xref: /linux/include/net/ip6_route.h (revision 98838d95075a5295f3478ceba18bcccf472e30f4)
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 <linux/ip.h>
26 #include <linux/ipv6.h>
27 #include <linux/route.h>
28 
29 #define RT6_LOOKUP_F_IFACE		0x00000001
30 #define RT6_LOOKUP_F_REACHABLE		0x00000002
31 #define RT6_LOOKUP_F_HAS_SADDR		0x00000004
32 #define RT6_LOOKUP_F_SRCPREF_TMP	0x00000008
33 #define RT6_LOOKUP_F_SRCPREF_PUBLIC	0x00000010
34 #define RT6_LOOKUP_F_SRCPREF_COA	0x00000020
35 
36 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
37  * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
38  */
39 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
40 
41 /*
42  * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
43  * between IPV6_ADDR_PREFERENCES socket option values
44  *	IPV6_PREFER_SRC_TMP    = 0x1
45  *	IPV6_PREFER_SRC_PUBLIC = 0x2
46  *	IPV6_PREFER_SRC_COA    = 0x4
47  * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
48  */
49 static inline int rt6_srcprefs2flags(unsigned int srcprefs)
50 {
51 	/* No need to bitmask because srcprefs have only 3 bits. */
52 	return srcprefs << 3;
53 }
54 
55 static inline unsigned int rt6_flags2srcprefs(int flags)
56 {
57 	return (flags >> 3) & 7;
58 }
59 
60 static inline bool rt6_need_strict(const struct in6_addr *daddr)
61 {
62 	return ipv6_addr_type(daddr) &
63 		(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
64 }
65 
66 void ip6_route_input(struct sk_buff *skb);
67 struct dst_entry *ip6_route_input_lookup(struct net *net,
68 					 struct net_device *dev,
69 					 struct flowi6 *fl6, int flags);
70 
71 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
72 					 struct flowi6 *fl6, int flags);
73 
74 static inline struct dst_entry *ip6_route_output(struct net *net,
75 						 const struct sock *sk,
76 						 struct flowi6 *fl6)
77 {
78 	return ip6_route_output_flags(net, sk, fl6, 0);
79 }
80 
81 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
82 				   int flags);
83 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
84 			       int ifindex, struct flowi6 *fl6, int flags);
85 
86 int ip6_route_init(void);
87 void ip6_route_cleanup(void);
88 
89 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
90 
91 int ip6_route_add(struct fib6_config *cfg);
92 int ip6_ins_rt(struct rt6_info *);
93 int ip6_del_rt(struct rt6_info *);
94 
95 static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
96 				      const struct in6_addr *daddr,
97 				      unsigned int prefs,
98 				      struct in6_addr *saddr)
99 {
100 	struct inet6_dev *idev =
101 			rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
102 	int err = 0;
103 
104 	if (rt && rt->rt6i_prefsrc.plen)
105 		*saddr = rt->rt6i_prefsrc.addr;
106 	else
107 		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
108 					 daddr, prefs, saddr);
109 
110 	return err;
111 }
112 
113 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
114 			    const struct in6_addr *saddr, int oif, int flags);
115 
116 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
117 int icmp6_dst_gc(void);
118 
119 void fib6_force_start_gc(struct net *net);
120 
121 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
122 				    const struct in6_addr *addr, bool anycast);
123 
124 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
125 			       int flags);
126 
127 /*
128  *	support functions for ND
129  *
130  */
131 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr,
132 				     struct net_device *dev);
133 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
134 				     struct net_device *dev, unsigned int pref);
135 
136 void rt6_purge_dflt_routers(struct net *net);
137 
138 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
139 		  const struct in6_addr *gwaddr);
140 
141 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
142 		     u32 mark);
143 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
144 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark);
145 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
146 			    u32 mark);
147 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
148 
149 struct netlink_callback;
150 
151 struct rt6_rtnl_dump_arg {
152 	struct sk_buff *skb;
153 	struct netlink_callback *cb;
154 	struct net *net;
155 };
156 
157 int rt6_dump_route(struct rt6_info *rt, void *p_arg);
158 void rt6_ifdown(struct net *net, struct net_device *dev);
159 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
160 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
161 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
162 
163 
164 /*
165  *	Store a destination cache entry in a socket
166  */
167 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
168 				 const struct in6_addr *daddr,
169 				 const struct in6_addr *saddr)
170 {
171 	struct ipv6_pinfo *np = inet6_sk(sk);
172 
173 	np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
174 	sk_setup_caps(sk, dst);
175 	np->daddr_cache = daddr;
176 #ifdef CONFIG_IPV6_SUBTREES
177 	np->saddr_cache = saddr;
178 #endif
179 }
180 
181 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
182 {
183 	struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
184 
185 	return rt->rt6i_flags & RTF_LOCAL;
186 }
187 
188 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
189 					    const struct in6_addr *daddr)
190 {
191 	struct rt6_info *rt = (struct rt6_info *)dst;
192 
193 	return rt->rt6i_flags & RTF_ANYCAST ||
194 		(rt->rt6i_dst.plen != 128 &&
195 		 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
196 }
197 
198 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
199 		 int (*output)(struct net *, struct sock *, struct sk_buff *));
200 
201 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
202 {
203 	struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
204 				inet6_sk(skb->sk) : NULL;
205 
206 	return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
207 	       skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
208 }
209 
210 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
211 {
212 	return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
213 	       inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
214 }
215 
216 static inline bool ip6_sk_ignore_df(const struct sock *sk)
217 {
218 	return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
219 	       inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
220 }
221 
222 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
223 					   struct in6_addr *daddr)
224 {
225 	if (rt->rt6i_flags & RTF_GATEWAY)
226 		return &rt->rt6i_gateway;
227 	else if (unlikely(rt->rt6i_flags & RTF_CACHE))
228 		return &rt->rt6i_dst.addr;
229 	else
230 		return daddr;
231 }
232 
233 #endif
234