patch-2.3.27 linux/ipc/util.h

• Lines: 84
• Date: Tue Nov 9 10:02:36 1999
• Orig file: v2.3.26/linux/ipc/util.h
• Orig date: Sun Nov 7 16:37:34 1999

diff -u --recursive --new-file v2.3.26/linux/ipc/util.h linux/ipc/util.h
@@ -1,12 +1,78 @@
 /*
  * linux/ipc/util.h
  * Copyright (C) 1999 Christoph Rohland
+ *
+ * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
  */
 
-/*
- * IPCMNI is the absolute maximum for ipc identifier. This is used to
- * detect stale identifiers
+#define USHRT_MAX 0xffff
+#define SEQ_MULTIPLIER	(IPCMNI)
+
+void sem_init (void);
+void msg_init (void);
+void shm_init (void);
+
+struct ipc_ids {
+	int size;
+	int in_use;
+	int max_id;
+	unsigned short seq;
+	unsigned short seq_max;
+	struct semaphore sem;	
+	spinlock_t ary;
+	struct ipc_id* entries;
+};
+
+struct ipc_id {
+	struct ipc_perm* p;
+};
+
+
+void __init ipc_init_ids(struct ipc_ids* ids, int size);
+
+/* must be called with ids->sem acquired.*/
+int ipc_findkey(struct ipc_ids* ids, key_t key);
+int ipc_addid(struct ipc_ids* ids, struct ipc_perm* new, int size);
+
+/* must be called with both locks acquired. */
+struct ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
+
+int ipcperms (struct ipc_perm *ipcp, short flg);
+
+/* for rare, potentially huge allocations.
+ * both function can sleep
  */
-#define IPCMNI (1<<15)          
+void* ipc_alloc(int size);
+void ipc_free(void* ptr, int size);
+
+extern inline struct ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
+{
+	struct ipc_perm* out;
+	int lid = id % SEQ_MULTIPLIER;
+	if(lid > ids->size)
+		return NULL;
+
+	spin_lock(&ids->ary);
+	out = ids->entries[lid].p;
+	if(out==NULL)
+		spin_unlock(&ids->ary);
+	return out;
+}
+
+extern inline void ipc_unlock(struct ipc_ids* ids, int id)
+{
+	spin_unlock(&ids->ary);
+}
+
+extern inline int ipc_buildid(struct ipc_ids* ids, int id, int seq)
+{
+	return SEQ_MULTIPLIER*seq + id;
+}
+
+extern inline int ipc_checkid(struct ipc_ids* ids, struct ipc_perm* ipcp, int uid)
+{
+	if(uid/SEQ_MULTIPLIER != ipcp->seq)
+		return 1;
+	return 0;
+}
 
-extern int ipcperms (struct ipc_perm *ipcp, short shmflg);