[deliverable/linux.git] / include / net / dst.h

/*
 * net/dst.h	Protocol independent destination cache definitions.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 */

#ifndef _NET_DST_H
#define _NET_DST_H

#include <net/dst_ops.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/rcupdate.h>
#include <linux/jiffies.h>
#include <net/neighbour.h>
#include <asm/processor.h>

#define DST_GC_MIN	(HZ/10)
#define DST_GC_INC	(HZ/2)
#define DST_GC_MAX	(120*HZ)

/* Each dst_entry has reference count and sits in some parent list(s).
 * When it is removed from parent list, it is "freed" (dst_free).
 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
 * is zero, it can be destroyed immediately, otherwise it is added
 * to gc list and garbage collector periodically checks the refcnt.
 */

struct sk_buff;

struct dst_entry {
	struct rcu_head		rcu_head;
	struct dst_entry	*child;
	struct net_device       *dev;
	struct  dst_ops	        *ops;
	unsigned long		_metrics;
	unsigned long		expires;
	struct dst_entry	*path;
	struct neighbour	*neighbour;
#ifdef CONFIG_XFRM
	struct xfrm_state	*xfrm;
#else
	void			*__pad1;
#endif
	int			(*input)(struct sk_buff*);
	int			(*output)(struct sk_buff*);

	int			flags;
#define DST_HOST		0x0001
#define DST_NOXFRM		0x0002
#define DST_NOPOLICY		0x0004
#define DST_NOHASH		0x0008
#define DST_NOCACHE		0x0010
#define DST_NOCOUNT		0x0020

	short			error;
	short			obsolete;
	unsigned short		header_len;	/* more space at head required */
	unsigned short		trailer_len;	/* space to reserve at tail */
#ifdef CONFIG_IP_ROUTE_CLASSID
	__u32			tclassid;
#else
	__u32			__pad2;
#endif

	/*
	 * Align __refcnt to a 64 bytes alignment
	 * (L1_CACHE_SIZE would be too much)
	 */
#ifdef CONFIG_64BIT
	long			__pad_to_align_refcnt[2];
#endif
	/*
	 * __refcnt wants to be on a different cache line from
	 * input/output/ops or performance tanks badly
	 */
	atomic_t		__refcnt;	/* client references	*/
	int			__use;
	unsigned long		lastuse;
	union {
		struct dst_entry	*next;
		struct rtable __rcu	*rt_next;
		struct rt6_info		*rt6_next;
		struct dn_route __rcu	*dn_next;
	};
};

extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
extern const u32 dst_default_metrics[RTAX_MAX];

#define DST_METRICS_READ_ONLY	0x1UL
#define __DST_METRICS_PTR(Y)	\
	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
#define DST_METRICS_PTR(X)	__DST_METRICS_PTR((X)->_metrics)

static inline bool dst_metrics_read_only(const struct dst_entry *dst)
{
	return dst->_metrics & DST_METRICS_READ_ONLY;
}

extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);

static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
{
	unsigned long val = dst->_metrics;
	if (!(val & DST_METRICS_READ_ONLY))
		__dst_destroy_metrics_generic(dst, val);
}

static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
{
	unsigned long p = dst->_metrics;

	BUG_ON(!p);

	if (p & DST_METRICS_READ_ONLY)
		return dst->ops->cow_metrics(dst, p);
	return __DST_METRICS_PTR(p);
}

/* This may only be invoked before the entry has reached global
 * visibility.
 */
static inline void dst_init_metrics(struct dst_entry *dst,
				    const u32 *src_metrics,
				    bool read_only)
{
	dst->_metrics = ((unsigned long) src_metrics) |
		(read_only ? DST_METRICS_READ_ONLY : 0);
}

static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
{
	u32 *dst_metrics = dst_metrics_write_ptr(dest);

	if (dst_metrics) {
		u32 *src_metrics = DST_METRICS_PTR(src);

		memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	}
}

static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
{
	return DST_METRICS_PTR(dst);
}

static inline u32
dst_metric_raw(const struct dst_entry *dst, const int metric)
{
	u32 *p = DST_METRICS_PTR(dst);

	return p[metric-1];
}

static inline u32
dst_metric(const struct dst_entry *dst, const int metric)
{
	WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
		     metric == RTAX_ADVMSS ||
		     metric == RTAX_MTU);
	return dst_metric_raw(dst, metric);
}

static inline u32
dst_metric_advmss(const struct dst_entry *dst)
{
	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);

	if (!advmss)
		advmss = dst->ops->default_advmss(dst);

	return advmss;
}

static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
{
	u32 *p = dst_metrics_write_ptr(dst);

	if (p)
		p[metric-1] = val;
}

static inline u32
dst_feature(const struct dst_entry *dst, u32 feature)
{
	return dst_metric(dst, RTAX_FEATURES) & feature;
}

static inline u32 dst_mtu(const struct dst_entry *dst)
{
	u32 mtu = dst_metric_raw(dst, RTAX_MTU);

	if (!mtu)
		mtu = dst->ops->default_mtu(dst);

	return mtu;
}

/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
{
	return msecs_to_jiffies(dst_metric(dst, metric));
}

static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
				      unsigned long rtt)
{
	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
}

static inline u32
dst_allfrag(const struct dst_entry *dst)
{
	int ret = dst_feature(dst,  RTAX_FEATURE_ALLFRAG);
	return ret;
}

static inline int
dst_metric_locked(const struct dst_entry *dst, int metric)
{
	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
}

static inline void dst_hold(struct dst_entry * dst)
{
	/*
	 * If your kernel compilation stops here, please check
	 * __pad_to_align_refcnt declaration in struct dst_entry
	 */
	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
	atomic_inc(&dst->__refcnt);
}

static inline void dst_use(struct dst_entry *dst, unsigned long time)
{
	dst_hold(dst);
	dst->__use++;
	dst->lastuse = time;
}

static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
{
	dst->__use++;
	dst->lastuse = time;
}

static inline
struct dst_entry * dst_clone(struct dst_entry * dst)
{
	if (dst)
		atomic_inc(&dst->__refcnt);
	return dst;
}

extern void dst_release(struct dst_entry *dst);

static inline void refdst_drop(unsigned long refdst)
{
	if (!(refdst & SKB_DST_NOREF))
		dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
}

/**
 * skb_dst_drop - drops skb dst
 * @skb: buffer
 *
 * Drops dst reference count if a reference was taken.
 */
static inline void skb_dst_drop(struct sk_buff *skb)
{
	if (skb->_skb_refdst) {
		refdst_drop(skb->_skb_refdst);
		skb->_skb_refdst = 0UL;
	}
}

static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
{
	nskb->_skb_refdst = oskb->_skb_refdst;
	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
		dst_clone(skb_dst(nskb));
}

/**
 * skb_dst_force - makes sure skb dst is refcounted
 * @skb: buffer
 *
 * If dst is not yet refcounted, let's do it
 */
static inline void skb_dst_force(struct sk_buff *skb)
{
	if (skb_dst_is_noref(skb)) {
		WARN_ON(!rcu_read_lock_held());
		skb->_skb_refdst &= ~SKB_DST_NOREF;
		dst_clone(skb_dst(skb));
	}
}


/**
 *	__skb_tunnel_rx - prepare skb for rx reinsert
 *	@skb: buffer
 *	@dev: tunnel device
 *
 *	After decapsulation, packet is going to re-enter (netif_rx()) our stack,
 *	so make some cleanups. (no accounting done)
 */
static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
{
	skb->dev = dev;
	skb->rxhash = 0;
	skb_set_queue_mapping(skb, 0);
	skb_dst_drop(skb);
	nf_reset(skb);
}

/**
 *	skb_tunnel_rx - prepare skb for rx reinsert
 *	@skb: buffer
 *	@dev: tunnel device
 *
 *	After decapsulation, packet is going to re-enter (netif_rx()) our stack,
 *	so make some cleanups, and perform accounting.
 *	Note: this accounting is not SMP safe.
 */
static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
{
	/* TODO : stats should be SMP safe */
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += skb->len;
	__skb_tunnel_rx(skb, dev);
}

/* Children define the path of the packet through the
 * Linux networking.  Thus, destinations are stackable.
 */

static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
{
	struct dst_entry *child = dst_clone(skb_dst(skb)->child);

	skb_dst_drop(skb);
	return child;
}

extern int dst_discard(struct sk_buff *skb);
extern void *dst_alloc(struct dst_ops * ops, struct net_device *dev,
		       int initial_ref, int initial_obsolete, int flags);
extern void __dst_free(struct dst_entry * dst);
extern struct dst_entry *dst_destroy(struct dst_entry * dst);

static inline void dst_free(struct dst_entry * dst)
{
	if (dst->obsolete > 1)
		return;
	if (!atomic_read(&dst->__refcnt)) {
		dst = dst_destroy(dst);
		if (!dst)
			return;
	}
	__dst_free(dst);
}

static inline void dst_rcu_free(struct rcu_head *head)
{
	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	dst_free(dst);
}

static inline void dst_confirm(struct dst_entry *dst)
{
	if (dst)
		neigh_confirm(dst->neighbour);
}

static inline void dst_link_failure(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	if (dst && dst->ops && dst->ops->link_failure)
		dst->ops->link_failure(skb);
}

static inline void dst_set_expires(struct dst_entry *dst, int timeout)
{
	unsigned long expires = jiffies + timeout;

	if (expires == 0)
		expires = 1;

	if (dst->expires == 0 || time_before(expires, dst->expires))
		dst->expires = expires;
}

/* Output packet to network from transport.  */
static inline int dst_output(struct sk_buff *skb)
{
	return skb_dst(skb)->output(skb);
}

/* Input packet from network to transport.  */
static inline int dst_input(struct sk_buff *skb)
{
	return skb_dst(skb)->input(skb);
}

static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
{
	if (dst->obsolete)
		dst = dst->ops->check(dst, cookie);
	return dst;
}

extern void		dst_init(void);

/* Flags for xfrm_lookup flags argument. */
enum {
	XFRM_LOOKUP_ICMP = 1 << 0,
};

struct flowi;
#ifndef CONFIG_XFRM
static inline struct dst_entry *xfrm_lookup(struct net *net,
					    struct dst_entry *dst_orig,
					    const struct flowi *fl, struct sock *sk,
					    int flags)
{
	return dst_orig;
} 
#else
extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
				     const struct flowi *fl, struct sock *sk,
				     int flags);
#endif

#endif /* _NET_DST_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/dst.h Protocol independent destination cache definitions.
	3	*
	4	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	5	*
	6	*/
	7
	8	#ifndef _NET_DST_H
	9	#define _NET_DST_H
	10
86393e52	11	#include <net/dst_ops.h>
14c85021	12	#include <linux/netdevice.h>
1da177e4 LT	13	#include <linux/rtnetlink.h>
	14	#include <linux/rcupdate.h>
	15	#include <linux/jiffies.h>
	16	#include <net/neighbour.h>
	17	#include <asm/processor.h>
	18
1da177e4 LT	19	#define DST_GC_MIN (HZ/10)
	20	#define DST_GC_INC (HZ/2)
	21	#define DST_GC_MAX (120*HZ)
	22
	23	/* Each dst_entry has reference count and sits in some parent list(s).
	24	* When it is removed from parent list, it is "freed" (dst_free).
	25	* After this it enters dead state (dst->obsolete > 0) and if its refcnt
	26	* is zero, it can be destroyed immediately, otherwise it is added
	27	* to gc list and garbage collector periodically checks the refcnt.
	28	*/
	29
	30	struct sk_buff;
	31
fd2c3ef7	32	struct dst_entry {
1e19e02c	33	struct rcu_head rcu_head;
1da177e4 LT	34	struct dst_entry *child;
1da177e4 LT	35	struct net_device *dev;
62fa8a84 DM	36	struct dst_ops *ops;
62fa8a84 DM	37	unsigned long _metrics;
1da177e4	38	unsigned long expires;
f1dd9c37	39	struct dst_entry *path;
1da177e4	40	struct neighbour *neighbour;
def8b4fa	41	#ifdef CONFIG_XFRM
1da177e4	42	struct xfrm_state *xfrm;
5635c10d ED	43	#else
5635c10d ED	44	void *__pad1;
def8b4fa	45	#endif
1da177e4 LT	46	int (input)(struct sk_buff);
	47	int (output)(struct sk_buff);
	48
f6b72b62 DM	49	int flags;
	50	#define DST_HOST 0x0001
	51	#define DST_NOXFRM 0x0002
	52	#define DST_NOPOLICY 0x0004
	53	#define DST_NOHASH 0x0008
	54	#define DST_NOCACHE 0x0010
	55	#define DST_NOCOUNT 0x0020
	56
62fa8a84 DM	57	short error;
	58	short obsolete;
	59	unsigned short header_len; /* more space at head required */
	60	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	61	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	62	__u32 tclassid;
5635c10d ED	63	#else
5635c10d ED	64	__u32 __pad2;
f1dd9c37 ZY	65	#endif
f1dd9c37 ZY	66
5635c10d ED	67	/*
	68	* Align __refcnt to a 64 bytes alignment
	69	* (L1_CACHE_SIZE would be too much)
	70	*/
	71	#ifdef CONFIG_64BIT
f6b72b62	72	long __pad_to_align_refcnt[2];
5635c10d	73	#endif
f1dd9c37 ZY	74	/*
	75	* __refcnt wants to be on a different cache line from
	76	* input/output/ops or performance tanks badly
	77	*/
1e19e02c ED	78	atomic_t __refcnt; /* client references */
1e19e02c ED	79	int __use;
f1dd9c37	80	unsigned long lastuse;
1e19e02c	81	union {
fc766e4c ED	82	struct dst_entry *next;
	83	struct rtable __rcu *rt_next;
	84	struct rt6_info *rt6_next;
	85	struct dn_route __rcu *dn_next;
1e19e02c	86	};
1da177e4 LT	87	};
1da177e4 LT	88
62fa8a84	89	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	90	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	91
	92	#define DST_METRICS_READ_ONLY 0x1UL
	93	#define __DST_METRICS_PTR(Y) \
	94	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	95	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	96
	97	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	98	{
	99	return dst->_metrics & DST_METRICS_READ_ONLY;
	100	}
	101
	102	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	103
	104	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	105	{
	106	unsigned long val = dst->_metrics;
	107	if (!(val & DST_METRICS_READ_ONLY))
	108	__dst_destroy_metrics_generic(dst, val);
	109	}
	110
	111	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	112	{
	113	unsigned long p = dst->_metrics;
	114
1f37070d SH	115	BUG_ON(!p);
1f37070d SH	116
62fa8a84 DM	117	if (p & DST_METRICS_READ_ONLY)
	118	return dst->ops->cow_metrics(dst, p);
	119	return __DST_METRICS_PTR(p);
	120	}
	121
	122	/* This may only be invoked before the entry has reached global
	123	* visibility.
	124	*/
	125	static inline void dst_init_metrics(struct dst_entry *dst,
	126	const u32 *src_metrics,
	127	bool read_only)
	128	{
	129	dst->_metrics = ((unsigned long) src_metrics) \|
	130	(read_only ? DST_METRICS_READ_ONLY : 0);
	131	}
	132
	133	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	134	{
	135	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	136
	137	if (dst_metrics) {
	138	u32 *src_metrics = DST_METRICS_PTR(src);
	139
	140	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	141	}
	142	}
	143
	144	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	145	{
	146	return DST_METRICS_PTR(dst);
	147	}
	148
1da177e4	149	static inline u32
5170ae82	150	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	151	{
62fa8a84 DM	152	u32 *p = DST_METRICS_PTR(dst);
	153
	154	return p[metric-1];
defb3519 DM	155	}
defb3519 DM	156
5170ae82 DM	157	static inline u32
	158	dst_metric(const struct dst_entry *dst, const int metric)
	159	{
0dbaee3b	160	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	161	metric == RTAX_ADVMSS \|\|
d33e4553 DM	162	metric == RTAX_MTU);
5170ae82 DM	163	return dst_metric_raw(dst, metric);
	164	}
	165
0dbaee3b DM	166	static inline u32
	167	dst_metric_advmss(const struct dst_entry *dst)
	168	{
	169	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	170
	171	if (!advmss)
	172	advmss = dst->ops->default_advmss(dst);
	173
	174	return advmss;
	175	}
	176
defb3519 DM	177	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	178	{
62fa8a84	179	u32 *p = dst_metrics_write_ptr(dst);
defb3519	180
62fa8a84 DM	181	if (p)
62fa8a84 DM	182	p[metric-1] = val;
1da177e4 LT	183	}
1da177e4 LT	184
0c3adfb8 GBY	185	static inline u32
	186	dst_feature(const struct dst_entry *dst, u32 feature)
	187	{
bb5b7c11	188	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	189	}
0c3adfb8 GBY	190
1da177e4 LT	191	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	192	{
d33e4553 DM	193	u32 mtu = dst_metric_raw(dst, RTAX_MTU);
	194
	195	if (!mtu)
	196	mtu = dst->ops->default_mtu(dst);
	197
1da177e4 LT	198	return mtu;
	199	}
	200
c1e20f7c SH	201	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	202	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	203	{
	204	return msecs_to_jiffies(dst_metric(dst, metric));
	205	}
	206
	207	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	208	unsigned long rtt)
	209	{
defb3519	210	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	211	}
c1e20f7c SH	212
1da177e4 LT	213	static inline u32
	214	dst_allfrag(const struct dst_entry *dst)
	215	{
0c3adfb8	216	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	217	return ret;
	218	}
	219
	220	static inline int
d33e4553	221	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	222	{
	223	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	224	}
	225
	226	static inline void dst_hold(struct dst_entry * dst)
	227	{
5635c10d ED	228	/*
	229	* If your kernel compilation stops here, please check
	230	* __pad_to_align_refcnt declaration in struct dst_entry
	231	*/
	232	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	233	atomic_inc(&dst->__refcnt);
	234	}
	235
03f49f34 PE	236	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	237	{
	238	dst_hold(dst);
	239	dst->__use++;
	240	dst->lastuse = time;
	241	}
	242
7fee226a ED	243	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	244	{
	245	dst->__use++;
	246	dst->lastuse = time;
	247	}
	248
1da177e4 LT	249	static inline
	250	struct dst_entry * dst_clone(struct dst_entry * dst)
	251	{
	252	if (dst)
	253	atomic_inc(&dst->__refcnt);
	254	return dst;
	255	}
	256
8d330868	257	extern void dst_release(struct dst_entry *dst);
7fee226a ED	258
	259	static inline void refdst_drop(unsigned long refdst)
	260	{
	261	if (!(refdst & SKB_DST_NOREF))
	262	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	263	}
	264
	265	/**
	266	* skb_dst_drop - drops skb dst
	267	* @skb: buffer
	268	*
	269	* Drops dst reference count if a reference was taken.
	270	*/
adf30907 ED	271	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	272	{
7fee226a ED	273	if (skb->_skb_refdst) {
	274	refdst_drop(skb->_skb_refdst);
	275	skb->_skb_refdst = 0UL;
	276	}
	277	}
	278
	279	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	280	{
	281	nskb->_skb_refdst = oskb->_skb_refdst;
	282	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	283	dst_clone(skb_dst(nskb));
	284	}
	285
	286	/**
	287	* skb_dst_force - makes sure skb dst is refcounted
	288	* @skb: buffer
	289	*
	290	* If dst is not yet refcounted, let's do it
	291	*/
	292	static inline void skb_dst_force(struct sk_buff *skb)
	293	{
	294	if (skb_dst_is_noref(skb)) {
	295	WARN_ON(!rcu_read_lock_held());
	296	skb->_skb_refdst &= ~SKB_DST_NOREF;
	297	dst_clone(skb_dst(skb));
	298	}
adf30907	299	}
1da177e4	300
d19d56dd	301
290b895e ED	302	/**
	303	* __skb_tunnel_rx - prepare skb for rx reinsert
	304	* @skb: buffer
	305	* @dev: tunnel device
	306	*
	307	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	308	* so make some cleanups. (no accounting done)
	309	*/
	310	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	311	{
	312	skb->dev = dev;
	313	skb->rxhash = 0;
	314	skb_set_queue_mapping(skb, 0);
	315	skb_dst_drop(skb);
	316	nf_reset(skb);
	317	}
	318
d19d56dd ED	319	/**
	320	* skb_tunnel_rx - prepare skb for rx reinsert
	321	* @skb: buffer
	322	* @dev: tunnel device
	323	*
	324	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	325	* so make some cleanups, and perform accounting.
290b895e	326	* Note: this accounting is not SMP safe.
d19d56dd ED	327	*/
	328	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	329	{
d19d56dd ED	330	/* TODO : stats should be SMP safe */
	331	dev->stats.rx_packets++;
	332	dev->stats.rx_bytes += skb->len;
290b895e	333	__skb_tunnel_rx(skb, dev);
d19d56dd ED	334	}
d19d56dd ED	335
1da177e4 LT	336	/* Children define the path of the packet through the
	337	* Linux networking. Thus, destinations are stackable.
	338	*/
	339
8764ab2c	340	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	341	{
e433430a	342	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	343
8764ab2c	344	skb_dst_drop(skb);
1da177e4 LT	345	return child;
	346	}
	347
352e512c	348	extern int dst_discard(struct sk_buff *skb);
5c1e6aa3 DM	349	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5c1e6aa3 DM	350	int initial_ref, int initial_obsolete, int flags);
1da177e4 LT	351	extern void __dst_free(struct dst_entry * dst);
	352	extern struct dst_entry dst_destroy(struct dst_entry dst);
	353
	354	static inline void dst_free(struct dst_entry * dst)
	355	{
	356	if (dst->obsolete > 1)
	357	return;
	358	if (!atomic_read(&dst->__refcnt)) {
	359	dst = dst_destroy(dst);
	360	if (!dst)
	361	return;
	362	}
	363	__dst_free(dst);
	364	}
	365
	366	static inline void dst_rcu_free(struct rcu_head *head)
	367	{
	368	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	369	dst_free(dst);
	370	}
	371
	372	static inline void dst_confirm(struct dst_entry *dst)
	373	{
	374	if (dst)
	375	neigh_confirm(dst->neighbour);
	376	}
	377
1da177e4 LT	378	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	379	{
adf30907	380	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	381	if (dst && dst->ops && dst->ops->link_failure)
	382	dst->ops->link_failure(skb);
	383	}
	384
	385	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	386	{
	387	unsigned long expires = jiffies + timeout;
	388
	389	if (expires == 0)
	390	expires = 1;
	391
	392	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	393	dst->expires = expires;
	394	}
	395
	396	/* Output packet to network from transport. */
	397	static inline int dst_output(struct sk_buff *skb)
	398	{
adf30907	399	return skb_dst(skb)->output(skb);
1da177e4 LT	400	}
	401
	402	/* Input packet from network to transport. */
	403	static inline int dst_input(struct sk_buff *skb)
	404	{
adf30907	405	return skb_dst(skb)->input(skb);
1da177e4 LT	406	}
	407
	408	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	409	{
	410	if (dst->obsolete)
	411	dst = dst->ops->check(dst, cookie);
	412	return dst;
	413	}
	414
	415	extern void dst_init(void);
	416
815f4e57 HX	417	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	418	enum {
80c0bc9e	419	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	420	};
815f4e57 HX	421
1da177e4 LT	422	struct flowi;
1da177e4 LT	423	#ifndef CONFIG_XFRM
452edd59 DM	424	static inline struct dst_entry xfrm_lookup(struct net net,
	425	struct dst_entry *dst_orig,
	426	const struct flowi fl, struct sock sk,
	427	int flags)
1da177e4	428	{
452edd59	429	return dst_orig;
1da177e4 LT	430	}
1da177e4 LT	431	#else
452edd59 DM	432	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	433	const struct flowi fl, struct sock sk,
	434	int flags);
1da177e4	435	#endif
1da177e4 LT	436
1da177e4 LT	437	#endif /* _NET_DST_H */