route.h revision 39dccd9d922b595301e5d43ca7a30823d81393b6 
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
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	__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
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 ip_rt_acct *ip_rt_acct;
109
110struct in_device;
111extern int		ip_rt_init(void);
112extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
113				       __be32 src, struct net_device *dev);
114extern void		ip_rt_advice(struct rtable **rp, int advice);
115extern void		rt_cache_flush(int how);
116extern int		__ip_route_output_key(struct rtable **, const struct flowi *flp);
117extern int		ip_route_output_key(struct rtable **, struct flowi *flp);
118extern int		ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
119extern int		ip_route_input(struct sk_buff*, __be32 dst, __be32 src, u8 tos, struct net_device *devin);
120extern unsigned short	ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
121extern void		ip_rt_send_redirect(struct sk_buff *skb);
122
123extern unsigned		inet_addr_type(__be32 addr);
124extern void		ip_rt_multicast_event(struct in_device *);
125extern int		ip_rt_ioctl(unsigned int cmd, void __user *arg);
126extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
127extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
128
129struct in_ifaddr;
130extern void fib_add_ifaddr(struct in_ifaddr *);
131
132static 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
140extern __u8 ip_tos2prio[16];
141
142static inline char rt_tos2priority(u8 tos)
143{
144	return ip_tos2prio[IPTOS_TOS(tos)>>1];
145}
146
147static 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{
151	struct flowi fl = { .oif = oif,
152			    .nl_u = { .ip4_u = { .daddr = dst,
153						 .saddr = src,
154						 .tos   = tos } },
155			    .proto = protocol,
156			    .uli_u = { .ports =
157				       { .sport = sport,
158					 .dport = dport } } };
159
160	int err;
161	if (!dst || !src) {
162		err = __ip_route_output_key(rp, &fl);
163		if (err)
164			return err;
165		fl.fl4_dst = (*rp)->rt_dst;
166		fl.fl4_src = (*rp)->rt_src;
167		ip_rt_put(*rp);
168		*rp = NULL;
169	}
170	security_sk_classify_flow(sk, &fl);
171	return ip_route_output_flow(rp, &fl, sk, 0);
172}
173
174static inline int ip_route_newports(struct rtable **rp, u8 protocol,
175				    __be16 sport, __be16 dport, 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		fl.proto = protocol;
185		ip_rt_put(*rp);
186		*rp = NULL;
187		security_sk_classify_flow(sk, &fl);
188		return ip_route_output_flow(rp, &fl, sk, 0);
189	}
190	return 0;
191}
192
193extern void rt_bind_peer(struct rtable *rt, int create);
194
195static inline struct inet_peer *rt_get_peer(struct rtable *rt)
196{
197	if (rt->peer)
198		return rt->peer;
199
200	rt_bind_peer(rt, 0);
201	return rt->peer;
202}
203
204extern ctl_table ipv4_route_table[];
205
206#endif	/* _ROUTE_H */
207