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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// 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_bmp(struct xfrm_state *x, int event);
39static void xfrm_replay_notify_esn(struct xfrm_state *x, int event);
40
41void xfrm_replay_notify(struct xfrm_state *x, int event)
42{
43 struct km_event c;
44 /* we send notify messages in case
45 * 1. we updated on of the sequence numbers, and the seqno difference
46 * is at least x->replay_maxdiff, in this case we also update the
47 * timeout of our timer function
48 * 2. if x->replay_maxage has elapsed since last update,
49 * and there were changes
50 *
51 * The state structure must be locked!
52 */
53
54 switch (x->repl_mode) {
55 case XFRM_REPLAY_MODE_LEGACY:
56 break;
57 case XFRM_REPLAY_MODE_BMP:
58 xfrm_replay_notify_bmp(x, event);
59 return;
60 case XFRM_REPLAY_MODE_ESN:
61 xfrm_replay_notify_esn(x, event);
62 return;
63 }
64
65 switch (event) {
66 case XFRM_REPLAY_UPDATE:
67 if (!x->replay_maxdiff ||
68 ((x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
69 (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff))) {
70 if (x->xflags & XFRM_TIME_DEFER)
71 event = XFRM_REPLAY_TIMEOUT;
72 else
73 return;
74 }
75
76 break;
77
78 case XFRM_REPLAY_TIMEOUT:
79 if (memcmp(&x->replay, &x->preplay,
80 sizeof(struct xfrm_replay_state)) == 0) {
81 x->xflags |= XFRM_TIME_DEFER;
82 return;
83 }
84
85 break;
86 }
87
88 memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state));
89 c.event = XFRM_MSG_NEWAE;
90 c.data.aevent = event;
91 km_state_notify(x, &c);
92
93 if (x->replay_maxage &&
94 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
95 x->xflags &= ~XFRM_TIME_DEFER;
96}
97
98static int __xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
99{
100 int err = 0;
101 struct net *net = xs_net(x);
102
103 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
104 XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
105 XFRM_SKB_CB(skb)->seq.output.hi = 0;
106 if (unlikely(x->replay.oseq == 0) &&
107 !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
108 x->replay.oseq--;
109 xfrm_audit_state_replay_overflow(x, skb);
110 err = -EOVERFLOW;
111
112 return err;
113 }
114 if (xfrm_aevent_is_on(net))
115 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
116 }
117
118 return err;
119}
120
121static int xfrm_replay_check_legacy(struct xfrm_state *x,
122 struct sk_buff *skb, __be32 net_seq)
123{
124 u32 diff;
125 u32 seq = ntohl(net_seq);
126
127 if (!x->props.replay_window)
128 return 0;
129
130 if (unlikely(seq == 0))
131 goto err;
132
133 if (likely(seq > x->replay.seq))
134 return 0;
135
136 diff = x->replay.seq - seq;
137 if (diff >= x->props.replay_window) {
138 x->stats.replay_window++;
139 goto err;
140 }
141
142 if (x->replay.bitmap & (1U << diff)) {
143 x->stats.replay++;
144 goto err;
145 }
146 return 0;
147
148err:
149 xfrm_audit_state_replay(x, skb, net_seq);
150 return -EINVAL;
151}
152
153static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq);
154static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq);
155
156void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq)
157{
158 u32 diff, seq;
159
160 switch (x->repl_mode) {
161 case XFRM_REPLAY_MODE_LEGACY:
162 break;
163 case XFRM_REPLAY_MODE_BMP:
164 return xfrm_replay_advance_bmp(x, net_seq);
165 case XFRM_REPLAY_MODE_ESN:
166 return xfrm_replay_advance_esn(x, net_seq);
167 }
168
169 if (!x->props.replay_window)
170 return;
171
172 seq = ntohl(net_seq);
173 if (seq > x->replay.seq) {
174 diff = seq - x->replay.seq;
175 if (diff < x->props.replay_window)
176 x->replay.bitmap = ((x->replay.bitmap) << diff) | 1;
177 else
178 x->replay.bitmap = 1;
179 x->replay.seq = seq;
180 } else {
181 diff = x->replay.seq - seq;
182 x->replay.bitmap |= (1U << diff);
183 }
184
185 if (xfrm_aevent_is_on(xs_net(x)))
186 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
187}
188
189static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
190{
191 int err = 0;
192 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
193 struct net *net = xs_net(x);
194
195 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
196 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
197 XFRM_SKB_CB(skb)->seq.output.hi = 0;
198 if (unlikely(replay_esn->oseq == 0) &&
199 !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
200 replay_esn->oseq--;
201 xfrm_audit_state_replay_overflow(x, skb);
202 err = -EOVERFLOW;
203
204 return err;
205 }
206 if (xfrm_aevent_is_on(net))
207 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
208 }
209
210 return err;
211}
212
213static int xfrm_replay_check_bmp(struct xfrm_state *x,
214 struct sk_buff *skb, __be32 net_seq)
215{
216 unsigned int bitnr, nr;
217 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
218 u32 pos;
219 u32 seq = ntohl(net_seq);
220 u32 diff = replay_esn->seq - seq;
221
222 if (!replay_esn->replay_window)
223 return 0;
224
225 if (unlikely(seq == 0))
226 goto err;
227
228 if (likely(seq > replay_esn->seq))
229 return 0;
230
231 if (diff >= replay_esn->replay_window) {
232 x->stats.replay_window++;
233 goto err;
234 }
235
236 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
237
238 if (pos >= diff)
239 bitnr = (pos - diff) % replay_esn->replay_window;
240 else
241 bitnr = replay_esn->replay_window - (diff - pos);
242
243 nr = bitnr >> 5;
244 bitnr = bitnr & 0x1F;
245 if (replay_esn->bmp[nr] & (1U << bitnr))
246 goto err_replay;
247
248 return 0;
249
250err_replay:
251 x->stats.replay++;
252err:
253 xfrm_audit_state_replay(x, skb, net_seq);
254 return -EINVAL;
255}
256
257static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq)
258{
259 unsigned int bitnr, nr, i;
260 u32 diff;
261 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
262 u32 seq = ntohl(net_seq);
263 u32 pos;
264
265 if (!replay_esn->replay_window)
266 return;
267
268 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
269
270 if (seq > replay_esn->seq) {
271 diff = seq - replay_esn->seq;
272
273 if (diff < replay_esn->replay_window) {
274 for (i = 1; i < diff; i++) {
275 bitnr = (pos + i) % replay_esn->replay_window;
276 nr = bitnr >> 5;
277 bitnr = bitnr & 0x1F;
278 replay_esn->bmp[nr] &= ~(1U << bitnr);
279 }
280 } else {
281 nr = (replay_esn->replay_window - 1) >> 5;
282 for (i = 0; i <= nr; i++)
283 replay_esn->bmp[i] = 0;
284 }
285
286 bitnr = (pos + diff) % replay_esn->replay_window;
287 replay_esn->seq = seq;
288 } else {
289 diff = replay_esn->seq - seq;
290
291 if (pos >= diff)
292 bitnr = (pos - diff) % replay_esn->replay_window;
293 else
294 bitnr = replay_esn->replay_window - (diff - pos);
295 }
296
297 nr = bitnr >> 5;
298 bitnr = bitnr & 0x1F;
299 replay_esn->bmp[nr] |= (1U << bitnr);
300
301 if (xfrm_aevent_is_on(xs_net(x)))
302 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
303}
304
305static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
306{
307 struct km_event c;
308 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
309 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
310
311 /* we send notify messages in case
312 * 1. we updated on of the sequence numbers, and the seqno difference
313 * is at least x->replay_maxdiff, in this case we also update the
314 * timeout of our timer function
315 * 2. if x->replay_maxage has elapsed since last update,
316 * and there were changes
317 *
318 * The state structure must be locked!
319 */
320
321 switch (event) {
322 case XFRM_REPLAY_UPDATE:
323 if (!x->replay_maxdiff ||
324 ((replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) &&
325 (replay_esn->oseq - preplay_esn->oseq
326 < x->replay_maxdiff))) {
327 if (x->xflags & XFRM_TIME_DEFER)
328 event = XFRM_REPLAY_TIMEOUT;
329 else
330 return;
331 }
332
333 break;
334
335 case XFRM_REPLAY_TIMEOUT:
336 if (memcmp(x->replay_esn, x->preplay_esn,
337 xfrm_replay_state_esn_len(replay_esn)) == 0) {
338 x->xflags |= XFRM_TIME_DEFER;
339 return;
340 }
341
342 break;
343 }
344
345 memcpy(x->preplay_esn, x->replay_esn,
346 xfrm_replay_state_esn_len(replay_esn));
347 c.event = XFRM_MSG_NEWAE;
348 c.data.aevent = event;
349 km_state_notify(x, &c);
350
351 if (x->replay_maxage &&
352 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
353 x->xflags &= ~XFRM_TIME_DEFER;
354}
355
356static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
357{
358 u32 seq_diff, oseq_diff;
359 struct km_event c;
360 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
361 struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
362
363 /* we send notify messages in case
364 * 1. we updated on of the sequence numbers, and the seqno difference
365 * is at least x->replay_maxdiff, in this case we also update the
366 * timeout of our timer function
367 * 2. if x->replay_maxage has elapsed since last update,
368 * and there were changes
369 *
370 * The state structure must be locked!
371 */
372
373 switch (event) {
374 case XFRM_REPLAY_UPDATE:
375 if (x->replay_maxdiff) {
376 if (replay_esn->seq_hi == preplay_esn->seq_hi)
377 seq_diff = replay_esn->seq - preplay_esn->seq;
378 else
379 seq_diff = ~preplay_esn->seq + replay_esn->seq
380 + 1;
381
382 if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
383 oseq_diff = replay_esn->oseq
384 - preplay_esn->oseq;
385 else
386 oseq_diff = ~preplay_esn->oseq
387 + replay_esn->oseq + 1;
388
389 if (seq_diff >= x->replay_maxdiff ||
390 oseq_diff >= x->replay_maxdiff)
391 break;
392 }
393
394 if (x->xflags & XFRM_TIME_DEFER)
395 event = XFRM_REPLAY_TIMEOUT;
396 else
397 return;
398
399 break;
400
401 case XFRM_REPLAY_TIMEOUT:
402 if (memcmp(x->replay_esn, x->preplay_esn,
403 xfrm_replay_state_esn_len(replay_esn)) == 0) {
404 x->xflags |= XFRM_TIME_DEFER;
405 return;
406 }
407
408 break;
409 }
410
411 memcpy(x->preplay_esn, x->replay_esn,
412 xfrm_replay_state_esn_len(replay_esn));
413 c.event = XFRM_MSG_NEWAE;
414 c.data.aevent = event;
415 km_state_notify(x, &c);
416
417 if (x->replay_maxage &&
418 !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
419 x->xflags &= ~XFRM_TIME_DEFER;
420}
421
422static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
423{
424 int err = 0;
425 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
426 struct net *net = xs_net(x);
427
428 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
429 XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
430 XFRM_SKB_CB(skb)->seq.output.hi = replay_esn->oseq_hi;
431
432 if (unlikely(replay_esn->oseq == 0)) {
433 XFRM_SKB_CB(skb)->seq.output.hi = ++replay_esn->oseq_hi;
434
435 if (replay_esn->oseq_hi == 0) {
436 replay_esn->oseq--;
437 replay_esn->oseq_hi--;
438 xfrm_audit_state_replay_overflow(x, skb);
439 err = -EOVERFLOW;
440
441 return err;
442 }
443 }
444 if (xfrm_aevent_is_on(net))
445 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
446 }
447
448 return err;
449}
450
451static int xfrm_replay_check_esn(struct xfrm_state *x,
452 struct sk_buff *skb, __be32 net_seq)
453{
454 unsigned int bitnr, nr;
455 u32 diff;
456 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
457 u32 pos;
458 u32 seq = ntohl(net_seq);
459 u32 wsize = replay_esn->replay_window;
460 u32 top = replay_esn->seq;
461 u32 bottom = top - wsize + 1;
462
463 if (!wsize)
464 return 0;
465
466 if (unlikely(seq == 0 && replay_esn->seq_hi == 0 &&
467 (replay_esn->seq < replay_esn->replay_window - 1)))
468 goto err;
469
470 diff = top - seq;
471
472 if (likely(top >= wsize - 1)) {
473 /* A. same subspace */
474 if (likely(seq > top) || seq < bottom)
475 return 0;
476 } else {
477 /* B. window spans two subspaces */
478 if (likely(seq > top && seq < bottom))
479 return 0;
480 if (seq >= bottom)
481 diff = ~seq + top + 1;
482 }
483
484 if (diff >= replay_esn->replay_window) {
485 x->stats.replay_window++;
486 goto err;
487 }
488
489 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
490
491 if (pos >= diff)
492 bitnr = (pos - diff) % replay_esn->replay_window;
493 else
494 bitnr = replay_esn->replay_window - (diff - pos);
495
496 nr = bitnr >> 5;
497 bitnr = bitnr & 0x1F;
498 if (replay_esn->bmp[nr] & (1U << bitnr))
499 goto err_replay;
500
501 return 0;
502
503err_replay:
504 x->stats.replay++;
505err:
506 xfrm_audit_state_replay(x, skb, net_seq);
507 return -EINVAL;
508}
509
510int xfrm_replay_check(struct xfrm_state *x,
511 struct sk_buff *skb, __be32 net_seq)
512{
513 switch (x->repl_mode) {
514 case XFRM_REPLAY_MODE_LEGACY:
515 break;
516 case XFRM_REPLAY_MODE_BMP:
517 return xfrm_replay_check_bmp(x, skb, net_seq);
518 case XFRM_REPLAY_MODE_ESN:
519 return xfrm_replay_check_esn(x, skb, net_seq);
520 }
521
522 return xfrm_replay_check_legacy(x, skb, net_seq);
523}
524
525static int xfrm_replay_recheck_esn(struct xfrm_state *x,
526 struct sk_buff *skb, __be32 net_seq)
527{
528 if (unlikely(XFRM_SKB_CB(skb)->seq.input.hi !=
529 htonl(xfrm_replay_seqhi(x, net_seq)))) {
530 x->stats.replay_window++;
531 return -EINVAL;
532 }
533
534 return xfrm_replay_check_esn(x, skb, net_seq);
535}
536
537int xfrm_replay_recheck(struct xfrm_state *x,
538 struct sk_buff *skb, __be32 net_seq)
539{
540 switch (x->repl_mode) {
541 case XFRM_REPLAY_MODE_LEGACY:
542 break;
543 case XFRM_REPLAY_MODE_BMP:
544 /* no special recheck treatment */
545 return xfrm_replay_check_bmp(x, skb, net_seq);
546 case XFRM_REPLAY_MODE_ESN:
547 return xfrm_replay_recheck_esn(x, skb, net_seq);
548 }
549
550 return xfrm_replay_check_legacy(x, skb, net_seq);
551}
552
553static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq)
554{
555 unsigned int bitnr, nr, i;
556 int wrap;
557 u32 diff, pos, seq, seq_hi;
558 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
559
560 if (!replay_esn->replay_window)
561 return;
562
563 seq = ntohl(net_seq);
564 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
565 seq_hi = xfrm_replay_seqhi(x, net_seq);
566 wrap = seq_hi - replay_esn->seq_hi;
567
568 if ((!wrap && seq > replay_esn->seq) || wrap > 0) {
569 if (likely(!wrap))
570 diff = seq - replay_esn->seq;
571 else
572 diff = ~replay_esn->seq + seq + 1;
573
574 if (diff < replay_esn->replay_window) {
575 for (i = 1; i < diff; i++) {
576 bitnr = (pos + i) % replay_esn->replay_window;
577 nr = bitnr >> 5;
578 bitnr = bitnr & 0x1F;
579 replay_esn->bmp[nr] &= ~(1U << bitnr);
580 }
581 } else {
582 nr = (replay_esn->replay_window - 1) >> 5;
583 for (i = 0; i <= nr; i++)
584 replay_esn->bmp[i] = 0;
585 }
586
587 bitnr = (pos + diff) % replay_esn->replay_window;
588 replay_esn->seq = seq;
589
590 if (unlikely(wrap > 0))
591 replay_esn->seq_hi++;
592 } else {
593 diff = replay_esn->seq - seq;
594
595 if (pos >= diff)
596 bitnr = (pos - diff) % replay_esn->replay_window;
597 else
598 bitnr = replay_esn->replay_window - (diff - pos);
599 }
600
601 xfrm_dev_state_advance_esn(x);
602
603 nr = bitnr >> 5;
604 bitnr = bitnr & 0x1F;
605 replay_esn->bmp[nr] |= (1U << bitnr);
606
607 if (xfrm_aevent_is_on(xs_net(x)))
608 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
609}
610
611#ifdef CONFIG_XFRM_OFFLOAD
612static int xfrm_replay_overflow_offload(struct xfrm_state *x, struct sk_buff *skb)
613{
614 int err = 0;
615 struct net *net = xs_net(x);
616 struct xfrm_offload *xo = xfrm_offload(skb);
617 __u32 oseq = x->replay.oseq;
618
619 if (!xo)
620 return __xfrm_replay_overflow(x, skb);
621
622 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
623 if (!skb_is_gso(skb)) {
624 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
625 xo->seq.low = oseq;
626 } else {
627 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
628 xo->seq.low = oseq + 1;
629 oseq += skb_shinfo(skb)->gso_segs;
630 }
631
632 XFRM_SKB_CB(skb)->seq.output.hi = 0;
633 xo->seq.hi = 0;
634 if (unlikely(oseq < x->replay.oseq) &&
635 !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
636 xfrm_audit_state_replay_overflow(x, skb);
637 err = -EOVERFLOW;
638
639 return err;
640 }
641
642 x->replay.oseq = oseq;
643
644 if (xfrm_aevent_is_on(net))
645 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
646 }
647
648 return err;
649}
650
651static int xfrm_replay_overflow_offload_bmp(struct xfrm_state *x, struct sk_buff *skb)
652{
653 int err = 0;
654 struct xfrm_offload *xo = xfrm_offload(skb);
655 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
656 struct net *net = xs_net(x);
657 __u32 oseq = replay_esn->oseq;
658
659 if (!xo)
660 return xfrm_replay_overflow_bmp(x, skb);
661
662 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
663 if (!skb_is_gso(skb)) {
664 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
665 xo->seq.low = oseq;
666 } else {
667 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
668 xo->seq.low = oseq + 1;
669 oseq += skb_shinfo(skb)->gso_segs;
670 }
671
672 XFRM_SKB_CB(skb)->seq.output.hi = 0;
673 xo->seq.hi = 0;
674 if (unlikely(oseq < replay_esn->oseq) &&
675 !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
676 xfrm_audit_state_replay_overflow(x, skb);
677 err = -EOVERFLOW;
678
679 return err;
680 } else {
681 replay_esn->oseq = oseq;
682 }
683
684 if (xfrm_aevent_is_on(net))
685 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
686 }
687
688 return err;
689}
690
691static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff *skb)
692{
693 int err = 0;
694 struct xfrm_offload *xo = xfrm_offload(skb);
695 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
696 struct net *net = xs_net(x);
697 __u32 oseq = replay_esn->oseq;
698 __u32 oseq_hi = replay_esn->oseq_hi;
699
700 if (!xo)
701 return xfrm_replay_overflow_esn(x, skb);
702
703 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
704 if (!skb_is_gso(skb)) {
705 XFRM_SKB_CB(skb)->seq.output.low = ++oseq;
706 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
707 xo->seq.low = oseq;
708 xo->seq.hi = oseq_hi;
709 } else {
710 XFRM_SKB_CB(skb)->seq.output.low = oseq + 1;
711 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
712 xo->seq.low = oseq + 1;
713 xo->seq.hi = oseq_hi;
714 oseq += skb_shinfo(skb)->gso_segs;
715 }
716
717 if (unlikely(oseq < replay_esn->oseq)) {
718 replay_esn->oseq_hi = ++oseq_hi;
719 if (xo->seq.low < replay_esn->oseq) {
720 XFRM_SKB_CB(skb)->seq.output.hi = oseq_hi;
721 xo->seq.hi = oseq_hi;
722 }
723 if (replay_esn->oseq_hi == 0) {
724 replay_esn->oseq--;
725 replay_esn->oseq_hi--;
726 xfrm_audit_state_replay_overflow(x, skb);
727 err = -EOVERFLOW;
728
729 return err;
730 }
731 }
732
733 replay_esn->oseq = oseq;
734
735 if (xfrm_aevent_is_on(net))
736 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
737 }
738
739 return err;
740}
741
742int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
743{
744 switch (x->repl_mode) {
745 case XFRM_REPLAY_MODE_LEGACY:
746 break;
747 case XFRM_REPLAY_MODE_BMP:
748 return xfrm_replay_overflow_offload_bmp(x, skb);
749 case XFRM_REPLAY_MODE_ESN:
750 return xfrm_replay_overflow_offload_esn(x, skb);
751 }
752
753 return xfrm_replay_overflow_offload(x, skb);
754}
755#else
756int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
757{
758 switch (x->repl_mode) {
759 case XFRM_REPLAY_MODE_LEGACY:
760 break;
761 case XFRM_REPLAY_MODE_BMP:
762 return xfrm_replay_overflow_bmp(x, skb);
763 case XFRM_REPLAY_MODE_ESN:
764 return xfrm_replay_overflow_esn(x, skb);
765 }
766
767 return __xfrm_replay_overflow(x, skb);
768}
769#endif
770
771int xfrm_init_replay(struct xfrm_state *x, struct netlink_ext_ack *extack)
772{
773 struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
774
775 if (replay_esn) {
776 if (replay_esn->replay_window >
777 replay_esn->bmp_len * sizeof(__u32) * 8) {
778 NL_SET_ERR_MSG(extack, "ESN replay window is too large for the chosen bitmap size");
779 return -EINVAL;
780 }
781
782 if (x->props.flags & XFRM_STATE_ESN) {
783 if (replay_esn->replay_window == 0 &&
784 (!x->dir || x->dir == XFRM_SA_DIR_IN)) {
785 NL_SET_ERR_MSG(extack, "ESN replay window must be > 0");
786 return -EINVAL;
787 }
788 x->repl_mode = XFRM_REPLAY_MODE_ESN;
789 } else {
790 x->repl_mode = XFRM_REPLAY_MODE_BMP;
791 }
792 } else {
793 x->repl_mode = XFRM_REPLAY_MODE_LEGACY;
794 }
795
796 return 0;
797}
798EXPORT_SYMBOL(xfrm_init_replay);