xref: /linux/include/net/route.h (revision bd0561c9d8dcbf21cd9aa46c416bbf6a3a12e4b1)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET  is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for the IP router.
7  *
8  * Version:	@(#)route.h	1.0.4	05/27/93
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  * Fixes:
13  *		Alan Cox	:	Reformatted. Added ip_rt_local()
14  *		Alan Cox	:	Support for TCP parameters.
15  *		Alexey Kuznetsov:	Major changes for new routing code.
16  *		Mike McLagan    :	Routing by source
17  *		Robert Olsson   :	Added rt_cache statistics
18  *
19  *		This program is free software; you can redistribute it and/or
20  *		modify it under the terms of the GNU General Public License
21  *		as published by the Free Software Foundation; either version
22  *		2 of the License, or (at your option) any later version.
23  */
24 #ifndef _ROUTE_H
25 #define _ROUTE_H
26 
27 #include <net/dst.h>
28 #include <net/inetpeer.h>
29 #include <net/flow.h>
30 #include <linux/in_route.h>
31 #include <linux/rtnetlink.h>
32 #include <linux/route.h>
33 #include <linux/ip.h>
34 #include <linux/cache.h>
35 #include <linux/security.h>
36 
37 #ifndef __KERNEL__
38 #warning This file is not supposed to be used outside of kernel.
39 #endif
40 
41 #define RTO_ONLINK	0x01
42 
43 #define RTO_CONN	0
44 /* RTO_CONN is not used (being alias for 0), but preserved not to break
45  * some modules referring to it. */
46 
47 #define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
48 
49 struct fib_nh;
50 struct inet_peer;
51 struct rtable
52 {
53 	union
54 	{
55 		struct dst_entry	dst;
56 		struct rtable		*rt_next;
57 	} u;
58 
59 	struct in_device	*idev;
60 
61 	unsigned		rt_flags;
62 	__u16			rt_type;
63 	__u16			rt_multipath_alg;
64 
65 	__be32			rt_dst;	/* Path destination	*/
66 	__be32			rt_src;	/* Path source		*/
67 	int			rt_iif;
68 
69 	/* Info on neighbour */
70 	__be32			rt_gateway;
71 
72 	/* Cache lookup keys */
73 	struct flowi		fl;
74 
75 	/* Miscellaneous cached information */
76 	__be32			rt_spec_dst; /* RFC1122 specific destination */
77 	struct inet_peer	*peer; /* long-living peer info */
78 };
79 
80 struct ip_rt_acct
81 {
82 	__u32 	o_bytes;
83 	__u32 	o_packets;
84 	__u32 	i_bytes;
85 	__u32 	i_packets;
86 };
87 
88 struct rt_cache_stat
89 {
90         unsigned int in_hit;
91         unsigned int in_slow_tot;
92         unsigned int in_slow_mc;
93         unsigned int in_no_route;
94         unsigned int in_brd;
95         unsigned int in_martian_dst;
96         unsigned int in_martian_src;
97         unsigned int out_hit;
98         unsigned int out_slow_tot;
99         unsigned int out_slow_mc;
100         unsigned int gc_total;
101         unsigned int gc_ignored;
102         unsigned int gc_goal_miss;
103         unsigned int gc_dst_overflow;
104         unsigned int in_hlist_search;
105         unsigned int out_hlist_search;
106 };
107 
108 extern struct ip_rt_acct *ip_rt_acct;
109 
110 struct in_device;
111 extern int		ip_rt_init(void);
112 extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
113 				       __be32 src, struct net_device *dev);
114 extern void		ip_rt_advice(struct rtable **rp, int advice);
115 extern void		rt_cache_flush(int how);
116 extern int		__ip_route_output_key(struct rtable **, const struct flowi *flp);
117 extern int		ip_route_output_key(struct rtable **, struct flowi *flp);
118 extern int		ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
119 extern int		ip_route_input(struct sk_buff*, __be32 dst, __be32 src, u8 tos, struct net_device *devin);
120 extern unsigned short	ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
121 extern void		ip_rt_send_redirect(struct sk_buff *skb);
122 
123 extern unsigned		inet_addr_type(__be32 addr);
124 extern void		ip_rt_multicast_event(struct in_device *);
125 extern int		ip_rt_ioctl(unsigned int cmd, void __user *arg);
126 extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
127 extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
128 
129 struct in_ifaddr;
130 extern void fib_add_ifaddr(struct in_ifaddr *);
131 
132 static inline void ip_rt_put(struct rtable * rt)
133 {
134 	if (rt)
135 		dst_release(&rt->u.dst);
136 }
137 
138 #define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
139 
140 extern __u8 ip_tos2prio[16];
141 
142 static inline char rt_tos2priority(u8 tos)
143 {
144 	return ip_tos2prio[IPTOS_TOS(tos)>>1];
145 }
146 
147 static inline int ip_route_connect(struct rtable **rp, __be32 dst,
148 				   __be32 src, u32 tos, int oif, u8 protocol,
149 				   __be16 sport, __be16 dport, struct sock *sk,
150 				   int flags)
151 {
152 	struct flowi fl = { .oif = oif,
153 			    .nl_u = { .ip4_u = { .daddr = dst,
154 						 .saddr = src,
155 						 .tos   = tos } },
156 			    .proto = protocol,
157 			    .uli_u = { .ports =
158 				       { .sport = sport,
159 					 .dport = dport } } };
160 
161 	int err;
162 	if (!dst || !src) {
163 		err = __ip_route_output_key(rp, &fl);
164 		if (err)
165 			return err;
166 		fl.fl4_dst = (*rp)->rt_dst;
167 		fl.fl4_src = (*rp)->rt_src;
168 		ip_rt_put(*rp);
169 		*rp = NULL;
170 	}
171 	security_sk_classify_flow(sk, &fl);
172 	return ip_route_output_flow(rp, &fl, sk, flags);
173 }
174 
175 static inline int ip_route_newports(struct rtable **rp, u8 protocol,
176 				    __be16 sport, __be16 dport, struct sock *sk)
177 {
178 	if (sport != (*rp)->fl.fl_ip_sport ||
179 	    dport != (*rp)->fl.fl_ip_dport) {
180 		struct flowi fl;
181 
182 		memcpy(&fl, &(*rp)->fl, sizeof(fl));
183 		fl.fl_ip_sport = sport;
184 		fl.fl_ip_dport = dport;
185 		fl.proto = protocol;
186 		ip_rt_put(*rp);
187 		*rp = NULL;
188 		security_sk_classify_flow(sk, &fl);
189 		return ip_route_output_flow(rp, &fl, sk, 0);
190 	}
191 	return 0;
192 }
193 
194 extern void rt_bind_peer(struct rtable *rt, int create);
195 
196 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
197 {
198 	if (rt->peer)
199 		return rt->peer;
200 
201 	rt_bind_peer(rt, 0);
202 	return rt->peer;
203 }
204 
205 extern ctl_table ipv4_route_table[];
206 
207 #endif	/* _ROUTE_H */
208