1 /*
2 * Connection tracking protocol helper module for SCTP.
3 *
4 * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
5 * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
6 *
7 * SCTP is defined in RFC 2960. References to various sections in this code
8 * are to this RFC.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/types.h>
16 #include <linux/timer.h>
17 #include <linux/netfilter.h>
18 #include <linux/in.h>
19 #include <linux/ip.h>
20 #include <linux/sctp.h>
21 #include <linux/string.h>
22 #include <linux/seq_file.h>
23 #include <linux/spinlock.h>
24 #include <linux/interrupt.h>
25 #include <net/sctp/checksum.h>
26
27 #include <net/netfilter/nf_log.h>
28 #include <net/netfilter/nf_conntrack.h>
29 #include <net/netfilter/nf_conntrack_l4proto.h>
30 #include <net/netfilter/nf_conntrack_ecache.h>
31 #include <net/netfilter/nf_conntrack_timeout.h>
32
33 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
34 closely. They're more complex. --RR
35
36 And so for me for SCTP :D -Kiran */
37
38 static const char *const sctp_conntrack_names[] = {
39 "NONE",
40 "CLOSED",
41 "COOKIE_WAIT",
42 "COOKIE_ECHOED",
43 "ESTABLISHED",
44 "SHUTDOWN_SENT",
45 "SHUTDOWN_RECD",
46 "SHUTDOWN_ACK_SENT",
47 "HEARTBEAT_SENT",
48 "HEARTBEAT_ACKED",
49 };
50
51 #define SECS * HZ
52 #define MINS * 60 SECS
53 #define HOURS * 60 MINS
54 #define DAYS * 24 HOURS
55
56 static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
57 [SCTP_CONNTRACK_CLOSED] = 10 SECS,
58 [SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS,
59 [SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS,
60 [SCTP_CONNTRACK_ESTABLISHED] = 5 DAYS,
61 [SCTP_CONNTRACK_SHUTDOWN_SENT] = 300 SECS / 1000,
62 [SCTP_CONNTRACK_SHUTDOWN_RECD] = 300 SECS / 1000,
63 [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS,
64 [SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS,
65 [SCTP_CONNTRACK_HEARTBEAT_ACKED] = 210 SECS,
66 };
67
68 #define sNO SCTP_CONNTRACK_NONE
69 #define sCL SCTP_CONNTRACK_CLOSED
70 #define sCW SCTP_CONNTRACK_COOKIE_WAIT
71 #define sCE SCTP_CONNTRACK_COOKIE_ECHOED
72 #define sES SCTP_CONNTRACK_ESTABLISHED
73 #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
74 #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
75 #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
76 #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
77 #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
78 #define sIV SCTP_CONNTRACK_MAX
79
80 /*
81 These are the descriptions of the states:
82
83 NOTE: These state names are tantalizingly similar to the states of an
84 SCTP endpoint. But the interpretation of the states is a little different,
85 considering that these are the states of the connection and not of an end
86 point. Please note the subtleties. -Kiran
87
88 NONE - Nothing so far.
89 COOKIE WAIT - We have seen an INIT chunk in the original direction, or also
90 an INIT_ACK chunk in the reply direction.
91 COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction.
92 ESTABLISHED - We have seen a COOKIE_ACK in the reply direction.
93 SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction.
94 SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply directoin.
95 SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
96 to that of the SHUTDOWN chunk.
97 CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
98 the SHUTDOWN chunk. Connection is closed.
99 HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow.
100 HEARTBEAT_ACKED - We have seen a HEARTBEAT-ACK in the direction opposite to
101 that of the HEARTBEAT chunk. Secondary connection is
102 established.
103 */
104
105 /* TODO
106 - I have assumed that the first INIT is in the original direction.
107 This messes things when an INIT comes in the reply direction in CLOSED
108 state.
109 - Check the error type in the reply dir before transitioning from
110 cookie echoed to closed.
111 - Sec 5.2.4 of RFC 2960
112 - Full Multi Homing support.
113 */
114
115 /* SCTP conntrack state transitions */
116 static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
117 {
118 /* ORIGINAL */
119 /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
120 /* init */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
121 /* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
122 /* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
123 /* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
124 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
125 /* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
126 /* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
127 /* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
128 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
129 /* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
130 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
131 },
132 {
133 /* REPLY */
134 /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
135 /* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
136 /* init_ack */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
137 /* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
138 /* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
139 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
140 /* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
141 /* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
142 /* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
143 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
144 /* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
145 /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
146 }
147 };
148
sctp_pernet(struct net * net)149 static inline struct nf_sctp_net *sctp_pernet(struct net *net)
150 {
151 return &net->ct.nf_ct_proto.sctp;
152 }
153
154 #ifdef CONFIG_NF_CONNTRACK_PROCFS
155 /* Print out the private part of the conntrack. */
sctp_print_conntrack(struct seq_file * s,struct nf_conn * ct)156 static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
157 {
158 seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
159 }
160 #endif
161
162 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \
163 for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \
164 (offset) < (skb)->len && \
165 ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \
166 (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
167
168 /* Some validity checks to make sure the chunks are fine */
do_basic_checks(struct nf_conn * ct,const struct sk_buff * skb,unsigned int dataoff,unsigned long * map)169 static int do_basic_checks(struct nf_conn *ct,
170 const struct sk_buff *skb,
171 unsigned int dataoff,
172 unsigned long *map)
173 {
174 u_int32_t offset, count;
175 struct sctp_chunkhdr _sch, *sch;
176 int flag;
177
178 flag = 0;
179
180 for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
181 pr_debug("Chunk Num: %d Type: %d\n", count, sch->type);
182
183 if (sch->type == SCTP_CID_INIT ||
184 sch->type == SCTP_CID_INIT_ACK ||
185 sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
186 flag = 1;
187
188 /*
189 * Cookie Ack/Echo chunks not the first OR
190 * Init / Init Ack / Shutdown compl chunks not the only chunks
191 * OR zero-length.
192 */
193 if (((sch->type == SCTP_CID_COOKIE_ACK ||
194 sch->type == SCTP_CID_COOKIE_ECHO ||
195 flag) &&
196 count != 0) || !sch->length) {
197 pr_debug("Basic checks failed\n");
198 return 1;
199 }
200
201 if (map)
202 set_bit(sch->type, map);
203 }
204
205 pr_debug("Basic checks passed\n");
206 return count == 0;
207 }
208
sctp_new_state(enum ip_conntrack_dir dir,enum sctp_conntrack cur_state,int chunk_type)209 static int sctp_new_state(enum ip_conntrack_dir dir,
210 enum sctp_conntrack cur_state,
211 int chunk_type)
212 {
213 int i;
214
215 pr_debug("Chunk type: %d\n", chunk_type);
216
217 switch (chunk_type) {
218 case SCTP_CID_INIT:
219 pr_debug("SCTP_CID_INIT\n");
220 i = 0;
221 break;
222 case SCTP_CID_INIT_ACK:
223 pr_debug("SCTP_CID_INIT_ACK\n");
224 i = 1;
225 break;
226 case SCTP_CID_ABORT:
227 pr_debug("SCTP_CID_ABORT\n");
228 i = 2;
229 break;
230 case SCTP_CID_SHUTDOWN:
231 pr_debug("SCTP_CID_SHUTDOWN\n");
232 i = 3;
233 break;
234 case SCTP_CID_SHUTDOWN_ACK:
235 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
236 i = 4;
237 break;
238 case SCTP_CID_ERROR:
239 pr_debug("SCTP_CID_ERROR\n");
240 i = 5;
241 break;
242 case SCTP_CID_COOKIE_ECHO:
243 pr_debug("SCTP_CID_COOKIE_ECHO\n");
244 i = 6;
245 break;
246 case SCTP_CID_COOKIE_ACK:
247 pr_debug("SCTP_CID_COOKIE_ACK\n");
248 i = 7;
249 break;
250 case SCTP_CID_SHUTDOWN_COMPLETE:
251 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
252 i = 8;
253 break;
254 case SCTP_CID_HEARTBEAT:
255 pr_debug("SCTP_CID_HEARTBEAT");
256 i = 9;
257 break;
258 case SCTP_CID_HEARTBEAT_ACK:
259 pr_debug("SCTP_CID_HEARTBEAT_ACK");
260 i = 10;
261 break;
262 default:
263 /* Other chunks like DATA or SACK do not change the state */
264 pr_debug("Unknown chunk type, Will stay in %s\n",
265 sctp_conntrack_names[cur_state]);
266 return cur_state;
267 }
268
269 pr_debug("dir: %d cur_state: %s chunk_type: %d new_state: %s\n",
270 dir, sctp_conntrack_names[cur_state], chunk_type,
271 sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
272
273 return sctp_conntracks[dir][i][cur_state];
274 }
275
276 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
sctp_packet(struct nf_conn * ct,const struct sk_buff * skb,unsigned int dataoff,enum ip_conntrack_info ctinfo)277 static int sctp_packet(struct nf_conn *ct,
278 const struct sk_buff *skb,
279 unsigned int dataoff,
280 enum ip_conntrack_info ctinfo)
281 {
282 enum sctp_conntrack new_state, old_state;
283 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
284 const struct sctphdr *sh;
285 struct sctphdr _sctph;
286 const struct sctp_chunkhdr *sch;
287 struct sctp_chunkhdr _sch;
288 u_int32_t offset, count;
289 unsigned int *timeouts;
290 unsigned long map[256 / sizeof(unsigned long)] = { 0 };
291
292 sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
293 if (sh == NULL)
294 goto out;
295
296 if (do_basic_checks(ct, skb, dataoff, map) != 0)
297 goto out;
298
299 /* Check the verification tag (Sec 8.5) */
300 if (!test_bit(SCTP_CID_INIT, map) &&
301 !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
302 !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
303 !test_bit(SCTP_CID_ABORT, map) &&
304 !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
305 !test_bit(SCTP_CID_HEARTBEAT, map) &&
306 !test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
307 sh->vtag != ct->proto.sctp.vtag[dir]) {
308 pr_debug("Verification tag check failed\n");
309 goto out;
310 }
311
312 old_state = new_state = SCTP_CONNTRACK_NONE;
313 spin_lock_bh(&ct->lock);
314 for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
315 /* Special cases of Verification tag check (Sec 8.5.1) */
316 if (sch->type == SCTP_CID_INIT) {
317 /* Sec 8.5.1 (A) */
318 if (sh->vtag != 0)
319 goto out_unlock;
320 } else if (sch->type == SCTP_CID_ABORT) {
321 /* Sec 8.5.1 (B) */
322 if (sh->vtag != ct->proto.sctp.vtag[dir] &&
323 sh->vtag != ct->proto.sctp.vtag[!dir])
324 goto out_unlock;
325 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
326 /* Sec 8.5.1 (C) */
327 if (sh->vtag != ct->proto.sctp.vtag[dir] &&
328 sh->vtag != ct->proto.sctp.vtag[!dir] &&
329 sch->flags & SCTP_CHUNK_FLAG_T)
330 goto out_unlock;
331 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
332 /* Sec 8.5.1 (D) */
333 if (sh->vtag != ct->proto.sctp.vtag[dir])
334 goto out_unlock;
335 } else if (sch->type == SCTP_CID_HEARTBEAT ||
336 sch->type == SCTP_CID_HEARTBEAT_ACK) {
337 if (ct->proto.sctp.vtag[dir] == 0) {
338 pr_debug("Setting vtag %x for dir %d\n",
339 sh->vtag, dir);
340 ct->proto.sctp.vtag[dir] = sh->vtag;
341 } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
342 pr_debug("Verification tag check failed\n");
343 goto out_unlock;
344 }
345 }
346
347 old_state = ct->proto.sctp.state;
348 new_state = sctp_new_state(dir, old_state, sch->type);
349
350 /* Invalid */
351 if (new_state == SCTP_CONNTRACK_MAX) {
352 pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
353 "conntrack=%u\n",
354 dir, sch->type, old_state);
355 goto out_unlock;
356 }
357
358 /* If it is an INIT or an INIT ACK note down the vtag */
359 if (sch->type == SCTP_CID_INIT ||
360 sch->type == SCTP_CID_INIT_ACK) {
361 struct sctp_inithdr _inithdr, *ih;
362
363 ih = skb_header_pointer(skb, offset + sizeof(_sch),
364 sizeof(_inithdr), &_inithdr);
365 if (ih == NULL)
366 goto out_unlock;
367 pr_debug("Setting vtag %x for dir %d\n",
368 ih->init_tag, !dir);
369 ct->proto.sctp.vtag[!dir] = ih->init_tag;
370 }
371
372 ct->proto.sctp.state = new_state;
373 if (old_state != new_state)
374 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
375 }
376 spin_unlock_bh(&ct->lock);
377
378 timeouts = nf_ct_timeout_lookup(ct);
379 if (!timeouts)
380 timeouts = sctp_pernet(nf_ct_net(ct))->timeouts;
381
382 nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
383
384 if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
385 dir == IP_CT_DIR_REPLY &&
386 new_state == SCTP_CONNTRACK_ESTABLISHED) {
387 pr_debug("Setting assured bit\n");
388 set_bit(IPS_ASSURED_BIT, &ct->status);
389 nf_conntrack_event_cache(IPCT_ASSURED, ct);
390 }
391
392 return NF_ACCEPT;
393
394 out_unlock:
395 spin_unlock_bh(&ct->lock);
396 out:
397 return -NF_ACCEPT;
398 }
399
400 /* Called when a new connection for this protocol found. */
sctp_new(struct nf_conn * ct,const struct sk_buff * skb,unsigned int dataoff)401 static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
402 unsigned int dataoff)
403 {
404 enum sctp_conntrack new_state;
405 const struct sctphdr *sh;
406 struct sctphdr _sctph;
407 const struct sctp_chunkhdr *sch;
408 struct sctp_chunkhdr _sch;
409 u_int32_t offset, count;
410 unsigned long map[256 / sizeof(unsigned long)] = { 0 };
411
412 sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
413 if (sh == NULL)
414 return false;
415
416 if (do_basic_checks(ct, skb, dataoff, map) != 0)
417 return false;
418
419 /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
420 if (test_bit(SCTP_CID_ABORT, map) ||
421 test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
422 test_bit(SCTP_CID_COOKIE_ACK, map))
423 return false;
424
425 memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
426 new_state = SCTP_CONNTRACK_MAX;
427 for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
428 /* Don't need lock here: this conntrack not in circulation yet */
429 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
430 SCTP_CONNTRACK_NONE, sch->type);
431
432 /* Invalid: delete conntrack */
433 if (new_state == SCTP_CONNTRACK_NONE ||
434 new_state == SCTP_CONNTRACK_MAX) {
435 pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
436 return false;
437 }
438
439 /* Copy the vtag into the state info */
440 if (sch->type == SCTP_CID_INIT) {
441 struct sctp_inithdr _inithdr, *ih;
442 /* Sec 8.5.1 (A) */
443 if (sh->vtag)
444 return false;
445
446 ih = skb_header_pointer(skb, offset + sizeof(_sch),
447 sizeof(_inithdr), &_inithdr);
448 if (!ih)
449 return false;
450
451 pr_debug("Setting vtag %x for new conn\n",
452 ih->init_tag);
453
454 ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
455 } else if (sch->type == SCTP_CID_HEARTBEAT) {
456 pr_debug("Setting vtag %x for secondary conntrack\n",
457 sh->vtag);
458 ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
459 }
460 /* If it is a shutdown ack OOTB packet, we expect a return
461 shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
462 else {
463 pr_debug("Setting vtag %x for new conn OOTB\n",
464 sh->vtag);
465 ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
466 }
467
468 ct->proto.sctp.state = new_state;
469 }
470
471 return true;
472 }
473
sctp_error(struct net * net,struct nf_conn * tpl,struct sk_buff * skb,unsigned int dataoff,u8 pf,unsigned int hooknum)474 static int sctp_error(struct net *net, struct nf_conn *tpl, struct sk_buff *skb,
475 unsigned int dataoff,
476 u8 pf, unsigned int hooknum)
477 {
478 const struct sctphdr *sh;
479 const char *logmsg;
480
481 if (skb->len < dataoff + sizeof(struct sctphdr)) {
482 logmsg = "nf_ct_sctp: short packet ";
483 goto out_invalid;
484 }
485 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
486 skb->ip_summed == CHECKSUM_NONE) {
487 if (!skb_make_writable(skb, dataoff + sizeof(struct sctphdr))) {
488 logmsg = "nf_ct_sctp: failed to read header ";
489 goto out_invalid;
490 }
491 sh = (const struct sctphdr *)(skb->data + dataoff);
492 if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
493 logmsg = "nf_ct_sctp: bad CRC ";
494 goto out_invalid;
495 }
496 skb->ip_summed = CHECKSUM_UNNECESSARY;
497 }
498 return NF_ACCEPT;
499 out_invalid:
500 nf_l4proto_log_invalid(skb, net, pf, IPPROTO_SCTP, "%s", logmsg);
501 return -NF_ACCEPT;
502 }
503
sctp_can_early_drop(const struct nf_conn * ct)504 static bool sctp_can_early_drop(const struct nf_conn *ct)
505 {
506 switch (ct->proto.sctp.state) {
507 case SCTP_CONNTRACK_SHUTDOWN_SENT:
508 case SCTP_CONNTRACK_SHUTDOWN_RECD:
509 case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
510 return true;
511 default:
512 break;
513 }
514
515 return false;
516 }
517
518 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
519
520 #include <linux/netfilter/nfnetlink.h>
521 #include <linux/netfilter/nfnetlink_conntrack.h>
522
sctp_to_nlattr(struct sk_buff * skb,struct nlattr * nla,struct nf_conn * ct)523 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
524 struct nf_conn *ct)
525 {
526 struct nlattr *nest_parms;
527
528 spin_lock_bh(&ct->lock);
529 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
530 if (!nest_parms)
531 goto nla_put_failure;
532
533 if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
534 nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
535 ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
536 nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
537 ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
538 goto nla_put_failure;
539
540 spin_unlock_bh(&ct->lock);
541
542 nla_nest_end(skb, nest_parms);
543
544 return 0;
545
546 nla_put_failure:
547 spin_unlock_bh(&ct->lock);
548 return -1;
549 }
550
551 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
552 [CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 },
553 [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 },
554 [CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 },
555 };
556
557 #define SCTP_NLATTR_SIZE ( \
558 NLA_ALIGN(NLA_HDRLEN + 1) + \
559 NLA_ALIGN(NLA_HDRLEN + 4) + \
560 NLA_ALIGN(NLA_HDRLEN + 4))
561
nlattr_to_sctp(struct nlattr * cda[],struct nf_conn * ct)562 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
563 {
564 struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
565 struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
566 int err;
567
568 /* updates may not contain the internal protocol info, skip parsing */
569 if (!attr)
570 return 0;
571
572 err = nla_parse_nested(tb, CTA_PROTOINFO_SCTP_MAX, attr,
573 sctp_nla_policy, NULL);
574 if (err < 0)
575 return err;
576
577 if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
578 !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
579 !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
580 return -EINVAL;
581
582 spin_lock_bh(&ct->lock);
583 ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
584 ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
585 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
586 ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
587 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
588 spin_unlock_bh(&ct->lock);
589
590 return 0;
591 }
592 #endif
593
594 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
595
596 #include <linux/netfilter/nfnetlink.h>
597 #include <linux/netfilter/nfnetlink_cttimeout.h>
598
sctp_timeout_nlattr_to_obj(struct nlattr * tb[],struct net * net,void * data)599 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
600 struct net *net, void *data)
601 {
602 unsigned int *timeouts = data;
603 struct nf_sctp_net *sn = sctp_pernet(net);
604 int i;
605
606 /* set default SCTP timeouts. */
607 for (i=0; i<SCTP_CONNTRACK_MAX; i++)
608 timeouts[i] = sn->timeouts[i];
609
610 /* there's a 1:1 mapping between attributes and protocol states. */
611 for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
612 if (tb[i]) {
613 timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
614 }
615 }
616
617 timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED];
618 return 0;
619 }
620
621 static int
sctp_timeout_obj_to_nlattr(struct sk_buff * skb,const void * data)622 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
623 {
624 const unsigned int *timeouts = data;
625 int i;
626
627 for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
628 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
629 goto nla_put_failure;
630 }
631 return 0;
632
633 nla_put_failure:
634 return -ENOSPC;
635 }
636
637 static const struct nla_policy
638 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
639 [CTA_TIMEOUT_SCTP_CLOSED] = { .type = NLA_U32 },
640 [CTA_TIMEOUT_SCTP_COOKIE_WAIT] = { .type = NLA_U32 },
641 [CTA_TIMEOUT_SCTP_COOKIE_ECHOED] = { .type = NLA_U32 },
642 [CTA_TIMEOUT_SCTP_ESTABLISHED] = { .type = NLA_U32 },
643 [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT] = { .type = NLA_U32 },
644 [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD] = { .type = NLA_U32 },
645 [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT] = { .type = NLA_U32 },
646 [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT] = { .type = NLA_U32 },
647 [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED] = { .type = NLA_U32 },
648 };
649 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
650
651
652 #ifdef CONFIG_SYSCTL
653 static struct ctl_table sctp_sysctl_table[] = {
654 {
655 .procname = "nf_conntrack_sctp_timeout_closed",
656 .maxlen = sizeof(unsigned int),
657 .mode = 0644,
658 .proc_handler = proc_dointvec_jiffies,
659 },
660 {
661 .procname = "nf_conntrack_sctp_timeout_cookie_wait",
662 .maxlen = sizeof(unsigned int),
663 .mode = 0644,
664 .proc_handler = proc_dointvec_jiffies,
665 },
666 {
667 .procname = "nf_conntrack_sctp_timeout_cookie_echoed",
668 .maxlen = sizeof(unsigned int),
669 .mode = 0644,
670 .proc_handler = proc_dointvec_jiffies,
671 },
672 {
673 .procname = "nf_conntrack_sctp_timeout_established",
674 .maxlen = sizeof(unsigned int),
675 .mode = 0644,
676 .proc_handler = proc_dointvec_jiffies,
677 },
678 {
679 .procname = "nf_conntrack_sctp_timeout_shutdown_sent",
680 .maxlen = sizeof(unsigned int),
681 .mode = 0644,
682 .proc_handler = proc_dointvec_jiffies,
683 },
684 {
685 .procname = "nf_conntrack_sctp_timeout_shutdown_recd",
686 .maxlen = sizeof(unsigned int),
687 .mode = 0644,
688 .proc_handler = proc_dointvec_jiffies,
689 },
690 {
691 .procname = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
692 .maxlen = sizeof(unsigned int),
693 .mode = 0644,
694 .proc_handler = proc_dointvec_jiffies,
695 },
696 {
697 .procname = "nf_conntrack_sctp_timeout_heartbeat_sent",
698 .maxlen = sizeof(unsigned int),
699 .mode = 0644,
700 .proc_handler = proc_dointvec_jiffies,
701 },
702 {
703 .procname = "nf_conntrack_sctp_timeout_heartbeat_acked",
704 .maxlen = sizeof(unsigned int),
705 .mode = 0644,
706 .proc_handler = proc_dointvec_jiffies,
707 },
708 { }
709 };
710 #endif
711
sctp_kmemdup_sysctl_table(struct nf_proto_net * pn,struct nf_sctp_net * sn)712 static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
713 struct nf_sctp_net *sn)
714 {
715 #ifdef CONFIG_SYSCTL
716 if (pn->ctl_table)
717 return 0;
718
719 pn->ctl_table = kmemdup(sctp_sysctl_table,
720 sizeof(sctp_sysctl_table),
721 GFP_KERNEL);
722 if (!pn->ctl_table)
723 return -ENOMEM;
724
725 pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
726 pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
727 pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
728 pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
729 pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
730 pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
731 pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
732 pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
733 pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
734 #endif
735 return 0;
736 }
737
sctp_init_net(struct net * net,u_int16_t proto)738 static int sctp_init_net(struct net *net, u_int16_t proto)
739 {
740 struct nf_sctp_net *sn = sctp_pernet(net);
741 struct nf_proto_net *pn = &sn->pn;
742
743 if (!pn->users) {
744 int i;
745
746 for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
747 sn->timeouts[i] = sctp_timeouts[i];
748
749 /* timeouts[0] is unused, init it so ->timeouts[0] contains
750 * 'new' timeout, like udp or icmp.
751 */
752 sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED];
753 }
754
755 return sctp_kmemdup_sysctl_table(pn, sn);
756 }
757
sctp_get_net_proto(struct net * net)758 static struct nf_proto_net *sctp_get_net_proto(struct net *net)
759 {
760 return &net->ct.nf_ct_proto.sctp.pn;
761 }
762
763 const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 = {
764 .l3proto = PF_INET,
765 .l4proto = IPPROTO_SCTP,
766 #ifdef CONFIG_NF_CONNTRACK_PROCFS
767 .print_conntrack = sctp_print_conntrack,
768 #endif
769 .packet = sctp_packet,
770 .new = sctp_new,
771 .error = sctp_error,
772 .can_early_drop = sctp_can_early_drop,
773 .me = THIS_MODULE,
774 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
775 .nlattr_size = SCTP_NLATTR_SIZE,
776 .to_nlattr = sctp_to_nlattr,
777 .from_nlattr = nlattr_to_sctp,
778 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
779 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
780 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
781 .nla_policy = nf_ct_port_nla_policy,
782 #endif
783 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
784 .ctnl_timeout = {
785 .nlattr_to_obj = sctp_timeout_nlattr_to_obj,
786 .obj_to_nlattr = sctp_timeout_obj_to_nlattr,
787 .nlattr_max = CTA_TIMEOUT_SCTP_MAX,
788 .obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
789 .nla_policy = sctp_timeout_nla_policy,
790 },
791 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
792 .init_net = sctp_init_net,
793 .get_net_proto = sctp_get_net_proto,
794 };
795 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp4);
796
797 const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 = {
798 .l3proto = PF_INET6,
799 .l4proto = IPPROTO_SCTP,
800 #ifdef CONFIG_NF_CONNTRACK_PROCFS
801 .print_conntrack = sctp_print_conntrack,
802 #endif
803 .packet = sctp_packet,
804 .new = sctp_new,
805 .error = sctp_error,
806 .can_early_drop = sctp_can_early_drop,
807 .me = THIS_MODULE,
808 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
809 .nlattr_size = SCTP_NLATTR_SIZE,
810 .to_nlattr = sctp_to_nlattr,
811 .from_nlattr = nlattr_to_sctp,
812 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
813 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
814 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
815 .nla_policy = nf_ct_port_nla_policy,
816 #endif
817 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
818 .ctnl_timeout = {
819 .nlattr_to_obj = sctp_timeout_nlattr_to_obj,
820 .obj_to_nlattr = sctp_timeout_obj_to_nlattr,
821 .nlattr_max = CTA_TIMEOUT_SCTP_MAX,
822 .obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
823 .nla_policy = sctp_timeout_nla_policy,
824 },
825 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
826 .init_net = sctp_init_net,
827 .get_net_proto = sctp_get_net_proto,
828 };
829 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp6);
830
