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
nft_set_do_lookup(const struct net * net,const struct nft_set * set,const u32 * key,const struct nft_set_ext ** ext)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
nft_lookup_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)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(®s->data[priv->dreg],
81 nft_set_ext_data(ext), 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
nft_lookup_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])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(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(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET],
112 tb[NFTA_LOOKUP_SET_ID], genmask);
113 if (IS_ERR(set))
114 return PTR_ERR(set);
115
116 err = nft_parse_register_load(tb[NFTA_LOOKUP_SREG], &priv->sreg,
117 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, tb[NFTA_LOOKUP_DREG],
135 &priv->dreg, NULL,
136 nft_set_datatype(set),
137 set->dlen);
138 if (err < 0)
139 return err;
140 priv->dreg_set = true;
141 } else if (set->flags & NFT_SET_MAP) {
142 /* Map given, but user asks for lookup only (i.e. to
143 * ignore value assoicated with key).
144 *
145 * This makes no sense for anonymous maps since they are
146 * scoped to the rule, but for named sets this can be useful.
147 */
148 if (set->flags & NFT_SET_ANONYMOUS)
149 return -EINVAL;
150 }
151
152 priv->binding.flags = set->flags & NFT_SET_MAP;
153
154 err = nf_tables_bind_set(ctx, set, &priv->binding);
155 if (err < 0)
156 return err;
157
158 priv->set = set;
159 return 0;
160 }
161
nft_lookup_deactivate(const struct nft_ctx * ctx,const struct nft_expr * expr,enum nft_trans_phase phase)162 static void nft_lookup_deactivate(const struct nft_ctx *ctx,
163 const struct nft_expr *expr,
164 enum nft_trans_phase phase)
165 {
166 struct nft_lookup *priv = nft_expr_priv(expr);
167
168 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
169 }
170
nft_lookup_activate(const struct nft_ctx * ctx,const struct nft_expr * expr)171 static void nft_lookup_activate(const struct nft_ctx *ctx,
172 const struct nft_expr *expr)
173 {
174 struct nft_lookup *priv = nft_expr_priv(expr);
175
176 nf_tables_activate_set(ctx, priv->set);
177 }
178
nft_lookup_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)179 static void nft_lookup_destroy(const struct nft_ctx *ctx,
180 const struct nft_expr *expr)
181 {
182 struct nft_lookup *priv = nft_expr_priv(expr);
183
184 nf_tables_destroy_set(ctx, priv->set);
185 }
186
nft_lookup_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)187 static int nft_lookup_dump(struct sk_buff *skb,
188 const struct nft_expr *expr, bool reset)
189 {
190 const struct nft_lookup *priv = nft_expr_priv(expr);
191 u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0;
192
193 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
194 goto nla_put_failure;
195 if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg))
196 goto nla_put_failure;
197 if (priv->dreg_set)
198 if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg))
199 goto nla_put_failure;
200 if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags)))
201 goto nla_put_failure;
202 return 0;
203
204 nla_put_failure:
205 return -1;
206 }
207
nft_lookup_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** d)208 static int nft_lookup_validate(const struct nft_ctx *ctx,
209 const struct nft_expr *expr,
210 const struct nft_data **d)
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.skip = 0;
221 iter.count = 0;
222 iter.err = 0;
223 iter.fn = nft_setelem_validate;
224
225 priv->set->ops->walk(ctx, priv->set, &iter);
226 if (!iter.err)
227 iter.err = nft_set_catchall_validate(ctx, priv->set);
228
229 if (iter.err < 0)
230 return iter.err;
231
232 return 0;
233 }
234
nft_lookup_reduce(struct nft_regs_track * track,const struct nft_expr * expr)235 static bool nft_lookup_reduce(struct nft_regs_track *track,
236 const struct nft_expr *expr)
237 {
238 const struct nft_lookup *priv = nft_expr_priv(expr);
239
240 if (priv->set->flags & NFT_SET_MAP)
241 nft_reg_track_cancel(track, priv->dreg, priv->set->dlen);
242
243 return false;
244 }
245
246 static const struct nft_expr_ops nft_lookup_ops = {
247 .type = &nft_lookup_type,
248 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
249 .eval = nft_lookup_eval,
250 .init = nft_lookup_init,
251 .activate = nft_lookup_activate,
252 .deactivate = nft_lookup_deactivate,
253 .destroy = nft_lookup_destroy,
254 .dump = nft_lookup_dump,
255 .validate = nft_lookup_validate,
256 .reduce = nft_lookup_reduce,
257 };
258
259 struct nft_expr_type nft_lookup_type __read_mostly = {
260 .name = "lookup",
261 .ops = &nft_lookup_ops,
262 .policy = nft_lookup_policy,
263 .maxattr = NFTA_LOOKUP_MAX,
264 .owner = THIS_MODULE,
265 };
266