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 u32 *dst = ®s->data[priv->dreg];
36 const struct net_device *dev = NULL;
37 const struct iphdr *iph;
40 if (priv->flags & NFTA_FIB_F_IIF)
42 else if (priv->flags & NFTA_FIB_F_OIF)
45 iph = ip_hdr(pkt->skb);
46 if (priv->flags & NFTA_FIB_F_DADDR)
51 *dst = inet_dev_addr_type(nft_net(pkt), dev, addr);
53 EXPORT_SYMBOL_GPL(nft_fib4_eval_type);
55 static int get_ifindex(const struct net_device *dev)
57 return dev ? dev->ifindex : 0;
60 void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs,
61 const struct nft_pktinfo *pkt)
63 const struct nft_fib *priv = nft_expr_priv(expr);
64 u32 *dest = ®s->data[priv->dreg];
65 const struct iphdr *iph;
66 struct fib_result res;
68 .flowi4_scope = RT_SCOPE_UNIVERSE,
69 .flowi4_iif = LOOPBACK_IFINDEX,
71 const struct net_device *oif;
72 struct net_device *found;
73 #ifdef CONFIG_IP_ROUTE_MULTIPATH
78 * Do not set flowi4_oif, it restricts results (for example, asking
79 * for oif 3 will get RTN_UNICAST result even if the daddr exits
80 * on another interface.
82 * Search results for the desired outinterface instead.
84 if (priv->flags & NFTA_FIB_F_OIF)
86 else if (priv->flags & NFTA_FIB_F_IIF)
91 if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
92 nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
93 nft_fib_store_result(dest, priv, pkt,
94 nft_in(pkt)->ifindex);
98 iph = ip_hdr(pkt->skb);
99 if (ipv4_is_zeronet(iph->saddr)) {
100 if (ipv4_is_lbcast(iph->daddr) ||
101 ipv4_is_local_multicast(iph->daddr)) {
102 nft_fib_store_result(dest, priv, pkt,
103 get_ifindex(pkt->skb->dev));
108 if (priv->flags & NFTA_FIB_F_MARK)
109 fl4.flowi4_mark = pkt->skb->mark;
111 fl4.flowi4_tos = iph->tos & DSCP_BITS;
113 if (priv->flags & NFTA_FIB_F_DADDR) {
114 fl4.daddr = iph->daddr;
115 fl4.saddr = get_saddr(iph->saddr);
117 fl4.daddr = iph->saddr;
118 fl4.saddr = get_saddr(iph->daddr);
123 if (fib_lookup(nft_net(pkt), &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE))
129 case RTN_LOCAL: /* Should not see RTN_LOCAL here */
136 found = FIB_RES_DEV(res);
140 #ifdef CONFIG_IP_ROUTE_MULTIPATH
141 for (i = 0; i < res.fi->fib_nhs; i++) {
142 struct fib_nh *nh = &res.fi->fib_nh[i];
144 if (nh->nh_dev == oif) {
151 found = FIB_RES_DEV(res);
156 switch (priv->result) {
157 case NFT_FIB_RESULT_OIF:
158 *dest = found->ifindex;
160 case NFT_FIB_RESULT_OIFNAME:
161 strncpy((char *)dest, found->name, IFNAMSIZ);
168 EXPORT_SYMBOL_GPL(nft_fib4_eval);
170 static struct nft_expr_type nft_fib4_type;
172 static const struct nft_expr_ops nft_fib4_type_ops = {
173 .type = &nft_fib4_type,
174 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
175 .eval = nft_fib4_eval_type,
176 .init = nft_fib_init,
177 .dump = nft_fib_dump,
178 .validate = nft_fib_validate,
181 static const struct nft_expr_ops nft_fib4_ops = {
182 .type = &nft_fib4_type,
183 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
184 .eval = nft_fib4_eval,
185 .init = nft_fib_init,
186 .dump = nft_fib_dump,
187 .validate = nft_fib_validate,
190 static const struct nft_expr_ops *
191 nft_fib4_select_ops(const struct nft_ctx *ctx,
192 const struct nlattr * const tb[])
194 enum nft_fib_result result;
196 if (!tb[NFTA_FIB_RESULT])
197 return ERR_PTR(-EINVAL);
199 result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
202 case NFT_FIB_RESULT_OIF:
203 return &nft_fib4_ops;
204 case NFT_FIB_RESULT_OIFNAME:
205 return &nft_fib4_ops;
206 case NFT_FIB_RESULT_ADDRTYPE:
207 return &nft_fib4_type_ops;
209 return ERR_PTR(-EOPNOTSUPP);
213 static struct nft_expr_type nft_fib4_type __read_mostly = {
215 .select_ops = nft_fib4_select_ops,
216 .policy = nft_fib_policy,
217 .maxattr = NFTA_FIB_MAX,
218 .family = NFPROTO_IPV4,
219 .owner = THIS_MODULE,
222 static int __init nft_fib4_module_init(void)
224 return nft_register_expr(&nft_fib4_type);
227 static void __exit nft_fib4_module_exit(void)
229 nft_unregister_expr(&nft_fib4_type);
232 module_init(nft_fib4_module_init);
233 module_exit(nft_fib4_module_exit);
234 MODULE_LICENSE("GPL");
235 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
236 MODULE_ALIAS_NFT_AF_EXPR(2, "fib");