xref: /linux-6.15/include/linux/ipc_namespace.h (revision 2d6ffcca)
1 #ifndef __IPC_NAMESPACE_H__
2 #define __IPC_NAMESPACE_H__
3 
4 #include <linux/err.h>
5 #include <linux/idr.h>
6 #include <linux/rwsem.h>
7 #include <linux/notifier.h>
8 
9 /*
10  * ipc namespace events
11  */
12 #define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
13 #define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
14 #define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
15 
16 #define IPCNS_CALLBACK_PRI 0
17 
18 
19 struct ipc_ids {
20 	int in_use;
21 	unsigned short seq;
22 	unsigned short seq_max;
23 	struct rw_semaphore rw_mutex;
24 	struct idr ipcs_idr;
25 };
26 
27 struct ipc_namespace {
28 	struct kref	kref;
29 	struct ipc_ids	ids[3];
30 
31 	int		sem_ctls[4];
32 	int		used_sems;
33 
34 	int		msg_ctlmax;
35 	int		msg_ctlmnb;
36 	int		msg_ctlmni;
37 	atomic_t	msg_bytes;
38 	atomic_t	msg_hdrs;
39 
40 	size_t		shm_ctlmax;
41 	size_t		shm_ctlall;
42 	int		shm_ctlmni;
43 	int		shm_tot;
44 
45 	struct notifier_block ipcns_nb;
46 };
47 
48 extern struct ipc_namespace init_ipc_ns;
49 extern atomic_t nr_ipc_ns;
50 
51 #ifdef CONFIG_SYSVIPC
52 #define INIT_IPC_NS(ns)		.ns		= &init_ipc_ns,
53 
54 extern int register_ipcns_notifier(struct ipc_namespace *);
55 extern int cond_register_ipcns_notifier(struct ipc_namespace *);
56 extern int unregister_ipcns_notifier(struct ipc_namespace *);
57 extern int ipcns_notify(unsigned long);
58 
59 #else /* CONFIG_SYSVIPC */
60 #define INIT_IPC_NS(ns)
61 #endif /* CONFIG_SYSVIPC */
62 
63 #if defined(CONFIG_SYSVIPC) && defined(CONFIG_IPC_NS)
64 extern void free_ipc_ns(struct kref *kref);
65 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
66 				       struct ipc_namespace *ns);
67 extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
68 		      void (*free)(struct ipc_namespace *,
69 				   struct kern_ipc_perm *));
70 
71 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
72 {
73 	if (ns)
74 		kref_get(&ns->kref);
75 	return ns;
76 }
77 
78 static inline void put_ipc_ns(struct ipc_namespace *ns)
79 {
80 	kref_put(&ns->kref, free_ipc_ns);
81 }
82 #else
83 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
84 		struct ipc_namespace *ns)
85 {
86 	if (flags & CLONE_NEWIPC)
87 		return ERR_PTR(-EINVAL);
88 
89 	return ns;
90 }
91 
92 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
93 {
94 	return ns;
95 }
96 
97 static inline void put_ipc_ns(struct ipc_namespace *ns)
98 {
99 }
100 #endif
101 #endif
102