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
18struct 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
28bool 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}
55EXPORT_SYMBOL_GPL(nft_set_do_lookup);
56#endif
57
58void 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, &regs->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: &regs->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
87static 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
97static 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
161static 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
170static 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
178static 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
186static 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
203nla_put_failure:
204 return -1;
205}
206
207static 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
234static 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
245static 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
258struct 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

source code of linux/net/netfilter/nft_lookup.c