include/linux/ipc.h

   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 #else
  96 #define INIT_IPC_NS(ns)
  97 #endif
  98
  99 #ifdef CONFIG_IPC_NS
 100 extern void free_ipc_ns(struct kref *kref);
 101 extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
 102 extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
 103 #else
 104 static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk)
 105 {
 106         return 0;
 107 }
 108 #endif
 109
 110 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 111 {
 112 #ifdef CONFIG_IPC_NS
 113         if (ns)
 114                 kref_get(&ns->kref);
 115 #endif
 116         return ns;
 117 }
 118
 119 static inline void put_ipc_ns(struct ipc_namespace *ns)
 120 {
 121 #ifdef CONFIG_IPC_NS
 122         kref_put(&ns->kref, free_ipc_ns);
 123 #endif
 124 }
 125
 126 #endif /* __KERNEL__ */
 127
 128 #endif /* _LINUX_IPC_H */
 129
 130