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_MITIGATION_RETPOLINE
28 const struct nft_set_ext *
nft_set_do_lookup(const struct net * net,const struct nft_set * set,const u32 * key)29 nft_set_do_lookup(const struct net *net, const struct nft_set *set,
30 const u32 *key)
31 {
32 if (set->ops == &nft_set_hash_fast_type.ops)
33 return nft_hash_lookup_fast(net, set, key);
34 if (set->ops == &nft_set_hash_type.ops)
35 return nft_hash_lookup(net, set, key);
36
37 if (set->ops == &nft_set_rhash_type.ops)
38 return nft_rhash_lookup(net, set, key);
39
40 if (set->ops == &nft_set_bitmap_type.ops)
41 return nft_bitmap_lookup(net, set, key);
42
43 if (set->ops == &nft_set_pipapo_type.ops)
44 return nft_pipapo_lookup(net, set, key);
45 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
46 if (set->ops == &nft_set_pipapo_avx2_type.ops)
47 return nft_pipapo_avx2_lookup(net, set, key);
48 #endif
49
50 if (set->ops == &nft_set_rbtree_type.ops)
51 return nft_rbtree_lookup(net, set, key);
52
53 WARN_ON_ONCE(1);
54 return set->ops->lookup(net, set, key);
55 }
56 EXPORT_SYMBOL_GPL(nft_set_do_lookup);
57 #endif
58
nft_lookup_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)59 void nft_lookup_eval(const struct nft_expr *expr,
60 struct nft_regs *regs,
61 const struct nft_pktinfo *pkt)
62 {
63 const struct nft_lookup *priv = nft_expr_priv(expr);
64 const struct nft_set *set = priv->set;
65 const struct net *net = nft_net(pkt);
66 const struct nft_set_ext *ext;
67 bool found;
68
69 ext = nft_set_do_lookup(net, set, ®s->data[priv->sreg]);
70 found = !!ext ^ priv->invert;
71 if (!found) {
72 ext = nft_set_catchall_lookup(net, set);
73 if (!ext) {
74 regs->verdict.code = NFT_BREAK;
75 return;
76 }
77 }
78
79 if (ext) {
80 if (priv->dreg_set)
81 nft_data_copy(®s->data[priv->dreg],
82 nft_set_ext_data(ext), set->dlen);
83
84 nft_set_elem_update_expr(ext, regs, pkt);
85 }
86 }
87
88 static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = {
89 [NFTA_LOOKUP_SET] = { .type = NLA_STRING,
90 .len = NFT_SET_MAXNAMELEN - 1 },
91 [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 },
92 [NFTA_LOOKUP_SREG] = { .type = NLA_U32 },
93 [NFTA_LOOKUP_DREG] = { .type = NLA_U32 },
94 [NFTA_LOOKUP_FLAGS] =
95 NLA_POLICY_MASK(NLA_BE32, NFT_LOOKUP_F_INV),
96 };
97
nft_lookup_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])98 static int nft_lookup_init(const struct nft_ctx *ctx,
99 const struct nft_expr *expr,
100 const struct nlattr * const tb[])
101 {
102 struct nft_lookup *priv = nft_expr_priv(expr);
103 u8 genmask = nft_genmask_next(ctx->net);
104 struct nft_set *set;
105 u32 flags;
106 int err;
107
108 if (tb[NFTA_LOOKUP_SET] == NULL ||
109 tb[NFTA_LOOKUP_SREG] == NULL)
110 return -EINVAL;
111
112 set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET],
113 tb[NFTA_LOOKUP_SET_ID], genmask);
114 if (IS_ERR(set))
115 return PTR_ERR(set);
116
117 err = nft_parse_register_load(ctx, tb[NFTA_LOOKUP_SREG], &priv->sreg,
118 set->klen);
119 if (err < 0)
120 return err;
121
122 if (tb[NFTA_LOOKUP_FLAGS]) {
123 flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS]));
124
125 if (flags & NFT_LOOKUP_F_INV)
126 priv->invert = true;
127 }
128
129 if (tb[NFTA_LOOKUP_DREG] != NULL) {
130 if (priv->invert)
131 return -EINVAL;
132 if (!(set->flags & NFT_SET_MAP))
133 return -EINVAL;
134
135 err = nft_parse_register_store(ctx, tb[NFTA_LOOKUP_DREG],
136 &priv->dreg, NULL,
137 nft_set_datatype(set),
138 set->dlen);
139 if (err < 0)
140 return err;
141 priv->dreg_set = true;
142 } else if (set->flags & NFT_SET_MAP) {
143 /* Map given, but user asks for lookup only (i.e. to
144 * ignore value assoicated with key).
145 *
146 * This makes no sense for anonymous maps since they are
147 * scoped to the rule, but for named sets this can be useful.
148 */
149 if (set->flags & NFT_SET_ANONYMOUS)
150 return -EINVAL;
151 }
152
153 priv->binding.flags = set->flags & NFT_SET_MAP;
154
155 err = nf_tables_bind_set(ctx, set, &priv->binding);
156 if (err < 0)
157 return err;
158
159 priv->set = set;
160 return 0;
161 }
162
nft_lookup_deactivate(const struct nft_ctx * ctx,const struct nft_expr * expr,enum nft_trans_phase phase)163 static void nft_lookup_deactivate(const struct nft_ctx *ctx,
164 const struct nft_expr *expr,
165 enum nft_trans_phase phase)
166 {
167 struct nft_lookup *priv = nft_expr_priv(expr);
168
169 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
170 }
171
nft_lookup_activate(const struct nft_ctx * ctx,const struct nft_expr * expr)172 static void nft_lookup_activate(const struct nft_ctx *ctx,
173 const struct nft_expr *expr)
174 {
175 struct nft_lookup *priv = nft_expr_priv(expr);
176
177 nf_tables_activate_set(ctx, priv->set);
178 }
179
nft_lookup_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)180 static void nft_lookup_destroy(const struct nft_ctx *ctx,
181 const struct nft_expr *expr)
182 {
183 struct nft_lookup *priv = nft_expr_priv(expr);
184
185 nf_tables_destroy_set(ctx, priv->set);
186 }
187
nft_lookup_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)188 static int nft_lookup_dump(struct sk_buff *skb,
189 const struct nft_expr *expr, bool reset)
190 {
191 const struct nft_lookup *priv = nft_expr_priv(expr);
192 u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0;
193
194 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
195 goto nla_put_failure;
196 if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg))
197 goto nla_put_failure;
198 if (priv->dreg_set)
199 if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg))
200 goto nla_put_failure;
201 if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags)))
202 goto nla_put_failure;
203 return 0;
204
205 nla_put_failure:
206 return -1;
207 }
208
nft_lookup_validate(const struct nft_ctx * ctx,const struct nft_expr * expr)209 static int nft_lookup_validate(const struct nft_ctx *ctx,
210 const struct nft_expr *expr)
211 {
212 const struct nft_lookup *priv = nft_expr_priv(expr);
213 struct nft_set_iter iter;
214
215 if (!(priv->set->flags & NFT_SET_MAP) ||
216 priv->set->dtype != NFT_DATA_VERDICT)
217 return 0;
218
219 iter.genmask = nft_genmask_next(ctx->net);
220 iter.type = NFT_ITER_UPDATE;
221 iter.skip = 0;
222 iter.count = 0;
223 iter.err = 0;
224 iter.fn = nft_setelem_validate;
225
226 priv->set->ops->walk(ctx, priv->set, &iter);
227 if (!iter.err)
228 iter.err = nft_set_catchall_validate(ctx, priv->set);
229
230 if (iter.err < 0)
231 return iter.err;
232
233 return 0;
234 }
235
nft_lookup_reduce(struct nft_regs_track * track,const struct nft_expr * expr)236 static bool nft_lookup_reduce(struct nft_regs_track *track,
237 const struct nft_expr *expr)
238 {
239 const struct nft_lookup *priv = nft_expr_priv(expr);
240
241 if (priv->set->flags & NFT_SET_MAP)
242 nft_reg_track_cancel(track, priv->dreg, priv->set->dlen);
243
244 return false;
245 }
246
247 static const struct nft_expr_ops nft_lookup_ops = {
248 .type = &nft_lookup_type,
249 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
250 .eval = nft_lookup_eval,
251 .init = nft_lookup_init,
252 .activate = nft_lookup_activate,
253 .deactivate = nft_lookup_deactivate,
254 .destroy = nft_lookup_destroy,
255 .dump = nft_lookup_dump,
256 .validate = nft_lookup_validate,
257 .reduce = nft_lookup_reduce,
258 };
259
260 struct nft_expr_type nft_lookup_type __read_mostly = {
261 .name = "lookup",
262 .ops = &nft_lookup_ops,
263 .policy = nft_lookup_policy,
264 .maxattr = NFTA_LOOKUP_MAX,
265 .owner = THIS_MODULE,
266 };
267