route.h revision fb0c5f0bc8b69b40549449ee7fc65f3706f12062 
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 <net/inet_sock.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#include <linux/security.h>
37
38#ifndef __KERNEL__
39#warning This file is not supposed to be used outside of kernel.
40#endif
41
42#define RTO_ONLINK	0x01
43
44#define RTO_CONN	0
45/* RTO_CONN is not used (being alias for 0), but preserved not to break
46 * some modules referring to it. */
47
48#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
49
50struct fib_nh;
51struct inet_peer;
52struct rtable {
53	struct dst_entry	dst;
54
55	/* Cache lookup keys */
56	struct flowi		fl;
57
58	struct in_device	*idev;
59
60	int			rt_genid;
61	unsigned		rt_flags;
62	__u16			rt_type;
63
64	__be32			rt_dst;	/* Path destination	*/
65	__be32			rt_src;	/* Path source		*/
66	int			rt_iif;
67
68	/* Info on neighbour */
69	__be32			rt_gateway;
70
71	/* Miscellaneous cached information */
72	__be32			rt_spec_dst; /* RFC1122 specific destination */
73	struct inet_peer	*peer; /* long-living peer info */
74};
75
76struct ip_rt_acct {
77	__u32 	o_bytes;
78	__u32 	o_packets;
79	__u32 	i_bytes;
80	__u32 	i_packets;
81};
82
83struct rt_cache_stat {
84        unsigned int in_hit;
85        unsigned int in_slow_tot;
86        unsigned int in_slow_mc;
87        unsigned int in_no_route;
88        unsigned int in_brd;
89        unsigned int in_martian_dst;
90        unsigned int in_martian_src;
91        unsigned int out_hit;
92        unsigned int out_slow_tot;
93        unsigned int out_slow_mc;
94        unsigned int gc_total;
95        unsigned int gc_ignored;
96        unsigned int gc_goal_miss;
97        unsigned int gc_dst_overflow;
98        unsigned int in_hlist_search;
99        unsigned int out_hlist_search;
100};
101
102extern struct ip_rt_acct __percpu *ip_rt_acct;
103
104struct in_device;
105extern int		ip_rt_init(void);
106extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
107				       __be32 src, struct net_device *dev);
108extern void		rt_cache_flush(struct net *net, int how);
109extern void		rt_cache_flush_batch(void);
110extern int		__ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp);
111extern int		ip_route_output_key(struct net *, struct rtable **, struct flowi *flp);
112extern int		ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
113
114extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
115				 u8 tos, struct net_device *devin, bool noref);
116
117static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
118				 u8 tos, struct net_device *devin)
119{
120	return ip_route_input_common(skb, dst, src, tos, devin, false);
121}
122
123static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
124				       u8 tos, struct net_device *devin)
125{
126	return ip_route_input_common(skb, dst, src, tos, devin, true);
127}
128
129extern unsigned short	ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
130extern void		ip_rt_send_redirect(struct sk_buff *skb);
131
132extern unsigned		inet_addr_type(struct net *net, __be32 addr);
133extern unsigned		inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
134extern void		ip_rt_multicast_event(struct in_device *);
135extern int		ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
136extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
137extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
138
139struct in_ifaddr;
140extern void fib_add_ifaddr(struct in_ifaddr *);
141
142static inline void ip_rt_put(struct rtable * rt)
143{
144	if (rt)
145		dst_release(&rt->dst);
146}
147
148#define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
149
150extern const __u8 ip_tos2prio[16];
151
152static inline char rt_tos2priority(u8 tos)
153{
154	return ip_tos2prio[IPTOS_TOS(tos)>>1];
155}
156
157static inline int ip_route_connect(struct rtable **rp, __be32 dst,
158				   __be32 src, u32 tos, int oif, u8 protocol,
159				   __be16 sport, __be16 dport, struct sock *sk,
160				   int flags)
161{
162	struct flowi fl = { .oif = oif,
163			    .mark = sk->sk_mark,
164			    .nl_u = { .ip4_u = { .daddr = dst,
165						 .saddr = src,
166						 .tos   = tos } },
167			    .proto = protocol,
168			    .uli_u = { .ports =
169				       { .sport = sport,
170					 .dport = dport } } };
171
172	int err;
173	struct net *net = sock_net(sk);
174
175	if (inet_sk(sk)->transparent)
176		fl.flags |= FLOWI_FLAG_ANYSRC;
177
178	if (!dst || !src) {
179		err = __ip_route_output_key(net, rp, &fl);
180		if (err)
181			return err;
182		fl.fl4_dst = (*rp)->rt_dst;
183		fl.fl4_src = (*rp)->rt_src;
184		ip_rt_put(*rp);
185		*rp = NULL;
186	}
187	security_sk_classify_flow(sk, &fl);
188	return ip_route_output_flow(net, rp, &fl, sk, flags);
189}
190
191static inline int ip_route_newports(struct rtable **rp, u8 protocol,
192				    __be16 sport, __be16 dport, struct sock *sk)
193{
194	if (sport != (*rp)->fl.fl_ip_sport ||
195	    dport != (*rp)->fl.fl_ip_dport) {
196		struct flowi fl;
197
198		memcpy(&fl, &(*rp)->fl, sizeof(fl));
199		fl.fl_ip_sport = sport;
200		fl.fl_ip_dport = dport;
201		fl.proto = protocol;
202		if (inet_sk(sk)->transparent)
203			fl.flags |= FLOWI_FLAG_ANYSRC;
204		ip_rt_put(*rp);
205		*rp = NULL;
206		security_sk_classify_flow(sk, &fl);
207		return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0);
208	}
209	return 0;
210}
211
212extern void rt_bind_peer(struct rtable *rt, int create);
213
214static inline struct inet_peer *rt_get_peer(struct rtable *rt)
215{
216	if (rt->peer)
217		return rt->peer;
218
219	rt_bind_peer(rt, 0);
220	return rt->peer;
221}
222
223static inline int inet_iif(const struct sk_buff *skb)
224{
225	return skb_rtable(skb)->rt_iif;
226}
227
228#endif	/* _ROUTE_H */
229