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1/*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/netlink.h>
15#include <linux/netfilter.h>
16#include <linux/netfilter/nf_tables.h>
17#include <net/netfilter/nf_tables_core.h>
18#include <net/netfilter/nf_tables.h>
19
20struct nft_bitwise {
21 enum nft_registers sreg:8;
22 enum nft_registers dreg:8;
23 u8 len;
24 struct nft_data mask;
25 struct nft_data xor;
26};
27
28static void nft_bitwise_eval(const struct nft_expr *expr,
29 struct nft_regs *regs,
30 const struct nft_pktinfo *pkt)
31{
32 const struct nft_bitwise *priv = nft_expr_priv(expr);
33 const u32 *src = ®s->data[priv->sreg];
34 u32 *dst = ®s->data[priv->dreg];
35 unsigned int i;
36
37 for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++)
38 dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
39}
40
41static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
42 [NFTA_BITWISE_SREG] = { .type = NLA_U32 },
43 [NFTA_BITWISE_DREG] = { .type = NLA_U32 },
44 [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
45 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
46 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
47};
48
49static int nft_bitwise_init(const struct nft_ctx *ctx,
50 const struct nft_expr *expr,
51 const struct nlattr * const tb[])
52{
53 struct nft_bitwise *priv = nft_expr_priv(expr);
54 struct nft_data_desc d1, d2;
55 u32 len;
56 int err;
57
58 if (tb[NFTA_BITWISE_SREG] == NULL ||
59 tb[NFTA_BITWISE_DREG] == NULL ||
60 tb[NFTA_BITWISE_LEN] == NULL ||
61 tb[NFTA_BITWISE_MASK] == NULL ||
62 tb[NFTA_BITWISE_XOR] == NULL)
63 return -EINVAL;
64
65 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
66 if (err < 0)
67 return err;
68
69 priv->len = len;
70
71 priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]);
72 err = nft_validate_register_load(priv->sreg, priv->len);
73 if (err < 0)
74 return err;
75
76 priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]);
77 err = nft_validate_register_store(ctx, priv->dreg, NULL,
78 NFT_DATA_VALUE, priv->len);
79 if (err < 0)
80 return err;
81
82 err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
83 tb[NFTA_BITWISE_MASK]);
84 if (err < 0)
85 return err;
86 if (d1.len != priv->len)
87 return -EINVAL;
88
89 err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
90 tb[NFTA_BITWISE_XOR]);
91 if (err < 0)
92 return err;
93 if (d2.len != priv->len)
94 return -EINVAL;
95
96 return 0;
97}
98
99static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
100{
101 const struct nft_bitwise *priv = nft_expr_priv(expr);
102
103 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
104 goto nla_put_failure;
105 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
106 goto nla_put_failure;
107 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
108 goto nla_put_failure;
109
110 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
111 NFT_DATA_VALUE, priv->len) < 0)
112 goto nla_put_failure;
113
114 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
115 NFT_DATA_VALUE, priv->len) < 0)
116 goto nla_put_failure;
117
118 return 0;
119
120nla_put_failure:
121 return -1;
122}
123
124static const struct nft_expr_ops nft_bitwise_ops = {
125 .type = &nft_bitwise_type,
126 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
127 .eval = nft_bitwise_eval,
128 .init = nft_bitwise_init,
129 .dump = nft_bitwise_dump,
130};
131
132struct nft_expr_type nft_bitwise_type __read_mostly = {
133 .name = "bitwise",
134 .ops = &nft_bitwise_ops,
135 .policy = nft_bitwise_policy,
136 .maxattr = NFTA_BITWISE_MAX,
137 .owner = THIS_MODULE,
138};
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 dreg;
21 enum nft_bitwise_ops op:8;
22 u8 len;
23 struct nft_data mask;
24 struct nft_data xor;
25 struct nft_data data;
26};
27
28static void nft_bitwise_eval_bool(u32 *dst, const u32 *src,
29 const struct nft_bitwise *priv)
30{
31 unsigned int i;
32
33 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++)
34 dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
35}
36
37static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src,
38 const struct nft_bitwise *priv)
39{
40 u32 shift = priv->data.data[0];
41 unsigned int i;
42 u32 carry = 0;
43
44 for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) {
45 dst[i - 1] = (src[i - 1] << shift) | carry;
46 carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift);
47 }
48}
49
50static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src,
51 const struct nft_bitwise *priv)
52{
53 u32 shift = priv->data.data[0];
54 unsigned int i;
55 u32 carry = 0;
56
57 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) {
58 dst[i] = carry | (src[i] >> shift);
59 carry = src[i] << (BITS_PER_TYPE(u32) - shift);
60 }
61}
62
63void nft_bitwise_eval(const struct nft_expr *expr,
64 struct nft_regs *regs, const struct nft_pktinfo *pkt)
65{
66 const struct nft_bitwise *priv = nft_expr_priv(expr);
67 const u32 *src = ®s->data[priv->sreg];
68 u32 *dst = ®s->data[priv->dreg];
69
70 switch (priv->op) {
71 case NFT_BITWISE_BOOL:
72 nft_bitwise_eval_bool(dst, src, priv);
73 break;
74 case NFT_BITWISE_LSHIFT:
75 nft_bitwise_eval_lshift(dst, src, priv);
76 break;
77 case NFT_BITWISE_RSHIFT:
78 nft_bitwise_eval_rshift(dst, src, priv);
79 break;
80 }
81}
82
83static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
84 [NFTA_BITWISE_SREG] = { .type = NLA_U32 },
85 [NFTA_BITWISE_DREG] = { .type = NLA_U32 },
86 [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
87 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
88 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
89 [NFTA_BITWISE_OP] = NLA_POLICY_MAX(NLA_BE32, 255),
90 [NFTA_BITWISE_DATA] = { .type = NLA_NESTED },
91};
92
93static int nft_bitwise_init_bool(struct nft_bitwise *priv,
94 const struct nlattr *const tb[])
95{
96 struct nft_data_desc mask = {
97 .type = NFT_DATA_VALUE,
98 .size = sizeof(priv->mask),
99 .len = priv->len,
100 };
101 struct nft_data_desc xor = {
102 .type = NFT_DATA_VALUE,
103 .size = sizeof(priv->xor),
104 .len = priv->len,
105 };
106 int err;
107
108 if (tb[NFTA_BITWISE_DATA])
109 return -EINVAL;
110
111 if (!tb[NFTA_BITWISE_MASK] ||
112 !tb[NFTA_BITWISE_XOR])
113 return -EINVAL;
114
115 err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]);
116 if (err < 0)
117 return err;
118
119 err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]);
120 if (err < 0)
121 goto err_xor_err;
122
123 return 0;
124
125err_xor_err:
126 nft_data_release(&priv->mask, mask.type);
127
128 return err;
129}
130
131static int nft_bitwise_init_shift(struct nft_bitwise *priv,
132 const struct nlattr *const tb[])
133{
134 struct nft_data_desc desc = {
135 .type = NFT_DATA_VALUE,
136 .size = sizeof(priv->data),
137 .len = sizeof(u32),
138 };
139 int err;
140
141 if (tb[NFTA_BITWISE_MASK] ||
142 tb[NFTA_BITWISE_XOR])
143 return -EINVAL;
144
145 if (!tb[NFTA_BITWISE_DATA])
146 return -EINVAL;
147
148 err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]);
149 if (err < 0)
150 return err;
151
152 if (priv->data.data[0] >= BITS_PER_TYPE(u32)) {
153 nft_data_release(&priv->data, desc.type);
154 return -EINVAL;
155 }
156
157 return 0;
158}
159
160static int nft_bitwise_init(const struct nft_ctx *ctx,
161 const struct nft_expr *expr,
162 const struct nlattr * const tb[])
163{
164 struct nft_bitwise *priv = nft_expr_priv(expr);
165 u32 len;
166 int err;
167
168 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
169 if (err < 0)
170 return err;
171
172 priv->len = len;
173
174 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
175 priv->len);
176 if (err < 0)
177 return err;
178
179 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG],
180 &priv->dreg, NULL, NFT_DATA_VALUE,
181 priv->len);
182 if (err < 0)
183 return err;
184
185 if (tb[NFTA_BITWISE_OP]) {
186 priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
187 switch (priv->op) {
188 case NFT_BITWISE_BOOL:
189 case NFT_BITWISE_LSHIFT:
190 case NFT_BITWISE_RSHIFT:
191 break;
192 default:
193 return -EOPNOTSUPP;
194 }
195 } else {
196 priv->op = NFT_BITWISE_BOOL;
197 }
198
199 switch(priv->op) {
200 case NFT_BITWISE_BOOL:
201 err = nft_bitwise_init_bool(priv, tb);
202 break;
203 case NFT_BITWISE_LSHIFT:
204 case NFT_BITWISE_RSHIFT:
205 err = nft_bitwise_init_shift(priv, tb);
206 break;
207 }
208
209 return err;
210}
211
212static int nft_bitwise_dump_bool(struct sk_buff *skb,
213 const struct nft_bitwise *priv)
214{
215 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
216 NFT_DATA_VALUE, priv->len) < 0)
217 return -1;
218
219 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
220 NFT_DATA_VALUE, priv->len) < 0)
221 return -1;
222
223 return 0;
224}
225
226static int nft_bitwise_dump_shift(struct sk_buff *skb,
227 const struct nft_bitwise *priv)
228{
229 if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data,
230 NFT_DATA_VALUE, sizeof(u32)) < 0)
231 return -1;
232 return 0;
233}
234
235static int nft_bitwise_dump(struct sk_buff *skb,
236 const struct nft_expr *expr, bool reset)
237{
238 const struct nft_bitwise *priv = nft_expr_priv(expr);
239 int err = 0;
240
241 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
242 return -1;
243 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
244 return -1;
245 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
246 return -1;
247 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op)))
248 return -1;
249
250 switch (priv->op) {
251 case NFT_BITWISE_BOOL:
252 err = nft_bitwise_dump_bool(skb, priv);
253 break;
254 case NFT_BITWISE_LSHIFT:
255 case NFT_BITWISE_RSHIFT:
256 err = nft_bitwise_dump_shift(skb, priv);
257 break;
258 }
259
260 return err;
261}
262
263static struct nft_data zero;
264
265static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
266 struct nft_flow_rule *flow,
267 const struct nft_expr *expr)
268{
269 const struct nft_bitwise *priv = nft_expr_priv(expr);
270 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
271
272 if (priv->op != NFT_BITWISE_BOOL)
273 return -EOPNOTSUPP;
274
275 if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
276 priv->sreg != priv->dreg || priv->len != reg->len)
277 return -EOPNOTSUPP;
278
279 memcpy(®->mask, &priv->mask, sizeof(priv->mask));
280
281 return 0;
282}
283
284static bool nft_bitwise_reduce(struct nft_regs_track *track,
285 const struct nft_expr *expr)
286{
287 const struct nft_bitwise *priv = nft_expr_priv(expr);
288 const struct nft_bitwise *bitwise;
289 unsigned int regcount;
290 u8 dreg;
291 int i;
292
293 if (!track->regs[priv->sreg].selector)
294 return false;
295
296 bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
297 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
298 track->regs[priv->sreg].num_reg == 0 &&
299 track->regs[priv->dreg].bitwise &&
300 track->regs[priv->dreg].bitwise->ops == expr->ops &&
301 priv->sreg == bitwise->sreg &&
302 priv->dreg == bitwise->dreg &&
303 priv->op == bitwise->op &&
304 priv->len == bitwise->len &&
305 !memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) &&
306 !memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) &&
307 !memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) {
308 track->cur = expr;
309 return true;
310 }
311
312 if (track->regs[priv->sreg].bitwise ||
313 track->regs[priv->sreg].num_reg != 0) {
314 nft_reg_track_cancel(track, priv->dreg, priv->len);
315 return false;
316 }
317
318 if (priv->sreg != priv->dreg) {
319 nft_reg_track_update(track, track->regs[priv->sreg].selector,
320 priv->dreg, priv->len);
321 }
322
323 dreg = priv->dreg;
324 regcount = DIV_ROUND_UP(priv->len, NFT_REG32_SIZE);
325 for (i = 0; i < regcount; i++, dreg++)
326 track->regs[dreg].bitwise = expr;
327
328 return false;
329}
330
331static const struct nft_expr_ops nft_bitwise_ops = {
332 .type = &nft_bitwise_type,
333 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
334 .eval = nft_bitwise_eval,
335 .init = nft_bitwise_init,
336 .dump = nft_bitwise_dump,
337 .reduce = nft_bitwise_reduce,
338 .offload = nft_bitwise_offload,
339};
340
341static int
342nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out)
343{
344 struct nft_data data;
345 struct nft_data_desc desc = {
346 .type = NFT_DATA_VALUE,
347 .size = sizeof(data),
348 .len = sizeof(u32),
349 };
350 int err;
351
352 err = nft_data_init(NULL, &data, &desc, tb);
353 if (err < 0)
354 return err;
355
356 *out = data.data[0];
357
358 return 0;
359}
360
361static int nft_bitwise_fast_init(const struct nft_ctx *ctx,
362 const struct nft_expr *expr,
363 const struct nlattr * const tb[])
364{
365 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
366 int err;
367
368 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
369 sizeof(u32));
370 if (err < 0)
371 return err;
372
373 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg,
374 NULL, NFT_DATA_VALUE, sizeof(u32));
375 if (err < 0)
376 return err;
377
378 if (tb[NFTA_BITWISE_DATA])
379 return -EINVAL;
380
381 if (!tb[NFTA_BITWISE_MASK] ||
382 !tb[NFTA_BITWISE_XOR])
383 return -EINVAL;
384
385 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask);
386 if (err < 0)
387 return err;
388
389 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor);
390 if (err < 0)
391 return err;
392
393 return 0;
394}
395
396static int
397nft_bitwise_fast_dump(struct sk_buff *skb,
398 const struct nft_expr *expr, bool reset)
399{
400 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
401 struct nft_data data;
402
403 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
404 return -1;
405 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
406 return -1;
407 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32))))
408 return -1;
409 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL)))
410 return -1;
411
412 data.data[0] = priv->mask;
413 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data,
414 NFT_DATA_VALUE, sizeof(u32)) < 0)
415 return -1;
416
417 data.data[0] = priv->xor;
418 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data,
419 NFT_DATA_VALUE, sizeof(u32)) < 0)
420 return -1;
421
422 return 0;
423}
424
425static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
426 struct nft_flow_rule *flow,
427 const struct nft_expr *expr)
428{
429 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
430 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
431
432 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32))
433 return -EOPNOTSUPP;
434
435 reg->mask.data[0] = priv->mask;
436 return 0;
437}
438
439static bool nft_bitwise_fast_reduce(struct nft_regs_track *track,
440 const struct nft_expr *expr)
441{
442 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
443 const struct nft_bitwise_fast_expr *bitwise;
444
445 if (!track->regs[priv->sreg].selector)
446 return false;
447
448 bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
449 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
450 track->regs[priv->dreg].bitwise &&
451 track->regs[priv->dreg].bitwise->ops == expr->ops &&
452 priv->sreg == bitwise->sreg &&
453 priv->dreg == bitwise->dreg &&
454 priv->mask == bitwise->mask &&
455 priv->xor == bitwise->xor) {
456 track->cur = expr;
457 return true;
458 }
459
460 if (track->regs[priv->sreg].bitwise) {
461 nft_reg_track_cancel(track, priv->dreg, NFT_REG32_SIZE);
462 return false;
463 }
464
465 if (priv->sreg != priv->dreg) {
466 track->regs[priv->dreg].selector =
467 track->regs[priv->sreg].selector;
468 }
469 track->regs[priv->dreg].bitwise = expr;
470
471 return false;
472}
473
474const struct nft_expr_ops nft_bitwise_fast_ops = {
475 .type = &nft_bitwise_type,
476 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
477 .eval = NULL, /* inlined */
478 .init = nft_bitwise_fast_init,
479 .dump = nft_bitwise_fast_dump,
480 .reduce = nft_bitwise_fast_reduce,
481 .offload = nft_bitwise_fast_offload,
482};
483
484static const struct nft_expr_ops *
485nft_bitwise_select_ops(const struct nft_ctx *ctx,
486 const struct nlattr * const tb[])
487{
488 int err;
489 u32 len;
490
491 if (!tb[NFTA_BITWISE_LEN] ||
492 !tb[NFTA_BITWISE_SREG] ||
493 !tb[NFTA_BITWISE_DREG])
494 return ERR_PTR(-EINVAL);
495
496 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
497 if (err < 0)
498 return ERR_PTR(err);
499
500 if (len != sizeof(u32))
501 return &nft_bitwise_ops;
502
503 if (tb[NFTA_BITWISE_OP] &&
504 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL)
505 return &nft_bitwise_ops;
506
507 return &nft_bitwise_fast_ops;
508}
509
510struct nft_expr_type nft_bitwise_type __read_mostly = {
511 .name = "bitwise",
512 .select_ops = nft_bitwise_select_ops,
513 .policy = nft_bitwise_policy,
514 .maxattr = NFTA_BITWISE_MAX,
515 .owner = THIS_MODULE,
516};
517
518bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
519 const struct nft_expr *expr)
520{
521 const struct nft_expr *last = track->last;
522 const struct nft_expr *next;
523
524 if (expr == last)
525 return false;
526
527 next = nft_expr_next(expr);
528 if (next->ops == &nft_bitwise_ops)
529 return nft_bitwise_reduce(track, next);
530 else if (next->ops == &nft_bitwise_fast_ops)
531 return nft_bitwise_fast_reduce(track, next);
532
533 return false;
534}
535EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise);