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c97d22e6 PNA |
1 | /* |
2 | * Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | #include <linux/init.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.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 | ||
17 | #define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr)) | |
18 | ||
19 | static void nft_objref_eval(const struct nft_expr *expr, | |
20 | struct nft_regs *regs, | |
21 | const struct nft_pktinfo *pkt) | |
22 | { | |
23 | struct nft_object *obj = nft_objref_priv(expr); | |
24 | ||
25 | obj->type->eval(obj, regs, pkt); | |
26 | } | |
27 | ||
28 | static int nft_objref_init(const struct nft_ctx *ctx, | |
29 | const struct nft_expr *expr, | |
30 | const struct nlattr * const tb[]) | |
31 | { | |
32 | struct nft_object *obj = nft_objref_priv(expr); | |
33 | u8 genmask = nft_genmask_next(ctx->net); | |
34 | u32 objtype; | |
35 | ||
36 | if (!tb[NFTA_OBJREF_IMM_NAME] || | |
37 | !tb[NFTA_OBJREF_IMM_TYPE]) | |
38 | return -EINVAL; | |
39 | ||
40 | objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE])); | |
41 | obj = nf_tables_obj_lookup(ctx->table, tb[NFTA_OBJREF_IMM_NAME], objtype, | |
42 | genmask); | |
43 | if (IS_ERR(obj)) | |
44 | return -ENOENT; | |
45 | ||
46 | nft_objref_priv(expr) = obj; | |
47 | obj->use++; | |
48 | ||
49 | return 0; | |
50 | } | |
51 | ||
52 | static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
53 | { | |
54 | const struct nft_object *obj = nft_objref_priv(expr); | |
55 | ||
56 | if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->name) || | |
57 | nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE, htonl(obj->type->type))) | |
58 | goto nla_put_failure; | |
59 | ||
60 | return 0; | |
61 | ||
62 | nla_put_failure: | |
63 | return -1; | |
64 | } | |
65 | ||
66 | static void nft_objref_destroy(const struct nft_ctx *ctx, | |
67 | const struct nft_expr *expr) | |
68 | { | |
69 | struct nft_object *obj = nft_objref_priv(expr); | |
70 | ||
71 | obj->use--; | |
72 | } | |
73 | ||
74 | static struct nft_expr_type nft_objref_type; | |
75 | static const struct nft_expr_ops nft_objref_ops = { | |
76 | .type = &nft_objref_type, | |
77 | .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), | |
78 | .eval = nft_objref_eval, | |
79 | .init = nft_objref_init, | |
80 | .destroy = nft_objref_destroy, | |
81 | .dump = nft_objref_dump, | |
82 | }; | |
83 | ||
63aea290 PNA |
84 | struct nft_objref_map { |
85 | struct nft_set *set; | |
86 | enum nft_registers sreg:8; | |
87 | struct nft_set_binding binding; | |
88 | }; | |
89 | ||
90 | static void nft_objref_map_eval(const struct nft_expr *expr, | |
91 | struct nft_regs *regs, | |
92 | const struct nft_pktinfo *pkt) | |
93 | { | |
94 | struct nft_objref_map *priv = nft_expr_priv(expr); | |
95 | const struct nft_set *set = priv->set; | |
96 | const struct nft_set_ext *ext; | |
97 | struct nft_object *obj; | |
98 | bool found; | |
99 | ||
100 | found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], | |
101 | &ext); | |
102 | if (!found) { | |
103 | regs->verdict.code = NFT_BREAK; | |
104 | return; | |
105 | } | |
106 | obj = *nft_set_ext_obj(ext); | |
107 | obj->type->eval(obj, regs, pkt); | |
108 | } | |
109 | ||
110 | static int nft_objref_map_init(const struct nft_ctx *ctx, | |
111 | const struct nft_expr *expr, | |
112 | const struct nlattr * const tb[]) | |
113 | { | |
114 | struct nft_objref_map *priv = nft_expr_priv(expr); | |
115 | u8 genmask = nft_genmask_next(ctx->net); | |
116 | struct nft_set *set; | |
117 | int err; | |
118 | ||
c7a72e3f PNA |
119 | set = nft_set_lookup(ctx->net, ctx->table, tb[NFTA_OBJREF_SET_NAME], |
120 | tb[NFTA_OBJREF_SET_ID], genmask); | |
121 | if (IS_ERR(set)) | |
122 | return PTR_ERR(set); | |
63aea290 PNA |
123 | |
124 | if (!(set->flags & NFT_SET_OBJECT)) | |
125 | return -EINVAL; | |
126 | ||
127 | priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); | |
128 | err = nft_validate_register_load(priv->sreg, set->klen); | |
129 | if (err < 0) | |
130 | return err; | |
131 | ||
132 | priv->binding.flags = set->flags & NFT_SET_OBJECT; | |
133 | ||
134 | err = nf_tables_bind_set(ctx, set, &priv->binding); | |
135 | if (err < 0) | |
136 | return err; | |
137 | ||
138 | priv->set = set; | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
143 | { | |
144 | const struct nft_objref_map *priv = nft_expr_priv(expr); | |
145 | ||
146 | if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || | |
147 | nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) | |
148 | goto nla_put_failure; | |
149 | ||
150 | return 0; | |
151 | ||
152 | nla_put_failure: | |
153 | return -1; | |
154 | } | |
155 | ||
156 | static void nft_objref_map_destroy(const struct nft_ctx *ctx, | |
157 | const struct nft_expr *expr) | |
158 | { | |
159 | struct nft_objref_map *priv = nft_expr_priv(expr); | |
160 | ||
161 | nf_tables_unbind_set(ctx, priv->set, &priv->binding); | |
162 | } | |
163 | ||
164 | static struct nft_expr_type nft_objref_type; | |
165 | static const struct nft_expr_ops nft_objref_map_ops = { | |
166 | .type = &nft_objref_type, | |
167 | .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), | |
168 | .eval = nft_objref_map_eval, | |
169 | .init = nft_objref_map_init, | |
170 | .destroy = nft_objref_map_destroy, | |
171 | .dump = nft_objref_map_dump, | |
172 | }; | |
173 | ||
174 | static const struct nft_expr_ops * | |
175 | nft_objref_select_ops(const struct nft_ctx *ctx, | |
176 | const struct nlattr * const tb[]) | |
177 | { | |
178 | if (tb[NFTA_OBJREF_SET_SREG] && | |
179 | (tb[NFTA_OBJREF_SET_NAME] || | |
180 | tb[NFTA_OBJREF_SET_ID])) | |
181 | return &nft_objref_map_ops; | |
182 | else if (tb[NFTA_OBJREF_IMM_NAME] && | |
183 | tb[NFTA_OBJREF_IMM_TYPE]) | |
184 | return &nft_objref_ops; | |
185 | ||
186 | return ERR_PTR(-EOPNOTSUPP); | |
187 | } | |
188 | ||
c97d22e6 | 189 | static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { |
b2fbd044 LZ |
190 | [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING, |
191 | .len = NFT_OBJ_MAXNAMELEN - 1 }, | |
c97d22e6 | 192 | [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, |
63aea290 | 193 | [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, |
b2fbd044 LZ |
194 | [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING, |
195 | .len = NFT_SET_MAXNAMELEN - 1 }, | |
63aea290 | 196 | [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, |
c97d22e6 PNA |
197 | }; |
198 | ||
199 | static struct nft_expr_type nft_objref_type __read_mostly = { | |
200 | .name = "objref", | |
63aea290 | 201 | .select_ops = nft_objref_select_ops, |
c97d22e6 PNA |
202 | .policy = nft_objref_policy, |
203 | .maxattr = NFTA_OBJREF_MAX, | |
204 | .owner = THIS_MODULE, | |
205 | }; | |
206 | ||
207 | static int __init nft_objref_module_init(void) | |
208 | { | |
209 | return nft_register_expr(&nft_objref_type); | |
210 | } | |
211 | ||
212 | static void __exit nft_objref_module_exit(void) | |
213 | { | |
214 | nft_unregister_expr(&nft_objref_type); | |
215 | } | |
216 | ||
217 | module_init(nft_objref_module_init); | |
218 | module_exit(nft_objref_module_exit); | |
219 | ||
220 | MODULE_LICENSE("GPL"); | |
221 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
222 | MODULE_ALIAS_NFT_EXPR("objref"); |