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280 lines · 6.9 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2012-2016 Pablo Neira Ayuso <[email protected]>
4 */
5
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/skbuff.h>
9#include <linux/netlink.h>
10#include <linux/netfilter.h>
11#include <linux/netfilter/nf_tables.h>
12#include <net/netfilter/nf_tables_core.h>
13
14#define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr))
15
16void nft_objref_eval(const struct nft_expr *expr,
17 struct nft_regs *regs,
18 const struct nft_pktinfo *pkt)
19{
20 struct nft_object *obj = nft_objref_priv(expr);
21
22 obj->ops->eval(obj, regs, pkt);
23}
24
25static int nft_objref_validate_obj_type(const struct nft_ctx *ctx, u32 type)
26{
27 unsigned int hooks;
28
29 switch (type) {
30 case NFT_OBJECT_SYNPROXY:
31 if (ctx->family != NFPROTO_IPV4 &&
32 ctx->family != NFPROTO_IPV6 &&
33 ctx->family != NFPROTO_INET)
34 return -EOPNOTSUPP;
35
36 hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD);
37
38 return nft_chain_validate_hooks(ctx->chain, hooks);
39 default:
40 break;
41 }
42
43 return 0;
44}
45
46static int nft_objref_validate(const struct nft_ctx *ctx,
47 const struct nft_expr *expr)
48{
49 struct nft_object *obj = nft_objref_priv(expr);
50
51 return nft_objref_validate_obj_type(ctx, obj->ops->type->type);
52}
53
54static int nft_objref_init(const struct nft_ctx *ctx,
55 const struct nft_expr *expr,
56 const struct nlattr * const tb[])
57{
58 struct nft_object *obj = nft_objref_priv(expr);
59 u8 genmask = nft_genmask_next(ctx->net);
60 u32 objtype;
61
62 if (!tb[NFTA_OBJREF_IMM_NAME] ||
63 !tb[NFTA_OBJREF_IMM_TYPE])
64 return -EINVAL;
65
66 objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
67 obj = nft_obj_lookup(ctx->net, ctx->table,
68 tb[NFTA_OBJREF_IMM_NAME], objtype,
69 genmask);
70 if (IS_ERR(obj))
71 return -ENOENT;
72
73 if (!nft_use_inc(&obj->use))
74 return -EMFILE;
75
76 nft_objref_priv(expr) = obj;
77
78 return 0;
79}
80
81static int nft_objref_dump(struct sk_buff *skb,
82 const struct nft_expr *expr, bool reset)
83{
84 const struct nft_object *obj = nft_objref_priv(expr);
85
86 if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) ||
87 nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE,
88 htonl(obj->ops->type->type)))
89 goto nla_put_failure;
90
91 return 0;
92
93nla_put_failure:
94 return -1;
95}
96
97static void nft_objref_deactivate(const struct nft_ctx *ctx,
98 const struct nft_expr *expr,
99 enum nft_trans_phase phase)
100{
101 struct nft_object *obj = nft_objref_priv(expr);
102
103 if (phase == NFT_TRANS_COMMIT)
104 return;
105
106 nft_use_dec(&obj->use);
107}
108
109static void nft_objref_activate(const struct nft_ctx *ctx,
110 const struct nft_expr *expr)
111{
112 struct nft_object *obj = nft_objref_priv(expr);
113
114 nft_use_inc_restore(&obj->use);
115}
116
117static const struct nft_expr_ops nft_objref_ops = {
118 .type = &nft_objref_type,
119 .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)),
120 .eval = nft_objref_eval,
121 .init = nft_objref_init,
122 .activate = nft_objref_activate,
123 .deactivate = nft_objref_deactivate,
124 .dump = nft_objref_dump,
125 .validate = nft_objref_validate,
126};
127
128struct nft_objref_map {
129 struct nft_set *set;
130 u8 sreg;
131 struct nft_set_binding binding;
132};
133
134void nft_objref_map_eval(const struct nft_expr *expr,
135 struct nft_regs *regs,
136 const struct nft_pktinfo *pkt)
137{
138 struct nft_objref_map *priv = nft_expr_priv(expr);
139 const struct nft_set *set = priv->set;
140 struct net *net = nft_net(pkt);
141 const struct nft_set_ext *ext;
142 struct nft_object *obj;
143
144 ext = nft_set_do_lookup(net, set, &regs->data[priv->sreg]);
145 if (!ext) {
146 ext = nft_set_catchall_lookup(net, set);
147 if (!ext) {
148 regs->verdict.code = NFT_BREAK;
149 return;
150 }
151 }
152 obj = *nft_set_ext_obj(ext);
153 obj->ops->eval(obj, regs, pkt);
154}
155
156static int nft_objref_map_init(const struct nft_ctx *ctx,
157 const struct nft_expr *expr,
158 const struct nlattr * const tb[])
159{
160 struct nft_objref_map *priv = nft_expr_priv(expr);
161 u8 genmask = nft_genmask_next(ctx->net);
162 struct nft_set *set;
163 int err;
164
165 set = nft_set_lookup_global(ctx->net, ctx->table,
166 tb[NFTA_OBJREF_SET_NAME],
167 tb[NFTA_OBJREF_SET_ID], genmask);
168 if (IS_ERR(set))
169 return PTR_ERR(set);
170
171 if (!(set->flags & NFT_SET_OBJECT))
172 return -EINVAL;
173
174 err = nft_parse_register_load(ctx, tb[NFTA_OBJREF_SET_SREG], &priv->sreg,
175 set->klen);
176 if (err < 0)
177 return err;
178
179 priv->binding.flags = set->flags & NFT_SET_OBJECT;
180
181 err = nf_tables_bind_set(ctx, set, &priv->binding);
182 if (err < 0)
183 return err;
184
185 priv->set = set;
186 return 0;
187}
188
189static int nft_objref_map_dump(struct sk_buff *skb,
190 const struct nft_expr *expr, bool reset)
191{
192 const struct nft_objref_map *priv = nft_expr_priv(expr);
193
194 if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) ||
195 nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name))
196 goto nla_put_failure;
197
198 return 0;
199
200nla_put_failure:
201 return -1;
202}
203
204static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
205 const struct nft_expr *expr,
206 enum nft_trans_phase phase)
207{
208 struct nft_objref_map *priv = nft_expr_priv(expr);
209
210 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
211}
212
213static void nft_objref_map_activate(const struct nft_ctx *ctx,
214 const struct nft_expr *expr)
215{
216 struct nft_objref_map *priv = nft_expr_priv(expr);
217
218 nf_tables_activate_set(ctx, priv->set);
219}
220
221static void nft_objref_map_destroy(const struct nft_ctx *ctx,
222 const struct nft_expr *expr)
223{
224 struct nft_objref_map *priv = nft_expr_priv(expr);
225
226 nf_tables_destroy_set(ctx, priv->set);
227}
228
229static int nft_objref_map_validate(const struct nft_ctx *ctx,
230 const struct nft_expr *expr)
231{
232 const struct nft_objref_map *priv = nft_expr_priv(expr);
233
234 return nft_objref_validate_obj_type(ctx, priv->set->objtype);
235}
236
237static const struct nft_expr_ops nft_objref_map_ops = {
238 .type = &nft_objref_type,
239 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
240 .eval = nft_objref_map_eval,
241 .init = nft_objref_map_init,
242 .activate = nft_objref_map_activate,
243 .deactivate = nft_objref_map_deactivate,
244 .destroy = nft_objref_map_destroy,
245 .dump = nft_objref_map_dump,
246 .validate = nft_objref_map_validate,
247};
248
249static const struct nft_expr_ops *
250nft_objref_select_ops(const struct nft_ctx *ctx,
251 const struct nlattr * const tb[])
252{
253 if (tb[NFTA_OBJREF_SET_SREG] &&
254 (tb[NFTA_OBJREF_SET_NAME] ||
255 tb[NFTA_OBJREF_SET_ID]))
256 return &nft_objref_map_ops;
257 else if (tb[NFTA_OBJREF_IMM_NAME] &&
258 tb[NFTA_OBJREF_IMM_TYPE])
259 return &nft_objref_ops;
260
261 return ERR_PTR(-EOPNOTSUPP);
262}
263
264static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
265 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING,
266 .len = NFT_OBJ_MAXNAMELEN - 1 },
267 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 },
268 [NFTA_OBJREF_SET_SREG] = NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),
269 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING,
270 .len = NFT_SET_MAXNAMELEN - 1 },
271 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 },
272};
273
274struct nft_expr_type nft_objref_type __read_mostly = {
275 .name = "objref",
276 .select_ops = nft_objref_select_ops,
277 .policy = nft_objref_policy,
278 .maxattr = NFTA_OBJREF_MAX,
279 .owner = THIS_MODULE,
280};