1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
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>
13 #include <linux/ipv6.h>
14 #include <net/netfilter/nf_tables.h>
15 #include <net/netfilter/nf_tables_offload.h>
16 #include <net/netfilter/nf_dup_netdev.h>
17 #include <net/neighbour.h>
20 struct nft_fwd_netdev {
24 static void nft_fwd_netdev_eval(const struct nft_expr *expr,
25 struct nft_regs *regs,
26 const struct nft_pktinfo *pkt)
28 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
29 int oif = regs->data[priv->sreg_dev];
30 struct sk_buff *skb = pkt->skb;
32 /* This is used by ifb only. */
33 skb->skb_iif = skb->dev->ifindex;
34 skb_set_redirected(skb, nft_hook(pkt) == NF_NETDEV_INGRESS);
36 nf_fwd_netdev_egress(pkt, oif);
37 regs->verdict.code = NF_STOLEN;
40 static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = {
41 [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 },
42 [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 },
43 [NFTA_FWD_NFPROTO] = { .type = NLA_U32 },
46 static int nft_fwd_netdev_init(const struct nft_ctx *ctx,
47 const struct nft_expr *expr,
48 const struct nlattr * const tb[])
50 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
52 if (tb[NFTA_FWD_SREG_DEV] == NULL)
55 return nft_parse_register_load(tb[NFTA_FWD_SREG_DEV], &priv->sreg_dev,
59 static int nft_fwd_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
61 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
63 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev))
72 static int nft_fwd_netdev_offload(struct nft_offload_ctx *ctx,
73 struct nft_flow_rule *flow,
74 const struct nft_expr *expr)
76 const struct nft_fwd_netdev *priv = nft_expr_priv(expr);
77 int oif = ctx->regs[priv->sreg_dev].data.data[0];
79 return nft_fwd_dup_netdev_offload(ctx, flow, FLOW_ACTION_REDIRECT, oif);
82 static bool nft_fwd_netdev_offload_action(const struct nft_expr *expr)
87 struct nft_fwd_neigh {
93 static void nft_fwd_neigh_eval(const struct nft_expr *expr,
94 struct nft_regs *regs,
95 const struct nft_pktinfo *pkt)
97 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
98 void *addr = ®s->data[priv->sreg_addr];
99 int oif = regs->data[priv->sreg_dev];
100 unsigned int verdict = NF_STOLEN;
101 struct sk_buff *skb = pkt->skb;
102 struct net_device *dev;
105 switch (priv->nfproto) {
109 if (skb->protocol != htons(ETH_P_IP)) {
113 if (skb_try_make_writable(skb, sizeof(*iph))) {
118 ip_decrease_ttl(iph);
119 neigh_table = NEIGH_ARP_TABLE;
123 struct ipv6hdr *ip6h;
125 if (skb->protocol != htons(ETH_P_IPV6)) {
129 if (skb_try_make_writable(skb, sizeof(*ip6h))) {
133 ip6h = ipv6_hdr(skb);
135 neigh_table = NEIGH_ND_TABLE;
143 dev = dev_get_by_index_rcu(nft_net(pkt), oif);
148 skb_clear_tstamp(skb);
149 neigh_xmit(neigh_table, dev, addr, skb);
151 regs->verdict.code = verdict;
154 static int nft_fwd_neigh_init(const struct nft_ctx *ctx,
155 const struct nft_expr *expr,
156 const struct nlattr * const tb[])
158 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
159 unsigned int addr_len;
162 if (!tb[NFTA_FWD_SREG_DEV] ||
163 !tb[NFTA_FWD_SREG_ADDR] ||
164 !tb[NFTA_FWD_NFPROTO])
167 priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO]));
169 switch (priv->nfproto) {
171 addr_len = sizeof(struct in_addr);
174 addr_len = sizeof(struct in6_addr);
180 err = nft_parse_register_load(tb[NFTA_FWD_SREG_DEV], &priv->sreg_dev,
185 return nft_parse_register_load(tb[NFTA_FWD_SREG_ADDR], &priv->sreg_addr,
189 static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr)
191 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
193 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) ||
194 nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) ||
195 nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto)))
196 goto nla_put_failure;
204 static int nft_fwd_validate(const struct nft_ctx *ctx,
205 const struct nft_expr *expr,
206 const struct nft_data **data)
208 return nft_chain_validate_hooks(ctx->chain, (1 << NF_NETDEV_INGRESS) |
209 (1 << NF_NETDEV_EGRESS));
212 static struct nft_expr_type nft_fwd_netdev_type;
213 static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
214 .type = &nft_fwd_netdev_type,
215 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)),
216 .eval = nft_fwd_neigh_eval,
217 .init = nft_fwd_neigh_init,
218 .dump = nft_fwd_neigh_dump,
219 .validate = nft_fwd_validate,
220 .reduce = NFT_REDUCE_READONLY,
223 static const struct nft_expr_ops nft_fwd_netdev_ops = {
224 .type = &nft_fwd_netdev_type,
225 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)),
226 .eval = nft_fwd_netdev_eval,
227 .init = nft_fwd_netdev_init,
228 .dump = nft_fwd_netdev_dump,
229 .validate = nft_fwd_validate,
230 .reduce = NFT_REDUCE_READONLY,
231 .offload = nft_fwd_netdev_offload,
232 .offload_action = nft_fwd_netdev_offload_action,
235 static const struct nft_expr_ops *
236 nft_fwd_select_ops(const struct nft_ctx *ctx,
237 const struct nlattr * const tb[])
239 if (tb[NFTA_FWD_SREG_ADDR])
240 return &nft_fwd_neigh_netdev_ops;
241 if (tb[NFTA_FWD_SREG_DEV])
242 return &nft_fwd_netdev_ops;
244 return ERR_PTR(-EOPNOTSUPP);
247 static struct nft_expr_type nft_fwd_netdev_type __read_mostly = {
248 .family = NFPROTO_NETDEV,
250 .select_ops = nft_fwd_select_ops,
251 .policy = nft_fwd_netdev_policy,
252 .maxattr = NFTA_FWD_MAX,
253 .owner = THIS_MODULE,
256 static int __init nft_fwd_netdev_module_init(void)
258 return nft_register_expr(&nft_fwd_netdev_type);
261 static void __exit nft_fwd_netdev_module_exit(void)
263 nft_unregister_expr(&nft_fwd_netdev_type);
266 module_init(nft_fwd_netdev_module_init);
267 module_exit(nft_fwd_netdev_module_exit);
269 MODULE_LICENSE("GPL");
270 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
271 MODULE_ALIAS_NFT_AF_EXPR(5, "fwd");