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 const struct nft_expr_ops nft_fwd_netdev_ingress_ops;
58 static int nft_fwd_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
60 struct nft_fwd_netdev *priv = nft_expr_priv(expr);
62 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev))
71 struct nft_fwd_neigh {
72 enum nft_registers sreg_dev:8;
73 enum nft_registers sreg_addr:8;
77 static void nft_fwd_neigh_eval(const struct nft_expr *expr,
78 struct nft_regs *regs,
79 const struct nft_pktinfo *pkt)
81 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
82 void *addr = ®s->data[priv->sreg_addr];
83 int oif = regs->data[priv->sreg_dev];
84 unsigned int verdict = NF_STOLEN;
85 struct sk_buff *skb = pkt->skb;
86 struct net_device *dev;
89 switch (priv->nfproto) {
93 if (skb->protocol != htons(ETH_P_IP)) {
97 if (skb_try_make_writable(skb, sizeof(*iph))) {
102 ip_decrease_ttl(iph);
103 neigh_table = NEIGH_ARP_TABLE;
107 struct ipv6hdr *ip6h;
109 if (skb->protocol != htons(ETH_P_IPV6)) {
113 if (skb_try_make_writable(skb, sizeof(*ip6h))) {
117 ip6h = ipv6_hdr(skb);
119 neigh_table = NEIGH_ND_TABLE;
127 dev = dev_get_by_index_rcu(nft_net(pkt), oif);
132 neigh_xmit(neigh_table, dev, addr, skb);
134 regs->verdict.code = verdict;
137 static int nft_fwd_neigh_init(const struct nft_ctx *ctx,
138 const struct nft_expr *expr,
139 const struct nlattr * const tb[])
141 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
142 unsigned int addr_len;
145 if (!tb[NFTA_FWD_SREG_DEV] ||
146 !tb[NFTA_FWD_SREG_ADDR] ||
147 !tb[NFTA_FWD_NFPROTO])
150 priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]);
151 priv->sreg_addr = nft_parse_register(tb[NFTA_FWD_SREG_ADDR]);
152 priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO]));
154 switch (priv->nfproto) {
156 addr_len = sizeof(struct in_addr);
159 addr_len = sizeof(struct in6_addr);
165 err = nft_validate_register_load(priv->sreg_dev, sizeof(int));
169 return nft_validate_register_load(priv->sreg_addr, addr_len);
172 static const struct nft_expr_ops nft_fwd_netdev_ingress_ops;
174 static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr)
176 struct nft_fwd_neigh *priv = nft_expr_priv(expr);
178 if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) ||
179 nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) ||
180 nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto)))
181 goto nla_put_failure;
189 static struct nft_expr_type nft_fwd_netdev_type;
190 static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
191 .type = &nft_fwd_netdev_type,
192 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)),
193 .eval = nft_fwd_neigh_eval,
194 .init = nft_fwd_neigh_init,
195 .dump = nft_fwd_neigh_dump,
198 static const struct nft_expr_ops nft_fwd_netdev_ops = {
199 .type = &nft_fwd_netdev_type,
200 .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)),
201 .eval = nft_fwd_netdev_eval,
202 .init = nft_fwd_netdev_init,
203 .dump = nft_fwd_netdev_dump,
206 static const struct nft_expr_ops *
207 nft_fwd_select_ops(const struct nft_ctx *ctx,
208 const struct nlattr * const tb[])
210 if (tb[NFTA_FWD_SREG_ADDR])
211 return &nft_fwd_neigh_netdev_ops;
212 if (tb[NFTA_FWD_SREG_DEV])
213 return &nft_fwd_netdev_ops;
215 return ERR_PTR(-EOPNOTSUPP);
218 static struct nft_expr_type nft_fwd_netdev_type __read_mostly = {
219 .family = NFPROTO_NETDEV,
221 .select_ops = nft_fwd_select_ops,
222 .policy = nft_fwd_netdev_policy,
223 .maxattr = NFTA_FWD_MAX,
224 .owner = THIS_MODULE,
227 static int __init nft_fwd_netdev_module_init(void)
229 return nft_register_expr(&nft_fwd_netdev_type);
232 static void __exit nft_fwd_netdev_module_exit(void)
234 nft_unregister_expr(&nft_fwd_netdev_type);
237 module_init(nft_fwd_netdev_module_init);
238 module_exit(nft_fwd_netdev_module_exit);
240 MODULE_LICENSE("GPL");
241 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
242 MODULE_ALIAS_NFT_AF_EXPR(5, "fwd");