linux/include/linux/rtnetlink.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_RTNETLINK_H
#define __LINUX_RTNETLINK_H


#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/wait.h>
#include <linux/refcount.h>
#include <uapi/linux/rtnetlink.h>

extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);

static inline int rtnetlink_maybe_send(struct sk_buff *skb, struct net *net,
				       u32 pid, u32 group, int echo)
{
	return !skb ? 0 : rtnetlink_send(skb, net, pid, group, echo);
}

extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
			u32 group, const struct nlmsghdr *nlh, gfp_t flags);
extern void rtnl_set_sk_err(struct net *net, u32 group, int error);
extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
			      u32 id, long expires, u32 error);

void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, gfp_t flags,
		  u32 portid, const struct nlmsghdr *nlh);
void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
			 gfp_t flags, int *new_nsid, int new_ifindex);
struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
				       unsigned change, u32 event,
				       gfp_t flags, int *new_nsid,
				       int new_ifindex, u32 portid,
				       const struct nlmsghdr *nlh);
void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,
		       gfp_t flags, u32 portid, const struct nlmsghdr *nlh);


/* RTNL is used as a global lock for all changes to network configuration  */
extern void rtnl_lock(void);
extern void rtnl_unlock(void);
extern int rtnl_trylock(void);
extern int rtnl_is_locked(void);
extern int rtnl_lock_interruptible(void);
extern int rtnl_lock_killable(void);
extern bool refcount_dec_and_rtnl_lock(refcount_t *r);

extern wait_queue_head_t netdev_unregistering_wq;
extern atomic_t dev_unreg_count;
extern struct rw_semaphore pernet_ops_rwsem;
extern struct rw_semaphore net_rwsem;

#define ASSERT_RTNL() \
	WARN_ONCE(!rtnl_is_locked(), \
		  "RTNL: assertion failed at %s (%d)\n", __FILE__,  __LINE__)

#ifdef CONFIG_PROVE_LOCKING
extern bool lockdep_rtnl_is_held(void);
#else
static inline bool lockdep_rtnl_is_held(void)
{
	return true;
}
#endif /* #ifdef CONFIG_PROVE_LOCKING */

/**
 * rcu_dereference_rtnl - rcu_dereference with debug checking
 * @p: The pointer to read, prior to dereferencing
 *
 * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
 * or RTNL. Note : Please prefer rtnl_dereference() or rcu_dereference()
 */
#define rcu_dereference_rtnl(p)					\
	rcu_dereference_check(p, lockdep_rtnl_is_held())

/**
 * rtnl_dereference - fetch RCU pointer when updates are prevented by RTNL
 * @p: The pointer to read, prior to dereferencing
 *
 * Return: the value of the specified RCU-protected pointer, but omit
 * the READ_ONCE(), because caller holds RTNL.
 */
#define rtnl_dereference(p)					\
	rcu_dereference_protected(p, lockdep_rtnl_is_held())

/**
 * rcu_replace_pointer_rtnl - replace an RCU pointer under rtnl_lock, returning
 * its old value
 * @rp: RCU pointer, whose value is returned
 * @p: regular pointer
 *
 * Perform a replacement under rtnl_lock, where @rp is an RCU-annotated
 * pointer. The old value of @rp is returned, and @rp is set to @p
 */
#define rcu_replace_pointer_rtnl(rp, p)			\
	rcu_replace_pointer(rp, p, lockdep_rtnl_is_held())

#ifdef CONFIG_DEBUG_NET_SMALL_RTNL
void __rtnl_net_lock(struct net *net);
void __rtnl_net_unlock(struct net *net);
void rtnl_net_lock(struct net *net);
void rtnl_net_unlock(struct net *net);
int rtnl_net_trylock(struct net *net);
int rtnl_net_lock_killable(struct net *net);
int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b);

bool rtnl_net_is_locked(struct net *net);

#define ASSERT_RTNL_NET(net)						\
	WARN_ONCE(!rtnl_net_is_locked(net),				\
		  "RTNL_NET: assertion failed at %s (%d)\n",		\
		  __FILE__,  __LINE__)

bool lockdep_rtnl_net_is_held(struct net *net);

#define rcu_dereference_rtnl_net(net, p)				\
	rcu_dereference_check(p, lockdep_rtnl_net_is_held(net))
#define rtnl_net_dereference(net, p)					\
	rcu_dereference_protected(p, lockdep_rtnl_net_is_held(net))
#define rcu_replace_pointer_rtnl_net(net, rp, p)			\
	rcu_replace_pointer(rp, p, lockdep_rtnl_net_is_held(net))
#else
static inline void __rtnl_net_lock(struct net *net) {}
static inline void __rtnl_net_unlock(struct net *net) {}

static inline void rtnl_net_lock(struct net *net)
{
	rtnl_lock();
}

static inline void rtnl_net_unlock(struct net *net)
{
	rtnl_unlock();
}

static inline int rtnl_net_trylock(struct net *net)
{
	return rtnl_trylock();
}

static inline int rtnl_net_lock_killable(struct net *net)
{
	return rtnl_lock_killable();
}

static inline void ASSERT_RTNL_NET(struct net *net)
{
	ASSERT_RTNL();
}

#define rcu_dereference_rtnl_net(net, p)		\
	rcu_dereference_rtnl(p)
#define rtnl_net_dereference(net, p)			\
	rtnl_dereference(p)
#define rcu_replace_pointer_rtnl_net(net, rp, p)	\
	rcu_replace_pointer_rtnl(rp, p)
#endif

static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
{
	return rtnl_dereference(dev->ingress_queue);
}

static inline struct netdev_queue *dev_ingress_queue_rcu(struct net_device *dev)
{
	return rcu_dereference(dev->ingress_queue);
}

struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);

#ifdef CONFIG_NET_INGRESS
void net_inc_ingress_queue(void);
void net_dec_ingress_queue(void);
#endif

#ifdef CONFIG_NET_EGRESS
void net_inc_egress_queue(void);
void net_dec_egress_queue(void);
void netdev_xmit_skip_txqueue(bool skip);
#endif

void rtnetlink_init(void);
void __rtnl_unlock(void);
void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);

/* Shared by rtnl_fdb_dump() and various ndo_fdb_dump() helpers. */
struct ndo_fdb_dump_context {
	unsigned long ifindex;
	unsigned long fdb_idx;
};

extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
			     struct netlink_callback *cb,
			     struct net_device *dev,
			     struct net_device *filter_dev,
			     int *idx);
extern int ndo_dflt_fdb_add(struct ndmsg *ndm,
			    struct nlattr *tb[],
			    struct net_device *dev,
			    const unsigned char *addr,
			    u16 vid,
			    u16 flags);
extern int ndo_dflt_fdb_del(struct ndmsg *ndm,
			    struct nlattr *tb[],
			    struct net_device *dev,
			    const unsigned char *addr,
			    u16 vid);

extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
				   struct net_device *dev, u16 mode,
				   u32 flags, u32 mask, int nlflags,
				   u32 filter_mask,
				   int (*vlan_fill)(struct sk_buff *skb,
						    struct net_device *dev,
						    u32 filter_mask));

extern void rtnl_offload_xstats_notify(struct net_device *dev);

static inline int rtnl_has_listeners(const struct net *net, u32 group)
{
	struct sock *rtnl = net->rtnl;

	return netlink_has_listeners(rtnl, group);
}

/**
 * rtnl_notify_needed - check if notification is needed
 * @net: Pointer to the net namespace
 * @nlflags: netlink ingress message flags
 * @group: rtnl group
 *
 * Based on the ingress message flags and rtnl group, returns true
 * if a notification is needed, false otherwise.
 */
static inline bool
rtnl_notify_needed(const struct net *net, u16 nlflags, u32 group)
{
	return (nlflags & NLM_F_ECHO) || rtnl_has_listeners(net, group);
}

void netif_set_operstate(struct net_device *dev, int newstate);

#endif	/* __LINUX_RTNETLINK_H */