Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 1 | /* |
| 2 | * xfrm_replay.c - xfrm replay detection, derived from xfrm_state.c. |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 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. |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 19 | */ |
| 20 | |
| 21 | #include <net/xfrm.h> |
| 22 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 23 | u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq) |
| 24 | { |
| 25 | u32 seq, seq_hi, bottom; |
| 26 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 27 | |
| 28 | if (!(x->props.flags & XFRM_STATE_ESN)) |
| 29 | return 0; |
| 30 | |
| 31 | seq = ntohl(net_seq); |
| 32 | seq_hi = replay_esn->seq_hi; |
| 33 | bottom = replay_esn->seq - replay_esn->replay_window + 1; |
| 34 | |
| 35 | if (likely(replay_esn->seq >= replay_esn->replay_window - 1)) { |
| 36 | /* A. same subspace */ |
| 37 | if (unlikely(seq < bottom)) |
| 38 | seq_hi++; |
| 39 | } else { |
| 40 | /* B. window spans two subspaces */ |
| 41 | if (unlikely(seq >= bottom)) |
| 42 | seq_hi--; |
| 43 | } |
| 44 | |
| 45 | return seq_hi; |
| 46 | } |
| 47 | |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 48 | static void xfrm_replay_notify(struct xfrm_state *x, int event) |
| 49 | { |
| 50 | struct km_event c; |
| 51 | /* we send notify messages in case |
| 52 | * 1. we updated on of the sequence numbers, and the seqno difference |
| 53 | * is at least x->replay_maxdiff, in this case we also update the |
| 54 | * timeout of our timer function |
| 55 | * 2. if x->replay_maxage has elapsed since last update, |
| 56 | * and there were changes |
| 57 | * |
| 58 | * The state structure must be locked! |
| 59 | */ |
| 60 | |
| 61 | switch (event) { |
| 62 | case XFRM_REPLAY_UPDATE: |
| 63 | if (x->replay_maxdiff && |
| 64 | (x->replay.seq - x->preplay.seq < x->replay_maxdiff) && |
| 65 | (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff)) { |
| 66 | if (x->xflags & XFRM_TIME_DEFER) |
| 67 | event = XFRM_REPLAY_TIMEOUT; |
| 68 | else |
| 69 | return; |
| 70 | } |
| 71 | |
| 72 | break; |
| 73 | |
| 74 | case XFRM_REPLAY_TIMEOUT: |
| 75 | if (memcmp(&x->replay, &x->preplay, |
| 76 | sizeof(struct xfrm_replay_state)) == 0) { |
| 77 | x->xflags |= XFRM_TIME_DEFER; |
| 78 | return; |
| 79 | } |
| 80 | |
| 81 | break; |
| 82 | } |
| 83 | |
| 84 | memcpy(&x->preplay, &x->replay, sizeof(struct xfrm_replay_state)); |
| 85 | c.event = XFRM_MSG_NEWAE; |
| 86 | c.data.aevent = event; |
| 87 | km_state_notify(x, &c); |
| 88 | |
| 89 | if (x->replay_maxage && |
| 90 | !mod_timer(&x->rtimer, jiffies + x->replay_maxage)) |
| 91 | x->xflags &= ~XFRM_TIME_DEFER; |
| 92 | } |
| 93 | |
| 94 | static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb) |
| 95 | { |
| 96 | int err = 0; |
| 97 | struct net *net = xs_net(x); |
| 98 | |
| 99 | if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { |
| 100 | XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq; |
| 101 | if (unlikely(x->replay.oseq == 0)) { |
| 102 | x->replay.oseq--; |
| 103 | xfrm_audit_state_replay_overflow(x, skb); |
| 104 | err = -EOVERFLOW; |
| 105 | |
| 106 | return err; |
| 107 | } |
| 108 | if (xfrm_aevent_is_on(net)) |
| 109 | x->repl->notify(x, XFRM_REPLAY_UPDATE); |
| 110 | } |
| 111 | |
| 112 | return err; |
| 113 | } |
| 114 | |
| 115 | static int xfrm_replay_check(struct xfrm_state *x, |
| 116 | struct sk_buff *skb, __be32 net_seq) |
| 117 | { |
| 118 | u32 diff; |
| 119 | u32 seq = ntohl(net_seq); |
| 120 | |
Steffen Klassert | 36ae014 | 2011-03-28 19:45:52 +0000 | [diff] [blame] | 121 | if (!x->props.replay_window) |
| 122 | return 0; |
| 123 | |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 124 | if (unlikely(seq == 0)) |
| 125 | goto err; |
| 126 | |
| 127 | if (likely(seq > x->replay.seq)) |
| 128 | return 0; |
| 129 | |
| 130 | diff = x->replay.seq - seq; |
| 131 | if (diff >= min_t(unsigned int, x->props.replay_window, |
| 132 | sizeof(x->replay.bitmap) * 8)) { |
| 133 | x->stats.replay_window++; |
| 134 | goto err; |
| 135 | } |
| 136 | |
| 137 | if (x->replay.bitmap & (1U << diff)) { |
| 138 | x->stats.replay++; |
| 139 | goto err; |
| 140 | } |
| 141 | return 0; |
| 142 | |
| 143 | err: |
| 144 | xfrm_audit_state_replay(x, skb, net_seq); |
| 145 | return -EINVAL; |
| 146 | } |
| 147 | |
| 148 | static void xfrm_replay_advance(struct xfrm_state *x, __be32 net_seq) |
| 149 | { |
| 150 | u32 diff; |
| 151 | u32 seq = ntohl(net_seq); |
| 152 | |
| 153 | if (!x->props.replay_window) |
| 154 | return; |
| 155 | |
| 156 | if (seq > x->replay.seq) { |
| 157 | diff = seq - x->replay.seq; |
| 158 | if (diff < x->props.replay_window) |
| 159 | x->replay.bitmap = ((x->replay.bitmap) << diff) | 1; |
| 160 | else |
| 161 | x->replay.bitmap = 1; |
| 162 | x->replay.seq = seq; |
| 163 | } else { |
| 164 | diff = x->replay.seq - seq; |
| 165 | x->replay.bitmap |= (1U << diff); |
| 166 | } |
| 167 | |
| 168 | if (xfrm_aevent_is_on(xs_net(x))) |
| 169 | xfrm_replay_notify(x, XFRM_REPLAY_UPDATE); |
| 170 | } |
| 171 | |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 172 | static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb) |
| 173 | { |
| 174 | int err = 0; |
| 175 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 176 | struct net *net = xs_net(x); |
| 177 | |
| 178 | if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { |
| 179 | XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq; |
| 180 | if (unlikely(replay_esn->oseq == 0)) { |
| 181 | replay_esn->oseq--; |
| 182 | xfrm_audit_state_replay_overflow(x, skb); |
| 183 | err = -EOVERFLOW; |
| 184 | |
| 185 | return err; |
| 186 | } |
| 187 | if (xfrm_aevent_is_on(net)) |
| 188 | x->repl->notify(x, XFRM_REPLAY_UPDATE); |
| 189 | } |
| 190 | |
| 191 | return err; |
| 192 | } |
| 193 | |
| 194 | static int xfrm_replay_check_bmp(struct xfrm_state *x, |
| 195 | struct sk_buff *skb, __be32 net_seq) |
| 196 | { |
| 197 | unsigned int bitnr, nr; |
| 198 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
Steffen Klassert | 36ae014 | 2011-03-28 19:45:52 +0000 | [diff] [blame] | 199 | u32 pos; |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 200 | u32 seq = ntohl(net_seq); |
| 201 | u32 diff = replay_esn->seq - seq; |
Steffen Klassert | 36ae014 | 2011-03-28 19:45:52 +0000 | [diff] [blame] | 202 | |
| 203 | if (!replay_esn->replay_window) |
| 204 | return 0; |
| 205 | |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 206 | if (unlikely(seq == 0)) |
| 207 | goto err; |
| 208 | |
| 209 | if (likely(seq > replay_esn->seq)) |
| 210 | return 0; |
| 211 | |
| 212 | if (diff >= replay_esn->replay_window) { |
| 213 | x->stats.replay_window++; |
| 214 | goto err; |
| 215 | } |
| 216 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 217 | pos = (replay_esn->seq - 1) % replay_esn->replay_window; |
| 218 | |
| 219 | if (pos >= diff) |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 220 | bitnr = (pos - diff) % replay_esn->replay_window; |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 221 | else |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 222 | bitnr = replay_esn->replay_window - (diff - pos); |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 223 | |
| 224 | nr = bitnr >> 5; |
| 225 | bitnr = bitnr & 0x1F; |
| 226 | if (replay_esn->bmp[nr] & (1U << bitnr)) |
| 227 | goto err_replay; |
| 228 | |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 229 | return 0; |
| 230 | |
| 231 | err_replay: |
| 232 | x->stats.replay++; |
| 233 | err: |
| 234 | xfrm_audit_state_replay(x, skb, net_seq); |
| 235 | return -EINVAL; |
| 236 | } |
| 237 | |
| 238 | static void xfrm_replay_advance_bmp(struct xfrm_state *x, __be32 net_seq) |
| 239 | { |
| 240 | unsigned int bitnr, nr, i; |
| 241 | u32 diff; |
| 242 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 243 | u32 seq = ntohl(net_seq); |
| 244 | u32 pos = (replay_esn->seq - 1) % replay_esn->replay_window; |
| 245 | |
| 246 | if (!replay_esn->replay_window) |
| 247 | return; |
| 248 | |
| 249 | if (seq > replay_esn->seq) { |
| 250 | diff = seq - replay_esn->seq; |
| 251 | |
| 252 | if (diff < replay_esn->replay_window) { |
| 253 | for (i = 1; i < diff; i++) { |
| 254 | bitnr = (pos + i) % replay_esn->replay_window; |
| 255 | nr = bitnr >> 5; |
| 256 | bitnr = bitnr & 0x1F; |
| 257 | replay_esn->bmp[nr] &= ~(1U << bitnr); |
| 258 | } |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 259 | } else { |
Steffen Klassert | e756682 | 2011-06-05 20:46:03 +0000 | [diff] [blame] | 260 | nr = (replay_esn->replay_window - 1) >> 5; |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 261 | for (i = 0; i <= nr; i++) |
| 262 | replay_esn->bmp[i] = 0; |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 263 | } |
| 264 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 265 | bitnr = (pos + diff) % replay_esn->replay_window; |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 266 | replay_esn->seq = seq; |
| 267 | } else { |
| 268 | diff = replay_esn->seq - seq; |
| 269 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 270 | if (pos >= diff) |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 271 | bitnr = (pos - diff) % replay_esn->replay_window; |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 272 | else |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 273 | bitnr = replay_esn->replay_window - (diff - pos); |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 274 | } |
| 275 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 276 | nr = bitnr >> 5; |
| 277 | bitnr = bitnr & 0x1F; |
| 278 | replay_esn->bmp[nr] |= (1U << bitnr); |
| 279 | |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 280 | if (xfrm_aevent_is_on(xs_net(x))) |
| 281 | xfrm_replay_notify(x, XFRM_REPLAY_UPDATE); |
| 282 | } |
| 283 | |
| 284 | static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event) |
| 285 | { |
| 286 | struct km_event c; |
| 287 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 288 | struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn; |
| 289 | |
| 290 | /* we send notify messages in case |
| 291 | * 1. we updated on of the sequence numbers, and the seqno difference |
| 292 | * is at least x->replay_maxdiff, in this case we also update the |
| 293 | * timeout of our timer function |
| 294 | * 2. if x->replay_maxage has elapsed since last update, |
| 295 | * and there were changes |
| 296 | * |
| 297 | * The state structure must be locked! |
| 298 | */ |
| 299 | |
| 300 | switch (event) { |
| 301 | case XFRM_REPLAY_UPDATE: |
| 302 | if (x->replay_maxdiff && |
| 303 | (replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) && |
| 304 | (replay_esn->oseq - preplay_esn->oseq < x->replay_maxdiff)) { |
| 305 | if (x->xflags & XFRM_TIME_DEFER) |
| 306 | event = XFRM_REPLAY_TIMEOUT; |
| 307 | else |
| 308 | return; |
| 309 | } |
| 310 | |
| 311 | break; |
| 312 | |
| 313 | case XFRM_REPLAY_TIMEOUT: |
| 314 | if (memcmp(x->replay_esn, x->preplay_esn, |
| 315 | xfrm_replay_state_esn_len(replay_esn)) == 0) { |
| 316 | x->xflags |= XFRM_TIME_DEFER; |
| 317 | return; |
| 318 | } |
| 319 | |
| 320 | break; |
| 321 | } |
| 322 | |
| 323 | memcpy(x->preplay_esn, x->replay_esn, |
| 324 | xfrm_replay_state_esn_len(replay_esn)); |
| 325 | c.event = XFRM_MSG_NEWAE; |
| 326 | c.data.aevent = event; |
| 327 | km_state_notify(x, &c); |
| 328 | |
| 329 | if (x->replay_maxage && |
| 330 | !mod_timer(&x->rtimer, jiffies + x->replay_maxage)) |
| 331 | x->xflags &= ~XFRM_TIME_DEFER; |
| 332 | } |
| 333 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 334 | static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb) |
| 335 | { |
| 336 | int err = 0; |
| 337 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 338 | struct net *net = xs_net(x); |
| 339 | |
| 340 | if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { |
| 341 | XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq; |
| 342 | XFRM_SKB_CB(skb)->seq.output.hi = replay_esn->oseq_hi; |
| 343 | |
| 344 | if (unlikely(replay_esn->oseq == 0)) { |
| 345 | XFRM_SKB_CB(skb)->seq.output.hi = ++replay_esn->oseq_hi; |
| 346 | |
| 347 | if (replay_esn->oseq_hi == 0) { |
| 348 | replay_esn->oseq--; |
| 349 | replay_esn->oseq_hi--; |
| 350 | xfrm_audit_state_replay_overflow(x, skb); |
| 351 | err = -EOVERFLOW; |
| 352 | |
| 353 | return err; |
| 354 | } |
| 355 | } |
| 356 | if (xfrm_aevent_is_on(net)) |
| 357 | x->repl->notify(x, XFRM_REPLAY_UPDATE); |
| 358 | } |
| 359 | |
| 360 | return err; |
| 361 | } |
| 362 | |
| 363 | static int xfrm_replay_check_esn(struct xfrm_state *x, |
| 364 | struct sk_buff *skb, __be32 net_seq) |
| 365 | { |
| 366 | unsigned int bitnr, nr; |
| 367 | u32 diff; |
| 368 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
Steffen Klassert | 36ae014 | 2011-03-28 19:45:52 +0000 | [diff] [blame] | 369 | u32 pos; |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 370 | u32 seq = ntohl(net_seq); |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 371 | u32 wsize = replay_esn->replay_window; |
| 372 | u32 top = replay_esn->seq; |
| 373 | u32 bottom = top - wsize + 1; |
| 374 | |
Steffen Klassert | 36ae014 | 2011-03-28 19:45:52 +0000 | [diff] [blame] | 375 | if (!wsize) |
| 376 | return 0; |
| 377 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 378 | if (unlikely(seq == 0 && replay_esn->seq_hi == 0 && |
| 379 | (replay_esn->seq < replay_esn->replay_window - 1))) |
| 380 | goto err; |
| 381 | |
| 382 | diff = top - seq; |
| 383 | |
| 384 | if (likely(top >= wsize - 1)) { |
| 385 | /* A. same subspace */ |
| 386 | if (likely(seq > top) || seq < bottom) |
| 387 | return 0; |
| 388 | } else { |
| 389 | /* B. window spans two subspaces */ |
| 390 | if (likely(seq > top && seq < bottom)) |
| 391 | return 0; |
| 392 | if (seq >= bottom) |
| 393 | diff = ~seq + top + 1; |
| 394 | } |
| 395 | |
| 396 | if (diff >= replay_esn->replay_window) { |
| 397 | x->stats.replay_window++; |
| 398 | goto err; |
| 399 | } |
| 400 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 401 | pos = (replay_esn->seq - 1) % replay_esn->replay_window; |
| 402 | |
| 403 | if (pos >= diff) |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 404 | bitnr = (pos - diff) % replay_esn->replay_window; |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 405 | else |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 406 | bitnr = replay_esn->replay_window - (diff - pos); |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 407 | |
| 408 | nr = bitnr >> 5; |
| 409 | bitnr = bitnr & 0x1F; |
| 410 | if (replay_esn->bmp[nr] & (1U << bitnr)) |
| 411 | goto err_replay; |
| 412 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 413 | return 0; |
| 414 | |
| 415 | err_replay: |
| 416 | x->stats.replay++; |
| 417 | err: |
| 418 | xfrm_audit_state_replay(x, skb, net_seq); |
| 419 | return -EINVAL; |
| 420 | } |
| 421 | |
| 422 | static void xfrm_replay_advance_esn(struct xfrm_state *x, __be32 net_seq) |
| 423 | { |
| 424 | unsigned int bitnr, nr, i; |
| 425 | int wrap; |
| 426 | u32 diff, pos, seq, seq_hi; |
| 427 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 428 | |
| 429 | if (!replay_esn->replay_window) |
| 430 | return; |
| 431 | |
| 432 | seq = ntohl(net_seq); |
| 433 | pos = (replay_esn->seq - 1) % replay_esn->replay_window; |
| 434 | seq_hi = xfrm_replay_seqhi(x, net_seq); |
| 435 | wrap = seq_hi - replay_esn->seq_hi; |
| 436 | |
| 437 | if ((!wrap && seq > replay_esn->seq) || wrap > 0) { |
| 438 | if (likely(!wrap)) |
| 439 | diff = seq - replay_esn->seq; |
| 440 | else |
| 441 | diff = ~replay_esn->seq + seq + 1; |
| 442 | |
| 443 | if (diff < replay_esn->replay_window) { |
| 444 | for (i = 1; i < diff; i++) { |
| 445 | bitnr = (pos + i) % replay_esn->replay_window; |
| 446 | nr = bitnr >> 5; |
| 447 | bitnr = bitnr & 0x1F; |
| 448 | replay_esn->bmp[nr] &= ~(1U << bitnr); |
| 449 | } |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 450 | } else { |
Steffen Klassert | e756682 | 2011-06-05 20:46:03 +0000 | [diff] [blame] | 451 | nr = (replay_esn->replay_window - 1) >> 5; |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 452 | for (i = 0; i <= nr; i++) |
| 453 | replay_esn->bmp[i] = 0; |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 454 | } |
| 455 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 456 | bitnr = (pos + diff) % replay_esn->replay_window; |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 457 | replay_esn->seq = seq; |
| 458 | |
| 459 | if (unlikely(wrap > 0)) |
| 460 | replay_esn->seq_hi++; |
| 461 | } else { |
| 462 | diff = replay_esn->seq - seq; |
| 463 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 464 | if (pos >= diff) |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 465 | bitnr = (pos - diff) % replay_esn->replay_window; |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 466 | else |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 467 | bitnr = replay_esn->replay_window - (diff - pos); |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 468 | } |
| 469 | |
Steffen Klassert | 1d97437 | 2011-10-11 01:58:37 +0000 | [diff] [blame^] | 470 | nr = bitnr >> 5; |
| 471 | bitnr = bitnr & 0x1F; |
| 472 | replay_esn->bmp[nr] |= (1U << bitnr); |
| 473 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 474 | if (xfrm_aevent_is_on(xs_net(x))) |
| 475 | xfrm_replay_notify(x, XFRM_REPLAY_UPDATE); |
| 476 | } |
| 477 | |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 478 | static struct xfrm_replay xfrm_replay_legacy = { |
| 479 | .advance = xfrm_replay_advance, |
| 480 | .check = xfrm_replay_check, |
| 481 | .notify = xfrm_replay_notify, |
| 482 | .overflow = xfrm_replay_overflow, |
| 483 | }; |
| 484 | |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 485 | static struct xfrm_replay xfrm_replay_bmp = { |
| 486 | .advance = xfrm_replay_advance_bmp, |
| 487 | .check = xfrm_replay_check_bmp, |
| 488 | .notify = xfrm_replay_notify_bmp, |
| 489 | .overflow = xfrm_replay_overflow_bmp, |
| 490 | }; |
| 491 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 492 | static struct xfrm_replay xfrm_replay_esn = { |
| 493 | .advance = xfrm_replay_advance_esn, |
| 494 | .check = xfrm_replay_check_esn, |
| 495 | .notify = xfrm_replay_notify_bmp, |
| 496 | .overflow = xfrm_replay_overflow_esn, |
| 497 | }; |
| 498 | |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 499 | int xfrm_init_replay(struct xfrm_state *x) |
| 500 | { |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 501 | struct xfrm_replay_state_esn *replay_esn = x->replay_esn; |
| 502 | |
| 503 | if (replay_esn) { |
| 504 | if (replay_esn->replay_window > |
Steffen Klassert | 3f602b0 | 2011-04-25 19:39:24 +0000 | [diff] [blame] | 505 | replay_esn->bmp_len * sizeof(__u32) * 8) |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 506 | return -EINVAL; |
| 507 | |
Steffen Klassert | 6fa5ddc | 2011-05-09 19:43:05 +0000 | [diff] [blame] | 508 | if ((x->props.flags & XFRM_STATE_ESN) && replay_esn->replay_window == 0) |
| 509 | return -EINVAL; |
| 510 | |
Steffen Klassert | 2cd0846 | 2011-03-08 00:09:51 +0000 | [diff] [blame] | 511 | if ((x->props.flags & XFRM_STATE_ESN) && x->replay_esn) |
| 512 | x->repl = &xfrm_replay_esn; |
| 513 | else |
Steffen Klassert | 97e15c3 | 2011-03-08 00:09:09 +0000 | [diff] [blame] | 514 | x->repl = &xfrm_replay_bmp; |
| 515 | } else |
| 516 | x->repl = &xfrm_replay_legacy; |
| 517 | |
Steffen Klassert | 9fdc488 | 2011-03-08 00:08:32 +0000 | [diff] [blame] | 518 | return 0; |
| 519 | } |
| 520 | EXPORT_SYMBOL(xfrm_init_replay); |