tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/list.h>
14#include <linux/rbtree.h>
15#include <linux/netlink.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables.h>
19#include <net/netfilter/nf_tables_core.h>
20
21struct nft_lookup {
22 struct nft_set *set;
23 enum nft_registers sreg:8;
24 enum nft_registers dreg:8;
25 bool invert;
26 struct nft_set_binding binding;
27};
28
29void nft_lookup_eval(const struct nft_expr *expr,
30 struct nft_regs *regs,
31 const struct nft_pktinfo *pkt)
32{
33 const struct nft_lookup *priv = nft_expr_priv(expr);
34 const struct nft_set *set = priv->set;
35 const struct nft_set_ext *ext;
36 bool found;
37
38 found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg],
39 &ext) ^ priv->invert;
40 if (!found) {
41 regs->verdict.code = NFT_BREAK;
42 return;
43 }
44
45 if (set->flags & NFT_SET_MAP)
46 nft_data_copy(®s->data[priv->dreg],
47 nft_set_ext_data(ext), set->dlen);
48
49}
50
51static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = {
52 [NFTA_LOOKUP_SET] = { .type = NLA_STRING,
53 .len = NFT_SET_MAXNAMELEN - 1 },
54 [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 },
55 [NFTA_LOOKUP_SREG] = { .type = NLA_U32 },
56 [NFTA_LOOKUP_DREG] = { .type = NLA_U32 },
57 [NFTA_LOOKUP_FLAGS] = { .type = NLA_U32 },
58};
59
60static int nft_lookup_init(const struct nft_ctx *ctx,
61 const struct nft_expr *expr,
62 const struct nlattr * const tb[])
63{
64 struct nft_lookup *priv = nft_expr_priv(expr);
65 u8 genmask = nft_genmask_next(ctx->net);
66 struct nft_set *set;
67 u32 flags;
68 int err;
69
70 if (tb[NFTA_LOOKUP_SET] == NULL ||
71 tb[NFTA_LOOKUP_SREG] == NULL)
72 return -EINVAL;
73
74 set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET],
75 tb[NFTA_LOOKUP_SET_ID], genmask);
76 if (IS_ERR(set))
77 return PTR_ERR(set);
78
79 if (set->flags & NFT_SET_EVAL)
80 return -EOPNOTSUPP;
81
82 priv->sreg = nft_parse_register(tb[NFTA_LOOKUP_SREG]);
83 err = nft_validate_register_load(priv->sreg, set->klen);
84 if (err < 0)
85 return err;
86
87 if (tb[NFTA_LOOKUP_FLAGS]) {
88 flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS]));
89
90 if (flags & ~NFT_LOOKUP_F_INV)
91 return -EINVAL;
92
93 if (flags & NFT_LOOKUP_F_INV) {
94 if (set->flags & NFT_SET_MAP)
95 return -EINVAL;
96 priv->invert = true;
97 }
98 }
99
100 if (tb[NFTA_LOOKUP_DREG] != NULL) {
101 if (priv->invert)
102 return -EINVAL;
103 if (!(set->flags & NFT_SET_MAP))
104 return -EINVAL;
105
106 priv->dreg = nft_parse_register(tb[NFTA_LOOKUP_DREG]);
107 err = nft_validate_register_store(ctx, priv->dreg, NULL,
108 set->dtype, set->dlen);
109 if (err < 0)
110 return err;
111 } else if (set->flags & NFT_SET_MAP)
112 return -EINVAL;
113
114 priv->binding.flags = set->flags & NFT_SET_MAP;
115
116 err = nf_tables_bind_set(ctx, set, &priv->binding);
117 if (err < 0)
118 return err;
119
120 priv->set = set;
121 return 0;
122}
123
124static void nft_lookup_deactivate(const struct nft_ctx *ctx,
125 const struct nft_expr *expr,
126 enum nft_trans_phase phase)
127{
128 struct nft_lookup *priv = nft_expr_priv(expr);
129
130 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
131}
132
133static void nft_lookup_activate(const struct nft_ctx *ctx,
134 const struct nft_expr *expr)
135{
136 struct nft_lookup *priv = nft_expr_priv(expr);
137
138 priv->set->use++;
139}
140
141static void nft_lookup_destroy(const struct nft_ctx *ctx,
142 const struct nft_expr *expr)
143{
144 struct nft_lookup *priv = nft_expr_priv(expr);
145
146 nf_tables_destroy_set(ctx, priv->set);
147}
148
149static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr)
150{
151 const struct nft_lookup *priv = nft_expr_priv(expr);
152 u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0;
153
154 if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
155 goto nla_put_failure;
156 if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg))
157 goto nla_put_failure;
158 if (priv->set->flags & NFT_SET_MAP)
159 if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg))
160 goto nla_put_failure;
161 if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags)))
162 goto nla_put_failure;
163 return 0;
164
165nla_put_failure:
166 return -1;
167}
168
169static int nft_lookup_validate_setelem(const struct nft_ctx *ctx,
170 struct nft_set *set,
171 const struct nft_set_iter *iter,
172 struct nft_set_elem *elem)
173{
174 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
175 struct nft_ctx *pctx = (struct nft_ctx *)ctx;
176 const struct nft_data *data;
177 int err;
178
179 if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) &&
180 *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END)
181 return 0;
182
183 data = nft_set_ext_data(ext);
184 switch (data->verdict.code) {
185 case NFT_JUMP:
186 case NFT_GOTO:
187 pctx->level++;
188 err = nft_chain_validate(ctx, data->verdict.chain);
189 if (err < 0)
190 return err;
191 pctx->level--;
192 break;
193 default:
194 break;
195 }
196
197 return 0;
198}
199
200static int nft_lookup_validate(const struct nft_ctx *ctx,
201 const struct nft_expr *expr,
202 const struct nft_data **d)
203{
204 const struct nft_lookup *priv = nft_expr_priv(expr);
205 struct nft_set_iter iter;
206
207 if (!(priv->set->flags & NFT_SET_MAP) ||
208 priv->set->dtype != NFT_DATA_VERDICT)
209 return 0;
210
211 iter.genmask = nft_genmask_next(ctx->net);
212 iter.skip = 0;
213 iter.count = 0;
214 iter.err = 0;
215 iter.fn = nft_lookup_validate_setelem;
216
217 priv->set->ops->walk(ctx, priv->set, &iter);
218 if (iter.err < 0)
219 return iter.err;
220
221 return 0;
222}
223
224static const struct nft_expr_ops nft_lookup_ops = {
225 .type = &nft_lookup_type,
226 .size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
227 .eval = nft_lookup_eval,
228 .init = nft_lookup_init,
229 .activate = nft_lookup_activate,
230 .deactivate = nft_lookup_deactivate,
231 .destroy = nft_lookup_destroy,
232 .dump = nft_lookup_dump,
233 .validate = nft_lookup_validate,
234};
235
236struct nft_expr_type nft_lookup_type __read_mostly = {
237 .name = "lookup",
238 .ops = &nft_lookup_ops,
239 .policy = nft_lookup_policy,
240 .maxattr = NFTA_LOOKUP_MAX,
241 .owner = THIS_MODULE,
242};