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] = NLA_POLICY_MAX(NLA_BE32, 255),
20 [NFTA_XFRM_DIR] = { .type = NLA_U8 },
21 [NFTA_XFRM_SPNUM] = NLA_POLICY_MAX(NLA_BE32, 255),
22 [NFTA_XFRM_DREG] = { .type = NLA_U32 },
26 enum nft_xfrm_keys key:8;
33 static int nft_xfrm_get_init(const struct nft_ctx *ctx,
34 const struct nft_expr *expr,
35 const struct nlattr * const tb[])
37 struct nft_xfrm *priv = nft_expr_priv(expr);
42 if (!tb[NFTA_XFRM_KEY] || !tb[NFTA_XFRM_DIR] || !tb[NFTA_XFRM_DREG])
45 switch (ctx->family) {
54 priv->key = ntohl(nla_get_be32(tb[NFTA_XFRM_KEY]));
56 case NFT_XFRM_KEY_REQID:
57 case NFT_XFRM_KEY_SPI:
60 case NFT_XFRM_KEY_DADDR_IP4:
61 case NFT_XFRM_KEY_SADDR_IP4:
62 len = sizeof(struct in_addr);
64 case NFT_XFRM_KEY_DADDR_IP6:
65 case NFT_XFRM_KEY_SADDR_IP6:
66 len = sizeof(struct in6_addr);
72 dir = nla_get_u8(tb[NFTA_XFRM_DIR]);
82 if (tb[NFTA_XFRM_SPNUM])
83 spnum = ntohl(nla_get_be32(tb[NFTA_XFRM_SPNUM]));
85 if (spnum >= XFRM_MAX_DEPTH)
91 return nft_parse_register_store(ctx, tb[NFTA_XFRM_DREG], &priv->dreg,
92 NULL, NFT_DATA_VALUE, len);
95 /* Return true if key asks for daddr/saddr and current
96 * state does have a valid address (BEET, TUNNEL).
98 static bool xfrm_state_addr_ok(enum nft_xfrm_keys k, u8 family, u8 mode)
101 case NFT_XFRM_KEY_DADDR_IP4:
102 case NFT_XFRM_KEY_SADDR_IP4:
103 if (family == NFPROTO_IPV4)
106 case NFT_XFRM_KEY_DADDR_IP6:
107 case NFT_XFRM_KEY_SADDR_IP6:
108 if (family == NFPROTO_IPV6)
115 return mode == XFRM_MODE_BEET || mode == XFRM_MODE_TUNNEL;
118 static void nft_xfrm_state_get_key(const struct nft_xfrm *priv,
119 struct nft_regs *regs,
120 const struct xfrm_state *state)
122 u32 *dest = ®s->data[priv->dreg];
124 if (!xfrm_state_addr_ok(priv->key,
126 state->props.mode)) {
127 regs->verdict.code = NFT_BREAK;
132 case NFT_XFRM_KEY_UNSPEC:
133 case __NFT_XFRM_KEY_MAX:
136 case NFT_XFRM_KEY_DADDR_IP4:
137 *dest = (__force __u32)state->id.daddr.a4;
139 case NFT_XFRM_KEY_DADDR_IP6:
140 memcpy(dest, &state->id.daddr.in6, sizeof(struct in6_addr));
142 case NFT_XFRM_KEY_SADDR_IP4:
143 *dest = (__force __u32)state->props.saddr.a4;
145 case NFT_XFRM_KEY_SADDR_IP6:
146 memcpy(dest, &state->props.saddr.in6, sizeof(struct in6_addr));
148 case NFT_XFRM_KEY_REQID:
149 *dest = state->props.reqid;
151 case NFT_XFRM_KEY_SPI:
152 *dest = (__force __u32)state->id.spi;
156 regs->verdict.code = NFT_BREAK;
159 static void nft_xfrm_get_eval_in(const struct nft_xfrm *priv,
160 struct nft_regs *regs,
161 const struct nft_pktinfo *pkt)
163 const struct sec_path *sp = skb_sec_path(pkt->skb);
164 const struct xfrm_state *state;
166 if (sp == NULL || sp->len <= priv->spnum) {
167 regs->verdict.code = NFT_BREAK;
171 state = sp->xvec[priv->spnum];
172 nft_xfrm_state_get_key(priv, regs, state);
175 static void nft_xfrm_get_eval_out(const struct nft_xfrm *priv,
176 struct nft_regs *regs,
177 const struct nft_pktinfo *pkt)
179 const struct dst_entry *dst = skb_dst(pkt->skb);
182 for (i = 0; dst && dst->xfrm;
183 dst = ((const struct xfrm_dst *)dst)->child, i++) {
187 nft_xfrm_state_get_key(priv, regs, dst->xfrm);
191 regs->verdict.code = NFT_BREAK;
194 static void nft_xfrm_get_eval(const struct nft_expr *expr,
195 struct nft_regs *regs,
196 const struct nft_pktinfo *pkt)
198 const struct nft_xfrm *priv = nft_expr_priv(expr);
202 nft_xfrm_get_eval_in(priv, regs, pkt);
204 case XFRM_POLICY_OUT:
205 nft_xfrm_get_eval_out(priv, regs, pkt);
209 regs->verdict.code = NFT_BREAK;
214 static int nft_xfrm_get_dump(struct sk_buff *skb,
215 const struct nft_expr *expr, bool reset)
217 const struct nft_xfrm *priv = nft_expr_priv(expr);
219 if (nft_dump_register(skb, NFTA_XFRM_DREG, priv->dreg))
222 if (nla_put_be32(skb, NFTA_XFRM_KEY, htonl(priv->key)))
224 if (nla_put_u8(skb, NFTA_XFRM_DIR, priv->dir))
226 if (nla_put_be32(skb, NFTA_XFRM_SPNUM, htonl(priv->spnum)))
232 static int nft_xfrm_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
233 const struct nft_data **data)
235 const struct nft_xfrm *priv = nft_expr_priv(expr);
238 if (ctx->family != NFPROTO_IPV4 &&
239 ctx->family != NFPROTO_IPV6 &&
240 ctx->family != NFPROTO_INET)
245 hooks = (1 << NF_INET_FORWARD) |
246 (1 << NF_INET_LOCAL_IN) |
247 (1 << NF_INET_PRE_ROUTING);
249 case XFRM_POLICY_OUT:
250 hooks = (1 << NF_INET_FORWARD) |
251 (1 << NF_INET_LOCAL_OUT) |
252 (1 << NF_INET_POST_ROUTING);
259 return nft_chain_validate_hooks(ctx->chain, hooks);
262 static bool nft_xfrm_reduce(struct nft_regs_track *track,
263 const struct nft_expr *expr)
265 const struct nft_xfrm *priv = nft_expr_priv(expr);
266 const struct nft_xfrm *xfrm;
268 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
269 nft_reg_track_update(track, expr, priv->dreg, priv->len);
273 xfrm = nft_expr_priv(track->regs[priv->dreg].selector);
274 if (priv->key != xfrm->key ||
275 priv->dreg != xfrm->dreg ||
276 priv->dir != xfrm->dir ||
277 priv->spnum != xfrm->spnum) {
278 nft_reg_track_update(track, expr, priv->dreg, priv->len);
282 if (!track->regs[priv->dreg].bitwise)
285 return nft_expr_reduce_bitwise(track, expr);
288 static struct nft_expr_type nft_xfrm_type;
289 static const struct nft_expr_ops nft_xfrm_get_ops = {
290 .type = &nft_xfrm_type,
291 .size = NFT_EXPR_SIZE(sizeof(struct nft_xfrm)),
292 .eval = nft_xfrm_get_eval,
293 .init = nft_xfrm_get_init,
294 .dump = nft_xfrm_get_dump,
295 .validate = nft_xfrm_validate,
296 .reduce = nft_xfrm_reduce,
299 static struct nft_expr_type nft_xfrm_type __read_mostly = {
301 .ops = &nft_xfrm_get_ops,
302 .policy = nft_xfrm_policy,
303 .maxattr = NFTA_XFRM_MAX,
304 .owner = THIS_MODULE,
307 static int __init nft_xfrm_module_init(void)
309 return nft_register_expr(&nft_xfrm_type);
312 static void __exit nft_xfrm_module_exit(void)
314 nft_unregister_expr(&nft_xfrm_type);
317 module_init(nft_xfrm_module_init);
318 module_exit(nft_xfrm_module_exit);
320 MODULE_LICENSE("GPL");
321 MODULE_DESCRIPTION("nf_tables: xfrm/IPSec matching");
322 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
323 MODULE_AUTHOR("Máté Eckl <ecklm94@gmail.com>");
324 MODULE_ALIAS_NFT_EXPR("xfrm");