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
18 struct 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
nft_bitwise_eval_bool(u32 * dst,const u32 * src,const struct nft_bitwise * priv)28 static 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
nft_bitwise_eval_lshift(u32 * dst,const u32 * src,const struct nft_bitwise * priv)37 static 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
nft_bitwise_eval_rshift(u32 * dst,const u32 * src,const struct nft_bitwise * priv)50 static 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
nft_bitwise_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)63 void 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
83 static 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
nft_bitwise_init_bool(struct nft_bitwise * priv,const struct nlattr * const tb[])93 static 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
125 err_xor_err:
126 nft_data_release(&priv->mask, mask.type);
127
128 return err;
129 }
130
nft_bitwise_init_shift(struct nft_bitwise * priv,const struct nlattr * const tb[])131 static 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
nft_bitwise_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])160 static 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
nft_bitwise_dump_bool(struct sk_buff * skb,const struct nft_bitwise * priv)212 static 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
nft_bitwise_dump_shift(struct sk_buff * skb,const struct nft_bitwise * priv)226 static 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
nft_bitwise_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)235 static 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
263 static struct nft_data zero;
264
nft_bitwise_offload(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_expr * expr)265 static 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
nft_bitwise_reduce(struct nft_regs_track * track,const struct nft_expr * expr)284 static 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
331 static 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
341 static int
nft_bitwise_extract_u32_data(const struct nlattr * const tb,u32 * out)342 nft_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
nft_bitwise_fast_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])361 static 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
396 static int
nft_bitwise_fast_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)397 nft_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
nft_bitwise_fast_offload(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_expr * expr)425 static 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
nft_bitwise_fast_reduce(struct nft_regs_track * track,const struct nft_expr * expr)439 static 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
474 const 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
484 static const struct nft_expr_ops *
nft_bitwise_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])485 nft_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
510 struct 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
nft_expr_reduce_bitwise(struct nft_regs_track * track,const struct nft_expr * expr)518 bool 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 }
535 EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise);
536