[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/bug.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>
1da177e4 LT	14	#include <linux/rcupdate.h>
187f1882	15	#include <linux/bug.h>
1da177e4 LT	16	#include <linux/jiffies.h>
	17	#include <net/neighbour.h>
	18	#include <asm/processor.h>
	19
1da177e4 LT	20	#define DST_GC_MIN (HZ/10)
	21	#define DST_GC_INC (HZ/2)
	22	#define DST_GC_MAX (120*HZ)
	23
	24	/* Each dst_entry has reference count and sits in some parent list(s).
	25	* When it is removed from parent list, it is "freed" (dst_free).
	26	* After this it enters dead state (dst->obsolete > 0) and if its refcnt
	27	* is zero, it can be destroyed immediately, otherwise it is added
	28	* to gc list and garbage collector periodically checks the refcnt.
	29	*/
	30
	31	struct sk_buff;
	32
fd2c3ef7	33	struct dst_entry {
1e19e02c	34	struct rcu_head rcu_head;
1da177e4 LT	35	struct dst_entry *child;
1da177e4 LT	36	struct net_device *dev;
62fa8a84 DM	37	struct dst_ops *ops;
62fa8a84 DM	38	unsigned long _metrics;
1da177e4	39	unsigned long expires;
f1dd9c37	40	struct dst_entry *path;
f2c31e32	41	struct neighbour __rcu *_neighbour;
def8b4fa	42	#ifdef CONFIG_XFRM
1da177e4	43	struct xfrm_state *xfrm;
5635c10d ED	44	#else
5635c10d ED	45	void *__pad1;
def8b4fa	46	#endif
1da177e4 LT	47	int (input)(struct sk_buff);
	48	int (output)(struct sk_buff);
	49
f6b72b62 DM	50	int flags;
	51	#define DST_HOST 0x0001
	52	#define DST_NOXFRM 0x0002
	53	#define DST_NOPOLICY 0x0004
	54	#define DST_NOHASH 0x0008
	55	#define DST_NOCACHE 0x0010
	56	#define DST_NOCOUNT 0x0020
e688a604	57	#define DST_NOPEER 0x0040
f6b72b62	58
62fa8a84 DM	59	short error;
	60	short obsolete;
	61	unsigned short header_len; /* more space at head required */
	62	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	63	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	64	__u32 tclassid;
5635c10d ED	65	#else
5635c10d ED	66	__u32 __pad2;
f1dd9c37 ZY	67	#endif
f1dd9c37 ZY	68
5635c10d ED	69	/*
	70	* Align __refcnt to a 64 bytes alignment
	71	* (L1_CACHE_SIZE would be too much)
	72	*/
	73	#ifdef CONFIG_64BIT
f6b72b62	74	long __pad_to_align_refcnt[2];
5635c10d	75	#endif
f1dd9c37 ZY	76	/*
	77	* __refcnt wants to be on a different cache line from
	78	* input/output/ops or performance tanks badly
	79	*/
1e19e02c ED	80	atomic_t __refcnt; /* client references */
1e19e02c ED	81	int __use;
f1dd9c37	82	unsigned long lastuse;
1e19e02c	83	union {
fc766e4c ED	84	struct dst_entry *next;
	85	struct rtable __rcu *rt_next;
	86	struct rt6_info *rt6_next;
	87	struct dn_route __rcu *dn_next;
1e19e02c	88	};
1da177e4 LT	89	};
1da177e4 LT	90
27217455	91	static inline struct neighbour dst_get_neighbour_noref(struct dst_entry dst)
69cce1d1	92	{
f2c31e32 ED	93	return rcu_dereference(dst->_neighbour);
	94	}
	95
27217455	96	static inline struct neighbour dst_get_neighbour_noref_raw(struct dst_entry dst)
f2c31e32 ED	97	{
f2c31e32 ED	98	return rcu_dereference_raw(dst->_neighbour);
69cce1d1 DM	99	}
	100
	101	static inline void dst_set_neighbour(struct dst_entry dst, struct neighbour neigh)
	102	{
f2c31e32	103	rcu_assign_pointer(dst->_neighbour, neigh);
69cce1d1 DM	104	}
69cce1d1 DM	105
62fa8a84	106	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	107	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	108
	109	#define DST_METRICS_READ_ONLY 0x1UL
	110	#define __DST_METRICS_PTR(Y) \
	111	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	112	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	113
	114	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	115	{
	116	return dst->_metrics & DST_METRICS_READ_ONLY;
	117	}
	118
	119	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	120
	121	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	122	{
	123	unsigned long val = dst->_metrics;
	124	if (!(val & DST_METRICS_READ_ONLY))
	125	__dst_destroy_metrics_generic(dst, val);
	126	}
	127
	128	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	129	{
	130	unsigned long p = dst->_metrics;
	131
1f37070d SH	132	BUG_ON(!p);
1f37070d SH	133
62fa8a84 DM	134	if (p & DST_METRICS_READ_ONLY)
	135	return dst->ops->cow_metrics(dst, p);
	136	return __DST_METRICS_PTR(p);
	137	}
	138
	139	/* This may only be invoked before the entry has reached global
	140	* visibility.
	141	*/
	142	static inline void dst_init_metrics(struct dst_entry *dst,
	143	const u32 *src_metrics,
	144	bool read_only)
	145	{
	146	dst->_metrics = ((unsigned long) src_metrics) \|
	147	(read_only ? DST_METRICS_READ_ONLY : 0);
	148	}
	149
	150	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	151	{
	152	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	153
	154	if (dst_metrics) {
	155	u32 *src_metrics = DST_METRICS_PTR(src);
	156
	157	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	158	}
	159	}
	160
	161	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	162	{
	163	return DST_METRICS_PTR(dst);
	164	}
	165
1da177e4	166	static inline u32
5170ae82	167	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	168	{
62fa8a84 DM	169	u32 *p = DST_METRICS_PTR(dst);
	170
	171	return p[metric-1];
defb3519 DM	172	}
defb3519 DM	173
5170ae82 DM	174	static inline u32
	175	dst_metric(const struct dst_entry *dst, const int metric)
	176	{
0dbaee3b	177	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	178	metric == RTAX_ADVMSS \|\|
d33e4553 DM	179	metric == RTAX_MTU);
5170ae82 DM	180	return dst_metric_raw(dst, metric);
	181	}
	182
0dbaee3b DM	183	static inline u32
	184	dst_metric_advmss(const struct dst_entry *dst)
	185	{
	186	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	187
	188	if (!advmss)
	189	advmss = dst->ops->default_advmss(dst);
	190
	191	return advmss;
	192	}
	193
defb3519 DM	194	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	195	{
62fa8a84	196	u32 *p = dst_metrics_write_ptr(dst);
defb3519	197
62fa8a84 DM	198	if (p)
62fa8a84 DM	199	p[metric-1] = val;
1da177e4 LT	200	}
1da177e4 LT	201
0c3adfb8 GBY	202	static inline u32
	203	dst_feature(const struct dst_entry *dst, u32 feature)
	204	{
bb5b7c11	205	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	206	}
0c3adfb8 GBY	207
1da177e4 LT	208	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	209	{
618f9bc7	210	return dst->ops->mtu(dst);
1da177e4 LT	211	}
1da177e4 LT	212
c1e20f7c SH	213	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	214	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	215	{
	216	return msecs_to_jiffies(dst_metric(dst, metric));
	217	}
	218
	219	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	220	unsigned long rtt)
	221	{
defb3519	222	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	223	}
c1e20f7c SH	224
1da177e4 LT	225	static inline u32
	226	dst_allfrag(const struct dst_entry *dst)
	227	{
0c3adfb8	228	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	229	return ret;
	230	}
	231
	232	static inline int
d33e4553	233	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	234	{
	235	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	236	}
	237
	238	static inline void dst_hold(struct dst_entry * dst)
	239	{
5635c10d ED	240	/*
	241	* If your kernel compilation stops here, please check
	242	* __pad_to_align_refcnt declaration in struct dst_entry
	243	*/
	244	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	245	atomic_inc(&dst->__refcnt);
	246	}
	247
03f49f34 PE	248	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	249	{
	250	dst_hold(dst);
	251	dst->__use++;
	252	dst->lastuse = time;
	253	}
	254
7fee226a ED	255	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	256	{
	257	dst->__use++;
	258	dst->lastuse = time;
	259	}
	260
1da177e4 LT	261	static inline
	262	struct dst_entry * dst_clone(struct dst_entry * dst)
	263	{
	264	if (dst)
	265	atomic_inc(&dst->__refcnt);
	266	return dst;
	267	}
	268
8d330868	269	extern void dst_release(struct dst_entry *dst);
7fee226a ED	270
	271	static inline void refdst_drop(unsigned long refdst)
	272	{
	273	if (!(refdst & SKB_DST_NOREF))
	274	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	275	}
	276
	277	/**
	278	* skb_dst_drop - drops skb dst
	279	* @skb: buffer
	280	*
	281	* Drops dst reference count if a reference was taken.
	282	*/
adf30907 ED	283	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	284	{
7fee226a ED	285	if (skb->_skb_refdst) {
	286	refdst_drop(skb->_skb_refdst);
	287	skb->_skb_refdst = 0UL;
	288	}
	289	}
	290
	291	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	292	{
	293	nskb->_skb_refdst = oskb->_skb_refdst;
	294	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	295	dst_clone(skb_dst(nskb));
	296	}
	297
	298	/**
	299	* skb_dst_force - makes sure skb dst is refcounted
	300	* @skb: buffer
	301	*
	302	* If dst is not yet refcounted, let's do it
	303	*/
	304	static inline void skb_dst_force(struct sk_buff *skb)
	305	{
	306	if (skb_dst_is_noref(skb)) {
	307	WARN_ON(!rcu_read_lock_held());
	308	skb->_skb_refdst &= ~SKB_DST_NOREF;
	309	dst_clone(skb_dst(skb));
	310	}
adf30907	311	}
1da177e4	312
d19d56dd	313
290b895e ED	314	/**
	315	* __skb_tunnel_rx - prepare skb for rx reinsert
	316	* @skb: buffer
	317	* @dev: tunnel device
	318	*
	319	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	320	* so make some cleanups. (no accounting done)
	321	*/
	322	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	323	{
	324	skb->dev = dev;
bdeab991 TH	325
	326	/*
	327	* Clear rxhash so that we can recalulate the hash for the
	328	* encapsulated packet, unless we have already determine the hash
	329	* over the L4 4-tuple.
	330	*/
	331	if (!skb->l4_rxhash)
	332	skb->rxhash = 0;
290b895e ED	333	skb_set_queue_mapping(skb, 0);
	334	skb_dst_drop(skb);
	335	nf_reset(skb);
	336	}
	337
d19d56dd ED	338	/**
	339	* skb_tunnel_rx - prepare skb for rx reinsert
	340	* @skb: buffer
	341	* @dev: tunnel device
	342	*
	343	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	344	* so make some cleanups, and perform accounting.
290b895e	345	* Note: this accounting is not SMP safe.
d19d56dd ED	346	*/
	347	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	348	{
d19d56dd ED	349	/* TODO : stats should be SMP safe */
	350	dev->stats.rx_packets++;
	351	dev->stats.rx_bytes += skb->len;
290b895e	352	__skb_tunnel_rx(skb, dev);
d19d56dd ED	353	}
d19d56dd ED	354
1da177e4 LT	355	/* Children define the path of the packet through the
	356	* Linux networking. Thus, destinations are stackable.
	357	*/
	358
8764ab2c	359	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	360	{
e433430a	361	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	362
8764ab2c	363	skb_dst_drop(skb);
1da177e4 LT	364	return child;
	365	}
	366
352e512c	367	extern int dst_discard(struct sk_buff *skb);
5c1e6aa3 DM	368	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5c1e6aa3 DM	369	int initial_ref, int initial_obsolete, int flags);
1da177e4 LT	370	extern void __dst_free(struct dst_entry * dst);
	371	extern struct dst_entry dst_destroy(struct dst_entry dst);
	372
	373	static inline void dst_free(struct dst_entry * dst)
	374	{
	375	if (dst->obsolete > 1)
	376	return;
	377	if (!atomic_read(&dst->__refcnt)) {
	378	dst = dst_destroy(dst);
	379	if (!dst)
	380	return;
	381	}
	382	__dst_free(dst);
	383	}
	384
	385	static inline void dst_rcu_free(struct rcu_head *head)
	386	{
	387	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	388	dst_free(dst);
	389	}
	390
	391	static inline void dst_confirm(struct dst_entry *dst)
	392	{
69cce1d1	393	if (dst) {
f2c31e32 ED	394	struct neighbour *n;
	395
	396	rcu_read_lock();
27217455	397	n = dst_get_neighbour_noref(dst);
69cce1d1	398	neigh_confirm(n);
f2c31e32	399	rcu_read_unlock();
69cce1d1	400	}
1da177e4 LT	401	}
1da177e4 LT	402
d3aaeb38 DM	403	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
	404	{
	405	return dst->ops->neigh_lookup(dst, daddr);
	406	}
	407
1da177e4 LT	408	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	409	{
adf30907	410	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	411	if (dst && dst->ops && dst->ops->link_failure)
	412	dst->ops->link_failure(skb);
	413	}
	414
	415	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	416	{
	417	unsigned long expires = jiffies + timeout;
	418
	419	if (expires == 0)
	420	expires = 1;
	421
	422	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	423	dst->expires = expires;
	424	}
	425
	426	/* Output packet to network from transport. */
	427	static inline int dst_output(struct sk_buff *skb)
	428	{
adf30907	429	return skb_dst(skb)->output(skb);
1da177e4 LT	430	}
	431
	432	/* Input packet from network to transport. */
	433	static inline int dst_input(struct sk_buff *skb)
	434	{
adf30907	435	return skb_dst(skb)->input(skb);
1da177e4 LT	436	}
	437
	438	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	439	{
	440	if (dst->obsolete)
	441	dst = dst->ops->check(dst, cookie);
	442	return dst;
	443	}
	444
	445	extern void dst_init(void);
	446
815f4e57 HX	447	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	448	enum {
80c0bc9e	449	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	450	};
815f4e57 HX	451
1da177e4 LT	452	struct flowi;
1da177e4 LT	453	#ifndef CONFIG_XFRM
452edd59 DM	454	static inline struct dst_entry xfrm_lookup(struct net net,
	455	struct dst_entry *dst_orig,
	456	const struct flowi fl, struct sock sk,
	457	int flags)
1da177e4	458	{
452edd59	459	return dst_orig;
1da177e4 LT	460	}
1da177e4 LT	461	#else
452edd59 DM	462	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	463	const struct flowi fl, struct sock sk,
	464	int flags);
1da177e4	465	#endif
1da177e4 LT	466
1da177e4 LT	467	#endif /* _NET_DST_H */