[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;
	union {
		unsigned long           expires;
		/* point to where the dst_entry copied from */
		struct dst_entry        *from;
	};
	struct dst_entry	*path;
	void			*__pad0;
#ifdef CONFIG_XFRM
	struct xfrm_state	*xfrm;
#else
	void			*__pad1;
#endif
	int			(*input)(struct sk_buff *);
	int			(*output)(struct sk_buff *);

	unsigned short		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
#define DST_FAKE_RTABLE		0x0080
#define DST_XFRM_TUNNEL		0x0100

	unsigned short		pending_confirm;

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

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

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

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

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

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

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

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

	BUG_ON(!p);

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

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

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

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

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

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

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

	return p[metric-1];
}

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

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

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

	return advmss;
}

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

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

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

static inline u32 dst_mtu(const struct dst_entry *dst)
{
	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 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,
		       unsigned short 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)
{
	dst->pending_confirm = 1;
}

static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
				   struct sk_buff *skb)
{
	struct hh_cache *hh;

	if (unlikely(dst->pending_confirm)) {
		n->confirmed = jiffies;
		dst->pending_confirm = 0;
	}

	hh = &n->hh;
	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
		return neigh_hh_output(hh, skb);
	else
		return n->output(n, skb);
}

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

static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
						     struct sk_buff *skb)
{
	return dst->ops->neigh_lookup(dst, skb, NULL);
}

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;
1716a961 G	39	union {
	40	unsigned long expires;
	41	/* point to where the dst_entry copied from */
	42	struct dst_entry *from;
	43	};
f1dd9c37	44	struct dst_entry *path;
36bdbcae	45	void *__pad0;
def8b4fa	46	#ifdef CONFIG_XFRM
1da177e4	47	struct xfrm_state *xfrm;
5635c10d ED	48	#else
5635c10d ED	49	void *__pad1;
def8b4fa	50	#endif
7f95e188 EZ	51	int (input)(struct sk_buff );
7f95e188 EZ	52	int (output)(struct sk_buff );
1da177e4	53
5110effe	54	unsigned short flags;
f6b72b62 DM	55	#define DST_HOST 0x0001
	56	#define DST_NOXFRM 0x0002
	57	#define DST_NOPOLICY 0x0004
	58	#define DST_NOHASH 0x0008
	59	#define DST_NOCACHE 0x0010
	60	#define DST_NOCOUNT 0x0020
e688a604	61	#define DST_NOPEER 0x0040
a881e963	62	#define DST_FAKE_RTABLE 0x0080
0c183379	63	#define DST_XFRM_TUNNEL 0x0100
f6b72b62	64
5110effe DM	65	unsigned short pending_confirm;
5110effe DM	66
62fa8a84 DM	67	short error;
	68	short obsolete;
	69	unsigned short header_len; /* more space at head required */
	70	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	71	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	72	__u32 tclassid;
5635c10d ED	73	#else
5635c10d ED	74	__u32 __pad2;
f1dd9c37 ZY	75	#endif
f1dd9c37 ZY	76
5635c10d ED	77	/*
	78	* Align __refcnt to a 64 bytes alignment
	79	* (L1_CACHE_SIZE would be too much)
	80	*/
	81	#ifdef CONFIG_64BIT
f6b72b62	82	long __pad_to_align_refcnt[2];
5635c10d	83	#endif
f1dd9c37 ZY	84	/*
	85	* __refcnt wants to be on a different cache line from
	86	* input/output/ops or performance tanks badly
	87	*/
1e19e02c ED	88	atomic_t __refcnt; /* client references */
1e19e02c ED	89	int __use;
f1dd9c37	90	unsigned long lastuse;
1e19e02c	91	union {
fc766e4c ED	92	struct dst_entry *next;
	93	struct rtable __rcu *rt_next;
	94	struct rt6_info *rt6_next;
	95	struct dn_route __rcu *dn_next;
1e19e02c	96	};
1da177e4 LT	97	};
1da177e4 LT	98
62fa8a84	99	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	100	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	101
	102	#define DST_METRICS_READ_ONLY 0x1UL
	103	#define __DST_METRICS_PTR(Y) \
	104	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	105	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	106
	107	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	108	{
	109	return dst->_metrics & DST_METRICS_READ_ONLY;
	110	}
	111
	112	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	113
	114	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	115	{
	116	unsigned long val = dst->_metrics;
	117	if (!(val & DST_METRICS_READ_ONLY))
	118	__dst_destroy_metrics_generic(dst, val);
	119	}
	120
	121	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	122	{
	123	unsigned long p = dst->_metrics;
	124
1f37070d SH	125	BUG_ON(!p);
1f37070d SH	126
62fa8a84 DM	127	if (p & DST_METRICS_READ_ONLY)
	128	return dst->ops->cow_metrics(dst, p);
	129	return __DST_METRICS_PTR(p);
	130	}
	131
	132	/* This may only be invoked before the entry has reached global
	133	* visibility.
	134	*/
	135	static inline void dst_init_metrics(struct dst_entry *dst,
	136	const u32 *src_metrics,
	137	bool read_only)
	138	{
	139	dst->_metrics = ((unsigned long) src_metrics) \|
	140	(read_only ? DST_METRICS_READ_ONLY : 0);
	141	}
	142
	143	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	144	{
	145	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	146
	147	if (dst_metrics) {
	148	u32 *src_metrics = DST_METRICS_PTR(src);
	149
	150	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	151	}
	152	}
	153
	154	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	155	{
	156	return DST_METRICS_PTR(dst);
	157	}
	158
1da177e4	159	static inline u32
5170ae82	160	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	161	{
62fa8a84 DM	162	u32 *p = DST_METRICS_PTR(dst);
	163
	164	return p[metric-1];
defb3519 DM	165	}
defb3519 DM	166
5170ae82 DM	167	static inline u32
	168	dst_metric(const struct dst_entry *dst, const int metric)
	169	{
0dbaee3b	170	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	171	metric == RTAX_ADVMSS \|\|
d33e4553 DM	172	metric == RTAX_MTU);
5170ae82 DM	173	return dst_metric_raw(dst, metric);
	174	}
	175
0dbaee3b DM	176	static inline u32
	177	dst_metric_advmss(const struct dst_entry *dst)
	178	{
	179	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	180
	181	if (!advmss)
	182	advmss = dst->ops->default_advmss(dst);
	183
	184	return advmss;
	185	}
	186
defb3519 DM	187	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	188	{
62fa8a84	189	u32 *p = dst_metrics_write_ptr(dst);
defb3519	190
62fa8a84 DM	191	if (p)
62fa8a84 DM	192	p[metric-1] = val;
1da177e4 LT	193	}
1da177e4 LT	194
0c3adfb8 GBY	195	static inline u32
	196	dst_feature(const struct dst_entry *dst, u32 feature)
	197	{
bb5b7c11	198	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	199	}
0c3adfb8 GBY	200
1da177e4 LT	201	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	202	{
618f9bc7	203	return dst->ops->mtu(dst);
1da177e4 LT	204	}
1da177e4 LT	205
c1e20f7c SH	206	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	207	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	208	{
	209	return msecs_to_jiffies(dst_metric(dst, metric));
	210	}
	211
1da177e4 LT	212	static inline u32
	213	dst_allfrag(const struct dst_entry *dst)
	214	{
0c3adfb8	215	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	216	return ret;
	217	}
	218
	219	static inline int
d33e4553	220	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	221	{
	222	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	223	}
	224
7f95e188	225	static inline void dst_hold(struct dst_entry *dst)
1da177e4	226	{
5635c10d ED	227	/*
	228	* If your kernel compilation stops here, please check
	229	* __pad_to_align_refcnt declaration in struct dst_entry
	230	*/
	231	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	232	atomic_inc(&dst->__refcnt);
	233	}
	234
03f49f34 PE	235	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	236	{
	237	dst_hold(dst);
	238	dst->__use++;
	239	dst->lastuse = time;
	240	}
	241
7fee226a ED	242	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	243	{
	244	dst->__use++;
	245	dst->lastuse = time;
	246	}
	247
7f95e188	248	static inline struct dst_entry dst_clone(struct dst_entry dst)
1da177e4 LT	249	{
	250	if (dst)
	251	atomic_inc(&dst->__refcnt);
	252	return dst;
	253	}
	254
8d330868	255	extern void dst_release(struct dst_entry *dst);
7fee226a ED	256
	257	static inline void refdst_drop(unsigned long refdst)
	258	{
	259	if (!(refdst & SKB_DST_NOREF))
	260	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	261	}
	262
	263	/**
	264	* skb_dst_drop - drops skb dst
	265	* @skb: buffer
	266	*
	267	* Drops dst reference count if a reference was taken.
	268	*/
adf30907 ED	269	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	270	{
7fee226a ED	271	if (skb->_skb_refdst) {
	272	refdst_drop(skb->_skb_refdst);
	273	skb->_skb_refdst = 0UL;
	274	}
	275	}
	276
	277	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	278	{
	279	nskb->_skb_refdst = oskb->_skb_refdst;
	280	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	281	dst_clone(skb_dst(nskb));
	282	}
	283
	284	/**
	285	* skb_dst_force - makes sure skb dst is refcounted
	286	* @skb: buffer
	287	*
	288	* If dst is not yet refcounted, let's do it
	289	*/
	290	static inline void skb_dst_force(struct sk_buff *skb)
	291	{
	292	if (skb_dst_is_noref(skb)) {
	293	WARN_ON(!rcu_read_lock_held());
	294	skb->_skb_refdst &= ~SKB_DST_NOREF;
	295	dst_clone(skb_dst(skb));
	296	}
adf30907	297	}
1da177e4	298
d19d56dd	299
290b895e ED	300	/**
	301	* __skb_tunnel_rx - prepare skb for rx reinsert
	302	* @skb: buffer
	303	* @dev: tunnel device
	304	*
	305	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	306	* so make some cleanups. (no accounting done)
	307	*/
	308	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	309	{
	310	skb->dev = dev;
bdeab991 TH	311
	312	/*
	313	* Clear rxhash so that we can recalulate the hash for the
	314	* encapsulated packet, unless we have already determine the hash
	315	* over the L4 4-tuple.
	316	*/
	317	if (!skb->l4_rxhash)
	318	skb->rxhash = 0;
290b895e ED	319	skb_set_queue_mapping(skb, 0);
	320	skb_dst_drop(skb);
	321	nf_reset(skb);
	322	}
	323
d19d56dd ED	324	/**
	325	* skb_tunnel_rx - prepare skb for rx reinsert
	326	* @skb: buffer
	327	* @dev: tunnel device
	328	*
	329	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	330	* so make some cleanups, and perform accounting.
290b895e	331	* Note: this accounting is not SMP safe.
d19d56dd ED	332	*/
	333	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	334	{
d19d56dd ED	335	/* TODO : stats should be SMP safe */
	336	dev->stats.rx_packets++;
	337	dev->stats.rx_bytes += skb->len;
290b895e	338	__skb_tunnel_rx(skb, dev);
d19d56dd ED	339	}
d19d56dd ED	340
1da177e4 LT	341	/* Children define the path of the packet through the
	342	* Linux networking. Thus, destinations are stackable.
	343	*/
	344
8764ab2c	345	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	346	{
e433430a	347	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	348
8764ab2c	349	skb_dst_drop(skb);
1da177e4 LT	350	return child;
	351	}
	352
352e512c	353	extern int dst_discard(struct sk_buff *skb);
7f95e188	354	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5110effe DM	355	int initial_ref, int initial_obsolete,
5110effe DM	356	unsigned short flags);
7f95e188 EZ	357	extern void __dst_free(struct dst_entry *dst);
7f95e188 EZ	358	extern struct dst_entry dst_destroy(struct dst_entry dst);
1da177e4	359
7f95e188	360	static inline void dst_free(struct dst_entry *dst)
1da177e4 LT	361	{
	362	if (dst->obsolete > 1)
	363	return;
	364	if (!atomic_read(&dst->__refcnt)) {
	365	dst = dst_destroy(dst);
	366	if (!dst)
	367	return;
	368	}
	369	__dst_free(dst);
	370	}
	371
	372	static inline void dst_rcu_free(struct rcu_head *head)
	373	{
	374	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	375	dst_free(dst);
	376	}
	377
	378	static inline void dst_confirm(struct dst_entry *dst)
	379	{
5110effe DM	380	dst->pending_confirm = 1;
5110effe DM	381	}
f2c31e32	382
5110effe DM	383	static inline int dst_neigh_output(struct dst_entry dst, struct neighbour n,
	384	struct sk_buff *skb)
	385	{
	386	struct hh_cache *hh;
	387
	388	if (unlikely(dst->pending_confirm)) {
	389	n->confirmed = jiffies;
	390	dst->pending_confirm = 0;
69cce1d1	391	}
5110effe DM	392
	393	hh = &n->hh;
	394	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
	395	return neigh_hh_output(hh, skb);
	396	else
	397	return n->output(n, skb);
1da177e4 LT	398	}
1da177e4 LT	399
d3aaeb38 DM	400	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
d3aaeb38 DM	401	{
f894cbf8 DM	402	return dst->ops->neigh_lookup(dst, NULL, daddr);
	403	}
	404
	405	static inline struct neighbour dst_neigh_lookup_skb(const struct dst_entry dst,
	406	struct sk_buff *skb)
	407	{
	408	return dst->ops->neigh_lookup(dst, skb, NULL);
d3aaeb38 DM	409	}
d3aaeb38 DM	410
1da177e4 LT	411	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	412	{
adf30907	413	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	414	if (dst && dst->ops && dst->ops->link_failure)
	415	dst->ops->link_failure(skb);
	416	}
	417
	418	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	419	{
	420	unsigned long expires = jiffies + timeout;
	421
	422	if (expires == 0)
	423	expires = 1;
	424
	425	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	426	dst->expires = expires;
	427	}
	428
	429	/* Output packet to network from transport. */
	430	static inline int dst_output(struct sk_buff *skb)
	431	{
adf30907	432	return skb_dst(skb)->output(skb);
1da177e4 LT	433	}
	434
	435	/* Input packet from network to transport. */
	436	static inline int dst_input(struct sk_buff *skb)
	437	{
adf30907	438	return skb_dst(skb)->input(skb);
1da177e4 LT	439	}
	440
	441	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	442	{
	443	if (dst->obsolete)
	444	dst = dst->ops->check(dst, cookie);
	445	return dst;
	446	}
	447
	448	extern void dst_init(void);
	449
815f4e57 HX	450	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	451	enum {
80c0bc9e	452	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	453	};
815f4e57 HX	454
1da177e4 LT	455	struct flowi;
1da177e4 LT	456	#ifndef CONFIG_XFRM
452edd59 DM	457	static inline struct dst_entry xfrm_lookup(struct net net,
	458	struct dst_entry *dst_orig,
	459	const struct flowi fl, struct sock sk,
	460	int flags)
1da177e4	461	{
452edd59	462	return dst_orig;
1da177e4 LT	463	}
1da177e4 LT	464	#else
452edd59 DM	465	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	466	const struct flowi fl, struct sock sk,
	467	int flags);
1da177e4	468	#endif
1da177e4 LT	469
1da177e4 LT	470	#endif /* _NET_DST_H */