[mirror_ubuntu-bionic-kernel.git] / include / net / route.h

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET  is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the IP router.
 *
 * Version:	@(#)route.h	1.0.4	05/27/93
 *
 * Authors:	Ross Biro
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 * Fixes:
 *		Alan Cox	:	Reformatted. Added ip_rt_local()
 *		Alan Cox	:	Support for TCP parameters.
 *		Alexey Kuznetsov:	Major changes for new routing code.
 *		Mike McLagan    :	Routing by source
 *		Robert Olsson   :	Added rt_cache statistics
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#ifndef _ROUTE_H
#define _ROUTE_H

#include <net/dst.h>
#include <net/inetpeer.h>
#include <net/flow.h>
#include <net/inet_sock.h>
#include <linux/in_route.h>
#include <linux/rtnetlink.h>
#include <linux/route.h>
#include <linux/ip.h>
#include <linux/cache.h>
#include <linux/security.h>

#define RTO_ONLINK	0x01

#define RTO_CONN	0
/* RTO_CONN is not used (being alias for 0), but preserved not to break
 * some modules referring to it. */

#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))

struct fib_nh;
struct inet_peer;
struct fib_info;
struct rtable {
	struct dst_entry	dst;

	/* Lookup key. */
	__be32			rt_key_dst;
	__be32			rt_key_src;

	int			rt_genid;
	unsigned		rt_flags;
	__u16			rt_type;
	__u8			rt_tos;

	__be32			rt_dst;	/* Path destination	*/
	__be32			rt_src;	/* Path source		*/
	int			rt_route_iif;
	int			rt_iif;
	int			rt_oif;
	__u32			rt_mark;

	/* Info on neighbour */
	__be32			rt_gateway;

	/* Miscellaneous cached information */
	__be32			rt_spec_dst; /* RFC1122 specific destination */
	u32			rt_peer_genid;
	struct inet_peer	*peer; /* long-living peer info */
	struct fib_info		*fi; /* for client ref to shared metrics */
};

static inline bool rt_is_input_route(struct rtable *rt)
{
	return rt->rt_route_iif != 0;
}

static inline bool rt_is_output_route(struct rtable *rt)
{
	return rt->rt_route_iif == 0;
}

struct ip_rt_acct {
	__u32 	o_bytes;
	__u32 	o_packets;
	__u32 	i_bytes;
	__u32 	i_packets;
};

struct rt_cache_stat {
        unsigned int in_hit;
        unsigned int in_slow_tot;
        unsigned int in_slow_mc;
        unsigned int in_no_route;
        unsigned int in_brd;
        unsigned int in_martian_dst;
        unsigned int in_martian_src;
        unsigned int out_hit;
        unsigned int out_slow_tot;
        unsigned int out_slow_mc;
        unsigned int gc_total;
        unsigned int gc_ignored;
        unsigned int gc_goal_miss;
        unsigned int gc_dst_overflow;
        unsigned int in_hlist_search;
        unsigned int out_hlist_search;
};

extern struct ip_rt_acct __percpu *ip_rt_acct;

struct in_device;
extern int		ip_rt_init(void);
extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
				       __be32 src, struct net_device *dev);
extern void		rt_cache_flush(struct net *net, int how);
extern void		rt_cache_flush_batch(struct net *net);
extern struct rtable *__ip_route_output_key(struct net *, const struct flowi4 *flp);
extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
					   struct sock *sk);
extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig);

static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
{
	return ip_route_output_flow(net, flp, NULL);
}

static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
					     __be32 saddr, u8 tos, int oif)
{
	struct flowi4 fl4 = {
		.flowi4_oif = oif,
		.daddr = daddr,
		.saddr = saddr,
		.flowi4_tos = tos,
	};
	return ip_route_output_key(net, &fl4);
}

static inline struct rtable *ip_route_output_ports(struct net *net, struct sock *sk,
						   __be32 daddr, __be32 saddr,
						   __be16 dport, __be16 sport,
						   __u8 proto, __u8 tos, int oif)
{
	struct flowi4 fl4;

	flowi4_init_output(&fl4, oif, sk ? sk->sk_mark : 0, tos,
			   RT_SCOPE_UNIVERSE, proto,
			   sk ? inet_sk_flowi_flags(sk) : 0,
			   daddr, saddr, dport, sport);
	if (sk)
		security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
	return ip_route_output_flow(net, &fl4, sk);
}

static inline struct rtable *ip_route_output_gre(struct net *net,
						 __be32 daddr, __be32 saddr,
						 __be32 gre_key, __u8 tos, int oif)
{
	struct flowi4 fl4 = {
		.flowi4_oif = oif,
		.daddr = daddr,
		.saddr = saddr,
		.flowi4_tos = tos,
		.flowi4_proto = IPPROTO_GRE,
		.fl4_gre_key = gre_key,
	};
	return ip_route_output_key(net, &fl4);
}

extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
				 u8 tos, struct net_device *devin, bool noref);

static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
				 u8 tos, struct net_device *devin)
{
	return ip_route_input_common(skb, dst, src, tos, devin, false);
}

static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
				       u8 tos, struct net_device *devin)
{
	return ip_route_input_common(skb, dst, src, tos, devin, true);
}

extern unsigned short	ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
					  unsigned short new_mtu, struct net_device *dev);
extern void		ip_rt_send_redirect(struct sk_buff *skb);

extern unsigned		inet_addr_type(struct net *net, __be32 addr);
extern unsigned		inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
extern void		ip_rt_multicast_event(struct in_device *);
extern int		ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
extern void		ip_rt_get_source(u8 *src, struct rtable *rt);
extern int		ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);

struct in_ifaddr;
extern void fib_add_ifaddr(struct in_ifaddr *);
extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);

static inline void ip_rt_put(struct rtable * rt)
{
	if (rt)
		dst_release(&rt->dst);
}

#define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)

extern const __u8 ip_tos2prio[16];

static inline char rt_tos2priority(u8 tos)
{
	return ip_tos2prio[IPTOS_TOS(tos)>>1];
}

static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
					      int oif, u8 protocol,
					      __be16 sport, __be16 dport,
					      struct sock *sk, bool can_sleep)
{
	struct net *net = sock_net(sk);
	struct rtable *rt;
	struct flowi4 fl4;
	__u8 flow_flags;

	flow_flags = 0;
	if (inet_sk(sk)->transparent)
		flow_flags |= FLOWI_FLAG_ANYSRC;
	if (protocol == IPPROTO_TCP)
		flow_flags |= FLOWI_FLAG_PRECOW_METRICS;
	if (can_sleep)
		flow_flags |= FLOWI_FLAG_CAN_SLEEP;

	flowi4_init_output(&fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
			   protocol, flow_flags, dst, src, dport, sport);

	if (!dst || !src) {
		rt = __ip_route_output_key(net, &fl4);
		if (IS_ERR(rt))
			return rt;
		fl4.daddr = rt->rt_dst;
		fl4.saddr = rt->rt_src;
		ip_rt_put(rt);
	}
	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
	return ip_route_output_flow(net, &fl4, sk);
}

static inline struct rtable *ip_route_newports(struct rtable *rt,
					       u8 protocol, __be16 orig_sport,
					       __be16 orig_dport, __be16 sport,
					       __be16 dport, struct sock *sk)
{
	if (sport != orig_sport || dport != orig_dport) {
		struct flowi4 fl4;
		__u8 flow_flags;

		flow_flags = 0;
		if (inet_sk(sk)->transparent)
			flow_flags |= FLOWI_FLAG_ANYSRC;
		if (protocol == IPPROTO_TCP)
			flow_flags |= FLOWI_FLAG_PRECOW_METRICS;
		flowi4_init_output(&fl4, rt->rt_oif, rt->rt_mark, rt->rt_tos,
				   RT_SCOPE_UNIVERSE, protocol, flow_flags,
				   rt->rt_dst, rt->rt_src, dport, sport);
		ip_rt_put(rt);
		security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
		return ip_route_output_flow(sock_net(sk), &fl4, sk);
	}
	return rt;
}

extern void rt_bind_peer(struct rtable *rt, int create);

static inline struct inet_peer *rt_get_peer(struct rtable *rt)
{
	if (rt->peer)
		return rt->peer;

	rt_bind_peer(rt, 0);
	return rt->peer;
}

static inline int inet_iif(const struct sk_buff *skb)
{
	return skb_rtable(skb)->rt_iif;
}

extern int sysctl_ip_default_ttl;

static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
{
	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);

	if (hoplimit == 0)
		hoplimit = sysctl_ip_default_ttl;
	return hoplimit;
}

#endif	/* _ROUTE_H */
Commit	Line	Data
1da177e4 LT	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	*
02c30a84	10	* Authors: Ross Biro
1da177e4 LT	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
1da177e4 LT	27	#include <net/dst.h>
	28	#include <net/inetpeer.h>
	29	#include <net/flow.h>
79876874	30	#include <net/inet_sock.h>
1da177e4 LT	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>
beb8d13b	36	#include <linux/security.h>
1da177e4	37
1da177e4 LT	38	#define RTO_ONLINK 0x01
	39
	40	#define RTO_CONN 0
	41	/* RTO_CONN is not used (being alias for 0), but preserved not to break
	42	* some modules referring to it. */
	43
	44	#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) \| sock_flag(sk, SOCK_LOCALROUTE))
	45
	46	struct fib_nh;
	47	struct inet_peer;
62fa8a84	48	struct fib_info;
fd2c3ef7	49	struct rtable {
d8d1f30b	50	struct dst_entry dst;
1da177e4	51
5e2b61f7 DM	52	/* Lookup key. */
	53	__be32 rt_key_dst;
	54	__be32 rt_key_src;
093c2ca4	55
29e75252	56	int rt_genid;
1da177e4 LT	57	unsigned rt_flags;
1da177e4 LT	58	__u16 rt_type;
5e2b61f7	59	__u8 rt_tos;
1da177e4	60
f2c3fe24 AV	61	__be32 rt_dst; /* Path destination */
f2c3fe24 AV	62	__be32 rt_src; /* Path source */
1b86a58f	63	int rt_route_iif;
1da177e4	64	int rt_iif;
5e2b61f7 DM	65	int rt_oif;
5e2b61f7 DM	66	__u32 rt_mark;
1da177e4 LT	67
1da177e4 LT	68	/* Info on neighbour */
f2c3fe24	69	__be32 rt_gateway;
1da177e4	70
1da177e4	71	/* Miscellaneous cached information */
f2c3fe24	72	__be32 rt_spec_dst; /* RFC1122 specific destination */
6431cbc2	73	u32 rt_peer_genid;
1da177e4	74	struct inet_peer peer; / long-living peer info */
62fa8a84	75	struct fib_info fi; / for client ref to shared metrics */
1da177e4 LT	76	};
1da177e4 LT	77
c7537967 DM	78	static inline bool rt_is_input_route(struct rtable *rt)
c7537967 DM	79	{
1b86a58f	80	return rt->rt_route_iif != 0;
c7537967 DM	81	}
	82
	83	static inline bool rt_is_output_route(struct rtable *rt)
	84	{
1b86a58f	85	return rt->rt_route_iif == 0;
c7537967 DM	86	}
c7537967 DM	87
fd2c3ef7	88	struct ip_rt_acct {
1da177e4 LT	89	__u32 o_bytes;
	90	__u32 o_packets;
	91	__u32 i_bytes;
	92	__u32 i_packets;
	93	};
	94
fd2c3ef7	95	struct rt_cache_stat {
1da177e4 LT	96	unsigned int in_hit;
	97	unsigned int in_slow_tot;
	98	unsigned int in_slow_mc;
	99	unsigned int in_no_route;
	100	unsigned int in_brd;
	101	unsigned int in_martian_dst;
	102	unsigned int in_martian_src;
	103	unsigned int out_hit;
	104	unsigned int out_slow_tot;
	105	unsigned int out_slow_mc;
	106	unsigned int gc_total;
	107	unsigned int gc_ignored;
	108	unsigned int gc_goal_miss;
	109	unsigned int gc_dst_overflow;
	110	unsigned int in_hlist_search;
	111	unsigned int out_hlist_search;
	112	};
	113
7d720c3e	114	extern struct ip_rt_acct __percpu *ip_rt_acct;
1da177e4 LT	115
	116	struct in_device;
	117	extern int ip_rt_init(void);
f7655229 AV	118	extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
f7655229 AV	119	__be32 src, struct net_device *dev);
76e6ebfb	120	extern void rt_cache_flush(struct net *net, int how);
6561a3b1	121	extern void rt_cache_flush_batch(struct net *net);
9d6ec938 DM	122	extern struct rtable __ip_route_output_key(struct net , const struct flowi4 *flp);
9d6ec938 DM	123	extern struct rtable ip_route_output_flow(struct net , struct flowi4 *flp,
b23dd4fe	124	struct sock *sk);
2774c131	125	extern struct dst_entry ipv4_blackhole_route(struct net net, struct dst_entry *dst_orig);
407eadd9	126
9d6ec938	127	static inline struct rtable ip_route_output_key(struct net net, struct flowi4 *flp)
5bfa787f DM	128	{
	129	return ip_route_output_flow(net, flp, NULL);
	130	}
	131
78fbfd8a DM	132	static inline struct rtable ip_route_output(struct net net, __be32 daddr,
	133	__be32 saddr, u8 tos, int oif)
	134	{
9d6ec938 DM	135	struct flowi4 fl4 = {
	136	.flowi4_oif = oif,
	137	.daddr = daddr,
	138	.saddr = saddr,
	139	.flowi4_tos = tos,
78fbfd8a	140	};
9d6ec938	141	return ip_route_output_key(net, &fl4);
78fbfd8a DM	142	}
	143
	144	static inline struct rtable ip_route_output_ports(struct net net, struct sock *sk,
	145	__be32 daddr, __be32 saddr,
	146	__be16 dport, __be16 sport,
	147	__u8 proto, __u8 tos, int oif)
	148	{
94b92b88 DM	149	struct flowi4 fl4;
	150
	151	flowi4_init_output(&fl4, oif, sk ? sk->sk_mark : 0, tos,
	152	RT_SCOPE_UNIVERSE, proto,
	153	sk ? inet_sk_flowi_flags(sk) : 0,
	154	daddr, saddr, dport, sport);
78fbfd8a	155	if (sk)
9d6ec938 DM	156	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
9d6ec938 DM	157	return ip_route_output_flow(net, &fl4, sk);
78fbfd8a DM	158	}
	159
	160	static inline struct rtable ip_route_output_gre(struct net net,
	161	__be32 daddr, __be32 saddr,
	162	__be32 gre_key, __u8 tos, int oif)
	163	{
9d6ec938 DM	164	struct flowi4 fl4 = {
	165	.flowi4_oif = oif,
	166	.daddr = daddr,
	167	.saddr = saddr,
	168	.flowi4_tos = tos,
	169	.flowi4_proto = IPPROTO_GRE,
9cce96df	170	.fl4_gre_key = gre_key,
78fbfd8a	171	};
9d6ec938	172	return ip_route_output_key(net, &fl4);
78fbfd8a DM	173	}
78fbfd8a DM	174
407eadd9 ED	175	extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
	176	u8 tos, struct net_device *devin, bool noref);
	177
	178	static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
	179	u8 tos, struct net_device *devin)
	180	{
	181	return ip_route_input_common(skb, dst, src, tos, devin, false);
	182	}
	183
	184	static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
	185	u8 tos, struct net_device *devin)
	186	{
	187	return ip_route_input_common(skb, dst, src, tos, devin, true);
	188	}
	189
b71d1d42 ED	190	extern unsigned short ip_rt_frag_needed(struct net net, const struct iphdr iph,
b71d1d42 ED	191	unsigned short new_mtu, struct net_device *dev);
1da177e4 LT	192	extern void ip_rt_send_redirect(struct sk_buff *skb);
1da177e4 LT	193
6b175b26 EB	194	extern unsigned inet_addr_type(struct net *net, __be32 addr);
6b175b26 EB	195	extern unsigned inet_dev_addr_type(struct net net, const struct net_device dev, __be32 addr);
1da177e4	196	extern void ip_rt_multicast_event(struct in_device *);
1bad118a	197	extern int ip_rt_ioctl(struct net , unsigned int cmd, void __user arg);
1da177e4 LT	198	extern void ip_rt_get_source(u8 src, struct rtable rt);
	199	extern int ip_rt_dump(struct sk_buff skb, struct netlink_callback cb);
	200
0ff60a45 JHS	201	struct in_ifaddr;
0ff60a45 JHS	202	extern void fib_add_ifaddr(struct in_ifaddr *);
e6abbaa2	203	extern void fib_del_ifaddr(struct in_ifaddr , struct in_ifaddr );
0ff60a45	204
1da177e4 LT	205	static inline void ip_rt_put(struct rtable * rt)
	206	{
	207	if (rt)
d8d1f30b	208	dst_release(&rt->dst);
1da177e4 LT	209	}
	210
	211	#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
	212
4839c52b	213	extern const __u8 ip_tos2prio[16];
1da177e4 LT	214
	215	static inline char rt_tos2priority(u8 tos)
	216	{
	217	return ip_tos2prio[IPTOS_TOS(tos)>>1];
	218	}
	219
b23dd4fe DM	220	static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
	221	int oif, u8 protocol,
	222	__be16 sport, __be16 dport,
	223	struct sock *sk, bool can_sleep)
1da177e4	224	{
3b1e0a65	225	struct net *net = sock_net(sk);
b23dd4fe	226	struct rtable *rt;
94b92b88 DM	227	struct flowi4 fl4;
94b92b88 DM	228	__u8 flow_flags;
79876874	229
94b92b88	230	flow_flags = 0;
79876874	231	if (inet_sk(sk)->transparent)
94b92b88	232	flow_flags \|= FLOWI_FLAG_ANYSRC;
a4daad6b	233	if (protocol == IPPROTO_TCP)
94b92b88	234	flow_flags \|= FLOWI_FLAG_PRECOW_METRICS;
5df65e55	235	if (can_sleep)
94b92b88 DM	236	flow_flags \|= FLOWI_FLAG_CAN_SLEEP;
	237
	238	flowi4_init_output(&fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
	239	protocol, flow_flags, dst, src, dport, sport);
79876874	240
1da177e4	241	if (!dst \|\| !src) {
9d6ec938	242	rt = __ip_route_output_key(net, &fl4);
b23dd4fe DM	243	if (IS_ERR(rt))
b23dd4fe DM	244	return rt;
9d6ec938 DM	245	fl4.daddr = rt->rt_dst;
9d6ec938 DM	246	fl4.saddr = rt->rt_src;
b23dd4fe	247	ip_rt_put(rt);
1da177e4	248	}
9d6ec938 DM	249	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
9d6ec938 DM	250	return ip_route_output_flow(net, &fl4, sk);
1da177e4 LT	251	}
1da177e4 LT	252
b23dd4fe DM	253	static inline struct rtable ip_route_newports(struct rtable rt,
	254	u8 protocol, __be16 orig_sport,
	255	__be16 orig_dport, __be16 sport,
	256	__be16 dport, struct sock *sk)
1da177e4	257	{
dca8b089	258	if (sport != orig_sport \|\| dport != orig_dport) {
94b92b88 DM	259	struct flowi4 fl4;
	260	__u8 flow_flags;
	261
	262	flow_flags = 0;
fb0c5f0b	263	if (inet_sk(sk)->transparent)
94b92b88	264	flow_flags \|= FLOWI_FLAG_ANYSRC;
a4daad6b	265	if (protocol == IPPROTO_TCP)
94b92b88 DM	266	flow_flags \|= FLOWI_FLAG_PRECOW_METRICS;
	267	flowi4_init_output(&fl4, rt->rt_oif, rt->rt_mark, rt->rt_tos,
	268	RT_SCOPE_UNIVERSE, protocol, flow_flags,
	269	rt->rt_dst, rt->rt_src, dport, sport);
b23dd4fe	270	ip_rt_put(rt);
9d6ec938 DM	271	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
9d6ec938 DM	272	return ip_route_output_flow(sock_net(sk), &fl4, sk);
1da177e4	273	}
b23dd4fe	274	return rt;
1da177e4 LT	275	}
	276
	277	extern void rt_bind_peer(struct rtable *rt, int create);
	278
	279	static inline struct inet_peer rt_get_peer(struct rtable rt)
	280	{
	281	if (rt->peer)
	282	return rt->peer;
	283
	284	rt_bind_peer(rt, 0);
	285	return rt->peer;
	286	}
	287
1668e010 KK	288	static inline int inet_iif(const struct sk_buff *skb)
1668e010 KK	289	{
511c3f92	290	return skb_rtable(skb)->rt_iif;
1668e010 KK	291	}
1668e010 KK	292
323e126f DM	293	extern int sysctl_ip_default_ttl;
	294
	295	static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
	296	{
	297	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
	298
	299	if (hoplimit == 0)
	300	hoplimit = sysctl_ip_default_ttl;
	301	return hoplimit;
	302	}
	303
1da177e4	304	#endif /* _ROUTE_H */