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7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <linux/module.h>
10#include <linux/netlink.h>
11#include <linux/netfilter.h>
12#include <linux/netfilter/nf_tables.h>
13#include <net/netfilter/nf_tables_core.h>
14#include <net/netfilter/nf_tables.h>
15#include <linux/in.h>
16#include <net/xfrm.h>
17
18static const struct nla_policy nft_xfrm_policy[NFTA_XFRM_MAX + 1] = {
19 [NFTA_XFRM_KEY] = { .type = NLA_U32 },
20 [NFTA_XFRM_DIR] = { .type = NLA_U8 },
21 [NFTA_XFRM_SPNUM] = { .type = NLA_U32 },
22 [NFTA_XFRM_DREG] = { .type = NLA_U32 },
23};
24
25struct nft_xfrm {
26 enum nft_xfrm_keys key:8;
27 enum nft_registers dreg:8;
28 u8 dir;
29 u8 spnum;
30};
31
32static int nft_xfrm_get_init(const struct nft_ctx *ctx,
33 const struct nft_expr *expr,
34 const struct nlattr * const tb[])
35{
36 struct nft_xfrm *priv = nft_expr_priv(expr);
37 unsigned int len = 0;
38 u32 spnum = 0;
39 u8 dir;
40
41 if (!tb[NFTA_XFRM_KEY] || !tb[NFTA_XFRM_DIR] || !tb[NFTA_XFRM_DREG])
42 return -EINVAL;
43
44 switch (ctx->family) {
45 case NFPROTO_IPV4:
46 case NFPROTO_IPV6:
47 case NFPROTO_INET:
48 break;
49 default:
50 return -EOPNOTSUPP;
51 }
52
53 priv->key = ntohl(nla_get_u32(tb[NFTA_XFRM_KEY]));
54 switch (priv->key) {
55 case NFT_XFRM_KEY_REQID:
56 case NFT_XFRM_KEY_SPI:
57 len = sizeof(u32);
58 break;
59 case NFT_XFRM_KEY_DADDR_IP4:
60 case NFT_XFRM_KEY_SADDR_IP4:
61 len = sizeof(struct in_addr);
62 break;
63 case NFT_XFRM_KEY_DADDR_IP6:
64 case NFT_XFRM_KEY_SADDR_IP6:
65 len = sizeof(struct in6_addr);
66 break;
67 default:
68 return -EINVAL;
69 }
70
71 dir = nla_get_u8(tb[NFTA_XFRM_DIR]);
72 switch (dir) {
73 case XFRM_POLICY_IN:
74 case XFRM_POLICY_OUT:
75 priv->dir = dir;
76 break;
77 default:
78 return -EINVAL;
79 }
80
81 if (tb[NFTA_XFRM_SPNUM])
82 spnum = ntohl(nla_get_be32(tb[NFTA_XFRM_SPNUM]));
83
84 if (spnum >= XFRM_MAX_DEPTH)
85 return -ERANGE;
86
87 priv->spnum = spnum;
88
89 priv->dreg = nft_parse_register(tb[NFTA_XFRM_DREG]);
90 return nft_validate_register_store(ctx, priv->dreg, NULL,
91 NFT_DATA_VALUE, len);
92}
93
94
95
96
97static bool xfrm_state_addr_ok(enum nft_xfrm_keys k, u8 family, u8 mode)
98{
99 switch (k) {
100 case NFT_XFRM_KEY_DADDR_IP4:
101 case NFT_XFRM_KEY_SADDR_IP4:
102 if (family == NFPROTO_IPV4)
103 break;
104 return false;
105 case NFT_XFRM_KEY_DADDR_IP6:
106 case NFT_XFRM_KEY_SADDR_IP6:
107 if (family == NFPROTO_IPV6)
108 break;
109 return false;
110 default:
111 return true;
112 }
113
114 return mode == XFRM_MODE_BEET || mode == XFRM_MODE_TUNNEL;
115}
116
117static void nft_xfrm_state_get_key(const struct nft_xfrm *priv,
118 struct nft_regs *regs,
119 const struct xfrm_state *state)
120{
121 u32 *dest = ®s->data[priv->dreg];
122
123 if (!xfrm_state_addr_ok(priv->key,
124 state->props.family,
125 state->props.mode)) {
126 regs->verdict.code = NFT_BREAK;
127 return;
128 }
129
130 switch (priv->key) {
131 case NFT_XFRM_KEY_UNSPEC:
132 case __NFT_XFRM_KEY_MAX:
133 WARN_ON_ONCE(1);
134 break;
135 case NFT_XFRM_KEY_DADDR_IP4:
136 *dest = state->id.daddr.a4;
137 return;
138 case NFT_XFRM_KEY_DADDR_IP6:
139 memcpy(dest, &state->id.daddr.in6, sizeof(struct in6_addr));
140 return;
141 case NFT_XFRM_KEY_SADDR_IP4:
142 *dest = state->props.saddr.a4;
143 return;
144 case NFT_XFRM_KEY_SADDR_IP6:
145 memcpy(dest, &state->props.saddr.in6, sizeof(struct in6_addr));
146 return;
147 case NFT_XFRM_KEY_REQID:
148 *dest = state->props.reqid;
149 return;
150 case NFT_XFRM_KEY_SPI:
151 *dest = state->id.spi;
152 return;
153 }
154
155 regs->verdict.code = NFT_BREAK;
156}
157
158static void nft_xfrm_get_eval_in(const struct nft_xfrm *priv,
159 struct nft_regs *regs,
160 const struct nft_pktinfo *pkt)
161{
162 const struct sec_path *sp = skb_sec_path(pkt->skb);
163 const struct xfrm_state *state;
164
165 if (sp == NULL || sp->len <= priv->spnum) {
166 regs->verdict.code = NFT_BREAK;
167 return;
168 }
169
170 state = sp->xvec[priv->spnum];
171 nft_xfrm_state_get_key(priv, regs, state);
172}
173
174static void nft_xfrm_get_eval_out(const struct nft_xfrm *priv,
175 struct nft_regs *regs,
176 const struct nft_pktinfo *pkt)
177{
178 const struct dst_entry *dst = skb_dst(pkt->skb);
179 int i;
180
181 for (i = 0; dst && dst->xfrm;
182 dst = ((const struct xfrm_dst *)dst)->child, i++) {
183 if (i < priv->spnum)
184 continue;
185
186 nft_xfrm_state_get_key(priv, regs, dst->xfrm);
187 return;
188 }
189
190 regs->verdict.code = NFT_BREAK;
191}
192
193static void nft_xfrm_get_eval(const struct nft_expr *expr,
194 struct nft_regs *regs,
195 const struct nft_pktinfo *pkt)
196{
197 const struct nft_xfrm *priv = nft_expr_priv(expr);
198
199 switch (priv->dir) {
200 case XFRM_POLICY_IN:
201 nft_xfrm_get_eval_in(priv, regs, pkt);
202 break;
203 case XFRM_POLICY_OUT:
204 nft_xfrm_get_eval_out(priv, regs, pkt);
205 break;
206 default:
207 WARN_ON_ONCE(1);
208 regs->verdict.code = NFT_BREAK;
209 break;
210 }
211}
212
213static int nft_xfrm_get_dump(struct sk_buff *skb,
214 const struct nft_expr *expr)
215{
216 const struct nft_xfrm *priv = nft_expr_priv(expr);
217
218 if (nft_dump_register(skb, NFTA_XFRM_DREG, priv->dreg))
219 return -1;
220
221 if (nla_put_be32(skb, NFTA_XFRM_KEY, htonl(priv->key)))
222 return -1;
223 if (nla_put_u8(skb, NFTA_XFRM_DIR, priv->dir))
224 return -1;
225 if (nla_put_be32(skb, NFTA_XFRM_SPNUM, htonl(priv->spnum)))
226 return -1;
227
228 return 0;
229}
230
231static int nft_xfrm_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
232 const struct nft_data **data)
233{
234 const struct nft_xfrm *priv = nft_expr_priv(expr);
235 unsigned int hooks;
236
237 switch (priv->dir) {
238 case XFRM_POLICY_IN:
239 hooks = (1 << NF_INET_FORWARD) |
240 (1 << NF_INET_LOCAL_IN) |
241 (1 << NF_INET_PRE_ROUTING);
242 break;
243 case XFRM_POLICY_OUT:
244 hooks = (1 << NF_INET_FORWARD) |
245 (1 << NF_INET_LOCAL_OUT) |
246 (1 << NF_INET_POST_ROUTING);
247 break;
248 default:
249 WARN_ON_ONCE(1);
250 return -EINVAL;
251 }
252
253 return nft_chain_validate_hooks(ctx->chain, hooks);
254}
255
256
257static struct nft_expr_type nft_xfrm_type;
258static const struct nft_expr_ops nft_xfrm_get_ops = {
259 .type = &nft_xfrm_type,
260 .size = NFT_EXPR_SIZE(sizeof(struct nft_xfrm)),
261 .eval = nft_xfrm_get_eval,
262 .init = nft_xfrm_get_init,
263 .dump = nft_xfrm_get_dump,
264 .validate = nft_xfrm_validate,
265};
266
267static struct nft_expr_type nft_xfrm_type __read_mostly = {
268 .name = "xfrm",
269 .ops = &nft_xfrm_get_ops,
270 .policy = nft_xfrm_policy,
271 .maxattr = NFTA_XFRM_MAX,
272 .owner = THIS_MODULE,
273};
274
275static int __init nft_xfrm_module_init(void)
276{
277 return nft_register_expr(&nft_xfrm_type);
278}
279
280static void __exit nft_xfrm_module_exit(void)
281{
282 nft_unregister_expr(&nft_xfrm_type);
283}
284
285module_init(nft_xfrm_module_init);
286module_exit(nft_xfrm_module_exit);
287
288MODULE_LICENSE("GPL");
289MODULE_DESCRIPTION("nf_tables: xfrm/IPSec matching");
290MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
291MODULE_AUTHOR("Máté Eckl <ecklm94@gmail.com>");
292MODULE_ALIAS_NFT_EXPR("xfrm");
293
