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Merge remote-tracking branch 'spi/for-next'
[deliverable/linux.git] / net / netfilter / nf_conntrack_proto_dccp.c
CommitLineData
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>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/sysctl.h>
15#include <linux/spinlock.h>
16#include <linux/skbuff.h>
17#include <linux/dccp.h>
5a0e3ad6 18#include <linux/slab.h>
2bc78049 19
1546000f
CG		 20#include <net/net_namespace.h>
21#include <net/netns/generic.h>
22
2bc78049
PM		 23#include <linux/netfilter/nfnetlink_conntrack.h>
24#include <net/netfilter/nf_conntrack.h>
25#include <net/netfilter/nf_conntrack_l4proto.h>
b38b1f61 26#include <net/netfilter/nf_conntrack_ecache.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		 76static 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 */
132static const u_int8_t
133dccp_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 */
247 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
248 },
249 [DCCP_PKT_SYNCACK] = {
250 /*
251 * We currently ignore SyncAck packets
252 *
253 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
254 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
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 */
375 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
376 },
377 [DCCP_PKT_SYNCACK] = {
378 /*
379 * We currently ignore SyncAck packets
380 *
381 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
382 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
383 },
384 },
385};
386
1546000f 387/* this module per-net specifics */
f99189b1 388static int dccp_net_id __read_mostly;
1546000f 389struct dccp_net {
54b8873f 390 struct nf_proto_net pn;
1546000f
CG		 391 int dccp_loose;
392 unsigned int dccp_timeout[CT_DCCP_MAX + 1];
1546000f
CG		 393};
394
395static inline struct dccp_net *dccp_pernet(struct net *net)
396{
397 return net_generic(net, dccp_net_id);
398}
399
09f263cd 400static bool dccp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
a31f1adc 401 struct net *net, struct nf_conntrack_tuple *tuple)
2bc78049
PM		 402{
403 struct dccp_hdr _hdr, *dh;
404
e5e693ab
GF		 405 /* Actually only need first 4 bytes to get ports. */
406 dh = skb_header_pointer(skb, dataoff, 4, &_hdr);
2bc78049 407 if (dh == NULL)
09f263cd 408 return false;
2bc78049
PM		 409
410 tuple->src.u.dccp.port = dh->dccph_sport;
411 tuple->dst.u.dccp.port = dh->dccph_dport;
09f263cd 412 return true;
2bc78049
PM		 413}
414
09f263cd
JE		 415static bool dccp_invert_tuple(struct nf_conntrack_tuple *inv,
416 const struct nf_conntrack_tuple *tuple)
2bc78049
PM		 417{
418 inv->src.u.dccp.port = tuple->dst.u.dccp.port;
419 inv->dst.u.dccp.port = tuple->src.u.dccp.port;
09f263cd 420 return true;
2bc78049
PM		 421}
422
09f263cd 423static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb,
2c8503f5 424 unsigned int dataoff, unsigned int *timeouts)
2bc78049 425{
c2a2c7e0 426 struct net *net = nf_ct_net(ct);
1546000f 427 struct dccp_net *dn;
2bc78049
PM		 428 struct dccp_hdr _dh, *dh;
429 const char *msg;
430 u_int8_t state;
431
b22f5126 432 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
2bc78049
PM		 433 BUG_ON(dh == NULL);
434
435 state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE];
436 switch (state) {
437 default:
1546000f
CG		 438 dn = dccp_pernet(net);
439 if (dn->dccp_loose == 0) {
2bc78049
PM		 440 msg = "nf_ct_dccp: not picking up existing connection ";
441 goto out_invalid;
442 }
443 case CT_DCCP_REQUEST:
444 break;
445 case CT_DCCP_INVALID:
446 msg = "nf_ct_dccp: invalid state transition ";
447 goto out_invalid;
448 }
449
450 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
451 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
452 ct->proto.dccp.state = CT_DCCP_NONE;
e5fc9e7a
CG		 453 ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST;
454 ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL;
455 ct->proto.dccp.handshake_seq = 0;
09f263cd 456 return true;
2bc78049
PM		 457
458out_invalid:
c2a2c7e0 459 if (LOG_INVALID(net, IPPROTO_DCCP))
30e0c6a6 460 nf_log_packet(net, nf_ct_l3num(ct), 0, skb, NULL, NULL,
138aef7d 461 NULL, "%s", msg);
09f263cd 462 return false;
2bc78049
PM		 463}
464
465static u64 dccp_ack_seq(const struct dccp_hdr *dh)
466{
467 const struct dccp_hdr_ack_bits *dhack;
468
469 dhack = (void *)dh + __dccp_basic_hdr_len(dh);
470 return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) +
471 ntohl(dhack->dccph_ack_nr_low);
472}
473
2c8503f5
PNA		 474static unsigned int *dccp_get_timeouts(struct net *net)
475{
476 return dccp_pernet(net)->dccp_timeout;
477}
478
2bc78049
PM		 479static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb,
480 unsigned int dataoff, enum ip_conntrack_info ctinfo,
2c8503f5
PNA		 481 u_int8_t pf, unsigned int hooknum,
482 unsigned int *timeouts)
2bc78049 483{
c2a2c7e0 484 struct net *net = nf_ct_net(ct);
2bc78049
PM		 485 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
486 struct dccp_hdr _dh, *dh;
487 u_int8_t type, old_state, new_state;
488 enum ct_dccp_roles role;
489
b22f5126 490 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
2bc78049
PM		 491 BUG_ON(dh == NULL);
492 type = dh->dccph_type;
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);
c2a2c7e0 546 if (LOG_INVALID(net, IPPROTO_DCCP))
30e0c6a6 547 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
2bc78049
PM		 548 "nf_ct_dccp: invalid packet ignored ");
549 return NF_ACCEPT;
550 case CT_DCCP_INVALID:
440f0d58 551 spin_unlock_bh(&ct->lock);
c2a2c7e0 552 if (LOG_INVALID(net, IPPROTO_DCCP))
30e0c6a6 553 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
2bc78049
PM		 554 "nf_ct_dccp: invalid state transition ");
555 return -NF_ACCEPT;
556 }
557
558 ct->proto.dccp.last_dir = dir;
559 ct->proto.dccp.last_pkt = type;
560 ct->proto.dccp.state = new_state;
440f0d58 561 spin_unlock_bh(&ct->lock);
1546000f 562
b38b1f61
PNA		 563 if (new_state != old_state)
564 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
565
2c8503f5 566 nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
2bc78049
PM		 567
568 return NF_ACCEPT;
569}
570
8fea97ec
PM		 571static int dccp_error(struct net *net, struct nf_conn *tmpl,
572 struct sk_buff *skb, unsigned int dataoff,
573 enum ip_conntrack_info *ctinfo,
74c51a14 574 u_int8_t pf, unsigned int hooknum)
2bc78049
PM		 575{
576 struct dccp_hdr _dh, *dh;
577 unsigned int dccp_len = skb->len - dataoff;
578 unsigned int cscov;
579 const char *msg;
580
b22f5126 581 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
2bc78049
PM		 582 if (dh == NULL) {
583 msg = "nf_ct_dccp: short packet ";
584 goto out_invalid;
585 }
586
587 if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
588 dh->dccph_doff * 4 > dccp_len) {
589 msg = "nf_ct_dccp: truncated/malformed packet ";
590 goto out_invalid;
591 }
592
593 cscov = dccp_len;
594 if (dh->dccph_cscov) {
595 cscov = (dh->dccph_cscov - 1) * 4;
596 if (cscov > dccp_len) {
597 msg = "nf_ct_dccp: bad checksum coverage ";
598 goto out_invalid;
599 }
600 }
601
c04d0552 602 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
2bc78049
PM		 603 nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_DCCP,
604 pf)) {
605 msg = "nf_ct_dccp: bad checksum ";
606 goto out_invalid;
607 }
608
609 if (dh->dccph_type >= DCCP_PKT_INVALID) {
610 msg = "nf_ct_dccp: reserved packet type ";
611 goto out_invalid;
612 }
613
614 return NF_ACCEPT;
615
616out_invalid:
c2a2c7e0 617 if (LOG_INVALID(net, IPPROTO_DCCP))
138aef7d 618 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "%s", msg);
2bc78049
PM		 619 return -NF_ACCEPT;
620}
621
824f1fbe
JP		 622static void dccp_print_tuple(struct seq_file *s,
623 const struct nf_conntrack_tuple *tuple)
2bc78049 624{
824f1fbe
JP		 625 seq_printf(s, "sport=%hu dport=%hu ",
626 ntohs(tuple->src.u.dccp.port),
627 ntohs(tuple->dst.u.dccp.port));
2bc78049
PM		 628}
629
37246a58 630static void dccp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
2bc78049 631{
37246a58 632 seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]);
2bc78049
PM		 633}
634
c0cd1156 635#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
2bc78049 636static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
440f0d58 637 struct nf_conn *ct)
2bc78049
PM		 638{
639 struct nlattr *nest_parms;
640
440f0d58 641 spin_lock_bh(&ct->lock);
2bc78049
PM		 642 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP | NLA_F_NESTED);
643 if (!nest_parms)
644 goto nla_put_failure;
516ee48f
DM		 645 if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state) ||
646 nla_put_u8(skb, CTA_PROTOINFO_DCCP_ROLE,
647 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]) ||
648 nla_put_be64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ,
b46f6ded
ND		 649 cpu_to_be64(ct->proto.dccp.handshake_seq),
650 CTA_PROTOINFO_DCCP_PAD))
516ee48f 651 goto nla_put_failure;
2bc78049 652 nla_nest_end(skb, nest_parms);
440f0d58 653 spin_unlock_bh(&ct->lock);
2bc78049
PM		 654 return 0;
655
656nla_put_failure:
440f0d58 657 spin_unlock_bh(&ct->lock);
2bc78049
PM		 658 return -1;
659}
660
661static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
662 [CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 },
71951b64 663 [CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 },
a17c8598 664 [CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 },
b46f6ded 665 [CTA_PROTOINFO_DCCP_PAD] = { .type = NLA_UNSPEC },
2bc78049
PM		 666};
667
668static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
669{
670 struct nlattr *attr = cda[CTA_PROTOINFO_DCCP];
671 struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1];
672 int err;
673
674 if (!attr)
675 return 0;
676
677 err = nla_parse_nested(tb, CTA_PROTOINFO_DCCP_MAX, attr,
678 dccp_nla_policy);
679 if (err < 0)
680 return err;
681
682 if (!tb[CTA_PROTOINFO_DCCP_STATE] ||
71951b64
PNA		 683 !tb[CTA_PROTOINFO_DCCP_ROLE] ||
684 nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX ||
685 nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) {
2bc78049 686 return -EINVAL;
71951b64 687 }
2bc78049 688
440f0d58 689 spin_lock_bh(&ct->lock);
2bc78049 690 ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]);
71951b64
PNA		 691 if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) {
692 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
693 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
694 } else {
695 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
696 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
697 }
a17c8598
PNA		 698 if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) {
699 ct->proto.dccp.handshake_seq =
700 be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]));
701 }
440f0d58 702 spin_unlock_bh(&ct->lock);
2bc78049
PM		 703 return 0;
704}
a400c30e
HE		 705
706static int dccp_nlattr_size(void)
707{
708 return nla_total_size(0) /* CTA_PROTOINFO_DCCP */
709 + nla_policy_len(dccp_nla_policy, CTA_PROTOINFO_DCCP_MAX + 1);
710}
50978462 711
2bc78049
PM		 712#endif
713
50978462
PNA		 714#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
715
716#include <linux/netfilter/nfnetlink.h>
717#include <linux/netfilter/nfnetlink_cttimeout.h>
718
8264deb8
G		 719static int dccp_timeout_nlattr_to_obj(struct nlattr *tb[],
720 struct net *net, void *data)
50978462 721{
8264deb8 722 struct dccp_net *dn = dccp_pernet(net);
50978462
PNA		 723 unsigned int *timeouts = data;
724 int i;
725
726 /* set default DCCP timeouts. */
727 for (i=0; i<CT_DCCP_MAX; i++)
728 timeouts[i] = dn->dccp_timeout[i];
729
730 /* there's a 1:1 mapping between attributes and protocol states. */
731 for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
732 if (tb[i]) {
733 timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
734 }
735 }
736 return 0;
737}
738
739static int
740dccp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
741{
742 const unsigned int *timeouts = data;
743 int i;
744
516ee48f
DM		 745 for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
746 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
747 goto nla_put_failure;
748 }
50978462
PNA		 749 return 0;
750
751nla_put_failure:
752 return -ENOSPC;
753}
754
755static const struct nla_policy
756dccp_timeout_nla_policy[CTA_TIMEOUT_DCCP_MAX+1] = {
757 [CTA_TIMEOUT_DCCP_REQUEST] = { .type = NLA_U32 },
758 [CTA_TIMEOUT_DCCP_RESPOND] = { .type = NLA_U32 },
759 [CTA_TIMEOUT_DCCP_PARTOPEN] = { .type = NLA_U32 },
760 [CTA_TIMEOUT_DCCP_OPEN] = { .type = NLA_U32 },
761 [CTA_TIMEOUT_DCCP_CLOSEREQ] = { .type = NLA_U32 },
762 [CTA_TIMEOUT_DCCP_CLOSING] = { .type = NLA_U32 },
763 [CTA_TIMEOUT_DCCP_TIMEWAIT] = { .type = NLA_U32 },
764};
765#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
766
2bc78049 767#ifdef CONFIG_SYSCTL
1546000f
CG		 768/* template, data assigned later */
769static struct ctl_table dccp_sysctl_table[] = {
2bc78049 770 {
2bc78049 771 .procname = "nf_conntrack_dccp_timeout_request",
2bc78049
PM		 772 .maxlen = sizeof(unsigned int),
773 .mode = 0644,
774 .proc_handler = proc_dointvec_jiffies,
775 },
776 {
2bc78049 777 .procname = "nf_conntrack_dccp_timeout_respond",
2bc78049
PM		 778 .maxlen = sizeof(unsigned int),
779 .mode = 0644,
780 .proc_handler = proc_dointvec_jiffies,
781 },
782 {
2bc78049 783 .procname = "nf_conntrack_dccp_timeout_partopen",
2bc78049
PM		 784 .maxlen = sizeof(unsigned int),
785 .mode = 0644,
786 .proc_handler = proc_dointvec_jiffies,
787 },
788 {
2bc78049 789 .procname = "nf_conntrack_dccp_timeout_open",
2bc78049
PM		 790 .maxlen = sizeof(unsigned int),
791 .mode = 0644,
792 .proc_handler = proc_dointvec_jiffies,
793 },
794 {
2bc78049 795 .procname = "nf_conntrack_dccp_timeout_closereq",
2bc78049
PM		 796 .maxlen = sizeof(unsigned int),
797 .mode = 0644,
798 .proc_handler = proc_dointvec_jiffies,
799 },
800 {
2bc78049 801 .procname = "nf_conntrack_dccp_timeout_closing",
2bc78049
PM		 802 .maxlen = sizeof(unsigned int),
803 .mode = 0644,
804 .proc_handler = proc_dointvec_jiffies,
805 },
806 {
2bc78049 807 .procname = "nf_conntrack_dccp_timeout_timewait",
2bc78049
PM		 808 .maxlen = sizeof(unsigned int),
809 .mode = 0644,
810 .proc_handler = proc_dointvec_jiffies,
811 },
812 {
2bc78049 813 .procname = "nf_conntrack_dccp_loose",
1546000f 814 .maxlen = sizeof(int),
2bc78049
PM		 815 .mode = 0644,
816 .proc_handler = proc_dointvec,
817 },
f8572d8f 818 { }
2bc78049
PM		 819};
820#endif /* CONFIG_SYSCTL */
821
464dc801 822static int dccp_kmemdup_sysctl_table(struct net *net, struct nf_proto_net *pn,
54b8873f
G		 823 struct dccp_net *dn)
824{
825#ifdef CONFIG_SYSCTL
826 if (pn->ctl_table)
827 return 0;
828
829 pn->ctl_table = kmemdup(dccp_sysctl_table,
830 sizeof(dccp_sysctl_table),
831 GFP_KERNEL);
832 if (!pn->ctl_table)
833 return -ENOMEM;
834
835 pn->ctl_table[0].data = &dn->dccp_timeout[CT_DCCP_REQUEST];
836 pn->ctl_table[1].data = &dn->dccp_timeout[CT_DCCP_RESPOND];
837 pn->ctl_table[2].data = &dn->dccp_timeout[CT_DCCP_PARTOPEN];
838 pn->ctl_table[3].data = &dn->dccp_timeout[CT_DCCP_OPEN];
839 pn->ctl_table[4].data = &dn->dccp_timeout[CT_DCCP_CLOSEREQ];
840 pn->ctl_table[5].data = &dn->dccp_timeout[CT_DCCP_CLOSING];
841 pn->ctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT];
842 pn->ctl_table[7].data = &dn->dccp_loose;
464dc801
EB		 843
844 /* Don't export sysctls to unprivileged users */
845 if (net->user_ns != &init_user_ns)
846 pn->ctl_table[0].procname = NULL;
54b8873f
G		 847#endif
848 return 0;
849}
850
f1caad27 851static int dccp_init_net(struct net *net, u_int16_t proto)
84c39451
G		 852{
853 struct dccp_net *dn = dccp_pernet(net);
54b8873f 854 struct nf_proto_net *pn = &dn->pn;
84c39451 855
54b8873f 856 if (!pn->users) {
84c39451
G		 857 /* default values */
858 dn->dccp_loose = 1;
859 dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL;
860 dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL;
861 dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL;
862 dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ;
863 dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ;
864 dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ;
865 dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL;
84c39451 866 }
54b8873f 867
464dc801 868 return dccp_kmemdup_sysctl_table(net, pn, dn);
84c39451
G		 869}
870
2bc78049
PM		 871static struct nf_conntrack_l4proto dccp_proto4 __read_mostly = {
872 .l3proto = AF_INET,
873 .l4proto = IPPROTO_DCCP,
874 .name = "dccp",
875 .pkt_to_tuple = dccp_pkt_to_tuple,
876 .invert_tuple = dccp_invert_tuple,
877 .new = dccp_new,
878 .packet = dccp_packet,
2c8503f5 879 .get_timeouts = dccp_get_timeouts,
2bc78049
PM		 880 .error = dccp_error,
881 .print_tuple = dccp_print_tuple,
882 .print_conntrack = dccp_print_conntrack,
c0cd1156 883#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
2bc78049 884 .to_nlattr = dccp_to_nlattr,
a400c30e 885 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 886 .from_nlattr = nlattr_to_dccp,
887 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 888 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 889 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
890 .nla_policy = nf_ct_port_nla_policy,
891#endif
50978462
PNA		 892#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
893 .ctnl_timeout = {
894 .nlattr_to_obj = dccp_timeout_nlattr_to_obj,
895 .obj_to_nlattr = dccp_timeout_obj_to_nlattr,
896 .nlattr_max = CTA_TIMEOUT_DCCP_MAX,
897 .obj_size = sizeof(unsigned int) * CT_DCCP_MAX,
898 .nla_policy = dccp_timeout_nla_policy,
899 },
900#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
84c39451
G		 901 .net_id = &dccp_net_id,
902 .init_net = dccp_init_net,
2bc78049
PM		 903};
904
905static struct nf_conntrack_l4proto dccp_proto6 __read_mostly = {
906 .l3proto = AF_INET6,
907 .l4proto = IPPROTO_DCCP,
908 .name = "dccp",
909 .pkt_to_tuple = dccp_pkt_to_tuple,
910 .invert_tuple = dccp_invert_tuple,
911 .new = dccp_new,
912 .packet = dccp_packet,
2c8503f5 913 .get_timeouts = dccp_get_timeouts,
2bc78049
PM		 914 .error = dccp_error,
915 .print_tuple = dccp_print_tuple,
916 .print_conntrack = dccp_print_conntrack,
c0cd1156 917#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
2bc78049 918 .to_nlattr = dccp_to_nlattr,
5ff48294 919 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 920 .from_nlattr = nlattr_to_dccp,
921 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 922 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 923 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
924 .nla_policy = nf_ct_port_nla_policy,
925#endif
50978462
PNA		 926#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
927 .ctnl_timeout = {
928 .nlattr_to_obj = dccp_timeout_nlattr_to_obj,
929 .obj_to_nlattr = dccp_timeout_obj_to_nlattr,
930 .nlattr_max = CTA_TIMEOUT_DCCP_MAX,
931 .obj_size = sizeof(unsigned int) * CT_DCCP_MAX,
932 .nla_policy = dccp_timeout_nla_policy,
933 },
934#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
84c39451
G		 935 .net_id = &dccp_net_id,
936 .init_net = dccp_init_net,
1546000f
CG		 937};
938
939static __net_init int dccp_net_init(struct net *net)
940{
84c39451 941 int ret = 0;
c296bb4d 942 ret = nf_ct_l4proto_pernet_register(net, &dccp_proto4);
84c39451 943 if (ret < 0) {
c296bb4d 944 pr_err("nf_conntrack_dccp4: pernet registration failed.\n");
84c39451
G		 945 goto out;
946 }
c296bb4d 947 ret = nf_ct_l4proto_pernet_register(net, &dccp_proto6);
84c39451 948 if (ret < 0) {
c296bb4d 949 pr_err("nf_conntrack_dccp6: pernet registration failed.\n");
84c39451 950 goto cleanup_dccp4;
1546000f 951 }
1546000f 952 return 0;
84c39451 953cleanup_dccp4:
c296bb4d 954 nf_ct_l4proto_pernet_unregister(net, &dccp_proto4);
84c39451
G		 955out:
956 return ret;
1546000f
CG		 957}
958
959static __net_exit void dccp_net_exit(struct net *net)
960{
c296bb4d
G		 961 nf_ct_l4proto_pernet_unregister(net, &dccp_proto6);
962 nf_ct_l4proto_pernet_unregister(net, &dccp_proto4);
1546000f
CG		 963}
964
965static struct pernet_operations dccp_net_ops = {
966 .init = dccp_net_init,
967 .exit = dccp_net_exit,
32b51f92
EB		 968 .id = &dccp_net_id,
969 .size = sizeof(struct dccp_net),
2bc78049
PM		 970};
971
972static int __init nf_conntrack_proto_dccp_init(void)
973{
c296bb4d
G		 974 int ret;
975
0d98da5d
G		 976 ret = register_pernet_subsys(&dccp_net_ops);
977 if (ret < 0)
978 goto out_pernet;
979
c296bb4d
G		 980 ret = nf_ct_l4proto_register(&dccp_proto4);
981 if (ret < 0)
982 goto out_dccp4;
983
984 ret = nf_ct_l4proto_register(&dccp_proto6);
985 if (ret < 0)
986 goto out_dccp6;
987
c296bb4d 988 return 0;
c296bb4d
G		 989out_dccp6:
990 nf_ct_l4proto_unregister(&dccp_proto4);
991out_dccp4:
0d98da5d
G		 992 unregister_pernet_subsys(&dccp_net_ops);
993out_pernet:
c296bb4d 994 return ret;
2bc78049
PM		 995}
996
997static void __exit nf_conntrack_proto_dccp_fini(void)
998{
c296bb4d
G		 999 nf_ct_l4proto_unregister(&dccp_proto6);
1000 nf_ct_l4proto_unregister(&dccp_proto4);
32b51f92 1001 unregister_pernet_subsys(&dccp_net_ops);
2bc78049
PM		 1002}
1003
1004module_init(nf_conntrack_proto_dccp_init);
1005module_exit(nf_conntrack_proto_dccp_fini);
1006
1007MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
1008MODULE_DESCRIPTION("DCCP connection tracking protocol helper");
1009MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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