2 * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published by
6 * the Free Software Foundation.
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/netlink.h>
13 #include <linux/netfilter.h>
14 #include <linux/netfilter/nf_tables.h>
16 #include <linux/ipv6.h>
17 #include <net/netfilter/nf_tables.h>
18 #include <net/netfilter/nf_dup_netdev.h>
19 #include <net/neighbour.h>
22 struct nft_fwd_netdev {
23 enum nft_registers sreg_dev:8;
26 static void nft_fwd_netdev_eval(const struct nft_expr *expr,
27 struct nft_regs *regs,
28 const struct nft_pktinfo *pkt)
30 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
31 int oif = regs->data[priv->sreg_dev];
33 nf_fwd_netdev_egress(pkt, oif);
34 regs->verdict.code = NF_STOLEN;
37 static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = {
38 [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 },
39 [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 },
40 [NFTA_FWD_NFPROTO] = { .type = NLA_U32 },
43 static int nft_fwd_netdev_init(const struct nft_ctx *ctx,
44 const struct nft_expr *expr,
45 const struct nlattr * const tb[])
47 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
49 if (tb[NFTA_FWD_SREG_DEV] == NULL)
52 priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]);
53 return nft_validate_register_load(priv->sreg_dev, sizeof(int));
56 static int nft_fwd_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
58 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
60 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev))
69 struct nft_fwd_neigh {
70 enum nft_registers sreg_dev:8;
71 enum nft_registers sreg_addr:8;
75 static void nft_fwd_neigh_eval(const struct nft_expr *expr,
76 struct nft_regs *regs,
77 const struct nft_pktinfo *pkt)
79 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
80 void *addr = ®s->data[priv->sreg_addr];
81 int oif = regs->data[priv->sreg_dev];
82 unsigned int verdict = NF_STOLEN;
83 struct sk_buff *skb = pkt->skb;
84 struct net_device *dev;
87 switch (priv->nfproto) {
91 if (skb->protocol != htons(ETH_P_IP)) {
95 if (skb_try_make_writable(skb, sizeof(*iph))) {
100 ip_decrease_ttl(iph);
101 neigh_table = NEIGH_ARP_TABLE;
105 struct ipv6hdr *ip6h;
107 if (skb->protocol != htons(ETH_P_IPV6)) {
111 if (skb_try_make_writable(skb, sizeof(*ip6h))) {
115 ip6h = ipv6_hdr(skb);
117 neigh_table = NEIGH_ND_TABLE;
125 dev = dev_get_by_index_rcu(nft_net(pkt), oif);
130 neigh_xmit(neigh_table, dev, addr, skb);
132 regs->verdict.code = verdict;
135 static int nft_fwd_neigh_init(const struct nft_ctx *ctx,
136 const struct nft_expr *expr,
137 const struct nlattr * const tb[])
139 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
140 unsigned int addr_len;
143 if (!tb[NFTA_FWD_SREG_DEV] ||
144 !tb[NFTA_FWD_SREG_ADDR] ||
145 !tb[NFTA_FWD_NFPROTO])
148 priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]);
149 priv->sreg_addr = nft_parse_register(tb[NFTA_FWD_SREG_ADDR]);
150 priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO]));
152 switch (priv->nfproto) {
154 addr_len = sizeof(struct in_addr);
157 addr_len = sizeof(struct in6_addr);
163 err = nft_validate_register_load(priv->sreg_dev, sizeof(int));
167 return nft_validate_register_load(priv->sreg_addr, addr_len);
170 static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr)
172 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
174 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) ||
175 nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) ||
176 nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto)))
177 goto nla_put_failure;
185 static struct nft_expr_type nft_fwd_netdev_type;
186 static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
187 .type = &nft_fwd_netdev_type,
188 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)),
189 .eval = nft_fwd_neigh_eval,
190 .init = nft_fwd_neigh_init,
191 .dump = nft_fwd_neigh_dump,
194 static const struct nft_expr_ops nft_fwd_netdev_ops = {
195 .type = &nft_fwd_netdev_type,
196 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)),
197 .eval = nft_fwd_netdev_eval,
198 .init = nft_fwd_netdev_init,
199 .dump = nft_fwd_netdev_dump,
202 static const struct nft_expr_ops *
203 nft_fwd_select_ops(const struct nft_ctx *ctx,
204 const struct nlattr * const tb[])
206 if (tb[NFTA_FWD_SREG_ADDR])
207 return &nft_fwd_neigh_netdev_ops;
208 if (tb[NFTA_FWD_SREG_DEV])
209 return &nft_fwd_netdev_ops;
211 return ERR_PTR(-EOPNOTSUPP);
214 static struct nft_expr_type nft_fwd_netdev_type __read_mostly = {
215 .family = NFPROTO_NETDEV,
217 .select_ops = nft_fwd_select_ops,
218 .policy = nft_fwd_netdev_policy,
219 .maxattr = NFTA_FWD_MAX,
220 .owner = THIS_MODULE,
223 static int __init nft_fwd_netdev_module_init(void)
225 return nft_register_expr(&nft_fwd_netdev_type);
228 static void __exit nft_fwd_netdev_module_exit(void)
230 nft_unregister_expr(&nft_fwd_netdev_type);
233 module_init(nft_fwd_netdev_module_init);
234 module_exit(nft_fwd_netdev_module_exit);
236 MODULE_LICENSE("GPL");
237 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
238 MODULE_ALIAS_NFT_AF_EXPR(5, "fwd");