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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 <linux/netfilter_ipv6.h>
14#include <net/netfilter/nf_tables_core.h>
15#include <net/netfilter/nf_tables.h>
16#include <net/netfilter/nft_fib.h>
17
18#include <net/ip6_fib.h>
19#include <net/ip6_route.h>
20
21static int get_ifindex(const struct net_device *dev)
22{
23 return dev ? dev->ifindex : 0;
24}
25
26static int nft_fib6_flowi_init(struct flowi6 *fl6, const struct nft_fib *priv,
27 const struct nft_pktinfo *pkt,
28 const struct net_device *dev)
29{
30 const struct ipv6hdr *iph = ipv6_hdr(pkt->skb);
31 int lookup_flags = 0;
32
33 if (priv->flags & NFTA_FIB_F_DADDR) {
34 fl6->daddr = iph->daddr;
35 fl6->saddr = iph->saddr;
36 } else {
37 fl6->daddr = iph->saddr;
38 fl6->saddr = iph->daddr;
39 }
40
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 }
45
46 if (ipv6_addr_type(&fl6->saddr) & IPV6_ADDR_UNICAST)
47 lookup_flags |= RT6_LOOKUP_F_HAS_SADDR;
48
49 if (priv->flags & NFTA_FIB_F_MARK)
50 fl6->flowi6_mark = pkt->skb->mark;
51
52 fl6->flowlabel = (*(__be32 *)iph) & IPV6_FLOWINFO_MASK;
53
54 return lookup_flags;
55}
56
57static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
58 const struct nft_pktinfo *pkt)
59{
60 const struct net_device *dev = NULL;
61 const struct nf_ipv6_ops *v6ops;
62 const struct nf_afinfo *afinfo;
63 int route_err, addrtype;
64 struct rt6_info *rt;
65 struct flowi6 fl6 = {
66 .flowi6_iif = LOOPBACK_IFINDEX,
67 .flowi6_proto = pkt->tprot,
68 };
69 u32 ret = 0;
70
71 afinfo = nf_get_afinfo(NFPROTO_IPV6);
72 if (!afinfo)
73 return RTN_UNREACHABLE;
74
75 if (priv->flags & NFTA_FIB_F_IIF)
76 dev = nft_in(pkt);
77 else if (priv->flags & NFTA_FIB_F_OIF)
78 dev = nft_out(pkt);
79
80 nft_fib6_flowi_init(&fl6, priv, pkt, dev);
81
82 v6ops = nf_get_ipv6_ops();
83 if (dev && v6ops && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
84 ret = RTN_LOCAL;
85
86 route_err = afinfo->route(nft_net(pkt), (struct dst_entry **)&rt,
87 flowi6_to_flowi(&fl6), false);
88 if (route_err)
89 goto err;
90
91 if (rt->rt6i_flags & RTF_REJECT) {
92 route_err = rt->dst.error;
93 dst_release(&rt->dst);
94 goto err;
95 }
96
97 if (ipv6_anycast_destination((struct dst_entry *)rt, &fl6.daddr))
98 ret = RTN_ANYCAST;
99 else if (!dev && rt->rt6i_flags & RTF_LOCAL)
100 ret = RTN_LOCAL;
101
102 dst_release(&rt->dst);
103
104 if (ret)
105 return ret;
106
107 addrtype = ipv6_addr_type(&fl6.daddr);
108
109 if (addrtype & IPV6_ADDR_MULTICAST)
110 return RTN_MULTICAST;
111 if (addrtype & IPV6_ADDR_UNICAST)
112 return RTN_UNICAST;
113
114 return RTN_UNSPEC;
115 err:
116 switch (route_err) {
117 case -EINVAL:
118 return RTN_BLACKHOLE;
119 case -EACCES:
120 return RTN_PROHIBIT;
121 case -EAGAIN:
122 return RTN_THROW;
123 default:
124 break;
125 }
126
127 return RTN_UNREACHABLE;
128}
129
130void nft_fib6_eval_type(const struct nft_expr *expr, struct nft_regs *regs,
131 const struct nft_pktinfo *pkt)
132{
133 const struct nft_fib *priv = nft_expr_priv(expr);
134 u32 *dest = ®s->data[priv->dreg];
135
136 *dest = __nft_fib6_eval_type(priv, pkt);
137}
138EXPORT_SYMBOL_GPL(nft_fib6_eval_type);
139
140void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
141 const struct nft_pktinfo *pkt)
142{
143 const struct nft_fib *priv = nft_expr_priv(expr);
144 const struct net_device *oif = NULL;
145 u32 *dest = ®s->data[priv->dreg];
146 struct flowi6 fl6 = {
147 .flowi6_iif = LOOPBACK_IFINDEX,
148 .flowi6_proto = pkt->tprot,
149 };
150 struct rt6_info *rt;
151 int lookup_flags;
152
153 if (priv->flags & NFTA_FIB_F_IIF)
154 oif = nft_in(pkt);
155 else if (priv->flags & NFTA_FIB_F_OIF)
156 oif = nft_out(pkt);
157
158 lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif);
159
160 if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
161 nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
162 nft_fib_store_result(dest, priv, pkt,
163 nft_in(pkt)->ifindex);
164 return;
165 }
166
167 *dest = 0;
168 again:
169 rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, lookup_flags);
170 if (rt->dst.error)
171 goto put_rt_err;
172
173
174 if (rt->rt6i_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL))
175 goto put_rt_err;
176
177 if (oif && oif != rt->rt6i_idev->dev) {
178
179 if ((lookup_flags & RT6_LOOKUP_F_IFACE) == 0) {
180 lookup_flags |= RT6_LOOKUP_F_IFACE;
181 fl6.flowi6_oif = oif->ifindex;
182 ip6_rt_put(rt);
183 goto again;
184 }
185 }
186
187 switch (priv->result) {
188 case NFT_FIB_RESULT_OIF:
189 *dest = rt->rt6i_idev->dev->ifindex;
190 break;
191 case NFT_FIB_RESULT_OIFNAME:
192 strncpy((char *)dest, rt->rt6i_idev->dev->name, IFNAMSIZ);
193 break;
194 default:
195 WARN_ON_ONCE(1);
196 break;
197 }
198
199 put_rt_err:
200 ip6_rt_put(rt);
201}
202EXPORT_SYMBOL_GPL(nft_fib6_eval);
203
204static struct nft_expr_type nft_fib6_type;
205
206static const struct nft_expr_ops nft_fib6_type_ops = {
207 .type = &nft_fib6_type,
208 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
209 .eval = nft_fib6_eval_type,
210 .init = nft_fib_init,
211 .dump = nft_fib_dump,
212 .validate = nft_fib_validate,
213};
214
215static const struct nft_expr_ops nft_fib6_ops = {
216 .type = &nft_fib6_type,
217 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
218 .eval = nft_fib6_eval,
219 .init = nft_fib_init,
220 .dump = nft_fib_dump,
221 .validate = nft_fib_validate,
222};
223
224static const struct nft_expr_ops *
225nft_fib6_select_ops(const struct nft_ctx *ctx,
226 const struct nlattr * const tb[])
227{
228 enum nft_fib_result result;
229
230 if (!tb[NFTA_FIB_RESULT])
231 return ERR_PTR(-EINVAL);
232
233 result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
234
235 switch (result) {
236 case NFT_FIB_RESULT_OIF:
237 return &nft_fib6_ops;
238 case NFT_FIB_RESULT_OIFNAME:
239 return &nft_fib6_ops;
240 case NFT_FIB_RESULT_ADDRTYPE:
241 return &nft_fib6_type_ops;
242 default:
243 return ERR_PTR(-EOPNOTSUPP);
244 }
245}
246
247static struct nft_expr_type nft_fib6_type __read_mostly = {
248 .name = "fib",
249 .select_ops = nft_fib6_select_ops,
250 .policy = nft_fib_policy,
251 .maxattr = NFTA_FIB_MAX,
252 .family = NFPROTO_IPV6,
253 .owner = THIS_MODULE,
254};
255
256static int __init nft_fib6_module_init(void)
257{
258 return nft_register_expr(&nft_fib6_type);
259}
260
261static void __exit nft_fib6_module_exit(void)
262{
263 nft_unregister_expr(&nft_fib6_type);
264}
265module_init(nft_fib6_module_init);
266module_exit(nft_fib6_module_exit);
267
268MODULE_LICENSE("GPL");
269MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
270MODULE_ALIAS_NFT_AF_EXPR(10, "fib");
271
