[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 sock *sk, struct sk_buff *skb);

	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
#define DST_METADATA		0x0200

	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

#ifdef CONFIG_64BIT
	struct lwtunnel_state   *lwtstate;
	/*
	 * Align __refcnt to a 64 bytes alignment
	 * (L1_CACHE_SIZE would be too much)
	 */
	long			__pad_to_align_refcnt[1];
#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;
#ifndef CONFIG_64BIT
	struct lwtunnel_state   *lwtstate;
#endif
	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_FLAGS		0x3UL
#define __DST_METRICS_PTR(Y)	\
	((u32 *)((Y) & ~DST_METRICS_FLAGS))
#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;
}

/* Kernel-internal feature bits that are unallocated in user space. */
#define DST_FEATURE_ECN_CA	(1 << 31)

#define DST_FEATURE_MASK	(DST_FEATURE_ECN_CA)
#define DST_FEATURE_ECN_MASK	(DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)

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, unsigned long refdst)
{
	nskb->_skb_refdst = refdst;
	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
		dst_clone(skb_dst(nskb));
}

static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
{
	__skb_dst_copy(nskb, oskb->_skb_refdst);
}

/**
 * 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);
}

int dst_discard_sk(struct sock *sk, struct sk_buff *skb);
static inline int dst_discard(struct sk_buff *skb)
{
	return dst_discard_sk(skb->sk, skb);
}
void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
		int initial_obsolete, unsigned short flags);
void dst_init(struct dst_entry *dst, 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 sock *sk, struct sk_buff *skb)
{
	return skb_dst(skb)->output(sk, skb);
}
static inline int dst_output_okfn(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	return dst_output(sk, 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_subsys_init(void);

/* Flags for xfrm_lookup flags argument. */
enum {
	XFRM_LOOKUP_ICMP = 1 << 0,
	XFRM_LOOKUP_QUEUE = 1 << 1,
	XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
};

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 dst_entry *xfrm_lookup_route(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);

struct dst_entry *xfrm_lookup_route(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	47	int (input)(struct sk_buff );
aad88724	48	int (output)(struct sock sk, struct sk_buff *skb);
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
f38a9eb1	60	#define DST_METADATA 0x0200
f6b72b62	61
5110effe DM	62	unsigned short pending_confirm;
5110effe DM	63
62fa8a84	64	short error;
f5b0a874 DM	65
	66	/* A non-zero value of dst->obsolete forces by-hand validation
	67	* of the route entry. Positive values are set by the generic
	68	* dst layer to indicate that the entry has been forcefully
	69	* destroyed.
	70	*
	71	* Negative values are used by the implementation layer code to
	72	* force invocation of the dst_ops->check() method.
	73	*/
62fa8a84	74	short obsolete;
f5b0a874 DM	75	#define DST_OBSOLETE_NONE 0
	76	#define DST_OBSOLETE_DEAD 2
	77	#define DST_OBSOLETE_FORCE_CHK -1
ceb33206	78	#define DST_OBSOLETE_KILL -2
62fa8a84 DM	79	unsigned short header_len; /* more space at head required */
62fa8a84 DM	80	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	81	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	82	__u32 tclassid;
5635c10d ED	83	#else
5635c10d ED	84	__u32 __pad2;
f1dd9c37 ZY	85	#endif
f1dd9c37 ZY	86
751a587a JB	87	#ifdef CONFIG_64BIT
751a587a JB	88	struct lwtunnel_state *lwtstate;
5635c10d ED	89	/*
	90	* Align __refcnt to a 64 bytes alignment
	91	* (L1_CACHE_SIZE would be too much)
	92	*/
61adedf3	93	long __pad_to_align_refcnt[1];
5635c10d	94	#endif
f1dd9c37 ZY	95	/*
	96	* __refcnt wants to be on a different cache line from
	97	* input/output/ops or performance tanks badly
	98	*/
1e19e02c ED	99	atomic_t __refcnt; /* client references */
1e19e02c ED	100	int __use;
f1dd9c37	101	unsigned long lastuse;
751a587a JB	102	#ifndef CONFIG_64BIT
	103	struct lwtunnel_state *lwtstate;
	104	#endif
1e19e02c	105	union {
fc766e4c ED	106	struct dst_entry *next;
	107	struct rtable __rcu *rt_next;
	108	struct rt6_info *rt6_next;
	109	struct dn_route __rcu *dn_next;
1e19e02c	110	};
1da177e4 LT	111	};
1da177e4 LT	112
a4023dd0	113	u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
a37e6e34	114	extern const u32 dst_default_metrics[];
62fa8a84	115
e5fd387a	116	#define DST_METRICS_READ_ONLY 0x1UL
e5fd387a	117	#define DST_METRICS_FLAGS 0x3UL
62fa8a84	118	#define __DST_METRICS_PTR(Y) \
e5fd387a	119	((u32 *)((Y) & ~DST_METRICS_FLAGS))
62fa8a84 DM	120	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	121
	122	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	123	{
	124	return dst->_metrics & DST_METRICS_READ_ONLY;
	125	}
	126
a4023dd0	127	void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
62fa8a84 DM	128
	129	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	130	{
	131	unsigned long val = dst->_metrics;
	132	if (!(val & DST_METRICS_READ_ONLY))
	133	__dst_destroy_metrics_generic(dst, val);
	134	}
	135
	136	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	137	{
	138	unsigned long p = dst->_metrics;
	139
1f37070d SH	140	BUG_ON(!p);
1f37070d SH	141
62fa8a84 DM	142	if (p & DST_METRICS_READ_ONLY)
	143	return dst->ops->cow_metrics(dst, p);
	144	return __DST_METRICS_PTR(p);
	145	}
	146
	147	/* This may only be invoked before the entry has reached global
	148	* visibility.
	149	*/
	150	static inline void dst_init_metrics(struct dst_entry *dst,
	151	const u32 *src_metrics,
	152	bool read_only)
	153	{
	154	dst->_metrics = ((unsigned long) src_metrics) \|
	155	(read_only ? DST_METRICS_READ_ONLY : 0);
	156	}
	157
	158	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	159	{
	160	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	161
	162	if (dst_metrics) {
	163	u32 *src_metrics = DST_METRICS_PTR(src);
	164
	165	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	166	}
	167	}
	168
	169	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	170	{
	171	return DST_METRICS_PTR(dst);
	172	}
	173
1da177e4	174	static inline u32
5170ae82	175	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	176	{
62fa8a84 DM	177	u32 *p = DST_METRICS_PTR(dst);
	178
	179	return p[metric-1];
defb3519 DM	180	}
defb3519 DM	181
5170ae82 DM	182	static inline u32
	183	dst_metric(const struct dst_entry *dst, const int metric)
	184	{
0dbaee3b	185	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	186	metric == RTAX_ADVMSS \|\|
d33e4553 DM	187	metric == RTAX_MTU);
5170ae82 DM	188	return dst_metric_raw(dst, metric);
	189	}
	190
0dbaee3b DM	191	static inline u32
	192	dst_metric_advmss(const struct dst_entry *dst)
	193	{
	194	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	195
	196	if (!advmss)
	197	advmss = dst->ops->default_advmss(dst);
	198
	199	return advmss;
	200	}
	201
defb3519 DM	202	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	203	{
62fa8a84	204	u32 *p = dst_metrics_write_ptr(dst);
defb3519	205
62fa8a84 DM	206	if (p)
62fa8a84 DM	207	p[metric-1] = val;
1da177e4 LT	208	}
1da177e4 LT	209
c3a8d947 DB	210	/* Kernel-internal feature bits that are unallocated in user space. */
	211	#define DST_FEATURE_ECN_CA (1 << 31)
	212
	213	#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
	214	#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA \| RTAX_FEATURE_ECN)
	215
0c3adfb8 GBY	216	static inline u32
	217	dst_feature(const struct dst_entry *dst, u32 feature)
	218	{
bb5b7c11	219	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	220	}
0c3adfb8 GBY	221
1da177e4 LT	222	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	223	{
618f9bc7	224	return dst->ops->mtu(dst);
1da177e4 LT	225	}
1da177e4 LT	226
c1e20f7c SH	227	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	228	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	229	{
	230	return msecs_to_jiffies(dst_metric(dst, metric));
	231	}
	232
1da177e4 LT	233	static inline u32
	234	dst_allfrag(const struct dst_entry *dst)
	235	{
0c3adfb8	236	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	237	return ret;
	238	}
	239
	240	static inline int
d33e4553	241	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	242	{
	243	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	244	}
	245
7f95e188	246	static inline void dst_hold(struct dst_entry *dst)
1da177e4	247	{
5635c10d ED	248	/*
	249	* If your kernel compilation stops here, please check
	250	* __pad_to_align_refcnt declaration in struct dst_entry
	251	*/
	252	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	253	atomic_inc(&dst->__refcnt);
	254	}
	255
03f49f34 PE	256	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	257	{
	258	dst_hold(dst);
	259	dst->__use++;
	260	dst->lastuse = time;
	261	}
	262
7fee226a ED	263	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	264	{
	265	dst->__use++;
	266	dst->lastuse = time;
	267	}
	268
7f95e188	269	static inline struct dst_entry dst_clone(struct dst_entry dst)
1da177e4 LT	270	{
	271	if (dst)
	272	atomic_inc(&dst->__refcnt);
	273	return dst;
	274	}
	275
a4023dd0	276	void dst_release(struct dst_entry *dst);
7fee226a ED	277
	278	static inline void refdst_drop(unsigned long refdst)
	279	{
	280	if (!(refdst & SKB_DST_NOREF))
	281	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	282	}
	283
	284	/**
	285	* skb_dst_drop - drops skb dst
	286	* @skb: buffer
	287	*
	288	* Drops dst reference count if a reference was taken.
	289	*/
adf30907 ED	290	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	291	{
7fee226a ED	292	if (skb->_skb_refdst) {
	293	refdst_drop(skb->_skb_refdst);
	294	skb->_skb_refdst = 0UL;
	295	}
	296	}
	297
e79e2595	298	static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
7fee226a	299	{
e79e2595	300	nskb->_skb_refdst = refdst;
7fee226a ED	301	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	302	dst_clone(skb_dst(nskb));
	303	}
	304
e79e2595 JS	305	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	306	{
	307	__skb_dst_copy(nskb, oskb->_skb_refdst);
	308	}
	309
7fee226a ED	310	/**
	311	* skb_dst_force - makes sure skb dst is refcounted
	312	* @skb: buffer
	313	*
	314	* If dst is not yet refcounted, let's do it
	315	*/
	316	static inline void skb_dst_force(struct sk_buff *skb)
	317	{
	318	if (skb_dst_is_noref(skb)) {
	319	WARN_ON(!rcu_read_lock_held());
	320	skb->_skb_refdst &= ~SKB_DST_NOREF;
	321	dst_clone(skb_dst(skb));
	322	}
adf30907	323	}
1da177e4	324
d19d56dd	325
290b895e ED	326	/**
	327	* __skb_tunnel_rx - prepare skb for rx reinsert
	328	* @skb: buffer
	329	* @dev: tunnel device
ea23192e	330	* @net: netns for packet i/o
290b895e ED	331	*
	332	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	333	* so make some cleanups. (no accounting done)
	334	*/
ea23192e ND	335	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	336	struct net *net)
290b895e ED	337	{
290b895e ED	338	skb->dev = dev;
bdeab991 TH	339
bdeab991 TH	340	/*
7539fadc	341	* Clear hash so that we can recalulate the hash for the
bdeab991 TH	342	* encapsulated packet, unless we have already determine the hash
	343	* over the L4 4-tuple.
	344	*/
7539fadc	345	skb_clear_hash_if_not_l4(skb);
290b895e	346	skb_set_queue_mapping(skb, 0);
ea23192e	347	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
290b895e ED	348	}
290b895e ED	349
d19d56dd ED	350	/**
	351	* skb_tunnel_rx - prepare skb for rx reinsert
	352	* @skb: buffer
	353	* @dev: tunnel device
	354	*
	355	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	356	* so make some cleanups, and perform accounting.
290b895e	357	* Note: this accounting is not SMP safe.
d19d56dd	358	*/
ea23192e ND	359	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	360	struct net *net)
d19d56dd	361	{
d19d56dd ED	362	/* TODO : stats should be SMP safe */
	363	dev->stats.rx_packets++;
	364	dev->stats.rx_bytes += skb->len;
ea23192e	365	__skb_tunnel_rx(skb, dev, net);
d19d56dd ED	366	}
d19d56dd ED	367
aad88724 ED	368	int dst_discard_sk(struct sock sk, struct sk_buff skb);
	369	static inline int dst_discard(struct sk_buff *skb)
	370	{
	371	return dst_discard_sk(skb->sk, skb);
	372	}
a4023dd0 JP	373	void dst_alloc(struct dst_ops ops, struct net_device *dev, int initial_ref,
a4023dd0 JP	374	int initial_obsolete, unsigned short flags);
f38a9eb1 TG	375	void dst_init(struct dst_entry dst, struct dst_ops ops,
	376	struct net_device *dev, int initial_ref, int initial_obsolete,
	377	unsigned short flags);
a4023dd0 JP	378	void __dst_free(struct dst_entry *dst);
a4023dd0 JP	379	struct dst_entry dst_destroy(struct dst_entry dst);
1da177e4	380
7f95e188	381	static inline void dst_free(struct dst_entry *dst)
1da177e4	382	{
f5b0a874	383	if (dst->obsolete > 0)
1da177e4 LT	384	return;
	385	if (!atomic_read(&dst->__refcnt)) {
	386	dst = dst_destroy(dst);
	387	if (!dst)
	388	return;
	389	}
	390	__dst_free(dst);
	391	}
	392
	393	static inline void dst_rcu_free(struct rcu_head *head)
	394	{
	395	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	396	dst_free(dst);
	397	}
	398
	399	static inline void dst_confirm(struct dst_entry *dst)
	400	{
5110effe DM	401	dst->pending_confirm = 1;
5110effe DM	402	}
f2c31e32	403
5110effe DM	404	static inline int dst_neigh_output(struct dst_entry dst, struct neighbour n,
	405	struct sk_buff *skb)
	406	{
425f09ab ED	407	const struct hh_cache *hh;
	408
	409	if (dst->pending_confirm) {
	410	unsigned long now = jiffies;
5110effe	411
5110effe	412	dst->pending_confirm = 0;
425f09ab ED	413	/* avoid dirtying neighbour */
	414	if (n->confirmed != now)
	415	n->confirmed = now;
69cce1d1	416	}
5110effe DM	417
	418	hh = &n->hh;
	419	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
	420	return neigh_hh_output(hh, skb);
	421	else
	422	return n->output(n, skb);
1da177e4 LT	423	}
1da177e4 LT	424
d3aaeb38 DM	425	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
d3aaeb38 DM	426	{
aaa0c23c ZZ	427	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
aaa0c23c ZZ	428	return IS_ERR(n) ? NULL : n;
f894cbf8 DM	429	}
	430
	431	static inline struct neighbour dst_neigh_lookup_skb(const struct dst_entry dst,
	432	struct sk_buff *skb)
	433	{
aaa0c23c ZZ	434	struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
aaa0c23c ZZ	435	return IS_ERR(n) ? NULL : n;
d3aaeb38 DM	436	}
d3aaeb38 DM	437
1da177e4 LT	438	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	439	{
adf30907	440	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	441	if (dst && dst->ops && dst->ops->link_failure)
	442	dst->ops->link_failure(skb);
	443	}
	444
	445	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	446	{
	447	unsigned long expires = jiffies + timeout;
	448
	449	if (expires == 0)
	450	expires = 1;
	451
	452	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	453	dst->expires = expires;
	454	}
	455
	456	/* Output packet to network from transport. */
5a70649e	457	static inline int dst_output(struct sock sk, struct sk_buff skb)
aad88724 ED	458	{
	459	return skb_dst(skb)->output(sk, skb);
	460	}
0c4b51f0 EB	461	static inline int dst_output_okfn(struct net net, struct sock sk, struct sk_buff *skb)
	462	{
	463	return dst_output(sk, skb);
	464	}
1da177e4 LT	465
	466	/* Input packet from network to transport. */
	467	static inline int dst_input(struct sk_buff *skb)
	468	{
adf30907	469	return skb_dst(skb)->input(skb);
1da177e4 LT	470	}
	471
	472	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	473	{
	474	if (dst->obsolete)
	475	dst = dst->ops->check(dst, cookie);
	476	return dst;
	477	}
	478
f38a9eb1	479	void dst_subsys_init(void);
1da177e4	480
815f4e57 HX	481	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	482	enum {
80c0bc9e	483	XFRM_LOOKUP_ICMP = 1 << 0,
b8c203b2	484	XFRM_LOOKUP_QUEUE = 1 << 1,
ac37e251	485	XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
815f4e57 HX	486	};
815f4e57 HX	487
1da177e4 LT	488	struct flowi;
1da177e4 LT	489	#ifndef CONFIG_XFRM
452edd59 DM	490	static inline struct dst_entry xfrm_lookup(struct net net,
	491	struct dst_entry *dst_orig,
	492	const struct flowi fl, struct sock sk,
	493	int flags)
1da177e4	494	{
452edd59	495	return dst_orig;
f92ee619 SK	496	}
	497
	498	static inline struct dst_entry xfrm_lookup_route(struct net net,
	499	struct dst_entry *dst_orig,
	500	const struct flowi *fl,
	501	struct sock *sk,
	502	int flags)
	503	{
	504	return dst_orig;
	505	}
e87b3998 VY	506
	507	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	508	{
	509	return NULL;
	510	}
	511
1da177e4	512	#else
a4023dd0 JP	513	struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	514	const struct flowi fl, struct sock sk,
	515	int flags);
e87b3998	516
f92ee619 SK	517	struct dst_entry xfrm_lookup_route(struct net net, struct dst_entry *dst_orig,
	518	const struct flowi fl, struct sock sk,
	519	int flags);
	520
e87b3998 VY	521	/* skb attached with this dst needs transformation if dst->xfrm is valid */
	522	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	523	{
	524	return dst->xfrm;
	525	}
1da177e4	526	#endif
1da177e4 LT	527
1da177e4 LT	528	#endif /* _NET_DST_H */