[linux-block.git] / include / net / ip6_fib.h

/*
 *	Linux INET6 implementation 
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>	
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#ifndef _IP6_FIB_H
#define _IP6_FIB_H

#include <linux/ipv6_route.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/ip_fib.h>
#include <net/netlink.h>
#include <net/inetpeer.h>
#include <net/fib_notifier.h>

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
#define FIB6_TABLE_HASHSZ 256
#else
#define FIB6_TABLE_HASHSZ 1
#endif

#define RT6_DEBUG 2

#if RT6_DEBUG >= 3
#define RT6_TRACE(x...) pr_debug(x)
#else
#define RT6_TRACE(x...) do { ; } while (0)
#endif

struct rt6_info;
struct fib6_info;

struct fib6_config {
	u32		fc_table;
	u32		fc_metric;
	int		fc_dst_len;
	int		fc_src_len;
	int		fc_ifindex;
	u32		fc_flags;
	u32		fc_protocol;
	u16		fc_type;        /* only 8 bits are used */
	u16		fc_delete_all_nh : 1,
			fc_ignore_dev_down:1,
			__unused : 14;

	struct in6_addr	fc_dst;
	struct in6_addr	fc_src;
	struct in6_addr	fc_prefsrc;
	struct in6_addr	fc_gateway;

	unsigned long	fc_expires;
	struct nlattr	*fc_mx;
	int		fc_mx_len;
	int		fc_mp_len;
	struct nlattr	*fc_mp;

	struct nl_info	fc_nlinfo;
	struct nlattr	*fc_encap;
	u16		fc_encap_type;
};

struct fib6_node {
	struct fib6_node __rcu	*parent;
	struct fib6_node __rcu	*left;
	struct fib6_node __rcu	*right;
#ifdef CONFIG_IPV6_SUBTREES
	struct fib6_node __rcu	*subtree;
#endif
	struct fib6_info __rcu	*leaf;

	__u16			fn_bit;		/* bit key */
	__u16			fn_flags;
	int			fn_sernum;
	struct fib6_info __rcu	*rr_ptr;
	struct rcu_head		rcu;
};

struct fib6_gc_args {
	int			timeout;
	int			more;
};

#ifndef CONFIG_IPV6_SUBTREES
#define FIB6_SUBTREE(fn)	NULL
#else
#define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
#endif

/*
 *	routing information
 *
 */

struct rt6key {
	struct in6_addr	addr;
	int		plen;
};

struct fib6_table;

struct rt6_exception_bucket {
	struct hlist_head	chain;
	int			depth;
};

struct rt6_exception {
	struct hlist_node	hlist;
	struct rt6_info		*rt6i;
	unsigned long		stamp;
	struct rcu_head		rcu;
};

#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
#define FIB6_MAX_DEPTH 5

struct fib6_nh {
	struct fib_nh_common	nh_common;

#ifdef CONFIG_IPV6_ROUTER_PREF
	unsigned long		last_probe;
#endif
};

struct fib6_info {
	struct fib6_table		*fib6_table;
	struct fib6_info __rcu		*fib6_next;
	struct fib6_node __rcu		*fib6_node;

	/* Multipath routes:
	 * siblings is a list of fib6_info that have the the same metric/weight,
	 * destination, but not the same gateway. nsiblings is just a cache
	 * to speed up lookup.
	 */
	struct list_head		fib6_siblings;
	unsigned int			fib6_nsiblings;

	refcount_t			fib6_ref;
	unsigned long			expires;
	struct dst_metrics		*fib6_metrics;
#define fib6_pmtu		fib6_metrics->metrics[RTAX_MTU-1]

	struct rt6key			fib6_dst;
	u32				fib6_flags;
	struct rt6key			fib6_src;
	struct rt6key			fib6_prefsrc;

	struct rt6_info * __percpu	*rt6i_pcpu;
	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;

	u32				fib6_metric;
	u8				fib6_protocol;
	u8				fib6_type;
	u8				exception_bucket_flushed:1,
					should_flush:1,
					dst_nocount:1,
					dst_nopolicy:1,
					dst_host:1,
					fib6_destroying:1,
					unused:2;

	struct fib6_nh			fib6_nh;
	struct rcu_head			rcu;
};

struct rt6_info {
	struct dst_entry		dst;
	struct fib6_info __rcu		*from;

	struct rt6key			rt6i_dst;
	struct rt6key			rt6i_src;
	struct in6_addr			rt6i_gateway;
	struct inet6_dev		*rt6i_idev;
	u32				rt6i_flags;

	struct list_head		rt6i_uncached;
	struct uncached_list		*rt6i_uncached_list;

	/* more non-fragment space at head required */
	unsigned short			rt6i_nfheader_len;
};

struct fib6_result {
	struct fib6_nh		*nh;
	struct fib6_info	*f6i;
	u32			fib6_flags;
	u8			fib6_type;
	struct rt6_info		*rt6;
};

#define for_each_fib6_node_rt_rcu(fn)					\
	for (rt = rcu_dereference((fn)->leaf); rt;			\
	     rt = rcu_dereference(rt->fib6_next))

#define for_each_fib6_walker_rt(w)					\
	for (rt = (w)->leaf; rt;					\
	     rt = rcu_dereference_protected(rt->fib6_next, 1))

static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
{
	return ((struct rt6_info *)dst)->rt6i_idev;
}

static inline void fib6_clean_expires(struct fib6_info *f6i)
{
	f6i->fib6_flags &= ~RTF_EXPIRES;
	f6i->expires = 0;
}

static inline void fib6_set_expires(struct fib6_info *f6i,
				    unsigned long expires)
{
	f6i->expires = expires;
	f6i->fib6_flags |= RTF_EXPIRES;
}

static inline bool fib6_check_expired(const struct fib6_info *f6i)
{
	if (f6i->fib6_flags & RTF_EXPIRES)
		return time_after(jiffies, f6i->expires);
	return false;
}

/* Function to safely get fn->sernum for passed in rt
 * and store result in passed in cookie.
 * Return true if we can get cookie safely
 * Return false if not
 */
static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
					u32 *cookie)
{
	struct fib6_node *fn;
	bool status = false;

	fn = rcu_dereference(f6i->fib6_node);

	if (fn) {
		*cookie = fn->fn_sernum;
		/* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
		smp_rmb();
		status = true;
	}

	return status;
}

static inline u32 rt6_get_cookie(const struct rt6_info *rt)
{
	struct fib6_info *from;
	u32 cookie = 0;

	rcu_read_lock();

	from = rcu_dereference(rt->from);
	if (from && (rt->rt6i_flags & RTF_PCPU ||
	    unlikely(!list_empty(&rt->rt6i_uncached))))
		fib6_get_cookie_safe(from, &cookie);

	rcu_read_unlock();

	return cookie;
}

static inline void ip6_rt_put(struct rt6_info *rt)
{
	/* dst_release() accepts a NULL parameter.
	 * We rely on dst being first structure in struct rt6_info
	 */
	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
	dst_release(&rt->dst);
}

struct fib6_info *fib6_info_alloc(gfp_t gfp_flags);
void fib6_info_destroy_rcu(struct rcu_head *head);

static inline void fib6_info_hold(struct fib6_info *f6i)
{
	refcount_inc(&f6i->fib6_ref);
}

static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
{
	return refcount_inc_not_zero(&f6i->fib6_ref);
}

static inline void fib6_info_release(struct fib6_info *f6i)
{
	if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
		call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
}

enum fib6_walk_state {
#ifdef CONFIG_IPV6_SUBTREES
	FWS_S,
#endif
	FWS_L,
	FWS_R,
	FWS_C,
	FWS_U
};

struct fib6_walker {
	struct list_head lh;
	struct fib6_node *root, *node;
	struct fib6_info *leaf;
	enum fib6_walk_state state;
	unsigned int skip;
	unsigned int count;
	int (*func)(struct fib6_walker *);
	void *args;
};

struct rt6_statistics {
	__u32		fib_nodes;		/* all fib6 nodes */
	__u32		fib_route_nodes;	/* intermediate nodes */
	__u32		fib_rt_entries;		/* rt entries in fib table */
	__u32		fib_rt_cache;		/* cached rt entries in exception table */
	__u32		fib_discarded_routes;	/* total number of routes delete */

	/* The following stats are not protected by any lock */
	atomic_t	fib_rt_alloc;		/* total number of routes alloced */
	atomic_t	fib_rt_uncache;		/* rt entries in uncached list */
};

#define RTN_TL_ROOT	0x0001
#define RTN_ROOT	0x0002		/* tree root node		*/
#define RTN_RTINFO	0x0004		/* node with valid routing info	*/

/*
 *	priority levels (or metrics)
 *
 */


struct fib6_table {
	struct hlist_node	tb6_hlist;
	u32			tb6_id;
	spinlock_t		tb6_lock;
	struct fib6_node	tb6_root;
	struct inet_peer_base	tb6_peers;
	unsigned int		flags;
	unsigned int		fib_seq;
#define RT6_TABLE_HAS_DFLT_ROUTER	BIT(0)
};

#define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
#define RT6_TABLE_MAIN		RT_TABLE_MAIN
#define RT6_TABLE_DFLT		RT6_TABLE_MAIN
#define RT6_TABLE_INFO		RT6_TABLE_MAIN
#define RT6_TABLE_PREFIX	RT6_TABLE_MAIN

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
#define FIB6_TABLE_MIN		1
#define FIB6_TABLE_MAX		RT_TABLE_MAX
#define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
#else
#define FIB6_TABLE_MIN		RT_TABLE_MAIN
#define FIB6_TABLE_MAX		FIB6_TABLE_MIN
#define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
#endif

typedef struct rt6_info *(*pol_lookup_t)(struct net *,
					 struct fib6_table *,
					 struct flowi6 *,
					 const struct sk_buff *, int);

struct fib6_entry_notifier_info {
	struct fib_notifier_info info; /* must be first */
	struct fib6_info *rt;
};

/*
 *	exported functions
 */

struct fib6_table *fib6_get_table(struct net *net, u32 id);
struct fib6_table *fib6_new_table(struct net *net, u32 id);
struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
				   const struct sk_buff *skb,
				   int flags, pol_lookup_t lookup);

/* called with rcu lock held; can return error pointer
 * caller needs to select path
 */
int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
		struct fib6_result *res, int flags);

/* called with rcu lock held; caller needs to select path */
int fib6_table_lookup(struct net *net, struct fib6_table *table,
		      int oif, struct flowi6 *fl6, struct fib6_result *res,
		      int strict);

void fib6_select_path(const struct net *net, struct fib6_result *res,
		      struct flowi6 *fl6, int oif, bool have_oif_match,
		      const struct sk_buff *skb, int strict);
struct fib6_node *fib6_node_lookup(struct fib6_node *root,
				   const struct in6_addr *daddr,
				   const struct in6_addr *saddr);

struct fib6_node *fib6_locate(struct fib6_node *root,
			      const struct in6_addr *daddr, int dst_len,
			      const struct in6_addr *saddr, int src_len,
			      bool exact_match);

void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
		    void *arg);
void fib6_clean_all_skip_notify(struct net *net,
				int (*func)(struct fib6_info *, void *arg),
				void *arg);

int fib6_add(struct fib6_node *root, struct fib6_info *rt,
	     struct nl_info *info, struct netlink_ext_ack *extack);
int fib6_del(struct fib6_info *rt, struct nl_info *info);

static inline
void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
{
	const struct fib6_info *from;

	rcu_read_lock();

	from = rcu_dereference(rt->from);
	if (from) {
		*addr = from->fib6_prefsrc.addr;
	} else {
		struct in6_addr in6_zero = {};

		*addr = in6_zero;
	}

	rcu_read_unlock();
}

static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i)
{
	return f6i->fib6_nh.fib_nh_dev;
}

int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
		 struct fib6_config *cfg, gfp_t gfp_flags,
		 struct netlink_ext_ack *extack);
void fib6_nh_release(struct fib6_nh *fib6_nh);

void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
		     unsigned int flags);

void fib6_run_gc(unsigned long expires, struct net *net, bool force);

void fib6_gc_cleanup(void);

int fib6_init(void);

struct ipv6_route_iter {
	struct seq_net_private p;
	struct fib6_walker w;
	loff_t skip;
	struct fib6_table *tbl;
	int sernum;
};

extern const struct seq_operations ipv6_route_seq_ops;

int call_fib6_notifier(struct notifier_block *nb, struct net *net,
		       enum fib_event_type event_type,
		       struct fib_notifier_info *info);
int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
			struct fib_notifier_info *info);

int __net_init fib6_notifier_init(struct net *net);
void __net_exit fib6_notifier_exit(struct net *net);

unsigned int fib6_tables_seq_read(struct net *net);
int fib6_tables_dump(struct net *net, struct notifier_block *nb);

void fib6_update_sernum(struct net *net, struct fib6_info *rt);
void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);

void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
{
	return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
}

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
int fib6_rules_init(void);
void fib6_rules_cleanup(void);
bool fib6_rule_default(const struct fib_rule *rule);
int fib6_rules_dump(struct net *net, struct notifier_block *nb);
unsigned int fib6_rules_seq_read(struct net *net);

static inline bool fib6_rules_early_flow_dissect(struct net *net,
						 struct sk_buff *skb,
						 struct flowi6 *fl6,
						 struct flow_keys *flkeys)
{
	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;

	if (!net->ipv6.fib6_rules_require_fldissect)
		return false;

	skb_flow_dissect_flow_keys(skb, flkeys, flag);
	fl6->fl6_sport = flkeys->ports.src;
	fl6->fl6_dport = flkeys->ports.dst;
	fl6->flowi6_proto = flkeys->basic.ip_proto;

	return true;
}
#else
static inline int               fib6_rules_init(void)
{
	return 0;
}
static inline void              fib6_rules_cleanup(void)
{
	return ;
}
static inline bool fib6_rule_default(const struct fib_rule *rule)
{
	return true;
}
static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
{
	return 0;
}
static inline unsigned int fib6_rules_seq_read(struct net *net)
{
	return 0;
}
static inline bool fib6_rules_early_flow_dissect(struct net *net,
						 struct sk_buff *skb,
						 struct flowi6 *fl6,
						 struct flow_keys *flkeys)
{
	return false;
}
#endif
#endif
Commit	Line	Data
	1	/*
	2	* Linux INET6 implementation
	3	*
	4	* Authors:
	5	* Pedro Roque <roque@di.fc.ul.pt>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
	13	#ifndef _IP6_FIB_H
	14	#define _IP6_FIB_H
	15
	16	#include <linux/ipv6_route.h>
	17	#include <linux/rtnetlink.h>
	18	#include <linux/spinlock.h>
	19	#include <linux/notifier.h>
	20	#include <net/dst.h>
	21	#include <net/flow.h>
	22	#include <net/ip_fib.h>
	23	#include <net/netlink.h>
	24	#include <net/inetpeer.h>
	25	#include <net/fib_notifier.h>
	26
	27	#ifdef CONFIG_IPV6_MULTIPLE_TABLES
	28	#define FIB6_TABLE_HASHSZ 256
	29	#else
	30	#define FIB6_TABLE_HASHSZ 1
	31	#endif
	32
	33	#define RT6_DEBUG 2
	34
	35	#if RT6_DEBUG >= 3
	36	#define RT6_TRACE(x...) pr_debug(x)
	37	#else
	38	#define RT6_TRACE(x...) do { ; } while (0)
	39	#endif
	40
	41	struct rt6_info;
	42	struct fib6_info;
	43
	44	struct fib6_config {
	45	u32 fc_table;
	46	u32 fc_metric;
	47	int fc_dst_len;
	48	int fc_src_len;
	49	int fc_ifindex;
	50	u32 fc_flags;
	51	u32 fc_protocol;
	52	u16 fc_type; /* only 8 bits are used */
	53	u16 fc_delete_all_nh : 1,
	54	fc_ignore_dev_down:1,
	55	__unused : 14;
	56
	57	struct in6_addr fc_dst;
	58	struct in6_addr fc_src;
	59	struct in6_addr fc_prefsrc;
	60	struct in6_addr fc_gateway;
	61
	62	unsigned long fc_expires;
	63	struct nlattr *fc_mx;
	64	int fc_mx_len;
	65	int fc_mp_len;
	66	struct nlattr *fc_mp;
	67
	68	struct nl_info fc_nlinfo;
	69	struct nlattr *fc_encap;
	70	u16 fc_encap_type;
	71	};
	72
	73	struct fib6_node {
	74	struct fib6_node __rcu *parent;
	75	struct fib6_node __rcu *left;
	76	struct fib6_node __rcu *right;
	77	#ifdef CONFIG_IPV6_SUBTREES
	78	struct fib6_node __rcu *subtree;
	79	#endif
	80	struct fib6_info __rcu *leaf;
	81
	82	__u16 fn_bit; /* bit key */
	83	__u16 fn_flags;
	84	int fn_sernum;
	85	struct fib6_info __rcu *rr_ptr;
	86	struct rcu_head rcu;
	87	};
	88
	89	struct fib6_gc_args {
	90	int timeout;
	91	int more;
	92	};
	93
	94	#ifndef CONFIG_IPV6_SUBTREES
	95	#define FIB6_SUBTREE(fn) NULL
	96	#else
	97	#define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
	98	#endif
	99
	100	/*
	101	* routing information
	102	*
	103	*/
	104
	105	struct rt6key {
	106	struct in6_addr addr;
	107	int plen;
	108	};
	109
	110	struct fib6_table;
	111
	112	struct rt6_exception_bucket {
	113	struct hlist_head chain;
	114	int depth;
	115	};
	116
	117	struct rt6_exception {
	118	struct hlist_node hlist;
	119	struct rt6_info *rt6i;
	120	unsigned long stamp;
	121	struct rcu_head rcu;
	122	};
	123
	124	#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
	125	#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
	126	#define FIB6_MAX_DEPTH 5
	127
	128	struct fib6_nh {
	129	struct fib_nh_common nh_common;
	130
	131	#ifdef CONFIG_IPV6_ROUTER_PREF
	132	unsigned long last_probe;
	133	#endif
	134	};
	135
	136	struct fib6_info {
	137	struct fib6_table *fib6_table;
	138	struct fib6_info __rcu *fib6_next;
	139	struct fib6_node __rcu *fib6_node;
	140
	141	/* Multipath routes:
	142	* siblings is a list of fib6_info that have the the same metric/weight,
	143	* destination, but not the same gateway. nsiblings is just a cache
	144	* to speed up lookup.
	145	*/
	146	struct list_head fib6_siblings;
	147	unsigned int fib6_nsiblings;
	148
	149	refcount_t fib6_ref;
	150	unsigned long expires;
	151	struct dst_metrics *fib6_metrics;
	152	#define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
	153
	154	struct rt6key fib6_dst;
	155	u32 fib6_flags;
	156	struct rt6key fib6_src;
	157	struct rt6key fib6_prefsrc;
	158
	159	struct rt6_info * __percpu *rt6i_pcpu;
	160	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
	161
	162	u32 fib6_metric;
	163	u8 fib6_protocol;
	164	u8 fib6_type;
	165	u8 exception_bucket_flushed:1,
	166	should_flush:1,
	167	dst_nocount:1,
	168	dst_nopolicy:1,
	169	dst_host:1,
	170	fib6_destroying:1,
	171	unused:2;
	172
	173	struct fib6_nh fib6_nh;
	174	struct rcu_head rcu;
	175	};
	176
	177	struct rt6_info {
	178	struct dst_entry dst;
	179	struct fib6_info __rcu *from;
	180
	181	struct rt6key rt6i_dst;
	182	struct rt6key rt6i_src;
	183	struct in6_addr rt6i_gateway;
	184	struct inet6_dev *rt6i_idev;
	185	u32 rt6i_flags;
	186
	187	struct list_head rt6i_uncached;
	188	struct uncached_list *rt6i_uncached_list;
	189
	190	/* more non-fragment space at head required */
	191	unsigned short rt6i_nfheader_len;
	192	};
	193
	194	struct fib6_result {
	195	struct fib6_nh *nh;
	196	struct fib6_info *f6i;
	197	u32 fib6_flags;
	198	u8 fib6_type;
	199	struct rt6_info *rt6;
	200	};
	201
	202	#define for_each_fib6_node_rt_rcu(fn) \
	203	for (rt = rcu_dereference((fn)->leaf); rt; \
	204	rt = rcu_dereference(rt->fib6_next))
	205
	206	#define for_each_fib6_walker_rt(w) \
	207	for (rt = (w)->leaf; rt; \
	208	rt = rcu_dereference_protected(rt->fib6_next, 1))
	209
	210	static inline struct inet6_dev ip6_dst_idev(struct dst_entry dst)
	211	{
	212	return ((struct rt6_info *)dst)->rt6i_idev;
	213	}
	214
	215	static inline void fib6_clean_expires(struct fib6_info *f6i)
	216	{
	217	f6i->fib6_flags &= ~RTF_EXPIRES;
	218	f6i->expires = 0;
	219	}
	220
	221	static inline void fib6_set_expires(struct fib6_info *f6i,
	222	unsigned long expires)
	223	{
	224	f6i->expires = expires;
	225	f6i->fib6_flags \|= RTF_EXPIRES;
	226	}
	227
	228	static inline bool fib6_check_expired(const struct fib6_info *f6i)
	229	{
	230	if (f6i->fib6_flags & RTF_EXPIRES)
	231	return time_after(jiffies, f6i->expires);
	232	return false;
	233	}
	234
	235	/* Function to safely get fn->sernum for passed in rt
	236	* and store result in passed in cookie.
	237	* Return true if we can get cookie safely
	238	* Return false if not
	239	*/
	240	static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
	241	u32 *cookie)
	242	{
	243	struct fib6_node *fn;
	244	bool status = false;
	245
	246	fn = rcu_dereference(f6i->fib6_node);
	247
	248	if (fn) {
	249	*cookie = fn->fn_sernum;
	250	/* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
	251	smp_rmb();
	252	status = true;
	253	}
	254
	255	return status;
	256	}
	257
	258	static inline u32 rt6_get_cookie(const struct rt6_info *rt)
	259	{
	260	struct fib6_info *from;
	261	u32 cookie = 0;
	262
	263	rcu_read_lock();
	264
	265	from = rcu_dereference(rt->from);
	266	if (from && (rt->rt6i_flags & RTF_PCPU \|\|
	267	unlikely(!list_empty(&rt->rt6i_uncached))))
	268	fib6_get_cookie_safe(from, &cookie);
	269
	270	rcu_read_unlock();
	271
	272	return cookie;
	273	}
	274
	275	static inline void ip6_rt_put(struct rt6_info *rt)
	276	{
	277	/* dst_release() accepts a NULL parameter.
	278	* We rely on dst being first structure in struct rt6_info
	279	*/
	280	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
	281	dst_release(&rt->dst);
	282	}
	283
	284	struct fib6_info *fib6_info_alloc(gfp_t gfp_flags);
	285	void fib6_info_destroy_rcu(struct rcu_head *head);
	286
	287	static inline void fib6_info_hold(struct fib6_info *f6i)
	288	{
	289	refcount_inc(&f6i->fib6_ref);
	290	}
	291
	292	static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
	293	{
	294	return refcount_inc_not_zero(&f6i->fib6_ref);
	295	}
	296
	297	static inline void fib6_info_release(struct fib6_info *f6i)
	298	{
	299	if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
	300	call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
	301	}
	302
	303	enum fib6_walk_state {
	304	#ifdef CONFIG_IPV6_SUBTREES
	305	FWS_S,
	306	#endif
	307	FWS_L,
	308	FWS_R,
	309	FWS_C,
	310	FWS_U
	311	};
	312
	313	struct fib6_walker {
	314	struct list_head lh;
	315	struct fib6_node root, node;
	316	struct fib6_info *leaf;
	317	enum fib6_walk_state state;
	318	unsigned int skip;
	319	unsigned int count;
	320	int (func)(struct fib6_walker );
	321	void *args;
	322	};
	323
	324	struct rt6_statistics {
	325	__u32 fib_nodes; /* all fib6 nodes */
	326	__u32 fib_route_nodes; /* intermediate nodes */
	327	__u32 fib_rt_entries; /* rt entries in fib table */
	328	__u32 fib_rt_cache; /* cached rt entries in exception table */
	329	__u32 fib_discarded_routes; /* total number of routes delete */
	330
	331	/* The following stats are not protected by any lock */
	332	atomic_t fib_rt_alloc; /* total number of routes alloced */
	333	atomic_t fib_rt_uncache; /* rt entries in uncached list */
	334	};
	335
	336	#define RTN_TL_ROOT 0x0001
	337	#define RTN_ROOT 0x0002 /* tree root node */
	338	#define RTN_RTINFO 0x0004 /* node with valid routing info */
	339
	340	/*
	341	* priority levels (or metrics)
	342	*
	343	*/
	344
	345
	346	struct fib6_table {
	347	struct hlist_node tb6_hlist;
	348	u32 tb6_id;
	349	spinlock_t tb6_lock;
	350	struct fib6_node tb6_root;
	351	struct inet_peer_base tb6_peers;
	352	unsigned int flags;
	353	unsigned int fib_seq;
	354	#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
	355	};
	356
	357	#define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
	358	#define RT6_TABLE_MAIN RT_TABLE_MAIN
	359	#define RT6_TABLE_DFLT RT6_TABLE_MAIN
	360	#define RT6_TABLE_INFO RT6_TABLE_MAIN
	361	#define RT6_TABLE_PREFIX RT6_TABLE_MAIN
	362
	363	#ifdef CONFIG_IPV6_MULTIPLE_TABLES
	364	#define FIB6_TABLE_MIN 1
	365	#define FIB6_TABLE_MAX RT_TABLE_MAX
	366	#define RT6_TABLE_LOCAL RT_TABLE_LOCAL
	367	#else
	368	#define FIB6_TABLE_MIN RT_TABLE_MAIN
	369	#define FIB6_TABLE_MAX FIB6_TABLE_MIN
	370	#define RT6_TABLE_LOCAL RT6_TABLE_MAIN
	371	#endif
	372
	373	typedef struct rt6_info (pol_lookup_t)(struct net *,
	374	struct fib6_table *,
	375	struct flowi6 *,
	376	const struct sk_buff *, int);
	377
	378	struct fib6_entry_notifier_info {
	379	struct fib_notifier_info info; /* must be first */
	380	struct fib6_info *rt;
	381	};
	382
	383	/*
	384	* exported functions
	385	*/
	386
	387	struct fib6_table fib6_get_table(struct net net, u32 id);
	388	struct fib6_table fib6_new_table(struct net net, u32 id);
	389	struct dst_entry fib6_rule_lookup(struct net net, struct flowi6 *fl6,
	390	const struct sk_buff *skb,
	391	int flags, pol_lookup_t lookup);
	392
	393	/* called with rcu lock held; can return error pointer
	394	* caller needs to select path
	395	*/
	396	int fib6_lookup(struct net net, int oif, struct flowi6 fl6,
	397	struct fib6_result *res, int flags);
	398
	399	/* called with rcu lock held; caller needs to select path */
	400	int fib6_table_lookup(struct net net, struct fib6_table table,
	401	int oif, struct flowi6 fl6, struct fib6_result res,
	402	int strict);
	403
	404	void fib6_select_path(const struct net net, struct fib6_result res,
	405	struct flowi6 *fl6, int oif, bool have_oif_match,
	406	const struct sk_buff *skb, int strict);
	407	struct fib6_node fib6_node_lookup(struct fib6_node root,
	408	const struct in6_addr *daddr,
	409	const struct in6_addr *saddr);
	410
	411	struct fib6_node fib6_locate(struct fib6_node root,
	412	const struct in6_addr *daddr, int dst_len,
	413	const struct in6_addr *saddr, int src_len,
	414	bool exact_match);
	415
	416	void fib6_clean_all(struct net net, int (func)(struct fib6_info , void arg),
	417	void *arg);
	418	void fib6_clean_all_skip_notify(struct net *net,
	419	int (func)(struct fib6_info , void *arg),
	420	void *arg);
	421
	422	int fib6_add(struct fib6_node root, struct fib6_info rt,
	423	struct nl_info info, struct netlink_ext_ack extack);
	424	int fib6_del(struct fib6_info rt, struct nl_info info);
	425
	426	static inline
	427	void rt6_get_prefsrc(const struct rt6_info rt, struct in6_addr addr)
	428	{
	429	const struct fib6_info *from;
	430
	431	rcu_read_lock();
	432
	433	from = rcu_dereference(rt->from);
	434	if (from) {
	435	*addr = from->fib6_prefsrc.addr;
	436	} else {
	437	struct in6_addr in6_zero = {};
	438
	439	*addr = in6_zero;
	440	}
	441
	442	rcu_read_unlock();
	443	}
	444
	445	static inline struct net_device fib6_info_nh_dev(const struct fib6_info f6i)
	446	{
	447	return f6i->fib6_nh.fib_nh_dev;
	448	}
	449
	450	int fib6_nh_init(struct net net, struct fib6_nh fib6_nh,
	451	struct fib6_config *cfg, gfp_t gfp_flags,
	452	struct netlink_ext_ack *extack);
	453	void fib6_nh_release(struct fib6_nh *fib6_nh);
	454
	455	void inet6_rt_notify(int event, struct fib6_info rt, struct nl_info info,
	456	unsigned int flags);
	457
	458	void fib6_run_gc(unsigned long expires, struct net *net, bool force);
	459
	460	void fib6_gc_cleanup(void);
	461
	462	int fib6_init(void);
	463
	464	struct ipv6_route_iter {
	465	struct seq_net_private p;
	466	struct fib6_walker w;
	467	loff_t skip;
	468	struct fib6_table *tbl;
	469	int sernum;
	470	};
	471
	472	extern const struct seq_operations ipv6_route_seq_ops;
	473
	474	int call_fib6_notifier(struct notifier_block nb, struct net net,
	475	enum fib_event_type event_type,
	476	struct fib_notifier_info *info);
	477	int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
	478	struct fib_notifier_info *info);
	479
	480	int __net_init fib6_notifier_init(struct net *net);
	481	void __net_exit fib6_notifier_exit(struct net *net);
	482
	483	unsigned int fib6_tables_seq_read(struct net *net);
	484	int fib6_tables_dump(struct net net, struct notifier_block nb);
	485
	486	void fib6_update_sernum(struct net net, struct fib6_info rt);
	487	void fib6_update_sernum_upto_root(struct net net, struct fib6_info rt);
	488
	489	void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
	490	static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
	491	{
	492	return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
	493	}
	494
	495	#ifdef CONFIG_IPV6_MULTIPLE_TABLES
	496	int fib6_rules_init(void);
	497	void fib6_rules_cleanup(void);
	498	bool fib6_rule_default(const struct fib_rule *rule);
	499	int fib6_rules_dump(struct net net, struct notifier_block nb);
	500	unsigned int fib6_rules_seq_read(struct net *net);
	501
	502	static inline bool fib6_rules_early_flow_dissect(struct net *net,
	503	struct sk_buff *skb,
	504	struct flowi6 *fl6,
	505	struct flow_keys *flkeys)
	506	{
	507	unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
	508
	509	if (!net->ipv6.fib6_rules_require_fldissect)
	510	return false;
	511
	512	skb_flow_dissect_flow_keys(skb, flkeys, flag);
	513	fl6->fl6_sport = flkeys->ports.src;
	514	fl6->fl6_dport = flkeys->ports.dst;
	515	fl6->flowi6_proto = flkeys->basic.ip_proto;
	516
	517	return true;
	518	}
	519	#else
	520	static inline int fib6_rules_init(void)
	521	{
	522	return 0;
	523	}
	524	static inline void fib6_rules_cleanup(void)
	525	{
	526	return ;
	527	}
	528	static inline bool fib6_rule_default(const struct fib_rule *rule)
	529	{
	530	return true;
	531	}
	532	static inline int fib6_rules_dump(struct net net, struct notifier_block nb)
	533	{
	534	return 0;
	535	}
	536	static inline unsigned int fib6_rules_seq_read(struct net *net)
	537	{
	538	return 0;
	539	}
	540	static inline bool fib6_rules_early_flow_dissect(struct net *net,
	541	struct sk_buff *skb,
	542	struct flowi6 *fl6,
	543	struct flow_keys *flkeys)
	544	{
	545	return false;
	546	}
	547	#endif
	548	#endif