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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * xfrm_replay.c - xfrm replay detection, derived from xfrm_state.c.
4 *
5 * Copyright (C) 2010 secunet Security Networks AG
6 * Copyright (C) 2010 Steffen Klassert <steffen.klassert@secunet.com>
7 */
8
9#include <linux/export.h>
10#include <net/xfrm.h>
11
12u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq)
13{
14 u32 seq, seq_hi, bottom;
15 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
16
17 if (!(x->props.flags & XFRM_STATE_ESN))
18 return 0;
19
20 seq = ntohl(net_seq);
21 seq_hi = replay_esn->seq_hi;
22 bottom = replay_esn->seq - replay_esn->replay_window + 1;
23
24 if (likely(replay_esn->seq >= replay_esn->replay_window - 1)) {
25 /* A. same subspace */
26 if (unlikely(seq < bottom))
27 seq_hi++;
28 } else {
29 /* B. window spans two subspaces */
30 if (unlikely(seq >= bottom))
31 seq_hi--;
32 }
33
34 return seq_hi;
35}
36EXPORT_SYMBOL(xfrm_replay_seqhi);
37;
38static void xfrm_replay_notify(struct xfrm_state *x, int event)
39{
40 struct km_event c;
41 /* we send notify messages in case
42 * 1. we updated on of the sequence numbers, and the seqno difference
43 * is at least x->replay_maxdiff, in this case we also update the
44 * timeout of our timer function
45 * 2. if x->replay_maxage has elapsed since last update,
46 * and there were changes
47 *
48 * The state structure must be locked!
49 */
50
51 switch (event) {
52 case XFRM_REPLAY_UPDATE:
53 if (!x->replay_maxdiff ||
54 ((x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
55 (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff))) {
56 if (x->xflags & XFRM_TIME_DEFER)
57 event = XFRM_REPLAY_TIMEOUT;
58 else
59 return;
60 }
61
62 break;
63
64 case XFRM_REPLAY_TIMEOUT:
65 if (memcmp(&x->replay, &x->preplay,
66 sizeof(struct xfrm_replay_state)) == 0) {
67 x->xflags |= XFRM_TIME_DEFER;
68 return;
69 }
70
71 break;
72 }
73
74 memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state));
75 c.event = XFRM_MSG_NEWAE;
76 c.data.aevent = event;
77 km_state_notify(x, &c);
78
79 if (x->replay_maxage &&
80 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
81 x->xflags &= ~XFRM_TIME_DEFER;
82}
83
84static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
85{
86 int err = 0;
87 struct net *net = xs_net(x);
88
89 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
90 XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
91 XFRM_SKB_CB(skb)->seq.output.hi = 0;
92 if (unlikely(x->replay.oseq == 0)) {
93 x->replay.oseq--;
94 xfrm_audit_state_replay_overflow(x, skb);
95 err = -EOVERFLOW;
96
97 return err;
98 }
99 if (xfrm_aevent_is_on(net))
100 x->repl->notify(x, XFRM_REPLAY_UPDATE);
101 }
102
103 return err;
104}
105
106static int xfrm_replay_check(struct xfrm_state *x,
107 struct sk_buff *skb, __be32 net_seq)
108{
109 u32 diff;
110 u32 seq = ntohl(net_seq);
111
112 if (!x->props.replay_window)
113 return 0;
114
115 if (unlikely(seq == 0))
116 goto err;
117
118 if (likely(seq > x->replay.seq))
119 return 0;
120
121 diff = x->replay.seq - seq;
122 if (diff >= x->props.replay_window) {
123 x->stats.replay_window++;
124 goto err;
125 }
126
127 if (x->replay.bitmap & (1U << diff)) {
128 x->stats.replay++;
129 goto err;
130 }
131 return 0;
132
133err:
134 xfrm_audit_state_replay(x, skb, net_seq);
135 return -EINVAL;
136}
137
138static void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
139{
140 u32 diff;
141 u32 seq = ntohl(net_seq);
142
143 if (!x->props.replay_window)
144 return;
145
146 if (seq > x->replay.seq) {
147 diff = seq - x->replay.seq;
148 if (diff < x->props.replay_window)
149 x->replay.bitmap = ((x->replay.bitmap) << diff) | 1;
150 else
151 x->replay.bitmap = 1;
152 x->replay.seq = seq;
153 } else {
154 diff = x->replay.seq - seq;
155 x->replay.bitmap |= (1U << diff);
156 }
157
158 if (xfrm_aevent_is_on(xs_net(x)))
159 x->repl->notify(x, XFRM_REPLAY_UPDATE);
160}
161
162static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
163{
164 int err = 0;
165 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
166 struct net *net = xs_net(x);
167
168 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
169 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
170 XFRM_SKB_CB(skb)->seq.output.hi = 0;
171 if (unlikely(replay_esn->oseq == 0)) {
172 replay_esn->oseq--;
173 xfrm_audit_state_replay_overflow(x, skb);
174 err = -EOVERFLOW;
175
176 return err;
177 }
178 if (xfrm_aevent_is_on(net))
179 x->repl->notify(x, XFRM_REPLAY_UPDATE);
180 }
181
182 return err;
183}
184
185static int xfrm_replay_check_bmp(struct xfrm_state *x,
186 struct sk_buff *skb, __be32 net_seq)
187{
188 unsigned int bitnr, nr;
189 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
190 u32 pos;
191 u32 seq = ntohl(net_seq);
192 u32 diff = replay_esn->seq - seq;
193
194 if (!replay_esn->replay_window)
195 return 0;
196
197 if (unlikely(seq == 0))
198 goto err;
199
200 if (likely(seq > replay_esn->seq))
201 return 0;
202
203 if (diff >= replay_esn->replay_window) {
204 x->stats.replay_window++;
205 goto err;
206 }
207
208 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
209
210 if (pos >= diff)
211 bitnr = (pos - diff) % replay_esn->replay_window;
212 else
213 bitnr = replay_esn->replay_window - (diff - pos);
214
215 nr = bitnr >> 5;
216 bitnr = bitnr & 0x1F;
217 if (replay_esn->bmp[nr] & (1U << bitnr))
218 goto err_replay;
219
220 return 0;
221
222err_replay:
223 x->stats.replay++;
224err:
225 xfrm_audit_state_replay(x, skb, net_seq);
226 return -EINVAL;
227}
228
229static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq)
230{
231 unsigned int bitnr, nr, i;
232 u32 diff;
233 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
234 u32 seq = ntohl(net_seq);
235 u32 pos;
236
237 if (!replay_esn->replay_window)
238 return;
239
240 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
241
242 if (seq > replay_esn->seq) {
243 diff = seq - replay_esn->seq;
244
245 if (diff < replay_esn->replay_window) {
246 for (i = 1; i < diff; i++) {
247 bitnr = (pos + i) % replay_esn->replay_window;
248 nr = bitnr >> 5;
249 bitnr = bitnr & 0x1F;
250 replay_esn->bmp[nr] &= ~(1U << bitnr);
251 }
252 } else {
253 nr = (replay_esn->replay_window - 1) >> 5;
254 for (i = 0; i <= nr; i++)
255 replay_esn->bmp[i] = 0;
256 }
257
258 bitnr = (pos + diff) % replay_esn->replay_window;
259 replay_esn->seq = seq;
260 } else {
261 diff = replay_esn->seq - seq;
262
263 if (pos >= diff)
264 bitnr = (pos - diff) % replay_esn->replay_window;
265 else
266 bitnr = replay_esn->replay_window - (diff - pos);
267 }
268
269 nr = bitnr >> 5;
270 bitnr = bitnr & 0x1F;
271 replay_esn->bmp[nr] |= (1U << bitnr);
272
273 if (xfrm_aevent_is_on(xs_net(x)))
274 x->repl->notify(x, XFRM_REPLAY_UPDATE);
275}
276
277static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
278{
279 struct km_event c;
280 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
281 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
282
283 /* we send notify messages in case
284 * 1. we updated on of the sequence numbers, and the seqno difference
285 * is at least x->replay_maxdiff, in this case we also update the
286 * timeout of our timer function
287 * 2. if x->replay_maxage has elapsed since last update,
288 * and there were changes
289 *
290 * The state structure must be locked!
291 */
292
293 switch (event) {
294 case XFRM_REPLAY_UPDATE:
295 if (!x->replay_maxdiff ||
296 ((replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) &&
297 (replay_esn->oseq - preplay_esn->oseq
298 < x->replay_maxdiff))) {
299 if (x->xflags & XFRM_TIME_DEFER)
300 event = XFRM_REPLAY_TIMEOUT;
301 else
302 return;
303 }
304
305 break;
306
307 case XFRM_REPLAY_TIMEOUT:
308 if (memcmp(x->replay_esn, x->preplay_esn,
309 xfrm_replay_state_esn_len(replay_esn)) == 0) {
310 x->xflags |= XFRM_TIME_DEFER;
311 return;
312 }
313
314 break;
315 }
316
317 memcpy(x->preplay_esn, x->replay_esn,
318 xfrm_replay_state_esn_len(replay_esn));
319 c.event = XFRM_MSG_NEWAE;
320 c.data.aevent = event;
321 km_state_notify(x, &c);
322
323 if (x->replay_maxage &&
324 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
325 x->xflags &= ~XFRM_TIME_DEFER;
326}
327
328static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
329{
330 u32 seq_diff, oseq_diff;
331 struct km_event c;
332 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
333 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
334
335 /* we send notify messages in case
336 * 1. we updated on of the sequence numbers, and the seqno difference
337 * is at least x->replay_maxdiff, in this case we also update the
338 * timeout of our timer function
339 * 2. if x->replay_maxage has elapsed since last update,
340 * and there were changes
341 *
342 * The state structure must be locked!
343 */
344
345 switch (event) {
346 case XFRM_REPLAY_UPDATE:
347 if (x->replay_maxdiff) {
348 if (replay_esn->seq_hi == preplay_esn->seq_hi)
349 seq_diff = replay_esn->seq - preplay_esn->seq;
350 else
351 seq_diff = ~preplay_esn->seq + replay_esn->seq
352 + 1;
353
354 if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
355 oseq_diff = replay_esn->oseq
356 - preplay_esn->oseq;
357 else
358 oseq_diff = ~preplay_esn->oseq
359 + replay_esn->oseq + 1;
360
361 if (seq_diff >= x->replay_maxdiff ||
362 oseq_diff >= x->replay_maxdiff)
363 break;
364 }
365
366 if (x->xflags & XFRM_TIME_DEFER)
367 event = XFRM_REPLAY_TIMEOUT;
368 else
369 return;
370
371 break;
372
373 case XFRM_REPLAY_TIMEOUT:
374 if (memcmp(x->replay_esn, x->preplay_esn,
375 xfrm_replay_state_esn_len(replay_esn)) == 0) {
376 x->xflags |= XFRM_TIME_DEFER;
377 return;
378 }
379
380 break;
381 }
382
383 memcpy(x->preplay_esn, x->replay_esn,
384 xfrm_replay_state_esn_len(replay_esn));
385 c.event = XFRM_MSG_NEWAE;
386 c.data.aevent = event;
387 km_state_notify(x, &c);
388
389 if (x->replay_maxage &&
390 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
391 x->xflags &= ~XFRM_TIME_DEFER;
392}
393
394static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
395{
396 int err = 0;
397 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
398 struct net *net = xs_net(x);
399
400 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
401 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
402 XFRM_SKB_CB(skb)->seq.output.hi = replay_esn->oseq_hi;
403
404 if (unlikely(replay_esn->oseq == 0)) {
405 XFRM_SKB_CB(skb)->seq.output.hi = ++replay_esn->oseq_hi;
406
407 if (replay_esn->oseq_hi == 0) {
408 replay_esn->oseq--;
409 replay_esn->oseq_hi--;
410 xfrm_audit_state_replay_overflow(x, skb);
411 err = -EOVERFLOW;
412
413 return err;
414 }
415 }
416 if (xfrm_aevent_is_on(net))
417 x->repl->notify(x, XFRM_REPLAY_UPDATE);
418 }
419
420 return err;
421}
422
423static int xfrm_replay_check_esn(struct xfrm_state *x,
424 struct sk_buff *skb, __be32 net_seq)
425{
426 unsigned int bitnr, nr;
427 u32 diff;
428 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
429 u32 pos;
430 u32 seq = ntohl(net_seq);
431 u32 wsize = replay_esn->replay_window;
432 u32 top = replay_esn->seq;
433 u32 bottom = top - wsize + 1;
434
435 if (!wsize)
436 return 0;
437
438 if (unlikely(seq == 0 && replay_esn->seq_hi == 0 &&
439 (replay_esn->seq < replay_esn->replay_window - 1)))
440 goto err;
441
442 diff = top - seq;
443
444 if (likely(top >= wsize - 1)) {
445 /* A. same subspace */
446 if (likely(seq > top) || seq < bottom)
447 return 0;
448 } else {
449 /* B. window spans two subspaces */
450 if (likely(seq > top && seq < bottom))
451 return 0;
452 if (seq >= bottom)
453 diff = ~seq + top + 1;
454 }
455
456 if (diff >= replay_esn->replay_window) {
457 x->stats.replay_window++;
458 goto err;
459 }
460
461 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
462
463 if (pos >= diff)
464 bitnr = (pos - diff) % replay_esn->replay_window;
465 else
466 bitnr = replay_esn->replay_window - (diff - pos);
467
468 nr = bitnr >> 5;
469 bitnr = bitnr & 0x1F;
470 if (replay_esn->bmp[nr] & (1U << bitnr))
471 goto err_replay;
472
473 return 0;
474
475err_replay:
476 x->stats.replay++;
477err:
478 xfrm_audit_state_replay(x, skb, net_seq);
479 return -EINVAL;
480}
481
482static int xfrm_replay_recheck_esn(struct xfrm_state *x,
483 struct sk_buff *skb, __be32 net_seq)
484{
485 if (unlikely(XFRM_SKB_CB(skb)->seq.input.hi !=
486 htonl(xfrm_replay_seqhi(x, net_seq)))) {
487 x->stats.replay_window++;
488 return -EINVAL;
489 }
490
491 return xfrm_replay_check_esn(x, skb, net_seq);
492}
493
494static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
495{
496 unsigned int bitnr, nr, i;
497 int wrap;
498 u32 diff, pos, seq, seq_hi;
499 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
500
501 if (!replay_esn->replay_window)
502 return;
503
504 seq = ntohl(net_seq);
505 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
506 seq_hi = xfrm_replay_seqhi(x, net_seq);
507 wrap = seq_hi - replay_esn->seq_hi;
508
509 if ((!wrap && seq > replay_esn->seq) || wrap > 0) {
510 if (likely(!wrap))
511 diff = seq - replay_esn->seq;
512 else
513 diff = ~replay_esn->seq + seq + 1;
514
515 if (diff < replay_esn->replay_window) {
516 for (i = 1; i < diff; i++) {
517 bitnr = (pos + i) % replay_esn->replay_window;
518 nr = bitnr >> 5;
519 bitnr = bitnr & 0x1F;
520 replay_esn->bmp[nr] &= ~(1U << bitnr);
521 }
522 } else {
523 nr = (replay_esn->replay_window - 1) >> 5;
524 for (i = 0; i <= nr; i++)
525 replay_esn->bmp[i] = 0;
526 }
527
528 bitnr = (pos + diff) % replay_esn->replay_window;
529 replay_esn->seq = seq;
530
531 if (unlikely(wrap > 0))
532 replay_esn->seq_hi++;
533 } else {
534 diff = replay_esn->seq - seq;
535
536 if (pos >= diff)
537 bitnr = (pos - diff) % replay_esn->replay_window;
538 else
539 bitnr = replay_esn->replay_window - (diff - pos);
540 }
541
542 xfrm_dev_state_advance_esn(x);
543
544 nr = bitnr >> 5;
545 bitnr = bitnr & 0x1F;
546 replay_esn->bmp[nr] |= (1U << bitnr);
547
548 if (xfrm_aevent_is_on(xs_net(x)))
549 x->repl->notify(x, XFRM_REPLAY_UPDATE);
550}
551
552#ifdef CONFIG_XFRM_OFFLOAD
553static int xfrm_replay_overflow_offload(struct xfrm_state *x, struct sk_buff *skb)
554{
555 int err = 0;
556 struct net *net = xs_net(x);
557 struct xfrm_offload *xo = xfrm_offload(skb);
558 __u32 oseq = x->replay.oseq;
559
560 if (!xo)
561 return xfrm_replay_overflow(x, skb);
562
563 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
564 if (!skb_is_gso(skb)) {
565 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
566 xo->seq.low = oseq;
567 } else {
568 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
569 xo->seq.low = oseq + 1;
570 oseq += skb_shinfo(skb)->gso_segs;
571 }
572
573 XFRM_SKB_CB(skb)->seq.output.hi = 0;
574 xo->seq.hi = 0;
575 if (unlikely(oseq < x->replay.oseq)) {
576 xfrm_audit_state_replay_overflow(x, skb);
577 err = -EOVERFLOW;
578
579 return err;
580 }
581
582 x->replay.oseq = oseq;
583
584 if (xfrm_aevent_is_on(net))
585 x->repl->notify(x, XFRM_REPLAY_UPDATE);
586 }
587
588 return err;
589}
590
591static int xfrm_replay_overflow_offload_bmp(struct xfrm_state *x, struct sk_buff *skb)
592{
593 int err = 0;
594 struct xfrm_offload *xo = xfrm_offload(skb);
595 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
596 struct net *net = xs_net(x);
597 __u32 oseq = replay_esn->oseq;
598
599 if (!xo)
600 return xfrm_replay_overflow_bmp(x, skb);
601
602 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
603 if (!skb_is_gso(skb)) {
604 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
605 xo->seq.low = oseq;
606 } else {
607 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
608 xo->seq.low = oseq + 1;
609 oseq += skb_shinfo(skb)->gso_segs;
610 }
611
612 XFRM_SKB_CB(skb)->seq.output.hi = 0;
613 xo->seq.hi = 0;
614 if (unlikely(oseq < replay_esn->oseq)) {
615 xfrm_audit_state_replay_overflow(x, skb);
616 err = -EOVERFLOW;
617
618 return err;
619 } else {
620 replay_esn->oseq = oseq;
621 }
622
623 if (xfrm_aevent_is_on(net))
624 x->repl->notify(x, XFRM_REPLAY_UPDATE);
625 }
626
627 return err;
628}
629
630static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff *skb)
631{
632 int err = 0;
633 struct xfrm_offload *xo = xfrm_offload(skb);
634 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
635 struct net *net = xs_net(x);
636 __u32 oseq = replay_esn->oseq;
637 __u32 oseq_hi = replay_esn->oseq_hi;
638
639 if (!xo)
640 return xfrm_replay_overflow_esn(x, skb);
641
642 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
643 if (!skb_is_gso(skb)) {
644 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
645 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
646 xo->seq.low = oseq;
647 xo->seq.hi = oseq_hi;
648 } else {
649 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
650 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
651 xo->seq.low = oseq + 1;
652 xo->seq.hi = oseq_hi;
653 oseq += skb_shinfo(skb)->gso_segs;
654 }
655
656 if (unlikely(oseq < replay_esn->oseq)) {
657 XFRM_SKB_CB(skb)->seq.output.hi = ++oseq_hi;
658 xo->seq.hi = oseq_hi;
659 replay_esn->oseq_hi = oseq_hi;
660 if (replay_esn->oseq_hi == 0) {
661 replay_esn->oseq--;
662 replay_esn->oseq_hi--;
663 xfrm_audit_state_replay_overflow(x, skb);
664 err = -EOVERFLOW;
665
666 return err;
667 }
668 }
669
670 replay_esn->oseq = oseq;
671
672 if (xfrm_aevent_is_on(net))
673 x->repl->notify(x, XFRM_REPLAY_UPDATE);
674 }
675
676 return err;
677}
678
679static const struct xfrm_replay xfrm_replay_legacy = {
680 .advance = xfrm_replay_advance,
681 .check = xfrm_replay_check,
682 .recheck = xfrm_replay_check,
683 .notify = xfrm_replay_notify,
684 .overflow = xfrm_replay_overflow_offload,
685};
686
687static const struct xfrm_replay xfrm_replay_bmp = {
688 .advance = xfrm_replay_advance_bmp,
689 .check = xfrm_replay_check_bmp,
690 .recheck = xfrm_replay_check_bmp,
691 .notify = xfrm_replay_notify_bmp,
692 .overflow = xfrm_replay_overflow_offload_bmp,
693};
694
695static const struct xfrm_replay xfrm_replay_esn = {
696 .advance = xfrm_replay_advance_esn,
697 .check = xfrm_replay_check_esn,
698 .recheck = xfrm_replay_recheck_esn,
699 .notify = xfrm_replay_notify_esn,
700 .overflow = xfrm_replay_overflow_offload_esn,
701};
702#else
703static const struct xfrm_replay xfrm_replay_legacy = {
704 .advance = xfrm_replay_advance,
705 .check = xfrm_replay_check,
706 .recheck = xfrm_replay_check,
707 .notify = xfrm_replay_notify,
708 .overflow = xfrm_replay_overflow,
709};
710
711static const struct xfrm_replay xfrm_replay_bmp = {
712 .advance = xfrm_replay_advance_bmp,
713 .check = xfrm_replay_check_bmp,
714 .recheck = xfrm_replay_check_bmp,
715 .notify = xfrm_replay_notify_bmp,
716 .overflow = xfrm_replay_overflow_bmp,
717};
718
719static const struct xfrm_replay xfrm_replay_esn = {
720 .advance = xfrm_replay_advance_esn,
721 .check = xfrm_replay_check_esn,
722 .recheck = xfrm_replay_recheck_esn,
723 .notify = xfrm_replay_notify_esn,
724 .overflow = xfrm_replay_overflow_esn,
725};
726#endif
727
728int xfrm_init_replay(struct xfrm_state *x)
729{
730 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
731
732 if (replay_esn) {
733 if (replay_esn->replay_window >
734 replay_esn->bmp_len * sizeof(__u32) * 8)
735 return -EINVAL;
736
737 if (x->props.flags & XFRM_STATE_ESN) {
738 if (replay_esn->replay_window == 0)
739 return -EINVAL;
740 x->repl = &xfrm_replay_esn;
741 } else {
742 x->repl = &xfrm_replay_bmp;
743 }
744 } else {
745 x->repl = &xfrm_replay_legacy;
746 }
747
748 return 0;
749}
750EXPORT_SYMBOL(xfrm_init_replay);
1/*
2 * xfrm_replay.c - xfrm replay detection, derived from xfrm_state.c.
3 *
4 * Copyright (C) 2010 secunet Security Networks AG
5 * Copyright (C) 2010 Steffen Klassert <steffen.klassert@secunet.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21#include <linux/export.h>
22#include <net/xfrm.h>
23
24u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq)
25{
26 u32 seq, seq_hi, bottom;
27 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
28
29 if (!(x->props.flags & XFRM_STATE_ESN))
30 return 0;
31
32 seq = ntohl(net_seq);
33 seq_hi = replay_esn->seq_hi;
34 bottom = replay_esn->seq - replay_esn->replay_window + 1;
35
36 if (likely(replay_esn->seq >= replay_esn->replay_window - 1)) {
37 /* A. same subspace */
38 if (unlikely(seq < bottom))
39 seq_hi++;
40 } else {
41 /* B. window spans two subspaces */
42 if (unlikely(seq >= bottom))
43 seq_hi--;
44 }
45
46 return seq_hi;
47}
48EXPORT_SYMBOL(xfrm_replay_seqhi);
49;
50static void xfrm_replay_notify(struct xfrm_state *x, int event)
51{
52 struct km_event c;
53 /* we send notify messages in case
54 * 1. we updated on of the sequence numbers, and the seqno difference
55 * is at least x->replay_maxdiff, in this case we also update the
56 * timeout of our timer function
57 * 2. if x->replay_maxage has elapsed since last update,
58 * and there were changes
59 *
60 * The state structure must be locked!
61 */
62
63 switch (event) {
64 case XFRM_REPLAY_UPDATE:
65 if (!x->replay_maxdiff ||
66 ((x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
67 (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff))) {
68 if (x->xflags & XFRM_TIME_DEFER)
69 event = XFRM_REPLAY_TIMEOUT;
70 else
71 return;
72 }
73
74 break;
75
76 case XFRM_REPLAY_TIMEOUT:
77 if (memcmp(&x->replay, &x->preplay,
78 sizeof(struct xfrm_replay_state)) == 0) {
79 x->xflags |= XFRM_TIME_DEFER;
80 return;
81 }
82
83 break;
84 }
85
86 memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state));
87 c.event = XFRM_MSG_NEWAE;
88 c.data.aevent = event;
89 km_state_notify(x, &c);
90
91 if (x->replay_maxage &&
92 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
93 x->xflags &= ~XFRM_TIME_DEFER;
94}
95
96static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
97{
98 int err = 0;
99 struct net *net = xs_net(x);
100
101 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
102 XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
103 XFRM_SKB_CB(skb)->seq.output.hi = 0;
104 if (unlikely(x->replay.oseq == 0)) {
105 x->replay.oseq--;
106 xfrm_audit_state_replay_overflow(x, skb);
107 err = -EOVERFLOW;
108
109 return err;
110 }
111 if (xfrm_aevent_is_on(net))
112 x->repl->notify(x, XFRM_REPLAY_UPDATE);
113 }
114
115 return err;
116}
117
118static int xfrm_replay_check(struct xfrm_state *x,
119 struct sk_buff *skb, __be32 net_seq)
120{
121 u32 diff;
122 u32 seq = ntohl(net_seq);
123
124 if (!x->props.replay_window)
125 return 0;
126
127 if (unlikely(seq == 0))
128 goto err;
129
130 if (likely(seq > x->replay.seq))
131 return 0;
132
133 diff = x->replay.seq - seq;
134 if (diff >= x->props.replay_window) {
135 x->stats.replay_window++;
136 goto err;
137 }
138
139 if (x->replay.bitmap & (1U << diff)) {
140 x->stats.replay++;
141 goto err;
142 }
143 return 0;
144
145err:
146 xfrm_audit_state_replay(x, skb, net_seq);
147 return -EINVAL;
148}
149
150static void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
151{
152 u32 diff;
153 u32 seq = ntohl(net_seq);
154
155 if (!x->props.replay_window)
156 return;
157
158 if (seq > x->replay.seq) {
159 diff = seq - x->replay.seq;
160 if (diff < x->props.replay_window)
161 x->replay.bitmap = ((x->replay.bitmap) << diff) | 1;
162 else
163 x->replay.bitmap = 1;
164 x->replay.seq = seq;
165 } else {
166 diff = x->replay.seq - seq;
167 x->replay.bitmap |= (1U << diff);
168 }
169
170 if (xfrm_aevent_is_on(xs_net(x)))
171 x->repl->notify(x, XFRM_REPLAY_UPDATE);
172}
173
174static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
175{
176 int err = 0;
177 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
178 struct net *net = xs_net(x);
179
180 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
181 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
182 XFRM_SKB_CB(skb)->seq.output.hi = 0;
183 if (unlikely(replay_esn->oseq == 0)) {
184 replay_esn->oseq--;
185 xfrm_audit_state_replay_overflow(x, skb);
186 err = -EOVERFLOW;
187
188 return err;
189 }
190 if (xfrm_aevent_is_on(net))
191 x->repl->notify(x, XFRM_REPLAY_UPDATE);
192 }
193
194 return err;
195}
196
197static int xfrm_replay_check_bmp(struct xfrm_state *x,
198 struct sk_buff *skb, __be32 net_seq)
199{
200 unsigned int bitnr, nr;
201 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
202 u32 pos;
203 u32 seq = ntohl(net_seq);
204 u32 diff = replay_esn->seq - seq;
205
206 if (!replay_esn->replay_window)
207 return 0;
208
209 if (unlikely(seq == 0))
210 goto err;
211
212 if (likely(seq > replay_esn->seq))
213 return 0;
214
215 if (diff >= replay_esn->replay_window) {
216 x->stats.replay_window++;
217 goto err;
218 }
219
220 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
221
222 if (pos >= diff)
223 bitnr = (pos - diff) % replay_esn->replay_window;
224 else
225 bitnr = replay_esn->replay_window - (diff - pos);
226
227 nr = bitnr >> 5;
228 bitnr = bitnr & 0x1F;
229 if (replay_esn->bmp[nr] & (1U << bitnr))
230 goto err_replay;
231
232 return 0;
233
234err_replay:
235 x->stats.replay++;
236err:
237 xfrm_audit_state_replay(x, skb, net_seq);
238 return -EINVAL;
239}
240
241static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq)
242{
243 unsigned int bitnr, nr, i;
244 u32 diff;
245 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
246 u32 seq = ntohl(net_seq);
247 u32 pos;
248
249 if (!replay_esn->replay_window)
250 return;
251
252 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
253
254 if (seq > replay_esn->seq) {
255 diff = seq - replay_esn->seq;
256
257 if (diff < replay_esn->replay_window) {
258 for (i = 1; i < diff; i++) {
259 bitnr = (pos + i) % replay_esn->replay_window;
260 nr = bitnr >> 5;
261 bitnr = bitnr & 0x1F;
262 replay_esn->bmp[nr] &= ~(1U << bitnr);
263 }
264 } else {
265 nr = (replay_esn->replay_window - 1) >> 5;
266 for (i = 0; i <= nr; i++)
267 replay_esn->bmp[i] = 0;
268 }
269
270 bitnr = (pos + diff) % replay_esn->replay_window;
271 replay_esn->seq = seq;
272 } else {
273 diff = replay_esn->seq - seq;
274
275 if (pos >= diff)
276 bitnr = (pos - diff) % replay_esn->replay_window;
277 else
278 bitnr = replay_esn->replay_window - (diff - pos);
279 }
280
281 nr = bitnr >> 5;
282 bitnr = bitnr & 0x1F;
283 replay_esn->bmp[nr] |= (1U << bitnr);
284
285 if (xfrm_aevent_is_on(xs_net(x)))
286 x->repl->notify(x, XFRM_REPLAY_UPDATE);
287}
288
289static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
290{
291 struct km_event c;
292 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
293 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
294
295 /* we send notify messages in case
296 * 1. we updated on of the sequence numbers, and the seqno difference
297 * is at least x->replay_maxdiff, in this case we also update the
298 * timeout of our timer function
299 * 2. if x->replay_maxage has elapsed since last update,
300 * and there were changes
301 *
302 * The state structure must be locked!
303 */
304
305 switch (event) {
306 case XFRM_REPLAY_UPDATE:
307 if (!x->replay_maxdiff ||
308 ((replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) &&
309 (replay_esn->oseq - preplay_esn->oseq
310 < x->replay_maxdiff))) {
311 if (x->xflags & XFRM_TIME_DEFER)
312 event = XFRM_REPLAY_TIMEOUT;
313 else
314 return;
315 }
316
317 break;
318
319 case XFRM_REPLAY_TIMEOUT:
320 if (memcmp(x->replay_esn, x->preplay_esn,
321 xfrm_replay_state_esn_len(replay_esn)) == 0) {
322 x->xflags |= XFRM_TIME_DEFER;
323 return;
324 }
325
326 break;
327 }
328
329 memcpy(x->preplay_esn, x->replay_esn,
330 xfrm_replay_state_esn_len(replay_esn));
331 c.event = XFRM_MSG_NEWAE;
332 c.data.aevent = event;
333 km_state_notify(x, &c);
334
335 if (x->replay_maxage &&
336 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
337 x->xflags &= ~XFRM_TIME_DEFER;
338}
339
340static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
341{
342 u32 seq_diff, oseq_diff;
343 struct km_event c;
344 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
345 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
346
347 /* we send notify messages in case
348 * 1. we updated on of the sequence numbers, and the seqno difference
349 * is at least x->replay_maxdiff, in this case we also update the
350 * timeout of our timer function
351 * 2. if x->replay_maxage has elapsed since last update,
352 * and there were changes
353 *
354 * The state structure must be locked!
355 */
356
357 switch (event) {
358 case XFRM_REPLAY_UPDATE:
359 if (x->replay_maxdiff) {
360 if (replay_esn->seq_hi == preplay_esn->seq_hi)
361 seq_diff = replay_esn->seq - preplay_esn->seq;
362 else
363 seq_diff = ~preplay_esn->seq + replay_esn->seq
364 + 1;
365
366 if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
367 oseq_diff = replay_esn->oseq
368 - preplay_esn->oseq;
369 else
370 oseq_diff = ~preplay_esn->oseq
371 + replay_esn->oseq + 1;
372
373 if (seq_diff >= x->replay_maxdiff ||
374 oseq_diff >= x->replay_maxdiff)
375 break;
376 }
377
378 if (x->xflags & XFRM_TIME_DEFER)
379 event = XFRM_REPLAY_TIMEOUT;
380 else
381 return;
382
383 break;
384
385 case XFRM_REPLAY_TIMEOUT:
386 if (memcmp(x->replay_esn, x->preplay_esn,
387 xfrm_replay_state_esn_len(replay_esn)) == 0) {
388 x->xflags |= XFRM_TIME_DEFER;
389 return;
390 }
391
392 break;
393 }
394
395 memcpy(x->preplay_esn, x->replay_esn,
396 xfrm_replay_state_esn_len(replay_esn));
397 c.event = XFRM_MSG_NEWAE;
398 c.data.aevent = event;
399 km_state_notify(x, &c);
400
401 if (x->replay_maxage &&
402 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
403 x->xflags &= ~XFRM_TIME_DEFER;
404}
405
406static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
407{
408 int err = 0;
409 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
410 struct net *net = xs_net(x);
411
412 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
413 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
414 XFRM_SKB_CB(skb)->seq.output.hi = replay_esn->oseq_hi;
415
416 if (unlikely(replay_esn->oseq == 0)) {
417 XFRM_SKB_CB(skb)->seq.output.hi = ++replay_esn->oseq_hi;
418
419 if (replay_esn->oseq_hi == 0) {
420 replay_esn->oseq--;
421 replay_esn->oseq_hi--;
422 xfrm_audit_state_replay_overflow(x, skb);
423 err = -EOVERFLOW;
424
425 return err;
426 }
427 }
428 if (xfrm_aevent_is_on(net))
429 x->repl->notify(x, XFRM_REPLAY_UPDATE);
430 }
431
432 return err;
433}
434
435static int xfrm_replay_check_esn(struct xfrm_state *x,
436 struct sk_buff *skb, __be32 net_seq)
437{
438 unsigned int bitnr, nr;
439 u32 diff;
440 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
441 u32 pos;
442 u32 seq = ntohl(net_seq);
443 u32 wsize = replay_esn->replay_window;
444 u32 top = replay_esn->seq;
445 u32 bottom = top - wsize + 1;
446
447 if (!wsize)
448 return 0;
449
450 if (unlikely(seq == 0 && replay_esn->seq_hi == 0 &&
451 (replay_esn->seq < replay_esn->replay_window - 1)))
452 goto err;
453
454 diff = top - seq;
455
456 if (likely(top >= wsize - 1)) {
457 /* A. same subspace */
458 if (likely(seq > top) || seq < bottom)
459 return 0;
460 } else {
461 /* B. window spans two subspaces */
462 if (likely(seq > top && seq < bottom))
463 return 0;
464 if (seq >= bottom)
465 diff = ~seq + top + 1;
466 }
467
468 if (diff >= replay_esn->replay_window) {
469 x->stats.replay_window++;
470 goto err;
471 }
472
473 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
474
475 if (pos >= diff)
476 bitnr = (pos - diff) % replay_esn->replay_window;
477 else
478 bitnr = replay_esn->replay_window - (diff - pos);
479
480 nr = bitnr >> 5;
481 bitnr = bitnr & 0x1F;
482 if (replay_esn->bmp[nr] & (1U << bitnr))
483 goto err_replay;
484
485 return 0;
486
487err_replay:
488 x->stats.replay++;
489err:
490 xfrm_audit_state_replay(x, skb, net_seq);
491 return -EINVAL;
492}
493
494static int xfrm_replay_recheck_esn(struct xfrm_state *x,
495 struct sk_buff *skb, __be32 net_seq)
496{
497 if (unlikely(XFRM_SKB_CB(skb)->seq.input.hi !=
498 htonl(xfrm_replay_seqhi(x, net_seq)))) {
499 x->stats.replay_window++;
500 return -EINVAL;
501 }
502
503 return xfrm_replay_check_esn(x, skb, net_seq);
504}
505
506static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
507{
508 unsigned int bitnr, nr, i;
509 int wrap;
510 u32 diff, pos, seq, seq_hi;
511 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
512
513 if (!replay_esn->replay_window)
514 return;
515
516 seq = ntohl(net_seq);
517 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
518 seq_hi = xfrm_replay_seqhi(x, net_seq);
519 wrap = seq_hi - replay_esn->seq_hi;
520
521 if ((!wrap && seq > replay_esn->seq) || wrap > 0) {
522 if (likely(!wrap))
523 diff = seq - replay_esn->seq;
524 else
525 diff = ~replay_esn->seq + seq + 1;
526
527 if (diff < replay_esn->replay_window) {
528 for (i = 1; i < diff; i++) {
529 bitnr = (pos + i) % replay_esn->replay_window;
530 nr = bitnr >> 5;
531 bitnr = bitnr & 0x1F;
532 replay_esn->bmp[nr] &= ~(1U << bitnr);
533 }
534 } else {
535 nr = (replay_esn->replay_window - 1) >> 5;
536 for (i = 0; i <= nr; i++)
537 replay_esn->bmp[i] = 0;
538 }
539
540 bitnr = (pos + diff) % replay_esn->replay_window;
541 replay_esn->seq = seq;
542
543 if (unlikely(wrap > 0))
544 replay_esn->seq_hi++;
545 } else {
546 diff = replay_esn->seq - seq;
547
548 if (pos >= diff)
549 bitnr = (pos - diff) % replay_esn->replay_window;
550 else
551 bitnr = replay_esn->replay_window - (diff - pos);
552 }
553
554 xfrm_dev_state_advance_esn(x);
555
556 nr = bitnr >> 5;
557 bitnr = bitnr & 0x1F;
558 replay_esn->bmp[nr] |= (1U << bitnr);
559
560 if (xfrm_aevent_is_on(xs_net(x)))
561 x->repl->notify(x, XFRM_REPLAY_UPDATE);
562}
563
564#ifdef CONFIG_XFRM_OFFLOAD
565static int xfrm_replay_overflow_offload(struct xfrm_state *x, struct sk_buff *skb)
566{
567 int err = 0;
568 struct net *net = xs_net(x);
569 struct xfrm_offload *xo = xfrm_offload(skb);
570 __u32 oseq = x->replay.oseq;
571
572 if (!xo)
573 return xfrm_replay_overflow(x, skb);
574
575 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
576 if (!skb_is_gso(skb)) {
577 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
578 xo->seq.low = oseq;
579 } else {
580 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
581 xo->seq.low = oseq + 1;
582 oseq += skb_shinfo(skb)->gso_segs;
583 }
584
585 XFRM_SKB_CB(skb)->seq.output.hi = 0;
586 xo->seq.hi = 0;
587 if (unlikely(oseq < x->replay.oseq)) {
588 xfrm_audit_state_replay_overflow(x, skb);
589 err = -EOVERFLOW;
590
591 return err;
592 }
593
594 x->replay.oseq = oseq;
595
596 if (xfrm_aevent_is_on(net))
597 x->repl->notify(x, XFRM_REPLAY_UPDATE);
598 }
599
600 return err;
601}
602
603static int xfrm_replay_overflow_offload_bmp(struct xfrm_state *x, struct sk_buff *skb)
604{
605 int err = 0;
606 struct xfrm_offload *xo = xfrm_offload(skb);
607 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
608 struct net *net = xs_net(x);
609 __u32 oseq = replay_esn->oseq;
610
611 if (!xo)
612 return xfrm_replay_overflow_bmp(x, skb);
613
614 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
615 if (!skb_is_gso(skb)) {
616 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
617 xo->seq.low = oseq;
618 } else {
619 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
620 xo->seq.low = oseq + 1;
621 oseq += skb_shinfo(skb)->gso_segs;
622 }
623
624 XFRM_SKB_CB(skb)->seq.output.hi = 0;
625 xo->seq.hi = 0;
626 if (unlikely(oseq < replay_esn->oseq)) {
627 xfrm_audit_state_replay_overflow(x, skb);
628 err = -EOVERFLOW;
629
630 return err;
631 } else {
632 replay_esn->oseq = oseq;
633 }
634
635 if (xfrm_aevent_is_on(net))
636 x->repl->notify(x, XFRM_REPLAY_UPDATE);
637 }
638
639 return err;
640}
641
642static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff *skb)
643{
644 int err = 0;
645 struct xfrm_offload *xo = xfrm_offload(skb);
646 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
647 struct net *net = xs_net(x);
648 __u32 oseq = replay_esn->oseq;
649 __u32 oseq_hi = replay_esn->oseq_hi;
650
651 if (!xo)
652 return xfrm_replay_overflow_esn(x, skb);
653
654 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
655 if (!skb_is_gso(skb)) {
656 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
657 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
658 xo->seq.low = oseq;
659 xo->seq.hi = oseq_hi;
660 } else {
661 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
662 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
663 xo->seq.low = oseq + 1;
664 xo->seq.hi = oseq_hi;
665 oseq += skb_shinfo(skb)->gso_segs;
666 }
667
668 if (unlikely(oseq < replay_esn->oseq)) {
669 XFRM_SKB_CB(skb)->seq.output.hi = ++oseq_hi;
670 xo->seq.hi = oseq_hi;
671 replay_esn->oseq_hi = oseq_hi;
672 if (replay_esn->oseq_hi == 0) {
673 replay_esn->oseq--;
674 replay_esn->oseq_hi--;
675 xfrm_audit_state_replay_overflow(x, skb);
676 err = -EOVERFLOW;
677
678 return err;
679 }
680 }
681
682 replay_esn->oseq = oseq;
683
684 if (xfrm_aevent_is_on(net))
685 x->repl->notify(x, XFRM_REPLAY_UPDATE);
686 }
687
688 return err;
689}
690
691static const struct xfrm_replay xfrm_replay_legacy = {
692 .advance = xfrm_replay_advance,
693 .check = xfrm_replay_check,
694 .recheck = xfrm_replay_check,
695 .notify = xfrm_replay_notify,
696 .overflow = xfrm_replay_overflow_offload,
697};
698
699static const struct xfrm_replay xfrm_replay_bmp = {
700 .advance = xfrm_replay_advance_bmp,
701 .check = xfrm_replay_check_bmp,
702 .recheck = xfrm_replay_check_bmp,
703 .notify = xfrm_replay_notify_bmp,
704 .overflow = xfrm_replay_overflow_offload_bmp,
705};
706
707static const struct xfrm_replay xfrm_replay_esn = {
708 .advance = xfrm_replay_advance_esn,
709 .check = xfrm_replay_check_esn,
710 .recheck = xfrm_replay_recheck_esn,
711 .notify = xfrm_replay_notify_esn,
712 .overflow = xfrm_replay_overflow_offload_esn,
713};
714#else
715static const struct xfrm_replay xfrm_replay_legacy = {
716 .advance = xfrm_replay_advance,
717 .check = xfrm_replay_check,
718 .recheck = xfrm_replay_check,
719 .notify = xfrm_replay_notify,
720 .overflow = xfrm_replay_overflow,
721};
722
723static const struct xfrm_replay xfrm_replay_bmp = {
724 .advance = xfrm_replay_advance_bmp,
725 .check = xfrm_replay_check_bmp,
726 .recheck = xfrm_replay_check_bmp,
727 .notify = xfrm_replay_notify_bmp,
728 .overflow = xfrm_replay_overflow_bmp,
729};
730
731static const struct xfrm_replay xfrm_replay_esn = {
732 .advance = xfrm_replay_advance_esn,
733 .check = xfrm_replay_check_esn,
734 .recheck = xfrm_replay_recheck_esn,
735 .notify = xfrm_replay_notify_esn,
736 .overflow = xfrm_replay_overflow_esn,
737};
738#endif
739
740int xfrm_init_replay(struct xfrm_state *x)
741{
742 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
743
744 if (replay_esn) {
745 if (replay_esn->replay_window >
746 replay_esn->bmp_len * sizeof(__u32) * 8)
747 return -EINVAL;
748
749 if (x->props.flags & XFRM_STATE_ESN) {
750 if (replay_esn->replay_window == 0)
751 return -EINVAL;
752 x->repl = &xfrm_replay_esn;
753 } else {
754 x->repl = &xfrm_replay_bmp;
755 }
756 } else {
757 x->repl = &xfrm_replay_legacy;
758 }
759
760 return 0;
761}
762EXPORT_SYMBOL(xfrm_init_replay);