[mirror_ubuntu-bionic-kernel.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;
	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
#define DST_FAKE_RTABLE		0x0080
#define DST_XFRM_TUNNEL		0x0100

	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;
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;
f2c31e32	45	struct neighbour __rcu *_neighbour;
def8b4fa	46	#ifdef CONFIG_XFRM
1da177e4	47	struct xfrm_state *xfrm;
5635c10d ED	48	#else
5635c10d ED	49	void *__pad1;
def8b4fa	50	#endif
1da177e4 LT	51	int (input)(struct sk_buff);
	52	int (output)(struct sk_buff);
	53
f6b72b62 DM	54	int flags;
	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
62fa8a84 DM	65	short error;
	66	short obsolete;
	67	unsigned short header_len; /* more space at head required */
	68	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	69	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	70	__u32 tclassid;
5635c10d ED	71	#else
5635c10d ED	72	__u32 __pad2;
f1dd9c37 ZY	73	#endif
f1dd9c37 ZY	74
5635c10d ED	75	/*
	76	* Align __refcnt to a 64 bytes alignment
	77	* (L1_CACHE_SIZE would be too much)
	78	*/
	79	#ifdef CONFIG_64BIT
f6b72b62	80	long __pad_to_align_refcnt[2];
5635c10d	81	#endif
f1dd9c37 ZY	82	/*
	83	* __refcnt wants to be on a different cache line from
	84	* input/output/ops or performance tanks badly
	85	*/
1e19e02c ED	86	atomic_t __refcnt; /* client references */
1e19e02c ED	87	int __use;
f1dd9c37	88	unsigned long lastuse;
1e19e02c	89	union {
fc766e4c ED	90	struct dst_entry *next;
	91	struct rtable __rcu *rt_next;
	92	struct rt6_info *rt6_next;
	93	struct dn_route __rcu *dn_next;
1e19e02c	94	};
1da177e4 LT	95	};
1da177e4 LT	96
27217455	97	static inline struct neighbour dst_get_neighbour_noref(struct dst_entry dst)
69cce1d1	98	{
f2c31e32 ED	99	return rcu_dereference(dst->_neighbour);
	100	}
	101
27217455	102	static inline struct neighbour dst_get_neighbour_noref_raw(struct dst_entry dst)
f2c31e32 ED	103	{
f2c31e32 ED	104	return rcu_dereference_raw(dst->_neighbour);
69cce1d1 DM	105	}
	106
	107	static inline void dst_set_neighbour(struct dst_entry dst, struct neighbour neigh)
	108	{
f2c31e32	109	rcu_assign_pointer(dst->_neighbour, neigh);
69cce1d1 DM	110	}
69cce1d1 DM	111
62fa8a84	112	extern u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
725d1e1b	113	extern const u32 dst_default_metrics[RTAX_MAX];
62fa8a84 DM	114
	115	#define DST_METRICS_READ_ONLY 0x1UL
	116	#define __DST_METRICS_PTR(Y) \
	117	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	118	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	119
	120	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	121	{
	122	return dst->_metrics & DST_METRICS_READ_ONLY;
	123	}
	124
	125	extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
	126
	127	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	128	{
	129	unsigned long val = dst->_metrics;
	130	if (!(val & DST_METRICS_READ_ONLY))
	131	__dst_destroy_metrics_generic(dst, val);
	132	}
	133
	134	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	135	{
	136	unsigned long p = dst->_metrics;
	137
1f37070d SH	138	BUG_ON(!p);
1f37070d SH	139
62fa8a84 DM	140	if (p & DST_METRICS_READ_ONLY)
	141	return dst->ops->cow_metrics(dst, p);
	142	return __DST_METRICS_PTR(p);
	143	}
	144
	145	/* This may only be invoked before the entry has reached global
	146	* visibility.
	147	*/
	148	static inline void dst_init_metrics(struct dst_entry *dst,
	149	const u32 *src_metrics,
	150	bool read_only)
	151	{
	152	dst->_metrics = ((unsigned long) src_metrics) \|
	153	(read_only ? DST_METRICS_READ_ONLY : 0);
	154	}
	155
	156	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	157	{
	158	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	159
	160	if (dst_metrics) {
	161	u32 *src_metrics = DST_METRICS_PTR(src);
	162
	163	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	164	}
	165	}
	166
	167	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	168	{
	169	return DST_METRICS_PTR(dst);
	170	}
	171
1da177e4	172	static inline u32
5170ae82	173	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	174	{
62fa8a84 DM	175	u32 *p = DST_METRICS_PTR(dst);
	176
	177	return p[metric-1];
defb3519 DM	178	}
defb3519 DM	179
5170ae82 DM	180	static inline u32
	181	dst_metric(const struct dst_entry *dst, const int metric)
	182	{
0dbaee3b	183	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	184	metric == RTAX_ADVMSS \|\|
d33e4553 DM	185	metric == RTAX_MTU);
5170ae82 DM	186	return dst_metric_raw(dst, metric);
	187	}
	188
0dbaee3b DM	189	static inline u32
	190	dst_metric_advmss(const struct dst_entry *dst)
	191	{
	192	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	193
	194	if (!advmss)
	195	advmss = dst->ops->default_advmss(dst);
	196
	197	return advmss;
	198	}
	199
defb3519 DM	200	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	201	{
62fa8a84	202	u32 *p = dst_metrics_write_ptr(dst);
defb3519	203
62fa8a84 DM	204	if (p)
62fa8a84 DM	205	p[metric-1] = val;
1da177e4 LT	206	}
1da177e4 LT	207
0c3adfb8 GBY	208	static inline u32
	209	dst_feature(const struct dst_entry *dst, u32 feature)
	210	{
bb5b7c11	211	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	212	}
0c3adfb8 GBY	213
1da177e4 LT	214	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	215	{
618f9bc7	216	return dst->ops->mtu(dst);
1da177e4 LT	217	}
1da177e4 LT	218
c1e20f7c SH	219	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	220	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	221	{
	222	return msecs_to_jiffies(dst_metric(dst, metric));
	223	}
	224
	225	static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
	226	unsigned long rtt)
	227	{
defb3519	228	dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c SH	229	}
c1e20f7c SH	230
1da177e4 LT	231	static inline u32
	232	dst_allfrag(const struct dst_entry *dst)
	233	{
0c3adfb8	234	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	235	return ret;
	236	}
	237
	238	static inline int
d33e4553	239	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	240	{
	241	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	242	}
	243
	244	static inline void dst_hold(struct dst_entry * dst)
	245	{
5635c10d ED	246	/*
	247	* If your kernel compilation stops here, please check
	248	* __pad_to_align_refcnt declaration in struct dst_entry
	249	*/
	250	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	251	atomic_inc(&dst->__refcnt);
	252	}
	253
03f49f34 PE	254	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	255	{
	256	dst_hold(dst);
	257	dst->__use++;
	258	dst->lastuse = time;
	259	}
	260
7fee226a ED	261	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	262	{
	263	dst->__use++;
	264	dst->lastuse = time;
	265	}
	266
1da177e4 LT	267	static inline
	268	struct dst_entry * dst_clone(struct dst_entry * dst)
	269	{
	270	if (dst)
	271	atomic_inc(&dst->__refcnt);
	272	return dst;
	273	}
	274
8d330868	275	extern void dst_release(struct dst_entry *dst);
7fee226a ED	276
	277	static inline void refdst_drop(unsigned long refdst)
	278	{
	279	if (!(refdst & SKB_DST_NOREF))
	280	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	281	}
	282
	283	/**
	284	* skb_dst_drop - drops skb dst
	285	* @skb: buffer
	286	*
	287	* Drops dst reference count if a reference was taken.
	288	*/
adf30907 ED	289	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	290	{
7fee226a ED	291	if (skb->_skb_refdst) {
	292	refdst_drop(skb->_skb_refdst);
	293	skb->_skb_refdst = 0UL;
	294	}
	295	}
	296
	297	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	298	{
	299	nskb->_skb_refdst = oskb->_skb_refdst;
	300	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	301	dst_clone(skb_dst(nskb));
	302	}
	303
	304	/**
	305	* skb_dst_force - makes sure skb dst is refcounted
	306	* @skb: buffer
	307	*
	308	* If dst is not yet refcounted, let's do it
	309	*/
	310	static inline void skb_dst_force(struct sk_buff *skb)
	311	{
	312	if (skb_dst_is_noref(skb)) {
	313	WARN_ON(!rcu_read_lock_held());
	314	skb->_skb_refdst &= ~SKB_DST_NOREF;
	315	dst_clone(skb_dst(skb));
	316	}
adf30907	317	}
1da177e4	318
d19d56dd	319
290b895e ED	320	/**
	321	* __skb_tunnel_rx - prepare skb for rx reinsert
	322	* @skb: buffer
	323	* @dev: tunnel device
	324	*
	325	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	326	* so make some cleanups. (no accounting done)
	327	*/
	328	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	329	{
	330	skb->dev = dev;
bdeab991 TH	331
	332	/*
	333	* Clear rxhash so that we can recalulate the hash for the
	334	* encapsulated packet, unless we have already determine the hash
	335	* over the L4 4-tuple.
	336	*/
	337	if (!skb->l4_rxhash)
	338	skb->rxhash = 0;
290b895e ED	339	skb_set_queue_mapping(skb, 0);
	340	skb_dst_drop(skb);
	341	nf_reset(skb);
	342	}
	343
d19d56dd ED	344	/**
	345	* skb_tunnel_rx - prepare skb for rx reinsert
	346	* @skb: buffer
	347	* @dev: tunnel device
	348	*
	349	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	350	* so make some cleanups, and perform accounting.
290b895e	351	* Note: this accounting is not SMP safe.
d19d56dd ED	352	*/
	353	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev)
	354	{
d19d56dd ED	355	/* TODO : stats should be SMP safe */
	356	dev->stats.rx_packets++;
	357	dev->stats.rx_bytes += skb->len;
290b895e	358	__skb_tunnel_rx(skb, dev);
d19d56dd ED	359	}
d19d56dd ED	360
1da177e4 LT	361	/* Children define the path of the packet through the
	362	* Linux networking. Thus, destinations are stackable.
	363	*/
	364
8764ab2c	365	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	366	{
e433430a	367	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	368
8764ab2c	369	skb_dst_drop(skb);
1da177e4 LT	370	return child;
	371	}
	372
352e512c	373	extern int dst_discard(struct sk_buff *skb);
5c1e6aa3 DM	374	extern void dst_alloc(struct dst_ops ops, struct net_device *dev,
5c1e6aa3 DM	375	int initial_ref, int initial_obsolete, int flags);
1da177e4 LT	376	extern void __dst_free(struct dst_entry * dst);
	377	extern struct dst_entry dst_destroy(struct dst_entry dst);
	378
	379	static inline void dst_free(struct dst_entry * dst)
	380	{
	381	if (dst->obsolete > 1)
	382	return;
	383	if (!atomic_read(&dst->__refcnt)) {
	384	dst = dst_destroy(dst);
	385	if (!dst)
	386	return;
	387	}
	388	__dst_free(dst);
	389	}
	390
	391	static inline void dst_rcu_free(struct rcu_head *head)
	392	{
	393	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	394	dst_free(dst);
	395	}
	396
	397	static inline void dst_confirm(struct dst_entry *dst)
	398	{
69cce1d1	399	if (dst) {
f2c31e32 ED	400	struct neighbour *n;
	401
	402	rcu_read_lock();
27217455	403	n = dst_get_neighbour_noref(dst);
69cce1d1	404	neigh_confirm(n);
f2c31e32	405	rcu_read_unlock();
69cce1d1	406	}
1da177e4 LT	407	}
1da177e4 LT	408
d3aaeb38 DM	409	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
	410	{
	411	return dst->ops->neigh_lookup(dst, daddr);
	412	}
	413
1da177e4 LT	414	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	415	{
adf30907	416	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	417	if (dst && dst->ops && dst->ops->link_failure)
	418	dst->ops->link_failure(skb);
	419	}
	420
	421	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	422	{
	423	unsigned long expires = jiffies + timeout;
	424
	425	if (expires == 0)
	426	expires = 1;
	427
	428	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	429	dst->expires = expires;
	430	}
	431
	432	/* Output packet to network from transport. */
	433	static inline int dst_output(struct sk_buff *skb)
	434	{
adf30907	435	return skb_dst(skb)->output(skb);
1da177e4 LT	436	}
	437
	438	/* Input packet from network to transport. */
	439	static inline int dst_input(struct sk_buff *skb)
	440	{
adf30907	441	return skb_dst(skb)->input(skb);
1da177e4 LT	442	}
	443
	444	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	445	{
	446	if (dst->obsolete)
	447	dst = dst->ops->check(dst, cookie);
	448	return dst;
	449	}
	450
	451	extern void dst_init(void);
	452
815f4e57 HX	453	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	454	enum {
80c0bc9e	455	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	456	};
815f4e57 HX	457
1da177e4 LT	458	struct flowi;
1da177e4 LT	459	#ifndef CONFIG_XFRM
452edd59 DM	460	static inline struct dst_entry xfrm_lookup(struct net net,
	461	struct dst_entry *dst_orig,
	462	const struct flowi fl, struct sock sk,
	463	int flags)
1da177e4	464	{
452edd59	465	return dst_orig;
1da177e4 LT	466	}
1da177e4 LT	467	#else
452edd59 DM	468	extern struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	469	const struct flowi fl, struct sock sk,
	470	int flags);
1da177e4	471	#endif
1da177e4 LT	472
1da177e4 LT	473	#endif /* _NET_DST_H */