xref: /linux-6.15/include/linux/ipc.h (revision ba6e8564)
1 #ifndef _LINUX_IPC_H
2 #define _LINUX_IPC_H
3 
4 #include <linux/types.h>
5 
6 #define IPC_PRIVATE ((__kernel_key_t) 0)
7 
8 /* Obsolete, used only for backwards compatibility and libc5 compiles */
9 struct ipc_perm
10 {
11 	__kernel_key_t	key;
12 	__kernel_uid_t	uid;
13 	__kernel_gid_t	gid;
14 	__kernel_uid_t	cuid;
15 	__kernel_gid_t	cgid;
16 	__kernel_mode_t	mode;
17 	unsigned short	seq;
18 };
19 
20 /* Include the definition of ipc64_perm */
21 #include <asm/ipcbuf.h>
22 
23 /* resource get request flags */
24 #define IPC_CREAT  00001000   /* create if key is nonexistent */
25 #define IPC_EXCL   00002000   /* fail if key exists */
26 #define IPC_NOWAIT 00004000   /* return error on wait */
27 
28 /* these fields are used by the DIPC package so the kernel as standard
29    should avoid using them if possible */
30 
31 #define IPC_DIPC 00010000  /* make it distributed */
32 #define IPC_OWN  00020000  /* this machine is the DIPC owner */
33 
34 /*
35  * Control commands used with semctl, msgctl and shmctl
36  * see also specific commands in sem.h, msg.h and shm.h
37  */
38 #define IPC_RMID 0     /* remove resource */
39 #define IPC_SET  1     /* set ipc_perm options */
40 #define IPC_STAT 2     /* get ipc_perm options */
41 #define IPC_INFO 3     /* see ipcs */
42 
43 /*
44  * Version flags for semctl, msgctl, and shmctl commands
45  * These are passed as bitflags or-ed with the actual command
46  */
47 #define IPC_OLD 0	/* Old version (no 32-bit UID support on many
48 			   architectures) */
49 #define IPC_64  0x0100  /* New version (support 32-bit UIDs, bigger
50 			   message sizes, etc. */
51 
52 #ifdef __KERNEL__
53 
54 #include <linux/kref.h>
55 
56 #define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
57 
58 /* used by in-kernel data structures */
59 struct kern_ipc_perm
60 {
61 	spinlock_t	lock;
62 	int		deleted;
63 	key_t		key;
64 	uid_t		uid;
65 	gid_t		gid;
66 	uid_t		cuid;
67 	gid_t		cgid;
68 	mode_t		mode;
69 	unsigned long	seq;
70 	void		*security;
71 };
72 
73 struct ipc_ids;
74 struct ipc_namespace {
75 	struct kref	kref;
76 	struct ipc_ids	*ids[3];
77 
78 	int		sem_ctls[4];
79 	int		used_sems;
80 
81 	int		msg_ctlmax;
82 	int		msg_ctlmnb;
83 	int		msg_ctlmni;
84 
85 	size_t		shm_ctlmax;
86 	size_t		shm_ctlall;
87 	int		shm_ctlmni;
88 	int		shm_tot;
89 };
90 
91 extern struct ipc_namespace init_ipc_ns;
92 
93 #ifdef CONFIG_SYSVIPC
94 #define INIT_IPC_NS(ns)		.ns		= &init_ipc_ns,
95 extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
96 #else
97 #define INIT_IPC_NS(ns)
98 static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk)
99 { return 0; }
100 #endif
101 
102 #ifdef CONFIG_IPC_NS
103 extern void free_ipc_ns(struct kref *kref);
104 extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
105 #endif
106 
107 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
108 {
109 #ifdef CONFIG_IPC_NS
110 	if (ns)
111 		kref_get(&ns->kref);
112 #endif
113 	return ns;
114 }
115 
116 static inline void put_ipc_ns(struct ipc_namespace *ns)
117 {
118 #ifdef CONFIG_IPC_NS
119 	kref_put(&ns->kref, free_ipc_ns);
120 #endif
121 }
122 
123 #endif /* __KERNEL__ */
124 
125 #endif /* _LINUX_IPC_H */
126 
127 
128