1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 *
5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
6 */
7
8#include <linux/kernel.h>
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/netlink.h>
12#include <linux/netfilter.h>
13#include <linux/netfilter/nf_tables.h>
14#include <net/netfilter/nf_tables_core.h>
15#include <net/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables_offload.h>
17
18struct nft_bitwise {
19 u8 sreg;
20 u8 sreg2;
21 u8 dreg;
22 enum nft_bitwise_ops op:8;
23 u8 len;
24 struct nft_data mask;
25 struct nft_data xor;
26 struct nft_data data;
27};
28
29static void nft_bitwise_eval_mask_xor(u32 *dst, const u32 *src,
30 const struct nft_bitwise *priv)
31{
32 unsigned int i;
33
34 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++)
35 dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
36}
37
38static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src,
39 const struct nft_bitwise *priv)
40{
41 u32 shift = priv->data.data[0];
42 unsigned int i;
43 u32 carry = 0;
44
45 for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) {
46 dst[i - 1] = (src[i - 1] << shift) | carry;
47 carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift);
48 }
49}
50
51static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src,
52 const struct nft_bitwise *priv)
53{
54 u32 shift = priv->data.data[0];
55 unsigned int i;
56 u32 carry = 0;
57
58 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) {
59 dst[i] = carry | (src[i] >> shift);
60 carry = src[i] << (BITS_PER_TYPE(u32) - shift);
61 }
62}
63
64static void nft_bitwise_eval_and(u32 *dst, const u32 *src, const u32 *src2,
65 const struct nft_bitwise *priv)
66{
67 unsigned int i, n;
68
69 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
70 dst[i] = src[i] & src2[i];
71}
72
73static void nft_bitwise_eval_or(u32 *dst, const u32 *src, const u32 *src2,
74 const struct nft_bitwise *priv)
75{
76 unsigned int i, n;
77
78 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
79 dst[i] = src[i] | src2[i];
80}
81
82static void nft_bitwise_eval_xor(u32 *dst, const u32 *src, const u32 *src2,
83 const struct nft_bitwise *priv)
84{
85 unsigned int i, n;
86
87 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
88 dst[i] = src[i] ^ src2[i];
89}
90
91void nft_bitwise_eval(const struct nft_expr *expr,
92 struct nft_regs *regs, const struct nft_pktinfo *pkt)
93{
94 const struct nft_bitwise *priv = nft_expr_priv(expr);
95 const u32 *src = &regs->data[priv->sreg], *src2;
96 u32 *dst = &regs->data[priv->dreg];
97
98 if (priv->op == NFT_BITWISE_MASK_XOR) {
99 nft_bitwise_eval_mask_xor(dst, src, priv);
100 return;
101 }
102 if (priv->op == NFT_BITWISE_LSHIFT) {
103 nft_bitwise_eval_lshift(dst, src, priv);
104 return;
105 }
106 if (priv->op == NFT_BITWISE_RSHIFT) {
107 nft_bitwise_eval_rshift(dst, src, priv);
108 return;
109 }
110
111 src2 = priv->sreg2 ? &regs->data[priv->sreg2] : priv->data.data;
112
113 if (priv->op == NFT_BITWISE_AND) {
114 nft_bitwise_eval_and(dst, src, src2, priv);
115 return;
116 }
117 if (priv->op == NFT_BITWISE_OR) {
118 nft_bitwise_eval_or(dst, src, src2, priv);
119 return;
120 }
121 if (priv->op == NFT_BITWISE_XOR) {
122 nft_bitwise_eval_xor(dst, src, src2, priv);
123 return;
124 }
125}
126
127static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
128 [NFTA_BITWISE_SREG] = { .type = NLA_U32 },
129 [NFTA_BITWISE_SREG2] = { .type = NLA_U32 },
130 [NFTA_BITWISE_DREG] = { .type = NLA_U32 },
131 [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
132 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
133 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
134 [NFTA_BITWISE_OP] = NLA_POLICY_MAX(NLA_BE32, 255),
135 [NFTA_BITWISE_DATA] = { .type = NLA_NESTED },
136};
137
138static int nft_bitwise_init_mask_xor(struct nft_bitwise *priv,
139 const struct nlattr *const tb[])
140{
141 struct nft_data_desc mask = {
142 .type = NFT_DATA_VALUE,
143 .size = sizeof(priv->mask),
144 .len = priv->len,
145 };
146 struct nft_data_desc xor = {
147 .type = NFT_DATA_VALUE,
148 .size = sizeof(priv->xor),
149 .len = priv->len,
150 };
151 int err;
152
153 if (tb[NFTA_BITWISE_DATA] ||
154 tb[NFTA_BITWISE_SREG2])
155 return -EINVAL;
156
157 if (!tb[NFTA_BITWISE_MASK] ||
158 !tb[NFTA_BITWISE_XOR])
159 return -EINVAL;
160
161 err = nft_data_init(NULL, data: &priv->mask, desc: &mask, nla: tb[NFTA_BITWISE_MASK]);
162 if (err < 0)
163 return err;
164
165 err = nft_data_init(NULL, data: &priv->xor, desc: &xor, nla: tb[NFTA_BITWISE_XOR]);
166 if (err < 0)
167 goto err_xor_err;
168
169 return 0;
170
171err_xor_err:
172 nft_data_release(data: &priv->mask, type: mask.type);
173
174 return err;
175}
176
177static int nft_bitwise_init_shift(struct nft_bitwise *priv,
178 const struct nlattr *const tb[])
179{
180 struct nft_data_desc desc = {
181 .type = NFT_DATA_VALUE,
182 .size = sizeof(priv->data),
183 .len = sizeof(u32),
184 };
185 int err;
186
187 if (tb[NFTA_BITWISE_MASK] ||
188 tb[NFTA_BITWISE_XOR] ||
189 tb[NFTA_BITWISE_SREG2])
190 return -EINVAL;
191
192 if (!tb[NFTA_BITWISE_DATA])
193 return -EINVAL;
194
195 err = nft_data_init(NULL, data: &priv->data, desc: &desc, nla: tb[NFTA_BITWISE_DATA]);
196 if (err < 0)
197 return err;
198
199 if (priv->data.data[0] >= BITS_PER_TYPE(u32)) {
200 nft_data_release(data: &priv->data, type: desc.type);
201 return -EINVAL;
202 }
203
204 return 0;
205}
206
207static int nft_bitwise_init_bool(const struct nft_ctx *ctx,
208 struct nft_bitwise *priv,
209 const struct nlattr *const tb[])
210{
211 int err;
212
213 if (tb[NFTA_BITWISE_MASK] ||
214 tb[NFTA_BITWISE_XOR])
215 return -EINVAL;
216
217 if ((!tb[NFTA_BITWISE_DATA] && !tb[NFTA_BITWISE_SREG2]) ||
218 (tb[NFTA_BITWISE_DATA] && tb[NFTA_BITWISE_SREG2]))
219 return -EINVAL;
220
221 if (tb[NFTA_BITWISE_DATA]) {
222 struct nft_data_desc desc = {
223 .type = NFT_DATA_VALUE,
224 .size = sizeof(priv->data),
225 .len = priv->len,
226 };
227
228 err = nft_data_init(NULL, data: &priv->data, desc: &desc,
229 nla: tb[NFTA_BITWISE_DATA]);
230 if (err < 0)
231 return err;
232 } else {
233 err = nft_parse_register_load(ctx, attr: tb[NFTA_BITWISE_SREG2],
234 sreg: &priv->sreg2, len: priv->len);
235 if (err < 0)
236 return err;
237 }
238
239 return 0;
240}
241
242static int nft_bitwise_init(const struct nft_ctx *ctx,
243 const struct nft_expr *expr,
244 const struct nlattr * const tb[])
245{
246 struct nft_bitwise *priv = nft_expr_priv(expr);
247 u32 len;
248 int err;
249
250 err = nft_parse_u32_check(attr: tb[NFTA_BITWISE_LEN], U8_MAX, dest: &len);
251 if (err < 0)
252 return err;
253
254 priv->len = len;
255
256 err = nft_parse_register_load(ctx, attr: tb[NFTA_BITWISE_SREG], sreg: &priv->sreg,
257 len: priv->len);
258 if (err < 0)
259 return err;
260
261 err = nft_parse_register_store(ctx, attr: tb[NFTA_BITWISE_DREG],
262 dreg: &priv->dreg, NULL, type: NFT_DATA_VALUE,
263 len: priv->len);
264 if (err < 0)
265 return err;
266
267 if (tb[NFTA_BITWISE_OP]) {
268 priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
269 switch (priv->op) {
270 case NFT_BITWISE_MASK_XOR:
271 case NFT_BITWISE_LSHIFT:
272 case NFT_BITWISE_RSHIFT:
273 case NFT_BITWISE_AND:
274 case NFT_BITWISE_OR:
275 case NFT_BITWISE_XOR:
276 break;
277 default:
278 return -EOPNOTSUPP;
279 }
280 } else {
281 priv->op = NFT_BITWISE_MASK_XOR;
282 }
283
284 switch(priv->op) {
285 case NFT_BITWISE_MASK_XOR:
286 err = nft_bitwise_init_mask_xor(priv, tb);
287 break;
288 case NFT_BITWISE_LSHIFT:
289 case NFT_BITWISE_RSHIFT:
290 err = nft_bitwise_init_shift(priv, tb);
291 break;
292 case NFT_BITWISE_AND:
293 case NFT_BITWISE_OR:
294 case NFT_BITWISE_XOR:
295 err = nft_bitwise_init_bool(ctx, priv, tb);
296 break;
297 }
298
299 return err;
300}
301
302static int nft_bitwise_dump_mask_xor(struct sk_buff *skb,
303 const struct nft_bitwise *priv)
304{
305 if (nft_data_dump(skb, attr: NFTA_BITWISE_MASK, data: &priv->mask,
306 type: NFT_DATA_VALUE, len: priv->len) < 0)
307 return -1;
308
309 if (nft_data_dump(skb, attr: NFTA_BITWISE_XOR, data: &priv->xor,
310 type: NFT_DATA_VALUE, len: priv->len) < 0)
311 return -1;
312
313 return 0;
314}
315
316static int nft_bitwise_dump_shift(struct sk_buff *skb,
317 const struct nft_bitwise *priv)
318{
319 if (nft_data_dump(skb, attr: NFTA_BITWISE_DATA, data: &priv->data,
320 type: NFT_DATA_VALUE, len: sizeof(u32)) < 0)
321 return -1;
322 return 0;
323}
324
325static int nft_bitwise_dump_bool(struct sk_buff *skb,
326 const struct nft_bitwise *priv)
327{
328 if (priv->sreg2) {
329 if (nft_dump_register(skb, attr: NFTA_BITWISE_SREG2, reg: priv->sreg2))
330 return -1;
331 } else {
332 if (nft_data_dump(skb, attr: NFTA_BITWISE_DATA, data: &priv->data,
333 type: NFT_DATA_VALUE, len: sizeof(u32)) < 0)
334 return -1;
335 }
336
337 return 0;
338}
339
340static int nft_bitwise_dump(struct sk_buff *skb,
341 const struct nft_expr *expr, bool reset)
342{
343 const struct nft_bitwise *priv = nft_expr_priv(expr);
344 int err = 0;
345
346 if (nft_dump_register(skb, attr: NFTA_BITWISE_SREG, reg: priv->sreg))
347 return -1;
348 if (nft_dump_register(skb, attr: NFTA_BITWISE_DREG, reg: priv->dreg))
349 return -1;
350 if (nla_put_be32(skb, attrtype: NFTA_BITWISE_LEN, htonl(priv->len)))
351 return -1;
352 if (nla_put_be32(skb, attrtype: NFTA_BITWISE_OP, htonl(priv->op)))
353 return -1;
354
355 switch (priv->op) {
356 case NFT_BITWISE_MASK_XOR:
357 err = nft_bitwise_dump_mask_xor(skb, priv);
358 break;
359 case NFT_BITWISE_LSHIFT:
360 case NFT_BITWISE_RSHIFT:
361 err = nft_bitwise_dump_shift(skb, priv);
362 break;
363 case NFT_BITWISE_AND:
364 case NFT_BITWISE_OR:
365 case NFT_BITWISE_XOR:
366 err = nft_bitwise_dump_bool(skb, priv);
367 break;
368 }
369
370 return err;
371}
372
373static struct nft_data zero;
374
375static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
376 struct nft_flow_rule *flow,
377 const struct nft_expr *expr)
378{
379 const struct nft_bitwise *priv = nft_expr_priv(expr);
380 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
381
382 if (priv->op != NFT_BITWISE_MASK_XOR)
383 return -EOPNOTSUPP;
384
385 if (memcmp(p: &priv->xor, q: &zero, size: sizeof(priv->xor)) ||
386 priv->sreg != priv->dreg || priv->len != reg->len)
387 return -EOPNOTSUPP;
388
389 memcpy(&reg->mask, &priv->mask, sizeof(priv->mask));
390
391 return 0;
392}
393
394static bool nft_bitwise_reduce(struct nft_regs_track *track,
395 const struct nft_expr *expr)
396{
397 const struct nft_bitwise *priv = nft_expr_priv(expr);
398 const struct nft_bitwise *bitwise;
399 unsigned int regcount;
400 u8 dreg;
401 int i;
402
403 if (!track->regs[priv->sreg].selector)
404 return false;
405
406 bitwise = nft_expr_priv(expr: track->regs[priv->dreg].selector);
407 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
408 track->regs[priv->sreg].num_reg == 0 &&
409 track->regs[priv->dreg].bitwise &&
410 track->regs[priv->dreg].bitwise->ops == expr->ops &&
411 priv->sreg == bitwise->sreg &&
412 priv->sreg2 == bitwise->sreg2 &&
413 priv->dreg == bitwise->dreg &&
414 priv->op == bitwise->op &&
415 priv->len == bitwise->len &&
416 !memcmp(p: &priv->mask, q: &bitwise->mask, size: sizeof(priv->mask)) &&
417 !memcmp(p: &priv->xor, q: &bitwise->xor, size: sizeof(priv->xor)) &&
418 !memcmp(p: &priv->data, q: &bitwise->data, size: sizeof(priv->data))) {
419 track->cur = expr;
420 return true;
421 }
422
423 if (track->regs[priv->sreg].bitwise ||
424 track->regs[priv->sreg].num_reg != 0) {
425 nft_reg_track_cancel(track, dreg: priv->dreg, len: priv->len);
426 return false;
427 }
428
429 if (priv->sreg != priv->dreg) {
430 nft_reg_track_update(track, expr: track->regs[priv->sreg].selector,
431 dreg: priv->dreg, len: priv->len);
432 }
433
434 dreg = priv->dreg;
435 regcount = DIV_ROUND_UP(priv->len, NFT_REG32_SIZE);
436 for (i = 0; i < regcount; i++, dreg++)
437 track->regs[dreg].bitwise = expr;
438
439 return false;
440}
441
442static const struct nft_expr_ops nft_bitwise_ops = {
443 .type = &nft_bitwise_type,
444 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
445 .eval = nft_bitwise_eval,
446 .init = nft_bitwise_init,
447 .dump = nft_bitwise_dump,
448 .reduce = nft_bitwise_reduce,
449 .offload = nft_bitwise_offload,
450};
451
452static int
453nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out)
454{
455 struct nft_data data;
456 struct nft_data_desc desc = {
457 .type = NFT_DATA_VALUE,
458 .size = sizeof(data),
459 .len = sizeof(u32),
460 };
461 int err;
462
463 err = nft_data_init(NULL, data: &data, desc: &desc, nla: tb);
464 if (err < 0)
465 return err;
466
467 *out = data.data[0];
468
469 return 0;
470}
471
472static int nft_bitwise_fast_init(const struct nft_ctx *ctx,
473 const struct nft_expr *expr,
474 const struct nlattr * const tb[])
475{
476 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
477 int err;
478
479 err = nft_parse_register_load(ctx, attr: tb[NFTA_BITWISE_SREG], sreg: &priv->sreg,
480 len: sizeof(u32));
481 if (err < 0)
482 return err;
483
484 err = nft_parse_register_store(ctx, attr: tb[NFTA_BITWISE_DREG], dreg: &priv->dreg,
485 NULL, type: NFT_DATA_VALUE, len: sizeof(u32));
486 if (err < 0)
487 return err;
488
489 if (tb[NFTA_BITWISE_DATA] ||
490 tb[NFTA_BITWISE_SREG2])
491 return -EINVAL;
492
493 if (!tb[NFTA_BITWISE_MASK] ||
494 !tb[NFTA_BITWISE_XOR])
495 return -EINVAL;
496
497 err = nft_bitwise_extract_u32_data(tb: tb[NFTA_BITWISE_MASK], out: &priv->mask);
498 if (err < 0)
499 return err;
500
501 err = nft_bitwise_extract_u32_data(tb: tb[NFTA_BITWISE_XOR], out: &priv->xor);
502 if (err < 0)
503 return err;
504
505 return 0;
506}
507
508static int
509nft_bitwise_fast_dump(struct sk_buff *skb,
510 const struct nft_expr *expr, bool reset)
511{
512 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
513 struct nft_data data;
514
515 if (nft_dump_register(skb, attr: NFTA_BITWISE_SREG, reg: priv->sreg))
516 return -1;
517 if (nft_dump_register(skb, attr: NFTA_BITWISE_DREG, reg: priv->dreg))
518 return -1;
519 if (nla_put_be32(skb, attrtype: NFTA_BITWISE_LEN, htonl(sizeof(u32))))
520 return -1;
521 if (nla_put_be32(skb, attrtype: NFTA_BITWISE_OP, htonl(NFT_BITWISE_MASK_XOR)))
522 return -1;
523
524 data.data[0] = priv->mask;
525 if (nft_data_dump(skb, attr: NFTA_BITWISE_MASK, data: &data,
526 type: NFT_DATA_VALUE, len: sizeof(u32)) < 0)
527 return -1;
528
529 data.data[0] = priv->xor;
530 if (nft_data_dump(skb, attr: NFTA_BITWISE_XOR, data: &data,
531 type: NFT_DATA_VALUE, len: sizeof(u32)) < 0)
532 return -1;
533
534 return 0;
535}
536
537static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
538 struct nft_flow_rule *flow,
539 const struct nft_expr *expr)
540{
541 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
542 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
543
544 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32))
545 return -EOPNOTSUPP;
546
547 reg->mask.data[0] = priv->mask;
548 return 0;
549}
550
551static bool nft_bitwise_fast_reduce(struct nft_regs_track *track,
552 const struct nft_expr *expr)
553{
554 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
555 const struct nft_bitwise_fast_expr *bitwise;
556
557 if (!track->regs[priv->sreg].selector)
558 return false;
559
560 bitwise = nft_expr_priv(expr: track->regs[priv->dreg].selector);
561 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
562 track->regs[priv->dreg].bitwise &&
563 track->regs[priv->dreg].bitwise->ops == expr->ops &&
564 priv->sreg == bitwise->sreg &&
565 priv->dreg == bitwise->dreg &&
566 priv->mask == bitwise->mask &&
567 priv->xor == bitwise->xor) {
568 track->cur = expr;
569 return true;
570 }
571
572 if (track->regs[priv->sreg].bitwise) {
573 nft_reg_track_cancel(track, dreg: priv->dreg, NFT_REG32_SIZE);
574 return false;
575 }
576
577 if (priv->sreg != priv->dreg) {
578 track->regs[priv->dreg].selector =
579 track->regs[priv->sreg].selector;
580 }
581 track->regs[priv->dreg].bitwise = expr;
582
583 return false;
584}
585
586const struct nft_expr_ops nft_bitwise_fast_ops = {
587 .type = &nft_bitwise_type,
588 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
589 .eval = NULL, /* inlined */
590 .init = nft_bitwise_fast_init,
591 .dump = nft_bitwise_fast_dump,
592 .reduce = nft_bitwise_fast_reduce,
593 .offload = nft_bitwise_fast_offload,
594};
595
596static const struct nft_expr_ops *
597nft_bitwise_select_ops(const struct nft_ctx *ctx,
598 const struct nlattr * const tb[])
599{
600 int err;
601 u32 len;
602
603 if (!tb[NFTA_BITWISE_LEN] ||
604 !tb[NFTA_BITWISE_SREG] ||
605 !tb[NFTA_BITWISE_DREG])
606 return ERR_PTR(error: -EINVAL);
607
608 err = nft_parse_u32_check(attr: tb[NFTA_BITWISE_LEN], U8_MAX, dest: &len);
609 if (err < 0)
610 return ERR_PTR(error: err);
611
612 if (len != sizeof(u32))
613 return &nft_bitwise_ops;
614
615 if (tb[NFTA_BITWISE_OP] &&
616 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_MASK_XOR)
617 return &nft_bitwise_ops;
618
619 return &nft_bitwise_fast_ops;
620}
621
622struct nft_expr_type nft_bitwise_type __read_mostly = {
623 .name = "bitwise",
624 .select_ops = nft_bitwise_select_ops,
625 .policy = nft_bitwise_policy,
626 .maxattr = NFTA_BITWISE_MAX,
627 .owner = THIS_MODULE,
628};
629
630bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
631 const struct nft_expr *expr)
632{
633 const struct nft_expr *last = track->last;
634 const struct nft_expr *next;
635
636 if (expr == last)
637 return false;
638
639 next = nft_expr_next(expr);
640 if (next->ops == &nft_bitwise_ops)
641 return nft_bitwise_reduce(track, expr: next);
642 else if (next->ops == &nft_bitwise_fast_ops)
643 return nft_bitwise_fast_reduce(track, expr: next);
644
645 return false;
646}
647EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise);
648

source code of linux/net/netfilter/nft_bitwise.c