include/linux/ipc.h

   1 #ifndef _LINUX_IPC_H
   2 #define _LINUX_IPC_H
   3
   4 #include <linux/types.h>
   5 #include <linux/kref.h>
   6
   7 #define IPC_PRIVATE ((__kernel_key_t) 0)
   8
   9 /* Obsolete, used only for backwards compatibility and libc5 compiles */
  10 struct ipc_perm
  11 {
  12         __kernel_key_t  key;
  13         __kernel_uid_t  uid;
  14         __kernel_gid_t  gid;
  15         __kernel_uid_t  cuid;
  16         __kernel_gid_t  cgid;
  17         __kernel_mode_t mode;
  18         unsigned short  seq;
  19 };
  20
  21 /* Include the definition of ipc64_perm */
  22 #include <asm/ipcbuf.h>
  23
  24 /* resource get request flags */
  25 #define IPC_CREAT  00001000   /* create if key is nonexistent */
  26 #define IPC_EXCL   00002000   /* fail if key exists */
  27 #define IPC_NOWAIT 00004000   /* return error on wait */
  28
  29 /* these fields are used by the DIPC package so the kernel as standard
  30    should avoid using them if possible */
  31
  32 #define IPC_DIPC 00010000  /* make it distributed */
  33 #define IPC_OWN  00020000  /* this machine is the DIPC owner */
  34
  35 /*
  36  * Control commands used with semctl, msgctl and shmctl
  37  * see also specific commands in sem.h, msg.h and shm.h
  38  */
  39 #define IPC_RMID 0     /* remove resource */
  40 #define IPC_SET  1     /* set ipc_perm options */
  41 #define IPC_STAT 2     /* get ipc_perm options */
  42 #define IPC_INFO 3     /* see ipcs */
  43
  44 /*
  45  * Version flags for semctl, msgctl, and shmctl commands
  46  * These are passed as bitflags or-ed with the actual command
  47  */
  48 #define IPC_OLD 0       /* Old version (no 32-bit UID support on many
  49                            architectures) */
  50 #define IPC_64  0x0100  /* New version (support 32-bit UIDs, bigger
  51                            message sizes, etc. */
  52
  53 #ifdef __KERNEL__
  54
  55 #define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
  56
  57 /* used by in-kernel data structures */
  58 struct kern_ipc_perm
  59 {
  60         spinlock_t      lock;
  61         int             deleted;
  62         key_t           key;
  63         uid_t           uid;
  64         gid_t           gid;
  65         uid_t           cuid;
  66         gid_t           cgid;
  67         mode_t          mode;
  68         unsigned long   seq;
  69         void            *security;
  70 };
  71
  72 struct ipc_ids;
  73 struct ipc_namespace {
  74         struct kref     kref;
  75         struct ipc_ids  *ids[3];
  76
  77         int             sem_ctls[4];
  78         int             used_sems;
  79
  80         int             msg_ctlmax;
  81         int             msg_ctlmnb;
  82         int             msg_ctlmni;
  83
  84         size_t          shm_ctlmax;
  85         size_t          shm_ctlall;
  86         int             shm_ctlmni;
  87         int             shm_tot;
  88 };
  89
  90 extern struct ipc_namespace init_ipc_ns;
  91
  92 #ifdef CONFIG_SYSVIPC
  93 #define INIT_IPC_NS(ns)         .ns             = &init_ipc_ns,
  94 #else
  95 #define INIT_IPC_NS(ns)
  96 #endif
  97
  98 #ifdef CONFIG_IPC_NS
  99 extern void free_ipc_ns(struct kref *kref);
 100 extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
 101 extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
 102 #else
 103 static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk)
 104 {
 105         return 0;
 106 }
 107 #endif
 108
 109 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 110 {
 111 #ifdef CONFIG_IPC_NS
 112         if (ns)
 113                 kref_get(&ns->kref);
 114 #endif
 115         return ns;
 116 }
 117
 118 static inline void put_ipc_ns(struct ipc_namespace *ns)
 119 {
 120 #ifdef CONFIG_IPC_NS
 121         kref_put(&ns->kref, free_ipc_ns);
 122 #endif
 123 }
 124
 125 #endif /* __KERNEL__ */
 126
 127 #endif /* _LINUX_IPC_H */
 128
 129