Loading...
Note: File does not exist in v3.1.
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] = { .type = NLA_U32 },
24 [NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 },
25 [NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 },
26};
27
28static int nft_masq_validate(const struct nft_ctx *ctx,
29 const struct nft_expr *expr,
30 const struct nft_data **data)
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_addr.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 if (priv->flags & ~NF_NAT_RANGE_MASK)
53 return -EINVAL;
54 }
55
56 if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
57 err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MIN],
58 &priv->sreg_proto_min, plen);
59 if (err < 0)
60 return err;
61
62 if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
63 err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MAX],
64 &priv->sreg_proto_max,
65 plen);
66 if (err < 0)
67 return err;
68 } else {
69 priv->sreg_proto_max = priv->sreg_proto_min;
70 }
71 }
72
73 return nf_ct_netns_get(ctx->net, ctx->family);
74}
75
76static int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
77{
78 const struct nft_masq *priv = nft_expr_priv(expr);
79
80 if (priv->flags != 0 &&
81 nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
82 goto nla_put_failure;
83
84 if (priv->sreg_proto_min) {
85 if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
86 priv->sreg_proto_min) ||
87 nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX,
88 priv->sreg_proto_max))
89 goto nla_put_failure;
90 }
91
92 return 0;
93
94nla_put_failure:
95 return -1;
96}
97
98static void nft_masq_ipv4_eval(const struct nft_expr *expr,
99 struct nft_regs *regs,
100 const struct nft_pktinfo *pkt)
101{
102 struct nft_masq *priv = nft_expr_priv(expr);
103 struct nf_nat_range2 range;
104
105 memset(&range, 0, sizeof(range));
106 range.flags = priv->flags;
107 if (priv->sreg_proto_min) {
108 range.min_proto.all = (__force __be16)nft_reg_load16(
109 ®s->data[priv->sreg_proto_min]);
110 range.max_proto.all = (__force __be16)nft_reg_load16(
111 ®s->data[priv->sreg_proto_max]);
112 }
113 regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, nft_hook(pkt),
114 &range, nft_out(pkt));
115}
116
117static void
118nft_masq_ipv4_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
119{
120 nf_ct_netns_put(ctx->net, NFPROTO_IPV4);
121}
122
123static struct nft_expr_type nft_masq_ipv4_type;
124static const struct nft_expr_ops nft_masq_ipv4_ops = {
125 .type = &nft_masq_ipv4_type,
126 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
127 .eval = nft_masq_ipv4_eval,
128 .init = nft_masq_init,
129 .destroy = nft_masq_ipv4_destroy,
130 .dump = nft_masq_dump,
131 .validate = nft_masq_validate,
132};
133
134static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
135 .family = NFPROTO_IPV4,
136 .name = "masq",
137 .ops = &nft_masq_ipv4_ops,
138 .policy = nft_masq_policy,
139 .maxattr = NFTA_MASQ_MAX,
140 .owner = THIS_MODULE,
141};
142
143#ifdef CONFIG_NF_TABLES_IPV6
144static void nft_masq_ipv6_eval(const struct nft_expr *expr,
145 struct nft_regs *regs,
146 const struct nft_pktinfo *pkt)
147{
148 struct nft_masq *priv = nft_expr_priv(expr);
149 struct nf_nat_range2 range;
150
151 memset(&range, 0, sizeof(range));
152 range.flags = priv->flags;
153 if (priv->sreg_proto_min) {
154 range.min_proto.all = (__force __be16)nft_reg_load16(
155 ®s->data[priv->sreg_proto_min]);
156 range.max_proto.all = (__force __be16)nft_reg_load16(
157 ®s->data[priv->sreg_proto_max]);
158 }
159 regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range,
160 nft_out(pkt));
161}
162
163static void
164nft_masq_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
165{
166 nf_ct_netns_put(ctx->net, NFPROTO_IPV6);
167}
168
169static struct nft_expr_type nft_masq_ipv6_type;
170static const struct nft_expr_ops nft_masq_ipv6_ops = {
171 .type = &nft_masq_ipv6_type,
172 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
173 .eval = nft_masq_ipv6_eval,
174 .init = nft_masq_init,
175 .destroy = nft_masq_ipv6_destroy,
176 .dump = nft_masq_dump,
177 .validate = nft_masq_validate,
178};
179
180static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
181 .family = NFPROTO_IPV6,
182 .name = "masq",
183 .ops = &nft_masq_ipv6_ops,
184 .policy = nft_masq_policy,
185 .maxattr = NFTA_MASQ_MAX,
186 .owner = THIS_MODULE,
187};
188
189static int __init nft_masq_module_init_ipv6(void)
190{
191 return nft_register_expr(&nft_masq_ipv6_type);
192}
193
194static void nft_masq_module_exit_ipv6(void)
195{
196 nft_unregister_expr(&nft_masq_ipv6_type);
197}
198#else
199static inline int nft_masq_module_init_ipv6(void) { return 0; }
200static inline void nft_masq_module_exit_ipv6(void) {}
201#endif
202
203#ifdef CONFIG_NF_TABLES_INET
204static void nft_masq_inet_eval(const struct nft_expr *expr,
205 struct nft_regs *regs,
206 const struct nft_pktinfo *pkt)
207{
208 switch (nft_pf(pkt)) {
209 case NFPROTO_IPV4:
210 return nft_masq_ipv4_eval(expr, regs, pkt);
211 case NFPROTO_IPV6:
212 return nft_masq_ipv6_eval(expr, regs, pkt);
213 }
214
215 WARN_ON_ONCE(1);
216}
217
218static void
219nft_masq_inet_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
220{
221 nf_ct_netns_put(ctx->net, NFPROTO_INET);
222}
223
224static struct nft_expr_type nft_masq_inet_type;
225static const struct nft_expr_ops nft_masq_inet_ops = {
226 .type = &nft_masq_inet_type,
227 .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
228 .eval = nft_masq_inet_eval,
229 .init = nft_masq_init,
230 .destroy = nft_masq_inet_destroy,
231 .dump = nft_masq_dump,
232 .validate = nft_masq_validate,
233};
234
235static struct nft_expr_type nft_masq_inet_type __read_mostly = {
236 .family = NFPROTO_INET,
237 .name = "masq",
238 .ops = &nft_masq_inet_ops,
239 .policy = nft_masq_policy,
240 .maxattr = NFTA_MASQ_MAX,
241 .owner = THIS_MODULE,
242};
243
244static int __init nft_masq_module_init_inet(void)
245{
246 return nft_register_expr(&nft_masq_inet_type);
247}
248
249static void nft_masq_module_exit_inet(void)
250{
251 nft_unregister_expr(&nft_masq_inet_type);
252}
253#else
254static inline int nft_masq_module_init_inet(void) { return 0; }
255static inline void nft_masq_module_exit_inet(void) {}
256#endif
257
258static int __init nft_masq_module_init(void)
259{
260 int ret;
261
262 ret = nft_masq_module_init_ipv6();
263 if (ret < 0)
264 return ret;
265
266 ret = nft_masq_module_init_inet();
267 if (ret < 0) {
268 nft_masq_module_exit_ipv6();
269 return ret;
270 }
271
272 ret = nft_register_expr(&nft_masq_ipv4_type);
273 if (ret < 0) {
274 nft_masq_module_exit_inet();
275 nft_masq_module_exit_ipv6();
276 return ret;
277 }
278
279 ret = nf_nat_masquerade_inet_register_notifiers();
280 if (ret < 0) {
281 nft_masq_module_exit_ipv6();
282 nft_masq_module_exit_inet();
283 nft_unregister_expr(&nft_masq_ipv4_type);
284 return ret;
285 }
286
287 return ret;
288}
289
290static void __exit nft_masq_module_exit(void)
291{
292 nft_masq_module_exit_ipv6();
293 nft_masq_module_exit_inet();
294 nft_unregister_expr(&nft_masq_ipv4_type);
295 nf_nat_masquerade_inet_unregister_notifiers();
296}
297
298module_init(nft_masq_module_init);
299module_exit(nft_masq_module_exit);
300
301MODULE_LICENSE("GPL");
302MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
303MODULE_ALIAS_NFT_EXPR("masq");
304MODULE_DESCRIPTION("Netfilter nftables masquerade expression support");