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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <[email protected]>
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 u32 tmp_src = src[i - 1];
47
48 dst[i - 1] = (tmp_src << shift) | carry;
49 carry = tmp_src >> (BITS_PER_TYPE(u32) - shift);
50 }
51}
52
53static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src,
54 const struct nft_bitwise *priv)
55{
56 u32 shift = priv->data.data[0];
57 unsigned int i;
58 u32 carry = 0;
59
60 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) {
61 u32 tmp_src = src[i];
62
63 dst[i] = carry | (tmp_src >> shift);
64 carry = tmp_src << (BITS_PER_TYPE(u32) - shift);
65 }
66}
67
68static void nft_bitwise_eval_and(u32 *dst, const u32 *src, const u32 *src2,
69 const struct nft_bitwise *priv)
70{
71 unsigned int i, n;
72
73 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
74 dst[i] = src[i] & src2[i];
75}
76
77static void nft_bitwise_eval_or(u32 *dst, const u32 *src, const u32 *src2,
78 const struct nft_bitwise *priv)
79{
80 unsigned int i, n;
81
82 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
83 dst[i] = src[i] | src2[i];
84}
85
86static void nft_bitwise_eval_xor(u32 *dst, const u32 *src, const u32 *src2,
87 const struct nft_bitwise *priv)
88{
89 unsigned int i, n;
90
91 for (i = 0, n = DIV_ROUND_UP(priv->len, sizeof(u32)); i < n; i++)
92 dst[i] = src[i] ^ src2[i];
93}
94
95void nft_bitwise_eval(const struct nft_expr *expr,
96 struct nft_regs *regs, const struct nft_pktinfo *pkt)
97{
98 const struct nft_bitwise *priv = nft_expr_priv(expr);
99 const u32 *src = &regs->data[priv->sreg], *src2;
100 u32 *dst = &regs->data[priv->dreg];
101
102 if (priv->op == NFT_BITWISE_MASK_XOR) {
103 nft_bitwise_eval_mask_xor(dst, src, priv);
104 return;
105 }
106 if (priv->op == NFT_BITWISE_LSHIFT) {
107 nft_bitwise_eval_lshift(dst, src, priv);
108 return;
109 }
110 if (priv->op == NFT_BITWISE_RSHIFT) {
111 nft_bitwise_eval_rshift(dst, src, priv);
112 return;
113 }
114
115 src2 = priv->sreg2 ? &regs->data[priv->sreg2] : priv->data.data;
116
117 if (priv->op == NFT_BITWISE_AND) {
118 nft_bitwise_eval_and(dst, src, src2, priv);
119 return;
120 }
121 if (priv->op == NFT_BITWISE_OR) {
122 nft_bitwise_eval_or(dst, src, src2, priv);
123 return;
124 }
125 if (priv->op == NFT_BITWISE_XOR) {
126 nft_bitwise_eval_xor(dst, src, src2, priv);
127 return;
128 }
129}
130
131static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
132 [NFTA_BITWISE_SREG] = NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),
133 [NFTA_BITWISE_SREG2] = NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),
134 [NFTA_BITWISE_DREG] = NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),
135 [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
136 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
137 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
138 [NFTA_BITWISE_OP] = NLA_POLICY_MAX(NLA_BE32, 255),
139 [NFTA_BITWISE_DATA] = { .type = NLA_NESTED },
140};
141
142static int nft_bitwise_init_mask_xor(struct nft_bitwise *priv,
143 const struct nlattr *const tb[])
144{
145 struct nft_data_desc mask = {
146 .type = NFT_DATA_VALUE,
147 .size = sizeof(priv->mask),
148 .len = priv->len,
149 };
150 struct nft_data_desc xor = {
151 .type = NFT_DATA_VALUE,
152 .size = sizeof(priv->xor),
153 .len = priv->len,
154 };
155 int err;
156
157 if (tb[NFTA_BITWISE_DATA] ||
158 tb[NFTA_BITWISE_SREG2])
159 return -EINVAL;
160
161 if (!tb[NFTA_BITWISE_MASK] ||
162 !tb[NFTA_BITWISE_XOR])
163 return -EINVAL;
164
165 err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]);
166 if (err < 0)
167 return err;
168
169 err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]);
170 if (err < 0)
171 goto err_xor_err;
172
173 return 0;
174
175err_xor_err:
176 nft_data_release(&priv->mask, mask.type);
177
178 return err;
179}
180
181static int nft_bitwise_init_shift(struct nft_bitwise *priv,
182 const struct nlattr *const tb[])
183{
184 struct nft_data_desc desc = {
185 .type = NFT_DATA_VALUE,
186 .size = sizeof(priv->data),
187 .len = sizeof(u32),
188 };
189 int err;
190
191 if (tb[NFTA_BITWISE_MASK] ||
192 tb[NFTA_BITWISE_XOR] ||
193 tb[NFTA_BITWISE_SREG2])
194 return -EINVAL;
195
196 if (!tb[NFTA_BITWISE_DATA])
197 return -EINVAL;
198
199 err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]);
200 if (err < 0)
201 return err;
202
203 if (!priv->data.data[0] ||
204 priv->data.data[0] >= BITS_PER_TYPE(u32)) {
205 nft_data_release(&priv->data, desc.type);
206 return -EINVAL;
207 }
208
209 return 0;
210}
211
212static int nft_bitwise_init_bool(const struct nft_ctx *ctx,
213 struct nft_bitwise *priv,
214 const struct nlattr *const tb[])
215{
216 int err;
217
218 if (tb[NFTA_BITWISE_MASK] ||
219 tb[NFTA_BITWISE_XOR])
220 return -EINVAL;
221
222 if ((!tb[NFTA_BITWISE_DATA] && !tb[NFTA_BITWISE_SREG2]) ||
223 (tb[NFTA_BITWISE_DATA] && tb[NFTA_BITWISE_SREG2]))
224 return -EINVAL;
225
226 if (tb[NFTA_BITWISE_DATA]) {
227 struct nft_data_desc desc = {
228 .type = NFT_DATA_VALUE,
229 .size = sizeof(priv->data),
230 .len = priv->len,
231 };
232
233 err = nft_data_init(NULL, &priv->data, &desc,
234 tb[NFTA_BITWISE_DATA]);
235 if (err < 0)
236 return err;
237 } else {
238 err = nft_parse_register_load(ctx, tb[NFTA_BITWISE_SREG2],
239 &priv->sreg2, priv->len);
240 if (err < 0)
241 return err;
242
243 if (nft_reg_overlap(priv->sreg2, priv->dreg, priv->len))
244 return -EINVAL;
245 }
246
247 return 0;
248}
249
250static int nft_bitwise_init(const struct nft_ctx *ctx,
251 const struct nft_expr *expr,
252 const struct nlattr * const tb[])
253{
254 struct nft_bitwise *priv = nft_expr_priv(expr);
255 u32 len;
256 int err;
257
258 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
259 if (err < 0)
260 return err;
261
262 priv->len = len;
263
264 err = nft_parse_register_load(ctx, tb[NFTA_BITWISE_SREG], &priv->sreg,
265 priv->len);
266 if (err < 0)
267 return err;
268
269 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG],
270 &priv->dreg, NULL, NFT_DATA_VALUE,
271 priv->len);
272 if (err < 0)
273 return err;
274
275 if (nft_reg_overlap(priv->sreg, priv->dreg, priv->len))
276 return -EINVAL;
277
278 if (tb[NFTA_BITWISE_OP]) {
279 priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
280 switch (priv->op) {
281 case NFT_BITWISE_MASK_XOR:
282 case NFT_BITWISE_LSHIFT:
283 case NFT_BITWISE_RSHIFT:
284 case NFT_BITWISE_AND:
285 case NFT_BITWISE_OR:
286 case NFT_BITWISE_XOR:
287 break;
288 default:
289 return -EOPNOTSUPP;
290 }
291 } else {
292 priv->op = NFT_BITWISE_MASK_XOR;
293 }
294
295 switch(priv->op) {
296 case NFT_BITWISE_MASK_XOR:
297 err = nft_bitwise_init_mask_xor(priv, tb);
298 break;
299 case NFT_BITWISE_LSHIFT:
300 case NFT_BITWISE_RSHIFT:
301 err = nft_bitwise_init_shift(priv, tb);
302 break;
303 case NFT_BITWISE_AND:
304 case NFT_BITWISE_OR:
305 case NFT_BITWISE_XOR:
306 err = nft_bitwise_init_bool(ctx, priv, tb);
307 break;
308 }
309
310 return err;
311}
312
313static int nft_bitwise_dump_mask_xor(struct sk_buff *skb,
314 const struct nft_bitwise *priv)
315{
316 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
317 NFT_DATA_VALUE, priv->len) < 0)
318 return -1;
319
320 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
321 NFT_DATA_VALUE, priv->len) < 0)
322 return -1;
323
324 return 0;
325}
326
327static int nft_bitwise_dump_shift(struct sk_buff *skb,
328 const struct nft_bitwise *priv)
329{
330 if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data,
331 NFT_DATA_VALUE, sizeof(u32)) < 0)
332 return -1;
333 return 0;
334}
335
336static int nft_bitwise_dump_bool(struct sk_buff *skb,
337 const struct nft_bitwise *priv)
338{
339 if (priv->sreg2) {
340 if (nft_dump_register(skb, NFTA_BITWISE_SREG2, priv->sreg2))
341 return -1;
342 } else {
343 if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data,
344 NFT_DATA_VALUE, sizeof(u32)) < 0)
345 return -1;
346 }
347
348 return 0;
349}
350
351static int nft_bitwise_dump(struct sk_buff *skb,
352 const struct nft_expr *expr, bool reset)
353{
354 const struct nft_bitwise *priv = nft_expr_priv(expr);
355 int err = 0;
356
357 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
358 return -1;
359 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
360 return -1;
361 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
362 return -1;
363 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op)))
364 return -1;
365
366 switch (priv->op) {
367 case NFT_BITWISE_MASK_XOR:
368 err = nft_bitwise_dump_mask_xor(skb, priv);
369 break;
370 case NFT_BITWISE_LSHIFT:
371 case NFT_BITWISE_RSHIFT:
372 err = nft_bitwise_dump_shift(skb, priv);
373 break;
374 case NFT_BITWISE_AND:
375 case NFT_BITWISE_OR:
376 case NFT_BITWISE_XOR:
377 err = nft_bitwise_dump_bool(skb, priv);
378 break;
379 }
380
381 return err;
382}
383
384static struct nft_data zero;
385
386static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
387 struct nft_flow_rule *flow,
388 const struct nft_expr *expr)
389{
390 const struct nft_bitwise *priv = nft_expr_priv(expr);
391 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
392
393 if (priv->op != NFT_BITWISE_MASK_XOR)
394 return -EOPNOTSUPP;
395
396 if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
397 priv->sreg != priv->dreg || priv->len != reg->len)
398 return -EOPNOTSUPP;
399
400 memcpy(&reg->mask, &priv->mask, sizeof(priv->mask));
401
402 return 0;
403}
404
405static const struct nft_expr_ops nft_bitwise_ops = {
406 .type = &nft_bitwise_type,
407 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
408 .eval = nft_bitwise_eval,
409 .init = nft_bitwise_init,
410 .dump = nft_bitwise_dump,
411 .offload = nft_bitwise_offload,
412};
413
414static int
415nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out)
416{
417 struct nft_data data;
418 struct nft_data_desc desc = {
419 .type = NFT_DATA_VALUE,
420 .size = sizeof(data),
421 .len = sizeof(u32),
422 };
423 int err;
424
425 err = nft_data_init(NULL, &data, &desc, tb);
426 if (err < 0)
427 return err;
428
429 *out = data.data[0];
430
431 return 0;
432}
433
434static int nft_bitwise_fast_init(const struct nft_ctx *ctx,
435 const struct nft_expr *expr,
436 const struct nlattr * const tb[])
437{
438 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
439 int err;
440
441 err = nft_parse_register_load(ctx, tb[NFTA_BITWISE_SREG], &priv->sreg,
442 sizeof(u32));
443 if (err < 0)
444 return err;
445
446 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg,
447 NULL, NFT_DATA_VALUE, sizeof(u32));
448 if (err < 0)
449 return err;
450
451 if (tb[NFTA_BITWISE_DATA] ||
452 tb[NFTA_BITWISE_SREG2])
453 return -EINVAL;
454
455 if (!tb[NFTA_BITWISE_MASK] ||
456 !tb[NFTA_BITWISE_XOR])
457 return -EINVAL;
458
459 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask);
460 if (err < 0)
461 return err;
462
463 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor);
464 if (err < 0)
465 return err;
466
467 return 0;
468}
469
470static int
471nft_bitwise_fast_dump(struct sk_buff *skb,
472 const struct nft_expr *expr, bool reset)
473{
474 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
475 struct nft_data data;
476
477 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
478 return -1;
479 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
480 return -1;
481 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32))))
482 return -1;
483 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_MASK_XOR)))
484 return -1;
485
486 data.data[0] = priv->mask;
487 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data,
488 NFT_DATA_VALUE, sizeof(u32)) < 0)
489 return -1;
490
491 data.data[0] = priv->xor;
492 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data,
493 NFT_DATA_VALUE, sizeof(u32)) < 0)
494 return -1;
495
496 return 0;
497}
498
499static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
500 struct nft_flow_rule *flow,
501 const struct nft_expr *expr)
502{
503 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
504 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
505
506 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32))
507 return -EOPNOTSUPP;
508
509 reg->mask.data[0] = priv->mask;
510 return 0;
511}
512
513const struct nft_expr_ops nft_bitwise_fast_ops = {
514 .type = &nft_bitwise_type,
515 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
516 .eval = NULL, /* inlined */
517 .init = nft_bitwise_fast_init,
518 .dump = nft_bitwise_fast_dump,
519 .offload = nft_bitwise_fast_offload,
520};
521
522static const struct nft_expr_ops *
523nft_bitwise_select_ops(const struct nft_ctx *ctx,
524 const struct nlattr * const tb[])
525{
526 int err;
527 u32 len;
528
529 if (!tb[NFTA_BITWISE_LEN] ||
530 !tb[NFTA_BITWISE_SREG] ||
531 !tb[NFTA_BITWISE_DREG])
532 return ERR_PTR(-EINVAL);
533
534 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
535 if (err < 0)
536 return ERR_PTR(err);
537
538 if (len != sizeof(u32))
539 return &nft_bitwise_ops;
540
541 if (tb[NFTA_BITWISE_OP] &&
542 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_MASK_XOR)
543 return &nft_bitwise_ops;
544
545 return &nft_bitwise_fast_ops;
546}
547
548struct nft_expr_type nft_bitwise_type __read_mostly = {
549 .name = "bitwise",
550 .select_ops = nft_bitwise_select_ops,
551 .policy = nft_bitwise_policy,
552 .maxattr = NFTA_BITWISE_MAX,
553 .owner = THIS_MODULE,
554};