1 // SPDX-License-Identifier: GPL-2.0-only
3 #include <linux/kernel.h>
4 #include <linux/init.h>
5 #include <linux/module.h>
6 #include <linux/netlink.h>
7 #include <linux/netfilter.h>
8 #include <linux/netfilter/nf_tables.h>
9 #include <linux/netfilter_ipv6.h>
10 #include <net/netfilter/nf_tables_core.h>
11 #include <net/netfilter/nf_tables.h>
12 #include <net/netfilter/nft_fib.h>
14 #include <net/ip6_fib.h>
15 #include <net/ip6_route.h>
17 static int get_ifindex(const struct net_device *dev)
19 return dev ? dev->ifindex : 0;
22 static int nft_fib6_flowi_init(struct flowi6 *fl6, const struct nft_fib *priv,
23 const struct nft_pktinfo *pkt,
24 const struct net_device *dev,
29 if (priv->flags & NFTA_FIB_F_DADDR) {
30 fl6->daddr = iph->daddr;
31 fl6->saddr = iph->saddr;
33 if (nft_hook(pkt) == NF_INET_FORWARD &&
34 priv->flags & NFTA_FIB_F_IIF)
35 fl6->flowi6_iif = nft_out(pkt)->ifindex;
37 fl6->daddr = iph->saddr;
38 fl6->saddr = iph->daddr;
41 if (ipv6_addr_type(&fl6->daddr) & IPV6_ADDR_LINKLOCAL) {
42 lookup_flags |= RT6_LOOKUP_F_IFACE;
43 fl6->flowi6_oif = get_ifindex(dev ? dev : pkt->skb->dev);
44 } else if (priv->flags & NFTA_FIB_F_IIF) {
45 fl6->flowi6_l3mdev = l3mdev_master_ifindex_rcu(dev);
48 if (ipv6_addr_type(&fl6->saddr) & IPV6_ADDR_UNICAST)
49 lookup_flags |= RT6_LOOKUP_F_HAS_SADDR;
51 if (priv->flags & NFTA_FIB_F_MARK)
52 fl6->flowi6_mark = pkt->skb->mark;
54 fl6->flowlabel = (*(__be32 *)iph) & IPV6_FLOWINFO_MASK;
59 static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
60 const struct nft_pktinfo *pkt,
63 const struct net_device *dev = NULL;
64 int route_err, addrtype;
67 .flowi6_iif = LOOPBACK_IFINDEX,
68 .flowi6_proto = pkt->tprot,
69 .flowi6_uid = sock_net_uid(nft_net(pkt), NULL),
73 if (priv->flags & NFTA_FIB_F_IIF)
75 else if (priv->flags & NFTA_FIB_F_OIF)
78 nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);
80 if (dev && nf_ipv6_chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
83 route_err = nf_ip6_route(nft_net(pkt), (struct dst_entry **)&rt,
84 flowi6_to_flowi(&fl6), false);
88 if (rt->rt6i_flags & RTF_REJECT) {
89 route_err = rt->dst.error;
90 dst_release(&rt->dst);
94 if (ipv6_anycast_destination((struct dst_entry *)rt, &fl6.daddr))
96 else if (!dev && rt->rt6i_flags & RTF_LOCAL)
99 dst_release(&rt->dst);
104 addrtype = ipv6_addr_type(&fl6.daddr);
106 if (addrtype & IPV6_ADDR_MULTICAST)
107 return RTN_MULTICAST;
108 if (addrtype & IPV6_ADDR_UNICAST)
115 return RTN_BLACKHOLE;
124 return RTN_UNREACHABLE;
127 void nft_fib6_eval_type(const struct nft_expr *expr, struct nft_regs *regs,
128 const struct nft_pktinfo *pkt)
130 const struct nft_fib *priv = nft_expr_priv(expr);
131 int noff = skb_network_offset(pkt->skb);
132 u32 *dest = ®s->data[priv->dreg];
133 struct ipv6hdr *iph, _iph;
135 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
137 regs->verdict.code = NFT_BREAK;
141 *dest = __nft_fib6_eval_type(priv, pkt, iph);
143 EXPORT_SYMBOL_GPL(nft_fib6_eval_type);
145 static bool nft_fib_v6_skip_icmpv6(const struct sk_buff *skb, u8 next, const struct ipv6hdr *iph)
147 if (likely(next != IPPROTO_ICMPV6))
150 if (ipv6_addr_type(&iph->saddr) != IPV6_ADDR_ANY)
153 return ipv6_addr_type(&iph->daddr) & IPV6_ADDR_LINKLOCAL;
156 void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
157 const struct nft_pktinfo *pkt)
159 const struct nft_fib *priv = nft_expr_priv(expr);
160 int noff = skb_network_offset(pkt->skb);
161 const struct net_device *oif = NULL;
162 u32 *dest = ®s->data[priv->dreg];
163 struct ipv6hdr *iph, _iph;
164 struct flowi6 fl6 = {
165 .flowi6_iif = LOOPBACK_IFINDEX,
166 .flowi6_proto = pkt->tprot,
167 .flowi6_uid = sock_net_uid(nft_net(pkt), NULL),
172 if (priv->flags & NFTA_FIB_F_IIF)
174 else if (priv->flags & NFTA_FIB_F_OIF)
177 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
179 regs->verdict.code = NFT_BREAK;
183 lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif, iph);
185 if (nft_hook(pkt) == NF_INET_PRE_ROUTING ||
186 nft_hook(pkt) == NF_INET_INGRESS) {
187 if (nft_fib_is_loopback(pkt->skb, nft_in(pkt)) ||
188 nft_fib_v6_skip_icmpv6(pkt->skb, pkt->tprot, iph)) {
189 nft_fib_store_result(dest, priv, nft_in(pkt));
195 rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, pkt->skb,
200 /* Should not see RTF_LOCAL here */
201 if (rt->rt6i_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL))
204 if (oif && oif != rt->rt6i_idev->dev &&
205 l3mdev_master_ifindex_rcu(rt->rt6i_idev->dev) != oif->ifindex)
208 nft_fib_store_result(dest, priv, rt->rt6i_idev->dev);
212 EXPORT_SYMBOL_GPL(nft_fib6_eval);
214 static struct nft_expr_type nft_fib6_type;
216 static const struct nft_expr_ops nft_fib6_type_ops = {
217 .type = &nft_fib6_type,
218 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
219 .eval = nft_fib6_eval_type,
220 .init = nft_fib_init,
221 .dump = nft_fib_dump,
222 .validate = nft_fib_validate,
223 .reduce = nft_fib_reduce,
226 static const struct nft_expr_ops nft_fib6_ops = {
227 .type = &nft_fib6_type,
228 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
229 .eval = nft_fib6_eval,
230 .init = nft_fib_init,
231 .dump = nft_fib_dump,
232 .validate = nft_fib_validate,
233 .reduce = nft_fib_reduce,
236 static const struct nft_expr_ops *
237 nft_fib6_select_ops(const struct nft_ctx *ctx,
238 const struct nlattr * const tb[])
240 enum nft_fib_result result;
242 if (!tb[NFTA_FIB_RESULT])
243 return ERR_PTR(-EINVAL);
245 result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
248 case NFT_FIB_RESULT_OIF:
249 return &nft_fib6_ops;
250 case NFT_FIB_RESULT_OIFNAME:
251 return &nft_fib6_ops;
252 case NFT_FIB_RESULT_ADDRTYPE:
253 return &nft_fib6_type_ops;
255 return ERR_PTR(-EOPNOTSUPP);
259 static struct nft_expr_type nft_fib6_type __read_mostly = {
261 .select_ops = nft_fib6_select_ops,
262 .policy = nft_fib_policy,
263 .maxattr = NFTA_FIB_MAX,
264 .family = NFPROTO_IPV6,
265 .owner = THIS_MODULE,
268 static int __init nft_fib6_module_init(void)
270 return nft_register_expr(&nft_fib6_type);
273 static void __exit nft_fib6_module_exit(void)
275 nft_unregister_expr(&nft_fib6_type);
277 module_init(nft_fib6_module_init);
278 module_exit(nft_fib6_module_exit);
280 MODULE_LICENSE("GPL");
281 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
282 MODULE_ALIAS_NFT_AF_EXPR(10, "fib");
283 MODULE_DESCRIPTION("nftables fib / ipv6 route lookup support");