1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 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/list.h> |
11 | #include <linux/rbtree.h> |
12 | #include <linux/netlink.h> |
13 | #include <linux/netfilter.h> |
14 | #include <linux/netfilter/nf_tables.h> |
15 | #include <net/netfilter/nf_tables.h> |
16 | #include <net/netfilter/nf_tables_core.h> |
17 | |
18 | struct nft_lookup { |
19 | struct nft_set *set; |
20 | u8 sreg; |
21 | u8 dreg; |
22 | bool dreg_set; |
23 | bool invert; |
24 | struct nft_set_binding binding; |
25 | }; |
26 | |
27 | #ifdef CONFIG_RETPOLINE |
28 | bool nft_set_do_lookup(const struct net *net, const struct nft_set *set, |
29 | const u32 *key, const struct nft_set_ext **ext) |
30 | { |
31 | if (set->ops == &nft_set_hash_fast_type.ops) |
32 | return nft_hash_lookup_fast(net, set, key, ext); |
33 | if (set->ops == &nft_set_hash_type.ops) |
34 | return nft_hash_lookup(net, set, key, ext); |
35 | |
36 | if (set->ops == &nft_set_rhash_type.ops) |
37 | return nft_rhash_lookup(net, set, key, ext); |
38 | |
39 | if (set->ops == &nft_set_bitmap_type.ops) |
40 | return nft_bitmap_lookup(net, set, key, ext); |
41 | |
42 | if (set->ops == &nft_set_pipapo_type.ops) |
43 | return nft_pipapo_lookup(net, set, key, ext); |
44 | #if defined(CONFIG_X86_64) && !defined(CONFIG_UML) |
45 | if (set->ops == &nft_set_pipapo_avx2_type.ops) |
46 | return nft_pipapo_avx2_lookup(net, set, key, ext); |
47 | #endif |
48 | |
49 | if (set->ops == &nft_set_rbtree_type.ops) |
50 | return nft_rbtree_lookup(net, set, key, ext); |
51 | |
52 | WARN_ON_ONCE(1); |
53 | return set->ops->lookup(net, set, key, ext); |
54 | } |
55 | EXPORT_SYMBOL_GPL(nft_set_do_lookup); |
56 | #endif |
57 | |
58 | void nft_lookup_eval(const struct nft_expr *expr, |
59 | struct nft_regs *regs, |
60 | const struct nft_pktinfo *pkt) |
61 | { |
62 | const struct nft_lookup *priv = nft_expr_priv(expr); |
63 | const struct nft_set *set = priv->set; |
64 | const struct nft_set_ext *ext = NULL; |
65 | const struct net *net = nft_net(pkt); |
66 | bool found; |
67 | |
68 | found = nft_set_do_lookup(net, set, ®s->data[priv->sreg], &ext) ^ |
69 | priv->invert; |
70 | if (!found) { |
71 | ext = nft_set_catchall_lookup(net, set); |
72 | if (!ext) { |
73 | regs->verdict.code = NFT_BREAK; |
74 | return; |
75 | } |
76 | } |
77 | |
78 | if (ext) { |
79 | if (priv->dreg_set) |
80 | nft_data_copy(dst: ®s->data[priv->dreg], |
81 | src: nft_set_ext_data(ext), len: set->dlen); |
82 | |
83 | nft_set_elem_update_expr(ext, regs, pkt); |
84 | } |
85 | } |
86 | |
87 | static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = { |
88 | [NFTA_LOOKUP_SET] = { .type = NLA_STRING, |
89 | .len = NFT_SET_MAXNAMELEN - 1 }, |
90 | [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 }, |
91 | [NFTA_LOOKUP_SREG] = { .type = NLA_U32 }, |
92 | [NFTA_LOOKUP_DREG] = { .type = NLA_U32 }, |
93 | [NFTA_LOOKUP_FLAGS] = |
94 | NLA_POLICY_MASK(NLA_BE32, NFT_LOOKUP_F_INV), |
95 | }; |
96 | |
97 | static int nft_lookup_init(const struct nft_ctx *ctx, |
98 | const struct nft_expr *expr, |
99 | const struct nlattr * const tb[]) |
100 | { |
101 | struct nft_lookup *priv = nft_expr_priv(expr); |
102 | u8 genmask = nft_genmask_next(net: ctx->net); |
103 | struct nft_set *set; |
104 | u32 flags; |
105 | int err; |
106 | |
107 | if (tb[NFTA_LOOKUP_SET] == NULL || |
108 | tb[NFTA_LOOKUP_SREG] == NULL) |
109 | return -EINVAL; |
110 | |
111 | set = nft_set_lookup_global(net: ctx->net, table: ctx->table, nla_set_name: tb[NFTA_LOOKUP_SET], |
112 | nla_set_id: tb[NFTA_LOOKUP_SET_ID], genmask); |
113 | if (IS_ERR(ptr: set)) |
114 | return PTR_ERR(ptr: set); |
115 | |
116 | err = nft_parse_register_load(attr: tb[NFTA_LOOKUP_SREG], sreg: &priv->sreg, |
117 | len: set->klen); |
118 | if (err < 0) |
119 | return err; |
120 | |
121 | if (tb[NFTA_LOOKUP_FLAGS]) { |
122 | flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS])); |
123 | |
124 | if (flags & NFT_LOOKUP_F_INV) |
125 | priv->invert = true; |
126 | } |
127 | |
128 | if (tb[NFTA_LOOKUP_DREG] != NULL) { |
129 | if (priv->invert) |
130 | return -EINVAL; |
131 | if (!(set->flags & NFT_SET_MAP)) |
132 | return -EINVAL; |
133 | |
134 | err = nft_parse_register_store(ctx, attr: tb[NFTA_LOOKUP_DREG], |
135 | dreg: &priv->dreg, NULL, type: set->dtype, |
136 | len: set->dlen); |
137 | if (err < 0) |
138 | return err; |
139 | priv->dreg_set = true; |
140 | } else if (set->flags & NFT_SET_MAP) { |
141 | /* Map given, but user asks for lookup only (i.e. to |
142 | * ignore value assoicated with key). |
143 | * |
144 | * This makes no sense for anonymous maps since they are |
145 | * scoped to the rule, but for named sets this can be useful. |
146 | */ |
147 | if (set->flags & NFT_SET_ANONYMOUS) |
148 | return -EINVAL; |
149 | } |
150 | |
151 | priv->binding.flags = set->flags & NFT_SET_MAP; |
152 | |
153 | err = nf_tables_bind_set(ctx, set, binding: &priv->binding); |
154 | if (err < 0) |
155 | return err; |
156 | |
157 | priv->set = set; |
158 | return 0; |
159 | } |
160 | |
161 | static void nft_lookup_deactivate(const struct nft_ctx *ctx, |
162 | const struct nft_expr *expr, |
163 | enum nft_trans_phase phase) |
164 | { |
165 | struct nft_lookup *priv = nft_expr_priv(expr); |
166 | |
167 | nf_tables_deactivate_set(ctx, set: priv->set, binding: &priv->binding, phase); |
168 | } |
169 | |
170 | static void nft_lookup_activate(const struct nft_ctx *ctx, |
171 | const struct nft_expr *expr) |
172 | { |
173 | struct nft_lookup *priv = nft_expr_priv(expr); |
174 | |
175 | nf_tables_activate_set(ctx, set: priv->set); |
176 | } |
177 | |
178 | static void nft_lookup_destroy(const struct nft_ctx *ctx, |
179 | const struct nft_expr *expr) |
180 | { |
181 | struct nft_lookup *priv = nft_expr_priv(expr); |
182 | |
183 | nf_tables_destroy_set(ctx, set: priv->set); |
184 | } |
185 | |
186 | static int nft_lookup_dump(struct sk_buff *skb, |
187 | const struct nft_expr *expr, bool reset) |
188 | { |
189 | const struct nft_lookup *priv = nft_expr_priv(expr); |
190 | u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0; |
191 | |
192 | if (nla_put_string(skb, attrtype: NFTA_LOOKUP_SET, str: priv->set->name)) |
193 | goto nla_put_failure; |
194 | if (nft_dump_register(skb, attr: NFTA_LOOKUP_SREG, reg: priv->sreg)) |
195 | goto nla_put_failure; |
196 | if (priv->dreg_set) |
197 | if (nft_dump_register(skb, attr: NFTA_LOOKUP_DREG, reg: priv->dreg)) |
198 | goto nla_put_failure; |
199 | if (nla_put_be32(skb, attrtype: NFTA_LOOKUP_FLAGS, htonl(flags))) |
200 | goto nla_put_failure; |
201 | return 0; |
202 | |
203 | nla_put_failure: |
204 | return -1; |
205 | } |
206 | |
207 | static int nft_lookup_validate(const struct nft_ctx *ctx, |
208 | const struct nft_expr *expr, |
209 | const struct nft_data **d) |
210 | { |
211 | const struct nft_lookup *priv = nft_expr_priv(expr); |
212 | struct nft_set_iter iter; |
213 | |
214 | if (!(priv->set->flags & NFT_SET_MAP) || |
215 | priv->set->dtype != NFT_DATA_VERDICT) |
216 | return 0; |
217 | |
218 | iter.genmask = nft_genmask_next(net: ctx->net); |
219 | iter.skip = 0; |
220 | iter.count = 0; |
221 | iter.err = 0; |
222 | iter.fn = nft_setelem_validate; |
223 | |
224 | priv->set->ops->walk(ctx, priv->set, &iter); |
225 | if (!iter.err) |
226 | iter.err = nft_set_catchall_validate(ctx, set: priv->set); |
227 | |
228 | if (iter.err < 0) |
229 | return iter.err; |
230 | |
231 | return 0; |
232 | } |
233 | |
234 | static bool nft_lookup_reduce(struct nft_regs_track *track, |
235 | const struct nft_expr *expr) |
236 | { |
237 | const struct nft_lookup *priv = nft_expr_priv(expr); |
238 | |
239 | if (priv->set->flags & NFT_SET_MAP) |
240 | nft_reg_track_cancel(track, dreg: priv->dreg, len: priv->set->dlen); |
241 | |
242 | return false; |
243 | } |
244 | |
245 | static const struct nft_expr_ops nft_lookup_ops = { |
246 | .type = &nft_lookup_type, |
247 | .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)), |
248 | .eval = nft_lookup_eval, |
249 | .init = nft_lookup_init, |
250 | .activate = nft_lookup_activate, |
251 | .deactivate = nft_lookup_deactivate, |
252 | .destroy = nft_lookup_destroy, |
253 | .dump = nft_lookup_dump, |
254 | .validate = nft_lookup_validate, |
255 | .reduce = nft_lookup_reduce, |
256 | }; |
257 | |
258 | struct nft_expr_type nft_lookup_type __read_mostly = { |
259 | .name = "lookup" , |
260 | .ops = &nft_lookup_ops, |
261 | .policy = nft_lookup_policy, |
262 | .maxattr = NFTA_LOOKUP_MAX, |
263 | .owner = THIS_MODULE, |
264 | }; |
265 | |