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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 struct ipv6hdr *iph)
30{
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 struct ipv6hdr *iph)
60{
61 const struct net_device *dev = NULL;
62 const struct nf_ipv6_ops *v6ops;
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 v6ops = nf_get_ipv6_ops();
72 if (!v6ops)
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, iph);
81
82 if (dev && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
83 ret = RTN_LOCAL;
84
85 route_err = v6ops->route(nft_net(pkt), (struct dst_entry **)&rt,
86 flowi6_to_flowi(&fl6), false);
87 if (route_err)
88 goto err;
89
90 if (rt->rt6i_flags & RTF_REJECT) {
91 route_err = rt->dst.error;
92 dst_release(&rt->dst);
93 goto err;
94 }
95
96 if (ipv6_anycast_destination((struct dst_entry *)rt, &fl6.daddr))
97 ret = RTN_ANYCAST;
98 else if (!dev && rt->rt6i_flags & RTF_LOCAL)
99 ret = RTN_LOCAL;
100
101 dst_release(&rt->dst);
102
103 if (ret)
104 return ret;
105
106 addrtype = ipv6_addr_type(&fl6.daddr);
107
108 if (addrtype & IPV6_ADDR_MULTICAST)
109 return RTN_MULTICAST;
110 if (addrtype & IPV6_ADDR_UNICAST)
111 return RTN_UNICAST;
112
113 return RTN_UNSPEC;
114 err:
115 switch (route_err) {
116 case -EINVAL:
117 return RTN_BLACKHOLE;
118 case -EACCES:
119 return RTN_PROHIBIT;
120 case -EAGAIN:
121 return RTN_THROW;
122 default:
123 break;
124 }
125
126 return RTN_UNREACHABLE;
127}
128
129void nft_fib6_eval_type(const struct nft_expr *expr, struct nft_regs *regs,
130 const struct nft_pktinfo *pkt)
131{
132 const struct nft_fib *priv = nft_expr_priv(expr);
133 int noff = skb_network_offset(pkt->skb);
134 u32 *dest = ®s->data[priv->dreg];
135 struct ipv6hdr *iph, _iph;
136
137 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
138 if (!iph) {
139 regs->verdict.code = NFT_BREAK;
140 return;
141 }
142
143 *dest = __nft_fib6_eval_type(priv, pkt, iph);
144}
145EXPORT_SYMBOL_GPL(nft_fib6_eval_type);
146
147void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
148 const struct nft_pktinfo *pkt)
149{
150 const struct nft_fib *priv = nft_expr_priv(expr);
151 int noff = skb_network_offset(pkt->skb);
152 const struct net_device *oif = NULL;
153 u32 *dest = ®s->data[priv->dreg];
154 struct ipv6hdr *iph, _iph;
155 struct flowi6 fl6 = {
156 .flowi6_iif = LOOPBACK_IFINDEX,
157 .flowi6_proto = pkt->tprot,
158 };
159 struct rt6_info *rt;
160 int lookup_flags;
161
162 if (priv->flags & NFTA_FIB_F_IIF)
163 oif = nft_in(pkt);
164 else if (priv->flags & NFTA_FIB_F_OIF)
165 oif = nft_out(pkt);
166
167 iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph);
168 if (!iph) {
169 regs->verdict.code = NFT_BREAK;
170 return;
171 }
172
173 lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif, iph);
174
175 if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
176 nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
177 nft_fib_store_result(dest, priv, pkt,
178 nft_in(pkt)->ifindex);
179 return;
180 }
181
182 *dest = 0;
183 rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, pkt->skb,
184 lookup_flags);
185 if (rt->dst.error)
186 goto put_rt_err;
187
188
189 if (rt->rt6i_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL))
190 goto put_rt_err;
191
192 if (oif && oif != rt->rt6i_idev->dev)
193 goto put_rt_err;
194
195 switch (priv->result) {
196 case NFT_FIB_RESULT_OIF:
197 *dest = rt->rt6i_idev->dev->ifindex;
198 break;
199 case NFT_FIB_RESULT_OIFNAME:
200 strncpy((char *)dest, rt->rt6i_idev->dev->name, IFNAMSIZ);
201 break;
202 default:
203 WARN_ON_ONCE(1);
204 break;
205 }
206
207 put_rt_err:
208 ip6_rt_put(rt);
209}
210EXPORT_SYMBOL_GPL(nft_fib6_eval);
211
212static struct nft_expr_type nft_fib6_type;
213
214static const struct nft_expr_ops nft_fib6_type_ops = {
215 .type = &nft_fib6_type,
216 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
217 .eval = nft_fib6_eval_type,
218 .init = nft_fib_init,
219 .dump = nft_fib_dump,
220 .validate = nft_fib_validate,
221};
222
223static const struct nft_expr_ops nft_fib6_ops = {
224 .type = &nft_fib6_type,
225 .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
226 .eval = nft_fib6_eval,
227 .init = nft_fib_init,
228 .dump = nft_fib_dump,
229 .validate = nft_fib_validate,
230};
231
232static const struct nft_expr_ops *
233nft_fib6_select_ops(const struct nft_ctx *ctx,
234 const struct nlattr * const tb[])
235{
236 enum nft_fib_result result;
237
238 if (!tb[NFTA_FIB_RESULT])
239 return ERR_PTR(-EINVAL);
240
241 result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
242
243 switch (result) {
244 case NFT_FIB_RESULT_OIF:
245 return &nft_fib6_ops;
246 case NFT_FIB_RESULT_OIFNAME:
247 return &nft_fib6_ops;
248 case NFT_FIB_RESULT_ADDRTYPE:
249 return &nft_fib6_type_ops;
250 default:
251 return ERR_PTR(-EOPNOTSUPP);
252 }
253}
254
255static struct nft_expr_type nft_fib6_type __read_mostly = {
256 .name = "fib",
257 .select_ops = nft_fib6_select_ops,
258 .policy = nft_fib_policy,
259 .maxattr = NFTA_FIB_MAX,
260 .family = NFPROTO_IPV6,
261 .owner = THIS_MODULE,
262};
263
264static int __init nft_fib6_module_init(void)
265{
266 return nft_register_expr(&nft_fib6_type);
267}
268
269static void __exit nft_fib6_module_exit(void)
270{
271 nft_unregister_expr(&nft_fib6_type);
272}
273module_init(nft_fib6_module_init);
274module_exit(nft_fib6_module_exit);
275
276MODULE_LICENSE("GPL");
277MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
278MODULE_ALIAS_NFT_AF_EXPR(10, "fib");
279
