1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_GENERIC_NETLINK_H
3 #define __LINUX_GENERIC_NETLINK_H
4 
5 #include <uapi/linux/genetlink.h>
6 
7 
8 /* All generic netlink requests are serialized by a global lock.  */
9 extern void genl_lock(void);
10 extern void genl_unlock(void);
11 #ifdef CONFIG_LOCKDEP
12 extern bool lockdep_genl_is_held(void);
13 #endif
14 
15 /* for synchronisation between af_netlink and genetlink */
16 extern atomic_t genl_sk_destructing_cnt;
17 extern wait_queue_head_t genl_sk_destructing_waitq;
18 
19 /**
20  * rcu_dereference_genl - rcu_dereference with debug checking
21  * @p: The pointer to read, prior to dereferencing
22  *
23  * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
24  * or genl mutex. Note : Please prefer genl_dereference() or rcu_dereference()
25  */
26 #define rcu_dereference_genl(p)					\
27 	rcu_dereference_check(p, lockdep_genl_is_held())
28 
29 /**
30  * genl_dereference - fetch RCU pointer when updates are prevented by genl mutex
31  * @p: The pointer to read, prior to dereferencing
32  *
33  * Return the value of the specified RCU-protected pointer, but omit
34  * the READ_ONCE(), because caller holds genl mutex.
35  */
36 #define genl_dereference(p)					\
37 	rcu_dereference_protected(p, lockdep_genl_is_held())
38 
39 #define MODULE_ALIAS_GENL_FAMILY(family)\
40  MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
41 
42 #endif	/* __LINUX_GENERIC_NETLINK_H */
43