Linux kernel mirror (for testing)
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linux
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/if_arp.h>
14#include <linux/netfilter/nf_tables.h>
15#include <net/netfilter/nf_tables_core.h>
16#include <net/netfilter/nf_tables_offload.h>
17#include <net/netfilter/nf_tables.h>
18
19struct nft_cmp_expr {
20 struct nft_data data;
21 u8 sreg;
22 u8 len;
23 enum nft_cmp_ops op:8;
24};
25
26void nft_cmp_eval(const struct nft_expr *expr,
27 struct nft_regs *regs,
28 const struct nft_pktinfo *pkt)
29{
30 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
31 int d;
32
33 d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
34 switch (priv->op) {
35 case NFT_CMP_EQ:
36 if (d != 0)
37 goto mismatch;
38 break;
39 case NFT_CMP_NEQ:
40 if (d == 0)
41 goto mismatch;
42 break;
43 case NFT_CMP_LT:
44 if (d == 0)
45 goto mismatch;
46 fallthrough;
47 case NFT_CMP_LTE:
48 if (d > 0)
49 goto mismatch;
50 break;
51 case NFT_CMP_GT:
52 if (d == 0)
53 goto mismatch;
54 fallthrough;
55 case NFT_CMP_GTE:
56 if (d < 0)
57 goto mismatch;
58 break;
59 }
60 return;
61
62mismatch:
63 regs->verdict.code = NFT_BREAK;
64}
65
66static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
67 [NFTA_CMP_SREG] = { .type = NLA_U32 },
68 [NFTA_CMP_OP] = { .type = NLA_U32 },
69 [NFTA_CMP_DATA] = { .type = NLA_NESTED },
70};
71
72static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
73 const struct nlattr * const tb[])
74{
75 struct nft_cmp_expr *priv = nft_expr_priv(expr);
76 struct nft_data_desc desc;
77 int err;
78
79 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
80 tb[NFTA_CMP_DATA]);
81 if (err < 0)
82 return err;
83
84 if (desc.type != NFT_DATA_VALUE) {
85 err = -EINVAL;
86 nft_data_release(&priv->data, desc.type);
87 return err;
88 }
89
90 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len);
91 if (err < 0)
92 return err;
93
94 priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
95 priv->len = desc.len;
96 return 0;
97}
98
99static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
100{
101 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
102
103 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
104 goto nla_put_failure;
105 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
106 goto nla_put_failure;
107
108 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
109 NFT_DATA_VALUE, priv->len) < 0)
110 goto nla_put_failure;
111 return 0;
112
113nla_put_failure:
114 return -1;
115}
116
117union nft_cmp_offload_data {
118 u16 val16;
119 u32 val32;
120 u64 val64;
121};
122
123static void nft_payload_n2h(union nft_cmp_offload_data *data,
124 const u8 *val, u32 len)
125{
126 switch (len) {
127 case 2:
128 data->val16 = ntohs(*((u16 *)val));
129 break;
130 case 4:
131 data->val32 = ntohl(*((u32 *)val));
132 break;
133 case 8:
134 data->val64 = be64_to_cpu(*((u64 *)val));
135 break;
136 default:
137 WARN_ON_ONCE(1);
138 break;
139 }
140}
141
142static int __nft_cmp_offload(struct nft_offload_ctx *ctx,
143 struct nft_flow_rule *flow,
144 const struct nft_cmp_expr *priv)
145{
146 struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
147 union nft_cmp_offload_data _data, _datamask;
148 u8 *mask = (u8 *)&flow->match.mask;
149 u8 *key = (u8 *)&flow->match.key;
150 u8 *data, *datamask;
151
152 if (priv->op != NFT_CMP_EQ || priv->len > reg->len)
153 return -EOPNOTSUPP;
154
155 if (reg->flags & NFT_OFFLOAD_F_NETWORK2HOST) {
156 nft_payload_n2h(&_data, (u8 *)&priv->data, reg->len);
157 nft_payload_n2h(&_datamask, (u8 *)®->mask, reg->len);
158 data = (u8 *)&_data;
159 datamask = (u8 *)&_datamask;
160 } else {
161 data = (u8 *)&priv->data;
162 datamask = (u8 *)®->mask;
163 }
164
165 memcpy(key + reg->offset, data, reg->len);
166 memcpy(mask + reg->offset, datamask, reg->len);
167
168 flow->match.dissector.used_keys |= BIT(reg->key);
169 flow->match.dissector.offset[reg->key] = reg->base_offset;
170
171 if (reg->key == FLOW_DISSECTOR_KEY_META &&
172 reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
173 nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
174 return -EOPNOTSUPP;
175
176 nft_offload_update_dependency(ctx, &priv->data, reg->len);
177
178 return 0;
179}
180
181static int nft_cmp_offload(struct nft_offload_ctx *ctx,
182 struct nft_flow_rule *flow,
183 const struct nft_expr *expr)
184{
185 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
186
187 return __nft_cmp_offload(ctx, flow, priv);
188}
189
190static const struct nft_expr_ops nft_cmp_ops = {
191 .type = &nft_cmp_type,
192 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
193 .eval = nft_cmp_eval,
194 .init = nft_cmp_init,
195 .dump = nft_cmp_dump,
196 .reduce = NFT_REDUCE_READONLY,
197 .offload = nft_cmp_offload,
198};
199
200static int nft_cmp_fast_init(const struct nft_ctx *ctx,
201 const struct nft_expr *expr,
202 const struct nlattr * const tb[])
203{
204 struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
205 struct nft_data_desc desc;
206 struct nft_data data;
207 int err;
208
209 err = nft_data_init(NULL, &data, sizeof(data), &desc,
210 tb[NFTA_CMP_DATA]);
211 if (err < 0)
212 return err;
213
214 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len);
215 if (err < 0)
216 return err;
217
218 desc.len *= BITS_PER_BYTE;
219
220 priv->mask = nft_cmp_fast_mask(desc.len);
221 priv->data = data.data[0] & priv->mask;
222 priv->len = desc.len;
223 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
224 return 0;
225}
226
227static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
228 struct nft_flow_rule *flow,
229 const struct nft_expr *expr)
230{
231 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
232 struct nft_cmp_expr cmp = {
233 .data = {
234 .data = {
235 [0] = priv->data,
236 },
237 },
238 .sreg = priv->sreg,
239 .len = priv->len / BITS_PER_BYTE,
240 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,
241 };
242
243 return __nft_cmp_offload(ctx, flow, &cmp);
244}
245
246static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
247{
248 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
249 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;
250 struct nft_data data;
251
252 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
253 goto nla_put_failure;
254 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))
255 goto nla_put_failure;
256
257 data.data[0] = priv->data;
258 if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
259 NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
260 goto nla_put_failure;
261 return 0;
262
263nla_put_failure:
264 return -1;
265}
266
267const struct nft_expr_ops nft_cmp_fast_ops = {
268 .type = &nft_cmp_type,
269 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
270 .eval = NULL, /* inlined */
271 .init = nft_cmp_fast_init,
272 .dump = nft_cmp_fast_dump,
273 .reduce = NFT_REDUCE_READONLY,
274 .offload = nft_cmp_fast_offload,
275};
276
277static u32 nft_cmp_mask(u32 bitlen)
278{
279 return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen));
280}
281
282static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen)
283{
284 int len = bitlen / BITS_PER_BYTE;
285 int i, words = len / sizeof(u32);
286
287 for (i = 0; i < words; i++) {
288 data->data[i] = 0xffffffff;
289 bitlen -= sizeof(u32) * BITS_PER_BYTE;
290 }
291
292 if (len % sizeof(u32))
293 data->data[i++] = nft_cmp_mask(bitlen);
294
295 for (; i < 4; i++)
296 data->data[i] = 0;
297}
298
299static int nft_cmp16_fast_init(const struct nft_ctx *ctx,
300 const struct nft_expr *expr,
301 const struct nlattr * const tb[])
302{
303 struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);
304 struct nft_data_desc desc;
305 int err;
306
307 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
308 tb[NFTA_CMP_DATA]);
309 if (err < 0)
310 return err;
311
312 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len);
313 if (err < 0)
314 return err;
315
316 nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE);
317 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
318 priv->len = desc.len;
319
320 return 0;
321}
322
323static int nft_cmp16_fast_offload(struct nft_offload_ctx *ctx,
324 struct nft_flow_rule *flow,
325 const struct nft_expr *expr)
326{
327 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);
328 struct nft_cmp_expr cmp = {
329 .data = priv->data,
330 .sreg = priv->sreg,
331 .len = priv->len,
332 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,
333 };
334
335 return __nft_cmp_offload(ctx, flow, &cmp);
336}
337
338static int nft_cmp16_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
339{
340 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);
341 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;
342
343 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
344 goto nla_put_failure;
345 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))
346 goto nla_put_failure;
347
348 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
349 NFT_DATA_VALUE, priv->len) < 0)
350 goto nla_put_failure;
351 return 0;
352
353nla_put_failure:
354 return -1;
355}
356
357
358const struct nft_expr_ops nft_cmp16_fast_ops = {
359 .type = &nft_cmp_type,
360 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)),
361 .eval = NULL, /* inlined */
362 .init = nft_cmp16_fast_init,
363 .dump = nft_cmp16_fast_dump,
364 .reduce = NFT_REDUCE_READONLY,
365 .offload = nft_cmp16_fast_offload,
366};
367
368static const struct nft_expr_ops *
369nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
370{
371 struct nft_data_desc desc;
372 struct nft_data data;
373 enum nft_cmp_ops op;
374 u8 sreg;
375 int err;
376
377 if (tb[NFTA_CMP_SREG] == NULL ||
378 tb[NFTA_CMP_OP] == NULL ||
379 tb[NFTA_CMP_DATA] == NULL)
380 return ERR_PTR(-EINVAL);
381
382 op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
383 switch (op) {
384 case NFT_CMP_EQ:
385 case NFT_CMP_NEQ:
386 case NFT_CMP_LT:
387 case NFT_CMP_LTE:
388 case NFT_CMP_GT:
389 case NFT_CMP_GTE:
390 break;
391 default:
392 return ERR_PTR(-EINVAL);
393 }
394
395 err = nft_data_init(NULL, &data, sizeof(data), &desc,
396 tb[NFTA_CMP_DATA]);
397 if (err < 0)
398 return ERR_PTR(err);
399
400 if (desc.type != NFT_DATA_VALUE)
401 goto err1;
402
403 sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
404
405 if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) {
406 if (desc.len <= sizeof(u32))
407 return &nft_cmp_fast_ops;
408 else if (desc.len <= sizeof(data) &&
409 ((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) ||
410 (sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0)))
411 return &nft_cmp16_fast_ops;
412 }
413 return &nft_cmp_ops;
414err1:
415 nft_data_release(&data, desc.type);
416 return ERR_PTR(-EINVAL);
417}
418
419struct nft_expr_type nft_cmp_type __read_mostly = {
420 .name = "cmp",
421 .select_ops = nft_cmp_select_ops,
422 .policy = nft_cmp_policy,
423 .maxattr = NFTA_CMP_MAX,
424 .owner = THIS_MODULE,
425};