[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;
	};
};

#ifdef __KERNEL__

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 = 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, int initial_ref);
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 int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
			      const struct flowi *fl, struct sock *sk,
			      int flags)
{
	return 0;
} 
#else
extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
		       const struct flowi *fl, struct sock *sk, int flags);
#endif
#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
1da177e4 LT	95	#ifdef __KERNEL__
1da177e4 LT	96
62fa8a84	97	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	98	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	99
	100	#define DST_METRICS_READ_ONLY 0x1UL
	101	#define __DST_METRICS_PTR(Y) \
	102	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	103	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	104
	105	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	106	{
	107	return dst->_metrics & DST_METRICS_READ_ONLY;
	108	}
	109
	110	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	111
	112	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	113	{
	114	unsigned long val = dst->_metrics;
	115	if (!(val & DST_METRICS_READ_ONLY))
	116	__dst_destroy_metrics_generic(dst, val);
	117	}
	118
	119	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	120	{
	121	unsigned long p = dst->_metrics;
	122
	123	if (p & DST_METRICS_READ_ONLY)
	124	return dst->ops->cow_metrics(dst, p);
	125	return __DST_METRICS_PTR(p);
	126	}
	127
	128	/* This may only be invoked before the entry has reached global
	129	* visibility.
	130	*/
	131	static inline void dst_init_metrics(struct dst_entry *dst,
	132	const u32 *src_metrics,
	133	bool read_only)
	134	{
	135	dst->_metrics = ((unsigned long) src_metrics) \|
	136	(read_only ? DST_METRICS_READ_ONLY : 0);
	137	}
	138
	139	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	140	{
	141	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	142
	143	if (dst_metrics) {
	144	u32 *src_metrics = DST_METRICS_PTR(src);
	145
	146	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	147	}
	148	}
	149
	150	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	151	{
	152	return DST_METRICS_PTR(dst);
	153	}
	154
1da177e4	155	static inline u32
5170ae82	156	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	157	{
62fa8a84 DM	158	u32 *p = DST_METRICS_PTR(dst);
	159
	160	return p[metric-1];
defb3519 DM	161	}
defb3519 DM	162
5170ae82 DM	163	static inline u32
	164	dst_metric(const struct dst_entry *dst, const int metric)
	165	{
0dbaee3b	166	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	167	metric == RTAX_ADVMSS \|\|
d33e4553 DM	168	metric == RTAX_MTU);
5170ae82 DM	169	return dst_metric_raw(dst, metric);
	170	}
	171
0dbaee3b DM	172	static inline u32
	173	dst_metric_advmss(const struct dst_entry *dst)
	174	{
	175	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	176
	177	if (!advmss)
	178	advmss = dst->ops->default_advmss(dst);
	179
	180	return advmss;
	181	}
	182
defb3519 DM	183	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	184	{
62fa8a84	185	u32 *p = dst_metrics_write_ptr(dst);
defb3519	186
62fa8a84 DM	187	if (p)
62fa8a84 DM	188	p[metric-1] = val;
1da177e4 LT	189	}
1da177e4 LT	190
0c3adfb8 GBY	191	static inline u32
	192	dst_feature(const struct dst_entry *dst, u32 feature)
	193	{
bb5b7c11	194	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	195	}
0c3adfb8 GBY	196
1da177e4 LT	197	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	198	{
d33e4553 DM	199	u32 mtu = dst_metric_raw(dst, RTAX_MTU);
	200
	201	if (!mtu)
	202	mtu = dst->ops->default_mtu(dst);
	203
1da177e4 LT	204	return mtu;
	205	}
	206
c1e20f7c SH	207	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	208	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	209	{
	210	return msecs_to_jiffies(dst_metric(dst, metric));
	211	}
	212
	213	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	214	unsigned long rtt)
	215	{
defb3519	216	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	217	}
c1e20f7c SH	218
1da177e4 LT	219	static inline u32
	220	dst_allfrag(const struct dst_entry *dst)
	221	{
0c3adfb8	222	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	223	return ret;
	224	}
	225
	226	static inline int
d33e4553	227	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	228	{
	229	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	230	}
	231
	232	static inline void dst_hold(struct dst_entry * dst)
	233	{
5635c10d ED	234	/*
	235	* If your kernel compilation stops here, please check
	236	* __pad_to_align_refcnt declaration in struct dst_entry
	237	*/
	238	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	239	atomic_inc(&dst->__refcnt);
	240	}
	241
03f49f34 PE	242	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	243	{
	244	dst_hold(dst);
	245	dst->__use++;
	246	dst->lastuse = time;
	247	}
	248
7fee226a ED	249	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	250	{
	251	dst->__use++;
	252	dst->lastuse = time;
	253	}
	254
1da177e4 LT	255	static inline
	256	struct dst_entry * dst_clone(struct dst_entry * dst)
	257	{
	258	if (dst)
	259	atomic_inc(&dst->__refcnt);
	260	return dst;
	261	}
	262
8d330868	263	extern void dst_release(struct dst_entry *dst);
7fee226a ED	264
	265	static inline void refdst_drop(unsigned long refdst)
	266	{
	267	if (!(refdst & SKB_DST_NOREF))
	268	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	269	}
	270
	271	/**
	272	* skb_dst_drop - drops skb dst
	273	* @skb: buffer
	274	*
	275	* Drops dst reference count if a reference was taken.
	276	*/
adf30907 ED	277	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	278	{
7fee226a ED	279	if (skb->_skb_refdst) {
	280	refdst_drop(skb->_skb_refdst);
	281	skb->_skb_refdst = 0UL;
	282	}
	283	}
	284
	285	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	286	{
	287	nskb->_skb_refdst = oskb->_skb_refdst;
	288	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	289	dst_clone(skb_dst(nskb));
	290	}
	291
	292	/**
	293	* skb_dst_force - makes sure skb dst is refcounted
	294	* @skb: buffer
	295	*
	296	* If dst is not yet refcounted, let's do it
	297	*/
	298	static inline void skb_dst_force(struct sk_buff *skb)
	299	{
	300	if (skb_dst_is_noref(skb)) {
	301	WARN_ON(!rcu_read_lock_held());
	302	skb->_skb_refdst &= ~SKB_DST_NOREF;
	303	dst_clone(skb_dst(skb));
	304	}
adf30907	305	}
1da177e4	306
d19d56dd	307
290b895e ED	308	/**
	309	* __skb_tunnel_rx - prepare skb for rx reinsert
	310	* @skb: buffer
	311	* @dev: tunnel device
	312	*
	313	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	314	* so make some cleanups. (no accounting done)
	315	*/
	316	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	317	{
	318	skb->dev = dev;
	319	skb->rxhash = 0;
	320	skb_set_queue_mapping(skb, 0);
	321	skb_dst_drop(skb);
	322	nf_reset(skb);
	323	}
	324
d19d56dd ED	325	/**
	326	* skb_tunnel_rx - prepare skb for rx reinsert
	327	* @skb: buffer
	328	* @dev: tunnel device
	329	*
	330	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	331	* so make some cleanups, and perform accounting.
290b895e	332	* Note: this accounting is not SMP safe.
d19d56dd ED	333	*/
	334	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	335	{
d19d56dd ED	336	/* TODO : stats should be SMP safe */
	337	dev->stats.rx_packets++;
	338	dev->stats.rx_bytes += skb->len;
290b895e	339	__skb_tunnel_rx(skb, dev);
d19d56dd ED	340	}
d19d56dd ED	341
1da177e4 LT	342	/* Children define the path of the packet through the
	343	* Linux networking. Thus, destinations are stackable.
	344	*/
	345
8764ab2c	346	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	347	{
8764ab2c	348	struct dst_entry *child = skb_dst(skb)->child;
1da177e4	349
8764ab2c	350	skb_dst_drop(skb);
1da177e4 LT	351	return child;
	352	}
	353
352e512c	354	extern int dst_discard(struct sk_buff *skb);
3c7bd1a1	355	extern void dst_alloc(struct dst_ops ops, int initial_ref);
1da177e4 LT	356	extern void __dst_free(struct dst_entry * dst);
	357	extern struct dst_entry dst_destroy(struct dst_entry dst);
	358
	359	static inline void dst_free(struct dst_entry * dst)
	360	{
	361	if (dst->obsolete > 1)
	362	return;
	363	if (!atomic_read(&dst->__refcnt)) {
	364	dst = dst_destroy(dst);
	365	if (!dst)
	366	return;
	367	}
	368	__dst_free(dst);
	369	}
	370
	371	static inline void dst_rcu_free(struct rcu_head *head)
	372	{
	373	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	374	dst_free(dst);
	375	}
	376
	377	static inline void dst_confirm(struct dst_entry *dst)
	378	{
	379	if (dst)
	380	neigh_confirm(dst->neighbour);
	381	}
	382
1da177e4 LT	383	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	384	{
adf30907	385	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	386	if (dst && dst->ops && dst->ops->link_failure)
	387	dst->ops->link_failure(skb);
	388	}
	389
	390	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	391	{
	392	unsigned long expires = jiffies + timeout;
	393
	394	if (expires == 0)
	395	expires = 1;
	396
	397	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	398	dst->expires = expires;
	399	}
	400
	401	/* Output packet to network from transport. */
	402	static inline int dst_output(struct sk_buff *skb)
	403	{
adf30907	404	return skb_dst(skb)->output(skb);
1da177e4 LT	405	}
	406
	407	/* Input packet from network to transport. */
	408	static inline int dst_input(struct sk_buff *skb)
	409	{
adf30907	410	return skb_dst(skb)->input(skb);
1da177e4 LT	411	}
	412
	413	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	414	{
	415	if (dst->obsolete)
	416	dst = dst->ops->check(dst, cookie);
	417	return dst;
	418	}
	419
	420	extern void dst_init(void);
	421
815f4e57 HX	422	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	423	enum {
80c0bc9e	424	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	425	};
815f4e57 HX	426
1da177e4 LT	427	struct flowi;
1da177e4 LT	428	#ifndef CONFIG_XFRM
52479b62	429	static inline int xfrm_lookup(struct net net, struct dst_entry *dst_p,
dee9f4bc DM	430	const struct flowi fl, struct sock sk,
dee9f4bc DM	431	int flags)
1da177e4 LT	432	{
	433	return 0;
	434	}
	435	#else
52479b62	436	extern int xfrm_lookup(struct net net, struct dst_entry *dst_p,
dee9f4bc	437	const struct flowi fl, struct sock sk, int flags);
1da177e4 LT	438	#endif
	439	#endif
	440
	441	#endif /* _NET_DST_H */