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