[mirror_ubuntu-artful-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 <net/ip_fib.h>
#include <linux/in_route.h>
#include <linux/rtnetlink.h>
#include <linux/rcupdate.h>
#include <linux/route.h>
#include <linux/ip.h>
#include <linux/cache.h>
#include <linux/security.h>

/* IPv4 datagram length is stored into 16bit field (tot_len) */
#define IP_MAX_MTU	0xFFFFU

#define RTO_ONLINK	0x01

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

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

	int			rt_genid;
	unsigned int		rt_flags;
	__u16			rt_type;
	__u8			rt_is_input;
	__u8			rt_uses_gateway;

	int			rt_iif;

	/* Info on neighbour */
	__be32			rt_gateway;

	/* Miscellaneous cached information */
	u32			rt_pmtu;

	u32			rt_table_id;

	struct list_head	rt_uncached;
	struct uncached_list	*rt_uncached_list;
};

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

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

static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
{
	if (rt->rt_gateway)
		return rt->rt_gateway;
	return daddr;
}

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

struct rt_cache_stat {
        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_slow_tot;
        unsigned int out_slow_mc;
};

extern struct ip_rt_acct __percpu *ip_rt_acct;

struct in_device;

int ip_rt_init(void);
void rt_cache_flush(struct net *net);
void rt_flush_dev(struct net_device *dev);
struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
					const struct sk_buff *skb);
struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
					    struct fib_result *res,
					    const struct sk_buff *skb);

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

struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
				    const struct sock *sk);
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,
		.flowi4_tos = tos,
		.daddr = daddr,
		.saddr = saddr,
	};
	return ip_route_output_key(net, &fl4);
}

static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
						   struct sock *sk,
						   __be32 daddr, __be32 saddr,
						   __be16 dport, __be16 sport,
						   __u8 proto, __u8 tos, int oif)
{
	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, sock_net_uid(net, sk));
	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, struct flowi4 *fl4,
						 __be32 daddr, __be32 saddr,
						 __be32 gre_key, __u8 tos, int oif)
{
	memset(fl4, 0, sizeof(*fl4));
	fl4->flowi4_oif = oif;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
	fl4->flowi4_tos = tos;
	fl4->flowi4_proto = IPPROTO_GRE;
	fl4->fl4_gre_key = gre_key;
	return ip_route_output_key(net, fl4);
}
int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
			  u8 tos, struct net_device *dev,
			  struct in_device *in_dev, u32 *itag);
int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
			 u8 tos, struct net_device *devin);
int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
		       u8 tos, struct net_device *devin,
		       struct fib_result *res);

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

	rcu_read_lock();
	err = ip_route_input_noref(skb, dst, src, tos, devin);
	if (!err)
		skb_dst_force_safe(skb);
	if (!skb_dst(skb))
		err = -EINVAL;
	rcu_read_unlock();

	return err;
}

void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
		      u32 mark, u8 protocol, int flow_flags);
void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
		   u8 protocol, int flow_flags);
void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
void ip_rt_send_redirect(struct sk_buff *skb);

unsigned int inet_addr_type(struct net *net, __be32 addr);
unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
				__be32 addr);
unsigned int inet_addr_type_dev_table(struct net *net,
				      const struct net_device *dev,
				      __be32 addr);
void ip_rt_multicast_event(struct in_device *);
int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
struct rtable *rt_dst_alloc(struct net_device *dev,
			     unsigned int flags, u16 type,
			     bool nopolicy, bool noxfrm, bool will_cache);

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

static inline void ip_rt_put(struct rtable *rt)
{
	/* dst_release() accepts a NULL parameter.
	 * We rely on dst being first structure in struct rtable
	 */
	BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
	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];
}

/* ip_route_connect() and ip_route_newports() work in tandem whilst
 * binding a socket for a new outgoing connection.
 *
 * In order to use IPSEC properly, we must, in the end, have a
 * route that was looked up using all available keys including source
 * and destination ports.
 *
 * However, if a source port needs to be allocated (the user specified
 * a wildcard source port) we need to obtain addressing information
 * in order to perform that allocation.
 *
 * So ip_route_connect() looks up a route using wildcarded source and
 * destination ports in the key, simply so that we can get a pair of
 * addresses to use for port allocation.
 *
 * Later, once the ports are allocated, ip_route_newports() will make
 * another route lookup if needed to make sure we catch any IPSEC
 * rules keyed on the port information.
 *
 * The callers allocate the flow key on their stack, and must pass in
 * the same flowi4 object to both the ip_route_connect() and the
 * ip_route_newports() calls.
 */

static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
					 u32 tos, int oif, u8 protocol,
					 __be16 sport, __be16 dport,
					 struct sock *sk)
{
	__u8 flow_flags = 0;

	if (inet_sk(sk)->transparent)
		flow_flags |= FLOWI_FLAG_ANYSRC;

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

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

	ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
			      sport, dport, sk);

	if (!dst || !src) {
		rt = __ip_route_output_key(net, fl4);
		if (IS_ERR(rt))
			return rt;
		ip_rt_put(rt);
		flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
	}
	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 flowi4 *fl4, struct rtable *rt,
					       __be16 orig_sport, __be16 orig_dport,
					       __be16 sport, __be16 dport,
					       struct sock *sk)
{
	if (sport != orig_sport || dport != orig_dport) {
		fl4->fl4_dport = dport;
		fl4->fl4_sport = sport;
		ip_rt_put(rt);
		flowi4_update_output(fl4, sk->sk_bound_dev_if,
				     RT_CONN_FLAGS(sk), fl4->daddr,
				     fl4->saddr);
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		return ip_route_output_flow(sock_net(sk), fl4, sk);
	}
	return rt;
}

static inline int inet_iif(const struct sk_buff *skb)
{
	struct rtable *rt = skb_rtable(skb);

	if (rt && rt->rt_iif)
		return rt->rt_iif;

	return skb->skb_iif;
}

static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
{
	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
	struct net *net = dev_net(dst->dev);

	if (hoplimit == 0)
		hoplimit = net->ipv4.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>
79a13159	31	#include <net/ip_fib.h>
1da177e4 LT	32	#include <linux/in_route.h>
1da177e4 LT	33	#include <linux/rtnetlink.h>
c6cffba4	34	#include <linux/rcupdate.h>
1da177e4 LT	35	#include <linux/route.h>
	36	#include <linux/ip.h>
	37	#include <linux/cache.h>
beb8d13b	38	#include <linux/security.h>
1da177e4	39
f87c10a8 HFS	40	/* IPv4 datagram length is stored into 16bit field (tot_len) */
	41	#define IP_MAX_MTU 0xFFFFU
	42
1da177e4 LT	43	#define RTO_ONLINK 0x01
1da177e4 LT	44
1da177e4	45	#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) \| sock_flag(sk, SOCK_LOCALROUTE))
aa661581	46	#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) \| sock_flag(sk, SOCK_LOCALROUTE))
1da177e4 LT	47
1da177e4 LT	48	struct fib_nh;
62fa8a84	49	struct fib_info;
5055c371	50	struct uncached_list;
fd2c3ef7	51	struct rtable {
d8d1f30b	52	struct dst_entry dst;
1da177e4	53
29e75252	54	int rt_genid;
95c96174	55	unsigned int rt_flags;
1da177e4	56	__u16 rt_type;
155e8336 JA	57	__u8 rt_is_input;
155e8336 JA	58	__u8 rt_uses_gateway;
1da177e4	59
1da177e4 LT	60	int rt_iif;
	61
	62	/* Info on neighbour */
f2c3fe24	63	__be32 rt_gateway;
1da177e4	64
1da177e4	65	/* Miscellaneous cached information */
5943634f	66	u32 rt_pmtu;
caacf05e	67
b7503e0c DA	68	u32 rt_table_id;
b7503e0c DA	69
caacf05e	70	struct list_head rt_uncached;
5055c371	71	struct uncached_list *rt_uncached_list;
1da177e4 LT	72	};
1da177e4 LT	73
b8400f37	74	static inline bool rt_is_input_route(const struct rtable *rt)
c7537967	75	{
9917e1e8	76	return rt->rt_is_input != 0;
c7537967 DM	77	}
c7537967 DM	78
b8400f37	79	static inline bool rt_is_output_route(const struct rtable *rt)
c7537967	80	{
9917e1e8	81	return rt->rt_is_input == 0;
c7537967 DM	82	}
c7537967 DM	83
f8126f1d DM	84	static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
	85	{
	86	if (rt->rt_gateway)
	87	return rt->rt_gateway;
	88	return daddr;
	89	}
	90
fd2c3ef7	91	struct ip_rt_acct {
1da177e4 LT	92	__u32 o_bytes;
	93	__u32 o_packets;
	94	__u32 i_bytes;
	95	__u32 i_packets;
	96	};
	97
fd2c3ef7	98	struct rt_cache_stat {
1da177e4 LT	99	unsigned int in_slow_tot;
	100	unsigned int in_slow_mc;
	101	unsigned int in_no_route;
	102	unsigned int in_brd;
	103	unsigned int in_martian_dst;
	104	unsigned int in_martian_src;
1da177e4 LT	105	unsigned int out_slow_tot;
1da177e4 LT	106	unsigned int out_slow_mc;
1da177e4 LT	107	};
1da177e4 LT	108
7d720c3e	109	extern struct ip_rt_acct __percpu *ip_rt_acct;
1da177e4 LT	110
1da177e4 LT	111	struct in_device;
2702c4bb JP	112
	113	int ip_rt_init(void);
	114	void rt_cache_flush(struct net *net);
	115	void rt_flush_dev(struct net_device *dev);
3abd1ade DA	116	struct rtable ip_route_output_key_hash(struct net net, struct flowi4 *flp,
	117	const struct sk_buff *skb);
	118	struct rtable ip_route_output_key_hash_rcu(struct net net, struct flowi4 *flp,
	119	struct fib_result *res,
	120	const struct sk_buff *skb);
79a13159 PN	121
	122	static inline struct rtable __ip_route_output_key(struct net net,
	123	struct flowi4 *flp)
	124	{
3abd1ade	125	return ip_route_output_key_hash(net, flp, NULL);
79a13159 PN	126	}
79a13159 PN	127
2702c4bb	128	struct rtable ip_route_output_flow(struct net , struct flowi4 *flp,
6f9c9615	129	const struct sock *sk);
2702c4bb JP	130	struct dst_entry ipv4_blackhole_route(struct net net,
2702c4bb JP	131	struct dst_entry *dst_orig);
407eadd9	132
9d6ec938	133	static inline struct rtable ip_route_output_key(struct net net, struct flowi4 *flp)
5bfa787f DM	134	{
	135	return ip_route_output_flow(net, flp, NULL);
	136	}
	137
78fbfd8a DM	138	static inline struct rtable ip_route_output(struct net net, __be32 daddr,
	139	__be32 saddr, u8 tos, int oif)
	140	{
9d6ec938 DM	141	struct flowi4 fl4 = {
9d6ec938 DM	142	.flowi4_oif = oif,
c5d21c4b	143	.flowi4_tos = tos,
9d6ec938 DM	144	.daddr = daddr,
9d6ec938 DM	145	.saddr = saddr,
78fbfd8a	146	};
9d6ec938	147	return ip_route_output_key(net, &fl4);
78fbfd8a DM	148	}
78fbfd8a DM	149
31e4543d DM	150	static inline struct rtable ip_route_output_ports(struct net net, struct flowi4 *fl4,
31e4543d DM	151	struct sock *sk,
78fbfd8a DM	152	__be32 daddr, __be32 saddr,
	153	__be16 dport, __be16 sport,
	154	__u8 proto, __u8 tos, int oif)
	155	{
31e4543d	156	flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos,
94b92b88 DM	157	RT_SCOPE_UNIVERSE, proto,
94b92b88 DM	158	sk ? inet_sk_flowi_flags(sk) : 0,
e2d118a1	159	daddr, saddr, dport, sport, sock_net_uid(net, sk));
78fbfd8a	160	if (sk)
31e4543d DM	161	security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
31e4543d DM	162	return ip_route_output_flow(net, fl4, sk);
78fbfd8a DM	163	}
78fbfd8a DM	164
cbb1e85f	165	static inline struct rtable ip_route_output_gre(struct net net, struct flowi4 *fl4,
78fbfd8a DM	166	__be32 daddr, __be32 saddr,
	167	__be32 gre_key, __u8 tos, int oif)
	168	{
cbb1e85f DM	169	memset(fl4, 0, sizeof(*fl4));
	170	fl4->flowi4_oif = oif;
	171	fl4->daddr = daddr;
	172	fl4->saddr = saddr;
	173	fl4->flowi4_tos = tos;
	174	fl4->flowi4_proto = IPPROTO_GRE;
	175	fl4->fl4_gre_key = gre_key;
	176	return ip_route_output_key(net, fl4);
78fbfd8a	177	}
3b6ff83a PA	178	int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
	179	u8 tos, struct net_device *dev,
	180	struct in_device in_dev, u32 itag);
2702c4bb JP	181	int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
2702c4bb JP	182	u8 tos, struct net_device *devin);
5510cdf7 DA	183	int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
	184	u8 tos, struct net_device *devin,
	185	struct fib_result *res);
c6cffba4 DM	186
	187	static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
	188	u8 tos, struct net_device *devin)
	189	{
	190	int err;
	191
	192	rcu_read_lock();
	193	err = ip_route_input_noref(skb, dst, src, tos, devin);
	194	if (!err)
9df16efa WW	195	skb_dst_force_safe(skb);
	196	if (!skb_dst(skb))
	197	err = -EINVAL;
c6cffba4 DM	198	rcu_read_unlock();
	199
	200	return err;
	201	}
407eadd9	202
2702c4bb JP	203	void ipv4_update_pmtu(struct sk_buff skb, struct net net, u32 mtu, int oif,
	204	u32 mark, u8 protocol, int flow_flags);
	205	void ipv4_sk_update_pmtu(struct sk_buff skb, struct sock sk, u32 mtu);
	206	void ipv4_redirect(struct sk_buff skb, struct net net, int oif, u32 mark,
	207	u8 protocol, int flow_flags);
	208	void ipv4_sk_redirect(struct sk_buff skb, struct sock sk);
	209	void ip_rt_send_redirect(struct sk_buff *skb);
	210
	211	unsigned int inet_addr_type(struct net *net, __be32 addr);
9b8ff518	212	unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
2702c4bb JP	213	unsigned int inet_dev_addr_type(struct net net, const struct net_device dev,
2702c4bb JP	214	__be32 addr);
30bbaa19 DA	215	unsigned int inet_addr_type_dev_table(struct net *net,
	216	const struct net_device *dev,
	217	__be32 addr);
2702c4bb JP	218	void ip_rt_multicast_event(struct in_device *);
	219	int ip_rt_ioctl(struct net , unsigned int cmd, void __user arg);
	220	void ip_rt_get_source(u8 src, struct sk_buff skb, struct rtable *rt);
9ab179d8 DA	221	struct rtable rt_dst_alloc(struct net_device dev,
	222	unsigned int flags, u16 type,
	223	bool nopolicy, bool noxfrm, bool will_cache);
1da177e4	224
0ff60a45	225	struct in_ifaddr;
2702c4bb JP	226	void fib_add_ifaddr(struct in_ifaddr *);
2702c4bb JP	227	void fib_del_ifaddr(struct in_ifaddr , struct in_ifaddr );
0ff60a45	228
6da025fa	229	static inline void ip_rt_put(struct rtable *rt)
1da177e4	230	{
6da025fa ED	231	/* dst_release() accepts a NULL parameter.
	232	* We rely on dst being first structure in struct rtable
	233	*/
	234	BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
	235	dst_release(&rt->dst);
1da177e4 LT	236	}
	237
	238	#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
	239
4839c52b	240	extern const __u8 ip_tos2prio[16];
1da177e4 LT	241
	242	static inline char rt_tos2priority(u8 tos)
	243	{
	244	return ip_tos2prio[IPTOS_TOS(tos)>>1];
	245	}
	246
2d7192d6 DM	247	/* ip_route_connect() and ip_route_newports() work in tandem whilst
	248	* binding a socket for a new outgoing connection.
	249	*
	250	* In order to use IPSEC properly, we must, in the end, have a
	251	* route that was looked up using all available keys including source
	252	* and destination ports.
	253	*
	254	* However, if a source port needs to be allocated (the user specified
	255	* a wildcard source port) we need to obtain addressing information
	256	* in order to perform that allocation.
	257	*
	258	* So ip_route_connect() looks up a route using wildcarded source and
	259	* destination ports in the key, simply so that we can get a pair of
	260	* addresses to use for port allocation.
	261	*
	262	* Later, once the ports are allocated, ip_route_newports() will make
	263	* another route lookup if needed to make sure we catch any IPSEC
	264	* rules keyed on the port information.
	265	*
	266	* The callers allocate the flow key on their stack, and must pass in
	267	* the same flowi4 object to both the ip_route_connect() and the
	268	* ip_route_newports() calls.
	269	*/
	270
	271	static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
	272	u32 tos, int oif, u8 protocol,
	273	__be16 sport, __be16 dport,
0e0d44ab	274	struct sock *sk)
1da177e4	275	{
2d7192d6	276	__u8 flow_flags = 0;
79876874 KK	277
79876874 KK	278	if (inet_sk(sk)->transparent)
94b92b88	279	flow_flags \|= FLOWI_FLAG_ANYSRC;
94b92b88	280
2d7192d6	281	flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
e2d118a1 LC	282	protocol, flow_flags, dst, src, dport, sport,
e2d118a1 LC	283	sk->sk_uid);
2d7192d6 DM	284	}
	285
	286	static inline struct rtable ip_route_connect(struct flowi4 fl4,
	287	__be32 dst, __be32 src, u32 tos,
	288	int oif, u8 protocol,
	289	__be16 sport, __be16 dport,
0e0d44ab	290	struct sock *sk)
2d7192d6 DM	291	{
	292	struct net *net = sock_net(sk);
	293	struct rtable *rt;
	294
	295	ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
0e0d44ab	296	sport, dport, sk);
79876874	297
1da177e4	298	if (!dst \|\| !src) {
2d7192d6	299	rt = __ip_route_output_key(net, fl4);
b23dd4fe DM	300	if (IS_ERR(rt))
b23dd4fe DM	301	return rt;
b23dd4fe	302	ip_rt_put(rt);
e6b45241	303	flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
1da177e4	304	}
2d7192d6 DM	305	security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
2d7192d6 DM	306	return ip_route_output_flow(net, fl4, sk);
1da177e4 LT	307	}
1da177e4 LT	308
2d7192d6 DM	309	static inline struct rtable ip_route_newports(struct flowi4 fl4, struct rtable *rt,
	310	__be16 orig_sport, __be16 orig_dport,
	311	__be16 sport, __be16 dport,
	312	struct sock *sk)
1da177e4	313	{
dca8b089	314	if (sport != orig_sport \|\| dport != orig_dport) {
2d7192d6 DM	315	fl4->fl4_dport = dport;
2d7192d6 DM	316	fl4->fl4_sport = sport;
b23dd4fe	317	ip_rt_put(rt);
e6b45241 JA	318	flowi4_update_output(fl4, sk->sk_bound_dev_if,
	319	RT_CONN_FLAGS(sk), fl4->daddr,
	320	fl4->saddr);
2d7192d6 DM	321	security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
2d7192d6 DM	322	return ip_route_output_flow(sock_net(sk), fl4, sk);
1da177e4	323	}
b23dd4fe	324	return rt;
1da177e4 LT	325	}
1da177e4 LT	326
1668e010 KK	327	static inline int inet_iif(const struct sk_buff *skb)
1668e010 KK	328	{
0340d0b9 TH	329	struct rtable *rt = skb_rtable(skb);
	330
	331	if (rt && rt->rt_iif)
	332	return rt->rt_iif;
13378cad	333
13378cad	334	return skb->skb_iif;
1668e010 KK	335	}
1668e010 KK	336
323e126f DM	337	static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
	338	{
	339	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
fa50d974	340	struct net *net = dev_net(dst->dev);
323e126f DM	341
323e126f DM	342	if (hoplimit == 0)
fa50d974	343	hoplimit = net->ipv4.sysctl_ip_default_ttl;
323e126f DM	344	return hoplimit;
	345	}
	346
1da177e4	347	#endif /* _ROUTE_H */