route.h revision 37e20a66db02eff9adbeee043af990cca85d0034 
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 <linux/config.h>
28#include <net/dst.h>
29#include <net/inetpeer.h>
30#include <net/flow.h>
31#include <linux/in_route.h>
32#include <linux/rtnetlink.h>
33#include <linux/route.h>
34#include <linux/ip.h>
35#include <linux/cache.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
49struct fib_nh;
50struct inet_peer;
51struct 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	__u32			rt_dst;	/* Path destination	*/
66	__u32			rt_src;	/* Path source		*/
67	int			rt_iif;
68
69	/* Info on neighbour */
70	__u32			rt_gateway;
71
72	/* Cache lookup keys */
73	struct flowi		fl;
74
75	/* Miscellaneous cached information */
76	__u32			rt_spec_dst; /* RFC1122 specific destination */
77	struct inet_peer	*peer; /* long-living peer info */
78};
79
80struct ip_rt_acct
81{
82	__u32 	o_bytes;
83	__u32 	o_packets;
84	__u32 	i_bytes;
85	__u32 	i_packets;
86};
87
88struct 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
108extern struct rt_cache_stat *rt_cache_stat;
109#define RT_CACHE_STAT_INC(field)					  \
110		(per_cpu_ptr(rt_cache_stat, _smp_processor_id())->field++)
111
112extern struct ip_rt_acct *ip_rt_acct;
113
114struct in_device;
115extern int		ip_rt_init(void);
116extern void		ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
117				       u32 src, u8 tos, struct net_device *dev);
118extern void		ip_rt_advice(struct rtable **rp, int advice);
119extern void		rt_cache_flush(int how);
120extern int		__ip_route_output_key(struct rtable **, const struct flowi *flp);
121extern int		ip_route_output_key(struct rtable **, struct flowi *flp);
122extern int		ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
123extern int		ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
124extern unsigned short	ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
125extern void		ip_rt_send_redirect(struct sk_buff *skb);
126
127extern unsigned		inet_addr_type(u32 addr);
128extern void		ip_rt_multicast_event(struct in_device *);
129extern int		ip_rt_ioctl(unsigned int cmd, void __user *arg);
130extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
131extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
132
133static inline void ip_rt_put(struct rtable * rt)
134{
135	if (rt)
136		dst_release(&rt->u.dst);
137}
138
139#define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
140
141extern __u8 ip_tos2prio[16];
142
143static inline char rt_tos2priority(u8 tos)
144{
145	return ip_tos2prio[IPTOS_TOS(tos)>>1];
146}
147
148static inline int ip_route_connect(struct rtable **rp, u32 dst,
149				   u32 src, u32 tos, int oif, u8 protocol,
150				   u16 sport, u16 dport, struct sock *sk)
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	return ip_route_output_flow(rp, &fl, sk, 0);
172}
173
174static inline int ip_route_newports(struct rtable **rp, u16 sport, u16 dport,
175				    struct sock *sk)
176{
177	if (sport != (*rp)->fl.fl_ip_sport ||
178	    dport != (*rp)->fl.fl_ip_dport) {
179		struct flowi fl;
180
181		memcpy(&fl, &(*rp)->fl, sizeof(fl));
182		fl.fl_ip_sport = sport;
183		fl.fl_ip_dport = dport;
184		ip_rt_put(*rp);
185		*rp = NULL;
186		return ip_route_output_flow(rp, &fl, sk, 0);
187	}
188	return 0;
189}
190
191extern void rt_bind_peer(struct rtable *rt, int create);
192
193static inline struct inet_peer *rt_get_peer(struct rtable *rt)
194{
195	if (rt->peer)
196		return rt->peer;
197
198	rt_bind_peer(rt, 0);
199	return rt->peer;
200}
201
202#endif	/* _ROUTE_H */
203