[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>

/*
 * 0 - no debugging messages
 * 1 - rare events and bugs (default)
 * 2 - trace mode.
 */
#define RT_CACHE_DEBUG		0

#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;
	struct hh_cache		*hh;
#ifdef CONFIG_XFRM
	struct xfrm_state	*xfrm;
#else
	void			*__pad1;
#endif
	int			(*input)(struct sk_buff*);
	int			(*output)(struct sk_buff*);

	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[1];
#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;
	int			flags;
#define DST_HOST		0x0001
#define DST_NOXFRM		0x0002
#define DST_NOPOLICY		0x0004
#define DST_NOHASH		0x0008
#define DST_NOCACHE		0x0010
	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;

	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
	19	/*
	20	* 0 - no debugging messages
	21	* 1 - rare events and bugs (default)
	22	* 2 - trace mode.
	23	*/
	24	#define RT_CACHE_DEBUG 0
	25
	26	#define DST_GC_MIN (HZ/10)
	27	#define DST_GC_INC (HZ/2)
	28	#define DST_GC_MAX (120*HZ)
	29
	30	/* Each dst_entry has reference count and sits in some parent list(s).
	31	* When it is removed from parent list, it is "freed" (dst_free).
	32	* After this it enters dead state (dst->obsolete > 0) and if its refcnt
	33	* is zero, it can be destroyed immediately, otherwise it is added
	34	* to gc list and garbage collector periodically checks the refcnt.
	35	*/
	36
	37	struct sk_buff;
	38
fd2c3ef7	39	struct dst_entry {
1e19e02c	40	struct rcu_head rcu_head;
1da177e4 LT	41	struct dst_entry *child;
1da177e4 LT	42	struct net_device *dev;
62fa8a84 DM	43	struct dst_ops *ops;
62fa8a84 DM	44	unsigned long _metrics;
1da177e4	45	unsigned long expires;
f1dd9c37	46	struct dst_entry *path;
1da177e4 LT	47	struct neighbour *neighbour;
1da177e4 LT	48	struct hh_cache *hh;
def8b4fa	49	#ifdef CONFIG_XFRM
1da177e4	50	struct xfrm_state *xfrm;
5635c10d ED	51	#else
5635c10d ED	52	void *__pad1;
def8b4fa	53	#endif
1da177e4 LT	54	int (input)(struct sk_buff);
	55	int (output)(struct sk_buff);
	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
5635c10d ED	72	long __pad_to_align_refcnt[1];
5635c10d ED	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;
62fa8a84 DM	81	int flags;
	82	#define DST_HOST 0x0001
	83	#define DST_NOXFRM 0x0002
	84	#define DST_NOPOLICY 0x0004
	85	#define DST_NOHASH 0x0008
	86	#define DST_NOCACHE 0x0010
1e19e02c	87	union {
fc766e4c ED	88	struct dst_entry *next;
	89	struct rtable __rcu *rt_next;
	90	struct rt6_info *rt6_next;
	91	struct dn_route __rcu *dn_next;
1e19e02c	92	};
1da177e4 LT	93	};
1da177e4 LT	94
62fa8a84	95	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	96	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	97
	98	#define DST_METRICS_READ_ONLY 0x1UL
	99	#define __DST_METRICS_PTR(Y) \
	100	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	101	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	102
	103	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	104	{
	105	return dst->_metrics & DST_METRICS_READ_ONLY;
	106	}
	107
	108	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	109
	110	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	111	{
	112	unsigned long val = dst->_metrics;
	113	if (!(val & DST_METRICS_READ_ONLY))
	114	__dst_destroy_metrics_generic(dst, val);
	115	}
	116
	117	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	118	{
	119	unsigned long p = dst->_metrics;
	120
	121	if (p & DST_METRICS_READ_ONLY)
	122	return dst->ops->cow_metrics(dst, p);
	123	return __DST_METRICS_PTR(p);
	124	}
	125
	126	/* This may only be invoked before the entry has reached global
	127	* visibility.
	128	*/
	129	static inline void dst_init_metrics(struct dst_entry *dst,
	130	const u32 *src_metrics,
	131	bool read_only)
	132	{
	133	dst->_metrics = ((unsigned long) src_metrics) \|
	134	(read_only ? DST_METRICS_READ_ONLY : 0);
	135	}
	136
	137	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	138	{
	139	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	140
	141	if (dst_metrics) {
	142	u32 *src_metrics = DST_METRICS_PTR(src);
	143
	144	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	145	}
	146	}
	147
	148	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	149	{
	150	return DST_METRICS_PTR(dst);
	151	}
	152
1da177e4	153	static inline u32
5170ae82	154	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	155	{
62fa8a84 DM	156	u32 *p = DST_METRICS_PTR(dst);
	157
	158	return p[metric-1];
defb3519 DM	159	}
defb3519 DM	160
5170ae82 DM	161	static inline u32
	162	dst_metric(const struct dst_entry *dst, const int metric)
	163	{
0dbaee3b	164	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	165	metric == RTAX_ADVMSS \|\|
d33e4553 DM	166	metric == RTAX_MTU);
5170ae82 DM	167	return dst_metric_raw(dst, metric);
	168	}
	169
0dbaee3b DM	170	static inline u32
	171	dst_metric_advmss(const struct dst_entry *dst)
	172	{
	173	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	174
	175	if (!advmss)
	176	advmss = dst->ops->default_advmss(dst);
	177
	178	return advmss;
	179	}
	180
defb3519 DM	181	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	182	{
62fa8a84	183	u32 *p = dst_metrics_write_ptr(dst);
defb3519	184
62fa8a84 DM	185	if (p)
62fa8a84 DM	186	p[metric-1] = val;
1da177e4 LT	187	}
1da177e4 LT	188
0c3adfb8 GBY	189	static inline u32
	190	dst_feature(const struct dst_entry *dst, u32 feature)
	191	{
bb5b7c11	192	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	193	}
0c3adfb8 GBY	194
1da177e4 LT	195	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	196	{
d33e4553 DM	197	u32 mtu = dst_metric_raw(dst, RTAX_MTU);
	198
	199	if (!mtu)
	200	mtu = dst->ops->default_mtu(dst);
	201
1da177e4 LT	202	return mtu;
	203	}
	204
c1e20f7c SH	205	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	206	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	207	{
	208	return msecs_to_jiffies(dst_metric(dst, metric));
	209	}
	210
	211	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	212	unsigned long rtt)
	213	{
defb3519	214	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	215	}
c1e20f7c SH	216
1da177e4 LT	217	static inline u32
	218	dst_allfrag(const struct dst_entry *dst)
	219	{
0c3adfb8	220	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	221	return ret;
	222	}
	223
	224	static inline int
d33e4553	225	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	226	{
	227	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	228	}
	229
	230	static inline void dst_hold(struct dst_entry * dst)
	231	{
5635c10d ED	232	/*
	233	* If your kernel compilation stops here, please check
	234	* __pad_to_align_refcnt declaration in struct dst_entry
	235	*/
	236	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	237	atomic_inc(&dst->__refcnt);
	238	}
	239
03f49f34 PE	240	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	241	{
	242	dst_hold(dst);
	243	dst->__use++;
	244	dst->lastuse = time;
	245	}
	246
7fee226a ED	247	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	248	{
	249	dst->__use++;
	250	dst->lastuse = time;
	251	}
	252
1da177e4 LT	253	static inline
	254	struct dst_entry * dst_clone(struct dst_entry * dst)
	255	{
	256	if (dst)
	257	atomic_inc(&dst->__refcnt);
	258	return dst;
	259	}
	260
8d330868	261	extern void dst_release(struct dst_entry *dst);
7fee226a ED	262
	263	static inline void refdst_drop(unsigned long refdst)
	264	{
	265	if (!(refdst & SKB_DST_NOREF))
	266	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	267	}
	268
	269	/**
	270	* skb_dst_drop - drops skb dst
	271	* @skb: buffer
	272	*
	273	* Drops dst reference count if a reference was taken.
	274	*/
adf30907 ED	275	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	276	{
7fee226a ED	277	if (skb->_skb_refdst) {
	278	refdst_drop(skb->_skb_refdst);
	279	skb->_skb_refdst = 0UL;
	280	}
	281	}
	282
	283	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	284	{
	285	nskb->_skb_refdst = oskb->_skb_refdst;
	286	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	287	dst_clone(skb_dst(nskb));
	288	}
	289
	290	/**
	291	* skb_dst_force - makes sure skb dst is refcounted
	292	* @skb: buffer
	293	*
	294	* If dst is not yet refcounted, let's do it
	295	*/
	296	static inline void skb_dst_force(struct sk_buff *skb)
	297	{
	298	if (skb_dst_is_noref(skb)) {
	299	WARN_ON(!rcu_read_lock_held());
	300	skb->_skb_refdst &= ~SKB_DST_NOREF;
	301	dst_clone(skb_dst(skb));
	302	}
adf30907	303	}
1da177e4	304
d19d56dd	305
290b895e ED	306	/**
	307	* __skb_tunnel_rx - prepare skb for rx reinsert
	308	* @skb: buffer
	309	* @dev: tunnel device
	310	*
	311	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	312	* so make some cleanups. (no accounting done)
	313	*/
	314	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	315	{
	316	skb->dev = dev;
	317	skb->rxhash = 0;
	318	skb_set_queue_mapping(skb, 0);
	319	skb_dst_drop(skb);
	320	nf_reset(skb);
	321	}
	322
d19d56dd ED	323	/**
	324	* skb_tunnel_rx - prepare skb for rx reinsert
	325	* @skb: buffer
	326	* @dev: tunnel device
	327	*
	328	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	329	* so make some cleanups, and perform accounting.
290b895e	330	* Note: this accounting is not SMP safe.
d19d56dd ED	331	*/
	332	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	333	{
d19d56dd ED	334	/* TODO : stats should be SMP safe */
	335	dev->stats.rx_packets++;
	336	dev->stats.rx_bytes += skb->len;
290b895e	337	__skb_tunnel_rx(skb, dev);
d19d56dd ED	338	}
d19d56dd ED	339
1da177e4 LT	340	/* Children define the path of the packet through the
	341	* Linux networking. Thus, destinations are stackable.
	342	*/
	343
8764ab2c	344	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	345	{
e433430a	346	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	347
8764ab2c	348	skb_dst_drop(skb);
1da177e4 LT	349	return child;
	350	}
	351
352e512c	352	extern int dst_discard(struct sk_buff *skb);
5c1e6aa3 DM	353	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5c1e6aa3 DM	354	int initial_ref, int initial_obsolete, int flags);
1da177e4 LT	355	extern void __dst_free(struct dst_entry * dst);
	356	extern struct dst_entry dst_destroy(struct dst_entry dst);
	357
	358	static inline void dst_free(struct dst_entry * dst)
	359	{
	360	if (dst->obsolete > 1)
	361	return;
	362	if (!atomic_read(&dst->__refcnt)) {
	363	dst = dst_destroy(dst);
	364	if (!dst)
	365	return;
	366	}
	367	__dst_free(dst);
	368	}
	369
	370	static inline void dst_rcu_free(struct rcu_head *head)
	371	{
	372	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	373	dst_free(dst);
	374	}
	375
	376	static inline void dst_confirm(struct dst_entry *dst)
	377	{
	378	if (dst)
	379	neigh_confirm(dst->neighbour);
	380	}
	381
1da177e4 LT	382	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	383	{
adf30907	384	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	385	if (dst && dst->ops && dst->ops->link_failure)
	386	dst->ops->link_failure(skb);
	387	}
	388
	389	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	390	{
	391	unsigned long expires = jiffies + timeout;
	392
	393	if (expires == 0)
	394	expires = 1;
	395
	396	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	397	dst->expires = expires;
	398	}
	399
	400	/* Output packet to network from transport. */
	401	static inline int dst_output(struct sk_buff *skb)
	402	{
adf30907	403	return skb_dst(skb)->output(skb);
1da177e4 LT	404	}
	405
	406	/* Input packet from network to transport. */
	407	static inline int dst_input(struct sk_buff *skb)
	408	{
adf30907	409	return skb_dst(skb)->input(skb);
1da177e4 LT	410	}
	411
	412	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	413	{
	414	if (dst->obsolete)
	415	dst = dst->ops->check(dst, cookie);
	416	return dst;
	417	}
	418
	419	extern void dst_init(void);
	420
815f4e57 HX	421	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	422	enum {
80c0bc9e	423	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	424	};
815f4e57 HX	425
1da177e4 LT	426	struct flowi;
1da177e4 LT	427	#ifndef CONFIG_XFRM
452edd59 DM	428	static inline struct dst_entry xfrm_lookup(struct net net,
	429	struct dst_entry *dst_orig,
	430	const struct flowi fl, struct sock sk,
	431	int flags)
1da177e4	432	{
452edd59	433	return dst_orig;
1da177e4 LT	434	}
1da177e4 LT	435	#else
452edd59 DM	436	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	437	const struct flowi fl, struct sock sk,
	438	int flags);
1da177e4	439	#endif
1da177e4 LT	440
1da177e4 LT	441	#endif /* _NET_DST_H */