]>
Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
cb1b69b0 LGL |
2 | /* |
3 | * Copyright (c) 2016 Laura Garcia <nevola@gmail.com> | |
cb1b69b0 LGL |
4 | */ |
5 | ||
6 | #include <linux/kernel.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/netlink.h> | |
10 | #include <linux/netfilter.h> | |
11 | #include <linux/netfilter/nf_tables.h> | |
12 | #include <net/netfilter/nf_tables.h> | |
13 | #include <net/netfilter/nf_tables_core.h> | |
14 | #include <linux/jhash.h> | |
15 | ||
511040ee | 16 | struct nft_jhash { |
4f16d25c | 17 | u8 sreg; |
345023b0 | 18 | u8 dreg; |
cb1b69b0 | 19 | u8 len; |
79e09ef9 | 20 | bool autogen_seed:1; |
cb1b69b0 LGL |
21 | u32 modulus; |
22 | u32 seed; | |
70ca767e | 23 | u32 offset; |
cb1b69b0 LGL |
24 | }; |
25 | ||
511040ee LGL |
26 | static void nft_jhash_eval(const struct nft_expr *expr, |
27 | struct nft_regs *regs, | |
28 | const struct nft_pktinfo *pkt) | |
cb1b69b0 | 29 | { |
511040ee | 30 | struct nft_jhash *priv = nft_expr_priv(expr); |
cb1b69b0 | 31 | const void *data = ®s->data[priv->sreg]; |
70ca767e | 32 | u32 h; |
cb1b69b0 | 33 | |
b9ccc07e LGL |
34 | h = reciprocal_scale(jhash(data, priv->len, priv->seed), |
35 | priv->modulus); | |
36 | ||
70ca767e | 37 | regs->data[priv->dreg] = h + priv->offset; |
cb1b69b0 LGL |
38 | } |
39 | ||
3206cade | 40 | struct nft_symhash { |
345023b0 | 41 | u8 dreg; |
3206cade LGL |
42 | u32 modulus; |
43 | u32 offset; | |
44 | }; | |
45 | ||
46 | static void nft_symhash_eval(const struct nft_expr *expr, | |
47 | struct nft_regs *regs, | |
48 | const struct nft_pktinfo *pkt) | |
49 | { | |
50 | struct nft_symhash *priv = nft_expr_priv(expr); | |
51 | struct sk_buff *skb = pkt->skb; | |
52 | u32 h; | |
53 | ||
54 | h = reciprocal_scale(__skb_get_hash_symmetric(skb), priv->modulus); | |
55 | ||
56 | regs->data[priv->dreg] = h + priv->offset; | |
57 | } | |
58 | ||
a5e57336 | 59 | static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { |
cb1b69b0 LGL |
60 | [NFTA_HASH_SREG] = { .type = NLA_U32 }, |
61 | [NFTA_HASH_DREG] = { .type = NLA_U32 }, | |
a412dbf4 | 62 | [NFTA_HASH_LEN] = NLA_POLICY_MAX(NLA_BE32, 255), |
cb1b69b0 LGL |
63 | [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, |
64 | [NFTA_HASH_SEED] = { .type = NLA_U32 }, | |
5751e175 | 65 | [NFTA_HASH_OFFSET] = { .type = NLA_U32 }, |
3206cade | 66 | [NFTA_HASH_TYPE] = { .type = NLA_U32 }, |
cb1b69b0 LGL |
67 | }; |
68 | ||
511040ee LGL |
69 | static int nft_jhash_init(const struct nft_ctx *ctx, |
70 | const struct nft_expr *expr, | |
71 | const struct nlattr * const tb[]) | |
cb1b69b0 | 72 | { |
511040ee | 73 | struct nft_jhash *priv = nft_expr_priv(expr); |
cb1b69b0 | 74 | u32 len; |
abd66e9f | 75 | int err; |
cb1b69b0 LGL |
76 | |
77 | if (!tb[NFTA_HASH_SREG] || | |
78 | !tb[NFTA_HASH_DREG] || | |
79 | !tb[NFTA_HASH_LEN] || | |
cb1b69b0 LGL |
80 | !tb[NFTA_HASH_MODULUS]) |
81 | return -EINVAL; | |
82 | ||
70ca767e LGL |
83 | if (tb[NFTA_HASH_OFFSET]) |
84 | priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET])); | |
85 | ||
abd66e9f LGL |
86 | err = nft_parse_u32_check(tb[NFTA_HASH_LEN], U8_MAX, &len); |
87 | if (err < 0) | |
88 | return err; | |
89 | if (len == 0) | |
cb1b69b0 LGL |
90 | return -ERANGE; |
91 | ||
92 | priv->len = len; | |
93 | ||
4f16d25c PNA |
94 | err = nft_parse_register_load(tb[NFTA_HASH_SREG], &priv->sreg, len); |
95 | if (err < 0) | |
96 | return err; | |
97 | ||
cb1b69b0 | 98 | priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); |
75e72f05 | 99 | if (priv->modulus < 1) |
cb1b69b0 LGL |
100 | return -ERANGE; |
101 | ||
14e2dee0 | 102 | if (priv->offset + priv->modulus - 1 < priv->offset) |
70ca767e LGL |
103 | return -EOVERFLOW; |
104 | ||
79e09ef9 | 105 | if (tb[NFTA_HASH_SEED]) { |
f86dab3a | 106 | priv->seed = ntohl(nla_get_be32(tb[NFTA_HASH_SEED])); |
79e09ef9 LZ |
107 | } else { |
108 | priv->autogen_seed = true; | |
f86dab3a | 109 | get_random_bytes(&priv->seed, sizeof(priv->seed)); |
79e09ef9 | 110 | } |
cb1b69b0 | 111 | |
345023b0 PNA |
112 | return nft_parse_register_store(ctx, tb[NFTA_HASH_DREG], &priv->dreg, |
113 | NULL, NFT_DATA_VALUE, sizeof(u32)); | |
cb1b69b0 LGL |
114 | } |
115 | ||
3206cade LGL |
116 | static int nft_symhash_init(const struct nft_ctx *ctx, |
117 | const struct nft_expr *expr, | |
118 | const struct nlattr * const tb[]) | |
119 | { | |
120 | struct nft_symhash *priv = nft_expr_priv(expr); | |
121 | ||
122 | if (!tb[NFTA_HASH_DREG] || | |
123 | !tb[NFTA_HASH_MODULUS]) | |
124 | return -EINVAL; | |
125 | ||
126 | if (tb[NFTA_HASH_OFFSET]) | |
127 | priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET])); | |
128 | ||
3206cade | 129 | priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); |
28b1d6ef | 130 | if (priv->modulus < 1) |
3206cade LGL |
131 | return -ERANGE; |
132 | ||
133 | if (priv->offset + priv->modulus - 1 < priv->offset) | |
134 | return -EOVERFLOW; | |
135 | ||
345023b0 PNA |
136 | return nft_parse_register_store(ctx, tb[NFTA_HASH_DREG], |
137 | &priv->dreg, NULL, NFT_DATA_VALUE, | |
138 | sizeof(u32)); | |
3206cade LGL |
139 | } |
140 | ||
511040ee | 141 | static int nft_jhash_dump(struct sk_buff *skb, |
7d34aa3e | 142 | const struct nft_expr *expr, bool reset) |
cb1b69b0 | 143 | { |
511040ee | 144 | const struct nft_jhash *priv = nft_expr_priv(expr); |
cb1b69b0 LGL |
145 | |
146 | if (nft_dump_register(skb, NFTA_HASH_SREG, priv->sreg)) | |
147 | goto nla_put_failure; | |
148 | if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg)) | |
149 | goto nla_put_failure; | |
7073b16f | 150 | if (nla_put_be32(skb, NFTA_HASH_LEN, htonl(priv->len))) |
cb1b69b0 | 151 | goto nla_put_failure; |
7073b16f | 152 | if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus))) |
cb1b69b0 | 153 | goto nla_put_failure; |
79e09ef9 LZ |
154 | if (!priv->autogen_seed && |
155 | nla_put_be32(skb, NFTA_HASH_SEED, htonl(priv->seed))) | |
cb1b69b0 | 156 | goto nla_put_failure; |
70ca767e LGL |
157 | if (priv->offset != 0) |
158 | if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset))) | |
159 | goto nla_put_failure; | |
3206cade LGL |
160 | if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_JENKINS))) |
161 | goto nla_put_failure; | |
162 | return 0; | |
163 | ||
164 | nla_put_failure: | |
165 | return -1; | |
166 | } | |
167 | ||
5da03b56 PNA |
168 | static bool nft_jhash_reduce(struct nft_regs_track *track, |
169 | const struct nft_expr *expr) | |
170 | { | |
171 | const struct nft_jhash *priv = nft_expr_priv(expr); | |
172 | ||
173 | nft_reg_track_cancel(track, priv->dreg, sizeof(u32)); | |
174 | ||
175 | return false; | |
176 | } | |
177 | ||
3206cade | 178 | static int nft_symhash_dump(struct sk_buff *skb, |
7d34aa3e | 179 | const struct nft_expr *expr, bool reset) |
3206cade LGL |
180 | { |
181 | const struct nft_symhash *priv = nft_expr_priv(expr); | |
182 | ||
183 | if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg)) | |
184 | goto nla_put_failure; | |
185 | if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus))) | |
186 | goto nla_put_failure; | |
187 | if (priv->offset != 0) | |
188 | if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset))) | |
189 | goto nla_put_failure; | |
190 | if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_SYM))) | |
191 | goto nla_put_failure; | |
cb1b69b0 LGL |
192 | return 0; |
193 | ||
194 | nla_put_failure: | |
195 | return -1; | |
196 | } | |
197 | ||
5da03b56 PNA |
198 | static bool nft_symhash_reduce(struct nft_regs_track *track, |
199 | const struct nft_expr *expr) | |
200 | { | |
201 | struct nft_symhash *priv = nft_expr_priv(expr); | |
202 | struct nft_symhash *symhash; | |
203 | ||
204 | if (!nft_reg_track_cmp(track, expr, priv->dreg)) { | |
205 | nft_reg_track_update(track, expr, priv->dreg, sizeof(u32)); | |
206 | return false; | |
207 | } | |
208 | ||
209 | symhash = nft_expr_priv(track->regs[priv->dreg].selector); | |
210 | if (priv->offset != symhash->offset || | |
211 | priv->modulus != symhash->modulus) { | |
212 | nft_reg_track_update(track, expr, priv->dreg, sizeof(u32)); | |
213 | return false; | |
214 | } | |
215 | ||
216 | if (!track->regs[priv->dreg].bitwise) | |
217 | return true; | |
218 | ||
219 | return false; | |
220 | } | |
221 | ||
cb1b69b0 | 222 | static struct nft_expr_type nft_hash_type; |
511040ee | 223 | static const struct nft_expr_ops nft_jhash_ops = { |
cb1b69b0 | 224 | .type = &nft_hash_type, |
511040ee LGL |
225 | .size = NFT_EXPR_SIZE(sizeof(struct nft_jhash)), |
226 | .eval = nft_jhash_eval, | |
227 | .init = nft_jhash_init, | |
228 | .dump = nft_jhash_dump, | |
5da03b56 | 229 | .reduce = nft_jhash_reduce, |
cb1b69b0 LGL |
230 | }; |
231 | ||
3206cade LGL |
232 | static const struct nft_expr_ops nft_symhash_ops = { |
233 | .type = &nft_hash_type, | |
234 | .size = NFT_EXPR_SIZE(sizeof(struct nft_symhash)), | |
235 | .eval = nft_symhash_eval, | |
236 | .init = nft_symhash_init, | |
237 | .dump = nft_symhash_dump, | |
5da03b56 | 238 | .reduce = nft_symhash_reduce, |
3206cade LGL |
239 | }; |
240 | ||
241 | static const struct nft_expr_ops * | |
242 | nft_hash_select_ops(const struct nft_ctx *ctx, | |
243 | const struct nlattr * const tb[]) | |
244 | { | |
245 | u32 type; | |
246 | ||
247 | if (!tb[NFTA_HASH_TYPE]) | |
248 | return &nft_jhash_ops; | |
249 | ||
250 | type = ntohl(nla_get_be32(tb[NFTA_HASH_TYPE])); | |
251 | switch (type) { | |
252 | case NFT_HASH_SYM: | |
253 | return &nft_symhash_ops; | |
254 | case NFT_HASH_JENKINS: | |
255 | return &nft_jhash_ops; | |
256 | default: | |
257 | break; | |
258 | } | |
259 | return ERR_PTR(-EOPNOTSUPP); | |
260 | } | |
261 | ||
cb1b69b0 LGL |
262 | static struct nft_expr_type nft_hash_type __read_mostly = { |
263 | .name = "hash", | |
d4ef3835 | 264 | .select_ops = nft_hash_select_ops, |
cb1b69b0 LGL |
265 | .policy = nft_hash_policy, |
266 | .maxattr = NFTA_HASH_MAX, | |
267 | .owner = THIS_MODULE, | |
268 | }; | |
269 | ||
270 | static int __init nft_hash_module_init(void) | |
271 | { | |
272 | return nft_register_expr(&nft_hash_type); | |
273 | } | |
274 | ||
275 | static void __exit nft_hash_module_exit(void) | |
276 | { | |
277 | nft_unregister_expr(&nft_hash_type); | |
278 | } | |
279 | ||
280 | module_init(nft_hash_module_init); | |
281 | module_exit(nft_hash_module_exit); | |
282 | ||
283 | MODULE_LICENSE("GPL"); | |
284 | MODULE_AUTHOR("Laura Garcia <nevola@gmail.com>"); | |
285 | MODULE_ALIAS_NFT_EXPR("hash"); | |
4cacc395 | 286 | MODULE_DESCRIPTION("Netfilter nftables hash module"); |