1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_IP6_ROUTE_H
3 #define _NET_IP6_ROUTE_H
4
5 #include <net/addrconf.h>
6 #include <net/flow.h>
7 #include <net/ip6_fib.h>
8 #include <net/sock.h>
9 #include <net/lwtunnel.h>
10 #include <linux/ip.h>
11 #include <linux/ipv6.h>
12 #include <linux/route.h>
13 #include <net/nexthop.h>
14
15 struct route_info {
16 __u8 type;
17 __u8 length;
18 __u8 prefix_len;
19 #if defined(__BIG_ENDIAN_BITFIELD)
20 __u8 reserved_h:3,
21 route_pref:2,
22 reserved_l:3;
23 #elif defined(__LITTLE_ENDIAN_BITFIELD)
24 __u8 reserved_l:3,
25 route_pref:2,
26 reserved_h:3;
27 #endif
28 __be32 lifetime;
29 __u8 prefix[]; /* 0,8 or 16 */
30 };
31
32 #define RT6_LOOKUP_F_IFACE 0x00000001
33 #define RT6_LOOKUP_F_REACHABLE 0x00000002
34 #define RT6_LOOKUP_F_HAS_SADDR 0x00000004
35 #define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008
36 #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010
37 #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020
38 #define RT6_LOOKUP_F_IGNORE_LINKSTATE 0x00000040
39 #define RT6_LOOKUP_F_DST_NOREF 0x00000080
40
41 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
42 * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
43 */
44 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
45
46 /*
47 * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
48 * between IPV6_ADDR_PREFERENCES socket option values
49 * IPV6_PREFER_SRC_TMP = 0x1
50 * IPV6_PREFER_SRC_PUBLIC = 0x2
51 * IPV6_PREFER_SRC_COA = 0x4
52 * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
53 */
54 static inline int rt6_srcprefs2flags(unsigned int srcprefs)
55 {
56 return (srcprefs & IPV6_PREFER_SRC_MASK) << 3;
57 }
58
59 static inline unsigned int rt6_flags2srcprefs(int flags)
60 {
61 return (flags >> 3) & IPV6_PREFER_SRC_MASK;
62 }
63
64 static inline bool rt6_need_strict(const struct in6_addr *daddr)
65 {
66 return ipv6_addr_type(daddr) &
67 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
68 }
69
70 /* fib entries using a nexthop object can not be coalesced into
71 * a multipath route
72 */
73 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
74 {
75 /* the RTF_ADDRCONF flag filters out RA's */
76 return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh &&
77 f6i->fib6_nh->fib_nh_gw_family;
78 }
79
80 void ip6_route_input(struct sk_buff *skb);
81 struct dst_entry *ip6_route_input_lookup(struct net *net,
82 struct net_device *dev,
83 struct flowi6 *fl6,
84 const struct sk_buff *skb, int flags);
85
86 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
87 struct flowi6 *fl6, int flags);
88
89 static inline struct dst_entry *ip6_route_output(struct net *net,
90 const struct sock *sk,
91 struct flowi6 *fl6)
92 {
93 return ip6_route_output_flags(net, sk, fl6, 0);
94 }
95
96 /* Only conditionally release dst if flags indicates
97 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list.
98 */
99 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags)
100 {
101 if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||
102 !list_empty(&rt->dst.rt_uncached))
103 ip6_rt_put(rt);
104 }
105
106 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
107 const struct sk_buff *skb, int flags);
108 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
109 int ifindex, struct flowi6 *fl6,
110 const struct sk_buff *skb, int flags);
111
112 void ip6_route_init_special_entries(void);
113 int ip6_route_init(void);
114 void ip6_route_cleanup(void);
115
116 int ipv6_route_ioctl(struct net *net, unsigned int cmd,
117 struct in6_rtmsg *rtmsg);
118
119 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
120 struct netlink_ext_ack *extack);
121 int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
122 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
123
124 void rt6_flush_exceptions(struct fib6_info *f6i);
125 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
126 unsigned long now);
127
128 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,
129 const struct in6_addr *daddr,
130 unsigned int prefs, int l3mdev_index,
131 struct in6_addr *saddr)
132 {
133 struct net_device *l3mdev;
134 struct net_device *dev;
135 bool same_vrf;
136 int err = 0;
137
138 rcu_read_lock();
139
140 l3mdev = dev_get_by_index_rcu(net, l3mdev_index);
141 if (!f6i || !f6i->fib6_prefsrc.plen || l3mdev)
142 dev = f6i ? fib6_info_nh_dev(f6i) : NULL;
143 same_vrf = !l3mdev || l3mdev_master_dev_rcu(dev) == l3mdev;
144 if (f6i && f6i->fib6_prefsrc.plen && same_vrf)
145 *saddr = f6i->fib6_prefsrc.addr;
146 else
147 err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr);
148
149 rcu_read_unlock();
150
151 return err;
152 }
153
154 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
155 const struct in6_addr *saddr, int oif,
156 const struct sk_buff *skb, int flags);
157 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
158 const struct sk_buff *skb, struct flow_keys *hkeys);
159
160 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
161
162 void fib6_force_start_gc(struct net *net);
163
164 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
165 const struct in6_addr *addr, bool anycast,
166 gfp_t gfp_flags, struct netlink_ext_ack *extack);
167
168 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
169 int flags);
170
171 /*
172 * support functions for ND
173 *
174 */
175 struct fib6_info *rt6_get_dflt_router(struct net *net,
176 const struct in6_addr *addr,
177 struct net_device *dev);
178 struct fib6_info *rt6_add_dflt_router(struct net *net,
179 const struct in6_addr *gwaddr,
180 struct net_device *dev, unsigned int pref,
181 u32 defrtr_usr_metric,
182 int lifetime);
183
184 void rt6_purge_dflt_routers(struct net *net);
185
186 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
187 const struct in6_addr *gwaddr);
188
189 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
190 u32 mark, kuid_t uid);
191 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
192 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
193 kuid_t uid);
194 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
195 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
196
197 struct netlink_callback;
198
199 struct rt6_rtnl_dump_arg {
200 struct sk_buff *skb;
201 struct netlink_callback *cb;
202 struct net *net;
203 struct fib_dump_filter filter;
204 };
205
206 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
207 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
208 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
209 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
210 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
211 void rt6_disable_ip(struct net_device *dev, unsigned long event);
212 void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
213 void rt6_multipath_rebalance(struct fib6_info *f6i);
214
215 void rt6_uncached_list_add(struct rt6_info *rt);
216 void rt6_uncached_list_del(struct rt6_info *rt);
217
218 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
219 {
220 const struct dst_entry *dst = skb_dst(skb);
221
222 if (dst)
223 return dst_rt6_info(dst);
224
225 return NULL;
226 }
227
228 /*
229 * Store a destination cache entry in a socket
230 */
231 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
232 const struct in6_addr *daddr,
233 const struct in6_addr *saddr)
234 {
235 struct ipv6_pinfo *np = inet6_sk(sk);
236
237 np->dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
238 sk_setup_caps(sk, dst);
239 np->daddr_cache = daddr;
240 #ifdef CONFIG_IPV6_SUBTREES
241 np->saddr_cache = saddr;
242 #endif
243 }
244
245 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
246 const struct flowi6 *fl6);
247
248 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
249 {
250 const struct rt6_info *rt = dst_rt6_info(skb_dst(skb));
251
252 return rt->rt6i_flags & RTF_LOCAL;
253 }
254
255 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
256 const struct in6_addr *daddr)
257 {
258 const struct rt6_info *rt = dst_rt6_info(dst);
259
260 return rt->rt6i_flags & RTF_ANYCAST ||
261 (rt->rt6i_dst.plen < 127 &&
262 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&
263 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
264 }
265
266 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
267 int (*output)(struct net *, struct sock *, struct sk_buff *));
268
269 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb)
270 {
271 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
272 inet6_sk(skb->sk) : NULL;
273 const struct dst_entry *dst = skb_dst(skb);
274 unsigned int mtu;
275
276 if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) {
277 mtu = READ_ONCE(dst->dev->mtu);
278 mtu -= lwtunnel_headroom(dst->lwtstate, mtu);
279 } else {
280 mtu = dst_mtu(dst);
281 }
282 return mtu;
283 }
284
285 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
286 {
287 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc);
288
289 return pmtudisc != IPV6_PMTUDISC_INTERFACE &&
290 pmtudisc != IPV6_PMTUDISC_OMIT;
291 }
292
293 static inline bool ip6_sk_ignore_df(const struct sock *sk)
294 {
295 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc);
296
297 return pmtudisc < IPV6_PMTUDISC_DO ||
298 pmtudisc == IPV6_PMTUDISC_OMIT;
299 }
300
301 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,
302 const struct in6_addr *daddr)
303 {
304 if (rt->rt6i_flags & RTF_GATEWAY)
305 return &rt->rt6i_gateway;
306 else if (unlikely(rt->rt6i_flags & RTF_CACHE))
307 return &rt->rt6i_dst.addr;
308 else
309 return daddr;
310 }
311
312 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
313 {
314 struct fib6_nh *nha, *nhb;
315
316 if (a->nh || b->nh)
317 return nexthop_cmp(a->nh, b->nh);
318
319 nha = a->fib6_nh;
320 nhb = b->fib6_nh;
321 return nha->fib_nh_dev == nhb->fib_nh_dev &&
322 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&
323 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);
324 }
325
326 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst,
327 bool forwarding)
328 {
329 struct inet6_dev *idev;
330 unsigned int mtu;
331
332 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) {
333 mtu = dst_metric_raw(dst, RTAX_MTU);
334 if (mtu)
335 goto out;
336 }
337
338 mtu = IPV6_MIN_MTU;
339 rcu_read_lock();
340 idev = __in6_dev_get(dst->dev);
341 if (idev)
342 mtu = READ_ONCE(idev->cnf.mtu6);
343 rcu_read_unlock();
344
345 out:
346 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
347 }
348
349 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
350 const struct in6_addr *daddr,
351 const struct in6_addr *saddr);
352
353 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
354 struct net_device *dev, struct sk_buff *skb,
355 const void *daddr);
356 #endif
357
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