2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
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>
15 #include <net/netfilter/nft_fib.h>
17 #include <net/ip_fib.h>
18 #include <net/route.h>
20 /* don't try to find route from mcast/bcast/zeronet */
21 static __be32 get_saddr(__be32 addr)
23 if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr) ||
24 ipv4_is_zeronet(addr))
29 #define DSCP_BITS 0xfc
31 void nft_fib4_eval_type(const struct nft_expr *expr, struct nft_regs *regs,
32 const struct nft_pktinfo *pkt)
34 const struct nft_fib *priv = nft_expr_priv(expr);
35 int noff = skb_network_offset(pkt->skb);
36 u32 *dst = ®s->data[priv->dreg];
37 const struct net_device *dev = NULL;
38 struct iphdr *iph, _iph;
41 if (priv->flags & NFTA_FIB_F_IIF)
43 else if (priv->flags & NFTA_FIB_F_OIF)
46 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
48 regs->verdict.code = NFT_BREAK;
52 if (priv->flags & NFTA_FIB_F_DADDR)
57 *dst = inet_dev_addr_type(nft_net(pkt), dev, addr);
59 EXPORT_SYMBOL_GPL(nft_fib4_eval_type);
61 void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs,
62 const struct nft_pktinfo *pkt)
64 const struct nft_fib *priv = nft_expr_priv(expr);
65 int noff = skb_network_offset(pkt->skb);
66 u32 *dest = ®s->data[priv->dreg];
67 struct iphdr *iph, _iph;
68 struct fib_result res;
70 .flowi4_scope = RT_SCOPE_UNIVERSE,
71 .flowi4_iif = LOOPBACK_IFINDEX,
73 const struct net_device *oif;
74 const struct net_device *found;
77 * Do not set flowi4_oif, it restricts results (for example, asking
78 * for oif 3 will get RTN_UNICAST result even if the daddr exits
79 * on another interface.
81 * Search results for the desired outinterface instead.
83 if (priv->flags & NFTA_FIB_F_OIF)
85 else if (priv->flags & NFTA_FIB_F_IIF)
90 if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
91 nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
92 nft_fib_store_result(dest, priv, nft_in(pkt));
96 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
98 regs->verdict.code = NFT_BREAK;
102 if (ipv4_is_zeronet(iph->saddr)) {
103 if (ipv4_is_lbcast(iph->daddr) ||
104 ipv4_is_local_multicast(iph->daddr)) {
105 nft_fib_store_result(dest, priv, pkt->skb->dev);
110 if (priv->flags & NFTA_FIB_F_MARK)
111 fl4.flowi4_mark = pkt->skb->mark;
113 fl4.flowi4_tos = iph->tos & DSCP_BITS;
115 if (priv->flags & NFTA_FIB_F_DADDR) {
116 fl4.daddr = iph->daddr;
117 fl4.saddr = get_saddr(iph->saddr);
119 fl4.daddr = iph->saddr;
120 fl4.saddr = get_saddr(iph->daddr);
125 if (fib_lookup(nft_net(pkt), &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE))
131 case RTN_LOCAL: /* Should not see RTN_LOCAL here */
138 found = FIB_RES_DEV(res);
140 if (!fib_info_nh_uses_dev(res.fi, oif))
146 nft_fib_store_result(dest, priv, found);
148 EXPORT_SYMBOL_GPL(nft_fib4_eval);
150 static struct nft_expr_type nft_fib4_type;
152 static const struct nft_expr_ops nft_fib4_type_ops = {
153 .type = &nft_fib4_type,
154 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
155 .eval = nft_fib4_eval_type,
156 .init = nft_fib_init,
157 .dump = nft_fib_dump,
158 .validate = nft_fib_validate,
161 static const struct nft_expr_ops nft_fib4_ops = {
162 .type = &nft_fib4_type,
163 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
164 .eval = nft_fib4_eval,
165 .init = nft_fib_init,
166 .dump = nft_fib_dump,
167 .validate = nft_fib_validate,
170 static const struct nft_expr_ops *
171 nft_fib4_select_ops(const struct nft_ctx *ctx,
172 const struct nlattr * const tb[])
174 enum nft_fib_result result;
176 if (!tb[NFTA_FIB_RESULT])
177 return ERR_PTR(-EINVAL);
179 result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
182 case NFT_FIB_RESULT_OIF:
183 return &nft_fib4_ops;
184 case NFT_FIB_RESULT_OIFNAME:
185 return &nft_fib4_ops;
186 case NFT_FIB_RESULT_ADDRTYPE:
187 return &nft_fib4_type_ops;
189 return ERR_PTR(-EOPNOTSUPP);
193 static struct nft_expr_type nft_fib4_type __read_mostly = {
195 .select_ops = nft_fib4_select_ops,
196 .policy = nft_fib_policy,
197 .maxattr = NFTA_FIB_MAX,
198 .family = NFPROTO_IPV4,
199 .owner = THIS_MODULE,
202 static int __init nft_fib4_module_init(void)
204 return nft_register_expr(&nft_fib4_type);
207 static void __exit nft_fib4_module_exit(void)
209 nft_unregister_expr(&nft_fib4_type);
212 module_init(nft_fib4_module_init);
213 module_exit(nft_fib4_module_exit);
214 MODULE_LICENSE("GPL");
215 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
216 MODULE_ALIAS_NFT_AF_EXPR(2, "fib");