xref: /openbmc/linux/include/net/ip6_route.h (revision 5a244f48)
1 #ifndef _NET_IP6_ROUTE_H
2 #define _NET_IP6_ROUTE_H
3 
4 struct route_info {
5 	__u8			type;
6 	__u8			length;
7 	__u8			prefix_len;
8 #if defined(__BIG_ENDIAN_BITFIELD)
9 	__u8			reserved_h:3,
10 				route_pref:2,
11 				reserved_l:3;
12 #elif defined(__LITTLE_ENDIAN_BITFIELD)
13 	__u8			reserved_l:3,
14 				route_pref:2,
15 				reserved_h:3;
16 #endif
17 	__be32			lifetime;
18 	__u8			prefix[0];	/* 0,8 or 16 */
19 };
20 
21 #include <net/addrconf.h>
22 #include <net/flow.h>
23 #include <net/ip6_fib.h>
24 #include <net/sock.h>
25 #include <net/lwtunnel.h>
26 #include <linux/ip.h>
27 #include <linux/ipv6.h>
28 #include <linux/route.h>
29 
30 #define RT6_LOOKUP_F_IFACE		0x00000001
31 #define RT6_LOOKUP_F_REACHABLE		0x00000002
32 #define RT6_LOOKUP_F_HAS_SADDR		0x00000004
33 #define RT6_LOOKUP_F_SRCPREF_TMP	0x00000008
34 #define RT6_LOOKUP_F_SRCPREF_PUBLIC	0x00000010
35 #define RT6_LOOKUP_F_SRCPREF_COA	0x00000020
36 #define RT6_LOOKUP_F_IGNORE_LINKSTATE	0x00000040
37 
38 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
39  * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
40  */
41 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
42 
43 /*
44  * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
45  * between IPV6_ADDR_PREFERENCES socket option values
46  *	IPV6_PREFER_SRC_TMP    = 0x1
47  *	IPV6_PREFER_SRC_PUBLIC = 0x2
48  *	IPV6_PREFER_SRC_COA    = 0x4
49  * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
50  */
51 static inline int rt6_srcprefs2flags(unsigned int srcprefs)
52 {
53 	/* No need to bitmask because srcprefs have only 3 bits. */
54 	return srcprefs << 3;
55 }
56 
57 static inline unsigned int rt6_flags2srcprefs(int flags)
58 {
59 	return (flags >> 3) & 7;
60 }
61 
62 static inline bool rt6_need_strict(const struct in6_addr *daddr)
63 {
64 	return ipv6_addr_type(daddr) &
65 		(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
66 }
67 
68 void ip6_route_input(struct sk_buff *skb);
69 struct dst_entry *ip6_route_input_lookup(struct net *net,
70 					 struct net_device *dev,
71 					 struct flowi6 *fl6, int flags);
72 
73 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
74 					 struct flowi6 *fl6, int flags);
75 
76 static inline struct dst_entry *ip6_route_output(struct net *net,
77 						 const struct sock *sk,
78 						 struct flowi6 *fl6)
79 {
80 	return ip6_route_output_flags(net, sk, fl6, 0);
81 }
82 
83 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
84 				   int flags);
85 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
86 			       int ifindex, struct flowi6 *fl6, int flags);
87 
88 void ip6_route_init_special_entries(void);
89 int ip6_route_init(void);
90 void ip6_route_cleanup(void);
91 
92 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
93 
94 int ip6_route_add(struct fib6_config *cfg, struct netlink_ext_ack *extack);
95 int ip6_ins_rt(struct rt6_info *);
96 int ip6_del_rt(struct rt6_info *);
97 
98 static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
99 				      const struct in6_addr *daddr,
100 				      unsigned int prefs,
101 				      struct in6_addr *saddr)
102 {
103 	struct inet6_dev *idev =
104 			rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
105 	int err = 0;
106 
107 	if (rt && rt->rt6i_prefsrc.plen)
108 		*saddr = rt->rt6i_prefsrc.addr;
109 	else
110 		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
111 					 daddr, prefs, saddr);
112 
113 	return err;
114 }
115 
116 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
117 			    const struct in6_addr *saddr, int oif, int flags);
118 u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb);
119 
120 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
121 
122 void fib6_force_start_gc(struct net *net);
123 
124 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
125 				    const struct in6_addr *addr, bool anycast);
126 
127 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
128 			       int flags);
129 
130 /*
131  *	support functions for ND
132  *
133  */
134 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr,
135 				     struct net_device *dev);
136 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
137 				     struct net_device *dev, unsigned int pref);
138 
139 void rt6_purge_dflt_routers(struct net *net);
140 
141 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
142 		  const struct in6_addr *gwaddr);
143 
144 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
145 		     u32 mark, kuid_t uid);
146 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
147 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
148 		  kuid_t uid);
149 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
150 			    u32 mark);
151 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
152 
153 struct netlink_callback;
154 
155 struct rt6_rtnl_dump_arg {
156 	struct sk_buff *skb;
157 	struct netlink_callback *cb;
158 	struct net *net;
159 };
160 
161 int rt6_dump_route(struct rt6_info *rt, void *p_arg);
162 void rt6_ifdown(struct net *net, struct net_device *dev);
163 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
164 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
165 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
166 
167 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
168 {
169 	const struct dst_entry *dst = skb_dst(skb);
170 	const struct rt6_info *rt6 = NULL;
171 
172 	if (dst)
173 		rt6 = container_of(dst, struct rt6_info, dst);
174 
175 	return rt6;
176 }
177 
178 /*
179  *	Store a destination cache entry in a socket
180  */
181 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
182 				 const struct in6_addr *daddr,
183 				 const struct in6_addr *saddr)
184 {
185 	struct ipv6_pinfo *np = inet6_sk(sk);
186 
187 	np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
188 	sk_setup_caps(sk, dst);
189 	np->daddr_cache = daddr;
190 #ifdef CONFIG_IPV6_SUBTREES
191 	np->saddr_cache = saddr;
192 #endif
193 }
194 
195 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
196 {
197 	struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
198 
199 	return rt->rt6i_flags & RTF_LOCAL;
200 }
201 
202 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
203 					    const struct in6_addr *daddr)
204 {
205 	struct rt6_info *rt = (struct rt6_info *)dst;
206 
207 	return rt->rt6i_flags & RTF_ANYCAST ||
208 		(rt->rt6i_dst.plen < 127 &&
209 		 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
210 }
211 
212 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
213 		 int (*output)(struct net *, struct sock *, struct sk_buff *));
214 
215 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
216 {
217 	struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
218 				inet6_sk(skb->sk) : NULL;
219 
220 	return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
221 	       skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
222 }
223 
224 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
225 {
226 	return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
227 	       inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
228 }
229 
230 static inline bool ip6_sk_ignore_df(const struct sock *sk)
231 {
232 	return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
233 	       inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
234 }
235 
236 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
237 					   struct in6_addr *daddr)
238 {
239 	if (rt->rt6i_flags & RTF_GATEWAY)
240 		return &rt->rt6i_gateway;
241 	else if (unlikely(rt->rt6i_flags & RTF_CACHE))
242 		return &rt->rt6i_dst.addr;
243 	else
244 		return daddr;
245 }
246 
247 static inline bool rt6_duplicate_nexthop(struct rt6_info *a, struct rt6_info *b)
248 {
249 	return a->dst.dev == b->dst.dev &&
250 	       a->rt6i_idev == b->rt6i_idev &&
251 	       ipv6_addr_equal(&a->rt6i_gateway, &b->rt6i_gateway) &&
252 	       !lwtunnel_cmp_encap(a->dst.lwtstate, b->dst.lwtstate);
253 }
254 #endif
255