Commit | Line | Data |
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2bc78049 PM |
1 | /* |
2 | * DCCP connection tracking protocol helper | |
3 | * | |
4 | * Copyright (c) 2005, 2006, 2008 Patrick McHardy <kaber@trash.net> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | #include <linux/kernel.h> | |
2bc78049 PM |
12 | #include <linux/init.h> |
13 | #include <linux/sysctl.h> | |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/skbuff.h> | |
16 | #include <linux/dccp.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
2bc78049 | 18 | |
1546000f CG |
19 | #include <net/net_namespace.h> |
20 | #include <net/netns/generic.h> | |
21 | ||
2bc78049 PM |
22 | #include <linux/netfilter/nfnetlink_conntrack.h> |
23 | #include <net/netfilter/nf_conntrack.h> | |
24 | #include <net/netfilter/nf_conntrack_l4proto.h> | |
b38b1f61 | 25 | #include <net/netfilter/nf_conntrack_ecache.h> |
c779e849 | 26 | #include <net/netfilter/nf_conntrack_timeout.h> |
2bc78049 PM |
27 | #include <net/netfilter/nf_log.h> |
28 | ||
2bc78049 PM |
29 | /* Timeouts are based on values from RFC4340: |
30 | * | |
31 | * - REQUEST: | |
32 | * | |
33 | * 8.1.2. Client Request | |
34 | * | |
35 | * A client MAY give up on its DCCP-Requests after some time | |
36 | * (3 minutes, for example). | |
37 | * | |
38 | * - RESPOND: | |
39 | * | |
40 | * 8.1.3. Server Response | |
41 | * | |
42 | * It MAY also leave the RESPOND state for CLOSED after a timeout of | |
43 | * not less than 4MSL (8 minutes); | |
44 | * | |
45 | * - PARTOPEN: | |
46 | * | |
47 | * 8.1.5. Handshake Completion | |
48 | * | |
49 | * If the client remains in PARTOPEN for more than 4MSL (8 minutes), | |
50 | * it SHOULD reset the connection with Reset Code 2, "Aborted". | |
51 | * | |
52 | * - OPEN: | |
53 | * | |
54 | * The DCCP timestamp overflows after 11.9 hours. If the connection | |
55 | * stays idle this long the sequence number won't be recognized | |
56 | * as valid anymore. | |
57 | * | |
58 | * - CLOSEREQ/CLOSING: | |
59 | * | |
60 | * 8.3. Termination | |
61 | * | |
62 | * The retransmission timer should initially be set to go off in two | |
63 | * round-trip times and should back off to not less than once every | |
64 | * 64 seconds ... | |
65 | * | |
66 | * - TIMEWAIT: | |
67 | * | |
68 | * 4.3. States | |
69 | * | |
70 | * A server or client socket remains in this state for 2MSL (4 minutes) | |
71 | * after the connection has been town down, ... | |
72 | */ | |
73 | ||
74 | #define DCCP_MSL (2 * 60 * HZ) | |
75 | ||
2bc78049 PM |
76 | static const char * const dccp_state_names[] = { |
77 | [CT_DCCP_NONE] = "NONE", | |
78 | [CT_DCCP_REQUEST] = "REQUEST", | |
79 | [CT_DCCP_RESPOND] = "RESPOND", | |
80 | [CT_DCCP_PARTOPEN] = "PARTOPEN", | |
81 | [CT_DCCP_OPEN] = "OPEN", | |
82 | [CT_DCCP_CLOSEREQ] = "CLOSEREQ", | |
83 | [CT_DCCP_CLOSING] = "CLOSING", | |
84 | [CT_DCCP_TIMEWAIT] = "TIMEWAIT", | |
85 | [CT_DCCP_IGNORE] = "IGNORE", | |
86 | [CT_DCCP_INVALID] = "INVALID", | |
87 | }; | |
88 | ||
89 | #define sNO CT_DCCP_NONE | |
90 | #define sRQ CT_DCCP_REQUEST | |
91 | #define sRS CT_DCCP_RESPOND | |
92 | #define sPO CT_DCCP_PARTOPEN | |
93 | #define sOP CT_DCCP_OPEN | |
94 | #define sCR CT_DCCP_CLOSEREQ | |
95 | #define sCG CT_DCCP_CLOSING | |
96 | #define sTW CT_DCCP_TIMEWAIT | |
97 | #define sIG CT_DCCP_IGNORE | |
98 | #define sIV CT_DCCP_INVALID | |
99 | ||
100 | /* | |
25985edc | 101 | * DCCP state transition table |
2bc78049 PM |
102 | * |
103 | * The assumption is the same as for TCP tracking: | |
104 | * | |
105 | * We are the man in the middle. All the packets go through us but might | |
106 | * get lost in transit to the destination. It is assumed that the destination | |
107 | * can't receive segments we haven't seen. | |
108 | * | |
109 | * The following states exist: | |
110 | * | |
111 | * NONE: Initial state, expecting Request | |
112 | * REQUEST: Request seen, waiting for Response from server | |
113 | * RESPOND: Response from server seen, waiting for Ack from client | |
114 | * PARTOPEN: Ack after Response seen, waiting for packet other than Response, | |
115 | * Reset or Sync from server | |
116 | * OPEN: Packet other than Response, Reset or Sync seen | |
117 | * CLOSEREQ: CloseReq from server seen, expecting Close from client | |
118 | * CLOSING: Close seen, expecting Reset | |
119 | * TIMEWAIT: Reset seen | |
120 | * IGNORE: Not determinable whether packet is valid | |
121 | * | |
122 | * Some states exist only on one side of the connection: REQUEST, RESPOND, | |
123 | * PARTOPEN, CLOSEREQ. For the other side these states are equivalent to | |
124 | * the one it was in before. | |
125 | * | |
126 | * Packets are marked as ignored (sIG) if we don't know if they're valid | |
127 | * (for example a reincarnation of a connection we didn't notice is dead | |
128 | * already) and the server may send back a connection closing Reset or a | |
129 | * Response. They're also used for Sync/SyncAck packets, which we don't | |
130 | * care about. | |
131 | */ | |
132 | static const u_int8_t | |
133 | dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] = { | |
134 | [CT_DCCP_ROLE_CLIENT] = { | |
135 | [DCCP_PKT_REQUEST] = { | |
136 | /* | |
137 | * sNO -> sRQ Regular Request | |
138 | * sRQ -> sRQ Retransmitted Request or reincarnation | |
139 | * sRS -> sRS Retransmitted Request (apparently Response | |
140 | * got lost after we saw it) or reincarnation | |
141 | * sPO -> sIG Ignore, conntrack might be out of sync | |
142 | * sOP -> sIG Ignore, conntrack might be out of sync | |
143 | * sCR -> sIG Ignore, conntrack might be out of sync | |
144 | * sCG -> sIG Ignore, conntrack might be out of sync | |
145 | * sTW -> sRQ Reincarnation | |
146 | * | |
147 | * sNO, sRQ, sRS, sPO. sOP, sCR, sCG, sTW, */ | |
148 | sRQ, sRQ, sRS, sIG, sIG, sIG, sIG, sRQ, | |
149 | }, | |
150 | [DCCP_PKT_RESPONSE] = { | |
151 | /* | |
152 | * sNO -> sIV Invalid | |
153 | * sRQ -> sIG Ignore, might be response to ignored Request | |
154 | * sRS -> sIG Ignore, might be response to ignored Request | |
155 | * sPO -> sIG Ignore, might be response to ignored Request | |
156 | * sOP -> sIG Ignore, might be response to ignored Request | |
157 | * sCR -> sIG Ignore, might be response to ignored Request | |
158 | * sCG -> sIG Ignore, might be response to ignored Request | |
159 | * sTW -> sIV Invalid, reincarnation in reverse direction | |
160 | * goes through sRQ | |
161 | * | |
162 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
163 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIV, | |
164 | }, | |
165 | [DCCP_PKT_ACK] = { | |
166 | /* | |
167 | * sNO -> sIV No connection | |
168 | * sRQ -> sIV No connection | |
169 | * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.) | |
170 | * sPO -> sPO Retransmitted Ack for Response, remain in PARTOPEN | |
171 | * sOP -> sOP Regular ACK, remain in OPEN | |
172 | * sCR -> sCR Ack in CLOSEREQ MAY be processed (8.3.) | |
173 | * sCG -> sCG Ack in CLOSING MAY be processed (8.3.) | |
174 | * sTW -> sIV | |
175 | * | |
176 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
177 | sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV | |
178 | }, | |
179 | [DCCP_PKT_DATA] = { | |
180 | /* | |
181 | * sNO -> sIV No connection | |
182 | * sRQ -> sIV No connection | |
183 | * sRS -> sIV No connection | |
184 | * sPO -> sIV MUST use DataAck in PARTOPEN state (8.1.5.) | |
185 | * sOP -> sOP Regular Data packet | |
186 | * sCR -> sCR Data in CLOSEREQ MAY be processed (8.3.) | |
187 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
188 | * sTW -> sIV | |
189 | * | |
190 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
191 | sIV, sIV, sIV, sIV, sOP, sCR, sCG, sIV, | |
192 | }, | |
193 | [DCCP_PKT_DATAACK] = { | |
194 | /* | |
195 | * sNO -> sIV No connection | |
196 | * sRQ -> sIV No connection | |
197 | * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.) | |
198 | * sPO -> sPO Remain in PARTOPEN state | |
199 | * sOP -> sOP Regular DataAck packet in OPEN state | |
200 | * sCR -> sCR DataAck in CLOSEREQ MAY be processed (8.3.) | |
201 | * sCG -> sCG DataAck in CLOSING MAY be processed (8.3.) | |
202 | * sTW -> sIV | |
203 | * | |
204 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
205 | sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV | |
206 | }, | |
207 | [DCCP_PKT_CLOSEREQ] = { | |
208 | /* | |
209 | * CLOSEREQ may only be sent by the server. | |
210 | * | |
211 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
212 | sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV | |
213 | }, | |
214 | [DCCP_PKT_CLOSE] = { | |
215 | /* | |
216 | * sNO -> sIV No connection | |
217 | * sRQ -> sIV No connection | |
218 | * sRS -> sIV No connection | |
219 | * sPO -> sCG Client-initiated close | |
220 | * sOP -> sCG Client-initiated close | |
221 | * sCR -> sCG Close in response to CloseReq (8.3.) | |
222 | * sCG -> sCG Retransmit | |
223 | * sTW -> sIV Late retransmit, already in TIME_WAIT | |
224 | * | |
225 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
226 | sIV, sIV, sIV, sCG, sCG, sCG, sIV, sIV | |
227 | }, | |
228 | [DCCP_PKT_RESET] = { | |
229 | /* | |
230 | * sNO -> sIV No connection | |
231 | * sRQ -> sTW Sync received or timeout, SHOULD send Reset (8.1.1.) | |
232 | * sRS -> sTW Response received without Request | |
233 | * sPO -> sTW Timeout, SHOULD send Reset (8.1.5.) | |
234 | * sOP -> sTW Connection reset | |
235 | * sCR -> sTW Connection reset | |
236 | * sCG -> sTW Connection reset | |
237 | * sTW -> sIG Ignore (don't refresh timer) | |
238 | * | |
239 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
240 | sIV, sTW, sTW, sTW, sTW, sTW, sTW, sIG | |
241 | }, | |
242 | [DCCP_PKT_SYNC] = { | |
243 | /* | |
244 | * We currently ignore Sync packets | |
245 | * | |
246 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 247 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
248 | }, |
249 | [DCCP_PKT_SYNCACK] = { | |
250 | /* | |
251 | * We currently ignore SyncAck packets | |
252 | * | |
253 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 254 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
255 | }, |
256 | }, | |
257 | [CT_DCCP_ROLE_SERVER] = { | |
258 | [DCCP_PKT_REQUEST] = { | |
259 | /* | |
260 | * sNO -> sIV Invalid | |
261 | * sRQ -> sIG Ignore, conntrack might be out of sync | |
262 | * sRS -> sIG Ignore, conntrack might be out of sync | |
263 | * sPO -> sIG Ignore, conntrack might be out of sync | |
264 | * sOP -> sIG Ignore, conntrack might be out of sync | |
265 | * sCR -> sIG Ignore, conntrack might be out of sync | |
266 | * sCG -> sIG Ignore, conntrack might be out of sync | |
267 | * sTW -> sRQ Reincarnation, must reverse roles | |
268 | * | |
269 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
270 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sRQ | |
271 | }, | |
272 | [DCCP_PKT_RESPONSE] = { | |
273 | /* | |
274 | * sNO -> sIV Response without Request | |
275 | * sRQ -> sRS Response to clients Request | |
276 | * sRS -> sRS Retransmitted Response (8.1.3. SHOULD NOT) | |
277 | * sPO -> sIG Response to an ignored Request or late retransmit | |
278 | * sOP -> sIG Ignore, might be response to ignored Request | |
279 | * sCR -> sIG Ignore, might be response to ignored Request | |
280 | * sCG -> sIG Ignore, might be response to ignored Request | |
281 | * sTW -> sIV Invalid, Request from client in sTW moves to sRQ | |
282 | * | |
283 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
284 | sIV, sRS, sRS, sIG, sIG, sIG, sIG, sIV | |
285 | }, | |
286 | [DCCP_PKT_ACK] = { | |
287 | /* | |
288 | * sNO -> sIV No connection | |
289 | * sRQ -> sIV No connection | |
290 | * sRS -> sIV No connection | |
291 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
292 | * sOP -> sOP Regular Ack in OPEN state | |
293 | * sCR -> sIV Waiting for Close from client | |
294 | * sCG -> sCG Ack in CLOSING MAY be processed (8.3.) | |
295 | * sTW -> sIV | |
296 | * | |
297 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
298 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
299 | }, | |
300 | [DCCP_PKT_DATA] = { | |
301 | /* | |
302 | * sNO -> sIV No connection | |
303 | * sRQ -> sIV No connection | |
304 | * sRS -> sIV No connection | |
305 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
306 | * sOP -> sOP Regular Data packet in OPEN state | |
307 | * sCR -> sIV Waiting for Close from client | |
308 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
309 | * sTW -> sIV | |
310 | * | |
311 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
312 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
313 | }, | |
314 | [DCCP_PKT_DATAACK] = { | |
315 | /* | |
316 | * sNO -> sIV No connection | |
317 | * sRQ -> sIV No connection | |
318 | * sRS -> sIV No connection | |
319 | * sPO -> sOP Enter OPEN state (8.1.5.) | |
320 | * sOP -> sOP Regular DataAck in OPEN state | |
321 | * sCR -> sIV Waiting for Close from client | |
322 | * sCG -> sCG Data in CLOSING MAY be processed (8.3.) | |
323 | * sTW -> sIV | |
324 | * | |
325 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
326 | sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV | |
327 | }, | |
328 | [DCCP_PKT_CLOSEREQ] = { | |
329 | /* | |
330 | * sNO -> sIV No connection | |
331 | * sRQ -> sIV No connection | |
332 | * sRS -> sIV No connection | |
333 | * sPO -> sOP -> sCR Move directly to CLOSEREQ (8.1.5.) | |
334 | * sOP -> sCR CloseReq in OPEN state | |
335 | * sCR -> sCR Retransmit | |
336 | * sCG -> sCR Simultaneous close, client sends another Close | |
337 | * sTW -> sIV Already closed | |
338 | * | |
339 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
340 | sIV, sIV, sIV, sCR, sCR, sCR, sCR, sIV | |
341 | }, | |
342 | [DCCP_PKT_CLOSE] = { | |
343 | /* | |
344 | * sNO -> sIV No connection | |
345 | * sRQ -> sIV No connection | |
346 | * sRS -> sIV No connection | |
347 | * sPO -> sOP -> sCG Move direcly to CLOSING | |
348 | * sOP -> sCG Move to CLOSING | |
349 | * sCR -> sIV Close after CloseReq is invalid | |
350 | * sCG -> sCG Retransmit | |
351 | * sTW -> sIV Already closed | |
352 | * | |
353 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
354 | sIV, sIV, sIV, sCG, sCG, sIV, sCG, sIV | |
355 | }, | |
356 | [DCCP_PKT_RESET] = { | |
357 | /* | |
358 | * sNO -> sIV No connection | |
359 | * sRQ -> sTW Reset in response to Request | |
360 | * sRS -> sTW Timeout, SHOULD send Reset (8.1.3.) | |
361 | * sPO -> sTW Timeout, SHOULD send Reset (8.1.3.) | |
362 | * sOP -> sTW | |
363 | * sCR -> sTW | |
364 | * sCG -> sTW | |
365 | * sTW -> sIG Ignore (don't refresh timer) | |
366 | * | |
367 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW, sTW */ | |
368 | sIV, sTW, sTW, sTW, sTW, sTW, sTW, sTW, sIG | |
369 | }, | |
370 | [DCCP_PKT_SYNC] = { | |
371 | /* | |
372 | * We currently ignore Sync packets | |
373 | * | |
374 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 375 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
376 | }, |
377 | [DCCP_PKT_SYNCACK] = { | |
378 | /* | |
379 | * We currently ignore SyncAck packets | |
380 | * | |
381 | * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */ | |
6613b617 | 382 | sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, |
2bc78049 PM |
383 | }, |
384 | }, | |
385 | }; | |
386 | ||
9976fc6e FW |
387 | static noinline bool |
388 | dccp_new(struct nf_conn *ct, const struct sk_buff *skb, | |
389 | const struct dccp_hdr *dh) | |
2bc78049 | 390 | { |
c2a2c7e0 | 391 | struct net *net = nf_ct_net(ct); |
c51d3901 | 392 | struct nf_dccp_net *dn; |
2bc78049 PM |
393 | const char *msg; |
394 | u_int8_t state; | |
395 | ||
2bc78049 PM |
396 | state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE]; |
397 | switch (state) { | |
398 | default: | |
a95a7774 | 399 | dn = nf_dccp_pernet(net); |
1546000f | 400 | if (dn->dccp_loose == 0) { |
3d0b527b | 401 | msg = "not picking up existing connection "; |
2bc78049 PM |
402 | goto out_invalid; |
403 | } | |
404 | case CT_DCCP_REQUEST: | |
405 | break; | |
406 | case CT_DCCP_INVALID: | |
3d0b527b | 407 | msg = "invalid state transition "; |
2bc78049 PM |
408 | goto out_invalid; |
409 | } | |
410 | ||
411 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT; | |
412 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER; | |
413 | ct->proto.dccp.state = CT_DCCP_NONE; | |
e5fc9e7a CG |
414 | ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST; |
415 | ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL; | |
416 | ct->proto.dccp.handshake_seq = 0; | |
09f263cd | 417 | return true; |
2bc78049 PM |
418 | |
419 | out_invalid: | |
3d0b527b | 420 | nf_ct_l4proto_log_invalid(skb, ct, "%s", msg); |
09f263cd | 421 | return false; |
2bc78049 PM |
422 | } |
423 | ||
424 | static u64 dccp_ack_seq(const struct dccp_hdr *dh) | |
425 | { | |
426 | const struct dccp_hdr_ack_bits *dhack; | |
427 | ||
428 | dhack = (void *)dh + __dccp_basic_hdr_len(dh); | |
429 | return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + | |
430 | ntohl(dhack->dccph_ack_nr_low); | |
431 | } | |
432 | ||
0150ffba FW |
433 | static bool dccp_error(const struct dccp_hdr *dh, |
434 | struct sk_buff *skb, unsigned int dataoff, | |
435 | const struct nf_hook_state *state) | |
436 | { | |
437 | unsigned int dccp_len = skb->len - dataoff; | |
438 | unsigned int cscov; | |
439 | const char *msg; | |
440 | ||
441 | if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) || | |
442 | dh->dccph_doff * 4 > dccp_len) { | |
443 | msg = "nf_ct_dccp: truncated/malformed packet "; | |
444 | goto out_invalid; | |
445 | } | |
446 | ||
447 | cscov = dccp_len; | |
448 | if (dh->dccph_cscov) { | |
449 | cscov = (dh->dccph_cscov - 1) * 4; | |
450 | if (cscov > dccp_len) { | |
451 | msg = "nf_ct_dccp: bad checksum coverage "; | |
452 | goto out_invalid; | |
453 | } | |
454 | } | |
455 | ||
456 | if (state->hook == NF_INET_PRE_ROUTING && | |
457 | state->net->ct.sysctl_checksum && | |
458 | nf_checksum_partial(skb, state->hook, dataoff, cscov, | |
459 | IPPROTO_DCCP, state->pf)) { | |
460 | msg = "nf_ct_dccp: bad checksum "; | |
461 | goto out_invalid; | |
462 | } | |
463 | ||
464 | if (dh->dccph_type >= DCCP_PKT_INVALID) { | |
465 | msg = "nf_ct_dccp: reserved packet type "; | |
466 | goto out_invalid; | |
467 | } | |
468 | return false; | |
469 | out_invalid: | |
470 | nf_l4proto_log_invalid(skb, state->net, state->pf, | |
471 | IPPROTO_DCCP, "%s", msg); | |
472 | return true; | |
473 | } | |
474 | ||
83d213fd | 475 | static int dccp_packet(struct nf_conn *ct, struct sk_buff *skb, |
93e66024 FW |
476 | unsigned int dataoff, enum ip_conntrack_info ctinfo, |
477 | const struct nf_hook_state *state) | |
2bc78049 PM |
478 | { |
479 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
480 | struct dccp_hdr _dh, *dh; | |
481 | u_int8_t type, old_state, new_state; | |
482 | enum ct_dccp_roles role; | |
c779e849 | 483 | unsigned int *timeouts; |
2bc78049 | 484 | |
b22f5126 | 485 | dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); |
9976fc6e FW |
486 | if (!dh) |
487 | return NF_DROP; | |
488 | ||
0150ffba FW |
489 | if (dccp_error(dh, skb, dataoff, state)) |
490 | return -NF_ACCEPT; | |
491 | ||
2bc78049 | 492 | type = dh->dccph_type; |
9976fc6e FW |
493 | if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh)) |
494 | return -NF_ACCEPT; | |
2bc78049 PM |
495 | |
496 | if (type == DCCP_PKT_RESET && | |
497 | !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
498 | /* Tear down connection immediately if only reply is a RESET */ | |
718d4ad9 | 499 | nf_ct_kill_acct(ct, ctinfo, skb); |
2bc78049 PM |
500 | return NF_ACCEPT; |
501 | } | |
502 | ||
440f0d58 | 503 | spin_lock_bh(&ct->lock); |
2bc78049 PM |
504 | |
505 | role = ct->proto.dccp.role[dir]; | |
506 | old_state = ct->proto.dccp.state; | |
507 | new_state = dccp_state_table[role][type][old_state]; | |
508 | ||
509 | switch (new_state) { | |
510 | case CT_DCCP_REQUEST: | |
511 | if (old_state == CT_DCCP_TIMEWAIT && | |
512 | role == CT_DCCP_ROLE_SERVER) { | |
513 | /* Reincarnation in the reverse direction: reopen and | |
514 | * reverse client/server roles. */ | |
515 | ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT; | |
516 | ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER; | |
517 | } | |
518 | break; | |
519 | case CT_DCCP_RESPOND: | |
520 | if (old_state == CT_DCCP_REQUEST) | |
521 | ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh); | |
522 | break; | |
523 | case CT_DCCP_PARTOPEN: | |
524 | if (old_state == CT_DCCP_RESPOND && | |
525 | type == DCCP_PKT_ACK && | |
526 | dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq) | |
527 | set_bit(IPS_ASSURED_BIT, &ct->status); | |
528 | break; | |
529 | case CT_DCCP_IGNORE: | |
530 | /* | |
531 | * Connection tracking might be out of sync, so we ignore | |
532 | * packets that might establish a new connection and resync | |
533 | * if the server responds with a valid Response. | |
534 | */ | |
535 | if (ct->proto.dccp.last_dir == !dir && | |
536 | ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST && | |
537 | type == DCCP_PKT_RESPONSE) { | |
538 | ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT; | |
539 | ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER; | |
540 | ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh); | |
541 | new_state = CT_DCCP_RESPOND; | |
542 | break; | |
543 | } | |
544 | ct->proto.dccp.last_dir = dir; | |
545 | ct->proto.dccp.last_pkt = type; | |
546 | ||
440f0d58 | 547 | spin_unlock_bh(&ct->lock); |
3d0b527b | 548 | nf_ct_l4proto_log_invalid(skb, ct, "%s", "invalid packet"); |
2bc78049 PM |
549 | return NF_ACCEPT; |
550 | case CT_DCCP_INVALID: | |
440f0d58 | 551 | spin_unlock_bh(&ct->lock); |
3d0b527b | 552 | nf_ct_l4proto_log_invalid(skb, ct, "%s", "invalid state transition"); |
2bc78049 PM |
553 | return -NF_ACCEPT; |
554 | } | |
555 | ||
556 | ct->proto.dccp.last_dir = dir; | |
557 | ct->proto.dccp.last_pkt = type; | |
558 | ct->proto.dccp.state = new_state; | |
440f0d58 | 559 | spin_unlock_bh(&ct->lock); |
1546000f | 560 | |
b38b1f61 PNA |
561 | if (new_state != old_state) |
562 | nf_conntrack_event_cache(IPCT_PROTOINFO, ct); | |
563 | ||
c779e849 FW |
564 | timeouts = nf_ct_timeout_lookup(ct); |
565 | if (!timeouts) | |
a95a7774 | 566 | timeouts = nf_dccp_pernet(nf_ct_net(ct))->dccp_timeout; |
2c8503f5 | 567 | nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]); |
2bc78049 PM |
568 | |
569 | return NF_ACCEPT; | |
570 | } | |
571 | ||
c6dd940b FW |
572 | static bool dccp_can_early_drop(const struct nf_conn *ct) |
573 | { | |
574 | switch (ct->proto.dccp.state) { | |
575 | case CT_DCCP_CLOSEREQ: | |
576 | case CT_DCCP_CLOSING: | |
577 | case CT_DCCP_TIMEWAIT: | |
578 | return true; | |
579 | default: | |
580 | break; | |
581 | } | |
582 | ||
583 | return false; | |
584 | } | |
585 | ||
ea48cc83 | 586 | #ifdef CONFIG_NF_CONNTRACK_PROCFS |
37246a58 | 587 | static void dccp_print_conntrack(struct seq_file *s, struct nf_conn *ct) |
2bc78049 | 588 | { |
37246a58 | 589 | seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]); |
2bc78049 | 590 | } |
ea48cc83 | 591 | #endif |
2bc78049 | 592 | |
c0cd1156 | 593 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
2bc78049 | 594 | static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla, |
440f0d58 | 595 | struct nf_conn *ct) |
2bc78049 PM |
596 | { |
597 | struct nlattr *nest_parms; | |
598 | ||
440f0d58 | 599 | spin_lock_bh(&ct->lock); |
2bc78049 PM |
600 | nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP | NLA_F_NESTED); |
601 | if (!nest_parms) | |
602 | goto nla_put_failure; | |
516ee48f DM |
603 | if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state) || |
604 | nla_put_u8(skb, CTA_PROTOINFO_DCCP_ROLE, | |
605 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]) || | |
606 | nla_put_be64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ, | |
b46f6ded ND |
607 | cpu_to_be64(ct->proto.dccp.handshake_seq), |
608 | CTA_PROTOINFO_DCCP_PAD)) | |
516ee48f | 609 | goto nla_put_failure; |
2bc78049 | 610 | nla_nest_end(skb, nest_parms); |
440f0d58 | 611 | spin_unlock_bh(&ct->lock); |
2bc78049 PM |
612 | return 0; |
613 | ||
614 | nla_put_failure: | |
440f0d58 | 615 | spin_unlock_bh(&ct->lock); |
2bc78049 PM |
616 | return -1; |
617 | } | |
618 | ||
619 | static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = { | |
620 | [CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 }, | |
71951b64 | 621 | [CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 }, |
a17c8598 | 622 | [CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 }, |
b46f6ded | 623 | [CTA_PROTOINFO_DCCP_PAD] = { .type = NLA_UNSPEC }, |
2bc78049 PM |
624 | }; |
625 | ||
39215846 FW |
626 | #define DCCP_NLATTR_SIZE ( \ |
627 | NLA_ALIGN(NLA_HDRLEN + 1) + \ | |
628 | NLA_ALIGN(NLA_HDRLEN + 1) + \ | |
629 | NLA_ALIGN(NLA_HDRLEN + sizeof(u64)) + \ | |
630 | NLA_ALIGN(NLA_HDRLEN + 0)) | |
631 | ||
2bc78049 PM |
632 | static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct) |
633 | { | |
634 | struct nlattr *attr = cda[CTA_PROTOINFO_DCCP]; | |
635 | struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1]; | |
636 | int err; | |
637 | ||
638 | if (!attr) | |
639 | return 0; | |
640 | ||
641 | err = nla_parse_nested(tb, CTA_PROTOINFO_DCCP_MAX, attr, | |
fceb6435 | 642 | dccp_nla_policy, NULL); |
2bc78049 PM |
643 | if (err < 0) |
644 | return err; | |
645 | ||
646 | if (!tb[CTA_PROTOINFO_DCCP_STATE] || | |
71951b64 PNA |
647 | !tb[CTA_PROTOINFO_DCCP_ROLE] || |
648 | nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX || | |
649 | nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) { | |
2bc78049 | 650 | return -EINVAL; |
71951b64 | 651 | } |
2bc78049 | 652 | |
440f0d58 | 653 | spin_lock_bh(&ct->lock); |
2bc78049 | 654 | ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]); |
71951b64 PNA |
655 | if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) { |
656 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT; | |
657 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER; | |
658 | } else { | |
659 | ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER; | |
660 | ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT; | |
661 | } | |
a17c8598 PNA |
662 | if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) { |
663 | ct->proto.dccp.handshake_seq = | |
664 | be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ])); | |
665 | } | |
440f0d58 | 666 | spin_unlock_bh(&ct->lock); |
2bc78049 PM |
667 | return 0; |
668 | } | |
669 | #endif | |
670 | ||
a874752a | 671 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
672 | |
673 | #include <linux/netfilter/nfnetlink.h> | |
674 | #include <linux/netfilter/nfnetlink_cttimeout.h> | |
675 | ||
8264deb8 G |
676 | static int dccp_timeout_nlattr_to_obj(struct nlattr *tb[], |
677 | struct net *net, void *data) | |
50978462 | 678 | { |
a95a7774 | 679 | struct nf_dccp_net *dn = nf_dccp_pernet(net); |
50978462 PNA |
680 | unsigned int *timeouts = data; |
681 | int i; | |
682 | ||
683 | /* set default DCCP timeouts. */ | |
684 | for (i=0; i<CT_DCCP_MAX; i++) | |
685 | timeouts[i] = dn->dccp_timeout[i]; | |
686 | ||
687 | /* there's a 1:1 mapping between attributes and protocol states. */ | |
688 | for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) { | |
689 | if (tb[i]) { | |
690 | timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ; | |
691 | } | |
692 | } | |
ef39078d FW |
693 | |
694 | timeouts[CTA_TIMEOUT_DCCP_UNSPEC] = timeouts[CTA_TIMEOUT_DCCP_REQUEST]; | |
50978462 PNA |
695 | return 0; |
696 | } | |
697 | ||
698 | static int | |
699 | dccp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) | |
700 | { | |
701 | const unsigned int *timeouts = data; | |
702 | int i; | |
703 | ||
516ee48f DM |
704 | for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) { |
705 | if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ))) | |
706 | goto nla_put_failure; | |
707 | } | |
50978462 PNA |
708 | return 0; |
709 | ||
710 | nla_put_failure: | |
711 | return -ENOSPC; | |
712 | } | |
713 | ||
714 | static const struct nla_policy | |
715 | dccp_timeout_nla_policy[CTA_TIMEOUT_DCCP_MAX+1] = { | |
716 | [CTA_TIMEOUT_DCCP_REQUEST] = { .type = NLA_U32 }, | |
717 | [CTA_TIMEOUT_DCCP_RESPOND] = { .type = NLA_U32 }, | |
718 | [CTA_TIMEOUT_DCCP_PARTOPEN] = { .type = NLA_U32 }, | |
719 | [CTA_TIMEOUT_DCCP_OPEN] = { .type = NLA_U32 }, | |
720 | [CTA_TIMEOUT_DCCP_CLOSEREQ] = { .type = NLA_U32 }, | |
721 | [CTA_TIMEOUT_DCCP_CLOSING] = { .type = NLA_U32 }, | |
722 | [CTA_TIMEOUT_DCCP_TIMEWAIT] = { .type = NLA_U32 }, | |
723 | }; | |
a874752a | 724 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
50978462 | 725 | |
2bc78049 | 726 | #ifdef CONFIG_SYSCTL |
1546000f CG |
727 | /* template, data assigned later */ |
728 | static struct ctl_table dccp_sysctl_table[] = { | |
2bc78049 | 729 | { |
2bc78049 | 730 | .procname = "nf_conntrack_dccp_timeout_request", |
2bc78049 PM |
731 | .maxlen = sizeof(unsigned int), |
732 | .mode = 0644, | |
733 | .proc_handler = proc_dointvec_jiffies, | |
734 | }, | |
735 | { | |
2bc78049 | 736 | .procname = "nf_conntrack_dccp_timeout_respond", |
2bc78049 PM |
737 | .maxlen = sizeof(unsigned int), |
738 | .mode = 0644, | |
739 | .proc_handler = proc_dointvec_jiffies, | |
740 | }, | |
741 | { | |
2bc78049 | 742 | .procname = "nf_conntrack_dccp_timeout_partopen", |
2bc78049 PM |
743 | .maxlen = sizeof(unsigned int), |
744 | .mode = 0644, | |
745 | .proc_handler = proc_dointvec_jiffies, | |
746 | }, | |
747 | { | |
2bc78049 | 748 | .procname = "nf_conntrack_dccp_timeout_open", |
2bc78049 PM |
749 | .maxlen = sizeof(unsigned int), |
750 | .mode = 0644, | |
751 | .proc_handler = proc_dointvec_jiffies, | |
752 | }, | |
753 | { | |
2bc78049 | 754 | .procname = "nf_conntrack_dccp_timeout_closereq", |
2bc78049 PM |
755 | .maxlen = sizeof(unsigned int), |
756 | .mode = 0644, | |
757 | .proc_handler = proc_dointvec_jiffies, | |
758 | }, | |
759 | { | |
2bc78049 | 760 | .procname = "nf_conntrack_dccp_timeout_closing", |
2bc78049 PM |
761 | .maxlen = sizeof(unsigned int), |
762 | .mode = 0644, | |
763 | .proc_handler = proc_dointvec_jiffies, | |
764 | }, | |
765 | { | |
2bc78049 | 766 | .procname = "nf_conntrack_dccp_timeout_timewait", |
2bc78049 PM |
767 | .maxlen = sizeof(unsigned int), |
768 | .mode = 0644, | |
769 | .proc_handler = proc_dointvec_jiffies, | |
770 | }, | |
771 | { | |
2bc78049 | 772 | .procname = "nf_conntrack_dccp_loose", |
1546000f | 773 | .maxlen = sizeof(int), |
2bc78049 PM |
774 | .mode = 0644, |
775 | .proc_handler = proc_dointvec, | |
776 | }, | |
f8572d8f | 777 | { } |
2bc78049 PM |
778 | }; |
779 | #endif /* CONFIG_SYSCTL */ | |
780 | ||
464dc801 | 781 | static int dccp_kmemdup_sysctl_table(struct net *net, struct nf_proto_net *pn, |
c51d3901 | 782 | struct nf_dccp_net *dn) |
54b8873f G |
783 | { |
784 | #ifdef CONFIG_SYSCTL | |
785 | if (pn->ctl_table) | |
786 | return 0; | |
787 | ||
788 | pn->ctl_table = kmemdup(dccp_sysctl_table, | |
789 | sizeof(dccp_sysctl_table), | |
790 | GFP_KERNEL); | |
791 | if (!pn->ctl_table) | |
792 | return -ENOMEM; | |
793 | ||
794 | pn->ctl_table[0].data = &dn->dccp_timeout[CT_DCCP_REQUEST]; | |
795 | pn->ctl_table[1].data = &dn->dccp_timeout[CT_DCCP_RESPOND]; | |
796 | pn->ctl_table[2].data = &dn->dccp_timeout[CT_DCCP_PARTOPEN]; | |
797 | pn->ctl_table[3].data = &dn->dccp_timeout[CT_DCCP_OPEN]; | |
798 | pn->ctl_table[4].data = &dn->dccp_timeout[CT_DCCP_CLOSEREQ]; | |
799 | pn->ctl_table[5].data = &dn->dccp_timeout[CT_DCCP_CLOSING]; | |
800 | pn->ctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT]; | |
801 | pn->ctl_table[7].data = &dn->dccp_loose; | |
464dc801 EB |
802 | |
803 | /* Don't export sysctls to unprivileged users */ | |
804 | if (net->user_ns != &init_user_ns) | |
805 | pn->ctl_table[0].procname = NULL; | |
54b8873f G |
806 | #endif |
807 | return 0; | |
808 | } | |
809 | ||
ca2ca6e1 | 810 | static int dccp_init_net(struct net *net) |
84c39451 | 811 | { |
a95a7774 | 812 | struct nf_dccp_net *dn = nf_dccp_pernet(net); |
54b8873f | 813 | struct nf_proto_net *pn = &dn->pn; |
84c39451 | 814 | |
54b8873f | 815 | if (!pn->users) { |
84c39451 G |
816 | /* default values */ |
817 | dn->dccp_loose = 1; | |
818 | dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL; | |
819 | dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL; | |
820 | dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL; | |
821 | dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ; | |
822 | dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ; | |
823 | dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ; | |
824 | dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL; | |
ef39078d FW |
825 | |
826 | /* timeouts[0] is unused, make it same as SYN_SENT so | |
827 | * ->timeouts[0] contains 'new' timeout, like udp or icmp. | |
828 | */ | |
829 | dn->dccp_timeout[CT_DCCP_NONE] = dn->dccp_timeout[CT_DCCP_REQUEST]; | |
84c39451 | 830 | } |
54b8873f | 831 | |
464dc801 | 832 | return dccp_kmemdup_sysctl_table(net, pn, dn); |
84c39451 G |
833 | } |
834 | ||
deaa0a97 LZ |
835 | static struct nf_proto_net *dccp_get_net_proto(struct net *net) |
836 | { | |
837 | return &net->ct.nf_ct_proto.dccp.pn; | |
838 | } | |
839 | ||
dd2934a9 | 840 | const struct nf_conntrack_l4proto nf_conntrack_l4proto_dccp = { |
2bc78049 | 841 | .l4proto = IPPROTO_DCCP, |
2bc78049 | 842 | .packet = dccp_packet, |
c6dd940b | 843 | .can_early_drop = dccp_can_early_drop, |
ea48cc83 | 844 | #ifdef CONFIG_NF_CONNTRACK_PROCFS |
2bc78049 | 845 | .print_conntrack = dccp_print_conntrack, |
ea48cc83 | 846 | #endif |
c0cd1156 | 847 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
39215846 | 848 | .nlattr_size = DCCP_NLATTR_SIZE, |
2bc78049 PM |
849 | .to_nlattr = dccp_to_nlattr, |
850 | .from_nlattr = nlattr_to_dccp, | |
851 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, | |
a400c30e | 852 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
2bc78049 PM |
853 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
854 | .nla_policy = nf_ct_port_nla_policy, | |
855 | #endif | |
a874752a | 856 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
50978462 PNA |
857 | .ctnl_timeout = { |
858 | .nlattr_to_obj = dccp_timeout_nlattr_to_obj, | |
859 | .obj_to_nlattr = dccp_timeout_obj_to_nlattr, | |
860 | .nlattr_max = CTA_TIMEOUT_DCCP_MAX, | |
861 | .obj_size = sizeof(unsigned int) * CT_DCCP_MAX, | |
862 | .nla_policy = dccp_timeout_nla_policy, | |
863 | }, | |
a874752a | 864 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
84c39451 | 865 | .init_net = dccp_init_net, |
deaa0a97 | 866 | .get_net_proto = dccp_get_net_proto, |
2bc78049 | 867 | }; |