1 // SPDX-License-Identifier: GPL-2.0-only
4 * Generic part shared by ipv4 and ipv6 backends.
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>
18 static 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 },
26 enum nft_xfrm_keys key:8;
27 enum nft_registers dreg:8;
32 static int nft_xfrm_get_init(const struct nft_ctx *ctx,
33 const struct nft_expr *expr,
34 const struct nlattr * const tb[])
36 struct nft_xfrm *priv = nft_expr_priv(expr);
41 if (!tb[NFTA_XFRM_KEY] || !tb[NFTA_XFRM_DIR] || !tb[NFTA_XFRM_DREG])
44 switch (ctx->family) {
53 priv->key = ntohl(nla_get_u32(tb[NFTA_XFRM_KEY]));
55 case NFT_XFRM_KEY_REQID:
56 case NFT_XFRM_KEY_SPI:
59 case NFT_XFRM_KEY_DADDR_IP4:
60 case NFT_XFRM_KEY_SADDR_IP4:
61 len = sizeof(struct in_addr);
63 case NFT_XFRM_KEY_DADDR_IP6:
64 case NFT_XFRM_KEY_SADDR_IP6:
65 len = sizeof(struct in6_addr);
71 dir = nla_get_u8(tb[NFTA_XFRM_DIR]);
81 if (tb[NFTA_XFRM_SPNUM])
82 spnum = ntohl(nla_get_be32(tb[NFTA_XFRM_SPNUM]));
84 if (spnum >= XFRM_MAX_DEPTH)
89 priv->dreg = nft_parse_register(tb[NFTA_XFRM_DREG]);
90 return nft_validate_register_store(ctx, priv->dreg, NULL,
94 /* Return true if key asks for daddr/saddr and current
95 * state does have a valid address (BEET, TUNNEL).
97 static bool xfrm_state_addr_ok(enum nft_xfrm_keys k, u8 family, u8 mode)
100 case NFT_XFRM_KEY_DADDR_IP4:
101 case NFT_XFRM_KEY_SADDR_IP4:
102 if (family == NFPROTO_IPV4)
105 case NFT_XFRM_KEY_DADDR_IP6:
106 case NFT_XFRM_KEY_SADDR_IP6:
107 if (family == NFPROTO_IPV6)
114 return mode == XFRM_MODE_BEET || mode == XFRM_MODE_TUNNEL;
117 static void nft_xfrm_state_get_key(const struct nft_xfrm *priv,
118 struct nft_regs *regs,
119 const struct xfrm_state *state)
121 u32 *dest = ®s->data[priv->dreg];
123 if (!xfrm_state_addr_ok(priv->key,
125 state->props.mode)) {
126 regs->verdict.code = NFT_BREAK;
131 case NFT_XFRM_KEY_UNSPEC:
132 case __NFT_XFRM_KEY_MAX:
135 case NFT_XFRM_KEY_DADDR_IP4:
136 *dest = state->id.daddr.a4;
138 case NFT_XFRM_KEY_DADDR_IP6:
139 memcpy(dest, &state->id.daddr.in6, sizeof(struct in6_addr));
141 case NFT_XFRM_KEY_SADDR_IP4:
142 *dest = state->props.saddr.a4;
144 case NFT_XFRM_KEY_SADDR_IP6:
145 memcpy(dest, &state->props.saddr.in6, sizeof(struct in6_addr));
147 case NFT_XFRM_KEY_REQID:
148 *dest = state->props.reqid;
150 case NFT_XFRM_KEY_SPI:
151 *dest = state->id.spi;
155 regs->verdict.code = NFT_BREAK;
158 static void nft_xfrm_get_eval_in(const struct nft_xfrm *priv,
159 struct nft_regs *regs,
160 const struct nft_pktinfo *pkt)
162 const struct sec_path *sp = skb_sec_path(pkt->skb);
163 const struct xfrm_state *state;
165 if (sp == NULL || sp->len <= priv->spnum) {
166 regs->verdict.code = NFT_BREAK;
170 state = sp->xvec[priv->spnum];
171 nft_xfrm_state_get_key(priv, regs, state);
174 static void nft_xfrm_get_eval_out(const struct nft_xfrm *priv,
175 struct nft_regs *regs,
176 const struct nft_pktinfo *pkt)
178 const struct dst_entry *dst = skb_dst(pkt->skb);
181 for (i = 0; dst && dst->xfrm;
182 dst = ((const struct xfrm_dst *)dst)->child, i++) {
186 nft_xfrm_state_get_key(priv, regs, dst->xfrm);
190 regs->verdict.code = NFT_BREAK;
193 static void nft_xfrm_get_eval(const struct nft_expr *expr,
194 struct nft_regs *regs,
195 const struct nft_pktinfo *pkt)
197 const struct nft_xfrm *priv = nft_expr_priv(expr);
201 nft_xfrm_get_eval_in(priv, regs, pkt);
203 case XFRM_POLICY_OUT:
204 nft_xfrm_get_eval_out(priv, regs, pkt);
208 regs->verdict.code = NFT_BREAK;
213 static int nft_xfrm_get_dump(struct sk_buff *skb,
214 const struct nft_expr *expr)
216 const struct nft_xfrm *priv = nft_expr_priv(expr);
218 if (nft_dump_register(skb, NFTA_XFRM_DREG, priv->dreg))
221 if (nla_put_be32(skb, NFTA_XFRM_KEY, htonl(priv->key)))
223 if (nla_put_u8(skb, NFTA_XFRM_DIR, priv->dir))
225 if (nla_put_be32(skb, NFTA_XFRM_SPNUM, htonl(priv->spnum)))
231 static int nft_xfrm_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
232 const struct nft_data **data)
234 const struct nft_xfrm *priv = nft_expr_priv(expr);
239 hooks = (1 << NF_INET_FORWARD) |
240 (1 << NF_INET_LOCAL_IN) |
241 (1 << NF_INET_PRE_ROUTING);
243 case XFRM_POLICY_OUT:
244 hooks = (1 << NF_INET_FORWARD) |
245 (1 << NF_INET_LOCAL_OUT) |
246 (1 << NF_INET_POST_ROUTING);
253 return nft_chain_validate_hooks(ctx->chain, hooks);
257 static struct nft_expr_type nft_xfrm_type;
258 static 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,
267 static struct nft_expr_type nft_xfrm_type __read_mostly = {
269 .ops = &nft_xfrm_get_ops,
270 .policy = nft_xfrm_policy,
271 .maxattr = NFTA_XFRM_MAX,
272 .owner = THIS_MODULE,
275 static int __init nft_xfrm_module_init(void)
277 return nft_register_expr(&nft_xfrm_type);
280 static void __exit nft_xfrm_module_exit(void)
282 nft_unregister_expr(&nft_xfrm_type);
285 module_init(nft_xfrm_module_init);
286 module_exit(nft_xfrm_module_exit);
288 MODULE_LICENSE("GPL");
289 MODULE_DESCRIPTION("nf_tables: xfrm/IPSec matching");
290 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
291 MODULE_AUTHOR("Máté Eckl <ecklm94@gmail.com>");
292 MODULE_ALIAS_NFT_EXPR("xfrm");