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
15struct 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 */
54static inline int rt6_srcprefs2flags(unsigned int srcprefs)
55{
56 return (srcprefs & IPV6_PREFER_SRC_MASK) << 3;
57}
58
59static inline unsigned int rt6_flags2srcprefs(int flags)
60{
61 return (flags >> 3) & IPV6_PREFER_SRC_MASK;
62}
63
64static inline bool rt6_need_strict(const struct in6_addr *daddr)
65{
66 return ipv6_addr_type(addr: 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 */
73static 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
80void ip6_route_input(struct sk_buff *skb);
81struct 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
86struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
87 struct flowi6 *fl6, int flags);
88
89static 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, flags: 0);
94}
95
96/* Only conditionally release dst if flags indicates
97 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list.
98 */
99static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags)
100{
101 if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||
102 !list_empty(head: &rt->dst.rt_uncached))
103 ip6_rt_put(rt);
104}
105
106struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
107 const struct sk_buff *skb, int flags);
108struct 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
112void ip6_route_init_special_entries(void);
113int ip6_route_init(void);
114void ip6_route_cleanup(void);
115
116int ipv6_route_ioctl(struct net *net, unsigned int cmd,
117 struct in6_rtmsg *rtmsg);
118
119int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
120 struct netlink_ext_ack *extack);
121int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
122int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
123
124void rt6_flush_exceptions(struct fib6_info *f6i);
125void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
126 unsigned long now);
127
128static 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, ifindex: 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: 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, dev: same_vrf ? dev : l3mdev, daddr, srcprefs: prefs, saddr);
148
149 rcu_read_unlock();
150
151 return err;
152}
153
154struct 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);
157u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
158 const struct sk_buff *skb, struct flow_keys *hkeys);
159
160struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
161
162void fib6_force_start_gc(struct net *net);
163
164struct 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
168struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
169 int flags);
170
171/*
172 * support functions for ND
173 *
174 */
175struct fib6_info *rt6_get_dflt_router(struct net *net,
176 const struct in6_addr *addr,
177 struct net_device *dev);
178struct 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
184void rt6_purge_dflt_routers(struct net *net);
185
186int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
187 const struct in6_addr *gwaddr);
188
189void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
190 u32 mark, kuid_t uid);
191void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
192void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
193 kuid_t uid);
194void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
195void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
196
197struct netlink_callback;
198
199struct 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
206int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
207void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
208void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
209void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
210void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
211void rt6_disable_ip(struct net_device *dev, unsigned long event);
212void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
213void rt6_multipath_rebalance(struct fib6_info *f6i);
214
215void rt6_uncached_list_add(struct rt6_info *rt);
216void rt6_uncached_list_del(struct rt6_info *rt);
217
218static 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 */
231static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
232 bool daddr_set,
233 bool saddr_set)
234{
235 struct ipv6_pinfo *np = inet6_sk(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_set;
240#ifdef CONFIG_IPV6_SUBTREES
241 np->saddr_cache = saddr_set;
242#endif
243}
244
245void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
246 const struct flowi6 *fl6);
247
248static 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
255static 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(a1: &rt->rt6i_dst.addr, a2: daddr));
264}
265
266int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
267 int (*output)(struct net *, struct sock *, struct sk_buff *));
268
269static 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(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(dst)->mtu);
278 mtu -= lwtunnel_headroom(lwtstate: dst->lwtstate, mtu);
279 } else {
280 mtu = dst_mtu(dst);
281 }
282 return mtu;
283}
284
285static 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
293static 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
301static 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
312static 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(nh1: a->nh, nh2: 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(a1: &nha->fib_nh_gw6, a2: &nhb->fib_nh_gw6) &&
323 !lwtunnel_cmp_encap(a: nha->fib_nh_lws, b: nhb->fib_nh_lws);
324}
325
326static 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(dev: dst_dev_rcu(dst));
341 if (idev)
342 mtu = READ_ONCE(idev->cnf.mtu6);
343 rcu_read_unlock();
344
345out:
346 return mtu - lwtunnel_headroom(lwtstate: dst->lwtstate, mtu);
347}
348
349u32 ip6_mtu_from_fib6(const struct fib6_result *res,
350 const struct in6_addr *daddr,
351 const struct in6_addr *saddr);
352
353struct 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

source code of linux/include/net/ip6_route.h