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Merge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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>
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>
2bc78049
PM		 26#include <net/netfilter/nf_log.h>
27
28static DEFINE_RWLOCK(dccp_lock);
29
2bc78049
PM		 30/* Timeouts are based on values from RFC4340:
31 *
32 * - REQUEST:
33 *
34 * 8.1.2. Client Request
35 *
36 * A client MAY give up on its DCCP-Requests after some time
37 * (3 minutes, for example).
38 *
39 * - RESPOND:
40 *
41 * 8.1.3. Server Response
42 *
43 * It MAY also leave the RESPOND state for CLOSED after a timeout of
44 * not less than 4MSL (8 minutes);
45 *
46 * - PARTOPEN:
47 *
48 * 8.1.5. Handshake Completion
49 *
50 * If the client remains in PARTOPEN for more than 4MSL (8 minutes),
51 * it SHOULD reset the connection with Reset Code 2, "Aborted".
52 *
53 * - OPEN:
54 *
55 * The DCCP timestamp overflows after 11.9 hours. If the connection
56 * stays idle this long the sequence number won't be recognized
57 * as valid anymore.
58 *
59 * - CLOSEREQ/CLOSING:
60 *
61 * 8.3. Termination
62 *
63 * The retransmission timer should initially be set to go off in two
64 * round-trip times and should back off to not less than once every
65 * 64 seconds ...
66 *
67 * - TIMEWAIT:
68 *
69 * 4.3. States
70 *
71 * A server or client socket remains in this state for 2MSL (4 minutes)
72 * after the connection has been town down, ...
73 */
74
75#define DCCP_MSL (2 * 60 * HZ)
76
2bc78049
PM		 77static const char * const dccp_state_names[] = {
78 [CT_DCCP_NONE] = "NONE",
79 [CT_DCCP_REQUEST] = "REQUEST",
80 [CT_DCCP_RESPOND] = "RESPOND",
81 [CT_DCCP_PARTOPEN] = "PARTOPEN",
82 [CT_DCCP_OPEN] = "OPEN",
83 [CT_DCCP_CLOSEREQ] = "CLOSEREQ",
84 [CT_DCCP_CLOSING] = "CLOSING",
85 [CT_DCCP_TIMEWAIT] = "TIMEWAIT",
86 [CT_DCCP_IGNORE] = "IGNORE",
87 [CT_DCCP_INVALID] = "INVALID",
88};
89
90#define sNO CT_DCCP_NONE
91#define sRQ CT_DCCP_REQUEST
92#define sRS CT_DCCP_RESPOND
93#define sPO CT_DCCP_PARTOPEN
94#define sOP CT_DCCP_OPEN
95#define sCR CT_DCCP_CLOSEREQ
96#define sCG CT_DCCP_CLOSING
97#define sTW CT_DCCP_TIMEWAIT
98#define sIG CT_DCCP_IGNORE
99#define sIV CT_DCCP_INVALID
100
101/*
102 * DCCP state transistion table
103 *
104 * The assumption is the same as for TCP tracking:
105 *
106 * We are the man in the middle. All the packets go through us but might
107 * get lost in transit to the destination. It is assumed that the destination
108 * can't receive segments we haven't seen.
109 *
110 * The following states exist:
111 *
112 * NONE: Initial state, expecting Request
113 * REQUEST: Request seen, waiting for Response from server
114 * RESPOND: Response from server seen, waiting for Ack from client
115 * PARTOPEN: Ack after Response seen, waiting for packet other than Response,
116 * Reset or Sync from server
117 * OPEN: Packet other than Response, Reset or Sync seen
118 * CLOSEREQ: CloseReq from server seen, expecting Close from client
119 * CLOSING: Close seen, expecting Reset
120 * TIMEWAIT: Reset seen
121 * IGNORE: Not determinable whether packet is valid
122 *
123 * Some states exist only on one side of the connection: REQUEST, RESPOND,
124 * PARTOPEN, CLOSEREQ. For the other side these states are equivalent to
125 * the one it was in before.
126 *
127 * Packets are marked as ignored (sIG) if we don't know if they're valid
128 * (for example a reincarnation of a connection we didn't notice is dead
129 * already) and the server may send back a connection closing Reset or a
130 * Response. They're also used for Sync/SyncAck packets, which we don't
131 * care about.
132 */
133static const u_int8_t
134dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] = {
135 [CT_DCCP_ROLE_CLIENT] = {
136 [DCCP_PKT_REQUEST] = {
137 /*
138 * sNO -> sRQ Regular Request
139 * sRQ -> sRQ Retransmitted Request or reincarnation
140 * sRS -> sRS Retransmitted Request (apparently Response
141 * got lost after we saw it) or reincarnation
142 * sPO -> sIG Ignore, conntrack might be out of sync
143 * sOP -> sIG Ignore, conntrack might be out of sync
144 * sCR -> sIG Ignore, conntrack might be out of sync
145 * sCG -> sIG Ignore, conntrack might be out of sync
146 * sTW -> sRQ Reincarnation
147 *
148 * sNO, sRQ, sRS, sPO. sOP, sCR, sCG, sTW, */
149 sRQ, sRQ, sRS, sIG, sIG, sIG, sIG, sRQ,
150 },
151 [DCCP_PKT_RESPONSE] = {
152 /*
153 * sNO -> sIV Invalid
154 * sRQ -> sIG Ignore, might be response to ignored Request
155 * sRS -> sIG Ignore, might be response to ignored Request
156 * sPO -> sIG Ignore, might be response to ignored Request
157 * sOP -> sIG Ignore, might be response to ignored Request
158 * sCR -> sIG Ignore, might be response to ignored Request
159 * sCG -> sIG Ignore, might be response to ignored Request
160 * sTW -> sIV Invalid, reincarnation in reverse direction
161 * goes through sRQ
162 *
163 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
164 sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIV,
165 },
166 [DCCP_PKT_ACK] = {
167 /*
168 * sNO -> sIV No connection
169 * sRQ -> sIV No connection
170 * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.)
171 * sPO -> sPO Retransmitted Ack for Response, remain in PARTOPEN
172 * sOP -> sOP Regular ACK, remain in OPEN
173 * sCR -> sCR Ack in CLOSEREQ MAY be processed (8.3.)
174 * sCG -> sCG Ack in CLOSING MAY be processed (8.3.)
175 * sTW -> sIV
176 *
177 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
178 sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
179 },
180 [DCCP_PKT_DATA] = {
181 /*
182 * sNO -> sIV No connection
183 * sRQ -> sIV No connection
184 * sRS -> sIV No connection
185 * sPO -> sIV MUST use DataAck in PARTOPEN state (8.1.5.)
186 * sOP -> sOP Regular Data packet
187 * sCR -> sCR Data in CLOSEREQ MAY be processed (8.3.)
188 * sCG -> sCG Data in CLOSING MAY be processed (8.3.)
189 * sTW -> sIV
190 *
191 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
192 sIV, sIV, sIV, sIV, sOP, sCR, sCG, sIV,
193 },
194 [DCCP_PKT_DATAACK] = {
195 /*
196 * sNO -> sIV No connection
197 * sRQ -> sIV No connection
198 * sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.)
199 * sPO -> sPO Remain in PARTOPEN state
200 * sOP -> sOP Regular DataAck packet in OPEN state
201 * sCR -> sCR DataAck in CLOSEREQ MAY be processed (8.3.)
202 * sCG -> sCG DataAck in CLOSING MAY be processed (8.3.)
203 * sTW -> sIV
204 *
205 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
206 sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
207 },
208 [DCCP_PKT_CLOSEREQ] = {
209 /*
210 * CLOSEREQ may only be sent by the server.
211 *
212 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
213 sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV
214 },
215 [DCCP_PKT_CLOSE] = {
216 /*
217 * sNO -> sIV No connection
218 * sRQ -> sIV No connection
219 * sRS -> sIV No connection
220 * sPO -> sCG Client-initiated close
221 * sOP -> sCG Client-initiated close
222 * sCR -> sCG Close in response to CloseReq (8.3.)
223 * sCG -> sCG Retransmit
224 * sTW -> sIV Late retransmit, already in TIME_WAIT
225 *
226 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
227 sIV, sIV, sIV, sCG, sCG, sCG, sIV, sIV
228 },
229 [DCCP_PKT_RESET] = {
230 /*
231 * sNO -> sIV No connection
232 * sRQ -> sTW Sync received or timeout, SHOULD send Reset (8.1.1.)
233 * sRS -> sTW Response received without Request
234 * sPO -> sTW Timeout, SHOULD send Reset (8.1.5.)
235 * sOP -> sTW Connection reset
236 * sCR -> sTW Connection reset
237 * sCG -> sTW Connection reset
238 * sTW -> sIG Ignore (don't refresh timer)
239 *
240 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
241 sIV, sTW, sTW, sTW, sTW, sTW, sTW, sIG
242 },
243 [DCCP_PKT_SYNC] = {
244 /*
245 * We currently ignore Sync packets
246 *
247 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
248 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
249 },
250 [DCCP_PKT_SYNCACK] = {
251 /*
252 * We currently ignore SyncAck packets
253 *
254 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
255 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
256 },
257 },
258 [CT_DCCP_ROLE_SERVER] = {
259 [DCCP_PKT_REQUEST] = {
260 /*
261 * sNO -> sIV Invalid
262 * sRQ -> sIG Ignore, conntrack might be out of sync
263 * sRS -> sIG Ignore, conntrack might be out of sync
264 * sPO -> sIG Ignore, conntrack might be out of sync
265 * sOP -> sIG Ignore, conntrack might be out of sync
266 * sCR -> sIG Ignore, conntrack might be out of sync
267 * sCG -> sIG Ignore, conntrack might be out of sync
268 * sTW -> sRQ Reincarnation, must reverse roles
269 *
270 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
271 sIV, sIG, sIG, sIG, sIG, sIG, sIG, sRQ
272 },
273 [DCCP_PKT_RESPONSE] = {
274 /*
275 * sNO -> sIV Response without Request
276 * sRQ -> sRS Response to clients Request
277 * sRS -> sRS Retransmitted Response (8.1.3. SHOULD NOT)
278 * sPO -> sIG Response to an ignored Request or late retransmit
279 * sOP -> sIG Ignore, might be response to ignored Request
280 * sCR -> sIG Ignore, might be response to ignored Request
281 * sCG -> sIG Ignore, might be response to ignored Request
282 * sTW -> sIV Invalid, Request from client in sTW moves to sRQ
283 *
284 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
285 sIV, sRS, sRS, sIG, sIG, sIG, sIG, sIV
286 },
287 [DCCP_PKT_ACK] = {
288 /*
289 * sNO -> sIV No connection
290 * sRQ -> sIV No connection
291 * sRS -> sIV No connection
292 * sPO -> sOP Enter OPEN state (8.1.5.)
293 * sOP -> sOP Regular Ack in OPEN state
294 * sCR -> sIV Waiting for Close from client
295 * sCG -> sCG Ack in CLOSING MAY be processed (8.3.)
296 * sTW -> sIV
297 *
298 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
299 sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
300 },
301 [DCCP_PKT_DATA] = {
302 /*
303 * sNO -> sIV No connection
304 * sRQ -> sIV No connection
305 * sRS -> sIV No connection
306 * sPO -> sOP Enter OPEN state (8.1.5.)
307 * sOP -> sOP Regular Data packet in OPEN state
308 * sCR -> sIV Waiting for Close from client
309 * sCG -> sCG Data in CLOSING MAY be processed (8.3.)
310 * sTW -> sIV
311 *
312 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
313 sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
314 },
315 [DCCP_PKT_DATAACK] = {
316 /*
317 * sNO -> sIV No connection
318 * sRQ -> sIV No connection
319 * sRS -> sIV No connection
320 * sPO -> sOP Enter OPEN state (8.1.5.)
321 * sOP -> sOP Regular DataAck in OPEN state
322 * sCR -> sIV Waiting for Close from client
323 * sCG -> sCG Data in CLOSING MAY be processed (8.3.)
324 * sTW -> sIV
325 *
326 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
327 sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
328 },
329 [DCCP_PKT_CLOSEREQ] = {
330 /*
331 * sNO -> sIV No connection
332 * sRQ -> sIV No connection
333 * sRS -> sIV No connection
334 * sPO -> sOP -> sCR Move directly to CLOSEREQ (8.1.5.)
335 * sOP -> sCR CloseReq in OPEN state
336 * sCR -> sCR Retransmit
337 * sCG -> sCR Simultaneous close, client sends another Close
338 * sTW -> sIV Already closed
339 *
340 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
341 sIV, sIV, sIV, sCR, sCR, sCR, sCR, sIV
342 },
343 [DCCP_PKT_CLOSE] = {
344 /*
345 * sNO -> sIV No connection
346 * sRQ -> sIV No connection
347 * sRS -> sIV No connection
348 * sPO -> sOP -> sCG Move direcly to CLOSING
349 * sOP -> sCG Move to CLOSING
350 * sCR -> sIV Close after CloseReq is invalid
351 * sCG -> sCG Retransmit
352 * sTW -> sIV Already closed
353 *
354 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
355 sIV, sIV, sIV, sCG, sCG, sIV, sCG, sIV
356 },
357 [DCCP_PKT_RESET] = {
358 /*
359 * sNO -> sIV No connection
360 * sRQ -> sTW Reset in response to Request
361 * sRS -> sTW Timeout, SHOULD send Reset (8.1.3.)
362 * sPO -> sTW Timeout, SHOULD send Reset (8.1.3.)
363 * sOP -> sTW
364 * sCR -> sTW
365 * sCG -> sTW
366 * sTW -> sIG Ignore (don't refresh timer)
367 *
368 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW, sTW */
369 sIV, sTW, sTW, sTW, sTW, sTW, sTW, sTW, sIG
370 },
371 [DCCP_PKT_SYNC] = {
372 /*
373 * We currently ignore Sync packets
374 *
375 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
376 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
377 },
378 [DCCP_PKT_SYNCACK] = {
379 /*
380 * We currently ignore SyncAck packets
381 *
382 * sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
383 sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
384 },
385 },
386};
387
1546000f
CG		 388/* this module per-net specifics */
389static int dccp_net_id;
390struct dccp_net {
391 int dccp_loose;
392 unsigned int dccp_timeout[CT_DCCP_MAX + 1];
393#ifdef CONFIG_SYSCTL
394 struct ctl_table_header *sysctl_header;
395 struct ctl_table *sysctl_table;
396#endif
397};
398
399static inline struct dccp_net *dccp_pernet(struct net *net)
400{
401 return net_generic(net, dccp_net_id);
402}
403
09f263cd
JE		 404static bool dccp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
405 struct nf_conntrack_tuple *tuple)
2bc78049
PM		 406{
407 struct dccp_hdr _hdr, *dh;
408
409 dh = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
410 if (dh == NULL)
09f263cd 411 return false;
2bc78049
PM		 412
413 tuple->src.u.dccp.port = dh->dccph_sport;
414 tuple->dst.u.dccp.port = dh->dccph_dport;
09f263cd 415 return true;
2bc78049
PM		 416}
417
09f263cd
JE		 418static bool dccp_invert_tuple(struct nf_conntrack_tuple *inv,
419 const struct nf_conntrack_tuple *tuple)
2bc78049
PM		 420{
421 inv->src.u.dccp.port = tuple->dst.u.dccp.port;
422 inv->dst.u.dccp.port = tuple->src.u.dccp.port;
09f263cd 423 return true;
2bc78049
PM		 424}
425
09f263cd
JE		 426static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb,
427 unsigned int dataoff)
2bc78049 428{
c2a2c7e0 429 struct net *net = nf_ct_net(ct);
1546000f 430 struct dccp_net *dn;
2bc78049
PM		 431 struct dccp_hdr _dh, *dh;
432 const char *msg;
433 u_int8_t state;
434
435 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
436 BUG_ON(dh == NULL);
437
438 state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE];
439 switch (state) {
440 default:
1546000f
CG		 441 dn = dccp_pernet(net);
442 if (dn->dccp_loose == 0) {
2bc78049
PM		 443 msg = "nf_ct_dccp: not picking up existing connection ";
444 goto out_invalid;
445 }
446 case CT_DCCP_REQUEST:
447 break;
448 case CT_DCCP_INVALID:
449 msg = "nf_ct_dccp: invalid state transition ";
450 goto out_invalid;
451 }
452
453 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
454 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
455 ct->proto.dccp.state = CT_DCCP_NONE;
09f263cd 456 return true;
2bc78049
PM		 457
458out_invalid:
c2a2c7e0 459 if (LOG_INVALID(net, IPPROTO_DCCP))
5e8fbe2a 460 nf_log_packet(nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, msg);
09f263cd 461 return false;
2bc78049
PM		 462}
463
464static u64 dccp_ack_seq(const struct dccp_hdr *dh)
465{
466 const struct dccp_hdr_ack_bits *dhack;
467
468 dhack = (void *)dh + __dccp_basic_hdr_len(dh);
469 return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) +
470 ntohl(dhack->dccph_ack_nr_low);
471}
472
473static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb,
474 unsigned int dataoff, enum ip_conntrack_info ctinfo,
76108cea 475 u_int8_t pf, unsigned int hooknum)
2bc78049 476{
c2a2c7e0 477 struct net *net = nf_ct_net(ct);
1546000f 478 struct dccp_net *dn;
2bc78049
PM		 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;
483
484 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
485 BUG_ON(dh == NULL);
486 type = dh->dccph_type;
487
488 if (type == DCCP_PKT_RESET &&
489 !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
490 /* Tear down connection immediately if only reply is a RESET */
718d4ad9 491 nf_ct_kill_acct(ct, ctinfo, skb);
2bc78049
PM		 492 return NF_ACCEPT;
493 }
494
495 write_lock_bh(&dccp_lock);
496
497 role = ct->proto.dccp.role[dir];
498 old_state = ct->proto.dccp.state;
499 new_state = dccp_state_table[role][type][old_state];
500
501 switch (new_state) {
502 case CT_DCCP_REQUEST:
503 if (old_state == CT_DCCP_TIMEWAIT &&
504 role == CT_DCCP_ROLE_SERVER) {
505 /* Reincarnation in the reverse direction: reopen and
506 * reverse client/server roles. */
507 ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT;
508 ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER;
509 }
510 break;
511 case CT_DCCP_RESPOND:
512 if (old_state == CT_DCCP_REQUEST)
513 ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
514 break;
515 case CT_DCCP_PARTOPEN:
516 if (old_state == CT_DCCP_RESPOND &&
517 type == DCCP_PKT_ACK &&
518 dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq)
519 set_bit(IPS_ASSURED_BIT, &ct->status);
520 break;
521 case CT_DCCP_IGNORE:
522 /*
523 * Connection tracking might be out of sync, so we ignore
524 * packets that might establish a new connection and resync
525 * if the server responds with a valid Response.
526 */
527 if (ct->proto.dccp.last_dir == !dir &&
528 ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST &&
529 type == DCCP_PKT_RESPONSE) {
530 ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT;
531 ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER;
532 ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
533 new_state = CT_DCCP_RESPOND;
534 break;
535 }
536 ct->proto.dccp.last_dir = dir;
537 ct->proto.dccp.last_pkt = type;
538
539 write_unlock_bh(&dccp_lock);
c2a2c7e0 540 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 541 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
542 "nf_ct_dccp: invalid packet ignored ");
543 return NF_ACCEPT;
544 case CT_DCCP_INVALID:
545 write_unlock_bh(&dccp_lock);
c2a2c7e0 546 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 547 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
548 "nf_ct_dccp: invalid state transition ");
549 return -NF_ACCEPT;
550 }
551
552 ct->proto.dccp.last_dir = dir;
553 ct->proto.dccp.last_pkt = type;
554 ct->proto.dccp.state = new_state;
555 write_unlock_bh(&dccp_lock);
1546000f 556
b38b1f61
PNA		 557 if (new_state != old_state)
558 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
559
1546000f
CG		 560 dn = dccp_pernet(net);
561 nf_ct_refresh_acct(ct, ctinfo, skb, dn->dccp_timeout[new_state]);
2bc78049
PM		 562
563 return NF_ACCEPT;
564}
565
74c51a14
AD		 566static int dccp_error(struct net *net, struct sk_buff *skb,
567 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
568 u_int8_t pf, unsigned int hooknum)
2bc78049
PM		 569{
570 struct dccp_hdr _dh, *dh;
571 unsigned int dccp_len = skb->len - dataoff;
572 unsigned int cscov;
573 const char *msg;
574
575 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
576 if (dh == NULL) {
577 msg = "nf_ct_dccp: short packet ";
578 goto out_invalid;
579 }
580
581 if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
582 dh->dccph_doff * 4 > dccp_len) {
583 msg = "nf_ct_dccp: truncated/malformed packet ";
584 goto out_invalid;
585 }
586
587 cscov = dccp_len;
588 if (dh->dccph_cscov) {
589 cscov = (dh->dccph_cscov - 1) * 4;
590 if (cscov > dccp_len) {
591 msg = "nf_ct_dccp: bad checksum coverage ";
592 goto out_invalid;
593 }
594 }
595
c04d0552 596 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
2bc78049
PM		 597 nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_DCCP,
598 pf)) {
599 msg = "nf_ct_dccp: bad checksum ";
600 goto out_invalid;
601 }
602
603 if (dh->dccph_type >= DCCP_PKT_INVALID) {
604 msg = "nf_ct_dccp: reserved packet type ";
605 goto out_invalid;
606 }
607
608 return NF_ACCEPT;
609
610out_invalid:
c2a2c7e0 611 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 612 nf_log_packet(pf, 0, skb, NULL, NULL, NULL, msg);
613 return -NF_ACCEPT;
614}
615
616static int dccp_print_tuple(struct seq_file *s,
617 const struct nf_conntrack_tuple *tuple)
618{
619 return seq_printf(s, "sport=%hu dport=%hu ",
620 ntohs(tuple->src.u.dccp.port),
621 ntohs(tuple->dst.u.dccp.port));
622}
623
624static int dccp_print_conntrack(struct seq_file *s, const struct nf_conn *ct)
625{
626 return seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]);
627}
628
629#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
630static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
631 const struct nf_conn *ct)
632{
633 struct nlattr *nest_parms;
634
635 read_lock_bh(&dccp_lock);
636 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP | NLA_F_NESTED);
637 if (!nest_parms)
638 goto nla_put_failure;
639 NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state);
71951b64
PNA		 640 NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_ROLE,
641 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]);
2bc78049
PM		 642 nla_nest_end(skb, nest_parms);
643 read_unlock_bh(&dccp_lock);
644 return 0;
645
646nla_put_failure:
647 read_unlock_bh(&dccp_lock);
648 return -1;
649}
650
651static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
652 [CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 },
71951b64 653 [CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 },
2bc78049
PM		 654};
655
656static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
657{
658 struct nlattr *attr = cda[CTA_PROTOINFO_DCCP];
659 struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1];
660 int err;
661
662 if (!attr)
663 return 0;
664
665 err = nla_parse_nested(tb, CTA_PROTOINFO_DCCP_MAX, attr,
666 dccp_nla_policy);
667 if (err < 0)
668 return err;
669
670 if (!tb[CTA_PROTOINFO_DCCP_STATE] ||
71951b64
PNA		 671 !tb[CTA_PROTOINFO_DCCP_ROLE] ||
672 nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX ||
673 nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) {
2bc78049 674 return -EINVAL;
71951b64 675 }
2bc78049
PM		 676
677 write_lock_bh(&dccp_lock);
678 ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]);
71951b64
PNA		 679 if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) {
680 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
681 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
682 } else {
683 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
684 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
685 }
2bc78049
PM		 686 write_unlock_bh(&dccp_lock);
687 return 0;
688}
a400c30e
HE		 689
690static int dccp_nlattr_size(void)
691{
692 return nla_total_size(0) /* CTA_PROTOINFO_DCCP */
693 + nla_policy_len(dccp_nla_policy, CTA_PROTOINFO_DCCP_MAX + 1);
694}
2bc78049
PM		 695#endif
696
697#ifdef CONFIG_SYSCTL
1546000f
CG		 698/* template, data assigned later */
699static struct ctl_table dccp_sysctl_table[] = {
2bc78049
PM		 700 {
701 .ctl_name = CTL_UNNUMBERED,
702 .procname = "nf_conntrack_dccp_timeout_request",
2bc78049
PM		 703 .maxlen = sizeof(unsigned int),
704 .mode = 0644,
705 .proc_handler = proc_dointvec_jiffies,
706 },
707 {
708 .ctl_name = CTL_UNNUMBERED,
709 .procname = "nf_conntrack_dccp_timeout_respond",
2bc78049
PM		 710 .maxlen = sizeof(unsigned int),
711 .mode = 0644,
712 .proc_handler = proc_dointvec_jiffies,
713 },
714 {
715 .ctl_name = CTL_UNNUMBERED,
716 .procname = "nf_conntrack_dccp_timeout_partopen",
2bc78049
PM		 717 .maxlen = sizeof(unsigned int),
718 .mode = 0644,
719 .proc_handler = proc_dointvec_jiffies,
720 },
721 {
722 .ctl_name = CTL_UNNUMBERED,
723 .procname = "nf_conntrack_dccp_timeout_open",
2bc78049
PM		 724 .maxlen = sizeof(unsigned int),
725 .mode = 0644,
726 .proc_handler = proc_dointvec_jiffies,
727 },
728 {
729 .ctl_name = CTL_UNNUMBERED,
730 .procname = "nf_conntrack_dccp_timeout_closereq",
2bc78049
PM		 731 .maxlen = sizeof(unsigned int),
732 .mode = 0644,
733 .proc_handler = proc_dointvec_jiffies,
734 },
735 {
736 .ctl_name = CTL_UNNUMBERED,
737 .procname = "nf_conntrack_dccp_timeout_closing",
2bc78049
PM		 738 .maxlen = sizeof(unsigned int),
739 .mode = 0644,
740 .proc_handler = proc_dointvec_jiffies,
741 },
742 {
743 .ctl_name = CTL_UNNUMBERED,
744 .procname = "nf_conntrack_dccp_timeout_timewait",
2bc78049
PM		 745 .maxlen = sizeof(unsigned int),
746 .mode = 0644,
747 .proc_handler = proc_dointvec_jiffies,
748 },
749 {
750 .ctl_name = CTL_UNNUMBERED,
751 .procname = "nf_conntrack_dccp_loose",
1546000f 752 .maxlen = sizeof(int),
2bc78049
PM		 753 .mode = 0644,
754 .proc_handler = proc_dointvec,
755 },
756 {
757 .ctl_name = 0,
758 }
759};
760#endif /* CONFIG_SYSCTL */
761
762static struct nf_conntrack_l4proto dccp_proto4 __read_mostly = {
763 .l3proto = AF_INET,
764 .l4proto = IPPROTO_DCCP,
765 .name = "dccp",
766 .pkt_to_tuple = dccp_pkt_to_tuple,
767 .invert_tuple = dccp_invert_tuple,
768 .new = dccp_new,
769 .packet = dccp_packet,
770 .error = dccp_error,
771 .print_tuple = dccp_print_tuple,
772 .print_conntrack = dccp_print_conntrack,
773#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
774 .to_nlattr = dccp_to_nlattr,
a400c30e 775 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 776 .from_nlattr = nlattr_to_dccp,
777 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 778 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 779 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
780 .nla_policy = nf_ct_port_nla_policy,
781#endif
2bc78049
PM		 782};
783
784static struct nf_conntrack_l4proto dccp_proto6 __read_mostly = {
785 .l3proto = AF_INET6,
786 .l4proto = IPPROTO_DCCP,
787 .name = "dccp",
788 .pkt_to_tuple = dccp_pkt_to_tuple,
789 .invert_tuple = dccp_invert_tuple,
790 .new = dccp_new,
791 .packet = dccp_packet,
792 .error = dccp_error,
793 .print_tuple = dccp_print_tuple,
794 .print_conntrack = dccp_print_conntrack,
795#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
796 .to_nlattr = dccp_to_nlattr,
5ff48294 797 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 798 .from_nlattr = nlattr_to_dccp,
799 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 800 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 801 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
802 .nla_policy = nf_ct_port_nla_policy,
803#endif
1546000f
CG		 804};
805
806static __net_init int dccp_net_init(struct net *net)
807{
808 struct dccp_net *dn;
809 int err;
810
811 dn = kmalloc(sizeof(*dn), GFP_KERNEL);
812 if (!dn)
813 return -ENOMEM;
814
815 /* default values */
816 dn->dccp_loose = 1;
817 dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL;
818 dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL;
819 dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL;
820 dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ;
821 dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ;
822 dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ;
823 dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL;
824
825 err = net_assign_generic(net, dccp_net_id, dn);
826 if (err)
827 goto out;
828
2bc78049 829#ifdef CONFIG_SYSCTL
1546000f
CG		 830 err = -ENOMEM;
831 dn->sysctl_table = kmemdup(dccp_sysctl_table,
832 sizeof(dccp_sysctl_table), GFP_KERNEL);
833 if (!dn->sysctl_table)
834 goto out;
835
836 dn->sysctl_table[0].data = &dn->dccp_timeout[CT_DCCP_REQUEST];
837 dn->sysctl_table[1].data = &dn->dccp_timeout[CT_DCCP_RESPOND];
838 dn->sysctl_table[2].data = &dn->dccp_timeout[CT_DCCP_PARTOPEN];
839 dn->sysctl_table[3].data = &dn->dccp_timeout[CT_DCCP_OPEN];
840 dn->sysctl_table[4].data = &dn->dccp_timeout[CT_DCCP_CLOSEREQ];
841 dn->sysctl_table[5].data = &dn->dccp_timeout[CT_DCCP_CLOSING];
842 dn->sysctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT];
843 dn->sysctl_table[7].data = &dn->dccp_loose;
844
845 dn->sysctl_header = register_net_sysctl_table(net,
846 nf_net_netfilter_sysctl_path, dn->sysctl_table);
847 if (!dn->sysctl_header) {
848 kfree(dn->sysctl_table);
849 goto out;
850 }
2bc78049 851#endif
1546000f
CG		 852
853 return 0;
854
855out:
856 kfree(dn);
857 return err;
858}
859
860static __net_exit void dccp_net_exit(struct net *net)
861{
862 struct dccp_net *dn = dccp_pernet(net);
863#ifdef CONFIG_SYSCTL
864 unregister_net_sysctl_table(dn->sysctl_header);
865 kfree(dn->sysctl_table);
866#endif
867 kfree(dn);
868
869 net_assign_generic(net, dccp_net_id, NULL);
870}
871
872static struct pernet_operations dccp_net_ops = {
873 .init = dccp_net_init,
874 .exit = dccp_net_exit,
2bc78049
PM		 875};
876
877static int __init nf_conntrack_proto_dccp_init(void)
878{
879 int err;
880
1546000f 881 err = register_pernet_gen_subsys(&dccp_net_id, &dccp_net_ops);
2bc78049
PM		 882 if (err < 0)
883 goto err1;
884
1546000f 885 err = nf_conntrack_l4proto_register(&dccp_proto4);
2bc78049
PM		 886 if (err < 0)
887 goto err2;
1546000f
CG		 888
889 err = nf_conntrack_l4proto_register(&dccp_proto6);
890 if (err < 0)
891 goto err3;
2bc78049
PM		 892 return 0;
893
1546000f 894err3:
2bc78049 895 nf_conntrack_l4proto_unregister(&dccp_proto4);
1546000f
CG		 896err2:
897 unregister_pernet_gen_subsys(dccp_net_id, &dccp_net_ops);
2bc78049
PM		 898err1:
899 return err;
900}
901
902static void __exit nf_conntrack_proto_dccp_fini(void)
903{
1546000f 904 unregister_pernet_gen_subsys(dccp_net_id, &dccp_net_ops);
2bc78049
PM		 905 nf_conntrack_l4proto_unregister(&dccp_proto6);
906 nf_conntrack_l4proto_unregister(&dccp_proto4);
907}
908
909module_init(nf_conntrack_proto_dccp_init);
910module_exit(nf_conntrack_proto_dccp_fini);
911
912MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
913MODULE_DESCRIPTION("DCCP connection tracking protocol helper");
914MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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