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_init(const struct nft_ctx *ctx,
26 const struct nft_expr *expr,
27 const struct nlattr * const tb[])
28{
29 struct nft_object *obj = nft_objref_priv(expr);
30 u8 genmask = nft_genmask_next(net: ctx->net);
31 u32 objtype;
32
33 if (!tb[NFTA_OBJREF_IMM_NAME] ||
34 !tb[NFTA_OBJREF_IMM_TYPE])
35 return -EINVAL;
36
37 objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
38 obj = nft_obj_lookup(net: ctx->net, table: ctx->table,
39 nla: tb[NFTA_OBJREF_IMM_NAME], objtype,
40 genmask);
41 if (IS_ERR(ptr: obj))
42 return -ENOENT;
43
44 if (!nft_use_inc(use: &obj->use))
45 return -EMFILE;
46
47 nft_objref_priv(expr) = obj;
48
49 return 0;
50}
51
52static int nft_objref_dump(struct sk_buff *skb,
53 const struct nft_expr *expr, bool reset)
54{
55 const struct nft_object *obj = nft_objref_priv(expr);
56
57 if (nla_put_string(skb, attrtype: NFTA_OBJREF_IMM_NAME, str: obj->key.name) ||
58 nla_put_be32(skb, attrtype: NFTA_OBJREF_IMM_TYPE,
59 htonl(obj->ops->type->type)))
60 goto nla_put_failure;
61
62 return 0;
63
64nla_put_failure:
65 return -1;
66}
67
68static void nft_objref_deactivate(const struct nft_ctx *ctx,
69 const struct nft_expr *expr,
70 enum nft_trans_phase phase)
71{
72 struct nft_object *obj = nft_objref_priv(expr);
73
74 if (phase == NFT_TRANS_COMMIT)
75 return;
76
77 nft_use_dec(use: &obj->use);
78}
79
80static void nft_objref_activate(const struct nft_ctx *ctx,
81 const struct nft_expr *expr)
82{
83 struct nft_object *obj = nft_objref_priv(expr);
84
85 nft_use_inc_restore(use: &obj->use);
86}
87
88static const struct nft_expr_ops nft_objref_ops = {
89 .type = &nft_objref_type,
90 .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)),
91 .eval = nft_objref_eval,
92 .init = nft_objref_init,
93 .activate = nft_objref_activate,
94 .deactivate = nft_objref_deactivate,
95 .dump = nft_objref_dump,
96 .reduce = NFT_REDUCE_READONLY,
97};
98
99struct nft_objref_map {
100 struct nft_set *set;
101 u8 sreg;
102 struct nft_set_binding binding;
103};
104
105void nft_objref_map_eval(const struct nft_expr *expr,
106 struct nft_regs *regs,
107 const struct nft_pktinfo *pkt)
108{
109 struct nft_objref_map *priv = nft_expr_priv(expr);
110 const struct nft_set *set = priv->set;
111 struct net *net = nft_net(pkt);
112 const struct nft_set_ext *ext;
113 struct nft_object *obj;
114 bool found;
115
116 found = nft_set_do_lookup(net, set, key: &regs->data[priv->sreg], ext: &ext);
117 if (!found) {
118 ext = nft_set_catchall_lookup(net, set);
119 if (!ext) {
120 regs->verdict.code = NFT_BREAK;
121 return;
122 }
123 }
124 obj = *nft_set_ext_obj(ext);
125 obj->ops->eval(obj, regs, pkt);
126}
127
128static int nft_objref_map_init(const struct nft_ctx *ctx,
129 const struct nft_expr *expr,
130 const struct nlattr * const tb[])
131{
132 struct nft_objref_map *priv = nft_expr_priv(expr);
133 u8 genmask = nft_genmask_next(net: ctx->net);
134 struct nft_set *set;
135 int err;
136
137 set = nft_set_lookup_global(net: ctx->net, table: ctx->table,
138 nla_set_name: tb[NFTA_OBJREF_SET_NAME],
139 nla_set_id: tb[NFTA_OBJREF_SET_ID], genmask);
140 if (IS_ERR(ptr: set))
141 return PTR_ERR(ptr: set);
142
143 if (!(set->flags & NFT_SET_OBJECT))
144 return -EINVAL;
145
146 err = nft_parse_register_load(attr: tb[NFTA_OBJREF_SET_SREG], sreg: &priv->sreg,
147 len: set->klen);
148 if (err < 0)
149 return err;
150
151 priv->binding.flags = set->flags & NFT_SET_OBJECT;
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 int nft_objref_map_dump(struct sk_buff *skb,
162 const struct nft_expr *expr, bool reset)
163{
164 const struct nft_objref_map *priv = nft_expr_priv(expr);
165
166 if (nft_dump_register(skb, attr: NFTA_OBJREF_SET_SREG, reg: priv->sreg) ||
167 nla_put_string(skb, attrtype: NFTA_OBJREF_SET_NAME, str: priv->set->name))
168 goto nla_put_failure;
169
170 return 0;
171
172nla_put_failure:
173 return -1;
174}
175
176static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
177 const struct nft_expr *expr,
178 enum nft_trans_phase phase)
179{
180 struct nft_objref_map *priv = nft_expr_priv(expr);
181
182 nf_tables_deactivate_set(ctx, set: priv->set, binding: &priv->binding, phase);
183}
184
185static void nft_objref_map_activate(const struct nft_ctx *ctx,
186 const struct nft_expr *expr)
187{
188 struct nft_objref_map *priv = nft_expr_priv(expr);
189
190 nf_tables_activate_set(ctx, set: priv->set);
191}
192
193static void nft_objref_map_destroy(const struct nft_ctx *ctx,
194 const struct nft_expr *expr)
195{
196 struct nft_objref_map *priv = nft_expr_priv(expr);
197
198 nf_tables_destroy_set(ctx, set: priv->set);
199}
200
201static const struct nft_expr_ops nft_objref_map_ops = {
202 .type = &nft_objref_type,
203 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
204 .eval = nft_objref_map_eval,
205 .init = nft_objref_map_init,
206 .activate = nft_objref_map_activate,
207 .deactivate = nft_objref_map_deactivate,
208 .destroy = nft_objref_map_destroy,
209 .dump = nft_objref_map_dump,
210 .reduce = NFT_REDUCE_READONLY,
211};
212
213static const struct nft_expr_ops *
214nft_objref_select_ops(const struct nft_ctx *ctx,
215 const struct nlattr * const tb[])
216{
217 if (tb[NFTA_OBJREF_SET_SREG] &&
218 (tb[NFTA_OBJREF_SET_NAME] ||
219 tb[NFTA_OBJREF_SET_ID]))
220 return &nft_objref_map_ops;
221 else if (tb[NFTA_OBJREF_IMM_NAME] &&
222 tb[NFTA_OBJREF_IMM_TYPE])
223 return &nft_objref_ops;
224
225 return ERR_PTR(error: -EOPNOTSUPP);
226}
227
228static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
229 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING,
230 .len = NFT_OBJ_MAXNAMELEN - 1 },
231 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 },
232 [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 },
233 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING,
234 .len = NFT_SET_MAXNAMELEN - 1 },
235 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 },
236};
237
238struct nft_expr_type nft_objref_type __read_mostly = {
239 .name = "objref",
240 .select_ops = nft_objref_select_ops,
241 .policy = nft_objref_policy,
242 .maxattr = NFTA_OBJREF_MAX,
243 .owner = THIS_MODULE,
244};
245

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