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, <bir7@leland.Stanford.Edu>
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 <linux/config.h>
28 #include <net/dst.h>
29 #include <net/inetpeer.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 
36 #ifndef __KERNEL__
37 #warning This file is not supposed to be used outside of kernel.
38 #endif
39 
40 #define RTO_ONLINK	0x01
41 
42 #define RTO_CONN	0
43 /* RTO_CONN is not used (being alias for 0), but preserved not to break
44  * some modules referring to it. */
45 
46 #define RT_CONN_FLAGS(sk)   (RT_TOS(sk->protinfo.af_inet.tos) | sk->localroute)
47 
48 struct rt_key
49 {
50 	__u32			dst;
51 	__u32			src;
52 	int			iif;
53 	int			oif;
54 #ifdef CONFIG_IP_ROUTE_FWMARK
55 	__u32			fwmark;
56 #endif
57 	__u8			tos;
58 	__u8			scope;
59 };
60 
61 struct inet_peer;
62 struct rtable
63 {
64 	union
65 	{
66 		struct dst_entry	dst;
67 		struct rtable		*rt_next;
68 	} u;
69 
70 	unsigned		rt_flags;
71 	unsigned		rt_type;
72 
73 	__u32			rt_dst;	/* Path destination	*/
74 	__u32			rt_src;	/* Path source		*/
75 	int			rt_iif;
76 
77 	/* Info on neighbour */
78 	__u32			rt_gateway;
79 
80 	/* Cache lookup keys */
81 	struct rt_key		key;
82 
83 	/* Miscellaneous cached information */
84 	__u32			rt_spec_dst; /* RFC1122 specific destination */
85 	struct inet_peer	*peer; /* long-living peer info */
86 
87 #ifdef CONFIG_IP_ROUTE_NAT
88 	__u32			rt_src_map;
89 	__u32			rt_dst_map;
90 #endif
91 };
92 
93 struct ip_rt_acct
94 {
95 	__u32 	o_bytes;
96 	__u32 	o_packets;
97 	__u32 	i_bytes;
98 	__u32 	i_packets;
99 };
100 
101 struct rt_cache_stat
102 {
103         unsigned int in_hit;
104         unsigned int in_slow_tot;
105         unsigned int in_slow_mc;
106         unsigned int in_no_route;
107         unsigned int in_brd;
108         unsigned int in_martian_dst;
109         unsigned int in_martian_src;
110         unsigned int out_hit;
111         unsigned int out_slow_tot;
112         unsigned int out_slow_mc;
113         unsigned int gc_total;
114         unsigned int gc_ignored;
115         unsigned int gc_goal_miss;
116         unsigned int gc_dst_overflow;
117 	unsigned int in_hlist_search;
118 	unsigned int out_hlist_search;
119 } ____cacheline_aligned_in_smp;
120 
121 extern struct ip_rt_acct *ip_rt_acct;
122 
123 struct in_device;
124 extern void		ip_rt_init(void);
125 extern void		ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
126 				       u32 src, u8 tos, struct net_device *dev);
127 extern void		ip_rt_advice(struct rtable **rp, int advice);
128 extern void		rt_cache_flush(int how);
129 extern int		ip_route_output_key(struct rtable **, const struct rt_key *key);
130 extern int		ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
131 extern unsigned short	ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
132 extern void		ip_rt_update_pmtu(struct dst_entry *dst, unsigned mtu);
133 extern void		ip_rt_send_redirect(struct sk_buff *skb);
134 
135 extern unsigned		inet_addr_type(u32 addr);
136 extern void		ip_rt_multicast_event(struct in_device *);
137 extern int		ip_rt_ioctl(unsigned int cmd, void *arg);
138 extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
139 extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
140 
141 /* Deprecated: use ip_route_output_key directly */
ip_route_output(struct rtable ** rp,u32 daddr,u32 saddr,u32 tos,int oif)142 static inline int ip_route_output(struct rtable **rp,
143 				      u32 daddr, u32 saddr, u32 tos, int oif)
144 {
145 	struct rt_key key = { dst:daddr, src:saddr, oif:oif, tos:tos };
146 
147 	return ip_route_output_key(rp, &key);
148 }
149 
150 
ip_rt_put(struct rtable * rt)151 static inline void ip_rt_put(struct rtable * rt)
152 {
153 	if (rt)
154 		dst_release(&rt->u.dst);
155 }
156 
157 #define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
158 
159 extern __u8 ip_tos2prio[16];
160 
rt_tos2priority(u8 tos)161 static inline char rt_tos2priority(u8 tos)
162 {
163 	return ip_tos2prio[IPTOS_TOS(tos)>>1];
164 }
165 
ip_route_connect(struct rtable ** rp,u32 dst,u32 src,u32 tos,int oif)166 static inline int ip_route_connect(struct rtable **rp, u32 dst, u32 src, u32 tos, int oif)
167 {
168 	int err;
169 	err = ip_route_output(rp, dst, src, tos, oif);
170 	if (err || (dst && src))
171 		return err;
172 	dst = (*rp)->rt_dst;
173 	src = (*rp)->rt_src;
174 	ip_rt_put(*rp);
175 	*rp = NULL;
176 	return ip_route_output(rp, dst, src, tos, oif);
177 }
178 
179 extern void rt_bind_peer(struct rtable *rt, int create);
180 
rt_get_peer(struct rtable * rt)181 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
182 {
183 	if (rt->peer)
184 		return rt->peer;
185 
186 	rt_bind_peer(rt, 0);
187 	return rt->peer;
188 }
189 
190 #endif	/* _ROUTE_H */
191