Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
4 */
5
6#include <linux/kernel.h>
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/netlink.h>
10#include <linux/netfilter.h>
11#include <linux/netfilter/nf_tables.h>
12#include <net/netfilter/nf_tables.h>
13#include <net/netfilter/nf_nat.h>
14#include <net/netfilter/nf_nat_masquerade.h>
15
16struct nft_masq {
17 u32 flags;
18 u8 sreg_proto_min;
19 u8 sreg_proto_max;
20};
21
22static const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
23 [NFTA_MASQ_FLAGS] =
24 NLA_POLICY_MASK(NLA_BE32, NF_NAT_RANGE_MASK),
25 [NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 },
26 [NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 },
27};
28
29static int nft_masq_validate(const struct nft_ctx *ctx,
30 const struct nft_expr *expr)
31{
32 int err;
33
34 err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
35 if (err < 0)
36 return err;
37
38 return nft_chain_validate_hooks(ctx->chain,
39 (1 << NF_INET_POST_ROUTING));
40}
41
42static int nft_masq_init(const struct nft_ctx *ctx,
43 const struct nft_expr *expr,
44 const struct nlattr * const tb[])
45{
46 u32 plen = sizeof_field(struct nf_nat_range, min_proto.all);
47 struct nft_masq *priv = nft_expr_priv(expr);
48 int err;
49
50 if (tb[NFTA_MASQ_FLAGS])
51 priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
52
53 if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
54 err = nft_parse_register_load(ctx, tb[NFTA_MASQ_REG_PROTO_MIN],
55 &priv->sreg_proto_min, plen);
56 if (err < 0)
57 return err;
58
59 if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
60 err = nft_parse_register_load(ctx, tb[NFTA_MASQ_REG_PROTO_MAX],
61 &priv->sreg_proto_max,
62 plen);
63 if (err < 0)
64 return err;
65 } else {
66 priv->sreg_proto_max = priv->sreg_proto_min;
67 }
68 }
69
70 return nf_ct_netns_get(ctx->net, ctx->family);
71}
72
73static int nft_masq_dump(struct sk_buff *skb,
74 const struct nft_expr *expr, bool reset)
75{
76 const struct nft_masq *priv = nft_expr_priv(expr);
77
78 if (priv->flags != 0 &&
79 nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
80 goto nla_put_failure;
81
82 if (priv->sreg_proto_min) {
83 if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
84 priv->sreg_proto_min) ||
85 nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX,
86 priv->sreg_proto_max))
87 goto nla_put_failure;
88 }
89
90 return 0;
91
92nla_put_failure:
93 return -1;
94}
95
96static void nft_masq_eval(const struct nft_expr *expr,
97 struct nft_regs *regs,
98 const struct nft_pktinfo *pkt)
99{
100 const struct nft_masq *priv = nft_expr_priv(expr);
101 struct nf_nat_range2 range;
102
103 memset(&range, 0, sizeof(range));
104 range.flags = priv->flags;
105 if (priv->sreg_proto_min) {
106 range.min_proto.all = (__force __be16)
107 nft_reg_load16(®s->data[priv->sreg_proto_min]);
108 range.max_proto.all = (__force __be16)
109 nft_reg_load16(®s->data[priv->sreg_proto_max]);
110 }
111
112 switch (nft_pf(pkt)) {
113 case NFPROTO_IPV4:
114 regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb,
115 nft_hook(pkt),
116 &range,
117 nft_out(pkt));
118 break;
119#ifdef CONFIG_NF_TABLES_IPV6
120 case NFPROTO_IPV6:
121 regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range,
122 nft_out(pkt));
123 break;
124#endif
125 default:
126 WARN_ON_ONCE(1);
127 break;
128 }
129}
130
131static void
132nft_masq_ipv4_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
133{
134 nf_ct_netns_put(ctx->net, NFPROTO_IPV4);
135}
136
137static struct nft_expr_type nft_masq_ipv4_type;
138static const struct nft_expr_ops nft_masq_ipv4_ops = {
139 .type = &nft_masq_ipv4_type,
140 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
141 .eval = nft_masq_eval,
142 .init = nft_masq_init,
143 .destroy = nft_masq_ipv4_destroy,
144 .dump = nft_masq_dump,
145 .validate = nft_masq_validate,
146};
147
148static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
149 .family = NFPROTO_IPV4,
150 .name = "masq",
151 .ops = &nft_masq_ipv4_ops,
152 .policy = nft_masq_policy,
153 .maxattr = NFTA_MASQ_MAX,
154 .owner = THIS_MODULE,
155};
156
157#ifdef CONFIG_NF_TABLES_IPV6
158static void
159nft_masq_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
160{
161 nf_ct_netns_put(ctx->net, NFPROTO_IPV6);
162}
163
164static struct nft_expr_type nft_masq_ipv6_type;
165static const struct nft_expr_ops nft_masq_ipv6_ops = {
166 .type = &nft_masq_ipv6_type,
167 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
168 .eval = nft_masq_eval,
169 .init = nft_masq_init,
170 .destroy = nft_masq_ipv6_destroy,
171 .dump = nft_masq_dump,
172 .validate = nft_masq_validate,
173};
174
175static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
176 .family = NFPROTO_IPV6,
177 .name = "masq",
178 .ops = &nft_masq_ipv6_ops,
179 .policy = nft_masq_policy,
180 .maxattr = NFTA_MASQ_MAX,
181 .owner = THIS_MODULE,
182};
183
184static int __init nft_masq_module_init_ipv6(void)
185{
186 return nft_register_expr(&nft_masq_ipv6_type);
187}
188
189static void nft_masq_module_exit_ipv6(void)
190{
191 nft_unregister_expr(&nft_masq_ipv6_type);
192}
193#else
194static inline int nft_masq_module_init_ipv6(void) { return 0; }
195static inline void nft_masq_module_exit_ipv6(void) {}
196#endif
197
198#ifdef CONFIG_NF_TABLES_INET
199static void
200nft_masq_inet_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
201{
202 nf_ct_netns_put(ctx->net, NFPROTO_INET);
203}
204
205static struct nft_expr_type nft_masq_inet_type;
206static const struct nft_expr_ops nft_masq_inet_ops = {
207 .type = &nft_masq_inet_type,
208 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
209 .eval = nft_masq_eval,
210 .init = nft_masq_init,
211 .destroy = nft_masq_inet_destroy,
212 .dump = nft_masq_dump,
213 .validate = nft_masq_validate,
214};
215
216static struct nft_expr_type nft_masq_inet_type __read_mostly = {
217 .family = NFPROTO_INET,
218 .name = "masq",
219 .ops = &nft_masq_inet_ops,
220 .policy = nft_masq_policy,
221 .maxattr = NFTA_MASQ_MAX,
222 .owner = THIS_MODULE,
223};
224
225static int __init nft_masq_module_init_inet(void)
226{
227 return nft_register_expr(&nft_masq_inet_type);
228}
229
230static void nft_masq_module_exit_inet(void)
231{
232 nft_unregister_expr(&nft_masq_inet_type);
233}
234#else
235static inline int nft_masq_module_init_inet(void) { return 0; }
236static inline void nft_masq_module_exit_inet(void) {}
237#endif
238
239static int __init nft_masq_module_init(void)
240{
241 int ret;
242
243 ret = nft_masq_module_init_ipv6();
244 if (ret < 0)
245 return ret;
246
247 ret = nft_masq_module_init_inet();
248 if (ret < 0) {
249 nft_masq_module_exit_ipv6();
250 return ret;
251 }
252
253 ret = nft_register_expr(&nft_masq_ipv4_type);
254 if (ret < 0) {
255 nft_masq_module_exit_inet();
256 nft_masq_module_exit_ipv6();
257 return ret;
258 }
259
260 ret = nf_nat_masquerade_inet_register_notifiers();
261 if (ret < 0) {
262 nft_masq_module_exit_ipv6();
263 nft_masq_module_exit_inet();
264 nft_unregister_expr(&nft_masq_ipv4_type);
265 return ret;
266 }
267
268 return ret;
269}
270
271static void __exit nft_masq_module_exit(void)
272{
273 nft_masq_module_exit_ipv6();
274 nft_masq_module_exit_inet();
275 nft_unregister_expr(&nft_masq_ipv4_type);
276 nf_nat_masquerade_inet_unregister_notifiers();
277}
278
279module_init(nft_masq_module_init);
280module_exit(nft_masq_module_exit);
281
282MODULE_LICENSE("GPL");
283MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
284MODULE_ALIAS_NFT_EXPR("masq");
285MODULE_DESCRIPTION("Netfilter nftables masquerade expression support");