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_dup_netdev.h>
16 #include <net/neighbour.h>
19 struct nft_fwd_netdev {
20 enum nft_registers sreg_dev:8;
23 static void nft_fwd_netdev_eval(const struct nft_expr *expr,
24 struct nft_regs *regs,
25 const struct nft_pktinfo *pkt)
27 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
28 int oif = regs->data[priv->sreg_dev];
30 nf_fwd_netdev_egress(pkt, oif);
31 regs->verdict.code = NF_STOLEN;
34 static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = {
35 [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 },
36 [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 },
37 [NFTA_FWD_NFPROTO] = { .type = NLA_U32 },
40 static int nft_fwd_netdev_init(const struct nft_ctx *ctx,
41 const struct nft_expr *expr,
42 const struct nlattr * const tb[])
44 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
46 if (tb[NFTA_FWD_SREG_DEV] == NULL)
49 priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]);
50 return nft_validate_register_load(priv->sreg_dev, sizeof(int));
53 static int nft_fwd_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
55 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
57 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev))
66 struct nft_fwd_neigh {
67 enum nft_registers sreg_dev:8;
68 enum nft_registers sreg_addr:8;
72 static void nft_fwd_neigh_eval(const struct nft_expr *expr,
73 struct nft_regs *regs,
74 const struct nft_pktinfo *pkt)
76 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
77 void *addr = ®s->data[priv->sreg_addr];
78 int oif = regs->data[priv->sreg_dev];
79 unsigned int verdict = NF_STOLEN;
80 struct sk_buff *skb = pkt->skb;
81 struct net_device *dev;
84 switch (priv->nfproto) {
88 if (skb->protocol != htons(ETH_P_IP)) {
92 if (skb_try_make_writable(skb, sizeof(*iph))) {
98 neigh_table = NEIGH_ARP_TABLE;
102 struct ipv6hdr *ip6h;
104 if (skb->protocol != htons(ETH_P_IPV6)) {
108 if (skb_try_make_writable(skb, sizeof(*ip6h))) {
112 ip6h = ipv6_hdr(skb);
114 neigh_table = NEIGH_ND_TABLE;
122 dev = dev_get_by_index_rcu(nft_net(pkt), oif);
127 neigh_xmit(neigh_table, dev, addr, skb);
129 regs->verdict.code = verdict;
132 static int nft_fwd_neigh_init(const struct nft_ctx *ctx,
133 const struct nft_expr *expr,
134 const struct nlattr * const tb[])
136 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
137 unsigned int addr_len;
140 if (!tb[NFTA_FWD_SREG_DEV] ||
141 !tb[NFTA_FWD_SREG_ADDR] ||
142 !tb[NFTA_FWD_NFPROTO])
145 priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]);
146 priv->sreg_addr = nft_parse_register(tb[NFTA_FWD_SREG_ADDR]);
147 priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO]));
149 switch (priv->nfproto) {
151 addr_len = sizeof(struct in_addr);
154 addr_len = sizeof(struct in6_addr);
160 err = nft_validate_register_load(priv->sreg_dev, sizeof(int));
164 return nft_validate_register_load(priv->sreg_addr, addr_len);
167 static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr)
169 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
171 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) ||
172 nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) ||
173 nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto)))
174 goto nla_put_failure;
182 static struct nft_expr_type nft_fwd_netdev_type;
183 static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
184 .type = &nft_fwd_netdev_type,
185 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)),
186 .eval = nft_fwd_neigh_eval,
187 .init = nft_fwd_neigh_init,
188 .dump = nft_fwd_neigh_dump,
191 static const struct nft_expr_ops nft_fwd_netdev_ops = {
192 .type = &nft_fwd_netdev_type,
193 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)),
194 .eval = nft_fwd_netdev_eval,
195 .init = nft_fwd_netdev_init,
196 .dump = nft_fwd_netdev_dump,
199 static const struct nft_expr_ops *
200 nft_fwd_select_ops(const struct nft_ctx *ctx,
201 const struct nlattr * const tb[])
203 if (tb[NFTA_FWD_SREG_ADDR])
204 return &nft_fwd_neigh_netdev_ops;
205 if (tb[NFTA_FWD_SREG_DEV])
206 return &nft_fwd_netdev_ops;
208 return ERR_PTR(-EOPNOTSUPP);
211 static struct nft_expr_type nft_fwd_netdev_type __read_mostly = {
212 .family = NFPROTO_NETDEV,
214 .select_ops = nft_fwd_select_ops,
215 .policy = nft_fwd_netdev_policy,
216 .maxattr = NFTA_FWD_MAX,
217 .owner = THIS_MODULE,
220 static int __init nft_fwd_netdev_module_init(void)
222 return nft_register_expr(&nft_fwd_netdev_type);
225 static void __exit nft_fwd_netdev_module_exit(void)
227 nft_unregister_expr(&nft_fwd_netdev_type);
230 module_init(nft_fwd_netdev_module_init);
231 module_exit(nft_fwd_netdev_module_exit);
233 MODULE_LICENSE("GPL");
234 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
235 MODULE_ALIAS_NFT_AF_EXPR(5, "fwd");