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 enum nft_registers sreg:8;
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 priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
91 err = nft_validate_register_load(priv->sreg, desc.len);
92 if (err < 0)
93 return err;
94
95 priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
96 priv->len = desc.len;
97 return 0;
98}
99
100static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
101{
102 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
103
104 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
105 goto nla_put_failure;
106 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
107 goto nla_put_failure;
108
109 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
110 NFT_DATA_VALUE, priv->len) < 0)
111 goto nla_put_failure;
112 return 0;
113
114nla_put_failure:
115 return -1;
116}
117
118static int __nft_cmp_offload(struct nft_offload_ctx *ctx,
119 struct nft_flow_rule *flow,
120 const struct nft_cmp_expr *priv)
121{
122 struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
123 u8 *mask = (u8 *)&flow->match.mask;
124 u8 *key = (u8 *)&flow->match.key;
125
126 if (priv->op != NFT_CMP_EQ || reg->len != priv->len)
127 return -EOPNOTSUPP;
128
129 memcpy(key + reg->offset, &priv->data, priv->len);
130 memcpy(mask + reg->offset, ®->mask, priv->len);
131
132 flow->match.dissector.used_keys |= BIT(reg->key);
133 flow->match.dissector.offset[reg->key] = reg->base_offset;
134
135 if (reg->key == FLOW_DISSECTOR_KEY_META &&
136 reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
137 nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
138 return -EOPNOTSUPP;
139
140 nft_offload_update_dependency(ctx, &priv->data, priv->len);
141
142 return 0;
143}
144
145static int nft_cmp_offload(struct nft_offload_ctx *ctx,
146 struct nft_flow_rule *flow,
147 const struct nft_expr *expr)
148{
149 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
150
151 return __nft_cmp_offload(ctx, flow, priv);
152}
153
154static const struct nft_expr_ops nft_cmp_ops = {
155 .type = &nft_cmp_type,
156 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
157 .eval = nft_cmp_eval,
158 .init = nft_cmp_init,
159 .dump = nft_cmp_dump,
160 .offload = nft_cmp_offload,
161};
162
163static int nft_cmp_fast_init(const struct nft_ctx *ctx,
164 const struct nft_expr *expr,
165 const struct nlattr * const tb[])
166{
167 struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
168 struct nft_data_desc desc;
169 struct nft_data data;
170 int err;
171
172 err = nft_data_init(NULL, &data, sizeof(data), &desc,
173 tb[NFTA_CMP_DATA]);
174 if (err < 0)
175 return err;
176
177 priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
178 err = nft_validate_register_load(priv->sreg, desc.len);
179 if (err < 0)
180 return err;
181
182 desc.len *= BITS_PER_BYTE;
183
184 priv->mask = nft_cmp_fast_mask(desc.len);
185 priv->data = data.data[0] & priv->mask;
186 priv->len = desc.len;
187 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
188 return 0;
189}
190
191static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
192 struct nft_flow_rule *flow,
193 const struct nft_expr *expr)
194{
195 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
196 struct nft_cmp_expr cmp = {
197 .data = {
198 .data = {
199 [0] = priv->data,
200 },
201 },
202 .sreg = priv->sreg,
203 .len = priv->len / BITS_PER_BYTE,
204 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,
205 };
206
207 return __nft_cmp_offload(ctx, flow, &cmp);
208}
209
210static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
211{
212 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
213 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;
214 struct nft_data data;
215
216 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
217 goto nla_put_failure;
218 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))
219 goto nla_put_failure;
220
221 data.data[0] = priv->data;
222 if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
223 NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
224 goto nla_put_failure;
225 return 0;
226
227nla_put_failure:
228 return -1;
229}
230
231const struct nft_expr_ops nft_cmp_fast_ops = {
232 .type = &nft_cmp_type,
233 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
234 .eval = NULL, /* inlined */
235 .init = nft_cmp_fast_init,
236 .dump = nft_cmp_fast_dump,
237 .offload = nft_cmp_fast_offload,
238};
239
240static const struct nft_expr_ops *
241nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
242{
243 struct nft_data_desc desc;
244 struct nft_data data;
245 enum nft_cmp_ops op;
246 int err;
247
248 if (tb[NFTA_CMP_SREG] == NULL ||
249 tb[NFTA_CMP_OP] == NULL ||
250 tb[NFTA_CMP_DATA] == NULL)
251 return ERR_PTR(-EINVAL);
252
253 op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
254 switch (op) {
255 case NFT_CMP_EQ:
256 case NFT_CMP_NEQ:
257 case NFT_CMP_LT:
258 case NFT_CMP_LTE:
259 case NFT_CMP_GT:
260 case NFT_CMP_GTE:
261 break;
262 default:
263 return ERR_PTR(-EINVAL);
264 }
265
266 err = nft_data_init(NULL, &data, sizeof(data), &desc,
267 tb[NFTA_CMP_DATA]);
268 if (err < 0)
269 return ERR_PTR(err);
270
271 if (desc.type != NFT_DATA_VALUE) {
272 err = -EINVAL;
273 goto err1;
274 }
275
276 if (desc.len <= sizeof(u32) && (op == NFT_CMP_EQ || op == NFT_CMP_NEQ))
277 return &nft_cmp_fast_ops;
278
279 return &nft_cmp_ops;
280err1:
281 nft_data_release(&data, desc.type);
282 return ERR_PTR(-EINVAL);
283}
284
285struct nft_expr_type nft_cmp_type __read_mostly = {
286 .name = "cmp",
287 .select_ops = nft_cmp_select_ops,
288 .policy = nft_cmp_policy,
289 .maxattr = NFTA_CMP_MAX,
290 .owner = THIS_MODULE,
291};