xref: /linux-6.15/include/linux/ipc.h (revision 40efcb05)
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 /*
53  * These are used to wrap system calls.
54  *
55  * See architecture code for ugly details..
56  */
57 struct ipc_kludge {
58 	struct msgbuf __user *msgp;
59 	long msgtyp;
60 };
61 
62 #define SEMOP		 1
63 #define SEMGET		 2
64 #define SEMCTL		 3
65 #define SEMTIMEDOP	 4
66 #define MSGSND		11
67 #define MSGRCV		12
68 #define MSGGET		13
69 #define MSGCTL		14
70 #define SHMAT		21
71 #define SHMDT		22
72 #define SHMGET		23
73 #define SHMCTL		24
74 
75 /* Used by the DIPC package, try and avoid reusing it */
76 #define DIPC            25
77 
78 #define IPCCALL(version,op)	((version)<<16 | (op))
79 
80 #ifdef __KERNEL__
81 
82 #include <linux/kref.h>
83 #include <linux/spinlock.h>
84 
85 #define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
86 
87 /* used by in-kernel data structures */
88 struct kern_ipc_perm
89 {
90 	spinlock_t	lock;
91 	int		deleted;
92 	int		id;
93 	key_t		key;
94 	uid_t		uid;
95 	gid_t		gid;
96 	uid_t		cuid;
97 	gid_t		cgid;
98 	mode_t		mode;
99 	unsigned long	seq;
100 	void		*security;
101 };
102 
103 struct ipc_ids;
104 struct ipc_namespace {
105 	struct kref	kref;
106 	struct ipc_ids	*ids[3];
107 
108 	int		sem_ctls[4];
109 	int		used_sems;
110 
111 	int		msg_ctlmax;
112 	int		msg_ctlmnb;
113 	int		msg_ctlmni;
114 	atomic_t	msg_bytes;
115 	atomic_t	msg_hdrs;
116 
117 	size_t		shm_ctlmax;
118 	size_t		shm_ctlall;
119 	int		shm_ctlmni;
120 	int		shm_tot;
121 };
122 
123 extern struct ipc_namespace init_ipc_ns;
124 
125 #ifdef CONFIG_SYSVIPC
126 #define INIT_IPC_NS(ns)		.ns		= &init_ipc_ns,
127 extern void free_ipc_ns(struct kref *kref);
128 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
129 						struct ipc_namespace *ns);
130 #else
131 #define INIT_IPC_NS(ns)
132 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
133 						struct ipc_namespace *ns)
134 {
135 	return ns;
136 }
137 #endif
138 
139 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
140 {
141 #ifdef CONFIG_SYSVIPC
142 	if (ns)
143 		kref_get(&ns->kref);
144 #endif
145 	return ns;
146 }
147 
148 static inline void put_ipc_ns(struct ipc_namespace *ns)
149 {
150 #ifdef CONFIG_SYSVIPC
151 	kref_put(&ns->kref, free_ipc_ns);
152 #endif
153 }
154 
155 #endif /* __KERNEL__ */
156 
157 #endif /* _LINUX_IPC_H */
158