 | /* set default DCCP timeouts. */ |
692 | for (i=0; i<CT_DCCP_MAX; i++) | |
693 | timeouts[i] = dn->dccp_timeout[i]; | |
694 | ||
695 | /* there's a 1:1 mapping between attributes and protocol states. */ | |
696 | for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) { | |
697 | if (tb[i]) { | |
698 | timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ; | |
699 | } | |
700 | } | |
ef39078d FW |
701 | |
702 | timeouts[CTA_TIMEOUT_DCCP_UNSPEC] = timeouts[CTA_TIMEOUT_DCCP_REQUEST]; | |
50978462 PNA |
703 | return 0; |
704 | } | |
705 | ||
706 | static int | |
707 | dccp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) | |
708 | { | |
709 | const unsigned int *timeouts = data; | |
710 | int i; | |
711 | ||
516ee48f DM |
712 | for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) { |
713 | if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ))) | |
714 | goto nla_put_failure; | |
715 | } | |
50978462 PNA |
716 | return 0; |
717 | ||
718 | nla_put_failure: | |
719 | return -ENOSPC; | |
720 | } | |
721 | ||
722 | static const struct nla_policy | |
723 | dccp_timeout_nla_policy[CTA_TIMEOUT_DCCP_MAX+1] = { | |
724 | [CTA_TIMEOUT_DCCP_REQUEST] = { .type = NLA_U32 }, | |
725 | [CTA_TIMEOUT_DCCP_RESPOND] = { .type = NLA_U32 }, | |
726 | [CTA_TIMEOUT_DCCP_PARTOPEN] = { .type = NLA_U32 }, | |
727 | [CTA_TIMEOUT_DCCP_OPEN] = { .type = NLA_U32 }, | |
728 | [CTA_TIMEOUT_DCCP_CLOSEREQ] = { .type = NLA_U32 }, | |
729 | [CTA_TIMEOUT_DCCP_CLOSING] = { .type = NLA_U32 }, | |
730 | [CTA_TIMEOUT_DCCP_TIMEWAIT] = { .type = NLA_U32 }, | |
731 | }; | |
a874752a | 732 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
50978462 | 733 | |
2a389de8 | 734 | void nf_conntrack_dccp_init_net(struct net *net) |
84c39451 | 735 | { |
a95a7774 | 736 | struct nf_dccp_net *dn = nf_dccp_pernet(net); |
84c39451 | 737 | |
2a389de8 FW |
738 | /* default values */ |
739 | dn->dccp_loose = 1; | |
740 | dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL; | |
741 | dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL; | |
742 | dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL; | |
743 | dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ; | |
744 | dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ; | |
745 | dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ; | |
746 | dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL; | |
747 | ||
748 | /* timeouts[0] is unused, make it same as SYN_SENT so | |
749 | * ->timeouts[0] contains 'new' timeout, like udp or icmp. | |
750 | */ | |
751 | dn->dccp_timeout[CT_DCCP_NONE] = dn->dccp_timeout[CT_DCCP_REQUEST]; | |
deaa0a97 LZ |
752 | } |
753 | ||
dd2934a9 | 754 | const struct nf_conntrack_l4proto nf_conntrack_l4proto_dccp = { |
2bc78049 | 755 | .l4proto = IPPROTO_DCCP, |
c6dd940b | 756 | .can_early_drop = dccp_can_early_drop, |
ea48cc83 | 757 | #ifdef CONFIG_NF_CONNTRACK_PROCFS |
2bc78049 | 758 | .print_conntrack = dccp_print_conntrack, |
ea48cc83 | 759 | #endif |
c0cd1156 | 760 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
39215846 | 761 | .nlattr_size = DCCP_NLATTR_SIZE, |
2bc78049 PM |
762 | .to_nlattr = dccp_to_nlattr, |
763 | .from_nlattr = nlattr_to_dccp, | |
764 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, | |
a400c30e | 765 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
2bc78049 PM |
766 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
767 | .nla_policy = nf_ct_port_nla_policy, | |
768 | #endif | |
a874752a | 769 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
770 | .ctnl_timeout = { |
771 | .nlattr_to_obj = dccp_timeout_nlattr_to_obj, | |
772 | .obj_to_nlattr = dccp_timeout_obj_to_nlattr, | |
773 | .nlattr_max = CTA_TIMEOUT_DCCP_MAX, | |
774 | .obj_size = sizeof(unsigned int) * CT_DCCP_MAX, | |
775 | .nla_policy = dccp_timeout_nla_policy, | |
776 | }, | |
a874752a | 777 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
2bc78049 | 778 | }; |