ipc/util.h

   1 /*
   2  * linux/ipc/util.h
   3  * Copyright (C) 1999 Christoph Rohland
   4  *
   5  * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
   6  */
   7 #define USHRT_MAX 0xffff
   8 #define SEQ_MULTIPLIER  (IPCMNI)
   9
  10 void sem_init (void);
  11 void msg_init (void);
  12 void shm_init (void);
  13
  14 struct ipc_ids {
  15         int size;
  16         int in_use;
  17         int max_id;
  18         unsigned short seq;
  19         unsigned short seq_max;
  20         struct semaphore sem;
  21         struct ipc_id* entries;
  22 };
  23
  24 struct ipc_id {
  25         struct kern_ipc_perm* p;
  26 };
  27
  28 void __init ipc_init_ids(struct ipc_ids* ids, int size);
  29
  30 /* must be called with ids->sem acquired.*/
  31 int ipc_findkey(struct ipc_ids* ids, key_t key);
  32 int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
  33
  34 /* must be called with both locks acquired. */
  35 struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
  36
  37 int ipcperms (struct kern_ipc_perm *ipcp, short flg);
  38
  39 /* for rare, potentially huge allocations.
  40  * both function can sleep
  41  */
  42 void* ipc_alloc(int size);
  43 void ipc_free(void* ptr, int size);
  44 /* for allocation that need to be freed by RCU
  45  * both function can sleep
  46  */
  47 void* ipc_rcu_alloc(int size);
  48 void ipc_rcu_free(void* arg, int size);
  49
  50 struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
  51 struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
  52 void ipc_unlock(struct kern_ipc_perm* perm);
  53 int ipc_buildid(struct ipc_ids* ids, int id, int seq);
  54 int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
  55
  56 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
  57 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
  58
  59 #ifdef __ia64__
  60   /* On IA-64, we always use the "64-bit version" of the IPC structures.  */
  61 # define ipc_parse_version(cmd) IPC_64
  62 #else
  63 int ipc_parse_version (int *cmd);
  64 #endif