1 files changed, 280 insertions, 0 deletions
diff --git a/ipc/util.h b/ipc/util.h
new file mode 100644
index 000000000..0a159f69b
--- /dev/null
+++ b/ipc/util.h
@@ -0,0 +1,280 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/ipc/util.h
+ * Copyright (C) 1999 Christoph Rohland
+ *
+ * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ * namespaces support.      2006 OpenVZ, SWsoft Inc.
+ *                               Pavel Emelianov <xemul@openvz.org>
+ */
+
+#ifndef _IPC_UTIL_H
+#define _IPC_UTIL_H
+
+#include <linux/unistd.h>
+#include <linux/err.h>
+#include <linux/ipc_namespace.h>
+
+#define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
+#define SEQ_MULTIPLIER	(IPCMNI)
+
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
+
+struct ipc_namespace;
+struct pid_namespace;
+
+#ifdef CONFIG_POSIX_MQUEUE
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
+#else
+static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
+static inline void mq_put_mnt(struct ipc_namespace *ns) { }
+#endif
+
+#ifdef CONFIG_SYSVIPC
+void sem_init_ns(struct ipc_namespace *ns);
+void msg_init_ns(struct ipc_namespace *ns);
+void shm_init_ns(struct ipc_namespace *ns);
+
+void sem_exit_ns(struct ipc_namespace *ns);
+void msg_exit_ns(struct ipc_namespace *ns);
+void shm_exit_ns(struct ipc_namespace *ns);
+#else
+static inline void sem_init_ns(struct ipc_namespace *ns) { }
+static inline void msg_init_ns(struct ipc_namespace *ns) { }
+static inline void shm_init_ns(struct ipc_namespace *ns) { }
+
+static inline void sem_exit_ns(struct ipc_namespace *ns) { }
+static inline void msg_exit_ns(struct ipc_namespace *ns) { }
+static inline void shm_exit_ns(struct ipc_namespace *ns) { }
+#endif
+
+/*
+ * Structure that holds the parameters needed by the ipc operations
+ * (see after)
+ */
+struct ipc_params {
+	key_t key;
+	int flg;
+	union {
+		size_t size;	/* for shared memories */
+		int nsems;	/* for semaphores */
+	} u;			/* holds the getnew() specific param */
+};
+
+/*
+ * Structure that holds some ipc operations. This structure is used to unify
+ * the calls to sys_msgget(), sys_semget(), sys_shmget()
+ *      . routine to call to create a new ipc object. Can be one of newque,
+ *        newary, newseg
+ *      . routine to call to check permissions for a new ipc object.
+ *        Can be one of security_msg_associate, security_sem_associate,
+ *        security_shm_associate
+ *      . routine to call for an extra check if needed
+ */
+struct ipc_ops {
+	int (*getnew)(struct ipc_namespace *, struct ipc_params *);
+	int (*associate)(struct kern_ipc_perm *, int);
+	int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);
+};
+
+struct seq_file;
+struct ipc_ids;
+
+void ipc_init_ids(struct ipc_ids *ids);
+#ifdef CONFIG_PROC_FS
+void __init ipc_init_proc_interface(const char *path, const char *header,
+		int ids, int (*show)(struct seq_file *, void *));
+struct pid_namespace *ipc_seq_pid_ns(struct seq_file *);
+#else
+#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
+#endif
+
+#define IPC_SEM_IDS	0
+#define IPC_MSG_IDS	1
+#define IPC_SHM_IDS	2
+
+#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
+
+/* must be called with ids->rwsem acquired for writing */
+int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
+
+/* must be called with both locks acquired. */
+void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
+
+/* must be called with both locks acquired. */
+void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *);
+
+/* must be called with ipcp locked */
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
+
+/**
+ * ipc_get_maxidx - get the highest assigned index
+ * @ids: ipc identifier set
+ *
+ * Called with ipc_ids.rwsem held for reading.
+ */
+static inline int ipc_get_maxidx(struct ipc_ids *ids)
+{
+	if (ids->in_use == 0)
+		return -1;
+
+	if (ids->in_use == IPCMNI)
+		return IPCMNI - 1;
+
+	return ids->max_idx;
+}
+
+/*
+ * For allocation that need to be freed by RCU.
+ * Objects are reference counted, they start with reference count 1.
+ * getref increases the refcount, the putref call that reduces the recount
+ * to 0 schedules the rcu destruction. Caller must guarantee locking.
+ *
+ * refcount is initialized by ipc_addid(), before that point call_rcu()
+ * must be used.
+ */
+bool ipc_rcu_getref(struct kern_ipc_perm *ptr);
+void ipc_rcu_putref(struct kern_ipc_perm *ptr,
+			void (*func)(struct rcu_head *head));
+
+struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
+
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
+struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,
+					     struct ipc_ids *ids, int id, int cmd,
+					     struct ipc64_perm *perm, int extra_perm);
+
+static inline void ipc_update_pid(struct pid **pos, struct pid *pid)
+{
+	struct pid *old = *pos;
+	if (old != pid) {
+		*pos = get_pid(pid);
+		put_pid(old);
+	}
+}
+
+#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+/* On IA-64, we always use the "64-bit version" of the IPC structures.  */
+# define ipc_parse_version(cmd)	IPC_64
+#else
+int ipc_parse_version(int *cmd);
+#endif
+
+extern void free_msg(struct msg_msg *msg);
+extern struct msg_msg *load_msg(const void __user *src, size_t len);
+extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
+extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
+
+static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id)
+{
+	return ipcid_to_seqx(id) != ipcp->seq;
+}
+
+static inline void ipc_lock_object(struct kern_ipc_perm *perm)
+{
+	spin_lock(&perm->lock);
+}
+
+static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
+{
+	spin_unlock(&perm->lock);
+}
+
+static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm)
+{
+	assert_spin_locked(&perm->lock);
+}
+
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+	ipc_unlock_object(perm);
+	rcu_read_unlock();
+}
+
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+	return !perm->deleted;
+}
+
+struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
+int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+			const struct ipc_ops *ops, struct ipc_params *params);
+void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+		void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+struct compat_ipc_perm {
+	key_t key;
+	__compat_uid_t uid;
+	__compat_gid_t gid;
+	__compat_uid_t cuid;
+	__compat_gid_t cgid;
+	compat_mode_t mode;
+	unsigned short seq;
+};
+
+void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *);
+void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *);
+int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *);
+int get_compat_ipc64_perm(struct ipc64_perm *,
+			  struct compat_ipc64_perm __user *);
+
+static inline int compat_ipc_parse_version(int *cmd)
+{
+#ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+	int version = *cmd & IPC_64;
+	*cmd &= ~IPC_64;
+	return version;
+#else
+	return IPC_64;
+#endif
+}
+#endif
+
+/* for __ARCH_WANT_SYS_IPC */
+long ksys_semtimedop(int semid, struct sembuf __user *tsops,
+		     unsigned int nsops,
+		     const struct __kernel_timespec __user *timeout);
+long ksys_semget(key_t key, int nsems, int semflg);
+long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
+long ksys_msgget(key_t key, int msgflg);
+long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
+long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+		 long msgtyp, int msgflg);
+long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+		 int msgflg);
+long ksys_shmget(key_t key, size_t size, int shmflg);
+long ksys_shmdt(char __user *shmaddr);
+long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
+
+/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
+long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
+			    unsigned int nsops,
+			    const struct compat_timespec __user *timeout);
+#ifdef CONFIG_COMPAT
+long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
+long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
+long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
+			compat_long_t msgtyp, int msgflg);
+long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
+		       compat_ssize_t msgsz, int msgflg);
+long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
+#endif /* CONFIG_COMPAT */
+
+#endif