[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 __rcu	*_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
#define DST_NOPEER		0x0040

	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;
	};
};

static inline struct neighbour *dst_get_neighbour_noref(struct dst_entry *dst)
{
	return rcu_dereference(dst->_neighbour);
}

static inline struct neighbour *dst_get_neighbour_noref_raw(struct dst_entry *dst)
{
	return rcu_dereference_raw(dst->_neighbour);
}

static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh)
{
	rcu_assign_pointer(dst->_neighbour, neigh);
}

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)
{
	return dst->ops->mtu(dst);
}

/* 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;

	/*
	 * Clear rxhash so that we can recalulate the hash for the
	 * encapsulated packet, unless we have already determine the hash
	 * over the L4 4-tuple.
	 */
	if (!skb->l4_rxhash)
		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) {
		struct neighbour *n;

		rcu_read_lock();
		n = dst_get_neighbour_noref(dst);
		neigh_confirm(n);
		rcu_read_unlock();
	}
}

static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
{
	return dst->ops->neigh_lookup(dst, daddr);
}

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;
f2c31e32	40	struct neighbour __rcu *_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
e688a604	56	#define DST_NOPEER 0x0040
f6b72b62	57
62fa8a84 DM	58	short error;
	59	short obsolete;
	60	unsigned short header_len; /* more space at head required */
	61	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	62	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	63	__u32 tclassid;
5635c10d ED	64	#else
5635c10d ED	65	__u32 __pad2;
f1dd9c37 ZY	66	#endif
f1dd9c37 ZY	67
5635c10d ED	68	/*
	69	* Align __refcnt to a 64 bytes alignment
	70	* (L1_CACHE_SIZE would be too much)
	71	*/
	72	#ifdef CONFIG_64BIT
f6b72b62	73	long __pad_to_align_refcnt[2];
5635c10d	74	#endif
f1dd9c37 ZY	75	/*
	76	* __refcnt wants to be on a different cache line from
	77	* input/output/ops or performance tanks badly
	78	*/
1e19e02c ED	79	atomic_t __refcnt; /* client references */
1e19e02c ED	80	int __use;
f1dd9c37	81	unsigned long lastuse;
1e19e02c	82	union {
fc766e4c ED	83	struct dst_entry *next;
	84	struct rtable __rcu *rt_next;
	85	struct rt6_info *rt6_next;
	86	struct dn_route __rcu *dn_next;
1e19e02c	87	};
1da177e4 LT	88	};
1da177e4 LT	89
27217455	90	static inline struct neighbour dst_get_neighbour_noref(struct dst_entry dst)
69cce1d1	91	{
f2c31e32 ED	92	return rcu_dereference(dst->_neighbour);
	93	}
	94
27217455	95	static inline struct neighbour dst_get_neighbour_noref_raw(struct dst_entry dst)
f2c31e32 ED	96	{
f2c31e32 ED	97	return rcu_dereference_raw(dst->_neighbour);
69cce1d1 DM	98	}
	99
	100	static inline void dst_set_neighbour(struct dst_entry dst, struct neighbour neigh)
	101	{
f2c31e32	102	rcu_assign_pointer(dst->_neighbour, neigh);
69cce1d1 DM	103	}
69cce1d1 DM	104
62fa8a84	105	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	106	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	107
	108	#define DST_METRICS_READ_ONLY 0x1UL
	109	#define __DST_METRICS_PTR(Y) \
	110	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	111	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	112
	113	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	114	{
	115	return dst->_metrics & DST_METRICS_READ_ONLY;
	116	}
	117
	118	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	119
	120	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	121	{
	122	unsigned long val = dst->_metrics;
	123	if (!(val & DST_METRICS_READ_ONLY))
	124	__dst_destroy_metrics_generic(dst, val);
	125	}
	126
	127	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	128	{
	129	unsigned long p = dst->_metrics;
	130
1f37070d SH	131	BUG_ON(!p);
1f37070d SH	132
62fa8a84 DM	133	if (p & DST_METRICS_READ_ONLY)
	134	return dst->ops->cow_metrics(dst, p);
	135	return __DST_METRICS_PTR(p);
	136	}
	137
	138	/* This may only be invoked before the entry has reached global
	139	* visibility.
	140	*/
	141	static inline void dst_init_metrics(struct dst_entry *dst,
	142	const u32 *src_metrics,
	143	bool read_only)
	144	{
	145	dst->_metrics = ((unsigned long) src_metrics) \|
	146	(read_only ? DST_METRICS_READ_ONLY : 0);
	147	}
	148
	149	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	150	{
	151	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	152
	153	if (dst_metrics) {
	154	u32 *src_metrics = DST_METRICS_PTR(src);
	155
	156	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	157	}
	158	}
	159
	160	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	161	{
	162	return DST_METRICS_PTR(dst);
	163	}
	164
1da177e4	165	static inline u32
5170ae82	166	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	167	{
62fa8a84 DM	168	u32 *p = DST_METRICS_PTR(dst);
	169
	170	return p[metric-1];
defb3519 DM	171	}
defb3519 DM	172
5170ae82 DM	173	static inline u32
	174	dst_metric(const struct dst_entry *dst, const int metric)
	175	{
0dbaee3b	176	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	177	metric == RTAX_ADVMSS \|\|
d33e4553 DM	178	metric == RTAX_MTU);
5170ae82 DM	179	return dst_metric_raw(dst, metric);
	180	}
	181
0dbaee3b DM	182	static inline u32
	183	dst_metric_advmss(const struct dst_entry *dst)
	184	{
	185	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	186
	187	if (!advmss)
	188	advmss = dst->ops->default_advmss(dst);
	189
	190	return advmss;
	191	}
	192
defb3519 DM	193	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	194	{
62fa8a84	195	u32 *p = dst_metrics_write_ptr(dst);
defb3519	196
62fa8a84 DM	197	if (p)
62fa8a84 DM	198	p[metric-1] = val;
1da177e4 LT	199	}
1da177e4 LT	200
0c3adfb8 GBY	201	static inline u32
	202	dst_feature(const struct dst_entry *dst, u32 feature)
	203	{
bb5b7c11	204	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	205	}
0c3adfb8 GBY	206
1da177e4 LT	207	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	208	{
618f9bc7	209	return dst->ops->mtu(dst);
1da177e4 LT	210	}
1da177e4 LT	211
c1e20f7c SH	212	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	213	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	214	{
	215	return msecs_to_jiffies(dst_metric(dst, metric));
	216	}
	217
	218	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	219	unsigned long rtt)
	220	{
defb3519	221	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	222	}
c1e20f7c SH	223
1da177e4 LT	224	static inline u32
	225	dst_allfrag(const struct dst_entry *dst)
	226	{
0c3adfb8	227	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	228	return ret;
	229	}
	230
	231	static inline int
d33e4553	232	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	233	{
	234	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	235	}
	236
	237	static inline void dst_hold(struct dst_entry * dst)
	238	{
5635c10d ED	239	/*
	240	* If your kernel compilation stops here, please check
	241	* __pad_to_align_refcnt declaration in struct dst_entry
	242	*/
	243	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	244	atomic_inc(&dst->__refcnt);
	245	}
	246
03f49f34 PE	247	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	248	{
	249	dst_hold(dst);
	250	dst->__use++;
	251	dst->lastuse = time;
	252	}
	253
7fee226a ED	254	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	255	{
	256	dst->__use++;
	257	dst->lastuse = time;
	258	}
	259
1da177e4 LT	260	static inline
	261	struct dst_entry * dst_clone(struct dst_entry * dst)
	262	{
	263	if (dst)
	264	atomic_inc(&dst->__refcnt);
	265	return dst;
	266	}
	267
8d330868	268	extern void dst_release(struct dst_entry *dst);
7fee226a ED	269
	270	static inline void refdst_drop(unsigned long refdst)
	271	{
	272	if (!(refdst & SKB_DST_NOREF))
	273	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	274	}
	275
	276	/**
	277	* skb_dst_drop - drops skb dst
	278	* @skb: buffer
	279	*
	280	* Drops dst reference count if a reference was taken.
	281	*/
adf30907 ED	282	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	283	{
7fee226a ED	284	if (skb->_skb_refdst) {
	285	refdst_drop(skb->_skb_refdst);
	286	skb->_skb_refdst = 0UL;
	287	}
	288	}
	289
	290	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	291	{
	292	nskb->_skb_refdst = oskb->_skb_refdst;
	293	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	294	dst_clone(skb_dst(nskb));
	295	}
	296
	297	/**
	298	* skb_dst_force - makes sure skb dst is refcounted
	299	* @skb: buffer
	300	*
	301	* If dst is not yet refcounted, let's do it
	302	*/
	303	static inline void skb_dst_force(struct sk_buff *skb)
	304	{
	305	if (skb_dst_is_noref(skb)) {
	306	WARN_ON(!rcu_read_lock_held());
	307	skb->_skb_refdst &= ~SKB_DST_NOREF;
	308	dst_clone(skb_dst(skb));
	309	}
adf30907	310	}
1da177e4	311
d19d56dd	312
290b895e ED	313	/**
	314	* __skb_tunnel_rx - prepare skb for rx reinsert
	315	* @skb: buffer
	316	* @dev: tunnel device
	317	*
	318	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	319	* so make some cleanups. (no accounting done)
	320	*/
	321	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	322	{
	323	skb->dev = dev;
bdeab991 TH	324
	325	/*
	326	* Clear rxhash so that we can recalulate the hash for the
	327	* encapsulated packet, unless we have already determine the hash
	328	* over the L4 4-tuple.
	329	*/
	330	if (!skb->l4_rxhash)
	331	skb->rxhash = 0;
290b895e ED	332	skb_set_queue_mapping(skb, 0);
	333	skb_dst_drop(skb);
	334	nf_reset(skb);
	335	}
	336
d19d56dd ED	337	/**
	338	* skb_tunnel_rx - prepare skb for rx reinsert
	339	* @skb: buffer
	340	* @dev: tunnel device
	341	*
	342	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	343	* so make some cleanups, and perform accounting.
290b895e	344	* Note: this accounting is not SMP safe.
d19d56dd ED	345	*/
	346	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	347	{
d19d56dd ED	348	/* TODO : stats should be SMP safe */
	349	dev->stats.rx_packets++;
	350	dev->stats.rx_bytes += skb->len;
290b895e	351	__skb_tunnel_rx(skb, dev);
d19d56dd ED	352	}
d19d56dd ED	353
1da177e4 LT	354	/* Children define the path of the packet through the
	355	* Linux networking. Thus, destinations are stackable.
	356	*/
	357
8764ab2c	358	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	359	{
e433430a	360	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	361
8764ab2c	362	skb_dst_drop(skb);
1da177e4 LT	363	return child;
	364	}
	365
352e512c	366	extern int dst_discard(struct sk_buff *skb);
5c1e6aa3 DM	367	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5c1e6aa3 DM	368	int initial_ref, int initial_obsolete, int flags);
1da177e4 LT	369	extern void __dst_free(struct dst_entry * dst);
	370	extern struct dst_entry dst_destroy(struct dst_entry dst);
	371
	372	static inline void dst_free(struct dst_entry * dst)
	373	{
	374	if (dst->obsolete > 1)
	375	return;
	376	if (!atomic_read(&dst->__refcnt)) {
	377	dst = dst_destroy(dst);
	378	if (!dst)
	379	return;
	380	}
	381	__dst_free(dst);
	382	}
	383
	384	static inline void dst_rcu_free(struct rcu_head *head)
	385	{
	386	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	387	dst_free(dst);
	388	}
	389
	390	static inline void dst_confirm(struct dst_entry *dst)
	391	{
69cce1d1	392	if (dst) {
f2c31e32 ED	393	struct neighbour *n;
	394
	395	rcu_read_lock();
27217455	396	n = dst_get_neighbour_noref(dst);
69cce1d1	397	neigh_confirm(n);
f2c31e32	398	rcu_read_unlock();
69cce1d1	399	}
1da177e4 LT	400	}
1da177e4 LT	401
d3aaeb38 DM	402	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
	403	{
	404	return dst->ops->neigh_lookup(dst, daddr);
	405	}
	406
1da177e4 LT	407	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	408	{
adf30907	409	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	410	if (dst && dst->ops && dst->ops->link_failure)
	411	dst->ops->link_failure(skb);
	412	}
	413
	414	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	415	{
	416	unsigned long expires = jiffies + timeout;
	417
	418	if (expires == 0)
	419	expires = 1;
	420
	421	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	422	dst->expires = expires;
	423	}
	424
	425	/* Output packet to network from transport. */
	426	static inline int dst_output(struct sk_buff *skb)
	427	{
adf30907	428	return skb_dst(skb)->output(skb);
1da177e4 LT	429	}
	430
	431	/* Input packet from network to transport. */
	432	static inline int dst_input(struct sk_buff *skb)
	433	{
adf30907	434	return skb_dst(skb)->input(skb);
1da177e4 LT	435	}
	436
	437	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	438	{
	439	if (dst->obsolete)
	440	dst = dst->ops->check(dst, cookie);
	441	return dst;
	442	}
	443
	444	extern void dst_init(void);
	445
815f4e57 HX	446	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	447	enum {
80c0bc9e	448	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	449	};
815f4e57 HX	450
1da177e4 LT	451	struct flowi;
1da177e4 LT	452	#ifndef CONFIG_XFRM
452edd59 DM	453	static inline struct dst_entry xfrm_lookup(struct net net,
	454	struct dst_entry *dst_orig,
	455	const struct flowi fl, struct sock sk,
	456	int flags)
1da177e4	457	{
452edd59	458	return dst_orig;
1da177e4 LT	459	}
1da177e4 LT	460	#else
452edd59 DM	461	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	462	const struct flowi fl, struct sock sk,
	463	int flags);
1da177e4	464	#endif
1da177e4 LT	465
1da177e4 LT	466	#endif /* _NET_DST_H */