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netfilter: nf_ct_tcp: fix accepting invalid RST segments
[GitHub/mt8127/android_kernel_alcatel_ttab.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>
25#include <net/netfilter/nf_log.h>
26
27static DEFINE_RWLOCK(dccp_lock);
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/*
101 * DCCP state transistion table
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
CG		 387/* this module per-net specifics */
388static int dccp_net_id;
389struct dccp_net {
390 int dccp_loose;
391 unsigned int dccp_timeout[CT_DCCP_MAX + 1];
392#ifdef CONFIG_SYSCTL
393 struct ctl_table_header *sysctl_header;
394 struct ctl_table *sysctl_table;
395#endif
396};
397
398static inline struct dccp_net *dccp_pernet(struct net *net)
399{
400 return net_generic(net, dccp_net_id);
401}
402
09f263cd
JE		 403static bool dccp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
404 struct nf_conntrack_tuple *tuple)
2bc78049
PM		 405{
406 struct dccp_hdr _hdr, *dh;
407
408 dh = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
409 if (dh == NULL)
09f263cd 410 return false;
2bc78049
PM		 411
412 tuple->src.u.dccp.port = dh->dccph_sport;
413 tuple->dst.u.dccp.port = dh->dccph_dport;
09f263cd 414 return true;
2bc78049
PM		 415}
416
09f263cd
JE		 417static bool dccp_invert_tuple(struct nf_conntrack_tuple *inv,
418 const struct nf_conntrack_tuple *tuple)
2bc78049
PM		 419{
420 inv->src.u.dccp.port = tuple->dst.u.dccp.port;
421 inv->dst.u.dccp.port = tuple->src.u.dccp.port;
09f263cd 422 return true;
2bc78049
PM		 423}
424
09f263cd
JE		 425static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb,
426 unsigned int dataoff)
2bc78049 427{
c2a2c7e0 428 struct net *net = nf_ct_net(ct);
1546000f 429 struct dccp_net *dn;
2bc78049
PM		 430 struct dccp_hdr _dh, *dh;
431 const char *msg;
432 u_int8_t state;
433
434 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
435 BUG_ON(dh == NULL);
436
437 state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE];
438 switch (state) {
439 default:
1546000f
CG		 440 dn = dccp_pernet(net);
441 if (dn->dccp_loose == 0) {
2bc78049
PM		 442 msg = "nf_ct_dccp: not picking up existing connection ";
443 goto out_invalid;
444 }
445 case CT_DCCP_REQUEST:
446 break;
447 case CT_DCCP_INVALID:
448 msg = "nf_ct_dccp: invalid state transition ";
449 goto out_invalid;
450 }
451
452 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
453 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
454 ct->proto.dccp.state = CT_DCCP_NONE;
09f263cd 455 return true;
2bc78049
PM		 456
457out_invalid:
c2a2c7e0 458 if (LOG_INVALID(net, IPPROTO_DCCP))
5e8fbe2a 459 nf_log_packet(nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, msg);
09f263cd 460 return false;
2bc78049
PM		 461}
462
463static u64 dccp_ack_seq(const struct dccp_hdr *dh)
464{
465 const struct dccp_hdr_ack_bits *dhack;
466
467 dhack = (void *)dh + __dccp_basic_hdr_len(dh);
468 return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) +
469 ntohl(dhack->dccph_ack_nr_low);
470}
471
472static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb,
473 unsigned int dataoff, enum ip_conntrack_info ctinfo,
76108cea 474 u_int8_t pf, unsigned int hooknum)
2bc78049 475{
c2a2c7e0 476 struct net *net = nf_ct_net(ct);
1546000f 477 struct dccp_net *dn;
2bc78049
PM		 478 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
479 struct dccp_hdr _dh, *dh;
480 u_int8_t type, old_state, new_state;
481 enum ct_dccp_roles role;
482
483 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
484 BUG_ON(dh == NULL);
485 type = dh->dccph_type;
486
487 if (type == DCCP_PKT_RESET &&
488 !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
489 /* Tear down connection immediately if only reply is a RESET */
718d4ad9 490 nf_ct_kill_acct(ct, ctinfo, skb);
2bc78049
PM		 491 return NF_ACCEPT;
492 }
493
494 write_lock_bh(&dccp_lock);
495
496 role = ct->proto.dccp.role[dir];
497 old_state = ct->proto.dccp.state;
498 new_state = dccp_state_table[role][type][old_state];
499
500 switch (new_state) {
501 case CT_DCCP_REQUEST:
502 if (old_state == CT_DCCP_TIMEWAIT &&
503 role == CT_DCCP_ROLE_SERVER) {
504 /* Reincarnation in the reverse direction: reopen and
505 * reverse client/server roles. */
506 ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT;
507 ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER;
508 }
509 break;
510 case CT_DCCP_RESPOND:
511 if (old_state == CT_DCCP_REQUEST)
512 ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
513 break;
514 case CT_DCCP_PARTOPEN:
515 if (old_state == CT_DCCP_RESPOND &&
516 type == DCCP_PKT_ACK &&
517 dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq)
518 set_bit(IPS_ASSURED_BIT, &ct->status);
519 break;
520 case CT_DCCP_IGNORE:
521 /*
522 * Connection tracking might be out of sync, so we ignore
523 * packets that might establish a new connection and resync
524 * if the server responds with a valid Response.
525 */
526 if (ct->proto.dccp.last_dir == !dir &&
527 ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST &&
528 type == DCCP_PKT_RESPONSE) {
529 ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT;
530 ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER;
531 ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
532 new_state = CT_DCCP_RESPOND;
533 break;
534 }
535 ct->proto.dccp.last_dir = dir;
536 ct->proto.dccp.last_pkt = type;
537
538 write_unlock_bh(&dccp_lock);
c2a2c7e0 539 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 540 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
541 "nf_ct_dccp: invalid packet ignored ");
542 return NF_ACCEPT;
543 case CT_DCCP_INVALID:
544 write_unlock_bh(&dccp_lock);
c2a2c7e0 545 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 546 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
547 "nf_ct_dccp: invalid state transition ");
548 return -NF_ACCEPT;
549 }
550
551 ct->proto.dccp.last_dir = dir;
552 ct->proto.dccp.last_pkt = type;
553 ct->proto.dccp.state = new_state;
554 write_unlock_bh(&dccp_lock);
1546000f
CG		 555
556 dn = dccp_pernet(net);
557 nf_ct_refresh_acct(ct, ctinfo, skb, dn->dccp_timeout[new_state]);
2bc78049
PM		 558
559 return NF_ACCEPT;
560}
561
74c51a14
AD		 562static int dccp_error(struct net *net, struct sk_buff *skb,
563 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
564 u_int8_t pf, unsigned int hooknum)
2bc78049
PM		 565{
566 struct dccp_hdr _dh, *dh;
567 unsigned int dccp_len = skb->len - dataoff;
568 unsigned int cscov;
569 const char *msg;
570
571 dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);
572 if (dh == NULL) {
573 msg = "nf_ct_dccp: short packet ";
574 goto out_invalid;
575 }
576
577 if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
578 dh->dccph_doff * 4 > dccp_len) {
579 msg = "nf_ct_dccp: truncated/malformed packet ";
580 goto out_invalid;
581 }
582
583 cscov = dccp_len;
584 if (dh->dccph_cscov) {
585 cscov = (dh->dccph_cscov - 1) * 4;
586 if (cscov > dccp_len) {
587 msg = "nf_ct_dccp: bad checksum coverage ";
588 goto out_invalid;
589 }
590 }
591
c04d0552 592 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
2bc78049
PM		 593 nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_DCCP,
594 pf)) {
595 msg = "nf_ct_dccp: bad checksum ";
596 goto out_invalid;
597 }
598
599 if (dh->dccph_type >= DCCP_PKT_INVALID) {
600 msg = "nf_ct_dccp: reserved packet type ";
601 goto out_invalid;
602 }
603
604 return NF_ACCEPT;
605
606out_invalid:
c2a2c7e0 607 if (LOG_INVALID(net, IPPROTO_DCCP))
2bc78049
PM		 608 nf_log_packet(pf, 0, skb, NULL, NULL, NULL, msg);
609 return -NF_ACCEPT;
610}
611
612static int dccp_print_tuple(struct seq_file *s,
613 const struct nf_conntrack_tuple *tuple)
614{
615 return seq_printf(s, "sport=%hu dport=%hu ",
616 ntohs(tuple->src.u.dccp.port),
617 ntohs(tuple->dst.u.dccp.port));
618}
619
620static int dccp_print_conntrack(struct seq_file *s, const struct nf_conn *ct)
621{
622 return seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]);
623}
624
625#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
626static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
627 const struct nf_conn *ct)
628{
629 struct nlattr *nest_parms;
630
631 read_lock_bh(&dccp_lock);
632 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP | NLA_F_NESTED);
633 if (!nest_parms)
634 goto nla_put_failure;
635 NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state);
71951b64
PNA		 636 NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_ROLE,
637 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]);
2bc78049
PM		 638 nla_nest_end(skb, nest_parms);
639 read_unlock_bh(&dccp_lock);
640 return 0;
641
642nla_put_failure:
643 read_unlock_bh(&dccp_lock);
644 return -1;
645}
646
647static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
648 [CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 },
71951b64 649 [CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 },
2bc78049
PM		 650};
651
652static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
653{
654 struct nlattr *attr = cda[CTA_PROTOINFO_DCCP];
655 struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1];
656 int err;
657
658 if (!attr)
659 return 0;
660
661 err = nla_parse_nested(tb, CTA_PROTOINFO_DCCP_MAX, attr,
662 dccp_nla_policy);
663 if (err < 0)
664 return err;
665
666 if (!tb[CTA_PROTOINFO_DCCP_STATE] ||
71951b64
PNA		 667 !tb[CTA_PROTOINFO_DCCP_ROLE] ||
668 nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX ||
669 nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) {
2bc78049 670 return -EINVAL;
71951b64 671 }
2bc78049
PM		 672
673 write_lock_bh(&dccp_lock);
674 ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]);
71951b64
PNA		 675 if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) {
676 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
677 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
678 } else {
679 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
680 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
681 }
2bc78049
PM		 682 write_unlock_bh(&dccp_lock);
683 return 0;
684}
a400c30e
HE		 685
686static int dccp_nlattr_size(void)
687{
688 return nla_total_size(0) /* CTA_PROTOINFO_DCCP */
689 + nla_policy_len(dccp_nla_policy, CTA_PROTOINFO_DCCP_MAX + 1);
690}
2bc78049
PM		 691#endif
692
693#ifdef CONFIG_SYSCTL
1546000f
CG		 694/* template, data assigned later */
695static struct ctl_table dccp_sysctl_table[] = {
2bc78049
PM		 696 {
697 .ctl_name = CTL_UNNUMBERED,
698 .procname = "nf_conntrack_dccp_timeout_request",
2bc78049
PM		 699 .maxlen = sizeof(unsigned int),
700 .mode = 0644,
701 .proc_handler = proc_dointvec_jiffies,
702 },
703 {
704 .ctl_name = CTL_UNNUMBERED,
705 .procname = "nf_conntrack_dccp_timeout_respond",
2bc78049
PM		 706 .maxlen = sizeof(unsigned int),
707 .mode = 0644,
708 .proc_handler = proc_dointvec_jiffies,
709 },
710 {
711 .ctl_name = CTL_UNNUMBERED,
712 .procname = "nf_conntrack_dccp_timeout_partopen",
2bc78049
PM		 713 .maxlen = sizeof(unsigned int),
714 .mode = 0644,
715 .proc_handler = proc_dointvec_jiffies,
716 },
717 {
718 .ctl_name = CTL_UNNUMBERED,
719 .procname = "nf_conntrack_dccp_timeout_open",
2bc78049
PM		 720 .maxlen = sizeof(unsigned int),
721 .mode = 0644,
722 .proc_handler = proc_dointvec_jiffies,
723 },
724 {
725 .ctl_name = CTL_UNNUMBERED,
726 .procname = "nf_conntrack_dccp_timeout_closereq",
2bc78049
PM		 727 .maxlen = sizeof(unsigned int),
728 .mode = 0644,
729 .proc_handler = proc_dointvec_jiffies,
730 },
731 {
732 .ctl_name = CTL_UNNUMBERED,
733 .procname = "nf_conntrack_dccp_timeout_closing",
2bc78049
PM		 734 .maxlen = sizeof(unsigned int),
735 .mode = 0644,
736 .proc_handler = proc_dointvec_jiffies,
737 },
738 {
739 .ctl_name = CTL_UNNUMBERED,
740 .procname = "nf_conntrack_dccp_timeout_timewait",
2bc78049
PM		 741 .maxlen = sizeof(unsigned int),
742 .mode = 0644,
743 .proc_handler = proc_dointvec_jiffies,
744 },
745 {
746 .ctl_name = CTL_UNNUMBERED,
747 .procname = "nf_conntrack_dccp_loose",
1546000f 748 .maxlen = sizeof(int),
2bc78049
PM		 749 .mode = 0644,
750 .proc_handler = proc_dointvec,
751 },
752 {
753 .ctl_name = 0,
754 }
755};
756#endif /* CONFIG_SYSCTL */
757
758static struct nf_conntrack_l4proto dccp_proto4 __read_mostly = {
759 .l3proto = AF_INET,
760 .l4proto = IPPROTO_DCCP,
761 .name = "dccp",
762 .pkt_to_tuple = dccp_pkt_to_tuple,
763 .invert_tuple = dccp_invert_tuple,
764 .new = dccp_new,
765 .packet = dccp_packet,
766 .error = dccp_error,
767 .print_tuple = dccp_print_tuple,
768 .print_conntrack = dccp_print_conntrack,
769#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
770 .to_nlattr = dccp_to_nlattr,
a400c30e 771 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 772 .from_nlattr = nlattr_to_dccp,
773 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 774 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 775 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
776 .nla_policy = nf_ct_port_nla_policy,
777#endif
2bc78049
PM		 778};
779
780static struct nf_conntrack_l4proto dccp_proto6 __read_mostly = {
781 .l3proto = AF_INET6,
782 .l4proto = IPPROTO_DCCP,
783 .name = "dccp",
784 .pkt_to_tuple = dccp_pkt_to_tuple,
785 .invert_tuple = dccp_invert_tuple,
786 .new = dccp_new,
787 .packet = dccp_packet,
788 .error = dccp_error,
789 .print_tuple = dccp_print_tuple,
790 .print_conntrack = dccp_print_conntrack,
791#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
792 .to_nlattr = dccp_to_nlattr,
5ff48294 793 .nlattr_size = dccp_nlattr_size,
2bc78049
PM		 794 .from_nlattr = nlattr_to_dccp,
795 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e 796 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
2bc78049
PM		 797 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
798 .nla_policy = nf_ct_port_nla_policy,
799#endif
1546000f
CG		 800};
801
802static __net_init int dccp_net_init(struct net *net)
803{
804 struct dccp_net *dn;
805 int err;
806
807 dn = kmalloc(sizeof(*dn), GFP_KERNEL);
808 if (!dn)
809 return -ENOMEM;
810
811 /* default values */
812 dn->dccp_loose = 1;
813 dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL;
814 dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL;
815 dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL;
816 dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ;
817 dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ;
818 dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ;
819 dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL;
820
821 err = net_assign_generic(net, dccp_net_id, dn);
822 if (err)
823 goto out;
824
2bc78049 825#ifdef CONFIG_SYSCTL
1546000f
CG		 826 err = -ENOMEM;
827 dn->sysctl_table = kmemdup(dccp_sysctl_table,
828 sizeof(dccp_sysctl_table), GFP_KERNEL);
829 if (!dn->sysctl_table)
830 goto out;
831
832 dn->sysctl_table[0].data = &dn->dccp_timeout[CT_DCCP_REQUEST];
833 dn->sysctl_table[1].data = &dn->dccp_timeout[CT_DCCP_RESPOND];
834 dn->sysctl_table[2].data = &dn->dccp_timeout[CT_DCCP_PARTOPEN];
835 dn->sysctl_table[3].data = &dn->dccp_timeout[CT_DCCP_OPEN];
836 dn->sysctl_table[4].data = &dn->dccp_timeout[CT_DCCP_CLOSEREQ];
837 dn->sysctl_table[5].data = &dn->dccp_timeout[CT_DCCP_CLOSING];
838 dn->sysctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT];
839 dn->sysctl_table[7].data = &dn->dccp_loose;
840
841 dn->sysctl_header = register_net_sysctl_table(net,
842 nf_net_netfilter_sysctl_path, dn->sysctl_table);
843 if (!dn->sysctl_header) {
844 kfree(dn->sysctl_table);
845 goto out;
846 }
2bc78049 847#endif
1546000f
CG		 848
849 return 0;
850
851out:
852 kfree(dn);
853 return err;
854}
855
856static __net_exit void dccp_net_exit(struct net *net)
857{
858 struct dccp_net *dn = dccp_pernet(net);
859#ifdef CONFIG_SYSCTL
860 unregister_net_sysctl_table(dn->sysctl_header);
861 kfree(dn->sysctl_table);
862#endif
863 kfree(dn);
864
865 net_assign_generic(net, dccp_net_id, NULL);
866}
867
868static struct pernet_operations dccp_net_ops = {
869 .init = dccp_net_init,
870 .exit = dccp_net_exit,
2bc78049
PM		 871};
872
873static int __init nf_conntrack_proto_dccp_init(void)
874{
875 int err;
876
1546000f 877 err = register_pernet_gen_subsys(&dccp_net_id, &dccp_net_ops);
2bc78049
PM		 878 if (err < 0)
879 goto err1;
880
1546000f 881 err = nf_conntrack_l4proto_register(&dccp_proto4);
2bc78049
PM		 882 if (err < 0)
883 goto err2;
1546000f
CG		 884
885 err = nf_conntrack_l4proto_register(&dccp_proto6);
886 if (err < 0)
887 goto err3;
2bc78049
PM		 888 return 0;
889
1546000f 890err3:
2bc78049 891 nf_conntrack_l4proto_unregister(&dccp_proto4);
1546000f
CG		 892err2:
893 unregister_pernet_gen_subsys(dccp_net_id, &dccp_net_ops);
2bc78049
PM		 894err1:
895 return err;
896}
897
898static void __exit nf_conntrack_proto_dccp_fini(void)
899{
1546000f 900 unregister_pernet_gen_subsys(dccp_net_id, &dccp_net_ops);
2bc78049
PM		 901 nf_conntrack_l4proto_unregister(&dccp_proto6);
902 nf_conntrack_l4proto_unregister(&dccp_proto4);
903}
904
905module_init(nf_conntrack_proto_dccp_init);
906module_exit(nf_conntrack_proto_dccp_fini);
907
908MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
909MODULE_DESCRIPTION("DCCP connection tracking protocol helper");
910MODULE_LICENSE("GPL");
kernel source for telekom puls (alcatel/mediatek)