[mirror_ubuntu-eoan-kernel.git] / include / net / dst.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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 <linux/refcount.h>
#include <net/neighbour.h>
#include <asm/processor.h>

struct sk_buff;

struct dst_entry {
	struct net_device       *dev;
	struct  dst_ops	        *ops;
	unsigned long		_metrics;
	unsigned long           expires;
#ifdef CONFIG_XFRM
	struct xfrm_state	*xfrm;
#else
	void			*__pad1;
#endif
	int			(*input)(struct sk_buff *);
	int			(*output)(struct net *net, struct sock *sk, struct sk_buff *skb);

	unsigned short		flags;
#define DST_HOST		0x0001
#define DST_NOXFRM		0x0002
#define DST_NOPOLICY		0x0004
#define DST_NOCOUNT		0x0008
#define DST_FAKE_RTABLE		0x0010
#define DST_XFRM_TUNNEL		0x0020
#define DST_XFRM_QUEUE		0x0040
#define DST_METADATA		0x0080

	/* 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 */

	/*
	 * __refcnt wants to be on a different cache line from
	 * input/output/ops or performance tanks badly
	 */
#ifdef CONFIG_64BIT
	atomic_t		__refcnt;	/* 64-bit offset 64 */
#endif
	int			__use;
	unsigned long		lastuse;
	struct lwtunnel_state   *lwtstate;
	struct rcu_head		rcu_head;
	short			error;
	short			__pad;
	__u32			tclassid;
#ifndef CONFIG_64BIT
	atomic_t		__refcnt;	/* 32-bit offset 64 */
#endif
};

struct dst_metrics {
	u32		metrics[RTAX_MAX];
	refcount_t	refcnt;
};
extern const struct dst_metrics dst_default_metrics;

u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);

#define DST_METRICS_READ_ONLY		0x1UL
#define DST_METRICS_REFCOUNTED		0x2UL
#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	(1U << 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
	 * the placement of __refcnt in struct dst_entry
	 */
	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
	WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0);
}

static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
{
	if (unlikely(time != dst->lastuse)) {
		dst->__use++;
		dst->lastuse = time;
	}
}

static inline void dst_hold_and_use(struct dst_entry *dst, unsigned long time)
{
	dst_hold(dst);
	dst_use_noref(dst, time);
}

static inline struct dst_entry *dst_clone(struct dst_entry *dst)
{
	if (dst)
		dst_hold(dst);
	return dst;
}

void dst_release(struct dst_entry *dst);

void dst_release_immediate(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);
}

/**
 * dst_hold_safe - Take a reference on a dst if possible
 * @dst: pointer to dst entry
 *
 * This helper returns false if it could not safely
 * take a reference on a dst.
 */
static inline bool dst_hold_safe(struct dst_entry *dst)
{
	return atomic_inc_not_zero(&dst->__refcnt);
}

/**
 * skb_dst_force - makes sure skb dst is refcounted
 * @skb: buffer
 *
 * If dst is not yet refcounted and not destroyed, grab a ref on it.
 * Returns true if dst is refcounted.
 */
static inline bool skb_dst_force(struct sk_buff *skb)
{
	if (skb_dst_is_noref(skb)) {
		struct dst_entry *dst = skb_dst(skb);

		WARN_ON(!rcu_read_lock_held());
		if (!dst_hold_safe(dst))
			dst = NULL;

		skb->_skb_refdst = (unsigned long)dst;
	}

	return skb->_skb_refdst != 0UL;
}


/**
 *	__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
 *	@net: netns for packet i/o
 *
 *	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);
}

static inline u32 dst_tclassid(const struct sk_buff *skb)
{
#ifdef CONFIG_IP_ROUTE_CLASSID
	const struct dst_entry *dst;

	dst = skb_dst(skb);
	if (dst)
		return dst->tclassid;
#endif
	return 0;
}

int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
static inline int dst_discard(struct sk_buff *skb)
{
	return dst_discard_out(&init_net, 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);
struct dst_entry *dst_destroy(struct dst_entry *dst);
void dst_dev_put(struct dst_entry *dst);

static inline void dst_confirm(struct dst_entry *dst)
{
}

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_confirm_neigh(const struct dst_entry *dst,
				     const void *daddr)
{
	if (dst->ops->confirm_neigh)
		dst->ops->confirm_neigh(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 net *net, struct sock *sk, struct sk_buff *skb)
{
	return skb_dst(skb)->output(net, 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;
}

/* 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,
					    const struct sock *sk,
					    int flags)
{
	return dst_orig;
}

static inline struct dst_entry *
xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
		      const struct flowi *fl, const struct sock *sk,
		      int flags, u32 if_id)
{
	return dst_orig;
}

static inline struct dst_entry *xfrm_lookup_route(struct net *net,
						  struct dst_entry *dst_orig,
						  const struct flowi *fl,
						  const 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, const struct sock *sk,
			      int flags);

struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
					struct dst_entry *dst_orig,
					const struct flowi *fl,
					const struct sock *sk, int flags,
					u32 if_id);

struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
				    const struct flowi *fl, const 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

static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
{
	struct dst_entry *dst = skb_dst(skb);

	if (dst && dst->ops->update_pmtu)
		dst->ops->update_pmtu(dst, NULL, skb, mtu);
}

static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
					 struct dst_entry *encap_dst,
					 int headroom)
{
	u32 encap_mtu = dst_mtu(encap_dst);

	if (skb->len > encap_mtu - headroom)
		skb_dst_update_pmtu(skb, encap_mtu - headroom);
}

#endif /* _NET_DST_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	/*
	3	* net/dst.h Protocol independent destination cache definitions.
	4	*
	5	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	6	*
	7	*/
	8
	9	#ifndef _NET_DST_H
	10	#define _NET_DST_H
	11
86393e52	12	#include <net/dst_ops.h>
14c85021	13	#include <linux/netdevice.h>
1da177e4 LT	14	#include <linux/rtnetlink.h>
1da177e4 LT	15	#include <linux/rcupdate.h>
187f1882	16	#include <linux/bug.h>
1da177e4	17	#include <linux/jiffies.h>
9620fef2	18	#include <linux/refcount.h>
1da177e4 LT	19	#include <net/neighbour.h>
	20	#include <asm/processor.h>
	21
1da177e4 LT	22	struct sk_buff;
1da177e4 LT	23
fd2c3ef7	24	struct dst_entry {
66727145	25	struct net_device *dev;
62fa8a84 DM	26	struct dst_ops *ops;
62fa8a84 DM	27	unsigned long _metrics;
ecd98837	28	unsigned long expires;
def8b4fa	29	#ifdef CONFIG_XFRM
1da177e4	30	struct xfrm_state *xfrm;
5635c10d ED	31	#else
5635c10d ED	32	void *__pad1;
def8b4fa	33	#endif
7f95e188	34	int (input)(struct sk_buff );
ede2059d	35	int (output)(struct net net, struct sock sk, struct sk_buff skb);
1da177e4	36
5110effe	37	unsigned short flags;
f6b72b62 DM	38	#define DST_HOST 0x0001
	39	#define DST_NOXFRM 0x0002
	40	#define DST_NOPOLICY 0x0004
1eb04e7c WW	41	#define DST_NOCOUNT 0x0008
	42	#define DST_FAKE_RTABLE 0x0010
	43	#define DST_XFRM_TUNNEL 0x0020
	44	#define DST_XFRM_QUEUE 0x0040
	45	#define DST_METADATA 0x0080
f6b72b62	46
f5b0a874 DM	47	/* A non-zero value of dst->obsolete forces by-hand validation
	48	* of the route entry. Positive values are set by the generic
	49	* dst layer to indicate that the entry has been forcefully
	50	* destroyed.
	51	*
	52	* Negative values are used by the implementation layer code to
	53	* force invocation of the dst_ops->check() method.
	54	*/
62fa8a84	55	short obsolete;
f5b0a874 DM	56	#define DST_OBSOLETE_NONE 0
	57	#define DST_OBSOLETE_DEAD 2
	58	#define DST_OBSOLETE_FORCE_CHK -1
ceb33206	59	#define DST_OBSOLETE_KILL -2
62fa8a84 DM	60	unsigned short header_len; /* more space at head required */
62fa8a84 DM	61	unsigned short trailer_len; /* space to reserve at tail */
51ce8bd4	62
f1dd9c37 ZY	63	/*
	64	* __refcnt wants to be on a different cache line from
	65	* input/output/ops or performance tanks badly
	66	*/
8b207e73 DM	67	#ifdef CONFIG_64BIT
	68	atomic_t __refcnt; /* 64-bit offset 64 */
	69	#endif
1e19e02c	70	int __use;
f1dd9c37	71	unsigned long lastuse;
751a587a	72	struct lwtunnel_state *lwtstate;
8b207e73 DM	73	struct rcu_head rcu_head;
	74	short error;
	75	short __pad;
	76	__u32 tclassid;
	77	#ifndef CONFIG_64BIT
	78	atomic_t __refcnt; /* 32-bit offset 64 */
	79	#endif
1da177e4 LT	80	};
1da177e4 LT	81
3fb07daf ED	82	struct dst_metrics {
3fb07daf ED	83	u32 metrics[RTAX_MAX];
9620fef2	84	refcount_t refcnt;
3fb07daf ED	85	};
	86	extern const struct dst_metrics dst_default_metrics;
	87
a4023dd0	88	u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
62fa8a84	89
e5fd387a	90	#define DST_METRICS_READ_ONLY 0x1UL
3fb07daf	91	#define DST_METRICS_REFCOUNTED 0x2UL
e5fd387a	92	#define DST_METRICS_FLAGS 0x3UL
62fa8a84	93	#define __DST_METRICS_PTR(Y) \
e5fd387a	94	((u32 *)((Y) & ~DST_METRICS_FLAGS))
62fa8a84 DM	95	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	96
	97	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	98	{
	99	return dst->_metrics & DST_METRICS_READ_ONLY;
	100	}
	101
a4023dd0	102	void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
62fa8a84 DM	103
	104	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	105	{
	106	unsigned long val = dst->_metrics;
	107	if (!(val & DST_METRICS_READ_ONLY))
	108	__dst_destroy_metrics_generic(dst, val);
	109	}
	110
	111	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	112	{
	113	unsigned long p = dst->_metrics;
	114
1f37070d SH	115	BUG_ON(!p);
1f37070d SH	116
62fa8a84 DM	117	if (p & DST_METRICS_READ_ONLY)
	118	return dst->ops->cow_metrics(dst, p);
	119	return __DST_METRICS_PTR(p);
	120	}
	121
	122	/* This may only be invoked before the entry has reached global
	123	* visibility.
	124	*/
	125	static inline void dst_init_metrics(struct dst_entry *dst,
	126	const u32 *src_metrics,
	127	bool read_only)
	128	{
	129	dst->_metrics = ((unsigned long) src_metrics) \|
	130	(read_only ? DST_METRICS_READ_ONLY : 0);
	131	}
	132
	133	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	134	{
	135	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	136
	137	if (dst_metrics) {
	138	u32 *src_metrics = DST_METRICS_PTR(src);
	139
	140	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	141	}
	142	}
	143
	144	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	145	{
	146	return DST_METRICS_PTR(dst);
	147	}
	148
1da177e4	149	static inline u32
5170ae82	150	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	151	{
62fa8a84 DM	152	u32 *p = DST_METRICS_PTR(dst);
	153
	154	return p[metric-1];
defb3519 DM	155	}
defb3519 DM	156
5170ae82 DM	157	static inline u32
	158	dst_metric(const struct dst_entry *dst, const int metric)
	159	{
0dbaee3b	160	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	161	metric == RTAX_ADVMSS \|\|
d33e4553 DM	162	metric == RTAX_MTU);
5170ae82 DM	163	return dst_metric_raw(dst, metric);
	164	}
	165
0dbaee3b DM	166	static inline u32
	167	dst_metric_advmss(const struct dst_entry *dst)
	168	{
	169	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	170
	171	if (!advmss)
	172	advmss = dst->ops->default_advmss(dst);
	173
	174	return advmss;
	175	}
	176
defb3519 DM	177	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	178	{
62fa8a84	179	u32 *p = dst_metrics_write_ptr(dst);
defb3519	180
62fa8a84 DM	181	if (p)
62fa8a84 DM	182	p[metric-1] = val;
1da177e4 LT	183	}
1da177e4 LT	184
c3a8d947	185	/* Kernel-internal feature bits that are unallocated in user space. */
40f6a2cb	186	#define DST_FEATURE_ECN_CA (1U << 31)
c3a8d947 DB	187
	188	#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
	189	#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA \| RTAX_FEATURE_ECN)
	190
0c3adfb8 GBY	191	static inline u32
	192	dst_feature(const struct dst_entry *dst, u32 feature)
	193	{
bb5b7c11	194	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	195	}
0c3adfb8 GBY	196
1da177e4 LT	197	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	198	{
618f9bc7	199	return dst->ops->mtu(dst);
1da177e4 LT	200	}
1da177e4 LT	201
c1e20f7c SH	202	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	203	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	204	{
	205	return msecs_to_jiffies(dst_metric(dst, metric));
	206	}
	207
1da177e4 LT	208	static inline u32
	209	dst_allfrag(const struct dst_entry *dst)
	210	{
0c3adfb8	211	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	212	return ret;
	213	}
	214
	215	static inline int
d33e4553	216	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	217	{
	218	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	219	}
	220
7f95e188	221	static inline void dst_hold(struct dst_entry *dst)
1da177e4	222	{
5635c10d ED	223	/*
5635c10d ED	224	* If your kernel compilation stops here, please check
8b207e73	225	* the placement of __refcnt in struct dst_entry
5635c10d ED	226	*/
5635c10d ED	227	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
44ebe791	228	WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0);
1da177e4 LT	229	}
1da177e4 LT	230
0da4af00	231	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
03f49f34	232	{
32d18ab1	233	if (unlikely(time != dst->lastuse)) {
0da4af00 WW	234	dst->__use++;
	235	dst->lastuse = time;
	236	}
03f49f34 PE	237	}
03f49f34 PE	238
0da4af00	239	static inline void dst_hold_and_use(struct dst_entry *dst, unsigned long time)
7fee226a	240	{
0da4af00 WW	241	dst_hold(dst);
0da4af00 WW	242	dst_use_noref(dst, time);
7fee226a ED	243	}
7fee226a ED	244
7f95e188	245	static inline struct dst_entry dst_clone(struct dst_entry dst)
1da177e4 LT	246	{
1da177e4 LT	247	if (dst)
222d7dbd	248	dst_hold(dst);
1da177e4 LT	249	return dst;
	250	}
	251
a4023dd0	252	void dst_release(struct dst_entry *dst);
7fee226a	253
5f56f409 WW	254	void dst_release_immediate(struct dst_entry *dst);
5f56f409 WW	255
7fee226a ED	256	static inline void refdst_drop(unsigned long refdst)
	257	{
	258	if (!(refdst & SKB_DST_NOREF))
	259	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	260	}
	261
	262	/**
	263	* skb_dst_drop - drops skb dst
	264	* @skb: buffer
	265	*
	266	* Drops dst reference count if a reference was taken.
	267	*/
adf30907 ED	268	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	269	{
7fee226a ED	270	if (skb->_skb_refdst) {
	271	refdst_drop(skb->_skb_refdst);
	272	skb->_skb_refdst = 0UL;
	273	}
	274	}
	275
e79e2595	276	static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
7fee226a	277	{
e79e2595	278	nskb->_skb_refdst = refdst;
7fee226a ED	279	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	280	dst_clone(skb_dst(nskb));
	281	}
	282
e79e2595 JS	283	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	284	{
	285	__skb_dst_copy(nskb, oskb->_skb_refdst);
	286	}
	287
5037e9ef ED	288	/**
	289	* dst_hold_safe - Take a reference on a dst if possible
	290	* @dst: pointer to dst entry
	291	*
	292	* This helper returns false if it could not safely
	293	* take a reference on a dst.
	294	*/
	295	static inline bool dst_hold_safe(struct dst_entry *dst)
	296	{
b2a9c0ed	297	return atomic_inc_not_zero(&dst->__refcnt);
5037e9ef ED	298	}
	299
	300	/**
222d7dbd	301	* skb_dst_force - makes sure skb dst is refcounted
5037e9ef ED	302	* @skb: buffer
	303	*
	304	* If dst is not yet refcounted and not destroyed, grab a ref on it.
b60a7738	305	* Returns true if dst is refcounted.
5037e9ef	306	*/
b60a7738	307	static inline bool skb_dst_force(struct sk_buff *skb)
5037e9ef ED	308	{
	309	if (skb_dst_is_noref(skb)) {
	310	struct dst_entry *dst = skb_dst(skb);
	311
222d7dbd	312	WARN_ON(!rcu_read_lock_held());
5037e9ef ED	313	if (!dst_hold_safe(dst))
	314	dst = NULL;
	315
	316	skb->_skb_refdst = (unsigned long)dst;
	317	}
b60a7738 FW	318
b60a7738 FW	319	return skb->_skb_refdst != 0UL;
5037e9ef ED	320	}
5037e9ef ED	321
d19d56dd	322
290b895e ED	323	/**
	324	* __skb_tunnel_rx - prepare skb for rx reinsert
	325	* @skb: buffer
	326	* @dev: tunnel device
ea23192e	327	* @net: netns for packet i/o
290b895e ED	328	*
	329	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	330	* so make some cleanups. (no accounting done)
	331	*/
ea23192e ND	332	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	333	struct net *net)
290b895e ED	334	{
290b895e ED	335	skb->dev = dev;
bdeab991 TH	336
bdeab991 TH	337	/*
7539fadc	338	* Clear hash so that we can recalulate the hash for the
bdeab991 TH	339	* encapsulated packet, unless we have already determine the hash
	340	* over the L4 4-tuple.
	341	*/
7539fadc	342	skb_clear_hash_if_not_l4(skb);
290b895e	343	skb_set_queue_mapping(skb, 0);
ea23192e	344	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
290b895e ED	345	}
290b895e ED	346
d19d56dd ED	347	/**
	348	* skb_tunnel_rx - prepare skb for rx reinsert
	349	* @skb: buffer
	350	* @dev: tunnel device
8eb1a859	351	* @net: netns for packet i/o
d19d56dd ED	352	*
	353	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	354	* so make some cleanups, and perform accounting.
290b895e	355	* Note: this accounting is not SMP safe.
d19d56dd	356	*/
ea23192e ND	357	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	358	struct net *net)
d19d56dd	359	{
d19d56dd ED	360	/* TODO : stats should be SMP safe */
	361	dev->stats.rx_packets++;
	362	dev->stats.rx_bytes += skb->len;
ea23192e	363	__skb_tunnel_rx(skb, dev, net);
d19d56dd ED	364	}
d19d56dd ED	365
808c1b69 DB	366	static inline u32 dst_tclassid(const struct sk_buff *skb)
	367	{
	368	#ifdef CONFIG_IP_ROUTE_CLASSID
	369	const struct dst_entry *dst;
	370
	371	dst = skb_dst(skb);
	372	if (dst)
	373	return dst->tclassid;
	374	#endif
	375	return 0;
	376	}
	377
ede2059d	378	int dst_discard_out(struct net net, struct sock sk, struct sk_buff *skb);
aad88724 ED	379	static inline int dst_discard(struct sk_buff *skb)
aad88724 ED	380	{
ede2059d	381	return dst_discard_out(&init_net, skb->sk, skb);
aad88724	382	}
a4023dd0 JP	383	void dst_alloc(struct dst_ops ops, struct net_device *dev, int initial_ref,
a4023dd0 JP	384	int initial_obsolete, unsigned short flags);
f38a9eb1 TG	385	void dst_init(struct dst_entry dst, struct dst_ops ops,
	386	struct net_device *dev, int initial_ref, int initial_obsolete,
	387	unsigned short flags);
a4023dd0	388	struct dst_entry dst_destroy(struct dst_entry dst);
4a6ce2b6	389	void dst_dev_put(struct dst_entry *dst);
1da177e4	390
1da177e4 LT	391	static inline void dst_confirm(struct dst_entry *dst)
1da177e4 LT	392	{
5110effe	393	}
f2c31e32	394
d3aaeb38 DM	395	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
d3aaeb38 DM	396	{
aaa0c23c ZZ	397	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
aaa0c23c ZZ	398	return IS_ERR(n) ? NULL : n;
f894cbf8 DM	399	}
	400
	401	static inline struct neighbour dst_neigh_lookup_skb(const struct dst_entry dst,
	402	struct sk_buff *skb)
	403	{
aaa0c23c ZZ	404	struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
aaa0c23c ZZ	405	return IS_ERR(n) ? NULL : n;
d3aaeb38 DM	406	}
d3aaeb38 DM	407
63fca65d JA	408	static inline void dst_confirm_neigh(const struct dst_entry *dst,
	409	const void *daddr)
	410	{
	411	if (dst->ops->confirm_neigh)
	412	dst->ops->confirm_neigh(dst, daddr);
	413	}
	414
1da177e4 LT	415	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	416	{
adf30907	417	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	418	if (dst && dst->ops && dst->ops->link_failure)
	419	dst->ops->link_failure(skb);
	420	}
	421
	422	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	423	{
	424	unsigned long expires = jiffies + timeout;
	425
	426	if (expires == 0)
	427	expires = 1;
	428
	429	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	430	dst->expires = expires;
	431	}
	432
	433	/* Output packet to network from transport. */
13206b6b	434	static inline int dst_output(struct net net, struct sock sk, struct sk_buff *skb)
aad88724	435	{
ede2059d	436	return skb_dst(skb)->output(net, sk, skb);
aad88724	437	}
1da177e4 LT	438
	439	/* Input packet from network to transport. */
	440	static inline int dst_input(struct sk_buff *skb)
	441	{
adf30907	442	return skb_dst(skb)->input(skb);
1da177e4 LT	443	}
	444
	445	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	446	{
	447	if (dst->obsolete)
	448	dst = dst->ops->check(dst, cookie);
	449	return dst;
	450	}
	451
815f4e57 HX	452	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	453	enum {
80c0bc9e	454	XFRM_LOOKUP_ICMP = 1 << 0,
b8c203b2	455	XFRM_LOOKUP_QUEUE = 1 << 1,
ac37e251	456	XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
815f4e57 HX	457	};
815f4e57 HX	458
1da177e4 LT	459	struct flowi;
1da177e4 LT	460	#ifndef CONFIG_XFRM
452edd59 DM	461	static inline struct dst_entry xfrm_lookup(struct net net,
452edd59 DM	462	struct dst_entry *dst_orig,
6f9c9615 ED	463	const struct flowi *fl,
6f9c9615 ED	464	const struct sock *sk,
452edd59	465	int flags)
1da177e4	466	{
452edd59	467	return dst_orig;
f92ee619 SK	468	}
f92ee619 SK	469
bc56b334 BW	470	static inline struct dst_entry *
	471	xfrm_lookup_with_ifid(struct net net, struct dst_entry dst_orig,
	472	const struct flowi fl, const struct sock sk,
	473	int flags, u32 if_id)
	474	{
	475	return dst_orig;
	476	}
	477
f92ee619 SK	478	static inline struct dst_entry xfrm_lookup_route(struct net net,
	479	struct dst_entry *dst_orig,
	480	const struct flowi *fl,
6f9c9615	481	const struct sock *sk,
f92ee619 SK	482	int flags)
	483	{
	484	return dst_orig;
	485	}
e87b3998 VY	486
	487	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	488	{
	489	return NULL;
	490	}
	491
1da177e4	492	#else
a4023dd0	493	struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
6f9c9615	494	const struct flowi fl, const struct sock sk,
a4023dd0	495	int flags);
e87b3998	496
bc56b334 BW	497	struct dst_entry xfrm_lookup_with_ifid(struct net net,
	498	struct dst_entry *dst_orig,
	499	const struct flowi *fl,
	500	const struct sock *sk, int flags,
	501	u32 if_id);
	502
f92ee619	503	struct dst_entry xfrm_lookup_route(struct net net, struct dst_entry *dst_orig,
6f9c9615	504	const struct flowi fl, const struct sock sk,
f92ee619 SK	505	int flags);
f92ee619 SK	506
e87b3998 VY	507	/* skb attached with this dst needs transformation if dst->xfrm is valid */
	508	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	509	{
	510	return dst->xfrm;
	511	}
1da177e4	512	#endif
1da177e4	513
f15ca723 ND	514	static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
	515	{
	516	struct dst_entry *dst = skb_dst(skb);
	517
	518	if (dst && dst->ops->update_pmtu)
	519	dst->ops->update_pmtu(dst, NULL, skb, mtu);
	520	}
	521
6b4f92af SB	522	static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
	523	struct dst_entry *encap_dst,
	524	int headroom)
	525	{
	526	u32 encap_mtu = dst_mtu(encap_dst);
	527
	528	if (skb->len > encap_mtu - headroom)
	529	skb_dst_update_pmtu(skb, encap_mtu - headroom);
	530	}
	531
1da177e4	532	#endif /* _NET_DST_H */