[mirror_ubuntu-jammy-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>

#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 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	(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
	 * 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.
 */
static inline void 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;
	}
}


/**
 *	__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);
}

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