[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;
	unsigned long           expires;
	struct dst_entry	*path;
	struct dst_entry	*from;
#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_FAKE_RTABLE		0x0040
#define DST_XFRM_TUNNEL		0x0080
#define DST_XFRM_QUEUE		0x0100

	unsigned short		pending_confirm;

	short			error;

	/* A non-zero value of dst->obsolete forces by-hand validation
	 * of the route entry.  Positive values are set by the generic
	 * dst layer to indicate that the entry has been forcefully
	 * destroyed.
	 *
	 * Negative values are used by the implementation layer code to
	 * force invocation of the dst_ops->check() method.
	 */
	short			obsolete;
#define DST_OBSOLETE_NONE	0
#define DST_OBSOLETE_DEAD	2
#define DST_OBSOLETE_FORCE_CHK	-1
#define DST_OBSOLETE_KILL	-2
	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;
	};
};

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

#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;
}

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;
}

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
 *	@net: netns for packet i/o
 *
 *	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,
				   struct net *net)
{
	skb->dev = dev;

	/*
	 * Clear hash so that we can recalulate the hash for the
	 * encapsulated packet, unless we have already determine the hash
	 * over the L4 4-tuple.
	 */
	skb_clear_hash_if_not_l4(skb);
	skb_set_queue_mapping(skb, 0);
	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
}

/**
 *	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,
				 struct net *net)
{
	/* TODO : stats should be SMP safe */
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += skb->len;
	__skb_tunnel_rx(skb, dev, net);
}

/* 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;
}

int dst_discard(struct sk_buff *skb);
void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
		int initial_obsolete, unsigned short flags);
void __dst_free(struct dst_entry *dst);
struct dst_entry *dst_destroy(struct dst_entry *dst);

static inline void dst_free(struct dst_entry *dst)
{
	if (dst->obsolete > 0)
		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)
{
	const struct hh_cache *hh;

	if (dst->pending_confirm) {
		unsigned long now = jiffies;

		dst->pending_confirm = 0;
		/* avoid dirtying neighbour */
		if (n->confirmed != now)
			n->confirmed = now;
	}

	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)
{
	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
	return IS_ERR(n) ? NULL : n;
}

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

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;
}

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;
} 

static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
{
	return NULL;
}

#else
struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
			      const struct flowi *fl, struct sock *sk,
			      int flags);

/* skb attached with this dst needs transformation if dst->xfrm is valid */
static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
{
	return dst->xfrm;
}
#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;
ecd98837	39	unsigned long expires;
f1dd9c37	40	struct dst_entry *path;
ecd98837	41	struct dst_entry *from;
def8b4fa	42	#ifdef CONFIG_XFRM
1da177e4	43	struct xfrm_state *xfrm;
5635c10d ED	44	#else
5635c10d ED	45	void *__pad1;
def8b4fa	46	#endif
7f95e188 EZ	47	int (input)(struct sk_buff );
7f95e188 EZ	48	int (output)(struct sk_buff );
1da177e4	49
5110effe	50	unsigned short flags;
f6b72b62 DM	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
e90c1483 HFS	57	#define DST_FAKE_RTABLE 0x0040
	58	#define DST_XFRM_TUNNEL 0x0080
	59	#define DST_XFRM_QUEUE 0x0100
f6b72b62	60
5110effe DM	61	unsigned short pending_confirm;
5110effe DM	62
62fa8a84	63	short error;
f5b0a874 DM	64
	65	/* A non-zero value of dst->obsolete forces by-hand validation
	66	* of the route entry. Positive values are set by the generic
	67	* dst layer to indicate that the entry has been forcefully
	68	* destroyed.
	69	*
	70	* Negative values are used by the implementation layer code to
	71	* force invocation of the dst_ops->check() method.
	72	*/
62fa8a84	73	short obsolete;
f5b0a874 DM	74	#define DST_OBSOLETE_NONE 0
	75	#define DST_OBSOLETE_DEAD 2
	76	#define DST_OBSOLETE_FORCE_CHK -1
ceb33206	77	#define DST_OBSOLETE_KILL -2
62fa8a84 DM	78	unsigned short header_len; /* more space at head required */
62fa8a84 DM	79	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	80	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	81	__u32 tclassid;
5635c10d ED	82	#else
5635c10d ED	83	__u32 __pad2;
f1dd9c37 ZY	84	#endif
f1dd9c37 ZY	85
5635c10d ED	86	/*
	87	* Align __refcnt to a 64 bytes alignment
	88	* (L1_CACHE_SIZE would be too much)
	89	*/
	90	#ifdef CONFIG_64BIT
f6b72b62	91	long __pad_to_align_refcnt[2];
5635c10d	92	#endif
f1dd9c37 ZY	93	/*
	94	* __refcnt wants to be on a different cache line from
	95	* input/output/ops or performance tanks badly
	96	*/
1e19e02c ED	97	atomic_t __refcnt; /* client references */
1e19e02c ED	98	int __use;
f1dd9c37	99	unsigned long lastuse;
1e19e02c	100	union {
fc766e4c ED	101	struct dst_entry *next;
	102	struct rtable __rcu *rt_next;
	103	struct rt6_info *rt6_next;
	104	struct dn_route __rcu *dn_next;
1e19e02c	105	};
1da177e4 LT	106	};
1da177e4 LT	107
a4023dd0	108	u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
a37e6e34	109	extern const u32 dst_default_metrics[];
62fa8a84 DM	110
	111	#define DST_METRICS_READ_ONLY 0x1UL
	112	#define __DST_METRICS_PTR(Y) \
	113	((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
	114	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	115
	116	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	117	{
	118	return dst->_metrics & DST_METRICS_READ_ONLY;
	119	}
	120
a4023dd0	121	void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
62fa8a84 DM	122
	123	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	124	{
	125	unsigned long val = dst->_metrics;
	126	if (!(val & DST_METRICS_READ_ONLY))
	127	__dst_destroy_metrics_generic(dst, val);
	128	}
	129
	130	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	131	{
	132	unsigned long p = dst->_metrics;
	133
1f37070d SH	134	BUG_ON(!p);
1f37070d SH	135
62fa8a84 DM	136	if (p & DST_METRICS_READ_ONLY)
	137	return dst->ops->cow_metrics(dst, p);
	138	return __DST_METRICS_PTR(p);
	139	}
	140
	141	/* This may only be invoked before the entry has reached global
	142	* visibility.
	143	*/
	144	static inline void dst_init_metrics(struct dst_entry *dst,
	145	const u32 *src_metrics,
	146	bool read_only)
	147	{
	148	dst->_metrics = ((unsigned long) src_metrics) \|
	149	(read_only ? DST_METRICS_READ_ONLY : 0);
	150	}
	151
	152	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	153	{
	154	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	155
	156	if (dst_metrics) {
	157	u32 *src_metrics = DST_METRICS_PTR(src);
	158
	159	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	160	}
	161	}
	162
	163	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	164	{
	165	return DST_METRICS_PTR(dst);
	166	}
	167
1da177e4	168	static inline u32
5170ae82	169	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	170	{
62fa8a84 DM	171	u32 *p = DST_METRICS_PTR(dst);
	172
	173	return p[metric-1];
defb3519 DM	174	}
defb3519 DM	175
5170ae82 DM	176	static inline u32
	177	dst_metric(const struct dst_entry *dst, const int metric)
	178	{
0dbaee3b	179	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	180	metric == RTAX_ADVMSS \|\|
d33e4553 DM	181	metric == RTAX_MTU);
5170ae82 DM	182	return dst_metric_raw(dst, metric);
	183	}
	184
0dbaee3b DM	185	static inline u32
	186	dst_metric_advmss(const struct dst_entry *dst)
	187	{
	188	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	189
	190	if (!advmss)
	191	advmss = dst->ops->default_advmss(dst);
	192
	193	return advmss;
	194	}
	195
defb3519 DM	196	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	197	{
62fa8a84	198	u32 *p = dst_metrics_write_ptr(dst);
defb3519	199
62fa8a84 DM	200	if (p)
62fa8a84 DM	201	p[metric-1] = val;
1da177e4 LT	202	}
1da177e4 LT	203
0c3adfb8 GBY	204	static inline u32
	205	dst_feature(const struct dst_entry *dst, u32 feature)
	206	{
bb5b7c11	207	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	208	}
0c3adfb8 GBY	209
1da177e4 LT	210	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	211	{
618f9bc7	212	return dst->ops->mtu(dst);
1da177e4 LT	213	}
1da177e4 LT	214
c1e20f7c SH	215	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	216	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	217	{
	218	return msecs_to_jiffies(dst_metric(dst, metric));
	219	}
	220
1da177e4 LT	221	static inline u32
	222	dst_allfrag(const struct dst_entry *dst)
	223	{
0c3adfb8	224	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	225	return ret;
	226	}
	227
	228	static inline int
d33e4553	229	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	230	{
	231	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	232	}
	233
7f95e188	234	static inline void dst_hold(struct dst_entry *dst)
1da177e4	235	{
5635c10d ED	236	/*
	237	* If your kernel compilation stops here, please check
	238	* __pad_to_align_refcnt declaration in struct dst_entry
	239	*/
	240	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	241	atomic_inc(&dst->__refcnt);
	242	}
	243
03f49f34 PE	244	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	245	{
	246	dst_hold(dst);
	247	dst->__use++;
	248	dst->lastuse = time;
	249	}
	250
7fee226a ED	251	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	252	{
	253	dst->__use++;
	254	dst->lastuse = time;
	255	}
	256
7f95e188	257	static inline struct dst_entry dst_clone(struct dst_entry dst)
1da177e4 LT	258	{
	259	if (dst)
	260	atomic_inc(&dst->__refcnt);
	261	return dst;
	262	}
	263
a4023dd0	264	void dst_release(struct dst_entry *dst);
7fee226a ED	265
	266	static inline void refdst_drop(unsigned long refdst)
	267	{
	268	if (!(refdst & SKB_DST_NOREF))
	269	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	270	}
	271
	272	/**
	273	* skb_dst_drop - drops skb dst
	274	* @skb: buffer
	275	*
	276	* Drops dst reference count if a reference was taken.
	277	*/
adf30907 ED	278	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	279	{
7fee226a ED	280	if (skb->_skb_refdst) {
	281	refdst_drop(skb->_skb_refdst);
	282	skb->_skb_refdst = 0UL;
	283	}
	284	}
	285
	286	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	287	{
	288	nskb->_skb_refdst = oskb->_skb_refdst;
	289	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	290	dst_clone(skb_dst(nskb));
	291	}
	292
	293	/**
	294	* skb_dst_force - makes sure skb dst is refcounted
	295	* @skb: buffer
	296	*
	297	* If dst is not yet refcounted, let's do it
	298	*/
	299	static inline void skb_dst_force(struct sk_buff *skb)
	300	{
	301	if (skb_dst_is_noref(skb)) {
	302	WARN_ON(!rcu_read_lock_held());
	303	skb->_skb_refdst &= ~SKB_DST_NOREF;
	304	dst_clone(skb_dst(skb));
	305	}
adf30907	306	}
1da177e4	307
d19d56dd	308
290b895e ED	309	/**
	310	* __skb_tunnel_rx - prepare skb for rx reinsert
	311	* @skb: buffer
	312	* @dev: tunnel device
ea23192e	313	* @net: netns for packet i/o
290b895e ED	314	*
	315	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	316	* so make some cleanups. (no accounting done)
	317	*/
ea23192e ND	318	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	319	struct net *net)
290b895e ED	320	{
290b895e ED	321	skb->dev = dev;
bdeab991 TH	322
bdeab991 TH	323	/*
7539fadc	324	* Clear hash so that we can recalulate the hash for the
bdeab991 TH	325	* encapsulated packet, unless we have already determine the hash
	326	* over the L4 4-tuple.
	327	*/
7539fadc	328	skb_clear_hash_if_not_l4(skb);
290b895e	329	skb_set_queue_mapping(skb, 0);
ea23192e	330	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
290b895e ED	331	}
290b895e ED	332
d19d56dd ED	333	/**
	334	* skb_tunnel_rx - prepare skb for rx reinsert
	335	* @skb: buffer
	336	* @dev: tunnel device
	337	*
	338	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	339	* so make some cleanups, and perform accounting.
290b895e	340	* Note: this accounting is not SMP safe.
d19d56dd	341	*/
ea23192e ND	342	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	343	struct net *net)
d19d56dd	344	{
d19d56dd ED	345	/* TODO : stats should be SMP safe */
	346	dev->stats.rx_packets++;
	347	dev->stats.rx_bytes += skb->len;
ea23192e	348	__skb_tunnel_rx(skb, dev, net);
d19d56dd ED	349	}
d19d56dd ED	350
1da177e4 LT	351	/* Children define the path of the packet through the
	352	* Linux networking. Thus, destinations are stackable.
	353	*/
	354
8764ab2c	355	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	356	{
e433430a	357	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	358
8764ab2c	359	skb_dst_drop(skb);
1da177e4 LT	360	return child;
	361	}
	362
a4023dd0 JP	363	int dst_discard(struct sk_buff *skb);
	364	void dst_alloc(struct dst_ops ops, struct net_device *dev, int initial_ref,
	365	int initial_obsolete, unsigned short flags);
	366	void __dst_free(struct dst_entry *dst);
	367	struct dst_entry dst_destroy(struct dst_entry dst);
1da177e4	368
7f95e188	369	static inline void dst_free(struct dst_entry *dst)
1da177e4	370	{
f5b0a874	371	if (dst->obsolete > 0)
1da177e4 LT	372	return;
	373	if (!atomic_read(&dst->__refcnt)) {
	374	dst = dst_destroy(dst);
	375	if (!dst)
	376	return;
	377	}
	378	__dst_free(dst);
	379	}
	380
	381	static inline void dst_rcu_free(struct rcu_head *head)
	382	{
	383	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	384	dst_free(dst);
	385	}
	386
	387	static inline void dst_confirm(struct dst_entry *dst)
	388	{
5110effe DM	389	dst->pending_confirm = 1;
5110effe DM	390	}
f2c31e32	391
5110effe DM	392	static inline int dst_neigh_output(struct dst_entry dst, struct neighbour n,
	393	struct sk_buff *skb)
	394	{
425f09ab ED	395	const struct hh_cache *hh;
	396
	397	if (dst->pending_confirm) {
	398	unsigned long now = jiffies;
5110effe	399
5110effe	400	dst->pending_confirm = 0;
425f09ab ED	401	/* avoid dirtying neighbour */
	402	if (n->confirmed != now)
	403	n->confirmed = now;
69cce1d1	404	}
5110effe DM	405
	406	hh = &n->hh;
	407	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
	408	return neigh_hh_output(hh, skb);
	409	else
	410	return n->output(n, skb);
1da177e4 LT	411	}
1da177e4 LT	412
d3aaeb38 DM	413	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
d3aaeb38 DM	414	{
aaa0c23c ZZ	415	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
aaa0c23c ZZ	416	return IS_ERR(n) ? NULL : n;
f894cbf8 DM	417	}
	418
	419	static inline struct neighbour dst_neigh_lookup_skb(const struct dst_entry dst,
	420	struct sk_buff *skb)
	421	{
aaa0c23c ZZ	422	struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
aaa0c23c ZZ	423	return IS_ERR(n) ? NULL : n;
d3aaeb38 DM	424	}
d3aaeb38 DM	425
1da177e4 LT	426	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	427	{
adf30907	428	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	429	if (dst && dst->ops && dst->ops->link_failure)
	430	dst->ops->link_failure(skb);
	431	}
	432
	433	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	434	{
	435	unsigned long expires = jiffies + timeout;
	436
	437	if (expires == 0)
	438	expires = 1;
	439
	440	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	441	dst->expires = expires;
	442	}
	443
	444	/* Output packet to network from transport. */
	445	static inline int dst_output(struct sk_buff *skb)
	446	{
adf30907	447	return skb_dst(skb)->output(skb);
1da177e4 LT	448	}
	449
	450	/* Input packet from network to transport. */
	451	static inline int dst_input(struct sk_buff *skb)
	452	{
adf30907	453	return skb_dst(skb)->input(skb);
1da177e4 LT	454	}
	455
	456	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	457	{
	458	if (dst->obsolete)
	459	dst = dst->ops->check(dst, cookie);
	460	return dst;
	461	}
	462
a4023dd0	463	void dst_init(void);
1da177e4	464
815f4e57 HX	465	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	466	enum {
80c0bc9e	467	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	468	};
815f4e57 HX	469
1da177e4 LT	470	struct flowi;
1da177e4 LT	471	#ifndef CONFIG_XFRM
452edd59 DM	472	static inline struct dst_entry xfrm_lookup(struct net net,
	473	struct dst_entry *dst_orig,
	474	const struct flowi fl, struct sock sk,
	475	int flags)
1da177e4	476	{
452edd59	477	return dst_orig;
1da177e4	478	}
e87b3998 VY	479
	480	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	481	{
	482	return NULL;
	483	}
	484
1da177e4	485	#else
a4023dd0 JP	486	struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	487	const struct flowi fl, struct sock sk,
	488	int flags);
e87b3998 VY	489
	490	/* skb attached with this dst needs transformation if dst->xfrm is valid */
	491	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	492	{
	493	return dst->xfrm;
	494	}
1da177e4	495	#endif
1da177e4 LT	496
1da177e4 LT	497	#endif /* _NET_DST_H */