1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org>
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(chain: ctx->chain, hook_flags: 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, type: 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(net: 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(net: ctx->net, table: ctx->table,
68 nla: tb[NFTA_OBJREF_IMM_NAME], objtype,
69 genmask);
70 if (IS_ERR(ptr: obj))
71 return -ENOENT;
72
73 if (!nft_use_inc(use: &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, attrtype: NFTA_OBJREF_IMM_NAME, str: obj->key.name) ||
87 nla_put_be32(skb, attrtype: 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(use: &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(use: &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 .reduce = NFT_REDUCE_READONLY,
127};
128
129struct nft_objref_map {
130 struct nft_set *set;
131 u8 sreg;
132 struct nft_set_binding binding;
133};
134
135void nft_objref_map_eval(const struct nft_expr *expr,
136 struct nft_regs *regs,
137 const struct nft_pktinfo *pkt)
138{
139 struct nft_objref_map *priv = nft_expr_priv(expr);
140 const struct nft_set *set = priv->set;
141 struct net *net = nft_net(pkt);
142 const struct nft_set_ext *ext;
143 struct nft_object *obj;
144
145 ext = nft_set_do_lookup(net, set, key: &regs->data[priv->sreg]);
146 if (!ext) {
147 ext = nft_set_catchall_lookup(net, set);
148 if (!ext) {
149 regs->verdict.code = NFT_BREAK;
150 return;
151 }
152 }
153 obj = *nft_set_ext_obj(ext);
154 obj->ops->eval(obj, regs, pkt);
155}
156
157static int nft_objref_map_init(const struct nft_ctx *ctx,
158 const struct nft_expr *expr,
159 const struct nlattr * const tb[])
160{
161 struct nft_objref_map *priv = nft_expr_priv(expr);
162 u8 genmask = nft_genmask_next(net: ctx->net);
163 struct nft_set *set;
164 int err;
165
166 set = nft_set_lookup_global(net: ctx->net, table: ctx->table,
167 nla_set_name: tb[NFTA_OBJREF_SET_NAME],
168 nla_set_id: tb[NFTA_OBJREF_SET_ID], genmask);
169 if (IS_ERR(ptr: set))
170 return PTR_ERR(ptr: set);
171
172 if (!(set->flags & NFT_SET_OBJECT))
173 return -EINVAL;
174
175 err = nft_parse_register_load(ctx, attr: tb[NFTA_OBJREF_SET_SREG], sreg: &priv->sreg,
176 len: set->klen);
177 if (err < 0)
178 return err;
179
180 priv->binding.flags = set->flags & NFT_SET_OBJECT;
181
182 err = nf_tables_bind_set(ctx, set, binding: &priv->binding);
183 if (err < 0)
184 return err;
185
186 priv->set = set;
187 return 0;
188}
189
190static int nft_objref_map_dump(struct sk_buff *skb,
191 const struct nft_expr *expr, bool reset)
192{
193 const struct nft_objref_map *priv = nft_expr_priv(expr);
194
195 if (nft_dump_register(skb, attr: NFTA_OBJREF_SET_SREG, reg: priv->sreg) ||
196 nla_put_string(skb, attrtype: NFTA_OBJREF_SET_NAME, str: priv->set->name))
197 goto nla_put_failure;
198
199 return 0;
200
201nla_put_failure:
202 return -1;
203}
204
205static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
206 const struct nft_expr *expr,
207 enum nft_trans_phase phase)
208{
209 struct nft_objref_map *priv = nft_expr_priv(expr);
210
211 nf_tables_deactivate_set(ctx, set: priv->set, binding: &priv->binding, phase);
212}
213
214static void nft_objref_map_activate(const struct nft_ctx *ctx,
215 const struct nft_expr *expr)
216{
217 struct nft_objref_map *priv = nft_expr_priv(expr);
218
219 nf_tables_activate_set(ctx, set: priv->set);
220}
221
222static void nft_objref_map_destroy(const struct nft_ctx *ctx,
223 const struct nft_expr *expr)
224{
225 struct nft_objref_map *priv = nft_expr_priv(expr);
226
227 nf_tables_destroy_set(ctx, set: priv->set);
228}
229
230static int nft_objref_map_validate(const struct nft_ctx *ctx,
231 const struct nft_expr *expr)
232{
233 const struct nft_objref_map *priv = nft_expr_priv(expr);
234
235 return nft_objref_validate_obj_type(ctx, type: priv->set->objtype);
236}
237
238static const struct nft_expr_ops nft_objref_map_ops = {
239 .type = &nft_objref_type,
240 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
241 .eval = nft_objref_map_eval,
242 .init = nft_objref_map_init,
243 .activate = nft_objref_map_activate,
244 .deactivate = nft_objref_map_deactivate,
245 .destroy = nft_objref_map_destroy,
246 .dump = nft_objref_map_dump,
247 .validate = nft_objref_map_validate,
248 .reduce = NFT_REDUCE_READONLY,
249};
250
251static const struct nft_expr_ops *
252nft_objref_select_ops(const struct nft_ctx *ctx,
253 const struct nlattr * const tb[])
254{
255 if (tb[NFTA_OBJREF_SET_SREG] &&
256 (tb[NFTA_OBJREF_SET_NAME] ||
257 tb[NFTA_OBJREF_SET_ID]))
258 return &nft_objref_map_ops;
259 else if (tb[NFTA_OBJREF_IMM_NAME] &&
260 tb[NFTA_OBJREF_IMM_TYPE])
261 return &nft_objref_ops;
262
263 return ERR_PTR(error: -EOPNOTSUPP);
264}
265
266static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
267 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING,
268 .len = NFT_OBJ_MAXNAMELEN - 1 },
269 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 },
270 [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 },
271 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING,
272 .len = NFT_SET_MAXNAMELEN - 1 },
273 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 },
274};
275
276struct nft_expr_type nft_objref_type __read_mostly = {
277 .name = "objref",
278 .select_ops = nft_objref_select_ops,
279 .policy = nft_objref_policy,
280 .maxattr = NFTA_OBJREF_MAX,
281 .owner = THIS_MODULE,
282};
283

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